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Sample records for stenotrophomonas maltophilia cgmcc

  1. Genetic Manipulation of Stenotrophomonas maltophilia.

    PubMed

    Welker, Elliott; Domfeh, Yayra; Tyagi, Deepti; Sinha, Sanjivni; Fisher, Nathan

    2015-01-01

    Stenotrophomonas maltophilia is a Gram-negative, aerobic, motile, environmental bacterium that is emerging as an important nosocomial pathogen with high rates of attributable mortality in severely ill patients. S. maltophilia is of particular concern to patients suffering from cystic fibrosis (CF) as it has been shown to colonize airway epithelial and establish a chronic infection. Here we describe several molecular techniques for the genetic manipulation of this bacterium, including DNA extraction, RNA extraction, conjugation of plasmids from Escherichia coli and allelic exchange. PMID:26344220

  2. Genetic Manipulation of Stenotrophomonas maltophilia

    PubMed Central

    Welker, Elliott; Domfeh, Yayra; Tyagi, Deepti; Sinha, Sanjivni; Fisher, Nathan

    2015-01-01

    Stenotrophomonas maltophilia is a Gram-negative, aerobic, motile, environmental bacterium that is emerging as an important nosocomial pathogen (Brooke, 2012; Looney, Narita, & Mühlemann, 2009) with high rates of attributable mortality in severely ill patients (Falagas et al., 2009; Paez & Costa, 2008; Sattler, Mason, & Kaplan, 2000; Senol, DesJardin, Stark, Barefoot, & Snydman, 2002; Weber et al., 2007). S. maltophilia is of particular concern to patients suffering from cystic fibrosis (CF) as it has been shown to colonize airway epithelial and establish a chronic infection (Goncalves-Vidigal et al., 2011). Here we describe several molecular techniques for the genetic manipulation of this bacterium, including DNA extraction, RNA extraction, conjugation of plasmids from E. coli and allelic exchange. PMID:26344220

  3. Stenotrophomonas maltophilia: rare cause of meningitis.

    PubMed

    Correia, Cátia Rodrigues; Ferreira, Sara Tavares; Nunes, Paula

    2014-08-01

    Stenotrophomonas maltophilia is a Gram-negative bacillus, which is an extremely rare cause of meningitis. To our knowledge, there are only five previous pediatrics cases. Here, we describe the case of a 4-year-old boy who developed meningitis associated with this organism, after several neurosurgical procedures and previous treatment with a broad-spectrum antibiotic. He was treated successfully with a combination of trimethoprim-sulfamethoxazole, ceftazidime and levofloxacin. Stenotrophomonas maltophilia should be considered as a potential cause of meningitis, especially among severely debilitated or immunosuppressed patients. Antimicrobial therapy is complicated by the high resistance of the organism to multiple antibiotics. PMID:25252064

  4. Stenotrophomonas maltophilia: an Emerging Global Opportunistic Pathogen

    PubMed Central

    2012-01-01

    Summary: Stenotrophomonas maltophilia is an emerging multidrug-resistant global opportunistic pathogen. The increasing incidence of nosocomial and community-acquired S. maltophilia infections is of particular concern for immunocompromised individuals, as this bacterial pathogen is associated with a significant fatality/case ratio. S. maltophilia is an environmental bacterium found in aqueous habitats, including plant rhizospheres, animals, foods, and water sources. Infections of S. maltophilia can occur in a range of organs and tissues; the organism is commonly found in respiratory tract infections. This review summarizes the current literature and presents S. maltophilia as an organism with various molecular mechanisms used for colonization and infection. S. maltophilia can be recovered from polymicrobial infections, most notably from the respiratory tract of cystic fibrosis patients, as a cocolonizer with Pseudomonas aeruginosa. Recent evidence of cell-cell communication between these pathogens has implications for the development of novel pharmacological therapies. Animal models of S. maltophilia infection have provided useful information about the type of host immune response induced by this opportunistic pathogen. Current and emerging treatments for patients infected with S. maltophilia are discussed. PMID:22232370

  5. Stenotrophomonas maltophilia: Complicating treatment of ESBL UTI.

    PubMed

    Kumar, Simit; Bandyopadhyay, Maitreyi; Chatterjee, Mitali; Banerjee, Parthajit; Poddar, Sumon; Banerjee, Debarati

    2015-01-01

    Stenotrophomonas maltophilia (S. maltophilia) is a gram-negative bacillus emerging as an opportunistic, nosocomial pathogen associated with a high mortality rate. The organism has been shown to survive several biocides used in the hospital setting. Hospital water sources can serve as a reservoir for S. maltophilia. The transmission of S. maltophilia to susceptible individuals may occur through direct contact with the source or through the hands of health care personnel. S. maltophilia is usually resistant to third-generation cephalosporins, aminoglycosides and antipseudomonal penicillins. These microorganisms are intrinsically resistant to carbapenems, and exposure to these agents has been linked to selection of S. maltophilia. There have also been reports of the organism developing resistance to trimethoprim-sulfamethoxazole (TMP-SMX), which was initially considered as the drug of choice for S. maltophillia infections. We describe a case of nosocomial urinary tract infection (UTI) due to S. maltophilia in a diabetic patient, which the patient developed during treatment with meropenem for UTI due to Klebsiella pneumonia that was resistant to TMP-SMX. PMID:25789262

  6. Stenotrophomonas maltophilia: Complicating treatment of ESBL UTI

    PubMed Central

    Kumar, Simit; Bandyopadhyay, Maitreyi; Chatterjee, Mitali; Banerjee, Parthajit; Poddar, Sumon; Banerjee, Debarati

    2015-01-01

    Stenotrophomonas maltophilia (S. maltophilia) is a gram-negative bacillus emerging as an opportunistic, nosocomial pathogen associated with a high mortality rate. The organism has been shown to survive several biocides used in the hospital setting. Hospital water sources can serve as a reservoir for S. maltophilia. The transmission of S. maltophilia to susceptible individuals may occur through direct contact with the source or through the hands of health care personnel. S. maltophilia is usually resistant to third-generation cephalosporins, aminoglycosides and antipseudomonal penicillins. These microorganisms are intrinsically resistant to carbapenems, and exposure to these agents has been linked to selection of S. maltophilia. There have also been reports of the organism developing resistance to trimethoprim–sulfamethoxazole (TMP–SMX), which was initially considered as the drug of choice for S. maltophillia infections. We describe a case of nosocomial urinary tract infection (UTI) due to S. maltophilia in a diabetic patient, which the patient developed during treatment with meropenem for UTI due to Klebsiella pneumonia that was resistant to TMP–SMX. PMID:25789262

  7. Stenotrophomonas maltophilia: an emerging pathogen in dialysis units.

    PubMed

    De Mauri, Andreana; Torreggiani, Massimo; Chiarinotti, Doriana; Andreoni, Stefano; Molinari, Gianlorenzo; De Leo, Martino

    2014-11-01

    Infection is an important cause of morbidity and mortality among patients with end stage renal disease. Stenotrophomonas maltophilia is an unusual yet emerging pathogen in dialysis units. We performed a systematic PubMed/Medline and Scopus review of peer-reviewed English papers on S. maltophilia infections among patients undergoing chronic dialysis, with regard to vascular accesses, systemic infections and environment contaminations. Moreover, we suggest a treatment algorithm to preserve the patient and the permanent dialysis catheters. PMID:25102909

  8. Community-acquired infection due to Stenotrophomonas maltophilia: a rare cause of septic arthritis.

    PubMed

    Aydemir, Cumhur; Aktaş, Elif; Eldeş, Nilüfer; Kutsal, Ebru; Demirel, Fatma; Ege, Ahmet

    2008-01-01

    Stenotrophomonas maltophilia is an important nosocomial pathogen in hospitalized patients, particularly those with prior broad-spectrum antibacterial therapy. The microorganism mainly infects severely ill, debilitated patients and is most frequent in immunocompromised hosts. A prominent feature of this organism is its resistance to multiple antibiotics including beta-lactam agents, carbapenems and aminoglycosides. Community-acquired infection with Stenotrophomonas maltophilia is reported rarely. This is the first report of a child patient diagnosed with septic arthritis due to Stenotrophomonas maltophilia. PMID:18365601

  9. [Clinical strains isolation and antibiotic susceptibility of Stenotrophomonas maltophilia].

    PubMed

    Hankiewicz-Ziołkowska, Karolina; Mikucka, Agnieszka; Gospodarek, Eugenia

    2010-01-01

    Stenotrophomonas maltophilia is an opportunistic Gram-negative bacillus which is becoming increasingly recognized as an important nosocomial pathogen especially in debilitated or immune suppressed patients. S. maltophilia is found in a wide variety of environments. It has been isolated from a number of water sources, soil, variety of plants and food sources. S. maltophilia can form biofilm on synthetic materials for temporary or permanent implantation, i.e. central venous catheters, urinary catheters and prosthetic heart valves. In hospital the organism has been isolated from wet environments such as antiseptic fluids containing chlorhexidine, respiratory therapy equipment and air nebulizers. Little is known of the virulence factors of S. maltophilia. S. maltophilia is naturally resistant to many currently available broad-spectrum antimicrobial agents, including carbapenems. This study was carried out with the objective of evaluating clinical strains isolation and antibiotic susceptibility of S. maltophilia. A total of 80 clinical isolates of S. maltophilia were collected from individual patients, hospitalized at A. Jurasz University Hospital in Bydgoszcz, Poland. To identify S. maltophilia strains and receive biochemical profiles API 20 NE tests (bio Mérieux) ATB Expression computer system (bio Mérieux) with database V 2.4.7. were used. Antimicrobial agents susceptibility was evaluated for 19 different agents. For 18 out of 19 antimicrobial agent Etests (AB Biodisc) were used. For levofloxacine disc diffusion method was used. Most of analyzed strains were isolated from broncho-alveolar lavage (37.5%) from patients hospitalized in Intensive Care Unit (48.8%). 95.7% of isolated strains were susceptible to levofloxacine and 71,3% to trimethoprim/sulfametholxazole. 48 (60.0%) of S. maltophilia strains were identified as multi-drug resistant. PMID:20873485

  10. Haemorrhagic pneumonia caused by Stenotrophomonas maltophilia in two newborns.

    PubMed

    Guzoglu, Nilufer; Demirkol, Fatma Nur; Aliefendioglu, Didem

    2015-05-01

    Invasive procedures and antibiotic treatment increase the risk of nosocomial infections in neonatal intensive care units. Early identification and appropriate treatment is important. Herein we report two cases of massive hemorrhagic pneumonia caused by Stenotrophomonas maltophilia. The first case was diagnosed with congenital pneumonia; a chest tube was inserted because of pneumothorax on the third day of life. The second case had been referred with respiratory distress syndrome, and bilateral pneumothorax was present on admission. Upon follow up, the cases' clinical condition worsened; acute respiratory distress syndrome and massive pulmonary haemorrhage developed. After Stenotrophomonas maltophilia was isolated in blood cultures, the cases were treated successfully using a combination of trimethoprim/sulfamethoxazole and fluoroquinolone. PMID:25989175

  11. Microbiological and Clinical Aspects of Infection Associated with Stenotrophomonas maltophilia

    PubMed Central

    Denton, Miles; Kerr, Kevin G.

    1998-01-01

    The gram-negative bacterium Stenotrophomonas maltophilia is increasingly recognized as an important cause of nosocomial infection. Infection occurs principally, but not exclusively, in debilitated and immunosuppressed individuals. Management of S. maltophilia-associated infection is problematic because many strains of the bacterium manifest resistance to multiple antibiotics. These difficulties are compounded by methodological problems in in vitro susceptibility testing for which there are, as yet, no formal guidelines. Despite its acknowledged importance as a nosocomial pathogen, little is known of the epidemiology of S. maltophilia, and although it is considered an environmental bacterium, its sources and reservoirs are often not readily apparent. Molecular typing systems may contribute to our knowledge of the epidemiology of S. maltophilia infection, thus allowing the development of strategies to interrupt the transmission of the bacterium in the hospital setting. Even less is known of pathogenic mechanisms and putative virulence factors involved in the natural history of S. maltophilia infection and this, coupled with difficulties in distinguishing colonization from true infection, has fostered the view that the bacterium is essentially nonpathogenic. This article aims to review the current taxonomic status of S. maltophilia, and it discusses the laboratory identification of the bacterium. The epidemiology of the organism is considered with particular reference to nosocomial outbreaks, several of which have been investigated by molecular typing techniques. Risk factors for acquisition of the bacterium are also reviewed, and the ever-expanding spectrum of clinical syndromes associated with S. maltophilia is surveyed. Antimicrobial resistance mechanisms, pitfalls in in vitro susceptibility testing, and therapy of S. maltophilia infections are also discussed. PMID:9457429

  12. Antibiotic resistance in the opportunistic pathogen Stenotrophomonas maltophilia

    PubMed Central

    Sánchez, María B.

    2015-01-01

    Stenotrophomonas maltophilia is an environmental bacterium found in the soil, associated with plants and animals, and in aquatic environments. It is also an opportunistic pathogen now causing an increasing number of nosocomial infections. The treatment of S. maltophilia is quite difficult given its intrinsic resistance to a number of antibiotics, and because it is able to acquire new resistances via horizontal gene transfer and mutations. Certainly, strains resistant to quinolones, cotrimoxale and/or cephalosporins—antibiotics commonly used to treat S. maltophilia infections—have emerged. The increasing number of available S. maltophilia genomes has allowed the identification and annotation of a large number of antimicrobial resistance genes. Most encode inactivating enzymes and efflux pumps, but information on their role in intrinsic and acquired resistance is limited. Non-typical antibiotic resistance mechanisms that also form part of the intrinsic resistome have been identified via mutant library screening. These include non-typical antibiotic resistance genes, such as bacterial metabolism genes, and non-inheritable resistant phenotypes, such as biofilm formation and persistence. Their relationships with resistance are complex and require further study. PMID:26175724

  13. Antibiotic resistance in the opportunistic pathogen Stenotrophomonas maltophilia.

    PubMed

    Sánchez, María B

    2015-01-01

    Stenotrophomonas maltophilia is an environmental bacterium found in the soil, associated with plants and animals, and in aquatic environments. It is also an opportunistic pathogen now causing an increasing number of nosocomial infections. The treatment of S. maltophilia is quite difficult given its intrinsic resistance to a number of antibiotics, and because it is able to acquire new resistances via horizontal gene transfer and mutations. Certainly, strains resistant to quinolones, cotrimoxale and/or cephalosporins-antibiotics commonly used to treat S. maltophilia infections-have emerged. The increasing number of available S. maltophilia genomes has allowed the identification and annotation of a large number of antimicrobial resistance genes. Most encode inactivating enzymes and efflux pumps, but information on their role in intrinsic and acquired resistance is limited. Non-typical antibiotic resistance mechanisms that also form part of the intrinsic resistome have been identified via mutant library screening. These include non-typical antibiotic resistance genes, such as bacterial metabolism genes, and non-inheritable resistant phenotypes, such as biofilm formation and persistence. Their relationships with resistance are complex and require further study. PMID:26175724

  14. Antimicrobial Susceptibilities of Unique Stenotrophomonas maltophilia Clinical Strains

    PubMed Central

    Valdezate, Sylvia; Vindel, Ana; Loza, Elena; Baquero, Fernando; Cantón, Rafael

    2001-01-01

    Susceptibility to 41 antimicrobials was studied with 99 Stenotrophomonas maltophilia strains, and different pulsed-field gel electrophoresis profiles were identified among 130 prospectively collected isolates. Moxalactam, doxycycline, minocycline, and clinafloxacin displayed the highest activity (≥98% susceptibility). Ticarcillin resistance (75%) was reverted by clavulanate in 25% of strains. Trimethoprim-sulfamethoxazole resistance was 26.2% (≥4 [trimethoprim]/76 [sulfamethoxazole] μg/ml) and dropped to 11.1% when an 8/152-μg/ml breakpoint was applied based on its bimodal MIC distribution. Resistance was lower when unique strains were considered, because clonal organisms contribute to resistance. PMID:11302834

  15. PCR-based rapid genotyping of Stenotrophomonas maltophilia isolates

    PubMed Central

    Roscetto, Emanuela; Rocco, Francesco; Carlomagno, M Stella; Casalino, Mariassunta; Colonna, Bianca; Zarrilli, Raffaele; Di Nocera, Pier Paolo

    2008-01-01

    Background All bacterial genomes contain repetitive sequences which are members of specific DNA families. Such repeats may occur as single units, or found clustered in multiple copies in a head-to-tail configuration at specific loci. The number of clustered units per locus is a strain-defining parameter. Assessing the length variability of clusters of repeats is a versatile typing methodology known as multilocus variable number of tandem repeat analysis (MLVA). Results Stenotrophomonas maltophilia is an environmental bacterium increasingly involved in nosocomial infections and resistant to most antibiotics. The availability of the whole DNA sequence of the S. maltophilia strain K279a allowed us to set up fast and accurate PCR-based diagnostic protocols based on the measurement of length variations of loci carrying a variable number of short palindromic repeats marking the S. maltophilia genome. On the basis of the amplimers size, it was possible to deduce the number of repeats present at 12 different loci in a collection of S. maltophilia isolates, and therefore label each of them with a digit. PCR-negative regions were labelled 0. Co-amplification of two pairs of loci provided a 4-digit code sufficient for immediate subtyping. By increasing the number of loci analyzed, it should be possible to assign a more specific digit profile to isolates. In general, MLVA data match genotyping data obtained by PFGE (pulsed-field gel electrophoresis). However, some isolates exhibiting the same PCR profiles at all loci display distinct PFGE patterns. Conclusion The utilization of the present protocol allows to type several S. maltophilia isolates in hours. The results are immediately interpretable without the need for sophisticated softwares. The data can be easily reproducible, and compared among different laboratories. PMID:19025624

  16. Multiple degradation pathways of phenanthrene by Stenotrophomonas maltophilia C6.

    PubMed

    Gao, Shumei; Seo, Jong-Su; Wang, Jun; Keum, Young-Soo; Li, Jianqiang; Li, Qing X

    2013-04-01

    Stenotrophomonas maltophilia strain C6, capable of utilizing phenanthrene as a sole source of carbon and energy, was isolated from creosote-contaminated sites at Hilo, Hawaii. Twenty-two metabolites of phenanthrene, covering from dihydrodiol to protocatechuic acid, were isolated and characterized. Phenanthrene was degraded via an initial dioxygenation on 1,2-, 3,4-, and 9,10-C, where the 3,4-dioxygenation and subsequent metabolisms were most dominant. The metabolic pathways were further branched by ortho- and meta-cleavage of phenanthrenediols to produce 1-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, and naphthalene-1,2-dicarboxylic acid. These intermediates were then transformed to naphthalene-1,2-diol. 1-Hydroxy-2-naphthoic acid was also degraded via a direct ring cleavage. Naphthalene-1,2-diol underwent primarily ortho-cleavage to produce trans-2-carboxycinnamic acid and then to form phthalic acid, 4,5-dihydroxyphthalic acid and protocatechuic acid. Accumulation of salicylic acid in prolonged incubation indicated that a limited extent of meta-cleavage of naphthalene-1, 2-diol also occurred. This is the first study of detailed phenanthrene metabolic pathways by Stenotrophomonas maltophilia. PMID:23539472

  17. Multiple degradation pathways of phenanthrene by Stenotrophomonas maltophilia C6

    PubMed Central

    Gao, Shumei; Seo, Jong-Su; Wang, Jun; Keum, Young-Soo; Li, Jianqiang; Li, Qing X.

    2013-01-01

    Stenotrophomonas maltophilia strain C6, capable of utilizing phenanthrene as a sole source of carbon and energy, was isolated from creosote-contaminated sites at Hilo, Hawaii. Twenty-two metabolites of phenanthrene, covering from dihydrodiol to protocatechuic acid, were isolated and characterized. Phenanthrene was degraded via an initial dioxygenation on 1,2-, 3,4-, and 9,10-C, where the 3,4-dioxygenation and subsequent metabolisms were most dominant. The metabolic pathways were further branched by ortho- and meta-cleavage of phenanthrenediols to produce 1-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, and naphthalene-1,2-dicarboxylic acid. These intermediates were then transformed to naphthalene-1,2-diol. 1-Hydroxy-2-naphthoic acid was also degraded via a direct ring cleavage. Naphthalene-1,2-diol underwent primarily ortho-cleavage to produce trans-2-carboxycinnamic acid and then to form phthalic acid, 4,5-dihydroxyphthalic acid and protocatechuic acid. Accumulation of salicylic acid in prolonged incubation indicated that a limited extent of meta-cleavage of naphthalene-1, 2-diol also occurred. This is the first study of detailed phenanthrene metabolic pathways by Stenotrophomonas maltophilia. PMID:23539472

  18. Biofilm compared to conventional antimicrobial susceptibility of Stenotrophomonas maltophilia Isolates from cystic fibrosis patients.

    PubMed

    Wu, Kitty; Yau, Yvonne C W; Matukas, Larissa; Waters, Valerie

    2013-03-01

    Stenotrophomonas maltophilia is a multidrug-resistant organism increasingly isolated from the lungs of cystic fibrosis (CF) patients. One hundred twenty-five S. maltophilia isolates from 85 CF patients underwent planktonic and biofilm susceptibility testing against 9 different antibiotics, alone and in double antibiotic combinations. When S. maltophilia isolates were grown as a biofilm, 4 of the 10 most effective antibiotic combinations included high-dose levofloxacin and 7 of the 10 combinations included colistin at doses achievable by aerosolization. PMID:23295930

  19. The efflux pump SmeDEF contributes to trimethoprim-sulfamethoxazole resistance in Stenotrophomonas maltophilia.

    PubMed

    Sánchez, María Blanca; Martínez, José Luis

    2015-07-01

    Trimethoprim-sulfamethoxazole (co-trimoxazole) is one of the antimicrobials of choice for the treatment of Stenotrophomonas maltophilia infections. The analysis of mutants either lacking or overexpressing the efflux pump SmeDEF shows that this efflux pump contributes to intrinsic and acquired co-trimoxazole resistance in S. maltophilia. Since SmeDEF can extrude a variety of antibiotics, selection with such antimicrobials, including quinolones, might also select for S. maltophilia co-trimoxazole resistance. PMID:25918144

  20. In vitro interaction of Stenotrophomonas maltophilia with human monocyte-derived dendritic cells

    PubMed Central

    Roscetto, Emanuela; Vitiello, Laura; Muoio, Rosa; Soriano, Amata A.; Iula, Vita D.; Vollaro, Antonio; Gregorio, Eliana De; Catania, Maria R.

    2015-01-01

    Stenotrophomonas maltophilia is increasingly identified as an opportunistic pathogen in immunocompromised, cancer and cystic fibrosis (CF) patients. Knowledge on innate immune responses to S. maltophilia and its potential modulation is poor. The present work investigated the ability of 12 clinical S. maltophilia strains (five from CF patients, seven from non-CF patients) and one environmental strain to survive inside human monocyte-derived dendritic cells (DCs). The effects of the bacteria on maturation of and cytokine secretion by DCs were also measured. S. maltophilia strains presented a high degree of heterogeneity in internalization and intracellular replication efficiencies as well as in the ability of S. maltophilia to interfere with normal DCs maturation. By contrast, all S. maltophilia strains were able to activate DCs, as measured by increase in the expression of surface maturation markers and proinflammatory cytokines secretion. PMID:26236302

  1. L-glucitol catabolism in Stenotrophomonas maltophilia Ac.

    PubMed

    Brechtel, Elke; Huwig, Alexander; Giffhorn, Friedrich

    2002-02-01

    The carbohydrate catabolism of the bacterium Stenotrophomonas maltophilia Ac (previously named Pseudomonas sp. strain Ac), which is known to convert the unnatural polyol L-glucitol to D-sorbose during growth on the former as the sole source of carbon and energy, was studied in detail. All enzymes operating in a pathway that channels L-glucitol via D-sorbose into compounds of the intermediary metabolism were demonstrated, and for some prominent reactions the products of conversion were identified. D-Sorbose was converted by C-3 epimerization to D-tagatose, which, in turn, was isomerized to D-galactose. D-Galactose was the initial substrate of the De Ley-Doudoroff pathway, involving reactions of NAD-dependent oxidation of D-galactose to D-galactonate, its dehydration to 2-keto-3-deoxy-D-galactonate, and its phosphorylation to 2-keto-3-deoxy-D-galactonate 6-phosphate. Finally, aldol cleavage yielded pyruvate and D-glycerate 3-phosphate as the central metabolic intermediates. PMID:11823194

  2. Stenotrophomonas, a new bacterial genus for Xanthomonas maltophilia (Hugh 1980) Swings et al. 1983.

    PubMed

    Palleroni, N J; Bradbury, J F

    1993-07-01

    In consideration of the criticisms of the transfer of Pseudomonas maltophilia to the genus Xanthomonas proposed by J. Swings, P. De Vos, M. Van den Mooter, and J. De Ley (Int. J. Syst. Bacteriol. 33:409-413, 1983), a new generic name is created for this taxon. The name Stenotrophomonas is here proposed for the new genus, which includes a single species, Stenotrophomonas maltophilia. This proposal restores the genus Xanthomonas to its former definition (J. Bradbury, p. 199-210, in N. R. Krieg and J. G. Holt, ed., Bergey's Manual of Systematic Bacteriology, 1984) The arguments on which this proposal is based are presented. PMID:8347518

  3. Successful treatment of Stenotrophomonas maltophilia meningitis in a preterm baby boy: a case report

    PubMed Central

    2009-01-01

    Introduction Stenotrophomonas maltophilia is an important cause of hospital acquired infection particularly among severely debilitated and immunosuppressed patients. Case presentation We report a case of S. maltophilia meningitis in a preterm baby boy after a neurosurgical procedure, successfully treated with trimethoprim-sulfamethoxazole and ciprofloxacin. Conclusion This organism should be considered as a potential cause of meningitis and trimethoprim-sulfamethoxazole and ciprofloxacin are a combination that is successful and safe for treating preterm infants. PMID:19830198

  4. A molecular biological protocol to distinguish potentially human pathogenic Stenotrophomonas maltophilia from plant-associated Stenotrophomonas rhizophila.

    PubMed

    Ribbeck-Busch, Kathrin; Roder, Anja; Hasse, Dirk; de Boer, Wietse; Martínez, José Luis; Hagemann, Martin; Berg, Gabriele

    2005-11-01

    In recent years, the importance of the Gram-negative bacterium Stenotrophomonas as an opportunistic pathogen as well as in biotechnology has increased. The aim of the present study was to develop new methods for distinguishing between strains closely related to the potentially human pathogenic Stenotrophomonas maltophilia and those closely related to the plant-associated Stenotrophomonas rhizophila. To accomplish this, 58 strains were characterized by 16S rDNA sequencing and amplified ribosomal DNA restriction analysis (ARDRA), and the occurrence of specific functional genes. Based on 16S rDNA sequences, an ARDRA protocol was developed which allowed differentiation between strains of the S. maltophilia and the S. rhizophila group. As it was known that only salt-treated cells of S. rhizophila were able to synthesize the compatible solute glucosylglycerol (GG), the ggpS gene responsible for GG synthesis was used for differentiation between both species and it was confirmed that it only occurred in S. rhizophila strains. As a further genetic marker the smeD gene, which is part of the genes coding for the multidrug efflux pump SmeDEF from S. maltophilia, was used. Based on the results we propose a combination of fingerprinting techniques using the 16S rDNA and the functional genes ggpS and smeD to distinguish both Stenotrophomonas species. PMID:16232300

  5. Stenotrophomonas maltophilia isolated from the airways of animals with chronic respiratory disease.

    PubMed

    Albini, S; Abril, C; Franchini, M; Hüssy, D; Filioussis, G

    2009-07-01

    Stenotrophomonas maltophilia (S. maltophilia) is a nonfermentative bacterium, which is naturally resistant against a panel of commonly-used antibiotics. It is frequently isolated from humans with chronic respiratory disease, e.g. cystic fibrosis or chronic obstructive pulmonary disease. In veterinary medicine S. maltophilia is perceived to be a mere coloniser. We herewith report 7 strains of S. maltophilia isolated from animals, of which 5 strains were harvested from 3 horses, a dog and a cat with chronic respiratory disease. The dog isolate showed resistance to trimethoprim / sulphamethoxazole, which was confirmed by detection of the sul 1 gene. Analysis with pulsed field gel electrophoresis revealed that 2 horses, which were boarded in the same clinic but two years apart, harboured the same strain of S. maltophilia. This is indicative of a hospital acquired colonisation / infection, which contradicts involvement in the pre-existing chronic disease. PMID:19565454

  6. Persistence and variability of Stenotrophomonas maltophilia in cystic fibrosis patients, Madrid, 1991-1998.

    PubMed Central

    Valdezate, S.; Vindel, A.; Maiz, L.; Baquero, F.; Escobar, H.; Cantón, R.

    2001-01-01

    During 1991 to 1998 at least one Stenotrophomonas maltophilia pulmonary infection was observed in 25 (24%) of 104 cystic fibrosis patients at the same unit of our hospital in Spain. Ribotyping and pulse-field gel electrophoresis (PFGE) characterization of 76 S. maltophilia isolates from these patients indicated an overall clonal incidence of 47.1%, reflecting new strains in 44% of patients with repeated positive cultures for S. maltophilia. Six patients with repeated episodes were persistently colonized (> or = 6 months) with the same strain. S. maltophilia bacterial counts were higher (geometric mean, 2.9 x 10(8) cfu/mL) in patients with repeated episodes than in those with a single episode (8.4 x 10(4) cfu/mL, p < 0.01). Single episodes of S. maltophilia occurred in patients < 10 years of age (43% [6/14]), whereas chronic colonization occurred more frequently in older patients (> 16 years of age). PMID:11266301

  7. Stenotrophomonas maltophilia in cystic fibrosis: incidence and prevalence.

    PubMed

    Demko, C A; Stern, R C; Doershuk, C F

    1998-05-01

    Stenotrophomonas maltophilia (SM) was recovered from 211 of 773 cystic fibrosis (CF) patients followed for at least one year, and seen between 1982 and 1994. Yearly prevalence (5.6% to 8.7%) and incidence rates (1.6% to 5.7%) showed no trends. SM persistence varied greatly and was unlike that of Pseudomonas aeruginosa. Fifty percent of SM-positive patients had only one positive culture and only 24 (11%) remained chronically infected. Although SM-positive patients were more likely to be hospitalized than SM-negative patients, for 55% of SM-positive patients, acquisition did not appear to follow hospitalization. Of 40 SM-positive patients who had a CF sibling, only 10 siblings were ever culture positive. When stratified by FEV1, the two-year survival for SM-positive with mild/moderate disease (98%) and severe disease (78%) was similar to that of our SM-negative patients. Five-year survival was only 40% for SM-positive patients with initially severe pulmonary status, compared with 72% for the SM-negative patients. Seventy percent of the original SM isolates were panresistant (susceptible to no more than one antimicrobial agent). Ten years later, panresistance was 84%. Despite our reassuring experience with SM, including lack of sibling concordance, the fact that the majority of our patients had no hospital exposure prior to acquisition, the high incidence of transient infection, and the seemingly unaffected two-year survival, there are insufficient data to definitively conclude that segregation of these patients would be beneficial. The increasing prevalence of multiply resistant gram-negative pathogens in CF patients suggests the need for continued caution with any panresistant pathogen. PMID:9635931

  8. Draft Genome Sequence of the Biofilm-Forming Stenotrophomonas maltophilia Strain 53.

    PubMed

    Akbar, Sirwan; Rout, Simon P; Humphreys, Paul N

    2015-01-01

    A clinical strain of Stenotrophomonas maltophilia (designated strain 53) was obtained, and a whole-genome sequence was generated. The subsequent draft whole-genome sequence demonstrated the presence of a number of genes encoding for proteins involved in resistance to a number of antimicrobial therapies. PMID:25883296

  9. Whole-Genome Sequence of Stenotrophomonas maltophilia ZBG7B Reveals Its Biotechnological Potential.

    PubMed

    Chan, Kok-Gan; Chong, Teik-Min; Adrian, Tan-Guan-Sheng; Kher, Heng Leong; Hong, Kar-Wai; Grandclément, Catherine; Faure, Denis; Yin, Wai-Fong; Dessaux, Yves

    2015-01-01

    Stenotrophomonas maltophilia ZBG7B was isolated from vineyard soil of Zellenberg, France. Here, we present the draft genome sequence of this bacterial strain, which has facilitated the prediction of function for several genes encoding biotechnologically important enzymes, such as xylosidase, xylanase, laccase, and chitinase. PMID:26659682

  10. Whole-Genome Sequence of Stenotrophomonas maltophilia ZBG7B Reveals Its Biotechnological Potential

    PubMed Central

    Chong, Teik-Min; Adrian, Tan-Guan-Sheng; Kher, Heng Leong; Hong, Kar-Wai; Grandclément, Catherine; Faure, Denis; Yin, Wai-Fong; Dessaux, Yves

    2015-01-01

    Stenotrophomonas maltophilia ZBG7B was isolated from vineyard soil of Zellenberg, France. Here, we present the draft genome sequence of this bacterial strain, which has facilitated the prediction of function for several genes encoding biotechnologically important enzymes, such as xylosidase, xylanase, laccase, and chitinase. PMID:26659682

  11. Draft Genome Sequence of Stenotrophomonas maltophilia Strain UV74 Reveals Extensive Variability within Its Genomic Group.

    PubMed

    Conchillo-Solé, Oscar; Yero, Daniel; Coves, Xavier; Huedo, Pol; Martínez-Servat, Sònia; Daura, Xavier; Gibert, Isidre

    2015-01-01

    We report the draft genome sequence of Stenotrophomonas maltophilia UV74, isolated from a vascular ulcer. This draft genome sequence shall contribute to the understanding of the evolution and pathogenicity of this species, particularly regarding isolates of clinical origin. PMID:26067959

  12. Genome Sequence of Stenotrophomonas maltophilia RR-10, Isolated as an Endophyte from Rice Root

    PubMed Central

    Zhu, Bo; Liu, He; Tian, Wen-Xiao; Fan, Xiao-Ying; Li, Bin; Zhou, Xue-Ping

    2012-01-01

    Stenotrophomonas maltophilia is an endophyte which plays important roles in agricultural production as a plant growth-promoting bacterium. Here, we present the draft genome sequence of strain RR-10, which was isolated from a rice root in a rice field of China. PMID:22328769

  13. The biocide triclosan selects Stenotrophomonas maltophilia mutants that overproduce the SmeDEF multidrug efflux pump.

    PubMed

    Sanchez, Patricia; Moreno, Eduardo; Martinez, Jose L

    2005-02-01

    The possibility that triclosan selects Stenotrophomonas maltophilia mutants overexpressing the multidrug resistance pump SmeDEF is analyzed. Five out of 12 triclosan-selected mutants were less susceptible to antibiotics than the wild-type strain and overproduced SmeDEF. Results are discussed in relation to current debates on the potential selection of antibiotic-resistant bacteria by household biocides. PMID:15673767

  14. Life-threatening hemorrhagic pneumonia caused by Stenotrophomonas maltophilia in the treatment of hematologic diseases.

    PubMed

    Mori, Minako; Tsunemine, Hiroko; Imada, Kazunori; Ito, Kiminari; Kodaka, Taiichi; Takahashi, Takayuki

    2014-06-01

    Since the late 1990s, Stenotrophomonas maltophilia (S. maltophilia) has become one of the most common nonfermenting Gram-negative bacilli that cause opportunistic infection. Patients with hematologic diseases are the most risky candidate for S. maltophilia pneumonia or sepsis because of chemotherapy-induced neutropenia or immunodeficiency. Frequent exposure to broad-spectrum antibiotics and prolonged insertion of central venous catheter further enhance the risk of S. maltophilia infection. One of the most severe S. maltophilia infections is hemorrhagic pneumonia. This type of infection is mostly fatal because of pulmonary alveolar hemorrhage that leads to acute respiratory failure. Furthermore, S. maltophilia exhibits a high-level intrinsic resistance to conventional antibiotics such as β-lactams and aminoglycosides and, more recently, the increasing acquired resistance to co-trimoxazole and quinolones. According to our experienced and previously reported cases, all of the patients with hemorrhagic pneumonia caused by S. maltophilia had a fatal course within a few days after the onset of the pneumonia. In this article, we perform a systematic review on a total 30 cases of hemorrhagic pneumonia induced by S. maltophilia from our institutions and the literature, and we describe its early diagnosis, prophylaxis, and recommended therapeutic strategy for the infection in the treatment of hematologic disease. PMID:24535696

  15. Susceptibility of Stenotrophomonas maltophilia clinical strains in China to antimicrobial combinations.

    PubMed

    Hu, Li-Fen; Gao, Li-Ping; Ye, Ying; Chen, Xi; Zhou, Xiang-Tian; Yang, Hai-Fei; Liiu, Yan-Yan; Mei, Qing; Li, Jia-Bin

    2014-10-01

    We aimed to investigate the activity levels of several combinations of antimicrobials against Stenotrophomonas maltophilia. In this study, the antimicrobial susceptibility of S. maltophilia clinical isolates was determined, and the synergistic activity of three pairs of antimicrobial combinations was evaluated by the fractional inhibitory concentration index (FICI). The antimicrobial susceptibility in vitro against 83 S. maltophilia strains was greater for minocycline (80·7%) than for trimethoprim-sulfamethoxazole (51·8%), and levofloxacin (50·6%). The rate of resistance was highest for ticarcillin-clavulanate and ceftazidime (63·8%) and resistance to trimethoprim-sulfamethoxazole (TMP-SMX) was 48·2%. All three combinations were tested against susceptible isolates. Two of the combinations, TMP-SMX+ceftazidime and levofloxacin+ceftazidime were more effective than the combination of TMP-SMX+levofloxacin. We recommend acquiring more clinical data in order to explore combination therapy, which is a promising treatment of S. maltophilia infections. PMID:24588423

  16. Risk Factors Associated with Stenotrophomonas maltophilia Bacteremia: A Matched Case-Control Study

    PubMed Central

    Sumida, Kosuke; Chong, Yong; Miyake, Noriko; Akahoshi, Tomohiko; Yasuda, Mitsuhiro; Shimono, Nobuyuki; Shimoda, Shinji; Maehara, Yoshihiko; Akashi, Koichi

    2015-01-01

    Stenotrophomonas maltophilia is an important nosocomial bacterial pathogen, as is Pseudomonas aeruginosa. Differentiation of these bacteria as bacteremic agents is critical in the clinical setting and to define a therapeutic strategy; however, the associated factors and prognosis for S. maltophilia bacteremia have not been fully evaluated to adequately characterize these factors. We first conducted a matched case-control study to clarify these questions. A total of 30 case patients with S. maltophilia bacteremia were compared with 30 control patients with P. aeruginosa bacteremia between January 2005 and August 2014, according to matching criteria based on underlying disease, age, and gender. The 30-day mortality rate for the case patients (53.3%) was significantly higher than that of the control group (30.0%) (P = 0.047, using the log-rank test). Conditional logistic regression analysis showed that the predisposing factors specific for the detection of S. maltophilia bacteremia were indwelling artificial products other than a central venous catheter, ICU stay, and previous use of anti-MRSA drugs. The high severity of illness was associated with mortality in both case and control patients. Interestingly, inappropriate antimicrobial treatment was an additional independent risk factor for mortality in only the case patients with S. maltophilia bacteremia (odds ratio = 13.64, P = 0.048). Monotherapy with fluoroquinolones inactive against the S. maltophilia isolates was mainly responsible for the inappropriate treatment. These results suggest that more precise prediction and more appropriate treatment might improve the prognosis of patients with S. maltophilia bacteremia. PMID:26208218

  17. Draft Genome Sequence of Stenotrophomonas maltophilia SeITE02, a Gammaproteobacterium Isolated from Selenite-Contaminated Mining Soil

    PubMed Central

    Bertolini, Cristina; van Aerle, Ronny; Lampis, Silvia; Moore, Karen A.; Paszkiewicz, Konrad; Butler, Clive S.

    2014-01-01

    Stenotrophomonas maltophilia strain SeITE02 was isolated from the rhizosphere of the selenium-hyperaccumulating legume Astragalus bisculcatus. In this report, we provide the 4.56-Mb draft genome sequence of S. maltophilia SeITE02, a gammaproteobacterium that can withstand high concentrations of selenite and reduce these to elemental selenium. PMID:24812214

  18. Genome Sequence of Stenotrophomonas maltophilia Strain SmAs1, Isolated From the Asian Malaria Mosquito Anopheles stephensi

    PubMed Central

    Hughes, Grant L.; Raygoza Garay, Juan Antonio; Koundal, Vikas; Mwangi, Michael M.

    2016-01-01

    An isolate of Stenotrophomonas maltophilia was cultured from the Asian malaria vector Anopheles stephensi. Here, we present the annotated draft genome sequence of this S. maltophilia strain. This genomic resource will facilitate further characterization of bacteria associated with mosquitoes. PMID:26966198

  19. Genome Sequence of Stenotrophomonas maltophilia Strain SmAs1, Isolated From the Asian Malaria Mosquito Anopheles stephensi.

    PubMed

    Hughes, Grant L; Raygoza Garay, Juan Antonio; Koundal, Vikas; Rasgon, Jason L; Mwangi, Michael M

    2016-01-01

    An isolate of Stenotrophomonas maltophilia was cultured from the Asian malaria vector Anopheles stephensi. Here, we present the annotated draft genome sequence of this S. maltophilia strain. This genomic resource will facilitate further characterization of bacteria associated with mosquitoes. PMID:26966198

  20. Molecular Heterogeneity of the L-1 Metallo-β-Lactamase Family from Stenotrophomonas maltophilia

    PubMed Central

    Sanschagrin, François; Dufresne, Julien; Levesque, Roger C.

    1998-01-01

    We have determined the nucleotide sequence of the blaS gene encoding the carbapenem-hydrolyzing L-1 β-lactamase from Stenotrophomonas maltophilia GN12873. Analysis of the DNA and deduced amino acid sequences identified a product of 290 amino acids. Comparisons of the L-1 amino acid sequence with those of other zinc β-lactamases showed 88.6% identity with the L-1 enzyme from S. maltophilia IID1275 and less than 20% identity with other class B metalloenzymes. PMID:9593158

  1. Genomic sequence of temperate phage Smp131 of Stenotrophomonas maltophilia that has similar prophages in xanthomonads

    PubMed Central

    2014-01-01

    Background Stenotrophomonas maltophilia is a ubiquitous Gram-negative bacterium previously named as Xanthomonas maltophilia. This organism is an important nosocomial pathogen associated with infections in immunocompromised patients. Clinical isolates of S. maltophilia are mostly resistant to multiple antibiotics and treatment of its infections is becoming problematic. Several virulent bacteriophages, but not temperate phage, of S. maltophilia have been characterized. Results In this study, a temperate myophage of S. maltophilia (Smp131) was isolated and characterized. Sequence analysis showed that its genome is 33,525-bp long with 47 open reading frames (ORFs). Its similarity to P2-like phages and prophages in S. maltophilia and several Xanthomonas pathovars includes genomic organization, arrangement of several operons, and possession of a slippery sequence T7G for translational frameshifting in tail assembly genes. Smp131 encodes a tyrosine family integrase that shares low degrees of similarity with those of other phages and a lysin belonging to family 19 chitinase that is observed in plants and some bacteria, although not in phages. tRNA are the preferred sites for host integration of Smp131 and the related phages: tRNA-Thr for Smp131 and prophage of S. maltophilia K279a; tRNA-Lys for prophages of X. campestris pv. campestris ATCC33913, X. oryzae pv. oryzae strains MAFF311018, and KACC10331; and tRNA-Asn for prophage of X. oryzae pv. oryzae PXO99A and remnant of X. axonopodis pv. citri 306. Regions flanking the prophages are varied highly in nucleotide sequence and rich in transposase genes, suggesting that frequent insertion/excision had occurred. Conclusions Prevalence of closely related prophages in Stenotrophomonas and Xanthomonads may have contributed to the diversity of these closely related species owing to possible horizontal gene transfer mediated by the phages. PMID:24472137

  2. A Stenotrophomonas maltophilia Strain Evades a Major Caenorhabditis elegans Defense Pathway.

    PubMed

    White, Corin V; Darby, Brian J; Breeden, Robert J; Herman, Michael A

    2016-02-01

    Stenotrophomonas maltophilia is a ubiquitous bacterium and an emerging nosocomial pathogen. This bacterium is resistant to many antibiotics, associated with a number of infections, and a significant health risk, especially for immunocompromised patients. Given that Caenorhabditis elegans shares many conserved genetic pathways and pathway components with higher organisms, the study of its interaction with bacterial pathogens has biomedical implications. S. maltophilia has been isolated in association with nematodes from grassland soils, and it is likely that C. elegans encounters this bacterium in nature. We found that a local S. maltophilia isolate, JCMS, is more virulent than the other S. maltophilia isolates (R551-3 and K279a) tested. JCMS virulence correlates with intestinal distension and bacterial accumulation and requires the bacteria to be alive. Many of the conserved innate immune pathways that serve to protect C. elegans from various pathogenic bacteria also play a role in combating S. maltophilia JCMS. However, S. maltophilia JCMS is virulent to normally pathogen-resistant DAF-2/16 insulin-like signaling pathway mutants. Furthermore, several insulin-like signaling effector genes were not significantly differentially expressed between S. maltophilia JCMS and avirulent bacteria (Escherichia coli OP50). Taken together, these findings suggest that S. maltophilia JCMS evades the pathogen resistance conferred by the loss of DAF-2/16 pathway components. In summary, we have discovered a novel host-pathogen interaction between C. elegans and S. maltophilia and established a new animal model with which to study the mode of action of this emerging nosocomial pathogen. PMID:26644380

  3. Adhesion of the positively charged bacterium Stenotrophomonas (Xanthomonas) maltophilia 70401 to glass and Teflon.

    PubMed Central

    Jucker, B A; Harms, H; Zehnder, A J

    1996-01-01

    Medical implants are often colonized by bacteria which may cause severe infections. The initial step in the colonization, the adhesion of bacteria to the artificial solid surface, is governed mainly by long-range van der Waals and electrostatic interactions between the solid surface and the bacterial cell. While van der Waals forces are generally attractive, the usually negative charge of bacteria and solid surfaces leads to electrostatic repulsion. We report here on the adhesion of a clinical isolate, Stenotrophomonas maltophilia 70401, which is, at physiological pH, positively charged. S. maltophilia has an electrophoretic mobility of +0.3 x 10(-8) m2 V-1 s-1 at pH 7 and an overall surface isoelectric point at pH 11. The positive charge probably originates from proteins located in the outer membrane. For this bacterium, both long-range forces involved in adhesion are attractive. Consequently, adhesion of S. maltophilia to negatively charged surfaces such as glass and Teflon is much favored compared with the negatively charged bacterium Pseudomonas putida mt2. While adhesion of negatively charged bacteria is impeded in media of low ionic strength because of a thick negatively charged diffuse layer, adhesion of S. maltophilia was particularly favored in dilute medium. The adhesion efficiencies of S. maltophilia at various ionic strengths could be explained in terms of calculated long-range interaction energies between S. maltophilia and glass or Teflon. PMID:8808938

  4. Fimbriae and adherence of Stenotrophomonas maltophilia to epithelial cells and to abiotic surfaces.

    PubMed

    de Oliveira-Garcia, Doroti; Dall'Agnol, Monique; Rosales, Mónica; Azzuz, Ana C G S; Alcántara, Norma; Martinez, Marina B; Girón, Jorge A

    2003-09-01

    Stenotrophomonas maltophilia is an emerging nosocomial bacterial pathogen associated with several infectious diseases and opportunistic infections, especially in immunocompromised patients. These bacteria adhere avidly to medical implants and catheters forming a biofilm that confers natural protection against host immune defences and different antimicrobial agents. The nature of the bacterial surface factors involved in biofilm formation on inert surfaces and in adherence of S. maltophilia to epithelial cells is largely unknown. In this study, we identified and characterized fimbrial structures produced by S. maltophilia grown at 37 degrees C. The S. maltophilia fimbriae 1 (SMF-1) are composed of a 17 kDa fimbrin subunit which shares significant similarities with the N-terminal amino acid sequences of several fimbrial adhesins (G, F17, K99 and 20K) found in Escherichia coli pathogenic strains and the CupA fimbriae of Pseudomonas aeruginosa. All of the clinical S. maltophilia isolates tested produced the 17 kDa fimbrin. Antibodies raised against SMF-1 fimbriae inhibited the agglutination of animal erythrocytes, adherence to HEp-2 cells and biofilm formation by S. maltophilia. High resolution electron microscopy provided evidence of the presence of fimbriae acting as bridges between bacteria adhering to inert surfaces or to cultured epithelial cells. This is the first characterization of fimbriae in this genus. We provide compelling data suggesting that the SMF-1 fimbriae are involved in haemagglutination, biofilm formation and adherence to cultured mammalian cells. PMID:12925132

  5. Stenotrophomonas maltophilia in Mexico: antimicrobial resistance, biofilm formation and clonal diversity.

    PubMed

    Flores-Treviño, Samantha; Gutiérrez-Ferman, Jessica Lizzeth; Morfín-Otero, Rayo; Rodríguez-Noriega, Eduardo; Estrada-Rivadeneyra, Diego; Rivas-Morales, Catalina; Llaca-Díaz, Jorge M; Camacho-Ortíz, Adrián; Mendoza-Olazarán, Soraya; Garza-González, Elvira

    2014-11-01

    Stenotrophomonas maltophilia is an important multidrug-resistant nosocomial pathogen associated with high mortality. Our aim was to examine antimicrobial susceptibility, biofilm production and clonal relatedness of clinical isolates of S. maltophilia. S. maltophilia isolates were collected between 2006 and 2013 from two tertiary care hospitals in Mexico. Antimicrobial susceptibility was evaluated by the broth microdilution method. PCR was used to determine the presence of β-lactamase genes L1 and L2. Biofilm formation was assessed with crystal violet staining. Clonal relatedness was determined by PFGE. Among the 119 collected S. maltophilia isolates, 73 (61.3%) were from the respiratory tract. Resistance levels exceeded 75% for imipenem, meropenem, ampicillin, aztreonam, gentamicin and tobramycin. Resistance to trimethoprim-sulfamethoxazole was 32.8%. L1 and L2 genes were detected in 77.1% (91/118) and 66.9% (79/118) of isolates, respectively. All S. maltophilia strains were able to produce biofilms. Strains were classified as weak (47.9%, 57/119), moderate (38.7%, 46/119), or strong (13.4%, 16/119) biofilm producers. A total of 89 distinct PFGE types were identified and 21.6% (22/102) of the isolates were distributed in nine clusters. This is the first study in Mexico to reveal characteristics of clinical isolates of S. maltophilia. Clonal diversity data indicate low cross-transmission of S. maltophilia in a hospital setting. The high antibiotic resistance underscores the need for continuous surveillance of S. maltophilia in hospital settings in Mexico. PMID:25165124

  6. Stenotrophomonas maltophilia Pseudo-outbreak at a University Hospital Bronchoscopy Unit in Turkey

    PubMed Central

    Ece, G; Erac, B; Limoncu, MH; Baysak, A; Oz, AT; Ceylan, KC

    2014-01-01

    Objective: Stenotrophomonas maltophilia is an opportunistic pathogen found predominantly in the enviroment and hospital setting. Invasive procedures and treatment methods, instruments used for diagnosis and irrational antibiotic use play major roles in the spread of this pathogen. The study aimed to evaluate consecutive S maltophilia isolation from bronchoalveolar lavage samples during bronchoscopy procedure during a week. Methods: Four patients consecutively had S maltophilia isolated during bronchoscopy between September 8 and 15, 2012. The identification of the isolates and their antibiotic susceptibility were studied by automated Vitek version 2.0 (Biomerieux, France) system. The clonal relationship between the isolates was studied by enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction (PCR). Results: Four consecutive S maltophilia isolates had identical band patterns and showed clonal relatedness. Conclusion: Bronchoscopy is a common invasive procedure that is utilized in chest diseases departments and intensive care units (ICUs). Contamination may take place due to inappropiate use and cause spread of infectious pathogens. In the current study, we detected consecutive S maltophilia strains with identical band patterns isolated within a week. After appropiate disinfection and cleaning procedures, no further isolation was detected. PMID:25303196

  7. Electronic ventilator temperature sensors as a potential source of respiratory tract colonization with Stenotrophomonas maltophilia.

    PubMed

    Rogues, A M; Maugein, J; Allery, A; Fleureau, C; Boulestreau, H; Surcin, S; Bebear, C; Janvier, G; Gachie, J P

    2001-12-01

    Stenotrophomonas maltophilia (S. maltophilia) is an important cause of nosocomial infection among ventilated and immunocompromised patients, and among patients receiving broad-spectrum antimicrobials. We report a cluster of patients in a surgical intensive care unit who were colonized or infected with S. maltophilia. An epidemiological investigation was initiated after surveillance data revealed that eight patients were culture-positive from sputum for S. maltophilia in the preceding month. Review of respiratory care procedures revealed that when mechanical ventilators were serviced between patients, the electronic temperature probes used with servo-controlled humidifiers were wiped with inadequate disinfection. We collected cultures of case-patient room surfaces, sinks and ventilator equipment. S. maltophilia was recovered from room surfaces, ventilator expiratory circuits and a temperature sensor which had been kept in ambient air after disinfection. Patients and environmental isolates were examined by RAPD-PCR. Three clinical isolates and one environmental isolate had the same profile, which suggests cross-contamination or common source exposure. The outbreak was controlled by adequate disinfection of the temperature sensors. No single epidemic strain was identified but several observations support the conclusion that the temperature probes contributed to the outbreak. PMID:11740879

  8. Stenotrophomonas maltophilia Infections in a General Hospital: Patient Characteristics, Antimicrobial Susceptibility, and Treatment Outcome

    PubMed Central

    Samonis, George; Karageorgopoulos, Drosos E.; Maraki, Sofia; Levis, Panagiotis; Dimopoulou, Dimitra; Spernovasilis, Nikolaos A.; Kofteridis, Diamantis P.; Falagas, Matthew E.

    2012-01-01

    Introduction Stenotrophomonas maltophilia is acquiring increasing importance as a nosocomial pathogen. Methods We retrospectively studied the characteristics and outcome of patients with any type of S. maltophilia infection at the University Hospital of Heraklion, Crete, Greece, between 1/2005–12/2010. S. maltophilia antimicrobial susceptibility was tested with the agar dilution method. Prognostic factors for all-cause in-hospital mortality were assessed with multivariate logistic regression. Results Sixty-eight patients (median age: 70.5 years; 64.7% males) with S. maltophilia infection, not related to cystic fibrosis, were included. The 68 patients were hospitalized in medical (29.4%), surgical (26.5%), hematology/oncology departments (23.5%), or the intensive care units (ICU; 20.6%). The most frequent infection types were respiratory tract (54.4%), bloodstream (16.2%), skin/soft tissue (10.3%), and intra-abdominal (8.8%) infection. The S. maltophilia-associated infection was polymicrobial in 33.8% of the cases. In vitro susceptibility was higher to colistin (91.2%), trimethoprim/sulfamethoxazole and netilmicin (85.3% each), and ciprofloxacin (82.4%). The empirical and the targeted treatment regimens were microbiologically appropriate for 47.3% and 63.6% of the 55 patients with data available, respectively. Most patients received targeted therapy with a combination of agents other than trimethoprim/sulfamethoxazole. The crude mortality and the mortality and the S. maltophilia infection-related mortality were 14.7% and 4.4%, respectively. ICU hospitalization was the only independent prognostic factor for mortality. Conclusion S. maltophilia infection in a general hospital can be associated with a good prognosis, except for the patients hospitalized in the ICU. Combination reigmens with fluoroquinolones, colistin, or tigecycline could be alternative treatment options to trimethoprim/sulfamethoxazole. PMID:22624022

  9. Update on infections caused by Stenotrophomonas maltophilia with particular attention to resistance mechanisms and therapeutic options.

    PubMed

    Chang, Ya-Ting; Lin, Chun-Yu; Chen, Yen-Hsu; Hsueh, Po-Ren

    2015-01-01

    Stenotrophomonas maltophilia is a Gram-negative, biofilm-forming bacterium. Although generally regarded as an organism of low virulence, S. maltophilia is an emerging multi-drug resistant opportunistic pathogen in hospital and community settings, especially among immunocompromised hosts. Risk factors associated with S. maltophilia infection include underlying malignancy, cystic fibrosis, corticosteroid or immunosuppressant therapy, the presence of an indwelling central venous catheter and exposure to broad spectrum antibiotics. In this review, we provide a synthesis of information on current global trends in S. maltophilia pathogenicity as well as updated information on the molecular mechanisms contributing to its resistance to an array of antimicrobial agents. The prevalence of S. maltophilia infection in the general population increased from 0.8-1.4% during 1997-2003 to 1.3-1.68% during 2007-2012. The most important molecular mechanisms contributing to its resistance to antibiotics include β-lactamase production, the expression of Qnr genes, and the presence of class 1 integrons and efflux pumps. Trimethoprim/sulfamethoxazole (TMP/SMX) is the antimicrobial drug of choice. Although a few studies have reported increased resistance to TMP/SMX, the majority of studies worldwide show that S. maltophilia continues to be highly susceptible. Drugs with historically good susceptibility results include ceftazidime, ticarcillin-clavulanate, and fluoroquinolones; however, a number of studies show an alarming trend in resistance to those agents. Tetracyclines such as tigecycline, minocycline, and doxycycline are also effective agents and consistently display good activity against S. maltophilia in various geographic regions and across different time periods. Combination therapies, novel agents, and aerosolized forms of antimicrobial drugs are currently being tested for their ability to treat infections caused by this multi-drug resistant organism. PMID:26388847

  10. Functional properties of the major outer membrane protein in Stenotrophomonas maltophilia.

    PubMed

    Chen, Yih-Yuan; Wu, Han-Chiang; Lin, Juey-Wen; Weng, Shu-Fen

    2015-08-01

    Stenotrophomonas maltophilia is an opportunistic pathogen that is closely associated with high morbidity and mortality in debilitated and immunocompromised individuals. Therefore, to investigate the pathogenesis mechanism is urgently required. However, there are very few studies to evaluate the functional properties of outer membrane protein, which may contribute to the pathogenesis in S. maltophilia. In this study, three abundant proteins in the outer membrane fraction of S. maltophilia were identified by liquid chromatography-tandem mass spectrometry as OmpW1, MopB, and a hypothetical protein. MopB, a member of the OmpA family, was firstly chosen for functional investigation in this study because many OmpA-family proteins are known to be involved in pathogenesis and offer potential as vaccines. Membrane fractionation analyses demonstrated that MopB was indeed the most abundant outer membrane protein (OMP) in S. maltophilia. For functional studies, the mopB mutant of S. maltophilia (SmMopB) was constructed by insertional mutation. MopB deficiency resulted in a change in the protein composition of OMPs and altered the architecture of the outer membrane. The SmMopB strain exhibited reduced cytotoxicity toward L929 fibroblasts and was more sensitive to numerous stresses, including human serum, sodium dodecyl sulfate, and hydrogen peroxide compared with wildtype S. maltophilia. These results suggest that MopB may be a good candidate for the design of vaccines or anti-MopB drugs for controlling serious nosocomial infections of multidrug-resistant S. maltophilia, especially in immunosuppressed patients. PMID:26224456

  11. Update on infections caused by Stenotrophomonas maltophilia with particular attention to resistance mechanisms and therapeutic options

    PubMed Central

    Chang, Ya-Ting; Lin, Chun-Yu; Chen, Yen-Hsu; Hsueh, Po-Ren

    2015-01-01

    Stenotrophomonas maltophilia is a Gram-negative, biofilm-forming bacterium. Although generally regarded as an organism of low virulence, S. maltophilia is an emerging multi-drug resistant opportunistic pathogen in hospital and community settings, especially among immunocompromised hosts. Risk factors associated with S. maltophilia infection include underlying malignancy, cystic fibrosis, corticosteroid or immunosuppressant therapy, the presence of an indwelling central venous catheter and exposure to broad spectrum antibiotics. In this review, we provide a synthesis of information on current global trends in S. maltophilia pathogenicity as well as updated information on the molecular mechanisms contributing to its resistance to an array of antimicrobial agents. The prevalence of S. maltophilia infection in the general population increased from 0.8–1.4% during 1997–2003 to 1.3–1.68% during 2007–2012. The most important molecular mechanisms contributing to its resistance to antibiotics include β-lactamase production, the expression of Qnr genes, and the presence of class 1 integrons and efflux pumps. Trimethoprim/sulfamethoxazole (TMP/SMX) is the antimicrobial drug of choice. Although a few studies have reported increased resistance to TMP/SMX, the majority of studies worldwide show that S. maltophilia continues to be highly susceptible. Drugs with historically good susceptibility results include ceftazidime, ticarcillin-clavulanate, and fluoroquinolones; however, a number of studies show an alarming trend in resistance to those agents. Tetracyclines such as tigecycline, minocycline, and doxycycline are also effective agents and consistently display good activity against S. maltophilia in various geographic regions and across different time periods. Combination therapies, novel agents, and aerosolized forms of antimicrobial drugs are currently being tested for their ability to treat infections caused by this multi-drug resistant organism. PMID:26388847

  12. Resistance of Stenotrophomonas maltophilia to Fluoroquinolones: Prevalence in a University Hospital and Possible Mechanisms

    PubMed Central

    Jia, Wei; Wang, Jiayuan; Xu, Haotong; Li, Gang

    2015-01-01

    Objective: The purpose of this study was to investigate the clinical distribution and genotyping of Stenotrophomonas maltophilia, its resistance to antimicrobial agents, and the possible mechanisms of this drug resistance. Methods: S. maltophilia isolates were collected from clinical specimens in a university hospital in Northwestern China during the period between 2010 and 2012, and were identified to the species level with a fully automated microbiological system. Antimicrobial susceptibility testing was performed for S. maltophilia with the Kirby-Bauer disc diffusion method. The minimal inhibitory concentrations (MICs) of norfloxacin, ofloxacin, chloramphenicol, minocycline, ceftazidime, levofloxacin and ciprofloxacin against S. maltophilia were assessed using the agar dilution method, and changes in the MIC of norfloxacin, ciprofloxacin and ofloxacin were observed after the addition of reserpine, an efflux pump inhibitor. Fluoroquinolone resistance genes were detected in S. maltophilia using a polymerase chain reaction (PCR) assay, and the expression of efflux pump smeD and smeF genes was determined using a quantitative fluorescent (QF)-PCR assay. Pulsed-field gel electrophoresis (PFGE) was employed to genotype identified S. maltophilia isolates. Results: A total of 426 S. maltophilia strains were isolated from the university hospital from 2010 to 2012, consisting of 10.1% of total non-fermentative bacteria. The prevalence of norfloxacin, ciprofloxacin and ofloxacin resistance was 32.4%, 21.9% and 13.2% in the 114 S. maltophilia isolates collected from 2012, respectively. Following reserpine treatment, 19 S. maltophilia isolates positive for efflux pump were identified, and high expression of smeD and smeF genes was detected in two resistant isolates. gyrA, parC, smeD, smeE and smeF genes were detected in all 114 S. maltophilia isolates, while smqnr gene was found in 25.4% of total isolates. Glu-Lys mutation (GAA-AAA) was detected at the 151th amino acid of the gyrA gene, while Gly-Arg mutation (GGC-CGC) was found at the 37th amino acid of the parC gene. However, no significant difference was observed in the prevalence of gyrA or parC mutation between fluoroquinolone-resistant and -susceptible isolates (p> 0.05). The smqnr gene showed 92% to 99% heterogenicity among the 14 S. maltophilia clinical isolates. PFGE of 29 smqnr gene-positive S. maltophilia clinical isolates revealed 25 PFGE genotypes and 28 subgenotypes. Conclusions: Monitoring the clinical distribution and antimicrobial resistance of S. maltophilia is of great significance for the clinical therapy of bacterial infections. Reserpine is effective to inhibit the active efflux of norfloxacin, ciprofloxacin and ofloxacin on S. maltophilia and reduce MIC of fluoroquinolones against the bacteria. The expression of efflux pump smeD and smeF genes correlates with the resistance of S. maltophilia to fluoroquinolones. PMID:25985315

  13. Clonal diversity and metallo-beta-lactamase production in clinical isolates of Stenotrophomonas maltophilia.

    PubMed

    Mercuri, Paola Sandra; Ishii, Yoshikazu; Ma, Ling; Rossolini, Gian Maria; Luzzaro, Francesco; Amicosante, Gianfranco; Franceschini, Nicola; Frere, Jean-Marie; Galleni, Moreno

    2002-01-01

    Stenotrophomonas maltophilia is a nosocomial pathogen with an intrinsic broad-spectrum resistance to beta-lactam compounds and other antibacterial agents. It produces two chromosomal beta-lactamases: a clavulanic acid-sensitive class A (L2) and a tetrameric carbapenemase (L1 or BlaS). We screened 40 S. maltophilia multidrug-resistant clinical isolates recovered between 1995 and 1998 in the Varese Hospital (Italy) for the presence of the metallo-beta-lactamase. The isolates were investigated by phenotypic profiling (enzymatic activity and antibiotic resistance pattern) and molecular methods such as PCR and pulsed-field gel electrophoresis (PFGE) to reveal intraspecies diversity. For the tested S. maltophilia strains, we showed that the beta-lactamase production could be induced by the presence of imipenem (50 microg/ml) in the culture media. Addition of 1 mM dipicolinic acid completely inhibited the hydrolysis of imipenem but decreased that nitrocefin in a strain-dependent manner. Full activity of crude extract towards imipenem could be restored by addition of 1 mM ZnCl2. Finally, the gene encoding the carbapenem-hydrolyzing beta-lactamase from S. maltophilia ULA-511 and 39/95, a clinical strain, were isolated and sequenced. These two strains have a different profile of multidrug resistance. The two metallo-beta-lactamases were found to be isologous. The difference of sensitivity of these two strains was associated to the level of production of the metallo-beta-lactamase. PMID:12363008

  14. Activity of colistin in combination with tigecycline or rifampicin against multidrug-resistant Stenotrophomonas maltophilia.

    PubMed

    Betts, J W; Phee, L M; Woodford, N; Wareham, D W

    2014-09-01

    The antimicrobial treatment of Stenotrophomonas maltophilia infections is complicated by intrinsic multidrug resistance and a lack of reliable susceptibility data. We assessed the activity of colistin (COL), rifampicin (RIF) and tigecycline (TGC) alone and in combination using a range of in vitro susceptibility testing methodologies and a simple invertebrate model of S. maltophilia infection (Galleria mellonella). Synergy [fractional inhibitory concentration indices (FICIs) ≤0.5] between COL and either RIF or TGC was observed against 92 % and 88 % of 25 S. maltophilia isolates, respectively, despite resistance to one or another of the single agents alone. In time-kill assays, COL combined with either RIF or TGC was superior to single agents, but only the COL/RIF regimen was reliably bactericidal. The in vitro findings correlated with treatment outcomes in G. mellonella, with heightened survival observed for larvae treated with COL/RIF or COL/TGC compared with COL, RIF or TGC alone. COL combined with RIF was the most effective combination overall in both in vitro and in vivo (p < 0.05) assays. Given the difficulty in selecting appropriate therapy for S. maltophilia infections, regimens consisting of COL combined with RIF or TGC could be considered for clinical use. PMID:24781003

  15. The sul1 gene in Stenotrophomonas maltophilia with high-level resistance to trimethoprim/sulfamethoxazole.

    PubMed

    Chung, Hae-Sun; Kim, Kyeongmi; Hong, Sang Sook; Hong, Seong Geun; Lee, Kyungwon; Chong, Yunsop

    2015-03-01

    Emerging resistance to trimethoprim/sulfamethoxazole (SXT) poses a serious threat to the treatment of Stenotrophomonas maltophilia infections. We determined the prevalence and molecular characteristics of acquired SXT resistance in recent clinical S. maltophilia isolates obtained from Korea. A total of 252 clinical isolates of S. maltophilia were collected from 10 university hospitals in Korea between 2009 and 2010. Antimicrobial susceptibility was determined by using the CLSI agar dilution method. The sul1, sul2, and sul3 genes, integrons, insertion sequence common region (ISCR) elements, and dfrA genes were detected using PCR. The presence of the sul1 gene and integrons was confirmed through sequence analysis. Among the 32 SXT-resistant isolates, sul1 was detected in 23 isolates (72%), all of which demonstrated high-level resistance (≥64 mg/L) to SXT. The sul1 gene (varying in size and structure) was linked to class 1 integrons in 15 of the 23 isolates (65%) harboring this gene. None of the SXT-susceptible isolates or the SXT-resistant isolates with a minimum inhibitory concentration of 4 and 8 mg/L were positive for sul1. Moreover, the sul2, sul3, and dfrA genes or the ISCR elements were not detected. The sul1 gene may play an important role in the high-level SXT resistance observed in S. maltophilia. PMID:25729729

  16. An overview of various typing methods for clinical epidemiology of the emerging pathogen Stenotrophomonas maltophilia.

    PubMed

    Gherardi, Giovanni; Creti, Roberta; Pompilio, Arianna; Di Bonaventura, Giovanni

    2015-03-01

    Typing of bacterial isolates has been used for decades to study local outbreaks as well as in national and international surveillances for monitoring newly emerging resistant clones. Despite being recognized as a nosocomial pathogen, the precise modes of transmission of Stenotrophomonas maltophilia in health care settings are unknown. Due to the high genetic diversity observed among S. maltophilia clinical isolates, the typing results might be better interpreted if also environmental strains were included. This could help to identify preventative measures to be designed and implemented for decreasing the possibility of outbreaks and nosocomial infections. In this review, we attempt to provide an overview on the most common typing methods used for clinical epidemiology of S. maltophilia strains, such as PCR-based fingerprinting analyses, pulsed-field gel electrophoresis, multilocus variable number tandem repeat analysis, and multilocus sequence type. Application of the proteomic-based mass spectrometry by matrix-assisted laser desorption ionization-time of flight is also described. Improvements of typing methods already in use have to be achieved to facilitate S. maltophilia infection control at any level. In the near future, when novel Web-based platforms for rapid data processing and analysis will be available, whole genome sequencing technologies will likely become a highly powerful tool for outbreak investigations and surveillance studies in routine clinical practices. PMID:25592000

  17. Facile biosynthesis of phosphate capped gold nanoparticles by a bacterial isolate Stenotrophomonas maltophilia

    NASA Astrophysics Data System (ADS)

    Nangia, Yogesh; Wangoo, Nishima; Sharma, Saurabh; Wu, Jin-Song; Dravid, Vinayak; Shekhawat, G. S.; Raman Suri, C.

    2009-06-01

    We report intracellular biosynthesis of gold nanoparticles (GNPs) by a strain Stenotrophomonas maltophilia (AuRed02) isolated from the soil samples of Singhbhum gold mines, India. An aqueous solution of gold chloride was reduced to metallic gold in a suspension of disrupted cell mass of AuRed02, which progressively turns into cherry red within 8 h of incubation at 25 °C. The optical spectrum showed the plasmon resonance at 530 nm and analysis by transmission electron microscopy and dynamic light scattering confirmed the formation of around 40 nm GNPs. Zeta potential and Fourier transform infrared measurements confirmed GNPs are capped by negatively charged phosphate groups of NADP.

  18. Facile biosynthesis of phosphate capped gold nanoparticles by a bacterial isolate Stenotrophomonas maltophilia

    SciTech Connect

    Nangia, Yogesh; Wangoo, Nishima; Raman Suri, C.; Sharma, Saurabh; Wu, J.-S.; Dravid, Vinayak; Shekhawat, G. S.

    2009-06-08

    We report intracellular biosynthesis of gold nanoparticles (GNPs) by a strain Stenotrophomonas maltophilia (AuRed02) isolated from the soil samples of Singhbhum gold mines, India. An aqueous solution of gold chloride was reduced to metallic gold in a suspension of disrupted cell mass of AuRed02, which progressively turns into cherry red within 8 h of incubation at 25 deg. C. The optical spectrum showed the plasmon resonance at 530 nm and analysis by transmission electron microscopy and dynamic light scattering confirmed the formation of around 40 nm GNPs. Zeta potential and Fourier transform infrared measurements confirmed GNPs are capped by negatively charged phosphate groups of NADP.

  19. Central venous catheter-related blood stream infection with pyomyositis due to Stenotrophomonas maltophilia after allogeneic bone marrow transplantation in a patient with aplastic anemia.

    PubMed

    Kodama, Yuichi; Okamoto, Yasuhiro; Tanabe, Takayuki; Nishikawa, Takuro; Abematsu, Takanari; Nakagawa, Shunsuke; Kurauchi, Koichiro; Shinkoda, Yuichi; Ikeda, Naohiro; Seki, Shunji; Wakiguchi, Hiroyuki; Miyazono, Akinori; Kawano, Yoshifumi

    2016-03-01

    Stenotrophomonas maltophilia causes pneumonia and CVC-CRBSI in HSCT. However, there are few reports of pyomyositis due to S. maltophilia. We report a patient with CRBSI and pyomyositis due to S. maltophilia after allogeneic HSCT who was successfully treated by removing the CVC and antibiotics without surgical drainage. Removing the CVC and the combined antibiotics without preventing the neutrophil engraftment could avoid surgical drainage in pyomyositis due to S. maltophilia when detected in an early stage. PMID:26918735

  20. Stenotrophomonas maltophilia PhoP, a Two-Component Response Regulator, Involved in Antimicrobial Susceptibilities.

    PubMed

    Liu, Ming-Che; Tsai, Yi-Lin; Huang, Yi-Wei; Chen, Hsing-Yu; Hsueh, Po-Ren; Lai, Szu-Yu; Chen, Li-Chia; Chou, Yi-Hwa; Lin, Wen-Yuan; Liaw, Shwu-Jen

    2016-01-01

    Stenotrophomonas maltophilia, a gram-negative bacterium, has increasingly emerged as an important nosocomial pathogen. It is well-known for resistance to a variety of antimicrobial agents including cationic antimicrobial polypeptides (CAPs). Resistance to polymyxin B, a kind of CAPs, is known to be controlled by the two-component system PhoPQ. To unravel the role of PhoPQ in polymyxin B resistance of S. maltophilia, a phoP mutant was constructed. We found MICs of polymyxin B, chloramphenicol, ampicillin, gentamicin, kanamycin, streptomycin and spectinomycin decreased 2-64 fold in the phoP mutant. Complementation of the phoP mutant by the wild-type phoP gene restored all of the MICs to the wild type levels. Expression of PhoP was shown to be autoregulated and responsive to Mg2+ levels. The polymyxin B and gentamicin killing tests indicated that pretreatment of low Mg2+ can protect the wild-type S. maltophilia from killing but not phoP mutant. Interestingly, we found phoP mutant had a decrease in expression of SmeZ, an efflux transporter protein for aminoglycosides in S. maltophilia. Moreover, phoP mutant showed increased permeability in the cell membrane relative to the wild-type. In summary, we demonstrated the two-component regulator PhoP of S. maltophilia is involved in antimicrobial susceptibilities and low Mg2+ serves as a signal for triggering the pathway. Both the alteration in membrane permeability and downregulation of SmeZ efflux transporter in the phoP mutant contributed to the increased drug susceptibilities of S. maltophilia, in particular for aminoglycosides. This is the first report to describe the role of the Mg2+-sensing PhoP signaling pathway of S. maltophilia in regulation of the SmeZ efflux transporter and in antimicrobial susceptibilities. This study suggests PhoPQ TCS may serve as a target for development of antimicrobial agents against multidrug-resistant S. maltophilia. PMID:27159404

  1. Stenotrophomonas maltophilia PhoP, a Two-Component Response Regulator, Involved in Antimicrobial Susceptibilities

    PubMed Central

    Huang, Yi-Wei; Chen, Hsing-Yu; Hsueh, Po-Ren; Lai, Szu-Yu; Chen, Li-Chia; Chou, Yi-Hwa; Lin, Wen-Yuan; Liaw, Shwu-Jen

    2016-01-01

    Stenotrophomonas maltophilia, a gram-negative bacterium, has increasingly emerged as an important nosocomial pathogen. It is well-known for resistance to a variety of antimicrobial agents including cationic antimicrobial polypeptides (CAPs). Resistance to polymyxin B, a kind of CAPs, is known to be controlled by the two-component system PhoPQ. To unravel the role of PhoPQ in polymyxin B resistance of S. maltophilia, a phoP mutant was constructed. We found MICs of polymyxin B, chloramphenicol, ampicillin, gentamicin, kanamycin, streptomycin and spectinomycin decreased 2–64 fold in the phoP mutant. Complementation of the phoP mutant by the wild-type phoP gene restored all of the MICs to the wild type levels. Expression of PhoP was shown to be autoregulated and responsive to Mg2+ levels. The polymyxin B and gentamicin killing tests indicated that pretreatment of low Mg2+ can protect the wild-type S. maltophilia from killing but not phoP mutant. Interestingly, we found phoP mutant had a decrease in expression of SmeZ, an efflux transporter protein for aminoglycosides in S. maltophilia. Moreover, phoP mutant showed increased permeability in the cell membrane relative to the wild-type. In summary, we demonstrated the two-component regulator PhoP of S. maltophilia is involved in antimicrobial susceptibilities and low Mg2+ serves as a signal for triggering the pathway. Both the alteration in membrane permeability and downregulation of SmeZ efflux transporter in the phoP mutant contributed to the increased drug susceptibilities of S. maltophilia, in particular for aminoglycosides. This is the first report to describe the role of the Mg2+-sensing PhoP signaling pathway of S. maltophilia in regulation of the SmeZ efflux transporter and in antimicrobial susceptibilities. This study suggests PhoPQ TCS may serve as a target for development of antimicrobial agents against multidrug-resistant S. maltophilia. PMID:27159404

  2. Identification of swine influenza A virus and Stenotrophomonas maltophilia co-infection in Chinese pigs

    PubMed Central

    2012-01-01

    Background Influenza virus virulence can be exacerbated by bacterial co-infections. Swine influenza virus (SIV) infection together with some bacteria is found to enhance pathogenicity. Methods SIV-positive samples suspected of containing bacteria were used for bacterial isolation and identification. Antimicrobial susceptibility testing was performed by disc diffusion methods. To investigate the interaction of SIV and the bacteria in vitro, guinea pigs were used as mammalian hosts to determine the effect on viral susceptibility and transmissibility. Differences in viral titers between groups were compared using Students t-test. Results During surveillance for SIV in China from 2006 to 2009, seven isolates (24.14%) of 29 influenza A viruses were co-isolated with Stenotrophomonas maltophilia from nasal and tracheal swab samples of pigs. Antimicrobial susceptibility testing showed that the bacteria possessed a high level of resistance towards clinically used antibiotics. To investigate the interaction between these two microorganisms in influencing viral susceptibility and transmission in humans, guinea pigs were used as an infection model. Animals were inoculated with SIV or S. maltophilia alone or co-infected with SIV and S. maltophilia. The results showed that although no transmission among guinea pigs was observed, virusbacteria co-infections resulted in higher virus titers in nasal washes and trachea and a longer virus shedding period. Conclusions This is the first report of influenza virus co-infection with S. maltophilia in the Chinese swine population. Increased replication of virus by co-infection with multidrug resistant bacteria might increase the infection rate of SIV in humans. The control of S. maltophilia in clinics will contribute to reducing the spread of SIV in pigs and humans. PMID:22913775

  3. Phenotypic Heterogeneity Affects Stenotrophomonas maltophilia K279a Colony Morphotypes and β-Lactamase Expression.

    PubMed

    Abda, Ebrahim M; Krysciak, Dagmar; Krohn-Molt, Ines; Mamat, Uwe; Schmeisser, Christel; Förstner, Konrad U; Schaible, Ulrich E; Kohl, Thomas A; Nieman, Stefan; Streit, Wolfgang R

    2015-01-01

    Phenotypic heterogeneity at the cellular level in response to various stresses, e.g., antibiotic treatment has been reported for a number of bacteria. In a clonal population, cell-to-cell variation may result in phenotypic heterogeneity that is a mechanism to survive changing environments including antibiotic therapy. Stenotrophomonas maltophilia has been frequently isolated from cystic fibrosis patients, can cause numerous infections in other organs and tissues, and is difficult to treat due to antibiotic resistances. S. maltophilia K279a produces the L1 and L2 β-lactamases in response to β-lactam treatment. Here we report that the patient isolate S. maltophilia K279a diverges into cellular subpopulations with distinct but reversible morphotypes of small and big colonies when challenged with ampicillin. This observation is consistent with the formation of elongated chains of bacteria during exponential growth phase and the occurrence of mainly rod-shaped cells in liquid media. RNA-seq analysis of small versus big colonies revealed differential regulation of at least seven genes among the colony morphotypes. Among those, bla L1 and bla L2 were transcriptionally the most strongly upregulated genes. Promoter fusions of bla L1 and bla L2 genes indicated that expression of both genes is also subject to high levels of phenotypic heterogeneous expression on a single cell level. Additionally, the comE homolog was found to be differentially expressed in homogenously versus heterogeneously bla L2 expressing cells as identified by RNA-seq analysis. Overexpression of comE in S. maltophilia K279a reduced the level of cells that were in a bla L2-ON mode to 1% or lower. Taken together, our data provide strong evidence that S. maltophilia K279a populations develop phenotypic heterogeneity in an ampicillin challenged model. This cellular variability is triggered by regulation networks including bla L1, bla L2, and comE. PMID:26696982

  4. Phenotypic Heterogeneity Affects Stenotrophomonas maltophilia K279a Colony Morphotypes and β-Lactamase Expression

    PubMed Central

    Abda, Ebrahim M.; Krysciak, Dagmar; Krohn-Molt, Ines; Mamat, Uwe; Schmeisser, Christel; Förstner, Konrad U.; Schaible, Ulrich E.; Kohl, Thomas A.; Nieman, Stefan; Streit, Wolfgang R.

    2015-01-01

    Phenotypic heterogeneity at the cellular level in response to various stresses, e.g., antibiotic treatment has been reported for a number of bacteria. In a clonal population, cell-to-cell variation may result in phenotypic heterogeneity that is a mechanism to survive changing environments including antibiotic therapy. Stenotrophomonas maltophilia has been frequently isolated from cystic fibrosis patients, can cause numerous infections in other organs and tissues, and is difficult to treat due to antibiotic resistances. S. maltophilia K279a produces the L1 and L2 β-lactamases in response to β-lactam treatment. Here we report that the patient isolate S. maltophilia K279a diverges into cellular subpopulations with distinct but reversible morphotypes of small and big colonies when challenged with ampicillin. This observation is consistent with the formation of elongated chains of bacteria during exponential growth phase and the occurrence of mainly rod-shaped cells in liquid media. RNA-seq analysis of small versus big colonies revealed differential regulation of at least seven genes among the colony morphotypes. Among those, blaL1 and blaL2 were transcriptionally the most strongly upregulated genes. Promoter fusions of blaL1 and blaL2 genes indicated that expression of both genes is also subject to high levels of phenotypic heterogeneous expression on a single cell level. Additionally, the comE homolog was found to be differentially expressed in homogenously versus heterogeneously blaL2 expressing cells as identified by RNA-seq analysis. Overexpression of comE in S. maltophilia K279a reduced the level of cells that were in a blaL2-ON mode to 1% or lower. Taken together, our data provide strong evidence that S. maltophilia K279a populations develop phenotypic heterogeneity in an ampicillin challenged model. This cellular variability is triggered by regulation networks including blaL1, blaL2, and comE. PMID:26696982

  5. Comparison of two multimetal resistant bacterial strains: Enterobacter sp. YSU and Stenotrophomonas maltophilia ORO2.

    PubMed

    Holmes, Andrew; Vinayak, Anubhav; Benton, Cherise; Esbenshade, Aaron; Heinselman, Carlisle; Frankland, Daniel; Kulkarni, Samatha; Kurtanich, Adrienne; Caguiat, Jonathan

    2009-11-01

    The Y-12 plant in Oak Ridge, TN, which manufactured nuclear weapons during World War II and the Cold War, contaminated East Fork Poplar Creek with heavy metals. The multimetal resistant bacterial strain, Stenotrophomonas maltophilia Oak Ridge strain O2 (S. maltophilia O2), was isolated from East Fork Poplar Creek. Sequence analysis of 16s rDNA suggested that our working strain of S. maltophilia O2 was a strain of Enterobacter. Phylogenetic tree analysis and biochemical tests confirmed that it belonged to an Enterobacter species. This new strain was named Enterobacter sp. YSU. Using a modified R3A growth medium, R3A-Tris, the Hg(II), Cd(II), Zn(II), Cu(II), Au(III), Cr(VI), Ag(I), As(III), and Se(IV) MICs for a confirmed strain of S. maltophilia O2 were 0.24, 0.33, 5, 5, 0.25, 7, 0.03, 14, and 40 mM, respectively, compared to 0.07, 0.24, 0.8, 3, 0.05, 0.4, 0.08, 14, and 40 mM, respectively, for Enterobacter sp. YSU. Although S. maltophilia O2 was generally more metal resistant than Enterobacter sp. YSU, in comparison to Escherichia coli strain HB101, Enterobacter sp. YSU was resistant to Hg(II), Cd(II), Zn(II), Au(III), Ag(I), As(III), and Se(IV). By studying metal resistances in these two strains, it may be possible to understand what makes one microorganism more metal resistant than another microorganism. This work also provided benchmark MICs that can be used to evaluate the metal resistance properties of other bacterial isolates from East Fork Poplar Creek and other metal contaminated sites. PMID:19688378

  6. Removal of cadmium by bioflocculant produced by Stenotrophomonas maltophilia using phenol-containing wastewater.

    PubMed

    Chen, Honggao; Zhong, Chunying; Berkhouse, Hudson; Zhang, Youlang; Lv, Yao; Lu, Wanyu; Yang, Yongbing; Zhou, Jiangang

    2016-07-01

    Bioflocculants have been applied in numerous applications including heavy metals removal. A major bottleneck for commercial application of bioflocculant is its high production cost. Phenol-containing wastewater are abundantly available. However, the toxic phenol inhibited the microbial activities in the subsequent fermentation processes. Consequently, strains that can secrete phenol-degrading enzymes and simultaneously produce bioflocculants through directly degrading the phenol are of academic and practical interests. A phenol-degrading strain, Stenotrophomonas maltophilia ZZC-06, which can produce the bioflocculant MBF-06 using phenol-containing wastewater, was isolated in this study. The effects of culture conditions including initial pH, dissolved oxygen, phenol concentration, inoculum size, and temperature on MBF-06 production were analyzed. The experimental results showed that over 90% flocculating activity was achieved when the phenol was used as a carbon source and 4.99 g/L of MBF-06 was achieved under the optimized condition: 2.0% dissolved oxygen, 800 mg/L phenol concentration, 10% inoculum size, an initial pH of 6.0, and a temperature of 30 °C. The bioflocculant MBF-06 contained 71.2% polysaccharides and 27.9% proteins. The feasibility of cadmium removal using MBF-06 was evaluated. The highest flocculating efficiency for cadmium was 81.43%. This study shows for the first time that Stenotrophomonas maltophilia ZZC-06 can directly convert phenol into a bioflocculant, which can be used to effectively remove cadmium. PMID:27108374

  7. Occurrence of Stenotrophomonas maltophilia in agricultural soils and antibiotic resistance properties.

    PubMed

    Deredjian, Amélie; Alliot, Nolwenn; Blanchard, Laurine; Brothier, Elisabeth; Anane, Makram; Cambier, Philippe; Jolivet, Claudy; Khelil, Mohamed Naceur; Nazaret, Sylvie; Saby, Nicolas; Thioulouse, Jean; Favre-Bonté, Sabine

    2016-05-01

    The occurrence of Stenotrophomonas maltophilia was monitored in organic amendments and agricultural soils from various sites in France and Tunisia. S. maltophilia was detected in horse and bovine manures, and its abundance ranged from 0.294 (±0.509) × 10(3) to 880 (±33.4) × 10(3) CFU (g drywt)(-1) of sample. S. maltophilia was recovered from most tested soil samples (104/124). Its abundance varied from 0.33 (±0.52) to 414 (±50) × 10(3) CFU (g drywt)(-1) of soil and was not related to soil characteristics. Antibiotic resistance properties of a set of environmental strains were compared to a clinical set, and revealed a high diversity of antibiotic resistance profiles, given both the numbers of resistance and the phenotypes. Manure strains showed resistance phenotypes, with most of the strains resisting between 7 and 9 antibiotics. While French soil strains were sensitive to most antibiotics tested, some Tunisian strains displayed resistance phenotypes close to those of clinical French strains. Screening for metal resistance among 66 soil strains showed a positive relationship between antibiotic and metal resistance. However, the prevalence of antibiotic resistance phenotypes in the studied sites was not related to the metal content in soil samples. PMID:26774914

  8. Interplay between intrinsic and acquired resistance to quinolones in Stenotrophomonas maltophilia.

    PubMed

    García-León, Guillermo; Salgado, Fabiola; Oliveros, Juan Carlos; Sánchez, María Blanca; Martínez, José Luis

    2014-05-01

    To analyse whether the mutation-driven resistance-acquisition potential of a given bacterium might be a function of its intrinsic resistome, quinolones were used as selective agents and Stenotrophomonas maltophilia was chosen as a bacterial model. S. maltophilia has two elements - SmQnr and SmeDEF - that are important in intrinsic resistance to quinolones. Using a battery of mutants in which either or both of these elements had been removed, the apparent mutation frequency for quinolone resistance and the phenotype of the selected mutants were found to be related to the intrinsic resistome and also depended on the concentration of the selector. Most mutants had phenotypes compatible with the overexpression of multidrug efflux pump(s); SmeDEF overexpression was the most common cause of quinolone resistance. Whole genome sequencing showed that mutations of the SmeRv regulator, which result in the overexpression of the efflux pump SmeVWX, are the cause of quinolone resistance in mutants not overexpressing SmeDEF. These results indicate that the development of mutation-driven antibiotic resistance is highly dependent on the intrinsic resistome, which, at least for synthetic antibiotics such as quinolones, did not develop as a response to the presence of antibiotics in the natural ecosystems in which S. maltophilia evolved. PMID:24447641

  9. The contribution of class 1 integron to antimicrobial resistance in Stenotrophomonas maltophilia.

    PubMed

    Huang, Yi-Wei; Hu, Rouh-Mei; Lin, Yi-Tsung; Huang, Hsin-Hui; Yang, Tsuey-Ching

    2015-02-01

    Two hundred clinical isolates of Stenotrophomonas maltophilia were examined for the presence of class 1 integron and for the susceptibility to 12 different antimicrobials and detergents. The prevalence of class 1 integron in S. maltophilia isolates was 11%. The class 1 integron-positive isolates exhibited a higher resistance to kanamycin, tobramycin, and trimethoprim-sulfamethoxazole (SXT) than the class 1 integron-negative ones. Polymerase chain reaction (PCR), amplifying the variable region of the class 1 integron, showed the existence of six different amplicon sizes, indicating that there are at least six different class 1 integrons distributed in the 23 class 1 integron-positive isolates. Sequence analysis of six representative PCR amplicons revealed that qacK, aac(6')-Ib', qacK-aac(6')-Ib, qacK-aac(6')-Ib-aac(6')-Ib, and qacL-aadB-cmlA-aadA2 were identified in the 550-, 800-, 1,200-, 1,800, and 3,600-bp amplicons, respectively. The sequence analysis of the 150-bp PCR amplicon demonstrated no additional resistance-associated genes except the basic genetic elements of class 1 integron. The impact of class 1 integron acquisition on the antimicrobials susceptibility was assayed by isogenic integron deletion mutant construction and the susceptibility test. The most significant contribution of the class 1 integron acquisition to S. maltophilia is the increased resistance to SXT. PMID:25243757

  10. Infections Caused by Stenotrophomonas maltophilia in Recipients of Hematopoietic Stem Cell Transplantation.

    PubMed

    Al-Anazi, Khalid Ahmed; Al-Jasser, Asma M

    2014-01-01

    Stenotrophomonas maltophilia (S. maltophilia) is a globally emerging Gram-negative bacillus that is widely spread in environment and hospital equipment. Recently, the incidence of infections caused by this organism has increased, particularly in patients with hematological malignancy and in recipients of hematopoietic stem cell transplantation (HSCT) having neutropenia, mucositis, diarrhea, central venous catheters or graft versus host disease and receiving intensive cytotoxic chemotherapy, immunosuppressive therapy, or broad-spectrum antibiotics. The spectrum of infections in HSCT recipients includes pneumonia, urinary tract and surgical site infection, peritonitis, bacteremia, septic shock, and infection of indwelling medical devices. The organism exhibits intrinsic resistance to many classes of antibiotics including carbapenems, aminoglycosides, most of the third-generation cephalosporins, and other β-lactams. Despite the increasingly reported drug resistance, trimethoprim-sulfamethoxazole is still the drug of choice. However, the organism is still susceptible to ticarcillin-clavulanic acid, tigecycline, fluoroquinolones, polymyxin-B, and rifampicin. Genetic factors play a significant role not only in evolution of drug resistance but also in virulence of the organism. The outcome of patients having S. maltophilia infections can be improved by: using various combinations of novel therapeutic agents and aerosolized aminoglycosides or colistin, prompt administration of in vitro active antibiotics, removal of possible sources of infection such as infected indwelling intravascular catheters, and application of strict infection control measures. PMID:25202682

  11. Genotyping of Environmental and Clinical Stenotrophomonas maltophilia Isolates and their Pathogenic Potential

    PubMed Central

    Adamek, Martina; Overhage, Jörg; Bathe, Stephan; Winter, Josef; Fischer, Reinhard; Schwartz, Thomas

    2011-01-01

    Stenotrophomonas maltophilia is a highly versatile species with useful biotechnological potential but also with pathogenic properties. In light of possible differences in virulence characteristics, knowledge about genomic subgroups is therefore desirable. Two different genotyping methods, rep-PCR fingerprinting and partial gyrB gene sequencing were used to elucidate S. maltophilia intraspecies diversity. Rep-PCR fingerprinting revealed the presence of 12 large subgroups, while gyrB gene sequencing distinguished 10 subgroups. For 8 of them, the same strain composition was shown with both typing methods. A subset of 59 isolates representative for the gyrB groups was further investigated with regards to their pathogenic properties in a virulence model using Dictyostelium discoideum and Acanthamoeba castellanii as host organisms. A clear tendency towards accumulation of virulent strains could be observed for one group with A. castellanii and for two groups with D. discoideum. Several virulent strains did not cluster in any of the genetic groups, while other groups displayed no virulence properties at all. The amoeba pathogenicity model proved suitable in showing differences in S. maltophilia virulence. However, the model is still not sufficient to completely elucidate virulence as critical for a human host, since several strains involved in human infections did not show any virulence against amoeba. PMID:22110692

  12. Draft Genome Sequences of Acinetobacter parvus CM11, Acinetobacter radioresistens CM38, and Stenotrophomonas maltophilia BR12, Isolated from Murine Proximal Colonic Tissue

    PubMed Central

    Saffarian, Azadeh; Mulet, Céline; Naito, Tomoaki; Bouchier, Christiane; Tichit, Magali; Ma, Laurence; Grompone, Gianfranco

    2015-01-01

    Here, we report three genome sequences of bacteria isolated from murine proximal colonic tissue and identified as Acinetobacter parvus CM11, Acinetobacter radioresistens CM38, and Stenotrophomonas maltophilia BR12. PMID:26472823

  13. Draft Genome Sequences of Acinetobacter parvus CM11, Acinetobacter radioresistens CM38, and Stenotrophomonas maltophilia BR12, Isolated from Murine Proximal Colonic Tissue.

    PubMed

    Saffarian, Azadeh; Mulet, Céline; Naito, Tomoaki; Bouchier, Christiane; Tichit, Magali; Ma, Laurence; Grompone, Gianfranco; Sansonetti, Philippe J; Pédron, Thierry

    2015-01-01

    Here, we report three genome sequences of bacteria isolated from murine proximal colonic tissue and identified as Acinetobacter parvus CM11, Acinetobacter radioresistens CM38, and Stenotrophomonas maltophilia BR12. PMID:26472823

  14. Expression and Functions of CreD, an Inner Membrane Protein in Stenotrophomonas maltophilia

    PubMed Central

    Huang, Hsin-Hui; Lin, Yi-Tsung; Chen, Wei-Ching; Huang, Yi-Wei; Chen, Shiang-Jiuun; Yang, Tsuey-Ching

    2015-01-01

    CreBC is a highly conserved two-component regulatory system (TCS) in several gram-negative bacteria, including Escherichia coli, Aeromonas spp., Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. CreD is a conserved gene that encodes a predicted inner-membrane protein and is located near the creBC loci. Activation of CreBC increases creD expression; therefore, creD expression is generally used as a measure of CreBC activation in E. coli, Aeromonas spp., and P. aeruginosa systems. In this article, we aim to elucidate the expression of creD and further to investigate its functions in S. maltophilia. In spite of a short intergenic region of 81 bp between creBC and creD, creD is expressed separately from the adjacent creBC operon and from a promoter immediately upstream of creD (PcreD) in S. maltophilia. We found that the promoter activity of PcreD is negatively regulated by the creBC TCS, positively regulated by the bacterial culture density, and not affected by β-lactams. Furthermore, creD expression is not significantly altered in the presence of the phosphor-mimic variant of CreB, CreB(D55E), which mimics activated CreB. The functions of CreD of S. maltophilia were assessed by comparison among the following: wild-type KJ; the creD isogenic mutant, KJΔCreD; and the complementary strain, KJΔCreD(pCreD). The mutant lacking creD had cell division defects and aberrations in cell envelope integrity, which then triggered the σE-mediated envelope stress response. Thus, the results indicated that CreD plays a critical role in the maintenance of envelope integrity. PMID:26698119

  15. Iron is a signal for Stenotrophomonas maltophilia biofilm formation, oxidative stress response, OMPs expression, and virulence

    PubMed Central

    García, Carlos A.; Alcaraz, Eliana S.; Franco, Mirta A.; Passerini de Rossi, Beatriz N.

    2015-01-01

    Stenotrophomonas maltophilia is an emerging nosocomial pathogen. In many bacteria iron availability regulates, through the Fur system, not only iron homeostasis but also virulence. The aim of this work was to assess the role of iron on S. maltophilia biofilm formation, EPS production, oxidative stress response, OMPs regulation, quorum sensing (QS), and virulence. Studies were done on K279a and its isogenic fur mutant F60 cultured in the presence or absence of dipyridyl. This is the first report of spontaneous fur mutants obtained in S. maltophilia. F60 produced higher amounts of biofilms than K279a and CLSM analysis demonstrated improved adherence and biofilm organization. Under iron restricted conditions, K279a produced biofilms with more biomass and enhanced thickness. In addition, F60 produced higher amounts of EPS than K279a but with a similar composition, as revealed by ATR-FTIR spectroscopy. With respect to the oxidative stress response, MnSOD was the only SOD isoenzyme detected in K279a. F60 presented higher SOD activity than the wt strain in planktonic and biofilm cultures, and iron deprivation increased K279a SOD activity. Under iron starvation, SDS-PAGE profile from K279a presented two iron-repressed proteins. Mass spectrometry analysis revealed homology with FepA and another putative TonB-dependent siderophore receptor of K279a. In silico analysis allowed the detection of potential Fur boxes in the respective coding genes. K279a encodes the QS diffusible signal factor (DSF). Under iron restriction K279a produced higher amounts of DSF than under iron rich condition. Finally, F60 was more virulent than K279a in the Galleria mellonella killing assay. These results put in evidence that iron levels regulate, likely through the Fur system, S. maltophilia biofilm formation, oxidative stress response, OMPs expression, DSF production and virulence. PMID:26388863

  16. Spectroscopic identification of AZT derivative obtained from biotransformation of AZT by Stenotrophomonas maltophilia

    NASA Astrophysics Data System (ADS)

    Kruszewska, Hanna; Chmielowiec, Urszula; Bednarek, Elżbieta; Witowska-Jarosz, Janina; Dobrowolski, Jan Cz.; Misicka, Aleksandra

    2003-06-01

    The 3'-azido-2',3'-dideoxy-β-ribosylthymine (AZT, Zidovudine) is a cytostatic antivirial drug worldwide used in AIDS treatment or, in combination with other antiproliferative drugs, in treatment of cancer. About 30-40% of AZT is metabolised by conjunction with glucuronic acid in liver and about 70% is eliminated untouched by urinary system. In this work a possible fate of the AZT in the environment is studied. To this end, a product of AZT biotransformation by an environmental strain, Stenotrophomonas maltophilia, (aerobic, Gram(-) rod, common in soil and water) is found and isolated by HPLC and TLC techniques and identified by NMR and mass spectroscopy. All the molecular spectroscopy methods confirm presence of the product, which is AZT molecule hydroxylated in the position 2' of the deoxyribose ring.

  17. Inactivation of Lytic Transglycosylases Increases Susceptibility to Aminoglycosides and Macrolides by Altering the Outer Membrane Permeability of Stenotrophomonas maltophilia.

    PubMed

    Wu, Chao-Jung; Huang, Yi-Wei; Lin, Yi-Tsung; Yang, Tsuey-Ching

    2016-05-01

    Stenotrophomonas maltophilia harbors six lytic transglycosylases (LTs): mltA, mltB1, mltB2, mltD1, mltD2, and slt LT deletion increased susceptibility of S. maltophilia to aminoglycosides (AGs) and macrolides, and the underlying mechanisms were investigated. The expression of AG-modifying enzymes and efflux pumps was evaluated by quantitative reverse transcription-PCR (qRT-PCR). Susceptibility to 1-N-phenylnaphthylamine, vancomycin, SDS, and bile salts was measured to assess outer membrane permeability. In conclusion, increased outer membrane permeability contributes to LT deletion-mediated increase in aminoglycoside and macrolide susceptibility. PMID:26976867

  18. Whole-genome sequencing identifies emergence of a quinolone resistance mutation in a case of Stenotrophomonas maltophilia bacteremia.

    PubMed

    Pak, Theodore R; Altman, Deena R; Attie, Oliver; Sebra, Robert; Hamula, Camille L; Lewis, Martha; Deikus, Gintaras; Newman, Leah C; Fang, Gang; Hand, Jonathan; Patel, Gopi; Wallach, Fran; Schadt, Eric E; Huprikar, Shirish; van Bakel, Harm; Kasarskis, Andrew; Bashir, Ali

    2015-11-01

    Whole-genome sequences for Stenotrophomonas maltophilia serial isolates from a bacteremic patient before and after development of levofloxacin resistance were assembled de novo and differed by one single-nucleotide variant in smeT, a repressor for multidrug efflux operon smeDEF. Along with sequenced isolates from five contemporaneous cases, they displayed considerable diversity compared against all published complete genomes. Whole-genome sequencing and complete assembly can conclusively identify resistance mechanisms emerging in S. maltophilia strains during clinical therapy. PMID:26324280

  19. The optimization of fermentation conditions and enzyme properties of Stenotrophomonas maltophilia for protease production.

    PubMed

    Wang, Zaigui; Sun, Linghong; Cheng, Jia; Liu, Chaoliang; Tang, Xiangfang; Zhang, Hongfu; Liu, Ying

    2016-03-01

    Intestinal bacteria play a significant physiological role in silkworms. Proteases secreted by intestinal microbes can promote the digestion of the nutrient by Bombyx mori and the absorption of mulberry leaves. Intestinal bacteria from Jingsong × Haoyue in the fourth larvae were isolated and purified to obtain high activity protease-producing bacteria. The morphology of the identified bacterial colony was examined by microscopy combined with the 16S rDNA method. The results showed that this bacterium was Gram negative and that it belonged to Stenotrophomonas maltophilia, which produces the proteases. To improve the utilization rate of these proteases, we studied the proper culture conditions for producing proteases, and we further studied the properties of the proteases that were produced. The results showed that the optimal enzyme-producing conditions were as follows: pH of 7.0, culture temperature of 35 °C, incubation time of 36 H, and outfit fluid amount of 60 mL per 100 mL. Meanwhile, the properties of the preliminary enzyme purification indicated that the best pH of the enzymes was 9.0 and the optimal reaction temperature was 50 °C. The enzymes are alkaline proteases that show satisfactory stability at 30 °C and pH 9.0. Consequently, it is suitable for the proteases secreted by S. maltophilia to play a bioactive role in the silkworm gut. PMID:25656812

  20. Effects of green tea compound epigallocatechin-3-gallate against Stenotrophomonas maltophilia infection and biofilm.

    PubMed

    Vidigal, Pedrina G; Müsken, Mathias; Becker, Katrin A; Häussler, Susanne; Wingender, Jost; Steinmann, Eike; Kehrmann, Jan; Gulbins, Erich; Buer, Jan; Rath, Peter Michael; Steinmann, Jörg

    2014-01-01

    We investigated the in vitro and in vivo activities of epigallocatechin-3-gallate (EGCg), a green tea component, against Stenotrophomonas maltophilia (Sm) isolates from cystic fibrosis (CF) patients. In vitro effects of EGCg and the antibiotic colistin (COL) on growth inhibition, survival, and also against young and mature biofilms of S. maltophilia were determined. Qualitative and quantitative changes on the biofilms were assessed by confocal laser scanning microscopy (CLSM). Further, in vivo effects of nebulized EGCg in C57BL/6 and Cftr mutant mice during acute Sm lung infection were evaluated. Subinhibitory concentrations of EGCg significantly reduced not only biofilm formation, but also the quantity of viable cells in young and mature biofilms. CLSM showed that EGCg-exposed biofilms exhibited either a change in total biofilm biovolume or an increase of the fraction of dead cells contained within the biofilm in a dose depended manner. Sm infected wild-type and Cftr mutant mice treated with 1,024 mg/L EGCg by inhalation exhibited significantly lower bacterial counts than those undergoing no treatment or treated with COL. EGCg displayed promising inhibitory and anti-biofilm properties against CF Sm isolates in vitro and significantly reduced Sm bacterial counts in an acute infection model with wild type and CF mice. This natural compound may represent a novel therapeutic agent against Sm infection in CF. PMID:24690894

  1. A Polysaccharide Lyase from Stenotrophomonas maltophilia with a Unique, pH-regulated Substrate Specificity*

    PubMed Central

    MacDonald, Logan C.; Berger, Bryan W.

    2014-01-01

    Polysaccharide lyases (PLs) catalyze the depolymerization of anionic polysaccharides via a ?-elimination mechanism. PLs also play important roles in microbial pathogenesis, participating in bacterial invasion and toxin spread into the host tissue via degradation of the host extracellular matrix, or in microbial biofilm formation often associated with enhanced drug resistance. Stenotrophomonas maltophilia is a Gram-negative bacterium that is among the emerging multidrug-resistant organisms associated with chronic lung infections as well as with cystic fibrosis patients. A putative alginate lyase (Smlt1473) from S. maltophilia was heterologously expressed in Escherichia coli, purified in a one-step fashion via affinity chromatography, and activity as well as specificity determined for a range of polysaccharides. Interestingly, Smlt1473 catalyzed the degradation of not only alginate, but poly-?-d-glucuronic acid and hyaluronic acid as well. Furthermore, the pH optimum for enzymatic activity is substrate-dependent, with optimal hyaluronic acid degradation at pH 5, poly-?-d-glucuronic acid degradation at pH 7, and alginate degradation at pH 9. Analysis of the degradation products revealed that each substrate was cleaved endolytically into oligomers comprised predominantly of even numbers of sugar groups, with lower accumulation of trimers and pentamers. Collectively, these results imply that Smlt1473 is a multifunctional PL that exhibits broad substrate specificity, but utilizes pH as a mechanism to achieve selectivity. PMID:24257754

  2. High Genetic Diversity among Stenotrophomonas maltophilia Strains Despite Their Originating at a Single Hospital

    PubMed Central

    Valdezate, Sylvia; Vindel, Ana; Martín-Dávila, Pilar; Del Saz, Begoña Sánchez; Baquero, Fernando; Cantón, Rafael

    2004-01-01

    The levels of genetic relatedness of 139 Stenotrophomonas maltophilia strains recovered from 105 hospitalized non-cystic fibrosis patients (51% from medical wards, 35% from intensive care units, and 14% from surgical wards) and 7 environmental sources in the same hospital setting during a 4-year period were typed by the pulsed-field gel electrophoresis (PFGE) technique. A total of 99 well-defined distinct XbaI PFGE patterns were identified (Simpson's discrimination index, 0.996). The dendrogram showed a Dice similarity coefficient ranging from 28 to 80%. Two major clusters (I and II), three minor clusters (III, IV, and V), and two independent branches were observed when using a 36% Dice coefficient, indicating a high diversity of genetic relatedness. It is of note that 84% of strains were grouped within two major clonal lineages. No special cluster gathering was found among strains belonging to the same sample type specimen, patients' infection or colonization status, and ward of precedence. Despite this fact, three different clones (A, B, and C) recovered from respiratory samples from six, three, and two patients, respectively, and two clones, D and E, in two bacteremic patients each, were identified. Isolation of an S. maltophilia strain belonging to the clone A profile in a bronchoscope demonstrated a common source from this clone. This study revealed a high genetic diversity of S. maltophilia isolates despite their origin from a single hospital, which may be related to the wide environmental distribution of this pathogen. However, few clones could be transmitted among different patients, yielding outbreak situations. PMID:14766838

  3. A Highly Thermostable Xylanase from Stenotrophomonas maltophilia: Purification and Partial Characterization

    PubMed Central

    Kumar, Sharad; Singh, Sudheer Kumar

    2013-01-01

    Seven xylanolytic bacterial strains were isolated from saw-dust dump soil. The bacterial strain X6 was selected on the basis of the highest xylanase activity with no cellulase contamination. It was identified as Stenotrophomonas maltophilia by biochemical tests and 16S rRNA gene sequencing approach. Xylanase production studies by S. maltophilia on different commercial xylans and agro-industrial residues suggested that wheat bran was the best carbon source for xylanase production (26.4 ± 0.6 IU/mL). The studies with inorganic and organic nitrogen sources suggested yeast extract as the best support for xylanase production (25 ± 0.6 IU/mL). Maximum xylanase production was observed at initial medium pH = 8.0 (23.8 ± 0.4 IU/mL) with production at pH = 7.0 and pH = 9.0 being almost comparable. Xylanase produced by S. maltophilia was purified to homogeneity using ammonium sulfate precipitation, gel filtration, and ion exchange chromatography. The final purification was 5.43-fold with recovery of 19.18%. The molecular weight of the purified xylanase protein was ~142 kDa. Both crude and purified xylanase had good stability at pH = 9.0 and 80°C with activity retention greater than 90% after 30 min incubation. The enzyme stability at high temperature and alkaline pH make it potentially effective for industrial applications. PMID:24416589

  4. Sequence analysis and enzyme kinetics of the L2 serine beta-lactamase from Stenotrophomonas maltophilia.

    PubMed Central

    Walsh, T R; MacGowan, A P; Bennett, P M

    1997-01-01

    The L2 serine active-site beta-lactamase from Stenotrophomonas maltophilia has been classified as a clavulanic acid-sensitive cephalosporinase. The gene encoding this enzyme from S. maltophilia 1275 IID has been cloned on a 3.3-kb fragment into pK18 under the control of a Ptac promoter to generate recombinant plasmid pUB5840; when expressed in Escherichia coli, this gene confers resistance to cephalosporins and penicillins. Sequence analysis has revealed an open reading frame (ORF) of 909 bp with a GC content of 71.6%, comparable to that of the L1 metallo-beta-lactamase gene (68.4%) from the same bacterium. The ORF encodes an unmodified protein of 303 amino acids with a predicted molecular mass of 31.5 kDa, accommodating a putative leader peptide of 27 amino acids. Comparison of the amino acid sequence with those of other beta-lactamases showed it to be most closely related (54% identity) to the BLA-A beta-lactamase from Yersinia enterocolitica. Sequence identity is most obvious near the STXK active-site motif and the SDN loop motif common to all serine active-site penicillinases. Sequences outside the conserved regions display low homology with comparable regions of other class A penicillinases. Kinetics of the enzyme from the cloned gene demonstrated an increase in activity with cefotaxime but markedly less activity with imipenem than previously reported. Hence, the S. maltophilia L2 beta-lactamase is an inducible Ambler class A beta-lactamase which would account for the sensitivity to clavulanic acid. PMID:9210666

  5. The inactivation of RNase G reduces the Stenotrophomonas maltophilia susceptibility to quinolones by triggering the heat shock response.

    PubMed

    Bernardini, Alejandra; Corona, Fernando; Dias, Ricardo; Sánchez, Maria B; Martínez, Jose L

    2015-01-01

    Quinolone resistance is usually due to mutations in the genes encoding bacterial topoisomerases. However, different reports have shown that neither clinical quinolone resistant isolates nor in vitro obtained Stenotrophomonas maltophilia mutants present mutations in such genes. The mechanisms so far described consist on efflux pumps' overexpression. Our objective is to get information on novel mechanisms of S. maltophilia quinolone resistance. For this purpose, a transposon-insertion mutant library was obtained in S. maltophilia D457. One mutant presenting reduced susceptibility to nalidixic acid was selected. Inverse PCR showed that the inactivated gene encodes RNase G. Complementation of the mutant with wild-type RNase G allele restored the susceptibility to quinolones. Transcriptomic and real-time RT-PCR analyses showed that several genes encoding heat-shock response proteins were expressed at higher levels in the RNase defective mutant than in the wild-type strain. In agreement with this situation, heat-shock reduces the S. maltophilia susceptibility to quinolone. We can then conclude that the inactivation of the RNase G reduces the susceptibility of S. maltophilia to quinolones, most likely by regulating the expression of heat-shock response genes. Heat-shock induces a transient phenotype of quinolone resistance in S. maltophilia. PMID:26539164

  6. The inactivation of RNase G reduces the Stenotrophomonas maltophilia susceptibility to quinolones by triggering the heat shock response

    PubMed Central

    Bernardini, Alejandra; Corona, Fernando; Dias, Ricardo; Sánchez, Maria B.; Martínez, Jose L.

    2015-01-01

    Quinolone resistance is usually due to mutations in the genes encoding bacterial topoisomerases. However, different reports have shown that neither clinical quinolone resistant isolates nor in vitro obtained Stenotrophomonas maltophilia mutants present mutations in such genes. The mechanisms so far described consist on efflux pumps’ overexpression. Our objective is to get information on novel mechanisms of S. maltophilia quinolone resistance. For this purpose, a transposon-insertion mutant library was obtained in S. maltophilia D457. One mutant presenting reduced susceptibility to nalidixic acid was selected. Inverse PCR showed that the inactivated gene encodes RNase G. Complementation of the mutant with wild-type RNase G allele restored the susceptibility to quinolones. Transcriptomic and real-time RT-PCR analyses showed that several genes encoding heat-shock response proteins were expressed at higher levels in the RNase defective mutant than in the wild-type strain. In agreement with this situation, heat-shock reduces the S. maltophilia susceptibility to quinolone. We can then conclude that the inactivation of the RNase G reduces the susceptibility of S. maltophilia to quinolones, most likely by regulating the expression of heat-shock response genes. Heat-shock induces a transient phenotype of quinolone resistance in S. maltophilia. PMID:26539164

  7. Isolation and characterization of a novel strain of Stenotrophomonas maltophilia possessing various dioxygenases for monocyclic hydrocarbon degradation

    PubMed Central

    Urszula, Guzik; Izabela, Greń; Danuta, Wojcieszyńska; Sylwia, Łabużek

    2009-01-01

    A Gram-negative bacterium, designated as strain KB2, was isolated from activated sludge and was found to utilize different aromatic substrates as sole carbon and energy source. On the basis of morphological and physiochemical characteristics and 16S rRNA gene sequence analysis, the isolated strain KB2 was identified as Stenotrophomonas maltophilia. Strain KB2 is from among different Stenotrophomonas maltophilia strains the first one described as exhibiting the activities of three types of dioxygenases depending on the structure of the inducer. The cells grown on benzoate and catechol showed mainly catechol 1,2-dioxygenase activity. The activity of 2,3-dioxygenase was detected after phenol induction. Protocatechuate 3,4-dioxygenase was found in crude cell extracts of this strain after incubation with 4-hydroxybenzoic acid, protocatechuic acid and vanillic acid. Because of broad spectrum of dioxygenases’ types that Stenotrophomonas maltophilia KB2 can exhibit, this strain appears to be very powerful and useful tool in the biotreatment of wastewaters and in soil decontamination. PMID:24031359

  8. Comparative Genomics of Environmental and Clinical Stenotrophomonas maltophilia Strains with Different Antibiotic Resistance Profiles

    PubMed Central

    Youenou, Benjamin; Favre-Bonté, Sabine; Bodilis, Josselin; Brothier, Elisabeth; Dubost, Audrey; Muller, Daniel; Nazaret, Sylvie

    2015-01-01

    Stenotrophomonas maltophilia, a ubiquitous Gram-negative γ-proteobacterium, has emerged as an important opportunistic pathogen responsible for nosocomial infections. A major characteristic of clinical isolates is their high intrinsic or acquired antibiotic resistance level. The aim of this study was to decipher the genetic determinism of antibiotic resistance among strains from different origins (i.e., natural environment and clinical origin) showing various antibiotic resistance profiles. To this purpose, we selected three strains isolated from soil collected in France or Burkina Faso that showed contrasting antibiotic resistance profiles. After whole-genome sequencing, the phylogenetic relationships of these 3 strains and 11 strains with available genome sequences were determined. Results showed that a strain’s phylogeny did not match their origin or antibiotic resistance profiles. Numerous antibiotic resistance coding genes and efflux pump operons were revealed by the genome analysis, with 57% of the identified genes not previously described. No major variation in the antibiotic resistance gene content was observed between strains irrespective of their origin and antibiotic resistance profiles. Although environmental strains generally carry as many multidrug resistant (MDR) efflux pumps as clinical strains, the absence of resistance–nodulation–division (RND) pumps (i.e., SmeABC) previously described to be specific to S. maltophilia was revealed in two environmental strains (BurA1 and PierC1). Furthermore the genome analysis of the environmental MDR strain BurA1 showed the absence of SmeABC but the presence of another putative MDR RND efflux pump, named EbyCAB on a genomic island probably acquired through horizontal gene transfer. PMID:26276674

  9. Antibiogram of Stenotrophomonas maltophilia Isolated From Nkonkobe Municipality, Eastern Cape Province, South Africa

    PubMed Central

    Adegoke, Anthony Ayodeji; Okoh, Anthony I.

    2014-01-01

    Background: Assessment of resistance genes is imperative, as they become disseminated to bacterial flora in plants and to the indigenous bacterial community, and thus ultimately contributes to the clinical problems of antibiotic resistant pathogens. Objectives: The research was to assess the antibiotic characteristics and incidence of sul3 genes of Stenotrophomonas maltophilia isolates recovered from rhizospheres plant in Nkonkobe Municipality. Materials and Methods: Identification and assessment of resistance genes (sul2 and sul3 genes) were carried out using polymerase chain reaction (PCR). Analytical profile index (API) was used for biochemical characterization for identification before the PCR. Antibiotic susceptibility test was carried out using the approved guidelines and standards of Clinical Laboratory Standard Institute (CLSI). Results: A total of 125 isolates were identified, composed of 120 (96%) from grass root rhizosphere and 5 (4%) from soil butternut root rhizosphere. In vitro antibiotic susceptibility tests showed varying resistances to meropenem (8.9%), cefuroxime (95.6 %), ampicillin-sulbactam (53.9%), ceftazidime (10.7%), cefepime (29.3 %), minocycline (2.2%), kanamycin (56.9%), ofloxacin (2.9%), levofloxacin (1.3%), moxifloxacin (2.8%), ciprofloxacin (24.3%), gatifloxacin (1.3%), polymyxin B (2.9 %), cotrimoxazole (26.1%), trimethoprim (98.6%) and aztreonam (58%). The isolates were susceptible to the fluoroquinolones (74.3-94.7%), polymycin (97.1%) and meropenem (88.1%). The newest sulphonamide resistance gene, sul3, was detected among the trimethoprim-sulfamethoxazole (cotrimoxazole)-resistant isolates, while the most frequent sulphonamide-resistant gene in animal source isolates, sul2, was not. Conclusions: The commensal S. maltophilia isolates in the Nkonkobe Municipality environment harbored the resistant gene sul3 as clinical counterparts, especially from the perspective of reservoirs of antibiotic resistance determinants. PMID:25789125

  10. Comparative Genomics of Environmental and Clinical Stenotrophomonas maltophilia Strains with Different Antibiotic Resistance Profiles.

    PubMed

    Youenou, Benjamin; Favre-Bonté, Sabine; Bodilis, Josselin; Brothier, Elisabeth; Dubost, Audrey; Muller, Daniel; Nazaret, Sylvie

    2015-09-01

    Stenotrophomonas maltophilia, a ubiquitous Gram-negative γ-proteobacterium, has emerged as an important opportunistic pathogen responsible for nosocomial infections. A major characteristic of clinical isolates is their high intrinsic or acquired antibiotic resistance level. The aim of this study was to decipher the genetic determinism of antibiotic resistance among strains from different origins (i.e., natural environment and clinical origin) showing various antibiotic resistance profiles. To this purpose, we selected three strains isolated from soil collected in France or Burkina Faso that showed contrasting antibiotic resistance profiles. After whole-genome sequencing, the phylogenetic relationships of these 3 strains and 11 strains with available genome sequences were determined. Results showed that a strain's phylogeny did not match their origin or antibiotic resistance profiles. Numerous antibiotic resistance coding genes and efflux pump operons were revealed by the genome analysis, with 57% of the identified genes not previously described. No major variation in the antibiotic resistance gene content was observed between strains irrespective of their origin and antibiotic resistance profiles. Although environmental strains generally carry as many multidrug resistant (MDR) efflux pumps as clinical strains, the absence of resistance-nodulation-division (RND) pumps (i.e., SmeABC) previously described to be specific to S. maltophilia was revealed in two environmental strains (BurA1 and PierC1). Furthermore the genome analysis of the environmental MDR strain BurA1 showed the absence of SmeABC but the presence of another putative MDR RND efflux pump, named EbyCAB on a genomic island probably acquired through horizontal gene transfer. PMID:26276674

  11. Decoding the genetic and functional diversity of the DSF quorum-sensing system in Stenotrophomonas maltophilia

    PubMed Central

    Huedo, Pol; Yero, Daniel; Martinez-Servat, Sònia; Ruyra, Àngels; Roher, Nerea; Daura, Xavier; Gibert, Isidre

    2015-01-01

    Stenotrophomonas maltophilia uses the Diffusible Signal Factor (DSF) quorum sensing (QS) system to mediate intra- and inter-specific signaling and regulate virulence-related processes. The components of this system are encoded by the rpf cluster, with genes rpfF and rpfC encoding for the DSF synthase RpfF and sensor RpfC, respectively. Recently, we have shown that there exist two variants of the rpf cluster (rpf-1 and rpf-2), distinguishing two groups of S. maltophilia strains. Surprisingly, only rpf-1 strains produce detectable DSF, correlating with their ability to control biofilm formation, swarming motility and virulence. The evolutive advantage of acquiring two different rpf clusters, the phylogenetic time point and mechanism of this acquisition and the conditions that activate DSF production in rpf-2 strains, are however not known. Examination of this cluster in various species suggests that its variability originated most probably by genetic exchange between rhizosphere bacteria. We propose that rpf-2 variant strains make use of a strategy recently termed as “social cheating.” Analysis of cellular and extracellular fatty acids (FAs) of strains E77 (rpf-1) and M30 (rpf-2) suggests that their RpfFs have also a thioesterase activity that facilitates the release of unspecific FAs to the medium in addition to DSF. Production of DSF in rpf-1 strains appears in fact to be modulated by some of these extracellular FAs in addition to other factors such as temperature and nutrients, while in rpf-2 strains DSF biosynthesis is derepressed only upon detection of DSF itself, suggesting that they require cohabitation with DSF-producer bacteria to activate their DSF regulatory machinery. Finally, we show that the mixed rpf-1/rpf-2 population presents synergism in DSF production and virulence capacity in an in vivo infection model. Recovery and quantification of DSF from co-infected animals correlates with the observed mortality rate. PMID:26284046

  12. Aflatoxin B(1) degradation by Stenotrophomonas maltophilia and other microbes selected using coumarin medium.

    PubMed

    Guan, Shu; Ji, Cheng; Zhou, Ting; Li, Junxia; Ma, Qiugang; Niu, Tiangui

    2008-08-01

    Aflatoxin B(1) (AFB(1)) is one of the most harmful mycotoxins in animal production and food industry. A safe, effective and environmentally sound detoxification method is needed for controlling this toxin. In this study, 65 samples were screened from various sources with vast microbial populations using a newly developed medium containing coumarin as the sole carbon source. Twenty five single-colony bacterial isolates showing AFB(1) reduction activity in a liquid culture medium were selected from the screen. Isolate 35-3, obtained from tapir feces and identified to be Stenotrophomonas maltophilia, reduced AFB(1) by 82.5% after incubation in the liquid medium at 37 degrees C for 72 h. The culture supernatant of isolate 35-3 was able to degrade AFB(1) effectively, whereas the viable cells and cell extracts were far less effective. Factors influencing AFB(1) degradation by the culture supernatant were investigated. Activity was reduced to 60.8% and 63.5% at 20 degrees C and 30 degrees C, respectively, from 78.7% at 37 degrees C. The highest degradation rate was 84.8% at pH 8 and the lowest was only 14.3% at pH 4.0. Ions Mg(2+) and Cu(2+) were activators for AFB(1) degradation, however ion Zn(2+) was a strong inhibitor. Treatments with proteinase K, proteinase K plus SDS and heating significantly reduced or eradicated the degradation activity of the culture supernatant. The results indicated that the degradation of AFB(1) by S. maltophilia 35-3 was enzymatic and could have a great potential in industrial applications. PMID:19325817

  13. Insights into the degradation of chlorimuron-ethyl by Stenotrophomonas maltophilia D310-3.

    PubMed

    Zang, Hailian; Yu, Qi; Lv, Tongyang; Cheng, Yi; Feng, Lu; Cheng, Xiaosong; Li, Chunyan

    2016-02-01

    In this study, the effects of cultivation conditions on the degradation of chlorimuron-ethyl by Stenotrophomonas maltophilia D310-3, which exhibits a high chlorimuron-ethyl-degrading capability, were investigated. To improve the biodegradation efficiency, the cultivation conditions were optimized using response surface methodology (RSM) based on Box-Behnken design (BBD). The maximum biodegradation rate (89.9%) was obtained at the optimal conditions (culture time, 6 d; substrate concentration, 50.21 mg L(-1); pH, 5.95; temperature, 30.15 °C). The Andrews model was used to describe the dynamic change regularity of the specific degradation rate as the substrate concentration increased, and the values of the maximum specific degradation rate (qmax), half-saturation constant (KS) and inhibition constant (Ki) were 78.87 d(-1), 9180.97 mg L(-1) and 0.28 mg L(-1), respectively. Eight degradation products were captured and identified by liquid chromatography-mass spectrometry (LC-MS) and Fourier transform infrared (FTIR) spectrometry, and three possible degradation pathways are proposed based on the results of high-performance liquid chromatography (HPLC), LC-MS and FTIR analyses as well as results reported in relevant literature. To the best of our knowledge, this is the first systematic study of the degradation pathway of chlorimuron-ethyl by S. maltophilia D310-3. This study provides valuable information for further exploration of the microbial degradation of other sulfonylurea herbicides. PMID:26363318

  14. Concomitant presence of Aspergillus fumigatus and Stenotrophomonas maltophilia in the respiratory tract: a new risk for patients with liver disease?

    PubMed

    Cabaret, Odile; Bonnal, Christine; Canoui-Poitrine, Florence; Emirian, Aurélie; Bizouard, Geoffray; Levesque, Eric; Maitre, Bernard; Fihman, Vincent; Decousser, Jean-Winoc; Botterel, Françoise

    2016-05-01

    Concomitant lung colonization by Aspergillus fumigatus and Stenotrophomonas maltophilia was reported mainly in patients with cystic fibrosis (CF) and immunocompromised patients. The aim of the study was to assess the frequency of co-culture of A. fumigatus and S. maltophilia in respiratory samples of hospitalized patients, and to determine its associated factors. Between 2007 and 2011, all patients who had A. fumigatus in their respiratory samples were retrospectively enrolled in the study. Their clinical and laboratory data, including the presence of S. maltophilia in a respiratory sample, were collected within the same month. Of the 257 enrolled patients (372 respiratory samples), 71 % were immunocompromised and 32 % had chronic respiratory disease. S. maltophilia was isolated within the same month in 20 patients (7.8 %). In the univariate analysis, factors associated with concomitant culture of A. fumigatus and S. maltophilia were liver disease (P = 0.009), orotracheal intubation (P = 0.001), ventilator-associated pneumonia (P = 0.006), central venous catheter (P = 0.003), parenteral nutrition (P = 0.008) and culture of Pseudomonas aeruginosa in respiratory samples (P = 0.002). In the multivariate analysis, the simultaneous presence of P. aeruginosa in the respiratory tract (odds ratio (OR) = 3.19, 95 % confidence interval (CI) 1.11-9.14, P = 0.031), liver disease (OR = 3.92, 95 % CI 1.32-11.62, P = 0.014) and orotracheal intubation (OR = 3.42, 95 % CI 1.17-9.96, P = 0.024) were independently associated with the co-culture of S. maltophilia and A. fumigatus. Factors independently associated with the concomitant culture of A. fumigatus and S. maltophilia were identified. These results support a future prospective study focusing on liver disease and its complications. PMID:26872817

  15. Purification, characterization, and gene cloning of a chitinase from Stenotrophomonas maltophilia N4.

    PubMed

    Jankiewicz, Urszula; Brzezinska, Maria Swiontek

    2015-06-01

    The Stenotrophomonas maltophilia synthesises high-activity chitinase in response to chitin or chitosan induction. The enzyme was purified 8.5 fold and subjected to characterisation. The optimum hydrolysis conditions for this enzyme when using colloidal chitin as substrate were pH 5.6 and temperature of 45 °C. The enzyme demonstrated high thermal stability at 45 °C within 2 h. The studied chitinase exhibited high activity towards colloidal chitin, glycol chitin and chitosan, while it did not hydrolyse glycosidic bonds in carboxymethylcellulose. The enzyme exhibited the highest activity, equalling 90 U/ml, towards Nitrophenyl β-D-N,N',N"-triacetylchitotriose and activity of 37 U/ml towards 4-Nitrophenyl N,N'-diacetyl-β-D-chitobioside. The K(m) value in the presence of the two former substrates was:1.2 and 3.9 mM, respectively, which classifies the studied enzyme as an endochitinase. Cysteine and 2-mercaptoethanol stimulated to a small degree the activity of the chitinase which may indicate the involvement of cysteine residues in the catalysis mechanism. The full length of the nucleotide sequence of this chitinase gene is 2106 bp, which amounts to 702 amino acids. PMID:25684706

  16. Production, characterization, gene cloning, and nematocidal activity of the extracellular protease from Stenotrophomonas maltophilia N4.

    PubMed

    Jankiewicz, Urszula; Larkowska, Ewa; Swiontek Brzezinska, Maria

    2016-06-01

    A rhizosphere strain of the bacterium Stenotrophomonas maltophilia N4 secretes the serine protease PN4, whose molecular mass is approximately 42 kDa. The optimal temperature for the enzyme activity of the 11-fold purified protein was 50°C and the optimal pH was 10.5. The activity of the enzyme was strongly inhibited by specific serine protease inhibitors, which allowed for its classification as an alkaline serine protease family. Ca(2+) ions stimulated the activity of the protease PN4, while Mg(2+) ions stabilized its activity, and Zn(2+) and Cd(2+) ions strongly inhibited its activity. The enzyme has broad substrate specificity. For example, it is able to hydrolyse casein, keratin, albumin, haemoglobin, and gelatin, as well as the insoluble modified substrates azure keratin and azocoll. The gene that encodes the 1740 bp precursor form of the enzyme (accession number: LC031815) was cloned. We then deduced that its amino acid sequence includes the region of the conserved domain of the S8 family of peptidases as well as the catalytic triad Asp/His/Ser. The bacterial culture fluid as well as the purified protease PN4 demonstrated biocidal activity with regard to the nematodes Caenorhabditis elegans and Panagrellus spp. PMID:26896861

  17. Stenotrophomonas maltophilia Encodes a Type II Protein Secretion System That Promotes Detrimental Effects on Lung Epithelial Cells

    PubMed Central

    Karaba, Sara M.; White, Richard C.

    2013-01-01

    The Gram-negative bacterium Stenotrophomonas maltophilia is increasingly identified as a multidrug-resistant pathogen, being associated with pneumonia, among other infections. Despite this increasing clinical problem, the genetic and molecular basis of S. maltophilia virulence is quite minimally defined. We now report that strain K279a, the first clinical isolate of S. maltophilia to be sequenced, encodes a functional type II protein secretion (T2S) system. Indeed, mutants of K279a that contain a mutation in the xps locus exhibit a loss of at least seven secreted proteins and three proteolytic activities. Unlike culture supernatants from the parental K279a, supernatants from multiple xps mutants also failed to induce the rounding, detachment, and death of A549 cells, a human lung epithelial cell line. Supernatants of the xps mutants were also unable to trigger a massive rearrangement in the host cell's actin cytoskeleton that was associated with K279a secretion. In all assays, a complemented xpsF mutant behaved as the wild type did, demonstrating that Xps T2S is required for optimal protein secretion and the detrimental effects on host cells. The activities that were defined as being Xps dependent in K279a were evident among other respiratory isolates of S. maltophilia. Utilizing a similar type of genetic analysis, we found that a second T2S system (Gsp) encoded by the K279a genome is cryptic under all of the conditions tested. Overall, this study represents the first examination of T2S in S. maltophilia, and the data obtained indicate that Xps T2S likely plays an important role in S. maltophilia pathogenesis. PMID:23774603

  18. Antibiotic susceptibility of sulfamethoxazole-trimethoprim resistant Stenotrophomonas maltophilia strains isolated at a tertiary care centre in Hungary.

    PubMed

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

    2015-09-01

    Sulfamethoxazole-trimethoprim (SXT) is the drug-of-choice in Stenotrophomonas maltophilia caused infections. There has been an increase in resistance to SXT of S. maltophilia over recent years. In this study 30 S. maltophilia clinical isolates resistant to SXT were investigated. Antibiotic susceptibilities for ciprofloxacin, moxifloxacin, levofloxacin, doxycycline, tigecycline, ceftazidime, colistin and chloramphenicol were determined by broth microdilution method. None of the strains were susceptible to ciprofloxacin, tigecycline, ceftazidime or colistin. Only 37% of the isolates were susceptible to levofloxacin or moxifloxacin. Two isolates resistant to all tested antibiotic agents and two others susceptible only to doxycycline were further investigated: susceptibility for combinations of antibiotics was analyzed by checkerboard technique. According to the fractional inhibitory concentration indices calculated, moxifloxacin plus ceftazidime combination was found to be synergistic in each case. Genetic testing revealed the predominance of sul1 gene. Our study concluded that the range of effective antibiotic agents is even more limited in infections caused by SXT-resistant S. maltophilia. In these cases, in vitro synergistic antibiotic combinations could be potential therapeutic options. PMID:26551572

  19. High-level quinolone resistance is associated with the overexpression of smeVWX in Stenotrophomonas maltophilia clinical isolates.

    PubMed

    García-León, G; Ruiz de Alegría Puig, C; García de la Fuente, C; Martínez-Martínez, L; Martínez, J L; Sánchez, M B

    2015-05-01

    Stenotrophomonas maltophilia is the only known bacterium in which quinolone-resistant isolates do not present mutations in the genes encoding bacterial topoisomerases. The expression of the intrinsic quinolone resistance elements smeDEF, smeVWX and Smqnr was analysed in 31 clinical S. maltophilia isolates presenting a minimum inhibitory concentration (MIC) range to ciprofloxacin between 0.5 and > 32 μg/mL; 11 (35.5%) overexpressed smeDEF, 2 (6.5%) presenting the highest quinolone MICs overexpressed smeVWX and 1 (3.2%) overexpressed Smqnr. Both strains overexpressing smeVWX presented changes at the Gly266 position of SmeRv, the repressor of smeVWX. Changes at the same position were previously observed in in vitro selected S. maltophilia quinolone-resistant mutants, indicating this amino acid is highly relevant for the activity of SmeRv in repressing smeVWX expression. For the first time SmeVWX overexpression is associated with quinolone resistance of S. maltophilia clinical isolates. PMID:25753190

  20. Stenotrophomonas maltophilia Virulence and Specific Variations in Trace Elements during Acute Lung Infection: Implications in Cystic Fibrosis

    PubMed Central

    Crocetta, Valentina; Consalvo, Ada; Zappacosta, Roberta; Di Ilio, Carmine; Di Bonaventura, Giovanni

    2014-01-01

    Metal ions are necessary for the proper functioning of the immune system, and, therefore, they might have a significant influence on the interaction between bacteria and host. Ionic dyshomeostasis has been recently observed also in cystic fibrosis (CF) patients, whose respiratory tract is frequently colonized by Stenotrophomonas maltophilia. For the first time, here we used an inductively mass spectrometry method to perform a spatial and temporal analysis of the pattern of changes in a broad range of major trace elements in response to pulmonary infection by S. maltophilia. To this, DBA/2 mouse lungs were comparatively infected by a CF strain and by an environmental one. Our results showed that pulmonary ionomic profile was significantly affected during infection. Infected mice showed increased lung levels of Mg, P, S, K, Zn, Se, and Rb. To the contrary, Mn, Fe, Co, and Cu levels resulted significantly decreased. Changes of element concentrations were correlated with pulmonary bacterial load and markers of inflammation, and occurred mostly on day 3 post-exposure, when severity of infection culminated. Interestingly, CF strain – significantly more virulent than the environmental one in our murine model - provoked a more significant impact in perturbing pulmonary metal homeostasis. Particularly, exposure to CF strain exclusively increased P and K levels, while decreased Fe and Mn ones. Overall, our data clearly indicate that S. maltophilia modulates pulmonary metal balance in a concerted and virulence-dependent manner highlighting the potential role of the element dyshomeostasis during the progression of S. maltophilia infection, probably exacerbating the harmful effects of the loss of CF transmembrane conductance regulator function. Further investigations are required to understand the biological significance of these alterations and to confirm they are specifically caused by S. maltophilia. PMID:24586389

  1. Genome Sequence of a Multidrug-Resistant Strain of Stenotrophomonas maltophilia with Carbapenem Resistance, Isolated from King Abdullah Medical City, Makkah, Saudi Arabia

    PubMed Central

    Abdel-Haleem, Alyaa M.; Rchiad, Zineb; Khan, Babar K.; Abdallah, Abdallah M.; Naeem, Raeece; Nikhat Sheerin, Shalam; Solovyev, Victor; Ahmed, Abdalla

    2015-01-01

    The emergence and spread of multidrug-resistant (MDR) bacteria have been regarded as major challenges among health care-associated infections worldwide. Here, we report the draft genome sequence of an MDR Stenotrophomonas maltophilia strain isolated in 2014 from King Abdulla Medical City, Makkah, Saudi Arabia. PMID:26472828

  2. Genome Sequence of a Multidrug-Resistant Strain of Stenotrophomonas maltophilia with Carbapenem Resistance, Isolated from King Abdullah Medical City, Makkah, Saudi Arabia.

    PubMed

    Abdel-Haleem, Alyaa M; Rchiad, Zineb; Khan, Babar K; Abdallah, Abdallah M; Naeem, Raeece; Nikhat Sheerin, Shalam; Solovyev, Victor; Ahmed, Abdalla; Pain, Arnab

    2015-01-01

    The emergence and spread of multidrug-resistant (MDR) bacteria have been regarded as major challenges among health care-associated infections worldwide. Here, we report the draft genome sequence of an MDR Stenotrophomonas maltophilia strain isolated in 2014 from King Abdulla Medical City, Makkah, Saudi Arabia. PMID:26472828

  3. Draft Genome Sequence of Stenotrophomonas maltophilia CBF10-1, an Organophosphate-Degrading Bacterium Isolated from Ranch Soil in Fairchilds, Texas.

    PubMed

    Iyer, Rupa; Damania, Ashish

    2016-01-01

    Stenotrophomonas maltophilia CBF10-1 was isolated from a ranch in Fairchilds, Texas, USA. Its genome reveals a highly adaptable microorganism with a large complement of antibiotic and heavy metal resistance genes, efflux pumps, multidrug transporters, and xenobiotic degradation pathways. PMID:27174285

  4. Draft Genome Sequence of Stenotrophomonas maltophilia CBF10-1, an Organophosphate-Degrading Bacterium Isolated from Ranch Soil in Fairchilds, Texas

    PubMed Central

    Damania, Ashish

    2016-01-01

    Stenotrophomonas maltophilia CBF10-1 was isolated from a ranch in Fairchilds, Texas, USA. Its genome reveals a highly adaptable microorganism with a large complement of antibiotic and heavy metal resistance genes, efflux pumps, multidrug transporters, and xenobiotic degradation pathways. PMID:27174285

  5. Friends or foes: can we make a distinction between beneficial and harmful strains of the Stenotrophomonas maltophilia complex?

    PubMed Central

    Berg, Gabriele; Martinez, Jose L.

    2015-01-01

    Stenotrophomonas maltophilia is an emerging multi-drug-resistant global opportunistic pathogen of environmental, mainly plant-associated origin. It is also used as a biocontrol or stress protecting agent for crops in sustainable agricultural as well as in bioremediation strategies. In order to establish effective protocols to distinguish harmless from harmful strains, our discussion must take into consideration the current data available surrounding the ecology, evolution and pathogenicity of the species complex. The mutation rate was identified as one of several possible criteria for strain plasticity, but it is currently impossible to distinguish beneficial from harmful S. maltophilia strains. This may compromise the possibility of the release and application for environmental biotechnology of this bacterial species. The close relative S. rhizophila, which can be clearly differentiated from S. maltophilia, provides a harmless alternative for biotechnological applications without human health risks. This is mainly because it is unable to growth at the human body temperature, 37∘C due to the absence of heat shock genes and a potentially temperature-regulated suicide mechanism. PMID:25873912

  6. Molecular Epidemiology of Stenotrophomonas maltophilia Isolated from Clinical Specimens from Patients with Cystic Fibrosis and Associated Environmental Samples

    PubMed Central

    Denton, Miles; Todd, Neil J.; Kerr, Kevin G.; Hawkey, Peter M.; Littlewood, James M.

    1998-01-01

    Stenotrophomonas maltophilia was isolated from the respiratory tracts of 41 (25%) of 163 children attending our pediatric cystic fibrosis unit between September 1993 and December 1995. The extents of S. maltophilia contamination of environmental sites frequented by these patients were investigated with a selective medium incorporating vancomycin, imipenem, and amphotericin B. Eighty-two isolates of S. maltophilia were cultured from 67 different environmental sites sampled between January and July 1996. The organism was widespread in the home environment, with 20 (36%) and 25 (42%) of sampled sites positive in the homes of colonized and noncolonized patients, respectively. In the nosocomial setting, it was isolated from 18 (32%) sites in the hospital ward and from 4 (17%) sites in the outpatient clinic area. The most common sites of contamination were sink drains, faucets, and other items frequently in contact with water. All environmental and clinical isolates were genotyped with enterobacterial repetitive intergenic consensus sequences as primers. A total of 33 of the 41 patients were colonized with unique strains, and four pairs of patients shared strains. Further characterization by pulsed-field gel electrophoresis after digestion with XbaI found that there was no evidence of patient-to-patient transmission; however, there was some evidence that a small number of patients may have acquired the organism from the hospital environment. Resampling of environmental sites in the hospital ward in January 1997 revealed evidence of genetic drift, complicating the accurate determination of environmental sources for clinical strains. The source of the majority of S. maltophilia strains colonizing the respiratory tracts of these patients with cystic fibrosis remained uncertain but may have represented multiple, independent acquisitions from a variety of environmental sites both within and outside the hospital. PMID:9650943

  7. Predictive Studies Suggest that the Risk for the Selection of Antibiotic Resistance by Biocides Is Likely Low in Stenotrophomonas maltophilia.

    PubMed

    Sánchez, María Blanca; Decorosi, Francesca; Viti, Carlo; Oggioni, Marco Rinaldo; Martínez, José Luis; Hernández, Alvaro

    2015-01-01

    Biocides are used without restriction for several purposes. As a consequence, large amounts of biocides are released without any control in the environment, a situation that can challenge the microbial population dynamics, including selection of antibiotic resistant bacteria. Previous work has shown that triclosan selects Stenotrophomonas maltophilia antibiotic resistant mutants overexpressing the efflux pump SmeDEF and induces expression of this pump triggering transient low-level resistance. In the present work we analyze if two other common biocides, benzalkonium chloride and hexachlorophene, trigger antibiotic resistance in S. maltophilia. Bioinformatic and biochemical methods showed that benzalkonium chloride and hexachlorophene bind the repressor of smeDEF, SmeT. Only benzalkonium chloride triggers expression of smeD and its effect in transient antibiotic resistance is minor. None of the hexachlorophene-selected mutants was antibiotic resistant. Two benzalkonium chloride resistant mutants presented reduced susceptibility to antibiotics and were impaired in growth. Metabolic profiling showed they were more proficient than their parental strain in the use of some dipeptides. We can then conclude that although bioinformatic predictions and biochemical studies suggest that both hexachlorophene and benzalkonium chloride should induce smeDEF expression leading to transient S. maltophilia resistance to antibiotics, phenotypic assays showed this not to be true. The facts that hexachlorophene resistant mutants are not antibiotic resistant and that the benzalkonium chloride resistant mutants presenting altered susceptibility to antibiotics were impaired in growth suggests that the risk for the selection (and fixation) of S. maltophilia antibiotic resistant mutants by these biocides is likely low, at least in the absence of constant selection pressure. PMID:26201074

  8. A function of SmeDEF, the major quinolone resistance determinant of Stenotrophomonas maltophilia, is the colonization of plant roots.

    PubMed

    García-León, Guillermo; Hernández, Alvaro; Hernando-Amado, Sara; Alavi, Peyman; Berg, Gabriele; Martínez, José Luis

    2014-08-01

    Quinolones are synthetic antibiotics, and the main cause of resistance to these antimicrobials is mutation of the genes encoding their targets. However, in contrast to the case for other organisms, such mutations have not been found in quinolone-resistant Stenotrophomonas maltophilia isolates, in which overproduction of the SmeDEF efflux pump is a major cause of quinolone resistance. SmeDEF is chromosomally encoded and highly conserved in all studied S. maltophilia strains; it is an ancient element that evolved over millions of years in this species. It thus seems unlikely that its main function would be resistance to quinolones, a family of synthetic antibiotics not present in natural environments until the last few decades. Expression of SmeDEF is tightly controlled by the transcriptional repressor SmeT. Our work shows that plant-produced flavonoids can bind to SmeT, releasing it from smeDEF and smeT operators. Antibiotics extruded by SmeDEF do not impede the binding of SmeT to DNA. The fact that plant-produced flavonoids specifically induce smeDEF expression indicates that they are bona fide effectors regulating expression of this resistance determinant. Expression of efflux pumps is usually downregulated unless their activity is needed. Since smeDEF expression is triggered by plant-produced flavonoids, we reasoned that this efflux pump may have a role in the colonization of plants by S. maltophilia. Our results showed that, indeed, deletion of smeE impairs S. maltophilia colonization of plant roots. Altogether, our results indicate that quinolone resistance is a recent function of SmeDEF and that colonization of plant roots is likely one original function of this efflux pump. PMID:24837376

  9. Predictive Studies Suggest that the Risk for the Selection of Antibiotic Resistance by Biocides Is Likely Low in Stenotrophomonas maltophilia

    PubMed Central

    Sánchez, María Blanca; Decorosi, Francesca; Viti, Carlo; Oggioni, Marco Rinaldo; Martínez, José Luis; Hernández, Alvaro

    2015-01-01

    Biocides are used without restriction for several purposes. As a consequence, large amounts of biocides are released without any control in the environment, a situation that can challenge the microbial population dynamics, including selection of antibiotic resistant bacteria. Previous work has shown that triclosan selects Stenotrophomonas maltophilia antibiotic resistant mutants overexpressing the efflux pump SmeDEF and induces expression of this pump triggering transient low-level resistance. In the present work we analyze if two other common biocides, benzalkonium chloride and hexachlorophene, trigger antibiotic resistance in S. maltophilia. Bioinformatic and biochemical methods showed that benzalkonium chloride and hexachlorophene bind the repressor of smeDEF, SmeT. Only benzalkonium chloride triggers expression of smeD and its effect in transient antibiotic resistance is minor. None of the hexachlorophene-selected mutants was antibiotic resistant. Two benzalkonium chloride resistant mutants presented reduced susceptibility to antibiotics and were impaired in growth. Metabolic profiling showed they were more proficient than their parental strain in the use of some dipeptides. We can then conclude that although bioinformatic predictions and biochemical studies suggest that both hexachlorophene and benzalkonium chloride should induce smeDEF expression leading to transient S. maltophilia resistance to antibiotics, phenotypic assays showed this not to be true. The facts that hexachlorophene resistant mutants are not antibiotic resistant and that the benzalkonium chloride resistant mutants presenting altered susceptibility to antibiotics were impaired in growth suggests that the risk for the selection (and fixation) of S. maltophilia antibiotic resistant mutants by these biocides is likely low, at least in the absence of constant selection pressure. PMID:26201074

  10. A Function of SmeDEF, the Major Quinolone Resistance Determinant of Stenotrophomonas maltophilia, Is the Colonization of Plant Roots

    PubMed Central

    García-León, Guillermo; Hernández, Alvaro; Hernando-Amado, Sara; Alavi, Peyman; Berg, Gabriele

    2014-01-01

    Quinolones are synthetic antibiotics, and the main cause of resistance to these antimicrobials is mutation of the genes encoding their targets. However, in contrast to the case for other organisms, such mutations have not been found in quinolone-resistant Stenotrophomonas maltophilia isolates, in which overproduction of the SmeDEF efflux pump is a major cause of quinolone resistance. SmeDEF is chromosomally encoded and highly conserved in all studied S. maltophilia strains; it is an ancient element that evolved over millions of years in this species. It thus seems unlikely that its main function would be resistance to quinolones, a family of synthetic antibiotics not present in natural environments until the last few decades. Expression of SmeDEF is tightly controlled by the transcriptional repressor SmeT. Our work shows that plant-produced flavonoids can bind to SmeT, releasing it from smeDEF and smeT operators. Antibiotics extruded by SmeDEF do not impede the binding of SmeT to DNA. The fact that plant-produced flavonoids specifically induce smeDEF expression indicates that they are bona fide effectors regulating expression of this resistance determinant. Expression of efflux pumps is usually downregulated unless their activity is needed. Since smeDEF expression is triggered by plant-produced flavonoids, we reasoned that this efflux pump may have a role in the colonization of plants by S. maltophilia. Our results showed that, indeed, deletion of smeE impairs S. maltophilia colonization of plant roots. Altogether, our results indicate that quinolone resistance is a recent function of SmeDEF and that colonization of plant roots is likely one original function of this efflux pump. PMID:24837376

  11. Distribution of Class 1 Integrons, sul1 and sul2 Genes Among Clinical Isolates of Stenotrophomonas maltophilia from a Tertiary Care Hospital in North India.

    PubMed

    Kaur, Parvinder; Gautam, Vikas; Tewari, Rupinder

    2015-08-01

    Stenotrophomonas maltophilia is an emerging nosocomial pathogen responsible for serious human infections. This study was carried out to determine antibiotic susceptibility, resistance mechanisms (integrons, sul1 and sul2), and genetic relatedness (Enterobacterial Repetitive Intergenic Consensus [ERIC]-PCR) among 106 clinical isolates of S. maltophilia from India. Twenty-four (22.6%) of S. maltophilia isolates exhibited resistance to mainstay antibiotic trimethoprim-sulfamethoxazole (TMP-SMX). Except for 2 isolates which contained both TMP-SMX resistance determinants sul1 and sul2 genes, all other 22 TMP-SMX-resistant isolates carried either sul1 (10 isolates) or sul2 (12 isolates) genes. Class 1 integrons were present in 8.5% (9 out of 106) of S. maltophilia isolates, and only 5 out of these isolates were TMP-SMX resistant and positive for sul1 gene. The same isolates also carried resistance cassettes containing qac/smr gene. Minocycline and levofloxacin exhibited the maximum in vitro activity against S. maltophilia. ERIC-PCR revealed high diversity among S. maltophilia isolates. The present study demonstrated high (22.4%) TMP-SMX resistance in clinical isolates of S. maltophilia from India. TMP-SMX-resistant isolates carried relatively higher percentage of sul2 gene than sul1 gene as against the reported literature. Majority (58.3%) of sul1 gene positive were not associated with class 1 integrase gene. PMID:25781206

  12. Emergence of fluoroquinolone-resistant Stenotrophomonas maltophilia in blood isolates causing bacteremia: molecular epidemiology and microbiologic characteristics.

    PubMed

    Cha, Min Kyeong; Kang, Cheol-In; Kim, So Hyun; Cho, Sun Young; Ha, Young Eun; Chung, Doo Ryeon; Peck, Kyong Ran; Song, Jae-Hoon

    2016-06-01

    Among 127 Stenotrophomonas maltophilia isolates causing bacteremia, 41 (32.3%) were nonsusceptible to levofloxacin, in which four sequence types and 24 diverse allelic profiles were detected. The most prevalent ST was ST77 (n = 8, 19.5%), followed by ST28 (n = 3, 7.3%). Amino acid substitutions were found in the gyrB and parC genes of 10 and 1 isolates, respectively. No amino acid substitutions were identified in gyrA. Twenty-three (56.1%) isolates showed amino acid substitutions in the parE gene. These results suggest that quinolone resistance-determining regions of parE may not be the primary targets, but an important determining factor of high levels of fluoroquinolone resistance. PMID:27117514

  13. [Methods for extraction of exopolymeric complex in plankton and biofilm growth mode of Stenotrophomonas maltophilia 22M].

    PubMed

    Boretskaia, M A; Suslova, O S

    2013-01-01

    The optimal methods for the extraction of exopolymeric complex (EPS) of Stenotrophomonas maltophilia 22M was determined. That EPS was synthesized in plankton and biofilm growth mode on the mild steel surface. It is desirable to use different physical and chemical methods for studying the EPS composition (carbohydrates and proteins) depending on the bacteria growth mode. In this way the interaction with ion exchange resin was the most effective for plankton growth mode to determine the maximum amount of carbohydrates (9.5 microg/ml), and the impact of heating to determine protein (3.9 microg/ml). For EPS biofilm in order to obtain maximum amount of carbohydrate it is desirable to use heating (30 microg/ml) and centrifugation (35 microg/ml). It is recommended to determine protein in the biofilm EPS after treatment with heating (3.75 microg/ml) and centrifugation (3.75 microg/ml). PMID:23720963

  14. Degradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by Stenotrophomonas maltophilia PB1.

    PubMed Central

    Binks, P R; Nicklin, S; Bruce, N C

    1995-01-01

    A mixed microbial culture capable of metabolizing the explosive RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) was obtained from soil enrichments under aerobic and nitrogen-limiting conditions. A bacterium, Stenotrophomonas maltophilia PB1, isolated from the culture used RDX as a sole source of nitrogen for growth. Three moles of nitrogen was used per mole of RDX, yielding a metabolite identified by mass spectroscopy and 1H nuclear magnetic resonance analysis as methylene-N-(hydroxymethyl)-hydroxylamine-N'-(hydroxymethyl)nitroamin e. The bacterium also used s-triazine as a sole source of nitrogen but not the structurally similar compounds octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine, cyanuric acid, and melamine. An inducible RDX-degrading activity was present in crude cell extracts. PMID:7747953

  15. Metabolic biotransformation of copper-benzo[a]pyrene combined pollutant on the cellular interface of Stenotrophomonas maltophilia.

    PubMed

    Chen, Shuona; Yin, Hua; Tang, Shaoyu; Peng, Hui; Liu, Zehua; Dang, Zhi

    2016-03-01

    Previous studies have confirmed that Stenotrophomonas maltophilia can bind an appreciable amount of Cu(II) and degrade BaP. However, the removal mechanisms of Cu(II) coexisted with BaP by S. maltophilia are still unclear. In this study, the micro-interaction of contaminants on the cellular surface was investigated. The results indicated that carboxyl groups played an important role in the binding of copper to the thallus and that the cell walls were the main adsorption sites. Nevertheless, these reactive groups had no obvious effect on the uptake of BaP. Instead, the disruption and modification of cell walls accelerated transportation of BaP across the membrane into cells. The observation of SEM-EDS confirmed that Cu(II) would be adsorbed and precipitated onto the cell surface but would also be removed by extracellular precipitation when BaP coexisted. And the XPS analysis reflected that part of Cu(II) bound onto biosorbents changed into Cu(I) and Cu. PMID:26771922

  16. Purification and characterization of novel organic solvent tolerant 98kDa alkaline protease from isolated Stenotrophomonas maltophilia strain SK.

    PubMed

    Waghmare, Shailesh R; Gurav, Aparna A; Mali, Sonal A; Nadaf, Naiem H; Jadhav, Deepak B; Sonawane, Kailas D

    2015-03-01

    Ability of microorganisms to grow at alkaline pH makes them an attractive target for several industrial applications. Thus, search for new extremozyme producing microorganisms must be a continuous exercise. Hence, we isolated a potent alkaline protease producing bacteria from slaughter house soil. The morphological, biochemical and 16S rDNA gene sequencing studies revealed that the isolated bacteria is Stenotrophomonas maltophilia strain SK. Alkaline protease from S. maltophilia strain SK was purified by using ammonium sulphate precipitation and DEAE-cellulose ion exchange column chromatography. The purified enzyme was optimally active at pH 9.0 and temperature 40°C with broad substrate specificity. It was observed that the metal ions such as Ca(++), Mg(++) and Fe(+++) completely repressed the enzyme activity. The enzyme was stable in presence of various water miscible solvents like ethanol, methanol, isopropanol at 25% (v/v) concentration and less stable at 37.5% (v/v) concentration. These robust properties of enzyme might be applicable for various applications in detergent and pharmaceutical industries. PMID:25462807

  17. Antibacterial Activity of Stenotrophomonas maltophilia Endolysin P28 against both Gram-positive and Gram-negative Bacteria

    PubMed Central

    Dong, Hongling; Zhu, Chaoyang; Chen, Jingyi; Ye, Xing; Huang, Yu-Ping

    2015-01-01

    Maltocin P28 is a phage-tail like bacteriocin produced by Stenotrophomonas maltophilia P28. The ORF8 of maltocin P28 gene cluster is predicted to encode an endolysin and we name it endolysin P28. Sequence analysis revealed that it contains the lysozyme_like superfamily conserved domain. Endolysin P28 has the four consensus motifs as that of Escherichia coli phage lambda gpR. In this study, endolysin P28 was expressed in E. coli BL21 (DE3) and purified with a C-terminal oligo-histidine tag. The antibacterial activity of endolysin P28 increased as the temperature rose from 25 to 45°C. Thermostability assays showed that endolysin P28 was stable up to 50°C, while its residual activity was reduced by 55% after treatment at 70°C for 30 min. Acidity and high salinity could enhance its antibacterial activity. Endolysin P28 exhibited a broad antibacterial activity against 14 out of 16 tested Gram-positive and Gram-negative bacteria besides S. maltophilia. Moreover, it could effectively lyse intact Gram-negative bacteria in the absence of ethylenediaminetetraacetic acid as an outer membrane permeabilizer. Therefore, the characteristics of endolysin P28 make it a potential therapeutic agent against multi-drug-resistant pathogens. PMID:26635765

  18. Comparison of Antifungal Activities and 16S Ribosomal DNA Sequences of Clinical and Environmental Isolates of Stenotrophomonas maltophilia

    PubMed Central

    Minkwitz, Arite; Berg, Gabriele

    2001-01-01

    In recent years, the gram-negative bacterium Stenotrophomonas maltophilia has become increasingly important in biotechnology and as a nosocomial pathogen, giving rise to a need for new information about its taxonomy and epidemiology. To determine intraspecies diversity and whether strains can be distinguished based on the sources of their isolation, 50 S. maltophilia isolates from clinical and environmental sources, including strains of biotechnological interest, were investigated. The isolates were characterized by in vitro antagonism against pathogenic fungi and the production of antifungal metabolites and enzymes. Phenotypically the strains showed variability that did not correlate significantly with their sources of isolation. Clinical strains displayed remarkable activity against the human pathogenic fungus Candida albicans. Antifungal activity against plant pathogens was more common and generally more severe from the environmental isolates, although not exclusive to them. All isolates, clinical and environmental, produced a range of antifungal metabolites including antibiotics, siderophores, and the enzymes proteases and chitinases. From 16S ribosomal DNA sequencing analysis, the isolates could be separated into three clusters, two of which consisted of isolates originating from the environment, especially rhizosphere isolates, and one of which consisted of clinical and aquatic strains. In contrast to the results of other recent investigations, these strains could be grouped based on their sources of isolation, with the exception of three rhizosphere isolates. Because there was evidence of nucleotide signature positions within the sequences that are suitable for distinguishing among the clusters, the clusters could be defined as different genomovars of S. maltophilia. Key sequences on the 16S ribosomal DNA could be used to develop a diagnostic method that differentiates these genomovars. PMID:11136762

  19. Genome-Wide Identification of Genes Necessary for Biofilm Formation by Nosocomial Pathogen Stenotrophomonas maltophilia Reveals that Orphan Response Regulator FsnR Is a Critical Modulator

    PubMed Central

    Kang, Xiu-Min; Wang, Fang-Fang; Zhang, Huan

    2014-01-01

    Stenotrophomonas maltophilia is a Gram-negative bacterial pathogen of increasing concern to human health. Most clinical isolates of S. maltophilia efficiently form biofilms on biotic and abiotic surfaces, making this bacterium resistant to a number of antibiotic treatments and therefore difficult to eliminate. To date, very few studies have investigated the molecular and regulatory mechanisms responsible for S. maltophilia biofilm formation. Here we constructed a random transposon insertion mutant library of S. maltophilia ATCC 13637 and screened 14,028 clones. A total of 46 nonredundant genes were identified. Mutants of these genes exhibited marked changes in biofilm formation, suggesting that multiple physiological pathways, including extracellular polysaccharide production, purine synthesis, transportation, and peptide and lipid synthesis, are involved in bacterial cell aggregation. Of these genes, 20 putatively contributed to flagellar biosynthesis, indicating a critical role for cell motility in S. maltophilia biofilm formation. Genetic and biochemical evidence demonstrated that an orphan response regulator, FsnR, activated transcription of at least two flagellum-associated operons by directly binding to their promoters. This regulatory protein plays a fundamental role in controlling flagellar assembly, cell motility, and biofilm formation. These results provide a genetic basis to systematically study biofilm formation of S. maltophilia. PMID:25480754

  20. Stenotrophomonas maltophilia responds to exogenous AHL signals through the LuxR solo SmoR (Smlt1839).

    PubMed

    Martnez, Paula; Huedo, Pol; Martinez-Servat, Snia; Planell, Raquel; Ferrer-Navarro, Mario; Daura, Xavier; Yero, Daniel; Gibert, Isidre

    2015-01-01

    Quorum Sensing (QS) mediated by Acyl Homoserine Lactone (AHL) molecules are probably the most widespread and studied among Gram-negative bacteria. Canonical AHL systems are composed by a synthase (LuxI family) and a regulator element (LuxR family), whose genes are usually adjacent in the genome. However, incomplete AHL-QS machinery lacking the synthase LuxI is frequently observed in Proteobacteria, and the regulator element is then referred as LuxR solo. It has been shown that certain LuxR solos participate in interspecific communication by detecting signals produced by different organisms. In the case of Stenotrophomonas maltophilia, a preliminary genome sequence analysis revealed numerous putative luxR genes, none of them associated to a luxI gene. From these, the hypothetical LuxR solo Smlt1839, here designated SmoR, presents a conserved AHL binding domain and a helix-turn-helix DNA binding motif. Its genomic organization-adjacent to hchA gene-indicate that SmoR belongs to the new family "LuxR regulator chaperone HchA-associated." AHL-binding assays revealed that SmoR binds to AHLs in-vitro, at least to oxo-C8-homoserine lactone, and it regulates operon transcription, likely by recognizing a conserved palindromic regulatory box in the hchA upstream region. Supplementation with concentrated supernatants from Pseudomonas aeruginosa, which contain significant amounts of AHLs, promoted swarming motility in S. maltophilia. Contrarily, no swarming stimulation was observed when the P. aeruginosa supernatant was treated with the lactonase AiiA from Bacillus subtilis, confirming that AHL contributes to enhance the swarming ability of S. maltophilia. Finally, mutation of smoR resulted in a swarming alteration and an apparent insensitivity to the exogenous AHLs provided by P. aeruginosa. In conclusion, our results demonstrate that S. maltophilia senses AHLs produced by neighboring bacteria through the LuxR solo SmoR, regulating population behaviors such as swarming motility. PMID:26029670

  1. Stenotrophomonas maltophilia responds to exogenous AHL signals through the LuxR solo SmoR (Smlt1839)

    PubMed Central

    Martínez, Paula; Huedo, Pol; Martinez-Servat, Sònia; Planell, Raquel; Ferrer-Navarro, Mario; Daura, Xavier; Yero, Daniel; Gibert, Isidre

    2015-01-01

    Quorum Sensing (QS) mediated by Acyl Homoserine Lactone (AHL) molecules are probably the most widespread and studied among Gram-negative bacteria. Canonical AHL systems are composed by a synthase (LuxI family) and a regulator element (LuxR family), whose genes are usually adjacent in the genome. However, incomplete AHL-QS machinery lacking the synthase LuxI is frequently observed in Proteobacteria, and the regulator element is then referred as LuxR solo. It has been shown that certain LuxR solos participate in interspecific communication by detecting signals produced by different organisms. In the case of Stenotrophomonas maltophilia, a preliminary genome sequence analysis revealed numerous putative luxR genes, none of them associated to a luxI gene. From these, the hypothetical LuxR solo Smlt1839, here designated SmoR, presents a conserved AHL binding domain and a helix-turn-helix DNA binding motif. Its genomic organization—adjacent to hchA gene—indicate that SmoR belongs to the new family “LuxR regulator chaperone HchA-associated.” AHL-binding assays revealed that SmoR binds to AHLs in-vitro, at least to oxo-C8-homoserine lactone, and it regulates operon transcription, likely by recognizing a conserved palindromic regulatory box in the hchA upstream region. Supplementation with concentrated supernatants from Pseudomonas aeruginosa, which contain significant amounts of AHLs, promoted swarming motility in S. maltophilia. Contrarily, no swarming stimulation was observed when the P. aeruginosa supernatant was treated with the lactonase AiiA from Bacillus subtilis, confirming that AHL contributes to enhance the swarming ability of S. maltophilia. Finally, mutation of smoR resulted in a swarming alteration and an apparent insensitivity to the exogenous AHLs provided by P. aeruginosa. In conclusion, our results demonstrate that S. maltophilia senses AHLs produced by neighboring bacteria through the LuxR solo SmoR, regulating population behaviors such as swarming motility. PMID:26029670

  2. Adaptation of Stenotrophomonas maltophilia in cystic fibrosis: molecular diversity, mutation frequency and antibiotic resistance.

    PubMed

    Vidigal, P G; Dittmer, S; Steinmann, E; Buer, J; Rath, P-M; Steinmann, J

    2014-07-01

    Due to the continuous exposure to a challenging environment and repeated antibiotic treatment courses, bacterial populations in cystic fibrosis (CF) patients experience selective pressure causing the emergence of mutator phenotypes. In this study we investigated the genotypic diversity, mutation frequency and antibiotic resistance of S. maltophilia isolates chronically colonizing CF patients. S. maltophilia was isolated from a total of 90 sputum samples, collected sequentially from 19 CF patients admitted between January 2008 and March 2012 at the University Hospital Essen, Germany. DNA fingerprinting by repetitive-sequence-based PCR revealed that 68.4% (n=13) of CF patients harbored different S. maltophilia genotypes during the 4-year study course. Out of 90 S. maltophilia isolates obtained from chronically colonized CF patients, 17.8% (n=16) were hypomutators, 27.7% (n=25), normomutators, 23.3% (n=21), weak hypermutators and 31.2% (n=28) strong hypermutators. We also found that mutation rates of the most clonally related genotypes varied over time with the tendency to become less mutable. Mutator isolates were found to have no significant increase in resistance against eight different antibiotics versus nonmutators. Sequencing of the mismatch repair genes mutL, mutS and uvrD revealed alterations that resulted in amino acid changes in their corresponding proteins. Here, we could demonstrate that several different S. maltophilia genotypes are present in CF patients and as a sign of adaption their mutation status switches over time to a less mutator phenotype without increasing resistance. These results suggest that S. maltophilia attempts to sustain its biological fitness as mechanism for long-term persistence in the CF lung. PMID:24836944

  3. Identification and characterization of a serious multidrug resistant Stenotrophomonas maltophilia strain in China.

    PubMed

    Zhao, Yan; Niu, Wenkai; Sun, Yanxia; Hao, Huaijie; Yu, Dong; Xu, Guangyang; Shang, Xueyi; Tang, Xueping; Lu, Sijing; Yue, Junjie; Li, Yan

    2015-01-01

    An S. maltophilia strain named WJ66 was isolated from a patient; WJ66 showed resistance to more antibiotics than the other S. maltophilia strains. This bacteraemia is resistant to sulphonamides, or fluoroquinolones, while the representative strain of S. maltophilia, K279a, is sensitive to both. To explore drug resistance determinants of this strain, the draft genome sequence of WJ66 was determined and compared to other S. maltophilia sequences. Genome sequencing and genome-wide evolutionary analysis revealed that WJ66 was highly homologous with the strain K279a, but strain WJ66 contained additional antibiotic resistance genes. Further analysis confirmed that strain WJ66 contained an amino acid substitution (Q83L) in fluoroquinolone target GyrA and carried a class 1 integron, with an aadA2 gene in the resistance gene cassette. Homology analysis from the pathogen-host interaction database showed that strain WJ66 lacks raxST and raxA, which is consistent with K279a. Comparative genomic analyses revealed that subtle nucleotide differences contribute to various significant phenotypes in close genetic relationship strains. PMID:25654114

  4. Identification and Characterization of a Serious Multidrug Resistant Stenotrophomonas maltophilia Strain in China

    PubMed Central

    Zhao, Yan; Niu, Wenkai; Sun, Yanxia; Hao, Huaijie; Yu, Dong; Xu, Guangyang; Shang, Xueyi; Tang, Xueping; Lu, Sijing; Li, Yan

    2015-01-01

    An S. maltophilia strain named WJ66 was isolated from a patient; WJ66 showed resistance to more antibiotics than the other S. maltophilia strains. This bacteraemia is resistant to sulphonamides, or fluoroquinolones, while the representative strain of S. maltophilia, K279a, is sensitive to both. To explore drug resistance determinants of this strain, the draft genome sequence of WJ66 was determined and compared to other S. maltophilia sequences. Genome sequencing and genome-wide evolutionary analysis revealed that WJ66 was highly homologous with the strain K279a, but strain WJ66 contained additional antibiotic resistance genes. Further analysis confirmed that strain WJ66 contained an amino acid substitution (Q83L) in fluoroquinolone target GyrA and carried a class 1 integron, with an aadA2 gene in the resistance gene cassette. Homology analysis from the pathogen-host interaction database showed that strain WJ66 lacks raxST and raxA, which is consistent with K279a. Comparative genomic analyses revealed that subtle nucleotide differences contribute to various significant phenotypes in close genetic relationship strains. PMID:25654114

  5. Characterization of salt-tolerant glutaminase from Stenotrophomonas maltophilia NYW-81 and its application in Japanese soy sauce fermentation.

    PubMed

    Wakayama, Mamoru; Yamagata, Tomohiro; Kamemura, Aki; Bootim, Nitaya; Yano, Shigekazu; Tachiki, Takashi; Yoshimune, Kazuaki; Moriguchi, Mitsuaki

    2005-09-01

    Glutaminase from Stenotrophomonas maltophilia NYW-81 was purified to homogeneity with a final specific activity of 325 U/mg. The molecular mass of the native enzyme was estimated to be 41 kDa by gel filtration. A subunit molecular mass of 36 kDa was measured with SDS-PAGE, thus indicating that the native enzyme is a monomer. The N-terminal amino acid sequence of the enzyme was determined to be KEAETQQKLANVVILATGGTIA. Besides L: -glutamine, which was hydrolyzed with the highest specific activity (100%), L: -asparagine (74%), D: -glutamine (75%), and D: -asparagine (67%) were also hydrolyzed. The pH and temperature optima were 9.0 and approximately 60 degrees C, respectively. The enzyme was most stable at pH 8.0 and was highly stable (relative activities from 60 to 80%) over a wide pH range (5.0-10.0). About 70 and 50% of enzyme activity was retained even after treatment at 60 and 70 degrees C, respectively, for 10 min. The enzyme showed high activity (86% of the original activity) in the presence of 16% NaCl. These results indicate that this enzyme has a higher salt tolerance and thermal stability than bacterial glutaminases that have been reported so far. In a model reaction of Japanese soy sauce fermentation, glutaminase from S. maltophilia exhibited high ability in the production of glutamic acid compared with glutaminases from Aspergillus oryzae, Escherichia coli, Pseudomonas citronellolis, and Micrococcus luteus, indicating that this enzyme is suitable for application in Japanese soy sauce fermentation. PMID:16012776

  6. Intra- and Interspecies Effects of Outer Membrane Vesicles from Stenotrophomonas maltophilia on β-Lactam Resistance.

    PubMed

    Devos, Simon; Stremersch, Stephan; Raemdonck, Koen; Braeckmans, Kevin; Devreese, Bart

    2016-04-01

    The treatment ofStenotrophomonas maltophiliainfection with β-lactam antibiotics leads to increased release of outer membrane vesicles (OMVs), which are packed with two chromosomally encoded β-lactamases. Here, we show that these β-lactamase-packed OMVs are capable of establishing extracellular β-lactam degradation. We also show that they dramatically increase the apparent MICs of imipenem and ticarcillin for the cohabituating speciesPseudomonas aeruginosaandBurkholderia cenocepacia. PMID:26787686

  7. Cis-9-octadecenoic acid from the rhizospheric bacterium Stenotrophomonas maltophilia BJ01 shows quorum quenching and anti-biofilm activities.

    PubMed

    Singh, Vijay Kumar; Kavita, Kumari; Prabhakaran, Rathish; Jha, Bhavanath

    2013-01-01

    Quorum quenching (QQ) is an effective approach for the prevention of bacterial infections involving biofilms. This study reports the QQ and anti-biofilm activities of a rhizospheric bacterium identified as Stenotrophomonas maltophilia BJ01. The QQ activity was demonstrated using Chromobacterium violaceum CV026 as a biosensor. A maximum of 95% reduction in violacein production, a quorum sensing-regulated behavior, was observed. Gas chromatography-mass spectroscopy of the extract showed that the active compound was cis-9-octadecenoic acid, which was confirmed by electronspray ionization-mass spectroscopy data. The extract also inhibited biofilm formation of Pseudomonas aeruginosa ATCC 9027 without affecting its growth. Scanning electron and atomic force microscopy showed architectural disruption of the biofilm when treated with the extract. This is the first report of the QQ and anti-biofilm activities of cis-9-octadecenoic acid isolated from any bacterium. It may have the potential to combat detrimental infections with P. aeruginosa. Further validation is required for any possible medical application. PMID:23844805

  8. Site-selective binding of Zn(II) to metallo-beta-lactamase L1 from Stenotrophomonas maltophilia.

    PubMed

    Costello, Alison; Periyannan, Gopalraj; Yang, Ke-Wu; Crowder, Michael W; Tierney, David L

    2006-04-01

    Extended X-ray absorption fine structure studies of the metallo-beta-lactamase L1 from Stenotrophomonas maltophilia containing 1 and 2 equiv of Zn(II) and containing 2 equiv of Zn(II) plus hydrolyzed nitrocefin are presented. The data indicate that the first, catalytically dominant metal ion is bound by L1 at the consensus Zn1 site. The data further suggest that binding of the first metal helps preorganize the ligands for binding of the second metal ion. The di-Zn enzyme displays a well-defined metal-metal interaction at 3.42 A. Reaction with the beta-lactam antibiotic nitrocefin results in a product-bound species, in which the ring-opened lactam rotates in the active site to present the S1 sulfur atom of nitrocefin to one of the metal ions for coordination. The product bridges the two metal ions, with a concomitant lengthening of the Zn-Zn interaction to 3.62 A. PMID:16489411

  9. A Patient Presenting with Cholangitis due to Stenotrophomonas Maltophilia and Pseudomonas Aeruginosa Successfully Treated with Intrabiliary Colistine.

    PubMed

    Pérez, Pablo N; Ramírez, María A; Fernández, José A; de Guevara, Laura Ladrón

    2014-05-13

    Anatomical barriers for antibiotic penetration can pose a particular challenge in the clinical setting. Stenotrophomonas maltophilia (SM) and Pseudomonas aeruginosa (PA) are two pathogens capable of developing multiple drug-resistance (MDR) mechanisms. We report the case of a 56-year-old female patient with a permanent percutaneous transhepatic biliary drainage (PTBD), who was admitted to our hospital with a cholangitis due to a MDR Escherichia coli strain. Upon admission, culture-guided antimicrobial therapy was conducted and the biliary catheter was replaced, with poor clinical response. Subsequently, SM and PA were detected. Treatment with fosfomycin and colistine was initiated, again without adequate response. Systemic colistine and tigecycline along with an intrabiliary infusion of colistine for 5 days was then used, followed by parenteral fosfomycin and tigecycline for 7 days. The patient was then successfully discharged. This is the first case report we are aware of on the use of intrabiliary colistine. It describes a new approach to treating cholangitis by MDR bacteria in patients with a PTBD. PMID:25002957

  10. Site Selective Binding of Zn(ll) ot Metallo-b-Lactamase L1 from Stenotrophomonas Maltophilia

    SciTech Connect

    Costello,A.; Periyannan, G.; Yang, K.; Crowder, M.; Tierney, D.

    2006-01-01

    Extended X-ray absorption fine structure studies of the metallo-{beta}-lactamase L1 from Stenotrophomonas maltophilia containing 1 and 2 equiv of Zn(II) and containing 2 equiv of Zn(II) plus hydrolyzed nitrocefin are presented. The data indicate that the first, catalytically dominant metal ion is bound by L1 at the consensus Zn1 site. The data further suggest that binding of the first metal helps preorganize the ligands for binding of the second metal ion. The di-Zn enzyme displays a well-defined metal-metal interaction at 3.42 Angstroms. Reaction with the {beta}-lactam antibiotic nitrocefin results in a product-bound species, in which the ring-opened lactam rotates in the active site to present the S1 sulfur atom of nitrocefin to one of the metal ions for coordination. The product bridges the two metal ions, with a concomitant lengthening of the Zn-Zn interaction to 3.62 Angstroms.

  11. Degradation of abamectin by newly isolated Stenotrophomonas maltophilia ZJB-14120 and characterization of its abamectin-tolerance mechanism.

    PubMed

    Wang, Yuan-Shan; Zheng, Xing-Chang; Hu, Qi-Wei; Zheng, Yu-Guo

    2015-06-01

    An abamectin (ABM)-degrading bacterium, Stenotrophomonas maltophilia ZJB-14120, was isolated and identified. This strain is capable of degrading 84.82% of ABM at an initial concentration of 200 mg/L over a 48 h incubation period. This strain showed efficient biodegradation ability (7.81 mg/L/h) to ABM and high tolerance (1000 mg/L) to all macrolides tested. In addition to ABM, emamectin, erythromycin and spiramycin can also be degraded by this strain. Modifications involving either reduction of the double bond between C22-C23 or replacement of the C25-group of ABM with a cyclohexyl group can completely inhibit biodegradation of ABM. The ABM-degrading capability of strain ZJB-14120 is likely to be intrinsic to its metabolism and could be inhibited by incubating with erythromycin, azithromycin, spiramycin or rifampicin. A new and successive degradation pathway was proposed based on metabolite analysis. Although there is evidence for metabolite inhibition, this strain has high ABM degradation activity and reusability. Further investigation showed that activated macrolide efflux pump(s) and an undetermined mechanism for regulating the intracellular ABM concentration are responsible for normal uptake of essential metabolites while pumping out excess harmful compounds. Strain ZJB-14120 may provide efficient treatment of water and soil contaminated by toxic levels of abamectin and emamectin. PMID:25957243

  12. Prevalence of Smqnr and plasmid-mediated quinolone resistance determinants in clinical isolates of Stenotrophomonas maltophilia from Japan: novel variants of Smqnr.

    PubMed

    Kanamori, H; Yano, H; Tanouchi, A; Kakuta, R; Endo, S; Ichimura, S; Ogawa, M; Shimojima, M; Inomata, S; Ozawa, D; Aoyagi, T; Weber, D J; Kaku, M

    2015-09-01

    Stenotrophomonas maltophilia is an important pathogen in healthcare-associated infections. S. maltophilia may contain Smqnr, a quinolone resistance gene encoding the pentapeptide repeat protein, which confers low-level quinolone resistance upon expression in a heterologous host. We investigated the prevalence of Smqnr and plasmid-mediated quinolone resistance (PMQR) determinants in S. maltophilia isolates from Japan. A total of 181 consecutive and nonduplicate clinical isolates of S. maltophilia were collected from four areas of Japan. The antimicrobial susceptibility profiles for these strains were determined. PCR was conducted for Smqnr and PMQR genes, including qnrA, qnrB, qnrC, qnrS, aac(6')-Ib and qepA. PCR products for Smqnr and aac(6')-Ib were sequenced. For the S. maltophilia isolates containing Smqnr, pulsed-field gel electrophoresis (PFGE) was performed using XbaI. Resistance rates to ceftazidime, levofloxacin, trimethoprim-sulfamethoxazole, chloramphenicol and minocycline were 67.4%, 6.1%, 17.7%, 8.8% and 0%, respectively. The minimum inhibitory concentration required to inhibit the growth of 50% and 90% of organisms were 0.5 and 2 mg/L for moxifloxacin but 1 and 4 mg/L for levofloxacin, respectively. Smqnr was detected in 104 of the 181 S. maltophilia isolates (57.5%), and the most frequent was Smqnr6, followed by Smqnr8 and Smqnr11. Eleven novel variants from Smqnr48 to Smqnr58 were detected. The 24 Smqnr-containing S. maltophilia isolates were typed by PFGE and divided into 21 unique types. Nine S. maltophilia isolates (5.0%) carried aac(6')-Ib-cr. No qnr or qepA genes were detected. This study describes a high prevalence of Smqnr and novel variants of Smqnr among S. maltophilia from Japan. Continuous antimicrobial surveillance and further molecular epidemiological studies on quinolone resistance in S. maltophilia are needed. PMID:26110061

  13. Identification of a novel 6'-N-aminoglycoside acetyltransferase, AAC(6')-Iak, from a multidrug-resistant clinical isolate of Stenotrophomonas maltophilia.

    PubMed

    Tada, Tatsuya; Miyoshi-Akiyama, Tohru; Dahal, Rajan K; Mishra, Shyam K; Shimada, Kayo; Ohara, Hiroshi; Kirikae, Teruo; Pokhrel, Bharat M

    2014-10-01

    Stenotrophomonas maltophilia IOMTU250 has a novel 6'-N-aminoglycoside acetyltransferase-encoding gene, aac(6')-Iak. The encoded protein, AAC(6')-Iak, consists of 153 amino acids and has 86.3% identity to AAC(6')-Iz. Escherichia coli transformed with a plasmid containing aac(6')-Iak exhibited decreased susceptibility to arbekacin, dibekacin, neomycin, netilmicin, sisomicin, and tobramycin. Thin-layer chromatography showed that AAC(6')-Iak acetylated amikacin, arbekacin, dibekacin, isepamicin, kanamycin, neomycin, netilmicin, sisomicin, and tobramycin but not apramycin, gentamicin, or lividomycin. PMID:25092711

  14. Risk Factors and Outcomes of Stenotrophomonas maltophilia Bacteraemia: A Comparison with Bacteraemia Caused by Pseudomonas aeruginosa and Acinetobacter Species

    PubMed Central

    Hotta, Go; Matsumura, Yasufumi; Kato, Karin; Nakano, Satoshi; Yunoki, Tomoyuki; Yamamoto, Masaki; Nagao, Miki; Ito, Yutaka; Takakura, Shunji; Ichiyama, Satoshi

    2014-01-01

    Stenotrophomonas maltophilia (SM) is an important nosocomial pathogen that exhibits intrinsic resistance to various antimicrobial agents. However, the risk factors for SM bacteraemia have not been sufficiently evaluated. From January 2005 to September 2012, we retrospectively compared the clinical backgrounds and outcomes of SM bacteraemic patients (SM group) with those of bacteraemic patients due to Pseudomonas aeruginosa (PA group) or Acinetobacter species (AC group). DNA genotyping of the SM isolates using the Diversilab system was performed to investigate the genetic relationships among the isolates. The SM, PA, and AC groups included 54, 167, and 69 patients, respectively. Nine of 17 patients in the SM group receiving trimethoprim-sulfamethoxazole prophylaxis developed SM bacteraemia. Independent risk factors for SM bacteraemia were the use of carbapenems and antipseudomonal cephalosporins and SM isolation within 30 days prior to the onset of bacteraemia. Earlier SM isolation was observed in 32 of 48 patients (66.7%) with SM bacteraemia who underwent clinical microbiological examinations. Of these 32 patients, 15 patients (46.9%) had the same focus of bacteraemia as was found in the previous isolation site. The 30-day all-cause mortality rate among the SM group (33.3%) was higher than that of the PA group (21.5%, p = 0.080) and the AC group (17.3%, p = 0.041). The independent factor that was associated with 30-day mortality was the SOFA score. DNA genotyping of SM isolates and epidemiological data suggested that no outbreak had occurred. SM bacteraemia was associated with high mortality and should be considered in patients with recent use of broad-spectrum antibiotics or in patients with recent isolation of the organism. PMID:25375244

  15. Plasmid location and molecular heterogeneity of the L1 and L2 beta-lactamase genes of Stenotrophomonas maltophilia.

    PubMed

    Avison, M B; Higgins, C S; von Heldreich, C J; Bennett, P M; Walsh, T R

    2001-02-01

    An approximately 200-kb plasmid has been purified from clinical isolates of Stenotrophomonas maltophilia. This plasmid was found in all of the 10 isolates examined and contains both the L1 and the L2 beta-lactamase genes. The location of L1 and L2 on a plasmid makes it more likely that they could spread to other gram-negative bacteria, potentially causing clinical problems. Sequence analysis of the 10 L1 genes revealed three novel genes, L1c, L1d, and L1e, with 8, 12, and 20% divergence from the published strain IID 1275 L1 (L1a), respectively. The most unusual L1 enzyme (L1e) displayed markedly different kinetic properties, with respect to hydrolysis of nitrocefin and imipenem, compared to those of L1a (250- and 100-fold lower k(cat)/K(m) ratios respectively). L1c and L1d, in contrast, displayed levels of hydrolysis very similar to that of L1a. Several nonconservative amino acid differences with respect to L1a, L1b, L1c, and L1d were observed in the substrate binding-catalytic regions of L1e, and this could explain the kinetic differences. Three novel L2 genes (L2b, L2c, and L2d) were sequenced from the same isolates, and their sequences diverge from the published sequence of strain IID 1275 L2 (L2a) by 4, 9, and 25%, respectively. Differences in L1 and L2 gene sequences were not accompanied by similar divergences in 16S rRNA gene sequences, for which differences of <1% were found. It is therefore apparent that the L1 and L2 genes have evolved relatively quickly, perhaps because of their presence on a plasmid. PMID:11158734

  16. Antibacterial and Cytotoxic Efficacy of Extracellular Silver Nanoparticles Biofabricated from Chromium Reducing Novel OS4 Strain of Stenotrophomonas maltophilia

    PubMed Central

    Oves, Mohammad; Khan, Mohammad Saghir; Zaidi, Almas; Ahmed, Arham S.; Ahmed, Faheem; Ahmad, Ejaz; Sherwani, Asif; Owais, Mohammad; Azam, Ameer

    2013-01-01

    Biofabricated metal nanoparticles are generally biocompatible, inexpensive, and ecofriendly, therefore, are used preferably in industries, medical and material science research. Considering the importance of biofabricated materials, we isolated, characterized and identified a novel bacterial strain OS4 of Stenotrophomonas maltophilia (GenBank: JN247637.1). At neutral pH, this Gram negative bacterial strain significantly reduced hexavalent chromium, an important heavy metal contaminant found in the tannery effluents and minings. Subsequently, even at room temperature the supernatant of log phase grown culture of strain OS4 also reduced silver nitrate (AgNO3) to generate nanoparticles (AgNPs). These AgNPs were further characterized by UV–visible, Nanophox particle size analyzer, XRD, SEM and FTIR. As evident from the FTIR data, plausibly the protein components of supernatant caused the reduction of AgNO3. The cuboid and homogenous AgNPs showed a characteristic UV-visible peak at 428 nm with average size of ∼93 nm. The XRD spectra exhibited the characteristic Bragg peaks of 111, 200, 220 and 311 facets of the face centred cubic symmetry of nanoparticles suggesting that these nanoparticles were crystalline in nature. From the nanoparticle release kinetics data, the rapid release of AgNPs was correlated with the particle size and increasing surface area of the nanoparticles. A highly significant antimicrobial activity against medically important bacteria by the biofabricated AgNPs was also revealed as decline in growth of Staphylococcus aureus (91%), Escherichia coli (69%) and Serratia marcescens (66%) substantially. Additionally, different cytotoxic assays showed no toxicity of AgNPs to liver function, RBCs, splenocytes and HeLa cells, hence these particles were safe to use. Therefore, this novel bacterial strain OS4 is likely to provide broad spectrum benefits for curing chromium polluted sites, for biofabrication of AgNPs and ultimately in the nanoparticle based drug formulation for the treatment of infectious diseases. PMID:23555625

  17. The SmeYZ efflux pump of Stenotrophomonas maltophilia contributes to drug resistance, virulence-related characteristics, and virulence in mice.

    PubMed

    Lin, Yi-Tsung; Huang, Yi-Wei; Chen, Shiang-Jiuun; Chang, Chia-Wei; Yang, Tsuey-Ching

    2015-07-01

    The resistance-nodulation-division (RND)-type efflux pump is one of the causes of the multidrug resistance of Stenotrophomonas maltophilia. The roles of the RND-type efflux pump in physiological functions and virulence, in addition to antibiotic extrusion, have attracted much attention. In this study, the contributions of the constitutively expressed SmeYZ efflux pump to drug resistance, virulence-related characteristics, and virulence were evaluated. S. maltophilia KJ is a clinical isolate of multidrug resistance. The smeYZ isogenic deletion mutant, KJΔYZ, was constructed by a gene replacement strategy. The antimicrobial susceptibility, virulence-related physiological characteristics, susceptibility to human serum and neutrophils, and in vivo virulence between KJ and KJΔYZ were comparatively assessed. The SmeYZ efflux pump contributed resistance to aminoglycosides and trimethoprim-sulfamethoxazole. Inactivation of smeYZ resulted in attenuation of oxidative stress susceptibility, swimming, flagella formation, biofilm formation, and secreted protease activity. Furthermore, loss of SmeYZ increased susceptibility to human serum and neutrophils and decreased in vivo virulence in a murine model. These findings suggest the possibility of attenuation of the resistance and virulence of S. maltophilia with inhibitors of the SmeYZ efflux pump. PMID:25918140

  18. In Vitro Antibacterial and Antibiofilm Activities of Chlorogenic Acid against Clinical Isolates of Stenotrophomonas maltophilia including the Trimethoprim/Sulfamethoxazole Resistant Strain

    PubMed Central

    Karunanidhi, Arunkumar; Thomas, Renjan; van Belkum, Alex; Neela, Vasanthakumari

    2013-01-01

    The in vitro antibacterial and antibiofilm activity of chlorogenic acid against clinical isolates of Stenotrophomonas maltophilia was investigated through disk diffusion, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), time-kill and biofilm assays. A total of 9 clinical S. maltophilia isolates including one isolate resistant to trimethoprim/sulfamethoxazole (TMP/SMX) were tested. The inhibition zone sizes for the isolates ranged from 17 to 29 mm, while the MIC and MBC values ranged from 8 to 16 μg mL−1 and 16 to 32 μg mL−1. Chlorogenic acid appeared to be strongly bactericidal at 4x MIC, with a 2-log reduction in viable bacteria at 10 h. In vitro antibiofilm testing showed a 4-fold reduction in biofilm viability at 4x MIC compared to 1x MIC values (0.085 < 0.397 A 490 nm) of chlorogenic acid. The data from this study support the notion that the chlorogenic acid has promising in vitro antibacterial and antibiofilm activities against S. maltophilia. PMID:23509719

  19. The SmeYZ Efflux Pump of Stenotrophomonas maltophilia Contributes to Drug Resistance, Virulence-Related Characteristics, and Virulence in Mice

    PubMed Central

    Lin, Yi-Tsung; Huang, Yi-Wei; Chen, Shiang-Jiuun; Chang, Chia-Wei

    2015-01-01

    The resistance-nodulation-division (RND)-type efflux pump is one of the causes of the multidrug resistance of Stenotrophomonas maltophilia. The roles of the RND-type efflux pump in physiological functions and virulence, in addition to antibiotic extrusion, have attracted much attention. In this study, the contributions of the constitutively expressed SmeYZ efflux pump to drug resistance, virulence-related characteristics, and virulence were evaluated. S. maltophilia KJ is a clinical isolate of multidrug resistance. The smeYZ isogenic deletion mutant, KJΔYZ, was constructed by a gene replacement strategy. The antimicrobial susceptibility, virulence-related physiological characteristics, susceptibility to human serum and neutrophils, and in vivo virulence between KJ and KJΔYZ were comparatively assessed. The SmeYZ efflux pump contributed resistance to aminoglycosides and trimethoprim-sulfamethoxazole. Inactivation of smeYZ resulted in attenuation of oxidative stress susceptibility, swimming, flagella formation, biofilm formation, and secreted protease activity. Furthermore, loss of SmeYZ increased susceptibility to human serum and neutrophils and decreased in vivo virulence in a murine model. These findings suggest the possibility of attenuation of the resistance and virulence of S. maltophilia with inhibitors of the SmeYZ efflux pump. PMID:25918140

  20. Abundance of the Quorum-Sensing Factor Ax21 in Four Strains of Stenotrophomonas maltophilia Correlates with Mortality Rate in a New Zebrafish Model of Infection

    PubMed Central

    Yero, Daniel; Mongiardini, Elías; Torrent, Gerard; Huedo, Pol; Martínez, Paula; Roher, Nerea; Mackenzie, Simon; Gibert, Isidre; Daura, Xavier

    2013-01-01

    Stenotrophomonas maltophilia is a Gram-negative pathogen with emerging nosocomial incidence. Little is known about its pathogenesis and the genomic diversity exhibited by clinical isolates complicates the study of pathogenicity and virulence factors. Here, we present a strategy to identify such factors in new clinical isolates of S. maltophilia, incorporating an adult-zebrafish model of S. maltophilia infection to evaluate relative virulence coupled to 2D difference gel electrophoresis to explore underlying differences in protein expression. In this study we report upon three recent clinical isolates and use the collection strain ATCC13637 as a reference. The adult-zebrafish model shows discrimination capacity, i.e. from very low to very high mortality rates, with clinical symptoms very similar to those observed in natural S. maltophilia infections in fish. Strain virulence correlates with resistance to human serum, in agreement with previous studies in mouse and rat and therefore supporting zebrafish as a replacement model. Despite its clinical origin, the collection strain ATCC13637 showed obvious signs of attenuation in zebrafish, with null mortality. Multilocus-sequence-typing analysis revealed that the most virulent strains, UV74 and M30, exhibit the strongest genetic similitude. Differential proteomic analysis led to the identification of 38 proteins with significantly different abundance in the three clinical strains relative to the reference strain. Orthologs of several of these proteins have been already reported to have a role in pathogenesis, virulence or resistance mechanisms thus supporting our strategy. Proof of concept is further provided by protein Ax21, whose abundance is shown here to be directly proportional to mortality in the zebrafish infection model. Indeed, recent studies have demonstrated that this protein is a quorum-sensing-related virulence factor. PMID:23840626

  1. In vitro efficacy of copper and silver ions in eradicating Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii: implications for on-site disinfection for hospital infection control.

    PubMed

    Huang, Hsin-I; Shih, Hsiu-Yun; Lee, Chien-Ming; Yang, Thomas C; Lay, Jiunn-Jyi; Lin, Yusen E

    2008-01-01

    Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii are major opportunistic waterborne pathogens causing hospital-acquired infections. Copper-silver ionization has been shown to be effective in controlling Legionella colonization in hospital water systems. The objective was to determine the efficacy of copper and silver ions alone and in combination in eradicating P. aeruginosa, S. maltophilia and A. baumannii at the concentration applied to Legionella control. Kill curve experiments and mathematical modeling were conducted at copper and silver ion concentrations of 0.1, 0.2, 0.4, 0.8 and 0.01, 0.02, 0.04, 0.08 mg/L, respectively. The combinations of copper and silver ions were tested at concentrations of 0.2/0.02 and 0.4/0.04 mg/L, respectively. Initial organism concentration was ca. of 3 x 10(6)cfu/mL, and viability of the test organisms was assessed at predetermined time intervals. Samples (0.1 mL) withdrawn were mixed with 10 microL neutralizer solution immediately, serially diluted and plated in duplicate onto blood agar plates. The culture plates were incubated for 48 h at 37 degrees C and enumerated for the cfu (detection limit 10 cfu/mL). The results showed all copper ion concentrations tested (0.1-0.8 mg/L) achieved more than 99.999% reduction of P. aeruginosa which appears to be more susceptible to copper ions than S. maltophilia and A. baumannii. Silver ions concentration of 0.08 mg/L achieved more than 99.999% reduction of P. aeruginosa, S. maltophilia and A. baumannii in 6, 12 and 96 h, respectively. Combination of copper and silver ions exhibited a synergistic effect against P. aeruginosa and A. baumannii while the combination exhibited an antagonistic effect against S. maltophilia. Ionization may have a potential to eradicate P. aeruginosa, S. maltophilia and A. baumannii from hospital water systems. PMID:17655912

  2. High activity catechol 1,2-dioxygenase from Stenotrophomonas maltophilia strain KB2 as a useful tool in cis,cis-muconic acid production.

    PubMed

    Guzik, Urszula; Hupert-Kocurek, Katarzyna; Sitnik, Małgorzata; Wojcieszyńska, Danuta

    2013-06-01

    This is the first report of a catechol 1,2-dioxygenase from Stenotrophomonas maltophilia strain KB2 with high activity against catechol and its methyl derivatives. This enzyme was maximally active at pH 8.0 and 40 °C and the half-life of the enzyme at this temperature was 3 h. Kinetic studies showed that the value of K m and V max was 12.8 μM and 1,218.8 U/mg of protein, respectively. During our studies on kinetic properties of the catechol 1,2-dioxygenase we observed substrate inhibition at >80 μM. The nucleotide sequence of the gene encoding the S. maltophilia strain KB2 catechol 1,2-dioxygenase has high identity with other catA genes from members of the genus Pseudomonas. The deduced 314-residue sequence of the enzyme corresponds to a protein of molecular mass 34.5 kDa. This enzyme was inhibited by competitive inhibitors (phenol derivatives) only by ca. 30 %. High tolerance against condition changes is desirable in industrial processes. Our data suggest that this enzyme could be of use as a tool in production of cis,cis-muconic acid and its derivatives. PMID:23536173

  3. The effect of imipenem and diffusible signaling factors on the secretion of outer membrane vesicles and associated Ax21 proteins in Stenotrophomonas maltophilia.

    PubMed

    Devos, Simon; Van Oudenhove, Laurence; Stremersch, Stephan; Van Putte, Wouter; De Rycke, Riet; Van Driessche, Gonzalez; Vitse, Jolien; Raemdonck, Koen; Devreese, Bart

    2015-01-01

    Outer membrane vesicles (OMVs) are small nanoscale structures that are secreted by bacteria and that can carry nucleic acids, proteins, and small metabolites. They can mediate intracellular communication and play a role in virulence. In this study, we show that treatment with the β-lactam antibiotic imipenem leads to a dramatic increase in the secretion of outer membrane vesicles in the nosocomial pathogen Stenotrophomonas maltophilia. Proteomic analysis of their protein content demonstrated that the OMVs contain the chromosomal encoded L1 metallo-β-lactamase and L2 serine-β-lactamase. Moreover, the secreted OMVs contain large amounts of two Ax21 homologs, i.e., outer membrane proteins known to be involved in virulence and biofilm formation. We show that OMV secretion and the levels of Ax21 in the OMVs are dependent on the quorum sensing diffusible signal system (DSF). More specific, we demonstrate that the S. maltophilia DSF cis-Δ2-11-methyl-dodecenoic acid and, to a lesser extent, the Burkholderia cenocepacia DSF cis-Δ2-dodecenoic acid, stimulate OMV secretion. By a targeted proteomic analysis, we confirmed that DSF-induced OMVs contain large amounts of the Ax21 homologs, but not the β-lactamases. This work illustrates that both quorum sensing and disturbance of the peptidoglycan biosynthesis provoke the release of OMVs and that OMV content is context dependent. PMID:25926824

  4. The effect of imipenem and diffusible signaling factors on the secretion of outer membrane vesicles and associated Ax21 proteins in Stenotrophomonas maltophilia

    PubMed Central

    Devos, Simon; Van Oudenhove, Laurence; Stremersch, Stephan; Van Putte, Wouter; De Rycke, Riet; Van Driessche, Gonzalez; Vitse, Jolien; Raemdonck, Koen; Devreese, Bart

    2015-01-01

    Outer membrane vesicles (OMVs) are small nanoscale structures that are secreted by bacteria and that can carry nucleic acids, proteins, and small metabolites. They can mediate intracellular communication and play a role in virulence. In this study, we show that treatment with the β-lactam antibiotic imipenem leads to a dramatic increase in the secretion of outer membrane vesicles in the nosocomial pathogen Stenotrophomonas maltophilia. Proteomic analysis of their protein content demonstrated that the OMVs contain the chromosomal encoded L1 metallo-β-lactamase and L2 serine-β-lactamase. Moreover, the secreted OMVs contain large amounts of two Ax21 homologs, i.e., outer membrane proteins known to be involved in virulence and biofilm formation. We show that OMV secretion and the levels of Ax21 in the OMVs are dependent on the quorum sensing diffusible signal system (DSF). More specific, we demonstrate that the S. maltophilia DSF cis-Δ2-11-methyl-dodecenoic acid and, to a lesser extent, the Burkholderia cenocepacia DSF cis-Δ2-dodecenoic acid, stimulate OMV secretion. By a targeted proteomic analysis, we confirmed that DSF-induced OMVs contain large amounts of the Ax21 homologs, but not the β-lactamases. This work illustrates that both quorum sensing and disturbance of the peptidoglycan biosynthesis provoke the release of OMVs and that OMV content is context dependent. PMID:25926824

  5. Systematic Mutational Analysis of Histidine Kinase Genes in the Nosocomial Pathogen Stenotrophomonas maltophilia Identifies BfmAK System Control of Biofilm Development.

    PubMed

    Zheng, Liu; Wang, Fang-Fang; Ren, Bao-Zhen; Liu, Wei; Liu, Zhong; Qian, Wei

    2016-04-15

    The Gram-negative bacteriumStenotrophomonas maltophilialives in diverse ecological niches. As a result of its formidable capabilities of forming biofilm and its resistance to multiple antibiotic agents, the bacterium is also a nosocomial pathogen of serious threat to the health of patients whose immune systems are suppressed or compromised. Besides the histidine kinase RpfC, the two-component signal transduction system (TCS), which is the canonical regulatory machinery used by most bacterial pathogens, has never been experimentally investigated inS. maltophilia Here, we annotated 62 putative histidine kinase genes in theS. maltophiliagenome and successfully obtained 51 mutants by systematical insertional inactivation. Phenotypic characterization identified a series of mutants with deficiencies in bacterial growth, swimming motility, and biofilm development. A TCS, named here BfmA-BfmK (Smlt4209-Smlt4208), was genetically confirmed to regulate biofilm formation inS. maltophilia Together with interacting partner prediction and chromatin immunoprecipitation screens, six candidate promoter regions bound by BfmAin vivowere identified. We demonstrated that, among them, BfmA acts as a transcription factor that binds directly to the promoter regions ofbfmA-bfmKandSmlt0800(acoT), a gene encoding an acyl coenzyme A thioesterase that is associated with biofilm development, and positively controls their transcription. Genome-scale mutational analyses of histidine kinase genes and functional dissection of BfmK-BfmA regulation in biofilm provide genetic information to support more in-depth studies on cellular signaling inS. maltophilia, in the context of developing novel approaches to fight this important bacterial pathogen. PMID:26873318

  6. Type II Secretion-Dependent Degradative and Cytotoxic Activities Mediated by Stenotrophomonas maltophilia Serine Proteases StmPr1 and StmPr2.

    PubMed

    DuMont, Ashley L; Karaba, Sara M; Cianciotto, Nicholas P

    2015-10-01

    Stenotrophomonas maltophilia is an emerging opportunistic pathogen that primarily causes pneumonia and bacteremia in immunocompromised individuals. We recently reported that S. maltophilia strain K279a encodes the Xps type II secretion system and that Xps promotes rounding, actin rearrangement, detachment, and death in the human lung epithelial cell line A549. Here, we show that Xps-dependent cell rounding and detachment occur with multiple human and murine cell lines and that serine protease inhibitors block Xps-mediated rounding and detachment of A549 cells. Using genetic analysis, we determined that the serine proteases StmPr1 and StmPr2, which were confirmed to be Xps substrates, are predominantly responsible for secreted proteolytic activities exhibited by strain K279a, as well as the morphological and cytotoxic effects on A549 cells. Supernatants from strain K279a also promoted the degradation of type I collagen, fibrinogen, and fibronectin in a predominantly Xps- and protease-dependent manner, although some Xps-independent degradation of fibrinogen was observed. Finally, Xps, and predominantly StmPr1, degraded interleukin 8 (IL-8) secreted by A549 cells during coculture with strain K279a. Our findings indicate that while StmPr1 and StmPr2 are predominantly responsible for A549 cell rounding, extracellular matrix protein degradation, and IL-8 degradation, additional Xps substrates also contribute to these activities. Altogether, our data provide new insight into the virulence potential of the S. maltophilia Xps type II secretion system and its StmPr1 and StmPr2 substrates. PMID:26169274

  7. Type II Secretion-Dependent Degradative and Cytotoxic Activities Mediated by Stenotrophomonas maltophilia Serine Proteases StmPr1 and StmPr2

    PubMed Central

    DuMont, Ashley L.; Karaba, Sara M.

    2015-01-01

    Stenotrophomonas maltophilia is an emerging opportunistic pathogen that primarily causes pneumonia and bacteremia in immunocompromised individuals. We recently reported that S. maltophilia strain K279a encodes the Xps type II secretion system and that Xps promotes rounding, actin rearrangement, detachment, and death in the human lung epithelial cell line A549. Here, we show that Xps-dependent cell rounding and detachment occur with multiple human and murine cell lines and that serine protease inhibitors block Xps-mediated rounding and detachment of A549 cells. Using genetic analysis, we determined that the serine proteases StmPr1 and StmPr2, which were confirmed to be Xps substrates, are predominantly responsible for secreted proteolytic activities exhibited by strain K279a, as well as the morphological and cytotoxic effects on A549 cells. Supernatants from strain K279a also promoted the degradation of type I collagen, fibrinogen, and fibronectin in a predominantly Xps- and protease-dependent manner, although some Xps-independent degradation of fibrinogen was observed. Finally, Xps, and predominantly StmPr1, degraded interleukin 8 (IL-8) secreted by A549 cells during coculture with strain K279a. Our findings indicate that while StmPr1 and StmPr2 are predominantly responsible for A549 cell rounding, extracellular matrix protein degradation, and IL-8 degradation, additional Xps substrates also contribute to these activities. Altogether, our data provide new insight into the virulence potential of the S. maltophilia Xps type II secretion system and its StmPr1 and StmPr2 substrates. PMID:26169274

  8. [Investigation of the presence of class 1, 2, 3 integrons and their relationships with antibiotic resistance in clinical Stenotrophomonas maltophilia isolates].

    PubMed

    Usta, Egemen; Eroğlu, Cafer; Yanık, Keramettin; Karadağ, Adil; Güney, Akif Koray; Günaydın, Murat

    2015-01-01

    Stenotrophomonas maltophilia is an opportunistic emergent pathogen causing hospital-acquired infections. It is resistant to majority of the broad spectrum antibiotics due to several mechanisms which significantly limit the treatment options. Although the relationship between integrons, mobile genetic elements which play role in transferring resistance genes, and the antibiotic resistance in different gram-negative bacteria have been investigated, the data are limited in Turkey especially for S.maltophilia. The aims of this study were to detect the presence of different classes of integrons and plasmids in clinical isolates of S.maltophilia and to investigate the antibiotic resistance profiles of those isolates. One hundred S.maltophilia strains isolated from various clinical samples (32 sputum, 25 tracheal aspirates, 9 urine and blood, 7 exudates and catheters, 4 sterile body fluids and wounds, 2 CSF, 1 conjunctiva) in our microbiology laboratory during January 2011-September 2012, were included in the study. The isolates were identified by VITEK2 Compact (BioMerieux, France) or Phoenix 100 (BD, USA) automatized systems, and the susceptibilities of the strains to levofloxacin, chloramphenicol, ceftazidime and trimethoprim/sulfamethoxazol (SXT) were evaluated via broth microdilution method according to the CLSI recommendations. Class 1 (intI-1), class 2 (intI-2), class 3 (intI-3) integron gene cassettes and integron 5'-3' conserved gene regions (intI-5'-3'CS) were investigated by polymerase chain reaction (PCR) using specific primers in all of the strains. Nucleotide sequence analysis of PCR products was performed in case of positive result, and the presence and size of plasmids were further investigated. The susceptibility rates of S.maltophilia strains to ceftazidime, chloramphenicol, SXT and levofloxacin were found as 24%, 66%, 93% and 95%, respectively, while MIC(50) and MIC(90) values were 64-128 µg/ml, 8-16 µg/ml, 1/19-2/38 µg/ml and 1-2 µg/ml, respectively. In PCR amplification with intI-1, intI-2 and intI-3 primers, 12%, 2% and 10% of the isolates yielded expectative bands, respectively. DNA sequence analysis of the amplified products revealed five isolates to harbour intI-1 gene, while intI class 2 and class 3 genes were not detected in any of the strains. Furthermore in PCR amplification with intI-5'CS and 3'CS primers, 20% of the strains yielded expected bands. Sequence analysis of these amplicons revealed the presence of quaternary ammonium compound resistance protein genes (qacL) in two, aminoglycoside adenyltransferase gene (aadA) in one and integron-associated recombination site (attI1) genes in five strains. Additionally, the presence of plasmids have been detected in 9 (9%) of the strains, however all of them was integron-negative. The sizes of plasmids were 2340, 1350, 2760, 18600, 20000, 3570-2540, 2510 and 5000-2540 base pairs, respectively. When the antibiotic susceptibility patterns of strains were compared with the presence of intI gene regions, no statistically significant relationship was observed (p> 0.05). In conclusion, the demonstration of integron class 1 genes and plasmids among clinical S.maltophilia strains is regarded as a warning data to indicate the potential for spread of those resistant strains in our hospital. PMID:25706729

  9. Biodegradation of wool waste and keratinase production in scale-up fermenter with different strategies by Stenotrophomonas maltophilia BBE11-1.

    PubMed

    Fang, Zhen; Zhang, Juan; Liu, Baihong; Du, Guocheng; Chen, Jian

    2013-07-01

    A keratin-degrading strain Stenotrophomonas maltophilia BBE11-1 was grown in a 3-L batch fermenter containing wool waste as the main medium and cell growth rate was determined as the key factor to affect keratinase yield. Three strategies of temperature-shift procedure, two-stage DO control and fed-batch process were used to change growth rate. And a 62.2% improvement of keratinase yield was achieved. With the glucose fed-batch procedure in 30-L fermenter, keratinase production was significantly improved up to 117.7% (1728 U/ml) as compared with initial data (793.8 U/ml) in a 3-L fermenter and with much shortened fermentation time within 18 h. Significant structure changes and high levels of free amino acids from wool decomposition indicated the possible applications for wool waste management and fertilizer industry. The remarkable digestion of wool cuticle also suggested its potential utilization in textile industry. PMID:23708787

  10. The problem of a solvent exposable disulfide when preparing Co(II)-substituted metallo-beta-lactamase L1 from Stenotrophomonas maltophilia.

    PubMed

    Crowder, M W; Yang, K W; Carenbauer, A L; Periyannan, G; Seifert, M E; Rude, N E; Walsh, T R

    2001-01-01

    In an effort to prepare Co(II)-substituted metallo-beta-lactamase L1 from Stenotrophomonas maltophilia for future spectroscopic and mechanistic studies, two methods for the preparation of Co(II)-L1 were tested. Method A involved adding CoCl2 directly to apo-L1 under anaerobic conditions. The resulting enzyme contained 1.9 moles of cobalt and exhibited very little activity, and UV-Vis, 1H NMR, and EPR studies indicated that most of the cobalt in this sample was Co(III). Method B involved reducing the single and unique disulfide bridge in L1 with tris(carboxyethyl)phosphine prior to adding CoCl2. The resulting enzyme was pink, contained 2.5 moles of cobalt per mole of enzyme, and exhibited kcat and Km values of 18+1 s(-1) and 10+/-1 microM, respectively, when using nitrocefin as the substrate. UV-Vis, 1H NMR, and EPR studies revealed that this enzyme sample contained high-spin Co(II). The UV-Vis spectra also provided evidence for Co(II) bound to one or both of the reduced cysteines. Efforts to block this non-specific Co(II) binding site using a chemical modification agent or site-directed mutagenesis were unsuccessful. The data presented here demonstrate the problem of solvent-exposed disulfides when preparing Co(II)-substituted enzymes and offers a convenient method to circumvent the problem. PMID:11191226

  11. Copper Enhanced Monooxygenase Activity and FT-IR Spectroscopic Characterisation of Biotransformation Products in Trichloroethylene Degrading Bacterium: Stenotrophomonas maltophilia PM102

    PubMed Central

    Mukherjee, Piyali; Roy, Pranab

    2013-01-01

    Stenotrophomonas maltophilia PM102 (NCBI GenBank Acc. no. JQ797560) is capable of growth on trichloroethylene as the sole carbon source. In this paper, we report the purification and characterisation of oxygenase present in the PM102 isolate. Enzyme activity was found to be induced 10.3-fold in presence of 0.7 mM copper with a further increment to 14.96-fold in presence of 0.05 mM NADH. Optimum temperature for oxygenase activity was recorded at 36°C. The reported enzyme was found to have enhanced activity at pH 5 and pH 8, indicating presence of two isoforms. Maximum activity was seen on incubation with benzene compared to other substrates like TCE, chloroform, toluene, hexane, and petroleum benzene. Km and Vmax for benzene were 3.8 mM and 340 U/mg/min and those for TCE were 2.1 mM and 170 U/mg/min. The crude enzyme was partially purified by ammonium sulphate precipitation followed by dialysis. Zymogram analysis revealed two isoforms in the 70% purified enzyme fraction. The activity stain was more prominent when the native gel was incubated in benzene as substrate in comparison to TCE. Crude enzyme and purified enzyme fractions were assayed for TCE degradation by the Fujiwara test. TCE biotransformation products were analysed by FT-IR spectroscopy. PMID:24083236

  12. Evaluation of Trimethoprim/Sulfamethoxazole (SXT), Minocycline, Tigecycline, Moxifloxacin, and Ceftazidime Alone and in Combinations for SXT-Susceptible and SXT-Resistant Stenotrophomonas maltophilia by In Vitro Time-Kill Experiments

    PubMed Central

    Cai, Xuejiu; Zhao, Jin; Cui, Junchang

    2016-01-01

    Background The optimal therapy for infections caused by Stenotrophomonas maltophilia (S. maltophilia) has not yet been established. The objective of our study was to evaluate the efficacy of trimethoprim/sulfamethoxazole (SXT), minocycline, tigecycline, moxifloxacin, levofloxacin, ticarcillin-clavulanate, polymyxin E, chloramphenicol, and ceftazidime against clinical isolated S. maltophilia strains by susceptibility testing and carried out time-kill experiments in potential antimicrobials. Methods The agar dilution method was used to test susceptibility of nine candidate antimicrobials, and time-killing experiments were carried out to evaluate the efficacy of SXT, minocycline, tigecycline, moxifloxacin, levofloxacin, and ceftazidime both alone and in combinations at clinically relevant antimicrobial concentrations. Results The susceptibility to SXT, minocycline, tigecycline, moxifloxacin, levofloxacin, ticarcillin-clavulanate, chloramphenicol, polymyxin E, and ceftazidime were 93.8%, 95.0%, 83.8%, 80.0%, 76.3%, 76.3%, 37.5%, 22.5%, and 20.0% against 80 clinical consecutively isolated strains, respectively. Minocycline and tigecycline showed consistent active against 22 SXT-resistant strains. However, resistance rates were high in the remaining antimicrobial agents against SXT-resistant strains. In time-kill experiments, there were no synergisms in most drug combinations in time-kill experiments. SXT plus moxifloxacin displayed synergism when strains with low moxifloxacin MICs. Moxifloxacin plus Minocycline and moxifloxacin plus tigecycline displayed synergism in few strains. No antagonisms were found in these combinations. Overall, compared with single drug, the drug combinations demonstrated lower bacterial concentrations. Some combinations showed bactericidal activity. Conclusions In S. maltophilia infections, susceptibility testing suggests that minocycline and SXT may be considered first-line therapeutic choices while tigecycline, moxifloxacin, levofloxacin, and ticarcillin-clavulanate may serve as second-line choices. Ceftazidime, colistin, and chloramphenicol show poor active against S. maltophilia. However, monotherapy is inadequate in infection management, especially in case of immunocompromised patients. Combination therapy, especially SXT plus moxifloxacin, may benefit than monotherapy in inhibiting or killing S. maltophilia. PMID:26999818

  13. Regulation by SoxR of mfsA, Which Encodes a Major Facilitator Protein Involved in Paraquat Resistance in Stenotrophomonas maltophilia

    PubMed Central

    Srijaruskul, Kriangsuk; Charoenlap, Nisanart; Namchaiw, Poommaree; Chattrakarn, Sorayut; Giengkam, Suparat; Mongkolsuk, Skorn; Vattanaviboon, Paiboon

    2015-01-01

    Stenotrophomonas maltophilia MfsA (Smlt1083) is an efflux pump in the major facilitator superfamily (MFS). Deletion of mfsA renders the strain more susceptible to paraquat, but no alteration in the susceptibility levels of other oxidants is observed. The expression of mfsA is inducible upon challenge with redox cycling/superoxide-generating drug (paraquat, menadione and plumbagin) treatments and is directly regulated by SoxR, which is a transcription regulator and sensor of superoxide-generating agents. Analysis of mfsA expression patterns in wild-type and a soxR mutant suggests that oxidized SoxR functions as a transcription activator of the gene. soxR (smlt1084) is located in a head-to-head fashion with mfsA, and these genes share the -10 motif of their promoter sequences. Purified SoxR specifically binds to the putative mfsA promoter motifs that contain a region that is highly homologous to the consensus SoxR binding site, and mutation of the SoxR binding site abolishes binding of purified SoxR protein. The SoxR box is located between the putative -35 and -10 promoter motifs of mfsA; and this position is typical for a promoter in which SoxR acts as a transcriptional activator. At the soxR promoter, the SoxR binding site covers the transcription start site of the soxR transcript; thus, binding of SoxR auto-represses its own transcription. Taken together, our results reveal for the first time that mfsA is a novel member of the SoxR regulon and that SoxR binds and directly regulates its expression. PMID:25915643

  14. Effects of Endobacterium (Stenotrophomonas maltophilia) on Pathogenesis-Related Gene Expression of Pine Wood Nematode (Bursaphelenchus xylophilus) and Pine Wilt Disease.

    PubMed

    He, Long-Xi; Wu, Xiao-Qin; Xue, Qi; Qiu, Xiu-Wen

    2016-01-01

    Pine wilt disease (PWD) caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus, is responsible for devastating epidemics in pine trees in Asia and Europe. Recent studies showed that bacteria carried by the PWN might be involved in PWD. However, the molecular mechanism of the interaction between bacteria and the PWN remained unclear. Now that the whole genome of B. xylophilus (Bursaphelenchus xylophilus) is published, transcriptome analysis is a unique method to study the role played by bacteria in PWN. In this study, the transcriptome of aseptic B. xylophilus, B. xylophilus treated with endobacterium (Stenotrophomonas maltophilia NSPmBx03) and fungus B. xylophilus were sequenced. We found that 61 genes were up-regulated and 830 were down-regulated in B. xylophilus after treatment with the endobacterium; 178 genes were up-regulated and 1122 were down-regulated in fungus B. xylophilus compared with aseptic B. xylophilus. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were used to study the significantly changed biological functions and pathways for these differentially expressed genes. Many pathogenesis-related genes, including glutathinone S-transferase, pectate lyase, ATP-binding cassette transporter and cytochrome P450, were up-regulated after B. xylophilus were treated with the endobacterium. In addition, we found that bacteria enhanced the virulence of PWN. These findings indicate that endobacteria might play an important role in the development and virulence of PWN and will improve our understanding of the regulatory mechanisms involved in the interaction between bacteria and the PWN. PMID:27231904

  15. Regulation by SoxR of mfsA, Which Encodes a Major Facilitator Protein Involved in Paraquat Resistance in Stenotrophomonas maltophilia.

    PubMed

    Srijaruskul, Kriangsuk; Charoenlap, Nisanart; Namchaiw, Poommaree; Chattrakarn, Sorayut; Giengkam, Suparat; Mongkolsuk, Skorn; Vattanaviboon, Paiboon

    2015-01-01

    Stenotrophomonas maltophilia MfsA (Smlt1083) is an efflux pump in the major facilitator superfamily (MFS). Deletion of mfsA renders the strain more susceptible to paraquat, but no alteration in the susceptibility levels of other oxidants is observed. The expression of mfsA is inducible upon challenge with redox cycling/superoxide-generating drug (paraquat, menadione and plumbagin) treatments and is directly regulated by SoxR, which is a transcription regulator and sensor of superoxide-generating agents. Analysis of mfsA expression patterns in wild-type and a soxR mutant suggests that oxidized SoxR functions as a transcription activator of the gene. soxR (smlt1084) is located in a head-to-head fashion with mfsA, and these genes share the -10 motif of their promoter sequences. Purified SoxR specifically binds to the putative mfsA promoter motifs that contain a region that is highly homologous to the consensus SoxR binding site, and mutation of the SoxR binding site abolishes binding of purified SoxR protein. The SoxR box is located between the putative -35 and -10 promoter motifs of mfsA; and this position is typical for a promoter in which SoxR acts as a transcriptional activator. At the soxR promoter, the SoxR binding site covers the transcription start site of the soxR transcript; thus, binding of SoxR auto-represses its own transcription. Taken together, our results reveal for the first time that mfsA is a novel member of the SoxR regulon and that SoxR binds and directly regulates its expression. PMID:25915643

  16. Potential novel therapeutic strategies in cystic fibrosis: antimicrobial and anti-biofilm activity of natural and designed α-helical peptides against Staphylococcus aureus, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia

    PubMed Central

    2012-01-01

    Background Treatment of cystic fibrosis-associated lung infections is hampered by the presence of multi-drug resistant pathogens, many of which are also strong biofilm producers. Antimicrobial peptides, essential components of innate immunity in humans and animals, exhibit relevant in vitro antimicrobial activity although they tend not to select for resistant strains. Results Three α-helical antimicrobial peptides, BMAP-27 and BMAP-28 of bovine origin, and the artificial P19(9/B) peptide were tested, comparatively to Tobramycin, for their in vitro antibacterial and anti-biofilm activity against 15 Staphylococcus aureus, 25 Pseudomonas aeruginosa, and 27 Stenotrophomonas maltophilia strains from cystic fibrosis patients. All assays were carried out in physical-chemical experimental conditions simulating a cystic fibrosis lung. All peptides showed a potent and rapid bactericidal activity against most P. aeruginosa, S. maltophilia and S. aureus strains tested, at levels generally higher than those exhibited by Tobramycin and significantly reduced biofilm formation of all the bacterial species tested, although less effectively than Tobramycin did. On the contrary, the viability-reducing activity of antimicrobial peptides against preformed P. aeruginosa biofilms was comparable to and, in some cases, higher than that showed by Tobramycin. Conclusions The activity shown by α-helical peptides against planktonic and biofilm cells makes them promising “lead compounds” for future development of novel drugs for therapeutic treatment of cystic fibrosis lung disease. PMID:22823964

  17. Genome Sequence of Type Strains of Genus Stenotrophomonas

    PubMed Central

    Patil, Prashant P.; Midha, Samriti; Kumar, Sanjeet; Patil, Prabhu B.

    2016-01-01

    Genomic resource of type strains and historically important strains of genus Stenotrophomonas allowed us to reveal the existence of 18 distinct species by applying modern phylogenomic criterions. Apart from Stenotrophomonas maltophilia, S. africana represents another species of clinical importance. Interestingly, Pseudomonas hibsicola, P. beteli, and S. pavani that are of plant origin are closer to S. maltophilia than the majority of the environmental isolates. The genus has an open pan-genome. By providing the case study on genes encoding metallo-β-lactamase and Clustered Regularly Interspaced Short Palindrome Repeats (CRISPR) regions, we have tried to show the importance of this genomic dataset in understanding its ecology. PMID:27014232

  18. Interplay among membrane-bound lytic transglycosylase D1, the CreBC two-component regulatory system, the AmpNG-AmpDI-NagZ-AmpR regulatory circuit, and L1/L2 β-lactamase expression in Stenotrophomonas maltophilia.

    PubMed

    Huang, Yi-Wei; Wu, Chao-Jung; Hu, Rouh-Mei; Lin, Yi-Tsung; Yang, Tsuey-Ching

    2015-11-01

    Lytic transglycosylases (LTs) are an important class of enzymes involved in peptidoglycan (PG) cleavage, with the concomitant formation of an intramolecular 1,6-anhydromuramoyl reaction product. There are six annotated LT genes in the Stenotrophomonas maltophilia genome, including genes for five membrane-bound LTs (mltA, mltB1, mltB2, mltD1, and mltD2) and a gene for soluble LT (slt). Six LTs of S. maltophilia KJ were systematically mutated, yielding the ΔmltA, ΔmltB1, ΔmltB2, ΔmltD1, ΔmltD2, and Δslt mutants. Inactivation of mltD1 conferred a phenotype of elevated uninduced β-lactamase activity. The underlying mechanism responsible for this phenotype was elucidated by the construction of several mutants and determination of β-lactamase activity. The expression of the genes assayed was assessed by quantitative reverse transcriptase PCR and a promoter transcription fusion assay. The results demonstrate that ΔmltD1 mutant-mediated L1/L2 β-lactamase expression involved the creBC two-component regulatory system (TCS) and the ampNG-ampDI-nagZ-ampR regulatory circuit. The inactivation of mltD1 resulted in mltB1 and mltD2 upexpression in a creBC- and ampNG-dependent manner. The overexpressed MltB1 and MltD2 activity contributed to the expression of the L1/L2 β-lactamase genes via the ampNG-ampDI-nagZ-ampR regulatory circuit. These findings reveal, for the first time, a linkage between LTs, the CreBC TCS, the ampNG-ampDI-nagZ-ampR regulatory circuit, and L1/L2 β-lactamase expression in S. maltophilia. PMID:26282431

  19. Stenotrophomonas, Mycobacterium, and Streptomyces in home dust and air: associations with moldiness and other home/family characteristics

    EPA Science Inventory

    Abstract Aims: (1) To investigate the dustborne and airborne bacterial concentrations of three emerging moisture-related bacteria: Stenotrophomonas maltophilia, Streptomyces, and Mycobacterium. (2) To study the association between these bacteria concentrations and Environmenta...

  20. The versatility and adaptation of bacteria from the genus Stenotrophomonas

    SciTech Connect

    Ryan, R.P.; van der Lelie, D.; Monchy, S.; Cardinale, M.; Taghavi, S.; Crossman, L.; Avison, M. B.; Berg, G.; Dow, J. M.

    2009-07-01

    The genus Stenotrophomonas comprises at least eight species. These bacteria are found throughout the environment, particularly in close association with plants. Strains of the most predominant species, Stenotrophomonas maltophilia, have an extraordinary range of activities that include beneficial effects for plant growth and health, the breakdown of natural and man-made pollutants that are central to bioremediation and phytoremediation strategies and the production of biomolecules of economic value, as well as detrimental effects, such as multidrug resistance, in human pathogenic strains. Here, we discuss the versatility of the bacteria in the genus Stenotrophomonas and the insight that comparative genomic analysis of clinical and endophytic isolates of S. maltophilia has brought to our understanding of the adaptation of this genus to various niches.

  1. Phylogenetic Analysis of Stenotrophomonas spp. Isolates Contributes to the Identification of Nosocomial and Community-Acquired Infections

    PubMed Central

    Cerezer, Vinicius Godoy; Pasternak, Jacyr; Franzolin, Marcia Regina; Moreira-Filho, Carlos Alberto

    2014-01-01

    Stenotrophomonas ssp. has a wide environmental distribution and is also found as an opportunistic pathogen, causing nosocomial or community-acquired infections. One species, S. maltophilia, presents multidrug resistance and has been associated with serious infections in pediatric and immunocompromised patients. Therefore, it is relevant to conduct resistance profile and phylogenetic studies in clinical isolates for identifying infection origins and isolates with augmented pathogenic potential. Here, multilocus sequence typing was performed for phylogenetic analysis of nosocomial isolates of Stenotrophomonas spp. and, environmental and clinical strains of S. maltophilia. Biochemical and multidrug resistance profiles of nosocomial and clinical strains were determined. The inferred phylogenetic profile showed high clonal variability, what correlates with the adaptability process of Stenotrophomonas to different habitats. Two clinical isolates subgroups of S. maltophilia sharing high phylogenetic homogeneity presented intergroup recombination, thus indicating the high permittivity to horizontal gene transfer, a mechanism involved in the acquisition of antibiotic resistance and expression of virulence factors. For most of the clinical strains, phylogenetic inference was made using only partial ppsA gene sequence. Therefore, the sequencing of just one specific fragment of this gene would allow, in many cases, determining whether the infection with S. maltophilia was nosocomial or community-acquired. PMID:24818127

  2. Structure of Aminodeoxychorismate Synthase from Stenotrophomonas maltophilia†

    PubMed Central

    Bera, Asim K.; Atanasova, Vesna; Dhanda, Anjali; Ladner, Jane E.; Parsons, James F.

    2012-01-01

    PabB, aminodeoxychorismate synthase, is the chorismic acid binding component of the heterodimeric PabAB complex that converts chorismic acid to 4-amino-4-deoxychorismate, a precursor of p-aminobenzoate and folic acid in microorganisms. The second component, a glutamine amidotransferase subunit, PabA, generates ammonia that is channeled to the PabB active site where it attacks the C4 carbon of a chorismate derived intermediate that is covalently bound, through C2, to an active site lysine residue. The presence of a PIKGT motif was, until recently, believed to be discriminate PabB enzymes from the closely related enzyme anthranilate synthase, which typically contains a PIAGT active site motif and does not form a covalent enzyme-substrate intermediate with chorismate. A subclass of PabB enzymes that employ an alternative mechanism requiring two equivalents of ammonia from glutamine and that feature a noncovalently bound 2-amino-2-deoxyisochorismate intermediate was recently identified. Here we report the 2.25 Å crystal structure of PabB from the emerging pathogen Stenotrophomonas maltophilia. It is the first reported structure of a PabB that features the PIAGT motif. Surprisingly, no dedicated pabA is evident in the genome of S. maltophilia suggesting that another cellular amidotransferase is able to fulfill the role of PabA in this organism. Evaluation of the ammonia-dependent aminodeoxychorismate synthase activity of S. maltophilia PabB alone revealed that it is virtually inactive. However, in the presence of a heterologous PabA surrogate, typical levels of activity were observed using either glutamine or ammonia as the nitrogen source. Additionally, the structure suggests that a key segment of the polypeptide can remodel itself to interact with a nonspecialized or shared amidotransferase partner in vivo. The structure and mass spectral analysis further suggest that S. maltophilia PabB, like Escherichia coli PabB, binds tryptophan in a vestigial regulatory site. The observation that the binding site is unoccupied in the crystal structure, however, suggests the affinity may be low relative to E. coli PabB. PMID:23230967

  3. Stenotrophomonas and Lysobacter: ubiquitous plant-associated gamma-proteobacteria of developing significance in applied microbiology.

    PubMed

    Hayward, A C; Fegan, N; Fegan, M; Stirling, G R

    2010-03-01

    The exploration of new source materials and the use of alternative isolation and identification methods have led to rapid expansion in the knowledge of diversity; in Lysobacter, 11 new species having been described since 2005, and in Stenotrophomonas with six new species since 2000. The new species of Lysobacter, isolated by dilution and direct plating on standard media, differ in several key phenotypic properties from those obtained by enrichment on complex polysaccharides in the original description of the genus. Revision of the definition of the genus will be required. Both culture-dependent and culture-independent methods to assess community structure, in a variety of host and nonhost environments, have established that some species of Lysobacter are a dominant component of the microflora, where previously their presence had not been suspected. Culture-independent studies have generally not added new information on the occurrence and distribution of Stenotrophomonas maltophilia and other members of the genus, which are readily isolated on standard media from source materials. Lysobacter enzymogenes and Sten. maltophilia produce similar antibiotics and share some enzyme activities which, subject to safety considerations, may make them attractive candidates for use in biological control of plant diseases and of nematodes. PMID:19702860

  4. Characterization of Bacterial Cellulose by Gluconacetobacter hansenii CGMCC 3917.

    PubMed

    Feng, Xianchao; Ullah, Niamat; Wang, Xuejiao; Sun, Xuchun; Li, Chenyi; Bai, Yun; Chen, Lin; Li, Zhixi

    2015-10-01

    In this study, comprehensive characterization and drying methods on properties of bacterial cellulose were analyzed. Bacterial cellulose was prepared by Gluconacetobacter hansenii CGMCC 3917, which was mutated by high hydrostatic pressure (HHP) treatment. Bacterial cellulose is mainly comprised of cellulose Iα with high crystallinity and purity. High-water holding and absorption capacity were examined by reticulated structure. Thermogravimetric analysis showed high thermal stability. High tensile strength and Young's modulus indicated its mechanical properties. The rheological analysis showed that bacterial cellulose had good consistency and viscosity. These results indicated that bacterial cellulose is a potential food additive and also could be used for a food packaging material. The high textural stability during freeze-thaw cycles makes bacterial cellulose an effective additive for frozen food products. In addition, the properties of bacterial cellulose can be affected by drying methods. Our results suggest that the bacterial cellulose produced from HHP-mutant strain has an effective characterization, which can be used for a wide range of applications in food industry. PMID:26352877

  5. Meningitis due to Xanthomonas maltophilia.

    PubMed

    Girijaratnakumari, T; Raja, A; Ramani, R; Antony, B; Shivananda, P G

    1993-01-01

    During 1st week of post-operative period, a 28 year old female patient operated for left cerebellopontine angle tumor, continued to get fever. Lumbar puncture did not reveal any organisms. She responded to ciprofloxacin. Two months later, she was readmitted with signs and symptoms of meningitis. The CSF tapped on lumbar puncture grew Xanthomonas maltophilia, Gram negative bacilli, sensitive to various antibiotics, ciprofloxacin being one of them. The patient was given ciprofloxacin for 3 weeks. On follow up, a year later she was found to be asymptomatic. PMID:8051648

  6. De-novo synthesis of 2-phenylethanol by Enterobacter sp. CGMCC 5087

    PubMed Central

    2014-01-01

    Background 2-phenylethanl (2-PE) and its derivatives are important chemicals, which are widely used in food materials and fine chemical industries and polymers and its also a potentially valuable alcohol for next-generation biofuel. However, the biosynthesis of 2-PE are mainly biotransformed from phenylalanine, the price of which barred the production. Therefore, it is necessary to seek more sustainable technologies for 2-PE production. Results A new strain which produces 2-PE through the phenylpyruvate pathway was isolated and identified as Enterobacter sp. CGMCC 5087. The strain is able to use renewable monosaccharide as the carbon source and NH4Cl as the nitrogen source to produce 2-PE. Two genes of rate-limiting enzymes, chorismate mutase p-prephenate dehydratase (PheA) and 3-deoxy-d-arabino-heptulosonic acid 7-phosphate synthase (DAHP), were cloned from Escherichia coli and overexpressed in E. sp. CGMCC 5087. The engineered E. sp. CGMCC 5087 produces 334.9mgL-1 2-PE in 12h, which is 3.26 times as high as the wild strain. Conclusions The phenylpyruvate pathway and the substrate specificity of 2-keto-acid decarboxylase towards phenylpyruvate were found in E. sp. CGMCC 5087. Combined with the low-cost monosaccharide as the substrate, the finding provides a novel and potential way for 2-PE production. PMID:24766677

  7. Stenotrophomonas, Mycobacterium, and Streptomyces in home dust and air: Associations with moldiness and other home/family characteristics

    PubMed Central

    Kettleson, Eric; Kumar, Sudhir; Reponen, Tiina; Vesper, Stephen; Méheust, Delphine; Grinshpun, Sergey A.; Adhikari, Atin

    2013-01-01

    Respiratory illnesses have been linked to children’s exposures to water-damaged homes. Therefore, understanding the microbiome in water-damaged homes is critical to preventing these illnesses. Few studies have quantified bacterial contamination, especially specific species, in water-damaged homes. We collected air and dust samples in twenty-one low-mold homes and twenty-one high-mold homes. The concentrations of three bacteria/genera, Stenotrophomonas maltophilia, Streptomyces sp. and Mycobacterium sp., were measured in air and dust samples using quantitative PCR (QPCR). The concentrations of the bacteria measured in the air samples were not associated with any specific home characteristic based on multiple regression models. However, higher concentrations of S. maltophilia in the dust samples were associated with water damage, i.e. with higher floor surface moisture and higher concentrations of moisture-related mold species. The concentrations of Streptomyces and Mycobacterium sp. had similar patterns and may be partially determined by human and animal occupants and outdoor sources of these bacteria. PMID:23397905

  8. Central metabolic pathways of Aureobasidium pullulans CGMCC1234 for pullulan production.

    PubMed

    Sheng, Long; Liu, Chang; Tong, Qunyi; Ma, Meihu

    2015-12-10

    With the purpose of understanding the metabolic network of Aureobasidium pullulans, the central metabolic pathways were confirmed by the activities of the key enzymes involved in different pathways. The effect of different iodoacetic acid concentrations on pullulan fermentation was also investigated in this paper. The activities of phosphofructokinases and glucose-6-phosphate dehydrogenase existed in A. pullulans CGMCC1234, whereas 2-keto-3-deoxy-6-phosphogluconate aldolase activity was not detected. We proposed that the central metabolic pathways of A. pullulans CGMCC1234 included EMP and PPP, but no ED. Pullulan production declined fast as the iodoacetic acid increased, while cell growth offered upgrade firstly than descending latter tendency. Compared to the control group, the ratio of ATP/ADP of 0.60 mM iodoacetic acid group was lower at different stages of pullulan fermentation. The findings revealed that low concentration of iodoacetic acid might impel carbon flux flow toward the PPP, but reduce the flux of the EMP. PMID:26428132

  9. Stenotrophomonas, Achromobacter, and nonmelioid Burkholderia species: antimicrobial resistance and therapeutic strategies.

    PubMed

    Abbott, Iain J; Peleg, Anton Y

    2015-02-01

    Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and nonmelioid Burkholderia species, namely, Burkholderia cepacia complex, collectively are a group of troublesome nonfermenters. Although not inherently virulent organisms, these environmental Gram negatives can complicate treatment in those who are immunocompromised, critically ill in the intensive care unit and those patients with suppurative lung disease, such as cystic fibrosis. Through a range of intrinsic antimicrobial resistance mechanisms, virulence factors, and the ability to survive in biofilms, these opportunistic pathogens are well suited to persist, both in the environment and the host. Treatment recommendations are hindered by the difficulties in laboratory identification, the lack of reproducibility of antimicrobial susceptibility testing, the lack of clinical breakpoints, and the absence of clinical outcome data. Despite trimethoprim-sulfamethoxazole often being the mainstay of treatment, resistance is widely encountered, and alternative regimens, including combination therapy, are often used. This review will highlight the important aspects and unique challenges that these three nonfermenters pose, and, in the absence of clinical outcome data, our therapeutic recommendations will be based on reported antimicrobial susceptibility and pharmacokinetic/pharmacodynamic profiles. PMID:25643274

  10. Draft Genome Sequence of Pannonibacter phragmitetus Strain CGMCC9175, a Halotolerant Polycyclic Aromatic Hydrocarbon-Degrading Bacterium

    PubMed Central

    Jin, Decai; Zhou, Lisha; Zhang, Zhuo

    2016-01-01

    Pannonibacter phragmitetus CGMCC9175 is a halotolerant polycyclic aromatic hydrocarbon (PAH)-degrading bacterium isolated from PAH-contaminated intertidal zone sediment. Here, we report the 5.7-Mb draft genome sequence of this strain, which will provide insights into the diversity of Pannonibacter and the mechanism of PAH degradation in sediments. PMID:26823598

  11. Draft Genome Sequence of Pannonibacter phragmitetus Strain CGMCC9175, a Halotolerant Polycyclic Aromatic Hydrocarbon-Degrading Bacterium.

    PubMed

    Wang, Xinxin; Jin, Decai; Zhou, Lisha; Zhang, Zhuo

    2016-01-01

    Pannonibacter phragmitetus CGMCC9175 is a halotolerant polycyclic aromatic hydrocarbon (PAH)-degrading bacterium isolated from PAH-contaminated intertidal zone sediment. Here, we report the 5.7-Mb draft genome sequence of this strain, which will provide insights into the diversity of Pannonibacter and the mechanism of PAH degradation in sediments. PMID:26823598

  12. Potential probiotic attributes of a new strain of Bacillus coagulans CGMCC 9951 isolated from healthy piglet feces.

    PubMed

    Gu, Shao-Bin; Zhao, Li-Na; Wu, Ying; Li, Shi-Chang; Sun, Jian-Rui; Huang, Jing-Fang; Li, Dan-Dan

    2015-06-01

    A new strain of Bacillus coagulans CGMCC 9551, which has a broad range of antibacterial activities against six main pathogenic bacteria including Escherichia coli O8, Staphylococcus aureus, Salmonella enterica subsp. enterica serovar enteritidis, Streptococcus suis, Listeria monocytogenes and Pasteurella multocida, was isolated from healthy piglet feces. In adhesion assay, the isolate exhibited a stronger adhesion to pig intestinal mucus than that of B. subtilis JT143 and L. acidophilus LY24 respectively isolated from BioPlus()2B and FloraFIT() Probiotics (P < 0.05). The adhesion activity reached 44.5 3.2, 48.9 2.6, 42.6 3.3 and 37.6 2.4% to jejunum, ileum, transverse colon and sigmoid colon, separately. The survival rate of B. coagulans CGMCC 9551 was reduced by only 20% at 4 h exposure under 0.9% w/v bile salt. The strain was fully resistant to pH 2 for 2 h with 90.1 3.5% survival and susceptible to 15 antibiotics commonly used in veterinary medicine. Additionally, the bacteria showed amylase, protease and cellulase activities. The safety assessment demonstrated the lack of toxicity potential in B. coagulans CGMCC 9551 by ligated rabbit ileal loop assay, acute and subchronic toxicity test. These results implied that that the new strain of B. coagulans CGMCC 9951 isolated from healthy piglet feces has promising probiotic characteristics and offers desirable opportunities for its successful commercialization as one excellent candidate probiotic. PMID:25752235

  13. Potential probiotic attributes of a new strain of Bacillus coagulans CGMCC 9951 isolated from healthy piglet feces.

    TOXLINE Toxicology Bibliographic Information

    Gu SB; Zhao LN; Wu Y; Li SC; Sun JR; Huang JF; Li DD

    2015-06-01

    A new strain of Bacillus coagulans CGMCC 9551, which has a broad range of antibacterial activities against six main pathogenic bacteria including Escherichia coli O8, Staphylococcus aureus, Salmonella enterica subsp. enterica serovar enteritidis, Streptococcus suis, Listeria monocytogenes and Pasteurella multocida, was isolated from healthy piglet feces. In adhesion assay, the isolate exhibited a stronger adhesion to pig intestinal mucus than that of B. subtilis JT143 and L. acidophilus LY24 respectively isolated from BioPlus()2B and FloraFIT() Probiotics (P < 0.05). The adhesion activity reached 44.5 3.2, 48.9 2.6, 42.6 3.3 and 37.6 2.4% to jejunum, ileum, transverse colon and sigmoid colon, separately. The survival rate of B. coagulans CGMCC 9551 was reduced by only 20% at 4 h exposure under 0.9% w/v bile salt. The strain was fully resistant to pH 2 for 2 h with 90.1 3.5% survival and susceptible to 15 antibiotics commonly used in veterinary medicine. Additionally, the bacteria showed amylase, protease and cellulase activities. The safety assessment demonstrated the lack of toxicity potential in B. coagulans CGMCC 9551 by ligated rabbit ileal loop assay, acute and subchronic toxicity test. These results implied that that the new strain of B. coagulans CGMCC 9951 isolated from healthy piglet feces has promising probiotic characteristics and offers desirable opportunities for its successful commercialization as one excellent candidate probiotic.

  14. Discovery of pentangular polyphenols hexaricins A-C from marine Streptosporangium sp. CGMCC 4.7309 by genome mining.

    PubMed

    Tian, Jun; Chen, Haiyan; Guo, Zhengyan; Liu, Ning; Li, Jine; Huang, Ying; Xiang, Wensheng; Chen, Yihua

    2016-05-01

    Many novel microbial nature products were discovered from Actinobacteria by genome mining methods. However, only a few number of genome mining works were carried out in rare actinomycetes. An important reason precluding the genome mining efforts in rare actinomycetes is that most of them are recalcitrant to genetic manipulation. Herein, we chose the rare marine actinomycete Streptosporangium sp. CGMCC 4.7309 to explore its secondary metabolite diversity by genome mining. The genetic manipulation method has never been established for Streptosporangium strains. At first, we set up the genetic system of Streptosporangium sp. CGMCC 4.7309 unprecedentedly. The draft genome sequencing of Streptosporangium sp. CGMCC 4.7309 revealed that it contains more than 20 cryptic secondary metabolite biosynthetic clusters. A type II polyketide synthases-containing cluster (the hex cluster) was predicted to encode compounds with a pentangular polyphenol scaffold by in silico analysis. The products of the hex cluster were uncovered by comparing the metabolic profile of Streptosporangium sp. CGMCC 4.7309 with that of the hex30 inactivated mutant, in which a key ketoreductase gene was disrupted. Finally, three pentangular polyphenols were isolated and named as hexaricins A (1), B (2), and C (3). The inconsistency of the stereochemistry of C-15 in hexaricins A, B, and C indicates a branch point in their biosynthesis. Finally, the biosynthetic pathway of the hexaricins was proposed based on bioinformatics analysis. PMID:26754814

  15. Specific gonadotropin binding to Pseudomonas maltophilia.

    PubMed

    Richert, N D; Ryan, R J

    1977-03-01

    Binding of 125I-labeled human chorionic gonadotropin to Pseudomonas maltophilia is dependent on time, temperature, and pH and the binding to this procaryotic species is hormone-specific and saturable. The equilibrium dissociation constant is 2.3 X 10(-9) M. There are no cooperative interactions between binding sites (Hill coefficient, 1.05). The number of sites is estimaated as 240 fmol/100 mug of protein. NaCl and KCl, at concentrations from 1 to 10 mM, have no effect on binding. Divalent cations (Mg2+ and Ca2+) and 1 mM EDTA inhibit hormone binding. Binding is destroyed by heat or by treatment with Pronase of alpha-chymotrypsin and is increased by phospholipase C. Binding of the labeled gonadotropin is not observed with other gram-negative organisms--e.g., Escherichia coli, Pseudomonas testosteroni, Pseudomonas aeruginosa, Enterobacter aerogenes, or Enterobacter cloacae. PMID:265583

  16. Efficient Production of Lactic Acid from Sweet Sorghum Juice by a Newly Isolated Lactobacillus salivarius CGMCC 7.75.

    PubMed

    Liu, Quanlan; Wang, Shanglong; Zhi, Jian-Fei; Ming, Henglei; Teng, Dawei

    2013-09-01

    Sweet sorghum juice was a cheap and renewable resource, and also a potential carbon source for the fermentation production of lactic acid (LA) by a lactic acid bacterium. One newly isolated strain Lactobacillus salivarius CGMCC 7.75 showed the ability to produce the highest yield and optical purity of LA from sweet sorghum juice. Studies of feeding different concentrations of sweet sorghum juice and nitrogen source suggested the optimal concentrations of fermentation were 325 ml l(-1) and 20 g l(-1), respectively. This combination produced 142.49 g l(-1) LA with a productivity level of 0.90 g of LA per gram of sugars consumed. The results indicated the high LA concentration achieved using L. salivarius CGMCC 7.75 not only gives cheap industrial product, but also broaden the application of sweet sorghum. PMID:24426133

  17. Genome Sequence of Bacillus licheniformis CGMCC3963, a Stress-Resistant Strain Isolated in a Chinese Traditional Solid-State Liquor-Making Process

    PubMed Central

    Wu, Qun; Peng, Suqin; Yu, Yao; Li, Yixue

    2013-01-01

    Bacillus licheniformis CGMCC3963 is an important mao-tai flavor-producing strain. It was isolated from the starter (Daqu) of a Chinese mao-tai-flavor liquor fermentation process with solid-state fermentation. We report its genome of 4,525,096bp here. Many potential insertion genes that are responsible for the unique properties of B. licheniformis CGMCC3963 in mao-tai-flavor liquor production were identified. PMID:23405325

  18. Purification and characterisation of a bifunctional alginate lyase from novel Isoptericola halotolerans CGMCC 5336.

    PubMed

    Dou, Wenfang; Wei, Dan; Li, Hui; Li, Heng; Rahman, Muhammad Masfiqur; Shi, Jinsong; Xu, Zhenghong; Ma, Yanhe

    2013-11-01

    A novel halophilic alginate-degrading microorganism was isolated from rotten seaweed and identified as Isoptericola halotolerans CGMCC5336. The lyase from the strain was purified to homogeneity by combining of ammonium sulfate fractionation and anion-exchange chromatography with a specific activity of 8409.19 U/ml and a recovery of 25.07%. This enzyme was a monomer with a molecular mass of approximately 28 kDa. The optimal temperature and pH were 50 °C and pH 7.0, respectively. The lyase maintained stability at neutral pH (7.0-8.0) and temperatures below 50 °C. Metal ions including Na(+), Mg(2+), Mn(2+), and Ca(2+) notably increased the activity of the enzyme. With sodium alginate as the substrate, the Km and Vmax were 0.26 mg/ml and 1.31 mg/ml min, respectively. The alginate lyase had substrate specificity for polyguluronate and polymannuronate units in alginate molecules, indicating its bifunctionality. These excellent characteristics demonstrated the potential applications in alginate oligosaccharides production with low polymerisation degrees. PMID:24053829

  19. Statistical experimental design optimization of rhamsan gum production by Sphingomonas sp. CGMCC 6833.

    PubMed

    Xu, Xiao-Ying; Dong, Shu-Hao; Li, Sha; Chen, Xiao-Ye; Wu, Ding; Xu, Hong

    2015-04-01

    Rhamsan gum is a type of water-soluble exopolysaccharide produced by species of Sphingomonas bacteria. The optimal fermentation medium for rhamsan gum production by Sphingomonas sp. CGMCC 6833 was explored definition. Single-factor experiments indicate that glucose, soybean meal, K(2)HPO(4) and MnSO(4) compose the optimal medium along with and initial pH 7.5. To discover ideal cultural conditions for rhamsan gum production in a shake flask culture, response surface methodology was employed, from which the following optimal ratio was derived: 5.38 g/L soybean meal, 5.71 g/L K(2)HPO(4) and 0.32 g/L MnSO(4). Under ideal fermentation rhamsan gum yield reached 19.58 g/L ± 1.23 g/L, 42.09% higher than that of the initial medium (13.78 g/L ± 1.38 g/L). Optimizing the fermentation medium results in enhanced rhamsan gum production. PMID:25845540

  20. Long-term preservation of strains of Burkholderia cepacia, Pseudomonas spp. and Stenotrophomonas maltophilia isolated from patients with cystic fibrosis.

    PubMed

    Moore, J E; Shaw, A B; Stanley, T; Crowe, M J; Elborn, J S

    2001-07-01

    Long-term preservation methods are important in the maintenance of bacteria for downstream research applications. Most clinical laboratories have only limited resources for archiving isolates and therefore require cost-effective and simple methods. An effective and cheap storage method using debrinated blood and maintenance at -80 degrees C is described. PMID:11442821

  1. Selective medium for isolation of Xanthomonas maltophilia from soil and rhizosphere environments.

    PubMed Central

    Juhnke, M E; des Jardin, E

    1989-01-01

    A selective medium (XMSM) was developed for isolation of Xanthomonas maltophilia from bulk soil and plant rhizosphere environments. The XMSM basal medium contained maltose, tryptone, bromthymol blue, and agar. Antibiotics added to select for X. maltophilia were cycloheximide, nystatin, cephalexin, bacitracin, penicillin G, novobiocin, neomycin sulfate, and tobramycin. A comparison was made between XMSM and 1/10-strength tryptic soy broth agar for recovery of X. maltophilia from sterile and nonsterile soil infested with known X. maltophilia isolates. A recovery rate of 97% or greater for XMSM was demonstrated. XMSM was used to isolate X. maltophilia from a variety of soil and rhizosphere environments. PMID:2930173

  2. Clostridium Butyricum CGMCC0313.1 Modulates Lipid Profile, Insulin Resistance and Colon Homeostasis in Obese Mice.

    PubMed

    Shang, Haixiao; Sun, Jia; Chen, Yong Q

    2016-01-01

    Obesity is associated with a cluster of metabolic disorders and systemic low-grade inflammation involving multiple organs. Recent findings have suggested that intestine is a key organ altered in response to high fat diet (HFD) feeding. Probiotics mainly lactobacillus strains have earlier been implicated in alleviating metabolic disorders. Here we aimed to examine the effects of a naturally occurring butyrate-producing probiotic clostridium butyricum CGMCC0313.1 (CB0313.1) in limiting the development of HFD-induced obesity. Mice treated with CB0313.1 exhibited reduced lipid accumulation in liver and serum, lower circulating insulin levels and improved glucose tolerance and insulin sensitivity. Furthermore, CB0313.1 administration reversed the HFD-induced colonic inflammation as evidenced by reduced tumor necrosis factor (TNF)-α level and increases the interleukin (IL)-10 and IL-22 levels in colon tissue. Additionally to colonic inflammation, CB0313.1 also reduced the colon permeability by upregulating the tight junction (TJ) proteins (claudin-1 and occludin) and contributed to a decreased circulating endotoxin level. In colon content, CB0313.1 administration restored the reduced production of butyrate and other short chain fatty acids (SCFAs) caused by HFD feeding. In adipose tissue, lower transcriptional levels of pro-inflammatory TNF-α, IL-6, IL-1β and monocyte chemotactic protein (MCP)-1 in adipose tissue were observed in CB0313.1-treated mice. Collectively, our data demonstrated that CB0313.1, targeting colon inflammation and permeability, ameliorated HFD-induced obesity, insulin resistance as well as adipose inflammation. PMID:27123997

  3. Revealing Differences in Metabolic Flux Distributions between a Mutant Strain and Its Parent Strain Gluconacetobacter xylinus CGMCC 2955

    PubMed Central

    Liu, Miao; Yang, Xiao-Ning; Zhu, Hui-Xia; Jia, Yuan-Yuan; Jia, Shi-Ru; Piergiovanni, Luciano

    2014-01-01

    A better understanding of metabolic fluxes is important for manipulating microbial metabolism toward desired end products, or away from undesirable by-products. A mutant strain, Gluconacetobacter xylinus AX2-16, was obtained by combined chemical mutation of the parent strain (G. xylinus CGMCC 2955) using DEC (diethyl sulfate) and LiCl. The highest bacterial cellulose production for this mutant was obtained at about 11.75 g/L, which was an increase of 62% compared with that by the parent strain. In contrast, gluconic acid (the main byproduct) concentration was only 5.71 g/L for mutant strain, which was 55.7% lower than that of parent strain. Metabolic flux analysis indicated that 40.1% of the carbon source was transformed to bacterial cellulose in mutant strain, compared with 24.2% for parent strain. Only 32.7% and 4.0% of the carbon source were converted into gluconic acid and acetic acid in mutant strain, compared with 58.5% and 9.5% of that in parent strain. In addition, a higher flux of tricarboxylic acid (TCA) cycle was obtained in mutant strain (57.0%) compared with parent strain (17.0%). It was also indicated from the flux analysis that more ATP was produced in mutant strain from pentose phosphate pathway (PPP) and TCA cycle. The enzymatic activity of succinate dehydrogenase (SDH), which is one of the key enzymes in TCA cycle, was 1.65-fold higher in mutant strain than that in parent strain at the end of culture. It was further validated by the measurement of ATPase that 3.53–6.41 fold higher enzymatic activity was obtained from mutant strain compared with parent strain. PMID:24901455

  4. Clostridium Butyricum CGMCC0313.1 Modulates Lipid Profile, Insulin Resistance and Colon Homeostasis in Obese Mice

    PubMed Central

    Shang, Haixiao

    2016-01-01

    Obesity is associated with a cluster of metabolic disorders and systemic low-grade inflammation involving multiple organs. Recent findings have suggested that intestine is a key organ altered in response to high fat diet (HFD) feeding. Probiotics mainly lactobacillus strains have earlier been implicated in alleviating metabolic disorders. Here we aimed to examine the effects of a naturally occurring butyrate-producing probiotic clostridium butyricum CGMCC0313.1 (CB0313.1) in limiting the development of HFD-induced obesity. Mice treated with CB0313.1 exhibited reduced lipid accumulation in liver and serum, lower circulating insulin levels and improved glucose tolerance and insulin sensitivity. Furthermore, CB0313.1 administration reversed the HFD-induced colonic inflammation as evidenced by reduced tumor necrosis factor (TNF)-α level and increases the interleukin (IL)-10 and IL-22 levels in colon tissue. Additionally to colonic inflammation, CB0313.1 also reduced the colon permeability by upregulating the tight junction (TJ) proteins (claudin-1 and occludin) and contributed to a decreased circulating endotoxin level. In colon content, CB0313.1 administration restored the reduced production of butyrate and other short chain fatty acids (SCFAs) caused by HFD feeding. In adipose tissue, lower transcriptional levels of pro-inflammatory TNF-α, IL-6, IL-1β and monocyte chemotactic protein (MCP)-1 in adipose tissue were observed in CB0313.1-treated mice. Collectively, our data demonstrated that CB0313.1, targeting colon inflammation and permeability, ameliorated HFD-induced obesity, insulin resistance as well as adipose inflammation. PMID:27123997

  5. Cloning, purification, crystallization and preliminary X-ray diffraction of the OleC protein from Stenotrophomonas maltophilia involved in head-to-head hydrocarbon biosynthesis

    SciTech Connect

    Frias, JA; Goblirsch, BR; Wackett, LP; Wilmot, CM

    2010-08-28

    OleC, a biosynthetic enzyme involved in microbial hydrocarbon biosynthesis, has been crystallized. Synchrotron X-ray diffraction data have been collected to 3.4 A resolution. The crystals belonged to space group P3(1)21 or P3(2)21, with unit-cell parameters a = b = 98.8, c = 141.0 A.

  6. Degradation Potential of Protocatechuate 3,4-Dioxygenase from Crude Extract of Stenotrophomonas maltophilia Strain KB2 Immobilized in Calcium Alginate Hydrogels and on Glyoxyl Agarose

    PubMed Central

    Krysiak, Marta

    2014-01-01

    Microbial intradiol dioxygenases have been shown to have a great potential for bioremediation; however, their structure is sensitive to various environmental and chemical agents. Immobilization techniques allow for the improvement of enzyme properties. This is the first report on use of glyoxyl agarose and calcium alginate as matrixes for the immobilization of protocatechuate 3,4-dioxygenase. Multipoint attachment of the enzyme to the carrier caused maintenance of its initial activity during the 21 days. Immobilization of dioxygenase in calcium alginate or on glyoxyl agarose resulted in decrease in the optimum temperature by 5°C and 10°C, respectively. Entrapment of the enzyme in alginate gel shifted its optimum pH towards high-alkaline pH while immobilization of the enzyme on glyoxyl agarose did not influence pH profile of the enzyme. Protocatechuate 3,4-dioygenase immobilized in calcium alginate showed increased activity towards 2,5-dihydroxybenzoate, caffeic acid, 2,3-dihydroxybenzoate, and 3,5-dihydroxybenzoate. Slightly lower activity of the enzyme was observed after its immobilization on glyoxyl agarose. Entrapment of the enzyme in alginate gel protected it against chelators and aliphatic alcohols while its immobilization on glyoxyl agarose enhanced enzyme resistance to inactivation by metal ions. PMID:24693536

  7. Identification of a Novel Dye-Decolorizing Peroxidase, EfeB, Translocated by a Twin-Arginine Translocation System in Streptococcus thermophilus CGMCC 7.179

    PubMed Central

    Zhang, Chenchen; Xin, Yongping; Wang, Yue; Guo, Tingting; Lu, Shiyi

    2015-01-01

    Streptococcus thermophilus is a facultative anaerobic bacterium that has the ability to grow and survive in aerobic environments, but the mechanism for this remains unclear. In this study, the efeB gene, encoding a dye-decolorizing peroxidase, was identified in the genome of Streptococcus thermophilus CGMCC 7.179, and purified EfeB was able to decolorize reactive blue 5. Strikingly, genes encoding two components (TatA and TatC) of the twin-arginine translocation (TAT) system were also found in the same operon with the efeB gene. Knocking out efeB or tatC resulted in decreased growth of the strain under aerobic conditions, and complementation of the efeB-deficient strains with the efeB gene enhanced the biomass of the hosts only in the presence of the tatC gene. Moreover, it was proved for both S. thermophilus CGMCC 7.179 and Escherichia coli DE3 that EfeB could be translocated by the TAT system of S. thermophilus. In addition, the transcriptional levels of efeB and tatC increased when the strain was cultured under aerobic conditions. Overall, these results provide the first evidence that EfeB plays a role in protecting cells of S. thermophilus from oxidative stress, with the assistance of the TAT system. PMID:26092460

  8. Poly-γ-glutamic acid produced from Bacillus licheniformis CGMCC 2876 as a potential substitute for polyacrylamide in the sugarcane industry.

    PubMed

    Yan, Shan; Yao, Haosheng; Chen, Zhen; Zeng, Shengquan; Xi, Xi; Wang, Yuanpeng; He, Ning; Li, Qingbiao

    2015-01-01

    As an environmentally friendly and industrially useful biopolymer, poly-γ-glutamic acid (γ-PGA) from Bacillus licheniformis CGMCC 2876 was characterized by the high-resolution mass spectrometry and (1)H NMR. A flocculating activity of 11,474.47 U mL(-1) obtained with γ-PGA, and the effects of carbon sources, ions, and chemical properties (D-/L-composition and molecular weight) on the production and flocculating activity of γ-PGA were discussed. Being a bioflocculant in the sugar refinery process, the color and turbidity of the sugarcane juice was IU 1,877.36 and IU 341.41 with 0.8 ppm of γ-PGA, respectively, which was as good as the most widely used chemically synthesized flocculant in the sugarcane industry--polyacrylamide with 1 ppm. The γ-PGA produced from B. licheniformis CGMCC 2876 could be a promising alternate of chemically synthesized flocculants in the sugarcane industry. PMID:26033934

  9. High efficiency transformation of stevioside into a single mono-glycosylated product using a cyclodextrin glucanotransferase from Paenibacillus sp. CGMCC 5316.

    PubMed

    Yu, Xuejian; Yang, Jinshui; Li, Baozhen; Yuan, Hongli

    2015-12-01

    Stevioside is a non-caloric, natural, high-intensity sweetener. However, the bitter aftertaste of stevioside restricts its utilization for human consumption and limits its application in the food industry. In this study, a high efficiency enzymatic modification system was investigated to improve stevioside taste quality. A cyclodextrin glucanotransferase (CGTase) producing strain Paenibacillus sp. CGMCC 5316 was isolated from Stevia planting soil. With starch as glycosyl donor, this CGTase can transform stevioside into a single specific product which is an isomer of rebaudioside A and identified as mono-glycosylated stevioside. The taste of stevioside is improved noticeably by generating mono-glycosylated stevioside, which possesses a sucrose-like taste and has sweetness increased significantly by 35.4%. Next, the parameters influencing CGTase production were optimized. Compared to initial conditions, CGTase activity increased by 214.7% under optimum conditions of 3.9 g/L starch, 17.9 g/L tryptone, and 67.6 h of culture time, and the transglycosylation rate of stevioside was remarkably increased by 284.8%, reaching 85.6%. This CGTase modification system provides a promising solution for improving the sweetness and taste quality of stevioside. The efficiency of CGTase transformation can be greatly increased by optimizing the culture conditions of Paenibacillus sp. CGMCC 5316. PMID:26395638

  10. Rapid biodegradation of organophosphorus pesticides by Stenotrophomonas sp. G1.

    PubMed

    Deng, Shuyan; Chen, Yao; Wang, Daosheng; Shi, Taozhong; Wu, Xiangwei; Ma, Xin; Li, Xiangqiong; Hua, Rimao; Tang, Xinyun; Li, Qing X

    2015-10-30

    Organophosphorus insecticides have been widely used, which are highly poisonous and cause serious concerns over food safety and environmental pollution. A bacterial strain being capable of degrading O,O-dialkyl phosphorothioate and O,O-dialkyl phosphate insecticides, designated as G1, was isolated from sludge collected at the drain outlet of a chlorpyrifos manufacture plant. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis suggested that strain G1 belongs to the genus Stenotrophomonas. At an initial concentration of 50 mg/L, strain G1 degraded 100% of methyl parathion, methyl paraoxon, diazinon, and phoxim, 95% of parathion, 63% of chlorpyrifos, 38% of profenofos, and 34% of triazophos in 24 h. Orthogonal experiments showed that the optimum conditions were an inoculum volume of 20% (v/v), a substrate concentration of 50 mg/L, and an incubation temperature in 40 °C. p-Nitrophenol was detected as the metabolite of methyl parathion, for which intracellular methyl parathion hydrolase was responsible. Strain G1 can efficiently degrade eight organophosphorus pesticides (OPs) and is a very excellent candidate for applications in OP pollution remediation. PMID:25938642

  11. C-S targeted biodegradation of dibenzothiophene by Stenotrophomonas sp. NISOC-04.

    PubMed

    Papizadeh, Moslem; Ardakani, Mohammad Roayaei; Motamedi, Hossein; Rasouli, Iraj; Zarei, Mohammad

    2011-10-01

    Crude oil-contaminated soil samples were gathered across Khuzestan oilfields (National Iranian South Oil Company, NISOC) consequently experienced a screening procedure for isolating C-S targeted dibenzothiophene-biodegrading microorganisms with previously optimized techniques. Among the isolates, a bacterial strain was selected due to its capability of biodegrading dibenzothiophene in a C-S targeted manner in aqueous phases and medium mostly consisting of separately biphasic water-gasoline. The 16S rDNA of the isolate was amplified using eubacterial-specific primers and then sequenced. Based on sequence data analysis, the microorganism, designated NISOC-04, clustered most closely with the members of the genus Stenotrophomonas. Gas chromatography indicated that Stenotrophomonas sp. NISOC-04 utilizes 82% of starting 0.8 mM dibenzothiophene within a 48-h-long exponential growth phase. Growth curve analysis revealed the inability of Stenotrophomonas sp. NISOC-04 to utilize dibenzothiophene (DBT) as the exclusive carbon or carbon/sulfur source. Gibbs' assay showed no 2-hydroxy biphenyl accumulation, but HPLC confirmed the presence of 2-hydroxy biphenyl as the final product of DBT desulfurization. Under sulfur starvation, Stenotrophomonas sp. NISOC-04 produced a huge biomass with untraceable sulfur and utilized atmospheric insignificant sulfur levels. PMID:21750993

  12. Indirect Manganese Removal by Stenotrophomonas sp. and Lysinibacillus sp. Isolated from Brazilian Mine Water.

    PubMed

    Barboza, Natália Rocha; Amorim, Soraya Sander; Santos, Pricila Almeida; Reis, Flávia Donária; Cordeiro, Mônica Mendes; Guerra-Sá, Renata; Leão, Versiane Albis

    2015-01-01

    Manganese is a contaminant in the wastewaters produced by Brazilian mining operations, and the removal of the metal is notoriously difficult because of the high stability of the Mn(II) ion in aqueous solutions. To explore a biological approach for removing excessive amounts of aqueous Mn(II), we investigated the potential of Mn(II) oxidation by both consortium and bacterial isolates from a Brazilian manganese mine. A bacterial consortium was able to remove 99.7% of the Mn(II). A phylogenetic analysis of isolates demonstrated that the predominant microorganisms were members of Stenotrophomonas, Bacillus, and Lysinibacillus genera. Mn(II) removal rates between 58.5% and 70.9% were observed for Bacillus sp. and Stenotrophomonas sp. while the Lysinibacillus isolate 13P removes 82.7%. The catalytic oxidation of Mn(II) mediated by multicopper oxidase was not properly detected; however, in all of the experiments, a significant increase in the pH of the culture medium was detected. No aggregates inside the cells grown for a week were found by electronic microscopy. Nevertheless, an energy-dispersive X-ray spectroscopy of the isolates revealed the presence of manganese in Stenotrophomonas sp. and Lysinibacillus sp. grown in K medium. These results suggest that members of Stenotrophomonas and Lysinibacillus genera were able to remove Mn(II) by a nonenzymatic pathway. PMID:26697496

  13. Indirect Manganese Removal by Stenotrophomonas sp. and Lysinibacillus sp. Isolated from Brazilian Mine Water

    PubMed Central

    Barboza, Natália Rocha; Amorim, Soraya Sander; Santos, Pricila Almeida; Reis, Flávia Donária; Cordeiro, Mônica Mendes; Guerra-Sá, Renata; Leão, Versiane Albis

    2015-01-01

    Manganese is a contaminant in the wastewaters produced by Brazilian mining operations, and the removal of the metal is notoriously difficult because of the high stability of the Mn(II) ion in aqueous solutions. To explore a biological approach for removing excessive amounts of aqueous Mn(II), we investigated the potential of Mn(II) oxidation by both consortium and bacterial isolates from a Brazilian manganese mine. A bacterial consortium was able to remove 99.7% of the Mn(II). A phylogenetic analysis of isolates demonstrated that the predominant microorganisms were members of Stenotrophomonas, Bacillus, and Lysinibacillus genera. Mn(II) removal rates between 58.5% and 70.9% were observed for Bacillus sp. and Stenotrophomonas sp. while the Lysinibacillus isolate 13P removes 82.7%. The catalytic oxidation of Mn(II) mediated by multicopper oxidase was not properly detected; however, in all of the experiments, a significant increase in the pH of the culture medium was detected. No aggregates inside the cells grown for a week were found by electronic microscopy. Nevertheless, an energy-dispersive X-ray spectroscopy of the isolates revealed the presence of manganese in Stenotrophomonas sp. and Lysinibacillus sp. grown in K medium. These results suggest that members of Stenotrophomonas and Lysinibacillus genera were able to remove Mn(II) by a nonenzymatic pathway. PMID:26697496

  14. Improvement of poly(gamma-glutamic acid) biosynthesis and redistribution of metabolic flux with the presence of different additives in Bacillus subtilis CGMCC 0833.

    PubMed

    Wu, Qun; Xu, Hong; Shi, Ningning; Yao, Jun; Li, Sha; Ouyang, Pingkai

    2008-06-01

    Tween-80, dimethyl sulfoxide (DMSO), and glycerol could be used as novel materials to regulate the central carbon metabolic pathway and improve gamma-PGA biosynthesis by Bacillus subtilis CGMCC 0833. With glycerol in the medium, the activity of 2-oxoglutarate dehydrogenase complex at the key node of 2-oxoglutarate was depressed, more carbon flux distribution was directed to synthesize glutamate, the substrate of gamma-PGA, which led to overproducing of gamma-PGA, reached 31.7 g/l, compared to the original value of 26.7 g/l. When Tween-80 or DMSO was in the medium, the activity of isocitrate dehydrogenase was stimulated, the branch flux from 2-oxoglutarate to glutamate was also enhanced due to the increasing of total flux from iso-citrate to 2-oxoglutarate, then a large amount of glutamate was produced, and formation of gamma-PGA was also improved, which was a different process compared with that of glycerol. Moreover, with the addition of Tween-80 or DMSO, cell membrane permeability was increased, which facilitated the uptake of extracellular substrates and the secretion of gamma-PGA by this strain; therefore, gamma-PGA production was further stimulated, and 34.4 and 32.7 g/l gamma-PGA were obtained, respectively. This work firstly employed additives to improve the biosynthesis of gamma-PGA and would be helpful in understanding the biosynthesis mechanism of gamma-PGA by Bacillus species deeply. PMID:18443783

  15. Bioremediation of hexavalent chromate using permeabilized Brevibacterium sp. and Stenotrophomonas sp. cells.

    PubMed

    Ge, Shimei; Ge, Shichao; Zhou, Maohong; Dong, Xinjiao

    2015-07-01

    Bioremediation has been found to be a useful method for removing hexavalent chromium (Cr(VI)), which is very toxic, from wastewater. Two strains of bacteria that were able to reduce Cr(VI) effectively were isolated from Cr(VI) contaminated soil samples and identified as Brevibacterium sp. K1 and Stenotrophomonas sp. D6, respectively, based on 16S rRNA gene sequence analyses. Brevibacterium sp. K1 and Stenotrophomonas sp. D6 could grow in Luria-Broth medium containing K2Cr2O7 at 1000 and 1600 mg/L, respectively, and they completely reduced the Cr(VI) in LB medium containing K2Cr2O7 at 200 mg/L within 72 h. Further analyses revealed that permeabilized K1 and D6 cells reduced Cr(VI) more effectively than did the resting cells. Triton X-100 was the best permeabilizing agent that was tested. The permeabilized cells of both strains could completely reduce Cr(VI) in industrial wastewater twice before needing to be replenished. The results suggested that these chromate-reducing bacteria are potential candidates for practical use biotreating industrial effluents containing Cr(VI) with Stenotrophomonas sp. D6 being the more effective bacterium. PMID:25881152

  16. Characterization of an alkaline β-agarase from Stenotrophomonas sp. NTa and the enzymatic hydrolysates.

    PubMed

    Zhu, Yanbing; Zhao, Rui; Xiao, Anfeng; Li, Lijun; Jiang, Zedong; Chen, Feng; Ni, Hui

    2016-05-01

    An extracellular agarase from marine bacterium Stenotrophomonas sp. NTa was purified to homogeneity. By size exclusion chromatography and SDS-PAGE analysis, the enzyme was determined to be a homodimer with monomeric molecular mass of 89.0kDa. The optimal temperature and pH of strain NTa agarase were 40°C and 10.0, respectively. It exhibited striking stability across a wide pH range of 5.0-11.0. Agarase from Stenotrophomonas sp. NTa had a relatively good resistance against the detected inhibitors, detergents and urea denaturant. The Km and Vmax for agar were 11.3mg/ml and 25.4U/mg, respectively. Thin layer chromatography analysis, mass spectrometry, and enzyme assay using p-nitrophenyl-α/β-d-galactopyranoside revealed that strain NTa agarase was a β-agarase that degraded agarose into neoagarobiose, neoagarotetraose and neoagarohexaose as the predominant products, as well as a small amount of 3,6-anhydro-α-l-galactose. This is the first to present evidence of agarolytic activity in strain from genus Stenotrophomonas. PMID:26836616

  17. Genetic engineering to contain the Vitreoscilla hemoglobin gene enhances degradation of benzoic acid by Xanthomonas maltophilia

    SciTech Connect

    Liu, S.C.; Webster, D.A.; Wei, M.L.; Stark, B.C.

    1996-01-05

    Xanthomonas maltophilia was transformed with the gene encoding Vitreoscilla (bacterial) hemoglobin, vgb, and the growth of the engineered strain was compared with that of the untransformed strain using benzoic acid as the sole carbon source. In general, growth of the engineered strain was greater than that of the untransformed strain; this was true for experiments using both overnight cultures and log phase cells as inocula, but particularly for the latter. In both cases the engineered strain was also more efficiency than the untransformed strain in converting benzoic acid into biomass.

  18. 7alpha-OH epimerisation of bile acids via oxido-reduction with Xanthomonas maltophilia.

    PubMed

    Medici, Alessandro; Pedrini, Paola; Bianchini, Ercolina; Fantin, Giancarlo; Guerrini, Alessandra; Natalini, Benedetto; Pellicciari, Roberto

    2002-01-01

    The microbial 7alpha-OH epimerisation of cholic, chenodeoxycholic, and 12-ketochenodeoxycholic acids (7alpha-OH bile acids) with Xanthomonas maltophilia CBS 827.97 to corresponding 7beta-OH derivatives with scarcity of oxygen is described. With normal pressure of oxygen the 7-OH oxidation products are obtained. No biotransformations are achieved in anaerobic conditions. The microbial 7alpha-OH epimerisation is achieved by oxidation of 7-OH function and subsequent reduction. Partial purification, in fact, of the enzymatic fraction revealed the presence of two hydroxysteroid dehydrogenases (HSDH) alpha- and beta-stereospecific together with a glycocholate hydrolase. On the basis of these results a further application is the microbial reduction of 6alpha-fluoro and 6beta-fluoro-3alpha-hydroxy-7-oxo-5beta-cholan-24-oic acid methyl esters to the corresponding 7alpha-OH and 7beta-OH derivatives. PMID:11728521

  19. Kinetic analysis of extension of substrate specificity with Xanthomonas maltophilia, Aeromonas hydrophila, and Bacillus cereus metallo-beta-lactamases.

    PubMed Central

    Felici, A; Amicosante, G

    1995-01-01

    Twenty beta-lactam molecules, including penicillins, cephalosporins, penems, carbapenems, and monobactams, were investigated as potential substrates for Xanthomonas maltophilia ULA-511, Aeromonas hydrophila AE036, and Bacillus cereus 5/B/6 metallo-beta-lactamases. A detailed analysis of the kinetic parameters examined confirmed these enzymes to be broad-spectrum beta-lactamases with different ranges of catalytic efficiency. Cefoxitin and moxalactam, substrates for the beta-lactamases from X. maltophilia ULA-511 and B. cereus 5/B/6, behaved as inactivators of the A. hydrophila AE036 metallo-beta-lactamase, which appeared to be unique among the enzymes tested in this study. In addition, we report a new, faster, and reliable purification procedure for the B. cereus 5/B/6 metallo-beta-lactamase, cloned in Escherichia coli HB101. PMID:7695305

  20. Degradative potential of Stenotrophomonas strain HPC383 having genes homologous to dmp operon.

    PubMed

    Verma, Vinita; Raju, Sajan C; Kapley, Atya; Kalia, Vipin Chandra; Kanade, Gajanan S; Daginawala, Hatim F; Purohit, Hemant J

    2011-02-01

    A strain, Stenotrophomonas HPC383 is isolated from effluent treatment plant treating wastewater from pesticide industry; degrades various aromatic compounds (cresols, phenol, catechol, 4methyl-catechol and hydroquinone) and crude oil, as determined through HPLC and GC analysis. Culture HPC383 could degrade (%) various compounds (1 mM) from a mixture: phenol - 99, p-cresol - 100, 4-methylcatechol - 96 and hydroquinone - 43 within 48 h of incubation, whereas it took 7 days to degrade 94% of 0.5% crude oil. Gene locus dmpN, to identify phenol degrading capacity was determined by PCR followed by southern analysis. The sequenced DNA fragment exhibited 99% sequence similarity to phenol hydroxylase gene from Arthrobacter sp. W1 (FJ610336). Amino acid sequence analysis of phenol hydroxylase reveals it to belong to high-Ks (affinity constant) group. Application of HPC383 in bioremediation of aquatic and terrestrial sites contaminated with petrochemical has been suggested. PMID:21123060

  1. Characterization of three antifungal calcite-forming bacteria, Arthrobacter nicotianae KNUC2100, Bacillus thuringiensis KNUC2103, and Stenotrophomonas maltophilia KNUC2106, derived from the Korean islands, Dokdo and their application on mortar.

    PubMed

    Park, Jong-Myong; Park, Sung-Jin; Ghim, Sa-Youl

    2013-09-28

    Crack remediation on the surface of cement mortar using microbiological calcium carbonate (CaCO3) precipitation (MICP) has been investigated as a microbial sealing agent on construction materials. However, MICP research has never acknowledged the antifungal properties of calcite-forming bacteria (CFB). Since fungal colonization on concrete surfaces can trigger biodeterioration processes, fungi on concrete buildings have to be prevented. Therefore, to develop a microbial sealing agent that has antifungal properties to remediate cement cracks without deteriorative fungal colonization, we introduced an antifungal CFB isolated from oceanic islands (Dokdo islands, territory of South Korea, located at the edge of the East Sea in Korea.). The isolation of CFB was done using B4 or urea-CaCl2 media. Furthermore, antifungal assays were done using the pairing culture and disk diffusion methods. Five isolated CFB showed CaCO3 precipitation and antifungal activities against deteriorative fungal strains. Subsequently, five candidate bacteria were identified using 16S rDNA sequence analysis. Crack remediation, fungi growth inhibition, and water permeability reduction of antifungal CFB-treated cement surfaces were tested. All antifungal CFB showed crack remediation abilities, but only three strains (KNUC2100, 2103, and 2106) reduced the water permeability. Furthermore, these three strains showed fungi growth inhibition. This paper is the first application research of CFB that have antifungal activity, for an eco-friendly improvement of construction materials. PMID:23727794

  2. Biodegradation of DDT by Stenotrophomonas sp. DDT-1: Characterization and genome functional analysis

    NASA Astrophysics Data System (ADS)

    Pan, Xiong; Lin, Dunli; Zheng, Yuan; Zhang, Qian; Yin, Yuanming; Cai, Lin; Fang, Hua; Yu, Yunlong

    2016-02-01

    A novel bacterium capable of utilizing 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) as the sole carbon and energy source was isolated from a contaminated soil which was identified as Stenotrophomonas sp. DDT-1 based on morphological characteristics, BIOLOG GN2 microplate profile, and 16S rDNA phylogeny. Genome sequencing and functional annotation of the isolate DDT-1 showed a 4,514,569 bp genome size, 66.92% GC content, 4,033 protein-coding genes, and 76 RNA genes including 8 rRNA genes. Totally, 2,807 protein-coding genes were assigned to Clusters of Orthologous Groups (COGs), and 1,601 protein-coding genes were mapped to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. The degradation half-lives of DDT increased with substrate concentration from 0.1 to 10.0 mg/l, whereas decreased with temperature from 15 °C to 35 °C. Neutral condition was the most favorable for DDT biodegradation. Based on genome annotation of DDT degradation genes and the metabolites detected by GC-MS, a mineralization pathway was proposed for DDT biodegradation in which it was orderly converted into DDE/DDD, DDMU, DDOH, and DDA via dechlorination, hydroxylation, and carboxylation, and ultimately mineralized to carbon dioxide. The results indicate that the isolate DDT-1 is a promising bacterial resource for the removal or detoxification of DDT residues in the environment.

  3. Biodegradation of toluene and xylenes under microaerophilic and denitrifying conditions by Pseudomonas maltophilia

    SciTech Connect

    Su, J.J.

    1994-01-01

    Aerobic biodegradation of aromatic hydrocarbons has been well studied. Under aerobic conditions, aerobes or facultative anaerobes can utilize aromatic hydrocarbons as sole carbon and energy sources by using oxygen as the cosubstrate of oxygenase enzymes for the initial attack of the aromatic ring and as the terminal electron acceptor for aerobic respiration. However, some facultative or obligate anaerobes can degrade these hydrocarbons by using alternate electron acceptors, such as nitrate, sulfate, carbon dioxide, or iron for anaerobic respiration. Among the potential alternate electron acceptors available, nitrate is the most common one used by microorganisms under oxygen-limited conditions. The first objective of this project was to explore hydrocarbon utilization under anoxic or low oxygen conditions. A microorganism that can utilize the petroleum hydrocarbons, toluene and xylene, as sole carbon and energy sources under microaerophilic (2% oxygen) and denitrifying conditions was isolated and characterized. Since oxygen may repress microbial denitrification, it was of interest to monitor the effects of low oxygen levels on aromatic hydrocarbon biodegradation coupled to denitrification. We isolated a Gram-negative rod, Pseudomonas maltophilia from anaerobic sewage digester sludge. The patterns of biodegradations of toluene and two isomers of xylenes, m- and p-xylene, were very similar under either microaerophilic or anaerobic conditions. Nitrate reduction was also observed during time course experiments under aerobic conditions. The final objective was to test the feasibility of an immobilized cell reactor to treat waste streams. Therefore, a bench-scale bioreactor was built to treat a waste stream contaminated with both toluene and nitrate without aeration. The utilization of toluene and nitrate was monitored periodically in a continuous system under anaerobic conditions.

  4. Oral supplementation with Lactobacillus rhamnosus CGMCC 1.3724 prevents development of atopic dermatitis in NC/NgaTnd mice possibly by modulating local production of IFN-gamma.

    PubMed

    Tanaka, Akane; Jung, Kyungsook; Benyacoub, Jalil; Prioult, Guenole; Okamoto, Noriko; Ohmori, Keitaro; Blum, Stephanie; Mercenier, Annick; Matsuda, Hiroshi

    2009-12-01

    Prevalence of allergies has increased during the last two decades. Alteration of the gut microbiota composition is thought to play a crucial role in development of atopic diseases. Oral administration of probiotics has been reported to treat and/or prevent symptoms of atopic diseases in infants, but the results are still controversial. We investigated the potential efficacy of dietary interventions by a probiotic strain on prevention and treatment of atopic dermatitis (AD) in a human-like AD model, NC/NgaTnd mice by perinatal administration. Pregnant NC/NgaTnd mice were orally treated with the probiotic strain Lactobacillus rhamnosus CGMCC 1.3724 (LPR), which was followed by treatment of pups until 12 weeks of age. LPR-treated mice exhibited significant lower clinical symptoms of dermatitis, reduced scratching frequency, lower levels of plasma total Immunoglobulin E and higher levels of interferon-gamma in skin biopsies, compared with untreated mice. The protective effect was also observed when mice started to be treated at weaning time (5 weeks of age) even with limited supplementation period of 2 weeks. However, treatment of mice with the probiotic starting 1 week after the onset of the disease (8 weeks of age) had limited effects. The usefulness of LPR for primary prevention of AD was supported. PMID:19555432

  5. Root-microbe systems: the effect and mode of interaction of Stress Protecting Agent (SPA) Stenotrophomonas rhizophila DSM14405T

    PubMed Central

    Alavi, Peyman; Starcher, Margaret R.; Zachow, Christin; Müller, Henry; Berg, Gabriele

    2013-01-01

    Stenotrophomonas rhizophila has great potential for applications in biotechnology and biological control due to its ability to both promote plant growth and protect roots against biotic and a-biotic stresses, yet little is known about the mode of interactions in the root-environment system. We studied mechanisms associated with osmotic stress using transcriptomic and microscopic approaches. In response to salt or root extracts, the transcriptome of S. rhizophila DSM14405T changed drastically. We found a notably similar response for several functional gene groups responsible for general stress protection, energy production, and cell motility. However, unique changes in the transcriptome were also observed: the negative regulation of flagella-coding genes together with the up-regulation of the genes responsible for biofilm formation and alginate biosynthesis were identified as a single mechanism of S. rhizophila DSM14405T against salt shock. However, production and excretion of glucosylglycerol (GG) were found as a remarkable mechanism for the stress protection of this Stenotrophomonas strain. For S. rhizophila treated with root exudates, the shift from the planktonic lifestyle to a sessile one was measured as expressed in the down-regulation of flagellar-driven motility. These findings fit well with the observed positive regulation of host colonization genes and microscopic images that show different colonization patterns of oilseed rape roots. Spermidine, described as a plant growth regulator, was also newly identified as a protector against stress. Overall, we identified mechanisms of Stenotrophomonas to protect roots against osmotic stress in the environment. In addition to both the changes in life style and energy metabolism, phytohormons, and osmoprotectants were also found to play a key role in stress protection. PMID:23717321

  6. Microcystin-degrading activity of an indigenous bacterial strain Stenotrophomonas acidaminiphila MC-LTH2 isolated from Lake Taihu.

    PubMed

    Yang, Fei; Zhou, Yuanlong; Yin, Lihong; Zhu, Guangcan; Liang, Geyu; Pu, Yuepu

    2014-01-01

    Microcystin-LR (MC-LR) and microcystin-RR (MC-RR) produced by harmful cyanobacterial blooms (HCBs) pose substantial threats to the ecosystem and public health due to their potential hepatotoxicity. Degradation of microcystins (MCs) by indigenous bacteria represents a promising method for removing MCs from fresh water without harming the aquatic environment, but only a few microcystin (MC)-degrading bacteria have been isolated and had their mechanisms reported. This study aimed to isolate indigenous bacteria from Lake Taihu, and investigate the capability and mechanism of MC degradation by these bacteria. During a Microcystis bloom, an indigenous MC-degrading bacterium designated MC-LTH2 was successfully isolated from Lake Taihu, and identified as Stenotrophomonas acidaminiphila based on phylogenetic analysis. In the presence of MC-LR together with MC-RR, the strain MC-LTH2 was capable of totally degrading both simultaneously in 8 days, at rates of 3.0 mg/(L?d) and 5.6 mg/(L?d), respectively. The degradation rates of MCs were dependent on temperature, pH, and initial MC concentration. Adda (3-amino-9-methoxy-2, 6, 8-trimethyl-10-phenyldeca-4, 6-dienoic acid) was detected as an intermediate degradation product of MCs using high performance liquid chromatography coupled with time-of-flight mass spectrometry (HPLC-TOF-MS). To the best of our knowledge, this is the first report of Stenotrophomonas acidaminiphila capable of degrading two MC analogues and other compounds containing Adda residue completely under various conditions, although the mlrA gene in the strain was not detected. These results indicate the Stenotrophomonas acidaminiphila strain MC-LTH2 possesses a significant potential to be used in bioremediation of water bodies contaminated by MC-LR and MC-RR, and is potentially involved in the degradation of MCs during the disappearance of the HCBs in Lake Taihu. PMID:24416455

  7. Microcystin-Degrading Activity of an Indigenous Bacterial Strain Stenotrophomonas acidaminiphila MC-LTH2 Isolated from Lake Taihu

    PubMed Central

    Yang, Fei; Zhou, Yuanlong; Yin, Lihong; Zhu, Guangcan; Liang, Geyu; Pu, Yuepu

    2014-01-01

    Microcystin-LR (MC-LR) and microcystin-RR (MC-RR) produced by harmful cyanobacterial blooms (HCBs) pose substantial threats to the ecosystem and public health due to their potential hepatotoxicity. Degradation of microcystins (MCs) by indigenous bacteria represents a promising method for removing MCs from fresh water without harming the aquatic environment, but only a few microcystin (MC)-degrading bacteria have been isolated and had their mechanisms reported. This study aimed to isolate indigenous bacteria from Lake Taihu, and investigate the capability and mechanism of MC degradation by these bacteria. During a Microcystis bloom, an indigenous MC-degrading bacterium designated MC-LTH2 was successfully isolated from Lake Taihu, and identified as Stenotrophomonas acidaminiphila based on phylogenetic analysis. In the presence of MC-LR together with MC-RR, the strain MC-LTH2 was capable of totally degrading both simultaneously in 8 days, at rates of 3.0 mg/(L⋅d) and 5.6 mg/(L⋅d), respectively. The degradation rates of MCs were dependent on temperature, pH, and initial MC concentration. Adda (3-amino-9-methoxy-2, 6, 8-trimethyl-10-phenyldeca-4, 6-dienoic acid) was detected as an intermediate degradation product of MCs using high performance liquid chromatography coupled with time-of-flight mass spectrometry (HPLC-TOF-MS). To the best of our knowledge, this is the first report of Stenotrophomonas acidaminiphila capable of degrading two MC analogues and other compounds containing Adda residue completely under various conditions, although the mlrA gene in the strain was not detected. These results indicate the Stenotrophomonas acidaminiphila strain MC-LTH2 possesses a significant potential to be used in bioremediation of water bodies contaminated by MC-LR and MC-RR, and is potentially involved in the degradation of MCs during the disappearance of the HCBs in Lake Taihu. PMID:24416455

  8. Biodegradation of DDT by Stenotrophomonas sp. DDT-1: Characterization and genome functional analysis.

    PubMed

    Pan, Xiong; Lin, Dunli; Zheng, Yuan; Zhang, Qian; Yin, Yuanming; Cai, Lin; Fang, Hua; Yu, Yunlong

    2016-01-01

    A novel bacterium capable of utilizing 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) as the sole carbon and energy source was isolated from a contaminated soil which was identified as Stenotrophomonas sp. DDT-1 based on morphological characteristics, BIOLOG GN2 microplate profile, and 16S rDNA phylogeny. Genome sequencing and functional annotation of the isolate DDT-1 showed a 4,514,569 bp genome size, 66.92% GC content, 4,033 protein-coding genes, and 76 RNA genes including 8 rRNA genes. Totally, 2,807 protein-coding genes were assigned to Clusters of Orthologous Groups (COGs), and 1,601 protein-coding genes were mapped to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. The degradation half-lives of DDT increased with substrate concentration from 0.1 to 10.0 mg/l, whereas decreased with temperature from 15 °C to 35 °C. Neutral condition was the most favorable for DDT biodegradation. Based on genome annotation of DDT degradation genes and the metabolites detected by GC-MS, a mineralization pathway was proposed for DDT biodegradation in which it was orderly converted into DDE/DDD, DDMU, DDOH, and DDA via dechlorination, hydroxylation, and carboxylation, and ultimately mineralized to carbon dioxide. The results indicate that the isolate DDT-1 is a promising bacterial resource for the removal or detoxification of DDT residues in the environment. PMID:26888254

  9. Biodegradation of DDT by Stenotrophomonas sp. DDT-1: Characterization and genome functional analysis

    PubMed Central

    Pan, Xiong; Lin, Dunli; Zheng, Yuan; Zhang, Qian; Yin, Yuanming; Cai, Lin; Fang, Hua; Yu, Yunlong

    2016-01-01

    A novel bacterium capable of utilizing 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) as the sole carbon and energy source was isolated from a contaminated soil which was identified as Stenotrophomonas sp. DDT-1 based on morphological characteristics, BIOLOG GN2 microplate profile, and 16S rDNA phylogeny. Genome sequencing and functional annotation of the isolate DDT-1 showed a 4,514,569 bp genome size, 66.92% GC content, 4,033 protein-coding genes, and 76 RNA genes including 8 rRNA genes. Totally, 2,807 protein-coding genes were assigned to Clusters of Orthologous Groups (COGs), and 1,601 protein-coding genes were mapped to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. The degradation half-lives of DDT increased with substrate concentration from 0.1 to 10.0 mg/l, whereas decreased with temperature from 15 °C to 35 °C. Neutral condition was the most favorable for DDT biodegradation. Based on genome annotation of DDT degradation genes and the metabolites detected by GC-MS, a mineralization pathway was proposed for DDT biodegradation in which it was orderly converted into DDE/DDD, DDMU, DDOH, and DDA via dechlorination, hydroxylation, and carboxylation, and ultimately mineralized to carbon dioxide. The results indicate that the isolate DDT-1 is a promising bacterial resource for the removal or detoxification of DDT residues in the environment. PMID:26888254

  10. Simultaneous Cr(VI) reduction and phenol degradation using Stenotrophomonas sp. isolated from tannery effluent contaminated soil.

    PubMed

    Gunasundari, Dharmaraj; Muthukumar, Karuppan

    2013-09-01

    This study presents simultaneous hexavalent chromium (Cr(VI)) reduction and phenol degradation using Stenotrophomonas sp., isolated from tannery effluent contaminated soil. Phenol was used as the sole carbon and energy source for Cr(VI) reduction. The optimization of different operating parameters was done using Placket-Burman design (PBD) and Box-Behnken design (BBD). The significant operating variables identified by PBD were initial Cr(VI) and phenol concentration, pH, temperature, and reaction time. These variables were optimized by a three-level BBD and the optimum initial Cr(VI) concentration, initial phenol concentration, pH, temperature, and reaction time obtained were 16.59 mg/l, 200.05 mg/l, 7.38, 31.96 °C and 4.07 days, respectively. Under the optimum conditions, 81.27 % Cr(VI) reduction and 100 % phenol degradation were observed experimentally. The results concluded that the Stenotrophomonas sp. could be used to decontaminate the effluents containing Cr(VI) and phenol effectively. PMID:23608988

  11. Whole-genome sequence assembly of Pediococcus pentosaceus LI05 (CGMCC 7049) from the human gastrointestinal tract and comparative analysis with representative sequences from three food-borne strains

    PubMed Central

    2014-01-01

    Background Strains of Pediococcus pentosaceus from food and the human gastrointestinal tract have been widely identified, and some have been reported to reduce inflammation, encephalopathy, obesity and fatty liver in animals. In this study, we sequenced the whole genome of P. pentosaceus LI05 (CGMCC 7049), which was isolated from the fecal samples of healthy volunteers, and determined its ability to reduce acute liver injury. No other genomic information for gut-borne P. pentosaceus is currently available in the public domain. Results We obtained the draft genome of P. pentosaceus LI05, which was 1,751,578 bp in size and possessed a mean G + C content of 37.3%. This genome encoded an abundance of proteins that were protective against acids, bile salts, heat, oxidative stresses, enterocin A, arsenate and universal stresses. Important adhesion proteins were also encoded by the genome. Additionally, P. pentosaceus LI05 genes encoded proteins associated with the biosynthesis of not only three antimicrobials, including prebacteriocin, lysin and colicin V, but also vitamins and functional amino acids, such as riboflavin, folate, biotin, thiamine and gamma-aminobutyrate. A comparison of P. pentosaceus LI05 with all known genomes of food-borne P. pentosaceus strains (ATCC 25745, SL4 and IE-3) revealed that it possessed four novel exopolysaccharide biosynthesis proteins, additional putative environmental stress tolerance proteins and phage-related proteins. Conclusions This work demonstrated the probiotic properties of P. pentosaceus LI05 from the gut and the three other food-borne P. pentosaceus strains through genomic analyses. We have revealed the major genomic differences between these strains, providing a framework for understanding the probiotic effects of strain LI05, which exhibits unique physiological and metabolic properties. PMID:25349631

  12. Degradation of Microcystin-LR and RR by a Stenotrophomonas sp. Strain EMS Isolated from Lake Taihu, China

    PubMed Central

    Chen, Jian; Hu, Liang Bin; Zhou, Wei; Yan, Shao Hua; Yang, Jing Dong; Xue, Yan Feng; Shi, Zhi Qi

    2010-01-01

    A bacterial strain EMS with the capability of degrading microcystins (MCs) was isolated from Lake Taihu, China. The bacterium was tentatively identified as a Stenotrophomonas sp. The bacterium could completely consume MC-LR and MC-RR within 24 hours at a concentration of 0.7 μg/mL and 1.7 μg/mL, respectively. The degradation of MC-LR and MC-RR by EMS occurred preferentially in an alkaline environment. In addition, mlrA gene involved in the degradation of MC-LR and MC-RR was detected in EMS. Due to the limited literature this gene has rare homologues. Sequencing analysis of the translated protein from mlrA suggested that MlrA might be a transmembrane protein, which suggests a possible new protease family having unique function. PMID:20479990

  13. 77 FR 49793 - Ortho-Phthalaldehyde; Receipt of Application for Emergency Exemption, Solicitation of Public Comment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-17

    ... Comment AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. SUMMARY: EPA has received a..., Acidovorax sp., Sphingomonas parapaucimobilis, Stenotrophomonas maltophilia, Methylobacterium extorquens, and unidentified gram negative rods. This emergency exemption involves the use of a chemical which has not...

  14. Possible Role of Xanthobaccins Produced by Stenotrophomonas sp. Strain SB-K88 in Suppression of Sugar Beet Damping-Off Disease

    PubMed Central

    Nakayama, Takato; Homma, Yoshihisa; Hashidoko, Yasuyuki; Mizutani, Junya; Tahara, Satoshi

    1999-01-01

    Three antifungal compounds, designated xanthobaccins A, B, and C, were isolated from the culture fluid of Stenotrophomonas sp. strain SB-K88, a rhizobacterium of sugar beet that suppresses damping-off disease. Production of xanthobaccin A in culture media was compared with the disease suppression activities of strain SB-K88 and less suppressive strains that were obtained by subculturing. Strain SB-K88 was applied to sugar beet seeds, and production of xanthobaccin A in the rhizosphere of seedlings was confirmed by using a test tube culture system under hydroponic culture conditions; 3 μg of xanthobaccin A was detected in the rhizosphere on a per-plant basis. Direct application of purified xanthobaccin A to seeds suppressed damping-off disease in soil naturally infested by Pythium spp. We suggest that xanthobaccin A produced by strain SB-K88 plays a key role in suppression of sugar beet damping-off disease. PMID:10508056

  15. Biodegradation of C.I. Acid Red 1 by indigenous bacteria Stenotrophomonas sp. BHUSSp X2 isolated from dye contaminated soil.

    PubMed

    Kumari, Lata; Tiwary, Dhanesh; Mishra, Pradeep Kumar

    2016-03-01

    A significant proportion of xenobiotic recalcitrant azo dyes are being released in environment during carpet dyeing. The bacterial strain Stenotrophomonas sp. BHUSSp X2 was isolated from dye contaminated soil of carpet industry, Bhadohi, India. The isolated bacterial strain was identified morphologically, biochemically, and on the basis of 16S rRNA gene sequence. The isolate decolorized 97 % of C.I. Acid Red 1 (Acid RED G) at the concentration of 200 mg/l within 6 h under optimum static conditions (temperature -35 °C, pH 8, and initial cell concentration 7 × 10(7) cell/ml). Drastic reduction in dye degradation rate was observed beyond initial dye concentration from 500 mg/l (90 %), and it reaches to 25 % at 1000 mg/l under same set of conditions. The analysis related to decolorization and degradation was done using UV-Vis spectrophotometer, HPLC, and FTIR, whereas the GC-MS technique was utilized for the identification of degradation products. Phytotoxicity analysis revealed that degradation products are less toxic as compared to the original dye. PMID:25813637

  16. Complete Genome Sequencing of Stenotrophomonas acidaminiphila ZAC14D2_NAIMI4_2, a Multidrug-Resistant Strain Isolated from Sediments of a Polluted River in Mexico, Uncovers New Antibiotic Resistance Genes and a Novel Class-II Lasso Peptide Biosynthesis Gene Cluster

    PubMed Central

    Ochoa-Sánchez, Luz Edith

    2015-01-01

    Here, we report the first complete genome sequence of a Stenotrophomonas acidaminiphila strain, generated with PacBio RS II single-molecule real-time technology, consisting of a single circular chromosome of 4.13 Mb. We annotated mobile genetic elements and natural product biosynthesis clusters, including a novel class-II lasso peptide with a 7-residue macrolactam ring. PMID:26659678

  17. [Effect of the biofilm biopolymers on the microbial corrosion rate of the low-carbon steel].

    PubMed

    Borets'ka, M O; Kozlova, I P

    2007-01-01

    The relationship between exopolymer's specific production, relative carbohydrate and protein content in the biofilm exopolymers of the pure and mixed Thiobacillus thioparus and Stenotrophomonas maltophilia cultures and their corrosion activity was studied. Change of growth model of investigated cultures from plankton to biofilm led to an increase of specific exopolymer's production. In the biofilm formed by T. thioparus and S. maltophilia biofilm on the low-carbon steel surface one could observe an increase of relative protein content in the exopolymer complex in comparison with those in the pure culture. The development of such biofilms stimulatied the 7-fold corrosion activity. PMID:17977451

  18. Activities of Taurolidine In Vitro and in Experimental Enterococcal Endocarditis

    PubMed Central

    Torres-Viera, C.; Thauvin-Eliopoulos, C.; Souli, M.; DeGirolami, P.; Farris, M. G.; Wennersten, C. B.; Sofia, R. D.; Eliopoulos, G. M.

    2000-01-01

    In vitro, the antimicrobial agent taurolidine inhibited virtually all of the bacteria tested, including vancomycin-resistant enterococci, oxacillin-resistant staphylococci, and Stenotrophomonas maltophilia, at concentrations between 250 and 2,000 μg/ml. Taurolidine was not effective in experimental endocarditis. While it appears unlikely that this antimicrobial would be useful for systemic therapy, its bactericidal activity and the resistance rates found (<10−9) are favorable indicators for its possible development for topical use. PMID:10817739

  19. Understanding the influence of Tween 80 on pullulan fermentation by Aureobasidium pullulans CGMCC1234.

    PubMed

    Sheng, Long; Tang, Guiyue; Su, Peng; Zhang, Jinling; Xiao, Qian; Tong, Qunyi; Ma, Meihu

    2016-01-20

    In this paper, several new perspectives concerned with the effect of Tween 80 promoting pullulan production were presented. With the presence of Tween 80, the maximum pullulan yield increased by 41% (53.04 g/L). Meanwhile, the carbon source was consumed faster and the broth viscosity was higher. The lower final pH suggested that Tween 80 could protect the integrity of the mycelia. The dispersed filaments were not easily entangled with each other and less pellets were formed in the Tween 80 culture broth. FT-IR spectrum analysis indicated that the evaluated sample structure was coincided with commercial pullulan. The molecular weight of sample significantly dropped comparing with the control. The above findings indicated that Tween 80 facilitated the uptake of nutrient from surroundings to the microorganism and the release of pullulan into the extracellular fluid. These results were useful in better understanding the regulation and optimization of efficient pullulan fermentation. PMID:26572478

  20. Transcriptome profiling of heat-resistant strain Bacillus licheniformis CGMCC3962 producing Maotai flavor.

    PubMed

    Wu, Qun; Xu, Yan

    2012-02-29

    Although Maotai flavor liquor is exclusive due to its soy sauce flavor, knowledge of its key compound and production mechanism is still scarce until now. To gain insight into the production mechanism of soy sauce flavor, a soy sauce flavor producing strain with high efficiency and heat-resistant capability was obtained, and the metabolic mechanism of the strain was investigated with the technique of microarray profiling. Because high temperature was a key factor for soy sauce flavor production, the global gene expression of this heat-resistant strain fermented at 55 °C was analyzed. Except for the responsive increase of heat shock proteins, which maintained cell survival during heat stress, biosynthesis of cysteine was also up-regulated. In addition, some metabolites were significantly increased when cysteine was added to the fermentation medium, such as 2,3-butanediol, 3-hydroxy-2-butanone, and tetramethylpyrazine, which were important flavor compounds in soy sauce flavor liquor and might be related with soy sauce flavor. The results indicated that cysteine might play an important role in the formation of soy sauce flavor compound, and it might act as an indirect precursor or stimulator of soy sauce flavor formation. This was the first use of the microarray profiling tool to investigate the fermentative strains for Chinese traditional liquor, which would allow a deeper insight into the mechanism of the formation of soy sauce flavor compound. PMID:22283589

  1. Co-infection between influenza virus and flagellated bacteria.

    PubMed

    Mancini, Dalva Assunção Portari; Mendonça, Rita Maria Zucatelli; Dias, Andrea Luppi Fernandes; Mendonça, Ronaldo Zucatelli; Pinto, José Ricardo

    2005-01-01

    Trypsin is required in the hemagglutinin (HA) cleavage to in vitro influenza viruses activation. This HA cleavage is necessary for virus cell entry by receptor-mediated endocytosis. Bacteria in the respiratory tract are potential sources of proteases that could contribute to the cleavage of influenza virus in vivo. From 47 samples collected from horses, pigs, and from humans, influenza presence was confirmed in 13 and these samples demonstrated co-infection of influenza with flagellated bacteria, Stenotrophomonas maltophilia from the beginning of the experiments. Despite treatment with antibiotics, the bacteria remained resistant in several of the co-infected samples (48.39%). These bacteria, considered opportunistic invaders from environmental sources, are associated with viral infections in upper respiratory tract of hosts. The protease (elastase), secreted by Stenotrophomonas maltophilia plays a role in the potentiation of influenza virus infection. Proteolytic activity was detected by casein agar test. Positive samples from animals and humans had either a potentiated influenza infectivity or cytopathic effect (CPE) in MDCK and NCI H292 cells, Stenotrophomonas maltophilia were always present. Virus and bacteria were observed ultrastructurally. These in vitro findings show that microbial proteases could contribute to respiratory complications by host protease activity increasing inflammation or destroying endogenous cell protease inhibitors. PMID:16302111

  2. Histamine and cadaverine production by bacteria isolated from fresh and frozen albacore (Thunnus alalunga).

    PubMed

    Ben-Gigirey, B; Vieites Baaptista de Sousa, J M; Villa, T G; Barros-Velazquez, J

    1999-08-01

    Two hundred twenty-seven bacterial strains were isolated from fresh and frozen albacore stored either at -18 or -25 degrees C and investigated for their abilities to produce biogenic amines. As a preliminary screening, all 227 strains were tested in either Niven or Niven modified medium, which allowed the selection of 25 presumptive histamine-producing strains. High-pressure liquid chromatography revealed that only 10 of the 25 strains selected were able to produce low histamine concentrations (<25 ppm) in tryptic soy broth medium supplemented with 2% histidine. None of the 25 strains tested produced putrescine or spermine, whereas 6 strains produced spermidine. Histamine production by Stenotrophomonas maltophilia strain 25MC6 was not prevented at 4 degrees C, and the levels of this amine reached concentrations of 25.8 ppm after 6 days. Three S. maltophilia strains showed strong lysine-decarboxylating activity. Their cadaverine formation capacity was determined by high-pressure liquid chromatography in tryptic soy broth supplemented with 1% lysine; this revealed that the three S. maltophilia strains tested produced more than 700 ppm of cadaverine during the first 24 h of incubation at 37 degrees C. S. maltophilia strain 15MF, initially obtained from fresh albacore tuna, produced up to 2,399 ppm and 4,820 ppm of cadaverine after 24 and 48 h of incubation at 37 degrees C, respectively. To our knowledge, this is the first report on histamine and cadaverine production by strains of the species S. maltophilia, previously known as Pseudomonas and Xanthomonas maltophilia, isolated from fresh and frozen albacore tuna. PMID:10456749

  3. Effect of eucalyptus essential oil on respiratory bacteria and viruses.

    PubMed

    Cermelli, Claudio; Fabio, Anna; Fabio, Giuliana; Quaglio, Paola

    2008-01-01

    The activity of Eucalyptus globulus essential oil was determined for 120 isolates of Streptococcus pyogenes, 20 isolates of S. pneumoniae, 40 isolates of S. agalactiae, 20 isolates of Staphylococcus aureus, 40 isolates of Haemophilus influenzae, 30 isolates of H. parainfluenzae, 10 isolates of Klebsiella pneumoniae, 10 isolates of Stenotrophomonas maltophilia and two viruses, a strain of adenovirus and a strain of mumps virus, all obtained from clinical specimens of patients with respiratory tract infections. The cytotoxicity was evaluated on VERO cells by the MTT test. The antibacterial activity was evaluated by the Kirby Bauer paper method, minimum inhibitory concentration, and minimum bactericidal concentration. H. influenzae, parainfluenzae, and S. maltophilia were the most susceptible, followed by S. pneumoniae. The antiviral activity, assessed by means of virus yield experiments titered by the end-point dilution method for adenovirus, and by plaque reduction assay for mumps virus, disclosed only a mild activity on mumps virus. PMID:17972131

  4. Identification and discrimination of bacteria using Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Maity, Jyoti Prakash; Kar, Sandeep; Lin, Chao-Ming; Chen, Chen-Yen; Chang, Young-Fo; Jean, Jiin-Shuh; Kulp, Thomas R.

    2013-12-01

    Bacterial spectra were obtained in the wavenumber range of 4000-600 cm-1 using FTIR spectroscopy. FTIR spectral patterns were analyzed and matched with 16S-rRNA signatures of bacterial strains OS1 and OS2, isolated from oil sludge. Specific spectral bands obtained from OS1 (FJ226761), reference strain Bacillus flexus (ATCC 49095), OS2 (FJ215874) and reference strain Stenotrophomonas maltophilia (ATCC 19861) respectively, suggested that OS1 and ATCC 49095 were closely related whereas OS2 was different. The bands probably represent groups of proteins and lipids of specific bacteria. Separate peaks found in B. flexus were similar to those of OS1. The S. maltophilia (ATCC 19861) and OS2 exhibited a similar peak at 3272 cm-1. Amide bands (I, II and III) exhibited that OS1 and B. flexus were closely related, but were different from OS2. In the fingerprint region, peak at 1096 cm-1 and 1360 cm-1 exhibited the specific fingerprints of OS2 and reference strain S. maltophilia (ATCC 19861), respectively. The specific fingerprint signature was found at 1339 cm-1 for OS1 and at 1382 cm-1 for B. flexus ATCC 49095, allowing these two strains of B. flexus to be differentiated. This spectral signature originated from phospholipid and RNA components of the cell. Principle components analysis (PCA) of spectral regions exhibited with distinct sample clusters between Bacillus flexus (ATCC 49095), S. maltophilia (ATCC 19861), OS1 and OS2 in amide and fingerprint region.

  5. Bacterial strains isolated from PCB-contaminated sediments and their use for bioaugmentation strategy in microcosms.

    PubMed

    Dudov, Hana; Luk?ov, Lucia; Murnov, Slavomra; Pukrov, Andrea; Pangallo, Domenico; Dercov, Katarna

    2014-04-01

    This study was focused on the characterization of 15 bacterial strains isolated from long-term PCB-contaminated sediment located at the Strsky canal in eastern part of Slovakia, in the surroundings of a former PCB producer. PCB-degrading strains were isolated and identified as Microbacterium oleivorans, Stenotrophomonas maltophilia, Brevibacterium sp., Ochrobactrum anthropi, Pseudomonas mandelii, Rhodococcus sp., Achromobacter xylosoxidans, Stenotrophomonas sp., Ochrobactrum sp., Pseudomonas aeruginosa, and Starkeya novella by the 16S rRNA gene sequence phylogenetic analysis. This study presents a newly isolated bacterial strain S. novella with PCB-degrading ability in liquid medium as well as in sediment. For A. xylosoxidans, the bphA gene was identified. The best growth ability in the presence of all sole carbon sources (biphenyl and PCBs vapor) was obtained for Ochrobactrum sp. and Rhodococcus sp. Uncultured Achromobacter sp. showed the highest potential for bioaugmentation of PCB-contaminated sediment. PMID:23553615

  6. [Prevalence of microbiota in the digestive tract of wild females of Lutzomyia longipalpis Lutz & Neiva, 1912) (Diptera: Psychodidae)].

    PubMed

    Oliveira, S M; Moraes, B A; Gonçalves, C A; Giordano-Dias, C M; D'Almeida, J M; Asensi, M D; Mello, R P; Brazil, R P

    2000-01-01

    We dissected the digestive tract of 245 females in pools of 35 flies forming 7 groups. These flies were Lutzomyia longipalpis originating from Lapinha Cave, Lagoa Santa, Minas Gerais. Out of the 8 species of bacteria isolated there was a predominancy of Gram negative bacterias (GNB) in the group of non-fermenters of sugar belonging to the following species: Acinetobacter lwoffii, Stenotrophomonas maltophilia, Pseudomonas putida and Flavimonas orizihabitans. The group of GNB fermenters were: Enterobacter cloacae and Klebsiella ozaenae. In the Gram positive group we isolated the genera Bacillus thuringiensis and Staphylococcus spp. PMID:10967602

  7. Q-PCR based bioburden assessment of drinking water throughout treatment and delivery to the International Space Station

    NASA Technical Reports Server (NTRS)

    Newcombe, David; Stuecker, Tara; La Duc, Myron; Venkateswaran, Kasthuri

    2005-01-01

    Previous studies indicated evidence of opportunistic pathogens samples obtained during missions to the International Space Station (ISS). This study utilized TaqMan quantitative PCR to determine specific gene abundance in potable and non-potable ISS waters. Probe and primer sets specific to the small subunit rRNA genes were used to elucidate overall bacterial rRNA gene numbers. while those specific for Burkholderia cepacia and Stenotrophomonas maltophilia were optimized and used to probe for the presence of these two opportunistic pathogens. This research builds upon previous microbial diversity studies of ISS water and demonstrates the utility of Q-PCR tool to examine water quality.

  8. Antibiotic-resistant gram-negative bacterial infections in patients with cancer.

    PubMed

    Perez, Federico; Adachi, Javier; Bonomo, Robert A

    2014-11-15

    Patients with cancer are at high risk for infections caused by antibiotic resistant gram-negative bacteria. In this review, we summarize trends among the major pathogens and clinical syndromes associated with antibiotic resistant gram-negative bacterial infection in patients with malignancy, with special attention to carbapenem and expanded-spectrum β-lactam resistance in Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia--all major threats to our cancer patients. Optimal therapy for these antibiotic-resistant pathogens still remains to be determined. PMID:25352627

  9. Effects of Efflux Pump Inhibitors on Colistin Resistance in Multidrug-Resistant Gram-Negative Bacteria.

    PubMed

    Ni, Wentao; Li, Yanjun; Guan, Jie; Zhao, Jin; Cui, Junchang; Wang, Rui; Liu, Youning

    2016-05-01

    We tested the effects of various putative efflux pump inhibitors on colistin resistance in multidrug-resistant Gram-negative bacteria. Addition of 10 mg/liter cyanide 3-chlorophenylhydrazone (CCCP) to the test medium could significantly decrease the MICs of colistin-resistant strains. Time-kill assays showed CCCP could reverse colistin resistance and inhibit the regrowth of the resistant subpopulation, especially in Acinetobacter baumannii and Stenotrophomonas maltophilia These results suggest colistin resistance in Gram-negative bacteria can be suppressed and reversed by CCCP. PMID:26953203

  10. Use of loop-mediated isothermal amplification to detect six groups of pathogens causing secondary lower respiratory bacterial infections in horses.

    PubMed

    Kinoshita, Yuta; Niwa, Hidekazu; Katayama, Yoshinari

    2015-06-01

    Microbial substitution occasionally occurs following the administration of antimicrobials to horses that have pneumonia or pleuropneumonia. Four specific loop-mediated isothermal amplification (LAMP) assays were developed to detect some equine respiratory pathogens, namely strains of the Bacteroides-Prevotella group, Klebsiella pneumoniae, Stenotrophomonas maltophilia, and Staphylococcus aureus. These four LAMP assays and two previously published LAMP assays targeting Escherichia coli or Pseudomonas aeruginosa were used on clinical respiratory specimens and a high accordance found between the results of the LAMP assays and bacterial culture. Use of these LAMP assays could enable rapid detection of pathogenic bacteria and swift administration of the appropriate antimicrobials. PMID:25846404

  11. Prevention of biofilm colonization by Gram-negative bacteria on minocycline-rifampin-impregnated catheters sequentially coated with chlorhexidine.

    PubMed

    Jamal, Mohamed A; Rosenblatt, Joel S; Hachem, Ray Y; Ying, Jiang; Pravinkumar, Egbert; Nates, Joseph L; Chaftari, Anne-Marie P; Raad, Issam I

    2014-01-01

    Resistant Gram-negative bacteria are increasing central-line-associated bloodstream infection threats. To better combat this, chlorhexidine (CHX) was added to minocycline-rifampin (M/R) catheters. The in vitro antimicrobial activity of CHX-M/R catheters against multidrug resistant, Gram-negative Acinetobacter baumannii, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia was tested. M/R and CHX-silver sulfadiazine (CHX/SS) catheters were used as comparators. The novel CHX-M/R catheters were significantly more effective (P < 0.0001) than CHX/SS or M/R catheters in preventing biofilm colonization and showed better antimicrobial durability. PMID:24165191

  12. Non-fermenters in human infections.

    PubMed

    Arora, Usha; Aggarwal, Aruna; Sofat, Saroj

    2003-04-01

    One thousand and one hundred thirty non-fermenting gram negative bacteria were isolated from various samples. Of these, Pseudomonas aeruginosa was the commonest isolate (72.83%) followed by Acinetobacter anitratus (8.4%), Alcaligenes faecalis (7.6%), Acinetobacter lwoffi (4.4%), Pseudomonas flourescens (2.4%), Schwanella putrefaciens (1.6%), Stenotrophomonas maltophilia (1.6%), Pseudomonas putida (0.4%), Bravundimonas vesicularis (0.4%) and Flavobacterium meningosepticum (0.4%). Antibiotic sensitivity pattern showed multiple drug resistance pattern with majority of the isolates being resistance to two or more drugs. PMID:15022936

  13. Acute tubular necrosis associated with propylene glycol from concomitant administration of intravenous lorazepam and trimethoprim-sulfamethoxazole.

    PubMed

    Hayman, Marybeth; Seidl, Edward C; Ali, Median; Malik, Khalid

    2003-09-01

    A 46-year-old morbidly obese man was admitted to the medical intensive care unit with respiratory failure. He required pressure-control ventilation and high levels of sedation with continuous-infusion lorazepam. He developed Stenotrophomonas maltophilia pneumonia; treatment included scheduled intravenous trimethoprim-sulfamethoxazole. Each of these drugs contain several hundred milligrams/milliliter of propylene glycol. On day 17 of his hospital course, 3 days after starting the trimethoprim-sulfamethoxazole, the patient developed acute renal failure consistent with acute tubular necrosis. Propylene glycol toxicity was suspected; therefore, all drugs containing propylene glycol were discontinued, and laboratory data were collected. A marked osmol gap, metabolic acidosis, and renal toxicity were attributed to both continuous and large intermittent doses of intravenous propylene glycol. Particular attention should be paid to the total amount of propylene glycol provided to patients from administered drugs. Patients in the intensive care setting who require high doses of intravenous lorazepam for sedation, as well as antimicrobial therapy with trimethoprim-sulfamethoxazole for treatment of either Stenotrophomonas maltophilia or Pneumocystis carinii pneumonia, may be at increased risk for propylene glycol toxicity and should be monitored closely. PMID:14524651

  14. Evaluation of colistin susceptibility in multidrug-resistant clinical isolates from cystic fibrosis, France.

    PubMed

    Biswas, S; Dubus, J-C; Reynaud-Gaubert, M; Stremler, N; Rolain, J-M

    2013-11-01

    The emergence of multidrug-resistant (MDR) bacteria in cystic fibrosis (CF) patients has led to the use of colistin drug and the emergence of colistin-resistant Gram-negative bacteria. The aim of this study was to compare the disk diffusion and Etest methods for colistin susceptibility testing on MDR bacteria associated with CF from Marseille, France. Forty-nine MDR clinical isolates (27 Stenotrophomonas maltophilia, 22 Achromobacter xylosoxidans) were used in this study. Disk diffusion and Etest assays were used to assess the reliability of these two techniques. For S. maltophilia, 25 out of 27 isolates had low minimum inhibitory concentrations (MICs, 0.125-0.75 mg/L), whereas two isolates displayed high MICs (32 mg/L). Similarly, 19 out of 22 A. xylosoxidans isolates had low MICs (0.75-3.0 mg/L), whereas three isolates had high MICs (32-256 mg/L). The diameters of zone inhibition with a 50-μg colistin disk displayed a good correlation with the MICs obtained by the Etest. Susceptible and resistant strains were eventually separated using a disk diffusion assay at a cut-off of ≤ 12 mm for a 50-μg disk. Colistin displayed excellent activity against S. maltophilia and A. xylosoxidans and the disk diffusion assay could be confidently used to determine the susceptibility to colistin for MDR Gram-negative bacteria in the context of CF. PMID:23719852

  15. Non-fermentative gram-negative bacteria in hospital tap water and water used for haemodialysis and bronchoscope flushing: prevalence and distribution of antibiotic resistant strains.

    PubMed

    Vincenti, Sara; Quaranta, Gianluigi; De Meo, Concetta; Bruno, Stefania; Ficarra, Maria Giovanna; Carovillano, Serena; Ricciardi, Walter; Laurenti, Patrizia

    2014-11-15

    This study provides a detailed description of the distribution of non-fermentative gram-negative bacteria (NFGNB) collected in water sources (tap water and water used for haemodialysis and bronchoscope flushing) from different wards of a tertiary care hospital. The aim is to identify risk practices for patients or to alert clinicians to the possible contamination of environment and medical devices. The resistance profile of NFGNB environmental isolates has shown that more than half (55.56%) of the strains isolated were resistant to one or more antibiotics tested in different antimicrobial categories. In particular, 38.89% of these strains were multidrug resistant (MDR) and 16.67% were extensively drug resistant (XDR). The most prevalent bacterial species recovered in water samples were Pseudomonas aeruginosa, Pseudomonas fluorescens, Ralstonia pickettii and Stenotrophomonas maltophilia. Analysis of antibiotic resistance rates has shown remarkable differences between Pseudomonadaceae (P. aeruginosa and P. fluorescens) and emerging pathogens, such as S. maltophilia and R. pickettii. Multidrug resistance can be relatively common among nosocomial isolates of P. aeruginosa, which represent the large majority of clinical isolates; moreover, our findings highlight that the emergent antibiotic resistant opportunistic pathogens, such as R. pickettii and S. maltophilia, isolated from hospital environments could be potentially more dangerous than other more known waterborne pathogens, if not subjected to surveillance to direct the decontamination procedures. PMID:25173861

  16. Nontuberculous Mycobacteria, Fungi, and Opportunistic Pathogens in Unchlorinated Drinking Water in the Netherlands

    PubMed Central

    van der Kooij, Dick

    2013-01-01

    The multiplication of opportunistic pathogens in drinking water supplies might pose a threat to public health. In this study, distributed unchlorinated drinking water from eight treatment plants in the Netherlands was sampled and analyzed for fungi, nontuberculous mycobacteria (NTM), and several opportunistic pathogens by using selective quantitative PCR methods. Fungi and NTM were detected in all drinking water samples, whereas Legionella pneumophila, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Aspergillus fumigatus were sporadically observed. Mycobacterium avium complex and Acanthamoeba spp. were not detected. Season had no influence on the occurrence of these organisms, except for NTM and S. maltophilia, which were present in higher numbers in the summer. Opportunistic pathogens were more often observed in premise plumbing water samples than in samples from the distribution system. The lowest number of these organisms was observed in the finished water at the plant. Thus, fungi, NTM, and some of the studied opportunistic pathogens can multiply in the distribution and premise plumbing systems. Assimilable organic carbon (AOC) and/or total organic carbon (TOC) had no clear effects on fungal and NTM numbers or on P. aeruginosa- and S. maltophilia-positive samples. However, L. pneumophila was detected more often in water with AOC concentrations above 10 μg C liter−1 than in water with AOC levels below 5 μg C liter−1. Finally, samples that contained L. pneumophila, P. aeruginosa, or S. maltophilia were more frequently positive for a second opportunistic pathogen, which shows that certain drinking water types and/or sampling locations promote the growth of multiple opportunistic pathogens. PMID:23160134

  17. Complete genome sequence of a psychotrophic Arthrobacter strain A3 (CGMCC 1.8987), a novel long-chain hydrocarbons producer.

    PubMed

    Sun, Haili; Gao, Tianpeng; Chen, Ximing; Hitchings, Matthew D; Li, Shuyan; Chen, Tao; Zhang, Hua; An, Lizhe; Dyson, Paul

    2016-03-20

    Arthrobacter strain A3, a psychotrophic bacterium isolated from the Tian Shan Mountain of China, can degrade the cellulose and synthesis the long-chain hydrocarbons efficiently in low temperature. Here we report the complete genome sequence of this bacterium. The complete genome sequence of Arthrobacter strain A3, consisting of a cycle chromosome with a size of 4.26 Mbp and a cycle plasmid with a size of 194kbp. In this genome, a hydrocarbon biosynthesis gene cluster (oleA, oleB/oleC and oleD) was identified. To resistant the extreme environment, this strain contains a unique mycothiol-biosynthetic pathway (mshA-D), which has not been found in other Arthrobacter species before. The availability of this genome sequence allows us to investigate the genetic basis of adaptation to growth in a nutrient-poor permafrost environment and to evaluate of the biofuel-synthetic potential of this species. PMID:26854946

  18. Capillary isoelectric focusing and fluorometric detection of proteins and microorganisms dynamically modified by poly(ethylene glycol) pyrenebutanoate.

    PubMed

    Horka, Marie; Ruzicka, Filip; Horký, Jaroslav; Holá, Veronika; Slais, Karel

    2006-12-15

    The nonionogenic pyrene-based tenside, poly(ethylene glycol) pyrenebutanoate, was prepared and applied in capillary isoelectric focusing with fluorometric detection. This dye was used here as a buffer additive in capillary isoelectric focusing for a dynamic modification of the sample of proteins and microorganisms. The values of the isoelectric points of the labeled bioanalytes were calculated with use of the fluorescent pI markers and were found comparable with pI of the native compounds. The mixed cultures of proteins and microorganisms, Escherichia coli CCM 3954, Staphylococcus epidermidis CCM 4418, Proteus vulgaris, Enterococcus faecalis CCM 4224, and Stenotrophomonas maltophilia, the strains of the yeast cells, Candida albicans CCM 8180, Candida krusei, Candida parapsilosis, Candida glabrata, Candida tropicalis, and Saccharomyces cerevisiae were reproducibly focused and separated by the suggested technique. Using UV excitation for the on-column fluorometric detection, the minimum detectable amount was down to 10 cells injected on the separation capillary. PMID:17165837

  19. Evaluation of the Colorimetric VITEK 2 Card for Identification of Gram-Negative Nonfermentative Rods: Comparison to 16S rRNA Gene Sequencing▿

    PubMed Central

    Zbinden, A.; Böttger, E. C.; Bosshard, P. P.; Zbinden, R.

    2007-01-01

    Ninety strains of a collection of well-identified clinical isolates of gram-negative nonfermentative rods collected over a period of 5 years were evaluated using the new colorimetric VITEK 2 card. The VITEK 2 colorimetric system identified 53 (59%) of the isolates to the species level and 9 (10%) to the genus level; 28 (31%) isolates were misidentified. An algorithm combining the colorimetric VITEK 2 card and 16S rRNA gene sequencing for adequate identification of gram-negative nonfermentative rods was developed. According to this algorithm, any identification by the colorimetric VITEK 2 card other than Achromobacter xylosoxidans, Acinetobacter sp., Burkholderia cepacia complex, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia should be subjected to 16S rRNA gene sequencing when accurate identification of nonfermentative rods is of concern. PMID:17507509

  20. Life-threatening coagulopathy and hypofibrinogenaemia induced by tigecycline in a patient with advanced liver cirrhosis.

    PubMed

    Rossitto, Giacomo; Piano, Salvatore; Rosi, Silvia; Simioni, Paolo; Angeli, Paolo

    2014-06-01

    Bacterial infections because of multidrug-resistant (MDR) bacteria are spreading worldwide. In patients with advanced liver cirrhosis, healthcare-acquired and hospital-acquired infections are common and are frequently sustained by MDR bacteria. In these settings, tigecycline, a new antibiotic, has been shown to be useful in the treatment of MDR bacteria, and it has been proposed for the treatment of hospital-acquired infections in patients with cirrhosis. Nevertheless, poor data exist on the safety profile of tigecycline in patients with cirrhosis. Here, an experience is reported in a female patient with advanced liver cirrhosis, who developed sepsis by an MDR Stenotrophomonas maltophilia and was treated with tigecycline. She experienced life-threatening side effects consisting of severe coagulopathy with hypofibrinogenaemia and subsequent gastrointestinal haemorrhage. The side effect disappeared after the withdrawal of tigecycline. Therefore, a strict monitoring of coagulation parameters in patients with cirrhosis treated with tigecycline is recommended. PMID:24667348

  1. Tackling antibiotic resistance in febrile neutropenia: current challenges with and recommendations for managing infections with resistant Gram-negative organisms.

    PubMed

    Nouér, Simone A; Nucci, Marcio; Anaissie, Elias

    2015-10-01

    Multidrug resistant (MDR) Gram-negative bacteria (GNB) have emerged as important pathogens and a serious challenge in the management of neutropenic patients worldwide. The great majority of infections are caused by the Enterobacteriaceae (especially Escherichia coli and Klebsiella spp.) and Pseudomonas aeruginosa, and less frequently Acinetobacter spp. and Stenotrophomonas maltophilia. A broader-spectrum empiric antibiotic regimen is usually recommended in patients with a history of prior bloodstream infection caused by a MDR GNB, in those colonized by a MDR GNB, and if MDR GNBs are frequently isolated in the initial blood cultures. In any situation, de-escalation to standard empiric regimen is advised if infection with MDR GNB is not documented. PMID:26115679

  2. An evaluation of microbial and chemical contamination sources related to the deterioration of tap water quality in the household water supply system.

    PubMed

    Lee, Yoonjin

    2013-09-01

    The predominant microorganisms in samples taken from shower heads in residences in the Korean city "N" were Stenotrophomonas maltophilia, Sphingomonas paucimobilis, Acidovorax temperans, and Microbacterium lacticum. Legionella was not detected in this case. The volatile organic compounds (VOCs) vinylacetate, NN-DMA, cis-1,2-dichloroethylene, epichlorohydrin, and styrene were measured in five types of plastic pipes: PVC, PB, PP, PE, and cPVC. The rate of multiplication of the heterotrophic plate count (HPC) attached on the copper pipe in contact with hot tap water was higher than the rate for the copper pipe in contact with cold tap water. Biofilm accumulation on stainless steel pipes with added acetate (3 mg/L) was 2.56 times higher than the non-supplemented condition. Therefore, the growth of HPC in the pipe system was affected by the type and availability of nutrients and depended on variables such as heating during the hot water supply. PMID:24018837

  3. An Evaluation of Microbial and Chemical Contamination Sources Related to the Deterioration of Tap Water Quality in the Household Water Supply System

    PubMed Central

    Lee, Yoonjin

    2013-01-01

    The predominant microorganisms in samples taken from shower heads in residences in the Korean city “N” were Stenotrophomonas maltophilia, Sphingomonas paucimobilis, Acidovorax temperans, and Microbacterium lacticum. Legionella was not detected in this case. The volatile organic compounds (VOCs) vinylacetate, NN-DMA, cis-1,2-dichloroethylene, epichlorohydrin, and styrene were measured in five types of plastic pipes: PVC, PB, PP, PE, and cPVC. The rate of multiplication of the heterotrophic plate count (HPC) attached on the copper pipe in contact with hot tap water was higher than the rate for the copper pipe in contact with cold tap water. Biofilm accumulation on stainless steel pipes with added acetate (3 mg/L) was 2.56 times higher than the non-supplemented condition. Therefore, the growth of HPC in the pipe system was affected by the type and availability of nutrients and depended on variables such as heating during the hot water supply. PMID:24018837

  4. Cutaneous and pulmonary mycosis in green anacondas (Euncectes murinus).

    PubMed

    Miller, Debra L; Radi, Zaher A; Stiver, Shane L; Thornhill, Timothy D

    2004-12-01

    Two dead, captive green anacondas (Eunectes murinus), including one male and one female, submitted for necropsy were in poor body condition, having multiple, scattered, dark red foci on the scales and mottled lungs. Both snakes had severe mycotic dermatitis. In addition, the male snake had mycotic stomatitis, and the female snake had mycotic pneumonia. Trichophyton sp., Verticillium sp., and Alternaria sp. were isolated from the dermal lesions. The pulmonary lesions were morphologically consistent with Aspergillus sp. Bacterial organisms isolated from skin and internal organs included Chryseobacterium meningosepticum, Stenotrophomonas maltophilia, Aeromonas hydrophila, and Providencia rettgeri. Mycotic diseases can be devastating to reptiles, and suboptimal husbandry and captivity were likely the predisposing factors that led to opportunistic invasion in these snakes. PMID:15732602

  5. The influence of bioaugmentation and biosurfactant addition on bioremediation efficiency of diesel-oil contaminated soil: feasibility during field studies.

    PubMed

    Szulc, Alicja; Ambrożewicz, Damian; Sydow, Mateusz; Ławniczak, Łukasz; Piotrowska-Cyplik, Agnieszka; Marecik, Roman; Chrzanowski, Łukasz

    2014-01-01

    The study focused on assessing the influence of bioaugmentation and addition of rhamnolipids on diesel oil biodegradation efficiency during field studies. Initial laboratory studies (measurement of emitted CO2 and dehydrogenase activity) were carried out in order to select the consortium for bioaugmentation as well as to evaluate the most appropriate concentration of rhamnolipids. The selected consortium consisted of following bacterial taxa: Aeromonas hydrophila, Alcaligenes xylosoxidans, Gordonia sp., Pseudomonas fluorescens, Pseudomonas putida, Rhodococcus equi, Stenotrophomonas maltophilia, Xanthomonas sp. It was established that the application of rhamnolipids at 150 mg/kg of soil was most appropriate in terms of dehydrogenase activity. Based on the obtained results, four treatment methods were designed and tested during 365 days of field studies: I) natural attenuation; II) addition of rhamnolipids; III) bioaugmentation; IV) bioaugmentation and addition of rhamnolipids. It was observed that bioaugmentation contributed to the highest diesel oil biodegradation efficiency, whereas the addition of rhamnolipids did not notably influence the treatment process. PMID:24291585

  6. Microbial contamination of suction tubes attached to suction instruments and preventive methods.

    PubMed

    Yorioka, Katsuhiro; Oie, Shigeharu; Kamiya, Akira

    2010-03-01

    We investigated the microbial contamination of suction tubes attached to wall-type suction instruments. Microbial contamination of suction tubes used for endoscopy or sputum suction in hospital wards was examined before and after their disinfection. In addition, disinfection and washing methods for suction tubes were evaluated. Suction tubes (n=33) before disinfection were contaminated with 10(2)-10(8) colony-forming units (cfu)/tube. The main contaminants were Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia. The suction tubes were disinfected with sodium hypochlorite (n=11) or hot water (n=11), or by an automatic tube cleaner (n=11). After 2-h immersion in 0.1% (1,000 ppm) sodium hypochlorite, 10(3)-10(7) cfu/tube of bacteria were detected in all 11 tubes examined. After washing in hot running water (65 degrees C), 10(3)-10(7) cfu/tube were detected in 3 of the 11 examined tubes. The bacteria detected in the suction tubes after disinfection with sodium hypochlorite or hot water were P. aeruginosa, A. baumannii, and S. maltophilia. On the other hand, after washing with warm water (40 degrees C) using the automatic tube cleaner, contamination was found to be <20 cfu/tube (lower detection limit, 20 cfu/tube) in all 11 tubes examined. These results suggest the usefulness of washing with automatic tube cleaners. PMID:20332576

  7. Bacteria associated with Amblyomma cajennense tick eggs

    PubMed Central

    Machado-Ferreira, Erik; Vizzoni, Vinicius Figueiredo; Piesman, Joseph; Gazeta, Gilberto Salles; Soares, Carlos Augusto Gomes

    2015-01-01

    Abstract Ticks represent a large group of pathogen vectors that blood feed on a diversity of hosts. In the Americas, the Ixodidae ticks Amblyomma cajennense are responsible for severe impact on livestock and public health. In the present work, we present the isolation and molecular identification of a group of culturable bacteria associated with A. cajennense eggs from females sampled in distinct geographical sites in southeastern Brazil. Additional comparative analysis of the culturable bacteria from Anocentor nitens, Rhipicephalus sanguineus and Ixodes scapularis tick eggs were also performed. 16S rRNA gene sequence analyses identified 17 different bacterial types identified as Serratia marcescens, Stenotrophomonas maltophilia, Pseudomonas fluorescens, Enterobacter spp., Micrococcus luteus, Ochrobactrum anthropi, Bacillus cereus and Staphylococcus spp., distributed in 12 phylogroups. Staphylococcus spp., especially S. sciuri, was the most prevalent bacteria associated with A. cajennense eggs, occurring in 65% of the samples and also frequently observed infecting A. nitens eggs. S. maltophilia, S. marcescens and B. cereus occurred infecting eggs derived from specific sampling sites, but in all cases rising almost as pure cultures from infected A. cajennense eggs. The potential role of these bacterial associations is discussed and they possibly represent new targets for biological control strategies of ticks and tick borne diseases. PMID:26537602

  8. Antimicrobial Susceptibilities of Commonly Encountered Bacterial Isolates to Fosfomycin Determined by Agar Dilution and Disk Diffusion Methods▿

    PubMed Central

    Lu, Ching-Lan; Liu, Chia-Ying; Huang, Yu-Tsung; Liao, Chun-Hsing; Teng, Lee-Jene; Turnidge, John D.; Hsueh, Po-Ren

    2011-01-01

    We studied the antimicrobial activity of fosfomycin against 960 strains of commonly encountered bacteria associated with urinary tract infection using standard agar dilution and disk diffusion methods. Species studied included 3 common species of Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia; methicillin-susceptible and -resistant Staphylococcus aureus; and vancomycin-susceptible and resistant Enterococcus faecalis and E. faecium. MICs and inhibition zone diameters were interpreted in accordance with both the currently recommended Clinical and Laboratory Standards Institute (CLSI) criteria for urinary tract isolates of Escherichia coli and Enterococcus faecalis and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria for Enterobacteriaceae. Tentative zone diameter interpretive criteria were developed for species not currently published by CLSI or EUCAST. Escherichia coli was uniformly susceptible to fosfomycin, as were most strains of Klebsiella pneumoniae and Enterobacter cloacae. A. baumannii was resistant to fosfomycin, while the prevalence of resistance in P. aeruginosa and S. maltophilia was greatly affected by the choice of MIC breakpoint. New tentative zone diameter criteria for K. pneumoniae, E. cloacae, S. aureus, and E. faecium were able to be set, providing some interim laboratory guidance for disk diffusion until further breakpoint evaluations are undertaken by CLSI and EUCAST. PMID:21670185

  9. Coexistence among Epiphytic Bacterial Populations Mediated through Nutritional Resource Partitioning

    PubMed Central

    Wilson, Mark; Lindow, Steven E.

    1994-01-01

    The levels of coexistence between Pseudomonas syringae and various nonpathogenic epiphytic species in the phyllosphere of beans (Phaseolus vulgaris) were assessed by using replacement series. The epiphytic species Pseudomonas fluorescens, Pantoea agglomerans, Stenotrophomonas maltophilia, and Methylobacterium organophilum were all capable of exhibiting higher levels of coexistence with P. syringae than was observed with a near-isogenic P. syringae strain pair. The ecological similarity of the epiphytes was estimated with niche overlap indices derived from in vitro carbon source utilization profiles. The level of coexistence of the epiphytes was inversely correlated with the ecological similarity of the strains. Hence, the level of coexistence between the epiphytes was proportional to the degree of niche differentiation, defined as the ability to utilize carbon sources not utilized by a competing strain. Comparisons of utilization profiles for groups of carbon sources (amino acids, organic acids, and carbohydrates) indicated the types of carbon sources for which the strains likely competed in the bean phyllosphere. P. fluorescens and P. syringae strains probably competed for most carbon sources. S. maltophilia and M. organophilum strains probably competed with P. syringae for most organic acids but few amino acids or carbohydrates. P. agglomerans strains probably competed with P. syringae for most amino acids and organic acids but few carbohydrates. A variable level of coexistence observed between P. agglomerans and P. syringae probably reflected the variability in abundance in the bean phyllosphere of the carbohydrates that P. agglomerans utilized exclusively. PMID:16349462

  10. Effects of pathology dyes on Raman bone spectra

    NASA Astrophysics Data System (ADS)

    Esmonde-White, Karen A.; Esmonde-White, Francis W. L.; Morris, Michael D.; Roessler, Blake J.

    2013-05-01

    We report an overlooked source of artifacts for clinical specimens, where unexpected and normally negligible contaminants can skew the interpretation of results. During an ongoing study of bone fragments from diabetic osteomyelitis, strong Raman signatures were found, which did not correspond with normal bone mineral or matrix. In a bone biopsy from the calcaneus of a patient affected by diabetic osteomyelitis, Raman microspectroscopic analysis revealed regions with both abnormal mineral and degraded collagen in addition to normal bone. Additional bands indicated a pathological material. Stenotrophomonas maltophilia was identified in the wound culture by independent microbiologic examination. We initially assigned the unusual bands to xanthomonadin, a bacterial pigment from S. maltophilia. However, the same bands were also found more than a year later on a second specimen that had been noticeably contaminated with pathology marking dye. Drop deposition/Raman spectroscopy of commonly used pathology dyes revealed that a blue tissue-marking dye was responsible for the unusual bands in both specimens, even in the first specimen where there was no visible evidence of contamination.

  11. Mir space station bacteria responses to modeled reduced gravity under starvation conditions

    NASA Astrophysics Data System (ADS)

    Baker, Paul W.; Leff, Laura G.

    2006-01-01

    Isolates from the Mir space station identified as Pseudomonas sp. and Stenotrophomonas maltophilia were subjected to clinorotation to model reduced gravity conditions in water in slow turning lateral vessels (STLVs). To examine cells in varying physiological states, bacteria were enumerated based on the Live/Dead BacLight kit, DAPI (4',6-diamidino-2-phenylindole) staining, fluorescent in situ hybridization (FISH), and colony forming units (CFU). Both Pseudomonas sp. and S. maltophilia showed a slight increase in abundance over time but only cells of Pseudomonas sp. were affected by modeled reduced gravity. For Pseudomonas sp. numbers of DAPI stained cells were significantly higher under modeled reduced gravity compared to normal gravity. In addition, the abundance of cells attached to stainless steel disks, on one sampling date, was greater for the Pseudomonas isolate under modeled reduced gravity than normal gravity. The isolates examined did not appear to appreciably enter into a viable, but not culturable state during the experiments. In general, differences between treatments were not great, demonstrating that responses to reduced gravity are less apparent under starvation conditions, compared to earlier studies which used more rich nutrient sources.

  12. Emergence of unusual nonfermenting Gram-negative nosocomial pathogens in a Saudi hospital.

    PubMed

    Asaad, Ahmed Morad; Al-Ayed, Mohamed Said Zayed; Qureshi, Mohamed Ansar

    2013-01-01

    This study aimed to determine the frequency of isolation and prevalence of drug resistance in nonfermenting Gram-negative bacilli (NFGNB) other than Pseudomonas aeruginosa and predisposing factors for the acquisition of nosocomial infections caused by these emerging pathogens in a Saudi tertiary care hospital. A total of 125 nonduplicating NFGNB nosocomial strains were isolated, of these, 68 (54.4%) were Acinetobacter baumannii, 26 (20.8%) Stenotrophomonas maltophilia, 14 (11.2%) Alcaligenes faecalis, 12 (9.6%) Chryseobacterium indologenes, and 5 (4%) Ralstonia pickettii. MICs of 11 antibiotics were determined using the reference broth microdilution method. With the exception of colistin that inhibited 100% of A. baumannii isolates, trimethoprim/sulfamethoxazole that inhibited 100% of S. maltophilia isolates, and carbapenems that inhibited 100% of A. faecalis isolates, none of the tested antimicrobial agents inhibited 100% of the other NFGNB spp. Our results emphasize that clinicians and microbiologists should consider A. faecalis, C. indologenes, and R. pickettii as emerging nosocomial pathogens. In addition, local resistance data are essential for helping physicians in deciding an appropriate antibiotic for empirical therapy of infections with these emerging and unusual NFGNB. PMID:24270139

  13. Antimicrobial evaluation of quaternary ammonium polyethyleneimine nanoparticles against clinical isolates of pathogenic bacteria.

    PubMed

    Ortega, Agustín; Farah, Shady; Tranque, Pedro; Ocaña, Ana V; Nam-Cha, Syong H; Beyth, Nurit; Gómez-Roldán, Carmen; Pérez-Tanoira, Ramón; Domb, Abraham J; Pérez-Martínez, Francisco C; Pérez-Martínez, Juan

    2015-12-01

    Peritonitis is a disease caused by bacterial strains that have become increasingly resistant to many antibiotics. The development of alternative therapeutic compounds is the focus of extensive research, so novel nanoparticles (NPs) with activity against antibiotic-resistant bacteria should be developed. In this study, the antibacterial activity of quaternary ammonium polyethyleneimine (QA-PEI) NPs was evaluated against Streptococcus viridans, Stenotrophomonas maltophilia and Escherichia coli. To appraise the antibacterial activity, minimal inhibitory concentration (MIC), minimal bactericidal concentration and bactericidal assays were utilised with different concentrations (1.56-100 µg/ml) of QA-PEI NPs. Moreover, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and annexin V/propidium iodide toxicity assays were performed in cell cultures. MICs for S. maltophilia and E. coli isolates were 12.5 and 25 µg/ml, respectively, whereas the MIC for S. viridans was 100 µg/ml. Furthermore, the growth curve assays revealed that these QA-PEI NPs at a concentration of 12.5 µg/ml significantly inhibited bacterial growth for the bacterial isolates studied. On the other hand, QA-PEI NPs lacked significant toxicity for cells when used at concentrations up to 50 μg/ml for 48 h. The present findings reveal the potential therapeutic value of this QA-PEI NPs as alternative antibacterial agents for peritonitis, especially against Gram-negative bacteria. PMID:26647809

  14. Bacteria associated with Amblyomma cajennense tick eggs.

    PubMed

    Machado-Ferreira, Erik; Vizzoni, Vinicius Figueiredo; Piesman, Joseph; Gazeta, Gilberto Salles; Soares, Carlos Augusto Gomes

    2015-12-01

    Ticks represent a large group of pathogen vectors that blood feed on a diversity of hosts. In the Americas, the Ixodidae ticks Amblyomma cajennense are responsible for severe impact on livestock and public health. In the present work, we present the isolation and molecular identification of a group of culturable bacteria associated with A. cajennense eggs from females sampled in distinct geographical sites in southeastern Brazil. Additional comparative analysis of the culturable bacteria from Anocentor nitens, Rhipicephalus sanguineus and Ixodes scapularis tick eggs were also performed. 16S rRNA gene sequence analyses identified 17 different bacterial types identified as Serratia marcescens, Stenotrophomonas maltophilia, Pseudomonas fluorescens, Enterobacter spp., Micrococcus luteus, Ochrobactrum anthropi, Bacillus cereus and Staphylococcus spp., distributed in 12 phylogroups. Staphylococcus spp., especially S. sciuri, was the most prevalent bacteria associated with A. cajennense eggs, occurring in 65% of the samples and also frequently observed infecting A. nitens eggs. S. maltophilia, S. marcescens and B. cereus occurred infecting eggs derived from specific sampling sites, but in all cases rising almost as pure cultures from infected A. cajennense eggs. The potential role of these bacterial associations is discussed and they possibly represent new targets for biological control strategies of ticks and tick borne diseases. PMID:26537602

  15. Complementary treatment of contact lens-induced corneal ulcer using honey: a case report.

    PubMed

    Majtanova, Nora; Vodrazkova, Erika; Kurilova, Veronika; Horniackova, Miroslava; Cernak, Martin; Cernak, Andrej; Majtan, Juraj

    2015-02-01

    The aim of this study was to report the complementary use of honey for treatment of a contact lens-induced corneal ulcer. A 23-year-old contact lens user presented with a corneal ulcer in her left eye. She had visual acuity reduced to hand movement. There was a history of wearing contact lenses while swimming in a lake seven days before presentation. The cultures from corneal scrapings and contact lenses were positive for Klebsiella oxytoca, Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Pseudomonas spp. The treatment with topical levofloxacin and 25% (w/v) γ-irradiated honeydew honey solution was effective and the patient achieved final best corrected visual acuity of affected eye. In addition to positive clinical outcome, honeydew honey was shown to be highly effective in vitro against ocular isolates, in particular S. maltophilia. The minimal inhibitory concentrations for honeydew honey ranged from 5% to 10%. These results demonstrate that honey is a promising antibacterial agent in management of corneal ulcers. Moreover, honey exhibits anti-biofilm and anti-inflammatory properties, and thus becomes an interesting ophthalmologic agent. PMID:25278429

  16. In vitro antimicrobial activity of "last-resort" antibiotics against unusual nonfermenting Gram-negative bacilli clinical isolates.

    PubMed

    Jacquier, Herve; Le Monnier, Alban; Carbonnelle, Etienne; Corvec, Stephane; Illiaquer, Marina; Bille, Emmanuelle; Zahar, Jean-Ralph; Jauréguy, Françoise; Fihman, Vincent; Tankovic, Jacques; Cattoir, Vincent

    2012-08-01

    In this prospective multicentric study, we assessed the in vitro antimicrobial activity of carbapenems (imipenem, meropenem, and doripenem), tigecycline, and colistin against 166 unusual nonfermenting Gram-negative bacilli (NF-GNB) clinical isolates collected from nine French hospitals during a 6-month period (from December 1, 2008, to May 31, 2009). All NF-GNB isolates were included, except those phenotypically identified as Pseudomonas aeruginosa or Acinetobacter baumannii. Minimal inhibitory concentrations (MICs) of antimicrobial agents were determined by using the E-test technique. The following microorganisms were identified: Stenotrophomonas maltophilia (n=72), Pseudomonas spp. (n=30), Achromobacter xylosoxidans (n=25), Acinetobacter spp. (n=18), Burkholderia cepacia complex (n=9), Alcaligenes faecalis (n=7), and Delftia spp. (n=5). All isolates of Acinetobacter spp., A. faecalis, and Delftia spp. were susceptible to the three carbapenems. Imipenem exhibited the lowest MICs against Pseudomonas spp., and meropenem, as compared with imipenem and doripenem, displayed an interesting antimicrobial activity against A. xylosoxidans and B. cepacia complex isolates. Conversely, no carbapenem exhibited any activity against S. maltophilia. Except for S. maltophilia isolates, tigecycline and colistin exhibited higher MICs than carbapenems, but covered most of the microorganisms tested in this study. To our knowledge, no prior study has compared antimicrobial activity of these five antibiotics, often considered as "last-resort" treatment options for resistant Gram-negative infections, against unusual NF-GNB clinical isolates. Further studies should be carried out to assess the potential clinical use of these antibiotics for the treatment of infections due to these microorganisms. PMID:22335615

  17. Bacterial communities in petroleum oil in stockpiles.

    PubMed

    Yoshida, Nobuyuki; Yagi, Kazuhiro; Sato, Daisuke; Watanabe, Noriko; Kuroishi, Takeshi; Nishimoto, Kana; Yanagida, Akira; Katsuragi, Tohoru; Kanagawa, Takahiro; Kurane, Ryuichiro; Tani, Yoshiki

    2005-02-01

    Bacterial communities in crude-oil samples from Japanese oil stockpiles were investigated by 16S rRNA gene cloning, followed by denaturing gradient gel electrophoresis (DGGE) analysis. 16S rRNA genes were successfully amplified by PCR after isooctane treatment from three kinds of crude-oil sample collected at four oil stockpiles in Japan. DGGE profiles showed that bacteria related to Ochrobactrum anthropi, Burkholderia cepacia, Stenotrophomonas maltophilia, Propionibacterium acnes, and Brevundimonas diminuta were frequently detected in most crude-oil samples. The bacterial communities differed in the sampling time and layer. Among the predominant bacteria detected in the crude oil, only three species were found for bacteria isolated on agar plates and were related to Burkholderia, Stenotrophomonas, and Propionibacterium, while Ochrobactrum sp. could not be isolated although this species seemed to be the most abundant bacterium in crude oil from the DGGE profiles. Using an archaea-specific primer set, methanogens were found in crude-oil sludge but not in crude-oil samples, indicating that methanogens might be involved in sludge formation in oil stockpiles. PMID:16233771

  18. Low Prevalence of Carbapenem-Resistant Bacteria in River Water: Resistance Is Mostly Related to Intrinsic Mechanisms.

    PubMed

    Tacão, Marta; Correia, António; Henriques, Isabel S

    2015-10-01

    Carbapenems are last-resort antibiotics to handle serious infections caused by multiresistant bacteria. The incidence of resistance to these antibiotics has been increasing and new resistance mechanisms have emerged. The dissemination of carbapenem resistance in the environment has been overlooked. The main goal of this research was to assess the prevalence and diversity of carbapenem-resistant bacteria in riverine ecosystems. The presence of frequently reported carbapenemase-encoding genes was inspected. The proportion of imipenem-resistant bacteria was on average 2.24 CFU/ml. Imipenem-resistant strains (n=110) were identified as Pseudomonas spp., Stenotrophomonas maltophilia, Aeromonas spp., Chromobacterium haemolyticum, Shewanella xiamenensis, and members of Enterobacteriaceae. Carbapenem-resistant bacteria were highly resistant to other beta-lactams such as quinolones, aminoglycosides, chloramphenicol, tetracyclines, and sulfamethoxazole/trimethoprim. Carbapenem resistance was mostly associated with intrinsically resistant bacteria. As intrinsic resistance mechanisms, we have identified the blaCphA gene in 77.3% of Aeromonas spp., blaL1 in all S. maltophilia, and blaOXA-48-like in all S. xiamenensis. As acquired resistance mechanisms, we have detected the blaVIM-2 gene in six Pseudomonas spp. (5.45%). Integrons with gene cassettes encoding resistance to aminoglycosides (aacA and aacC genes), trimethoprim (dfrB1b), and carbapenems (blaVIM-2) were found in Pseudomonas spp. Results suggest that carbapenem resistance dissemination in riverine ecosystems is still at an early stage. Nevertheless, monitoring these aquatic compartments for the presence of resistance genes and its host organisms is essential to outline strategies to minimize resistance dissemination. PMID:26430939

  19. Comparative genomics of non-pseudomonal bacterial species colonising paediatric cystic fibrosis patients.

    PubMed

    Ormerod, Kate L; George, Narelle M; Fraser, James A; Wainwright, Claire; Hugenholtz, Philip

    2015-01-01

    The genetic disorder cystic fibrosis is a life-limiting condition affecting ∼70,000 people worldwide. Targeted, early, treatment of the dominant infecting species, Pseudomonas aeruginosa, has improved patient outcomes; however, there is concern that other species are now stepping in to take its place. In addition, the necessarily long-term antibiotic therapy received by these patients may be providing a suitable environment for the emergence of antibiotic resistance. To investigate these issues, we employed whole-genome sequencing of 28 non-Pseudomonas bacterial strains isolated from three paediatric patients. We did not find any trend of increasing antibiotic resistance (either by mutation or lateral gene transfer) in these isolates in comparison with other examples of the same species. In addition, each isolate contained a virulence gene repertoire that was similar to other examples of the relevant species. These results support the impaired clearance of the CF lung not demanding extensive virulence for survival in this habitat. By analysing serial isolates of the same species we uncovered several examples of strain persistence. The same strain of Staphylococcus aureus persisted for nearly a year, despite administration of antibiotics to which it was shown to be sensitive. This is consistent with previous studies showing antibiotic therapy to be inadequate in cystic fibrosis patients, which may also explain the lack of increasing antibiotic resistance over time. Serial isolates of two naturally multi-drug resistant organisms, Achromobacter xylosoxidans and Stenotrophomonas maltophilia, revealed that while all S. maltophilia strains were unique, A. xylosoxidans persisted for nearly five years, making this a species of particular concern. The data generated by this study will assist in developing an understanding of the non-Pseudomonas species associated with cystic fibrosis. PMID:26401445

  20. Degradation and mineralization of high-molecular-weight polycyclic aromatic hydrocarbons by defined fungal-bacterial cocultures

    SciTech Connect

    Boonchan, S.; Britz, M.L.; Stanley, G.A.

    2000-03-01

    This study investigated the biodegradation of high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) in liquid media and soil by bacteria (Stenotrophomonas maltophilia VUN 10,010 and bacterial consortium VUN 10,009) and a fungus (Penicillium janthinellum VUO 10,201) that were isolated from separate creosote- and manufactured-gas plant-contaminated soils. The bacteria could use pyrene as their sole carbon and energy source in a basal salts medium (BSM) and mineralized significant amounts of benzo[a]pyrene cometabolically when pyrene was also present in BSM. P. janthinellum VUO 10,201 could not utilize any high-molecular-weight PAH as sole carbon and energy source but could partially degrade these if cultured in a nutrient broth. Although small amounts of chrysene, benz[a]pyrene, and dibenz[a,h]anthracene were degraded by axenic cultures of these isolates in BSM containing a single PAH, such conditions did not support significant microbial growth or PAH mineralization. However, significant degradation of, and microbial growth on, pyrene, chrysene, benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene, each as a single PAH in BSM, occurred when P. janthinellum VUO 10,201 and either bacterial consortium VUN 10,009 or S. maltophilia VUN 10,010 were combined in the one culture, i.e., fungal-bacterial cocultures: 25% of the benzo[a]pyrene was mineralized to CO{sub 2} by these cocultures over 49 days, accompanied by transient accumulation and disappearance of intermediates detected by high-pressure liquid chromatography. Inoculation of fungal-bacterial cocultures into PAH-contaminated soil resulted in significantly improved degradation of high-molecular-weight PAHs, benzo[a]pyrene mineralization, and reduction in the mutagenicity of organic soil extracts, compared with the indigenous microbes and soil amended with only axenic inocula.

  1. Comparative genomics of non-pseudomonal bacterial species colonising paediatric cystic fibrosis patients

    PubMed Central

    Ormerod, Kate L.; George, Narelle M.; Fraser, James A.; Wainwright, Claire

    2015-01-01

    The genetic disorder cystic fibrosis is a life-limiting condition affecting ∼70,000 people worldwide. Targeted, early, treatment of the dominant infecting species, Pseudomonas aeruginosa, has improved patient outcomes; however, there is concern that other species are now stepping in to take its place. In addition, the necessarily long-term antibiotic therapy received by these patients may be providing a suitable environment for the emergence of antibiotic resistance. To investigate these issues, we employed whole-genome sequencing of 28 non-Pseudomonas bacterial strains isolated from three paediatric patients. We did not find any trend of increasing antibiotic resistance (either by mutation or lateral gene transfer) in these isolates in comparison with other examples of the same species. In addition, each isolate contained a virulence gene repertoire that was similar to other examples of the relevant species. These results support the impaired clearance of the CF lung not demanding extensive virulence for survival in this habitat. By analysing serial isolates of the same species we uncovered several examples of strain persistence. The same strain of Staphylococcus aureus persisted for nearly a year, despite administration of antibiotics to which it was shown to be sensitive. This is consistent with previous studies showing antibiotic therapy to be inadequate in cystic fibrosis patients, which may also explain the lack of increasing antibiotic resistance over time. Serial isolates of two naturally multi-drug resistant organisms, Achromobacter xylosoxidans and Stenotrophomonas maltophilia, revealed that while all S. maltophilia strains were unique, A. xylosoxidans persisted for nearly five years, making this a species of particular concern. The data generated by this study will assist in developing an understanding of the non-Pseudomonas species associated with cystic fibrosis. PMID:26401445

  2. Detection and location of OP-degrading activity: A model to integrate education and research.

    PubMed

    Iyer, Rupa; Smith, Kevin; Kudrle, Bill; Leon, Alex

    2015-06-25

    The Environmental Sampling Research Module (ESRM) is an investigative/discovery module that provides undergraduate research experiences for students as part of an interdisciplinary research-based biotechnology curriculum at the University of Houston campus. As part of the ESRM, students collect soil samples from various locations to test for the presence of organophosphorous (OP) degrading bacteria. At the end of this research project students submit a research paper on their field and laboratory activities and discuss their experimental data and observations. Students also record the date, location of collection, and the results of testing the sample for the degradation of two pesticides, methyl parathion or paraoxon, in an electronic laboratory notebook (ELN). Each collection site is recorded on a Google Maps module and the data from student research activities is made available to other undergraduate students. This data is then used to generate a microorganism database of pesticide degrading activity and promote reading, critical thinking, and analytical skills as part of the curriculum. Our sampling of agricultural sites and wastewater within and around the city of Houston has identified seven distinct genera of OP degrading organisms, including Pseudomonas, Stenotrophomonas, Exiguobacterium, Delftia, Agrobacterium, Aeromonas, and Rhizobium. Collected strains exhibit phosphotriesterase-like enzymatic activity with isolates of Pseudomonas putida and Stenotrophomonas maltophilia capable of degrading both the phosphotriester paraoxon and the phosphorothioate methyl parathion. Using this collection of OP-degrading microorganisms, undergraduate students have evaluated their potential for enhancing the removal of harmful organophosphates and their toxic metabolites from contaminated agricultural soil and adjacent bodies of water. This analytical data can potentially be utilized for environmental and industrial applications in bioremediation and ecology providing an innovative method for integrating education and research. In addition, the versatility of the ESRM itself provides for easy and rapid adaptation into varying environmental science courses with significant potential for the discovery and isolation of new and unique organisms to be used as part of ongoing research in the laboratory. PMID:25863354

  3. Isolation and characterization of polymeric galloyl-ester-degrading bacteria from a tannery discharge place.

    PubMed

    Franco, A R; Calheiros, C S C; Pacheco, C C; De Marco, P; Manaia, C M; Castro, P M L

    2005-11-01

    The culturable bacteria colonizing the rhizosphere of plants growing in the area of discharge of a tannery effluent were characterized. Relative proportions of aerobic, denitrifying, and sulfate-reducing bacteria were determined in the rhizosphere of Typha latifolia, Canna indica, and Phragmites australis. Aerobic bacteria were observed to be the most abundant group in the rhizosphere, and plant type did not seem to influence the abundance of the bacterial types analyzed. To isolate bacteria able to degrade polyphenols used in the tannery industry, enrichments were conducted under different conditions. Bacterial cultures were enriched with individual polyphenols (tannins Tara, Quebracho, or Mimosa) or with an undefined mixture of tannins present in the tannery effluent as carbon source. Cultures enriched with the effluent or Tara tannin were able to degrade tannic acid. Six bacterial isolates purified from these mixed cultures were able to use tannic acid as a sole carbon source in axenic culture. On the basis of 16S ribosomal DNA sequence analysis, these isolates were closely related to organisms belonging to the taxa Serratia, Stenotrophomonas maltophilia, Klebsiella oxytoca, Herbaspirillum chlorophenolicum, and Pseudomonas putida. PMID:16341641

  4. Biogenic selenium and tellurium nanoparticles synthesized by environmental microbial isolates efficaciously inhibit bacterial planktonic cultures and biofilms

    PubMed Central

    Zonaro, Emanuele; Lampis, Silvia; Turner, Raymond J.; Qazi, S. Junaid S.; Vallini, Giovanni

    2015-01-01

    The present study deals with Se0- and Te0-based nanoparticles bio-synthesized by two selenite- and tellurite-reducing bacterial strains, namely Stenotrophomonas maltophilia SeITE02 and Ochrobactrum sp. MPV1, isolated from polluted sites. We evidenced that, by regulating culture conditions and exposure time to the selenite and tellurite oxyanions, differently sized zero-valent Se and Te nanoparticles were produced. The results revealed that these Se0 and Te0 nanoparticles possess antimicrobial and biofilm eradication activity against Escherichia coli JM109, Pseudomonas aeruginosa PAO1, and Staphylococcus aureus ATCC 25923. In particular, Se0 nanoparticles exhibited antimicrobial activity at quite low concentrations, below that of selenite. Toxic effects of both Se0 and Te0 nanoparticles can be related to the production of reactive oxygen species upon exposure of the bacterial cultures. Evidence so far achieved suggests that the antimicrobial activity seems to be strictly linked to the dimensions of the nanoparticles: indeed, the highest activity was shown by nanoparticles of smaller sizes. In particular, it is worth noting how the bacteria tested in biofilm mode responded to the treatment by Se0 and Te0 nanoparticles with a susceptibility similar to that observed in planktonic cultures. This suggests a possible exploitation of both Se0 and Te0 nanoparticles as efficacious antimicrobial agents with a remarkable biofilm eradication capacity. PMID:26136728

  5. Counterion-activated nanoactuator: reversibly switchable killing/releasing bacteria on polycation brushes.

    PubMed

    Huang, Chun-Jen; Chen, Yen-Sheng; Chang, Yung

    2015-02-01

    A strategy to release attached bacteria from surface-grafted bactericidal poly((trimethylamino)ethyl methacrylate chloride) (pTMAEMA) brushes has been proposed. The pTMAEMA brushes were fabricated via the surface-initiated atom transfer radical polymerization for contact killing of bacteria, including Escherichia coli, Staphylococcus epidermidis and Stenotrophomonas maltophilia. The bacteria-conditioning surfaces, afterward, were washed with electrolyte solutions containing anions with different lipophilic characteristic, charge density, polarity and adsorbility to quaternary ammonium groups in polymers. Because of the special ion-pairing interactions, the interfacial properties, including wettability and ζ-potential, can be manipulated in a controlled manner. Therefore, the counterion-assisted modulation of pTMAEMA brushes facilitates the bacterial release and regeneration of antimicrobial polymer films. The physicochemical properties of polymer brushes and their interactions with counterions were characterized using an ellipsometer, contact angle goniometer, X-ray photoelectron spectroscopy and an electrokinetic analyzer. The repetitive killing and releasing actions of pTMAEMA through unlocking and locking counterions were demonstrated, showing the robust effectiveness of the pTMAEMA-based nanoactuator in controlling the physical action by the chemical stimuli. The real-world implementation of the nanoactuator was demonstrated with a surgical scalpel by repelling killed bacteria and retaining reusability. PMID:25608105

  6. Effect of carbon on whole-biofilm metabolic response to high doses of streptomycin

    PubMed Central

    Jackson, Lindsay M. D.; Kroukamp, Otini; Wolfaardt, Gideon M.

    2015-01-01

    Biofilms typically exist as complex communities comprising multiple species with the ability to adapt to a variety of harsh conditions. In clinical settings, antibiotic treatments based on planktonic susceptibility tests are often ineffective against biofilm infections. Using a CO2 evolution measurement system we delineated the real-time metabolic response in continuous flow biofilms to streptomycin doses much greater than their planktonic susceptibilities. Stable biofilms from a multispecies culture (containing mainly Pseudomonas aeruginosa and Stenotrophomonas maltophilia), Gram-negative environmental isolates, and biofilms formed by pure culture P. aeruginosa strains PAO1 and PAO1 ΔMexXY (minimum planktonic inhibitory concentrations between 1.5 and 3.5 mg/l), were exposed in separate experiments to 4000 mg/l streptomycin for 4 h after which growth medium resumed. In complex medium, early steady state multispecies biofilms were susceptible to streptomycin exposure, inferred by a cessation of CO2 production. However, multispecies biofilms survived high dose exposures when there was extra carbon in the antibiotic medium, or when they were grown in defined citrate medium. The environmental isolates and PAO1 biofilms showed similar metabolic profiles in response to streptomycin; ceasing CO2 production after initial exposure, with CO2 levels dropping toward baseline levels prior to recovery back to steady state levels, while subsequent antibiotic exposure elicited increased CO2 output. Monitoring biofilm metabolic response in real-time allowed exploration of conditions resulting in vulnerability after antibiotic exposure compared to the resistance displayed following subsequent exposures. PMID:26441887

  7. Capillary isoelectric focusing of proteins and microorganisms in dynamically modified fused silica with UV detection.

    PubMed

    Horká, Marie; Růzicka, Filip; Horký, Jaroslav; Holá, Veronika; Slais, Karel

    2006-09-01

    We suggest a method for the reproducible and efficient capillary isoelectric focusing of proteins and microorganisms in the pH gradient 3-10. The method involves the segmental injection of the simple ampholytes, the solution of the selected electrolytes, and the sample mixture of bioanalytes and carrier ampholytes to the fused silica capillaries dynamically modified by poly(ethylene glycol), PEG 4000, which is added to the catholyte, the anolyte and injected solutions. In order to receive the reproducible results, the capillaries were rinsed by the mixture of acetone/ethanol between analyses. For the tracing of the pH gradients the low-molecular-mass pI markers were used. The simple proteins and the mixed cultures of microorganisms, Saccharomyces cerevisiae CCM 8191, Escherichia coli CCM 3954, Candida albicans CCM 8180, Candida parapsilosis, Candida krusei, Staphylococcus aureus, Streptococcus agalactiae CCM 6187, Enterococcus faecalis CCM 4224, Staphylococcus epidermidis CCM 4418 and Stenotrophomonas maltophilia, were focused and separated by the method suggested. The minimum detectable number of microbial cells was 5x10(2) to 1x10(3) with on-column UV detection at 280 nm. PMID:16765111

  8. Antimicrobial Peptide Therapeutics for Cystic Fibrosis

    PubMed Central

    Zhang, Lijuan; Parente, Jody; Harris, Scott M.; Woods, Donald E.; Hancock, Robert E. W.; Falla, Timothy J.

    2005-01-01

    Greater than 90% of lung infections in cystic fibrosis (CF) patients are caused by Pseudomonas aeruginosa, and the majority of these patients subsequently die from lung damage. Current therapies are either targeted at reducing obstruction, reducing inflammation, or reducing infection. To identify potential therapeutic agents for the CF lung, 150 antimicrobial peptides consisting of three distinct structural classes were screened against mucoid and multidrug-resistant clinical isolates of P. aeruginosa, Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Staphylococcus aureus. Five peptides that retained potent antimicrobial activities in physiological salt and divalent cation environment were further characterized in vivo using a rat chronic lung infection model. All animals were inoculated intratracheally with 104 P. aeruginosa mucoid PAO1 cells in agar beads. Three days following inoculation treatment was initiated. Animals were treated daily for 3 days with 100 μl of peptide solution (1 mg/ml) in 10 mM sodium citrate, which was deposited via either intratracheal instillation or aerosolization. Control animals received daily exposure to vehicle alone. At the end of the treatment the lungs of the animals were removed for quantitative culture. Four peptides, HBCM2, HBCM3, HBCPα-2, and HB71, demonstrated significant reduction in Pseudomonas bioburden in the lung of rats. Further in vivo studies provided direct evidence that anti-inflammatory activity was associated with three of these peptides. Therefore, small bioactive peptides have the potential to attack two of the components responsible for the progression of lung damage in the CF disease: infection and inflammation. PMID:15980369

  9. Laboratory diagnosis, clinical management and infection control of the infections caused by extensively drug-resistant Gram-negative bacilli: a Chinese consensus statement.

    PubMed

    2016-03-01

    Extensively drug-resistant (XDR) Gram-negative bacilli (GNB) are defined as bacterial isolates susceptible to two or fewer antimicrobial categories. XDR-GNB mainly occur in Enterobacteriaceae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. The prevalence of XDR-GNB is on the rise in China and in other countries, and it poses a major public health threat as a result of the lack of adequate therapeutic options. A group of Chinese clinical experts, microbiologists and pharmacologists came together to discuss and draft a consensus on the laboratory diagnosis, clinical management and infection control of XDR-GNB infections. Lists of antimicrobial categories proposed for antimicrobial susceptibility testing were created according to documents from the Clinical Laboratory Standards Institute (CLSI), the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the United States Food and Drug Administration (FDA). Multiple risk factors of XDR-GNB infections are analyzed, with long-term exposure to extended-spectrum antimicrobials being the most important one. Combination therapeutic regimens are summarized for treatment of XDR-GNB infections caused by different bacteria based on limited clinical studies and/or laboratory data. Most frequently used antimicrobials used for the combination therapies include aminoglycosides, carbapenems, colistin, fosfomycin and tigecycline. Strict infection control measures including hand hygiene, contact isolation, active screening, environmental surface disinfections, decolonization and restrictive antibiotic stewardship are recommended to curb the XDR-GNB spread. PMID:26627340

  10. Pyrene removal and transformation by joint application of alfalfa and exogenous microorganisms and their influence on soil microbial community.

    PubMed

    Ye, Jinshao; Yin, Hua; Peng, Hui; Bai, Jieqiong; Li, Yuepeng

    2014-12-01

    Phytoremediation is an attractive approach for the cleanup of polycyclic aromatic hydrocarbons-contaminated soil. The joint effect of alfalfa and microorganisms, including Arthrobacter oxydans, Staphylococcus auricularis and Stenotrophomonas maltophilia, on pyrene removal was investigated. The results showed that the joint effect primarily contributed to pyrene removal, and the concentration of residual pyrene in rhizosphere soil was lower than that in non-rhizosphere soil. After joint treatment for 45d, pyrene in rhizosphere soils decreased from 11.3, 52.5 and 106.0mg/kg to 2.0-3.0, 15.0-18.7, and 41.2-44.8mg/kg, respectively. These bacteria significantly enhanced pyrene accumulation and microbial community diversity, and increased soil dehydrogenase and polyphenol oxidase activities. Pyrene was initially degraded through ring cleavage. One of the main metabolites 4-dihydroxy-phenanthrene was transformed into naphthol and 1,2-dihydroxynaphthalene, which were further degraded through salicylic acid pathway and phthalic acid pathway, separately. PMID:25232990

  11. Characteristics and consequences of airway colonization by filamentous fungi in 201 adult patients with cystic fibrosis in France.

    PubMed

    Paugam, André; Baixench, Marie-Thérèse; Demazes-Dufeu, Nadine; Burgel, Pierre-Régis; Sauter, Elise; Kanaan, Reem; Dusser, Daniel; Dupouy-Camet, Jean; Hubert, Dominique

    2010-11-01

    A total of 657 sputum samples from 201 cystic fibrosis adult patients were collected during a 24-month period (2005-2006). We retrospectively analyzed the fungal colonization of the respiratory tract of these individuals by linking medical records and microbiological data. Filamentous fungi were isolated from specimens of 65.6% of the patients, with Aspergillus fumigatus being the predominant species recovered as it was found in specimens of 56.7% of the patients. We observed no difference for gender, pancreatic status and cirrhosis in patients with or without A. fumigatus colonization. We found a higher percentage of recovery of Pseudomonas aeruginosa, Stenotrophomonas maltophilia and nontuberculous mycobacteria in patients with A. fumigatus colonization. During the follow-up period of the study, 8.9% of the patients were diagnosed with allergic bronchopulmonary aspergillosis (ABPA). By a multivariate analysis we demonstrated that Scedosporium apiospermum was significantly associated with ABPA (Odds ratio = 13 [2-80]) as opposed to A. fumigatus (Odds ratio = 1.58 [0.49-5.05]). PMID:21067327

  12. Diversity and Antimicrobial Properties of Lactic Acid Bacteria Isolated from Rhizosphere of Olive Trees and Desert Truffles of Tunisia

    PubMed Central

    Najjari, Afef; Turki, Yousra; Jaballah, Sana; Boudabous, Abdelatif; Ouzari, Hadda

    2013-01-01

    A total of 119 lactic acid bacteria (LAB) were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the genera Lactococcus, Pediococcus, Lactobacillus, Weissella, and Enterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while only 10% showed the ability to grow in 9% NaCl. In addition, a low rate of antibiotic resistance was detected among rhizospheric enterococci. Furthermore, a strong antibacterial activity against plant and/or pathogenic bacteria of Stenotrophomonas maltophilia, Pantoea agglomerans, Pseudomonas savastanoi, the food-borne Staphylococcus aureus, and Listeria monocytogenes was recorded. Antifungal activity evaluation showed that Botrytis cinerea was the most inhibited fungus followed by Penicillium expansum, Verticillium dahliae, and Aspergillus niger. Most of the active strains belonged to the genera Enterococcus and Weissella. This study led to suggest that environmental-derived LAB strains could be selected for technological application to control pathogenic bacteria and to protect food safety from postharvest deleterious microbiota. PMID:24151598

  13. Characterization of Contaminants from a Sanitized Milk Processing Plant

    PubMed Central

    Cleto, Sara; Matos, Sónia; Kluskens, Leon; Vieira, Maria João

    2012-01-01

    Milk processing lines offer a wide variety of microenvironments where a diversity of microorganisms can proliferate. We sampled crevices and junctions where, due to deficient reach by typical sanitizing procedures, bacteria can survive and establish biofilms. The sampling sites were the holding cell, cold storage tank, pasteurizer and storage tank - transfer pump junction. The culturable bacteria that were isolated after the sanitation procedure were predominantly Pseudomonas spp., Serratia spp, Staphylococcus sciuri and Stenotrophomonas maltophilia. We assayed several phenotypic characteristics such as the ability to secrete enzymes and siderophores, as well as the capacity of the strains to form biofilms that might contribute to their survival in a mixed species environment. The Pseudomonas spp. isolates were found to either produce proteases or lecithinases at high levels. Interestingly, protease production showed an inverse correlation with siderophore production. Furthermore, all of the Serratia spp. isolates were strong biofilm formers and spoilage enzymes producers. The organisms identified were not mere contaminants, but also producers of proteins with the potential to lower the quality and shelf-life of milk. In addition, we found that a considerable number of the Serratia and Pseudomonas spp. isolated from the pasteurizer were capable of secreting compounds with antimicrobial properties. PMID:22761957

  14. Home-use nebulizers: a potential primary source of Burkholderia cepacia and other colistin-resistant, gram-negative bacteria in patients with cystic fibrosis.

    PubMed Central

    Hutchinson, G R; Parker, S; Pryor, J A; Duncan-Skingle, F; Hoffman, P N; Hodson, M E; Kaufmann, M E; Pitt, T L

    1996-01-01

    Inhalation of aerosols contaminated with gram-negative bacteria generated from home-use nebulizers used by cystic fibrosis (CF) patients may be a primary route for bacterial colonization of the lung. Burkholderia cepacia was isolated from 3 of [corrected] 35 home-use nebulizers, and Stenotrophomonas maltophilia was isolated from 4 of 35 home-use nebulizers. Sputum cultures for two patients whose nebulizers were contaminated with B. cepacia did not yield the organism. However, DNA macrorestriction analysis by pulsed-field gel electrophoresis confirmed that one of two strains of B. cepacia recovered from the nebulizer of a third patient was also present in the sputum of that patient. Although Pseudomonas aeruginosa was isolated from 34 patients, none of the nebulizers were positive for the organism. Sixty-nine percent of nebulizers were contaminated, and up to 16 different environmental colistin-resistant, gram-negative species were identified. The heaviest contamination was found beneath the chamber atomizer. A questionnaire survey showed that the majority of patients (28 of 34) were receiving nebulized colistin and/or gentamicin. Patients who followed recommended instructions for good nebulizer hygienic practice and paid particular attention to drying had minimal or no contamination of their nebulizers. PMID:8904419

  15. Host-Defense Peptides with Therapeutic Potential from Skin Secretions of Frogs from the Family Pipidae

    PubMed Central

    Conlon, J. Michael; Mechkarska, Milena

    2014-01-01

    Skin secretions from frogs belonging to the genera Xenopus, Silurana, Hymenochirus, and Pseudhymenochirus in the family Pipidae are a rich source of host-defense peptides with varying degrees of antimicrobial activities and cytotoxicities to mammalian cells. Magainin, peptide glycine-leucine-amide (PGLa), caerulein-precursor fragment (CPF), and xenopsin-precursor fragment (XPF) peptides have been isolated from norepinephrine-stimulated skin secretions from several species of Xenopus and Silurana. Hymenochirins and pseudhymenochirins have been isolated from Hymenochirus boettgeri and Pseudhymenochirus merlini. A major obstacle to the development of these peptides as anti-infective agents is their hemolytic activities against human erythrocytes. Analogs of the magainins, CPF peptides and hymenochirin-1B with increased antimicrobial potencies and low cytotoxicities have been developed that are active (MIC < 5 μM) against multidrug-resistant clinical isolates of Staphylococcus aureus, Escherichia coli, Acinetobacter baumannii, Stenotrophomonas maltophilia and Klebsiella pneumoniae. Despite this, the therapeutic potential of frog skin peptides as anti-infective agents has not been realized so that alternative clinical applications as anti-cancer, anti-viral, anti-diabetic, or immunomodulatory drugs are being explored. PMID:24434793

  16. Anti-infective properties of epigallocatechin-3-gallate (EGCG), a component of green tea

    PubMed Central

    Steinmann, J; Buer, J; Pietschmann, T; Steinmann, E

    2013-01-01

    The consumption of green tea (Camellia sinensis) has been shown to have many physiological and pharmacological health benefits. In the past two decades several studies have reported that epigallocatechin-3-gallate (EGCG), the main constituent of green tea, has anti-infective properties. Antiviral activities of EGCG with different modes of action have been demonstrated on diverse families of viruses, such as Retroviridae, Orthomyxoviridae and Flaviviridae and include important human pathogens like human immunodeficiency virus, influenza A virus and the hepatitis C virus. Furthermore, the molecule interferes with the replication cycle of DNA viruses like hepatitis B virus, herpes simplex virus and adenovirus. Most of these studies demonstrated antiviral properties within physiological concentrations of EGCG in vitro. In contrast, the minimum inhibitory concentrations against bacteria were 10–100-fold higher. Nevertheless, the antibacterial effects of EGCG alone and in combination with different antibiotics have been intensively analysed against a number of bacteria including multidrug-resistant strains such as methicillin-resistant Staphylococcus aureus or Stenotrophomonas maltophilia. Furthermore, the catechin EGCG has antifungal activity against human-pathogenic yeasts like Candida albicans. Although the mechanistic effects of EGCG are not fully understood, there are results indicating that EGCG binds to lipid membranes and affects the folic acid metabolism of bacteria and fungi by inhibiting the cytoplasmic enzyme dihydrofolate reductase. This review summarizes the current knowledge and future perspectives on the antibacterial, antifungal and antiviral effects of the green tea constituent EGCG. PMID:23072320

  17. Bulgecin A: a novel inhibitor of binuclear metallo-beta-lactamases.

    PubMed

    Simm, Alan M; Loveridge, E Joel; Crosby, John; Avison, Matthew B; Walsh, Timothy R; Bennett, Peter M

    2005-05-01

    Bulgecin A, a sulphonated N-acetyl-D-glucosamine unit linked to a 4-hydroxy-5-hydroxymethylproline ring by a beta-glycosidic linkage, is a novel type of inhibitor for binuclear metallo-beta-lactamases. Using steady-state kinetic analysis with nitrocefin as the beta-lactam substrate, bulgecin A competitively inhibited the metallo-beta-lactamase BceII from Bacillus cereus in its two-zinc form, but failed to inhibit when the enzyme was in the single-zinc form. The competitive inhibition was restored by restoring the second zinc ion. The single-zinc metallo-beta-lactamase from Aeromonas veronii bv. sobria, ImiS, was not inhibited by bulgecin A. The tetrameric L1 metallo-beta-lactamase from Stenotrophomonas maltophilia was subject to partial non-competitive inhibition, which is consistent with a kinetic model in which the enzyme bound to inhibitor retains catalytic activity. Docking experiments support the conclusion that bulgecin A co-ordinates to the zinc II site in metallo-beta-lactamases via the terminal sulphonate group on the sugar moiety. PMID:15569001

  18. Significance and characterisation of pseudomonads from urinary tract specimens.

    PubMed

    Taneja, Neelam; Meharwal, S K; Sharma, S K; Sharma, Meera

    2004-03-01

    Pseudomonads are commonly encountered in clinical samples. Usually ignored as contaminants, these organisms are known to cause nosocomial opportunistic infections like urinary tract infections (UTI). One hundred and two pseudomonads obtained in pure culture and significant numbers from 8400 consecutive urinary tract (UT) specimens were biochemically characterised upto species level by a battery of biochemical tests. Modified Stoke's disk diffusion method was followed for testing antibiotic susceptibility. Beta-lactamase production was checked by nitrocefin disk method. Minimum Inhibitory Concentration for some of these strains against imipenem was done by agar dilution method of NCCLS. Etiological significance of isolating these organisms from UT specimens was also assessed. P. aeruginosa was the commonest (76) followed by B. pickettii (10), P. putida (6), P.fluorescence (2), P. stutzeri (20) P. vesicularis (2), S. putrefaciens (2) and Stenotrophomonas maltophilia (2). Seventy six per cent of P. aeruginosa produced beta-lactamases as compared to 45% of other pseudomonads. The frequency of antibiotic resistance was gentamicin and ciprofloxacin (68.6%) followed by netilmicin (60.7%), ceftazidime (58.8%), amikacin (43.1%) and piperacillin (39.2%). In 42 patients (51.2%) the etiological significance of isolating a pseudomonad could be confirmed. Risk factors for development of UTI were present in 62(75%). Obstructive uropathy (20) followed by post operative period and surgery on urinary tract were the commonest risk factors involved. A high level of resistance was observed for imipenem (P. aeruginosa 43.7% and other pseudomonads 25%). PMID:16295683

  19. Risk factors for hospital-acquired pneumonia caused by carbapenem-resistant Gram-negative bacteria in critically ill patients: a multicenter study in Korea.

    PubMed

    Kim, Tark; Chong, Yong Pil; Park, Seong Yeon; Jeon, Min-Hyok; Choo, Eun Joo; Chung, Jin-Won; Lee, Hyun Kyung; Moon, Chisook; Kim, Dong-Min; Peck, Kyong Ran; Kim, Yang Soo

    2014-04-01

    We performed a case-control study to identify risk factors of carbapenem-resistant Gram-negative bacteria (CRGNB) as an increasing cause of hospital-acquired pneumonia (HAP). The study included critically ill adult patients with HAP whose microbial etiology was identified at eight tertiary centers in Korea between June 2008 and December 2009. Eighty two patients with 86 isolates of CRGNB (62 Acinetobacter baumannii, 14 Pseudomonas aeruginosa, and 10 Stenotrophomonas maltophilia) were included in the case group, and 122 patients with carbapenem-susceptible Gram-negative bacteria were included in the control group. Diabetes mellitus (adjusted odds ratio [aOR] 2.82, 95% confidence interval [95% CI] 1.25-6.38), radiologic score ≥5 (aOR 4.56, 95% CI 2.36-8.81), prior fluoroquinolone (aOR 2.39. 95% CI = 1.07-5.35), or carbapenem usage (aOR 2.82, 95% CI 1.75-17.83) were found to be independent risk factors. Fluoroquinolone and carbapenem should be cautiously used to avoid HAP caused by CRGNB. PMID:24462178

  20. Effect of carbon on whole-biofilm metabolic response to high doses of streptomycin.

    PubMed

    Jackson, Lindsay M D; Kroukamp, Otini; Wolfaardt, Gideon M

    2015-01-01

    Biofilms typically exist as complex communities comprising multiple species with the ability to adapt to a variety of harsh conditions. In clinical settings, antibiotic treatments based on planktonic susceptibility tests are often ineffective against biofilm infections. Using a CO2 evolution measurement system we delineated the real-time metabolic response in continuous flow biofilms to streptomycin doses much greater than their planktonic susceptibilities. Stable biofilms from a multispecies culture (containing mainly Pseudomonas aeruginosa and Stenotrophomonas maltophilia), Gram-negative environmental isolates, and biofilms formed by pure culture P. aeruginosa strains PAO1 and PAO1 ΔMexXY (minimum planktonic inhibitory concentrations between 1.5 and 3.5 mg/l), were exposed in separate experiments to 4000 mg/l streptomycin for 4 h after which growth medium resumed. In complex medium, early steady state multispecies biofilms were susceptible to streptomycin exposure, inferred by a cessation of CO2 production. However, multispecies biofilms survived high dose exposures when there was extra carbon in the antibiotic medium, or when they were grown in defined citrate medium. The environmental isolates and PAO1 biofilms showed similar metabolic profiles in response to streptomycin; ceasing CO2 production after initial exposure, with CO2 levels dropping toward baseline levels prior to recovery back to steady state levels, while subsequent antibiotic exposure elicited increased CO2 output. Monitoring biofilm metabolic response in real-time allowed exploration of conditions resulting in vulnerability after antibiotic exposure compared to the resistance displayed following subsequent exposures. PMID:26441887

  1. Diaryl-substituted azolylthioacetamides: Inhibitor discovery of New Delhi metallo-β-lactamase-1 (NDM-1).

    PubMed

    Zhang, Yi-Lin; Yang, Ke-Wu; Zhou, Ya-Jun; LaCuran, Alecander E; Oelschlaeger, Peter; Crowder, Michael W

    2014-11-01

    The emergence and spread of antibiotic-resistant pathogens is a global public health problem. Metallo-β-lactamases (MβLs) such as New Delhi MβL-1 (NDM-1) are principle contributors to the emergence of resistance because of their ability to hydrolyze almost all known β-lactam antibiotics including penicillins, cephalosporins, and carbapenems. A clinical inhibitor of MBLs has not yet been found. In this study we developed eighteen new diaryl-substituted azolylthioacetamides and found all of them to be inhibitors of the MβL L1 from Stenotrophomonas maltophilia (Ki < 2 μM), thirteen to be mixed inhibitors of NDM-1 (Ki < 7 μM), and four to be broad-spectrum inhibitors of all four tested MβLs CcrA from Bacteroides fragilis, NDM-1 and ImiS from Aeromonas veronii, and L1 (Ki < 52 μM), which are representative of the B1a, B1b, B2, and B3 subclasses, respectively. Docking studies revealed that the azolylthioacetamides, which have the broadest inhibitory activity, coordinate to the Zn(II) ion(s) preferentially via the triazole moiety, while other moieties interact mostly with the conserved active site residues Lys224 (CcrA, NDM-1, and ImiS) or Ser221 (L1). PMID:25048031

  2. Microbial Surveillance of Potable Water Sources of the International Space Station

    NASA Technical Reports Server (NTRS)

    Bruce, Rebekah J.; Ott, C. Mark; Skuratov, Vladimir M.; Pierson, Duane L.

    2005-01-01

    To mitigate risk to the crew, the microbial surveillance of the quality of potable water sources of the International Space Station (ISS) has been ongoing since before the arrival of the first permanent crew. These water sources have included stored ground-supplied water, water produced by the shuttle fuel cells during flight, and ISS humidity condensate that is reclaimed and processed. Monitoring was accomplished using a self-contained filter designed to allow bacterial growth and enumeration during flight. Upon return to earth, microbial isolates were identified using 16S ribosomal gene sequencing. While the predominant isolates were common Gramnegative bacteria including Ralstonia eutropha, Methylobacterium fujisawaense, and Spingomonas paucimobilis, opportunistic pathogens such as Stenotrophomonas maltophilia and Pseudomonas aeruginosa were also isolated. Results of in-flight enumeration have indicated a fluctuation of bacterial counts above system design specifications. Additional in-flight monitoring capability for the specific detection of coliforms was added in 2004; no coliforms have been detected from any potable water source. Neither the bacterial concentrations nor the identification of the isolates recovered from these samples has suggested a threat to crew health.

  3. The role of wood-inhabiting bacteria in pine wilt disease

    PubMed Central

    Zhao, Bo Guang; Tao, Jian; Ju, Yun Wei; Wang, Peng Kai; Ye, Jian Ling

    2011-01-01

    The pathogenicity of the pine wood nematode (PWN), Bursaphelenchus xylophilus together with the bacteria isolated from black pine (Pinus thunbergii) bark inoculated to axenic black pine seedlings, significantly exceeded that of the axenic PWNs alone, demonstrating that the bacteria play an important role in pine wilt disease. Inoculation of seedlings with bacteria-free culture filtrates of the seven isolates from the dead seedlings from the above experiment showed that all isolate filtrates killed the seedlings within 8 days. Identification of the bacteria using 16S rDNA sequencing showed that the isolates belonged to strains By253Ydz-fq, S209, 210-50 and 210-50 in Bacillus and the DN1.1 strain of Stenotrophomonas maltophilia, respectively. Completing Koch’s postulates using the seven bacterial isolates to inoculate pine seedlings showed that all the seedlings that received aseptic PWNs mixed with the seven bacterial isolates died within 18 days post inoculation, while those inoculated with ‘wild’ PWNs died 16 days post inoculation. No disease symptoms developed on seedlings that received sterile water or aseptic PWNs. The horizontal transfer of the pathogenic bacteria may explain differences in bacterial species carried by PWN in different geographic areas. PMID:23430766

  4. The effect of different growth regimes on the endophytic bacterial communities of the fern, Dicksonia sellowiana hook (Dicksoniaceae)

    PubMed Central

    de Araújo Barros, Irene; Luiz Araújo, Welington; Lúcio Azevedo, João

    2010-01-01

    Endophytic bacteria associated with the fern Dicksonia sellowiana were investigated. The bacterial communities from the surface-sterilized pinnae and rachis segments of the plants from the Brazilian Atlantic Rainforest that grew in native field conditions were compared with the bacterial communities from plants grown in greenhouses and plants that were initially grown in greenhouses and then transferred to the forest. From 540 pinnae and 540 rachis segments, 163 (30.2%) and 346 (64.2%) were colonized by bacteria, respectively. The main bacterial genera and species that were isolated included Bacillus spp. ( B. cereus, B. megaterium, B. pumilus and B. subtilis ) , Paenibacillus sp. , Amphibacillus sp. , Gracilibacillus sp. , Micrococcus sp. and Stenotrophomonas spp. ( S. maltophilia and S. nitroreducens ). B. pumilus was the most frequently isolated bacterial species . Amphibacillus and Gracilibacillus were reported as endophytes for the first time. Other commonly found bacterial genera were not observed in D. sellowiana , which may reflect preferences of specific bacterial communities inside this fern or detection limitations due to the isolation procedures. Plants that were grown in greenhouses and plants that were reintroduced into the forest displayed more bacterial genera and species diversity than native field plants, suggesting that reintroduction shifts the bacterial diversity. Endophytic bacteria that displayed antagonistic properties against different microorganisms were detected, but no obvious correlation was found between their frequencies with plant tissues or with plants from different growth regimes. This paper reports the first isolation of endophytic bacteria from a fern. PMID:24031575

  5. Rosmarinic acid from eelgrass shows nematicidal and antibacterial activities against pine wood nematode and its carrying bacteria.

    PubMed

    Wang, Jingyu; Pan, Xueru; Han, Yi; Guo, Daosen; Guo, Qunqun; Li, Ronggui

    2012-12-01

    Pine wilt disease (PWD), a destructive disease for pine trees, is caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus and additional bacteria. In this study, extracts of Zostera marina showed a high nematicidal activity against PWN and some of the bacteria that it carries. Light yellow crystals were obtained from extracts of Z. marina through solvent extraction, followed by chromatography on AB-8 resin and crystallization. The NMR and HPLC analysis showed that the isolated compound was rosmarinic acid (RosA). RosA showed effective nematicidal activity, of which the LC₅₀ (50% lethal concentration) to PWN at 24 h, 48 h and 72 h was 1.18 mg/g, 1.05 mg/g and 0.95 mg/g, respectively. To get a high yield rate of RosA from Z. marina, single factor experiments and an L₉ (3⁴) orthogonal experiment were performed. This extraction process involved 70% ethanol for 3 h at 40 °C. The extraction dosage was 1:50 (w/v). The highest yield of RosA from Zostera was 3.13 mg/g DW (dried weight). The crude extracts of Zostera marina (10 mg/mL) and RosA (1 mg/mL) also showed inhibitory effects to some bacterial strains carried by PWN: Klebsiella sp., Stenotrophomonas maltophilia, Streptomyces sp. and Pantoea agglomerans. The results of these studies provide clues for preparing pesticide to control PWD from Z. marina. PMID:23201594

  6. Fournier's gangrene (necrotising fasciitis) complicated by renal and respiratory insufficiency: a case report.

    PubMed

    Frisman, E; Rácz, O; Beck, J; Firment, J; Bodnárová, L

    2016-01-01

    A case report of a 68-year-old male obese diabetic patient with an abscess of left femoral region, and diffuse inflammation of abdominal wall and genital region developing sepsis, respiratory and renal failure. At admission in the regional hospital a diagnosis of polymicrobial necrotising fasciitis with suspected sepsis was declared. The patient was transferred to the special intensive care unit (SICU) of Burns and reconstructive surgery at the Kosice-Saca. The patient was treated surgically, with hyperbaric oxygen and pharmacologically to control his diabetes. The main aetiological agent of the condition was identified as Stenotrophomonas maltophilia. In addition to respiratory and metabolic acidosis and gastric bleeding occurred. Due to acute renal failure (day 38) the patient was transferred to clinic of anaesthesiology and the intensive care medicine at the University Hospital in Kosice. The patient was treated by continuous veno-venous haemodialysis, mechanical ventilation and nasogastric nutritional support. On day 48 the conscious sub-febrile patient with healed wounds was transferred back to the regional hospital with ventilation support and continuous renal replacement therapy. His diabetes was uncontrolled, and only kidney parameters remained pathological. The survival of this patient with an extremely poor prognosis was achieved through prompt transfer to a specialised centre, early identification of the aetiological agent and immediate appropriate antibiotic treatment as a result of good cooperation between surgeons and laboratory specialists. PMID:26762496

  7. [The vacuum-assisted closure (V.A.C.) and instillation dressing: limb salvage after 3 degrees open fracture with massive bone and soft tissue defect and superinfection].

    PubMed

    Brem, M H; Blanke, M; Olk, A; Schmidt, J; Mueller, O; Hennig, F F; Gusinde, J

    2008-02-01

    We report the case of a 17-year-old boy who was hit by a high velocity train. The polytraumatized patient suffered a 3 degrees open femur defect fracture with a substantial loss of the lateral femoral muscles and significant disruption of the soft tissue of the lower leg. The enormous wound areas on the thigh and the lower leg were infected by Pseudomonas aeruginosa, Enterobacter cloacae, and Stenotrophomonas maltophilia. The enormous tissue defects and the superinfection did not leave any hope for saving the limb from amputation. After rapid aggressive debridement and pulsatile lavage, we covered the wounds as a last resort with a new technique of vacuum-assisted closure (V.A.C) and instillation (V.A.C. Instill(R)) dressings. In sequences of 1 min we instilled Lavasept, kept it for 20 min on the wound surface, and exhausted the liquid. We repeated this for 6 consecutive days and then changed the dressing. In the follow-up examinations the number of germs was significantly reduced. During follow-up care we used the V.A.C. treatment without instillation and finally we transplanted skin onto the clean wound surface and were able to save the leg of this young patient. We discharged him with a good function of his lower leg. This technique of V.A.C. Instill seems to offer great possibilities in critically infected wound situations. PMID:18219474

  8. Potency and Spectrum of Activity of AN3365, a Novel Boron-Containing Protein Synthesis Inhibitor, Tested against Clinical Isolates of Enterobacteriaceae and Nonfermentative Gram-Negative Bacilli

    PubMed Central

    Alley, M. R. K.; Sader, Helio S.; Biedenbach, Douglas J.; Jones, Ronald N.

    2013-01-01

    AN3365 (MIC50/90, 0.5/1 μg/ml) was active against Enterobacteriaceae, including a subset of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae strains (MIC50/90, 1/2 μg/ml). AN3365 inhibited 98.0 and 92.2% of wild-type (MIC50/90, 2/8 μg/ml) and carbapenem-resistant (MIC50/90, 4/8 μg/ml) Pseudomonas aeruginosa strains, respectively, at ≤8 μg/ml. AN3365 also demonstrated activity against wild-type Acinetobacter baumannii (MIC50/90, 2/8 μg/ml) and Stenotrophomonas maltophilia (MIC50/90, 2/4 μg/ml), while it was less active against multidrug-resistant A. baumannii (MIC50/90, 8/16 μg/ml) and Burkholderia cepacia (MIC50/90, 8/32 μg/ml). PMID:23507283

  9. Fluorescence Correlation Spectroscopy To Study Diffusion and Reaction of Bacteriophages inside Biofilms▿

    PubMed Central

    Briandet, R.; Lacroix-Gueu, P.; Renault, M.; Lecart, S.; Meylheuc, T.; Bidnenko, E.; Steenkeste, K.; Bellon-Fontaine, M.-N.; Fontaine-Aupart, M.-P.

    2008-01-01

    In the natural environment, most of the phages that target bacteria are thought to exist in biofilm ecosystems. The purpose of this study was to gain a clearer understanding of the reactivity of these viral particles when they come into contact with bacteria embedded in biofilms. Experimentally, we quantified lactococcal c2 phage diffusion and reaction through model biofilms using in situ fluorescence correlation spectroscopy with two-photon excitation. Correlation curves for fluorescently labeled c2 phage in nonreacting Stenotrophomonas maltophilia biofilms indicated that extracellular polymeric substances did not provide significant resistance to phage penetration and diffusion, even though penetration and diffusion were sometimes restricted because of the noncontractile tail of the viral particle. Fluctuations in the fluorescence intensity of the labeled phage were detected throughout the thickness of biofilms formed by c2-sensitive and c2-resistant strains of Lactococcus lactis but could never be correlated with time, revealing that the phage was immobile. This finding confirmed that recognition binding receptors for the viral particles were present on the resistant bacterial cell wall. Taken together, our results suggest that biofilms may act as “active” phage reservoirs that can entrap and amplify viral particles and protect them from harsh environments. PMID:18245240

  10. Antimicrobial multiresistance in bacteria isolated from freshwater Chilean salmon farms.

    PubMed

    Mirand, Claudio D; Zemelman, Raul

    2002-07-01

    The intensive use of antimicrobial agents, mainly oxytetracycline, to prevent and control bacterial pathologies in Chilean salmon culture is a frequent practice. A total of 103 gram-negative oxytetracycline-resistant bacteria recovered from various sources of 4 Chilean freshwater salmon farms were identified and investigated for their susceptibility patterns to various antibacterial agents, by using an agar disk diffusion method. Antibacterial resistance patterns of isolates were not correlated with bacterial species or strain source. A high number of bacteria resistant to amoxicillin, ampicillin. erythromycin, and furazolidone, as well as an important frequency of bacterial resistance to florfenicol, chloramphenicol, cefotaxime and trimethoprim-sulfamethoxazole was found. On the contrary, the proportion of bacteria resistant to gentamicin, kanamycin, flumequine and enrofloxacin was rather low. Resistant microflora showed a high taxonomic variability and mainly consisted of non-fermenting bacteria (77.7%). These strains mainly belonged to the species Pseudomonas fluorescens (29), Aeromonas hydrophila (10), Stenotrophomonas maltophilia (6), isolated from salmon fingerlings, and Acinetobacter lwoffii (5) isolated from pelletized feed. The occurrence of simultaneous resistance to various antibacterials was frequent. We observe a high frequency of bacteria resistant to 6-10 antibacterials (74 strains), and antibiotic resistance index (ARI) values ranging from 0.38 to 0.48 for the four salmon farms studied. These results suggest that Chilean salmon farms might play a role as reservoirs of antibacterial multiresistant bacteria, thus prompting the necessity for a more restrictive attitude towards the intensive use of antibacterials in salmon farming. PMID:12109474

  11. Antibacterial Spectrum of a Novel Des-Fluoro(6) Quinolone, BMS-284756

    PubMed Central

    Fung-Tomc, Joan C.; Minassian, Beatrice; Kolek, Benjamin; Huczko, Elizabeth; Aleksunes, Lauren; Stickle, Terry; Washo, Thomas; Gradelski, Elizabeth; Valera, Lourdes; Bonner, Daniel P.

    2000-01-01

    The in vitro spectrum of a novel des-fluoro(6) quinolone, BMS-284756, was compared with those of five fluoroquinolones (trovafloxacin, moxifloxacin, levofloxacin, ofloxacin, and ciprofloxacin). BMS-284756 was among the most active and often was the most active quinolone against staphylococci (including methicillin-resistant strains), streptococci, pneumococci (including ciprofloxacin-nonsusceptible and penicillin-resistant strains), and Enterococcus faecalis. BMS-284756 inhibited ≈60 to ≈70% of the Enterococcus faecium (including vancomycin-resistant) strains and 90 to 100% of the Enterobacteriaceae strains and gastroenteric bacillary pathogens at the anticipated MIC susceptible breakpoint (≤4 μg/ml). Against the nonfermenters, BMS-284756 inhibited 90 to 100% of Pseudomonas fluorescens, Pseudomonas stutzeri, Stenotrophomonas maltophilia, Flavobacterium spp., and Acinetobacter spp. and 72% of Pseudomonas aeruginosa strains at 4 μg/ml. Against anaerobic bacteria, BMS-284756 was among the most active, inhibiting essentially all strains tested. It had very low MICs against the fastidious and atypical microbial species, in particular against mycoplasmas or ureaplasmas, Borrelia burgdorferi, chlamydia, and gonococci. These results indicate that with its broad antibacterial spectrum, BMS-284756 should be evaluated clinically for the treatment of community and nosocomial infections. PMID:11083639

  12. The effect of different growth regimes on the endophytic bacterial communities of the fern, Dicksonia sellowiana hook (Dicksoniaceae).

    PubMed

    de Araújo Barros, Irene; Luiz Araújo, Welington; Lúcio Azevedo, João

    2010-10-01

    Endophytic bacteria associated with the fern Dicksonia sellowiana were investigated. The bacterial communities from the surface-sterilized pinnae and rachis segments of the plants from the Brazilian Atlantic Rainforest that grew in native field conditions were compared with the bacterial communities from plants grown in greenhouses and plants that were initially grown in greenhouses and then transferred to the forest. From 540 pinnae and 540 rachis segments, 163 (30.2%) and 346 (64.2%) were colonized by bacteria, respectively. The main bacterial genera and species that were isolated included Bacillus spp. ( B. cereus, B. megaterium, B. pumilus and B. subtilis ) , Paenibacillus sp. , Amphibacillus sp. , Gracilibacillus sp. , Micrococcus sp. and Stenotrophomonas spp. ( S. maltophilia and S. nitroreducens ). B. pumilus was the most frequently isolated bacterial species . Amphibacillus and Gracilibacillus were reported as endophytes for the first time. Other commonly found bacterial genera were not observed in D. sellowiana , which may reflect preferences of specific bacterial communities inside this fern or detection limitations due to the isolation procedures. Plants that were grown in greenhouses and plants that were reintroduced into the forest displayed more bacterial genera and species diversity than native field plants, suggesting that reintroduction shifts the bacterial diversity. Endophytic bacteria that displayed antagonistic properties against different microorganisms were detected, but no obvious correlation was found between their frequencies with plant tissues or with plants from different growth regimes. This paper reports the first isolation of endophytic bacteria from a fern. PMID:24031575

  13. Rosmarinic Acid from Eelgrass Shows Nematicidal and Antibacterial Activities against Pine Wood Nematode and Its Carrying Bacteria

    PubMed Central

    Wang, Jingyu; Pan, Xueru; Han, Yi; Guo, Daosen; Guo, Qunqun; Li, Ronggui

    2012-01-01

    Pine wilt disease (PWD), a destructive disease for pine trees, is caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus and additional bacteria. In this study, extracts of Zostera marina showed a high nematicidal activity against PWN and some of the bacteria that it carries. Light yellow crystals were obtained from extracts of Z. marina through solvent extraction, followed by chromatography on AB-8 resin and crystallization. The NMR and HPLC analysis showed that the isolated compound was rosmarinic acid (RosA). RosA showed effective nematicidal activity, of which the LC50 (50% lethal concentration) to PWN at 24 h, 48 h and 72 h was 1.18 mg/g, 1.05 mg/g and 0.95 mg/g, respectively. To get a high yield rate of RosA from Z. marina, single factor experiments and an L9 (34) orthogonal experiment were performed. This extraction process involved 70% ethanol for 3 h at 40 °C. The extraction dosage was 1:50 (w/v). The highest yield of RosA from Zostera was 3.13 mg/g DW (dried weight). The crude extracts of Zostera marina (10 mg/mL) and RosA (1 mg/mL) also showed inhibitory effects to some bacterial strains carried by PWN: Klebsiella sp., Stenotrophomonas maltophilia, Streptomyces sp. and Pantoea agglomerans. The results of these studies provide clues for preparing pesticide to control PWD from Z. marina. PMID:23201594

  14. Multi-Channel Microfluidic Biosensor Platform Applied for Online Monitoring and Screening of Biofilm Formation and Activity

    PubMed Central

    Bruchmann, Julia; Sachsenheimer, Kai; Rapp, Bastian E.; Schwartz, Thomas

    2015-01-01

    Bacterial colonization of surfaces and interfaces has a major impact on various areas including biotechnology, medicine, food industries, and water technologies. In most of these areas biofilm development has a strong impact on hygiene situations, product quality, and process efficacies. In consequence, biofilm manipulation and prevention is a fundamental issue to avoid adverse impacts. For such scenario online, non-destructive biofilm monitoring systems become important in many technical and industrial applications. This study reports such a system in form of a microfluidic sensor platform based on the combination of electrical impedance spectroscopy and amperometric current measurement, which allows sensitive online measurement of biofilm formation and activity. A total number of 12 parallel fluidic channels enable real-time online screening of various biofilms formed by different Pseudomonas aeruginosa and Stenotrophomonas maltophilia strains and complex mixed population biofilms. Experiments using disinfectant and antibiofilm reagents demonstrate that the biofilm sensor is able to discriminate between inactivation/killing of bacteria and destabilization of biofilm structures. The impedance and amperometric sensor data demonstrated the high dynamics of biofilms as a consequence of distinct responses to chemical treatment strategies. Gene expression of flagellar and fimbrial genes of biofilms grown inside the microfluidic system supported the detected biofilm growth kinetics. Thus, the presented biosensor platform is a qualified tool for assessing biofilm formation in specific environments and for evaluating the effectiveness of antibiofilm treatment strategies. PMID:25706987

  15. Biogenic selenium and tellurium nanoparticles synthesized by environmental microbial isolates efficaciously inhibit bacterial planktonic cultures and biofilms.

    PubMed

    Zonaro, Emanuele; Lampis, Silvia; Turner, Raymond J; Qazi, S Junaid S; Vallini, Giovanni

    2015-01-01

    The present study deals with Se(0)- and Te(0)-based nanoparticles bio-synthesized by two selenite- and tellurite-reducing bacterial strains, namely Stenotrophomonas maltophilia SeITE02 and Ochrobactrum sp. MPV1, isolated from polluted sites. We evidenced that, by regulating culture conditions and exposure time to the selenite and tellurite oxyanions, differently sized zero-valent Se and Te nanoparticles were produced. The results revealed that these Se(0) and Te(0) nanoparticles possess antimicrobial and biofilm eradication activity against Escherichia coli JM109, Pseudomonas aeruginosa PAO1, and Staphylococcus aureus ATCC 25923. In particular, Se(0) nanoparticles exhibited antimicrobial activity at quite low concentrations, below that of selenite. Toxic effects of both Se(0) and Te(0) nanoparticles can be related to the production of reactive oxygen species upon exposure of the bacterial cultures. Evidence so far achieved suggests that the antimicrobial activity seems to be strictly linked to the dimensions of the nanoparticles: indeed, the highest activity was shown by nanoparticles of smaller sizes. In particular, it is worth noting how the bacteria tested in biofilm mode responded to the treatment by Se(0) and Te(0) nanoparticles with a susceptibility similar to that observed in planktonic cultures. This suggests a possible exploitation of both Se(0) and Te(0) nanoparticles as efficacious antimicrobial agents with a remarkable biofilm eradication capacity. PMID:26136728

  16. Contribution of hot spring bacterial consortium in cadmium and lead bioremediation through quadratic programming model.

    PubMed

    Sen, Sudip Kumar; Raut, Sangeeta; Dora, Tapas Kumar; Mohapatra, Pradeep Kumar Das

    2014-01-30

    In the present investigation, a number of experiments have been conducted to isolate microbial strains from Taptapani Hot Spring Odisha, India for bioremediation of cadmium and lead. The strains Stenotrophomonas maltophilia (SS1), Aeromonas veronii (SS2) and Bacillus barbaricus (SS3) have shown better adaptation to metal tolerance test, with different concentrations of cadmium and lead and hence have been selected for further studies of metal microbial interaction and optimization. The results of bioremediation process indicate that consortium of thermophilic isolates adsorbed heavy metals more effectively than the individually treated isolates. Therefore, A 24 full factorial central composite design has been employed to analyze the effect of metal ion concentration, microbial concentration and time on removal of heavy metals with consortium. Analysis of variance (ANOVA) shows a high coefficient of determination value. The kinetic data have been fitted to pseudo-first order and second-order models. The isotherm equilibrium data have been well fitted by the Langmuir and Freundlich models. The optimum removal conditions determined for initial ion concentration was 0.3g/l; contact time 72h; microbial concentration, 3ml/l; and pH 7. At optimum adsorption conditions, the adsorption of cadmium and lead are found to be 92% and 93%, respectively, and presence of metals was confirmed through EDS analysis. PMID:24333714

  17. High-rate biological denitrification in the cyclic rotating-bed biological reactor: Effect of COD/NO3(-), nitrate concentration and salinity and the phylogenetic analysis of denitrifiers.

    PubMed

    Jafari, Seyed Javad; Moussavi, Gholamreza; Yaghmaeian, Kamyar

    2015-12-01

    The effects of COD/NO3(-) ratio, nitrate concentration and salinity was tested on the performance of the CRBR in denitrification with catechol as carbon source. The maximum nitrate reduction attained at COD/NO3(-) ratio of 1. The CRBR operated at optimum COD/NO3(-) ratio could completely denitrify the nitrate at inlet concentration up to 1250mg/L without nitrite accumulation. The maximum denitrification rate in the CRBR was 3.56kgNO3(-)/m(3)d with a nitrate reduction efficiency of 99% when the bioreactor was operated at inlet nitrate loading rate of 3.6kgNO3(-)/m(3)d. The denitrification performance of the CRBR was not affected significantly by NaCl concentrations up to 20g/L. 16S rRNA fragment and phylogenetic analysis identified Pseudomonas resinovorans, Stenotrophomonas maltophilia and Bacillus cereus as the most abundant denitrifiers in biomass. Accordingly, the CRBR is a high-rate bioreactor and appropriate technology for treatment of nitrate-laden industrial wastewaters containing phenolic compounds and salinity. PMID:26369277

  18. Fatty acid hydration activity of a recombinant Escherichia coli-based biocatalyst is improved through targeting the oleate hydratase into the periplasm.

    PubMed

    Jung, Sang-Min; Seo, Joo-Hyun; Lee, Jung-Hoo; Park, Jin-Byung; Seo, Jin-Ho

    2015-12-01

    Whole-cell biotransformation of fatty acids can be influenced by the activities of catalytic enzymes and by the efficiency of substrate transport into host cells. Here, we improved fatty acid hydration activity of the recombinant Escherichia coli expressing an oleate hydratase of Stenotrophomonas maltophilia by targeting the catalytic enzyme into the periplasm instead of the cytoplasm. Recombinant E. coli producing OhyA in the periplasm under guidance of the PelB signal sequence (E. coli OhyA_PP) exhibited significantly greater hydration activity with oleic acid and linoleic acid compared to a recombinant E. coli producing OhyA in the cytoplasm (E. coli OhyA_CS). For example, the oleate double bond hydration rate of E. coli OhyA_PP was >400 μmol/g dry cells/min (400 U/g dry cells), which is >10-fold higher than that of E. coli OhyA_CS. As the specific activities of the enzymes targeted into the cytoplasm and periplasm were comparable, we assumed that targeting OhyA into the periplasm could accelerate fatty acid transport to the catalytic enzymes by skipping the major mass transport barrier of the cytoplasmic membrane. Our results will contribute to the development of whole-cell biocatalysts for fatty acid biotransformation. PMID:26429801

  19. Antimicrobial peptide therapeutics for cystic fibrosis.

    PubMed

    Zhang, Lijuan; Parente, Jody; Harris, Scott M; Woods, Donald E; Hancock, Robert E W; Falla, Timothy J

    2005-07-01

    Greater than 90% of lung infections in cystic fibrosis (CF) patients are caused by Pseudomonas aeruginosa, and the majority of these patients subsequently die from lung damage. Current therapies are either targeted at reducing obstruction, reducing inflammation, or reducing infection. To identify potential therapeutic agents for the CF lung, 150 antimicrobial peptides consisting of three distinct structural classes were screened against mucoid and multidrug-resistant clinical isolates of P. aeruginosa, Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Staphylococcus aureus. Five peptides that retained potent antimicrobial activities in physiological salt and divalent cation environment were further characterized in vivo using a rat chronic lung infection model. All animals were inoculated intratracheally with 10(4) P. aeruginosa mucoid PAO1 cells in agar beads. Three days following inoculation treatment was initiated. Animals were treated daily for 3 days with 100 microl of peptide solution (1 mg/ml) in 10 mM sodium citrate, which was deposited via either intratracheal instillation or aerosolization. Control animals received daily exposure to vehicle alone. At the end of the treatment the lungs of the animals were removed for quantitative culture. Four peptides, HBCM2, HBCM3, HBCPalpha-2, and HB71, demonstrated significant reduction in Pseudomonas bioburden in the lung of rats. Further in vivo studies provided direct evidence that anti-inflammatory activity was associated with three of these peptides. Therefore, small bioactive peptides have the potential to attack two of the components responsible for the progression of lung damage in the CF disease: infection and inflammation. PMID:15980369

  20. Severe Bloodstream Infection due to KPC-Producer E coli in a Renal Transplant Recipient Treated With the Double-Carbapenem Regimen and Analysis of In Vitro Synergy Testing: A Case Report.

    PubMed

    Oliva, Alessandra; Cipolla, Alessia; Gizzi, Francesca; D'Abramo, Alessandra; Favaro, Marco; De Angelis, Massimiliano; Ferretti, Giancarlo; Russo, Gianluca; Iannetta, Marco; Mastroianni, Claudio M; Mascellino, Maria T; Vullo, Vincenzo

    2016-02-01

    Transplant recipients are at high risk of infections caused by multidrug resistant microorganisms. Due to the limited therapeutic options, innovative antimicrobial combinations against carbapenem-resistant Enterobacteriaceae causing severe infections are necessary.A 61-year-old woman with a history of congenital solitary kidney underwent renal transplantation. The postoperative course was complicated by nosocomial pneumonia due to Stenotrophomonas maltophilia and pan-sensitive Escherichia coli, successfully treated with antimicrobial therapy. On postoperative day 22, diagnosis of surgical site infection and nosocomial pneumonia with concomitant bacteremia due to a Klebisella pneumoniae carbapenemase-producer E coli was made. The patient was treated with the double-carbapenem regimen (high dose of meropenem plus ertapenem) and a potent synergistic and bactericidal activity of this un-conventional therapeutic strategy was observed in vitro. Despite a microbiological response with prompt negativity of blood cultures, the patient faced a worse outcome because of severe hemorrhagic shock.The double-carbapenem regimen might be considered as a rescue therapy in those subjects, including transplant recipients, in whom previous antimicrobial combinations failed or when colistin use might be discouraged. Performing in vitro synergy testing should be strongly encouraged in cases of infections caused by pan-drug resistant strains, especially in high-risk patients. PMID:26886594

  1. Reducing the development of antibiotic resistance in critical care units.

    PubMed

    Deege, Marjolein P D; Paterson, David L

    2011-12-01

    Bacteria becoming resistant to an increasing number of antibiotic classes are a major problem at hospitals including critical care units worldwide. Awareness of this problem and the need to prevent the development of antibiotic resistance are very important, especially since very few new antibiotics will become available in the near future. This article gives an overview of the mechanisms of antibacterial resistance and actual resistance data worldwide of the most prevalent Gram positive (MRSA, VISA/VRSE and VRE) and Gram negative bacteria (Pseudomonas aeruginosa, Acinetobacter spp., ESBL producing Enterobacteriaceae and Stenotrophomonas maltophilia). Furthermore, strategies to reduce antibiotic resistance are reviewed. Most important is institution of infection control policies including guidelines on surveillance, isolation of colonized patients and contact precautions, hand hygiene, decolonization measures and environmental decontamination. Antimicrobial stewardship, or striking the balance between an optimal antibiotic treatment for a patient and a minimal risk of development of antibiotic resistance, is another important strategy. Finally, optimizing of antibiotic dosage regimens and thus avoiding underdosage is essential to avoid selection of the most resistant subpopulation of bacteria during antibiotic treatment. Intensive care units with knowledge of local epidemiology of resistance, an effective infection control program and antimicrobial stewardship policy tailored to their specific needs, and using optimal antibiotic dosing regimens have both locally decreased the risk of an outbreak with multi-resistant bacteria, and maybe even more important help to reduce the development of antibiotic resistance. PMID:22188438

  2. Combination of photoreactor and packed bed bioreactor for the removal of ethyl violet from wastewater.

    PubMed

    Chen, Chih-Yu; Yen, Shao-Hsiung; Chung, Ying-Chien

    2014-12-01

    An efficient treatment system that combines a photoreactor and packed bed bioreactor (PBR) was developed and evaluated for treating ethyl violet (EV)-containing wastewater. Initial experiments demonstrated that the optimal operating parameters for the photoreactor in treating EV-containing wastewater were 2h reaction time, pH of 7, and 2 min liquid retention time. Under these conditions, the photocatalytic reaction achieved a 61% EV removal efficiency and resulted in a significant BOD/COD increase in the solution. The results displayed by the coupled photobiological system achieved a removal efficiency of 85% and EC50 of the solution increased by 19 times in a semi-continuous mode when the EV concentration was <150 mg +L(-)(1). The effect of shock loading on the EV removal was temporary but coexisting substrate (glucose and crystal violet) at specific levels would affect the EV removal efficiency of the PBR. Phylogenetic analysis in the PBR indicated that the major bacteria species were Bdellovibrio bacteriovorus, Ralstonia pickettii, Stenotrophomonas maltophilia, and Comamonas sp. Furthermore, the possible degrading mechanisms of this coupled system were demethylation, deethylation, aromatic ring opening, nitrification, and carbon oxidation. The intermediates were characterized using gas chromatography-mass spectrometry analysis. These results indicated that the coupled photobiological system provides an effective method of EV removal. PMID:25259784

  3. Bacteria from Ips sexdentatus (Coleoptera: Curculionidae) and their biocontrol potential.

    PubMed

    Sevim, Ali; Gökçe, Cihan; Erbaş, Zeynep; Ozkan, Filiz

    2012-12-01

    Ips sexdentatus (Coleoptera: Curculionidae) is one of the most destructive pests of the spruce trees in Europe. In this study, we have isolated and characterized culturable bacteria from I. sexdentatus and tested their insecticidal activity against the last instar larvae of the pest as a possible biocontrol agent. A total of eight bacterial isolates was determined and four of them were identified at species level, and the others were identified at genus level. Isolates were identified as Stenotrophomonas maltophilia (Is1), Rahnella sp. (Is2), Pseudomonas sp. (Is3), Bacillus sp. (Is4), Alcaligenes faecalis (Is5), Panteoea agglomerans (Is6), Pseudomonas fluorescens (Is7) and Serratia sp. (Is8) based on their morphological, biochemical and molecular characteristics. Insecticidal effects of bacterial isolates were performed on the last instar larvae of the pest. The highest insecticidal activity was obtained from P. fluorescens (Is7) with 73% mortality within 10 days after inoculation (p < 0.05). Mortality values of the other isolates ranged from 20 to 53%. This study suggests that Pseudomonas fluorescens (Is7) seems to be a good candidate as a possible biocontrol agent against I. sexdentatus, and provides suitable strains that can be modified to express insecticidal toxins and/or other detrimental substances to develop new control methods for I. sexdentatus. PMID:22581609

  4. In Vitro Activity of Telavancin in Combination with Colistin versus Gram-Negative Bacterial Pathogens

    PubMed Central

    Hornsey, Michael; Longshaw, Christopher; Phee, Lynette

    2012-01-01

    The treatment of Gram-negative infections is increasingly compromised by the spread of resistance. With few agents currently in development, clinicians are now considering the use of unorthodox combination therapies for multidrug-resistant strains. Here we assessed the in vitro activity of the novel lipoglycopeptide telavancin (TLV) when combined with colistin (COL) versus 13 Gram-negative type strains and 66 clinical isolates. Marked synergy was observed in either checkerboard (fractional inhibitory concentration index [FICI], <0.5; susceptibility breakpoint index [SBPI], >2) or time-kill assays (>2-log reduction in viable counts compared with starting inocula at 24 h) versus the majority of COL-susceptible enterobacteria, Stenotrophomonas maltophilia, and Acinetobacter baumannii isolates, but only limited effects were seen against Pseudomonas aeruginosa or strains with COL resistance. Using an Etest/agar dilution method, the activity of TLV was potentiated by relatively low concentrations of COL (0.25 to 0.75 μg/ml), reducing the MIC of TLV from >32 μg/ml to ≤1 μg/ml for 35% of the clinical isolates. This provides further evidence that glycopeptide-polymyxin combinations may be a useful therapeutic option in the treatment of Gram-negative infections. PMID:22491686

  5. Production and characterization of monoclonal antibodies specific for the lipopolysaccharide of Escherichia coli O157.

    PubMed Central

    Westerman, R B; He, Y; Keen, J E; Littledike, E T; Kwang, J

    1997-01-01

    Identification of the O157 antigen is an essential part of the detection of Escherichia coli O157:H7, which is recognized as a major etiologic agent of hemorrhagic colitis. However, polyclonal antibodies produced against E. coli O157:H7 lipopolysaccharide (LPS) may react with several other bacteria including Brucella abortus, Brucella melitensis, Yersinia enterocolitica O9, Escherichia hermannii, and Stenotrophomonas maltophilia. We produced eight monoclonal antibodies (MAbs) specific for the LPS of E. coli O157. Western blots (immunoblots) of both the phenol phase (smooth) and the aqueous phase (rough) of hot phenol-water-purified LPS indicated that three of the MAbs were specific for the O antigen and five were reactive with the LPS core. The eight MAbs could be further differentiated by their reactivities to Salmonella O30 LPS (group N), which is reported to be identical to the E. coli O157 antigen. All eight MAbs reacted strongly to all of the 64 strains of E. coli O157 tested, which included 47 isolates of O157:H7 and 17 other O157 strains. None of the eight MAbs cross-reacted with any of the 38 other E. coli serotypes tested, which consisted of 29 different O-antigen serotypes, or with 38 strains (22 genera) of non-E. coli gram-negative enteric bacteria. PMID:9041412

  6. Characterizing Novel Thermophilic Amylase Producing Bacteria From Taptapani Hot Spring, Odisha, India

    PubMed Central

    Sen, Sudip Kumar; Raut, Sangeeta; Satpathy, Soumya; Rout, Prangya Ranjan; Bandyopadhyay, Bidyut; Das Mohapatra, Pradeep Kumar

    2014-01-01

    Background: Amylases play a vital role in biotechnological studies and rank an important position in the world enzyme market (25% to 33%). Bioprocess method of amylase production is more effective than the other sources, since the technique is easy, cost effective, fast, and the enzymes of required properties can be procured. Objectives: The current study aimed to report the characteristics of novel amylase producing bacterial strains isolated from Taptapani hot spring, Odisha, India. Materials and Methods: Bacterial strains were isolated by dilution plating method from the water samples collected from Taptapani Hot Spring, Odisha and screened for amylase production through starch hydrolysis. The bacterial isolates were identified morphologically, biochemically, and finally by 16S rDNA profiling. Results: Based on the morphological, physiological, biochemical characteristics and the molecular characterization, the isolates SS1, SS2, and SS3 were identified as Bacillus barbaricus, Aeromonas veroni, and Stenotrophomonas maltophilia, respectively. The approximate molecular weight of enzymes from SS1, SS2, and SS3 strains were 19 kDa, 56 kDa and 49 kDa, respectively. Conclusions: The current report isolates, characterizes, and demonstrates the novel heat-adapted amylase-producing bacteria SS1, SS2 and SS3 from Taptapani hot spring, indicating its potentiality and stability under acidic conditions. PMID:25741425

  7. In vitro activity of telavancin in combination with colistin versus Gram-negative bacterial pathogens.

    PubMed

    Hornsey, Michael; Longshaw, Christopher; Phee, Lynette; Wareham, David W

    2012-06-01

    The treatment of Gram-negative infections is increasingly compromised by the spread of resistance. With few agents currently in development, clinicians are now considering the use of unorthodox combination therapies for multidrug-resistant strains. Here we assessed the in vitro activity of the novel lipoglycopeptide telavancin (TLV) when combined with colistin (COL) versus 13 Gram-negative type strains and 66 clinical isolates. Marked synergy was observed in either checkerboard (fractional inhibitory concentration index [FICI], <0.5; susceptibility breakpoint index [SBPI], >2) or time-kill assays (>2-log reduction in viable counts compared with starting inocula at 24 h) versus the majority of COL-susceptible enterobacteria, Stenotrophomonas maltophilia, and Acinetobacter baumannii isolates, but only limited effects were seen against Pseudomonas aeruginosa or strains with COL resistance. Using an Etest/agar dilution method, the activity of TLV was potentiated by relatively low concentrations of COL (0.25 to 0.75 μg/ml), reducing the MIC of TLV from >32 μg/ml to ≤ 1 μg/ml for 35% of the clinical isolates. This provides further evidence that glycopeptide-polymyxin combinations may be a useful therapeutic option in the treatment of Gram-negative infections. PMID:22491686

  8. Antibiotic Resistance and Extended-Spectrum β-Lactamases in Isolated Bacteria from Seawater of Algiers Beaches (Algeria)

    PubMed Central

    Alouache, Souhila; Kada, Mohamed; Messai, Yamina; Estepa, Vanesa; Torres, Carmen; Bakour, Rabah

    2012-01-01

    The aim of the study was to evaluate bacterial antibiotic resistance in seawater from four beaches in Algiers. The most significant resistance rates were observed for amoxicillin and ticarcillin, whereas they were relatively low for ceftazidime, cefotaxime and imipenem. According to sampling sites, the highest resistance rates were recorded for 2 sites subjected to chemical and microbiological inputs (amoxicillin, 43% and 52%; ticarcillin, 19.6% and 47.7%), and for 2 sites relatively preserved from anthropogenic influence, resistance rates were lowest (amoxicillin, 1.5% and 16%; ticarcillin, 0.8% and 2.6%). Thirty-four bacteria resistant to imipenem (n=14) or cefotaxime (n=20) were identified as Pseudomonas aeruginosa (n=15), Pseudomonas fluorescens(7), Stenotrophomonas maltophilia(4), Burkholderia cepacia(2), Bordetella sp. (1), Pantoea sp. (1), Acinetobacter baumannii(1), Chryseomonas luteola(1), Ochrobactrum anthropi(1) and Escherichia coli(1). Screening for extended spectrum β-lactamase showed the presence of CTX-M-15 β-lactamase in the E. coli isolate, and the encoding gene was transferable in association with the IncI1 plasmid of about 50 kbp. Insertion sequence ISEcp1B was located upstream of the CTX-M-15 gene. This work showed a significant level of resistance to antibiotics, mainly among environmental saprophytic bacteria. Transmissible CTX-M-15 was detected in E. coli; this may mean that contamination of the environment by resistant bacteria may cause the spread of resistance genes. PMID:22095134

  9. Efficacy of an anaerobic swab transport system to maintain aerobic and anaerobic microorganism viability after storage at -80 degrees C.

    PubMed

    Musser, Jeffrey M B; Gonzalez, Rosa

    2011-01-01

    An Amies agar gel swab transport system was evaluated for its ability to maintain bacterial viability and relative quantity after freezing at -80°C. Nine American Type Culture Collection (ATCC) bacterial strains were used: 3 anaerobic strains (Propionibacterium acnes, Peptostreptococcus anaerobius, and Clostridium sporogenes) and 6 facultative or strict aerobic bacterial strains (Stenotrophomonas maltophilia, Escherichia coli ([ATCC 25922 and ATCC 11775], Salmonella enterica subsp. enterica serovar Typhimurium, Staphylococcus saprophyticus, and Lactobacillus casei). The bacterial species were chosen because they corresponded to bacteria identified in psittacine feces and cloacal samples. There were no significant differences between growth scores at baseline and after storage at -80°C for 40 days for any of the bacteria examined after 48 and 72 hr of incubation, with the exception of P. anaerobius. For P. anaerobius, there was a significant reduction (P < 0.001) in the growth score after storage at -80°C for 40 days from that of the baseline; however, the bacteria were still viable. The tested swab transport system may be useful when lengthy storage and transport times necessitate freezing samples prior to culture. PMID:21217035

  10. Hospital infestation by the cluster fly, Pollenia rudis sensu stricto Fabricius 1794 (Diptera: Calliphoridae), and its possible role in transmission of bacterial pathogens in Germany.

    PubMed

    Faulde, M; Sobe, D; Burghardt, H; Wermter, R

    2001-03-01

    The potential of the cluster fly, Pollenia rudis sensu stricto, to transmit bacterial pathogens was investigated during a mass infestation that took place in a German hospital. Cluster flies were individually examined for mesophilic bacteria carried on the exoskeleton. Bacterial growth could only be detected by using the enrichment culture technique to increase sensitivity, but not by direct intoculation of fly samples to agar plates. All 50 cluster fly samples that were tested carried opportunistic aerobic mesophilic Bacillus spp., whereas 41 fly samples were positive for Erwinia spp., 16 samples for Erwinia amylovara, 24 samples for Stenotrophomonas maltophilia, and 4 samples for Flavobacterium odoratum. Staphylococcus lugdunensis and Pseudomonas aeruginosa were found in 5 samples. No bacteriologically sterile cluster fly samples were obtained. The whole bacterial pattern found on P. rudis s. s. is known for its potential to cause opportunistic and/or nosocomial infections in humans. The results obtained led to the assumption that mass infestations of cluster flies occurring in sensitive areas, especially in hospitals, may cause a low, but not neglectable health threat due to mechanical transmission of bacterial pathogens. PMID:11279815

  11. Bacterial bioeffectors modify bioactive profile and increase isoflavone content in soybean sprouts (Glycine max var Osumi).

    PubMed

    Algar, Elena; Ramos-Solano, Beatriz; García-Villaraco, Ana; Sierra, M Dolores Saco; Gómez, M Soledad Martín; Gutiérrez-Mañero, F Javier

    2013-09-01

    The effect of two bacterial strains to enhance bioactive contents (total phenolic compounds, total flavonoid compounds and isoflavones) and antioxidant activity on 3-day-old soybean sprouts were investigated. To identify bacterial determinants responsible for these effects, viable and UV-treated strains were delivered to wounded seeds at different concentration. Multivariate analysis performed with all the evaluated parameters indicated the different effectiveness of Stenotrophomonas maltophilia N5.18 and Pseudomonas fluorescens N21.4 based on different structural and metabolic determinants for each. N21.4 increased total phenolics and isoflavones from the genistein family, while N5.18 triggered biosynthesis of daidzein and genistein families coupled to a decrease in total phenolics, suggesting different molecular targets in the phenilpropanoid pathway. Only extracts from N5.18 treated seeds showed an improved antioxidant activity according to the β-carotene bleaching prevention method. In summary, bioeffectors from both bacterial strains are effective tools to improve soybean sprouts quality; structural elicitors from N5.18 also enhanced antioxidant activity, being the best alternative for further development of a biotechnological procedure. PMID:23918406

  12. The Disinfecting Potential of Contact Lens Soutions used by Sultan Qaboos University Students

    PubMed Central

    Nzeako, B. C.; Al-Sumri, Sara H.

    2011-01-01

    Objectives: This study aimed to determine the disinfecting potential of some contact lens solutions used by some university students in Oman. Methods: This work was carried out from January to June 2010 in the Department of Microbiology & Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Oman. Fifty disinfecting solutions, in which contact lenses were disinfected according to the manufacturers’ instructions, were collected from the students and plated on various microbiological culture media. Bacterial isolates were identified by API-20E, API-20NE and Phoenix automated systems while fungi were identified by their cultural characteristics and biochemistry. Results: From 98 isolates, Pseudomonas aeruginosa was 23.5%; Penicillium, 13%; Candida species, 9.2%; coagulase negative staphylococci, 9.2%; Serratia marcescens, 6.1%; Bacillus, 5.1%; Aspergillus flavus, 5.1%; Serratia liquefaciens, Pseudomonas fluorescens, Enterobacter cloacae and Aspergillus niger, 4.1% each; Chryseomonas luteola and Chryseomonas indologenes, 3.1% each; Stenotrophomonas maltophilia, Serratia odorifera, 2.0% each; Enterobacter aerogenes and Klebsiella pneumoniae, 1% each. Most isolates (65%) came from polyhexanide containing solutions. Conclusion: Contact lens disinfecting solutions with the same formulations, but manufactured by different companies, possessed different disinfecting potentials. PMID:21969898

  13. Prevalence of antibiotic-resistant bacteria in herbal products.

    PubMed

    Brown, Joseph C; Jiang, Xiuping

    2008-07-01

    The objective of this study was to determine the prevalence of antibiotic-resistant bacteria in various herbal products. Twenty-nine herbal supplements (18 traditional and 11 organic products) were purchased from stores and analyzed microbiologically. Total bacterial counts were determined by pour plate and surface spreading on tryptic soy agar (TSA). Antibiotic-resistant bacteria were enumerated on TSA supplemented with ceftriaxone (64 microg/ml) or tetracycline (16 microg/ml). Total bacterial counts ranged from <5 to 2.9 x 10(5) CFU/g. Ceftriaxone- and tetracycline-resistant bacteria were detected in ground garlic samples at 1.1 x 10(2) CFU/g and 3.0 x 102 CFU/g, respectively. Traditional and organic onion powder samples contained tetracycline-resistant bacteria at 17 and 28 CFU/g and ceftriaxone-resistant bacteria at 35 and 2.0 x 10(3) CFU/g, respectively. Other products such as ginger, rosemary, mustard, and goldenseal contained low levels of resistant bacteria. Fifty-two isolates were further evaluated against nine antibiotics, and the prevalence of antibiotic resistance was in the following order: ampicillin, nalidixic acid, trimethoprim, ceftriaxone, and streptomycin. Resistant bacteria were identified as Bacillus spp., Erwinia spp., and Ewingella americana. Staphylococcus spp., Enterobacter cloacae, and Stenotrophomonas maltophilia also were isolated. The presence of antibiotic-resistant bacteria and pathogens in these herbal products suggests that production and use of these products may need further evaluation. PMID:18680952

  14. Degradation and Mineralization of High-Molecular-Weight Polycyclic Aromatic Hydrocarbons by Defined Fungal-Bacterial Cocultures

    PubMed Central

    Boonchan, Sudarat; Britz, Margaret L.; Stanley, Grant A.

    2000-01-01

    This study investigated the biodegradation of high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) in liquid media and soil by bacteria (Stenotrophomonas maltophilia VUN 10,010 and bacterial consortium VUN 10,009) and a fungus (Penicillium janthinellum VUO 10,201) that were isolated from separate creosote- and manufactured-gas plant-contaminated soils. The bacteria could use pyrene as their sole carbon and energy source in a basal salts medium (BSM) and mineralized significant amounts of benzo[a]pyrene cometabolically when pyrene was also present in BSM. P. janthinellum VUO 10,201 could not utilize any high-molecular-weight PAH as sole carbon and energy source but could partially degrade these if cultured in a nutrient broth. Although small amounts of chrysene, benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene were degraded by axenic cultures of these isolates in BSM containing a single PAH, such conditions did not support significant microbial growth or PAH mineralization. However, significant degradation of, and microbial growth on, pyrene, chrysene, benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene, each as a single PAH in BSM, occurred when P. janthinellum VUO 10,201 and either bacterial consortium VUN 10,009 or S. maltophilia VUN 10,010 were combined in the one culture, i.e., fungal-bacterial cocultures: 25% of the benzo[a]pyrene was mineralized to CO2 by these cocultures over 49 days, accompanied by transient accumulation and disappearance of intermediates detected by high-pressure liquid chromatography. Inoculation of fungal-bacterial cocultures into PAH-contaminated soil resulted in significantly improved degradation of high-molecular-weight PAHs, benzo[a]pyrene mineralization (53% of added [14C]benzo[a]pyrene was recovered as 14CO2 in 100 days), and reduction in the mutagenicity of organic soil extracts, compared with the indigenous microbes and soil amended with only axenic inocula. PMID:10698765

  15. Specific and Functional Diversity of Endophytic Bacteria from Pine Wood Nematode Bursaphelenchus Xylophilus with Different Virulence

    PubMed Central

    Wu, Xiao-Qin; Yuan, Wei-Min; Tian, Xiao-Jing; Fan, Ben; Fang, Xin; Ye, Jian-Ren; Ding, Xiao-Lei

    2013-01-01

    Pine wilt disease (PWD) caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus, is one of the most devastating diseases of Pinus spp. The PWN was therefore listed as one of the most dangerous forest pests in China meriting quarantine. Virulence of the PWN is closely linked with the spread of PWD. However, main factors responsible for the virulence of PWNs are still unclear. Recently epiphytic bacteria carried by PWNs have drawn much attention. But little is known about the relationship between endophytic bacteria and virulence of B. xylophilus. In this research, virulence of ten strains of B. xylophilus from different geographical areas in six provinces of China and four pine species were tested with 2-year-old seedlings of Pinus thunbergii. Endophytic bacteria were isolated from PWNs with different virulence to investigate the relationship between the bacteria and PWN virulence. Meanwhile, the carbon metabolism of endophytic bacteria from highly and low virulent B. xylophilus was analyzed using Biolog plates (ECO). The results indicated that ten strains of PWNs showed a wide range of virulence. Simultaneously, endophytic bacteria were isolated from 90% of the B. xylophilus strains. The dominant endophytic bacteria in the nematodes were identified as species of Stenotrophomonas, Achromobacter, Ewingella, Leifsonia, Rhizobium, and Pseudomonas using molecular and biochemical methods. Moreover, S. maltophilia, and A. xylosoxidans subsp. xylosoxidans were the predominant strains. Most of the strains (80%) from P. massoniana contained either S. maltophilia, A. xylosoxidans, or both species. There was a difference between the abilities of the endophytic bacteria to utilize carbon sources. Endophytic bacteria from highly virulent B. xylophilus had a relatively high utilization rate of carbohydrate and carboxylic acids, while bacteria from low virulent B. xylophilus made better use of amino acids. In conclusion, endophytic bacteria widely exist in B. xylophilus from different pines and areas; and B. xylophilus strains with different virulence possessed various endophytic bacteria and diverse carbon metabolism which suggested that the endophytic bacteria species and carbon metabolism might be related with the B. xylophilus virulence. PMID:23289015

  16. Specific and functional diversity of endophytic bacteria from pine wood nematode Bursaphelenchus xylophilus with different virulence.

    PubMed

    Wu, Xiao-Qin; Yuan, Wei-Min; Tian, Xiao-Jing; Fan, Ben; Fang, Xin; Ye, Jian-Ren; Ding, Xiao-Lei

    2013-01-01

    Pine wilt disease (PWD) caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus, is one of the most devastating diseases of Pinus spp. The PWN was therefore listed as one of the most dangerous forest pests in China meriting quarantine. Virulence of the PWN is closely linked with the spread of PWD. However, main factors responsible for the virulence of PWNs are still unclear. Recently epiphytic bacteria carried by PWNs have drawn much attention. But little is known about the relationship between endophytic bacteria and virulence of B. xylophilus. In this research, virulence of ten strains of B. xylophilus from different geographical areas in six provinces of China and four pine species were tested with 2-year-old seedlings of Pinus thunbergii. Endophytic bacteria were isolated from PWNs with different virulence to investigate the relationship between the bacteria and PWN virulence. Meanwhile, the carbon metabolism of endophytic bacteria from highly and low virulent B. xylophilus was analyzed using Biolog plates (ECO). The results indicated that ten strains of PWNs showed a wide range of virulence. Simultaneously, endophytic bacteria were isolated from 90% of the B. xylophilus strains. The dominant endophytic bacteria in the nematodes were identified as species of Stenotrophomonas, Achromobacter, Ewingella, Leifsonia, Rhizobium, and Pseudomonas using molecular and biochemical methods. Moreover, S. maltophilia, and A. xylosoxidans subsp. xylosoxidans were the predominant strains. Most of the strains (80%) from P. massoniana contained either S. maltophilia, A. xylosoxidans, or both species. There was a difference between the abilities of the endophytic bacteria to utilize carbon sources. Endophytic bacteria from highly virulent B. xylophilus had a relatively high utilization rate of carbohydrate and carboxylic acids, while bacteria from low virulent B. xylophilus made better use of amino acids. In conclusion, endophytic bacteria widely exist in B. xylophilus from different pines and areas; and B. xylophilus strains with different virulence possessed various endophytic bacteria and diverse carbon metabolism which suggested that the endophytic bacteria species and carbon metabolism might be related with the B. xylophilus virulence. PMID:23289015

  17. A novel salt-tolerant chitobiosidase discovered by genetic screening of a metagenomic library derived from chitin-amended agricultural soil.

    PubMed

    Cretoiu, Mariana Silvia; Berini, Francesca; Kielak, Anna Maria; Marinelli, Flavia; van Elsas, Jan Dirk

    2015-10-01

    Here, we report on the construction of a metagenomic library from a chitin-amended disease-suppressive agricultural soil and its screening for genes that encode novel chitinolytic enzymes. The library, constructed in fosmids in an Escherichia coli host, comprised 145,000 clones containing inserts of sizes of 21 to 40 kb, yielding a total of approximately 5.8 GB of cloned soil DNA. Using genetic screenings by repeated PCR cycles aimed to detect gene sequences of the bacterial chitinase A-class (hereby named chi A genes), we identified and characterized five fosmids carrying candidate genes for chitinolytic enzymes. The analysis thus allowed access to the genomic (fosmid-borne) context of these genes. Using the chiA-targeted PCR, which is based on degenerate primers, the five fosmids all produced amplicons, of which the sequences were related to predicted chitinolytic enzyme-encoding genes of four different host organisms, including Stenotrophomonas maltophilia. Sequencing and de novo annotation of the fosmid inserts confirmed that each one of these carried one or more open reading frames that were predicted to encode enzymes active on chitin, including one for a chitin deacetylase. Moreover, the genetic contexts in which the putative chitinolytic enzyme-encoding genes were located were unique per fosmid. Specifically, inserts from organisms related to Burkholderia sp., Acidobacterium sp., Aeromonas veronii, and the chloroflexi Nitrolancetus hollandicus and/or Ktedonobacter racemifer were obtained. Remarkably, the S. maltophilia chiA-like gene was found to occur in two different genetic contexts (related to N. hollandicus/K. racemifer), indicating the historical occurrence of genetic reshufflings in this part of the soil microbiota. One fosmid containing the insert composed of DNA from the N. hollandicus-like organism (denoted 53D1) was selected for further work. Using subcloning procedures, its putative gene for a chitinolytic enzyme was successfully brought to expression in an E. coli host. On the basis of purified protein preparations, the produced protein was characterized as a chitobiosidase of 43.6 kDa, with a pI of 4.83. Given its activity spectrum, it can be typified as a halotolerant chitobiosidase. PMID:26040993

  18. Assessment of the Microbial Constituents of the Home Environment of Individuals with Cystic Fibrosis (CF) and Their Association with Lower Airways Infections

    PubMed Central

    Heirali, Alya; McKeon, Suzanne; Purighalla, Swathi; Storey, Douglas G.; Rossi, Laura; Costilhes, Geoffrey; Drews, Steven J.; Rabin, Harvey R.; Surette, Michael G.; Parkins, Michael D.

    2016-01-01

    Introduction Cystic fibrosis (CF) airways are colonized by a polymicrobial community of organisms, termed the CF microbiota. We sought to define the microbial constituents of the home environment of individuals with CF and determine if it may serve as a latent reservoir for infection. Methods Six patients with newly identified CF pathogens were included. An investigator collected repeat sputum and multiple environmental samples from their homes. Bacteria were cultured under both aerobic and anaerobic conditions. Morphologically distinct colonies were selected, purified and identified to the genus and species level through 16S rRNA gene sequencing. When concordant organisms were identified in sputum and environment, pulsed-field gel electrophoresis (PFGE) was performed to determine relatedness. Culture-independent bacterial profiling of each sample was carried out by Illumina sequencing of the V3 region of the 16s RNA gene. Results New respiratory pathogens prompting investigation included: Mycobacterium abscessus(2), Stenotrophomonas maltophilia(3), Pseudomonas aeruginosa(3), Pseudomonas fluorescens(1), Nocardia spp.(1), and Achromobacter xylosoxidans(1). A median 25 organisms/patient were cultured from sputum. A median 125 organisms/home were cultured from environmental sites. Several organisms commonly found in the CF lung microbiome were identified within the home environments of these patients. Concordant species included members of the following genera: Brevibacterium(1), Microbacterium(1), Staphylococcus(3), Stenotrophomonas(2), Streptococcus(2), Sphingomonas(1), and Pseudomonas(4). PFGE confirmed related strains (one episode each of Sphinogomonas and P. aeruginosa) from the environment and airways were identified in two patients. Culture-independent assessment confirmed that many organisms were not identified using culture-dependent techniques. Conclusions Members of the CF microbiota can be found as constituents of the home environment in individuals with CF. While the majority of isolates from the home environment were not genetically related to those isolated from the lower airways of individuals with CF suggesting alternate sources of infection were more common, a few genetically related isolates were indeed identified. As such, the home environment may rarely serve as either the source of infection or a persistent reservoir for re-infection after clearance. PMID:26859493

  19. Acquisition and Evolution of Plant PathogenesisAssociated Gene Clusters and Candidate Determinants of Tissue-Specificity in Xanthomonas

    PubMed Central

    Van Sluys, Marie-Anne; White, Frank F.; Ryan, Robert P.; Dow, J. Maxwell; Rabinowicz, Pablo; Salzberg, Steven L.; Leach, Jan E.; Sonti, Ramesh; Brendel, Volker; Bogdanove, Adam J.

    2008-01-01

    Background Xanthomonas is a large genus of plant-associated and plant-pathogenic bacteria. Collectively, members cause diseases on over 392 plant species. Individually, they exhibit marked host- and tissue-specificity. The determinants of this specificity are unknown. Methodology/Principal Findings To assess potential contributions to host- and tissue-specificity, pathogenesis-associated gene clusters were compared across genomes of eight Xanthomonas strains representing vascular or non-vascular pathogens of rice, brassicas, pepper and tomato, and citrus. The gum cluster for extracellular polysaccharide is conserved except for gumN and sequences downstream. The xcs and xps clusters for type II secretion are conserved, except in the rice pathogens, in which xcs is missing. In the otherwise conserved hrp cluster, sequences flanking the core genes for type III secretion vary with respect to insertion sequence element and putative effector gene content. Variation at the rpf (regulation of pathogenicity factors) cluster is more pronounced, though genes with established functional relevance are conserved. A cluster for synthesis of lipopolysaccharide varies highly, suggesting multiple horizontal gene transfers and reassortments, but this variation does not correlate with host- or tissue-specificity. Phylogenetic trees based on amino acid alignments of gum, xps, xcs, hrp, and rpf cluster products generally reflect strain phylogeny. However, amino acid residues at four positions correlate with tissue specificity, revealing hpaA and xpsD as candidate determinants. Examination of genome sequences of xanthomonads Xylella fastidiosa and Stenotrophomonas maltophilia revealed that the hrp, gum, and xcs clusters are recent acquisitions in the Xanthomonas lineage. Conclusions/Significance Our results provide insight into the ancestral Xanthomonas genome and indicate that differentiation with respect to host- and tissue-specificity involved not major modifications or wholesale exchange of clusters, but subtle changes in a small number of genes or in non-coding sequences, and/or differences outside the clusters, potentially among regulatory targets or secretory substrates. PMID:19043590

  20. Microbiological investigation of Raphanus sativus L. grown hydroponically in nutrient solutions contaminated with spoilage and pathogenic bacteria.

    PubMed

    Settanni, Luca; Miceli, Alessandro; Francesca, Nicola; Cruciata, Margherita; Moschetti, Giancarlo

    2013-01-01

    The survival of eight undesired (spoilage/pathogenic) food related bacteria (Citrobacter freundii PSS60, Enterobacter spp. PSS11, Escherichia coli PSS2, Klebsiella oxytoca PSS82, Serratia grimesii PSS72, Pseudomonas putida PSS21, Stenotrophomonas maltophilia PSS52 and Listeria monocytogenes ATCC 19114(T)) was investigated in mineral nutrient solution (MNS) during the crop cycle of radishes (Raphanus sativus L.) cultivated in hydroponics in a greenhouse. MNSs were microbiologically analyzed weekly by plate count. The evolution of the pure cultures was also evaluated in sterile MNS in test tubes. The inoculated trials contained an initial total mesophilic count (TMC) ranging between 6.69 and 7.78Log CFU/mL, while non-sterile and sterile control trials showed levels of 4.39 and 0.97Log CFU/mL, respectively. In general, all inoculated trials showed similar levels of TMC in MNS during the experimentation, even though the levels of the inoculated bacteria decreased. The presence of the inoculums was ascertained by randomly amplified polymorphic DNA (RAPD) analysis applied on the isolates collected at 7-day intervals. At harvest, MNSs were also analyzed by denaturing gradient gel electrophoresis (DGGE). The last analysis, except P. putida PSS21 in the corresponding trial, did not detect the other bacteria, but confirmed that pseudomonads were present in un-inoculated MNSs. Despite the high counts detected (6.44 and 7.24CFU/g), only C. freundii PSS60, Enterobacter spp. PSS11 and K. oxytoca PSS82 were detected in radishes in a living form, suggesting their internalization. PMID:23290244

  1. In vitro volatile organic compound profiling using GC×GC-TOFMS to differentiate bacteria associated with lung infections: a proof-of-concept study.

    PubMed

    Nizio, K D; Perrault, K A; Troobnikoff, A N; Ueland, M; Shoma, S; Iredell, J R; Middleton, P G; Forbes, S L

    2016-01-01

    Chronic pulmonary infections are the principal cause of morbidity and mortality in individuals with cystic fibrosis (CF). Due to the polymicrobial nature of these infections, the identification of the particular bacterial species responsible is an essential step in diagnosis and treatment. Current diagnostic procedures are time-consuming, and can also be expensive, invasive and unpleasant in the absence of spontaneously expectorated sputum. The development of a rapid, non-invasive methodology capable of diagnosing and monitoring early bacterial infection is desired. Future visions of real-time, in situ diagnosis via exhaled breath testing rely on the differentiation of bacteria based on their volatile metabolites. The objective of this proof-of-concept study was to investigate whether a range of CF-associated bacterial species (i.e. Pseudomonas aeruginosa, Burkholderia cenocepacia, Haemophilus influenzae, Stenotrophomonas maltophilia, Streptococcus pneumoniae and Streptococcus milleri) could be differentiated based on their in vitro volatile metabolomic profiles. Headspace samples were collected using solid phase microextraction (SPME), analyzed using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS) and evaluated using principal component analysis (PCA) in order to assess the multivariate structure of the data. Although it was not possible to effectively differentiate all six bacteria using this method, the results revealed that the presence of a particular pattern of VOCs (rather than a single VOC biomarker) is necessary for bacterial species identification. The particular pattern of VOCs was found to be dependent upon the bacterial growth phase (e.g. logarithmic versus stationary) and sample storage conditions (e.g. short-term versus long-term storage at  -18 °C). Future studies of CF-associated bacteria and exhaled breath condensate will benefit from the approaches presented in this study and further facilitate the production of diagnostic tools for the early detection of bacterial lung infections. PMID:27120170

  2. Bacterial resistance control on mineral surfaces of hydroxyapatite and human teeth via surface charge-driven antifouling coatings.

    PubMed

    Venault, Antoine; Yang, Hui-Shan; Chiang, Yen-Che; Lee, Bor-Shuinn; Ruaan, Ruoh-Chyu; Chang, Yung

    2014-03-12

    This works reports a set of new functionalized polyethyleneimine (PEI) polymers, including a neutral PEGylated polymer PEI-g-PEGMA, a negatively charged polymer PEI-g-SA, and a zwitterionic polymer PEI-g-SBMA, and their use as antibiofouling coating agent for human teeth protection. Polymers were synthesized by Michael addition, XPS analysis revealed that each polymer could be efficiently coated onto hydroxyapatite, ceramic material used as a model tooth. Polymers carrying a negative net charge were more efficiently adsorbed, because of the establishment of electrostatic interactions with calcium ions. Protein adsorption tests revealed that two factors were important in the reduction of protein adsorption. Both the surface charge and the surface ability to bind and entrap water molecules had to be considered. PEI-g-SBMA, which zeta potential in PBS solution was negative, was efficient to inhibit the adsorption of BSA, a negative protein. On the other hand, it also resisted the adsorption of lysozyme, a positive protein, because zwitterionic molecules can easily entrap water and provide a very hydrophilic environment. Streptococcus mutans attachment tests performed unveiled that all modified polymers were efficient to resist this type of bacteria responsible for dental carries. Best results were also obtained with PEI-g-SBMA coating. This polymer was also shown to efficiently resist the adsorption of positively charged bacteria (Stenotrophomonas maltophilia). Tests performed on real human tooth showed that PEI-g-SBMA could inhibit up to 70% of bacteria adhesion, which constitutes a major result considering that surface of teeth is very rough, therefore physically promoting the attachment of proteins and bacteria. PMID:24513459

  3. Interactions in biofilms between Listeria monocytogenes and resident microorganisms from food industry premises.

    PubMed

    Carpentier, Brigitte; Chassaing, Danielle

    2004-12-15

    Twenty nine bacterial strains were grown as binary culture biofilms with Listeria monocytogenes to assess their influence on the settlement of the latter on stainless steel coupons. Most of the strains had been isolated from food processing plants after cleaning and disinfection and were tentatively identified by the APILAB Plus 3.3.3 database (bioMerieux). Sixteen of them decreased L. monocytogenes biofilm colony forming units (CFU) counts. Three strains, Bacillus sp. CCL 9 an unidentified Gram-positive strain CCL 59 and Pseudomonas fluorescens E9. 1, led to a 3-log difference in CFU counts between the pure L. monocytogenes biofilms and the mixed biofilms. Eleven strains had no effect and only four, Kocuria varians CCL 73, Staphylococcus capitis CCL 54, Stenotrophomonas maltophilia CCL 47 and Comamonas testosteroni CCL 24, had a positive effect, with a 0.5- to 1.0-log increase in the L. monocytogenes biofilm CFU counts. On its own, L. monocytogenes settled as single cells, but in binary biofilms, different spatial arrangements were observed: (i) with K. varians CCL 73, K. varians CCL 56 and S. capitis CCL 54, L. monocytogenes cells gathered around the microcolonies of the partner strain; (ii) with the two Gram-negative strains, C. testosteroni CCL 24 and CCL 25, L. monocytogenes cells formed its own microcolonies. No link could be found between the exopolysaccharide production capacity of the bacterial strains in pure-culture biofilms and their effect on the L. monocytogenes population in mixed biofilms. With one strain, C. testosteroni CCL 24, adding filter-sterilized supernatant from a pure-culture biofilm to a pure culture of L. monocytogenes increased the number of L. monocytogenes cells adhering to the stainless steel coupons and forming microcolonies. This study suggests that the "house flora" can have a strong effect on the likelihood of finding L. monocytogenes on inert surfaces. PMID:15541798

  4. Pathogen distribution and drug resistance in a burn ward: a three-year retrospective analysis of a single center in China

    PubMed Central

    Cen, Hanghui; Wu, Zhenbo; Wang, Fan; Han, Chunmao

    2015-01-01

    To investigate the spread of multiple-resistant strain in a burn ward to inform clinical administration of antibiotic drugs, burn wound treatment and decision-making for infection control. A 3-year retrospective analysis was conducted. Specimens from wounds, blood, catheter, sputum, urine and stool collected from inpatients of the Second Affiliated Hospital of Zhejiang University of Medicine between January 1, 2011 and December 31, 2013 were cultured and strains were identified by automatic bacteria analysis. Sensitivity to 30 commonly used antibiotics was assessed by K-B disk diffusion. A total of 2212 strains of pathogenic bacteria or fungi were isolated (33.9% Gram-positive and 52.7% Gram-negative bacteria and 13.4% fungi), including 1466 from wound extracts, 128 from blood culture, 335 from urine culture, 5 from stool culture, 153 from sputum culture and 125 from catheters. The most frequently detected pathogens in wound secretions were Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii. The Gram-positive bacteria Staphylococcus epidermidis, Enterococcus faecalis and Enterococcus faecium, and the Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Stenotrophomonas maltophilia, Proteus mirabilis were also frequently detected. The most frequently detected strains of fungi were Candida albicans; tropicalis, glabrata and parapsilosis, and all were highly sensitive to itraconazole, fluconazole and voriconazole but resistant to ketoconazole. Attention should be paid to MRSA, multi-resistant A. baumanni, ESBL-producing enterobacteriaceae and Carbapenem-resistant P. aeruginosa. Understanding the distribution of bacterial infections in Chinese hospitals will be crucial to reduce hospital-acquired infection and drug resistance. PMID:26770555

  5. Bacterial reduction of selenium in coal mine tailings pond sediment

    SciTech Connect

    Siddique, T.; Arocena, J.M.; Thring, R.W.; Zhang, Y.Q.

    2007-05-15

    Sediment from a storage facility for coal tailings solids was assessed for its capacity to reduce selenium (Se) by native bacterial community. One Se{sup 6+}-reducing bacterium Enterobacter hormaechei (Tar11) and four Se{sup 4+}-reducing bacteria, Klebsiella pneumoniae (Tar1), Pseudomonasfluorescens (Tar3), Stenotrophomonas maltophilia (Tar6), and Enterobacter amnigenus (Tar8) were isolated from the sediment. Enterobacter horinaechei removed 96% of the added Se{sup 6+} (0.92 mg L{sup -1} from the effluents when Se6+ was determined after 5 d of incubation. Analysis of the red precipitates showed that Se{sup 6+} reduction resulted in the formation of spherical particles ({lt}1.0 {mu} m) of Se 0 as observed under scanning electron microscope (SEM) and confirmed by EDAX. Selenium speciation was performed to examine the fate of the added Se{sup 6+} in the sediment with or without addition of Enterobacter hormaechei cells. More than 99% of the added Se{sup 6+} (about 2.5 mg L{sup -1}) was transformed in the nonsterilized sediment (without Enterobacter hormaechei cells) as well as in the sterilized (heat-killed) sediment (with Enterobacter hormaechei cells). The results of this study suggest that the lagoon sediments at the mine site harbor Se{sup 6+}- and Se{sup 4+} -reducing bacteria and may be important sinks for soluble Se (Se{sup 6+} and Se{sup 4+}). Enterobacter hormaechei isolated from metal-contaminated sediment may have potential application in removing Se from industrial effluents.

  6. CQ-397 and CQ-414: antimicrobial activity and spectrum of two fluoroquinolone---cephalosporin, dual-action compounds with carboxamido bonds.

    PubMed

    Johnson, David M.; Jones, Ronald N.

    1997-06-01

    OBJECTIVE: To evaluate the potential spectrum of activity of two novel dual-action compounds with carboxamido bonds (CQ-397 and CQ-414; Laboratorios Aranda, San Rafael, Mexico) against human pathogens. METHODS: Approximately 800 Gram-positive and Gram-negative aerobic clinical bacteria were tested in vitro using the Mueller-Hinton broth microdilution method of the National Committee of Clinical Laboratory Standards. RESULTS: CQ-397 (cefamandole+enrofloxacin) and CQ-414 (cefamandole+norfloxacin) were equally potent against Enterobacteriaceae (MIC90 range, 0.06--0.5 microg/mL and 0.06--1 microg/mL, respectively). Citrobacter freundii (MIC90, 4 microg/mL) and Providencia spp. (MIC90, >32 microg/mL) exhibited elevated study drug MICs. Enterobacteriaceae resistant to fluoroquinolones generally remained resistant. CQ-397 and CQ-414 were active against Stenotrophomonas maltophilia (MIC90, 4 microg/mL) and oxacillin-susceptible staphylococci (MIC90, 0.25 microg/mL), but not oxacillin-resistant Staphylococcus aureus (MIC90, >32 microg/mL), Staphylococcus epidermidis (MIC90, 8 microg/mL), and enterococci (MIC90s, 8 to >32 microg/mL). There was no difference in the dual-action drug activity (MIC90, 2 microg/mL) between penicillin-susceptible and -resistant pneumococci. Haemophilus influenzae and Moraxella catarrhalis were very susceptible (MIC range, less-than-or-equal0.015--0.06 microg/mL) to both compounds. CONCLUSIONS: The activity of these novel dual-action compounds, formed from the bonding of older antimicrobials, warrants further investigation for potential human and/or animal health use, including toxicology and pharmacokinetics. PMID:11864130

  7. Rapid Automated Microscopy for Microbiological Surveillance of Ventilator-associated Pneumonia

    PubMed Central

    Price, Connie S.; Overdier, Katherine H.; Wolken, Robert F.; Metzger, Steven W.; Hance, Kenneth R.; Howson, David C.

    2015-01-01

    Rationale: Diagnosis of ventilator-associated pneumonia (VAP) is imprecise. Objectives: To (1) determine whether alternate-day surveillance mini–bronchoalveolar lavage (mini-BAL) in ventilated adults could reduce time to initiation of targeted treatment and (2) evaluate the potential for automated microscopy to reduce analysis time. Methods: Adult intensive care unit patients who were anticipated to require ventilation for at least a further 48 hours were included. Mini-BALs were processed for identification, quantitation, and antibiotic susceptibility, using (1) clinical culture (50 ± 7 h) and (2) automated microscopy (∼5 h plus offline analysis). Measurements and Main Results: Seventy-seven mini-BALs were performed in 33 patients. One patient (3%) was clinically diagnosed with VAP. Of 73 paired samples, culture identified 7 containing pneumonia panel bacteria (>104 colony-forming units/ml) from five patients (15%) (4 Staphylococcus aureus [3 methicillin-resistant S. aureus], 2 Stenotrophomonas maltophilia, 1 Klebsiella pneumoniae) and resulted in antimicrobial changes/additions to two of five (40%) of those patients. Microscopy identified 7 of 7 microbiologically positive organisms and 64 of 66 negative samples compared with culture. Antimicrobial responses were concordant in four of five comparisons. Antimicrobial changes/additions would have occurred in three of seven microscopy-positive patients (43%) had those results been clinically available in 5 hours, including one patient diagnosed later with VAP despite negative mini-BAL cultures. Conclusions: Microbiological surveillance detected infection in patients at risk for VAP independent of clinical signs, resulting in changes to antimicrobial therapy. Automated microscopy was 100% sensitive and 97% specific for high-risk pneumonia organisms compared with clinical culturing. Rapid microscopy-based surveillance may be informative for treatment and antimicrobial stewardship in patients at risk for VAP. PMID:25585163

  8. Species distribution and antimicrobial susceptibility of gram-negative aerobic bacteria in hospitalized cancer patients

    PubMed Central

    Ashour, Hossam M; El-Sharif, Amany

    2009-01-01

    Background Nosocomial infections pose significant threats to hospitalized patients, especially the immunocompromised ones, such as cancer patients. Methods This study examined the microbial spectrum of gram-negative bacteria in various infection sites in patients with leukemia and solid tumors. The antimicrobial resistance patterns of the isolated bacteria were studied. Results The most frequently isolated gram-negative bacteria were Klebsiella pneumonia (31.2%) followed by Escherichia coli (22.2%). We report the isolation and identification of a number of less-frequent gram negative bacteria (Chromobacterium violacum, Burkholderia cepacia, Kluyvera ascorbata, Stenotrophomonas maltophilia, Yersinia pseudotuberculosis, and Salmonella arizona). Most of the gram-negative isolates from Respiratory Tract Infections (RTI), Gastro-intestinal Tract Infections (GITI), Urinary Tract Infections (UTI), and Bloodstream Infections (BSI) were obtained from leukemic patients. All gram-negative isolates from Skin Infections (SI) were obtained from solid-tumor patients. In both leukemic and solid-tumor patients, gram-negative bacteria causing UTI were mainly Escherichia coli and Klebsiella pneumoniae, while gram-negative bacteria causing RTI were mainly Klebsiella pneumoniae. Escherichia coli was the main gram-negative pathogen causing BSI in solid-tumor patients and GITI in leukemic patients. Isolates of Escherichia coli, Klebsiella, Enterobacter, Pseudomonas, and Acinetobacter species were resistant to most antibiotics tested. There was significant imipenem -resistance in Acinetobacter (40.9%), Pseudomonas (40%), and Enterobacter (22.2%) species, and noticeable imipinem-resistance in Klebsiella (13.9%) and Escherichia coli (8%). Conclusion This is the first study to report the evolution of imipenem-resistant gram-negative strains in Egypt. Mortality rates were higher in cancer patients with nosocomial Pseudomonas infections than any other bacterial infections. Policies restricting antibiotic consumption should be implemented to avoid the evolution of newer generations of antibiotic resistant-pathogens. PMID:19228413

  9. Novel Cyclic di-GMP Effectors of the YajQ Protein Family Control Bacterial Virulence

    PubMed Central

    An, Shi-qi; Caly, Delphine L.; McCarthy, Yvonne; Murdoch, Sarah L.; Ward, Joseph; Febrer, Melanie; Dow, J. Maxwell; Ryan, Robert P.

    2014-01-01

    Bis-(3′,5′) cyclic di-guanylate (cyclic di-GMP) is a key bacterial second messenger that is implicated in the regulation of many critical processes that include motility, biofilm formation and virulence. Cyclic di-GMP influences diverse functions through interaction with a range of effectors. Our knowledge of these effectors and their different regulatory actions is far from complete, however. Here we have used an affinity pull-down assay using cyclic di-GMP-coupled magnetic beads to identify cyclic di-GMP binding proteins in the plant pathogen Xanthomonas campestris pv. campestris (Xcc). This analysis identified XC_3703, a protein of the YajQ family, as a potential cyclic di-GMP receptor. Isothermal titration calorimetry showed that the purified XC_3703 protein bound cyclic di-GMP with a high affinity (Kd∼2 µM). Mutation of XC_3703 led to reduced virulence of Xcc to plants and alteration in biofilm formation. Yeast two-hybrid and far-western analyses showed that XC_3703 was able to interact with XC_2801, a transcription factor of the LysR family. Mutation of XC_2801 and XC_3703 had partially overlapping effects on the transcriptome of Xcc, and both affected virulence. Electromobility shift assays showed that XC_3703 positively affected the binding of XC_2801 to the promoters of target virulence genes, an effect that was reversed by cyclic di-GMP. Genetic and functional analysis of YajQ family members from the human pathogens Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed that they also specifically bound cyclic di-GMP and contributed to virulence in model systems. The findings thus identify a new class of cyclic di-GMP effector that regulates bacterial virulence. PMID:25329577

  10. Fate of plasmid-bearing, luciferase marker gene tagged bacteria after feeding to the soil microarthropod Onychiurus fimatus (Collembola).

    PubMed

    Hoffmann; Thimm; Tebbe

    1999-10-01

    In order to study the potential impact of the soil microarthropod Onychiurus fimatus (Collembola) on the microbial community, we analysed the fate of luciferase marker gene tagged bacterial strains fed to young adult specimens in petri dish microcosm experiments. In faeces collected from O. fimatus, Escherichia coli S17-1/pRP4luc and Sinorhizobium meliloti L33 were only detectable for 2 days after feeding whereas strain HR2/pRP4luc, a close relative of Stenotrophomonas maltophilia, isolated from another collembolan species, could be detected for 16 days. The amount of shed cells of strain HR2 increased during the frequent releases of the cast-off skins (exuvia). In order to analyse whether gut associated bacteria could serve as recipients for mobile genetic elements, plasmid-bearing E. coli donor strains were incubated with faeces in filter mating-like experiments and, in other experiments, directly fed to O. fimatus specimens. Transconjugants were obtained with both the conjugative self-transferable broad host range plasmid pRP4luc and the mobilisable (Mob(+)) broad host range plasmid pSUP104luc, the latter, however, only with a mobilising donor strain. No transfer was detected with the narrow host range plasmids pSUP202luc (Mob(+)), pUC18luc (Mob(-)), or with the broad host range transposon delivery plasmid pUTluxCDABE (Mob(+)). Transconjugants of pRP4luc were detected within one day of the beginning of a feeding experiment and then throughout the incubation period of two weeks, with gaps of no detection after 5, 12 and 14 days, probably caused by moulting. The results of this study indicate that feeding activities of collembola can modify the structure of soil-inhabiting microbial communities and enhance the spread of plasmids from non-indigenous to indigenous soil bacteria. PMID:10508937

  11. Antibacterial activities of a fosfomycin/tobramycin combination: a novel inhaled antibiotic for bronchiectasis

    PubMed Central

    MacLeod, David L.; Barker, Lynn M.; Sutherland, Jennifer L.; Moss, Suzanne C.; Gurgel, Jesse L.; Kenney, Thomas F.; Burns, Jane L.; Baker, William R.

    2009-01-01

    Objectives To compare the in vitro and in vivo activities of a 4:1 (w/w) fosfomycin/tobramycin combination (FTI) with those of fosfomycin and tobramycin alone against cystic fibrosis (CF) and non-CF bronchiectasis pathogens. Methods Clinical isolates of CF Pseudomonas aeruginosa, Staphylococcus aureus, Haemophilus influenzae, Stenotrophomonas maltophilia, Burkholderia cepacia complex, Escherichia coli and Klebsiellia spp. were evaluated by MIC, MBC, post-antibiotic effect (PAE), synergy, time–kill, a rat pneumonia model and spontaneous mutation frequency (SMF). Results FTI showed high activity against E. coli, H. influenzae, S. aureus and Klebsiella spp. For the S. aureus strains, 75% of which were methicillin resistant (MRSA), FTI had a lower MIC90 than tobramycin. For P. aeruginosa, FTI had a lower MIC90 than fosfomycin, but tobramycin was more active than either. Synergy studies showed no antagonism between fosfomycin and tobramycin, and 93% of the isolates demonstrated no interaction. FTI was rapidly bactericidal and exhibited concentration-dependent killing in time–kill studies. In the rat pneumonia model, FTI and tobramycin demonstrated bactericidal killing of P. aeruginosa; both were more active than fosfomycin alone. The SMF for S. aureus resistance to FTI was 2–4 log10 lower than that for tobramycin and 2–7 log10 lower than that for fosfomycin. For P. aeruginosa, the FTI SMF was 2–3 log10 lower than that for fosfomycin and 1–2 log10 lower than that for tobramycin. Conclusions FTI is a broad-spectrum antibiotic combination with high activity in vitro and in vivo. These data suggest FTI could be a potential treatment for respiratory infections caused by Gram-positive and Gram-negative aerobic bacteria. PMID:19679597

  12. Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry: rapid identification of bacteria isolated from patients with cystic fibrosis.

    PubMed

    Baillie, S; Ireland, K; Warwick, S; Wareham, D; Wilks, M

    2013-01-01

    Despite extensive research into the diagnosis and management of cystic fibrosis (CF) over the past decades, sufferers still have a median life expectancy of less than 37 years. Respiratory tract infections have a significant role in increasing the morbidity and mortality of patients with CF via a progressive decline in lung function. Rapid identification of organisms recovered from CF sputum is necessary for effective management of respiratory tract infections; however, standard techniques of identification are slow, technically demanding and expensive. The aim of this study is to asses the suitability of matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS) in identifying bacteria isolated from the respiratory tract of patients with CF, and is assessed by testing the accuracy of MALDI-TOF MS in identifying samples from a reference collection of rare CF strains in conjunction with comparing MALDI-TOF MS and standard techniques in identifying clinical isolates from sputum samples of CF patients. MALDI-TOF MS accurately identified 100% of isolates from the reference collection of rare CF pathogens (EuroCare CF collection). The isolate identification given by MALDI-TOF MS agreed with that given by standard techniques for 479/481 (99.6%) clinical isolates obtained from respiratory samples provided by patients with CE In two (0.4%) of 481 samples there was a discrepancy in identification between MALDI-TOF MS and standard techniques. One organism was identified as Pseudomonas aeruginosa by MALDI-TOF but could only be identified by the laboratory's standard methods as of the Pseudomonas genus. The second organism was identified as P. beteli by MALDI-TOF MS and Stenotrophomonas maltophilia by standard methods. This study shows that MALDI-TOF MS is superior to standard techniques in providing cheap, rapid and accurate identification of CF sputum isolates. PMID:24400425

  13. [Isolation and characterization of two bacteria with heavy metal resistance and phosphate solubilizing capability].

    PubMed

    Tian, Jiang; Peng, Xia-Wei; Li, Xia; Sun, Ya-Jun; Feng, Hong-Mei; Jiang, Ze-Ping

    2014-06-01

    Two phosphate solubilizing bacteria (T PSB1 and T PSB 2) with high heavy metal resistance were isolated from soil of a lead-zinc mine in Huayuan of Hunan Province, China. These two bacteria were identified as Stenotrophomonas maltophilia and Burkholderia gladioli by 16S rRNA sequencing analysis, respectively. In the media containing insoluble inorganic calcium phosphate, the soluble phosphate amounts reached respectively 402.9 mg x L(-1) and 589.9 mg x L(-1) with the bacteria T PSB1 and T PSB2 after two weeks' growth. Moreover, the two bacteria developed solubilizing halos on the plates supplemented with the organic phosphate compounds, and the resulting soluble phosphate amounts in the broth media were respectively 2.97 mg x L(-1) and 4.69 mg x L(-1). In addition, these two bacteria showed the resistance to up to 2000 mg x L(-1) Zn2+, and their phosphate solubilizing amounts reached respectively 114.8 mg x L(-1) and 125.1 mg x L(-1). Similarly, their heavy metal resistance and phosphate solubilizing ability were also found in the Cr and Pb broth media with the concentration of 1000 mg x L(-1). In the Pb media, the soluble phosphate amounts reached respectively 57.9 mg x L(-1) and 71.7 mg x L(-1), and the soluble P amounts in the Cr media were 60.1 mg x L(-1) and 98.4 mg x L(-1) at the concentration of 1000 mg x L(-1). PMID:25158515

  14. Chlor-alkali plant contamination of Aussa River sediments induced a large Hg-resistant bacterial community

    NASA Astrophysics Data System (ADS)

    Baldi, Franco; Marchetto, Davide; Gallo, Michele; Fani, Renato; Maida, Isabel; Covelli, Stefano; Fajon, Vesna; Zizek, Suzana; Hines, Mark; Horvat, Milena

    2012-11-01

    A closed chlor-alkali plant (CAP) discharged Hg for decades into the Aussa River, which flows into Marano Lagoon, resulting in the large-scale pollution of the lagoon. In order to get information on the role of bacteria as mercury detoxifying agents, analyses of anions in the superficial part (0-1 cm) of sediments were conducted at four stations in the Aussa River. In addition, measurements of biopolymeric carbon (BPC) as a sum of the carbon equivalent of proteins (PRT), lipids (LIP), and carbohydrates (CHO) were performed to correlate with bacterial biomass such as the number of aerobic heterotrophic cultivable bacteria and their percentage of Hg-resistant bacteria. All these parameters were used to assess the bioavailable Hg fraction in sediments and the potential detoxification activity of bacteria. In addition, fifteen isolates were characterized by a combination of molecular techniques, which permitted their assignment into six different genera. Four out of fifteen were Gram negative with two strains of Stenotrophomonas maltophilia, one Enterobacter sp., and one strain of Brevibacterium frigoritolerans. The remaining strains (11) were Gram positive belonging to the genera Bacillus and Staphylococcus. We found merA genes in only a few isolates. Mercury volatilization from added HgCl2 and the presence of plasmids with the merA gene were also used to confirm Hg reductase activity. We found the highest number of aerobic heterotrophic Hg-resistant bacteria (one order magnitude higher) and the highest number of Hg-resistant species (11 species out of 15) at the confluence of the River Aussa and Banduzzi's channel, which transport Hg from the CAP, suggesting that Hg is strongly detoxified [reduced to Hg(0)] at this location.

  15. A Pilot Study of Quantitative Loop-mediated Isothermal Amplification-guided Target Therapies for Hospital-acquired Pneumonia

    PubMed Central

    Wang, Fang; Li, Ran; Shang, Ying; Wang, Can; Wang, Guo-Qing; Zhou, De-Xun; Yang, Dong-Hong; Xi, Wen; Wang, Ke-Qiang; Bao, Jing; Kang, Yu; Gao, Zhan-Cheng

    2016-01-01

    Background: It is important to achieve the definitive pathogen identification in hospital-acquired pneumonia (HAP), but the traditional culture results always delay the target antibiotic therapy. We assessed the method called quantitative loop-mediated isothermal amplification (qLAMP) as a new implement for steering of the antibiotic decision-making in HAP. Methods: Totally, 76 respiratory tract aspiration samples were prospectively collected from 60 HAP patients. DNA was isolated from these samples. Specific DNA fragments for identifying 11 pneumonia-related bacteria were amplified by qLAMP assay. Culture results of these patients were compared with the qLAMP results. Clinical data and treatment strategies were analyzed to evaluate the effects of qLAMP results on clinical data. McNemar test and Fisher's exact test were used for statistical analysis. Results: The detection of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Stenotrophomonas maltophilia, Streptococcus pneumonia, and Acinetobacter baumannii by qLAMP was consistent with sputum culture (P > 0.05). The qLAMP results of 4 samples for Haemophilus influenzae, Legionella pneumophila, or Mycoplasma pneumonia (MP) were inconsistent with culture results; however, clinical data revealed that the qLAMP results were all reliable except 1 MP positive sample due to the lack of specific species identified in the final diagnosis. The improvement of clinical condition was more significant (P < 0.001) in patients with pathogen target-driven therapy based on qLAMP results than those with empirical therapy. Conclusion: qLAMP is a more promising method for detection of pathogens in an early, rapid, sensitive, and specific manner than culture. PMID:26830989

  16. Antibacterial Activity of Salvadora persica L. (Miswak) Extracts against Multidrug Resistant Bacterial Clinical Isolates

    PubMed Central

    Al-Ayed, Mohamed Saeed Zayed; Asaad, Ahmed Morad; Qureshi, Mohamed Ansar; Attia, Hany Goda; AlMarrani, Abduljabbar Hadi

    2016-01-01

    Much effort has focused on examining the inhibitory effect of Salvadora persica (miswak) on oral microorganisms, but information concerning its antibacterial activity against other human pathogens, particularly multidrug resistant (MDR) isolates, is scarce. Therefore, this study aimed to assess the in vitro antibacterial activities of Salvadora persica L. extracts against 10 MDR bacterial clinical isolates other than oral pathogens. The antibacterial activity of aqueous and methanol miswak extracts was assessed using the agar dilution and minimum inhibitory concentration (MIC) methods. Overall, the 400 mg/mL of miswak extract was the most effective on all strains. The methanol extract exhibited a stronger antibacterial activity against Gram-negative (3.3–13.6 mm) than Gram-positive (1.8–8.3 mm) bacteria. The lowest MIC value was seen for E. coli (0.39, 1.56 µg/mL), followed by Streptococcus pyogenes (1.56 µg/mL). The highest MIC value (6.25, 12.5 µg/mL) was recorded for methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumannii, and Stenotrophomonas maltophilia. This study demonstrates, for the first time, the moderate to strong antibacterial activity of miswak extracts against all tested MDR-pathogens. Methanol extract appears to be a potent antimicrobial agent that could be considered as complementary and alternative medicine against resistant pathogens. Further studies on a large number of MDR organisms are necessary to investigate and standardize the inhibitory effect of miswak extracts against these emerging pathogens. PMID:26904146

  17. Blood infections in patients treated at transplantation wards of a clinical hospital in Warsaw.

    PubMed

    Kierzkowska, M; Majewska, A; Dobrzaniecka, K; Sawicka-Grzelak, A; Mlynarczyk, A; Chmura, A; Durlik, M; Deborska-Materkowska, D; Paczek, L; Mlynarczyk, G

    2014-10-01

    Establishment of the etiology in blood infection is always advisable. The purpose of this study was to evaluate the proportion of different bacterial species, including aerobic and anaerobic bacteria in blood cultures of patients hospitalized in transplantation wards of a large clinical hospital between 2010 and 2012. A total of 1994 blood samples from patients who were treated at one of two transplantation wards of a large hospital in Warsaw were analyzed using an automated blood culture system, BacT/ALERT (bioMerieux, France). The 306 bacterial strains were obtained from the examined samples. The highest proportion were bacteria from the family Enterobacteriaceae (112 strains; 36.6%) with Escherichia coli (61 strains), Klebsiella pneumoniae (30 strains), and Enterobacter cloacae (10 strains) most commonly isolated. The non-fermenting bacilli constituted 21.6% (66 strains), with most common Stenotrophomonas maltophilia (31 strains), Pseudomonas aeruginosa (14 strains), Achromobacter spp. (12 strains), and Acinetobacter baumannii (3 strains). Most frequent Gram-positive bacteria were staphylococci (25.2%). Of 77 staphylococcal strains, 56 were coagulase-negative staphylococci and 21 Staphylococcus aureus. Other Gram-positive bacteria included enterococci (14 strains) and Streptococcus pneumoniae (1 strain). Obligatory anaerobic bacteria were represented by 19 strains (6.2% of total isolates). Among all Enterobacteriaceae, 49 isolates (43.7%) produced extended-spectrum ß-lactamases (ESBLs). Resistance to methicillin was detected in 62% of S aureus isolates and in 46% of coagulase-negative staphylococci. Of 14 enterococci cultured from blood samples, 2 strains (14.3%) were resistant to vancomycin. Both were Enterococcus faecium. Resistant strains of Gram-negative and Gram-positive bacteria are significant problems for patients in the transplantation ward. PMID:25380873

  18. Pathogen distribution and drug resistance in a burn ward: a three-year retrospective analysis of a single center in China.

    PubMed

    Cen, Hanghui; Wu, Zhenbo; Wang, Fan; Han, Chunmao

    2015-01-01

    To investigate the spread of multiple-resistant strain in a burn ward to inform clinical administration of antibiotic drugs, burn wound treatment and decision-making for infection control. A 3-year retrospective analysis was conducted. Specimens from wounds, blood, catheter, sputum, urine and stool collected from inpatients of the Second Affiliated Hospital of Zhejiang University of Medicine between January 1, 2011 and December 31, 2013 were cultured and strains were identified by automatic bacteria analysis. Sensitivity to 30 commonly used antibiotics was assessed by K-B disk diffusion. A total of 2212 strains of pathogenic bacteria or fungi were isolated (33.9% Gram-positive and 52.7% Gram-negative bacteria and 13.4% fungi), including 1466 from wound extracts, 128 from blood culture, 335 from urine culture, 5 from stool culture, 153 from sputum culture and 125 from catheters. The most frequently detected pathogens in wound secretions were Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii. The Gram-positive bacteria Staphylococcus epidermidis, Enterococcus faecalis and Enterococcus faecium, and the Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Stenotrophomonas maltophilia, Proteus mirabilis were also frequently detected. The most frequently detected strains of fungi were Candida albicans; tropicalis, glabrata and parapsilosis, and all were highly sensitive to itraconazole, fluconazole and voriconazole but resistant to ketoconazole. Attention should be paid to MRSA, multi-resistant A. baumanni, ESBL-producing enterobacteriaceae and Carbapenem-resistant P. aeruginosa. Understanding the distribution of bacterial infections in Chinese hospitals will be crucial to reduce hospital-acquired infection and drug resistance. PMID:26770555

  19. Antimicrobial susceptibility of Gram-negative organisms isolated from patients hospitalised with pneumonia in US and European hospitals: results from the SENTRY Antimicrobial Surveillance Program, 2009-2012.

    PubMed

    Sader, Helio S; Farrell, David J; Flamm, Robert K; Jones, Ronald N

    2014-04-01

    Here we evaluated the frequency of occurrence and antimicrobial susceptibility patterns of Gram-negative bacteria isolated from patients hospitalised with pneumonia in medical centres in the USA (n=28) and Europe and the Mediterranean region (EMR) (n=25) in 2009-2012. Susceptibility testing was performed by reference broth microdilution methods. Overall, 12851 isolates were collected (6873/5978 in USA/EMR). The same top 11 organisms were observed in both geographic regions, but in different rank orders, and Gram-negative organisms represented 61.5/76.1% of strains in USA/EMR. Pseudomonas aeruginosa was the most frequently isolated Gram-negative organism in both regions (20.9/20.9% of cases in USA/EMR) and showed reduced susceptibility to most antimicrobials tested, including ceftazidime (79.6/68.7% susceptibility in USA/EMR), meropenem (76.3/65.8%) and piperacillin/tazobactam (72.9/63.9%). Klebsiella spp. was isolated from 9.7/11.6% of cases and showed extended-spectrum β-lactamase (ESBL) phenotype rates of 19.5/35.1% in USA/EMR. Meropenem and amikacin were active against 62.3/78.7% and 60.8/85.2% of ESBL phenotype Klebsiella spp. from USA/EMR, respectively. Enterobacter spp. ranked fourth in the USA (5.9%) and sixth in EMR (5.5%), whereas Escherichia coli ranked fifth in the USA (5.5%) and third in EMR (11.8%). Acinetobacter spp. and Stenotrophomonas maltophilia combined were isolated from 8.0/10.7% of cases in USA/EMR. A significant increase in P. aeruginosa susceptibility to meropenem and a significant decrease in gentamicin susceptibility among Klebsiella spp. were noted in EMR. These results confirm that very few agents remain broadly active against the most frequently isolated Gram-negative organisms from patients with pneumonia in US and EMR medical centres. PMID:24630306

  20. Mechanisms of antimicrobial resistance in Gram-negative bacilli.

    PubMed

    Ruppé, Étienne; Woerther, Paul-Louis; Barbier, François

    2015-12-01

    The burden of multidrug resistance in Gram-negative bacilli (GNB) now represents a daily issue for the management of antimicrobial therapy in intensive care unit (ICU) patients. In Enterobacteriaceae, the dramatic increase in the rates of resistance to third-generation cephalosporins mainly results from the spread of plasmid-borne extended-spectrum beta-lactamase (ESBL), especially those belonging to the CTX-M family. The efficacy of beta-lactam/beta-lactamase inhibitor associations for severe infections due to ESBL-producing Enterobacteriaceae has not been adequately evaluated in critically ill patients, and carbapenems still stands as the first-line choice in this situation. However, carbapenemase-producing strains have emerged worldwide over the past decade. VIM- and NDM-type metallo-beta-lactamases, OXA-48 and KPC appear as the most successful enzymes and may threaten the efficacy of carbapenems in the near future. ESBL- and carbapenemase-encoding plasmids frequently bear resistance determinants for other antimicrobial classes, including aminoglycosides (aminoglycoside-modifying enzymes or 16S rRNA methylases) and fluoroquinolones (Qnr, AAC(6')-Ib-cr or efflux pumps), a key feature that fosters the spread of multidrug resistance in Enterobacteriaceae. In non-fermenting GNB such as Pseudomonas aeruginosa, Acinetobacter baumannii and Stenotrophomonas maltophilia, multidrug resistance may emerge following the sole occurrence of sequential chromosomal mutations, which may lead to the overproduction of intrinsic beta-lactamases, hyper-expression of efflux pumps, target modifications and permeability alterations. P. aeruginosa and A. baumannii also have the ability to acquire mobile genetic elements encoding resistance determinants, including carbapenemases. Available options for the treatment of ICU-acquired infections due to carbapenem-resistant GNB are currently scarce, and recent reports emphasizing the spread of colistin resistance in environments with high volume of polymyxins use elicit major concern. PMID:26261001

  1. Effects of Agaricus lilaceps fairy rings on soil aggregation and microbial community structure in relation to growth stimulation of western wheatgrass (Pascopyrum smithii) in Eastern Montana rangeland.

    PubMed

    Caesar-Tonthat, The Can; Espeland, Erin; Caesar, Anthony J; Sainju, Upendra M; Lartey, Robert T; Gaskin, John F

    2013-07-01

    Stimulation of plant productivity caused by Agaricus fairy rings has been reported, but little is known about the effects of these fungi on soil aggregation and the microbial community structure, particularly the communities that can bind soil particles. We studied three concentric zones of Agaricus lilaceps fairy rings in Eastern Montana that stimulate western wheatgrass (Pascopyrum smithii): outside the ring (OUT), inside the ring (IN), and stimulated zone adjacent to the fungal fruiting bodies (SZ) to determine (1) soil aggregate proportion and stability, (2) the microbial community composition and the N-acetyl-β-D-glucosaminidase activity associated with bulk soil at 0-15 cm depth, (3) the predominant culturable bacterial communities that can bind to soil adhering to wheatgrass roots, and (4) the stimulation of wheatgrass production. In bulk soil, macroaggregates (4.75-2.00 and 2.00-0.25 mm) and aggregate stability increased in SZ compared to IN and OUT. The high ratio of fungal to bacteria (fatty acid methyl ester) and N-acetyl-β-D-glucosaminidase activity in SZ compared to IN and OUT suggest high fungal biomass. A soil sedimentation assay performed on the predominant isolates from root-adhering soil indicated more soil-binding bacteria in SZ than IN and OUT; Pseudomonas fluorescens and Stenotrophomonas maltophilia isolates predominated in SZ, whereas Bacillus spp. isolates predominated in IN and OUT. This study suggests that growth stimulation of wheatgrass in A. lilaceps fairy rings may be attributed to the activity of the fungus by enhancing soil aggregation of bulk soil at 0-15 cm depth and influencing the amount and functionality of specific predominant microbial communities in the wheatgrass root-adhering soil. PMID:23455430

  2. Antimicrobial activity of novel nanostructured Cu-SiO2 coatings prepared by chemical vapour deposition against hospital related pathogens.

    PubMed

    Varghese, Sajnu; Elfakhri, Souad O; Sheel, David W; Sheel, Paul; Bolton, Frederick J Eric; Foster, Howard A

    2013-01-01

    There is increasing recognition that the healthcare environment acts as an important reservoir for transmission of healthcare acquired infections (HCAI). One method of reducing environmental contamination would be use of antimicrobial materials. The antimicrobial activity of thin silica-copper films prepared by chemical vapour deposition was evaluated against standard strains of bacteria used for disinfectant testing and bacteria of current interest in HCAI. The structure of the coatings was determined using Scanning Electron Microscopy and their hardness and adhesion to the substrate determined. Antimicrobial activity was tested using a method based on BS ISO 22196:2007. The coatings had a pale green-brown colour and had a similar hardness to steel. SEM showed nano-structured aggregates of Cu within a silica matrix. A log10 reduction in viability of >5 could be obtained within 4 h for the disinfectant test strains and within 6 h for producing Acinetobacter baumannii, Klebsiella pneumoniae and Stenotrophomonas maltophilia. Activity against the other hospital isolates was slower but still gave log10 reduction factors of >5 for extended spectrum β-lactamase producing Escherichia coli and >3 for vancomycin resistant Enterococcus faecium, methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa within 24 h. The results demonstrate the importance of testing antimicrobial materials destined for healthcare use against isolates of current interest in hospitals as well as standard test strains. The coatings used here can also be applied to substrates such as metals and ceramics and have potential applications where reduction of microbial environmental contamination is desirable. PMID:24007899

  3. Isolation and Identification of Plant Growth Promoting Rhizobacteria from Cucumber Rhizosphere and Their Effect on Plant Growth Promotion and Disease Suppression

    PubMed Central

    Islam, Shaikhul; Akanda, Abdul M.; Prova, Ananya; Islam, Md. T.; Hossain, Md. M.

    2016-01-01

    Plant growth promoting rhizobacteria (PGPR) are the rhizosphere bacteria that may be utilized to augment plant growth and suppress plant diseases. The objectives of this study were to identify and characterize PGPR indigenous to cucumber rhizosphere in Bangladesh, and to evaluate their ability to suppress Phytophthora crown rot in cucumber. A total of 66 isolates were isolated, out of which 10 (PPB1, PPB2, PPB3, PPB4, PPB5, PPB8, PPB9, PPB10, PPB11, and PPB12) were selected based on their in vitro plant growth promoting attributes and antagonism of phytopathogens. Phylogenetic analysis of 16S rRNA sequences identified these isolates as new strains of Pseudomonas stutzeri, Bacillus subtilis, Stenotrophomonas maltophilia, and Bacillus amyloliquefaciens. The selected isolates produced high levels (26.78–51.28 μg mL-1) of indole-3-acetic acid, while significant acetylene reduction activities (1.79–4.9 μmole C2H4 mg-1 protein h-1) were observed in eight isolates. Cucumber plants grown from seeds that were treated with these PGPR strains displayed significantly higher levels of germination, seedling vigour, growth, and N content in root and shoot tissue compared to non-treated control plants. All selected isolates were able to successfully colonize the cucumber roots. Moreover, treating cucumber seeds with these isolates significantly suppressed Phytophthora crown rot caused by Phytophthora capsici, and characteristic morphological alterations in P. capsici hyphae that grew toward PGPR colonies were observed. Since these PGPR inoculants exhibited multiple traits beneficial to the host plants, they may be applied in the development of new, safe, and effective seed treatments as an alternative to chemical fungicides. PMID:26869996

  4. MALDI-TOF: a useful tool for laboratory identification of uncommon glucose non-fermenting Gram-negative bacteria associated with cystic fibrosis.

    PubMed

    Homem de Mello de Souza, Helena Aguilar Peres; Dalla-Costa, Libera Maria; Vicenzi, Fernando José; Camargo de Souza, Dilair; Riedi, Carlos Antônio; Filho, Nelson Augusto Rosario; Pilonetto, Marcelo

    2014-09-01

    The predisposition of patients with cystic fibrosis (CF) for recurrent pulmonary infections can result in poor prognosis of the disease. Although the clinical significance in CF of micro-organisms, such as Staphylococcus aureus, Haemophilus influenzae and Pseudomonas aeruginosa, is well established, the implication of uncommon glucose non-fermenting Gram-negative bacilli (UGNF-GNB) in respiratory samples from CF patients is still unclear. Because of limitations of traditional methods used in most clinical laboratories, the accurate identification of these microbes is a challenge. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) is an alternative tool for efficient identification of bacteria. This was a retrospective study to evaluate different identification methods in a collection of UGNF-GNB isolated from children with CF during a period of three years. The performance of MALDI-TOF was compared to that of 16S rDNA gene sequencing and to a conventional and automated phenotypic identification. The discriminatory power of MALDI-TOF (75.0 % agreement) was superior to automated techniques (67.1 % agreement) and to conventional phenotypical identification (50.0 % agreement). MALDI-TOF also demonstrated high accuracy in identifying Stenotrophomonas maltophilia, Achromobacter xylosoxidans and Chryseobacterium indologenes, but had limited utility in identifying Pandoraea spp. and some species of Acinetobacter and Chryseobacterium (other than C. indologenes). Although MALDI-TOF identified only 75 % of the isolates in comparison with 16S rDNA gene sequencing, the prompt identification and high discriminatory power exhibited by MALDI-TOF make it a useful tool for the characterization of micro-organisms that are difficult to identify using routine methods. PMID:24980571

  5. Faropenem: review of a new oral penem.

    PubMed

    Schurek, Kristen N; Wiebe, Ryan; Karlowsky, James A; Rubinstein, Ethan; Hoban, Daryl J; Zhanel, George G

    2007-04-01

    Faropenem medoxomil is a new orally administered penem antibiotic. Its chiral tetrahydrofuran substituent at position C2 is responsible for its improved chemical stability and reduced CNS effects, compared with imipenem. Faropenem demonstrates broad-spectrum in vitro antimicrobial activity against many Gram-positive and -negative aerobes and anaerobes, and is resistant to hydrolysis by nearly all beta-lactamases, including extended-spectrum beta-lactamases and AmpC beta-lactamases. However, faropenem is not active against methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, Pseudomonas aeruginosa or Stenotrophomonas maltophilia. Prospective, multicenter, randomized, double-blind, comparative (not vs placebo) clinical trials of acute bacterial sinusitis (ABS), acute exacerbations of chronic bronchitis (AECB), community-acquired pneumonia (CAP) and uncomplicated skin and skin structure infections (uSSSIs) have demonstrated that faropenem medoxomil has equivalent efficacy and safety compared with cefuroxime, clarithromycin, azithromycin, amoxicillin, cefpodoxime and amoxicillin-clavulanate. The evidence supports faropenem medoxomil as a promising new oral beta-lactam with proven efficacy and safety for the treatment of a variety of community-acquired infections. However, the US FDA recently rejected faropenem for all four indications stating that the clinical trials in ABS and AECB should have been performed versus a placebo. In the CAP studies, the FDA stated that they could not be certain of the validity of the study population actually having the disease and for uSSSI, the FDA stated that only a single trial was not adequate evidence of efficacy for this indication. PMID:17402834

  6. Evaluation of Microorganisms Cultured from Injured and Repressed Tissue Regeneration Sites in Endangered Giant Aquatic Ozark Hellbender Salamanders

    PubMed Central

    Nickerson, Cheryl A.; Ott, C. Mark; Castro, Sarah L.; Garcia, Veronica M.; Molina, Thomas C.; Briggler, Jeffrey T.; Pitt, Amber L.; Tavano, Joseph J.; Byram, J. Kelly; Barrila, Jennifer; Nickerson, Max A.

    2011-01-01

    Investigation into the causes underlying the rapid, global amphibian decline provides critical insight into the effects of changing ecosystems. Hypothesized and confirmed links between amphibian declines, disease, and environmental changes are increasingly represented in published literature. However, there are few long-term amphibian studies that include data on population size, abnormality/injury rates, disease, and habitat variables to adequately assess changes through time. We cultured and identified microorganisms isolated from abnormal/injured and repressed tissue regeneration sites of the endangered Ozark Hellbender, Cryptobranchus alleganiensis bishopi, to discover potential causative agents responsible for their significant decline in health and population. This organism and our study site were chosen because the population and habitat of C. a. bishopi have been intensively studied from 1969–2009, and the abnormality/injury rate and apparent lack of regeneration were established. Although many bacterial and fungal isolates recovered were common environmental organisms, several opportunistic pathogens were identified in association with only the injured tissues of C.a. bishopi. Bacterial isolates included Aeromonas hydrophila, a known amphibian pathogen, Granulicetella adiacens, Gordonai terrae, Stenotrophomonas maltophilia, Aerococcus viridans, Streptococcus pneumoniae and a variety of Pseudomonads, including Pseudomonas aeruginosa, P. stutzeri, and P. alcaligenes. Fungal isolates included species in the genera Penicillium, Acremonium, Cladosporium, Curvularia, Fusarium, Streptomycetes, and the Class Hyphomycetes. Many of the opportunistic pathogens identified are known to form biofilms. Lack of isolation of the same organism from all wounds suggests that the etiological agent responsible for the damage to C. a. bishopi may not be a single organism. To our knowledge, this is the first study to profile the external microbial consortia cultured from a Cryptobranchid salamander. The incidence of abnormalities/injury and retarded regeneration in C. a. bishopi may have many contributing factors including disease and habitat degradation. Results from this study may provide insight into other amphibian population declines. PMID:22205979

  7. Carbapenem Derivatives as Potential Inhibitors of Various β-Lactamases, Including Class B Metallo-β-Lactamases

    PubMed Central

    Nagano, Rie; Adachi, Yuka; Imamura, Hideaki; Yamada, Koji; Hashizume, Terutaka; Morishima, Hajime

    1999-01-01

    A variety of 1β-methylcarbapenem derivatives were screened to identify inhibitors of IMP-1 metallo-β-lactamase, a class B β-lactamase, in an automated microassay system using nitrocefin as a substrate. The structure–inhibitory-activity relationship study revealed that three types of 1β-methylcarbapenems having benzothienylthio, dithiocarbamate, or pyrrolidinylthio moieties at the C-2 position showed good inhibitory activity. Among the compounds screened, J-110,441, having a benzothienylthio moiety at the C-2 position of 1β-methylcarbapenem, was the most potent inhibitor of class B metallo-β-lactamases with Ki values of 0.0037, 0.23, 1.00, and 0.83 μM for IMP-1 encoded by the blaIMP gene, CcrA from Bacteroides fragilis, L1 from Stenotrophomonas maltophilia, and type II from Bacillus cereus, respectively. In a further characterization study, J-110,441 also showed inhibitory activity against TEM-type class A serine β-lactamase and chromosomal class C serine β-lactamase from Enterobacter cloacae with Ki values of 2.54 and 0.037 μM, respectively. Combining imipenem or ceftazidime with J-110,441 had a synergistic effect on the antimicrobial activity against β-lactamase-producing bacteria. Against the isolates of IMP-1-producing Serratia marcescens, the MICs of imipenem decreased to levels ranging from 1/64 to 1/4 in the presence of one-fourth of the MIC of J-110,441. Against E. cloacae producing high levels of class C β-lactamase, the MIC of ceftazidime decreased from 64 to 4 μg/ml in the presence of 4 μg of J-110,441 per ml. This is the first report to describe a new class of inhibitor of class B and class C β-lactamases including transferable IMP-1 metallo-β-lactamases. PMID:10508031

  8. Composting and vermicomposting experiences in the treatment and bioconversion of asphaltens from the Prestige oil spill.

    PubMed

    Martín-Gil, Jesús; Navas-Gracia, Luís Manuel; Gómez-Sobrino, Ernesto; Correa-Guimaraes, Adriana; Hernández-Navarro, Salvador; Sánchez-Báscones, Mercedes; del Carmen Ramos-Sánchez, María

    2008-04-01

    This work illustrates the effectiveness of composting and vermicomposting in degrading fuel-in-water emulsions from oil spills (chapapote), and the isolation of potentially useful microorganisms for its biodegradation. Firstly, an alternative to the biodegradation of asphaltens from the Prestige oil spill (still present in some chapapote rafts in the Cantabrian coast) by means of the application of composting techniques to a microbial partnership acclimated to fuel-oil is offered. Our aim is that, after a relatively short period of time, the microorganisms can obtain its source of carbon and energy from asphaltens. The addition of metabolic co-substrates, like cow bed and potato peelings, allows the fragmentation of complex compounds into smaller structures, susceptible to further degradation. Afterwards, a maturation of the compost by means of a treatment with earthworms (Eisenia foetida) is necessary. Thus, through the vermicomposting it will be possible to obtain a valued product, useful in the processes of ground amendment, with little presence of asphaltens and occluded polycyclic aromatic hydrocarbons, rich in humus, and with an important bacterial flora of Bacillus genera, so that it can be typical of co-activators and accelerating products in composting processes. Along with this article, we show some parameters that control the evolution of the compost products (evolved gases, acidity, temperature and humidity); the chemical and microbiological analytical results; and the germination assays of vermicomposting. Results reveal that by using microorganisms living in either earthworm intestines (Stenotrophomonas maltophilia) or vermiculture substrates (Scedosporium apiospermium), it is possible to degrade and to eliminate the polycyclic asphaltens into CO(2) and H(2)O, helped by evaporation, dissolution and/or photo-oxidation processes. The obtained end product has contents of interesting vegetal nutrients and, mainly, it displays very high germination indices. PMID:17512195

  9. Antibacterial Activity of Salvadora persica L. (Miswak) Extracts against Multidrug Resistant Bacterial Clinical Isolates.

    PubMed

    Al-Ayed, Mohamed Saeed Zayed; Asaad, Ahmed Morad; Qureshi, Mohamed Ansar; Attia, Hany Goda; AlMarrani, Abduljabbar Hadi

    2016-01-01

    Much effort has focused on examining the inhibitory effect of Salvadora persica (miswak) on oral microorganisms, but information concerning its antibacterial activity against other human pathogens, particularly multidrug resistant (MDR) isolates, is scarce. Therefore, this study aimed to assess the in vitro antibacterial activities of Salvadora persica L. extracts against 10 MDR bacterial clinical isolates other than oral pathogens. The antibacterial activity of aqueous and methanol miswak extracts was assessed using the agar dilution and minimum inhibitory concentration (MIC) methods. Overall, the 400 mg/mL of miswak extract was the most effective on all strains. The methanol extract exhibited a stronger antibacterial activity against Gram-negative (3.3-13.6 mm) than Gram-positive (1.8-8.3 mm) bacteria. The lowest MIC value was seen for E. coli (0.39, 1.56 µg/mL), followed by Streptococcus pyogenes (1.56 µg/mL). The highest MIC value (6.25, 12.5 µg/mL) was recorded for methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumannii, and Stenotrophomonas maltophilia. This study demonstrates, for the first time, the moderate to strong antibacterial activity of miswak extracts against all tested MDR-pathogens. Methanol extract appears to be a potent antimicrobial agent that could be considered as complementary and alternative medicine against resistant pathogens. Further studies on a large number of MDR organisms are necessary to investigate and standardize the inhibitory effect of miswak extracts against these emerging pathogens. PMID:26904146

  10. Inoculation of paperboard mill sludge versus mixed culture bacteria for hydrogen production from paperboard mill wastewater.

    PubMed

    Farghaly, Ahmed; Tawfik, Ahmed; Danial, Amal

    2016-02-01

    A comparative evaluation of paperboard mill sludge (PMS) versus mixed culture bacteria (MCB) as inoculum for hydrogen production from paperboard mill wastewater (PMW) was investigated. The experiments were conducted at different initial cultivation pHs, inoculums to substrate ratios (ISRs gVS/gCOD), and hydraulic retention times (HRTs). The peak hydrogen yield (HY) of 5.29 ± 0.16 and 1.22 ± 0.11 mmol/gCODinitial was occurred at pH = 5 for MCB and PMS, respectively. At pH of 5, the HY and COD removal achieved the highest values of 2.26 ± 0.14 mmol/gCODinitial and 86 ± 1.6 % at ISR = 6 for MCB, and 2.38 ± 0.25 mmol/gCODinitial and 60.4 ± 2.5 % at ISRs = 3 for PMS. The maximum hydrogen production rate was 93.75 ± 8.9 mmol/day at HRT = 9.6 h from continuous upflow anaerobic reactor inoculated with MCB. Meanwhile, the 16S ribosomal RNA (rRNA) gene fragments indicated a dominance of a novel hydrogen-producing bacterium of Stenotrophomonas maltophilia for PMS microbial community. On the other hand, Escherichia fergusonii and Enterobacter hormaechei were the predominant species for MCB. PMID:26498965

  11. Identification of a Series of Tricyclic Natural Products as Potent Broad-Spectrum Inhibitors of Metallo-?-Lactamases

    PubMed Central

    Payne, David J.; Hueso-Rodrguez, Juan Antonio; Boyd, Helen; Concha, Nstor O.; Janson, Cheryl A.; Gilpin, Martin; Bateson, John H.; Cheever, Christy; Niconovich, Nancy L.; Pearson, Stewart; Rittenhouse, Stephen; Tew, David; Dez, Emilio; Prez, Paloma; de la Fuente, Jesus; Rees, Michael; Rivera-Sagredo, Alfonso

    2002-01-01

    This work describes the discovery and characterization of a novel series of tricyclic natural product-derived metallo-?-lactamase inhibitors. Natural product screening of the Bacillus cereus II enzyme identified an extract from a strain of Chaetomium funicola with inhibitory activity against metallo-?-lactamases. SB236050, SB238569, and SB236049 were successfully extracted and purified from this extract. The most active of these compounds was SB238569, which possessed Ki values of 79, 17, and 3.4 ?M for the Bacillus cereus II, Pseudomonas aeruginosa IMP-1, and Bacteroides fragilis CfiA metallo-?-lactamases, respectively, yet none of the compounds exhibited any inhibitory activity against the Stenotrophomonas maltophilia L-1 metallo-?-lactamase (50% inhibitory concentration > 1,000 ?M). The lack of activity against angiotensin-converting enzyme and serine ?-lactamases demonstrated the selective nature of these compounds. The crystal structure of SB236050 complexed in the active site of CfiA has been obtained to a resolution of 2.5 . SB236050 exhibits key polar interactions with Lys184, Asn193, and His162 and a stacking interaction with the indole ring of Trp49 in the flap, which is in the closed conformation over the active site groove. SB236050 and SB238569 also demonstrate good antibacterial synergy with meropenem. Eight micrograms of SB236050 per ml gave rise to an eightfold drop in the MIC of meropenem for two clinical isolates of B. fragilis producing CfiA, making these strains sensitive to meropenem (MIC ? 4 ?g/ml). Consequently, this series of metallo-?-lactamase inhibitors exhibit the most promising antibacterial synergy activity so far observed against organisms producing metallo-?-lactamases. PMID:12019104

  12. [The first experience of application of PCR techniques in real-time mode to diagnose bacteriemia during postoperational period in cardiosurgery patients].

    PubMed

    Popov, D A; Vostrikova, T Iu

    2011-08-01

    The results comparison is made between PCR polymerase chain reaction techniques in real-time mode and cultural techniques of analysis of blood samples in patients with suspicion of bacteriemia during early postoperational period. From September to December 2009 43 blood samples from 37 adult patients aged 59+9.2 years were analyzed on suspicion of bacteriemia. The blood samples for PCR analysis (SeptiFast technique Roche diagnostics, Switzerland) were taken parallel to the inoculation. Among 43 samples 20 (46.5%) were positive. The species structure of identified germs was as follows: Enteroccocus Faecalis - 2, Klebsiella pneumonia - 2, Enteroccocusfaecium - 1, Pseudomonas aeruginosa - 2, coagulase negative Staphilococcus - 11. All cases of seeding of coagulase negative Staphilococcus were interpreted using PCR techniques as negative or contamination. In four cases a full matching of results of compared techniques was obtained. In cases when hemoculture was negative (n = 23) the PCR techniques permitted to detect two positive results (Staphilococcus spp. and Stenotrophomonas maltophilia). In three cases of positive hemoculture the PCR techniques brought negative result and at that in two cases the causative agents (Pseudomonas fluorescens and Ralstonia mannitolilytica) were out of specter of pathogens detected by this method. The PCR techniques in real-time mode permit to reduce significantly time of pathogen investigation and to detect the false positive results conditioned by contamination. This techniques has to be applied in parallel with cultural technique because only this approach provide a possibility to get the clinically needed data related to the sensitivity of causative agent to antibacterial preparations. PMID:22164420

  13. Microbial Contamination of Glaucoma Eyedrops Used by Patients Compared With Ocular Medications Used in the Hospital

    PubMed Central

    Teuchner, Barbara; Wagner, Julia; Bechrakis, Nikolaos E.; Orth-Höller, Dorothea; Nagl, Markus

    2015-01-01

    Abstract The aim of this study was to compare the percentage of contamination of multiuse eyedrops applied by glaucoma patients at home and by the medical personnel at the outpatient department, the ward, and the operating room of our Department of Ophthalmology. Eyedrops were collected over a period of 11 months. Samples were taken from the dropper tip (smear), drops, and the residual fluid inside the bottle and cultivated on blood agar. Colony forming units were counted and identified by mass spectrometry. The percentage of contamination was significantly higher in eyedrops applied by the patients (29/119; 24.4%, P < 0.01), used in the ward (26/133; 19.5%, P < 0.01), and in the outpatient unit (6/35; 17.1%, P = 0.036) compared with that in the operating room (6/113; 5.3%). The median period of use was 1 week in the operating room compared with 4 weeks in the other groups (P < 0.01). Glaucoma medications were significantly more frequently contaminated than antibiotic and anesthetic eyedrops (P < 0.05). For eyedrops applied by the patients, the tip was more frequently contaminated than the drops and the residual internal fluid. For eyedrops from the ward, the opposite was true. Pathogenic strains (Pseudomonas aeruginosa, Serratia marcescens, Acinetobacter lwoffii, Stenotrophomonas maltophilia, and Staphylococcus aureus) were found only in 6 bottles (1.5%), whereas most of the detected microbes belonged to human or environmental flora. This study underlines the importance of hygienic handling of eyedrops and raises the question of whether single-use glaucoma medication might be preferred to reduce the risk of contamination. PMID:25715262

  14. Molecular and Biochemical Heterogeneity of Class B Carbapenem-Hydrolyzing β-Lactamases in Chryseobacterium meningosepticum

    PubMed Central

    Bellais, Samuel; Aubert, Daniel; Naas, Thierry; Nordmann, Patrice

    2000-01-01

    Although the carbapenem-hydrolyzing β-lactamase (CHβL) BlaB-1 is known to be in Chryseobacterium meningosepticum NCTC 10585, a second CHβL gene, blaGOB-1, was cloned from another C. meningosepticum clinical isolate (PINT). The G+C content of blaGOB-1 (36%) indicated the likely chromosomal origin of this gene. Its expression in Escherichia coli DH10B yields a mature CHβL with a pI of 8.7 and a relative molecular mass of 28.2 kDa. In E. coli, GOB-1 conferred resistance to narrow-spectrum cephalosporins and reduced susceptibility to ureidopenicillins, broad-spectrum cephalosporins, and carbapenems. GOB-1 had a broad-spectrum hydrolysis profile including penicillins and cephalosporins (but not aztreonam). The catalytic efficiency for meropenem was higher than for imipenem. GOB-1 had low amino acid identity with the class B CHβLs, sharing 18% with the closest, L-1 from Stenotrophomonas maltophilia, and only 11% with BlaB-1. Most of the conserved amino acids that may be involved in the active site of CHβLs (His-101, Asp-103, His-162, and His-225) were identified in GOB-1. Sequence heterogeneity was found for GOB-1-like and BlaB-1-like β-lactamases, having 90 to 100% and 86 to 100% amino acid identity, respectively, among 10 unrelated C. meningosepticum isolates. Each isolate had a GOB-1-like and a BlaB-1-like gene. The same combination of GOB-1-like and BlaB-1-like β-lactamases was not found in two different isolates. C. meningosepticum is a bacterial species with two types of unrelated chromosome-borne class B CHβLs that can be expressed in E. coli and, thus, may represent a clinical threat if spread in gram-negative aerobes. PMID:10858348

  15. Antimicrobial activity of novel nanostructured Cu-SiO2 coatings prepared by chemical vapour deposition against hospital related pathogens

    PubMed Central

    2013-01-01

    There is increasing recognition that the healthcare environment acts as an important reservoir for transmission of healthcare acquired infections (HCAI). One method of reducing environmental contamination would be use of antimicrobial materials. The antimicrobial activity of thin silica-copper films prepared by chemical vapour deposition was evaluated against standard strains of bacteria used for disinfectant testing and bacteria of current interest in HCAI. The structure of the coatings was determined using Scanning Electron Microscopy and their hardness and adhesion to the substrate determined. Antimicrobial activity was tested using a method based on BS ISO 22196:2007. The coatings had a pale green-brown colour and had a similar hardness to steel. SEM showed nano-structured aggregates of Cu within a silica matrix. A log10 reduction in viability of >5 could be obtained within 4 h for the disinfectant test strains and within 6 h for producing Acinetobacter baumannii, Klebsiella pneumoniae and Stenotrophomonas maltophilia. Activity against the other hospital isolates was slower but still gave log10 reduction factors of >5 for extended spectrum β-lactamase producing Escherichia coli and >3 for vancomycin resistant Enterococcus faecium, methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa within 24 h. The results demonstrate the importance of testing antimicrobial materials destined for healthcare use against isolates of current interest in hospitals as well as standard test strains. The coatings used here can also be applied to substrates such as metals and ceramics and have potential applications where reduction of microbial environmental contamination is desirable. PMID:24007899

  16. Prevalence of infectious pathogens in Crohn's disease.

    PubMed

    Knösel, Thomas; Schewe, Christiane; Petersen, Nanni; Dietel, Manfred; Petersen, Iver

    2009-01-01

    The importance of infectious pathogens in Crohn's disease (CD) is still under debate. Therefore, we examined a panel of potential viral and bacterial pathogens in a large series of CD patients and controls. Archival tissue from 76 patients, 56 with CD and 20 control patients, with normal colon mucosa (n=10) and non-steroid anti-inflammatory drug (NSAID)-induced colitis (n=10) were examined using PCR-based detection methods for human cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus 1, 2 (HSV1,2), adenovirus (AD), varicella-zoster virus (VZV), human herpes virus 6 (HHV6), human herpes virus 8 (HHV8), Mycobacterium tuberculosis complex (Mtbc), atypical mycobacteria (nM/MG1), including Mycobacterium avium (subspecies paratuberculosis, MAP), Stenotrophomonas maltophilia (Sm), and Yersinia enterocolitica (Ye). In CD patients, positive PCR results were achieved in 19 cases (34%). Sm was most frequent in 10 of 56 cases (17.9%) followed by EBV (6/56, 10.7%), nM/MG1 (4/56, 7.1%), including MAP, HHV6, and CMV (2/56, 3.6%), and finally Mtbc and AD (1/56, 1.8%). The control patients showed positive PCR results in 12 patients (12/20, 60%), nine of them with only weak signals, suggesting a persistent infection. In addition, we compared typical pathomorphological features of CD patients with the PCR results and found a significant correlation between EBV infection and mural abscesses (P=0.014). Our data demonstrate that several potential pathogens can be detected in a sizeable fraction of specimens from patients with CD, but also in control patients, suggesting that the analyzed infectious pathogens may be associated with the disease, but do not represent an obligatory cause. PMID:19186006

  17. Biosynthesis and structural characterization of silver nanoparticles from bacterial isolates

    SciTech Connect

    Zaki, Sahar; El Kady, M.F.; Abd-El-Haleem, Desouky

    2011-10-15

    Graphical abstract: In this study five bacterial isolates belong to different genera were found to be able to biosynthesize silver nanoparticles. Biosynthesis and spectral characterization are reported here. Highlights: {yields} About 300 bacterial isolates were screened for their ability to produce nanosilvers {yields} Five of them were potential candidates for synthesis of silver nanoparticles {yields} Production of silver nanoparticles was examined using UV-Vis, XRD, SEM and EDS. {yields} The presence of nanoparticles with all five bacterial isolates was confirmed. -- Abstract: This study aimed to develop a green process for biosynthesis of silver nanomaterials by some Egyptian bacterial isolates. This target was achieved by screening an in-house culture collection consists of 300 bacterial isolates for silver nanoparticle formation. Through screening process, it was observed that strains belonging to Escherichia coli (S30, S78), Bacillus megaterium (S52), Acinetobacter sp. (S7) and Stenotrophomonas maltophilia (S54) were potential candidates for synthesis of silver nanoparticles. The extracellular production of silver nanoparticles by positive isolates was investigated by UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results demonstrated that UV-visible spectrum of the aqueous medium containing silver ion showed a peak at 420 nm corresponding to the plasmon absorbance of silver nanoparticles. Scanning electron microscopy micrograph showed formation of silver nanoparticles in the range of 15-50 nm. XRD-spectrum of the silver nanoparticles exhibited 2{theta} values corresponding to the silver nanocrystal that produce in hexagonal and cubic crystal configurations with different plane of orientation. In addition, the signals of the silver atoms were observed by EDS-spectrum analysis that confirms the presence of silver nanoparticles (AgNPs) in all positive bacterial isolates.

  18. Effective Cohorting and “Superisolation” in a Single Intensive Care Unit in Response to an Outbreak of Diverse Multi-Drug-Resistant Organisms

    PubMed Central

    Hranjec, Tjasa; Politano, Amani D.; Swenson, Brian R.; Metzger, Rosemarie; Bonatti, Hugo; Sawyer, Robert G.

    2011-01-01

    Abstract Background Cohorting patients in dedicated hospital wards or wings during infection outbreaks reduces transmission of organisms, yet frequently, this may not be feasible because of inadequate capacity, especially in the intensive care unit (ICU). We hypothesized that cohorting isolation patients in one geographic location in a single ICU and using enhanced isolation procedures (“superisolation”) can prevent the further spread of highly multi-drug-resistant organisms (MDRO). Methods Six patients dispersed throughout our Surgical Trauma Burn ICU had infections with carbapenem-resistant, non-clonal gram-negative MDRO, namely Klebsiella pneumoniae, Citrobacter freundii, Stenotrophomonas maltophilia, Aeromonas hydrophilia, Proteus mirabilis, Pseudomonas aeruginosa, and Providencia rettgeri. Five of the six patients also had simultaneous isolation of vancomycin-resistant enterococci (VRE). Under threat of unit closure and after all standard isolation procedures had been enacted, these six patients were moved to the front six beds of the unit, the front entrance was closed, and all traffic was redirected through the back entrance. Nursing staff were assigned to either two isolation or two non-isolation patients. In accordance with the practice of Semmelweis, rounds were conducted so as to end at the rooms of the patients with the most highly-resistant bacterial infections. Results A few months after these interventions, all six patients had been discharged from the ICU (three alive and three dead), and no new cases of infection with any of their pathogens (based on species and antibiogram) or VRE occurred. The mean ICU stay and overall hospital length of stay for these six patients were 78.3 days and 117.2 days respectively, with a mortality rate of 50%. Conclusion Cohorting patients to one area and altering work routines to minimize contact with patients with MDRO (essentially designating a “high-risk” zone) may be beneficial in stopping patient-to-patient spread of highly resistant bacteria without the need for a dedicated isolation unit. PMID:21936667

  19. Microbe associated molecular patterns from rhizosphere bacteria trigger germination and Papaver somniferum metabolism under greenhouse conditions.

    PubMed

    Bonilla, A; Sarria, A L F; Algar, E; Muñoz Ledesma, F J; Ramos Solano, B; Fernandes, J B; Gutierrez Mañero, F J

    2014-01-01

    Ten PGPR from different backgrounds were assayed on Papaver somniferum var. Madrigal to evaluate their potential as biotic elicitors to increase alkaloid content under the rationale that some microbe associated molecular patterns (MAMPs) are able to trigger plant metabolism. First, the 10 strains and their culture media at two different concentrations were tested for their ability to trigger seed germination. Then, the best three strains were tested for their ability to increase seedling growth and alkaloid levels under greenhouse conditions. Only three strains and their culture media enhanced germination. Then, germination enhancing capacity of these best three strains, N5.18 Stenotrophomonas maltophilia, Aur9 Chryseobacterium balustinum and N21.4 Pseudomonas fluorescens was evaluated in soil. Finally, the three strains were applied on seedlings at two time points, by soil drench or by foliar spray. Photosynthesis was measured, plant height was recorded, capsules were weighted and alkaloids analyzed by HPLC. Only N5.18 delivered by foliar spray significantly increased plant height coupled to an increase in total alkaloids and a significant increase in opium poppy straw dry weight; these increases were supported by a better photosynthetic efficiency. The relative contents of morphine, thebaine, codeine and oripavine were affected by this treatment causing a significant increase in morphine coupled to a decrease in thebaine, demonstrating the effectivity of MAMPs from N5.18 in this plant species. Considering the increase in capsule biomass and alkaloids together with the acceleration of germination, strain N5.18 appears as a good candidate to elicit plant metabolism and consequently, to increase productivity of Papaver somniferum. PMID:24296249

  20. Diversity of bacteria nesting the plant cover of north Sinai deserts, Egypt.

    PubMed

    Hanna, Amira L; Youssef, Hanan H; Amer, Wafaa M; Monib, Mohammed; Fayez, Mohammed; Hegazi, Nabil A

    2013-01-01

    North Sinai deserts were surveyed for the predominant plant cover and for the culturable bacteria nesting their roots and shoots. Among 43 plant species reported, 13 are perennial (e.g. Fagonia spp., Pancratium spp.) and 30 annuals (e.g. Bromus spp., Erodium spp.). Eleven species possessed rhizo-sheath, e.g. Cyperus capitatus, Panicum turgidum and Trisetaria koelerioides. Microbiological analyses demonstrated: the great diversity and richness of associated culturable bacteria, in particular nitrogen-fixing bacteria (diazotrophs); the majority of bacterial residents were of true and/or putative diazotrophic nature; the bacterial populations followed an increasing density gradient towards the root surfaces; sizeable populations were able to reside inside the root (endorhizosphere) and shoot (endophyllosphere) tissues. Three hundred bacterial isolates were secured from studied spheres. The majority of nitrogen-fixing bacilli isolates belonged to Bacillus megaterium, Bacillus pumilus, Bacillus polymexa, Bacillus macerans, Bacillus circulans and Bacillus licheniformis. The family Enterobacteriaceae represented by Enterobacter agglomerans, Enterobacter sackazakii, Enterobacter cloacae, Serratia adorifera, Serratia liquefaciens and Klebsiella oxytoca. The non-Enterobacteriaceae population was rich in Pantoae spp., Agrobacterium rdiobacter, Pseudomonas vesicularis, Pseudomonas putida, Stenotrophomonas maltophilia, Ochrobactrum anthropi, Sphingomonas paucimobilis and Chrysemonas luteola. Gluconacetobacter diazotrophicus were reported inside root and shoot tissues of a number of tested plants. The dense bacterial populations reported speak well to the very possible significant role played by the endophytic bacterial populations in the survival, in respect of nutrition and health, of existing plants. Such groups of diazotrophs are good candidates, as bio-preparates, to support the growth of future field crops grown in deserts of north Sinai and irrigated by the water of El-Salam canal. PMID:25685397

  1. Microbial Diversity in the Early In Vivo-Formed Dental Biofilm.

    PubMed

    Heller, D; Helmerhorst, E J; Gower, A C; Siqueira, W L; Paster, B J; Oppenheim, F G

    2016-01-01

    Although the mature dental biofilm composition is well studied, there is very little information on the earliest phase of in vivo tooth colonization. Progress in dental biofilm collection methodologies and techniques of large-scale microbial identification have made new studies in this field of oral biology feasible. The aim of this study was to characterize the temporal changes and diversity of the cultivable and noncultivable microbes in the early dental biofilm. Samples of early dental biofilm were collected from 11 healthy subjects at 0, 2, 4, and 6 h after removal of plaque and pellicle from tooth surfaces. With the semiquantitative Human Oral Microbiome Identification Microarray (HOMIM) technique, which is based on 16S rRNA sequence hybridizations, plaque samples were analyzed with the currently available 407 HOMIM microbial probes. This led to the identification of at least 92 species, with streptococci being the most abundant bacteria across all time points in all subjects. High-frequency detection was also made with Haemophilus parainfluenzae, Gemella haemolysans, Slackia exigua, and Rothia species. Abundance changes over time were noted for Streptococcus anginosus and Streptococcus intermedius (P = 0.02), Streptococcus mitis bv. 2 (P = 0.0002), Streptococcus oralis (P = 0.0002), Streptococcus cluster I (P = 0.003), G. haemolysans (P = 0.0005), and Stenotrophomonas maltophilia (P = 0.02). Among the currently uncultivable microbiota, eight phylotypes were detected in the early stages of biofilm formation, one belonging to the candidate bacterial division TM7, which has attracted attention due to its potential association with periodontal disease. PMID:26746720

  2. Discrepancy in MALDI-TOF MS identification of uncommon Gram-negative bacteria from lower respiratory secretions in patients with cystic fibrosis

    PubMed Central

    AbdulWahab, Atqah; Taj-Aldeen, Saad J; Ibrahim, Emad Bashir; Talaq, Eman; Abu-Madi, Marawan; Fotedar, Rashmi

    2015-01-01

    Introduction Early identification of microbial organisms from respiratory secretions of patients with cystic fibrosis (CF) is important to guide therapeutic decisions. The objective was to compare the accuracy of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) relative to the conventional phenotypic method in identifying common bacterial isolates, including nonfermenting Gram-negative bacteria, in a cohort of patients with CF. Methods A total of 123 isolates from 50 patients with CF representing 14 bacterial species from respiratory specimens were identified using MALDI-TOF MS in parallel with conventional phenotypic methods. Discrepancies were confirmed by 16S ribosomal RNA (rRNA) gene sequencing in five Gram-negative isolates. Results The MALDI-TOF MS managed to identify 122/123 (99.2%) bacterial isolates to the genus level and 118/123 (95.9%) were identified to the species level. The MALDI-TOF MS results were 100% consistent to the species level with conventional phenotypic identification for isolates of Staphylococcus aureus, Pseudomonas aeruginosa, Haemophilus influenzae, Streptococcus pyogenes, Achromobacter xylosoxidans, Stenotrophomonas maltophilia, and other uncommon organisms such as Chryseobacterium gleum and Enterobacter cloacae. The 5/123 (4.6%) isolates misidentified were all Gram-negative bacteria. The isolation of E. cloacae and Haemophilus paraphrohaemolyticus may extend the potentially pathogenic list of organisms isolated from patients with CF. Conclusion Although the technique provides an early identification and antimicrobial therapy approach in patients with CF, limitation in the diagnosis of uncommon Gram-negative bacteria may exist. PMID:25995646

  3. Enhancement of the catalytic efficiency and thermostability of Stenotrophomonas sp. keratinase KerSMD by domain exchange with KerSMF.

    PubMed

    Fang, Zhen; Zhang, Juan; Liu, Baihong; Du, Guocheng; Chen, Jian

    2016-01-01

    In this study, we enhanced the catalytic efficiency and thermostability of keratinase KerSMD by replacing its N/C-terminal domains with those from a homologous protease, KerSMF, to degrade feather waste. Replacement of the N-terminal domain generated a mutant protein with more than twofold increased catalytic activity towards casein. Replacement of the C-terminal domain obviously improved keratinolytic activity and increased the kcat /Km value on a synthetic peptide, succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, by 54.5%. Replacement of both the N- and C-terminal domains generated a more stable mutant protein, with a Tm value of 64.60 ± 0.65°C and a half-life of 244.6 ± 2 min at 60°C, while deletion of the C-terminal domain from KerSMD or KerSMF resulted in mutant proteins exhibiting high activity under mesophilic conditions. These findings indicate that the pre-peptidase C-terminal domain and N-propeptide are not only important for substrate specificity, correct folding and thermostability but also support the ability of the enzyme to convert feather waste into feed additives. PMID:26552936

  4. Persistence of microbial communities including Pseudomonas aeruginosa in a hospital environment: a potential health hazard

    PubMed Central

    2014-01-01

    Background The persistence of microbial communities and how they change in indoor environments is of immense interest to public health. Moreover, hospital acquired infections are significant contributors to morbidity and mortality. Evidence suggests that, in hospital environments agent transfer between surfaces causes healthcare associated infections in humans, and that surfaces are an important transmission route and may act as a reservoir for some of the pathogens. This study aimed to evaluate the diversity of microorganisms that persist on noncritical equipment and surfaces in a main hospital in Portugal, and are able to grow in selective media for Pseudomonas, and relate them with the presence of Pseudomonas aeruginosa. Results During 2 years, a total of 290 environmental samples were analyzed, in 3 different wards. The percentage of equipment in each ward that showed low contamination level varied between 22% and 38%, and more than 50% of the equipment sampled was highly contaminated. P. aeruginosa was repeatedly isolated from sinks (10 times), from the taps’ biofilm (16 times), and from the showers and bedside tables (two times). Two ERIC clones were isolated more than once. The contamination level of the different taps analyzed showed correlation with the contamination level of the hand gels support, soaps and sinks. Ten different bacteria genera were frequently isolated in the selective media for Pseudomonas. Organisms usually associated with nosocomial infections as Stenotrophomonas maltophilia, Enterococcus feacalis, Serratia nematodiphila were also repeatedly isolated on the same equipment. Conclusions The environment may act as a reservoir for at least some of the pathogens implicated in nosocomial infections. The bacterial contamination level was related to the presence of humidity on the surfaces, and tap water (biofilm) was a point of dispersion of bacterial species, including potentially pathogenic organisms. The materials of the equipment sampled could not be related to the microbial contamination level. The presence of a disinfectant in the isolation medium suggests that the number of microorganism in the environment could be higher and shows the diversity of disinfectant resistant species. The statistical analysis suggests that the presence of bacteria could increase the risk of transmission by hand manipulation. PMID:24885173

  5. Trends in the Susceptibility of Clinically Important Resistant Bacteria to Tigecycline: Results from the Tigecycline In Vitro Surveillance in Taiwan Study, 2006 to 2010

    PubMed Central

    Chen, Yen-Hsu; Lu, Po-Liang; Huang, Cheng-Hua; Liao, Chun-Hsing; Lu, Chin-Te; Chuang, Yin-Ching; Tsao, Shih-Ming; Chen, Yao-Shen; Liu, Yung-Ching; Chen, Wei-Yu; Jang, Tsrang-Neng; Lin, Hsiu-Chen; Chen, Chih-Ming; Shi, Zhi-Yuan; Pan, Sung-Ching; Yang, Jia-Ling; Kung, Hsiang-Chi; Liu, Chun-Eng; Cheng, Yu-Jen; Liu, Jien-Wei; Sun, Wu; Wang, Lih-Shinn; Ko, Wen-Chien; Yu, Kwok-Woon; Chiang, Ping-Cherng; Lee, Ming-Hsun; Lee, Chun-Ming; Hsu, Gwo-Jong

    2012-01-01

    The Tigecycline In Vitro Surveillance in Taiwan (TIST) study, a nationwide, prospective surveillance during 2006 to 2010, collected a total of 7,793 clinical isolates, including methicillin-resistant Staphylococcus aureus (MRSA) (n = 1,834), penicillin-resistant Streptococcus pneumoniae (PRSP) (n = 423), vancomycin-resistant enterococci (VRE) (n = 219), extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (n = 1,141), ESBL-producing Klebsiella pneumoniae (n = 1,330), Acinetobacter baumannii (n = 1,645), and Stenotrophomonas maltophilia (n = 903), from different specimens from 20 different hospitals in Taiwan. MICs of tigecycline were determined following the criteria of the U.S. Food and Drug Administration (FDA) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST-2011). Among drug-resistant Gram-positive pathogens, all of the PRSP isolates were susceptible to tigecycline (MIC90, 0.03 μg/ml), and only one MRSA isolate (MIC90, 0.5 μg/ml) and three VRE isolates (MIC90, 0.125 μg/ml) were nonsusceptible to tigecycline. Among the Gram-negative bacteria, the tigecycline susceptibility rates were 99.65% for ESBL-producing E. coli (MIC90, 0.5 μg/ml) and 96.32% for ESBL-producing K. pneumoniae (MIC90, 2 μg/ml) when interpreted by FDA criteria but were 98.7% and 85.8%, respectively, when interpreted by EUCAST-2011 criteria. The susceptibility rate for A. baumannii (MIC90, 4 μg/ml) decreased from 80.9% in 2006 to 55.3% in 2009 but increased to 73.4% in 2010. A bimodal MIC distribution was found among carbapenem-susceptible A. baumannii isolates, and a unimodal MIC distribution was found among carbapenem-nonsusceptible A. baumannii isolates. In Taiwan, tigecycline continues to have excellent in vitro activity against several major clinically important drug-resistant bacteria, with the exception of A. baumannii. PMID:22203598

  6. Bacterial constituents of indoor air in a high throughput building in the tropics.

    PubMed

    Li, Tee Chin; Ambu, Stephen; Mohandas, Kavitha; Wah, Mak Joon; Sulaiman, Lokman Hakim; Murgaiyah, Malathi

    2014-09-01

    Airborne bacteria are significant biotic constituents of bioaerosol. Bacteria at high concentrations in the air can compromise indoor air quality (IAQ) and result in many diseases. In tropical environments like Malaysia that extensively utilize air-conditioning systems, this is particularly significant due to continuous recirculation of indoor air and the potential implications for human health. Currently, there is a lack of knowledge regarding the impact of airborne bacteria on IAQ in Malaysia. This study was prompted by a need for reliable baseline data on airborne bacteria in the indoor environment of tropical equatorial Malaysia, that may be used as a reference for further investigations on the potential role played by airborne bacteria as an agent of disease in this region. It was further necessitated due to the threat of bioterrorism with the potentiality of release of exotic pathogenic microorganisms into indoor or outdoor air. Before scientists can detect the latter, a gauge of the common microorganisms in indoor (as well as outdoor) air needs to be ascertained, hence the expediency of this study. Bacterial counts from the broad-based and targeted study were generally in the order of 10(2) colony-forming units (CFU) per m(3) of air. The most prevalent airborne bacteria found in the broad-based study that encompassed all five levels of the building were Gram-positive cocci (67.73%), followed by Gram-positive rods (24.26%) and Gram-negative rods (7.10%). Gram-negative cocci were rarely detected (0.71%). Amongst the genera identified, Kytococcus sp., Micrococcus sp., Staphylococcus sp., Leifsonia sp., Bacillus sp. and Corynebacterium sp. predominated in indoor air. The most dominant bacterial species were Kytococcus sedentarius, Staphylococcus epidermidis and Micrococcus luteus. The opportunistic and nosocomial pathogen, Stenotrophomonas maltophilia was also discovered at a high percentage in the cafeteria. The bacteria isolated in this study have been increasingly documented to cause opportunistic infections in immuno-compromised patients, sometimes with fatal outcomes. Furthermore, some of them are becoming increasingly resistant to antibiotics. Hence, we propose that indoor reservoirs of these bacteria and their associated clinical and more subtle health effects, if any, be investigated further. PMID:25382482

  7. Ceftobiprole activity against over 60,000 clinical bacterial pathogens isolated in Europe, Turkey, and Israel from 2005 to 2010.

    PubMed

    Farrell, David J; Flamm, Robert K; Sader, Helio S; Jones, Ronald N

    2014-07-01

    Ceftobiprole medocaril is a newly approved drug in Europe for the treatment of hospital-acquired pneumonia (HAP) (excluding patients with ventilator-associated pneumonia but including ventilated HAP patients) and community-acquired pneumonia in adults. The aim of this study was to evaluate the in vitro antimicrobial activity of ceftobiprole against prevalent Gram-positive and -negative pathogens isolated in Europe, Turkey, and Israel during 2005 through 2010. A total of 60,084 consecutive, nonduplicate isolates from a wide variety of infections were collected from 33 medical centers. Species identification was confirmed, and all isolates were susceptibility tested using reference broth microdilution methods. Ceftobiprole had high activity against methicillin-susceptible Staphylococcus aureus (MSSA) (100.0% susceptible), methicillin-susceptible coagulase-negative staphylococci (CoNS), beta-hemolytic streptococci, and Streptococcus pneumoniae (99.3% susceptible), with MIC90 values of 0.25, 0.12, ≤ 0.06, and 0.5 μg/ml, respectively. Ceftobiprole was active against methicillin-resistant S. aureus (MRSA) (98.3% susceptible) and methicillin-resistant CoNS, having a MIC90 of 2 μg/ml. Ceftobiprole was active against Enterococcus faecalis (MIC50/90, 0.5/4 μg/ml) but not against most Enterococcus faecium isolates. Ceftobiprole was very potent against the majority of Enterobacteriaceae (87.3% susceptible), with >80% inhibited at ≤ 0.12 μg/ml. The potency of ceftobiprole against Pseudomonas aeruginosa (MIC50/90, 2/>8 μg/ml; 64.6% at MIC values of ≤ 4 μg/ml) was similar to that of ceftazidime (MIC50/90, 2/>16 μg/ml; 75.4% susceptible), but limited activity was observed against Acinetobacter spp. and Stenotrophomonas maltophilia. High activity was also observed against all Haemophilus influenzae (MIC90, ≤ 0.06 μg/ml) and Moraxella catarrhalis (MIC50/90, ≤ 0.06/0.25 μg/ml) isolates. Ceftobiprole demonstrated a wide spectrum of antimicrobial activity against this very large longitudinal sample of contemporary pathogens. PMID:24777091

  8. In vivo development of daptomycin resistance in vancomycin-susceptible methicillin-resistant Staphylococcus aureus severe infections previously treated with glycopeptides.

    PubMed

    Capone, A; Cafiso, V; Campanile, F; Parisi, G; Mariani, B; Petrosillo, N; Stefani, S

    2016-04-01

    Our aim was to describe the clinical and microbiological features of four cases of severe vancomycin-susceptible methicillin-resistant Staphylococcus aureus (MRSA) infections in which the vancomycin non-susceptibility development and daptomycin resistance occurred under therapy with teicoplanin (three cases) and daptomycin switched to vancomycin (one case). Clinical data were retrospectively reviewed. On nine clinical epidemiologically unrelated daptomycin-susceptible (DAP-S) and daptomycin-resistant (DAP-R) MRSA, we performed: (i) DAP-VAN-TEC-CFX-RIF minimum inhibitory concentrations (MICs); (ii) glycopeptide resistance detection (GRD) by δ-hemolysis; (iii) glycopeptide population analysis; (iv) molecular characterization by PFGE-MLST-SCCmec-agr-typing; (v) rpoB and mprF single nucleotide polymorphisms (SNPs); (vi) dltA-mprF-atl-sceD expression by real-time quantitative polymerase chain reaction (qPCR). Three out of the four patients did not survive despite salvage treatment; two died with active MRSA infection and one died because of Stenotrophomonas maltophilia sepsis. The fourth patient, in which a reversion to a DAP-S phenotype occurred, survived with daptomycin plus trimethoprim/sulfamethoxazole and oxacillin treatment, and endovascular device removal. Daptomycin resistance development was preceded by a stable heterogeneous vancomycin-intermediate S. aureus (hVISA) or VISA phenotype acquisition, while in one case, daptomycin resistance was preceded by an unstable daptomycin heteroresistance (hDAP) behavior reverting to DAP-S during vancomycin plus rifampin therapy followed by high doses of daptomycin. All DAP-R strains showed hVISA or DAP-R traits, including mutations and/or up-regulation of genes involved in cell wall turnover and cell membrane perturbation. In our study, daptomycin resistance arose during glycopeptide therapy. The emergence of DAP-R isolates was preceded by a stable VISA or hVISA phenotype or by instability reverting to a DAP-S heteroresistant phenotype. Daptomycin, as first-line therapy for the treatment of severe MRSA infections, should be used at optimal dosage combined with other agents such as beta-lactams, to prevent daptomycin resistance occurrence. PMID:26815434

  9. Prevalence of Resistant Gram-Negative Bacilli in Bloodstream Infection in Febrile Neutropenia Patients Undergoing Hematopoietic Stem Cell Transplantation: A Single Center Retrospective Cohort Study.

    PubMed

    Wang, Ling; Wang, Ying; Fan, Xing; Tang, Wei; Hu, Jiong

    2015-11-01

    Bloodstream infection (BSI) is an important cause of morbidity and mortality in patients undergoing hematopoietic stem cell transplantation (HSCT). To evaluate the causative bacteria and identify risk factors for BSI associated mortality in febrile neutropenia patients undergoing HSCT, we collected the clinical and microbiological data from patients underwent HSCT between 2008 and 2014 and performed a retrospective analysis. Throughout the study period, among 348 episodes of neutropenic fever in patients underwent HSCT, 89 episodes in 85 patients had microbiological defined BSI with a total of 108 isolates. Gram-negative bacteria (GNB) were the most common isolates (76, 70.3%) followed by gram-positive bacteria (GPB, 29, 26.9%) and fungus (3, 2.8%). As to the drug resistance, 26 multiple drug resistance (MDR) isolates were identified. Resistant isolates (n = 23) were more common documented in GNB, mostly Escherichia coli (9/36, 25%) and Klebsiella pneumonia (6/24, 25%). A total of 12 isolated were resistant to carbapenem including 4 K pneumoniae (4/24, 16.7%), 3 Stenotrophomonas maltophilia, and 1 Pseudomonas aeruginosa and other 4 GNB isolates (Citrobacter freumdii, Pseudomonas stutzeri, Acinetobacter baumanii, and Chryseobacterium indologenes). As to the GPB, only 3 resistant isolates were documented including 2 methicillin-resistant isolates (Staphylococcus hominis and Arcanobacterium hemolysis) and 1 vancomycin-resistant Enterococcus faecium. Among these 85 patients with documented BSI, 11 patients died of BSI as primary or associated cause with a BSI-related mortality of 13.1 ± 3.7% and 90-day overall survival after transplantation at 80.0 ± 4.3%. Patients with high-risk disease undergoing allo-HSCT, prolonged neutropenia (≥15 days) and infection with carbapenem-resistant GNB were associated with BSI associated mortality in univariate and multivariate analyses. Our report revealed a prevalence of GNB in BSI of neutropenic patients undergoing HSCT. Patients with high-risk diseases with prolonged neutropenia and carbapenem-resistant GNB were independent risk factors for BSI-related mortality. PMID:26559260

  10. Update on Acinetobacter species: mechanisms of antimicrobial resistance and contemporary in vitro activity of minocycline and other treatment options.

    PubMed

    Castanheira, Mariana; Mendes, Rodrigo E; Jones, Ronald N

    2014-12-01

    Among Acinetobacter species, A. baumannii and other closely related species are commonly implicated in nosocomial infections. These organisms are usually multidrug resistant (MDR), and therapeutic options to treat A. baumannii infections are very limited. Clinicians have been resorting to older antimicrobial agents to treat infections caused by MDR A. baumannii, and some of these agents have documented toxicity and/or are not optimized for the infection type to be treated. Recent clinical experience supported by antimicrobial susceptibility data suggests that minocycline has greater activity than other tetracyclines and glycylcyclines against various MDR pathogens that have limited therapeutic options available, including Acinetobacter species. An intravenous formulation of minocycline has recently become available for clinical use, and in contrast to most older tetracyclines, minocycline has high activity against Acinetobacter species. In this report, we summarized some of the characteristics of the tetracycline class, and quantified the minocycline activity against contemporary (2007-2011) isolates and its potential therapeutic role against a collection of 5477 A. baumannii and other relevant gram-negative organisms when compared directly with tetracycline, doxycycline, and other broad-spectrum antimicrobial agents. Acinetobacter baumannii strains were highly resistant to all agents tested, with the exception of minocycline (79.1% susceptible) and colistin (98.8% susceptible). Minocycline (minimum inhibitory concentration that inhibits 50% and 90% of the isolates [MIC(50/90)]: 1/8 µg/mL) displayed greater activity than doxycycline (MIC(50/90): 2/>8 µg/mL) and tetracycline hydrochloride (HCL) (only 30.2% susceptible) against A. baumannii isolates, and was significantly more active than other tetracyclines against Burkholderia cepacia, Escherichia coli, Serratia marcescens, and Stenotrophomonas maltophilia isolates. In vitro susceptibility testing using tetracycline HCL as a surrogate for the susceptibility other tetracyclines fails to detect minocycline-susceptible isolates and the potential utility of minocycline for the treatment of many MDR A. baumannii infections and other difficult-to-treat species, where there are often limited choices of antimicrobials. PMID:25371512

  11. Sensitive, resistant and multi-drug resistant Acinetobacter baumanii at Saudi Arabia hospital eastern region.

    PubMed

    Ahmed, Mughis Uddin; Farooq, Reshma; Al-Hawashim, Nadia; Ahmed, Motasim; Yiannakou, Nearchos; Sayeed, Fatima; Sayed, Ali Rifat; Lutfullah, Sualiha

    2015-05-01

    Since the Physicians start use of antibiotics long ago with un-notice drug resistance. However actual problem was recognized about 85 years ago. Antibiotic resistant and Multi-drug resistant bacterial strains are at rise throughout the world. It is physicians and researchers to take scientific research based appropriate action to overcome this ever-spreading problem. This study is designed to find out sensitive (S), resistant (R) and multi-drug resistant (MDR) Acinetobacter baumanii strain along with other isolates in the resident patients of Eastern Region of Saudi Arabia. Pseudomonas aeruginosa is excluded from other gram-negative organisms isolated from different sites as it will be dealt separately. This study is based in was retrospective observations designed to collect data of different stains of Acinetobacter baumanii with reference to their Sensitivity (S), Resistance (R), Multi-Drug Resistance (MDR) along with other Gram negative isolated from different sites (from 1st January 2004 to 31st December 2011) at King Abdulaziz Hospital located Eastern Region of Kingdom of Saudi Arabia (KSA). All necessary techniques were used to culture and perform sensitivity of these isolates. There were 4532 isolates out of which 3018 (67%) were from patients. Out of Acinetobacter baumanii infected were 906 (20%) while other 3626 (80%) isolates were miscellaneous. Numbers of patients or cases were 480 (53%) out of 906 isolates and numbers of patients or cases in other organisms were 2538 (70%) out of 3626 isolates. Acinetobacter baumanii infected patients 221 (46%) were male and 259 (54%) were female and the male and female ratio of 1:1.2. In other organisms this male female ratio was almost same. There was steady rise in number of patients and the hence the isolates from 2004 to 2011. Majority of the bacterial strains were isolated as single organism but some were isolated as double or triple or quadruple or more organisms from different sites. Sensitive, Resistant and Multi-Drug Resistant Acinetobacter baumanii have been isolated from different sites. The other Gram negative isolates included Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Klebsiella oxytoca, Serratia marcescens and Stenotrophomonas maltophilia. A significant rise in R and MDR but there is rise in R and MDR Acinetobacter baumanii Strains has been interceded other isolates. It is important to adopt proper and sustainable policies and guideline regarding antibiotics prescription and used. We should also check our infection control practices in our hospital or healthcare settings. We should start antibiotics stewardship in our hospital in order to reducing or overcoming antibiotics Resistant (R) and Multi-Drug Resistant (MDR) strains prevalence. PMID:26004714

  12. Phenotypic and Genetic Characterization of Carbapenemase and ESBLs Producing Gram-negative Bacteria (GNB) Isolated from Patients with Cystic Fibrosis (CF) in Tehran Hospitals

    PubMed Central

    Vali, Parisa; Shahcheraghi, Fereshteh; Seyfipour, Maryam; Zamani, Maryam Alsadat; Allahyar, Mohammad Reza; Feizabadi, Mohammad Mehdi

    2014-01-01

    Background: Cystic Fibrosis (CF) is an autosomal recessive genetic disorder in white populations caused by mutation in a gene that encodes Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein. Since frequent respiratory tract infections are the major problem in patients with CF, obligation to identify the causative bacteria and determining their antibiotic resistance pattern is crucial. The purpose of this project was to detect Gram-negative bacteria (GNB) isolated from sputa of CF patients and to determine their antibiotic resistance pattern. Materials and Methods: The sputum of 52 CF patients, treated as inpatients at hospitals in Tehran, was obtained between November 2011 and June 2012. Samples cultured in selective and non-selective media and GNB recognized by biochemical tests. Antimicrobial susceptibility testing to cephalosporins, aminoglycosides and carbapenems was performed by disk diffusion method and MICs of them were measured. For phenotypic detection of carbapenemase and ESBLs production, the Modified Hodge test, double disk synergy test and the combined disk methods were performed. Subsequently, the genes encoding the extended spectrum beta-lactamases (blaPER, blaCTX-M) and carbapenemases (blaIMP-1, blaGES, blaKPC, blaNDM, blaVIM-1, blaVIM-2, blaSPM, blaSIM) in Gram negative bacteria were targeted among the resistant isolates by using PCR. PFGE was used to determine any genetic relationship among the Pseudomonas aeruginosa isolated from these patients. Results: Fifty five GNB were isolated from 52 sputum samples including Pseudomonas aeruginosa, Klebsiella ozaenae, Alcaligenes xylosoxidans, Achromobacter denitrificans, Klebsiella pneumonia and Stenotrophomonas maltophilia. The rates of resistance to different antibiotic were as follows: cefixime (%80), ceftriaxone (%43), ceftazidime (%45) and meropenem (%7). The prevalence of genes encoding the ESBLs and Carbapenemases among the the phenotypically positive strains were as follows: blaCTX-M (19), blaIMP-1 (2), blaVIM-1 (2) and blaVIM-2 (3) genes respectively. No other genes were detected. PFGE analysis revealed 8 genotypes. Six isolates had mutually 3 similar patterns. Conclusion: This study showed the existence of important ESBLs and carbapenemases genes among the GNB isolated from patients with CF. Continuous surveillance of ESBLs and Carbapenemases, also identification of their types, in bacteria isolated from these patients have an important clinical impact, since, it can often provide valuable information for effective infection control measures and for the choice of appropriate antimicrobial therapy. PMID:24596716

  13. Multidrug-resistant Gram-negative infections: what are the treatment options?

    PubMed

    Giamarellou, Helen; Poulakou, Garyphallia

    2009-10-01

    The emergence of multidrug-resistant (MDR) Gram-negative bacilli creates a challenge in the treatment of nosocomial infections. While the pharmaceutical pipeline is waning, two revived old antibacterials (colistin and fosfomycin), a newer one (tigecycline) and an 'improved' member of an existing class (doripenem) are the only therapeutic options left. The class of polymyxins, known since 1947 and represented mostly by polymyxin B and polymyxin E (colistin), has recently gained a principal role in the treatment of the most problematic MDR Gram-negative pathogens (such as Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae and Stenotrophomonas maltophilia). Future prospective studies are needed to answer important clinical questions, such as the possible benefit of combination with other antimicrobials versus monotherapy, the efficacy of colistin in neutropenic hosts and the role of inhaled colistin. As new pharmacokinetic data emerge, clarification of the pharmacokinetic/pharmacodynamic (PK/PD) profile of colistin as well as appropriate dosing seems urgent, while development of resistance must be carefully monitored. Fosfomycin tromethamine, a synthetic salt of fosfomycin discovered in 1969, has regained attention because of its in vitro activity against extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae and MDR P. aeruginosa. Although in use for decades in oral and parenteral formulations for a variety of infections without significant toxicity, its clinical utility in MDR infections remains to be explored in future studies. Tigecycline, the first representative of the new class of glycylcyclines, holds promise in infections from MDR K. pneumoniae (K. pneumoniae carbapenemase [KPC]- and ESBL-producing strains) and Enterobacteriaceae with various mechanisms of resistance. The in vitro activity of tigecycline against A. baumannii makes it a tempting option, as it is currently the most active compound against MDR strains along with colistin. However, the usual minimum inhibitory concentration values of this pathogen are approximately 2 mg/L and compromise clinical outcomes based on PK/PD issues. Its advantageous penetration into various tissues is useful in infections of the skin and soft tissues as well as intra-abdominal infections (official indications), whereas low serum concentrations compromise its use in bloodstream infections. Therefore, prospective studies with dose escalation are urgently needed, as well as clarification of its role in nosocomial pneumonia, after poor results in the study of ventilator-associated pneumonia. Finally, doripenem, the recently licensed member of the carbapenems (without significant spectrum alterations from the ascendant members) seems to possess a lower potential for resistance selection and a more favourable pharmacokinetic profile when given as an extended infusion. The latter strategy could prove helpful in overcoming low level resistance of A. baumannii and P. aeruginosa strains. PMID:19747006

  14. Application of a constructed wetland system for polluted stream remediation

    NASA Astrophysics Data System (ADS)

    Tu, Y. T.; Chiang, P. C.; Yang, J.; Chen, S. H.; Kao, C. M.

    2014-03-01

    In 2010, the multi-function Kaoping River Rail Bridge Constructed Wetland (KRRBW) was constructed to improve the stream water quality and rehabilitate the ecosystem of the surrounding environment of Dashu Region, Kaohsiung, Taiwan. The KRRBW consists of five wetland basins with a total water surface area of 15 ha, a total hydraulic retention time (HRT) of 10.1 days at a averaged flow rate of 14 740 m3/day, and an averaged water depth of 1.1 m. The influent of KRRBW coming from the local drainage systems containing untreated domestic, agricultural, and industrial wastewaters. Based on the quarterly investigation results of water samples taken in 2011-2012, the overall removal efficiencies were 91% for biochemical oxygen demand (BOD), 75% for total nitrogen (TN), 96% for total phosphorus (TP), and 99% for total coliforms (TC). The calculated first-order decay rates for BOD, TN, TP, NH3-N, and TC ranged from 0.14 (TN) to 0.42 (TC) 1/day. This indicates that the KRRBW was able to remove organics, TC, and nutrients effectively. The high ammonia/nitrate removal efficiency indicates that nitrification and denitrification processes occurred simultaneously in the wetland system, and the detected nitrite concentration confirmed the occurrence of denitrification/nitrification. Results from sediment analyses reveal that the sediment contained high concentrations of organics (sediment oxygen demand = 1.9-5.2 g O2/m2 day), nutrients (up to 15.8 g total nitrogen/kg of sediment and 1.48 g total phosphorus/kg of sediment), and metals (up to 547 mg/kg of Zn and 97 mg/kg of Cu). Appropriate wetland management strategies need to be developed to prevent the release of contaminants into the wetland system. The wetland system caused the variations in the microbial diversities and dominant microbial bacteria. Results show the dominant nitrogen utilization bacteria including Denitratisoma oestradiolicum, Nitrosospira sp., Nitrosovibrio sp., D. oestradiolicum, Alcaligenes sp., Steroidobacter denitrificans, Hydrocarboniphaga effuse were responsible for nitrogen removal, and the dominant carbon degrading bacteria (Stenotrophomonas maltophilia, H. effuse, Alcaligenes sp., Pseudomonas sp., Fusibacter sp., Chlofoflexi, Guggenheimella bovis, Bacillus pumilus) were responsible for carbon reduction. The denaturing gradient gel electrophoresis (DGGE) and nucleotide sequence techniques provide a guide for microbial ecology evaluation, which can be used as an indication of contaminants removal. Results from this study show that constructed wetlands have the potential to be developed into an environmentally acceptable river water quality improvement and wastewater polishment alternative for practical application.

  15. Ceftobiprole Activity against over 60,000 Clinical Bacterial Pathogens Isolated in Europe, Turkey, and Israel from 2005 to 2010

    PubMed Central

    Flamm, Robert K.; Sader, Helio S.; Jones, Ronald N.

    2014-01-01

    Ceftobiprole medocaril is a newly approved drug in Europe for the treatment of hospital-acquired pneumonia (HAP) (excluding patients with ventilator-associated pneumonia but including ventilated HAP patients) and community-acquired pneumonia in adults. The aim of this study was to evaluate the in vitro antimicrobial activity of ceftobiprole against prevalent Gram-positive and -negative pathogens isolated in Europe, Turkey, and Israel during 2005 through 2010. A total of 60,084 consecutive, nonduplicate isolates from a wide variety of infections were collected from 33 medical centers. Species identification was confirmed, and all isolates were susceptibility tested using reference broth microdilution methods. Ceftobiprole had high activity against methicillin-susceptible Staphylococcus aureus (MSSA) (100.0% susceptible), methicillin-susceptible coagulase-negative staphylococci (CoNS), beta-hemolytic streptococci, and Streptococcus pneumoniae (99.3% susceptible), with MIC90 values of 0.25, 0.12, ≤0.06, and 0.5 μg/ml, respectively. Ceftobiprole was active against methicillin-resistant S. aureus (MRSA) (98.3% susceptible) and methicillin-resistant CoNS, having a MIC90 of 2 μg/ml. Ceftobiprole was active against Enterococcus faecalis (MIC50/90, 0.5/4 μg/ml) but not against most Enterococcus faecium isolates. Ceftobiprole was very potent against the majority of Enterobacteriaceae (87.3% susceptible), with >80% inhibited at ≤0.12 μg/ml. The potency of ceftobiprole against Pseudomonas aeruginosa (MIC50/90, 2/>8 μg/ml; 64.6% at MIC values of ≤4 μg/ml) was similar to that of ceftazidime (MIC50/90, 2/>16 μg/ml; 75.4% susceptible), but limited activity was observed against Acinetobacter spp. and Stenotrophomonas maltophilia. High activity was also observed against all Haemophilus influenzae (MIC90, ≤0.06 μg/ml) and Moraxella catarrhalis (MIC50/90, ≤0.06/0.25 μg/ml) isolates. Ceftobiprole demonstrated a wide spectrum of antimicrobial activity against this very large longitudinal sample of contemporary pathogens. PMID:24777091

  16. Nile Red Detection of Bacterial Hydrocarbons and Ketones in a High-Throughput Format

    SciTech Connect

    Pinzon, NM; Aukema, KG; Gralnick, JA; Wackett, LP

    2011-06-28

    A method for use in high-throughput screening of bacteria for the production of long-chain hydrocarbons and ketones by monitoring fluorescent light emission in the presence of Nile red is described. Nile red has previously been used to screen for polyhydroxybutyrate (PHB) and fatty acid esters, but this is the first report of screening for recombinant bacteria making hydrocarbons or ketones. The microtiter plate assay was evaluated using wild-type and recombinant strains of Shewanella oneidensis and Escherichia coli expressing the enzyme OleA, previously shown to initiate hydrocarbon biosynthesis. The strains expressing exogenous Stenotrophomonas maltophilia oleA, with increased levels of ketone production as determined by gas chromatography-mass spectrometry, were distinguished with Nile red fluorescence. Confocal microscopy images of S. oneidensis oleA-expressing strains stained with Nile red were consistent with a membrane localization of the ketones. This differed from Nile red staining of bacterial PHB or algal lipid droplets that showed intracellular inclusion bodies. These results demonstrated the applicability of Nile red in a high-throughput technique for the detection of bacterial hydrocarbons and ketones. IMPORTANCE In recent years, there has been renewed interest in advanced biofuel sources such as bacterial hydrocarbon production. Previous studies used solvent extraction of bacterial cultures followed by gas chromatography-mass spectrometry (GC-MS) to detect and quantify ketones and hydrocarbons (Beller HR, Goh EB, Keasling JD, Appl. Environ. Microbiol. 76: 1212-1223, 2010; Sukovich DJ, Seffernick JL, Richman JE, Gralnick JA, Wackett LP, Appl. Environ. Microbiol. 76: 3850-3862, 2010). While these analyses are powerful and accurate, their labor-intensive nature makes them intractable to high-throughput screening; therefore, methods for rapid identification of bacterial strains that are overproducing hydrocarbons are needed. The use of high-throughput evaluation of bacterial and algal hydrophobic molecule production via Nile red fluorescence from lipids and esters was extended in this study to include hydrocarbons and ketones. This work demonstrated accurate, high-throughput detection of high-level bacterial long-chain ketone and hydrocarbon production by screening for increased fluorescence of the hydrophobic dye Nile red.

  17. Multispecies Biofilm Development on Space Station Heat Exhanger Core Material

    NASA Technical Reports Server (NTRS)

    Pyle, B. H.; Roth, S. R.; Vega, L. M.; Pickering, K. D.; Alvarez, Pedro J. J.; Roman, M. C.

    2007-01-01

    Investigations of microbial contamination of the cooling system aboard the International Space Station (ISS) suggested that there may be a relationship between heat exchanger (HX) materials and the degree of microbial colonization and biofilm formation. Experiments were undertaken to test the hypothesis that biofilm formation is influenced by the type and previous exposure of HX surfaces. Acidovorax delafieldii, Comamonas acidovorans, Hydrogenophaga pseudoflava, Pseudomonas stutzeri, Sphingomonas paucimobilis, and Stenotrophomonas maltophilia, originally isolated from ISS cooling system fluid, were cultured on R2A agar and suspended separately in fresh filter-sterilized ISS cooling fluid, pH 8.3. Initial numbers in each suspension ranged from 10(exp 6)-10(exp 7) CFU/ml, and a mixture contained greater than 10(exp 7) CFU/ml. Coupons of ISS HX material, previously used on orbit (HXOO) or unused (HXUU), polycarbonate (PC) and 316L polished stainless steel (SS) were autoclaved, covered with multispecies suspension in sterile tubes and incubated in the dark at ambient (22-25 C). Original HX material contained greater than 90% Ni, 4.5% Si, and 3.2% B, with a borate buffer. For approximately 10 weeks, samples of fluid were plated on R2A agar, and surface colonization assessed by SYBR green or BacLight staining and microscopy. Suspension counts for the PC and SC samples remained steady at around 10(exp 7) CFU/ml. HXUU counts declined about 1 log in 21 d then remained steady, and HXOO counts declined 2 logs in 28 d, fluctuated and stabilized about 10(exp 3) CFU/ml from 47-54 d. Predominantly yellow S. paucimobilis predominated on plates from HXOO samples up to 26 d, then white or translucent colonies of other species appeared. All colony types were seen on plates from other samples throughout the trial. Epifluorescence microscopy indicated microbial growth on all surfaces by 21 d, followed by variable colonization. After 54 d, all but the HXOO samples had well-distributed live and dead cells; the HXOO samples had few cells and most were live by BacLight. The results suggest that HX materials themselves are inhibiting microbial growth on the surfaces. The HX exposed on orbit to cooling system fluid inhibited growth of some species originally isolated from the system, whereas the unused HX material had a moderate effect compared to no inhibition with PC or SS controls. It is possible that chemistry or microbiology of the ISS system increased deposition of inhibitory compounds on the HXOO coupon surfaces; these may inhibit inoculated species to differing degrees.

  18. MIXED-SPECIES COLONIZATION OF SOLID SURFACES IN LABORATORY BIOFILMS

    EPA Science Inventory

    Colonization of glass substrata by populations of three or four bacterial species over periods of four weeks or more was investigated using recirculating, model laboratory systems. umbers of coryneform, Aeromonas hydrophile, Pseudomonas fluoresces, and Xanthomonas maltophilia on ...

  19. Draft Genome Sequence of Serratia marcescens Strain LCT-SM213

    PubMed Central

    Wang, Yajuan; Yuan, Yanting; Zhou, Lisha; Su, Qingqing; Fang, Xiangqun; Li, Tianzhi; Wang, Junfeng; Chang, De; Su, Longxiang; Xu, Guogang; Guo, Yinghua

    2012-01-01

    Serratia marcescens is a species of Gram-negative, rod-shaped bacterium of the family Enterobacteriaceae. S. marcescens can cause nosocomial infections, particularly catheter-associated bacteremia, urinary tract infections, and wound infections. Here, we present the draft genome sequence of Serratia marcescens strain LCT-SM213, which was isolated from CGMCC 1.1857. PMID:22843602

  20. Complete genome sequence of the metabolically versatile halophilic archaeon Haloferax mediterranei, a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) producer.

    PubMed

    Han, Jing; Zhang, Fan; Hou, Jing; Liu, Xiaoqing; Li, Ming; Liu, Hailong; Cai, Lei; Zhang, Bing; Chen, Yaping; Zhou, Jian; Hu, Songnian; Xiang, Hua

    2012-08-01

    Haloferax mediterranei, an extremely halophilic archaeon, has shown promise for production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from unrelated cheap carbon sources. Here we report the complete genome (3,904,707 bp) of H. mediterranei CGMCC 1.2087, consisting of one chromosome and three megaplasmids. PMID:22843593

  1. Complete Genome Sequence of the Extremely Halophilic Archaeon Haloarcula hispanica Strain N601

    PubMed Central

    Ding, Jiun-Yan; Chiang, Pei-Wen; Hong, Mei-Jhu; Dyall-Smith, Mike

    2014-01-01

    Haloarcula hispanica has been widely used in haloarchaeal studies, particularly in the isolation of haloviruses. The genome of strain N601, a laboratory derivative of the type strain ATCC 33960, was sequenced. Several potentially significant differences from the published sequence of the type strain (CGMCC 1.2049 = ATCC 33960) were observed. PMID:24625874

  2. Phylogenomic analysis shows that ‘Bacillus vanillea’ is a later heterotypic synonym of Bacillus siamensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Bacillus vanillea’ XY18T (=CGMCC 8629 T =NCCB 100507 T) was isolated from cured vanilla beans and involved in the formation of vanilla aroma compounds. A draft genome of this type strain was assembled and yielded a length of 3.72 Mbp and a GC content of 46.3%. Comparative genomic analysis with its ...

  3. Amycolatopsis flava sp. nov., a halophilic actinomycete isolated from Dead Sea.

    PubMed

    Wei, Xiaomin; Jiang, Yingying; Chen, Xiu; Jiang, Yi; Lai, Hangxian

    2015-10-01

    A novel halophilic, filamentous actinomycete, designated strain AFM 10111(T), was isolated from a sediment sample collected from the Dead Sea of Israel and its taxonomic position was established by using a polyphasic taxonomic approach. The isolate grew at 20-35 C, pH 5-12 and with 1-30 % NaCl. The substrate mycelium is white or yellow, well developed, branched and fragments into squarish, rod-like elements. The isolate contained meso-diaminopimelic acid as cell-wall diamino acid, and arabinose and galactose as whole-cell sugars. The major menaquinone was MK-9(H4). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine phosphatidylmethylethanolamine and one unidentified phospholipid. Major fatty acids were iso-C16:0, iso-C16:1 H, C17:1 ?6c. The DNA G + C content was 67.7 mol %. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AFM 10111(T) belongs to the genus Amycolatopsis, and formed a distinct clade with Amycolatopsis marina CGMCC 4.3568(T) and Amycolatopsis palatopharyngis CGMCC 4.1729(T), with the sequence similarity 98.4 and 98.6 %. The level of DNA-DNA relatedness between the strain AFM 10111(T) and A. marina CGMCC 4.3568(T) and A. palatopharyngis CGMCC 4.1729(T) were 46.9 3.08 and 49.4 1.25 %. The combined genotypic and phenotypic data indicate that strain AFM 10111(T) represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsis flava sp. nov. is proposed. The type strain is AFM 10111(T) (= DSM 46658(T) = CGMCC 4.7123(T)). PMID:26233655

  4. Evaluation of immunomodulatory activity of two potential probiotic Lactobacillus strains by in vivo tests.

    PubMed

    Ren, Dayong; Li, Chang; Qin, Yanqing; Yin, Ronglan; Du, Shouwen; Liu, Hongfeng; Zhang, Yanfang; Wang, Cuiyan; Rong, Fengjun; Jin, Ningyi

    2015-10-01

    Here we evaluate the immunomodulatory function of two potential probiotic strains, Lactobacillus salivarius CICC 23174 and Lactobacillus plantarum CGMCC 1.557. Mice were fed with each Lactobacillus strain at different doses for several consecutive days. The effects of the two probiotic strains on immune organs, immune cells and immune molecules were investigated on days 10 and 20. Both Lactobacillus strains increased the spleen index, improved the spleen lymphocyte transformation rate, enhanced sIgA production and improved the number of CD11c(+) CD80(+) double-positive cells. L. plantarum CGMCC 1.557 was the more active strain in enhancing the phagocytic activity of macrophages, while, L. salivarius CICC 23174 was the more effective strain at maintaining the Th1/Th2 balance. This study suggests that these two Lactobacillus strains have beneficial effects on regulation of immune responses, which has promising implications for the development of ecological agents and functional foods. PMID:26143437

  5. Microbial transformation of diosgenin by filamentous fungus Cunninghamella echinulata.

    PubMed

    Xiao, Xiao; Liu, Xi-Kui; Fu, Shao-Bin; Sun, Di-An

    2011-03-01

    Microbial transformation of diosgenin (1) by suspended-cell cultures of the filamentous fungus Cunninghamella echinulata CGMCC 3.2000 was investigated. Incubation of the substrate diosgenin (1) with this fungus led to the isolation of three products: two known compounds, (25R)-spirost-5-en-3?,7?,12?-triol and (25R)-spirost-5-en-3?,7?,11?-triol, and a new compound (25R)-spirost-5-en-3?,7?,11?-triol. The structural elucidations of the three compounds were achieved mainly by the MS, 1D and 2D NMR spectroscopic methods and comparison with known compounds. C. echinulata CGMCC 3.2000 has not been used before in the biotransformation of diosgenin. PMID:21409691

  6. Characterization of Inulin Hydrolyzing Enzyme(s) in Oleaginous Yeast Trichosporon cutaneum in Consolidated Bioprocessing of Microbial Lipid Fermentation.

    PubMed

    Wang, Juan; Zhang, Huizhan; Bao, Jie

    2015-11-01

    Oleaginous yeast Trichosporon cutaneum CGMCC 2.1374 was found to utilize inulin directly for microbial lipid fermentation without a hydrolysis step. The potential inulinase-like enzyme(s) in T. cutaneum CGMCC 2.1374 were characterized and compared with other inulinase enzymes produced by varied yeast strains. The consolidated bioprocessing (CBP) for lipid accumulated using inulin was optimized with 4.79 g/L of lipid produced from 50 g/L inulin with the lipid content of 33.6% in dry cells. The molecular weight of the enzyme was measured which was close to invertase in Saccharomyces cerevisiae. The study provided information for inulin hydrolyzing enzyme(s) in oleaginous yeasts, as well as a preliminary CBP process for lipid production from inulin feedstock. PMID:26306527

  7. Comparison of aroma-active volatiles and their sensory characteristics of mangosteen wines prepared by Saccharomyces cerevisiae with GC-olfactometry and principal component analysis.

    PubMed

    Xiao, Zuo Bing; Liu, Jun Hua; Chen, Feng; Wang, Ling Ying; Niu, Yun Wei; Feng, Tao; Zhu, Jian Cai

    2015-01-01

    Mangosteen fruit is fermented with five different strains (i.e. GRE (Y1), Lalvin RC212 (Y2), Lalvin D254 (Y3), CGMCC2.23 (Y4) and CGMCC2.4 (Y5)) of the yeast Saccharomyces cerevisiae to make mangosteen wines. A total of 36 volatile compounds of the mangosteen wines were identified by gas chromatography-mass spectrometry and gas chromatography-pulsed flame photometric detection. A total of 35 odour-active compounds were identified by gas chromatography-olfactometry analysis and by the detection frequency (DF) method. The compounds with high DF values included ethyl octanoate, ethyl hexanoate and 3-methyl-2-butene-1-thiol. Principal component analysis was used to characterise the differences of the flavour profiles of those mangosteen wines. The result demonstrated that the samples could be divided into three groups that were associated closely with aroma-active compounds. PMID:25428208

  8. Complete genome sequence of Bifidobacterium adolesentis BBMN23, a probiotic strain from healthy centenarian.

    PubMed

    Liu, Songling; Zhao, Liang; Ren, Fazheng; Sun, Erna; Zhang, Ming; Guo, Huiyuan

    2015-03-20

    Bifidobacterium adolesentis BBMN23 (CGMCC No. 2264) was a probiotic strain originated from the feces of a centenarian. It is an excellent model for the study of the adaptation of genus bifidobacteria to adult human gut, which is a key factor in bifidobacterial strains that allows them to persist in gut and become useful in the food and medical industries. In the present study the complete genome sequence of BBMN23 is presented to provide insight into this strain. PMID:25678139

  9. Microbial Transformation of 14-Anhydrodigoxigenin by Alternaria alternata.

    PubMed

    Liu, Jimei; Tang, Wanxia; Chen, Ridao; Dai, Jungui

    2015-12-01

    The microbial transformation of 14-anhydrodigoxigenin (1) by Alternaria alternata CGMCC 3.577 led to the production of seven new metabolites, 2-8. Their structures were determined by extensive spectroscopic (CD, IR, 1D- and 2D-NMR, and HR-ESI-MS) data analyses. The reactions in the bioprocess exhibited diversity, including specific oxidation, hydroxylation, reduction, epoxidation, and dehydration. In addition, a hypothetical biocatalytic pathway is proposed. PMID:26663840

  10. Halomonas saccharevitans sp. nov., Halomonas arcis sp. nov. and Halomonas subterranea sp. nov., halophilic bacteria isolated from hypersaline environments of China.

    PubMed

    Xu, Xue-Wei; Wu, Yue-Hong; Zhou, Zhen; Wang, Chun-Sheng; Zhou, Yu-Guang; Zhang, Hui-Bin; Wang, Yong; Wu, Min

    2007-07-01

    Three strains of Gram-negative, aerobic, neutrophilic and halophilic bacteria were isolated from samples of a salt lake on the Qinghai-Tibet Plateau and a subterranean saline well in the Si-Chuan Basin of China. These isolates, designated AJ275(T), AJ282(T) and ZG16(T), were investigated using a polyphasic approach. Based on 16S rRNA gene sequence analysis, the isolates could be affiliated to the genus Halomonas. Genomic DNA G+C contents were 65.9 mol% for AJ275(T), 56.7 mol% for AJ282(T) and 57.6 mol% for ZG16(T). The results of DNA-DNA hybridizations, fatty acid analysis and physiological and biochemical tests allowed the isolates to be differentiated genotypically and phenotypically from closely related species. It is proposed that strains AJ275(T) (=CGMCC 1.6493(T)=JCM 14606(T)=LMG 23976(T)), AJ282(T) (=CGMCC 1.6494(T)=JCM 14607(T)=LMG 23978(T)) and ZG16(T) (=CGMCC 1.6495(T)=JCM 14608(T)=LMG 23977(T)) represent the type strains of three novel species in the genus Halomonas: Halomonas saccharevitans sp. nov., Halomonas arcis sp. nov. and Halomonas subterranea sp. nov., respectively. PMID:17625205

  11. Characterization of Pseudomonas species isolated from clinical specimens.

    PubMed

    Gilardi, G L

    1971-03-01

    More than 90 morphological and physiological characters of 227 strains of pseudomonads isolated from clinical specimens and 16 reference strains are described. The clinical isolates included P. aeruginosa (apyocyanogenic), P. fluorescens, P. putida, P. pseudomallei, P. cepacia, P. acidovorans, P. alcaligenes, P. pseudoalcaligenes, P. stutzeri, P. putrefaciens, P. maltophilia, and P. diminuta. PMID:4928600

  12. INFLUENCE OF SOLID SURFACE, ADHESIVE ABILITY, AND INOCULUM SIZE ON BACTERIAL COLONIZATION IN MICROCOSM STUDIES

    EPA Science Inventory

    Microcosm studies were performed to evaluate the effect of solid surfaces, bacterial adhesive ability, and inoculum size on colonization success and persistence of P. fluorescens or X maltophilia, each with a Tn5 insertion that conferred resistance to kanamycin and streptomycin. ...

  13. Characterization of Pseudomonas Species Isolated from Clinical Specimens 1

    PubMed Central

    Gilardi, G. L.

    1971-01-01

    More than 90 morphological and physiological characters of 227 strains of pseudomonads isolated from clinical specimens and 16 reference strains are described. The clinical isolates included P. aeruginosa (apyocyanogenic), P. fluorescens, P. putida, P. pseudomallei, P. cepacia, P. acidovorans, P. alcaligenes, P. pseudoalcaligenes, P. stutzeri, P. putrefaciens, P. maltophilia, and P. diminuta. PMID:4928600

  14. Marinobacter shengliensis sp. nov., a moderately halophilic bacterium isolated from oil-contaminated saline soil.

    PubMed

    Luo, Yi-Jing; Xie, Bai-Sheng; Lv, Xiang-Lin; Cai, Man; Wang, Ya-Nan; Cui, Heng-Lin; Cai, Hua; Wu, Xiao-Lei

    2015-04-01

    Two moderately halophilic strains, designated SL013A34A2(T) and SL013A24A, were isolated from oil-contaminated saline soil from Shengli Oilfield, eastern China. Cells were found to be Gram-staining negative, aerobic, rod-shaped with a single polar flagellum. The isolates were found to grow at 10-40 °C (optimum 35 °C), pH 6.0-9.0 (optimum pH 8.0), and NaCl concentrations of 0.5-18.0 % (w/v) (optimum 3.0-6.0 NaCl). The 16S rRNA gene sequence analysis indicated that the isolates belong to the genus Marinobacter. Strain SL013A34A2(T) shares the highest 16S rRNA gene sequence similarities with strain SL013A24A (99.3 %), followed by M. hydrocarbonoclasticus CGMCC 1.7683(T) (97.8 %), M. vinifirmus CGMCC 1.7265(T) (97.8 %), and M. excellens KMM 3809(T) (97.4 %), respectively, but low similarities (93.8-96.4 %) with type strains of the other numbers of genus Marinobacter. DNA-DNA relatedness values of strain SL013A34A2(T) with strains SL013A24A, M. hydrocarbonoclasticus CGMCC 1.7683(T), M. vinifirmus CGMCC 1.7265(T) and M. excellens KMM 3809(T) were 88.7, 29.2, 33.4 and 29.4 %, respectively. The major fatty acids of strain SL013A34A2(T) were identified as C18:1 ω9c, C16:0, C12:03-OH, C12:0, C16:1 ω9c and 10-methyl C18:0. The major respiratory quinone of strain SL013A34A2(T) was found to be ubiquinone-9, and its predominant polar lipids were identified as diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and unidentified glycolipid. The genomic DNA G + C content was found to be 56.1 mol %. Based on the phenotypic, genetic and chemotaxonomic characteristics, these two isolates are representatives of a novel species of the genus Marinobacter, for which the name Marinobacter shengliensis sp. nov. is proposed. The type strain is SL013A34A2(T)(=LMG 27740(T) = CGMCC 1.12758(T)). PMID:25652339

  15. Analyzing the antagonistic potential of the lichen microbiome against pathogens by bridging metagenomic with culture studies

    PubMed Central

    Cernava, Tomislav; Müller, Henry; Aschenbrenner, Ines A.; Grube, Martin; Berg, Gabriele

    2015-01-01

    Naturally occurring antagonists toward pathogens play an important role to avoid pathogen outbreaks in ecosystems, and they can be applied as biocontrol agents for crops. Lichens present long-living symbiotic systems continuously exposed to pathogens. To analyze the antagonistic potential in lichens, we studied the bacterial community active against model bacteria and fungi by an integrative approach combining isolate screening, omics techniques, and high resolution mass spectrometry. The highly diverse microbiome of the lung lichen [Lobaria pulmonaria (L.) Hoffm.] included an abundant antagonistic community dominated by Stenotrophomonas, Pseudomonas, and Burkholderia. While antagonists represent 24.5% of the isolates, they were identified with only 7% in the metagenome; which means that they were overrepresented in the culturable fraction. Isolates of the dominant antagonistic genus Stenotrophomonas produced spermidine as main bioactive component. Moreover, spermidine-related genes, especially for the transport, were identified in the metagenome. The majority of hits identified belonged to Alphaproteobacteria, while Stenotrophomonas-specific spermidine synthases were not present in the dataset. Evidence for plant growth promoting effects was found for lichen-associated strains of Stenotrophomonas. Linking of metagenomic and culture data was possible but showed partly contradictory results, which required a comparative assessment. However, we have shown that lichens are important reservoirs for antagonistic bacteria, which open broad possibilities for biotechnological applications. PMID:26157431

  16. Genetic and biochemical characterization of the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) synthase in Haloferax mediterranei.

    PubMed

    Lu, Qiuhe; Han, Jing; Zhou, Ligang; Zhou, Jian; Xiang, Hua

    2008-06-01

    The haloarchaeon Haloferax mediterranei has shown promise for the economical production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a desirable bioplastic. However, little is known at present about the genes involved in PHBV synthesis in the domain Archaea. In this study, we cloned the gene cluster (phaEC(Hme)) encoding a polyhydroxyalkanoate (PHA) synthase in H. mediterranei CGMCC 1.2087 via thermal asymmetric interlaced PCR. Western blotting revealed that the phaE(Hme) and phaC(Hme) genes were constitutively expressed, and both the PhaE(Hme) and PhaC(Hme) proteins were strongly bound to the PHBV granules. Interestingly, CGMCC 1.2087 could synthesize PHBV in either nutrient-limited medium (supplemented with 1% starch) or nutrient-rich medium, up to 24 or 18% (wt/wt) in shaking flasks. Knockout of the phaEC(Hme) genes in CGMCC 1.2087 led to a complete loss of PHBV synthesis, and only complementation with the phaEC(Hme) genes together (but not either one alone) could restore to this mutant the capability for PHBV accumulation. The known haloarchaeal PhaC subunits are much longer at their C termini than their bacterial counterparts, and the C-terminal extension of PhaC(Hme) was proven to be indispensable for its function in vivo. Moreover, the mixture of purified PhaE(Hme)/PhaC(Hme) (1:1) showed significant activity of PHA synthase in vitro. Taken together, our results indicated that a novel member of the class III PHA synthases, composed of PhaC(Hme) and PhaE(Hme), accounted for the PHBV synthesis in H. mediterranei. PMID:18408025

  17. Hamadaea flava sp. nov., isolated from a soil sample and emended description of the genus Hamadaea.

    PubMed

    Chu, Xiao; Li, Shuai; Chen, Wei; Devi Asem, Mipeshwaree; Duan, Yan-Qing; Nie, Guo-Xing; Hozzein, Wael N; Zhi, Xiao-Yang; Li, Wen-Jun

    2016-04-01

    A Gram-stain-positive, aerobic and non-motile actinobacterial strain, designated YIM C0533T, was isolated from a soil sample collected from Shiling county, Yunnan province, south-west China. The isolate grew at 15-37 °C, pH 6.0-8.0 and in the presence of 0-3 % (w/v) NaCl. The whole-cell hydrolysates contained meso-diaminopimelic acid, xylose, galactose, mannose, ribose, arabinose, glucose and rhamnose. The acyl type of muramic acid was glycolyl. The polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified phospholipid. The major cellular fatty acids were iso-C16 : 0, 10-methyl C17 : 0 and iso-C15 : 0.MK-9(H6) was the predominant menaquinone. The genomic DNA G+C content was determined to be 69.4 mol%. These chemotaxonomic data and the morphological properties were consistent with those of the genus Hamadaea. The strain showed highest sequence similarities to Hamadaea tsunoensis CGMCC 4.1403T on phylogenetic analysis of 16S rRNA gene sequences and was found to form a coherent cluster in the neighbour-joining tree. The DNA-DNA hybridization experiment indicated that the DNA-DNA relatedness value between strain YIM C0533T and H. tsunoensis CGMCC 4.1403T was 34.4 ± 1.3 %. In addition, the results of physiological and biochemical tests allowed the isolate to be differentiated phenotypically from H. tsunoensis CGMCC 4.1403T. On the basis of data from this polyphasic study, strain YIM C0533T is characterized as a novel species of the genus Hamadaea, for which the name Hamadaea flava sp. nov. is proposed. The type strain is YIM C0533T ( = CPCC 204160T = KCTC 39591T = CGMCC 4.7289T). An emended description of the genus Hamadaea is also provided. PMID:26842996

  18. Complete genome sequence of endophytic nitrogen-fixing Klebsiella variicola strain DX120E

    PubMed Central

    2015-01-01

    Klebsiella variicola strain DX120E (=CGMCC 1.14935) is an endophytic nitrogen-fixing bacterium isolated from sugarcane crops grown in Guangxi, China and promotes sugarcane growth. Here we summarize the features of the strain DX120E and describe its complete genome sequence. The genome contains one circular chromosome and two plasmids, and contains 5,718,434 nucleotides with 57.1% GC content, 5,172 protein-coding genes, 25 rRNA genes, 87 tRNA genes, 7 ncRNA genes, 25 pseudo genes, and 2 CRISPR repeats. PMID:26203334

  19. Complete genome sequence of the novel thermophilic polyhydroxyalkanoates producer Aneurinibacillus sp. XH2 isolated from Gudao oilfield in China.

    PubMed

    Xi, Lijun; Zhang, Zhenchong; Qiao, Nenghu; Zhang, Yu; Li, Jing; Zhao, Jing-Yi; Xiao, Zijun

    2016-06-10

    Aneurinibacillus sp. XH2 (CGMCC 1.15535) was isolated from Gudao oilfield in China. It is able to use simple carbon resources to accumulate Polyhydroxyalkanoates (PHAs) in a thermophilic fashion. Here, we describe the genomic features of this strain. The total genome size of Aneurinibacillus sp. XH2 is 3,664,835bp and contains 3441 coding sequences and 114 tRNAs. The annotated genome sequence of this strain provides the genetic basis for revealing its role as a themophilic PHAs producing bacterium. PMID:27046067

  20. Complete genome sequence of Bifidobacterium animalis subsp. lactis A6, a probiotic strain with high acid resistance ability.

    PubMed

    Sun, Erna; Zhao, Liang; Ren, Fazheng; Liu, Songling; Zhang, Ming; Guo, Huiyuan

    2015-04-20

    Bifidobacterium animalis subsp. lactis A6 (BAA6) (CGMCC No. 9273) was a probiotic strain isolated from the feces of a centenarian. Previous study showed that BAA6 had high acid resistance to low pH which is a critical factor influencing its healthy benefits. Elaborating the stress resistant mechanisms of bifidobacteria is important to extensively exploit this probiotic. Here, we reported the complete genome sequence of BAA6 that contains 1,958,651 bp encoding 1622 CDSs, 16 rRNA genes, 52 tRNA genes. PMID:25707999

  1. Mutation-Screening of Pleurotus Ferulae with High Temperature Tolerance by Nitrogen Ion Implantation

    NASA Astrophysics Data System (ADS)

    Chen, Henglei; Wan, Honggui; Zhang, Jun; Zeng, Xianxian

    2008-08-01

    In order to obtain Pleurotus ferulae with high temperature tolerance, conidiophores of wild type strain ACK were implanted with nitrogen ions in energy of 5 ~15 keV and dose of 1.5 × 1015 ~ 1.5 × 1016 cm-2, and a mutant CGMCC1763 was isolated subsequently through thermotolerant screening method. It was found that during riper period the surface layer mycelium of the mutant in mushroom bag wasn't aging neither grew tegument even above 30° C. The mycelium endurable temperature of the mutant was increased by 5°C compared to that of the wild type strain. The fruiting bodies growth temperature of the mutant was 18 ~22°C in daytime and 8~14°C at night. The highest growth temperature of fruiting bodies of the mutant was increased about 7°C w.r.t. that of original strain. Through three generations investigations, it was found that the mutant CGMCC1763 was stable with high temperature tolerance.

  2. Transcriptional characteristics associated with lichenysin biosynthesis in Bacillus licheniformis from Chinese Maotai-flavor liquor making.

    PubMed

    Wu, Qun; Zhang, Rong; Peng, Suqin; Xu, Yan

    2015-01-28

    This work investigated the biosynthetic mechanism of lichenysin, the newly identified nonvolatile matrix component in Chinese liquors. Transcriptomes were analyzed in three producers, Bacillus licheniformis CGMCC 3961, 3962, and 3963, which were isolated from Maotai-flavor liquor-making process and produced 386.3, 553.5, and 795.2 μg/L lichenysin in a simulative liquor fermentation process. Lichenysin synthetase genes lchAA-AD in these three producers were expressed much more highly than those of the nonproducer B. licheniformis ATCC 14580 (>18.4-fold). In addition, ABC transporters were the most significant responsive metabolic pathway, and the expression levels of peptide transporter genes dppABCDE all increased more than 19.2-fold. When B. licheniformis CGMCC 3963 was cultured in synthetic medium, the expression of dppABCDE and lichenysin both increased with the addition of casein hydrolysate (containing various peptides). This indicated that peptide would act as a substrate for lichenysin synthesis. This work sheds new light on the mechanism for lichenysin biosynthesis. PMID:25561250

  3. An Alternative Approach to Synthesizing Galactooligosaccharides by Cell-Surface Display of β-Galactosidase on Yarrowia lipolytica.

    PubMed

    An, Jin; Zhang, Lebin; Li, Lijuan; Liu, Dawen; Cheng, Huiling; Wang, Hengwei; Nawaz, Muhammad Zohaib; Cheng, Hairong; Deng, Zixin

    2016-05-18

    An alternative strategy for synthesizing galactooligosaccharides (GOS) from an erythritol-producing yeast Yarrowia lipolytica using surface display technology was demonstrated. The engineered strain CGMCC11369 was developed by fusion of the β-galactosidase gene from Aspergillus oryzae to the YlPir1 gene, which codes for a cell wall protein. β-Galactosidase was effectively displayed on the cell surface of Yarrowia lipolytica start strain CGMCC7326. This engineered strain with surface-displayed β-galactosidase efficiently synthesized GOS from lactose. An amount of 160 g/L GOS was produced within 6 h in a solution of 500 g/L lactose and 5 mg/mL cell (dry weight) at pH 5.5 and 60 °C, with a yield of 51% of consumed lactose monohydrate. This newly developed method was applied with waste yeast paste from erythritol industry at least 10 times. The optimal reaction temperature increased to 60 °C, about 20 °C higher than that of free β-galactosidase, which was helpful for enhancing the reaction rate and GOS production. PMID:27090877

  4. Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics

    PubMed Central

    Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

    2015-01-01

    Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains. PMID:26691589

  5. Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

    2015-12-01

    Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains.

  6. Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics.

    PubMed

    Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

    2015-01-01

    Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains. PMID:26691589

  7. Comparison of aroma-active compounds and sensory characteristics of durian (Durio zibethinus L.) wines using strains of Saccharomyces cerevisiae with odor activity values and partial least-squares regression.

    PubMed

    Zhu, JianCai; Chen, Feng; Wang, LingYing; Niu, YunWei; Shu, Chang; Chen, HeXing; Xiao, ZuoBing

    2015-02-25

    The study evaluated the effects of five different strains (GRE, RC212, Lalvin D254, CGMCC2.4, and CGMCC2.23) of the yeast Saccharomyces cerevisiae on the aromatic characteristics of fermented durian musts. In this work, 38 and 43 compounds in durian juices and wines were analyzed by gas chromatography-mass spectrometry (GC-MS) and GC-pulsed flame photometric detection (GC-PFPD) with the aid of stir bar sorptive extraction (SBSE), respectively. According to the measured odor activity values (OAV), only 11 and 15 aroma compounds had OAVs >1 in durian juices or wines, among which 2,3-butanedione, 3-methylbutanol, dimethyl sulfide, dimethyl disulfide, methyl ethyl disulfide, ethyl 2-methylbutanoate, ethyl butanoate, and ethyl octanoate were major contributors to the aroma of juices and wines. Partial least-squares regression (PLSR) was used to detect positive correlations between sensory analysis and aroma compounds. The results showed that the attributes were closely related to aroma compounds. PMID:25620380

  8. Optimization of culture medium compositions for gellan gum production by a halobacterium Sphingomonas paucimobilis.

    PubMed

    Zhang, Jun; Dong, Ya-chen; Fan, Lin-lin; Jiao, Zhi-hua; Chen, Qi-he

    2015-01-22

    The effect of culture medium compositions on gellan gum production produced by fermentation with a halobacterium Sphingomonas paucimobilis QHZJUJW CGMCC2428 was studied. In this work, a fractional factorial design was applied to investigate the main factors that affected gellan gum production by S. paucimobilis QHZJUJW CGMCC2428. Sucrose was the best carbon source for gellan gum and peptone displayed better inducing effect. Central composite design and response surface methodology were adopted to derive a statistical model for optimizing submerged culture medium composition. These experimental results showed that the optimum culture medium for producing gellan gum was composed of 40.00 (w/v) sucrose, 3.00% peptone (w/v), MgSO4 (w/v), 9.20% KH2PO4 (w/v), 7.50% Na2HPO4 (w/v), 4.30% K2SO4 (w/v), pH 6.8-7.0. The maximal gellan gum was 19.89±0.68 g/L, which was agreed closely with the predicated value (20.12 g/L). After incubated for 72 h under the optimized culture medium in 5-L bioreactor, the gellan gum fermentation reached about 19.90±0.68 g/L, which was higher than that in the initial cultivation medium. PMID:25439950

  9. Streptosporangium lutulentum sp. nov., Streptosporangium fenghuangense sp. nov. and Streptosporangium corydalis sp. nov., three novel actinobacterial species isolated from National Forest Park of Fenghuang Mountain.

    PubMed

    Fang, Baozhu; Liu, Hui; Pan, Tong; Liu, Chongxi; Guan, Xuejiao; He, Hairong; Yan, Kai; Li, Jiansong; Xiang, Wensheng; Wang, Xiangjing

    2016-03-01

    Three novel actinobacteria, designated strains NEAU-FSHN1(T), NEAU-hd-3(T) and NEAU-Y6(T), were isolated from a stream base, soil adjacent to the stream and a root of Corydalis yanhusuo L, respectively, collected from Wuchang, Heilongjiang Province, China. A polyphasic study was carried out to establish the taxonomic positions of these strains. The three strains were observed to form scant aerial hyphae that differentiated into spherical spore vesicles. The phylogenetic analysis based on the 16S rRNA gene sequences of strains NEAU-FHSN1(T), NEAU-hd-3(T) and NEAU-Y6(T) showed that the three novel isolates exhibit 99.2 % (NEAU-FHSN1(T)/NEAU-hd-3(T)), 99.2 % (NEAU-FHSN1(T)/NEAU-Y6(T)) and 99.7 % (NEAU-hd-3(T)/NEAU-Y6(T)) 16S rRNA gene sequence similarities with each other and that they are closely related to strains Streptosporangium shengliense NEAU-GH7(T) (sequence similarities 98.72, 98.85, 98.99 %), Streptosporangium roseum DSM 43021(T) (98.65, 98.51, 98.58 %) and Streptosporangium album DSM 43023(T) (98.41, 98.96, 98.89 %). However, the DNA-DNA hybridization values between strains NEAU-FSHN1(T), NEAU-hd-3(T) and NEAU-Y6(T) were 61.2 % (NEAU-FSHN1(T)/NEAU-hd-3(T)), 63.5 % (NEAU-FHSN1(T)/NEAU-Y6(T)) and 65.8 % (NEAU-hd-3(T)/NEAU-Y6(T)), and the values between the three strains and their close phylogenetic relatives were also below 70 %. With reference to phenotypic characteristics, phylogenetic data and DNA-DNA hybridization results, the three strains can be distinguished from each other and their close phylogenetic relatives. Thus, strains NEAU-FHSN1(T), NEAU-hd-3(T) and NEAU-Y6(T) are concluded to represent three novel species of the genus Streptosporangium, for which the names Streptosporangium lutulentum sp. nov., Streptosporangium fenghuangense sp. nov. and Streptosporangium corydalis sp. nov. are proposed. The type strains are NEAU-FHSN1(T) (=CGMCC 4.7141(T) = DSM 46740(T)), NEAU-Y6(T) (=CGMCC 4.7150(T) = DSM 46722(T)) and NEAU-hd3(T) (CGMCC 4.7212(T) = JCM 30058(T)), respectively. PMID:26767659

  10. Ogataea ganodermae sp. nov., a methanol-assimilating yeast species isolated from basidiocarps of Ganoderma sp.

    PubMed

    Ji, Zhao-Hui; Bai, Feng-Yan

    2008-06-01

    Three methanol-utilizing yeast strains were isolated from basidiocarps of Ganoderma sp. collected from a tree trunk in Mangshan Mountain, Hunan Province, southern China. These strains formed hat-shaped ascospores in unconjugated and deliquescent asci. Sequence analysis of the large-subunit rRNA gene D1/D2 domain and internal transcribed spacer (ITS) region, electrophoretic karyotype comparison and phenotypic characterization demonstrated that the three strains represent a novel species of the genus Ogataea, which is described as Ogataea ganodermae sp. nov. (type strain SHS 2.1(T) =CGMCC AS 2.3435(T) =CBS 10646(T)). Phylogenetically, the novel species was closely related to Ogataea pini and Ogataea henricii. The latter two taxa with similar D1/D2 sequences were confirmed to represent separate species by ITS sequence and electrophoretic karyotype comparisons. PMID:18523203

  11. Resistance of Bacillus subtilis spores to 12C ion beams, stimulation of high-energy charged particles in space

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Dang, Bingrong; Li, Junxiong; Chen, Jinsong; Liu, Mei; Liu, Zhiheng; Zhang, Lixin

    To monitor the response of live microbes in space radiation environment with high-energy charged particles, we carry out ground stimulation radiation experiments. Spores of Bacillus (CGMCC 1.1849) species are one of the model systems used for astro- and radiobiological studies. (12) C ion beams served as stimulated space radiation from 5gry, 10gry, 20gry, 40gry, to 80gry at a rate of 15gry/min Death rates are measured and mutant strains are isolated. Five representative strains are analyzed for their corresponding gene sequences, protein sequences and gene expression index of DNA repair system gene recA and recO. The statistic results showed the strains resistance to (12) C ion beams radiation is partially due to the increase of gene expression index of recA and recO. In conclusion, our research provide a surrogate system to monitor the live microbial response in resistant to space radiation environment.

  12. Pantoea pleuroti sp. nov., Isolated from the Fruiting Bodies of Pleurotus eryngii.

    PubMed

    Ma, Yuanwei; Yin, Yonggang; Rong, Chengbo; Chen, Sanfeng; Liu, Yu; Wang, Shouxian; Xu, Feng

    2016-02-01

    Four Gram-negative-staining, facultatively anaerobic bacterial isolates were obtained from the fruiting bodies of the edible mushroom Pleurotus eryngii showing symptoms of bacterial blight disease in Beijing, China. Nearly complete 16S rRNA gene sequencing placed these isolates in the genus Pantoea. Multilocus sequence analysis based on the partial sequences of atpD, gyrB, infB and rpoB revealed Pantoea agglomerans as their closest phylogenetic relatives. DNA-DNA hybridization and phenotypic tests confirmed the classification of the new isolates as a novel species. The name Pantoea pleuroti sp. nov. [type strain KCTC 42084(T) = CGMCC 1.12894(T) = JZB 2120015(T)] is proposed. PMID:26581526

  13. Pantoea hericii sp. nov., Isolated from the Fruiting Bodies of Hericium erinaceus.

    PubMed

    Rong, Chengbo; Ma, Yuanwei; Wang, Shouxian; Liu, Yu; Chen, Sanfeng; Huang, Bin; Wang, Jing; Xu, Feng

    2016-06-01

    Three Gram-negative, facultatively anaerobic bacterial isolates were obtained from the fruiting bodies of the edible mushroom Hericium erinaceus showing symptoms of soft rot disease in Beijing, China. Sequences of partial 16S rRNA gene placed these isolates in the genus Pantoea. Multilocus sequence analysis based on the partial sequences of atpD, gyrB, infB and rpoB revealed P. eucalypti and P. anthophila as their closest phylogenetic relatives and indicated that these isolates constituted a possible novel species. DNA-DNA hybridization studies confirmed the classification of these isolates as a novel species and phenotypic tests allowed for differentiation from the closest phylogenetic neighbours. The name Pantoea hericii sp. nov. [Type strain LMG 28847(T) = CGMCC 1.15224(T) = JZB 2120024(T)] is proposed. PMID:26897127

  14. Evaluation of the formation of volatiles and sensory characteristics of persimmon (Diospyros kaki L.f.) fruit wines using different commercial yeast strains of Saccharomyces cerevisiae.

    PubMed

    Zhu, Jian Cai; Niu, Yun Wei; Feng, Tao; Liu, Sheng Jiang; Cheng, He Xing; Xu, Na; Yu, Hai Yan; Xiao, Zuo Bing

    2014-01-01

    This study evaluated the effects of five strains (IFFI 1346, IFFI 1363, CICC 31482, D254 and CGMCC2.346) of the yeast Saccharomyces cerevisiae on the aromatic profiles of fermented persimmon (Diospyros kaki L.f.) musts. A total of 50 and 60 compounds were identified in persimmon wine by stir bar sorptive extraction coupled with gas chromatography-mass spectrometry. According to odour activity values (OAVs), 26 detected compounds showed an OAV above 1. Principal component analysis explained the distribution of these persimmon wines on the basis of volatile compounds with OAV>1. The volatile compounds with high OAV included ethyl hexanoate, ethyl octanoate, methyl decanoate, linalool and geraniol. Quantitative descriptive analysis was employed. The result showed that persimmon wines fermented with strains IFFI 1363 and D254 were strongly correlated with persimmon, aroma harmony, fruity, fusel and taste balanced, fullness, hedonic scale. Therefore, the two yeast strains could be used as starter culture for persimmon wine production. PMID:25186058

  15. Reclassification of Saccharomycodes sinensis, Proposal of Yueomyces sinensis gen. nov., comb. nov. within Saccharomycetaceae (Saccharomycetales, Saccharomycotina)

    PubMed Central

    Wang, Long; Groenewald, Marizeth; Wang, Qi-Ming; Boekhout, Teun

    2015-01-01

    The phylogenetic position of Saccharomycodes sinensis has been debated by yeast taxonomists. In this study, a multigene phylogenetic analysis based on four regions, namely the 18S ribosomal DNA (rDNA), the D1/D2 domains of the 26S rDNA, the second largest subunit of RNA polymerase II gene (RPB2) and translation elongation factor 1-α gene (EF1-α), were performed to address the phylogenetic placement of S. sinensis. Our result indicated that S. sinensis belongs to Saccharomycetaceae instead of Saccharomycodaceae, and forms a single species lineage divergent from the other genera within Saccharomycetaceae. Yueomyces gen. nov. (MycoBank No. MB 811648) is proposed in the Saccharomycetaceae with Y. sinensis comb. nov. (MycoBank No. MB 811649, type strain CGMCC 2.01395T = IFO 10111T = CBS 7075T) as the type species. PMID:26375944

  16. Complete genome sequence of Streptococcus thermophilus MN-BM-A01, a strain with high exopolysaccharides production.

    PubMed

    Bai, Ying; Sun, Erna; Shi, Yudong; Jiang, Yunyun; Chen, Yun; Liu, Songling; Zhao, Liang; Zhang, Ming; Guo, Huiyuan; Zhang, Hao; Mu, Zhishen; Ren, Fazheng

    2016-04-20

    Streptococcus thermophilus MN-BM-A01 (ST MN-BM-A01) (CGMCC No. 11383) was a strain isolated from Yogurt Block in Gansu, China. The yogurt fermented with this strain has good flavor, acidity, and viscosity. Moreover, ST MN-BM-A01 could produce a high level of EPS which can confer the yogurt with improved rheological properties. We reported the complete genome sequence of ST MN-BM-A01 that contains 1,876,516bp encoding 1704 coding sequences (CDSs), 67 tRNA genes and 6 rRNA operons. The genomic sequence indicated that this strain included a 35.3-kb gene cluster involved in EPS biosynthesis. PMID:26956372

  17. Molecular Phylogenetic Analysis of Ballistoconidium-Forming Yeasts in Trichosporonales (Tremellomycetes): A Proposal for Takashimella gen. nov. and Cryptotrichosporon tibetense sp. nov.

    PubMed Central

    Wang, Long; Wang, Qi-Ming

    2015-01-01

    Bullera species in the Trichosporonales (Tremellomycetes, Agaricomycotina) are phylogenetically distinct from Bullera alba (teleomorph: Bulleromyces albus), the type species of Bullera that belongs to Tremellales. In the present study, the three Bullera species, namely Bullera formosensis, Bullera koratensis and Bullera lagerstroemiae, and Cryptococcus tepidarius belonging to the Trichosporonales are transferred into a new genus Takashimella gen. nov. (MycoBank No. MB 810672) based on sequence analysis of the small subunit (SSU) rRNA gene, the D1/D2 domains of large subunit (LSU) rRNA gene and the ITS+5.8S rRNA gene sequences. In addition, the genus Cryptotrichosporon is emended to accommodate a novel ballistoconidium-forming species of the Trichosporonales, which is named as Cryptotrichosporon tibetense (type strain CGMCC 2.02614T = CBS 10455T). The MycoBank number of this new species is MB 810688. PMID:26200459

  18. Production of nano bacterial cellulose from waste water of candied jujube-processing industry using Acetobacter xylinum.

    PubMed

    Li, Zheng; Wang, Lifen; Hua, Jiachuan; Jia, Shiru; Zhang, Jianfei; Liu, Hao

    2015-04-20

    The work is aimed to investigate the suitability of waste water of candied jujube-processing industry for the production of bacterial cellulose (BC) by Gluconacetobacter xylinum CGMCC No.2955 and to study the structure properties of bacterial cellulose membranes. After acid pretreatment, the glucose of hydrolysate was higher than that of waste water of candied jujube. The volumetric yield of bacterial cellulose in hydrolysate was 2.25 g/L, which was 1.5-folds of that in waste water of candied jujube. The structures indicated that the fiber size distribution was 3-14 nm in those media with an average diameter being around 5.9 nm. The crystallinity index of BC from pretreatment medium was lower than that of without pretreatment medium and BCs from various media had similar chemical binding. Ammonium citrate was a key factor for improving production yield and the crystallinity index of BC. PMID:25662694

  19. Genome mining-directed activation of a silent angucycline biosynthetic gene cluster in Streptomyces chattanoogensis.

    PubMed

    Zhou, Zhenxing; Xu, Qingqing; Bu, Qingting; Guo, Yuanyang; Liu, Shuiping; Liu, Yu; Du, Yiling; Li, Yongquan

    2015-02-01

    Genomic sequencing of actinomycetes has revealed the presence of numerous gene clusters seemingly capable of natural product biosynthesis, yet most clusters are cryptic under laboratory conditions. Bioinformatics analysis of the completely sequenced genome of Streptomyces chattanoogensis L10 (CGMCC 2644) revealed a silent angucycline biosynthetic gene cluster. The overexpression of a pathway-specific activator gene under the constitutive ermE* promoter successfully triggered the expression of the angucycline biosynthetic genes. Two novel members of the angucycline antibiotic family, chattamycins A and B, were further isolated and elucidated. Biological activity assays demonstrated that chattamycin B possesses good antitumor activities against human cancer cell lines and moderate antibacterial activities. The results presented here provide a feasible method to activate silent angucycline biosynthetic gene clusters to discover potential new drug leads. PMID:25511454

  20. Fabivirga thermotolerans gen. nov., sp. nov., a novel marine bacterium isolated from culture broth of a marine cyanobacterium.

    PubMed

    Tang, M; Chen, C; Li, J; Xiang, W; Wu, H; Wu, J; Dai, S; Wu, H; Li, T; Wang, G

    2016-02-01

    A Gram-stain-negative, red, non-spore-forming, strictly aerobic bacterium, designated strain A4T, was isolated from culture broth of a marine cyanobacterium. Cells were flexible rods with gliding motility. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain A4T formed a coherent cluster with members of the genera Roseivirga and Fabibacter, and represents a distinct lineage in the family Flammeovirgaceae. Thermotolerance and a distinctive cellular fatty acid profile could readily distinguish this isolate from any bacteria of the genera Roseivirga and Fabibacter with a validly published name. On the basis of the phenotypic, chemotaxonomic and phylogenetic characteristics, strain A4T is suggested to represent a novel species in a novel genus, for which the name Fabivirga thermotolerans gen. nov., sp. nov. is proposed. The type strain is A4T ( = KCTC 42507T = CGMCC 1.15111T). PMID:26652750

  1. Phylogenomic analysis shows that ‘Bacillus vanillea’ is a later heterotypic synonym of Bacillus siamensis.

    PubMed

    Dunlap, Christopher A

    2015-10-01

    ‘Bacillus vanillea’ XY18 ( = CGMCC 8629 = NCCB 100507) was isolated from cured vanilla beans and involved in the formation of vanilla aroma compounds. A draft genome of this strain was assembled and yielded a length of 3.71 Mbp with a DNA G+C content of 46.3 mol%. Comparative genomic analysis with its nearest relatives showed only minor differences between this strain and the genome of the Bacillus siamensis KCTC 13613T ( = BCC 22614T = KACC 16244T), with a calculated DNA–DNA hybridization (DDH) value of 91.2 % and an average nucleotide identity (ANI) of 98.9 %. This DDH value is well above the recommended 70 % threshold for species delineation, as well as the ANI threshold of 95 %. In addition, the results of morphological, physiological, chemotaxonomic and phylogenetic analyses indicate that the type strains of these two taxa are highly similar with phenotype coherence. A core genome multi-locus sequencing analysis was conducted for the strains and the results show that ‘Bacillus vanillea’ XY18 clusters closely to the type strain of Bacillus siamensis. Therefore, it is proposed that the species ‘Bacillus vanillea’ XY18 ( = CGMCC 8629 = NCCB 100507) should be reclassified as a later heterotypic synonym of Bacillus siamensis KCTC 13613T ( = BCC 22614T = KACC 16244T). An emended description of Bacillus siamensis is provided. PMID:26296875

  2. Proteomic profiling of Bacillus licheniformis reveals a stress response mechanism in the synthesis of extracellular polymeric flocculants.

    PubMed

    Yu, Wencheng; Chen, Zhen; Shen, Liang; Wang, Yuanpeng; Li, Qingbiao; Yan, Shan; Zhong, Chuan-Jian; He, Ning

    2016-04-01

    Some bioflocculants composed of extracellular polymeric substances are produced under peculiar conditions. Bacillus licheniformis CGMCC2876 is a microorganism that secretes both extracellular polysaccharides (EPS) and poly-gamma-glutamic acid (γ-PGA) under stress conditions. In this work, SWATH acquisition LC-MS/MS method was adopted for differential proteomic analysis of B. licheniformis, aiming at determining the bacterial stress mechanism. Compared with LB culture, 190 differentially expressed proteins were identified in B. licheniformis CGMCC2876 cultivated in EPS culture, including 117 up-regulated and 73 down-regulated proteins. In γ-PGA culture, 151 differentially expressed proteins, 89 up-regulated and 62 down-regulated, were found in the cells. Up-regulated proteins involved in amino acid biosynthesis were found to account for 43% and 41% of the proteomes in EPS and γ-PGA cultivated cells, respectively. Additionally, a series of proteins associated with amino acid degradation were found to be repressed under EPS and γ-PGA culture conditions. Transcriptional profiling via the qPCR detection of selected genes verified the proteomic analysis. Analysis of free amino acids in the bacterial cells further suggested the presence of amino acid starvation conditions. EPS or γ-PGA was synthesized to alleviate the effect of amino acid limitation in B. licheniformis. This study identified a stress response mechanism in the synthesis of macromolecules in B. licheniformis, providing potential culture strategies to improve the production of two promising bioflocculants. Biotechnol. Bioeng. 2016;113: 797-806. © 2015 Wiley Periodicals, Inc. PMID:26388297

  3. Halorussus amylolyticus sp. nov., isolated from an inland salt lake.

    PubMed

    Yuan, Pan-Pan; Ye, Wei-Tao; Pan, Jia-Xiang; Han, Dong; Zhang, Wen-Jiao; Cui, Heng-Lin

    2015-10-01

    A halophilic archaeal strain, YC93T, was isolated from Yuncheng salt lake in Shanxi Province, China. Cells were pleomorphic rods, stained Gram-negative and formed light-red-pigmented colonies on agar plates. Strain YC93T was able to grow at 25–50 °C (optimum 37 °C), with 1.4–4.8 M NaCl (optimum 2.0 M), with 0–1.0 M MgCl2 (optimum 0.05 M) and at pH 6.0–9.5 (optimum pH 7.0). Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8 % (w/v). 16S rRNA gene sequence analysis revealed that strain YC93T had two dissimilar 16S rRNA genes both of which were phylogenetically related to those of the two recognized members of the genus Halorussus (93.0–95.3 % similarity). The rpoB′ gene of strain YC93T was phylogenetically related to the corresponding gene of Halorussus rarus TBN4T (91.3 % similarity) and Halorussus ruber YC25T (90.5 %). The major polar lipids were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and five glycolipids chromatographically identical to those of Halorussus rarus CGMCC 1.10122T. The DNA G+C content of strain YC93T was 64.6 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YC93T represents a novel species of the genus Halorussus, for which the name Halorussus amylolyticus sp. nov. is proposed. The type strain is YC93T ( = CGMCC 1.12126T = JCM 18367T). PMID:26228463

  4. Pelagibacterium halotolerans gen. nov., sp. nov. and Pelagibacterium luteolum sp. nov., novel members of the family Hyphomicrobiaceae.

    PubMed

    Xu, Xue-Wei; Huo, Ying-Yi; Wang, Chun-Sheng; Oren, Aharon; Cui, Heng-Lin; Vedler, Eve; Wu, Min

    2011-08-01

    Two Gram-negative, motile, aerobic bacterial strains, designated B2(T) and 1_C16_27(T), were respectively isolated from a seawater sample collected from the East China Sea and a semi-coke sample from north-eastern Estonia. Their genetic, phenotypic and chemotaxonomic properties were studied. The isolates were short rods with polar flagella and were positive for catalase and oxidase activities. Q-10 was the predominant respiratory ubiquinone. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol and two unidentified glycolipids. The major fatty acids were nonadecanoic (C(19 : 0) cyclo), octadecanoic (C(18 : 0) and C(18 : 0) 3-OH), octadecenoic (C(18 : 1)) and hexadecanoic (C(16 : 0)) acids. The G+C content of the genomic DNA was 58.1-59.3 mol%. 16S rRNA gene sequence analysis revealed that the two isolates represent a distinct lineage within the family Hyphomicrobiaceae. The phylogenetically closest relatives were Cucumibacter (92.7-93.7 % 16S rRNA gene sequence similarity), Devosia (92.9-94.4 %) and Zhangella (91.7-92.1 %). Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strains B2(T) and 1_C16_27(T) could be differentiated from each other and from members of the genera Cucumibacter, Devosia and Zhangella. Therefore, it is proposed that strains B2(T) and 1_C16_27(T) represent two novel species in a new genus, for which the names Pelagibacterium halotolerans gen. nov., sp. nov. (the type species; type strain B2(T)  = CGMCC 1.7692(T)  = JCM 15775(T)) and Pelagibacterium luteolum sp. nov. (type strain 1_C16_27(T)  = CGMCC 1.10267(T)  = JCM 16552(T)  = CELMS EEUT 1C1627(T)) are proposed. PMID:20817840

  5. Sphingomonas qilianensis sp. nov., Isolated from Surface Soil in the Permafrost Region of Qilian Mountains, China.

    PubMed

    Piao, Ai-Lian; Feng, Xiao-Min; Nogi, Yuichi; Han, Lu; Li, Yonghong; Lv, Jie

    2016-04-01

    A Gram-stain-negative, strictly aerobic, non-motile and rod-shaped bacterial strain, designated X1(T), was isolated from the permafrost region of Qilian Mountains in northwest of China. Phylogenetic analyses of 16S rRNA gene sequence revealed that strain X1(T) was a member of the genus Sphingomonas and shared the highest 16S rRNA gene sequence similarity with Sphingomonas oligophenolica JCM 12082(T) (96.9 %), followed by Sphingomonas glacialis CGMCC 1.8957(T) (96.7 %) and Sphingomonas alpina DSM 22537(T) (96.4 %). Strain X1(T) was able to grow at 15-30 °C, pH 6.0-10.0 and with 0-0.3 % NaCl (w/v). The DNA G+C content of the isolate was 64.8 mol%. Strain X1(T)-contained Q-10 as the dominant ubiquinone and C18:1 ω7c, C16:1 ω7c, C16:0 and C14:0 2-OH as the dominant fatty acids. The polar lipid profile of strain XI(T)-contained sphingoglycolipid, phosphatidylglycerol, phosphatidylethanolamine, one unidentified glycolipid and two unidentified phospholipid. Due to the phenotypic and genetic distinctiveness and other characteristic studied in this article, we consider X1(T) as a novel species of the genus Sphingomonas and propose to name it Sphingomonas qilianensis sp. nov. The type strain is X1(T) (=CGMCC 1.15349(T) = KCTC 42862(T)). PMID:26676296

  6. Two new species of the genus Micromonospora: Micromonospora palomenae sp. nov. and Micromonospora harpali sp. nov. isolated from the insects.

    PubMed

    Fang, Baozhu; Liu, Chongxi; Guan, Xuejiao; Song, Jia; Zhao, Junwei; Liu, Hui; Li, Chuang; Ning, Wenxi; Wang, Xiangjing; Xiang, Wensheng

    2015-07-01

    Two novel actinobacteria, strains NEAU-CX1(T) and NEAU-JC6(T), were isolated from nymphs of stinkbug (Palomena viridissima Poda) and a beetle (Harpalus sinicus Hope), respectively, collected from Harbin, Heilongjiang Province, China. A polyphasic study was carried out to establish the taxonomic positions of these strains. The phylogenetic analysis based on 16S rRNA gene sequence of strain NEAU-CX1(T) showed it to be most closely related to Micromonospora coxensis JCM 13248(T) (99.3 % sequence similarity), Micromonospora purpureochromogenes DSM 43821(T) (99.1 %) and Micromonospora halophytica JCM 3125(T) (98.6 %), and that of strain NEAU-JC6(T) to Micromonospora haikouensis DSM 45626(T) (99.3 %), Micromonospora carbonacea JCM 3139(T) (99.1 %) and Micromonospora krabiensis JCM 12869(T) (99.1 %). The phylogenetic analysis based on gyrB gene sequence of strain NEAU-CX1(T) showed it to be most closely related to M. purpureochromogenes DSM 43821(T) (98.0 % sequence similarity), and that of strain NEAU-JC6(T) to M. haikouensis DSM 45626(T) (99.0 %) and M. carbonacea JCM 3139(T) (98.0 %). A combination of DNA-DNA hybridization results and cultural and physiological properties indicated that the two strains can be distinguished from their closest phylogenetic relatives. Thus, strains NEAU-CX1(T) and NEAU-JC6(T) represent two novel species of the genus Micromonospora, for which the names Micromonospora palomenae sp. nov. and Micromonospora harpali sp. nov. are proposed. The type strains are NEAU-CX1(T) (=CGMCC 4.7175(T) = JCM 30056(T)) and NEAU-JC6(T) (=CGMCC 4.7173(T) = JCM 30055(T)). PMID:25957972

  7. Growth in Stewart's medium is a simple, rapid and inexpensive screening tool for the identification of Burkholderia cepacia complex.

    PubMed

    Vanlaere, Elke; Hansraj, Faiza; Vandamme, Peter A R; Govan, John R W

    2006-05-01

    Ninety-one percent of Burkholderia cepacia complex reference strains (66 out of 72) displayed a yellow slope-green butt colour reaction after growth in Stewart's medium indicating the oxidation of glucose and the absence of an arginine dihydrolase system. This same colour reaction was observed for Burkholderia gladioli and several Ralstonia species, but not for Pseudomonas aeruginosa, Stenotrophomonas, Achromobacter, Pandoraea and several other Gram-negative non-fermenting bacilli. We therefore consider growth in Stewart's medium a useful, simple, rapid and inexpensive screening test to reduce the number of false positive isolates from B. cepacia complex selective media. PMID:16386966

  8. Characterization of copper-resistant bacteria and bacterial communities from copper-polluted agricultural soils of central Chile

    PubMed Central

    2012-01-01

    Background Copper mining has led to Cu pollution in agricultural soils. In this report, the effects of Cu pollution on bacterial communities of agricultural soils from Valparaiso region, central Chile, were studied. Denaturing gradient gel electrophoresis (DGGE) of the 16S rRNA genes was used for the characterization of bacterial communities from Cu-polluted and non-polluted soils. Cu-resistant bacterial strains were isolated from Cu-polluted soils and characterized. Results DGGE showed a similar high number of bands and banding pattern of the bacterial communities from Cu-polluted and non-polluted soils. The presence of copA genes encoding the multi-copper oxidase that confers Cu-resistance in bacteria was detected by PCR in metagenomic DNA from the three Cu-polluted soils, but not in the non-polluted soil. The number of Cu-tolerant heterotrophic cultivable bacteria was significantly higher in Cu-polluted soils than in the non-polluted soil. Ninety two Cu-resistant bacterial strains were isolated from three Cu-polluted agricultural soils. Five isolated strains showed high resistance to copper (MIC ranged from 3.1 to 4.7 mM) and also resistance to other heavy metals. 16S rRNA gene sequence analyses indicate that these isolates belong to the genera Sphingomonas, Stenotrophomonas and Arthrobacter. The Sphingomonas sp. strains O12, A32 and A55 and Stenotrophomonas sp. C21 possess plasmids containing the Cu-resistance copA genes. Arthrobacter sp. O4 possesses the copA gene, but plasmids were not detected in this strain. The amino acid sequences of CopA from Sphingomonas isolates (O12, A32 and A55), Stenotrophomonas strain (C21) and Arthrobacter strain (O4) are closely related to CopA from Sphingomonas, Stenotrophomonas and Arthrobacter strains, respectively. Conclusions This study suggests that bacterial communities of agricultural soils from central Chile exposed to long-term Cu-pollution have been adapted by acquiring Cu genetic determinants. Five bacterial isolates showed high copper resistance and additional resistance to other heavy metals. Detection of copA gene in plasmids of four Cu-resistant isolates indicates that mobile genetic elements are involved in the spreading of Cu genetic determinants in polluted environments. PMID:22950448

  9. Antibiotic-Resistant Gram-Negative Bacterial Infections in Patients With Cancer

    PubMed Central

    Perez, Federico; Adachi, Javier; Bonomo, Robert A.

    2014-01-01

    Patients with cancer are at high risk for infections caused by antibiotic resistant gram-negative bacteria. In this review, we summarize trends among the major pathogens and clinical syndromes associated with antibiotic resistant gram-negative bacterial infection in patients with malignancy, with special attention to carbapenem and expanded-spectrum β-lactam resistance in Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia—all major threats to our cancer patients. Optimal therapy for these antibiotic-resistant pathogens still remains to be determined. PMID:25352627

  10. Culture-dependent and culture-independent analysis of hydrocarbonoclastic microorganisms indigenous to hypersaline environments in Kuwait.

    PubMed

    Al-Mailem, Dina; Eliyas, Mohamed; Khanafer, Majeda; Radwan, Samir

    2014-05-01

    The halophilic, hydrocarbonoclastic bacteria and archaea inhabiting two hypersaline coastal areas in Kuwait, one in the north and the other in the south, were counted and characterized. Environmental parameters in both areas were similar, with the exception of the soil organic carbon content, which was in the north higher than in the south. The hydrocarbonoclastic bacterial and haloarchaeal numbers and identities as analyzed using nutrient media of various salinities were similar in soil and pond water samples from both areas. The bacterial species recorded by this culture-dependent method belonged to the genera Halomonas, Chromohalobacter, Marinobacter, Exiguobacterium, Stenotrophomonas, Pseudomonas, Salinivibrio, and Bacillus. The haloarchaeal species belonged to the genera Haloferax and Halobacterium. When analyzed by fingerprinting of their amplified genomic DNA followed by sequencing of the electrophoresis-resolved bands, the same environmental samples revealed a different microbial composition. Bacterial phylotypes recorded by this culture-independent method were affiliated with the genera Ochrobactrum, Stenotrophomonas, Rhodococcus, and "Halomicrobium," whereas the archaeal phylotypes were affiliated with Halorussus, Halomicrobium, and Halorientalis. The observed diversity and composition similarity of the hydrocarbonocalastic microflora in both hypersaline areas suggest an effective potential for oil mineralization therein. This potential has been confirmed experimentally. PMID:24682340

  11. Prevalence and diversity of carbapenem-resistant bacteria in untreated drinking water in Portugal.

    PubMed

    Henriques, Isabel S; Araújo, Susana; Azevedo, Juliana S N; Alves, Marta Salgueiro; Chouchani, Chedly; Pereira, Anabela; Correia, António

    2012-10-01

    We examined the prevalence and diversity of carbapenem-resistant bacteria (CRB) in untreated drinking water. Prevalence was estimated in plate count agar (PCA) and R2A media with or without antibiotics. Clonal relatedness of isolates was established by repetitive extragenic palindroitic (REP)-PCR. Phylogeny was based on the 16S rRNA gene. Antimicrobial susceptibility was assessed by disc diffusion methods. Genes encoding beta-lactamases and integrases were inspected by PCR. CRB ranged from 0.02% to 15.9% of cultivable bacteria, while ampicillin-resistant bacteria ranged from 1.5% to 31.4%. Carbapenem-resistant isolates affiliated with genera Stenotrophomonas, Pseudomonas, Janthinobacterium, Chryseobacterium, Sphingobacterium, Acidovorax, Caulobacter, Cupriavidus, and Sphingomonas. CRB were highly resistant to beta-lactams, but mostly susceptible to other classes. Transmissible beta-lactamase genes and integrase genes were not detected. The genus-specific bla(L1) was detected in 61% of the Stenotrophomonas isolates. Contrarily to what has been reported for extensively used antibiotics, low levels of carbapenem resistance were detected in untreated drinking water, often represented by intrinsically resistant genera. Production of chromosomal-encoded carbapenemases was the prevalent carbapenem resistance mechanism. Results suggest that the dissemination of anthropogenic-derived carbapenem resistance is at an early stage. This presents an opportunity to rationally develop monitoring strategies to identify dissemination routes and assess the impact of human actions in the environmental resistome. PMID:22663561

  12. Distinct diversity of the czcA gene in two sedimentary horizons from a contaminated estuarine core.

    PubMed

    Kaci, Assia; Petit, Fabienne; Lesueur, Patrick; Boust, Dominique; Vrel, Anne; Berthe, Thierry

    2014-09-01

    In estuarine ecosystems, trace metals are mainly associated with fine grain sediments which settle on mudflats. Over time, the layers of sediments accumulate and are then transformed by diagenetic processes, recording the history of the estuary's chemical contamination. In such a specific environment, we investigated to what extent a chronic exposure to contaminants could affect metal-resistant sedimentary bacteria in subsurface sediments. The occurrence and diversity of cadmium resistance genes (cadA, czcA) was investigated in 5- and 33-year-old sediments from a highly contaminated estuary (Seine France). Primers were designed to detect a 252-bp fragment of the czcA gene, specifically targeting a transmembrane helice domain (TMH IV) involved in the proton substrate antiport of this efflux pump. Although the cadA gene was not detected, the highest diversity of the sequence of the czcA gene was observed in the 5-year-old sediment. According to the percentage of identity at the amino acid level, the closest CzcA relatives were identified among Proteobacteria (α, β, γ, and δ), Verrucomicrobia, Nitrospirae, and Bacteroidetes. The most abundant sequences were affiliated with Stenotrophomonas. In contrast, in the 33-year-old sediment, CzcA sequences were mainly related to Rhodanobacter thiooxydans and Stenotrophomonas, suggesting a shaping of the metal-resistant microbial communities over time by both diagenetic processes and trace metal contamination. PMID:24894751

  13. Nonylphenol biodegradation, functional gene abundance and bacterial community in bioaugmented sediment: effect of external carbon source.

    PubMed

    Wang, Zhao; Dai, Yu; Zhao, Qun; Li, Ningning; Zhou, Qiheng; Xie, Shuguang

    2015-08-01

    Nonylphenol (NP) biodegradation in river sediment using Stenotrophomonas strain Y1 and Sphingobium strain Y2 were proved to be an effective strategy to remediate NP pollution in our earlier study. The purpose of this study is to investigate the influence of glucose addition on their ability to degrade NP in both liquid cultures and sediment microcosms. The shift in bacterial community structure and relative abundance of NP degraders in sediment microcosms were characterized using terminal restriction fragment length polymorphism analysis. The proportion of NP-degrading alkB and sMO genes was assessed using quantitative polymerase chain reaction (PCR) assay. The growth of Stenotrophomonas strain Y1 and its NP biodegradation efficiency were inhibited by glucose supplementation, while the relative abundance of alkB gene increased. However, NP degradation, as well as the growth of added degraders and proportion of sMO gene, was enhanced in the glucose-amended sediment microcosms inoculated with Sphingobium strain Y2. Moreover, external glucose addition altered bacterial community structures in bioaugmented sediment microcosms, depending on the level of glucose dosage. PMID:25874439

  14. Biodegradation of geosmin in drinking water by novel bacteria isolated from biologically active carbon.

    PubMed

    Zhou, Beihai; Yuan, Rongfang; Shi, Chunhong; Yu, Liying; Gu, Junnong; Zhang, Chunlei

    2011-01-01

    Three strains of Gram-negative bacteria capable of removing geosmin from drinking water were isolated from biologically active carbon and identified to be Chryseobacterium sp., Sinorhizobium sp. and Stenotrophomonas sp. based on physio-biochemistry analysis and 16S rRNA gene sequence analysis. Removal efficiencies of 2 mg/L geosmin in mineral salts medium were 84.0%, 80.2% and 74.4% for Chryseobacterium sp., Sinorhizobium sp. and Stenotrophomonas sp., respectively, while removal efficiencies of 560 ng/L geosmin in filter influent were 84.8%, 82.3% and 82.5%, respectively. The biodegradation of geosmin was determined to be a pseudo first-order reaction, with rate constants at 2 mg/L and 560 ng/L being 0.097 and 0.086 day(-1), 0.089 and 0.084 day(-1), 0.074 and 0.098 day(-1) for the above mentioned degraders, respectively. The biomass of culture in the presence of geosmin was much higher than that in the absence of geosmin. PMID:21790055

  15. Restricted streptomycin use in apple orchards did not adversely alter the soil bacteria communities

    PubMed Central

    Walsh, Fiona; Smith, Daniel P.; Owens, Sarah M.; Duffy, Brion; Frey, Jürg E.

    2014-01-01

    Streptomycin has been authorized for restricted use in the prevention of the fire blight disease of pome fruit orchards in the EU and Switzerland. This study addresses the important topic of the influence of the use of streptomycin in agriculture on the total bacteria community within the soil ecosystem. Soil samples were taken from soils under apple trees, prior to streptomycin application and 2 weeks post streptomycin application or water application (untreated control). High throughput 16S rRNA gene amplicon sequencing was used to generate datasets from the soils under apple trees in apple orchards from three different locations in Switzerland. We hypothesized that the use of streptomycin would reduce the bacterial diversity within the soil samples and enhance a reduction in the variety of taxa present. Bacterial species such as Pseudomonas, Burkholderia, and Stenotrophomonas are intrinsically resistant to many antibiotics and as such it is of interest to investigate if the use of streptomycin provided a selective advantage for these bacteria in the soil ecosystem. The application of streptomycin did not influence the abundance and diversities of major bacteria taxa of the soils or the Pseudomonas, Burkholderia, and Stenotrophomonas species. We also discovered that apple orchards under the same management practices, did not harbor the same bacterial communities. The restricted application of streptomycin in the protection of apple orchards from the fire blight pathogen Erwinia amylovora under the guidelines in Switzerland did not alter either the bacterial diversity or abundance within these soil ecosystems. PMID:24550889

  16. Diversity, metal resistance and uranium sequestration abilities of bacteria from uranium ore deposit in deep earth stratum.

    PubMed

    Islam, Ekramul; Sar, Pinaki

    2016-05-01

    Metal resistance and uranium (U) sequestration abilities of bacteria residing in subsurface U ore was investigated using 122 pure culture strains isolated through enrichment. The cumulative frequencies of isolates resistant to each metal tested were as follows: As(V), 74%; Zn, 58%; Ni, 53%; Cd, 47%; Cr(VI), 41%; Co, 40%; Cu, 20%; and Hg, 4%. 16S rRNA gene analysis revealed that isolated bacteria belonged to 14 genera with abundance of Arthrobacter, Microbacterium, Acinetobacter and Stenotrophomonas. Cobalt did not interfere with the growth of most of the bacterial isolates belonging to different groups while U allowed growth of four different genera of which Stenotrophomonas and Microbacterium showed high U tolerance. Interestingly, tolerance to Ni, Zn, Cu, and Hg was observed only in Microbacterium, Arthrobacter, Paenibacillus¸ and Acinetobacter, respectively. However, Microbacterium was found to be dominant when isolated from other five different metal enrichments including U. Uranium removal study showed that 84% of the test bacteria could remove more than 50mgUg(-1) dry weight from 80 or 160mgL(-1) U within 48h. In general, Microbacterium, Arthrobacter and Acinetobacter could remove a higher amount of U. High resolution transmission electron microscopy (HRTEM) study of U exposed cells revealed that accumulated U sequestered mostly around the cell periphery. The study highlights that indigenous U ore deposit bacteria have the potential to interact with U, and thus could be applied for bioremediation of U contaminated sites or wastes. PMID:26796528

  17. Restricted streptomycin use in apple orchards did not adversely alter the soil bacteria communities.

    PubMed

    Walsh, Fiona; Smith, Daniel P; Owens, Sarah M; Duffy, Brion; Frey, Jürg E

    2013-01-01

    Streptomycin has been authorized for restricted use in the prevention of the fire blight disease of pome fruit orchards in the EU and Switzerland. This study addresses the important topic of the influence of the use of streptomycin in agriculture on the total bacteria community within the soil ecosystem. Soil samples were taken from soils under apple trees, prior to streptomycin application and 2 weeks post streptomycin application or water application (untreated control). High throughput 16S rRNA gene amplicon sequencing was used to generate datasets from the soils under apple trees in apple orchards from three different locations in Switzerland. We hypothesized that the use of streptomycin would reduce the bacterial diversity within the soil samples and enhance a reduction in the variety of taxa present. Bacterial species such as Pseudomonas, Burkholderia, and Stenotrophomonas are intrinsically resistant to many antibiotics and as such it is of interest to investigate if the use of streptomycin provided a selective advantage for these bacteria in the soil ecosystem. The application of streptomycin did not influence the abundance and diversities of major bacteria taxa of the soils or the Pseudomonas, Burkholderia, and Stenotrophomonas species. We also discovered that apple orchards under the same management practices, did not harbor the same bacterial communities. The restricted application of streptomycin in the protection of apple orchards from the fire blight pathogen Erwinia amylovora under the guidelines in Switzerland did not alter either the bacterial diversity or abundance within these soil ecosystems. PMID:24550889

  18. Rapid identification of metallo- and serine beta-lactamases.

    PubMed

    Payne, D J; Cramp, R; Bateson, J H; Neale, J; Knowles, D

    1994-05-01

    Simple methods to detect, identify, and differentiate metallo- and serine beta-lactamases were developed and used to differentiate enzymes produced by 17 clinical isolates of Xanthomonas maltophilia. All isolates exhibited beta-lactamase activity, and in 16 strains this was induced by imipenem. All but one isolate hydrolyzed imipenem (and meropenem), and in all cases this activity was inhibited by 1 mM EDTA. The metallo- and serine beta-lactamases in the cell extracts were distinguished on isoelectric focusing (IEF) gels by using the following procedures. (i) Cell lysates were preincubated with 83 mM EDTA prior to IEF and subsequent visualization with nitrocefin, and (ii) after IEF, the gels were overlaid with either 1 mM zinc sulfate or 100 microM BRL 42715 before staining with nitrocefin. Bands of beta-lactamase activity which were removed by BRL 42715 but unaffected by EDTA or zinc sulfate were categorized as serine beta-lactamases. Bands which were unaffected by BRL 42715 but inhibited by EDTA or enhanced by zinc sulfate were classified as metallo-beta-lactamases. By using this approach, seven metallo-beta-lactamases were differentiated with pI values of 4.8 (two strains), 5.5 (four strains), 5.7 (one strain), 6.0 (one strain), 6.4 (four strains), 6.6 (one strain), and 6.8 (three strains). The metallo-beta-lactamase band with a pI of 6.4 aligned with the recently characterized metallo-beta-lactamase from X. maltophilia 511. Heterogeneity was also observed for the serine beta-lactamases: 14 isolates elaborated serine beta-lactamase activity which focused with major bands with at least eight different pIs. The remaining three strains produced serine beta-lactamases which focused with five distinct bands with pIs of 6.4, 6.2, 5.7, 5.5, and 5.2. We conclude that X. maltophilia produces many types of metallo- and serine beta-lactamases distinguishable by these new methods and that the previously reported L-1 and L-2 enzymes are not solely representative of the beta-lactamases produced by this species. PMID:8067782

  19. Marinobacter halophilus sp. nov., a halophilic bacterium isolated from a salt lake.

    PubMed

    Zhong, Zhi-Ping; Liu, Ying; Liu, Hong-Can; Wang, Fang; Zhou, Yu-Guang; Liu, Zhi-Pei

    2015-09-01

    A Gram-staining-negative bacterium, strain XCD-X12(T), was isolated from Xiaochaidan Lake, a salt lake (salinity 9.9%, w/w) in Qaidam basin, Qinghai Province, China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain XCD-X12(T) were non-spore-forming rods, 0.4-0.7 μm wide, 2.1-3.2 μm long and motile with a single polar flagellum. Strain XCD-X12(T) was strictly aerobic and catalase- and oxidase-positive. Growth was observed in the presence of 0-20.0% (w/v) NaCl (optimum, 4.0-8.0%), at 4-35 °C (optimum, 30 °C) and at pH 6.5-10.5 (optimum, pH 8.5). It contained Q-9 as the predominant respiratory quinone. The major fatty acids (>10.0%) were C16 : 0, C16 : 1ω9c and C18 : 1ω9c. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two unknown phospholipids and an uncharacterized aminophospholipid. The DNA G+C content was 55.6 mol% (Tm). Phylogenetic trees based on 16S rRNA gene sequences showed that strain XCD-X12(T) was associated with the genus Marinobacter, and showed the highest 16S rRNA gene sequence similarity to Marinobacter hydrocarbonoclasticus ATCC 49840(T) (97.4%), M. vinifirmus FB1(T) (96.8%), M. excellens KMM 3809(T) (96.8%) and M. antarcticus ZS2-30(T) (96.7%). DNA-DNA relatedness of strain XCD-X12(T) to M. hydrocarbonoclasticus CGMCC 1.7683(T) was 34 ± 5%. Based on these data, it is concluded that strain XCD-X12(T) represents a novel species of the genus Marinobacter, for which the name Marinobacter halophilus sp. nov. is proposed. The type strain is XCD-X12(T) ( = CGMCC 1.12481(T)= JCM 30472(T)). PMID:25985830

  20. Marinobacter aromaticivorans sp. nov., a polycyclic aromatic hydrocarbon-degrading bacterium isolated from sea sediment.

    PubMed

    Cui, Zhisong; Gao, Wei; Xu, Guangfei; Luan, Xiao; Li, Qian; Yin, Xiaofei; Huang, Deming; Zheng, Li

    2016-01-01

    A rod-shaped, Gram-stain-negative, slightly halotolerant bacterium, designated strain D15-8PT, was isolated from a sediment sample from the South China Sea. The strain could grow in NaCl concentrations ranging from 0.5 % to 10 % (w/v) (optimum 0.5-1.5 %), and could be cultivated at 10-40 °C (optimum 25 °C) and pH 5.5-9.5 (optimum pH 7.0-8.0). The strain was positive for catalase, oxidase, and hydrolysis of Tween 80, but negative for hydrolysis of DNA and gelatin, nitrite reduction, indole production, Voges-Proskauer reaction, and methyl red test. Strain D15-8PT could biodegrade naphthalene, phenanthrene, and anthracene. The major respiratory quinone was Q-9. The main cellular fatty acids were C12 : 0 (11.5 %), C14 : 0 3-methyl (22.0 %), C16 : 0 (19.2 %), C16 : 1ω9c (22.9 %), and C18 : 1ω9c (6.7 %). The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminophospholipid and an unidentified phospholipid. The DNA G+C content was 56.8 mol%. Phylogenetic analyses based on 16S rRNA genes showed that strain D15-8PT was most closely related to Marinobacter maritimus JCM 12521T (98.5 % 16S rRNA gene sequence similarity), Marinobacter antarcticus CGMCC 1.10835T (98.1 %), Marinobacter lipolyticus DSM 15157T (97.1 %), and Marinobacter guineae CECT 7243T (97.0 %). Results of the gyrB gene analysis and DNA-DNA hybridization were both less than the cut-off values (90 % for gyrB gene sequence similarity and 70 % for DNA-DNA hybridization). On the basis of this taxonomic study using a polyphasic approach, strain D15-8PT represents a novel species of the genus Marinobacter, for which the name Marinobacter aromaticivorans sp. nov. is proposed. The type strain is D15-8PT ( = CGMCC 1.11015T = KCTC 23781T). PMID:26518711

  1. Bacillus lindianensis sp. nov., a novel alkaliphilic and moderately halotolerant bacterium isolated from saline and alkaline soils.

    PubMed

    Dou, Guiming; Liu, Hongcan; He, Wei; Ma, Yuchao

    2016-01-01

    Two alkaliphilic and halotolerant Gram-stain positive, rod-shaped and endospore-forming bacteria, designated strains 12-3(T) and 12-4, were isolated from saline and alkaline soils collected in Lindian county, Heilongjiang province, China. Both strains were observed to grow well at a wide range of temperature and pH values, 10-45 °C and pH 8-12, with optimal growth at 37 °C and pH 9.0, respectively. Growth of the two strains was found to occur at total salt concentrations of 0-12 % (w/v), with an optimum at 4 % (w/v). The G+C contents of the genomic DNA of strains 12-3(T) and 12-4 were determined to be 42.7 and 42.4 mol%, respectively, and the major cellular fatty acids were identified as anteiso-C15:0 and anteiso-C17:0. In isolate 12-3(T), meso-diaminopimelic acid was found to be the diagnostic diamino acid of the cell wall peptidoglycan; diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol were identified as the major cellular polar lipids; and menaquinone-7 was identified as the predominant isoprenoid quinone. Strains 12-3(T) and 12-4 share very close 16S rRNA gene sequence similarity (99.74 %) and their DNA-DNA relatedness was 95.3 ± 0.63 %, meaning that the two strains can be considered to belong to the same species. 16S rRNA gene sequence-based phylogenetic analysis revealed strains 12-3(T) and 12-4 exhibit high similarities to Bacillus pseudofirmus DSM 8715(T) (98.7 %), Bacillus marmarensis DSM 21297(T) (97.2 %) and Bacillus nanhaiisediminis CGMCC 1.10116(T) (97.1 and 97.0 %, respectively). DNA-DNA hybridization values between isolate 12-3(T) and the type strains of closely related Bacillus species were below 30 %. On the basis of the polyphasic evidence presented, strains 12-3(T) and 12-4 are considered to represent a novel species of the genus Bacillus, for which the name Bacillus lindianensis sp. nov. is proposed. The type strain is 12-3(T) (DSM 26864(T) = CGMCC 1.12717(T)). PMID:26604103

  2. Halomonas urumqiensis sp. nov., a moderately halophilic bacterium isolated from a saline-alkaline lake.

    PubMed

    Zhang, Shanshan; Pan, Jiao; Lu, Weidong; Yan, Yanchun; Wang, Haisheng; Wiegel, Jurgen; Zhao, Baisuo

    2016-05-01

    A moderately halophilic, aerobic bacterium, strain BZ-SZ-XJ27T, belonging to the genus Halomonas, was isolated from a saline-alkaline lake in the Xinjiang Uyghur Autonomous Region of China. Phylogenetic analysis based on 16S rRNA gene sequences and a multilocus sequence analysis using the 16S rRNA, gyrB and rpoD genes demonstrated that strain BZ-SZ-XJ27T represents a member of the genus Halomonas. On the basis of 16S rRNA gene sequence similarity, the closest relatives were Halomonas campaniensis 5AGT, H. fontilapidosi 5CRT, H. korlensis XK1T and H. sinaiensis ALO SharmT, with similarities of 96.2-97.2 %. DNA-DNA hybridization with H. korlensis CGMCC 1.6981T (the nearest phylogenetic neighbour) and H. campaniensis DSM 15293T (the highest 16S rRNA gene sequence similarity) showed relatedness values of 53 and 38 %, respectively, demonstrating the separateness of the three taxa. The bacterium stained Gram-negative and the cells were motile and rod-shaped. The strain formed creamy-white colonies and grew under optimal conditions of 1.42 M Na+ (range 0.22-4.32 M Na+), pH 8.0-8.5 (range pH 6.0-10.0) and 39 °C (range 4-43 °C). The dominant fatty acids were summed feature 8 (C18 : 1ω7c/C18 : 1ω6c; 36.6 %), C16 : 0 (25.9 %) and summed feature 3 (C16 : 1ω7c/C16 : 1ω6c; 21.2 %). The dominant polar lipids were two unknown phospholipids, phosphatidylethanolamine and phosphatidylglycerol, and the main respiratory quinones were ubiquinone 9 (Q-9; 89 %) and ubiquinone 8 (Q-8; 10 %). The genomic DNA G+C content was 61.7 ± 0.8 mol% (Tm). On the basis of phenotypic, chemotaxonomic and phylogenetic features, strain BZ-SZ-XJ27T is proposed to represent a novel species, Halomonas urumqiensis sp. nov., within the genus Halomonas of the family Halomonadaceae. The type strain is BZ-SZ-XJ27T ( = JCM 30202T = CGMCC 1.12917T). PMID:26873696

  3. Vibrio salilacus sp. nov., a new member of the Anguillarum clade with six alleles of the 16S rRNA gene from a saline lake.

    PubMed

    Zhong, Zhi-Ping; Liu, Ying; Liu, Hong-Can; Wang, Fang; Zhou, Yu-Guang; Liu, Zhi-Pei

    2015-08-01

    A Gram-stain-negative, catalase- and oxidase-positive, facultatively aerobic bacterium, strain DSG-S6T, was isolated from Dasugan Lake (salinity 3.1%, w/w), China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain DSG-S6T were non-spore-forming, slightly bent rods, and motile by means of a single polar flagellum. Growth occurred in the presence of 0-7.0% (w/v) NaCl (optimum, 2.0%), at 4-35 °C (optimum, 30 °C) and at pH 6.0-10.5 (optimum, pH 8.0-8.5). C16 : 0, C18 : 1ω7c and C16 : 1ω7c and/or C16 : 1ω6c were the major fatty acids. Six alleles of the 16S rRNA gene sharing 98.9-99.9  % similarity were detected in strain DSG-S6T, which showed highest 16S rRNA gene sequence similarity to Vibrio aestuarianus ATCC 35048T (97.7 %), then to Vibrio pacinii LMG 19999T (97.6%) and Vibrio metschnikovii CIP 69.14T (96.8%). Multilocus sequence analysis of four housekeeping genes and 16S rRNA genes clearly clustered it as a member of the Anguillarum clade. Mean DNA-DNA relatedness between strain DSG-S6T and V. aestuarianus NBRC 15629T, V. pacinii CGMCC 1.12557T and V. metschnikovii JCM 21189T was 20.6 ± 2.3, 38.1 ± 3.5 and 24.2 ± 2.8%, respectively. The DNA G+C content was 46.8 mol% (Tm). Based on the data, it is concluded that strain DSG-S6T represents a novel species of the genus Vibrio, for which the name Vibrio salilacus sp. nov. is proposed. The type strain is DSG-S6T ( = CGMCC 1.12427T = JCM 19265T). PMID:25964518

  4. Psychroflexus salis sp. nov. and Psychroflexus planctonicus sp. nov., isolated from a salt lake.

    PubMed

    Zhong, Zhi-Ping; Liu, Ying; Wang, Fang; Zhou, Yu-Guang; Liu, Hong-Can; Liu, Zhi-Pei

    2016-01-01

    Two Gram-stain-negative, catalase- and oxidase-positive, strictly aerobic, non-motile, moderately halophilic bacteria (strains X15M-6T and X15M-8T) were isolated from Lake Xiaochaidan, a salt lake in Qaidam basin, Qinghai Province, China. Cells of X15M-6T were rod-like or coccoid, 0.5-0.9 μm wide and 0.9-1.5 μm long; cells of X15M-8T were rods, 0.3-0.6 μm wide and 1.2-2.2 μm long. Growth was observed in the presence of 0.5-14.0 % (w/v) NaCl (optimum, 3.0 %) and at pH 6.5-10.0 (optimum, pH 7.0-7.5) for both. X15M-6T and X15M-8T grew at 10-35 °C (optimum, 20-25 °C) and 4-35 °C (optimum, 25 °C), respectively. Both contained iso-C15 : 0, anteiso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids, phosphatidylethanolamine and an unknown lipid as the major polar lipids, and menaquinone MK-6 as the major respiratory quinone. The DNA G+C contents were 32.8 and 35.0 mol% for X15M-6T and X15M-8T, respectively. Phylogenetic trees based on 16S rRNA gene sequences showed that both strains belonged to the genus Psychroflexus and formed a separate lineage. In addition, strains X15M-6T and X15M-8T shared 96.8 % 16S rRNA gene sequence similarity and showed highest similarities to members of the genus Psychroflexus (92.7-93.5 and 91.8-93.1 %, respectively). Based on the above data, it is concluded that strains X15M-6T and X15M-8T represent two novel species of the genus Psychroflexus, for which the names Psychroflexus salis sp. nov. (type strain X15M-6T = CGMCC 1.12925T = JCM 30615T) and Psychroflexus planctonicus sp. nov. (type strain X15M-8T = CGMCC 1.12931T = JCM 30616T) are proposed. PMID:26475261

  5. Shewanella psychrophila sp. nov. and Shewanella piezotolerans sp. nov., isolated from west Pacific deep-sea sediment.

    PubMed

    Xiao, Xiang; Wang, Peng; Zeng, Xiang; Bartlett, Douglas Hoyt; Wang, Fengping

    2007-01-01

    Two Shewanella-like bacterial strains, WP2(T) and WP3(T), which were isolated from west Pacific deep-sea sediment, were studied to determine their taxonomic position. Cells of the two bacteria were facultatively anaerobic, Gram-negative rods and motile by means of a single polar flagellum. Strain WP2(T) was psychrophilic, growing optimally at about 10-15 degrees C, whereas strain WP3(T) was psychrotolerant, growing optimally at 15-20 degrees C. The two strains grew in the pressure range 0.1-50 MPa, with optimal growth at 20 MPa. Strain WP3(T) was able to use nitrate, fumarate, trimethylamine N-oxide (TMAO), DMSO and insoluble Fe(III) as terminal electron acceptors during anaerobic growth, whereas strain WP2(T) was able to use only nitrate, TMAO and DMSO. The 16S rRNA gene sequences of strains WP2(T) and WP3(T) were 97 % identical, and showed highest similarity (97 %) to those of Shewanella fidelis KMM 3589 and Shewanella benthica ATCC 43992(T), respectively. The gyrB gene sequences of strains WP2(T)and WP3 (T) were also determined, and showed highest similarity to those of Shewanella violacea JCM 10179(T) (90 %) and Shewanella sairae SM2-1(T) (87 %), respectively. Contrary to the 16S rRNA gene sequence results, the phylogeny based on gyrB gene sequence analysis placed strain WP2(T), S. violacea and S. benthica in one group, while strain WP3(T) grouped with S. fidelis and S. sairae. DNA-DNA hybridization experiments supported the placement of strain WP2(T) with S. violacea and S. benthica. Phylogenetic evidence, together with DNA-DNA relatedness and phenotypic characteristics, indicated that the two new strains represented two novel deep-sea Shewanella species. The names Shewanella psychrophila sp. nov. (type strain WP2(T)=JCM 13876(T)=CGMCC 1.6159(T)) and Shewanella piezotolerans (type strain WP3(T)=JCM 13877(T)=CGMCC 1.6160(T)) are proposed. PMID:17220442

  6. Outer membrane protein D2 catalyzes facilitated diffusion of carbapenems and penems through the outer membrane of Pseudomonas aeruginosa.

    PubMed Central

    Trias, J; Nikaido, H

    1990-01-01

    The outer membrane of imipenem-resistant mutants of Pseudomonas aeruginosa with decreased permeability to imipenem was shown by Western (immuno-) blotting to contain protein D1 and to lack protein D2. Protein D2 was purified and was shown to allow the permeation of imipenem at a rate higher than expected from its molecular weight. Spontaneous imipenem-resistant mutants of P. aeruginosa PAO1 appeared at a frequency of 10(-8) in the laboratory and did not synthesize protein D2. Experiments performed with intact cells carrying plasmid pHN4 containing the gene for L-1 beta-lactamase from Pseudomonas maltophilia showed that this channel could also be used by SM-7338, Sch 33755, and Sch 33440 but apparently not by Sch 34343 or Sch 29482. Images PMID:2109575

  7. Meteorite organics in planetary environments: hydrothermal release, surface activity, and microbial utilization

    NASA Technical Reports Server (NTRS)

    Mautner, M. N.; Leonard, R. L.; Deamer, D. W.

    1995-01-01

    Up to 50% of the organics in the Murchison meteorite, possibly including some of the polymer, is released in high temperature and pressure aqueous environments, to 350 degrees C and 250 bar, that simulate submarine volcanic, hydrothermal or impact-induced conditions. Meteorite organics of prebiotic significance, such as nonanoic acid, glycine, and pyrene survive the hydrothermal conditions. The released material is surface active with surface pressures up to 19.8 x 10(-3) N m-1, and exhibits an extended surface tension isotherm which suggests a mixture of amphiphilic components. One component, nonanoic acid, is shown to form vesicles. The materials extracted under mild conditions, at 120 degrees C, are nutrients for the humic acid bacterium Pseudomonas maltophilia and efficient nutrients for the oligotroph Flavobacterium oryzihabitans, demonstrating the capability of microorganisms to metabolize extraterrestrial organics.

  8. Analysis of the interaction between autochthonous bacteria and packaging material in PVC-bottled mineral water.

    PubMed

    Guerzoni, M E; Lanciotti, R; Sinigaglia, M; Gardini, F

    1994-06-01

    A study with about 10,000 bottles produced by a mineral water company was undertaken in order to identify the causal agent of an off-odour occurrence in the bottled water. Some physiological attributes of the dominant species over an 8-month period, as well as their interaction with packaging material, were investigated. Pseudomonas maltophilia, P. acidovorans, Acinetobacter calcoaceticus var. lowffi, frequently associated with bottles having an off-odour, seemed to play a decisive role in the phenomenon due to their elevated lipolytic activity, their cell hydrophobicity and adhesivity to the PVC walls. Their ability to attack the sodium polysulfide included in the ultramarine blue dye present in PVC, transforming it to H2S was investigated. PMID:7921893

  9. Composition of the microflora of witloof chicory seeds.

    PubMed

    Van Outryve, M F; Gosselé, V; Gosselé, F; Swings, J

    1988-11-01

    The bacterial microflora of nine varieties of witloof chicory (Cichorium intybus L. var.foliosum Hegi) seeds was studied. The 184 isolates were characterized by protein profiles determined by SDS-protein polyacrylamide gel electrophoresis of the total cell proteins. Isolates with identical protein profiles were grouped into one fingerprint type. Sixty-seven fingerprint types were distinguished. Two quantitatively major fingerprint types,Erwinia herbicola and an arthrobacter, represented 52% of the total number of isolates and were found on different chicory varieties. The latter organism was inhibited at seed germination. Other isolates, i.e.,Xanthomonas maltophilia, Pseudomonas paucimobilis, Agrobacterium radiobacter, Pseudomonas syringae, and a fluorescentPseudomonas, were only occasionally found. A minority were gram-positive isolates, i.e.,Bacillus sp.,Streptomyces sp., and coryneforms. In vitro activity of the isolates was tested against five fungi. Isolates with strong antifungal activity were found amongErwinia herbicola andBacillus sp. PMID:24201719

  10. Motion of the zinc ions in catalysis by a dizinc metallo-beta-lactamase.

    PubMed

    Breece, Robert M; Hu, Zhenxin; Bennett, Brian; Crowder, Michael W; Tierney, David L

    2009-08-26

    We report rapid-freeze-quench X-ray absorption spectroscopy of a dizinc metallo-beta-lactamase (MbetaL) reaction intermediate. The Zn(II) ions in the dinuclear active site of the S. maltophilia Class B3 MbetaL move away from each other, by approximately 0.3 A after 10 ms of reaction with nitrocefin, from 3.4 to 3.7 A. Together with our previous characterization of the resting enzyme and its nitrocefin product complex, where the Zn(II) ion separation relaxes to 3.6 A, these data indicate a scissoring motion of the active site that accompanies the ring-opening step. The average Zn(II) coordination number of 4.5 in the resting enzyme appears to be maintained throughout the reaction with nitrocefin. This is the first direct structural information available on early stage dizinc metallo-beta-lactamase catalysis. PMID:19653676

  11. Bacteriocuprein superoxide dismutases in pseudomonads

    SciTech Connect

    Steinman, H.M.

    1985-06-01

    Two new instances of the rare bacteriocuprein form of superoxide dismutase have been discovered in Pseudomonas diminuta and P. maltophilia. Each species contains a manganese superoxide dismutase as well. Eight other strains of Pseudomonas and Xanthomonas spp. lacked bacteriocupreins and contained either a manganese or an iron superoxide dismutase. Native molecular weights and isoelectric points were determined for all these bacterial dismutases. A monospecific polyclonal antibody was prepared against the bacteriocuprein from Photobacterium leiognathi; it was not cross-reactive with the bacteriocuprein from either Pseudomonas strain. Bacteriocupreins have previously been identified in only two procaryotes, P. leiognathi and Caulobacter crescentus. The discovery of the Pseudomonas bacteriocupreins reveals a broader distribution, raising the possibility that bacteriocupreins are a continuous line of descent among procryotes and not isolated evolutionary occurrences, as previous data suggested.

  12. Molecular characterization of nitrogen-fixing bacteria isolated from brazilian agricultural plants at São Paulo state

    PubMed Central

    Reinhardt, Érica. L.; Ramos, Patrícia L.; Manfio, Gilson P.; Barbosa, Heloiza R.; Pavan, Crodowaldo; Moreira-Filho, Carlos A.

    2008-01-01

    Fourteen strains of nitrogen-fixing bacteria were isolated from different agricultural plant species, including cassava, maize and sugarcane, using nitrogen-deprived selective isolation conditions. Ability to fix nitrogen was verified by the acetylene reduction assay. All potentially nitrogen-fixing strains tested showed positive hybridization signals with a nifH probe derived from Azospirillum brasilense. The strains were characterized by RAPD, ARDRA and 16S rDNA sequence analysis. RAPD analyses revealed 8 unique genotypes, the remaining 6 strains clustered into 3 RAPD groups, suggesting a clonal origin. ARDRA and 16S rDNA sequence analyses allowed the assignment of 13 strains to known groups of nitrogen-fixing bacteria, including organisms from the genera Azospirillum, Herbaspirillum, Pseudomonas and Enterobacteriaceae. Two strains were classified as Stenotrophomonas ssp. Molecular identification results from 16S rDNA analyses were also corroborated by morphological and biochemical data. PMID:24031239

  13. Synthesis and structural characterization of Pd(II) complexes derived from perimidine ligand and their in vitro antimicrobial studies

    NASA Astrophysics Data System (ADS)

    Azam, Mohammad; Warad, Ismail; Al-Resayes, Saud I.; Alzaqri, Nabil; Khan, Mohammad Rizwan; Pallepogu, Raghavaiah; Dwivedi, Sourabh; Musarrat, Javed; Shakir, Mohammad

    2013-09-01

    A novel series of Pd(II) complexes derived from 2-thiophenecarboxaldehyde and 1,8-diaminonaphthalene has been synthesized and characterized by various physico-chemical and spectroscopic techniques viz., elemental analyses, IR, UV-vis, 1H and 13C NMR spectroscopy, and ESI-mass spectrometry. The structure of ligand, 2-(2-thienyl)-2,3-dihydro-1H-perimidine has been ascertained on the basis of single crystal X-ray diffraction. All Pd(II) complexes together with the corresponding ligand have been evaluated for their ability to suppress the in vitro growth of microbes, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Citrobacter sp., Bacillus subtilis and Stenotrophomonas acidaminiphila and results show that Pd(II) complexes have more significant antimicrobial activity than their corresponding ligand. Fluorescence spectroscopic measurements clearly support that both of the Pd(II) complexes show significant DNA binding with calf thymus DNA.

  14. Bacteria associated with orchid roots and microbial production of auxin.

    PubMed

    Tsavkelova, Elena A; Cherdyntseva, Tatiana A; Botina, Svetlana G; Netrusov, Alexander I

    2007-01-01

    Associative bacteria of terrestrial (Paphiopedilum appletonianum) and epiphytic (Pholidota articulata) tropical orchids were investigated. Microbial community of epiphytic plant differed from that of the terrestrial one. Streptomyces, Bacillus, Pseudomonas, Burkholderia, Erwinia and Nocardia strains populated Paphiopedilum roots, whereas Pseudomonas, Flavobacterium, Stenotrophomonas, Pantoea, Chryseobacterium, Bacillus, Agrobacterium, Erwinia, Burkholderia and Paracoccus strains colonized Pholidota roots. Endophytic bacteria populations were represented with less diversity: Streptomyces, Bacillus, Erwinia and Pseudomonas genera were isolated from P. appletonianum, and Pseudomonas, Bacillus, and Flavobacterium genera were isolated from Ph. articulata. Microorganisms produced indole-3-acetic acid (IAA). Variations in its biosynthesis among the strains of the same genus were also observed. The highest auxin level was detected during the stationary growth phase. Biological activity of microbial IAA was proved by treatment of kidney bean cuttings with bacterial supernatants, revealing considerable stimulation of root formation and growth. PMID:17140781

  15. Best conditions for biodegradation of diesel oil by chemometric tools

    PubMed Central

    Kaczorek, Ewa; Bielicka-Daszkiewicz, Katarzyna; Héberger, Károly; Kemény, Sándor; Olszanowski, Andrzej; Voelkel, Adam

    2014-01-01

    Diesel oil biodegradation by different bacteria-yeast-rhamnolipids consortia was tested. Chromatographic analysis of post-biodegradation residue was completed with chemometric tools (ANOVA, and a novel ranking procedure based on the sum of ranking differences). These tools were used in the selection of the most effective systems. The best results of aliphatic fractions of diesel oil biodegradation were observed for a yeast consortia with Aeromonas hydrophila KR4. For these systems the positive effect of rhamnolipids on hydrocarbon biodegradation was observed. However, rhamnolipids addition did not always have a positive influence on the biodegradation process (e.g. in case of yeast consortia with Stenotrophomonas maltophila KR7). Moreover, particular differences in the degradation pattern were observed for lower and higher alkanes than in the case with C22. Normally, the best conditions for “lower” alkanes are Aeromonas hydrophila KR4 + emulsifier independently from yeasts and e.g. Pseudomonas stutzeri KR7 for C24 alkane. PMID:24948922

  16. Optimization of a bacterial consortium for nitrobenzene degradation.

    PubMed

    Jin, D F; Hu, H; Liu, D F; Ding, H T; Jia, X M; Zhao, Y H

    2012-01-01

    Three bacterial strains, Arthrobacter sp. NB1, Serratia sp. NB2 and Stenotrophomonas sp. NB3, were isolated from contaminated sludge by using nitrobenzene as a sole source of carbon and nitrogen. It was observed that all three strains could degrade nitrobenzene at 400 mg/L initial concentration and mixed-cultivation of these strains could enhance the degradation of nitrobenzene compared with mono-cultivation. Mixture design was used for adjusting the proportions of each strain and the optimal ratio of inoculation size was NB1:NB2:NB3 = 4:4:5, where the nitrobenzene degradation percentage was two times higher than for by the single strain. The results of Plackett-Burman design indicated that Mg(2+), Ca(2+), Fe(2+), Zn(2+) and Mn(2+) had a positive effect on the degradation of nitrobenzene, while Cu(2+) and Co(2+) had a negative effect on it. PMID:22339012

  17. Biodegradation of antibiotic ciprofloxacin: pathways, influential factors, and bacterial community structure.

    PubMed

    Liao, Xiaobin; Li, Bingxin; Zou, Rusen; Dai, Yu; Xie, Shuguang; Yuan, Baoling

    2016-04-01

    Antibiotic ciprofloxacin is ubiquitous in the environment. However, little is known about ciprofloxacin dissipation by microbial community. The present study investigated the biodegradation potential of ciprofloxacin by mixed culture and the influential factors and depicted the structure of ciprofloxacin-degrading microbial community. Both the original microbiota from drinking water biofilter and the microbiota previously acclimated to high levels of ciprofloxacin could utilize ciprofloxacin as sole carbon and nitrogen sources, while the acclimated microbiota had a much stronger removal capacity. Temperature rise and the presence of carbon or nitrogen sources favored ciprofloxacin biodegradation. Many novel biotransformation products were identified, and four different metabolic pathways for ciprofloxacin were proposed. Bacterial community structure illustrated a profound shift with ciprofloxacin biodegradation. The ciprofloxacin-degrading bacterial community was mainly composed of classes Gammaproteobacteria, Bacteroidia, and Betaproteobacteria. Microorganisms from genera Pseudoxanthomonas, Stenotrophomonas, Phenylobacterium, and Leucobacter might have links with the dissipation of ciprofloxacin. This work can provide some new insights towards ciprofloxacin biodegradation. PMID:26762935

  18. Identification and analysis of polyaromatic hydrocarbons (PAHs)--biodegrading bacterial strains from refinery soil of India.

    PubMed

    Chaudhary, Priyanka; Sahay, Harmesh; Sharma, Richa; Pandey, Alok Kumar; Singh, Shashi Bala; Saxena, A K; Nain, Lata

    2015-06-01

    Polyaromatic hydrocarbons (PAHs) utilizing bacteria were isolated from soils of seven sites of Mathura refinery, India. Twenty-six bacterial strains with different morphotypes were isolated. These strains were acclimatized to utilize a mixture of four polycyclic aromatic hydrocarbons, i.e., anthracene, fluorene, phenanthrene, and pyrene, each at 50 mg/L concentration as sole carbon source. Out of total isolates, 15 potent isolates were subjected to 16S rDNA sequencing and identified as a member of diverse genera, i.e., Bacillus, Acinetobacter, Stenotrophomonas, Alcaligenes, Lysinibacillus, Brevibacterium, Serratia, and Streptomyces. Consortium of four promising isolates (Acinetobacter, Brevibacterium, Serratia, and Streptomyces) were also investigated for bioremediation of PAH mixture. This consortium was proved to be efficient PAH degrader resulting in 40-70 % degradation of PAH within 7 days. Results of this study indicated that these genera may play an active role in bioremediation of PAHs. PMID:26026847

  19. Community structure analysis of reverse osmosis membrane biofilms and the significance of Rhizobiales bacteria in biofouling.

    PubMed

    Pang, Chee Meng; Liu, Wen-Tso

    2007-07-01

    The biofilm community structure of a biofouled reverse osmosis (RO) membrane was examined using a polyphasic approach, and the dominant phylotypes retrieved were related to the order Rhizobiales, a group of bacteria that is hitherto not implicated in membrane biofouling. A comparison with two other membrane biofilms using T-RFLP fingerprinting also revealed the dominance of Rhizobiales organisms. When pure culture RO biofilm isolates were cultivated aerobically in BIOLOG microplates, most Rhizobiales were metabolically versatile in their choice of carbon substrates. Nitrate reduction was observed in five RO isolates related to Castellaniella, Ochrobactrum, Stenotrophomonas, and Xanthobacter. Many of the key Rhizobiales genera including Bosea, Ochrobactrum, Shinella, and Rhodopseudomonas were detected by PCR to contain the nirK gene responsible for nitrite reductase activity. These findings suggest that Rhizobiales organisms are ecologically significant in membrane biofilm communities under both aerobic and anoxic conditions and may be responsible for biofouling in membrane separation systems. PMID:17695921

  20. Characterization of bacterial communities in hybrid upflow anaerobic sludge blanket (UASB)-membrane bioreactor (MBR) process for berberine antibiotic wastewater treatment.

    PubMed

    Qiu, Guanglei; Song, Yong-Hui; Zeng, Ping; Duan, Liang; Xiao, Shuhu

    2013-08-01

    Biodegradation of berberine antibiotic was investigated in upflow anaerobic sludge blanket (UASB)-membrane bioreactor (MBR) process. After 118days of operation, 99.0%, 98.0% and 98.0% overall removals of berberine, COD and NH4(+)-N were achieved, respectively. The detailed composition of the established bacterial communities was studied by using 16S rDNA clone library. Totally, 400 clones were retrieved and grouped into 186 operational taxonomic units (OTUs). UASB was dominated by Firmicutes and Bacteroidetes, while Proteobacteria, especially Alpha- and Beta-proteobacteria were prevalent in the MBRs. Clostridium, Eubacterium and Synergistes in the UASB, as well as Hydrogenophaga, Azoarcus, Sphingomonas, Stenotrophomonas, Shinella and Alcaligenes in the MBRs were identified as potential functional species in biodegradation of berberine and/or its metabolites. The bacterial community compositions in two MBRs were significantly discrepant. However, the identical functions of the functional species ensured the comparable pollutant removal performances in two bioreactors. PMID:23735790

  1. ESTIMATING BACTERIAL DIVERSITY IN SCIRTOTHRIPS DORSALIS (THYSANOPTERA: THRIPIDAE) VIA NEXT GENERATION SEQUENCING.

    PubMed

    Dickey, Aaron M; Trease, Andrew J; Jara-Cavieres, Antonella; Kumar, Vivek; Christenson, Matthew K; Potluri, Lakshmi-Prasad; Morgan, J Kent; Shatters, Robert G; Mckenzie, Cindy L; Davis, Paul H; Osborne, Lance S

    2014-06-01

    The last 2 decades have produced a better understanding of insect-microbial associations and yielded some important opportunities for insect control. However, most of our knowledge comes from model systems. Thrips (Thysanoptera: Thripidae) have been understudied despite their global importance as invasive species, plant pests and disease vectors. Using a culture and primer independent next-generation sequencing and metagenomics pipeline, we surveyed the bacteria of the globally important pest, Scirtothrips dorsalis Hood. The most abundant bacterial phyla identified were Actinobacteria and Proteobacteria and the most abundant genera were Propionibacterium, Stenotrophomonas, and Pseudomonas. A total of 189 genera of bacteria were identified. The absence of any vertically transferred symbiont taxa commonly found in insects is consistent with other studies suggesting that thrips primarilly acquire resident microbes from their environment. This does not preclude a possible beneficial/intimate association between S. dorsalis and the dominant taxa identified and future work should determine the nature of these associations. PMID:25382863

  2. Best conditions for biodegradation of diesel oil by chemometric tools.

    PubMed

    Kaczorek, Ewa; Bielicka-Daszkiewicz, Katarzyna; Héberger, Károly; Kemény, Sándor; Olszanowski, Andrzej; Voelkel, Adam

    2014-01-01

    Diesel oil biodegradation by different bacteria-yeast-rhamnolipids consortia was tested. Chromatographic analysis of post-biodegradation residue was completed with chemometric tools (ANOVA, and a novel ranking procedure based on the sum of ranking differences). These tools were used in the selection of the most effective systems. The best results of aliphatic fractions of diesel oil biodegradation were observed for a yeast consortia with Aeromonas hydrophila KR4. For these systems the positive effect of rhamnolipids on hydrocarbon biodegradation was observed. However, rhamnolipids addition did not always have a positive influence on the biodegradation process (e.g. in case of yeast consortia with Stenotrophomonas maltophila KR7). Moreover, particular differences in the degradation pattern were observed for lower and higher alkanes than in the case with C22. Normally, the best conditions for "lower" alkanes are Aeromonas hydrophila KR4 + emulsifier independently from yeasts and e.g. Pseudomonas stutzeri KR7 for C24 alkane. PMID:24948922

  3. Molecular characterization of nitrogen-fixing bacteria isolated from brazilian agricultural plants at São Paulo state.

    PubMed

    Reinhardt, Erica L; Ramos, Patrícia L; Manfio, Gilson P; Barbosa, Heloiza R; Pavan, Crodowaldo; Moreira-Filho, Carlos A

    2008-07-01

    Fourteen strains of nitrogen-fixing bacteria were isolated from different agricultural plant species, including cassava, maize and sugarcane, using nitrogen-deprived selective isolation conditions. Ability to fix nitrogen was verified by the acetylene reduction assay. All potentially nitrogen-fixing strains tested showed positive hybridization signals with a nifH probe derived from Azospirillum brasilense. The strains were characterized by RAPD, ARDRA and 16S rDNA sequence analysis. RAPD analyses revealed 8 unique genotypes, the remaining 6 strains clustered into 3 RAPD groups, suggesting a clonal origin. ARDRA and 16S rDNA sequence analyses allowed the assignment of 13 strains to known groups of nitrogen-fixing bacteria, including organisms from the genera Azospirillum, Herbaspirillum, Pseudomonas and Enterobacteriaceae. Two strains were classified as Stenotrophomonas ssp. Molecular identification results from 16S rDNA analyses were also corroborated by morphological and biochemical data. PMID:24031239

  4. ESTIMATING BACTERIAL DIVERSITY IN SCIRTOTHRIPS DORSALIS (THYSANOPTERA: THRIPIDAE) VIA NEXT GENERATION SEQUENCING

    PubMed Central

    Dickey, Aaron M.; Trease, Andrew J.; Jara-Cavieres, Antonella; Kumar, Vivek; Christenson, Matthew K.; Potluri, Lakshmi-Prasad; Morgan, J. Kent; Shatters, Robert G.; Mckenzie, Cindy L.; Davis, Paul H.; Osborne, Lance S.

    2014-01-01

    The last 2 decades have produced a better understanding of insect-microbial associations and yielded some important opportunities for insect control. However, most of our knowledge comes from model systems. Thrips (Thysanoptera: Thripidae) have been understudied despite their global importance as invasive species, plant pests and disease vectors. Using a culture and primer independent next-generation sequencing and metagenomics pipeline, we surveyed the bacteria of the globally important pest, Scirtothrips dorsalis Hood. The most abundant bacterial phyla identified were Actinobacteria and Proteobacteria and the most abundant genera were Propionibacterium, Stenotrophomonas, and Pseudomonas. A total of 189 genera of bacteria were identified. The absence of any vertically transferred symbiont taxa commonly found in insects is consistent with other studies suggesting that thrips primarilly acquire resident microbes from their environment. This does not preclude a possible beneficial/intimate association between S. dorsalis and the dominant taxa identified and future work should determine the nature of these associations. PMID:25382863

  5. Complete genome sequence of the heavy metal resistant bacterium Altererythrobacter atlanticus 26DY36(T), isolated from deep-sea sediment of the North Atlantic Mid-ocean ridge.

    PubMed

    Wu, Yue-Hong; Cheng, Hong; Zhou, Peng; Huo, Ying-Yi; Wang, Chun-Sheng; Xu, Xue-Wei

    2015-12-01

    Altererythrobacter atlanticus 26DY36(T) (CGMCC 1.12411(T)=JCM 18865(T)) was isolated from the North Atlantic Mid-Ocean Ridge. The strain is resistant to heavy metals, such as Mn(2+) (200 mM), Co(2+) (2.0mM), Cu(2+) (1mM), Zn(2+) (1mM), Hg(2+) (0.1mM) and Cd(2+) (0.5mM). Here we describe the genome sequence and annotation, as well as the features of the organism. A. atlanticus 26DY36(T) harbors a chromosome (3,386,291 bp) and a circular plasmid (88,815 bp). The genome contains 3322 protein-coding genes (2483 with predicted functions), 47 tRNA genes and 6 rRNA genes. A. atlanticus 26DY36(T) encodes dozens of genes related to heavy metal resistance and has potential applications in the bioremediation of heavy metal-contaminated environments. PMID:26508671

  6. Saccharothrix carnea sp. nov., an actinobacterium isolated from soil.

    PubMed

    Liu, Chongxi; Guan, Xuejiao; Wang, Shurui; Zhao, Junwei; Wang, Haiyan; He, Hairong; Xiang, Wensheng; Wang, Xiangjing

    2014-12-01

    A novel actinobacterium, designated strain NEAU-yn17(T), was isolated from a soil sample collected at the wastewater discharge site of a pesticide factory in Harbin, northern China, and characterized using a polyphasic approach. Morphological and chemotaxonomic properties of strain NEAU-yn17(T) were consistent with the description of the genus Saccharothrix, such as the spore arrangement, the diamino acid of the peptidoglycan, the whole-cell hydrolysates, the predominant menaquinone and the phospholipid profile. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that strain NEAU-yn17(T) should also be classified in the genus Saccharothrix, with Saccharothrix saharensis DSM 45456(T) (99.52 % sequence similarity) and Saccharothrix xinjiangensis JCM 12329(T) (99.04 %) as the nearest phylogenetic relatives. A combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-yn17(T) can be distinguished from its closest relatives. Therefore, strain NEAU-yn17(T) represents a novel species of the genus Saccharothrix, for which the name Saccharothrix carnea sp. nov. is proposed. The type strain is NEAU-yn17(T) ( = CGMCC 4.7097(T) = DSM 45878(T)). PMID:25256705

  7. Actinomadura gamaensis sp. nov., a novel actinomycete isolated from soil in Gama, Chad.

    PubMed

    Abagana, Adam Yacoub; Sun, Pengyu; Liu, Chongxi; Cao, Tingting; Zheng, Weiwei; Zhao, Shanshan; Xiang, Wensheng; Wang, Xiangjing

    2016-06-01

    A novel single spore-producing actinomycete, designated strain NEAU-Gz5(T), was isolated from a soil sample from Gama, Chad. A polyphasic taxonomic study was carried out to establish the status of this strain. The diamino acid present in the cell wall is meso-diaminopimelic acid. Glucose, mannose and madurose occur in whole cell hydrolysates. The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside and an unidentified glycolipid. The predominant menaquinones were identified as MK-9(H8) and MK-9(H6). The predominant cellular fatty acids were found to be C16:0, iso-C15:0, iso-C16:0 and C18:0 10-methyl. Phylogenetic analysis based on the 16S rRNA gene showed that strain NEAU-Gz5(T) belongs to the genus Actinomadura and is closely related to Actinomadura oligospora JCM 10648(T) (ATCC 43269(T); 98.3 % similarity). However, the low level of DNA-DNA relatedness and some different phenotypic characteristics allowed the strain to be distinguished from its close relatives. Therefore, it is concluded that strain NEAU-Gz5(T) represents a novel species of the genus of Actinomadura, for which the name Actinomadura gamaensis sp. nov. is proposed. The type strain is NEAU-Gz5(T) (= CGMCC 4.7301(T) = DSM 100815(T)). PMID:27010208

  8. Enhanced deacidification activity in Schizosaccharomyces pombe by genome shuffling.

    PubMed

    Ding, Su; Zhang, Ying; Zhang, Jing; Zeng, Wei; Yang, Ying; Guan, Jingxi; Pan, Lixia; Li, Wei

    2015-02-01

    A problem frequently occurring in making some kinds of wines, particularly Vitis quinquangularis Rehd wine, is the presence of malic acid at high concentrations, which is detrimental to the quality of wines. Thus, there is a need of the ways for effectively reducing the malic acid levels in wine. This study aimed to generate shuffled fusants of Schizosaccharomyces pombe with enhanced deacidification activity for reducing the excessive malic acid content in wine. Sz. pombe CGMCC 2.1628 was used as the original strain. The starting mutant population was generated by UV treatment. The mutants with higher deacidification activity were selected and subjected to recursive protoplast fusion. The resulting fusants were screened by using the indicator of malic acid concentration of fermentation supernatants on 96-well microtitre plates, measured with bromocresol green. After three rounds of genome shuffling, the best-performing fusant, named GS3-1, was obtained. Its deacidification activity (consumed 4.78 g/l malic acid within 10 days) was increased by 225.2% as compared to that of original strain. In the Vitis quinquangularis Rehd wine fermentation test, GS3-1 consumed 4.0 g/l malic acid during the whole cycle of fermentation, providing up to 185.7% improvement in malic acid consumption compared with that of the original strain. This study shows that GS3-1 has great potential for improving the quality of Vitis quinquangularis Rehd wine. PMID:25377082

  9. Glycerol/Glucose Co-Fermentation: One More Proficient Process to Produce Propionic Acid by Propionibacterium acidipropionici

    PubMed Central

    Liu, Yin; Zhang, Yong-Guang; Zhang, Ru-Bing; Zhang, Fan

    2010-01-01

    Cosubstrates fermentation is such an effective strategy for increasing subject metabolic products that it could be available and studied in propionic acid production, using glycerol and glucose as carbon resources. The effects of glycerol, glucose, and their mixtures on the propionic acid production by Propionibacterium acidipropionici CGMCC1.2225 (ATCC4965) were studied, with the aim of improving the efficiency of propionic acid production. The propionic acid yield from substrate was improved from 0.475 and 0.303 g g−1 with glycerol and glucose alone, respectively, to 0.572 g g−1 with co-fermentation of a glycerol/glucose mixture of 4/1 (mol/mol). The maximal propionic acid and substrate conversion rate were 21.9 g l−1 and 57.2% (w/w), respectively, both significantly higher than for a sole carbon source. Under optimized conditions of fed-batch fermentation, the maximal propionic acid yield and substrate conversion efficiency were 29.2 g l−1 and 54.4% (w/w), respectively. These results showed that glycerol/glucose co-fermentation could serve as an excellent alternative to conventional propionic acid fermentation. PMID:20544200

  10. Methanoculleus hydrogenitrophicus sp. nov., a methanogenic archaeon isolated from wetland soil.

    PubMed

    Tian, Jianqing; Wang, Yanfen; Dong, Xiuzhu

    2010-09-01

    An obligately anaerobic, methanogenic archaeon, strain HC(T), was isolated from soil of the Zoige wetland on the Tibetan plateau, China. The strain was isolated through construction of an artificial butyrate-degrading consortium in co-culture with a syntrophic bacterium, 'Syntrophomonas erecta subsp. sporosyntropha' JCM 13344. Cells of strain HC(T) were irregular coccoids, 0.8-2 mum in diameter, that occurred singly and utilized only H(2)/CO(2) for growth and methane production. Growth occurred at 18-45 degrees C (optimum around 37 degrees C). The pH for growth was 5.0-8.5 (optimal growth around pH 6.6). The G+C content of the genomic DNA was 60.2 mol%. 16S rRNA gene sequence analysis indicated that strain HC(T) was affiliated to the genus Methanoculleus, with sequence similarities of 94.8-97.2 % to existing members. However, strain HC(T) was distinguished from described Methanoculleus species by not using formate for growth or methane formation and not requiring acetate as a growth factor. On the basis of phylogenetic analysis and phenotypic characteristics, the novel species Methanoculleus hydrogenitrophicus sp. nov. is proposed, with strain HC(T) (=CGMCC 1.5146(T) =JCM 16311(T)) as the type strain. PMID:19897615

  11. Pacificimonas aurantium sp. nov., Isolated from the Seawater of the Pacific Ocean.

    PubMed

    Li, Shuhui; Zhou, Wenchu; Lin, Dan; Tang, Kai; Jiao, Nianzhi

    2016-06-01

    A Gram-negative bacterium, denoted JLT2012(T), was isolated from the surface water of the Pacific Ocean. This aerobic bacterium was rod shaped and devoid of flagella, displayed gliding motility, and grew in characteristic orange colonies. The bacterium contained ubiquinone Q-10 as the major respiratory quinone, and spermidine and spermine as the major polyamine compounds. The dominant fatty acids were C18:1ω7c and/or C18:1ω6c (34.7 %), C16:0 (21.3 %), and C18:0 (15.9 %), whereas the polar lipids consisted mainly of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, four sphingoglycolipids, and several unknown glycolipids. The G + C content DNA was found to be 65.5 mol%. Comparative 16S rRNA gene sequence analysis revealed that strain JLT2012(T) formed a distinct lineage within the genus Pacificimonas (formerly known as Pacificamonas) and shared the highest sequence similarity with the type strain of Pacificimonas flava JLT2015(T) (96.0 %). Data combined from different studies on the phenotypic, phylogenetic, and genomic characteristics indicated that strain JLT2012(T) is a representative of a novel species within Pacificimonas for which the name Pacificimonas aurantium sp. nov. (type strain JLT2012(T)=LMG 27361(T)=CGMCC 1.12399(T)) is proposed. PMID:26920869

  12. Genomic Diversity and Evolution of Bacillus subtilis.

    PubMed

    Yu, Gang; Wang, Xun Cheng; Tian, Wang Hong; Shi, Ji Chun; Wang, Bin; Ye, Qiang; Dong, Si Guo; Zeng, Ming; Wang, Jun Zhi

    2015-08-01

    Bacillus subtilis is the focus of both academic and industrial research. Previous studies have reported a number of sequence variations in different B. subtilis strains. To uncover the genetic variation and evolutionary pressure in B. subtilis strains, we performed whole genome sequencing of two B. subtilis isolates, KM and CGMCC63528. Comparative genomic analyses of these two strains with other B. subtilis strains identified high sequence variations including large insertions, deletions and SNPs. Most SNPs in genes were synonymous and the average frequency of synonymous mutations was significantly higher than that of the non-synonymous mutations. Pan-genome analysis of B. subtilis strains showed that the core genome had lower dN/dS values than the accessory genome. Whole genome comparisons of these two isolates with other B. subtilis strains showed that strains in different subspecies have similar dN/dS values. Nucleotide diversity analysis showed that spizizenii subspecies have higher nucleotide diversity than subtilis subspecies. Our results indicate that genes in B. subtilis strains are under high purifying selection pressure. The evolutionary pressure in different subspecies of B. subtilis is complex. PMID:26383601

  13. Massilia eurypsychrophila sp. nov. a facultatively psychrophilic bacteria isolated from ice core.

    PubMed

    Shen, Liang; Liu, Yongqin; Gu, Zhengquan; Xu, Baiqing; Wang, Ninglian; Jiao, Nianzhi; Liu, Hongcan; Zhou, Yuguang

    2015-07-01

    Strain B528-3(T), a Gram-stain-negative, rod-shaped, aerobic, facultatively psychrophilic bacterium with polar flagella, was isolated from an ice core drilled from Muztagh Glacier, Xinjiang, China. The novel isolate was classified into the genus Massilia. The 16S rRNA gene sequence of the novel isolate shares a pairwise similarity of less than 97% with those of all the type strains of the genus Massilia. The major fatty acids of strain B528-3(T) were summed feature 3 (C16:1ω7c and/or iso-C15:0 2-OH) (57.31%), C16:0 (11.46%) and C18:1ω7c (14.72%). The predominant isoprenoid quinone was Q-8. The DNA G + C content was 62.2 mol% (Tm). The major polar lipids of this bacterium were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. From the genotypic and phenotypic data, it is evident that strain B528-3(T) represents a novel species of the genus Massilia, for which the name Massilia eurypsychrophila sp. nov. is proposed. The type strain is B528-3(T) ( = JCM 30074(T) = CGMCC 1.12828(T)). PMID:25851590

  14. Fulvimarina manganoxydans sp. nov., isolated from a deep-sea hydrothermal plume in the south-west Indian Ocean.

    PubMed

    Ren, Fei; Zhang, Limin; Song, Lei; Xu, Shiyao; Xi, Lijun; Huang, Li; Huang, Ying; Dai, Xin

    2014-08-01

    An aerobic, Mn(II)-oxidizing, Gram-negative bacterium, strain 8047(T), was isolated from a deep-sea hydrothermal vent plume in the south-west Indian Ocean. The strain was rod-shaped and motile with a terminal flagellum, and formed yellowish colonies. It produced catalase and oxidase, hydrolysed gelatin and reduced nitrate. 16S rRNA gene sequence analysis showed that strain 8047(T) belonged to the order Rhizobiales of the class Alphaproteobacteria, and was phylogenetically most closely related to the genus Fulvimarina, sharing 94.4% sequence identity with the type strain of the type species. The taxonomic affiliation of strain 8047(T) was supported by phylogenetic analysis of four additional housekeeping genes, gyrB, recA, rpoC and rpoB. The predominant respiratory lipoquinone of strain 8047(T) was Q-10, the major fatty acid was C(18 : 1)ω7c and the DNA G+C content was 61.7 mol%. On the basis of the phenotypic and genotypic characteristics determined in this study, strain 8047(T) represents a novel species within the genus Fulvimarina, for which the name Fulvimarina manganoxydans sp. nov. is proposed. The type strain is strain 8047(T) ( = CGMCC1.10972(T) = JCM 18890(T)). PMID:24854008

  15. Janibacter indicus sp. nov., isolated from hydrothermal sediment of the Indian Ocean.

    PubMed

    Zhang, Gaiyun; Ren, Huihui; Wang, Shuang; Chen, Xiu; Yang, Yanliu; Zhang, Yubian; Jiang, Yi

    2014-07-01

    A Gram-staining-positive, aerobic and non-motile strain, 0704P10-1(T), was isolated from hydrothermal sediment of the Indian Ocean. Phylogenetic, phenotypic and chemotaxonomic data for the organism supported that it belonged to the genus Janibacter. Strain 0704P10-1(T) showed 97.2-98.7% 16S rRNA gene sequence similarities to the type strains of recognized members of the genus Janibacter. It contained meso-diaminopimelic acid as the diagnostic diamino acid in the cell wall. MK-8(H4) was the only menaquinone detected. The major fatty acids were iso-C16 : 0, C17 : 1ω8c and 10-methyl C17 : 0. Meanwhile, the results of DNA-DNA hybridization studies and other physiological and biochemical tests allowed the genotypic and phenotypic differentiation of strain 0704P10-1(T) from closely related species. Thus, strain 0704P10-1(T) represents a novel species of the genus Janibacter, for which the name Janibacter indicus sp. nov. is proposed. The type strain is 0704P10-1(T) ( = LMG 27493(T) = CGMCC 1.12511(T)). PMID:24744020

  16. Pseudomonas tuomuerensis sp. nov., isolated from a bird's nest.

    PubMed

    Xin, Yu-Hua; Zhang, De-Chao; Liu, Hong-Can; Zhou, Hui-Ling; Zhou, Yu-Guang

    2009-01-01

    Strain 78-123T was isolated from a sample of a bird's nest situated on the bank of Qiongtailan River in the region of Tuomuer Peak of Tianshan Mountain in the Xin-jiang Uygur Autonomous Region in north-western China. Phylogenetic analysis based on 16S rRNA gene sequence similarity showed that strain 78-123T was related to members of the genus Pseudomonas. 16S rRNA gene sequence similarity between strain 78-123T and Pseudomonas mendocina ATCC 25411T, Pseudomonas pseudoalcaligenes JCM 5968T and Pseudomonas alcaliphila AL15-21T was 97.1, 97.4 and 97.5 %, respectively. The major cellular fatty acids were C(16 : 0), C(16 : 1)omega7c and/or iso-C(15 : 0) 2-OH, C(18 : 1)omega7c and C(12 : 0). The G+C content was 60.4 mol%. On the basis of the phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, the novel species Pseudomonas tuomuerensis sp. nov. is proposed, with the type strain 78-123T (=CGMCC 1.1365T =JCM 14085T). PMID:19126738

  17. Sphingomonas arantia sp. nov., isolated from Hoh Xil basin, China.

    PubMed

    Jia, Li; Zheng, Zhong; Feng, Xiaomin; Nogi, Yuichi; Yang, Aichen; Zhang, Yali; Han, Lu; Lu, Zhenquan; Lv, Jie

    2015-12-01

    A Gram-negative, rod-shaped, non-motile, non-spore forming, aerobic, orange-pigmented bacterium, designated strain 6P(T), was isolated from a soil sample collected from the Hoh Xil basin, China. Strain 6P(T) grew optimally at 25 °C, pH 7.0-7.5 and NaCl concentration of 0-1 % (w/v). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 6P(T) belongs to the genus Sphingomonas, with high sequence similarity (97.1 %) to Sphingomonas fennica. The DNA-DNA hybridization homology with S. fennica DSM 13665(T) was 45.3 %. The DNA G+C content of the novel strain is 65.3 mol%. The isolate contained Q-10 as the only respiratory quinone. The major polar lipids are diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylcholine (PC) and sphingoglycolipid (SGL). C18:1 ω7c and C16:1 ω7c are the major fatty acids. On the basis of the polyphasic evidence presented, strain 6P(T) represents a novel species of the genus Sphingomonas, for which the name Sphingomonas arantia sp. nov. is proposed. The type strain is 6P(T) (=CGMCC 1.12702(T) = JCM 19855(T)). PMID:26363912

  18. Performance of a new thermostable mannanase in breaking guar-based fracturing fluids at high temperatures with little premature degradation.

    PubMed

    Hu, Ke; Li, Chun-Xiu; Pan, Jiang; Ni, Yan; Zhang, Xiao-Yan; Xu, Jian-He

    2014-02-01

    A new thermostable β-1,4-mannanase (DtManB) cloned from Dictyoglomus thermophilum CGMCC 7283 showed the maximum activity towards hydroxypropyl guar gum at 80 °C, with a half-life of 46 h. DtManB exhibited good compatibility with various additives of fracturing fluid, retaining more than 50 % activity in all the cases tested. More importantly, premature degradation could be alleviated significantly when using DtManB as breaker, because at 27 and 50 °C it displayed merely 3.7 and 18.5 % activities compared to those at 80 °C. In a static test, 0.48 mg DtManB could break 200 mL borax cross-linked fracturing fluid dramatically at 80 °C, and merely 18 mPa s of the viscosity was detected even after the broken fluid was cooled down and only 161.4 mg L(-1) of the residue was left after the enzymatic reaction. All these positive features demonstrate the great potential of this mannanase as a new enzyme breaker for application in enhanced recovery of petroleum oil. PMID:24150905

  19. Arthrobacter liuii sp. nov., resuscitated from Xinjiang desert soil.

    PubMed

    Yu, Xiao-Yun; Zhang, Li; Ren, Biao; Yang, Na; Liu, Mei; Liu, Xue-Ting; Zhang, Li-Xin; Ding, Lin-Xian

    2015-03-01

    A Gram-stain positive, aerobic, non-motile actinobacterium, designated DSXY973(T), was isolated from soil samples collected from Xinjiang desert using medium supplemented with resuscitation-promoting factor, and subjected to a polyphasic taxonomic investigation. Phylogenetic analysis based on 16S rRNA gene sequences revealed that DSXY973(T) belonged to the genus Arthrobacter and was most closely related to Arthrobacter oryzae JCM 15922(T) with 97.1 % similarity. The DNA G+C content was 67.6 %. Cells of strain DSXY973(T) mainly contained MK-9(H2), and the cell wall contained l-lysine as the primary diamino acid. The major cellular fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C15 : 0. Strain DSXY973(T) was positive for catalase and negative for oxidase activity. On the basis of its phylogenetic position and phenotypic properties, strain DSXY973(T) represents a novel species of the genus Arthrobacter, for which the name Arthrobacter liuii sp. nov. is proposed. The type strain is DSXY973(T) ( = CGMCC1.12778(T) = JCM 19864(T)). PMID:25525122

  20. Arthrobacter alpinus sp. nov., a psychrophilic bacterium isolated from alpine soil.

    PubMed

    Zhang, De-Chao; Schumann, Peter; Liu, Hong-Can; Xin, Yu-Hua; Zhou, Yu-Guang; Schinner, Franz; Margesin, Rosa

    2010-09-01

    An aerobic, Gram-reaction-positive, non-motile, psychrophilic bacterium, designated strain S6-3(T), was isolated from alpine soil. Cells exhibited a rod-coccus growth cycle and produced a yellow pigment. Growth occurred at 1-25 degrees C. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain S6-3(T) was related to members of the genus Arthrobacter, sharing highest sequence similarities with the type strains of Arthrobacter psychrolactophilus (97.9 %) and Arthrobacter stackebrandtii (97.6 %). Strain S6-3(T) had MK-9(H(2)) as the major menaquinone and anteiso-C(15 : 0) as the major fatty acid. The cell-wall peptidoglycan was of type A3alpha l-Lys-l-Thr-Ala(3). The predominant cell-wall sugars were galactose and rhamnose. The genomic DNA G+C content of strain S6-3(T) was 61.9 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strain S6-3(T) is considered to represent a novel species of the genus Arthrobacter, for which the name Arthrobacter alpinus sp. nov. is proposed. The type strain is S6-3(T) (=DSM 22274(T) =CGMCC 1.8950(T)). PMID:19880631

  1. Arthrobacter cupressi sp. nov., an actinomycete isolated from the rhizosphere soil of Cupressus sempervirens.

    PubMed

    Zhang, Jian; Ma, Yuchao; Yu, Huimin

    2012-11-01

    An actinobacterial strain, designated D48(T), was isolated from the rhizosphere soil of a cypress tree collected from Mianyang in Sichuan province, China. The strain was Gram-stain-positive, catalase-positive, oxidase-negative and non-motile, with lysine as the peptidoglycan diagnostic diamino acid and acetyl as the peptidoglycan acyl type. The predominant menaquinone was MK-9(H(2)); small amounts of MK-7(H(2)), MK-10(H(2)) and MK-6 were also present. The major fatty acids were anteiso-C(15:0), anteiso-C(17:0) and iso-C(16:0). The isolate underwent a rod-coccus morphological cycle, had a high DNA G+C content, was aerobic and grew between 12 and 37 °C (optimum, 28 °C). On the basis of the phenotypic and chemotaxonomic analyses, 16S rRNA gene sequence comparisons and DNA-DNA hybridization data, the isolate represents a novel species of the genus Arthrobacter, for which the name Arthrobacter cupressi sp. nov. is proposed. The type strain is D48(T) (=DSM 24664(T)=CGMCC 1.10783(T)). PMID:22228666

  2. Arthrobacter cryoconiti sp. nov., a psychrophilic bacterium isolated from alpine glacier cryoconite.

    PubMed

    Margesin, Rosa; Schumann, Peter; Zhang, De-Chao; Redzic, Mersiha; Zhou, Yu-Guang; Liu, Hong-Can; Schinner, Franz

    2012-02-01

    A Gram-stain-positive, aerobic, non-motile, psychrophilic bacterium, designated strain Cr6-08(T), was isolated from alpine glacier cryoconite. Growth of strain Cr6-08(T) occurred at 1-25 °C. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain Cr6-08(T) is most closely related to members of the genus Arthrobacter. Strain Cr6-08(T) possessed chemotaxonomic properties consistent with those of the genus Arthrobacter, such as peptidoglycan type A3α (l-Lys-L-Ala(4)), MK-9(H(2)) as major menaquinone and anteiso- and iso-branched compounds (anteiso-C(15 : 0) and iso-C(15 : 0)) as major cellular fatty acids. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unknown glycolipid and three unknown polar lipids. The genomic DNA G+C content of strain Cr6-08(T) was 57.3 mol%. On the basis of phenotypic and chemotaxonomic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strain Cr6-08(T) is considered to represent a novel species of the genus Arthrobacter, for which the name Arthrobacter cryoconiti sp. nov. is proposed. The type strain is Cr6-08(T) ( = DSM 23324(T)  = LMG 26052(T)  = CGMCC 1.10698(T)). PMID:21441372

  3. Binariimonas pacifica gen. nov., sp. nov., a Novel Marine Bacterium of Family Sphingomonadaceae Isolated from East Pacific Ocean Surface Seawater.

    PubMed

    Zhao, Zhao; Sun, Jia; Zhang, Rui; Jiao, Nianzhi

    2016-03-01

    A novel rod-shaped binary fission, and yellow-pigmented bacterial strain, JLT 2480(T), was isolated from surface seawater in the East Pacific Ocean. The strain is Gram negative and oxidase negative. Phylogenetic analyses based on 16S rRNA gene sequence indicate that strain JLT 2480(T) falls in the family Sphingomonadaceae, sharing highest similarity (95.6 %) with the species Blastomonas ursincola. The DNA G+C content of JLT 2480(T) is 65.5 mol%, and the sole respiratory quinone is coenzyme Q10. The predominant polar lipids are sphingoglycolipids (SGL1 and SGL2), phosphatidylglycerols, phosphatidylethanolamines, phospholipids, glycolipids, and phosphatidylcholines. The predominant cellular fatty acids are C16:0, C18:0, C18:1ω7c, C12:0, and C16:1ω7c. Strain JLT 2480(T) is distinct from the B. ursincola type strain DSM 9006(T) as reflected by major chemotaxonomic distinctions between the two. Furthermore, two notable characteristics of the genus Blastomonas, that is, the presence of bacteriochlorophyll a and the puf genes, are not detected in JLT 2480(T). On the basis of present evidence, we consider JLT 2480(T) to be a novel species in a new genus of the family Sphingomonadaceae, and propose the name Binariimonas pacifica gen. nov., sp. nov., with strain JLT 2480(T) (=CGMCC 1.12850(T) = DSM 28646(T)) to be the type strain for genus Binariimonas. PMID:26613616

  4. Tianweitania sediminis gen. nov., sp. nov., a member of the family Phyllobacteriaceae, isolated from subsurface sediment core.

    PubMed

    Han, Lu; Mo, Yongxin; Feng, Qingqing; Zhang, Rengang; Zhao, Xingmin; Lv, Jie; Xie, Bing

    2016-02-01

    A bacterial strain, designated Z8T, was isolated from the terrestrial sediment of the Mohe Basin in north-east China. Phylogenetic analyses of 16S rRNA genes showed that this strain belonged to the family Phyllobacteriaceae, and was most closely related to Phyllobacterium bourgognense, with a sequence similarity of 96.9 %. The major cellular fatty acids were summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B) and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The major respiratory quinone was ubiquinone-10. The three major polar lipids of strain Z8T consisted of glycolipids, phosphatidylethanolamine and phosphatidylmethylethanolamine. The DNA G+C content was 59.6 mol%. The chemotaxonomic characteristics of strain Z8T differed in some respects from those of members of the family Phyllobacteriaceae. Based on phylogenetic, phenotypic and chemotaxonomic data, strain Z8T is considered to represent a novel species of a novel genus within the family Phyllobacteriaceae, for which the name Tianweitania sediminis gen. nov., sp. nov. is proposed. The type strain is Z8T ( = CGMCC 1.12944T = JCM 30358T). PMID:26597787

  5. Clostridium luticellarii sp. nov., isolated from a mud cellar used for producing strong aromatic liquors.

    PubMed

    Wang, Qian; Wang, Chuan-Dong; Li, Cheng-Hou; Li, Jun-Gang; Chen, Qi; Li, Yue-Zhong