Infective endocarditis caused by Klebsiella oxytoca in an intravenous drug user with cancer

PubMed Central

Hall, Connor; Hatch, Michael; Ayan, Mohamed; Winn, Richard

2016-01-01

Infective endocarditis caused by Klebsiella species is rare, with most isolates being K. pneumoniae. We report the case of a 24-year-old intravenous drug user with newly diagnosed seminoma who developed K. oxytoca endocarditis. In addition to having K. oxytoca isolated from blood culture, cultures of that species were obtained from a retroperitoneal metastasis found on original presentation. PMID:27034562

Characterization and genome analysis of novel bacteriophages infecting the opportunistic human pathogens Klebsiella oxytoca and K. pneumoniae.

PubMed

Park, Eun-Ah; Kim, You-Tae; Cho, Jae-Hyun; Ryu, Sangryeol; Lee, Ju-Hoon

2017-04-01

Klebsiella is a genus of well-known opportunistic human pathogens that are associated with diabetes mellitus and chronic pulmonary obstruction; however, this pathogen is often resistant to multiple drugs. To control this pathogen, two Klebsiella-infecting phages, K. oxytoca phage PKO111 and K. pneumoniae phage PKP126, were isolated from a sewage sample. Analysis of their host range revealed that they infect K. pneumoniae and K. oxytoca, suggesting host specificity for members of the genus Klebsiella. Stability tests confirmed that the phages are stable under various temperature (4 to 60 °C) and pH (3 to 11) conditions. A challenge assay showed that PKO111 and PKP126 inhibit growth of their host strains by 2 log and 4 log, respectively. Complete genome sequencing of the phages revealed that their genome sizes are quite different (168,758 bp for PKO111 and 50,934 bp for PKP126). Their genome annotation results showed that they have no human virulence-related genes, an important safety consideration. In addition, no lysogen-formation gene cluster was detected in either phage genome, suggesting that they are both virulent phages in their bacterial hosts. Based on these results, PKO111 and PKP126 may be good candidates for development of biocontrol agents against members of the genus Klebsiella for therapeutic purposes. A comparative analysis of tail-associated gene clusters of PKO111 and PKP126 revealed relatively low homology, suggesting that they might differ in the way they recognize and infect their specific hosts.

The study of Nickel Resistant Bacteria (NiRB) isolated from wastewaters polluted with different industrial sources

PubMed Central

2014-01-01

Background Pollution due to the heavy metals is a problem that may have negative consequences on the hydrosphere. One of the best procedures in removing the toxic metals from the environment is using metal resistant bacteria. Results In the present study eight nickel resistant bacteria were isolated from industrial wastewaters. Three of them were selected as the most resistant based on their Maximum tolerable concentration (8, 16 and 24 mM Ni2+). Their identification was done according to morphological, biochemical characteristics and 16SrDNA gene sequencing and they were identified as Cupriavidus sp ATHA3, Klebsiella oxytoca ATHA6 and Methylobacterium sp ATHA7. The accession numbers assigned to ATHA3, ATHA6 and ATHA7 strains are JX120152, JX196648 and JX457333 respectively. The Growth rate of the most resistant isolate, Klebsiella oxytoca strain ATHA6, in the presence of Ni2+ and the reduction in Ni2+ concentration was revealed that K oxytoca ATHA6 could decrease 83 mg/mL of nickel from the medium after 3 days. Conclusion It can be concluded that the identified Ni resistant bacteria could be valuable for the bioremediation of Ni polluted waste water and sewage. PMID:24475932

The Periplasmic Cyclodextrin Binding Protein CymE from Klebsiella oxytoca and Its Role in Maltodextrin and Cyclodextrin Transport

PubMed Central

Pajatsch, Markus; Gerhart, Maria; Peist, Ralf; Horlacher, Reinhold; Boos, Winfried; Böck, August

1998-01-01

Klebsiella oxytoca M5a1 has the capacity to transport and to metabolize α-, β- and γ-cyclodextrins. Cyclodextrin transport is mediated by the products of the cymE, cymF, cymG, cymD, and cymA genes, which are functionally homologous to the malE, malF, malG, malK, and lamB gene products of Escherichia coli. CymE, which is the periplasmic binding protein, has been overproduced and purified. By substrate-induced fluorescence quenching, the binding of ligands was analyzed. CymE bound α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin, with dissociation constants (Kd) of 0.02, 0.14 and 0.30 μM, respectively, and linear maltoheptaose, with a Kd of 70 μM. In transport experiments, α-cyclodextrin was taken up by the cym system of K. oxytoca three to five times less efficiently than maltohexaose by the E. coli maltose system. Besides α-cyclodextrin, maltohexaose was also taken up by the K. oxytoca cym system, but because of the inability of maltodextrins to induce the cym system, growth of E. coli mal mutants on linear maltodextrin was not observed when the cells harbored only the cym uptake system. Strains which gained this capacity by mutation could easily be selected, however. PMID:9573146

Comparative in vitro activities of ciprofloxacin, clinafloxacin, gatifloxacin, levofloxacin, moxifloxacin, and trovafloxacin against Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, and Enterobacter aerogenes clinical isolates with alterations in GyrA and ParC proteins.

PubMed

Brisse, S; Milatovic, D; Fluit, A C; Verhoef, J; Martin, N; Scheuring, S; Köhrer, K; Schmitz, F J

1999-08-01

The in vitro activities of ciprofloxacin, clinafloxacin, gatifloxacin, levofloxacin, moxifloxacin, and trovafloxacin were tested against 72 ciprofloxacin-resistant and 28 ciprofloxacin-susceptible isolates of Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, and Enterobacter aerogenes. Irrespective of the alterations in GyrA and ParC proteins, clinafloxacin exhibited greater activity than all other fluoroquinolones tested against K. pneumoniae and E. aerogenes.

Comparative In Vitro Activities of Ciprofloxacin, Clinafloxacin, Gatifloxacin, Levofloxacin, Moxifloxacin, and Trovafloxacin against Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, and Enterobacter aerogenes Clinical Isolates with Alterations in GyrA and ParC Proteins

PubMed Central

Brisse, Sylvain; Milatovic, Dana; Fluit, Ad C.; Verhoef, Jan; Martin, Nele; Scheuring, Sybille; Köhrer, Karl; Schmitz, Franz-Josef

1999-01-01

The in vitro activities of ciprofloxacin, clinafloxacin, gatifloxacin, levofloxacin, moxifloxacin, and trovafloxacin were tested against 72 ciprofloxacin-resistant and 28 ciprofloxacin-susceptible isolates of Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, and Enterobacter aerogenes. Irrespective of the alterations in GyrA and ParC proteins, clinafloxacin exhibited greater activity than all other fluoroquinolones tested against K. pneumoniae and E. aerogenes. PMID:10428935

Enhanced reduction of Fe(III) oxides and methyl orange by Klebsiella oxytoca in presence of anthraquinone-2-disulfonate.

PubMed

Yu, Lei; Wang, Shi; Tang, Qing-Wen; Cao, Ming-Yue; Li, Jia; Yuan, Kun; Wang, Ping; Li, Wen-Wei

2016-05-01

Klebsiella oxytoca GS-4-08 is capable of azo dye reduction, but its quinone respiration and Fe(III) reduction abilities have not been reported so far. In this study, the abilities of this strain were reported in detail for the first time. As the biotic reduction of Fe(III) plays an important role in the biogeochemical cycles, two amorphous Fe(III) oxides were tested as the sole electron acceptor during the anaerobic respiration of strain GS-4-08. For the reduction of goethite and hematite, the biogenic Fe(II) concentrations reached 0.06 and 0.15 mM, respectively. Humic acid analog anthraquinone-2-disulfonate (AQS) was found to serve as an electron shuttle to increase the reduction of both methyl orange (MO) and amorphous Fe(III) oxides, and improve the dye tolerance of the strain. However, the formation of Fe(II) was not accelerated by biologically reduced AQS (B-AH2QS) because of the high bioavailability of soluble Fe(III). For the K. oxytoca strain, high soluble Fe(III) concentrations (above 1 mM) limit its growth and decolorization ability, while lower soluble Fe(III) concentrations produce an electron competition with MO initially, and then stimulate the decolorization after the electron couples of Fe(III)/Fe(II) are formed. With the ability to respire both soluble Fe(III) and insoluble Fe(III) oxides, this formerly known azo-reducer may be used as a promising model organism for the study of the interaction of these potentially competing processes in contaminated environments.

Isolation and characterization of Klebsiella oxytoca strain degrading crude oil from a Tunisian off-shore oil field.

PubMed

Chamkha, Mohamed; Trabelsi, Yosra; Mnif, Sami; Sayadi, Sami

2011-12-01

A facultatively anaerobic, Gram-negative, mesophilic, moderately halotolerant, non-motile, and non-sporulated bacterium, designated strain BSC5 was isolated from an off-shore "Sercina" oil field, located near the Kerkennah island, Tunisia. Yeast extract was not required for growth. Phenotypic characteristics and phylogenetic analysis of the 16S rRNA gene sequence of strain BSC5 revealed that it was related to members of the genus Klebsiella, being most closely related to the type strain of K. oxytoca (99% sequence similarity). Strain BSC5 was capable of using aerobically the crude oil as substrate growth. The growth of strain BSC5 on crude oil was followed by measuring the OD(600 nm) and by enumeration of viable cells at different culture's time. GC-MS analysis showed that strain BSC5 was capable of degrading a wide range of aliphatic hydrocarbons from C(13) to C(30) . The biodegradation rate for n -alkanes reached 44% and 75%, after 20 and 45 days of incubation, respectively. Addition of the synthetic surfactant, Tween 80, accelerated the crude oil degradation. The biodegradation rate for n -alkanes reached 61% and 98%, after 20 and 45 days of incubation, respectively. Moreover, three aromatic compounds, p -hydroxybenzoate, protocatechuate and gentisate, were metabolized completely by strain BSC5 after 24 h, under aerobic conditions. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterisation of biosynthesised silver nanoparticles by scanning electrochemical microscopy (SECM) and voltammetry.

PubMed

Battistel, Dario; Baldi, Franco; Gallo, Michele; Faleri, Claudia; Daniele, Salvatore

2015-01-01

Silver nanoparticles (AgNPs) were biosynthesised by a Klebsiella oxytoca strain BAS-10, which, during its growth, is known to produce a branched exopolysaccharide (EPS). Klebsiella oxytoca cultures, treated with AgNO3 and grown under either aerobic or anaerobic conditions, produced silver nanoparticles embedded in EPS (AgNPs-EPS) containing different amounts of Ag(0) and Ag(I) forms. The average size of the AgNPs-EPS was determined by transmission electron microscopy, while the relative abundance of Ag(0)- or Ag(I)-containing AgNPs-EPS was established by scanning electrochemical microscopy (SECM). Moreover, the release of silver(I) species from the various types of AgNPs-EPS was investigated by combining SECM with anodic stripping voltammetry. These measurements allowed obtaining information on the kinetic of silver ions release from AgNPs-EPS and their concentration profiles at the substrate/water interface. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of the MicroScan ESBL plus confirmation panel for detection of extended-spectrum beta-lactamases in clinical isolates of oxyimino-cephalosporin-resistant Gram-negative bacteria.

PubMed

Stürenburg, Enno; Lang, Melanie; Horstkotte, Matthias A; Laufs, Rainer; Mack, Dietrich

2004-11-01

We aimed to assess the performance of the MicroScan ESBL plus confirmation panel using a series of 87 oxyimino-cephalosporin-resistant Gram-negative bacilli of various species. Organisms tested included 57 extended-spectrum beta-lactamase (ESBL) strains comprising Enterobacter aerogenes (3), Enterobacter cloacae (10), Escherichia coli (11), Klebsiella pneumoniae (26), Klebsiella oxytoca (3) and Proteus mirabilis (4). Also included were 30 strains resistant to oxyimino cephalosporins but lacking ESBLs, which were characterized with other resistance mechanisms, such as inherent clavulanate susceptibility in Acinetobacter spp. (4), hyperproduction of AmpC enzyme in Citrobacter freundii (2), E. aerogenes (3), E. cloacae (3), E. coli (4), Hafnia alvei (1) and Morganella morganii (1), production of plasmid-mediated AmpC beta-lactamase in K. pneumoniae (3) and E. coli (3) or hyperproduction of K1 enzyme in K. oxytoca (6). The MicroScan MIC-based clavulanate synergy correctly classified 50 of 57 ESBL strains as ESBL-positive and 23 of 30 non-ESBL strains as ESBL-negative (yielding a sensitivity of 88% and a specificity of 76.7%, respectively). False negatives among ESBL producers were highest with Enterobacter spp. due to masking interactions between ESBL and AmpC beta-lactamases. False-positive classifications occurred in two Acinetobacter spp., one E. coli producing plasmid-mediated AmpC beta-lactamase and two K. oxytoca hyperproducing their chromosomal K1 beta-lactamase. The MicroScan clavulanate synergy test proved to be a valuable tool for ESBL confirmation. However, this test has limitations in detecting ESBLs in Enterobacter spp. and in discriminating ESBL-related resistance from the K1 enzyme and from inherent clavulanate susceptibility in Acinetobacter spp.

Antimicrobial activity of essential oils of cultivated oregano (Origanum vulgare), sage (Salvia officinalis), and thyme (Thymus vulgaris) against clinical isolates of Escherichia coli, Klebsiella oxytoca, and Klebsiella pneumoniae.

PubMed

Fournomiti, Maria; Kimbaris, Athanasios; Mantzourani, Ioanna; Plessas, Stavros; Theodoridou, Irene; Papaemmanouil, Virginia; Kapsiotis, Ioannis; Panopoulou, Maria; Stavropoulou, Elisavet; Bezirtzoglou, Eugenia E; Alexopoulos, Athanasios

2015-01-01

Oregano (Origanum vulgare), sage (Salvia officinalis), and thyme (Thymus vulgaris) are aromatic plants with ornamental, culinary, and phytotherapeutic use all over the world. In Europe, they are traditionally used in the southern countries, particularly in the Mediterranean region. The antimicrobial activities of the essential oils (EOs) derived from those plants have captured the attention of scientists as they could be used as alternatives to the increasing resistance of traditional antibiotics against pathogen infections. Therefore, significant interest in the cultivation of various aromatic and medicinal plants is recorded during the last years. However, to gain a proper and marketable chemotype various factors during the cultivation should be considered as the geographical morphology, climatic, and farming conditions. In this frame, we have studied the antimicrobial efficiency of the EOs from oregano, sage, and thyme cultivated under different conditions in a region of NE Greece in comparison to the data available in literature. Plants were purchased from a certified supplier, planted, and cultivated in an experimental field under different conditions and harvested after 9 months. EOs were extracted by using a Clevenger apparatus and tested for their antibacterial properties (Minimum inhibitory concentration - MIC) against clinical isolates of multidrug resistant Escherichia coli (n=27), Klebsiella oxytoca (n=7), and Klebsiella pneumoniae (n=16) strains by using the broth microdilution assay. Our results showed that the most sensitive organism was K. oxytoca with a mean value of MIC of 0.9 µg/mL for oregano EOs and 8.1 µg/mL for thyme. The second most sensitive strain was K. pneumoniae with mean MIC values of 9.5 µg/mL for thyme and 73.5 µg/mL for oregano EOs. E. coli strains were among the most resistant to EOs antimicrobial action as the observed MICs were 24.8-28.6 µg/mL for thyme and above 125 µg/mL for thyme and sage. Most efficient were the EOs from thyme followed by those of oregano. With MIC values above 150 µg/mL, sage EOs did not show any antibacterial efficiency against the majority of the strains. However, no significant differences were observed concerning the antimicrobial action of all EOs originating from irrigated versus non-irrigated cultivated aromatic plants.

Antimicrobial activity of essential oils of cultivated oregano (Origanum vulgare), sage (Salvia officinalis), and thyme (Thymus vulgaris) against clinical isolates of Escherichia coli, Klebsiella oxytoca, and Klebsiella pneumoniae

PubMed Central

Fournomiti, Maria; Kimbaris, Athanasios; Mantzourani, Ioanna; Plessas, Stavros; Theodoridou, Irene; Papaemmanouil, Virginia; Kapsiotis, Ioannis; Panopoulou, Maria; Stavropoulou, Elisavet; Bezirtzoglou, Eugenia E.; Alexopoulos, Athanasios

2015-01-01

Background Oregano (Origanum vulgare), sage (Salvia officinalis), and thyme (Thymus vulgaris) are aromatic plants with ornamental, culinary, and phytotherapeutic use all over the world. In Europe, they are traditionally used in the southern countries, particularly in the Mediterranean region. The antimicrobial activities of the essential oils (EOs) derived from those plants have captured the attention of scientists as they could be used as alternatives to the increasing resistance of traditional antibiotics against pathogen infections. Therefore, significant interest in the cultivation of various aromatic and medicinal plants is recorded during the last years. However, to gain a proper and marketable chemotype various factors during the cultivation should be considered as the geographical morphology, climatic, and farming conditions. In this frame, we have studied the antimicrobial efficiency of the EOs from oregano, sage, and thyme cultivated under different conditions in a region of NE Greece in comparison to the data available in literature. Methods Plants were purchased from a certified supplier, planted, and cultivated in an experimental field under different conditions and harvested after 9 months. EOs were extracted by using a Clevenger apparatus and tested for their antibacterial properties (Minimum inhibitory concentration – MIC) against clinical isolates of multidrug resistant Escherichia coli (n=27), Klebsiella oxytoca (n=7), and Klebsiella pneumoniae (n=16) strains by using the broth microdilution assay. Results Our results showed that the most sensitive organism was K. oxytoca with a mean value of MIC of 0.9 µg/mL for oregano EOs and 8.1 µg/mL for thyme. The second most sensitive strain was K. pneumoniae with mean MIC values of 9.5 µg/mL for thyme and 73.5 µg/mL for oregano EOs. E. coli strains were among the most resistant to EOs antimicrobial action as the observed MICs were 24.8–28.6 µg/mL for thyme and above 125 µg/mL for thyme and sage. Most efficient were the EOs from thyme followed by those of oregano. Conclusions With MIC values above 150 µg/mL, sage EOs did not show any antibacterial efficiency against the majority of the strains. However, no significant differences were observed concerning the antimicrobial action of all EOs originating from irrigated versus non-irrigated cultivated aromatic plants. PMID:25881620

Carbapenem-Resistant Strain of Klebsiella oxytoca Harboring Carbapenem-Hydrolyzing β-Lactamase KPC-2

PubMed Central

Yigit, Hesna; Queenan, Anne Marie; Rasheed, J. Kamile; Biddle, James W.; Domenech-Sanchez, Antonio; Alberti, Sebastian; Bush, Karen; Tenover, Fred C.

2003-01-01

We investigated a Klebsiella oxytoca isolate demonstrating resistance to imipenem, meropenem, extended-spectrum cephalosporins, and aztreonam. The MICs of both imipenem and meropenem were 32 μg/ml. The β-lactamase activity against imipenem and meropenem was inhibited in the presence of clavulanic acid. Isoelectric focusing studies demonstrated five β-lactamases with pIs of 8.2 (SHV-46), 6.7 (KPC-2), 6.5 (unknown), 6.4 (probable OXY-2), and 5.4 (TEM-1). The presence of the blaSHV and blaTEM genes was confirmed by specific PCR assays and DNA sequence analysis. Transformation and conjugation studies with Escherichia coli showed that the β-lactamase with a pI of 6.7, Klebsiella pneumoniae carbapenemase-2 (KPC-2), was encoded on an approximately 70-kb conjugative plasmid that also carried SHV-46, TEM-1, and the β-lactamase with a pI of 6.5. The blaKPC-2 determinant was cloned in E. coli and conferred resistance to imipenem, meropenem, extended-spectrum cephalosporins, and aztreonam. The amino acid sequence of KPC-2 showed a single amino acid difference, S174G, when compared with KPC-1, another carbapenem-hydrolyzing β-lactamase from K. pneumoniae 1534. Hydrolysis studies showed that purified KPC-2 hydrolyzed not only carbapenems but also penicillins, cephalosporins, and aztreonam. KPC-2 had the highest affinity for meropenem. The kinetic studies revealed that KPC-2 was inhibited by clavulanic acid and tazobactam. An examination of the outer membrane proteins of the parent K. oxytoca strain demonstrated that it expressed detectable levels of OmpK36 (the homolog of OmpC) and a higher-molecular-weight OmpK35 (the homolog of OmpF). Thus, carbapenem resistance in K. oxytoca 3127 is due to production of the Bush group 2f, class A, carbapenem-hydrolyzing β-lactamase KPC-2. This β-lactamase is likely located on a transposon that is part of a conjugative plasmid and thus has a very high potential for dissemination. PMID:14638498

The antigens contributing to the serological cross-reactions of Proteus antisera with Klebsiella representatives.

PubMed

Palusiak, Agata

2015-03-01

Proteus sp. and Klebsiella sp. mainly cause infections of the urinary and respiratory tracts or wounds in humans. The representatives of both genera produce virulence factors like lipopolysaccharide (LPS) or outer membrane proteins (OMPs) having much in common in the structures and/or functions. To check how far this similarity is revealed in the serological cross-reactivity, the bacterial masses of 24 tested Klebsiella sp. strains were tested in ELISA with polyclonal rabbit antisera specific to the representatives of 79 Proteus O serogroups. The strongest reacting systems were selected to Western blot, where the majority of Klebsiella masses reacted in a way characteristic for electrophoretic patterns of proteins. The strongest reactions were obtained for proteins of near 67 and 40 kDa and 12.5 kDa. Mass spectrometry analysis of the proteins samples of one Proteus sp. and one Klebsiella sp. strain showed the GroEL like protein of a sequence GI number 2980926 to be similar for both strains. In Western blot some Klebsiella sp. masses reacted similarly to the homologous Proteus LPSs. The LPS contribution in the observed reactions of the high molecular-mass LPS species was confirmed for Klebsiella oxytoca 0.062. Copyright © 2014 Elsevier Ltd. All rights reserved.

Production of 2,3-butanediol by a low-acid producing Klebsiella oxytoca NBRF4.

PubMed

Han, Sung-Hyuk; Lee, Jung-Eun; Park, Kyungmoon; Park, Yong-Cheol

2013-01-25

2,3-Butanediol (2,3-BDO) is a value-added chemical with great potential for the industrial production of synthetic rubber, plastic and solvent. For microbial production of 2,3-BDO, in this study, Klebsiella oxytoca NBRF4 was constructed by chemical mutation and screening against NaBr, NaBrO(3) and fluoroacetate. Among metabolic enzymes involved in the production of lactate, acetate and 2,3-BDO, K. oxytoca NBRF4 possessed 1.2 times lower specific activities of lactate dehydrogenase and phosphotransacetylase, and 22% higher specific acetoin reductase activity than the K. oxytoca ATCC43863 control strain. A series of batch fermentations in a defined medium and application of a statistical tool of response surface method led to the determination of optimal culture conditions: 10% dissolved oxygen level, pH 4.3 and 38°C. The actual results of batch fermentation at the optimal conditions using 44 g/L glucose were coincident with the predetermined values: 14.4 g/L 2,3-BDO concentration, 0.32 g/g yield. To increase 2,3-BDO titer, fed-batch fermentation of K. oxytoca NBRF4 was performed by an intermittent feeding of 800 g/L glucose to control its concentration around 5-20 g/L in the culture broth. Finally, 34.2g/L 2,3-BDO concentration and 0.35 g/g yield were obtained without organic acid production in 70 hours of the fed-batch culture, which were 2.4 and 1.2 times higher than those of the batch fermentation using 44 g/L glucose. Copyright © 2012 Elsevier B.V. All rights reserved.

Draft Genome Sequences of Klebsiella oxytoca Isolates Originating from a Highly Contaminated Liquid Hand Soap Product.

PubMed

Hammerl, J A; Lasch, P; Nitsche, A; Dabrowski, P W; Hahmann, H; Wicke, A; Kleta, S; Al Dahouk, S; Dieckmann, R

2015-07-23

In 2013, contaminated liquid soap was detected by routine microbiological monitoring of consumer products through state health authorities. Because of its high load of Klebsiella oxytoca, the liquid soap was notified via the European Union Rapid Alert System for Dangerous Non-Food Products (EU-RAPEX) and recalled. Here, we present two draft genome sequences and a summary of their general features. Copyright © 2015 Hammerl et al.

Characterization of extended-spectrum β-lactamase (ESBL)-producing Klebsiella, Enterobacter, and Citrobacter obtained in environmental samples of a Tunisian hospital.

PubMed

Dziri, Raoudha; Klibi, Naouel; Alonso, Carla Andrea; Said, Leila Ben; Bellaaj, Ridha; Slama, Karim Ben; Boudabous, Abdellatif; Torres, Carmen

2016-10-01

The assessment of the hospital environment as a reservoir of ESBL-producing Enterobacteriaceae in Tunisian hospitals is scarcely analyzed, except for Escherichia coli. The aim of this study was to evaluate the presence of ESBL-producing non-E. coli Enterobacteriaceae (ESBL-EbNoEc) in 300 samples of abiotic surfaces and the hands of patients and staff of a Tunisian Hospital, and to characterize the ESBL genes of the recovered isolates. ESBL-EbNoEc were recovered in 28 of 300 (9.3%) analyzed samples and were identified as Klebsiella pneumoniae (n= 11), Enterobacter cloacae (n=11), Citrobacter freundii (n=4) and Klebsiella oxytoca (n=2). The bla genes identified by PCR and sequencing among the strains were as follows: 11 K.pneumoniae strains [blaCTX-M-15+ blaTEM-1+ blaSHV-11 (n=6); blaCTX-M-15+ blaTEM-1+ blaSHV-28 (n=3); blaCTX-M-15+ blaTEM-1+ blaSHV-1 (n=2)], 11 E. cloacae strains [blaCTX-M-15 (n=6); blaCTX-M-15+ blaTEM-1b (n=2); blaCTX-M-15+ blaTEM-1b+ blaOXA-1 (n=1);blaCTX-M-15+ blaOXA-1 (n=1);blaSHV-12 (n=1)], 4 C. freundii strains [blaCTX-M-15] and 2 K. oxytoca strains [blaCTX-M-15 (n=1); blaSHV-12 (n=1)]. The ISEcp1 and orf477 sequences were identified upstream and downstream of the blaCTX-M-15 gene, respectively, in 3 K. pneumoniae and 3 E. cloacae isolates. The PFGE analysis demonstrated three unrelated pulsotypes in K. pneumoniae strains and five pulsotypes in E. cloacae. The uncontrolled dissemination of ESBL-producing bacteria, even in the hospital environment, has become a real problem and new strategies and hygienic rules are needed to stop this bacterial dissemination. Copyright © 2016 Elsevier Inc. All rights reserved.

The distribution of carbapenem- and colistin-resistance in Gram-negative bacteria from the Tamil Nadu region in India.

PubMed

Manohar, Prasanth; Shanthini, Thamaraiselvan; Ayyanar, Ramankannan; Bozdogan, Bulent; Wilson, Aruni; Tamhankar, Ashok J; Nachimuthu, Ramesh; Lopes, Bruno S

2017-07-01

The occurrence of carbapenem- and colistin-resistance among Gram-negative bacteria is increasing worldwide. The aim of this study was to understand the distribution of carbapenem- and colistin-resistance in two areas in Tamil Nadu, India. The clinical isolates (n=89) used in this study were collected from two diagnostic centres in Tamil Nadu, India. The bacterial isolates were screened for meropenem- and colistin-resistance. Further, resistance genes blaNDM-1, blaOXA-48-like, blaIMP, blaVIM, blaKPC, mcr-1 and mcr-2 and integrons were studied. The synergistic effect of meropenem in combination with colistin was assessed. A total of 89 bacterial isolates were studied which included Escherichia coli (n=43), Klebsiella pneumoniae (n=18), Pseudomonas aeruginosa (n=10), Enterobacter cloacae (n=6), Acinetobacter baumannii (n=5), Klebsiella oxytoca (n=4), Proteus mirabilis (n=2) and Salmonella paratyphi (n=1). MIC testing showed that 58/89 (65 %) and 29/89 (32 %) isolates were resistant to meropenem and colistin, respectively, whereas 27/89 (30 %) isolates were resistant to both antibiotics. Escherichia coli, K. pneumoniae, K. oxytoca, Pseudomonas aeruginosa, and Enterobacter cloacae isolates were blaNDM-1-positive (n=20). Some strains of Escherichia coli, K. pneumoniae and K. oxytoca were blaOXA-181-positive (n=4). Class 1, 2 and 3 integrons were found in 24, 20 and 3 isolates, respectively. Nine NDM-1-positive Escherichia coli strains could transfer carbapenem resistance via plasmids to susceptible Escherichia coli AB1157. Meropenem and colistin showed synergy in 10/20 (50 %) isolates by 24 h time-kill studies. Our results highlight the distribution of carbapenem- and colistin-resistance in Gram-negative bacteria isolated from the Tamil Nadu region in South India.

Efficient reduction of the formation of by-products and improvement of production yield of 2,3-butanediol by a combined deletion of alcohol dehydrogenase, acetate kinase-phosphotransacetylase, and lactate dehydrogenase genes in metabolically engineered Klebsiella oxytoca in mineral salts medium.

PubMed

Jantama, Kaemwich; Polyiam, Pattharasedthi; Khunnonkwao, Panwana; Chan, Sitha; Sangproo, Maytawadee; Khor, Kirin; Jantama, Sirima Suvarnakuta; Kanchanatawee, Sunthorn

2015-07-01

Klebsiella oxytoca KMS005 (∆adhE∆ackA-pta∆ldhA) was metabolically engineered to improve 2,3-butanediol (BDO) yield. Elimination of alcohol dehydrogenase E (adhE), acetate kinase A-phosphotransacetylase (ackA-pta), and lactate dehydrogenase A (ldhA) enzymes allowed BDO production as a primary pathway for NADH re-oxidation, and significantly reduced by-products. KMS005 was screened for the efficient glucose utilization by metabolic evolution. KMS005-73T improved BDO production at a concentration of 23.5±0.5 g/L with yield of 0.46±0.02 g/g in mineral salts medium containing 50 g/L glucose in a shake flask. KMS005-73T also exhibited BDO yields of about 0.40-0.42 g/g from sugarcane molasses, cassava starch, and maltodextrin. During fed-batch fermentation, KMS005-73T produced BDO at a concentration, yield, and overall and specific productivities of 117.4±4.5 g/L, 0.49±0.02 g/g, 1.20±0.05 g/Lh, and 27.2±1.1 g/gCDW, respectively. No acetoin, lactate, and formate were detected, and only trace amounts of acetate and ethanol were formed. The strain also produced the least by-products and the highest BDO yield among other Klebsiella strains previously developed. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Appendix. Cloning and sequence of the gene encoding enzyme E-1 from the methionine salvage pathway of Klebsiella oxytoca.

PubMed

Balakrishnan, R; Frohlich, M; Rahaim, P T; Backman, K; Yocum, R R

1993-11-25

The methionine salvage pathway converts the methylthioribose moiety of 5'-(methylthio)-adenosine to methionine via a series of biochemical steps. One enzyme active in this pathway, a bifunctional enolase-phosphatase called E-1 that promotes oxidative cleavage of the synthetic substrate 2,3-diketo-1-phosphohexane to 2-keto-pentanoate, has been purified from Klebsiella pneumoniae and is characterized in the preceding paper (Myers, R., Wray, J., Fish, S., and Abeles, R. H. (1993) J. Biol. Chem. 268, 24785-24791). We synthesized degenerate oligonucleotides corresponding to portions of the amino terminus of E-1. These oligonucleotides were used as polymerase chain reaction primers on whole genomic DNA from Klebsiella oxytoca. This resulted in an 82-base pair DNA fragment that was used as a hybridization probe to obtain a clone of the E-1 gene from a K. oxytoca gene library. The DNA sequence of the E-1 coding region was determined, and the amino acid sequence of E-1 was deduced. E-1 appears to represent a novel class of enzymes since no homology to known enzymes was found. Cloning the gene from K. oxytoca on a multicopy plasmid leads to overproduction of E-1 enzyme that has properties indistinguishable from those of the enzyme from K. pneumoniae.

Evaluation of the Clinical and Laboratory Standards Institute phenotypic confirmatory test to detect the presence of extended-spectrum β-lactamases from 4005 Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae and Proteus mirabilis isolates.

PubMed

Morrissey, Ian; Bouchillon, Samuel K; Hackel, Meredith; Biedenbach, Douglas J; Hawser, Stephen; Hoban, Daryl; Badal, Robert E

2014-04-01

A subset of Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae and Proteus mirabilis isolates collected for the Study for Monitoring Antimicrobial Resistance Trends that were positive for the Clinical and Laboratory Standards Institute (CLSI) extended-spectrum β-lactamase (ESBL) phenotypic confirmatory test (n = 3245) or had an ertapenem MIC of ≥0.5 µg ml(-1) (n = 293), or both (n = 467), were analysed for ESBL genes. Most ESBL phenotype E. coli or K. pneumoniae possessed an ESBL gene (95.8 and 88.4 %, respectively), and this was 93.1 % if carbapenem-non-susceptible K. pneumoniae were removed. This rate was lower for P. mirabilis (73.4 %) and K. oxytoca (62.5 %). Virtually all ESBL-positive isolates (99.5 %) were cefotaxime non-susceptible [CLSI or European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints)]. Fewer isolates (82 %) were ceftazidime non-susceptible (CLSI breakpoints). In addition, 21.1 % of E. coli, 25 % of K. oxytoca and 78.7 % of P. mirabilis isolates were ceftazidime susceptible but ESBL positive. This suggests that CLSI breakpoints for ceftazidime are too high to detect ESBLs. The lower EUCAST breakpoints detected ESBLs in E. coli and K. oxytoca better, but 59.6 % of ESBL-positive isolates of P. mirabilis were ceftazidime susceptible. For isolates with ertapenem MICs ≥0.5 µg ml(-1), more accurate ESBL phenotype analysis was observed for E. coli and K. pneumoniae (sensitivity >95 % for both, specificity 94.4 and 54.1 %, respectively). If carbapenemase-positive K. pneumoniae were excluded, the specificity increased to 78 %. The positive predictive values for the ESBL phenotypic test with E. coli and K. pneumoniae were 97.6 and 81.8 %, respectively, and negative predictive values were 75.9 and 95.2 %, respectively. We therefore suggest that it would be prudent to confirm phenotypic ESBL-positive P. mirabilis, K. pneumoniae and K. oxytoca with molecular analysis.

The genes and enzymes for the catabolism of galactitol, D-tagatose, and related carbohydrates in Klebsiella oxytoca M5a1 and other enteric bacteria display convergent evolution.

PubMed

Shakeri-Garakani, A; Brinkkötter, A; Schmid, K; Turgut, S; Lengeler, J W

2004-07-01

Enteric bacteria (Enteriobacteriaceae) carry on their single chromosome about 4000 genes that all strains have in common (referred to here as "obligatory genes"), and up to 1300 "facultative" genes that vary from strain to strain and from species to species. In closely related species, obligatory and facultative genes are orthologous genes that are found at similar loci. We have analyzed a set of facultative genes involved in the degradation of the carbohydrates galactitol, D-tagatose, D-galactosamine and N-acetyl-galactosamine in various pathogenic and non-pathogenic strains of these bacteria. The four carbohydrates are transported into the cell by phosphotransferase (PTS) uptake systems, and are metabolized by closely related or even identical catabolic enzymes via pathways that share several intermediates. In about 60% of Escherichia coli strains the genes for galactitol degradation map to a gat operon at 46.8 min. In strains of Salmonella enterica, Klebsiella pneumoniae and K. oxytoca, the corresponding gat genes, although orthologous to their E. coli counterparts, are found at 70.7 min, clustered in a regulon together with three tag genes for the degradation of D-tagatose, an isomer of D-fructose. In contrast, in all the E. coli strains tested, this chromosomal site was found to be occupied by an aga/kba gene cluster for the degradation of D-galactosamine and N-acetyl-galactosamine. The aga/kba and the tag genes were paralogous either to the gat cluster or to the fru genes for degradation of D-fructose. Finally, in more then 90% of strains of both Klebsiella species, and in about 5% of the E. coli strains, two operons were found at 46.8 min that comprise paralogous genes for catabolism of the isomers D-arabinitol (genes atl or dal) and ribitol (genes rtl or rbt). In these strains gat genes were invariably absent from this location, and they were totally absent in S. enterica. These results strongly indicate that these various gene clusters and metabolic pathways have been subject to convergent evolution among the Enterobacteriaceae. This apparently involved recent horizontal gene transfer and recombination events, as indicated by major chromosomal rearrangements found in their immediate vicinity.

Transport processes and mutual interactions of three bacterial strains in saturated porous media

NASA Astrophysics Data System (ADS)

Stumpp, Christine; Lawrence, John R.; Hendry, M. Jim; Maloszewski, Pitor

2010-05-01

Transport processes of the bacterial strains Klebsiella oxytoca, Burkholderia cepacia G4PR-1 and Pseudomonas sp #5 were investigated in saturated column experiments to study the differences in transport characteristics and the mutual interactions of these strains during transport. Soil column experiments (114 mm long x 33 mm in diameter) were conducted with constant water velocities (3.9-5.7 cm/h) through a medium to coarse grained silica sand. All experiments were performed in freshly packed columns in quadruplicate. Chloride was used as tracer to determine the mean transit time, dispersivity and flow rate. It was injected as a pulse into the columns together with the bacterial strains suspended in artificial groundwater medium. In the first setup, each strain was investigated alone. In the second setup, transport processes were performed injecting two strains simultaneously. Finally, the transport characteristics were studied in successive experiments when one bacterium was resident on the sand grains prior to the introduction of the second strain. In all experiments the peak C/Co bacterial concentrations were attenuated with respect to the conservative tracer chloride and a well defined tailing was observed. A one dimensional mathematical model for advective-dispersive transport that accounts for irreversible and reversible sorption was used to analyze the bacterial breakthrough curves and tailing patterns. It was shown that the sorption parameters were different for the three strains that can be explained by the properties of the bacteria. For the species Klebsiella oxytoca and Burkholderia cepacia G4PR-the transport parameters were mostly in the same range independent of the experimental setup. However, Pseudomonas sp #5, which is a motile bacterium, showed differences in the breakthrough curves and sorption parameters during the experiments. The simultaneous and successive experiments indicated an influence on the reversible sorption processes when another strain was present during the transport processes.

Characterization of Klebsiella pneumoniae isolates from New Zealand sea lion (Phocarctos hookeri) pups during and after the epidemics on Enderby Island, Auckland Islands.

PubMed

Castinel, Aurélie; Grinberg, Alex; Pattison, Rebecca; Duignan, Pádraig; Pomroy, Bill; Rogers, Lynn; Wilkinson, Ian

2007-05-16

The 2001/2002 and 2002/2003 breeding seasons of New Zealand sea lions (NZSLs) on the Auckland Islands were marked by a high pup mortality caused by acute bacterial infections. As part of a health survey from 1998/1999 to 2004/2005, tissues and swabs of lesions had been collected at necropsy to identify the bacteria associated with pup mortality. Klebsiella pneumoniae was grown in pure culture from 83% of various organs and lesions in 2001/2002 and 76% in 2002/2003, and less frequently in the following seasons (56% in 2003/2004 and 49% in 2004/2005). Pup isolates of K. pneumoniae showed identical minimal inhibitory concentrations (MIC) of cefuroxime, neomycin, cephalotin, cephalexin and dihydrostreptomycin, suggesting clonal aetiology of the pathogen. Isolates also tested negative for production of extended-spectrum beta-lactamases (ESBLs), which was not in favour of an anthropogenetic origin of the epidemic strain. Pulsed-field gel electrophoresis (PFGE) of XbaI DNA macrorestriction fragments was performed on isolates of K. pneumoniae and Klebsiella oxytoca from 35 pups, thee NZSL adult females, and from three human patients for comparison. PFGE showed that pup isolates of K. pneumoniae were genetically indistinguishable but were neither related to K. pneumoniae from humans and from NZSL adults, nor to K. oxytoca from NZSLs. It is concluded that the 2001/2002 and 2002/2003 epidemics at Sandy Bay rookery were caused by a single K. pneumoniae clonal lineage, genetically different from the strain carried by adult NZSLs. An anthropogenic origin of the K. pneumoniae clone could not be confirmed, but further investigations are required to rule-out such occurrence.

Process Optimization on Micro-Aeration Supply for High Production Yield of 2,3-Butanediol from Maltodextrin by Metabolically-Engineered Klebsiella oxytoca

PubMed Central

Jantama, Sirima Suvarnakuta; Kanchanatawee, Sunthorn

2016-01-01

An optimization process with a cheap and abundant substrate is considered one of the factors affecting the price of the production of economical 2,3-Butanediol (2,3-BD). A combination of the conventional method and response surface methodology (RSM) was applied in this study. The optimized levels of pH, aeration rate, agitation speed, and substrate concentration (maltodextrin) were investigated to determine the cost-effectiveness of fermentative 2,3-BD production by metabolically-engineered Klebsiella oxytoca KMS005. Results revealed that pH, aeration rate, agitation speed, and maltodextrin concentration at levels of 6.0, 0.8 vvm, 400 rpm, and 150 g/L respectively were the optimal conditions. RSM also indicated that the agitation speed was the most influential parameter when either agitation and aeration interaction or agitation and substrate concentration interaction played important roles for 2,3-BD production by the strain from maltodextrin. Under interim fed-batch fermentation, 2,3-BD concentration, yield, and productivity were obtained at 88.1±0.2 g/L, 0.412±0.001 g/g, and 1.13±0.01 g/L/h respectively within 78 h. PMID:27603922

Rapid characterisation of Klebsiella oxytoca isolates from contaminated liquid hand soap using mass spectrometry, FTIR and Raman spectroscopy.

PubMed

Dieckmann, Ralf; Hammerl, Jens Andre; Hahmann, Hartmut; Wicke, Amal; Kleta, Sylvia; Dabrowski, Piotr Wojciech; Nitsche, Andreas; Stämmler, Maren; Al Dahouk, Sascha; Lasch, Peter

2016-06-23

Microbiological monitoring of consumer products and the efficiency of early warning systems and outbreak investigations depend on the rapid identification and strain characterisation of pathogens posing risks to the health and safety of consumers. This study evaluates the potential of three rapid analytical techniques for identification and subtyping of bacterial isolates obtained from a liquid hand soap product, which has been recalled and reported through the EU RAPEX system due to its severe bacterial contamination. Ten isolates recovered from two bottles of the product were identified as Klebsiella oxytoca and subtyped using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI TOF MS), near-infrared Fourier transform (NIR FT) Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy. Comparison of the classification results obtained by these phenotype-based techniques with outcomes of the DNA-based methods pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST) and single nucleotide polymorphism (SNP) analysis of whole-genome sequencing (WGS) data revealed a high level of concordance. In conclusion, a set of analytical techniques might be useful for rapid, reliable and cost-effective microbial typing to ensure safe consumer products and allow source tracking.

Laurus nobilis, Zingiber officinale and Anethum graveolens Essential Oils: Composition, Antioxidant and Antibacterial Activities against Bacteria Isolated from Fish and Shellfish.

PubMed

Snuossi, Mejdi; Trabelsi, Najla; Ben Taleb, Sabrine; Dehmeni, Ameni; Flamini, Guido; De Feo, Vincenzo

2016-10-22

Several bacterial strains were isolated from wild and reared fish and shellfish. The identification of these strains showed the dominance of the Aeromonas hydrophila species in all seafood samples, followed by Staphylococcus spp., Vibrio alginolyticus , Enterobacter cloacae , Klebsiella ornithinolytica , Klebsiella oxytoca and Serratia odorifera . The isolates were studied for their ability to produce exoenzymes and biofilms. The chemical composition of the essential oils from Laurus nobilis leaves, Zingiber officinale rhizomes and Anethum graveolens aerial parts was studied by GC and GC/MS. The essential oils' antioxidant and antibacterial activities against the isolated microorganisms were studied. Low concentrations of the three essential oils were needed to inhibit the growth of the selected bacteria and the lowest MBCs values were obtained for the laurel essential oil. The selected essential oils can be used as a good natural preservative in fish food due to their antioxidant and antibacterial activities.

Infectious crystalline keratopathy associated with Klebsiella oxytoca.

PubMed

Chou, Timothy Y; Adyanthaya, Rohit

2012-12-01

The purpose of this study is to report a novel case of a Klebsiella oxytoca-associated infectious crystalline keratopathy This is a case report study. An 80-year-old woman presented with complaint of noticing a white spot in the left eye for 2 to 3 days, as well as mild soreness and discharge. Past ocular history was notable for a failed left corneal transplant for which she was taking prednisolone acetate 1 % twice per day. On slit-lamp examination, there was an extensive stromal ulcer and infiltrate in the inferior half of the transplant. Extending superiorly in the graft were branching, needle-like deep stromal opacities, characteristic of infectious crystalline keratopathy. Diagnostic scrapings revealed Gram-negative bacilli, subsequently identified on culture as K. oxytoca. There was also light growth of Staphylococcus species. The patient was placed on double topical antibiotic therapy with moxifloxacin and fortified tobramycin. After 2 months of treatment there was gradual resolution of the infection. K. oxytoca is a microorganism which can be associated with clinical infectious crystalline keratopathy, presenting as a mixed infection along with Staphylococcus species.

New report of additional enterobacterial species causing wilt in West Bengal, India.

PubMed

Sarkar, Shamayeeta; Chaudhuri, Sujata

2015-07-01

Ralstonia solanacearum is known to be the most prominent causal agent of bacterial wilt worldwide. It has a wide host range comprising solanaceous and nonsolanaceous plants. Typical symptoms of the disease are leaf wilt, browning of vascular tissues, and collapsing of the plant. With the objective of studying the diversity of pathogens causing bacterial wilt in West Bengal, we collected samples of diseased symptomatic crops and adjacent symptomatic and asymptomatic weeds from widespread locations in West Bengal. By means of a routine molecular identification test specific to "R. solanacearum species complex", the majority of these strains (68 out of 71) were found to not be R. solanacearum. Presumptive identification of these isolates with conventional biochemicals, extensive testing of pathogenicity of a subset involving greenhouse trials fulfilling Koch's postulate test, and scanning electron microscopic analysis for the presence of pathogen in diseased plants were done. 16S rDNA sequencing of a subset of these strains (GenBank accession Nos. JX880249-JX880251) and analysis of sequences with the nBLAST programme showed a high similarity (97%-99%) to sequences of the Enterobacteriaceae group available in GenBank. Molecular phylogeny further established the taxonomic position of the strains. The 3 bacterial strain cultures have been submitted to MTCC, Institute of Microbial Technology, Chandigarh, India, and were identified as Klebsiella oxytoca, Enterobacter cowanii, and Klebsiella oxytoca, respectively. Although Enterobacter sp. has previously been reported to cause wilt in many plants, susceptibility of most of the dedicated hosts of R. solanacearum to wilt caused by Enterobacter and other bacteria from Enterobacteriaceae is being reported for the first time in this work.

Bacteria on housefly eggs, Musca domestica, suppress fungal growth in chicken manure through nutrient depletion or antifungal metabolites

NASA Astrophysics Data System (ADS)

Lam, Kevin; Thu, Kelsie; Tsang, Michelle; Moore, Margo; Gries, Gerhard

2009-09-01

Female houseflies, Musca domestica (Diptera: Muscidae), lay their eggs in ephemeral resources such as animal manure. Hatching larvae compete for essential nutrients with fungi that also colonize such resources. Both the well-known antagonistic relationship between bacteria and fungi and the consistent presence of the bacterium Klebsiella oxytoca on housefly eggs led us to hypothesize (1) that K. oxytoca, and possibly other bacteria on housefly eggs, help curtail the growth of fungal resource competitors and (2) that such fungi indeed adversely affect the development of housefly larvae. Bacteria washed from housefly eggs significantly reduced the growth of fungi in chicken manure. Nineteen bacterial strains and ten fungal strains were isolated from housefly eggs or chicken manure, respectively. Co-culturing each of all the possible bacterium-fungus pairs revealed that the bacteria as a group, but no single bacterium, significantly suppressed the growth of all fungal strains tested. The bacteria's adverse effect on fungi is due to resource nutrient depletion and/or the release of antifungal chemicals. Well-established fungi in resources significantly reduced the number of larval offspring that completed development to adult flies.

Identification of clinical isolates of indole-positive Klebsiella spp., including Klebsiella planticola, and a genetic and molecular analysis of their beta-lactamases.

PubMed Central

Liu, Y; Mee, B J; Mulgrave, L

1997-01-01

In a collection of 43 indole-positive Klebsiella clinical isolates, which were initially identified as Klebsiella oxytoca, there were 18 isolates which exhibited a pattern characteristic of extended-spectrum beta-lactamase (ESBL) resistance. This study aimed to confirm their identity by biochemical tests and by PCR and to determine the genetic basis for their resistance to the beta-lactams and broad-spectrum cephalosporins. Chromosomal beta-lactamase genes were analyzed by PCR, and plasmid-mediated beta-lactamase genes were analyzed by conjugation and transformation. There were 39 isolates which grew on melezitose but failed to grow on 3-hydroxybutyrate, confirming them as K. oxytoca. PCR analysis of their beta-lactamase genes divided these isolates into two groups, the bla(OXY-1) group and the bla(OXY-2) group. Each group had beta-lactamases with different isoelectric points; the bla(OXY-1) group had beta-lactamases with isoelectric points at 7.2, 7.8, 8.2, and 8.8, and the more common bla(OXY-2) group had beta-lactamases with pIs at 5.2, 5.4 (TEM-1), 5.7, 5.9, 6.4, and 6.8. A pI of 5.2 was the most frequently detected and accounted for 59% of all the bla(OXY-2) beta-lactamases. Hyperproduction of clavulanate-inhibited chromosomal beta-lactamases was detected in 17 K. oxytoca isolates, resulting in an ESBL phenotype. K. oxytoca isolates having a plasmid-mediated genetic basis for their ESBL phenotype were not found, confirming that, in K. oxytoca, plasmids are rarely involved in conferring resistance to the newer cephalosporins. Four isolates proved to be isolates of K. planticola in which the beta-lactamase genes failed to react with the primers used in the PCR. One K. planticola isolate contained a transferable plasmid harboring the SHV-5 beta-lactamase gene and showed an ESBL phenotype, while the other non-ESBL K. planticola isolates contained chromosomal beta-lactamases with isoelectric points at 7.2, 7.7, and 7.9 plus 7.2. PMID:9276417

Ugly bugs in healthy guts! Carriage of multidrug-resistant and ESBL-producing commensal Enterobacteriaceae in the intestine of healthy Nepalese adults.

PubMed

Maharjan, Anjila; Bhetwal, Anjeela; Shakya, Shreena; Satyal, Deepa; Shah, Shashikala; Joshi, Govardhan; Khanal, Puspa Raj; Parajuli, Narayan Prasad

2018-01-01

Fecal carriage of multidrug-resistant and extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is one of the important risk factors for infection with antibiotic-resistant bacteria. In this report, we examined the prevalence of multidrug-resistant and ESBL-producing common enterobacterial strains colonizing the intestinal tract of apparently healthy adults in Kathmandu, Nepal. During a 6-month period (February-July 2016), a total of 510 stool specimens were obtained from apparently healthy students of Manmohan Memorial Institute of Health Sciences, Kathmandu, Nepal. Stool specimens were cultured, and the most common enterobacterial isolates ( Escherichia coli and Klebsiella species) were subjected to antimicrobial susceptibility tests according to the standard microbiologic guidelines. Multidrug-resistant isolates were selected for ESBL confirmation by combined disk test and E-test methods. Molecular characterization of plasmid-borne ESBL genes was performed by using specific primers of cefotaximase Munich (CTX-M), sulfhydryl variant (SHV), and temoniera (TEM) by polymerase chain reaction. Among 510 bacterial strains, E. coli (432, 84.71%) was the predominant organism followed by Klebsiella oxytoca (48, 9.41%) and K. pneumoniae (30, 5.88%). ESBLs were isolated in 9.8% of the total isolates including K. oxytoca (29.17%), E. coli (7.87%), and K. pneumoniae (6.67%). Among ESBLs, bla -TEM was the predominant type (92%) followed by bla -CTX-M (60%) and bla -SHV (4%). Multidrug-resistant and ESBL-producing enterobacterial commensal strains among healthy individuals are of serious concern. Persistent carriage of ESBL organisms in healthy individuals suggests the possibility of sustained ESBL carriage among the diseased and hospitalized patients. We recommend similar types of epidemiologic surveys in larger communities and in hospital settings to ascertain the extent of ESBL resistance.

Faecal coliform bacteria in Febros river (northwest Portugal): temporal variation, correlation with water parameters, and species identification.

PubMed

Cabral, João Paulo; Marques, Cristina

2006-07-01

Febros river water was sampled weekly, during 35 successive weeks, and analyzed for microbiological (total coliforms, faecal coliforms, faecal streptococci and enterococci) and chemical-physical (ammonia and temperature) parameters. All microbiological parameters were highly correlated with each other and with ammonia, suggesting that the simultaneous determination of all variables currently in use in the evaluation of the microbiological quality of waters is probably redundant, and could be simplified, and that ammonia should be tested as a sentinel parameter of the microbiological pollution load of Febros river. From the strains isolated from positive tubes of the faecal coliforms test (multiple tube fermentation technique) and retested in this assay, Escherichia coli, Klebsiella oxytoca and Klebsiella pneumoniae subsp. pneumoniae strains were positive, indicating that the faecal coliforms test is not totally specific for Escherichia coli, and can detect other bacteria. Considering that these Klebsiella spp. are not necessarily of faecal origin, it was concluded that the faecal coliforms test can overestimate true faecal pollution. From the strains isolated from positive tubes of the faecal coliforms procedure, only Escherichia coli strains were clearly positive in the beta-D-glucuronidase test. All other species were negative or very weakly positive, suggesting that the assay of the beta-D-glucuronidase activity is less prone to false positives than the faecal coliforms test in the quantification of Escherichia coli in environmental waters.

[Rapid test for detection of susceptibility to cefotaxime in Enterobacteriaceae].

PubMed

Jiménez-Guerra, Gemma; Hoyos-Mallecot, Yannik; Rodríguez-Granger, Javier; Navarro-Marí, José María; Gutiérrez-Fernández, José

In this work an "in house" rapid test based on the change in pH that is due to hydrolysis for detecting Enterobacteriaceae susceptible to cefotaxime is evaluated. The strains of Enterobacteriaceae from 1947 urine cultures were assessed using MicroScan panels and the "in house" test. This rapid test includes red phenol solution and cefotaxime. Using MicroScan panels, 499 Enterobacteriaceae isolates were evaluated, which included 27 isolates of Escherichia coli producing extended-spectrum beta-lactamases (ESBL), 16 isolates of Klebsiella pneumoniae ESBL and 1 isolate of Klebsiella oxytoca ESBL. The "in house" test offers the following values: sensitivity 98% and specificity 97%, with negative predictive value 100% and positive predictive value 78%. The "in house" test based on the change of pH is useful in our area for detecting presumptively cefotaxime-resistant Enterobacteriaceae strains. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

XAS analysis of iron and palladium bonded to a polysaccharide produced anaerobically by a strain of Klebsiella oxytoca.

PubMed

Arčon, Iztok; Paganelli, Stefano; Piccolo, Oreste; Gallo, Michele; Vogel-Mikuš, Katarina; Baldi, Franco

2015-09-01

Klebsiella oxytoca BAS-10 ferments citrate to acetic acid and CO2, and secretes a specific exopolysaccharide (EPS), which is able to bind different metallic species. These biomaterials may be used for different biotechnological purposes, including applications as innovative green biogenerated catalysts. In production of biogenerated Pd species, the Fe(III) as ferric citrate is added to anaerobic culture of K. oxytoca BAS-10, in the presence of palladium species, to increase the EPS secretion and improve Pd-EPS yield. In this process, bi-metallic (FePd-EPS) biomaterials were produced for the first time. The morphology of bi-metallic EPS, and the chemical state of the two metals in the FePd-EPS, are investigated by transmission electron microscopy, Fourier transform infra-red spectroscopy, micro-X-ray fluorescence, and X-ray absorption spectroscopy methods (XANES and EXAFS), and compared with mono-metallic Pd-EPS and Fe-EPS complexes. Iron in FePd-EPS is in the mineralized form of iron oxides/hydroxides, predominantly in the form of Fe(3+), with a small amount of Fe(2+) in the structure, most probably a mixture of different nano-crystalline iron oxides and hydroxides, as in mono-metallic Fe-EPS. Palladium is found as Pd(0) in the form of metallic nanoparticles with face-centred cubic structure in both bi-metallic (FePd-EPS) and mono-metallic (Pd-EPS) species. In bi-metallic species, Pd and Fe nanoparticles agglomerate in larger clusters, but they remain spatially separated. The catalytic ability of bi-metallic species (FePd-EPS) in a hydrodechlorination reaction is improved in comparison with mono-metallic Pd-EPS.

Analysis of the 16S–23S rRNA Gene Internal Transcribed Spacer Region in Klebsiella Species▿

PubMed Central

Wang, Min; Cao, Boyang; Yu, Qunfang; Liu, Lei; Gao, Qili; Wang, Lei; Feng, Lu

2008-01-01

The 16S-23S rRNA gene internal transcribed spacer (ITS) regions of Klebsiella spp., including Klebsiella pneumoniae subsp. pneumoniae, Klebsiella pneumoniae subsp. ozaenae, Klebsiella pneumoniae subsp. rhinoscleromatis, Klebsiella oxytoca, Klebsiella planticola, Klebsiella terrigena, and Klebsiella ornithinolytica, were characterized, and the feasibility of using ITS sequences to discriminate Klebsiella species and subspecies was explored. A total of 336 ITS sequences from 21 representative strains and 11 clinical isolates of Klebsiella were sequenced and analyzed. Three distinct ITS types—ITSnone (without tRNA genes), ITSglu [with a tRNAGlu (UUC) gene], and ITSile+ala [with tRNAIle (GAU) and tRNAAla (UGC) genes]—were detected in all species except for K. pneumoniae subsp. rhinoscleromatis, which has only ITSglu and ITSile+ala. The presence of ITSnone in Enterobacteriaceae had never been reported before. Both the length and the sequence of each ITS type are highly conserved within the species, with identity levels from 0.961 to 1.000 for ITSnone, from 0.967 to 1.000 for ITSglu, and from 0.968 to 1.000 for ITSile+ala. Interspecies sequence identities range from 0.775 to 0.989 for ITSnone, from 0.798 to 0.997 for ITSglu, and from 0.712 to 0.985 for ITSile+ala. Regions with significant interspecies variations but low intraspecies polymorphisms were identified; these may be targeted in the design of probes for the identification of Klebsiella to the species level. Phylogenetic analysis based on ITS regions reveals the relationships among Klebsiella species similarly to that based on 16S rRNA genes. PMID:18753345

Surveillance of multidrug resistant uropathogenic bacteria in hospitalized patients in Indian

PubMed Central

Mishra, Monali Priyadarsini; Debata, Nagen Kumar; Padhy, Rabindra Nath

2013-01-01

Objective To record surveillance, antibiotic resistance of uropathogens of hospitalized patients over a period of 18 months. Methods Urine samples from wards and cabins were used for isolating urinary tract infection (UTI)-causing bacteria that were cultured on suitable selective media and identified by biochemical tests; and their antibiograms were ascertained by Kirby-Bauer's disc diffusion method, in each 6-month interval of the study period, using 18 antibiotics of five different classes. Results From wards and cabins, 1 245 samples were collected, from which 996 strains of bacteria belonging to 11 species were isolated, during April 2011 to September 2012. Two Gram-positive, Staphylococcus aureus (S. aureus) and Enterococcus faecalis (E. faecalis), and nine Gram-negative bacteria, Acinetobacter baumannii, Citrobacter sp., Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa were isolated. Both S. aureus and E. faecalis were vancomycin resistant, and resistant-strains of all pathogens increased in each 6-month period of study. Particularly, all Gram-negatives were resistant to nitrofurantoin and co-trimoxazole, the most preferred antibiotics of empiric therapy for UTI. Conclusions Antibiograms of 11 UTI-causing bacteria recorded in this study indicated moderately higher numbers of strains resistant to each antibiotic studied, generating the fear of precipitating fervent episodes in public health particularly with bacteria, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and S. aureus. Moreover, vancomycin resistance in strains of S. aureus and E. faecalis is a matter of concern. PMID:23620859

[Prevalence of ESBL-positive enterobacteriaceae in large moravian hospitals (Czech Republic)].

PubMed

Kolář, Milan; Chromá, Magdaléna; Hricová, Kristýna; Husičková, Vendula; Lovečková, Yvona; Chmelařová, Eva; Bartoníková, Nataša; Rybníkářová, Petra

2010-10-01

bacterial infections have become an important issue in current medicine. Recently, their frequency and severity have significantly increased as a result of the rising number of resistant bacteria. One of important mechanisms of resistance is production of broad-spectrum beta-lactamases, namely the ESBL type. The study aimed at determining the frequency of ESBL-positive Enterobacteriaceae in three large hospitals in Moravia, the eastern part of the Czech Republic. enterobacteriaceae were isolated from clinical material obtained from patients hospitalized in the University Hospital Olomouc, Teaching Hospital Ostrava and Bata Regional Hospital Zlín throughout 2009. Standard microbiology techniques were used for identification. The production of ESBLs was determined by the modified Double-Disk Synergy Test. ESBL-positive isolates of Escherichia coli from ICU patients were subjected to basic genetic analysis. during the study period, a total of 12,922 strains from the Enterobacteriaceae family were detected. The ESBL phenotype was found in 907 cases, i.e. 7 % of all isolates. The most prevalent species of ESBL-producing Enterobacteriaceae were Klebsiella pneumoniae, Klebsiella oxytoca and Escherichia coli. A comparison of general wards and ICUs revealed a higher percentage of ESBL-positive strains of Klebsiella pneumoniae and a lower proportion of ESBL-positive Escherichia coli isolates in intensive care patients. When assessing the patients' clinical material, ESBL-producing strains were most frequently detected in urine. Genetic analysis of ESBL-positive Escherichia coli strains from ICU patients revealed the CTX-M type of ESBL production in most isolates.

Characteristics and management of Enterobacteriaceae harboring IMP-4 or IMP-8 carbapenemase in a tertiary hospital.

PubMed

Pang, Feng; Jia, Xiu-Qin; Song, Zhen-Zhu; Li, Yan-Hua; Wang, Bin; Zhao, Qi-Gang; Wang, Chuan-Xin; Zhang, Yi; Wang, Le-Xin

2016-03-01

The emergence of Enterobacteriaceae harboring IMP-4 or IMP-8 carbapenemases is rare. We report an occurrence of Enterobacteriaceae harboring IMP-4 or IMP-8 carbapenemases in a Chinese tertiary care hospital from November 2010 to December 2012. The clinical characteristics of 30 patients were described. The genetic relationship of isolates was determined by pulsed-field gel electrophoresis (PFGE). Carbapenemases were detected by modified Hodge test (MHT) and polymerase chain reactions (PCRs). Amplicons were sequenced and blasted to determine the genotype. Most infected patients were from intensive care unit and had complex and serious underlying illnesses requiring mechanical ventilation. PFGE revealed that Klebsiella pneumoniae showed two major PFGE types. Two Klebsiella oxytoca had an indistinguishable PFGE pattern, while four Enterobacter cloacae were different strains. The sequencing studies showed Enterobacteriaceae harboring IMP-4 or IMP-8 carbapenemase in the 23 infected patients. The majority of patients had infections with the carbapenemase-producing Enterobacteriaceae (CPE) strain, most were successfully treated with a range of antibiotics and discharged. It is important to maintain a high index of suspicion to screen for carbapenemase-producing Enterobacteriaceae strains. Rapid identification of these strains and implementation of stringent procedures are the key to prevent major outbreaks in a hospital setting.

Enhancement of 2,3-Butanediol Production by Klebsiella oxytoca PTCC 1402

PubMed Central

Anvari, Maesomeh; Safari Motlagh, Mohammad Reza

2011-01-01

Optimal operating parameters of 2,3-Butanediol production using Klebsiella oxytoca under submerged culture conditions are determined by using Taguchi method. The effect of different factors including medium composition, pH, temperature, mixing intensity, and inoculum size on 2,3-butanediol production was analyzed using the Taguchi method in three levels. Based on these analyses the optimum concentrations of glucose, acetic acid, and succinic acid were found to be 6, 0.5, and 1.0 (% w/v), respectively. Furthermore, optimum values for temperature, inoculum size, pH, and the shaking speed were determined as 37°C, 8 (g/L), 6.1, and 150 rpm, respectively. The optimal combinations of factors obtained from the proposed DOE methodology was further validated by conducting fermentation experiments and the obtained results revealed an enhanced 2,3-Butanediol yield of 44%. PMID:21318172

Analysis of microbial diversity in Shenqu with different fermentation times by PCR-DGGE.

PubMed

Liu, Tengfei; Jia, Tianzhu; Chen, Jiangning; Liu, Xiaoyu; Zhao, Minjie; Liu, Pengpeng

Shenqu is a fermented product that is widely used in traditional Chinese medicine (TCM) to treat indigestion; however, the microbial strains in the fermentation process are still unknown. The aim of this study was to investigate microbial diversity in Shenqu using different fermentation time periods. DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis) profiles indicated that a strain of Pediococcus acidilactici (band 9) is the predominant bacteria during fermentation and that the predominant fungi were uncultured Rhizopus, Aspergillus oryzae, and Rhizopus oryzae. In addition, pathogenic bacteria, such as Enterobacter cloacae, Klebsiella oxytoca, Erwinia billingiae, and Pantoea vagan were detected in Shenqu. DGGE analysis showed that bacterial and fungal diversity declined over the course of fermentation. This determination of the predominant bacterial and fungal strains responsible for fermentation may contribute to further Shenqu research, such as optimization of the fermentation process. Copyright © 2017. Published by Elsevier Editora Ltda.

Indole can act as an extracellular signal to regulate biofilm formation of Escherichia coli and other indole-producing bacteria.

PubMed

Martino, P Di; Fursy, R; Bret, L; Sundararaju, B; Phillips, R S

2003-07-01

We demonstrated previously that genetic inactivation of tryptophanase is responsible for a dramatic decrease in biofilm formation in the laboratory strain Escherichia coli S17-1. In the present study, we tested whether the biochemical inhibition of tryptophanase, with the competitive inhibitor oxindolyl-L-alanine, could affect polystyrene colonization by E. coli and other indole-producing bacteria. Oxindolyl-L-alanine inhibits, in a dose-dependent manner, indole production and biofilm formation by strain S17-1 grown in Luria-Bertani (LB) medium. Supplementation with indole at physiologically relevant concentrations restores biofilm formation by strain S17-1 in the presence of oxindolyl-L-alanine and by mutant strain E. coli 3714 (S17-1 tnaA::Tn5) in LB medium. Oxindolyl-L-alanine also inhibits the adherence of S17-1 cells to polystyrene for a 3-h incubation time, but mutant strain 3714 cells are unaffected. At 0.5 mg/mL, oxindolyl-L-alanine exhibits inhibitory activity against biofilm formation in LB medium and in synthetic urine for several clinical isolates of E. coli, Klebsiella oxytoca, Citrobacter koseri, Providencia stuartii, and Morganella morganii but has no affect on indole-negative Klebsiella pneumoniae strains. In conclusion, these data suggest that indole, produced by the action of tryptophanase, is involved in polystyrene colonization by several indole-producing bacterial species. Indole may act as a signalling molecule to regulate the expression of adhesion and biofilm-promoting factors.

Characterization of biogenic ferrihydrite nanoparticles by means of SAXS, SRD and IBA methods

NASA Astrophysics Data System (ADS)

Balasoiu, M.; Kichanov, S.; Pantelica, A.; Pantelica, D.; Stolyar, S.; Iskhakov, R.; Aranghel, D.; Ionescu, P.; Badita, C. R.; Kurkin, S.; Orelovich, O.; Tiutiunikov, S.

2018-03-01

Investigations of biogenic ferrihydrite nanoparticles produced by bacteria Klebsiella oxytoca by applying small angle X-ray scattering, synchrotron radiation diffraction and ion beam analysis methods are reviewed. Different experimental data processing methods are used and analyzed.

Update of incidence and antimicrobial susceptibility trends of Escherichia coli and Klebsiella pneumoniae isolates from Chinese intra-abdominal infection patients.

PubMed

Zhang, Hui; Yang, Qiwen; Liao, Kang; Ni, Yuxing; Yu, Yunsong; Hu, Bijie; Sun, Ziyong; Huang, Wenxiang; Wang, Yong; Wu, Anhua; Feng, Xianju; Luo, Yanping; Chu, Yunzhuo; Chen, Shulan; Cao, Bin; Su, Jianrong; Duan, Qiong; Zhang, Shufang; Shao, Haifeng; Kong, Haishen; Gui, Bingdong; Hu, Zhidong; Badal, Robert; Xu, Yingchun

2017-12-18

To evaluate in vitro susceptibilities of aerobic and facultative Gram-negative bacterial (GNB) isolates from intra-abdominal infections (IAIs) to 12 selected antimicrobials in Chinese hospitals from 2012 to 2014. Hospital acquired (HA) and community acquired (CA) IAIs were collected from 21 centers in 16 Chinese cities. Extended spectrum beta-lactamase (ESBL) status and antimicrobial susceptibilities were determined at a central laboratory using CLSI broth microdilution and interpretive standards. From all isolated strains the Enterobacteriaceae (81.1%) Escherichia coli accounted for 45.4% and Klebsiella pneumoniae for 20.1%, followed by Enterobacter cloacae (5.2%), Proteus mirabilis (2.1%), Citrobacter freundii (1.8%), Enterobacter aerogenes (1.8%), Klebsiella oxytoca (1.4%), Morganella morganii (1.2%), Serratia marcescens (0.7%), Citrobacter koseri (0.3%), Proteus vulgaris (0.3%) and others (1.0%). Non- Enterobacteriaceae (18.9%) included Pseudomonas aeruginosa (9.8%), Acinetobacter baumannii (6.7%), Stenotrophomonas maltophilia (0.9%), Aeromonas hydrophila (0.4%) and others (1.1%). ESBL-screen positive Escherichia coli isolates (ESBL+) showed a decreasing trend from 67.5% in 2012 to 58.9% in 2014 of all Escherichia coli isolates and the percentage of ESBL+ Klebsiella pneumoniae isolates also decreased from 2012 through 2014 (40.4% to 26.6%), which was due to reduced percentages of ESBL+ isolates in HA IAIs for both bacteria. The overall susceptibilities of all 5160 IAI isolates were 87.53% to amikacin (AMK), 78.12% to piperacillin-tazobactam (TZP) 81.41% to imipenem (IMP) and 73.12% to ertapenem (ETP). The susceptibility of ESBL-screen positive Escherichia coli strains was 96.77%-98.8% to IPM, 91.26%-93.16% to ETP, 89.48%-92.75% to AMK and 84.86%-89.34% to TZP, while ESBL-screen positive Klebsiella pneumoniae strains were 70.56%-80.15% susceptible to ETP, 80.0%-87.5% to IPM, 83.82%-87.06% to AMK and 63.53%-68.38% to TZP within the three year study. Susceptibilities to all cephalosporins and fluoroquinolones were less than 50% beside 66.5% and 56.07% to cefoxitin (FOX) for ESBL+ Escherichia coli and Klebsiella pneumoniae strains respectively. The total ESBL+ rates decreased in Escherichia coli and Klebsiella pneumoniae IAI isolates due to fewer prevalence in HA infections. IPM, ETP and AMK were the most effective antimicrobials against ESBL+ Escherichia coli and Klebsiella pneumoniae IAI isolates in 2012-2014 and a change of fluoroquinolone regimens for Chinese IAIs is recommended.

Single molecule sequencing to track plasmid diversity of hospital-associated carbapenemase-producing Enterobacteriaceae

PubMed Central

Conlan, Sean; Thomas, Pamela J.; Deming, Clayton; Park, Morgan; Lau, Anna F.; Dekker, John P.; Snitkin, Evan S.; Clark, Tyson A.; Luong, Khai; Song, Yi; Tsai, Yu-Chih; Boitano, Matthew; Gupta, Jyoti; Brooks, Shelise Y.; Schmidt, Brian; Young, Alice C.; Thomas, James W.; Bouffard, Gerard G.; Blakesley, Robert W.; Mullikin, James C.; Korlach, Jonas; Henderson, David K.; Frank, Karen M.; Palmore, Tara N.; Segre, Julia A.

2014-01-01

Public health officials have raised concerns that plasmid transfer between Enterobacteriaceae species may spread resistance to carbapenems, an antibiotic class of last resort, thereby rendering common healthcare-associated infections nearly impossible to treat. We performed comprehensive surveillance and genomic sequencing to identify carbapenem-resistant Enterobacteriaceae in the NIH Clinical Center patient population and hospital environment in order to to articulate the diversity of carbapenemase-encoding plasmids and survey the mobility of and assess the mobility of these plasmids between bacterial species. We isolated a repertoire of carbapenemase-encoding Enterobacteriaceae, including multiple strains of Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, Enterobacter cloacae, Citrobacter freundii, and Pantoea species. Long-read genome sequencing with full end-to-end assembly revealed that these organisms carry the carbapenem-resistance genes on a wide array of plasmids. Klebsiella pneumoniae and Enterobacter cloacae isolated simultaneously from a single patient harbored two different carbapenemase-encoding plasmids, overriding the epidemiological scenario of plasmid transfer between organisms within this patient. We did, however, find evidence supporting horizontal transfer of carbapenemase-encoding plasmids between Klebsiella pneumoniae, Enterobacter cloacae and Citrobacter freundii in the hospital environment. Our comprehensive sequence data, with full plasmid identification, challenges assumptions about horizontal gene transfer events within patients and identified wider possible connections between patients and the hospital environment. In addition, we identified a new carbapenemase-encoding plasmid of potentially high clinical impact carried by Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae and Pantoea species, from unrelated patients and the hospital environment. PMID:25232178

Cultivable endophytic bacteria from leaf bases of Agave tequilana and their role as plant growth promoters

PubMed Central

Martínez-Rodríguez, Julia del C.; la Mora-Amutio, Marcela De; Plascencia-Correa, Luis A.; Audelo-Regalado, Esmeralda; Guardado, Francisco R.; Hernández-Sánchez, Elías; Peña-Ramírez, Yuri J.; Escalante, Adelfo; Beltrán-García, Miguel J.; Ogura, Tetsuya

2014-01-01

Agave tequilana Weber var. ‘Azul’ is grown for the production of tequila, inulin and syrup. Diverse bacteria inhabit plant tissues and play a crucial role for plant health and growth. In this study culturable endophytic bacteria were extracted from leaf bases of 100 healthy Agave tequilana plants. In plant tissue bacteria occurred at mean population densities of 3 million CFU/g of fresh plant tissue. Three hundred endophytic strains were isolated and 16s rDNA sequences grouped the bacteria into eight different taxa that shared high homology with other known sequences. Bacterial endophytes were identified as Acinectobacter sp., A. baumanii, A. bereziniae, Cronobacter sakazakii, Enterobacter hormaechei, Bacillus sp. Klebsiella oxytoca, Pseudomonas sp., Enterococcus casseliflavus, Leuconostoc mesenteroides subsp. mesenteroides and Gluconobacter oxydans. Isolates were confirmed to be plant growth promoting bacteria (PGPB) by their capacities for nitrogen fixation, auxin production, phosphate solubilization, or antagonism against Fusarium oxysporum AC132. E. casseliflavus JM47 and K. oxytoca JM26 secreted the highest concentrations of IAA. The endophyte Acinectobacter sp. JM58 exhibited the maximum values for nitrogen fixation and phosphate solubilization index (PSI). Inhibition of fungi was found in Pseudomonas sp. JM9p and K. oxytoca JM26. Bacterial endophytes show promise for use as bio-inoculants for agave cultivation. Use of endophytes to enhance cultivation of agave may be particularly important for plants produced by micropropagation techniques, where native endophytes may have been lost. PMID:25763038

Cultivable endophytic bacteria from leaf bases of Agave tequilana and their role as plant growth promoters.

PubMed

Martínez-Rodríguez, Julia del C; De la Mora-Amutio, Marcela; Plascencia-Correa, Luis A; Audelo-Regalado, Esmeralda; Guardado, Francisco R; Hernández-Sánchez, Elías; Peña-Ramírez, Yuri J; Escalante, Adelfo; Beltrán-García, Miguel J; Ogura, Tetsuya

2014-01-01

Agave tequilana Weber var. 'Azul' is grown for the production of tequila, inulin and syrup. Diverse bacteria inhabit plant tissues and play a crucial role for plant health and growth. In this study culturable endophytic bacteria were extracted from leaf bases of 100 healthy Agave tequilana plants. In plant tissue bacteria occurred at mean population densities of 3 million CFU/g of fresh plant tissue. Three hundred endophytic strains were isolated and 16s rDNA sequences grouped the bacteria into eight different taxa that shared high homology with other known sequences. Bacterial endophytes were identified as Acinectobacter sp., A. baumanii, A. bereziniae, Cronobacter sakazakii, Enterobacter hormaechei, Bacillus sp. Klebsiella oxytoca, Pseudomonas sp., Enterococcus casseliflavus, Leuconostoc mesenteroides subsp. mesenteroides and Gluconobacter oxydans. Isolates were confirmed to be plant growth promoting bacteria (PGPB) by their capacities for nitrogen fixation, auxin production, phosphate solubilization, or antagonism against Fusarium oxysporum AC132. E. casseliflavus JM47 and K. oxytoca JM26 secreted the highest concentrations of IAA. The endophyte Acinectobacter sp. JM58 exhibited the maximum values for nitrogen fixation and phosphate solubilization index (PSI). Inhibition of fungi was found in Pseudomonas sp. JM9p and K. oxytoca JM26. Bacterial endophytes show promise for use as bio-inoculants for agave cultivation. Use of endophytes to enhance cultivation of agave may be particularly important for plants produced by micropropagation techniques, where native endophytes may have been lost.

Emergence of serine carbapenemases (KPC and SME) among clinical strains of Enterobacteriaceae isolated in the United States Medical Centers: report from the MYSTIC Program (1999-2005).

PubMed

Deshpande, Lalitagauri M; Rhomberg, Paul R; Sader, Helio S; Jones, Ronald N

2006-12-01

Among 8885 Enterobacteriaceae tested in the 1999 to 2005 period as part of the USA Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program, 51 strains with increased imipenem and meropenem MIC values (> or =2 microg/mL) were detected. bla(KPC) was identified from 28 Klebsiella pneumoniae from 3 medical centers in the New York City area (8 ribotypes), 2 Klebsiella oxytoca from Arkansas (same ribotype), 7 Citrobacter freundii (6 from New York [5 ribotypes] and 1 from Delaware), 4 Enterobacter spp. from New York (2 species, different ribotypes), 3 Escherichia coli (2 from New York and 1 from Ohio, same ribotype), and 1 Serratia marcescens (New York). Sequencing confirmed KPC-2 or -3 in all of the strains. S. marcescens strains harboring SME-1 (2 isolates, same ribotype) and SME-2 (1 isolate) were identified from medical centers in Illinois and Washington state, respectively. Our results indicate that bla(KPC-2/3) has emerged widely (New York City area, Arkansas, Delaware, and Ohio) among Enterobacteriaceae isolated in the MYSTIC Program participant sites (2000-2005) and continues to be isolated from multiple species, as a result of clonal expansion and horizontal gene transfer. The escalating occurrence (0.35%) of serine carbapenemases could compromise the role of carbapenems and other beta-lactams in USA clinical practice although observed in only a few locations to date.

Antimicrobial and Herbal Drug Resistance in Enteric Bacteria Isolated from Faecal Droppings of Common House Lizard/Gecko (Hemidactylus frenatus).

PubMed

Singh, Bhoj R; Singh, Vidya; Ebibeni, N; Singh, Raj K

2013-01-01

From 194 faecal dropping samples of common house geckos collected from offices (60), houses (88), integrated farm units (IFS,18) and hostels, guest houses, and dining rooms of different canteen/mess (HGM, 28), 326 bacterial isolates of enteric bacteria belonging to 17 genera and 34 species were detected. Escherichia coli were the most frequently (39) isolated followed by Citrobacter freundii (33), Klebsiella pneumonia (27), Salmonella indica (12), Enterobacter gergoviae (12), and Ent. agglomerans (11). Other important bacteria isolated from gecko droppings were Listonella damsela (2), Raoultella terrigena (3), S. salamae (2), S. houtenae (3), Edwardsiella tarda (4), Edwardsiella hoshinae (1), and Klebsiella oxytoca (2). Of the 223 isolates tested for antimicrobial drug sensitivity, 27 (12.1%) had multiple drug resistance (MDR). None of the salmonellae or edwardsiellae had MDR however, MDR strains were significantly more common among Escherichia spp. (P = 1.9 × 10(-5)) and isolates from IFS units (P = 3.58 × 10(-23)). The most effective herbal drug, Ageratum conyzoides extract, inhibited growth of only 27.8% of strains tested followed by ethanolic extract of Zanthoxylum rhetsa (13.9%), eucalyptus oil (5.4%), patchouli oil (5.4%), lemongrass oil (3.6%), and sandalwood oil (3.1%), and Artemisia vulgaris essential oil (3.1%).

Use of WGS data for investigation of a long-term NDM-1-producing Citrobacter freundii outbreak and secondary in vivo spread of blaNDM-1 to Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca.

PubMed

Hammerum, Anette M; Hansen, Frank; Nielsen, Hans Linde; Jakobsen, Lotte; Stegger, Marc; Andersen, Paal S; Jensen, Paw; Nielsen, Tue Kjærgaard; Hansen, Lars Hestbjerg; Hasman, Henrik; Fuglsang-Damgaard, David

2016-11-01

An outbreak of NDM-1-producing Citrobacter freundii and possible secondary in vivo spread of bla NDM-1 to other Enterobacteriaceae were investigated. From October 2012 to March 2015, meropenem-resistant Enterobacteriaceae were detected in 45 samples from seven patients at Aalborg University Hospital, Aalborg, Denmark. In silico resistance genes, Inc plasmid types and STs (MLST) were obtained from WGS data from 24 meropenem-resistant isolates (13 C. freundii, 6 Klebsiella pneumoniae, 4 Escherichia coli and 1 Klebsiella oxytoca) and 1 meropenem-susceptible K. oxytoca. The sequences of the meropenem-resistant C. freundii isolates were compared by phylogenetic analyses. In vitro susceptibility to 21 antimicrobial agents was tested. Furthermore, in vitro conjugation and plasmid characterization was performed. From the seven patients, 13 highly clonal ST18 NDM-1-producing C. freundii were isolated. The ST18 NDM-1-producing C. freundii isolates were only susceptible to tetracycline, tigecycline, colistin and fosfomycin (except for the C. freundii isolates from Patient 2 and Patient 7, which were additionally resistant to tetracycline). The E. coli and K. pneumoniae from different patients belonged to different STs, indicating in vivo transfer of bla NDM-1 in the individual patients. This was further supported by in vitro conjugation and detection of a 154 kb IncA/C2 plasmid with bla NDM-1 . Patient screenings failed to reveal any additional cases. None of the patients had a history of recent travel abroad and the source of the bla NDM-1 plasmid was unknown. To our knowledge, this is the first report of an NDM-1-producing C. freundii outbreak and secondary in vivo spread of an IncA/C2 plasmid with bla NDM-1 to other Enterobacteriaceae. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

In vitro activity and beta-lactamase stability of a new difluoro oxacephem, 6315-S.

PubMed Central

Neu, H C; Chin, N X

1986-01-01

6315-S, a novel difluoromethyl thioacetamido oxacephem, had in vitro activity comparable to that of cefotaxime and moxalactam against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Klebsiella oxytoca, Citrobacter diversus, Salmonella spp., and Shigella spp., inhibiting 90% at less than or equal to 0.25 microgram/ml. It inhibited piperacillin- and cefoperazone-resistant isolates in these species. 6315-S did not inhibit cefotaxime- or moxalactam-resistant Citrobacter freundii, Enterobacter aerogenes, or Enterobacter cloacae (MICs for 90% of the strains tested were greater than or equal to 16 micrograms/ml). Proteus vulgaris resistant to cefotaxime was inhibited. Pseudomonas species and Acinetobacter species were resistant (MICs greater than 64 micrograms/ml). MICs for 90% of the Staphylococcus aureus and S. epidermidis isolates were 4 micrograms/ml. 6315-S was highly active against anaerobic species of Clostridium, Fusobacterium, Bacteroides, and peptostreptococci and was superior to other agents against these organisms. 6315-S was not hydrolyzed by the major plasmid and chromosomal beta-lactamases, but it induced chromosomal beta-lactamases in Enterobacter cloacae and Pseudomonas aeruginosa. PMID:3492172

Epidemiological study of klebsiella infection in the special care baby unit of a London hospital

PubMed Central

Riser, EVE; Noone, Paul; Howard, Frances M

1980-01-01

Of the babies admitted to the Special Care Baby Unit of the Royal Free Hospital over 20 months, 10·2% were infected or colonised by klebsiella. The fluorescent antibody technique was used to identify epidemics caused by three strains: capsular type 8 K. aerogenes, type 68 K. oxytoca, or type 13 K. aerogenes, each of which was predominant at a different time, exhibited a difference in virulence, and showed a predilection for different sites of infection. Intestinal colonisation was frequently followed by the presence of sepsis in other sites by the same capsular type. Antibiotic administration led to a higher incidence of klebsiella infection, while the widespread use of compounds containing hexachlorophane could have contributed to skin colonisation and infection by klebsiella. An environmental survey indicated that 1% Hycolin failed to disinfect the incubators, that the babies were the reservoirs of the organisms, and that transmission was due to inadequate hand-washing of nurses and mothers. The mothers were found to have been uninformed of hygienic techniques. They were observed in various practices which could have contributed to the spread of the organism, including contaminating communal areas and handling babies other than their own. It has been recommended that the mothers of premature infants be instructed in the hygienic measures required in dealing with this susceptible population and that the nursing and medical staff be more strict in their own observance of these procedures. PMID:7400339

EFFECTS OF VELOCITY ON THE TRANSPORT OF TWO BACTERIA THROUGH SATURATED SAND. GROUND WATER.

EPA Science Inventory

Transport of the bacteria Klebsiella oxytoca and Burkholderia cepacia G4PR1 (G4PR1) was investigated in column experiments conducted under conditions that allowed us to quantify sorption under a range of ground water velocities. Column experiments (33 mm I.D. X 114 mm long colu...

Biological activities of some Acacia spp. (Fabaceae) against new clinical isolates identified by ribosomal RNA gene-based phylogenetic analysis.

PubMed

Mahmoud, Mahmoud Fawzy; Alrumman, Sulaiman Abdullah; Hesham, Abd El-Latif

2016-01-01

Nowadays,most of the pathogenic bacteria become resistant to antibiotics. Therefore,the pharmaceutical properties of the natural plant extracts have become of interest to researchers as alternative antimicrobial agents. In this study,antibacterial activities of extract gained from Acacia etbaica, Acacia laeta, Acacia origena and Acacia pycnantha have been evaluated against isolated pathogenic bacteria (Strains MFM-01, MFM-10 and AH-09) using agar well diffusion methods.The bacterial strains were isolated from infected individuals,and their exact identification was detected on the basis of 16S rRNA gene amplification and sequence determination. Alignment results and the comparison of 16 SrRN A gene sequences of the isolates to 16 SrRN A gene sequences available in Gen Bank data base as well as the phylogenetic analysis confirmed the accurate position of the isolates as Klebsiella oxytoca strain MFM-01, Staphylococcus aureus strain MFM-10 and Klebsiella pneumoniae strain AH-09. Except for cold water, all tested solvents (Chloroform, petroleum ether, methanol, diethyl ether, and acetone) showed variation in their activity against studied bacteria. GC-MS analysis of ethanol extracts showed that four investigated Acacia species have different phyto components. Eight important pharmaceutical components were found in the legume of Acacia etbaica, seven in the legume of Acacia laeta, fifteen in the legume of Acacia origena and nine in the leaves of Acacia pycnantha. A dendrogram was constructed based on chemical composition, revealed that Acacia laeta is more closely related to Acacia etbaica forming on eclade, whereas Acacia origena less similar to other species. Our results demonstrated that, investigated plants and chemical compounds present could be used as promising antibacterial agents.

Metal-resistant rhizobacteria isolates improve Mucuna deeringiana phytoextraction capacity in multi-metal contaminated soils from a gold mining area.

PubMed

Boechat, Cácio Luiz; Giovanella, Patricia; Amorim, Magno Batista; de Sá, Enilson Luiz Saccol; de Oliveira Camargo, Flávio Anastácio

2017-01-01

Phytoremediation consists of biological techniques for heavy metal remediation, which include exploring the genetic package of vegetable species to remove heavy metals from the environment. The goals of this study were to investigate heavy metal and bioaugmentation effects on growth and nutrient uptake by Mucuna deeringiana; to determine the metal translocation factor and bioconcentration factor and provide insight for using native bacteria to enhance heavy metal accumulation. The experiment was conducted under greenhouse conditions using a 2 × 4 factorial scheme with highly and slightly contaminated soil samples and inoculating M. deeringiana with three highly lead (Pb +2 )-resistant bacteria Kluyvera intermedia (Ki), Klebsiella oxytoca (Ko), and Citrobacter murliniae (Cm) isolated from the rhizosphere of native plants identified as Senecio brasiliensis (Spreng.) Less., Senecio leptolobus DC., and Baccharis trimera (Less) DC., respectively. The increased heavy metal concentrations in soil samples do not decrease the root dry mass of M. deeringiana, concerning the number and dry weight of nodules. The shoot dry mass is reduced by the increasing concentration of heavy metals in soil associated with Kluyvera intermedia and Klebsiella oxytoca bacteria. The number of nodules is affected by heavy metals associated with Citrobacter murliniae bacteria. The bacteria K. intermedia, C. murliniae, and K. oxytoca increase the lead and cadmium available in the soil and enhanced metal uptake by Mucuna deeringiana. The M. deeringiana specie has characteristics that make it hyperaccumulate copper and zinc. The translocation and bioconcentration factors for M. deeringiana characterize it as a promising candidate to phytostabilize multi-metal contaminated soils.

Evaluation of parameters affecting quantitative detection of Escherichia coli O157 in enriched water samples using immunomagnetic electrochemiluminescence.

PubMed

Shelton, Daniel R; Van Kessel, Jo Ann S; Wachtel, Marian R; Belt, Kenneth T; Karns, Jeffrey S

2003-12-01

We report here the use of immunomagnetic (IM) electrochemiluminescence (ECL) for quantitative detection of Esherichia coli O157:H7 in water samples following enrichment in minimal lactose broth (MLB). IM beads prepared in-house with four commercial anti-O157 monoclonal antibodies were compared for efficiency of cell capture. IM-ECL responses for E. coli O157:H7 (strain SEA13B88) were similar for all four commercial anti-O157 LPS monoclonal antibodies. The ECL signal was linearly correlated with E. coli O157:H7 cell concentration, indicating a constant ECL response per cell. Twenty-two strains of E. coli O157:H7 or O157:NM gave comparable ECL signals using IM beads prepared in-house. To assess the potential for interference from background bacteria in MLB-enriched water samples, 10(4) cells of E. coli O157:H7 (strain SEA13B88) were added to enriched samples prior to analysis. There was considerable variability in recovery of E. coli O157:H7 cells; net ECL signals ranged from 1% to 100% of expected values (i.e., percent inhibition from 0% to 99%). Cultures of Klebsiella pneumoniae, Klebsiella oxytoca, and Enterobacter cloacae, subsequently isolated from MLB-enriched water samples via IM separation (IMS), were observed to interfere with the binding of E. coli O157:H7 cells to IM beads. Recoveries of 10(4) E. coli O157:H7 cells were

Antagonistic effect of Lactobacillus strains against gas-producing coliforms isolated from colicky infants

PubMed Central

2011-01-01

Background Infantile colic is a common disturb within the first 3 months of life, nevertheless the pathogenesis is incompletely understood and treatment remains an open issue. Intestinal gas production is thought to be one of the causes of abdominal discomfort in infants suffering from colic. However, data about the role of the amount of gas produced by infants' colonic microbiota and the correlation with the onset of colic symptoms are scanty. The benefit of supplementation with lactobacilli been recently reported but the mechanisms by which they exert their effects have not yet been fully defined. This study was performed to evaluate the interaction between Lactobacillus spp. strains and gas-forming coliforms isolated from stools of colicky infants. Results Strains of coliforms were isolated from stools of 45 colicky and 42 control breastfed infants in McConkey Agar and identified using PCR with species-specific primers, and the BBL™ Enterotube™ II system for Enterobacteriaceae. Gas-forming capability of coliforms was assessed in liquid cultures containing lactose as sole carbon source. The average count of total coliforms in colicky infants was significantly higher than controls: 5.98 (2.00-8.76) log10 vs 3.90 (2.50-7.10) CFU/g of faeces (p = 0.015). The following strains were identified: Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae and Enterococcus faecalis. Then, 27 Lactobacillus strains were tested for their antagonistic effect against coliforms both by halo-forming method and in liquid co-cultures. Lactobacillus delbrueckii subsp.delbrueckii DSM 20074 and L. plantarum MB 456 were able to inhibit all coliforms strains (halo-forming method), also in liquid co-cultures, thus demonstrating an antagonistic activity. Conclusions This study shows that two out of 27 strains of Lactobacillus examined possess an antimicrobial effect against six species of gas-forming coliforms isolated from colicky infants. Our findings may stimulate new researches to identify which Lactobacillus strains can improve colicky symptoms by acting on coliforms gut colonization. PMID:21718486

Antagonistic effect of Lactobacillus strains against gas-producing coliforms isolated from colicky infants.

PubMed

Savino, Francesco; Cordisco, Lisa; Tarasco, Valentina; Locatelli, Emanuela; Di Gioia, Diana; Oggero, Roberto; Matteuzzi, Diego

2011-06-30

Infantile colic is a common disturb within the first 3 months of life, nevertheless the pathogenesis is incompletely understood and treatment remains an open issue. Intestinal gas production is thought to be one of the causes of abdominal discomfort in infants suffering from colic. However, data about the role of the amount of gas produced by infants' colonic microbiota and the correlation with the onset of colic symptoms are scanty. The benefit of supplementation with lactobacilli been recently reported but the mechanisms by which they exert their effects have not yet been fully defined. This study was performed to evaluate the interaction between Lactobacillus spp. strains and gas-forming coliforms isolated from stools of colicky infants. Strains of coliforms were isolated from stools of 45 colicky and 42 control breastfed infants in McConkey Agar and identified using PCR with species-specific primers, and the BBL™ Enterotube™ II system for Enterobacteriaceae. Gas-forming capability of coliforms was assessed in liquid cultures containing lactose as sole carbon source. The average count of total coliforms in colicky infants was significantly higher than controls: 5.98 (2.00-8.76) log10 vs 3.90 (2.50-7.10) CFU/g of faeces (p = 0.015). The following strains were identified: Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae and Enterococcus faecalis. Then, 27 Lactobacillus strains were tested for their antagonistic effect against coliforms both by halo-forming method and in liquid co-cultures. Lactobacillus delbrueckii subsp. delbrueckii DSM 20074 and L. plantarum MB 456 were able to inhibit all coliforms strains (halo-forming method), also in liquid co-cultures, thus demonstrating an antagonistic activity. This study shows that two out of 27 strains of Lactobacillus examined possess an antimicrobial effect against six species of gas-forming coliforms isolated from colicky infants. Our findings may stimulate new researches to identify which Lactobacillus strains can improve colicky symptoms by acting on coliforms gut colonization.

Manipulation of the microbiota of mass-reared Mediterranean fruit flies Ceratitis capitata (Diptera: Tephritidae) improves sterile male sexual performance.

PubMed

Ben Ami, Eyal; Yuval, Boaz; Jurkevitch, Edouard

2010-01-01

The sterile insect technique (SIT) is a method of biological control whereby millions of factory reared sterile male insects are released into the field. This technique is commonly used to combat the Mediterranean fruit fly (Ceratitis capitata, Diptera: Tephritidae). Sterile medfly males are less competent in attracting and mating with wild females, a property commonly linked to the irradiation process responsible for the sterilization. As bacteria are important partners in the fly's life cycle, we used molecular analytical methods to study the community structure of the gut microbiota in irradiated male medflies. We find that the sterilizing irradiation procedure affects the gut bacterial community structure of the Mediterranean fruit fly. Although the Enterobacteriaceae family remains the dominant bacterial group present in the gut, the levels of Klebsiella species decreases significantly in the days after sterilization. In addition, we detected substantial differences in some bacterial species between the mass rearing strain Vienna 8 and the wild strain. Most notable among these are the increased levels of the potentially pathogenic species Pseudomonas in the industrial strain. Testing the hypothesis that regenerating the original microbiota community could result in enhanced competitiveness of the sterile flies, we found that the addition of the bacterial species Klebsiella oxytoca to the postirradiation diet enables colonization of these bacteria in the gut while resulting in decreased levels of the Pseudomonas sp. Feeding on diets containing bacteria significantly improved sterile male performance in copulatory tests. Further studies will determine the feasibility of bacterial amelioration in SIT operations.

Phenotypic and Molecular Characterization of Antimicrobial Resistance in Klebsiella spp. Isolates from Companion Animals in Japan: Clonal Dissemination of Multidrug-Resistant Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae

PubMed Central

Harada, Kazuki; Shimizu, Takae; Mukai, Yujiro; Kuwajima, Ken; Sato, Tomomi; Usui, Masaru; Tamura, Yutaka; Kimura, Yui; Miyamoto, Tadashi; Tsuyuki, Yuzo; Ohki, Asami; Kataoka, Yasushi

2016-01-01

The emergence of antimicrobial resistance in Klebsiella spp., including resistance to extended-spectrum cephalosporins (ESC) and fluoroquinolones, is of great concern in both human and veterinary medicine. In this study, we investigated the prevalence of antimicrobial resistance in a total of 103 Klebsiella spp. isolates, consisting of Klebsiella pneumoniae complex (KP, n = 89) and K. oxytoca (KO, n = 14) from clinical specimens of dogs and cats in Japan. Furthermore, we characterized the resistance mechanisms, including extended-spectrum β-lactamase (ESBL), plasmid-mediated AmpC β-lactamase (PABL), and plasmid-mediated quinolone resistance (PMQR); and assessed genetic relatedness of ESC-resistant Klebsiella spp. strains by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Antimicrobial susceptibility testing demonstrated that resistance rates to ampicillin, cephalothin, enrofloxacin, ciprofloxacin, trimethoprim/sulfamethoxazole, cefotaxime, gentamicin, tetracycline, chloramphenicol, amoxicillin-clavulanic acid, and cefmetazole were 98.1, 37.9, 37.9, 35.9, 35.0, 34.0, 31.1, 30.1, 28.2, 14.6, and 6.8%, respectively. Phenotypic testing detected ESBLs and/or AmpC β-lactamases in 31 of 89 (34.8%) KP isolates, but not in KO isolates. Resistances to 5 of the 12 antimicrobials tested, as well as the three PMQRs [qnrB, qnrS, and aac(6′)-Ib-cr], were detected significantly more frequently in ESBL-producing KP, than in non-ESBL-producing KP and KO. The most frequent ESBL was CTX-M-15 (n = 13), followed by CTX-M-14 (n = 7), CTX-M-55 (n = 6), SHV-2 (n = 5), CTX-M-2 (n = 2), and CTX-M-3 (n = 2). Based on the rpoB phylogeny, all ESBL-producing strains were identified as K. pneumoniae, except for one CTX-M-14-producing strain, which was identified as K. quasipneumoniae. All of AmpC β-lactamase positive isolates (n = 6) harbored DHA-1, one of the PABLs. Based on MLST and PFGE analysis, ST15 KP clones producing CTX-M-2, CTX-M-15, CTX-M-55, and/or SHV-2, as well as KP clones of ST1844-CTX-M-55, ST655-CTX-M-14, and ST307-CTX-M-15, were detected in one or several hospitals. Surprisingly, specific clones were detected in different patients at an interval of many months. These results suggest that multidrug-resistant ESBL-producing KP were clonally disseminated among companion animals via not only direct but also indirect transmission. This is the first report on large-scale monitoring of antimicrobial-resistant Klebsiella spp. isolates from companion animals in Japan. PMID:27446056

Arsenic-resistant and plant growth-promoting Firmicutes and γ-Proteobacteria species from industrially polluted irrigation water and corresponding cropland.

PubMed

Qamar, N; Rehman, Y; Hasnain, S

2017-09-01

The aim of the study was to explore irrigation water polluted with industrial waste and corresponding cropland to screen bacteria for As detoxification and plant growth promotion. Plant growth-promoting (PGP) As-resistant cropland bacteria were isolated from contaminated irrigation water and corresponding agricultural soil. Phylogenetic analysis revealed that the isolates belonged to two distinct bacterial lineages; Firmicutes and γ-Proteobacteria. Maximum As(V) resistance was exhibited by Klebsiella pneumoniae T22 and Klebsiella oxytoca N53 (550 mmol l -1 ), whereas maximum resistance against As(III) was exhibited by K. oxytoca N53 (200 mmol l -1 ). Maximum As(V) reduction was shown by K. pneumoniae T22 (6·7 mmol l -1 ), whereas maximum As(III) oxidation was exhibited by Bacillus subtilis T23 (4·8 mmol l -1 ). As resistance genes arsB and ACR3 were detected in many of the isolates through polymerase chain reaction. Many of these isolates exhibited PGP traits such as hydrogen cyanide and auxin production as well as phosphate solubilization. The bacterial strains were able to enhance Triticum aestivum growth both in the absence and presence of As, and statistically significant increase in shoot and root lengths was observed especially in case of Acinetobacter lwoffii T24 and Citrobacter freundii N52-treated plants. Cropland bacteria have the ability to support plant growth. Bacteria of croplands irrigated with industrially polluted water develop resistance against toxicants. These bacteria are helpful for the plant growth in such contaminated lands. The bacteria capable of both As detoxification and plant growth promotion, such as A. lwoffii T24 and C. freundii N52, are ideal for remediation and reclamation of polluted lands for agriculture purposes. © 2017 The Society for Applied Microbiology.

Enterotoxicity of a nonribosomal peptide causes antibiotic-associated colitis.

PubMed

Schneditz, Georg; Rentner, Jana; Roier, Sandro; Pletz, Jakob; Herzog, Kathrin A T; Bücker, Roland; Troeger, Hanno; Schild, Stefan; Weber, Hansjörg; Breinbauer, Rolf; Gorkiewicz, Gregor; Högenauer, Christoph; Zechner, Ellen L

2014-09-09

Antibiotic therapy disrupts the human intestinal microbiota. In some patients rapid overgrowth of the enteric bacterium Klebsiella oxytoca results in antibiotic-associated hemorrhagic colitis (AAHC). We isolated and identified a toxin produced by K. oxytoca as the pyrrolobenzodiazepine tilivalline and demonstrated its causative action in the pathogenesis of colitis in an animal model. Tilivalline induced apoptosis in cultured human cells in vitro and disrupted epithelial barrier function, consistent with the mucosal damage associated with colitis observed in human AAHC and the corresponding animal model. Our findings reveal the presence of pyrrolobenzodiazepines in the intestinal microbiota and provide a mechanism for colitis caused by a resident pathobiont. The data link pyrrolobenzodiazepines to human disease and identify tilivalline as a target for diagnosis and neutralizing strategies in prevention and treatment of colitis.

A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

PubMed Central

Van der Heiden, Edwige; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

2013-01-01

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus. PMID:23524682

A pathway closely related to the (D)-tagatose pathway of gram-negative enterobacteria identified in the gram-positive bacterium Bacillus licheniformis.

PubMed

Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M; Galleni, Moreno; Joris, Bernard

2013-06-01

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

Introduction of OXA-48-producing Enterobacteriaceae to Israeli hospitals by medical tourism.

PubMed

Adler, Amos; Shklyar, Maya; Schwaber, Mitchell J; Navon-Venezia, Shiri; Dhaher, Yacoub; Edgar, Rotem; Solter, Ester; Benenson, Shmuel; Masarwa, Samira; Carmeli, Yehuda

2011-12-01

The carbapenemase OXA-48 has been reported from different Mediterranean countries. It is mostly encoded on a single plasmid in various Enterobacteriaceae species. We characterized the epidemiological and molecular features of OXA-48-producing Enterobacteriaceae (OPE) in Israel. Epidemiological investigation was conducted by the National Center for Infection Control. Genotyping was performed using multilocus sequence typing. The bla(OXA-48)-carrying plasmids were investigated using S1 endonuclease and restriction fragment length polymorphism (RFLP). Conjugation efficiency of the bla(OXA-48)-carrying plasmids was studied in a filter mating experiment. Since 2007, four OPE-infected patients were identified, all non-Israeli (two Palestinian, one Jordanian and one Georgian). Three had prior hospitalization; two in Jordan and one in Georgia. The bla(OXA-48) gene was detected in three Escherichia coli strains belonging to different clonal complexes, one Klebsiella oxytoca and one Klebsiella pneumoniae sequence type 101, as previously reported from Tunisia and Spain. In all isolates, the bla(OXA-48) gene was located inside Tn1999.2 and was carried on a 60 kb plasmid with an identical RFLP pattern. The plasmid was able to conjugate from Klebsiella spp. to E. coli, and had a conjugation efficiency up to ~10000 times higher than that of pKpQIL. OPE, introduced mainly by medical tourism, are an emerging threat to patients from affected Mediterranean countries. The bla(OXA-48)-carrying plasmid demonstrated remarkable conjugation efficiency, which is probably important in the success of its dissemination.

Characterization and purification of a bacteriocin from Lactobacillus paracasei subsp. paracasei BMK2005, an intestinal isolate active against multidrug-resistant pathogens.

PubMed

Bendjeddou, Kamel; Fons, Michel; Strocker, Pierre; Sadoun, Djamila

2012-04-01

A strain of Lactobacillus paracasei subsp. paracasei BMK2005 isolated from healthy infant faeces has shown a remarkable antibacterial activity against 32 bacterial pathogenic strains of human clinical isolates. Among them, 13 strains belonging to species of Escherichia coli, Citrobacter freundii, Citrobacter diversus, Klebsiella oxytoca, Enterobacter cloacae and Pseudomonas aeruginosa were resistant to Cefotaxime (CTX) and Ceftazidime (CAZ), and 4 strains of Staphylococcus aureus were resistant to Methicillin (MRSA). This antibacterial activity was attributed to a bacteriocin designated as Paracaseicin A. It was heat-stable up to 120°C for 5 min and active within the pH range of 2-5. Its activity was lost when treated with proteases, which reveals its proteinaceous nature. This bacteriocin was successfully purified only by two steps of reversed phase chromatography. Its molecular mass, determined by mass spectrometry analysis, was 2,462.5 Da. To our knowledge, the present study is the first report on characterization and purification of a bacteriocin, produced by a L. paracasei subsp. paracasei strain exhibiting an antibacterial activity against various multidrug-resistant species of Gram-positive and Gram-negative bacteria, which reveals its potential for use in prevention or treatment of infections caused by multidrug-resistant species especially in cases of antibiotics-associated diarrhea (AAD).

Molecular Characteristics and Antibiotic Resistance Profiles of Klebsiella Isolates in Mthatha, Eastern Cape Province, South Africa.

PubMed

Vasaikar, Sandeep; Obi, Larry; Morobe, Isaac; Bisi-Johnson, Mary

2017-01-01

The increase in the incidence of extended-spectrum β -lactamase- (ESBL-) producing Klebsiella species has become a serious problem worldwide, because of their incrimination in antibiotic resistance. The objective of this study is to investigate the resistance genes responsible for ESBL-producing Klebsiella species and carbapenemase-producing Klebsiella (CRE) isolated in Mthatha and to study their epidemiology. A prospective, descriptive study of 202 nonrepetitive samples from patients was obtained from Nelson Mandela Academic Hospital. The cultured Klebsiella isolates were subjected to antimicrobial susceptibility tests and the polymerase chain reaction of bla CTX-M , bla TEM , bla SHV , bla KPC , and bla NDM genes. Overall K. pneumoniae were the majority with 169 (83.7%) species isolates, followed by K. oxytoca with 29 (14.4%), while K. ozaenae and Raoultella ornithinolytica were 2 (0.9%) each. The prevalence of ESBL production in all Klebsiella species was 117 (57.9%). ESBL-genotypic resistance is driven in Mthatha by bla SHV 121 (77.1%) followed by bla TEM 105 (66.9%) and bla CTX-M at 89 (56.7%). The most common ESBL genotype combination among the Klebsiella was bla TEM + bla SHV + bla CTX-M at 79 (50.3%). There is a steady increase in the rate of ESBL genes in the last five years.

A novel Fe(III) dependent bioflocculant from Klebsiella oxytoca GS-4-08: culture conditions optimization and flocculation mechanism

PubMed Central

Yu, Lei; Tang, Qing-wen; Zhang, Yu-jia; Chen, Rong-ping; Liu, Xin; Qiao, Wei-chuan; Li, Wen-wei; Ruan, Hong-hua; Song, Xin

2016-01-01

In this work, the effect of cultivation factors on the flocculation efficiency (FE) of bioflocculant P-GS408 from Klebsiella oxytoca was optimized by the response surface methodology. The most significant factor, i.e. culture time, was determined by gray relational analysis. A total of 240 mg of purified P-GS408 was prepared from 1 liter of culture solution under the optimal conditions. GC-MS analysis results indicated that the polysaccharide of P-GS408 mainly contains Rhamnose and Galactose, and the existence of abundant hydroxyl, carboxyl and amino groups was evidenced by FTIR and XPS analyses. With the aid of Fe3+, the FE of kaolin solution by P-GS408 could achieve 99.48% in ten minutes. Functional groups of polysaccharide were involved in the first adsorption step and the zeta potential of kaolin solution changed from −39.0 mV to 43.4 mV in the presence of Fe3+ and P-GS408. Three-dimensional excitation-emission (EEM) fluorescence spectra demonstrates that the trivalent Fe3+ and Al3+ can bind efficiently with P-GS408, while those univalent and divalent cations cannot. With the help of SEM images, FTIR, zeta potential and EEM spectra, we proposed the P-GS408 flocculation mechanism, which consists of coordination bond combination, charge neutrality, adsorption and bridging, and net catching. PMID:27713559

A novel Fe(III) dependent bioflocculant from Klebsiella oxytoca GS-4-08: culture conditions optimization and flocculation mechanism.

PubMed

Yu, Lei; Tang, Qing-Wen; Zhang, Yu-Jia; Chen, Rong-Ping; Liu, Xin; Qiao, Wei-Chuan; Li, Wen-Wei; Ruan, Hong-Hua; Song, Xin

2016-10-07

In this work, the effect of cultivation factors on the flocculation efficiency (FE) of bioflocculant P-GS408 from Klebsiella oxytoca was optimized by the response surface methodology. The most significant factor, i.e. culture time, was determined by gray relational analysis. A total of 240 mg of purified P-GS408 was prepared from 1 liter of culture solution under the optimal conditions. GC-MS analysis results indicated that the polysaccharide of P-GS408 mainly contains Rhamnose and Galactose, and the existence of abundant hydroxyl, carboxyl and amino groups was evidenced by FTIR and XPS analyses. With the aid of Fe 3+ , the FE of kaolin solution by P-GS408 could achieve 99.48% in ten minutes. Functional groups of polysaccharide were involved in the first adsorption step and the zeta potential of kaolin solution changed from -39.0 mV to 43.4 mV in the presence of Fe 3+ and P-GS408. Three-dimensional excitation-emission (EEM) fluorescence spectra demonstrates that the trivalent Fe 3+ and Al 3+ can bind efficiently with P-GS408, while those univalent and divalent cations cannot. With the help of SEM images, FTIR, zeta potential and EEM spectra, we proposed the P-GS408 flocculation mechanism, which consists of coordination bond combination, charge neutrality, adsorption and bridging, and net catching.

Chemical composition of essential oil from ripe fruit of Schinus terebinthifolius Raddi and evaluation of its activity against wild strains of hospital origin

PubMed Central

Cole, E.R.; dos Santos, R.B.; Júnior, V. Lacerda; Martins, J.D.L.; Greco, S.J.; Neto, A. Cunha

2014-01-01

The essential oil (EO) composition of ripe fruit of S. terebinthifolius Raddi was analyzed by GC-MS. The oil extraction yielded 6.54 ± 1.06% (w/w). Seventeen compounds were identified, accounting for 91.15% of the total oil, where monoterpenes constituted the main chemical class (85.81%), followed by sesquiterpenes (5.34%). The major monoterpene identified was δ-3-carene (30.37%), followed by limonene (17.44%), α-phellandrene (12.60%) and α-pinene (12.59%). Trans-caryophyllene (1.77%) was the major sesquiterpene identified. The antibacterial activity of the essential oil was evaluated against wild strains of hospital origin (Escherichia coli, Pseudomonas sp., Klebsiella oxytoca, Corynebacterium sp., Staphylococcus aureus, Enterobacter sp., Enterobacter agglomerans, Bacillus sp., Nocardia sp. and Streptococcus group D). The essential oil of the ripe fruit of S. terebinthifolius Raddi has shown to be active against all tested wild strains, with minimum inhibitory concentration ranging from 3.55 μg/mL to 56.86 μg/mL. However, it has revealed some differences in susceptibility: the general, Gram-positive species showed greater sensitivity to the action of EO, which is probably due to the lower structural complexity of their cell walls. PMID:25477913

Chemical composition of essential oil from ripe fruit of Schinus terebinthifolius Raddi and evaluation of its activity against wild strains of hospital origin.

PubMed

Cole, E R; dos Santos, R B; Lacerda Júnior, V; Martins, J D L; Greco, S J; Cunha Neto, A

2014-01-01

The essential oil (EO) composition of ripe fruit of S. terebinthifolius Raddi was analyzed by GC-MS. The oil extraction yielded 6.54 ± 1.06% (w/w). Seventeen compounds were identified, accounting for 91.15% of the total oil, where monoterpenes constituted the main chemical class (85.81%), followed by sesquiterpenes (5.34%). The major monoterpene identified was δ-3-carene (30.37%), followed by limonene (17.44%), α-phellandrene (12.60%) and α-pinene (12.59%). Trans-caryophyllene (1.77%) was the major sesquiterpene identified. The antibacterial activity of the essential oil was evaluated against wild strains of hospital origin (Escherichia coli, Pseudomonas sp., Klebsiella oxytoca, Corynebacterium sp., Staphylococcus aureus, Enterobacter sp., Enterobacter agglomerans, Bacillus sp., Nocardia sp. and Streptococcus group D). The essential oil of the ripe fruit of S. terebinthifolius Raddi has shown to be active against all tested wild strains, with minimum inhibitory concentration ranging from 3.55 μg/mL to 56.86 μg/mL. However, it has revealed some differences in susceptibility: the general, Gram-positive species showed greater sensitivity to the action of EO, which is probably due to the lower structural complexity of their cell walls.

Characterization of CTX-M enzymes, quinolone resistance determinants, and antimicrobial residues from hospital sewage, wastewater treatment plant, and river water.

PubMed

Conte, Danieli; Palmeiro, Jussara Kasuko; da Silva Nogueira, Keite; de Lima, Thiago Marenda Rosa; Cardoso, Marco André; Pontarolo, Roberto; Degaut Pontes, Flávia Lada; Dalla-Costa, Libera Maria

2017-02-01

Multidrug-resistant (MDR) bacteria are widespread in hospitals and have been increasingly isolated from aquatic environments. The aim of the present study was to characterize extended-spectrum β-lactamase (ESBL) and quinolone-resistant Enterobacteriaceae from a hospital effluent, sanitary effluent, inflow sewage, aeration tank, and outflow sewage within a wastewater treatment plant (WWTP), as well as river water upstream and downstream (URW and DRW, respectively), of the point where the WWTP treated effluent was discharged. β-lactamase (bla) genes, plasmid-mediated quinolone resistance (PMQR), and quinolone resistance-determining regions (QRDRs) were assessed by amplification and sequencing in 55 ESBL-positive and/or quinolone-resistant isolates. Ciprofloxacin residue was evaluated by high performance liquid chromatography. ESBL-producing isolates were identified in both raw (n=29) and treated (n=26) water; they included Escherichia coli (32), Klebsiella pneumoniae (22) and Klebsiella oxytoca (1). Resistance to both cephalosporins and quinolone was observed in 34.4% of E. coli and 27.3% of K. pneumoniae. Resistance to carbapenems was found in 5.4% of K. pneumoniae and in K. oxytoca. Results indicate the presence of bla CTX-M (51/55, 92.7%) and bla SHV (8/55, 14.5%) ESBLs, and bla GES (2/55, 3.6%) carbapenemase-encoding resistance determinants. Genes conferring quinolone resistance were detected at all sites, except in the inflow sewage and aeration tanks. Quinolone resistance was primarily attributed to amino acid substitutions in the QRDR of GyrA (47%) or to the presence of PMQR (aac-(6')-Ib-cr, oqxAB, qnrS, and/or qnrB; 52.9%) determinants. Ciprofloxacin residue was absent only from URW. Our results have shown strains carrying ESBL genes, PMQR determinants, and mutations in the gyrA QRDR genes mainly in hospital effluent, URW, and DRW samples. Antimicrobial use, and the inefficient removal of MDR bacteria and antibiotic residue during sewage treatment, may contribute to the emergence and spreading of resistance in the environment, making this a natural reservoir. Copyright © 2016 Elsevier Inc. All rights reserved.

Enrichment and identification of cellulolytic bacteria from the gastrointestinal tract of Giant African snail, Achatina fulica.

PubMed

Pawar, Kiran D; Dar, Mudasir A; Rajput, Bharati P; Kulkarni, Girish J

2015-02-01

The cellulolytic bacterial community structure in gastrointestinal (GI) tract of Achatina fulica was studied using culture-independent and -dependent methods by enrichment in carboxymethyl cellulose (CMC). Culture-dependent method indicated that GI tract of snail was dominated by Enterobacteriaceae members. When tested for cellulase activities, all isolates obtained by culture-dependent method showed both or either of CMCase or avicelase activity. Isolate identified as Citrobacter freundii showed highest CMCase and medium avicelase activity. Sequencing of clones from the 16S rRNA gene clone library identified ten operational taxonomic units (OTUs), which were affiliated to Enterobacteriaceae of phylum Gammaproteobacteria. Of these ten OTUs, eight OTUs closely matched with Enterobacter and Klebsiella genera. The most abundant OTU allied to Klebsiella oxytoca accounted for 70 % of the total sequences. The members of Klebsiella and Enterobacter were observed by both methods indicating their dominance among the cellulolytic bacterial community in the GI tract of the snail.

Efficacy of surface disinfectant cleaners against emerging highly resistant gram-negative bacteria

PubMed Central

2014-01-01

Background Worldwide, the emergence of multidrug-resistant gram-negative bacteria is a clinical problem. Surface disinfectant cleaners (SDCs) that are effective against these bacteria are needed for use in high risk areas around patients and on multi-touch surfaces. We determined the efficacy of several SDCs against clinically relevant bacterial species with and without common types of multidrug resistance. Methods Bacteria species used were ATCC strains; clinical isolates classified as antibiotic-susceptible; and multi-resistant clinical isolates from Klebsiella oxytoca, Klebsiella pneumoniae, and Serratia marcescens (all OXA-48 and KPC-2); Acinetobacter baumannii (OXA-23); Pseudomonas aeruginosa (VIM-1); and Achromobacter xylosoxidans (ATCC strain). Experiments were carried out according to EN 13727:2012 in quadruplicate under dirty conditions. The five evaluated SDCs were based on alcohol and an amphoteric substance (AAS), an oxygen-releaser (OR), surface-active substances (SAS), or surface-active-substances plus aldehydes (SASA; two formulations). Bactericidal concentrations of SDCs were determined at two different contact times. Efficacy was defined as a log10 ≥ 5 reduction in bacterial cell count. Results SDCs based on AAS, OR, and SAS were effective against all six species irrespective of the degree of multi-resistance. The SASA formulations were effective against the bacteria irrespective of degree of multi-resistance except for one of the four P. aeruginosa isolates (VIM-1). We found no general correlation between SDC efficacy and degree of antibiotic resistance. Conclusions SDCs were generally effective against gram-negative bacteria with and without multidrug resistance. SDCs are therefore suitable for surface disinfection in the immediate proximity of patients. Single bacterial isolates, however, might have reduced susceptibility to selected biocidal agents. PMID:24885029

Adverse effects of members of the Enterobacteriaceae family on boar sperm quality.

PubMed

Ubeda, Juan Luis; Ausejo, Raquel; Dahmani, Yahya; Falceto, Maria V; Usan, Adan; Malo, Clara; Perez-Martinez, Francisco C

2013-10-01

Semen samples collected in 2012 from 1785 boars belonging to five different breeds were recruited from the quality control laboratory of Magapor SL, Spain. These samples came from 43 boar studs and resulted from diluting the ejaculates in commercial semen extenders. Evaluation of the semen sample characteristics (color, smell, pH, osmolality, concentration, motility of sperm cells, agglutination, acrosome integrity, short hypoosmotic swelling test, and abnormal forms) revealed that they met the international standards. The samples were also tested for the presence of aerobic bacterial contamination. In the present study, 14.73% (n = 263) of the semen samples were contaminated above 3 × 10(2) colony-forming units/mL with at least one type of bacteria. The Enterobacteriaceae family was by far the major contaminant, being present in 40.68% of the contaminated samples (n = 107). Bacterial strains of the Enterobacteriaceae family isolated from boar semen samples were in order of incidence (percentage of the contaminated samples): Serratia marcescens (12.55%), Klebsiella oxytoca (11.79%), Providencia stuartii (9.12%), Morganella morganii (3.80%), Proteus mirabilis (1.90%), and Escherichia coli (1.52%). We have seen that the presence in semen samples of S. marcescens, K. oxytoca, M. morganii, or P. mirabilis, but not P. stuartii or E. coli, was negatively associated with sperm motility (P < 0.05). The mean sperm concentration (P < 0.05), the mean percentage of spermatozoa with curled tails after the short hypoosmotic swelling test (P < 0.01), and the incidence of morphologically normal acrosomes (P < 0.05) were also lower in semen samples infected with M. morganii compared with uninfected ones. Moreover, P. mirabilis was negatively associated with the presence of abnormal forms. Thus, on the basis of the pathological effects that some of these strains may have on boar sperm quality, bacterial contamination should always be examined in semen samples prepared for artificial insemination. Copyright © 2013 Elsevier Inc. All rights reserved.

Refugees and antimicrobial resistance: A systematic review.

PubMed

de Smalen, Allard Willem; Ghorab, Hatem; Abd El Ghany, Moataz; Hill-Cawthorne, Grant A

There is a large increase in the numbers of refugees and asylum seekers worldwide and a lack of data on the carriage of antimicrobial resistance in refugee/asylum seeking groups. This article aims to identify the impact of refugees and asylum seekers on the acquisition and transmission of antimicrobial resistance (AMR) through a literature search. The databases Embase, Medline, Pubmed, and Web of Science Core Collection were utilised and covered all articles before the 1st of October 2016. In total, 577 articles were identified, and studies were eligible if they met the selection criteria, including observational study design, English language, and AMR strains reported in absolute numbers. In total, 17 articles met the criteria, the majority were from the European region. Articles fitting the selection criteria exclusively reported AMR in bacterial species including Mycobacterium tuberculosis, Escherichia coli, Klebsiella pneumonia, K. oxytoca, Shigella spp., Staphylococcus aureus, Enterococcus faecium, and Acinetobacter baumannii. The analyses indicated that a high percentage of AMR strains, have been circulating among refugees and asylum seekers. The displacement of refugees and asylum seekers seem to play a key role in the transmission of AMR. Therefore, improved AMR control measures are essential. A knowledge gap was identified; further research is strongly recommended. Copyright © 2016 Elsevier Ltd. All rights reserved.

Kinetic properties analysis of beta-mannanase from Klebsiella oxytoca KUB-CW2-3 expressed in Escherichia coli.

PubMed

Tuntrakool, Pirudee; Keawsompong, Suttipun

2018-06-01

Endo-1,4-β-mannanase is an enzyme that can catalyze the random hydrolysis of β-1,4-mannosidic linkages in the main chain of mannans, glucomannans and galactomannans and offers many applications in different biotechnology industries. Purification and kinetic properties of the endo-1,4-β-mannanase from recombinant Escherichia coli strain KMAN-3 were examined. Recombinant β-mannanase (KMAN-3) was purified 50.5 fold using Ni-NTA Agarose resin and specific activity of 11900 U/mg protein was obtained. Purified KMAN-3 showed a single band on SDS-PAGE with a molecular weight of 43 kDa. K m and V max values of KMAN-3 on ivory nut mannan, locust bean gum, defatted copra meal and konjac glucomannan were 243, 3.83 × 10 5 37 and 2.13 × 10 6  mg ml -1 and 2940, 61,100, 3930 and 1.56 × 10 10  mg -1 , respectively. Carboxymethyl cellulose was not digested by KMAN-3. Copyright © 2018 Elsevier Inc. All rights reserved.

Simultaneous Decolorization and Biohydrogen Production from Xylose by Klebsiella oxytoca GS-4-08 in the Presence of Azo Dyes with Sulfonate and Carboxyl Groups

PubMed Central

Cao, Ming-yue; Wang, Peng-tao; Wang, Shi; Yue, Ying-rong; Yuan, Wen-duo; Qiao, Wei-chuan; Wang, Fei

2017-01-01

ABSTRACT Biohydrogen production from the pulp and paper effluent containing rich lignocellulosic material could be achieved by the fermentation process. Xylose, an important hemicellulose hydrolysis product, is used less efficiently as a substrate for biohydrogen production. Moreover, azo dyes are usually added to fabricate anticounterfeiting paper, which further increases the complexity of wastewater. This study reports that xylose could serve as the sole carbon source for a pure culture of Klebsiella oxytoca GS-4-08 to achieve simultaneous decolorization and biohydrogen production. With 2 g liter−1 of xylose as the substrate, a maximum xylose utilization rate (URxyl) and a hydrogen molar yield (HMY) of 93.99% and 0.259 mol of H2 mol of xylose−1, respectively, were obtained. Biohydrogen kinetics and electron equivalent (e− equiv) balance calculations indicated that methyl red (MR) penetrates and intracellularly inhibits both the pentose phosphate pathway and pyruvate fermentation pathway, while methyl orange (MO) acted independently of the glycolysis and biohydrogen pathway. The data demonstrate that biohydrogen pathways in the presence of azo dyes with sulfonate and carboxyl groups were different, but the azo dyes could be completely reduced during the biohydrogen production period in the presence of MO or MR. The feasibility of hydrogen production from industrial pulp and paper effluent by the strain if the xylose is sufficient was also proved and was not affected by toxic substances which usually exist in such wastewater, except for chlorophenol. This study offers a promising energy-recycling strategy for treating pulp and paper wastewaters, especially for those containing azo dyes. IMPORTANCE The pulp and paper industry is a major industry in many developing countries, and the global market of pulp and paper wastewater treatment is expected to increase by 60% between 2012 and 2020. Such wastewater contains large amounts of refractory contaminants, such as lignin, whose reclamation is considered economically crucial and environmentally friendly. Furthermore, azo dyes are usually added in order to fabricate anticounterfeiting paper, which further increases the complexity of the pulp and paper wastewater. This work may offer a better understanding of biohydrogen production from xylose in the presence of azo dyes and provide a promising energy-recycling method for treating pulp and paper wastewater, especially for those containing azo dyes. PMID:28283518

Epidemiological typing of Enterobacter aerogenes.

PubMed Central

Gaston, M A; Strickland, M A; Ayling-Smith, B A; Pitt, T L

1989-01-01

The applicability of Enterobacter cloacae and Klebsiella typing reagents for classifying clinical strains of Enterobacter aerogenes was evaluated. Of 75 strains, none were agglutinated by E. cloacae O antisera or were sensitive to E. cloacae bacteriophages. In contrast, 70 strains reacted with Klebsiella capsular antisera. Two-thirds of the strains were lysed by Klebsiella typing phages. A set of five E. aerogenes bacteriocin producers classified 92% of strains into 15 sensitivity types. In conclusion, E. aerogenes may be typed with Klebsiella reagents, and the simple bacteriocin test provides further discrimination between strains. The limited number of capsular antigens in the species and their apparent similarity to Klebsiella capsular antigens warrant further investigation. PMID:2715326

Co-relation of estrous cycle phases with uterine bacterial and fungal flora in non-pregnant female laboratory rabbits

PubMed Central

Mogheiseh, A.; Derakhshandeh, A.; Batebi, E.; Golestani, N.; Moshiri, A.

2017-01-01

This study was designed to investigate the relationship between the estrous cycle phases with uterine bacterial and fungal flora in non-pregnant female rabbits. Thirty laboratory mature multiparous rabbits were used for this purpose. Samples from uterine lavage for culture of bacteria and fungi were collected at different stages of estrous cycle (based on vaginal cytology), and histopathological observations were evaluated based on the scoring system used for defining the infection of the uterus. Various types of bacteria and fungi were isolated from rabbits at all stages of estrous cycle. The widest variety of bacteria and fungi was isolated at Di-estrous stage and the lowest variety was detected at estrous stage. Klebsiella oxytoca as well as yeast have been isolated at all stages of estrous cycle. This study showed that infection with K. oxytoca and yeast had no relationship with different stages of estrous cycle but other bacteria and fungus were associated with one or more stages of the estrous cycle in rabbits. PMID:28775754

Frequency of Extended-Spectrum Beta-lactamases (ESBLs) in strains of Klebsiella and E. coli isolated from patients hospitalized in Yazd.

PubMed

Zandi, Hengameh; Tabatabaei, Seyed Mostafa; Ehsani, Fatemeh; Zarch, Mojtaba Babaei; Doosthosseini, Samira

2017-02-01

Frequency of extended-spectrum beta-lactamases (ESBLs) and its variants may vary in different geographical areas, as reports indicate their spread in some certain communities. The aim of this study was to determine the frequency of ESBLs in strains of Klebsiella and E. coli , isolated from patients hospitalized in teaching hospitals of Yazd. This cross-sectional study was carried out on samples including E. coli and Klebsiella strains collected from laboratories of Shahid Sadoughi and Shahid Rahnemoun hospitals in Yazd, Iran in the period of 2011-2012. The colonies which were positive in lactose Eosin methylene-blue (EMB) medium were identified by biochemical methods, and 270 strains of Klebsiella and E. coli were isolated. Collected data and information were analyzed using Fisher's exact test and descriptive statistics such as mean in SPSS software, version 15, at a significant level of 0.05. In this study, 270 samples were examined, including 152 samples of E. coli (56.3%) and 118 samples of Klebsiella pneumonia (43.7%). Among the 152 samples of E. coli , 45 strains (30%) were producers of ESBLs. In addition, among the 118 samples of Klebsiella pneumonia , 44 strains (37.3%) were producers of ESBLs. E. coli strains showed the most resistance to Cefotaxime (100%), Ceftazidime (97.7%), and Cefepime (75.5%) respectively and Klebsiella strains showed the most resistance to Cefotaxime (100%), Ceftazidime (100%) and Cefepime (79.5%), respectively. Frequency of ESBLs in Klebsiella strains was higher than E. coli strains. No significant relationship was found between frequency of ESBLs and age or gender. In addition, E. coli strains showed the highest sensitivity to Imipenem, Amoxicillin/clavulanate, and Ciprofloxacin, while the highest antibiotic sensitivity of Klebsiella strains was shown to be to Piperacillin, Imipenem, and Amoxicillin/clavulanate.

In vitro assessment of Pediococcus acidilactici Kp10 for its potential use in the food industry.

PubMed

Abbasiliasi, Sahar; Tan, Joo Shun; Bashokouh, Fatemeh; Ibrahim, Tengku Azmi Tengku; Mustafa, Shuhaimi; Vakhshiteh, Faezeh; Sivasamboo, Subhashini; Ariff, Arbakariya B

2017-05-23

Selection of a microbial strain for the incorporation into food products requires in vitro and in vivo evaluations. A bacteriocin-producing lactic acid bacterium (LAB), Pediococcus acidilactici Kp10, isolated from a traditional dried curd was assessed in vitro for its beneficial properties as a potential probiotic and starter culture. The inhibitory spectra of the bacterial strain against different gram-positive and gram-negative bacteria, its cell surface hydrophobicity and resistance to phenol, its haemolytic, amylolytic and proteolytic activities, ability to produce acid and coagulate milk together with its enzymatic characteristics and adhesion property were all evaluated in vitro. P. acidilactici Kp10 was moderately tolerant to phenol and adhere to mammalian epithelial cells (Vero cells and ileal mucosal epithelium). The bacterium also exhibited antimicrobial activity against several gram-positive and gram-negative food-spoilage and food-borne pathogens such as Listeria monocytgenes ATCC 15313, Salmonella enterica ATCC 13311, Shigella sonnei ATCC 9290, Klebsiella oxytoca ATCC 13182, Enterobacter cloaca ATCC 35030 and Streptococcus pyogenes ATCC 12378. The absence of haemolytic activity and proteinase (trypsin) and the presence of a strong peptidase (leucine-arylamidase) and esterase-lipase (C4 and C8) were observed in this LAB strain. P. acidilactici Kp10 also produced acid, coagulated milk and has demonstrated proteolytic and amylolactic activities. The properties exhibited by P. acidilactici Kp10 suggested its potential application as probiotic and starter culture in the food industry.

Identification and characterization of plasmid-mediated quinolone resistance determinants in Enterobacteriaceae isolated from healthy poultry in Brazil.

PubMed

Ferreira, Joseane Cristina; Penha Filho, Rafael Antonio Casarin; Kuaye, Ana Paula Yorika; Andrade, Leonardo Neves; Berchieri Junior, Angelo; Darini, Ana Lúcia da Costa

2018-06-01

The expression of plasmid-mediated quinolone resistance (PMQR) genes confers low-level quinolone and fluoroquinolones resistance alone. However, the association to chromosomal resistance mechanisms determines an expressively higher resistance in Enterobacteriaceae. These mechanisms are horizontally disseminated within plasmids and have contributed to the emergence of bacteria with reduced susceptibility or resistant to therapies worldwide. The epidemiological characterization of PMQR dissemination is highly relevant in the scientific and medical context, to investigate the dissemination within enterobacteria, from different populations, including humans and food-producing animals. In the present study, 200 Enterobacteriaceae isolates were harvested from poultry with cloacal swabs and identified as Escherichia coli (90.5%), Escherichia fergusonii (5.5%), Klebsiella oxytoca (2.5%) and Klebsiella pneumoniae (1.5%). Among isolates evaluated, 46 (23%) harboured PMQR genes including qnrB (43/200), qnrS (2/200) and aac(6')-Ib-cr (1/200). All isolates carrying PMQR genes showed multidrug-resistance phenotype. The 36 E. coli isolates showed 18 different PFGE types. All E. fergusonii isolates showed the same PFGE type. The two Klebsiella oxytoca belonged to two different PFGE types. The phylogenetic groups A, B1, and D were found among the E. coli harboring PMQR genes. Based on the phylogenetic analysis and PFGE, the population structure of E. coli isolates was diverse, even within the same farm. All isolates carrying qnrB and qnrS genes also harboured ColE-like plasmids. The Southern blot hybridization using the S1-PFGE revealed that the qnrB genes were located on low molecular weight plasmids, smaller than 10Kb. Resistance plasmids were sequenced and showed 100% identity with plasmid pPAB19-3. The association of PMQR genes with mobile genetic elements, such as transferable plasmids, favours the selection and dissemination of (fluoro) quinolones resistant bacteria among food-producing animals, and may play an important role in the current increased prevalence of resistant bacteria in different environments reported worldwide. Copyright © 2018. Published by Elsevier B.V.

Characterization of Klebsiella isolates by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and determination of antimicrobial resistance with VITEK 2 advanced expert system (AES).

PubMed

Karagöz, Alper; Acar, Sümeyra; Körkoca, Hanifi

2015-01-01

The purpose of the study was to evaluate the performance of the VITEK mass spectrometry (MS) (bioMérieux, France) system for the identification of Klebsiella spp. isolated from different sources. Moreover, while assessing the ability of the VITEK 2 automated expert system (AES) to recognize antimicrobial resistance patterns, the researchers have extended the study to compare VITEK 2 with the routine antimicrobial susceptibility testing method. This study tested 51 Klebsiella spp. isolates that were isolated from environmental examples and clinical examples. Results of conventional methods and the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS were compared. Then, any differing results were compared against a reference 16S rRNA gene sequence, and when indicated, a recA sequencing analysis was done. VITEK MS correctly identified 100% of the Klebsiella spp. isolates. There were two K. oxytoca isolates incorrectly identified to the species level with conventional methods according to the 16S rRNA gene sequencing analysis. In addition, a VITEK 2 AST-N261 card was used for the detection of extended spectrum beta-lactamases (ESBL). Using the VITEK 2 AES, ESBL positivity was found at the rate of 16.3% whereas this rate was 4.08% using the disk diffusion method. MALDI-TOF MS is a rapid and accurate method for the identification of Klebsiella spp. Moreover, the bioMérieux AES provides a useful laboratory tool for the interpretation of susceptibility results.

The recognition and modification sites for the bacterial type I restriction systems KpnAI, StySEAI, StySENI and StySGI

PubMed Central

Kasarjian, Julie K. A.; Hidaka, Masumi; Horiuchi, Takashi; Iida, Masatake; Ryu, Junichi

2004-01-01

Using an in vivo plasmid transformation method, we have determined the DNA sequences recognized by the KpnAI, StySEAI, StySENI and StySGI R-M systems from Klebsiella oxytoca strain M5a1, Salmonella eastbourne, Salmonella enteritidis and Salmonella gelsenkirchen, respectively. These type I restriction-modification systems were originally identified using traditional phage assay, and described here is the plasmid transformation test and computer program used to determine their DNA recognition sequences. For this test, we constructed two sets of plasmids, pL and pE, that contain phage lambda and Escherichia coli K-12 chromosomal DNA fragments, respectively. Further, using the methylation sensitivities of various known type II restriction enzymes, we identified the target adenines for methylation (listed in bold italics below as A or T in case of the complementary strand). The recognition sequence and methylation sites are GAA(6N)TGCC (KpnAI), ACA(6N)TYCA (StySEAI), CGA(6N)TACC (StySENI) and TAAC(7N)RTCG (StySGI). These DNA recognition sequences all have a typical type I bipartite pattern and represent three novel specificities and one isoschizomer (StySENI). For confirmation, oligonucleotides containing each of the predicted sequences were synthesized, cloned into plasmid pMECA and transformed into each strain, resulting in a large reduction in efficiency of transformation (EOT). PMID:15199175

Prevalence and spread of pseudomonas aeruginosa and Klebsiella pneumoniae strains in patients with hematological malignancies.

PubMed

Kolar, Milan; Sauer, Pavel; Faber, Edgar; Kohoutova, Jarmila; Stosová, Tatana; Sedlackova, Michaela; Chroma, Magdalena; Koukalova, Dagmar; Indrak, Karel

2009-01-01

The aim of the study was to determine the prevalence of Pseudomonas aeruginosa and Klebsiella pneumoniae strains in patients with acute leukemias, to assess their clinical significance, and to define the sources and ways of their spread using genetic analysis. Thirty-four patients were investigated during the observed period. Twenty-one strains of Pseudomonas aeruginosa and 35 strains of Klebsiella pneumoniae were isolated from patient samples. In the case of Pseudomonas aeruginosa, 47.6% of strains were identified as pathogens and caused infection. By contrast, only 4 isolates (11.4%) of Klebsiella pneumoniae could be regarded as etiological agents of bacterial infection. Based on the obtained results, Klebsiella pneumoniae strains are assumed to be of mostly endogenous origin. In the case of Pseudomonas aeruginosa strains, the proportion of identical strains detected in various patients was higher and exogenous sources were more significant. In addition, our results confirmed the ability of Pseudomonas aeruginosa strains to survive on a particular site in the hospital for a longer time.

Leaching and microbial treatment of a soil contaminated by sulphide ore ashes and aromatic hydrocarbons.

PubMed

D'Annibale, Alessandro; Leonardi, Vanessa; Federici, Ermanno; Baldi, Franco; Zecchini, Fulvio; Petruccioli, Maurizio

2007-04-01

Contaminated soil from a historical industrial site and containing sulfide ore ashes and aromatic hydrocarbons underwent sequential leaching by 0.5 M citrate and microbial treatments. Heavy metals leaching was with the following efficiency scale: Cu (58.7%) > Pb (55.1%) > Zn (44.5%) > Cd (42.9%) > Cr (26.4%) > Ni (17.7%) > Co (14.0%) > As (12.4%) > Fe (5.3%) > Hg (1.1%) and was accompanied by concomitant removal of organic contaminants (about 13%). Leached metals were concentrated into an iron gel, produced during ferric citrate fermentation by the metal-resistant strain BAS-10 of Klebsiella oxytoca. Concomitantly, the acidic leached soil was bioaugmented with Allescheriella sp. DABAC 1, Stachybotrys sp. DABAC 3, Phlebia sp. DABAC 9, Pleurotus pulmonarius CBS 664.97, and Botryosphaeria rhodina DABAC P82. B. rhodina was most effective, leading to a significant depletion of the most abundant contaminants, including 7-H-benz[DE]anthracene-7-one, 9,10-anthracene dione and dichloroaniline isomers, and to a marked detoxification as assessed by the mortality test with the Collembola Folsomia candida Willem. The overall degradation activities of B. rhodina and P. pulmonarius appeared to be significantly enhanced by the preliminary metal removal.

Interpretive criteria of antimicrobial disk susceptibility tests with flomoxef.

PubMed

Grimm, H

1991-01-01

320 recently isolated pathogens, 20 strains from each of 16 species, were investigated using Mueller-Hinton agar and DIN as well as NCCLS standards. The geometric mean of the agar dilution MICs of flomoxef were 0.44 mg/l for Staphylococcus aureus, 0.05 mg/l (Klebsiella oxytoca) to 12.6 mg/l (Enterobacter spp.) for enterobacteriaceae, 33.1 mg/l for Acinetobacter anitratus, 64 mg/l for Enterococcus faecalis, and more than 256 mg/l for Pseudomonas aeruginosa. For disk susceptibility testing of flomoxef a 30 micrograms disk loading and the following interpretation of inhibition zones using the DIN method were recommended: resistant-up to 22 mm (corresponding to MICs of 8 mg/l or more), moderately susceptible-23 to 29 mm (corresponding to MICs from 1 to 4 mg/l), and susceptible-30 mm or more (corresponding to MICs of 0.5 mg/l or less). The respective values for the NCCLS method using the American high MIC breakpoints are: resistant--up to 14 mm (corresponding to MICs of 32 mg/l or more), moderately susceptible--15 to 17 mm (corresponding to MICs of 16 mg/l), and susceptible--18 mm or more (corresponding to MICs of 8 mg/l or less).

Cloning and sequence of the gene encoding a cefotaxime-hydrolyzing class A beta-lactamase isolated from Escherichia coli.

PubMed Central

Ishii, Y; Ohno, A; Taguchi, H; Imajo, S; Ishiguro, M; Matsuzawa, H

1995-01-01

Escherichia coli TUH12191, which is resistant to piperacillin, cefazolin, cefotiam, ceftizoxime, cefuzonam, and aztreonam but is susceptible to cefoxitin, latamoxef, flomoxef, and imipenem, was isolated from the urine of a patient treated with beta-lactam antibiotics. The beta-lactamase (Toho-1) purified from the bacteria had a pI of 7.8, had a molecular weight of about 29,000, and hydrolyzed beta-lactam antibiotics such as penicillin G, ampicillin, oxacillin, carbenicillin, piperacillin, cephalothin, cefoxitin, cefotaxime, ceftazidime, and aztreonam. Toho-1 was markedly inhibited by beta-lactamase inhibitors such as clavulanic acid and tazobactam. Resistance to beta-lactams, streptomycin, spectinomycin, sulfamethoxazole, and trimethoprim was transferred by conjugational transfer from E. coli TUH12191 to E. coli ML4903, and the transferred plasmid was about 58 kbp, belonging to incompatibility group M. The cefotaxime resistance gene for Toho-1 was subcloned from the 58-kbp plasmid by transformation of E. coli MV1184. The sequence of the gene for Toho-1 was determined, and the open reading frame of the gene consisted of 873 or 876 bases (initial sequence, ATGATG). The nucleotide sequence of the gene (DDBJ accession number D37830) was found to be about 73% homologous to the sequence of the gene encoding a class A beta-lactamase produced by Klebsiella oxytoca E23004. According to the amino acid sequence deduced from the DNA sequence, the precursor consisted of 290 or 291 amino acid residues, which contained amino acid motifs common to class A beta-lactamases (70SXXK, 130SDN, and 234KTG). Toho-1 was about 83% homologous to the beta-lactamase mediated by the chromosome of K. oxytoca D488 and the beta-lactamase mediated by the plasmid of E. coli MEN-1. Therefore, the newly isolated beta-lactamase Toho-1 produced by E. coli TUH12191 is similar to beta-lactamases produced by K. oxytoca D488, K. oxytoca E23004, and E. coli MEN-1 rather than to mutants of TEM or SHV enzymes. Toho-1 has shown the highest degree of similarity to K. oxytoca class A beta-lactamase. Detailed comparison of Toho-1 with other beta-lactamases implied that replacement of Asn-276 by Arg with the concomitant substitution of Thr for Arg-244 is an important mutation in the extension of the substrate specificity. PMID:8619581

Addition of genes for cellobiase and pectinolytic activity in Escherichia coli for fuel ethanol production from pectin-rich lignocellulosic biomass.

PubMed

Edwards, Meredith C; Henriksen, Emily Decrescenzo; Yomano, Lorraine P; Gardner, Brian C; Sharma, Lekh N; Ingram, Lonnie O; Doran Peterson, Joy

2011-08-01

Ethanologenic Escherichia coli strain KO11 was sequentially engineered to contain the Klebsiella oxytoca cellobiose phosphotransferase genes (casAB) as well as a pectate lyase (pelE) from Erwinia chrysanthemi, yielding strains LY40A (casAB) and JP07 (casAB pelE), respectively. To obtain an effective secretion of PelE, the Sec-dependent pathway out genes from E. chrysanthemi were provided on a cosmid to strain JP07 to construct strain JP07C. Finally, oligogalacturonide lyase (ogl) from E. chrysanthemi was added to produce strain JP08C. E. coli strains LY40A, JP07, JP07C, and JP08C possessed significant cellobiase activity in cell lysates, while only strains JP07C and JP08C demonstrated extracellular pectate lyase activity. Fermentations conducted by using a mixture of pure sugars representative of the composition of sugar beet pulp (SBP) showed that strains LY40A, JP07, JP07C, and JP08C were able to ferment cellobiose, resulting in increased ethanol production from 15 to 45% in comparison to that of KO11. Fermentations with SBP at very low fungal enzyme loads during saccharification revealed significantly higher levels of ethanol production for LY40A, JP07C, and JP08C than for KO11. JP07C ethanol yields were not considerably higher than those of LY40A; however, oligogalacturonide polymerization studies showed an increased breakdown of biomass to small-chain (degree of polymerization, ≤6) oligogalacturonides. JP08C achieved a further breakdown of polygalacturonate to monomeric sugars, resulting in a 164% increase in ethanol yields compared to those of KO11. The addition of commercial pectin methylesterase (PME) further increased JP08C ethanol production compared to that of LY40A by demethylating the pectin for enzymatic attack by pectin-degrading enzymes.

Addition of Genes for Cellobiase and Pectinolytic Activity in Escherichia coli for Fuel Ethanol Production from Pectin-Rich Lignocellulosic Biomass▿

PubMed Central

Edwards, Meredith C.; Henriksen, Emily DeCrescenzo; Yomano, Lorraine P.; Gardner, Brian C.; Sharma, Lekh N.; Ingram, Lonnie O.; Doran Peterson, Joy

2011-01-01

Ethanologenic Escherichia coli strain KO11 was sequentially engineered to contain the Klebsiella oxytoca cellobiose phosphotransferase genes (casAB) as well as a pectate lyase (pelE) from Erwinia chrysanthemi, yielding strains LY40A (casAB) and JP07 (casAB pelE), respectively. To obtain an effective secretion of PelE, the Sec-dependent pathway out genes from E. chrysanthemi were provided on a cosmid to strain JP07 to construct strain JP07C. Finally, oligogalacturonide lyase (ogl) from E. chrysanthemi was added to produce strain JP08C. E. coli strains LY40A, JP07, JP07C, and JP08C possessed significant cellobiase activity in cell lysates, while only strains JP07C and JP08C demonstrated extracellular pectate lyase activity. Fermentations conducted by using a mixture of pure sugars representative of the composition of sugar beet pulp (SBP) showed that strains LY40A, JP07, JP07C, and JP08C were able to ferment cellobiose, resulting in increased ethanol production from 15 to 45% in comparison to that of KO11. Fermentations with SBP at very low fungal enzyme loads during saccharification revealed significantly higher levels of ethanol production for LY40A, JP07C, and JP08C than for KO11. JP07C ethanol yields were not considerably higher than those of LY40A; however, oligogalacturonide polymerization studies showed an increased breakdown of biomass to small-chain (degree of polymerization, ≤6) oligogalacturonides. JP08C achieved a further breakdown of polygalacturonate to monomeric sugars, resulting in a 164% increase in ethanol yields compared to those of KO11. The addition of commercial pectin methylesterase (PME) further increased JP08C ethanol production compared to that of LY40A by demethylating the pectin for enzymatic attack by pectin-degrading enzymes. PMID:21666025

Vector potential of hospital houseflies with special reference to Klebsiella species.

PubMed Central

Fotedar, R.; Banerjee, U.; Samantray, J. C.; Shriniwas

1992-01-01

The vector potential of houseflies (Musca domestica) for Klebsiella spp. was investigated. Klebsiella spp. (mostly Klebsiella pneumoniae) were isolated from 36.7% of hospital flies and 28.1% of infected wounds of patients. Antibiograms of Klebsiella spp. showed that 82.0% of isolates from hospital flies and 96.3% from infected wounds were resistant to four or more commonly used antimicrobials. In contrast, from the control group, only 8.7% klebsiella isolates showed similar antimicrobial resistance pattern (P less than 0.001). Similar strains of Klebsiella spp. were encountered among patients and hospital houseflies. The results indicate that flies in the hospital environs are potential vectors of hospital resistant strains of Klebsiella spp. PMID:1499668

Klebsiella pneumoniae inoculants for enhancing plant growth

DOEpatents

Triplett, Eric W [Middleton, WI; Kaeppler, Shawn M [Oregon, WI; Chelius, Marisa K [Greeley, CO

2008-07-01

A biological inoculant for enhancing the growth of plants is disclosed. The inoculant includes the bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101, Pantoea agglomerans P102, Klebsiella pneumoniae 342, Klebsiella pneumoniae zmvsy, Herbaspirillum seropedicae Z152, Gluconacetobacter diazotrophicus PA15, with or without a carrier. The inoculant also includes strains of the bacterium Pantoea agglomerans and K. pneumoniae which are able to enhance the growth of cereal grasses. Also disclosed are the novel bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101 and P102, and Klebsiella pneumoniae 342 and zmvsy.

Whole-Genome Sequencing of a Human Clinical Isolate of the Novel Species Klebsiella quasivariicola sp. nov.

PubMed Central

Linson, Sarah E.; Ojeda Saavedra, Matthew; Cantu, Concepcion; Davis, James J.; Brettin, Thomas; Olsen, Randall J.

2017-01-01

ABSTRACT In a study of 1,777 Klebsiella strains, we discovered KPN1705, which was distinct from all recognized Klebsiella spp. We closed the genome of strain KPN1705 using a hybrid of Illumina short-read and Oxford Nanopore long-read technologies. For this novel species, we propose the name Klebsiella quasivariicola sp. nov. PMID:29051239

[Molecular characterization of pathogenic bacteria of the respiratory tract in peruvian patients with cystic fibrosis].

PubMed

Aquino, Ruth; Gonzáles, Emely; Samaniego, Sol; Rivera, Juan; Cedeño, Virna; Urbina, Yrene; Diringer, Benoit

2017-01-01

To molecularly characterize the pathogenic bacteria of the respiratory tract isolated from patients with cystic fibrosis (CF) in Peru. Bacterial communities cultured from sputum samples of pediatric and adult patients with CF admitted to the Edgardo Rebagliati Martins National Hospital and the National Institute of Child Health were characterized. Standard microbiological techniques were used for bacterial culture, and gene sequencing of 16S rRNA and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and tandem MALDI-TOF mass spectrometry (MALDI TOF/TOF) were used for molecular characterization. Seventeen bacterial strains were characterized by 16S rRNA sequencing, and the identified pathogenic bacteria were Pseudomonas aeruginosa (31.5%), Staphylococcus aureus (12.6%), Pseudomonas spp. (11.8%), and Klebsiella oxytoca (3.1%). MALDI-TOF analysis generated a series of spectra representative of each isolated bacterial species, whereas MALDI TOF/TOF analysis identified the peptides and proteins of the most common strains and provided data on pathogenicity and sensitivity to antibiotics. The primary pathogenic microorganisms found in the respiratory tract of patients with CF in Peru were the same as those found in other countries. This study is the first to perform 16S rRNA sequencing as well as MALDI-TOF and MALDI-TOF/TOF analysis of the bacterial pathogens circulating in Peru. The inclusion of proteomic analysis further allowed for the identification of native microorganisms involved in CF.

Prevalence and risk factors of infections caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae.

PubMed

Nakai, Hazuki; Hagihara, Mao; Kato, Hideo; Hirai, Jun; Nishiyama, Naoya; Koizumi, Yusuke; Sakanashi, Daisuke; Suematsu, Hiroyuki; Yamagishi, Yuka; Mikamo, Hiroshige

2016-05-01

To study the clinical characteristics and associated risk factors of infections caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. A case-control study at a large university hospital in Japan, comparing patients who were infected or colonized with ESBL-producing Enterobacteriaceae (n = 212) and non-ESBL-producing Enterobacteriaceae (n = 2089) in 2010-2013. Data were collected from medical charts, retrospectively. Multivariate logistic regression analysis was used to explore risk factors of ESBL-producing Enterobacteriaceae (Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis) infection or colonization for each pathogen, respectively. ESBL-producing Enterobacteriaceae [E. coli (n = 113), K. oxytoca (n = 46), K. pneumoniae (n = 41), P. mirabilis (n = 12)] were taken from patients were identified in 1409 outpatient and 892 inpatients. Infection or colonization caused by ESBL-producing Enterobacteriaceae was considered to be hospital-acquired, healthcare-associated and community-acquired in 60.4%, 17.9% and 21.7% patients, respectively. Independent risk factors for ESBL-producing Enterobacteriaceae infection or colonization were male sex, cerebrovascular disease, intubation/tracheostomy, major surgery within 60 days (p < 0.001). Moreover, antimicrobial usage (more than 4 days) during preceding 60 days, especially aminoglycoside, oxazolidinone, tetracycline, fluoroquinolone, trimethoprim/sulfamethoxazole, and second- and fourth-generation cephalosporin were risk factors (p < 0.001). However, acquisition location of infection (hospital-acquired and community-onset) was not a risk factor (p > 0.05). The problem of ESBL production is no longer limited to hospital-acquired infections. The presence of chronic illness, such as cerebrovascular disease, and recent antimicrobial use were independent risk factors for ESBL-producing Enterobacteriaceae infection or colonization. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Cloning of cellobiose phosphoenolpyruvate-dependent phosphotransferase genes: Functional expression in recombinant Escherichia coli and identification of a putative binding region for disaccharides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, Xiaokuang; Davis, F.C.; Ingram, L.O.

1997-02-01

Genomic libraries from nine cellobiose-metabolizing bacteria were screened for cellobiose utilization. Positive clones were recovered from six libraries, all of which encode phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) proteins. Clones from Bacillus subtilis, Butyrivibrio fibrisolvens, and Klebsiella oxytoca allowed the growth of recombinant Escherichia coli in cellobiose-M9 minimal medium. The K. oxytoca clone, pLOI1906, exhibited an unusually broad substrate range (cellobiose, arbutin, salicin, and methylumbelliferyl derivatives of glucose, cellobiose, mannose, and xylose) and was sequenced. The insert in this plasmid encoded the carboxy-terminal region of a putative regulatory protein, cellobiose permease (single polypeptide), and phospho-{beta}-glucosidase, which appear to form an operon (casRAB).more » Subclones allowed both casA and casB to be expressed independently, as evidenced by in vitro complementation. An analysis of the translated sequences from the EIIC domains of cellobiose, aryl-{beta}-glucoside, and other disaccharide permeases allowed the identification of a 50-amino-acid conserved region. A disaccharide consensus sequence is proposed for the most conserved segment (13 amino acids), which may represent part of the EIIC active site for binding and phosphorylation. 63 refs., 4 figs., 4 tabs.« less

Complete Genome Sequence of Carbapenem-Resistant Klebsiella pneumoniae Strain 1756, Isolated from a Pus Specimen.

PubMed

Kao, Cheng-Yen; Yan, Jing-Jou; Lin, Yu-Chun; Zheng, Po-Xing; Wu, Jiunn-Jong

2017-03-30

Carbapenem-resistant Klebsiella pneumoniae strain 1756 was isolated from a pus specimen from a Taiwanese patient. Here, the complete genome sequence of strain 1756 is presented. Copyright © 2017 Kao et al.

Elimination of iron-containing magnetic nanoparticles from the site of injection in mice: a magnetic-resonance imaging study.

PubMed

Inzhevatkin, E V; Morozov, E V; Khilazheva, E D; Ladygina, V P; Stolyar, S V; Falaleev, O V

2015-04-01

Suspension of magnetic nanoparticles (0.7 g/liter) obtained from Klebsiella oxytoca culture was injected intraperitoneally (1 ml), intramuscularly (in the hip; 100 μl), and subcutaneously (200 μl) or administered orally instead of drinking water for 2 days. The presence of magnetic nanoparticles was evaluated detected by MRI in 15 min and 2 h after injections and in 1 and 2 days after the beginning of oral consumption of the suspension. Magnetic nanoparticles were eliminated from the site of intramuscular and intraperitoneal injections and after oral consumption. The period of elimination after intramuscular and intraperitoneal injections did not exceed 2 h, while after oral consumption it corresponded to the time of gastrointestinal tract contents evacuation.

[Post-marketing surveillance of antibacterial activities of cefozopran against various clinical isolates--II. Gram-negative bacteria].

PubMed

Igari, Jun; Oguri, Toyoko; Hiramatsu, Nobuyoshi; Akiyama, Kazumitsu; Koyama, Tsuneo

2002-02-01

As a post-marketing surveillance, the in vitro antibacterial activities of cefozopran (CZOP), an agent of cephems, against various clinical isolates were yearly evaluated and compared with those of other cephems, oxacephems, penicillins, monobactams, and carbapenems. Changes in CZOP susceptibility for the bacteria were also evaluated with the bacterial resistance ratio calculated with the breakpoint MIC. Twenty-five species (3,362 strains) of Gram-negative bacteria were isolated from the clinical materials annually collected from 1996 to 2000, and consisted of Moraxella (Branhamella) catarrhalis (n = 136), Haemophilus influenzae (n = 289), Escherichia coli (n = 276), Klebsiella pneumoniae (n = 192), Klebsiella oxytoca (n = 157), Enterobacter cloacae (n = 189), Enterobacter aerogenes (n = 93), Serratia marcescens (n = 172), Serratia liquefaciens (n = 24), Citrobacter freundii (n = 177), Citrobacter koseri (n = 70), Proteus mirabilis (n = 113), Proteus vulgaris (n = 89), Morganella morganii (n = 116), Providencia spp. (n = 41), Pseudomonas aeruginosa (n = 290), Pseudomonas fluorescens (n = 56), Pseudomonas putida (n = 63), Acinetobacter baumannii (n = 146), Acinetobacter lwoffii (n = 34), Burkholderia cepacia (n = 101), Stenotrophomonas maltophilia (n = 169), Bacteroides fragilis group (n = 196), and Prevotella/Porphyromonas (n = 173). An antibacterial activity of CZOP against E. coli, K. pneumoniae, K. oxytoca, and S. marcescens was potent and consistent with or more preferable than the study results obtained until the new drug application approval. MIC90 of CZOP against M.(B.) catarrhalis, C. koseri, and P. aeruginosa was not considerably changed and consistent with the study results obtained until the new drug application approval. MIC90 of CZOP against E. cloacae, E. aerogenes, and P. mirabilis increased year by year. The increase in MIC90 of CZOP against E. aerogenes and P. mirabilis, however, was not considered to be an obvious decline in susceptibility. In contract, the susceptibility of E. cloacae to CZOP was suspected to be decreasing because this species showed 20.6% resistance to CZOP. MIC90 of CZOP against C. freundii was variably changed or not one-sidedly, but was higher than the values obtained until the new drug application approval. Additionally, MIC90 of CZOP against H. influenzae was stable during 5 years except being higher in 1999, and, as a whole, was a little higher than the values obtained until the new drug application approval. An antibacterial activity of CZOP against P. fluorescens, P. putida, B. cepacia, S. maltophilia, B. fragilis group, and Prevotella/Porphyromonas was weak like the other cephems. Changes in MIC90 of CZOP against the other bacteria were 2 tubes or more through 5-year study period, but did not tend towards a unilateral direction as meaning a decline in susceptibility.

75 FR 76016 - Determination That AUGMENTIN `125' (Amoxicillin; Clavulanate Potassium) Chewable Tablet and Six...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-07

... by [beta]-lactamase-producing strains of Staphylococcus aureus, Escherichia coli, and Klebsiella spp.; and urinary tract infections, caused by [beta]-lactamase-producing strains of E. coli, Klebsiella spp...

Dissemination of successful international clone ST15 and clonal complex 17 among Bulgarian CTX-M-15 producing K. pneumoniae isolates.

PubMed

Markovska, Rumyana; Stoeva, Temenuga; Boyanova, Lyudmila; Stankova, Petya; Pencheva, Daniela; Keuleyan, Emma; Murjeva, Marianna; Sredkova, Marya; Ivanova, Dobrinka; Lazarova, Grozdanka; Nedelcheva, Gergana; Kaneva, Radka; Mitov, Ivan

2017-12-01

A total of 82 extended spectrum beta-lactamase (ESBL) producing Klebsiella pneumoniae and 4 Klebsiella oxytoca isolates were collected in 2014 from four geographical areas in Bulgaria and their multilocus sequence type (MLST) and transferability of the ESBL encoding genes were investigated. The predominant type was CTX-M-15 (87%), followed by CTX-M-3 (9%), SHV-12 or SHV-2 (2%) and CTX-M-14 (1%). The CTX-M-15 producers belonged to ST15 (34.1%) and to a lesser extent to CC17 (ST16, ST17, ST336). The CTX-M-15 transconjugants showed a presence of R, A/C 2 and F replicons. The CTX-M-3 producers were assigned to ST29, ST70, ST432, ST542 and ST15 types and the transconjugants carried M 2 replicons. To the best of our knowledge, this is the first report that fully describes the MLST types among Bulgarian ESBL producing K. pneumoniae and the first report of the detection of IncR plasmid replicon type in our country. Copyright © 2017 Elsevier Inc. All rights reserved.

In vitro activity of tigecycline and comparator agents against a global collection of Gram-negative and Gram-positive organisms: tigecycline Evaluation and Surveillance Trial 2004 to 2007.

PubMed

Garrison, Mark W; Mutters, Reinier; Dowzicky, Michael J

2009-11-01

The Tigecycline Evaluation and Surveillance Trial began in 2004 to monitor the in vitro activity of tigecycline and comparator agents against a global collection of Gram-negative and Gram-positive pathogens. Against Gram negatives (n = 63 699), tigecycline MIC(90)'s ranged from 0.25 to 2 mg/L for Escherichia coli, Haemophilus influenzae, Acinetobacter baumannii, Klebsiella oxytoca, Enterobacter cloacae, Klebsiella pneumoniae, and Serratia marcescens (but was > or =32 for Pseudomonas aeruginosa). Against Gram-positive organisms (n = 32 218), tigecycline MIC(90)'s were between 0.06 and 0.25 mg/L for Streptococcus pneumoniae, Enterococcus faecium, Streptococcus agalactiae, Staphylococcus aureus, and Enterococcus faecalis. The in vitro activity of tigecycline was maintained against resistant phenotypes, including multidrug-resistant A. baumannii (9.2% of isolates), extended-spectrum beta-lactamase-producing E. coli (7.0%) and K. pneumoniae (14.0%), beta-lactamase-producing H. influenzae (22.2%), methicillin-resistant S. aureus (44.5%), vancomycin-resistant E. faecium (45.9%) and E. faecalis (2.8%), and penicillin-resistant S. pneumoniae (13.8%). Tigecycline represents a welcome addition to the armamentarium against difficult to treat organisms.

Sanitary and bacteriological aspects of sewage treatment.

PubMed

Filipkowska, Zofia

2003-01-01

A study into the removal of contamination load and indicator bacteria was carried out in 1992-1996 in the mechanical, biological and chemical waste-water treatment plant WTP in Lezany, in the County of Reszel, in the Province of Warmia and Mazury in Poland. The results of chemical analyses found a high efficiency of removal of carbon compounds, COD (90%) and BOD (98%), in the process of purification of household sewage. In addition, a high effectiveness of total nitrogen, on average 71%, and unsatisfactory removal of ammonia nitrogen and phosphorus compounds were found. The results of microbiological analyses confirmed the high efficiency of removal of indicator bacteria in the process of sewage treatment from 94 to 97%. In the sewage after the final phase of purification in stabilization ponds, the following pathogenic bacteria were identified with the use of the EPL 21tests: Escherichia coli, Enterobacter agglomerans, Enterobacter aerogenes, Enterobacter cloacae, Enterobacter georgoriae, Citrobacter freundii, Klebsiella pnemoniae, Klebsiella oxytoca, Klebsiella ozaenae, Ervinia herbicola, Edwardsiella tarda, Serratia odoriefra, Serratia marcescens, Providencia alcalifaciens, Hafnia alvei, Yersina pestis, Yersina pseudotuberculosis, Yersinia fredericksenii, Salmonella spp., Shigella dysenteriae, Aeromons hydrophila, Pseudomonas aerulginosa. The obtained results show that although the sewage purification system is efficient and reduces the contamination load to the level required by the regulations (Ministry of Environmental Protection, Natural Resources and Forestry from 20 September 1991) and removes a great percentage of indicator bacteria, the purified sewage may be a source of pathogenic bacteria in inland waters.

Australian Group on Antimicrobial Resistance Australian Enterobacteriaceae Sepsis Outcome Programme annual report, 2014.

PubMed

Bell, Jan M; Turnidge, John D; Coombs, Geoffrey W; Daley, Denise A; Gottlieb, Thomas; Robson, Jenny; George, Narelle

2016-06-30

The Australian Group on Antimicrobial Resistance performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric Gram-negative pathogens. The 2014 survey was the second year to focus on blood stream infections. During 2014, 5,798 Enterobacteriaceae species isolates were tested using commercial automated methods (Vitek 2, BioMérieux; Phoenix, BD) and results were analysed using the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints (January 2015). Of the key resistances, non-susceptibility to the third-generation cephalosporin, ceftriaxone, was found in 9.0%/9.0% of Escherichia coli (CLSI/EUCAST criteria) and 7.8%/7.8% of Klebsiella pneumoniae, and 8.0%/8.0% K. oxytoca. Non-susceptibility rates to ciprofloxacin were 10.4%/11.6% for E. coli, 5.0%/7.7% for K. pneumoniae, 0.4%/0.4% for K. oxytoca, and 3.5%/6.5% in Enterobacter cloacae. Resistance rates to piperacillin-tazobactam were 3.2%/6.8%, 4.8%/7.2%, 11.1%/11.5%, and 19.0%/24.7% for the same 4 species respectively. Fourteen isolates were shown to harbour a carbapenemase gene, 7 blaIMP-4, 3 blaKPC-2, 3 blaVIM-1, 1 blaNDM-4, and 1 blaOXA-181-lke.

The effects of bee pollen extracts on the broiler chicken's gastrointestinal microflora.

PubMed

Kačániová, Miroslava; Rovná, Katarína; Arpášová, Henrieta; Hleba, Lukáš; Petrová, Jana; Haščík, Peter; Cuboň, Juraj; Pavelková, Adriana; Chlebo, Róbert; Bobková, Alica; Stričík, Michal

2013-08-01

The aim of this study was to investigate the effects of bee pollen ethanolic extracts on the in vivo gastrointestinal tract microflora colonization of broiler chickens. A completely randomized experiment based on six treatments (different concentrations of bee pollen - 0, 5, 15, 25, 35 and 45 g kg(-1) diet) was used during 7 weeks. The highest count of faecal Enterococci was found in the experimental group with the addition of 15 g of pollen (8.85 ± 0.87 log CFU g(-1)) per 1 kg of feed mixture. The highest count of Lactobacilli was detected in the experimental group with 35 g of pollen per 1 kg of feed mixture and the highest number of the Enterobacteriaceae genera count was found in the control group (8.43 ± 0.15 log CFU g(-1)). Moreover, the MALDI TOF MS Biotyper identified the following genera: Escherichia coli, Proteus mirabilis, Klebsiella oxytoca, as well as Lactobacillus acidophilus, L. crispatus, L. fermentum and L. salivarius from the Lactobacilli group and Enterococcus avium, E. casseliflavus, E. cecorum, E. faecalis, E. faecium, E. gallinarum, E. hirae and E. malodoratus from the Enterococci group. Additionally, the in vitro antimicrobial activities of pollen against five bacteria species isolated from gastrointestinal tracts of chickens were tested. The best antimicrobial effect of the pollen extract was detected against K. oxytoca. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Changes in the structure of pathogens of calculous pyelonephritis complicated with diabetes mellitus type ii, in the hospital urology of the city of Volgograd].

PubMed

Petrov, V I; Vinarov, A Z; Vekilyan, M A; Kulchenko, N G

2016-08-01

Among the diseases complicating the course of calculous pyelonephritis, are among the leaders of diabetes mellitus, which is associated with reduced immune response, deterioration of renal hemodynamics, the reduced sensitivity to antibacterial drugs. The purpose of the study is to improve the results of treatment of patients with calculous pyelonephritis and diabetes mellitus type 2. The materials and methods of research. We studied 179 people. This was a retrospective pharmaco-epidemiological analysis of medical records of patients who were treated in 2009 and 2013, in hospital of Volgograd. Women in the study was greater than 99(by 55.4%), males - 80 (44,6%). All patients underwent standard clinical examination, with mandatory bacteriological urine analysis, ultrasound study of kidneys. During the observation period of 2009 and 2013 in patients with calculous pyelonephritis and type 2 diabetes, the major pathogens were representatives of the family Enterobacteriaceae. E.coli strains are constituted - 12 (54,5%), K. pneumoniae - 4 (18.1%) strains. In other etiologically significant microorganisms were Enterococcus spp. - 3 (13.6%) strain, P. aeruginosa - strain 2 (9%). The group of other (4.5%), we have carried pathogens isolated in the singular: Erobacter spp, S. aureus, and Klebsiella oxytoca. In patients with infection of the upper urinary tract and diabetes, there is a pronounced trend to decrease sensitivity to all groups of antibiotics. Sensitivity to unprotected penicillins and fluoroquinolones has decreased almost twice. Resistance to aminoglycosides of patients in this group increased by 23%. In patients with chronic calculous pyelonephritis and diabetes mellitus type 2 is high sensitivity of the main causative agents of infection to cephalosporins of the third and fourth generation (92%), protected beta-lactam penicillins (amoxicillin/clavulanate) - 86,4%, to carbapenemam is 89.4%. For the empiric treatment of infections of the upper urinary tract in patients with diabetes mellitus, can be recommended drugs: protected beta-lactam penicillins, cephalosporins of the third and fourth generation, carbapenem.

Occurrence of blaNDM Variants Among Enterobacteriaceae From a Neonatal Intensive Care Unit in a Northern India Hospital

PubMed Central

Ahmad, Nayeem; Khalid, Shamsi; Ali, Syed M.; Khan, Asad U.

2018-01-01

Carbapenem-resistance among enterobacteriaceae has become a global health concern. The objective of this study was to understand NDM producing enterobacteriaceae and their genetic basis of resistance, spreading in neonatal intensive care unit. Carbapenem resistant NDM producing enterobacteriaceae isolates were recovered from rectal swab and blood sample of infants admitted in NICU. These were determined by using Carba-NP test. All isolates were identified using BD PhoenixTM−100 and MICs were determined by broth microdilution method. The blaNDM and associated resistant markers were checked by PCR followed by sequencing. Moreover, ERIC-PCR and genetic environment of blaNDM gene were also performed for the analysis of clonal relationship and genetic surrounding of the strains. We characterized 44 isolates with blaNDM variants in Escherichia coli (45.5%), Klebsiella pneumoniae (40.9%), Citrobacter freundii (4.5%), Citrobacter braakii (2.3%), Klebsiella oxytoca (2.3%), Enterobacter cloacae (2.3%), Enterobacter aerogenes (2.2%) from NICU, showing resistance against all antibiotics except colistin and polymixin B. ISAba125 and bleomycin gene were found surrounding all blaNDM variants, besides class I integron on plasmid. (ERIC)-PCR data revealed non-clonal relatedness among most of the isolates. The transfer of resistant markers was confirmed by conjugation experiment. The PCR-based replicon typing was carried out using DNA of transconjugants. These isolates carried NDM-1 (20.45%), NDM-4 (36.36%), NDM-5 (38.64%), NDM-7 (4.55%), along with OXA, CMY, and SHV variants on conjugative plasmid of IncFIA, IncFIC, IncF, IncK, IncFIB, IncB/O, IncHI1, IncP, IncY, IncFIIA, IncI1, and IncN types. An increased number of carbapenem-resistant NDM producing enterobacteriaceae isolates recovered from NICU which is alarming signal for health workers and policy makers. Hence, it is utmost important to think about infection control measures. PMID:29563908

Hexavalent Molybdenum Reduction to Mo-Blue by a Sodium-Dodecyl-Sulfate-Degrading Klebsiella oxytoca Strain DRY14

PubMed Central

Halmi, M. I. E.; Zuhainis, S. W.; Yusof, M. T.; Shaharuddin, N. A.; Helmi, W.; Shukor, Y.; Syed, M. A.; Ahmad, S. A.

2013-01-01

Bacteria with the ability to tolerate, remove, and/or degrade several xenobiotics simultaneously are urgently needed for remediation of polluted sites. A previously isolated bacterium with sodium dodecyl sulfate- (SDS-) degrading capacity was found to be able to reduce molybdenum to the nontoxic molybdenum blue. The optimal pH, carbon source, molybdate concentration, and temperature supporting molybdate reduction were pH 7.0, glucose at 1.5% (w/v), between 25 and 30 mM, and 25°C, respectively. The optimum phosphate concentration for molybdate reduction was 5 mM. The Mo-blue produced exhibits an absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. None of the respiratory inhibitors tested showed any inhibition to the molybdenum-reducing activity suggesting that the electron transport system of this bacterium is not the site of molybdenum reduction. Chromium, cadmium, silver, copper, mercury, and lead caused approximately 77, 65, 77, 89, 80, and 80% inhibition of the molybdenum-reducing activity, respectively. Ferrous and stannous ions markedly increased the activity of molybdenum-reducing activity in this bacterium. The maximum tolerable concentration of SDS as a cocontaminant was 3 g/L. The characteristics of this bacterium make it a suitable candidate for molybdenum bioremediation of sites cocontaminated with detergent pollutant. PMID:24383052

Genetic diversity of genes encoding OKP and LEN beta-lactamases produced by clinical Klebsiella pneumoniae strains in Portugal.

PubMed

Mendonça, Nuno; Ferreira, Eugénia; Caniça, Manuela

2009-03-01

Of the 308 clinical Klebsiella pneumoniae strains collected in 21 Portuguese health institutions, 11 encoded for LEN and 9 for OKP enzymes; of these, 15 were new enzymes. Ninety-one percent of LEN and all OKP producer strains were resistant to amoxicillin. We demonstrate that these beta-lactamase were highly diverse.

Occurrence of Extended Spectrum β-Lactamases, KPC-Type, and MCR-1.2-Producing Enterobacteriaceae from Wells, River Water, and Wastewater Treatment Plants in Oltrepò Pavese Area, Northern Italy

PubMed Central

Caltagirone, Mariasofia; Nucleo, Elisabetta; Spalla, Melissa; Zara, Francesca; Novazzi, Federica; Marchetti, Vittoria M.; Piazza, Aurora; Bitar, Ibrahim; De Cicco, Marica; Paolucci, Stefania; Pilla, Giorgio; Migliavacca, Roberta; Pagani, Laura

2017-01-01

To evaluate the water compartment antibiotic-resistance contamination rates, 11 wells, five streams, and four treatment plants located in the Oltrepò Pavese area were screened for the presence of third generation cephalosporins resistant Gram-negative bacteria. Enterobacteriaceae were also characterized for the Extended-Spectrum-β-Lactamases (ESBLs), carbapenemases, and mcr-1 genes presence. From December 2014 to November 2015, 246 water samples were filtered, plated on Plate Count Agar, MacConkey Agar, and MacConkey Agar with cefotaxime. Isolates were species identified using AutoSCAN-4-System and ESBLs, carbapenemases, and colistin resistance determinants were characterized by PCR, sequencing, and microarray. Plasmid conjugative transfer experiments, PCR-based Replicon typing, Pulsed-Field Gel Electrophoresis, Multi-Locus-Sequence-Typing, and in-silico plasmid characterization were performed. A total of 132 enterobacteria isolates grew on MacConkey agar with cefotaxime: 82 (62.1%) were obtained from streams, 41 (31.1%) from treatment plants, and 9 (6.8%) from wells. Thirty out of 132 (22.7%) isolates, mainly belonging to Escherichia coli (n = 15) species, showed a synergic effect with piperacillin-tazobactam. A single ESBL gene of blaCTX−M-type was identified in 19/30 isolates. In further two E. coli strains, a blaCTX−M−1 gene co-existed with a blaSHV-type ESBL determinant. A blaSHV−12 gene was detected in two isolates of E. coli (n = 1) and Klebsiella oxytoca (n = 1), while any ESBL determinant was ascertained in seven Yersinia enterocolitica strains. A blaDHA-type gene was detected in a cefoxitin resistant Y. enterocolitica from a stream. Interestingly, two Klebsiella pneumoniae strains of ST307 and ST258, collected from a well and a wastewater treatment plant, resulted KPC-2, and KPC-3 producers, respectively. Moreover, we report the first detection of mcr-1.2 ST10 E. coli on a conjugative IncX4 plasmid (33.303 bp in size) from a stream of Oltrepò Pavese (Northern Italy). Both ESBLs E. coli and ESBLs/carbapenemase-producing K. pneumoniae strains showed clonal heterogeneity by Pulsed-Field Gel Electrophoresis and Multi-Locus-Sequence-Typing. During one-year study and taking in account the whole Gram-negative bacterial population, an average percentage of cefotaxime resistance of 69, 32, and 10.3% has been obtained for the wastewater treatment plants, streams, and wells, respectively. These results, of concern for public health, highlight the need to improve hygienic measures to reduce the load of discharged bacteria with emerging resistance mechanisms. PMID:29176971

Complete genome sequence of a Klebsiella pneumoniae strain isolated from a known cotton insect boll vector

USDA-ARS?s Scientific Manuscript database

Klebsiella pneumoniae (associated with bacterial pneumonia) was previously isolated from Nezara viridula, a significant vector of cotton boll-rot pathogens. We provide the first annotated genome sequence of the cotton opportunistic strain K. pneumoniae 5-1. This data provides guidance to study the...

Differential Microbial Diversity in Drosophila melanogaster: Are Fruit Flies Potential Vectors of Opportunistic Pathogens?

PubMed Central

Maldonado-Morales, Génesis; Bayman, Paul

2017-01-01

Drosophila melanogaster has become a model system to study interactions between innate immunity and microbial pathogens, yet many aspects regarding its microbial community and interactions with pathogens remain unclear. In this study wild D. melanogaster were collected from tropical fruits in Puerto Rico to test how the microbiota is distributed and to compare the culturable diversity of fungi and bacteria. Additionally, we investigated whether flies are potential vectors of human and plant pathogens. Eighteen species of fungi and twelve species of bacteria were isolated from wild flies. The most abundant microorganisms identified were the yeast Candida inconspicua and the bacterium Klebsiella sp. The yeast Issatchenkia hanoiensis was significantly more common internally than externally in flies. Species richness was higher in fungi than in bacteria, but diversity was lower in fungi than in bacteria. The microbial composition of flies was similar internally and externally. We identified a variety of opportunistic human and plant pathogens in flies such as Alcaligenes faecalis, Aspergillus flavus, A. fumigatus, A. niger, Fusarium equiseti/oxysporum, Geotrichum candidum, Klebsiella oxytoca, Microbacterium oxydans, and Stenotrophomonas maltophilia. Despite its utility as a model system, D. melanogaster can be a vector of microorganisms that represent a potential risk to plant and public health. PMID:29234354

[Phenotypic and molecular identification of extended-spectrum beta-lactamase (ESBL) TEM and SHV produced by clinical isolates Escherichia coli and Klebsiella spp. in hospitals].

PubMed

González Mesa, Leonora; Ramos Morí, Astrid; Nadal Becerra, Loreta; Morffi Figueroa, Janet; Hernández Robledo, Ernesto; Alvarez, Ana Berta; Marchena Bequer, Juan J; González Alemán, Mabel; Villain Plous, Carlos

2007-01-01

Nosocomial infections caused by gram-negative bacilli which produce extended spectrum beta-lactamase (ESBL) are associated with the increase of morbidity and mortality in hospitals. The objective of this study was to evaluate the frequency of ESBL, specifically the TEM and SHV type, produced by Escherichia coli and Klebsiella spp. strains, and also to determine the antimicrobial susceptibility of these isolates in comparison with other antibiotic families. A total of 326 strains were collected between 2002-2004 from hospitals in Havana City. The susceptibility tests were carried out according to the NCCLS guides and they were confirmed as. ESBL producers by the double disk diffusion method. The molecular characterization of these enzymes was determined by polymerase chain reaction (PCR), using two sets of oligonucleotides to amplify genes encoding TEM and SHV type beta-lactamase. The ESBL phenotype was detected in 31 (10%) Escherichia coli isolates, 19 of these strains (61%) carried the blaTEM genes, 5 (16%) blaSHV genes, 4 (12%) strains carried both genes and 11 strains (35%) carried the non-ESBL blaTEM and blaSHV genes. In Klebsiella spp. the ESBL phenotype was detected in 10 (36 %) isolates, only one strain carried the blaTEM gene. The most active antimicrobials against Escherichia coli were ciprofloxacin (64.5%) and gentamicin (58.07%); in the case of Klebsiella spp. the same antimicrobials were the most active with similar susceptibility (70%) for both. The carbapenems still remain the most active antibiotics against Escherichia coli and Klebsiella spp. strains, which are ESBL producers. However, their use should be closely controlled.

Enterobacter and Klebsiella species isolated from fresh vegetables marketed in Valencia (Spain) and their clinically relevant resistances to chemotherapeutic agents.

PubMed

Falomir, María Pilar; Rico, Hortensia; Gozalbo, Daniel

2013-12-01

Occurrence of antibiotic-resistant pathogenic or commensal enterobacteria in marketed agricultural foodstuffs may contribute to their incorporation into the food chain and constitutes an additional food safety concern. In this work, we have determined the clinically relevant resistances to 11 common chemotherapeutic agents in Enterobacter and Klebsiella isolates from fresh vegetables from various sources (supermarkets and greengrocers' shops in Valencia, Spain). A total of 96 isolates were obtained from 160 vegetables analyzed (50% positive samples): 68 Enterobacter isolates (59 E. cloacae, two E. aerogenes, two E. cancerogenus, one E. gergoviae, and four E. sakazakii, currently Cronobacter spp.), and 28 Klebsiella isolates (19 K. oxytoca and 9 K. pneumoniae). Only seven isolates were susceptible to all agents tested, and no resistances to ceftazidime, ciprofloxacin, gentamicin, and chloramphenicol were detected. Most isolates were resistant to amoxicillin/clavulanic acid (74 [58 Enterobacter and 16 Klebsiella]) or to ampicillin (80 [55/25]). Other resistances were less frequent: nitrofurantoin (13 isolates [12/1]), tetracycline (6 [5/1]), co-trimoxazole (3 [3/0]), cefotaxime (1 [1/0]), and streptomycin (2 [1/1]). Multiresistant isolates to two (56 [41/15]), three (10 E. cloacae isolates), four (one E. cloacae and one K. pneumoniae isolate), and five (two E. cloacae isolates) chemotherapeutic agents were also detected. The presence of potential pathogens points to marketed fresh produce, which often is eaten raw, as a risk factor for consumer health. In addition, these results support the usefulness of these bacterial species as indicators of the spreading of antibiotic resistances into the environment, particularly in the food chain, and suggest their role as carriers of resistance determinants from farms to consumers, which may constitute an additional "silent" food safety concern. Therefore, there is a need to improve the hygienic quality of marketed fresh vegetables, from better methods to prevent contamination in the farms to the use of sanitizing practices at home.

Identification of putative plant pathogenic determinants from a draft genome sequence of an opportunistic klebsiella pneumoniae strain

USDA-ARS?s Scientific Manuscript database

Klebsiella pneumoniae has been known historically as a causal agent of bacterial pneumonia. More recently, K. pneumoniaerepresentatives have been shown to have a broad ecological distribution and are recognized nitrogen-fixers. Previously, we demonstrated the capacity of K. pneumoniae strain Kp 5-1R...

Distribution of CTX-M group I and group III β-lactamases produced by Escherichia coli and klebsiella pneumoniae in Lahore, Pakistan.

PubMed

Abrar, Samyyia; Vajeeha, Ayesha; Ul-Ain, Noor; Riaz, Saba

2017-02-01

Extended-spectrum-lactamases (ESBLs) of the CTX-M type is worrisome issue in many countries of the world from past decade. But little is known about CTX-M beta-lactamase producing bacteria in Pakistan. Therefore, this study was carried out to investigate the distribution of CTX-M beta-lactamase producing E. coli and Klebsiella pneumoniae using phenotypic and molecular techniques. A total of 638 E. coli and 338 Klebsiella pneumoniae were isolated from patients attending two hospitals and one diagnostic Centre in Pakistan during 2013-2015. ESBL production was screened by double disc synergism, combination disc (cefotaxime and ceftazidime with clavulanic acid) and E-test. These strains were further characterized by PCR (CTX-M I, CTX-M III) and sequencing. After ribotyping of strains accession numbers were obtained. These isolates were highly resistant to cephalosporins, ceftazidime, cefotaxime, aztreonam, and cefuroxime but susceptible to carbapenems, sulfzone, amikacin and tazocin. Multiple antibiotic resistances index (MAR) revealed that 51% of E. coli strains fell in the range of 0.61-0.7 and 39% of Klebsiella pneumoniae strains fell in the range of 0.71-0.8. 64% Double disc synergism (DDS), 76.4% combination disc (CD), 74% E-test showed ESBL positivity in strains. In E. coli ESBL genes bla CTX-M-I and bla CTX-M-III were detected in 212 (72.1%) and 25 (8.5%) respectively. In Klebsiella pneumoniae ESBL genes bla CTX-M-I and bla CTX-M-III were detected in 89 (82.4%) and 10 (9.2%). Combination of both genes bla CTX-M-I and bla CTX-M-III were found in 16 (5.4%) of E. coli strains and 5 (4.6%) of Klebsiella pneumoniae strains. Sequencing revealed that CTXM-15 was predominately present in the CTX-M-I group. The prevalence of ESBL producing E. coli and Klebsiella pneumoniae isolates was high and the majority of them positive for bla CTX-M-I as compared to bla CTX-M-III. These findings highlight the need to further investigate the epidemiology of other CTX-M beta-lactamases in Pakistan. Copyright © 2016 Elsevier Ltd. All rights reserved.

Demonstration that a Klebsiella pneumoniae subsp. pneumoniae isolated from an insect (Nezara viridula) harbors a functional plasmid-borne type IV secretion system

USDA-ARS?s Scientific Manuscript database

Previously, we reported the isolation of Klebsiella pneumoniae subspecies pneumoniae strain Kp 5-1 from a southern green stink bug (Nezara viridula) that is a significant pest of numerous economically important crops. We subsequently sequenced the strains whole genome. Here, we report the presence...

Commensal Bacteria Aid Mate-selection in the Fruit Fly, Bactrocera dorsalis.

PubMed

Damodaram, Kamala Jayanthi Pagadala; Ayyasamy, Arthikirubha; Kempraj, Vivek

2016-10-01

Commensal bacteria influence many aspects of an organism's behaviour. However, studies on the influence of commensal bacteria in insect mate-selection are scarce. Here, we present empirical evidence that commensal bacteria mediate mate-selection in the Oriental fruit fly, Bactrocera dorsalis. Male flies were attracted to female flies, but this attraction was abolished when female flies were fed with antibiotics, suggesting the role of the fly's microbiota in mediating mate-selection. We show that male flies were attracted to and ejaculated more sperm into females harbouring the microbiota. Using culturing and 16S rDNA sequencing, we isolated and identified different commensal bacteria, with Klebsiella oxytoca being the most abundant bacterial species. This preliminary study will enhance our understanding of the influence of commensal bacteria on mate-selection behaviour of B. dorsalis and may find use in devising control operations against this devastating pest.

The study on molecular structure and microbiological activity of alkali metal 3-hydroxyphenylycetates

NASA Astrophysics Data System (ADS)

Samsonowicz, M.; Regulska, E.; Kowczyk-Sadowy, M.; Butarewicz, A.; Lewandowski, W.

2017-10-01

The biological activity of chemical compounds depends on their molecular structure. In this paper molecular structure of 3-hydroxyphenylacetates in comparison to 3-hydroxyphenylacetic acid was studied. FT-IR, FT-Raman and NMR spectroscopy and density functional theory (DFT) calculations was used. The B3LYP/6-311++G(d,p) hybrid functional method was used to calculate optimized geometrical structures of studied compounds. The Mulliken, APT, MK, ChelpG and NBO atomic charges as well as dipole moment and energy values were calculated. Theoretical chemical shifts in NMR spectra and the wavenumbers and intensities of the bands in vibrational spectra were analyzed. Calculated parameters were compared to experimental characteristic of studied compounds. Microbiological analysis of studied compounds was performed relative to: Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Klebsiella oxytoca. The relationship between spectroscopic and structure parameters of studied compounds in regard to their activity was analyzed.

Salivary defense system alters in vegetarian

PubMed Central

Amirmozafari, Nour; Pourghafar, Houra; Sariri, Reyhaneh

2013-01-01

Purpose The aim of this research was investigating antimicrobial and enzymatic antioxidant activities in salivary fluids of vegetarians as compared to normal subjects. Material & Methods Antimicrobial activity of the saliva samples was evaluated against four clinically important bacteria. The biological activities of three of the main antioxidant enzymes of saliva were measured using appropriate methods of enzyme assay in both groups. Results According to the results, saliva obtained from vegetarians showed a reduced inhibitory effect on growth of Staphylococcus aureus, Klebsiella oxytoca, Pseudomonas aeruginosa and Escherichia coli as compared to those obtained from the non-vegetarian subjects. The activity of salivary peroxidase, catalase and superoxide dismutase showed a statistically marked decrease in vegetarian group. Conclusions According to our literature survey, this is the first report on the antibacterial and antioxidant capacity in saliva of vegetarians. Results obtained from the present study have opened a new line of research with the basis of saliva as a research tool. PMID:25737889

Digestion of cellulose and xylan by symbiotic bacteria in the intestine of the Indian flying fox (Pteropus giganteus).

PubMed

Prem Anand, A Alwin; Sripathi, K

2004-09-01

Bats (Order Chiroptera) are a widely distributed group of mammals. Pteropus giganteus belongs to the Suborder Megachiroptera. This bat consumes fruits and leaves as their major food. Cellulose and xylan are the major composition of leaves. As they consume leaves in their diet, their digestive tract must contain cellulolytic and xylanolytic bacteria which help in the digestion of cellulose and xylan. The cellulolytic and xylanolytic bacteria were isolated and screened on Berg's agar containing cellulose and xylan. The bacteria isolated were characterized biochemically and found to be Proteus vulgaris, Proteus mirabilis, Citrobacter freundii, Serratia liquefaciens and Klebsiella oxytoca. These bacteria help in digestion of cellulose and xylan in the diet of the bat, P. giganteus. Here we show that leaves are also used as a carbohydrate source by these bats. An insectivorous bat, Hipposideros fulvus, was used as a control and does not possess cellulolytic and xylanolytic bacteria.

Genotypic and phenotypic characters and nosocomial significance of bacteria endemic in neonatal intensive care units.

PubMed

Milch, H; Czirók, E; Herpay, M; Gadó, I; Barcs, I

1994-01-01

The degree of colonization was determined by complex typing (sero-, phage, colicin-, pyocin typing, plasmid profile analysis) of 212 Escherichia coli, 232 Klebsiella, 117 Pseudomonas aeruginosa and 52 Staphylococcus aureus strains isolated from nose, throat, ear and other sources of 563 new-born infants in gynaecological and maternity wards of two neonatal intensive care units (NICU I and II) during a one year period. The presence of Klebsiella strains was more frequent in NICU I and E. coli and P. aeruginosa in NICU II, S. aureus occurred in a low level in both units. In NICU I 34 kinds, in NICU II 43 kinds of E. coli serotype were found. In NICU I the accumulation of serotypes O6:H-, O6:H1, O19:H-, in NICU II O4:H-, O6:H1 was observed. The Klebsiella strains belonged in NICU I into 21, in NICU II into 12 phage types. Klebsiella was more frequent in NICU I than in NICU II, though the strains belonged to the same phage type in NICU II in 50.7%, but in NICU I 4 frequent and 19 rare phage types occurred. Sero- and pyocin typing was effective for typing of P. aeruginosa. The most frequent sero- and pyocin types were in NICU I:O11a,11b; in NICU II: O2a,2d,2f; 12v. The rate of antibiotic resistance in E. coli, Klebsiella, P. aeruginosa and S. aureus was nearly the same in both units, multiple resistance was more frequent in NICU I (except P. aeruginosa, it was multiple resistant in 100% in both units). In NICU I 267, in NICU II 174 infants were treated with antibiotics. The administration of penicillin derivatives was nearly similar in the two care units and the resistance among E. coli and Klebsiella strains was nearly the same too. Though, cephalosporins were used more frequently in NICU II, resistance to cephalosporins among E. coli and Klebsiella was a bit higher in NICU I. Aminoglycosides were more often used in NICU I, resistance to aminoglycosides among E. coli and Klebsiella was higher in this unit. The rate of isolation of the examined bacteria was significantly lower in the group treated with antibiotics, than in the untreated group.

mcr-1 Colistin Resistance in ESBL-Producing Klebsiella pneumoniae, France

PubMed Central

Maillet, Mylène; Pavese, Patricia; Francony, Gilles; Brion, Jean-Paul; Mallaret, Marie-Reine; Bonnet, Richard; Robin, Frédéric; Beyrouthy, Racha; Maurin, Max

2017-01-01

We report intestinal carriage of an extended-spectrum β-lactamase−producing Klebsiella pneumoniae strain with high-level resistance to colistin (MIC 24 mg/L) in a patient in France who had been hospitalized for fungal meningitis. The strain had the mcr-1 plasmid gene and an inactivated mgrB gene, which are associated with colistin resistance. PMID:28418313

Effect of Acetate upon the Formation of Acetoin in Klebsiella and Enterobacter and its Possible Practical Application in a Rapid Voges-Proskauer Test

PubMed Central

Bryn, Klaus; Ulstrup, Jan C.; Størmer, Fredrik C.

1973-01-01

Acetate stimulates the formation of acetoin during 1-h incubation of Voges-Proskauer-positive strains of Klebsiella and Enterobacter. Of these organisms, 124 of 126 strains were recognized as positive in the presence of acetate, and 106 were recognized as positive in its absence. PMID:4572901

Pectin-rich biomass as feedstock for fuel ethanol production.

PubMed

Edwards, Meredith C; Doran-Peterson, Joy

2012-08-01

The USA has proposed that 30 % of liquid transportation fuel be produced from renewable resources by 2030 (Perlack and Stokes 2011). It will be impossible to reach this goal using corn kernel-based ethanol alone. Pectin-rich biomass, an under-utilized waste product of the sugar and juice industry, can augment US ethanol supplies by capitalizing on this already established feedstock. Currently, pectin-rich biomass is sold (at low value) as animal feed. This review focuses on the three most studied types of pectin-rich biomass: sugar beet pulp, citrus waste and apple pomace. Fermentations of these materials have been conducted with a variety of ethanologens, including yeasts and bacteria. Escherichia coli can ferment a wide range of sugars including galacturonic acid, the primary component of pectin. However, the mixed acid metabolism of E. coli can produce unwanted side products. Saccharomyces cerevisiae cannot naturally ferment galacturonic acid nor pentose sugars but has a homoethanol pathway. Erwinia chrysanthemi is capable of degrading many of the cell wall components of pectin-rich materials, including pectin. Klebsiella oxytoca can metabolize a diverse array of sugars including cellobiose, one degradation product of cellulose. However, both E. chrysanthemi and K. oxytoca produce side products during fermentation, similar to E. coli. Using pectin-rich residues from industrial processes is beneficial because the material is already collected and partially pretreated to facilitate enzymatic deconstruction of the plant cell walls. Using biomass already produced for other purposes is an attractive practice because fewer greenhouse gases (GHG) will be anticipated from land-use changes.

[RATIONAL ASPECTS OF BACTERIOPHAGES USE].

PubMed

Vakarina, A A; Kataeva, L V; Karpukhina, N F

2015-01-01

Analysis of existing aspects of bacteriophage use and study features of their lytic activity by using various techniques. Effect of monophages and associated bacteriophages (staphylococci, piopolyvalent and piocombined, intestiphage, pneumonia klebsiella and polyvalent klebsiella produced by "Microgen") was studied with 380 strains of Staphylococcus aureus and 279 cultures of Klebsiella pneumoniae in liquid and solid nutrient media. From patients with intestinal disorder, sensitivity was analyzed to 184 strains of Salmonella genus bacteria 18 serological variants to salmonella bacteriophages, 137 strains of Escherichia coli (lactose-negative, hemolytic), as well as some members of OKA groups (21 serovars) to coli-proteic and piopolyvalent bacteriophages. Lytic ability of the piobacteriophage against Klebsiella and Proteus genus bacteria was determined. Staphylococcus aureus was sensitive to staphylococcus bacteriophage in 71.6% of cases and to piobacteriophage--in 86.15% of cases. A 100% lytic ability of salmonella bacteriophage against Salmonella spp. was established. Sensitivity of E. coli of various serogroups to coli-proteic and piobacteriophage was 66 - 100%. Klebsiella, Proteus genus bacteria were sensitive to piobacteriophage in only 35% and 43.15% of cases, respectively. A more rational use of bacteriophages is necessary: development of a technique, evaluation of sensitivity of bacteria to bacteriophage, introduction of corrections into their production (expansion of bacteriophage spectra, determination and indication of their concentration in accompanying documents).

Klebsiella pneumoniae Strains Producing Extended-Spectrum β-Lactamases in Spain: Microbiological and Clinical Features▿

PubMed Central

de Alegría, C. Ruiz; Rodríguez-Baño, J.; Cano, M. E.; Hernández-Bello, J. R.; Calvo, J.; Román, E.; Díaz, M. A.; Pascual, A.; Martínez-Martínez, L.

2011-01-01

Extended-spectrum β-lactamases (ESBL) of the CTX-M, SHV, and TEM families were recognized in 76 (67%), 31 (27%), and 6 (5%) isolates, respectively, among 162 ESBL-producing Klebsiella pneumoniae (ESBL-Kp) strains obtained in a multicenter study in Spain. Predisposing factors for ESBL-Kp acquisition included invasive procedures, mechanical ventilation, and previous antimicrobial use. PMID:21191059

Structural characterization and biomedical properties of sulfated polysaccharide from the gladius of Sepioteuthis lessoniana (Lesson, 1831).

PubMed

Seedevi, Palaniappan; Moovendhan, Meivelu; Vairamani, Shanmugam; Shanmugam, Annian

2016-04-01

Sulfated polysaccharide was extracted from the internal shell (gladius) of Sepioteuthis lessoniana. The sulfated polysaccharide contained 61.3% of carbohydrate, 0.8% of protein, 28.2% of ash and 1.33% of moisture respectively. The elemental composition was analyzed using CHNS/O analyzer. The molecular weight of sulfated polysaccharide determined through PAGE was found to be as 66 kDa. Monosaccharides analysis revealed that sulfated polysaccharide was composed of rhamnose, galactose, xylose and glucose. The structural features of sulfated polysaccharide were analyzed by FT-IR and NMR spectroscopy. Further the sulfated polysaccharide was evaluated for its antibacterial activity against selected human clinical pathogens, namely Staphylococcus aureus, Klebsiella pneumoniae, Salmonella typhi, Vibrio cholerae, Klebsiella oxytoca, Escherichia coli, Salmonella paratyphi, Proteus mirabilis, Vibrio parahaemolyticus and Streptococcus pyogenes using agar well diffusion method. The polysaccharide has showed good antibacterial activity and MIC and MBC have also been evaluated. The anticancer activity was tested against HeLa cell line by MTT assay. The Cytotoxic Concentration (CC50) was observed as 700 μg/ml and the maximum anticancer activity of 62.89% was recorded at 200 μg/ml; whereas, the lowest of 9.87% was observed at 25 μg/ml. In conclusion, the sulfated polysaccharide is an alternate, non-toxic and cheap source of substance that showed good antibacterial and anticancer acitivity. Copyright © 2015 Elsevier B.V. All rights reserved.

Skin bacterial flora as a potential risk factor predisposing to late bacterial infection after cross-linked hyaluronic acid gel augmentation.

PubMed

Netsvyetayeva, Irina; Marusza, Wojciech; Olszanski, Romuald; Szyller, Kamila; Krolak-Ulinska, Aneta; Swoboda-Kopec, Ewa; Sierdzinski, Janusz; Szymonski, Zachary; Mlynarczyk, Grazyna

2018-01-01

Cross-linked hyaluronic acid (HA) gel is widely used in esthetic medicine. Late bacterial infection (LBI) is a rare, but severe complication after HA augmentation. The aim of this study was to determine whether patients who underwent the HA injection procedure and developed LBI had qualitatively different bacterial flora on the skin compared to patients who underwent the procedure without any complications. The study group comprised 10 previously healthy women with recently diagnosed, untreated LBI after HA augmentation. The control group comprised 17 healthy women who had a similar amount of HA injected with no complications. To assess the difference between the two groups, their skin flora was cultured from nasal swabs, both before and after antibiotic treatment in the study group. A significant increase in the incidence of Staphylococcus epidermidis was detected in the control group ( P =0.000) compared to the study group. The study group showed a significantly higher incidence of Staphylococcus aureus ( P =0.005), Klebsiella pneumoniae ( P =0.006), Klebsiella oxytoca ( P =0.048), and Staphylococcus haemolyticus ( P =0.048) compared to the control group. The bacterial flora on the skin differed in patients with LBI from the control group. The control group's bacterial skin flora was dominated by S. epidermidis . Patients with LBI had a bacterial skin flora dominated by potentially pathogenic bacteria.

Antibiotic sensitivity pattern from pregnant women with urinary tract infection in Bangalore, India.

PubMed

Sibi, G; Kumari, Pinki; Kabungulundabungi, Neema

2014-09-01

To determine the antibacterial profile of pregnant women with urinaty tract infections and analyze the antibiotic sensitivity pattern for the effective treatment. A total of 395 urine samples from pregnant women with different gestational age were processed for the isolation of uropathogens and tested against eight groups of antibiotics namely penicillins, cephalosporins, fluoroquinolones, aminoglycosides, macrolides, lincosamides, glycopeptides and sulfonamides. A positive culture percentage of 46.6% was obtained with the highest urinary tract infection in third trimester gestational age. Among the uropathogens isolated, 85.6% were Gram negative and 14.4% were Gram positive with Escherichia coli as the predominant bacteria (43.9%) followed by Klebsiella oxytoca (19.4%) and Klebsiella pneumoniae (13.3%). Antibiotic sensitivity assay revealed that amikacin had the highest overall sensitivity (n=136; 76.7%) and the subsequent highest sensitivity was observed with ciprofloxacin (n=132; 73.3%), clindamycin (n=124; 68.9%), cefotaxime (n=117; 65%) and nalidixic acid (n=115; 63.9%). The findings revealed that uropathogens were more resistant to penicillins, macrolides and glycopeptides which restrict their use in treating urinaty tract infections during pregnancy. In conclusion, common causative bacteria and their antibiotic sensitivity pattern are to be determined along with their safety to mother and fetus for the effective treatment of urinary tract infections during pregnancy. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Alimentary Tract Bacteria Isolated and Identified with API-20E and Molecular Cloning Techniques from Australian Tropical Fruit Flies, Bactrocera cacuminata and B. tryoni

PubMed Central

Thaochan, N.; Drew, R. A. I.; Hughes, J. M.; Vijaysegaran, S.; Chinajariyawong, A.

2010-01-01

Bacteria were isolated from the crop and midgut of field collected Bactrocera cacuminata (Hering) and Bactrocera tryoni (Froggatt) (Diptera: Tephritidae). Two methods were used, firstly isolation onto two types of bacteriological culture media (PYEA and TSA) and identification using the API-20E diagnostic kit, and secondly, analysis of samples using the 16S rRNA gene molecular diagnostic method. Using the API-20E method, 10 genera and 17 species of bacteria in the family Enterobacteriaceae were identified from cultures growing on the nutrient agar. The dominant species in both the crop and midgut were Citrobacter freundii, Enterobacter cloacae and Klebsiella oxytoca. Providencia rettgeri, Klebsiella pneumoniae ssp ozaenae and Serratia marcescens were isolated from B. tryoni only. Using the molecular cloning technique that is based on 16S rRNA gene sequences, five bacteria classes were dignosed — Alpha-, Beta-, Gamma- and Delta- Proteobacteria and Firmicutes — including five families, Leuconostocaceae, Enterococcaceae, Acetobacteriaceae, Comamonadaceae and Enterobacteriaceae. The bacteria affiliated with Firmicutes were found mainly in the crop while the Gammaproteobacteria, especially the family Enterobacteriaceae, was dominant in the midgut. This paper presents results from the first known application of molecular cloning techniques to study bacteria within tephritid species and the first record of Firmicutes bacteria in these flies. PMID:20883132

Energy-Dependent Accumulation of Fluoroquinolones in Quinolone-Resistant Klebsiella pneumoniae Strains

PubMed Central

Martínez-Martínez, Luis; García, Isabel; Ballesta, Sofía; Benedí, Vicente Javier; Hernández-Allés, Santiago; Pascual, Alvaro

1998-01-01

The intracellular accumulation of norfloxacin and pefloxacin in Klebsiella pneumoniae was evaluated. The roles of lipopolysaccharide, capsule, and outer membrane proteins were not important for the intrabacterial accumulation of fluoroquinolones in isogenic strains with known outer membrane alterations. In fluoroquinolone-resistant clinical isolates also expressing GyrA alterations, an active efflux leading to decreased accumulation of the drugs enhanced their resistance to these agents. PMID:9661034

Effect of Hand Antisepsis Agent Selection and Population Characteristics on Surgical Site Infection Pathogens.

PubMed

Oriel, Brad S; Chen, Qi; Wong, Kevin; Itani, Kamal M F

Selection of a pre-operative hand antisepsis agent has not been studied in relation to surgical site infection (SSI) culture data. In our hospital, we introduced an alcohol-based hand rub (ABR) in 2012 as an alternative to traditional aqueous surgical scrubs (TSS). It was the goal of this study to review any effect of this implementation on SSI pathogen characteristics. In addition, we sought to compare our SSI culture data with available National Healthcare Safety Network (NHSN) data. We hypothesized that SSI pathogens and resistant isolates are affected by surgical hand antisepsis technique. Data collected prospectively between 2007 and 2014 were retrospectively analyzed for two time periods at the Veterans Affairs Boston Healthcare System (VABHS): Before ABR implementation (TSS group) and after (ABR group). Pathogen distribution and pathogenic isolate resistance profiles were compared for TSS and ABR, and similar comparisons, along with procedure-associated SSI comparisons, were made between VABHS and NHSN. All VABHS data were interpreted and categorized according to NHSN definitions. Compared with TSS (n = 4,051), ABR (n = 2,293) had a greater rate of Staphylococcus aureus (42.6% vs. 38.0%), Escherichia coli (12.8% vs. 9.9%), Pseudomonas aeruginosa (8.5% vs. 2.8%), and Enterobacter spp. (10.6% vs. 2.8%), and a lower rate of Klebsiella pneumoniae/K. oxytoca (4.3% vs. 8.5%) cultured from superficial and deep SSIs (p < 0.05). Of the S. aureus isolates, 35.0% and 44.4% were resistant to oxacillin/methicillin (MRSA) in ABR and TSS, respectively (p = 0.06). Looking at all SSIs, coagulase-negative staphylococci and K. pneumoniae/K. oxytoca at VABHS (4.0% and 10.4%, respectively) accounted for the biggest difference from NHSN (11.7% and 4.0%, respectively). Aside from MRSA, where there was no difference between VABHS and NHSN (42.9% vs. 43.7%, respectively; p = 0.87), statistically significant (p < 0.05) differences were observed among multi-drug-resistant K. pneumoniae/K. oxytoca (0% vs. 6.8%, respectively) and Escherichia coli (10.0% vs. 1.6%, respectively), as well as among extended-spectrum cephalosporin-resistant K. pneumoniae/K. oxytoca (4.8% vs. 13.2%, respectively) and Enterobacter (58.3% vs. 27.7%, respectively). VABHS had a greater proportion of SSIs in abdominal and vascular cases than did NHSN (48.6% vs. 22.5% and 13.2% vs. 1.5%, respectively). Overall, these differences were significant (p < 0.05). The TSS and ABR groups differed in the distribution of pathogens recovered. Those differences, along with SSI pathogen distribution, pathogenic isolate resistance profiles, and procedure-associated SSIs between VABHS and NHSN, warrant further investigation.

A new laboratory cultivation of Paramecium bursaria using non-pathogenic bacteria strains.

PubMed

Bator, Tomasz

2010-01-01

In most studies dealing with the laboratory cultivation of paramecia (Paramecium bursaria), Klebsiella pneumoniae bacteria are used to inoculate the medium. However, Klebsiella pneumoniae is a typical pathogen, and its use is always associated with a risk of infection. The aim of the present research was to examine non-pathogenic bacteria strains as components of the medium for Paramecium bursaria. The paramecia were incubated on lettuce infusions bacterized with different bacteria strains: Bacillus subtilis DSM 10, Bacillus megaterium DSM 32, Escherichia coli DSM 498, Micrococcus luteus DSM 348. A strain derived from the natural habitat of Paramecium bursaria was used as the control one. Experiments were conducted under constant light and in the dark. Paramecia cells were counted under a stereomicroscope on consecutive days of incubation. The obtained results show that the most intensive growth of Paramecium bursaria occurs in the presence of Escherichia coli DSM 498. The use of this strain as a component of the medium allows one to obtain a high number of ciliates regardless of the light conditions. It can be concluded that the Paramecium bursaria cultivation procedure can be modified by using the non-pathogenic bacteria strain Escherichia coli DSM 498 instead of Klebsiella pneumoniae.

Two T7-like Bacteriophages, K5-2 and K5-4, Each Encodes Two Capsule Depolymerases: Isolation and Functional Characterization.

PubMed

Hsieh, Pei-Fang; Lin, Hsiao-Hsuan; Lin, Tzu-Lung; Chen, Yi-Yin; Wang, Jin-Town

2017-07-04

Two Klebsiella bacteriophages K5-2 and K5-4, which are able to infect and grow on either capsular types K30/K69 and K5 or K8 and K5 of Klebsiella strains, were isolated and characterized. Each phage contained two open reading frames (ORFs), which encoded two putative capsule depolymerases, respectively. The first ORF encoded tail fiber proteins, which have K30/K69 depolymerase and K8 depolymerase activities. The second ORF encoded hypothetical proteins, which are almost identical in amino acid sequences, and have K5 depolymerase activity. Alcian blue staining of enzyme-treated capsular polysaccharides (CPS) showed that purified depolymerases can cleave purified Klebsiella CPS in vitro and liberate monosaccharaides. Capsule K5 deletion mutants were not lysed by either phage, suggesting that the capsule was essential for phage infection. Bacterial killing was observed when incubated Klebsiella strains with phages but not with purified depolymerases. Treatment with the K5-4 phage significantly increased the survival of mice infected with a K. pneumoniae K5 strain. In conclusion, two dual host-specific Klebsiella phages and their tailspikes exhibit capsule depolymerase activity were characterized. Each phage and phage-encoded depolymerase has specificity for capsular type K30/K69, K8 or K5, and could be used for the typing and treatment of K. pneumoniae infection.

Titres and cross reactions of commercial antisera for the capsular typing of Klebsiella species.

PubMed Central

Casewell, M W

1975-01-01

Ninety commercially supplied sera for the capsular typing of Klebsiella species were tested in a full chequerboard against 72 type strains. Only four of 144 homologous reactions could not be detected. Of the 6336 possible heterologous reactions, 91 actual cross reactions were found. All positive reactions were titrated and working dilutions deduced. This provides essential information for the successful typing of unknown strains with these sera. PMID:1091662

Comparison of chemical compositions and antimicrobial activities of essential oils from three conifer trees; Pinus densiflora, Cryptomeria japonica, and Chamaecyparis obtusa.

PubMed

Lee, Jeong-Ho; Lee, Byung-Kyu; Kim, Jong-Hee; Lee, Sang Hee; Hong, Soon-Kwang

2009-04-01

The chemical compositions, and antibacterial and antifungal effects of essential oils extracted from three coniferous species, Pinus densiflora, Cryptomeria japonica, and Chamaecyparis obtusa, were investigated. Gas chromatography mass analysis of the essential oils revealed that the major components and the percentage of each essential oil were 16.66% beta-phellandrene and 14.85% alpha-pinene in P. densiflora; 31.45% kaur-16-ene and 11.06% sabinene in C. japonica; and 18.75% bicyclo [2, 2, 1] heptan-2-ol and 17.41% 2-carene in Ch. obtusa. The antimicrobial assay by agar disc diffusion method showed that 2.2 microg of Ch. obtusa oil inhibited most effectively the growth of Escherichia coli ATCC 33312 and Klebsiella oxytoca ATCC 10031, whereas the C. japonica oil gave weak antimicrobial activity. The minimal inhibitory concentration (MIC) values for bacterial strains were in the range of 5.45-21.8 mg/ml depending on essential oils, but most Gram-negative bacteria were resistant even at 21.8 mg oil/ml. P. densiflora oil showed the most effective antifungal activity and the MIC values for Cryptococcus neoformans B42419 and Candida glabrata YFCC 062CCM 11658 were as low as 0.545 and 2.18 mg/ml, respectively. Cryp. neoformans B42419 was the most sensitive to all essential oils in the range of 0.545-2.18 mg/ml. Our data clearly showed that the essential oils from the three conifers had effective antimicrobial activity, especially against fungi.

Antimicrobial susceptibility pattern in diabetic foot ulcer: a pilot study.

PubMed

Sekhar, Sm; Vyas, N; Unnikrishnan, Mk; Rodrigues, Gs; Mukhopadhyay, C

2014-09-01

Diabetic foot infections (DFIs) are major public health problems and knowledge of microbes that cause infections are helpful to determine proper antibiotic therapy. The aim was to investigate the antimicrobial susceptibility pattern of microbes in DFIs. A cross-sectional study was conducted for a period of 6 months at the Department of General Surgery, KMC hospital, Manipal University, Manipal, India. During this period, 108 patients having DFIs admitted in the general surgery wards were tracked from the hospital data management system. These patients' pus samples were examined as Gram-stained smear and cultured aerobically on blood agar and MacConkey agar plates. Antimicrobial susceptibility test was performed by disc diffusion techniques according to Clinical and Laboratory Standards Institute guidelines. Of the 108 specimens of the diabetic foot lesions, culture showed polymicrobial growth in 44.4% (48/108). Prevalence of Gram-negative organisms (56%, 84/150) was found to be more than Gram-positive organisms (44%, 66/150). However, Staphylococcus aureus was the most frequent pathogen (28%, 42/150). All Gram-positive aerobes were sensitive to doxycycline. All Gram-negative isolates, including extended spectrum beta lactamase producing strains of Proteus mirabilis and Klebsiella oxytoca except Acinetobacter were highly sensitive to amikacin, cefoperazone/sulbactam, and meropenem. Acinetobacter was completely resistant to all the common antibiotics tested. Prevalence showed Gram-negative bacteria was slightly more than Gram-positive bacteria in diabetic foot ulcers. This study recommends doxycycline should be empirical treatment of choice for Gram-positive isolates and amikacin, cefoperazone/sulbactam, and meropenem should be considered for most of the Gram-negatives aerobes.

[Bile-resistant Gram-negative bacteria effect of different kinds of root decoction pieces].

PubMed

Deng, Yan; Wang, Ya-Ke; Han, Xiao-Yu; Wang, Ya-Qi; Jiang, Zhen-Yu; Yu, Zhi-Jun; Deng, Hai-Ying

2017-11-01

To investigate the microbial contamination in Chinese herbal decoction pieces with different functional types by studying the total aerobic microbial count (TAMC), and total yeast and mould count (TYMC) in 40 samples of 8 types of root decoction pieces; further evaluate the contamination load of bile-resistant Gram-negative bacteria, and identify the Gram-negative bacteria by using biochemical identification system for Gram-negative bacteria. Our results showed that the TAMC value was more than 1 000 CFU•g⁻¹ in 85% (34/40) samples, and was more than 100 CFU•g⁻¹ in 30% (12/40) samples; the contamination of bile-resistant Gram-negative bacteria was detected in 45% (18/40) of the samples. The bile-resistant Gram-negative bacteria load of seven batches of samples was N>1 000 MPN•g⁻¹. Sixteen bacterium strains including Serratia plymouthensis, Cedecea neteri, Escherichia vulneris, Klebsiella oxytoca, Enterobacter amnigenus, E. cloacae, E. sakazakii, Proteus penneri and E. gergoviae were obtained and identified. E. cloacae was the predominant bacterium that was isolated from Salviae Miltiorrhizae Radix et Rhizoma, while E. amnigenus, Yersinia pseudotuberculosis was the typical bacterium of Ophiopogonis Radix and Codonopsis Radix, respectively. All these suggested that the contamination of bile-resistant Gram-negative bacteria was severe for the root decoction pieces in Wuhan city. Microbial species have certain selection specificity for medicinal ingredients, so the type and limit of control bacteria for detection should be formulated according to the pollution type and quantity of bile-resistant Gram-negative bacteria. Copyright© by the Chinese Pharmaceutical Association.

Complete genome sequence of Klebsiella pneumoniae J1, a protein-based microbial flocculant-producing bacterium.

PubMed

Pang, Changlong; Li, Ang; Cui, Di; Yang, Jixian; Ma, Fang; Guo, Haijuan

2016-02-20

Klebsiella pneumoniae J1 is a Gram-negative strain, which belongs to a protein-based microbial flocculant-producing bacterium. However, little genetic information is known about this species. Here we carried out a whole-genome sequence analysis of this strain and report the complete genome sequence of this organism and its genetic basis for carbohydrate metabolism, capsule biosynthesis and transport system. Copyright © 2016 Elsevier B.V. All rights reserved.

Phenotypic and genotypic characterization of Klebsiella pneumonia recovered from nonhuman primates

USDA-ARS?s Scientific Manuscript database

Klebsiella pneumoniae is a zoonotic, Gram-negative member of the family Enterobacteriaceae and is the causative agent of nosocomial septicemic, pneumonic, and urinary tract infections. Recently, pathogenic strains of K. pneumoniae sharing a hypermucoviscosity (HMV) phenotype have been attributed to ...

[Molecular characterization of ESBL-producing Klebsiella pneumoniae isolates from intensive care patients].

PubMed

Chromá, Magdalena; Kolár, Milan; Marek, Oldrich; Koukalová, Dagmar; Sauer, Pavel

2007-10-01

The study aimed at the assessment of the prevalence of ESBL-positive isolates of Klebsiella pneumoniae in intensive care patients and their molecular biology analysis. Over a 5-month period, Klebsiella pneumoniae strains were isolated from patients hospitalized at the Department of Anaesthesiology and Resuscitation of the University Hospital in Olomouc. For each isolate, an antibiogram was performed by the standard microdilution method and the production of ESBL was determined by the modified double-disk synergy test. PCR was used to demonstrate the presence of the blaTEM and blaSHV genes. The isolates producing SHV- and TEM-types of beta-lactamases were typed using the restriction fragment length polymorphism (RFLP) method to identify the most common mutations responsible for the development of an ESBL phenotype. Similar or identical isolates were determined by pulsed-field gel electrophoresis (PFGE) of DNA fragments cleaved by the XbaI restriction endonuclease. A total of 67 isolates of Klebsiella pneumoniae were obtained. In 13 of them, the production of ESBL was detected and the presence of the blaSHV gene was confirmed by PCR. Restriction cleavage by NheI revealed mutations at position 238 in all SHV-positive PCR products. The restriction analysis did not confirm the presence of the gene encoding TEM-type extended-spectrum beta-lactamase. Molecular biology typing by PFGE detected the presence of 11 different strains. In the observed group of intensive care patients, the prevalence of ESBL-positive strains of Klebsiella pneumoniae reached 19.4 %. The analysis of SHV and TEM products of PCR by the RFLP method showed the prevalence of SHV-type ESBL. Overall, 84.6 % of the strains had unique restriction profiles. The results suggest both high levels of hygienic and epidemiological measures at the monitored department and rational antibiotic policy.

Significance of Fecal Coliform-Positive Klebsiella1

PubMed Central

Bagley, Susan T.; Seidler, Ramon J.

1977-01-01

A total of 191 Klebsiella pneumoniae isolates of human clinical, bovine mastitis, and a wide variety of environmental sources were tested for fecal coliform (FC) response with the membrane filtration and most probable number techniques. Twenty-seven Escherichia coli cultures of human clinical and environmental origins were also tested. Eighty-five percent (49/58) of known pathogenic K. pneumoniae were FC positive, compared with 16% (19/120) of the environmental strains. E. coli results indicated 93% (13/14) of the clinical and 85% (11/13) of the environmental strains as FC positive. There was no significant difference in the incidence of FC-positive cultures between pathogenic Klebsiella and E. coli. pH measurements of K. pneumoniae and E. coli cultures growing in m-FC broth at 44.5°C revealed three distinct pH ranges correlating with colony morphology. β-Galactosidase assays of Klebsiella and E. coli cultures at 44.5°C indicated all were able to hydrolyze lactose, even if they were FC negative by the membrane filtration or most probable number techniques. The FC response pattern appears stable in K. pneumoniae. Three pathogenic cultures showed no change in FC responses after 270 generations of growth in sterile pulp mill effluent. Since K. pneumoniae is carried in the gastrointestinal tract of humans and animals and 85% of the tested pathogenic strains were FC positive, the isolation of FC-positive Klebsiella organisms from the environment would indicate their fecal or clinical origin or both. The added fact that K. pneumoniae is an opportunistic pathogen of increasing importance makes the occurrence of FC-positive environmental Klebsiella, particularly in large numbers, a potential human and animal health hazard. PMID:18086

[Prostate histopathology of NIH category IV prostatitis detected by sextant prostate needle biopsy from the patients with high prostatic specific antigen].

PubMed

Shimomura, Tatsuya; Kiyota, Hiroshi; Takahashi, Hiroyuki; Madarame, Jun; Kimura, Takahiro; Onodera, Shouichi

2003-08-01

Asymptomatic prostatitis is classified as category IV in NIH classification of prostatitis syndrome (1999). No report concerning this category has been present. We investigated this category histopathologically and clinically, in order to clarify the histopathological distribution and its correlation to the clinical features, in this study. Among 785 patients who were suspected prostate cancer because of their high prostatic specific antigen (PSA) values and to have a sextant prostate needle biopsy was performed between January, 1996 and December, 2000, 88 patients (11.2%) were diagnosed as NIH category IV prostatitis (asymptomatic prostatitis). We observed all pathological specimens stained with Hematoxylin-Eosine, and classified them into subtypes according to the classification criteria for prostatitis defined by True et al. (1999). We also investigated the relationship between histopathological distribution and clinical features such as PSA values, PSA density, the incidence of pyuria or bacteriuria. In the histopathological study, grade distributions were 12.5% (11/88) in mild, 71.6% (63/88) in moderate, and 15.9% (14/88) in severe. Location distributions were 2.3% (2/88) in glandular, 68.2% (60/88) in periglandular, and 29.5% (26/88) in stromal. No relationship between these subtypes and clinical features was recognized statistically. However, 7 patients (7.95%) were diagnosed as prostate cancers, later. Pyuria was found in 29.1% (23/79). Bacteriuria was present in 14.3% (11/77). Isolated bacteria were 4 strains of Enterococcus faccalis, 2 strains of each of Pseudomonas aeruginosa and Staphylococcus aureus, and one strain of each of Escherichia coli, Klebsiella oxytoca, Enterobacter cloacae, Enterobacter aerogenes, Staphylococcus haemolyticus, and Staphylococcus epidermidis. Gram positive rod, and Candida sp. No relationship between these subtypes and bacterial species was recognized. These results indicated that the incidence of NIII category IV prostatits was not low without correlation to any clinical features. However, we should pay attention to the presence of prostate cancer, because a small number of the patients were diagnosed as prostate cancer, later.

Is candidiasis the true cause of vulvovaginal irritation in women with diabetes mellitus?

PubMed Central

Rowe, B R; Logan, M N; Farrell, I; Barnett, A H

1990-01-01

Vulvovaginitis is common in diabetic women and is often treated with antifungal agents on the assumption that the causative organism is Candida albicans. In a survey of 100 consecutive diabetic women attending a diabetes clinic 36 had complained to their general practitioner about vulvovaginal irritation during the past three years and 26 were treated with antifungal agents without a vaginal examination or swabs being taken. In a separate study 27 post-menopausal women with non-insulin dependent diabetes and symptoms of vulvovaginitis were investigated. The organisms cultured were: Candida albicans (n = 6), beta haemolytic streptococci (n = 14), Gardnerella vaginalis (n = 2), Staphylococcus aureus (n = 2), Streptococcus milleri (n = 1), Streptococcus faecalis (n = 1), Klebsiella oxytoca (n = 1), no organisms (n = 3). Where a bacterial organism was isolated symptoms resolved in all but one case with appropriate antibiotic treatment. It is recommended that the practice of initiating antifungal treatment without taking high vaginal swabs should be reviewed and treatment should be given specifically rather than empirically. PMID:2131794

Proteolytic interconversion and N-terminal sequences of the Citrobacter diversus major beta-lactamases.

PubMed Central

Franceschini, N; Amicosante, G; Perilli, M; Maccarrone, M; Oratore, A; van Beeumen, J; Frère, J M

1991-01-01

The N-terminal sequences of the two major beta-lactamases produced by Citrobacter diversus differed only by the absence of the first residue in form II and the loss of five amino acid residues at the C-terminal end. Limited proteolysis of the homogeneous form I protein yielded a variety of enzymatically active products. In the major product obtained after the action of papain, the first three N-terminal residues of form I had been cleaved, whereas at the C-terminal end the treated enzyme lacked five residues. However, this cannot explain the different behaviours of form I, form II and papain digestion product upon chromatofocusing. Form I, which was sequenced up to position 56, exhibited a very high degree of similarity with a Klebsiella oxytoca beta-lactamase. The determined sequence, which contained the active serine residue, demonstrated that the chromosome-encoded beta-lactamase of Citrobacter diversus belong to class A. Images Fig. 2. PMID:2039443

Is candidiasis the true cause of vulvovaginal irritation in women with diabetes mellitus?

PubMed

Rowe, B R; Logan, M N; Farrell, I; Barnett, A H

1990-08-01

Vulvovaginitis is common in diabetic women and is often treated with antifungal agents on the assumption that the causative organism is Candida albicans. In a survey of 100 consecutive diabetic women attending a diabetes clinic 36 had complained to their general practitioner about vulvovaginal irritation during the past three years and 26 were treated with antifungal agents without a vaginal examination or swabs being taken. In a separate study 27 post-menopausal women with non-insulin dependent diabetes and symptoms of vulvovaginitis were investigated. The organisms cultured were: Candida albicans (n = 6), beta haemolytic streptococci (n = 14), Gardnerella vaginalis (n = 2), Staphylococcus aureus (n = 2), Streptococcus milleri (n = 1), Streptococcus faecalis (n = 1), Klebsiella oxytoca (n = 1), no organisms (n = 3). Where a bacterial organism was isolated symptoms resolved in all but one case with appropriate antibiotic treatment. It is recommended that the practice of initiating antifungal treatment without taking high vaginal swabs should be reviewed and treatment should be given specifically rather than empirically.

Superinfections in herpes simplex keratitis.

PubMed

Boisjoly, H M; Pavan-Langston, D; Kenyon, K R; Baker, A S

1983-09-01

We reviewed 15 cases of culture-proven corneal superinfections in 15 patients (eight men and seven women ranging in age from 41 to 86 years) with recurrent herpes simplex keratitis. The factors that appeared to increase the risk of superinfection were the presence of an epithelial defect (found in all 15 cases), a history of recurrent herpetic keratouveitis (found in ten cases), and the use of topical corticosteroids (found in 13 cases). Eight of the 15 patients were taking antibiotics at the time the superinfections were diagnosed, indicating that topical antibiotics do not provide sufficient protection. Gram-negative rods were found in six cases (Proteus mirabilis, Pseudomonas aeruginosa, Serratia marcescens, Klebsiella oxytoca, Enterobacter cloacae, and Achromobacter sp.). Gram-positive organisms, often in association with another infecting agent, were found in six cases (Staphylococcus epidermidis, three cases; S. aureus, two cases; and Streptococcus sp., two cases). Fungal superinfections were found in three cases (Cephalosporium acremonium, Candida albicans, and Aspergillus fumigatus, one case each). Mycobacterium cheloni was found in two cases.

In Vitro Inhibition of Klebsiella pneumoniae by Lactobacillus delbrueckii Subsp. delbrueckii LDD01 (DSM 22106): An Innovative Strategy to Possibly Counteract Such Infections in Humans?

PubMed

Mogna, Luca; Deidda, Francesca; Nicola, Stefania; Amoruso, Angela; Del Piano, Mario; Mogna, Giovanni

To determine the in vitro antimicrobial activity of selected Lactobacillus strains isolated from the feces of healthy humans against Klebsiella pneumoniae. Klebsiella is ubiquitous in nature and may colonize the skin, the pharynx, or the gastrointestinal tract of humans. Despite the widespread use of antibiotic molecules with a broad spectrum in hospitalized patients, an increased overall load of klebsiellae as well as the subsequent development of multidrug-resistant strains able to synthesize extended-spectrum beta-lactamase have been registered. These strains are particularly virulent, express capsular-type K55, and have a considerable ability to propagate. The 4 strains Lactobacillus paracasei LPC01 (CNCM I-1390), Lactobacillus rhamnosus LR04 (DSM 16605), Bifidobacterium longum B2274 (DSM 24707), and Lactobacillus delbrueckii subsp. delbrueckii LDD01 (DSM 22106) were tested. The analysis was performed using both a disc-diffusion assay and the broth-dilution procedure, also including an evaluation of the supernatants obtained from a fresh broth culture of each bacterium. L. delbrueckii subsp. delbrueckii LDD01 demonstrated the best inhibitory results among all the tested strains. The antibacterial activity of the supernatant was retained even after treatment with α-amylase and neutralization with NaOH 1N, thus suggesting the protein structure of the inhibitory molecule. In contrast, it was completely lost after treatment with proteinase K. Overall results suggest that the inhibitory effect of L. delbrueckii subsp. delbrueckii LDD01 should be attributed to the production of a bacteriocin. This strain may be prospectively useful for strengthening probiotic formulations and possibly counteract infections by K. pneumoniae in humans.

Antimicrobial susceptibility of Gram-negative bacteria causing intra-abdominal infections in China: SMART China 2011.

PubMed

Zhang, Hui; Yang, Qiwen; Xiao, Meng; Chen, Minjun; Badal, Robert E; Xu, Yingchun

2014-01-01

The Study for Monitoring Antimicrobial Resistance Trends program monitors the activity of antibiotics against aerobic and facultative Gram-negative bacilli (GNBs) from intra-abdominal infections (IAIs) in patients worldwide. In 2011, 1 929 aerobic and facultative GNBs from 21 hospitals in 16 cities in China were collected. All isolates were tested using a panel of 12 antimicrobial agents, and susceptibility was determined following the Clinical Laboratory Standards Institute guidelines. Among the Gram-negative pathogens causing IAIs, Escherichia coli (47.3%) was the most commonly isolated, followed by Klebsiella pneumoniae (17.2%), Pseudomonas aeruginosa (10.1%), and Acinetobacter baumannii (8.3%). Enterobacteriaceae comprised 78.8% (1521/1929) of the total isolates. Among the antimicrobial agents tested, ertapenem and imipenem were the most active agents against Enterobacteriaceae, with susceptibility rates of 95.1% and 94.4%, followed by amikacin (93.9%) and piperacillin/tazobactam (87.7%). Susceptibility rates of ceftriaxone, cefotaxime, ceftazidime, and cefepime against Enterobacteriaceae were 38.3%, 38.3%, 61.1%, and 50.8%, respectively. The leastactive agent against Enterobacteriaceae was ampicillin/sulbactam (25.9%). The extended-spectrum β-lactamase (ESBL) rates among E. coli, K. pneumoniae, Klebsiella oxytoca, and Proteus mirabilis were 68.8%, 38.1%, 41.2%, and 57.7%, respectively. Enterobacteriaceae were the major pathogens causing IAIs, and the most active agents against the study isolates (including those producing ESBLs) were ertapenem, imipenem, and amikacin. Including the carbapenems, most agents exhibited reduced susceptibility against ESBL-positive and multidrug-resistant isolates.

[Extended-spectrum beta-lactamase detection in Enterobacteriaceae and antibiotic susceptibility analysis].

PubMed

Cao, Wei; Tong, Ming-hua; Wang, Ji-gui

2002-02-28

To detect the extended-spectrum beta-lactamases (ESBLs) in family Enterobacteriaceae and analyze the antibiotic susceptibility of those ESBLs-producing strains. ESBLs were determined by the double-disk confirmatory test and 8 antibiotic susceptibilities were tested with the disk disffusion method in those strains producing ESBLs. Forty-seven ESBLs-producing strains comprised of 25 of E. coli, 14 of K. pneumoniae, 5 of E. cloacae, 1 of K. oxytoca, 1 of K. rhinoscleromatis, and 1 of S. liquefaciens. The susceptibility rates of those strains were: 100% for imipenem and meropenem, 89.4% for piperacillin/tazobactam, 72.4% for cefoxitin and 65.9% for cefotetan. E. coli and K. pneumoniae are the prime strains producing ESBLs in Enterobacteriaceae. Imipenem and meropenem are the best drugs to deal with those ESBLs-producing strains. Piperacillin/tazobactam is better than cephamycins and other beta-lactama/beta-lactamase inhibitor combination.

Carbapenem resistance confers to Klebsiella pneumoniae strains an enhanced ability to induce infection and cell death in epithelial tissue-specific in vitro models.

PubMed

Leone, Laura; Raffa, Salvatore; Martinelli, Daniela; Torrisi, Maria Rosaria; Santino, Iolanda

2015-01-01

Carbapenem-resistant Klebsiella pneumoniae strains (KPC-Kp) are emerging worldwide causing different nosocomial infections including those of the urinary tract, lung or skin wounds. For these strains, the antibiotic treatment is limited to only few choices including colistin, whose continuous use led to the emergence of carbapenem-resistant KPC-Kp strains resistant also to this treatment (KPC-Kp Col-R). Very little is known about the capacity of the different strains of KPC-Kp to invade the epithelial cells in vitro. To verify if the acquisition of carbapenem-resistant and the colistin-resistant phenotypes are correlated with a different ability to infect a series of epithelial cell lines of various tissutal origin and with a different capacity to induce cellular death. We used Klebsiella pneumoniae (KP), KPC-Kp and KPC-Kp Col-R strains, isolated from different patients carrying various tissue-specific infections, to infect a series of epithelial cell lines of different tissutal origin. The invasive capacity of the strains and the extent and characteristics of the cell damage and death induced by the bacteria were evaluated and compared. Our results show that both KPC-Kp and KPC-Kp Col-R display a greater ability to infect the epithelial cells, with respect to KP, and that the bacterial cell invasion results in a nonprogrammed cell death.

In Vitro Activity of Imipenem against Carbapenemase-Positive Enterobacteriaceae Isolates Collected by the SMART Global Surveillance Program from 2008 to 2014

PubMed Central

Karlowsky, James A.; Kazmierczak, Krystyna M.; Badal, Robert E.; Young, Katherine; Motyl, Mary R.; Sahm, Daniel F.

2017-01-01

ABSTRACT The Study for Monitoring Antimicrobial Resistance Trends (SMART) global surveillance program collected 103,960 isolates of Enterobacteriaceae from 2008 to 2014. From this isolate collection, all ertapenem-nonsusceptible isolates (MIC, ≥1 μg/ml; n = 3,428) and 9,371 isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, and Proteus mirabilis with an ertapenem-susceptible extended-spectrum-β-lactamase (ESBL)-positive phenotype were assessed for the presence of common carbapenemase genes using a Check-MDR CT101 microarray (Check-Points, Wageningen, the Netherlands) and published multiplex PCR assays. Testing identified 1,493 isolates that harbored a carbapenemase gene (1,485 ertapenem-nonsusceptible isolates and 8 ertapenem-susceptible ESBL-positive isolates) and accounted for 1.4% (1,493/103,960) of all isolates of Enterobacteriaceae. The most frequently identified carbapenemase genes were the KPC (n = 794), OXA-48-like (n = 300), and NDM (n = 290) genes. Carbapenemase genes were most frequently identified in Klebsiella pneumoniae (n = 1,127), Escherichia coli (n = 149), and Enterobacter cloacae (n = 110). Among the carbapenemase-positive isolates, 66.7% (2/3), 37.0% (111/300), 20.0% (8/40), 3.3% (3/92), 2.3% (18/794), and 0% (0/290) of the isolates with genes for GES, OXA-48-like, IMP, VIM, KPC, and NDM, respectively, were susceptible to imipenem (MIC, ≤1 μg/ml). Isolates that tested as susceptible to imipenem were not uncommon among carbapenemase-positive isolates (9.4%, 141/1,493) and most frequently carried OXA-48-like enzymes (78.7%; 111/141); however, overall, these isolates remained rare (0.1%, 141/103,960). The practice of screening clinical isolates of Enterobacteriaceae that test as susceptible to carbapenems in vitro for the presence of carbapenemase genes remains controversial and requires further study. PMID:28298454

In Vitro Activity of Imipenem against Carbapenemase-Positive Enterobacteriaceae Isolates Collected by the SMART Global Surveillance Program from 2008 to 2014.

PubMed

Karlowsky, James A; Lob, Sibylle H; Kazmierczak, Krystyna M; Badal, Robert E; Young, Katherine; Motyl, Mary R; Sahm, Daniel F

2017-06-01

The Study for Monitoring Antimicrobial Resistance Trends (SMART) global surveillance program collected 103,960 isolates of Enterobacteriaceae from 2008 to 2014. From this isolate collection, all ertapenem-nonsusceptible isolates (MIC, ≥1 μg/ml; n = 3,428) and 9,371 isolates of Escherichia coli , Klebsiella pneumoniae , Klebsiella oxytoca , and Proteus mirabilis with an ertapenem-susceptible extended-spectrum-β-lactamase (ESBL)-positive phenotype were assessed for the presence of common carbapenemase genes using a Check-MDR CT101 microarray (Check-Points, Wageningen, the Netherlands) and published multiplex PCR assays. Testing identified 1,493 isolates that harbored a carbapenemase gene (1,485 ertapenem-nonsusceptible isolates and 8 ertapenem-susceptible ESBL-positive isolates) and accounted for 1.4% (1,493/103,960) of all isolates of Enterobacteriaceae The most frequently identified carbapenemase genes were the KPC ( n = 794), OXA-48-like ( n = 300), and NDM ( n = 290) genes. Carbapenemase genes were most frequently identified in Klebsiella pneumoniae ( n = 1,127), Escherichia coli ( n = 149), and Enterobacter cloacae ( n = 110). Among the carbapenemase-positive isolates, 66.7% (2/3), 37.0% (111/300), 20.0% (8/40), 3.3% (3/92), 2.3% (18/794), and 0% (0/290) of the isolates with genes for GES, OXA-48-like, IMP, VIM, KPC, and NDM, respectively, were susceptible to imipenem (MIC, ≤1 μg/ml). Isolates that tested as susceptible to imipenem were not uncommon among carbapenemase-positive isolates (9.4%, 141/1,493) and most frequently carried OXA-48-like enzymes (78.7%; 111/141); however, overall, these isolates remained rare (0.1%, 141/103,960). The practice of screening clinical isolates of Enterobacteriaceae that test as susceptible to carbapenems in vitro for the presence of carbapenemase genes remains controversial and requires further study. Copyright © 2017 American Society for Microbiology.

Draft Genome Sequence of a Multidrug-Resistant Klebsiella quasipneumoniae subsp. similipneumoniae Isolate from a Clinical Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozer, Egon A.; Morris, Andrew R.; Krapp, Fiorella

We report here the draft genome sequence of a multidrug-resistant clinical isolate ofKlebsiella quasipneumoniaesubsp.similipneumoniae, KP_Z4175. This strain, isolated as part of a hospital infection-control screening program, is resistant to multiple β-lactam antibiotics, aminoglycosides, and trimethoprim-sulfamethoxazole.

Intrinsic Klebsiella pneumoniae contamination of liquid germicidal hand soap containing chlorhexidine.

PubMed

Brooks, Steven E; Walczak, Mary A; Malcolm, Sharon; Hameed, Rizwanullah

2004-10-01

We describe intrinsic contamination with Klebsiella pneumoniae occurring during the manufacture of germicidal hand soap, labeled as containing 2% chlorhexidine, used throughout a 350-bed community medical center. A 3-year retrospective study failed to find evidence of increased incidence of clinical isolates of this strain.

[Post-marketing surveillance of antibacterial activities of cefozopran against various clinical isolates--II. Gram-negative bacteria].

PubMed

Igari, Jun; Oguri, Toyoko; Hiramatsu, Nobuyoshi; Akiyama, Kazumitsu; Koyama, Tsuneo

2003-10-01

As a post-marketing surveillance, the in vitro antibacterial activities of cefozopran (CZOP), an agent of cephems, against various clinical isolates were yearly evaluated and compared with those of other cephems, oxacephems, carbapenems, monobactams, and penicillins. Changes in CZOP susceptibility among bacteria were also evaluated with the bacterial resistance ratio calculated from the breakpoint MIC. Twenty-five species (4,154 strains) of Gram-negative bacteria were isolated from the clinical materials annually collected from 1996 to 2001, and consisted of Moraxella (Branhamella) catarrhalis, Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Enterobacter aerogenes, Serratia marcescens, Serratia liquefaciens, Citrobacter freundii, Citrobacter koseri, Proteus mirabilis, Proteus vulgaris, Morganella morganii, Providencia spp., Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas putida, Acinetobacter baumannii, Acinetobacter Iwoffii, Burkholderia cepacia, Stenotrophomonas maltophilia, Bacteroides fragilis group, and Prevotella/Porphyromonas. CZOP preserved its antibacterial activity against M. (B.) catarrhalis (MIC90: 4 micrograms/mL) and showed comparable activity to carbapenems against H. influenzae (MIC90: 1 microgram/mL). The antibacterial activity of CZOP against E. coli was preferable (MIC90: 0.125 microgram/mL) and comparable to those of cefpirome (CPR), cefepime (CFPM), and imipenem (IPM). The MIC90 of CZOP against K. pneumoniae and K. oxytoca was 1 and 0.25 microgram/mL, respectively. The MIC90 of CZOP against E. cloacae increased during 6 years (32 to 128 micrograms/mL). The antibacterial activity of CZOP against E. aerogenes was preferable (MIC90: 1 microgram/mL). The antibacterial activities of CZOP against S. marcescens and S. liquefaciens were relatively potent (MIC90: 0.5 and 0.25 microgram/mL) and comparable to those of CPR, CFPM, and carumonam. CZOP preserved comparable antibacterial activity to CPR against C. freundii and C. koseri (MIC90: 8 and 0.125 micrograms/mL). The MIC90 of CZOP against P. mirabilis, P. vulgaris, and M. morganii was 0.25, 16, and 2 micrograms/mL, respectively. The antibacterial activity of CZOP against Providencia spp. was moderate (MIC90: 64 micrograms/mL). The antibacterial activity of CZOP against P. aeruginosa was the most potent (MIC90: 16 micrograms/mL) among the test agents and comparable to those CFPM, IPM, and MEPM. CZOP had low activity against P. fluorescens and P. putida (MIC90: 128 micrograms/mL). The antibacterial activity of CZOP against A. baumannii was comparable to those of ceftazidime (CAZ), CPR and CFPM (MIC90: 32 micrograms/mL) and against A. lwoffii was moderate (MIC90: 64 micrograms/mL). Most of the test agents including CZOP had low antibacterial activity against B. cepacia, S. maltophilia, and B. fragilis group. The MIC90 of CZOP against Prevotella/Porphyromonas was 64 micrograms/mL. Bacterial cross-resistance ratio between CZOP and other agents was low in most of the species, ranging from 0.0 to 15.1%. In non-glucose fermentative bacteria, however, the bacterial cross-resistance ratio between CZOP and CFPM, CAZ, CPR, or IPM was high, being 36.8%, 28.0%, 38.7%, or 31.1%, respectively. In conclusion, the 6-year duration study suggested that the antibacterial activity of CZOP against E. cloacae possible decreased, but against other Gram-negative bacteria was consistent with the study results obtained until the new drug application approval.

[Phenotypic variations of susceptibility in Klebsiella pneumoniae strains of nosocomial origin and their association with biofilm formation].

PubMed

Barreto, Silvio; Zambrano, María; Araque, María

2009-06-01

Klebsiella pneumoniae is the principal opportunist pathogen associated with nosocomial infections. The morbidity and mortality produced by this microorganism is related mostly to antimicrobial resistance and its capacity to form biofilms. In this study, the phenotypic variations of susceptibility in 50 Klebsiella pneumoniae strains (26 betaLEE-producer and 24 no betaLEE-producer) isolated from pediatric patients with nosocomial septicemia at the High-risk Neonatal Unit of the Instituto Aut6nomo Hospital Universitario de Los Andes, Mérida, Venezuela and their associations with biofilm formation were analyzed. These strains were biochemically identified by standard microbiology methods. Antimicrobial susceptibility was determined by minimal inhibitory concentration and biofilm formation was detected by spectrophotometric techniques. Most of betaLEE strains were frequently associated with resistance markers such as tobramycin, kanamycin, tetracycline, chloramphenicol (38% each), streptomycin (36%) and netilmicin (34%). The predominant multiresistent phenotype was composed of betaLEE+ -AMG-TET-CLF (30%). 18% of K. pneumoniae strains were sensible to the antibiotics tested. Formation of biofilm was observed in 77.8% and 96.2% of sensible and resistent strains, respectively. There was no statistic relation between phenotipic variations of susceptibility and biofilm formation (p > = 0.05). However, both characteristics of K. pneumoniae should be evaluated to determine the therapeutic conduct to treat patients with nosocomial infection.

[Isolation of a carbapenem-resistant K1 serotype Klebsiella pneumonia strain and the study of resistance mechanism].

PubMed

Zhang, Rong; Wang, Xuan; Lü, Jianxin

2014-12-16

To study the virulence and mechanism of carbapenem resistance of a clinical isolate of carbapenem-resistant K1 serotype Klebsiella pneumonia strain. Identification of isolate was carried out with VITEK-2 compact system. Antimicrobial susceptibility was determined by E-test; Metallo β-lactamases and carbapenemases screening were conducted by imipenem-EDTA double disc synergy test and modified Hodge test, respectively.Specific polymerehse chain reaction (PCR) and DNA sequencing were preformed to detect the virulence genes including K1, K2, K5, K20, K54, K57, magA, rmpA, wcaG and a series of β-lactamase resistence genes. Conjunction experiment was also performed. The plasmids of transconjugants were submitted to PCR-based replicon typing (PBRT) method. Molecular typing was performed by multilocus sequence typing (MLST). Antimicrobial susceptibility testing revealed that the Klebsiella pneumonia strain was resistant to most of the antibiotics used in clinic. Phynotype confirmary rest revealed the production of carbapanemases, while Metallo β-lactamases were negative; PCR and DNA sequencing confirmed the isolate was positive for blaKPC-2, blaCTX-M-15, blaTEM-1, blaSHV-1 and virulence genes K1, magA, rmpA, wcaG simultaneously; blaKPC-2 was transferred from donor to Escherichia EC600 by conjunction experiment, while no virulence genes were found in the transconjugants. PBRT revealed that Frep plasmid was found in transconjugants. MLST analysis revealed that this strain belonged to ST23. K1 serotype Klebsiella pneumonia strain carries virulence genes and carbapenem resistance gene blaKPC-2, noteworthily the carbapenem resistance genes can be transferred through horizontal transmission on plasmids.

Plasmid-encoded amikacin resistance in multiresistant strains of Klebsiella pneumoniae isolated from neonates with meningitis.

PubMed Central

Woloj, M; Tolmasky, M E; Roberts, M C; Crosa, J H

1986-01-01

Two multiresistant Klebsiella pneumoniae strains isolated from cerebrospinal fluid of human neonates were analyzed for their plasmid content. Two of the plasmids harbored by these strains, pJHCMW1 (11 kilobase pairs) and pJHCMW4 (75 kilobase pairs), carried genetic determinants for amikacin resistance. These plasmids also encoded resistance to kanamycin, tobramycin, and ampicillin which could be transferred to Escherichia coli by conjugation. Extracts from transconjugant derivatives carrying pJHCMW4 produced an acetyltransferase activity that acetylated all three aminoglycosides. Transconjugant derivatives carrying pJHCMW1 encoded both acetylating and phosphorylating activities. Southern blot hybridization analysis indicated considerable DNA homology between these two plasmids. Images PMID:3521478

Phylogenetic Analysis of Klebsiella pneumoniae from Hospitalized Children, Pakistan.

PubMed

Ejaz, Hasan; Wang, Nancy; Wilksch, Jonathan J; Page, Andrew J; Cao, Hanwei; Gujaran, Shruti; Keane, Jacqueline A; Lithgow, Trevor; Ul-Haq, Ikram; Dougan, Gordon; Strugnell, Richard A; Heinz, Eva

2017-11-01

Klebsiella pneumoniae shows increasing emergence of multidrug-resistant lineages, including strains resistant to all available antimicrobial drugs. We conducted whole-genome sequencing of 178 highly drug-resistant isolates from a tertiary hospital in Lahore, Pakistan. Phylogenetic analyses to place these isolates into global context demonstrate the expansion of multiple independent lineages, including K. quasipneumoniae.

International Spread and Persistence of TEM-24 Is Caused by the Confluence of Highly Penetrating Enterobacteriaceae Clones and an IncA/C2 Plasmid Containing Tn1696::Tn1 and IS5075-Tn21▿

PubMed Central

Novais, Ângela; Baquero, Fernando; Machado, Elisabete; Cantón, Rafael; Peixe, Luísa; Coque, Teresa M.

2010-01-01

TEM-24 remains one of the most widespread TEM-type extended-spectrum β-lactamases (ESBLs) among Enterobacteriaceae. To analyze the reasons influencing its spread and persistence, a multilevel population genetics study was carried out on 28 representative TEM-24 producers from Belgium, France, Portugal, and Spain (13 Enterobacter aerogenes isolates, 6 Escherichia coli isolates, 6 Klebsiella pneumoniae isolates, 2 Proteus mirabilis isolates, and 1 Klebsiella oxytoca isolate, from 1998 to 2004). Clonal relatedness (XbaI pulsed-field gel electrophoresis [PFGE] and E. coli phylogroups) and antibiotic susceptibility were determined by standard procedures. Plasmid analysis included determination of the incompatibility group (by PCR, hybridization, and/or sequencing) and comparison of restriction fragment length polymorphism (RFLP) patterns. Characterization of genetic elements conferring antibiotic resistance included integrons (classes 1, 2, and 3) and transposons (Tn3, Tn21, and Tn402). Similar PFGE patterns were identified among E. aerogenes, K. pneumoniae, and P. mirabilis isolates, while E. coli strains were diverse (phylogenetic groups A, B2, and D). Highly related 180-kb IncA/C2 plasmids conferring resistance to kanamycin, tobramycin, chloramphenicol, trimethoprim, and sulfonamides were identified. Each plasmid contained defective In0-Tn402 (dfrA1-aadA1, aacA4, or aacA4-aacC1-orfE-aadA2-cmlA1) and In4-Tn402 (aacA4 or dfrA1-aadA1) variants. These integrons were located within Tn21, Tn1696, or hybrids of these transposons, with IS5075 interrupting their IRtnp and IRmer. In all cases, blaTEM-24 was part of an IS5075-ΔTn1 transposon within tnp1696, mimicking other genetic elements containing blaTEM-2 and blaTEM-3 variants. The international dissemination of TEM-24 is fuelled by an IncA/C2 plasmid acquired by different enterobacterial clones which seem to evolve by gaining diverse genetic elements. This work highlights the risks of a confluence between highly penetrating clones and highly promiscuous plasmids in the spread of antibiotic resistance, and it contributes to the elucidation of the origin and evolution of TEM-2 ESBL derivatives. PMID:19995930

In vitro activity of Ceftaroline against bacterial pathogens isolated from patients with skin and soft tissue and respiratory tract infections in African and Middle Eastern countries: AWARE global surveillance program 2012-2014.

PubMed

Karlowsky, James A; Biedenbach, Douglas J; Bouchillon, Samuel K; Hackel, Meredith; Iaconis, Joseph P; Sahm, Daniel F

2016-10-01

The objective of this report was to document antimicrobial susceptibility testing surveillance data for ceftaroline and comparative agents from the AWARE (Assessing Worldwide Antimicrobial Resistance Evaluation) global surveillance program for bacterial pathogens causing skin and soft tissue and respiratory tract infections in African and Middle Eastern countries from 2012 through 2014. Pathogen identities were confirmed by MALDI-TOF and antimicrobial susceptibility testing performed by CLSI broth microdilution methodology in a central laboratory. All methicillin-susceptible Staphylococcus aureus (MSSA) (n= 923; MIC90, 0.25 μg/mL) and 91.8% of methicillin-resistant S. aureus (MRSA) (n= 1161; MIC90, 1 μg/mL) tested were susceptible to ceftaroline. The maximum ceftaroline MIC observed for isolates of MRSA was 2 μg/mL. All Streptococcus pyogenes (n= 174; MIC90, 0.008 μg/mL), Streptococcus agalactiae (n= 44; MIC90, 0.015 μg/mL), Streptococcus pneumoniae (n= 351; MIC90, 0.25 μg/mL), and Haemophilus influenzae (n= 84; MIC90, ≤0.015 μg/mL) were susceptible to ceftaroline. Rates of susceptibility to ceftaroline among ESBL-negative Escherichia coli (n= 338), Klebsiella pneumoniae (n= 241), and Klebsiella oxytoca (n= 97) were 89.1% (MIC90, 1 μg/mL), 94.2% (MIC90, 0.5 μg/mL), and 99.0% (MIC90, 0.5 μg/mL), respectively. Copyright © 2016. Published by Elsevier Inc.

Metal-dependent function of a mammalian acireductone dioxygenase

PubMed Central

Deshpande, Aditi R.; Wagenpfeil, Karina; Pochapsky, Thomas C.; Petsko, Gregory A.; Ringe, Dagmar

2017-01-01

The two acireductone dioxygenase (ARD) isozymes from the methionine salvage pathway of Klebsiella oxytoca are the only known pair of naturally occurring metalloenzymes with distinct chemical and physical properties determined solely by the identity of the divalent transition metal ion (Fe2+ or Ni2+) in the active site. We now show that this dual chemistry can also occur in mammals. ARD from Mus musculus (MmARD) was studied to relate metal ion identity and three-dimensional structure to enzyme function. The iron-containing isozyme catalyzes the cleavage of 1,2-dihydroxy-3-keto-5-(thiomethyl)pent-1-ene (acireductone) by O2 to formate and the ketoacid precursor of methionine, the penultimate step in methionine salvage. The nickel bound form of ARD catalyzes an off-pathway reaction resulting in formate, carbon monoxide (CO) and 5-(thiomethyl) propionate. Recombinant MmARD was expressed and purified to obtain a homogeneous enzyme with a single transition metal ion bound. The Fe2+ bound protein, which shows about ten-fold higher activity than others, catalyzes on-pathway chemistry, whereas the Ni2+, Co2+ or Mn2+ forms exhibit off-pathway chemistry, as has been seen with ARD from Klebsiella. Thermal stability of the isozymes is strongly affected by metal ion identity, with Ni2+ bound MmARD being the most stable followed by Co2+ and Fe2+, and Mn2+-bound ARD being the least stable. Ni2+ and Co2+ bound MmARD were crystallized and the structures of the two proteins found to be similar. Enzyme-ligand complexes provide insight into substrate binding, metal coordination and catalytic mechanism. PMID:26858196

Phylogenetic Analysis of Klebsiella pneumoniae from Hospitalized Children, Pakistan

PubMed Central

Ejaz, Hasan; Wang, Nancy; Wilksch, Jonathan J.; Page, Andrew J.; Cao, Hanwei; Gujaran, Shruti; Keane, Jacqueline A.; Lithgow, Trevor; ul-Haq, Ikram; Dougan, Gordon

2017-01-01

Klebsiella pneumoniae shows increasing emergence of multidrug-resistant lineages, including strains resistant to all available antimicrobial drugs. We conducted whole-genome sequencing of 178 highly drug-resistant isolates from a tertiary hospital in Lahore, Pakistan. Phylogenetic analyses to place these isolates into global context demonstrate the expansion of multiple independent lineages, including K. quasipneumoniae. PMID:29048298

Genomic and transcriptomic analysis of NDM-1 Klebsiella pneumoniae in spaceflight reveal mechanisms underlying environmental adaptability

PubMed Central

Li, Jia; Liu, Fei; Wang, Qi; Ge, Pupu; Woo, Patrick C. Y.; Yan, Jinghua; Zhao, Yanlin; Gao, George F.; Liu, Cui Hua; Liu, Changting

2014-01-01

The emergence and rapid spread of New Delhi Metallo-beta-lactamase-1 (NDM-1)-producing Klebsiella pneumoniae strains has caused a great concern worldwide. To better understand the mechanisms underlying environmental adaptation of those highly drug-resistant K. pneumoniae strains, we took advantage of the China's Shenzhou 10 spacecraft mission to conduct comparative genomic and transcriptomic analysis of a NDM-1 K. pneumoniae strain (ATCC BAA-2146) being cultivated under different conditions. The samples were recovered from semisolid medium placed on the ground (D strain), in simulated space condition (M strain), or in Shenzhou 10 spacecraft (T strain) for analysis. Our data revealed multiple variations underlying pathogen adaptation into different environments in terms of changes in morphology, H2O2 tolerance and biofilm formation ability, genomic stability and regulation of metabolic pathways. Additionally, we found a few non-coding RNAs to be differentially regulated. The results are helpful for better understanding the adaptive mechanisms of drug-resistant bacterial pathogens. PMID:25163721

Klebsiella pneumoniae: Going on the Offense with a Strong Defense

PubMed Central

Paczosa, Michelle K.

2016-01-01

SUMMARY Klebsiella pneumoniae causes a wide range of infections, including pneumonias, urinary tract infections, bacteremias, and liver abscesses. Historically, K. pneumoniae has caused serious infection primarily in immunocompromised individuals, but the recent emergence and spread of hypervirulent strains have broadened the number of people susceptible to infections to include those who are healthy and immunosufficient. Furthermore, K. pneumoniae strains have become increasingly resistant to antibiotics, rendering infection by these strains very challenging to treat. The emergence of hypervirulent and antibiotic-resistant strains has driven a number of recent studies. Work has described the worldwide spread of one drug-resistant strain and a host defense axis, interleukin-17 (IL-17), that is important for controlling infection. Four factors, capsule, lipopolysaccharide, fimbriae, and siderophores, have been well studied and are important for virulence in at least one infection model. Several other factors have been less well characterized but are also important in at least one infection model. However, there is a significant amount of heterogeneity in K. pneumoniae strains, and not every factor plays the same critical role in all virulent Klebsiella strains. Recent studies have identified additional K. pneumoniae virulence factors and led to more insights about factors important for the growth of this pathogen at a variety of tissue sites. Many of these genes encode proteins that function in metabolism and the regulation of transcription. However, much work is left to be done in characterizing these newly discovered factors, understanding how infections differ between healthy and immunocompromised patients, and identifying attractive bacterial or host targets for treating these infections. PMID:27307579

Antibiotic resistance ofKlebsiella pneumoniae through β-arrestin recruitment-induced β-lactamase signaling pathway.

PubMed

Wei, Jiang; Wenjie, Yang; Ping, Liu; Na, Wang; Haixia, Ren; Xuequn, Zhao

2018-03-01

Overuse and misuse of antibiotics leads to rapid evolution of antibiotic-resistant bacteria and antibiotic resistance genes. Klebsiella pneumoniae has become the most common pathogenic bacterium accountable for nosocomial infections due to its high virulence factor and general occurrence of resistance to most antibiotics. The β-lactamase signaling pathway has been suggested to be involved in antibiotic resistance against β-lactams in Klebsiella pneumoniae . In the present study, the molecular mechanism of the antibiotic resistance of Klebsiella pneumoniae was investigated and the results indicated involvement of the β-arrestin recruitment-induced β-lactamase signaling pathway. Antimicrobial susceptibility of Klebsiella pneumoniae was assessed using automated systems and extended-spectrum β-lactamase (ESBL) and β-arrestin expression levels in Klebsiella pneumoniae were analyzed by reverse-transcription quantitative PCR. β-lactam resistance in Klebsiella pneumoniae was determined using β-lactam agar screening plates. The results demonstrated that β-arrestin recruitment was increased in Klebsiella pneumoniae with antibiotic resistance (AR- K.P .) compared with that in the native Klebsiella pneumoniae strain (NB- K.P .). Increased production of ESBL was observed in AR- K.P . after treatment with the β-lactam penicillin. Of note, inhibition of β-arrestin recruitment significantly suppressed ESBL expression in AR- K.P . and in addition, genes encoding β-arrestin and ESBL were upregulated in Klebsiella pneumoniae . Restoration of endogenous β-arrestin markedly increased antibiotic resistance of Klebsiella pneumoniae to β-lactam. Knockdown of endogenous β-arrestin downregulated antibiotic resistance genes and promoted the inhibitory effects of β-lactam antibiotic treatment on Klebsiella pneumoniae growth. In conclusion, the present study identified that β-arrestin recruitment was associated with growth and resistance to β-lactams, which suggested that β-arrestin regulating ESBL expression may be a potential target for addressing antibiotic resistance to β-lactams in Klebsiella pneumoniae .

Biodegradation of sodium lauryl ether sulfate (SLES) by two different bacterial consortia.

PubMed

Khleifat, Khaled M

2006-11-01

Two bacterial consortia capable of degrading SLES were isolated from a wastewater treatment plant. The two consortia consisted of three members, Acinetobacter calcoacetiacus and Klebsiella oxytoca in one co-culture (A-K) and Serratia odorifera in the second co-culture (S-A), which contains Acinetobacter calcoacetiacus as well. In all experiments, cells were grown on SLES (1000-7000 ppm) containing the M9 minimal medium as sole carbon source. The co-culture A-K demonstrated a higher growth rate (0.26 h(-1)) and significant greater viability than that of the co-culture S-A (0.21 h(-1)). Glucose, sucrose, maltose, mannitol, and succinic acid as carbon sources produced the same degradation rate (approximately 100 ppm/h) and enhanced the SLES degradation rate by 3-fold upon the control (without an added carbon source). In the case of the co-culture S-A, the situation was different; all the carbon sources being tested except maltose caused a repression in the degradation ability in a range between 25-100%. Maltose causes an enhancement by almost fivefold, compared with the positive control.

Telangiectatic osteosarcoma.

PubMed

Colomina, Jordi; Peiro, Ana; Trullols, Laura; Garcia, Isidre

2013-04-01

To review records of 8 patients with telangiectatic osteosarcoma (TOS) and determine whether pathologic fractures correlate with recurrence and survival. Records of 4 men and 4 women aged 17 to 44 (mean, 28) years treated for TOS were reviewed. RESULTS; Of the 8 patients, 4 developed a pathologic fracture and 4 did not. In each group, 2 patients underwent limb salvage surgery and 2 underwent amputation. All patients received neoadjuvant and adjuvant chemotherapy with a combination of at least 2 of the following drugs: doxorubicin, methotrexate, cisplatin, and vincristin. After a mean follow-up of 5.6 (range, 2-16) years, all 4 patients with a pathologic fracture and 2 of the 4 patients without a pathologic fracture were still alive and disease-free. For the remaining patients, one died after 31 months from progression of a lung metastasis, and the other was alive with the disease and had had 2 recurrences, a lung metastasis, and an infection with Klebsiella oxytoca that eventually led to an amputation. The presence of a pathologic fracture in patients with TOS was not associated with worse outcome in terms of recurrence and survival.

Distinct docking and stabilization steps of the Pseudopilus conformational transition path suggest rotational assembly of type IV pilus-like fibers.

PubMed

Nivaskumar, Mangayarkarasi; Bouvier, Guillaume; Campos, Manuel; Nadeau, Nathalie; Yu, Xiong; Egelman, Edward H; Nilges, Michael; Francetic, Olivera

2014-05-06

The closely related bacterial type II secretion (T2S) and type IV pilus (T4P) systems are sophisticated machines that assemble dynamic fibers promoting protein transport, motility, or adhesion. Despite their essential role in virulence, the molecular mechanisms underlying helical fiber assembly remain unknown. Here, we use electron microscopy and flexible modeling to study conformational changes of PulG pili assembled by the Klebsiella oxytoca T2SS. Neural network analysis of 3,900 pilus models suggested a transition path toward low-energy conformations driven by progressive increase in fiber helical twist. Detailed predictions of interprotomer contacts along this path were tested by site-directed mutagenesis, pilus assembly, and protein secretion analyses. We demonstrate that electrostatic interactions between adjacent protomers (P-P+1) in the membrane drive pseudopilin docking, while P-P+3 and P-P+4 contacts determine downstream fiber stabilization steps. These results support a model of a spool-like assembly mechanism for fibers of the T2SS-T4P superfamily. Copyright © 2014 Elsevier Ltd. All rights reserved.

Distinct docking and stabilization steps of the pseudopilus conformational transition path suggest rotational assembly of type IV pilus-like fibers

PubMed Central

Nivaskumar, Mangayarkarasi; Bouvier, Guillaume; Campos, Manuel; Nadeau, Nathalie; Yu, Xiong; Egelman, Edward H.; Nilges, Michael; Francetic, Olivera

2014-01-01

SUMMARY The closely related bacterial type II secretion (T2S) and type IV pilus (T4P) systems are sophisticated machines that assemble dynamic fibers promoting protein transport, motility or adhesion. Despite their essential role in virulence, the molecular mechanisms underlying helical fiber assembly remain unknown. Here we use electron microscopy and flexible modeling to study conformational changes of PulG pili assembled by the Klebsiella oxytoca T2SS. Neural network analysis of 3900 pilus models suggested a transition path towards low-energy conformations driven by progressive increase in fiber helical twist. Detailed predictions of inter-protomer contacts along this path were tested by site-directed mutagenesis, pilus assembly and protein secretion analyses. We demonstrate that electrostatic interactions between adjacent protomers (P-P+1) in the membrane drive pseudopilin docking, while P-P+3 and P-P+4 contacts determine downstream fiber stabilization steps. These results support a new model of a spool-like assembly mechanism for fibers of the T2SS-T4P superfamily. PMID:24685147

A dual bacterial culture augments Kalanchoe spp. photosynthesis under extreme conditions

NASA Astrophysics Data System (ADS)

Burlak, Olexii; Rogutskyy, Ivan; Danilchenko, Boris; Mikheev, Olexander; Zaetz, Iryna; Lorek, Andreas; Koncz, Alexander; de Vera, Jean-Pierre; Foing, Bernard H.; Kozyrovska, Natalia

In consistence with conception of using microbial technology for plant growing/protosoil for-mation for Lunar/Martian greenhouses (Kozyrovska et al., 2004-2010), we anticipate microbes to alleviate impact of the environmental stressors on plant development. Bacteria can augment physiological processes in plants, for example, photosynthesis, by regulating a hormone level and decreasing glucose sensing in planta (Zhang et al., 2008). The study aimed to examine impact of consortium of well-defined bacteria Klebsiella oxytoca IMBG26 and Paenibacillus sp. IMBG150 on the CAM-plantlets Kalanhoe diagramontiana and Kalanhoe tubiflora pho-tosynthetic activity after acute action of gamma radiation (60Co), Near Martian ultraviolet radiation, low pressure (100 mbar), and high concentrations of CO2 (95Plantlets of K. tubi-flora were exposed to harmful doses of Near Martian UV radiation for 3 hours (26.53 J/cm2). A week before experiment kalanchoe plantlets were subjected to acute effects of ionizing radiation at doses of 30 and 70 Gy. In noninoculated plantlets after 30 Gy the photosynthetic activity fell to 71

Draft genome sequence of CTX-M-type β-lactamase-producing Klebsiella quasipneumoniae subsp. similipneumoniae isolated from a Box turtle.

PubMed

Li, Chien-Feng; Tang, Hui-Ling; Chiou, Chien-Shun; Tung, Kwong-Chung; Lu, Min-Chi; Lai, Yi-Chyi

2018-03-01

Klebsiella spp. are regarded as major pathogens causing infections in humans and various animals. Here we report the draft genome sequence of a CTX-M-type β-lactamase-producing Klebsiella quasipneumoniae subsp. similipneumoniae strain CHKP0062 isolated from a Yellow-margined Box turtle. An Illumina-Solexa platform was used to sequence the genome of CHKP0062. Qualified reads were assembled de novo using Velvet. The draft genome was annotated by the NCBI Prokaryotic Genome Annotation Pipeline (PGAP). The resistome and virulome of the strain were investigated. A total of 5423 protein-coding sequences, 87 tRNAs, 24 rRNAs and 12 ncRNAs were identified in the 5 699 275-bp genome. CHKP0062 was assigned to sequence type ST2131 with the K-loci type as KL67. No virulence-associated genes were identified. However, numerous antimicrobial resistance genes were present in this strain. Plasmid contigs were assembled and revealed homology to the multidrug resistance plasmids pC15-K, pCTX-M3 and pKF3-94, with the carriage of the class A β-lactamase genes bla TEM-1b and bla CTX-M-3 . The genome sequence reported in this study will be useful for comparative genomic analysis regarding the dissemination of clinically important antibiotic resistance genes among Klebsiella spp. isolated from humans and animals. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Evaluation of ceftobiprole activity against a variety of gram-negative pathogens, including Escherichia coli, Haemophilus influenzae (β-lactamase positive and β-lactamase negative), and Klebsiella pneumoniae, in a rabbit meningitis model.

PubMed

Stucki, A; Cottagnoud, M; Acosta, F; Egerman, U; Läuffer, J; Cottagnoud, P

2012-02-01

Ceftobiprole medocaril, a new cephalosporin, is highly active against a broad spectrum of Gram-positive and Gram-negative clinical pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant pneumococci. In this study, we tested ceftobiprole against various Gram-negative pathogens in a rabbit meningitis model and determined its penetration into the cerebrospinal fluid (CSF). In this animal model, ceftobiprole produced an antibacterial activity similar to that of cefepime against an Escherichia coli strain, a Klebsiella pneumoniae strain, and a β-lactamase-negative Haemophilus influenzae strain. Against a β-lactamase-positive H. influenzae strain, ceftobiprole was significantly superior. The penetration of ceftobiprole through inflamed meninges reached about 16% of serum levels compared to about 2% of serum levels through uninflamed meninges.

Evaluation of Ceftobiprole Activity against a Variety of Gram-Negative Pathogens, Including Escherichia coli, Haemophilus influenzae (β-Lactamase Positive and β-Lactamase Negative), and Klebsiella pneumoniae, in a Rabbit Meningitis Model

PubMed Central

Stucki, A.; Cottagnoud, M.; Acosta, F.; Egerman, U.; Läuffer, J.

2012-01-01

Ceftobiprole medocaril, a new cephalosporin, is highly active against a broad spectrum of Gram-positive and Gram-negative clinical pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant pneumococci. In this study, we tested ceftobiprole against various Gram-negative pathogens in a rabbit meningitis model and determined its penetration into the cerebrospinal fluid (CSF). In this animal model, ceftobiprole produced an antibacterial activity similar to that of cefepime against an Escherichia coli strain, a Klebsiella pneumoniae strain, and a β-lactamase-negative Haemophilus influenzae strain. Against a β-lactamase-positive H. influenzae strain, ceftobiprole was significantly superior. The penetration of ceftobiprole through inflamed meninges reached about 16% of serum levels compared to about 2% of serum levels through uninflamed meninges. PMID:22064544

Carbapenem-Nonsusceptible Enterobacteriaceae in Taiwan

PubMed Central

Wang, Jann-Tay; Wu, Un-In; Lauderdale, Tsai-Ling Yang; Chen, Mei-Chen; Li, Shu-Ying; Hsu, Le-Yin; Chang, Shan-Chwen

2015-01-01

A total of 1135 carbapenem-resistant (nonsusceptible) Enterobacteriaceae (CRE) isolates were recovered between November 2010 and July 2012 (517 from 2010-2011 and 618 from 2012) from 4 hospitals in Taiwan. Carbapenemase-producing Enterobacteriaceae (CPE) comprised 5.0% (57 isolates), including 17 KPC-2 (16 Klebsiella pneumoniae and 1 Escherichia coli), 1 NDM-1 (K. oxytoca), 37 IMP-8 (26 Enterobacter cloacae, 4 Citrobacter freundii, 4 Raoultella planticola, 1 K. pneumoniae, 1 E. coli and 1 K. oxytoca), and 2 VIM-1 (1 E. cloacae, 1 E. coli). The KPC-2-positive K. pneumoniae were highly clonal even in isolates from different hospitals, and all were ST11. IMP-8 positive E. cloacae from the same hospitals showed higher similarity in PFGE pattern than those from different hospitals. A total of 518 CRE isolates (45.6%) were positive for bla ESBL, while 704 (62.0%) isolates were bla AmpC-positive, 382 (33.6% overall) of which carried both bla ESBL and bla AmpC. CTX-M (414, 80.0%) was the most common bla ESBL, while DHA (497, 70.6%) and CMY (157, 22.3%) were the most common bla AmpC. Co-carriage of bla ESBL and bla AmpC was detected in 31 (54.4%) and 15 (26.3%) of the 57 CPE, respectively. KPC-2 was the most common carbapenemase detected in K. pneumoniae (2.8%), while IMP-8 was the most common in E. cloacae (9.7%). All KPC-2-positive CRE were resistant to all three tested carbapenems. However, fourteen of the 37 IMP-8-positive CRE were susceptible to both imipenem and meropenem in vitro. Intra- and inter-hospital spread of KPC-2-producing K. pneumoniae and IMP-8-producing E. cloacae likely occurred. Although the prevalence of CPE is still low, careful monitoring is urgently needed. Non-susceptibility to ertapenem might need to be considered as one criterion of definition for CRE in areas where IMP type carbapenemase is prevalent. PMID:25794144

Klebsiella pneumoniae type 3 fimbria-mediated immunity to infection in the murine model of respiratory disease.

PubMed

Lavender, Heather; Jagnow, Jennifer J; Clegg, Steven

2005-06-01

Type 3 fimbriae are expressed by most strains of Klebsiella pneumoniae and facilitate adherence to the basement membrane of human respiratory tissues. The ability of these appendages to stimulate a protective immune response in vivo has not been investigated. A murine model of acute pneumonia was used to determine whether the production of type 3 fimbria-specific antibodies correlated with protection against infection by K. pneumoniae. Purified fimbriae from several strains were used to immunize mice prior to challenge with a virulent strain. The immunized mice produced high titers of specific antibody and this was associated with protection against challenge with a low dose of bacteria that was lethal in unimmunized animals. However, challenge with a high number of bacteria resulted in no protection against infection.

Activity of Antimicrobial Combinations against KPC-2-Producing Klebsiella pneumoniae in a Rat Model and Time-Kill Assay

PubMed Central

Aranha Junior, Ayrton Alves; Arend, Lavinia Nery; Ribeiro, Vanessa; Zavascki, Alexandre Prehn; Tuon, Felipe Francisco

2015-01-01

This study evaluated the efficacy of tigecycline (TIG), polymyxin B (PMB), and meropenem (MER) in 80 rats challenged with Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae infection. A time-kill assay was performed with the same strain. Triple therapy and PMB+TIG were synergistic, promoted 100% survival, and produced negative peritoneal cultures, while MER+TIG showed lower survival and higher culture positivity than other regimens (P = 0.018) and was antagonistic. In vivo and in vitro studies showed that combined regimens, except MER+TIG, were more effective than monotherapies for this KPC-producing strain. PMID:25896686

Reduction of molybdate to molybdenum blue by Klebsiella sp. strain hkeem.

PubMed

Lim, H K; Syed, M A; Shukor, M Y

2012-06-01

A novel molybdate-reducing bacterium, tentatively identified as Klebsiella sp. strain hkeem and based on partial 16s rDNA gene sequencing and phylogenetic analysis, has been isolated. Strain hkeem produced 3 times more molybdenum blue than Serratia sp. strain Dr.Y8; the most potent Mo-reducing bacterium isolated to date. Molybdate was optimally reduced to molybdenum blue using 4.5 mM phosphate, 80 mM molybdate and using 1% (w/v) fructose as a carbon source. Molybdate reduction was optimum at 30 °C and at pH 7.3. The molybdenum blue produced from cellular reduction exhibited absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. Inhibitors of electron transport system such as antimycin A, rotenone, sodium azide, and potassium cyanide did not inhibit the molybdenum-reducing enzyme. Mercury, silver, and copper at 1 ppm inhibited molybdenum blue formation in whole cells of strain hkeem. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The avian chorioallantoic membrane in ovo--a useful model for bacterial invasion assays.

PubMed

Adam, Rüdiger; Mussa, Shueb; Lindemann, Dirk; Oelschlaeger, Tobias A; Deadman, Mary; Ferguson, David J P; Moxon, Richard; Schroten, Horst

2002-09-01

The aim of this study was to evaluate the practicability of the chick embryo chorioallantoic membrane (CAM) with special regard to the 'natural air sac' technique (NAST) of preparation for in-vivo research on the invasive potential of bacterial strains of various enterobacterial species. It was sought to establish an experimental system more closely resembling in-vivo conditions than cell lines on one hand, and cheaper and easier to handle than established animal models on the other. Fertilized eggs of the domestic fowl were incubated. The CAM was prepared atraumatically at the natural air space of the egg, and a cannula was inserted for subsequent extraction of allantoic fluid (AF) below the CAM. The CAM was then inoculated with either one out of five strains of Klebsiella pneumoniae, an Escherichia coli K-12 strain or a Salmonella typhimurium strain, either alone or in combinations, respectively. AF samples were extracted at certain time points, and the presence of bacteria was determined by cultivation. Penetration and mortality ratios of the infected embryos were calculated. In addition, the mode of crossing the epithelial barrier was examined by electron microscopy. Differing rates of invasion through the CAM and rates of mortality of the chicken embryos demonstrated a clear dependency on the inoculated bacterial strain. Low invading bacteria could be distinguished from intermediate strains, and from strains exerting a strong capability of invasion and killing of the embryos. Simultaneous monotopical inoculation of Klebsiella and E. coli showed a permissive effect of co-incubated Klebsiella on the invasiveness of E. coli. The chick embryo CAM prepared by NAST has shown to be a useful model for in vivo studies on invasion capabilities, pathogenicity and interactions of inoculated bacteria.

Detection of a Gentamicin-Resistant Burn Wound Strain of Pseudomonas Aeruginosa but Sensitive to Honey and Garcinia Kola (Heckel) Seed Extract

PubMed Central

Adeleke, O.E.; Coker, M.E.; Oke, O.B.

2010-01-01

Summary Studies on Staphylococcus aureus and Staphylococcus intermedius from dog and cat, and also on Staphylococcus aureus from wound and pyoderma infections, have shown a correlation between the site of microbial infection and antimicrobial susceptibility. Both the methanolic extract concentrate of Garcinia kola (Heckel) seeds and natural honey have been associated with activity on bacterial isolates from respiratory tract infections. In this study, selected bacteria belonging to genera from burn wound infection sites were treated with natural honey and methanolic extract concentrate of Garcinia kola in antimicrobial susceptibility tests separately and in combined form, and also with gentamicin and methanol as controls. The two natural products were found to be active on the bacterial isolates, excluding Klebsiella pneumoniae strains, all of which showed resistance to honey. Combination forms of the two natural products were active only on the strains of Pseudomonas aeruginosa. At 4 and 8 µg/ml, gentamicin was ineffective on the three strains of Klebsiella pneumoniae while 8 µg/ml was moderately active on only two strains of Pseudomonas aeruginosa. One strain of Pseudomonas aeruginosa, UCH002, was resistant to gentamicin beyond 1,000 µ/ml. Gentamicin at 4 µ/ml was inhibitory to one strain of Escherichia coli and two strains of Staphylococcus aureus. Though the antimicrobial activity of the two natural products tested had been previously reported against microbial agents of respiratory tract infection, it was also recorded in this study. The lack of activity of each of the three honey types used in this study against the Klebsiella pneumoniae strains tested underscores the need to exclude this organism from burn wound infections before embarking on treatment with honey. The sensitivity of one high-level gentamicin-resistant strain of Pseudomonas aeruginosa to honey and Garcinia kola seed extract was noteworthy considering the therapeutic failures of gentamicin and other antibiotics against Pseudomonas aeruginosa. PMID:21991206

Capsule-Targeting Depolymerase, Derived from Klebsiella KP36 Phage, as a Tool for the Development of Anti-Virulent Strategy.

PubMed

Majkowska-Skrobek, Grażyna; Łątka, Agnieszka; Berisio, Rita; Maciejewska, Barbara; Squeglia, Flavia; Romano, Maria; Lavigne, Rob; Struve, Carsten; Drulis-Kawa, Zuzanna

2016-12-01

The rise of antibiotic-resistant Klebsiella pneumoniae , a leading nosocomial pathogen, prompts the need for alternative therapies. We have identified and characterized a novel depolymerase enzyme encoded by Klebsiella phage KP36 (depoKP36), from the Siphoviridae family. To gain insights into the catalytic and structural features of depoKP36, we have recombinantly produced this protein of 93.4 kDa and showed that it is able to hydrolyze a crude exopolysaccharide of a K. pneumoniae host. Using in vitro and in vivo assays, we found that depoKP36 was also effective against a native capsule of clinical K. pneumoniae strains, representing the K63 type, and significantly inhibited Klebsiella -induced mortality of Galleria mellonella larvae in a time-dependent manner. DepoKP36 did not affect the antibiotic susceptibility of Klebsiella strains. The activity of this enzyme was retained in a broad range of pH values (4.0-7.0) and temperatures (up to 45 °C). Consistently, the circular dichroism (CD) spectroscopy revealed a highly stability with melting transition temperature (T m ) = 65 °C. In contrast to other phage tailspike proteins, this enzyme was susceptible to sodium dodecyl sulfate (SDS) denaturation and proteolytic cleavage. The structural studies in solution showed a trimeric arrangement with a high β-sheet content. Our findings identify depoKP36 as a suitable candidate for the development of new treatments for K. pneumoniae infections.

Generation and Validation of the iKp1289 Metabolic Model for Klebsiella pneumoniae KPPR1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henry, Christopher S.; Rotman, Ella; Lathem, Wyndham W.

Klebsiella pneumoniae has a reputation for causing a wide range of infectious conditions, with numerous highly virulent and antibiotic-resistant strains. Metabolic models have the potential to provide insights into the growth behavior, nutrient requirements, essential genes, and candidate drug targets in these strains. Here we develop a metabolic model for KPPR1, a highly virulent strain of K. pneumoniae. We apply a combination of Biolog phenotype data and fitness data to validate and refine our KPPR1 model. The final model displays a predictive accuracy of 75% in identifying potential carbon and nitrogen sources for K. pneumoniae and of 99% in predictingmore » nonessential genes in rich media. We demonstrate how this model is useful in studying the differences in the metabolic capabilities of the low-virulence MGH 78578 strain and the highly virulent KPPR1 strain. For example, we demonstrate that these strains differ in carbohydrate metabolism, including the ability to metabolize dulcitol as a primary carbon source. Our model makes numerous other predictions for follow-up verification and analysis.« less

Sewage treatment effluents in Delhi: A key contributor of β-lactam resistant bacteria and genes to the environment.

PubMed

Lamba, Manisha; Ahammad, Shaikh Ziauddin

2017-12-01

Rapid emergence of antibiotic resistance (AR) in developing countries is posing a greater health risk and increasing the global disease burden. Lack of access to safe drinking water, poor sanitation and inadequate sewage treatment facilities in these countries are fueling the problem associated with emergence of AR. Rapid proliferation of AR mediated by treated and untreated discharges from sewage treatment plants (STPs) is a prime public health concern. This study aims to understand the occurrence, fate, and routes of proliferation of carbapenem (KPC) and extended spectrum β-lactam (ESBL) resistant bacteria, and selected resistant genes in the samples collected from different unit operations in 12 STPs in New Delhi over two seasons. Strong correlation observed between faecal coliform levels and KPC (R = 0.95, p = 0.005, n = 60) and ESBL (R = 0.94, p = 0.004, n = 60) resistant bacteria levels indicates possible association of resistant bacteria with faecal matter. Different unit operations in STPs proved inefficient in treating resistant bacteria and genes present in the wastewater. However, inclusion of tertiary treatment (chlorination) unit and anaerobic digester in the present STPs resulted in better removal of AR. Significant correlations between antibiotic resistant genes (ARGs) and integron levels indicates a potential for higher rate of AR proliferation in the environment. Microbial culturing indicated the presence of clinically significant drug-resistant pathogens such as Escherichia coli, Pseudomonas putida, Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella pneumoniae, Klebsiella oxytoca, Acinetobacter baumannii, Shigella dysentery and Aeromonas caviae in the STP effluents. The emergence and spread of resistant bacteria through STP effluents poses exposure risk for the residents of the city. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cefoxitin-based antibiotic therapy for extended-spectrum β-lactamase-producing Enterobacteriaceae prostatitis: a prospective pilot study.

PubMed

Demonchy, Elisa; Courjon, Johan; Ughetto, Estelle; Durand, Matthieu; Risso, Karine; Garraffo, Rodolphe; Roger, Pierre-Marie

2018-06-01

The emergence of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) infections requires re-assessment of therapeutic choices. Here we report the efficacy of cefoxitin-based antibiotic therapy for ESBL-E prostatitis. A prospective study including patients with ESBL-E prostatitis resistant to trimethoprim/sulfamethoxazole and fluoroquinolones from January 2014 to March 2016 was conducted. Cefoxitin was administered by continuous infusion for 3 weeks in the case of acute bacterial prostatitis or 6 weeks in the case of chronic bacterial prostatitis (CBP), with intravenous fosfomycin for the first 5 days. Urological investigations were performed to diagnose underlying urinary tract pathology. Clinical and microbiological efficacy were evaluated 3 months (M3) and 6 months (M6) after the end of therapy. A total of 23 patients were included in the study. The median patient age was 74 years (range 48-88 years). Of the 23 infections, 14 (61%) were CBP and 12 (52%) were healthcare-associated infections. The bacteria involved were Escherichia coli in 11 cases, Klebsiella pneumoniae in 10 cases and Klebsiella oxytoca in 2 cases. Clinical cure was observed in 19/23 patients (83%) at M3 and in 17/22 patients (77%) at M6. Urocultures were sterile in 13/23 patients (57%) at M3 and in 9/19 patients (47%) and M6. Urinary colonisation was observed in 6/19 patients (32%) with clinical cure at M3 and 5/14 patients (36%) with clinical cure at M6. No resistance to cefoxitin was detected. Surgical treatment was required for 7/23 patients (30%). In conclusion, cefoxitin-based antibiotic therapy is suitable for difficult-to-treat ESBL-E infections such as prostatitis. Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Impact of Extended Spectrum Beta-Lactamase Producing Klebsiella pneumoniae Infections in Severely Burned Patients

DTIC Science & Technology

2010-09-01

versus nosocomial Klebsiella pneumoniae bacteremia: clinical features, treatment outcomes, and clinical implication of antimicrobial resistance . J...antibiotic resistance , strain clonality, and other host factors on morbidity and mortality. All patients with thermal burns infected with K pneumoniae between...revealed that an infection with ESBL-producing K pneumoniae during the hospital stay was the factor most predictive of death, with a nearly 4-fold increased

Suppurative peritonitis by Klebsiella pneumoniae in captive gold-handed tamarin (Saguinus midas midas).

PubMed

Guerra, Maria F L; Teixeira, Rodrigo H F; Ribeiro, Vanessa L; Cunha, Marcos P V; Oliveira, Maria G X; Davies, Yamê M; Silva, Ketrin C; Silva, Ana P S; Lincopan, Nilton; Moreno, Andrea M; Knöbl, Terezinha

2016-02-01

This report describes an outbreak of suppurative peritonitis caused by Klebsiella pneumoniae in an adult female of captive golden-handed tamarin (Saguinus midas midas). Two virulent and multidrug-resistant strains were isolated and classified through MLST as ST60 and ST1263. The microbiological diagnosis works as a support tool for preventive measures. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A multiple antibiotic and serum resistant oligotrophic strain, Klebsiella pneumoniae MB45 having novel dfrA30, is sensitive to ZnO QDs

PubMed Central

2011-01-01

Background The aim of this study was to describe a novel trimethoprim resistance gene cassette, designated dfrA30, within a class 1 integron in a facultatively oligotrophic, multiple antibiotic and human serum resistant test strain, MB45, in a population of oligotrophic bacteria isolated from the river Mahananda; and to test the efficiency of surface bound acetate on zinc oxide quantum dots (ZnO QDs) as bactericidal agent on MB45. Methods Diluted Luria broth/Agar (10-3) media was used to cultivate the oligotrophic bacteria from water sample. Multiple antibiotic resistant bacteria were selected by employing replica plate method. A rapid assay was performed to determine the sensitivity/resistance of the test strain to human serum. Variable region of class 1 integron was cloned, sequenced and the expression of gene coding for antibiotic resistance was done in Escherichia coli JM 109. Identity of culture was determined by biochemical phenotyping and 16S rRNA gene sequence analyses. A phylogenetic tree was constructed based on representative trimethoprim resistance-mediating DfrA proteins retrieved from GenBank. Growth kinetic studies for the strain MB45 were performed in presence of varied concentrations of ZnO QDs. Results and conclusions The facultatively oligotrophic strain, MB45, resistant to human serum and ten antibiotics trimethoprim, cotrimoxazole, ampicillin, gentamycin, netilmicin, tobramycin, chloramphenicol, cefotaxime, kanamycin and streptomycin, has been identified as a new strain of Klebsiella pneumoniae. A novel dfr gene, designated as dfrA30, found integrated in class 1 integron was responsible for resistance to trimethoprim in Klebsiella pneumoniae strain MB45. The growth of wild strain MB45 was 100% arrested at 500 mg/L concentration of ZnO QDs. To our knowledge this is the first report on application of ZnO quantum dots to kill multiple antibiotics and serum resistant K. pneumoniae strain. PMID:21595893

Klebsiella spp. in endoscopy-associated infections: we may only be seeing the tip of the iceberg.

PubMed

Gastmeier, P; Vonberg, R-P

2014-02-01

Two endoscopy-associated nosocomial outbreaks caused by carbapenemase-producing Klebsiella pneumoniae (CPKP) were recently observed in two German hospitals. In this study, we performed a systematic search of the medical literature in order to elucidate the epidemiology of Klebsiella spp. in endoscopy-associated outbreaks. Medline, the Outbreak Database ( http://www.outbreak-database.com ) and reference lists of articles extracted from these databases were screened for descriptions of endoscopy-associated nosocomial outbreaks. The data extracted and analysed were: (1) the type of medical department affected; (2) characterisation of pathogen to species and conspicuous resistance patterns (if applicable); (3) type of endoscope and the grade of its contamination; (4) number and the types of infections; (5) actual cause of the outbreak. A total of seven nosocomial outbreaks were identified, of which six were outbreaks of endoscopic retrograde cholangiopancreatography-related infections and caused by contaminated duodenoscopes. Including our own outbreaks in the analysis, we identified one extended-spectrum beta-lactamase-producing K. pneumoniae strain and six CPKP strains. Insufficient reprocessing after the use of the endoscope was the main reason for subsequent pathogen transmission. There were only two reports of nosocomial outbreaks due to Klebsiella spp. in the first three decades of endoscopic procedures, but seven additional outbreaks of this kind have been reported within the last 4 years. It is very likely that many of such outbreaks have been missed in the past because this pathogen belongs to the physiological gut flora. However, with the emergence of highly resistant (carbapenemase-producing) strains, strict adherence to infection control guidelines is more important than ever.

Activity of antimicrobial combinations against KPC-2-producing Klebsiella pneumoniae in a rat model and time-kill assay.

PubMed

Toledo, Paula Virginia Michelon; Aranha Junior, Ayrton Alves; Arend, Lavinia Nery; Ribeiro, Vanessa; Zavascki, Alexandre Prehn; Tuon, Felipe Francisco

2015-07-01

This study evaluated the efficacy of tigecycline (TIG), polymyxin B (PMB), and meropenem (MER) in 80 rats challenged with Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae infection. A time-kill assay was performed with the same strain. Triple therapy and PMB+TIG were synergistic, promoted 100% survival, and produced negative peritoneal cultures, while MER+TIG showed lower survival and higher culture positivity than other regimens (P = 0.018) and was antagonistic. In vivo and in vitro studies showed that combined regimens, except MER+TIG, were more effective than monotherapies for this KPC-producing strain. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Histamine production by Klebsiella pneumoniae and an incident of scombroid fish poisoning.

PubMed Central

Taylor, S L; Guthertz, L S; Leatherwood, M; Lieber, E R

1979-01-01

A histamine-producing strain of Klebsiella pneumoniae was isolated from a sample of tuna sashimi implicated in an outbreak of scombroid fish poisoning. None of the other nine gram-negative bacterial strains isolated from the tuna sashimi was capable of equivalent histamine production. Bacterial histamine production was monitored in a tuna fish infusion broth (TFIB), and the implicated K. pneumoniae was capable of producing 442 mg of histamine per 100 g of tuna in TFIB in 7 h under controlled incubation conditions. Only 12 of 50 other K. pneumoniae strains, representing 5 distinct biochemical types, which had been originally isolated from foods, were able to produce such levels of histamine in TFIB. No correlation was found between histamine production and other biochemical characteristics or antibiotic resistance. Of the 12 histamine-producing strains, 11 belonged to type 2, which is characterized as indole negative with positive reactions in the urea and Voges-Proskauer tests. However, only 50% of the type 2 strains examined produced high levels of histamine in TFIB. Additionally, the implicated K. pneumoniae strain and one other strain belonged to type 1, which is characterized by positive reactions in the indole, urea, and Voges-Proskauer tests. PMID:373626

Evaluating Different Virulence Traits of Klebsiella pneumoniae Using Dictyostelium discoideum and Zebrafish Larvae as Host Models

PubMed Central

Marcoleta, Andrés E.; Varas, Macarena A.; Ortiz-Severín, Javiera; Vásquez, Leonardo; Berríos-Pastén, Camilo; Sabag, Andrea V.; Chávez, Francisco P.; Allende, Miguel L.; Santiviago, Carlos A.; Monasterio, Octavio; Lagos, Rosalba

2018-01-01

Multiresistant and invasive hypervirulent Klebsiella pneumoniae strains have become one of the most urgent bacterial pathogen threats. Recent analyses revealed a high genomic plasticity of this species, harboring a variety of mobile genetic elements associated with virulent strains, encoding proteins of unknown function whose possible role in pathogenesis have not been addressed. K. pneumoniae virulence has been studied mainly in animal models such as mice and pigs, however, practical, financial, ethical and methodological issues limit the use of mammal hosts. Consequently, the development of simple and cost-effective experimental approaches with alternative host models is needed. In this work we described the use of both, the social amoeba and professional phagocyte Dictyostelium discoideum and the fish Danio rerio (zebrafish) as surrogate host models to study K. pneumoniae virulence. We compared three K. pneumoniae clinical isolates evaluating their resistance to phagocytosis, intracellular survival, lethality, intestinal colonization, and innate immune cells recruitment. Optical transparency of both host models permitted studying the infective process in vivo, following the Klebsiella-host interactions through live-cell imaging. We demonstrated that K. pneumoniae RYC492, but not the multiresistant strains 700603 and BAA-1705, is virulent to both host models and elicits a strong immune response. Moreover, this strain showed a high resistance to phagocytosis by D. discoideum, an increased ability to form biofilms and a more prominent and irregular capsule. Besides, the strain 700603 showed the unique ability to replicate inside amoeba cells. Genomic comparison of the K. pneumoniae strains showed that the RYC492 strain has a higher overall content of virulence factors although no specific genes could be linked to its phagocytosis resistance, nor to the intracellular survival observed for the 700603 strain. Our results indicate that both zebrafish and D. discoideum are advantageous host models to study different traits of K. pneumoniae that are associated with virulence. PMID:29479519

Chemical compositions and antimicrobial activities of Athrixia phylicoides DC. (bush tea), Monsonia burkeana (special tea) and synergistic effects of both combined herbal teas.

PubMed

Tshivhandekano, Itani; Ntushelo, Khayalethu; Ngezimana, Wonder; Tshikalange, Thilivhali Emmanuel; Mudau, Fhatuwani Nixwell

2014-09-01

To determine the chemical compositions and evaluate the antimicrobial activity of bush tea (Athrixia phylicoides DC.), special tea (Monsonia burkeana) and synergy (combination of bush tea and special tea). Total polyphenols were determined using the methods reported by Singleton and Rossi (1965) and modified by Waterman and Mole (1994). Tannins were determined using vanillin HCL methods described by Prince et al. (1978). Total antioxidants were determined using the methods described by Awika et al. (2004). The micro dilution technique using 96-well micro-plates, as described by Eloff (1998) was used to obtain the minimum inhibition concentration (MIC) and minimum microbicidal concentration (MMC) values of the ethanol extracts against the microorganisms under study. The microbes strain used was Gram negative bacteria such as Escherichia coli, Klebsiella oxytoca, Proteus vulgaris, Serratia marcescens, Salmonella typhi, Klebsiella pneumonia; Gram positive bacteria such as Bacillus cereus, Staphylococcus aureus and a fungus Candida albicans. The results demonstrated that special tea contains significantly higher content of total polyphenols (8.34 mg/100 g) and total antioxidant (0.83 mg/100 g) as compared to bush tea [total polyphenols (6.41 mg/100g) and total antioxidant (0.63 mg/100g)] and combination of bush tea and special tea [total polyphenols (6.42 mg/100 g) and total antioxidant (0.64 mg/100 g)]. There was no significant difference in tannins between bush tea, special tea and synergy. The results of antimicrobial activity (MIC and MMC) demonstrated that the ethanol extracts of bush tea, special tea and synergy possessed antimicrobial activity against all microorganisms at different zones. The MIC of bush tea ranged from 1.56 to 12.50 mg/mL while the MMC ranged from 0.78 to 12.50 mg/mL. Special tea's MIC ranged from 0.39 to 12.50 mg/mL while the MMC ranged from 0.01 to 12.50 mg/mL. The MIC of synergy ranged from 3.13 to 12.50 mg/mL while the MMC ranged from 3.13 to 12.50 mg/mL without positive synergistic effect recorded. Both bush and special tea contain total polyphenols, total antioxidants and tannins with special tea containing a significantly higher total polyphenols and total antioxidant as compared to bush tea and synergy. Bush tea, special tea and synergy possess antimicrobial activity at various degrees. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Improved ethanol tolerance and ethanol production from glycerol in a streptomycin-resistant Klebsiella variicola mutant obtained by ribosome engineering.

PubMed

Suzuki, Toshihiro; Seta, Kohei; Nishikawa, Chiaki; Hara, Eri; Shigeno, Toshiya; Nakajima-Kambe, Toshiaki

2015-01-01

To improve the ethanol tolerance of the Klebsiella variicola strain TB-83, we obtained the streptomycin-resistant, ethanol-tolerant mutant strain TB-83D by a ribosome engineering approach. Strain TB-83D was able to grow in the presence of 7% (v/v) ethanol and it showed higher ethanol production than strain TB-83. Examination of various culture conditions revealed that yeast extract was essential for ethanol production and bacterial growth. In addition, ethanol production was elevated to 32g/L by the addition of yeast extract; however, ethanol production was inhibited by formate accumulation. With regard to cost reduction, the use of corn steep liquor (CSL) markedly decreased the formate concentration, and 34g/L ethanol was produced by combining yeast extract with CSL. Our study is the first to improve ethanol tolerance and productivity by a ribosome engineering approach, and we found that strain TB-83D is effective for ethanol production from glycerol. Copyright © 2014 Elsevier Ltd. All rights reserved.

Surface changes and polymyxin interactions with a resistant strain of Klebsiella pneumoniae.

PubMed

Velkov, Tony; Deris, Zakuan Z; Huang, Johnny X; Azad, Mohammad A K; Butler, Mark; Sivanesan, Sivashangarie; Kaminskas, Lisa M; Dong, Yao-Da; Boyd, Ben; Baker, Mark A; Cooper, Matthew A; Nation, Roger L; Li, Jian

2014-05-01

This study examines the interaction of polymyxin B and colistin with the surface and outer membrane components of a susceptible and resistant strain of Klebsiella pneumoniae. The interaction between polymyxins and bacterial membrane and isolated LPS from paired wild type and polymyxin-resistant strains of K. pneumoniae were examined with N-phenyl-1-naphthylamine (NPN) uptake, fluorometric binding and thermal shift assays, lysozyme and deoxycholate sensitivity assays, and by (1)H NMR. LPS from the polymyxin-resistant strain displayed a reduced binding affinity for polymyxins B and colistin in comparison with the wild type LPS. The outer membrane NPN permeability of the resistant strain was greater compared with the susceptible strain. Polymyxin exposure enhanced the permeability of the outer membrane of the wild type strain to lysozyme and deoxycholate, whereas polymyxin concentrations up to 32 mg/ml failed to permeabilize the outer membrane of the resistant strain. Zeta potential measurements revealed that mid-logarithmic phase wild type cells exhibited a greater negative charge than the mid-logarithmic phase-resistant cells. Taken together, our findings suggest that the resistant derivative of K. pneumoniae can block the electrostatically driven first stage of polymyxin action, which thereby renders the hydrophobically driven second tier of polymyxin action on the outer membrane inconsequential.

Spread of ESBL/AmpC-producing Escherichia coli and Klebsiella pneumoniae in the community through ready-to-eat sandwiches in Algeria.

PubMed

Yaici, Lydia; Haenni, Marisa; Métayer, Véronique; Saras, Estelle; Mesbah Zekar, Ferielle; Ayad, Meriem; Touati, Abdelaziz; Madec, Jean-Yves

2017-03-20

The spread of Extended-Spectrum β-Lactamases (ESBLs) or AmpC β-Lactamases (AmpC) encoding genes in healthy human populations is of major concern. The role of the food chain has been questioned since numerous studies reported surface contamination of retail meat or crude vegetables with ESBL/AmpC-producing Enterobacteriaceae (ESBL/AmpC-E). Nonetheless, these food products are intended to be cooked or washed before consumption so that the risk of human transfer might be low. Here, the presence of ESBL/AmpC-E was investigated in ready-to-eat (RTE) sandwiches purchased in the street in the city of Bejaia, Algeria. Thirty ESBL/AmpC-producing E. coli (n=18), K. pneumoniae (n=11) and K. oxytoca (n=1) were recovered from 21 sandwiches purchased in 14 of the 100 shops that were visited (14%). Twenty-four isolates (13 E. coli, 10 K. pneumoniae, 1 K. oxytoca) produced one or two ESBLs, while 5 E. coli and 1 K. pneumoniae isolates produced an AmpC. Among those, 12 E. coli harbored bla CTX-M-1 (n=7), bla CTX-M-15 (n=3), bla CTX-M-14 (n=1) or bla CTX-M-2 (n=1) and one E. coli co-harbored the bla CTX-M-15 and bla SHV-2 genes. The 10 K. pneumoniae displayed bla CTX-M-15 (n=7), bla SHV-2 (n=3), bla SHV-12 (n=1) or bla CTX-M-1 (n=1), including two isolates presenting a bla CTX-M-15 /bla SHV-2 or bla CTX-M-1 /bla SHV-2 combination. The K. oxytoca harbored the bla SHV-2 gene, and one K. pneumoniae and four E. coli displayed bla DHA and bla CMY-2 , respectively. Most isolates (26/30, n=87%) also possessed the aac(6')-Ib-cr gene. Identical ESBL/AmpC-producing E. coli or K. pneumoniae clones were detected at different places across the city. This may reflect cross-contamination through poor handling practices, contaminated equipment, common ingredients or environmental factors. Of note, the emergent ST405 K. pneumoniae human clone was identified as a CTX-M-15 producer. This study highlights the presence of ESBL/AmpC-E in RTE sandwiches, which are a source of direct transfer to the human gut. These data indicate that fast food shops should be regarded as ESBL/AmpC reservoirs, and a risk for humans. Major efforts should be made in Algeria through guidelines on good practices in the food chain, and more globally in all countries sharing similar poor levels of food hygiene worldwide. Copyright © 2017 Elsevier B.V. All rights reserved.

[Occurrence of AmpC-positive Klebsiella pneumoniae strains in patients with haematological malignancies].

PubMed

Chromá, Magdaléna; Kolár, Milan; Sauer, Pavel; Faber, Edgar; Stosová, Tatána; Koukalová, Dagmar; Indrák, Karel

2008-10-01

Currently, important bacterial beta-lactamases of increasing clinical significance include AmpC enzymes. The aim was to assess their occurrence in Klebsiella pneumoniae strains isolated from patients with haematological malignancies in a prospective study. Over a 2-month period, strains of the species were isolated from clinical material obtained from patients hospitalized at the Department of Haemato-Oncology of the University Hospital Olomouc. The strains were identified using standard microbiological techniques and the Vitek 2 automated system. Production of AmpC beta-lactamases was roughly determined by phenotypic tests and subsequently confirmed by PCR detection of genes encoding these enzymes. During the above-mentioned period, a total of 35 K. pneumoniae isolates were collected. In 7 of them, production of AmpC beta-lactamases was preliminarily detected by phenotypic test. The multiplex PCR method confirmed phenotyping and determined DHA types in all the isolates. All AmpC-positive isolates were false-susceptible to at least one of the tested third-generation cephalosporins. In one patient, clinically apparent infection caused by this strain was documented. The reported results suggest the possibility of occurrence of AmpC-beta-lactamases in K. pneumoniae strains with clinical significance.

The therapeutic effect of tigecycline, unlike that of Ceftazidime, is not influenced by whether the Klebsiella pneumoniae strain produces extended-spectrum β-lactamases in experimental pneumonia in rats.

PubMed

Goessens, Wil H F; Mouton, Johan W; Ten Kate, Marian T; Sörgel, Fritz; Kinzig, Martina; Bakker-Woudenberg, Irma A J M

2013-01-01

The efficacies of tigecycline and ceftazidime against fatal pneumonia in rats caused by an extended-spectrum β-lactamase (ESBL)-positive Klebsiella pneumoniae strain or its wild-type (WT) progenitor were compared. Ceftazidime at 12.5 or 50 mg/kg of body weight twice daily (b.i.d.) was effective (50% or 100% rat survival) in pneumonia caused by the WT isolate but unsuccessful (100% rat mortality) in pneumonia caused by the ESBL-positive variant. In contrast, tigecycline at 6.25, 12.5, or 25 mg/kg b.i.d. showed dosage-dependent efficacy up to 100% rat survival irrespective of the ESBL character of the infecting organism.

The species accuracy of the Most Probable Number (MPN) European Union reference method for enumeration of Escherichia coli in marine bivalves.

PubMed

Grevskott, Didrik Hjertaker; Svanevik, Cecilie Smith; Wester, Astrid Louise; Lunestad, Bjørn Tore

2016-12-01

Continuous European Union programmes with specified methods for enumeration of Escherichia coli in bivalves for human consumption are currently running. The objective of this research was to examine the species accuracy of the five times three tube Most Probable Number (MPN) EU reference method used for detection of E. coli in marine bivalves. Among 549 samples of bivalves harvested from Norwegian localities during 2014 and 2015, a total number of 200 bacterial isolates were prepared from randomly selected culture-positive bivalves. These presumptive E. coli isolates were characterized biochemically by the Analytical Profile Index (API) 20E, as well as by Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS). The majority of isolates (90%) were identified as E. coli, by both API 20E and MALDI-TOF MS. Ten isolates (5%) were identified as Klebsiella pneumoniae, while one isolate was identified as K. oxytoca by both methods, whereas three isolates were identified as Acinetobacter baumannii, Citrobacter braakii, and Enterobacter cloacae, respectively. The identification of the remaining six isolates were not in compliance between the two methods. Copyright © 2016 Elsevier B.V. All rights reserved.

High mortality among patients infected with hypervirulent antimicrobial-resistant capsular type K1 Klebsiella pneumoniae strains in Taiwan.

PubMed

Lin, Yi-Tsung; Cheng, Yi-Hsiang; Juan, Chih-Han; Wu, Ping-Feng; Huang, Yi-Wei; Chou, Sheng-Hua; Yang, Tsuey-Ching; Wang, Fu-Der

2018-06-12

Capsular type K1 Klebsiella pneumoniae, highly virulent strains which are common in Asian countries, can cause pyogenic infections. These hypervirulent strains are usually susceptible to most antimicrobials, except for ampicillin. Little is known regarding the clinical and molecular characteristics of antimicrobial-resistant K1 K. pneumoniae strains. This retrospective study evaluated patients infected with capsular type K1 K. pneumoniae strains in a Taiwanese medical centre between April 2013 and March 2016. Antimicrobial-resistant strains were defined based on non-susceptibility to antimicrobial agents except ampicillin. We compared the clinical outcome of patients infected with and without antimicrobial-resistant strains. The in vivo virulence, genetic relatedness, and resistance mechanisms of these hypervirulent antimicrobial-resistant strains were also investigated. A total of 182 capsular type K1 K. pneumoniae strains were identified, including 18 antimicrobial-resistant strains. The 28-day mortality rate among the 18 cases caused by antimicrobial-resistant strains was significantly higher than that among 164 cases caused by antimicrobial-sensitive strains (50% vs. 10.4%, p < 0.001). Infection with antimicrobial-resistant strain independently increased the 28-day mortality risk. Most antimicrobial -resistant strains were not clonally related, and they exhibited high in vivo virulence in a mouse lethality experiment. The major resistance mechanisms involved the presence of β-lactamases and the overexpression of efflux pumps. In conclusion, hypervirulent antimicrobial-resistant capsular type K1 K. pneumoniae strains can predispose to a fatal outcome. These strains may represent an emerging threat to public health in Taiwan. Copyright © 2018. Published by Elsevier B.V.

Biosorption of Cadmium and Manganese Using Free Cells of Klebsiella sp. Isolated from Waste Water

PubMed Central

Hou, Yunnan; Cheng, Keke; Li, Zehua; Ma, Xiaohui; Wei, Yahong; Zhang, Lei; Wang, Yao

2015-01-01

In the present study, we evaluated a bacterium that was isolated from waste water for its ability to take up cadmium and manganese. The strain, identified both biochemically and by its 16S rRNA gene sequence as Klebsiella, was named Yangling I2 and was found to be highly resistant to heavy metals. Surface characterization of the bacterium via SEM revealed gross morphological changes, with cells appearing as biconcave discs after metal exposure rather than their typical rod shape. The effects of pH, temperature, heavy metal concentration, agitation and biomass concentration on the uptake of Cd(II) and Mn(II) was measured using atomic absorption spectrophotometry. The results showed that the biosorption was most affected by pH and incubation temperature, being maximized at pH 5.0 and 30°C, with absorption capacities of 170.4 and 114.1 mg/g for Cd(II) and Mn(II), respectively. Two models were investigated to compare the cells’ capacity for the biosorption of Cd and Mn, and the Langmuir model based on fuzzy linear regression was found to be close to the observed absorption curves and yield binding constants of 0.98 and 0.86 for Cd and Mn, respectively. This strain of Klebsiella has approximately ten times the absorption capacity reported for other strains and is promising for the removal of heavy metals from waste water. PMID:26505890

Extended-spectrum β-lactamase producing Enterobacteriaceae in bulk tank milk from German dairy farms.

PubMed

Odenthal, Sabrina; Akineden, Ömer; Usleber, Ewald

2016-12-05

Although the dairy farm environment is a known source of extended-spectrum β-lactamase (ESBL)-producing bacteria, surveillance data on ESBL in the milk production chain are still scarce. This study aimed at estimating the dimensions of the problem for public health and animal welfare by surveying ESBL-producing Enterobacteriaceae in raw bulk tank milk in Germany. Samples from 866 dairy farms, comprising about 1% of the total number of dairy farms in Germany, were first screened for presence of cefotaxime-resistant bacteria by selective enrichment. Suspect colonies were identified phenotypically and further characterized by biochemical and molecular methods, including analysis of resistance genes and clonal diversity in ESBL-producing isolates. Bulk tank milk from 82 (9.5%) farms yielded Enterobacteriaceae with confirmed ESBL-production. The most frequent ESBL-producing species was Escherichia coli (75.6%), followed by Citrobacter spp. (9.6%), Enterobacter cloacae (6.1%), and Klebsiella oxytoca (3.7%), a few isolates belonged to other species within the genera Hafnia, Raoutella and Serratia. The majority of isolates (95.1%) harbored the β-lactamase blaCTX-M gene, which has gained increased importance among ESBL-producing strains worldwide; the CTX-M group 1 was found to be the dominating (88.4%) phylogenetic group. All ESBL-positive Escherichia coli isolates were clonally heterogeneous, as determined by pulsed-field gel electrophoresis. The results from this survey demonstrate that ESBL-producing bacteria are distributed widely in the dairy farm environment in Germany. Therefore, raw milk is a potential source of exposure for the consumer, which is of increasing importance considering the trend of farmer-to-consumer direct marketing. Furthermore, dairy farm staff have an increased likelihood of exposure to ESBL-producing bacteria. Finally, ESBL-producing bacteria may also be transferred via waste milk to calves, thus further spreading antibiotic resistance in the farm environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Inhibitory effects of various essential oils and individual components against extended-spectrum beta-lactamase (ESBL) produced by Klebsiella pneumoniae and their chemical compositions.

PubMed

Orhan, Ilkay Erdogan; Ozcelik, Berrin; Kan, Yüksel; Kartal, Murat

2011-10-01

In the current study, in vitro inhibitory activity of several essential oils obtained from the cultivated plants, Foeniculum vulgare, Mentha piperita and M. spicata, Ocimum basilicum, Origanum majorana, O. onites, O. vulgare, Satureja cuneifolia, and a number of individual essential oil components of terpene and aromatic types were screened against 10 isolated strains of Klebsiella pneumoniae producing extended-spectrum beta-lactamase (ESBL) enzyme, which makes this microorganism quite resistant against the antibiotics: trimetoprime-sulfametoksazol, sulbactam-ampicilin, clavulonate-amoxicilin, ceftriaxon, cefepime, imipenem, ceftazidime, tobramicine, gentamisine, ofloxacin, and ciprofloksasin. All of the essential oils and the components exerted a remarkable inhibition ranging between 32 and 64 μg/mL against all of these strains as strong as the references (ampicilin and oflaxocin) inhibiting at 32 μg/mL. Besides, chemical compositions of the essential oils were elucidated by gas chromatography-mass spectrometry (GC-MS). The essential oils and the pure components widely found in essential oils screened herein have shown remarkable inhibition against ESBL-producing K. pneumoniae strains, which leads to the suggestion that they may be used as food preservatives for this purpose. Practical Application:  The essential oils obtained from Foeniculum vulgare, Mentha piperita and M. spicata, O.cimum basilicum, Origanum majorana, O. onites, O. vulgare, and Satureja cuneifolia as well as common essential oil components have shown notable inhibitory effects against 10 isolated strains of Klebsiella pneumoniae producing extended-spectrum beta-lactamase (ESBL) enzyme and they might be used as food preservative or ingredient. © 2011 Institute of Food Technologists®

Biological Treatment of Cyanide by Using
Klebsiella pneumoniae Species

PubMed Central

Bilkay, Isil Seyis

2016-01-01

Summary In this study, optimization conditions for cyanide biodegradation by Klebsiella pneumoniae strain were determined to be 25 °C, pH=7 and 150 rpm at the concentration of 0.5 mM potassium cyanide in the medium. Additionally, it was found that K. pneumoniae strain is not only able to degrade potassium cyanide, but also to degrade potassium hexacyanoferrate(II) trihydrate and sodium ferrocyanide decahydrate with the efficiencies of 85 and 87.5%, respectively. Furthermore, this strain degraded potassium cyanide in the presence of different ions such as magnesium, nickel, cobalt, iron, chromium, arsenic and zinc, in variable concentrations (0.1, 0.25 and 0.5 mM) and as a result the amount of the bacteria in the biodegradation media decreased with the increase of ion concentration. Lastly, it was also observed that sterile crude extract of K. pneumoniae strain degraded potassium cyanide on the fifth day of incubation. Based on these results, it is concluded that both culture and sterile crude extract of K. pnemoniae will be used in cyanide removal from different wastes. PMID:28115902

The effect of sub-inhibitory concentrations of rifaximin on urease production and on other virulence factors expressed by Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa and Staphylococcus aureus.

PubMed

Ricci, Annalisa; Coppo, Erika; Barbieri, Ramona; Debbia, Eugenio A; Marchese, Anna

2017-04-01

Rifaximin, a topical derivative of rifampin, inhibited urease production and other virulence factors at sub-MIC concentrations in strains involved in hepatic encephalopathy and the expression of methicillin resistance in Staphylococcus aureus. In particular, urease production was affected in all Proteus mirabilis and Klebsiella pneumoniae strains as well as in all tested Pseudomonas aeruginosa isolates. Other exotoxins, synthesized by P. aeruginosa, such as protease, gelatinase, lipase, lecithinase and DNAse were also not metabolized in the presence of rifaximin. This antibiotic inhibited pigment production in both P. aeruginosa and Chromobacterium violaceum, a biosensor control strain. Lastly, rifaximin affected haemolysin production in S. aureus and was able to restore cefoxitin susceptibility when the strain was cultured in the presence of sub-MICs of the drug. The present findings confirm and extend previous observations about the beneficial effects of rifaximin for the treatment of gastrointestinal diseases, since in this anatomic site, it reaches a large array of concentrations which prevents enterobacteria from thriving and/or producing their major virulence factors.

Colistin resistance associated with outer membrane protein change in Klebsiella pneumoniae and Enterobacter asburiae.

PubMed

Kádár, Béla; Kocsis, Béla; Tóth, Ákos; Kristóf, Katalin; Felső, Péter; Kocsis, Béla; Böddi, Katalin; Szabó, Dóra

2017-06-01

In this study, outer membrane proteins (OMPs) of colistin-resistant Klebsiella pneumoniae and Enterobacter asburiae were analyzed. One colistin-susceptible and three colistin-resistant K. pneumoniae sequence type 258 strains as well as one colistin-susceptible E. asburiae and its colistin-heteroresistant counterpart strain were involved in the study. OMP analysis of each strain was performed by microchip method. Matrix-assisted laser desorption ionization time of flight/mass spectrometry (MALDI-TOF/MS) investigation was carried out after separation of OMPs by two-dimensional gel electrophoresis and in-gel digestion. The MALDI-TOF/MS analysis of OMPs in the colistin-susceptible K. pneumoniae found 16 kDa proteins belonging to the LysM domain/BON superfamily, as well as DNA starvation proteins, whereas OmpX and OmpW were detected in the colistin-resistant counterpart strains. OmpC and OmpW were detected in the colistin-susceptible E. asburiae, whereas OmpA and OmpX were identified in the colistin-resistant counterpart. This study demonstrated that OMP differences were between colistin-susceptible and -resistant counterpart strains. The altered Gram-negative cell wall may contribute to acquired colistin resistance in Enterobacteriaceae.

Structural determination of the polysaccharide isolated from biofilms produced by a clinical strain of Klebsiella pneumoniae.

PubMed

Cescutti, Paola; De Benedetto, Gianluigi; Rizzo, Roberto

2016-07-22

Klebsiella pneumoniae are Gram negative opportunistic pathogens producing capsular (K) polysaccharides. Seventy-seven different K antigens have been described and they are the basis for K serotyping. Capsular polysaccharides are important virulence factors and have a relevant role for the structure of biofilm communities. Nevertheless, little information is available on the polysaccharides produced in biofilm matrices by Klebsiella spp. In the present study, a clinical isolate of Klebsiella pneumoniae was grown both on cellulose membranes deposited on agar plates, where it formed an adherent biofilm, and in liquid medium, where it formed floating biofilms (flocs). Extraction and purification of the polysaccharide fraction showed that only one main carbohydrate polymer was present in both adherent biofilms and flocs. Composition and linkage analysis, Smith degradation followed by ESI-MS, 1D and 2D NMR spectroscopy revealed that the polysaccharide belong to the type K24 and has the following structure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Draft Genome Sequences of blaKPC-Containing Enterobacter aerogenes, Citrobacter freundii, and Citrobacter koseri Strains

PubMed Central

Hazen, Tracy H.; Mettus, Roberta T.; McElheny, Christi L.; Bowler, Sarah L.

2018-01-01

ABSTRACT We report here the draft genome sequences of four blaKPC-containing bacteria identified as Klebsiella aerogenes, Citrobacter freundii, and Citrobacter koseri. Additionally, we report the draft genome sequence of a K. aerogenes strain that did not contain a blaKPC gene but was isolated from the patient who had the blaKPC-2-containing K. aerogenes strain. PMID:29472325

Draft Genome Sequences of blaKPC-Containing Enterobacter aerogenes, Citrobacter freundii, and Citrobacter koseri Strains.

PubMed

Hazen, Tracy H; Mettus, Roberta T; McElheny, Christi L; Bowler, Sarah L; Doi, Yohei; Rasko, David A

2018-02-22

We report here the draft genome sequences of four bla KPC -containing bacteria identified as Klebsiella aerogenes , Citrobacter freundii , and Citrobacter koseri Additionally, we report the draft genome sequence of a K. aerogenes strain that did not contain a bla KPC gene but was isolated from the patient who had the bla KPC-2 -containing K. aerogenes strain. Copyright © 2018 Hazen et al.

Rapid detection of carbapenemase-producing Klebsiella pneumoniae strains derived from blood cultures by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS).

PubMed

Sakarikou, Christina; Ciotti, Marco; Dolfa, Camilla; Angeletti, Silvia; Favalli, Cartesio

2017-03-08

Carbapenemase-producing Enterobacteriaceae (CPE), particularly carbapenemase-producing Klebsiella pneumoniae isolates, are important causative agents of nosocomial infections associated with significant mortality rates mostly in critical wards. The rapid detection and typing of these strains is critical either for surveillance purposes and to prevent outbreaks and optimize antibiotic therapy. In this study, the MALDI-TOF MS method was used to detect rapidly these isolates from blood cultures (BCs) and to obtain proteomic profiles enable to discriminate between carbapenemase-producing and non-carbapenemase-producing strains. Fifty-five K. pneumoniae strains were tested. Identification and carbapenemase-production detection assay using Ertapenem were performed both from bacterial pellets extracted directly from BCs flasks and from subcultures of these strains. For all isolates, a complete antimicrobial susceptibility testing and a genotypic characterization were performed. We found 100% agreement between the carbapenemase-producing profile generated by MALDI TOF MS and that obtained using conventional methods. The assay detected and discriminated different carbapenemase-producing K. pneumoniae isolates within 30 min to 3 h after incubation with Ertapenem. MALDI-TOF MS is a promising, rapid and economical method for the detection of carbapenemase-producing K. pneumoniae strains that could be successfully introduced into the routine diagnostic workflow of clinical microbiology laboratories.

Enterobacteriaceae Sepsis Outcome Programme annual report, 2013.

PubMed

Turnidge, John D; Gottlieb, Thomas; Mitchell, David H; Coombs, Geoffrey W; Daly, Denise A; Bell, Jan M

2014-12-31

The Australian Group on Antimicrobial Resistance performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric Gram-negative pathogens. The 2013 survey focussed for the first time on blood stream infections. Four thousand nine hundred and fifty-eight Enterobacteriaceae species were tested using commercial automated methods (Vitek® 2, BioMérieux; Phoenix™, BD). The results were analysed using Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints (January 2014). Of the key resistances, non-susceptibility to the third-generation cephalosporin, ceftriaxone, was found in 7.5%/7.5% (CLSI/EUCAST criteria respectively) of Escherichia coli; 6.3%/6.3% of Klebsiella pneumoniae, and 7.4%/7.4% of K. oxytoca. Non-susceptibility rates to ciprofloxacin were 10.3%/11.3% for E. coli, 4.6%/7.5% for K. pneumoniae, 0.6%/0.6% for K. oxytoca, and 3.6%/6.1% in Enterobacter cloacae. Resistance rates to piperacillin-tazobactam were 3.1%/6.2%, 4.2%/7.0%, 11.9% /12.6%, and 17.3% /22.2% for the same 4 species respectively. Fourteen isolates were shown to harbour a carbapenemase gene, 9 blaIMP, 3 blaKPC, and 2 blaNDM. This work is copyright. You may download, display, print and reproduce the whole or part of this work in unaltered form for your own personal use or, if you are part of an organisation, for internal use within your organisation, but only if you or your organisation do not use the reproduction for any commercial purpose and retain this copyright notice and all disclaimer notices as part of that reproduction. Apart from rights to use as permitted by the Copyright Act 1968 or allowed by this copyright notice, all other rights are reserved and you are not allowed to reproduce the whole or any part of this work in any way (electronic or otherwise) without first being given the specific written permission from the Commonwealth to do so. Requests and inquiries concerning reproduction and rights are to be sent to the Online, Services and External Relations Branch, Department of Health, GPO Box 9848, Canberra ACT 2601, or by email to copyright@health.gov.au.

[Results of a multicenter study investigating plasmid mediated colistin resistance genes (mcr-1 and mcr-2) in clinical Enterobacteriaceae ısolates from Turkey].

PubMed

Sarı, Ayşe Nur; Süzük, Serap; Karatuna, Onur; Öğünç, Dilara; Karakoç, Ayşe Esra; Çizmeci, Zeynep; Alışkan, Hikmet Eda; Cömert, Füsun; Bakıcı, Mustafa Zahir; Akpolat, Nezahat; Çilli, Fatma Feriha; Zer, Yasemin; Karataş, Aysel; Akgün Karapınar, Bahar; Bayramoğlu, Gülçin; Özdamar, Melda; Kalem, Fatma; Delialioğlu, Nuran; Aktaş, Elif; Yılmaz, Nisel; Gürcan, Şaban; Gülay, Zeynep

2017-07-01

Colistin is a polymyxin antibiotic which is considered as one of the last line agents against infections due to multidrug resistant or carbapenem resistant gram-negative pathogens. Colistin resistance is associated with chromosomal alterations which can usually cause mutations in genes coding specific two component regulator systems. The first plasmid-mediated colistin resistance gene, mcr-1 was described in Escherichia coli and Klebsiella pneumoniae isolates in December 2015 and followed by another plasmid-mediated colistin resistance gene mcr-2 in 2016. The rapid and interspecies dissemination of plasmid-mediated resistance mechanisms through horizontal gene transfer, have made these genes considerably threatening. After the first reports, although mcr-1/mcr-2 producing Enterobacteriaceae isolates have been reported from many countries, there have been no reports from Turkey. Thus, the aim of this study was to investigate the presence of mcr-1/mcr-2 in clinical Enterobacteriaceae isolates from different parts of our country. A total of 329 Enterobacteriaceae isolates from 22 laboratories were collected which were isolated between March, 2015 and February, 2016. mcr-1/mcr-2 were investigated by polymerase chain reaction during February-March, 2016. Two hundred and seventeen of Klebsiella pneumoniae (66%), 75 of Salmonella spp. (22.8%), 31 of Esherichia coli (9.4%), 3 of Enterobacter cloacae (0.9%), 2 of Klebsiella oxytoca (0.6%) and 1 of Enterobacter aerogenes (0.3%) isolates were included to the study. Agarose gel electrophoresis results of PCR studies have shown expected band sizes for positive control isolates as 309 bp for mcr-1 and 567 bp for mcr-2. However, the presence of mcr-1/mcr-2 genes was not detected among the tested study isolates of Enterobacteriaceae. Although mcr-1/mcr-2 were not detected in our study isolates, it is highly important to understand the mechanism of resistance dissemination and determine the resistant isolates by considering that colistin is a last-line antibiotic against infections of multidrug or carbapenem resistant gram-negative bacteria. Thus, it is suggested that these mechanisms should be followed-up in both clinical and non-clinical (e.g. isolates from food animals, raw meats and environment) isolates of special populations.

Antibacterial activity of local herbs collected from Murree (Pakistan) against multi-drug resistant Klebsiella pneumonae, E. coli and methyciline resistant Staphylococcus aureus.

PubMed

Mansoor, Qaisar; Shaheen, Saira; Javed, Uzma; Shaheen, Uzma; Iqrar, Irum; Ismail, Muhammad

2013-07-01

Exploring healing power in plants emerged in prehistory of human civilization. Sustaining good health has been achieved over the millions of years by use of plant products in various traditional sockets. A major contribution of medicinal plants to health care systems is their limitless possession of bioactive components that stimulate explicit physiological actions. Luckily Pakistan is blessed with huge reservoir of plants with medicinal potential and some of them; we focused in this study for their medicinal importance.In this study we checked the antibacterial activity inherent in Ricinus communis, Solanum nigrum, Dodonaea viscose and Berberis lyceum extracts for multidrug resistance bacterial strains Klebsiella pneumonae, E. coli and methyciline resistant Staphylococcus aureus. MRSA showed sensitivity for Ricinus communis. Multidrug resistant Klebsiella pneumonae was sensitive with Pine roxburgii and Ricinus communis but weakly susceptible for Solanum nigrum. Multidrug resistant E. coli was resistant to all plant extracts. Treatment of severe infections caused by the bacterial strains used in this study with Ricinus communis, Pine roxburgii and Solanum nigrum can lower the undesired side effects of synthetic medicine and also reduce the economic burden.

Plasmid Dynamics in KPC-Positive Klebsiella pneumoniae during Long-Term Patient Colonization.

PubMed

Conlan, Sean; Park, Morgan; Deming, Clayton; Thomas, Pamela J; Young, Alice C; Coleman, Holly; Sison, Christina; Weingarten, Rebecca A; Lau, Anna F; Dekker, John P; Palmore, Tara N; Frank, Karen M; Segre, Julia A

2016-06-28

Carbapenem-resistant Klebsiella pneumoniae strains are formidable hospital pathogens that pose a serious threat to patients around the globe due to a rising incidence in health care facilities, high mortality rates associated with infection, and potential to spread antibiotic resistance to other bacterial species, such as Escherichia coli Over 6 months in 2011, 17 patients at the National Institutes of Health (NIH) Clinical Center became colonized with a highly virulent, transmissible carbapenem-resistant strain of K. pneumoniae Our real-time genomic sequencing tracked patient-to-patient routes of transmission and informed epidemiologists' actions to monitor and control this outbreak. Two of these patients remained colonized with carbapenemase-producing organisms for at least 2 to 4 years, providing the opportunity to undertake a focused genomic study of long-term colonization with antibiotic-resistant bacteria. Whole-genome sequencing studies shed light on the underlying complex microbial colonization, including mixed or evolving bacterial populations and gain or loss of plasmids. Isolates from NIH patient 15 showed complex plasmid rearrangements, leaving the chromosome and the blaKPC-carrying plasmid intact but rearranging the two other plasmids of this outbreak strain. NIH patient 16 has shown continuous colonization with blaKPC-positive organisms across multiple time points spanning 2011 to 2015. Genomic studies defined a complex pattern of succession and plasmid transmission across two different K. pneumoniae sequence types and an E. coli isolate. These findings demonstrate the utility of genomic methods for understanding strain succession, genome plasticity, and long-term carriage of antibiotic-resistant organisms. In 2011, the NIH Clinical Center had a nosocomial outbreak involving 19 patients who became colonized or infected with blaKPC-positive Klebsiella pneumoniae Patients who have intestinal colonization with blaKPC-positive K. pneumoniae are at risk for developing infections that are difficult or nearly impossible to treat with existing antibiotic options. Two of those patients remained colonized with blaKPC-positive Klebsiella pneumoniae for over a year, leading to the initiation of a detailed genomic analysis exploring mixed colonization, plasmid recombination, and plasmid diversification. Whole-genome sequence analysis identified a variety of changes, both subtle and large, in the blaKPC-positive organisms. Long-term colonization of patients with blaKPC-positive Klebsiella pneumoniae creates new opportunities for horizontal gene transfer of plasmids encoding antibiotic resistance genes and poses complications for the delivery of health care. Copyright © 2016 Conlan et al.

Phosphate solubilization and chromium (VI) remediation potential of Klebsiella sp. strain CPSB4 isolated from the chromium contaminated agricultural soil.

PubMed

Gupta, Pratishtha; Kumar, Vipin; Usmani, Zeba; Rani, Rupa; Chandra, Avantika

2018-02-01

In this study, an effort was made to identify an efficient phosphate solubilizing bacterial strain from chromium contaminated agricultural soils. Based on the formation of a solubilized halo around the colonies on Pikovskaya's agar amended with chromium (VI), 10 strains were initially screened out. Out of 10, strain CPSB4, which showed significantly high solubilization zone at different chromium concentrations, was selected for further study. The strain CPSB4 showed significant plant growth promotion traits with chromium (VI) stress under in-vitro conditions in broth. The plant growth promotion activities of the strain decreased regularly, but were not completely lost with the increase in concentration of chromium up to 200 mg L -1 . On subjected to FT-IR analysis, the presence of the functional group, indicating the organic acid aiding in phosphate solubilization was identified. At an optimal temperature of 30  ° C and pH 7.0, the strain showed around 93% chromium (VI) reduction under in-vitro conditions in broth study. In soil condition, the maximum chromium (VI) reduction obtained was 95% under in-vitro conditions. The strain CPSB4 was identified as Klebsiella sp. on the basis of morphological, biochemical and 16S rRNA gene sequencing. This study shows that the diverse role of the bacterial strain CPSB4 would be useful in the chromium contaminated soil as a good bioremediation and plant growth promoting agent as well. Copyright © 2017 Elsevier Ltd. All rights reserved.

Interactions of β-Lactamases with Sanfetrinem (GV 104326) Compared to Those with Imipenem and with Oral β-Lactams

PubMed Central

Babini, Gioia S.; Yuan, Meifang; Livermore, David M.

1998-01-01

Sanfetrinem is a trinem β-lactam which can be administered orally as a hexatil ester. We examined whether its β-lactamase interactions resembled those of the available carbapenems, i.e., stable to AmpC and extended-spectrum β-lactamases but labile to class B and functional group 2f enzymes. The comparator drugs were imipenem, oral cephalosporins, and amoxicillin. MICs were determined for β-lactamase expression variants, and hydrolysis was examined directly with representative enzymes. Sanfetrinem was a weak inducer of AmpC β-lactamases below the MIC and had slight lability, with a kcat of 0.00033 s−1 for the Enterobacter cloacae enzyme. Its MICs for AmpC-derepressed E. cloacae and Citrobacter freundii were 4 to 8 μg/ml, compared with MICs of 0.12 to 2 μg/ml for AmpC-inducible and -basal strains; MICs for AmpC-derepressed Serratia marcescens and Morganella morganii were not raised. Cefixime and cefpodoxime were more labile than sanfetrinem to the E. cloacae AmpC enzyme, and AmpC-derepressed mutants showed much greater resistance; imipenem was more stable and retained full activity against derepressed mutants. Like imipenem, sanfetrinem was stable to TEM-1 and TEM-10 enzymes and retained full activity against isolates and transconjugants with various extended-spectrum TEM and SHV enzymes, whereas these organisms were resistant to cefixime and cefpodoxime. Sanfetrinem, like imipenem and cefixime but unlike cefpodoxime, also retained activity against Proteus vulgaris and Klebsiella oxytoca strains that hyperproduced potent chromosomal class A β-lactamases. Functional group 2f enzymes, including Sme-1, NMC-A, and an unnamed enzyme from Acinetobacter spp., increased the sanfetrinem MICs by up to 64-fold. These enzymes also compromised the activities of imipenem and amoxicillin but not those of the cephalosporins. The hydrolysis of sanfetrinem was examined with a purified Sme-1 enzyme, and biphasic kinetics were found. Finally, zinc β-lactamases, including IMP-1 and the L1 enzyme of Stenotrophomonas maltophilia, conferred resistance to sanfetrinem and all other β-lactams tested, and hydrolysis was confirmed with the IMP-1 enzyme. We conclude that sanfetrinem has β-lactamase interactions similar to those of the available carbapenems except that it is a weaker inducer of AmpC types, with some tendency to select derepressed mutants, unlike imipenem and meropenem. PMID:9593145

Rapid Induction of High-Level Carbapenem Resistance in Heteroresistant KPC-Producing Klebsiella pneumoniae

PubMed Central

Adams-Sapper, Sheila; Nolen, Shantell; Donzelli, Grace Fox; Lal, Mallika; Chen, Kunihiko; Justo da Silva, Livia Helena; Moreira, Beatriz M.

2015-01-01

Enterobacteriaceae strains producing the Klebsiella pneumoniae carbapenemase (KPC) have disseminated worldwide, causing an urgent threat to public health. KPC-producing strains often exhibit low-level carbapenem resistance, which may be missed by automated clinical detection systems. In this study, eight Klebsiella pneumoniae strains with heterogeneous resistance to imipenem were used to elucidate the factors leading from imipenem susceptibility to high-level resistance as defined by clinical laboratory testing standards. Time-kill analysis with an inoculum as low as 3 × 106 CFU/ml and concentrations of imipenem 8- and 16-fold higher than the MIC resulted in the initial killing of 99.9% of the population. However, full recovery of the population occurred by 20 h of incubation in the same drug concentrations. Population profiles showed that recovery was mediated by a heteroresistant subpopulation at a frequency of 2 × 10−7 to 3 × 10−6. Samples selected 2 h after exposure to imipenem were as susceptible as the unexposed parental strain and produced the major outer membrane porin OmpK36. However, between 4 to 8 h after exposure, OmpK36 became absent, and the imipenem MIC increased at least 32-fold. Individual colonies isolated from cultures after 20 h of exposure revealed both susceptible and resistant subpopulations. Once induced, however, the high-level imipenem resistance was maintained, and OmpK36 remained unexpressed even without continued carbapenem exposure. This study demonstrates the essential coordination between blaKPC and ompK36 expression mediating high-level imipenem resistance from a population of bacteria that initially exhibits a carbapenem-susceptibility phenotype. PMID:25801565

Rapid label-free identification of Klebsiella pneumoniae antibiotic resistant strains by the drop-coating deposition surface-enhanced Raman scattering method

NASA Astrophysics Data System (ADS)

Cheong, Youjin; Kim, Young Jin; Kang, Heeyoon; Choi, Samjin; Lee, Hee Joo

2017-08-01

Although many methodologies have been developed to identify unknown bacteria, bacterial identification in clinical microbiology remains a complex and time-consuming procedure. To address this problem, we developed a label-free method for rapidly identifying clinically relevant multilocus sequencing typing-verified quinolone-resistant Klebsiella pneumoniae strains. We also applied the method to identify three strains from colony samples, ATCC70063 (control), ST11 and ST15; these are the prevalent quinolone-resistant K. pneumoniae strains in East Asia. The colonies were identified using a drop-coating deposition surface-enhanced Raman scattering (DCD-SERS) procedure coupled with a multivariate statistical method. Our workflow exhibited an enhancement factor of 11.3 × 106 to Raman intensities, high reproducibility (relative standard deviation of 7.4%), and a sensitive limit of detection (100 pM rhodamine 6G), with a correlation coefficient of 0.98. All quinolone-resistant K. pneumoniae strains showed similar spectral Raman shifts (high correlations) regardless of bacterial type, as well as different Raman vibrational modes compared to Escherichia coli strains. Our proposed DCD-SERS procedure coupled with the multivariate statistics-based identification method achieved excellent performance in discriminating similar microbes from one another and also in subtyping of K. pneumoniae strains. Therefore, our label-free DCD-SERS procedure coupled with the computational decision supporting method is a potentially useful method for the rapid identification of clinically relevant K. pneumoniae strains.

Comparative Genomics of Klebsiella pneumoniae Strains with Different Antibiotic Resistance Profiles▿†

PubMed Central

Kumar, Vinod; Sun, Peng; Vamathevan, Jessica; Li, Yong; Ingraham, Karen; Palmer, Leslie; Huang, Jianzhong; Brown, James R.

2011-01-01

There is a global emergence of multidrug-resistant (MDR) strains of Klebsiella pneumoniae, a Gram-negative enteric bacterium that causes nosocomial and urinary tract infections. While the epidemiology of K. pneumoniae strains and occurrences of specific antibiotic resistance genes, such as plasmid-borne extended-spectrum β-lactamases (ESBLs), have been extensively studied, only four complete genomes of K. pneumoniae are available. To better understand the multidrug resistance factors in K. pneumoniae, we determined by pyrosequencing the nearly complete genome DNA sequences of two strains with disparate antibiotic resistance profiles, broadly drug-susceptible strain JH1 and strain 1162281, which is resistant to multiple clinically used antibiotics, including extended-spectrum β-lactams, fluoroquinolones, aminoglycosides, trimethoprim, and sulfamethoxazoles. Comparative genomic analysis of JH1, 1162281, and other published K. pneumoniae genomes revealed a core set of 3,631 conserved orthologous proteins, which were used for reconstruction of whole-genome phylogenetic trees. The close evolutionary relationship between JH1 and 1162281 relative to other K. pneumoniae strains suggests that a large component of the genetic and phenotypic diversity of clinical isolates is due to horizontal gene transfer. Using curated lists of over 400 antibiotic resistance genes, we identified all of the elements that differentiated the antibiotic profile of MDR strain 1162281 from that of susceptible strain JH1, such as the presence of additional efflux pumps, ESBLs, and multiple mechanisms of fluoroquinolone resistance. Our study adds new and significant DNA sequence data on K. pneumoniae strains and demonstrates the value of whole-genome sequencing in characterizing multidrug resistance in clinical isolates. PMID:21746949

Distribution of Extended-Spectrum β-Lactamases, AmpC β-Lactamases, and Carbapenemases among Enterobacteriaceae Isolates Causing Intra-Abdominal Infections in the Asia-Pacific Region: Results of the Study for Monitoring Antimicrobial Resistance Trends (SMART)

PubMed Central

Sheng, Wang-Huei; Badal, Robert E.

2013-01-01

The increasing trend of β-lactam resistance among Enterobacteriaceae is a worldwide threat. Enterobacteriaceae isolates causing intra-abdominal infections (IAI) from the Study for Monitoring Antimicrobial Resistance Trends (SMART) collected in 2008 and 2009 from the Asia-Pacific region were investigated. Detection of extended-spectrum β-lactamases (ESBLs), AmpC β-lactamases, and carbapenemases was performed by multiplex PCR. A total of 699 Enterobacteriaceae isolates with positive genotypic results, included Escherichia coli (n = 443), Klebsiella pneumoniae (n = 187), Enterobacter cloacae (n = 45), Klebsiella oxytoca (n = 9), Citrobacter freundii (n = 5), Proteus mirabilis (n = 3), Enterobacter aerogenes (n = 2), Morganella morganii (n = 2), and one each of Enterobacter asburiae, Proteus vulgaris, and Providencia rettgeri were analyzed. Nearly 20% of these β-lactamase-producing Enterobacteriaceae isolates were from community-associated IAI. CTX-M (588 isolates, including 428 [72.8%] with CTX-M-15) was the most common ESBL, followed by SHV (n = 59) and TEM (n = 4). CMY (n = 110, including 102 [92.7%] with CMY-2) was the most common AmpC β-lactamase, followed by DHA (n = 46) and ACT/MIR (n = 40). NDM (n = 65, including 62 [95.4%] with NDM-1) was the most common carbapenemase, followed by IMP (n = 7) and OXA (n = 7). Isolates from hospital-associated IAI had more complicated β-lactamase combinations than isolates from the community. Carbapenemases were all exclusively detected in Enterobacteriaceae isolates from India, except that IMP β-lactamases were also detected in Philippines and Australia. CTX-M β-lactamases were the predominant ESBLs produced by Enterobacteriaceae causing IAI in the Asia-Pacific region. Emergence of CTX-M-15-, CMY-2-, and NDM-1-producing Enterobacteriaceae isolates is of major concern and highlights the need for further surveillance in this area. PMID:23587958

Extended-spectrum beta-lactamase- and carbapenemase-producing Enterobacteriaceae among Ethiopian children

PubMed Central

Legese, Melese Hailu; Weldearegay, Gebru Mulugeta; Asrat, Daniel

2017-01-01

Background Infections by extended-spectrum beta-lactamase- (ESBL) and carbapenem-resistant Enterobacteriaceae (CRE) are an emerging problem in children nowadays. Hence, the aim of this study was to determine the prevalence of ESBL- and carbapenemase-producing Enterobacteriaceae among children suspected of septicemia and urinary tract infections (UTIs). Methods A cross-sectional study was conducted from January to March 2014. A total of 322 study participants suspected of septicemia and UTIs were recruited. All blood and urine samples were cultured on blood and MacConkey agar. All positive cultures were characterized by colony morphology, Gram stain, and standard biochemical tests. Antimicrobial susceptibility test was performed on Muller-Hinton agar using disk diffusion. ESBL was detected using combination disk and double-disk synergy methods, and the results were compared. Carbapenemase was detected by modified Hodge method using meropenem. Data were analyzed using SPSS version 20. Results The overall prevalence of ESBL- and carbapenemase-producing Enterobacteriaceae was 78.57% (n=22/28) and 12.12%, respectively. Among the Enterobacteriaceae tested, Klebsiella pneumoniae (84.2%, n=16/19), Escherichia coli (100%, n=5/5), and Klebsiella oxytoca (100%, n=1/1) were positive for ESBL. Double-disk synergy method showed 90.9% sensitivity, 66.7% specificity, 95.2% positive predictive value, and 50% negative predictive value. Carbapenemase-producing Enterobacteriaceae were K. pneumoniae (9.09%, n=3/33) and Morganella morganii (3.03%, n=1/33). Conclusion Screening Enterobacteriaceae for ESBL production is essential for better antibiotics selection and preventing its further emergence and spread. In resource-limited settings, double-disk synergy method can be implemented for screening and confirming ESBL production. Moreover, occurrence of CRE in countries where no carbapenems are sold is worrying microbiologists as well as clinicians. Hence, identifying factors that induce carbapenemase production in the absence of carbapenems prescription is essential for control of CRE dissemination within the community. PMID:28182124

Outbreak of Ceftazidime-Resistant Klebsiella pneumoniae in a Pediatric Hospital in Warsaw, Poland: Clonal Spread of the TEM-47 Extended-Spectrum β-Lactamase (ESBL)-Producing Strain and Transfer of a Plasmid Carrying the SHV-5-Like ESBL-Encoding Gene

PubMed Central

Gniadkowski, Marek; Pałucha, Andrzej; Grzesiowski, Paweł; Hryniewicz, Waleria

1998-01-01

In 1996 a large, 300-bed pediatric hospital in Warsaw, Poland, started a program of monitoring infections caused by extended-spectrum β-lactamase (ESBL)-producing microorganisms. Over the first 3-month period eight Klebsiella pneumoniae isolates were identified as being resistant to ceftazidime. Six of these were found to produce the TEM-47 ESBL, which we first described in a K. pneumoniae strain recovered a year before in a pediatric hospital in Łódź, Poland, which is 140 km from Warsaw. Typing results revealed a very close relatedness among all these isolates, which suggested that the clonal outbreak in Warsaw was caused by a strain possibly imported from Łódź. The remaining two isolates expressed the SHV-5-like ESBL, which resulted from the horizontal transfer of a plasmid carrying the blaSHV gene between nonrelated strains. The data presented here exemplify the complexity of the epidemiological situation concerning ESBL producers typical for large Polish hospitals, in which no ESBL-monitoring programs were in place prior to 1995. PMID:9835494

Isolation and Characterization of Aquatic-Borne Klebsiella pneumoniae from Tropical Estuaries in Malaysia

PubMed Central

Barati, Anis; Ghaderpour, Aziz; Chew, Li Lee; Bong, Chui Wei; Thong, Kwai Lin; Chong, Ving Ching; Chai, Lay Ching

2016-01-01

Klebsiella pneumoniae is an opportunistic pathogen that is responsible for causing nosocomial and community-acquired infections. Despite its common presence in soil and aquatic environments, the virulence potential of K. pneumoniae isolates of environmental origin is largely unknown. Hence, in this study, K. pneumoniae isolated from the estuarine waters and sediments of the Matang mangrove estuary were screened for potential virulence characteristics: antibiotic susceptibility, morphotype on Congo red agar, biofilm formation, presence of exopolysaccharide and capsule, possession of virulence genes (fimH, magA, ugE, wabG and rmpA) and their genomic fingerprints. A total of 55 strains of K. pneumoniae were isolated from both human-distributed sites (located along Sangga Besar River) and control sites (located along Selinsing River) where less human activity was observed, indicated that K. pneumoniae is ubiquitous in the environment. However, the detection of potentially virulent strains at the downstream of Kuala Sepetang village has suggested an anthropogenic contamination source. In conclusion, the findings from this study indicate that the Matang mangrove estuary could harbor potentially pathogenic K. pneumoniae with risk to public health. More studies are required to compare the environmental K. pneumoniae strains with the community-acquired K. pneumoniae strains. PMID:27092516

Adaptive laboratory evolution of Klebsiella pneumoniae for improving 2,3-butanediol production

PubMed Central

Li, Hongbiao; Zhang, Genlin; Dang, Yanyan

2016-01-01

ABSTRACT Microbial production of 2,3-butanediol is limited by the toxic components in the lignocellulose hydrolysate. To improve the 2,3-butanediol production via Klebsiella pneumoniae from cotton stalk hydrolysate, a method coupling a high tolerance of strain and detoxification of the hydrolysate was thus investigated in this study. The strain tolerance of K. pneumoniae to the cotton stalk hydrolysate was improved via an adaptive laboratory evolution, which involved a stepwise increase in the hydrolysate concentration in the medium. Compared with the initial strain, the resulting strain increased the biomass 3.2-fold in a medium of 20 g/L hydrolysate and produced 10.45 g/L of 2,3-butanediol at an optimal concentration of 60 g/L hydrolysate. After detoxification of cotton stalk hydrolysate, the cell metabolism of K. pneumoniae was further promoted, and the 2,3-butanediol production increased by 1.2 folds. Using fed-batch fermentation, the concentration of 2,3-butanediol reached 35.5 g/L with a yield of 0.43 g/g. The results demonstrated that the bioconversion of low-cost cotton stalk hydrolysate into 2,3-butanediol improves the economics of microbial 2,3-butanediol production. PMID:27442598

Nitrogen starvation affects bacterial adhesion to soil

PubMed Central

Borges, Maria Tereza; Nascimento, Antônio Galvão; Rocha, Ulisses Nunes; Tótola, Marcos Rogério

2008-01-01

One of the main factors limiting the bioremediation of subsoil environments based on bioaugmentation is the transport of selected microorganisms to the contaminated zones. The characterization of the physiological responses of the inoculated microorganisms to starvation, especially the evaluation of characteristics that affect the adhesion of the cells to soil particles, is fundamental to anticipate the success or failure of bioaugmentation. The objective of this study was to investigate the effect of nitrogen starvation on cell surface hydrophobicity and cell adhesion to soil particles by bacterial strains previously characterized as able to use benzene, toluene or xilenes as carbon and energy sources. The strains LBBMA 18-T (non-identified), Arthrobacter aurescens LBBMA 98, Arthrobacter oxydans LBBMA 201, and Klebsiella sp. LBBMA 204–1 were used in the experiments. Cultivation of the cells in nitrogen-deficient medium caused a significant reduction of the adhesion to soil particles by all the four strains. Nitrogen starvation also reduced significantly the strength of cell adhesion to the soil particles, except for Klebsiella sp. LBBMA 204–1. Two of the four strains showed significant reduction in cell surface hydrophobicity. It is inferred that the efficiency of bacterial transport through soils might be potentially increased by nitrogen starvation. PMID:24031246

Production of a novel bioflocculant MNXY1 by Klebsiella pneumoniae strain NY1 and application in precipitation of cyanobacteria and municipal wastewater treatment

PubMed Central

Nie, M.; Yin, X.; Jia, J.; Wang, Y.; Liu, S.; Shen, Q.; Li, P.; Wang, Z.

2015-01-01

Aims To isolate and characterize the novel bioflocculant-producing bacteria, to optimize the bioflocculant production and evaluate its potential applications. Methods and Results Klebsiella pneumoniae strain NY1, a bacterium that produces a novel bioflocculant (MNXY1), was selected on the chemically defined media. It was classified according to the 16S rRNA gene sequence, morphological and microscopic characteristics. MNXY1 was characterized to contain 26% protein and 66% total sugar. The constituent sugar monomers of MNXY1, revealed by NMR analysis, are glucose, galactose and quinovose. Favorable culture conditions for MNXY1 production were determined. Strain NY1 produces a high level (14.9 g l−1) of MNXY1. MNXY1 is thermostable and tolerant to the extreme pH. It precipitated 54% of cyanobacteria from laboratory culture and 72% of the total suspended solids from raw wastewater. Conclusions Strain NY1 was identified to produce a novel bioflocculant MNXY1. The outstanding performance of MNXY1 in practical applications and its availability in copious amounts make it attractive for further investigation and development for industrial scale applications. PMID:21679283

Outer-membrane translocation of bulky small molecules by passive diffusion

PubMed Central

van den Berg, Bert; Prathyusha Bhamidimarri, Satya; Dahyabhai Prajapati, Jigneshkumar; Kleinekathöfer, Ulrich; Winterhalter, Mathias

2015-01-01

The outer membrane (OM) of gram-negative bacteria forms a protective layer around the cell that serves as a permeability barrier to prevent unrestricted access of noxious substances. The permeability barrier of the OM results partly from the limited pore diameters of OM diffusion channels. As a consequence, there is an “OM size-exclusion limit,” and the uptake of bulky molecules with molecular masses of more than ∼600 Da is thought to be mediated by TonB-dependent, active transporters. Intriguingly, the OM protein CymA from Klebsiella oxytoca does not depend on TonB but nevertheless mediates efficient OM passage of cyclodextrins with diameters of up to ∼15 Å. Here we show, by using X-ray crystallography, molecular dynamics simulations, and single-channel electrophysiology, that CymA forms a monomeric 14-stranded β-barrel with a large pore that is occluded on the periplasmic side by the N-terminal 15 residues of the protein. Representing a previously unidentified paradigm in OM transport, CymA mediates the passive diffusion of bulky molecules via an elegant transport mechanism in which a mobile element formed by the N terminus acts as a ligand-expelled gate to preserve the permeability barrier of the OM. PMID:26015567

Effect of the oxidation rate and Fe(II) state on microbial nitrate-dependent Fe(III) mineral formation

USGS Publications Warehouse

Senko, John M.; Dewers , Thomas A.; Krumholz, Lee R.

2005-01-01

A nitrate-dependent Fe(II)-oxidizing bacterium was isolated and used to evaluate whether Fe(II) chemical form or oxidation rate had an effect on the mineralogy of biogenic Fe(III) (hydr)oxides resulting from nitrate-dependent Fe(II) oxidation. The isolate (designated FW33AN) had 99% 16S rRNA sequence similarity to Klebsiella oxytoca. FW33AN produced Fe(III) (hydr)oxides by oxidation of soluble Fe(II) [Fe(II)sol] or FeS under nitrate-reducing conditions. Based on X-ray diffraction (XRD) analysis, Fe(III) (hydr)oxide produced by oxidation of FeS was shown to be amorphous, while oxidation of Fe(II)sol yielded goethite. The rate of Fe(II) oxidation was then manipulated by incubating various cell concentrations of FW33AN with Fe(II)sol and nitrate. Characterization of products revealed that as Fe(II) oxidation rates slowed, a stronger goethite signal was observed by XRD and a larger proportion of Fe(III) was in the crystalline fraction. Since the mineralogy of Fe(III) (hydr)oxides may control the extent of subsequent Fe(III) reduction, the variables we identify here may have an effect on the biogeochemical cycling of Fe in anoxic ecosystems.

Population dynamics of bacteria associated with different strains of the pine wood nematode Bursaphelenchus xylophilus after inoculation in maritime pine (Pinus pinaster).

PubMed

Roriz, Mariana; Santos, Carla; Vasconcelos, Marta W

2011-08-01

For a long time it was thought that Bursaphelenchus xylophilus was the only agent of the pine wilt disease. Recently, it was discovered that there are bacteria associated with the nematodes that contribute to the pathogenesis of this disease, mainly through the release of toxins that promote the death of the pines. Among the species most commonly found, are bacteria belonging to the Bacillus, Pantoea, Pseudomonas and Xanthomonas genera. The main objective of this work was to study the effect of inoculation of maritime pine (Pinus pinaster) with four different nematode isolates, in the bacterial population of nematodes and trees, at different stages of disease progression. The monitoring of progression of disease symptoms was also recorded. Also, the identification of bacteria isolated from the xylem of trees and the surface of nematodes was performed by classical identification methods, by the API20E identification system and by sequencing of bacterial DNA. The results showed that for the symptoms progression, the most striking difference was observed for the pines inoculated with the avirulent isolate, C14-5, which led to a slower and less severe aggravation of symptoms than in pines inoculated with the virulent isolates. In general, it was found that bacterial population, inside the tree, increased with disease progression. A superior bacterial quantity was isolated from pines inoculated with the nematode isolates HF and 20, and, comparatively, few bacteria were isolated from pines inoculated with the avirulent isolate. The identification system API20E was insufficient in the identification of bacterial species; Enterobacter cloacae species was identified in 79% of the isolated bacterial colonies and seven of these colonies could not be identified by this method. Molecular identification methods, through bacterial DNA sequencing, allowed a more reliable identification: eleven different bacterial species within the Bacillus, Citrobacter, Enterobacter, Escherichia, Klebsiella, Paenibacillus, Pantoea and Terribacillus genera were identified. General bacterial diversity increased with the progression of the disease. Bacillus spp. were predominant at the earlier stage of disease progression and Klebsiella oxytoca at the later stages. Furthermore, bacterial species isolated from the surface of nematodes were similar to those isolated from the xylem of pines. In the present work new bacterial species were identified which have never been reported before in this type of study and may be associated with their geographical origin (Portugal). P. pinaster, the pine species used in this study, was different from those commonly grown in Japan and China. Furthermore, it was the first time that bacteria were isolated and identified from an avirulent pine wood nematode isolate. Copyright © 2011 Elsevier Inc. All rights reserved.

Synergistic activity of synthetic N-terminal peptide of human lactoferrin in combination with various antibiotics against carbapenem-resistant Klebsiella pneumoniae strains.

PubMed

Morici, P; Florio, W; Rizzato, C; Ghelardi, E; Tavanti, A; Rossolini, G M; Lupetti, A

2017-10-01

The spread of multi-drug resistant (MDR) Klebsiella pneumoniae strains producing carbapenemases points to a pressing need for new antibacterial agents. To this end, the in-vitro antibacterial activity of a synthetic N-terminal peptide of human lactoferrin, further referred to as hLF1-11, was evaluated against K. pneumoniae strains harboring different carbapenemase genes (i.e. OXA-48, KPC-2, KPC-3, VIM-1), with different susceptibility to colistin and other antibiotics, alone or in combination with conventional antibiotics (gentamicin, tigecycline, rifampicin, clindamycin, and clarithromycin). An antimicrobial peptide susceptibility assay was used to assess the bactericidal activity of hLF1-11 against the different K. pneumoniae strains tested. The synergistic activity was evaluated by a checkerboard titration method, and the fractional inhibitory concentration (FIC) index was calculated for the various combinations. hLF1-11 was more efficient in killing a K. pneumoniae strain susceptible to most antimicrobials (including colistin) than a colistin-susceptible strain and a colistin-resistant MDR K. pneumoniae strain. In addition, hLF1-11 exhibited a synergistic effect with the tested antibiotics against MDR K. pneumoniae strains. The results of this study indicate that resistance to hLF1-11 and colistin are not strictly associated, and suggest an hLF1-11-induced sensitizing effect of K. pneumoniae to antibiotics, especially to hydrophobic antibiotics, which are normally not effective on Gram-negative bacteria. Altogether, these data indicate that hLF1-11 in combination with antibiotics is a promising candidate to treat infections caused by MDR-K. pneumoniae strains.

Chemical composition and antibacterial activity of Lavandula coronopifolia essential oil against antibiotic-resistant bacteria.

PubMed

Ait Said, L; Zahlane, K; Ghalbane, I; El Messoussi, S; Romane, A; Cavaleiro, C; Salgueiro, L

2015-01-01

The aim of this study was to analyse the composition of the essential oil (EO) of Lavandula coronopifolia from Morocco and to evaluate its in vitro antibacterial activity against antibiotic-resistant bacteria isolated from clinical infections. The antimicrobial activity was assessed by a broth micro-well dilution method using multiresistant clinical isolates of 11 pathogenic bacteria: Klebsiella pneumoniae subsp. pneumoniae, Klebsiella ornithinolytica, Escherichia coli, Enterobacter cloacae, Enterobacter aerogenes, Providencia rettgeri, Citrobacter freundii, Hafnia alvei, Salmonella spp., Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus. The main compounds of the oil were carvacrol (48.9%), E-caryophyllene (10.8%) and caryophyllene oxide (7.7%). The oil showed activity against all tested strains with minimal inhibitory concentration (MIC) values ranging between 1% and 4%. For most of the strains, the MIC value was equivalent to the minimal bactericidal concentration value, indicating a clear bactericidal effect of L. coronopifolia EO.

Phenotypic and Molecular Characterization of Multidrug Resistant Klebsiella pneumoniae Isolated from Different Clinical Sources in Al-Najaf Province-Iraq.

PubMed

Aljanaby, Ahmed Abduljabbar Jaloob; Alhasnawi, Haneen Mohammed Reda Jaber

2017-01-01

Burns infections and urinary tract infections are the most important prevalent diseases in Asian countries, such as Iraq. Klebsiella pneumoniae is one of the most important bacteria cause this type of infections especially in hospitals. Therefore, the aim of this study was to investigate the prevalence of multi-drug resistance K. pneumoniae and extended-spectrum beta-lactamases producing K. pneumoniae isolates from inpatients with urinary tract infection and burns infections in Al-Kufa hospital in Al-Najaf province, Iraq. A total of 285 clinical samples were collected from in-patients infected with urinary tract infection (141 urine samples) and burns infections (144 burns swabs). Fourteen different antibiotics were used by disc diffusion method and 13 antimicrobials resistance genes were used by PCR technique. A total of 43 K. pneumoniae strains were isolated. The highest resistance rate was observed for amoxicillin 25 μg and amoxicillin+clavulanic acid 20+10 μg (97.67%) while the lowest resistance rate was observed for imipenem 10 μg (9.30%). The most common resistance associated-genes were blaSHV (86.04%) and at lower prevalence were IMP (9.30%). Klebsiella pneumoniae strains isolated from burns infections were more virulent than those isolated from urinary tract infections.

Endosulfan induced alteration in bacterial protein profile and RNA yield of Klebsiella sp. M3, Achromobacter sp. M6, and Rhodococcus sp. M2.

PubMed

Singh, Madhu; Singh, Dileep Kumar

2014-01-30

Three bacterial strains identified as Klebsiella sp. M3, Achromobacter sp. M6 and Rhodococcus sp. M2 were isolated by soil enrichment with endosulfan followed by shake flask enrichment technique. They were efficiently degrading endosulfan in the NSM (non sulfur medium) broth. Degradation of endosulfan was faster with the cell free extract of bacterial cells grown in the sulfur deficient medium (NSM) supplemented with endosulfan than that of nutrient rich medium (Luria Bertani). In the cell free extract of NSM supplemented with endosulfan as sole sulfur source, a unique band was visualized on SDS-PAGE but not with magnesium sulfate as the sole sulfur source in NSM and LB with endosulfan. Expression of a unique polypeptide band was speculated to be induced by endosulfan under sulfur starved condition. These unique polypeptide bands were identified as OmpK35 protein, sulfate binding protein and outer membrane porin protein, respectively, in Klebsiella sp. M3, Achromobacter sp. M6 and Rhodococcus sp. M2. Endosulfan showed dose dependent negative effect on total RNA yield of bacterial strains in nutrient rich medium. Absence of plasmid DNA indicated the presence of endosulfan metabolizing gene on genomic DNA. Copyright © 2013 Elsevier B.V. All rights reserved.

Isolation of KPC 3-producing Enterobacter aerogenes in a patient colonized by MDR Klebsiella pneumoniae.

PubMed

Venditti, Carolina; Villa, Laura; Capone, Alessandro; Fortini, Daniela; D'Arezzo, Silvia; Nisii, Carla; Bordi, Eugenio; Puro, Vincenzo; Antonini, Mario; Carattoli, Alessandra; Cataldo, Maria Adriana; Petrosillo, Nicola; Di Caro, Antonino

2016-10-01

We describe the interspecies transmission of the plasmid-mediated blaKPC-3 gene, which confers carbapenem resistance, between clinically relevant gram-negative bacteria in a single patient. A KPC-3 producing Enterobacter aerogenes was isolated from a hospitalized patient previously colonized and then infected by a Klebsiella pneumoniae ST101 carrying the blaKPC-3 gene. The strains showed identical plasmids. Since intense horizontal exchanges among bacteria can occur in the gut, clinicians should be aware that patients colonized by carbapenem-resistant K. pneumoniae could become carriers of other carbapenem-resistant Enterobacteriaceae.

Alterations in the GyrA subunit of DNA gyrase and the ParC subunit of topoisomerase IV in quinolone-resistant clinical isolates of Klebsiella pneumoniae.

PubMed

Deguchi, T; Fukuoka, A; Yasuda, M; Nakano, M; Ozeki, S; Kanematsu, E; Nishino, Y; Ishihara, S; Ban, Y; Kawada, Y

1997-03-01

We determined a partial sequence of the Klebsiella pneumoniae parC gene, including the region analogous to the quinolone resistance-determining region of the Escherichia coli gyrA gene, and examined 26 clinical strains of K. pneumoniae for an association of alterations in GyrA and ParC with susceptibilities to quinolones. The study suggests that in K. pneumoniae DNA gyrase is a primary target of quinolones and that ParC alterations play a complementary role in the development of higher-level fluoroquinolone resistance.

Evaluation of the Biolog automated microbial identification system

NASA Technical Reports Server (NTRS)

Klingler, J. M.; Stowe, R. P.; Obenhuber, D. C.; Groves, T. O.; Mishra, S. K.; Pierson, D. L.

1992-01-01

Biolog's identification system was used to identify 39 American Type Culture Collection reference taxa and 45 gram-negative isolates from water samples. Of the reference strains, 98% were identified to genus level and 76% to species level within 4 to 24 h. Identification of some authentic strains of Enterobacter, Klebsiella, and Serratia was unreliable. A total of 93% of the water isolates were identified.

Interaction of non-human primate complement and antibodies with hypermucoviscous Klebsiella pneumoniae.

PubMed

Soto, Esteban; Marchi, Sylvia; Beierschmitt, Amy; Kearney, Michael; Francis, Stewart; VanNess, Kimberly; Vandenplas, Michel; Thrall, MaryAnna; Palmour, Roberta

2016-03-08

Emergent hypermucoviscosity (HMV) phenotypes of Klebsiella pneumoniae have been associated with increased invasiveness and pathogenicity in primates. In this study, we investigated the interaction of African green monkeys (AGM) (Chlorocebus aethiops sabaeus) complement and antibody with HMV and non-HMV isolates as in vitro models of primate infection. Significantly greater survival of HMV isolates was evident after incubation in normal serum or whole blood (p < 0.05) of AGM donors when compared to non-HMV strains. Greater survival of HMV strains (p < 0.05) was found after incubation in whole blood and serum from seropositive donors when compared to seronegative donor samples. Additionally, significantly greater amounts of K. pneumoniae were phagocytozed by AGM leukocytes when complement was active (p < 0.05), but no difference in uptake was observed when serum from seropositive or seronegative animals was used in challenged cells utilizing flow cytometry. Results demonstrate that interaction of cellular and humoral immune elements play a role in the in vitro killing of K. pneumoniae, particularly HMV isolates. Neither AGM serum, nor washed whole blood effectively killed HMV isolates; however, assays using heparinized whole blood of seronegative donors significantly reduced viability of HMV and non-HMV strains. The lack of bacterial killing observed in seropositive donors treatments could be at least partially associated with low IgG2 present in these animals. A better understanding of the pathogenesis of klebsiellosis in primates and host immune response is necessary to identify surface molecules that can induce both opsonizing and bactericidal antibody facilitating killing of Klebsiella, and the development of vaccines in human and animals.

Extended-Spectrum β-lactamase (ESBL) producing Enterobacter aerogenes phenotypically misidentified as Klebsiella pneumoniae or K. terrigena

PubMed Central

Claeys, Geert; De Baere, Thierry; Wauters, Georges; Vandecandelaere, Patricia; Verschraegen, Gerda; Muylaert, An; Vaneechoutte, Mario

2004-01-01

Background Enterobacter aerogenes and Klebsiella pneumoniae are common isolates in clinical microbiology and important as producers of extended spectrum β-lactamases (ESBL). The discrimination between both species, which is routinely based on biochemical characteristics, is generally accepted to be straightforward. Here we report that genotypically unrelated strains of E. aerogenes can be misidentified as K. pneumoniae by routine laboratories using standard biochemical identification and using identification automates. Results Ten clinical isolates, identified as K. pneumoniae or K. terrigena with the routinely used biochemical tests and with API-20E, were identified as E. aerogenes by tDNA-PCR – an identification that was confirmed by 16S rRNA gene sequencing for five of these isolates. Misidentification also occurred when using the automated identification systems Vitek 2 and Phoenix, and was due to delayed positivity for ornithine decarboxylase and motility. Subculture and prolonged incubation resulted in positive results for ornithine decarboxylase and for motility. It could be shown by RAPD-analysis that the E. aerogenes strains belonged to different genotypes. Conclusions Clinical E. aerogenes isolates can be easily misidentified as Klebsiella due to delayed positivity for ornithine decarboxylase and motility. The phenomenon may be widespread, since it was shown to occur among genotypically unrelated strains from different hospitals and different isolation dates. A useful clue for correct identification is the presence of an inducible β-lactamase, which is highly unusual for K. pneumoniae. In several instances, the use of genotypic techniques like tDNA-PCR may circumvent problems of phenotypic identification. PMID:15619329

[Klebsiella pneumoniae from K1 and Hypervirulent Clone ST23: First Documented Case in Portugal].

PubMed

Pereira, Aida; Petrucci, Tiago; Simões, Maria João

2017-06-30

The hypervirulent K1 serotype Klebsiella pneumoniae is responsible for a new invasive syndrome, typically associated to hepatic abscesses with extra-hepatic complications. Initially described in Taiwan, it has significantly spread to several Asian countries and more recently to Europe and North America, thus constituting an emerging and global problem. The authors describe a case report of a 64-years-old portuguese caucasian woman without any previous diseases or epidemiological risk factors such as trips or contact with Asian products or population, diagnosed with a pyogenic liver abscess with pleural effusion caused by this hyper-virulent strain. A successful clinical cure was achieved after the etiological identification and treatment with antimicrobial therapy combined with catheter drainage. This is the first identification of hypervirulent Klebsiella pneumonia ST 23 clone in Portugal in the context of an invasive syndrome.

Structure of a quinolone-stabilized cleavage complex of topoisomerase IV from Klebsiella pneumoniae and comparison with a related Streptococcus pneumoniae complex

PubMed Central

Veselkov, Dennis A.; Laponogov, Ivan; Pan, Xiao-Su; Selvarajah, Jogitha; Skamrova, Galyna B.; Branstrom, Arthur; Narasimhan, Jana; Prasad, Josyula V. N. Vara; Fisher, L. Mark; Sanderson, Mark R.

2016-01-01

Klebsiella pneumoniae is a Gram-negative bacterium that is responsible for a range of common infections, including pulmonary pneumonia, bloodstream infections and meningitis. Certain strains of Klebsiella have become highly resistant to antibiotics. Despite the vast amount of research carried out on this class of bacteria, the molecular structure of its topoisomerase IV, a type II topoisomerase essential for catalysing chromosomal segregation, had remained unknown. In this paper, the structure of its DNA-cleavage complex is reported at 3.35 Å resolution. The complex is comprised of ParC breakage-reunion and ParE TOPRIM domains of K. pneumoniae topoisomerase IV with DNA stabilized by levofloxacin, a broad-spectrum fluoroquinolone antimicrobial agent. This complex is compared with a similar complex from Streptococcus pneumoniae, which has recently been solved. PMID:27050128

Emergence of NDM-1 among carbapenem-resistant Klebsiella pneumoniae in Iraqi hospitals.

PubMed

Hussein, Nadheema Hammood

2017-09-01

Carbapenems are the last drugs of choice apart from colistin against serious infections caused by Gram-negative bacteria. However, there are increasing number of reports indicating prevailing emergence of metallo-β-lactamase (MBL)-producing clinical isolates worldwide and among them New Delhi MBL (NDM) is the most prevalent one. This study reports NDM-1 for the first time among Klebsiella pneumoniae from hospitalized patients in Baghdad, Iraq. Fifty-five clinical isolates of K. pneumoniae resistant to carbapenem were investigated from burned wounds, sputum, and blood samples. The susceptibility to different antibiotics was tested by VITEK-2 system. All strains were multidrug-resistant and they showed nine different antimicrobial-resistant patterns (A-I) and the most effective antibiotic on these strains was levofloxacin (85.45%). The phenotypic detection of carbapenemases by MASTDISCS D70C revealed 29 (52.73%) strains were MBL-producing, out of 55 were carbapenem-resistant K. pneumoniae strains. The bla NDM-1 and other MBL genes were detected by conventional PCR and the result showed 37 (67.27%) strains positive for bla NDM-1 gene and only 5 (9.1%) strains harbored bla IMP gene, while all strains were negative for bla VIM , bla SIM , bla GIM , and bla SPM genes. Our results showed the coexistence of both bla NDM-1 and bla IMP genes in three strains of K. pneumoniae, while indicated widespread NDM-1 in Baghdad, Iraq. Hence, it is necessary to follow proper infection control practices and physicians should be aware of the patients with such risk factors.

Characterization of a novel chaperone/usher fimbrial operon present on KpGI-5, a methionine tRNA gene-associated genomic island in Klebsiella pneumoniae

PubMed Central

2012-01-01

Background Several strain-specific Klebsiella pneumoniae virulence determinants have been described, though these have almost exclusively been linked with hypervirulent liver abscess-associated strains. Through PCR interrogation of integration hotspots, chromosome walking, island-tagging and fosmid-based marker rescue we captured and sequenced KpGI-5, a novel genomic island integrated into the met56 tRNA gene of K. pneumoniae KR116, a bloodstream isolate from a patient with pneumonia and neutropenic sepsis. Results The 14.0 kb KpGI-5 island exhibited a genome-anomalous G + C content, possessed near-perfect 46 bp direct repeats, encoded a γ1-chaperone/usher fimbrial cluster (fim2) and harboured seven other predicted genes of unknown function. Transcriptional analysis demonstrated expression of three fim2 genes, and suggested that the fim2A-fim2K cluster comprised an operon. As fimbrial systems are frequently implicated in pathogenesis, we examined the role of fim2 by analysing KR2107, a streptomycin-resistant derivative of KR116, and three isogenic mutants (Δfim, Δfim2 and ΔfimΔfim2) using biofilm assays, human cell adhesion assays and pair-wise competition-based murine models of intestinal colonization, lung infection and ascending urinary tract infection. Although no statistically significant role for fim2 was demonstrable, liver and kidney CFU counts for lung and urinary tract infection models, respectively, hinted at an ordered gradation of virulence: KR2107 (most virulent), KR2107∆fim2, KR2107∆fim and KR2107∆fim∆fim2 (least virulent). Thus, despite lack of statistical evidence there was a suggestion that fim and fim2 contribute additively to virulence in these murine infection models. However, further studies would be necessary to substantiate this hypothesis. Conclusion Although fim2 was present in 13% of Klebsiella spp. strains investigated, no obvious in vitro or in vivo role for the locus was identified, although there were subtle hints of involvement in urovirulence and bacterial dissemination from the respiratory tract. Based on our findings and on parallels with other fimbrial systems, we propose that fim2 has the potential to contribute beneficially to pathogenesis and/or environmental persistence of Klebsiella strains, at least under specific yet-to-be identified conditions. PMID:22520965

Phenotypic detection of Klebsiella pneumoniae carbapenemase among burns patients: first report from Iran.

PubMed

Rastegar Lari, Abdolaziz; Azimi, Leila; Rahbar, Mohammad; Fallah, Fatemeh; Alaghehbandan, Reza

2013-02-01

Resistance to antimicrobial agents such as carbapenems among enterobacteriacea has been increasing, especially in Klebsiella pneumonia that produces variety of enzymes including Klebsiella pneumoniae carbapenemase (KPC). This study is the first report of its kind investigating the resistance to carbapenems among burns patients in Iran. During a 6-month period, 28 hospitalized burn patients who required to be placed on broad spectrum antibiotics were studied. Isolated species identified by routine biochemical test. Susceptibility testing for these species was performed by recommended the CLSI guidelines method. The tested antibiotics included cefotaxime, cefepime, aztreonam, imipenem, amoxicillin+clavulonic acid, gentamicin, amikacin, tobramycin, tetracycline, and trimethoprim-sulfamethoxazole, and chloramphenicol. For determination of KPC in phenotypical forms, Modified Hodge Test was utilized as per CLSI recommendation. Thirty-five Klebsiella spp. were isolated from 28 hospitalized patients. Nineteen out of 35 Klebsiella isolates were resistant to imipenem and that all of them had positive KPC. Nine of imipenem resistant isolates were also resistant to all tested antibiotics. Mortality rate among patients with positive KPC was 33%. High rate of multi-drug resistant (MDR) strains in isolates with positive KPC is a major challenge in Iran and that it could cause an increase in both mortality and morbidity among burn patients. Thus, appropriate infection control measures and guidelines are needed to prevent such infections among burn patients. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

Ethanol production from glycerol-containing biodiesel waste by Klebsiella variicola shows maximum productivity under alkaline conditions.

PubMed

Suzuki, Toshihiro; Nishikawa, Chiaki; Seta, Kohei; Shigeno, Toshiya; Nakajima-Kambe, Toshiaki

2014-05-25

Biodiesel fuel (BDF) waste contains large amounts of crude glycerol as a by-product, and has a high alkaline pH. With regard to microbial conversion of ethanol from BDF-derived glycerol, bacteria that can produce ethanol at alkaline pH have not been reported to date. Isolation of bacteria that shows maximum productivity under alkaline conditions is essential to effective production of ethanol from BDF-derived glycerol. In this study, we isolated the Klebsiella variicola TB-83 strain, which demonstrated maximum ethanol productivity at alkaline pH. Strain TB-83 showed effective usage of crude glycerol with maximum ethanol production at pH 8.0-9.0, and the culture pH was finally neutralized by formate, a by-product. In addition, the ethanol productivity of strain TB-83 under various culture conditions was investigated. Ethanol production was more efficient with the addition of yeast extract. Strain TB-83 produced 9.8 g/L ethanol (0.86 mol/mol glycerol) from cooking oil-derived BDF waste. Ethanol production from cooking oil-derived BDF waste was higher than that of new frying oil-derived BDF and pure-glycerol. This is the first report to demonstrate that the K. variicola strain TB-83 has the ability to produce ethanol from glycerol at alkaline pH. Copyright © 2014 Elsevier B.V. All rights reserved.

Characterization of an Outbreak of Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae in a Neonatal Intensive Care Unit in Italy.

PubMed

Corbella, Marta; Caltagirone, Mariasofia; Gaiarsa, Stefano; Mariani, Bianca; Sassera, Davide; Bitar, Ibrahim; Muzzi, Alba; Migliavacca, Roberta; Scudeller, Luigia; Stronati, Mauro; Cambieri, Patrizia

2018-01-25

Here we report an outbreak of extended spectrum β-lactamase-producing Klebsiella pneumoniae that occurred in a neonatal intensive care unit in Northern Italy and involved 97 patients. Progressively tightened sets of containment measures were implemented but the epidemic event was stopped only 9 months later. The final, effective, containment strategy consisted of the application of strict geographic cohorting of colonized infants and their nursing staff, the suspension of any new admission and a rigorous daily sterilization protocol for all surfaces and fomites in the ward. A posteriori characterization of the outbreak strain was performed using both traditional microbiology and molecular biology techniques, and whole genome sequencing, allowing to compare outbreak isolates with other strains collected in the previous two years. The results allowed to determine that the outbreak strain had been circulating inside the ward since the year before. Genomic characterization revealed that the strain carried a wide array of virulence and antibiotic resistance determinants, including gene bla TEM-206 , which had never been reported in a clinical isolate of K. pneumoniae before. The presence of such a high number of determinants for antibiotic resistance imposes significant therapeutic limitations on the treatment of infections, thus, further epidemiological investigations are needed to evaluate the prevalence of the newly described variant.

Carbapenemase-Producing Klebsiella pneumoniae in Romania: A Six-Month Survey

PubMed Central

Straut, Monica; Usein, Codruta Romanita; Cristea, Dana; Ciontea, Simona; Codita, Irina; Rafila, Alexandru; Nica, Maria; Buzea, Mariana; Baicus, Anda; Ghita, Mihaela Camelia; Nistor, Irina; Tuchiluş, Cristina; Indreas, Marina; Antohe, Felicia; Glasner, Corinna; Grundmann, Hajo; Jasir, Aftab; Damian, Maria

2015-01-01

This study presents the first characterization of carbapenem-non-susceptible Klebsiella pneumoniae isolates by means of a structured six-month survey performed in Romania as part of an Europe-wide investigation. Klebsiella pneumoniae clinical isolates from different anatomical sites were tested for antibiotic susceptibility by phenotypic methods and confirmed by PCR for the presence of four carbapenemase genes. Genome macrorestriction fingerprinting with XbaI was used to analyze the relatedness of carbapenemase-producing Klebsiella pneumoniae isolates collected from eight hospitals. Among 75 non-susceptible isolates, 65 were carbapenemase producers. The most frequently identified genotype was OXA-48 (n = 51 isolates), eight isolates were positive for bla NDM-1 gene, four had the bla KPC-2 gene, whereas two were positive for bla VIM-1. The analysis of PFGE profiles of OXA-48 and NDM-1 producing K. pneumoniae suggests inter-hospitals and regional transmission of epidemic clones. This study presents the first description of K. pneumoniae strains harbouring bla KPC-2 and bla VIM-1 genes in Romania. The results of this study highlight the urgent need for the strengthening of hospital infection control measures in Romania in order to curb the further spread of the antibiotic resistance. PMID:26599338

Carbapenemase-Producing Klebsiella pneumoniae in Romania: A Six-Month Survey.

PubMed

Lixandru, Brandusa Elena; Cotar, Ani Ioana; Straut, Monica; Usein, Codruta Romanita; Cristea, Dana; Ciontea, Simona; Tatu-Chitoiu, Dorina; Codita, Irina; Rafila, Alexandru; Nica, Maria; Buzea, Mariana; Baicus, Anda; Ghita, Mihaela Camelia; Nistor, Irina; Tuchiluş, Cristina; Indreas, Marina; Antohe, Felicia; Glasner, Corinna; Grundmann, Hajo; Jasir, Aftab; Damian, Maria

2015-01-01

This study presents the first characterization of carbapenem-non-susceptible Klebsiella pneumoniae isolates by means of a structured six-month survey performed in Romania as part of an Europe-wide investigation. Klebsiella pneumoniae clinical isolates from different anatomical sites were tested for antibiotic susceptibility by phenotypic methods and confirmed by PCR for the presence of four carbapenemase genes. Genome macrorestriction fingerprinting with XbaI was used to analyze the relatedness of carbapenemase-producing Klebsiella pneumoniae isolates collected from eight hospitals. Among 75 non-susceptible isolates, 65 were carbapenemase producers. The most frequently identified genotype was OXA-48 (n = 51 isolates), eight isolates were positive for blaNDM-1 gene, four had the blaKPC-2 gene, whereas two were positive for blaVIM-1. The analysis of PFGE profiles of OXA-48 and NDM-1 producing K. pneumoniae suggests inter-hospitals and regional transmission of epidemic clones. This study presents the first description of K. pneumoniae strains harbouring blaKPC-2 and blaVIM-1 genes in Romania. The results of this study highlight the urgent need for the strengthening of hospital infection control measures in Romania in order to curb the further spread of the antibiotic resistance.

Surface antigens contribute differently to the pathophysiological features in serotype K1 and K2 Klebsiella pneumoniae strains isolated from liver abscesses.

PubMed

Yeh, Kuo-Ming; Chiu, Sheng-Kung; Lin, Chii-Lan; Huang, Li-Yueh; Tsai, Yu-Kuo; Chang, Jen-Chang; Lin, Jung-Chung; Chang, Feng-Yee; Siu, Leung-Kei

2016-01-01

The virulence role of surface antigens in a single serotype of Klebsiella pneumoniae strain have been studied, but little is known about whether their contribution will vary with serotype. To investigate the role of K and O antigen in hyper-virulent strains, we constructed O and K antigen deficient mutants from serotype K1 STL43 and K2 TSGH strains from patients with liver abscess, and characterized their virulence in according to the abscess formation and resistance to neutrophil phagocytosis, serum, and bacterial clearance in liver. Both of K1 and K2-antigen mutants lost their wildtype resistance to neutrophil phagocytosis and hepatic clearance, and failed to cause abscess formation. K2-antigen mutant became serum susceptible while K1-antigen mutant maintained its resistance to serum killing. The amount of glucuronic acid, indicating the amount of capsular polysaccharide (CPS, K antigen), was inversed proportional to the rate of phagocytosis. O-antigen mutant of serotype K1 strains had significantly more amount of CPS, and more resistant to neutrophil phagocytosis than its wildtype counterpart. O-antigen mutants of serotype K1 and K2 strains lost their wildtype serum resistance, and kept resistant to neutrophil phagocytosis. While both mutants lacked the same O1 antigen, O-antigen mutant of serotype K1 became susceptible to liver clearance and cause mild abscess formation, but its serotype K2 counterpart maintained these wildtype virulence. We conclude that the contribution of surface antigens to virulence of K. pneumoniae strains varies with serotypes.

Clonality and Resistome analysis of KPC-producing Klebsiella pneumoniae strain isolated in Korea using whole genome sequencing.

PubMed

Lee, Yangsoon; Kim, Bong-Soo; Chun, Jongsik; Yong, Ji Hyun; Lee, Yeong Seon; Yoo, Jung Sik; Yong, Dongeun; Hong, Seong Geun; D'Souza, Roshan; Thomson, Kenneth S; Lee, Kyungwon; Chong, Yunsop

2014-01-01

We analyzed the whole genome sequence and resistome of the outbreak Klebsiella pneumoniae strain MP14 and compared it with those of K. pneumoniae carbapenemase- (KPC-) producing isolates that showed high similarity in the NCBI genome database. A KPC-2-producing multidrug-resistant (MDR) K. pneumoniae clinical isolate was obtained from a patient admitted to a Korean hospital in 2011. The strain MP14 was resistant to all tested β-lactams including monobactam, amikacin, levofloxacin, and cotrimoxazole, but susceptible to tigecycline and colistin. Resistome analysis showed the presence of β-lactamase genes including bla KPC-2, bla SHV-11, bla TEM-169, and bla OXA-9. MP14 also possessed aac(6'-)Ib, aadA2, and aph(3'-)Ia as aminoglycoside resistance-encoding genes, mph(A) for macrolides, oqxA and oqxB for quinolone, catA1 for phenicol, sul1 for sulfonamide, and dfrA12 for trimethoprim. Both SNP tree and cgMLST analysis showed the close relatedness with the KPC producers (KPNIH strains) isolated from an outbreak in the USA and colistin-resistant strains isolated in Italy. The plasmid-scaffold genes in plasmids pKpQil, pKpQil-IT, pKPN3, or pKPN-IT were identified in MP14, KPNIH, and Italian strains. The KPC-2-producing MDR K. pneumoniae ST258 stain isolated in Korea was highly clonally related with MDR K. pneumoniae strains from the USA and Italy. Global spread of KPC-producing K. pneumoniae is a worrying phenomenon.

Outbreak of OXA-48-Producing Klebsiella pneumoniae Involving a Sequence Type 101 Clone in Batna University Hospital, Algeria

PubMed Central

Loucif, Lotfi; Kassah-Laouar, Ahmed; Saidi, Mahdia; Messala, Amina; Chelaghma, Widad

2016-01-01

Seven nonredundant ertapenem-resistant Klebsiella pneumoniae isolates were collected between May 2014 and 19 January 2015 in the nephrology and hematology units of Batna University Hospital in Algeria. All strains coproduced the blaOXA-48, blaCTX-M-15, blaSHV-1, and blaTEM-1D genes. Six of these isolates belonged to the pandemic clone sequence type 101 (ST101). The blaOXA-48 gene was located on a conjugative IncL/M-type plasmid. This is the first known outbreak of OXA-48-producing K. pneumoniae isolates involving an ST101 clone in Batna University Hospital. PMID:27645236

Outbreak of Colistin-Resistant, Carbapenemase-Producing Klebsiella pneumoniae: Are We at the End of the Road?

PubMed Central

van Duin, David

2015-01-01

Carbapenem-resistant Klebsiella pneumoniae strains that produce K. pneumoniae carbapenemase (KPC) have spread globally in the last decade. Colistin is a key agent in treating infections caused by this pathogen. In this issue of the Journal of Clinical Microbiology, Giani et al. (T. Giani, F. Arena, G. Vaggelli, V. Conte, A Chiarell, L. H. De Angelis, R. Fornaini, M. Grazzini, F. Niccolini, P. Pecile, and G. M. Rossolini, J Clin Microbiol 53:3341–3344, 2015, http://dx.doi.org/10.1128/JCM.01017-15) describe a sustained outbreak of colistin-resistant KPC-producing K. pneumoniae. PMID:26202122

Inorganic phosphate accumulation and cadmium detoxification in Klebsiella aerogenes NCTC 418 growing in continuous culture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aiking, H.; Stijnman, A.; van Garderen, C.

1984-02-01

Klebsiella aerogenes NCTC-418, growing in the presence of cadmium under glucose-, sulfate-, or phosphate-limited conditions in continuous culture, exhibits two different cadmium detoxifying mechanisms. In addition to sulfide formation, increased accumulation of P/sub i/ is demonstrated as a novel mechanism. Intracellular cadmium is always quantitatively counterbalanced by a concerted increase in both inorganic sulfide and P/sub i/ contents of the cells. This led to the conclusion that production of sulfide and accumulation of P/sub i/ are detoxification mechanisms present in K. aerogenes but that their relative importance is crucially dependent on the strain and the growth conditions employed.

Improved antimicrobial activity of DU-6859a, a new fluoroquinolone, against quinolone-resistant Klebsiella pneumoniae and Enterobacter cloacae isolates with alterations in GyrA and ParC proteins.

PubMed Central

Deguchi, T; Yasuda, M; KawamuraT; Nakano, M; Ozeki, S; Kanematsu, E; Nishino, Y; Kawada, Y

1997-01-01

MICs of DU-6859a, a novel fluoroquinolone, for 18 Klebsiella pneumoniae isolates and 21 Enterobacter cloacae isolates with altered GyrA or altered GyrA and ParC ranged from < or =0.025 to 6.25 microg/ml and from 0.1 to 3.13 microg/ml, respectively. Based on the MICs at which 90% of the isolates were inhibited for these strains of K. pneumoniae and E. cloacae, DU-6859a exhibited 16- to 256-fold-greater activity than currently available fluoroquinolones. PMID:9371364

Improved antimicrobial activity of DU-6859a, a new fluoroquinolone, against quinolone-resistant Klebsiella pneumoniae and Enterobacter cloacae isolates with alterations in GyrA and ParC proteins.

PubMed

Deguchi, T; Yasuda, M; KawamuraT; Nakano, M; Ozeki, S; Kanematsu, E; Nishino, Y; Kawada, Y

1997-11-01

MICs of DU-6859a, a novel fluoroquinolone, for 18 Klebsiella pneumoniae isolates and 21 Enterobacter cloacae isolates with altered GyrA or altered GyrA and ParC ranged from < or =0.025 to 6.25 microg/ml and from 0.1 to 3.13 microg/ml, respectively. Based on the MICs at which 90% of the isolates were inhibited for these strains of K. pneumoniae and E. cloacae, DU-6859a exhibited 16- to 256-fold-greater activity than currently available fluoroquinolones.

21 CFR 520.1618 - Orbifloxacin suspension.

Code of Federal Regulations, 2011 CFR

2011-04-01

... spp., Klebsiella pneumoniae, E. coli, Enterobacter spp., Citrobacter spp., E. faecalis, β-hemolytic...) in cats caused by susceptible strains of S. aureus, E. coli, and P. multocida. [75 FR 26646, May 12... pseudintermedius, Proteus mirabilis, Escherichia coli, and Enterococcus faecalis and skin and soft tissue...

Synergistic action between sisomicin and mezlocillin against gram-negative bacteria and Staphylococcus aureus.

PubMed

Soares, L A; Trabulsi, L R

1979-01-01

The combined effect of sisomicin and 6-[(R)-2-[3-methylsulfonyl-2-oxo-imidazolidine-1-carboxamido]-2-phenyl-acetamido-a1-penicillanic acid sodium salt (mezlocillin, Baypen) was studied against 50 bacterial strains, including Pseudomonas aeruginosa, Proteus spp. Klebsiella-Enterobacter, E. coli and Staphylococcus aureus. No antagonism or indifference was detected with the strains studied. Both antibiotics were synergistic against 62% of the strains, and partially synergistic against 38%. Out of the bacteria studied, Staphylococcus aureus was the most susceptible to the combined action of sisomicin and mezlocillin.

Simultaneous production of 2,3-butanediol, ethanol and hydrogen with a Klebsiella sp. strain isolated from sewage sludge.

PubMed

Wu, Ken-Jer; Saratale, Ganesh D; Lo, Yung-Chung; Chen, Wen-Ming; Tseng, Ze-Jing; Chang, Ming-Ching; Tsai, Ben-Ching; Su, Ay; Chang, Jo-Shu

2008-11-01

A Klebsiella sp. HE1 strain isolated from hydrogen-producing sewage sludge was examined for its ability to produce H2 and other valuable soluble metabolites (e.g., ethanol and 2,3-butanediol) from sucrose-based medium. The effect of pH and carbon substrate concentration on the production of soluble and gaseous products was investigated. The major soluble metabolite produced from Klebsiella sp. HE1 was 2,3-butanediol, accounting for over 42-58% of soluble microbial products (SMP) and its production efficiency enhanced after increasing the initial culture pH to 7.3 (without pH control). The HE1 strain also produced ethanol (contributing to 29-42% of total SMP) and a small amount of lactic acid and acetic acid. The gaseous products consisted of H2 (25-36%) and CO2 (64-75%). The optimal cumulative hydrogen production (2.7 l) and hydrogen yield (0.92mol H2 mol sucrose(-1)) were obtained at an initial sucrose concentration of 30g CODl(-1) (i.e., 26.7gl(-1)), which also led to the highest production rate for H2 (3.26mmol h(-1)l(-1)), ethanol (6.75mmol h(-1)l(-1)) and 2,3-butanediol (7.14mmol h(-1)l(-1)). The highest yield for H2, ethanol and 2,3-butanediol was 0.92, 0.81 and 0.59molmol-sucrose(-1), respectively. As for the overall energy production performance, the highest energy generation rate was 27.7kJ h(-1)l(-1) and the best energy yield was 2.45kJmolsucrose(-1), which was obtained at a sucrose concentration of 30 and 20g CODl(-1), respectively.

Risk factors for KPC-producing Klebsiella pneumoniae: watch out for surgery.

PubMed

da Silva, Kesia Esther; Maciel, Wirlaine Glauce; Sacchi, Flávia Patussi Correia; Carvalhaes, Cecilia Godoy; Rodrigues-Costa, Fernanda; da Silva, Ana Carolina Ramos; Croda, Mariana Garcia; Negrão, Fábio Juliano; Croda, Julio; Gales, Ana Cristina; Simionatto, Simone

2016-06-01

This study describes the molecular characteristics and risk factors associated with carbapenem-resistant Klebsiella pneumoniae strains. Risk factors associated with KPC-producing K. pneumoniae strains were investigated in this case-control study from May 2011 to May 2013. Bacterial identification was performed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Antimicrobial susceptibility was determined by broth microdilution. Carbapenemase production was assessed by both modified Hodge test (MHT) and ertapenem hydrolysis using MALDI-TOF MS. The presence of β-lactamase-encoding genes was evaluated by PCR and DNA sequencing. Alterations in genes encoding K. pneumoniae outer membrane proteins were analysed by PCR and DNA sequencing as well as SDS-PAGE. Genetic relatedness among strains was determined by pulsed-field gel electrophoresis. This study included 94 patients. Longer hospitalisation, mechanical ventilation, catheters, and previous surgery were associated with KPC-producing K. pneumoniae. Sixty-eight strains showed resistance to carbapenems. Carbapenemase production was detected by MHT in 67 K. pneumoniae strains and by MALDI-TOF MS in 57. The presence of the blaKPC-2 gene was identified in 57 strains. The blaKPC-2 gene was not found in 11 carbapenem-resistant K. pneumoniae; instead, the blaCTX-M-1-like, blaCTX-M-2-like, blaCTX-M-8 like, blaCTX-M-14-like and blaSHV- like genes associated with OmpK35 and OmpK36 alterations were observed. Thirty-three KPC-producing K. pneumoniae strains were clonally related, and patients infected with these strains had a higher mortality rate (78.78 %). Our results show that KPC-producing K. pneumoniae was associated with several healthcare-related risk factors, including recent surgery.

[Clonal relationship and detection of blaKPC gene in strains of Klebsiella pneumoniae resistant to carbapenems, at a hospital in Venezuela].

PubMed

Martínez, Dianny; Araque, Yasmina; Roduifo, Hectorina; Caña, Luisa; García, José; Gonzáiez, Diorelis; Rodríguez, Lucy; De Donato, Marcos

2016-10-01

In order to study the clonal relationship and blaKPC gene detection in clinical isolates of Klebsiella pneumoniae resistant to carbapenems, we analyzed 22 clinical isolates of K. pneumoniae with resistance to imipenem and/ or meropenem, isolated in the laboratory of bacteriology at the University Hospital "Antonio Patricio de Alcalá" (HUAPA) from the Cumana city, Sucre state, Venezuela, for a period of five consecutive years. Susceptibility to different antimicrobials was determined, and the presence of carbapenemases was detected by modified Hodge method, phenyl boronic acid synergy and combination discs. blaKPC gene detection was conducted by polymerase chain reaction and the clonal relationship was determined by pulsed field electrophoresis. High rates of antimicrobial resistance were found, five strains were negative, at least one phenotypic method, and all carried the blaKPC gene. Clonal spread was observed only in the intensive care unit (ICU), while in other services, polyclonality was found. We concluded that blaKPC gene is present in K. pneumoniae strains resistant to carbapenems isolated in the HUAPA and clonal spread it was only in the ICU.

Influence of Bacterial Biofilm Polysaccharide Structure on Interactions with Antimicrobial Peptides: A Study on Klebsiella pneumoniae.

PubMed

Bellich, Barbara; Lagatolla, Cristina; Tossi, Alessandro; Benincasa, Monica; Cescutti, Paola; Rizzo, Roberto

2018-06-06

Biofilms are complex systems produced by bacteria and constituted by macromolecular matrix embedding cells. They provide advantages to bacteria including protection against antimicrobials. The protection given by biofilms produced by Klebsiella pneumoniae strains towards antimicrobial peptides of the innate immune system was investigated. In particular, the role of matrix bacterial exopolysaccharides was explored. Three clinical strains producing exopolysaccharides with different chemistry were selected and the interaction of purified biofilm polysaccharides with two bovine cathelicidins was studied by circular dichroism spectroscopy and microbiological assays to establish their influence on the peptide’s antimicrobial activity. The spectroscopic data indicated a different extent of interaction with the two peptides, in a manner dependent on their sugar composition, and in particular the presence of rhamnose residues correlated with a lower interaction. The extent of interaction was then related to the protection towards antimicrobial peptides, conferred by the addition of the different exopolysaccharides, in minimum inhibitory concentration (MIC) assays against a reference Escherichia coli strain. Microbiological results were in very good agreement with spectroscopic data, confirming the active role of matrix polysaccharides in determining a biofilm’s protective capacity and indicating lower protection levels afforded by rhamnose containing exopolysaccharides.

Degradation of euptox A by tannase-producing rumen bacteria from migratory goats.

PubMed

Sharma, D; Mal, G; Kannan, A; Bhar, R; Sharma, R; Singh, B

2017-11-01

The gut microbiota capable of degrading plant biomass and antinutritional phytometabolites are of immense importance. This study reports isolation and characterization of tannase-producing rumen bacteria that could also degrade euptox A (9-oxo-10,11-dehydroageraphorone) present in Eupatorium adenophorum (Spreng). Migratory Gaddi goats were selected as source of inoculums for isolating rumen bacteria with ability to produce tannase which catalyses degradation of hydrolysable tannins (HTs). Three rumen bacterial isolates producing tannase were studied, and identified as Klebsiella variicola strain PLP G-17 LC, K. variicola strain PLP S-18 and Klebsiella pneumoniae strain PLP G-17 SC. The isolates exhibited optimal tannase activity at 40°C, and pH 6·0. The bacteria could also degrade euptox A, a potent hepatotoxin in E. adenophorum Spreng, a widely distributed noxious weed. The rumen bacteria could degrade antinutritional HTs and euptox A. Culture-independent metagenomic interventions are envisioned to completely decipher the rumen microbial ecology and exploit its genetic and metabolic potential. The bacteria producing tannase which catalyses degradation of HTs, and concurrently degrading euptox A, may have potential as microbial feed additives to increase utilization of plant biomass containing antinutritional phytometabolites. © 2017 The Society for Applied Microbiology.

Nosocomial bacteremia and urinary tract infections caused by extended-spectrum beta -lactamase-producing Klebsiella pneumoniae with plasmids carrying both SHV-5 and TLA-1 genes.

PubMed

Alcantar-Curiel, Dolores; Tinoco, Juan Carlos; Gayosso, Catalina; Carlos, Angeles; Daza, Carlos; Perez-Prado, Maria C; Salcido, Lorena; Santos, Jose I; Alpuche-Aranda, Celia M

2004-04-15

We describe the prevalence and molecular characteristics of extended-spectrum beta -lactamase (ESBL)-producing Klebsiella pneumoniae causing nosocomial bacteremia and urinary tract infections in a Mexican general hospital. We analyzed 82 episodes of bacteremia (approximately 60% of episodes) and urinary tract infection (approximately 40% of episodes) due to K. pneumoniae during a 23-month surveillance period. The neonatal intensive care unit accounted for 49% of all episodes. All strains were imipenem susceptible; 62.2% of the strains were resistant to ceftazidime, cefotaxime, and aztreonam; 69.5% were resistant to amikacin; 58.5% were resistant to gentamicin; and 7.3% were resistant to ciprofloxacin. All strains were associated with 28 pulsed-field gel electrophoresis patterns, and dissemination of 2 ceftazidime-resistant clones produced 44% of the cases. The ESBL phenotype in these clones was transferred by identical or highly related megaplasmids. The ESBL activity corresponded to SHV-5 and TLA-1. Cross-transmission of 2 ceftazidime-resistant clones and the horizontal spread of identical or highly related megaplasmids explain the high prevalence of ESBL phenotype in these infections.

The study of adhesive forces between the type-3 fimbriae of Klebsiella pneumoniae and collagen-coated surfaces by using optical tweezers

NASA Astrophysics Data System (ADS)

Chan, Chiahan; Fan, Chia-chieh; Huang, Ying-Jung; Peng, Hwei-Ling; Long, Hsu

2004-10-01

Adherence to host cells by a bacterial pathogen is a critical step for establishment of infection. It will contribute greatly to the understanding of bacterial pathogenesis by studying the biological force between a single pair of pathogen and host cell. In our experiment, we use a calibrated optical tweezers system to detach a single Klebsiella pneumoniae, the pathogen, from collagen, the host. By gradually increasing the laser power of the optical tweezers until the Klebsiella pneumoniae is detached from the collagen, we obtain the magnitude of the adhesive force between them. This happens when the adhesive force is barely equal to the trapping force provided by the optical tweezers at that specific laser power. This study is important because Klebsiella pneumoniae is an opportunistic pathogen which causes suppurative lesions, urinary and respiratory tract infections. It has been proved that type 3 fimbrial adhesin (mrkD) is strongly associated with the adherence of Klebsiella pneumoniae. Besides, four polymorphic mrkD alleles: namely, mrkDv1, v2, v3, and v4, are typed by using RFLP. In order to investigate the relationship between the structure and the function for each of these variants, DNA fragments encoding the major fimbrial proteins mrkA, mrkB, mrkC are expressed together with any of the four mrkD adhesins in E. coli JM109. Our study shows that the E. coli strain carrying the mrkDv3 fimbriae has the strongest binding activity. This suggests that mrkDv3 is a key factor that enhances the adherence of Klebsiella Pneumoniae to human body.

Development of a Colloidal Gold-Based Immunochromatographic Strip for Rapid Detection of Klebsiella pneumoniae Serotypes K1 and K2

PubMed Central

Siu, L. Kristopher; Tsai, Yu-Kuo; Lin, Jung-Chung; Chen, Te-Li; Fung, Chang-Phone

2016-01-01

In this study, a novel colloidal gold-based immunochromatographic strip (ICS) containing anti-Klebsiella pneumoniae capsular polysaccharide polyclonal antibodies was developed to specifically detect K. pneumoniae serotypes K1 and K2. Capsular polysaccharide K1 and K2 antigens were first used to produce polyclonal anti-K1 and anti-K2 antibodies. Reference strains with different serotypes, nontypeable K. pneumoniae strains, and other bacterial species were then used to assess the sensitivity and specificity of these test strips. The detection limit was found to be 105 CFU, and the ICSs were stable for 6 months when stored at room temperature. No false-positive or false-negative results were observed, and equivalent results were obtained compared to those of more conventional test methods, such as PCR or serum agglutination. In conclusion, the ICS developed here requires no technical expertise and allows for the specific, rapid, and simultaneous detection of K. pneumoniae serotypes K1 and K2. PMID:27707941

Survey of pathogens in threatened wild red-tailed Amazon parrot (Amazona brasiliensis) nestlings in Rasa Island, Brazil.

PubMed

Vaz, Frederico Fontanelli; Serafini, Patrícia Pereira; Locatelli-Dittrich, Rosangela; Meurer, Rafael; Durigon, Edison Luiz; de Araújo, Jansen; Thomazelli, Luciano Matsumiya; Ometto, Tatiana; Sipinski, Elenise Angelotti Bastos; Sezerban, Rafael Meirelles; Abbud, Maria Cecília; Raso, Tânia Freitas

The red-tailed Amazon parrot (Amazona brasiliensis) is a threatened species of psittacine bird that inhabit coastal regions of Brazil. In view of the threat of this species, the aim of this study was to perform a health evaluation in wild nestlings in Rasa Island, determining the prevalence of enterobacteria and infectious agents according to type of nest. Blood samples were collected from 64 birds and evaluated for antibodies of Chlamydia psittaci by commercial dot-blot ELISA. Cloacal and oropharyngeal swabs samples were collected from 23 birds from artificial wooden nests, 15 birds from PVC nests and 2 birds from natural nests for microbiological analysis. Swab samples were collected from 58 parrots for C. psittaci detection by PCR and from 50 nestlings for Avian Influenza, Newcastle Disease and West Nile viruses' detection analysis by real-time RT-PCR. Ten bacterial genera and 17 species were identified, and the most prevalent were Escherichia coli and Klebsiella oxytoca. There was no influence of the type of nest in the nestlings' microbiota. All samples tested by ELISA and PCR were negative. There is currently insufficient information available about the health of A. brasiliensis and data of this study provide a reference point for future evaluations and aid in conservation plans. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Empirical prediction and validation of antibacterial inhibitory effects of various plant essential oils on common pathogenic bacteria.

PubMed

Akdemir Evrendilek, Gulsun

2015-06-02

In this study, fractional compound composition, antioxidant capacity, and phenolic substance content of 14 plant essential oils-anise (Pimpinella anisum), bay leaves (Laurus nobilis), cinnamon bark (Cinnamomum verum), clove (Eugenia caryophyllata), fennel (Foeniculum vulgare), hop (Humulus lupulus), Istanbul oregano (Origanum vulgare subsp. hirtum), Izmir oregano (Origanum onites), mint (Mentha piperita), myrtus (Myrtus communis), orange peel (Citrus sinensis), sage (Salvia officinalis), thyme (Thymbra spicata), and Turkish oregano (Origanum minutiflorum)--were related to inhibition of 10 bacteria through multiple linear or non-linear (M(N)LR) models-four Gram-positive bacteria of Listeria innocua, coagulase-negative staphylococci, Staphylococcus aureus, and Bacillus subtilis, and six Gram-negative bacteria of Yersinia enterocolitica, Salmonella Enteritidis, Salmonella Typhimurium, Proteus mirabilis, Escherichia coli O157:H7, and Klebsiella oxytoca. A total of 65 compounds with different antioxidant capacity, phenolic substance content and antibacterial properties were detected with 14 plant essential oils. The best-fit M(N)LR models indicated that relative to anise essential oil, the essential oils of oreganos, cinnamon, and thyme had consistently high inhibitory effects, while orange peel essential oil had consistently a low inhibitory effect. Regression analysis indicated that beta-bisabolene (Turkish and Istanbul oreganos), and terpinolene (thyme) were found to be the most inhibitory compounds regardless of the bacteria type tested. Copyright © 2015 Elsevier B.V. All rights reserved.

Foodborne Pathogens Recovered from Ready-to-Eat Foods from Roadside Cafeterias and Retail Outlets in Alice, Eastern Cape Province, South Africa: Public Health Implications

PubMed Central

Nyenje, Mirriam E.; Odjadjare, Collins E.; Tanih, Nicoline F.; Green, Ezekiel; Ndip, Roland N.

2012-01-01

This study assessed the microbiological quality of various ready-to-eat foods sold in Alice, South Africa. Microbiological analysis was conducted on 252 samples which included vegetables, potatoes, rice, pies, beef and chicken stew. The isolates were identified using biochemical tests and the API 20E, API 20NE and API Listeria kits; results were analyzed using the one-way-ANOVA test. Bacterial growth was present in all the food types tested; high levels of total aerobic count were observed in vegetables, 6.8 ± 0.07 followed by rice, 6.7 ± 1.7 while pies had the lowest count (2.58 ± 0.24). Organisms isolated included: Listeria spp. (22%), Enterobacter spp. (18%), Aeromonas hydrophila (12%), Klebsiella oxytoca (8%), Proteus mirabilis (6.3%), Staphylococcus aureus (3.2%) and Pseudomonas luteola (2.4%). Interestingly, Salmonella spp. and Escherichia coli were not isolated in any of the samples. There was a statistically significant difference (p < 0.05) in the prevalence of foodborne pathogens from hygienic and unhygienic cafeterias. The results indicated that most of the ready-to-eat food samples examined in this study did not meet bacteriological quality standards, therefore posing potential risks to consumers. This should draw the attention of the relevant authorities to ensure that hygienic standards are improved to curtain foodborne infections. PMID:23066386

Non-traumatic subdural hematoma secondary to septic brain embolism: A rare cause of unexpected death in a drug addict suffering from undiagnosed bacterial endocarditis.

PubMed

Geisenberger, D; Huppertz, L M; Büchsel, M; Kramer, L; Pollak, S; Große Perdekamp, M

2015-12-01

Acute subdural hematomas are mostly due to blunt traumatization of the head. In rare instances, subdural bleeding occurs without evidence of a previous trauma following spontaneous hemorrhage, e.g. from a ruptured aneurysm or an intracerebral hematoma perforating the brain surface and the arachnoid. The paper presents the morphological, microbiological and toxicological findings in a 38-year-old drug addict who was found by his partner in a dazed state. When brought to a hospital, he underwent trepanation to empty a right-sided subdural hematoma, but he died already 4h after admission. Autopsy revealed previously undiagnosed infective endocarditis of the aortic valve as well as multiple infarctions of brain, spleen and kidneys obviously caused by septic emboli. The subdural hematoma originated from a subcortical brain hemorrhage which had perforated into the subdural space. Microbiological investigation of the polypous vegetations adhering to the aortic valve revealed colonization by Streptococcus mitis and Klebsiella oxytoca. According to the toxicological analysis, no psychotropic substances had contributed to the lethal outcome. The case reported underlines that all deaths of drug addicts should be subjected to complete forensic autopsy, as apart from intoxications also natural and traumatic causes of death have to be taken into consideration. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Honeybee (Apis mellifera)-associated bacterial community affected by American foulbrood: detection of Paenibacillus larvae via microbiome analysis.

PubMed

Erban, Tomas; Ledvinka, Ondrej; Kamler, Martin; Nesvorna, Marta; Hortova, Bronislava; Tyl, Jan; Titera, Dalibor; Markovic, Martin; Hubert, Jan

2017-07-11

Honeybee (Apis mellifera L.) workers act as passive vectors of Paenibacillus larvae spores, which cause the quarantine disease American foulbrood (AFB). We assessed the relative proportions of P. larvae within the honeybee microbiome using metabarcoding analysis of the 16 S rRNA gene. The microbiome was analyzed in workers outside of the AFB zone (control - AFB0), in workers from asymptomatic colonies in an AFB apiary (AFB1), and in workers from colonies exhibiting clinical AFB symptoms (AFB2). The microbiome was processed for the entire community and for a cut-off microbiome comprising pathogenic/environmental bacteria following the removal of core bacterial sequences; varroosis levels were considered in the statistical analysis. No correlation was observed between AFB status and varroosis level, but AFB influenced the worker bee bacterial community, primarily the pathogenic/environmental bacteria. There was no significant difference in the relative abundance of P. larvae between the AFB1 and AFB0 colonies, but we did observe a 9-fold increase in P. larvae abundance in AFB2 relative to the abundance in AFB1. The relative sequence numbers of Citrobacter freundii and Hafnia alvei were higher in AFB2 and AFB1 than in AFB0, whereas Enterococcus faecalis, Klebsiella oxytoca, Spiroplasma melliferum and Morganella morganii were more abundant in AFB0 and AFB1 than in AFB2.

Biosorption of Ag(I) from aqueous solutions by Klebsiella sp. 3S1.

PubMed

Muñoz, Antonio Jesús; Espínola, Francisco; Ruiz, Encarnación

2017-05-05

This study investigated the potential ability of Klebsiella sp. 3S1 to remove silver cations from aqueous solutions. The selected strain is a ubiquitous bacterium selected from among several microorganisms that had been isolated from wastewaters. To optimise the operating conditions in the biosorption process, a Rotatable Central Composite Experimental Design was developed establishing pH, temperature and biomass concentration as independent variables. Interaction mechanisms involved were analysed through kinetic and equilibrium studies. The experimental results suit pseudo-second order kinetics with two biosorption stages, being the first almost instantly. The Langmuir equilibrium model predicted a maximum capacity of biosorption (q) of 114.1mg Ag/g biomass. The study of the mechanisms involved in the biosorption was completed by employing advanced techniques which revealed that both bacterium-surface interactions and intracellular bioaccumulation participate in silver removal from aqueous solutions. The ability of Klebsiella sp. 3S1 to form silver chloride nanoparticles with interesting potential applications was also discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of Cd-resistant Klebsiella michiganensis MCC3089 and its potential for rice seedling growth promotion under Cd stress.

PubMed

Mitra, Soumik; Pramanik, Krishnendu; Ghosh, Pallab Kumar; Soren, Tithi; Sarkar, Anumita; Dey, Ramendra Sundar; Pandey, Sanjeev; Maiti, Tushar Kanti

2018-05-01

Application of heavy metal resistant plant growth promoting rhizobacteria has an important role as they help to evade metal-induced toxicity in plants on one hand and enhance plant growth on the other. The present study is therefore focused on the characterization of a cadmium resistant bacterial strain isolated from heavy metal contaminated rhizospheric soil designated as S8. This S8 strain was selected in terms of cadmium resistance and plant growth promoting traits. Moreover, it also showed resistance to lead and arsenic to a considerable extent. The selected strain S8 was identified as Klebsiella michiganensis by modern approaches of bacterial taxonomy. The plant growth promoting traits exhibited by the strain include 1-aminocyclopropane-1-carboxylic acid deaminase activity (58.33 ng α-keto butyrate/mg protein/h), Indole-3-acetic acid production (671 μg/ml), phosphate solubilization (71.98 ppm), nitrogen fixation (3.72 μg of nitrogen fixed/h/mg protein) etc. Besides, the strain also exhibited high cadmium removal efficiency (73-97%) from the medium and intracellular accumulation as well. Its efficiency to alleviate cadmium-induced toxicity was determined against a rice cultivar in terms of morphological and biochemical changes. Enhanced growth and reduced oxidative stress were detected in presence of the bacterium. On the basis of these results, it can be concluded that K. michiganensis strain S8 is cadmium accumulating plant growth promoting rhizobacterium that can be applied in cadmium contaminated agricultural soil to achieve better productivity of rice. Copyright © 2018 Elsevier GmbH. All rights reserved.

Bacterial-resistance among outpatients of county hospitals in China: significant geographic distinctions and minor differences between central cities.

PubMed

Xiao, Yonghong; Wei, Zeqing; Shen, Ping; Ji, Jinru; Sun, Ziyong; Yu, Hua; Zhang, Tiantuo; Ji, Ping; Ni, Yuxing; Hu, Zhidong; Chu, Yunzhuo; Li, Lanjuan

2015-06-01

The purpose of this study was to survey antibacterial resistance in outpatients of Chinese county hospitals. A total of 31 county hospitals were selected and samples continuously collected from August 2010 to August 2011. Drug sensitivity testing was conducted in a central laboratory. A total of 2946 unique isolates were collected, including 634 strains of Escherichia coli, 606 Klebsiella pneumoniae, 476 Staphylococcus aureus, 308 Streptococcus pneumoniae, and 160 Haemophilus influenzae. Extended-spectrum β-lactamases were detected in E. coli (42.3% strains), K. pneumoniae (31.7%), and Proteus mirabilis (39.0%). Ciprofloxacin-resistance was detected in 51.0% of E. coli strains. Salmonella spp. and Shigella spp. were sensitive to most antibacterial agents. Less than 8.0% of Pseudomonas aeruginosa isolates were resistant to carbapenem. For S. aureus strains, 15.3% were resistant to methicillin, and some strains of S. pneumoniae showed resistance to penicillin (1.6%), ceftriaxone (13.0%), and erythromycin (96.4%). β-lactamase was produced by 96.5% of Moraxella catarrhalis strains, and 36.2% of H. influenzae isolates were resistant to ampicillin. Azithromycin-resistant H. influenzae, imipenem-resistant but meropenem-sensitive Proteus, and ceftriaxone- and carbapenem non-sensitive M. catarrhalis were recorded. In conclusion, cephalosporin- and quinolone-resistant strains of E. coli and Klebsiella pneumonia and macrolide-resistant Gram-positive cocci were relatively prominent in county hospitals. The antibacterial resistance profiles of isolates from different geographical locations varied significantly, with proportions in county hospitals lower than those in their tertiary counterparts in the central cities, although the difference is diminishing. Copyright © 2015 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

[Susceptibility to antimicrobial agents of 2,060 strains of different bacteria isolated in infectious processes in children].

PubMed

Filloy, L; Borjas, E; Sierra, A

1981-01-01

Susceptibility to antibiotics of 2060 strains of the following bacteria was studied: Escherichia coli, Klebsiella pneumoniae, Salmonella, Shigella, Proteus, Staphylococcus aureus that were isolated in 1978-79 from different infections in children hospitalized at the Hospital Infantil de Mexico. The antimicrobials submitted to the test of susceptibility were: ampicillin, amikacin, carbenicillin, cephalothin, cefoxitin, chloramphenicol, gentamicin, kanamycin, neomycin and sulfamethoxazole-trimethoprim. Present results are compared with previous studies.

Genetic evolution and clinical impact in extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae.

PubMed

Chong, Yong; Ito, Yoshikiyo; Kamimura, Tomohiko

2011-10-01

The emergence of extended-spectrum β-lactamase (ESBL)-producing bacteria, particularly Escherichia coli and Klebsiella pneumoniae, is now a critical concern for the development of therapies against bacterial infection. ESBLs consist of three major genetic groups: TEM, SHV, and CTX-M types. Nosocomial infections due to TEM and SHV-producing K. pneumoniae strains were frequently documented until the late 1990s. The number of reports on community-acquired infections caused by CTX-M-producing E. coli strains have dramatically increased over the last decade; however, K. pneumoniae strains, of either the TEM or SHV types, are persistent and important ESBL producers. The spread of ESBL genes is associated with various mobile genetic elements, such as transposons, insertion sequences, and integrons. The rapid dissemination of ESBL genes of the CTX-M type may be related to highly complicated genetic structures. These structures harboring ESBL genes and mobile elements are found in a variety of plasmids, which often carry many other antibiotic resistance genes. Multidrug-resistant CTX-M-15-producing E. coli strains disseminate worldwide. Efficient mobile elements and plasmids may have accelerated the genetic diversity and the rapid spread of ESBL genes, and their genetic evolution has caused an emerging threat to the bacteria for which few effective drugs have been identified. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparative whole genome transcriptome and metabolome analyses of five Klebsiella pneumonia strains.

PubMed

Lee, Soojin; Kim, Borim; Yang, Jeongmo; Jeong, Daun; Park, Soohyun; Shin, Sang Heum; Kook, Jun Ho; Yang, Kap-Seok; Lee, Jinwon

2015-11-01

The integration of transcriptomics and metabolomics can provide precise information on gene-to-metabolite networks for identifying the function of novel genes. The goal of this study was to identify novel gene functions involved in 2,3-butanediol (2,3-BDO) biosynthesis by a comprehensive analysis of the transcriptome and metabolome of five mutated Klebsiella pneumonia strains (∆wabG = SGSB100, ∆wabG∆budA = SGSB106, ∆wabG∆budB = SGSB107, ∆wabG∆budC = SGSB108, ∆wabG∆budABC = SGSB109). First, the transcriptomes of all five mutants were analyzed and the genes exhibiting reproducible changes in expression were determined. The transcriptome was well conserved among the five strains, and differences in gene expression occurred mainly in genes coding for 2,3-BDO biosynthesis (budA, budB, and budC) and the genes involved in the degradation of reactive oxygen, biosynthesis and transport of arginine, cysteine biosynthesis, sulfur metabolism, oxidoreductase reaction, and formate dehydrogenase reaction. Second, differences in the metabolome (estimated by carbon distribution, CO2 emission, and redox balance) among the five mutant strains due to gene alteration of the 2,3-BDO operon were detected. The functional genomics approach integrating metabolomics and transcriptomics in K. Pneumonia presented here provides an innovative means of identifying novel gene functions involved in 2,3-BDO biosynthesis metabolism and whole cell metabolism.

In vitro activity of ceftiofur tested against clinical isolates of Escherichia coli and Klebsiella pneumoniae including extended spectrum beta-lactamase producing strains.

PubMed

Deshpande, L; Pfaller, M A; Jones, R N

2000-08-01

In vitro activity of ceftiofur, a cephalosporin used in veterinary practice was compared using ceftriaxone-resistant (producing extended spectrum beta-lactamase (ESBL)) and -susceptible clinical isolates of Esherichia coli and Klebsiella pneumoniae. The ceftriaxone-susceptible isolates exhibited a lower range of ceftiofur MICs (MIC50, 0.5 mg/l, MIC90 1.0 mg/l). Those isolates known to produce an ESBL were also resistant to ceftiofur (MIC50, > or = 32 mg/l). The latter isolates were also less susceptible to other comparator drugs (cefquinome, gentamicin and trimethoprim/sulphamethoxazole) in contrast to the ceftriaxone-susceptible strains. The clinical isolates showed high correlation between ceftriaxone and ceftiofur MICs (y = 2.6 + 0.89x, r = 0.95). Using the current ceftiofur susceptible breakpoint (< or = 2 mg/l) used for veterinary practice (respiratory tract pathogens), the ESBL-producing strains of E. coli and K. pneumoniae could be accurately separated from susceptible strains. This ceftiofur breakpoint MIC corresponds to the National Committee for Clinical Laboratory Standards ESBL screening concentration for ceftriaxone set at < or = 1 mg/l = negative for ESBL production. Ceftiofur was also observed to be very active in vitro against ampicillin-resistant, non-ESBL producing enteric isolates. This new cephem appears to be very potent against the tested Enterobacteriaceae and of potential wide clinical veterinary utility.

Tannic acid degradation by Klebsiella strains isolated from goat feces

PubMed Central

Tahmourespour, Arezoo; Tabatabaee, Nooroldin; Khalkhali, Hossein; Amini, Imane

2016-01-01

Background and Objectives: Tannins are toxic polyphenols that either bind and precipitate or condense proteins. The high tannin content of some plants is the preliminary limitation of using them as a ruminant feed. So, the aim of this study was the isolation and characterization of tannic acid degrading bacterial strains from goat feces before and after feeding on Pistachio-Soft Hulls as tannin rich diet (TRD). Materials and Methods: Bacterial strains capable of utilizing tannic acid as sole carbon and energy source were isolated and characterized from goat feces before and after feeding on TRD. Tannase activity, maximum tolerable concentration and biodegradation potential were assessed. Results: Four tannase positive isolates were identified as Klebsiella pneumoniae. Isolated strains showed the maximum tolerable concentration of 64g/L of tannin. The tannic acid degradation percentage at a concentration of 15.0 g/L reached a maximum of 68% after 24 h incubation, and more than 98% after 72 h incubation. The pH of the medium also decreased along with tannic acid utilization. Conclusions: It is obvious that TRD induced adaptive responses. Thus, while the bacteria were able to degrade and detoxify the tannic acids, they had to adapt in the presence of high concentrations of tannic acid. So, these isolates have an amazing potential for application in bioremediation, waste water treatment, also reduction of tannins antinutritional effects in animal feeds. PMID:27092220

Outbreak of Colistin-Resistant, Carbapenemase-Producing Klebsiella pneumoniae: Are We at the End of the Road?

PubMed

van Duin, David; Doi, Yohei

2015-10-01

Carbapenem-resistant Klebsiella pneumoniae strains that produce K. pneumoniae carbapenemase (KPC) have spread globally in the last decade. Colistin is a key agent in treating infections caused by this pathogen. In this issue of the Journal of Clinical Microbiology, Giani et al. (T. Giani, F. Arena, G. Vaggelli, V. Conte, A Chiarell, L. H. De Angelis, R. Fornaini, M. Grazzini, F. Niccolini, P. Pecile, and G. M. Rossolini, J Clin Microbiol 53:3341-3344, 2015, http://dx.doi.org/10.1128/JCM.01017-15) describe a sustained outbreak of colistin-resistant KPC-producing K. pneumoniae. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Understanding, preventing and eradicating Klebsiella pneumoniae biofilms.

PubMed

Ribeiro, Suzana Meira; Cardoso, Marlon Henrique; Cândido, Elizabete de Souza; Franco, Octávio Luiz

2016-01-01

The ability of pathogenic bacteria to aggregate and form biofilm represents a great problem for public health, since they present extracellular components that encase these micro-organisms, making them more resistant to antibiotics and host immune attack. This may become worse when antibiotic-resistant bacterial strains form biofilms. However, antibiofilm screens with different compounds may reveal potential therapies to prevent/treat biofilm infections. Here, we focused on Klebsiella pneumoniae, an opportunistic bacterium that causes different types of infections, including in the bloodstream, meninges, lungs, urinary system and at surgical sites. We also highlight aspects involved in the formation and maintenance of K. pneumoniae biofilms, as well as resistance and the emergence of new trends to combat this health challenge.

Genomic and Functional Characterization of qnr-Encoding Plasmids from Municipal Wastewater Biosolid Klebsiella pneumoniae Isolates

PubMed Central

Kaplan, Ella; Sela, Noa; Doron-Faigenboim, Adi; Navon-Venezia, Shiri; Jurkevitch, Edouard; Cytryn, Eddie

2015-01-01

Municipal wastewater treatment facilities are considered to be “hotspots” for antibiotic resistance, since they conjoin high densities of environmental and fecal bacteria with selective pressure in the form of sub-therapeutic concentrations of antibiotics. Discharged effluents and biosolids from these facilities can disseminate antibiotic resistant genes to terrestrial and aquatic environments, potentially contributing to the increasing global trend in antibiotic resistance. This phenomenon is especially pertinent when resistance genes are associated with mobile genetic elements such as conjugative plasmids, which can be transferred between bacterial phyla. Fluoroquinolones are among the most abundant antibiotic compounds detected in wastewater treatment facilities, especially in biosolids, where due to their hydrophobic properties they accumulate to concentrations that may exceed 40 mg/L. Although fluoroquinolone resistance is traditionally associated with mutations in the gyrA/topoisomerase IV genes, there is increasing evidence of plasmid-mediated quinolone resistance, which is primarily encoded on qnr genes. In this study, we sequenced seven qnr-harboring plasmids from a diverse collection of Klebsiella strains, isolated from dewatered biosolids from a large wastewater treatment facility in Israel. One of the plasmids, termed pKPSH-11XL was a large (185.4 kbp), multi-drug resistance, IncF-type plasmid that harbored qnrB and 10 additional antibiotic resistance genes that conferred resistance to five different antibiotic families. It was highly similar to the pKPN3-like plasmid family that has been detected in multidrug resistant clinical Klebsiella isolates. In contrast, the six additional plasmids were much smaller (7–9 Kbp) and harbored a qnrS -type gene. These plasmids were highly similar to each other and closely resembled pGNB2, a plasmid isolated from a German wastewater treatment facility. Comparative genome analyses of pKPSH-11XL and other pKPN3-like plasmids concomitant to phylogenetic analysis of housekeeping genes from host Klebsiella strains, revealed that these plasmids are limited to a predominantly human-associated sub-clade of Klebsiella, suggesting that their host range is very narrow. Conversely, the pGNB2-like plasmids had a much broader host range and appeared to be associated with Klebsiella residing in natural environments. This study suggests that: (A) qnrB-harboring multidrug-resistant pKPN3-like plasmids can endure the rigorous wastewater treatment process and may therefore be disseminated to downstream environments; and (B) that small qnrS-harboring pGNB2-like plasmids are ubiquitous in wastewater treatment facilities and are most likely environmental in origin. PMID:26696974

Genomic and Functional Characterization of qnr-Encoding Plasmids from Municipal Wastewater Biosolid Klebsiella pneumoniae Isolates.

PubMed

Kaplan, Ella; Sela, Noa; Doron-Faigenboim, Adi; Navon-Venezia, Shiri; Jurkevitch, Edouard; Cytryn, Eddie

2015-01-01

Municipal wastewater treatment facilities are considered to be "hotspots" for antibiotic resistance, since they conjoin high densities of environmental and fecal bacteria with selective pressure in the form of sub-therapeutic concentrations of antibiotics. Discharged effluents and biosolids from these facilities can disseminate antibiotic resistant genes to terrestrial and aquatic environments, potentially contributing to the increasing global trend in antibiotic resistance. This phenomenon is especially pertinent when resistance genes are associated with mobile genetic elements such as conjugative plasmids, which can be transferred between bacterial phyla. Fluoroquinolones are among the most abundant antibiotic compounds detected in wastewater treatment facilities, especially in biosolids, where due to their hydrophobic properties they accumulate to concentrations that may exceed 40 mg/L. Although fluoroquinolone resistance is traditionally associated with mutations in the gyrA/topoisomerase IV genes, there is increasing evidence of plasmid-mediated quinolone resistance, which is primarily encoded on qnr genes. In this study, we sequenced seven qnr-harboring plasmids from a diverse collection of Klebsiella strains, isolated from dewatered biosolids from a large wastewater treatment facility in Israel. One of the plasmids, termed pKPSH-11XL was a large (185.4 kbp), multi-drug resistance, IncF-type plasmid that harbored qnrB and 10 additional antibiotic resistance genes that conferred resistance to five different antibiotic families. It was highly similar to the pKPN3-like plasmid family that has been detected in multidrug resistant clinical Klebsiella isolates. In contrast, the six additional plasmids were much smaller (7-9 Kbp) and harbored a qnrS -type gene. These plasmids were highly similar to each other and closely resembled pGNB2, a plasmid isolated from a German wastewater treatment facility. Comparative genome analyses of pKPSH-11XL and other pKPN3-like plasmids concomitant to phylogenetic analysis of housekeeping genes from host Klebsiella strains, revealed that these plasmids are limited to a predominantly human-associated sub-clade of Klebsiella, suggesting that their host range is very narrow. Conversely, the pGNB2-like plasmids had a much broader host range and appeared to be associated with Klebsiella residing in natural environments. This study suggests that: (A) qnrB-harboring multidrug-resistant pKPN3-like plasmids can endure the rigorous wastewater treatment process and may therefore be disseminated to downstream environments; and (B) that small qnrS-harboring pGNB2-like plasmids are ubiquitous in wastewater treatment facilities and are most likely environmental in origin.

Mutant prevention concentrations of four carbapenems against gram-negative rods.

PubMed

Credito, Kim; Kosowska-Shick, Klaudia; Appelbaum, Peter C

2010-06-01

We tested the propensities of four carbapenems to select for resistant Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii mutants by determining the mutant prevention concentrations (MPCs) for 100 clinical strains with various ss-lactam phenotypes. Among the members of the Enterobacteriaceae family and A. baumannii strains, the MPC/MIC ratios were mostly 2 to 4. In contrast, for P. aeruginosa the MPC/MIC ratios were 4 to > or =16. The MPC/MIC ratios for beta-lactamase-positive K. pneumoniae and E. coli isolates were much higher (range, 4 to >16 microg/ml) than those for ss-lactamase-negative strains.

Antimicrobial and anti-inflammatory activities of Pleurostylia capensis Turcz (Loes) (celastraceae).

PubMed

Razwinani, Mapula; Tshikalange, Thilivhali Emmanuel; Motaung, Shirley C K M

2014-01-01

Pleurostylia capensis is a large tree that can reach the maximum height of 20 m long, and it have been traditionally used as cosmetic, for steam bath, ritual body wash, and as a purgative to treat symptoms of witchcraft. Using ethanol, chloroform, dichloromethane (DCM), ethyl acetate (EA), and water extracts, leaves, bark and roots of Pleurostylia capensis were investigated scientifically for their effectiveness in antimicrobial, antioxidant and anti-inflammatory activities using standard methods. The extracts were evaluated for antimicrobial activity against Gram positive (Staphylococcus aureus, Bacillus cereus, and Mycobacterium smegmatis), Gram negative (Escherichia coli, Klebsiella pneumonia, Klebsiella oxytoca, Streptococcus pyogenes, Pseudomonas aeruginosa and Salmonella typhimurium), and Candida albicans. The antioxidant activity was investigated using 2, 2-diphenlyl-1-picrylhadrazyl (DPPH), free radical scavenging assay. The anti-inflammatory activity of P. capensis extracts was evaluated against both cyclooxygenase enzymes (COX 1 and 2). The ethyl acetate extracts of P. capensis showed a strong antimicrobial activity against B. cereus, K. pneumonia, S. pyogenes, and M. smegmatis with MIC value of 0.39 and 0.78 mg/ml. While the ethanol bark extract was most active against M. smegmatis with MIC value of 0.78 mg/ml; the least potent activity was observed with dichloromethane, chloroform and water extracts, with an MIC value ranging from 1.56 mg/ml to 50.0 mg/ml. The plant extracts proved to be good antioxidant agent, whereas extracts of ethanol were the most active, with IC50 ranging from 1.00 to 1.74 µg/ml, which is lower, and in close range to Vitamin C (1.40 µg/ml). Its moderation to potent inhibitory activity was observed in all extracts. Ethanol and dichloromethane extracts were among the most potent when compared to water and petroleum ether extracts. The water extracts showed to be nontoxic on the Hek cell line with an IC50 value of 204.0, and 207.3 µg/ml (roots and bark) respectively. The dichloromethane, ethyl acetate, chloroform and ethanol extracts showed to be toxic on the Hek cell, with IC50 range from 5.94 to 42.91µg/ml. The results obtained indicate the effectiveness of these plants.

Performance evaluation of three automated identification systems in detecting carbapenem-resistant Enterobacteriaceae.

PubMed

He, Qingwen; Chen, Weiyuan; Huang, Liya; Lin, Qili; Zhang, Jingling; Liu, Rui; Li, Bin

2016-06-21

Carbapenem-resistant Enterobacteriaceae (CRE) is prevalent around the world. Rapid and accurate detection of CRE is urgently needed to provide effective treatment. Automated identification systems have been widely used in clinical microbiology laboratories for rapid and high-efficient identification of pathogenic bacteria. However, critical evaluation and comparison are needed to determine the specificity and accuracy of different systems. The aim of this study was to evaluate the performance of three commonly used automated identification systems on the detection of CRE. A total of 81 non-repetitive clinical CRE isolates were collected from August 2011 to August 2012 in a Chinese university hospital, and all the isolates were confirmed to be resistant to carbapenems by the agar dilution method. The potential presence of carbapenemase genotypes of the 81 isolates was detected by PCR and sequencing. Using 81 clinical CRE isolates, we evaluated and compared the performance of three automated identification systems, MicroScan WalkAway 96 Plus, Phoenix 100, and Vitek 2 Compact, which are commonly used in China. To identify CRE, the comparator methodology was agar dilution method, while the PCR and sequencing was the comparator one to identify CPE. PCR and sequencing analysis showed that 48 of the 81 CRE isolates carried carbapenemase genes, including 23 (28.4 %) IMP-4, 14 (17.3 %) IMP-8, 5 (6.2 %) NDM-1, and 8 (9.9 %) KPC-2. Notably, one Klebsiella pneumoniae isolate produced both IMP-4 and NDM-1. One Klebsiella oxytoca isolate produced both KPC-2 and IMP-8. Of the 81 clinical CRE isolates, 56 (69.1 %), 33 (40.7 %) and 77 (95.1 %) were identified as CRE by MicroScan WalkAway 96 Plus, Phoenix 100, and Vitek 2 Compact, respectively. The sensitivities/specificities of MicroScan WalkAway, Phoenix 100 and Vitek 2 were 93.8/42.4 %, 54.2/66.7 %, and 75.0/36.4 %, respectively. The MicroScan WalkAway and Viteck2 systems are more reliable in clinical identification of CRE, whereas additional tests are required for the Pheonix 100 system. Our study provides a useful guideline for using automated identification systems for CRE identification.

Decontamination and survival of Enterobacteriaceae on shredded iceberg lettuce during storage.

PubMed

Osaili, Tareq M; Alaboudi, Akram R; Al-Quran, Heba N; Al-Nabulsi, Anas A

2018-08-01

Enterobacteriaceae family can contaminate fresh produce at any stage of production either at pre-harvest or post-harvest stages. The objectives of the current study were to i) identify Enterobacteriaceae species on iceberg lettuce, ii) compare the decontamination efficiency of water, sodium hypochlorite (free chlorine 200 ppm), peroxyacetic acid (PA 80 ppm; Kenocid 2100 ® ) or their combinations and ionizing radiation against Enterobacteriaceae on shredded iceberg lettuce and iii) determine the survival of Enterobacteriaceae post-treatment storage of shredded iceberg lettuce at 4, 10 and 25 °C, for up to 7 days. Klebsiella pneumonia spp. pneumonia, Enterobacter cloacae, Klebsiella oxytoca, Pantoea spp., Leclercia adecarboxylata and Kluyvera ascorbate were identified on iceberg lettuce. No significant difference (P≥ 0.05) among Enterobacteriaceae survival after washing with water or sanitizing with sodium hypochlorite or Kenocid 2100 ® (reduction ≤ 0.6 log CFU/g) were found. Combined sanitizer treatments were more effective against Enterobacteriaceae than single washing/sanitizing treatments. Sanitization of iceberg lettuce with combined washing/sanitizing treatments reduced Enterobacteriaceae by 0.85-2.24 CFU/g. Post-treatment growth of Enterobacteriaceae during storage on samples sanitized with sodium hypochlorite and Kenocid 2100 ® was more than on samples washed with water. The D 10 -value of Enterobacteriaceae on shredded iceberg lettuce was 0.21 KGy. The reduction of Enterobacteriaceae populations on iceberg after gamma radiation (0.6 KGy) was 3 log CFU/g, however, Enterobacteriaceae counts increased post-irradiation storage by 4-5 log CFU/g. Therefore, washing shredded iceberg lettuce with combined sanitizing treatment (sodium hypochlorite/sodium hypochlorite, sodium hypochlorite/Kenocid 2100 ® , or Kenocid 2100 ® /Kenocid 2100 ® ) for total time of 6 min or exposing it to gamma irradiation (0.6 KGy) can decrease the risk of Enterobacteriaceae (reduction ≥ 2 log). Post-washing storage of sliced iceberg lettuce (4, 10, 25 °C) could increase the risk of Enterobacteriaceae as their counts increased during storage even at low temperatures. Copyright © 2018 Elsevier Ltd. All rights reserved.

TEM Derivative-Producing Enterobacter aerogenes Strains: Dissemination of a Prevalent Clone

PubMed Central

Dumarche, P.; De Champs, C.; Sirot, D.; Chanal, C.; Bonnet, R.; Sirot, J.

2002-01-01

TEM-24 (CAZ-6) extended-spectrum β-lactamase (ESBL) was detected in 1988 in Clermont-Ferrand, France, in Klebsiella pneumoniae (blaTEM-24) and Enterobacter aerogenes (blaTEM-24b), and since 1994, a TEM-24-producing E. aerogenes clonal strain has been observed elsewhere in the country. To determine if the spread of this clonal strain was restricted to TEM-24-producing E. aerogenes strains, 84 E. aerogenes strains (non-TEM/SHV-producing strains, TEM-1- or -2-producing strains, and different ESBL-producing strains), isolated from 1988 to 1999 in Clermont-Ferrand (n = 59) and in 11 other French hospitals in 1998 (n = 25), were studied. A clonal strain was found for TEM-24- but also for TEM-3- and TEM-1- or 2-producing isolates. This study shows that there is a clonal strain dependent on acquisition of the TEM-type enzyme (TEM-24 and other TEM types). PMID:11897606

DOE Office of Scientific and Technical Information (OSTI.GOV)

Compere, A.L.; Griffith, W.L.

The production was evaluated of ethanol, acetone, and butanol from several different carbohydrate materials by five strains of Clostridia and two mixed cultures. The substrates, which were tested at concn ranging between 2.5 and 10% w/v, included pentoses, hexoses, disaccharides, and polysaccharides. The organisms used were Clostridium acetobutylicum strains NRRL B527 and NRRL B3179; Clostridium butylicum strains NRRL B592 and NRRL B593; and Clostridium pasteurianum strain NRRL B598. The mixed cultures contained all of these organisms. Mixed culture 1 contained in addition to the Clostridia, Klebsiella pneumoniae strain NRRL B427. Mixed culture 2 contained mixed culture 1 plus a yeastmore » isolated from kefir culture. Where possible, maxima were found for the conversion of different substrates. 7 tables.« less

Isolation and characterization of phosphate-solubilizing bacteria from seagrass rhizosphere soil

NASA Astrophysics Data System (ADS)

Ghosh, Upasana; Subhashini, Ponnambalam; Dilipan, Elangovan; Raja, Subramanian; Thangaradjou, Thirunavukarassu; Kannan, Lakshmanan

2012-03-01

Phosphate-solubilizing bacterial strains (6 Nos.) were isolated from the rhizosphere soils of two seagrasses ( Halophila ovalis (R. Br.) Hook and Halodule pinifolia (Miki) Hartog) in the Vellar estuary. Experimental studies found that the strain PSSG6 was effective in phosphate solubilization with Phosphate Solubilization efficiency index E = 375 ± 8.54, followed by the strain PSSG5 with Phosphate Solubilization efficiency index E = 275 ± 27.3. Of the 6 strains isolated, the strains PSSG4 and PSSG5 belonged to the genus Bacillus, and PSSG1, PSSG2 and PSSG3 were identified as Citrobacter sp., Shigella sp., and Klebsiella sp., respectively, by conventional method, and PSSG6 was identified as Bacillus circulans using conventional and molecular methods.

Isolation of Bdellovibrio sp. from soil samples in Mexico and their potential applications in control of pathogens.

PubMed

Oyedara, Omotayo Opemipo; De Luna-Santillana, Erick de Jesus; Olguin-Rodriguez, Omar; Guo, Xianwu; Mendoza-Villa, Marco Antonio; Menchaca-Arredondo, Jorge Luis; Elufisan, Temidayo Oluyomi; Garza-Hernandez, Javier Alfonso; Garcia Leon, Israel; Rodriguez-Perez, Mario Alberto

2016-12-01

In this study, two strains of Bdellovibrio were isolated from soil samples using the culture-dependent technique and two members of the family Enterobacteriaceae (Klebsiella sp. and Salmonella sp.) as prey. The Bdellovibrio strains were bacteriolytic, plaque-forming, and highly motile gram-negative bacteria. We identified and confirmed the Bdellovibrio strains using microscopy, PCR amplification, and sequencing of the 16S rRNA gene. They were observed to be different strains based on hit locus and prey range analyses. Here, the first report on Bdellovibrio strains isolated from soil in Mexico corroborates earlier report indicating that populations of Bdellovibrio found in soil are heterogeneous thereby the need to identify the various strains. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Comparative analysis of CRISPR-Cas systems in Klebsiella genomes.

PubMed

Shen, Juntao; Lv, Li; Wang, Xudong; Xiu, Zhilong; Chen, Guoqiang

2017-04-01

Prokaryotic CRISPR-Cas system provides adaptive immunity against invasive genetic elements. Bacteria of the genus Klebsiella are important nosocomial opportunistic pathogens. However, information of CRISPR-Cas system in Klebsiella remains largely unknown. Here, we analyzed the CRISPR-Cas systems of 68 complete genomes of Klebsiella representing four species. All the elements for CRISPR-Cas system (cas genes, repeats, leader sequences, and PAMs) were characterized. Besides the typical Type I-E and I-F CRISPR-Cas systems, a new Subtype I system located in the ABC transport system-glyoxalase region was found. The conservation of the new subtype CRISPR system between different species showed new evidence for CRISPR horizontal transfer. CRISPR polymorphism was strongly correlated both with species and multilocus sequence types. Some results indicated the function of adaptive immunity: most spacers (112 of 124) matched to prophages and plasmids and no matching housekeeping genes; new spacer acquisition was observed within the same sequence type (ST) and same clonal complex; the identical spacers were observed only in the ancient position (far from the leader) between different STs and clonal complexes. Interestingly, a high ratio of self-targeting spacers (7.5%, 31 of 416) was found in CRISPR-bearing Klebsiella pneumoniae (61%, 11 of 18). In some strains, there even were multiple full matching self-targeting spacers. Some self-targeting spacers were conserved even between different STs. These results indicated that some unknown mechanisms existed to compromise the function of self-targets of CRISPR-Cas systems in K. pneumoniae. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cloning of a Novel Aldo-Keto Reductase Gene from Klebsiella sp. Strain F51-1-2 and Its Functional Expression in Escherichia coli▿

PubMed Central

Jiang, Hong; Yang, Chao; Qu, Hong; Liu, Zheng; Fu, Q. S.; Qiao, Chuanling

2007-01-01

A soil bacterium capable of metabolizing organophosphorus compounds by reducing the P=S group in the molecules was taxonomically identified as Klebsiella sp. strain F51-1-2. The gene involved in the reduction of organophosphorus compounds was cloned from this strain by the shotgun technique, and the deduced protein (named AKR5F1) showed homology to members of the aldo-keto reductase (AKR) superfamily. The intact coding region for AKR5F1 was subcloned into vector pET28a and overexpressed in Escherichia coli BL21(DE3). Recombinant His6-tagged AKR5F1 was purified in one step using Ni-nitrilotriacetic acid affinity chromatography. Assays for cofactor specificity indicated that reductive transformation of organophosphorus compounds by the recombinant AKR5F1 specifically required NADH. The kinetic constants of the purified recombinant AKR5F1 toward six thion organophosphorus compounds were determined. For example, the Km and kcat values of reductive transformation of malathion by the purified recombinant AKR5F1 are 269.5 ± 47.0 μΜ and 25.7 ± 1.7 min−1, respectively. Furthermore, the reductive transformation of organophosphorus compounds can be largely explained by structural modeling. PMID:17575004

Antibody-Mediated Killing of Carbapenem-Resistant ST258 Klebsiella pneumoniae by Human Neutrophils

PubMed Central

Kobayashi, Scott D.; Porter, Adeline R.; Freedman, Brett; Pandey, Ruchi; Chen, Liang; Kreiswirth, Barry N.

2018-01-01

ABSTRACT Carbapenem-resistant Klebsiella pneumoniae is a problem worldwide. A carbapenem-resistant K. pneumoniae lineage classified as multilocus sequence type 258 (ST258) is prominent in the health care setting in many regions of the world, including the United States. ST258 strains can be resistant to virtually all clinically useful antibiotics; treatment of infections caused by these organisms is difficult, and mortality is high. As a step toward promoting development of new therapeutics for ST258 infections, we tested the ability of rabbit antibodies specific for ST258 capsule polysaccharide to enhance human serum bactericidal activity and promote phagocytosis and killing of these bacteria by human neutrophils. We first demonstrated that an isogenic wzy deletion strain is significantly more susceptible to killing by human heparinized blood, serum, and neutrophils than a wild-type ST258 strain. Consistent with the importance of capsule as an immune evasion molecule, rabbit immune serum and purified IgG specific for ST258 capsule polysaccharide type 2 (CPS2) enhanced killing by human blood and serum in vitro. Moreover, antibodies specific for CPS2 promoted phagocytosis and killing of ST258 by human neutrophils. Collectively, our findings suggest that ST258 CPS2 is a viable target for immunoprophylactics and/or therapeutics. PMID:29535199

Preliminary Study on the Antibacterial Activity of Essential Oils Alone and in Combination with Gentamicin Against Extended-Spectrum β-Lactamase-Producing and New Delhi Metallo-β-Lactamase-1-Producing Klebsiella pneumoniae Isolates.

PubMed

Kwiatkowski, Paweł; Pruss, Agata; Grygorcewicz, Bartłomiej; Wojciuk, Bartosz; Dołęgowska, Barbara; Giedrys-Kalemba, Stefania; Kochan, Ewa; Sienkiewicz, Monika

2018-04-30

The aim of the study was to investigate possible synergistic effects between several selected, commercially available essential oils and gentamicin against extended-spectrum β-lactamase (ESBL)-producing and New Delhi metallo-β-lactamase-1 (NDM-1)-producing Klebsiella pneumoniae isolates. ESBLs production was confirmed by double-disk synergy test. Isolates positive for bla NDM-1 gene were found among the tested strains. K. pneumoniae ATCC ® BAA-1705™ strain was used as a control. The checkerboard method was applied to assess the synergistic and additive action of nine essential oils: caraway, fennel, peppermint, geranium, basil, clove, thyme, clary sage, and lavender, respectively, in combination with gentamicin. Our results indicated that peppermint oil combined with gentamicin showed synergistic activity against both control, ESBL-producing and NDM-1-producing isolates. Caraway essential oil demonstrated synergy with gentamicin toward ESBL-producing and additionally gentamicin-resistant strains. The additive effect was observed for gentamicin combined with thyme, fennel, basil, and clary sage. Because of their synergistic activity with gentamicin, peppermint, and caraway oils in particular, can be considered as an alternative or an addition for the control of infections with limited therapeutic options due to multidrug resistance.

Effects of Space Environment on Genome, Transcriptome, and Proteome of Klebsiella pneumoniae.

PubMed

Guo, Yinghua; Li, Jia; Liu, Jinwen; Wang, Tong; Li, Yinhu; Yuan, Yanting; Zhao, Jiao; Chang, De; Fang, Xiangqun; Li, Tianzhi; Wang, Junfeng; Dai, Wenkui; Fang, Chengxiang; Liu, Changting

2015-11-01

The aim of this study was to explore the effects of space flight on Klebsiella pneumoniae. A strain of K. pneumoniae was sent to space for 398 h aboard the ShenZhou VIII spacecraft during November 1, 2011-November 17, 2011. At the same time, a ground simulation with similar temperature conditions during the space flight was performed as a control. After the space mission, the flight and control strains were analyzed using phenotypic, genomic, transcriptomic and proteomic techniques. The flight strains LCT-KP289 exhibited a higher cotrimoxazole resistance level and changes in metabolism relative to the ground control strain LCT-KP214. After the space flight, 73 SNPs and a plasmid copy number variation were identified in the flight strain. Based on the transcriptomic analysis, there are 232 upregulated and 1879 downregulated genes, of which almost all were for metabolism. Proteomic analysis revealed that there were 57 upregulated and 125 downregulated proteins. These differentially expressed proteins had several functions that included energy production and conversion, carbohydrate transport and metabolism, translation, ribosomal structure and biogenesis, posttranslational modification, protein turnover, and chaperone functions. At a systems biology level, the ytfG gene had a synonymous mutation that resulted in significantly downregulated expression at both transcriptomic and proteomic levels. The mutation of the ytfG gene may influence fructose and mannose metabolic processes of K. pneumoniae during space flight, which may be beneficial to the field of space microbiology, providing potential therapeutic strategies to combat or prevent infection in astronauts. Copyright © 2015 IMSS. Published by Elsevier Inc. All rights reserved.

Comparison of Diabetic and Non-diabetic Human Leukocytic Responses to Different Capsule Types of Klebsiella pneumoniae Responsible for Causing Pyogenic Liver Abscess

PubMed Central

Lee, I. Russel; Sng, Ethel; Lee, Kok-Onn; Molton, James S.; Chan, Monica; Kalimuddin, Shirin; Izharuddin, Ezlyn; Lye, David C.; Archuleta, Sophia; Gan, Yunn-Hwen

2017-01-01

The major risk factor for Klebsiella liver abscess (KLA) is type 2 diabetes mellitus (DM), but the immunological mechanisms involved in the increased susceptibility are poorly defined. We investigated the responses of neutrophils and peripheral blood mononuclear cells (PBMCs) to hypervirulent Klebsiella pneumoniae (hvKP), the causative agent of KLA. DNA and myeloperoxidase levels were elevated in the plasma of KLA patients compared to uninfected individuals indicating neutrophil activation, but diabetic status had no effect on these neutrophil extracellular trap (NET) biomarkers in both subject groups. Clinical hvKP isolates universally stimulated KLA patient neutrophils to produce NETs ex vivo, regardless of host diabetic status. Ability of representative capsule types (K1, K2, and non-K1/K2 strains) to survive intra- and extra-cellular killing by type 2 DM and healthy neutrophils was subsequently examined. Key findings were: (1) type 2 DM and healthy neutrophils exhibited comparable total, phagocytic, and NETs killing against hvKP, (2) phagocytic and NETs killing were equally effective against hvKP, and (3) hypermucoviscous K1 and K2 strains were more resistant to total, phagocytic, and NETs killing compared to the non-mucoviscous, non-K1/K2 strain. The cytokine response and intracellular killing ability of type 2 DM as well as healthy PBMCs upon encounter with the different capsule types was also examined. Notably, the IL-12–IFNγ axis and its downstream chemokines MIG, IP-10, and RANTES were produced at slightly lower levels by type 2 DM PBMCs than healthy PBMCs in response to representative K1 and non-K1/K2 strains. Furthermore, type 2 DM PBMCs have a mild defect in its ability to control hvKP replication relative to healthy PBMCs. In summary, our work demonstrates that type 2 DM does not overtly impact neutrophil intra- and extra-cellular killing of hvKP, but may influence cytokine/chemokine production and intracellular killing by PBMCs. PMID:28936426

Klebsiella capsular type versus site of isolation.

PubMed Central

Riser, E; Noone, P

1981-01-01

More than 1750 clinical isolates of klebsiella were collected over a period of six years from two different hospitals and capsular typed by the fluorescent antibody technique. A correlation was made between type and site of isolation. Many types were found to be associated more frequently with one site, which suggested a predilection of some capsular types for certain sites of infection. The site may also be a factor contributing to the virulence of a particular type. A greater antibiotic resistance was often noted in types isolated from their predominant sites; however, antibiograms were not consistent for a type from a given site. The combination of site specificity, resistance, and another 'virulence factor' may all be involved in the determination of a pathogenic strain. PMID:7251896

Detection of an Ambler class D OXA-48-type β-lactamase in a Klebsiella pneumoniae strain in The Netherlands.

PubMed

Kalpoe, Jayant S; Al Naiemi, Nashwan; Poirel, Laurent; Nordmann, Patrice

2011-05-01

Traditionally, bacteria in The Netherlands have low levels of resistance to antibiotics. This report describes what is believed to be the first carbapenem-resistant Klebsiella pneumoniae producing an OXA-48 type β-lactamase in The Netherlands. The isolate co-produced a CTX-M-15 type β-lactamase and was recovered from a patient who was transferred from a hospital in India to an intensive care unit in The Netherlands. His recovery in The Netherlands was complicated by pneumonia due to the carbapenem-resistant K. pneumoniae to which he eventually succumbed. Pre-emptive screening for carbapenem-resistant Enterobacteriaceae in selected patients could be imperative to maintain the low prevalence of these highly resistant bacteria in Dutch hospitals.

Infectious Risk Assessment of Unsafe Handling Practices and Management of Clinical Solid Waste

PubMed Central

Hossain, Md. Sohrab; Rahman, Nik Norulaini Nik Ab; Balakrishnan, Venugopal; Puvanesuaran, Vignesh R.; Sarker, Md. Zaidul Islam; Kadir, Mohd Omar Ab

2013-01-01

The present study was undertaken to determine the bacterial agents present in various clinical solid wastes, general waste and clinical sharp waste. The waste was collected from different wards/units in a healthcare facility in Penang Island, Malaysia. The presence of bacterial agents in clinical and general waste was determined using the conventional bacteria identification methods. Several pathogenic bacteria including opportunistic bacterial agent such as Pseudomonas aeruginosa, Salmonella spp., Klebsiella pneumoniae, Serratia marcescens, Acinetobacter baumannii, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Streptococcus pyogenes were detected in clinical solid wastes. The presence of specific pathogenic bacterial strains in clinical sharp waste was determined using 16s rDNA analysis. In this study, several nosocomial pathogenic bacteria strains of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Lysinibacillus sphaericus, Serratia marcescens, and Staphylococcus aureus were detected in clinical sharp waste. The present study suggests that waste generated from healthcare facilities should be sterilized at the point of generation in order to eliminate nosocomial infections from the general waste or either of the clinical wastes. PMID:23435587

Development of a Colloidal Gold-Based Immunochromatographic Strip for Rapid Detection of Klebsiella pneumoniae Serotypes K1 and K2.

PubMed

Siu, L Kristopher; Tsai, Yu-Kuo; Lin, Jung-Chung; Chen, Te-Li; Fung, Chang-Phone; Chang, Feng-Yee

2016-12-01

In this study, a novel colloidal gold-based immunochromatographic strip (ICS) containing anti-Klebsiella pneumoniae capsular polysaccharide polyclonal antibodies was developed to specifically detect K. pneumoniae serotypes K1 and K2. Capsular polysaccharide K1 and K2 antigens were first used to produce polyclonal anti-K1 and anti-K2 antibodies. Reference strains with different serotypes, nontypeable K. pneumoniae strains, and other bacterial species were then used to assess the sensitivity and specificity of these test strips. The detection limit was found to be 10 5 CFU, and the ICSs were stable for 6 months when stored at room temperature. No false-positive or false-negative results were observed, and equivalent results were obtained compared to those of more conventional test methods, such as PCR or serum agglutination. In conclusion, the ICS developed here requires no technical expertise and allows for the specific, rapid, and simultaneous detection of K. pneumoniae serotypes K1 and K2. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Klebsiella pneumoniae necrotizing fasciitis of the leg in an elderly French woman.

PubMed

Monié, Marguerite; Drieux, Laurence; Nzili, Bernadette; Dicko, Michèle; Goursot, Catherine; Greffard, Sandrine; Decré, Dominique; Mézière, Anthony

2014-01-01

Klebsiella pneumoniae necrotizing fasciitis is a rare infection in regions outside of Asia. Here, we present a case of necrotizing fasciitis of the leg caused by K. pneumoniae in a 92-year-old French woman hospitalized in a geriatric rehabilitation unit. The patient initially presented with dermohypodermitis of the leg that developed from a dirty wound following a fall. A few hours later, this painful injury extended to the entire lower limb, with purplish discoloration of the skin, bullae, and necrosis. Septic shock rapidly appeared and the patient died 9 hours after the onset of symptoms. The patient was Caucasian, with no history of travel to Asia or any underlying disease. Computed tomography revealed no infectious metastatic loci. Blood cultures showed growth of capsular serotype K2 K. pneumoniae strains with virulence factors RmpA, yersiniabactin and aerobactin. This rare and fatal case of necrotizing fasciitis caused by a virulent strain of K. pneumoniae occurred in a hospitalized elderly woman without risk factors. Clinicians and geriatricians in particular should be aware of this important albeit unusual differential diagnosis.

Hypervirulent (hypermucoviscous) Klebsiella pneumoniae

PubMed Central

Shon, Alyssa S.; Bajwa, Rajinder P.S.; Russo, Thomas A.

2013-01-01

A new hypervirulent (hypermucoviscous) variant of Klebsiella pneumoniae has emerged. First described in the Asian Pacific Rim, it now increasingly recognized in Western countries. Defining clinical features are the ability to cause serious, life-threatening community-acquired infection in younger healthy hosts, including liver abscess, pneumonia, meningitis and endophthalmitis and the ability to metastatically spread, an unusual feature for enteric Gram-negative bacilli in the non-immunocompromised. Despite infecting a healthier population, significant morbidity and mortality occurs. Although epidemiologic features are still being defined, colonization, particularly intestinal colonization, appears to be a critical step leading to infection. However the route of entry remains unclear. The majority of cases described to date are in Asians, raising the issue of a genetic predisposition vs. geospecific strain acquisition. The traits that enhance its virulence when compared with “classical” K. pneumoniae are the ability to more efficiently acquire iron and perhaps an increase in capsule production, which confers the hypermucoviscous phenotype. An objective diagnostic test suitable for routine use in the clinical microbiology laboratory is needed. If/when these strains become increasingly resistant to antimicrobials, we will be faced with a frightening clinical scenario. PMID:23302790

An Insight into Antibiotic Resistance to Bacterial Infection in Chronic Liver Disease.

PubMed

Jain, Mayank; Varghese, Joy; Michael, Tom; Kedarishetty, Chandan Kumar; G, Balajee; Swaminathan, Subramanian; Venkataraman, Jayanthi

2017-12-01

End stage liver disease leads to immune dysfunction which predisposes to infection. There has been a rise in antibiotic resistant infections in these patients. There is scanty data f from India or idea regarding the same. The present study was undertaken to determine the type of infection acquired and the prevalence of antibiotic resistant infections in cirrhotic patients at a tertiary referral center in South India. In this retrospective study, all consecutive cirrhotic patients hospitalized between 2011 and 2013 with a microbiologically-documented infection were enrolled. Details of previous admission and antibiotics if received were noted. In culture positive infections, the source of infection (ascites, skin, respiratory tract: sputum/endotracheal tube aspirate, pleural fluid; urine and blood) and microorganisms isolated and their antibiotic susceptibility was noted. A total of 92 patients had 240 culture positive samples in the study period. Majority were Klebseilla followed by Escherichia coli and Enterococcus in nosocomial and health care associated infections. However, Enteroccocus was followed by E. coli and Klebsiella in community acquired infections. The antibiotic sensitivity pattern was analyzed for the major causative organisms such as E. coli , Klebsiella and Enterococcus . Most common resistant strains were extended spectrum beta lactamase producing enterobacteriacae (ESBL) followed by carbapenemase producing Klebsiella and methicillin resistant Staphylococcus aureus . Noscomial infection is the most common type, with Klebsiella and E. coli and there is significant rise in ESBL producing organism.

Mutant Prevention Concentrations of Four Carbapenems against Gram-Negative Rods▿ †

PubMed Central

Credito, Kim; Kosowska-Shick, Klaudia; Appelbaum, Peter C.

2010-01-01

We tested the propensities of four carbapenems to select for resistant Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii mutants by determining the mutant prevention concentrations (MPCs) for 100 clinical strains with various ß-lactam phenotypes. Among the members of the Enterobacteriaceae family and A. baumannii strains, the MPC/MIC ratios were mostly 2 to 4. In contrast, for P. aeruginosa the MPC/MIC ratios were 4 to ≥16. The MPC/MIC ratios for β-lactamase-positive K. pneumoniae and E. coli isolates were much higher (range, 4 to >16 μg/ml) than those for ß-lactamase-negative strains. PMID:20308376

Potential antibacterial activity of some Saudi Arabia honey

PubMed Central

Hegazi, Ahmed G.; Guthami, Faiz M. Al; Gethami, Ahmed F. M. Al; Allah, Fyrouz M. Abd; Saleh, Ashraf A.; Fouad, Ehab A.

2017-01-01

Aim: The aim of this study was to investigate the potential antibacterial activity of some Saudi Arabia honey against selected bacterial strains of medical importance. Materials and Methods: A total of 10 Saudi Arabia honey used to evaluate their antimicrobial activity against some antibiotic-resistant pathogenic bacterial strains. The bacterial strains were Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa. Results: The antibacterial activity of Saudi honey against five bacterial strains showed different levels of inhibition according to the type of honey. The overall results showed that the potential activity was differing according to the pathogen and honey type. Conclusion: It could be concluded that the Saudi honey inhibit the growth of bacterial strains and that honey can be used as complementary antimicrobial agent against selected pathogenic bacteria. PMID:28344408

Inactivation of dhaD and dhaK abolishes by-product accumulation during 1,3-propanediol production in Klebsiella pneumoniae.

PubMed

Horng, Yu-Tze; Chang, Kai-Chih; Chou, Ta-Chung; Yu, Chung-Jen; Chien, Chih-Ching; Wei, Yu-Hong; Soo, Po-Chi

2010-07-01

1,3-Propanediol (1,3-PD) can be used for the industrial synthesis of a variety of compounds, including polyesters, polyethers, and polyurethanes. 1,3-PD is generated from petrochemical and microbial sources. 1,3-Propanediol is a typical product of glycerol fermentation, while acetate, lactate, 2,3-butanediol, and ethanol also accumulate during the process. Substrate and product inhibition limit the final concentration of 1,3-propanediol in the fermentation broth. It is impossible to increase the yield of 1,3-propanediol by using the traditional whole-cell fermentation process. In this study, dhaD and dhaK, the genes for glycerol dehydrogenase and dihydroxyacetone kinase, respectively, were inactivated by homologous recombination in Klebsiella pneumoniae. The dhaD/dhaK double mutant (designated TC100), selected from 5,000 single or double cross homologous recombination mutants, was confirmed as a double cross by using polymerase chain reaction. Analysis of the cell-free supernatant with high-performance liquid chromatography revealed elimination of lactate and 2,3-butanediol, as well as ethanol accumulation in TC100, compared with the wild-type strain. Furthermore, 1,3-propanediol productivity was increased in the TC100 strain expressing glycerol dehydratase and 1,3-PDO dehydrogenase regulated by the arabinose P(BAD) promoter. The genetic engineering and medium formulation approaches used here should aid in the separation of 1,3-propanediol from lactate, 2,3-butanediol, and ethanol and lead to increased production of 1,3-propanediol in Klebsiella pneumoniae.

Survival of bacteria of laboratory animal origin on cage bedding and inactivation by hydrogen peroxide vapour.

PubMed

Benga, Laurentiu; Benten, W Peter M; Engelhardt, Eva; Gougoula, Christina; Schulze-Röbbecke, Roland; Sager, Martin

2017-08-01

This study aims to determine the ability of laboratory animal bacteria to resist desiccation and inactivation by hydrogen peroxide vapour (HPV) on paper bedding pieces. Bedding pieces were saturated with bacterial suspensions in water or 2% (w/v) bovine serum albumin (BSA) in water, and held in a mouse facility. Viable counts showed variable survival rates over time for the bacterial species used ([ Pasteurella] pneumotropica, Muribacter muris, Pseudomonas aeruginosa, Acinetobacter redioresistens, Escherichia coli, Klebsiella oxytoca, Bordetella bronchiseptica, Bordetella hinzii, Enterococcus faecalis, β-haemolytic Streptococcus spp., Staphylococcus aureus and Staphylococcus xylosus). Overall, BSA increased bacterial survival in the bedding pieces. The survival rates of Bacillus safensis were not influenced by BSA but depended on sporulation. When bedding pieces and Petri dishes inoculated with E. coli, P. aeruginosa and S. aureus were subjected to HPV disinfection, all bacterial species on the bedding pieces inoculated with bacterial suspensions in water were readily inactivated. By contrast, S. aureus and P. aeruginosa, but not E. coli cells survived HPV treatment in high numbers when inoculated on bedding pieces as a BSA suspension. Notably, all three bacterial species were readily inactivated by HPV even in the presence of BSA when smeared on smooth surfaces. In conclusion, the suspension medium and the carrier can influence the environmental survival and susceptibility of bacterial species to HPV. Our results may help to develop standard protocols that can be used to ensure the microbiological quality of experimental rodent housing.

Role of Electroosmosis in the Permeation of Neutral Molecules: CymA and Cyclodextrin as an Example

PubMed Central

Bhamidimarri, Satya Prathyusha; Prajapati, Jigneshkumar Dahyabhai; van den Berg, Bert; Winterhalter, Mathias; Kleinekathöfer, Ulrich

2016-01-01

To quantify the flow of small uncharged molecules into and across nanopores, one often uses ion currents. The respective ion-current fluctuations caused by the presence of the analyte make it possible to draw some conclusions about the direction and magnitude of the analyte flow. However, often this flow appears to be asymmetric with respect to the applied voltage. As a possible reason for this asymmetry, we identified the electroosmotic flow (EOF), which is the water transport associated with ions driven by the external transmembrane voltage. As an example, we quantify the contribution of the EOF through a nanopore by investigating the permeation of α-cyclodextrin through CymA, a cyclodextrin-specific channel from Klebsiella oxytoca. To understand the results from electrophysiology on a molecular level, all-atom molecular dynamics simulations are used to detail the effect of the EOF on substrate entry to and exit from a CymA channel in which the N-terminus has been deleted. The combined experimental and computational results strongly suggest that one needs to account for the significant contribution of the EOF when analyzing the penetration of cyclodextrins through the CymA pore. This example study at the same time points to the more general finding that the EOF needs to be considered in translocation studies of neutral molecules and, at least in many cases, should be able to help in discriminating between translocation and binding events. PMID:26840725

Evaluation of microbial contamination associated with different preparation methods for neonatal intravenous fat emulsion infusion.

PubMed

Crill, Catherine M; Hak, Emily B; Robinson, Lawrence A; Helms, Richard A

2010-06-01

Microbial contamination associated with different methods of neonatal intravenous fat emulsion (IVFE) preparation and delivery was evaluated. Sterility testing was performed on IVFE dispensed via three different methods: (1) in the original container (n = 60), (2) repackaged into a syringe (n = 90), and (3) drawdown of the original container (n = 60). At the end of each infusion (24 hours for methods 1 and 3, 12 hours for method 2), a sample of the IVFE was withdrawn from the container using a sterile syringe in an International Organization for Standardization class 5 hood and sent to the hospital microbiology laboratory, where the samples were introduced into blood culture bottles and incubated for five days. Each sample was then subcultured on a blood agar plate with olive oil and left for an additional two days in a carbon dioxide incubator to assess for Malassezia furfur. None of the samples from the original containers showed bacterial or fungal growth. Three of the samples from syringes had bacterial growth (two samples contained coagulase-negative staphylococcus and one contained both Klebsiella oxytoca and Citrobacter freundii), yielding a contamination rate of 3.3%. The number of contaminated samples did not significantly differ among the three preparation methods (p = 0.13). Repackaging IVFE into sterile syringes resulted in bacterial contamination and should be avoided in clinical practice. IVFE samples obtained using the drawdown procedure under sterile conditions for infusion over 24 hours revealed no microbial contamination.

Maggot excretions inhibit biofilm formation on biomaterials.

PubMed

Cazander, Gwendolyn; van de Veerdonk, Mariëlle C; Vandenbroucke-Grauls, Christina M J E; Schreurs, Marco W J; Jukema, Gerrolt N

2010-10-01

Biofilm-associated infections in trauma surgery are difficult to treat with conventional therapies. Therefore, it is important to develop new treatment modalities. Maggots in captured bags, which are permeable for larval excretions/secretions, aid in healing severe, infected wounds, suspect for biofilm formation. Therefore we presumed maggot excretions/secretions would reduce biofilm formation. We studied biofilm formation of Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella oxytoca, Enterococcus faecalis, and Enterobacter cloacae on polyethylene, titanium, and stainless steel. We compared the quantities of biofilm formation between the bacterial species on the various biomaterials and the quantity of biofilm formation after various incubation times. Maggot excretions/secretions were added to existing biofilms to examine their effect. Comb-like models of the biomaterials, made to fit in a 96-well microtiter plate, were incubated with bacterial suspension. The formed biofilms were stained in crystal violet, which was eluted in ethanol. The optical density (at 595 nm) of the eluate was determined to quantify biofilm formation. Maggot excretions/secretions were pipetted in different concentrations to (nonstained) 7-day-old biofilms, incubated 24 hours, and finally measured. The strongest biofilms were formed by S. aureus and S. epidermidis on polyethylene and the weakest on titanium. The highest quantity of biofilm formation was reached within 7 days for both bacteria. The presence of excretions/secretions reduced biofilm formation on all biomaterials. A maximum of 92% of biofilm reduction was measured. Our observations suggest maggot excretions/secretions decrease biofilm formation and could provide a new treatment for biofilm formation on infected biomaterials.

Role of Electroosmosis in the Permeation of Neutral Molecules: CymA and Cyclodextrin as an Example.

PubMed

Bhamidimarri, Satya Prathyusha; Prajapati, Jigneshkumar Dahyabhai; van den Berg, Bert; Winterhalter, Mathias; Kleinekathöfer, Ulrich

2016-02-02

To quantify the flow of small uncharged molecules into and across nanopores, one often uses ion currents. The respective ion-current fluctuations caused by the presence of the analyte make it possible to draw some conclusions about the direction and magnitude of the analyte flow. However, often this flow appears to be asymmetric with respect to the applied voltage. As a possible reason for this asymmetry, we identified the electroosmotic flow (EOF), which is the water transport associated with ions driven by the external transmembrane voltage. As an example, we quantify the contribution of the EOF through a nanopore by investigating the permeation of α-cyclodextrin through CymA, a cyclodextrin-specific channel from Klebsiella oxytoca. To understand the results from electrophysiology on a molecular level, all-atom molecular dynamics simulations are used to detail the effect of the EOF on substrate entry to and exit from a CymA channel in which the N-terminus has been deleted. The combined experimental and computational results strongly suggest that one needs to account for the significant contribution of the EOF when analyzing the penetration of cyclodextrins through the CymA pore. This example study at the same time points to the more general finding that the EOF needs to be considered in translocation studies of neutral molecules and, at least in many cases, should be able to help in discriminating between translocation and binding events. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Bioactive endophytic fungi isolated from Caesalpinia echinata Lam. (Brazilwood) and identification of beauvericin as a trypanocidal metabolite from Fusarium sp.

PubMed

Campos, Fernanda Fraga; Sales Junior, Policarpo A; Romanha, Alvaro José; Araújo, Márcio S S; Siqueira, Ezequias P; Resende, Jarbas M; Alves, Tânia M A; Martins-Filho, Olindo A; Santos, Vera Lúcia dos; Rosa, Carlos A; Zani, Carlos L; Cota, Betania Barros

2015-02-01

Aiming to identify new sources of bioactive secondary metabolites, we isolated 82 endophytic fungi from stems and barks of the native Brazilian tree Caesalpinia echinata Lam. (Fabaceae). We tested their ethyl acetate extracts in several in vitro assays. The organic extracts from three isolates showed antibacterial activity against Staphylococcus aureus and Escherichia coli [minimal inhibitory concentration (MIC) 32-64 μg/mL]. One isolate inhibited the growth of Salmonella typhimurium (MIC 64 μg/mL) and two isolates inhibited the growth of Klebsiella oxytoca (MIC 64 μg/mL), Candida albicans and Candida tropicalis (MIC 64-128 μg/mL). Fourteen extracts at a concentration of 20 μg/mL showed antitumour activities against human breast cancer and human renal cancer cells, while two isolates showed anti-tumour activities against human melanoma cancer cells. Six extracts were able to reduce the proliferation of human peripheral blood mononuclear cells, indicating some degree of selective toxicity. Four isolates were able to inhibit Leishmania (Leishmania) amazonensis and one isolate inhibited Trypanosoma cruzi by at least 40% at 20 μg/mL. The trypanocidal extract obtained from Fusarium sp. [KF611679] culture was subjected to bioguided fractionation, which revealed beauvericin as the compound responsible for the observed toxicity of Fusarium sp. to T. cruzi. This depsipeptide showed a half maximal inhibitory concentration of 1.9 μg/mL (2.43 μM) in a T. cruzi cellular culture assay.

Antibacterial Activity of Ethyl Acetate the Extract of Noni Fruit (Morinda citrifolia L.) Against Bacterial Spoilage in Fish

NASA Astrophysics Data System (ADS)

Nugraheni, E. R.; Adriani, G. R.; Munawaroh, H.

2017-04-01

Noni fruit (Morinda citrifolia L.) contains compounds that have potential as antibacterial agent. Antibacterial compounds produced noni fruit (M. citrifolia L.) can inhibit bacterial growth. This study was conducted to test the antibacterial activity of ethyl acetate extract of noni fruit (M. citrifolia L.) against spoilage bacterial in fish. Pseudomonas aeruginosa, Bacillus cereus, Escherichia coli, Klebsiella oxytoca, and Enterobacter aerogenes isolates and examine antibacterial phytochemical profile. Extraction of noni compounds was done by maceration, followed by partition with ethyl acetate to obtain the soluble and insoluble ethyl acetate fraction. Previews result show that the ethyl acetate extract had very strong activity. Extraction process continued by separation and isolation used preparative thin layer chromatography method, so that obtained five isolates and mark them as A, B, C, D and E. Antibacterial activity assay performed on isolates A, B, C, D, and E with 20 and 30% concentration. The test results showed that isolates A could not be inhibit the growth of bacteria, isolates B, C, D, and E has antibacterial activity with weak to strong inhibition. Isolate B had the greatest inhibition activity against the B. cereus, whereas isolates E had the greatest inhibition activity against P. aeroginosa. MIC (Minimum Inhibitor Concentration) and MBC (Minimum Bactericidal Concentration) test result showed that MIC and MBC values could not be determined. Analysis of compounds by TLC showed that isolate B suspected contains coumarin or flavonoids compounds that have antibacterial activity.

Molecular characteristics of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae causing intra-abdominal infections from 9 tertiary hospitals in China.

PubMed

Liao, Kang; Chen, Yili; Wang, Menghe; Guo, Penghao; Yang, Qiwen; Ni, Yuxing; Yu, Yunsong; Hu, Bijie; Sun, Ziyong; Huang, Wenxiang; Wang, Yong; Wu, Anhua; Feng, Xianju; Luo, Yanping; Hu, Zhidong; Chu, Yunzhuo; Chen, Shulan; Cao, Bin; Su, Jianrong; Gui, Bingdong; Duan, Qiong; Zhang, Shufang; Shao, Haifeng; Kong, Haishen; Xu, Yingchun

2017-01-01

Recently, the emergence of multidrug-resistant organisms such as extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae has raised considerable concern regarding the appropriate treatment of intra-abdominal infections (IAIs). In this study, we investigated the molecular characteristics of ESBL among clinical isolates of Escherichia coli and Klebsiella pneumoniae causing IAIs and their pattern of antimicrobial resistance, which can provide useful information about the epidemiology and risk factors associated with these infections. One hundred sixty-seven E.coli and 47 K. pneumoniae ESBL-producing strains causing IAIs were collected from 9 hospitals in China, during 2012 and 2013. The antimicrobial susceptibility profile of these strains was determined. Polymerase chain reaction and sequencing were performed to identify genes for β-lactamase (blaTEM, blaSHV, blaOXA-1-like, and blaCTX-M). The isolates were also analyzed by pulsed-field gel electrophoresis (PFGE). In 167 ESBL-producing E. coli strains, 104 strains (62.3%) were positive for CTX-M, and 9 strains (5.39%) were positive for SHV. Among the 47 K. pneumoniae strains, 35 strains (74.5%) were positive for SHV-2a, 12 strains (25.5%) were positive for CTX-M. No TEM-type and OXA-1-like strain was detected among all the ESBL-producing strains. Regarding the CTX-M-positive E. coli and K. pneumoniae strains, CTX-M-15 was the most common genotype in E. coli and K. pneumoniae strains, accounting for 28.7% and 17.0%, respectively, followed by CTX-M-55 accounting for 16.2% and 2.13%, respectively; the remaining genotypes included CTX-M-123 and CTX-M-82. PFGE showed that E.coli and K. pneumoniae ESBL-producing strains causing IAIs were diverse and that emerging resistance may not be due to the dissemination of national clones. The present study revealed that in ESBL-producing strains causing IAIs in China, the most common genotype for E.coli was CTX-M-15 and for K. pneumoniae was SHV-2a. However, there was a wide diversity of strains causing IAIs among the ESBL-producing E. coli and K. pneumoniae. Copyright © 2016 Elsevier Inc. All rights reserved.

Probiotic potential of lactobacillus strains isolated from sorghum-based traditional fermented food.

PubMed

Rao, K Poornachandra; Chennappa, G; Suraj, U; Nagaraja, H; Raj, A P Charith; Sreenivasa, M Y

2015-06-01

Sorghum-based traditional fermented food was screened for potential probiotic lactic acid bacteria. The isolates were identified by biochemical, physiological and genetic methods. Species identification was done by 16s rRNA sequence analysis. The functional probiotic potential of the two Lactobacillus species viz., Lactobacillus plantarum (Lact. plantarum) and Lactobacillus pentosus (Lact. pentosus) was assessed by different standard parameters. The strains were tolerant to pH 2 for 1 h and resistant to methicillin, kanamycin, vancomycin and norfloxacin. Two (Lact. plantarum COORG-3 and Lact. pentosus COORG-8) out of eight isolates recorded the cell surface hydrophobicity to be 59.12 and 64.06%, respectively. All the strains showed tolerance to artificial duodenum juice (pH 2) for 3 h, positive for bile salt hydrolase test and negative for haemolytic test. The neutralized cell-free supernatant of the strains Lact. pentosus COORG-4, Lact. plantarum COORG-1, Lact. plantarum COORG-7, Lact. pentosus COORG-8 and Lact. plantarum COORG-3 showed good antibiofilm activity. Lact. pentosus COORG-8 exhibited 74% activity against Pseudomonas aeruginosa-MTCC 7903 and Lact. plantarum COORG-7 showed 68% inhibition of biofilm against Klebsiella pneumonia MTCC 7407. Three (Lact. plantarum COORG-7, Lact. pentosus COORG-5 and Lact. pentosus COORG 8) out of eight isolates exhibited a good antimicrobial activity against Listeria monocytogenes and five isolates (Lact. pentosus COORG 2, Lact. plantarum COORG 1, Lact. plantarum COORG 4, Lact. pentosus COORG 3 and Lact. plantarum COORG 6) are active against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Enterobacter aerogenes, Klebsiella pneumonia, Enterococcus faecalis. The study also evaluated the cholesterol lowering property of the Lactobacillus strains using hen egg yolk as the cholesterol source. The cholesterol in hen egg yolk was assimilated by 74.12 and 68.26% by Lact. plantarum COORG 4 and Lact. pentosus COORG 7, respectively. The results of the present study suggest that the Lactobacillus strains isolated and characterized from sorghum-based fermented product may be used as probiotic strains for therapeutic applications.

Pharmacodynamics of moxifloxacin and levofloxacin against Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli: simulation of human plasma concentrations after intravenous dosage in an in vitro kinetic model.

PubMed

Odenholt, Inga; Cars, Otto

2006-11-01

To compare in an in vitro kinetic model the pharmacodynamics of moxifloxacin and levofloxacin with a concentration-time profile simulating the human free non-protein bound concentrations of 400 mg moxifloxacin intravenous (iv) once daily, 500 mg levofloxacin iv once daily and 750 mg levofloxacin iv once daily against strains of Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli with variable susceptibility to fluoroquinolones. The strains used in the study included S. pneumoniae ATCC 6306 (native strain), S. pneumoniae 19397 (double mutation; gyrA and parC), S. pneumoniae 4241 (single mutation; parC), S. aureus ATCC 13709 (native strain), S. aureus MB5 (single mutation; gyrA), E. coli M12 (single mutation; gyrA), E. coli ATCC 25922 (native strain) and K. pneumoniae ATCC 29655 (native strain). The strains were exposed to moxifloxacin and levofloxacin in an in vitro kinetic model simulating the free human serum concentration-time profile of moxifloxacin 400 mg once daily, levofloxacin 500 mg once daily and 750 mg once daily. Repeated samples were taken regularly during 24 h and viable counts were carried out. A correlation was seen between both the area under the serum concentration curve and MIC (AUC/MIC) and the peak concentration/MIC (Cmax/MIC) versus area under the bactericidal killing curve (AUBKC) or Deltalog0-24 cfu/mL. Compiling all data, an AUC/MIC of approximately 100 and a Cmax/MIC of 10 gave a maximal bactericidal effect for both levofloxacin and moxifloxacin. In accordance with the results from others, our study indicated that a lower AUC/MIC was needed for S. pneumoniae in comparison with the Gram-negative bacteria studied. Moxifloxacin yielded higher AUC/MIC and Cmax/MIC against the investigated Gram-positive bacteria in comparison with levofloxacin 500 mg once daily and 750 mg once daily.

Imipenem resistance in Klebsiella pneumoniae is associated with the combination of ACT-1, a plasmid-mediated AmpC beta-lactamase, and the foss of an outer membrane protein.

PubMed Central

Bradford, P A; Urban, C; Mariano, N; Projan, S J; Rahal, J J; Bush, K

1997-01-01

Six Escherichia coli and 12 Klebsiella pneumoniae isolates from a single hospital expressed a common beta-lactamase with a pI of approximately 9.0 and were resistant to cefoxitin and cefotetan (MIC ranges, 64 to > 128 and 16 to > 128 micrograms/ml, respectively). Seventeen of the 18 strains produced multiple beta-lactamases. Most significantly, three K. pneumoniae strains were also resistant to imipenem (MICs, 8 to 32 micrograms/ml). Spectrophotometric beta-lactamase assays with purified enzyme indicated hydrolysis of cephamycins, in addition to cephaloridine and benzylpenicillin. The 4ene encoding the pI 9.0 beta-lactamase (designated ACT-1 for AmpC type) was cloned and sequenced, which revealed an ampC-type beta-lactamase gene that originated from Enterobacter cloacae and that had 86% sequence homology to the P99 beta-lactamase and 94% homology to the partial sequence of MIR-1. Southern blotting revealed that the gene encoding ACT-1 was on a large plasmid in some of the K. pneumoniae strains as well as on the chromosomes of all of the strains, suggesting that the gene is located on an easily mobilized element. Outer membrane protein profiles of the K. pneumoniae strains revealed that the three imipenem-resistant strains were lacking a major outer membrane protein of approximately 42 kDa which was present in the imipenem-susceptible strains. ACT-1 is the first plasmid-mediated AmpC-type beta-lactamase derived from Enterobacter which has been completely sequenced. This work demonstrates that in addition to resistance to cephamycins, imipenem resistance can occur in K. pneumoniae when a high level of the ACT-1 beta-lactamase is produced in combination with the loss of a major outer membrane protein. PMID:9055993

Mechanisms of Increased Resistance to Chlorhexidine and Cross-Resistance to Colistin following Exposure of Klebsiella pneumoniae Clinical Isolates to Chlorhexidine

PubMed Central

Bock, Lucy J.; Bonney, Laura C.

2016-01-01

ABSTRACT Klebsiella pneumoniae is an opportunistic pathogen that is often difficult to treat due to its multidrug resistance (MDR). We have previously shown that K. pneumoniae strains are able to “adapt” (become more resistant) to the widely used bisbiguanide antiseptic chlorhexidine. Here, we investigated the mechanisms responsible for and the phenotypic consequences of chlorhexidine adaptation, with particular reference to antibiotic cross-resistance. In five of six strains, adaptation to chlorhexidine also led to resistance to the last-resort antibiotic colistin. Here, we show that chlorhexidine adaptation is associated with mutations in the two-component regulator phoPQ and a putative Tet repressor gene (smvR) adjacent to the major facilitator superfamily (MFS) efflux pump gene, smvA. Upregulation of smvA (10- to 27-fold) was confirmed in smvR mutant strains, and this effect and the associated phenotype were suppressed when a wild-type copy of smvR was introduced on plasmid pACYC. Upregulation of phoPQ (5- to 15-fold) and phoPQ-regulated genes, pmrD (6- to 19-fold) and pmrK (18- to 64-fold), was confirmed in phoPQ mutant strains. In contrast, adaptation of K. pneumoniae to colistin did not result in increased chlorhexidine resistance despite the presence of mutations in phoQ and elevated phoPQ, pmrD, and pmrK transcript levels. Insertion of a plasmid containing phoPQ from chlorhexidine-adapted strains into wild-type K. pneumoniae resulted in elevated expression levels of phoPQ, pmrD, and pmrK and increased resistance to colistin, but not chlorhexidine. The potential risk of colistin resistance emerging in K. pneumoniae as a consequence of exposure to chlorhexidine has important clinical implications for infection prevention procedures. PMID:27799211

Severe sepsis facilitates intestinal colonization by extended-spectrum-β-lactamase-producing Klebsiella pneumoniae and transfer of the SHV-18 resistance gene to Escherichia coli during antimicrobial treatment.

PubMed

Guan, Jun; Liu, Shaoze; Lin, Zhaofen; Li, Wenfang; Liu, Xuefeng; Chen, Dechang

2014-01-01

Infections caused by multidrug-resistant pathogens are frequent and life threatening in critically ill patients. To investigate whether severe sepsis affects gut colonization by resistant pathogens and genetic exchange between opportunistic pathogens, we tested the intestinal-colonization ability of an extended-spectrum beta-lactamase-producing Klebsiella pneumoniae strain carrying the SHV-18 resistance gene and the transfer ability of the resistance gene to endogenous Escherichia coli under ceftriaxone treatment in rats with burn injury only or severe sepsis induced by burns plus endotoxin exposure. Without ceftriaxone treatment, the K. pneumoniae strain colonized the intestine in both septic and burned rats for a short time, with clearance occurring earlier in burn-only rats but never in sham burn rats. In both burned and septic rats, the colonization level of the challenge strain dropped at the beginning and then later increased during ceftriaxone treatment, after which it declined gradually. This pattern coincided with the change in resistance of K. pneumoniae to ceftriaxone during and after ceftriaxone treatment. Compared with burn-only injury, severe sepsis had a more significant effect on the change in antimicrobial resistance to ceftriaxone. Only in septic rats was the resistance gene successfully transferred from the challenge strain to endogenous E. coli during ceftriaxone treatment; the gene persisted for at least 4 weeks after ceftriaxone treatment. We concluded that severe sepsis can facilitate intestinal colonization by an exogenous resistant pathogen and the transfer of the resistance gene to a potential endogenous pathogen during antimicrobial treatment.

Plasmid Dynamics in KPC-Positive Klebsiella pneumoniae during Long-Term Patient Colonization

PubMed Central

Park, Morgan; Deming, Clayton; Thomas, Pamela J.; Young, Alice C.; Coleman, Holly; Sison, Christina; Weingarten, Rebecca A.; Lau, Anna F.; Dekker, John P.; Palmore, Tara N.; Frank, Karen M.

2016-01-01

ABSTRACT Carbapenem-resistant Klebsiella pneumoniae strains are formidable hospital pathogens that pose a serious threat to patients around the globe due to a rising incidence in health care facilities, high mortality rates associated with infection, and potential to spread antibiotic resistance to other bacterial species, such as Escherichia coli. Over 6 months in 2011, 17 patients at the National Institutes of Health (NIH) Clinical Center became colonized with a highly virulent, transmissible carbapenem-resistant strain of K. pneumoniae. Our real-time genomic sequencing tracked patient-to-patient routes of transmission and informed epidemiologists’ actions to monitor and control this outbreak. Two of these patients remained colonized with carbapenemase-producing organisms for at least 2 to 4 years, providing the opportunity to undertake a focused genomic study of long-term colonization with antibiotic-resistant bacteria. Whole-genome sequencing studies shed light on the underlying complex microbial colonization, including mixed or evolving bacterial populations and gain or loss of plasmids. Isolates from NIH patient 15 showed complex plasmid rearrangements, leaving the chromosome and the blaKPC-carrying plasmid intact but rearranging the two other plasmids of this outbreak strain. NIH patient 16 has shown continuous colonization with blaKPC-positive organisms across multiple time points spanning 2011 to 2015. Genomic studies defined a complex pattern of succession and plasmid transmission across two different K. pneumoniae sequence types and an E. coli isolate. These findings demonstrate the utility of genomic methods for understanding strain succession, genome plasticity, and long-term carriage of antibiotic-resistant organisms. PMID:27353756

First Description of KPC-2-Producing Escherichia coli and ST15 OXA-48-Positive Klebsiella pneumoniae in Tunisia.

PubMed

Ben Tanfous, Farah; Alonso, Carla Andrea; Achour, Wafa; Ruiz-Ripa, Laura; Torres, Carmen; Ben Hassen, Assia

2017-04-01

The aim of this study was to investigate the molecular features among Klebsiella pneumoniae and Escherichia coli strains showing a resistant/intermediate-resistant phenotype to ertapenem (R/IR-ERT), implicated in colonization/infection in patients of the Hematology and Graft Units of the National Bone Marrow Transplant Center of Tunisia (3-year period, 2011-2014). The major carbapenemase, extended-spectrum beta-lactamase, and plasmidic AmpC beta-lactamase genes were analyzed and characterized by PCR and sequencing. Genetic relatedness was determined by pulsed-field gel electrophoresis (PFGE) using XbaI and multilocus sequencing typing. The bla OXA-48 and bla KPC carbapenemase genes were detected among R/IR-ERT isolates. All R/IR-ERT K. pneumoniae strains (n = 19) had bla OXA-48 gene, and 14/19 strains also harbored the bla CTX-M-15 gene. Eight different PFGE patterns were detected among these K. pneumoniae isolates, and they showed eight different sequences types, ST11 and ST15 being the most prevalent ones. Two out of three R/IR-ERT E. coli isolates carried bla OXA-48 and one coproduced the bla CTX-M-15 gene. One E. coli strain, ascribed to the new sequence type ST5700, harbored the bla KPC-2 gene. E. coli isolates were not clonally related and belonged to different sequence types (ST5700, ST227, and ST58). To our knowledge, this is the first report in Tunisia of either KPC-2 carbapenemase in E. coli or OXA-48 carbapenemase in K. pneumoniae of lineage ST15.

Infection Prevention and Control in Deployed Military Medical Treatment Facilities

DTIC Science & Technology

2011-08-01

Targeted intranasal mupi- rocin to prevent colonization and infection by community-associated methicillin - resistant Staphylococcus aureus strains in...Natural history of community-acquired methicillin - resistant Staphylococcus au- reus colonization and infection in soldiers. Clin Infect Dis. 2004;39...coli and Klebsiella pneumoniae), P. aeruginosa, and methicillin - resistant S. au- reus (MRSA), have most commonly been reported as the cause of these

Imipenem represses CRISPR-Cas interference of DNA acquisition through H-NS stimulation in Klebsiella pneumoniae.

PubMed

Lin, Tzu-Lung; Pan, Yi-Jiun; Hsieh, Pei-Fang; Hsu, Chun-Ru; Wu, Meng-Chuan; Wang, Jin-Town

2016-08-17

Analysis of the genome of Klebsiella pneumoniae NTUH-K2044 strain revealed the presence of two clustered regularly interspaced short palindromic repeats (CRISPR) arrays separated with CRISPR-associated (cas) genes. Carbapenem-resistant K. pneumoniae isolates were observed to be less likely to have CRISPR-Cas than sensitive strains (5/85 vs. 22/132). Removal of the transcriptional repressor, H-NS, was shown to prevent the transformation of plasmids carrying a spacer and putative proto-spacer adjacent motif (PAM). The CRISPR-Cas system also decreased pUC-4K plasmid stability, resulting in plasmid loss from the bacteria with acquisition of new spacers. Analysis of the acquired proto-spacers in pUC-4K indicated that 5'-TTN-3' was the preferred PAM in K. pneumoniae. Treatment of cells by imipenem induced hns expression, thereby decreasing cas3 expression and consequently repressed CRISPR-Cas activity resulted in increase of plasmid stability. In conclusion, NTUH-K2044 CRISPR-Cas contributes to decrease of plasmid transformation and stability. Through repression of CRISPR-Cas activity by induced H-NS, bacteria might be more able to acquire DNA to confront the challenge of imipenem.

Biodegradation of thermally treated high-density polyethylene (HDPE) by Klebsiella pneumoniae CH001.

PubMed

Awasthi, Shraddha; Srivastava, Pratap; Singh, Pardeep; Tiwary, D; Mishra, Pradeep Kumar

2017-10-01

Biodegradation of plastics, which are the potential source of environmental pollution, has received a great deal of attention in the recent years. We aim to screen, identify, and characterize a bacterial strain capable of degrading high-density polyethylene (HDPE). In the present study, we studied HDPE biodegradation using a laboratory isolate, which was identified as Klebsiella pneumoniae CH001 (Accession No MF399051). The HDPE film was characterized by Universal Tensile Machine (UTM), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and Atomic Force Microscope (AFM) before and after microbial incubation. We observed that this strain was capable of adhering strongly on HDPE surface and form a thick biofilm, when incubated in nutrient broth at 30 °C on 120 rpm for 60 days. UTM analysis showed a significant decrease in weight (18.4%) and reduction in tensile strength (60%) of HDPE film. Furthermore, SEM analysis showed the cracks on the HDPE surface, whereas AFM results showed an increase in surface roughness after bacterial incubation. Overall, these results indicate that K. pneumoniae CH001 can be used as potential candidate for HDPE degradation in eco-friendly and sustainable manner in the environment.

Biofilms from Klebsiella pneumoniae: Matrix Polysaccharide Structure and Interactions with Antimicrobial Peptides.

PubMed

Benincasa, Monica; Lagatolla, Cristina; Dolzani, Lucilla; Milan, Annalisa; Pacor, Sabrina; Liut, Gianfranco; Tossi, Alessandro; Cescutti, Paola; Rizzo, Roberto

2016-08-10

Biofilm matrices of two Klebsiella pneumoniae clinical isolates, KpTs101 and KpTs113, were investigated for their polysaccharide composition and protective effects against antimicrobial peptides. Both strains were good biofilm producers, with KpTs113 forming flocs with very low adhesive properties to supports. Matrix exopolysaccharides were isolated and their monosaccharide composition and glycosidic linkage types were defined. KpTs101 polysaccharide is neutral and composed only of galactose, in both pyranose and furanose ring configurations. Conversely, KpTs113 polysaccharide is anionic due to glucuronic acid units, and also contains glucose and mannose residues. The susceptibility of the two strains to two bovine cathelicidin antimicrobial peptides, BMAP-27 and Bac7(1-35), was assessed using both planktonic cultures and biofilms. Biofilm matrices exerted a relevant protection against both antimicrobials, which act with quite different mechanisms. Similar protection was also detected when antimicrobial peptides were tested against planktonic bacteria in the presence of the polysaccharides extracted from KpTs101 and KpTs113 biofilms, suggesting sequestering adduct formation with antimicrobials. Circular dichroism experiments on BMAP-27 in the presence of increasing amounts of either polysaccharide confirmed their ability to interact with the peptide and induce an α-helical conformation.

Structural Masquerade of Plesiomonas shigelloides Strain CNCTC 78/89 O-Antigen-High-Resolution Magic Angle Spinning NMR Reveals the Modified d-galactan I of Klebsiella pneumoniae.

PubMed

Ucieklak, Karolina; Koj, Sabina; Pawelczyk, Damian; Niedziela, Tomasz

2017-11-29

The high-resolution magic angle spinning nuclear magnetic resonance spectroscopy (HR-MAS NMR) analysis of Plesiomonas shigelloides 78/89 lipopolysaccharide directly on bacteria revealed the characteristic structural features of the O -acetylated polysaccharide in the NMR spectra. The O -antigen profiles were unique, yet the pattern of signals in the, spectra along with their ¹H, 13 C chemical shift values, resembled these of d-galactan I of Klebsiella pneumoniae . The isolated O- specific polysaccharide (O-PS) of P. shigelloides strain CNCTC 78/89 was investigated by ¹H and 13 C NMR spectroscopy, mass spectrometry and chemical methods. The analyses demonstrated that the P. shigelloides 78/89 O- PS is composed of →3)-α-d-Gal p -(1→3)-β-d-Gal f 2OAc-(1→ disaccharide repeating units. The O- acetylation was incomplete and resulted in a microheterogeneity of the O- antigen. This O- acetylation generates additional antigenic determinants within the O- antigen, forms a new chemotype, and contributes to the epitopes recognized by the O- serotype specific antibodies. The serological cross-reactivities further confirmed the inter-specific structural similarity of these O- antigens.

Imipenem represses CRISPR-Cas interference of DNA acquisition through H-NS stimulation in Klebsiella pneumoniae

PubMed Central

Lin, Tzu-Lung; Pan, Yi-Jiun; Hsieh, Pei-Fang; Hsu, Chun-Ru; Wu, Meng-Chuan; Wang, Jin-Town

2016-01-01

Analysis of the genome of Klebsiella pneumoniae NTUH-K2044 strain revealed the presence of two clustered regularly interspaced short palindromic repeats (CRISPR) arrays separated with CRISPR-associated (cas) genes. Carbapenem-resistant K. pneumoniae isolates were observed to be less likely to have CRISPR-Cas than sensitive strains (5/85 vs. 22/132). Removal of the transcriptional repressor, H-NS, was shown to prevent the transformation of plasmids carrying a spacer and putative proto-spacer adjacent motif (PAM). The CRISPR-Cas system also decreased pUC-4K plasmid stability, resulting in plasmid loss from the bacteria with acquisition of new spacers. Analysis of the acquired proto-spacers in pUC-4K indicated that 5′-TTN-3′ was the preferred PAM in K. pneumoniae. Treatment of cells by imipenem induced hns expression, thereby decreasing cas3 expression and consequently repressed CRISPR-Cas activity resulted in increase of plasmid stability. In conclusion, NTUH-K2044 CRISPR-Cas contributes to decrease of plasmid transformation and stability. Through repression of CRISPR-Cas activity by induced H-NS, bacteria might be more able to acquire DNA to confront the challenge of imipenem. PMID:27531594

Control of a multi-hospital outbreak of KPC-producing Klebsiella pneumoniae type 2 in France, September to October 2009.

PubMed

Carbonne, A; Thiolet, J M; Fournier, S; Fortineau, N; Kassis-Chikhani, N; Boytchev, I; Aggoune, M; Seguier, J C; Senechal, H; Tavolacci, M P; Coignard, B; Astagneau, P; Jarlier, V

2010-12-02

An outbreak of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae type 2 was detected in September 2009 in two hospitals in a suburb south of Paris, France. In total, 13 KPC-producing K. pneumoniae type 2 cases (four with infections and nine with digestive-tract colonisations) were identified, including a source case transferred from a Greek hospital. Of the 13 cases, seven were secondary cases associated with use of a contaminated duodenoscope used to examine the source case (attack rate: 41%) and five were secondary cases associated with patient-to-patient transmission in hospital. All isolated strains from the 13 patients: (i) exhibited resistance to all antibiotics except gentamicin and colistin, (ii) were more resistant to ertapenem (minimum inhibitory concentration (MIC) always greater than 4 mg/L) than to imipenem (MIC: 1–8 mg/L, depending on the isolate), (iii) carried the blaKPC-2 and blaSHV12 genes and (iv) had an indistinguishable pulsed-field gel electrophoresis (PFGE) pattern. These cases occurred in three hospitals: some were transferred to four other hospitals. Extended infection control measures implemented in the seven hospitals included: (i) limiting transfer of cases and contact patients to other wards, (ii) cohorting separately cases and contact patients, (iii) reinforcing hand hygiene and contact precautions and (iv) systematic screening of contact patients. Overall, 341 contact patients were screened. A year after the outbreak, no additional case has been identified in these seven hospitals. This outbreak emphasises the importance of rapid identification and notification of emerging highly resistant K. pneumoniae strains in order to implement reinforced control measures.

Exogenous cytokine modulation or neutralization of interleukin-10 enhance survival in lipopolysaccharide-hyporesponsive C3H/HeJ mice with Klebsiella infection

PubMed Central

Wang, M-J; Jeng, K-C G; Ping, L-I

1999-01-01

Klebsiella pneumoniae has been isolated from liver abscesses in patients with leukaemia or diabetes. The resistance of Klebsiella infection in lipopolysaccharide (LPS)-hyporesponsive mice is unclear. Female C3H/HeJ and C3H/HeN mice, 6–8 weeks old, were intraperitoneally (i.p.) injected with K. pneumoniae. The results showed that C3H/HeJ mice were 24 times more susceptible [lethal dose 50% (LD50) 250 colony-forming units] than C3H/HeN mice to K. pneumoniae infection. C3H/HeJ mice, uninfected or infected with K. pneumoniae, had higher liver interleukin (IL)-10 levels and IL-10 mRNA levels than C3H/HeN mice. Previously, pretreatment with IL-1β and tumour necrosis factor-α (TNF-α) protected C3H/HeJ mice from lethal bacterial infection. Therefore the effects of pretreatment with IL-1β and TNF-α or antimurine IL-10 antibody i.p. 1 hr before this infection in both strains of C3H mice were examined. Pretreatment with TNF-α or anti-IL-10 antibody enhanced the survival of both strains of mice. TNF-α, in combination with IL-1β, enhanced the survival and bacterial clearance better than single pretreatment in C3H/HeJ mice. Anti-IL-10 antibody increased bacterial clearance and significantly reduced liver cytokine mRNA levels in C3H/HeJ mice more than it did in the controls during infection. These results indicate that exogenous cytokine modulation or neutralization of IL-10 enhance the resistance of LD50 infection in C3H/HeJ mice. PMID:10469238

[Evolution of susceptibility to antibiotics of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumanii, in a University Hospital Center of Beirut between 2005 and 2009].

PubMed

Hamouche, E; Sarkis, D K

2012-06-01

Until recently, multiresistant bacteria were only limited to hospitals. However, they are now responsible for community acquired infections, affecting people who have had no contact with the hospital environment. Several mechanisms are associated with these resistances. The production of betalactamases is however the predominant mechanism and especially the production of extended spectrum beta-lactamases or ESBL by strains of Escherichia coli and Klebsiella pneumoniae, which mediate resistance to third generation cephalosporins and aztreonam (AZT). The association of multiple mechanisms of resistance (efflux pumps, impermeability and enzymatic inactivation) generates multi resistant bacteria such as Pseudomonas aeruginosa MDR and Klebsiella pneumoniae MDR. The aim of the study was to analyze retrospectively the susceptibility to antibiotics of strains of E. coli, K. pneumoniae, P. aeruginosa and A. baumanii isolated from hospitalized and outpatients in a university hospital center of Beirut over a period of five years from 2005 to 2009. Bacterial strains were classified according to their origin (inpatients versus outpatients), their ability to produce or not ESBLs for E. coli and K. pneumonia and if they were MDR for P. aeruginosa and A. baumanii. Antibiotics susceptibilities were retrieved from the informatics database of the hospital. Comparison of susceptibility percentages was done using a unilateral z-test on a computer program. In 2009, 2541 strains of E. coli were isolated, 773 of which or 30.4 % were ESBL producers while 2031 strains were isolated in 2005, of which 361 or 17.8 % were ESBL producers (p<0.001). We noticed a decrease in hospital strains susceptibility to ceftazidime (CAZ) and AZT, between 2005 and 2009 (p<0.001), and a decrease in community strains susceptibility to triméthoprime/sulfaméthoxazole (SXT) between 2005 and 2009 (p=0.03). We noted however a significant decrease of ESBL producing strains between 2007 and 2009: 33.4 % versus 30.4 % (p=0.03). Among 560 strains of K. pneumoniae isolated in 2009, 178 strains or 31.8 % were ESBL producers in comparison to 23.7 % of the strains isolated in 2005 (p=0.03). We also noticed a decrease in hospital strains susceptibility to piperacilline-tazobactam (TZP), cefotaxime (CTX) and AZT (p<0.001 p=0.03 and p=0.03 respectively) between 2006 and 2009, and a significant increase in ESBL producing strains between 2008 et 2009 (p=0.0001). 26.5 % of P. aeruginosa strains isolated in 2009 were MDR bacteria with no significant change as compared to 26.6 % in 2005 (p=0.5). However, the percentage of MDR strains slightly decreased between 2008 and 2009 (p=0.047). The susceptibility of MDR strains to CAZ and imipenem (IMP) decreased between 2005 and 2009 (p<0.001 and P=0.003 respectively). As for A. baumanii, 77.7 % of strains were MDR in 2009 in comparison to 73.4 % in 2005 (p=0.24) with a dramatic decrease of MDR strains susceptibility to IMP from 92.3 % in 2006 to 30 % in 2009 (p<0.001). Despite restrictions on antibiotics prescriptions and isolation of patients harboring MDR bacteria or bacteria producing ESBL, there has not been satisfactory reduction of multi resistant bacteria and efforts should be made to reduce these bugs from the hospital flora. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Emergence of Klebsiella variicola positive for NDM-9, a variant of New Delhi metallo-β-lactamase, in an urban river in South Korea.

PubMed

Di, Doris Y W; Jang, Jeonghwan; Unno, Tatsuya; Hur, Hor-Gil

2017-04-01

To examine the presence of pathogenic bacteria carrying New Delhi metallo-β-lactamase in the environment and to characterize the genome structures of these strains. Phenotypic screening of antimicrobial susceptibility and WGS were conducted on three Klebsiella variicola strains possessing NDM-9 isolated from an urban river. Three carbapenem-resistant K. variicola isolated from Gwangju tributary were found to possess bla NDM-9 genes. Antimicrobial susceptibility testing indicated resistance of these strains to aminoglycosides, carbapenems, cephems, folate pathway inhibitors, fosfomycin and penicillins, but susceptibility to fluoroquinolones, phenicols, tetracyclines and miscellaneous agents. WGS revealed that the 108 kb IncFII(Y)-like plasmids carry bla NDM-9 sandwiched between IS 15 for the GJ1 strain, IS 26 for the GJ2 strain, IS 15D1 for the GJ3 strain and IS Vsa3 , and further bracketed by IS 26 and Tn AS3 along with the mercury resistance operon upstream and the class 1 integron composed of gene cassettes of aadA2 , dfrA12 and sul1 downstream. An aph(3')-Ia gene conferring resistance to aminoglycosides is located after the integrons. Chromosomally encoded bla LEN-13 , fosA , aqxA and oqxB genes, as well as plasmid-mediated bla TEM-1B and bla CTX-M-65 encoding ESBL, ant(3')-Ia and mph (A) genes, were also identified. The findings of the present study provide us with the information that NDM-9 has been spreading into the environment. Dissemination of NDM-9 in the environment has raised a health risk alarm as this variant of NDM carries MDR genes with highly transferable mobile genetic elements, increasing the possibility of resistance gene transfer among microorganisms in the environment. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Efficacy of Colistin and Its Combination With Rifampin in Vitro and in Experimental Models of Infection Caused by Carbapenemase-Producing Clinical Isolates of Klebsiella pneumoniae.

PubMed

Pachón-Ibáñez, María E; Labrador-Herrera, Gema; Cebrero-Cangueiro, Tania; Díaz, Caridad; Smani, Younes; Del Palacio, José P; Rodríguez-Baño, Jesús; Pascual, Alvaro; Pachón, Jerónimo; Conejo, M Carmen

2018-01-01

Despite the relevance of carbapenemase-producing Klebsiella pneumoniae (CP-Kp) infections there are a scarce number of studies to evaluate in vivo the efficacy of combinations therapies. The bactericidal activity of colistin, rifampin, and its combination was studied (time-kill curves) against four clonally unrelated clinical isolates of CP-Kp, producing VIM-1, VIM-1 plus DHA-1(acquired AmpC β-lactamase), OXA-48 plus CTX-M-15 (extended spectrum β-lactamase) and KPC-3, respectively, with colistin MICs of 0.5, 64, 0.5, and 32 mg/L, respectively. The efficacies of antimicrobials in monotherapy and in combination were tested in a murine peritoneal sepsis model, against all the CP-Kp. Their efficacies were tested in the pneumonia model against the OXA-48 plus CTX-M-15 producers. The development of colistin-resistance was analyzed for the colistin-susceptible strains in vitro and in vivo . In vitro , colistin plus rifampin was synergistic against all the strains at 24 h. In vivo , compared to the controls, rifampin alone reduced tissue bacterial concentrations against VIM-1 and OXA-48 plus CTX-M-15 strains; CMS plus rifampin reduced tissue bacterial concentrations of these two CP-Kp and of the KPC-3 strain. Rifampin and the combination increased the survival against the KPC-3 strain; in the pneumonia model, the combination also improved the survival. No resistant mutants appeared with the combination. In conclusion, CMS plus rifampin had a low and heterogeneous efficacy in the treatment of severe peritoneal sepsis model due to CP-Kp producing different carbapenemases, increasing survival only against the KPC-3 strain. The combination showed efficacy in the less severe pneumonia model. The combination prevented in vitro and in vivo the development of colistin resistant mutants.

Efficacy of Colistin and Its Combination With Rifampin in Vitro and in Experimental Models of Infection Caused by Carbapenemase-Producing Clinical Isolates of Klebsiella pneumoniae

PubMed Central

Pachón-Ibáñez, María E.; Labrador-Herrera, Gema; Cebrero-Cangueiro, Tania; Díaz, Caridad; Smani, Younes; del Palacio, José P.; Rodríguez-Baño, Jesús; Pascual, Alvaro; Pachón, Jerónimo; Conejo, M. Carmen

2018-01-01

Despite the relevance of carbapenemase-producing Klebsiella pneumoniae (CP-Kp) infections there are a scarce number of studies to evaluate in vivo the efficacy of combinations therapies. The bactericidal activity of colistin, rifampin, and its combination was studied (time–kill curves) against four clonally unrelated clinical isolates of CP-Kp, producing VIM-1, VIM-1 plus DHA-1(acquired AmpC β-lactamase), OXA-48 plus CTX-M-15 (extended spectrum β-lactamase) and KPC-3, respectively, with colistin MICs of 0.5, 64, 0.5, and 32 mg/L, respectively. The efficacies of antimicrobials in monotherapy and in combination were tested in a murine peritoneal sepsis model, against all the CP-Kp. Their efficacies were tested in the pneumonia model against the OXA-48 plus CTX-M-15 producers. The development of colistin-resistance was analyzed for the colistin-susceptible strains in vitro and in vivo. In vitro, colistin plus rifampin was synergistic against all the strains at 24 h. In vivo, compared to the controls, rifampin alone reduced tissue bacterial concentrations against VIM-1 and OXA-48 plus CTX-M-15 strains; CMS plus rifampin reduced tissue bacterial concentrations of these two CP-Kp and of the KPC-3 strain. Rifampin and the combination increased the survival against the KPC-3 strain; in the pneumonia model, the combination also improved the survival. No resistant mutants appeared with the combination. In conclusion, CMS plus rifampin had a low and heterogeneous efficacy in the treatment of severe peritoneal sepsis model due to CP-Kp producing different carbapenemases, increasing survival only against the KPC-3 strain. The combination showed efficacy in the less severe pneumonia model. The combination prevented in vitro and in vivo the development of colistin resistant mutants.

Comparative analysis of Klebsiella pneumoniae strains isolated in 2012-2016 that differ by antibiotic resistance genes and virulence genes profiles.

PubMed

Lev, Anastasia I; Astashkin, Eugeny I; Kislichkina, Angelina A; Solovieva, Ekaterina V; Kombarova, Tatiana I; Korobova, Olga V; Ershova, Olga N; Alexandrova, Irina A; Malikov, Vladimir E; Bogun, Alexander G; Borzilov, Alexander I; Volozhantsev, Nikolay V; Svetoch, Edward A; Fursova, Nadezhda K

2018-04-30

The antibacterial resistance and virulence genotypes and phenotypes of 148 non-duplicate Klebsiella pneumoniae strains collected from 112 patients in Moscow hospitals in 2012-2016 including isolates from the respiratory system (57%), urine (30%), wounds (5%), cerebrospinal fluid (4%), blood (3%), and rectal swab (1%) were determined. The majority (98%) were multidrug resistant (MDR) strains carrying bla SHV (91%), bla CTX-M (74%), bla TEM (51%), bla OXA (38%), and bla NDM (1%) beta-lactamase genes, class 1 integrons (38%), and the porin protein gene ompK36 (96%). The beta-lactamase genes bla TEM-1 , bla SHV-1 , bla SHV-11 , bla SHV-110 , bla SHV-190 , bla CTX-M-15 , bla CTX-M-3 , bla CTX-M-55 , bla OXA-48 , bla OXA-244 , and bla NDM-1 were detected; class 1 integron gene cassette arrays (aadA1), (dfrA7), (dfrA1-orfC), (aadB-aadA1), (dfrA17-aadA5), and (dfrA12-orfF-aadA2) were identified. Twenty-two (15%) of clinical K. pneumoniae strains had hypermucoviscous (HV) phenotype defined as string test positive. The rmpA gene associated with HV phenotype was detected in 24% of strains. The intrapersonal mutation of rmpA gene (deletion of one nucleotide at the polyG tract) was a reason for negative hypermucoviscosity phenotype and low virulence of rmpA-positive K. pneumoniae strain KPB584. Eighteen virulent for mice strains with LD 50  ≤ 10 4  CFU were attributed to sequence types ST23, ST86, ST218, ST65, ST2174, and ST2280 and to capsular types K1, K2, and K57. This study is the first report about hypervirulent K. pneumoniae strain KPB2580-14 of ST23 K1 harboring extended-spectrum beta-lactamase CTX-M-15 and carbapenemase OXA-48 genes located on pCTX-M-15-like and pOXA-48-like plasmids correspondingly.

Antimicrobial susceptibility trends among gram-positive and -negative clinical isolates collected between 2005 and 2012 in Mexico: results from the Tigecycline Evaluation and Surveillance Trial.

PubMed

Morfin-Otero, Rayo; Noriega, Eduardo Rodriguez; Dowzicky, Michael J

2015-12-15

The Tigecycline Evaluation and Surveillance Trial (T.E.S.T) is a global antimicrobial surveillance study of both gram-positive and gram-negative organisms. This report presents data on antimicrobial susceptibility among organisms collected in Mexico between 2005 and 2012 as part of T.E.S.T., and compares rates between 2005-2007 and 2008-2012. Each center in Mexico submitted at least 200 isolates per collection year; including 65 gram-positive isolates and 135 gram-negative isolates. Minimum inhibitory concentrations (MICs) were determined using Clinical Laboratory Standards Institute (CLSI) broth microdilution methodology and antimicrobial susceptibility was established using the 2013 CLSI-approved breakpoints. For tigecycline US Food and Drug Administration (FDA) breakpoints were applied. Isolates of E. coli and K. pneumoniae with a MIC for ceftriaxone of >1 mg/L were screened for ESBL production using the phenotypic confirmatory disk test according to CLSI guidelines. The rates of some key resistant phenotypes changed during this study: vancomycin resistance among Enterococcus faecium decreased from 28.6 % in 2005-2007 to 19.1 % in 2008-2012, while β-lactamase production among Haemophilus influenzae decreased from 37.6 to 18.9 %. Conversely, methicillin-resistant Staphylococcus aureus increased from 38.1 to 47.9 %, meropenem-resistant Acinetobacter spp. increased from 17.7 to 33.0 % and multidrug-resistant Acinetobacter spp. increased from 25.6 to 49.7 %. The prevalence of other resistant pathogens was stable over the study period, including extended-spectrum β-lactamase-positive Escherichia coli (39.0 %) and Klebsiella pneumoniae (25.0 %). The activity of tigecycline was maintained across the study years with MIC90s of ≤2 mg/L against Enterococcus spp., S. aureus, Streptococcus agalactiae, Streptococcus pneumoniae, Enterobacter spp., E. coli, K. pneumoniae, Klebsiella oxytoca, Serratia marcescens, H. influenzae, and Acinetobacter spp. All gram-positive organisms were susceptible to tigecycline and susceptibility among gram-negatives ranged from 95.0 % for K. pneumoniae to 99.7 % for E. coli. Antimicrobial resistance continues to be high in Mexico. Tigecycline was active against gram-positive and gram-negative organisms, including resistant phenotypes, collected during the study.

Pediatric Infection and Intestinal Carriage Due to Extended-Spectrum-Cephalosporin-Resistant Enterobacteriaceae

PubMed Central

Qin, Xuan; Oron, Assaf P.; Adler, Amanda L.; Wolter, Daniel J.; Berry, Jessica E.; Hoffman, Lucas; Weissman, Scott J.

2014-01-01

The objective of this study is to describe the epidemiology of intestinal carriage with extended-spectrum-cephalosporin-resistant Enterobacteriaceae in children with index infections with these organisms. Patients with resistant Escherichia coli or Klebsiella bacteria isolated from the urine or a normally sterile site between January 2006 and December 2010 were included in this study. Available infection and stool isolates underwent phenotypic and molecular characterization. Clinical data relevant to the infections were collected and analyzed. Overall, 105 patients were identified with 106 extended-spectrum-cephalosporin-resistant E. coli (n = 92) or Klebsiella (n = 14) strains isolated from urine or a sterile site. Among the 27 patients who also had stool screening for resistant Enterobacteriaceae, 17 (63%) had intestinal carriage lasting a median of 199 days (range, 62 to 1,576). There were no significant differences in demographic, clinical, and microbiological variables between those with and those without intestinal carriage. Eighteen (17%) patients had 37 subsequent resistant Enterobacteriaceae infections identified: 31 urine and 6 blood. In a multivariable analysis, antibiotic intake in the 91 days prior to subsequent urine culture was significantly associated with subsequent urinary tract infection with a resistant organism (hazard ratio, 14.3; 95% confidence interval [CI], 1.6 to 130.6). Intestinal carriage and reinfection were most commonly due to bacterial strains of the same sequence type and with the same resistance determinants as the index extended-spectrum-cephalosporin-resistant Enterobacteriaceae, but carriage and reinfection with different resistant Enterobacteriaceae strains also occurred. PMID:24798269

[Prevalence and features of pathogenic bacteria in the department of hematology without bone marrow transplantation in Peking Union Medical College Hospital from 2010 to 2012].

PubMed

Wnag, Lu; Yang, Chen; Zhang, Qian; Han, Bing; Zhuang, Jun-jing; Chen, Miao; Zou, Nong; Li, Jian; Duan, Ming-hui; Zhang, Wei; Zhu, Tie-nan; Xu, Ying; Wang, Shu-jie; Zhou, Dao-bin; Zhao, Yong-qiang; Zhang, Hui; Wang, Peng; Xu, Ying-chun

2014-08-01

To investigate the incidence, pathogens, and clinical features of infection in consecutive cases from 2010 to 2012 in Peking Union Medical College Hospital. The incidence, pathogen, treatment, and outcomes of patients with hematological diseases who had positive findings of bacterium in their samples from 2010 to 2012 were retrospectively analyzed. There were 449 positive samples (5.8%) from 4 890 patients during this period, among which 388 were proved to be with pathogenic bacteria. Samples separated from patients with community-aquired infections accounted for 8.4% of all positive samples. Most community-aquired infections were caused by Gram-negative bacteria (75%), although no multidrug-resistant bacteria was observed. Samples separated from patients with nosocomial infections accounted for 91.6% of all positive samples. Respiratory tract (49.4%) and peripheral blood (32.6%) were the most common samples with positive results. Skin soft tissues (10.4%), and urine (3.7%) were less common samples. Most of the pathogenic bacteria of the nosocomial infections were Gram-negative (66.9%). The most common Gram-negative bacteria included Escherichia coli (13.8%), Pseudomonas aeruginosa (12.1%), and Klebsiella pneumonia (12.1%), while Staphylococcus aureus (10.4%), Enterococcus faecium (7.0%), and Staphylococcus epidermidis (5.1%) were the most common Gram-positive bacteria. Gram-negative bacteria consisted of most of sputum samples and peripheral blood samples. Samples from the surface of skin wound and anal swab were composed largely by Gram-positive bacteria (63.8%). The detection rates of extended-spectrum beta-lactamase-producing Klebsiella pneumonia/Klebsiella oxytoca, Escherichia coli, and Proteus mirabilis were 24.0%, 87.9% and 38.4%, respectively. The resistance to Acinetobacter baumannii was serious. Multidrug-resistant, extensive drug resistant and pan drug resistant A. baumannii acountted for 74% of all A. Baumannii infections. Stenotrophomonas maltophilia showed low resistance to sulfamethoxazole/trimethoprim, levofloxacin and minocycline. Also, 22 methicillin-resistant Staphylococcus aureus and 9 methicillin-resistant Staphylococcus Epidermidis were detected, which were only sensitive to vancomycin, teicoplanin, and linezolid. All patients were treated in the haematology wards and most of them were under agranulocytosis or immunosuppression. Finally, 22 patients reached clinical recovery through anti-infective therapy, whereas 49 patients died. Among those deaths, 42 patients attributed to severe infections and infection-associated complications. Fourteen of all the deaths might be infected with drug-resistance bacteria. There were 61 samples proved to be bacteria colonization. Nonfermenters such as Acinetobacter baumannii and Stenotrophomonas maltophilia made up for a large amount of bacteria colonization. The pathogens of nosocomial infections in the hematology ward are mainly Gram-negative bacteria. The incidences and pathogens vary from different infection sites. Nosocomial infection still has a higher mortality rate. Once nonfermenters are detected positive, the pathogenic or colonial bacteria should be distinguished.

Genomic Characterization of Nonclonal mcr-1-Positive Multidrug-Resistant Klebsiella pneumoniae from Clinical Samples in Thailand

PubMed Central

Srijan, Apichai; Ruekit, Sirigade; Snesrud, Erik; Maybank, Rosslyn; Serichantalergs, Oralak; Kormanee, Rosarin; Sukhchat, Prawet; Sriyabhaya, Jossin; Hinkle, Mary; Crawford, John M.; McGann, Patrick; Swierczewski, Brett E.

2018-01-01

Multidrug-resistant Klebsiella pneumoniae strains are one of the most prevalent causes of nosocomial infections and pose an increasingly dangerous public health threat. The lack of remaining treatment options has resulted in the utilization of older drug classes, including colistin. As a drug of last resort, the discovery of plasmid-mediated colistin resistance by mcr-1 denotes the potential development of pandrug-resistant bacterial pathogens. To address the emergence of the mcr-1 gene, 118 gram-negative Enterobacteriaceae isolated from clinical samples collected at Queen Sirikit Naval Hospital in Chonburi, Thailand were screened for colistin resistance using automated antimicrobial susceptibility testing and conventional PCR screening. Two K. pneumoniae strains, QS17-0029 and QS17-0161, were positive for mcr-1, and both isolates were sequenced to closure using short- and long-read whole-genome sequencing. QS17-0029 carried 16 antibiotic resistance genes in addition to mcr-1, including 2 carbapenemases, blaNDM-1 and blaOXA-232. QS17-0161 carried 13 antibiotic resistance genes in addition to mcr-1, including the extended-spectrum β-lactamase blaCTX-M-55. Both isolates carried multiple plasmids, but mcr-1 was located alone on highly similar 33.9 Kb IncX4 plasmids in both isolates. The IncX4 plasmid shared considerable homology to other mcr-1-containing IncX4 plasmids. This is the first report of a clinical K. pneumoniae strain from Thailand carrying mcr-1 as well as the first strain to simultaneously carry mcr-1 and multiple carbapenemase genes (QS17-0029). The identification and characterization of these isolates serves to highlight the urgent need for continued surveillance and intervention in Southeast Asia, where extensively drug-resistant pathogens are being increasingly identified in hospital-associated infections. PMID:29688801

Genomic Characterization of Nonclonal mcr-1-Positive Multidrug-Resistant Klebsiella pneumoniae from Clinical Samples in Thailand.

PubMed

Srijan, Apichai; Margulieux, Katie R; Ruekit, Sirigade; Snesrud, Erik; Maybank, Rosslyn; Serichantalergs, Oralak; Kormanee, Rosarin; Sukhchat, Prawet; Sriyabhaya, Jossin; Hinkle, Mary; Crawford, John M; McGann, Patrick; Swierczewski, Brett E

2018-05-01

Multidrug-resistant Klebsiella pneumoniae strains are one of the most prevalent causes of nosocomial infections and pose an increasingly dangerous public health threat. The lack of remaining treatment options has resulted in the utilization of older drug classes, including colistin. As a drug of last resort, the discovery of plasmid-mediated colistin resistance by mcr-1 denotes the potential development of pandrug-resistant bacterial pathogens. To address the emergence of the mcr-1 gene, 118 gram-negative Enterobacteriaceae isolated from clinical samples collected at Queen Sirikit Naval Hospital in Chonburi, Thailand were screened for colistin resistance using automated antimicrobial susceptibility testing and conventional PCR screening. Two K. pneumoniae strains, QS17-0029 and QS17-0161, were positive for mcr-1, and both isolates were sequenced to closure using short- and long-read whole-genome sequencing. QS17-0029 carried 16 antibiotic resistance genes in addition to mcr-1, including 2 carbapenemases, bla NDM-1 and bla OXA-232 . QS17-0161 carried 13 antibiotic resistance genes in addition to mcr-1, including the extended-spectrum β-lactamase bla CTX-M-55 . Both isolates carried multiple plasmids, but mcr-1 was located alone on highly similar 33.9 Kb IncX4 plasmids in both isolates. The IncX4 plasmid shared considerable homology to other mcr-1-containing IncX4 plasmids. This is the first report of a clinical K. pneumoniae strain from Thailand carrying mcr-1 as well as the first strain to simultaneously carry mcr-1 and multiple carbapenemase genes (QS17-0029). The identification and characterization of these isolates serves to highlight the urgent need for continued surveillance and intervention in Southeast Asia, where extensively drug-resistant pathogens are being increasingly identified in hospital-associated infections.

Epidemiology of Carbapenem-Resistant Klebsiella pneumoniae Bloodstream Infections in a Chinese Children's Hospital: Predominance of New Delhi Metallo-β-Lactamase-1.

PubMed

Dong, Fang; Zhang, Ye; Yao, Kaihu; Lu, Jie; Guo, Lingyun; Lyu, Shuang; Yang, Ying; Wang, Yan; Zheng, Hongyan; Song, Wenqi; Liu, Gang

2018-03-01

The spread of carbapenem-resistant Klebsiella pneumoniae (CRKp) has become a significant problem worldwide; however, relevant data in children are limited. We performed a retrospective study to better understand the epidemiology of CRKp bloodstream infections at Beijing Children's Hospital. A total of 164 K. pneumoniae strains were collected from blood cultures between January 2011 and September 2014, of which 52 (31.7%) were CRKp strains. All 52 CRKp strains were multidrug resistant; 46 (88.5%) and 49 (94.2%) isolates were resistant to meropenem and imipenem, respectively. Low rates of resistance to amikacin (5.8%), levofloxacin (7.7%), and ciprofloxacin (15.4%) were observed. All isolates were susceptible to colistin. Among the tested carbapenem resistance genes, the predominant gene was bla NDM-1 , detected in 28 (53.8%) isolates, followed by bla IMP-4 (19, 36.5%) and bla KPC-2 (4, 7.7%). Multilocus sequence typing identified 31 sequence types (STs), the most predominant of which was ST782 (9, 29.0%). All ST782 strains were New Delhi metallo-β-lactamase-1 (NDM-1) producing. Four novel STs (ST2010, ST2011, ST2012, and ST2013) and two novel alleles (phoE243 and tonB324) were also detected. Hematologic disease was the most common underlying disease (73.1%). All children received initial empirical therapy. A total of 59.6% (31/52) patients received inappropriate empirical therapy, and 45.2% (14/31) changed antimicrobial therapy after blood culture results were obtained. The overall mortality rate was 11.5%. In conclusion, we observed a high rate of CRKp isolates collected from blood cultures and the predominance of NDM-1-producing K. pneumoniae among children from 2011 to 2014.

Population variability of the FimH type 1 fimbrial adhesin in Klebsiella pneumoniae.

PubMed

Stahlhut, Steen G; Chattopadhyay, Sujay; Struve, Carsten; Weissman, Scott J; Aprikian, Pavel; Libby, Stephen J; Fang, Ferric C; Krogfelt, Karen Angeliki; Sokurenko, Evgeni V

2009-03-01

FimH is an adhesive subunit of type 1 fimbriae expressed by different enterobacterial species. The enteric bacterium Klebsiella pneumoniae is an environmental organism that is also a frequent cause of sepsis, urinary tract infection (UTI), and liver abscess. Type 1 fimbriae have been shown to be critical for the ability of K. pneumoniae to cause UTI in a murine model. We show here that the K. pneumoniae fimH gene is found in 90% of strains from various environmental and clinical sources. The fimH alleles exhibit relatively low nucleotide and structural diversity but are prone to frequent horizontal-transfer events between different bacterial clones. Addition of the fimH locus to multiple-locus sequence typing significantly improved the resolution of the clonal structure of pathogenic strains, including the K1 encapsulated liver isolates. In addition, the K. pneumoniae FimH protein is targeted by adaptive point mutations, though not to the same extent as FimH from uropathogenic Escherichia coli or TonB from the same K. pneumoniae strains. Such adaptive mutations include a single amino acid deletion from the signal peptide that might affect the length of the fimbrial rod by affecting FimH translocation into the periplasm. Another FimH mutation (S62A) occurred in the course of endemic circulation of a nosocomial uropathogenic clone of K. pneumoniae. This mutation is identical to one found in a highly virulent uropathogenic strain of E. coli, suggesting that the FimH mutations are pathoadaptive in nature. Considering the abundance of type 1 fimbriae in Enterobacteriaceae, our present finding that fimH genes are subject to adaptive microevolution substantiates the importance of type 1 fimbria-mediated adhesion in K. pneumoniae.

Correlation of Klebsiella pneumoniae Comparative Genetic Analyses with Virulence Profiles in a Murine Respiratory Disease Model

PubMed Central

Tam, Hok-Hei; Yan, Pearlly; Pfeffer, Tia L.; Bundschuh, Ralf; Warawa, Jonathan M.

2014-01-01

Klebsiella pneumoniae is a bacterial pathogen of worldwide importance and a significant contributor to multiple disease presentations associated with both nosocomial and community acquired disease. ATCC 43816 is a well-studied K. pneumoniae strain which is capable of causing an acute respiratory disease in surrogate animal models. In this study, we performed sequencing of the ATCC 43816 genome to support future efforts characterizing genetic elements required for disease. Furthermore, we performed comparative genetic analyses to the previously sequenced genomes from NTUH-K2044 and MGH 78578 to gain an understanding of the conservation of known virulence determinants amongst the three strains. We found that ATCC 43816 and NTUH-K2044 both possess the known virulence determinant for yersiniabactin, as well as a Type 4 secretion system (T4SS), CRISPR system, and an acetonin catabolism locus, all absent from MGH 78578. While both NTUH-K2044 and MGH 78578 are clinical isolates, little is known about the disease potential of these strains in cell culture and animal models. Thus, we also performed functional analyses in the murine macrophage cell lines RAW264.7 and J774A.1 and found that MGH 78578 (K52 serotype) was internalized at higher levels than ATCC 43816 (K2) and NTUH-K2044 (K1), consistent with previous characterization of the antiphagocytic properties of K1 and K2 serotype capsules. We also examined the three K. pneumoniae strains in a novel BALB/c respiratory disease model and found that ATCC 43816 and NTUH-K2044 are highly virulent (LD50<100 CFU) while MGH 78578 is relatively avirulent. PMID:25203254

Analysis of eight out genes in a cluster required for pectic enzyme secretion by Erwinia chrysanthemi: sequence comparison with secretion genes from other gram-negative bacteria.

PubMed Central

Lindeberg, M; Collmer, A

1992-01-01

Many extracellular proteins produced by Erwinia chrysanthemi require the out gene products for transport across the outer membrane. In a previous report (S. Y. He, M. Lindeberg, A. K. Chatterjee, and A. Collmer, Proc. Natl. Acad. Sci. USA 88:1079-1083, 1991) cosmid pCPP2006, sufficient for secretion of Erwinia chrysanthemi extracellular proteins by Escherichia coli, was partially sequenced, revealing four out genes sharing high homology with pulH through pulK from Klebsiella oxytoca. The nucleotide sequence of eight additional out genes reveals homology with pulC through pulG, pulL, pulM, pulO, and other genes involved in secretion by various gram-negative bacteria. Although signal sequences and hydrophobic regions are generally conserved between Pul and Out proteins, four out genes contain unique inserts, a pulN homolog is not present, and outO appears to be transcribed separately from outC through outM. The sequenced region was subcloned, and an additional 7.6-kb region upstream was identified as being required for secretion in E. coli. out gene homologs were found on Erwinia carotovora cosmid clone pAKC651 but were not detected in E. coli. The outC-through-outM operon is weakly induced by polygalacturonic acid and strongly expressed in the early stationary phase. The out and pul genes are highly similar in sequence, hydropathic properties, and overall arrangement but differ in both transcriptional organization and the nature of their induction. Images PMID:1429461

Etiologic profile and antimicrobial susceptibility of community-acquired urinary tract infection in two Cameroonian towns.

PubMed

Akoachere, Jane-Francis Tatah Kihla; Yvonne, Suylika; Akum, Njom Henry; Seraphine, Esemu Nkie

2012-05-07

Urinary tract infection (UTI) represents one of the most common diseases encountered in community medical practice. In resource poor settings, treatment is usually empiric due to the high cost and long duration required for reporting diagnosis by culture and antibiotic susceptibility testing. With the growing problem of drug resistance knowledge of antibiotic susceptibility pattern is pertinent for successful eradication of invading pathogens. Our study, the first of its kind in Cameroon, analyzed the distribution and antibiotic susceptibility of bacteria causing community-acquired urinary tract infection (CAUTI) in two towns (Bamenda and Buea) with a large number of young and middle aged persons, to provide data that could guide empiric treatment. We cultured 235 urine specimens and analyzed the antibiotic susceptibility of isolates by the disc diffusion technique. Uropathogens were recovered from 137 (58.3%), with prevalence rates in Buea and Bamenda being 65.9% and 54% respectively. Predominant pathogens were Escherichia coli (31.4%), Klebsiella oxytoca (25.5%) and Staphylococcus spp (24.1%). Geographic variation in uropathogen distribution and antibiotic susceptibility was observed, and a significant difference in pathogen distribution with respect to gender. The 20-39 years age group had the highest prevalence of infection. All pathogens isolated were detected in this group. Isolates exhibited low susceptibility to antibiotics tested. Bamenda isolates generally exhibited lower susceptibility compared to those from Buea. Regional variation in etiology of CAUTI and antibiotic susceptibility observed in our study emphasizes the need to establish local and national antimicrobial resistance monitoring systems in Cameroon to provide information for the development of CAUTI treatment guidelines.

Occurrence of yeasts, enterococci and other enteric bacteria in subgingival biofilm of HIV-positive patients with chronic gingivitis and necrotizing periodontitis

PubMed Central

Gaetti-Jardim Júnior, Elerson; Nakano, Viviane; Wahasugui, Thais C.; Cabral, Fátima C.; Gamba, Rosa; Avila-Campos, Mario Julio

2008-01-01

The purpose of this study was to determine the prevalence of enteric bacteria and yeasts in biofilm of 80 HIV-positive patients with plaque-associated gingivitis or necrotizing periodontitis. Patients were subjected to extra, intra oral and radiographic examinations. The oral hygiene, bleeding on probing, gingival conditions, and attachment loss were evaluated. Clinical specimens were collected from gingival crevices or periodontal pockets, transferred to VMGA III, diluted and transferred to Sabouraud Dextrose agar with 100 μg/ml of chloramphenicol, peptone water, EVA broth, EMB agar, SS agar, Bile esculin agar and Brilliant green agar. Isolation of yeasts was carried out at room temperature, for 3-7 days; and for the isolation of enteric microorganisms plates were incubated at 37°C, for 24-48 h. The yeasts identification was performed according to the carbon and nitrogen assimilation, fermentation of carbohydrates and germ tube formation. Bacteria were identified according to their colonial and cellular morphologies and biochemical tests. Yeasts were identified as Candida albicans and its occurrence was more common in patients with CD4+ below 200/mm3 and was affected by the extension of periodontal involvement (P = 0.0345). Enteric bacteria recovered from clinical specimens were identified as Enterobacter sakazakii, Enterobacter cloacae, Serratia liquefaciens, Klebsiella oxytoca and Enterococcus sp. Enterobacteriaceae and enterococci were detected in 32.5% of clinical samples from patients with necrotizing periodontitis. In conclusion, non-oral pathogenic bacteria and C. albicans were more prevalent in periodontal sites of HIV-positive patients with necrotizing periodontitis and chronic gingivitis. PMID:24031212

Bioactive endophytic fungi isolated from Caesalpinia echinata Lam. (Brazilwood) and identification of beauvericin as a trypanocidal metabolite from Fusarium sp.

PubMed Central

Campos, Fernanda Fraga; Sales, Policarpo A; Romanha, Alvaro José; Araújo, Márcio SS; Siqueira, Ezequias P; Resende, Jarbas M; Alves, Tânia MA; Martins-Filho, Olindo A; dos Santos, Vera Lúcia; Rosa, Carlos A; Zani, Carlos L; Cota, Betania Barros

2015-01-01

Aiming to identify new sources of bioactive secondary metabolites, we isolated 82 endophytic fungi from stems and barks of the native Brazilian tree Caesalpinia echinata Lam. (Fabaceae). We tested their ethyl acetate extracts in several in vitro assays. The organic extracts from three isolates showed antibacterial activity against Staphylococcus aureus and Escherichia coli [minimal inhibitory concentration (MIC) 32-64 μg/mL]. One isolate inhibited the growth of Salmonella typhimurium (MIC 64 μg/mL) and two isolates inhibited the growth of Klebsiella oxytoca (MIC 64 μg/mL), Candida albicans and Candida tropicalis (MIC 64-128 μg/mL). Fourteen extracts at a concentration of 20 μg/mL showed antitumour activities against human breast cancer and human renal cancer cells, while two isolates showed anti-tumour activities against human melanoma cancer cells. Six extracts were able to reduce the proliferation of human peripheral blood mononuclear cells, indicating some degree of selective toxicity. Four isolates were able to inhibit Leishmania (Leishmania) amazonensis and one isolate inhibited Trypanosoma cruzi by at least 40% at 20 μg/mL. The trypanocidal extract obtained from Fusarium sp. [KF611679] culture was subjected to bioguided fractionation, which revealed beauvericin as the compound responsible for the observed toxicity of Fusarium sp. to T. cruzi. This depsipeptide showed a half maximal inhibitory concentration of 1.9 μg/mL (2.43 μM) in a T. cruzi cellular culture assay. PMID:25742265

Dual chemistry catalyzed by human acireductone dioxygenase

PubMed Central

Deshpande, Aditi R.; Pochapsky, Thomas C.; Petsko, Gregory A.

2017-01-01

Abstract Acireductone dioxygenase (ARD) from the methionine salvage pathway of Klebsiella oxytoca is the only known naturally occurring metalloenzyme that catalyzes different reactions in vivo based solely on the identity of the divalent transition metal ion (Fe2+ or Ni2+) bound in the active site. The iron-containing isozyme catalyzes the cleavage of substrate 1,2-dihydroxy-3-keto-5-(thiomethyl)pent-1-ene (acireductone) by O2 to formate and the ketoacid precursor of methionine, whereas the nickel-containing isozyme uses the same substrates to catalyze an off-pathway shunt to form methylthiopropionate, carbon monoxide and formate. This dual chemistry was recently demonstrated in vitro by ARD from Mus musculus (MmARD), providing the first example of a mammalian ARD exhibiting metal-dependent catalysis. We now show that human ARD (HsARD) is also capable of metal-dependent dual chemistry. Recombinant HsARD was expressed and purified to obtain a homogeneous enzyme with a single transition metal ion bound. As with MmARD, the Fe2+-bound HsARD shows the highest activity and catalyzes on-pathway chemistry, whereas Ni2+, Co2+ or Mn2+ forms catalyze off-pathway chemistry. The thermal stability of the HsARD isozymes is a function of the metal ion identity, with Ni2+-bound HsARD being the most stable followed by Co2+ and Fe2+, and Mn2+-bound HsARD being the least stable. As with the bacterial ARD, solution NMR data suggest that HsARD isozymes can have significant structural differences depending upon the metal ion bound. PMID:28062648

Structure of the Minor Pseudopilin EpsH From the Type 2 Secretion System of Vibrio Cholerae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yanez, M.E.; Korotkov, K.V.; Abendroth, J.

2009-05-28

Many Gram-negative bacteria use the multi-protein type II secretion system (T2SS) to selectively translocate virulence factors from the periplasmic space into the extracellular environment. In Vibrio cholerae the T2SS is called the extracellular protein secretion (Eps) system, which translocates cholera toxin and several enzymes in their folded state across the outer membrane. Five proteins of the T2SS, the pseudopilins, are thought to assemble into a pseudopilus, which may control the outer membrane pore EpsD, and participate in the active export of proteins in a 'piston-like' manner. We report here the 2.0 {angstrom} resolution crystal structure of an N-terminally truncated variantmore » of EpsH, a minor pseudopilin from Vibrio cholerae. While EpsH maintains an N-terminal {alpha}-helix and C-terminal {beta}-sheet consistent with the type 4a pilin fold, structural comparisons reveal major differences between the minor pseudopilin EpsH and the major pseudopilin GspG from Klebsiella oxytoca: EpsH contains a large {beta}-sheet in the variable domain, where GspG contains an {alpha}-helix. Most importantly, EpsH contains at its surface a hydrophobic crevice between its variable and conserved {beta}-sheets, wherein a majority of the conserved residues within the EpsH family are clustered. In a tentative model of a T2SS pseudopilus with EpsH at its tip, the conserved crevice faces away from the helix axis. This conserved surface region may be critical for interacting with other proteins from the T2SS machinery.« less

Antimicrobial activity of α-(2-hydroxy-2-methylpropyl)-ω-(2-hydroxy-3-methylbut-2-en-1-yl) polymethylene from caesalpinia bonducella (L.) Flem

PubMed Central

Sagar, Kavitha; Vidyasagar, G. M.

2010-01-01

The compound, α-(2-hydroxy-2-methylpropyl)-ω-(2-hydroxy-3-methylbut-2-en-1-yl)polymethylene, isolated from ethyl acetate leaf extract of Caesalpinia bonducella (L.) Flem. was evaluated for antimicrobial activity against clinical isolates, Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella sp., Staphylococcus citrus, Staphylococcus aureus, Escherichia coli, Candida albicans and Rhodotorula sp. using agar diffusion method. The compound exerted inhibitory zone at all concentrations and revealed the concentration-dependent activity against all tested bacterial and yeast strains comparable to standards streptomycin sulphate and gentamycin for bacteria and fluconazole and griseofulvin for Candida albicans and Rhodotorula sp. The inhibition zones were wider and clear for C. albicans and Rhodotorula sp. (IZ >20 mm) and for Pseudomonas aeruginosa, P. vulgaris and E. coli zones were greater than standards tested, whereas, zones for Klebsiella sp. and S. aureus were similar to standards. PMID:21218063

Frequency, Antimicrobial Resistance and Genetic Diversity of Klebsiella pneumoniae in Food Samples

PubMed Central

Pang, Zhizhao; Qin, Tian; Ren, Hongyu; Pan, Zhuo; Zhou, Jikun

2016-01-01

This study aimed to assess the frequency of Klebsiella pneumoniae in food samples and to detect antibiotic resistance phenotypes, antimicrobial resistance genes and the molecular subtypes of the recovered isolates. A total of 998 food samples were collected, and 99 (9.9%) K. pneumoniae strains were isolated; the frequencies were 8.2% (4/49) in fresh raw seafood, 13.8% (26/188) in fresh raw chicken, 11.4% (34/297) in frozen raw food and 7.5% (35/464) in cooked food samples. Antimicrobial resistance was observed against 16 antimicrobials. The highest resistance rate was observed for ampicillin (92.3%), followed by tetracycline (31.3%), trimethoprim-sulfamethoxazole (18.2%), and chloramphenicol (10.1%). Two K. pneumoniae strains were identified as extended-spectrum β-lactamase (ESBL)–one strain had three beta-lactamases genes (blaSHV, blaCTX-M-1, and blaCTX-M-10) and one had only the blaSHV gene. Nineteen multidrug-resistant (MDR) strains were detected; the percentage of MDR strains in fresh raw chicken samples was significantly higher than in other sample types (P<0.05). Six of the 18 trimethoprim-sulfamethoxazole-resistant strains carried the folate pathway inhibitor gene (dhfr). Four isolates were screened by PCR for quinolone resistance genes; aac(6’)-Ib-cr, qnrB, qnrA and qnrS were detected. In addition, gyrA gene mutations such as T247A (Ser83Ile), C248T (Ser83Phe), and A260C (Asp87Ala) and a parC C240T (Ser80Ile) mutation were identified. Five isolates were screened for aminoglycosides resistance genes; aacA4, aacC2, and aadA1 were detected. Pulsed-field gel electrophoresis-based subtyping identified 91 different patterns. Our results indicate that food, especially fresh raw chicken, is a reservoir of antimicrobial-resistant K. pneumoniae, and the potential health risks posed by such strains should not be underestimated. Our results demonstrated high prevalence, antibiotic resistance rate and genetic diversity of K. pneumoniae in food in China. Improved control and prevention strategies are urgently needed. PMID:27078494

Draft Genome Sequences of Escherichia coli Isolates from Wounded Military Personnel.

PubMed

Arivett, Brock A; Ream, Dave C; Fiester, Steven E; Kidane, Destaalem; Actis, Luis A

2016-08-11

Members of the Escherichia coli bacterial family have been grouped as ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens because of their extensive drug resistance phenotypes and increasing threat to human health. The genomes of six extended-spectrum β-lactamase (ESBL)-producing E. coli strains isolated from wounded military personnel were sequenced and annotated. Copyright © 2016 Arivett et al.

Methanobrevibacter attenuation via probiotic intervention reduces flatulence in adult human: A non-randomised paired-design clinical trial of efficacy.

PubMed

Seo, Minseok; Heo, Jaeyoung; Yoon, Joon; Kim, Se-Young; Kang, Yoon-Mo; Yu, Jihyun; Cho, Seoae; Kim, Heebal

2017-01-01

The aim of this study was to investigate which of the gut microbes respond to probiotic intervention, as well as study whether they are associated with gastrointestinal symptoms in a healthy adult human. For the experimental purpose, twenty-one healthy adults were recruited and received probiotic mixture, which is composed of five Lactobacilli strains and two Bifidobacteria strains, once a day for 60 days. Defecation survey and Bioelectrical Impedance Analysis were conducted pre- and post-administration to measure phenotypic differences. Stool samples of the subjects were collected twice. The statistical analysis was performed for pair designed metagenome data with 11 phenotypic records of the bioelectrical impedance body composition analyzer and 6 responses of the questionnaires about gastrointestinal symptom. Furthemore, correlation-based network analysis was conducted for exploring complex relationships among microbiome communities. The abundances of Citrobacter, Klebsiella, and Methanobrevibacter were significantly reduced, which are strong candidates to be highly affected by the probiotic administration. In addition, interaction effects were observed between flatulence symptom attenuation and decreasing patterns of the Methanobrevibacter abundance. These results reveal that probiotic intervention modulated the composition of gut microbiota and reduced the abundance of potential pathogens (i.e. Citrobacter and Klebsiella). In addition, methanogens (i.e. Methanobrevibacter) associated with the gastrointestinal symptom in an adult human.

The Klebsiella pneumoniae YfgL (BamB) lipoprotein contributes to outer membrane protein biogenesis, type-1 fimbriae expression, anti-phagocytosis, and in vivo virulence

PubMed Central

Hsieh, Pei-Fang; Hsu, Chun-Ru; Chen, Chun-Tang; Lin, Tzu-Lung; Wang, Jin-Town

2016-01-01

ABSTRACT Klebsiella pneumoniae is an opportunistic pathogen that causes several kinds of infections, including pneumonia, bacteremia, urinary tract infection and community-acquired pyogenic liver abscess (PLA). Adhesion is the critical first step in the infection process. Our previous work demonstrated that the transcellular translocation is exploited by K. pneumoniae strains to migrate from the gut flora into other tissues, resulting in systemic infections. However, the initial stages of K. pneumoniae infection remain unclear. In this study, we demonstrated that a K. pneumoniae strain deleted for yfgL (bamB) exhibited reduced adherence to and invasion of host cells; changed biogenesis of major β-barrel outer membrane proteins; decreased transcriptional expression of type-1 fimbriae; and increased susceptibility to vancomycin and erythromycin. The yfgL deletion mutant also had reduced ability to against neutrophil phagocytosis; exhibited decreased induction of host IL-6 production; and was profoundly attenuated for virulence in a K. pneumoniae model of bacteremia. Thus, the K. pneumoniae YfgL lipoprotein mediates in outer membrane proteins biogenesis and is crucial for anti-phagocytosis and survival in vivo. These data provide a new insight for K. pneumoniae attachment and such knowledge could facilitate preventive therapies or alternative therapies against K. pneumoniae. PMID:27029012

Enterobacteria identification and detection of diarrheagenic Escherichia coli in a Port Complex

PubMed Central

Costa, Clarissa Frota Macatrão; Neto, Valério Monteiro; Santos, Bruno Rafael de Carvalho; Costa, Bruno Rafael Rabelo; Azevedo, Alexandre; Serra, Josilene Lima; Mendes, Hermínio Benítez Rabello; Nascimento, Adenilde Ribeiro; Mendes, Mariana Bonfim Pinto; Kuppinger, Oliver

2014-01-01

The Port Complex of Maranhão (PCM) is the second largest port complex in Brazil, receiving ships with large volumes of ballast water. To evaluate the microbiological quality of its waters, physicochemical parameters (pH and salinity), the number of coliforms (thermotolerants and totals), and the presence of enterobacterias and diarrheagenic Escherichia coli strains were analyzed. In order to identify the presence of E. coli virulence genes target regions of the stx, elt, est, aggR, CVD432, ipaH and eae nucleotide sequences were studied. The presence of totals and thermotolerants coliforms were positive. Analyzing the salinity parameter, a significant increase in total coliforms was observed during the rainy season. We identified the species Escherichia coli, Proteus mirabilis, Citrobacter freundii, Proteus vulgaris, Klebsiella pneumoniae, Klebsiella ozaenae, Morganella morganii, Enterobacter cloacae and Edwardsiella tarda. Out of the 51 E. coli isolated, two were positive for the elt gene and one was positive for the CVD432 sequence, features of enterotoxigenic and enteroaggregative strains, respectively. This study reveals that the PCM is contaminated by enterobacteria and diarrheagenic E.coli thus providing evidence regarding the risk of these bacteria being carried by ships to other countries, and draws attention to the input of fecal bacteria brought by ships in the port waters of Maranhão. PMID:25477930

Hypervirulence and hypermucoviscosity: Two different but complementary Klebsiella spp. phenotypes?

PubMed Central

Catalán-Nájera, Juan Carlos; Garza-Ramos, Ulises; Barrios-Camacho, Humberto

2017-01-01

ABSTRACT Since the hypermucoviscous variants of Klebsiella pneumoniae were first reported, many cases of primary liver abscesses and other invasive infections caused by this pathogen have been described worldwide. Hypermucoviscosity is a phenotypic feature characterized by the formation of a viscous filament ≥5 mm when a bacterial colony is stretched by a bacteriological loop; this is the so-called positive string test. Hypermucoviscosity appears to be associated with this unusual and aggressive type of infection, and therefore, the causal strains are considered hypervirulent. Since these first reports, the terms hypermucoviscosity and hypervirulence have often been used synonymously. However, new evidence has suggested that hypermucoviscosity and hypervirulence are 2 different phenotypes that should not be used synonymously. Moreover, it is important to establish that a negative string test is insufficient in determining whether a strain is or is not hypervirulent. On the other hand, hypervirulence- and hypermucoviscosity-associated genes must be identified, considering that these phenotypes correspond to 2 different phenomena, regardless of whether they can act in synergy under certain circumstances. Therefore, it is essential to quickly identify the genetic determinants behind the hypervirulent phenotype to develop effective methodologies that can diagnose in a prompt and effective way these hypervirulent variants of K. pneumoniae. PMID:28402698

Biofilms from Klebsiella pneumoniae: Matrix Polysaccharide Structure and Interactions with Antimicrobial Peptides

PubMed Central

Benincasa, Monica; Lagatolla, Cristina; Dolzani, Lucilla; Milan, Annalisa; Pacor, Sabrina; Liut, Gianfranco; Tossi, Alessandro; Cescutti, Paola; Rizzo, Roberto

2016-01-01

Biofilm matrices of two Klebsiella pneumoniae clinical isolates, KpTs101 and KpTs113, were investigated for their polysaccharide composition and protective effects against antimicrobial peptides. Both strains were good biofilm producers, with KpTs113 forming flocs with very low adhesive properties to supports. Matrix exopolysaccharides were isolated and their monosaccharide composition and glycosidic linkage types were defined. KpTs101 polysaccharide is neutral and composed only of galactose, in both pyranose and furanose ring configurations. Conversely, KpTs113 polysaccharide is anionic due to glucuronic acid units, and also contains glucose and mannose residues. The susceptibility of the two strains to two bovine cathelicidin antimicrobial peptides, BMAP-27 and Bac7(1–35), was assessed using both planktonic cultures and biofilms. Biofilm matrices exerted a relevant protection against both antimicrobials, which act with quite different mechanisms. Similar protection was also detected when antimicrobial peptides were tested against planktonic bacteria in the presence of the polysaccharides extracted from KpTs101 and KpTs113 biofilms, suggesting sequestering adduct formation with antimicrobials. Circular dichroism experiments on BMAP-27 in the presence of increasing amounts of either polysaccharide confirmed their ability to interact with the peptide and induce an α-helical conformation. PMID:27681920

Genomic Analysis of the Emergence and Rapid Global Dissemination of the Clonal Group 258 Klebsiella pneumoniae Pandemic

PubMed Central

Driebe, Elizabeth M.; MacCannell, Duncan R.; Roe, Chandler; Lemmer, Darrin; de Man, Tom; Rasheed, J. Kamile; Engelthaler, David M.; Keim, Paul; Limbago, Brandi M.

2015-01-01

Multidrug-resistant Klebsiella pneumoniae producing the KPC carbapenemase have rapidly spread throughout the world, causing severe healthcare-associated infections with limited antimicrobial treatment options. Dissemination of KPC-producing K. pneumoniae is largely attributed to expansion of a single dominant strain, ST258. In this study, we explore phylogenetic relationships and evolution within ST258 and its clonal group, CG258, using whole genome sequence analysis of 167 isolates from 20 countries collected over 17 years. Our results show a common ST258 ancestor emerged from its diverse parental clonal group around 1995 and likely acquired bla KPC prior to dissemination. Over the past two decades, ST258 has remained highly clonal despite diversity in accessory elements and divergence in the capsule polysaccharide synthesis locus. Apart from the large recombination event that gave rise to ST258, few mutations set it apart from its clonal group. However, one mutation occurs in a global transcription regulator. Characterization of outer membrane protein sequences revealed a profile in ST258 that includes a truncated OmpK35 and modified OmpK37. Our work illuminates potential genomic contributors to the pathogenic success of ST258, helps us better understand the global dissemination of this strain, and identifies genetic markers unique to ST258. PMID:26196384

The Klebsiella pneumoniae wabG Gene: Role in Biosynthesis of the Core Lipopolysaccharide and Virulence

PubMed Central

Izquierdo, Luis; Coderch, Núria; Piqué, Nuria; Bedini, Emiliano; Michela Corsaro, Maria; Merino, Susana; Fresno, Sandra; Tomás, Juan M.; Regué, Miguel

2003-01-01

To determine the function of the wabG gene in the biosynthesis of the core lipopolysaccharide (LPS) of Klebsiella pneumoniae, we constructed wabG nonpolar mutants. Data obtained from the comparative chemical and structural analysis of LPS samples obtained from the wild type, the mutant strain, and the complemented mutant demonstrated that the wabG gene is involved in attachment to α-l-glycero-d-manno-heptopyranose II (l,d-HeppII) at the O-3 position of an α-d-galactopyranosyluronic acid (α-d-GalAp) residue. K. pneumoniae nonpolar wabG mutants were devoid of the cell-attached capsular polysaccharide but were still able to produce capsular polysaccharide. Similar results were obtained with K. pneumoniae nonpolar waaC and waaF mutants, which produce shorter LPS core molecules than do wabG mutants. Other outer core K. pneumoniae nonpolar mutants in the waa gene cluster were encapsulated. K. pneumoniae waaC, waaF, and wabG mutants were avirulent when tested in different animal models. Furthermore, these mutants were more sensitive to some hydrophobic compounds than the wild-type strains. All these characteristics were rescued by reintroduction of the waaC, waaF, and wabG genes from K. pneumoniae. PMID:14645282

[Clinical analysis for patients with continuous ambulatory peritoneal dialysis associated peritonitis].

PubMed

Liu, Jian; Huang, Xun; Liu, Yao; Xu, Hui; Gong, Rui'e; Li, Chunhui

2016-12-28

To analyze the clinical characteristics of continuous ambulatory peritoneal dialysis (CAPD) associated peritonitis in the tertiary hospitals and to discuss the preventive and therapeutic strategy.
 Methods: The clinical characteristics, pathogens, resistance and outcomes of 126 CAPD associated peritonitis in 104 patients from Jan, 2013 to June, 2016, were retrospectively analyzed.
 Results: Among the patients, the incidence rates of abdominal pain, fever, diarrhea and emesis were 104 (82.54%), 56 (44.44%), 49 (38.89%), and 31 (23.60%), respectively. Among them, 88 patients suffered peritonitis once, other 16 patients suffered multiple peritonitis or recurrent peritonitis for 38 times. Among the 38 times, the numbers for recurrent, repeated or catheter-associated peritonitis were 2, 2, or 3, respectively. Peritoneal fluids from 103 cases were cultured, and 64 cases were positive in bacteria, with a rate of 62.14%. A total of 70 strains of bacteria were separated, including 42 strains of gram-positive bacteria, 21 strains of gram-negative bacteria, and 7 strains of fungus. The most common gram-positive pathogens were Staphylococcus epidermidis, Enterococcus faecalis and Staphylococcus haemolyticus, while Escherichia coli, Klebsiella pneumoniae and Klebsiella pneumoniae were the most common gram-negative bacteria. Candida albicans was the major fungal pathogens. Gram-positive cocci showed resistance to gentamycin, levofloxacin, moxifloxacin, vancomycin and linezolid, with a rate at 20.00%, 36.11%, 5%, 0%, and 0%, respectively. The gram-negative bacilli were resistent to cefoperazone/sulbactam, gentamycin, cephazolin, and ceftazidime, with a rate at 6.25%, 10.53%, 64.29%, and 15.38%, respectively. There were no imipenem, amikacin, piperacillin/tazobactam-resistant strains were found.
 Conclusion: The most common pathogen causing CAPD associated peritonitis is gram-positive bacteria. It is crucial to take the anti-infection therapy for CAPD associated peritonitis early. The positive rates for bacterial culture need to be enhanced through improvement of methods. At the same time, doctors could improve the outcome of CAPD associated peritonitis by adjusting the medication according to the drug sensitivity results.

Novel Carbapenem-Hydrolyzing β-Lactamase, KPC-1, from a Carbapenem-Resistant Strain of Klebsiella pneumoniae

PubMed Central

Yigit, Hesna; Queenan, Anne Marie; Anderson, Gregory J.; Domenech-Sanchez, Antonio; Biddle, James W.; Steward, Christine D.; Alberti, Sebastian; Bush, Karen; Tenover, Fred C.

2001-01-01

A Klebsiella pneumoniae isolate showing moderate to high-level imipenem and meropenem resistance was investigated. The MICs of both drugs were 16 μg/ml. The β-lactamase activity against imipenem and meropenem was inhibited in the presence of clavulanic acid. The strain was also resistant to extended-spectrum cephalosporins and aztreonam. Isoelectric focusing studies demonstrated three β-lactamases, with pIs of 7.2 (SHV-29), 6.7 (KPC-1), and 5.4 (TEM-1). The presence of blaSHV and blaTEM genes was confirmed by specific PCRs and DNA sequence analysis. Transformation and conjugation studies with Escherichia coli showed that the β-lactamase with a pI of 6.7, KPC-1 (K. pneumoniae carbapenemase-1), was encoded on an approximately 50-kb nonconjugative plasmid. The gene, blaKPC-1, was cloned in E. coli and shown to confer resistance to imipenem, meropenem, extended-spectrum cephalosporins, and aztreonam. The amino acid sequence of the novel carbapenem-hydrolyzing β-lactamase, KPC-1, showed 45% identity to the pI 9.7 carbapenem-hydrolyzing β-lactamase, Sme-1, from Serratia marcescens S6. Hydrolysis studies showed that purified KPC-1 hydrolyzed not only carbapenems but also penicillins, cephalosporins, and monobactams. KPC-1 had the highest affinity for meropenem. The kinetic studies also revealed that clavulanic acid and tazobactam inhibited KPC-1. An examination of the outer membrane proteins of the parent K. pneumoniae strain demonstrated that the strain does not express detectable levels of OmpK35 and OmpK37, although OmpK36 is present. We concluded that carbapenem resistance in K. pneumoniae strain 1534 is mainly due to production of a novel Bush group 2f, class A, carbapenem-hydrolyzing β-lactamase, KPC-1, although alterations in porin expression may also play a role. PMID:11257029

Impact of blaNDM-1 on fitness and pathogenicity of Escherichia coli and Klebsiella pneumoniae.

PubMed

Göttig, Stephan; Riedel-Christ, Sara; Saleh, Ahmad; Kempf, Volkhard A J; Hamprecht, Axel

2016-06-01

The objective of this study was to determine whether acquisition of New Delhi metallo-β-lactamase-1 (NDM-1) has an impact on the fitness and virulence of Escherichia coli and Klebsiella pneumoniae. Growth kinetics and the cost of fitness of NDM-1 plasmid carriage were assessed in isogenic E. coli J53 and K. pneumoniae PRZ in vitro by pairwise competition assays. The pathogenicity of NDM-1-expressing E. coli and K. pneumoniae strains and their isogenic controls was analysed in vivo using a Galleria mellonella infection model. The cytotoxicity of NDM-1 was assessed in A549 human lung epithelial cells using the lactate dehydrogenase (LDH) assay. No differences in growth kinetics were recorded between NDM-1-expressing strains and controls (P = 0.92). A reduction in fitness of NDM-1-carrying strains was observed both for E. coli J53 and K. pneumoniae PRZ [selection rate constant (s) = -1.27 ± 0.27 for E. coli J53 and -0.19 ± 0.14 for K. pneumoniae PRZ; P < 0.0001]. Survival of G. mellonella larvae infected with NDM-1-expressing strains and controls was similar for E. coli J53 and K. pneumoniae PRZ. Cytotoxicity in A549 cells was not affected by NDM-1 expression (P > 0.05). The presence of blaNDM-1 did not increase the virulence or cytotoxicity of isogenic strains. However, there was a considerable cost of fitness incurred by carriage of the pNDM-1 plasmid. Interestingly, the cost of fitness was significantly higher in E. coli J53 compared with K. pneumoniae PRZ. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Mapping the resistance-associated mobilome of a carbapenem-resistant Klebsiella pneumoniae strain reveals insights into factors shaping these regions and facilitates generation of a 'resistance-disarmed' model organism.

PubMed

Bi, Dexi; Jiang, Xiaofei; Sheng, Zi-Ke; Ngmenterebo, David; Tai, Cui; Wang, Minggui; Deng, Zixin; Rajakumar, Kumar; Ou, Hong-Yu

2015-10-01

This study aims to investigate the landscape of the mobile genome, with a focus on antibiotic resistance-associated factors in carbapenem-resistant Klebsiella pneumoniae. The mobile genome of the completely sequenced K. pneumoniae HS11286 strain (an ST11, carbapenem-resistant, near-pan-resistant, clinical isolate) was annotated in fine detail. The identified mobile genetic elements were mapped to the genetic contexts of resistance genes. The blaKPC-2 gene and a 26 kb region containing 12 clustered antibiotic resistance genes and one biocide resistance gene were deleted, and the MICs were determined again to ensure that antibiotic resistance had been lost. HS11286 contains six plasmids, 49 ISs, nine transposons, two separate In2-related integron remnants, two integrative and conjugative elements (ICEs) and seven prophages. Sixteen plasmid-borne resistance genes were identified, 14 of which were found to be directly associated with Tn1721-, Tn3-, Tn5393-, In2-, ISCR2- and ISCR3-derived elements. IS26 appears to have actively moulded several of these genetic regions. The deletion of blaKPC-2, followed by the deletion of a 26 kb region containing 12 clustered antibiotic resistance genes, progressively decreased the spectrum and level of resistance exhibited by the resultant mutant strains. This study has reiterated the role of plasmids as bearers of the vast majority of resistance genes in this species and has provided valuable insights into the vital role played by ISs, transposons and integrons in shaping the resistance-coding regions in this important strain. The 'resistance-disarmed' K. pneumoniae ST11 strain generated in this study will offer a more benign and readily genetically modifiable model organism for future extensive functional studies. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

MCR-1 and OXA-48 In Vivo Acquisition in KPC-Producing Escherichia coli after Colistin Treatment.

PubMed

Beyrouthy, Racha; Robin, Frederic; Lessene, Aude; Lacombat, Igor; Dortet, Laurent; Naas, Thierry; Ponties, Valérie; Bonnet, Richard

2017-08-01

The spread of mcr-1 -encoding plasmids into carbapenem-resistant Enterobacteriaceae raises concerns about the emergence of untreatable bacteria. We report the acquisition of mcr-1 in a carbapenem-resistant Escherichia coli strain after a 3-week course of colistin in a patient repatriated to France from Portugal. Whole-genome sequencing revealed that the Klebsiella pneumoniae carbapenemase-producing E. coli strain acquired two plasmids, an IncL OXA-48-encoding plasmid and an IncX4 mcr-1 -encoding plasmid. This is the first report of mcr-1 in carbapenemase-encoding bacteria in France. Copyright © 2017 American Society for Microbiology.

[Identification and Nitrogen Removal Characteristics of a Heterotrophic Nitrification-Aerobic Denitrification Strain Isolated from Marine Environment].

PubMed

Sun, Qing-hua; Yu, De-shuang; Zhang, Pei-yu; Lin, Xue-zheng; Li, Jin

2016-02-15

A heterotrophic nitrification-aerobic denitrification strain named y5 was isolated from marine environment by traditional microbial isolation method using seawater as medium. It was identified as Klebsiella sp. based on the morphological, physiological and 16S rRNA sequence analysis. The experiment results showed that the optimal carbon resource was sodium citrate; the optimal pH was 7.0; and the optimal C/N was 17. The strain could use NH4Cl, NaNO2 and KNO3 as sole nitrogen source, and the removal efficiencies were77.07%, 64.14% and 100% after 36 hours, respectively. The removal efficiency reached 100% after 36 hours in the coexistence of NH4Cl, NaNO2 and KNO3. The results showed that the strain y5 had independent and efficient heterotrophic nitrification and aerobic denitrification activities in high salt wastewater.

Oral versus intravenous antibiotics for patients with Klebsiella pneumoniae liver abscess: study protocol for a randomized controlled trial.

PubMed

Molton, James; Phillips, Rachel; Gandhi, Mihir; Yoong, Joanne; Lye, David; Tan, Thuan Tong; Fisher, Dale; Archuleta, Sophia

2013-10-31

Klebsiella pneumoniae liver abscess is the most common etiology of liver abscess in Singapore and much of Asia, and its incidence is increasing. Current management includes prolonged intravenous antibiotic therapy, but there is limited evidence to guide oral conversion. The implicated K1/K2 capsule strain of Klebsiella pneumoniae is almost universally susceptible to ciprofloxacin, an antibiotic with high oral bioavailability. Our primary aim is to compare the efficacy of early (< one week) step-down to oral antibiotics, to continuing four weeks of intravenous antibiotics, in patients with Klebsiella liver abscess. The study is designed as a multi-center randomized open-label active comparator-controlled non-inferiority trial, with a non-inferiority margin of 12%. Eligible participants will be inpatients over the age of 21 with a CT or ultrasound scan suggestive of a liver abscess, and Klebsiella pneumoniae isolated from abscess fluid or blood. Randomization into intervention or active control arms will be performed with a 1:1 allocation ratio. Participants randomized to active control will receive IV ceftriaxone 2 grams daily to complete a total of four weeks of IV antibiotics. Participants randomized to intervention will be immediately converted to oral ciprofloxacin 750 mg twice daily. At Week four, all participants will undergo abdominal imaging and be assessed for clinical response (CRP < 20 mg/l, absence of fever, plus scan showing that the maximal diameter of the abscess has reduced). If criteria are met, antibiotics are stopped; if not, oral antibiotics are continued, with reassessment for clinical response fortnightly. If criteria for clinical response are met by Week 12, the primary endpoint of clinical cure is met. A cost analysis will be performed to assess the cost saving of early conversion to oral antibiotics, and a quality of life analysis will be performed to assess whether treatment with oral antibiotics is less burdensome than prolonged IV antibiotics. Our results would help inform local and international practice guidelines regarding the optimal antibiotic management of Klebsiella liver abscess. A finding of non-inferiority may translate to the wider adoption of a more cost-effective strategy that reduces hospital length of stay and improves patient-centered outcomes and satisfaction. Clinical trials gov NCT01723150.

[Aspects of the antimicrobial resistence profile in infections with Escherichia coli and Klebsiella pneumoniae in diabetic patients].

PubMed

Petrovici, Cristina G; Dorobăţ, Carmen; Matei, Mioara; Teodor, Andra; Luca, V; Miftode, Egidia

2011-01-01

Infections in diabetic patient remains an important cause of morbidity and mortality, triggering and maintaining a prolonged metabolic imbalance. Emergence of extented spectrum beta-lactmase (ESBL) in Escherichia coli and Klebsiella pneumoniae is a major concern, because of the atypical manner infection acts in this group of imunodepressed patients and also for the limited therapeutic solutions. For this reason we have evaluated the profile of antimicrobial resistance of these pathogens in both diabetic and non diabetic patients. The aim of this study was to evaluate, in a retrospective case control study, the antibiotic susceptibility pattern in isolates of E. coli and Klebsiella spp. from different biological products in 49 diabetics and 150 non-diabetics admitted in The Clinical Hospital of Infectious Diseases Iaşi over a period of two years. Most of strains of E. coli and Klebsiella spp. ESBL positive were found in uroculture. Significant differences in E. coli resistance rate between diabetics and nondiabetics were noted for amoxicillin-clavulanic acid and ciprofloxacin (31,4% vs.13,98%, p=0,04, respectively 52,9% vs. 24,46%, p=0,004). More isolates of ESBL positive K. pneumoniae were found in diabetic patients (50% vs. 24%). Ciprofloxacin resistance of K. pneumoniae was significantly higher in diabetics (75% vs 39%; p=0,05). There was no resistance in E. coli and K. pneumoniae isolates to imipenem in the diabetic group. The high resistance rate to quinolones and 3rd generation cefalosporins limits their use for the treatment of Escherichia coli and K. pneumoniae infections. Other alternatives for empiric therapy in community and nosocomial-acquired infections in diabetic patient remains carbapenems, aminoglycosides and colimycin.

Global survey of Klebsiella pneumoniae major porins from ertapenem non-susceptible isolates lacking carbapenemases.

PubMed

Wise, Mark G; Horvath, Elizabeth; Young, Katherine; Sahm, Daniel F; Kazmierczak, Krystyna M

2018-03-01

To understand the diversity of porin disruption in Klebsiella pneumoniae, the major outer membrane protein (OMP) porins, OmpK35 and OmpK36, were examined in a set of isolates that did not harbour traditional carbapenem-hydrolysing enzymes, but nevertheless tested non-susceptible to ertapenem. A world-wide collection of Klebsiella pneumoniae isolates that were part of the Study for Monitoring Antimicrobial Resistance Trends (SMART) surveillance project over the years 2008-2014 were characterised with regard to their β-lactamase gene carriage and potential permeability defects. Four hundred and eighty-seven isolates that did not carry carbapenemase genes, but were non-susceptible to ertapenem, were investigated by sequence analysis of the genes encoding OmpK35 and OmpK36. Isolates without obvious genetic lesions in either major porin gene were further examined by outer membrane protein SDS-PAGE. The majority of isolates, 83.0 % (404/487), exhibited clear genetic disruption in either or both of the ompK35 and ompK36 genes. Among the proportion of the collection with the highest ertapenem MIC value (>4 mg l -1 ), 60.5 % (115/190) showed mutation in both porin genes. Isolates without obvious genetic mutations were examined by SDS-PAGE, and 90.4 % (75/83) were found to lack or show altered expression of at least one of the major OMPs when compared to an ertapenem sensitive control strain. This study illustrates that porin deficiency in Klebsiella pneumoniae is a widespread phenomenon, and in combination with ESBLs and/or AmpC enzymes, likely accounts for the elevated ertapenem MICs observed in this study.

Kaptive Web: User-Friendly Capsule and Lipopolysaccharide Serotype Prediction for Klebsiella Genomes.

PubMed

Wick, Ryan R; Heinz, Eva; Holt, Kathryn E; Wyres, Kelly L

2018-06-01

As whole-genome sequencing becomes an established component of the microbiologist's toolbox, it is imperative that researchers, clinical microbiologists, and public health professionals have access to genomic analysis tools for the rapid extraction of epidemiologically and clinically relevant information. For the Gram-negative hospital pathogens such as Klebsiella pneumoniae , initial efforts have focused on the detection and surveillance of antimicrobial resistance genes and clones. However, with the resurgence of interest in alternative infection control strategies targeting Klebsiella surface polysaccharides, the ability to extract information about these antigens is increasingly important. Here we present Kaptive Web, an online tool for the rapid typing of Klebsiella K and O loci, which encode the polysaccharide capsule and lipopolysaccharide O antigen, respectively. Kaptive Web enables users to upload and analyze genome assemblies in a web browser. The results can be downloaded in tabular format or explored in detail via the graphical interface, making it accessible for users at all levels of computational expertise. We demonstrate Kaptive Web's utility by analyzing >500 K. pneumoniae genomes. We identify extensive K and O locus diversity among 201 genomes belonging to the carbapenemase-associated clonal group 258 (25 K and 6 O loci). The characterization of a further 309 genomes indicated that such diversity is common among the multidrug-resistant clones and that these loci represent useful epidemiological markers for strain subtyping. These findings reinforce the need for rapid, reliable, and accessible typing methods such as Kaptive Web. Kaptive Web is available for use at http://kaptive.holtlab.net/, and the source code is available at https://github.com/kelwyres/Kaptive-Web. Copyright © 2018 Wick et al.

Characterising the biology of novel lytic bacteriophages infecting multidrug resistant Klebsiella pneumoniae.

PubMed

Kęsik-Szeloch, Agata; Drulis-Kawa, Zuzanna; Weber-Dąbrowska, Beata; Kassner, Jerzy; Majkowska-Skrobek, Grażyna; Augustyniak, Daria; Lusiak-Szelachowska, Marzanna; Zaczek, Maciej; Górski, Andrzej; Kropinski, Andrew M

2013-03-28

Members of the genus Klebsiella are among the leading microbial pathogens associated with nosocomial infection. The increased incidence of antimicrobial resistance in these species has propelled the need for alternate/combination therapeutic regimens to aid clinical treatment. Bacteriophage therapy forms one of these alternate strategies. Electron microscopy, burst size, host range, sensitivity of phage particles to temperature, chloroform, pH, and restriction digestion of phage DNA were used to characterize Klebsiella phages. Of the 32 isolated phages eight belonged to the family Myoviridae, eight to the Siphoviridae whilst the remaining 16 belonged to the Podoviridae. The host range of these phages was characterised against 254 clinical Enterobacteriaceae strains including multidrug resistant Klebsiella isolates producing extended-spectrum beta-lactamases (ESBLs). Based on their lytic potential, six of the phages were further characterised for burst size, physicochemical properties and sensitivity to restriction endonuclease digestion. In addition, five were fully sequenced. Multiple phage-encoded host resistance mechanisms were identified. The Siphoviridae phage genomes (KP16 and KP36) contained low numbers of host restriction sites similar to the strategy found in T7-like phages (KP32). In addition, phage KP36 encoded its own DNA adenine methyltransferase. The φKMV-like KP34 phage was sensitive to all endonucleases used in this study. Dam methylation of KP34 DNA was detected although this was in the absence of an identifiable phage encoded methyltransferase. The Myoviridae phages KP15 and KP27 both carried Dam and Dcm methyltransferase genes and other anti-restriction mechanisms elucidated in previous studies. No other anti-restriction mechanisms were found, e.g. atypical nucleotides (hmC or glucosyl hmC), although Myoviridae phage KP27 encodes an unknown anti-restriction mechanism that needs further investigation.

High Prevalence of ESBL-Producing Klebsiella pneumoniae Causing Community-Onset Infections in China

PubMed Central

Zhang, Jing; Zhou, Kai; Zheng, Beiwen; Zhao, Lina; Shen, Ping; Ji, Jinru; Wei, Zeqing; Li, Lanjuan; Zhou, Jianying; Xiao, Yonghong

2016-01-01

The aim of this work was to investigate the epidemiological and genetic characteristics of ESBL-producing Klebsiella pneumoniae (ESBL-Kp) causing community-onset infections. K. pneumoniae isolates were collected from 31 Chinese secondary hospitals between August 2010 and 2011. Genes encoding ESBL and AmpC beta-lactamases were detected by PCR. The isolates were assigned to sequence types (STs) using multi-locus sequence typing (MLST). Eleven ESBL-Kp strains were selected for whole-genome sequencing (WGS) for investigating the genetic environment and plasmids encoding ESBL genes. A total of 578 K. pneumoniae isolates were collected, and 184 (31.8%) carried ESBL genes. The prevalence of ESBL-Kp varied from different geographical areas of China (10.2–50.3%). The three most prevalent ESBL genes were blaCTX-M-14 (n = 74), blaCTX-M-15 (n = 60), and blaCTX-M-3 (n = 40). MLST assigned 127 CTX-M-14 and CTX-M-15 producers to 54 STs, and CC17 was the most prevalent population (12.6%). STs (23, 37, and 86) that were known frequently associated with hypervirulent K. pneumoniae (hvKP) account for 14.1% (18/127). Phylogenetic analysis by concatenating the seven loci of MLST revealed the existence of ESBL-producing K. quasipneumoniae (two strains) and K. varricola (one strain), which was further confirmed by WGS. This study highlights the challenge of community-onset infections caused by ESBL-Kp in China. The prevalence of STs frequently associating with hvKP should be of concern. Surveillance of ESBL-KP causing community-onset infections now appears imperative. PMID:27895637

Biodegradation of hexahydro-1,3,5-trinitro-1,3,5-triazine and its mononitroso derivative hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine by Klebsiella pneumoniae strain SCZ-1 isolated from an anaerobic sludge.

PubMed

Zhao, Jian-Shen; Halasz, Annamaria; Paquet, Louise; Beaulieu, Chantale; Hawari, Jalal

2002-11-01

In previous work, we found that an anaerobic sludge efficiently degraded hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), but the role of isolates in the degradation process was unknown. Recently, we isolated a facultatively anaerobic bacterium, identified as Klebsiella pneumoniae strain SCZ-1, using MIDI and the 16S rRNA method from this sludge and employed it to degrade RDX. Strain SCZ-1 degraded RDX to formaldehyde (HCHO), methanol (CH3OH) (12% of total C), carbon dioxide (CO(2)) (72% of total C), and nitrous oxide (N2O) (60% of total N) through intermediary formation of methylenedinitramine (O(2)NNHCH(2)NHNO(2)). Likewise, hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX) was degraded to HCHO, CH3OH, and N2O (16.5%) with a removal rate (0.39 micromol. h(-1). g [dry weight] of cells(-1)) similar to that of RDX (0.41 micromol. h(-1). g [dry weight] of cells(-1)) (biomass, 0.91 g [dry weight] of cells. liter(-1)). These findings suggested the possible involvement of a common initial reaction, possibly denitration, followed by ring cleavage and decomposition in water. The trace amounts of MNX detected during RDX degradation and the trace amounts of hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine detected during MNX degradation suggested that another minor degradation pathway was also present that reduced -NO2 groups to the corresponding -NO groups.

Immunological Relationship of Different Preparations of Coliform Enterotoxins

PubMed Central

Klipstein, Frederick A.; Engert, Richard F.

1978-01-01

Antisera raised in rabbits to ultrafiltrate toxin preparations containing either the heat-labile (LT) toxin form obtained from whole cell lysates or broth filtrates or the heat-stable (ST) toxin form prepared from broth filtrates from nontoxigenic and toxigenic strains of Escherichia coli and Klebsiella were examined for their ability to neutralize the secretory effect on water transport of these toxins in the rat jejunum as determined by the in vivo marker perfusion technique. Antisera to the heat-labile toxin derived from whole cell lysate preparations from nontoxigenic strains had no neutralizing effect. Antisera to both types of LT preparation from both toxigenic strains neutralized, with several exceptions, all of the homologous and heterologous LT toxins as well as a heat-labile toxin preparation derived from sequential ultrafiltration of cell-free whole cell lysates which had a defined molecular weight of between 30,000 and 100,000. These antisera also neutralized homologous and heterologous ST preparations obtained from broth filtrates, but they had no neutraliziṅg effect on low-molecular-weight, ST toxin material obtained during the sequential ultrafiltration of cell lysates. Antisera to ST prepared from broth filtrates had no neutralizing capacity against either LT or ST toxin preparations. These observations (i) indicate that the immunological relationship of E. coli and Klebsiella LT and ST toxins extends to antisera raised against LT prepared by several different methods, (ii) raise the possibility that, based on the response to antisera to LT, there may be several immunologically heterogeneous forms of low-molecular-weight ST toxin, and (c) confirm the lack of immunogenicity of ST. PMID:361578

Seasonal and ascending trends in the incidence of carriage of extended-spectrum ß-lactamase-producing Escherichia coli and Klebsiella species in 2 German hospitals.

PubMed

Kaier, Klaus; Frank, Uwe; Conrad, Andreas; Meyer, Elisabeth

2010-11-01

Extended-spectrum ß-lactamase (ESBL)-producing strains of bacteria have become a major public health concern. In the present study, the incidence of carriage of ESBL-producing strains was analyzed for general trends and seasonality. Monthly data on ESBL-producing strains were collected retrospectively at 2 large university hospitals in Germany. The mean monthly temperatures for the 2 settings were collected from Germany's national meteorological service. Multivariable time series analyses were performed to explain variations in the monthly incidence densities of carriage of ESBL-producing bacteria (number of cases involving ESBL-producing Escherichia coli and/or Klebsiella species per 1,000 patient days). For the final models, we incorporated variables for the ascending linear trends and other variables representing the mean monthly temperature. Our models demonstrated that there was an increasing trend in the incidences of carriage of ESBL-producing bacteria. In addition, the incidences of carriage of all ESBL-producing bacteria responded positively to the mean temperature, meaning that during the summer, more cases involving ESBL-producing bacteria were detected than during the winter. The same methodology was also applied to the incidence of methicillin-resistant Staphylococcus aureus carriage, but no association was found with the mean temperature. In the present study, we demonstrated that the monthly incidence of carriage of ESBL-producing bacteria was highly correlated with the mean monthly temperature, a fact that should be considered in experimental studies as an additional parameter influencing the incidence of ESBL-producing bacteria.

Draft Genome Sequences of Pseudomonas aeruginosa Isolates from Wounded Military Personnel.

PubMed

Arivett, Brock A; Ream, Dave C; Fiester, Steven E; Kidane, Destaalem; Actis, Luis A

2016-08-11

Pseudomonas aeruginosa, a Gram-negative bacterium that causes severe hospital-acquired infections, is grouped as an ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogen because of its extensive drug resistance phenotypes and effects on human health worldwide. Five multidrug resistant P. aeruginosa strains isolated from wounded military personnel were sequenced and annotated in this work. Copyright © 2016 Arivett et al.

Draft Genome Sequences of Acinetobacter baumannii Isolates from Wounded Military Personnel.

PubMed

Arivett, Brock A; Ream, Dave C; Fiester, Steven E; Kidane, Destaalem; Actis, Luis A

2016-08-25

Acinetobacter baumannii is a Gram-negative bacterium capable of causing hospital-acquired infections that has been grouped with Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species as ESKAPE pathogens because of their extensive drug resistance phenotypes and increasing risk to human health. Twenty-four multidrug-resistant A. baumannii strains isolated from wounded military personnel were sequenced and annotated. Copyright © 2016 Arivett et al.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tew, Karen

I spent the last ten weeks working in the Systems Biology department at Sandia National Laboratories in Livermore, CA. Under the direction of Zachary Bent, I helped do preliminary testing/optimization of a vacuum-driven, capture-based system for pathogen RNA transcript enrichment. I also worked on a project to create mutant Yersinia enterocolitica strains in order to test which genes are involved in intracellular pathogen virulence, as well as sequencing several Klebsiella pneumoniae samples for use by a bioinformaticist.

Antimicrobial activities of three species of family mimosaceae.

PubMed

Mahmood, Adeel; Mahmood, Aqeel; Qureshi, Rizwana Aleem

2012-01-01

The antimicrobial activities of crude methanolic extract of leaves of Acacia nilotica L., Albizia lebbeck L. and Mimosa himalayana Gamble belonging to family mimosaceae were investigated in this research work. Antibacterial activity was studied by agar well diffusion method against one gram-positive Bacillus subtilis and three gram-negative Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumonia. Crude extract of all plants showed best activity against gram-negative bacterial strains while minor inhibition zones were found against gram positive bacterial strains. Antifungal activity of crude plant extract was screened by agar tube dilution method against Aspergillus nigar and Aspergillus flavus. These results showed that these plants extracts have potential against bacterias, while against fungi their activity is not much effective.

Multidrug-resistant organisms in military wounds from Iraq and Afghanistan.

PubMed

Calhoun, Jason H; Murray, Clinton K; Manring, M M

2008-06-01

Mortality from battlefield wounds has historically declined, thanks to better surgical management, faster transport of casualties, and improved antibiotics. Today, one of the major challenges facing U.S. military caregivers is the presence of multidrug-resistant organisms in orthopaedic extremity wounds. The most frequently identified resistant strains of bacteria are Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter calcoaceticus-baumannii complex. Overuse of broad-spectrum antibiotics may be an important factor in building resistant strains. Acinetobacter infections appear to hospital-acquired and not from an initial colonization of the injury. More research is required to give military physicians the tools they require to reduce the infection rate and defeat multidrug-resistant organisms.

[Clinical studies on flomoxef in respiratory tract infections].

PubMed

Kanegae, H; Yamada, H; Yamaguchi, T; Kuroki, S; Katoh, O

1987-10-01

Flomoxef (FMOX, 6315-S) is a new oxacephem with a broad spectrum of antimicrobial activity. We used FMOX for treatment of 13 patients with respiratory tract infections including 4 cases of pneumonia, 5 of lung abscess and 4 of exacerbation of the chronic airway diseases. FMOX showed excellent in vitro antimicrobial activities against clinical isolates including 4 strains of Streptococcus pneumoniae, 2 strains of Haemophilus influenzae and each one strain of Escherichia coli and Klebsiella pneumoniae. Clinical responses were excellent in 3 cases, good in 7 and fair or poor in 3. No side effect was observed, but abnormal laboratory findings caused by FMOX administration were found in 2 cases; hypertransaminasemia and eosinophilia. However, neither of them was severe. From the above results, it is considered that FMOX will be useful for treatment of patients with respiratory tract infections.

Novel consortium of Klebsiella variicola and Lactobacillus species enhances the functional potential of fermented dairy products by increasing the availability of branched-chain amino acids and the amount of distinctive volatiles.

PubMed

Rosales-Bravo, H; Morales-Torres, H C; Vázquez-Martínez, J; Molina-Torres, J; Olalde-Portugal, V; Partida-Martínez, L P

2017-11-01

Identify novel bacterial taxa that could increase the availability of branched-chain amino acids and the amount of distinctive volatiles during skim milk fermentation. We recovered 344 bacterial isolates from stool samples of healthy and breastfed infants. Five were selected based on their ability to produce branched-chain amino acids. Three strains were identified as Escherichia coli, one as Klebsiella pneumoniae and other as Klebsiella variicola by molecular and biochemical methods. HPLC and solid-phase microextraction with GC-MS were used for the determination of free amino acids and volatile compounds respectively. The consortium formed by K. variicola and four Lactobacillus species showed the highest production of Leu and Ile in skim milk fermentation. In addition, the production of volatile compounds, such as acetoin, ethanol, 2-nonanone, and acetic, hexanoic and octanoic acids, increased in comparison to commercial yogurt, Emmental and Gouda cheese. Also, distinctive volatiles, such as 2,3-butanediol, 4-methyl-2- hexanone and octanol, were identified. The use of K. variicola in combination with probiotic Lactobacillus species enhances the availability of Leu and Ile and the amount of distinctive volatiles during skim milk fermentation. The identified consortium increases the functional potential of fermented dairy products. © 2017 The Society for Applied Microbiology.

INACTIVATION OF SOME SEMISYNTHETIC PENICILLINS BY GRAM-NEGATIVE BACILLI

PubMed Central

Sabath, Leon; Finland, Maxwell

1963-01-01

Sabath, Leon (Boston City Hospital, Boston, Mass.) and Maxwell Finland. Inactivation of some semisynthetic penicillins by gram-negative bacilli. J. Bacteriol. 85:314–321. 1963.—An agar diffusion method was used to test 55 strains of gram-negative bacilli for their ability to inactivate penicillin G, methicillin, biphenylpenicillin, oxacillin, and ampicillin; 26 strains inactivated one or more of them. All strains of Klebsiella-Aerobacter, nearly all of Escherichia coli, and some of Pseudomonas aeruginosa, but not those of Proteus or Salmonella, were active by this method. Penicillin G was inactivated by the largest number of strains, biphenylpenicillin and ampicillin by somewhat fewer, and oxacillin and methicillin by about half as many. When the five penicillins were incubated with four strains of different bacteria in broth at 37 C, all were inactivated to a considerable extent by all the strains, each penicillin to a different degree, but to about the same extent by all the strains. Adsorption alone did not account for the loss of activity. The results suggest that there are qualitative, as well as quantitative, differences among species or even strains of gram-negative bacilli in their ability to inactivate the various penicillins. Images PMID:13975857

Genome Sequence of a Multidrug-Resistant Strain of Klebsiella pneumoniae, BAMC 07-18, Isolated from a Combat Injury Wound

DTIC Science & Technology

2014-11-26

including azithromycin, ceftazidime, chloramphenicol, and tetracycline; however, BAMC 07-18 is sensitive to imipenem , a carbapenem, both in vivo and in...vitro (7). High doses of imipenem are still unable to completely clear biofilm infections, though it leads to significant reductions in viability and...alterations in morphology (7), leading us to question the genetic mechanisms of the pleiotropic effects of imipenem against this carbapenem-sensitive

Antimicrobial susceptibility and distribution of inhibition zone diameters of bovine mastitis pathogens in Flanders, Belgium.

PubMed

Supré, K; Lommelen, K; De Meulemeester, L

2014-07-16

In dairy farms, antimicrobial drugs are frequently used for treatment of (sub)clinical mastitis. Determining the antimicrobial susceptibility of mastitis pathogens is needed to come to a correct use of antimicrobials. Strains of Staphylococcus aureus (n=768), Streptococcus uberis (n=939), Streptococcus dysgalactiae (n=444), Escherichia coli (n=563), and Klebsiella species (n=59) originating from routine milk samples from (sub)clinical mastitis were subjected to the disk diffusion method. Disks contained representatives of frequently used antibiotics in dairy. A limited number of clinical breakpoints were available through CLSI, and showed that susceptibility of Staph. aureus, E. coli, and Klebsiella was moderate to high. For streptococcal species however, a large variation between the tested species and the different antimicrobials was observed. In a next step, wild type populations were described based on epidemiological cut off values (EUCAST). Because of the limited number of official cut off values, the data were observed as a mastitis subpopulation and self-generated cut off values were created and a putative wild type population was suggested. The need for accurate clinical breakpoints for veterinary pathogens is high. Despite the lack of these breakpoints, however, a population study can be performed based on the distribution of inhibition zone diameters on the condition that a large number of strains is tested. Copyright © 2014 Elsevier B.V. All rights reserved.

Phytochemistry and Preliminary Assessment of the Antibacterial Activity of Chloroform Extract of Amburana cearensis (Allemão) A.C. Sm. against Klebsiella pneumoniae Carbapenemase-Producing Strains

PubMed Central

Sá, Mirivaldo Barros; Ralph, Maria Taciana; Nascimento, Danielle Cristina Oliveira; Ramos, Clécio Souza; Barbosa, Isvânia Maria Serafin; Sá, Fabrício Bezerra; Lima-Filho, J. V.

2014-01-01

The chloroform extract of the stem bark of Amburana cearensis was chemically characterized and tested for antibacterial activity.The extract was analyzed by gas chromatography and mass spectrometry. The main compounds identified were 4-methoxy-3-methylphenol (76.7%), triciclene (3.9%), α-pinene (1.0%), β-pinene (2.2%), and 4-hydroxybenzoic acid (3.1%). Preliminary antibacterial tests were carried out against species of distinct morphophysiological characteristics: Escherichia coli, Salmonella enterica Serotype Typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus. The minimum inhibitory concentration (MIC) was determinate in 96-well microplates for the chloroform extract and an analogue of themain compound identified, which was purchased commercially.We have shown that plant's extract was only inhibitory (but not bactericidal) at the maximum concentration of 6900 μg/mL against Pseudomonas aeruginosa and Bacillus cereus. Conversely, the analogue 2-methoxy-4-methylphenol produced MICs ranging from215 to 431 μg/mL against all bacterial species.New antibacterial assays conducted with such chemical compound against Klebsiella pneumoniae carbapenemase-producing strains have shown similarMICresults and minimumbactericidal concentration (MBC) of 431 μg/mL.We conclude that A. cearensis is a good source of methoxy-methylphenol compounds,which could be screened for antibacterial activity againstmultiresistant bacteria fromdifferent species PMID:24772183

Genomic epidemiology of global Klebsiella pneumoniae carbapenemase (KPC)-producing Escherichia coli.

PubMed

Stoesser, N; Sheppard, A E; Peirano, G; Anson, L W; Pankhurst, L; Sebra, R; Phan, H T T; Kasarskis, A; Mathers, A J; Peto, T E A; Bradford, P; Motyl, M R; Walker, A S; Crook, D W; Pitout, J D

2017-07-19

The dissemination of carbapenem resistance in Escherichia coli has major implications for the management of common infections. bla KPC , encoding a transmissible carbapenemase (KPC), has historically largely been associated with Klebsiella pneumoniae, a predominant plasmid (pKpQIL), and a specific transposable element (Tn4401, ~10 kb). Here we characterize the genetic features of bla KPC emergence in global E. coli, 2008-2013, using both long- and short-read whole-genome sequencing. Amongst 43/45 successfully sequenced bla KPC -E. coli strains, we identified substantial strain diversity (n = 21 sequence types, 18% of annotated genes in the core genome); substantial plasmid diversity (≥9 replicon types); and substantial bla KPC -associated, mobile genetic element (MGE) diversity (50% not within complete Tn4401 elements). We also found evidence of inter-species, regional and international plasmid spread. In several cases bla KPC was found on high copy number, small Col-like plasmids, previously associated with horizontal transmission of resistance genes in the absence of antimicrobial selection pressures. E. coli is a common human pathogen, but also a commensal in multiple environmental and animal reservoirs, and easily transmissible. The association of bla KPC with a range of MGEs previously linked to the successful spread of widely endemic resistance mechanisms (e.g. bla TEM , bla CTX-M ) suggests that it may become similarly prevalent.

In vitro and in vivo antimicrobial activity of propolis on the microbiota from gastrointestinal tract of chickens.

PubMed

Kačániová, Miroslava; Rovná, Katarína; Arpášová, Henrieta; Cuboň, Juraj; Hleba, Lukáš; Pochop, Jaroslav; Kunová, Simona; Haščík, Peter

2012-01-01

The aim of this study was to examine the effect of propolis extracts on the microbial colonization of chicken gastrointestinal tract in vivo. The propolis was administered to both feed mixtures in various amounts except of the control group. The addition of 150 mg propolis to 1 kg of feed was included in the first experimental group, the addition of 450 mg.kg(-1) in the second experimental group, the addition of 600 mg.kg(-1) the third experimental group and 800 mg kg(-1) in the fourth one. The highest count of faecal enterococci was found in the third group (8.6 cfu.g(-1)) where 600 mg of propolis to 1 kg was added to the feed mixture. The highest count of lactobacilli was detected in the fourth experimental group (8.83 cfu.g(-1)) where was 800 mg of propolis added to 1 kg of feed mixture and number of Enterobacteriaceae genera count was found in control group (8.73 cfu.g(-1)). With RTQ PCR detected species from the genus Enterococcus were: E. avium, E. casseliflavus, E cecorum, E. faecalis, E. faecium, E. gallinarum, E. hirae and E. malodoratus and from genus Lactobacillus were: Lactobacillus crispatus, L. acidophilus and L. salivarius. With MALDI TOF MS Biotyper from Enterobacteriaceae genera were identified Citrobacter braakii, Raoultella ornithinolytica, Serratia fonticola, Escherichia coli and Klebsiella oxytoca. Antimicrobial activities In vitro of six species of bacteria isolated from gastrointestinal tract of chickens were also tested. The best antimicrobial effect of Citrobacter braakii on ethanolic propolis extract in all concentrations were found.

Microbiological and toxicological effects of Perla black bean (Phaseolus vulgaris L.) extracts: in vitro and in vivo studies.

PubMed

Lara-Díaz, Víctor Javier; Gaytán-Ramos, Angel A; Dávalos-Balderas, Alfredo José; Santos-Guzmán, Jesús; Mata-Cárdenas, Benito David; Vargas-Villarreal, Javier; Barbosa-Quintana, Alvaro; Sanson, Misu; López-Reyes, Alberto Gabriel; Moreno-Cuevas, Jorge E

2009-02-01

We investigated the microbiological and toxicological effects of three Perla black bean extracts on the growth and culture of selected pathogenic microorganisms, the toxicity over Vero cell lines and an in vivo rat model. Three different solvents were used to obtain Perla black bean extracts. All three Perla black bean extracts were tested for antibacterial and antiparasitic activity and further analysed for intrinsic cytotoxicity (IC(50)). Methanol Perla black bean extract was used for acute toxicity test in rats, with the up-and-down doping method. All Perla black bean extracts inhibited bacterial growth. Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella oxytoca, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis and Listeria monocytogenes showed inhibition, while Escherichia coli and Enterobacter aerogenes did not. Acidified water and acetic acid Perla black bean extract were tested in parasites. The best IC(50) was observed for Giardia lamblia, while higher concentrations were active against Entamoeba histolytica and Trichomonas vaginalis. The Vero cells toxicity levels (IC(50)) for methanol, acidified water and acetic acid Perla black bean extract were [mean +/- S.D. (95% CI)]: 275 +/- 6.2 (267.9-282.0), 390 +/- 4.6 (384.8-395.2) and 209 +/- 3.39 (205.6-212.4) microg/ml, respectively. In vivo acute toxicity assays did not show changes in absolute organ weights, gross and histological examinations of selected tissues or functional tests. The acetic acid and methanol Perla black bean extract proved to exhibit strong antibacterial activity and the acidified water Perla black bean extract exerted parasiticidal effects against Giardia lamblia, Entamoeba hystolitica and Trichomonas vaginalis. The three Perla black bean extracts assayed over Vero cells showed very low toxicity and the methanol Perla black bean extract in vivo did not cause toxicity.

Etiologic profile and antimicrobial susceptibility of community-acquired urinary tract infection in two Cameroonian towns

PubMed Central

2012-01-01

Background Urinary tract infection (UTI) represents one of the most common diseases encountered in community medical practice. In resource poor settings, treatment is usually empiric due to the high cost and long duration required for reporting diagnosis by culture and antibiotic susceptibility testing. With the growing problem of drug resistance knowledge of antibiotic susceptibility pattern is pertinent for successful eradication of invading pathogens. Our study, the first of its kind in Cameroon, analyzed the distribution and antibiotic susceptibility of bacteria causing community-acquired urinary tract infection (CAUTI) in two towns (Bamenda and Buea) with a large number of young and middle aged persons, to provide data that could guide empiric treatment. Findings We cultured 235 urine specimens and analyzed the antibiotic susceptibility of isolates by the disc diffusion technique. Uropathogens were recovered from 137 (58.3%), with prevalence rates in Buea and Bamenda being 65.9% and 54% respectively. Predominant pathogens were Escherichia coli (31.4%), Klebsiella oxytoca (25.5%) and Staphylococcus spp (24.1%). Geographic variation in uropathogen distribution and antibiotic susceptibility was observed, and a significant difference in pathogen distribution with respect to gender. The 20–39 years age group had the highest prevalence of infection. All pathogens isolated were detected in this group. Isolates exhibited low susceptibility to antibiotics tested. Bamenda isolates generally exhibited lower susceptibility compared to those from Buea. Conclusion Regional variation in etiology of CAUTI and antibiotic susceptibility observed in our study emphasizes the need to establish local and national antimicrobial resistance monitoring systems in Cameroon to provide information for the development of CAUTI treatment guidelines. PMID:22564344

Evaluation of the FilmArray Blood Culture Identification Panel: Results of a Multicenter Controlled Trial

PubMed Central

Salimnia, Hossein; Lephart, Paul R.; Schreckenberger, Paul; DesJarlais, Sharon M.; Johnson, J. Kristie; Robinson, Gwen; Carroll, Karen C.; Greer, Amy; Morgan, Margie; Chan, Raymond; Loeffelholz, Michael; Valencia-Shelton, Frances; Jenkins, Stephen; Schuetz, Audrey N.; Daly, Judy A.; Barney, Trenda; Hemmert, Andrew; Kanack, Kristen J.

2016-01-01

Sepsis is a major cause of morbidity, mortality, and increased medical expense. Rapid diagnosis improves outcomes and reduces costs. The FilmArray blood culture identification panel (BioFire Diagnostics LLC, Salt Lake City, UT), a highly multiplexed PCR assay, can identify 24 etiologic agents of sepsis (8 Gram-positive, 11 Gram-negative, and 5 yeast species) and three antimicrobial resistance genes (mecA, vanA/B, and blaKPC) from positive blood culture bottles. It provides results in about 1 h with 2 min for assay setup. We present the results of an eight-center trial comparing the sensitivity and specificity of the panel with those of the laboratories' standard phenotypic identification techniques, as well as with molecular methods used to distinguish Acinetobacter baumannii from other members of the A. calcoaceticus-A. baumannii complex and to detect antimicrobial resistance genes. Testing included 2,207 positive aerobic blood culture samples, 1,568 clinical and 639 seeded. Samples were tested fresh or were frozen for later testing within 8 h after the bottles were flagged as positive by an automated blood culture system. At least one organism was detected by the panel in 1,382 (88.1%) of the positive clinical specimens. The others contained primarily off-panel organisms. The panel reported multiple organisms in 81 (5.86%) positive clinical specimens. The unresolved blood culture identification sensitivity for all target detections exceeded 96%, except for Klebsiella oxytoca (92.2%), which achieved 98.3% sensitivity after resolution of an unavoidable phenotypic error. The sensitivity and specificity for vanA/B and blaKPC were 100%; those for mecA were 98.4 and 98.3%, respectively. PMID:26739158

Characterization of Escherichia coli and other Enterobacteriaceae in producer-distributor bulk milk.

PubMed

Ntuli, V; Njage, P M K; Buys, E M

2016-12-01

The current study was undertaken to characterize Escherichia coli and other Enterobacteriaceae in raw and pasteurized producer-distributor bulk milk (PDBM). A total of 258 samples were collected from purchase points in 8 provinces in South Africa. The samples were tested for antibiotic residues, phosphatase, total aerobic bacteria, coliforms, and E. coli counts. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used for identification of isolates. Escherichia coli isolates were characterized for virulence factors, antimicrobial resistance, serotypes, and presumptive E. coli O157:H7. Antibiotic residues and alkaline phosphatase were detected in 2% of both raw and pasteurized PDBM (n=258) and 21% pasteurized PDBM (n=104) samples, respectively. A total of 729 isolates belonging to 21 genera and 59 species were identified. Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, and Raoultella ornithinolytica were the most abundant species. Spoilage Enterobacteriaceae species exceeded 50% of the total isolates. Escherichia coli was detected and isolated from 36% of the milk samples. Thirty-one E. coli isolates harbored virulence genes stx1/stx2 and 38% (n=121) were presumptive O157:H7. The prevalence of samples with presumptive shigatoxin producing E. coli was 10%. Antimicrobial-resistant E. coli isolates were detected in 70% of the milk samples with 36% of stx1/stx2 positive E. coli showing multi-drug resistance. Information obtained from the study will be used for modeling the public health risk posed by milkborne pathogens in PDBM, which in many cases is consumed by poor and vulnerable members of the population. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Multidrug-Resistant Bacteria Isolated from Surface Water in Bassaseachic Falls National Park, Mexico

PubMed Central

Delgado-Gardea, Ma. Carmen E.; Tamez-Guerra, Patricia; Gomez-Flores, Ricardo; Zavala-Díaz de la Serna, Francisco Javier; Eroza-de la Vega, Gilberto; Nevárez-Moorillón, Guadalupe Virginia; Pérez-Recoder, María Concepción; Sánchez-Ramírez, Blanca; González-Horta, María del Carmen; Infante-Ramírez, Rocío

2016-01-01

Bacterial pathogens are a leading cause of waterborne disease, and may result in gastrointestinal outbreaks worldwide. Inhabitants of the Bassaseachic Falls National Park in Chihuahua, Mexico show seasonal gastroenteritis problems. This aim of this study was to detect enteropathogenic microorganisms responsible for diarrheal outbreaks in this area. In 2013, 49 surface water samples from 13 selected sampling sites along the Basaseachi waterfall and its main rivers, were collected during the spring, summer, autumn, and winter seasons. Fecal and total coliform counts were determined using standard methods; the AutoScan-4 system was used for identification of isolates and the antibiotic resistance profile by challenging each organism using 21 antibiotics. Significant differences among seasons were detected, where autumn samples resulted in the highest total (p < 0.05) and fecal (p < 0.001) coliform counts, whereas the lowest total coliform counts were recorded in spring. Significant differences between sampling sites were observed, where samples from sites 6, 8, and 11 had the highest total coliform counts (p < 0.009), whereas samples from site 9 exhibited the lowest one. From the microbiological analysis, 33 bacterial isolates from 13 different sites and four sampling seasons were selected; 53% of isolates were resistant to at least one antibiotic, and 15% exhibited a multidrug resistance (MDB) phenotype. MDB were identified as Klebsiella oxytoca (two out of four identified isolates), Escherichia coli (2/7), and Enterobacter cloacae (1/3). In addition, some water-borne microorganisms exhibited resistance to cefazoline, cefuroxime, ampicillin, and ampicillin-sulbactam. The presence of these microorganisms near rural settlements suggests that wastewater is the contamination source, providing one possible transmission mechanism for diarrheal outbreaks. PMID:27322297

Multidrug-Resistant Bacteria Isolated from Surface Water in Bassaseachic Falls National Park, Mexico.

PubMed

Delgado-Gardea, Ma Carmen E; Tamez-Guerra, Patricia; Gomez-Flores, Ricardo; Zavala-Díaz de la Serna, Francisco Javier; Eroza-de la Vega, Gilberto; Nevárez-Moorillón, Guadalupe Virginia; Pérez-Recoder, María Concepción; Sánchez-Ramírez, Blanca; González-Horta, María Del Carmen; Infante-Ramírez, Rocío

2016-06-16

Bacterial pathogens are a leading cause of waterborne disease, and may result in gastrointestinal outbreaks worldwide. Inhabitants of the Bassaseachic Falls National Park in Chihuahua, Mexico show seasonal gastroenteritis problems. This aim of this study was to detect enteropathogenic microorganisms responsible for diarrheal outbreaks in this area. In 2013, 49 surface water samples from 13 selected sampling sites along the Basaseachi waterfall and its main rivers, were collected during the spring, summer, autumn, and winter seasons. Fecal and total coliform counts were determined using standard methods; the AutoScan-4 system was used for identification of isolates and the antibiotic resistance profile by challenging each organism using 21 antibiotics. Significant differences among seasons were detected, where autumn samples resulted in the highest total (p < 0.05) and fecal (p < 0.001) coliform counts, whereas the lowest total coliform counts were recorded in spring. Significant differences between sampling sites were observed, where samples from sites 6, 8, and 11 had the highest total coliform counts (p < 0.009), whereas samples from site 9 exhibited the lowest one. From the microbiological analysis, 33 bacterial isolates from 13 different sites and four sampling seasons were selected; 53% of isolates were resistant to at least one antibiotic, and 15% exhibited a multidrug resistance (MDB) phenotype. MDB were identified as Klebsiella oxytoca (two out of four identified isolates), Escherichia coli (2/7), and Enterobacter cloacae (1/3). In addition, some water-borne microorganisms exhibited resistance to cefazoline, cefuroxime, ampicillin, and ampicillin-sulbactam. The presence of these microorganisms near rural settlements suggests that wastewater is the contamination source, providing one possible transmission mechanism for diarrheal outbreaks.

Pathogen Distribution and Antimicrobial Resistance Among Pediatric Healthcare-Associated Infections Reported to the National Healthcare Safety Network, 2011-2014.

PubMed

Lake, Jason G; Weiner, Lindsey M; Milstone, Aaron M; Saiman, Lisa; Magill, Shelley S; See, Isaac

2018-01-01

OBJECTIVE To describe pathogen distribution and antimicrobial resistance patterns for healthcare-associated infections (HAIs) reported to the National Healthcare Safety Network (NHSN) from pediatric locations during 2011-2014. METHODS Device-associated infection data were analyzed for central line-associated bloodstream infection (CLABSI), catheter-associated urinary tract infections (CAUTI), ventilator-associated pneumonia (VAP), and surgical site infection (SSI). Pooled mean percentage resistance was calculated for a variety of pathogen-antimicrobial resistance pattern combinations and was stratified by location for device-associated infections (neonatal intensive care units [NICUs], pediatric intensive care units [PICUs], pediatric oncology and pediatric wards) and by surgery type for SSIs. RESULTS From 2011 to 2014, 1,003 hospitals reported 20,390 pediatric HAIs and 22,323 associated pathogens to the NHSN. Among all HAIs, the following pathogens accounted for more than 60% of those reported: Staphylococcus aureus (17%), coagulase-negative staphylococci (17%), Escherichia coli (11%), Klebsiella pneumoniae and/or oxytoca (9%), and Enterococcus faecalis (8%). Among device-associated infections, resistance was generally lower in NICUs than in other locations. For several pathogens, resistance was greater in pediatric wards than in PICUs. The proportion of organisms resistant to carbapenems was low overall but reached approximately 20% for Pseudomonas aeruginosa from CLABSIs and CAUTIs in some locations. Among SSIs, antimicrobial resistance patterns were similar across surgical procedure types for most pathogens. CONCLUSION This report is the first pediatric-specific description of antimicrobial resistance data reported to the NHSN. Reporting of pediatric-specific HAIs and antimicrobial resistance data will help identify priority targets for infection control and antimicrobial stewardship activities in facilities that provide care for children. Infect Control Hosp Epidemiol 2018;39:1-11.

Identification of Enterobacteriaceae by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using the VITEK MS system.

PubMed

Richter, S S; Sercia, L; Branda, J A; Burnham, C-A D; Bythrow, M; Ferraro, M J; Garner, O B; Ginocchio, C C; Jennemann, R; Lewinski, M A; Manji, R; Mochon, A B; Rychert, J A; Westblade, L F; Procop, G W

2013-12-01

This multicenter study evaluated the accuracy of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry identifications from the VITEK MS system (bioMérieux, Marcy l'Etoile, France) for Enterobacteriaceae typically encountered in the clinical laboratory. Enterobacteriaceae isolates (n = 965) representing 17 genera and 40 species were analyzed on the VITEK MS system (database v2.0), in accordance with the manufacturer's instructions. Colony growth (≤72 h) was applied directly to the target slide. Matrix solution (α-cyano-4-hydroxycinnamic acid) was added and allowed to dry before mass spectrometry analysis. On the basis of the confidence level, the VITEK MS system provided a species, genus only, or no identification for each isolate. The accuracy of the mass spectrometric identification was compared to 16S rRNA gene sequencing performed at MIDI Labs (Newark, DE). Supplemental phenotypic testing was performed at bioMérieux when necessary. The VITEK MS result agreed with the reference method identification for 96.7% of the 965 isolates tested, with 83.8% correct to the species level and 12.8% limited to a genus-level identification. There was no identification for 1.7% of the isolates. The VITEK MS system misidentified 7 isolates (0.7 %) as different genera. Three Pantoea agglomerans isolates were misidentified as Enterobacter spp. and single isolates of Enterobacter cancerogenus, Escherichia hermannii, Hafnia alvei, and Raoultella ornithinolytica were misidentified as Klebsiella oxytoca, Citrobacter koseri, Obesumbacterium proteus, and Enterobacter aerogenes, respectively. Eight isolates (0.8 %) were misidentified as a different species in the correct genus. The VITEK MS system provides reliable mass spectrometric identifications for Enterobacteriaceae.

Characterization of bacterial coliform occurrences in different zones of a drinking water distribution system.

PubMed

Blanch, A R; Galofré, B; Lucena, F; Terradillos, A; Vilanova, X; Ribas, F

2007-03-01

To compare the bacterial coliforms detected from occurrences in three zones of a water distribution system supplied by two separate water sources. Conventional and standardized protocols for identifying enterobacterial populations were applied. Additional tests to confirm isolates were included. Analyses of diversity and population similarity were performed using the Phene Plate System, a miniaturized biochemical phenotyping method. Isolates were identified by the API 20E system in tandem with biochemical phenotyping. A total of 16 576 samples were taken from the water distribution system, with 1416 isolates analysed. A low number of coliform occurrences were observed (2%). Escherichia coli was not detected in either water origin or in Zone 2 samples; however, in Zones 1 and 3 a low number of cases of E. coli were recorded. The percentages of E. coli depended on the identification criteria. Eight biochemical profiles for coliform populations were defined according to the results of the confirmative tests. There was a high diversity among these populations in the three zones studied, although no significant variations in their composition (associated with occurrences in the different zones) were observed. Klebsiella oxytoca was the most commonly detected species irrespective of zone, although seven other enterobacterial genera were also found. Analysis of the enzymatic activity of beta-glucuronidase or application of the criteria established in the norm ISO 9308-1, in tandem with thermotolerance was needed to evaluate the occurrence of E. coli in the distribution systems. Detected occurrences of bacterial coliforms could be associated with re-growth patterns for specific sampling points in the distribution system. Seasonal differences, independent of the studied zones, were observed. Biochemical phenotyping of bacterial coliforms was shown to be a useful method on the characterization of occurrences in water distribution systems.

Characterising health care-associated bloodstream infections in public hospitals in Queensland, 2008-2012.

PubMed

Si, Damin; Runnegar, Naomi; Marquess, John; Rajmokan, Mohana; Playford, Elliott G

2016-04-18

To describe the epidemiology and rates of all health care-associated bloodstream infections (HA-BSIs) and of specific HA-BSI subsets in public hospitals in Queensland. Standardised HA-BSI surveillance data were collected in 23 Queensland public hospitals, 2008-2012. HA-BSIs were prospectively classified in terms of place of acquisition (inpatient, non-inpatient); focus of infection (intravascular catheter-associated, organ site focus, neutropenic sepsis, or unknown focus); and causative organisms. Inpatient HA-BSI rates (per 10,000 patient-days) were calculated. There were 8092 HA-BSIs and 9418 causative organisms reported. Inpatient HA-BSIs accounted for 79% of all cases. The focus of infection in 2792 cases (35%) was an organ site, intravascular catheters in 2755 (34%; including 2240 central line catheters), neutropenic sepsis in 1063 (13%), and unknown in 1482 (18%). Five per cent (117 of 2240) of central line-associated BSIs (CLABSIs) were attributable to intensive care units (ICUs). Eight groups of organisms provided 79% of causative agents: coagulase-negative staphylococci (18%), Staphylococcus aureus (15%), Escherichia coli (11%), Pseudomonas species (9%), Klebsiella pneumoniae/oxytoca (8%), Enterococcus species (7%), Enterobacter species (6%), and Candida species (5%). The overall inpatient HA-BSI rate was 6.0 per 10,000 patient-days. The rates for important BSI subsets included: intravascular catheter-associated BSIs, 1.9 per 10,000 patient-days; S. aureus BSIs, 1.0 per 10,000 patient-days; and methicillin-resistant S. aureus BSIs, 0.3 per 10,000 patient-days. The rate of HA-BSIs in Queensland public hospitals is lower than reported by similar studies elsewhere. About one-third of HA-BSIs are attributable to intravascular catheters, predominantly central venous lines, but the vast majority of CLABSIs are contracted outside ICUs. Different sources of HA-BSIs require different prevention strategies.

Biodegradation of kraft lignin by newly isolated Klebsiella pneumoniae, Pseudomonas putida, and Ochrobactrum tritici strains.

PubMed

Xu, Zhaoxian; Qin, Ling; Cai, Mufeng; Hua, Wenbo; Jin, Mingjie

2018-05-01

Bacterial systems have drawn an increasing amount of attention on lignin valorization due to their rapid growth and powerful environmental adaptability. In this study, Klebsiella pneumoniae NX-1, Pseudomonas putida NX-1, and Ochrobactrum tritici NX-1 with ligninolytic potential were isolated from leaf mold samples. Their ligninolytic capabilities were determined by measuring (1) the cell growth on kraft lignin as the sole carbon source, (2) the decolorization of kraft lignin and lignin-mimicking dyes, (3) the micro-morphology changes and transformations of chemical groups in kraft lignin, and (4) the ligninolytic enzyme activities of these three isolates. To the best of our knowledge, this is the first report that Ochrobactrum tritici species can depolymerize and metabolize lignin. Moreover, laccase, lignin peroxidase, and Mn-peroxidase showed high activities in P. putida NX-1. Due to their excellent ligninolytic capabilities, these three bacteria are important supplements to ligninolytic bacteria library and could be valuable in lignin valorization.

Plasmid transferability of KPC into a virulent K2 serotype Klebsiella pneumoniae.

PubMed

Siu, Leung-Kei Kristopher; Huang, David B; Chiang, Tom

2014-03-31

KPC-producing carbapenem-resistant Klebsiella pneumoniae (CRKP) infections are associated with high mortality; however, their virulence determinants are not well defined. We investigated the virulence and plasmid transferability among KPC-containing K. pneumoniae isolates. KPC-2 and -3 were successfully conjugated and retained by a virulent K2 K. pneumoniae recipient isolate. Antimicrobial susceptibility testing showed KPC-2 and -3 donor strains were resistant to more than four classes of antibiotics while the K2 isolate was only initially resistant to ampicillin. After conjugation of KPC-2 and -3, the K2 K. pneumoniae transconjugants became resistant to all beta-lactams. Additionally, the KPC K2 K. pneumoniae transconjugants continued to retain its high serum resistance and murine lethality. Conjugation and retainment of KPC by virulent K2 K. pneumoniae and the ability of the tranconjugants to maintain its high serum resistance and murine lethality after conjugation was demonstrated in this study. These findings are concerning for the potential of KPC-like genes to disseminate among virulent K. pneumoniae isolates.

Genomic Definition of Hypervirulent and Multidrug-Resistant Klebsiella pneumoniae Clonal Groups

PubMed Central

Bialek-Davenet, Suzanne; Criscuolo, Alexis; Ailloud, Florent; Passet, Virginie; Jones, Louis; Delannoy-Vieillard, Anne-Sophie; Garin, Benoit; Le Hello, Simon; Arlet, Guillaume; Nicolas-Chanoine, Marie-Hélène; Decré, Dominique

2014-01-01

Multidrug-resistant and highly virulent Klebsiella pneumoniae isolates are emerging, but the clonal groups (CGs) corresponding to these high-risk strains have remained imprecisely defined. We aimed to identify K. pneumoniae CGs on the basis of genome-wide sequence variation and to provide a simple bioinformatics tool to extract virulence and resistance gene data from genomic data. We sequenced 48 K. pneumoniae isolates, mostly of serotypes K1 and K2, and compared the genomes with 119 publicly available genomes. A total of 694 highly conserved genes were included in a core-genome multilocus sequence typing scheme, and cluster analysis of the data enabled precise definition of globally distributed hypervirulent and multidrug-resistant CGs. In addition, we created a freely accessible database, BIGSdb-Kp, to enable rapid extraction of medically and epidemiologically relevant information from genomic sequences of K. pneumoniae. Although drug-resistant and virulent K. pneumoniae populations were largely nonoverlapping, isolates with combined virulence and resistance features were detected. PMID:25341126

Cross-specificity of protective human antibodies against Klebsiella pneumoniae LPS O-antigen.

PubMed

Rollenske, Tim; Szijarto, Valeria; Lukasiewicz, Jolanta; Guachalla, Luis M; Stojkovic, Katarina; Hartl, Katharina; Stulik, Lukas; Kocher, Simone; Lasitschka, Felix; Al-Saeedi, Mohammed; Schröder-Braunstein, Jutta; von Frankenberg, Moritz; Gaebelein, Gereon; Hoffmann, Peter; Klein, Sabrina; Heeg, Klaus; Nagy, Eszter; Nagy, Gabor; Wardemann, Hedda

2018-06-01

Humoral immune responses to microbial polysaccharide surface antigens can prevent bacterial infection but are typically strain specific and fail to mediate broad protection against different serotypes. Here we describe a panel of affinity-matured monoclonal human antibodies from peripheral blood immunoglobulin M-positive (IgM + ) and IgA + memory B cells and clonally related intestinal plasmablasts, directed against the lipopolysaccharide (LPS) O-antigen of Klebsiella pneumoniae, an opportunistic pathogen and major cause of antibiotic-resistant nosocomial infections. The antibodies showed distinct patterns of in vivo cross-specificity and protection against different clinically relevant K. pneumoniae serotypes. However, cross-specificity was not limited to K. pneumoniae, as K. pneumoniae-specific antibodies recognized diverse intestinal microbes and neutralized not only K. pneumoniae LPS but also non-K. pneumoniae LPS. Our data suggest that the recognition of minimal glycan epitopes abundantly expressed on microbial surfaces might serve as an efficient humoral immunological mechanism to control invading pathogens and the large diversity of the human microbiota with a limited set of cross-specific antibodies.

Assessment of free-living nitrogen fixing microorganisms for commercial nitrogen fixation. [economic analysis of ammonia production

NASA Technical Reports Server (NTRS)

Stokes, B. O.; Wallace, C. J.

1978-01-01

Ammonia production by Klebsiella pneumoniae is not economical with present strains and improving nitrogen fixation to its theoretical limits in this organism is not sufficient to achieve economic viability. Because the value of both the hydrogen produced by this organism and the methane value of the carbon source required greatly exceed the value of the ammonia formed, ammonia (fixed nitrogen) should be considered the by-product. The production of hydrogen by KLEBSIELLA or other anaerobic nitrogen fixers should receive additional study, because the activity of nitrogenase offers a significant improvement in hydrogen production. The production of fixed nitrogen in the form of cell mass by Azotobacter is also uneconomical and the methane value of the carbon substrate exceeds the value of the nitrogen fixed. Parametric studies indicate that as efficiencies approach the theoretical limits the economics may become competitive. The use of nif-derepressed microorganisms, particularly blue-green algae, may have significant potential for in situ fertilization in the environment.

[Diversity analysis of biofilm bacteria on tracheal tubes removed from intubated neonates].

PubMed

Song, Chao; Yu, Jia-lin; Ai, Qing; Liu, Dong; Lu, Wei; Lu, Qi; Peng, Ning-ning

2013-08-01

The catheter-related infections caused by mechanical ventilation have become a intractable clinical problem, and it is related to the formation of bacterial biofilm (BF) on the surface of the implanted material. The majority of natural biofilms are formed by multiple bacterial species. However, there always only one or limited species were detected on tracheal tubes removed from intubated neonates by using traditional methods including bacterium culture and antigen detection. The aims of this study were to observe the bacterial communities diversity of BF on endotracheal tube (ETT), and discuss the difference between traditional bacterium culture methods and the use of molecular biology techniques on the basis of denatured gradient gel electrophoresis (DGGE), to provide new ideas for clinical prevention, diagnosis and treatment of bacterial infections. Thirty-five ETTs were obtained from 26 neonates on mechanical ventilator (from October 2012 to March 2013) in Department of Neonatology of Children's Hospital. Among the patients, 18 were boys and 8 girls, and 19 patients were < 37 weeks gestational age and 7 patients ≥ 37 weeks. DGGE profiling of 16S rDNA gene amplicons was used to assess the diversity of the bacterial population by using the software of quantity one. TA Cloning Kit and sequencing were used to investigate the distribution of bacteria and common dominant bacteria in ETT-BF. The mean bands of 35 ETTs cases were 13.8 ± 5.4 from 16S rDNA PCR-DGGE, and the mean Shanon-Wiener indexes was 2.42 ± 0.38. The 16 ETTs were collected in different stages of diseases from the 7 patients. The indwelling days of 6/7 patients' ETTs increased, the Shanon-siener indexes were decreased. Among the 6 cases from different basic illnesses, and there were different Shanon-siener indexes. The result of molecular cloning and sequencing for 24 dominant bands showed that 35 cases (100%) contained Klebsiella SP·, 28 cases (80%) had Pseudomonas SP·, 27 cases (77%) had Streptococcus SP·, and 32 cases (91%) had Uncultured bacterium, while more than 2 bacterial species were found in 34 cases (97%). 28/35 (80%) Klebsiella SP· and 22/27(82%) Streptococcus SP· were accompanied by Pseudomonas SP·. There were 22 positive results of sputum culture from 26 newborns, including 10 strains (45%) of Klebsiella pneumoniae, 2 strains (9%) of Acinetobacter baumannii, Enterobacter cloacae and non-cultured bacterium in each patient (5%), but only one bacterium isolated from every sputum. Eight sputum samples had normal flora only, corresponding to the ETTs on which Klebsiella and other bacterial genuses were found. The diversity of microbiota in BF on ETT was confirmed. 16S rDNA PCR-DGGE could produce a more complete picture of bacterial community than traditional bacterium culture method. Klebsiella, Pseudomonas and Streptococcus were common dominant bacteria in ETT-BF, and there might be interactions among them in the formation of BF.

First two cases of severe multifocal infections caused by Klebsiella pneumoniae in Switzerland: characterization of an atypical non-K1/K2-serotype strain causing liver abscess and endocarditis.

PubMed

Babouee Flury, Baharak; Donà, Valentina; Buetti, Niccolò; Furrer, Hansjakob; Endimiani, Andrea

2017-09-01

We describe the first two multifocal invasive infections due to Klebsiella pneumoniae recently observed in Switzerland. Phenotypic (MIC assays and string test) and molecular analyses (PCR/Sequencing for bla, virulence factor genes and whole genome sequencing for one strain) were performed to characterize the causative K. pneumoniae isolates. Both K. pneumoniae isolates (Kp1 and Kp2) were pan-susceptible to antibiotics and produced narrow-spectrum SHV β-lactamases. However, only Kp1 was string test positive. Kp1 was of ST380 and caused liver abscess as well as pneumonia and orbital phlegmon in an Eritrean patient. It belonged to the hypervirulent capsular serotype K2 and harboured the classic virulence-associated rmpA and aerobactin genes, fulfilling both the clinical and microbiological definitions for an invasive K. pneumoniae syndrome. Kp2 was of ST1043 and caused both liver abscess and endocarditis in a Swiss patient. Moreover, it did not possess the classic virulence-associated genes. Whole genome sequencing identified less well-known virulence factors in Kp2 that might have contributed to its virulence. Among these there were genes important for intestinal colonization and/or invasion, such as genes involved in adhesion (e.g., fimABCD and mrkABCD), regulation of capsule polysaccharide biosynthesis (e.g., evgS-evgA), as well as iron uptake (iroN), energy conversion, and metabolism. This report confirms the continuous dissemination of hypervirulent K. pneumoniae strains among patients of non-Asian descent in Europe. Moreover, it highlights the genetic background of an atypical hypervirulent K. pneumoniae causing a severe invasive infection despite not possessing the classical virulence characteristics of hypermucoviscous strains. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Differential Th17 response induced by the two clades of the pandemic ST258 Klebsiella pneumoniae clonal lineages producing KPC-type carbapenemase

PubMed Central

Clemente, Ann Maria; Castronovo, Giuseppe; Antonelli, Alberto; D’Andrea, Marco Maria; Tanturli, Michele; Perissi, Eloisa; Paccosi, Sara; Parenti, Astrid; Cozzolino, Federico; Rossolini, Gian Maria

2017-01-01

The spread of KPC-type carbapenemases is mainly attributed to the global dissemination of Klebsiella pneumoniae (KP) strains belonging to the clonal group (CG) 258, including sequence type (ST) 258 and other related STs. Two distinct clades of CG258-KP have evolved, which differ mainly for the composition of their capsular polysaccharides, and recent studies indicate that clade 1 evolved from an ancestor of clade 2 by recombination of a genomic fragment carrying the capsular polysaccharide (cps) locus. In this paper, we investigated the ability of two ST258-KP strains, KKBO-1 and KK207-1, selected as representatives of ST258-KP clade 2 and clade 1, respectively, to activate an adaptive immune response using ex vivo-stimulation of PBMC from normal donors as an experimental model. Our data showed that KKBO-1 (clade 2) induces a Th17 response more efficiently than KK207-1 (clade 1): the percentage of CD4+IL17+ cells and the production of IL-17A were significantly higher in cultures with KKBO-1 compared to cultures with KK207-1. While no differences in the rate of bacterial internalization or in the bacteria-induced expression of CD86 and HLA-DR by monocytes and myeloid dendritic cells were revealed, we found that the two strains significantly differ in inducing the production of cytokines involved in the adaptive immune response, as IL-1β, IL-23 and TNF-α, by antigen-presenting cells, with KKBO-1 being a more efficient inducer than KK207-1. The immune responses elicited by KK207-1 were comparable to those elicited by CIP 52.145, a highly virulent K. pneumoniae reference strain known to escape immune-inflammatory responses. Altogether, present results suggest that CG258-KP of the two clades are capable of inducing a different response of adaptive immunity in the human host. PMID:28586386

Platelet-rich plasma affects bacterial growth in vitro.

PubMed

Mariani, Erminia; Filardo, Giuseppe; Canella, Valentina; Berlingeri, Andrea; Bielli, Alessandra; Cattini, Luca; Landini, Maria Paola; Kon, Elizaveta; Marcacci, Maurilio; Facchini, Andrea

2014-09-01

Platelet-rich plasma (PRP), a blood derivative rich in platelets, is a relatively new technique used in tissue regeneration and engineering. The increased quantity of platelets makes this formulation of considerable value for their role in tissue healing and microbicidal activity. This activity was investigated against five of the most important strains involved in nosocomial infections (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Streptococcus faecalis) to understand the prophylactic role of pure (P)-PRP. Microbicidal proteins released from activated P-PRP platelets were also determined. The microbicidal activity of P-PRP and platelet-poor plasma (PPP) was evaluated on different concentrations of the five bacterial strains incubated for 1, 2, 4 and 18 h and plated on agar for 18-24 h. P-PRP and PPP-released microbicidal proteins were evaluated by means of multiplex bead-based immunoassays. P-PRP and PPP inhibited bacterial growth for up to 2 h of incubation. The effect of P-PRP was significantly higher than that of PPP, mainly at the low seeding concentrations and/or shorter incubation times, depending on the bacterial strain. Chemokine (C-C motif) ligand-3, chemokine (C-C motif) ligand-5 and chemokine (C-X-C motif) ligand-1 were the molecules mostly related to Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus faecalis inhibition. Escherichia coli and Klebsiella pneumoniae were less influenced. The present results show that P-PRP might supply an early protection against bacterial contaminations during surgical interventions because the inhibitory activity is already evident from the first hour of treatment, which suggests that physiological molecules supplied in loco might be important in the time frame needed for the activation of the innate immune response. Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

In vitro evaluation of antibiotic synergy for polymyxin B-resistant carbapenemase-producing Klebsiella pneumoniae.

PubMed

Elemam, Azza; Rahimian, Joseph; Doymaz, Mehmet

2010-10-01

Since carbapenemase-producing Klebsiella pneumoniae strains were first reported in North Carolina, these highly resistant organisms have been isolated with increasing frequency, especially in the New York City area. Polymyxin B is one of the few antimicrobials that retain reliable activity against these organisms. However, polymyxin B MICs are elevated against K. pneumoniae isolates with increasing frequency, leaving clinicians with few therapeutic options. We investigated several antimicrobial agents for potential synergy with polymyxin B against 12 clinical strains of carbapenemase-producing K. pneumoniae. A broth microdilution assay using a 96-well plate was developed in which graded dilutions of polymyxin B and the study drug were incubated with resistant isolates in a checkerboard pattern. Polymyxin B was studied in combination with cefazolin, ceftriaxone, cefepime, imipenem, gentamicin, tigecycline, doxycycline, and rifampin. All K. pneumoniae strains tested positive for K. pneumoniae carbapenemase (KPC) genes by real-time PCR and had elevated polymyxin B MIC values ranging from 16 to 128 μg/ml. Synergy was observed with the combination of polymyxin B and rifampin as well as with polymyxin B and doxycycline, resulting in at least a 4-fold decrease in the polymyxin B MIC. For both combinations, this effect occurred at physiologically achievable concentrations. Less pronounced synergy was noted with tigecycline and polymyxin B. No synergy was observed at physiologic concentrations with the other antimicrobials studied. These results suggest that rifampin, doxycycline, and tigecycline may be useful additions to polymyxin B in the treatment of infections caused by highly resistant carbapenemase-producing K. pneumoniae. Further studies are warranted to determine if these in vitro findings translate into clinical efficacy.

Engineering CRISPR interference system in Klebsiella pneumoniae for attenuating lactic acid synthesis.

PubMed

Wang, Jingxuan; Zhao, Peng; Li, Ying; Xu, Lida; Tian, Pingfang

2018-04-05

Klebsiella pneumoniae is a promising industrial species for bioproduction of bulk chemicals such as 1,3-propanediol, 2,3-butanediol and 3-hydroxypropionic acid (3-HP). However, lactic acid is a troublesome by-product when optimizing for 3-HP production. Therefore, it is highly desirable to minimize lactic acid. Here, we show that lactic acid synthesis can be largely blocked by an engineered CRISPR interference (CRISPRi) system in K. pneumoniae. EGFP was recruited as a reporter of this CRISPRi system. Fluorescence assay of this CRISPRi system showed that enhanced green fluorescent protein (EGFP) expression level was repressed by 85-90%. To further test this CRISPRi system, guide RNAs were designed to individually or simultaneously target four lactate-producing enzyme genes. Results showed that all lactate-producing enzyme genes were significantly repressed. Notably, D-lactate dehydrogenase (ldhA) was shown to be the most influential enzyme for lactic acid formation in micro-aerobic conditions, as inhibiting ldhA alone led to lactic acid level similar to simultaneously repressing four genes. In shake flask cultivation, the strain coexpressing puuC (an aldehyde dehydrogenase catalyzing 3-hydroxypropionaldehyde to 3-HP) and dCas9-sgRNA inhibiting ldhA produced 1.37-fold 3-HP relative to the reference strain. Furthermore, in bioreactor cultivation, this CRISPRi strain inhibiting ldhA produced 36.7 g/L 3-HP, but only generated 1 g/L lactic acid. Clearly, this engineered CRISPRi system largely simplified downstream separation of 3-HP from its isomer lactic acid, an extreme challenge for 3-HP bioprocess. This study offers a deep understanding of lactic acid metabolism in diverse species, and we believe that this CRISPRi system will facilitate biomanufacturing and functional genome studies of K. pneumoniae or beyond.

Draft genome sequence of a KPC-2-producing Klebsiella pneumoniae ST340 carrying blaCTX-M-15 and blaCTX-M-59 genes: a rich genome of mobile genetic elements and genes encoding antibiotic resistance.

PubMed

Casella, Tiago; de Morais, Andressa Batista Zequini; de Paula Barcelos, Diego Diniz; Tolentino, Fernanda Modesto; Cerdeira, Louise Teixeira; Bueno, Maria Fernanda Campagnari; Francisco, Gabriela Rodrigues; de Andrade, Leonardo Neves; da Costa Darini, Ana Lucia; de Oliveira Garcia, Doroti; Lincopan, Nilton; Nogueira, Mara Corrêa Lelles

2018-06-01

Klebsiella pneumoniae is considered an opportunistic pathogen and an important agent of nosocomial and community infections. It presents the ability to capture and harbour several antimicrobial resistance genes and, in this context, the extensive use of carbapenems to treat serious infections has been responsible for the selection of several resistance genes. This study reports the draft genome sequence of a KPC-2-producing K. pneumoniae strain (Kp10) simultaneously harbouring bla CTX-M-15 and bla CTX-M-59 genes isolated from urine culture of a patient with Parkinson's disease. Classical microbiological methods were applied to isolate and identify the strain, and PCR and sequencing were used to identify and characterise the genes and the genetic environment. Whole-genome sequencing (WGS) was performed using a Nextera XT DNA library and a NextSeq platform. WGS analysis revealed the presence of 5915 coding genes, 46 RNA-encoding genes and 255 pseudogenes. Kp10 belonged to sequence type 340 (ST340) of clonal complex 258 (CC258) and carried 20 transferable genes associated with antimicrobial resistance, comprising seven drug classes. Although the simultaneous presence of different bla CTX-M genes in the same strain is rarely reported, the bla KPC-2 , bla CTX-M-15 and bla CTX-M-59 genes were not associated with the same genetic mobile structure in Kp10. These results confirm the capacity of K. pneumoniae to harbour several antimicrobial resistance genes. Thus, this draft genome could help in future epidemiological studies regarding the dissemination of clinically relevant resistance genes. Copyright © 2018 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Detection of acrA, acrB, aac(6')-Ib-cr, and qepA genes among clinical isolates of Escherichia coli and Klebsiella pneumoniae.

PubMed

Heidary, Mohsen; Bahramian, Aghil; Hashemi, Ali; Goudarzi, Mehdi; Omrani, Vahid Fallah; Eslami, Gita; Goudarzi, Hossein

2017-03-01

The distribution of drug resistance among clinical isolates of Escherichia coli and Klebsiella pneumoniae has limited the therapeutic options. The aim of this study was to report the prevalence of quinolone resistance genes among E. coli and K. pneumoniae clinical strains isolated from three educational hospitals of Tehran, Iran. A total of 100 strains of E. coli from Labbafinejad and Taleghani Hospitals and 100 strains of K. pneumoniae from Mofid Children and Taleghani Hospitals were collected between January 2013 and May 2014. Antimicrobial susceptibility tests were done by disk diffusion method based on Clinical and Laboratory Standards Institute guidelines. Detection of qepA, aac(6')-Ib-cr, acrA, and acrB genes was done by polymerase chain reaction (PCR). In this study, fosfomycin and imipenem against E. coli and fosfomycin and tigecycline against K. pneumoniae had the best effect in antimicrobial susceptibility tests. PCR assay using specific primers demonstrated that the prevalence of qepA, aac(6')-Ib-cr, acrA, and acrB genes among the 100 E. coli isolates was 0 (0%), 87 (87%), 92 (92%), and 84 (84%), respectively. The prevalence of qepA, aac(6')-Ib-cr, acrA, and acrB genes among the 100 K. pneumoniae isolates was 4 (4%), 85 (85%), 94 (94%), and 87 (87%), respectively. The distribution of qepA, aac(6')-Ib-cr, acrA, and acrB resistance determinants in E. coli and K. pneumoniae is a great concern. Therefore, infection control and prevention of spread of drug-resistant bacteria need careful management of medication and identification of resistant isolates.

Molecular Characterisation of nfsA Gene in Nitrofurantoin Resistant Uropathogens

PubMed Central

Shanmugam, Dhivyalakshmi; Narayanaswamy, Anbumani

2016-01-01

Introduction Majority of Urinary Tract Infections (UTI’s) are lower UTI’s which constitute the real burden in the primary care setting and are usually treated empirically. Nitrofurantoin is an underused antimicrobial for empiric therapy for community-acquired and nosocomial lower UTIs. Nitrofurantoin has a wide spectrum of action against Escherichia coli, Klebsiella pneumonia and Enterococci, which are the frequent causes of nosocomial lower UTIs and also against multidrug-resistant gram-negative organisms including extended spectrum beta lactamase (ESBL) producers, Amp-C producers and Carbapenamase producers. Aim The study was conducted to describe the resistance pattern of nitrofurantoin and to identify the genes responsible for nitrofurantoin resistance (i.e.) nfsA and the type of mutations involved. Settings and Design This study was conducted in a tertiary care hospital for a period of six months which caters to a total of 1200 beds. Materials and Methods A total of 115 clinical strains of Escherichia coli and Klebsiella pneumoniae including ESBL and Carbapenemase producing isolates were analysed for susceptibility to commonly used antimicrobials. Results ESBL producers 65% and 51% of carbapenems resistant strains were susceptible to nitrofurantoin by minimal inhibitory concentration. MIC to nitrofurantoin was determined by E-strip method. Nitroreductase nfsA gene was detected by PCR in 64 of 70 E.coli isolates with reduced susceptibility to nitrofurantoin. Gene sequencing was done using BLAST algorithm and substitution (N=12) and insertion mutation (N=1) were observed in the resistant strains. Conclusion Nitrofurantoin being an oral antibiotic, its usage in ESBL producers and carbapenamase producers is still warranted. Surprisingly, resistance to nitrofurantoin remains minimal even after extensive use and may be related to the fact that it has multiple mechanisms of action hence may require organisms to develop more than a single mutation to concur resistance. PMID:27504284

[Surveillance of susceptibility of clinical isolates to cefmetazole between 2000 and 2003].

PubMed

Sato, Yuki; Abe, Tomomi; Koga, Tetsufumi; Ito, Kazuyoshi; Tochikawa, Yuko

2005-06-01

For the post-marketing surveillance of cefmetazole (CMZ, Cefmetazon), MICs of injectable beta-lactam antibacterials including CMZ against clinical isolates from 15 medical institutions all over Japan are measured yearly and the incidence rates of resistance in various species are also evaluated. In the first surveillance from June 2000 to March 2001, 574 isolates of 13 species were tested, 548 isolates of the same 13 species were tested in the second surveillance from April 2001 to March 2002, and 654 isolates of the same 13 species were tested in the third surveillance from April 2002 to March 2003. No remarkable changes in the activity of CMZ were observed in these surveillances spanning three years. The activity of CMZ in this study was comparable to that in the studies conducted before Cefmetazon was launched. This result suggests that CMZ still maintains potent activity. Changes in percent resistance of each species to CMZ (MIC of CMZ > or = 32 microg/ml) were as follows: methicillin-susceptible Staphylococcus aureus (MSSA, 0.0% --> 0.0% --> 0.0%), methicillin-resistant Staphylococcus aureus (MRSA, 72.9% --> 87.2% --> 88.7%), Staphylococcus epidermidis (18.5% --> 31.6% --> 14.3%), coagulase-negative Staphylococcus spp. (CNS, 13.3% --> 18.2% --> 21.4%), Escherichia coli (3.6% --> 0.8% --> 2.1%), Klebsiella pneumoniae (3.4% --> 3.8% --> 2.1%), Klebsiella oxytoca (0.0% --> 0.0% --> 0.0%), Proteus mirabilis (2.3% --> 2.1% --> 0.0%), Proteus vulgaris (13.6% --> 6.7% --> 0.0%), Morganella morganii (7.3% --> 0.0% --> 14.0%), Providencia spp. (12.5% --> 0.0% --> 18.2%), Peptostreptococcus spp. (0.0% --> 0.0% --> 0.0%), Bacteroides fragilis (10.3% --> 10.8% --> 17.1%), Bacteroides spp. (78.6% --> 87.5% --> 62.5%). The Change in percent resistance of MRSA, other CNS, and B. flagiris tended to increase. It is necessary to pay much attention to trends observed in these species. Compared to other drugs tested, against MSSA, the activity of CMZ was inferior to that of CEZ, CTM, and FMOX and superior to that SBT/CPZ. Against MRSA, S. epidermidis, and CNS, the tested drugs exhibited little activity. Against Gram-negative bacteria, the activity of CMZ was almost superior to that of CEZ and CTM, and inferior to that of FMOX. Against B. flagiris and other Bacteroides spp., the activity of CMZ was almost superior to that of CEZ and CTM, and comparable to or inferior to that of SBT/CPZ and FMOX.

No Carbapenem Resistance in Pneumonia Caused by Klebsiella Species

PubMed Central

Yayan, Josef; Ghebremedhin, Beniam; Rasche, Kurt

2015-01-01

Abstract Klebsiella species are a common cause of community- and nosocomial-acquired pneumonia. Antibiotic resistance to the class of carbapenem in patients with pneumonia caused by Klebsiella species is unusual. New studies report carbapenem resistance in patients with pneumonia caused by Klebsiella species. This article examines, retrospectively, antibiotic resistance in patients with community- and nosocomial-acquired pneumonia caused by Klebsiella species. The data of all patients with community- and nosocomial-acquired pneumonia caused by Klebsiella species were collected from the hospital charts at the HELIOS Clinic, Witten/Herdecke University, Wuppertal, Germany, within the study period 2004 to 2014. An antibiogram was created from all of the study patients with pneumonia caused by Klebsiella species. Sensitivity and resistance profiles were performed for the different antibiotics that have been consistently used in the treatment of patients with pneumonia caused by Klebsiella species. All demographic, clinical, and laboratory data of all of the patients with pneumonia caused by Klebsiella species were collected from the patients’ records. During the study period of January 1, 2004, to August 12, 2014, 149 patients were identified with community- and nosocomial-acquired pneumonia affected by Klebsiella species. These patients had a mean age of 70.6 ± 13 (107 [71.8%, 95% CI 64.6%–79%] men and 42 [28.2%, 95% CI 21%–35.4%] women). In all of the patients with pneumonia caused by Klebsiella species, there was resistance to ampicillin (P < 0.0001). Many patients with pneumonia caused by Klebsiella species (75.3%) also showed resistance to piperacillin (P < 0.0001). However, no patients with pneumonia caused by Klebsiella species showed resistance to imipenem or meropenem (P < 0.0001). Antibiotic resistance to the antibiotic class of carbapenem was not detected in patients with pneumonia caused by Klebsiella species. PMID:25674753

Expression of ESBL-like activity in infrequently encountered members of the family Enterobacteriaceae.

PubMed

Abbott, Sharon L; Lidgard, Janice A; Cheung, Wendy K W; Obeso, Martha N; Berrada, Zenda L; Janda, J Michael

2012-03-01

A collection of 94 unusual members of the Enterobacteriaceae were screened for the presence of extended spectrum β-lactamases (ESBLs) using the MicroScan ESβL plus dried confirmation panel. Presumptively positive strains were then confirmed for the presence of an ESBL by double disk diffusion, E-test strips (AB Biodisk, Solna, Sweden) and PCR for SHV, TEM, and CTX-M2 genes. Of the 18 strains initially positive on the ESβL panel only three strains (Leminorella grimontii, Klebsiella ozaenae, and Kluyvera ascorbata) were positive by confirmation methods. These results suggest laboratories should be cautious regarding the methodology employed in screening for the presence of ESBLs in enteric bacteria. However, it should be noted that of the 94 strains, 29 were found to be resistant to two or more of the antibiotics present in the MicroScan ESβL plus panel indicating that there are potential treatment issues with these organisms despite their lack of ESBLs.

Studies on the antimicrobial properties of colloidal silver nanoparticles stabilized by bovine serum albumin.

PubMed

Mathew, Thomas V; Kuriakose, Sunny

2013-01-01

Colloidal silver nanoparticles were synthesised using sol-gel method and these nanoparticles were stabilised by encapsulated into the scaffolds of bovine serum albumin. Silver nanoparticles and encapsulated products were characterised by FTIR, NMR, XRD, TG, SEM and TEM analyses. Silver nanoparticle encapsulated bovine serum albumin showed highly potent antibacterial activity towards the bacterial strains such as Staphylococcus aureus, Serratia marcescens, Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae. Copyright © 2012 Elsevier B.V. All rights reserved.

Antimicrobial properties of the stem bark of Saraca indica (Caesalpiniaceae).

PubMed

Sainath, R Shilpakala; Prathiba, J; Malathi, R

2009-01-01

Chloroform, methanol, aqueous and ethanolic extracts of the stem bark of Saraca indica were investigated for their antibacterial and antifungal activity against standard strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, Klebsiella pneumoniae, Proteus mirabilis, Salmonella typhimurium and Streptococcus pneumoniae and the fungi: Candida albicans and Cryptococcus albidus. Methanolic and aqueous extract exhibited antimicrobial activity with MIC ranging from 0.5-2% and 1-3% respectively. Methanolic extract exhibited the strongest activity against both bacteria and fungi.

Current problematic and emergence of carbapenemase-producing bacteria: a brief report from a Libyan hospital.

PubMed

Elramalli, Asma; Almshawt, Nariman; Ahmed, Mohamed Omar

2017-01-01

A collection of 94 Gram-negative bacteria isolates, showing different antimicrobial resistance phenotypes including to the carbapenem classes was investigated. Strains were originated form clinical sources from a single hospital in Tripoli, Libya during 2015 and were identified based on cultural and phenotypic characteristics, and fully characterized by the VITEK automated system. Forty-eight percent (48%) of the collection was identified as Acinetobacter baumannii, 50% Klebsiella pneumoniae and 2% Escherichia coli. Resistance to the carbapenem classes was reported in 96% of the A. baumannii strains and 94% of the K. pneumonia strains. Seventy-eight percent (78%) of the isolates showed different multidrug-resistant (MDR) phenotypes, of which K. pneumoniae expressing the highest rates of MDRs(i.e. 91%). Emergence of resistance to carbapenems in the Gram-negative bacteria is a challenging global problem, particularly for Africa. Surveillance of these pathogens and appropriate actions are urgently required in Libyan healthcare settings.

Current problematic and emergence of carbapenemase-producing bacteria: a brief report from a Libyan hospital

PubMed Central

Elramalli, Asma; Almshawt, Nariman; Ahmed, Mohamed Omar

2017-01-01

A collection of 94 Gram-negative bacteria isolates, showing different antimicrobial resistance phenotypes including to the carbapenem classes was investigated. Strains were originated form clinical sources from a single hospital in Tripoli, Libya during 2015 and were identified based on cultural and phenotypic characteristics, and fully characterized by the VITEK automated system. Forty-eight percent (48%) of the collection was identified as Acinetobacter baumannii, 50% Klebsiella pneumoniae and 2% Escherichia coli. Resistance to the carbapenem classes was reported in 96% of the A. baumannii strains and 94% of the K. pneumonia strains. Seventy-eight percent (78%) of the isolates showed different multidrug-resistant (MDR) phenotypes, of which K. pneumoniae expressing the highest rates of MDRs(i.e. 91%). Emergence of resistance to carbapenems in the Gram-negative bacteria is a challenging global problem, particularly for Africa. Surveillance of these pathogens and appropriate actions are urgently required in Libyan healthcare settings. PMID:28674573

Isolation and molecular identification of endophytic diazotrophs from seeds and stems of three cereal crops.

PubMed

Liu, Huawei; Zhang, Lei; Meng, Aihua; Zhang, Junbiao; Xie, Miaomiao; Qin, Yaohong; Faulk, Dylan Chase; Zhang, Baohong; Yang, Shushen; Qiu, Li

2017-01-01

Ten strains of endophytic diazotroph were isolated and identified from the plants collected from three different agricultural crop species, wheat, rice and maize, using the nitrogen-free selective isolation conditions. The nitrogen-fixing ability of endophytic diazotroph was verified by the nifH-PCR assay that showed positive nitrogen fixation ability. These identified strains were classified by 879F-RAPD and 16S rRNA sequence analysis. RAPD analyses revealed that the 10 strains were clustered into seven 879F-RAPD groups, suggesting a clonal origin. 16S rRNA sequencing analyses allowed the assignment of the 10 strains to known groups of nitrogen-fixing bacteria, including organisms from the genera Paenibacillus, Enterobacter, Klebsiella and Pantoea. These representative genus are not endophytic diazotrophs in the conventional sense. They may have obtained nitrogen fixation ability through lateral gene transfer, however, the evolutionary forces of lateral gene transfer are not well known. Molecular identification results from 16S rRNA analyses were also confirmed by morphological and biochemical data. The test strains SH6A and MZB showed positive effect on the growth of plants.

The structure of the acidic exopolysaccharide produced by Pseudomonas "gingeri" strain Pf9.

PubMed

Cescutti, P; Osman, S F; Fett, W F; Weisleder, D

1995-10-02

The structure of the acidic exopolysaccharide produced by the mushroom pathogen Pseudomonas "gingeri" strain Pf9, a bacterium which causes ginger blotch, was investigated by chemical analysis, mass spectrometry and 1D and 2D NMR spectroscopy. The polysaccharide consists of the linear trisaccharide repeating unit [formula: see text] where the cyclic pyruvic acetal groups at O-4 and O-6 of the mannopyranosyl residues have the S-configuration. Methylation analysis under neutral conditions and NMR data showed that the mannose residues are acetylated at O-2. This exopolysaccharide has the same structure as the E. coli K55 capsular polysaccharide and differs from the Klebsiella K5 capsular polysaccharide only in the position of acetylation (C-2 of the glucopyranose residue).

Emergence of Serratia marcescens isolates possessing carbapenem-hydrolysing β-lactamase KPC-2 from China.

PubMed

Lin, X; Hu, Q; Zhang, R; Hu, Y; Xu, X; Lv, H

2016-09-01

Eighty-three carbapenem-resistant Serratia marcescens isolates were recovered from Zhejiang Provincial People's Hospital, China. The minimum inhibitory concentrations of imipenem, meropenem, and ertapenem for all isolates were 2 to >128 μg/mL. Polymerase chain reaction indicated that 63 S. marcescens isolates produced Klebsiella pneumoniae carbapenemase (KPC)-2. Clone A (15 isolates) and clone B (41 isolates) were the two dominant clones and clone A strains were gradually replaced by clone B strains between 2011 and 2014. The results indicate that blaKPC-2-positive S. marcescens emerged in our hospital as the major mechanism of carbapenem resistance. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Coliform Bacteria and Nitrogen Fixation in Pulp and Paper Mill Effluent Treatment Systems

PubMed Central

Gauthier, Francis; Neufeld, Josh D.; Driscoll, Brian T.; Archibald, Frederick S.

2000-01-01

The majority of pulp and paper mills now biotreat their combined effluents using activated sludge. On the assumption that their wood-based effluents have negligible fixed N, and that activated-sludge microorganisms will not fix significant N, these mills routinely spend large amounts adding ammonia or urea to their aeration tanks (bioreactors) to permit normal biomass growth. N2 fixation in seven Eastern Canadian pulp and paper mill effluent treatment systems was analyzed using acetylene reduction assays, quantitative nitrogenase (nifH) gene probing, and bacterial isolations. In situ N2 fixation was undetectable in all seven bioreactors but was present in six associated primary clarifiers. One primary clarifier was studied in greater detail. Approximately 50% of all culturable cells in the clarifier contained nifH, of which >90% were Klebsiella strains. All primary-clarifier coliform bacteria growing on MacConkey agar were identified as klebsiellas, and all those probed contained nifH. In contrast, analysis of 48 random coliform isolates from other mill water system locations showed that only 24 (50%) possessed the nifH gene, and only 13 (27%) showed inducible N2-fixing activity. Thus, all the pulp and paper mill primary clarifiers tested appeared to be sites of active N2 fixation (0.87 to 4.90 mg of N liter−1 day−1) and a microbial community strongly biased toward this activity. This may also explain why coliform bacteria, especially klebsiellas, are indigenous in pulp and paper mill water systems. PMID:11097883

Enzymic activities of cadmium- and zinc-tolerant strains of Klebsiella (Aerobacter) aerogenes growing in glucose-limited chemostats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pickett, A.W.; Carter, I.S.; Dean, A.C.R.

The activities of phosphatases and some enzymes of glucose metabolism were determined in K. aerogenes NCIB 418 and in two strains derived from it, resistant to 50 ..mu..g Cd/sup 2 +/ ml/sup -1/ and 16..mu..g Zn/sup 2 +/ ml/sup -1/ respectively, during growth at D = 0.38 h/sup -1/ in medium containing ..beta..-glycerophosphate as sole phosphorus source and supplemented with Cd/sup 2 +/ and Zn/sup 2 +/, as appropriate for the resistant strains. The pH-activity profiles of the phosphatases differed from strain to strain but all showed maximum activity at an acid pH and this activity was very much lowermore » in the Zn/sup 2 +/-resistant strain than in the control and even lower in the Cd/sup 2 +/-resistant strain. Resistance to either metal was associated with decreased glucose-6-phosphate dehydrogenase activity and increased phosphoglucose isomerase activity, suggesting an increased flow of carbon through the Embden-Meyerhof pathway relative to the pentose phosphate pathway, but the efficiency of the conversion of glucose into biomass was largely unaffected. Glucose phosphoenolpyruvate phosphotransferase activity was also lower in the resistant strains. 25 references, 1 figure, 1 table.« less

Comparative analysis of the complete genome of KPC-2-producing Klebsiella pneumoniae Kp13 reveals remarkable genome plasticity and a wide repertoire of virulence and resistance mechanisms

PubMed Central

2014-01-01

Background Klebsiella pneumoniae is an important opportunistic pathogen associated with nosocomial and community-acquired infections. A wide repertoire of virulence and antimicrobial resistance genes is present in K. pneumoniae genomes, which can constitute extra challenges in the treatment of infections caused by some strains. K. pneumoniae Kp13 is a multidrug-resistant strain responsible for causing a large nosocomial outbreak in a teaching hospital located in Southern Brazil. Kp13 produces K. pneumoniae carbapenemase (KPC-2) but is unrelated to isolates belonging to ST 258 and ST 11, the main clusters associated with the worldwide dissemination of KPC-producing K. pneumoniae. In this report, we perform a genomic comparison between Kp13 and each of the following three K. pneumoniae genomes: MGH 78578, NTUH-K2044 and 342. Results We have completely determined the genome of K. pneumoniae Kp13, which comprises one chromosome (5.3 Mbp) and six plasmids (0.43 Mbp). Several virulence and resistance determinants were identified in strain Kp13. Specifically, we detected genes coding for six beta-lactamases (SHV-12, OXA-9, TEM-1, CTX-M-2, SHV-110 and KPC-2), eight adhesin-related gene clusters, including regions coding for types 1 (fim) and 3 (mrk) fimbrial adhesins. The rmtG plasmidial 16S rRNA methyltransferase gene was also detected, as well as efflux pumps belonging to five different families. Mutations upstream the OmpK35 porin-encoding gene were evidenced, possibly affecting its expression. SNPs analysis relative to the compared strains revealed 141 mutations falling within CDSs related to drug resistance which could also influence the Kp13 lifestyle. Finally, the genetic apparatus for synthesis of the yersiniabactin siderophore was identified within a plasticity region. Chromosomal architectural analysis allowed for the detection of 13 regions of difference in Kp13 relative to the compared strains. Conclusions Our results indicate that the plasticity occurring at many hierarchical levels (from whole genomic segments to individual nucleotide bases) may play a role on the lifestyle of K. pneumoniae Kp13 and underlie the importance of whole-genome sequencing to study bacterial pathogens. The general chromosomal structure was somewhat conserved among the compared bacteria, and recombination events with consequent gain/loss of genomic segments appears to be driving the evolution of these strains. PMID:24450656

Faecal colonization of E. coli and Klebsiella spp. producing extended-spectrum beta-lactamases and plasmid-mediated AmpC in Mozambican university students.

PubMed

Chirindze, L M; Zimba, T F; Sekyere, J O; Govinden, U; Chenia, H Y; Sundsfjord, A; Essack, S Y; Simonsen, G S

2018-05-30

In recent years, the world has seen a surge in Enterobacteriaceae resistant to broad-spectrum beta-lactam antibiotics due to the production of extended-spectrum beta-lactamases (ESBLs) or plasmid-mediated AmpC (pAmpC) enzymes. Data on the epidemiology of cephalosporin-resistant Enterobacteriaceae in Sub-Saharan Africa are still limited. Two hundred seventy-five non-repetitive stool samples were collected from Mozambican university students of both sexes. Samples were cultured on MacConkey agar with and without ceftriaxone (1 mg/L) for selection of third-generation cephalosporin-resistant isolates, which were subjected to antimicrobial susceptibility testing by disc diffusion, characterization of resistance genes by PCR and ERIC-PCR analysis for strain clonality. Among the 275 students, 55 (20%) carried a total of 56 E. coli (n = 35) and Klebsiella spp. (n = 21) isolates resistant to ceftriaxone and phenotypically positive for ESBL- and/or pAmpC-production. Forty-three percent of the isolates (24/56) contained only ESBL genes, 11% (6/56) only pAmpC genes, and 36% (20/56) both ESBL and pAmpC genes. The remaining six isolates were negative for the CTX-M/pAmpC genes included in the test panel. E. coli and Klebsiella spp. combined demonstrated 70% resistance to tetracycline and co-trimoxazole, 63% to ceftazidime and 34% to ciprofloxacin. In total, 89% of ESBL/pAmpC-positive isolates were defined as multi-resistant by being resistant to three or more antibiotic classes. ERIC-PCR fingerprinting demonstrated low similarity among isolates. None of the participants reported recent hospitalization and just 12.5% had taken antibiotics 3 months prior to the study. This study demonstrated 20% colonization with multi-resistant E. coli and Klebsiella spp. among Mozambican students with a diversity of ESBL and pAmpC genes. Colonization was not related to prior hospitalization or antimicrobial consumption.

Dissemination of Multidrug-Resistant, Class I and II Integrons and Molecular Typing of CTX-M-producing Klebsiella pneumoniae.

PubMed

Akya, Alisha; Elahi, Azam; Chegenelorestani, Roya; Rezaee, Mahya

2018-01-01

Klebsiella pneumoniae ( K. pneumoniae ) is an important opportunistic pathogen causes serious community and hospital-acquired infections, which is highly resistant to antibiotics. We aimed to determine the frequency of multidrug resistant (MDR) and molecular typing of clinical isolates of K. pneumoniae . One hundred isolates of K. pneumoniae were collected from clinical samples in three general hospitals in Kermanshah. The antimicrobial susceptibility and extended-spectrum beta-lactamases (ESBL) production of isolates were determined using disk diffusion and combined disk methods, respectively. The bla CTX-M gene, class I and II integrons were detected using polymerase chain reaction. The bla CTX-M positive isolates were selected for genotyping using pulsed-field gel electrophoresis (PFGE). MDR phenotype was observed in 56% of isolates. The 40% of isolates were ESBL positive and 35 isolates contained bla CTX-M . Class I and II of integrons were detected in 50 (89.2%) and 39 (69.6%) of MDR isolates, respectively. PFGE patterns of K. pneumoniae bla CTX-M positive isolates indicated 19 clusters (X 1-19 ) with different genotype patterns. The study findings highlight the concern of circulating MDR strains of K. pneumoniae with bla CTX-M and class I and II integrons in Kermanshah hospitals. The presence of integrons among isolates may facilitate the spread of new resistance genes in this bacterium. Therefore, surveillance for the spread of MDR strains of this bacterium is recommended in hospitals.

The Klebsiella pneumoniae O Antigen Contributes to Bacteremia and Lethality during Murine Pneumonia

PubMed Central

Shankar-Sinha, Sunita; Valencia, Gabriel A.; Janes, Brian K.; Rosenberg, Jessica K.; Whitfield, Chris; Bender, Robert A.; Standiford, Ted J.; Younger, John G.

2004-01-01

Bacterial surface carbohydrates are important pathogenic factors in gram-negative pneumonia infections. Among these factors, O antigen has been reported to protect pathogens against complement-mediated killing. To examine further the role of O antigen, we insertionally inactivated the gene encoding a galactosyltransferase necessary for serotype O1 O-antigen synthesis (wbbO) from Klebsiella pneumoniae 43816. Analysis of the mutant lipopolysaccharide by sodium dodecyl sulfate-polyacrylamide gel electrophoresis confirmed the absence of O antigen. In vitro, there were no detectable differences between wild-type K. pneumoniae and the O-antigen-deficient mutant in regard to avid binding by murine complement C3 or resistance to serum- or whole-blood-mediated killing. Nevertheless, the 72-h 50% lethal dose of the wild-type strain was 30-fold greater than that of the mutant (2 × 103 versus 6 × 104 CFU) after intratracheal injection in ICR strain mice. Despite being less lethal, the mutant organism exhibited comparable intrapulmonary proliferation at 24 h compared to the level of the wild type. Whole-lung chemokine expression (CCL3 and CXCL2) and bronchoalveolar inflammatory cell content were also similar between the two infections. However, whereas the wild-type organism produced bacteremia within 24 h of infection in every instance, bacteremia was not seen in mutant-infected mice. These results suggest that during murine pneumonia caused by K. pneumoniae, O antigen contributes to lethality by increasing the propensity for bacteremia and not by significantly changing the early course of intrapulmonary infection. PMID:14977947

Aminoglycoside therapy for childhood urinary tract infection due to extended-spectrum β-lactamase-producing Escherichia coli or Klebsiella pneumoniae.

PubMed

Han, Seung Beom; Lee, Sung Chul; Lee, Soo Young; Jeong, Dae Chul; Kang, Jin Han

2015-10-13

The rate of urinary tract infections (UTIs) due to extended-spectrum β-lactamase (ESBL)-producing bacterial strains requiring carbapenem therapy has been increasing in children. This study was conducted to evaluate the effect of non-carbapenem antibiotic therapy on childhood UTIs caused by ESBL-producing Escherichia coli or Klebsiella pneumoniae. Medical records of children diagnosed with febrile UTIs due to E. coli or K. pneumoniae between 2010 and 2014 were retrospectively reviewed. The enrolled children were divided into two groups: the ESBL group and the non-ESBL group. Clinical characteristics and therapeutic responses were compared between the two groups. A total of 211 episodes of UTI (204 caused by E. coli; seven caused by K. pneumoniae) were identified in 205 children. Twenty-two (10.4 %) episodes were categorized into the ESBL group. There was no significant difference in the type of antibiotic administered between the two groups. No carbapenems were administered; however, aminoglycosides were administered for 79.1 % of the total episodes. Although empirical antibiotics were appropriate for more episodes in the non-ESBL group compared with the ESBL group (100.0 % vs. 90.9 %, p = 0.011), there were no significant differences in the frequency of defervescence, bacterial eradication from the urine, acute pyelonephritis and vesicoureteral reflux or fever duration between the two groups. Non-carbapenem antibiotics showed favourable therapeutic effects on childhood UTIs caused by ESBL-producing strains. Aminoglycosides can be an alternative to carbapenems in such cases.

Physiological and molecular characteristics of carbapenem resistance in Klebsiella pneumoniae and Enterobacter aerogenes.

PubMed

Pereira, Rito Santo; Dias, Vanessa Cordeiro; Ferreira-Machado, Alessandra Barbosa; Resende, Juliana Alves; Bastos, André Netto; Andrade Bastos, Lucas Quinet; Andrade Bastos, Victor Quinet; Bastos, Ricardo Villela; Da Silva, Vânia Lúcia; Diniz, Cláudio Galuppo

2016-06-30

Bacterial resistance is a growing concern in the nosocomial environment in which Klebsiella pneumoniae and Enterobacter aerogenes play an important role due to their opportunism and carbapenemase-production. This work aimed to evaluate physiological and molecular characteristics of carbapenem-resistant K. pneumoniae and E. aerogenes isolated in a Brazilian tertiary hospital. In total, 42 carbapenem-resistant bacteria isolated from clinical specimens were included (21 K. pneumoniae and 21 E. aerogenes). Drug-sensitive K. pneumoniae (n = 27) were also included. Antimicrobial susceptibility and biocide tolerance patterns, hemolytic activity, tolerance to oxidative stress, and aggregative ability were assessed. Genetic markers related to carbapenem resistance, or ESBL-production were screened by PCR. Compared to drug-sensitive strains, carbapenem-resistant K. pneumoniae were more tolerant to biocides and to oxidative stress, and they displayed an increase in biofilm formation. The genetic markers blaKPC (95.2%) and blaTEM (90.5%) were the most frequent. Among the carbapenem-resistant E. aerogenes strains, blaKPC, and blaTEM were detected in all bacteria. Drug-sensitive E. aerogenes were not isolated in the same period. blaSHV, blaVIM, and blaCTX markers were also observed among carbapenem-resistant bacteria. Results suggest that carbapenemase-producing enterobacteria might show peculiar characteristics regarding their physiology associated with their environmental persistency, virulence, and multidrug resistance. The observed phenomenon may have implications not only for antimicrobial chemotherapy, but also for the prognosis of infectious diseases and infection control.

Survey of clustered regularly interspaced short palindromic repeats and their associated Cas proteins (CRISPR/Cas) systems in multiple sequenced strains of Klebsiella pneumoniae.

PubMed

Ostria-Hernández, Martha Lorena; Sánchez-Vallejo, Carlos Javier; Ibarra, J Antonio; Castro-Escarpulli, Graciela

2015-08-04

In recent years the emergence of multidrug resistant Klebsiella pneumoniae strains has been an increasingly common event. This opportunistic species is one of the five main bacterial pathogens that cause hospital infections worldwide and multidrug resistance has been associated with the presence of high molecular weight plasmids. Plasmids are generally acquired through horizontal transfer and therefore is possible that systems that prevent the entry of foreign genetic material are inactive or absent. One of these systems is CRISPR/Cas. However, little is known regarding the clustered regularly interspaced short palindromic repeats and their associated Cas proteins (CRISPR/Cas) system in K. pneumoniae. The adaptive immune system CRISPR/Cas has been shown to limit the entry of foreign genetic elements into bacterial organisms and in some bacteria it has been shown to be involved in regulation of virulence genes. Thus in this work we used bioinformatics tools to determine the presence or absence of CRISPR/Cas systems in available K. pneumoniae genomes. The complete CRISPR/Cas system was identified in two out of the eight complete K. pneumoniae genomes sequences and in four out of the 44 available draft genomes sequences. The cas genes in these strains comprises eight cas genes similar to those found in Escherichia coli, suggesting they belong to the type I-E group, although their arrangement is slightly different. As for the CRISPR sequences, the average lengths of the direct repeats and spacers were 29 and 33 bp, respectively. BLAST searches demonstrated that 38 of the 116 spacer sequences (33%) are significantly similar to either plasmid, phage or genome sequences, while the remaining 78 sequences (67%) showed no significant similarity to other sequences. The region where the CRISPR/Cas systems were located is the same in all the Klebsiella genomes containing it, it has a syntenic architecture, and is located among genes encoding for proteins likely involved in metabolism and resistance to antibiotics. The CRISPR/Cas system is not widely distributed in K. pneumoniae genomes, those present most likely belong to type I-E with few differences from the arrangement of the cse3 gene and most of the spacers have not been are not described yet. Given that the CRISPR/Cas system is scarcely distributed among K. pneumoniae genomes it is not clear whether it is involved in either immunity against foreign genetic material or virulence. We consider that this study represents a first step to understand the role of CRISPR/Cas in K. pneumoniae.

[Cervical necrotizing fasciitis caused by Klebsiella pneumoniae: three cases report and review of literature].

PubMed

Cong, Tiechuan; Liu, Yuhe; Gao, Weihua; Li, Tiancheng; Wang, Quangui; Xiao, Shuifang; Qin, Yong

2013-10-01

To analyze the clinical manifestations of three cases of cervical necrotizing fasciitis caused by klebsiella pneumoniae and to analyze the published articles concerning the relationship between invasive klebsiella syndrome and necrotizing fasciitis in Chinese Mainland. We have retrospectively analyzed three cases of cervical necrotizing fasciitis caused by klebsiella pneumoniae treated in our department between 2003 and 2012. We also reviewed the Chinese-language scientific literature included in the WanFang data by searching with the following key words: necrotizing fasciitis, klebsiella pneumoniae and liver abscess. These patients recovered uneventfully without obvious complications or disseminated infection foci. Sporadic cases of invasive klebsiella syndrome were reported without necrotizing fasciitis involvement in Chinese Mainland. Cervical necrotizing fasciitis caused by klebsiella pneumoniae may give rise to disseminated infection but there has been no such case report in Chinese Mainland.

Plasmid transferability of KPC into a virulent K2 serotype Klebsiella pneumoniae

PubMed Central

2014-01-01

Background KPC-producing carbapenem-resistant Klebsiella pneumoniae (CRKP) infections are associated with high mortality; however, their virulence determinants are not well defined. Methods We investigated the virulence and plasmid transferability among KPC-containing K. pneumoniae isolates. Results KPC-2 and -3 were successfully conjugated and retained by a virulent K2 K. pneumoniae recipient isolate. Antimicrobial susceptibility testing showed KPC-2 and -3 donor strains were resistant to more than four classes of antibiotics while the K2 isolate was only initially resistant to ampicillin. After conjugation of KPC-2 and -3, the K2 K. pneumoniae transconjugants became resistant to all beta-lactams. Additionally, the KPC K2 K. pneumoniae transconjugants continued to retain its high serum resistance and murine lethality. Conclusions Conjugation and retainment of KPC by virulent K2 K. pneumoniae and the ability of the tranconjugants to maintain its high serum resistance and murine lethality after conjugation was demonstrated in this study. These findings are concerning for the potential of KPC-like genes to disseminate among virulent K. pneumoniae isolates. PMID:24678611

Emergence of KPC-producing Klebsiella pneumoniae in Uruguay: infection control and molecular characterization

PubMed Central

Marquez, C; Ingold, A; Echeverría, N; Acevedo, A; Vignoli, R; García-Fulgueiras, V; Viroga, J; Gonzalez, O; Odizzio, V; Etulain, K; Nuñez, E; Albornoz, H; Borthagaray, G; Galiana, A

2014-01-01

We describe the first outbreak of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-KP), the infection control measures adopted and the shift in resistance patterns of isolates during antibiotic treatment. The ST258 KPC-KP strain exhibited a multiresistant antibiotic phenotype including co-resistance to gentamycin, colistin and tigecycline intermediate susceptibility. Isolates before and after treatment had different behaviour concerning their antibiotic susceptibility and the population analysis profile study. A progressive increase in the aminoglycosides (acquiring amicacin resistance) and β-lactam MICs, and a decreased susceptibility to fosfomycin was observed throughout the administration of combined antimicrobial regimens including meropenem. A high meropenem resistance KPC-KP homogeneous population (MIC 256 Jg/mL), could arise from the meropenem heterogeneous low-level resistance KPC-KP population (MIC 8 Jg/mL), by the selective pressure of the prolonged meropenem therapy. The kpc gene was inserted in a Tn4401 isoform a, and no transconjugants were detected. The core measures adopted were successful to prevent evolution towards resistance dissemination. PMID:25356345

Optimization of tannase production by a novel Klebsiella pneumoniae KP715242 using central composite design.

PubMed

Kumar, Mukesh; Rana, Shiny; Beniwal, Vikas; Salar, Raj Kumar

2015-09-01

A novel tannase producing bacterial strain was isolated from rhizospheric soil of Acacia species and identified as Klebsiella pneumoniae KP715242. A 3.25-fold increase in tannase production was achieved upon optimization with central composite design using response surface methodology. Four variables namely pH, temperature, incubation period, and agitation speed were used to optimize significant correlation between the effects of these variables on tannase production. A second-order polynomial was fitted to data and validated by ANOVA. The results showed a complex relationship between variables and response given that all factors were significant and could explain 99.6% of the total variation. The maximum production was obtained at 5.2 pH, 34.97 °C temperature, 103.34 rpm agitation speed and 91.34 h of incubation time. The experimental values were in good agreement with the predicted ones and the models were highly significant with a correlation coefficient ( R 2 ) of 0.99 and a highly significant F-value of 319.37.

Growth and heavy metal removal by Klebsiella aerogenes at different pH and temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Shahwani, M.F.; Jazrawi, S.F.; Al-Rawi, E.H.

1984-01-01

A strain of Klebsiella aerogenes isolated from Rustamiyah Station for treatment of wastewater was examined for its ability to grow in a media supplemented with maximum tolerance concentrations of Pb/sup + +/, Zn/sup + +/, Ni/sup + +/, and Cd/sup + +/, separately, at different temperatures and initial pH. The results indicated that at 28/sup 0/C during the first 24 hr, Pb/sup + +/ and Ni/sup + +/ had no effect on the growth of the bacteria, while the presence of Zn/sup + +/ and Cd/sup + +/ decreased the cell count. The growth reached a maximum level after themore » second day and started to decrease gradually. The bacterial count at 37/sup 0/C was less than that at 28/sup 0/C. No bacterial multiplication occurred at 44/sup 0/C. There was little difference between heavy metal removal at 28 and 37/sup 0/C. At 44/sup 0/C, little removal took place. In general, slightly acidic or neutral medium was better for both bacterial growth and metal removal.« less

Novel variants of the qnrB gene, qnrB31 and qnrB32, in Klebsiella pneumoniae.

PubMed

Wang, Dongguo; Wang, Haibao; Qi, Yongxiao; Liang, Yong; Zhang, Jing; Yu, Lianhua

2011-12-01

Quinolone resistance in the family Enterobacteriaceae is mostly attributed to the accumulation of mutations in the bacterial enzymes targeted by fluoroquinolones: DNA gyrase and DNA topoisomerase IV. Here we isolated the Klebsiella pneumoniae strains KP3606 and KP4707 from different specimens from 2008 to 2010 in Taizhou Municipal Hospital of China, and discovered a new subtype qnrB31, for which the GenBank accession number is HQ418999, and another new subtype qnrB32, for which the GenBank accession number is HQ704413. Susceptibility testing showed that KP3606 had a reduced susceptibility (MIC ≥0.5 µg ml(-1)) to quinolones, while KP4707 was resistant to quinolones. Of all qnrB alleles, the novel variants the qnrB32 gene and qnrB31 gene have the highest amino acid identity. The results suggested that of all the various genes involved in resistance to quinolones, the qnrB gene is the most likely to be mutated, and plasmids might play a role in the dissemination and evolution of qnrB genes. © 2011 SGM

Genomically Informed Surveillance for Carbapenem-Resistant Enterobacteriaceae in a Health Care System.

PubMed

Pecora, Nicole D; Li, Ning; Allard, Marc; Li, Cong; Albano, Esperanza; Delaney, Mary; Dubois, Andrea; Onderdonk, Andrew B; Bry, Lynn

2015-07-28

Carbapenem-resistant Enterobacteriaceae (CRE) are an urgent public health concern. Rapid identification of the resistance genes, their mobilization capacity, and strains carrying them is essential to direct hospital resources to prevent spread and improve patient outcomes. Whole-genome sequencing allows refined tracking of both chromosomal traits and associated mobile genetic elements that harbor resistance genes. To enhance surveillance of CREs, clinical isolates with phenotypic resistance to carbapenem antibiotics underwent whole-genome sequencing. Analysis of 41 isolates of Klebsiella pneumoniae and Enterobacter cloacae, collected over a 3-year period, identified K. pneumoniae carbapenemase (KPC) genes encoding KPC-2, -3, and -4 and OXA-48 carbapenemases. All occurred within transposons, including multiple Tn4401 transposon isoforms, embedded within more than 10 distinct plasmids representing incompatibility (Inc) groups IncR, -N, -A/C, -H, and -X. Using short-read sequencing, draft maps were generated of new KPC-carrying vectors, several of which were derivatives of the IncN plasmid pBK31551. Two strains also had Tn4401 chromosomal insertions. Integrated analyses of plasmid profiles and chromosomal single-nucleotide polymorphism (SNP) profiles refined the strain patterns and provided a baseline hospital mobilome to facilitate analysis of new isolates. When incorporated with patient epidemiological data, the findings identified limited outbreaks against a broader 3-year period of sporadic external entry of many different strains and resistance vectors into the hospital. These findings highlight the utility of genomic analyses in internal and external surveillance efforts to stem the transmission of drug-resistant strains within and across health care institutions. We demonstrate how detection of resistance genes within mobile elements and resistance-carrying strains furthers active surveillance efforts for drug resistance. Whole-genome sequencing is increasingly available in hospital laboratories and provides a powerful and nuanced means to define the local landscape of drug resistance. In this study, isolates of Klebsiella pneumoniae and Enterobacter cloacae with resistance to carbapenem antibiotics were sequenced. Multiple carbapenemase genes were identified that resided in distinct transposons and plasmids. This mobilome, or population of mobile elements capable of mobilizing drug resistance, further highlighted the degree of strain heterogeneity while providing a detailed timeline of carbapenemase entry into the hospital over a 3-year period. These surveillance efforts support effective targeting of infection control resources and the development of institution-specific repositories of resistance genes and the mobile elements that carry them. Copyright © 2015 Pecora et al.

Synthesis and in vitro activity of dicationic indolyl diphenyl ethers as novel potent antibiotic agents against drug-resistant bacteria.

PubMed

Chen, Xiaofang; Hu, Xinxin; Wu, Yanbin; Liu, Yonghua; Bian, Cong; Nie, Tongying; You, Xuefu; Hu, Laixing

2017-02-15

A series of 4,4'-bis-[2-(6-N-substituted-amidino)indolyl] diphenyl ether have been synthesized and tested for their in vitro antibacterial activity including a range of Gram-positive and Gram-negative pathogens and cytotoxicity. Most of these compounds have mainly shown anti-Gram positive bacteria activities especially against drug resistant bacterial strains MRSA, MRSE and VRE. The anti-MRSA and anti-MRSE activities of compound 7a and 7j were more potent than that of the lead compound 2, levofloxacin and vancomycin. Interestingly, 7j had greatly improved anti negative bacterial activity, especially for the producing NDM-1 Klebsiella pneumonia strain and less toxic than that of the lead compound 2. Copyright © 2017 Elsevier Ltd. All rights reserved.

Carbapenemase-Producing Enterobacteriaceae in Yunnan Province, China.

PubMed

Rui, Zheng; Dehua, Liu; Hua, Niu; Yue, Feng; Yunmin, Xu; Jianhua, Li; Xueshan, Xia

2016-11-22

Among 144 carbapenem-resistant Enterobacteriaceae strains isolated from 4 hospitals in Yunnan province, 113 were identified as carbapenemase-producing Enterobacteriaceae (CPE). Bla KPC-2 (99/113, 87.6%) was the most common carbapenemase gene and Klebsiella pneumoniae (100/113, 88.5%) was the most common species. Bla NDM-1 (11/113, 9.7%), bla IMP-4 (10/113, 8.8%), and bla IMP-1 (1/113, 0.9%) genes were also detected. Extended-spectrum β-lactamase genes were common in CPE, and the SHV- and CTX-M-types were predominant.

Silver nanoparticle production by Rhizopus stolonifer and its antibacterial activity against extended spectrum {beta}-lactamase producing (ESBL) strains of Enterobacteriaceae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banu, Afreen; Rathod, Vandana, E-mail: drvandanarathod@rediffmail.com; Ranganath, E.

Highlights: {yields} Silver nanoparticle production by using Rhizopus stolonifer. {yields} Antibacterial activity of silver nanoparticles against extended spectrum {beta}-lactamase producing (ESBL) strains of Enterobacteriaceae. {yields} Synergistic effect of antibiotics with silver nanoparticles towards ESBL-strains. {yields} Characterization of silver nanoparticles made by UV-vis spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transformed infrared (FTIR) spectroscopy, atomic force microscopy (AFM). -- Abstract: This report focuses on the synthesis of silver nanoparticles using the fungus, Rhizopus stolonifer and its antimicrobial activity. Research in nanotechnology highlights the possibility of green chemistry pathways to produce technologically important nanomaterials. Characterization of newly synthesized silvermore » nanoparticles was made by UV-visible absorption spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectroscopy and atomic force microscope (AFM). TEM micrograph revealed the formation of spherical nanoparticles with size ranging between 3 and 20 nm. The biosynthesized silver nanoparticles (AgNPs) showed excellent antibacterial activity against ESBL-strains which includes E. coli, Proteus. sp. and Klebsiella sp.« less

An antibacterial and antiviral peptide produced by Enterococcus mundtii ST4V isolated from soya beans.

PubMed

Todorov, Svetoslav D; Wachsman, Mónica B; Knoetze, Hendriëtte; Meincken, Martina; Dicks, Leon M T

2005-06-01

Enterococcus mundtii ST4V, isolated from soya beans, produces a 3950Da antibacterial peptide active against Gram-positive and Gram-negative bacteria, including Enterococcus faecalis, Streptococcus spp., Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae and Staphylococcus aureus. The peptide also inactivated the herpes simplex viruses HSV-1 (strain F) and HSV-2 (strain G), a polio virus (PV3, strain Sabin) and a measles virus (strain MV/BRAZIL/001/91, an attenuated strain of MV). MV, HSV-1 and HSV-2 were 95.5%-99.9% inactivated by peptide ST4V at 400 microg/ml. Monkey kidney Vero cells were not inactivated, even at four times the level peptide ST4V displayed antiviral activity, indicating that the effect was not due to cytotoxicity. Complete inactivation or significant reduction in antimicrobial activity was observed after treatment of peptide ST4V with Proteinase K, pronase, pepsin and trypsin. No change in antimicrobial activity was recorded after treatment with alpha-amylase, suggesting that peptide ST4V was not glycosylated. This is the first description of an antibacterial and antiviral peptide with such broad-spectrum of activity, produced by a lactic acid bacterium.

[Microbial resistance to formaldehyde. I. Comparative quantitative studies in some selected species of vegetative bacteria, bacterial spores, fungi, bacteriophages and viruses].

PubMed

Spicher, G; Peters, J

1976-12-01

The resistence of different microorganisms to formaldehyde was determined. As test objects served gram-negative and gram-positive vegetative germs (Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella paratyphi-B, Staphylococcus aureus, Streptococcus faecalis), bacterial spores (Bacillus cereus, Bacillus pumilus, Bacillus stearothermophilus, Bacillus subtilis), fungi (Aspergillus niger, Candida albicans), bacteriophages (Escherichia coli phages, T1, T2, T3), and viruses (adenovirus, poliomyelitis virus, vaccinia virus). For the studies, suspensions of germs were exposed at identical temperature (20 degrees C) and pH (7.0). The microbicidal effect of formaldehyde was measured by the decrease of the proportion of germs capable of multiplication in the suspension (lg (N/N0); where: N0 equals initial number of germs capable of multiplication; N equals number of germs capable of multiplication after exposure to formaldehyde). For all germs the dependence of the microbicidal effect on the concentration of formaldehyde was determined. In all experiments, the duration of exposure was two hours. Pseudomonas aeruginosa, Klebsiella pneumoniae, and Salmonella paratyphi-B were found to be more susceptible than Staphylococcus aureus (vf. Fig. 1 A). The strains of Pseudomonas aeruginosa used were widely varying as to their susceptibility. To obtain equal microbicidal effects, concentrations of formaldehyde almost three times as high had to be used for the most resistant strain than were necessary for the most susceptible strain of Pseudomonas aeruginosa. All strains of Klebsiella pneumoniae examined were found to have an identical resistence to formaldehyde. Streptococcus faecalis was even more resistant to formaldehyde than Staphylococcus aureus. In the case of Streptococcus faecalis, a concentration of formaldehyde about three times as high had to be used to obtain microbicidal effects of identical magnitude. For the killing of Candida albicans cells concentrations of formaldehyde not higher than those needed for the killing of vegetative gram-negative bacteria were necessary. The conidia of Aspergillus niger were found to be more resistant than the cells of Candida albicans but did not require any higher concentrations than for the killing of Staphylococcus aureus (see Fig. 1 B). In the case of bacterial spores, a special phenomenon was observed. If the spores had been exposed to a temperature of 80 and 95 degrees C, respectively (depending on the species involved) for one or two hours following exposure to formaldehyde, a considerably higher number of spores was found to be capable of germination and colony formation than without such treatment (heat activation: cf. Fig. 2A and Fig. 2B). The spores of Bacillus cereus had only a relatively low resistance to formaldehyde. To reduce the proportion of the spores capable of colony formation to 1/10000, a 2.9% formaldehyde concentration was necessary without heat activation and one of 10.8% with heat activation...

Prevalence and Fate of Carbapenemase Genes in a Wastewater Treatment Plant in Northern China

PubMed Central

Yang, Fengxia; Mao, Daqing; Zhou, Hao; Luo, Yi

2016-01-01

Carbapenemase-producing strains of bacteria, which were primarily found in the medical field, have increasingly been found in the environment, thus posing potential risks to public health. One possible way for carbapenemase genes to enter the environment is via wastewater. Therefore, the goal of this study was to determine the occurrence and fate of five high-risk carbapenemase genes in a wastewater treatment plant (WWTP) in northern China using real-time qPCR. Results showed that the blaKPC-2, blaGES-1, and blaIMP-1 genes prevailed throughout all processing stages (even in the chlorination disinfection unit) in the WWTP, whereas the blaVIM-2 and blaOXA-48 genes were not detected in all samples. Worryingly, considerable amounts of carbapenemase genes ((1.54 ± 0.61) × 103 copies/mL to (2.14± 0.41) × 105 copies/mL) were detected in WWTP effluent samples, while the majority of the carbapenemase genes were transported to the dewatered sludge with concentrations from (6.51 ± 0.14) × 109 copies/g to (6.18 ± 0.63) × 1010 copies/g dry weight. Furthermore, a total of 97 KPC-2-producing strains, belonging to 8 bacterial genera, were isolated from the WWTP. Sequencing of 16S rRNA revealed that most of KPC-2 producing isolates were opportunistic pathogens, including Klebsiella spp. (10.3%), Enterococcus spp. (11.3%), Acinetobacter spp. (19.6%), Escherichia spp. (12.4%), Shigella spp. (17.5%), Stenotrophomonas spp. (10.3%) and Wautersiella spp. (9.3%). Moreover, blaKPC-2 genes were identified for the first time in Paenibacillus spp. isolates (an indigenous bacteria), indicating an increased risk of horizontal transfer between clinical pathogens and environmental bacteria. Indeed, a conjugation experiment demonstrated transfer of the blaKPC-2 gene to an E.coli J53 strain from a Klebsiella strain isolated from the WWTP. To our knowledge, this is the first study to obtain Paenibacillus spp. isolates carrying the carbapenemase gene and to quantify the abundance of carbapenemase genes in the environment. PMID:27227329

Whole-genome typing and characterization of blaVIM19-harbouring ST383 Klebsiella pneumoniae by PFGE, whole-genome mapping and WGS.

PubMed

Sabirova, Julia S; Xavier, Basil Britto; Coppens, Jasmine; Zarkotou, Olympia; Lammens, Christine; Janssens, Lore; Burggrave, Ronald; Wagner, Trevor; Goossens, Herman; Malhotra-Kumar, Surbhi

2016-06-01

We utilized whole-genome mapping (WGM) and WGS to characterize 12 clinical carbapenem-resistant Klebsiella pneumoniae strains (TGH1-TGH12). All strains were screened for carbapenemase genes by PCR, and typed by MLST, PFGE (XbaI) and WGM (AflII) (OpGen, USA). WGS (Illumina) was performed on TGH8 and TGH10. Reads were de novo assembled and annotated [SPAdes, Rapid Annotation Subsystem Technology (RAST)]. Contigs were aligned directly, and after in silico AflII restriction, with corresponding WGMs (MapSolver, OpGen; BioNumerics, Applied Maths). All 12 strains were ST383. Of the 12 strains, 11 were carbapenem resistant, 7 harboured blaKPC-2 and 11 harboured blaVIM-19. Varying the parameters for assigning WGM clusters showed that these were comparable to STs and to the eight PFGE types or subtypes (difference of three or more bands). A 95% similarity coefficient assigned all 12 WGMs to a single cluster, whereas a 99% similarity coefficient (or ≥10 unmatched-fragment difference) assigned the 12 WGMs to eight (sub)clusters. Based on a difference of three or more bands between PFGE profiles, the Simpson's diversity indices (SDIs) of WGM (0.94, Jackknife pseudo-values CI: 0.883-0.996) and PFGE (0.93, Jackknife pseudo-values CI: 0.828-1.000) were similar (P = 0.649). However, the discriminatory power of WGM was significantly higher (SDI: 0.94, Jackknife pseudo-values CI: 0.883-0.996) than that of PFGE profiles typed on a difference of seven or more bands (SDI: 0.53, Jackknife pseudo-values CI: 0.212-0.849) (P = 0.007). This study demonstrates the application of WGM to understanding the epidemiology of hospital-associated K. pneumoniae. Utilizing a combination of WGM and WGS, we also present here the first longitudinal genomic characterization of the highly dynamic carbapenem-resistant ST383 K. pneumoniae clone that is rapidly gaining importance in Europe. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Linkage of ciprofloxacin resistance with a single genotypic cluster of Klebsiella pneumoniae.

PubMed

Dashti, A A; Paton, R; Amyes, S G B

2006-01-01

The objective of this study was to examine the epidemiology of ciprofloxacin-resistant, extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae strains. Sixty-nine unique patient isolates of K. pneumoniae isolated from a variety of clinical specimens submitted to the clinical bacteriology laboratories of The Royal Infirmary of Edinburgh and associated General Practices were identified and susceptibility testing was performed with the Vitek system. Strains flagged as ESBL-positive by the Vitek system were subjected to isoelectric focusing. The results suggested that all 69 isolates harboured at least one ESBL, which was later confirmed by polymerase chain reaction (PCR) with bla(TEM) and/or bla(SHV) primers. The purified PCR product was subjected to automated sequencing and the results were compared with the BLAST online search engine. Of the 69 isolates, 32 (46.4%) were found to be resistant to ciprofloxacin, 11 (15.9%) were intermediate and 26 (37.7%) were sensitive. To investigate the epidemiological relationship between the ciprofloxacin-resistant ESBL-positive strains, pulsed-field gel electrophoresis (PFGE) was performed. Rapidest software was used to calculate the genetic distance by the Nei distance method. PFGE analysis indicated that the clinical isolates belonged to four distinct genotype clusters (Groups A, B, C and D); each group or cluster was homogeneous or compact with respect to certain characteristics. Group A consisted of 25 isolates, group B of 3 isolates and Groups C and D of 2 isolates each. These results indicate that the spread of resistance is largely as a result of the dissemination of a single clonal strain. PCR was used to amplify the gyrA and parC genes from genomic DNA of the ciprofloxacin-resistant isolates. The amplified product was sent for analysis by automated DNA sequencing and the resulting DNA sequences were compared with the gyrA gene of K. pneumoniae. The sequencing results demonstrated that alteration of the GyrA subunit of DNA gyrase at amino acid 83 and/or amino acid 87 plays a central role in conferring high-level quinolone resistance in K. pneumoniae possessing ESBLs.

[Distribution and drug resistance of the pathogenic bacteria from sputum specimens of 1 125 children with tracheo bronchial foreign bodies].

PubMed

Wen, Xin; Su, Jinzhu; Cui, Li; Wang, Juan; Zuo, Lujie

2015-02-01

To analyze the distribution and drug susceptibility of the pathogenic bacteria in the airway secretions in children with tracheobronchial foreign bodies so as to assist physicians in clinical prescription. Sputum specimens of 1 125 children with tracheobronchial foreign bodies were collected in removal of the foreign bodies by rigid bronchoscope, and the drug susceptibility test was performed. Pathogenic bacteria were detected in 218 (19.4%) of 1 125 sputum specimens. Among the pathogenic bacteria, 126 (57.79%) strains were gram-negative bacilli, consisting of 76 (34.86%) strains of Haemophilus influenzae, 10 (4.59%) strains of Escherichia coli, 7 (3.21%) strains of Sewer enterobacter, 7 (3.21%) strains of Pseudomonas aeruginosa, and 6 (2.75%) strains of Klebsiella bacillus; and 92 (42.21%) strains were gram-positive bacilli, consisting of 80 (36.69%) strains of Streptococcus pneumonia and 10 (4.59%) strains of Escherichia coli. Most of detected gram-negative bacilli were highly sensitive to cefepime, ceftazidine, imipenem and amikacin, no strains were resistant to meropenem and ciprofloxacin. None of the detected gram-positive bacilli were resistant to cefepime, vancomycin, levofloxacin and teicoplanin. The Haemophilus influenzae of gram-negative bacilli and the Streptococcus pneumonia of gram-positive bacilli are the main pathogenic bacteria existing in the airway secretions of children with tracheobronchial foreign bodies. The Haemophilus influenzae were highly sensitive to cephalosporin, imipenem and amikacin, and the Streptococcus pneumonia to cefepime, vancomycin, levofloxacin and teicoplanin.

Synthesis, evaluation and molecular docking studies of amino acid derived N-glycoconjugates as antibacterial agents.

PubMed

Baig, Noorullah; Singh, Rajnish Prakash; Chander, Subhash; Jha, Prabhat Nath; Murugesan, Sankaranarayanan; Sah, Ajay K

2015-12-01

Six amino acid derived N-glycoconjugates of d-glucose were synthesized, characterized and tested for antibacterial activity against G(+)ve (Bacillus cereus) as well as G(-)ve (Escherichia coli and Klebsiella pneumoniae) bacterial strains. All the tested compounds exhibited moderate to good antibacterial activity against these bacterial strains. The results were compared with the antibacterial activity of standard drug Chloramphenicol, where results of A5 (Tryptophan derived glycoconjugates) against E. coli and A4 (Isoleucine derived glycoconjugates) against K. pneumoniae bacterial strains are comparable with the standard drug molecule. In silico docking studies were also performed in order to understand the mode of action and binding interactions of these molecules. The docking studies revealed that, occupation of compound A5 at the ATP binding site of subunit GyrB (DNA gyrase, PDB ID: 3TTZ) via hydrophobic and hydrogen bonding interactions may be the reason for its significant in vitro antibacterial activity. Copyright © 2015 Elsevier Inc. All rights reserved.

Tetrachloromethane-Degrading Bacterial Enrichment Cultures and Isolates from a Contaminated Aquifer.

PubMed

Penny, Christian; Gruffaz, Christelle; Nadalig, Thierry; Cauchie, Henry-Michel; Vuilleumier, Stéphane; Bringel, Françoise

2015-07-02

The prokaryotic community of a groundwater aquifer exposed to high concentrations of tetrachloromethane (CCl₄) for more than three decades was followed by terminal restriction fragment length polymorphism (T-RFLP) during pump-and-treat remediation at the contamination source. Bacterial enrichments and isolates were obtained under selective anoxic conditions, and degraded 10 mg·L(-1) CCl₄, with less than 10% transient formation of chloroform. Dichloromethane and chloromethane were not detected. Several tetrachloromethane-degrading strains were isolated from these enrichments, including bacteria from the Klebsiella and Clostridium genera closely related to previously described CCl₄ degrading bacteria, and strain TM1, assigned to the genus Pelosinus, for which this property was not yet described. Pelosinus sp. TM1, an oxygen-tolerant, Gram-positive bacterium with strictly anaerobic metabolism, excreted a thermostable metabolite into the culture medium that allowed extracellular CCl₄ transformation. As estimated by T-RFLP, phylotypes of CCl₄-degrading enrichment cultures represented less than 7%, and archaeal and Pelosinus strains less than 0.5% of the total prokaryotic groundwater community.

Genetic background of novel sequence types of CTX-M-8- and CTX-M-15-producing Escherichia coli and Klebsiella pneumoniae from public wastewater treatment plants in São Paulo, Brazil.

PubMed

Dropa, Milena; Lincopan, Nilton; Balsalobre, Livia C; Oliveira, Danielle E; Moura, Rodrigo A; Fernandes, Miriam Rodriguez; da Silva, Quézia Moura; Matté, Glavur R; Sato, Maria I Z; Matté, Maria H

2016-03-01

The release of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae to the environment is a public health issue worldwide. The aim of this study was to investigate the genetic background of genes encoding ESBLs in wastewater treatment plants (WWTPs) in São Paulo, southeastern Brazil. In 2009, during a local surveillance study, seven ESBL-producing Enterobacteriaceae strains were recovered from five WWTPs and screened for ESBL genes and mobile genetic elements. Multilocus sequence typing (MLST) was carried out, and wild plasmids were transformed into electrocompetent Escherichia coli. S1-PFGE technique was used to verify the presence of high molecular weight plasmids in wild-type strains and in bla ESBL-containing E. coli transformants. Strains harbored bla CTX-M-8, bla CTX-M-15, and/or bla SHV-28. Sequencing results showed that bla CTX-M-8 and bla CTX-M-15 genes were associated with IS26. MLST revealed new sequence types for E. coli (ST4401, ST4402, ST4403, and ST4445) and Klebsiella pneumoniae (ST1574), except for one K. pneumoniae from ST307 and Enterobacter cloacae from ST131. PCR and S1-PFGE results showed CTX-M-producing E. coli transformants carried heavy plasmids sizing 48.5-209 kb, which belonged to IncI1, IncF, and IncM1 incompatibility groups. This is the first report of CTX-M-8 and SHV-28 enzymes in environmental samples, and the present results demonstrate the plasmid-mediated spread of CTX-M-encoding genes through five WWTPs in São Paulo, Brazil, suggesting WWTPs are hotspots for the transfer of ESBL genes and confirming the urgent need to improve the management of sewage in order to minimize the dissemination of resistance genes to the environment.

In Vivo Pharmacokinetics and Pharmacodynamics of ZTI-01 (Fosfomycin for Injection) in the Neutropenic Murine Thigh Infection Model against Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa.

PubMed

Lepak, Alexander J; Zhao, Miao; VanScoy, Brian; Taylor, Daniel S; Ellis-Grosse, Evelyn; Ambrose, Paul G; Andes, David R

2017-06-01

Fosfomycin is a broad-spectrum agent with activity against Gram-positive and Gram-negative bacteria, including drug-resistant strains, such as extended-spectrum-beta-lactamase (ESBL)-producing and carbapenem-resistant (CR) Gram-negative rods. In the present study, the pharmacokinetic/pharmacodynamic (PK/PD) activity of ZTI-01 (fosfomycin for injection) was evaluated in the neutropenic murine thigh infection model against 5 Escherichia coli , 3 Klebsiella pneumoniae , and 2 Pseudomonas aeruginosa strains, including a subset with ESBL and CR phenotypes. The pharmacokinetics of ZTI-01 were examined in mice after subcutaneous administration of 3.125, 12.5, 50, 200, 400, and 800 mg/kg of body weight. The half-life ranged from 0.51 to 1.1 h, area under the concentration-time curve (AUC 0-∞ ) ranged from 1.4 to 87 mg · h/liter, and maximum concentrations ranged from 0.6 to 42.4 mg/liter. Dose fractionation demonstrated the AUC/MIC ratio to be the PK/PD index most closely linked to efficacy ( R 2 = 0.70). Net stasis and bactericidal activity were observed against all strains. Net stasis was observed at 24-h AUC/MIC ratio values of 24, 21, and 15 for E. coli , K. , pneumoniae and P. aeruginosa , respectively. For the Enterobacteriaceae group, stasis was noted at mean 24-h AUC/MIC ratio targets of 23 and 1-log kill at 83. Survival in mice infected with E. coli 145 was maximal at 24-h AUC/MIC ratio exposures of 9 to 43, which is comparable to the stasis exposures identified in the PK/PD studies. These results should prove useful for the design of clinical dosing regimens for ZTI-01 in the treatment of serious infections due to Enterobacteriaceae and Pseudomonas . Copyright © 2017 American Society for Microbiology.

Clinical and microbiologic characteristics of adult patients with recurrent bacteraemia caused by extended-spectrum β-lactamase-producing Escherichia coli or Klebsiella pneumoniae.

PubMed

Lee, C-H; Su, L-H; Chen, F-J; Tang, Y-F; Chien, C-C; Liu, J-W

2015-12-01

The characteristics of patients with recurrent bacteraemia caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli or Klebsiella pneumoniae (EK) are rarely described. Flomoxef belongs to the cephamycins group and demonstrates in vitro activity against ESBL-producing organisms. Whether flomoxef may be used for the treatment of such infections remains controversial. This retrospective case-control study enrolled adult patients who had bacteraemia caused by ESBL-EK during 2005-2011. Case patients were those who had more than one episode of ESBL-EK bacteraemia. Controls were those who were matched for age and interval time of blood sampling and had only one episode of ESBL-EK bacteraemia with subsequent bacteraemia episodes caused by other non-ESBL-EK bacteria. Pulsed-field gel electrophoresis and microbiologic profiles of the initial and subsequent ESBL-EK isolates were analysed. During the study period, 424 patients were found to have at least one positive blood culture after the first ESBL-EK bacteraemia episode, and 67 (15.8%) had a second episode of ESBL-EK bacteraemia. Bacteraemia resulting from vascular catheter-related infection (odds ratio, 3.24; 95% confidence interval, 1.31-8.05), and definitive therapy with flomoxef (odds ratio, 2.99; 95% confidence interval, 1.10-8.15) were both independent risk factors for the recurrence. Among the 56 patients with available ESBL-EK isolates for analysis, 38 (67.8%) were infected by genetically similar strains. In three of these 38 recurrent ESBL-EK bacteraemia cases caused by an identical strain, the minimum inhibitory concentrations of carbapenem for the subsequent K. pneumoniae isolates were fourfold or higher than the initial isolates. Recurrent bacteraemia was not uncommon in our patients with ESBL-EK bacteraemia, and most of the episodes were caused by identical strains. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Antibacterial effect evaluation of moxalactam against extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae with in vitro pharmacokinetics/pharmacodynamics simulation

PubMed Central

Yu, Wei; Niu, Tianshui; Xiao, Tingting; Zhang, Jing; Xiao, Yonghong

2018-01-01

Objectives The aim of this study was to evaluate the bactericidal effects of moxalactam (MOX), cefotaxime (CTX), and cefoperazone/sulbactam (CFZ/SBT) against extended-spectrum β-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae, using an in vitro pharmacokinetics (PK)/pharmacodynamics model. Methods Two clinical ESBL-producing strains (blaCTX-M-15 positive E. coli 3376 and blaCTX-M-14 positive K. pneumoniae 2689) and E. coli American Type Culture Collection (ATCC)25922 were used in the study. The PK Auto Simulation System 400 was used to simulate the human PK procedures after intravenous administration of different doses of MOX, CTX, and CFZ/SBT. Bacterial growth recovery time (RT) and the area between the control growth curve and bactericidal curves (IE) were employed to assess the antibacterial efficacies of all the agents. Results The minimum inhibitory concentrations of MOX, CTX, and CFZ/SBT against E. coli ATCC25922, 3376, and 2689 strains were 0.5, 0.5, 0.25; 0.06, >256, 256; and 0.5/0.5, 16/16, 32/32 mg/L. All the agents demonstrated outstanding bactericidal effects against E. coli ATCC25922 (RT >24 h and IE >120 log10 CFU/mL·h−1) with simulating PK procedures, especially in the multiple dose administration models. Against ESBL producers, CTX and CFZ/SBT displayed only weak bactericidal effects, and subsequent regrowth was evident. MOX exhibited potent antibacterial activity against all the strains tested. The values of effective parameters of MOX were much higher than those of CTX and CFZ/SBT (the bacterial RTs with the 3 agents were >24, <4, and <13 h, and the IEs were >110, <10, and <60 log10 CFU/mL·h−1, respectively). Conclusion MOX demonstrated excellent bactericidal effect, which is worthy of further exploration to serve as an alternative therapeutic agent against ESBL-producing Enterobacteriaceae. PMID:29391816

Klebsiella pneumoniae Carbapenemase (KPC)-Producing K. pneumoniae at a Single Institution: Insights into Endemicity from Whole-Genome Sequencing

PubMed Central

Stoesser, Nicole; Sheppard, Anna E.; Pankhurst, Louise; Giess, Adam; Yeh, Anthony J.; Didelot, Xavier; Turner, Stephen D.; Sebra, Robert; Kasarskis, Andrew; Peto, Tim; Crook, Derrick; Sifri, Costi D.

2015-01-01

The global emergence of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) multilocus sequence type ST258 is widely recognized. Less is known about the molecular and epidemiological details of non-ST258 K. pneumoniae in the setting of an outbreak mediated by an endemic plasmid. We describe the interplay of blaKPC plasmids and K. pneumoniae strains and their relationship to the location of acquisition in a U.S. health care institution. Whole-genome sequencing (WGS) analysis was applied to KPC-Kp clinical isolates collected from a single institution over 5 years following the introduction of blaKPC in August 2007, as well as two plasmid transformants. KPC-Kp from 37 patients yielded 16 distinct sequence types (STs). Two novel conjugative blaKPC plasmids (pKPC_UVA01 and pKPC_UVA02), carried by the hospital index case, accounted for the presence of blaKPC in 21/37 (57%) subsequent cases. Thirteen (35%) isolates represented an emergent lineage, ST941, which contained pKPC_UVA01 in 5/13 (38%) and pKPC_UVA02 in 6/13 (46%) cases. Seven (19%) isolates were the epidemic KPC-Kp strain, ST258, mostly imported from elsewhere and not carrying pKPC_UVA01 or pKPC_UVA02. Using WGS-based analysis of clinical isolates and plasmid transformants, we demonstrate the unexpected dispersal of blaKPC to many non-ST258 lineages in a hospital through spread of at least two novel blaKPC plasmids. In contrast, ST258 KPC-Kp was imported into the institution on numerous occasions, with other blaKPC plasmid vectors and without sustained transmission. Instead, a newly recognized KPC-Kp strain, ST941, became associated with both novel blaKPC plasmids and spread locally, making it a future candidate for clinical persistence and dissemination. PMID:25561339

[Spectrum and drug sensitivity of pathogenic bacteria in children with nephrotic syndrome complicated by urinary tract infection: an analysis of 97 cases].

PubMed

Song, Shao-Na; Zhang, Bi-Li; Wang, Wen-Hong; Zhang, Xuan

2012-09-01

To investigate the spectrum and drug sensitivity of pathogenic bacteria in children with nephrotic syndrome (NS) complicated by urinary tract infection (UTI). A retrospective analysis was performed on the spectrum and drug sensitivity of pathogenic bacteria in 97 children with NS complicated by UTI, who hospitalized from January to December, 2011. The incidence of UTI in children with NS was 36.5%. It was significantly more common in children with recurrent NS than in those with primary NS (44.0% vs 31.9%; P<0.05). These cases mainly presented with asymptomatic bacteriuria. Enterococcus was the most common pathogenic bacteria (50.5%), including Enterococcus faecium (29.4%) and Enterococcus faecalis (21.1%), followed by Gram-negative bacteria, such as Escherichia coli (15.6%) and Klebsiella pneumoniae (14.7%). Enterococcus was highly sensitive to nitrofurantoin, vacomycin and linezolid, but was highly resistant to tetracycline and moxifloxacin. More multi-resistant strains were detected in Enterococcus faecium than in Enterococcus faecalis (72% vs 17%; P<0.05). Escherichia coli and Klebsiella pneumoniae were highly sensitive to amikacin, imipenem and piperacillin/tazobactam. Of the Gram-negative bacteria, 25% produced extended spectrum β-lactamases (ESBLs). ESBLs-producing bacteria had 100% sensitivity to imipenem, amikacin and piperacillin/tazobactam but were highly resistant to ampicillin, cefazolin and ceftriaxone. Children with recurrent NS are more susceptible to UTI than those with primary NS. Enterococcus is becoming major pathogenic bacteria for UTI in children with NS and has relatively high drug resistance, and most strains of Enterococcus faecium are multi-resistant.

Genomic analysis of diversity, population structure, virulence, and antimicrobial resistance in Klebsiella pneumoniae, an urgent threat to public health

PubMed Central

Holt, Kathryn E.; Wertheim, Heiman; Zadoks, Ruth N.; Baker, Stephen; Whitehouse, Chris A.; Dance, David; Jenney, Adam; Connor, Thomas R.; Hsu, Li Yang; Severin, Juliëtte; Brisse, Sylvain; Cao, Hanwei; Wilksch, Jonathan; Gorrie, Claire; Schultz, Mark B.; Edwards, David J.; Nguyen, Kinh Van; Nguyen, Trung Vu; Dao, Trinh Tuyet; Mensink, Martijn; Minh, Vien Le; Nhu, Nguyen Thi Khanh; Schultsz, Constance; Kuntaman, Kuntaman; Newton, Paul N.; Moore, Catrin E.; Strugnell, Richard A.; Thomson, Nicholas R.

2015-01-01

Klebsiella pneumoniae is now recognized as an urgent threat to human health because of the emergence of multidrug-resistant strains associated with hospital outbreaks and hypervirulent strains associated with severe community-acquired infections. K. pneumoniae is ubiquitous in the environment and can colonize and infect both plants and animals. However, little is known about the population structure of K. pneumoniae, so it is difficult to recognize or understand the emergence of clinically important clones within this highly genetically diverse species. Here we present a detailed genomic framework for K. pneumoniae based on whole-genome sequencing of more than 300 human and animal isolates spanning four continents. Our data provide genome-wide support for the splitting of K. pneumoniae into three distinct species, KpI (K. pneumoniae), KpII (K. quasipneumoniae), and KpIII (K. variicola). Further, for K. pneumoniae (KpI), the entity most frequently associated with human infection, we show the existence of >150 deeply branching lineages including numerous multidrug-resistant or hypervirulent clones. We show K. pneumoniae has a large accessory genome approaching 30,000 protein-coding genes, including a number of virulence functions that are significantly associated with invasive community-acquired disease in humans. In our dataset, antimicrobial resistance genes were common among human carriage isolates and hospital-acquired infections, which generally lacked the genes associated with invasive disease. The convergence of virulence and resistance genes potentially could lead to the emergence of untreatable invasive K. pneumoniae infections; our data provide the whole-genome framework against which to track the emergence of such threats. PMID:26100894

Global Dissemination of Carbapenemase-Producing Klebsiella pneumoniae: Epidemiology, Genetic Context, Treatment Options, and Detection Methods

PubMed Central

Lee, Chang-Ro; Lee, Jung Hun; Park, Kwang Seung; Kim, Young Bae; Jeong, Byeong Chul; Lee, Sang Hee

2016-01-01

The emergence of carbapenem-resistant Gram-negative pathogens poses a serious threat to public health worldwide. In particular, the increasing prevalence of carbapenem-resistant Klebsiella pneumoniae is a major source of concern. K. pneumoniae carbapenemases (KPCs) and carbapenemases of the oxacillinase-48 (OXA-48) type have been reported worldwide. New Delhi metallo-β-lactamase (NDM) carbapenemases were originally identified in Sweden in 2008 and have spread worldwide rapidly. In this review, we summarize the epidemiology of K. pneumoniae producing three carbapenemases (KPCs, NDMs, and OXA-48-like). Although the prevalence of each resistant strain varies geographically, K. pneumoniae producing KPCs, NDMs, and OXA-48-like carbapenemases have become rapidly disseminated. In addition, we used recently published molecular and genetic studies to analyze the mechanisms by which these three carbapenemases, and major K. pneumoniae clones, such as ST258 and ST11, have become globally prevalent. Because carbapenemase-producing K. pneumoniae are often resistant to most β-lactam antibiotics and many other non-β-lactam molecules, the therapeutic options available to treat infection with these strains are limited to colistin, polymyxin B, fosfomycin, tigecycline, and selected aminoglycosides. Although, combination therapy has been recommended for the treatment of severe carbapenemase-producing K. pneumoniae infections, the clinical evidence for this strategy is currently limited, and more accurate randomized controlled trials will be required to establish the most effective treatment regimen. Moreover, because rapid and accurate identification of the carbapenemase type found in K. pneumoniae may be difficult to achieve through phenotypic antibiotic susceptibility tests, novel molecular detection techniques are currently being developed. PMID:27379038

Effective immunosuppression with dexamethasone phosphate in the Galleria mellonella larva infection model resulting in enhanced virulence of Escherichia coli and Klebsiella pneumoniae.

PubMed

Torres, Miquel Perez; Entwistle, Frances; Coote, Peter J

2016-08-01

The aim was to evaluate whether immunosuppression with dexamethasone 21-phosphate could be applied to the Galleria mellonella in vivo infection model. Characterised clinical isolates of Escherichia coli or Klebsiella pneumoniae were employed, and G. mellonella larvae were infected with increasing doses of each strain to investigate virulence in vivo. Virulence was then compared with larvae exposed to increasing doses of dexamethasone 21-phosphate. The effect of dexamethasone 21-phosphate on larval haemocyte phagocytosis in vitro was determined via fluorescence microscopy and a burden assay measured the growth of infecting bacteria inside the larvae. Finally, the effect of dexamethasone 21-phosphate treatment on the efficacy of ceftazidime after infection was also noted. The pathogenicity of K. pneumoniae or E. coli in G. mellonella larvae was dependent on high inoculum numbers such that virulence could not be attributed specifically to infection by live bacteria but also to factors associated with dead cells. Thus, for these strains, G. mellonella larvae do not constitute an ideal infection model. Treatment of larvae with dexamethasone 21-phosphate enhanced the lethality induced by infection with E. coli or K. pneumoniae in a dose- and inoculum size-dependent manner. This correlated with proliferation of bacteria in the larvae that could be attributed to dexamethasone inhibiting haemocyte phagocytosis and acting as an immunosuppressant. Notably, prior exposure to dexamethasone 21-phosphate reduced the efficacy of ceftazidime in vivo. In conclusion, demonstration of an effective immunosuppressant regimen can improve the specificity and broaden the applications of the G. mellonella model to address key questions regarding infection.

In vitro selection of resistance in Escherichia coli and Klebsiella spp. at in vivo fluoroquinolone concentrations

PubMed Central

2010-01-01

Background Fluoroquinolones are potent antimicrobial agents used for the treatment of a wide variety of community- and nosocomial- infections. However, resistance to fluoroquinolones in Enterobacteriaceae is increasingly reported. Studies assessing the ability of fluoroquinolones to select for resistance have often used antimicrobial concentrations quite different from those actually acquired at the site of infection. The present study compared the ability to select for resistance of levofloxacin, ciprofloxacin and prulifloxacin at concentrations observed in vivo in twenty strains of Escherichia coli and Klebsiella spp. isolated from patients with respiratory and urinary infections. The frequencies of spontaneous single-step mutations at plasma peak and trough antibiotic concentrations were calculated. Multi-step selection of resistance was evaluated by performing 10 serial cultures on agar plates containing a linear gradient from trough to peak antimicrobial concentrations, followed by 10 subcultures on antibiotic-free agar. E. coli resistant strains selected after multi-step selection were characterized for DNA mutations by sequencing gyrA, gyrB, parC and parE genes. Results Frequencies of mutations for levofloxacin and ciprofloxacin were less than 10-11 at peak concentration, while for prulifloxacin they ranged from <10-11 to 10-5. The lowest number of resistant mutants after multistep selection was selected by levofloxacin followed by ciprofloxacin and prulifloxacin. Both ciprofloxacin- and prulifloxacin-resistant mutants presented mutations in gyrA and parC, while levofloxacin resistance was found associated only to mutations in gyrA. Conclusions Among the tested fluoroquinolones, levofloxacin was the most capable of limiting the occurrence of resistance. PMID:20409341

Physical and anti-microbial characteristics of carbon nanoparticles prepared from lamp soot

NASA Astrophysics Data System (ADS)

Mohanty, B.; Verma, Anita K.; Claesson, P.; Bohidar, H. B.

2007-11-01

Soot originating from the burning of butter and mustard oil in a lamp with a cotton wick was collected on a brass plate and dispersed in water and carbon tetrachloride (CCl4) as naked, and as Gum Arabic (GA, a anionic polyelectrolyte)-coated nanoparticles in water. They were physically characterized, and their anti-bacterial activities were probed on gram positive and negative bacterial colonies. TEM data revealed the presence of 35-55 nm diameter spherical carbon nanoparticles in water and CCl4. The dynamic light scattering determined the average hydrodynamic diameter for the same samples, which was found to be ≈100 nm (in CCl4) and ≈240 nm (in water), implying the packing of these nanoparticles into clusters. GA-coated particles yielded stable suspensions in water, but the clusters were almost the same in size (≈250 nm). The zeta potential distributions of the naked and the GA-coated nanoparticles were found to be unimodal and bimodal, respectively, with both yielding mean zeta potential values nearly equal to zero. Results of energy-dispersive x-ray analysis (EDAX) confirmed the absence of toxic metallic elements inside the specimen. X-ray diffraction study confirmed the presence of amorphous as well as graphitized carbon in these nanostructures. The anti-microbial activities in terms of growth inhibition for the carbon nanoparticles against Staphylococcus aureus, ATCC 13709 (native strain) and Klebsiella pneumonia ATCC 29655 (native strain) were assayed in agar gel. In vitro testing revealed significant anti-microbial activity against Klebsiella pneumonia, but carbon nanoparticles were unable to kill Staphylococcus aureus.

Emerging Trends of Bloodstream Infections: A Six-Year Study at a Paediatric Tertiary Care Hospital in Kabul.

PubMed

Tariq, Tariq Mahmud; Rasool, Esmatullah

2016-11-01

To determine the frequency of pathogens causing bloodstream infections and evaluate their trends and antibiogram patterns among in-patients in a paediatric tertiary care centre. Descriptive study. French Medical Institute for Mothers and Children (FMIC), Kabul, Afghanistan in two phases, from January 2010 to December 2015. Results of blood cultures from suspected cases of sepsis admitted in the FMIC, from January 2010 to December 2012 (Period-1), and from January 2013 to December 2015 (Period-2) were completed. Standard microbiological methods were followed for blood culture and antibiotic sensitivity testing. Out of total 1,040 cases of culture proven sepsis, 528 (50.77%) Gram-negative bacilli (GNB), 474 (45.58%) Gram-positive cocci (GPC), and 38 (3.65%) Candida species were isolated during the entire study period. Out of 528 GNB isolates, 373 (70.64%) belonged to the Enterobacteriaceae and 155 (29.36%) were non-fermenters. Among Enterobacteriaceae, 168 (31.82%) were Klebsiella species (K. pneumoniae=124, K. oxytoca=44), 70 (13.26%) were Enterobacter species (E. cloacae=52, E. aerogenes=18), 65 (12.31%) were E. coli, 37 (7.01%) were Serratia marcescens and 31 (5.87%) were others. Out of 155 non-fermenters, 88 (16.67%) were Pseudomonas aeruginosa, 39 (7.39%) were Burkholderia cepacia and 18 (3.41%) were Stenotrophomonas maltophilia. There was a drop in the frequency of Enterobacteriaceae from 85% in Period-1 to 58.68% in Period-2. There was an increase in the frequency of nonfermenters from 15% to 41.32%, particularly 18 new cases of sepsis caused by Stenotrophomonas maltophilia during Period-2. Among GPC, there was an overall rise of 16.14% in the prevalence of Staphylococcus epidermidis during Period-2 and a drop of 9.64% in the frequency of Staphylococcus aureus during Period-2. The majority of Gram-negative isolates were multidrug-resistant to commonly used antibiotics. However, most of the isolates were sensitive to amikacin and imipenem (except S. maltophilia). The frequency of those producing ESBL reduced by 11.22% during the Period-2. Among Gram-positive cocci, the pattern of antibiogram did not show a significant change during both periods, and majority remained resistant to commonly used antibiotics. All Staphylococci were sensitive to vancomycin but resistant to penicillin. There was a substantial decline of 18.87% in the frequency of Methicillin-resistant Staphylococci (MRSA/MRSE) during Period-2. Staphylococci and Klebsiellae remain the most important bacteria responsible for bloodstream infections in a tertiary healthcare facility in Kabul. Yet, there has been an increase in the prevalence of Pseudomonas and Burkholderia cepacia. Moreover, Stenotrophomonas maltophilia emerged as a new hospital acquired pathogen. This study could possibly help in suggesting choices eluding the misuse of appropriate antibiotics.

Enhancement of electricity production in a mediatorless air-cathode microbial fuel cell using Klebsiella sp. IR21.

PubMed

Lee, Yun-Yeong; Kim, Tae Gwan; Cho, Kyung-Suk

2016-06-01

A novel dissimilatory iron-reducing bacteria, Klebsiella sp. IR21, was isolated from the anode biofilm of an MFC reactor. Klebsiella sp. IR21 reduced 27.8 % of ferric iron to ferrous iron demonstrating that Klebsiella sp. IR21 has electron transfer ability. Additionally, Klebsiella sp. IR21 generated electricity forming a biofilm on the anode surface. When a pure culture of Klebsiella sp. IR21 was supplied into a single chamber, air-cathode MFC fed with a mixture of glucose and acetate (500 mg L(-1) COD), 40-60 mV of voltage (17-26 mA m(-2) of current density) was produced. Klebsiella sp. IR21 was also utilized as a biocatalyst to improve the electrical performance of a conventional MFC reactor. A single chamber, air-cathode MFC was fed with reject wastewater (10,000 mg L(-1) COD) from a H2 fermentation reactor. The average voltage, current density, and power density were 142.9 ± 25.74 mV, 60.5 ± 11.61 mA m(-2), and 8.9 ± 3.65 mW m(-2), respectively, in the MFC without inoculation of Klebsiella sp. IR21. However, these electrical performances of the MFC were significantly increased to 204.7 ± 40.24 mV, 87.5 ± 17.20 mA m(-2), and 18.6 ± 7.23 mW m(-2), respectively, with inoculation of Klebsiella sp. IR21. The results indicate that Klebsiella sp. IR21 can be utilized as a biocatalyst for enhancement of electrical performance in MFC systems.

Draft Genome Sequences of Endophytic Isolates of Klebsiella variicola and Klebsiella pneumoniae Obtained from the Same Sugarcane Plant

PubMed Central

2018-01-01

ABSTRACT Endophytic Klebsiella variicola KvMx2 and Klebsiella pneumoniae KpMx1 isolates obtained from the same sugarcane stem were used for whole-genome sequencing. The genomes revealed clear differences in essential genes for plant growth, development, and detoxification, as well as nitrogen fixation, catalases, cellulases, and shared virulence factors described in the K. pneumoniae pathogen. PMID:29567733

Draft Genome Sequences of Endophytic Isolates of Klebsiella variicola and Klebsiella pneumoniae Obtained from the Same Sugarcane Plant.

PubMed

Reyna-Flores, Fernando; Barrios-Camacho, Humberto; Dantán-González, Edgar; Ramírez-Trujillo, José Augusto; Lozano Aguirre Beltrán, Luis Fernando; Rodríguez-Medina, Nadia; Garza-Ramos, Ulises; Suárez-Rodríguez, Ramón

2018-03-22

Endophytic Klebsiella variicola KvMx2 and Klebsiella pneumoniae KpMx1 isolates obtained from the same sugarcane stem were used for whole-genome sequencing. The genomes revealed clear differences in essential genes for plant growth, development, and detoxification, as well as nitrogen fixation, catalases, cellulases, and shared virulence factors described in the K. pneumoniae pathogen. Copyright © 2018 Reyna-Flores et al.

Unusual association of NDM-1 with KPC-2 and armA among Brazilian Enterobacteriaceae isolates

PubMed Central

Quiles, M.G.; Rocchetti, T.T.; Fehlberg, L.C.; Kusano, E.J.U.; Chebabo, A.; Pereira, R.M.G.; Gales, A.C.; Pignatari, A.C.C.

2014-01-01

We report the microbiological characterization of four New Delhi metallo-β-lactamase-1 (bla NDM-1)-producing Enterobacteriaceae isolated in Rio de Janeiro, Brazil. bla NDM-1 was located on a conjugative plasmid and was associated with Klebsiella pneumoniae carbapenemase-2 (bla KPC-2) or aminoglycoside-resistance methylase (armA), a 16S rRNA methylase not previously reported in Brazil, in two distinct strains of Enterobacter cloacae. Our results suggested that the introduction of bla NDM-1 in Brazil has been accompanied by rapid spread, since our isolates showed no genetic relationship. PMID:25466163

Kisameet Clay Exhibits Potent Antibacterial Activity against the ESKAPE Pathogens

PubMed Central

Behroozian, Shekooh; Svensson, Sarah L.

2016-01-01

ABSTRACT The ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens cause an increasing number of nosocomial infections worldwide since they escape the inhibitory effect of the available antibiotics and the immune response. Here, we report the broad-spectrum and potent antibacterial activity of Kisameet clay, a natural clay mineral from British Columbia, Canada, against a group of multidrug-resistant ESKAPE strains. The results suggest that this natural clay might be developed as a therapeutic option for the treatment of serious infections caused by these important pathogens. PMID:26814180

Discovery of MK-7655, a β-lactamase inhibitor for combination with Primaxin®

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blizzard, Timothy A.; Chen, Helen; Kim, Seongkon

2014-02-01

β-Lactamase inhibitors with a bicyclic urea core and a variety of heterocyclic side chains were prepared and evaluated as potential partners for combination with imipenem to overcome class A and C β-lactamase mediated antibiotic resistance. The piperidine analog 3 (MK-7655) inhibited both class A and C β-lactamases in vitro. It effectively restored imipenem’s activity against imipenem-resistant Pseudomonas and Klebsiella strains at clinically achievable concentrations. A combination of MK-7655 and Primaxin® is currently in phase II clinical trials for the treatment of Gram-negative bacterial infections.

Validation of Minim typing for fast and accurate discrimination of extended-spectrum, beta-lactamase-producing Klebsiella pneumoniae isolates in tertiary care hospital.

PubMed

Brhelova, Eva; Kocmanova, Iva; Racil, Zdenek; Hanslianova, Marketa; Antonova, Mariya; Mayer, Jiri; Lengerova, Martina

2016-09-01

Minim typing is derived from the multi-locus sequence typing (MLST). It targets the same genes, but sequencing is replaced by high resolution melt analysis. Typing can be performed by analysing six loci (6MelT), four loci (4MelT) or using data from four loci plus sequencing the tonB gene (HybridMelT). The aim of this study was to evaluate Minim typing to discriminate extended-spectrum beta-lactamase producing Klebsiella pneumoniae (ESBL-KLPN) isolates at our hospital. In total, 380 isolates were analyzed. The obtained alleles were assigned according to both the 6MelT and 4MelT typing scheme. In 97 isolates, the tonB gene was sequenced to enable HybridMelT typing. We found that the presented method is suitable to quickly monitor isolates of ESBL-KLPN; results are obtained in less than 2 hours and at a lower cost than MLST. We identified a local ESBL-KLPN outbreak and a comparison of colonizing and invasive isolates revealed a long term colonization of patients with the same strain. Copyright © 2016 Elsevier Inc. All rights reserved.

Syntrophic co-culture of Bacillus subtilis and Klebsiella pneumonia for degradation of kraft lignin discharged from rayon grade pulp industry.

PubMed

Yadav, Sangeeta; Chandra, Ram

2015-07-01

In order to search the degradability of kraft lignin, the potential bacterial strains Bacillus subtilis (GU193980) and Klebsiella pneumoniae (GU193981) were isolated, screened and applied in axenic and co-culture conditions. Results revealed that mixed culture showed better decolorization efficiency (80%) and reduction of pollution parameters (COD 73% and BOD 62%) than axenic culture. This indicated syntrophic growth of these two bacteria rather than any antagonistic effect. The HPLC analysis of degraded samples of kraft lignin has shown the reduction in peak area compared to control, suggesting that decrease in color intensity might be largely attributed to the degradation of lignin by isolated bacteria. Further, the GC-MS analysis showed that most of the compounds detected in control were diminished after bacterial treatment. Further, the seed germination test using Phaseolus aureus has supported the detoxification of bacterial decolorized kraft lignin for environmental safety. All these observations have revealed that the developed bacterial co-culture was capable for the effective degradation and decolorization of lignin containing rayon grade pulp mill wastewater for environmental safety. Copyright © 2015. Published by Elsevier B.V.

Antibacterial activity of Zuccagnia punctata Cav. ethanolic extracts.

PubMed

Zampini, Iris C; Vattuone, Marta A; Isla, Maria I

2005-12-01

The present study was conducted to investigate antibacterial activity of Zuccagnia punctata ethanolic extract against 47 strains of antibiotic-resistant Gram-negative bacteria and to identify bioactive compounds. Inhibition of bacterial growth was investigated using agar diffusion, agar macrodilution, broth microdilution and bioautographic methods. Zuccagnia punctata extract was active against all assayed bacteria (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter cloacae, Serratia marcescens, Morganella morganii, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia) with minimal inhibitory concentration (MIC) values ranging from 25 to 200 microg/mL. Minimal bactericidal concentration (MBC) values were identical or two-fold higher than the corresponding MIC values. Contact bioautography, indicated that Zuccagnia punctata extracts possess one major antibacterial component against Pseudomonas aeruginosa and at least three components against. Klebsiella pneumoniae and Escherichia coli. Activity-guided fractionation of 1he ethanol extract on a silica gel column yielded a compound (2',4'-dihydroxychalcone), which exhibited strong antibacterial activity with MIC values between 0.10 and 1.00 microg/mL for Proteus mirabilis, Enterobacter cloacae, Serratia marcescens, Morganella morganii, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia. These values are lower than imipenem (0.25-16 microg/mL). Zuccagnia punctata might provide promising therapeutic agents against infections with multi-resistant Gram-negative bacteria.

Assembly of the Type II Secretion System such as Found in Vibrio cholerae Depends on the Novel Pilotin AspS

PubMed Central

Dunstan, Rhys A.; Heinz, Eva; Wijeyewickrema, Lakshmi C.; Pike, Robert N.; Purcell, Anthony W.; Evans, Timothy J.; Praszkier, Judyta; Robins-Browne, Roy M.; Strugnell, Richard A.; Korotkov, Konstantin V.; Lithgow, Trevor

2013-01-01

The Type II Secretion System (T2SS) is a molecular machine that drives the secretion of fully-folded protein substrates across the bacterial outer membrane. A key element in the machinery is the secretin: an integral, multimeric outer membrane protein that forms the secretion pore. We show that three distinct forms of T2SSs can be distinguished based on the sequence characteristics of their secretin pores. Detailed comparative analysis of two of these, the Klebsiella-type and Vibrio-type, showed them to be further distinguished by the pilotin that mediates their transport and assembly into the outer membrane. We have determined the crystal structure of the novel pilotin AspS from Vibrio cholerae, demonstrating convergent evolution wherein AspS is functionally equivalent and yet structurally unrelated to the pilotins found in Klebsiella and other bacteria. AspS binds to a specific targeting sequence in the Vibrio-type secretins, enhances the kinetics of secretin assembly, and homologs of AspS are found in all species of Vibrio as well those few strains of Escherichia and Shigella that have acquired a Vibrio-type T2SS. PMID:23326233

Influence of Soap Characteristics and Food Service Facility Type on the Degree of Bacterial Contamination of Open, Refillable Bulk Soaps.

PubMed

Schaffner, Donald W; Jensen, Dane; Gerba, Charles P; Shumaker, David; Arbogast, James W

2018-02-01

Concern has been raised regarding the public health risks from refillable bulk-soap dispensers because they provide an environment for potentially pathogenic bacteria to grow. This study surveyed the microbial quality of open refillable bulk soap in four different food establishment types in three states. Two hundred ninety-six samples of bulk soap were collected from food service establishments in Arizona, New Jersey, and Ohio. Samples were tested for total heterotrophic viable bacteria, Pseudomonas, coliforms and Escherichia coli, and Salmonella. Bacteria were screened for antibiotic resistance. The pH, solids content, and water activity of all soap samples were measured. Samples were assayed for the presence of the common antibacterial agents triclosan and parachlorometaxylenol. More than 85% of the soap samples tested contained no detectable microorganisms, but when a sample contained any detectable microorganisms, it was most likely contaminated at a very high level (∼7 log CFU/mL). Microorganisms detected in contaminated soap included Klebsiella oxytoca, Serratia liquefaciens, Shigella sonnei, Enterobacter gergoviae, Serratia odorifera, and Enterobacter cloacae. Twenty-three samples contained antibiotic-resistant organisms, some of which were resistant to two or more antibiotics. Every sample containing less than 4% solids had some detectable level of bacteria, whereas no samples with greater than 14% solids had detectable bacteria. This finding suggests the use of dilution and/or low-cost formulations as a cause of bacterial growth. There was a statistically significant difference ( P = 0.0035) between the fraction of bacteria-positive samples with no detected antimicrobial agent (17%) and those containing an antimicrobial agent (7%). Fast food operations and grocery stores were more likely to have detectable bacteria in bulk-soap samples compared with convenience stores ( P < 0.05). Our findings underscore the risk to public health from use of refillable bulk-soap dispensers in food service establishments.

Antimicrobial Resistance and Resistance Genes in Aerobic Bacteria Isolated from Pork at Slaughter.

PubMed

Li, Lili; Heidemann Olsen, Rikke; Ye, Lei; Yan, He; Nie, Qing; Meng, Hecheng; Shi, Lei

2016-04-01

The aim of this study was to investigate the phenotypic and genotypic antimicrobial resistance, integrons, and transferability of resistance markers in 243 aerobic bacteria recovered from pork at slaughter in the People's Republic of China. The organisms belonged to 22 genera of gram-negative bacteria (92.2%) and gram-positive bacteria (7.8%). High levels of resistance were detected to tetracycline, trimethoprim-sulfamethoxazole, and ampicillin (36.2 to 54.3%), and lower levels were detected to nitrofurantoin, cefotaxime, gentamicin, ciprofloxacin, and chloramphenicol (7.8 to 29.2%). Across species, genes conferring antimicrobial resistance were observed with the following frequencies: blaTEM, 40.7%; blaCMY-2, 15.2%; blaCTX-M, 11.5%; sul2, 27.2%; sul1, 14.4%; tet(A), 5.4%; tet(L), 5.4%; tet(M), 5.0%; tet(E), 3.7%; tet(C), 3.3%; tet(S), 2.5%; and tet(K), 0.8%. Various antimicrobial resistance genes were found in new carriers: blaTEM in Lactococcus garvieae, Myroides odoratimimus, Aeromonas hydrophila, Staphylococcus sciuri, Raoultella terrigena, Macrococcus caseolyticus, Acinetobacter ursingii, Sphingobacterium sp., and Oceanobacillus sp.; blaCMY-2 in Lactococcus lactis, Klebsiella oxytoca, Serratia marcescens, Acinetobacter baumannii, and Myroides phaeus; tet(L) in M. caseolyticus; sul1 in Vibrio cincinnatiensis; sul2 in Acinetobacter bereziniae, Acinetobacter johnsonii, and V. cincinnatiensis; and the class 1 integron and gene cassette aadA2 in V. cincinnatiensis. Approximately 6.6% of isolates contained class 1 integrons, and one isolate harbored class 2 integrons. Plasmid associated intI1 and androgen receptor- encoding genes were transferred into Escherichia coli J53 and E. coli DH5α by conjugation and transformation experiments, respectively. Our study highlights the importance of aerobic bacteria from pork as reservoirs for antimicrobial resistance genes and mobile genetic elements that can readily be transferred intra- and interspecies.

Surveillance of Omadacycline Activity against Clinical Isolates from a Global Collection (North America, Europe, Latin America, Asia-Western Pacific), 2010-2011

PubMed Central

Pfaller, Michael A.; Huband, Michael D.; Rhomberg, Paul R.

2017-01-01

ABSTRACT Omadacycline is a broad-spectrum aminomethylcycline in late-stage clinical development for the treatment of acute bacterial skin and skin structure infections and community-acquired pneumonia as an oral and an intravenous once-daily formulation. In this study, omadacycline and comparators were tested against 69,246 nonduplicate bacterial isolates collected prospectively during 2010 and 2011 from medical centers in Asia-Pacific (11,397 isolates), Europe (23,490 isolates), Latin America (8,038 isolates), and North America (26,321 isolates). Omadacycline was tested by broth microdilution following Clinical and Laboratory Standards Institute M07-A10 (2015) methods. A total of 99.9% of Staphylococcus aureus isolates were inhibited by ≤2 μg/ml of omadacycline (MIC50/90, 0.12/0.25 μg/ml), including 100.0% of methicillin-susceptible S. aureus isolates and 99.8% of methicillin-resistant S. aureus isolates. Omadacycline potencies were comparable for Streptococcus pneumoniae (MIC50/90, 0.06/0.06 μg/ml), viridans group streptococci (MIC50/90, 0.06/0.12 μg/ml), and beta-hemolytic streptococci (MIC50/90, 0.06/0.12 μg/ml) regardless of species and susceptibility to penicillin. Omadacycline was active against Enterobacteriaceae and was most active against Escherichia coli (MIC50/90, 0.5/2 μg/ml), Enterobacter aerogenes (MIC50/90, 2/4 μg/ml), Klebsiella oxytoca (MIC50/90, 1/4 μg/ml), and Citrobacter spp. (MIC50/90, 1/4 μg/ml). Omadacycline was active against Haemophilus influenzae (MIC50/90, 1/1 μg/ml) regardless of β-lactamase status and against Moraxella catarrhalis (MIC50/90, 0.12/0.25 μg/ml). The potent activity of omadacycline against Gram-positive and Gram-negative bacteria indicates that omadacycline merits further study in serious infections in which multidrug resistance and mixed Gram-positive and Gram-negative infections may be a concern. PMID:28223386

Prospective study of bacteremia rate after elective band ligation and sclerotherapy with cyanoacrylate for esophageal varices in patients with advanced liver disease.

PubMed

Bonilha, Danielle Queiroz; Correia, Lucianna Motta; Monaghan, Marie; Lenz, Luciano; Santos, Marcus; Libera, Ermelindo Della

2011-01-01

Band ligation (BL) is the most appropriate endoscopic treatment for acute bleeding or prophylaxis of esophageal variceal bleeding. Sclerotherapy with N-butyl-2-cyanoacrylate (CY) can be an alternative for patients with advanced liver disease. Bacteremia is an infrequent complication after BL while the bacteremia rate following treatment with CY for esophageal varices remains unknown. To evaluate and compare the incidence of transient bacteremia between cirrhotic patients submitted to diagnostic endoscopy, CY and BL for treatment of esophageal varices. A prospective study comprising the period from 2004 to 2007 was conducted at Hospital of Universidade Federal de São Paulo, UNIFESP, SP, Brazil. Cirrhotic patients with advanced liver disease (Child-Pugh B or C) were enrolled. The patients were divided into two groups according treatment: BL Group (patients undergoing band ligation, n = 20) and CY Group (patients receiving cyanoacrylate injection for esophageal variceal, n = 18). Cirrhotic patients with no esophageal varices or without indication for endoscopic treatment were recruited as control (diagnostic group n = 20). Bacteremia was evaluated by blood culture at baseline and 30 minutes after the procedure. After 137 scheduled endoscopic procedures, none of the 58 patients had fever or any sign suggestive of infection. All baseline cultures were negative. No positive cultures were observed after CY or in the control group - diagnostic endoscopy. Three (4.6 %) positive cultures were found out of the 65 sessions of band ligation (P = 0.187). Two of these samples were positive for coagulase-negative staphylococcus, which could be regarded as a contaminant. The isolated microorganism in the other case was Klebsiella oxytoca. The patient in this case presented no evidence of immunodeficiency except liver disease. There was no significant difference in bacteremia rate between these three groups. BL or CY injection for non-bleeding esophageal varices may be considered as low-risk procedures regarding bacteremia even when performed on patients with advanced liver disease.

Antibiofilm efficacy of silver nanoparticles against biofilm of extended spectrum β-lactamase isolates of Escherichia coli and Klebsiella pneumoniae

NASA Astrophysics Data System (ADS)

Ansari, Mohammad Azam; Khan, Haris M.; Khan, Aijaz A.; Cameotra, Swaranjit Singh; Pal, Ruchita

2014-10-01

The ability of bacteria to develop antibiotic resistance and colonize abiotic surfaces by forming biofilms is a major cause of medical implant-associated infections and results in prolonged hospitalization periods and patient mortality. Different approaches have been used for preventing biofilm-related infections in health care settings. Many of these methods have their own demerits that include chemical-based complications; emergent antibiotic-resistant strains, and so on. Silver nanoparticles (AgNPs) are renowned for their influential antimicrobial activity. We demonstrate the biofilm formation by extended spectrum β-lactamases-producing Escherichia coli and Klebsiella spp. by direct visualization applying tissue culture plate, tube, and Congo red agar methods. Double fluorescent staining for confocal laser scanning microscopy (CLSM) consisted of propidium iodide staining to detect bacterial cells and concanavalin A-fluorescein isothiocyanate staining to detect the exopolysaccharides matrix were used. Scanning electron microscopy observations clearly indicate that AgNPs reduced the surface coverage by E. coli and Klebsiella spp. thus prevent the biofilm formations. Double-staining technique using CLSM provides the visual evidence that AgNPs arrested the bacterial growth and prevent the exopolysaccharides formation. The AgNPs-coated surfaces effectively restricted biofilm formation of the tested bacteria. In our study, we could demonstrate the complete antibiofilm activity AgNPs at a concentration as low as 50 μg/ml. Our findings suggested that AgNPs can be exploited towards the development of potential antibacterial coatings for various biomedical and environmental applications. These formulations can be used for the treatment of drug-resistant bacterial infections caused by biofilms, at much lower nanosilver loading with higher efficiency.

Emergence of carbapenem-non-susceptible extended-spectrum beta-lactamase-producing Klebsiella pneumoniae isolates at the university hospital of Tübingen, Germany.

PubMed

Gröbner, Sabine; Linke, Dirk; Schütz, Wolfgang; Fladerer, Claudia; Madlung, Johannes; Autenrieth, Ingo B; Witte, Wolfgang; Pfeifer, Yvonne

2009-07-01

The spread of Gram-negative bacteria with plasmid-borne extended-spectrum beta-lactamases (ESBLs) has become a worldwide problem. This study analysed a total of 366 ESBL-producing Enterobacteriaceae strains isolated from non-selected patient specimens at the university hospital of Tübingen in the period January 2003 to December 2007. Although the overall ESBL rate was comparatively low (1.6 %), the percentages of ESBL-producing Enterobacter spp. and Escherichia coli increased from 0.8 and 0.5 %, respectively, in 2003 to 4.6 and 3.8 % in 2007. In particular, the emergence was observed of one carbapenem-resistant ESBL-producing E. coli isolate and five carbapenem-non-susceptible ESBL-positive Klebsiella pneumoniae isolates, in two of which carbapenem resistance development was documented in vivo under a meropenem-containing antibiotic regime. The possible underlying mechanism for this carbapenem resistance in three of the K. pneumoniae isolates was loss of the Klebsiella porin channel protein OmpK36 as shown by PCR analysis. The remaining two K. pneumoniae isolates exhibited increased expression of a tripartite AcrAB-TolC efflux pump as demonstrated by SDS-PAGE and mass spectrometry analysis of bacterial outer-membrane extracts, which, in addition to other unknown mechanisms, may contribute towards increasing the carbapenem MIC values further. Carbapenem-non-susceptible ESBL isolates may pose a new problem in the future due to possible outbreak situations and limited antibiotic treatment options. Therefore, a systematic exploration of intestinal colonization with ESBL isolates should be reconsidered, at least for haemato-oncological departments from where four of the five carbapenem-non-susceptible ESBL isolates originated.

Impact of carbapenem resistance on the outcome of patients' hospital-acquired bacteraemia caused by Klebsiella pneumoniae.

PubMed

Hussein, K; Raz-Pasteur, A; Finkelstein, R; Neuberger, A; Shachor-Meyouhas, Y; Oren, I; Kassis, I

2013-04-01

Carbapenem-resistant Enterobacteriaceae, especially Klebsiella spp., have become a major health problem recently worldwide. Since 2006 the incidence of carbapenem-resistant Klebsiella pneumoniae (CRKP) infections has increased substantially in Israel. Bloodstream infections (BSIs) caused by these strains have been associated with high rates of treatment failure and mortality. This study was designed to identify risk factors for carbapenem resistance among patients with healthcare-related (HCR) K. pneumoniae bacteraemia and predictors of mortality associated with HCR-CRKP bacteraemia compared with carbapenem-susceptible K. pneumoniae (CSKP). In this retrospective case-control study, all cases of K. pneumoniae bacteraemia during 2006-2008 were identified. Resistance patterns, underlying morbidities, risk factors for drug resistance and mortality rates were compared for patients with CRKP and CSKP bacteraemia. Two hundred and fourteen patients with CSKP bacteraemia were compared with 103 patients with CRKP bacteraemia. Severe, chronic comorbidities and prior antibiotic use were more frequent among patients with CRKP bacteraemia. On multivariate analysis prior use of macrolides and antibiotic exposure for ≥14 days remained the only independent factors associated with CRKP bacteraemia. Mortality rates of CRKP patients were significantly higher than those of CSKP patients. On multivariate analyses: bedridden status, chronic liver disease, Charlson comorbidity index ≥5, mechanical ventilation, and haemodialysis remained independently associated with mortality among patients with K. pneumoniae bacteraemia. Carbapenem resistance was not a risk factor for mortality. Previous antibiotic exposure is a risk factor for CRKP-BSI. Mortality among patients with K. pneumoniae bacteraemia is associated with serious comorbidities, but not with carbapenem resistance. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Clinical effect of biapenem on nursing and healthcare-associated pneumonia (NHCAP).

PubMed

Okimoto, Niro; Kawai, Yasuhiro; Katoh, Tadashi; Hayashi, Toshikiyo; Kurihara, Takeyuki; Miyashita, Naoyuki

2015-08-01

The clinical effect of Biapenem (BIPM) on Nursing and Healthcare-associated pneumonia (NHCAP) was evaluated. One hundred and three NHCAP patients (Group B: 52 patients, Group C: 51 patients) to whom BIPM was administered were included in this study. Clinical effect, bacteriological effect, and adverse events were examined. Results revealed efficacy in 45 of 52 patients (efficacy rate: 86.5%) of NHCAP Group B, and 43 of 51 patients (efficacy rate: 84.3%) of NHCAP Group C, 88 of 103 patients (efficacy rate: 85.4%) as a whole. As for bacteriological effect, 10 (76.9%) of 13 Pseudomonas aeruginosa strains, 9 (90.0%) of 10 Klebsiella pneumoniae strains, 7 (87.5%) of 8 methicillin-sensitive Staphlococcus aureus strains, and 7 (100%) of 7 Streptococcus pneumonia strains were eradicated. As a whole, 38 (80.9%) of 47 strains were eradicated. Adverse events included drug fever and drug eruption in one patient each, and abnormal laboratory findings, including mild hepatic dysfunction in 18 patients and mild renal dysfunction in 5 patients. Based on the above, it was concluded that BIPM shows excellent clinical effect on NHCAP with fewer adverse events. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Could Frequent Carbapenem Use Be a Risk Factor for Colistin Resistance?

PubMed

Gundogdu, Aycan; Ulu-Kilic, Aysegul; Kilic, Huseyin; Ozhan, Esra; Altun, Dilek; Cakir, Ozlem; Alp, Emine

2017-10-13

The antibiotic colistin, which had been previously abandoned, is being brought back as a last line of defense against bacterial infection. However, colistin resistance was reported shortly after its reintroduction. This study evaluated the risk factors for colonization/infections due to colistin-resistant Acinetobacter baumannii (ColR-Ab) and Klebsiella pneumoniae (ColR-Kp) strains and characterized the molecular epidemiology of these two strains. Age, previous hospitalization duration, and previous use of carbapenem and colistin were risk factors for ColR-Kp, whereas previous use of carbapenem and colistin was a risk factor for ColR-Ab. According to pulsed-field gel electrophoresis analysis, most ColR-Kp strains could be grouped into two major pulsotypes. This appears to be an indicator of cross contamination of ColR-Kp strain, since different isolates appeared to be belonging to the same clones. The existence of colistin-susceptible (ColS) and colistin-resistant (ColR) strains in the same pulsotypes might also be an indicator of the recent emergence of resistance mechanisms. The results highlight the emergence of ColR pathogens in Turkey, which is considered to be developing country, and that carbapenem use coupled with insufficient infection control measures might increase the risk of ColR outbreaks.

Extended-spectrum β-lactamases and plasmid-mediated quinolone resistance in enterobacterial clinical isolates from neonates in Tunisia.

PubMed

Charfi, Karama; Grami, Raoudha; Ben Jeddou, Abir; Messaoudi, Aziza; Mani, Yosra; Bouallegue, Olfa; Boujaafar, Noureddine; Aouni, Mahjoub; Mammeri, Hedi; Mansour, Wejdène

2017-09-01

This study was conducted to investigate extended-spectrum-β-lactamase (ESBL) producing Enterobacteriaceae isolates from the Center of Maternity and Neonatology of Monastir, Tunisia. Fourty-six strains out of 283 were found to produce ESBL: Klebsiella pneumoniae (n = 37), Escherichia coli (n = 6), Enterobacter cloacae (n = 2), and Citrobacter freundi (n = 1). Genotyping analysis, using ERIC2 and RAPD, showed that strains were clonally unrelated. PCR amplification followed by sequencing revealed that all strains produced CTX-M-15. This enzyme was co-produced with TEM and SHV determinants in 34 and 36 strains respectively. The bla CTXM-15 gene was bracked by ISEcp1 and/or IS26 in 42 out of the 46 ESBL positive strains. The quinolone resistance determinants were associated to the ESBL producing isolates: we identified the qnrB1 gene in six isolates and the aac(6')-Ib-cr gene in five isolates. This epidemiological study shows the widespread of CTX-M-15 and qnr determinants among enterobacterial isolates from neonates hospitalized at the center of Maternity and Neonatology of Monastir suggesting either mother portage or horizontal transmission. Copyright © 2017 Elsevier Ltd. All rights reserved.