Science.gov

Sample records for producing clinical isolate

  1. Integron mediated multidrug resistance in extended spectrum beta-lactamase producing clinical isolates of Klebsiella pneumoniae

    PubMed Central

    Mobarak-Qamsari, Maryam; Ashayeri-Panah, Mitra; Eftekhar, Freshteh; Feizabadi, Mohammad Mehdi

    2013-01-01

    The present study describes integron mediated multiple antibiotic resistance in extended-spectrum β-lactamase producing clinical isolates of Klebsiella pneumoniae. One hundred and four clinical isolates of K. pneumoniae from two Iranian hospitals were screened for extended-spectrum β-lactamase production and susceptibility of the extended-spectrum β-lactamase producing isolates was determined to 17 antibiotics by disc diffusion. Presence of integron classes 1, 2 and 3 was detected by PCR and integrase specific primers. Isolates harboring class 1 integron were then screened for variable regions using PCR. Fifty isolates (48%) produced extended-spectrum β-lactamases among which, 22 (44%) harbored class 1, 3 (6%) carried class 2 and none contained class 3 integons. Integron carriage was significantly associated with higher rates of multiple antibiotic resistance in extended-spectrum β-lactamase producing clinical isolates of K. pneumoniae. Integron harboring isolates were more resistant to aztreonam (51.3%), ceftazidime (42.6%), cefotaxime (43.3%), cefepime (24.6%), kanamycin (43.2%), tobramycin (30.7%), norfloxcacin (32%) and spectinomycin (25.6%) compared to the organisms without integrons. On the other hand, resistance to nitrofurantoin and streptomycin was significantly higher among the integron negative isolates. PCR amplification of class1 integron variable regions revealed 9 different sized DNA fragments and isolates with similar profiles for class 1 integron variable regions showed the same antibiotic resistance phenotypes. PMID:24516451

  2. Characterization of TEM-1 β-Lactamase-Producing Kingella kingae Clinical Isolates

    PubMed Central

    Banerjee, Anushree; Kaplan, Jeffrey B.; Soherwardy, Amenah; Nudell, Yoav; Mackenzie, Grace A.; Johnson, Shannon

    2013-01-01

    Kingella kingae is a human pathogen that causes pediatric osteoarticular infections and infective endocarditis in children and adults. The bacterium is usually susceptible to β-lactam antibiotics, although β-lactam resistance has been reported in rare isolates. This study was conducted to identify β-lactam-resistant strains and to characterize the resistance mechanism. Screening of a set of 90 K. kingae clinical isolates obtained from different geographic locations revealed high-level resistance to penicillins among 25% of the strains isolated from Minnesota and Iceland. These strains produced TEM-1 β-lactamase and were shown to contain additional ≥50-kb plasmids. Ion Torrent sequencing of extrachromosomal DNA from a β-lactamase-producing strain confirmed the plasmid location of the blaTEM gene. An identical plasmid pattern was demonstrated by multiplex PCR in all β-lactamase producers. The porin gene's fragments were analyzed to investigate the relatedness of bacterial strains. Phylogenetic analysis revealed 27 single-nucleotide polymorphisms (SNPs) in the por gene fragment, resulting in two major clusters with 11 allele types forming bacterial-strain subclusters. β-Lactamase producers were grouped together based on por genotyping. Our results suggest that the β-lactamase-producing strains likely originate from a single plasmid-bearing K. kingae isolate that traveled from Europe to the United States, or vice versa. This study highlights the prevalence of penicillin resistance among K. kingae strains in some regions and emphasizes the importance of surveillance for antibiotic resistance of the pathogen. PMID:23796935

  3. Emergence of Klebsiella pneumoniae clinical isolates producing KPC-2 carbapenemase in Cuba

    PubMed Central

    Quiñones, D; Hart, M; Espinosa, F; Garcia, S; Carmona, Y; Ghosh, S; Urushibara, N; Kawaguchiya, M; Kobayashi, N

    2014-01-01

    The emergence of Klebsiella pneumoniae producing carbapenemase (KPC) has now become a global concern. As a part of a nationwide multicentre surveillance study in Cuba, three K. pneumoniae clinical isolates resistant to carbapenems were detected for a 1-month period (September to October 2011). PCR and sequence analysis revealed that the three strains harboured blaKPC-2. They showed resistance or intermediate susceptibility to expanded-spectrum cephalosporins, other β-lactams, a β-lactam/β-lactamase inhibitor combination, and gentamicin. Two strains were susceptible only to colistin, whereas the other strain showing colistin resistance was susceptible to fluoroquinolones. These blaKPC-2-positive K. pneumoniae strains were classified into ST1271 (CC29), a novel clone harbouring blaKPC-2, and were revealed to be genetically identical by PCR-based DNA fingerprinting. The three patients infected with the KPC-producing K. pneumoniae had common risk factors, and had no overseas travel experience outside Cuba, suggesting local acquisition of the resistant pathogen. This is the first report of a KPC-producing K. pneumoniae in Cuba. Although detection of KPC in Enterobacteriaceae is still rare in Cuba, our finding indicated that KPC-producing bacteria are a global concern and highlighted the need to identify these microorganisms in clinical laboratories. PMID:25356357

  4. First report of IMI-1-producing colistin-resistant Enterobacter clinical isolate in Ireland, March 2013.

    PubMed

    Boo, T W; O'Connell, N; Power, L; O'Connor, M; King, J; McGrath, E; Hill, R; Hopkins, K L; Woodford, N

    2013-08-01

    We report the first case in Ireland of an IMI-1 carbapenemase-producing Enterobacter asburiae, which was resistant to both colistin and fosfomycin. The circumstances under which this isolate was acquired were unclear. Several reports of IMI-producing Enterobacter spp. have emerged in recent years, and colistin resistance in Enterobacteriaceae is also increasingly reported. Laboratories should be aware of the unusual antibiograms of IMI-producing isolates.

  5. Characteristics of KPC-2-producing Klebsiella pneumoniae (ST258) clinical isolates from outbreaks in 2 Mexican medical centers.

    PubMed

    Garza-Ramos, Ulises; Barrios, Humberto; Reyna-Flores, Fernando; Sánchez-Pérez, Alejandro; Tamayo-Legorreta, Elsa; Ibarra-Pacheco, Alvaro; Salazar-Salinas, Juana; Núñez-Ceballos, Ricardo; Silva-Sanchez, Jesus

    2014-08-01

    The KPC-producing Klebsiella pneumoniae sequence type 258 (ST258) is an important pathogen widely spread in nosocomial infections. In this study, we identified the KPC-2-producing K. pneumoniae clinical isolates of 2 unrelated outbreaks that corresponded to pandemic strain ST258. The isolates showed high resistance to cephalosporins, carbapenems, quinolones, and colistin. The KPC-2-producing K. pneumoniae isolates were compared to the previously studied KPC-3-producing K. pneumoniae isolates from an outbreak in Mexico; they showed an unrelated pulsed-field gel electrophoresis fingerprinting pattern and a different plasmid profile. The KPC-2 carbapenemase gene was identified in two 230- and 270-kb non-conjugative plasmids; however, 1 isolate transferred the KPC-2 gene onto an 80-kb plasmid. These findings endorse the need of carrying out a continuous molecular epidemiological surveillance of carbapenem-resistant isolates in hospitals in Mexico.

  6. Emerging Perils of Extended Spectrum β-Lactamase Producing Enterobacteriaceae Clinical Isolates in a Teaching Hospital of Nepal

    PubMed Central

    Maharjan, Pooja; Joshi, Govardhan; Khanal, Puspa Raj

    2016-01-01

    Introduction. Infections due to extended spectrum β-lactamase producing Enterobacteriaceae are on the rise. They pose serious public health problems due to their resistance to large number of antibiotics. However, little is known about the genotypes of ESBL from Nepal. Therefore, the study presents results of phenotypic and molecular characterization of ESBL producing Escherichia coli and Klebsiella spp. isolated from various clinical specimens in a tertiary care teaching hospital of Nepal. Methods. A total of 172 Enterobacteriaceae clinical isolates recovered from various clinical specimens were analyzed for their antibiotic susceptibility test. Detection of ESBLs was carried out using combination disk test and multiplex PCR for their genotypes (CTX-M, SHV, and TEM). Results. Out of 172 clinical isolates, 70 (40.6%) of them were found ESBL producers. The major source of ESBL producers was urinary tract samples and the highest ESBL production was observed in Escherichia coli (46.5%). Among ESBL genotypes, CTX-M (91.4%) was most predominant, followed by TEM (65.7%) and SHV (11.4%) in both of the isolates. Conclusions. High level of drug resistance and ESBL production was observed among the clinical isolates. There is a need for longitudinal and nationwide surveillance for drug resistance in clinical isolates and antimicrobial stewardship is necessary to guide the appropriate and judicious antibiotic use. PMID:28119921

  7. Yersiniabactin and other siderophores produced by clinical isolates of Enterobacter spp. and Citrobacter spp.

    PubMed

    Mokracka, Joanna; Koczura, Ryszard; Kaznowski, Adam

    2004-01-15

    We analyzed the ability of extraintestinal strains of Enterobacter spp. and Citrobacter spp. to employ different siderophore-mediated strategies of iron acquisition. All strains produced iron-chelating compounds. Cross-feeding assays indicated that most isolates of both Enterobacter spp. and Citrobacter spp. excreted catecholate siderophore enterobactin, less produced aerobactin, and single strains excreted hydroxamates different from aerobactin. Besides, we analyzed if the strains had the ability to produce the siderophore yersiniabactin coded by the Yersinia high-pathogenicity island (HPI). The presence of HPI genes was observed in single isolates of three species: E. cloaceae, E. aerogenes and C. koseri. A detailed polymerase chain reaction analysis revealed differences in the genetic organization of the HPIs; however, in a cross-feeding test we proved that yersiniabactin was produced and the island was functional.

  8. Antibacterial synergy of curcumin with antibiotics against biofilm producing clinical bacterial isolates

    PubMed Central

    Kali, Arunava; Bhuvaneshwar, Devaraj; Charles, Pravin M. V.; Seetha, Kunigal Srinivasaiah

    2016-01-01

    Introduction: The role of natural bioactive substances in treating infections has been rediscovered as bacterial resistance become common to most of the antibiotics. Curcumin is a bioactive substance from turmeric. Owing to antimicrobial properties, its prospect as an antibacterial agent is currently under focus. Materials and Methods: We have evaluated the in vitro synergy of curcumin with antibiotics against sixty biofilm producing bacterial isolates. Congo red agar method was used to identify the biofilm producing isolates. Curcumin minimum inhibitory concentration (MIC) was determined by agar dilution method. Its antibiotic synergy was identified by the increase in disc diffusion zone size on Mueller-Hinton agar with 32 mg/L curcumin. Results: The mean MICs of curcumin against Gram-positive and Gram-negative isolates were 126.9 mg/L and 117.4 mg/L, respectively. Maximum synergy was observed with ciprofloxacin among Gram-positive and amikacin, gentamicin, and cefepime among Gram-negative isolates. Conclusions: Curcumin per se as well as in combination with other antibiotics has a demonstrable antibacterial action against biofilm producing bacterial isolates. It may have a beneficial role in supplementing antibiotic therapy. PMID:27330262

  9. Reduced Susceptibility to Cefepime in Clinical Isolates of Enterobacteriaceae Producing OXA-1 Beta-Lactamase.

    PubMed

    Torres, Eva; López-Cerero, Lorena; Rodríguez-Martínez, José Manuel; Pascual, Álvaro

    2016-03-01

    An increase of Enterobacteriaceae isolates with reduced susceptibility to cefepime (FEP) and amoxicillin/clavulanate (AMC) has been observed in our area. The aim of this study was to characterize this antibiotic resistance phenotype and its molecular epidemiology. A total of 33 Enterobacteriaceae strains were studied. blaOXA-1 genes and their genetic environment were analyzed by polymerase chain reaction (PCR) and sequencing. Plasmids were transferred by conjugation and/or transformation and classified using PCR-based inc/rep typing and IncF subtyping. Escherichia coli isolates were typed by phylogroup, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. Outer membrane proteins were studied by sodium dodecylsulfate-polyacrylamide gel electrophoresis and expression of blaOXA-1 genes by reverse transcription-PCR. FEP minimum inhibitory concentration yielded values of 1-16 mg/L. Twenty-nine (87.9%) isolates produced OXA-1, of which 24 (82.7%) were located in class 1 integron, and 9 (27.3%) produced TEM-1. Among the 24 E. coli OXA-1-producers, PFGE revealed two main clusters: one belonged to C-ST88 and the other to B23-ST131. Thirteen plasmids containing blaOXA-1 were transferred, nine belonged to IncF replicon (4 F2:A1:B-, 2 F1:A1:B1, 1 F1:A2:B-, 1 F18:A2:B1, 1 F5:A-:B1) and four were nontypeable. In conclusion, reduced susceptibility to FEP was mostly due to OXA-1 beta-lactamase. In E. coli, this increase is mainly due to the dissemination of two clones, which have captured different IncF plasmids. Among non-E. coli strains, five isolates produced OXA-1 and one isolate produced only TEM-1.

  10. Molecular characterization of integrons in clinical isolates of betalactamase-producing Escherichia coli and Klebsiella pneumoniae in Iran.

    PubMed

    Zeighami, Habib; Haghi, Fakhri; Hajiahmadi, Fahimeh

    2015-06-01

    Integrons are considered to play a significant role in the evolution and spread of antibiotic resistance genes. A total of 349 clinical isolates of Escherichia coli and Klebsiella pneumoniae were investigated for molecular characterization of integrons and betalactamases. Antimicrobial susceptibility testing was also performed as the Clinical and Laboratory Standards Institute (CLSI) guidelines. The frequency of extended spectrum betalactamases (ESBL) or metallo-betalactamases (MBL)-producing isolates, patient demographics, and the susceptibility to various antimicrobial agents were described. BlaCTX-M was the most frequently detected betalactamase in all isolates. Moreover, MBL producing K. pneumoniae carried blaIMP and blaVIM at 100 and 41·6%, respectively but no MBL-positive E. coli was detected. Class 1 integrons were more frequent among E. coli and K. pneumoniae isolates in comparison with class 2 integrons and the frequency of intI2 in K. pneumoniae was significantly higher than E. coli isolates. Five different resistance gene arrays were identified among class 1 integrons. Dihydrofolate reductase (dfrA) and aminoglycoside adenyltransferase (aad) gene cassettes were found to be predominant in the class 1 integrons. These results indicate that class 1 integrons are widespread among ESBL-producing isolates of K. pneumoniae and E. coli and appropriate surveillance and control measures are essential to prevent further dissemination of these elements among Enterobacteriaceae in our country.

  11. Antimicrobial effects of Ferula gummosa Boiss gum against extended-spectrum β-lactamase producing Acinetobacter clinical isolates

    PubMed Central

    Afshar, Fatemeh Farid; Saffarian, Parvaneh; Hosseini, Hamideh Mahmoodzadeh; Sattarian, Fereshteh; Amin, Mohsen; Fooladi, Abbas Ali Imani

    2016-01-01

    Background and Objectives: Acinetobacter spp. are important causes of nosocomial infections. They possess various antibiotic resistance mechanisms including extended spectrum beta lactamases (ESBLs). The aim of this study was to determine antibiotic resistance profile of Acinetobacter clinical isolates especially among ESBL-producing strains and to investigate the antimicrobial effects of oleo-gum-resin extract and essential oil of Ferula gummosa Boiss. Materials and Methods: 120 Acinetobacter strains were isolated from various clinical samples of hospitalized patients in Baqiyatallah hospital, Tehran during 2011–2012. Antibiotic susceptibility test was performed on the isolates using disk diffusion method. To detect and confirm the ESBL-positive isolates, phenotypic and genotypic tests were performed. Three types of F. gummosa oleo-gum-resin extracts and essential oils were prepared and the bioactive components of F. gummosa Boiss extracts were determined by GC-Mass chromatography. F. gummosa antimicrobial activity was evaluated against standard strain of Acinetobacter baumannii (ATCC19606) as well as Acinetobacter clinical isolates using well and disk diffusion methods. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by broth microdilution method. Results: 46 isolates were resistant to all tested antibiotics. All clinical isolates were resistant to cefotaxime. 12.94% of the isolates were phenotypically ESBL-producing among which 94.2% carried ESBL genes ( bla PER-1 , bla OXA-4 and bla CTX-M ) detected by PCR. Oleo-gum-resin of F. gummosa had significant antibacterial activity and alcoholic essential oil had higher inhibitory effect on Acinetobacter strains (MIC of 18.75 mg/ml). Conclusion: Ferula gummosa extract contained components with well-known antimicrobial effects. PMID:28210466

  12. Isolation of VIM-2-Producing Pseudomonas monteilii Clinical Strains Disseminated in a Tertiary Hospital in Northern Spain

    PubMed Central

    Guzmán-Gómez, Laura P.; Fernández-Martínez, Marta; Román, Elena; Rodríguez, Cristina; Marco, Francesc; Vila, Jordi; Martínez-Martínez, Luis

    2014-01-01

    We describe here the occurrence of blaVIM-2 in 10 carbapenem-resistant Pseudomonas monteilii strains isolated from different clinical samples from patients at the University Hospital Marqués de Valdecilla in northern Spain. All the blaVIM-2-harboring P. monteilii isolates possessed a class 1 integron, with the cassette array [intI1_blaVIM-2_aac(6′)-Ib_qacEΔ1_sul1]. Our results show the emergence of VIM-2-producing multidrug-resistant species other than Pseudomonas aeruginosa or Pseudomonas putida in a Spanish hospital. P. monteilii, although sporadically isolated, should also be considered an important metallo-β-lactamase (MBL) reservoir. PMID:25421471

  13. Outbreak Caused by blaOXA-72-Producing Acinetobacter baumannii ST417 Detected in Clinical and Environmental Isolates.

    PubMed

    Tamayo-Legorreta, Elsa; Turrubiartes-Martínez, Edgar; Garza-Ramos, Ulises; Niño-Moreno, Perla; Barrios, Humberto; Sánchez-Pérez, Alejandro; Reyna-Flores, Fernando; Tovar-Oviedo, Juana; Magaña-Aquino, Martin; Cevallos, Miguel Angel; Silva-Sanchez, Jesus

    2016-03-01

    We characterized an outbreak of imipenem-resistant Acinetobacter baumannii with clinical and environmental isolates from a tertiary care hospital in San Luis Potosi, Mexico. During a 4-month period, a total of 32 nonrepetitive imipenem-resistant clinical isolates of A. baumannii were collected. All isolates were susceptible to colistin and tigecycline and resistant to cefepime, ceftazidime, ceftriaxone, imipenem, and meropenem. Genotyping by pulsed-field gel electrophoresis showed a major clone (A). Multilocus sequence type (MLST) analysis was performed, revealing sequence type (ST) 417 (ST417) and 208 (ST208). The blaIMP-, blaVIM-, blaGIM-, blaSIM-, blaNDM-type, and blaOXA-type (blaOXA-23-like, blaOXA-24-like, blaOXA-51-like, and blaOXA-58-like) genes were screened and showed that the blaOXA-51-like and blaOXA-24-like genes were present in all isolates. Sequencing and southern hybridization were performed, confirming the presence of the blaOXA-72 gene and its plasmid-borne nature. In addition, the blaOXA-72-XerC/XerD-like association was identified. These findings indicate that a clonal spread of blaOXA-72-producing A. baumannii ST417 had occurred throughout the hospital. The ST417 corresponded with a previous ST described in the United States.

  14. Antibiofilm Peptides Increase the Susceptibility of Carbapenemase-Producing Klebsiella pneumoniae Clinical Isolates to β-Lactam Antibiotics

    PubMed Central

    Ribeiro, Suzana Meira; de la Fuente-Núñez, César; Baquir, Beverlie; Faria-Junior, Célio

    2015-01-01

    Multidrug-resistant carbapenemase-producing Klebsiella pneumoniae (KpC) strains are becoming a common cause of infections in health care centers. Furthermore, Klebsiella can develop multicellular biofilms, which lead to elevated adaptive antibiotic resistance. Here, we describe the antimicrobial and antibiofilm activities of synthetic peptides DJK-5, DJK-6, and 1018 against five KpC isolates. Using static microplate assays, it was observed that the concentration required to prevent biofilm formation by these clinical isolates was below the MIC for planktonic cells. More-sophisticated flow cell experiments confirmed the antibiofilm activity of the peptides against 2-day-old biofilms of different KpC isolates, and in some cases, the peptides induced significant biofilm cell death. Clinically relevant combinations of DJK-6 and β-lactam antibiotics, including the carbapenem meropenem, also prevented planktonic growth and biofilm formation of KpC strain1825971. Interestingly, peptide DJK-6 was able to enhance, at least 16-fold, the ability of meropenem to eradicate preformed biofilms formed by this strain. Using peptide DJK-6 to potentiate the activity of β-lactams, including meropenem, represents a promising strategy to treat infections caused by KpC isolates. PMID:25896694

  15. Draft Genome Sequence of a Hypermucoviscous Extended-Spectrum-β-Lactamase-Producing Klebsiella quasipneumoniae subsp. similipneumoniae Clinical Isolate

    PubMed Central

    Silva-Sánchez, J.; Catalán-Nájera, J.; Barrios, H.; Rodríguez-Medina, N.; Garza-González, E.; Cevallos, M. A.; Lozano, L.

    2016-01-01

    A clinical isolate of extended-spectrum-β-lactamase-producing Klebsiella quasipneumoniae subsp. similipneumoniae 06-219 with hypermucoviscosity phenotypes obtained from a urine culture of an adult patient was used for whole-genome sequencing. Here, we report the draft genome sequences of this strain, consisting of 53 contigs with an ~5.6-Mb genome size and an average G+C content of 57.36%. The annotation revealed 6,622 coding DNA sequences and 77 tRNA genes. PMID:27389261

  16. In vivo development of carbapenem resistance in clinical isolates of Enterobacter aerogenes producing multiple beta-lactamases.

    PubMed

    Chen, Ya-Gang; Zhang, Ying; Yu, Yun-Song; Qu, Ting-Ting; Wei, Ze-Qing; Shen, Ping; Li, Lan-Juan

    2008-10-01

    Four clinical strains of extended-spectrum beta-lactamase- and AmpC-producing Enterobacter aerogenes were isolated successively from a liver transplantation patient. Isolates C(1) and C(2) were isolated prior to carbapenem therapy, whilst isolates C(3) and C(4) were recovered after 40 days of carbapenem therapy. The homology of these strains was analysed by pulsed-field gel electrophoresis (PFGE). beta-Lactamases were analysed by isoelectric focusing, polymerase chain reaction (PCR) and sequencing. Outer membrane proteins were analysed by PCR, sequencing, sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blot. Disruption of OmpE36 in C(1) in vitro was also performed by homologous gene recombination. The isolates demonstrated an indistinguishable PFGE pattern. Molecular characterisation revealed that, in addition to the pre-existing multiple beta-lactamases (DHA-1, TEM-1, SHV-5, CTX-M-3 and CTX-M-14) found in C(1) and C(2), isolates C(3) and C(4) failed to express OmpE36 owing to insertional inactivation by an IS903-like insertion sequence. Other resistance mechanisms, such as production of carbapenem-hydrolysing enzymes or expression of chromosomal efflux, were apparently not involved. Completely replacing OmpE36 by the kanamycin resistance gene (kan) resulted in a significant increase in carbapenem minimum inhibitory concentrations of an ompE36 mutant. Thus, C(3) and C(4) were apparently derived from the previously imipenem-susceptible isolates C(1) and C(2). Following carbapenem exposure, depletion of OmpE36 expression resulted in the collateral effect of carbapenem resistance.

  17. Emergence of an NDM-5-producing clinical Escherichia coli isolate in Egypt.

    PubMed

    Soliman, Ahmed M; Khalifa, Hazim O; Ahmed, Ashraf M; Shimamoto, Toshi; Shimamoto, Tadashi

    2016-07-01

    The first occurrence of New Delhi metallo-β-lactamase 5 (NDM-5), carried on an IncI1-Iγ-type plasmid of >93kb in a multidrug-resistant Escherichia coli strain in Kafr El-Sheikh, Egypt, is reported. The strain was isolated from a wound pus swab from a patient diagnosed with a fracture of the right femur. This E. coli strain was found to belong to sequence type (ST) 5018 and also to carry other resistance genes, including blaCTX-M-15, blaCMY-42, blaOXA-1, and aac(6')-Ib-cr.

  18. Tigecycline-Amikacin Combination Effectively Suppresses the Selection of Resistance in Clinical Isolates of KPC-Producing Klebsiella pneumoniae

    PubMed Central

    Ni, Wentao; Wei, Chuanqi; Zhou, Chufei; Zhao, Jin; Liang, Beibei; Cui, Junchang; Wang, Rui; Liu, Youning

    2016-01-01

    By far, only tigecycline, colistin, and some aminoglycosides still show favorable in vitro activities against carbapenem-resistant Enterobacteriaceae. However, rapid emergence of resistance often occurs during long-term treatment in clinic, challenging these last resort antimicrobials. In this study, we measured mutant prevention concentration (MPC) and mutant selection window (MSW) of tigecycline, colistin and amikacin alone and in combination for clinical isolates of KPC-producing K. pneumoniae, and characterized the resistant mutants recovered. The MPC90 of 30 tested isolates for tigecycline, colistin, and amikacin were 16, >128, and 128 mg/L, respectively. The average MSW of tigecycline-amikacin, tigecycline-colistin, and amikacin-colistin combinations for four representative strains were 11.99, 200.13, and 372.38, respectively. A strong correlation was found between the MSWcombination and the product of MSW of each single drug. Combinations of 1 minimal inhibitory concentration (MIC) multiple tigecycline and 1 MIC multiple amikacin could result in 1000- to 10000-fold reduction in mutational frequency relative to their individual mutational frequencies, and combinations of 1 MIC multiple amikacin and 1.5–2 MIC multiple tigecycline could successfully restrict the recovery of resistant mutants on agar plates. However, 2 MIC multiple colistin in combination with 2 MIC multiple tigecycline or amikacin merely resulted in approximately 10-fold decrease in the mutational frequency. In conclusion, this study showed tigecycline-amikacin combination could effectively suppress the selection of resistance at low concentrations compared with the colistin-tigecycline and colistin-amikacin combinations, suggesting that this combination may be useful in clinical therapy. PMID:27594855

  19. Tigecycline-Amikacin Combination Effectively Suppresses the Selection of Resistance in Clinical Isolates of KPC-Producing Klebsiella pneumoniae.

    PubMed

    Ni, Wentao; Wei, Chuanqi; Zhou, Chufei; Zhao, Jin; Liang, Beibei; Cui, Junchang; Wang, Rui; Liu, Youning

    2016-01-01

    By far, only tigecycline, colistin, and some aminoglycosides still show favorable in vitro activities against carbapenem-resistant Enterobacteriaceae. However, rapid emergence of resistance often occurs during long-term treatment in clinic, challenging these last resort antimicrobials. In this study, we measured mutant prevention concentration (MPC) and mutant selection window (MSW) of tigecycline, colistin and amikacin alone and in combination for clinical isolates of KPC-producing K. pneumoniae, and characterized the resistant mutants recovered. The MPC90 of 30 tested isolates for tigecycline, colistin, and amikacin were 16, >128, and 128 mg/L, respectively. The average MSW of tigecycline-amikacin, tigecycline-colistin, and amikacin-colistin combinations for four representative strains were 11.99, 200.13, and 372.38, respectively. A strong correlation was found between the MSW combination and the product of MSW of each single drug. Combinations of 1 minimal inhibitory concentration (MIC) multiple tigecycline and 1 MIC multiple amikacin could result in 1000- to 10000-fold reduction in mutational frequency relative to their individual mutational frequencies, and combinations of 1 MIC multiple amikacin and 1.5-2 MIC multiple tigecycline could successfully restrict the recovery of resistant mutants on agar plates. However, 2 MIC multiple colistin in combination with 2 MIC multiple tigecycline or amikacin merely resulted in approximately 10-fold decrease in the mutational frequency. In conclusion, this study showed tigecycline-amikacin combination could effectively suppress the selection of resistance at low concentrations compared with the colistin-tigecycline and colistin-amikacin combinations, suggesting that this combination may be useful in clinical therapy.

  20. Occurrence of the Plasmid-Mediated Fluoroquinolone Resistance qepA1 Gene in Two Clonal Clinical Isolates of CTX-M-15-Producing Escherichia coli from Algeria.

    PubMed

    Yanat, Betitera; Dali Yahia, Radia; Yazi, Leila; Machuca, Jesús; Díaz-De-Alba, Paula; Touati, Abdelaziz; Pascual, Álvaro; Rodríguez-Martínez, José-Manuel

    2016-10-13

    QepA is a plasmid-mediated quinolone resistance determinant of low prevalence described worldwide, mainly in Enterobacteriaceae. This study describes, for the first time in Algeria, two clonally related, QepA-producing Escherichia coli clinical isolates positive for CTX-M-15. The clonal spread of these multidrug-resistant isolates is a major public health concern.

  1. Evaluate the frequency distribution of nonadhesive virulence factors in carbapenemase-producing Acinetobacter baumannii isolated from clinical samples in Kermanshah

    PubMed Central

    Mohajeri, Parviz; Sharbati, Saba; Farahani, Abbas; Rezaei, Zhaleh

    2016-01-01

    Background: Acinetobacter baumannii which is a Gram-negative bacterium can cause several different infections. The appearance of carbapenemase-producing A. baumannii in recent years has made the treatment process more difficult. The identification of virulence factors (VFs), such as nonadhesives in A. baumannii, helps to fight against related infections. Materials and Methods: A total of 104 samples from teaching hospitals in Kermanshah, Iran, were collected during a 24 months period (2011-2013). Sample identification was first carried out by biochemical tests, and then their susceptibility to carbapenems was determined using the Kirby–Bauer method. For confirmation of carbapenemase-producing A. baumannii, polymerase chain reaction (PCR) was done for carbapenemase-encoding genes. In addition, the frequency of nonadhesive VFs in carbapenemase-producing isolates was determined by PCR. Results: There were 50 isolates that were identified as carbapenemase-producing A. baumannii. The PCR results showed; 40 isolates (80%) for traT, 17 isolates (34%) for cvaC, and 8 isolates (16%) for iutA, and these encode serum resistance, colicin V and aerobactin, respectively. No significant correlation was observed between these three genes. Conclusions: The mechanism of A. baumannii virulence has always been in question. The role of VFs has also been recognized in other Gram-negative bacteria. According to the prevalence of traT, cvaC and iutA, as nonadhesive VFs, we can suggest that they could be the main mechanism of carbapenemase-producing A. baumannii pathogenesis. PMID:27003971

  2. Modified Hodge test using Mueller-Hinton agar supplemented with cloxacillin improves screening for carbapenemase-producing clinical isolates of Enterobacteriaceae.

    PubMed

    Takayama, Yoko; Adachi, Yuzuru; Nihonyanagi, Shin; Okamoto, Ryoichi

    2015-07-01

    Increasing numbers of clinical isolates of Enterobacteriaceae that produce carbapenemase are now being detected, with the most common carbapenemase found among Enterobacteriaceae in Japan being IMP-1-type metallo-β-lactamase. Clinical isolates of Enterobacteriaceae harbouring carbapenemases may be resistant to carbapenem antimicrobial agents, despite apparent in vitro susceptibility when tested according to Clinical and Laboratory Standards Institute criteria. We evaluated the prevalence of carbapenemase producers among isolates of Enterobacteriaceae at our hospital and assessed the performance of the modified Hodge test (MHT) for correctly identifying the phenotype. We studied 47 clinical isolates obtained between 2006 and 2010 for which the MIC of imipenem was 2 or 4 μg imipenem ml- 1. Antibacterial susceptibility testing was done for cephalosporins and carbapenems, the MHT was performed with meropenem and detection of the genes encoding IMP-1, VIM-2, KPC-2 and NDM-1-type metallo-β-lactamases was performed by PCR. Twelve isolates showed a positive result in the MHT with meropenem and were classified as carbapenemase producers. Of these 12 isolates, seven carried the gene for IMP-1 type, but not for VIM-2, KPC-2 or NDM-1 types. None of the carbapenemase genes tested were detected in the other five isolates. All five isolates were Enterobacter cloacae showing high resistance to ceftazidime and aztreonam. False-positive results were inhibited when Mueller-Hinton agar supplemented with 200 mg cloxacillin ml- 1 was used for the MHT. Five of 12 MHT-positive isolates were shown to have no carbapenemase genes and these isolates were high AmpC producers. Adding cloxacillin when performing the MHT prevented such false-positive results. The MHT with cloxacillin can overcome most problems related to detection of carbapenemases.

  3. Plasmid Profile Analysis and bla VIM Gene Detection of Metalo β-lactamase (MBL) Producing Pseudomonas aeruginosa Isolates from Clinical Samples

    PubMed Central

    M, Jeya

    2014-01-01

    Introduction:Pseudomonas aeruginosa is a frequent colonizer of hospitalized patients. They are responsible for serious infections such as meningitis, urological infections, septicemia and pneumonia. Carbapenem resistance of Pseudomonas aeruginosa is currently increasingly reported which is often mediated by production of metallo-β-lactamase (MBL). Multidrug resistant Pseudomonas aeruginosa isolates may involve reduced cell wall permeability, production of chromosomal and plasmid mediated β lactamases, aminoglycosides modifying enzymes and an active multidrug efflux mechanism. Objective: This study is aimed to detect the presence and the nature of plasmids among metallo-β-lactamase producing Pseudomonas aeruginosa isolates. Also to detect the presence of bla VIM gene from these isolates. Materials and Methods: Clinical isolates of Pseudomonas aeruginosa showing the metalo-β-lactamase enzyme (MBL) production were isolated. The MBL production was confirmed by three different methods. From the MBL producing isolates plasmid extraction was done by alkaline lysis method. Plasmid positive isolates were subjected for blaVIM gene detection by PCR method. Results: Two thousand seventy six clinical samples yielded 316 (15.22%) Pseudomonas aeruginosa isolates, out of which 141 (44.62%) were multidrug resistant. Among them 25 (17.73%) were metallo-β-lactamase enzyme producers. Plasmids were extracted from 18 out of 25 isolates tested. Five out of 18 isolates were positive for the blaVIM gene detection by the PCR amplification. Conclusion: The MBL producers were susceptible to polymyxin /colistin with MIC ranging from 0.5 – 2μg/ml. Molecular detection of specific genes bla VIM were positive among the carbapenem resistant isolates. PMID:25120980

  4. Clinical isolates of Salmonella enterica serovar Agona producing NDM-1 metallo-β-lactamase: first report from Pakistan.

    PubMed

    Irfan, Seema; Khan, Erum; Jabeen, Kauser; Bhawan, Pushpa; Hopkins, Katie L; Day, Martin; Nasir, Amna; Meunier, Daniele; Woodford, Neil

    2015-01-01

    We report two cases of infantile diarrhea due to multidrug-resistant, NDM-1 metallo-β-lactamase-producing Salmonella enterica serovar Agona from Pakistan. This study alerts toward possible risk of NDM-1 transmission to enteric fever pathogens and encourages microbiologists to consider active screening of carbapenem resistance in nontyphoidal Salmonella isolates.

  5. Whole-Genome Sequence of Serratia liquefaciens HUMV-21, a Cytotoxic, Quorum-Sensing, and Biofilm-Producing Clinical Isolate

    PubMed Central

    Lázaro-Díez, María; Acosta, Felix; Remuzgo-Martínez, Sara; Ocampo-Sosa, Alain; Ocejo-Vinyals, Javier Gonzalo; Bravo, Jimena; El Aamri, Fátima; Escuela, Oliver; Martínez-Martínez, Luis

    2015-01-01

    A clinical isolate of Serratia liquefaciens (strain HUMV-21) was obtained from a skin ulcer of an adult patient. We report here its complete genome assembly using PacBio single-molecule real-time (SMRT) sequencing, which resulted in a single circular chromosome with 5.3 Mb. About 5,844 protein-coding genes are predicted from this assembly. PMID:26021922

  6. First report of an OXA-23 carbapenemase-producing Acinetobacter baumannii clinical isolate related to Tn2006 in Spain.

    PubMed

    Espinal, P; Macià, M D; Roca, I; Gato, E; Ruíz, E; Fernández-Cuenca, F; Oliver, A; Rodríguez-Baño, J; Bou, G; Tomás, M; Vila, J

    2013-01-01

    A carbapenem-resistant Acinetobacter baumannii clinical isolate belonging to European clone II and sequence type 2 was recovered from a patient in the Son Espases hospital in Mallorca, Spain. Genetic analysis showed the presence of the bla(OXA-23) gene in association with the widely disseminated transposon Tn2006. This is the first reported identification of A. baumannii carrying bla(OXA-23) in Spain.

  7. Putative connection between zoonotic multiresistant extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in dog feces from a veterinary campus and clinical isolates from dogs

    PubMed Central

    Schaufler, Katharina; Bethe, Astrid; Lübke-Becker, Antina; Ewers, Christa; Kohn, Barbara; Wieler, Lothar H.; Guenther, Sebastian

    2015-01-01

    Introduction To contribute to the understanding of multiresistant bacteria, a ‘One Health’ approach in estimating the rate of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and getting insights into the transmission from clinical settings to the surrounding environment was employed by collecting fecal samples of dogs in a public area. Isolates were compared to those from samples of diseased dogs from a nearby small-animal clinic. Materials and methods One hundred fecal samples of dogs were collected on a single day in the public area of a veterinary faculty with a small-animal clinic and adjacent residential neighborhoods. All identified ESBL-producing strains were isolated by selective plating, genotypically analyzed by DNA microarray, polymerase chain reaction, sequence analysis, and pulsed-field gel electrophoresis and compared to 11 clinical ESBL/AmpC-producing E. coli isolated from diseased dogs treated in the small-animal clinic 2 months before and 2 months following the environmental sampling collection. Results and discussion Fourteen percent (14/100) of the extra-clinical samples harbored phenotypic ESBL/putative AmpC-producing E. coli with additional resistances against other antimicrobials. One ESBL-strain displayed an identical macrorestriction pattern to one clinical, another one to three clinical clonal ESBL-producing strains. The genotypic ESBL-determinants (bla CTX-M-1 and bla CTX-M-15) and detection rates (10%) in dog feces collected outside of the small-animal clinic are comparable to the rates and ESBL-types in the healthy human population in Germany and to clinical and non-clinical samples of humans and companion animals in Europe. The occurrence of identical strains detected both outside and inside the clinical setting suggests a connection between the small-animal clinic and the surrounding environment. In conclusion, dog feces collected in proximity to veterinary facilities should be considered as a non-point infection

  8. Inhibitor-resistant TEM- and OXA-1-producing Escherichia coli isolates resistant to amoxicillin-clavulanate are more clonal and possess lower virulence gene content than susceptible clinical isolates.

    PubMed

    Oteo, Jesús; González-López, Juan José; Ortega, Adriana; Quintero-Zárate, J Natalia; Bou, Germán; Cercenado, Emilia; Conejo, María Carmen; Martínez-Martínez, Luis; Navarro, Ferran; Oliver, Antonio; Bartolomé, Rosa M; Campos, José

    2014-07-01

    In a previous prospective multicenter study in Spain, we found that OXA-1 and inhibitor-resistant TEM (IRT) β-lactamases constitute the most common plasmid-borne mechanisms of genuine amoxicillin-clavulanate (AMC) resistance in Escherichia coli. In the present study, we investigated the population structure and virulence traits of clinical AMC-resistant E. coli strains expressing OXA-1 or IRT and compared these traits to those in a control group of clinical AMC-susceptible E. coli isolates. All OXA-1-producing (n = 67) and IRT-producing (n = 45) isolates were matched by geographical and temporal origin to the AMC-susceptible control set (n = 56). We performed multilocus sequence typing and phylogenetic group characterization for each isolate and then studied the isolates for the presence of 49 virulence factors (VFs) by PCR and sequencing. The most prevalent clone detected was distinct for each group: group C isolates of sequence type (ST) 88 (C/ST88) were the most common in OXA-1 producers, B2/ST131 isolates were the most common in IRT producers, and B2/ST73 isolates were the most common in AMC-susceptible isolates. The median numbers of isolates per ST were 3.72 in OXA-1 producers, 2.04 in IRT producers, and 1.69 in AMC-susceptible isolates; the proportions of STs represented by one unique isolate in each group were 19.4%, 31.1%, and 48.2%, respectively. The sum of all VFs detected, calculated as a virulence score, was significantly higher in AMC-susceptible isolates than OXA-1 and IRT producers (means, 12.5 versus 8.3 and 8.2, respectively). Our findings suggest that IRT- and OXA-1-producing E. coli isolates resistant to AMC have a different and less diverse population structure than AMC-susceptible clinical E. coli isolates. The AMC-susceptible population also contains more VFs than AMC-resistant isolates.

  9. Inhibitor-Resistant TEM- and OXA-1-Producing Escherichia coli Isolates Resistant to Amoxicillin-Clavulanate Are More Clonal and Possess Lower Virulence Gene Content than Susceptible Clinical Isolates

    PubMed Central

    González-López, Juan José; Ortega, Adriana; Quintero-Zárate, J. Natalia; Bou, Germán; Cercenado, Emilia; Conejo, María Carmen; Martínez-Martínez, Luis; Navarro, Ferran; Oliver, Antonio; Bartolomé, Rosa M.; Campos, José

    2014-01-01

    In a previous prospective multicenter study in Spain, we found that OXA-1 and inhibitor-resistant TEM (IRT) β-lactamases constitute the most common plasmid-borne mechanisms of genuine amoxicillin-clavulanate (AMC) resistance in Escherichia coli. In the present study, we investigated the population structure and virulence traits of clinical AMC-resistant E. coli strains expressing OXA-1 or IRT and compared these traits to those in a control group of clinical AMC-susceptible E. coli isolates. All OXA-1-producing (n = 67) and IRT-producing (n = 45) isolates were matched by geographical and temporal origin to the AMC-susceptible control set (n = 56). We performed multilocus sequence typing and phylogenetic group characterization for each isolate and then studied the isolates for the presence of 49 virulence factors (VFs) by PCR and sequencing. The most prevalent clone detected was distinct for each group: group C isolates of sequence type (ST) 88 (C/ST88) were the most common in OXA-1 producers, B2/ST131 isolates were the most common in IRT producers, and B2/ST73 isolates were the most common in AMC-susceptible isolates. The median numbers of isolates per ST were 3.72 in OXA-1 producers, 2.04 in IRT producers, and 1.69 in AMC-susceptible isolates; the proportions of STs represented by one unique isolate in each group were 19.4%, 31.1%, and 48.2%, respectively. The sum of all VFs detected, calculated as a virulence score, was significantly higher in AMC-susceptible isolates than OXA-1 and IRT producers (means, 12.5 versus 8.3 and 8.2, respectively). Our findings suggest that IRT- and OXA-1-producing E. coli isolates resistant to AMC have a different and less diverse population structure than AMC-susceptible clinical E. coli isolates. The AMC-susceptible population also contains more VFs than AMC-resistant isolates. PMID:24777096

  10. Clinical isolates of uropathogenic Escherichia coli ST131 producing NDM-7 metallo-β-lactamase in China.

    PubMed

    Wang, Lian-Hui; Liu, Pan-Pan; Wei, Dan-Dan; Liu, Yang; Wan, La-Gen; Xiang, Tian-Xin; Zhang, Yu-Juan

    2016-07-01

    Here we report five cases of NDM-7-producing Escherichia coli from patients with bacteriuria in a teaching hospital in mainland China. Two isolates belonged to sequence type 131 (ST131), simultaneously carrying blaCTX-M-15, blaSHV-11, blaTEM-1 and qnrS1. The blaNDM-7 gene was located on a conjugative IncX3-type plasmid bearing blaTEM-1 and qnrS1. These findings indicate the spread of NDM-7 metallo-β-lactamase in a highly resistant and virulent E. coli sequence type in China.

  11. High Prevalence of Escherichia coli-Producing CTX-M-15 Extended-Spectrum Beta-Lactamases in Poultry and Human Clinical Isolates in Romania.

    PubMed

    Maciuca, Iuliana E; Williams, Nicola J; Tuchilus, Cristina; Dorneanu, Olivia; Guguianu, Eleonora; Carp-Carare, Catalin; Rimbu, Cristina; Timofte, Dorina

    2015-12-01

    Use of antibiotics in food animals may contribute to development and spread of resistant organisms, particularly so in some countries. The aim of this study was two-fold; first, to establish the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in chicken production in a region within Romania. Second, to study the relatedness of ESBL-producing E. coli isolates recovered from broilers, abattoir workers where the chickens were slaughtered and from the human clinical specimens from two regional hospitals. The results indicated a very high (69%) rate of carriage of ESBL and AmpC-producing E. coli in chickens with 36% CTX-M producers. Sequencing showed that chickens in Romania have the highest worldwide prevalence (53%) of blaCTX-M-15 reported in poultry E. coli isolates. The majority (53%) of the extended-spectrum cephalosporin-resistant E. coli carried plasmid-mediated blaampC genes, mostly blaCMY-2 type, one of the highest prevalences reported in Europe. The predominant CTX-M type found in the human clinical E. coli isolates was blaCTX-M-15 and most isolates coharbored blaOXA-1, blaTEM, and aac(6')-ib-cr. The majority (60%) of the human clinical isolates belonged to the pandemic virulent clone B2-ST131. The clonal relationship between broiler and the human CTX-M-producing E. coli isolates was assessed by macrorestriction pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST), which indicated strain diversity with no common STs found between human and poultry isolates. Moreover, IncI1 was the most prevalent replicon found in broiler ESBL-producing E. coli isolates and also in transconjugants, indicating that plasmids and not clonal spread may play a role in the transfer of blaCTX-M genes. This study identifies a high prevalence of ESBL-producing E. coli from broiler chickens in Romania with a high occurrence incidence of blaCTX-M-15, which reflects the main ESBL type found in human E. coli infections in this

  12. Clinical profiles of patients colonized or infected with extended-spectrum beta-lactamase producing Enterobacteriaceae isolates: a 20 month retrospective study at a Belgian University Hospital

    PubMed Central

    2011-01-01

    Background Description of the clinical pictures of patients colonized or infected by ESBL-producing Enterobacteriaceae isolates and admitted to hospital are rather scarce in Europe. However, a better delineation of the clinical patterns associated with the carriage of ESBL-producing isolates may allow healthcare providers to identify more rapidly at risk patients. This matter is of particular concern because of the growing proportion of ESBL-producing Enterobacteriaceae species isolates worldwide. Methods We undertook a descriptive analysis of 114 consecutive patients in whom ESBL-producing Enterobacteriaceae isolates were collected from clinical specimens over a 20-month period. Clinical data were obtained through retrospective analysis of medical record charts. Microbiological cultures were carried out by standard laboratory methods. Results The proportion of ESBL-producing Enterobacteriaceae strains after exclusion of duplicate isolates was 4.5% and the incidence rate was 4.3 cases/1000 patients admitted. Healthcare-associated acquisition was important (n = 104) while community-acquisition was less frequently found (n = 10). Among the former group, two-thirds of the patients were aged over 65 years and 24% of these were living in nursing homes. Sixty-eight (65%) of the patients with healthcare-associated ESBL, were considered clinically infected. In this group, the number and severity of co-morbidities was high, particularly including diabetes mellitus and chronic renal insufficiency. Other known risk factors for ESBL colonization or infection such as prior antibiotic exposure, urinary catheter or previous hospitalisation were also often found. The four main diagnostic categories were: urinary tract infections, lower respiratory tract infections, septicaemia and intra-abdominal infections. For hospitalized patients, the median hospital length of stay was 23 days and the average mortality rate during hospitalization was 13% (Confidence Interval 95%: 7

  13. Practical agar-based disk potentiation test for detection of fosfomycin-nonsusceptible Escherichia coli clinical isolates producing glutathione S-transferases.

    PubMed

    Nakamura, Genki; Wachino, Jun-Ichi; Sato, Natsumi; Kimura, Kouji; Yamada, Keiko; Jin, Wanchun; Shibayama, Keigo; Yagi, Tetsuya; Kawamura, Kumiko; Arakawa, Yoshichika

    2014-09-01

    The number of reports concerning Escherichia coli clinical isolates that produce glutathione S-transferases responsible for fosfomycin resistance (FR-GSTs) has been increasing. We have developed a disk-based potentiation test in which FR-GST producers expand the growth inhibition zone around a Kirby-Bauer disk containing fosfomycin in combination with sodium phosphonoformate (PPF). PPF, an analog of fosfomycin, is a transition-state inhibitor of FosA(PA), a type of FR-GST from Pseudomonas aeruginosa. Considering its mechanism of action, PPF was expected to inhibit a variety of FR-GSTs. In the presence of PPF, zone enlargement around the disk containing fosfomycin was observed for FosA3-, FosA4-, and FosC2-producing E. coli clinical isolates. Moreover, the growth inhibition zone was remarkably enlarged when the Mueller-Hinton (MH) agar plate contained 25 μg/ml glucose-6-phosphate (G6P). When we retrospectively tested 12 fosfomycin-resistant (MIC, ≥256 μg/ml) E. coli clinical isolates from our hospital with the potentiation test, 6 FR-GST producers were positive phenotypically by potentiation disk and were positive for FR-GST genes: 5 harbored fosA3 and 1 harbored fosA4. To identify the production of FR-GSTs, we set the provisional cutoff value, 5-mm enlargement, by adding PPF to a fosfomycin disk on the MH agar plates containing G6P. Our disk-based potentiation test reliably identifies FR-GST producers and can be performed easily; therefore, it will be advantageous in epidemiological surveys and infection control of fosfomycin-resistant bacteria in clinical settings.

  14. Fatal S. aureus hemorrhagic pneumonia: genetic analysis of a unique clinical isolate producing both PVL and TSST-1.

    PubMed

    Li, Zhi; Stevens, Dennis L; Hamilton, Stephanie M; Parimon, Tanyalak; Ma, Yongsheng; Kearns, Angela M; Ellis, Richard W; Bryant, Amy E

    2011-01-01

    In 2008, an unusual strain of methicillin-sensitive Staphylococcus aureus (MSSA68111), producing both Panton-Valentine leukocidin (PVL) and toxic shock syndrome toxin-1 (TSST-1), was isolated from a fatal case of necrotizing pneumonia. Because PVL/TSST-1 co-production in S. aureus is rare, we characterized the molecular organization of these toxin genes in strain 68111. MSSA68111 carries the PVL genes within a novel temperate prophage we call ФPVLv68111 that is most similar, though not identical, to phage ФPVL--a phage type that is relatively rare worldwide. The TSST-1 gene (tst) in MSSA68111 is carried on a unique staphylococcal pathogenicity island (SaPI) we call SaPI68111. Features of SaPI68111 suggest it likely arose through multiple major recombination events with other known SaPIs. Both ФPVLv68111 and SaPI68111 are fully mobilizable and therefore transmissible to other strains. Taken together, these findings suggest that hypervirulent S. aureus have the potential to emerge worldwide.

  15. Genetic characterization of Shiga toxin-producing Escherichia coli O26:H11 strains isolated from animal, food, and clinical samples.

    PubMed

    Krüger, Alejandra; Lucchesi, Paula M A; Sanso, A Mariel; Etcheverría, Analía I; Bustamante, Ana V; Burgán, Julia; Fernández, Luciana; Fernández, Daniel; Leotta, Gerardo; Friedrich, Alexander W; Padola, Nora L; Rossen, John W A

    2015-01-01

    The Shiga-toxin producing Escherichia coli (STEC) may cause serious illness in human. Here we analyze O26:H11 strains known to be among the most reported STEC strains causing human infections. Genetic characterization of strains isolated from animal, food, and clinical specimens in Argentina showed that most carried either stx 1a or stx 2a subtypes. Interestingly, stx 2a-positive O26:H11 rarely isolated from cattle in other countries showed to be an important proportion of O26:H11 strains circulating in cattle and food in our region. Seventeen percent of the isolates harbored more than one gene associated with antimicrobial resistance. In addition to stx, all strains contained the virulence genes eae-β, tir, efa, iha, espB, cif, espA, espF, espJ, nleA, nleB, nleC, and iss; and all except one contained ehxA, espP, and cba genes. On the other hand, toxB and espI genes were exclusively observed in stx 2-positive isolates, whereas katP was only found in stx 1a-positive isolates. Our results show that O26:H11 STEC strains circulating in Argentina, including those isolated from humans, cattle, and meat products, present a high pathogenic potential, and evidence that cattle can be a reservoir of O26:H11 strains harboring stx 2a.

  16. Genetic characterization of Shiga toxin-producing Escherichia coli O26:H11 strains isolated from animal, food, and clinical samples

    PubMed Central

    Krüger, Alejandra; Lucchesi, Paula M. A.; Sanso, A. Mariel; Etcheverría, Analía I.; Bustamante, Ana V.; Burgán, Julia; Fernández, Luciana; Fernández, Daniel; Leotta, Gerardo; Friedrich, Alexander W.; Padola, Nora L.; Rossen, John W. A.

    2015-01-01

    The Shiga-toxin producing Escherichia coli (STEC) may cause serious illness in human. Here we analyze O26:H11 strains known to be among the most reported STEC strains causing human infections. Genetic characterization of strains isolated from animal, food, and clinical specimens in Argentina showed that most carried either stx1a or stx2a subtypes. Interestingly, stx2a-positive O26:H11 rarely isolated from cattle in other countries showed to be an important proportion of O26:H11 strains circulating in cattle and food in our region. Seventeen percent of the isolates harbored more than one gene associated with antimicrobial resistance. In addition to stx, all strains contained the virulence genes eae-β, tir, efa, iha, espB, cif, espA, espF, espJ, nleA, nleB, nleC, and iss; and all except one contained ehxA, espP, and cba genes. On the other hand, toxB and espI genes were exclusively observed in stx2-positive isolates, whereas katP was only found in stx1a-positive isolates. Our results show that O26:H11 STEC strains circulating in Argentina, including those isolated from humans, cattle, and meat products, present a high pathogenic potential, and evidence that cattle can be a reservoir of O26:H11 strains harboring stx2a. PMID:26539413

  17. Characterization of Plasmid-Mediated Quinolone Resistance (PMQR) Genes in Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae Pediatric Clinical Isolates in Mexico

    PubMed Central

    Silva-Sánchez, Jesus; Cruz-Trujillo, Enrique; Barrios, Humberto; Reyna-Flores, Fernando; Sánchez-Pérez, Alejandro; Garza-Ramos, Ulises

    2013-01-01

    This work describes the characterization of plasmid-mediated quinolone-resistance (PMQR) genes from a multicenter study of ESBL-producing Enterobacteriaceae pediatric clinical isolates in Mexico. The PMQR gene-positive isolates were characterized with respect to ESBLs, and mutations in the GyrA and ParC proteins were determined. The phylogenetic relationship was established by PFGE and the transfer of PMQR genes was determined by mating assays. The prevalence of the PMQR genes was 32.1%, and the rate of qnr-positive isolates was 15.1%; 93.3% of the latter were qnrB and 6.4% were qnrA1. The distribution of isolates in terms of bacterial species was as follows: 23.5% (4/17) corresponded to E. cloacae, 13.7% (7/51) to K. pneumoniae, and 13.6% (6/44) to E. coli. In addition, the prevalence of aac(6’)-Ib-cr and qepA was 15.1% and 1.7%, respectively. The molecular characteristics of qnr- and qepA-positive isolates pointed to extended-spectrum β-lactamase (ESBL) CTX-M-15 as the most prevalent one (70.5%), and to SHV-12 in the case of aac(6’)-Ib-cr-positive isolates. GyrA mutations at codons Ser-83 and Asp-87, and ParC mutations at codons Ser-80 were observed in 41.1% and 35.2% of the qnr-positive isolates, respectively. The analysis of the transconjugants revealed a co-transmission of blaCTX-M-15 with the qnrB alleles. In general, the prevalence of PMQR genes (qnr and aac(6’)-Ib-cr) presented in this work was much lower in the pediatric isolates, in comparison to the adult isolates in Mexico. Also, ESBL CTX-M-15 was the main ESBL identified in the pediatric isolates, whereas in the adult ones, ESBLs corresponded to the CTX-M and the SHV families. In comparison with other studies, among the PMQR-genes identified in this study, the qnrB-alleles and the aac(6’)-Ib-cr gene were the most prevalent, whereas the qnrS1, qnrA1 and qnrB-like alleles were the most prevalent in China and Uruguay. PMID:24147104

  18. Survey of Clinical Extended-Spectrum Beta-Lactamase-Producing Enterobacter cloacae Isolates in a Chinese Tertiary Hospital, 2012-2014.

    PubMed

    Cao, Xiao-Li; Cheng, Li; Zhang, Zhi-Feng; Ning, Ming-Zhe; Zhou, Wan-Qing; Zhang, Kui; Shen, Han

    2017-01-01

    A total of 72 consecutive and nonduplicate clinical extended-spectrum β-lactamase (ESBL)-producing Enterobacter cloacae isolates were collected from our hospital from 2012 to 2014 for analyzing the prevalence of plasmid-mediated quinolone resistance (PMQR) genes, 16S rRNA methyltransferase (16S-RMTase) encoding genes, and carbapenem-hydrolyzing β-lactamase (CHβL) genes, as well as integrons. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were carried out to characterize the genetic relatedness. The isolates mainly harbored blaCTX-M (n = 51, 70.8%) and blaSHV (n = 46, 63.9%) genes. High prevalence of PMQR genes qnrA1 (n = 24, 33.3%), qnrB (n = 4, 5.6%), qnrS1 (n = 2, 2.8%), and aac(6')-Ib-cr (n = 21, 29.2%) was observed. Furthermore, CHβLs IMP-4 (n = 6, 8.3%) and IMP-8 (n = 4, 5.6%), as well as class I integrons (n = 29, 40.3%), were found in the ESBL-producing E. cloacae isolates. PFGE revealed 69 pulsotypes. MLST distinguished 44 sequence types (STs) with ST124 (n = 7, 9.7%), ST50 (n = 3, 4.2%), ST45 (n = 3, 4.2%), and ST93 (n = 3, 4.2%) being the predominant STs. The results indicate a possible clonal transmission of ST124 isolates in the hospital that needs further surveillance. The genetic diversity of the other numerous distinctive STs indicates that most of the ESBL-producing E. cloacae in our hospital might arise through stepwise accumulations of multiple drug-resistance determinants in different clones.

  19. Characterisation of a haemolysin related to Vp-TDH produced by a Kanagawa phenomenon-negative clinical isolate of Vibrio parahaemolyticus.

    PubMed

    Nagayama, K; Yamamoto, K; Mitawani, T; Honda, T

    1995-02-01

    The production of a family of haemolysins--thermostable direct haemolysin (Vp-TDH), Vp-TDH-related haemolysin (Vp-TRH) and Vp-TDH/I--has been reported in clinical isolates of Vibrio parahaemolyticus. This paper describes a fourth type of haemolysin--Vp-TDH/II--produced by a Kanagawa phenomenon-negative clinical isolate of V. parahaemolyticus (O13:K, untypable). Vp-TDH/II was purified by ammonium sulphate precipitation and successive filtrations on DEAE-cellulose, hydroxyapatite, Sepharose 4B and Mono Q columns. Vp-TDH/II was biophysicochemically and immunologically similar to, but not identical to Vp-TDH, Vp-TRH and Vp-TDH/I. Vp-TDH/II stimulated vascular permeability in rabbit skin and was lethal to mice. Purified Vp-TDH/II and viable cells of the Vp-TDH/II-producing strain both induced fluid accumulation in ligated rabbit intestine. The plasmid-determined structural gene for Vp-TDH/II was cloned and the nucleotide sequence determined. The deduced amino acid sequence of Vp-TDH/II differed from those of Vp-TDH, Vp-TRH and Vp-TDH/I.

  20. Nosocomial Outbreak of VIM-1-Producing Klebsiella pneumoniae Isolates of Multilocus Sequence Type 15: Molecular Basis, Clinical Risk Factors, and Outcome

    PubMed Central

    Sánchez-Romero, Isabel; Asensio, Ángel; Muñoz-Algarra, María; Isidoro, Beatriz; Vindel, Ana; Álvarez-Avello, José; Balandín-Moreno, Bárbara; Cuevas, Oscar; Fernández-Romero, Sara; Azañedo, Luisa; Sáez, David; Campos, José

    2012-01-01

    We study the epidemiology, molecular basis, clinical risk factors, and outcome involved in the clonal dissemination of VIM-1-producing Klebsiella pneumoniae isolates in the hospital setting. All patients infected/colonized by carbapenem-nonsusceptible K. pneumoniae (CNSKP) in 2009 were included. Molecular epidemiology was studied by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Antibiotic resistance genes were analyzed by PCR and sequencing. Plasmids were studied by PFGE with S1 nuclease digestion and for incompatibility group by a PCR-based replicon typing scheme. Risk factors associated with CNSKP colonization/infection were assessed by an observational case-control study. All 55 patients studied were infected (n = 28) or colonized (n = 27) by VIM-1-producing K. pneumoniae. All but one acquired isolates of a single clone (PFGE cluster 1 [C1], sequence type 15 [ST15]), while another clone (PFGE C2, ST340) was detected in four patients. C1 isolates also produced the new extended-spectrum β-lactamase SHV-134. blaVIM-1 was carried in a class 1 integron and an untypeable plasmid of ∼50 bp. The number of days that the patient received mechanical ventilation, the use of parenteral nutrition, previous treatment with linezolid, and treatment with extended-spectrum cephalosporins for more than 7 days were detected to be independent risk factors for CNSKP acquisition. The VIM-1-producing K. pneumoniae ST15 clone has a high capacity to spread among intensive care unit patients with severe underlying conditions. A high rate of associated mortality and great difficulty in controlling the spread of this clone, without permanent behavioral changes in the personnel, were observed. PMID:22005997

  1. Effects of Slime Produced by Clinical Isolates of Coagulase-Negative Staphylococci on Activities of Various Antimicrobial Agents

    PubMed Central

    Souli, Maria; Giamarellou, Helen

    1998-01-01

    A novel in vitro semiquantitative method was developed to investigate the influence of staphylococcal slime on the activities of 22 antimicrobial agents. Pefloxacin, teicoplanin, and vancomycin demonstrated remarkable decreases in efficacy: 30, 52, and 63%, respectively. The activity of rifampin was not significantly reduced (0.99%), whereas all other agents tested were modestly affected (<15% decrease). These data could be influential in the treatment of implant-associated infections caused by slime-producing staphylococci. PMID:9559814

  2. Recombinant Scorpine Produced Using SUMO Fusion Partner in Escherichia coli Has the Activities against Clinically Isolated Bacteria and Inhibits the Plasmodium falciparum Parasitemia In Vitro

    PubMed Central

    Gu, Yaping; Zhou, Huayun; Cao, Jun; Gao, Qi

    2014-01-01

    Scorpine, a small cationic peptide from the venom of Pandinus imperator, which has been shown to have anti-bacterial and anti-plasmodial activities, has potential important applications in the pharmaceutical industries. However, the isolation of scorpine from natural sources is inefficient and time-consuming. Here, we first report the expression and purification of recombinant scorpine in Escherichia coli, using small ubiquitin-related modifier (SUMO) fusion partner. The fusion protein was expressed in soluble form in E. coli, and expression was verified by SDS-PAGE and western blotting analysis. The fusion protein was purified to 90% purity by nickel–nitrilotriacetic acid (Ni2+–NTA) resin chromatography. After the SUMO-scorpine fusion protein was cleaved by the SUMO protease, the cleaved sample was reapplied to a Ni2+–NTA column. Tricine/SDS-PAGE gel results indicated that Scorpine had been purified successfully to more than 95% purity. The recombinantly expressed Scorpine showed anti-bacterial activity against two standard bacteria including Staphylococcus aureus ATCC 29213 and Acinetobacter baumannii ATCC 19606, and clinically isolated bacteria including S. aureus S, S. aureus R, A. baumannii S, and A. baumannii R. It also produced 100% reduction in Plasmodium falciparum parasitemia in vitro. Thus, the expression strategy presented in this study allowed convenient high yield and easy purification of recombinant Scorpine for pharmaceutical applications in the future. PMID:25068263

  3. Enterotoxigenic profiling of emetic toxin- and enterotoxin-producing Bacillus cereus, Isolated from food, environmental, and clinical samples by multiplex PCR.

    PubMed

    Forghani, Fereidoun; Kim, Jung-Beom; Oh, Deog-Hwan

    2014-11-01

    Bacillus cereus comprises the largest group of endospore-forming bacteria and can cause emetic and diarrheal food poisoning. A total of 496 B. cereus strains isolated from various sources (food, environmental, clinical) were assessed by a multiplex PCR for the presence of enterotoxin genes. The detection rate of nheA, entFM, hblC, and cytK enterotoxin genes among all B. cereus strains was 92.33%, 77.21%, 59.47%, and 47.58%, respectively. Enterotoxigenic profiles were determined in emetic toxin- (8 patterns) and enterotoxin-producing strains (12 patterns). The results provide important information on toxin prevalence and toxigenic profiles of B. cereus from various sources. Our findings revealed that B. cereus must be considered a serious health hazard and Bacillus thuringiensis should be considered of a greater potential concern to food safety among all B. cereus group members. Also, there is need for intensive and continuous monitoring of products embracing both emetic toxin and enterotoxin genes.

  4. Limits of patient isolation measures to control extended-spectrum beta-lactamase–producing Enterobacteriaceae: model-based analysis of clinical data in a pediatric ward

    PubMed Central

    2013-01-01

    Background Extended-spectrum beta-lactamase–producing Enterobacteriaceae (ESBL-E) are a growing concern in hospitals and the community. How to control the nosocomial ESBL-E transmission is a matter of debate. Contact isolation of patients has been recommended but evidence supporting it in non-outbreak settings has been inconclusive. Methods We used stochastic transmission models to analyze retrospective observational data from a two-phase intervention in a pediatric ward, successively implementing single-room isolation and patient cohorting in an isolation ward, combined with active ESBL-E screening. Results For both periods, model estimates suggested reduced transmission from isolated/cohorted patients. However, most of the incidence originated from sporadic sources (i.e. independent of cross-transmission), unaffected by the isolation measures. When sporadic sources are high, our model predicted that even substantial efforts to prevent transmission from carriers would have limited impact on ESBL-E rates. Conclusions Our results provide evidence that, considering the importance of sporadic acquisition, e.g. endogenous selection of resistant strains following antibiotic treatment, contact-isolation measures alone might not suffice to control ESBL-E. They also support the view that estimating cross-transmission extent is key to predicting the relative success of contact-isolation measures. Mathematical models could prove useful for those estimations and guide decisions concerning the most effective control strategy. PMID:23618041

  5. Occurrence and molecular characterization of Klebsiella pneumoniae ST37 clinical isolates producing plasmid-mediated AmpC recovered over a 3-year period.

    PubMed

    Illiaquer, Marina; Caroff, Nathalie; Bémer, Pascale; Aubin, Guillaume G; Juvin, Marie-Emmanuelle; Lepelletier, Didier; Reynaud, Alain; Corvec, Stéphane

    2012-09-01

    We investigated the clinical and microbiological epidemiology of AmpC plasmidic cephalosporinases (pAmpC) in Klebsiella pneumoniae strains resistant to ceftazidime, during a 3-year period (2007-2009). Among 1505 K. pneumoniae, 7 were pAmpC producers. Molecular characterization revealed the spread of a ST37 strain producing DHA-1 within intensive care units and the diffusion of the same plasmid among unrelated strains.

  6. In vitro susceptibility of multi-drug resistant Pseudomonas aeruginosa and extended-spectrum β-lactamase-producing Klebsiella pneumoniae isolated from clinical specimens at Bugando Medical Centre, Tanzania to Piperacillin-Tazobactam.

    PubMed

    Petro, Daudi; Mushi, Martha F; Moremi, Nyambura; Iddi, Shabani; Mirambo, Mariam; Seni, Jeremiah; Mshana, Stephen E

    2014-01-01

    Pseudomonas spp. and Klebsiella pneumoniae are common causes of serious health care associated infections (HCAIs) worldwide. The treatment options for infections caused by multi-drug resistant (MDR) organisms are limited to tigecycline and carbapenems. A total of 172 isolates of multi-drug resistant Pseudomonas. spp and extended-spectrum β- (ESBL) producing Klebsiella pneumoniae isolated from clinical specimens at the Bugando Medical Centre were tested for their in vitro susceptibility to piperacillin-tazobactam 100/10μg using disc diffusion test as recommended by Clinical Laboratory Standard Institute (CLSI). Out of 59 multi-drug resistant Pseudomonas spp, 54 (92.0%) were susceptible to piperacillin-tazobactam while of 113 ESBL producing Klebsiella pneumoniae, 55 (48.7%) were susceptible to piperacillin-tazobactam 100/10μg. Also, 20 (34.0%) of the Pseudomonas spp were both ESBL producers and susceptible to piperacillin-tazobactam 100/10μg. A significant proportion of Pseudomonas spp isolates from clinical specimens in our setting are susceptible to piperacillin/tazobactam. This study shows that piperacillin-tazobactam offer a better option to clinicians for the treatment of health care associated infections due to Pseudomonas spp. and ESBL producing Klebsiella pneumoniae in our setting and other health facilities where these organisms are of significance.

  7. [Drug sensitivity and beta-lactamase producibility of various types of bacteria clinically isolated during the period from December 1999 to February 2000].

    PubMed

    Hashimoto, Kouji; Kinosita, Chie; Yoshinaga, Hideko; Sonda, Yukari; Itoyama, Takako; Oyamada, Kazunori; Kajimura, Katsunari; Kondou, Masaharu; Sagawa, Kimitaka; Ouno, Tadashi; Kawamoto, Keiko; Souda, Katsumi; Hara, Kazumi; Kakihara, Miyako; Tanaka, Tetsuo; Ryutou, Miwako; Shichiji, Akiko; Nakashima, Kayoko; Ishibashi, Kazushige; Tabira, Reiko; Yamamoto, Shigeko; Nishida, Masahiro; Tsutsumi, Yasunori

    2002-09-01

    beta-Lactamase activity and drug sensitivity were measured in 744 strains from 8 species of bacteria isolated at medical institutions in Chikugo District of Fukuoka Prefecture during the period from December 1999 to February 2000. Nitrocefin test revealed that beta-lactamase was positive in 48% of S. aureus, 7% of H. influenzae, and 92% of M. catarrhalis, and acidometry revealed that penicillinase/cephalosporinase were positive in 13%/14% of E. coli, 22%/8% of K. pneumoniae, 47%/97% of E. cloacae, 3%/65% of S. marcescens, and 10%/36% of P. aeruginosa. Based on the assessment of the MIC values of various types of antibacterial drugs for beta-lactamase-producing strains, there were 11 strains (1 strain of K. pneumonia, 6 strains of E. cloacae, and 4 strains of P. aeruginosa) of class-B beta-lactamase-producing bacteria out of a total of 496 strains of Enterobacteriaceae and Pseudomonas aeruginosa. The results of PCR analysis suggested that 1 strain of K. pneumonia, 1 strain of E. cloacae, and 4 strains of P. aeruginosa produced metallo-beta-lactamase. There was no strain (E. coli and K. pneumoniae) of ESBL-producing bacteria. BLNAR strains, on the other hand, were found in 9% (9/100) of H. influenzae.

  8. In vitro potentiation of carbapenems with ME1071, a novel metallo-beta-lactamase inhibitor, against metallo-beta-lactamase- producing Pseudomonas aeruginosa clinical isolates.

    PubMed

    Ishii, Yoshikazu; Eto, Maki; Mano, Yoko; Tateda, Kazuhiro; Yamaguchi, Keizo

    2010-09-01

    ME1071, a maleic acid derivative, is a novel specific inhibitor for metallo-beta-lactamases (MBL). In this study, the potentiation of ME1071 in combination with several beta-lactams was evaluated using MBL-producing Pseudomonas aeruginosa isolates. The rates of susceptibility of MBL producers to carbapenems (imipenem, biapenem, and doripenem) and ceftazidime were increased by 8 to 27% in the presence of 32 microg/ml of ME1071. The corresponding resistance rates were decreased by 13 to 46%, respectively. On the other hand, ME1071 showed weaker or no potentiation with non-MBL producers. The K(i) value of ME1071 for IMP-1 was 0.4 microM, significantly lower than the K(m) values of carbapenems for the IMP-1 enzyme. On the other hand, the K(i) value of ME1071 for VIM-2 was 120 microM, higher than the K(m) values of carbapenems for the VIM-2 enzyme. Results of this study indicate that ME1071 can potentiate the activity of ceftazidime and carbapenems against MBL-producing strains of P. aeruginosa.

  9. Emergence in Spain of a Multidrug-Resistant Enterobacter cloacae Clinical Isolate Producing SFO-1 Extended-Spectrum β-Lactamase▿

    PubMed Central

    Fernández, Ana; Pereira, María José; Suárez, José Manuel; Poza, Margarita; Treviño, Mercedes; Villalón, Pilar; Sáez-Nieto, Juan Antonio; Regueiro, Benito José; Villanueva, Rosa; Bou, Germán

    2011-01-01

    Between February 2006 and October 2009, 38 patients in different wards at the A Coruña University Hospital (northwest Spain) were either infected with or colonized by an epidemic, multidrug-resistant (MDR), and extended-spectrum-β-lactamase (ESBL)-producing strain of Enterobacter cloacae (EbSF), which was susceptible only to carbapenems. Semiautomated repetitive extragenic palindromic sequence-based PCR (rep-PCR) and pulsed-field gel electrophoresis (PFGE) analysis revealed that all of the E. cloacae isolates belonged to the same clone. Cloning and sequencing enabled the detection of the SFO-1 ESBL in the epidemic strain and the description of its genetic environment. The presence of the ampR gene was detected upstream of blaSFO-1, and two complete sequences of IS26 surrounding ampR and ampA were detected. These IS26 sequences are bordered by complete left and right inverted repeats (IRL and IRR, respectively), which suggested that they were functional. The whole segment flanked by two IS26 copies may be considered a putative large composite transposon. A gene coding for aminoglycoside acetyltransferase (gentamicin resistance gene [aac3]) was found downstream of the 3′ IS26. Despite the implementation of strict infection control measures, strain EbSF spread through different areas of the hospital. A case-control study was performed to assess risk factors for EbSF acquisition. A multivariate analysis revealed that the prior administration of β-lactam antibiotics, chronic renal failure, tracheostomy, and prior hospitalization were statistically associated with SFO-1-producing E. cloacae acquisition. This study describes for the first time an outbreak in which an SFO-1-producing E. cloacae strain was involved. Note that so far, this β-lactamase has previously been isolated in only a single case of E. cloacae infection in Japan. PMID:21227991

  10. Diversity of Capsular Polysaccharide Gene Clusters in Kpc-Producing Klebsiella pneumoniae Clinical Isolates of Sequence Type 258 Involved in the Italian Epidemic

    PubMed Central

    D’Andrea, Marco Maria; Amisano, Francesco; Giani, Tommaso; Conte, Viola; Ciacci, Nagaia; Ambretti, Simone; Santoriello, Luisa; Rossolini, Gian Maria

    2014-01-01

    Strains of Klebsiella pneumoniae producing KPC-type beta-lactamases (KPC-Kp) are broadly disseminating worldwide and constitute a major healthcare threat given their extensively drug resistant phenotypes and ability to rapidly disseminate in healthcare settings. In this work we report on the characterization of two different capsular polysaccharide (CPS) gene clusters, named cpsBO-4 and cps207-2, from two KPC-Kp clinical strains from Italy belonging in sequence type (ST) 258, which is one of the most successful ST of KPC-Kp spreading worldwide. While cpsBO-4 was different from known 78 K-types according to the recently proposed typing schemes based on the wzi or wzc gene sequences, cps207-2 was classified as K41 by one of these methods. Bioinformatic analysis revealed that they were represented in the genomic sequences of KPC-Kp from strains of ST258 from different countries, and cpsBO-4 was also detected in a KPC-Kp strain of ST442 from Brazil. Investigation of a collection of 46 ST258 and ST512 (a single locus variant of ST258) clinical strains representative of the recent Italian epidemic of KPC-Kp by means of a multiplex PCR typing approach revealed that cpsBO-4 was the most prevalent type, being detected both in ST258 and ST512 strains with a countrywide distribution, while cps207-2 was only detected in ST258 strains with a more restricted distribution. PMID:24823690

  11. Diversity of capsular polysaccharide gene clusters in Kpc-producing Klebsiella pneumoniae clinical isolates of sequence type 258 involved in the Italian epidemic.

    PubMed

    D'Andrea, Marco Maria; Amisano, Francesco; Giani, Tommaso; Conte, Viola; Ciacci, Nagaia; Ambretti, Simone; Santoriello, Luisa; Rossolini, Gian Maria

    2014-01-01

    Strains of Klebsiella pneumoniae producing KPC-type beta-lactamases (KPC-Kp) are broadly disseminating worldwide and constitute a major healthcare threat given their extensively drug resistant phenotypes and ability to rapidly disseminate in healthcare settings. In this work we report on the characterization of two different capsular polysaccharide (CPS) gene clusters, named cpsBO-4 and cps207-2, from two KPC-Kp clinical strains from Italy belonging in sequence type (ST) 258, which is one of the most successful ST of KPC-Kp spreading worldwide. While cpsBO-4 was different from known 78 K-types according to the recently proposed typing schemes based on the wzi or wzc gene sequences, cps207-2 was classified as K41 by one of these methods. Bioinformatic analysis revealed that they were represented in the genomic sequences of KPC-Kp from strains of ST258 from different countries, and cpsBO-4 was also detected in a KPC-Kp strain of ST442 from Brazil. Investigation of a collection of 46 ST258 and ST512 (a single locus variant of ST258) clinical strains representative of the recent Italian epidemic of KPC-Kp by means of a multiplex PCR typing approach revealed that cpsBO-4 was the most prevalent type, being detected both in ST258 and ST512 strains with a countrywide distribution, while cps207-2 was only detected in ST258 strains with a more restricted distribution.

  12. Four Main Virotypes among Extended-Spectrum-β-Lactamase-Producing Isolates of Escherichia coli O25b:H4-B2-ST131: Bacterial, Epidemiological, and Clinical Characteristics

    PubMed Central

    Mora, Azucena; Mamani, Rosalia; López, Cecilia; Blanco, Miguel; Dahbi, Ghizlane; Herrera, Alexandra; Marzoa, Juan; Fernández, Val; de la Cruz, Fernando; Martínez-Martínez, Luis; Alonso, María Pilar; Nicolas-Chanoine, Marie-Hélène; Johnson, James R.; Johnston, Brian; López-Cerero, Lorena; Pascual, Álvaro; Rodríguez-Baño, Jesús

    2013-01-01

    A total of 1,021 extended-spectrum-β-lactamase-producing Escherichia coli (ESBLEC) isolates obtained in 2006 during a Spanish national survey conducted in 44 hospitals were analyzed for the presence of the O25b:H4-B2-ST131 (sequence type 131) clonal group. Overall, 195 (19%) O25b-ST131 isolates were detected, with prevalence rates ranging from 0% to 52% per hospital. Molecular characterization of 130 representative O25b-ST131 isolates showed that 96 (74%) were positive for CTX-M-15, 15 (12%) for CTX-M-14, 9 (7%) for SHV-12, 6 (5%) for CTX-M-9, 5 (4%) for CTX-M-32, and 1 (0.7%) each for CTX-M-3 and the new ESBL enzyme CTX-M-103. The 130 O25b-ST131 isolates exhibited relatively high virulence scores (mean, 14.4 virulence genes). Although the virulence profiles of the O25b-ST131 isolates were fairly homogeneous, they could be classified into four main virotypes based on the presence or absence of four distinctive virulence genes: virotypes A (22%) (afa FM955459 positive, iroN negative, ibeA negative, sat positive or negative), B (31%) (afa FM955459 negative, iroN positive, ibeA negative, sat positive or negative), C (32%) (afa FM955459 negative, iroN negative, ibeA negative, sat positive), and D (13%) (afa FM955459 negative, iroN positive or negative, ibeA positive, sat positive or negative). The four virotypes were also identified in other countries, with virotype C being overrepresented internationally. Correspondingly, an analysis of XbaI macrorestriction profiles revealed four major clusters, which were largely virotype specific. Certain epidemiological and clinical features corresponded with the virotype. Statistically significant virotype-specific associations included, for virotype B, older age and a lower frequency of infection (versus colonization), for virotype C, a higher frequency of infection, and for virotype D, younger age and community-acquired infections. In isolates of the O25b:H4-B2-ST131 clonal group, these findings uniquely define four main

  13. Synthesis and antimicrobial activity of small cationic amphipathic aminobenzamide marine natural product mimics and evaluation of relevance against clinical isolates including ESBL-CARBA producing multi-resistant bacteria.

    PubMed

    Igumnova, Elizaveta M; Mishchenko, Ekaterina; Haug, Tor; Blencke, Hans-Matti; Sollid, Johanna U Ericson; Fredheim, Elizabeth G Aarag; Lauksund, Silje; Stensvåg, Klara; Strøm, Morten B

    2016-11-15

    A library of small aminobenzamide derivatives was synthesised to explore a cationic amphipathic motif found in marine natural antimicrobials. The most potent compound E23 displayed minimal inhibitory concentrations (MICs) of 0.5-2μg/ml against several Gram-positive bacterial strains, including methicillin resistant Staphylococcus epidermidis (MRSE).E23 was also potent against 275 clinical isolates including Staphylococcus aureus, Enterococcus spp., Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae, as well as methicillin-resistant S. aureus (MRSA), vancomycin-resistant enterococci (VRE), and ESBL-CARBA producing multi-resistant Gram-negative bacteria. The study demonstrates how structural motifs found in marine natural antimicrobials can be a valuable source for making novel antimicrobial lead-compounds.

  14. SLM Produced Hermetically Sealed Isolation Valve

    NASA Technical Reports Server (NTRS)

    Richard, James

    2014-01-01

    Marshall Space Flight Center (MSFC) has developed a valve concept to replace traditional pyrotechnic-driven isolation valves. This paper will describe the valve design and development process. The valve design uses a stem/wedge to support a disk inside the valve. That disk hermetically seals the pressurized fluids. A release mechanism holds the stem/wedge and a large spring in place. When required to open, a solenoid is energized and pulls the release mechanism allowing the spring to pull the stem/wedge away from the disk. Now the disk is unsupported and the pressure ruptures the disk allowing flow to the outlet of the valve. This paper will provide details of this design, describe the development testing, and show the results from the valve level tests performed. Also, a trade study is presented to show the advantages of this design to a conventional pyrotechnic-based valve.

  15. SLM Produced Hermetically Sealed Isolation Valve

    NASA Technical Reports Server (NTRS)

    Richard, James A.

    2014-01-01

    Marshall Space Flight Center (MSFC) has developed a valve concept to replace traditional pyrotechnic driven isolation valves. This paper will describe the valve design and development process. The valve design uses a stem/wedge to support a disk inside the valve. That disk hermetically seals the pressurized fluids. A release mechanism holds the stem/wedge and a large spring in place. When required to open, a solenoid is energized and pulls the release mechanism allowing the spring to pull the stem/wedge away from the disk. Now the disk is unsupported and the pressure ruptures the disk allowing flow to the outlet of the valve. This paper will provide details of this design, describe the development testing, and show the results from the valve level tests performed. Also, a trade study is presented to show the advantages of this design to a conventional pyrotechnic based valve.

  16. Polysaccharide-producing bacteria isolated from paper machine slime deposits.

    PubMed

    Rättö, M; Suihko, M-L; Siika-aho, M

    2005-03-01

    Development of novel enzymatic methods for slime deposit control in paper mills requires knowledge of polysaccharide-producing organisms and the polysaccharide structures present in deposits. In this work, 27 polysaccharide-producing bacteria were isolated from slime samples collected from different parts of a paper machine. Most of the isolates produced polysaccharides in liquid culture and nine of them were selected for production of polysaccharides for characterisation. The selected isolates belonged to seven different genera: Bacillus, Brevundimonas, Cytophaga, Enterobacter, Klebsiella, Paenibacillus and Starkeya. Using ribotyping, partial 16S rDNA sequencing, physiological tests and fatty acid analysis, four of the nine isolates: Bacillus cereus, Brevundimonas vesicularis, K. pneumoniae and P. stellifer were identified to the species level. Production of polysaccharides by the selected isolates varied between 0.07 and 1.20 g L(-1), the highest amount being produced by B. vesicularis. The polysaccharides were heteropolysaccharides with varying proportions of galactose, glucose mannose, rhamnose fucose and uronic acids.

  17. Identification and characterization of nine atypical Candida dubliniensis clinical isolates.

    PubMed

    Albaina, Olatz; Sahand, Ismail H; Brusca, María I; Sullivan, Derek J; Fernández de Larrinoa, Iñigo; Moragues, María D

    2015-02-01

    Candida dubliniensis is a pathogenic yeast of the genus Candida closely related to Candida albicans. The phenotypic similarity of these two species often leads to misidentification of C. dubliniensis isolates in clinical samples. DNA-based methods continue to be the most effective means of discriminating accurately between the two species. Here, we report on the identification of nine unusual Candida isolates that showed ambiguous identification patterns on the basis of their phenotypic and immunological traits. The isolates were categorized into two groups. Group I isolates were unable to produce germ tubes and chlamydospores, and to agglutinate commercial latex particles coated with a mAb highly specific for C. dubliniensis. Group II isolates grew as pink and white colonies on CHROMagar Candida and ChromID Candida, respectively. Carbohydrate assimilation profiles obtained with API/ID32C together with PCR amplification with specific primers and DNA sequencing allowed reliable identification of the nine unusual clinical isolates as C. dubliniensis.

  18. Genome of the carbapenemase-producing clinical isolate Elizabethkingia miricola EM_CHUV and comparative genomics with Elizabethkingia meningoseptica and Elizabethkingia anophelis: evidence for intrinsic multidrug resistance trait of emerging pathogens.

    PubMed

    Opota, Onya; Diene, Seydina M; Bertelli, Claire; Prod'hom, Guy; Eckert, Philippe; Greub, Gilbert

    2017-01-01

    Elizabethkingia miricola is a Gram-negative non-fermenting rod emerging as a life-threatening human pathogen. The multidrug-resistant (MDR) carbapenemase-producing clinical isolate E. miricola EM_CHUV was recovered in the setting of severe nosocomial pneumonia. In this study, the genome of E. miricola EM_CHUV was sequenced and a functional analysis was performed, including a comparative genomic study with Elizabethkingia meningoseptica and Elizabethkingia anophelis. The resistome of EM_CHUV revealed the presence of a high number of resistance genes, including the presence of the blaGOB-13 and blaB-9 carbapenemase-encoding genes. Twelve mobility genes, with only two of them located in the proximity of resistance genes, and four potential genomic islands were identified in the genome of EM_CHUV, but no prophages or CRISPR sequences. Ten restriction-modification system (RMS) genes were also identified. In addition, we report the presence of a putative conjugative plasmid (pEM_CHUV) that does not encode any antibiotic resistance genes. Altogether, these findings point towards a limited number of DNA exchanges with other bacteria and suggest that multidrug resistance is an intrinsic trait of E. miricola owing to the presence of a high number of resistance genes within the bacterial core genome.

  19. Molecular mechanisms of carbapenem resistance in Enterobacter cloacae clinical isolates from Korea and clinical outcome.

    PubMed

    Lee, Yangsoon; Choi, Heekyeong; Yum, Jong Hwa; Kang, Girung; Bae, Il Kwon; Jeong, Seok Hoon; Lee, Kyungwon

    2012-01-01

    We investigated the molecular mechanisms of carbapenem resistance in clinical isolates of Enterobacter cloacae and their clinical characteristics. Nonreplicable E. cloacae isolates were recovered from six cancer patients and one patient with liver cirrhosis at a tertiary-care hospital in Korea between 2002 and 2009. Two patients who were considered to have a true infection caused by these microorganisms have died. All isolates produced AmpC β-lactamases, including ACT-1, ACT-2, MIR-3 and DHA-1, and CTX-M- or SHV-type extended-spectrum β-lactamase. Two isolates produced plasmid-borne VIM-2 carbapenemase. All probes specific for bla(AmpC) genes hybridized with I-CeuI chromosomal fragments were also recognized by a probe specific for 16S rDNA, suggesting a chromosomal location. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that a major outer membrane protein, OmpF, was absent in all isolates. PFGE of XbaI-digested DNA were considered to be unrelated. The results of our study suggest that the chromosomal AmpC β-lactamase with impermeability in E. cloacae clinical isolates implicated in reduced carbapenem susceptibility. Although carbapenem-resistant E. cloacae isolates were isolated in a few patients in our study, the clinical outcomes were grave. Therefore, the patients colonized or infected by carbapenem-resistant E. cloacae isolates should gain attention of antibiotic therapy.

  20. Negative correlation between phospholipase and esterase activity produced by Fusarium isolates

    PubMed Central

    Ishida, K.; Alviano, D.S.; Silva, B.G.; Guerra, C.R.; Costa, A.S.; Nucci, M.; Alviano, C.S.; Rozental, S.

    2012-01-01

    Fusarium species have emerged as one of the more outstanding groups of clinically important filamentous fungi, causing localized and life-threatening invasive infections with high morbidity and mortality. The ability to produce different types of hydrolytic enzymes is thought to be an important virulence mechanism of fungal pathogens and could be associated with the environment of the microorganism. Here, we have measured the production of two distinct lipolytic enzymes, phospholipase and esterase, by sixteen Fusarium isolates recovered from the hospital environment, immunocompromised patients' blood cultures, foot interdigital space scrapings from immunocompromised patients, and foot interdigital space scrapings from immunocompetent patients (4 isolates each). Fourteen of these 16 isolates were identified as Fusarium solani species complex (FSSC) and two were identified as F. oxysporum species complex (FOSC). Some relevant genus characteristics were visualized by light and electron microscopy such as curved and multicelled macroconidia with 3 or 4 septa, microconidia, phialides, and abundant chlamydospores. All Fusarium isolates were able to produce esterase and phospholipase under the experimental conditions. However, a negative correlation was observed between these two enzymes, indicating that a Fusarium isolate with high phospholipase activity has low esterase activity and vice versa. In addition, Fusarium isolated from clinical material produced more phospholipases, while environmental strains produced more esterases. These observations may be correlated with the different types of substrates that these fungi need to degrade during their nutrition processes. PMID:22415116

  1. Beta-Lactamase Producing Escherichia coli Isolates in Imported and Locally Produced Chicken Meat from Ghana

    PubMed Central

    Rasmussen, Mette Marie; Opintan, Japheth A.; Frimodt-Møller, Niels; Styrishave, Bjarne

    2015-01-01

    The use of antibiotics in food animals is of public health concern, because resistant zoonotic pathogens can be transmitted to humans. Furthermore, global trade with food may rapidly spread multi-resistant pathogens between countries and even continents. The purpose of the study was to investigate whether imported chicken meat and meat from locally reared chicken are potential sources for human exposure to multi resistant Escherichia coli isolates. 188 samples from imported and locally produced chicken meat were sampled and analyzed. 153 bacteria isolates were successfully cultured and identified as E. coli using MALDI-ToF. Of these 109 isolates were from meat whereas the remaining 44 were isolated from the cloaca of locally reared live chickens. Antimicrobial susceptibility test was done on the identified E. coli isolates. Additionally, beta-lactamases production (ESBL and/or AmpC) were phenotypically confirmed on all isolates showing resistance to cefpodoxime. Beta-lactamase producing (BLP) E. coli meat isolates were further genotyped. Antimicrobial resistance to four antibiotic markers with highest resistance was detected more frequently in isolates from local chickens compared to imported chickens (tetracycline 88.9% vs. 57.5%, sulphonamide 75.0% vs. 46.6%, ampicillin 69.4% vs. 61.6% and trimethoprim 66.7% vs. 38.4%). Beta-lactamase production was found in 29 E. coli meat isolates, with 56.9% of them being multiple drug resistant (≥ 3). The predominant phylogroup identified was B1 followed by A and D, with similar distribution among the isolates from meat of locally reared chickens and imported chickens. Beta-lactamase producing genotype blaCTX-M-15 (50%; 10/20) was the most frequently drug resistant gene detected. More BLP E. coli isolates were found in imported chicken meat compared to locally reared chickens, demonstrating that these isolates may be spreading through food trade. In conclusion, both imported and locally produced chicken meats are potential

  2. Beta-Lactamase Producing Escherichia coli Isolates in Imported and Locally Produced Chicken Meat from Ghana.

    PubMed

    Rasmussen, Mette Marie; Opintan, Japheth A; Frimodt-Møller, Niels; Styrishave, Bjarne

    2015-01-01

    The use of antibiotics in food animals is of public health concern, because resistant zoonotic pathogens can be transmitted to humans. Furthermore, global trade with food may rapidly spread multi-resistant pathogens between countries and even continents. The purpose of the study was to investigate whether imported chicken meat and meat from locally reared chicken are potential sources for human exposure to multi resistant Escherichia coli isolates. 188 samples from imported and locally produced chicken meat were sampled and analyzed. 153 bacteria isolates were successfully cultured and identified as E. coli using MALDI-ToF. Of these 109 isolates were from meat whereas the remaining 44 were isolated from the cloaca of locally reared live chickens. Antimicrobial susceptibility test was done on the identified E. coli isolates. Additionally, beta-lactamases production (ESBL and/or AmpC) were phenotypically confirmed on all isolates showing resistance to cefpodoxime. Beta-lactamase producing (BLP) E. coli meat isolates were further genotyped. Antimicrobial resistance to four antibiotic markers with highest resistance was detected more frequently in isolates from local chickens compared to imported chickens (tetracycline 88.9% vs. 57.5%, sulphonamide 75.0% vs. 46.6%, ampicillin 69.4% vs. 61.6% and trimethoprim 66.7% vs. 38.4%). Beta-lactamase production was found in 29 E. coli meat isolates, with 56.9% of them being multiple drug resistant (≥ 3). The predominant phylogroup identified was B1 followed by A and D, with similar distribution among the isolates from meat of locally reared chickens and imported chickens. Beta-lactamase producing genotype blaCTX-M-15 (50%; 10/20) was the most frequently drug resistant gene detected. More BLP E. coli isolates were found in imported chicken meat compared to locally reared chickens, demonstrating that these isolates may be spreading through food trade. In conclusion, both imported and locally produced chicken meats are potential

  3. Volatiles produced by microorganisms isolated from refrigerated chicken at spoilage.

    PubMed Central

    Freeman, L R; Silverman, G J; Angelini, P; Merritt, C; Esselen, W B

    1976-01-01

    Volatile components present at spoilage of refrigerated chicken breasts were identified using high-vacuum-low-temperature distillation techniques followed by analysis with combined temperature-programmed gas chromatography and mass spectrometry. A comparison was made of the compounds detected from both irradiated and non-irradiated muscle stored at 2 and 10 degrees C under both aerobic and anaerobic conditions. Isolates were randomly selected from the spoiled poultry, identified, and evaluated for their ability to produce volatile spoilage noted when grown on radiation-sterilized chicken. Several isolates that produced off-odors on sterile chicken breasts were examined. Twenty-two compounds were associated with spoilage. Some of the compounds found on both irradiated and unirradiated samples were considered to play only a minor role in the spoilage aroma or were present in low concentrations, since the aroma of spoiled irradiated chicken lacked the harsh odor notes typical of spoiled unirradiated chicken. Fifteen of the 22 compounds were considered to be unique to unirradiated, aerobically spoiled samples. Nine of these compounds, hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfide, methyl acetate, ethyl acetate, heptadiene, methanol, and ethanol, were found on chicken spoiled at both 2 and 10 degrees C. xylene, benzaldehyde, and 2,3-dithiahexane were detected only in samples stored at 2 degrees C and methyl thiolacetate, 2-butanone, and ethyl propionate were associated with 10 degrees C spoilage. Fifty-eight isolates randomly selected from fresh, radiation-pasteurized, and unirradiated spoiled poultry were classified taxonomically, and 10 of them, which produced spoilage odors on sterilized chicken breasts, were selected for subsequent analysis of their volatiles. Isolates identified as Pseudomonas putrefaciens and Pseudomonas species that were members of groups I and II of Shewan's classification, as well as Flavobacterium and oxidative

  4. Detection and spread of oxa-48-producing Klebsiella oxytoca isolates in Istanbul, Turkey.

    PubMed

    Nazik, Hasan; Aydin, Selda; Albayrak, Rüveyda; Bilgi, Esma A; Yildiz, Ismail; Kuvat, Nuray; Kelesoglu, Fatih M; Kelesoglu, Fatih M; Pakaştiçali, Nagehan; Yilmaz, Fadime; Ongen, Betigül

    2014-01-01

    Five OXA-48 producing Klebsiella oxytoca strains isolated in April-July 2010 were analyzed. Antibiotic susceptibility tests were performed using disc diffusion method and VITEK 2 system. Carbapenemase activity was investigated using the Modified Hodge test. Beta-lactamase genes were detected by PCR and blaOXA-48 was sequenced. Genetic relatedness between K. oxytoca isolates was investigated by pulse-field gel electrophoresis (PFGE). Carbapenemase activity was detected in 5 isolates by Modified Hodge test. Although all strains were resistant to ertapenem and imipenem, only one strain was also resistant to meropenem. BlaOXA-48 in 4 isolates harbored 2 or 3 other ESBL types, namely, blaTEM, blaSHV, blaCTX-M, or blaVEB. PFGE revealed 3 different pulso-types among the K. oxytoca isolates. The presence of OXA-48 carbapenemase in other species of clinical isolates should also be considered.

  5. New method for isolating antibiotic-producing fungi.

    PubMed

    Kawaguchi, Mio; Nonaka, Kenichi; Masuma, Rokuro; Tomoda, Hiroshi

    2013-01-01

    A convenient and efficient method was established for isolating antifungal antibiotic-producing fungi from soil samples. In this method, soil samples were diluted and directly plated in agar medium by the standard fungi-isolating method, and the plates were cultured at 27 °C for 2-3 days to permit the growth of fungal colonies. Then, the suspension of pathogenic Candida albicans in saline (40 μl, 5-10 × 10⁵ CFU ml⁻¹) was overlaid by spraying on the plates under controlled conditions in the safety cabinet. After 1-day incubation, fungal colonies showing an antagonistic effect with the inhibition zone against sprayed C. albicans were selected. Among 151 isolates, 26 strains were found to reproduce anti-C. albicans activity in liquid medium, yielding a higher selection rate (17.2%) than that (3.1%) by the traditional method. This new method can be applied for isolation of microorganisms (fungi and actinomycetes) that produce antibiotics active against pathogenic microorganisms.

  6. Isolation of fucosyltransferase-producing bacteria from marine environments.

    PubMed

    Kajiwara, Hitomi; Toda, Munetoyo; Mine, Toshiki; Nakada, Hiroshi; Yamamoto, Takeshi

    2012-01-01

    Fucose-containing oligosaccharides on the cell surface of some pathogenic bacteria are thought to be important for host-microbe interactions and to play a major role in the pathogenicity of bacterial pathogens. Here, we screened marine bacteria for glycosyltransferases using two methods: a one-pot glycosyltransferase assay method and a lectin-staining method. Using this approach, we isolated marine bacteria with fucosyltransferase activity. There have been no previous reports of marine bacteria producing fucosyltransferase. This paper thus represents the first report of fucosyltransferase-producing marine bacteria.

  7. Characterization of Micrococcaceae Isolated from Clinical Sources

    PubMed Central

    Person, Donald A.; Yu, Pauline K. W.; Washington, John A.

    1969-01-01

    The characterization of 556 Micrococcaceae isolates from various clinical sources has been presented. The incidence of coagulase-negative mannitol-positive staphylococci was 3.2% and that of coagulase-positive mannitol-negative staphylococci was 1.6%. There appears to be insufficient justification for the routine reporting of staphylococcal variants from a general bacteriology laboratory, and biotyping should be reserved for special circumstances. PMID:5803634

  8. Extracellular enzymes produced by microorganisms isolated from maritime Antarctica.

    PubMed

    Loperena, Lyliam; Soria, Verónica; Varela, Hermosinda; Lupo, Sandra; Bergalli, Alejandro; Guigou, Mairan; Pellegrino, Andrés; Bernardo, Angela; Calviño, Ana; Rivas, Federico; Batista, Silvia

    2012-05-01

    Antarctic environments can sustain a great diversity of well-adapted microorganisms known as psychrophiles or psychrotrophs. The potential of these microorganisms as a resource of enzymes able to maintain their activity and stability at low temperature for technological applications has stimulated interest in exploration and isolation of microbes from this extreme environment. Enzymes produced by these organisms have a considerable potential for technological applications because they are known to have higher enzymatic activities at lower temperatures than their mesophilic and thermophilic counterparts. A total of 518 Antarctic microorganisms, were isolated during Antarctic expeditions organized by the Instituto Antártico Uruguayo. Samples of particules suspended in air, ice, sea and freshwater, soil, sediment, bird and marine animal faeces, dead animals, algae, plants, rocks and microbial mats were collected from different sites in maritime Antarctica. We report enzymatic activities present in 161 microorganisms (120 bacteria, 31 yeasts and 10 filamentous fungi) isolated from these locations. Enzymatic performance was evaluated at 4 and 20°C. Most of yeasts and bacteria grew better at 20°C than at 4°C, however the opposite was observed with the fungi. Amylase, lipase and protease activities were frequently found in bacterial strains. Yeasts and fungal isolates typically exhibited lipase, celullase and gelatinase activities. Bacterial isolates with highest enzymatic activities were identified by 16S rDNA sequence analysis as Pseudomonas spp., Psychrobacter sp., Arthrobacter spp., Bacillus sp. and Carnobacterium sp. Yeasts and fungal strains, with multiple enzymatic activities, belonged to Cryptococcus victoriae, Trichosporon pullulans and Geomyces pannorum.

  9. Brasilinolide A, a new macrolide antibiotic produced by Nocardia brasiliensis: producing strain, isolation and biological activity.

    PubMed

    Tanaka, Y; Komaki, H; Yazawa, K; Mikami, Y; Nemoto, A; Tojyo, T; Kadowaki, K; Shigemori, H; Kobayashi, J

    1997-12-01

    A new 32-membered macrolide antibiotic, brasilinolide A was isolated from the fermentation broth of Nocardia sp. IFM 0406. The producer was identified as Nocardia brasiliensis. The antibiotic was only active against Aspergillus niger, but not active against other fungi including yeasts as well as other filamentous like fungi and bacteria. Brasilinolide A exerted an immunosuppressive activity in the assay system of a mixed lymphocyte reaction (MLR).

  10. Clinically isolated neurosarcoidosis: a recommended diagnostic path.

    PubMed

    Wegener, Susanne; Linnebank, Michael; Martin, Roland; Valavanis, Anton; Weller, Michael

    2015-01-01

    The involvement of the central nervous system in sarcoidosis can manifest with a variety of neurological symptoms, most of them nonspecific. We identified 13 patients with neurosarcoidosis diagnosed at our clinic. Six of 13 patients presented with clinically isolated neurosarcoidosis (CINS) without signs or symptoms of systemic disease. CINS patients were not different with respect to age, as well as imaging and spinal fluid findings, or disease course. However, we found spinal cord involvement in neurosarcoidosis patients much more common than previously described (in 8 out of 13 patients). Spinal cord affection was associated with older age at diagnosis and a less favorable response to therapy. Based on our findings, we propose a diagnostic path for neurosarcoidosis, including spinal magnetic resonance imaging (MRI) as a mandatory and early step during diagnostic workup.

  11. Clinically Isolated Syndromes: Clinical Characteristics, Differential Diagnosis, and Management

    PubMed Central

    EFENDİ, Hüsnü

    2015-01-01

    Clinically isolated syndrome (CIS) is a term that describes the first clinical onset of potential multiple sclerosis (MS). The term CIS is typically applied to young adults with episodes of acute or subacute onset, which reaches a peak quite rapidly within 2–3 weeks. In 85% of young adults who develop MS, onset occurs with an acute, CIS of the optic nerves, brainstem, or spinal cord. When clinically silent brain lesions are seen on MRI, the likelihood of developing MS is high. Because no single clinical feature or diagnostic test is sufficient for the diagnosis of CIS, diagnostic criteria have included a combination of both clinical and paraclinical studies. Diagnostic criteria from the International Panel of McDonald and colleagues incorporate MRI evidence of dissemination in time and space to allow a diagnosis of definite MS in patients with CIS. As CIS is typically the earliest clinical expression of MS, research on patients with CIS may provide new insights into early pathological changes and pathogenetic mechanisms that might affect the course of the disorder. With recent improvements in diagnosis and the advent of disease-modifying treatments for MS, there has been growing interest and research in patients with CIS.

  12. First report of VIM-2 metallo-β-lactamases producing Pseudomonas aeruginosa isolates in Morocco.

    PubMed

    Maroui, Itto; Barguigua, Abouddihaj; Aboulkacem, Asmae; Ouarrak, Khadija; Sbiti, Mohammed; Louzi, Housssain; Timinouni, Mohammed; Belhaj, Abdelhaq

    2016-03-01

    The emergence and the rapid spread of Pseudomonas aeruginosa carrying carbapenemases represent a serious threat to public health due to their delicate therapy. This work was performed to establish the resistance profile and to detect carbapenemases producing in 123 P. aeruginosa isolates. Among these 55 are environmental isolates and 68 are from the two major hospitals of Meknes-Tafilalet region in Morocco. All strains were tested against 14 antipseudomonal drugs by disc diffusion method. On carbapenem resistant strains minimum inhibitory concentrations of imipenem were determined by the E-test method. The modified Hodge test and EDTA tests were used for the detection of carbapenemases and metallo-β-lactamases (MBLs), respectively. PCR and DNA sequencing were conducted to detect carbapenemase-encoding genes and the enzyme types. 12% of isolates was susceptible to all antibiotics tested and Carbapenem resistance was observed in 33 P. aeruginosa isolates, 33.3% of them were multi-drug resistant. Among carbapenem resistant strains only two (6.1%) were positive for carbapenemases and also for MBLs. In addition to their resistance to almost all β-lactams tested, the MBLs producing strains were resistant to aminoglycosides. Molecular biology techniques confirmed the phenotypic results obtained for the two strains carbapenemase producers and demonstrated that each one of them carried blaVIM-2. The present study reports the first isolation of blaVIM genes in clinical isolates of P. aeruginosa in Morocco. Such isolates represent a serious emerging threat requiring strict hygiene measures to better control their spread.

  13. Contribution of β-lactamases and porin proteins OmpK35 and OmpK36 to carbapenem resistance in clinical isolates of KPC-2-producing Klebsiella pneumoniae.

    PubMed

    Zhang, Ying; Jiang, Xiaofei; Wang, Yanyan; Li, Gang; Tian, Yueru; Liu, Hong; Ai, Fuqi; Ma, Yiming; Wang, Bei; Ruan, Feiyi; Rajakumar, Kumar

    2014-01-01

    Fifty-seven carbapenem-resistant Klebsiella pneumoniae isolates belonging to ST11 (50 isolates), ST423 (5 isolates), and two other sequence types were studied. All were positive for blaKPC-2, blaTEM-1, and blaCTX-M-14. SDS-PAGE analysis of six representative isolates demonstrated varied porin expression. Nevertheless, when blaKPC-2 was deleted, carbapenem resistance was markedly reduced. Additionally, SHV-12, DHA-1, and/or VIM-1 appeared to contribute to accessory carbapenemase activity. In contrast, OmpK35 and/or OmpK36 deficiency seemed to serve only as a minor cooperative factor.

  14. MALDI-TOF MS as a Tool To Detect a Nosocomial Outbreak of Extended-Spectrum-β-Lactamase- and ArmA Methyltransferase-Producing Enterobacter cloacae Clinical Isolates in Algeria

    PubMed Central

    Khennouchi, Nour Chems el Houda; Loucif, Lotfi; Boutefnouchet, Nafissa; Allag, Hamoudi

    2015-01-01

    Enterobacter cloacae is among the most important pathogens responsible for nosocomial infections and outbreaks. In this study, 77 Enterobacter isolates were collected: 27 isolates from Algerian hospitals (in Constantine, Annaba, and Skikda) and 50 isolates from Marseille, France. All strains were identified by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). Antibiotic susceptibility testing was performed by the disk diffusion method. PCR was used to detect extended-spectrum-beta-lactamase (ESBL)-encoding, fluoroquinolone resistance-encoding, and aminoglycoside-modifying enzyme (AME) genes. Epidemiological typing was performed using MALDI-TOF MS with data mining approaches, along with multilocus sequence typing (MLST). Sixty-eight isolates (27 from Algeria, 41 from Marseille) were identified by MALDI-TOF MS as E. cloacae. Resistance to antibiotics in the Algerian isolates was significantly higher than that in the strains from Marseille, especially for beta-lactams and aminoglycosides. Eighteen of the 27 Algerian isolates and 11 of the 41 Marseille isolates possessed at least one ESBL-encoding gene: blaCTX-M and/or blaTEM. AME genes were detected in 20 of the 27 Algerian isolates and 8 of the 41 Marseille isolates [ant(2″)-Ia, aac(6′)-Ib-cr, aadA1, aadA2, and armA]. Conjugation experiments showed that armA was carried on a transferable plasmid. MALDI-TOF typing showed three separate clusters according to the geographical distribution and species level. An MLST-based phylogenetic tree showed a clade of 14 E. cloacae isolates from a urology unit clustering together in the MALDI-TOF dendrogram, suggesting the occurrence of an outbreak in this unit. In conclusion, the ability of MALDI-TOF to biotype strains was confirmed, and surveillance measures should be implemented, especially for Algerian patients hospitalized in France. PMID:26239991

  15. MALDI-TOF MS as a Tool To Detect a Nosocomial Outbreak of Extended-Spectrum-β-Lactamase- and ArmA Methyltransferase-Producing Enterobacter cloacae Clinical Isolates in Algeria.

    PubMed

    Khennouchi, Nour Chems el Houda; Loucif, Lotfi; Boutefnouchet, Nafissa; Allag, Hamoudi; Rolain, Jean-Marc

    2015-10-01

    Enterobacter cloacae is among the most important pathogens responsible for nosocomial infections and outbreaks. In this study, 77 Enterobacter isolates were collected: 27 isolates from Algerian hospitals (in Constantine, Annaba, and Skikda) and 50 isolates from Marseille, France. All strains were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Antibiotic susceptibility testing was performed by the disk diffusion method. PCR was used to detect extended-spectrum-beta-lactamase (ESBL)-encoding, fluoroquinolone resistance-encoding, and aminoglycoside-modifying enzyme (AME) genes. Epidemiological typing was performed using MALDI-TOF MS with data mining approaches, along with multilocus sequence typing (MLST). Sixty-eight isolates (27 from Algeria, 41 from Marseille) were identified by MALDI-TOF MS as E. cloacae. Resistance to antibiotics in the Algerian isolates was significantly higher than that in the strains from Marseille, especially for beta-lactams and aminoglycosides. Eighteen of the 27 Algerian isolates and 11 of the 41 Marseille isolates possessed at least one ESBL-encoding gene: blaCTX-M and/or blaTEM. AME genes were detected in 20 of the 27 Algerian isolates and 8 of the 41 Marseille isolates [ant(2″)-Ia, aac(6')-Ib-cr, aadA1, aadA2, and armA]. Conjugation experiments showed that armA was carried on a transferable plasmid. MALDI-TOF typing showed three separate clusters according to the geographical distribution and species level. An MLST-based phylogenetic tree showed a clade of 14 E. cloacae isolates from a urology unit clustering together in the MALDI-TOF dendrogram, suggesting the occurrence of an outbreak in this unit. In conclusion, the ability of MALDI-TOF to biotype strains was confirmed, and surveillance measures should be implemented, especially for Algerian patients hospitalized in France.

  16. Identification and Pathogenic Potential of Clinical Bacillus and Paenibacillus Isolates.

    PubMed

    Celandroni, Francesco; Salvetti, Sara; Gueye, Sokhna Aissatou; Mazzantini, Diletta; Lupetti, Antonella; Senesi, Sonia; Ghelardi, Emilia

    2016-01-01

    The soil-related Bacillus and Paenibacillus species have increasingly been implicated in various human diseases. Nevertheless, their identification still poses problems in the clinical microbiology laboratory and, with the exception of Bacillus anthracis and Bacillus cereus, little is known on their pathogenicity for humans. In this study, we evaluated the use of matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS) in the identification of clinical isolates of these genera and conducted genotypic and phenotypic analyses to highlight specific virulence properties. Seventy-five clinical isolates were subjected to biochemical and MALDI-TOF MS identification. 16S rDNA sequencing and supplemental tests were used to solve any discrepancies or failures in the identification results. MALDI-TOF MS significantly outperformed classical biochemical testing for correct species identification and no misidentification was obtained. One third of the collected strains belonged to the B. cereus species, but also Bacillus pumilus and Bacillus subtilis were isolated at high rate. Antimicrobial susceptibility testing showed that all the B. cereus, B. licheniformis, B. simplex, B. mycoides, Paenibacillus glucanolyticus and Paenibacillus lautus isolates are resistant to penicillin. The evaluation of toxin/enzyme secretion, toxin-encoding genes, motility, and biofilm formation revealed that B. cereus displays the highest virulence potential. However, although generally considered nonpathogenic, most of the other species were shown to swim, swarm, produce biofilms, and secrete proteases that can have a role in bacterial virulence. In conclusion, MALDI-TOF MS appears useful for fast and accurate identification of Bacillus and Paenibacillus strains whose virulence properties make them of increasing clinical relevance.

  17. Identification and Pathogenic Potential of Clinical Bacillus and Paenibacillus Isolates

    PubMed Central

    Celandroni, Francesco; Salvetti, Sara; Gueye, Sokhna Aissatou; Mazzantini, Diletta; Lupetti, Antonella; Senesi, Sonia; Ghelardi, Emilia

    2016-01-01

    The soil-related Bacillus and Paenibacillus species have increasingly been implicated in various human diseases. Nevertheless, their identification still poses problems in the clinical microbiology laboratory and, with the exception of Bacillus anthracis and Bacillus cereus, little is known on their pathogenicity for humans. In this study, we evaluated the use of matrix-assisted laser desorption—ionization time of flight mass spectrometry (MALDI-TOF MS) in the identification of clinical isolates of these genera and conducted genotypic and phenotypic analyses to highlight specific virulence properties. Seventy-five clinical isolates were subjected to biochemical and MALDI-TOF MS identification. 16S rDNA sequencing and supplemental tests were used to solve any discrepancies or failures in the identification results. MALDI-TOF MS significantly outperformed classical biochemical testing for correct species identification and no misidentification was obtained. One third of the collected strains belonged to the B. cereus species, but also Bacillus pumilus and Bacillus subtilis were isolated at high rate. Antimicrobial susceptibility testing showed that all the B. cereus, B. licheniformis, B. simplex, B. mycoides, Paenibacillus glucanolyticus and Paenibacillus lautus isolates are resistant to penicillin. The evaluation of toxin/enzyme secretion, toxin-encoding genes, motility, and biofilm formation revealed that B. cereus displays the highest virulence potential. However, although generally considered nonpathogenic, most of the other species were shown to swim, swarm, produce biofilms, and secrete proteases that can have a role in bacterial virulence. In conclusion, MALDI-TOF MS appears useful for fast and accurate identification of Bacillus and Paenibacillus strains whose virulence properties make them of increasing clinical relevance. PMID:27031639

  18. Isolation, screening and characterization of bacteriocin-producing lactic acid bacteria isolated from traditional fermented food.

    PubMed

    El-Shafei, H A; Abd-El-Sabour, H; Ibrahim, N; Mostafa, Y A

    2000-03-01

    100 lactic acid bacterial strains isolated from traditional fermented foods (yoghurt, milk cream, sour dough and milk) were screened for bacteriocin production. Twenty six strains producing a nisin-like bacteriocin were selected. Most of these isolates gave only a narrow inhibitory spectrum, although one showed a broad inhibitory spectrum against the indicator strains tested, this strain was determined as Lactococcus lactis. The influence of several parameters on the fermentative production of nisin by Lactococcus lactis was studied. Production of nisin was optimal at 30 degrees C and in the pH range 5.5-6.3. The effect of different sulphur and nitrogen sources on Lactococcus lactis growth and nisin production was studied. Magnesium sulfate and manganese sulfate were found to be the best sulphur sources while triammonium citrate was the best inorganic nitrogen source and meat extract, peptone and yeast extract were the best organic nitrogen source for nisin production.

  19. Detection of biofilm production and antibiotic resistance pattern in clinical isolates from indwelling medical devices.

    PubMed

    Mishra, Shyam Kumar; Basukala, Prashant; Basukala, Om; Parajuli, Keshab; Pokhrel, Bharat Mani; Rijal, Basista Prasad

    2015-01-01

    Microbial biofilms pose great threat for patients requiring indwelling medical devices (IMDs) as it is difficult to remove them. It is, therefore, crucial to follow an appropriate method for the detection of biofilms. The present study focuses on detection of biofilm formation among the isolates from IMDs. We also aimed to explore the antibiogram of biofilm producers. This prospective analysis included 65 prosthetic samples. After isolation and identification of bacteria following standard methodology, antibiogram of the isolates were produced following Kirby-Bauer disc diffusion method. Detection of biofilms was done by tube adherence (TA), Congo red agar and tissue culture plate (TCP) methods. Out of 67 clinical isolates from IMDs, TCP detected 31 (46.3 %) biofilm producers and 36 (53.7 %) biofilm non-producers. Klebsiella pneumoniae, Pseudomonas aeruginosa and Burkholderia cepacia complex were found to be the most frequent biofilm producers. The TA method correlated well with the TCP method for biofilm detection. Higher antibiotic resistance was observed in biofilm producers than in biofilm non-producers. The most effective antibiotics for biofilm producing Gram-positive isolates were Vancomycin and Tigecycline, and that for biofilm producing Gram-negative isolates were Polymyxin-B, Colistin Sulphate and Tigecycline. Nearly 46 % of the isolates were found to be biofilm producers. The antibiotic susceptibility pattern in the present study showed Amoxicillin to be an ineffective drug for isolates from the IMDs. For the detection of biofilm production, TA method can be an economical and effective alternative to TCP method.

  20. Metallo-β-Lactamase-Producing Pseudomonas spp. in Korea: High Prevalence of Isolates with VIM-2 Type and Emergence of Isolates with IMP-1 Type

    PubMed Central

    Lee, Kyungwon; Park, Ae Ja; Kim, Moon Yeun; Lee, Hee Joo; Cho, Ji-Hyun; Kang, Jung Oak; Yong, Dongeun

    2009-01-01

    Purpose Two Korean nationwide studies showed that metallo-β-lactamases (MBLs)-producing-Pseudomonas spp. are not rare. The aim of this study was to assess the trends of MBL-producing isolates among imipenem-resistant isolates of Pseudomonas spp. Materials and Methods Imipenem-resistant clinical isolates were collected from 23 hospitals and one commercial laboratory participating in the KONSAR program in 2005. Polymerase chain reaction (PCR) was used to detect MBL genes. Results Alleles of MBL genes were detected in 10.8% of 415 Pseudomonas aeruginosa and 66.7% of 12 P. putida isolates from 18 of 24 hospitals/laboratory. Among the 14 IMP-1-like and 39 VIM-2-like MBLs, emergence of IMP-6 was detected for the first time. Conclusion Prevalence of MBL-producing P. aeruginosa has not significantly increased, but IMP-6 emerged in P. aeruginosa. PMID:19568593

  1. Isolation and plasmid characterization of carbapenemase (IMP-4) producing Salmonella enterica Typhimurium from cats

    PubMed Central

    Abraham, Sam; O’Dea, Mark; Trott, Darren J.; Abraham, Rebecca J.; Hughes, David; Pang, Stanley; McKew, Genevieve; Cheong, Elaine Y. L.; Merlino, John; Saputra, Sugiyono; Malik, Richard; Gottlieb, Thomas

    2016-01-01

    Carbapenem-resistant Enterobacteriaceae (CRE) are a pressing public health issue due to limited therapeutic options to treat such infections. CREs have been predominantly isolated from humans and environmental samples and they are rarely reported among companion animals. In this study we report on the isolation and plasmid characterization of carbapenemase (IMP-4) producing Salmonella enterica Typhimurium from a companion animal. Carbapenemase-producing S. enterica Typhimurium carrying blaIMP-4 was identified from a systemically unwell (index) cat and three additional cats at an animal shelter. All isolates were identical and belonged to ST19. Genome sequencing revealed the acquisition of a multidrug-resistant IncHI2 plasmid (pIMP4-SEM1) that encoded resistance to nine antimicrobial classes including carbapenems and carried the blaIMP-4-qacG-aacA4-catB3 cassette array. The plasmid also encoded resistance to arsenic (MIC-150 mM). Comparative analysis revealed that the plasmid pIMP4-SEM1 showed greatest similarity to two blaIMP-8 carrying IncHI2 plasmids from Enterobacter spp. isolated from humans in China. This is the first report of CRE carrying a blaIMP-4 gene causing a clinical infection in a companion animal, with presumed nosocomial spread. This study illustrates the broader community risk entailed in escalating CRE transmission within a zoonotic species such as Salmonella, and in a cycle that encompasses humans, animals and the environment. PMID:27767038

  2. Distribution and antimicrobial susceptibility profile of extended-spectrum β-lactamase-producing Proteus mirabilis strains recently isolated in Japan.

    PubMed

    Kanayama, Akiko; Kobayashi, Intetsu; Shibuya, Kazutoshi

    2015-02-01

    Here we report on the prevalence of extended-spectrum β-lactamase (ESBL)-producing Proteus mirabilis from a nationwide antimicrobial resistance survey in different geographical regions of Japan. A total of 799 P. mirabilis isolates recovered between July 2009 and June 2010 from 314 healthcare facilities were characterised according to ESBL production, source, location and antimicrobial susceptibility pattern. ESBL production was found in 364 (45.6%) of the isolates, among which 354 (97.3%) produced CTX-M-2 group β-lactamases. Of the 349 ESBL-producing isolates in which the inpatient or outpatient status of the source was known, 324 (92.8%) were from inpatients and 25 (7.2%) were from outpatients (P<0.05). Results of pulsed-field gel electrophoresis (PFGE) analysis performed on 66 of the ESBL-producers generated a distribution of PFGE patterns into 21 groups. Genetic relatedness was seen among isolates within a region, which is consistent with horizontal transmission. With respect to the frequency of ESBL-producers by specimen source, 12/14 (85.7%) central venous catheter specimens yielded ESBL-producing P. mirabilis compared with 159/405 (39.3%), 119/209 (56.9%), 42/77 (54.5%) and 20/49 (40.8%), respectively, for isolates from urine, sputum, decubitus ulcer and wound specimens. Among the ESBL-producers, non-susceptibility to ciprofloxacin was found in 74.2% of the ESBL-producing isolates compared with 17.7% of the ESBL-non-producing isolates. These results show that approximately one-half of the P. mirabilis isolates from clinical specimens in Japan are ESBL-producers and that the potential for concomitant fluoroquinolone resistance must also be considered.

  3. Isolation of Extended Spectrum β-lactamase (ESBL) Producing Bacteria from Urban Surface Waters in Malaysia

    PubMed Central

    Tissera, Shehani; Lee, Sui Mae

    2013-01-01

    Background: This was a preliminary study to test for the presence of multiple antibiotic-resistant extended spectrum β-lactamase (ESBL) producing bacteria in Malaysian urban surface waters. Although the literature review revealed several published papers on clinical ESBL isolates in Malaysia, none were found on ESBL isolates obtained from local surface waters Methods: Isolated bacterial species were tested for resistance to cefotaxime, amoxicillin/clavulanate and aztreonam, and susceptibility to imipenem and meropenem using antibiotic susceptibility testing (AST) by disc diffusion. This served as a screening step to detect bacteria that could be potential ESBL species. 16S ribose ribonucleic acid (rRNA) polymerase chain reaction (PCR) testing with two clusters of bla (β-lactamase) gene primers was used to test for the bla genes CTX-M (Groups 1, 2, 9), OXA-1, SHV and TEM. Results: A total of 19 isolates were found, possessing at least one of the bla genes tested for. There was a relatively high occurrence of CTX-M genes (84.2%) among these, followed by TEM genes (47.4%). The isolates were identified as Enterobacteriaceae (89.5%), predominantly Escherichia coli and Klebsiella pneumoniae. Conclusion: There appears to be a high occurrence of ESBL-bacteria in local surface waters, among these being opportunistic pathogens. The persistence and spread of these species in the environment poses a threat to exposed human populations. PMID:23966820

  4. 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.

  5. Analysis of penicillinase-producing Neisseria gonorrhoeae isolates in Madrid (Spain) from 1983-85.

    PubMed Central

    Fenoll, A.; Berrón, S.; Vázquez, J. A.

    1987-01-01

    Between April 1983 and December 1985, 576 strains of Neisseria gonorrhoeae were isolated in our laboratory from patients attending Sexually Transmitted Diseases (STD) clinics. Of these, 61 (10.6%) were penicillinase-producing. Studies on these strains by plasmid analysis, auxotyping and serogrouping showed that the predominant type strains harboured the Asian resistance plasmid, were prototrophic, and were of serogroup W II/W III. About half of the strains, both of the African and Asian type, harboured the transfer plasmid. Strains of serogroup W II/W III were less sensitive to tetracycline and cefoxitin than serogroup W I strains. Images Fig. 2 PMID:2960555

  6. Clonal spread and interspecies transmission of clinically relevant ESBL-producing Escherichia coli of ST410--another successful pandemic clone?

    PubMed

    Schaufler, Katharina; Semmler, Torsten; Wieler, Lothar H; Wöhrmann, Michael; Baddam, Ramani; Ahmed, Niyaz; Müller, Kerstin; Kola, Axel; Fruth, Angelika; Ewers, Christa; Guenther, Sebastian

    2016-01-01

    Clinically relevant extended-spectrum beta-lactamase (ESBL)-producing multi-resistant Escherichia coli have been on the rise for years. Initially restricted to mostly a clinical context, recent findings prove their prevalence in extraclinical settings independent of the original occurrence of antimicrobial resistance in the environment. To get further insights into the complex ecology of potentially clinically relevant ESBL-producing E. coli, 24 isolates from wild birds in Berlin, Germany, and 40 ESBL-producing human clinical E. coli isolates were comparatively analyzed. Isolates of ST410 occurred in both sample groups (six). In addition, three ESBL-producing E. coli isolates of ST410 from environmental dog feces and one clinical dog isolate were included. All 10 isolates were clonally analyzed showing almost identical macrorestriction patterns. They were chosen for whole-genome sequencing revealing that the whole-genome content of these 10 E. coli isolates showed a very high genetic similarity, differing by low numbers of single nucleotide polymorphisms only. This study gives initial evidence for a recent interspecies transmission of a new successful clone of ST410 E. coli between wildlife, humans, companion animals and the environment. The results underline the zoonotic potential of clinically relevant multi-resistant bacteria found in the environment as well as the mandatory nature of the 'One Health' approach.

  7. Assessment of pheromone response in biofilm forming clinical isolates of high level gentamicin resistant Enterococcus faecalis.

    PubMed

    Jayanthi, S; Ananthasubramanian, M; Appalaraju, B

    2008-01-01

    Twenty five clinical isolates of high level gentamicin resistant Enterococcus faecalis were tested for their biofilm formation and pheromone responsiveness. The biofilm assay was carried out using microtiter plate method. Two isolates out of the 25 (8%) were high biofilm formers and 19 (76%) and four (16%) isolates were moderate and weak biofilm formers respectively. All the isolates responded to pheromones of E. faecalis FA2-2 strain. On addition of pheromone producing E. faecalis FA2-2 strain to these isolates, seven of 19 (37%) moderate biofilm formers developed into high biofilm formers. Similarly one of the 4 (25%) weak biofilm formers developed into high level biofilm former. Twelve (48%) of the 25 isolates were transconjugated by cross streak method using gentamicin as selective marker. This proves that the genetic factor for gentamicin resistance is present in the pheromone responsive plasmid. Among these twelve transaconjugants, seven isolates and one isolate were high biofilm formers on addition of E. faecalis FA2-2 and prior to its addition respectively. Out of the total 25 isolates, eight transconjugants for gentamicin resistance could turn to high biofilm formers on addition of the pheromone producing strain. All the isolates were resistant to more than two antibiotics tested. All the isolates were sensitive to vancomycin. The results indicate the significance of this nosocomial pathogen in biofilm formation and the role of pheromone responding clinical isolates of E. faecalis in spread of multidrug resistance genes.

  8. Isolation and characterization of diverse antimicrobial lipopeptides produced by Citrobacter and Enterobacter

    PubMed Central

    2013-01-01

    Background Increasing multidrug-resistance in bacteria resulted in a greater need to find alternative antimicrobial substances that can be used for clinical applications or preservation of food and dairy products. Research on antimicrobial peptides including lipopeptides exhibiting both narrow and broad spectrum inhibition activities is increasing in the recent past. Therefore, the present study was aimed at isolation and characterization of antimicrobial lipopeptide producing bacterial strains from fecal contaminated soil sample. Results The phenotypic and 16S rRNA gene sequence analysis of all isolates identified them as different species of Gram-negative genera Citrobacter and Enterobacter. They exhibited common phenotypic traits like citrate utilization, oxidase negative and facultative anaerobic growth. The HPLC analysis of solvent extracts obtained from cell free fermented broth revealed the presence of multiple antimicrobial lipopeptides. The comprehensive mass spectral analysis (MALDI-TOF MS and GC-MS) of HPLC purified fractions of different isolates revealed that the lipopeptides varied in their molecular weight between (m/z) 607.21 to 1536.16 Da. Isomers of mass ion m/z 984/985 Da was produced by all strains. The 1495 Da lipopeptides produced by strains S-3 and S-11 were fengycin analogues and most active against all strains. While amino acid analysis of lipopeptides suggested most of them had similar composition as in iturins, fengycins, kurstakins and surfactins, differences in their β-hydroxy fatty acid content proposed them to be isoforms of these lipopeptides. Conclusion Although antimicrobial producing strains can be used as biocontrol agents in food preservation, strains with ability to produce multiple antimicrobial lipopeptides have potential applications in biotechnology sectors such as pharmaceutical and cosmetic industry. This is the first report on antibacterial lipopeptides production by strains of Citrobacter and Enterobacter. PMID

  9. Emergence of Carbapenemase-Producing Escherichia coli Isolated from Companion Animals in Algeria.

    PubMed

    Yousfi, Massilia; Touati, Abdelaziz; Mairi, Assia; Brasme, Lucien; Gharout-Sait, Alima; Guillard, Thomas; De Champs, Christophe

    2016-06-01

    The emergence and worldwide spread of carbapenemase-producing Enterobacteriaceae is of great concern to public health. The aim of this study was to investigate the occurrence of carbapenemase-producing Escherichia coli in companion animals in Algeria. Two hundred fecal samples were obtained from healthy and diseased dogs and cats in one veterinary office and private owners in Bejaia city, Algeria, during November 2014 to March 2015. Isolates were screened by polymerase chain reaction for the presence of carbapenemase, acquired plasmidic AmpC (pAmpC) and extended-spectrum beta-lactamase genes. Five carbapenemase-producing E. coli isolates were detected including four OXA-48-producing isolates and one isolate producing NDM-5. Coexpression of ESBL and pAmpC genes was observed in these isolates. Phylogenetic grouping revealed that these isolates belonged to A and D phylogroups. The results of this study show that carbapenemase-producing E. coli spread to the companion animals in Algeria.

  10. Draft Genome Sequences of Two Marinitoga camini Isolates Producing Bacterioviruses

    PubMed Central

    Mercier, Coraline; Lossouarn, Julien; Haverkamp, Thomas; Bienvenu, Nadège; Godfroy, Anne; Cueff-Gauchard, Valérie

    2016-01-01

    Here, we present the draft genome sequences of two thermophilic Marinitoga strain members of the Thermotogales order, Marinitoga camini DV1155 and Marinitoga camini DV1197. These strains were isolated from deep-sea hydrothermal vents of the Mid-Atlantic Ridge. PMID:27834711

  11. Isolation Characterization and Fermented Research of High Producing Saccharamyces Cerevisae

    NASA Astrophysics Data System (ADS)

    Zhaochunhai

    In order to improve to alcoholic production,this paper researched on 122 strains of yeast isolated from orchard and vegetable plot through morphology and molecular biology, screening 17 strains of Saccharomyces cerevisiae through NCBI-blast, selected four yeasts to ferment,amongof them T13 used sorghum as raw material production capacity of 12.48% (v/v).

  12. Comparison of atypical Brachyspira spp. clinical isolates and classic strains in a mouse model of swine dysentery.

    PubMed

    Burrough, Eric; Strait, Erin; Kinyon, Joann; Bower, Leslie; Madson, Darin; Schwartz, Kent; Frana, Timothy; Songer, J Glenn

    2012-12-07

    Multiple Brachyspira spp. can colonize the porcine colon, and the presence of the strongly beta-hemolytic Brachyspira hyodysenteriae is typically associated with clinical swine dysentery. Recently, several Brachyspira spp. have been isolated from the feces of pigs with clinical disease suggestive of swine dysentery, yet these isolates were not identified as B. hyodysenteriae by genotypic or phenotypic methods. This study used a mouse model of swine dysentery to compare the pathogenic potential of seventeen different Brachyspira isolates including eight atypical clinical isolates, six typical clinical isolates, the standard strain of B. hyodysenteriae (B204), and reference strains of Brachyspira intermedia and Brachyspira innocens. Results revealed that strongly beta-hemolytic isolates induced significantly greater cecal inflammation than weakly beta-hemolytic isolates regardless of the genetic identification of the isolate, and that strongly beta-hemolytic isolates identified as 'Brachyspira sp. SASK30446' and B. intermedia by PCR produced lesions indistinguishable from those caused by B. hyodysenteriae in this model.

  13. Specific Gene Loci of Clinical Pseudomonas putida Isolates

    PubMed Central

    Molina, Lázaro; Udaondo, Zulema; Duque, Estrella; Fernández, Matilde; Bernal, Patricia; Roca, Amalia; de la Torre, Jesús; Ramos, Juan Luis

    2016-01-01

    Pseudomonas putida are ubiquitous inhabitants of soils and clinical isolates of this species have been seldom described. Clinical isolates show significant variability in their ability to cause damage to hosts because some of them are able to modulate the host’s immune response. In the current study, comparisons between the genomes of different clinical and environmental strains of P. putida were done to identify genetic clusters shared by clinical isolates that are not present in environmental isolates. We show that in clinical strains specific genes are mostly present on transposons, and that this set of genes exhibit high identity with genes found in pathogens and opportunistic pathogens. The set of genes prevalent in P. putida clinical isolates, and absent in environmental isolates, are related with survival under oxidative stress conditions, resistance against biocides, amino acid metabolism and toxin/antitoxin (TA) systems. This set of functions have influence in colonization and survival within human tissues, since they avoid host immune response or enhance stress resistance. An in depth bioinformatic analysis was also carried out to identify genetic clusters that are exclusive to each of the clinical isolates and that correlate with phenotypical differences between them, a secretion system type III-like was found in one of these clinical strains, a determinant of pathogenicity in Gram-negative bacteria. PMID:26820467

  14. Resistance to apramycin in two enterobacterial clinical isolates: detection of a 3-N-acetyltransferase IV.

    PubMed

    Gómez-Lus, R; Rivera, M J; Gómez-Lus, M L; Gil, J; Gómez-Lus, S; Castillo, J; Goñi, P; Madero, P; Rubio, M C

    1990-08-01

    Considering the possible role of farm animals in the contamination of human consumers by plasmid-mediated apramycin-resistant enterobacteria strains, this type of resistance should be tested more systematically in human isolates. Very recently we isolated in Zaragoza one apramycin-resistant Escheria coli strain obtained from the blood of a hospitalized patient; this clinical isolate produced a plasmid-mediated 3-N-aminoglycoside acetyltransferase IV. We describe also the isolation in Madrid of one multiresistant Klebsiella pneumoniae clinical strain. This isolate harbored a single plasmid and carried determinants for apramycin, gentamicin, tobramycin, hygromycin B, streptomycin, and ampicillin, which could be transferred en bloc to E. coli K-12 J62. Extracts from donor and transconjugant strains carrying pUZ6776 plasmid produce acetyltransferase activity AAC(3)-IV and double phosphotransferase activity (HPH and APH(3'')).

  15. Pathogenetic characterization of Vibrio parahaemolyticus isolates from clinical and seafood sources.

    PubMed

    Vongxay, Khamphouth; Wang, Shuna; Zhang, Xiaofeng; Wu, Beibei; Hu, Hongxia; Pan, Zijiang; Chen, Suyun; Fang, Weihuan

    2008-08-15

    A total of 216 Vibrio parahaemolyticus isolates from seafood and clinical samples in eastern China were investigated for their hemolytic and urea-producing phenotypes, presence of putative virulence genes tdh and trh. Twenty-one clinical isolates (84%, 21/25) and 3 seafood isolates (1.57%, 3/191) were tdh-positive while only 3 clinical isolates (12%) and 7 seafood isolates (3.66%) were positive for trh gene. We further examined the pathogenicity of selected V. parahaemolyticus isolates in in vitro and in vivo systems. The clinical isolates were apparently more enteropathogenic (74.26 per thousand vs 62.07 per thousand expressed as intestine/body weight ratio, P<0.01) and more virulent than their seafood counterparts to mice (log LD(50) 6.86 vs 7.40 via orogastric route, P<0.05). They were also more adherent to in vitro cultured cells and of higher cytotoxicity as measured by LDH release of the HeLa cells although there were no statistical differences. The tdh-positive V. parahaemolyticus isolates were of higher enteropathogenicity (P<0.05, 74.24 per thousand vs 60.55 per thousand) and more virulent (log LD(50) 6.55 vs 7.21 via intraperitoneal route, P<0.05) than tdh-negative isolates. The tdh-positive isolates were generally more cytotoxic and adhesive to the cultured cell lines as well. From the in vitro and in vivo pathogenicity profiles, trh-positive isolates seemed to line between tdh-positive isolates and those without tdh and trh. There were two isolates H8 and H10 from clinical cases having moderate enteropathogenicity and virulence to mice, but were tdh-negative yet trh-positive. These results seem to suggest that hemolysins TDH and/or TRH may not be necessarily the only virulence factors of pathogenic V. parahaemolyticus isolates.

  16. Association of biofilm production with colonization among clinical isolates of Acinetobacter baumannii

    PubMed Central

    Ryu, Seong Yeol; Baek, Won-Ki; Kim, Hyun Ah

    2017-01-01

    Background/Aims The pathogen Acinetobacter baumannii is increasingly causing healthcare-associated infections worldwide, particularly in intensive care units. Biofilm formation, a factor contributing to the virulence of A. baumannii, is associated with long-term persistence in hospital environments. The present study investigates the clinical impact of biofilm production on colonization and acquisition after patient admission. Methods Forty-nine A. baumannii isolates were obtained between August and November 2013 from Keimyung University Dongsan Medical Center, Daegu, Korea. All isolates were obtained from sputum samples of new patients infected or colonized by A. baumannii. The microtiter plate assay was used to determine biofilm formation. Results Twenty-four A. baumannii isolates (48%) demonstrated enhanced biofilm formation capacity than that of the standard A. baumannii strain (ATCC 19606). All isolates were resistant to carbapenem, 38 isolates (77%) were collected from patients in an intensive care unit, and 47 isolates (95%) were from patients who had been exposed to antibiotics in the previous month. The median duration of colonization was longer for biofilm-producing isolates than that of the biofilm non-biofilm producing isolates (18 days vs. 12 days, p < 0.05). Simultaneous colonization with other bacteria was more common for biofilm-producing isolates than that for the non-biofilm producing isolates. The most prevalent co-colonizing bacteria was Staphylococcus aureus. Conclusions Biofilm-producing isolates seem to colonize the respiratory tract for longer durations than the non-biofilm producing isolates. During colonization, biofilm producers promote co-colonization by other bacteria, particularly S. aureus. Additional research is required to determine possible links between biofilm formation and nosocomial infection. PMID:27653617

  17. Clinical significance of Bacillus species isolated from blood cultures.

    PubMed

    Weber, D J; Saviteer, S M; Rutala, W A; Thomann, C A

    1989-06-01

    To determine the clinical significance of blood isolates of Bacillus, we reviewed all blood cultures obtained at North Carolina Memorial Hospital between 1981 and 1985. Over the five-year study period the number of patients (incidence per 10,000 hospital admissions) from whom Bacillus was isolated increased from 4.97 in 1981 to 12.5 in 1985. The incidence per 1,000 blood cultures also increased from 1.12 in 1981 to 2.33 in 1985. Review of the medical records of 78 of the 95 patients (82%) with positive cultures allowed retrospective classification of five isolates (6.4%) as clinically significant, 33 isolates (42.3%) as possibly significant, and 40 isolates (51.3%) as nonsignificant. Underlying diseases in patients with clinically significant Bacillus bacteremia included burn trauma in two, leukemia in one, carcinoma in one, and gastrointestinal hemorrhage in one. All isolates judged to be clinically significant and the majority of possibly significant isolates were B cereus. We conclude that the isolation of Bacillus species from blood cultures is clinically significant in 5% to 10% of cases, that the incidence of Bacillus bacteremia is increasing, and that burn trauma should be added to the list of conditions known to predispose to clinically significant Bacillus bacteremia.

  18. Association of KPC-producing Klebsiella pneumoniae colonization or infection with Candida isolation and selection of non-albicans species.

    PubMed

    Papadimitriou-Olivgeris, Matthaios; Spiliopoulou, Anastasia; Fligou, Fotini; Manolopoulou, Patroula; Spiliopoulou, Iris; Vrettos, Theofanis; Dodou, Vasiliki; Filos, Kriton S; Anastassiou, Evangelos D; Marangos, Markos; Christofidou, Myrto

    2014-11-01

    Clinical specimens from 565 patients hospitalized in 2 intensive care units (ICUs A and B) during a 28-month period were cultured on appropriate media for isolation of Candida. Forty-nine (9%) patients had at least a Candida spp.-positive sample. Candida albicans was the predominant species isolated from 26 (53%) patients. Seventeen patients (3%) developed candidemia. Multivariate analysis showed that obesity, female gender, hospitalization during summer months, admission at ICU B, parenteral nutrition, administration of metronidazole, transplantation, and KPC-producing Klebsiella pneumoniae (KPC-Kp) infection were independently associated with Candida spp. isolation. Candidemia was associated with cortisone administration, KPC-Kp infection, and presence of colostomy or abdominal catheter. Administration of fluconazole was a protective factor for both Candida spp. isolation and infection, leading to selection of Candida non-albicans species. Among several risk factors, KPC-Kp infection and colonization are identified as statistically significant factors associated with Candida isolation, especially of non-albicans species.

  19. Therapeutic clinical applications of reactor-produced radioisotopes

    SciTech Connect

    Knapp, F.F. Jr.

    1997-12-01

    One of the most rapidly growing areas of clinical nuclear medicine is the therapeutic use of radioisotopes for applications in oncology, rheumatology and, more recently, interventional cardiology. With the rapidly increasing development and evaluation of new agents, their introduction into clinical use, and commercialization, the availability of high levels of therapeutic reactor-produced neutron-rich radioisotopes is of increasing importance. The goals of this paper are to discuss the issues associated with optimization of the production and processing of reactor-produced radioisotopes for therapy, with special emphasis on {sup 188}W, and the optimization of the use of the {sup 188}W/{sup 188}Re generator. In addition, other key examples of therapeutic radioisotopes of current interest and their specific clinical applications are discussed.

  20. Emergence of Metallo-β-Lactamase GIM-1 in a Clinical Isolate of Serratia marcescens

    PubMed Central

    Frontzek, Andre; Pfeifer, Yvonne

    2012-01-01

    The metallo-β-lactamase GIM-1 (German imipenemase) has been found so far only in clinical isolates of Pseudomonas aeruginosa from Germany. Here we report the detection of blaGIM-1 in a clinical strain of Serratia marcescens that was isolated from urine, blood, and wound samples over a period of 20 months. The strain was repeatedly isolated from one patient in two German hospitals and an outpatient department located in the region in which all previously described GIM-1-producing P. aeruginosa strains were identified. PMID:22710114

  1. Emergence of Multidrug Resistance and Metallo-beta-lactamase Producing Acinetobacter baumannii Isolated from Patients in Shiraz, Iran

    PubMed Central

    Moghadam, MN; Motamedifar, M; Sarvari, J; Sedigh, Ebrahim-Saraie H; Mousavi, Same M; Moghadam, FN

    2016-01-01

    Background: Metallo-beta-lactamase (MβL) enzymes production is one of the most important resistance mechanisms against carbapenems in some bacteria including Acinetobacter baumannii. Aims: This study was aimed to determine the antimicrobial susceptibility and the prevalence of MβL among carbapenem-resistant isolates of A. baumannii. Materials and Methods: In this cross-sectional study from October 2012 to April 2013, 98 isolates were identified as A. baumannii using Microgen™ kits and confirmed by molecular method. These isolates were tested for antimicrobial susceptibilities by disk diffusion method according to the Clinical and Laboratory Standards Institute guidelines. Carbapenem-resistant isolates were further detected phenotypically by MβL minimal inhibitory concentration (MIC)-test strips, and subsequently positive MβL isolates were confirmed by polymerase chain reaction (PCR). Results: Overall, 98% (96/98) of A. baumannii isolates were detected as carbapenem-resistant by MIC test. Highest sensitivity to the tested antibiotic with 42.9% (42/98) was observed to colistin. Of 96 carbapenem-resistant isolates, 43 were phenotypically positive for MβL; out of 43 isolates, 37 were confirmed for the presence of MβL genes by PCR. Conclusion: The frequency of drug resistance among the clinical samples of A. baumannii isolated in our study against most of the antibiotics was very high. Moreover, all MβL producing isolates were multidrug resistance. Therefore, systematic surveillance to detect MβL producing bacteria and rational prescription and use of carbapenems could be helpful to prevent the spread of carbapenem resistance. PMID:27398247

  2. First Isolate of KPC-2-Producing Klebsiella pneumonaie Sequence Type 23 from the Americas

    PubMed Central

    Cejas, Daniela; Fernández Canigia, Liliana; Rincón Cruz, Giovanna; Elena, Alan X.; Maldonado, Ivana; Gutkind, Gabriel O.

    2014-01-01

    KPC-2-producing Klebsiella pneumoniae isolates mainly correspond to clonal complex 258 (CC258); however, we describe KPC-2-producing K. pneumoniae isolates belonging to invasive sequence type 23 (ST23). KPC-2 has scarcely been reported to occur in ST23, and this report describes the first isolation of this pathogen in the Americas. Acquisition of resistant markers in virulent clones could mark an evolutionary step toward the establishment of these clones as major nosocomial pathogens. PMID:25031447

  3. First isolate of KPC-2-producing Klebsiella pneumonaie sequence type 23 from the Americas.

    PubMed

    Cejas, Daniela; Fernández Canigia, Liliana; Rincón Cruz, Giovanna; Elena, Alan X; Maldonado, Ivana; Gutkind, Gabriel O; Radice, Marcela A

    2014-09-01

    KPC-2-producing Klebsiella pneumoniae isolates mainly correspond to clonal complex 258 (CC258); however, we describe KPC-2-producing K. pneumoniae isolates belonging to invasive sequence type 23 (ST23). KPC-2 has scarcely been reported to occur in ST23, and this report describes the first isolation of this pathogen in the Americas. Acquisition of resistant markers in virulent clones could mark an evolutionary step toward the establishment of these clones as major nosocomial pathogens.

  4. Successive emergence of extended-spectrum beta-lactamase-producing and carbapenemase-producing Enterobacter aerogenes isolates in a university hospital.

    PubMed

    Biendo, M; Canarelli, B; Thomas, D; Rousseau, F; Hamdad, F; Adjide, C; Laurans, G; Eb, F

    2008-03-01

    Sixty-two clinical isolates of Enterobacter aerogenes resistant to expanded-spectrum cephalosporins were collected between July 2003 and May 2005. Among these isolates, 23 (37.1%) were imipenem (IPM) susceptible, and 39 (62.9%) were IPM insusceptible, of which 89.7% (35/39) were resistant and 10.3% (4/39) were intermediate. Isolate genotypes were compared by pulsed-field gel electrophoresis. Of 62 isolates, 48 belonged to epidemic pulsotype A (77.4%). This pulsotype included 37.5% and 58.4% of beta-lactam phenotypes b and a, respectively. Nine isolates (14.5%) belonged to pulsotype E, which included 22.3% and 77.7% of phenotypes b and a, respectively. The beta-lactamases with pIs of 5.4, 6.5, 8.2, and 8.2 corresponded to extended-spectrum beta-lactamases (ESBLs) TEM-20, TEM-24, SHV-5, and SHV-12, respectively. Of 39 IPM-insusceptible E. aerogenes isolates, 26 (66.6%) were determined to be metallo-beta-lactamase producers, by using a phenotypic method. Of these isolates, 24 harbored a bla(IMP-1) gene encoding a protein with a pI of >9.5, and two carried the bla(VIM-2) gene encoding a protein with a pI of 5.3, corresponding to beta-lactamases IMP-1 and VIM-2, respectively. The remaining 13 (33.4%) isolates were negative for the bla(IMP-1) and bla(VIM-2) genes but showed an alteration of their outer membrane proteins (OMPs). Ten of these isolates produced the two possible OMPs (32 and 42 kDa), with IPM MICs between 8 and 32 microg/ml, and three others produced only a 32-kDa OMP with IPM MICs >32 microg/ml. This work demonstrates that, in addition to resistance to expanded-spectrum cephalosporins, IPM resistance can occur in ESBL-producing E. aerogenes isolates by carbapenemase production or by the loss of porin in the outer membrane.

  5. Isolation and characterization of biosurfactant producing bacteria from Persian Gulf (Bushehr provenance).

    PubMed

    Hassanshahian, Mehdi

    2014-09-15

    Biosurfactants are surface active materials that are produced by some microorganisms. These molecules increase biodegradation of insoluble pollutants. In this study sediments and seawater samples were collected from the coastline of Bushehr provenance in the Persian Gulf and their biosurfactant producing bacteria were isolated. Biosurfactant producing bacteria were isolated by using an enrichment method in Bushnell-Hass medium with diesel oil as the sole carbon source. Five screening tests were used for selection of Biosurfactant producing bacteria: hemolysis in blood agar, oil spreading, drop collapse, emulsification activity and Bacterial Adhesion to Hydrocarbon test (BATH). These bacteria were identified using biochemical and molecular methods. Eighty different colonies were isolated from the collected samples. The most biosurfactant producing isolates related to petrochemical plants of Khark Island. Fourteen biosurfactant producing bacteria were selected between these isolates and 7 isolates were screened as these were predominant producers that belong to Shewanella alga, Shewanella upenei, Vibrio furnissii, Gallaecimonas pentaromativorans, Brevibacterium epidermidis, Psychrobacter namhaensis and Pseudomonas fluorescens. The largest clear zone diameters in oil spreading were observed for G. pentaromativorans strain O15. Also, this strain has the best emulsification activity and reduction of surface tension, suggesting it is the best of thee isolated strains. The results of this study confirmed that there is high diversity of biosurfactant producing bacteria in marine ecosystem of Iran and by application of these bacteria in petrochemical waste water environmental problems can be assisted.

  6. Dissemination of multiresistant Enterobacter cloacae isolates producing OXA-48 and CTX-M-15 in a Spanish hospital.

    PubMed

    Fernández, Javier; Montero, Ignacio; Martínez, Óscar; Fleites, Ana; Poirel, Laurent; Nordmann, Patrice; Rodicio, M Rosario

    2015-10-01

    Twenty-one multiresistant Enterobacter cloacae isolates producing OXA-48 (n=10), CTX-M-15 (n=7) or both (n=4) β-lactamases were detected in a Spanish hospital during a 1-year period (June 2013 to June 2014). The isolates were also resistant to non-β-lactam antimicrobials, further complicating the therapeutic options. Genotyping of the isolates identified two major clones (ST74 and ST66) that caused prolonged outbreaks in different buildings of the hospital as well as some sporadic isolates (ST78, ST45 and ST295). Isolates belonging to clone 1 (n=7) were carbapenem-resistant and carried the bla(OXA-48) gene on a conjugative IncL/M plasmid of ca. 65 kb. Clone 2 isolates (n=11) were resistant to cefepime and harboured the bla(CTX-M-15) gene on an ca. 150-kb, non-conjugative plasmid of the IncF group, co-harbouring the qnrB and aac(6')-Ib-cr genes encoding quinolone resistance. Four clone 2 isolates were also resistant to carbapenems owing to the co-production of OXA-48. Most of the isolates were recovered from critically ill patients and were admitted to intensive care units; a single patient was transferred from another Spanish hospital. Intrahospital and interhospital dissemination of multiresistant E. cloacae isolates is of major clinical concern as it could lead to endemic nosocomial situations.

  7. Candida biotypes isolated from clinical specimens in Malaysia.

    PubMed

    Ng, K P; Madasamy, M; Saw, T L; Baki, A; He, J; Soo-Hoo, T S

    The distribution of Candida species was examined using 1114 yeasts isolated from various clinical specimens. The isolates were identified by germ tube test, hyphal/pseudohyphae and chlamydoconidia production and carbohydrate assimilation test using ten carbohydrates (glucose, sucrose, trehalose, cellobiose, arabinose, galactose, mannitol, raffinose, lactose and maltose). Among the 1114 isolates studied, 9 species of Candida were identified and the relative frequency of isolation was C. albicans (44.2%), C. parapsilosis (26.0%), C. tropicalis (17.7%), C. glabrata (9.6%), C. krusei (1.2%), C. rugosa (0.6%), C. guilliermondii (0.2%), C. lusitaniae (0.08%) and C. kefyr (0.08%). Non-C. albicans was the most common Candida species isolated from blood, respiratory system, urine and skin. The isolate from vaginal swabs was predominantly C. albicans. 82.2% of C. glabrata and 64.2% of C. krusei isolated in this study were from vaginal swabs.

  8. Chitinase 3-like 1: prognostic biomarker in clinically isolated syndromes.

    PubMed

    Cantó, Ester; Tintoré, Mar; Villar, Luisa M; Costa, Carme; Nurtdinov, Ramil; Álvarez-Cermeño, José C; Arrambide, Georgina; Reverter, Ferran; Deisenhammer, Florian; Hegen, Harald; Khademi, Mohsen; Olsson, Tomas; Tumani, Hayrettin; Rodríguez-Martín, Eulalia; Piehl, Fredrik; Bartos, Ales; Zimova, Denisa; Kotoucova, Jolana; Kuhle, Jens; Kappos, Ludwig; García-Merino, Juan Antonio; Sánchez, Antonio José; Saiz, Albert; Blanco, Yolanda; Hintzen, Rogier; Jafari, Naghmeh; Brassat, David; Lauda, Florian; Roesler, Romy; Rejdak, Konrad; Papuc, Ewa; de Andrés, Clara; Rauch, Stefan; Khalil, Michael; Enzinger, Christian; Galimberti, Daniela; Scarpini, Elio; Teunissen, Charlotte; Sánchez, Alex; Rovira, Alex; Montalban, Xavier; Comabella, Manuel

    2015-04-01

    Chitinase 3-like 1 (CHI3L1) has been proposed as a biomarker associated with the conversion to clinically definite multiple sclerosis in patients with clinically isolated syndromes, based on the finding of increased cerebrospinal fluid CHI3L1 levels in clinically isolated syndrome patients who later converted to multiple sclerosis compared to those who remained as clinically isolated syndrome. Here, we aimed to validate CHI3L1 as a prognostic biomarker in a large cohort of patients with clinically isolated syndrome. This is a longitudinal cohort study of clinically isolated syndrome patients with clinical, magnetic resonance imaging, and cerebrospinal fluid data prospectively acquired. A total of 813 cerebrospinal fluid samples from patients with clinically isolated syndrome were recruited from 15 European multiple sclerosis centres. Cerebrospinal fluid CHI3L1 levels were measured by enzyme-linked immunosorbent assay. Multivariable Cox regression models were used to investigate the association between cerebrospinal fluid CHI3L1 levels and time to conversion to multiple sclerosis and time to reach Expanded Disability Status Scale 3.0. CHI3L1 levels were higher in patients who converted to clinically definite multiple sclerosis compared to patients who continued as clinically isolated syndrome (P = 8.1 × 10(-11)). In the Cox regression analysis, CHI3L1 levels were a risk factor for conversion to multiple sclerosis (hazard ratio = 1.7; P = 1.1 × 10(-5) using Poser criteria; hazard ratio = 1.6; P = 3.7 × 10(-6) for McDonald criteria) independent of other covariates such as brain magnetic resonance imaging abnormalities and presence of cerebrospinal fluid oligoclonal bands, and were the only significant independent risk factor associated with the development of disability (hazard ratio = 3.8; P = 2.5 × 10(-8)). High CHI3L1 levels were associated with shorter time to multiple sclerosis (P = 3.2 × 10(-9) using Poser criteria; P = 5.6 × 10(-11) for McDonald criteria

  9. NDM-1 and rmtC-Producing Klebsiella pneumoniae Isolates in Turkey

    PubMed Central

    Guven Gokmen, Tulin; Nagiyev, Togrul; Meral, Melda; Onlen, Cansu; Heydari, Farzad; Koksal, Fatih

    2016-01-01

    Background The resistance of aminoglycosides in strains that produce beta-lactamase can be developed through the multidrug resistant encoding genes carried by common plasmids. Recently, the association between 16S rRNA methyltransferase resistance and beta-lactamase enzymes carried by the same plasmids has drawn increased attention from researchers, particularly the association in aminoglycoside-resistant strains with a minimum inhibitory concentration (MIC) of ≥ 256 µg/mL. Objectives We aimed to investigate the co-existence of 16S rRNA methyltransferase and beta-lactamase genes in multidrug resistant (MDR) Klebsiella pneumoniae strains isolated from clinical samples. Methods We determined the molecular mechanisms of aminoglycoside resistance and its relationship with resistance to carbapenem and beta-lactam group antibiotics in 40 extended-spectrum beta-lactamase (ESBL)-positive carbapenem- and aminoglycoside-resistant K. pneumoniae strains. Multidrug resistant K. pneumoniae was isolated from various clinical samples in the faculty of medicine of Cukurova University, Turkey. First, the resistance of aminoglycoside and beta-lactam antibiotics was phenotypically investigated using the Kirby-Bauer disk diffusion test, double disk synergy test, and modified Hodge test. The MIC values of aminoglycoside were determined using the agar dilution method. Polymerase chain reaction was performed to detect the carbapenemases, ESBL, and 16S rRNA methyltransferase genes. The results were confirmed by a sequence analysis. Results Twenty K. pneumoniae strains showed resistance to amikacin, and 40 were resistant to gentamicin. The MIC value was found to be > 512 µg/mL in five amikacin-resistant strains and > 128 µg/mL in 10 gentamicin-resistant isolates. The rmtC gene, a type of 16S rRNA methyltransferase, was amplified in four isolates (MIC amikacin: > 512 µg/mL, gentamicin: > 128 µg/mL). Of these four isolates, three had the blaNDM-1 gene and all contained at least one

  10. Virulence factors in clinical and food isolates of Aeromonas species.

    PubMed

    Pin, C; Marín, M L; Selgas, M D; García, M L; Tormo, J; Casas, C

    1994-01-01

    Virulence factors were compared in 15 Aeromonas spp. isolated from faeces of patients with Aeromonas-associated gastroenteritis and in 81 strains isolated from food. Strains from food did not show differences in the distribution of virulence factors when compared with strains isolated from faeces. However, 88.8% of Aeromonas strains isolated from food were capable of producing possible virulence factors. Characterization of 28 autoagglutinating (AA+) Aeromonas spp. indicated that the human strains differed from the food strains in hemagglutinating and hemolytic capacities. These results suggest that autoagglutination associated with hemagglutinating and hemolytic capacities in food strains may be a helpful indicator of potential pathogenicity.

  11. Isolation and characterization of halophilic Archaea able to produce biosurfactants.

    PubMed

    Kebbouche-Gana, S; Gana, M L; Khemili, S; Fazouane-Naimi, F; Bouanane, N A; Penninckx, M; Hacene, H

    2009-05-01

    Halotolerant microorganisms able to live in saline environments offer a multitude of actual or potential applications in various fields of biotechnology. This is why some strains of Halobacteria from an Algerian culture collection were screened for biosurfactant production in a standard medium using the qualitative drop-collapse test and emulsification activity assay. Five of the Halobacteria strains reduced the growth medium surface tension below 40 mN m(-1), and two of them exhibited high emulsion-stabilizing capacity. Diesel oil-in-water emulsions were stabilized over a broad range of conditions, from pH 2 to 11, with up to 35% sodium chloride or up to 25% ethanol in the aqueous phase. Emulsions were stable to three cycles of freezing and thawing. The components of the biosurfactant were determined; it contained sugar, protein and lipid. The two Halobacteria strains with enhanced biosurfactant producers, designated strain A21 and strain D21, were selected to identify by phenotypic, biochemical characteristics and by partial 16S rRNA gene sequencing. The strains have Mg(2+), and salt growth requirements are always above 15% (w/v) salts with an optimal concentration of 15-25%. Analyses of partial 16S rRNA gene sequences of the two strains suggested that they were halophiles belonging to genera of the family Halobacteriaceae, Halovivax (strain A21) and Haloarcula (strain D21). To our knowledge, this is the first report of biosurfactant production at such a high salt concentration.

  12. Clinical and molecular epidemiology of hospital Enterococcus faecalis isolates in eastern France.

    PubMed

    Mulin, Blandine; Bailly, Pascale; Thouverez, Michelle; Cailleaux, Vincent; Cornette, Christian; Dupont, Marie-Jeanne; Talon, Daniel

    1999-03-01

    OBJECTIVE: To report on the occurrence of Enterococcus faecalis hospital isolates obtained during 1 year in hospitals in the Franche-Comté region of France. METHODS: Clinical isolates of E. faecalis of different antibiotic susceptibility phenotypes from hospitalized patients were characterized by pulsed-field gel electrophoresis. Patients with positive cultures were investigated by three case-control studies to identify risk factors for colonization/infection. RESULTS: The crude incidence of colonization/infection was 2.37%, and 4-day and 7-day colonization rates after admission were 10.0% and 6.36%, respectively. The rates of high-level resistance to kanamycin (HLKR) and to gentamicin (HLGR) were 47.1% and 7.1%, respectively. No isolate was resistant to glycopeptides or produced beta-lactamase. The 209 hospital isolates obtained during the study yielded 98 major DNA patterns, of which two were major epidemic patterns including HLKR isolates. No single factor was significantly associated with colonization/infection by HLKR isolates. The length of hospitalization before isolation was associated with colonization by HLGR isolates. CONCLUSIONS: The isolation frequency of E. faecalis strains with acquired resistance to aminoglycoside antibiotics, and the wide dissemination of resistant strains with characteristics that allow them to persist and spread, argue for further large prospective surveys of clinical isolates of E. faecalis in hospitals.

  13. Epidemiology and Clinical Features of Bloodstream Infections Caused by AmpC-Type-β-Lactamase-Producing Klebsiella pneumoniae

    PubMed Central

    Pai, Hyunjoo; Kang, Cheol-In; Byeon, Jeong-Hum; Lee, Ki-Deok; Park, Wan Beom; Kim, Hong-Bin; Kim, Eui-Chong; Oh, Myoung-don; Choe, Kang-Won

    2004-01-01

    Cases of bacteremia caused by AmpC-type-β-lactamase-producing Klebsiella pneumoniae isolates were retrospectively studied to determine the epidemiologic features and clinical outcomes of bloodstream infections. Among 389 blood isolates recovered from 1998 to 2002, 65 isolates (16.7%) were found to be extended-spectrum β-lactamase (ESBL) or AmpC β-lactamase producers. The β-lactamases from 61 of the 65 isolates were characterized; 28 of 61 isolates produced AmpC-type enzymes (14 isolates each produced DHA-1 and CMY-1-like enzymes), 32 isolates produced TEM or SHV-related ESBLs, and 1 isolate produced a CTX-M-14-like enzyme. To compare the clinical features and outcomes of bloodstream infections caused by AmpC producers with those caused by TEM- or SHV-related ESBL producers, 27 patients infected with isolates producing AmpC-type enzymes (AmpC group) and 25 patients infected with isolates producing TEM- or SHV-related enzymes (ESBL group) were analyzed. There was no significant difference between the AmpC and the ESBL groups in terms of risk factors. When the initial response was assessed at 72 h after antimicrobial therapy, the treatment failure rate for the AmpC group was 51.9% (14 of 27 patients) and the 7- and 30-day mortality rates were 14.8 and 29.6%, respectively, which were similar to those for the ESBL group. When the mortality rate for the patients who received extended-spectrum cephalosporins as definitive treatment was assessed, all four patients in the DHA-1 group and one of three patients in the CMY-1-like group died. In summary, the prevalence of AmpC enzyme-producing K. pneumoniae was high at the Seoul National University Hospital, and the clinical features and outcomes for the patients infected with AmpC-producing organisms were similar to those for the patients infected with TEM- or SHV-related ESBL producers. PMID:15388426

  14. Bacteriocinogenic Bacteria Isolated from Raw Goat Milk and Goat Cheese Produced in the Center of México.

    PubMed

    Hernández-Saldaña, Oscar F; Valencia-Posadas, Mauricio; de la Fuente-Salcido, Norma M; Bideshi, Dennis K; Barboza-Corona, José E

    2016-09-01

    Currently, there are few reports on the isolation of microorganisms from goat milk and goat cheese that have antibacterial activity. In particular, there are no reports on the isolation of microorganisms with antibacterial activity from these products in central Mexico. Our objective was to isolate bacteria, from goat products, that synthesized antimicrobial peptides with activity against a variety of clinically significant bacteria. We isolated and identified Lactobacillus rhamnosus, L. plantarum, L. pentosus, L. helveticus and Enterococcus faecium from goat cheese, and Aquabacterium fontiphilum, Methylibium petroleiphilum, Piscinobacter aquaticus and Staphylococcus xylosus from goat milk. These bacteria isolated from goat cheese were able to inhibit Staphylococcus aureus, Bacillus cereus, Escherichia coli, Listeria monocytogenes, L. inoccua, Pseudomona aeruginosa, Shigella flexneri, Serratia marcescens, Enterobacter cloacae and Klebsiella pneumoniae. In addition, bacteria from goat milk showed inhibitory activity against B. cereus, L. lactis, E. coli, S. flexneri, E. cloacae and K. pneumonia; S. aureus, L. innocua, S. agalactiae and S. marcescens. The bacteriocins produced by these isolates were shown to be acid stable (pH 2-6) and thermotolerant (up to 100 °C), but were susceptible to proteinases. When screened by PCR for the presence of nisin, pediocin and enterocin A genes, none was found in isolates recovered from goat milk, and only the enterocin A gene was found in isolates from goat cheese.

  15. Genotypic characterization of Malaysian human isolates of Streptococcus pneumoniae from carriage and clinical sources.

    PubMed

    Shakrin, Nik Noorul Shakira Mohamed; Masri, Siti Norbaya; Taib, Niazlin Mohd; Nordin, Syafinaz Amin; Jamal, Farida; Desa, Mohd Nasir Mohd

    2014-12-01

    This study characterized carriage and clinical pneumococcal isolates for serotypes, penicillin susceptibility, virulence genes and restriction fragment length polymorphism (RFLP) pattern of penicillin binding protein (PBP) genes. DNA fingerprint of isolates was generated by BOX-PCR. Majority of serotypes were 23F followed by 19F, 19A and 6A. Twenty-four percent of isolates were penicillin non-susceptible (PNSP). All of the targeted virulence genes were detected in all isolates with the exception of pili; 20.6% (n=22) for PI-1 and 14.0% (n=15) for PI-2. Of the 13 isolates which carried both PI-1 and PI-2, 10 were of clinical origin. Digested pbp-DNA produced three PBP-RFLP profiles for pbp1a (A1 to A3), six profiles for pbp2b (B1 to B6) and seven for pbp2x (X1 to X7) mostly in PNSPs. Based on BOX-PCR analysis, the majority of isolates were genetically diverse with a small number of potentially related isolates carrying pili genes. No obvious genotypic association was observed pertaining to carriage and clinical origin of isolates.

  16. Serological and antigenic profiles of clinical isolates of Paracoccidioides spp. from Central Western Brazil.

    PubMed

    Queiroz Júnior, Luiz de Pádua; de Camargo, Zoilo Pires; Tadano, Tomoko; Rodrigues, Anderson Messias; Takarara, Doracilde Terumi; Gegembauer, Gregory; Araujo, Leticia Mendes; Hahn, Rosane Christine

    2014-08-01

    Clinical Paracoccidioides spp. isolates from patients with paracoccidioidomycosis (PCM) in Mato Grosso, Brazil exhibit different patterns of serologic reactivity. The results observed for reactions of radial immunodiffusion against the commonly used exoantigens containing a 43-kDa glycoprotein (gp43) suggest that this fungus exhibits major antigenic variability by geographic region. There is a phylogenetic gap between Paracoccidioides spp. isolates among different regions of Latin America. In particular, those from the central region of Brazil (i.e. Mato Grosso state) exhibit a lower rate of genetic similarity. We aimed at investigating the phylogenetic classification of clinical isolates of Paracoccidioides spp. in Central Brazil and the different antigenic profiles that produce. Exoantigens were obtained from five clinical isolates: two P. brasiliensis (Pb166 and Pb2880) and three P. lutzii (PL2875, PL9840, and PL2912). The protein/glycoprotein profiles of P. lutzii exoantigens were different from each other. Isolate PL9840 exhibited the most distinct bands, and isolates PL2875 and PL2912 exhibited more diffuse bands and a very intense band between 50 and 60 kDa. P. brasiliensis isolates had similar protein profiles, exhibiting a low-intensity band at 220 kDa and a diffuse band between 50 and 60 kDa. P. lutzii isolates exhibit high species-specific antigen variability, which we have already been assessed in proteomic studies.

  17. Enterotoxin production, phage typing and serotyping of Staphylococcus aureus strains isolated from clinical materials and food.

    PubMed Central

    Melconian, A. K.; Brun, Y.; Fleurette, J.

    1983-01-01

    The production of enterotoxins A, B, C and F by strains of Staphylococcus aureus isolated from various clinical sources and from isolates implicated in food poisoning was investigated. One hundred and ninety one of the 374 clinical strains (51.1%) were found to be enterotoxigenic; of these, 81 (27.7%) strains produced enterotoxin A, 57 (15.3%) strains produced enterotoxin B, 23 (6.2%) strains produced enterotoxin C, and 64 (17.1%) strains produced enterotoxin F. These enterotoxigenic strains were most frequently lysed by phages of group III (21.5%) or were not typable (22%). Eighteen of the 29 strains implicated in food poisoning were enterotoxigenic. The correlation of antigens and bacteriophage patterns with enterotoxigenicity was determined: enterotoxin A being related to a4 antigen, enterotoxin B to phages of 94/96 complex with c1, o antigens, and enterotoxin F to phages of group I with 2632, k1k2, m antigens. PMID:6227656

  18. Biofilm-producing ability of Listeria monocytogenes isolates from Brazilian cheese processing plants.

    PubMed

    In Lee, Sarah Hwa; Barancelli, Giovana Verginia; de Camargo, Tarsila Mendes; Corassin, Carlos Humberto; Rosim, Roice Eliana; da Cruz, Adriano Gomes; Cappato, Leandro Pereira; de Oliveira, Carlos Augusto Fernandes

    2017-01-01

    The persistence of Listeria monocytogenes in food industry environments has been associated to the ability of specific isolates to produce biofilms. This study aimed to evaluate the biofilm production of 85 L. monocytogenes strains previously isolated from samples of cheese, brine and the environment of two cheese processing plants located in São Paulo, Brazil. The L. monocytogenes isolates belonged to serotypes 4b, 1/2b and 1/2c, yielded 30 different pulsotypes by pulsed-field gel electrophoresis (PFGE), and were submitted to biofilm-formation assays on polystyrene microplates and stainless steel coupons incubated statically at 35±0.5°C for 48h. All isolates from different sources showed ability to produce biofilms on polystyrene microplates, from which 21 (24.7%) also produced biofilms on stainless steel. Four isolates (4.7%) belonging to four different pulsotypes were classified as strong biofilms-producers on polystyrene microplates, while isolates belonging to four pulsotypes previously evaluated as persistent had weak or moderate ability to produce biofilms on polystyrene microplates. No relationship between the serotypes or pulsotypes and their biofilm-forming ability was observed. This study highlights the high variability in the biofilm production among L. monocytogenes strains collected from cheese and cheese-production environment, also indicating that strong biofilm-formation ability is not a key factor for persistence of specific isolates in cheese processing plants.

  19. Outbreak of NDM-1-producing Klebsiella pneumoniae ST76 and ST37 isolates in neonates.

    PubMed

    Zhu, J; Sun, L; Ding, B; Yang, Y; Xu, X; Liu, W; Zhu, D; Yang, F; Zhang, H; Hu, F

    2016-04-01

    The purpose of this study was to investigate the epidemiological characteristics of carbapenem-resistant Klebsiella pneumoniae (CRKP) in Shanghai Children's Hospital in China. Twenty-two non-duplicate CRKP strains were collected from pediatric patients between March and June in 2014. Antimicrobial susceptibility testing was conducted by the agar dilution method. Beta-lactamases were characterized by polymerase chain reaction (PCR) and DNA sequencing. The transferability of bla NDM-1 was investigated by conjugation experiment. The plasmids bearing antibiotic resistance genes were characterized by S1 nuclease pulsed-field gel electrophoresis (S1-PFGE) and Southern hybridization. Clonal relatedness was evaluated by PFGE and multilocus sequence typing (MLST). The clinical data of patients were retrospectively reviewed. The 22 CRKP strains were resistant to most of the antimicrobial agents tested, except tigecycline and colistin. Overall, 59, 77, and 100 % of these strains were resistant to imipenem, meropenem, and ertapenem, respectively. The bla NDM-1 was positive in 77.3 % (17/22) of the CRKP strains, of which the 16 isolates from inpatients were designated as ST37 (n = 9) and ST76 (n =7) and one isolate from an outpatient belonged to ST846. The 17 bla NDM-1-positive isolates belonged to PFGE type A (n = 9), type C (n = 7), or type B (n = 1). The plasmids bearing bla NDM-1 could be transferred into recipient Escherichia coli J53 through conjugation in 88.2 % (15/17) of the strains. The hybridization results showed that the plasmids carrying the bla NDM-1 gene were approximately 50-240 kb in size. This is the first report of an outbreak caused by NDM-1-producing K. pneumoniae ST76 and ST37 among neonates.

  20. Isolation and partial characterization of cyclic lipopeptide antibiotics produced by Paenibacillus ehimensis B7

    PubMed Central

    2013-01-01

    Background The prevalence of drug-resistant bacteria has encouraged the search for novel antimicrobial compounds. Food-associated microorganisms, as a source of new antibiotics, have recently received considerable attention. The objective of this study was to find novel antimicrobial agents produced by food microorganisms. Results A bacterial strain B7, which has potent antimicrobial activity, was isolated from a sample of dairy waste. This strain was identified as Paenibacillus ehimensis based on the 16S rRNA gene sequence analysis, physiological and biochemical characterization. Two active compounds (PE1 and PE2) were obtained from P. ehimensis B7. Mass spectrometry (MS) analysis showed that the molecular masses of PE1 and PE2 were 1,114 and 1,100 Da, respectively. The tandem MS and amino acid analysis indicated that PE1 and PE2 were analogs of polypeptin, and PE2 was characterized as a new member of this family. Both compounds were active against all tested bacterial pathogens, including methicillin resistant Staphylococcus aureus, Escherichia coli, and pan-drug resistant Pseudomonas aeruginosa clinical isolate. Time-kill assays demonstrated that at 4 × MIC (minimum inhibitory concentration), PE1 and PE2 rapidly reduced the number of viable cells by at least 3-orders of magnitude, indicating that they were bactericidal antibiotics. Conclusions In the present work, two cationic lipopeptide antibiotics (PE1 and PE2) were isolated from P. ehimensis B7 and characterized. These two peptides showed broad antimicrobial activity against all tested human pathogens and are worthy of further study. PMID:23594351

  1. Prevalence of Class D Carbapenemases among Extended-Spectrum β-Lactamases Producing Escherichia coli Isolates from Educational Hospitals in Shahrekord

    PubMed Central

    Damavandi, Mohammad-Sadegh; Latif Pour, Mohammad

    2016-01-01

    Introduction Extended-spectrum β-lactamases (ESBLs) are a set of plasmid-borne, various and quickly evolving enzymes that are a main therapeutic issue now-a-days for inpatient and outpatient treatment. Aim The aim of this study was to determine multi-drug resistance (MDR) and ESBLs producing E. coli strains, prevalence of class D Carbapenemases among ESBLs producing Escherichia coli isolates from educational hospitals in Shahrekord, Iran. Materials and Methods Uropathogenic Escherichia coli strains were isolated from patients with Urinary Tract Infections (UTIs). The agar disc diffusion test was used to characterize the antimicrobial sensitivity of the E. coli isolates. The ESBL positive strains were identified by phenotypic double-disk synergy test, by third-generation cephalosporin in combination with or without clavulanic acid. Multiplex PCR was carried out for detection of the three families of OXA-type carbapenamases including OXA-23, OXA-24, and OXA-48 in E. coli strains. Results All bacterial isolates were susceptible to meropenem. Ninety isolates produced ESBL, 55 E. coli isolates from inpatients, and 35 isolates from outpatients, with a significant association (p< 0.05). The prevalence of OXA-23, OXA-24, and OXA-48 in the ESBLs producing isolates was respectively 21%, 18%, and 11% for inpatients, and 10%, 8%, and 6% for outpatients. Conclusion ESBL-producing E. coli isolates are also a major threat in the clinical setting. The findings of this study indicated the high occurrence of ESBLs and multiple antibiotic resistance in E. coli isolates. PMID:27462579

  2. Comparative analysis of the volatile metabolomes of Pseudomonas aeruginosa clinical isolates.

    PubMed

    Bean, Heather D; Rees, Christiaan A; Hill, Jane E

    2016-11-21

    Pseudomonas aeruginosa is a nearly ubiquitous Gram-negative organism, well known to occupy a multitude of environmental niches and cause human infections at a variety of bodily sites, due to its metabolic flexibility, secondary to extensive genetic heterogeneity at the species level. Because of its dynamic metabolism and clinical importance, we sought to perform a comparative analysis on the volatile metabolome (the 'volatilome') produced by P. aeruginosa clinical isolates. In this study, we analyzed the headspace volatile molecules of 24 P. aeruginosa clinical isolates grown in vitro, using 2D gas chromatography time-of-flight mass spectrometry (GC  ×  GC-TOFMS). We identified 391 non-redundant compounds that we associate with the growth and metabolism of P. aeruginosa (the 'pan-volatilome'). Of these, 70 were produced by all 24 isolates (the 'core volatilome'), 52 by only a single isolate, and the remaining 269 volatile molecules by a subset. Sixty-five of the detected compounds could be assigned putative compound identifications, of which 43 had not previously been associated with P. aeruginosa. Using the accessory volatile molecules, we determined the inter-strain variation in the metabolomes of these isolates, clustering strains by their metabotypes. Assessing the extent of metabolomic diversity in P. aeruginosa through an analysis of the volatile molecules that it produces is a critical next step in the identification of novel diagnostic or prognostic biomarkers.

  3. Antibiotic resistance among Helicobacter pylori clinical isolates in Lima, Peru

    PubMed Central

    Boehnke, Kevin F; Valdivieso, Manuel; Bussalleu, Alejandro; Sexton, Rachael; Thompson, Kathryn C; Osorio, Soledad; Reyes, Italo Novoa; Crowley, John J; Baker, Laurence H; Xi, Chuanwu

    2017-01-01

    Objectives Gastric carcinoma is the most common cancer and cause of cancer mortality in Peru. Helicobacter pylori, a bacterium that colonizes the human stomach, is a Group 1 carcinogen due to its causal relationship to gastric carcinoma. While eradication of H. pylori can help prevent gastric cancer, characterizing regional antibiotic resistance patterns is necessary to determine targeted treatment for each region. Thus, we examined primary antibiotic resistance in clinical isolates of H. pylori in Lima, Peru. Materials and methods H. pylori strains were isolated from gastric biopsies of patients with histologically proven H. pylori infection. Primary antibiotic resistance among isolates was examined using E-test strips. Isolates were examined for the presence of the cagA pathogenicity island and the vacA m1/m2 alleles via polymerase chain reaction. Results Seventy-six isolates were recovered from gastric biopsies. Clinical isolates showed evidence of antibiotic resistance to 1 (27.6%, n=21/76), 2 (28.9%, n=22/76), or ≥3 antibiotics (40.8%). Of 76 isolates, eight (10.5%) were resistant to amoxicillin and clarithromycin, which are part of the standard triple therapy for H. pylori infection. No trends were seen between the presence of cagA, vacA m1, or vacA m2 and antibiotic resistance. Conclusion The rate of antibiotic resistance among H. pylori isolates in Lima, Peru, is higher than expected and presents cause for concern. To develop more targeted eradication therapies for H. pylori in Peru, more research is needed to better characterize antibiotic resistance among a larger number of clinical isolates prospectively. PMID:28331349

  4. Molecular mechanism of fluoroquinolones resistance in Mycoplasma hominis clinical isolates.

    PubMed

    Meng, Dong-Ya; Sun, Chang-Jian; Yu, Jing-Bo; Ma, Jun; Xue, Wen-Cheng

    2014-01-01

    To evaluate the molecular mechanism of fluoroquinolones resistance in Mycoplasma hominis (MH) clinical strains isolated from urogenital specimens. 15 MH clinical isolates with different phenotypes of resistance to fluoroquinolones antibiotics were screened for mutations in the quinolone resistance-determining regions (QRDRs) of DNA gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE) in comparison with the reference strain PG21, which is susceptible to fluoroquinolones antibiotics. 15 MH isolates with three kinds of quinolone resistance phenotypes were obtained. Thirteen out of these quinolone-resistant isolates were found to carry nucleotide substitutions in either gyrA or parC. There were no alterations in gyrB and no mutations were found in the isolates with a phenotype of resistance to Ofloxacin (OFX), intermediate resistant to Levofloxacin (LVX) and Sparfloxacin (SFX), and those susceptible to all three tested antibiotics. The molecular mechanism of fluoroquinolone resistance in clinical isolates of MH was reported in this study. The single amino acid mutation in ParC of MH may relate to the resistance to OFX and LVX and the high-level resistance to fluoroquinolones for MH is likely associated with mutations in both DNA gyrase and the ParC subunit of topoisomerase IV.

  5. Microbiological features of KPC-producing Enterobacter isolates identified in a U.S. hospital system.

    PubMed

    Ahn, Chulsoo; Syed, Alveena; Hu, Fupin; O'Hara, Jessica A; Rivera, Jesabel I; Doi, Yohei

    2014-10-01

    Microbiological data regarding Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacter spp. are scarce. In this study, 11 unique KPC-producing Enterobacter isolates were identified among 44 ertapenem-nonsusceptible Enterobacter isolates collected between 2009 and 2013 at a hospital system in Western Pennsylvania. All cases were healthcare-associated and occurred in medically complex patients. While pulsed-field gel electrophoresis showed diverse restriction patterns overall, multilocus sequence typing identified Enterobacter cloacae isolates with sequence types 93 and 171 from 2 hospitals each. The levels of carbapenem minimum inhibitory concentrations were highly variable. All isolates remained susceptible to colistin and tigecycline, and the majority, to amikacin and doxycycline. A blaKPC-carrying IncN plasmid conferring trimethoprim-sulfamethoxazole resistance was identified in 3 of the isolates. Spread of blaKPC in Enterobacter spp. appears to be due to a combination of plasmid-mediated and clonal processes.

  6. Microbiological Features of KPC-Producing Enterobacter Isolates Identified in a U.S. Hospital System

    PubMed Central

    Ahn, Chulsoo; Syed, Alveena; Hu, Fupin; O’Hara, Jessica A.; Rivera, Jesabel I.; Doi, Yohei

    2014-01-01

    Microbiological data regarding KPC-producing Enterobacter spp. are scarce. In this study, 11 unique KPC-producing Enterobacter isolates were identified among 44 ertapenem-non-susceptible Enterobacter isolates collected between 2009 and 2013 at a hospital system in Western Pennsylvania. All cases were healthcare-associated and occurred in medically complex patients. While pulsed-field gel electrophoresis (PFGE) showed diverse restriction patterns overall, multilocus sequence typing (MLST) identified Enterobacter cloacae isolates with sequence types (STs) 93 and 171 from two hospitals each. The levels of carbapenem minimum inhibitory concentrations were highly variable. All isolates remained susceptible to colistin, tigecycline, and the majority to amikacin and doxycycline. A blaKPC-carrying IncN plasmid conferring trimethoprim-sulfamethoxazole resistance was identified in three of the isolates. Spread of blaKPC in Enterobacter spp. appears to be due to a combination of plasmid-mediated and clonal processes. PMID:25053203

  7. Nocardia isolation from clinical samples with the paraffin baiting technique

    PubMed Central

    Bafghi, Mehdi Fatahi; Heidarieh, Parvin; Soori, Tahereh; Saber, Sasan; Meysamie, Alipasha; Gheitoli, Khavar; Habibnia, Shadi; Rasouli Nasab, Masoumeh; Eshraghi, Seyyed Saeed

    2015-01-01

    Background The genus Nocardia is a cause of infection in the lungs, skin, brain, cerebrospinal fluid, eyes, joints and kidneys. Nocardia isolation from polymicrobial specimens is difficult due to its slow growth. Several methods have been reported for Nocardia isolation from clinical samples. In the current study, we used three methods: paraffin baiting technique, paraffin agar, and conventional media for Nocardia isolation from various clinical specimens from Iranian patients. Methods In this study, we examined 517 samples from various clinical specimens such as: sputum of patients with suspected tuberculosis, bronchoalveolar lavage, sputum of patients with cystic fibrosis, tracheal aspirate, cutaneous and subcutaneous abscesses, cerebrospinal fluid, dental abscess, mycetoma, wound, bone marrow biopsy, and gastric lavage. All collected specimens were cultured on carbon-free broth tubes (paraffin baiting technique), paraffin agar, Sabouraud dextrose agar, and Sabouraud dextrose agar with cycloheximide and were incubated at 35°C for one month. Results Seven Nocardia spp. were isolated with paraffin baiting technique, compared with 5 positive results with the paraffin agar technique and 3 positive results with Sabouraud dextrose agar with and without cycloheximide. The prevalence of nocardial infections in our specimens was 5.28%. Conclusion In the present study, the use of the paraffin baiting technique appeared to be more effective than other methods for Nocardia isolation from various clinical specimens. PMID:25763363

  8. Isolation, Characterization and Selection of Avermectin-Producing Streptomyces avermitilis Strains From Soil Samples

    PubMed Central

    Siddique, Samia; Syed, Quratulain; Adnan, Ahmad; Qureshi, Fahim Ashraf

    2014-01-01

    Background: Streptomyces avermitilis, belonging to Actinomycetes, is specialized for production of avermectin, used as an anthelmintic and insecticidal agent. It is mostly found in soil and its isolation is very crucial for medically important avermectin production. Objectives: In the present study, 10 bacterial isolates lacking antimicrobial activities were isolated from the soil samples collected from different areas of Lahore, Pakistan. Materials and Methods: Three distinctive localities of Lahore were opted for soil assortment to isolate S. avermitilis. About 50 isolates of Streptomyces species were attained through selective prescreening procedures. All of these isolates were studied for production of the secondary metabolite, avermectin. Different test like soluble pigment color and melanin formation were used for identification. Biochemical characterizations of those isolates closely resembling the control in morphological characteristics, soluble pigment color and melanin formation tests were performed. Results: The 10 selected isolates were identified as the avermectin-producing strain by fermentation and characterized on ISP2 medium for aerial and reverse side mycelia color, soluble pigment color and melanin formation, in comparison with S. avermitilis DSM 41445. The best avermectin-producing isolate S1-C (10.15 mg/L) showed similar result as S. avermitilis DSM 41445, when subjected for culture characteristics analysis in different media along with biochemical characterization. Conclusions: From the results, it was concluded that agricultural lands around Pakistan Council of Scientific and Industrial Research (PCSIR) Campus Lahore were rich sources of industrially important Streptomyces, especially S. avermitilis. PMID:25371798

  9. Diversity of enterobacteria including β-lactamase producing isolates associated with the Spanish slug (Arion vulgaris).

    PubMed

    Stalder, Gabrielle L; Loncaric, Igor; Walzer, Chris

    2014-05-01

    The aim of this study was to determine diversity in members of the family Enterobacteriaceae including the beta-lactamase producing isolates associated with the Spanish slug (Arion vulgaris). 81 isolates, each representing a distinct colonial morphotype, were obtained from fecal samples of Spanish slugs and analyzed. Genetically heterogeneous or similar groups were assessed among the isolates by enterobacterial repetitive intergenic consensus (ERIC)-PCR and further characterized by 16S rDNA sequence analysis. Representative strains were allocated to the genera Citrobacter, Raoultella, Escherichia, Klebsiella, Kluyvera, and Buttiauxella. Fifteen isolates, most closely related to Citrobacter freundii and Escherichia coli, displayed an AmpC phenotype, one E. coli isolate showed an ESBL phenotype. These isolates were phenotypically and genotypically characterized by their antimicrobial resistance pattern. Phylogenetic background and multi-locus sequence typing (MLST) of the E. coli isolates were determined. The multi-drug resistant TEM-1 E. coli positive isolate belongs to the phylogenetic group A and ST10. The CMY-2 positive E. coli isolate belongs to the phylogenetic group D and ST117. Our results show that the common garden slug represents an important potential vector of β-lactamase producing Enterobacteriaceae.

  10. Biofilm-Forming Abilities of Shiga Toxin-Producing Escherichia coli Isolates Associated with Human Infections

    PubMed Central

    Vogeleer, Philippe; Tremblay, Yannick D. N.; Jubelin, Grégory; Jacques, Mario

    2015-01-01

    Forming biofilms may be a survival strategy of Shiga toxin-producing Escherichia coli to enable it to persist in the environment and the food industry. Here, we evaluate and characterize the biofilm-forming ability of 39 isolates of Shiga toxin-producing Escherichia coli isolates recovered from human infection and belonging to seropathotypes A, B, or C. The presence and/or production of biofilm factors such as curli, cellulose, autotransporter, and fimbriae were investigated. The polymeric matrix of these biofilms was analyzed by confocal microscopy and by enzymatic digestion. Cell viability and matrix integrity were examined after sanitizer treatments. Isolates of the seropathotype A (O157:H7 and O157:NM), which have the highest relative incidence of human infection, had a greater ability to form biofilms than isolates of seropathotype B or C. Seropathotype A isolates were unique in their ability to produce cellulose and poly-N-acetylglucosamine. The integrity of the biofilms was dependent on proteins. Two autotransporter genes, ehaB and espP, and two fimbrial genes, z1538 and lpf2, were identified as potential genetic determinants for biofilm formation. Interestingly, the ability of several isolates from seropathotype A to form biofilms was associated with their ability to agglutinate yeast in a mannose-independent manner. We consider this an unidentified biofilm-associated factor produced by those isolates. Treatment with sanitizers reduced the viability of Shiga toxin-producing Escherichia coli but did not completely remove the biofilm matrix. Overall, our data indicate that biofilm formation could contribute to the persistence of Shiga toxin-producing Escherichia coli and specifically seropathotype A isolates in the environment. PMID:26712549

  11. Biofilm-Forming Abilities of Shiga Toxin-Producing Escherichia coli Isolates Associated with Human Infections.

    PubMed

    Vogeleer, Philippe; Tremblay, Yannick D N; Jubelin, Grégory; Jacques, Mario; Harel, Josée

    2015-12-28

    Forming biofilms may be a survival strategy of Shiga toxin-producing Escherichia coli to enable it to persist in the environment and the food industry. Here, we evaluate and characterize the biofilm-forming ability of 39 isolates of Shiga toxin-producing Escherichia coli isolates recovered from human infection and belonging to seropathotypes A, B, or C. The presence and/or production of biofilm factors such as curli, cellulose, autotransporter, and fimbriae were investigated. The polymeric matrix of these biofilms was analyzed by confocal microscopy and by enzymatic digestion. Cell viability and matrix integrity were examined after sanitizer treatments. Isolates of the seropathotype A (O157:H7 and O157:NM), which have the highest relative incidence of human infection, had a greater ability to form biofilms than isolates of seropathotype B or C. Seropathotype A isolates were unique in their ability to produce cellulose and poly-N-acetylglucosamine. The integrity of the biofilms was dependent on proteins. Two autotransporter genes, ehaB and espP, and two fimbrial genes, z1538 and lpf2, were identified as potential genetic determinants for biofilm formation. Interestingly, the ability of several isolates from seropathotype A to form biofilms was associated with their ability to agglutinate yeast in a mannose-independent manner. We consider this an unidentified biofilm-associated factor produced by those isolates. Treatment with sanitizers reduced the viability of Shiga toxin-producing Escherichia coli but did not completely remove the biofilm matrix. Overall, our data indicate that biofilm formation could contribute to the persistence of Shiga toxin-producing Escherichia coli and specifically seropathotype A isolates in the environment.

  12. Multi-Locus Analysis of a Citreoviridin-Producing Isolate Previously Identified as Penicillium NRRL 13013

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cole et al (1981) reported a citreoviridin-producing isolate of Penicillium charlesii (NRRL 13013) from molded pecans. Wicklow later identified it as a variant of Penicillium citreoviride, noting that it produced sclerotia, although the species as a whole is not known to do so. We sequenced the IT...

  13. Draft Genome Sequence of the Antibiotic-Producing Epiphytic Isolate Pantoea ananatis BRT175

    PubMed Central

    Smith, Derek D. N.; Kirzinger, Morgan W. B.

    2013-01-01

    Pantoea is a member of the Enterobacteriaceae, whose members have been shown to produce novel antibiotics. Here, we report the 4.8-Mb genome sequence of Pantoea ananatis strain BRT175, an epiphytic isolate from strawberries that produces an antibiotic that is effective against the fire blight pathogen, Erwinia amylovora. PMID:24201193

  14. Antibacterial Activity of Some Plant Extracts Against Extended- Spectrum Beta-Lactamase Producing Escherichia coli Isolates

    PubMed Central

    Saeidi, Saeide; Amini Boroujeni, Negar; Ahmadi, Hassan; Hassanshahian, Mehdi

    2015-01-01

    Background: The extended-spectrum beta-lactamase (ESBL) -producing Escherichia coli isolates make many serious infections, especially urinary tract infections. Objectives: The purpose of this study was to determine the antibacterial activities of some natural plant extracts against ESBL-producing E. coli isolates, which harbor the TEM gene in urine samples of the patients who have urinary tract infections. Materials and Methods: Evaluation has to be exactly determined for both methods of disk diffusion test and polymerase chain reaction (PCR), separately. We evaluated 120 strains of E. coli isolates from the urine culture of the patients in Boo-Ali Hospital (Zahedan, south-eastern Iran) who were suffering from urinary tract infections. The ESBL-producing E. coli isolates were evaluated by disk diffusion test and PCR through TEM gene detection. The minimal inhibitory concentration (MIC) of commonly used antibiotics including ceftazidime, ceftriaxon, amikacin, gentamicin and ciprofloxacin along with the MIC of the alcoholic extract of different natural plants including Myrtus communis L (Myrtaceae), Amaranthus retraflexus (Amaranthaceae), Cyminum cuminum L (Apiaceae), Marrubium vulgare (Laminaceae) and Peganum. harmala (Zygrophyllaceae) against the ESBL-producing E. coli isolates, which harbor the TEM genes, were determined using the microdulition method. Results: Results of this study showed that in disk diffusion method, 80 samples of E. coli produced ESBLs. In PCR method, the TEM gene distribution in the isolated ESBL-producing organisms was 50 (41.6%). Amikacin was the most effective anti-bacterial agent and ciprofloxacin was the least effective against E. coli isolates. All the natural plant extracts mentioned above, especially P. harmala, were effective against the selected isolates of ESBL-producing E. coli. The most frequent ESBL rate producing E. coli isolates (32 out of 50) had MIC of 2.5 mg/mL in ethanol extract of P. harmala. Conclusions: The alcoholic

  15. Enzyme polymorphism, prodigiosin production, and plasmid fingerprints in clinical and naturally occurring isolates of Serratia marcescens.

    PubMed Central

    Gargallo-Viola, D

    1989-01-01

    Enzyme polymorphism and genetic relationship among 99 Serratia marcescens isolates obtained from clinical and environmental sources were determined by analysis of electromorphs in nine enzyme loci encoded by chromosomal genes. Seven of the loci were polymorphic, and 33 distinctive electrophoretic types (ETs) representing multilocus genotypes were identified. Cluster analysis, based on the proportion of mismatches between multilocus genotypes, revealed two clearly differentiated groups of ETs in S. marcescens. One was represented exclusively by isolates with nonchromogenic biotypes recovered almost entirely (97.3%) from clinical samples. The other group comprised all isolates characterized by the production of prodigiosin or by belonging to a chromogenic biotype. Absolute correlation was found between the ability to produce prodigiosin and the absence of plasmids. In contrast, 24% of the nonchromogenic isolates contained plasmids. Results obtained by analysis of multilocus genotypes were related to those obtained by biotyping and plasmid fingerprinting. However, more groups could be distinguished by analysis of ETs than by biotyping. Plasmid fingerprinting was a limited typing system because many isolates lacked plasmids. Although the results of this study did not permit a definitive correlation between ETs and pathogenicity of the isolates, more detailed studies of these groups will help to understand the different clinical significances of the nonchromogenic and chromogenic isolates of S. marcescens. PMID:2663918

  16. RESPONSES OF OYSTER (CRASSOSTREA VIRGINICA) HEMOCYTES TO NONPATHOGENIC AND CLINICAL ISOLATES OF VIBRIO PARAHAEMOLYTICUS

    EPA Science Inventory

    Bacterial uptake by oysters (Crassostrea virginica) and bactericidal activity of oyster hemocytes were studied using four environmental isolates and three clinical isolates of Vibrio parahaemolyticus. Clinical isolates (2030, 2062, 2107) were obtained from gastroenteritis patien...

  17. Biofilm formation and genetic diversity of Salmonella isolates recovered from clinical, food, poultry and environmental sources.

    PubMed

    Nair, Amruta; Rawool, Deepak B; Doijad, Swapnil; Poharkar, Krupali; Mohan, Vysakh; Barbuddhe, Sukhadeo B; Kolhe, Rahul; Kurkure, Nitin V; Kumar, Ashok; Malik, S V S; Balasaravanan, T

    2015-12-01

    In the present study, Salmonella isolates (n=40) recovered from clinical, food, poultry and environmental sources were characterized for serotype identification, genetic diversity and biofilm formation capability. Serotype identification using multiplex PCR assay revealed six isolates to be Salmonella Typhimurium, 14 as Salmonella Enteritidis, 11 as Salmonella Typhi, and the remaining nine isolates unidentified were considered as other Salmonella spp. Most of the Salmonella isolates (85%) produced biofilm on polystyrene surfaces as assessed by microtitre plate assay. About 67.5% isolates were weak biofilm producers and 17.5% were moderate biofilm producers. There was no significant difference in biofilm-forming ability among the Salmonella isolates recovered from different geographical regions or different sources. Among the genetic methods, Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR revealed greater discriminatory power (DI, 0.943) followed by pulsed field gel electrophoresis (PFGE) (DI, 0.899) and random amplification of polymorphic DNA (RAPD) PCR (DI, 0.873). However, composite analysis revealed the highest discrimination index (0.957). Greater discrimination of S. Typhimurium and S. Typhi was achieved using PFGE, while ERIC PCR was better for S. Enteritidis and other Salmonella serotypes. A strong positive correlation (r=0.992) was observed between biofilm formation trait and clustered Salmonella isolates in composite genetic analysis.

  18. Clonality and Resistome Analysis of KPC-Producing Klebsiella pneumoniae Strain Isolated in Korea Using Whole Genome Sequencing

    PubMed Central

    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 blaKPC-2, blaSHV-11, blaTEM-169, and blaOXA-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. PMID:25105122

  19. 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.

  20. Two copies of blaNDM-1 gene are present in NDM-1 producing Pseudomonas aeruginosa isolates from Serbia.

    PubMed

    Jovčić, Branko; Lepšanović, Zorica; Begović, Jelena; Filipić, Brankica; Kojić, Milan

    2014-03-01

    New Delhi metallo-β-lactamase producing Pseudomonas aeruginosa isolates are of special interest since P. aeruginosa is a major cause of nosocomial infections, the treatment of which could now be jeopardized, especially in developing countries. Six additional NDM-1 positive P. aeruginosa clinical isolates belonging to two different genotypes were shown to be plasmid-free. PFGE-hybridization experiments revealed the chromosomal location of the blaNDM-1 gene. Restriction analysis and hybridization revealed that two copies of the blaNDM-1 gene are present in the genomes of all tested isolates, as in previously characterized P. aeruginosa MMA83. Moreover, it was shown that increasing imipenem concentration did not have the effect on copy number of the blaNDM-1 gene in the genome of P. aeruginosa MMA83.

  1. Whole genome sequencing of clinical isolates of Giardia lamblia.

    PubMed

    Hanevik, K; Bakken, R; Brattbakk, H R; Saghaug, C S; Langeland, N

    2015-02-01

    Clinical isolates from protozoan parasites such as Giardia lamblia are at present practically impossible to culture. By using simple cyst purification methods, we show that Giardia whole genome sequencing of clinical stool samples is possible. Immunomagnetic separation after sucrose gradient flotation gave superior results compared to sucrose gradient flotation alone. The method enables detailed analysis of a wide range of genes of interest for genotyping, virulence and drug resistance.

  2. Prevalence and Characteristics of Salmonella Serotypes Isolated from Fresh Produce Marketed in the United States.

    PubMed

    Reddy, Shanker P; Wang, Hua; Adams, Jennifer K; Feng, Peter C H

    2016-01-01

    Salmonella continues to rank as one of the most costly foodborne pathogens, and more illnesses are now associated with the consumption of fresh produce. The U.S. Department of Agriculture Microbiological Data Program (MDP) sampled select commodities of fresh fruit and vegetables and tested them for Salmonella, pathogenic Escherichia coli, and Listeria. The Salmonella strains isolated were further characterized by serotype, antimicrobial resistance, and pulsed-field gel electrophoresis profile. This article summarizes the Salmonella data collected by the MDP between 2002 and 2012. The results show that the rates of Salmonella prevalence ranged from absent to 0.34% in cilantro. A total of 152 isolates consisting of over 50 different serotypes were isolated from the various produce types, and the top five were Salmonella enterica serotype Cubana, S. enterica subspecies arizonae (subsp. IIIa) and diarizonae (subsp. IIIb), and S. enterica serotypes Newport, Javiana, and Infantis. Among these, Salmonella serotypes Newport and Javiana are also listed among the top five Salmonella serotypes that caused most foodborne outbreaks. Other serotypes that are frequent causes of infection, such as S. enterica serotypes Typhimurium and Enteritidis, were also found in fresh produce but were not prevalent. About 25% of the MDP samples were imported produce, including 65% of green onions, 44% of tomatoes, 42% of hot peppers, and 41% of cantaloupes. However, imported produce did not show higher numbers of Salmonella-positive samples, and in some products, like cilantro, all of the Salmonella isolates were from domestic samples. About 6.5% of the Salmonella isolates were resistant to the antimicrobial compounds tested, but no single commodity or serotype was found to be the most common carrier of resistant strains or of resistance. The pulsed-field gel electrophoresis profiles of the produce isolates showed similarities with Salmonella isolates from meat samples and from outbreaks, but

  3. Isolation, characterization, and diversity of novel radiotolerant carotenoid-producing bacteria.

    PubMed

    Asker, Dalal; Awad, Tarek S; Beppu, Teruhiko; Ueda, Kenji

    2012-01-01

    Carotenoids are natural pigments that exhibit many biological functions, such as antioxidants (i.e., promote oxidative stress resistance), membrane stabilizers, and precursors for vitamin A. The link between these biological activities and many health benefits (e.g., anticarcinogenic activity, prevention of chronic diseases, etc.) has raised the interest of several industrial sectors, especially in the cosmetics and pharmaceutical industries. The use of microorganisms in biotechnology to produce carotenoids is favorable by consumer and can help meet the growing demand for these bioactive compounds in the food, feed, and pharmaceutical industries. This methodological chapter details the development of a rapid and selective screening method for isolation and identification of carotenoid-producing microorganisms based on UV treatment, sequencing analysis of 16S rRNA genes, and carotenoids' analysis using rapid and effective High-Performance Liquid Chromatography-Diodearray-MS methods. The results of a comprehensive 16S rRNA gene-based phylogenetic analysis revealed a diversity of carotenoid-producing microorganisms (104 isolates) that were isolated at a high frequency from water samples collected at Misasa (Tottori, Japan), a region known for its high natural radioactivity content. These carotenoid-producing isolates were classified into 38 different species belonging to 7 bacterial classes (Flavobacteria, Sphingobacteria, α-Proteobacteria, γ-Proteobacteria, Deinococci, Actinobacteria, and Bacilli). The carotenoids produced by the isolates were zeaxanthin (6 strains), dihydroxyastaxanthin (24 strains), astaxanthin (27 strains), canthaxanthin (10 strains), and unidentified molecular species that were produced by the isolates related to Deinococcus, Exiguobacterium, and Flectobacillus. Here, we describe the methods used to isolate and classify these microorganisms.

  4. Asperger syndrome, violent thoughts and clinically isolated syndrome.

    PubMed

    Vanderbruggen, N; Van Geit, N; Bissay, V; Zeeuws, D; Santermans, L; Baeken, C

    2010-12-01

    A young man, 23 years old, with a clinically isolated syndrome (CIS), presented violent thoughts during a neurological consultation. He was diagnosed with Asperger Syndrome based on a psychiatric and (neuro)psychological examination. Possible risk factors for acting-out and the implications for treatment, if CIS would evolve to MS, are discussed based on a review of the literature.

  5. Complete genome sequence of Providencia stuartii clinical isolate MRSN 2154.

    PubMed

    Clifford, Robert J; Hang, Jun; Riley, Matthew C; Onmus-Leone, Fatma; Kuschner, Robert A; Lesho, Emil P; Waterman, Paige E

    2012-07-01

    Here we present the complete genome sequence of Providencia stuartii MRSN 2154, isolated from an Afghan national. P. stuartii is a Gram-negative bacillus capable of causing infections in a wide variety of human tissues. Because Providencia readily acquires plasmids bearing drug resistance loci, it is of growing clinical significance.

  6. Draft Genome Sequence of Tannerella forsythia Clinical Isolate 9610

    PubMed Central

    Hanson-Drury, Sesha; Liu, Quanhui; Vo, Anh T.; Kim, Michelle; Watling, Michael; Bumgarner, Roger S.

    2017-01-01

    ABSTRACT We present here the draft genome sequence of Tannerella forsythia 9610, a clinical isolate obtained from a periodontitis patient. The genome is composed of 79 scaffolds with 82 contigs, for a length of 3,201,941 bp and a G+C of 47.3%. PMID:28336586

  7. Activity of coumermycin against clinical isolates of staphylococci.

    PubMed Central

    Guillemin, M N; Miles, H M; McDonald, M I

    1986-01-01

    Staphylococci, particularly methicillin-resistant strains of Staphylococcus aureus, are major nosocomial pathogens in large hospitals in eastern Australia. At present vancomycin is the drug of choice for the treatment of life-threatening methicillin-resistant S. aureus infections. A possible alternative drug is coumermycin, a bis-hydroxy coumarin which inhibits DNA gyrase. Coumermycin activity was determined against clinical isolates from the Royal Melbourne Hospital. MICs of 639 staphylococcal isolates were determined by agar dilution. MICs and MBCs of 100 staphylococcal isolates were also determined by microdilution methods. The results showed that coumermycin was bactericidal, with MBCs of less than or equal to 4 micrograms/ml against all isolates tested. The results indicate that coumermycin is a potential alternative to vancomycin in the treatment of severe staphylococcal infections. PMID:3707109

  8. Characterization of multiple NDM-1-producing Enterobacteriaceae isolates from the same patient.

    PubMed

    Tijet, Nathalie; Richardson, David; MacMullin, Gregory; Patel, Samir N; Melano, Roberto G

    2015-01-01

    A male patient was admitted to a community hospital in Ontario, Canada, with an infected sacral ulcer after returning from India, where he was hospitalized. Carbapenem-resistant Escherichia coli (isolated from blood cultures), Enterobacter cloacae, and Providencia stuartii (from urine samples), all positive for bla(NDM-1), were recovered. Comparative NDM-1 plasmid analysis suggests both lateral plasmid transfer and independent acquisition of the bla(NDM-1) gene in these clinical isolates.

  9. Antibiotic resistance-mediated isolation of scaffold-specific natural product producers.

    PubMed

    Thaker, Maulik N; Waglechner, Nicholas; Wright, Gerry D

    2014-01-01

    For over half a century, actinomycetes have served as the most promising source of novel antibacterial scaffolds. However, over the years, there has been a decline in the discovery of new antibiotics from actinomycetes. This is partly due to the use of standard screening methods and platforms that result in the re-discovery of the same molecules. Thus, according to current estimates, the discovery of a new antibacterial requires screening of tens to hundreds of thousands of bacterial strains. We have devised a resistance-based antibacterial discovery platform by harnessing the innate self-protection mechanism of antibiotic producers. This protocol provides a detailed method for isolation of scaffold-specific antibacterial producers by isolating strains in the presence of a selective antibiotic. As a specific example, we describe isolation of glycopeptide antibiotic (GPA) producers from soil actinomycetes, using vancomycin as the antibiotic resistance filter. However, the protocol can be adapted to isolate diverse producers from various sources producing different scaffolds, by selecting an appropriate antibiotic as a screening filter. The protocol provides a solution for two major bottlenecks that impede the new drug discovery pipeline: low hit frequency and re-discovery of known molecules. The entire protocol, from soil collection to identification of putative antibacterial producers, takes about 6 weeks to complete.

  10. Candida species biofilm and Candida albicans ALS3 polymorphisms in clinical isolates.

    PubMed

    Bruder-Nascimento, Ariane; Camargo, Carlos Henrique; Mondelli, Alessandro Lia; Sugizaki, Maria Fátima; Sadatsune, Terue; Bagagli, Eduardo

    2014-01-01

    Over the last decades, there have been important changes in the epidemiology of Candida infections. In recent years, Candida species have emerged as important causes of invasive infections mainly among immunocompromised patients. This study analyzed Candida spp. isolates and compared the frequency and biofilm production of different species among the different sources of isolation: blood, urine, vulvovaginal secretions and peritoneal dialysis fluid. Biofilm production was quantified in 327 Candida isolates obtained from patients attended at a Brazilian tertiary public hospital (Botucatu, Sao Paulo). C. albicans ALS3 gene polymorphism was also evaluated by determining the number of repeated motifs in the central domain. Of the 198 total biofilm-positive isolates, 72 and 126 were considered as low and high biofilm producers, respectively. Biofilm production by C. albicans was significantly lower than that by non-albicans isolates and was most frequently observed in C. tropicalis. Biofilm production was more frequent among bloodstream isolates than other clinical sources, in urine, the isolates displayed a peculiar distribution by presenting two distinct peaks, one containing biofilm-negative isolates and the other containing isolates with intense biofilm production. The numbers of tandem-repeat copies per allele were not associated with biofilm production, suggesting the evolvement of other genetic determinants.

  11. Diverse Exopolysaccharide Producing Bacteria Isolated from Milled Sugarcane: Implications for Cane Spoilage and Sucrose Yield.

    PubMed

    Hector, Stanton; Willard, Kyle; Bauer, Rolene; Mulako, Inonge; Slabbert, Etienne; Kossmann, Jens; George, Gavin M

    2015-01-01

    Bacterial deterioration of sugarcane during harvesting and processing is correlated with significant loss of sucrose yield and the accumulation of bacterial polysaccharides. Dextran, a homoglucan produced by Leuconostoc mesenteroides, has been cited as the primary polysaccharide associated with sugarcane deterioration. A culture-based approach was used to isolate extracellular polysaccharide (EPS) producing bacterial strains from milled sugarcane stalks. Ribosomal RNA sequencing analysis grouped 25 isolates into 4 genera. This study identified 2 bacterial genera not previously associated with EPS production or sucrose degradation. All isolates produced polysaccharide when grown in the presence of sucrose. Monosaccharide analysis of purified polymers by Gas Chromatography revealed 17 EPSs consisting solely of glucose (homoglucans), while the remainder contained traces of mannose or fructose. Dextranase treatment of polysaccharides yielded full digestion profiles for only 11 extracts. Incomplete hydrolysis profiles of the remaining polysaccharides suggest the release of longer oligosaccharides which may interfere with sucrose crystal formation.

  12. First detection of OXA-24 carbapenemase-producing Acinetobacter baumannii isolates in Bulgaria.

    PubMed

    Todorova, Bozhana; Velinov, Tzvetan; Ivanov, Ivan; Dobreva, Elina; Kantardjiev, Todor

    2014-04-01

    This report describes the first identification of OXA-24 carbapenemase-producing Acinetobacter baumannii isolates from Bulgaria. According to national surveillance data A. baumannii along with Pseudomonas aeruginosa are the most troublesome microorganisms in hospital environment with high rates of acquired carbapenem resistance. In the present study real-time multiplex PCR was performed to identify the most common carbapenemase genes in 15 non-duplicate carbapenem-resistant A. baumannii isolates collected in 2012. The results showed lack of KPC, GES, VIM, IMP-type enzymes. Four A. baumannii isolates tested positive by PCR for the acquired OXA-24 together with the intrinsic OXA-51 carbapenemase. OXA-24 and OXA-23 were determined as co-existent in one isolate. Two isolates were identified with OXA-23 in addition to the OXA-51 carbapenemase.

  13. NDM-1- and OXA-163-producing Klebsiella pneumoniae isolates in Cairo, Egypt, 2012.

    PubMed

    Abdelaziz, Mohammed O; Bonura, Celestino; Aleo, Aurora; Fasciana, Teresa; Mammina, Caterina

    2013-12-01

    Here we describe carbapenem resistance determinants in two Klebsiella pneumoniae isolates recovered from two hospitalised patients in the same intensive care unit of a cancer hospital in Cairo, Egypt. PCR and sequencing were used to detect and characterise β-lactamase genes. Clonal relationships between the isolates were analysed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The first K. pneumoniae isolate carried the blaNDM-1 gene and the second isolate carried the blaOXA-163 gene. Both isolates co-expressed the extended-spectrum β-lactamase CTX-M-15. The two isolates belonged to different sequence types (STs), ST11 and ST16, respectively. No history of travel was established for the two patients. The first identification of NDM-1-producing K. pneumoniae in Egypt adds further evidence to the spread of NDM-1-producing Gram-negative micro-organisms in North Africa. The additional detection of blaOXA-163 in a K. pneumoniae isolate confirms its endemic presence in a critical healthcare setting of this geographic area.

  14. Isolation of palm oil-utilising, polyhydroxyalkanoate (PHA)-producing bacteria by an enrichment technique.

    PubMed

    Alias, Zazali; Tan, Irene K P

    2005-07-01

    In early attempts to isolate palm oil-utilising bacteria from palm oil mill effluent (POME), diluted liquid samples of POME were spread on agar containing POME as primary nutrient. 45 purified colonies were screened for intracellular lipids by staining with Sudan Black B. Of these, 10 isolates were positively stained. The latter were grown in a nitrogen-limiting medium with palm olein (a triglyceride) or saponified palm olein (salts of fatty acids) as carbon source. None of the isolates grew in the palm olein medium but all grew well in the saponified palm olein medium. Of the latter however, only one isolate was positively stained with Nile Blue A, indicating the presence of PHA. This method did not successfully generate bacterial isolates which could metabolise palm olein to produce PHA. An enrichment technique was therefore developed whereby a selective medium was designed. The latter comprised minerals and palm olein (1% w/v) as sole carbon source to which POME (2.5% v/v) was added as the source of bacteria. The culture was incubated with shaking at 30 degrees C for 4 weeks. Out of seven isolates obtained from the selective medium, two isolates, FLP1 and FLP2, could utilise palm olein for growth and production of the homopolyester, poly(3-hydroxybutyrate). FLP1 is gram-negative and is identified (BIOLOG) to have 80% similarity to Burkholderia cepacia. When grown with propionate or valerate, FLP1 produced a copolyester, poly(3-hydroxybutyrate-co-3-hydroxyvalerate).

  15. Active Shiga-Like Toxin Produced by Some Aeromonas spp., Isolated in Mexico City.

    PubMed

    Palma-Martínez, Ingrid; Guerrero-Mandujano, Andrea; Ruiz-Ruiz, Manuel J; Hernández-Cortez, Cecilia; Molina-López, José; Bocanegra-García, Virgilio; Castro-Escarpulli, Graciela

    2016-01-01

    Shiga-like toxins (Stx) represent a group of bacterial toxins involved in human and animal diseases. Stx is produced by enterohemorrhagic Escherichia coli, Shigella dysenteriae type 1, Citrobacter freundii, and Aeromonas spp.; Stx is an important cause of bloody diarrhea and hemolytic uremic syndrome (HUS). The aim of this study was to identify the stx1/stx2 genes in clinical strains and outer membrane vesicles (OMVs) of Aeromonas spp., 66 strains were isolated from children who live in Mexico City, and Stx effects were evaluated in Vero cell cultures. The capacity to express active Stx1 and Stx2 toxins was determined in Vero cell cultures and the concentration of Stx was evaluated by 50% lethal dose (LD50) assays, observing inhibition of damaged cells by specific monoclonal antibodies. The results obtained in this study support the hypothesis that the stx gene is another putative virulence factor of Aeromonas, and since this gene can be transferred horizontally through OMVs this genus should be included as a possible causal agents of gastroenteritis and it should be reported as part of standard health surveillance procedures. Furthermore, these results indicate that the Aeromonas genus might be a potential causative agent of HUS.

  16. Active Shiga-Like Toxin Produced by Some Aeromonas spp., Isolated in Mexico City

    PubMed Central

    Palma-Martínez, Ingrid; Guerrero-Mandujano, Andrea; Ruiz-Ruiz, Manuel J.; Hernández-Cortez, Cecilia; Molina-López, José; Bocanegra-García, Virgilio; Castro-Escarpulli, Graciela

    2016-01-01

    Shiga-like toxins (Stx) represent a group of bacterial toxins involved in human and animal diseases. Stx is produced by enterohemorrhagic Escherichia coli, Shigella dysenteriae type 1, Citrobacter freundii, and Aeromonas spp.; Stx is an important cause of bloody diarrhea and hemolytic uremic syndrome (HUS). The aim of this study was to identify the stx1/stx2 genes in clinical strains and outer membrane vesicles (OMVs) of Aeromonas spp., 66 strains were isolated from children who live in Mexico City, and Stx effects were evaluated in Vero cell cultures. The capacity to express active Stx1 and Stx2 toxins was determined in Vero cell cultures and the concentration of Stx was evaluated by 50% lethal dose (LD50) assays, observing inhibition of damaged cells by specific monoclonal antibodies. The results obtained in this study support the hypothesis that the stx gene is another putative virulence factor of Aeromonas, and since this gene can be transferred horizontally through OMVs this genus should be included as a possible causal agents of gastroenteritis and it should be reported as part of standard health surveillance procedures. Furthermore, these results indicate that the Aeromonas genus might be a potential causative agent of HUS. PMID:27725813

  17. Gymnemagenin-producing endophytic fungus isolated from a medicinal plant Gymnema sylvestre R.Br.

    PubMed

    Parthasarathy, Ramalingam; Sathiyabama, Muthukrishnan

    2014-03-01

    Gymnema sylvestre is a plant containing the triterpenoid gymnemagenin, which is used in the pharmaceutical industry as an antidiabetic agent. The objective of this study was to determine whether endophytic fungi, isolated from G. sylvestre, produce gymnemagenin. We isolated an endophytic fungal strain from the leaves of G. sylvestre which produces gymnemagenin in the medium. The fungus was identified as Penicillium oxalicum based on morphological and molecular methods. The strain had a component with the same TLC Rf value and HPLC retention time as authentic gymnemagenin. The presence of gymnemagenin was further confirmed by FTIR, UV, and (1)H NMR analyses.

  18. Multiclonal expansion of Klebsiella pneumoniae isolates producing-NDM-1 in Rio de Janeiro, Brazil.

    PubMed

    Aires, Caio Augusto Martins; Pereira, Polyana Silva; de Araujo, Carlos Felipe Machado; Chagas, Thiago Pavoni Gomes; Oliveira, Jane Cleide; Buonora, Sibelle Nogueira; Albano, Rodolpho Mattos; Carvalho-Assef, Ana Paula D'Alincourt; Asensi, Marise Dutra

    2017-02-06

    We characterized NDM-1-producing Klebsiella spp. isolates from Rio de Janeiro, Brazil. PCR was applied for resistance and virulence determinants. The genetic context of blaNDM was determined by S1 PFGE and hybridization. The genotyping were performed by PFGE and MLST. Most isolates carried multiple resistance genes and remained susceptible to amikacin, fosfomycin/trometamol, polymyxin B and tigecycline. The spread of NDM-1-producing K. pneumoniae was not associated with a clonal expansion and appears to be associated with Tn3000.

  19. [Marine bacteria producing antibacterial compounds isolated from inter-tidal invertebrates].

    PubMed

    León, Jorge; Liza, Libia; Soto, Isela; Torres, Magali; Orosco, Andrés

    2010-06-01

    Prospective sampling activities of intertidal invertebrates in the Ancon Bay (Lima, Peru) were done in order to select marine bacteria producing antimicrobial substances. The study included the isolation of bacteria in marine agar, in vitro antimicrobial susceptibility testing and electronic microscopic observations. We report the isolation, phenotypical characterization and antimicrobial properties of 10 strains of marine bacteria including the genus Vibrio, Pseudomonas, and Flavobacterium, and the order Actinomycetae that inhibit human pathogens. The results indicate that the marine invertebrates would be sources of bacteria producing antibiotic substances.

  20. Emergence of KPC-2-Producing Pseudomonas aeruginosa Sequence Type 463 Isolates in Hangzhou, China

    PubMed Central

    Hu, Yan-yan; Gu, Dan-xia; Cai, Jia-chang; Zhou, Hong-wei

    2015-01-01

    Thirty-nine Klebsiella pneumoniae carbapenemase (KPC)-producing Pseudomonas aeruginosa isolates, all exhibiting high-level resistance to carbapenems and other β-lactam antibiotics, were isolated in Hangzhou, China. Molecular epidemiology analysis indicated the presence of two dominant clones, namely, clones A and B, both of which belong to sequence type 463 (ST463). A genetic environment analysis demonstrated that both clones harbor an ISKpn8 transposase, blaKPC-2, and an ISKpn6-like transposase. These findings depict the features of clonal expansion and transmission of KPC-2-producing P. aeruginosa strains in Hangzhou, China. PMID:25691651

  1. ISOLATION AND IDENTIFICATION OF AN ENDOPHYTIC FUNGUS PRODUCING PACLITAXEL FROM TAXUS WALLICHIANA VAR MAIREI.

    PubMed

    Zaiyou, Jian; Hongsheng, Wang; Ning, Wang; Li, Meng; Guifang, Xu

    2015-12-01

    The objective of this study was to isolate endophytic fungi producing paclitaxel from yew for the purpose of paclitaxel manufacture. Surface sterilized bark of Taxus wallichiana var. mairei was used as source material and potato dextrose agar culture medium was used in isolation of endophytic fungi. Fungal cultures were extracted with a mixture of chloroform / methanol (1:1, v/v) and the paclitaxel in the extracts was determined and authenticated with LC-MS. An endophytic fungus that produced paclitaxel was identified by ITS rDNA and 26S D1/D2 rDNA sequencing. The results showed that a total of 435 endophytic fungal strains were isolated from T. wallichiana var. mairei and purified. Only one of these strains produced paclitaxel and it belongs to Fusarium. The paclitaxel productivity in whole PDB culture and that in spent culture medium from this strain is 0.0153 mg/L and 0.0119 mg/L respectively. The paclitaxel content in dry mycelium is 0.27 mg/kg. This isolated endophytic fungus produced paclitaxel at a considerable level and shows potentiality as a producing strain for paclitaxel manufacture after strain improvement.

  2. Homogeneity of Danish environmental and clinical isolates of Shewanella algae.

    PubMed

    Vogel, B F; Holt, H M; Gerner-Smidt, P; Bundvad, A; Sogaard, P; Gram, L

    2000-01-01

    Danish isolates of Shewanella algae constituted by whole-cell protein profiling a very homogeneous group, and no clear distinction was seen between strains from the marine environment and strains of clinical origin. Although variation between all strains was observed by ribotyping and random amplified polymorphic DNA analysis, no clonal relationship between infective strains was found. From several patients, clonally identical strains of S. algae were reisolated up to 8 months after the primary isolation, indicating that the same strain may be able to maintain the infection.

  3. Extended-spectrum beta-lactamase-producing bacteria isolated from hematologic patients in Manaus, State of Amazonas, Brazil

    PubMed Central

    Ferreira, Cristina Motta; Ferreira, William Antunes; Almeida, Nayanne Cristina Oliveira da Silva; Naveca, Felipe Gomes; Barbosa, Maria das Graças Vale

    2011-01-01

    Antibiotic therapy in hematologic patients, often weak and susceptible to a wide range of infections, particularly nosocomial infections derived from long hospitalization periods, is a challenging issue. This paper presents ESBL-producing strains isolated from such hematologic patients treated at the Amazon Hematology and Hemotherapy Foundation (HEMOAM) in the Brazilian Amazon Region to identify the ESBL genes carried by them as well as the susceptibility to 11 antimicrobial agents using the E-test method. A total of 146 clinical samples were obtained from July 2007 to August 2008, when 17 gram-negative strains were isolated in our institution. The most frequent isolates confirmed by biochemical tests and 16S rRNA sequencing were E. coli (8/17), Serratia spp. (3/17) and B.cepacia (2/17). All gram-negative strains were tested for extended-spectrum-beta-lactamases (ESBLs), where: (12/17) strains carried ESBL; among these, (8/12) isolates carried blaTEM, blaCTX-M, blaOXA , blaSHV genes, (1/12) blaTEM gene and (3/12) blaTEM, blaCTX-M, blaOXA genes. Antibiotic resistance was found in (15/17) of the isolates for tetracycline, (12/17) for ciprofloxacin, (1/17) resistance for cefoxitin and chloramphenicol, (1/17) for amikacin and (3/17) cefepime. This research showed the presence of gram-negative ESBL-producing bacteria infecting hematologic patients in HEMOAM. These strains carried the blaTEM, blaSHV, blaCTX-M and blaOXA genes and were resistant to different antibiotics used in the treatment. This finding was based on a period of 13 months, during which clinical samples from specific populations were obtained. Therefore, caution is required when generalizing the results that must be based on posological orientations and new breakpoints for disk diffusion and microdilution published by CLSI 2010. PMID:24031725

  4. A study on the characterization of Propionibacterium acnes isolated from ocular clinical specimens

    PubMed Central

    Sowmiya, Murali; Malathi, Jambulingam; Swarnali, Sen; Priya, Jeyavel Padma; Therese, Kulandai Lily; Madhavan, Hajib N.

    2015-01-01

    Background & objectives: There are only a few reports available on characterization of Propionibacterium acnes isolated from various ocular clinical specimens. We undertook this study to evaluate the role of P. acnes in ocular infections and biofilm production, and also do the phylogenetic analysis of the bacilli. Methods: One hundred isolates of P. acnes collected prospectively from ocular clinical specimens at a tertiary care eye hospital between January 2010 and December 2011, were studied for their association with various ocular disease conditions. The isolates were also subjected to genotyping and phylogenetic analysis, and were also tested for their ability to produce biofilms. Results: Among preoperative conjunctival swabs, P. acnes was a probably significant pathogen in one case; a possibly significant pathogen in two cases. In other clinical conditions, 13 per cent isolates were probably significant pathogens and 38 per cent as possibly significant pathogens. The analysis of 16S rRNA gene revealed four different phylogenies whereas analysis of recA gene showed two phylogenies confirming that recA gene was more reliable than 16S rRNA with less sequence variation. Results of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) had 100 per cent concordance with phylogenetic results. No association was seen between P. acnes subtypes and biofilm production. Interpretation & conclusions: RecA gene phylogenetic studies revealed two different phylogenies. RFLP technique was found to be cost-effective with high sensitivity and specificity in phylogenetic analysis. No association between P. acnes subtypes and pathogenetic ability was observed. Biofilm producing isolates showed increased antibiotic resistance compared with non-biofilm producing isolates. PMID:26609036

  5. Draft Genome Sequence of the First NDM-1-Producing Providencia stuartii Strain Isolated in Portugal.

    PubMed

    Manageiro, Vera; Sampaio, Daniel A; Pereira, Patrícia; Rodrigues, Paulo; Vieira, Luís; Palos, Carlos; Caniça, Manuela

    2015-09-24

    We report here the draft genome sequence of the first NDM-1-producing Providencia stuartii strain isolated in Portugal. Sequence analyses revealed the presence of an incompatibility group A/C2 (IncA/C2) plasmid and of diverse acquired genes conferring resistance to β-lactams, aminoglycosides, tetracycline, macrolides, chloramphenicol, and sulfonamides. This sequence contributes to the evaluation of the spread of NDM-1 producers.

  6. Phylogenetic Analysis of Polygalacturonase-Producing Bacillus and Pseudomonas Isolated From Plant Waste Material

    PubMed Central

    Sohail, Muhammad; Latif, Zakia

    2016-01-01

    Background: Keeping in mind the commercial application of polygalacturonase (PG) in juice and beverages industry, bacterial strains were isolated from rotten fruits and vegetables to screen for competent producers of PG. Objectives: In this study, the plate method was used for preliminary screening of polygalacturonase-producing bacteria, while the Dinitrosalicylic Acid (DNS) method was used for quantifications of PG. Materials and Methods: Biochemically-identified polygalacturonase-producing Bacillus and Pseudomonas species were further characterized by molecular markers. The genetic diversity among these selected strains was analyzed by investigating microsatellite distribution in their genome. Out of 110 strains, 17 competent strains of Bacillus and eight strains of Pseudomonas were selected, identified and confirmed biochemically. Selected strains were characterized by 16S rRNA sequencing and data was submitted to the national center for biotechnology information (NCBI) website for accession numbers. Results: Among the Bacillus, Bacillus vallismortis (JQ990307) isolated from mango was the most competent producer of PG; producing up to 4.4 U/µL. Amongst Pseudomonas, Pseudomonas aeruginosa (JQ990314) isolated from oranges was the most competent PG producer equivalent to B. vallismortis (JQ990307). To determine genetic diversity of different strains of Pseudomonas and Bacillus varying in PG production, fingerprinting was done on the basis of Simple Sequence Repeats (SSR) or microsatellites. The data was analyzed and a phylogenetic tree was constructed using the Minitab 3 software for comparison of bacterial isolates producing different concentrations of PG. Fingerprinting showed that presence or absence of certain microsatellites correlated with the ability of PG production. Conclusions: Bacteria from biological waste were competent producers of PG and must be used on an industrial scale to cope with the demand of PG in the food industry. PMID:27099686

  7. NDM-1-producing Acinetobacter baumannii ST85 now in Turkey, including one isolate from a Syrian refugee.

    PubMed

    Heydari, Farzad; Mammina, Caterina; Koksal, Fatih

    2015-09-01

    New Delhi metallo-β-lactamase-1 (NDM-1), an acquired class B carbapenemase, is a significant clinical threat owing to the extended hydrolysis of β-lactams including carbapenems. Here, to the best of our knowledge we describe for the first time in Turkey two NDM-1-producing Acinetobacter baumannii isolates recovered from intensive care unit patients. The presence of blaNDM-1 was detected by PCR and confirmed by sequencing. The clonal relationship was assessed by PFGE and multilocus sequence typing. Both isolates were positive for blaNDM-1 and were attributed with the sequence type 85. One isolate was from a Syrian refugee, whereas the second was from a patient who had never travelled outside Turkey. Our findings confirmed that the rapid spread of NDM-1-producing Gram-negative organisms could become a major challenge for the treatment and control of healthcare-associated infections in our geographical area. They suggest also that NDM-1-producing strains and/or their genetic determinants are probably being imported from Syria to neighbouring countries.

  8. Molecular Typing of Environmental and Clinical Strains of Vibrio vulnificus Isolated in the Northeastern USA

    PubMed Central

    Reynaud, Yann; Pitchford, Steven; De Decker, Sophie; Wikfors, Gary H.; Brown, Christopher L.

    2013-01-01

    Vibrio vulnificus is a ubiquitous marine bacterium that is responsible for infections and some seafood-related illnesses and deaths in the United States, mainly in individuals with compromised health status in the Gulf of Mexico region. Most phylogenetic studies focus on V. vulnificus strains isolated in the southern United States, but almost no genetic data are available on northeastern bacterial isolates of clinical or environmental origin. Our goal in this study was to examine the genetic diversity of environmental strains isolated from commercially-produced oysters and in clinical strains of known pathogenicity in northeastern United States. We conducted analyses of a total of eighty-three strains of V. vulnificus, including 18 clinical strains known to be pathogenic. A polyphasic, molecular-typing approach was carried out, based upon established biotypes, vcg, CPS, 16S rRNA types and three other genes possibly associated with virulence (arylsulfatase A, mtlABC, and nanA). An established Multi Locus Sequence Typing (MLST) method was also performed. Phylogenetic analyses of these markers and MLST results produced similar patterns of clustering of strains into two main lineages (we categorized as ‘LI’ and ‘LII’), with clinical and environmental strains clustering together in both lineages. Lineage LII was comprised primarily but not entirely of clinical bacterial isolates. Putative virulence markers were present in both clinical and environmental strains. These results suggest that some northeastern environmental strains of V. vulnificus are phylogenetically close to clinical strains and probably are capable of virulence. Further studies are necessary to assess the risk of human illness from consuming raw oysters harvested in the northeastern US. PMID:24386187

  9. Molecular typing of environmental and clinical strains of Vibrio vulnificus isolated in the northeastern USA.

    PubMed

    Reynaud, Yann; Pitchford, Steven; De Decker, Sophie; Wikfors, Gary H; Brown, Christopher L

    2013-01-01

    Vibrio vulnificus is a ubiquitous marine bacterium that is responsible for infections and some seafood-related illnesses and deaths in the United States, mainly in individuals with compromised health status in the Gulf of Mexico region. Most phylogenetic studies focus on V. vulnificus strains isolated in the southern United States, but almost no genetic data are available on northeastern bacterial isolates of clinical or environmental origin. Our goal in this study was to examine the genetic diversity of environmental strains isolated from commercially-produced oysters and in clinical strains of known pathogenicity in northeastern United States. We conducted analyses of a total of eighty-three strains of V. vulnificus, including 18 clinical strains known to be pathogenic. A polyphasic, molecular-typing approach was carried out, based upon established biotypes, vcg, CPS, 16S rRNA types and three other genes possibly associated with virulence (arylsulfatase A, mtlABC, and nanA). An established Multi Locus Sequence Typing (MLST) method was also performed. Phylogenetic analyses of these markers and MLST results produced similar patterns of clustering of strains into two main lineages (we categorized as 'LI' and 'LII'), with clinical and environmental strains clustering together in both lineages. Lineage LII was comprised primarily but not entirely of clinical bacterial isolates. Putative virulence markers were present in both clinical and environmental strains. These results suggest that some northeastern environmental strains of V. vulnificus are phylogenetically close to clinical strains and probably are capable of virulence. Further studies are necessary to assess the risk of human illness from consuming raw oysters harvested in the northeastern US.

  10. Clinical and veterinary isolates of Salmonella enterica serovar Enteritidis defective in lipopolysaccharide O-chain polymerization

    SciTech Connect

    Guard-Petter, J.; Parker, C.T.; Asokan, K.; Carlson, R.W.

    1999-05-01

    Twelve human and chicken isolates of Salmonella enterica serovar Enteritidis belonging to phage types 4, 8, 13a, and 23 were characterized for variability in lipopolysaccharide (LPS) composition. Isolates were differentiated into two groups, i.e., those that lacked immunoreactive O-chain, termed rough isolates, and those that had immunoreactive O-chain, termed smooth isolates. Isolates within these groups could be further differentiated by LPS compositional differences as detected by gel electrophoresis and gas liquid chromatography of samples extracted with water, which yielded significantly more LPS in comparison to phenol-chloroform extraction. The rough isolates were of two types, the O-antigen synthesis mutants and the O-antigen polymerization (wzy) mutants. Smooth isolates were also of two types, one producing low-molecular-weight (LMW) LPS and the other producing high-molecular-weight (HMW) LPS. To determine the genetic basis for the O-chain variability of the smooth isolates, the authors analyzed the effects of a null mutation in the O-chain length determinant gene, wzz (cld) of serovar Typhimurium. This mutation results in a loss of HMW LPS; however, the LMW LPS of this mutant was longer and more glucosylated than that from clinical isolates of serovar Enteritidis. Cluster analysis of these data and of those from two previously characterized isogenic strains of serovar Enteritidis that had different virulence attributes indicated that glucosylation of HMW LPS (via oafR function) is variable and results in two types of HMW structures, one that is highly glucosylated and one that is minimally glucosylated. These results strongly indicate that naturally occurring variability in wzy, wzz, and oafR function can be used to subtype isolates of serovar Enteritidis during epidemiological investigations.

  11. Characteristics of community-onset NDM-1-producing Klebsiella pneumoniae isolates.

    PubMed

    Kim, So Yeon; Rhee, Ji-Young; Shin, Sang Yop; Ko, Kwan Soo

    2014-01-01

    Multilocus sequence typing and in vitro antimicrobial susceptibility testing were performed for three community-onset New Delhi metallo-β-lactamase-1 (NDM-1)-producing Klebsiella pneumoniae isolates from Korea. The genetic structure surrounding the blaNDM-1 gene was determined in blaNDM-1-harbouring plasmids. Three NDM-1-producing K. pneumoniae isolates were found to belong to the same clone (sequence type 340). Each of these isolates showed the same genetic structure surrounding the blaNDM-1 gene. The genes blaNDM-1, bleMBL, trpF and dsbC were flanked by two intact insertion sequences, ISAba125 and IS26, which may promote horizontal gene transfer. The blaNDM-1-harbouring plasmids conferred antimicrobial resistance to carbapenems, cephalosporins, aminoglycosides and aztreonam in transconjugants. It can be speculated that either the entire blaNDM-1-harbouring plasmids or just the part of the plasmid containing the blaNDM-1 gene may have transferred between K. pneumoniae and Escherichia coli. Following the transfer, the isolate disseminated throughout Korea. This study suggests the need for monitoring the dissemination of NDM-1-producing isolates across countries or continents due to their potential transferability via ISAba125- and IS26-associated transposons.

  12. Prevalence of extended-spectrum beta-lactamase-producing Enterobacteriaceae isolated from blood cultures in Africa.

    PubMed

    Sangare, S A; Maiga, A I; Guindo, I; Maiga, A; Camara, N; Savadogo, S; Diallo, S; Bougoudogo, F; Armand-Lefevre, L; Andremont, A; Maiga, I I

    2015-09-01

    Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae have been isolated from many regions of the world. Epidemiological studies are being conducted in Europe, North America, and Asia. No study has however been conducted in Africa to determine the prevalence and distribution of ESBLs on the continent. This literature review aimed at describing the prevalence of ESBL-producing Enterobacteriaceae isolated from blood cultures, as well as the ESBL genes involved at the international level. Our focus was mainly on Africa. We conducted a literature review on PubMed. Articles related to our study field and published between 1996 and 2014 were reviewed and entirely read for most of them, while we only focused on the abstracts of some other articles. Relevant articles to our study were then carefully reviewed and included in the review. The prevalence of ESBL-producing Enterobacteriaceae differs from one country to another. The results of our literature review however indicate that class A ESBLs prevail over the other types. We took into consideration articles focusing on various types of samples to assess the prevalence of ESBL-producing Enterobacteriaceae, but information on isolates from blood cultures is limited. The worldwide prevalence of ESBL-producing Enterobacteriaceae has increased over time. Evidence of ESBL-producing Enterobacteriaceae can be found in all regions of the world. Studies conducted in Africa mainly focused on the Northern and Eastern parts of the continent, while only rare studies were carried out in the rest of the continent.

  13. Molecular distinctions among clinical isolates of Mycoplasma pneumoniae.

    PubMed Central

    Su, C J; Dallo, S F; Baseman, J B

    1990-01-01

    Restriction enzyme fingerprinting of genomic DNA and Southern blots probed with subclones of the Mycoplasma pneumoniae cytadhesin P1 gene were used to characterize clinical isolates of M. pneumoniae. On the basis of the examination of 29 individual M. pneumoniae isolates, two distinct groups were established. Group 1, which displayed a 12-kilobase band following DNA digestion with HindIII, consisted of strain M129-B16 and three others obtained in the state of Washington during the 1960s. The remaining M. pneumoniae strains belonged to group 2, which lacked the 12-kilobase band and included samples from the 1940s, 1970s, and 1980s. This category also included the only M. pneumoniae strain isolated from the synovial fluid of an arthritic patient. Images PMID:2166088

  14. Isolation and identification of ochratoxin A-producing Aspergillus section Nigri strains from California raisins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: To determine incidence and levels of ochratoxin A (OTA) in California raisins, and to isolate and characterize OTA-producing fungi from California raisin vineyards. Methods and Results: Raisin clusters sampled from four California vineyards in the San Joaquin Valley were analyzed for OTA con...

  15. Clonal Dissemination of Pseudomonas aeruginosa Isolates Producing Extended-Spectrum β-Lactamase SHV-2a

    PubMed Central

    Jeannot, Katy; Fournier, Damien; Müller, Emeline; Cholley, Pascal

    2013-01-01

    From January to December 2011, 24 Pseudomonas aeruginosa strains producing the extended-spectrum β-lactamase SHV-2a were identified in 13 hospitals in France. With one exception, all the strains belonged to the same clone. Double-disk synergy tests with cefepime and clavulanate were able to detect all the SHV-2a-positive isolates. PMID:23241379

  16. Clonal dissemination of Pseudomonas aeruginosa isolates producing extended-spectrum β-lactamase SHV-2a.

    PubMed

    Jeannot, Katy; Fournier, Damien; Müller, Emeline; Cholley, Pascal; Plésiat, Patrick

    2013-02-01

    From January to December 2011, 24 Pseudomonas aeruginosa strains producing the extended-spectrum β-lactamase SHV-2a were identified in 13 hospitals in France. With one exception, all the strains belonged to the same clone. Double-disk synergy tests with cefepime and clavulanate were able to detect all the SHV-2a-positive isolates.

  17. Isolation and Characterization of Rhamnolipid-Producing Bacterial Strains from a Biodiesel Facility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel strains of rhamnolipid-producing bacteria were isolated from soils at a biodiesel facility on the basis of their ability to grow on glycerol as a sole carbon source. Strains were identified as Acinetobacter calcoaceticus, Enterobacter asburiae, E. hormaecheii, Pantoea stewartii and Pseudomona...

  18. Selection and Characterization of Biofuel-Producing Environmental Bacteria Isolated from Vegetable Oil-Rich Wastes

    PubMed Central

    Escobar-Niño, Almudena; Luna, Carlos; Luna, Diego; Marcos, Ana T.; Cánovas, David; Mellado, Encarnación

    2014-01-01

    Fossil fuels are consumed so rapidly that it is expected that the planet resources will be soon exhausted. Therefore, it is imperative to develop alternative and inexpensive new technologies to produce sustainable fuels, for example biodiesel. In addition to hydrolytic and esterification reactions, lipases are capable of performing transesterification reactions useful for the production of biodiesel. However selection of the lipases capable of performing transesterification reactions is not easy and consequently very few biodiesel producing lipases are currently available. In this work we first isolated 1,016 lipolytic microorganisms by a qualitative plate assay. In a second step, lipolytic bacteria were analyzed using a colorimetric assay to detect the transesterification activity. Thirty of the initial lipolytic strains were selected for further characterization. Phylogenetic analysis revealed that 23 of the bacterial isolates were Gram negative and 7 were Gram positive, belonging to different clades. Biofuel production was analyzed and quantified by gas chromatography and revealed that 5 of the isolates produced biofuel with yields higher than 80% at benchtop scale. Chemical and viscosity analysis of the produced biofuel revealed that it differed from biodiesel. This bacterial-derived biofuel does not require any further downstream processing and it can be used directly in engines. The freeze-dried bacterial culture supernatants could be used at least five times for biofuel production without diminishing their activity. Therefore, these 5 isolates represent excellent candidates for testing biofuel production at industrial scale. PMID:25099150

  19. Isolation and identification of bacterial endophytes from pharmaceutical agarwood-producing Aquilaria species

    PubMed Central

    Bhore, Subhash J.; Preveena, Jagadesan; Kandasamy, Kodi I.

    2013-01-01

    Background: Resins and gums are used in traditional medicine and do have potential applications in pharmacy and medicine. Agarwood is the fragrant resinous wood, which is an important commodity from Aquilaria species and has been used as a sedative, analgesic, and digestive in traditional medicine. Endophytic bacteria are potentially important in producing pharmaceutical compounds found in the plants. Hence, it was important to understand which types of endophytic bacteria are associated with pharmaceutical agarwood-producing Aquilaria species. Objective: This study was undertaken to isolate and identify endophytic bacteria associated with agarwood-producing seven (7) Aquilaria species from Malaysia. Materials and Methods: Botanical samples of seven Aquilaria species were collected, and endophytic bacteria were isolated from surface-sterilized-tissue samples. The 16S rRNA gene fragments were amplified using PCR method, and endophytic bacterial isolates (EBIs) were identified based on 16S rRNA gene sequence similarity based method. Results: Culturable, 77 EBIs were analyzed, and results of 16S rRNA gene sequences analysis suggest that 18 different types of endophytic bacteria are associated with (seven) Aquilaria species. From 77 EBIs, majority (36.4%) of the isolates were of Bacillus pumilus. Conclusion: These findings indicate that agarwood-producing Aquilaria species are harboring 18 different types of culturable endophytic bacteria. PMID:23798890

  20. Draft Genome Sequence of the Soil Isolate Lysinibacillus fusiformis M5, a Potential Hypoxanthine Producer

    PubMed Central

    Maróti, Gergely; Bálint, Balázs

    2016-01-01

    Lysinibacillus fusiformis strain M5 is a potential hypoxanthine producer that was isolated from clay soil. Here, we present the draft genome sequence that was annotated in order to facilitate future studies of L. fusiformis M5. PMID:27834716

  1. Development of an automated multiplexed immunomagnetic separation system for isolating Shiga toxin-producing Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, non-O157 Shiga toxin-producing Escherichia coli(STEC) have become an emerging problem. Efforts have been devoted to facilitating and speeding their detection, however, their isolation from high background microbiota foods remains problematic. To solve this problem, immunomagnetic se...

  2. Selection and characterization of biofuel-producing environmental bacteria isolated from vegetable oil-rich wastes.

    PubMed

    Escobar-Niño, Almudena; Luna, Carlos; Luna, Diego; Marcos, Ana T; Cánovas, David; Mellado, Encarnación

    2014-01-01

    Fossil fuels are consumed so rapidly that it is expected that the planet resources will be soon exhausted. Therefore, it is imperative to develop alternative and inexpensive new technologies to produce sustainable fuels, for example biodiesel. In addition to hydrolytic and esterification reactions, lipases are capable of performing transesterification reactions useful for the production of biodiesel. However selection of the lipases capable of performing transesterification reactions is not easy and consequently very few biodiesel producing lipases are currently available. In this work we first isolated 1,016 lipolytic microorganisms by a qualitative plate assay. In a second step, lipolytic bacteria were analyzed using a colorimetric assay to detect the transesterification activity. Thirty of the initial lipolytic strains were selected for further characterization. Phylogenetic analysis revealed that 23 of the bacterial isolates were Gram negative and 7 were Gram positive, belonging to different clades. Biofuel production was analyzed and quantified by gas chromatography and revealed that 5 of the isolates produced biofuel with yields higher than 80% at benchtop scale. Chemical and viscosity analysis of the produced biofuel revealed that it differed from biodiesel. This bacterial-derived biofuel does not require any further downstream processing and it can be used directly in engines. The freeze-dried bacterial culture supernatants could be used at least five times for biofuel production without diminishing their activity. Therefore, these 5 isolates represent excellent candidates for testing biofuel production at industrial scale.

  3. Draft Genome Sequence of Lactobacillus collinoides CUPV237, an Exopolysaccharide and Riboflavin Producer Isolated from Cider

    PubMed Central

    Puertas, Ana Isabel; Capozzi, Vittorio; Llamas, María Goretti; López, Paloma; Lamontanara, Antonella; Orrù, Luigi; Russo, Pasquale; Spano, Giuseppe

    2016-01-01

    Lactobacillus collinoides CUPV237 is a strain isolated from a Basque cider. Lactobacillus collinoides is one of the most frequent species found in cider from Spain, France, or England. A notable feature of the L. collinoides CUPV237 strain is its ability to produce exopolysaccharides. PMID:27284133

  4. [Antibiotic susceptibility and identification of clinical Pseudomonas fulva isolates].

    PubMed

    Sivolodsky, E P; Gorelova, G V; Bogoslovskaya, S P; Zueva, E V

    2014-01-01

    The earliest eight clinical strains of Pseudomonas fulva were identified in the culture collection of pseudomonads isolated in St. Petersburg in 1995-2005, that confirmed the medical importance of the species. A high level of the species identification of all the strains of P. fulva by MALDI-TOF mass-spectrometry with the use of Microflex device with database MALDI Biotyper (Bruker Daltonics Inc.) was shown. Tests for routine studies providing identification of P. fulva without the use of genetic methods were approved. The profile of the antibiotic susceptibility of the clinical strains of P. fulva was described. Acquired resistance of two P. fulva isolates to the 3rd generation cephalosporins and chloramphenicol was detected.

  5. Chemotaxonomy and molecular taxonomy of some coryneform clinical isolates.

    PubMed

    Carlotti, A; Meugnier, H; Pommier, M T; Villard, J; Freney, J

    1993-02-01

    Six reference strains of the genus Brevibacterium as well as fifteen clinical isolates tentatively assigned to the genus using conventional biochemical methods, were the subject of chemotaxonomic and DNA similarity studies. Five of these clinical isolates were assigned either to the genera Aureobacterium, Mycobacterium, Gordona or to Rhodococcus on the basis of their DNA mol% G+C, mycolic acid, amino-acid, sugar and menaquinone contents. Among the ten remaining strains, six were not brevibacteria and only four conformed to the description of the genus Brevibacterium sensu stricto. These strains showed low values of DNA relatedness with Brevibacterium epidermidis ATCC 35514T and Brevibacterium linens ATCC 9174, and could only be described as Brevibacterium spp. The results indicate that studies of chemical markers are essential for the correct identification of brevibacteria.

  6. Adult Vampire Bats Produce Contact Calls When Isolated: Acoustic Variation by Species, Population, Colony, and Individual

    PubMed Central

    Carter, Gerald G.; Logsdon, Ryane; Arnold, Bryan D.; Menchaca, Angelica; Medellin, Rodrigo A.

    2012-01-01

    Background Bat pups produce individually distinct isolation calls to facilitate maternal recognition. Increasing evidence suggests that, in group-living bat species, adults often use similar calls to maintain contact. We investigated if isolated adults from all three species of the highly cooperative vampire bats (Phyllostomidae: Desmodontinae) would produce vocally distinct contact calls when physically isolated. Methods/Principal Findings We assessed variation in contact calls recorded from isolated captive and wild-caught adult common vampire bats (Desmodus rotundus), white-winged vampire bats (Diaemus youngi) and hairy-legged vampire bats (Diphylla ecaudata). We compared species-typical contact call structure, and used information theory and permuted discriminate function analyses to examine call structure variation, and to determine if the individuality of contact calls is encoded by different call features across species and populations. We found that isolated adult vampire bats produce contact calls that vary by species, population, colony, and individual. However, much variation occurred within a single context and individual. We estimated signature information for captive Diaemus (same colony), captive Desmodus (same colony), and wild Desmodus (different colonies) at 3.21, 3.26, and 3.88 bits, respectively. Contact calls from a captive colony of Desmodus were less individually distinct than calls from wild-caught Desmodus from different colonies. Both the degree of individuality and parameters encoding individuality differed between the bats from a single captive colony and the wild-caught individuals from different groups. This result is consistent with, but not sufficient evidence of, vocal convergence in groups. Conclusion Our results show that adult vampire bats of all three species produce highly variable contact calls when isolated. Contact calls contain sufficient information for vocal discrimination, but also possess more intra-individual variation

  7. A clinical Acanthamoeba isolate harboring two distinct bacterial endosymbionts.

    PubMed

    Müller, Anneliese; Walochnik, Julia; Wagner, Martin; Schmitz-Esser, Stephan

    2016-10-01

    Acanthamoebae feed on bacteria but are also frequent hosts of bacterial symbionts. Here, we describe the stable co-occurrence of two symbionts, one affiliated to the genus Parachlamydia and the other to the candidate genus Paracaedibacter (Alphaproteobacteria), within a clinical isolate of Acanthamoeba hatchetti genotype T4. We performed fluorescence in situ hybridization (FISH) and transmission electron microscopy (TEM) to describe this symbiosis. Our study adds to other reports of simultaneous co-occurrence of two symbionts within one Acanthamoeba cell.

  8. Genotyping and characterization of CTX-M-15 -producing Klebsiella pneumoniae isolated from an Iranian hospital.

    PubMed

    Derakhshan, Safoura; Peerayeh, Shahin Najar; Bakhshi, Bita

    2016-08-01

    The aims were to describe the genetic characterization of blaCTX-M-1 group gene in Klebsiella pneumoniae and to investigate the relationship between isolates by MLVA and PFGE. We analyzed 36 CTX-M group 1-ESBL producing K. pneumoniae. rmpA and wcaG virulence genes were identified by PCR. The genetic environment of blaCTX-M-1 was analyzed by PCR and sequencing. Plasmid replicons were determined using PCR-based replicon typing. The isolates were typed by MLVA and PFGE. All blaCTX-M-1 were blaCTX-M-15. The wcaG and rmpA were detected in 1 and 2 isolates, respectively. IncF were the most frequently detected replicons (63.88%). In all isolates, ISEcp1 was found upstream and orf477 downstream of blaCTX-M-15, IS26 was found in two isolates. MLVA identified 20 MLVA types, whereas PFGE identified 25 different profiles. The dissemination of CTX-M-15 in our isolates was due to the clonal spread of isolates and to the genetic transfer of mobile elements among unrelated strains.

  9. Characterization of the neurotoxin produced by isolates associated with avian botulism.

    PubMed

    Takeda, Masato; Tsukamoto, Kentaro; Kohda, Tomoko; Matsui, Miki; Mukamoto, Masafumi; Kozaki, Shunji

    2005-09-01

    Several varieties of birds are affected by type C botulism. We conducted neutralization tests of culture supernatants of isolates from cases of avian botulism. Whereas the toxin produced by isolates derived from mammalian botulism was neutralized only with type C antitoxin, the toxins of all isolates related to avian botulism were neutralized with both type C and D antitoxins. An analysis of nucleotide sequences with several strains revealed that the neurotoxin gene in the isolates from avian botulism comprises two thirds of the type C neurotoxin gene and one third of the type D neurotoxin gene. This indicates that the neurotoxin of avian isolates is a mosaic of type C and D neurotoxins. We prepared three sets of primers to differentiate the gene for the mosaic form from the conserved genes of type C and D neurotoxins. The results of polymerase chain reaction with these primers indicated that all avian botulism-related isolates and specimens possess the gene for the mosaic form of the neurotoxin. The toxins purified from avian and mammalian isolates exhibited the same degree of lethality in mice, but the former showed greater toxicity to chickens than the latter. These results indicate that the mosaic neurotoxin is probably a pathogenic agent causing some forms of avian botulism.

  10. Screening and characterization of extracellular polysaccharides produced by Leuconostoc kimchii isolated from traditional fermented pulque beverage.

    PubMed

    Torres-Rodríguez, Ingrid; Rodríguez-Alegría, María Elena; Miranda-Molina, Alfonso; Giles-Gómez, Martha; Conca Morales, Rodrigo; López-Munguía, Agustín; Bolívar, Francisco; Escalante, Adelfo

    2014-01-01

    We report the screening and characterization of EPS produced by LAB identified as Leuconostoc kimchii isolated from pulque, a traditional Mexican fermented, non-distilled alcoholic beverage produced by the fermentation of the sap extracted from several (Agave) maguey species. EPS-producing LAB constitutes an abundant bacterial group relative to total LAB present in sap and during fermentation, however, only two EPS-producing colony phenotypes (EPSA and EPSB, respectively) were detected and isolated concluding that despite the high number of polymer-producing LAB their phenotypic diversity is low. Scanning electron microcopy analysis during EPS-producing conditions revealed that both types of EPS form a uniform porous structure surrounding the bacterial cells. The structural characterization of the soluble and cell-associated EPS fractions of each polymer by enzymatic and acid hydrolysis, as by 1D- and 2D-NMR, showed that polymers produced by the soluble and cell-associated fractions of EPSA strain are dextrans consisting of a linear backbone of linked α-(1→6) Glcp in the main chain with α-(1→2) and α-(1→3)-linked branches. The polymer produced by the soluble fraction of EPSB strain was identified as a class 1 dextran with a linear backbone containing consecutive α-(1→6)-linked D-glucopyranosyl units with few α-(1→3)-linked branches, whereas the cell-associated EPS is a polymer mixture consisting of a levan composed of linear chains of (2→6)-linked β-D-fructofuranosyl residues with β-(2→6) connections, and a class 1 dextran. According to our knowledge this is the first report of dextrans and a levan including their structural characterization produced by L. kimchii isolated from a traditional fermented source.

  11. Genetic diversity of multidrug resistant Staphylococcus aureus isolated from clinical and non clinical samples in Egypt.

    PubMed

    Bendary, M M; Solyman, S M; Azab, M M; Mahmoud, N F; Hanora, A M

    2016-08-31

    In recent years, the increasing incidence of diseases caused by Staphylococcus aureus (S. aureus) has been noted in the university hospitals of El-Sharkia and Assuit governorates - Egypt. Therefore, we studied the genetic relatedness of multidrug resistant S. aureus isolates from different sources in the above mentioned governorates. One hundred and fifty six S. aureus isolates were divided into 5 different groups, 1 non clinical isolates from different food products and 4 different clinical isolates of human and animal sources in the 2 different governorates. Epidemiological characteristics of 156 S. aureus isolates were determined by phenotypic methods including quantitative antibiogram typing and biofilm production. Genetic typing of 35 multidrug resistant (MDR) isolates (7 from each group) based on 16S rRNA gene sequence, virulence and antimicrobial resistance gene profiles was done. The genetic relatedness of the highest virulent strain from each group was detected based on different single locus sequence typing and multi-locus sequence typing (MLST). S. aureus strains isolated from different sources and geographical areas showed high diversity. The genetic typing revealed different sequence types and different sequences of coa and spa genes. S. aureus isolates were found highly diverse in Egypt.

  12. Investigation of biofilm formation in clinical isolates of Staphylococcus aureus.

    PubMed

    Cassat, James E; Lee, Chia Y; Smeltzer, Mark S

    2007-01-01

    As with many other bacterial species, the most commonly used method to assess staphylococcal biofilm formation in vitro is the microtiter plate assay. This assay is particularly useful for comparison of multiple strains including large-scale screens of mutant libraries. When such screens are applied to the coagulase-negative staphylococci in general, and Staphylococcus epidermidis in particular, they are relatively straightforward by comparison with microtiter plate assays used to assess biofilm formation in other bacterial species. However, in the case of clinical isolates of Staphylococcus aureus, including methicillin-resistant S. aureus, we have found it necessary to employ specific modifications including precoating of the wells of the microtiter plate with plasma proteins and supplementation of the medium with both salt and glucose. In this chapter, we describe the microtiter plate assay in the specific context of clinical isolates of S. aureus and the use of these modifications. A second in vitro method, which also is generally dependent on coating with plasma proteins and supplementation of the growth medium, is the use of flow cells. In this method, bacteria are allowed to attach to a surface and then monitored with respect to their ability to remain attached to the substrate and differentiate into mature biofilms under the constant pressure of fluid shear force. Although flow cells are not applicable to large-scale screens, we have found that they provide a more reproducible and accurate assessment of the capacity of S. aureus clinical isolates to form a biofilm. They also provide a means of analyzing structural differences in biofilm architecture and isolating bacteria and/or spent media for analysis of physiological and metabolic changes associated with the adaptive response to growth in a biofilm. While a primary focus of this chapter is on the use of in vitro assays to assess biofilm formation in clinical isolates of S. aureus, it is important to

  13. Occurrence of class 1 integrons in uropathogenic fluoroquinolone-resistant clinical Escherichia coli isolates from Jamaica.

    PubMed

    Stephenson, Stacy A M; Brown, Paul D

    2013-03-01

    Quinolone resistance is generally caused by chromosomal mutations, but has been more recently found associated with the plasmid-mediated qnr genes. The objective of this study was to screen and analyse polymorphisms of integrons in clinical isolates of Escherichia coli in Jamaica. Previous studies in Jamaica identified fluoroquinolone resistance in predominantly uropathogenic E. coli clinical isolates: 45% harbouring qnrA, qnrB and/or qnrS, and 17% were (Extended-spectrum beta-lactamase) ESBL-producers. These isolates were analysed for the presence and variation of class 1 and 2 integrase genes, 5'- and 3'- conserved segments and the Orf513 recombinase gene by primer-specific polymerase chain reaction (PCR) and restriction fragment-length polymorphism (RFLP). Results indicated integron-encoded integrases in 93% of isolates primarily harbouring class 1 integrase genes; four of 58 isolates carried both classes. The Orf513 and 5'- and 3'-conserved segment (CS) regions were identified in 83% and 55% of the isolates respectively. RFLP evaluation of the 5'- and 3'-CS regions in int1-positive strains yielded two main types. The reduced diversity, but wide dispersion of class 1 integrons harbouring qnr genes may give rise to the conservation of the mobile genetic elements in which they are carried.

  14. Isolation and Genetic Characterization of a Coinfection of Non-O157 Shiga Toxin-Producing Escherichia coli▿

    PubMed Central

    Gilmour, Matthew W.; Tabor, Helen; Wang, Gehua; Clark, Clifford G.; Tracz, Dobryan M.; Olson, Adam B.; Mascarenhas, Mariola; Karmali, Mohamed A.; Mailman, Tim; Ng, Lai-King

    2007-01-01

    A coinfection of O177:NM and O55:H7 Shiga toxin-producing Escherichia coli (STEC) was identified for a child with acute bloody diarrhea and hemolytic uremic syndrome by using culture and serotype-specific molecular reagents. The profile of O157-related genetic islands revealed that the O55:H7 isolate was highly similar to O157 STEC whereas the O177:NM isolate lacked several fimbrial O islands and non-locus-of-enterocyte-effacement effector determinants. However, both STEC serotypes are known to cause serious disease, and the significant repertoire of virulence determinants in both strains made it impossible to determine their individual contributions to the clinical symptoms. PMID:17804662

  15. Isolation and identification of tyramine-producing enterococci from human fecal samples.

    PubMed

    Ladero, Victor; Fernández, María; Alvarez, Miguel A

    2009-02-01

    Lactic acid bacteria (LAB) are recognized as a group of important microorganisms because of their crucial role in food fermentation and their contribution to the maintenance of health homeostasis, as natural inhabitants of the human mucosa. However, the metabolic activities of some strains, such as the ability to synthesize biogenic amines (BAs), can be detrimental to human health. BAs are low molecular weight compounds synthesized by the enzymatic decarboxylation of amino acids. Tyramine, one of the most biologically active BAs, is produced by certain strains of LAB related to food fermentations. Since no data are available as to whether tyramine originates exclusively from food intake, or, like polyamines, could be formed by gut bacteria, this study was focused on the isolation of tyramine-producing LAB from human feces. Different strains of Enterococcus faecium and Enterococcus faecalis able to produce tyramine in culture conditions were isolated.

  16. Isolation and typification of histamine-producing Lactobacillus vaginalis strains from cheese.

    PubMed

    Diaz, Maria; del Rio, Beatriz; Ladero, Victor; Redruello, Begoña; Fernández, María; Martin, Maria Cruz; Alvarez, Miguel A

    2015-12-23

    In food, the biogenic amine (BA) histamine is mainly produced by histidine decarboxylation catalysed by microbial histidine decarboxylase. The consumption of foods containing high concentrations of histamine can trigger adverse neurological, gastrointestinal and respiratory reactions. Indeed, histamine is one of the most toxic of all BAs, and is often detected in high concentration in cheese. However, little is known about the microorganisms responsible for its accumulation in this food. In the present work, 25 histamine-producing Lactobacillus vaginalis strains were isolated from a blue-veined cheese (the first time that histamine-producing strains of this species have been isolated from any food). The restriction profiles of their genomes were analysed by PFGE, and seven lineages identified. The presence of the histidine decarboxylase gene (hdcA) was confirmed by PCR. The nucleotide sequence and genetic organisation of the histamine biosynthesis gene cluster (HDC) and its flanking regions are described for a representative strain (L. vaginalis IPLA11050).

  17. Isolation and characterization of actinomycetes strains that produce phospholipase D having high transphosphatidylation activity.

    PubMed

    Nakazawa, Yozo; Uchino, Masataka; Sagane, Yoshimasa; Sato, Hiroaki; Takano, Katsumi

    2009-01-01

    The present study was conducted to screen microorganisms that produce phospholipase D (PLD), and we especially focused on the strains having high transphosphatidylation activity. Eighty bacterial strains were isolated from soil samples by a screening method utilizing a preliminary selection medium with phosphatidylcholine (PC) as the sole carbon source. The culture supernatants were then assayed for PLD activity. The finding of dual PLD activities in cultures revealed that the hydrolytic and transphosphatidylation activities were correlated. Consequently, six strains were selected as stably producing PLD enzyme(s) during continuous subcultures. The culture supernatants of selected strains synthesized phosphatidylglycerol, phosphatidylserine and phosphatidylethanolamine from PC with high conversion rates. These isolated strains will be made available to carry out phospholipid modification through the efficient transphosphatidylation activity of the PLD that they produce.

  18. Molecular characterization of clinical Streptococcus pneumoniae isolates with reduced susceptibility to fluoroquinolones emerging in Italy.

    PubMed

    Montanari, Maria Pia; Tili, Emily; Cochetti, Ileana; Mingoia, Marina; Manzin, Aldo; Varaldo, Pietro Emanuele

    2004-01-01

    Fifteen Streptococcus pneumoniae clinical isolates with reduced fluoroquinolone susceptibility (defined as a ciprofloxacin MIC of > or = 4 microg/ml), all collected in Italy in 2000-2003, were typed and subjected to extensive molecular characterization to define the contribution of drug target alterations and efflux mechanisms to their resistance. Serotyping and pulsed-field gel electrophoresis analysis indicated substantial genetic unrelatedness among the 15 isolates, suggesting that the new resistance traits arise in multiple indigenous strains rather than through clonal dissemination. Sequencing of the quinolone resistance-determining regions of gyrA, gyrB, parC, and parE demonstrated that point mutations producing single amino acid changes were more frequent in topoisomerase IV (parC mutations in 14 isolates and parE mutations in 13) than in DNA gyrase subunits (gyrA mutations in 7 isolates and no gyrB mutations observed). No isolate displayed a quinolone efflux system susceptible to carbonyl cyanide m-chlorophenylhydrazone; conversely, four-fold or greater MIC reductions in the presence of reserpine were observed in all 15 isolates with ethidium bromide, in 13 with ulifloxacin, in 9 with ciprofloxacin, in 5 with norfloxacin, and in none with five other fluoroquinolones. The effect of efflux pump activity on the level and profile of fluoroquinolone resistance in our strains was minor compared with that of target site modifications. DNA mutations and/or efflux systems other than those established so far might contribute to the fluoroquinolone resistance expressed by our strains. Susceptibility profiles to nonquinolone class antibiotics and resistance-associated phenotypic and genotypic characteristics were also determined and correlated with fluoroquinolone resistance. A unique penicillin-binding protein profile was observed in all five penicillin-resistant isolates, whereas the same PBP profile as S. pneumoniae R6 was exhibited by all six penicillin

  19. Risk Factors and Clinical Impact of Klebsiella pneumoniae Carbapenemase–Producing K. pneumoniae

    PubMed Central

    Gasink, Leanne B.; Edelstein, Paul H.; Lautenbach, Ebbing; Synnestvedt, Marie; Fishman, Neil O.

    2010-01-01

    BACKGROUND Klebsiella pneumoniae carbapenemase (KPC)–producing K. pneumoniae is an emerging pathogen with serious clinical and infection control implications. To our knowledge, no study has specifically examined risk factors for KPC-producing K. pneumoniae or its impact on mortality. METHODS To identify risk factors for infection or colonization with KPC-producing K. pneumoniae, a case-control study was performed. Case patients with KPC-producing K. pneumoniae were compared with control subjects with carbapenem-susceptible K. pneumoniae. A cohort study evaluated the association between KPC-producing K. pneumoniae and in-hospital mortality. RESULTS Fifty-six case patients and 863 control subjects were identified. In multivariable analysis, independent risk factors for KPC-producing K. pneumoniae were (1) severe illness (adjusted odds ratio [AOR], 4.31; 95% confidence interval [CI], 2.25–8.25), (2) prior fluoroquinolone use (AOR, 3.39; 95% CI, 1.50, 7.66), and (3) prior extended-spectrum cephalosporin use (AOR, 2.55; 95% CI, 1.18, 5.52). Compared with samples from other anatomic locations, K. pneumoniae isolates from blood samples were less likely to harbor KPC (AOR, 0.33; 95% CI, 0.12, 0.86). KPC-producing K. pneumoniae was independently associated with in-hospital mortality (AOR, 3.60; 95% CI, 1.87–6.91). CONCLUSIONS KPC-producing K. pneumoniae is an emerging pathogen associated with significant mortality. Our findings highlight the urgent need to develop strategies for prevention and infection control. Limiting use of certain antimicrobials, specifically fluoroquinolones and cephalosporins, use may be effective strategies. PMID:19860564

  20. Characterization of Streptomyces MITKK-103, a newly isolated actinomycin X2-producer.

    PubMed

    Kurosawa, K; Bui, V P; VanEssendelft, J L; Willis, L B; Lessard, P A; Ghiviriga, I; Sambandan, T G; Rha, C K; Sinskey, A J

    2006-08-01

    A new actinomycete strain designated MITKK-103 was isolated from the soil of a flowerpot using a humic acid agar medium. The newly isolated strain was able to produce a large amount of actinomycin X2 even under nonoptimized growing conditions and serves as a promising source of this antibiotic. Actinomycin X2 has higher cytotoxicity toward cultured human leukemia (HL-60) cells than does actinomycin D, and it induces cell death via apoptosis. A nearly complete 16S ribosomal DNA (rDNA) sequence from the isolate was determined and found to have high identity (98.5-100%) with Streptomyces galbus, Streptomyces griseofuscus, and Streptomyces padanus, indicating that MITKK-103 belongs to the genus Streptomyces. The isolate clustered with species belonging to the S. padanus clade in a 16S-rDNA-based phylogenetic tree and showed 75% overall homology to S. padanus ATCC 25646 in DNA-DNA relatedness analysis. Although the growth of the isolate was somewhat different from the three species mentioned, the strain MITKK-103 most closely resembles S. padanus on the basis of the morphological and phenotypic characteristics, phylogenetic analysis, and genotypic data. As such, this is the first report of a strain of S. padanus capable of producing actinomycins.

  1. Characterization of Five Fungal Endophytes Producing Cajaninstilbene Acid Isolated from Pigeon Pea [Cajanus cajan (L.) Millsp.

    PubMed Central

    Zu, Yuan Gang; Fu, Yu Jie; Wang, Wei; Luo, Meng; Efferth, Thomas

    2011-01-01

    Five fungal endophytes (K4, K5, K6, K9, K14) producing Cajaninstilbene acid (CSA, 3-hydroxy-4-prenyl-5-methoxystilbene-2-carboxylic acid) were isolated from the roots of pigeon pea [Cajanus cajan (L.) Millsp.]. CSA is responsible for the prominent pharmacological activities in pigeon pea. The amount of CSA in culture solution varied among the five fungal endophytes. K4 produced the highest levels of CSA (1037.13 µg/L) among the endophytes tested after incubation for five days. Both morphological characteristics and molecular methods were used for species identification of fungal endophytes. The five endophytic isolates were characterized by analyzing the internal transcribed spacer (ITS) rRNA and β-tubulin genes. The K4, K5, K9 and K14 strains isolated from pigeon pea roots were found to be closely related to the species Fusarium oxysporum. K6 was identified as Neonectria macrodidym. The present study is the first report on the isolation and identification of fungal endophytes producing CSA in pigeon pea. The study also provides a scientific base for large scale production of CSA. PMID:22102911

  2. A ten-year surveillance study of carbapenemase-producing Klebsiella pneumoniae in a tertiary care Greek university hospital: predominance of KPC- over VIM- or NDM-producing isolates.

    PubMed

    Spyropoulou, Aikaterini; Papadimitriou-Olivgeris, Matthaios; Bartzavali, Christina; Vamvakopoulou, Sophia; Marangos, Markos; Spiliopoulou, Iris; Anastassiou, Evangelos D; Christofidou, Myrto

    2016-03-01

    Resistance patterns and carbapenemase gene presence among Klebsiella pneumoniae isolates from the University General Hospital of Patras, Greece during a ten-year period were analysed under a surveillance programme for multi-drug-resistant bacteria. From 2005 to 2014, K. pneumoniae isolates from clinically significant specimens were identified by the Vitek 2 Advanced Expert System. Antibiotic susceptibility testing was performed by the agar disc diffusion method and Etest. The strains were tested for the presence of blaVIM, blaIMP, blaKPC, blaNDM and blaOXA-48 genes by PCR. PFGE of chromosomal Xbal DNA digests was performed. A total of 3449 K. pneumoniae isolates were recovered during the last decade. Among them, 1668 (48 %) were carbapenemase-producing: 1333 (80%) K. pneumoniae carbapenemase (KPC)-, 286 (17%) Verona imipenemase (VIM), 45 (3%) KPC- and VIM-, and four New Delhi metallo-beta-lactamase (NDM)-producing. Their resistance rates to gentamicin, colistin and tigecycline were 41%, 23% and 16%, respectively. VIM-producing K. pneumoniae were isolated in 2005 and since 2008 have been endemic. KPC-producing K. pneumoniae (KPC-Kp) isolates were introduced in 2008 and until now represent the predominant carbapenemase-producing K. pneumoniae in our institution. PFGE of 97 KPC-Kp strains identified three types: A, 84 (87%); B, 11 (11%); and E, two (2%). Eleven co-producing KPC and VIM K. pneumoniae isolates belonged to PFGE B. The four NDM-positives were classified to type F. The number of K. pneumoniae bacteraemias increased during the study period, which may be solely attributed to the increase of carbapenemase-producing isolates. The threat of carbapenemase-producing K. pneumoniae emphasizes the urgent need for implementation of infection control measures and budgetary allocations to infection control.

  3. Antimicrobial activity of bacteriocin-producing lactic acid bacteria isolated from cheeses and yogurts.

    PubMed

    Yang, En; Fan, Lihua; Jiang, Yueming; Doucette, Craig; Fillmore, Sherry

    2012-09-10

    The biopreservation of foods using bacteriocinogenic lactic acid bacteria (LAB) isolated directly from foods is an innovative approach. The objectives of this study were to isolate and identify bacteriocinogenic LAB from various cheeses and yogurts and evaluate their antimicrobial effects on selected spoilage and pathogenic microorganisms in vitro as well as on a food commodity.LAB were isolated using MRS and M17 media. The agar diffusion bioassay was used to screen for bacteriocin or bacteriocin-like substances (BLS) producing LAB using Lactobacillus sakei and Listeria innocua as indicator organisms. Out of 138 LAB isolates, 28 were found to inhibit these bacteria and were identified as strains of Enterococcus faecium, Streptococcus thermophilus, Lactobacillus casei and Lactobacillus sakei subsp. sakei using 16S rRNA gene sequencing. Eight isolates were tested for antimicrobial activity at 5°C and 20°C against L. innocua, Escherichia coli, Bacillus cereus, Pseudomonas fluorescens, Erwinia carotovora, and Leuconostoc mesenteroides subsp. mesenteroides using the agar diffusion bioassay, and also against Penicillium expansum, Botrytis cinerea and Monilinia frucitcola using the microdilution plate method. The effect of selected LAB strains on L. innocua inoculated onto fresh-cut onions was also investigated.Twenty percent of our isolates produced BLS inhibiting the growth of L. innocua and/or Lact. sakei. Organic acids and/or H2O2 produced by LAB and not the BLS had strong antimicrobial effects on all microorganisms tested with the exception of E. coli. Ent. faecium, Strep. thermophilus and Lact. casei effectively inhibited the growth of natural microflora and L. innocua inoculated onto fresh-cut onions. Bacteriocinogenic LAB present in cheeses and yogurts may have potential to be used as biopreservatives in foods.

  4. Antimicrobial activity of bacteriocin-producing lactic acid bacteria isolated from cheeses and yogurts

    PubMed Central

    2012-01-01

    The biopreservation of foods using bacteriocinogenic lactic acid bacteria (LAB) isolated directly from foods is an innovative approach. The objectives of this study were to isolate and identify bacteriocinogenic LAB from various cheeses and yogurts and evaluate their antimicrobial effects on selected spoilage and pathogenic microorganisms in vitro as well as on a food commodity. LAB were isolated using MRS and M17 media. The agar diffusion bioassay was used to screen for bacteriocin or bacteriocin-like substances (BLS) producing LAB using Lactobacillus sakei and Listeria innocua as indicator organisms. Out of 138 LAB isolates, 28 were found to inhibit these bacteria and were identified as strains of Enterococcus faecium, Streptococcus thermophilus, Lactobacillus casei and Lactobacillus sakei subsp. sakei using 16S rRNA gene sequencing. Eight isolates were tested for antimicrobial activity at 5°C and 20°C against L. innocua, Escherichia coli, Bacillus cereus, Pseudomonas fluorescens, Erwinia carotovora, and Leuconostoc mesenteroides subsp. mesenteroides using the agar diffusion bioassay, and also against Penicillium expansum, Botrytis cinerea and Monilinia frucitcola using the microdilution plate method. The effect of selected LAB strains on L. innocua inoculated onto fresh-cut onions was also investigated. Twenty percent of our isolates produced BLS inhibiting the growth of L. innocua and/or Lact. sakei. Organic acids and/or H2O2 produced by LAB and not the BLS had strong antimicrobial effects on all microorganisms tested with the exception of E. coli. Ent. faecium, Strep. thermophilus and Lact. casei effectively inhibited the growth of natural microflora and L. innocua inoculated onto fresh-cut onions. Bacteriocinogenic LAB present in cheeses and yogurts may have potential to be used as biopreservatives in foods. PMID:22963659

  5. Characterization of yeasts isolated from artisanal short-ripened cows' cheeses produced in Galicia (NW Spain).

    PubMed

    Atanassova, M R; Fernández-Otero, C; Rodríguez-Alonso, P; Fernández-No, I C; Garabal, J I; Centeno, J A

    2016-02-01

    A total of 143 presumptive yeast isolates were obtained from the predominant microflora of 21 short-ripened starter-free raw cow's milk cheeses made in Galicia (NW Spain), and the following 68 isolates were identified by both genotyping and sequencing methods: Yarrowia lipolytica (21 isolates), Kluyveromyces lactis (18), Debaryomyces hansenii (11), Pichia guilliermondii (11), Pichia fermentans (4) and Saccharomyces cerevisiae (3). Of these, Y. lipolytica and K. lactis displayed the strongest extracellular proteolytic activity on skim milk agar, and none of the D. hansenii isolates showed any activity on this medium. Y. lipolytica also displayed the highest lipolytic activity on Tween 80 and on tributyrin. This species, which was characterized by production of butanoic acid, free fatty acid esters and sulfur compounds in pasteurized whole milk, was responsible for rancid and cheesy flavors. K. lactis mainly produced acetaldehyde, ethanol, branched chain aldehydes and alcohols, and acetic acid esters, which were responsible for alcoholic, fruity and acetic notes. The volatile profiles of D. hansenii were rather limited and characterized by high levels of methyl ketones. Most of the yeast isolates were described as tryptamine producers, although low concentrations of histamine were produced by five Y. lipolytica and two P. fermentans isolates. We conclude that selected Y. lipolytica strains could be used as adjunct cultures in the manufacture of Arzúa-Ulloa and Tetilla cheeses, and selected K. lactis strains could be used as co-starters in the manufacture of acid curd Cebreiro cheese, thus contributing to the sensory quality and typicality of the cheeses.

  6. Characterization of some efficient cellulase producing bacteria isolated from paper mill sludges and organic fertilizers

    PubMed Central

    Maki, Miranda L; Broere, Michael; Leung, Kam Tin; Qin, Wensheng

    2011-01-01

    The wide variety of bacteria in the environment permits screening for more efficient cellulases to help overcome current challenges in biofuel production. This study focuses on the isolation of efficient cellulase producing bacteria found in organic fertilizers and paper mill sludges which can be considered for use in large scale biorefining. Pure isolate cultures were screened for cellulase activity. Six isolates: S1, S2, S3, S4, E2, and E4, produced halos greater in diameter than the positive control (Cellulomonas xylanilytica), suggesting high cellulase activities. A portion of the 16S rDNA genes of cellulase positive isolates were amplified and sequenced, then BLASTed to determine likely genera. Phylogenetic analysis revealed genera belonging to two major Phyla of Gram positive bacteria: Firmicutes and Actinobacteria. All isolates were tested for the visible degradation of filter paper; only isolates E2 and E4 (Paenibacillus species) were observed to completely break down filter paper within 72 and 96 h incubation, respectively, under limited oxygen condition. Thus E2 and E4 were selected for the FP assay for quantification of total cellulase activities. It was shown that 1% (w/v) CMC could induce total cellulase activities of 1652.2±61.5 and 1456.5±30.7 μM of glucose equivalents for E2 and E4, respectively. CMC could induce cellulase activities 8 and 5.6X greater than FP, therefore CMC represented a good inducing substrate for cellulase production. The genus Paenibacillus are known to contain some excellent cellulase producing strains, E2 and E4 displayed superior cellulase activities and represent excellent candidates for further cellulase analysis and characterization. PMID:21969070

  7. Human clinical isolates of Corynebacterium diphtheriae and Corynebacterium ulcerans collected in Canada from 1999 to 2003 but not fitting reporting criteria for cases of diphtheria.

    PubMed

    Dewinter, Leanne M; Bernard, Kathryn A; Romney, Marc G

    2005-07-01

    A 5-year collection of Corynebacterium diphtheriae and Corynebacterium ulcerans human clinical isolates yielded nine isolates from blood cultures of patients with invasive infections, stressing the importance of C. diphtheriae as a serious blood-borne pathogen. Seven percent of C. diphtheriae and 100% of C. ulcerans isolates produced diphtheria toxin, demonstrating that toxigenic corynebacteria continue to circulate.

  8. Isolation and characteristics of a skatole-producing Lactobacillus sp. from the bovine rumen.

    PubMed Central

    Yokoyama, M T; Carlson, J R; Holdeman, L V

    1977-01-01

    A bacterium that is capable of decarboxylating indoleacetic acid to skatole (3-methylindole) has been isolated from an L-tryptophan enrichment of bovine rumen fluid. The bacterium is a gram-positive, nonmotile, nonsporeforming rod. It is an obligate anaerobe, and strains predominatly produce D-(-)-lactic acid, with smaller amounts of L-(+)-lactic acid and acetic acid, from sugar. All four strains isolated gave a negative reaction to the indole test because they cannot form skatole directly from tryptophan. This is the first report of indoleacetic acid decarboxylation to skatole in pure culture and the demonstration of skatole production by a Lactobacillus species. Images PMID:563703

  9. Molecular epidemiology of Staphylococcus aureus isolates at different sites in the milk producing dairy farms

    PubMed Central

    Souza, Viviane; Nader Filho, Antonio; de Castro Melo, Poliana; Ferraudo, Guilherme Moraes; Antônio Sérgio, Ferraudo; de Oliveira Conde, Sandra; Fogaça Junior, Flavio Augusto

    2012-01-01

    The epidemiological relationships between isolated Staphylococcus aureus strains in milk samples of dairy cows, reagent to California Mastitis Test, individual and group milk was demonstrated in different sites of the production fluxogram, in 12 milk-producing farms in the Gameleira region, municipality of Sacramento MG Brazil, so that localization and transmission modes may be identified. Two hundred and forty-four strains out of 446 samples collected at several sites were isolated and bio-chemically characterized as coagulase-positive staphylococcus. Specific chromosome DNA fragment of the species Staphylococcus aureus was amplified to 106 strains and 103 underwent (PFGE). Samples’ collection sites with the highest isolation frequency of Staphylococcus aureus strains comprised papillary ostia (31.1%), CMT-reagent cow milk (21.7%), mechanical milking machines’ insufflators (21,7%), milk in milk pails (6.6%) and the milk in community bulk tanks (5.6%). Genetic heterogeneity existed among the isolated 103 Staphylococcus aureus strains, since 32 different pulse-types were identified. Pulse-type 1 had the highest similarity among the isolated strains within the different sites of the milk-production fluxogram. Highest occurrence of pulsetype 1 isolates of Staphylococcus aureus strains was reported in samples collected from the papillary ostia (10.6%), followed by milk samples from CMT-reagent dairy cows (5.8%) and mechanical milking machine insufflators (3.8%). The above shows the relevance of these sites in the agents’ transmission mechanism within the context of the farms investigated. PMID:24031997

  10. Molecular epidemiology of Staphylococcus aureus isolates at different sites in the milk producing dairy farms.

    PubMed

    Souza, Viviane; Nader Filho, Antonio; de Castro Melo, Poliana; Ferraudo, Guilherme Moraes; Antônio Sérgio, Ferraudo; de Oliveira Conde, Sandra; Fogaça Junior, Flavio Augusto

    2012-10-01

    The epidemiological relationships between isolated Staphylococcus aureus strains in milk samples of dairy cows, reagent to California Mastitis Test, individual and group milk was demonstrated in different sites of the production fluxogram, in 12 milk-producing farms in the Gameleira region, municipality of Sacramento MG Brazil, so that localization and transmission modes may be identified. Two hundred and forty-four strains out of 446 samples collected at several sites were isolated and bio-chemically characterized as coagulase-positive staphylococcus. Specific chromosome DNA fragment of the species Staphylococcus aureus was amplified to 106 strains and 103 underwent (PFGE). Samples' collection sites with the highest isolation frequency of Staphylococcus aureus strains comprised papillary ostia (31.1%), CMT-reagent cow milk (21.7%), mechanical milking machines' insufflators (21,7%), milk in milk pails (6.6%) and the milk in community bulk tanks (5.6%). Genetic heterogeneity existed among the isolated 103 Staphylococcus aureus strains, since 32 different pulse-types were identified. Pulse-type 1 had the highest similarity among the isolated strains within the different sites of the milk-production fluxogram. Highest occurrence of pulsetype 1 isolates of Staphylococcus aureus strains was reported in samples collected from the papillary ostia (10.6%), followed by milk samples from CMT-reagent dairy cows (5.8%) and mechanical milking machine insufflators (3.8%). The above shows the relevance of these sites in the agents' transmission mechanism within the context of the farms investigated.

  11. First Description of KPC-2-Producing Klebsiella oxytoca Isolated from a Pediatric Patient with Nosocomial Pneumonia in Venezuela

    PubMed Central

    Labrador, Indira

    2014-01-01

    During the last decade, carbapenem resistance has emerged among clinical isolates of the Enterobacteriaceae family. This has been increasingly attributed to the production of β-lactamases capable of hydrolyzing carbapenems. Among these enzymes, Klebsiella pneumoniae carbapenemases (KPCs) are the most frequently and clinically significant class-A carbapenemases. In this report, we describe the first nosocomial KPC-2-producing K. oxytoca isolated from a pediatric patient with pneumonia admitted to the intensive care unit at The Andes University Hospital, Mérida, Venezuela. This strain was resistant to several antibiotics including imipenem, ertapenem, and meropenem but remained susceptible to ciprofloxacin, colistin, and tigecycline. Conjugation assays demonstrated the transferability of all resistance determinants, except aminoglycosides. The isolate LMM-SA26 carried a ~21 kb conjugative plasmid that harbored the blaKPC-2, blaCTX-M-8, and blaTEM-15 genes. Although carbapenem resistance in the Enterobacteriaceae is still unusual in Venezuela, KPCs have a great potential to spread due to their localization on mobile genetic elements. Therefore, rapid detection of KPC-carrying bacteria with phenotypic and confirmatory molecular tests is essential to establish therapeutic options and effective control measures. PMID:25405043

  12. Molecular epidemiology of Italian clinical Cryptococcus neoformans var. grubii isolates.

    PubMed

    Cogliati, Massimo; Zamfirova, Ralika R; Tortorano, Anna Maria; Viviani, Maria Anna

    2013-07-01

    Cryptococcus neoformans variety grubii is the major etiological agent of cryptococcal meningitis in both immunocompromised and immunocompetent patients. The current PCR-based molecular methods are not sufficient to discriminate among the different populations of this yeast. Therefore, the aim of the present study was to investigate the genotypes of the Italian clinical C. neoformans var. grubii isolates by multilocus sequence typing (MLST). A total of 53 isolates, each representative of a single case, were studied. Genotyping was performed using the ISHAM Cryptococcus MLST consensus scheme and the results were compared to the publically available global C. neoformans var. grubii MLST dataset. A total of 16 genotypes were identified; 14 were new genotypes, one was identical to sequence type (ST) ST81, which had been previously reported from Thailand, and one to ST23 already identified in Uganda, the USA and Korea. Sequence type ST61 was the most numerous, including 16 isolates. Network phylogenetic analysis showed that the Italian isolates could be divided into at least three clusters with similarities with those recovered in Africa, Asia and Americas. Distribution of the STs among the isolates could not be correlated to the hospital in which they were recovered or to the HIV status of the patients. The majority of the isolates belonged to the molecular type VNI; three belonged to the rare molecular type VNII and one to the VNB group, which until now had not been described in Europe. The results reveal that the Italian C. neoformans var. grubii population presents a distinct variability, displaying a high number of new genotypes, and probably recombines sexually.

  13. Current state of purification, isolation and analysis of bacteriocins produced by lactic acid bacteria.

    PubMed

    Kaškonienė, Vilma; Stankevičius, Mantas; Bimbiraitė-Survilienė, Kristina; Naujokaitytė, Gintarė; Šernienė, Loreta; Mulkytė, Kristina; Malakauskas, Mindaugas; Maruška, Audrius

    2017-02-01

    The scientific interest for the search of natural means of microbial inhibitors has not faded for several years. A search of natural antibiotics, so-called bacteriocins which are produced by lactic acid bacteria (LAB), gains a huge attention of the scientists in the last century, in order to reduce the usage of synthetic food additives. Pure bacteriocins with wide spectra of antibacterial activity are promising among the natural biopreservatives. The usage of bacteriocin(s) producing LAB as starter culture for the fermentation of some food products, in order to increase their shelf-life, when synthetic preservatives are not allowable, is also possible. There are a lot of studies focusing on the isolation of new bacteriocins from traditional fermented food, dairy products and other foods or sometimes even from unusual non-food matrices. Bacteriocins producing bacteria have been isolated from different sources with the different antibacterial activity against food-borne microorganisms. This review covers the classification of bacteriocins, diversity of sources of bacteriocin(s) producing LAB, antibacterial spectra of isolated bacteriocins and analytical methods for the bacteriocin purification and analysis within the last 15 years.

  14. Extended-Spectrum-β-Lactamase-Producing Enterobacteriaceae Isolated from Vegetables Imported from the Dominican Republic, India, Thailand, and Vietnam

    PubMed Central

    Zurfluh, Katrin; Nüesch-Inderbinen, Magdalena; Morach, Marina; Zihler Berner, Annina; Hächler, Herbert

    2015-01-01

    To examine to what extent fresh vegetables imported into Switzerland represent carriers of extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae, 169 samples of different types of fresh vegetables imported into Switzerland from the Dominican Republic, India, Thailand, and Vietnam were analyzed. Overall, 25.4% of the vegetable samples yielded one or more ESBL-producing Enterobacteriaceae, 78.3% of which were multidrug resistant. Sixty isolates were obtained: Escherichia coli, 26; Klebsiella pneumoniae, 26; Enterobacter cloacae, 6; Enterobacter aerogenes, 1; and Cronobacter sakazakii, 1. We found 29 isolates producing CTX-M-15, 8 producing CTX-M-14, 7 producing CTX-M-55, 3 producing CTX-M-65, 1 each producing CTX-M-1, CTX-M-3, CTX-M-27, and CTX-M-63, 5 producing SHV-2, 3 producing SHV-12, and 1 producing SHV-2a. Four of the E. coli isolates belonged to epidemiologically important clones: CTX-M-15-producing B2:ST131 (1 isolate), D:ST405 (1 isolate), and D:ST38 (2 isolates). One of the D:ST38 isolates belonged to the extraintestinal enteroaggregative E. coli (EAEC) D:ST38 lineage. Two of the K. pneumoniae isolates belonged to the epidemic clones sequence type 15 (ST15) and ST147. The occurrence of antibiotic-resistant pathogenic and commensal Enterobacteriaceae in imported agricultural foodstuffs constitutes a source of ESBL genes and a concern for food safety. PMID:25724954

  15. Characterization of N-Acylhomoserine Lactones Produced by Bacteria Isolated from Industrial Cooling Water Systems.

    PubMed

    Okutsu, Noriya; Morohoshi, Tomohiro; Xie, Xiaonan; Kato, Norihiro; Ikeda, Tsukasa

    2015-12-30

    The cooling water systems are used to remove heat generated in the various industries. Biofouling of the cooling water systems causes blocking of condenser pipes and the heat exchanger tubes. In many Gram-negative bacteria, N-acylhomoserine lactone (AHL) are used as quorum-sensing signal molecule and associated with biofilm formation. To investigate the relationship between quorum sensing and biofouling in the cooling water system, we isolated a total of 192 bacterial strains from the five cooling water systems, and screened for AHL production. Seven isolates stimulated AHL-mediated purple pigment production in AHL reporter strain Chromobacterium violaceum CV026 or VIR07. Based on their 16S rRNA gene sequences, AHL-producing isolates were assigned to Aeromonas hydrophila, Lysobacter sp., Methylobacterium oryzae, and Bosea massiliensis. To the best of our knowledge, B. massiliensis and Lysobacter sp. have not been reported as AHL-producing species in the previous researches. AHLs extracted from the culture supernatants of B. massiliensis and Lysobacter sp. were identified by liquid chromatography-mass spectrometry. AHLs produced by B. massiliensis were assigned as N-hexanoyl-L-homoserine lactone (C6-HSL), N-(3-oxohexanoyl)-L-homoserine lactone (3-oxo-C6-HSL), and N-(3-oxooctanoyl)-L-homoserine lactone (3-oxo-C8-HSL). AHLs produced by Lysobacter sp. were assigned as N-decanoyl-L-homoserine lactone (C10-HSL) and N-(3-oxodecanoyl)-L-homoserine lactone (3-oxo-C10-HSL). This is the first report of identification of AHLs produced by B. massiliensis and Lysobacter sp. isolated from the cooling water system.

  16. Genotyping of clinical isolates of Acanthamoeba genus in Venezuela.

    PubMed

    Wagner, Carolina; Reyes-Batlle, María; Ysea, María Alejandra Vethencourt; Pérez, Mónica V Galindo; de Rondón, Carmen Guzmán; Paduani, Anaibeth J Nessi; Pérez, Angelyseb Dorta; López-Arencibia, Atteneri; Sifaoui, Ines; de Galindo, María Virginia Pérez; de Suárez, Eva Pérez; Martínez-Carretero, Enrique; Valladares, Basilio; Piñero, José E; Lorenzo-Morales, Jacob

    2016-12-01

    Free-living amoebae of Acanthamoeba genus are opportunistic pathogens distributed worldwide. Strains included in this genus are causative agents of a fatal encephalitis and a sight-threating keratitis in humans and other animals. In this study, 550 clinical samples which were collected between 1984 and 2014 from different patients with suspected infections due to Acanthamoeba were initially screened for the presence of this amoebic genus at the Laboratorio de Amibiasis-Escuela de Bioanálisis at the Universidad Central de Venezuela. Samples were cultured in 2% Non-Nutrient agar plates seeded with a layer of heat killed Escherichia coli. From the 550 clinical samples included in this study, 18 of them were positive for Acanthamoeba genus after culture identification. Moreover, positive samples were confirmed after amplification of the Diagnostic Fragment 3 (DF3) of the Acanthamoeba18S rDNA genus and sequencing was carried out in order to genotype the isolated strains of Acanthamoeba. Furthermore, the pathogenic potential of the strains was checked by performing thermotolerance and osmotolerance assays. Sequencing of the DF3 region resulted in the identification of genotype T4 in all the isolated strains. Moreover, most isolates were thermotolerant or both thermotolerant and osmotolerant and thus were classified as potentially pathogenic strains. To the best of our knowledge, this is the first report on the molecular characterization at the genotype level of Acanthamoeba strains in Venezuela.

  17. Survey of CTX-M Gene Frequency in Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae Isolates Using the Combination Disk and PCR Methods in Ahvaz, Iran

    PubMed Central

    Moosavian, Mojtaba; Ahmadkhosravy, Nazanin

    2016-01-01

    Background A common mechanism of resistance to beta-lactam antibiotics is the production of beta-lactamase by Gram-negative bacteria. Recently, nonderivative extended-spectrum beta-lactamases (ESBLs) from the TEM and SHV enzymes, such as CTX-M, that were related to different geographical regions have been recognized. Objectives The aim of this study was to determine the frequency of the CTX-M gene in ESBL-producing Enterobacteriaceae isolates in hospitalized patients in the teaching hospitals of Ahvaz, Iran. Methods Enterobacteriaceae isolates from clinical specimens (other than stool), such as wounds, blood, urine, trachea, discharge, and abscess, were collected and examined. All the isolates were identified using standard biochemical tests. The combination test was carried out based on CLSI criteria for the phenotypic detection of ESBL-producing isolates. After DNA extraction, the CTX-M and CTX-M-1 genes were amplified using PCR among phenotypically positive ESBL isolates. Results Among 240 Enterobacteriaceae isolates, Escherichia coli and Enterobacter were the most common isolates with 171 (71.3%) and 65 (27.1%), respectively. The combination test results also showed that 108 (45%) Enterobacteriaceae isolates were phenotypic ESBL producers, but 104 (96%) isolates were positive for the blaCTX-M gene and 99 (92%) were positive for the blaCTX-M-1 gene according to the PCR method. Conclusions The results of this study phenotypically and genotypically confirmed the high frequency of ESBL-producing strains, such as the CTX-M and CTX-M-1 genes, among Enterobacteriaceae isolates in our region. Therefore, use of antibiotic susceptibility testing for the detection of ESBL isolates prior to the prescription of beta-lactam antibiotics is recommended. This could help prevent the spread of bacteria strains that are resistant to beta-lactam antibiotics. PMID:28138376

  18. [Extended-spectrum beta-lactamase (ESBL) produced by Escherichia coli and Klebsiella pneumoniae isolated from Teikyou University Hospital--the first report].

    PubMed

    Kawakami, S; Ono, Y; Yamamoto, M; Matumura, M; Okamoto, R; Inoue, M; Miyazawa, Y

    1999-11-01

    We studied the cefotaxime (CTX)-resistant (MIC > or = 32 micrograms/ml) clinical isolates of E. coli and K. pneumoniae in Teikyo University Hospital from 1990 to 1996. The incidence of CTX-resistant isolates was 0.4% (6/1,282) in E. coli and 0.6% (7/1,044) in K. pneumoniae, in 1990. In 1995, the incidence of CTX-resistance increased to 1.7% (50/2,910) in E. coli (p = 0.0013) and 7.2% (144/1,996) in K. pneumoniae (p < 0.0001). These species have been detected in the stool (86 isolates), urine (59 isolates), sputum (15 isolates), pus (15 isolates), throat (10 isolates) and others (12 isolates) in 1995. MIC50 of ampicillin (ABPC), ABPC with clavlanic acid (CVA) 5 micrograms/ml, piperacillin (PIPC), PIPC with CVA 5 micrograms/ml, ceftazidime, CTX, ceftizoxime, cefpodoxime, cefepime, aztreonam, cefmetazole, latamoxef, and imipenem used against 33 isolates (11 isolates of E. coli, 22 isolates of K. pneumoniae), which were detected in 1996-1997, was > 512 micrograms/ml, 8 micrograms/ml, > 512 micrograms/ml, 8 micrograms/ml, 4 micrograms/ml, > 512 micrograms/ml, 16 micrograms/ml, > 512 micrograms/ml, 256 micrograms/ml, 32 micrograms/ml, 2 micrograms/ml, 0.25 microgram/ml and 0.25 microgram/ml, respectively. This susceptibility pattern were very similar to the Toho-1 type beta-lactamases producing strains.

  19. The isolation of Candida rugosa and Candida mesorugosa from clinical samples in Ghana.

    PubMed

    Adjapong, Gloria; Bartlett, Michael; Hale, Marie; Garrill, Ashley

    2016-03-01

    Members of the Candida rugosa species complex have been described as emerging fungal pathogens and are responsible for a growing number of Candida infections. In this communication we report the isolation of Candida rugosa and Candida mesorugosa in Ghana. To the best of our knowledge this is the first description of this species complex from a clinical setting in Africa.The isolates were identified on the basis of their rRNA gene internal transcribed spacer (ITS) sequences. For one isolate, obtained from sputum, the sequence grouped well with that of C. rugosa. Two other isolates from urine had sequences that grouped with Candida mesorugosa. Morphologically, C. rugosa formed white, wrinkled, and flat colonies on Sabouraud Dextrose Agar (SDA), whereas C. mesorugosa formed white, smooth colonies. On chromogenic medium, the isolates formed small, dry greenish-blue colonies with a pale or white border, similar to C. albicans. The C. rugosa isolate produced pseudohyphae in human serum and on CMA-Tween 80 agar. In contrast, the C. mesorugosa isolates did not generate pseudohyphae in human serum, but generated a few pseudohyphae with abundant blastoconidia on CMA-Tween 80 agar. Growth was observed at 37 °C and 42 °C but not at 45 °C.The two C. mesorugosa isolates had Minimum Inhibitory Concentrations (MICs) of 6 and 48 μg ml(-1) for fluconazole and are thus resistant. The C. rugosa isolate had an MIC of 24 μg ml(-1), indicative of resistance. All three isolates were susceptible to itraconazole and voriconazole (with respective MICs of < 0.125 μg ml(-1)).

  20. In vitro biofilm production of Candida bloodstream isolates: any association with clinical characteristics?

    PubMed

    Pongrácz, Júlia; Benedek, Kálmán; Juhász, Emese; Iván, Miklós; Kristóf, Katalin

    2016-04-01

    Candida spp. are a leading cause of bloodstream infection (BSI) and are associated with high mortality rates. Biofilm production is a virulence factor of Candida spp., and has been linked with poor clinical outcome. The aim of our study was to assess biofilm production of Candida bloodstream isolates at our institute, and to determine whether in vitro biofilm production is associated with any clinical characteristics of infection. During the four-year study period, 93 cases of Candida BSI were analysed. The most frequently isolated species was C. albicans (66.7 %), followed by C. glabrata (9.7 %), C. parapsilosis (9.7 %), C. tropicalis (9.7 %) and C. krusei (4.3 %). Biofilm production was more prevalent among non-albicans Candida spp. (77.4 %) than C. albicans (30.6 %) (P = 0.02). Abdominal surgery was identified as a risk factor of BSI caused by biofilm producing non-albicans Candida isolates. No risk factors predisposing to bloodstream infection caused by a biofilm producing C. albicans isolate were identified. Biofilm production was not verified as a risk factor of mortality.

  1. Detection of Carbapenemases in Clinical Enterobacteriaceae Isolates Using the VITEK AST-N202 Card

    PubMed Central

    Bae, Il Kwon; Kang, Hyun-Kyung; Jang, In-Ho; Lee, Woonhyoung; Kim, Keonhan; Jeong, Seok Hoon; Lee, Kyungwon

    2015-01-01

    Background The rapid and accurate detection of carbapenemase-producing Enterobacteriaceae (CPE) in clinical microbiology laboratories is essential for the treatment and control of infections caused by these microorganisms. This study was performed to evaluate the ability of the VITEK AST-N202 card to detect CPE isolates. Materials and Methods A total of 43 (Klebsiella pneumoniae, n = 37; Escherichia coli, n = 3; and Enterobacter cloacae, n = 3) CPE isolates and 79 carbapenemase-non-producing Enterobacteriaceae (CNE) isolates were included in this study. The CPE isolates harbored KPC-2 (n = 11), KPC-3 (n = 20), GES-5 (n = 5), VIM-2 (n = 2), IMP-1 (n = 1), NDM-1 (n = 2), or OXA-232 (n = 2). Of the 79 CNE isolates, eight K. pneumoniae isolates were resistant to ertapenem, imipenem, and meropenem, while the remaining 71 isolates were susceptible to the carbapenems. Antimicrobial susceptibilities were tested using the VITEK AST-N202 card, and the results were interpreted as positive when the isolates showed resistant or intermediate results. Modified-Hodge tests (MHTs) were performed using ertapenem or meropenem disks for the screening of carbapenemase production. Polymerase chain reaction (PCR) and direct sequencing were used to identify β-lactamase genes. Results Sensitivity of MHT with ertapenem and meropenem disks for the detection of carbapenemase was 81.4% (35/43) and 81.4% (35/43), respectively, and a combination with both antibiotic disks increased the sensitivity to 88.4% (38/43). Specificity of the MHT was 100% (79/79) for the CNE isolates. Sensitivity of ertapenem, imipenem, and meropenem as assessed by the VITEK AST-N202 card was 100% (43/43), 93% (40/43), and 95.3% (41/43), respectively. Specificity (89.8%, 71/79) of the test with each carbapenem was improved to 100% (71/71) when eight carbapenem-resistant CNE isolates were excluded from the testing. Conclusion The VITEK AST-N202 card showed high sensitivity for the detection of carbapenemases in

  2. A newly isolated organic solvent tolerant Staphylococcus saprophyticus M36 produced organic solvent-stable lipase.

    PubMed

    Fang, Yaowei; Lu, Zhaoxin; Lv, Fengxia; Bie, Xiaomei; Liu, Shu; Ding, Zhongyang; Xu, Weifeng

    2006-12-01

    Thirty-eight high lipase activity strains were isolated from soil, seawater, and Brassica napus. Among them, a novel organic solvent tolerant bacterium (strain M36) was isolated from the seawater in Jiangsu, China. Isolate M36 was able to grow at high concentration of benzene or toluene up to 40% (vol/vol), and later identified as Staphylococcus saprophyticus by biochemical test and 16s ribosomal DNA sequence. No work on Staphylococcus producing lipase with organic solvent tolerance has been reported so far. The lipase of strain M36 whose activity in liquid medium was 42 U mL(-1) at 24-h incubation time was stable in the presence of 25% (vol/vol) p-xylene, benzene, toluene, and hexane.

  3. Isolation, identification and optimization of a new extracellular lipase producing strain of Rhizopus sp.

    PubMed

    Kantak, Jayshree B; Bagade, Aditi V; Mahajan, Siddharth A; Pawar, Shrikant P; Shouche, Yogesh S; Prabhune, Asmita Ashutosh

    2011-08-01

    A lipolytic mesophilic fungus which produces lipase extracellularly was isolated from soil. Based on ITS1-5.8S-ITS4 region sequences of ribosomal RNA, it was concluded that the isolate JK-1 belongs to genus Rhizopus and clades with Rhizopus oryzae. The present paper reports the screening, isolation, identification, and optimization of fermentation conditions for the production of lipase (EC 3.1.1.3). Culture conditions were optimized, and the highest lipase production was observed in basal medium with corn steep liquor as nitrogen source and glucose as carbon source. Maximum lipase production was observed at 72 h, which is about 870 U/ml. Optimization of fermentation conditions resulted in 16-fold enhancement in enzyme production.

  4. Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria

    SciTech Connect

    Aydin, Y. Andelib; Aksoy, Nuran Deveci

    2010-06-17

    Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263+-0.02 g cellulose L{sup -1} for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.

  5. Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria

    NASA Astrophysics Data System (ADS)

    Aydin, Y. Andelib; Aksoy, Nuran Deveci

    2010-06-01

    Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263±0.02 g cellulose L-1 for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.

  6. Clinical significance of Aeromonas species isolated from patients with diarrhea.

    PubMed

    Moyer, N P

    1987-11-01

    A total of 248 strains of Aeromonas spp. were isolated from 3,334 human fecal specimens submitted to a state public health laboratory over a 2-year period to be cultured for enteric pathogens. Cary-Blair transport medium, blood ampicillin agar, and alkaline peptone water enrichment provided optimal recovery of Aeromonas spp. A questionnaire requesting clinical and epidemiological information was sent to physicians, who submitted stool samples for testing, with each laboratory report for 107 consecutive stool isolates of Aeromonas spp. The 56 questionnaires which were completed and returned were analyzed to determine the seasonal distribution of illness and the age and sex distribution of patients; characteristic symptoms; and predisposing factors for gastrointestinal disease caused by Aeromonas spp. It was concluded that some A. hydrophila, A. sobria, and A. caviae strains are capable of causing diarrhea and that antibiotic therapy and the drinking of untreated water are significant risk factors for susceptible hosts.

  7. Clinical significance of Aeromonas species isolated from patients with diarrhea.

    PubMed Central

    Moyer, N P

    1987-01-01

    A total of 248 strains of Aeromonas spp. were isolated from 3,334 human fecal specimens submitted to a state public health laboratory over a 2-year period to be cultured for enteric pathogens. Cary-Blair transport medium, blood ampicillin agar, and alkaline peptone water enrichment provided optimal recovery of Aeromonas spp. A questionnaire requesting clinical and epidemiological information was sent to physicians, who submitted stool samples for testing, with each laboratory report for 107 consecutive stool isolates of Aeromonas spp. The 56 questionnaires which were completed and returned were analyzed to determine the seasonal distribution of illness and the age and sex distribution of patients; characteristic symptoms; and predisposing factors for gastrointestinal disease caused by Aeromonas spp. It was concluded that some A. hydrophila, A. sobria, and A. caviae strains are capable of causing diarrhea and that antibiotic therapy and the drinking of untreated water are significant risk factors for susceptible hosts. PMID:3693537

  8. Selection and molecular identification of fungal isolates that produce xylanolytic enzymes.

    PubMed

    Alvarez-Navarrete, M; Reyna López, G E; Flores-García, A; López Gómez, R; Martínez-Pacheco, M M

    2015-07-17

    Xylan is a heteropolysaccharide and its complete hydrolysis involves a complex set of xylanolytic enzymes. Fungal xylanases have been widely used in the holocellulose industry to obtain by-products or for its elimination. The aim of this study was to select and identify filamentous fungi from different ecosystems that produce extracellular xylanases showing biotechnological potential. One hundred three fungal isolates were obtained from orchard, horticultural, and forest ecosystems. The ability of fungi to degrade xylan was measured by quantifying their xylanolytic indices after growth on solid culture media and their extracellular xylanolytic and cellulolytic activities after submerged fermentation. All fungal isolates grew on solid medium supplemented with xylan as the sole carbon source, but only 44% of isolates showed xylanolytic indices greater than 1.0. In submerged fermentation, 39% of the fungi tested showed no cellulolytic activity. Filamentous fungi were chosen from correspondence analysis and were identified by molecular tools using internal transcribed spacers. One of the 9 isolates selected belonged to the Phoma genus and the remaining were from the Fusarium genus. Fusarium solani (isolate 59) showed the highest xylanolytic index (0.964 ± 0.042), rapid growth on solid medium (1.233 ± 0.050 cm/day), significant xylanolytic activity (3.823 ± 0.210 U/mg), and a total deficiency of cellulolytic activity compared to other fungal isolates. In the zymogram, a clear zone was observed, indicating that F. solani possesses at least 1 xylanase. Fusarium solani was selected for its ability to produce extracellular xylanases with biotechnological potential.

  9. Isolation and characterization of tyramine-producing Enterococcus faecium strains from red wine.

    PubMed

    Capozzi, Vittorio; Ladero, Victor; Beneduce, Luciano; Fernández, María; Alvarez, Miguel A; Benoit, Bach; Laurent, Barnavon; Grieco, Francesco; Spano, Giuseppe

    2011-05-01

    Enterococcus faecium strains were isolated from red wines undergoing malolactic fermentation and identified by comparison of their 16S rDNA gene sequences with those included in the GenEMBL Databases. The tyrosine decarboxylase gene was identified in all the strains analysed by PCR using gene-specific primers and the ability to produce tyramine in a synthetic media was analysed by RP-HPLC. Survival of an E. faecium strain was also evaluated in microvinification assays using two different musts with different ethanol concentrations (10% and 12% (v/v)). Tyramine production was monitored during the vinification trials. Our results suggest that E. faecium strains isolated from wine are able to produce tyramine and tolerate wine conditions following a pre-acidic stress.

  10. Draft genome sequences of three NDM-1-producing Enterobacteriaceae species isolated from Brazil.

    PubMed

    Pereira, Polyana Silva; Albano, Rodolpho Mattos; Asensi, Marise Dutra; Carvalho-Assef, Ana Paula D'Alincourt

    2015-06-01

    The emergence of multidrug-resistant Enterobacteriaceae strains producing carbapenemases, such as NDM-1, has become a major public health issue due to a high dissemination capacity and limited treatment options. Here we describe the draft genome of three NDM-1-producing isolates: Providencia rettgeri (CCBH11880), Enterobacter hormaechei subsp. oharae (CCBH10892) and Klebsiella pneumoniae (CCBH13327), isolated in Brazil. Besides blaNDM-1, resistance genes to aminoglycosides [aadA1, aadA2, aac(6')-Ib-cr] and quinolones (qnrA1, qnrB4) were observed which contributed to the multidrug resistance profile. The element ISAba125 was found associated to the blaNDM-1 gene in all strains.

  11. Ionofore antibiotic polynactin produced by Streptomyces sp. 156A isolated from Lake Baikal.

    PubMed

    Shishlyannikova, Tatyana A; Kuzmin, Anton V; Fedorova, Galina A; Shishlyannikov, Sergey M; Lipko, Irina A; Sukhanova, Elena V; Belkova, Natalia L

    2017-03-01

    The potential antibacterial activity of secondary metabolites produced by Streptomyces sp. 156A isolated from Lake Baikal was investigated. The selective liquid-liquid extraction method was applied to obtain a mixture of nactins (polynactin) produced by the strain. The polynactin consisted of nonactin (3%), monactin (18%), dinactin (36%), trinactin (31%) and tetranactin (12%). The compounds were identified by MS/MS, (1)H and (13)C NMR methods. The loss of neutral 184 and 198 Da fragments from a sodiated molecular ion, [M + Na](+), of nactins was observed in the MS/MS spectrum. The polynactin was shown to possess the antibiotic activity against Gram-positive strains including opportunistic strains and strains isolated from various ecosystems of Lake Baikal.

  12. [Taxonomic study of clinic isolates of Trichophyton in Rosario, Argentina].

    PubMed

    Tartabini, Mirta L; Bonino, Guillermo S; Racca, Liliana; Luque, Alicia G

    2013-01-01

    Due to the pleomorphism and cultural variability displayed by species of the genus Trichophyton, the identification methods based solely on morphological features are usually insufficient for their classification. The goal of the present work was to test a set of phenotypic methods in order to identify fungal isolates that belong to the aforementioned genus. These methods were based on a molecular taxonomic technique used as standard. Clinical isolates (56) were used as samples along with 6 reference strains. Macro and micromorphological studies were performed as well as biochemical and physiological tests such as in vitro hair perforation, nutritional requirements in Trichophyton agar media, urease production and growth on bromocresol purple-milk. solids-glucose (BCP-MS-G) agar. Additionally, PCR fingerprinting using the (GACA)4 primer was employed. As a result of the PCR method, specific profiles were observed for Microsporum canis, Epidermophyton floccosum, Trichophyton rubrum and Trichophyton interdigitale. Identical profiles were obtained for Arthroderma benhamiae y Trichophyton erinacei. Of the total number of clinical isolates, 39 matched the T. rubrum profile while 13 corresponded to A. benhamiae and 4 to T. interdigitale. The most useful phenotypic test to differentiate between T. rubrum and T. mentagrophytes complex strains was alkalinization of the BCP-MS-G medium. Phenotypic tests did not allow differentiation among the T. mentagrophytes complex species. On the other hand, the molecular technique allowed characterization of T. rubrum isolates as well as of those observed in our study and included in the T. mentagrophytes complex: T. interdigitale and Trichophyton sp., the anamorph of A. benhamiae.

  13. Isolation and screening of antibiotic producing actinomycetes from soils in Gondar town, North West Ethiopia

    PubMed Central

    Bizuye, Abebe; Moges, Feleke; Andualem, Berhanu

    2013-01-01

    Objective To isolate and screen antibiotic producing actinomycetes from potential soil samples of Gondar town, Ethiopia. Methods Fifteen soil samples were collected, serially diluted and spread on starch casein and oat meal agar supplemented with amoxicillin and cyclohexamide for inhibition of bacteria and fungi, respectively. Cross streak method was used to check antagonistic activity of isolated actinomycetes against test organisms. Solid state fermentation and crude extraction were used for the production of antibiotics from isolates. Agar well diffusion was used for antimicrobial activity of crude extracts against test organisms. Results Three isolates (Ab18, Ab28 and Ab43) have been shown high antagonistic activity during primary screening. Inhibition zones obtained from crude extracts showed significance differences when compared with standard antibiotics tested against test organisms (P<0.05). Inhibition zone of crude extracts from isolate Ab18 against Klebsiella pneumonia ATCC7000603 and Escherichia coli ATCC25922 were (14±1) mm and (35±1) mm, respectively which were strong active when compared to amoxicillin (0 mm) and tetracycline [(13±1) mm for Klebsiella pneumonia ATCC7000603 and (33±1) mm for Escherichia coli ATCC25922]. Crude extracts from isolate Ab18 showed (20±1) mm and (15±1) mm inhibition zones against methicillin resistant Staphylococcus aureus strains 2 (MRSA2) and MRSA4, respectively. Crude extract from isolate Ab43 has shown inhibition zones of (16±1) mm and (17±1) mm against MRSA2 and MRSA4, respectively. Combination of Ab18 and Ab43 has shown high antimicrobial activity (18±1) mm against MRSA2 and MRSA4. Conclusions There was not any scientific report on soil actinomycetes producing antibiotic in the study areas. Therefore, isolation and screening of actinomycetes from such areas in optimum condition may contribute the discovery of new antibiotics. Potent antibiotics from these actinomycetes could contribute a lot to fight against

  14. Characterization of some bacteriocins produced by lactic acid bacteria isolated from fermented foods.

    PubMed

    Grosu-Tudor, Silvia-Simona; Stancu, Mihaela-Marilena; Pelinescu, Diana; Zamfir, Medana

    2014-09-01

    Lactic acid bacteria (LAB) isolated from different sources (dairy products, fruits, fresh and fermented vegetables, fermented cereals) were screened for antimicrobial activity against other bacteria, including potential pathogens and food spoiling bacteria. Six strains have been shown to produce bacteriocins: Lactococcus lactis 19.3, Lactobacillus plantarum 26.1, Enterococcus durans 41.2, isolated from dairy products and Lactobacillus amylolyticus P40 and P50, and Lactobacillus oris P49, isolated from bors. Among the six bacteriocins, there were both heat stable, low molecular mass polypeptides, with a broad inhibitory spectrum, probably belonging to class II bacteriocins, and heat labile, high molecular mass proteins, with a very narrow inhibitory spectrum, most probably belonging to class III bacteriocins. A synergistic effect of some bacteriocins mixtures was observed. We can conclude that fermented foods are still important sources of new functional LAB. Among the six characterized bacteriocins, there might be some novel compounds with interesting features. Moreover, the bacteriocin-producing strains isolated in our study may find applications as protective cultures.

  15. Glycolipids produced by Rouxiella sp. DSM 100043 and isolation of the biosurfactants via foam-fractionation.

    PubMed

    Kügler, Johannes H; Muhle-Goll, Claudia; Hansen, Silla H; Völp, Annika R; Kirschhöfer, Frank; Kühl, Boris; Brenner-Weiss, Gerald; Luy, Burkhard; Syldatk, Christoph; Hausmann, Rudolf

    2015-12-01

    Microorganisms produce a great variety of secondary metabolites that feature surface active and bioactive properties. Those possessing an amphiphilc molecular structure are also termed biosurfactant and are of great interest due to their often unique properties. Rouxiella sp. DSM 100043 is a gram negative enterobacter isolated from peat-bog soil and described as a new biosurfactant producing species in this study. Rouxiella sp. produces glycolipids, biosurfactants with a carbohydrate moiety in its structure. This study characterizes the composition of glycolipids with different hydrophobicities that have been produced during cultivation in a bioreactor and been extracted and purified from separated foam. Using two dimensional nuclear magnetic resonance spectroscopy, the hydrophilic moieties are elucidated as glucose with various acylation sites and as talose within the most polar glycolipids. The presence of 3' hydroxy lauroleic acid as well as myristic and myristoleic acid has been detected.

  16. Isolation and characterization of histamine-producing bacteria from fermented fish products.

    PubMed

    Moon, Jin Seok; Kim, So-Young; Cho, Kyung-Ju; Yang, Seung-Joon; Yoon, Gun-Mook; Eom, Hyun-Ju; Han, Nam Soo

    2013-12-01

    Histamine is mainly produced by microorganisms that are found in fermented foods, and is frequently involved in food poisoning. Two histamine-producing bacteria were isolated from fermented fish products, anchovy sauce, and sand lance sauce by using a histidine decarboxylating medium. The species were identified as Bacillus licheniformis A7 and B. coagulans SL5. Multiplex PCR analysis showed the presence of the conserved histidine decarboxylase (hdc) gene in the chromosome of these bacteria. B. licheniformis A7 and B. coagulans SL5 produced the maximum amount of histamine (22.3±3.5 and 15.1±1.5 mg/L, respectively). As such, they were determined to be potential histamine-producing bacteria among the tested cultures.

  17. Isolation and Antibiogram of Clostridium tetani from Clinically Diagnosed Tetanus Patients.

    PubMed

    Hanif, Hajra; Anjum, Awais; Ali, Naeem; Jamal, Asif; Imran, Muhammad; Ahmad, Bashir; Ali, Muhammad Ishtiaq

    2015-10-01

    Clostridium tetani, the etiologic agent of tetanus, produces a toxin that causes spastic paralysis in humans and other vertebrates. This study was aimed for isolation, identification, and determination of antimicrobial susceptibility of C. tetani from clinically diagnosed tetanus patients. Isolation was done from deep-punctured tissues of the foot and arm injuries of 80 clinically diagnosed tetanus patients from the Pakistan Institute of Medical Sciences hospital. We successfully screened out five C. tetani isolates out of 80 samples based on the strain-specific characteristics confirmed through biochemical testing and toxin production. A disc diffusion method was used for antimicrobial susceptibilities and C. tetani isolates showed susceptibility to cefoperazone, chloramphenicol, metronidazole, penicillin G, and tetracycline, but were found to be resistant to erythromycin and ofloxacin. During animal testing, all the infected mice developed symptoms of tetanus. The results showed that identification of C. tetani is possible using biochemical and molecular tools and that the strains of C. tetani isolated had not developed resistance against the antibiotics most often used for the treatment of tetanus.

  18. Genomic Characterization of Two KPC-Producing Klebsiella Isolates Collected in 1997 in New York City.

    PubMed

    Eilertson, Brandon; Chen, Liang; Chavda, Kalyan D; Kreiswirth, Barry N

    2017-04-01

    Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae have now become a global public health threat. However, the origin of this pandemic and the characterization of pre-2003 blaKPC-harboring plasmids remain unknown. Here we used next-generation sequencing to characterize two KPC-2-producing K. pneumoniae and Kmichiganensis isolates collected from a New York City hospital in 1997. Although identified in two different Klebsiella species, the blaKPC-2 gene was harbored by Tn4401b transposons on two highly similar IncN plasmids.

  19. Draft genome sequence of a GES-5-producing Serratia marcescens isolated in southern Brazil.

    PubMed

    Nodari, Carolina Silva; Siebert, Marina; Matte, Ursula da Silveira; Barth, Afonso Luís

    Serratia marcescens is a Gram-negative rod intrinsically resistant to polymyxins and usually associated with wound, respiratory and urinary tract infections. The whole genome of the first GES-5-producing S. marcescens isolated from a Brazilian patient was sequenced using Ion Torrent PGM System. Besides blaGES-5, we were able to identify genes encoding for other β-lactamases, for aminoglycoside modifying enzymes and for an efflux pump to tetracyclines.

  20. Virulence characterization of Shiga-toxigenic Escherichia coli isolates from wholesale produce.

    PubMed

    Feng, Peter C H; Councell, Terry; Keys, Christine; Monday, Steven R

    2011-01-01

    The 13 Shiga-toxigenic Escherichia coli (STEC) strains isolated from wholesale spinach and lettuce consisted mostly of serotypes that have not been implicated in illness. Among these strains, however, were two O113:H21 that carried virulence genes common to this pathogenic serotype (stx(2), ehxA, saa, and subAB), suggesting that their presence in ready-to-eat produce may be of health concern.

  1. Isolation and characterisation of non-anaerobic butanol-producing symbiotic system TSH06.

    PubMed

    Wang, Genyu; Wu, Pengfei; Liu, Ya; Mi, Shuo; Mai, Shuai; Gu, Chunkai; Wang, Gehua; Liu, Hongjuan; Zhang, Jianan; Børresen, Børre Tore; Mellemsæther, Evy; Kotlar, Hans Kristian

    2015-10-01

    Butanol-producing microorganisms are all obligate anaerobes. In this study, a unique symbiotic system TSH06 was isolated to be capable of producing butanol under non-anaerobic condition. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S ribosomal RNA (rRNA) revealed that two strains coexist in TSH06. The two strains were identical to Clostridium acetobutylicum and Bacillus cereus, respectively. They were isolated individually and named as C. acetobutylicum TSH1 and B. cereus TSH2. C. acetobutylicum TSH1 is a butanol-producing, obligate anaerobic strain. Facultative anaerobic B. cereus TSH2 did not possess the ability of butanol production; however, it offered C. acetobutylicum TSH1 the viability under non-anaerobic condition. Moreover, B. cereus TSH2 enhanced butanol yield and speed of fermentation. TSH06 produced 12.97 g/L butanol and 15.39 g/L total solvent under non-anaerobic condition, which is 25 and 24 %, respectively, higher than those of C. acetobutylicum TSH1. In addition, TSH06 produced butanol faster under non-anaerobic condition than under anaerobic condition. Butanol accounted for more than 80 % of total solvent, which is higher than the known report. TSH06 was stable during passage. In all, TSH06 is a promising candidate for industrialisation of biobutanol with high yield, high butanol proportion, easy-handling and time-saving system. These results demonstrated the potential advantage of symbiosis. This study also provides a promising strategy for butanol fermentation.

  2. Isolation of nisin-producing Lactococcus lactis strains from dry fermented sausages.

    PubMed

    Rodríguez, J M; Cintas, L M; Casaus, P; Horn, N; Dodd, H M; Hernández, P E; Gasson, M J

    1995-02-01

    A total of 4608 lactic acid bacteria (LAB) were isolated from 24 Spanish fermented sausages and screened for bacteriocin production. Two strains, BB24 and G18, produced bacteriocins that inhibited a broad spectrum of Gram-positive bacteria. BB24 and G18 were tentatively identified as Lactococcus lactis by carbohydrate fermentation patterns and other biochemical characteristics. The characterization of their bacteriocins suggested that both could be the well-known lantibiotic nisin. This was confirmed by PCR analysis of their genomic DNA. Nucleotide sequencing revealed that they produced nisin A. The fact that BB24 and G18 were isolated from sausages produced in two different regions of Spain suggests that nisin-producing L. lactis strains may be more widespread in meat products than previously thought. Nisin produced by L. lactis BB24 has been purified to homogeneity by a procedure that included ammonium sulphate precipitation and cation-exchange, hydrophobic-interaction and reverse-phase chromatography. The purification procedure was simple, rapid and reproducible.

  3. Serogroup, virulence, and molecular traits of Vibrio parahaemolyticus isolated from clinical and cockle sources in northeastern Thailand.

    PubMed

    Mala, Wanida; Alam, Munirul; Angkititrakul, Sunpetch; Wongwajana, Suwin; Lulitanond, Viraphong; Huttayananont, Sriwanna; Kaewkes, Wanlop; Faksri, Kiatichai; Chomvarin, Chariya

    2016-04-01

    Vibrio parahaemolyticus is responsible for seafood-borne gastroenteritis worldwide. Isolates of V. parahaemolyticus from clinical samples (n=74) and cockles (Anadara granosa) (n=74) in Thailand were analyzed by serotyping, determination of virulence and related marker genes present, response to antimicrobial agents, and genetic relatedness. Serological analysis revealed 31 different serotypes, 10 of which occurred among both clinical and cockle samples. The clinical isolates commonly included the pandemic serogroup O3:K6, while a few of the cockle isolates exhibited likely pandemic serovariants such as O3:KUT and O4:KUT, but not O3:K6. The pandemic (orf8 gene-positive) strains were more frequently found among clinical isolates (78.4%) than cockle isolates (28.4%) (p<0.001). Likewise, the virulence and related marker genes were more commonly detected among clinical than cockle isolates; i.e., tdh gene (93.2% versus 29.7%), vcrD2 (97.3% versus 23.0%), vopB2 (89.2% versus 13.5%), vopT (98.6% versus 36.5%) (all p<0.001) and trh (10.8% versus 1.4%) (p<0.05). Pulsed-field gel electrophoresis of NotI-digested genomic DNA of 41 randomly selected V. parahaemolyticus isolates representing different serotypes produced 33 pulsotypes that formed 5 different clusters (clonal complexes) (A-E) in a dendrogram. Vibrio parahaemolyticus O3:K6 and likely related pandemic serotypes were especially common among the numerous clinical isolates in cluster C, suggesting a close clonal link among many of these isolates. Most clinical and cockle isolates were resistant to ampicillin. This study indicates that O3:K6 and its likely serovariants based on the PFGE clusters, are causative agents. Seafoods such as cockles potentially serve as a source of virulent V. parahaemolyticus, but further work is required to identify possible additional sources.

  4. Antibiotic resistance pattern among biofilm producing and non producing Proteus strains isolated from hospitalized patients; matter of hospital hygiene and antimicrobial stewardship.

    PubMed

    Shikh-Bardsiri, Houshang; Shakibaie, Mohammad Reza

    2013-11-15

    A retrospective study on antimicrobial susceptibility and biofilm production were carried out for eighty eight strains of Proteus strains isolated from UTI and other hospital samples during April 2011-April 2012. The antibiotic susceptibility was carried out by Kirby-Bauer disk diffusion and MIC by E-test. Biofilm production was measured by microtiter method and confirmed by Scanning electron microscopy. Plasmids from biofilm producing isolates were detected by alkaline lysis technique. From 88 patients infected by proteus species, 58% were female and 42% were mail. The most frequent age range was 20-29 (77.39%) and the least were 60-69 years old (3.4%) (p = 0.05). Eighty one isolates were identified as P. mirabilis while, 7 identified as P. vulgaris. 67.04% [n = 59] of the isolates showed MIC range (16-32 +/- 0.05 microg mL(-1)) to ceftriaxone, 46.59% [n = 41] exhibited least MIC range to chloramphenicol (8-64 +/- 0.08 microg mL(-1)). 31% [n = 28] of the isolates also exhibited MIC range 1-4 microg mL(-1) to ciprofloxacin. 17% [n = 15] of the isolates exhibited strong biofilm while, 6% [n = 6] did not show any biofilm (p < or = 0.05). Plasmid isolation from biofilm producing isolates revealed that stains number 19, 24 and 87' that produced strong biofilm carried similar high M. Wt. plasmid. From above results it can be concluded that the majority of Proteus isolated from UTI patients were belong to P. mirabilis. Ciprofloxacin was the most effective antibiotic for treatment of the infected patients. Limited number of the isolates could produce strong biofilm that were bearing plasmids. Majority of the biofilm producing isolates were also resistance at least to 4 antibiotics routinely prescribed in our hospital.

  5. Identification and characterization of bioemulsifier-producing yeasts isolated from effluents of a dairy industry.

    PubMed

    Monteiro, A S; Bonfim, M R Q; Domingues, V S; Corrêa, A; Siqueira, E P; Zani, C L; Santos, V L

    2010-07-01

    New bioemulsifier-producing yeasts were isolated from the biological wastewater treatment plant of a dairy industry. Of the 31 bioemulsifier-producing strains, 12 showed emulsifying activity after 2months of incubation, with E(24) values ranging from 7% to 78%. However, only Trichosporon loubieri CLV20, Geotrichum sp. CLOA40, and T. montevideense CLOA70 exhibited high emulsion-stabilizing capacity, with E(24) values of 78%, 67%, and 66%, respectively. These isolates were shown to induce a strong emulsion stabilizing activity rather than the reduction of the interfacial tension. These strains exhibited similar growth rates in the exponential growth phase, with a clear acceleration after 24h and stabilization of the activity after 144h. Emulsification and stability properties of the bioemulsifiers were compared to those of commercial surfactants after the addition of NaCl and exposure to temperature of 100 degrees C. The compounds produced by the isolates appeared to be lipid-polysaccharide complexes. Gas chromatograph analysis of the lipidic fraction of the bioemulsifiers from CLV20, CLOA40, and CLOA70 shows the prevalence of (9Z,12Z)-octadeca-9,12-dienoic acid, in concentrations of 42.8%, 25.9%, and 49.8%, respectively. The carbohydrate composition, as determined by GC-MS of their alditol acetate derivatives, showed a predominance of mannose, galactose, xylose and arabinose.

  6. Improving safety of salami by application of bacteriocins produced by an autochthonous Lactobacillus curvatus isolate.

    PubMed

    de Souza Barbosa, Matheus; Todorov, Svetoslav Dimitrov; Ivanova, Iskra; Chobert, Jean-Marc; Haertlé, Thomas; de Melo Franco, Bernadette Dora Gombossy

    2015-04-01

    The aims of this study were to isolate LAB with anti-Listeria activity from salami samples, characterize the bacteriocin/s produced by selected isolates, semi-purify them and evaluate their effectiveness for the control of Listeria monocytogenes during manufacturing of salami in a pilot scale. Two isolates (differentiated by RAPD-PCR) presented activity against 22 out of 23 L. monocytogenes strains for bacteriocin MBSa2, while the bacteriocin MBSa3 inhibited all 23 strains in addition to several other Gram-positive bacteria for both antimicrobials and were identified as Lactobacillus curvatus based on 16S rRNA sequencing. A three-step purification procedure indicated that both strains produced the same two active peptides (4457.9 Da and 4360.1 Da), homlogous to sakacins P and X, respectively. Addition of the semi-purified bacteriocins produced by Lb. curvatus MBSa2 to the batter for production of salami, experimentally contaminated with L. monocytogenes (10(4)-10(5) CFU/g), caused 2 log and 1.5 log reductions in the counts of the pathogen in the product after 10 and 20 days respectively, highlighting the interest for application of these bacteriocins to improve safety of salami during its manufacture.

  7. Composition, Structure and Functional Properties of Protein Concentrates and Isolates Produced from Walnut (Juglans regia L.)

    PubMed Central

    Mao, Xiaoying; Hua, Yufei

    2012-01-01

    In this study, composition, structure and the functional properties of protein concentrate (WPC) and protein isolate (WPI) produced from defatted walnut flour (DFWF) were investigated. The results showed that the composition and structure of walnut protein concentrate (WPC) and walnut protein isolate (WPI) were significantly different. The molecular weight distribution of WPI was uniform and the protein composition of DFWF and WPC was complex with the protein aggregation. H0 of WPC was significantly higher (p < 0.05) than those of DFWF and WPI, whilst WPI had a higher H0 compared to DFWF. The secondary structure of WPI was similar to WPC. WPI showed big flaky plate like structures; whereas WPC appeared as a small flaky and more compact structure. The most functional properties of WPI were better than WPC. In comparing most functional properties of WPI and WPC with soybean protein concentrate and isolate, WPI and WPC showed higher fat absorption capacity (FAC). Emulsifying properties and foam properties of WPC and WPI in alkaline pH were comparable with that of soybean protein concentrate and isolate. Walnut protein concentrates and isolates can be considered as potential functional food ingredients. PMID:22408408

  8. Composition, structure and functional properties of protein concentrates and isolates produced from walnut (Juglans regia L.).

    PubMed

    Mao, Xiaoying; Hua, Yufei

    2012-01-01

    In this study, composition, structure and the functional properties of protein concentrate (WPC) and protein isolate (WPI) produced from defatted walnut flour (DFWF) were investigated. The results showed that the composition and structure of walnut protein concentrate (WPC) and walnut protein isolate (WPI) were significantly different. The molecular weight distribution of WPI was uniform and the protein composition of DFWF and WPC was complex with the protein aggregation. H(0) of WPC was significantly higher (p < 0.05) than those of DFWF and WPI, whilst WPI had a higher H(0) compared to DFWF. The secondary structure of WPI was similar to WPC. WPI showed big flaky plate like structures; whereas WPC appeared as a small flaky and more compact structure. The most functional properties of WPI were better than WPC. In comparing most functional properties of WPI and WPC with soybean protein concentrate and isolate, WPI and WPC showed higher fat absorption capacity (FAC). Emulsifying properties and foam properties of WPC and WPI in alkaline pH were comparable with that of soybean protein concentrate and isolate. Walnut protein concentrates and isolates can be considered as potential functional food ingredients.

  9. Experience of isolated sleep paralysis in clinical practice in Nigeria.

    PubMed

    Ohaeri, J U

    1992-06-01

    The supernatural fears associated with the experience of isolated sleep paralysis in the culture of developing countries is sometimes associated with the evolution of somatic symptoms of psychological origin in patients predisposed to neurotic illness. Patients rarely spontaneously volunteer these fears and doctors pay them scant attention. Illustrative case histories that demonstrate the dynamics of the clinical presentation, as well as the treatment approach, are highlighted. It is hoped that doctors in general medical practice and in psychological medicine in developing countries where belief in supernatural causation of illness is rife will consider these factors in order to provide more effective treatment.

  10. Isolation and characterization of bacteriocin-producing lactic acid bacteria from ready-to-eat food products.

    PubMed

    Kelly, W J; Asmundson, R V; Huang, C M

    1996-12-01

    Lactic acid bacteria isolated from a range of foods sold in ready-to-eat form were screened for bacteriocin production. Twenty-two bacteriocin-producing cultures were isolated from 14 of the 41 foods sampled. Bacteriocin-producing isolates from meat, fish and dairy products were Lactobacillus and Leuconostoc species typically found associated with these products. Most of these isolates gave only a narrow inhibitory spectrum although two showed activity against Listeria monocytogenes. Fruit and vegetable products gave a broader range of organisms but most of the bacteriocin-producing cultures were found to be strains of Lactococcus. Several lactococci produced a nisin-like activity, and showed a broad inhibitory spectrum against the indicator strains tested. The ease with which bacteriocin-producing strains could be isolated implies that they are already being safely consumed in food, and highlights the potential for using bacteriocin-producing cultures for biopreservation, especially in association with minimally processed products.

  11. Isolation, Partial Purification and Characterization of an Antimicrobial Compound, Produced by Bacillus atrophaeus

    PubMed Central

    Ebrahimipour, Gholam Hossein; Khosravibabadi, Zahra; Sadeghi, Hossein; Aliahmadi, Atusa

    2014-01-01

    Background: Antibiotics are usually assumed as secondary metabolites produced during the idiophase of microbial growth, which can kill or inhibit the growth of other microorganisms. Nowadays, indiscriminate use of antibiotics has resulted in resistant microorganisms. Therefore, screening researches on products with antimicrobial activities are necessary. Objectives: To find new antibiotics to defend against pathogenic microorganisms resistant to common antibiotics, the bacterium isolated from skin of the frog called Rana ridibunda was studied for its antimicrobial activities. Materials and Methods: An antibiotic-producing bacterium was isolated from the frog skin. The bacterium was identified based on 16SrDNA sequencing and biochemical and morphological characteristics. Antimicrobial activity of the culture supernatant was examined against laboratorial standard bacteria by disc diffusion and minimum inhibitory concentration (MIC) methods. To characterize the produced antimicrobial compound, the culture supernatant of the bacterium was washed by chloroform and dried at 40°C; then, the antimicrobial substance was extracted by methanol and acetone and detected by bioautography on silica gel plates. Dialysis tube was used to find the molecular weight of this substance. Results: The isolated bacterium was identified as a new strain of Bacillus atrophaeus. The antimicrobial substance exhibited heat stability between 25ºC and 100ºC and was active in a broad pH range from 2.0 to 11.0. The bioautography assay showed that methanol was the optimum solvent for the extraction of antimicrobial substance. The dialysis tube indicated that the antimicrobial substance weight was less than 1 kDa and the compound did not precipitate with ammonium sulfate. Conclusions: This study showed that some properties of antimicrobial substances produced by the GA strain differed from other peptide antibiotics produced by the genus Bacillus such as bacitracin, which increases the likelihood of

  12. Serotypes and Virulence Profiles of Non-O157 Shiga Toxin-Producing Escherichia coli Isolates from Bovine Farms▿

    PubMed Central

    Monaghan, Áine; Byrne, Brian; Fanning, Séamus; Sweeney, Torres; McDowell, David; Bolton, Declan J.

    2011-01-01

    Non-O157 Shiga toxin-producing Escherichia coli (STEC) strains are clinically significant food-borne pathogens. However, there is a dearth of information on serotype prevalence and virulence gene distribution, data essential for the development of public health protection monitoring and control activities for the meat and dairy industries. Thus, the objective of this study was to examine the prevalence of non-O157 STEC on beef and dairy farms and to characterize the isolates in terms of serotype and virulence markers. Bovine fecal samples (n = 1,200) and farm soil samples (n = 600) were collected from 20 farms throughout Ireland over a 12-month period. Shiga toxin-positive samples were cultured and colonies examined for the presence of stx1 and/or stx2 genes by PCR. Positive isolates were serotyped and examined for a range of virulence factors, including eaeA, hlyA, tir, espA, espB, katP, espP, etpD, saa, sab, toxB, iha, lpfAO157/OI-141, lpfAO113, and lpfAO157/OI-154. Shiga toxin and intimin genes were further examined for known variants. Significant numbers of fecal (40%) and soil (27%) samples were stx positive, with a surge observed in late summer-early autumn. One hundred seven STEC isolates were recovered, representing 17 serotypes. O26:H11 and O145:H28 were the most clinically significant, with O113:H4 being the most frequently isolated. However, O2:H27, O13/O15:H2, and ONT:H27 also carried stx1 and/or stx2 and eaeA and may be emerging pathogens. PMID:22003024

  13. Characterization of KPC-2-producing Escherichia coli, Citrobacter freundii, Enterobacter cloacae, Enterobacter aerogenes, and Klebsiella oxytoca isolates from a Chinese Hospital.

    PubMed

    Luo, Yanping; Yang, Jiyong; Ye, Liyan; Guo, Lin; Zhao, Qiang; Chen, Rong; Chen, Yong; Han, Xuelin; Zhao, Jingya; Tian, Shuguang; Han, Li

    2014-08-01

    Twelve nonduplicated KPC-2-producing enterobacterial isolates, including three Escherichia coli, two Citrobacter freundii, two Enterobacter cloacae, four Enterobacter aerogenes, and one Klebsiella oxytoca, were collected from various clinical samples within 18 months (March 2011 to September 2012). Two of the 12 patients died from infections caused by KPC-2-producing pathogens, while the rest of the patients with KPC-2-producing pathogens improved or were cured. The majority of the clinical isolates exhibited a high-level of resistance to oxyimino-cephalosporins and carbapenems, and possessed self-transferable bla(KPC-2)-carrying plasmids with sizes ranging from 20 to 120 kb. Most isolates carried bla(CTX-M) and plasmid-mediated quinolone resistance genes, while some isolates produced 16S rRNA methylases (ArmA or RmtB). The genetic environment of bla(KPC-2) of most clinical strains was consistent with the genetic structure surrounding bla(KPC-2) on the plasmid pKP048, which contains an integration structure of a Tn3-based transposon and partial Tn4401 segment. Inserted fragments (truncated bla(TEM)) were detected upstream of the bla(KPC-2) gene for two E. aerogenes strains. In conclusion, the enterobacterial isolates exhibited sporadic emergence and did not arise by clonal spread at our hospital. The outcome of infections caused by KPC-producing enterobacterial isolates and their mortality were closely associated with the baseline condition of patients. The spread of bla(KPC-2) gene between different enterobacterial species in China was mainly mediated by horizontal transfer of the Tn3-based transposons and not the bla(KPC-2)-carrying plasmids.

  14. Colicin type 7 produced by majority of Shigella sonnei isolated from Thai patients with diarrhoea.

    PubMed

    Kaewklom, Siriporn; Samosornsuk, Seksun; Pipatsatitpong, Duangnate; Aunpad, Ratchaneewan

    2013-01-01

    Thirty one out of 153 strains of Shigella sonnei isolated from Thai patients with diarrhoea showed antibacterial activity against S. sonnei by agar well diffusion method. All of them harbor plasmids with the genetic determination of colicin type 7 (Js) gene but without colicin E and colicin U gene. The PCR product obtained from strain 35/44 was shown to be the gene for colicin type 7 lytic protein (cja). The partially purified bacteriocin (PPB) containing colicin type 7 of strain 35/44 was prepared and used for characterization. The antibacterial activity of PPB against a total of 17 selected Gram-positive and Gram-negative bacteria was tested. It was found that PPB of strain 35/44 was active against E. coli O157, S. sonnei and S. boydii. The sensitivity of PPB from this strain to proteinase K, trypsin and α-chymotrypsin suggests the proteinaceous nature of these antimicrobial substances. Therefore, this isolated bacterium can be regarded as bacteriocin producing bacteria. The bacteriocin produced by this isolated S. sonnei was heat stable as evidenced by its ability to maintain the activity at 80 °C for 60 min. In addition, it was stable within a wide range of pH (3-9). The molecular weight of colicin type 7 from isolated S. sonnei strain 35/44 analyzed by SDS-PAGE was 54.4 kDa composing of at least five subunits. It is to our knowledge; the first report of Thai patients with diarrhoea that S. sonnei isolated from them contained colicin type 7.

  15. Indentification of vincamine indole alkaloids producing endophytic fungi isolated from Nerium indicum, Apocynaceae.

    PubMed

    Na, Ren; Jiajia, Liu; Dongliang, Yang; Yingzi, Peng; Juan, Hong; Xiong, Liu; Nana, Zhao; Jing, Zhou; Yitian, Luo

    2016-11-01

    Vincamine, a monoterpenoid indole alkaloid which had been marketed as nootropic drugs for the treatment of cerebral insufficiencies, is widely found in plants of the Apocynaceae family. Nerium indicum is a plant belonging to the Apocynaceae family. So, the purpose of this research was designed to investigate the vincamine alkaloids producing endophytic fungi from Nerium indicum, Apocynaceae. 11 strains of endophytic fungi, isolated from the stems and roots of the plant, were grouped into 5 genera on the basis of morphological characteristics. All fungal isolates were fermented and their extracts were preliminary screened by Dragendorff's reagent and thin layer chromatography (TLC). One isolated strain CH1, isolated from the stems of Nerium indicum, had the same Rf value (about 0.56) as authentic vincamine. The extracts of strain CH1 were further analyzed by high performance liquid chromatography (HPLC) and liquid chromatograph-mass spectrometry (LC-MS), and the results showed that the strain CH1 could produce vincamine and vincamine analogues. The acetylcholinesterase (AchE) inhibitory activity assays using Ellman's method revealed that the metabolites of strain CH1 had significant AchE inhibitory activity with an IC50 value of 5.16μg/mL. The isolate CH1 was identified as Geomyces sp. based on morphological and molecular identification, and has been deposited in the China Center for Type Culture Collection (CCTCCM 2014676). This study first reported the natural compounds tabersonine and ethyl-vincamine from endophytic fungi CH1, Geomyces sp. In conclusion, the fungal endophytes from Nerium indicum can be used as alternative source for the production of vincamine and vincamine analogues.

  16. Emergence of KPC-2-producing Escherichia coli isolates in an urban river in Harbin, China.

    PubMed

    Xu, Guofeng; Jiang, Yue; An, Wei; Wang, Hongdong; Zhang, Xiuying

    2015-09-01

    Three KPC-2-producing Escherichia coli (E1, E2, and E3) were recovered from water samples of an urban river in the city of Harbin, China. Antimicrobial susceptibility was determined by broth microdilution. Molecular characterization and genetic relatedness of the isolates were determined by polymerase chain reaction (PCR), pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and PCR-directed phylotyping. Plasmids were analyzed by conjugation, S1-PFGE, Southern blotting and PCR-based replicon typing (PBRT). The genetic environment of the bla KPC-2 gene was determined using PCR and sequencing. PCR analyses revealed that the E1 isolate carried the bla KPC-2, bla CMY-2, bla TEM-1, bla CTX-M-14, and qnrB2 genes and belonged to sequence type ST410, phylogenetic type A; the E2 isolate was assigned to ST131-B2 and carried the bla KPC-2, bla TEM-1, bla CTX-M-3, bla DHA-1, aac(6')-Ib-cr, and qnrS1 genes; while the E3 isolate was of ST648-D and possessed bla KPC-2, bla TEM-1, bla OXA-1, bla CTX-M-15, armA, and aac(6')-Ib-cr genes. PFGE demonstrated that each of the three KPC-2-producing E. coli isolates exhibited an individual XbaI patterns. The bla KPC-2 gene was located on plasmids of 60-140 kb with IncA/C, IncN, or non-typeable replicon types. The genetic environment of bla KPC-2 of the three strains was consistent with the genetic structure of bla KPC-2 on the plasmid pKP048.

  17. Isolation and characterization of lactic acid bacteria strains with ornithine producing capacity from natural sea salt.

    PubMed

    Yu, Jin-Ju; Oh, Suk-Heung

    2010-08-01

    Two lactic acid bacteria (LAB) having ornithine-producing capacity were isolated from Korean natural sea salt. They were Gram-positive, short rod-type bacteria, and able to grow anaerobically with CO(2) production. The isolates grew well on MRS broth at 30-37 degrees C and a pH of 6.5-8.0. The optimum temperature and pH for growth are 37 degrees C and pH 7.0. The isolates fermented D-ribose, D-galactose, D-lactose, D-maltose, Dcellobiose, D-tagatose, D-trehalose, sucrose, D-melezitose, gentiobiose, D-glucose but not D-melibiose, inositol, and L-sorbose. The 16S rDNA sequences of the two isolates showed 99.5% and 99.6% homology with the Weissella koreensis S5623 16S rDNA (Access no. AY035891). They were accordingly identified and named as Weissella koreensis MS1-3 and Weissella koreensis MS1-14, and produced intracellular ornithine at levels of 72 mg/100 g cell F.W. and 105 mg/100 g cell F.W. and extracellular ornithine at levels of 4.5 mg/100 ml and 4.6 mg/100 ml medium, respectively, by culturing in MRS broth supplemented with 1% arginine. High cell growth was maintained in MRS broth with a NaCl concentration of 0-6%. These results show for the first time that Korean natural sea salts contain lactic acid bacteria Weissella koreensis strains having ornithine producing capacity.

  18. Histamine, cadaverine, and putrescine produced in vitro by enterobacteriaceae and pseudomonadaceae isolated from spinach.

    PubMed

    Lavizzari, T; Breccia, M; Bover-Cid, S; Vidal-Carou, M C; Veciana-Nogués, M T

    2010-02-01

    A total of 364 bacterial isolates, obtained from spinach leaves, were assayed in a decarboxylase broth containing histidine, lysine, and ornithine to check their ability to produce biogenic amines, and then quantified by high-performance liquid chromatography. Among these isolates, 240 formed cadaverine, 208 formed putrescine, and 196 formed histamine, in widely varying amounts. They frequently produced more than one biogenic amine. Klebsiella pneumoniae subsp. pneumoniae and Morganella morganii were the main histamine producers, with mean values of 1,600 and 2,440 mg/liter, respectively, followed by Pantoea spp. 3 (1,710 mg/liter) and Hafnia alvei (2,500 mg/liter). Enterobacter amnigenus and Enterobacter cloacae produced particularly high amounts of putrescine, with mean values of 2,340 and 2,890 mg/liter, respectively. The strongest cadaverine formation was shown by Serratia liquefaciens (3,300 mg/liter), Serratia marcescens (3,280 mg/liter), and Stenotrophomonas maltophilia (1,000 mg/liter).

  19. Biosurfactant-producing bacterium, Pseudomonas aeruginosa MA01 isolated from spoiled apples: physicochemical and structural characteristics of isolated biosurfactant.

    PubMed

    Abbasi, Habib; Hamedi, Mir Manochehr; Lotfabad, Tayebe Bagheri; Zahiri, Hossein Shahbani; Sharafi, Hakimeh; Masoomi, Fatemeh; Moosavi-Movahedi, Ali Akbar; Ortiz, Antonio; Amanlou, Massoud; Noghabi, Kambiz Akbari

    2012-02-01

    An extensive investigation was conducted to isolate indigenous bacterial strains with outstanding performance for biosurfactant production from different types of spoiled fruits, food-related products and food processing industries. An isolate was selected from 800 by the highest biosurfactant yield in soybean oil medium and it was identified by 16S rRNA and the two most relevant hypervariable regions of this gene; V3 and V6 as Pseudomonas aeruginosa MA01. The isolate was able to produce 12 g/l of a glycolipid-type biosurfactant and generally less efficient to emulsify vegetable oils compared to hydrocarbons and could emulsify corn and coconut oils more than 50%. However, emulsification index (E(24)) of different hydrocarbons including hexane, toluene, xylene, brake oil, kerosene and hexadecane was between 55.8% and 100%. The surface tension of pure water decreased gradually with increasing biosurfactant concentration to 32.5 mNm(-1) with critical micelle concentration (CMC) value of 10.1mg/l. Among all carbon substrates examined, vegetable oils were the most effective on biosurfactant production. Two glycolipid fractions were purified from the biosurfactant crude extracts, and FTIR and ES-MS were used to determine the structure of these compounds. The analysis indicated the presence of three major monorhamnolipid species: R(1)C(10)C(10), R(1)C(10)C(12:1), and R(1)C(10)C(12); as well as another three major dirhamnolipid species: R(2)C(10)C(10), R(2)C(10)C(12:1), and R(2)C(10)C(12). The strain sweep experiment for measuring the linear viscoelastic of biosurfactant showed that typical behavior characteristics of a weak viscoelastic gel, with storage modulus greater than loss modulus at all frequencies examined, both showing some frequency dependence.

  20. Dual toxin-producing strain of Clostridium botulinum type Bf isolated from a California patient with infant botulism.

    PubMed

    Barash, Jason R; Arnon, Stephen S

    2004-04-01

    A retrospective study of Clostridium botulinum strains isolated from patients from California with infant botulism identified the fourth known C. botulinum strain that produces both type B and type F botulinum toxins. This unique strain represented 0.12% of the California infant botulism case isolates from 1976 to 2003. The relative concentrations of type B and F toxins produced were temperature dependent.

  1. Molecular characterization and phylogeny of Shiga toxin-producing Escherichia coli isolates obtained from two Dutch regions using whole genome sequencing.

    PubMed

    Ferdous, M; Friedrich, A W; Grundmann, H; de Boer, R F; Croughs, P D; Islam, M A; Kluytmans-van den Bergh, M F Q; Kooistra-Smid, A M D; Rossen, J W A

    2016-07-01

    Shiga toxin-producing Escherichia coli (STEC) is one of the major causes of human gastrointestinal disease and has been implicated in sporadic cases and outbreaks of diarrhoea, haemorrhagic colitis and haemolytic uremic syndrome worldwide. In this study, we determined the molecular characteristics and phylogenetic relationship of STEC isolates, and their genetic diversity was compared to that of other E. coli populations. Whole genome sequencing was performed on 132 clinical STEC isolates obtained from the faeces of 129 Dutch patients with gastrointestinal complaints. STEC isolates of this study belonged to 44 different sequence types (STs), 42 serogenotypes and 14 stx subtype combinations. Antibiotic resistance genes were more frequently present in stx1-positive isolates compared to stx2 and stx1 + stx2-positive isolates. The iha, mchB, mchC, mchF, subA, ireA, senB, saa and sigA genes were significantly more frequently present in eae-negative than in eae-positive STEC isolates. Presence of virulence genes encoding type III secretion proteins and adhesins was associated with isolates obtained from patients with bloody diarrhoea. Core genome phylogenetic analysis showed that isolates clustered according to their ST or serogenotypes irrespective of stx subtypes. Isolates obtained from patients with bloody diarrhoea were from diverse phylogenetic backgrounds. Some STEC isolates shared common ancestors with non-STEC isolates. Whole genome sequencing is a powerful tool for clinical microbiology, allowing high-resolution molecular typing, population structure analysis and detailed molecular characterization of strains. STEC isolates of a substantial genetic diversity and of distinct phylogenetic groups were observed in this study.

  2. Distribution and expression of the Ade multidrug efflux systems in Acinetobacter baumannii clinical isolates.

    PubMed

    Pagdepanichkit, Sirawit; Tribuddharat, Chanwit; Chuanchuen, Rungtip

    2016-09-01

    One hundred Acinetobacter baumannii clinical isolates were examined for inhibitory effect of reserpine and carbonyl cyanide m-chlorophenylhydrazone (CCCP) on the antimicrobial susceptibility and expression of 4 resistant-nodulation-cell division (RND)-type multidrug efflux systems, including AdeABC, AdeDE, AdeIJK, and AdeFGH, using RT-PCR. Ten A. baumannii isolates expressing AdeABC, AdeIJK, or AdeFGH were randomly selected for determination of transcription level and regulatory mutations. While all the isolates were resistant to multiple drugs, the reserpine and CCCP experiment showed that the multidrug resistance phenotype in most A. baumannii isolates was associated with efflux pumps. Most isolates expressed at least one of the RND-type efflux pumps tested (97%). AdeIJK expression was most common (97%), but none of the isolates produced AdeDE. Fifty-two percent of the A. baumannii isolates simultaneously produced up to 3 RND-type efflux systems (i.e., AdeABC, AdeFGH, and AdeIJK). No good correlation between the expression of RND-type efflux pumps and the type of antimicrobial resistance was observed. Overexpression of AdeABC, AdeIJK, and AdeFGH was not always related to the presence of mutations in their corresponding regulatory genes. This study highlights (i) the universal presence of the RND-type efflux pumps with variable levels of expression level among the A. baumannii in this collection and (ii) the complexity of their regulation of expression.

  3. Isolation and screening of strains producing high amounts of rutin degrading enzymes from Fagopyrum tataricum seeds.

    PubMed

    Zheng, Ya-Di; Luo, Qing-Lin; Zhou, Mei-Liang; Wang, De-Zhou; Zhang, Ye-Dong; Shao, Ji-Rong; Zhu, Xue-Mei; Tang, Yu

    2013-02-01

    The rutin degrading enzyme (RDE) was isolated and purified from tartary buckwheat seeds. The RDE was purified about 11.34-fold and its final yield was 3.5%, which was very low, due to our purification strategy of giving priority to purity over yield. The RDE molecular weight was estimated to be about 60 kDa. When rutin was used as substrate, an optimal enzyme activity was seen at around pH 5.0 and 40 °C. Strains isolation strategy characterized by the use of rutin as sole carbon source in enrichment cultures was used to isolate RDE-producing strains. Then the active strains were identified by morphology characterization and 18s rDNA-ITS (Internal Transcribed Spacer) gene sequencing. Three isolates coded as B3, W2, Y2 were successfully isolated from fusty Fagopyrum tataricum flour cultures. Strain B3 possessed the highest unit activity among these three strains, and its total activity reached up to 171.0 Unit. The active isolate (B3) could be assigned to Penicillium farinosum. When the Penicillium farinosum strains were added to tartary buckwheat flour cultures at pH 5.0, 30 °C after 5 days fermentation, the quercetin production raised up to 1.78 mg/l, almost 5.1 times higher than the fermentation without the above active strains. Hence, a new approach was available to utilize microorganism-aided fermentation for effective quercetin extraction from Fagopyrum tataricum seeds.

  4. Phenotypic Tests for the Detection of β-Lactamase-Producing Enterobacteriaceae Isolated from Different Environments.

    PubMed

    de Oliveira, Daniele V; Van Der Sand, Sueli T

    2016-07-01

    Some bacteria from the Enterobacteriaceae family are showing a significant capability to disseminate β-lactams resistance mechanisms among them, and these same mechanisms can be carried out from the hospital environment to superficial water. The aim of this study was to evaluate different phenotypic methods for the detection β-lactamases production by enterobacteria isolated from the anthropogenic environment: hospital wastewater and from a stream that cross the city of Porto Alegre. The applied tests were the modified Hodge test (MHT) and phenotypic tests with the following inhibitors: carbapenemase-phenylboronic acid (APB), metallo-β-lactamase-EDTA, AmpC β-lactamase-cloxacillin, and the confirmatory test for extended-spectrum β-lactamase (ESBL)-clavulanic acid. For this evaluation, 131 isolates were initially subjected to antibiogram using the following antimicrobials: cefotaxime (30 µg), cefpodoxime (10 μg), ceftazidime (30 µg), ertapenem (10 μg), meropenem (10 μg), and aztreonam (30 μg). After this first screening, 62 isolates showed a profile resistance for at least one antimicrobial. These isolates were subjected to all phenotypic tests. Of those, 40 isolates were positive for at least one phenotypic test. In MHT test, one isolate was positive and five were with inconclusive results. The results achieved with the inhibitors are as follows: APB 25/40 positive strains; EDTA 8/40 positive strains; and with CLOXA 2/40 positive strains. ESBL production was observed for 34/40 strains. This assessment shows a high level of bacteria which can produce enzymes that inactivate β-lactams present in the different environment like the stream waters and from the hospital settings.

  5. Isolation and Characterization of Chitosan-Producing Bacteria from Beaches of Chennai, India

    PubMed Central

    Kaur, Kuldeep; Dattajirao, Vikrant; Shrivastava, Vikas; Bhardwaj, Uma

    2012-01-01

    Chitosan is a deacetylated product of chitin produced by chitin deacetylase, an enzyme that hydrolyses acetamido groups of N-acetylglucosamine in chitin. Chitosan is a natural polymer that has great potential in biotechnology and in the biomedical and pharmaceutical industries. Commercially, it is produced from chitin via a harsh thermochemical process that shares most of the disadvantages of a multistep chemical procedure. It is environmentally unsafe and not easily controlled, leading to a broad and heterogeneous range of products. An alternative or complementary procedure exploiting the enzymatic deacetylation of chitin could potentially be employed, especially when a controlled and well-defined process is required. In this study, 20 strains of bacteria were isolated from soil samples collected from different beaches of Chennai, India. Of these 20 bacterial strains, only 2 strains (S3, S14) are potent degrader of chitin and they are also a good producer of the enzyme chitin deacetylase so as to release chitosan. PMID:22919468

  6. High prevalence of extensively drug-resistant and metallo beta-lactamase-producing clinical Acinetobacter baumannii in Iran.

    PubMed

    Maspi, Hossein; Mahmoodzadeh Hosseini, Hamideh; Amin, Mohsen; Imani Fooladi, Abbas Ali

    2016-09-01

    Acinetobacter species particularly Acinetobacter baumannii (A. baumannii) have been widely reported as broad-spectrum antibiotic resistant pathogens. Expression of various types of metallo beta-lactamases (MBL), classified as Ambler class B, has been associated with carbapenem resistance. Here, we attempted to assess the frequency of extensively drug-resistant (XDR) and MBL-producing A. baumannii among clinical isolates. 86 clinical A. baumannii strains were collected from 2014 to 2015 and their susceptibility to meropenem (10 μg), imipenem (10 μg), azteronem (30 μg), pipracillin (100 μg) tazobactam (110 μg), tobramycin (10 μg), fosfomycin (200 μg), rifampicin (5 μg), colistin (10 μg), tigecycline (15 μg), sulbactam/ampicillin (10 μg + 10 μg) and polymixin B (300 U) was evaluated using disk diffusion method. The MBL-producing isolates were screened using combined disc diffusion method. Furthermore, the presence of blaVIM, blaIMP, blaSPM, blaGIM, blaSIM and blaNDM was detected by PCR. 34.9% of isolates were recovered from bronchoalveolar lavage (BAL). 81 (94.2%) and 62 (71.2%) isolates were multidrug resistance (MDR) and XDR, respectively. 44 (51.2%) and 65 (75.6%) isolates were MBL-producing strains with resistance to imipenem and meropenem, respectively. 2 (2.3%), 13 (15.1%), 2 (2.3%), 4 (4.7%) and 2 (2.3%) isolates carried blaVIM, blaIMP, blaSPM, blaGIM and blaSIM genes, respectively. Our data showed that the rate of XDR and MBL A. baumannii is on the rise.

  7. Molecular characterization of Acanthamoeba isolated in water treatment plants and comparison with clinical isolates.

    PubMed

    Magnet, A; Galván, A L; Fenoy, S; Izquierdo, F; Rueda, C; Fernandez Vadillo, C; Pérez-Irezábal, J; Bandyopadhyay, K; Visvesvara, G S; da Silva, A J; del Aguila, C

    2012-07-01

    A total of 116 samples (44 clinical specimens and 72 environmental samples) have been analyzed for the presence of Acanthamoeba. The environmental samples (ESs) were collected from four drinking water treatment plants (DWTP, n=32), seven wastewater treatment plants (n=28), and six locations of influence (n=12) on four river basins from the central area of Spain (winter-spring 2008). Water samples were concentrated by using the IDEXX Filta-Max(®) system. Acanthamoeba was identified in 65 of the 72 ESs by culture isolation (90.3%) and 63 by real-time PCR (87.5%), resulting in all sampling points (100%) positive for Acanthamoeba when considering both techniques and all the time period analyzed. Nine of the 44 clinical specimens were positive for Acanthamoeba. Seventeen Acanthamoeba strains (eight from four DWTP and nine from clinical samples) were also established in axenic-PYG medium. Twenty-four of the ESs and the 17 Acanthamoeba sp. strains were genotyped as T4/1, T4/8, and T4/9. The eight strains isolated from the DWTP samples were inoculated in nude mouse to ascertain their potential pathogenicity in this model. Animals that were inoculated died or showed central nervous system symptoms 9 days post-inoculation. Examination of immunofluorescence-stained brain and lung tissue sections showed multiple organisms invading both tissues, and re-isolation of throphozoites was successful in these tissues of all infected animals. For the first time, potentially pathogenic Acanthamoeba T4 has been detected in 100% of different types of water samples including tap water and sewage effluents in the central area of Spain suggesting a potential health threat for humans especially for the contact lens wearers.

  8. Analysis of plasmid-mediated multidrug resistance in Escherichia coli and Klebsiella oxytoca isolates from clinical specimens in Japan.

    PubMed

    Ode, Takashi; Saito, Ryoichi; Kumita, Wakako; Sato, Kenya; Okugawa, Shu; Moriya, Kyoji; Koike, Kazuhiko; Okamura, Noboru

    2009-10-01

    This study investigated the relationship of plasmid-mediated quinolone resistance (PMQR) and aminoglycoside resistance among oxyimino-cephalosporin-resistant Escherichia coli (n=46) and Klebsiella oxytoca (n=28) clinical isolates in Japan. Seventy-three isolates appeared to produce an extended-spectrum beta-lactamase (ESBL) and one K. oxytoca isolate produced IMP-1 metallo-beta-lactamase (MBL). Polymerase chain reaction (PCR) and sequencing confirmed that eight CTX-M-9/SHV-12-producing isolates, one IMP-1-producing K. oxytoca isolate, and six ESBL-positive E. coli isolates respectively possessed PMQR genes qnrA1, qnrB6, and aac(6')-Ib-cr. All qnr-positive isolates also carried either aac(6')-Ib or aac(6')-IIc aminoglycoside acetyltransferase genes. Resistance determinants to beta-lactams, quinolones and aminoglycosides were co-transferred with a plasmid of ca. 140 kb. The qnrA1 gene was located downstream of insertion sequence ISCR1 in complex class 1 integrons. A novel qnrA1-carrying class 1 integron with the cassette arrangement aac(6')-IIc-aadA2 as well as a unique class 1 integron with bla(IMP-1)-aac(6')-IIc cassettes on the plasmid carrying qnrB6 were found in K. oxytoca isolates. We describe the identification of qnrB6 and aac(6')-Ib-cr and the close association of qnr with aac(6')-Ib and aac(6')-IIc for the first time in clinical isolates producing ESBL or MBL in Japan.

  9. Isolation of butyrate-utilizing bacteria from thermophilic and mesophilic methane-producing ecosystems

    SciTech Connect

    Henson, J.M.

    1983-01-01

    The ability of various ecosystems to convert butyrate to methane was studied in order to isolate the bacteria responsible for the conversion. When thermophilic digester sludge was enriched with butyrate, methane was produced without a lag period. Marine sediments enriched with butyrate required a 2-week incubation period before methanogenesis began. A thermophilic digester was studied in more detail and found by most-probable-number enumeration to have ca. 5 x 10/sup 6/ butyrate-utilizing bactera/ml of sludge. A thermophilic butyrate-utilizing bacterium was isolated in coculture with Methanobacterium thermoautotrophicum and a Methanosarcina sp. This bacterium was a gram-negative, slightly curved rod that occurred singly, was nonmotile, and did not appear to produce spores. The thermophilic digester was infused with butyrate at the rate of 10 ..mu..moles/ml of sludge per day. Biogas production increased by 150%, with the percentage of methane increasing from 58% to 68%. Acetate, propionate, and butyrate did not accumulate. Butyrate-utilizing enrichments from mesophilic ecosystems were used in obtaining cocultures of butyrate-utilizing bacteria. These cocultures served as inocula for attempts to isolate pure cultures of butyrate-utilizing bacteria by use of hydrogenase-containing membrane fragments of Escherichia coli. After a 3-week incubation period, colonies appeared only in inoculated tubes that contained membrane fragments and butyrate.

  10. Isolation and purification of propionicin PLG-1, a bacteriocin produced by a strain of Propionibacterium thoenii.

    PubMed Central

    Lyon, W J; Glatz, B A

    1993-01-01

    Production of propionicin PLG-1 by Propionibacterium thoenii P127 was pH dependent, with maximal activity detected in supernatants of cultures grown at pH 7.0 Propionicin PLG-1 was purified by ion-exchange chromatography and isoelectric focusing. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of propionicin PLG-1 purified through isoelectric focusing resolved a protein band with a molecular weight of 10,000. Propionicin PLG-1 was bactericidal to sensitive cells, demonstrating single-hit kinetics. The producing strain harbored a single plasmid (pLG1) with an approximate size of 250 kb. Preliminary data indicate that both propionicin PLG-1 and immunity to the bacteriocin are encoded on the chromosome. Exposure of strain P127 to acriflavine or to N-methyl-N'-nitro-N-nitrosoguanidine yielded isolates that no longer produced bacteriocin activity and isolates that were cured of the plasmid. However, loss of bacteriocin production was not correlated with loss of the plasmid. Isolates cured of the plasmid were phenotypically identical to plasmid-bearing cells in fermentation patterns, pigment production, and growth characteristics. Images PMID:8439170

  11. Glutaminase-producing Meyerozyma (Pichia) guilliermondii isolated from Thai soy sauce fermentation.

    PubMed

    Aryuman, Phichayaphorn; Lertsiri, Sittiwat; Visessanguan, Wonnop; Niamsiri, Nuttawee; Bhumiratana, Amaret; Assavanig, Apinya

    2015-01-02

    In this study, 34 yeast isolates were obtained from koji and moromi samples of Thai soy sauce fermentation. However, the most interesting yeast strain was isolated from the enriched 2 month-old (M2) moromi sample and identified as Meyerozyma (Pichia) guilliermondii EM2Y61. This strain is a salt-tolerant yeast that could tolerate up to 20% (w/v) NaCl and produce extracellular and cell-bound glutaminases. Interestingly, its glutaminases were more active in 18% (w/v) NaCl which is a salt concentration in moromi. The extracellular glutaminase's activity was found to be much higher than that of cell-bound glutaminase. The highest specific activity and stability of the extracellular glutaminase were found in 18% (w/v) NaCl at pH4.5 and 37°C. A challenge test by adding partially-purified extracellular glutaminase from M. guilliermondii EM2Y61 into 1 month-old (M1) moromi sample showed an increased conversion of L-glutamine to L-glutamic acid. This is the first report of glutaminase producing M. guilliermondii isolated from the moromi of Thai soy sauce fermentation. The results suggested the potential application of M. guilliermondii EM2Y61 as starter yeast culture to increase l-glutamic acid during soy sauce fermentation.

  12. Antimicrobial Activity of Monoramnholipids Produced by Bacterial Strains Isolated from the Ross Sea (Antarctica) †

    PubMed Central

    Tedesco, Pietro; Maida, Isabel; Palma Esposito, Fortunato; Tortorella, Emiliana; Subko, Karolina; Ezeofor, Chidinma Christiana; Zhang, Ying; Tabudravu, Jioji; Jaspars, Marcel; Fani, Renato; de Pascale, Donatella

    2016-01-01

    Microorganisms living in extreme environments represent a huge reservoir of novel antimicrobial compounds and possibly of novel chemical families. Antarctica is one of the most extraordinary places on Earth and exhibits many distinctive features. Antarctic microorganisms are well known producers of valuable secondary metabolites. Specifically, several Antarctic strains have been reported to inhibit opportunistic human pathogens strains belonging to Burkholderia cepacia complex (Bcc). Herein, we applied a biodiscovery pipeline for the identification of anti-Bcc compounds. Antarctic sub-sea sediments were collected from the Ross Sea, and used to isolate 25 microorganisms, which were phylogenetically affiliated to three bacterial genera (Psychrobacter, Arthrobacter, and Pseudomonas) via sequencing and analysis of 16S rRNA genes. They were then subjected to a primary cell-based screening to determine their bioactivity against Bcc strains. Positive isolates were used to produce crude extracts from microbial spent culture media, to perform the secondary screening. Strain Pseudomonas BNT1 was then selected for bioassay-guided purification employing SPE and HPLC. Finally, LC-MS and NMR structurally resolved the purified bioactive compounds. With this strategy, we achieved the isolation of three rhamnolipids, two of which were new, endowed with high (MIC < 1 μg/mL) and unreported antimicrobial activity against Bcc strains. PMID:27128927

  13. Isolation and Identification of an Enterobacter cloacae Strain Producing a Novel Subtype of Shiga Toxin Type 1

    PubMed Central

    McQuaid, Cassandra; Schrader, Kimmi

    2014-01-01

    We describe here the isolation and identification of a Shiga toxin 1 (Stx1)-producing Enterobacter cloacae strain, M12X01451, from a human clinical specimen. The bacterial isolate was identified as E. cloacae using a polyphasic approach that included phenotypic, genetic, and proteomic analyses. The M12X01451 stx1 was sequenced, and the holotoxin was found to share only 87% amino acid sequence identity with the nearest Stx1 subtype reference sequence. Sequence analysis of the regions immediately flanking stx1 displayed similarities with bacteriophage-related sequences, suggesting a prophage origin. The stx1 gene was a stable element within the M12X01451 genome, as demonstrated by real-time PCR detection following successive subculturing of the bacterial isolate. Culture supernatant from M12X01451 was cytotoxic to Vero cells but was not neutralized by an anti-Stx1 monoclonal antibody. In addition, Stx1 from M12X01451 demonstrated limited antigenicity with two commercially available lateral flow immunoassays. The M12X01451 Stx represents a new Stx1 subtype based on the degree of sequence dissimilarity with Stx1 subtype reference sequences and its limited reactivity with anti-Stx1 antibodies. PMID:24759708

  14. Isolation and functional characterization of a biosurfactant produced by Lactobacillus paracasei.

    PubMed

    Gudiña, Eduardo J; Teixeira, José A; Rodrigues, Lígia R

    2010-03-01

    In this study, the crude biosurfactant produced by a Lactobacillus paracasei strain isolated in a Portuguese dairy industry was characterized. The minimum surface tension (41.8mN/m) and the critical micelle concentration (2.5mg/ml) obtained were found to be similar to the values previously reported for biosurfactants isolated from other lactobacilli. The biosurfactant was found to be stable to pH changes over a range from 6 to 10, being more effective at pH 7, and showed no loss of surface activity after incubation at 60 degrees C for 120h. Although the biosurfactant chemical composition has not been determined yet, a fraction was isolated through acidic precipitation, which exhibited higher surface activity as compared with the crude biosurfactant. Furthermore, this isolated biosurfactant showed antimicrobial and anti-adhesive activities against several pathogenic microorganisms. In addition, L. paracasei exhibited a strong autoaggregating phenotype, which was maintained after washing and resuspending the cells in PBS, meaning that this attribute must be related to cell surface components and not to excreted factors. The autoaggregation ability exhibited by this strain, together with the antimicrobial and anti-adhesive properties observed for this biosurfactant opens the possibility for its use as an effective probiotic strain.

  15. Isolation and characterization of bacteriophages specific to hydrogen-sulfide-producing bacteria.

    PubMed

    Gong, Chao; Heringa, Spencer; Singh, Randhir; Kim, Jinkyung; Jiang, Xiuping

    2013-01-01

    The objectives of this study were to isolate and characterize bacteriophages specific to hydrogen-sulfide-producing bacteria (SPB) from raw animal materials, and to develop a SPB-specific bacteriophage cocktail for rendering application. Meat, chicken offal, and feather samples collected from local supermarkets and rendering processing plants were used to isolate SPB (n = 142). Bacteriophages (n = 52) specific to SPB were isolated and purified from the above samples using 18 of those isolated SPB strains as hosts. The host ranges of bacteriophages against 5 selected SPB strains (Escherichia coli, Citrobacter freundii, and Hafnia alvei) were determined. Electron microscopy observation of 9 phages selected for the phage cocktail revealed that 6 phages belonged to the family of Siphoviridae and 3 belonged to the Myoviridae family. Restriction enzyme digestion analysis with endonuclease DraI detected 6 distinguished patterns among the 9 phages. Phage treatment prevented the growth of SPB for up to 10 h with multiplicity of infection ratios of 1, 10, 100, and 1000 in tryptic soy broth at 30 °C, and extended the lag phase of SPB growth for 2 h at 22 °C with multiplicities of infection of 10, 100, and 1000. These results suggest that the selected bacteriophage cocktail has a high potential for phage application to control SPB in raw animal materials destined for the rendering process.

  16. Molecular characterization of Campylobacter lanienae strains isolated from food-producing animals.

    PubMed

    Schweitzer, Nóra; Damjanova, Ivelina; Kaszanyitzky, Eva; Ursu, Krisztina; Samu, Péterné; Tóth, Adám György; Varga, János; Dán, Adám

    2011-05-01

    During 2008 and 2009, within the framework of the Hungarian monitoring program of antibiotic resistance of zoonotic agents from food-producing animals, a significant number (43 strains) of Campylobacter lanienae were detected for the first time in Hungary. The isolates were genotyped using partial 16S rRNA gene sequencing and pulsed-field gel electrophoresis using three different restriction enzymes. The antimicrobial resistance of the isolates was determined by microtiter broth dilution. C. lanienae isolation was successful only from swine but not from other animal species. According to phylogenetic analysis, clustering of the isolates shows the same extensive genetic diversity as other Campylobacter species. Sequence analysis of the partial 16S rRNA gene showed that additional variations exist in variable regions Vc2 and Vc6. SmaI restriction enzyme proved to be the most efficient for pulsed-field gel electrophoresis analysis of C. lanienae. A significant tetracycline resistance (60.9%) and the presence of erythromycin-, enrofloxacin-, and multiresistant C. lanienae strains were found. Although the pathogenic potential of C. lanienae in humans is currently unknown, this study demonstrates that C. lanieanae is common in pigs in the country, provides further details on the genotypic and phenotypic properties of C. lanienae, and offers a genotyping method for use in source tracing.

  17. Clinical Epidemiology and Molecular Analysis of Extended-Spectrum-β-Lactamase-Producing Escherichia coli in Nepal: Characteristics of Sequence Types 131 and 648

    PubMed Central

    Sherchan, Jatan Bahadur; Miyoshi-Akiyama, Tohru; Ohmagari, Norio; Kirikae, Teruo; Nagamatsu, Maki; Tojo, Masayoshi; Ohara, Hiroshi; Sherchand, Jeevan B.; Tandukar, Sarmila

    2015-01-01

    Recently, CTX-M-type extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli strains have emerged worldwide. In particular, E. coli with O antigen type 25 (O25) and sequence type 131 (ST131), which is often associated with the CTX-M-15 ESBL, has been increasingly reported globally; however, epidemiology reports on ESBL-producing E. coli in Asia are limited. Patients with clinical isolates of ESBL-producing E. coli in the Tribhuvan University teaching hospital in Kathmandu, Nepal, were included in this study. Whole-genome sequencing of the isolates was conducted to analyze multilocus sequence types, phylotypes, virulence genotypes, O25b-ST131 clones, and distribution of acquired drug resistance genes. During the study period, 105 patients with ESBL-producing E. coli isolation were identified, and the majority (90%) of these isolates were CTX-M-15 positive. The most dominant ST was ST131 (n = 54; 51.4%), followed by ST648 (n = 15; 14.3%). All ST131 isolates were identified as O25b-ST131 clones, subclone H30-Rx. Three ST groups (ST131, ST648, and non-ST131/648) were compared in further analyses. ST648 isolates had a proportionally higher resistance to non-β-lactam antibiotics and featured drug-resistant genes more frequently than ST131 or non-ST131/648 isolates. ST131 possessed the most virulence genes, followed by ST648. The clinical characteristics were similar among groups. More than 38% of ESBL-producing E. coli isolates were from the outpatient clinic, and pregnant patients comprised 24% of ESBL-producing E. coli cases. We revealed that the high resistance of ESBL-producing E. coli to multiple classes of antibiotics in Nepal is driven mainly by CTX-M-producing ST131 and ST648. Their immense prevalence in the communities is a matter of great concern. PMID:25824221

  18. Molecular analyses of TEM genes and their corresponding penicillinase-producing Neisseria gonorrhoeae isolates in Bangkok, Thailand.

    PubMed

    Nakayama, Shu-Ichi; Tribuddharat, Chanwit; Prombhul, Sasiprapa; Shimuta, Ken; Srifuengfung, Somporn; Unemo, Magnus; Ohnishi, Makoto

    2012-02-01

    Neisseria gonorrhoeae is a major public health problem globally, especially because the bacterium has developed resistance to most antimicrobials introduced for first-line treatment of gonorrhea. In the present study, 96 N. gonorrhoeae isolates with high-level resistance to penicillin from 121 clinical isolates in Thailand were examined to investigate changes related to their plasmid-mediated penicillin resistance and their molecular epidemiological relationships. A β-lactamase (TEM) gene variant, bla(TEM-135), that may be a precursor in the transitional stage of a traditional bla(TEM-1) gene into an extended-spectrum β-lactamase (ESBL), possibly causing high resistance to all extended-spectrum cephalosporins in N. gonorrhoeae, was identified. Clonal analysis using multilocus sequence typing (MLST) and N. gonorrhoeae multiantigen sequence typing (NG-MAST) revealed the existence of a sexual network among patients from Japan and Thailand. Molecular analysis of the bla(TEM-135) gene showed that the emergence of this allele might not be a rare genetic event and that the allele has evolved in different plasmid backgrounds, which results possibly indicate that it is selected due to antimicrobial pressure. The presence of the bla(TEM-135) allele in the penicillinase-producing N. gonorrhoeae population may call for monitoring for the possible emergence of ESBL-producing N. gonorrhoeae in the future. This study identified a bla(TEM) variant (bla(TEM-135)) that is a possible intermediate precursor for an ESBL, which warrants international awareness.

  19. Genome sequences of Ralstonia insidiosa type strain ATCC 49129 and strain FC1138, a strong biofilm producer isolated from a fresh-cut produce-processing plant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ralstonia insidiosa FC1138 is a strong biofilm producer, isolated from a local fresh-cut produce processing plant. Here, we present the complete genome sequence of Ralstonia insidiosa FC1138 which includes two circular chromosomes and a plasmid. To our knowledge, this is the first reported complete ...

  20. Isolation and structure of whiskey polyphenols produced by oxidation of oak wood ellagitannins.

    PubMed

    Fujieda, Miho; Tanaka, Takashi; Suwa, Yoshihide; Koshimizu, Seiichi; Kouno, Isao

    2008-08-27

    Three new phenolic compounds named whiskey tannins A and B and carboxyl ellagic acid were isolated from commercial Japanese whiskey, along with gallic acid, ellagic acid, brevifolin carboxylic acid, three galloyl glucoses, a galloyl ester of phenolic glucoside, 2,3-(S)-hexahydroxydiphenoylglucose, and castacrenin B. Whiskey tannins A and B were oxidation products of a major oak wood ellagitannin, castalagin, in which the pyrogallol ring at the glucose C-1 position of castalagin was oxidized to a cyclopentenone moiety. These tannins originated from ellagitannins contained in the oak wood used for barrel production; however, the original oak wood ellagitannins were not detected in the whiskey. To examine whether the whiskey tannins were produced during the charring process of barrel production, pyrolysis products of castalagin were investigated. Dehydrocastalagin and a new phenolcarboxylic acid trislactone having an isocoumarin structure were isolated, along with castacrenin F and ellagic acid. However, whiskey tannins were not detected in the products.

  1. Characteristics of extracellular proteases produced by Bacillus laterosporus and Flavobacterium sp. isolated from gelatinfactory effluents.

    PubMed

    Sharma, A; Rao, C L; Ball, B K; Hasija, S K

    1996-11-01

    Forty bacterial isolates from the effluents of a gelatin factory (Jabalpur, India) were screened for protease activity and the two most potent producers were identified as Bacillus laterosporus and a Flavobacterium sp. The enzymes of both isolates were optimal at pH 8 and 60°C, with maximum activity after 90 min. The enzyme activity of B. laterosporus was suppressed by Fe(2+), Mg(2+), Mn(2+) and Zn(2+) ions but was enhanced by Ba(2+) and Ca(2+). That of Flavobacterium sp. was suppressed by Mg(2+) and Mn(2+) ions but enhanced by Ba(2+), Ca(2+) and Fe(2+). The enzyme activity of the former was strongly inhibited by KCN, whereas that of the latter was only slightly inhibited by 8-hydroxyquinoline.

  2. Multidrug resistance and ESBL-producing Salmonella spp. isolated from broiler processing plants.

    PubMed

    Ziech, Rosangela Estel; Lampugnani, Camila; Perin, Ana Paula; Sereno, Mallu Jagnow; Sfaciotte, Ricardo Antônio Pilegi; Viana, Cibeli; Soares, Vanessa Mendonça; Pinto, José Paes de Almeida Nogueira; Bersot, Luciano dos Santos

    2016-01-01

    The aim of this study was to investigate the occurrence of multidrug-resistant, extended spectrum beta-lactamase (ESBL) producing Salmonella spp. isolated from conveyor belts of broiler cutting rooms in Brazilian broiler processing plants. Ninety-eight strains of Salmonella spp. were analyzed. Multidrug resistance was determined by the disk diffusion test and the susceptibility of the isolated bacteria was evaluated against 18 antimicrobials from seven different classes. The double disk diffusion test was used to evaluate ESBL production. Of the 98 strains tested, 84 were multidrug resistant. The highest rates of resistance were against nalidixic acid (95%), tetracycline (91%), and the beta-lactams: ampicillin and cefachlor (45%), followed by streptomycin and gentamicin with 19% and 15% of strain resistance, respectively. By contrast, 97% of the strains were sensitive to chloramphenicol. 45% of the strains were positive for the presence of ESBL activity. In this study, high rates of multidrug resistance and ESBL production were observed in Salmonella spp.

  3. Clinical resistance and decreased susceptibility in Streptococcus suis isolates from clinically healthy fattening pigs.

    PubMed

    Callens, Bénédicte F; Haesebrouck, Freddy; Maes, Dominiek; Butaye, Patrick; Dewulf, Jeroen; Boyen, Filip

    2013-04-01

    Streptococcus suis (S. suis) has often been reported as an important swine pathogen and is considered as a new emerging zoonotic agent. Consequently, it is important to be informed on its susceptibility to antimicrobial agents. In the current study, the Minimum Inhibitory Concentration (MIC) population distribution of nine antimicrobial agents has been determined for nasal S. suis strains, isolated from healthy pigs at the end of the fattening period from 50 closed or semiclosed pig herds. The aim of the study was to report resistance based on both clinical breakpoints (clinical resistance percentage) and epidemiological cutoff values (non-wild-type percentage). Non-wild-type percentages were high for tetracycline (98%), lincomycin (92%), tilmicosin (72%), erythromycin (70%), tylosin (66%), and low for florfenicol (0%) and enrofloxacin (0.3%). Clinical resistance percentages were high for tetracycline (95%), erythromycin (66%), tylosin (66%), and low for florfenicol (0.3%) and enrofloxacin (0.3%). For tiamulin, for which no clinical breakpoint is available, 57% of the isolates did not belong to the wild-type population. Clinical resistance and non-wild-type percentages differed substantially for penicillin. Only 1% of the tested S. suis strains was considered as clinically resistant, whereas 47% of the strains showed acquired resistance when epidemiological cutoff values were used. In conclusion, MIC values for penicillin are gradually increasing, compared to previous reports, although pigs infected with strains showing higher MICs may still respond to treatment with penicillin. The high rate of acquired resistance against tiamulin has not been reported before. Results from this study clearly demonstrate that the use of different interpretive criteria contributes to the extent of differences in reported antimicrobial resistance results. The early detection of small changes in the MIC population distribution of isolates, while clinical failure may not yet be

  4. Molecular Characterization of Fluoroquinolone Resistance in Nontypeable Haemophilus influenzae Clinical Isolates

    PubMed Central

    Puig, Carmen; Tirado-Vélez, José Manuel; Calatayud, Laura; Tubau, Fe; Garmendia, Junkal; Ardanuy, Carmen; Marti, Sara

    2014-01-01

    Nontypeable Haemophilus influenzae (NTHi) is a common cause of respiratory infections in adults, who are frequently treated with fluoroquinolones. The aims of this study were to characterize the genotypes of fluoroquinolone-resistant NTHi isolates and their mechanisms of resistance. Among 7,267 H. influenzae isolates collected from adult patients from 2000 to 2013, 28 (0.39%) were ciprofloxacin resistant according to Clinical and Laboratory Standards Institute (CLSI) criteria. In addition, a nalidixic acid screening during 2010 to 2013 detected five (0.23%) isolates that were ciprofloxacin susceptible but nalidixic acid resistant. Sequencing of their quinolone resistance-determining regions and genotyping by pulse-field gel electrophoresis and multilocus sequence typing of the 25 ciprofloxacin-resistant isolates available and all 5 nalidixic acid-resistant isolates were performed. In the NTHi isolates studied, two mutations producing changes in two GyrA residues (Ser84, Asp88) and/or two ParC residues (Ser84, Glu88) were associated with increased fluoroquinolone MICs. Strains with one or two mutations (n = 15) had ciprofloxacin and levofloxacin MICs of 0.12 to 2 μg/ml, while those with three or more mutations (n = 15) had MICs of 4 to 16 μg/ml. Long persistence of fluoroquinolone-resistant strains was observed in three chronic obstructive pulmonary disease patients. High genetic diversity was observed among fluoroquinolone-resistant NTHi isolates. Although fluoroquinolones are commonly used to treat respiratory infections, the proportion of resistant NTHi isolates remains low. The nalidixic acid disk test is useful for detecting the first changes in GyrA or in GyrA plus ParC among fluoroquinolone-susceptible strains that are at a potential risk for the development of resistance under selective pressure by fluoroquinolone treatment. PMID:25385097

  5. Molecular characterization of fluoroquinolone resistance in nontypeable Haemophilus influenzae clinical isolates.

    PubMed

    Puig, Carmen; Tirado-Vélez, José Manuel; Calatayud, Laura; Tubau, Fe; Garmendia, Junkal; Ardanuy, Carmen; Marti, Sara; de la Campa, Adela G; Liñares, Josefina

    2015-01-01

    Nontypeable Haemophilus influenzae (NTHi) is a common cause of respiratory infections in adults, who are frequently treated with fluoroquinolones. The aims of this study were to characterize the genotypes of fluoroquinolone-resistant NTHi isolates and their mechanisms of resistance. Among 7,267 H. influenzae isolates collected from adult patients from 2000 to 2013, 28 (0.39%) were ciprofloxacin resistant according to Clinical and Laboratory Standards Institute (CLSI) criteria. In addition, a nalidixic acid screening during 2010 to 2013 detected five (0.23%) isolates that were ciprofloxacin susceptible but nalidixic acid resistant. Sequencing of their quinolone resistance-determining regions and genotyping by pulse-field gel electrophoresis and multilocus sequence typing of the 25 ciprofloxacin-resistant isolates available and all 5 nalidixic acid-resistant isolates were performed. In the NTHi isolates studied, two mutations producing changes in two GyrA residues (Ser84, Asp88) and/or two ParC residues (Ser84, Glu88) were associated with increased fluoroquinolone MICs. Strains with one or two mutations (n = 15) had ciprofloxacin and levofloxacin MICs of 0.12 to 2 μg/ml, while those with three or more mutations (n = 15) had MICs of 4 to 16 μg/ml. Long persistence of fluoroquinolone-resistant strains was observed in three chronic obstructive pulmonary disease patients. High genetic diversity was observed among fluoroquinolone-resistant NTHi isolates. Although fluoroquinolones are commonly used to treat respiratory infections, the proportion of resistant NTHi isolates remains low. The nalidixic acid disk test is useful for detecting the first changes in GyrA or in GyrA plus ParC among fluoroquinolone-susceptible strains that are at a potential risk for the development of resistance under selective pressure by fluoroquinolone treatment.

  6. Histamine-producing Lactobacillus parabuchneri strains isolated from grated cheese can form biofilms on stainless steel.

    PubMed

    Diaz, Maria; Del Rio, Beatriz; Sanchez-Llana, Esther; Ladero, Victor; Redruello, Begoña; Fernández, María; Martin, M Cruz; Alvarez, Miguel A

    2016-10-01

    The consumption of food containing large amounts of histamine can lead to histamine poisoning. Cheese is one of the most frequently involved foods. Histamine, one of the biogenic amines (BAs) exhibiting the highest safety risk, accumulates in food contaminated by microorganisms with histidine decarboxylase activity. The origin of these microorganisms may be very diverse with contamination likely occurring during post-ripening processing, but the microorganisms involved during this manufacturing step have never been identified. The present work reports the isolation of 21 histamine-producing Lactobacillus parabuchneri strains from a histamine-containing grated cheese. PCR revealed that every isolate carried the histidine decarboxylase gene (hdcA). Eight lineages were identified based on the results of genome PFGE restriction analysis plus endonuclease restriction profile analysis of the carried plasmids. Members of all lineages were able to form biofilms on polystyrene and stainless steel surfaces. L. parabuchneri is therefore an undesirable species in the dairy industry; the biofilms it can produce on food processing equipment represent a reservoir of histamine-producing bacteria and thus a source of contamination of post-ripening-processed cheeses.

  7. Detection of AmpC β-lactamase producing bacteria isolated in neonatal sepsis

    PubMed Central

    Salamat, Sonia; Ejaz, Hasan; Zafar, Aizza; Javed, Humera

    2016-01-01

    Objective: The objective of this study was to determine the occurrence and antimicrobial profile of AmpC β-lactamase producing bacteria. Methods: The study was conducted at The Children’s Hospital and The Institute of Child Health Lahore, Pakistan, during September 2011 to June 2012. A total number of 1,914 blood samples of suspected neonatal septicemia were processed. Isolates were identified using Gram’s staining, API 20E and API 20NE tests. Gram negative isolates were screened for AmpC β-lactamase production against ceftazidime, cefotaxime and cefoxitin resistance and confirmed by inhibitor based method. Results: Total number of 54 (8.49%) Gram positive and 582 (91.5%) Gram negative bacteria were identified. Among Gram negative isolates 141 (22%) were AmpC producers and found to be 100% resistant to co-amoxiclav, cefoxitin, ceftazidime, cefotaxime, cefuroxime, cefixime, ceftriaxone, cefpodoxime, gentamicin, amikacin and aztreonam. Less resistance was observed against cefepime (30.4%), sulbactam-cefoperazone (24.8%), piperacillin-tazobactam (10.6%), ciprofloxacin (20.5%) and meropenem (2.1%). All the isolates were found sensitive to imipenem. The patients harbored AmpC β-lactamases were on various interventions in which intravenous line was noted among (51.1%), naso-gastric tube (37.6%), ambu bag (8.5%), endotracheal tube (3.5%), ventilator (2.1%) and surgery (0.7%). Conclusion: Extensive use of invasive procedures and third generation cephalosporins should be restricted to avoid the emergence of AmpC beta-lactamases in neonates. PMID:28083055

  8. Antibacterial Activity of Red Pigment Produced by Halolactibacillus alkaliphilus MSRD1--an Isolate from Seaweed.

    PubMed

    Suresh, Murugan; Renugadevi, B; Brammavidhya, S; Iyapparaj, Palanisamy; Anantharaman, Perumal

    2015-05-01

    The present study was carried out with the aim to isolate an antibacterial pigment from seaweed-associated bacterium. The bacterium was identified as Halolactibacillus alkaliphilus MSRD1 by 16S rRNA sequencing. The isolated bacterium was cultured in 50% Luria-Bertani seawater broth (LB-SWB) with 1% glycerol. The pigment was extracted with 99% ethanol and analyzed by UV-Vis spectroscopy at 490 nm. The candidate bacterium was optimized with various NaCl concentrations from 5 to 20%. The results inferred that the bacterium produce maximum pigment at 5% NaCl level. The candidate bacterium H. alkaliphilus MSRD1 was found to be producing the maximum pigment during the 120-h incubation. The protein content of the pigment was found to be maximum of 72% at the end of the 120-h incubation. The extracted pigment was stable up to 80 °C, pink at acidic pH (1 to 5) and orange at basic pH (8 to 12). The isolated pigment was fractionated by silica gel column chromatography. Fractionated pigment was characterized by TLC, FT-IR, and SDS-PAGE. In the antibacterial context, the pigment was highly inhibited Staphylococcus aureus and Salmonella typhi with the zone of inhibition 16 and 14 mm, respectively. According to SDS-PAGE, the size of the pigment was approximately 80 kDa. The H. alkaliphilus MSRD1 has high capacity to produce the pigment with antibacterial properties. This could be effectively used in the future.

  9. RESPONSES OF OYSTERS AND THEIR HEMOCYTES TO CLINICAL AND ENVIRONMENTAL ISOLATES OF VIBRIO PARAHAEMOLYTICUS

    EPA Science Inventory

    Interactions of Vibrio parahaemolyticus with oysters and oyster hemocytes were studied using three environmental isolates (1094, 1163 and ATCC 17802) and three clinical isolates (2030, 2062, 2107). Clinical isolates were from patients who became ill during the June 1998 food pois...

  10. Biofilm-Forming Capacity in Biogenic Amine-Producing Bacteria Isolated from Dairy Products

    PubMed Central

    Diaz, Maria; Ladero, Victor; del Rio, Beatriz; Redruello, Begoña; Fernández, María; Martin, M. Cruz; Alvarez, Miguel A.

    2016-01-01

    Biofilms on the surface of food industry equipment are reservoirs of potentially food-contaminating bacteria—both spoilage and pathogenic. However, the capacity of biogenic amine (BA)-producers to form biofilms has remained largely unexamined. BAs are low molecular weight, biologically active compounds that in food can reach concentrations high enough to be a toxicological hazard. Fermented foods, especially some types of cheese, accumulate the highest BA concentrations of all. The present work examines the biofilm-forming capacity of 56 BA-producing strains belonging to three genera and 10 species (12 Enterococcus faecalis, 6 Enterococcus faecium, 6 Enterococcus durans, 1 Enterococcus hirae, 12 Lactococcus lactis, 7 Lactobacillus vaginalis, 2 Lactobacillus curvatus, 2 Lactobacillus brevis, 1 Lactobacillus reuteri, and 7 Lactobacillus parabuchneri), all isolated from dairy products. Strains of all the tested species - except for L. vaginalis—were able to produce biofilms on polystyrene and adhered to stainless steel. However, the biomass produced in biofilms was strain-dependent. These results suggest that biofilms may provide a route via which fermented foods can become contaminated by BA-producing microorganisms. PMID:27242675

  11. Isolation of an exopolysaccharide-producing heavy metal-resistant Halomonas sp. MG.

    PubMed

    Govarthanan, Muthusamy; Shim, Jaehong; Praburaman, Loganathan; Kim, Seol Ah; Oh, Byung-Taek

    2016-03-01

    An exopolysaccharide (EPS)-producing heavy metal-resistant Gram-negative bacterium was isolated from ore-contaminated soil. The selected strain was identified by 16S rDNA sequencing and designated as Halomonas sp. MG. Phylogenetic analysis of the gene sequence showed its close similarity with Halomonas sp. Field emission scanning electron microscopy analysis revealed that the EPS had a porous structure with small pores. X-ray diffractograms showed the non-crystalline nature of the EPS. Further, FTIR spectroscopic analysis revealed the presence of carboxyl, hydroxyl and amide groups corresponding to a typical EPS.

  12. A survey of IgA protease production among clinical isolates of Proteeae.

    PubMed

    Senior, B W; Albrechtsen, M; Kerr, M A

    1988-01-01

    A collection of 100 strains of Proteeae, in which all species within the tribe were represented, was examined for IgA protease production. The strains were isolated from various clinical specimens from sick and healthy persons in several countries. IgA protease-producing strains were not found amongst species of Providencia and Morganella but were common in Proteus spp. All the strains of P. mirabilis and P. penneri and many of the strains of P. vulgaris examined produced an EDTA-sensitive protease that cleaved the IgA heavy chain outside the hinge region. The proteus enzyme was different in this respect from the EDTA-sensitive, hinge-cutting proteases of other bacteria. The ability to produce IgA protease was unrelated to the O antigenicity, biotype or bacteriocin type of the strain. IgA protease production may be an important virulence mechanism for Proteus strains.

  13. The Clinical Spectrum of Isolated Peripheral Motor Dysfunction

    PubMed Central

    Sanderson, Alan B.; Arnold, W. David; Elsheikh, Bakri; Kissel, John T.

    2015-01-01

    Introduction Isolated peripheral motor dysfunction due to lower motor neuron or peripheral nerve disorders presents an interesting challenge to clinicians because of the diverse differential diagnosis with a broad range of prognoses. Methods We retrospectively reviewed clinical data of adults who presented over 12 years with muscle weakness, atrophy, or fasciculations, but without hyperreflexia or sensory involvement. Results In 119 patients, 52% had a motor neuron disease (MND), 13% had immune neuropathies, 11% had genetic neuronopathies, 10% had residual or post-polio syndrome, 5% had benign fasciculation, 1% had an infectious etiology, and 8% were not given a final diagnosis. Only MND patients had cognitive dysfunction or frontal release signs. Bulbar and respiratory symptoms virtually excluded consideration of immune neuropathy. Conclusions Only half of the patients were diagnosed with MND. A significant minority have treatable conditions. Cognitive involvement, frontal release signs, and bulbar or respiratory symptoms are strongly suggestive of MND. PMID:25042002

  14. Diversity of polymyxin resistance mechanisms among Acinetobacter baumannii clinical isolates.

    PubMed

    Girardello, Raquel; Visconde, Marina; Cayô, Rodrigo; Figueiredo, Regina Célia Bressan Queiroz de; Mori, Marcelo Alves da Silva; Lincopan, Nilton; Gales, Ana Cristina

    2017-01-01

    Polymyxins have become drugs of last resort for treatment of multi-drug resistant (MDR) Gram-negative infections. However, the mechanisms of resistance to this compound have not been completely elucidated. In this study, we evaluated the mechanisms of resistance to this antimicrobial in two A. baumannii clinical isolates, respectively, susceptible (A027) and resistant (A009) to polymyxin B before and after polymyxin B exposure (A027(ind) and A009(ind)). The pmrAB and lpxACD were sequenced and their transcriptional levels were analyzed by qRT-PCR. The bacterial cell morphology was evaluated by transmission electronic microscopy (TEM) and the membrane potential was measured using Zeta-potential analyzer. The virulence of strains was studied using a Caenorhabditis elegans model. Both clinical isolates exhibited an elevation of the polymyxin B MIC after exposure to this compound. On the other hand, A027(ind) showed decreased values of MIC for β-lactams, aminoglycosides, vancomycin, teicoplanin, oxacillin and erythromycin. A027(ind) harbored two mutations in pmrB and the ISAba125 disrupting the lpxA. In contrast, A009(ind) strain exhibited increase of pmrB transcriptional level, after polymyxin B exposure, despite the absence of mutations in the pmrAB genes. The TEM images revealed a thicker and more electron-dense peptidoglycan layer for A009 than that of A027. The exposure to polymyxin B induced a strong condensation and darkening of intracellular material, mainly in A009(ind). In addition, the surface charge of A009 was significantly less negative than the one of A027. Using the C. elegans model, only A027(ind) strain showed a reduction on virulence. The diversity of polymyxin B resistance mechanisms among A. baumannii strains evaluated in this study confirms the complexity of these mechanisms, which may vary depending of the background of each strain.

  15. Plasmid carriage of bla NDM-1 in clinical Acinetobacter baumannii isolates from India.

    PubMed

    Jones, Lim S; Toleman, Mark A; Weeks, Janis L; Howe, Robin A; Walsh, Timothy R; Kumarasamy, Karthikeyan K

    2014-07-01

    NDM-1 probably emerged in Acinetobacter species prior to its dissemination among Enterobacteriaceae, and NDM-1-like enzymes are increasingly reported in Acinetobacter species. Here, we report on the genetic context of blaNDM-1 in the earliest known NDM-1-producing organisms, clinical isolates of Acinetobacter from India in 2005. These strains harbor blaNDM-1 plasmids of different sizes. The gene is associated with the remnants of the Tn125 transposon normally associated with blaNDM-1 in Acinetobacter spp. The transposon has been disrupted by the IS26 insertion and subsequent movement events.

  16. [Characteristics of selected virulence factors of Enterobacter cloacae strains isolated from clinical specimens].

    PubMed

    Nieradko, Józef; Kurlenda, Juliana

    2004-01-01

    We demonstrated that Enterobacter cloacae possesses a selective haemolytic activity on sheep erythrocytes. All the screened strains showed a haemolytic activity on sheep erythrocytes when cultures were preincubated with beta-mercaptoethanol. The investigation circulation of the genes encoding extended spectrum beta-lactamases (ESBL) shows that beta-lactamase producers can be ascribed to specific patterns of plasmids. We also demonstrated that genetic material from E. coli can be transferred and established in selected Enterobacter cloacae strains. In a survival tests we demonstrated that similarly to Salmonella or Vibrio clinical isolates Enterobacter cloacae doesn't demonstrate acid tolerance.

  17. Chemical isolation of quartz for measurement of in-situ-produced cosmogenic nuclides

    NASA Technical Reports Server (NTRS)

    Kohl, C. P.; Nishiizumi, K.

    1992-01-01

    An isolation method relying totally on chemical steps was developed to separate large quantities (10-200 g) of clean mono-minerallic quartz samples from a variety of terrestrial rocks and soils for the purpose of measuring Be-10 (t1/2 = 1.5 Myr) and Al-26 (t1/2 = 0.705 Myr) produced by cosmic rays in situ in the quartz phase. The procedure consists of grinding the sample, heating it in HCl, and treating it with a series of leaches using a dilute HF/HNO3 mixture in a heated ultrasonic tank. The purified quartz was also used for the measurements of in situ cosmic-ray-produced Ne-21 and C-14 (t1/2 = 5730 yr). The method is applicable to any problem requiring purified quartz on a large scale.

  18. Supporting data for identification of biosurfactant-producing bacteria isolated from agro-food industrial effluent.

    PubMed

    Fulazzaky, Mohamad Ali; Abdullah, Shakila; Salim, Mohd Razman

    2016-06-01

    The goal of this study was to identify the biosurfactant-producing bacteria isolated from agro-food industrial effluet. The identification of the potential bacterial strain using a polymerase chain reaction of the 16S rRNA gene analysis was closely related to Serratia marcescens with its recorded strain of SA30 "Fundamentals of mass transfer and kinetics for biosorption of oil and grease from agro-food industrial effluent by Serratia marcescens SA30" (Fulazzaky et al., 2015) [1]; however, many biochemical tests have not been published yet. The biochemical tests of biosurfactant production, haemolytic assay and cell surface hydrophobicity were performed to investigate the beneficial strain of biosurfactant-producing bacteria. Here we do share data collected from the biochemical tests to get a better understanding of the use of Serratia marcescens SA30 to degrade oil, which contributes the technical features of strengthening the biological treatment of oil-contaminated wastewater in tropical environments.

  19. Experimental arthritis induced by a clinical Mycoplasma fermentans isolate

    PubMed Central

    Rivera, Antonio; Yáñez, Antonio; León-Tello, Gloria; Gil, Constantino; Giono, Silvia; Barba, Eduardo; Cedillo, Lilia

    2002-01-01

    Background Mycoplasma fermentans has been associated with rheumatoid arthritis. Recently, it was detected in the joints and blood of patients with rheumatoid arthritis, but it is not clear yet how the bacteria enter the body and reach the joints. The purpose of this study was to determine the ability of M. fermentans to induce experimental arthritis in rabbits following inoculation of the bacteria in the trachea and knee joints. Methods P-140 and PG-18 strains were each injected in the knee joints of 14 rabbits in order to evaluate and compare their arthritogenicity. P-140 was also injected in the trachea of 14 rabbits in order to test the ability of the bacteria to reach the joints and induce arthritis. Results M. fermentans produced an acute arthritis in rabbits. Joint swelling appeared first in rabbits injected with P-140, which caused a more severe arthritis than PG-18. Both strains were able to migrate to the uninoculated knee joints and they were detected viable in the joints all along the duration of the experiment. Changes in the synovial tissue were more severe by the end of the experiment and characterized by the infiltration of neutrophils and substitution of adipose tissue by connective tissue. Rabbits intracheally injected with P-140 showed induced arthritis and the bacteria could be isolated from lungs, blood, heart, kidney, spleen, brain and joints. Conclusion M. fermentans induced arthritis regardless of the inoculation route. These findings may help explain why mycoplasmas are commonly isolated from the joints of rheumatic patients. PMID:12057023

  20. Lactate-utilizing bacteria, isolated from human feces, that produce butyrate as a major fermentation product.

    PubMed

    Duncan, Sylvia H; Louis, Petra; Flint, Harry J

    2004-10-01

    The microbial community of the human colon contains many bacteria that produce lactic acid, but lactate is normally detected only at low concentrations (<5 mM) in feces from healthy individuals. It is not clear, however, which bacteria are mainly responsible for lactate utilization in the human colon. Here, bacteria able to utilize lactate and produce butyrate were identified among isolates obtained from 10(-8) dilutions of fecal samples from five different subjects. Out of nine such strains identified, four were found to be related to Eubacterium hallii and two to Anaerostipes caccae, while the remaining three represent a new species within clostridial cluster XIVa based on their 16S rRNA sequences. Significant ability to utilize lactate was not detected in the butyrate-producing species Roseburia intestinalis, Eubacterium rectale, or Faecalibacterium prausnitzii. Whereas E. hallii and A. caccae strains used both D- and L-lactate, the remaining strains used only the d form. Addition of glucose to batch cultures prevented lactate utilization until the glucose became exhausted. However, when two E. hallii strains and one A. caccae strain were grown in separate cocultures with a starch-utilizing Bifidobacterium adolescentis isolate, with starch as the carbohydrate energy source, the L-lactate produced by B. adolescentis became undetectable and butyrate was formed. Such cross-feeding may help to explain the reported butyrogenic effect of certain dietary substrates, including resistant starch. The abundance of E. hallii in particular in the colonic ecosystem suggests that these bacteria play important roles in preventing lactate accumulation.

  1. Ecto-ATPases of clinical and non-clinical isolates of Acanthamoeba.

    PubMed

    Sissons, James; Alsam, Selwa; Jayasekera, Samantha; Khan, Naveed Ahmed

    2004-11-01

    Acanthamoeba are opportunistic protozoan parasites that can cause fatal granulomatous amoebic encephalitis and eye keratitis, however the pathogenic mechanisms of Acanthamoeba remain unclear. In this study, we described the ability of live Acanthamoeba to hydrolyse extracellular ATP. Both clinical and non-clinical isolates belonging to genotypes, T1, T2, T3, T4 and T7 exhibited ecto-ATPase activities in vitro. Using non-denaturing polyacrylamide gel electrophoresis, ecto-ATPases were further characterized. All Acanthamoeba isolates tested, exhibited a single ecto-ATPase band (approximate molecular weight of 272 kDa). However, clinical isolates exhibited additional bands suggesting that ecto-ATPases may play a role in the pathogenesis of Acanthamoeba. This was supported using suramin (ecto-ATPase inhibitor), which inhibited Acanthamoeba-induced host cell cytotoxicity. Previously, we and others have shown that Acanthamoeba binds to host cells using their mannose-binding protein and binding can be blocked using exogenous alpha-mannose. In this study, we observed that alpha-mannose significantly increased ecto-ATPase activities of pathogenic Acanthamoeba belonging to T1, T2, T3 and T4 genotypes but had no effect on non-pathogenic Acanthamoeba (belonging to T7 genotype). Overall, we have shown, for the first time, that Acanthamoeba exhibit ecto-ATPase activities, which may play a role in the pathogenesis of Acanthamoeba as well as their potential role in the differentiation of pathogenic Acanthamoeba.

  2. Characterization of antibiotic resistant and enzyme producing bacterial strains isolated from the Arabian Sea.

    PubMed

    Tallur, Preeti N; Sajjan, Dayanand B; Mulla, Sikandar I; Talwar, Manjunatha P; Pragasam, A; Nayak, Vinayak M; Ninnekar, Harichandra Z; Bhat, Shivanand S

    2016-06-01

    Marine bacteria are known to produce many bioactive molecules and extracellular enzymes of commercial importance. We have investigated the bacterial diversity of the coastal area of Karwar, Karnataka State, India. Among these bacterial isolates, five bacterial strains were selected and identified by their morphological, biochemical characteristics and phylogenetic analysis based on 16S rRNA gene sequences. The identified bacterial isolates, Bacillus toyonensis PNTB1, Lysinibacillus sphaericus PTB, Vibrio vulnificus PMD, Shewanella MPTDBS, and Pseudomonas chlororaphis PNTB were characterized for their tolerance to salt and antibiotics. Vibrio vulnificus PMD showed maximum tolerance at higher concentration of salt than other bacteria. These bacterial strains were screened for the production of extracellular enzymes such as lipase, cellulase, pectinase, tannase, chitinase, and L-glutaminase. Vibrio vulnificus showed maximum production of L-glutaminase enzyme. Bacillus toyonensis PNTB1 shows lipase, CM-cellulase and chitinase activities. These isolated bacterial cultures were also utilized most of the aromatic compounds at 7 mM. These findings indicate the organisms present in this zone may have more potential applications in bioremediation, agricultural, industrial, and therapeutics.

  3. Protease characteristics of bacteriocin producing Lysinibacilli, isolated from fruits and vegetable waste

    PubMed Central

    Ahmad, Varish; Kamal, Azhar; Ahmad, Khurshid; Khan, Mohd Sajid

    2014-01-01

    This study describes the physical stability and optimization of nutrient components for an extracellular protease produced by Bacillus strains isolated from fruits and vegetable waste, Lucknow, India. The isolated proteases could hydrolyze various native proteinaceous substrates such as bovine serum albumin, casein, skim milk, but not the gelatin. The strain JX416854 and isolate 10 yielded maximum protease (831; 703 U/ml) under optimized conditions: Nutrient, Casein broth; pH 7.0; shaking condition 37°C for 36 h. Crude protease exhibited activity over a wide range of pH (6.0–10.0) and found to be stable at (10–70°C), pH stable at 7- 9.0. The significant protease activity was observed with divalent cations Ca2+ and Mg2+ and EDTA. Further, significant blood destaining properties and stabilities with detergents were also observed. Thus, the significant potency and stability of these enzymes indicated their industrial importance and could be an alternative protease for various industrial applications. PMID:24516320

  4. Isolation and characterization of new Metschnikowia pulcherrima strains as producers of the antimicrobial pigment pulcherrimin.

    PubMed

    Türkel, Sezai; Ener, Beyza

    2009-01-01

    Metschnikowia pulcherrima is a highly effective biocontrol yeast due to its pigment pulcherrimin that accumulates in the cells and in the growth medium. Three different strains of M. pulcherrima were isolated from local grapes. The yeast isolates were characterized on the basis of their biochemical, physiological and ITS1-5.8 s rDNA-ITS2 region. Based on the obtained results, the M. pulcherrima isolates were identified as new strains of M. pulcherrima. Strong antagonistic activities of the M. pulcherrima strains on the human pathogens Proteus vulgaris, Escherichia coli, Candida albicans, Candida parapsilosis, Candida krusei, and Trichosporon mucoides were determined. In addition, antagonistic effects of these M. pulcherrima strains were also tested against Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Trichoderma spp., Paecilomyces spp., and Bipolaris spp. and it was shown that the three different strains of M. pulcherrima also have an antagonistic effect on the growth of these fungal species at different extents. This study showed that all three strains of M. pulcherrima produce the same amount of the pigment pulcherrimin, but their antimicrobial activities on different microorganisms show important variations.

  5. Diversity of Saccharomyces cerevisiae Strains Isolated from Two Italian Wine-Producing Regions.

    PubMed

    Capece, Angela; Granchi, Lisa; Guerrini, Simona; Mangani, Silvia; Romaniello, Rossana; Vincenzini, Massimo; Romano, Patrizia

    2016-01-01

    Numerous studies, based on different molecular techniques analyzing DNA polymorphism, have provided evidence that indigenous Saccharomyces cerevisiae populations display biogeographic patterns. Since the differentiated populations of S. cerevisiae seem to be responsible for the regional identity of wine, the aim of this work was to assess a possible relationship between the diversity and the geographical origin of indigenous S. cerevisiae isolates from two different Italian wine-producing regions (Tuscany and Basilicata). For this purpose, sixty-three isolates from Aglianico del Vulture grape must (main cultivar in the Basilicata region) and from Sangiovese grape must (main cultivar in the Tuscany region) were characterized genotypically, by mitochondrial DNA restriction analysis and MSP-PCR by using (GTG)5 primers, and phenotypically, by determining technological properties and metabolic compounds of oenological interest after alcoholic fermentation. All the S. cerevisiae isolates from each region were inoculated both in must obtained from Aglianico grape and in must obtained from Sangiovese grape to carry out fermentations at laboratory-scale. Numerical analysis of DNA patterns resulting from both molecular methods and principal component analysis of phenotypic data demonstrated a high diversity among the S. cerevisiae strains. Moreover, a correlation between genotypic and phenotypic groups and geographical origin of the strains was found, supporting the concept that there can be a microbial aspect to terroir. Therefore, exploring the diversity of indigenous S. cerevisiae strains can allow developing tailored strategies to select wine yeast strains better adapted to each viticultural area.

  6. Isolation and characterization of a new cellulosome-producing Clostridium thermocellum strain.

    PubMed

    Tachaapaikoon, Chakrit; Kosugi, Akihiko; Pason, Patthra; Waeonukul, Rattiya; Ratanakhanokchai, Khanok; Kyu, Khin Lay; Arai, Takamitsu; Murata, Yoshinori; Mori, Yutaka

    2012-02-01

    The anaerobic thermophilic bacterium, Clostridium thermocellum, is a potent cellulolytic microorganism that produces large extracellular multienzyme complexes called cellulosomes. To isolate C. thermocellum organisms that possess effective cellulose-degrading ability, new thermophilic cellulolytic strains were screened from more than 800 samples obtained mainly from agriculture residues in Thailand using microcrystalline cellulose as a carbon source. A new strain, C. thermocellum S14, having high cellulose-degrading ability was isolated from bagasse paper sludge. Cellulosomes prepared from S14 demonstrated faster degradation of microcrystalline cellulose, and 3.4- and 5.6-fold greater Avicelase activity than those from C. thermocellum ATCC27405 and JW20 (ATCC31449), respectively. Scanning electron microscopic analysis showed that S14 had unique cell surface features with few protuberances in contrast to the type strains. In addition, the cellulosome of S14 was resistant to inhibition by cellobiose that is a major end product of cellulose hydrolysis. Saccharification tests conducted using rice straw soaked with sodium hydroxide indicated the cellulosome of S14 released approximately 1.5-fold more total sugars compared to that of ATCC27405. This newly isolated S14 strain has the potential as an enzyme resource for effective lignocellulose degradation.

  7. New tricks of an old enemy: isolates of Fusarium graminearum produce a type A trichothecene mycotoxin.

    PubMed

    Varga, Elisabeth; Wiesenberger, Gerlinde; Hametner, Christian; Ward, Todd J; Dong, Yanhong; Schöfbeck, Denise; McCormick, Susan; Broz, Karen; Stückler, Romana; Schuhmacher, Rainer; Krska, Rudolf; Kistler, H Corby; Berthiller, Franz; Adam, Gerhard

    2015-08-01

    The ubiquitous filamentous fungus Fusarium graminearum causes the important disease Fusarium head blight on various species of cereals, leading to contamination of grains with mycotoxins. In a survey of F. graminearum (sensu stricto) on wheat in North America several novel strains were isolated, which produced none of the known trichothecene mycotoxins despite causing normal disease symptoms. In rice cultures, a new trichothecene mycotoxin (named NX-2) was characterized by liquid chromatography-tandem mass spectrometry. Nuclear magnetic resonance measurements identified NX-2 as 3α-acetoxy-7α,15-dihydroxy-12,13-epoxytrichothec-9-ene. Compared with the well-known 3-acetyl-deoxynivalenol (3-ADON), it lacks the keto group at C-8 and hence is a type A trichothecene. Wheat ears inoculated with the isolated strains revealed a 10-fold higher contamination with its deacetylated form, named NX-3, (up to 540 mg kg(-1) ) compared with NX-2. The toxicities of the novel mycotoxins were evaluated utilizing two in vitro translation assays and the alga Chlamydomonas reinhardtii. NX-3 inhibits protein biosynthesis to almost the same extent as the prominent mycotoxin deoxynivalenol, while NX-2 is far less toxic, similar to 3-ADON. Genetic analysis revealed a different TRI1 allele in the N-isolates, which was verified to be responsible for the difference in hydroxylation at C-8.

  8. Diversity of Saccharomyces cerevisiae Strains Isolated from Two Italian Wine-Producing Regions

    PubMed Central

    Capece, Angela; Granchi, Lisa; Guerrini, Simona; Mangani, Silvia; Romaniello, Rossana; Vincenzini, Massimo; Romano, Patrizia

    2016-01-01

    Numerous studies, based on different molecular techniques analyzing DNA polymorphism, have provided evidence that indigenous Saccharomyces cerevisiae populations display biogeographic patterns. Since the differentiated populations of S. cerevisiae seem to be responsible for the regional identity of wine, the aim of this work was to assess a possible relationship between the diversity and the geographical origin of indigenous S. cerevisiae isolates from two different Italian wine-producing regions (Tuscany and Basilicata). For this purpose, sixty-three isolates from Aglianico del Vulture grape must (main cultivar in the Basilicata region) and from Sangiovese grape must (main cultivar in the Tuscany region) were characterized genotypically, by mitochondrial DNA restriction analysis and MSP-PCR by using (GTG)5 primers, and phenotypically, by determining technological properties and metabolic compounds of oenological interest after alcoholic fermentation. All the S. cerevisiae isolates from each region were inoculated both in must obtained from Aglianico grape and in must obtained from Sangiovese grape to carry out fermentations at laboratory-scale. Numerical analysis of DNA patterns resulting from both molecular methods and principal component analysis of phenotypic data demonstrated a high diversity among the S. cerevisiae strains. Moreover, a correlation between genotypic and phenotypic groups and geographical origin of the strains was found, supporting the concept that there can be a microbial aspect to terroir. Therefore, exploring the diversity of indigenous S. cerevisiae strains can allow developing tailored strategies to select wine yeast strains better adapted to each viticultural area. PMID:27446054

  9. Subtyping Escherichia coli Virulence Genes Isolated from Feces of Beef Cattle and Clinical Cases in Alberta.

    PubMed

    Tostes, Renata; Goji, Noriko; Amoako, Kingsley; Chui, Linda; Kastelic, John; DeVinney, Rebekah; Stanford, Kim; Reuter, Tim

    2017-01-01

    Clinical outcomes of Shiga toxin (stx)-producing Escherichia coli infection are largely determined by virulence gene subtypes. This study used a polymerase chain reaction (PCR)-pyrosequencing assay to analyze single-nucleotide polymorphisms for subtyping three major virulence genes (stx1, stx2, eae) of pathogenic E. coli (O157, O26, O111, and O103) isolated from cattle over a 2-year interval (n = 465) and human clinical cases (n = 42) in western Canada. Most bovine isolates were PCR positive for at least one target virulence gene (367/465), whereas 100% of human isolates harbored eae in combination with at least one stx gene. Four Shiga toxin (1a, 2a, 2c, and 2e) and four eae (λ/γ1-eae, ɛ-eae, θ/γ2-eae, and β-eae) subtypes were identified in over 25 distinct virulence genotypes. Among cattle isolates, every serogroup, but O103, presented a dominant genotype (O157: stx1a+stx2a+λ/γ1-eae, O26: β-eae alone, and O111: stx1a+θ/γ2-eae). Similar patterns were found in human isolates, although it was not possible to establish a clear genotypic association between the two sources. Many O157 and non-O157 cattle isolates lacked stx genes; the absence was greater in non-O157 (75/258) and O157:non-H7 (19/40) than in O157:H7 strains (1/164). In addition, there was a greater diversity of virulence genotypes of E. coli isolated from cattle than those of human diseases, which could be due to sample characteristics (e.g., source and clinical condition). However, the majority of cattle strains had virulence profiles identical to those of clinical cases. Consequently, determining the presence of certain stx (stx1a and stx2a) and eae (λ/γ1-eae) subtypes known to cause human disease would be a valuable tool for risk assessment and prediction of disease outcome along the farm-to-fork continuum.

  10. Preliminary characterization of biosurfactants produced by microorganisms isolated from refinery wastewaters.

    PubMed

    Yalçin, Emine; Ergene, Aysun

    2010-02-01

    Some bacterial strains isolated from refinery wastewaters were identified as Pseudomonas aeruginosa RWI, Pseudomonas putida RWII, Pseudomonas fluorescens RWIII and Burkholderia cepacia RWIV, and the biosurfactants produced by these strains were coded as BS-I, BS-II, BS-III and BS-IV, respectively. The bacterial strains were characterized by the following biochemical methods: Gram stain, oxidase activity, indol, lactose and growth at 42 degrees C. Biosurfactant production was evaluated by: emulsification activity, surface tension measurement and critical micelle concentration. Chemical characterization of the biosurfactants was done by: FTIR and analysis of carbohydrate, protein and lipid content. The biosurfactants showed good emulsification activity against different hydrocarbon sources. The initial surface tension of culture broth was determined as 67.3 mN/m, and production of BS-I, BS-II, BS-III and BS-IV lowered this value to 35.9, 49.2, 51.6 and 45.7 mN/m, respectively. The critical micelle concentration of the biosurfactants was found to be in the range 10-50 mg/L. From the results of this study it was observed that the refinery wastewaters are a suitable source for isolation of biosurfactant-producing bacteria, but are not a substrate for biosurfactant production.

  11. First Draft Genome Sequences of Malaysian Clinical Isolates of Corynebacterium diphtheriae

    PubMed Central

    Ahmad, Norazah; Mohd Khalid, Mohd Khairul Nizam; Abd Wahab, Muhammad Adib; Hashim, Rohaidah; Tang, Soo Nee; Liow, Yii Ling; Hamzah, Hazwani; Dahalan, Nurul Ain; Seradja, Valentinus

    2017-01-01

    ABSTRACT Corynebacterium diphtheriae has caused multiple isolated diphtheria cases in Malaysia over the years. Here, we report the first draft genome sequences of 15 Malaysia C. diphtheriae clinical isolates collected from the years 1981 to 2016. PMID:28254972

  12. First Draft Genome Sequences of Malaysian Clinical Isolates of Corynebacterium diphtheriae.

    PubMed

    Ahmad, Norazah; Hii, Shirley Yi Fen; Mohd Khalid, Mohd Khairul Nizam; Abd Wahab, Muhammad Adib; Hashim, Rohaidah; Tang, Soo Nee; Liow, Yii Ling; Hamzah, Hazwani; Dahalan, Nurul Ain; Seradja, Valentinus

    2017-03-02

    Corynebacterium diphtheriae has caused multiple isolated diphtheria cases in Malaysia over the years. Here, we report the first draft genome sequences of 15 Malaysia C. diphtheriae clinical isolates collected from the years 1981 to 2016.

  13. Nontuberculous mycobacteria: Reports of clinical laboratory isolation in a three county area, North Carolina, 2006 -2010

    EPA Science Inventory

    Background: Laboratory reports of mycobacteria isolation and identification are created during the clinical diagnostic process to differentiate Mycobacterium tuberculosis from nontuberculous mycobacteria (NTM). NTM isolation rates are expected to exceed rates of true NTM infectio...

  14. Isolation of an antimicrobial compound produced by bacteria associated with reef-building corals

    PubMed Central

    Tapiolas, Dianne; Motti, Cherie A.; Foret, Sylvain; Tebben, Jan; Willis, Bette L.; Bourne, David G.

    2016-01-01

    Bacterial communities associated with healthy corals produce antimicrobial compounds that inhibit the colonization and growth of invasive microbes and potential pathogens. To date, however, bacteria-derived antimicrobial molecules have not been identified in reef-building corals. Here, we report the isolation of an antimicrobial compound produced by Pseudovibrio sp. P12, a common and abundant coral-associated bacterium. This strain was capable of metabolizing dimethylsulfoniopropionate (DMSP), a sulfur molecule produced in high concentrations by reef-building corals and playing a role in structuring their bacterial communities. Bioassay-guided fractionation coupled with nuclear magnetic resonance (NMR) and mass spectrometry (MS), identified the antimicrobial as tropodithietic acid (TDA), a sulfur-containing compound likely derived from DMSP catabolism. TDA was produced in large quantities by Pseudovibrio sp., and prevented the growth of two previously identified coral pathogens, Vibrio coralliilyticus and V. owensii, at very low concentrations (0.5 μg/mL) in agar diffusion assays. Genome sequencing of Pseudovibrio sp. P12 identified gene homologs likely involved in the metabolism of DMSP and production of TDA. These results provide additional evidence for the integral role of DMSP in structuring coral-associated bacterial communities and underline the potential of these DMSP-metabolizing microbes to contribute to coral disease prevention. PMID:27602265

  15. The isolation and functional identification on producing cellulase of Pseudomonas mendocina.

    PubMed

    Zhang, Jianfeng; Hou, Hongyan; Chen, Guang; Wang, Shusheng; Zhang, Jiejing

    2016-09-02

    The straw can be degraded efficiently into humus by powerful enzymes from microorganisms, resulting in the accelerated circulation of N,P,K and other effective elements in ecological system. We isolated a strain through screening the straw degradation strains from natural humic straw in the low temperature area in northeast of china, which can produce cellulase efficiently. The strain was identified as Pseudomonas mendocina by using morphological, physiological, biochemical test, and molecular biological test, with the functional clarification on producing cellulase for Pseudomonas mendocina for the first time. The enzyme force constant Km and the maximum reaction rate (Vmax) of the strain were 0.3261 g/L and 0.1525 mg/(min.L) through the enzyme activity detection, and the molecular weight of the enzyme produced by the strain were 42.4 kD and 20.4 kD based on SDS-PAGE. The effects of various ecological factors such as temperature, pH and nematodes on the enzyme produced by the strain in the micro ecosystem in plant roots were evaluated. The result showed that the optimum temperature was 28°C, and the best pH was 7.4∼7.8, the impact heavy metal was Pb(2+) and the enzyme activity and biomass of Pseudomonas mendocina increased the movement and predation of nematodes.

  16. Isolation and properties of a Bacillus subtilis mutant unable to produce fructose-bisphosphatase.

    PubMed Central

    Fujita, Y; Freese, E

    1981-01-01

    A Bacillus subtilis mutation (gene symbol fdpA1), producing a deficiency of D-fructose-1,6-bisphosphate 1-phosphohydrolase (EC 3.1.3.11, fructose-bisphosphatase), was isolated and genetically purified. An fdpA1-containing mutant did not produce cross-reacting material. It grew on any carbon source that allowed growth of the standard strain except myo-inositol and D-gluconate. Because the mutant could grow on D-fructose, glycerol, or L-malate as the sole carbon source, B. subtilis can produce fructose-6-phosphate and the derived cell wall precursors from these carbon sources in the absence of fructose-bisphosphatase. In other words, during gluconeogenesis B. subtilis must be able to bypass this reaction. Fructose-bisphosphatase is also not needed for the sporulation of B., subtilis. The fdpA1 mutation has the pleiotropic consequence that mutants carrying it cannot produce inositol dehydrogenase (EC 1.1.1.18) and gluconate kinase (EC 2.7.1.12) under conditions that normally induce these enzymes. Images PMID:6257649

  17. Extended-Spectrum β-Lactamase- and Carbapenemase-Producing Enterobacteriaceae Isolated from Egyptian Patients with Suspected Blood Stream Infection

    PubMed Central

    Abdallah, H. M.; Wintermans, B. B.; Reuland, E. A.; Koek, A; al Naiemi, N.; Ammar, A. M.; Mohamed, A. A.; Vandenbroucke-Grauls, C. M. J. E.

    2015-01-01

    Objectives The aim of the study was to investigate the prevalence of extended-spectrum β-lactamase and carbapenemase production among Enterobacteriaceae isolated from Egyptian patients with suspected blood stream infection. Methods Ninety-four Enterobacteriaceae blood culture isolates from Egyptian patients with suspected blood stream infection were collected, one isolate per patient. Identification of bacterial isolates was performed with MALDI-TOF (MS-based Vitek MS system, bioMerieux). Screening for ESBLs and carbapenemases production was done with the Vitek 2 system (bioMérieux). ESBL production was confirmed using the combined disk diffusion method for cefotaxime, ceftazidime, and cefepime, all with and without clavulanic acid (Rosco). Real-time PCR and sequencing were used to characterize the resistance genes. The phylogenetic groups of E. coli were identified by a PCR-based method. Results Of the 94 Enterobacteriaceae isolates 46 (48.93%) showed an ESBL phenotype. One Enterobacter spp isolate was ESBL-producer and meropenem-resistant. The genetic analysis showed that CTX-M was present in 89.13% (41/46) of the ESBL-producing Enterobacteriaceae, whereas TEM and SHV were detected in 56.52% (26/46) and 21.74% (10/46) respectively (47.83%) of the ESBL-producing isolates were multidrug resistant (MDR). Eleven out of 30 ESBL-producing E-coli isolates were assigned to phylogroup B2, followed by groups B1 (8 isolates), A (6 isolates) and D (5 isolates). Conclusions The high ESBL-E rates (48.93%) found in this study together with the identification of one carbapenem-resistant Enterobacter spp isolate is worrisome. Our results indicate that systems for monitoring and detection of ESBL-producing bacteria in Egyptian hospitals have to be established. Also strict hospital infection control policies with the restriction of the consumption of extended-spectrum cephalosporins are necessary. PMID:26001049

  18. Virulence characterization of non-O157 Shiga toxin-producing Escherichia coli isolates from food, humans and animals.

    PubMed

    Shen, Jinling; Rump, Lydia; Ju, Wenting; Shao, Jingdong; Zhao, Shaohua; Brown, Eric; Meng, Jianghong

    2015-09-01

    A total of 359 non-O157 STEC isolates from food, humans and animals were examined for serotypes, Shiga toxin subtypes and intimin subtypes. Isolates solely harboring stx2 from the three sources were selected for Vero cell cytotoxicity test. stx subtypes in eae negative isolates were more diverse than in eae positive isolates primarily carrying stx2a. Four eae subtypes (eaeβ,eaeε1,eaeγ1 and eaeγ2/θ) were observed and correlated with serotypes and flagella. Food isolates showed more diverse serotypes, virulence factors and cell cytotoxicities than human isolates. Some isolates from produce belonged to serotypes that have been implicated in human diseases, carried stx2a or/and stx2dact and exhibited high cell cytotoxicity similar to human isolates. This indicates that foods can be contaminated with potentially pathogenic STEC isolates that may cause human diseases. Given the increased produce consumption and growing burden of foodborne outbreaks due to produce, produce safety should be given great importance.

  19. The Mitochondrial Toxin Produced by Streptomyces griseus Strains Isolated from an Indoor Environment Is Valinomycin

    PubMed Central

    Andersson, M. A.; Mikkola, R.; Kroppenstedt, R. M.; Rainey, F. A.; Peltola, J.; Helin, J.; Sivonen, K.; Salkinoja-Salonen, M. S.

    1998-01-01

    Actinomycete isolates from indoor air and dust in water-damaged schools and children’s day care centers were tested for toxicity by using boar spermatozoa as an indicator. Toxicity was detected in extracts of four strains which caused a loss of sperm motility, and the 50% effective concentrations (EC50) were 10 to 63 ng (dry weight) ml of extended boar semen−1. The four strains were identified as Streptomyces griseus strains by 16S ribosomal DNA and chemotaxonomic methods. The four S. griseus strains had similar effects on sperm cells, including loss of motility and swelling of mitochondria, but we observed no loss of plasma membrane integrity or depletion of cellular ATP. None of the effects was observed with sperm cells exposed to extracts of other indoor actinomycete isolates at concentrations of ≥5,000 to 72,000 ng ml−1. The toxin was purified from all four strains and was identified as a dodecadepsipeptide, and the fragmentation pattern obtained by tandem mass spectrometry was identical to that of valinomycin. Commercial valinomycin had effects in sperm cells that were identical to the effects of the four indoor isolates of S. griseus. The EC50 of purified toxin from the S. griseus strains were 1 to 3 ng ml of extended boar semen−1, and the EC50 of commercial valinomycin was 2 ng ml of extended boar semen−1. To our knowledge, this is the first report of the presence of ionophoric toxin producers in an indoor environment and the first report of valinomycin-producing strains identified as S. griseus. PMID:9835560

  20. The hydrolytic enzymes produced by fungi strains isolated from the sand and soil of recreational areas

    PubMed

    Kurnatowski, Piotr; Wójcik, Anna; Błaszkowska, Joanna; Góralska, Katarzyna

    2016-10-01

    The pathogenicity of fungi depends on, inter alia, the secretion of hydrolytic enzymes. The aim of this study was to determine the enzymatic activity of yeasts and yeast-like fungi isolated from children’s recreation areas, and compare the results with literature data of strains obtained from patients with mycoses. The enzymatic activity of 96 strains was assessed using an API ZYM kit (bioMerieux, France) and their biotypes were established. The fungal species were found to produce from 16 to 19 hydrolases: the most active were: leucine arylamidase (e5), acid phosphatase (e10), alkaline phosphatase (e1), naphthol-AS-BI-phosphohydrolase (e11), esterase – C4 (e2), β-galac - tosidase (e13) and β-glucosidase (e16). In addition, 13 biotypes characteristic of particular species of fungi were defined. Most strains could be categorized as biotypes C2 – 39.5% and A – 26%. The examined fungal strains isolated from recreational areas have selected biochemical characteristics i.e. production of hydrolases, which demonstrate their pathogenicity. They produce a number of enzymes which are also present in strains isolated from patients with mycoses, including: leucine arylamidase (e5), acid phosphatase (e10), naphthol-AS-BI-phosphohydrolase (e11) and alkaline phosphatase (e1). The biotypes identified in the course of this study (A, B3, B4, C1, C6 and D3) have been also reported in cases of fungal infection. Therefore, the fungi present in the sand and soil of recreational have pathogenic properties and are possible factors of fungal infection among children.

  1. [Evolution of antimicrobial susceptibility of Acinetobacter baumannii clinical isolates].

    PubMed

    López-Hernández, S; Alarcón, T; López-Brea, M

    2000-12-01

    Acinetobacter baumannii is a microorganism frequently implicated in colonization and infection in hospitalized patients. An increase of resistance has been observed in recent years making these infections difficult to treat. The in vitro activity of 24 antibiotics, 15 betalactam agents and nine nonbetalactams, was studied in 156 A. baumannii clinical isolates. The strains were collected from different clinical samples obtained from inpatients (92%) and 8% were from outpatients. Evolution of susceptibility from January 1995 to December 1997 was studied. MIC of the following antibiotics was determined by the agar dilution method: ampicillin, ticarcillin, piperacillin, ampicillin-sulbactam, amoxicillin- clavulanic acid, ticarcillin-clavulanic acid, piperacillin-tazobactam, cefotaxime, ceftazidime, cefepime, imipenem, meropenem, clavulanic acid, sulbactam, tazobactam, amikacin, gentamicin, tobramycin, ofloxacin, doxycycline, fosfomycin, rifampin, azithromycin and colistin. Low antimicrobial susceptibility was observed in most A. baumannii strains. Colistin, imipenem, meropenem and ampicillin-sulbactam showed the greatest susceptibility (100, 88.4, 88.4 and 84.6%, respectively). A. baumannii strains from inpatients showed a lower antimicrobial susceptibility than strains from outpatients, who showed a high percentage of susceptibility to most antibiotics. Rifampin and azithromycin showed certain in vitro activity against the most susceptible A. baumannii strains. A progressive decrease in susceptibility to most antibiotics was observed during the period studied. Carbapenem-resistant A. baumannii emerged in 1996 and increased in 1997.

  2. Molecular characterization of a clinical Haemophilus parainfluenzae isolate with cefotaxime resistance and decreased susceptibility to fluoroquinolones.

    PubMed

    Faccone, Diego; Lopez-Ruitti, Paula; Vazquez, Miryam; Guerriero, Leonor; Lucero, Celeste; Gagetti, Paula; Ceriana, Paola; Corso, Alejandra

    2016-10-01

    We report an H. parainfluenzae clinical isolate resistant to cefotaxime and with decreased susceptibility to ciprofloxacin recovered from a patient with cystic fibrosis. The isolate had elevated MICs of ampicillin (256mg/L), amoxicillin-clavulanate (8mg/L), cefuroxime (8mg/L) and cefotaxime (4mg/L), and showed a β-lactamase-producing amoxicillin-clavulanic acid-resistant (BLPACR) phenotype. A blaTEM-1 plus five amino acid substitutions in the PBP3 were found: Ser385Thr, Val511Ala, Ile519Val, Asn526Lys and Asp551Leu. MIC of ciprofloxacin was 0.5mg/L, and substitutions in gyrA (Ser84Tyr) and parC (Ser84Phe) genes were detected.

  3. Similar frequencies of Pseudomonas aeruginosa isolates producing KPC and VIM carbapenemases in diverse genetic clones at tertiary-care hospitals in Medellín, Colombia.

    PubMed

    Vanegas, Johanna M; Cienfuegos, Astrid V; Ocampo, Ana M; López, Lucelly; del Corral, Helena; Roncancio, Gustavo; Sierra, Patricia; Echeverri-Toro, Lina; Ospina, Sigifredo; Maldonado, Natalia; Robledo, Carlos; Restrepo, Andrea; Jiménez, J Natalia

    2014-11-01

    Carbapenem-resistant Pseudomonas aeruginosa has become a serious health threat worldwide due to the limited options available for its treatment. Understanding its epidemiology contributes to the control of antibiotic resistance. The aim of this study was to describe the clinical and molecular characteristics of infections caused by carbapenem-resistant P. aeruginosa isolates in five tertiary-care hospitals in Medellín, Colombia. A cross-sectional study was conducted in five tertiary-care hospitals from June 2012 to March 2014. All hospitalized patients infected by carbapenem-resistant P. aeruginosa were included. Clinical information was obtained from medical records. Molecular analyses included PCR for detection of bla(VIM), bla(IMP), bla(NDM), bla(OXA-48), and bla(KPC) genes plus pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) for molecular typing. A total of 235 patients were enrolled: 91.1% of them were adults (n = 214), 88.1% (n = 207) had prior antibiotic use, and 14.9% (n = 35) had urinary tract infections. The bla(VIM-2) and bla(KPC-2) genes were detected in 13.6% (n = 32) and 11.5% (n = 27), respectively, of all isolates. Two isolates harbored both genes simultaneously. For KPC-producing isolates, PFGE revealed closely related strains within each hospital, and sequence types (STs) ST362 and ST235 and two new STs were found by MLST. With PFGE, VIM-producing isolates appeared highly diverse, and MLST revealed ST111 in four hospitals and five new STs. These results show that KPC-producing P. aeruginosa is currently disseminating rapidly and occurring at a frequency similar to that of VIM-producing P. aeruginosa isolates (approximately 1:1 ratio) in Medellín, Colombia. Diverse genetic backgrounds among resistant strains suggest an excessive antibiotic pressure resulting in the selection of resistant strains.

  4. Similar Frequencies of Pseudomonas aeruginosa Isolates Producing KPC and VIM Carbapenemases in Diverse Genetic Clones at Tertiary-Care Hospitals in Medellín, Colombia

    PubMed Central

    Vanegas, Johanna M.; Cienfuegos, Astrid V.; Ocampo, Ana M.; López, Lucelly; del Corral, Helena; Roncancio, Gustavo; Sierra, Patricia; Echeverri-Toro, Lina; Ospina, Sigifredo; Maldonado, Natalia; Robledo, Carlos; Restrepo, Andrea

    2014-01-01

    Carbapenem-resistant Pseudomonas aeruginosa has become a serious health threat worldwide due to the limited options available for its treatment. Understanding its epidemiology contributes to the control of antibiotic resistance. The aim of this study was to describe the clinical and molecular characteristics of infections caused by carbapenem-resistant P. aeruginosa isolates in five tertiary-care hospitals in Medellín, Colombia. A cross-sectional study was conducted in five tertiary-care hospitals from June 2012 to March 2014. All hospitalized patients infected by carbapenem-resistant P. aeruginosa were included. Clinical information was obtained from medical records. Molecular analyses included PCR for detection of blaVIM, blaIMP, blaNDM, blaOXA-48, and blaKPC genes plus pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) for molecular typing. A total of 235 patients were enrolled: 91.1% of them were adults (n = 214), 88.1% (n = 207) had prior antibiotic use, and 14.9% (n = 35) had urinary tract infections. The blaVIM-2 and blaKPC-2 genes were detected in 13.6% (n = 32) and 11.5% (n = 27), respectively, of all isolates. Two isolates harbored both genes simultaneously. For KPC-producing isolates, PFGE revealed closely related strains within each hospital, and sequence types (STs) ST362 and ST235 and two new STs were found by MLST. With PFGE, VIM-producing isolates appeared highly diverse, and MLST revealed ST111 in four hospitals and five new STs. These results show that KPC-producing P. aeruginosa is currently disseminating rapidly and occurring at a frequency similar to that of VIM-producing P. aeruginosa isolates (approximately 1:1 ratio) in Medellín, Colombia. Diverse genetic backgrounds among resistant strains suggest an excessive antibiotic pressure resulting in the selection of resistant strains. PMID:25210071

  5. Geographical and meteorological factors associated with isolation of Listeria species in New York State produce production and natural environments.

    PubMed

    Chapin, Travis K; Nightingale, Kendra K; Worobo, Randy W; Wiedmann, Martin; Strawn, Laura K

    2014-11-01

    Listeria species have been isolated from diverse environments, often at considerable prevalence, and are known to persist in food processing facilities. The presence of Listeria spp. has been suggested to be a marker for Listeria monocytogenes contamination. Therefore, a study was conducted to (i) determine the prevalence and diversity of Listeria spp. in produce production and natural environments and (ii) identify geographical and/or meteorological factors that affect the isolation of Listeria spp. in these environments. These data were also used to evaluate Listeria spp. as index organisms for L. monocytogenes in produce production environments. Environmental samples collected from produce production (n = 588) and natural (n = 734) environments in New York State were microbiologically analyzed to detect and isolate Listeria spp. The prevalence of Listeria spp. was approximately 33 and 34% for samples obtained from natural environments and produce production, respectively. Co-isolation of L. monocytogenes and at least one other species of Listeria in a given sample was recorded for 3 and 9% of samples from natural environments and produce production, respectively. Soil moisture and proximity to water and pastures were highly associated with isolation of Listeria spp. in produce production environments, while elevation, study site, and proximity to pastures were highly associated with isolation of Listeria spp. in natural environments, as determined by randomForest models. These data show that Listeria spp. were prevalent in both agricultural and nonagricultural environments and that geographical and meteorological factors associated with isolation of Listeria spp. were considerably different between the two environments.

  6. Produce isolates of the Escherichia coli Ont:H52 serotype that carry both Shiga toxin 1 and stable toxin genes.

    PubMed

    Monday, Steven R; Keys, Christina; Hanson, Patricia; Shen, Yuelian; Whittam, Thomas S; Feng, Peter

    2006-04-01

    Produce isolates of the Escherichia coli Ont:H52 serotype carried Shiga toxin 1 and stable toxin genes but only expressed Stx1. These strains had pulsed-field gel electrophoresis profiles that were 90% homologous to clinical Ont:H52 strains that had identical phenotypes and genotypes. All Ont:H52 strains had identical single nucleotide polymorphism profiles that are suggestive of a unique clonal group.

  7. Complete Genome Sequence of Serratia marcescens U36365, a Green Pigment–Producing Strain Isolated from a Patient with Urinary Tract Infection

    PubMed Central

    Sahni, Rani Diana; Amalanathan, Rabecca; Devanga Ragupathi, Naveen Kumar; Mathai, John; Veeraraghavan, Balaji

    2016-01-01

    Serratia marcescens is an emerging nosocomial pathogen associated with urinary and respiratory tract infections. In this study, we determined the genome of a green pigment–producing clinical strain, U36365, isolated from a hospital in Southern India. De novo assembly of PacBio long-read sequencing indicates that the U36365 genome consists of a chromosome of 5.12 Mbps and no plasmids. PMID:27516523

  8. Correlation of RAPD-PCR Profiles with ESBL Production in Clinical Isolates of Klebsiella pneumoniae in Tehran

    PubMed Central

    Nouri, Parvaneh

    2015-01-01

    Background: Multidrug resistant K. pneumoniae, particularly the extended-spectrum β-lactamase (ESBL) producing strains, are often responsible for the failure of antibiotic treatment in nosocomial infections. Employing molecular methods to distinguish between ESBL and non-ESBL producing isolates can help quick identification of these multidrug resistant pathogens and thereby initiating appropriate antibiotic therapy. The aim of this study was to employ RAPD-PCR to distinguish the genetic fingerprints of ESBL producing clinical isolates of K. pneumoniae from ESBL negative strains. Materials and Methods: Antibacterial susceptibility of 104 K. pneumoniae clinical isolates was determined to 13 antibacterial agents by disc diffusion. ESBL production was measured by the double disc synergy test followed by phenotypic confirmatory tests. Genetic fingerprinting was carried out by RAPD-PCR. Results: All isolates were susceptible to imipenem. Antibiotic resistance rates were: piperacillin (100%), ceftazidime (62.5%), cefotaxime (57.6%), aztreonam (52.8%), cefepime (51.9%), kanamycin (50.9%), gentamicin (41.3%), ciprofloxacin (37.5%), nitrofurantoin (30.6%), nalidixic acid (22.1%), piperacillin/tazobactam (21.1%) and amikacin (9.6%). ESBL production was observed in 14 isolates (13.4%). Genetic fingerprinting performed on 43 isolates (14 ESBL positive and 29 ESBL negative) by RAPD-PCR, showed that 46.5% of the isolates belonged to a single profile (genotype 1), of which, the majority (62.1%) were non-ESBL producers. Conclusion: RAPD-PCR results showed heterogeneity among the isolates. There was no association between ESBL production with any specific genetic fingerprint. PMID:25737983

  9. Camptothecin-producing endophytic fungus Trichoderma atroviride LY357: isolation, identification, and fermentation conditions optimization for camptothecin production.

    PubMed

    Pu, Xiang; Qu, Xixing; Chen, Fei; Bao, Jinku; Zhang, Guolin; Luo, Yinggang

    2013-11-01

    Camptothecin (CPT), the third largest anticancer drug, is produced mainly by Camptotheca acuminata and Nothapodytes foetida. CPT itself is the starting material for clinical CPT-type drugs, but the plant-derived CPT cannot support the heavy demand from the global market. Research efforts have been made to identify novel sources for CPT. In this study, three CPT-producing endophytic fungi, Aspergillus sp. LY341, Aspergillus sp. LY355, and Trichoderma atroviride LY357, were isolated and identified from C. acuminata. Most CPT produced by these fungi was found in the fermentation broth, and their corresponding CPT yields were 7.93, 42.92, and 197.82 μg l(-1), respectively. The CPT-producing capability of LY341 and LY355 was completely lost after repeat subculturing. A substantial decrease of CPT production was also observed in the second generation of LY357. However, a stable and sustainable production of CPT was found from the second generation through the eighth generation of LY357. The fermentation medium, time, pH, temperature, and agitation rate were optimized for CPT production. Methyl jasmonate and XAD16 were proven to be an optimum elicitor and adsorbent resin, respectively, in view of that CPT yield was increased 3.4- and 11-fold through their use. A 50- to 75-fold increase of CPT yield was obtained when the optimized fermentation conditions, elicitor, and adsorbent resin were combined and applied to the culture of the seventh and eighth generations of LY357, and the highest CPT yield was 142.15 μg l(-1). The CPT-producing T. atroviride LY357 paves a potential to uncover the mysteries of CPT biosynthesis.

  10. Genomic Features of Environmental and Clinical Vibrio parahaemolyticus Isolates Lacking Recognized Virulence Factors Are Dissimilar.

    PubMed

    Ronholm, J; Petronella, N; Chew Leung, C; Pightling, A W; Banerjee, S K

    2015-12-04

    Vibrio parahaemolyticus is a bacterial pathogen that can cause illness after the consumption or handling of contaminated seafood. The primary virulence factors associated with V. parahaemolyticus illness are thermostable direct hemolysin (TDH) and Tdh-related hemolysin (TRH). However, clinical strains lacking tdh and trh have recently been isolated, and these clinical isolates are poorly understood. To help understand the emergence of clinical tdh- and trh-negative isolates, a genomic approach was used to comprehensively compare 4 clinical tdh- and trh-negative isolates with 16 environmental tdh- and trh-negative isolates and 34 clinical isolates positive for tdh or trh, or both, with the objective of identifying genomic features that are unique to clinical tdh- and trh-negative isolates. The prevalence of pathogenicity islands (PAIs) common to clinical isolates was thoroughly examined in each of the clinical tdh- and trh-negative isolates. The tdh PAI was not present in any clinical or environmental tdh- and trh-negative isolates. The trh PAI was not present in any environmental isolates; however, in clinical tdh- and trh-negative isolate 10-4238, the majority of the trh PAI including a partial trh1 gene was present, which resulted in reclassification of this isolate as a tdh-negative and trh-positive isolate. In the other clinical tdh- and trh-negative isolates, neither the trh gene nor the trh PAI was present. We identified 862 genes in clinical tdh- and trh-negative isolates but not in environmental tdh- and trh-negative isolates. Many of these genes are highly homologous to genes found in common enteric bacteria and included genes encoding a number of chemotaxis proteins and a novel putative type VI secretion system (T6SS) effector and immunity protein (T6SS1). The availability of genome sequences from clinical V. parahaemolyticus tdh- and trh-negative isolates and the comparative analysis may help provide an understanding of how this pathotype is able to

  11. Genomic Features of Environmental and Clinical Vibrio parahaemolyticus Isolates Lacking Recognized Virulence Factors Are Dissimilar

    PubMed Central

    Petronella, N.; Chew Leung, C.; Pightling, A. W.; Banerjee, S. K.

    2015-01-01

    Vibrio parahaemolyticus is a bacterial pathogen that can cause illness after the consumption or handling of contaminated seafood. The primary virulence factors associated with V. parahaemolyticus illness are thermostable direct hemolysin (TDH) and Tdh-related hemolysin (TRH). However, clinical strains lacking tdh and trh have recently been isolated, and these clinical isolates are poorly understood. To help understand the emergence of clinical tdh- and trh-negative isolates, a genomic approach was used to comprehensively compare 4 clinical tdh- and trh-negative isolates with 16 environmental tdh- and trh-negative isolates and 34 clinical isolates positive for tdh or trh, or both, with the objective of identifying genomic features that are unique to clinical tdh- and trh-negative isolates. The prevalence of pathogenicity islands (PAIs) common to clinical isolates was thoroughly examined in each of the clinical tdh- and trh-negative isolates. The tdh PAI was not present in any clinical or environmental tdh- and trh-negative isolates. The trh PAI was not present in any environmental isolates; however, in clinical tdh- and trh-negative isolate 10-4238, the majority of the trh PAI including a partial trh1 gene was present, which resulted in reclassification of this isolate as a tdh-negative and trh-positive isolate. In the other clinical tdh- and trh-negative isolates, neither the trh gene nor the trh PAI was present. We identified 862 genes in clinical tdh- and trh-negative isolates but not in environmental tdh- and trh-negative isolates. Many of these genes are highly homologous to genes found in common enteric bacteria and included genes encoding a number of chemotaxis proteins and a novel putative type VI secretion system (T6SS) effector and immunity protein (T6SS1). The availability of genome sequences from clinical V. parahaemolyticus tdh- and trh-negative isolates and the comparative analysis may help provide an understanding of how this pathotype is able to

  12. Surface display vectors for selective detection and isolation of high level antibody producing cells.

    PubMed

    Lang, Sabine; Drewello, Delia; Wichter, Johannes; Nommay, Audrey; Wilms, Burkhard; Knopf, Hans-Peter; Jostock, Thomas

    2016-11-01

    Cell line generation for production of biopharmaceuticals in mammalian cells usually involves intensive screening of clones to identify the rare high producers. In order to facilitate efficient and selective fluorescence activated cell sorting (FACS) based enrichment and cloning of antibody producing CHO cells, we developed a special vector setup by inserting a leaky translation termination signal between the heavy chain of an IgG antibody and an IgG transmembrane domain. Partial read-through during translation of the antibody heavy chain leads to display of a subset of the produced antibody on the surface of the expressing cell. We could show that the level of surface expression correlates well with the productivity. By applying FACS, high producing cells can be selectively enriched and cloned. Two sequential FACS enrichment cycles were performed which led to more than eightfold increased productivities of transfected and selected cell populations without cloning. The combination of selective FACS enrichment and FACS cloning with the new vector setup led to a sevenfold higher average productivity of the resulting clones as compared to a reference vector. Productivity and production stability assessment of clones generated with the new vector showed no negative impact of the co-expression of transmembrane antibody. Clone productivities of 4 g/L in a generic shake flask fed-batch model were achieved. Thus, this new vector setup facilitates fast and selective isolation of high producing production cell lines and allows significant reduction of clone screening efforts during cell line development for production cell lines. Additionally, the high productivity of FACS-enriched but non-clonal cell populations supports rapid, high yield, and cost efficient material production in early project phases. Biotechnol. Bioeng. 2016;113: 2386-2393. © 2016 Wiley Periodicals, Inc.

  13. Draft Genome Sequence of Clostridium bifermentans Strain WYM, a Promising Biohydrogen Producer Isolated from Landfill Leachate Sludge.

    PubMed

    Wong, Y M; Juan, J C; Gan, H M; Austin, C M

    2014-03-06

    Clostridium bifermentans strain WYM is an effective biohydrogen producer isolated from landfill leachate sludge. Here, we present the assembly and annotation of its genome, which may provide further insights into the metabolic pathways involved in efficient biohydrogen production.

  14. Rapid Isolation of Nuclear Transport-Competent Xenopus Nucleoplasmin Produced in Escherichia coli Strain BL21(DE3)

    DTIC Science & Technology

    1994-01-01

    method to produce nuclear transport-competent nucleo-plasmin avoids the lengthy purification procedure used to isolate nucleoplasmin from Xenopus laevis oocytes as well as the cost of purchasing and maintaining a toad colony.

  15. Antifungal susceptibility and virulence factors of clinically isolated dermatophytes in Tehran, Iran

    PubMed Central

    Afshari, Mohammad Ali; Shams-Ghahfarokhi, Masoomeh; Razzaghi-Abyaneh, Mehdi

    2016-01-01

    Background and Objectives: Dermatophytes possess a wide array of virulence factors and various antifungal susceptibility patterns which influence their pathogenesis in humans and animals. The aim of this study was to evaluate antifungal susceptibility and keratinase and proteinase activity of 49 dermatophyte strains from the genera Microsporum, Trichophyton and Epidermophyton which were isolated from human cases of dermatophytosis. Materials and Methods: Forty-nine dermatophyte strains isolated from clinical samples were cultured on general and specific culture media. Keratinase and proteinase activity was screened on solid mineral media and confirmed in liquid cultures. Drug susceptibility toward azoles (fluconazole, ketoconazole and itraconazole), griseofulvin and terbinafine was evaluated using disk diffusion method on Mueller-Hinton agar and minimum inhibitory concentrations (MICs) were determined using microbroth dilution assay according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Our results indicated that clinically isolated dermatophytes from 7 major species produced keratinase and proteinase at different extents. The mean keratinase and proteinase activity was reported as 6.69 ± 0.31 (U/ml) and 2.10 ± 0.22 (U/ml) respectively. Disk diffusion and microbroth dilution (MIC) results of antifungal susceptibility testing showed that ketoconazole was the most effective drug against Epidermophyton floccosum and Trichophyton mentagrophytes, itraconazole against T. rubrum and E. floccosum, and griseofulvin and terbinafine against Trichophyton verrucosum. Our results showed that all dermatophyte isolates were resistant to fluconazole. Overall, ketoconazole and itraconazole were the most effective drugs for all dermatophyte species tested. Conclusion: Our results showed that antifungal susceptibility testing is an urgent need to select drugs of choice for treatment of different types of dermatophytosis and further indicated the

  16. [Clinical consideration of coagulase negative Staphylococci isolated in blood culture].

    PubMed

    Oshitani, Yohei; Ishikawa, Tomoyuki; Murata, Ken; Aoyagi, Yoshiki; Yabe, Yasuyo; Aoshima, Masahiro

    2012-01-01

    Despite blood culture's usefulness in antimicrobial therapy, fewer blood cultures and the infrequency of more than 1 set in cultures appear to be problems in Japan. Since June 2007 infection control team (ICT) recommended more than 1 set in blood sampling and intervention in positive blood culture, coagulase negative Staphylococci (CNS) has frequently been isolated from blood culture and its clinical significance is often difficult to judge. To determine the effect of ICT intervention, we evaluated the number of blood culture specimens, the frequency of more than 1 set in all blood culture specimens, and decision-making on antimicrobial treatment for CNS isolated retrospectively from blood. The study was divided into term I in August 2007 to July 2008, term II in August 2008 to July 2009, and term III in August 2009 to February 2010. We also analyzed how physicians treated infection or its suspicion after CNS and its drug susceptibility. The monthly number of blood culture specimens increased from 40.3 to 51.6 between terms I and III. The frequency of more than 1 set in a single blood culture session rose significantly from 67% to 89% between these terms (p < 0.001). The number of indeterminate also dropped cases significantly during these 2 terms from 27% to 6% (p = 0.017). Infection or suspected infection cases--45 of 49--had central vein catheter implantation. Inappropriate treatment by physicians in these cases also dropped significantly from 85% (11/13) to 45% (5/11) (p = 0.043) during the same 2 terms. ICT Intervention may thus increase the number of blood culture specimens, enable more than 1 set in blood sampling, make it easier to judge the presence of infection, and increase appropriate treatment by physicians. We thus believe that the quality of antimicrobial treatment could be improved through education such as ICT action.

  17. Relationship between clinical site of isolation and ability to form biofilms in vitro in nontypeable Haemophilus influenzae.

    PubMed

    Obaid, Najla A; Jacobson, Glenn A; Tristram, Stephen

    2015-03-01

    Nontypeable Haemophilus influenzae (NTHi) is an opportunistic pathogen associated with a range of infections, including various lower respiratory infections, otitis media, and conjunctivitis. There is some debate as to whether or not NTHi produces biofilms and, if so, whether or not this is relevant to pathogenesis. Although many studies have examined the association between in vitro biofilm formation and isolates from a specific infection type, few have made comparisons from isolates from a broad range of isolates grouped by clinical source. In our study 50 NTHi from different clinical sources, otitis media, conjunctivitis, lower respiratory tract infections in both cystic fibrosis and non-cystic fibrosis patients, and nasopharyngeal carriage, plus 10 nasopharyngeal isolates of the commensal Haemophilus haemolyticus were tested for the ability to form biofilm by using a static microtitre plate crystal violet assay. A high degree of variation in biofilm forming ability was observed across all isolates, with no statistically significant differences observed between the groups, with the exception of the isolates from conjunctivitis. These isolates had uniformly lower biofilm forming ability compared with isolates from the other groups (p < 0.005).

  18. Biofilm formation by Staphylococcus aureus isolates from a dental clinic in Konya, Turkey.

    PubMed

    Torlak, Emrah; Korkut, Emre; Uncu, Ali T; Şener, Yağmur

    2017-02-14

    The ability of Staphylococcus aureus to form biofilm is considered to be a major virulence factor influencing its survival and persistence in both the environment and the host. Biofilm formation in S. aureus is most frequently associated with production of polysaccharide intercellular adhesion by ica operon-encoded enzymes. The present work aimed at evaluating the in vitro biofilm production and presence of the icaA and icaD genes in S. aureus isolates from a dental clinic in Konya, Turkey. The surfaces of inanimate objects were sampled over a period of six months. S. aureus isolates were subjected to Congo Red Agar (CRA) and crystal violet (CV) staining assays to evaluate their ability of biofilm production, while the presence of the icaA and icaD genes was determined by polymerase chain reaction. S. aureus contamination was detected in 13.2% of the environmental samples. All the 32 isolates were observed to be positive for both the icaA and icaD genes. Phenotypic evaluations revealed that CV staining assay is a more reliable alternative to CRA assay to determine biofilm formation ability. A high percentage of agreement (91%) was observed between the results from CV staining and ica genes' detection assays. Phenotypic and genotypic evaluations should be combined to detect biofilm formation in S. aureus. Our findings indicate that dental clinic environments should be considered as potential reservoir for biofilm-producing S. aureus and thus cross contamination.

  19. Virulence Factors and Phenotypical Traits of Verotoxin-Producing Escherichia coli Strains Isolated from Asymptomatic Human Carriers

    PubMed Central

    Stephan, R.; Untermann, F.

    1999-01-01

    Fourteen verotoxin-producing Escherichia coli strains isolated from stool samples of 14 different asymptomatic human carriers were further characterized. A variety of serotypes was found, but none of the strains belonged to serogroup O157. Only one isolate carried most of the virulence genes that are associated with increased pathogenicity. PMID:10203524

  20. Epidemiology and virulence of VIM-4 metallo-beta-lactamase-producing Pseudomonas aeruginosa isolated from burn patients in eastern Algeria.

    PubMed

    Meradji, Samah; Barguigua, Abouddihaj; Bentakouk, Mohamed Cherif; Nayme, Kaotar; Zerouali, Khalid; Mazouz, Dekhil; Chettibi, Houria; Timinouni, Mohammed

    2016-06-01

    In this study, we investigated the prevalence of carbapenem-resistant Pseudomonas aeruginosa (CRPA) in burn patients from eastern Algeria, CRPA virulence factors and the molecular epidemiology of CRPA. The overall prevalence of CRPA was 48.38%. Seven (46.66%) isolates were metallo-β-lactamases (MBL) producers and contained the MBL genes blaVIM-4 (n=6) and blaVIM-2 (n=1). Risk factors for CRPA infection were urinary catheter use and intubation (p=0.008). A high percentage of virulence factors (86.6% of these isolates were able to produce protease; 73.3% of isolates has DNase; and 66.6% were haemolysin positive) was observed in CRPA isolates. Among the seven MBL-producing isolates, four had the same clonal profile. The class 1 integrons, which contained the aadA7 gene cassette, were detected in six isolates. The 16SrRNA methylase gene, rmtB, was detected in one strain. All CRPA isolates were biofilm formers. A study on the kinetics of biofilm production revealed that biofilm production increased when the concentration of imipenem or ciprofloxacin and the incubation time increased. This is the first study to report the presence of VIM-4-producing P. aeruginosa from North Africa and also of the high prevalence of CRPA isolates. Based on our study of burn unit patients, the high percentage of P. aeruginosa with virulence factors and multi-drug resistance is alarming.

  1. Clinical MRSA isolates from skin and soft tissue infections show increased in vitro production of phenol soluble modulins

    PubMed Central

    Berlon, Nicholas R.; Qi, Robert; Sharma-Kuinkel, Batu K.; Joo, Hwang-Soo; Park, Lawrence P.; George, Dennis; Thaden, Joshua T.; Messina, Julia A.; Maskarinec, Stacey A.; Mueller-Premru, Manica; Athan, Eugene; Tattevin, Pierre; Pericas, Juan M.; Woods, Christopher W.; Otto, Michael; Fowler, Vance G.

    2016-01-01

    Summary Background Phenol-soluble modulins (PSMs) are amphipathic, pro-inflammatory proteins secreted by most Staphylococcus aureus isolates. This study tested the hypothesis that in vitro PSM production levels are associated with specific clinical phenotypes. Methods 177 methicillin-resistant S. aureus (MRSA) isolates from infective endocarditis (IE), skin and soft tissue infection (SSTI), and hospital-acquired/ventilator-associated pneumonia (HAP) were matched by geographic origin, then genotyped using spa-typing. In vitro PSM production was measured by high performance liquid chromatography/mass spectrometry. Statistical analysis was performed using Chi-squared or Kruskal–Wallis tests as appropriate. Results Spa type 1 was significantly more common in SSTI isolates (62.7% SSTI; 1.7% IE; 16.9% HAP; p < 0.0001) while HAP and IE isolates were more commonly spa type 2 (0% SSTI; 37.3% IE; 40.7% HAP; p < 0.0001). USA300 isolates produced the highest levels of PSMs in vitro. SSTI isolates produced significantly higher quantities of PSMα1-4, PSMβ1, and δ-toxin than other isolates (p < 0.001). These findings persisted when USA300 isolates were excluded from analysis. PMID:26079275

  2. A glutamic acid-producing lactic acid bacteria isolated from Malaysian fermented foods.

    PubMed

    Zareian, Mohsen; Ebrahimpour, Afshin; Bakar, Fatimah Abu; Mohamed, Abdul Karim Sabo; Forghani, Bita; Ab-Kadir, Mohd Safuan B; Saari, Nazamid

    2012-01-01

    l-glutamaic acid is the principal excitatory neurotransmitter in the brain and an important intermediate in metabolism. In the present study, lactic acid bacteria (218) were isolated from six different fermented foods as potent sources of glutamic acid producers. The presumptive bacteria were tested for their ability to synthesize glutamic acid. Out of the 35 strains showing this capability, strain MNZ was determined as the highest glutamic-acid producer. Identification tests including 16S rRNA gene sequencing and sugar assimilation ability identified the strain MNZ as Lactobacillus plantarum. The characteristics of this microorganism related to its glutamic acid-producing ability, growth rate, glucose consumption and pH profile were studied. Results revealed that glutamic acid was formed inside the cell and excreted into the extracellular medium. Glutamic acid production was found to be growth-associated and glucose significantly enhanced glutamic acid production (1.032 mmol/L) compared to other carbon sources. A concentration of 0.7% ammonium nitrate as a nitrogen source effectively enhanced glutamic acid production. To the best of our knowledge this is the first report of glutamic acid production by lactic acid bacteria. The results of this study can be further applied for developing functional foods enriched in glutamic acid and subsequently γ-amino butyric acid (GABA) as a bioactive compound.

  3. Screening and isolation of PHB-producing bacteria in a polluted marine microbial mat.

    PubMed

    López-Cortés, Alejandro; Lanz-Landázuri, Alberto; García-Maldonado, José Q

    2008-07-01

    The characteristics of microbial mats within the waste stream from a seafood cannery were compared to a microbial community at a pristine site near a sandy beach at Puerto San Carlos, Baja California Sur, Mexico. Isolation of poly-beta-hydroxybutyrate (PHB)-producing bacteria, recognition of brightly refractile cytoplasmatic inclusions, lipophilic stains with Sudan Black and Nile Red, and chemical extraction of PHB were used as a culture-dependent strategy for the detection of PHB-producing bacteria. The culture-independent approach included denaturing gradient gel electrophoresis of phylotypes of 16S rRNA of microbial communities from environmental samples. Significant differences in community structure were found among the polluted and pristine sites. These differences were correlated with the physicochemical characteristics of the seawater column. At the polluted site, the seawater was rich in nutrients (ammonia, phosphates, and organic matter), compared to the pristine location. Partial sequencing of 16S rDNA of cultures of bacteria producing PHB included Bacillus and Staphylococcus at both sites; Paracoccus and Micrococcus were found only at the polluted site and Rhodococcus and Methylobacterium were found only at the pristine site. Bands of the sequences of 16S rDNA from both field samples in the denaturing gradient gel electrophoresis (DGGE) analyses affiliated closely only with bacterial sequences of cultures of Bacillus and Staphylococcus. High concentrations of organic and inorganic nutrients at the polluted site had a clear effect on the composition and diversity of the microbial community compared to the unpolluted site.

  4. Isolation and characterization of siderophore producing antagonistic rhizobacteria against Rhizoctonia solani.

    PubMed

    Solanki, Manoj Kumar; Singh, Rajesh Kumar; Srivastava, Supriya; Kumar, Sudheer; Kashyap, Prem Lal; Srivastava, Alok K; Arora, Dilip K

    2014-06-01

    Plant protection through siderophore producing rhizobacteria (SPR) has emerged as a sustainable approach for crop health management. In present study, 220 bacteria isolated from tomato rhizosphere were screened for in vitro antagonistic activity against Rhizoctonia solani AG-4. Nine potent antagonistic strains viz., Alcaligenes sp. (MUN1, MB21, and MPF37), Enterobacter sp. (MPM1), Pseudomonas sp. (M10A and MB65), P. aeruginosa (MPF14 and MB123) and P. fluorescens (MPF47) were identified on the basis of physiological characters and 16S rDNA sequencing. These strains were able to produce hydrolytic enzymes, hydrogen cyanide, indole acetic acid, although, only few strains were able to solubilize phosphate. Two strains (MB123 and MPF47) showed significant disease reduction in glasshouse conditions were further evaluated under field conditions using three different application methods. Application of P. fluorescens (MPF47) in nursery as soil mix + seedling root treatments prior to transplantation resulted in significant disease reduction compared to control. Total chlorophyll and available iron were significantly higher in the MPF47 treated plants in contrast to infected control. In conclusion, siderophore producing bacteria MPF47 have strong biocontrol abilities and its application as soil mix + seedling root treatments provided strong shield to plant roots against R. solani and could be used for effective bio-management of pathogen.

  5. CTX-M-14 β-lactamase-producing Citrobacter freundii isolated in Venezuela.

    PubMed

    Millán, Beatriz; Ghiglione, Bárbara; Díaz, Tulia; Gutkind, Gabriel; Araque, María

    2011-05-31

    A clinical isolate of C. freundii with reduced susceptibility to extended-spectrum β-lactams from a woman with cystocele associated with recurrent urinary tract infection was analyzed. Susceptibility tests, double disk synergy tests (DDST) and enzymatic activity by the agar iodometric method suggested the presence of ESBLs. Conjugation experiments revealed the presence of a large conjugative plasmid (pLM07/20) with an exclusive FrepB replicon type (IncF/FIB). PCR analysis and sequencing confirmed the presence of the blaCTX-M-14 gene in the pLM07/20 from C. freundii.LM07/10. Although this is the first report of CTX-M-14 in Venezuela, we alert the medical community that future increase of these β-lactamases in our city could be due to dissemination of plasmids into bacterial populations.

  6. CTX-M-14 β-lactamase-producing Citrobacter freundii isolated in Venezuela

    PubMed Central

    2011-01-01

    A clinical isolate of C. freundii with reduced susceptibility to extended-spectrum β-lactams from a woman with cystocele associated with recurrent urinary tract infection was analyzed. Susceptibility tests, double disk synergy tests (DDST) and enzymatic activity by the agar iodometric method suggested the presence of ESBLs. Conjugation experiments revealed the presence of a large conjugative plasmid (pLM07/20) with an exclusive FrepB replicon type (IncF/FIB). PCR analysis and sequencing confirmed the presence of the blaCTX-M-14 gene in the pLM07/20 from C. freundii.LM07/10. Although this is the first report of CTX-M-14 in Venezuela, we alert the medical community that future increase of these β-lactamases in our city could be due to dissemination of plasmids into bacterial populations. PMID:21627834

  7. Identification of penicillinase producing Neisseria gonorrhoeae in Chile during clinical and microbiological study of gonococcal susceptibility to antimicrobial agents.

    PubMed Central

    Garcia Moreno, J; Dillon, J R; Arroyave, R; Maldonado, A; Fich, F; Salvo, A; Villalobos, D; Vincent, P; Pauze, M

    1987-01-01

    The first penicillinase producing isolates of Neisseria gonorrhoeae (PPNG) identified in Chile were discovered during a clinical and microbiological study to compare the efficacy of penicillin (4.8 MIU aqueous procaine penicillin G plus 1 g oral probenecid) and tetracycline (1.5 g followed by 500 mg four times daily for four days) treatment regimens for acute uncomplicated gonorrhoea. Penicillin treatment was effective in 93.1% (282) of 303 patients, whereas tetracycline was effective in 98.3% (233) of 237 patients. Six of the penicillin treatment failures were attributable to PPNG strains. In all, 21 PPNG strains were identified during the study. They were genetically identical, having a wild type auxotype, a WII/III serotype (serovar Bajk), and carrying cryptic and transfer plasmids and an Asian type penicillinase producing plasmid. In addition, 674 non-PPNG isolates were tested for their susceptibility to eight antimicrobials. Over 95% were sensitivie to 1 mg/l of penicillin, ampicillin, cefotaxime, cefuroxime, and erythromycin, over 90% were sensitive to 1 mg/l of tetracycline and 2 mg/l of thiamphenicol, and all were sensitive to spectinomycin. Of 226 non-PPNG isolates characterised for plasmid content and auxotype, 90% (205) were either wild type or proline requiring, 67% (153) carried only the cryptic plasmid, and a further 31% (71) carried both cryptic and transfer plasmids. Unusually, three of four isolates lacking the cryptic plasmid carried only the transfer plasmid. Images PMID:3102348

  8. Toxin Profile, Biofilm Formation, and Molecular Characterization of Emetic Toxin-Producing Bacillus cereus Group Isolates from Human Stools.

    PubMed

    Oh, Su Kyung; Chang, Hyun-Joo; Choi, Sung-Wook; Ok, Gyeongsik; Lee, Nari

    2015-11-01

    Emetic toxin-producing Bacillus cereus group species are an important problem, because the staple food for Korean is grains such as rice. In this study, we determined the prevalence (24 of 129 isolates) of emetic B. cereus in 36,745 stool samples from sporadic food-poisoning cases in Korea between 2007 and 2008. The toxin gene profile, toxin production, and biofilm-forming ability of the emetic B. cereus isolates were investigated. Repetitive element sequence polymorphism polymerase chain reaction fingerprints (rep-PCR) were also used to assess the intraspecific biodiversity of these isolates. Emetic B. cereus was present in 0.07% of the sporadic food-poisoning cases. The 24 emetic isolates identified all carried the nheABC and entFM genes and produced NHE enterotoxin. However, they did not have hemolysin BL toxin or related genes. A relationship between biofilm formation and toxin production was not observed in this study. The rep-PCR fingerprints of the B. cereus isolates were not influenced by the presence of toxin genes, or biofilm-forming ability. The rep-PCR assay discriminated emetic B. cereus isolates from nonemetic isolates, even if this assay did not perfectly discriminate these isolates. Further study on emetic isolates possessing a high degree of diversity may be necessary to evaluate the performance of the subtyping assay to discriminate emetic and nonemetic B. cereus isolates and could provide a more accurate indication of the risk from B. cereus strains.

  9. Characterization of Novel Cellulase-producing Bacteria Isolated From Rotting Wood Samples.

    PubMed

    Paudel, Yagya Prasad; Qin, Wensheng

    2015-11-01

    Seventeen bacterial isolates were screened for their cellulase activity by carboxymethyl cellulose (CMC) plate assay. The bacterial strain K1 showed the largest depolymerized region in CMC plate assay and was further studied for quantitative cellulase activity. On the basis of 16S rDNA sequence analysis, the strain K1 was found to be Bacillus sp. This strain produced the maximum CMCase at pH 6 and 50 °C in the presence of peptone (1%) as a source of nitrogen. The CMCase activity was stimulated by Ca(2+) (2 mM) by 20% over the control. The CMCase activity of this Bacillus sp. K1 was highly induced when lactose was used as a source of carbon during fermentation.

  10. Distribution and mycotoxin-producing ability of some fungal isolates from the air

    NASA Astrophysics Data System (ADS)

    Cvetnić, Zdenka; Pepeljnjak, S.

    Research was carried out on presence and prevalence of common fungal air spores at locations in Croatia. The sampling method employed in the study was by exposure 350 of Petri agar plates to the air for 10 min. Approximately 3400 colonies were found and mould spores belonging to 22 fungal genera were identified. Cladosporium (44.7%), Penicillium (34.4%), Alternaria (26.3%), Aspergillus (21.6%) and Absidia (12.2%) were the most prevalent fungi encountered. Investigation of toxigenic potential of airborne fungi isolates of genera Aspergillus, Fusarium and Trichoderma showed 16.9% mycotoxin-producing strains. The production of aflatoxin B 1 by A. flavus sterigmatocystin by A. versicolor zearalenon and T-2 toxin by F. graminearum and diacetoscirpenol by strains of T. viride were obtained.

  11. Predictors of disability worsening in clinically isolated syndrome

    PubMed Central

    Jokubaitis, Vilija G; Spelman, Tim; Kalincik, Tomas; Izquierdo, Guillermo; Grand'Maison, François; Duquette, Pierre; Girard, Marc; Lugaresi, Alessandra; Grammond, Pierre; Hupperts, Raymond; Cabrera-Gomez, José; Oreja-Guevara, Celia; Boz, Cavit; Giuliani, Giorgio; Fernández-Bolaños, Ricardo; Iuliano, Gerardo; Lechner-Scott, Jeannette; Verheul, Freek; van Pesch, Vincent; Petkovska-Boskova, Tatjana; Fiol, Marcela; Moore, Fraser; Cristiano, Edgardo; Alroughani, Raed; Bergamaschi, Roberto; Barnett, Michael; Slee, Mark; Vella, Norbert; Herbert, Joseph; Shaw, Cameron; Saladino, Maria Laura; Amato, Maria Pia; Liew, Danny; Paolicelli, Damiano; Butzkueven, Helmut; Trojano, Maria

    2015-01-01

    Objective To assess demographic, clinical, magnetic resonance imaging, and treatment exposure predictors of time to 3 or 12-month confirmed disability worsening in clinically isolated syndrome (CIS) and early multiple sclerosis (MS). Methods We utilized the MSBase Incident Study (MSBasis), a prospective cohort study of outcome after CIS. Predictors of time to first 3 and 12-month confirmed expanded disability status scale worsening were analyzed using Cox proportional hazards regression. Results About 1989 patients were analyzed, the largest seen-from-onset cohort reported to-date. A total of 391 patients had a first 3-month confirmed disability worsening event, of which 307 were sustained for 12 months. Older age at CIS onset (adjusted hazard ratio: aHR 1.17, 95% 1.06, 1.30), pyramidal (aHR 1.45, 95% CI 1.13, 1.89) and ambulation (HR 1.60, 95% CI 1.09, 2.34) system dysfunction, annualized relapse rate (aHR 1.20, 95% CI 1.18, 1.22), and lower proportion of observation time on treatment were associated with 3-month confirmed worsening. Predictors of time to 12-month sustained worsening included pyramidal system dysfunction (Hazard ratio: aHR 1.38, 95% CI 1.05, 1.83), and older age at CIS onset (aHR 1.17, 95% CI 1.04, 1.31). Greater proportion of follow-up time exposed to treatment was associated with greater reductions in the rate of worsening. Interpretation This study provides class IV evidence for a strong protective effect of disease-modifying treatment to reduce disability worsening events in patients with CIS and early MS, and confirms age and pyramidal dysfunction at onset as risk factors. PMID:26000321

  12. Genetic Dissection of an Exogenously Induced Biofilm in Laboratory and Clinical Isolates of E. coli

    PubMed Central

    Amini, Sasan; Goodarzi, Hani; Tavazoie, Saeed

    2009-01-01

    Microbial biofilms are a dominant feature of many human infections. However, developing effective strategies for controlling biofilms requires an understanding of the underlying biology well beyond what currently exists. Using a novel strategy, we have induced formation of a robust biofilm in Escherichia coli by utilizing an exogenous source of poly-N-acetylglucosamine (PNAG) polymer, a major virulence factor of many pathogens. Through microarray profiling of competitive selections, carried out in both transposon insertion and over-expression libraries, we have revealed the genetic basis of PNAG-based biofilm formation. Our observations reveal the dominance of electrostatic interactions between PNAG and surface structures such as lipopolysaccharides. We show that regulatory modulation of these surface structures has significant impact on biofilm formation behavior of the cell. Furthermore, the majority of clinical isolates which produced PNAG also showed the capacity to respond to the exogenously produced version of the polymer. PMID:19436718

  13. Saccharothrix sp. PAL54, a new chloramphenicol-producing strain isolated from a Saharan soil.

    PubMed

    Aouiche, Adel; Sabaou, Nasserdine; Meklat, Atika; Zitouni, Abdelghani; Bijani, Christian; Mathieu, Florence; Lebrihi, Ahmed

    2012-03-01

    An actinomycete strain designated PAL54, producing an antibacterial substance, was isolated from a Saharan soil in Ghardaïa, Algeria. Morphological and chemical studies indicated that this strain belonged to the genus Saccharothrix. Analysis of the 16S rDNA sequence showed a similarity level ranging between 96.9 and 99.2% within Saccharothrix species, with S. longispora DSM 43749(T), the most closely related. DNA-DNA hybridization confirmed that strain PAL54 belonged to Saccharothrix longispora. It showed very strong activity against pathogenic Gram-positive and Gram-negative bacteria responsible for nosocomial infections and resistant to multiple antibiotics. Strain PAL54 secreted the antibiotic optimally during mid-stationary and decline phases of growth. One antibacterial compound was isolated from the culture broth and purified by HPLC. The active compound was elucidated by uv-visible and NMR spectroscopy and by mass spectrometry. The results showed that this compound was a D: (-)-threo chloramphenicol. This is the first report of chloramphenicol production by a Saccharothrix species.

  14. Isolation, identification and characterization of Cystobasidium oligophagum JRC1: A cellulase and lipase producing oleaginous yeast.

    PubMed

    Vyas, Sachin; Chhabra, Meenu

    2016-10-15

    Oleaginous yeast closely related to Cystobasidium oligophagum was isolated from soil rich in cellulosic waste. The yeast was isolated based on its ability to accumulate intracellular lipid, grow on carboxymethylcellulose (CMC) and produce lipase. It could accumulate up to 39.44% lipid in a glucose medium (12.45±0.97g/l biomass production). It was able to grow and accumulate lipids (36.46%) in the medium containing CMC as the sole carbon source. The specific enzyme activities obtained for endoglucanase, exoglucanase, and β-glucosidase were 2.27, 1.26, and 0.98IU/mg respectively. The specific enzyme activities obtained for intracellular and extracellular lipase were 2.16 and 2.88IU/mg respectively. It could grow and accumulate lipids in substrates including glycerol (42.04%), starch (41.54%), xylose (36.24%), maltose (26.31%), fructose (24.29%), lactose (21.91%) and sucrose (21.72%). The lipid profile of the organism was suitable for obtaining biodiesel with desirable fuel properties.

  15. Isolation and characterization of two exopolysaccharides produced by Lactobacillus plantarum EP56.

    PubMed

    Tallon, Richard; Bressollier, Philippe; Urdaci, Maria C

    2003-12-01

    A Lactobacillus plantarum strain producing exopolysaccharides (EPSs) was isolated from corn silage. When this strain, named L. plantarum EP56, was grown on a chemically defined medium, two EPS fractions were isolated. The cell-bound EPS fraction (EPS-b) was composed of a single high-molecular-mass polymer of 8.5x10(5) Da containing glucose, galactose and N-acetylgalactosamine in a molar ratio of approximately 3:1:1 and traces of glycerol and phosphoglycerol. The released EPS fraction (EPS-r) was composed of the high-molecular-mass bound polysaccharide and a second polymer of 4x10(4) Da containing glucose, galactose and rhamnose in a molar ratio of 3:1:1 and traces of glycerol and phosphoglycerol. EPS-b and EPS-r contained phosphate which contributes to their negative net charge. Studies on polysaccharide production and location showed that both polymers were synthesized during the exponential growth phase and that the EPS-b polymer was progressively released into the culture medium during the stationary growth phase. Carbon source and temperature influenced EPS synthesis when L. plantarum EP56 was grown in a chemically defined medium. Lactose was the most efficient carbon source among the five tested (glucose, galactose, fructose, lactose and sucrose). EPS production was also increased when the incubation temperature is lowered.

  16. Force produced after stretch in sarcomeres and half-sarcomeres isolated from skeletal muscles

    NASA Astrophysics Data System (ADS)

    Minozzo, Fábio C.; Baroni, Bruno M.; Correa, José A.; Vaz, Marco A.; Rassier, Dilson E.

    2013-07-01

    The goal of this study was to evaluate if isolated sarcomeres and half-sarcomeres produce a long-lasting increase in force after a stretch is imposed during activation. Single and half-sarcomeres were isolated from myofibrils using micro-needles, which were also used for force measurements. After full force development, both preparations were stretched by different magnitudes. The sarcomere length (SL) or half-sarcomere length variations (HSL) were extracted by measuring the initial and final distances from the Z-line to the adjacent Z-line or to a region externally adjacent to the M-line of the sarcomere, respectively. Half-sarcomeres generated approximately the same amount of isometric force (29.0 +/- SD 15.5 nN.μm-2) as single sarcomeres (32.1 +/- SD 15.3 nN.μm-2) when activated. In both cases, the steady-state forces after stretch were higher than the forces during isometric contractions at similar conditions. The results suggest that stretch-induced force enhancement is partly caused by proteins within the half-sarcomere.

  17. Force produced after stretch in sarcomeres and half-sarcomeres isolated from skeletal muscles.

    PubMed

    Minozzo, Fábio C; Baroni, Bruno M; Correa, José A; Vaz, Marco A; Rassier, Dilson E

    2013-01-01

    The goal of this study was to evaluate if isolated sarcomeres and half-sarcomeres produce a long-lasting increase in force after a stretch is imposed during activation. Single and half-sarcomeres were isolated from myofibrils using micro-needles, which were also used for force measurements. After full force development, both preparations were stretched by different magnitudes. The sarcomere length (SL) or half-sarcomere length variations (HSL) were extracted by measuring the initial and final distances from the Z-line to the adjacent Z-line or to a region externally adjacent to the M-line of the sarcomere, respectively. Half-sarcomeres generated approximately the same amount of isometric force (29.0 ± SD 15.5 nN·μm(-2)) as single sarcomeres (32.1 ± SD 15.3 nN·μm(-2)) when activated. In both cases, the steady-state forces after stretch were higher than the forces during isometric contractions at similar conditions. The results suggest that stretch-induced force enhancement is partly caused by proteins within the half-sarcomere.

  18. A cellulolytic Hypocrea strain isolated from South American brave straw produces a modular xylanase.

    PubMed

    Cabero, Karen; Pozzo, Tania; Lidén, Gunnar; Karlsson, Eva Nordberg

    2012-07-15

    Cellulase-producing fungi from the Andean regions in Bolivia, an ecosystem characterized as an extreme arid highland, were studied. Thirty-two isolates were screened for presence of cellulase activity using carboxymethyl cellulose (CMC) as carbon source, and activity was confirmed using a filter paper assay. One isolate, denoted as BLT1C was selected from this screening, and sequence analysis of the internal transcribed spacer (ITS) classified the strain as Hypocrea lixii. The secretome of BLT1C showed high xylanase activity (compared to that of two reference Trichoderma reesei strains) when cultivated using brave straw, an abundant native grass from the area, as carbon source. SDS-PAGE analysis revealed three main protein-bands (18, 32 and 65 kDa) and in-gel digestion and mass spectrometry combined with activity analysis showed that these proteins were active xylanases with molecular masses corresponding to (I) a single glycoside hydrolase family 11 catalytic module (18 kDa), and (II, III) modular enzymes, with the GH11 catalytic domain connected to a module of unknown function (32 kDa) or putatively connected to a GH7 catalytic module (65 kDa). The N-terminal sequence of the 65 kDa xylanase did not show significant sequence similarities to deposited sequences. The collected data on xylanase activity, molecular mass, GH11-sequence conservation, combined with lack of sequence similarities in the N-terminus show that the 65 kDa band corresponds to a novel modular xylanase.

  19. Molecular characterization of a Xylanase-producing fungus isolated from fouled soil

    PubMed Central

    Sakthiselvan, Punniavan; Naveena, Balakrishnan; Partha, Nagarajan

    2014-01-01

    Xylanase (EC 3. 2. 1. 8), hydrolyzes xylo-oligosaccharides into D-xylose and required for complete hydrolysis of native cellulose and biomass conversion. It has broad range of applications in the pulp and paper, pharmaceutical and Agri-food industries. Fifty fungal species were isolated from the fouled soil around an oil refinery and screened for the production of xylanase enzyme by enrichment culture techniques. The isolated fungal strain was identified as Hypocrea lixii SS1 based on the results of biochemical tests and 18s rRNA sequencing. The phylogenetic tree was constructed using the MEGA 5 software. Further, Hypocrea lixii SS1 was tested for the ability to utilize the sunflower oil sludge (waste from the oil industry) as the sole carbon source for xylanase production. The growth characteristics of Hypocrea lixii SS1 were also studied and maximum growth was found on the 7th day of incubation. The fungus showed a remarkable xylanase production of 38.9 U/mL. Xylanase was purified using a combination of 0–50% NH4SO2 precipitation, DEAE-sepharose and Sephacryl S-200 chromatography. Single peak obtained in RP-HPLC confirms the purity of xylanase. Further the enzyme produced was affirmed as xylanase with its molecular weight (29 kDa) using SDS-PAGE. PMID:25763033

  20. Multidrug resistance and ESBL-producing Salmonella spp. isolated from broiler processing plants

    PubMed Central

    Ziech, Rosangela Estel; Lampugnani, Camila; Perin, Ana Paula; Sereno, Mallu Jagnow; Sfaciotte, Ricardo Antônio Pilegi; Viana, Cibeli; Soares, Vanessa Mendonça; de Almeida Nogueira Pinto, José Paes; dos Santos Bersot, Luciano

    2016-01-01

    The aim of this study was to investigate the occurrence of multidrug-resistant, extended spectrum beta-lactamase (ESBL) producing Salmonella spp. isolated from conveyor belts of broiler cutting rooms in Brazilian broiler processing plants. Ninety-eight strains of Salmonella spp. were analyzed. Multidrug resistance was determined by the disk diffusion test and the susceptibility of the isolated bacteria was evaluated against 18 antimicrobials from seven different classes. The double disk diffusion test was used to evaluate ESBL production. Of the 98 strains tested, 84 were multidrug resistant. The highest rates of resistance were against nalidixic acid (95%), tetracycline (91%), and the beta-lactams: ampicillin and cefachlor (45%), followed by streptomycin and gentamicin with 19% and 15% of strain resistance, respectively. By contrast, 97% of the strains were sensitive to chloramphenicol. 45% of the strains were positive for the presence of ESBL activity. In this study, high rates of multidrug resistance and ESBL production were observed in Salmonella spp. PMID:26887244

  1. Characterization of Staphylococcus caprae Clinical Isolates Involved in Human Bone and Joint Infections, Compared with Goat Mastitis Isolates.

    PubMed

    d'Ersu, J; Aubin, G G; Mercier, P; Nicollet, P; Bémer, P; Corvec, S

    2016-01-01

    Staphylococcus caprae is an emerging microorganism in human bone and joint infections (BJI). The aim of this study is to describe the features of S. caprae isolates involved in BJI (H for human) compared with those of isolates recovered in goat mastitis (A for animal). Fourteen isolates of each origin were included. Identifications were performed using a Vitek 2 GP ID card, tuf gene sequencing, and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) Vitek MS. Molecular typing was carried out using pulsed-field gel electrophoresis (PFGE) and DiversiLab technology. The crystal violet method was used to determine biofilm-forming ability. Virulence factors were searched by PCR. Vitek MS technology provides an accurate identification for the two types of isolates compared to that of gold-standard sequencing (sensitivity, 96.4%), whereas the Vitek 2 GP ID card was more effective for H isolates. Molecular typing methods revealed two distinct lineages corresponding to the origin despite few overlaps: H and A. In our experimental conditions, no significant difference was observed in biofilm production ability between H and A isolates. Nine isolates (5 H isolates and 4 A isolates) behaved as weak producers while one A isolate was a strong producer. Concerning virulence factors, the autolysin atlC and the serine aspartate adhesin (sdrZ) genes were detected in 24 isolates (86%), whereas the lipase gene was always detected, except in one H isolate (96%). The ica operon was present in 23 isolates (82%). Fibrinogen-binding (fbe) or collagen-binding (cna) genes were not detected by using primers designed for Staphylococcus aureus or Staphylococcus epidermidis, even in low stringency conditions. Although S. caprae probably remains underestimated in human infections, further studies are needed to better understand the evolution and the adaptation of this species to its host.

  2. Characterization of Staphylococcus caprae Clinical Isolates Involved in Human Bone and Joint Infections, Compared with Goat Mastitis Isolates

    PubMed Central

    d'Ersu, J.; Aubin, G. G.; Mercier, P.; Nicollet, P.; Bémer, P.

    2015-01-01

    Staphylococcus caprae is an emerging microorganism in human bone and joint infections (BJI). The aim of this study is to describe the features of S. caprae isolates involved in BJI (H for human) compared with those of isolates recovered in goat mastitis (A for animal). Fourteen isolates of each origin were included. Identifications were performed using a Vitek 2 GP ID card, tuf gene sequencing, and matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) Vitek MS. Molecular typing was carried out using pulsed-field gel electrophoresis (PFGE) and DiversiLab technology. The crystal violet method was used to determine biofilm-forming ability. Virulence factors were searched by PCR. Vitek MS technology provides an accurate identification for the two types of isolates compared to that of gold-standard sequencing (sensitivity, 96.4%), whereas the Vitek 2 GP ID card was more effective for H isolates. Molecular typing methods revealed two distinct lineages corresponding to the origin despite few overlaps: H and A. In our experimental conditions, no significant difference was observed in biofilm production ability between H and A isolates. Nine isolates (5 H isolates and 4 A isolates) behaved as weak producers while one A isolate was a strong producer. Concerning virulence factors, the autolysin atlC and the serine aspartate adhesin (sdrZ) genes were detected in 24 isolates (86%), whereas the lipase gene was always detected, except in one H isolate (96%). The ica operon was present in 23 isolates (82%). Fibrinogen-binding (fbe) or collagen-binding (cna) genes were not detected by using primers designed for Staphylococcus aureus or Staphylococcus epidermidis, even in low stringency conditions. Although S. caprae probably remains underestimated in human infections, further studies are needed to better understand the evolution and the adaptation of this species to its host. PMID:26511738

  3. Gluconacetobacter medellinensis sp. nov., cellulose- and non-cellulose-producing acetic acid bacteria isolated from vinegar.

    PubMed

    Castro, Cristina; Cleenwerck, Ilse; Trcek, Janja; Zuluaga, Robin; De Vos, Paul; Caro, Gloria; Aguirre, Ricardo; Putaux, Jean-Luc; Gañán, Piedad

    2013-03-01

    The phylogenetic position of a cellulose-producing acetic acid bacterium, strain ID13488, isolated from commercially available Colombian homemade fruit vinegar, was investigated. Analyses using nearly complete 16S rRNA gene sequences, nearly complete 16S-23S rRNA gene internal transcribed spacer (ITS) sequences, as well as concatenated partial sequences of the housekeeping genes dnaK, groEL and rpoB, allocated the micro-organism to the genus Gluconacetobacter, and more precisely to the Gluconacetobacter xylinus group. Moreover, the data suggested that the micro-organism belongs to a novel species in this genus, together with LMG 1693(T), a non-cellulose-producing strain isolated from vinegar by Kondo and previously classified as a strain of Gluconacetobacter xylinus. DNA-DNA hybridizations confirmed this finding, revealing a DNA-DNA relatedness value of 81 % between strains ID13488 and LMG 1693(T), and values <70 % between strain LMG 1693(T) and the type strains of the closest phylogenetic neighbours. Additionally, the classification of strains ID13488 and LMG 1693(T) into a single novel species was supported by amplified fragment length polymorphism (AFLP) and (GTG)5-PCR DNA fingerprinting data, as well as by phenotypic data. Strains ID13488 and LMG 1693(T) could be differentiated from closely related species of the genus Gluconacetobacter by their ability to produce 2- and 5-keto-d-gluconic acid from d-glucose, their ability to produce acid from sucrose, but not from 1-propanol, and their ability to grow on 3 % ethanol in the absence of acetic acid and on ethanol, d-ribose, d-xylose, sucrose, sorbitol, d-mannitol and d-gluconate as carbon sources. The DNA G+C content of strains ID13488 and LMG 1693(T) was 58.0 and 60.7 mol%, respectively. The major ubiquinone of LMG 1693(T) was Q-10. Taken together these data indicate that strains ID13488 and LMG 1693(T) represent a novel species of the genus Gluconacetobacter for which the name Gluconacetobacter

  4. The characteristics of metallo-β-lactamase-producing gram-negative bacilli isolated from sputum and urine: a single center experience in Korea.

    PubMed

    Chin, Bum Sik; Han, Sang Hoon; Choi, Suk Hoon; Lee, Han Sung; Jeong, Su Jin; Choi, Hee Kyung; Choi, Jun Yong; Song, Young Goo; Kim, Chang Ki; Yong, Dongeun; Lee, Kyungwon; Kim, June Myung

    2011-03-01

    Metallo-β-lactamase (MBL) production usually results in high-level resistance to most β-lactams, and a rapid spread of MBL producing major gram-negative pathogens is a matter of particular concern worldwide. However, clinical data are scarce and most studies compared MBL producer (MP) with MBL non-producer (MNP) strains which included carbapenem susceptible isolates. Therefore, we collected clinical data of patients in whom imipenem-nonsusceptible Pseudomonas aeruginosa (PA) and Acinetobacter baumannii (AB) were isolated from sputum or urine, and investigated MBL production and the risk factors related with MBL acquisition. The antimicrobial susceptibility patterns were also compared between MPs and imipenem-nonsusceptible MNPs (INMNP). Among the 176 imipenem-nonsusceptible isolates, 12 MPs (6.8%) were identified. There was no identifiable risk factor that contributed to the acquisition of MPs when compared to INMNPs, and case-fatalities were not different between the two groups. The percentage of susceptible isolates was higher among MPs for piperacilin/tazobactam and fluoroquinolones while that of ceftazidime was higher in INMNPs (p < 0.05). As regards to aztreonam, which has been known to be a uniquely stable β-lactam against MBLs, susceptibility was preserved in only two isolates (16.7%) among MPs, and was not higher than that of INMNPs (23.2%). In conclusion, the contribution of MBLs to imipenem non-susceptibility in PA/ABs isolated from sputum and urine was relatively limited, and there was no significant risk factor associated with acquisition of MPs compared with INMNPs. However, limited susceptibility to aztreonam implies that MPs may hold additional resistance mechanisms, such as extended spectrum β-lactamases, AmpC β-lactamases, or other non-enzymatic mechanisms.

  5. Identification of Lactococcus-Specific Bacteriocins Produced by Lactococcal Isolates, and the Discovery of a Novel Bacteriocin, Lactococcin Z.

    PubMed

    Ishibashi, Naoki; Seto, Hiromi; Koga, Shoko; Zendo, Takeshi; Sonomoto, Kenji

    2015-09-01

    Lactic acid bacteria that produce Lactococcus-specific bacteriocins were isolated and identified as Lactococcus lactis from fresh corn or lettuce. Among them, four isolates were identified as lactococcin Q producers. Seven isolates showed antimicrobial activity against a lactococcin Q producer, L. lactis QU 4, as well as against nisin Z and lacticin Q producers belonging to L. lactis. Strain QU 7 was selected as a standard strain and showed no cross-immunity to lactococcin Q or other lactococcal bacteriocins. The bacteriocin produced by strain QU 7 was purified in three chromatographic steps, and its molecular mass was determined to be 5041.35 Da. The amino acid sequence analysis revealed that it is a novel class IId bacteriocin, referred to as lactococcin Z. It consisted of 45 amino acid residues. The lczA gene encoding the prepeptide of lactococcin Z showed homology to lactococcins A, B, and M. Thus, this report demonstrates a new example of Lactococcus-specific bacteriocins.

  6. DIFFERENTIAL EFFECTS OF OYSTER (CRASSOSTREA VIRGINICA) DEFENSES ON CLINICAL AND ENVIRONMENTAL ISOLATES OF VIBRIO PARAHEMOLYTICUS

    EPA Science Inventory

    Three clinical (2030, 2062, and 2107) and three environmental (1094, 1163, and ATCC 17802) isolates of Vibrio parahaemolyticus were exposed to hemocytes and plasma collected from oysters (Crassostrea virginica) to determine their susceptibility to putative oyster defenses. Clinic...

  7. Molecular characterisation of clinical Cryptococcus neoformans and Cryptococcus gattii isolates from Sichuan province, China.

    PubMed

    Wu, Si-Ying; Lei, Yao; Kang, Mei; Xiao, Yu-Ling; Chen, Zhi-Xing

    2015-05-01

    Previous reports on the molecular characteristics of clinical isolates of Cryptococcus species in China have focused on isolates from southeast China. To obtain a more detailed molecular epidemiology, a total of 92 cryptococcal isolates were collected from Sichuan province. A total of 24 isolates from 12 other provinces were collected for comparative study. Genotypes and mating types of 116 Cryptococcus isolates were determined. Among the 116 isolates, 43 isolates (19 isolates from Sichuan and 24 isolates outside of Sichuan) were analysed by multi-locus sequence typing (MLST). All 116 clinical isolates were mating type α. Most isolates (114/116) were molecular type VNI and the remaining two isolates were VGI and VGII respectively. MLST results revealed five sequence types (STs) of C. neoformans including two novel STs, with most isolates identified as ST5. The two C. gattii isolates identified in our study were ST44 and ST159. Based on our report and previous studies, there are 15 C. neoformans STs in China which can be divided into three subgroups. The C. gattii isolate from Sichuan could be a scattered subtype of VGII (ST44). Our findings demonstrated that C. neoformans isolates in Sichuan are genetically homogeneous, and ST5 is the epidemic clone of C. neoformans in China.

  8. Molecular characteristics of extended-spectrum β-lactamases in clinical isolates of Enterobacteriaceae from the Philippines.

    PubMed

    Kanamori, Hajime; Navarro, Rizalina B; Yano, Hisakazu; Sombrero, Lydia T; Capeding, Ma Rosario Z; Lupisan, Socorro P; Olveda, Remigio M; Arai, Kazuaki; Kunishima, Hiroyuki; Hirakata, Yoichi; Kaku, Mitsuo

    2011-01-01

    β-Lactamases, including extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases, are major resistance mechanisms of Enterobacteriaceae. Emergence of plasmid-mediated quinolone resistance (PMQR) determinants in ESBL-producing isolates poses a global threat. The molecular characterisitcs of ESBL and PMQR determinants in the Philippines are not well characterized. In this study, we investigated ESBLs and AmpC β-lactamases in clinical isolates of Enterobacteriaceae from the Philippines, and analyzed the association between ESBL and PMQR genes. A total of 91 amoxicilin non-susceptible Enterobacteriaceae were collected at the Research Institute for Tropical Medicine of the Philippines from 2006 to 2008. AmpC- or ESBL-producing isolates were screened by detecting a zone diameter for cefoxitin ≤ 14 mm or cefpodoxime ≤ 20 mm, respectively. Possible ESBL-producing strains were assessed by the ESBL confirmation test of the Clinical and Laboratory Standards Institute. PCR and sequencing were performed to detect the ESBL and PMQR genes. The number of ESBL-producers and AmpC-producers confirmed phenotypically was 17 (18.7%) and 61 (67.0%), respectively. Of 17 phenotypic ESBL-producers, 14 isolates had ESBL genes, including 6 of Escherichia coli, 3 of Enterobacter cloacae, 2 of Enterobacter aerogenes, 2 of Klebsiella pneumoniae, and 1 of Klebsiella ozaenae. Among these isolates, there were 13, 4, and 12 with bla(CTX-M), bla(SHV), and bla(TEM), respectively. Of the bla(CTX-M)-positive isolates, bla(CTX-M-15) shows the highest prevalence, followed by bla(CTX-M-3) and bla(CTX-M-14). Of 14 ESBL-producers identified by PCR, 4, 6, and 7 isolates were positive for qnrB, qnrS, and aac(6')-Ib-cr, respectively. The frequency of aac(6')-Ib-cr positivity was significantly higher among CTX-M-15-producing isolates. Thus, we identified bla(CTX-M), aac(6')-Ib-cr, and qnr in ESBL-producing Enterobacteriaceae from the Philippines, and revealed a significant association between bla

  9. Prevalence, microbiology, and clinical characteristics of extended-spectrum beta-lactamase-producing Enterobacter spp., Serratia marcescens, Citrobacter freundii, and Morganella morganii in Korea.

    PubMed

    Choi, S-H; Lee, J E; Park, S J; Kim, M-N; Choo, E J; Kwak, Y G; Jeong, J-Y; Woo, J H; Kim, N J; Kim, Y S

    2007-08-01

    We examined the prevalence and characteristics of extended-spectrum beta-lactamase (ESBL)-producing clinical isolates among Enterobacter spp., Serratia marcescens, Citrobacter freundii, and Morganella morganii, and evaluated screening criteria, clinical characteristics and outcomes of infections caused by ESBL-producing organisms. Between January and June 2005, a total of 493 nonduplicate consecutive isolates were collected at Asan Medical Center, a 2,300-bed tertiary hospital in Seoul, Republic of Korea. Fifty isolates (10.1%) were positive for phenotypical ESBL-test. The positive rate of phenotypical ESBL-test in Enterobacter spp., S. marcescens, C. freundii, and M. morganii was 12.8%, 12.4%, 4.9%, and 0% respectively. SHV-12 (18 isolates), CTX-M-9 (17 isolates), and TEM-52 (five isolates) were the most prevalent ESBL types. The ESBL in 17 strains could not be identified. As an ESBL screening criterion, the cefepime MIC >or=1 microg/ml had the highest sensitivity (0.84) and specificity (0.87). Half of the ESBL-producing isolates (25/50) were judged as pathogens. Cholangitis (ten cases), and pneumonia (six cases) were the most common infections. The overall mortality was 12.0%.

  10. Treatment and Clinical Outcomes of Urinary Tract Infections Caused by KPC-Producing Enterobacteriaceae in a Retrospective Cohort

    PubMed Central

    Alexander, Bryan T.; Marschall, Jonas; Tibbetts, Robert J.; Neuner, Elizabeth A.; Dunne, W. Michael; Ritchie, David J.

    2014-01-01

    Synopsis Background Optimal treatment regimens for infections caused by Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae are not well defined. Objectives This study describes the treatment and outcomes of patients with urinary tract infection (UTI) caused by KPC-producing Enterobacteriaceae. Methods Retrospective cohort study of adult inpatients with bacteriuria caused by KPC-positive organisms at Barnes-Jewish Hospital from June 1, 2006 to February 1, 2008. KPC-positive isolates were identified utilizing disk diffusion susceptibility testing and confirmed to contain blaKPC via molecular methods. Results Twenty-one patients met inclusion criteria and all were classified as having symptomatic UTI. The majority of patients were female (15 of 21 – 71%) with a mean age of 62.4 years (SD ± 15.2). Successful clinical and microbiologic responses were observed in 16 patients (76%) for both outcomes. Patients with urinary catheters had them removed or replaced in 9 of 15 cases (60%). Antibiotics active against the isolated pathogen were provided in 14 of 21 cases (67%), often after considerable delay (median: 72.5 hours, range: 4–312 hours). All seven patients receiving aminoglycoside therapy had successful clinical and microbiological responses, and in vitro testing of an extended antibiotic panel revealed high susceptibility rates for tigecycline (28 of 29 – 97%), minocycline (22 of 29 – 76%), and fosfomycin (25 of 29 – 86%) against the KPC-positive isolates. Conclusions Although delays to receipt of appropriate therapy were often experienced, clinical outcomes investigated revealed high rates of successful response in this limited group of patients. Therapy with aminoglycosides and tetracycline derivatives suggest therapeutic promise in the treatment of KPC-producing Enterobacteriaceae UTI. PMID:22691610

  11. Infections with VIM-1 Metallo-β-Lactamase-Producing Enterobacter cloacae and Their Correlation with Clinical Outcome▿

    PubMed Central

    Falcone, Marco; Mezzatesta, Maria Lina; Perilli, Mariagrazia; Forcella, Chiara; Giordano, Alessandra; Cafiso, Viviana; Amicosante, Gianfranco; Stefani, Stefania; Venditti, Mario

    2009-01-01

    The aim of this study was to ascertain the incidence and clinical significance of metallo-β-lactamases among Enterobacter strains isolated from patients with nosocomial infections. We prospectively collected data on patients with Enterobacter infection during a 13-month period. All of the strains were investigated for antibiotic susceptibility, the presence and expression of metallo-β-lactamases, and clonality. Of 29 infections (11 involving the urinary tract, 7 pneumonias, 3 skin/soft tissue infections, 3 intra-abdominal infections, 3 bacteremias, and 2 other infections), 7 (24%) were caused by Enterobacter cloacae strains harboring a blaVIM-1 gene associated or not with a blaSHV12 gene. Infections caused by VIM-1-producing strains were more frequently associated with a recent prior hospitalization (P = 0.006), cirrhosis (P = 0.03), relapse of infection (P < 0.001), and more prolonged duration of antibiotic therapy (P = 0.01) than were other infections. All of the isolates were susceptible to imipenem and meropenem and had blaVIM-1 preceded by a weak P1 promoter and inactivated P2 promoters. Most VIM-1-producing Enterobacter isolates belonged to a main clone, but four different clones were found. Multiclonal VIM-1-producing E. cloacae infections are difficult to diagnose due to an apparent susceptibility to various beta-lactams, including carbapenems, and are associated with a high relapse rate and a more prolonged duration of antibiotic therapy. PMID:19741074

  12. MRI criteria for MS in patients with clinically isolated syndromes.

    PubMed

    Montalban, X; Tintoré, M; Swanton, J; Barkhof, F; Fazekas, F; Filippi, M; Frederiksen, J; Kappos, L; Palace, J; Polman, C; Rovaris, M; de Stefano, N; Thompson, A; Yousry, T; Rovira, A; Miller, D H

    2010-02-02

    In recent years, criteria for the diagnosis of multiple sclerosis (MS) have changed, mainly due to the incorporation of new MRI criteria. While the new criteria are a logical step forward, they are complex and-not surprisingly-a good working knowledge of them is not always evident among neurologists and neuroradiologists. In some circumstances, several MRI examinations are needed to achieve an accurate and prompt diagnosis. This provides an incentive for continued efforts to refine the incorporation of MRI-derived information into the diagnostic workup of patients presenting with a clinically isolated syndrome. Within the European multicenter collaborative research network that studies MRI in MS (MAGNIMS), a workshop was held in London in November 2007 to review information that may simplify the existing MS diagnostic criteria, while maintaining a high specificity that is essential to minimize false positive diagnoses. New data that are now published were reviewed and discussed and together with a new proposal are integrated in this position paper.

  13. Isolation of an NDM-5-producing ST16 Klebsiella pneumoniae from a Dutch patient without travel history abroad, August 2015.

    PubMed

    Bathoorn, Erik; Rossen, John W; Lokate, Mariëtte; Friedrich, Alexander W; Hammerum, Anette M

    2015-01-01

    A New Delhi Metallo-beta-lactamase-5 (NDM-5)-producing ST16 Klebsiella pneumoniae strain was isolated from a Dutch patient in a long-term care facility without recent travel history abroad. Core genome multilocus sequence typing (cgMLST) revealed that the Dutch isolate was clonally related to isolates detected in four patients in Denmark in 2014. Public health experts and clinicians need to be informed; repetitive screening may be needed in patients without known risk factors for carbapenemases-producing Enterobacteriaceae who have undergone antibiotic treatment.

  14. Antilisterial Activity of Nisin-Like Bacteriocin-Producing Lactococcus lactis subsp. lactis Isolated from Traditional Sardinian Dairy Products

    PubMed Central

    Cosentino, Sofia; Fadda, Maria Elisabetta; Deplano, Maura; Melis, Roberta; Pomata, Rita; Pisano, Maria Barbara

    2012-01-01

    With the aim of selecting LAB strains with antilisterial activity to be used as protective cultures to enhance the safety of dairy products, the antimicrobial properties of 117 Lactococcus lactis subsp. lactis isolated from artisanal Sardinian dairy products were evaluated, and six strains were found to produce bacteriocin-like substances. The capacity of these strains to antagonize Listeria monocytogenes during cocultivation in skimmed milk was evaluated, showing a reduction of L. monocytogenes counts of approximately 4 log units compared to the positive control after 24 h of incubation. In order for a strain to be used as bioprotective culture, it should be carefully evaluated for the presence of virulence factors, to determine what potential risks might be involved in its use. None of the strains tested was found to produce biogenic amines or to possess haemolytic activity. In addition, all strains were sensitive to clinically important antibiotics such as ampicillin, tetracycline, and vancomycin. Our results suggest that these bac+ strains could be potentially applied in cheese manufacturing to control the growth of L. monocytogenes. PMID:22536018

  15. Detection and isolation of Shiga toxin-producing Escherichia coli (STEC) O104 from sprouts.

    PubMed

    Baranzoni, Gian Marco; Fratamico, Pina M; Rubio, Fernando; Glaze, Thomas; Bagi, Lori K; Albonetti, Sabrina

    2014-03-03

    Shiga toxin-producing Escherichia coli (STEC) strains belonging to serogroup O104 have been associated with sporadic cases of illness and have caused outbreaks associated with milk and sprouts. An outbreak that occurred in Europe in 2011 linked to fenugreek sprouts was caused by E. coli O104:H4 that had characteristics of an enteroaggregative E. coli (EAEC) but carried the gene that encoded for Shiga toxin 2. In this study, methods were developed for detection of this enteroaggregative STEC O104, as well as STEC O104 in sprouts. Multiplex PCR assays for enteroaggregative STEC O104:H4 targeted the stx2, aggR, and wzx104 genes, and for STEC O104 targeted the stx1-2, ehxA, and wzx104 genes. After incubating artificially contaminated sprouts at 4 °C for 48 h and overnight enrichment in modified buffered peptone water with pyruvate supplemented with three antibiotics (mBPWp), the pathogens were detected in all samples inoculated at a level of ca. 100CFU/25 g. Several samples inoculated at lower concentrations of ca. 10CFU/25 g were negative by the PCR assays, and this could have been due to cells not surviving or not being able to recover after the stress treatment at 4 °C for 48 h. For isolation of the pathogens, immunomagnetic separation (IMS) using magnetic beads coated with antibodies against O104 were employed, and this was followed by plating the beads onto mRBA and CHROMagar STEC O104 for isolation of E. coli O104:H4 and mRBA and CHROMagar STEC for isolation of E. coli O104:H7. Presumptive colonies were confirmed by agglutination using latex particles attached to antibodies against serogroup O104 and by the multiplex PCR assays. The methodologies described in this study for detection of enteroaggregative STEC O104:H4 and STEC O104 include the use of IMS and latex reagents for serogroup O104, and they enhance the ability to detect and isolate these pathogens from sprouts and potentially other foods, as well.

  16. Molecular Characterization of Extended-Spectrum β-Lactamase-Producer Klebsiella pneumoniae Isolates Causing Neonatal Sepsis in Peru.

    PubMed

    García, Coralith; Astocondor, Lizeth; Rojo-Bezares, Beatriz; Jacobs, Jan; Sáenz, Yolanda

    2016-02-01

    Klebsiella pneumoniae (KP) is the most common cause of neonatal sepsis in the low- and middle-income countries. Our objective was to describe the phenotypic and molecular characteristics of extended-spectrum β-lactamase (ESBL)-producer KP in neonatal care centers from Peru. We collected 176 non-duplicate consecutive KP isolates from blood isolates of neonates from eight general public hospitals of Lima, Peru. The overall rate of ESBL production was 73.3% (N = 129). The resistance rates were higher among ESBL-producer isolates when compared with the nonproducers: 85.3% versus 12.8% for gentamicin (P < 0.01), 59.7% versus 8.5% for trimethoprim-sulfamethoxazole (P < 0.01), 45.0% versus 8.5% for ciprofloxacin (P < 0.01), and 36.4% versus 12.8% for amikacin (P < 0.01). A total of 359 β-lactamase-encoding genes were detected among 129 ESBL-producer isolates; 109 isolates (84.5%) carried two or more genes. Among 37 ESBL-producer isolates randomly selected, CTX-M-15 and CTX-M-2 were the most common ESBLs detected. Most of the isolates (92%) belonged to the group KpI. Pulsed-field gel electrophoresis showed that multiple KP clones were circulating among the eight neonatal units included.

  17. Urban riverine environment is a source of multidrug-resistant and ESBL-producing clinically important Acinetobacter spp.

    PubMed

    Maravić, Ana; Skočibušić, Mirjana; Fredotović, Željana; Šamanić, Ivica; Cvjetan, Svjetlana; Knezović, Mia; Puizina, Jasna

    2016-02-01

    Some Acinetobacter species have emerged as very important opportunistic pathogens in humans. We investigated Acinetobacter spp. from the polluted urban riverine environment in Croatia in regard to species affiliation, antibiotic resistance pattern, and resistance mechanisms. Considerable number of isolates produced acquired extended-spectrum β-lactamase(s) (ESBLs), CTX-M-15 solely or with TEM-116. By Southern blot hybridization, bla TEM-116 was identified on plasmids ca. 10, 3, and 1.2 kb in Acinetobacter junii, A. gandensis, and A. johnsonii. The bla TEM-116-carrying plasmid in A. gandensis was successfully transferred by conjugation to azide-resistant Escherichia coli J53. A. radioresistens isolate also carried an intrinsic carbapenemase gene bla OXA-133 with ISAba1 insertion sequence present upstream to promote its expression. Majority of ESBL-producing isolates harbored integrases intI1 and/or intI2 and the sulfamethoxazole resistance gene sul1. Almost all isolates had overexpressed resistance-nodulation-cell division (RND) efflux system, indicating that this mechanism may have contributed to multidrug resistance phenotypes. This is the first report of environmental CTX-M-15-producing Acinetobacter spp. and the first identification of CTX-M-15 in A. johnsonii, A. junii, A. calcoaceticus, A. gandensis, A. haemolyticus, and A. radioresistens worldwide. We identified, also for the first time, the environmental Acinetobacter-producing TEM ESBLs, highlighting the potential risk for human health, and the role of these bacteria in maintenance and dissemination of clinically important antibiotic resistance genes in community through riverine environments.

  18. Inhibition of mycotoxin-producing fungi by Bacillus strains isolated from fish intestines.

    PubMed

    Veras, Flávio Fonseca; Correa, Ana Paula Folmer; Welke, Juliane Elisa; Brandelli, Adriano

    2016-12-05

    Bacillus strains isolated from the aquatic environment of the Brazilian Amazon region were tested for their activity against mycotoxigenic fungi. All tested bacteria showed antifungal activity, inhibiting at least 7 indicator fungi. Four Bacillus strains showing promising antifungal results were subsequently evaluated for their activity in reducing mycelial growth rate, sporulation, spore germination percentage, and mycotoxin production. Bacillus sp. P1 and Bacillus sp. P11 had a remarkable antifungal effect on toxigenic fungi. Washed bacterial cell suspension of strains P1 and P11 (10(7)CFU/ml) reduced by >70% the fungal colony diameters, including a complete inhibition of ochratoxin A (OTA) producing Aspergillus spp. Significant reduction of growth rate, sporulation and spore germination were also observed. The bacteria influenced the production of mycotoxins, causing a reduction around 99 and 97% in AFB1 and OTA concentration, respectively. Chromatographic analysis revealed the presence of lipopeptides (iturin A and surfactin isomers) in butanol extracts of cell-free supernatants and cell pellets of strains P1 and P11. Furthermore, antifungal activity of these extracts was confirmed against A. flavus A12 and A. carbonarius ITAL293, producers of AFB1 and OTA, respectively. These bacterial strains could be promising biocontrol agents against toxigenic fungi.

  19. Biological Activities of Tetrodotoxin-Producing Enterococcus faecium AD1 Isolated from Puffer Fishes.

    PubMed

    Nguyen, Tu Hoang Khue; Nguyen, Huu Ngoc; Nghe, Dat Van; Nguyen, Kim Hoang

    2015-01-01

    Puffer fishes were collected from the central sea in Vietnam from spring to summer season. The eggs were incubated in MRS broth that was used to test the toxicity in mice and isolate the lactic acid bacteria community that could produce tetrodotoxin (TTX). Thin layer chromatography (TLC) and high performance lipid chromatography (HPLC) were used to detect and quantify TTX. As a result, Enterococcus faecium AD1 which was identified by biochemical test and 16S rRNA analysis could produce TTX 0.3 mg/mL when cultured in MRS broth. The bacterium was optimized for TTX production and gave 0.18 mg/mL, 0.07 mg/mL, and 0.15 mg/mL in media prepared from the meat-washing water of freshwater fishes (Pangasius bocourti, Oreochromis sp.) and sea fish (Auxis thazard), respectively, that are also hopeful to answer some poisoning cases related to eating fishes. Enterococcus faecium also showed the wide antimicrobial activities on yeast, Gram-negative and -positive bacteria. Extracted exopolysaccharide (EPS) that reacted with 2,2-diphenyl-1-picrylhydrazyl to give IC50 at 5 mg/mL equaled 11 mg/mL ascorbic acid which could show effects on Hela-6 and Hep G2 using sulforhodamine B test. Enterococcus faecium can be claimed as a promising source in tetrodotoxin and biological compounds.

  20. Biological Activities of Tetrodotoxin-Producing Enterococcus faecium AD1 Isolated from Puffer Fishes

    PubMed Central

    Nguyen, Tu Hoang Khue; Nguyen, Huu Ngoc; Nghe, Dat Van; Nguyen, Kim Hoang

    2015-01-01

    Puffer fishes were collected from the central sea in Vietnam from spring to summer season. The eggs were incubated in MRS broth that was used to test the toxicity in mice and isolate the lactic acid bacteria community that could produce tetrodotoxin (TTX). Thin layer chromatography (TLC) and high performance lipid chromatography (HPLC) were used to detect and quantify TTX. As a result, Enterococcus faecium AD1 which was identified by biochemical test and 16S rRNA analysis could produce TTX 0.3 mg/mL when cultured in MRS broth. The bacterium was optimized for TTX production and gave 0.18 mg/mL, 0.07 mg/mL, and 0.15 mg/mL in media prepared from the meat-washing water of freshwater fishes (Pangasius bocourti, Oreochromis sp.) and sea fish (Auxis thazard), respectively, that are also hopeful to answer some poisoning cases related to eating fishes. Enterococcus faecium also showed the wide antimicrobial activities on yeast, Gram-negative and -positive bacteria. Extracted exopolysaccharide (EPS) that reacted with 2,2-diphenyl-1-picrylhydrazyl to give IC50 at 5 mg/mL equaled 11 mg/mL ascorbic acid which could show effects on Hela-6 and Hep G2 using sulforhodamine B test. Enterococcus faecium can be claimed as a promising source in tetrodotoxin and biological compounds. PMID:26380310

  1. Nitrogen-fixing and cellulose-producing Gluconacetobacter kombuchae sp. nov., isolated from Kombucha tea.

    PubMed

    Dutta, Debasree; Gachhui, Ratan

    2007-02-01

    A few members of the family Acetobacteraceae are cellulose-producers, while only six members fix nitrogen. Bacterial strain RG3T, isolated from Kombucha tea, displays both of these characteristics. A high bootstrap value in the 16S rRNA gene sequence-based phylogenetic analysis supported the position of this strain within the genus Gluconacetobacter, with Gluconacetobacter hansenii LMG 1527T as its nearest neighbour (99.1 % sequence similarity). It could utilize ethanol, fructose, arabinose, glycerol, sorbitol and mannitol, but not galactose or xylose, as sole sources of carbon. Single amino acids such as L-alanine, L-cysteine and L-threonine served as carbon and nitrogen sources for growth of strain RG3T. Strain RG3T produced cellulose in both nitrogen-free broth and enriched medium. The ubiquinone present was Q-10 and the DNA base composition was 55.8 mol% G+C. It exhibited low values of 5.2-27.77 % DNA-DNA relatedness to the type strains of related gluconacetobacters, which placed it within a separate taxon, for which the name Gluconacetobacter kombuchae sp. nov. is proposed, with the type strain RG3T (=LMG 23726T=MTCC 6913T).

  2. Characterization of an exopolysaccharide produced by Lactobacillus plantarum YW11 isolated from Tibet Kefir.

    PubMed

    Wang, Ji; Zhao, Xiao; Tian, Zheng; Yang, Yawei; Yang, Zhennai

    2015-07-10

    An exopolysaccharide (EPS)-producing strain YW11 isolated from Tibet Kefir was identified as Lactobacillus plantarum, and the strain was shown to produce 90 mgL(-1) of EPS when grown in a semi-defined medium. The molecular mass of the EPS was 1.1 × 10(5)Da. The EPS was composed of glucose and galactose in a molar ratio of 2.71:1, with possible presence of N-acetylated sugar residues in the polysaccharide as confirmed by NMR spectroscopy. Rheological studies showed that the EPS had higher viscosity in skim milk, at lower temperature, or at acidic pH. The viscous nature of the EPS was confirmed by observation with scanning electron microscopy that demonstrated a highly branched and porous structure of the polysaccharide. The atomic force microscopy of the EPS further revealed presence of many spherical lumps, facilitating binding with water in aqueous solution. The EPS had a higher degradation temperature (287.7°C), suggesting high thermal stability of the EPS.

  3. Neurotoxicity of mycotoxins produced in vitro by Penicillium roqueforti isolated from maize and grass silage.

    PubMed

    Malekinejad, H; Aghazadeh-Attari, J; Rezabakhsh, A; Sattari, M; Ghasemsoltani-Momtaz, B

    2015-10-01

    Fungal growth in human foods and animal feeds causes profound damage indicating a general spoilage, nutritional losses, and the formation of mycotoxins. Thirty apparently contaminated maize and grass silage samples were analyzed for the presence of total fungi. Penicillium roqueforti were isolated from all (100%) moldy silage samples on general and selective culture media. Furthermore, P. roqueforti-positive samples culture media subjected to the toxin extraction and toxins of patulin, penicillic acid, mycophenolic acid, and roquefortin-C (ROQ-C) were identified by means of high-performance liquid chromatography method. Cytotoxicity of identified toxins was investigated on neuro-2a cells. Alamar blue reduction, neutral red uptake, and intracellular adenosine triphosphate (ATP) content assays indicated that patulin and ROQ-C exert the strongest and weakest toxicity, respectively. Reactive oxygen species (ROS) generation by the toxins-exposed cells was measured, and the results supported the mitochondrial and lysosomal dysfunction and ATP depletion in exposed cells. Our data suggest that P. roqueforti is the widely present mold in analyzed maize and grass silage samples, which is able to produce toxins that cause neurotoxicity. This finding may explain in part some neuronal disorders in animals, which are fed contaminated feedstuffs with mentioned fungus. Moreover, mitochondrial and lysosomal dysfunction, intracellular ATP depletion, and the excessive ROS generation were found as the mechanisms of cytotoxicity for P. roqueforti-produced toxins.

  4. Whole-Genome Sequences of 80 Environmental and Clinical Isolates of Burkholderia pseudomallei

    PubMed Central

    Baker, Anthony L.; Chain, Patrick S.; Currie, Bart J.; Daligault, Hajnalka E.; Davenport, Karen W.; Davis, Christopher B.; Inglis, Timothy J. J.; Kaestli, Mirjam; Koren, Sergey; Mayo, Mark; Merritt, Adam J.; Sarovich, Derek S.; Warner, Jeffrey

    2015-01-01

    Here, we present the draft genome sequences of 80 isolates of Burkholderia pseudomallei. The isolates represent clinical cases of melioidosis and environmental isolates from regions in Australia and Papua New Guinea where B. pseudomallei is endemic. The genomes provide further context for the diversity of the pathogen. PMID:25676747

  5. Whole-Genome Sequences of 80 Environmental and Clinical Isolates of Burkholderia pseudomallei.

    PubMed

    Johnson, Shannon L; Baker, Anthony L; Chain, Patrick S; Currie, Bart J; Daligault, Hajnalka E; Davenport, Karen W; Davis, Christopher B; Inglis, Timothy J J; Kaestli, Mirjam; Koren, Sergey; Mayo, Mark; Merritt, Adam J; Price, Erin P; Sarovich, Derek S; Warner, Jeffrey; Rosovitz, M J

    2015-02-12

    Here, we present the draft genome sequences of 80 isolates of Burkholderia pseudomallei. The isolates represent clinical cases of melioidosis and environmental isolates from regions in Australia and Papua New Guinea where B. pseudomallei is endemic. The genomes provide further context for the diversity of the pathogen.

  6. Evaluation of Vitek MS for rapid classification of clinical isolates belonging to Mycobacterium avium complex.

    PubMed

    Boyle, Daniel P; Zembower, Teresa R; Qi, Chao

    2015-01-01

    We evaluated the ability of the Vitek MS system to classify clinical pulmonary Mycobacterium avium complex isolates compared to multilocus sequence analysis. Vitek MS accurately identified 55% of the isolates as M. avium and 18% as M. intracellulare, but misidentified 24 (27%) Mycobacterium chimaera isolates as Mycobacterium intracellulare.

  7. Complete genome sequence of Agarivorans gilvus WH0801(T), an agarase-producing bacterium isolated from seaweed.

    PubMed

    Zhang, Pujuan; Rui, Junpeng; Du, Zongjun; Xue, Changhu; Li, Xiangzhen; Mao, Xiangzhao

    2016-02-10

    Agarivorans gilvus WH0801(T), an agarase-producing bacterium, was isolated from the surface of seaweed. Here, we present the complete genome sequence, which consists of one circular chromosome of 4,416,600 bp with a GC content of 45.9%. This genetic information will provide insight into biotechnological applications of producing agar for food and industry.

  8. Isolation of Shiga Toxin-Producing Escherichia coli from a South American Camelid (Lama guanicoe) with Diarrhea

    PubMed Central

    Mercado, E. C.; Rodríguez, S. M.; Elizondo, A. M.; Marcoppido, G.; Parreño, V.

    2004-01-01

    Shiga toxin-producing Escherichia coli belonging to serotype O26:H11 was isolated from a 2-month-old guanaco with severe watery diarrhea. E. coli colonies carried the stx1 and eae genes, showed localized adherence to HEp-2 cells, and produced enterohemolysin. A serological response to lipopolysaccharide O26 was observed at the onset of diarrhea. PMID:15472347

  9. Caloramator boliviensis sp. nov., a thermophilic, ethanol-producing bacterium isolated from a hot spring.

    PubMed

    Crespo, Carla; Pozzo, Tania; Karlsson, Eva Nordberg; Alvarez, Maria Teresa; Mattiasson, Bo

    2012-07-01

    A novel moderately thermophilic, anaerobic, ethanol-producing bacterial strain, 45B(T), was isolated from a mixed sediment water sample collected from a hot spring at Potosi, Bolivia. The cells were straight to slightly curved rods approximately 2.5 µm long and 0.5 µm wide. The strain was Gram-stain-variable, spore-forming and monotrichously flagellated. Growth of the strain was observed at 45-65 °C and pH 5.5-8.0, with optima of 60 °C and pH 6.5. The substrates utilized by strain 45B(T) were xylose, cellobiose, glucose, arabinose, sucrose, lactose, maltose, fructose, galactose, mannose, glycerol, xylan, carboxymethylcellulose and yeast extract. The main fermentation product from xylose and cellobiose was ethanol (0.70 and 0.45 g ethanol per gram of consumed sugar, respectively). Acetate, lactate, propionate, carbon dioxide and hydrogen were also produced in minor quantities. 1,3-Propanediol was produced when glycerol-containing medium was supplemented with yeast extract. The major cellular fatty acids were anteiso-C(15:0), C(16:0), iso-C(16:0), C(15:1), iso-C(14:0), C(13:0) and C(14:0). The polar lipids diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an aminoglycolipid and 15 other unidentified lipids were predominant. The DNA G+C content of strain 45B(T) was 32.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequence similarity revealed that strain 45B(T) is located within the Gram-type positive Bacillus-Clostridium branch of the phylogenetic tree. On the basis of morphological and physiological properties and phylogenetic analysis, strain 45B(T) represents a novel species, for which the name Caloramator boliviensis sp. nov. is proposed; the type strain is 45B(T) (=DSM 22065(T)=CCUG 57396(T)).

  10. Isolation of thermophilic L-lactic acid producing bacteria showing homo-fermentative manner under high aeration condition.

    PubMed

    Tongpim, Saowanit; Meidong, Ratchanu; Poudel, Pramod; Yoshino, Satoshi; Okugawa, Yuki; Tashiro, Yukihiro; Taniguchi, Masayuki; Sakai, Kenji

    2014-03-01

    By applying non-sterile open fermentation of food waste, various thermotolerant l-lactic acid-producing bacteria were isolated and identified. The predominant bacterial isolates showing higher accumulation of l-lactic acid belong to 3 groups of Bacillus coagulans, according to their 16S rRNA gene sequence similarities. B. coagulans strains M21 and M36 produced high amounts of l-lactic acid of high optical purity and lactic acid selectivity in model kitchen refuse medium and glucose-yeast extract-peptone medium. Other thermotolerant isolates resembling to Bacillus humi, B. ruris, B. subtilis, B. niacini and B. soli were also identified. These bacteria produced low amounts of l-lactic acid of more than 99% optical purity. All isolated strains showed the highest growth rate at temperatures around 55-60°C. They showed unique responses to various oxygen supply conditions. The majority of isolates produced l-lactic acid at a low overall oxygen transfer coefficient (KLa); however, acetic acid was produced instead of l-lactic acid at a high KLa. B. coagulans M21 was the only strain that produced high, consistent, and reproducible amounts of optically pure l-lactic acid (>99% optical purity) under high and low KLa conditions in a homo-fermentative manner.

  11. Molecular characterization of ESBL-producing Escherichia coli isolates from hospital- and community-acquired infections in NW Mexico.

    PubMed

    Miranda-Romero, Ana Laura; Silva-Sanchez, Jesus; Garza-Ramos, Ulises; Barrios, Humberto; Sánchez-Pérez, Alejandro; Reyna-Flores, Fernando

    2017-01-01

    We investigated the molecular characteristics of ESBL-producing E. coli (ESBL-PEc) isolates from two hospitals and community settings in Ciudad Obregon, Sonora, Mexico. Between 2011 and 2014, thirty-seven ESBL-PEc isolates were collected. The major encoded ESBL was the blaCTX-M-15 gene (97%); followed by 13.5% of the blaSHV-12 gene, and 5.5% encoded the blaTLA-1 gene. The PMQR gene aac(6´)-Ib-cr was detected in 97% of the isolates and the qnrB gene, in one isolate. The ESBL-PEc isolates corresponded to phylogenetic group B2, ST131. Our results highlight the dissemination of ESBL-PEc isolates in northwest Mexico (Ciudad Obregon, Sonora).

  12. Isolation and characterization of mutant strains of Bordetella bronchiseptica lacking dermonecrotic toxin-producing ability.

    PubMed Central

    Nagano, H; Nakai, T; Horiguchi, Y; Kume, K

    1988-01-01

    Mutant strains of Bordetella bronchiseptica, named B-42, B-76, B-84, and B-119, were obtained after serial passages of a parent strain, L3, on Bordet-Gengou agar plates containing 20% horse blood and 200 micrograms of nalidixic acid per ml (BGN-20 agar plates) at 42 degrees C. Mutant strains completely lacked dermonecrotic toxin-producing ability, and lethal activity of the strains for mice was apparently reduced compared with that of strain L3. Mutant strains were able to grow at 42 degrees C, and the strains were nalidixic acid resistant. The mutant strains showed domed (Dom+) colony morphology with smooth texture (Scs+) and no production of zone of hemolysis (Hly-), but the agglutinability of these strains to antiserum prepared with Dom+ Scs+ Hly+ organisms of strain L3 was the same as that of strain L3. When strain B-42 was inoculated intramuscularly or intranasally into guinea pigs, all the animals survived without manifesting clinical signs and produced a high-level of serum agglutination antibodies against strain L3. These inoculated animals were protected against intranasal challenge with strain L3. These properties of mutant strains are hereditarily stable after 50 subcultures on BGN-20 agar plates or 20 passages in mice. These data suggest that the mutant strains lacking dermonecrotic toxin-producing ability can be used as a live attenuated vaccine against swine atrophic rhinitis. PMID:3182989

  13. Identification of efflux-mediated multi-drug resistance in bacterial clinical isolates by two simple methods.

    PubMed

    Martins, Marta; Couto, Isabel; Viveiros, Miguel; Amaral, Leonard

    2010-01-01

    Two simple, instrument-free, user-friendly methods that can readily be implemented by a routine microbiology laboratory are described for the detection of multi-drug-resistant (MDR) isolates that overexpress efflux pump (EP) systems responsible for the MDR phenotype. The first method employs the universal EP substrate ethidium bromide (EB) at varying concentrations in agar-containing plates upon which the contents of an overnight culture are swabbed as spokes of a wheel. In this method, named the EB-agar cartwheel method, it is assumed that the smallest concentration of EB that produces fluorescence of the bacterial mass represents the highest concentration of EB that the bacteria can exclude. Consequently, as the efflux system(s) of a given MDR clinical bacterial isolate is overexpressed relative to that of a reference strain, the minimal concentration of EB producing fluorescence is significantly greater. A simple formula is provided which affords the ranking of MDR clinical isolates with respect to the degree of their efflux capacity. The second method, which can be used after the first one, determines whether the MDR phenotype is based upon an overexpressed efflux system. This method employs a 24-well microplate with separate wells containing or lacking an efflux pump inhibitor (EPI) and Kirby-Bauer discs that correspond to the antibiotics to which the MDR strain is resistant. After the wells are inoculated with the MDR clinical isolate, the plate is incubated overnight and each well is evaluated by eye for evidence of growth. Comparison of growth to the relevant control enables the observer to determine the following outcomes: no growth produced by the EPI-antibiotic combination (i.e., reversal of antibiotic resistance); reduced growth produced by the EPI-antibiotic combination; no difference in growth, i.e., EPI does not affect the resistance to the given antibiotic. If the first method showed that there was a significant difference between the minimum

  14. Antimicrobial resistance profiles of dairy and clinical isolates and type strains of enterococci.

    PubMed

    de Fátima Silva Lopes, Maria; Ribeiro, Tânia; Abrantes, Marta; Figueiredo Marques, José Joaquim; Tenreiro, Rogério; Crespo, Maria Teresa Barreto

    2005-08-25

    The susceptibility to 30 antimicrobial agents was determined by the disk diffusion method for a collection of 172 enterococcal strains, including 96 isolates from dairy sources, 50 isolates of human and veterinary origin, and 26 reference strains from 24 different enterococcal species. Results were analysed by hierarchic numerical methods to cluster strains and to group antimicrobials according to similarity profiles. Resistance to 17 of the 30 antimicrobials showed to be correlated, leading to four groups reflecting the mode of action: quinolones (ofloxacin, enrofloxacin, ciprofloxacin and norfloxacin); macrolides (erythromycin, spiramycin), phenicols (cloramphenicol) and tetracyclins (tetracycline, oxytetracyclin); aminoglycosides (gentamicin, kanamycin) and lincosamides (clindamycin); penicillins (amoxicillin, ampicillin, penicillin G, piperacillin) and carbapenems (imipenem). Overall, the genus Enterococcus behaved as resistant to lincomycin, colistin, polimixin B and, with a few exceptions in dairy isolates, to methicillin. In general, all isolates were susceptible to vancomycin, cloramphenicol and fusidic acid. Clusters containing only dairy isolates were susceptible to the majority of antimicrobials tested, as opposed to clusters constituted only by clinical enterococcal isolates. Among the clinical isolates, 62% were highly multiresistant. Low level gentamicin resistance was found to be associated with clinical enterococci. Among dairy isolates, those that clustered with clinical isolates were both resistant to gentamicin and identified as Enterococcus faecalis. Resistance to macrolides, quinolones, penicillins and imipenem was found to be associated also with clinical environments, mainly with multiresistant isolates, contrary to what is generally agreed as a characteristic of the genus. Veterinary clinical isolates were mainly grouped with the multiresistant clinical human isolates. The 26 reference enterococcal strains were distributed in clusters with

  15. Biochemical, serological, and virulence characterization of clinical and oyster Vibrio parahaemolyticus isolates.

    PubMed

    Jones, Jessica L; Lüdeke, Catharina H M; Bowers, John C; Garrett, Nancy; Fischer, Markus; Parsons, Michele B; Bopp, Cheryl A; DePaola, Angelo

    2012-07-01

    In this study, 77 clinical and 67 oyster Vibrio parahaemolyticus isolates from North America were examined for biochemical profiles, serotype, and the presence of potential virulence factors (tdh, trh, and type III secretion system [T3SS] genes). All isolates were positive for oxidase, indole, and glucose fermentation, consistent with previous reports. The isolates represented 35 different serotypes, 9 of which were shared by clinical and oyster isolates. Serotypes associated with pandemic strains (O1:KUT, O1:K25, O3:K6, and O4:K68) were observed for clinical isolates, and 7 (9%) oyster isolates belonged to serotype O1:KUT. Of the clinical isolates, 27% were negative for tdh and trh, while 45% contained both genes. Oyster isolates were preferentially selected for the presence of tdh and/or trh; 34% contained both genes, 42% had trh but not tdh, and 3% had tdh but not trh. All but 1 isolate (143/144) had at least three of the four T3SS1 genes examined. The isolates lacking both tdh and trh contained no T3SS2α or T3SS2β genes. All clinical isolates positive for tdh and negative for trh possessed all T3SS2α genes, and all isolates negative for tdh and positive for trh possessed all T3SS2β genes. The two oyster isolates containing tdh but not trh possessed all but the vopB2 gene of T3SS2α, as reported previously. In contrast to the findings of previous studies, all strains examined that were positive for both tdh and trh also carried T3SS2β genes. This report identifies the serotype as the most distinguishing feature between clinical and oyster isolates. Our findings raise concerns about the reliability of the tdh, trh, and T3SS genes as virulence markers and highlight the need for more-detailed pathogenicity investigations of V. parahaemolyticus.

  16. Detection of extended-spectrum beta-lactamases in clinical isolates of Enterobacter cloacae and Enterobacter aerogenes.

    PubMed

    Tzelepi, E; Giakkoupi, P; Sofianou, D; Loukova, V; Kemeroglou, A; Tsakris, A

    2000-02-01

    The aim of the present study was to investigate the frequency of extended-spectrum beta-lactamases (ESBLs) in a consecutive collection of clinical isolates of Enterobacter spp. The abilities of various screening methods to detect ESBLs in enterobacters were simultaneously tested. Among the 68 consecutive isolates (56 Enterobacter cloacae and 12 Enterobacter aerogenes isolates) that were analyzed for beta-lactamase content, 21 (25 and 58%, respectively) possessed transferable ESBLs with pIs of 8.2 and phenotypic characteristics of SHV-type enzymes, 8 (14.3%) of the E. cloacae isolates produced a previously nondescribed, clavulanate-susceptible ESBL that exhibited a pI of 6.9 and that conferred a ceftazidime resistance phenotype on Escherichia coli transconjugants, and 2 E. cloacae isolates produced both of these enzymes. Among the total of 31 isolates that were considered ESBL producers, the Vitek ESBL detection test was positive for 2 (6.5%) strains, and the conventional double-disk synergy test (DDST) with amoxicillin-clavulanate and with expanded-spectrum cephalosporins and aztreonam was positive for 5 (16%) strains. Modifications of the DDST consisting of closer application of the disks (at 20 instead of 30 mm), the use of cefepime, and the use of both modifications increased the sensitivity of this test to 71, 61, and 90%, respectively. Of the 37 isolates for which isoelectric focusing failed to determine ESBLs, the Vitek test was false positive for 1 isolate and the various forms of DDSTs were false-positive for 3 isolates.

  17. Enzymatic characterisation of clinical isolates of Cryptococcus neoformans, Cryptococcus gattii and other environmental Cryptococcus spp.

    PubMed

    Chan, M Y; Tay, S T

    2010-01-01

    This study compared the enzymatic activity of clinical isolates of Cryptococcus neoformans, Cryptococcus gattii, environmental isolates of C. neoformans and non-neoformans Cryptococcus. Most of the cryptococcal isolates investigated in this study exhibited proteinase and phospholipase activities. Laccase activity was detected from all the C. neoformans and C. gattii isolates, but not from the non-neoformans Cryptococcus isolates. There was no significant difference in the proteinase, phospholipase and laccase activities of C. neoformans and C. gattii. However, significant difference in the enzymatic activities of beta-glucuronidase, alpha-glucosidase, beta-glucosidase and N-acetyl-beta-glucosaminidase between C. neoformans and C. gattii isolates was observed in this study. Environmental isolates of C. neoformans exhibited similar enzymatic profiles as the clinical isolates of C. neoformans, except for lower proteinase and laccase activities.

  18. Mutant prevention concentrations of daptomycin for Enterococcus faecium clinical isolates.

    PubMed

    Sinel, Clara; Jaussaud, Clara; Auzou, Michel; Giard, Jean-Christophe; Cattoir, Vincent

    2016-10-01

    Owing to the emergence of vancomycin-resistant Enterococcus faecium, treatment of enterococcal infections has become challenging. Although spontaneous in vitro resistance frequencies are low, the emergence of resistance is increasingly reported during daptomycin therapy. The mutant selection window (MSW), comprised between the minimum inhibitory concentration (MIC) and the mutant prevention concentration (MPC), corresponds to the concentration range within which resistant mutants may be selected. Since no data are available for enterococci, the aim of this study was to determine MPCs and MSWs for 12 representative E. faecium clinical isolates. MICs and MPCs were determined by broth microdilution and agar dilution methods, respectively. A basic MSW-derived pharmacodynamic analysis was also performed using mean maximum plasma concentration (Cmax) values obtained with dosages from 4 to 12 mg/kg. MICs and MPCs of daptomycin ranged from 0.5 to 4 mg/L and from 2 to 32 mg/L, respectively, with no correlation between them. The wideness of MSWs ranged from 2× to 32× MIC. Mean plasma Cmax values of daptomycin were calculated from 55 to 174.5 mg/L when using a dosage from 4 to 12 mg/kg. All Cmax values were above the MPCs whatever the dosage. Taking into account the protein binding of daptomycin (ca. 90%), the unbound fraction Cmax was just within the MSW in 67-92% of strains at recommended dosages (4-6 mg/kg) and was above the MPC for the majority of strains only with the highest dosage (12 mg/kg). This study shows that free daptomycin Cmax values usually fell into MSWs when using lower dosages (<10 mg/kg).

  19. Oral Contraceptives and Multiple Sclerosis/Clinically Isolated Syndrome Susceptibility

    PubMed Central

    Hellwig, Kerstin; Chen, Lie H.; Stancyzk, Frank Z.; Langer-Gould, Annette M.

    2016-01-01

    Background The incidence of multiple sclerosis (MS) is rising in women. Objective To determine whether the use of combined oral contraceptives (COCs) are associated with MS risk and whether this varies by progestin content. Methods We conducted a nested case-control study of females ages 14–48 years with incident MS or clinically isolated syndrome (CIS) 2008–2011 from the membership of Kaiser Permanente Southern California. Controls were matched on age, race/ethnicity and membership characteristics. COC use up to ten years prior to symptom onset was obtained from the complete electronic health record. Results We identified 400 women with incident MS/CIS and 3904 matched controls. Forty- percent of cases and 32% of controls had used COCs prior to symptom onset. The use of COCs was associated with a slightly increased risk of MS/CIS (adjusted OR = 1.52, 95%CI = 1.21–1.91; p<0.001). This risk did not vary by duration of COC use. The association varied by progestin content being more pronounced for levenorgestrol (adjusted OR = 1.75, 95%CI = 1.29–2.37; p<0.001) than norethindrone (adjusted OR = 1.57, 95%CI = 1.16–2.12; p = 0.003) and absent for the newest progestin, drospirenone (p = 0.95). Conclusions Our findings should be interpreted cautiously. While the use of some combination oral contraceptives may contribute to the rising incidence of MS in women, an unmeasured confounder associated with the modern woman’s lifestyle is a more likely explanation for this weak association. PMID:26950301

  20. Isolation and identification of the microbiota of Danish farmhouse and industrially produced surface-ripened cheeses.

    PubMed

    Gori, Klaus; Ryssel, Mia; Arneborg, Nils; Jespersen, Lene

    2013-04-01

    For studying the microbiota of four Danish surface-ripened cheeses produced at three farmhouses and one industrial dairy, both a culture-dependent and culture-independent approach were used. After dereplication of the initial set of 433 isolates by (GTG)5-PCR fingerprinting, 217 bacterial and 25 yeast isolates were identified by sequencing of the 16S rRNA gene or the D1/D2 domain of the 26S rRNA gene, respectively. At the end of ripening, the cheese core microbiota of the farmhouse cheeses consisted of the mesophilic lactic acid bacteria (LAB) starter cultures Lactococcus lactis subsp. lactis and Leuconostoc mesenteorides as well as non-starter LAB including different Lactobacillus spp. The cheese from the industrial dairy was almost exclusively dominated by Lb. paracasei. The surface bacterial microbiota of all four cheeses were dominated by Corynebacterium spp. and/or Brachybacterium spp. Brevibacterium spp. was found to be subdominant compared to other bacteria on the farmhouse cheeses, and no Brevibacterium spp. was found on the cheese from the industrial dairy, even though B. linens was used as surface-ripening culture. Moreover, Gram-negative bacteria identified as Alcalignes faecalis and Proteus vulgaris were found on one of the farmhouse cheeses. The surface yeast microbiota consisted primarily of one dominating species for each cheese. For the farmhouse cheeses, the dominant yeast species were Yarrowia lipolytica, Geotrichum spp. and Debaryomyces hansenii, respectively, and for the cheese from the industrial dairy, D. hansenii was the dominant yeast species. Additionally, denaturing gradient gel electrophoresis (DGGE) analysis revealed that Streptococcus thermophilus was present in the farmhouse raw milk cheese analysed in this study. Furthermore, DGGE bands corresponding to Vagococcus carniphilus, Psychrobacter spp. and Lb. curvatus on the cheese surfaces indicated that these bacterial species may play a role in cheese ripening.

  1. 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

  2. Saccharomyces cerevisiae: Population Divergence and Resistance to Oxidative Stress in Clinical, Domesticated and Wild Isolates

    PubMed Central

    Diezmann, Stephanie; Dietrich, Fred S.

    2009-01-01

    Background Saccharomyces cerevisiae has been associated with human life for millennia in the brewery and bakery. Recently it has been recognized as an emerging opportunistic pathogen. To study the evolutionary history of S. cerevisiae, the origin of clinical isolates and the importance of a virulence-associated trait, population genetics and phenotypic assays have been applied to an ecologically diverse set of 103 strains isolated from clinics, breweries, vineyards, fruits, soil, commercial supplements and insect guts. Methodology/Principal Findings DNA sequence data from five nuclear DNA loci were analyzed for population structure and haplotype distribution. Additionally, all strains were tested for survival of oxidative stress, a trait associated with microbial pathogenicity. DNA sequence analyses identified three genetic subgroups within the recombining S. cerevisiae strains that are associated with ecology, geography and virulence. Shared alleles suggest that the clinical isolates contain genetic contribution from the fruit isolates. Clinical and fruit isolates exhibit high levels of recombination, unlike the genetically homogenous soil isolates in which no recombination was detected. However, clinical and soil isolates were more resistant to oxidative stress than any other population, suggesting a correlation between survival in oxidative stress and yeast pathogenicity. Conclusions/Significance Population genetic analyses of S. cerevisiae delineated three distinct groups, comprising primarily the (i) human-associated brewery and vineyard strains, (ii) clinical and fruit isolates (iii) and wild soil isolates from eastern U.S. The interactions between S. cerevisiae and humans potentiate yeast evolution and the development of genetically, ecologically and geographically divergent groups. PMID:19390633

  3. Extended-spectrum β-lactamase and carbapenemase production among burn and non-burn clinical isolates of Klebsiella pneumoniae

    PubMed Central

    Eftekhar, Fereshteh; Naseh, Ziaeldin

    2015-01-01

    Background and Objectives: Klebsiella pneumoniae is an opportunistic pathogen responsible for up to 10% of nosocomial infections. The emergence and spread of multidrug resistant K. pneumoniae, mostly due to the production of extended-spectrum β-lactamases (ESBL) and carbapenemases, is often responsible for antibiotic treatment failure of these infections. We compared the antibiotic resistance profiles, ESBL and carbapenemase production as well as presence of KPC-type genes in burn and non-burn clinical isolates of K. pneumoniae. Materials and Methods: Fifty five clinical isolates were collected from Shahid Motahari (25 burn isolates) and Shariati (30 non-burn isolates) hospitals between August 2011 to January 2012. Antibiotic susceptibility was determined to 12 antibiotics using disc diffusion. The phenotypic confirmatory test (PCT) was used to screen for ESBL production. Carbapenemase activity was measured by the modified Hodge test (MHT) and KPC-type carbapenemases were further sought by PCR using specific primers. Results: Both groups were highly resistant to cefotaxime and ceftazidime (>92%). Burn isolates were significantly more resistant to cefepime, amoxiclav, imipenem, meropenem, gentamicin and ciprofloxacin compared to the non-burn strains (p<0.05). No significant differences were observed in ESBL production between the two groups. Carbapenem resistance was only observed among the burn isolates (n=5, 9.1%). Five carbapenem-resistant isolates produced carbapenemases. However, none of the isolates harbored the KPC-type genes. Conclusion: Higher rates of drug resistance were observed in burn isolates of K. pneumoniae compared to the non-burn strains. Carbapenemase phenotype was only observed among the burn isolates but KPC-type gene was not detected. PMID:26668701

  4. 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

  5. Klebsiella pneumoniae strains producing extended-spectrum beta-lactamases in Spain: microbiological and clinical features.

    PubMed

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

    2011-03-01

    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.

  6. Physiological, morphological, and immunochemical parameters used for the characterization of clinical and environmental isolates of Acanthamoeba.

    PubMed

    Becker-Finco, A; Costa, A O; Silva, S K; Ramada, J S; Furst, C; Stinghen, A E; De Figueiredo, B C; De Moura, J; Alvarenga, L M

    2013-03-01

    The factors that characterize Acanthamoeba strains as harmless or potentially pathogenic have not been elucidated. Analysing the in vitro and in vivo parameters of Acanthamoeba samples, including heat tolerance at temperatures close to that of the human body, cytopathic effects, and their ability to cause infections in animals, has been proposed to identify their pathogenic potential. Another promising criterion for differentiating strains is the analysis of their biochemical and immunochemical properties. In this study, a comparative evaluation between clinical and environmental Acanthamoeba isolates was performed on the basis of physiological, morphological, and immunochemical criteria. Crude antigens were used to characterize the protein profiles by electrophoresis and immunize mice to produce polyclonal and monoclonal antibodies. The antibodies were characterized using ELISA, Western blotting, and immunofluorescence techniques. The results obtained with polyclonal antibodies suggest the presence of specific proteins for each studied isolate and co-reactive immunochemical profiles among conserved components. Ten monoclonal antibody clones were obtained; mAb3 recognized 3 out of 4 samples studied. The results of this study may help standardize criteria for identifying and characterizing Acanthamoeba strains. Taken together, our results support the view that a set of features may help differentiate Acanthamoeba species and isolates.

  7. In vitro antimicrobial activity of five essential oils on multidrug resistant Gram-negative clinical isolates

    PubMed Central

    Sakkas, Hercules; Gousia, Panagiota; Economou, Vangelis; Sakkas, Vassilios; Petsios, Stefanos; Papadopoulou, Chrissanthy

    2016-01-01

    Aim/Background: The emergence of drug-resistant pathogens has drawn attention on medicinal plants for potential antimicrobial properties. The objective of the present study was the investigation of the antimicrobial activity of five plant essential oils on multidrug resistant Gram-negative bacteria. Materials and Methods: Basil, chamomile blue, origanum, thyme, and tea tree oil were tested against clinical isolates of Acinetobacter baumannii (n = 6), Escherichia coli (n = 4), Klebsiella pneumoniae (n = 7), and Pseudomonas aeruginosa (n = 5) using the broth macrodilution method. Results: The tested essential oils produced variable antibacterial effect, while Chamomile blue oil demonstrated no antibacterial activity. Origanum, Thyme, and Basil oils were ineffective on P. aeruginosa isolates. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration values ranged from 0.12% to 1.50% (v/v) for tea tree oil, 0.25-4% (v/v) for origanum and thyme oil, 0.50% to >4% for basil oil and >4% for chamomile blue oil. Compared to literature data on reference strains, the reported MIC values were different by 2SD, denoting less successful antimicrobial activity against multidrug resistant isolates. Conclusions: The antimicrobial activities of the essential oils are influenced by the strain origin (wild, reference, drug sensitive, or resistant) and it should be taken into consideration whenever investigating the plants’ potential for developing new antimicrobials. PMID:27366345

  8. Low prevalence of rmpA and high tendency of rmpA mutation correspond to low virulence of extended spectrum β-lactamase-producing Klebsiella pneumoniae isolates.

    PubMed

    Yu, Wen-Liang; Lee, Mei-Feng; Tang, Hung-Jen; Chang, Ming-Chung; Chuang, Yin-Ching

    2015-01-01

    Invasive syndrome caused by Klebsiella pneumoniae (KP), including liver abscess, is mainly caused by community-acquired strains with characteristics of positive hypermucoviscosity (HV) phenotype and regulator of mucoid phenotype A (rmpA) and transcriptional activator (rmpA2) genes. Extended- spectrum β-lactamase-producing KP (ESBL-KP) is commonly nosocomial and rarely HV-positive. We aimed to explore the reasons of the rarer prevalence of HV phenotype, rmpA and rmpA2 as well as the virulence phenotype among the ESBL-KP isolates from clinical specimens than those non-ESBL isolates. The β-lactamase genes, rmpA, rmpA2 and genes for K capsule serotype of 440 KP isolates were analyzed. The virulence of the isolates was characterized by the mouse lethality experiments. The prevalence rates of HV phenotype (∼ 50% vs. < 10%) as well as rmpA and rmpA2 genes (∼ 50-60% vs. < 20-30%) were significantly higher in non-ESBL group than in the ESBL group (p < 0.0001). Expression of HV phenotype in the rmpA-positive KP isolates was significantly rarer in the ESBL group than in non-ESBL group (33.3% vs. 91.9%, p < 0.0001). The frameshift mutations of rmpA and/or rmpA2 corresponded to negative HV phenotype of KP isolates that harbored the rmpA and/or rmpA2, resulting in variable mouse lethality (LD50, ∼ 10(3) - >5 × 10(7) CFU). The mutation rates might significantly differ among KP isolates from various sources. Virulence was dependent on rmpA-related HV phenotype. In conclusion, ESBL-KP isolates were less hypermucoviscous and less virulent than non-ESBL KP isolates, mostly due to concurrently lower carriage and higher mutation rates of the rmpA and rmpA2 genes.

  9. Low prevalence of STEC autotransporter contributing to biofilm formation (Sab) in verocytotoxin-producing Escherichia coli isolates of humans and raw meats.

    PubMed

    Buvens, G; Piérard, D

    2012-07-01

    Escherichia coli autotransporters (AT) are known to confer adherence to eukaryotic extracellular matrix and may, therefore, be virulence-associated. Recently, the plasmid-borne STEC AT contributing to biofilm formation (Sab) was described in verocytotoxin (VT)-producing E. coli (VTEC) strains that do not carry the locus of enterocyte effacement (LEE). Using polymerase chain reaction (PCR), we investigated the prevalence of sab and other virulence genes, VT1 (vtx1), VT2 (vtx2), intimin (eae), enterohemolysin (ehxA), STEC autoagglutinating adhesin (saa), and subtilase cytotoxin (subA), in VTEC isolates from patients (n=263) and raw meats of ruminants and wildlife (n=104) in Belgium from 1990 to 2010. Overall, sab was detected in three (0.82%) of 367 VTEC strains comprising human isolates of serotypes O162:H28 (no clinical data available) and OX183:H18 (patient with abdominal pain), and one ground beef O181:H16 isolate. These three sab-positive isolates were eae-negative, but ehxA-, saa-, and subA-positive. Our data show that sab is uncommon in VTEC isolates. All sab-positive VTEC strains identified to date carried a comparable plasmid-bound virulence profile (ehxA-saa-subA-sab), which may be transmitted to other strains. Sab may mediate intestinal adherence in some LEE-negative VTEC isolates, but more studies on its prevalence and function are needed.

  10. Patient experience of source isolation: lessons for clinical practice.

    PubMed

    Barratt, Ruth Linda; Shaban, Ramon; Moyle, Wendy

    2011-10-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is now the leading antimicrobial-resistant organism of concern to clinicians worldwide. Preventing and controlling the increase and spread of MRSA within the health-care environment is therefore an important function of the infection control team. The prevention and control of MRSA requires strict use of both Standard and Additional Precautions, which include good hand hygiene practices, judicious antimicrobial prescribing, and source isolation. While few would dispute the need for these precautions for preventing the spread of MRSA and other infections, their use may result in adverse physical and psychological effects for the patient. In an age of quality and safety of health care, ensuring infection control practice such as source isolation and contact precautions adhere to fundamental human rights is paramount. This paper presents a review of the literature on the patient experience of source isolation for MRSA or other infectious diseases. The review yielded five major interconnected themes: (1) psychological effects of isolation; (2) coping with isolation; (3) social isolation; (4) communication and information provision; and (5) physical environment and quality of care. It found that the experience of isolation by patients has both negative and positive elements. Isolation may result in detrimental psychological effects including anxiety, stress and depression, but may also result in the patient receiving less or substandard care. However, patients may also benefit from the quietness and privacy of single rooms. Nurses and other healthcare workers must look for ways to improve the experience of isolation and contact precautions of patients in source isolation. Opportunities exist in particular in improving the environment and the patient's self-control of the situation and in providing adequate information.

  11. Thanatin activity on multidrug resistant clinical isolates of Enterobacter aerogenes and Klebsiella pneumoniae.

    PubMed

    Pagès, Jean-Marie; Dimarcq, Jean-Luc; Quenin, Solange; Hetru, Charles

    2003-09-01

    Efflux pumps protect bacterial cells by ejecting intracellular toxic molecules such as antibiotics, detergents and defensins that have penetrated the cell envelope. Some of these efflux pumps recognise structurally unrelated compounds (mdr pump) and account for the resistance of some organisms to two or more agents. It would be of interest to identify molecules that are able to circumvent the problems created by multidrug resistance phenotypes during antibiotic therapy. We have studied the activity of thanatin, a 21-residue cationic antimicrobial peptide produced by an insect, against three bacterial species. The antibacterial effect depended on the size of lipopolysaccharide side chains. In clinically resistant isolates of Enterobacter aerogenes and Klebsiella pneumoniae, the biological activity of thanatin is independent of the membrane permeability, possibly controlled by one or more porins, and/or the expression of drug efflux pumps, two mechanisms which confer high level antibiotic resistance. In addition, thanatin was able to improve the activity of structurally unrelated antibiotics (norfloxacin, chloramphenicol, tetracycline) on a multidrug- resistant E. aerogenes clinical isolate.

  12. Antitubercular and antibacterial activity of quinonoid natural products against multi-drug resistant clinical isolates.

    PubMed

    Dey, Diganta; Ray, Ratnamala; Hazra, Banasri

    2014-07-01

    Multi-drug resistant Mycobacterium tuberculosis and other bacterial pathogens represent a major threat to human health. In view of the critical need to augment the current drug regime, we have investigated therapeutic potential of five quinonoids, viz. emodin, diospyrin, plumbagin, menadione and thymoquinone, derived from natural products. The antimicrobial activity of quinonoids was evaluated against a broad panel of multi-drug and extensively drug-resistant tuberculosis (M/XDR-TB) strains, rapid growing mycobacteria and other bacterial isolates, some of which were producers of β-lactamase, Extended-spectrum β-lactamase (ESBL), AmpC β-lactamase, metallo-beta-lactamase (MBL) enzymes, as well as their drug-sensitive ATCC counterparts. All the tested quinones exhibited antimycobacterial and broad spectrum antibacterial activity, particularly against M. tuberculosis (lowest MIC 0.25 µg/mL) and Gram-positive bacteria (lowest MIC <4 µg/mL) of clinical origin. The order of antitubercular activity of the tested quinonoids was plumbagin > emodin ~ menadione ~ thymoquinone > diospyrin, whereas their antibacterial efficacy was plumbagin > menadione ~ thymoquinone > diospyrin > emodin. Furthermore, this is the first evaluation performed on these quinonoids against a broad panel of drug-resistant and drug-sensitive clinical isolates, to the best of our knowledge.

  13. Pseudomonas sp. BUP6, a novel isolate from Malabari goat produces an efficient rhamnolipid type biosurfactant.

    PubMed

    Priji, Prakasan; Sajith, Sreedharan; Unni, Kizhakkepowathial Nair; Anderson, Robin C; Benjamin, Sailas

    2017-01-01

    This study describes the characteristics of a biosurfactant produced by Pseudomonas sp. BUP6, a rumen bacterium, and optimization of parameters required for its production. Initial screening of five parameters (pH, temperature, agitation, incubation, and substrate concentration) was carried out employing Plackett-Burman design, which reduced the number of parameters to 3 (pH, temperature, and incubation) according to their significance on the yield of biosurfactant. A suitable statistical model for the production of biosurfactant by Pseudomonas sp. BUP6 was established according to Box-Behnken design, which resulted in 11% increase (at pH 7, 35 °C, incubation 75 h) in the yield (2070 mg L(-1) ) of biosurfactant. The biosurfactant was found stable at a wide range of pH (3-9) with 48 mg L(-1) critical micelle concentration; and maintained over 90% of its emulsification ability even after boiling and in presence of sodium chloride (0.5%). The highest cell hydrophobicity (37%) and emulsification (69%) indices were determined with groundnut oil and kerosene, respectively. The biosurfactant was found to inhibit the growth and adhesion of E. coli and S. aureus significantly. From the phytotoxicity studies, the biosurfactant did not show any adverse effect on the germinating seeds of rice and green gram. The structural characterization of biosurfactant employing orcinol method, thin layer chromatography and FT-IR indicated that it is a rhamnolipid (glycolipid). Thus, Pseudomonas sp. BUP6, a novel isolate from Malabari goat is demonstrated as a producer of an efficient rhamnolipid type biosurfactant suitable for application in various industries.

  14. Multipotent stem cells isolated from the adult mouse retina are capable of producing functional photoreceptor cells.

    PubMed

    Li, Tianqing; Lewallen, Michelle; Chen, Shuyi; Yu, Wei; Zhang, Nian; Xie, Ting

    2013-06-01

    Various stem cell types have been tested for their potential application in treating photoreceptor degenerative diseases, such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD). Only embryonic stem cells (ESCs) have so far been shown to generate functional photoreceptor cells restoring light response of photoreceptor-deficient mice, but there is still some concern of tumor formation. In this study, we have successfully cultured Nestin(+)Sox2(+)Pax6(+) multipotent retinal stem cells (RSCs) from the adult mouse retina, which are capable of producing functional photoreceptor cells that restore the light response of photoreceptor-deficient rd1 mutant mice following transplantation. After they have been expanded for over 35 passages in the presence of FGF and EGF, the cultured RSCs still maintain stable proliferation and differentiation potential. Under proper differentiation conditions, they can differentiate into all the major retinal cell types found in the adult retina. More importantly, they can efficiently differentiate into photoreceptor cells under optimized differentiation conditions. Following transplantation into the subretinal space of slowly degenerating rd7 mutant eyes, RSC-derived photoreceptor cells integrate into the retina, morphologically resembling endogenous photoreceptors and forming synapases with resident retinal neurons. When transplanted into eyes of photoreceptor-deficient rd1 mutant mice, a RP model, RSC-derived photoreceptors can partially restore light response, indicating that those RSC-derived photoreceptors are functional. Finally, there is no evidence for tumor formation in the photoreceptor-transplanted eyes. Therefore, this study has demonstrated that RSCs isolated from the adult retina have the potential of producing functional photoreceptor cells that can potentially restore lost vision caused by loss of photoreceptor cells in RP and AMD.

  15. A novel SHV-type beta-lactamase variant (SHV-89) in clinical isolates in China.

    PubMed

    Li, Jia-Bin; Cheng, Jun; Wang, Qian; Chen, Yan; Ye, Ying; Zhang, Xue-Jun

    2009-05-01

    Two clinical strains of Klebsiella pneumoniae (K. pneumoniae) and one isolate of Escherichia coli (E. coli) were collected from two large general hospitals in China. Conjugation experiment, susceptibility testing, isoelectric focusing, PCR, and sequencing techniques as well as clone, expression, purification and kinetics were carried out to describe the characterization of the novel SHV-tpye enzyme. The analysis of plasmid profiling and pulsed-field gel electrophoresis of the novel enzyme were performed to investigate epidemiology. These isolates had CTX-M-14 and SHV-89 beta-lactamases. SHV-89 beta-lactamase of pI 7.6 is a novel variant with two substitutions compared with the sequence of SHV-1: Leu35Gln and Met129Val. Its gene also had two silent mutations at positions 369 and 774, respectively. The results of substrate profiles and MIC determinations showed the activity of the novel enzyme was insufficient for the enzyme to count as an extended-spectrum beta-lactamase (ESBL). The substrates of the enzyme were also characterized. Furthermore, the three novel SHV enzyme-producing strains were epidemiologically unrelated. The emergence of a novel SHV-type beta-lactamase is rarely described in other areas. This study illustrates the importance of molecular survelliance in tracking SHV-producing strains in large teaching hospitals and emphasizes the need for epidemiological monitoring.

  16. The role of horizontal gene transfer in the dissemination of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates in an endemic setting

    PubMed Central

    Doi, Yohei; Adams-Haduch, Jennifer M.; Peleg, Anton Y.; D’Agata, Erika MC

    2012-01-01

    The contribution of horizontal gene transmission (HGT) in the emergence and spread of extended-spectrum beta-lactamase (ESBL)-producing gram-negative bacteria during periods of endemicity is unclear. Over a 12-month period, rectal colonization with SHV-5 and SHV-12 producing-Escherichia coli and Klebsiella pneumoniae was quantified among a cohort of residents in a long-term care facility. Demographic and clinical data were collected on colonized residents. Transferability of SHV-encoding plasmids and pulsed-field gel electrophoresis was performed to quantify the contribution of HGT and cross-transmission, respectively. A total of 25 (12%) of 214 enrolled patients were colonized with 11 SHV-5- and 17 SVH-12-producing E. coli and K. pneumoniae. Clonally-related isolates were detected among multiple residents residing on the same and different wards. Among 12 clonally-distinct isolates, HGT of SHV-5- and SHV-12-encoding plasmids was identified among 6 (50%) isolates. HGT among clonally-distinct strains contributes to the transmission dynamics of these ESBL-producing gram-negative bacteria and should be considered when evaluating the spread of these pathogens. PMID:22722012

  17. Isolation and biochemical characterisation of a bacteriocin-like substance produced by Bacillus amyloliquefaciens An6.

    PubMed

    Ayed, Hanen Ben; Maalej, Hana; Hmidet, Noomen; Nasri, Moncef

    2015-12-01

    This study focuses on the isolation and characterisation of a peptide with bacteriocin-like properties from Bacillus amyloliquefaciens An6. Incubation conditions were optimised, and the effects of the incubation period and of carbon and nitrogen sources were investigated. The produced bacteriocin was partially purified with ammonium sulphate precipitation, dialysis and ultrafiltration and was then biochemically characterised. Maximum bacteriocin production was achieved after 48h of incubation in a culture medium containing 20g/L starch and 10g/L yeast extract, with an initial pH 8.0 at 30°C under continuous agitation at 200rpm. The bacteriocin was sequentially purified and its molecular weight was determined to be 11kDa by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The bacteriocin was relatively heat-resistant and was not sensitive to acid and alkaline conditions (pH 4.0-10.0). Its inhibitory activity was sensitive to proteinase K but was resistant to the proteolytic action of alcalase, trypsin, chymotrypsin and pepsin. In conclusion, bacteriocin An6, owing its wide spectrum of activity as well as its high tolerance to acidic and alkaline pH values, temperature and proteases shows great potential for use as a food biopreservative.

  18. Antimicrobial activity of saquayamycins produced by Streptomyces spp. PAL114 isolated from a Saharan soil.

    PubMed

    Aouiche, A; Bijani, C; Zitouni, A; Mathieu, F; Sabaou, N

    2014-06-01

    A new strain of actinomycete designated PAL114, producing antimicrobial compounds, was isolated from a Saharan soil in Ghardaïa, Algeria. Morphological and chemical studies showed that this strain belonged to the genus Streptomyces. Two bioactive compounds, named P41A and P41B, were extracted by dichloromethane from the cell-free supernatant broth of strain PAL114 and were purified by HPLC. Minimum inhibitory concentrations of the pure antibiotics were determined against yeasts, filamentous fungi and bacteria, most of which are pathogenic or toxigenic for human and multiresistant to antibiotics. The strongest activities were observed against Candida albicans M3 and Bacillus subtilis ATCC 6633. The chemical structures of the compounds were determined by spectroscopic analysis of UV-visible and 1H and 13C NMR spectra and spectrometric analysis of mass spectrum. The compounds P41A and P41B were identified as saquayamycins A and C, respectively. These compounds belong to the aquayamycin-group antibiotics, which are known in the literature for their anticancer and antibacterial activities.

  19. Removal Capacities of Polycyclic Aromatic Hydrocarbons (PAHs) by a Newly Isolated Strain from Oilfield Produced Water.

    PubMed

    Qi, Yi-Bin; Wang, Chen-Yu; Lv, Cheng-Yuan; Lun, Zeng-Min; Zheng, Cheng-Gang

    2017-02-22

    The polycyclic aromatic hydrocarbon (PAH)-degrading strain Q8 was isolated from oilfield produced water. According to the analysis of a biochemical test, 16S rRNA gene, house-keeping genes and DNA-DNA hybridization, strain Q8 was assigned to a novel species of the genus Gordonia. The strain could not only grow in mineral salt medium (MM) and utilize naphthalene and pyrene as its sole carbon source, but also degraded mixed naphthalene, phenanthrene, anthracene and pyrene. The degradation ratio of these four PAHs reached 100%, 95.4%, 73.8% and 53.4% respectively after being degraded by Q8 for seven days. A comparative experiment found that the PAHs degradation efficiency of Q8 is higher than that of Gordonia alkaliphila and Gordonia paraffinivorans, which have the capacities to remove PAHs. Fourier transform infrared spectra, saturate, aromatic, resin and asphaltene (SARA) and gas chromatography-mass spectrometry (GC-MS) analysis of crude oil degraded by Q8 were also studied. The results showed that Q8 could utilize n-alkanes and PAHs in crude oil. The relative proportions of the naphthalene series, phenanthrene series, thiophene series, fluorene series, chrysene series, C21-triaromatic steroid, pyrene, and benz(a)pyrene were reduced after being degraded by Q8. Gordonia sp. nov. Q8 had the capacity to remediate water and soil environments contaminated by PAHs or crude oil, and provided a feasible way for the bioremediation of PAHs and oil pollution.

  20. Thermostable Bacterial Bioflocculant Produced by Cobetia Spp. Isolated from Algoa Bay (South Africa)

    PubMed Central

    Ugbenyen, Anthony; Cosa, Sekelwa; Mabinya, Leonard; Babalola, Olubukola O.; Aghdasi, Farhad; Okoh, Anthony

    2012-01-01

    A novel bioflocculant-producing bacteria was isolated from sediment samples of Algoa Bay in the Eastern Cape Province of South Africa and the effect of culture conditions on the bioflocculant production was investigated. Analysis of the partial nucleotide sequence of the 16S rDNA of the bacteria revealed 99% similarity to Cobetia sp. L222 and the sequence was deposited in GenBank as Cobetia sp. OAUIFE (accession number JF799092). Cultivation condition studies revealed that bioflocculant production was optimal with an inoculum size of 2% (v/v), initial pH of 6.0, Mn2+ as the metal ion, and glucose as the carbon source. Metal ions, including Na+, K+, Li+, Ca2+and Mg2+ stimulated bioflocculant production, resulting in flocculating activity of above 90%. This crude bioflocculant is thermally stable, with about 78% of its flocculating activity remaining after heating at 100 °C for 25 min. Analysis of the purified bioflocculant revealed it to be an acidic extracellular polysaccharide. PMID:22829793

  1. Thermostable bacterial bioflocculant produced by Cobetia spp. isolated from Algoa Bay (South Africa).

    PubMed

    Ugbenyen, Anthony; Cosa, Sekelwa; Mabinya, Leonard; Babalola, Olubukola O; Aghdasi, Farhad; Okoh, Anthony

    2012-06-01

    A novel bioflocculant-producing bacteria was isolated from sediment samples of Algoa Bay in the Eastern Cape Province of South Africa and the effect of culture conditions on the bioflocculant production was investigated. Analysis of the partial nucleotide sequence of the 16S rDNA of the bacteria revealed 99% similarity to Cobetia sp. L222 and the sequence was deposited in GenBank as Cobetia sp. OAUIFE (accession number JF799092). Cultivation condition studies revealed that bioflocculant production was optimal with an inoculum size of 2% (v/v), initial pH of 6.0, Mn(2+) as the metal ion, and glucose as the carbon source. Metal ions, including Na(+), K(+), Li(+), Ca(2+)and Mg(2+) stimulated bioflocculant production, resulting in flocculating activity of above 90%. This crude bioflocculant is thermally stable, with about 78% of its flocculating activity remaining after heating at 100 °C for 25 min. Analysis of the purified bioflocculant revealed it to be an acidic extracellular polysaccharide.

  2. Removal Capacities of Polycyclic Aromatic Hydrocarbons (PAHs) by a Newly Isolated Strain from Oilfield Produced Water

    PubMed Central

    Qi, Yi-Bin; Wang, Chen-Yu; Lv, Cheng-Yuan; Lun, Zeng-Min; Zheng, Cheng-Gang

    2017-01-01

    The polycyclic aromatic hydrocarbon (PAH)-degrading strain Q8 was isolated from oilfield produced water. According to the analysis of a biochemical test, 16S rRNA gene, house-keeping genes and DNA–DNA hybridization, strain Q8 was assigned to a novel species of the genus Gordonia. The strain could not only grow in mineral salt medium (MM) and utilize naphthalene and pyrene as its sole carbon source, but also degraded mixed naphthalene, phenanthrene, anthracene and pyrene. The degradation ratio of these four PAHs reached 100%, 95.4%, 73.8% and 53.4% respectively after being degraded by Q8 for seven days. A comparative experiment found that the PAHs degradation efficiency of Q8 is higher than that of Gordonia alkaliphila and Gordonia paraffinivorans, which have the capacities to remove PAHs. Fourier transform infrared spectra, saturate, aromatic, resin and asphaltene (SARA) and gas chromatography–mass spectrometry (GC–MS) analysis of crude oil degraded by Q8 were also studied. The results showed that Q8 could utilize n-alkanes and PAHs in crude oil. The relative proportions of the naphthalene series, phenanthrene series, thiophene series, fluorene series, chrysene series, C21-triaromatic steroid, pyrene, and benz(a)pyrene were reduced after being degraded by Q8. Gordonia sp. nov. Q8 had the capacity to remediate water and soil environments contaminated by PAHs or crude oil, and provided a feasible way for the bioremediation of PAHs and oil pollution. PMID:28241412

  3. Enterobacter siamensis sp. nov., a transglutaminase-producing bacterium isolated from seafood processing wastewater in Thailand.

    PubMed

    Khunthongpan, Suwannee; Bourneow, Chaiwut; H-Kittikun, Aran; Tanasupawat, Somboon; Benjakul, Soottawat; Sumpavapol, Punnanee

    2013-01-01

    A novel strain of Enterobacter, C2361(T), a Gram-negative, non-spore-forming, rod-shaped and facultative anaerobic bacterium with the capability to produce transglutaminase, was isolated from seafood processing wastewater collected from a treatment pond of a seafood factory in Songkhla Province, Thailand. Phylogenetic analyses and phenotypic characteristics, including chemotaxonomic characteristics, showed that the strain was a member of the genus Enterobacter. The 16S rRNA gene sequence similarities between strain C2361(T) and Enterobacter cloacae subsp. cloacae ATCC 13047(T) and Enterobacter cloacae subsp. dissolvens LMG 2683(T) were 97.5 and 97.5%, respectively. Strain C2361(T) showed a low DNA-DNA relatedness with the above-mentioned species. The major fatty acids were C16:0, C17:0cyclo and C14:0. The DNA G+C content was 53.0 mol%. On the basis of the polyphasic evidence gathered in this study, it should be classified as a novel species of the genus Enterobacter for which the name Enterobacter siamensis sp. nov. is proposed. The type strain is C2361(T) (= KCTC 23282(T) = NBRC 107138(T)).

  4. Production and partial characterization of exopolysaccharides produced by two Lactobacillus suebicus strains isolated from cider.

    PubMed

    Ibarburu, Idoia; Puertas, Ana Isabel; Berregi, Iñaki; Rodríguez-Carvajal, Miguel A; Prieto, Alicia; Dueñas, Ma Teresa

    2015-12-02

    Many lactic acid bacteria synthesize extracellular polysaccharides (exopolysaccharides, EPSs) with a large variation in structure and potential functional properties. Although EPS production can produce detrimental effects in alcoholic beverages, these polymers play an important role in the rheological behavior and texture of fermented products. In this work, EPS production by two Lactobacillus suebicus strains, which were isolated from ropy ciders, was examined in a semidefined medium. The existence of priming glycosyltransferase encoding genes was detected by PCR. In addition, the preliminary characterization of the polymers was undertaken. Molecular masses were determined by size exclusion chromatography revealing the presence of two peaks, corresponding to polymers of high- and low-molecular-weight in all fractions. The composition of the EPS fractions was analyzed by gas chromatography-mass spectrometry after acid hydrolysis, revealing that they contained glucose, galactose, N-acetylglucosamine and phosphate, although in different ratios, suggesting that a mixture of polysaccharides is being synthesized. We also examined the influence of the sugar source (glucose, ribose, xylose, or arabinose) and pH conditions on growth and EPS production.

  5. Isolation and characterization of Linocin M18, a bacteriocin produced by Brevibacterium linens.

    PubMed

    Valdés-Stauber, N; Scherer, S

    1994-10-01

    Brevibacterium linens M18, isolated from red smear cheese, produces a substance that inhibits the growth of Listeria spp. and several coryneform and other gram-positive bacteria. No gram-negative bacteria were inhibited. The substance is heat labile, sensitive to proteolytic enzymes, and stable between pH 3 and 12. High levels of this bacteriocin, named Linocin M18, were obtained in the stationary growth phase. Linocin M18 was purified by ultrafiltration, ultracentrifugation, and gel filtration chromatography. In its native form, it is a proteinaceous aggregate with a high molecular weight. Fractions with Linocin M18 activity contained particles of 20 to 30 nm in diameter. The bacteriocin consists of a single protein subunit with a molecular mass of 31 kDa and an isoelectric point of 4.5 N-terminal sequence analysis yielded Met-Asn-Asn-Leu-Tyr-Arg-Glu-Leu-Ala-Pro-Ile-Pro-Gly-Pro-Ala-Ala-Ala-Glu- Ile. Significant homology with published sequences was lacking.

  6. A polyphasic approach to the identification of ochratoxin A-producing black Aspergillus isolates from vineyards in Sicily.

    PubMed

    Oliveri, C; Torta, L; Catara, V

    2008-09-30

    Aspergillus strains belonging to section Nigri isolated during a two year survey in eight Sicilian vineyards located on the slopes of Mount Etna (Sicily, Italy) were analysed analyzed in order to characterize species responsible for ochratoxin A (OTA) contamination of grapes. The polyphasic approach permitted analysis of biodiversity of Aspergillus isolates in relation to their morphology, ochratoxigenicity and genetic variability. We assessed OTA production by A. carbonarius, A. niger, A. tubingensis and A. japonicus using an enzyme-linked immunosorbent assay. A. carbonarius isolates were the strongest OTA producers. A subset of 66 representative strains was selected for further DNA-based characterization. PCR assays using species-specific primers discriminated between A. niger, A. carbonarius and A. japonicus on the basis of the target sequences for each species. The PCR-based methods matched morphological characterization in identifying all the black aspergilli (BA) isolates tested, whereas RFLP analysis with RsaI of isolates positive to PCRs with A. niger specific primers identified three A. tubingensis isolates. The identification of thirteen isolates was further confirmed by ITS analysis. By this method, each of the isolates was identified and assigned to an Aspergillus species. The fAFLP analysis of 40 isolates highlighted the power of this technique to discriminate different species and single strains, to verify the presence of mixed populations in the same vineyard, through homogeneous species clusters. No correlation was observed between the clusters and OTA production level or origin.

  7. In vitro Characterization of Bacteriocin Produced by Lactic Acid Bacteria Isolated from Nem Chua, a Traditional Vietnamese Fermented Pork.

    PubMed

    Pilasombut, Komkhae; Rumjuankiat, Kittaporn; Ngamyeesoon, Nualphan; Duy, Le Nguyen Doan

    2015-01-01

    The aim of this study was to screen and In vitro characterize the properties of bacteriocin produced by lactic acid bacteria isolated from Vietnamese fermented pork (Nem chua). One hundred and fifty LAB were isolated from ten samples of Nem chua and screened for bacteriocin-producing lactic acid bacteria. Antimicrobial activity of bacteriocin was carried out by spot on lawn method against both gram positive and gram negative bacteria. One isolate, assigned as KL-1, produced bacteriocin and showed inhibitory activity against Lactobacillus sakei, Leuconostoc mesenteroides and Enterococcus faecalis. To characterize the bacteriocin-producing strain, optimum temperature, incubation period for maximum bacteriocin production and identification of bacteriocin-producing strain were determined. It was found that the optimum cultivation temperature of the strain to produce the maximum bacteriocin activity (12,800 AU/mL) was obtained at 30℃. Meanwhile, bacteriocin production at 6,400 AU/mL was found when culturing the strain at 37℃ and 42℃. The isolate KL-1 was identified as L. plantarum. Antimicrobial activity of cell-free supernatant was completely inhibited by proteolytic enzyme of trypsin, alpha-chymotrypsin and proteinase K. Bacteriocin activity was stable at high temperature up to 100℃ for 10 min and at 4℃ storage for 2 d. However, the longer heating at 100℃ and 4℃ storage, its activity was reduced.

  8. Clinical distribution and antibiotic sensitivities of staphylococcal strains isolated over an eight-month period.

    PubMed Central

    Varaldo, P E; Soro, O; Grazi, G; Biavasco, F

    1981-01-01

    A total of 842 staphylococci isolated from clinical material over an eight-month period and regarded as probable pathogens were identified according to lyogroup. Almost half the isolates belonged to lyogroups other than lyogroup I (Staphylococcus aureus), suggesting that coagulase-negative staphylococci are increasingly involved in human infections. All isolates were tested for sensitivity to 12 antibiotics. A greater resistance was observed in non-lyogroup I isolates, which again suggests a pathogenic significance of coagulase-negative staphylococci. Only lyogroup I strains, however, were obtained more frequently from clinical isolates than from healthy human skin. The distribution of the isolates in each lyogroup according to their clinical source is reported. PMID:7240433

  9. Surface-associated motility, a common trait of clinical isolates of Acinetobacter baumannii, depends on 1,3-diaminopropane.

    PubMed

    Skiebe, Evelyn; de Berardinis, Véronique; Morczinek, Peter; Kerrinnes, Tobias; Faber, Franziska; Lepka, Daniela; Hammer, Bettina; Zimmermann, Ortrud; Ziesing, Stefan; Wichelhaus, Thomas A; Hunfeld, Klaus-Peter; Borgmann, Stefan; Gröbner, Sabine; Higgins, Paul G; Seifert, Harald; Busse, Hans-Jürgen; Witte, Wolfgang; Pfeifer, Yvonne; Wilharm, Gottfried

    2012-07-01

    While flagella-independent motility has long been described in representatives of the genus Acinetobacter, the mechanism of motility remains ambiguous. Acinetobacter baumannii, a nosocomial pathogen appearing increasingly multidrug-resistant, may profit from motility during infection or while persisting in the hospital environment. However, data on the frequency of motility skills among clinical A. baumannii isolates is scarce. We have screened a collection of 83 clinical A. baumannii isolates of different origin and found that, with the exception of one isolate, all were motile on wet surfaces albeit to varying degrees and exhibiting differing morphologies. Screening a collection of transposon mutants of strain ATCC 17978 for motility defects, we identified 2 akinetic mutants carrying transposon insertions in the dat and ddc gene, respectively. These neighbouring genes contribute to synthesis of 1,3-diaminopropane (DAP), a polyamine ubiquitously produced in Acinetobacter. Supplementing semi-solid media with DAP cured the motility defect of both mutants. HPLC analyses confirmed that DAP synthesis was abolished in ddc and dat mutants of different A. baumannii isolates and was re-established after genetic complementation. Both, the dat and ddc mutant of ATCC 17978 were attenuated in the Galleria mellonella caterpillar infection model. Taken together, surface-associated motility is a common trait of clinical A. baumannii isolates that requires DAP and may play a role in its virulence.

  10. Antifungal susceptibility of 175 Aspergillus isolates from various clinical and environmental sources.

    PubMed

    Sabino, Raquel; Carolino, Elisabete; Veríssimo, Cristina; Martinez, Marife; Clemons, Karl V; Stevens, David A

    2016-10-01

    Some environmental Aspergillus spp. isolates have been described as resistant to antifungals, potentially causing an emerging medical problem. In the present work, the antifungal susceptibility profile of 41 clinical and 134 environmental isolates of Aspergillus was determined using the CLSI microdilution method. The aim of this study was to compare environmental and clinical isolates with respect to their susceptibility, and assess the potential implications for therapy of isolates encountered in different environments. To our knowledge, this is the first report comparing antifungal susceptibility profiles of Aspergillus collected from different environmental sources (poultries, swineries, beach sand, and hospital environment). Significant differences were found in the distribution of the different species sections for the different sources. Significant differences were also found in the susceptibility profile of the different Aspergillus sections recovered from the various sources. Clear differences were found between the susceptibility of clinical and environmental isolates for caspofungin, amphotericin B and posaconazole, with clinical isolates showing overall greater susceptibility, except for caspofungin. In comparison to clinical isolates, hospital environmental isolates showed significantly less susceptibility to amphotericin B and posaconazole. These data indicate that species section identity and the site from which the isolate was recovered influence the antifungal susceptibility profile, which may affect initial antifungal choices.

  11. Predominance of Clostridium difficile Ribotypes 017 and 078 among Toxigenic Clinical Isolates in Southern Taiwan

    PubMed Central

    Hung, Yuan-Pin; Huang, I-Hsiu; Lin, Hsiao-Ju; Tsai, Bo-Yang; Liu, Hsiao-Chieh; Liu, Hsiu-Chuan; Lee, Jen-Chieh; Wu, Yi-Hui; Tsai, Pei-Jane; Ko, Wen-Chien

    2016-01-01

    Ribotypes and toxin genotypes of clinical C. difficile isolates in Taiwan are rarely reported. A prospective surveillance study from January 2011 to January 2013 was conducted at the medical wards of a district hospital in southern Taiwan. Of the first toxigenic isolates from 120 patients, 68 (56.7%) of 120 isolates possessed both tcdA and tcdB. Of 52 (43.3%) with tcdB and truncated tcdA (tcdA-/tcdB+), all were ribotype 017 and none had binary toxin or tcdC deletion. Eighteen (15%) toxigenic isolates harbored binary toxins (cdtA and cdtB) and all had tcdC deletion, including Δ39 (C184T) deletion (14 isolates), Δ18 in-frame deletion (3 isolates), and Δ18 (Δ117A) deletion (1 isolate). Eleven of 14 isolates with Δ39 (C184T) deletion belonged to the ribotype 078 family, including ribotype 127 (6 isolates), ribotype 126 (4 isolates), and ribotype 078 (1 isolate). Among 8 patients with consecutive C. difficile isolates, these isolates from 6 (75%) patients were identical, irrespective of the presence or absence of diarrhea, suggestive of persistent fecal carriage or colonization. In conclusion in southern Taiwan, ribotype 017 isolates with a tcdA-/tcdB+ genotype were not uncommon and of C. difficile isolates with binary toxin, the ribotype 078 family was predominant. PMID:27861606

  12. Genotypes of Clinical and Environmental Isolates of Cryptococcus neoformans and Cryptococcus gattii in Korea

    PubMed Central

    Park, So Hae; Choi, Seok Cheol; Lee, Kyung Won; Kim, Mi-Na

    2015-01-01

    Multilocus sequence typing analysis was applied to determine the genotypes of 147 (137 clinical and 10 environmental) Cryptococcus neoformans and three clinical Cryptococcus gattii isolates from 1993 to 2014 in Korea. Among the 137 clinical isolates of C. neoformans, the most prevalent genotype was ST5 (n = 131), followed by ST31 (n = 5) and ST127 (n = 1). Three C. gattii strains were identified as ST57, ST7, and ST113. All environmental isolates were identified as C. neoformans with two genotypes, ST5 (n = 7) and ST31 (n = 3). Our results show that C. neoformans isolates in Korea are genetically homogeneous, and represent a close genetic relationship between clinical and environmental isolates. PMID:26539057

  13. [Isolation of thermostable direct hemolysin producing Vibrio parahaemolyticus from food using screening by PCR in food-borne outbreaks].

    PubMed

    Obata, Hiromi; Shimojima, Yukako; Konishi, Noriko; Monma, Chie; Yano, Kazuyoshi; Kai, Akemi; Morozumi, Satoshi; Fukuyama, Masafumi

    2006-07-01

    The producibility of thermostable direct hemolysin (TDH) is the most important pathogenic factor in Vibrio parahaemolyticus. TDH (+) V. parahaemolyticus is usually isolated from patients having V. parahaemolyticus food-borne disease. TDH (+) V. parahaemolyticus is, however, very difficult to isolate from food and environmental samples. In the 5 years from 2000 to 2004 in Tokyo, V. parahaemolyticus was isolated from food samples related to 67 of 227 V parahaemolyticus food-borne outbreaks. In these outbreaks, TDH (+) strains were also tried to isolate using PCR as the screening methods. TDH (+) V. parahaemolyticus strains were able to isolate from enrichment broth in which toxR and tdh genes become positive in PCR. TDH (+) strains of the same serotype with patients were able to be isolated from 23 food samples related to 11 outbreaks (16.4%); 3 outbreaks in 2000, 2 in 2001, 2 in 2002, 1 in 2003, and 3 in 2004. The serotypes of V. parahaemolyticus isolated from food were O3 : K6 (10 samples), O3 : K5 (6 samples), O1 : K25 (4 samples), O3 : K29 (2 samples), O4 : K 8 (1 sample), and O4 : K11 (1 sample). The isolation rate of the TDH (+) strain from enrichment broth differed with samples. In several samples TDH (+) strains were isolated easily only by examining 3 colonies, hence no TDH (+) strains were isolated in spite of the examination of 250 colonies. No correlation was seen between the number of V. parahaemolyticus and the isolation rate of TDH (+) strains in food samples. Screening using PCR is very effective method for isolating TDH (+) V. parahaemolyticus from food samples.

  14. 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

  15. A comparative study of clinical and food isolates of Listeria monocytogenes and related species.

    PubMed Central

    Szabo, E. A.; Desmarchelier, P. M.

    1990-01-01

    Ninety-six isolates of presumptive or confirmed Listeria monocytogenes were obtained from local clinical (30 isolates) or food laboratories (66 isolates). Minimal biochemical analysis identified only 80% of these isolates as L. monocytogenes the remaining included L. seeligeri, 1%, or the non-haemolytic L. innocua, 19%. The 27 clinical and 50 food isolates, mainly from meat products, frozen confectionaries, and cheeses, confirmed as L. monocytogenes were compared biochemically and serologically. Twenty-one isolates, including some strains of L. innocua and L. seeligeri, were examined for pathogenicity in immunocompromized mice and 44 typed using bacterial restriction endonuclease DNA analysis (BRENDA). Only isolates of L. monocytogenes were found to be pathogenic. Biovar-typing of the isolates was unreliable and provided poor discrimination. Serogroups 1/2 and 4 predominated among clinical and food isolates and BRENDA provided better discrimination among isolates. Ten stable and reproducible restriction patterns were observed among the Listeria sp. isolates studied. Overall, a combination of techniques gave the best discrimination and indicated their potential for use as epidemiological tools. Images Fig. 1 PMID:2120079

  16. Dystonia and Tremor: The Clinical Syndromes with Isolated Tremor

    PubMed Central

    Albanese, Alberto; Sorbo, Francesca Del

    2016-01-01

    Background Dystonia and tremor share many commonalities. Isolated tremor is part of the phenomenological spectrum of isolated dystonia and of essential tremor. The occurrence of subtle features of dystonia may allow one to differentiate dystonic tremor from essential tremor. Diagnostic uncertainty is enhanced when no features of dystonia are found in patients with a tremor syndrome, raising the question whether the observed phenomenology is an incomplete form of dystonia. Methods Known forms of syndromes with isolated tremor are reviewed. Diagnostic uncertainties between tremor and dystonia are put into perspective. Results The following isolated tremor syndromes are reviewed: essential tremor, head tremor, voice tremor, jaw tremor, and upper-limb tremor. Their varied phenomenology is analyzed and appraised in the light of a possible relationship with dystonia. Discussion Clinicians making a diagnosis of isolated tremor should remain vigilant for the detection of features of dystonia. This is in keeping with the recent view that isolated tremor may be an incomplete phenomenology of dystonia. PMID:27152246

  17. Isotopologue signatures of nitrous oxide produced by nitrate-ammonifying bacteria isolated from soil

    NASA Astrophysics Data System (ADS)

    Behrendt, Undine; Well, Reinhard; Giesemann, Anette; Ulrich, Andreas; Augustin, Jürgen

    2015-04-01

    Agricultural soils are the largest single source of anthropogenic N2O to the atmosphere, primarily driven by microbiological processes such as denitrification and dissimilatory nitrate reduction to ammonium (DNRA). Both processes occur under similar conditions of low oxygen concentration and therefore, source partitioning of emitted N2O is difficult. Understanding what controls the dynamics and reaction equilibrium of denitrification and DNRA is important and may allow the development of more effective mitigation strategies. 15N site preference (SP), i.e. the difference between 15N of the central and peripheral N-position of the asymmetric N2O molecule, differs depending on processes involved in N2O formation. Hence investigation of the isotopomer ratios of formed N2O potentially presents a reliable mean to identify its source. In this study, bacterial isolates obtained from organic soils were screened for their ability to reduce nitrate/nitrite to ammonium and to release N2O to the atmosphere. Taxonomic characterisation of the strains revealed that N2O formation was only detected in ammonifying strains affiliated to several genera of the family Enterobacteriaceae and strains belonging to the genus Bacillus and Paenibacillus. Sampling of N2O was conducted by incubation of strains under oxic and anoxic conditions. Investigation of the 15N site preference showed SP values in the range of 39 to 57 o . Incubation conditions had no influence on the SP. The lowest values were achieved by a strain of the species Escherichia coli which was included in this study as a DNRA reference bacterium harbouring the NrfA gene that is coding the nitrite reductase, associated with respiratory nitrite ammonification. Soil isolates showed SP-values higher than 40 o . Comparison of these results with SP-values of N2O produced by denitrifying bacteria in pure cultures (-5 to 0 o )^[1, 2]revealedsignificantdifferences.Incontrast,N_2OproducedbydenitrifyingfungidisplayedSP - valuesinarangeof

  18. Micromonospora schwarzwaldensis sp. nov., a producer of telomycin, isolated from soil.

    PubMed

    Vela Gurovic, Maria Soledad; Müller, Sebastian; Domin, Nicole; Seccareccia, Ivana; Nietzsche, Sandor; Martin, Karin; Nett, Markus

    2013-10-01

    A Gram-stain-positive, spore-forming actinomycete strain (HKI0641(T)) was isolated from a soil sample collected in the Black Forest, Germany. During screening for antimicrobial natural products this bacterium was identified as a producer of the antibiotic telomycin. Morphological characteristics and chemotaxonomic data indicated that the strain belonged to the genus Micromonospora. The peptidoglycan of strain HKI0641(T) contained meso-diaminopimelic acid, and the fatty acid profile consisted predominantly of anteiso-C15 : 0, iso-C15 : 0, iso-C16 : 0 and C16 : 0. MK-10(H4), MK-10(H2) and MK-10 were identified as the major menaquinones. To determine the taxonomic positioning of strain HKI0641(T), we computed a binary tanglegram of two rooted phylogenetic trees that were based upon 16S rRNA and gyrB gene sequences. The comparative analysis of the two common classification methods strongly supported the phylogenetic affiliation with the genus Micromonospora, but it also revealed discrepancies in the assignment at the level of the genomic species. 16S rRNA gene sequence analysis identified Micromonospora coxensis DSM 45161(T) (99.1 % sequence similarity) and Micromonospora marina DSM 45555(T) (99.0 %) as the nearest taxonomic neighbours, whereas the gyrB sequence of strain HKI0641(T) indicated a closer relationship to Micromonospora aurantiaca DSM 43813(T) (95.1 %). By means of DNA-DNA hybridization experiments, it was possible to resolve this issue and to clearly differentiate strain HKI0641(T) from other species of the genus Micromonospora. The type strains of the aforementioned species of the genus Micromonospora could be further distinguished from strain HKI0641(T) by several phenotypic properties, such as colony colour, NaCl tolerance and the utilization of carbon sources. The isolate was therefore assigned to a novel species of the genus Micromonospora, for which the name Micromonospora schwarzwaldensis sp. nov. is proposed. The type strain

  19. Isolation and molecular characterization of Salmonella enterica serovar Javiana from food, environmental and clinical samples.

    PubMed

    Mezal, Ezat H; Stefanova, Rossina; Khan, Ashraf A

    2013-06-03

    A total of 50 Salmonella enterica serovar Javiana isolates, isolated from food, environmental and clinical samples, were analyzed for antibiotic resistance, presence of virulence genes, plasmids and plasmid replicon types. To assess the genetic diversity, pulsed-field gel electrophoresis (PFGE) fingerprinting and plasmid profiles were performed. All of the isolates were sensitive to chloramphenicol, nalidixic acid, and sulfisoxazole, and four isolates showed intermediate resistance to gentamicin or kanamycin. Eleven isolates, including representatives from each of the source types, were resistant to ampicillin. Four isolates from either clinical or environmental sources were resistant to tetracycline, while an additional 20 isolates showed intermediate resistance to this drug. Fourteen isolates, primarily from food sources, showed intermediate resistance to streptomycin. The S. Javiana isolates were screened by PCR for 17 virulence genes (spvB, spiA, pagC, msgA, invA, sipB, prgH, spaN, orgA, tolC, iroN, sitC, IpfC, sifA, sopB, cdtB, and pefA). All isolates were positive for nine to fourteen of these genes, but none were positive for pefA, spvB and lpfC, which are typically present on the Salmonella virulence plasmid. Seven of the virulence genes including cdtB were found in all 50 isolates, suggesting that S. Javiana from food and environmental sources had virulence similar to clinical isolates. Four clinical isolates and two food isolates carried one or more plasmids of approximately 30, 38, and 58 kb, with the 58 kb plasmids belonging to incompatibility group IncFIIA. Two clinical isolates carried IncI1 type mega plasmid (80 kb), and one clinical isolate carried plasmids of 4.5 and 7 kb. The PFGE profiles resulted 34 patterns in five clusters at a 90% similarity threshold. Our results indicate that S. Javiana isolates have a diverse clonal population among the clinical, food and environmental samples and this serotype possesses several virulent genes and plasmids

  20. Antimicrobial susceptibility of Streptococcus suis isolated from clinically healthy swine in Brazil

    PubMed Central

    Soares, Taíssa Cook Siqueira; Paes, Antonio Carlos; Megid, Jane; Ribolla, Paulo Eduardo Martins; Paduan, Karina dos Santos; Gottschalk, Marcelo

    2014-01-01

    Streptococcus suis is an important pathogen in the swine industry. This study is the first to report on the antimicrobial susceptibility of S. suis isolated from clinically healthy pigs in Brazil; the fourth major pork producer in the world. The antimicrobial susceptibility of 260 strains was determined by disc diffusion method. Strains were commonly susceptible to ceftiofur, cephalexin, chloramphenicol, and florfenicol, with more than 80% of the strains being susceptible to these antimicrobials. A high frequency of resistance to some of the antimicrobial agents was demonstrated, with resistance being most common to sulfa-trimethoprim (100%), tetracycline (97.69%), clindamycin (84.61%), norfloxacin (76.92%), and ciprofloxacin (61.15%). A high percentage of multidrug resistant strains (99.61%) were also found. The results of this study indicate that ceftiofur, cephalexin, and florfenicol are the antimicrobials of choice for empirical control of the infections caused by S. suis. PMID:24688177

  1. Analysis on antimicrobial resistance of clinical bacteria isolated from county hospitals and a teaching hospital.

    PubMed

    Sun, Ziyong; Li, Li; Zhu, Xuhui; Ma, Yue; Li, Jingyun; Shen, Zhengyi; Jin, Shaohong

    2006-01-01

    The distinction of antimicrobial resistance of clinical bacteria isolated from county hospitals and a teaching hospital was investigated. Disc diffusion test was used to study the antimicrobial resistance of isolates collected from county hospitals and a teaching hospital. The data was analyzed by WHONET5 and SPSS statistic software. A total of 655 strains and 1682 strains were collected from county hospitals and a teaching hospital, respectively, in the year of 2003. The top ten pathogens were Coagulase negative staphylococci (CNS), E. coli, Klebsiella spp., S. areus, P. aeruginosa, Enterococcus spp., Enterobacter spp., otherwise Salmonella spp., Proteus spp., Shigella spp. in county hospitals and Streptococcus spp., Acinetobacter spp., X. maltophilia in the teaching hospital. The prevalence of multi-drug resistant bacteria was 5% (4/86) of methicillin-resistant S. areus (MRSA), 12% (16/133) and 15.8% (9/57) of extended-spectrum beta-lactamases producing strains of E. coli and Klebsiella spp., respectively, in county hospitals. All of the three rates were lower than that in the teaching hospital and the difference was statistically significant (P < 0. 01). However, the incidence of methicillin-resistant CNS (MRCNS) reached to 70% (109/156) in the two classes of hospitals. Generally, the antimicrobial resistant rates in the county hospitals were lower than those in the teaching hospital, except the resistant rates of ciprofloxacin, erythromycin, clindamycin, SMZco which were similar in the two classes of hospitals. There were differences between county hospitals and the teaching hospital in the distribution of clinical isolates and prevalence of antimicrobial resistance. It was the basis of rational use of antimicrobial agents to monitor antimicrobial resistance by each hospital.

  2. Pseudomonas aeruginosa clinical and environmental isolates constitute a single population with high phenotypic diversity

    PubMed Central

    2014-01-01

    Background Pseudomonas aeruginosa is an opportunistic pathogen with a high incidence of hospital infections that represents a threat to immune compromised patients. Genomic studies have shown that, in contrast to other pathogenic bacteria, clinical and environmental isolates do not show particular genomic differences. In addition, genetic variability of all the P. aeruginosa strains whose genomes have been sequenced is extremely low. This low genomic variability might be explained if clinical strains constitute a subpopulation of this bacterial species present in environments that are close to human populations, which preferentially produce virulence associated traits. Results In this work, we sequenced the genomes and performed phenotypic descriptions for four non-human P. aeruginosa isolates collected from a plant, the ocean, a water-spring, and from dolphin stomach. We show that the four strains are phenotypically diverse and that this is not reflected in genomic variability, since their genomes are almost identical. Furthermore, we performed a detailed comparative genomic analysis of the four strains studied in this work with the thirteen previously reported P. aeruginosa genomes by means of describing their core and pan-genomes. Conclusions Contrary to what has been described for other bacteria we have found that the P. aeruginosa core genome is constituted by a high proportion of genes and that its pan-genome is thus relatively small. Considering the high degree of genomic conservation between isolates of P. aeruginosa from diverse environments, including human tissues, some implications for the treatment of infections are discussed. This work also represents a methodological contribution for the genomic study of P. aeruginosa, since we provide a database of the comparison of all the proteins encoded by the seventeen strains analyzed. PMID:24773920

  3. Molecular typing and antifungal susceptibility of clinical and environmental Cryptococcus neoformans species complex isolates in Goiania, Brazil.

    PubMed

    Souza, L K H; Souza Junior, A H; Costa, C R; Faganello, J; Vainstein, M H; Chagas, A L B; Souza, A C M; Silva, M R R

    2010-01-01

    A total of 124 Cryptococcus isolates, including 84 clinical strains obtained from cerebrospinal fluid from AIDS patients and 40 environmental isolates from pigeon excreta and from Eucalyptus trees, were studied. The varieties, serotypes, phospholipase activity and molecular profile of these isolates were determined. Cryptococcus neoformans var. grubii serotype A was identified in 120 isolates and Cryptococcus gattii serotype B in four isolates. The clinical isolates showed higher phospholipase activity than environmental isolates. Similar patterns of in vitro susceptibility to amphotericin B, fluconazole, itraconazole and voriconazole and no resistance were found for all isolates. Molecular type VNI (C. neoformans var. grubii) was recovered in 80 clinical and 40 environmental isolates while the type VGIII (C. gattii) was found in four clinical isolates. This study demonstrated for the first time the molecular types of clinical and environmental Cryptococcus isolates in the midwest Brazil region.

  4. Molecular identification, antifungal susceptibility profile, and biofilm formation of clinical and environmental Rhodotorula species isolates.

    PubMed

    Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona E; Colombo, Arnaldo Lopes

    2013-01-01

    Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC(50)/MIC(90), 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula

  5. Molecular Identification, Antifungal Susceptibility Profile, and Biofilm Formation of Clinical and Environmental Rhodotorula Species Isolates

    PubMed Central

    Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona e

    2013-01-01

    Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC50/MIC90, 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula species

  6. In vitro susceptibilities of clinical and environmental isolates of Cryptococcus neoformans to five antifungal drugs.

    PubMed Central

    Franzot, S P; Hamdan, J S

    1996-01-01

    A total of 53 Cryptococcus neoformans strains, including clinical and environmental Brazilian isolates, were tested for their susceptibilities to amphotericin B, 5-flucytosine, ketoconazole, fluconazole, and itraconazole. The tests were performed according to the National Committee of Clinical Laboratory Standards recommendations (document M27-P). In general, there was a remarkable homogeneity of results for all strains, and comparable MICs were found for environmental and clinical isolates. This paper represents the first contribution in which susceptibility data for Brazilian C. neoformans isolates are provided. PMID:8851624

  7. Identification and Molecular Characterization of Antimicrobial-Resistant Shiga Toxin–Producing Escherichia coli Isolated from Retail Meat Products

    PubMed Central

    Li, Ming-Cheng; Wang, Fang

    2011-01-01

    Abstract Ten (2.7%) Shiga toxin–producing Escherichia coli (STEC) were isolated from 370 samples of raw minced beef, mutton, pork, and chicken from the Jilin region of China; and additional 10 E. coli O157:H7 isolates were previously isolated from different Jilin regions. Seventeen of the isolates were multiresistant, exhibiting resistance to ampicillin, ciprofloxacin, tetracycline, sulfamethoxazole-trimethoprim, gentamycin, and streptomycin. Class 1 integrons were detected in nine (45.0%) of the STEC isolates and consisted of serogroups O157, O62, O113, O149, and O70. Integrons containing amplicons of a 0.5–1.5 or 1.0 kb gene cassette were found in seven (77.8%) of the integron-containing isolates. Sequencing analysis revealed that these gene cassettes encode genes conferring resistance to trimethoprim (dfrA1) and streptomycin (aadA1). The 0.5 kb cassette described here was found to encode a putative transporter peptide in the STEC. Seventeen isolates contained plasmids with different bands, and transfer by conjugation between strains of E. coli demonstrated that class 1 integrons located on mobile plasmids could contribute to the emergence and dissemination of antimicrobial resistance to ampicillin, gentamycin, streptomycin, and sulfamethoxazole-trimethoprim amongst STEC. These data revealed the high prevalence of antimicrobial-resistant STEC isolates in Jilin's surrounding regions, providing important and useful surveillance information reflecting antimicrobial selection pressure. PMID:21453117

  8. In vitro activity of Melaleuca alternifolia (tea tree) oil against bacterial and Candida spp. isolates from clinical specimens.

    PubMed

    Banes-Marshall, L; Cawley, P; Phillips, C A

    2001-01-01

    This study investigates the in vitro activity of tea tree oil (TTO) against a range of wild strains of microorganisms isolated from clinical specimens of leg ulcers and pressure sores. The antimicrobial effectiveness of TTO is determined in terms of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC). The isolates include methicillin-resistant Staphylococcus aureus (MRSA), S. aureus, faecal streptococci, beta-haemolytic streptococci, coagulase-negative staphylococci, Pseudomonas spp. and coliform bacilli. Eleven Candida spp. isolates from skin and vaginal swabs also are tested. Using an agar dilution assay, the MICs of TTO in 88 out of 90 isolates was 0.5-1.0% (v/v), whilst with P. aeruginosa it was >2% (v/v). A broth microdilution method was used to determine MIC and minimum cidal concentration (MCC) of 80 isolates. In 64 isolates, TTO produced an inhibitory and cidal effect at 3% and 4% (v/v), respectively. S. aureus and Candida spp. were the most susceptible to TTO, with MICs and MBCs of 0.5% and 1%, respectively. P. aeruginosa and the faecal streptococci isolates, with MICs and MBCs of >8%, were resistant to TTO.

  9. Typing of feline calicivirus isolates from different clinical groups by virus neutralisation tests.

    PubMed

    Dawson, S; McArdle, F; Bennett, M; Carter, M; Milton, I P; Turner, P; Meanger, J; Gaskell, R M

    1993-07-03

    One hundred and thirteen isolates of feline calicivirus originating from seven different clinical groups were typed by virus neutralisation tests using eight different cat antisera. The clinical groups comprised 'healthy' cats, cases of acute oral/respiratory disease, chronic stomatitis, acute febrile lameness syndrome, vaccine reactions (clinical disease seen within 21 days of vaccination) and vaccine breakdowns (clinical disease seen more than 21 days after but within one year of vaccination). Isolates from the vaccine reaction cases were grouped into those associated with acute oral/respiratory disease alone and those associated with the lameness syndrome, and the latter group was further subdivided according to the vaccine used. Two groups appeared significantly different from others with some of the antisera. Thus the lameness vaccine reaction isolates associated with vaccine B were significantly different from the isolates from all the other clinical groups, including other lameness isolates, with a number of the antisera. In addition, the chronic stomatitis isolates were significantly different from those from the 'healthy' and the acute oral/respiratory disease groups with one or two of the antisera. Eighty-five to 88 per cent of the isolates were neutralised by antisera raised against F9 or F9-like vaccine strains at a dilution of 1 in 2. Twenty antibody units of such antisera neutralised 42 to 80 per cent of the isolates. A bivalent antiserum raised against a vaccine F9 strain and field strain LS015 neutralised 96 per cent of the isolates at a dilution of 1 in 2, and 20 antibody units neutralised 68 per cent of isolates. Antisera to field strain F65 neutralised all the remaining isolates at a dilution of 1 in 2 and 44 per cent of the remaining isolates at a dilution of 20 antibody units. Therefore, strains LS015 and F65 may be of use in the production of a polyvalent feline calicivirus vaccine, together with the widely used strain F9.

  10. Characterization of new biosurfactant produced by Trichosporon montevideense CLOA 72 isolated from dairy industry effluents.

    PubMed

    Monteiro, Andrea S; Coutinho, Joana O P A; Júnior, Ary C; Rosa, Carlos A; Siqueira, Ezequias P; Santos, Vera L

    2009-12-01

    The yeast strain CLOA 72 isolated from the effluent of a dairy industry in Brazil and identified as Trichosporon montevideense, was able to grow and produce a glycolipid biosurfactant when cultured on a mineral medium (MM) with sunflower oil as the carbon source. Biosurfactant production was partially growth-associated and maximal emulsification activity was observed at 144 h of cultivation (78.92%). The biosurfactant purified by precipitation with ethanol showed 78.66% emulsifying activity when used in concentrations above 4.5 mg/ml and was able to reduce the surface tension of water to values below 44.9 mN/m. The critical micellar concentration (CMC) was found to be 2.2 mg/ml. The highest emulsifying activity (E(24)) has been observed with vegetable oils, toluene, kerosene, isooctane, cyclohexane, hexane, diesel oil and hexadecane as compared to mineral oil and oleic acid. The biosurfactant also showed good stability during exposure to 100 degrees C for different periods of time (10 to 60 min), to high salinity (30% of NaCl, KCl and NaHCO(3)), and to a wide range of pH values (1-10). The biosurfactant purified by gel filtration chromatography is a glycolipid, with lipid portion containing 16.03% (9Z)-octadec-9-enoic acid, 14.92% hexadecanoic acid, and 9.63% (E) octadec-9-enoic acid and the carbohydrate portion containing mannose (35.29%), xylose (41.99%), arabinose (17.47%), and glucose (5.25%).

  11. Isolation and identification of a novel, lipase-producing bacterium, Pseudomnas aeruginosa KM110

    PubMed Central

    Mobarak-Qamsari, E; Kasra-Kermanshahi, R; Moosavi-nejad, Z

    2011-01-01

    Background and Objectives Lipases are particularly important due to the fact that they specifically hydrolyze acyl glycerol, oils and greases, which is of great interest for different industrial applications. Materialst and Methods In this study, several lipase-producing bacteria were isolated from wastewater of an oil processing plant. The strain possessing the highest lipase activity was identified both biochemically and sequencing of 16S rRNA gene. Then we increase lipase activity by improving conditions of production medium. Also, lipase from this strain was preliminarily characterized for use in industrial application. Results The 16S rRNA sequensing revealed it as a new strain of Pseudomonas aeruginosa and the type strain was KM110. An overall 3-fold enhanced lipase production (0.76 U mL−1) was achieved after improving conditions of production medium. The olive oil and peptone was found to be the most suitable substrate for maximum enzyme production. Also the enzyme exhibited maximum lipolytic activity at 45°C where it was also stably maintained. At pH 8.0, the lipase had the highest stability but no activity. It was active over a pH range of 7.0–10.0. The lipase activity was inhibited by Zn2+ & Cu2+ (32 and 27%, respectively) at 1mM. The enzyme lost 29% of its initial activity in 1.0% SDS concentration, whereas, Triton X-100, Tween-80 & DMSO did not significantly inhibit lipase activity. Conclusions Based on the findings of present study, lipase of P. aeruginosa KM110 is a potential alkaline lipase and a candidate for industrial applications such as detergent, leather and fine chemical industries. PMID:22347589

  12. Force produced by isolated sarcomeres and half-sarcomeres after an imposed stretch.

    PubMed

    Rassier, Dilson E; Pavlov, Ivan

    2012-01-01

    When a stretch is imposed to activated muscles, there is a residual force enhancement that persists after the stretch; the force is higher than that produced during an isometric contraction in the corresponding length. The mechanisms behind the force enhancement remain elusive, and there is disagreement if it represents a sarcomeric property, or if it is associated with length nonuniformities among sarcomeres and half-sarcomeres. The purpose of this study was to investigate the effects of stretch on single sarcomeres and myofibrils with predetermined numbers of sarcomeres (n = 2, 3. . . , 8) isolated from the rabbit psoas muscle. Sarcomeres were attached between two precalibrated microneedles for force measurements, and images of the preparations were projected onto a linear photodiode array for measurements of half-sarcomere length (SL). Fully activated sarcomeres were subjected to a stretch (5-10% of initial SL, at a speed of 0.3 μm·s(-1)·SL(-1)) after which they were maintained isometric for at least 5 s before deactivation. Single sarcomeres showed two patterns: 31 sarcomeres showed a small level of force enhancement after stretch (10.46 ± 0.78%), and 28 sarcomeres did not show force enhancement (-0.54 ± 0.17%). In these preparations, there was not a strong correlation between the force enhancement and half-sarcomere length nonuniformities. When three or more sarcomeres arranged in series were stretched, force enhancement was always observed, and it increased linearly with the degree of half-sarcomere length nonuniformities. The results show that the residual force enhancement has two mechanisms: 1) stretch-induced changes in sarcomeric structure(s); we suggest that titin is responsible for this component, and 2) stretch-induced nonuniformities of half-sarcomere lengths, which significantly increases the level of force enhancement.

  13. Gordonibacter urolithinfaciens sp. nov., a urolithin-producing bacterium isolated from the human gut.

    PubMed

    Selma, María V; Tomás-Barberán, Francisco A; Beltrán, David; García-Villalba, Rocio; Espín, Juan C

    2014-07-01

    Urolithins are dibenzopyranone metabolites that exert anti-inflammatory activity in vivo and are produced by the gut microbiota from the dietary polyphenols ellagic acid (EA) and ellagitannins. However, the bacteria involved in this process remain unknown. We report here a novel bacterium, strain CEBAS 1/15P(T), capable of metabolizing EA to urolithins, that was isolated from healthy human faeces and characterized by determining phenotypic, biochemical and molecular methods. The strain was related to Gordonibacter pamelaeae 7-10-1-b(T), the type and only reported strain of the only species of the genus Gordonibacter, with about 97% 16S rRNA gene sequence similarity; they were both obligately anaerobic, non-spore-forming, Gram-stain-positive, short-rods/coccobacilli and metabolized only small numbers of carbon sources. L-Fucose, D-fructose, turanose, D-galacturonic acid and α-ketobutyric acid were metabolized by strain CEBAS 1/15P(T), while G. pamelaeae was negative for metabolism of these compounds. The whole-cell fatty acids consisted predominantly of saturated fatty acids (70%); strain CEBAS 1/15P(T) differed significantly from G. pamelaeae in the major fatty acid, which was C18 : 1ω9c, while anteiso-C15 : 0 was the major component for G. pamelaeae. The presence of a number of different fatty acid peaks, especially C19 : 0 cyclo and C18 : 1ω6c, was also indicative of distinct species. Six glycolipids (GL1-6) were recognized, while, in G. pamelaeae, only four glycolipids were described. On the basis of these data, the novel species Gordonibacter urolithinfaciens sp. nov. is described, with strain CEBAS 1/15P(T) ( = DSM 27213(T) = CCUG 64261(T)) as the type strain.

  14. Pseudomonas sagittaria sp. nov., a siderophore-producing bacterium isolated from oil-contaminated soil.

    PubMed

    Lin, Shih-Yao; Hameed, Asif; Liu, You-Cheng; Hsu, Yi-Han; Lai, Wei-An; Chen, Wen-Ming; Shen, Fo-Ting; Young, Chiu-Chung

    2013-07-01

    An aerobic, Gram-stain-negative, rod-shaped bacterium with a single polar flagellum, designated CC-OPY-1(T), was isolated from an oil-contaminated site in Taiwan. CC-OPY-1(T) produces siderophores, and can grow at temperatures of 25-37 °C and pH 5.0-9.0 and tolerate <5 % (w/v) NaCl. The 16S rRNA gene sequence analysis of CC-OPY-1(T) showed high pairwise sequence similarity to Pseudomonas alcaligenes BCRC 11893(T) (97.1 %), Pseudomonas. alcaliphila DSM 17744(T) (97.1 %), Pseudomonas tuomuerensis JCM 14085(T) (97.1 %), Pseudomonas toyotomiensis JCM 15604(T) (96.9 %) and lower sequence similarity to remaining species of the genus Pseudomonas. The phylogenetic trees reconstructed based on gyrB and rpoB gene sequences supported the classification of CC-OPY-1(T) as a novel member of the genus Pseudomonas. The predominant quinone system of strain CC-OPY-1T was ubiquinone (Q-9) and the DNA G+C content was 68.4 ± 0.3 mol%. The major fatty acids were C12 : 0, C16 : 0, C17 : 0 cyclo and summed features 3 and 8 consisting of C16 : 1ω7c/C16 : 1ω6c and C18 : 1ω7c/C18 : 1ω6c, respectively. The major polar lipids were phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylcholine (PC) and two unknown phospholipids (PL1-2). Due to distinct phylogenetic, phenotypic and chemotaxonomic features, CC-OPY-1(T) is proposed to represent a novel species within the genus Pseudomonas for which the name Pseudomonas sagittaria sp. nov. is proposed. The type strain is CC-OPY-1(T) ( = BCRC 80399(T) = JCM 18195(T)).

  15. Flavobacterium faecale sp. nov., an agarase-producing species isolated from stools of Antarctic penguins.

    PubMed

    Kim, Jin Ho; Choi, Bo Hyun; Jo, Minho; Kim, Sun Chang; Lee, Pyung Cheon

    2014-08-01

    Taxonomic studies were performed on an agarase-producing strain, designated WV33(T), isolated from faeces of Antarctic penguins. Cells of strain WV33(T) were Gram-staining-negative, strictly aerobic, orange and rod-shaped. Strain WV33(T) displayed agarase activity and was able to utilize galactose as a sole carbon source. 16S rRNA gene sequence analysis revealed that strain WV33(T) was closely related to Flavobacterium algicola TC2(T) (98.0% similarity), F. frigidarium ATCC 700810(T) (96.9%) and F. frigoris LMG 21922(T) (96.1%). The predominant cellular fatty acids were iso-C(15 : 1) G, iso-C(15 : 0), C(15 : 0), C(16 : 0) and summed feature 3 (comprising iso-C(15 : 0) 2-OH and/or C(16 : 1)ω7c). Menaquinone 6 (MK-6) was the sole quinone identified, and the major pigment was zeaxanthin. The major polar lipid was phosphatidylethanolamine. DNA-DNA relatedness of strain WV33(T) with respect to its closest phylogenetic neighbours was 25% for F. algicola NBRC 102673(T), 23% for F. frigidarium DSM 17623(T) and 21% for F. frigoris DSM 15719(T). The DNA G+C content of strain WV33(T) was 37±0.6 mol%. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain WV33(T) is concluded to represent a novel species of the genus Flavobacterium, for which the name Flavobacterium faecale sp. nov. is proposed. The type strain is WV33(T) ( = KCTC 32457(T) = CECT 8384(T)).

  16. Hydrogenoanaerobacterium saccharovorans gen. nov., sp. nov., isolated from H2-producing UASB granules.

    PubMed

    Song, Lei; Dong, Xiuzhu

    2009-02-01

    Two strictly anaerobic bacterial strains, designated SW512(T) and W72, were isolated from a laboratory-scale H(2)-producing up-flow anaerobic sludge blanket (UASB) reactor. Cells were Gram-stain-negative, non-motile and 0.3-0.4x2.0-14.5 mum; they did not form spores. Both strains grew at 24-45 degrees C (no growth at or=46 degrees C), with optimum growth at 37 degrees C. The pH range for growth was 4.5-9.0 (no growth at pHor=9.3), with optimum growth at pH 6.5-7.0. Several kinds of mono-, di- and oligosaccharides supported growth. The main end products of glucose fermentation were ethanol, acetate, hydrogen and carbon dioxide (according to the equation 1 mol glucose-->1.1 mol acetate+0.6 mol ethanol+2.6 mol H(2)+1.6 mol CO(2)). The DNA G+C contents of strains SW512(T) and W72 were 41.9+/-0.5 and 42.8+/-0.4 mol% (T(m) method), respectively. Phylogenetic analysis based on 16S rRNA gene sequence similarities indicated that the two strains represent a new phyletic sublineage within the family 'Ruminococcaceae', with <91.3 % 16S rRNA gene sequence similarity to recognized species. On the basis of the polyphasic evidence in this study, it is proposed that the two strains represent a novel species in a new genus, for which the name Hydrogenoanaerobacterium saccharovorans gen. nov., sp. nov. is proposed; the type strain of the type species is SW512(T) (=AS 1.5070(T)=JCM 14861(T)).

  17. Characterization and identification of enzyme-producing microflora isolated from the gut of sea cucumber Apostichopus japonicus

    NASA Astrophysics Data System (ADS)

    Li, Fenghui; Gao, Fei; Tan, Jie; Fan, Chaojing; Sun, Huiling; Yan, Jingping; Chen, Siqing; Wang, Xiaojun

    2016-01-01

    Gut microorganisms play an important role in the digestion of their host animals. The purpose of this research was to isolate and assess the enzyme-producing microbes from the Apostichopus japonicus gut. Thirty-nine strains that can produce at least one of the three digestive enzymes (protease, amylase, and cellulase) were qualitatively screened based on their extracellular enzyme-producing abilities. The enzyme-producing strains clustered into eight groups at the genetic similarity level of 100% by analyzing the restriction patterns of 16S rDNA amplified with Mbo I. Phylogenetic analysis revealed that 37 strains belonged to the genus Bacillus and two were members of the genus Virgibacillus. Enzyme-producing capability results indicate that the main enzyme-producing microflora in the A. japonicus gut was Bacillus, which can produce protease, amylase, and cellulase. Virgibacillus, however, can only produce protease. The high enzyme-producing capability of the isolates suggests that the gut microbiota play an important role in the sea cucumber digestive process.

  18. Clonal relatedness and biofilm formation of OXA-23-producing carbapenem resistant Acinetobacter baumannii isolates from hospital environment.

    PubMed

    Aliramezani, Amir; Douraghi, Masoumeh; Hajihasani, Azade; Mohammadzadeh, Mona; Rahbar, Mohammad

    2016-10-01

    Carbapenem-resistant Acinetobacter baumannii (CRAB) is a serious threat for hospitalized patients and it can survive for long periods in hospital settings, particularly on inanimate surfaces. The environment occupied by these resistant and resilient isolates may act as a reservoir for cross-colonization and outbreaks. Here, we aimed to determine the distribution of CRAB in the hospital environment and to characterize their clonal relatedness, susceptibility profile, carriage of blaOXA genes, and biofilm formation. A total of 1080 samples were collected from various environmental surfaces and equipment of two referral hospitals in Tehran, Iran. The A. baumannii isolates were subjected to gyrB multiplex PCR, antibiotic susceptibility testing, biofilm formation assay, pulsed field gel electrophoresis (PFGE), and multiplex PCR for blaOXA-58, blaOXA-24, and blaOXA-23 genes. Eighteen Acinetobacter spp. were isolated; 8 were identified as A. baumannii and 10 as A. lwoffii. Five of A. baumannii isolates were CRAB and exhibited the multidrug-resistant (MDR) phenotype as well. All CRAB isolates produced biofilm, albeit with different levels. Four of CRAB isolates harbored the blaOXA-23. The CRAB isolates were clustered into 3 distinct pulsotypes (PTs). The CRAB isolates belonging to PT1 were detected in two geographically distinct hospitals whereas those belonging to PT3 were found in two different units of same hospital. This study revealed the presence of clonally related OXA-23-producing CRAB in high risk units of referral hospitals as inter- or intra-hospital dissemination. The distribution of multiresistant A. baumannii on several surfaces and areas may increase the risk of transmission of resistant isolates to vulnerable patients.

  19. Phenotypic Characteristics Associated with Virulence of Clinical Isolates from the Sporothrix Complex

    PubMed Central

    Almeida-Paes, Rodrigo; de Oliveira, Luã Cardoso; Oliveira, Manoel Marques Evangelista; Gutierrez-Galhardo, Maria Clara; Nosanchuk, Joshua Daniel; Zancopé-Oliveira, Rosely Maria

    2015-01-01

    The Sporothrix complex members cause sporotrichosis, a subcutaneous mycosis with a wide spectrum of clinical manifestations. Several specific phenotypic characteristics are associated with virulence in many fungi, but studies in this field involving the Sporothrix complex species are scarce. Melanization, thermotolerance, and production of proteases, catalase, and urease were investigated in 61 S. brasiliensis, one S. globosa, and 10 S. schenckii strains. The S. brasiliensis strains showed a higher expression of melanin and urease compared with S. schenckii. These two species, however, presented similar thermotolerances. Our S. globosa strain had low expression of all studied virulence factors. The relationship between these phenotypes and clinical aspects of sporotrichosis was also evaluated. Strains isolated from patients with spontaneous regression of infection were heavily melanized and produced high urease levels. Melanin was also related to dissemination of internal organs and protease production was associated with HIV-coinfection. A murine sporotrichosis model showed that a S. brasiliensis strain with high expression of virulence factors was able to disseminate and yield a high fungal burden in comparison with a control S. schenckii strain. Our results show that virulence-related phenotypes are variably expressed within the Sporothrix complex species and might be involved in clinical aspects of sporotrichosis. PMID:25961005

  20. Insertion Sequence IS26 Reorganizes Plasmids in Clinically Isolated Multidrug-Resistant Bacteria by Replicative Transposition

    PubMed Central

    He, Susu; Hickman, Alison Burgess; Varani, Alessandro M.; Siguier, Patricia; Chandler, Michael; Dekker, John P.

    2015-01-01

    ABSTRACT Carbapenemase-producing Enterobacteriaceae (CPE), which are resistant to most or all known antibiotics, constitute a global threat to public health. Transposable elements are often associated with antibiotic resistance determinants, suggesting a role in the emergence of resistance. One insertion sequence, IS26, is frequently associated with resistance determinants, but its role remains unclear. We have analyzed the genomic contexts of 70 IS26 copies in several clinical and surveillance CPE isolates from the National Institutes of Health Clinical Center. We used target site duplications and their patterns as guides and found that a large fraction of plasmid reorganizations result from IS26 replicative transpositions, including replicon fusions, DNA inversions, and deletions. Replicative transposition could also be inferred for transposon Tn4401, which harbors the carbapenemase blaKPC gene. Thus, replicative transposition is important in the ongoing reorganization of plasmids carrying multidrug-resistant determinants, an observation that carries substantial clinical and epidemiological implications for understanding how such extreme drug resistance phenotypes evolve. PMID:26060276

  1. [In vitro antibacterial activities of cefteram and other beta-lactam agents against recent clinical isolates].

    PubMed

    Yamaguchi, K; Ohno, A; Takahashi, S; Hayashi, M; Yamanaka, K; Hirakata, Y; Mitsuyama, J

    1998-01-01

    In vitro antibacterial activity of the third-generation oral cephem cefteram (CFTM)--ten years after its first use in the clinical setting--against recent clinical isolates was evaluated and compared with those of other oral cephems. A total of 851 clinical isolates belonging to 13 species used in this study were collected from five medical institutions across Japan during 1996. CFTM showed excellent antibacterial activity against methicillin-susceptible S. aureus and S. pyogenes, equivalent to those of other third-generation oral cephems, except cefixime. Of the S. pneumoniae strains, a high proportion, 34.1%, were penicillin-resistant strains (PRSP), with MIC values of 2.0 micrograms/ml or above, but the MIC50 of CFTM against PRSP was 1.0 microgram/ml. CFTM and the other third-generation oral cephems showed potent antibacterial activity against E. coli, K. pneumoniae, and P. mirabilis. A few strains of E. coli, however, were highly resistant to third-generation oral cephems; that might include extended-spectrum beta-lactamase producing strains. MIC values against P. vulgaris varied significantly, depending on whether they were determined by the broth micro-dilution method or the agar dilution method; growth was observed at high concentrations in the broth micro-dilution method, in which the skip phenomenon was demonstrated, but not in the agar dilution method. The reason for this discrepancy is unknown. Most strains of S. marcescens, C. freundii, and E. cloacae demonstrated resistance to CFTM and the other third-generation oral cephems. CFTM and the other third-generation oral cephems showed excellent antibacterial activities against M. (B.) catarrhalis, N. gonorrhoeae, and H. influenzae, including ampicillin-resistant strains.

  2. Rohitukine, a chromone alkaloid and a precursor of flavopiridol, is