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Sample records for stenotrophomonas maltophilia cgmcc

  1. 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

  2. Heavy Metal Tolerance in Stenotrophomonas maltophilia

    PubMed Central

    Pages, Delphine; Rose, Jerome; Conrod, Sandrine; Cuine, Stephane; Carrier, Patrick; Heulin, Thierry; Achouak, Wafa

    2008-01-01

    Stenotrophomonas maltophilia is an aerobic, non-fermentative Gram-negative bacterium widespread in the environment. S. maltophilia Sm777 exhibits innate resistance to multiple antimicrobial agents. Furthermore, this bacterium tolerates high levels (0.1 to 50 mM) of various toxic metals, such as Cd, Pb, Co, Zn, Hg, Ag, selenite, tellurite and uranyl. S. maltophilia Sm777 was able to grow in the presence of 50 mM selenite and 25 mM tellurite and to reduce them to elemental selenium (Se0) and tellurium (Te0) respectively. Transmission electron microscopy and energy dispersive X-ray analysis showed cytoplasmic nanometer-sized electron-dense Se0 granules and Te0 crystals. Moreover, this bacterium can withstand up to 2 mM CdCl2 and accumulate this metal up to 4% of its biomass. The analysis of soluble thiols in response to ten different metals showed eightfold increase of the intracellular pool of cysteine only in response to cadmium. Measurements by Cd K-edge EXAFS spectroscopy indicated the formation of Cd-S clusters in strain Sm777. Cysteine is likely to be involved in Cd tolerance and in CdS-clusters formation. Our data suggest that besides high tolerance to antibiotics by efflux mechanisms, S. maltophilia Sm777 has developed at least two different mechanisms to overcome metal toxicity, reduction of oxyanions to non-toxic elemental ions and detoxification of Cd into CdS. PMID:18253487

  3. 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

  4. 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

  5. Antifolate Activity of Epigallocatechin Gallate against Stenotrophomonas maltophilia

    PubMed Central

    Navarro-Martínez, María Dolores; Navarro-Perán, Enma; Cabezas-Herrera, Juan; Ruiz-Gómez, Joaquín; García-Cánovas, Francisco; Rodríguez-López, José Neptuno

    2005-01-01

    The catechin epigallocatechin gallate, one of the main constituents of green tea, showed strong antibiotic activity against 18 isolates of Stenotrophomonas maltophilia (MIC range, 4 to 256 ?g/ml). In elucidating its mechanism of action, we have shown that epigallocatechin gallate is an efficient inhibitor of S. maltophilia dihydrofolate reductase, a strategic enzyme that is considered an attractive target for the development of antibacterial agents. The inhibition of S. maltophilia dihydrofolate reductase by this tea compound was studied and compared with the mechanism of a nonclassical antifolate compound, trimethoprim. Investigation of dihydrofolate reductase was undertaken with both a trimethoprim-susceptible S. maltophilia isolate and an isolate with a high level of resistance. The enzymes were purified using ammonium sulfate precipitation, gel filtration, and methotrexate affinity chromatography. The two isolates showed similar levels of dihydrofolate reductase expression and similar substrate kinetics. However, the dihydrofolate reductase from the trimethoprim-resistant isolate demonstrated decreased susceptibility to inhibition by trimethoprim and epigallocatechin gallate. As with other antifolates, the action of epigallocatechin gallate was synergistic with that of sulfamethoxazole, a drug that blocks folic acid metabolism in bacteria, and the inhibition of bacterial growth was attenuated by including leucovorin in the growth medium. We conclude that the mechanism of action of epigallocatechin gallate on S. maltophilia is related to its antifolate activity. PMID:15980368

  6. Stenotrophomonas maltophilia Infections in Adults: Primary Bacteremia and Pneumonia

    PubMed Central

    Gokhan Gozel, Mustafa; Celik, Cem; Elaldi, Nazif

    2015-01-01

    Background: Stenotrophomonas maltophilia is the third most frequent non-fermentative Gram-negative bacilli in nosocomial infections, and usually causes severe infections such as primary bacteremia and pneumonia. Objectives: The current study aimed to compare the demographic and clinical characteristics, microbiological findings and final outcomes of the patients with primary bacteremia and nosocomial pneumonia caused by S. maltophilia. Patients and Methods: The current study retrospectively evaluated patients aged 18 years and above with primary bacteremia and nosocomial pneumonia caused by S. maltophilia from January 2006 to December 2013. Medical records of patients, including reports of clinical microbiology and hospital infection control committee, were evaluated. Results: A total of 71 patients with S. maltophilia nosocomial infections, 35 (49.3%) primary bacteremia and 36 (50.7%) pneumonia, were diagnosed. There were no significant differences in gender, age, and co-morbid diseases, except chronic obstructive pulmonary disease; this infection was significantly higher in patients with pneumonia. A slightly higher 14-day mortality was found in patients with pneumonia, but the difference was not statistically significant. Inappropriate antibiotic use and presence of multiple organ dysfunction syndrome were found as independent risk factors for 14-day mortality in multivariate analysis. Conclusions: A slightly higher mortality in patients with pneumonia, caused by S. maltophilia, was strived to explain by advanced age, higher acute physiology and chronic health evaluation (APACHE II) and sepsis related organ failure assessment (SOFA) score, and also higher inappropriate antibiotic use. PMID:26468367

  7. Clinical ineffectiveness of latamoxef for Stenotrophomonas maltophilia infection

    PubMed Central

    Hagiya, Hideharu; Tasaka, Ken; Sendo, Toshiaki; Otsuka, Fumio

    2015-01-01

    Objectives Stenotrophomonas maltophilia shows wide-spectrum resistance to antimicrobials and causes various infections in immunocompromised or critically ill patients with high mortality. In this era of antibiotics resistance, a revival of old antibiotics is now featured. We examined the clinical usefulness of latamoxef (LMOX) for the treatment of S. maltophilia infection. Patients and methods The observational study was retrospectively performed at Okayama University Hospital (Okayama, Japan) from January 2011 to December 2013. LMOX was administered to 12 patients with S. maltophilia infection, with eleven of those patients being admitted to the intensive care unit. Results Underlying conditions of the patients included postoperation, hematological transplantation, hepatic transplantation, and burn. Major infectious foci were surgical site infection (six cases), respiratory infection (four cases), blood stream infection (three cases), and burn site infection (one case). The doses of LMOX administered ranged from 1 g/d to 3 g/d for ten adult patients and from 40 mg/kg/d to 80 mg/kg/d for two pediatric patients. Microbiologic failure was seen in five (41.7%) of 12 cases, and 30-day and hospital mortality rates were 25% and 50%, respectively. Minimum inhibitory concentrations of LMOX were higher in the deceased group (4–64 µg/mL) than in the surviving group (1–4 µg/mL). Conclusion LMOX treatment is not recommended for the treatment of S. maltophilia infection. Further investigation would be needed before its clinical use. PMID:26527890

  8. 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

  9. 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

  10. Draft Genome Sequence of Stenotrophomonas maltophilia Strain M30, Isolated from a Chronic Pressure Ulcer in an Elderly Patient

    PubMed Central

    Huedo, Pol; Conchillo-Solé, Óscar; Yero, Daniel; Martínez-Servat, Sònia

    2014-01-01

    Stenotrophomonas maltophilia is an emerging opportunistic pathogen with an increasing prevalence of multidrug-resistant strains. Here, we report the draft genome sequence of S. maltophilia strain M30, isolated from a pressure ulcer in an elderly patient. PMID:24926059

  11. Draft Genome Sequence of Stenotrophomonas maltophilia Strain M30, Isolated from a Chronic Pressure Ulcer in an Elderly Patient.

    PubMed

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

    2014-01-01

    Stenotrophomonas maltophilia is an emerging opportunistic pathogen with an increasing prevalence of multidrug-resistant strains. Here, we report the draft genome sequence of S. maltophilia strain M30, isolated from a pressure ulcer in an elderly patient. PMID:24926059

  12. 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

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

    PubMed Central

    Akbar, Sirwan; Rout, Simon P.

    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

  14. 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

  15. Stenotrophomonas Maltophilia Endophthalmitis Caused by Surgical Equipment Contamination: an Emerging Nosocomial Infection

    PubMed Central

    Williams, Maria A.; Gramajo, Ana L.; Colombres, Gustavo A.; Caeiro, Juan P.; Juárez, Claudio P.; Luna, José D.

    2014-01-01

    Purpose: We report three cases of Stenotrophomonas maltophilia endophthalmitis after uneventful extracapsular cataract extraction with intraocular lens implantation-related to surgical equipment contamination. Case report: All patients developed acute, culture-positive endophthalmitis in a period ranging from 2 to 13 days. Cultures from vitreous tap, as well as those obtained from the hand-piece of the irrigation-aspiration system, revealed S. maltophilia as the causing infectious agent. All patients received intravitreal antibiotic treatment as initial therapy, nevertheless, visual disturbance continued to be present, hence pars plana vitrectomy was required. Conclusion: Contamination of surgical-reusable equipment should be considered in addition to the well-known risk factors associated with development of endophthalmitis by S. maltophilia. PMID:25667741

  16. 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

  17. 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

  18. 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 ?-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

  19. 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

  20. Genome sequence of Stenotrophomonas maltophilia S028, an isolate harboring the AmpR-L2 resistance module.

    PubMed

    Song, Shiping; Yuan, Xitong; Liu, Shiwei; Zhang, Ning; Wang, Yufei; Ke, Yuehua; Xu, Jie; Huang, Liuyu; Chen, Zeliang; Li, Yan

    2012-12-01

    Multidrug-resistant Stenotrophomonas maltophilia has emerged as an important cause of nosocomial infections, which is attributable mainly to the production of diverse ?-lactamases by S. maltophilia. The L2 ?-lactamase mediated by the AmpR-L2 module is the most represented lactamase. Here, we announce the genome sequence of S028, an isolate harboring the AmpR-L2 module. PMID:23144428

  1. Phenotypic Heterogeneity Affects Stenotrophomonas maltophilia K279a Colony Morphotypes and ?-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 ?-lactamases in response to ?-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

  2. 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

  3. The DSF Quorum Sensing System Controls the Positive Influence of Stenotrophomonas maltophilia on Plants

    PubMed Central

    Alavi, Peyman; Müller, Henry; Cardinale, Massimiliano; Zachow, Christin; Sánchez, María B.; Martínez, José Luis; Berg, Gabriele

    2013-01-01

    The interaction of the Gram-negative bacterium Stenotrophomonas maltophilia with eukaryotes can improve overall plant growth and health, but can also cause opportunistic infections in humans. While the quorum sensing molecule DSF (diffusible signal factor) is responsible for the regulation of phenotypes in pathogenic Stenotrophomonas, up until now, no beneficial effects were reported to be controlled by it. Our objective was to study the function of DSF in the plant growth promoting model strain S. maltophilia R551-3 using functional and transcriptomic analyses. For this purpose, we compared the wild-type strain with a mutant deficient in the rpfF (regulation of pathogenicity factors) gene that is essential for the synthesis of DSF. Oilseed rape seeds treated with the wild-type strain showed a statistically significant increase in germination rate compared with those treated with the rpfF mutant. Similarly, the wild-type strain exhibited better plant growth promotion and a greater efficiency in colonizing oilseed rape compared to the mutant strain. Moreover, only the wild-type was capable of forming structured cell aggregates both in vitro and in the rhizosphere, a characteristic mediated by DSF. Gene transcription analyses showed that numerous genes known to play a role in plant colonization (e.g. chemotaxis, cell motility, biofilm formation, multidrug efflux pumps) are controlled by the rpf/DSF system in S. maltophilia. In addition, we detected new potential functions of spermidine, primarily for both growth promotion and stress protection. Overall, our results showed a correspondence between the regulation of DSF and the positive interaction effect with the plant host. PMID:23874407

  4. [Lower respiratory tract infections related to Stenotrophomonas maltophilia and Acinetobacter baumannii].

    PubMed

    Baranzelli, A; Wallyn, F; Nseir, S

    2013-10-01

    Stenotrophomonas maltophilia and Acinetobacter baumannii are both non-fermenting ubiquitous Gram-negative bacilli. The incidence of lower respiratory tract infections related to these microorganisms is increasing, especially in intensive care units. Their capacity to acquire resistance against several antimicrobials is challenging for clinicians and microbiologists. Despite their low virulence, these pathogens are responsible for colonization and infection in patients with comorbidities, immunosuppression, and critically ill patients. S. maltophilia and A. baumannii are mainly identified in nosocomial infections: ventilator-associated pneumonia, bacteremia and surgical wound infection. Infections related to these microorganism are associated with high mortality and morbidity. Trimethoprime-sulfamethoxazole and carbapenem are the first line treatment for infections related to S. maltophilia and A. baumannii respectively. However, the increasing rate of resistance against these agents results in difficulties in treating patients with infections related to these pathogens. New antimicrobial agents and further randomized studies are needed to improve the treatment of these infections. Prevention of spared of these multidrug-resistant bacteria is mandatory, including hand-hygiene, environment cleaning, and limited usage of large spectrum antibiotics. PMID:23583504

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

    PubMed Central

    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 ?-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

  6. 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

  7. 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

  8. 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 ?-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, KJ?CreD; and the complementary strain, KJ?CreD(pCreD). The mutant lacking creD had cell division defects and aberrations in cell envelope integrity, which then triggered the ?E-mediated envelope stress response. Thus, the results indicated that CreD plays a critical role in the maintenance of envelope integrity. PMID:26698119

  9. Nosocomial outbreak of colonization and infection with Stenotrophomonas maltophilia in preterm infants associated with contaminated tap water.

    PubMed Central

    Verweij, P. E.; Meis, J. F.; Christmann, V.; Van der Bor, M.; Melchers, W. J.; Hilderink, B. G.; Voss, A.

    1998-01-01

    Between March and May 1996 Stenotrophomonas maltophilia was cultured from endotracheal aspirate samples from five preterm infants in a neonatal intensive care unit (NICU). Four infants were superficially colonized, but a fifth died due to S. maltophilia septicaemia. S. maltophilia was cultured from tap water from three outlets in the NICU including one with a previously unnoticed defective sink drain. Water from these outlets was used to wash the preterm infants. Environmental and clinical S. maltophilia isolates yielded identical banding patterns on random arbitrary polymorphic DNA (RAPD) PCR analysis. The outbreak was controlled by reinforcement of hand disinfection, limitation of the use of tap water for hand washing and by using sterile water to wash the preterm infants. We conclude that tap water should not be used for washing preterm infants in the NICU, unless steps are taken to prevent microbial growth in the outlets. PMID:9692603

  10. Draft Genome Sequence of Stenotrophomonas maltophilia Strain B418, a Promising Agent for Biocontrol of Plant Pathogens and Root-Knot Nematode.

    PubMed

    Wu, Yuanzheng; Wang, Yilian; Li, Jishun; Hu, Jindong; Chen, Kai; Wei, Yanli; Bazhanov, Dmitry P; Bazhanova, Alesia A; Yang, Hetong

    2015-01-01

    Stenotrophomonas maltophilia strain B418 was isolated from a barley rhizosphere in China. This bacterium exhibits broad-spectrum inhibitory activities against plant pathogens and root-knot nematode along with growth-promoting effects. Here, we present the draft genome sequence of S. maltophilia B418. PMID:25700397

  11. Draft Genome Sequence of Stenotrophomonas maltophilia Strain 5BA-I-2, a Soil Isolate and a Member of a Phylogenetically Basal Lineage

    PubMed Central

    Nunvar, Jaroslav; Elhottova, Dana; Chronakova, Alica; Schneider, Bohdan

    2014-01-01

    Stenotrophomonas maltophilia is an omnipresent environmental bacterium emerging as an opportunistic human pathogen and exhibiting multidrug resistance. Here, we report the draft genome sequence of S. maltophilia strain 5BA-I-2, a soil isolate and a member of a phylogenetically basal lineage. PMID:24604648

  12. Draft Genome Sequence of Stenotrophomonas maltophilia Strain B418, a Promising Agent for Biocontrol of Plant Pathogens and Root-Knot Nematode

    PubMed Central

    Wu, Yuanzheng; Wang, Yilian; Li, Jishun; Hu, Jindong; Chen, Kai; Wei, Yanli; Bazhanov, Dmitry P.; Bazhanova, Alesia A.

    2015-01-01

    Stenotrophomonas maltophilia strain B418 was isolated from a barley rhizosphere in China. This bacterium exhibits broad-spectrum inhibitory activities against plant pathogens and root-knot nematode along with growth-promoting effects. Here, we present the draft genome sequence of S. maltophilia B418. PMID:25700397

  13. 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

  14. 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

  15. Modulation of FAD-dependent monooxygenase activity from aromatic compounds-degrading Stenotrophomonas maltophilia strain KB2.

    PubMed

    Wojcieszy?ska, Danuta; Gre?, Izabela; Hupert-Kocurek, Katarzyna; Guzik, Urszula

    2011-01-01

    The purpose of this study was purification and characterization of phenol monooxygenase from Stenotrophomonas maltophilia strain KB2, enzyme that catabolises phenol and its derivatives through the initial hydroxylation to catechols. The enzyme requires NADH and FAD as a cofactors for activity, catalyses hydroxylation of a wide range of monocyclic phenols, aromatic acids and dihydroxylated derivatives of benzene except for catechol. High activity of this monooxygenase was observed in cell extract of strain KB2 grown on phenol, 2-methylphenol, 3-metylphenol or 4-methylphenol. Ionic surfactants as well as cytochrome P450 inhibitors or 1,4-dioxane, acetone and n-butyl acetate inhibited the enzyme activity, while non-ionic surfactants, chloroethane, ethylbenzene, ethyl acetate, cyclohexane, and benzene enhanced it. These results indicate that the phenol monooxygenase from Stenotrophomonas maltophilia strain KB2 holds great potential for bioremediation. PMID:21927719

  16. 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 e?ux 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

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

    PubMed Central

    Urszula, Guzik; Izabela, Gre?; Danuta, Wojcieszy?ska; Sylwia, ?abu?ek

    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

  18. 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

  19. 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 ?-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

  20. 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

  1. Control of Pseudomonas aeruginosa and Stenotrophomonas maltophilia contamination of microfiltered water dispensers with peracetic acid and hydrogen peroxide.

    PubMed

    Sacchetti, Rossella; De Luca, Giovanna; Zanetti, Franca

    2009-06-30

    The abilities of peracetic acid and hydrogen peroxide to remove or reduce Pseudomonas aeruginosa and Stenotrophomonas maltophilia in output water from microfiltered water dispensers (MWDs) were investigated. Two MWDs were inoculated with strains of P. aeruginosa and S. maltophilia isolated from water. Dispensers A and B were disinfected with 10% (v/v) peracetic acid (PAA) and 3% (v/v) hydrogen peroxide (HP) respectively. Each dispenser was disinfected three times at monthly intervals with contact times of 10, 30 and 40 min. Water dispensed by the MWDs was collected immediately before and after each treatment and then twice weekly for the remaining period. Once a week a sample of the tap water entering the dispensers was tested. P. aeruginosa and S. maltophilia were enumerated in the 90 samples collected during 6 months. In the output water from the dispensers before the first treatment, the number of the bacteria was 3 to 4 log cfu/100 mL. Treatment with PAA greatly reduced the numbers of P. aeruginosa and S. maltophilia in the dispensed water initially. However, by 2 days after treatment, the numbers increased and remained high. In the case of disinfection with HP for 40 min, P. aeruginosa was not detected in most of the samples (73.7%). Numbers of S. maltophilia decreased with increasing time after treatment. PMID:19439386

  2. 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 ?-D-N,N',N"-triacetylchitotriose and activity of 37 U/ml towards 4-Nitrophenyl N,N'-diacetyl-?-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

  3. 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

  4. The complete genome, comparative and functional analysis of Stenotrophomonas maltophilia reveals an organism heavily shielded by drug resistance determinants

    PubMed Central

    Crossman, Lisa C; Gould, Virginia C; Dow, J Maxwell; Vernikos, Georgios S; Okazaki, Aki; Sebaihia, Mohammed; Saunders, David; Arrowsmith, Claire; Carver, Tim; Peters, Nicholas; Adlem, Ellen; Kerhornou, Arnaud; Lord, Angela; Murphy, Lee; Seeger, Katharine; Squares, Robert; Rutter, Simon; Quail, Michael A; Rajandream, Mari-Adele; Harris, David; Churcher, Carol; Bentley, Stephen D; Parkhill, Julian; Thomson, Nicholas R; Avison, Matthew B

    2008-01-01

    Background Stenotrophomonas maltophilia is a nosocomial opportunistic pathogen of the Xanthomonadaceae. The organism has been isolated from both clinical and soil environments in addition to the sputum of cystic fibrosis patients and the immunocompromised. Whilst relatively distant phylogenetically, the closest sequenced relatives of S. maltophilia are the plant pathogenic xanthomonads. Results The genome of the bacteremia-associated isolate S. maltophilia K279a is 4,851,126 bp and of high G+C content. The sequence reveals an organism with a remarkable capacity for drug and heavy metal resistance. In addition to a number of genes conferring resistance to antimicrobial drugs of different classes via alternative mechanisms, nine resistance-nodulation-division (RND)-type putative antimicrobial efflux systems are present. Functional genomic analysis confirms a role in drug resistance for several of the novel RND efflux pumps. S. maltophilia possesses potentially mobile regions of DNA and encodes a number of pili and fimbriae likely to be involved in adhesion and biofilm formation that may also contribute to increased antimicrobial drug resistance. Conclusion The panoply of antimicrobial drug resistance genes and mobile genetic elements found suggests that the organism can act as a reservoir of antimicrobial drug resistance determinants in a clinical environment, which is an issue of considerable concern. PMID:18419807

  5. 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

  6. 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

  7. The investigation of nematocidal activity in Stenotrophomonas maltophilia G2 and characterization of a novel virulence serine protease.

    PubMed

    Huang, Xiaowei; Liu, Junwei; Ding, Junmei; He, Qiusheng; Xiong, Rui; Zhang, Keqin

    2009-08-01

    The Gram-negative bacterium Stenotrophomonas maltophilia G2 was isolated from a soil sample and was found to have high nematotoxic activity against a free-living nematode, Panagrellus redivivus, and a plant-parasitic nematode, Bursaphelenchus xylophilus. The analysis of virulence factors revealed that although the small molecular metabolites participated in nematode killing, the crude extracellular protein extract from the bacterial culture supernatant contributed significantly to its nematocidal activity. An extracellular protease was purified by chromatography, and its effects on degrading purified nematode cuticle and killing living nematodes were confirmed experimentally. Characterization of this purified protease revealed that the application of phenylmethylsulphonyl fluoride, an inhibitor of serine proteases, could completely abolish its proteolytic activity. The results from N-terminal amino acid sequencing showed no similarity with any known serine protease in S. maltophilia, suggesting a novel virulence serine protease was obtained. Our study is the first to show the nematocidal activity of S. maltophilia, and we identified a novel serine protease as an important pathogenicity factor. PMID:19898533

  8. 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

  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. Cooperative pathogenicity in cystic fibrosis: Stenotrophomonas maltophilia modulates Pseudomonas aeruginosa virulence in mixed biofilm

    PubMed Central

    Pompilio, Arianna; Crocetta, Valentina; De Nicola, Serena; Verginelli, Fabio; Fiscarelli, Ersilia; Di Bonaventura, Giovanni

    2015-01-01

    The present study was undertaken in order to understand more about the interaction occurring between S. maltophilia and P. aeruginosa, which are frequently co-isolated from CF airways. For this purpose, S. maltophilia RR7 and P. aeruginosa RR8 strains, co-isolated from the lung of a chronically infected CF patient during a pulmonary exacerbation episode, were evaluated for reciprocal effect during planktonic growth, adhesion and biofilm formation onto both polystyrene and CF bronchial cell monolayer, motility, as well as for gene expression in mixed biofilms. P. aeruginosa significantly affected S. maltophilia growth in both planktonic and biofilm cultures, due to an inhibitory activity probably requiring direct contact. Conversely, no effect was observed on P. aeruginosa by S. maltophilia. Compared with monocultures, the adhesiveness of P. aeruginosa on CFBE41o- cells was significantly reduced by S. maltophilia, which probably acts by reducing P. aeruginosa's swimming motility. An opposite trend was observed for biofilm formation, confirming the findings obtained using polystyrene. When grown in mixed biofilm with S. maltophilia, P. aeruginosa significantly over-expressed aprA, and algD—codifying for protease and alginate, respectively—while the quorum sensing related rhlR and lasI genes were down-regulated. The induced alginate expression by P. aeruginosa might be responsible for the protection of S. maltophilia against tobramycin activity we observed in mixed biofilms. Taken together, our results suggest that the existence of reciprocal interference of S. maltophilia and P. aeruginosa in CF lung is plausible. In particular, S. maltophilia might confer some selective “fitness advantage” to P. aeruginosa under the specific conditions of chronic infection or, alternatively, increase the virulence of P. aeruginosa thus leading to pulmonary exacerbation. PMID:26441885

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

    PubMed Central

    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.

    2015-01-01

    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

  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. [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. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. A Linkage between SmeIJK Efflux Pump, Cell Envelope Integrity, and ?E-Mediated Envelope Stress Response in Stenotrophomonas maltophilia

    PubMed Central

    Huang, Yi-Wei; Liou, Rung-Shiuan; Lin, Yi-Tsung; Huang, Hsin-Hui; Yang, Tsuey-Ching

    2014-01-01

    Resistance nodulation division (RND) efflux pumps, such as the SmeIJK pump of Stenotrophomonas maltophilia, are known to contribute to the multidrug resistance in Gram-negative bacteria. However, some RND pumps are constitutively expressed even though no antimicrobial stresses occur, implying that there should be some physical implications for these RND pumps. In this study, the role of SmeIJK in antimicrobials resistance, envelope integrity, and ?E-mediated envelope stress response (ESR) of S. maltophilia was assessed. SmeIJK was involved in the intrinsic resistance of S. maltophilia KJ to aminoglycosides and leucomycin. Compared with the wild-type KJ, the smeIJK deletion mutant exhibited growth retardation in the MH medium, an increased sensitivity to membrane-damaging agents (MDAs), as well as activation of an ?E-mediated ESR. Moreover, the expression of smeIJK was further induced by sub-lethal concentrations of MDAs or surfactants in an ?E-dependent manner. These data collectively suggested an alternative physiological role of smeIJK in cell envelope integrity maintenance and ?E-mediated ESR beyond the efflux of antibiotics. Because of the necessity of the physiological role of SmeIJK in protecting S. maltophilia from the envelope stress, smeIJK is constitutively expressed, which, in turn, contributes the intrinsic resistance to aminoglycoside and leucomycin. This is the first demonstration of the linkage among RND-type efflux pump, cell envelope integrity, and ?E-mediated ESR in S. maltophilia. PMID:25390933

  20. 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.

  1. 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

  2. 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

  3. Probing substrate binding to Metallo-?-Lactamase L1 from Stenotrophomonas maltophilia by using site-directed mutagenesis

    PubMed Central

    Carenbauer, Anne L; Garrity, James D; Periyannan, Gopal; Yates, Robert B; Crowder, Michael W

    2002-01-01

    Background The metallo-?-lactamases are Zn(II)-containing enzymes that hydrolyze the ?-lactam bond in penicillins, cephalosporins, and carbapenems and are involved in bacterial antibiotic resistance. There are at least 20 distinct organisms that produce a metallo-?-lactamase, and these enzymes have been extensively studied using X-ray crystallographic, computational, kinetic, and inhibition studies; however, much is still unknown about how substrates bind and the catalytic mechanism. In an effort to probe substrate binding to metallo-?-lactamase L1 from Stenotrophomonas maltophilia, nine site-directed mutants of L1 were prepared and characterized using metal analyses, CD spectroscopy, and pre-steady state and steady state kinetics. Results Site-directed mutations were generated of amino acids previously predicted to be important in substrate binding. Steady-state kinetic studies using the mutant enzymes and 9 different substrates demonstrated varying Km and kcat values for the different enzymes and substrates and that no direct correlation between Km and the effect of the mutation on substrate binding could be drawn. Stopped-flow fluorescence studies using nitrocefin as the substrate showed that only the S224D and Y228A mutants exhibited weaker nitrocefin binding. Conclusions The data presented herein indicate that Ser224, Ile164, Phe158, Tyr228, and Asn233 are not essential for tight binding of substrate to metallo-?-lactamase L1. The results in this work also show that Km values are not reliable for showing substrate binding, and there is no correlation between substrate binding and the amount of reaction intermediate formed during the reaction. This work represents the first experimental testing of one of the computational models of the metallo-?-lactamases. PMID:11876827

  4. 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

  5. Biofilm formation by Stenotrophomonas maltophilia isolates from device-associated nosocomial infections.

    PubMed

    Passerini de Rossi, B; Calenda, M; Vay, C; Franco, M

    2007-01-01

    Medical devices are often colonized by bacteria which may cause severe infections. The aim of this work was to evaluate biofilm formation by S. maltophilia isolates from device-associated nosocomial infections. The 13 local isolates exhibited different capacities of biofilm formation on hydrophilic and hydrophobic surfaces. All isolates formed strong biofilms in polystyrene microplates, while strong, moderate or weak biofilms were detected in borosilicate (BS) or polypropylene (PP) tubes. The proficiency of biofilm formation was better evaluated by the level of crystal violet staining expressed relative to the final culture density. The microscopic analysis of biofilms formed on glass coverslips revealed the presence of a matrix of exopolysaccharides and microcolonies typical of biofilm architecture. Isolates with increased adhesion to BS showed larger microcolonies. According to our results, twitching correlated well with attachment to the three abiotic surfaces tested, while swimming only showed a slight correlation with biofilm formation on PP. Poor correlation was observed between cell surface hydrophobicity and biofilm formation. One of the highest biofilm-producing isolates adhered to urethral catheters of different materials, and exhibited an increased resistance to oxidative stress, one of the common stresses encountered by bacteria during the infection process due to the immune response. PMID:18390153

  6. 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, KJ?YZ, 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 KJ?YZ 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

  7. 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

  8. Stenotrophomonas maltophilia interferes via the DSF-mediated quorum sensing system with Candida albicans filamentation and its planktonic and biofilm modes of growth.

    PubMed

    de Rossi, Beatriz Passerini; García, Carlos; Alcaraz, Eliana; Franco, Mirta

    2014-01-01

    Stenotrophomonas maltophilia is a nosocomial pathogen of increasing importance. S. maltophilia K279a genome encodes a diffusible signal factor (DSF) dependent quorum sensing (QS) system that was first identified in Xanthomonas campestris pv. campestris. DSF from X. campestris is a homologue of farnesoic acid, a Candida albicans QS signal which inhibits the yeast-to-hyphal shift. Here we describe the antagonistic effects of S. maltophilia on C. albicans on filamentation as well as on its planktonic and biofilm modes of growth. To determine the role of the DSF-mediated quorum sensing system in these effects, C. albicans ATCC 10231 and C. albicans tup1 mutant, locked in the filamentous form, were grown with K279a or with its rpfF deletion mutant (DSF-). A significant reduction in viable counts of C. albicans was observed in planktonic cocultures with K279a as well as in mixed biofilms. Furthermore, no viable cells of C. albicans tup1 were recovered from K279a mixed biofilms. Fungal viability was also assessed by labeling biofilms with SYTO 9 and propidium iodide. Confocal images showed that K279a can kill hyphae and also yeast cells. Light microscopic analysis showed that K279a severely affects hyphae integrity. On the other hand, the presence of K279a rpfF did not affect fungal morphology or viability. In conclusion, we report for the first time that S. maltophilia interferes with two key virulence factors of C. albicans, the yeast-to-hyphal transition and biofilm formation. DSF could be directly responsible for these effects or may induce the gene expression involved in antifungal activity. PMID:25576410

  9. 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 ?-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-?-lactamase and L2 serine-?-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-?2-11-methyl-dodecenoic acid and, to a lesser extent, the Burkholderia cenocepacia DSF cis-?2-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 ?-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

  10. Two Different rpf Clusters Distributed among a Population of Stenotrophomonas maltophilia Clinical Strains Display Differential Diffusible Signal Factor Production and Virulence Regulation

    PubMed Central

    Huedo, Pol; Yero, Daniel; Martínez-Servat, Sònia; Estibariz, Iratxe; Planell, Raquel; Martínez, Paula; Ruyra, Àngels; Roher, Nerea; Roca, Ignasi; Vila, Jordi

    2014-01-01

    The quorum-sensing (QS) system present in the emerging nosocomial pathogen Stenotrophomonas maltophilia is based on the signaling molecule diffusible signal factor (DSF). Production and detection of DSF are governed by the rpf cluster, which encodes the synthase RpfF and the sensor RpfC, among other components. Despite a well-studied system, little is known about its implication in virulence regulation in S. maltophilia. Here, we have analyzed the rpfF gene from 82 S. maltophilia clinical isolates. Although rpfF was found to be present in all of the strains, it showed substantial variation, with two populations (rpfF-1 and rpfF-2) clearly distinguishable by the N-terminal region of the protein. Analysis of rpfC in seven complete genome sequences revealed a corresponding variability in the N-terminal transmembrane domain of its product, suggesting that each RpfF variant has an associated RpfC variant. We show that only RpfC–RpfF-1 variant strains display detectable DSF production. Heterologous rpfF complementation of ?rpfF mutants of a representative strain of each variant suggests that RpfF-2 is, however, functional and that the observed DSF-deficient phenotype of RpfC–RpfF-2 variant strains is due to permanent repression of RpfF-2 by RpfC-2. This is corroborated by the ?rpfC mutant of the RpfC–RpfF-2 representative strain. In line with this observations, deletion of rpfF from the RpfC–RpfF-1 strain leads to an increase in biofilm formation, a decrease in swarming motility, and relative attenuation in the Caenorhabditis elegans and zebrafish infection models, whereas deletion of the same gene from the representative RpfC–RpfF-2 strain has no significant effect on these virulence-related phenotypes. PMID:24769700

  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. 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

  13. A cyclic AMP receptor protein-regulated cell-cell communication system mediates expression of a FecA homologue in Stenotrophomonas maltophilia.

    PubMed

    Huang, Tzu-Pi; Wong, Amy C Lee

    2007-08-01

    Stenotrophomonas maltophilia WR-C possesses an rpf/diffusible signal factor (DSF) cell-cell communication system. It produces cis-Delta2-11-methyl-dodecenoic acid, a DSF, and seven structural derivatives, which require rpfF and rpfB for synthesis. Acquisition of iron from the environment is important for bacterial growth as well as the expression of virulence genes. We identified a gene homologous to fecA, which encodes a ferric citrate receptor that transports exogenous siderophore ferric citrate from the environment into the bacterial periplasm. Western blot analysis with anti-FecA-His(6) antibody showed that the FecA homologue was induced in the iron-depleted medium supplemented with a low concentration of ferric citrate. Deletion of rpfF or rpfB resulted in reduced FecA expression compared to the wild type. Synthetic DSF restored FecA expression by the DeltarpfF mutant to the wild-type level. Reverse transcription-PCR showed that the fecA transcript was decreased in the DeltarpfF mutant compared to the wild type. These data suggest that DSF affected the level of fecA mRNA. Transposon inactivation of crp, which encodes cyclic AMP (cAMP) receptor protein (CRP) resulted in reduced FecA expression and rpfF transcript level. Putative CRP binding sites were located upstream of the rpfF promoter, indicating that the effect of CRP on FecA is through the rpf/DSF pathway and by directly controlling rpfF. We propose that CRP may serve as a checkpoint for iron uptake, protease activity, and hemolysis in response to environmental changes such as changes in concentrations of glucose, cAMP, iron, or DSF. PMID:17574998

  14. A Cyclic AMP Receptor Protein-Regulated Cell-Cell Communication System Mediates Expression of a FecA Homologue in Stenotrophomonas maltophilia?

    PubMed Central

    Huang, Tzu-Pi; Wong, Amy C. Lee

    2007-01-01

    Stenotrophomonas maltophilia WR-C possesses an rpf/diffusible signal factor (DSF) cell-cell communication system. It produces cis-?2-11-methyl-dodecenoic acid, a DSF, and seven structural derivatives, which require rpfF and rpfB for synthesis. Acquisition of iron from the environment is important for bacterial growth as well as the expression of virulence genes. We identified a gene homologous to fecA, which encodes a ferric citrate receptor that transports exogenous siderophore ferric citrate from the environment into the bacterial periplasm. Western blot analysis with anti-FecA-His6 antibody showed that the FecA homologue was induced in the iron-depleted medium supplemented with a low concentration of ferric citrate. Deletion of rpfF or rpfB resulted in reduced FecA expression compared to the wild type. Synthetic DSF restored FecA expression by the ?rpfF mutant to the wild-type level. Reverse transcription-PCR showed that the fecA transcript was decreased in the ?rpfF mutant compared to the wild type. These data suggest that DSF affected the level of fecA mRNA. Transposon inactivation of crp, which encodes cyclic AMP (cAMP) receptor protein (CRP) resulted in reduced FecA expression and rpfF transcript level. Putative CRP binding sites were located upstream of the rpfF promoter, indicating that the effect of CRP on FecA is through the rpf/DSF pathway and by directly controlling rpfF. We propose that CRP may serve as a checkpoint for iron uptake, protease activity, and hemolysis in response to environmental changes such as changes in concentrations of glucose, cAMP, iron, or DSF. PMID:17574998

  15. In vitro bactericidal activity of the N-terminal fragment of the frog peptide esculentin-1b (Esc 1-18) in combination with conventional antibiotics against Stenotrophomonas maltophilia.

    PubMed

    Maisetta, Giuseppantonio; Mangoni, Maria Luisa; Esin, Semih; Pichierri, Giuseppe; Capria, Anna Lisa; Brancatisano, Franca Lisa; Di Luca, Mariagrazia; Barnini, Simona; Barra, Donatella; Campa, Mario; Batoni, Giovanna

    2009-09-01

    In this study the bactericidal effect of the N-terminal fragment of the frog skin peptide esculentin-1b [Esc(1-18)] in combination with clinically used antimicrobial agents was evaluated against Stenotrophomonas maltophilia, either in standard conditions (phosphate buffer) or in the presence of human serum. A synergistic bactericidal effect was observed after a 24h incubation when combinations of Esc(1-18) and amikacin or colistin were used against clinical strains of S. maltophilia with or without resistance to these antibiotics, both in buffer and in the presence of serum. An indifferent effect was observed when the peptide was combined with levofloxacin or ceftazidime. A synergistic effect was also observed at earlier time points when the peptide was used in combination with colistin. Sequential exposure of bacterial cells to Esc(1-18) and amikacin or colistin, or vice versa, indicated that while Esc(1-18) and colistin cooperated in enhancing the bactericidal effect of their combination, when Esc(1-18) was combined with amikacin, the peptide had a major role in initiating the bactericidal effect, while amikacin was required for the subsequent effector phase. Altogether, the results obtained indicate that exposure of S. maltophilia to sub-bactericidal concentrations of Esc(1-18) increases its susceptibility to amikacin or colistin and may also render resistant strains susceptible to these antibiotics. PMID:19520127

  16. 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...

  17. 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.

  18. 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

    ...metallidurans, Variovorax paradoxus, Acidovorax sp., Sphingomonas parapaucimobilis, Stenotrophomonas maltophilia, Methylobacterium...metallidurans, Variovorax paradoxus, Acidovorax sp., Sphingomonas parapaucimobilis, Stenotrophomonas maltophilia,...

  19. 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 I? 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

  20. 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 it’s 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 334.9 mg L-1 2-PE in 12 h, 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

  1. Acrylamide biodegradation ability and plant growth-promoting properties of Variovorax boronicumulans CGMCC 4969.

    PubMed

    Liu, Zhong-Hua; Cao, Yu-Min; Zhou, Qian-Wen; Guo, Kun; Ge, Feng; Hou, Jun-Yi; Hu, Si-Yi; Yuan, Sheng; Dai, Yi-Jun

    2013-11-01

    Species of the genus Variovorax are often isolated from nitrile or amide-containing organic compound-contaminated soil. However, there have been few biological characterizations of Variovorax and their contaminant-degrading enzymes. Previously, we reported a new soil isolate, Variovorax boronicumulans CGMCC 4969, and its nitrile hydratase that transforms the neonicotinoid insecticide thiacloprid into an amide metabolite. In this study, we showed that CGMCC 4969 is able to degrade acrylamide, a neurotoxicant and carcinogen in animals, during cell growth in a mineral salt medium as well as in its resting state. Resting cells rapidly hydrolyzed 600 mg/L acrylamide to acrylic acid with a half-life of 2.5 min. In in vitro tests, CGMCC 4969 showed plant growth-promoting properties; it produced a siderophore, ammonia, hydrogen cyanide, and the phytohormone salicylic acid. Interestingly, in soil inoculated with this strain, 200 mg/L acrylamide was completely degraded in 4 days. Gene cloning and overexpression in the Escherichia coli strain Rosetta (DE3) pLysS resulted in the production of an aliphatic amidase of 345 amino acids that hydrolyzed acrylamide into acrylic acid. The amidase contained a conserved catalytic triad, Glu59, Lys 134, and Cys166, and an "MRHGDISSS" amino acid sequence at the N-terminal region. Variovorax boronicumulans CGMCC 4969, which is able to use acrylamide for cell growth and rapidly degrade acrylamide in soil, shows promising plant growth-promoting properties. As such, it has the potential to be developed into an effective Bioaugmentation strategy to promote growth of field crops in acrylamide-contaminated soil. PMID:23546990

  2. 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

  3. 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

  4. 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

  5. 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

  6. Study of the anti-sapstain fungus activity of Bacillus amyloliquefaciens CGMCC 5569 associated with Ginkgo biloba and identification of its active components.

    PubMed

    Yuan, Bo; Wang, Zhe; Qin, Sheng; Zhao, Gui-Hua; Feng, You-Jian; Wei, Li-Hui; Jiang, Ji-Hong

    2012-06-01

    An endophytic bacterium, designated strain Bacillus amyloliquefaciens CGMCC 5569 was isolated from Chinese medicinal Ginkgo biloba collected from Xuzhou, China. Both the filtrate and the ethyl acetate extract of strain CGMCC 5569 showed growth inhibition activity against the sapstain fungi Lasiodiplodia rubropurpurea, L. crassispora, and L. theobromae obviously (>65%) based on the comparison of the length of zones on the petri dish. From the ethyl acetate extract of the filtrate, the antifungal compounds were obtained as a series of lipopeptides, which including series of fengycin, surfactin and bacillomycin. It showed strong growth inhibition activity in vitro against the L. rubropurpurea, L. crassispora and L. theobromae by about 70.22%, 69.53% and 78.76%, respectively. The strong anti-sapstain fungus activity indicated that the endophytic B. amyloliquefaciens CGMCC 5569 and its bioactive components might provide an alternative bio-resource for the bio-control of sapstain. PMID:22520222

  7. Poly-?-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

    2015-09-01

    As an environmentally friendly and industrially useful biopolymer, poly-?-glutamic acid (?-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 ?-PGA, and the effects of carbon sources, ions, and chemical properties (D-/L-composition and molecular weight) on the production and flocculating activity of ?-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 ?-PGA, respectively, which was as good as the most widely used chemically synthesized flocculant in the sugarcane industry-polyacrylamide with 1 ppm. The ?-PGA produced from B. licheniformis CGMCC 2876 could be a promising alternate of chemically synthesized flocculants in the sugarcane industry. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1287-1294, 2015. PMID:26033934

  8. 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.

  9. 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

  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. Enhancement of sophorolipid production of Wickerhamiella domercqiae var. sophorolipid CGMCC 1576 by low-energy ion beam implantation.

    PubMed

    Li, Hui; Ma, Xiaojing; Shao, Lingjian; Shen, Jing; Song, Xin

    2012-06-01

    To meet the increasing demands of sophorolipids as biosurfactants and bioactive compounds, it is necessary to obtain higher and more specific sophorolipid-producing strains. One sophorolipid-producing strain, Wickerhamiella domercqiae var. sophorolipid CGMCC 1576 (Y(2A)), was mutated by low-energy nitrogen ion beam implantation. Eighteen mutants produced 20 % more sophorolipids than the wild strain, and one mutant, N3-18, produced the highest yield of sophorolipids, 104 g/l, in a shaking flask, which increased by 84.71 % than the wild strain, and further elevated to 135 g/l in a 5-l bioreactor. High performance liquid chromatography analysis showed that the composition of every sophorolipid mixture from different strains was similar, while the contents of most components from mutants were higher than that from the wild strain. Two mutants, N1-32 and N3-18, produced more acidic sophorolipid components; three lactonic sophorolipid molecules with good anticancer activities were greatly enhanced in several mutants, especially monoacetylated lactonic sophorolipid with a C18 monounsaturated fatty acid, which were enhanced by 153 and 211 % in strains N1-32 and N3-18. Low-energy nitrogen ion beam implantation was efficient for obtaining a variety of high and specific sophorolipid-producing mutants to be applied in food, cosmetic, environmental, and pharmaceutical sectors. PMID:22562550

  12. 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

  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. 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

  15. 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

  16. Purification and properties of an inducible cephalosporinase from Pseudomonas maltophilia GN12873.

    PubMed Central

    Saino, Y; Inoue, M; Mitsuhashi, S

    1984-01-01

    An inducible cephalosporinase was purified from Pseudomonas maltophilia GN12873. The pI was 8.4, and the molecular weight was ca. 56,000 by gel filtration or 27,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, suggesting that this enzyme had two subunits. The optimal pH and optimal temperature were 7.5 and 45 degrees C, respectively. Enzyme activity was inhibited by clavulanic acid, sulbactam, cephamycin derivatives, carbapenem antibiotics, iodine, HgCl2, and p-chloromercuribenzoate. The enzyme showed a broad substrate profile, hydrolyzing cephaloridine, cefazolin, cefsulodin, penicillin G, ceftizoxime, and ampicillin at a high rate. PMID:6609682

  17. Engineering chlorpyrifos-degrading Stenotrophomonas sp. YC-1 for heavy metal accumulation and enhanced chlorpyrifos degradation.

    PubMed

    Liu, Ruihua; Jiang, Hong; Xu, Ping; Qiao, Chuanling; Zhou, Qixing; Yang, Chao

    2014-11-01

    Many ecosystems are currently co-contaminated with pesticides and heavy metals, such as chlorpyrifos and cadmium. A promising strategy to remediate mixed chlorpyrifos-cadmium-contaminated sites is the use of chlorpyrifos-degrading bacteria endowed with cadmium removal capabilities. In this work, a gene coding for synthetic phytochelatins (EC20) with high cadmium-binding capacity was introduced into a chlorpyrifos-degrading bacterium, Stenotrophomonas sp. YC-1, resulting in an engineered strain with both cadmium accumulation and chlorpyrifos degradation capabilities. To improve the cadmium-binding efficiency of whole cells, EC20 was displayed on the cell surface of Stenotrophomonas sp. YC-1 using the truncated ice nucleation protein (INPNC) anchor. The surface localization of the INPNC-EC20 fusion protein was demonstrated by cell fractionation, Western blot analysis, and immunofluorescence microscopy. Expression of EC20 on the cell surface not only improved cadmium binding, but also alleviated the cellular toxicity of cadmium. As expected, the chlorpyrifos degradation rate was reduced in the presence of cadmium for cells without EC20 expression. However, expression of EC20 (higher cadmium accumulation) completely restored the level of chlorpyrifos degradation. These results demonstrated that EC20 expression not only enhanced cadmium accumulation, but also reduced the toxic effect of cadmium on chlorpyrifos degradation. PMID:25151179

  18. Design, synthesis, and SAR of novel carbapenem antibiotics with high stability to Xanthomonas maltophilia oxyiminocephalosporinase type II.

    PubMed

    Hakimelahi, G H; Moosavi-Movahedi, A A; Tsay, S C; Tsai, F Y; Wright, J D; Dudev, T; Hakimelahi, S; Lim, C

    2000-10-01

    Racemic cis-6-(phenylacetamido)carbapenem (21), 2-hydroxycarbonyl-cis-6-(phenylacetamido)carbapenem (22), 2-methoxycarbonyl-cis-6-(phenylacetamido)carbapenem (30), 2-methoxycarbomethyl-cis-6-(phenylacetamido)carbapenem (33), 2-hydroxyethyl-cis-6-(phenylacetamido)carbapenem (34), and 2-acetoxyethyl-cis-6-(phenylacetamido)carbapenem (35) were synthesized. Formation of the carbapenem nuclei in 21, 22, and 30 involved dehydrophosphonation of the corresponding 2-diphenylphosphono-6-(phenylacetamido)carbapenam precursors 14, 15, and 28 using trimethylsilyl triflate and 1,8-diazabicyclo[5.4.0]undec-7-ene in THF. Syntheses of carbapenems 33-35 involved a Wittig reaction of carbapenam 14 with methyl glyoxylate in the presence of lithium 2,2,6,6-tetramethylpiperidine in THF. For the antibacterial activities against Staphylococcus aureus FDA 209P, S. aureus 95, Escherichia coli ATCC 39188, Klebsiellapneumoniae NCTC 418, Pseudomonas aeruginosa 1101-75, and P. aeruginosa 18S-H, carbapenems (+/-)-21, (+/-)-22, (+/-)-30, and (+/-)-33-35 were found comparable with imipenem ((+)-3), yet they were notably more potent than (+)-3 against Xanthomonas maltophilia GN 12873. On the other hand, unlike (+)-3, carbapenems (+/-)-21, (+/-)-22, (+/-)-30, and (+/-)-33-35 were stable to X. maltophilia oxyiminocephalosporinase type II. Their beta-lactamase inhibitory properties, however, were found to be more comparable with those of penicillin G ((+)-4) than to those of imipenem ((+)-3). A combination of imipenem ((+)-3) with (+/-)-21, (+/-)-22, (+/-)-30, and (+/-)-33-35 resulted in synergistic antibacterial activity against X. maltophilia GN 12873. Results from the biological tests were correlated with the distribution of the electron density at C(2)=C(3) of carbapenems upon reaction with transpeptidases or beta-lactamases. PMID:11020277

  19. 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.

  20. 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

  1. 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

  2. ?-Dodecelactone production from safflower oil via 10-hydroxy-12(Z)-octadecenoic acid intermediate by whole cells of Candida boidinii and Stenotrophomonas nitritireducens.

    PubMed

    Jo, Ye-Seul; An, Jung-Ung; Oh, Deok-Kun

    2014-07-16

    Candida boidinii was selected as a ?-dodecelactone producer because of the highest production of ?-dodecelactone from 10-hydroxy-12(Z)-octadecenoic acid among the 11 yeast strains tested. Under the reaction conditions of pH 5.5 and 25 °C with 5 g/L 10-hydroxy-12(Z)-octadecenoic acid and 30 g/L cells, whole C. boidinii cells produced 2.1 g/L ?-dodecelactone from 5 g/L 10-hydroxy-12(Z)-octadecenoic acid after 6 h, with a conversion yield of 64% (mol/mol) and a volumetric productivity of 350 mg/L/h. The production of ?-dodecelactone from safflower oil was performed by lipase hydrolysis reaction and two-step whole-cell biotransformation using Stenotrophomonas nitritireducens and C. boidinii. ?-Dodecelactone at 1.88 g/L was produced from 7.5 g/L safflower oil via 5 g/L 10-hydroxy-12(Z)-octadecenoic acid intermediate by these reactions after 8 h of reaction time, with a volumetric productivity of 235 mg/L/h and a conversion yield of 25% (w/w). To the best of the authors' knowledge, this is the highest volumetric productivity and conversion yield reported to date for the production of ?-lactone from natural oils. PMID:24967938

  3. Biodegradation of fenvalerate and 3-phenoxybenzoic acid by a novel Stenotrophomonas sp. strain ZS-S-01 and its use in bioremediation of contaminated soils.

    PubMed

    Chen, Shaohua; Yang, Liu; Hu, Meiying; Liu, Jingjing

    2011-04-01

    A bacterial strain ZS-S-01, newly isolated from activated sludge, could effectively degrade fenvalerate and its hydrolysis product 3-phenoxybenzoic acid (3-PBA). Based on the morphology, physiological biochemical characteristics, and 16 S rDNA sequence, strain ZS-S-01 was identified as Stenotrophomonas sp. Strain ZS-S-01 could also degrade and utilize deltamethrin, beta-cypermethrin, beta-cyfluthrin, and cyhalothrin as substrates for growth. Strain ZS-S-01 was capable of degrading fenvalerate rapidly without a lag phase over a wide range of pH and temperature, even in the presence of other carbon sources, and metabolized it to yield 3-PBA, then completely degraded it. No persistent accumulative product was detected by HPLC and GC/MS analysis. Studies on biodegradation in various soils showed that strain ZS-S-01 demonstrated efficient degradation of fenvalerate and 3-PBA (both 50 mg·kg(-1)) with a rate constant of 0.1418-0.3073 d(-1), and half-lives ranged from 2.3 to 4.9 days. Compared with the controls, the half-lives for fenvalerate and 3-PBA reduced by 16.9-156.3 days. These results highlight strain ZS-S-01 may have potential for use in bioremediation of pyrethroid-contaminated environment. PMID:21184062

  4. 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

  5. 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

    Vinuesa, Pablo; 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

  6. Levofloxacin and Ciprofloxacin In Vitro Activities against 4,003 Clinical Bacterial Isolates Collected in 24 Italian Laboratories

    PubMed Central

    Gesu, Giovanni Pietro; Marchetti, Federico; Piccoli, Laura; Cavallero, Annalisa

    2003-01-01

    Levofloxacin showed comparable in vitro susceptibility to ciprofloxacin among Enterobacteriaceae, Pseudomonas aeruginosa, enterococci, and Staphylococcus aureus, while greater susceptibility was observed in Stenotrophomonas maltophilia and Staphylococcus epidermidis, mainly when oxacillin resistant. The susceptibility of Streptococcus pneumoniae to levofloxacin reached 99%. PMID:12543701

  7. 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% (53.04g/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

  8. Gut-associated bacteria throughout the life cycle of the bark beetle Dendroctonus rhizophagus Thomas and Bright (Curculionidae: Scolytinae) and their cellulolytic activities.

    PubMed

    Morales-Jiménez, Jesús; Zúñiga, Gerardo; Ramírez-Saad, Hugo C; Hernández-Rodríguez, César

    2012-07-01

    Dendroctonus rhizophagus Thomas and Bright (Curculionidae: Scolytinae) is an endemic economically important insect of the Sierra Madre Occidental in Mexico. This bark beetle has an atypical behavior within the genus because just one beetle couple colonizes and kills seedlings and young trees of 11 pine species. In this work, the bacteria associated with the Dendroctonus rhizophagus gut were analyzed by culture-dependent and culture-independent methods. Analysis of 16S rRNA sequences amplified directly from isolates of gut bacteria suggests that the bacterial community associated with Dendroctonus rhizophagus, like that of other Dendroctonus spp. and Ips pini, is limited in number. Nine bacterial genera of ?-Proteobacteria and Actinobacteria classes were detected in the gut of Dendroctonus rhizophagus. Stenotrophomonas and Rahnella genera were the most frequently found bacteria from Dendroctonus rhizophagus gut throughout their life cycle. Stenotrophomonas maltophilia, Ponticoccus gilvus, and Kocuria marina showed cellulolytic activity in vitro. Stenotrophomonas maltophilia, Rahnella aquatilis, Raoultella terrigena, Ponticoccus gilvus, and Kocuria marina associated with larvae or adults of Dendroctonus rhizophagus could be implicated in nitrogen fixation and cellulose breakdown, important roles associated to insect development and fitness, especially under the particularly difficult life conditions of this beetle. PMID:22234511

  9. 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.

  10. 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

  11. Isolation and characterization of alkane degrading bacteria from petroleum reservoir waste water in Iran (Kerman and Tehran provenances).

    PubMed

    Hassanshahian, Mehdi; Ahmadinejad, Mohammad; Tebyanian, Hamid; Kariminik, Ashraf

    2013-08-15

    Petroleum products spill and leakage have become two major environmental challenges in Iran. Sampling was performed in the petroleum reservoir waste water of Tehran and Kerman Provinces of Iran. Alkane degrading bacteria were isolated by enrichment in a Bushnel-Hass medium, with hexadecane as sole source of carbon and energy. The isolated strains were identified by amplification of 16S rDNA gene and sequencing. Specific primers were used for identification of alkane hydroxylase gene. Fifteen alkane degrading bacteria were isolated and 8 strains were selected as powerful degradative bacteria. These 8 strains relate to Rhodococcus jostii, Stenotrophomonas maltophilia, Achromobacter piechaudii, Tsukamurella tyrosinosolvens, Pseudomonas fluorescens, Rhodococcus erythropolis, Stenotrophomonas maltophilia, Pseudomonas aeruginosa genera. The optimum concentration of hexadecane that allowed high growth was 2.5%. Gas chromatography results show that all strains can degrade approximately half of hexadecane in one week of incubation. All of the strains have alkane hydroxylase gene which are important for biodegradation. As a result, this study indicates that there is a high diversity of degradative bacteria in petroleum reservoir waste water in Iran. PMID:23790464

  12. 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

  13. 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

  14. 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

  15. 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

  16. Bacterial Pathogens of Ventilator Associated Pneumonia in a Tertiary Referral Hospital

    PubMed Central

    Chi, Su Young; Kim, Tae Ok; Park, Chan Woo; Yu, Jin Yeong; Lee, Boram; Lee, Ho Sung; Kim, Yu Il; Lim, Sung Chul

    2012-01-01

    Background This study evaluates the bacterial pathogens of Ventilator-associated pneumonia (VAP) in a tertiary referral hospital. Methods A total of 109 bacterial pathogens from 91 adult patients with VAP, who were admitted to the medical intensive care unit from January 2008 to December 2009, were examined. Clinical characteristics, bacterial pathogens, and resistance profiles were analyzed. Results Staphylococcus aureus (44%) was the most frequently isolated. Acinetobacter baumanii (30%), Pseudomonas aeruginosa (12%), Stenotrophomonas maltophilia (7%), Klebsiella pneumoniae (6%), and Serratia marcescens (2%) were isolated from the transtracheal aspirates or bronchoalveolar lavage in patients with VAP. There was no significant difference of bacterial pathogens between early and late onset VAP. All isolated S. aureus were methicillin resistant S. aureus; the imipenem resistance rate of A. baumanii was 69%. Conclusion The two most frequent pathogens of VAP were S. aureus and A. baumanii. There were no pathogenic differences between early and late onset VAP. PMID:23101022

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

    PubMed

    Szulc, Alicja; Ambro?ewicz, Damian; Sydow, Mateusz; ?awniczak, ?ukasz; Piotrowska-Cyplik, Agnieszka; Marecik, Roman; Chrzanowski, ?ukasz

    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

  18. 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 ?g/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

  19. 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

  20. 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

  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. Low Rates of Pseudomonas aeruginosa Misidentification in Isolates from Cystic Fibrosis Patients?

    PubMed Central

    Kidd, Timothy J.; Ramsay, Kay A.; Hu, Honghua; Bye, Peter T. P.; Elkins, Mark R.; Grimwood, Keith; Harbour, Colin; Marks, Guy B.; Nissen, Michael D.; Robinson, Philip J.; Rose, Barbara R.; Sloots, Theo P.; Wainwright, Claire E.; Bell, Scott C.

    2009-01-01

    Pseudomonas aeruginosa is an important cause of pulmonary infection in cystic fibrosis (CF). Its correct identification ensures effective patient management and infection control strategies. However, little is known about how often CF sputum isolates are falsely identified as P. aeruginosa. We used P. aeruginosa-specific duplex real-time PCR assays to determine if 2,267 P. aeruginosa sputum isolates from 561 CF patients were correctly identified by 17 Australian clinical microbiology laboratories. Misidentified isolates underwent further phenotypic tests, amplified rRNA gene restriction analysis, and partial 16S rRNA gene sequence analysis. Participating laboratories were surveyed on how they identified P. aeruginosa from CF sputum. Overall, 2,214 (97.7%) isolates from 531 (94.7%) CF patients were correctly identified as P. aeruginosa. Further testing with the API 20NE kit correctly identified only 34 (59%) of the misidentified isolates. Twelve (40%) patients had previously grown the misidentified species in their sputum. Achromobacter xylosoxidans (n = 21), Stenotrophomonas maltophilia (n = 15), and Inquilinus limosus (n = 4) were the species most commonly misidentified as P. aeruginosa. Overall, there were very low rates of P. aeruginosa misidentification among isolates from a broad cross section of Australian CF patients. Additional improvements are possible by undertaking a culture history review, noting colonial morphology, and performing stringent oxidase, DNase, and colistin susceptibility testing for all presumptive P. aeruginosa isolates. Isolates exhibiting atypical phenotypic features should be evaluated further by additional phenotypic or genotypic identification techniques. PMID:19261796

  4. 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 ?MexXY (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

  5. 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

  6. 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

  7. Mineralization and co-metabolic degradation of phenoxyalkanoic acid herbicides by a pure bacterial culture isolated from an aquifer.

    PubMed

    Mai, P; Jacobsen, O S; Aamand, J

    2001-08-01

    A mecoprop [(+/-)-2-(4-chloro-2-methylphenoxy)propionic acid; MCPP]-degrading bacterium identified as Stenotrophomonas maltophilia PM was isolated from a Danish aquifer. Besides mecoprop, the bacterium was also able to degrade MCPA [(4-chloro-2-methylphenoxy)acetic acid)], MCPB [(4-chloro-2-methylphenoxy)butyric acid], 4-CPA [(4-chlorophenoxy)acetic acid], 2, 4-D [(2, 4-dichlorophenoxy)acetic acid], 2, 4-DP [(+/-)-2-(2, 4-dichlorophenoxy)propionic acid] and 2, 4-DB [(2, 4-dichlorophenoxy)butyric acid]. The bacterium was able to grow using these individual phenoxyalkanoic acids as the sole source of carbon and energy. In addition, it was able to co-metabolically degrade the phenoxyalkanoic acid 2, 4, 5-T [(2, 4, 5-trichlorophenoxy)acetic acid)] in the presence of mecoprop. At high 2, 4, 5-T concentrations (100 and 52 mg/l), however, only partial degradation of both mecoprop and 2, 4, 5-T was obtained, thus indicating the production of toxic metabolites. Bacterial yields were highest when grown on the monochlorinated phenoxyalkanoic acids as compared to the dichlorinated analogues, an exception being growth on 4CPA, which resulted in the lowest yield at all. Using [ring-U-14C]-labeled herbicides it was shown that the lower yield on 2, 4-D than on mecoprop was accompanied by greater CO2 generation, thus indicating that less energy is available from the complete oxidation of the dichlorinated phenoxyalkanoic acids than the monochlorinated analogues. PMID:11549024

  8. 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

  9. 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

  10. 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

  11. Evaluation of pyrrolidonyl arylamidase for the identification of nonfermenting Gram-negative rods.

    PubMed

    Bombicino, Karina A; Almuzara, Marisa N; Famiglietti, Angela M R; Vay, Carlos

    2007-01-01

    To evaluate the activity of pyrrolidonyl arylamidase (PYR) for the differentiation and identification of nonfermenting gram negative rods (NFGNR), 293 isolates were tested. A 24 h culture of each test organism was prepared. From this a 108-109 cfu/mL suspension was added to 0.25 mL of sterile physiologic solution. A PYR disk was then added and the test was incubated for 30 minutes at 35-37 degrees C, at environmental atmosphere. Reading was done by adding 1 drop of cinnamaldehyde reagent. Strains of Acinetobacter baumannii, Acinetobacter haemolyticus, Alcaligenes faecalis, Bergeyella zoohelcum, Bordetella bronchiseptica, Bordetella hinzii, Brevundimonas diminuta, Brevundimonas vesicularis, Brucella ovis, Brucella spp., Brucella suis, Burkholderia cepacia complex, Moraxella catarrhalis, Moraxella lacunata, Moraxella nonliquefaciens, Moraxella osloensis, Oligella ureolytica, Pseudomonas alcaligenes, Pseudomonas mendocina, Pseudomonas pseudoalcaligenes, Pseudomonas putida, Pseudomonas stutzeri, Pseudomonas Vb3, Psychrobacter phenylpyruvicus, and Stenotrophomonas maltophilia were PYR negative. On the other hand Achromobacter piechaudii, Achromobacter denitrificans, Achromobacter xylosoxidans, Burkholderia gladioli, Chryseobacterium gleum-indologenes, Comamonas testosroni, Cupriavidus pauculus, Delftia acidovorans, Elizabethkingia meningoseptica, Myroides spp., Ochrobactrum anthropi, Pseudomonas oryzihabitans, Ralstonia pickettii, Rhizobium radiobacter, Shewanella spp., Sphingobacterium multivorum, Sphingobacterium spiritivorum, and Weeksella virosa were PYR positive. Finally, Acinetobacter lwoffii, Pseudomonas aeruginosa, Pseudomonas fluorescens, Roseomonas spp., and Sphingomonas paucimobilis-parapaucimobilis were PYR variable. PYR testing should be considered as a useful tool to facilitate the identification of NFGNR. PMID:16822636

  12. 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

  13. 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 ?-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

  14. Identification and Antimicrobial Susceptibility of Alcaligenes xylosoxidans Isolated from Patients with Cystic Fibrosis

    PubMed Central

    Saiman, Lisa; Chen, Yunhua; Tabibi, Setareh; San Gabriel, Pablo; Zhou, Juyan; Liu, Zhenling; Lai, Lena; Whittier, Susan

    2001-01-01

    In the past decade, potential pathogens, including Alcaligenes species, have been increasingly recovered from cystic fibrosis (CF) patients. Accurate identification of multiply antibiotic-resistant gram-negative bacilli is critical to understanding the epidemiology and clinical implications of emerging pathogens in CF. We examined the frequency of correct identification of Alcaligenes spp. by microbiology laboratories affiliated with American CF patient care centers. Selective media, an exotoxin A probe for Pseudomonas aeruginosa, and a commercial identification assay, API 20 NE, were used for identification. The activity of antimicrobial agents against these clinical isolates was determined. A total of 106 strains from 78 patients from 49 CF centers in 22 states were studied. Most (89%) were correctly identified by the referring laboratories as Alcaligenes xylosoxidans. However, 12 (11%) strains were misidentified; these were found to be P. aeruginosa (n = 10), Stenotrophomonas maltophilia (n = 1), and Burkholderia cepacia (n = 1). Minocycline, imipenem, meropenem, piperacillin, and piperacillin-tazobactam were the most active since 51, 59, 51, 50, and 55% of strains, respectively, were inhibited. High concentrations of colistin (100 and 200 ?g/ml) inhibited 92% of strains. Chloramphenicol paired with minocycline and ciprofloxacin paired with either imipenem or meropenem were the most active combinations and inhibited 40 and 32%, respectively, of strains. Selective media and biochemical identification proved to be useful strategies for distinguishing A. xylosoxidans from other CF pathogens. Standards for processing CF specimens should be developed, and the optimal method for antimicrobial susceptibility testing of A. xylosoxidans should be determined. PMID:11682511

  15. 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

  16. Changes in gram negative microorganisms’ resistance pattern during 4?years period in a referral teaching hospital; a surveillance study

    PubMed Central

    2012-01-01

    Background and purpose Surveillance studies evaluating antimicrobial susceptibilities are of great value in preventing the spread of resistant pathogens by elucidating the trend of resistance in commonly used antibiotics and as a consequence providing information for prescribing the most appropriate agent. This study is a longitudinal antimicrobial resistance surveillance study designed to evaluate the trend in antimicrobial resistance to gram negative microorganisms from 2007 to 2010. Method During a four-year period (2007–2010) isolates derived from all patients admitted to infectious diseases ward of Imam Khomeini Hospital, the major referral center for infectious disease in Iran with the highest admission rates, were evaluated. Based on disk diffusion method and zone of inhibition size, the microorganism was regarded as to be sensitive, resistant or has intermediate susceptibility to the antimicrobial agents. Results The widest spread Gram-negative microorganism in all of isolates taken together in our study was E.coli (30%) followed by Stenotrophomonas maltophilia in 28.6% and Enterobacter spp. in 11.9%, respectively. The susceptibility to amikacin, imipenem, piperacillin/tazobactam, and nitrofurantoin was equal or above 50% for all microorganisms over four years. However, the susceptibility to ampicillin, ampicillin/sulbactam, cefotaxim, and ceftriaxone was less than 50% in derived isolates during the study period. Conclusion In conclusion, the finding of the present study revealed that resistance rate to common antimicrobial agents in Iran is growing and isolates were susceptible mostly to broad-spectrum antibiotics including imipenem and piperacillin/tazobactam. PMID:23351308

  17. 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

  18. 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.

  19. 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

  20. Multi-channel microfluidic biosensor platform applied for online monitoring and screening of biofilm formation and activity.

    PubMed

    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

  1. 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

  2. Point-of-use water filtration reduces healthcare-associated infections in bone marrow transplant recipients.

    PubMed

    Cervia, J S; Farber, B; Armellino, D; Klocke, J; Bayer, R-L; McAlister, M; Stanchfield, I; Canonica, F P; Ortolano, G A

    2010-06-01

    Outbreaks of infection with gram-negative bacteria (GNB) have been linked to hospital water. We sought to determine whether point-of-use (POU) water filtration might result in decreased risk of infection in hospitalized bone marrow transplant (BMT) recipients in the absence of any recognized outbreak. Unfiltered water was sampled from taps in the BMT unit of a major US teaching hospital, and cultured at a reference laboratory. POU bacterial-retentive filters (0.2 mum) were installed throughout the unit, and replaced every 14 days. Infection rates were tracked over a 9-month period, and compared with rates for a 16-month period before POU filtration. Unfiltered water samples from 50% (2 of 4) outlets sampled grew P. aeruginosa (2 of 4) and Stenotrophomonas maltophilia (1 of 4). Clinical infection rates in the unit were significantly reduced from 1.4 total and 0.4 GNB infections per 100 patient days in the period before POU filtration to 0.18 total and 0.09 GNB infections per 100 patient days (P=0.0068 and 0.0431, respectively) in the 9-month period for which filters were in place. Infections during the POU filtration period were due to non-waterborne organisms. Point-of-use (POU) water filtration may significantly reduce infection rates in BMT recipients in the absence of any recognized outbreak. PMID:19781018

  3. Physiological traits of the symbiotic bacterium Teredinibacter turnerae isolated from the mangrove shipworm Neoteredo reynei

    PubMed Central

    2009-01-01

    Nutrition in the Teredinidae family of wood-boring mollusks is sustained by cellulolytic/nitrogen fixing symbiotic bacteria of the Teredinibacter clade. The mangrove Teredinidae Neoteredo reynei is popularly used in the treatment of infectious diseases in the north of Brazil. In the present work, the symbionts of N. reynei, which are strictly confined to the host's gills, were conclusively identified as Teredinibacter turnerae. Symbiont variants obtained in vitro were able to grow using casein as the sole carbon/nitrogen source and under reduced concentrations of NaCl. Furthermore, cellulose consumption in T. turnerae was clearly reduced under low salt concentrations. As a point of interest, we hereby report first hand that T. turnerae in fact exerts antibiotic activity. Furthermore, this activity was also affected by NaCl concentration. Finally, T. turnerae was able to inhibit the growth of Gram-negative and Gram-positive bacteria, this including strains of Sphingomonas sp., Stenotrophomonas maltophilia, Bacillus cereus and Staphylococcus sciuri. Our findings introduce new points of view on the ecology of T. turnerae, and suggest new biotechnological applications for this marine bacterium. PMID:21637522

  4. Stent hypersensitivity and infection in sinus cavities

    PubMed Central

    Soufras, George D.; Hahalis, George

    2013-01-01

    Persistent mucosal inflammation, granulation tissue formation, hypersensitivity, and multifactorial infection are newly described complications of retained drug-eluting stents from endoscopic sinus surgery for refractory rhinosinusitis. In an important report published in Allergy and Rhinology, a 45-year-old male patient suffering from recalcitrant chronic rhinosinusitis underwent functional endoscopic sinus surgery and was found, for the first time, to have steroid-eluting catheters that were inadvertently left in the ethmoid and frontal sinuses. The retained catheters had caused persistent mucosal inflammation and formation of granulation tissue denoting hypersensitivity reaction. These consequences had induced perpetuation of symptoms of chronic rhinosinusitis. Meticulous removal of the retained stents with the nitinol wings from inflamed tissues of the frontal, ethmoidal, and sphenoethmoidal recesses in which they were completely imbedded was successfully performed without polypoid regrowth. Cultures of specimens taken from both left and right stents showed heavy growth of Stenotrophomonas maltophilia and moderate growth of Klebsiella oxytoca, coagulase negative Staphylococcus, and beta-hemolytic Streptococcus anginosus. Fungal infection was not detected. The current knowledge and experience regarding stent hypersensitivity and infection in relation with the use of stents in sinus cavities is reviewed. PMID:24498522

  5. Cleavage of influenza A virus H1 hemagglutinin by swine respiratory bacterial proteases.

    PubMed Central

    Callan, R J; Hartmann, F A; West, S E; Hinshaw, V S

    1997-01-01

    Cleavage of influenza A virus hemagglutinin (HA) is required for expression of fusion activity and virus entry into cells. Extracellular proteases are responsible for the proteolytic cleavage activation of avirulent avian and mammalian influenza viruses and contribute to pathogenicity and tissue tropism. The relative contributions of host and microbial proteases to cleavage activation in natural infection remain to be established. We examined 23 respiratory bacterial pathogens and 150 aerobic bacterial isolates cultured from the nasal cavities of pigs for proteolytic activity. No evidence of secreted proteases was found for the bacterial pathogens, including Haemophilus parasuis, Pasteurella multocida, Actinobacillus pleuropneumoniae, Bordetella bronchiseptica, and Streptococcus suis. Proteolytic bacteria were isolated from 7 of 11 swine nasal samples and included Staphylococcus chromogenes, Staphylococcus hyicus, Aeromonas caviae, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Enterococcus sp. Only P. aeruginosa secreted a protease, elastase, that cleaved influenza virus HA. However, compared to trypsin, the site of cleavage by elastase was shifted one amino acid in the carboxy-terminal direction and resulted in inactivation of the virus. Under the conditions of this study, we identified several bacterial isolates from the respiratory tracts of pigs that secrete proteases in vitro. However, none of these proteolytic isolates demonstrated direct cleavage activation of influenza virus HA. PMID:9311838

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

    PubMed

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

    2011-09-01

    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

  7. 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 LC?? (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 L? (3?) 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. Nitrate treatment effects on bacterial community biofilm formed on carbon steel in produced water stirred tank bioreactor.

    PubMed

    Marques, Joana Montezano; de Almeida, Fernando Pereira; Lins, Ulysses; Seldin, Lucy; Korenblum, Elisa

    2012-06-01

    To better understand the impact of nitrate in Brazilian oil reservoirs under souring processes and corrosion, the goal of this study was to analyse the effect of nitrate on bacterial biofilms formed on carbon steel coupons using reactors containing produced water from a Brazilian oil platform. Three independent experiments were carried out (E1, E2 and E3) using the same experimental conditions and different incubation times (5, 45 and 80 days, respectively). In every experiment, two biofilm-reactors were operated: one was treated with continuous nitrate flow (N reactor), and the other was a control reactor without nitrate (C reactor). A Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis approach using the 16S rRNA gene was performed to compare the bacterial groups involved in biofilm formation in the N and C reactors. DGGE profiles showed remarkable changes in community structure only in experiments E2 and E3. Five bands extracted from the gel that represented the predominant bacterial groups were identified as Bacillus aquimaris, B. licheniformis, Marinobacter sp., Stenotrophomonas maltophilia and Thioclava sp. A reduction in the sulfate-reducing bacteria (SRB) most probable number counts was observed only during the longer nitrate treatment (E3). Carbon steel coupons used for biofilm formation had a slightly higher weight loss in N reactors in all experiments. When the coupon surfaces were analysed by scanning electron microscopy, an increase in corrosion was observed in the N reactors compared with the C reactors. In conclusion, nitrate reduced the viable SRB counts. Nevertheless, the nitrate dosing increased the pitting of coupons. PMID:22806109

  14. 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.

  15. Antibacterial activity of BMS-180680, a new catechol-containing monobactam.

    PubMed Central

    Fung-Tomc, J; Bush, K; Minassian, B; Kolek, B; Flamm, R; Gradelski, E; Bonner, D

    1997-01-01

    The in vitro activities of a new catechol-containing monobactam, BMS-180680 (SQ 84,100), were compared to those of aztreonam, ceftazidime, imipenem, piperacillin-tazobactam, ciprofloxacin, amikacin, and trimethoprim-sulfamethoxazole. BMS-180680 was often the most active compound against many species of the family Enterobacteriaceae, with MICs at which 90% of the isolates were inhibited (MIC90s) of < or = 0.5 microg/ml for Escherichia coli, Klebsiella spp., Citrobacter diversus, Enterobacter aerogenes, Serratia marcescens, Proteus spp., and Providencia spp. BMS-180680 had moderate activities (MIC90s of 2 to 8 microg/ml) against Citrobacter freundii, Morganella morganii, Shigella spp., and non-E. aerogenes Enterobacter spp. BMS-180680 was the only antibiotic evaluated that was active against >90% of the Pseudomonas aeruginosa (MIC90, 0.25 microg/ml), Burkholderia cepacia, and Stenotrophomonas maltophilia (MIC90s, 1 microg/ml) strains tested. BMS-180680 was inactive against most strains of Pseudomonas fluorescens, Pseudomonas stutzeri, Pseudomonas diminuta, and Burkholderia pickettii. BMS-180680 was moderately active (MIC90s of 4 to 8 microg/ml) against Alcaligenes spp. and Acinetobacter lwoffii and less active (MIC90, 16 microg/ml) against Acinetobacter calcoaceticus-Acinetobacter baumanii complex. BMS-180680 lacked activity against gram-positive bacteria and anaerobic bacteria. Both tonB and cir fiu double mutants of E. coli had greatly decreased susceptibility to BMS-180680. Of the TEM, PSE, and chromosomal-encoded beta-lactamases tested, only the K1 enzyme hydrolyzed BMS-180680 to any measurable extent. Like aztreonam, BMS-180680 bound preferentially to penicillin-binding protein 3. The MICs of BMS-180680 were not influenced by the presence of hematin or 5% sheep blood in the test medium or with incubation in an atmosphere containing 5% CO2. BMS-180680 MICs obtained under strict anaerobic conditions were significantly higher than those obtained in ambient air. PMID:9145861

  16. Antibacterial activity of BMS-180680, a new catechol-containing monobactam.

    PubMed

    Fung-Tomc, J; Bush, K; Minassian, B; Kolek, B; Flamm, R; Gradelski, E; Bonner, D

    1997-05-01

    The in vitro activities of a new catechol-containing monobactam, BMS-180680 (SQ 84,100), were compared to those of aztreonam, ceftazidime, imipenem, piperacillin-tazobactam, ciprofloxacin, amikacin, and trimethoprim-sulfamethoxazole. BMS-180680 was often the most active compound against many species of the family Enterobacteriaceae, with MICs at which 90% of the isolates were inhibited (MIC90s) of < or = 0.5 microg/ml for Escherichia coli, Klebsiella spp., Citrobacter diversus, Enterobacter aerogenes, Serratia marcescens, Proteus spp., and Providencia spp. BMS-180680 had moderate activities (MIC90s of 2 to 8 microg/ml) against Citrobacter freundii, Morganella morganii, Shigella spp., and non-E. aerogenes Enterobacter spp. BMS-180680 was the only antibiotic evaluated that was active against >90% of the Pseudomonas aeruginosa (MIC90, 0.25 microg/ml), Burkholderia cepacia, and Stenotrophomonas maltophilia (MIC90s, 1 microg/ml) strains tested. BMS-180680 was inactive against most strains of Pseudomonas fluorescens, Pseudomonas stutzeri, Pseudomonas diminuta, and Burkholderia pickettii. BMS-180680 was moderately active (MIC90s of 4 to 8 microg/ml) against Alcaligenes spp. and Acinetobacter lwoffii and less active (MIC90, 16 microg/ml) against Acinetobacter calcoaceticus-Acinetobacter baumanii complex. BMS-180680 lacked activity against gram-positive bacteria and anaerobic bacteria. Both tonB and cir fiu double mutants of E. coli had greatly decreased susceptibility to BMS-180680. Of the TEM, PSE, and chromosomal-encoded beta-lactamases tested, only the K1 enzyme hydrolyzed BMS-180680 to any measurable extent. Like aztreonam, BMS-180680 bound preferentially to penicillin-binding protein 3. The MICs of BMS-180680 were not influenced by the presence of hematin or 5% sheep blood in the test medium or with incubation in an atmosphere containing 5% CO2. BMS-180680 MICs obtained under strict anaerobic conditions were significantly higher than those obtained in ambient air. PMID:9145861

  17. 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 ?-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 ?g/ml), and only one MRSA isolate (MIC90, 0.5 ?g/ml) and three VRE isolates (MIC90, 0.125 ?g/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 ?g/ml) and 96.32% for ESBL-producing K. pneumoniae (MIC90, 2 ?g/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 ?g/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

  18. Mutations of an NAD(P)H-dependent flavoprotein monooxygenase that influence cofactor promiscuity and enantioselectivity.

    PubMed

    Jensen, Chantel N; Ali, Sohail T; Allen, Michael J; Grogan, Gideon

    2013-01-01

    The flavoprotein monooxygenase (FPMO) from Stenotrophomonas maltophilia (SMFMO, Uniprot: B2FLR2) catalyses the asymmetric oxidation of thioethers and is unusual amongst FPMOs in its ability to use the non-phosphorylated cofactor NADH, as well as NADPH, for the reduction of the FAD coenzyme. In order to explore the basis for cofactor promiscuity, structure-guided mutation of two residues in the cofactor binding site, Gln193 and His194, in SMFMO were performed in an attempt to imitate the cofactor binding site of the NADPH-dependent FMO from Methylophaga aminisulfidivorans sp. SK1 (mFMO), in which structurally homologous residues Arg234 and Thr235 bind the NADPH 2'-ribose phosphate. Mutation of His194 to threonine proved most significant, with a switch in specificity from NADH to NADPH [(k cat/K m NADH)/k cat/K m NADPH) from 1.5:1 to 1:3.5, mostly as a result of a reduced K m for NADPH of approximately sevenfold in the His194Thr mutant. The structure of the Gln193Arg/His194Thr mutant revealed no substantial changes in the backbone of the enzyme or orientation of side chains resulting from mutation. Mutation of Phe52, in the vicinity of FAD, and which in mFMO is an asparagine thought to be responsible for flavin hydroperoxide stabilisation, is, in SMFMO, a determinant of enantioselectivity in sulfoxidation. Mutation of Phe52 to valine resulted in a mutant that transformed para-tolyl methyl sulfide into the (S)-sulfoxide with 32% e.e., compared to 25% (R)- for the wild type. These results shed further light both on the cofactor specificity of FPMOs, and their determinants of enantioselectivity, with a view to informing engineering studies of FPMOs in the future. PMID:24251114

  19. Mutations of an NAD(P)H-dependent flavoprotein monooxygenase that influence cofactor promiscuity and enantioselectivity?

    PubMed Central

    Jensen, Chantel N.; Ali, Sohail T.; Allen, Michael J.; Grogan, Gideon

    2013-01-01

    The flavoprotein monooxygenase (FPMO) from Stenotrophomonas maltophilia (SMFMO, Uniprot: B2FLR2) catalyses the asymmetric oxidation of thioethers and is unusual amongst FPMOs in its ability to use the non-phosphorylated cofactor NADH, as well as NADPH, for the reduction of the FAD coenzyme. In order to explore the basis for cofactor promiscuity, structure-guided mutation of two residues in the cofactor binding site, Gln193 and His194, in SMFMO were performed in an attempt to imitate the cofactor binding site of the NADPH-dependent FMO from Methylophaga aminisulfidivorans sp. SK1 (mFMO), in which structurally homologous residues Arg234 and Thr235 bind the NADPH 2?-ribose phosphate. Mutation of His194 to threonine proved most significant, with a switch in specificity from NADH to NADPH [(kcat/Km NADH)/kcat/Km NADPH) from 1.5:1 to 1:3.5, mostly as a result of a reduced Km for NADPH of approximately sevenfold in the His194Thr mutant. The structure of the Gln193Arg/His194Thr mutant revealed no substantial changes in the backbone of the enzyme or orientation of side chains resulting from mutation. Mutation of Phe52, in the vicinity of FAD, and which in mFMO is an asparagine thought to be responsible for flavin hydroperoxide stabilisation, is, in SMFMO, a determinant of enantioselectivity in sulfoxidation. Mutation of Phe52 to valine resulted in a mutant that transformed para-tolyl methyl sulfide into the (S)-sulfoxide with 32% e.e., compared to 25% (R)- for the wild type. These results shed further light both on the cofactor specificity of FPMOs, and their determinants of enantioselectivity, with a view to informing engineering studies of FPMOs in the future. PMID:24251114

  20. 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

  1. Diversity of bacteria nesting the plant cover of north Sinai deserts, Egypt

    PubMed Central

    Hanna, Amira L.; Youssef, Hanan H.; Amer, Wafaa M.; Monib, Mohammed; Fayez, Mohammed; Hegazi, Nabil A.

    2012-01-01

    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

  2. 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.

  3. Identification of a Series of Tricyclic Natural Products as Potent Broad-Spectrum Inhibitors of Metallo-?-Lactamases

    PubMed Central

    Payne, David J.; Hueso-Rodríguez, Juan Antonio; Boyd, Helen; Concha, Néstor O.; Janson, Cheryl A.; Gilpin, Martin; Bateson, John H.; Cheever, Christy; Niconovich, Nancy L.; Pearson, Stewart; Rittenhouse, Stephen; Tew, David; Díez, Emilio; Pérez, 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 Å. 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

  4. Identification of a series of tricyclic natural products as potent broad-spectrum inhibitors of metallo-beta-lactamases.

    PubMed

    Payne, David J; Hueso-Rodríguez, Juan Antonio; Boyd, Helen; Concha, Néstor O; Janson, Cheryl A; Gilpin, Martin; Bateson, John H; Cheever, Christy; Niconovich, Nancy L; Pearson, Stewart; Rittenhouse, Stephen; Tew, David; Díez, Emilio; Pérez, Paloma; De La Fuente, Jesus; Rees, Michael; Rivera-Sagredo, Alfonso

    2002-06-01

    This work describes the discovery and characterization of a novel series of tricyclic natural product-derived metallo-beta-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-beta-lactamases. SB236050, SB238569, and SB236049 were successfully extracted and purified from this extract. The most active of these compounds was SB238569, which possessed K(i) values of 79, 17, and 3.4 microM for the Bacillus cereus II, Pseudomonas aeruginosa IMP-1, and Bacteroides fragilis CfiA metallo-beta-lactamases, respectively, yet none of the compounds exhibited any inhibitory activity against the Stenotrophomonas maltophilia L-1 metallo-beta-lactamase (50% inhibitory concentration > 1,000 microM). The lack of activity against angiotensin-converting enzyme and serine beta-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 A. 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 < or = 4 microg/ml). Consequently, this series of metallo-beta-lactamase inhibitors exhibit the most promising antibacterial synergy activity so far observed against organisms producing metallo-beta-lactamases. PMID:12019104

  5. 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

  6. Novel cyclic di-GMP effectors of the YajQ protein family control bacterial virulence.

    PubMed

    An, Shi-qi; Caly, Delphine L; McCarthy, Yvonne; Murdoch, Sarah L; Ward, Joseph; Febrer, Melanie; Dow, J Maxwell; Ryan, Robert P

    2014-10-01

    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 (K(d)?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

  7. Detection of extended spectrum ?-lactamase in Pseudomonas spp. isolated from two tertiary care hospitals in Bangladesh

    PubMed Central

    2013-01-01

    Background Extended spectrum ß-lactamases (ESBLs) represent a major group of lactamases responsible for resistance, mostly produced by gram-negative bacteria, to newer generations of ß-lactam drugs currently being identified in large numbers worldwide. The present study was undertaken to see the frequency of ESBL producing Pseudomonas spp. isolated from six hundred clinical specimens (wound, pus, aural, urine, sputum, throat and other swabs) collected over a period of three years from two tertiary care hospitals in Bangladesh. Findings Aerobic bacterial culture was performed on aseptically collected swabs and only growth of Pseudomonas was considered for further species identification and ESBL production along with serotyping of Pseudomonas aeruginosa. Antimicrobial susceptibility testing was carried out using the Kirby-Bauer agar diffusion method and ESBL production was detected on Mueller Hinton agar by double-disk synergy technique using Amoxicillin-Clavulanic acid with Ceftazidime, Cefotaxime, Ceftriaxone and Aztreonam. Culture yielded 120 Pseudomonas spp. and 82 of them were biochemically characterized for species. Pseudomonas aeruginosa was found to be the predominant (90.2%) species. Of 82 isolates tested for ESBL, 31 (37.8%) were ESBL positive with 29 (93.5%) as Pseudomonas aeruginosa, the remaining 2 (6.5%) were Stenotrophomonas maltophilia and Ralstonia pickettii. Antibiogram revealed Imipenem as the most effective drug (93.3%) among all antimicrobials used against Pseudomonas spp. followed by Aminoglycosides (63.7%). Conclusion ESBL producing Pseudomonas spp. was found to be a frequent isolate from two tertiary care hospitals in Bangladesh, showing limited susceptibility to antimicrobials and decreased susceptibility to Imipenem in particular, which is a matter of great concern. PMID:23289861

  8. Additional observations and notes on the natural history of the prairie rattlesnake (Crotalus viridis) in Colorado.

    PubMed

    Fitzgerald, Kevin T; Shipley, Bryon K; Newquist, Kristin L; Vera, Rebecca; Flood, Aryn A

    2013-11-01

    On account of their unique anatomy, physiology, natural history, ecology, and behavior, rattlesnakes make ideal subjects for a variety of different scientific disciplines. The prairie rattlesnake (Crotalus viridis) in Colorado was selected for investigation of its relationship to colonies of black-tailed prairie dogs (Cynomys ludovicianus) with regard to spatial ecology. A total of 31 snakes were anesthetized and had radiotransmitters surgically implanted. In addition, at the time of their capture, all snakes underwent the following: (1) they had bacterial culture taken from their mouths for potential isolation of pathogenic bacteria; (2) similarly, they had cloacal bacterial cultures taken to assess potentially harmful bacteria passed in the feces; and (3) they had blood samples drawn to investigate the presence of any zoonotic agents in the serum of the snakes. The results of the study and their implications are discussed here. Traditionally, a low incidence of bacterial wound infection has been reported following snakebite. Nevertheless, the oral cavity of snakes has long been known to house a wide variety of bacterial flora. In our study, 10 different bacterial species were isolated from the mouths of the rattlesnakes, 6 of which are capable of being zoonotic pathogens and inducing human disease. More studies are necessary to see why more rattlesnake bites do not become infected despite the presence of such pathogenic bacteria. The results of fecal bacteria isolated revealed 13 bacterial species, 12 of which can cause disease in humans. Of the snakes whose samples were cultured, 26% were positive for the presence of the pathogen Salmonella arizonae, one of the causative agents of reptile-related salmonellosis in humans. It has long been reported that captive reptiles have a much higher incidence than wild, free-ranging species. This study shows the incidence of Salmonella in a wild, free-ranging population of rattlesnakes. In addition, Stenotrophomonas maltophilia was isolated. This bacterium is associated with wound and soft tissue infections that can lead to sepsis, endocarditis, meningitis, and peritonitis. In addition, this bacterium has been increasingly implicated as an opportunistic pathogen to humans during pregnancies, hospitalizations, malignancies and chemotherapy, chronic respiratory diseases, and presurgical endotracheal intubation. Furthermore, S. maltophilia has an intense resistance to broad-spectrum antibiotics, the results of our study showed the bacterium was resistant to multiple antibiotics. Our results indicate that anyone working with snake feces, dead skin, or their carcasses must follow reasonable hygiene protocols. Rattlesnakes tested for West Nile antibodies had positive results but these were invalidated owing to possible cross-reactivity with other unknown viruses, interference with snake serum proteins, and the fact that the test was not calibrated for rattlesnake serum. Still, the interesting implication remains, should we be regularly testing these animals as sentinels against potentially zoonotic diseases. The results of this study clearly show the value of veterinarians in a multidisciplinary study of this sort and the particular skill set they can offer. Veterinarians must get involved in conservation studies if the biodiversity of the planet is to be preserved. PMID:24331557

  9. 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.

  10. 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

  11. 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.

  12. 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 ?g/ml, respectively. Ceftobiprole was active against methicillin-resistant S. aureus (MRSA) (98.3% susceptible) and methicillin-resistant CoNS, having a MIC90 of 2 ?g/ml. Ceftobiprole was active against Enterococcus faecalis (MIC50/90, 0.5/4 ?g/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 ?g/ml. The potency of ceftobiprole against Pseudomonas aeruginosa (MIC50/90, 2/>8 ?g/ml; 64.6% at MIC values of ? 4 ?g/ml) was similar to that of ceftazidime (MIC50/90, 2/>16 ?g/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 ?g/ml) and Moraxella catarrhalis (MIC50/90, ? 0.06/0.25 ?g/ml) isolates. Ceftobiprole demonstrated a wide spectrum of antimicrobial activity against this very large longitudinal sample of contemporary pathogens. PMID:24777091

  13. Stability of a promiscuous plasmid in different hosts: no guarantee for a long-term relationship.

    PubMed

    De Gelder, Leen; Ponciano, José M; Joyce, Paul; Top, Eva M

    2007-02-01

    Broad-host-range (BHR) IncP-1 plasmids have the ability to transfer between and replicate in nearly all species of the Alpha-, Beta- and Gammaproteobacteria, but surprisingly few data are available on the stability of these plasmids in strains within their host range. Moreover, even though molecular interactions between the bacterial host and its plasmid(s) exist, no systematic study to date has compared the stability of the same plasmid among different hosts. The goal of this study was to examine whether the stability characteristics of an IncP-1 plasmid can be variable between strains within the host range of the plasmid. Therefore, 19 strains within the Alpha-, Beta- or Gammaproteobacteria carrying the IncP-1beta plasmid pB10 were serially propagated in non-selective medium and the fraction of segregants was monitored through replica-picking. Remarkably, a large variation in the stability of pB10 in different strains was found, even between strains within the same genus or species. Ten strains showed no detectable plasmid loss over about 200 generations, and in two strains plasmid-free clones were only sporadically observed. In contrast, three strains, Pseudomonas koreensis R28, Pseudomonas putida H2 and Stenotrophomonas maltophilia P21, exhibited rapid plasmid loss within 80 generations. Parameter estimation after mathematical modelling of these stability data suggested high frequencies of segregation (about 0.04 per generation) or high plasmid cost (i.e. a relative fitness decrease in plasmid-bearing cells of about 15 and 40 %), which was confirmed experimentally. The models also suggested that plasmid reuptake by conjugation only played a significant role in plasmid stability in one of the three strains. Four of the 19 strains lost the plasmid very slowly over about 600 generations. The erratic decrease of the plasmid-containing fraction and simulation of the data with a new mathematical model suggested that plasmid cost was variable over time due to compensatory mutations. The findings of this study demonstrate that the ability of a so-called 'BHR' plasmid to persist in a bacterial population is influenced by strain-specific traits, and therefore observations made for one strain should not be generalized for the entire species or genus. PMID:17259616

  14. 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

  15. 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

  16. 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.

  17. 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

  18. Broad-range PCR, cloning and sequencing of the full 16S rRNA gene for detection of bacterial DNA in synovial fluid samples of Tunisian patients with reactive and undifferentiated arthritis

    PubMed Central

    Siala, Mariam; Gdoura, Radhouane; Fourati, Hela; Rihl, Markus; Jaulhac, Benoit; Younes, Mohamed; Sibilia, Jean; Baklouti, Sofien; Bargaoui, Naceur; Sellami, Slaheddine; Sghir, Abdelghani; Hammami, Adnane

    2009-01-01

    Introduction Broad-range rDNA PCR provides an alternative, cultivation-independent approach for identifying bacterial DNA in reactive and other form of arthritis. The aim of this study was to use broad-range rDNA PCR targeting the 16S rRNA gene in patients with reactive and other forms of arthritis and to screen for the presence of DNA from any given bacterial species in synovial fluid (SF) samples. Methods We examined the SF samples from a total of 27 patients consisting of patients with reactive arthritis (ReA) (n = 5), undifferentiated arthritis (UA) (n = 9), rheumatoid arthritis (n = 7), and osteoarthritis (n = 6) of which the latter two were used as controls. Using broad-range bacterial PCR amplifying a 1400 bp fragment from the 16S rRNA gene, we identified and sequenced at least 24 clones from each SF sample. To identify the corresponding bacteria, DNA sequences were compared to the EMBL (European Molecular Biology Laboratory) database. Results Bacterial DNA was identified in 20 of the 27 SF samples (74, 10%). Analysis of a large number of sequences revealed the presence of DNA from more than one single bacterial species in the SF of all patients studied. The nearly complete sequences of the 1400 bp were obtained for most of the detected species. DNA of bacterial species including Shigella species, Escherichia species, and other coli-form bacteria as well as opportunistic pathogens such as Stenotrophomonas maltophilia and Achromobacter xylosoxidans were shared in all arthritis patients. Among pathogens described to trigger ReA, DNA from Shigella sonnei was found in ReA and UA patients. We also detected DNA from rarely occurring human pathogens such as Aranicola species and Pantoea ananatis. We also found DNA from bacteria so far not described in human infections such as Bacillus niacini, Paenibacillus humicus, Diaphorobacter species and uncultured bacterium genera incertae sedis OP10. Conclusions Broad-range PCR followed by cloning and sequencing the entire 16S rDNA, allowed the identification of the bacterial DNA environment in the SF samples of arthritic patients. We found a wide spectrum of bacteria including those known to be involved in ReA and others not previously associated with arthritis. PMID:19570210

  19. 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 ?g/ml, respectively. Ceftobiprole was active against methicillin-resistant S. aureus (MRSA) (98.3% susceptible) and methicillin-resistant CoNS, having a MIC90 of 2 ?g/ml. Ceftobiprole was active against Enterococcus faecalis (MIC50/90, 0.5/4 ?g/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 ?g/ml. The potency of ceftobiprole against Pseudomonas aeruginosa (MIC50/90, 2/>8 ?g/ml; 64.6% at MIC values of ?4 ?g/ml) was similar to that of ceftazidime (MIC50/90, 2/>16 ?g/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 ?g/ml) and Moraxella catarrhalis (MIC50/90, ?0.06/0.25 ?g/ml) isolates. Ceftobiprole demonstrated a wide spectrum of antimicrobial activity against this very large longitudinal sample of contemporary pathogens. PMID:24777091

  20. 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 ...

  1. Analysis of Bacterial Community Structure in Sulfurous-Oil-Containing Soils and Detection of Species Carrying Dibenzothiophene Desulfurization (dsz) Genes

    PubMed Central

    Duarte, Gabriela Frois; Rosado, Alexandre Soares; Seldin, Lucy; de Araujo, Welington; van Elsas, Jan Dirk

    2001-01-01

    The selective effects of sulfur-containing hydrocarbons, with respect to changes in bacterial community structure and selection of desulfurizing organisms and genes, were studied in soil. Samples taken from a polluted field soil (A) along a concentration gradient of sulfurous oil and from soil microcosms treated with dibenzothiophene (DBT)-containing petroleum (FSL soil) were analyzed. Analyses included plate counts of total bacteria and of DBT utilizers, molecular community profiling via soil DNA-based PCR-denaturing gradient gel electrophoresis (PCR-DGGE), and detection of genes that encode enzymes involved in the desulfurization of hydrocarbons, i.e., dszA, dszB, and dszC.Data obtained from the A soil showed no discriminating effects of oil levels on the culturable bacterial numbers on either medium used. Generally, counts of DBT degraders were 10- to 100-fold lower than the total culturable counts. However, PCR-DGGE showed that the numbers of bands detected in the molecular community profiles decreased with increasing oil content of the soil. Analysis of the sequences of three prominent bands of the profiles generated with the highly polluted soil samples suggested that the underlying organisms were related to Actinomyces sp., Arthrobacter sp., and a bacterium of uncertain affiliation. dszA, dszB, and dszC genes were present in all A soil samples, whereas a range of unpolluted soils gave negative results in this analysis. Results from the study of FSL soil revealed minor effects of the petroleum-DBT treatment on culturable bacterial numbers and clear effects on the DBT-utilizing communities. The molecular community profiles were largely stable over time in the untreated soil, whereas they showed a progressive change over time following treatment with DBT-containing petroleum. Direct PCR assessment revealed the presence of dszB-related signals in the untreated FSL soil and the apparent selection of dszA- and dszC-related sequences by the petroleum-DBT treatment. PCR-DGGE applied to sequential enrichment cultures in DBT-containing sulfur-free basal salts medium prepared from the A and treated FSL soils revealed the selection of up to 10 distinct bands. Sequencing a subset of these bands provided evidence for the presence of organisms related to Pseudomonas putida, a Pseudomonas sp., Stenotrophomonas maltophilia, and Rhodococcus erythropolis. Several of 52 colonies obtained from the A and FSL soils on agar plates with DBT as the sole sulfur source produced bands that matched the migration of bands selected in the enrichment cultures. Evidence for the presence of dszB in 12 strains was obtained, whereas dszA and dszC genes were found in only 7 and 6 strains, respectively. Most of the strains carrying dszA or dszC were classified as R. erythropolis related, and all revealed the capacity to desulfurize DBT. A comparison of 37 dszA sequences, obtained via PCR from the A and FSL soils, from enrichments of these soils, and from isolates, revealed the great similarity of all sequences to the canonical (R. erythropolis strain IGTS8) dszA sequence and a large degree of internal conservation. The 37 sequences recovered were grouped in three clusters. One group, consisting of 30 sequences, was minimally 98% related to the IGTS8 sequence, a second group of 2 sequences was slightly different, and a third group of 5 sequences was 95% similar. The first two groups contained sequences obtained from both soil types and enrichment cultures (including isolates), but the last consisted of sequences obtained directly from the polluted A soil. PMID:11229891

  2. Salisediminibacterium haloalkalitolerans sp. nov., isolated from Lonar soda lake, India, and a proposal for reclassification of Bacillus locisalis as Salisediminibacterium locisalis comb. nov., and the emended description of the genus Salisediminibacterium and of the species Salisediminibacterium halotolerans.

    PubMed

    Sultanpuram, Vishnuvardhan Reddy; Mothe, Thirumala; Mohammed, Farooq

    2015-05-01

    A Gram stain-positive, rod-shaped, non-motile, orange-pigmented and non-endospore-forming novel bacterial strain 10nlg(T) was isolated from Lonar soda lake in India. Based on the 16S rRNA gene sequence analysis, it was belonged to the genus Salisediminibacterium and was most closely related to Salisediminibacterium halotolerans CGMCC 1.7654(T) (99.9 %), Bacillus locisalis CGMCC 1.6286(T) (99.1 %) and other members in the Bacillaceae (<93.6 %). Further, DNA-DNA hybridization results demonstrated that strain 10nlg(T) was distantly (<70 %) related to S. halotolerans halo-2(T) (59.6 %) and B. locisalis CGMCC 1.6286(T) (53.2 %). Strain 10nlg(T) was catalase positive and oxidase negative. The cell wall of the strain 10nlg(T) contains meso-diaminopimelic acid as the diagnostic amino acid. Polar lipids include diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, five phospholipids and two unknown lipids. The predominant isoprenoid quinone was MK-7. Anteiso-C15:0 (32.6 %) was the predominant fatty acid, and significant proportions of iso-C15:0 (9.3 %), anteiso-C17:0 (8.3 %), C16:0 (4.3 %) were also detected in the strain 10nlg(T). The DNA G+C content of the strain 10nlg(T) was 45.6 mol %. The results of phylogenetic, physiological and biochemical tests allowed a distinct differentiation of strain 10nlg(T) not only from S. halotolerans halo-2(T), the only member of the genus Salisediminibacterium, but also from the related Bacillaceae members. Strain 10nlg(T) represents a novel species of the genus Salisediminibacterium for which the name Salisediminibacterium haloalkalitolerans sp. nov. is proposed. The type strain is 10nlg(T) (=KCTC 33414(T) = CGMCC 1.12818(T)). B. locisalis CGMCC 1.6286(T) also represents a member of the genus Salisediminibacterium for which the name Salisediminibacterium locisalis CG1(T) is proposed. The type strain is CG1(T) = (CCM 7370(T) = CECT 7152(T) = CGMCC 1.6286(T) = DSM 18085(T)). In accordance with the new polar lipid data collected in this study, emended descriptions of the genus Salisediminibacterium and the species S. halotolerans halo-2(T) are also provided. PMID:25638045

  3. 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. ...

  4. 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

  5. Bensingtonia rectispora sp. nov. and Bensingtonia bomiensis sp. nov., ballistoconidium-forming yeast species from Tibetan plant leaves.

    PubMed

    Wang, Qi-Ming; Boekhout, Teun; Bai, Feng-Yan

    2012-08-01

    Five yeast strains isolated from plant leaves collected in south-east Tibet formed cream to brownish colonies and produced asymmetrical ballistoconidia and CoQ-9 as the major ubiquinone. Sequence analysis of the 26S rRNA D1/D2 domain and the internal transcribed spacer region indicated that these strains represented two novel species of the genus Bensingtonia. The names Bensingtonia rectispora sp. nov. (type strain XZ 4C5(T)?=?CGMCC 2.02635(T)?=?CBS 10710(T)) and Bensingtonia bomiensis sp. nov. (type strain XZ 33D1(T)?=?CGMCC 2.02670(T)?=?CBS 10713(T)) are proposed for the two novel species, which are phylogenetically closely related to Bensingtonia naganoensis, Bensingtonia pseudonaganoensis and the type species of the genus, Bensingtonia ciliata. PMID:22081720

  6. 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

  7. 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

  8. Complete genome sequence of Lactobacillus paracasei L9, a new probiotic strain with high lactic acid-producing capacity.

    PubMed

    Jiang, Yunyun; Li, Zhuanyu; Ren, Fazheng; Liu, Songling; Zhao, Liang; Sun, Erna; Zhang, Ming; Guo, Huiyuan; Zhang, Hao; Jiang, Lu; Hou, Caiyun

    2015-12-20

    Lactobaillus paracasei L9 (CGMCC No. 9800) is a new strain with probiotic properties originating from healthy human intestine. Previous studies evidenced that the strain regulates immune modulation and contributes to the production of high amounts of lactic acid. The genome of L. paracasei L9 contains a circular 3076,437-bp chromosome, encoding 3044 CDSs, 15 rRNA genes and 59 tRNA genes. PMID:26415658

  9. Consequences of cps mutation of Klebsiella pneumoniae on 1,3-propanediol fermentation.

    PubMed

    Guo, Ni-Ni; Zheng, Zong-Ming; Mai, Yu-Lin; Liu, Hong-Juan; Liu, De-Hua

    2010-03-01

    The filtration in 1,3-propanediol (1,3-PD) downstream process is influenced by the large amounts of capsular polysaccharides (CPS) produced by Klebsiella pneumoniae CGMCC 1.6366. The morphological and fermentation properties were investigated with the CPS-deficient mutant K. pneumoniae CGMCC 1.6366 CPS. Similar biomass was obtained with CGMCC 1.6366, and the mutant strain in batch cultures indicating the cell growth was slightly inhibited by CPS defection. The viscosity of fermentation broth by mutant strain decreased by 27.45%. The flux with ceramic membrane filter was enhanced from 168.12 to 303.6 l h(-1) m(-2), exhibiting the great importance for downstream processing of 1,3-PD fermentation. The products spectrum of mutant isolate changed remarkably regarding to the concentration of fermentation products. The synthesis of important 1,3-PD and 2,3-butanediol was enhanced from 9.73 and 4.06 g l(-1) to 10.37 and 4.77 g l(-1) in batch cultures. The noncapsuled K. pneumoniae provided higher 1,3-PD yield of 0.54 mol mol(-1) than that of encapsuled wild parent in batch cultures. The fed-batch fermentation of mutant strain resulted in 1,3-PD concentration, yield, and productivity of 78.13 g l(-1), 0.53 mol mol(-1), and 1.95 g l(-1) h(-1), respectively. PMID:19936735

  10. 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

  11. Genome sequence of Cellvibrio pealriver PR1, a xylanolytic and agarolytic bacterium isolated from freshwater.

    PubMed

    Xie, Zhangzhang; Lin, Weitie; Luo, Jianfei

    2015-11-20

    Cellvibrio pealriver PR1 (CGMCC 1.14955=NBRC 110968) was isolated from a freshwater sample from the Pearl River in China. It is able to degrade various carbohydrates such as starch, xylan, agar, cellulose or chitin. The genomic feature and polysaccharide hydrolases of this strain were described in this paper. The total genome size of C. pealriver PR1 is 4,427,922bp with 3986 coding sequences (CDS), 53 tRNAs, 16 rRNAs and 1 sRNA. The annotated full genome sequence of this strain provides the genetic basis for revealing its role as a xylanolytic and agarolytic bacterium. PMID:26253962

  12. 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

  13. 2H-pyran-2-one and 2H-furan-2-one derivatives from the plant endophytic fungus Pestalotiopsis fici.

    PubMed

    Liu, Shuchun; Liu, Xiangyu; Guo, Liangdong; Che, Yongsheng; Liu, Ling

    2013-11-01

    Two new ?-pyrones (=2H-pyran-2-ones), ficipyrones A and B (1 and 2, resp.), and two new ?-furanones (=2H-furan-2-ones), ficifuranones A and B (3 and 4, resp.), together with three known metabolites, antibiotic F 0368 (5), hydroxyseiridin (6), and hydroxyisoseiridin (7), were isolated from solid cultures of the plant endophytic fungus Pestalotiopsis fici. Their structures were elucidated primarily by NMR spectroscopy, and the absolute configuration of 1 was deduced from the circular-dichroism (CD) data. Compound 1 showed antifungal activity against the plant pathogen Gibberella zeae (CGMCC 3.2873) with an IC50 value of 15.9 ?M. PMID:24243609

  14. 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

  15. 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

  16. Taxonomic study of the genera Halogeometricum and Halosarcina: transfer of Halosarcina limi and Halosarcina pallida to the genus Halogeometricum as Halogeometricum limi comb. nov. and Halogeometricum pallidum comb. nov., respectively

    PubMed Central

    Qiu, Xing-Xing; Zhao, Mei-Lin; Han, Dong; Zhang, Wen-Jiao; Dyall-Smith, Mike L.

    2013-01-01

    Members of the haloarchaeal genera Halosarcina and Halogeometricum (family Halobacteriaceae) are closely related to each other and show 96.6–98?% 16S rRNA gene sequence similarity. This is higher than the accepted threshold value (95?%) to separate two genera, and a taxonomic study using a polyphasic approach of all four members of the two genera was conducted to clarify their relationships. Polar lipid profiles indicated that Halogeometricum rufum RO1-4T, Halosarcina pallida BZ256T and Halosarcina limi RO1-6T are related more to each other than to Halogeometricum borinquense CGMCC 1.6168T. Phylogenetic analyses using the sequences of three different genes (16S rRNA gene, rpoB? and EF-2) strongly supported the monophyly of these four species, showing that they formed a distinct clade, separate from the related genera Halopelagius, Halobellus, Haloquadratum, Haloferax and Halogranum. The results indicate that the four species should be assigned to the same genus, and it is proposed that Halosarcina pallida and Halosarcina limi be transferred to the genus Halogeometricum as Halogeometricum pallidum comb. nov. (type strain, BZ256T?=?KCTC 4017T?=?JCM 14848T) and Halogeometricum limi comb. nov. (type strain, RO1-6T?=?CGMCC 1.8711T?=?JCM 16054T). PMID:24097833

  17. 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

  18. Rational design of catechol-2, 3-dioxygenase for improving the enzyme characteristics.

    PubMed

    Wei, Jiashi; Zhou, Ying; Xu, Tao; Lu, Baorong

    2010-09-01

    Catechol-2, 3-dioxygenase (C23O) from Pseudomonas sp. CGMCC2953 identified in our laboratory, which is one of the key enzymes responsible for phenanthrene biodegradation, was expected to get better characteristics tolerant to environment for its further application. With the aim of improving the enzyme properties by introducing intermolecular disulfide bonds, X-ray structure of a C23O from Pseudomonas putida MT-2, a highly conserved homologous with the C23O from Pseudomonas sp. CGMCC2953, was directly used to find the potential sites for forming disulfide bonds between two monomers of the target C23O. Two sites, Ala229 and His294, were identified and mutated to cysteine, respectively, by using site mutagenesis. The expected disulfide bond between these two CYS residues was confirmed with both molecular modeling and experimental results. The optimum temperature of the mutated enzyme was widened from 40 to 40 approximately 50 degrees C. The mutated C23O became more alkalescency stable compared with the wild-type enzyme, e.g., 75% of the maximal enzyme activity retained even under pH 9.5 while 50% residue for the wild-type one. Improvement of thermostability of the mutated C230 with the redesigned disulfide was also confirmed. PMID:19688300

  19. Ethanol Production from Nondetoxified Dilute-Acid Lignocellulosic Hydrolysate by Cocultures of Saccharomyces cerevisiae Y5 and Pichia stipitis CBS6054

    PubMed Central

    Wan, Ping; Zhai, Dongmei; Wang, Zhen; Yang, Xiushan; Tian, Shen

    2012-01-01

    Saccharomyces cerevisiae Y5 (CGMCC no. 2660) and Issatchenkia orientalis Y4 (CGMCC no. 2159) were combined individually with Pichia stipitis CBS6054 to establish the cocultures of Y5 + CBS6054 and Y4 + CBS6054. The coculture Y5 + CBS6054 effectively metabolized furfural and HMF and converted xylose and glucose mixture to ethanol with ethanol concentration of 16.6?g/L and ethanol yield of 0.46?g ethanol/g sugar, corresponding to 91.2% of the maximal theoretical value in synthetic medium. Accordingly, the nondetoxified dilute-acid hydrolysate was used to produce ethanol by co-culture Y5 + CBS6054. The co-culture consumed glucose along with furfural and HMF completely in 12?h, and all xylose within 96?h, resulting in a final ethanol concentration of 27.4?g/L and ethanol yield of 0.43?g ethanol/g sugar, corresponding to 85.1% of the maximal theoretical value. The results indicated that the co-culture of Y5 + CBS6054 was a satisfying combination for ethanol production from non-detoxified dilute-acid lignocellulosic hydrolysates. This co-culture showed a promising prospect for industrial application. PMID:22792472

  20. Ethanol Production from Nondetoxified Dilute-Acid Lignocellulosic Hydrolysate by Cocultures of Saccharomyces cerevisiae Y5 and Pichia stipitis CBS6054.

    PubMed

    Wan, Ping; Zhai, Dongmei; Wang, Zhen; Yang, Xiushan; Tian, Shen

    2012-01-01

    Saccharomyces cerevisiae Y5 (CGMCC no. 2660) and Issatchenkia orientalis Y4 (CGMCC no. 2159) were combined individually with Pichia stipitis CBS6054 to establish the cocultures of Y5 + CBS6054 and Y4 + CBS6054. The coculture Y5 + CBS6054 effectively metabolized furfural and HMF and converted xylose and glucose mixture to ethanol with ethanol concentration of 16.6?g/L and ethanol yield of 0.46?g ethanol/g sugar, corresponding to 91.2% of the maximal theoretical value in synthetic medium. Accordingly, the nondetoxified dilute-acid hydrolysate was used to produce ethanol by co-culture Y5 + CBS6054. The co-culture consumed glucose along with furfural and HMF completely in 12?h, and all xylose within 96?h, resulting in a final ethanol concentration of 27.4?g/L and ethanol yield of 0.43?g ethanol/g sugar, corresponding to 85.1% of the maximal theoretical value. The results indicated that the co-culture of Y5 + CBS6054 was a satisfying combination for ethanol production from non-detoxified dilute-acid lignocellulosic hydrolysates. This co-culture showed a promising prospect for industrial application. PMID:22792472

  1. Fast-Growing, Aerobic, Heterotrophic Bacteria from the Rhizosphere of Young Sugar Beet Plants

    PubMed Central

    Lambert, Bart; Meire, Patrick; Joos, Henk; Lens, Pierre; Swings, Jean

    1990-01-01

    Fast-growing, aerobic, heterotrophic bacteria from the root surface of young sugar beet plants were inventoried. Isolation of the most abundant bacteria from the root surface of each of 1,100 plants between the second and tenth leaf stage yielded 5,600 isolates. These plants originated from different fields in Belgium and Spain. All isolates were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of total cellular proteins. Comparison of protein fingerprints allowed us to inventory the bacteria of individual plants of different fields or leaf stages and to analyze the composition and variability of the rhizobacterial population of young sugar beet plants. Each field harbored a specific population of bacteria which showed a highly hierarchic structure. A small number of bacteria occurring frequently at high densities dominated in each field. The major bacteria were identified as Pseudomonas fluorescens, Xanthomonas maltophilia, Pseudomonas paucimobilis, and Phyllobacterium sp. The former three species showed a high genetic variability as they were represented by different protein fingerprint types on the same or different fields or leaf stages. Twinspan analysis and relative abundance plots showed that the structure and composition of the bacterial populations varied strongly over time. Pseudomonads were typically early colonizers which were later replaced by X. maltophilia or Phyllobacterium sp. Images PMID:16348342

  2. 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

  3. 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-? gene (EF1-?), 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

  4. Efficient production of dihydroxyacetone from biodiesel-derived crude glycerol by newly isolated Gluconobacter frateurii.

    PubMed

    Liu, Yu-Peng; Sun, Yang; Tan, Cong; Li, Hua; Zheng, Xiao-Juan; Jin, Kui-Qi; Wang, Gang

    2013-08-01

    The efficient production of dihydroxyacetone (DHA) on biodiesel-derived glycerol based media was developed. A newly isolated strain, Gluconobacter frateurii CGMCC 5397, could convert crude glycerol to DHA with high yield and productivity. In shake-flask fermentation, the DHA concentration of 73.1 gl(-1) was attained at 48 h using an optimum medium containing biodiesel-derived crude glycerol. When fed-batch fermentation was carried out in a 7-l stirred bioreactor with crude glycerol, the DHA concentration, productivity, and yield were 125.8 gl(-1), 2.6 gl(-1)h(-1), and 90.5% at 48 h, respectively. This study suggests that the inexpensive biodiesel-derived crude glycerol could be utilized for efficient production of DHA by G. frateurii. PMID:23748086

  5. 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

  6. 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.

  7. 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

  8. Actinomadura jiaoheensis sp. nov. and Actinomadura sporangiiformans sp. nov., two novel actinomycetes isolated from muddy soil and emended description of the genus Actinomadura.

    PubMed

    Zhao, Junwei; Guo, Lifeng; Sun, Pengyu; Han, Chuanyu; Bai, Lu; Liu, Chongxi; Li, Yunxi; Xiang, Wensheng; Wang, Xiangjing

    2015-12-01

    Two novel actinomycetes, designated strains NEAU-Jh1-3(T) and NEAU-Jh2-5(T), were isolated from muddy soil collected from a riverbank in Jiaohe, Jilin Province, north China. A polyphasic study was carried out to establish the taxonomic positions of these strains. The 16S rRNA gene sequence analysis showed that the two novel isolates exhibited 99.9 % 16S rRNA gene sequence similarity with each other and that they are closely related to Actinomadura viridis IFO 15238(T) (99.6, 99.6 %) and Actinomadura vinacea IFO 14688(T) (99.3, 99.3 %). Phylogenetic analysis based on the 16S rRNA gene sequences indicated that the two cultures clustered together and formed a cluster with A. viridis IFO 15238(T), A. vinacea IFO 14688(T) and Actinomadura rugatobispora IFO 14382(T). However, the DNA-DNA hybridization value between strains NEAU-Jh1-3(T) and NEAU-Jh2-5(T) was 63.6 %, and the values between the two strains and their close phylogenetic relatives were also below 70 %. With reference to phenotypic characteristics, phylogenetic data and DNA-DNA hybridization results, the two strains can be distinguished from each other and their close phylogenetic relatives. Thus, strains NEAU-Jh1-3(T) and NEAU-Jh2-5(T) represent two novel species of the genus Actinomadura, for which the names Actinomadura jiaoheensis sp. nov. and Actinomadura sporangiiformans sp. nov. are proposed. The type strains are NEAU-Jh1-3(T) (=CGMCC 4.7197(T) = JCM 30341(T)) and NEAU-Jh2-5(T) (=CGMCC 4.7211(T) = JCM 30342(T)), respectively. PMID:26373415

  9. Nocardioides szechwanensis sp. nov. and Nocardioides psychrotolerans sp. nov., isolated from a glacier.

    PubMed

    Liu, Qing; Xin, Yu-hua; Liu, Hong-can; Zhou, Yu-guang; Wen, Ying

    2013-01-01

    Two Gram-positive, rod-shaped, non-spore-forming bacteria (strains RHLT(1)-17(T) and RHLT(2)-1(T)) were isolated from Hailuogou glacier in Szechwan province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strains belonged to the genus Nocardioides and shared 97.8?% sequence similarity with each other and 97.6 and 98.4 % sequence similarity, respectively, with Nocardioides kribbensis KSL-2(T). Strain RHLT(1)-17(T) grew at 0-35 °C and strain RHLT(2)-1(T) grew at 0-25 °C. The major cellular fatty acids of strain RHLT(1)-17(T) were C(17 : 1)?8c (32.69 %) and iso-C(16 : 0) (21.74 %). The major cellular fatty acids of strain RHLT(2)-1(T) were C(18 : 1)?9c (28.72 %), summed feature 3 (17.14 %; comprising C(16 : 1)?7c and/or C(16 : 1)?6c), iso-C(16 : 0) (14.35 %), C(16 : 0) (9.96 %) and iso-C(14 : 0) (8.34 %). Both strains contained ll-2,6-diaminopimelic acid in the cell-wall peptidoglycan and MK-8(H(4)) as the predominant menaquinone. On the basis of data obtained using a polyphasic approach, two novel species, Nocardioides szechwanensis sp. nov. (type strain RHLT(1)-17(T) = CGMCC 1.11147(T) = NBRC 108562(T)) and Nocardioides psychrotolerans sp. nov. (type strain RHLT(2)-1(T) =CGMCC 1.11156(T) = NBRC 108563(T)), are proposed. PMID:22345140

  10. Streptomyces albiflavescens sp. nov., an actinomycete isolated from soil.

    PubMed

    Han, Xiufang; Zheng, Jimei; Xin, Di; Xin, Yuhua; Wei, Xuexin; Zhang, Jianli

    2015-05-01

    Two actinobacterial strains, m20(T) and z8, were isolated from soil taken from rainforest areas/tropic forest region, Yunnan Province, south-west China. The 16S rRNA gene sequence similarities and DNA-DNA relatedness values between strains m20(T) and z8 were 100 and 88.2%, respectively, which indicated that these two strains should be classified as the same species. The taxonomic position of the strains was determined by a polyphasic approach. Morphological and chemotaxonomic features of the strains were consistent with those of the genus Streptomyces . A phylogenetic tree based on 16S rRNA gene sequences showed that strains m20(T) and z8 formed an evolutionary branch within the genus Streptomyces and shared relatively high 16S rRNA gene sequence similarity values with other members of this genus, including 'Streptomyces siamensis' NBRC 108799 (98.95%), Streptomyces graminilatus NBRC 108882(T) (98.25%), Streptomyces seoulensis NBRC 16668(T) (98.11%), Streptomyces peucetius ATCC 29050(T) (98.11%) and Streptomyces hygroscopicus subsp. ossamyceticus ATCC 15420(T) (98.11%). DNA-DNA relatedness values between strain m20(T) and the five above-mentioned strains were 56.3, 55.1, 52.8, 50.1 and 48.4%, respectively. On the basis of phenotypic, genotypic and phylogenetic properties, strains m20(T) and z8 could be distinguished from phylogenetically related members of the genus Streptomyces . The isolates thus merit species status within the genus Streptomyces , for which the name http://dx.doi.org/10.1601/nm.6817 Streptomyces albiflavescens sp. nov. is proposed. The type strain is m20(T) (?=CGMCC 4.7111(T)?=KCTC 29196(T)). Strain z8 (?=CGMCC 4.7112=KCTC 29197) is a reference strain. PMID:25687349

  11. Streptosporangium sonchi sp. nov. and Streptosporangium kronopolitis sp. nov., two novel actinobacteria isolated from a root of common sowthistle (Sonchus oleraceus L.) and a millipede (Kronopolites svenhedind Verhoeff).

    PubMed

    Ma, Zhaoxu; Liu, Hui; Liu, Chongxi; He, Hairong; Zhao, Junwei; Wang, Xin; Li, Jiansong; Wang, Xiangjing; Xiang, Wensheng

    2015-06-01

    Two novel actinobacteria, designated strains NEAU-QS7(T) and NEAU-ML10(T), were isolated from a root of Sonchus oleraceus L. and a Kronopolites svenhedind Verhoeff specimen, respectively, collected from Wuchang, Heilongjiang Province, China. A polyphasic study was carried out to establish the taxonomic positions of these strains. The two strains were observed to form abundant aerial hyphae that differentiated into spherical spore vesicles. The phylogenetic analysis based on the 16S rRNA gene sequences of strains NEAU-QS7(T) and NEAU-ML10(T) showed that the two novel isolates exhibited 99.7 % 16S rRNA gene sequence similarity with each other and that they are most closely related to Streptosporangium shengliense NEAU-GH7(T) (99.1, 99.0 %) and Streptosporangium longisporum DSM 43180(T) (99.1, 99.0 %). However, the DNA-DNA hybridization value between strains NEAU-QS7(T) and NEAU-ML10(T) was 46.5 %, and the values between the two strains and their closest phylogenetic relatives were also below 70 %. With reference to phenotypic characteristics, phylogenetic data and DNA-DNA hybridization results, the two strains can be distinguished from each other and their closest phylogenetic relatives. Thus, strains NEAU-QS7(T) and NEAU-ML10(T) represent two novel species of the genus Streptosporangium, for which the names Streptosporangium sonchi sp. nov. and Streptosporangium kronopolitis sp. nov. are proposed. The type strains are NEAU-QS7(T) (=CGMCC 4.7142(T) =DSM 46717(T)) and NEAU-ML10(T) (=CGMCC 4.7153(T) =DSM 46720(T)), respectively. PMID:25893956

  12. 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

  13. 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

  14. 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 (?, ?, ?, and ?), 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

  15. Isolation and characterization of lipase-producing bacteria in the intestine of the silkworm, Bombyx mori, reared on different forage.

    PubMed

    Feng, Wei; Wang, Xiao-Qiang; Zhou, Wei; Liu, Guang-Ying; Wan, Yong-Ji

    2011-01-01

    The silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), an oligophagous insect that mainly feeds on mulberry leaves, is susceptible to entomopathogen infection when reared with tricuspid cudrania leaves. A total of 56 dominant bacterial strains, classified into 12 phylotypes based on bacteriological properties and analysis of 16S rRNA genes, were isolated from the intestine of the fourth and fifth instar silkworm larvae. Ten and seven phylotypes exist in the intestine of the silkworm larvae reared with mulberry leaves and tricuspid cudrania leaves, respectively. Four of them are common in the intestine of the two treatment groups. By screening their lipolytic ability on a Rhodamine B agar plate, nine lipase-producing bacterial strains were obtained and classified into six genera, including Bacillus, Brevibacterium, Corynebacterium, Staphylococcus, Klebsiella, and Stenotrophomonas. Except for Stenotrophomonas, which is common in both, the other genera only exist in the intestine of the silkworm larvae fed with mulberry leaves. In addition, by culture and fermentation in vitro, the maximum cell density and lipase activity of lipase-producing bacteria were examined at about 48 hours. The results indicate that diet has a significant impact on the gut bacterial community, especially lipase-producing bacteria. We suggest that the difference of lipase-producing bacterial diversity might be related to disease resistance of the silkworm. PMID:22243438

  16. Substrate utilization of stress tolerant methylotrophs isolated from revegetated heavy metal polluted coalmine spoil.

    PubMed

    Giri, D D; Shukla, P N; Ritu, Singh; Kumar, Ajay; Pandey, K D

    2013-04-01

    We analyzed methylotrophs in Bina natural vegetation (BNV), and revegetated overburden dump of four (ROBD4) and 12 years (ROBD12), at Bina coal mine in Sonbhadra district. The cultured strains identified as Pseudomonas, Acinetobacter, Stenotrophomonas and Cellvibrio (?-Proteobacteria), Methylophilus, Ralstonia, Burkholderia (?-Proteobacteria) Methylobacterium and Inquilinus (?-Proteobacteria), Bacillus (Firmicutes) and Flexibacter (Sphingobacteria) in their 16s rRNA gene sequence similarity. The strains differed in citrate, lactose, formate, urea and xylose utilization. Methanol utilization by Stenotrophomonas, Inquilinus, Cellvibrio and Flexibacter is for first time. The preferred N- sources were proline, glutamate and nitrate for most of the strains. All strains tolerated (2.5 % NaCl) and SDS (0.2 %); 16 strains survived in crystal violet (0.01 %) and nine strains in sodium azide (0.02 %. Methylotrophic population trend was BNV > ROBD12 > ROBD4. The presence of majority of strain of BNV at ROBD12 and ROBD4 indicated restoration of soil methylotrophic functional diversity in revegetated dumps. PMID:23184579

  17. 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

  18. 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.

  19. Wounds caused by corn-harvesting machines: an unusual source of infection due to gram-negative bacilli.

    PubMed

    Agger, W A; Cogbill, T H; Busch, H; Landercasper, J; Callister, S M

    1986-01-01

    The infectious complications in 23 patients with mutilating wounds due to trauma during corn harvesting were compared with those in 41 patients with factory-related hand injuries of similar severity. Initial cultures revealed bacterial growth in 89% of the agricultural wounds and in 63% of the factory wounds. A mean of 3.8 initial bacterial species were isolated per corn-harvesting wound vs. 0.9 species per factory wound. Gram-negative rods were recovered from 81% of the agricultural wounds; the commonest of these organisms were Enterobacter species and Xanthomonas maltophilia. Only 7% of factory-wound cultures grew gram-negative rods. Osteomyelitis, all with gram-negative rods, developed in five (22%) of the patients with farm injuries but did not occur in patients with factory wounds. More gram-negative rods were recovered from environmental cultures of corn-harvesting machines and corn plants than from those of factory machinery. PMID:3797937

  20. Patterns of oral bacterial infection in captive snakes.

    PubMed

    Draper, C S; Walker, R D; Lawler, H E

    1981-12-01

    The bacterial isolates from culture specimens of snakes with infectious stomatitis were compared with those from culture specimens of the oral cavity of healthy captive snakes. Cloacal swab specimens were also taken from healthy snakes to compare their intestinal and oral bacterial populations. The healthy snakes had a predominantly gram-positive oral flora, with Corynebacterium spp and coagulase-negative Staphylococcus spp being the organisms isolated most frequently. The specimens from snakes with infectious stomatitis yielded predominantly gram-negative bacteria. The organisms most frequently isolated from these specimens were Pseudomonas aeruginosa, Providencia rettgeri, and P maltophilia. The cloacal swabbing of healthy snakes also resulted in the isolation of predominantly gram-negative organisms, suggesting that these bacteria are not exogenous pathogens but opportunistic invaders. PMID:7328007

  1. 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.

  2. 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-X12T, 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-X12T were non-spore-forming rods, 0.4-0.7??m wide, 2.1-3.2??m long and motile with a single polar flagellum. Strain XCD-X12T 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?:?1?9c and C18?:?1?9c. 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-X12T was associated with the genus Marinobacter, and showed the highest 16S rRNA gene sequence similarity to Marinobacter hydrocarbonoclasticus ATCC 49840T (97.4?%), M. vinifirmus FB1T (96.8?%), M. excellens KMM 3809T (96.8?%) and M. antarcticus ZS2-30T (96.7?%). DNA-DNA relatedness of strain XCD-X12T to M. hydrocarbonoclasticus CGMCC 1.7683T was 34?±?5?%. Based on these data, it is concluded that strain XCD-X12T represents a novel species of the genus Marinobacter, for which the name Marinobacter halophilus sp. nov. is proposed. The type strain is XCD-X12T (?=?CGMCC 1.12481T?=?JCM 30472T). PMID:25985830

  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?:?1?7c and C16?:?1?7c and/or C16?:?1?6c 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. 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

  5. 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.

  6. Carbon utilization profiles of bacteria colonizing the headbox water of two paper machines in a Canadian mill.

    PubMed

    Kashama, Johnny; Prince, Véronique; Simao-Beaunoir, Anne-Marie; Beaulieu, Carole

    2009-03-01

    Forty-one bacterial strains isolated from the headbox water of two machines in a Canadian paper mill were associated with the genera Asticcacaulis, Acidovorax, Bacillus, Exiguobacterium, Hydrogenophaga, Pseudomonas, Pseudoxanthomonas, Staphylococcus, Stenotrophomonas based on the sequence of their 16S rRNA genes. The metabolic profile of these strains were determined using Biolog EcoPlate, and the bacteria were divided into four metabolic groups. Metabolic profiles of the bacterial communities colonizing the headbox water of two paper machines was also determined weekly over a 1 year period. The only compound that was not reduced by the bacterial community was 2-hydroxybenzoic acid. Utilization frequency of the other carbon sources in the Biolog EcoPlate ranged from 3 to 100%. The metabolic profiles of the bacterial community did not vary considerably between the two paper machines. However, the metabolic profile varied among the sampling dates. PMID:19137341

  7. 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

  8. 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

  9. Nosocomial Infections: Multicenter surveillance of antimicrobial resistance profile of Staphylococcus aureus and Gram negative rods isolated from blood and other sterile body fluids in Iran

    PubMed Central

    Poorabbas, Bahman; Mardaneh, Jalal; Rezaei, Zahra; Kalani, Mehdi; Pouladfar, Gholamreza; Alami, Mohammad Hasan; Soltani, Jafar; Shamsi-Zadeh, Ahmad; Abdoli-Oskooi, Shahram; Saffar, Mohammed Jafar; Alborzi, Abdolvahab

    2015-01-01

    Background and Objective: Antibiotic resistance is increasing, especially in healthcare-associated infections causing significant public health concerns worldwide. National information is required to make appropriate policies, update list of essential drugs for treatment, and evaluate the effects of intervention strategies. A nationwide surveillance of antimicrobial resistant bacteria in nosocomial infections was established in Iran in 2008, so that the data obtained through the surveillance would enable us to construct a database. Materials and Methods: Seven major teaching hospitals in Shiraz, Tabriz, Sari, Mashhad, Sanandaj, Ahwaz and Isfahan participated in this study. A total of 858 strains isolated from blood and other sterile body fluids were tested. Identification at the species level was performed with conventional biochemical methods and the API system. Susceptibility tests were done using disk diffusion method. The methicillin-resistance in S. aureus (MRSA) was determined by the oxacillin agar screen plate and respective MIC values were assessed using the E-test strips. The confirmatory disk diffusion methods were applied for phenotypic identification of extended-spectrum ?- lactamase (ESBL) production for E. coli and K. pneumoniae, according to CLSI guidelines. Results: Cultivation and re-identification of the strains yielded 858 isolates, consisting of 224 S. aureus, 148 Klebsiella spp., 105 Serratia spp., 146 E. coli, 67 Acinetobacter spp., 38 Enterobacter spp., 95 Pseudomonas spp., 71 P.aeruginosa. 35 Stenotrophomonas sp., and 8 other organisms. MRSA was detected in 37.5% of the isolates. No vancomycin-resistant or vancomycin-intermediate resistant S. aureus was detected. With the exception of Acinetobacter and Stenotrophomonas, 85% of the Gram-negative isolates were found to be susceptible in vitro to imipenem. Overall, about 61% of K. pneumoniae and 35% of E. coli isolates were ESBL producing. Conclusion: Multidrug resistant isolates of Gram-negative organisms and methicillin-resistant strains of S. aureus have been detected in many hospitals in this study. PMID:26668699

  10. Isolation and characterization of plant growth-promoting rhizobacteria from wheat rhizosphere and their effect on plant growth promotion.

    PubMed

    Majeed, Afshan; Abbasi, M Kaleem; Hameed, Sohail; Imran, Asma; Rahim, Nasir

    2015-01-01

    The present study was conducted to characterize the native plant growth promoting (PGP) bacteria from wheat rhizosphere and root-endosphere in the Himalayan region of Rawalakot, Azad Jammu and Kashmir (AJK), Pakistan. Nine bacterial isolates were purified, screened in vitro for PGP characteristics and evaluated for their beneficial effects on the early growth of wheat (Triticum aestivum L.). Among nine bacterial isolates, seven were able to produce indole-3- acetic acid in tryptophan-supplemented medium; seven were nitrogen fixer, and four were able to solubilize inorganic phosphate in vitro. Four different morphotypes were genotypically identified based on IGS-RFLP fingerprinting and representative of each morphotype was identified by 16S rRNA gene sequencing analysis except Gram-positive putative Bacillus sp. Based on 16S rRNA gene sequence analysis, bacterial isolates AJK-3 and AJK-9 showing multiple PGP-traits were identified as Stenotrophomonas spp. while AJK-7 showed equal homologies to Acetobacter pasteurianus and Stenotrophomonas specie. Plant inoculation studies indicated that these Plant growth-promoting rhizobacteria (PGPR) strains provided a significant increase in shoot and root length, and shoot and root biomass. A significant increase in shoot N contents (up to 76%) and root N contents (up to 32%) was observed over the un-inoculated control. The study indicates the potential of these PGPR for inoculums production or biofertilizers for enhancing growth and nutrient content of wheat and other crops under field conditions. The study is the first report of wheat associated bacterial diversity in the Himalayan region of Rawalakot, AJK. PMID:25852661

  11. Isolation and characterization of plant growth-promoting rhizobacteria from wheat rhizosphere and their effect on plant growth promotion

    PubMed Central

    Majeed, Afshan; Hameed, Sohail; Imran, Asma; Rahim, Nasir

    2015-01-01

    The present study was conducted to characterize the native plant growth promoting (PGP) bacteria from wheat rhizosphere and root-endosphere in the Himalayan region of Rawalakot, Azad Jammu and Kashmir (AJK), Pakistan. Nine bacterial isolates were purified, screened in vitro for PGP characteristics and evaluated for their beneficial effects on the early growth of wheat (Triticum aestivum L.). Among nine bacterial isolates, seven were able to produce indole-3- acetic acid in tryptophan-supplemented medium; seven were nitrogen fixer, and four were able to solubilize inorganic phosphate in vitro. Four different morphotypes were genotypically identified based on IGS-RFLP fingerprinting and representative of each morphotype was identified by 16S rRNA gene sequencing analysis except Gram-positive putative Bacillus sp. Based on 16S rRNA gene sequence analysis, bacterial isolates AJK-3 and AJK-9 showing multiple PGP-traits were identified as Stenotrophomonas spp. while AJK-7 showed equal homologies to Acetobacter pasteurianus and Stenotrophomonas specie. Plant inoculation studies indicated that these Plant growth-promoting rhizobacteria (PGPR) strains provided a significant increase in shoot and root length, and shoot and root biomass. A significant increase in shoot N contents (up to 76%) and root N contents (up to 32%) was observed over the un-inoculated control. The study indicates the potential of these PGPR for inoculums production or biofertilizers for enhancing growth and nutrient content of wheat and other crops under field conditions. The study is the first report of wheat associated bacterial diversity in the Himalayan region of Rawalakot, AJK. PMID:25852661

  12. Wastewater Irrigation Increases the Abundance of Potentially Harmful Gammaproteobacteria in Soils in Mezquital Valley, Mexico

    PubMed Central

    Broszat, Melanie; Nacke, Heiko; Blasi, Ronja; Siebe, Christina; Huebner, Johannes; Daniel, Rolf

    2014-01-01

    Wastewater contains large amounts of pharmaceuticals, pathogens, and antimicrobial resistance determinants. Only a little is known about the dissemination of resistance determinants and changes in soil microbial communities affected by wastewater irrigation. Community DNAs from Mezquital Valley soils under irrigation with untreated wastewater for 0 to 100 years were analyzed by quantitative real-time PCR for the presence of sul genes, encoding resistance to sulfonamides. Amplicon sequencing of bacterial 16S rRNA genes from community DNAs from soils irrigated for 0, 8, 10, 85, and 100 years was performed and revealed a 14% increase of the relative abundance of Proteobacteria in rainy season soils and a 26.7% increase in dry season soils for soils irrigated for 100 years with wastewater. In particular, Gammaproteobacteria, including potential pathogens, such as Pseudomonas, Stenotrophomonas, and Acinetobacter spp., were found in wastewater-irrigated fields. 16S rRNA gene sequencing of 96 isolates from soils irrigated with wastewater for 100 years (48 from dry and 48 from rainy season soils) revealed that 46% were affiliated with the Gammaproteobacteria (mainly potentially pathogenic Stenotrophomonas strains) and 50% with the Bacilli, whereas all 96 isolates from rain-fed soils (48 from dry and 48 from rainy season soils) were affiliated with the Bacilli. Up to six types of antibiotic resistance were found in isolates from wastewater-irrigated soils; sulfamethoxazole resistance was the most abundant (33.3% of the isolates), followed by oxacillin resistance (21.9% of the isolates). In summary, we detected an increase of potentially harmful bacteria and a larger incidence of resistance determinants in wastewater-irrigated soils, which might result in health risks for farm workers and consumers of wastewater-irrigated crops. PMID:24951788

  13. Characterization of Co(III) EDTA-Reducing Bacteria in Metal- and Radionuclide-Contaminated Groundwater

    SciTech Connect

    Gao, Weimin; Gentry, Terry J; Mehlhorn, Tonia L; Carroll, Sue L; Jardine, Philip M; Zhou, Jizhong

    2010-01-01

    The Waste Area Grouping 5 (WAG5) site at Oak Ridge National Laboratory has a potential to be a field site for evaluating the effectiveness of various bioremediation approaches and strategies. The site has been well studied in terms of its geological and geochemical properties over the past decade. However, despite the importance of microorganisms in bioremediation processes, the microbiological populations at the WAG5 site and their potential in bioremediation have not been similarly evaluated. In this study, we initiated research to characterize the microbial populations in WAG5 groundwater. Approximately 100 isolates from WAG5 groundwater were isolated and selected based on colony morphology. Fifty-five unique isolates were identified by BOX-PCR and subjected to further characterization. 16S rRNA sequences indicated that these isolates belong to seventeen bacterial genera including Alcaligenes (1 isolate), Aquamonas (1), Aquaspirillum (1), Bacillus (10), Brevundimonas (5), Caulobacter (7), Dechloromonas (2), Janibacter (1), Janthinobacterium (2), Lactobacillus (1), Paenibacillus (4), Pseudomonas (9), Rhodoferax (1), Sphingomonas (1), Stenotrophomonas (6), Variovorax (2), and Zoogloea (1). Metal respiration assays identified several isolates, which phylogenically belong or are close to Caulobacter, Stenotrophomonas, Bacillus, Paenibacillus and Pseudomonas, capable of reducing Co(III)EDTA- to Co(II)EDTA{sup 2-} using the defined M1 medium under anaerobic conditions. In addition, using WAG5 groundwater directly as the inoculants, we found that organisms associated with WAG5 groundwater can reduce both Fe(III) and Co(III) under anaerobic conditions. Further assays were then performed to determine the optimal conditions for Co(III) reduction. These assays indicated that addition of various electron donors including ethanol, lactate, methanol, pyruvate, and acetate resulted in metal reduction. These experiments will provide useful background information for future bioremediation field experiments at the WAG5 site.

  14. A novel non-hydrolytic protein from Pseudomonas oryzihabitans enhances the enzymatic hydrolysis of cellulose.

    PubMed

    Qin, Yi-Min; Tao, Heng; Liu, You-Yan; Wang, Yan-Dong; Zhang, Jing-Ru; Tang, Ai-Xing

    2013-10-10

    Several kinds of protein such as the expansin, expansin-like proteins and LPMOs (lytic polysaccharide monooxygenases) are known to exert enhancement effects on cellulase activity. In this study, a novel cellulase synergistic protein named POEP1 was purified from the culture filtrate of Pseudomonas oryzihabitans CGMCC 6169, and was homogeneous on SDS-PAGE with a molecular weight of 60kDa. Mass spectrometry analysis indicated that it was an unknown protein without sequence similarity to the expansin and expansin-like proteins. Evaluation of the enzymatic hydrolysis of filter paper revealed that POEP1 had no cellulase activity but displayed high synergistic activity of 364% at a cellulase concentration of 0.1FPU/g of filter paper. When a mixture containing 0.6FPU cellulase and 700?g POEP1 per g of cellulose was evaluated, the maximal sugar yield was achieved, which was 2.2-fold greater than that with the cellulase alone. POEP1 was found to have functional similarity to the expansin and expansin-like proteins, which could decrease both the hydrogen-bond intensity and crystallinity, and cause the filter paper disruption. This study provided evidence for the existence of novel bacterial proteins in nature serving the same function as expansin and expansin-like proteins. PMID:23916949

  15. Halorubrum rutilum sp. nov. isolated from a marine solar saltern.

    PubMed

    Yin, Shuai; Wang, Zhao; Xu, Jia-Qi; Xu, Wen-Mei; Yuan, Pan-Pan; Cui, Heng-Lin

    2015-12-01

    A halophilic archaeal strain, YJ-18-S1(T), was isolated from Yangjiang marine solar saltern, Guangxi Province, China. Cells were pleomorphic, stained Gram-negative and formed red-pigmented colonies on agar plates. Strain YJ-18-S1(T) was able to grow at 20-55 °C (optimum 37 °C), at 0.9-4.8 M NaCl (optimum 2.6 M NaCl), at 0.005-1.0 M MgCl2 (optimum 0.3 MgCl2) and at pH 5.5-8.5 (optimum pH 7.0). The cells were lysed in distilled water, and the minimal NaCl concentration to prevent cell lysis was found to be 5 % (w/v). The major polar lipids of the strain were phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and sulfated mannosyl glucosyl diether. The 16S rRNA gene and rpoB' gene of strain YJ-18-S1(T) were phylogenetically related to the corresponding genes of Halorubrum members (94.3-98.0 and 86.7-96.1 % similarities, respectively). The DNA G+C content of strain YJ-18-S1(T) was 66.2 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YJ-18-S1(T) (=CGMCC 1.12554(T) = JCM 30030(T)) represents a new species of Halorubrum, for which the name Halorubrum rutilum sp. nov. is proposed. PMID:26438378

  16. Micromonospora vulcania sp. nov., isolated from volcanic sediment.

    PubMed

    Jia, Feiyu; Liu, Chongxi; Zhou, Shuyu; Li, Jiansong; Shen, Yue; Guan, Xuejiao; Guo, Siyu; Gao, Meiyue; Wang, Xiangjing; Xiang, Wensheng

    2015-12-01

    A novel actinobacterial strain, designated strain NEAU-JM2(T), was isolated from volcanic sediment collected from Longwan, Jilin province, north China and characterized using a polyphasic approach. The strain was found to have morphological and chemotaxonomic characteristics typical of the members of the genus Micromonospora. Phylogenetic analysis of the16S rRNA gene sequence also indicated that strain NEAU-JM2(T) should be classified in the genus Micromonospora and showed that close relatives are Micromonospora maoerensis NEAU-MES19(T) (99.5 %) and Micromonospora matsumotoense JCM 9104(T) (98.8 %). However, phylogenetic analysis based on the gyrB gene sequence showed that the isolate forms a separate subclade away from the close relatives in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. The low level of DNA-DNA relatedness allowed the isolate to be differentiated from M. maoerensis NEAU-MES19(T) and M. matsumotoense JCM 9104(T). Furthermore, strain NEAU-JM2(T) could also be distinguished from its close phylogenetic relatives by cultural and physiological characteristics. Therefore, it is proposed that strain NEAU-JM2(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora vulcania sp. nov. is proposed. The type strain is NEAU-JM2(T) (=CGMCC 4.7144(T) = DSM 46711(T)). PMID:26404428

  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 ?7c and C16:1 ?7c 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. Thiobacimonas profunda gen. nov., sp. nov., a member of the family Rhodobacteraceae isolated from deep-sea water.

    PubMed

    Li, Shuhui; Tang, Kai; Liu, Keshao; Jiao, Nianzhi

    2015-02-01

    A bacterial strain, JLT2016(T), was isolated from a sample of South-eastern Pacific deep-sea water. Cells were Gram-stain-negative, aerobic, devoid of flagella, motile by gliding and rod-shaped. Colonies were mucoid and cream. Growth occurred at 1.0-11.0 % (w/v) NaCl, 10-40 °C and pH 4.0-9.0. The major fatty acids were summed feature 8 (C18 : 1?7c and/or C18 : 1?6c) (60.5 %), C19 : 0 cyclo ?8c (10.9 %) and C16 : 0 (9.0 %). The polar lipids included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and two sphingoglycolipids. The DNA G+C content was 67.1 mol%. The closest relative of strain JLT2016(T) was Salipiger mucosus A3(T) (96.7 % 16S rRNA gene sequence similarity). The results of phylogenetic analyses with different treeing algorithms indicated that this strain belonged to the Roseobacter clade in the order Rhodobacterales. Based on polyphasic analysis, strain JLT2016(T) is considered to represent a novel genus and species, for which the name Thiobacimonas profunda gen. nov., sp. nov. is proposed. The type strain is JLT2016(T) (?= LMG 27365(T)?= CGMCC 1.12377(T)). PMID:25355706

  19. Arenitalea lutea gen. nov., sp. nov., a marine bacterium of the family Flavobacteriaceae isolated from intertidal sand.

    PubMed

    Zhang, Xi-Ying; Liu, Ang; Liu, Chang; Li, Hai; Li, Guo-Wei; Xu, Zhong; Chen, Xiu-Lan; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2013-08-01

    A yellow, rod-shaped, Gram-negative, facultatively aerobic, gliding bacterium, designed strain P7-3-5(T), was isolated from intertidal sand of the Yellow Sea, China. Analysis of 16S rRNA gene sequences revealed that strain P7-3-5(T) formed a distinct lineage within the family Flavobacteriaceae, sharing 94.2-96.9 % sequence similarity with type strains of species of the most closely related genera, including Hyunsoonleella, Jejuia, Marinivirga and Algibacter. The strain grew at 4-40 °C and with 0.5-5.0 % (w/v) NaCl. It reduced nitrate to nitrite and hydrolysed gelatin and DNA. The major cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G and anteiso-C15 : 0 and the major respiratory quinone was MK-6. Polar lipids included phosphatidylethanolamine (PE), three unidentified aminolipids (AL1-3) and four unidentified lipids (L1-4). The genomic DNA G+C content of strain P7-3-5(T) was 32.1 mol%. Data from this polyphasic study suggest that strain P7-3-5(T) represents a novel species in a new genus in the family Flavobacteriaceae, for which the name Arenitalea lutea gen. nov., sp. nov. is proposed. The type strain of Arenitalea lutea is P7-3-5(T) ( = CGMCC 1.12213(T) = KACC 16457(T)). PMID:23315415

  20. Rhizobium anhuiense sp. nov., isolated from effective nodules of Vicia faba and Pisum sativum.

    PubMed

    Zhang, Yu Jing; Zheng, Wen Tao; Everall, Isobel; Young, J Peter W; Zhang, Xiao Xia; Tian, Chang Fu; Sui, Xin Hua; Wang, En Tao; Chen, Wen Xin

    2015-09-01

    Four rhizobia-like strains, isolated from root nodules of Pisum sativum and Vicia faba grown in Anhui and Jiangxi Provinces of China, were grouped into the genus Rhizobium but were distinct from all recognized species of the genus Rhizobium by phylogenetic analysis of 16S rRNA and housekeeping genes. The combined sequences of the housekeeping genes atpD, recA and glnII for strain CCBAU 23252T showed 86.9 to 95?% similarity to those of known species of the genus Rhizobium. All four strains had nodC and nifH genes and could form effective nodules with Pisum sativum and Vicia faba, and ineffective nodules with Phaseolus vulgaris, but did not nodulate Glycine max, Arachis hypogaea, Medicago sativa, Trifolium repens or Lablab purpureus in cross-nodulation tests. Fatty acid composition, DNA-DNA relatedness and a series of phenotypic tests also separated these strains from members of closely related species. Based on all the evidence, we propose a novel species, Rhizobium anhuiense sp. nov., and designate CCBAU 23252T (?=?CGMCC 1.12621T?=?LMG 27729T) as the type strain. This strain was isolated from a root nodule of Vicia faba and has a DNA G+C content of 61.1?mol% (Tm). PMID:26025940

  1. Bacillus taiwanensis sp. nov., isolated from a soil sample from Taiwan.

    PubMed

    Liu, Bo; Liu, Guo-Hong; Sengonca, Cetin; Schumann, Peter; Wang, Ming-Kuang; Xiao, Rong-Feng; Zheng, Xue-Fang; Chen, Zheng

    2015-07-01

    A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterium (FJAT-14571(T)) was isolated from a soil sample in Taiwan. Strain FJAT-14571(T) grew at 20-40 °C (optimum 35 °C), pH 6-10 (optimum pH?8) and 0-2% (w/v) NaCl (optimum 0%). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain FJAT-14571(T) was a member of the genus Bacillus and was most closely related to Bacillus oceanisediminis DSM 24771(T) (96.2%). DNA-DNA relatedness between strain FJAT-14571(T) and B. oceanisediminis DSM 24771(T) was low (32.0% ± 0.88%). The diagnostic diamino acid of the peptidoglycan of strain FJAT-14571(T) was meso-diaminopimelic acid and the predominant menaquinone was MK-7 (96.6%). The major cellular fatty acids were iso-C15 : 0 (46.4%), anteiso-C15 : 0 (7.6%), iso-C17 : 0 (8.2%) and iso-C16 : 0 (10.0 %) and the DNA G+C content was 40.8 mol%. Phenotypic, chemotaxonomic and genotypic properties clearly indicated that strain FJAT-14571(T) represents a novel species within the genus Bacillus, for which the name Bacillus taiwanensis sp. nov. is proposed. The type strain is FJAT-14571(T) (?= DSM 27845(T) = CGMCC1.1 2698(T)). PMID:25829330

  2. Pullulanibacillus pueri sp. nov., isolated from Pu'er tea.

    PubMed

    Niu, Lili; Tang, Tianyi; Song, Lei; Xiong, Mengjie; Tian, Jianqing; Zhang, Kegui; Hu, Xing; Zhu, Daochen

    2015-07-01

    A novel Gram-stain-positive, aerobic, endospore-forming, rod-shaped bacterial strain YN3(T) was isolated from ripened Pu'er tea. Phylogenetic analysis of 16S rRNA gene sequences showed that the strain belonged to the family Sporolactobacillaceae and was closely related to Pullulanibacillus naganoensis DSM 10191(T) (95.8% 16S rRNA gene sequence similarity) and Pullulanibacillus uraniitolerans DSM 19429(T) (95.4%). Growth of the strain was observed at 20-50 °C (optimum 30-37 °C), at pH 4.0-8.0 (optimum pH 5.0-6.0). The strain had a cell-wall type A1? peptidoglycan with meso-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinone was menaquinone-7 (MK-7). The major fatty acids were anteiso-C15:0, anteiso-C17:0 and C18:1?7c. The DNA G+C content of strain YN3(T) was 38.7 mol%. Strain YN3(T) could be differentiated from recognized species of the genus Pullulanibacillus based on phenotypic characteristics, chemotaxonomic differences, phylogenetic analysis and DNA-DNA hybridization data. On the basis of polyphasic evidence from this study, Pullulanibacilluspueri sp. nov., is proposed, with strain YN3(T) (?= CGMCC 1.12777(T ) = JCM 30075(T)) as the type strain. PMID:25858244

  3. Tumebacillus algifaecis sp. nov., isolated from decomposing algal scum.

    PubMed

    Wu, Yu-Fan; Zhang, Bo; Xing, Peng; Wu, Qing-Long; Liu, Shuang-Jiang

    2015-07-01

    Bacterial strain THMBR28(T) was isolated from decomposing algal scum that was collected during an algal bloom in Taihu lake, China. Cells of strain THMBR28(T) were Gram-staining-positive, facultatively anaerobic and rod-shaped. Growth was observed at 20-45 °C (optimum, 30 °C), at pH 5.0-9.5 (optimum, pH 6.5-7.5), and in the presence of 0-1.0% (w/v) NaCl (optimum, 0.5%). Strain THMBR28(T) contained MK-7 as the major menaquinone and iso-C15 : 0 as the major cellular fatty acid. The polar lipid profile contained phosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine and six unidentified polar lipids. The diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid. The DNA G+C content was 57.6 mol% (Tm). Phylogenetic analysis of 16S rRNA gene sequences showed that strain THMBR28(T) belonged to the genus Tumebacillus, most closely related to Tumebacillus ginsengisoli DSM 18389(T) (95.0%) and Tumebacillus permanentifrigoris Eur1 9.5(T) (93.4%). Based on phylogenetic and phenotypic characterization, it is concluded that strain THMBR28(T) represents a novel species of the genus Tumebacillus, for which the name Tumebacillus algifaecis sp. nov. is proposed, with THMBR28(T) (?= CGMCC 1.10949(T) = NBRC 108765(T)) as the type strain. PMID:25858243

  4. 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 (C16:1?7c and/or iso-C15:0 2-OH) (57.31%), C16:0 (11.46%) and C18:1?7c (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

  5. Streptomyces kanasensis sp. nov., an Antiviral Glycoprotein Producing Actinomycete Isolated from Forest Soil Around Kanas Lake of China.

    PubMed

    Han, Lirong; Zhang, Guoqiang; Miao, Guopeng; Zhang, Xing; Feng, Juntao

    2015-12-01

    A filamentous actinomycete, designated strain ZX01(T), was isolated from forest soil around Kanas Lake of China. A polyphasic taxonomic study was carried out to establish the status of strain ZX01(T). Chemical and morphological properties of the isolate were similar to those of species of the genus Streptomyces. Analysis of the almost complete 16S rRNA gene sequence placed strain ZX01(T) in the genus Streptomyces where it formed a distinct phyletic line with recognized species of this genus. The strain exhibited the highest sequence similarities to Streptomyces lavendofoliae NBRC 12882(T) (99.1 %), S. luridus NBRC 12793(T) (99.0 %), S. lavendulocolor NBRC 12881(T) (99.0 %), S. gobitricini NBRC 15419(T) (99.0 %), and S. roseolilacinus NBRC 12815(T) (98.9 %). Low DNA-DNA relatedness values of 54.0, 50.0, 60.0, 66.7, and 50.4 %, respectively, were found between strain ZX01(T) and corresponding strains above. A number of phenotypic properties also enabled the isolate to be differentiated from related species of the genus Streptomyces. Therefore, it is proposed that strain ZX01(T) should be classified as the type strain of a novel species in the genus Streptomyces, Streptomyces kanasensis sp. nov. The type strain is ZX01(T) (= CGMCC 4893(T) =JCM 30232(T)). PMID:26307029

  6. Expression of POX2 gene and disruption of POX3 genes in the industrial Yarrowia lipolytica on the ?-decalactone production.

    PubMed

    Guo, Yanqiong; Song, Huanlu; Wang, Zhaoyue; Ding, Yongzhi

    2012-04-20

    The yeast Yarrowia lipolytica growing on methyl ricinoleate can produce ?-decalactone, the worthy aroma compound, which can exhibit fruity and creamy sensorial notes, and recognized internationally as a safe food additive. Unfortunately, the yield is poor because of lactone degradation by enzyme Aox3 (POX3 gene encoded), which was responsible for continuation of oxidation after C(10) level and lactone reconsumption. In this paper, we chose the industrial Y. lipolytica (CGMCC accession number 2.1405), which is the diploid strain as the starting strain and constructed the recombinant strain Tp-12 by targeting the POX3 locus of the wild type, one copy of POX3 was deleted by CRF1+POX2 insertion. The other recombinant strain Tpp-11, which was a null mutant possessing multiple copies of POX2 and disrupted POX3 genes on two chromosomes, was constructed by inserting XPR2+hpt into the other copy of POX3 of Tp-12. The growth ability of the recombinants was changed after genetic modification in the fermentation medium. The production of ?-decalactone was increased, resulting from blocking ?-oxidation at the C(10) Aox level and POX2 overexpression. The recombinant strain Tpp-11 was stable. Because there was no reconsumption of ?-decalactone, the mutant strain could be grown in continuous fermentation of methyl ricinoleate to produce ?-decalactone. PMID:22115771

  7. Deinococcus gobiensis sp. nov., an extremely radiation-resistant bacterium.

    PubMed

    Yuan, Menglong; Zhang, Wei; Dai, Shiming; Wu, Jing; Wang, Yingdian; Tao, Tianshen; Chen, Ming; Lin, Min

    2009-06-01

    A Gram-positive, non-motile, spherical, red-pigmented and facultatively anaerobic bacterium, designated strain I-0(T), was isolated from a sand sample of the Gobi desert in Xinjiang Autonomous Region, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that this isolate represents a novel member of the genus Deinococcus, with low sequence similarities (<94 %) to recognized Deinococcus species. The major cellular fatty acids were C(16 : 1)omega7c and C(16 : 0). Its polar lipid profile contained several unidentified glycolipids, phosphoglycolipids, phospholipids, pigments and an aminophospholipid. The peptidoglycan type was Orn-Gly(2) (A3beta) and the predominant respiratory quinone was MK-8. The DNA G+C content was 65.4 mol%. DNA-DNA relatedness between strain I-0(T) and Deinococcus radiodurans ACCC 10492(T) was 37 %. The strain was shown to be extremely resistant to gamma radiation (>15 kGy) and UV light (>600 J m(-2)). On the basis of the phylogenetic, chemotaxonomic and phenotypic data presented, strain I-0(T) represents a novel species of the genus Deinococcus, for which the name Deinococcus gobiensis sp. nov. is proposed. The type strain is I-0(T) (=DSM 21396(T) =CGMCC 1.7299(T)). PMID:19502345

  8. Synergistic effect using vermiculite as media with a bacterial biofilm of Arthrobacter sp. for biodegradation of di-(2-ethylhexyl) phthalate.

    PubMed

    Wen, Zhi-Dan; Wu, Wei-Min; Ren, Nan-Qi; Gao, Da-Wen

    2016-03-01

    Vermiculite is one of matrix material used for constructed wetland (CW) for the treatment of municipal wastewater. Arthrobacter sp. strain C21 (CGMCC No. 7671), isolated from a constructed wetland receiving municipal wastewater, forms biofilm on the surface of vermiculite. Di-(2-ethylhexyl) phthalate (DEHP), a typical phthalate pollutant in environment, can be degraded by the biofilm of strain C21 formed on vermiculite. Results of laboratory studies indicated that DEHP was removed from aqueous phase via biodegradation, adsorption by vermiculite, and adsorption by biofilm biomass. Synergistic effect of these three reactions enhanced the overall DEHP removal efficiency. During a batch incubation test with vermiculite and the cell suspension, bacterial adhesion to the media surface occurred within 5h and the phthalate esters (PEs) removal was due to both biodegradation and vermiculite adsorption. As the biofilm developed on surface of vermiculite (5-36h), biodegradation became the predominance for PEs removal. As mature biofilm was formed (36-54h), the adsorption of PEs by biofilm biomass became a main driving force for the removal of PEs from aqueous phase. The content of extracellular polymers (EPS) of the biofilm and DEHP removal performance showed a significant positive correlation (rp>0.86). PMID:26547620

  9. Brevundimonas viscosa sp. nov., isolated from saline soil.

    PubMed

    Wang, Jiewei; Zhang, Jianli; Ding, Kai; Xin, Yuhua; Pang, Huancheng

    2012-10-01

    A Gram-negative, rod-shaped bacterial strain, designated F3(T), was isolated from a saline soil sample in China and studied by using a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain F3(T) was affiliated with the genus Brevundimonas, with Brevundimonas kwangchunensis KSL-102(T) (98.4?% similarity) and Brevundimonas alba DSM 4736(T) (98.2?%) as its closest relatives. Strain F3(T) contained ubiquinone-10 (Q-10) as the predominant ubiquinone and C(18?:?1)?7c, C(17?:?1)?8c and C(16?:?0) as the major fatty acids. The DNA G+C content of strain F3(T) was 66.7 mol%. Levels of DNA-DNA relatedness between strain F3(T) and the type strains of closely related Brevundimonas species were below 22?%. On the basis of phenotypic characteristics and genotypic distinctiveness, strain F3(T) should be classified as representing a novel species of the genus Brevundimonas, for which the name Brevundimonas viscosa sp. nov. is proposed. The type strain is F3(T) (?=?CGMCC 1.10683(T)?=?JCM 17426(T)). PMID:22140155

  10. Coralslurrinella hongkonensis gen. nov., sp. nov., a novel bacterium in the family Psychromonadaceae, isolated from the coral Platygyra carnosus.

    PubMed

    Li, Yanxia; Chan, Yuki; Fu, Yingnan; Zhang, Rui; Chiu, Jill M Y

    2013-12-01

    A novel bacterial strain, JLT2006T, was isolated from the scleractinian coral Platygyra carnosus, located in Hong Kong, China. Cells of this strain were Gram-negative, rod-shaped or oval-shaped and motile by the means of polar flagella. They formed faint-yellow, round colonies on marine agar medium. Phylogenetic analyses based on the 16S rRNA gene sequence indicated that the strain JLT2006T belonged to the class Gammaproteobacteria and was most closely related to Alteromonas-like bacteria of the genera Psychromonas, Pseudoalteromonas, Moritella, Shewanella and Ferrimonas, with less than 93 % sequence similarity. The predominant fatty acids were identified as C18:1x7c/C18:1x6c (23.0 %), C16:1x7c/C16:1x6c (18.2 %) and C16:0 (16.4 %). The quinone was menaquinone-7 (100 %). The polar lipids were determined to be phosphatidylglycerol, phosphatidylethanolamine, phospholipid, glycolipid and lipid. The genomic DNA G?C content was 40.3 mol%. Based on the 16S rRNA gene sequence as well as the physiological and biochemical features that separate the strain JLT2006T from other recognized bacteria, a novel species of a new genus with the name Coralslurrinella hongkonensis gen. nov., sp. nov. is proposed. The type strain is JLT2006T (=JCM 18796T = CGMCC 1.10992T). PMID:24022396

  11. Lysobacter arseniciresistens sp. nov., an arsenite-resistant bacterium isolated from iron-mined soil.

    PubMed

    Luo, Guosheng; Shi, Zunji; Wang, Gejiao

    2012-07-01

    A Gram-negative, aerobic, motile, rod-shaped, arsenite [As(III)]-resistant bacterium, designated strain ZS79(T), was isolated from subsurface soil of an iron mine in China. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain ZS79(T) clustered closely with strains of five Lysobacter species, with 96.9, 96.1, 96.0, 95.8 and 95.3% sequence similarities to Lysobacter concretionis Ko07(T), L. daejeonensis GH1-9(T), L. defluvii IMMIB APB-9(T), L. spongiicola KMM 329(T) and L. ruishenii CTN-1(T), respectively. The major cellular fatty acids were iso-C(15:0) (28.6%), iso-C(17:1)?9c (19.9%), iso-C(16:0) (13.6%), iso-C(11:0) (12.6%) and iso-C(11:0) 3-OH (12.4%). The genomic DNA G+C content was 70.7 mol% and the major respiratory quinone was Q-8. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unknown phospholipid. On the basis of morphological and physiological/biochemical characteristics, phylogenetic position and chemotaxonomic data, this strain is considered to represent a novel species of the genus Lysobacter, for which the name Lysobacter arseniciresistens sp. nov. is proposed; the type strain is ZS79(T) (=CGMCC 1.10752(T)=KCTC 23365(T)). PMID:21890727

  12. Youhaiella tibetensis gen. nov., sp. nov., isolated from subsurface sediment.

    PubMed

    Wang, Yun-xiang; Huang, Fa-qi; Nogi, Yuichi; Pang, Shou-Ji; Wang, Ping-kang; Lv, Jie

    2015-07-01

    A Gram-reaction-negative bacterial strain, designated fig4(T), was isolated from a subsurface sediment core of Qiangtang Basin permafrost in China. Cells were catalase- and oxidase-positive and rods. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain fig4(T )was a member of the family Hyphomicrobiaceae and was most closely related to members of the genera Pelagibacterium, Vasilyevaea and Devosia with 93.8-96.2% sequence similarities. The major cellular fatty acids were C16 : 0, C18 : 0, 11-methyl C18 : 1 ?7c, C19 : 0 cyclo ?8c and summed feature 8 (C18 : 1?7c and/or C18 : 1?6c). The major respiratory quinone was Q-10 and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and two unknown glycolipids. The DNA G+C content was 60.7 mol%. Based on the phenotypic, phylogenetic and genotypic data, strain fig4(T) is considered to represent a novel species of a new genus in the family Hyphomicrobiaceae, for which the name Youhaiella tibetensis gen. nov., sp. nov. is proposed. The type strain is fig4(T) (?=?CGMCC 1.12719(T) = JCM 19854(T)). PMID:25829329

  13. Characterization of a novel ?-cypermethrin-degrading Aspergillus niger YAT strain and the biochemical degradation pathway of ?-cypermethrin.

    PubMed

    Deng, Weiqin; Lin, Derong; Yao, Kai; Yuan, Huaiyu; Wang, Zhilong; Li, Jianlong; Zou, Likou; Han, Xinfeng; Zhou, Kang; He, Li; Hu, Xinjie; Liu, Shuliang

    2015-10-01

    Aspergillus niger YAT strain was obtained from Chinese brick tea (Collection number: CGMCC 10,568) and identified on the basis of morphological characteristics and internal transcribed spacer (ITS) sequence. The strain could degrade 54.83 % of ?-cypermethrin (?-CY; 50 mg L(-1)) in 7 days and 100 % of 3-phenoxybenzoic acid (3-PBA; 100 mg L(-1)) in 22 h. The half-lives of ?-CY and 3-PBA range from 3.573 to 11.748 days and from 5.635 to 12.160 h, respectively. The degradation of ?-CY and 3-PBA was further described using first-order kinetic models. The pathway and mechanism of ?-CY degraded by YAT were investigated by analyzing the degraded metabolites through high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). Relevant enzymatic activities and substrate utilization were also investigated. ?-CY degradation products were analyzed. Results indicated that YAT strain transformed ?-CY into 3-PBA. 3-PBA was then gradually transformed into permethric acid, protocatechuic acid, 3-hydroxy-5-phenoxy benzoic acid, gallic acid, and phenol gradually. The YAT strain can also effectively degrade these metabolites. The results indicated that YAT strain has potential applications in bioremediation of pyrethroid insecticide (PI)-contaminated environments and fermented food. PMID:26022858

  14. Sphingomonas psychrolutea sp. nov., a psychrotolerant bacterium isolated from glacier ice.

    PubMed

    Liu, Qing; Liu, Hong-Can; Zhang, Jian-Li; Zhou, Yu-Guang; Xin, Yu-Hua

    2015-09-01

    A Gram-stain-negative, rod-shaped, orange bacterium (strain MDB1-AT) was isolated from ice samples collected from Midui glacier in Tibet, south-west China. Cells were aerobic and psychrotolerant (growth occurred at 0-25?°C). Phylogenetic analysis based on 16S rRNA gene sequences showed that it was a member of the genus Sphingomonas, with its closest relative being Sphingomonas glacialis C16yT (98.9?% similarity). Q-10 was the predominant ubiquinone. C17?:?1?6c and summed feature 8 (C18?:?1?6c and/or C18?:?1?7c) were the major cellular fatty acids. The predominant polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and sphingoglycolipid. The polyamines detected were sym-homospermidine, spermidine and spermine. The G+C content of the genomic DNA was 63.6?%. Based on data from this polyphasic analysis, strain MDB1-AT represents a novel species of the genus Sphingomonas, for which the name Sphingomonas psychrolutea sp. nov. is proposed. The type strain is MDB1-AT (?=?CGMCC 1.10106T?=?NBRC 109639T). PMID:26025946

  15. Fabibacter pacificus sp. nov., a moderately halophilic bacterium isolated from seawater.

    PubMed

    Huo, Ying-Yi; Xu, Lin; Wang, Chun-Sheng; Yang, Jun-Yi; You, Hong; Oren, Aharon; Xu, Xue-Wei

    2013-10-01

    A Gram-stain-negative, aerobic, moderately halophilic bacterium, strain DY53(T), was isolated from a deep-seawater sample collected from the eastern Pacific Ocean. This isolate grew in the presence of 0.5-10.0?% (w/v) NaCl, at pH 6.5-8.5 and at 15-40 °C. The optimum NaCl concentration for growth of DY53(T) was 2?% (w/v) at 35 °C. Chemotaxonomic analysis showed MK-7 as the predominant menaquinone and iso-C15?:?0, summed feature 3 (iso-C15?:?0 2-OH and/or C16?:?1?7c), iso-C15?:?1 G, iso-C15?:?0 3-OH and iso-C17?:?0 3-OH as major cellular fatty acids. The genomic DNA G+C content was 40.8 mol%. Phylogenetic trees based on 16S rRNA gene sequences revealed that Fabibacter halotolerans UST030701-097(T) was the closest neighbour, with 96.7?% sequence similarity. Based on phylogenetic, chemotaxonomic and phenotypic data, we propose that strain DY53(T) represents a novel species of the genus Fabibacter, for which the name Fabibacter pacificus sp. nov. is proposed. The type strain is DY53(T)(?=?CGMCC 1.12402(T)?=?JCM 18885(T)). PMID:23625263

  16. Lentzea guizhouensis sp. nov., a novel lithophilous actinobacterium isolated from limestone from the Karst area, Guizhou, China.

    PubMed

    Cao, Cheng-Liang; Zhou, Xiao-Qi; Qin, Sheng; Tao, Fa-Xiang; Jiang, Ji-Hong; Lian, Bin

    2015-12-01

    A novel filamentous actinobacterium, designated strain DHS C013(T), was isolated from limestone collected in Guizhou Province, South-west China. Morphological and chemotaxonomic characteristics of the strain support its assignment to the genus Lentzea. Phylogenetic analyses showed that strain DHS C013(T) is closely related to Lentzea jiangxiensis FXJ1.034(T) (98.7 % 16S rRNA gene similarity) and Lentzea flaviverrucosa 4.0578(T) (98.0 % 16S rRNA gene similarity), but it can be distinguished from these strains based on low levels of DNA:DNA relatedness (~44 and ~37 %, respectively). Physiological and biochemical tests also allowed phenotypic differentiation of the novel strain from these closely related species. On the basis of the evidence presented here, strain DHS C013(T) is concluded to represent a novel species of the genus Lentzea, for which the name Lentzea guizhouensis sp. nov. is proposed. The type strain is DHS C013(T) (=KCTC 29677(T) = CGMCC 4.7203(T)). PMID:26377575

  17. Phaeocystidibacter marisrubri sp. nov., a member of the family Cryomorphaceae isolated from Red Sea sediment.

    PubMed

    Zheng, Xiaowei; Liu, Hongcan; Song, Lei; Zhang, Limin; Wang, Haina; Dai, Xin; Huang, Li

    2015-07-01

    Strain G18(T), a Gram-stain-negative, aerobic, rod-shaped, motile, non-fermentative, yellow-pigmented bacterium, was isolated from Red Sea sediment. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain G18(T) was most closely related to Phaeocystidibacter luteus PG2S01(T) with 95.3% similarity. Growth of strain G18(T) occurred at 10-42 °C (optimum 28-37 °C), pH 5.0-9.0 (optimum pH 6.0-8.0) and in the presence of 0.5-10% NaCl (optimum 2-5%). The major fatty acids of strain G18(T) were iso-C15 : 0, summed feature 3 (C16 : 1?7c and/or C16 : 1?6c), iso-C15 : 1 G and iso-C17 : 0 3-OH. The major polar lipids were phosphatidylethanolamine, unidentified aminolipids, phospholipids and other lipids. The predominant quinone was menaquinone 6 (MK-6). The G+C content of the genomic DNA from strain G18(T) was 39.0 mol%. Based on the phylogenetic and phenotypic properties, strain G18(T) represents a novel species of the genus Phaeocystidibacter, for which the name Phaeocystidibacter marisrubri sp. nov. is proposed. The type strain is G18(T) (?= CGMCC 1.14954(T)= JCM 30614(T)). PMID:25858241

  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 ?-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. Streptomyces xiaopingdaonensis sp. nov., a novel marine actinomycete isolated from the sediment of Xiaopingdao in Dalian, China.

    PubMed

    Chen, Chao; Feng, Wei-Wei; Qin, Sheng; Zhao, Xin-Qing

    2015-02-01

    A novel streptomycete, designated as strain DUT 180(T), was isolated from a marine sediment sample collected from a sea cucumber farm in Dalian, northeast China. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain DUT 180(T) is phylogenetically affiliated to the genus Streptomyces where it formed a distinct phyletic line with recognized Streptomyces species. Morphological and chemotaxonomic data also supported the affiliation of this isolate to the genus Streptomyces. Strain DUT 180(T) was found to exhibit highest sequence similarities of 99.52 and 99.36 % to Streptomyces halophytocola KLBMP 1284(T) and Streptomyces sulphureus NRRL B-1627(T), respectively. However, strain DUT 180(T) could be distinguished from these two closest neighbours by a range of phenotypic properties. The DNA-DNA hybridization analyses between strain DUT 180(T) and the type strains of the phylogenetic neighbours revealed 54.8 ± 1.4 and 52.4 ± 2.8 % relatedness. Based on the phenotypic, chemotaxonomic and phylogenetic evidence, we suggest that the isolate DUT 180(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces xiaopingdaonensis sp. nov. is proposed, with the type strain DUT 180(T) (= KCTC 29679(T) = CGMCC 4.7208(T)). PMID:25488288

  20. Microbispora bryophytorum sp. nov., an actinomycete isolated from moss (Bryophyta).

    PubMed

    Li, Chuang; Zhang, Yuejing; Liu, Chongxi; Wang, Haiyan; Zhao, Junwei; Li, Lianjie; Zhang, Zhongwen; Wang, Xiangjing; Xiang, Wensheng

    2015-04-01

    A novel endophytic actinomycete, designated strain NEAU-TX2-2(T), was isolated from moss and characterized using a polyphasic approach. The isolate was found to have morphological characteristics typical of the genus Microbispora . The isolate formed longitudinally paired spores on the tips of short sporophores that branched from aerial hyphae. Analysis of the 16S rRNA gene sequence supported the assignment of the novel strain to the genus Microbispora , and strain NEAU-TX2-2(T) exhibited 99.08 and 98.62% gene sequence similarities to Microbispora amethystogenes JCM 3021(T) and Microbispora rosea subsp. rosea JCM 3006(T), respectively. However two tree-making algorithms supported the position that strain NEAU-TX2-2(T) formed a distinct clade with M. rosea subsp. rosea JCM 3006(T). A low level of DNA-DNA relatedness allowed the isolate to be differentiated from M. amethystogenes JCM 3021(T) and M. rosea subsp. rosea JCM 3006(T). Moreover, strain NEAU-TX2-2(T) could also be distinguished from its closest phylogenetic relatives by morphological and physiological characteristics. Therefore, it is proposed that strain NEAU-TX2-2(T) represents a novel species of the genus Microbispora for which the name Microbispora bryophytorum sp. nov. is proposed. The type strain is NEAU-TX2-2(T) (?=?CGMCC 4.7138(T)?=?DSM 46710(T)). PMID:25634944

  1. Plantactinospora veratri sp. nov., an actinomycete isolated from black false hellebore root (Veratrum nigrum L.).

    PubMed

    Xing, He; Liu, Chongxi; Zhang, Yuejing; Zhao, Junwei; Li, Chuang; Liu, Hui; Li, Lianjie; Wang, Xiangjing; Xiang, Wensheng

    2015-06-01

    A novel actinomycete, designated strain NEAU-FHS4T, was isolated from the root of black false hellebore (Veratrum nigrum L.). Strain NEAU-FHS4T formed single spores with smooth surfaces on substrate mycelium. The novel strain contained meso-diaminopimelic as amino acid of the peptidoglycan and xylose and glucose as whole-cell sugars. The predominant menaquinones were MK-10(H6) and MK-10(H8). Mycolic acids were not detected. The diagnostic phospholipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylinositol. The predominant cellular fatty acids were iso-C16 : 0, C16 : 0, C18 : 0 and anteiso-C17 : 0. Phenotypic and chemotaxonomic analysis showed that the novel isolate had characteristics typical of members of the genus Plantactinospora. 16S rRNA gene sequence analysis also indicated that strain NEAU-FHS4T belonged to the genus Plantactinospora, with highest sequence similarities to Plantactinospora mayteni YIM 61359T (98.88 %) and Plantactinospora endophytica YIM 68255T (98.85 %). The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of the novel strain from the most closely related strains. Based on morphological, chemotaxonomic and phylogenetic data, strain NEAU-FHS4T is considered to represent a novel species of the genus Plantactinospora, for which the name Plantactinospora veratri sp. nov. is proposed. The type strain is NEAU-FHS4T (?= CGMCC 4.7143T = DSM 46718T). PMID:25747424

  2. Alcanivorax dieselolei sp. nov., a novel alkane-degrading bacterium isolated from sea water and deep-sea sediment.

    PubMed

    Liu, Chenli; Shao, Zongze

    2005-05-01

    Two bacterial strains, B-5(T) and NO1A, were isolated from the surface water of the Bohai Sea and deep-sea sediment of the east Pacific Ocean, respectively. Both strains were halophilic, aerobic, Gram-negative, non-spore-forming, catalase- and oxidase-positive motile rods. They grew on a restricted spectrum of organic compounds, including some organic acids and alkanes. On the basis of 16S rRNA gene sequence similarity, strains B-5(T) and NO1A were shown to belong to the gamma-Proteobacteria. Highest similarity values were found with Alcanivorax venustensis (95.2 %), Alcanivorax jadensis (94.6 %) and Alcanivorax borkumensis (94.1 %). Principal fatty acids of both strains were C(16 : 0), C(16 : 1)omega7c and C(18 : 1)omega7c. The chemotaxonomically characteristic fatty acid C(19 : 0) cyclo omega8c was also detected. On the basis of the above, together with results of physiological and biochemical tests, DNA-DNA hybridization, comparisons of 16S-23S internal transcribed spacer sequences and comparisons of the partial deduced amino acid sequence of alkane hydroxylase, both strains were affiliated to the genus Alcanivorax but were differentiated from recognized Alcanivorax species. Therefore, a novel species, Alcanivorax dieselolei sp. nov., represented by strains B-5(T) and NO1A is proposed, with the type strain B-5(T) (=DSM 16502(T)=CGMCC 1.3690(T)). PMID:15879252

  3. Understanding of how Propionibacterium acidipropionici respond to propionic acid stress at the level of proteomics

    PubMed Central

    Guan, Ningzi; Shin, Hyun-dong; Chen, Rachel R.; Li, Jianghua; Liu, Long; Du, Guocheng; Chen, Jian

    2014-01-01

    Propionic acid (PA) is an important platform chemical in the food, agriculture, and pharmaceutical industries and is mainly biosynthesized by propionibacteria. Acid tolerance in PA-producing strains is crucial. In previous work, we investigated the acid tolerance mechanism of Propionibacterium acidipropionici at microenvironmental levels by analyzing physiological changes in the parental strain and three PA-tolerant mutants obtained by genome shuffling. However, the molecular mechanism of PA tolerance in P. acidipropionici remained unclear. Here, we performed a comparative proteomics study of P. acidipropionici CGMCC 1.2230 and the acid-tolerant mutant P. acidipropionici WSH1105; MALDI-TOF/MS identified 24 proteins that significantly differed between the parental and shuffled strains. The differentially expressed proteins were mainly categorized as key components of crucial biological processes and the acid stress response. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was used to confirm differential expression of nine key proteins. Overexpression of the secretory protein glyceraldehyde-3-phosphate dehydrogenase and ATP synthase subunit ? in Escherichia coli BL21 improved PA and acetic acid tolerance; overexpression of NADH dehydrogenase and methylmalonyl-CoA epimerase improved PA tolerance. These results provide new insights into the acid tolerance of P. acidipropionici and will facilitate the development of PA production through fermentation by propionibacteria. PMID:25377721

  4. Streptomyces heilongjiangensis sp. nov., a novel actinomycete that produces borrelidin isolated from the root surface of soybean [Glycine max (L.) Merr

    PubMed Central

    Liu, Chongxi; Wang, Xiangjing; Yan, Yijun; Wang, Jidong; Zhang, Bo; Zhang, Ji

    2013-01-01

    A borrelidin-producing actinomycete, designated strain NEAU-W2T, was isolated from the root surface of soybean [Glycine max (L.) Merr] and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of streptomycetes. The G+C content of the DNA was 66.12 mol%. Analysis of the 16S rRNA gene sequence of strain NEAU-W2T revealed that the strain formed a distinct clade within the 16S rRNA gene sequence phylogenetic tree and showed highest similarity (99.61?%) to Streptomyces neyagawaensis ATCC 27449T. However, the DNA–DNA relatedness between strain NEAU-W2T and S. neyagawaensis ATCC 27449T was 58.51?%. Strain NEAU-W2T could also be differentiated from S. neyagawaensis ATCC 27449T and other Streptomyces species showing high 16S rRNA gene sequence similarity (98–99?%), as well as other borrelidin-producing strains, based on morphological and physiological characteristics. On the basis of its physiological and molecular properties, it is proposed that strain NEAU-W2T represents a novel Streptomyces species, Streptomyces heilongjiangensis sp. nov. The type strain is NEAU-W2T (?=?CGMCC 4.7004T ?=?ATCC BAA-2424T ?=?DSM 42073T). PMID:22707527

  5. [Ethanol production from sweet sorghum stalks by advanced solid state fermentation (ASSF) technology].

    PubMed

    Han, Bing; Wang, Li; Li, Shizhong; Wang, Erqiang; Zhang, Lei; Li, Tiancheng

    2010-07-01

    A robust strain of the species Saccharomyces cerevisiae CGMCC1949 was screened and identified, and advanced solid state fermentation (ASSF) technology for fuel ethanol production from sweet sorghum stalks was thus developed. The fermentation time was shortened to less than 30 h, and ethanol yield was 92% of its theoretical maximum. And in the meantime, the cost-effective storage was established for sweet sorghum stalks, with less than 5% sugar loss after 200 days of storage, making the plant operation could extend up to 200 days without feedstock shortage. With the fermentation kinetics and heat-mass transfer models, modeling of the ASSF process was investigated, and the rotating drum bioreactor was designed. Furthermore, the ASSF technology was successfully applied in the pilot plant in which the rotating drum bioreactor was scaled up to 127 m3, and ethanol yield of 91% was achieved. At the end, techno-economic analysis (TEA) conducted by ASPEN indicated that ethanol production from sweet sorghum stalks by the ASSF is economically competitive. PMID:20954398

  6. 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+) (200mM), 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 (3,386,291bp) and a circular plasmid (88,815bp). 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

  7. Genomic sequencing identifies novel Bacillus thuringiensis Vip1/Vip2 binary and Cry8 toxins that have high toxicity to Scarabaeoidea larvae.

    PubMed

    Bi, Yang; Zhang, Yanrui; Shu, Changlong; Crickmore, Neil; Wang, Qinglei; Du, Lixin; Song, Fuping; Zhang, Jie

    2015-01-01

    The Bacillus thuringiensis strain HBF-18 (CGMCC 2070), which has previously been shown to encode the cry8Ga toxin gene, is active against both Holotrichia oblita and Holotrichia parallela. Recombinant Cry8Ga however is only weakly toxic to these insect pests suggesting the involvement of additional toxins in the native strain. We report that through the use of Illumina sequencing three additional, and novel, genes, namely vip1Ad1, vip2Ag1, and cry8-like, were identified in this strain. Although no protein corresponding to these genes could be identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the HBF-18 proteome, reverse transcription (RT)-PCR indicated that all three genes were transcribed in the native strain. The two vip genes were cloned and expressed and, as with other Vip1/2 toxins, appeared to function as a binary toxin and showed strong activity against H. oblita, H. parallela and Anomala corpulenta. This is the first report to demonstrate that the Vip1/Vip2 binary toxin is active against these Scarabaeoidea larvae. The cry8-like gene appeared to be a C-terminally truncated form of a typical cry8 gene and was not expressed in our usual recombinant Bt expression system. When however the missing C-terminal region was replaced with the corresponding sequence from cry8Ea, the resulting hybrid expressed well and the toxin was active against the three test insects. PMID:25081556

  8. Enzymatic hydrolysis and simultaneous saccharification and fermentation of alkali/peracetic acid-pretreated sugarcane bagasse for ethanol and 2,3-butanediol production.

    PubMed

    Zhao, Xuebing; Song, Yuanquan; Liu, Dehua

    2011-09-10

    The enzymatic digestibility of alkali/peracetic acid (PAA)-pretreated bagasse was systematically investigated. The effects of initial solid consistency, cellulase loading and addition of supplemental ?-glucosidase on the enzymatic conversion of glycan were studied. It was found the alkali-PAA pulp showed excellent enzymatic digestibility. The enzymatic glycan conversion could reach about 80% after 24 h incubation when enzyme loading was 10 FPU/g solid. Simultaneous saccharification and fermentation (SSF) results indicated that the pulp could be well converted to ethanol. Compared with dilute acid pretreated bagasse (DAPB), alkali-PAA pulp could obtain much higher ethanol and xylose concentrations. The fermentation broth still showed some cellulase activity so that the fed pulp could be further converted to sugars and ethanol. After the second batch SSF, the fermentation broth of alkali-PAA pulp still kept about 50% of initial cellulase activity. However, only 21% of initial cellulase activity was kept in the fermentation broth of DAPB. The xylose syrup obtained in SSF of alkali-PAA pulp could be well converted to 2,3-butanediol by Klebsiella pneumoniae CGMCC 1.9131. PMID:22112569

  9. "Chemical nose" for the visual identification of emerging ocular pathogens using gold nanostars.

    PubMed

    Verma, Mohit S; Chen, Paul Z; Jones, Lyndon; Gu, Frank X

    2014-11-15

    Ocular pathogens can cause serious damages in the eye leading to severe vision loss and even blindness if left untreated. Identification of pathogens is crucial for administering the appropriate antibiotics in order to gain effective control over ocular infection. Herein, we report a gold nanostar based "chemical nose" for visually identifying ocular pathogens. Using a spectrophotometer and nanostars of different sizes and degrees of branching, we show that the "chemical nose" is capable of identifying the following clinically relevant ocular pathogens with an accuracy of 99%: S. aureus, A. xylosoxidans, D. acidovorans and S. maltophilia. The differential colorimetric response is due to electrostatic aggregation of cationic gold nanostars around bacteria without the use of biomolecule ligands such as aptamers or antibodies. Transmission electron microscopy confirms that the number of gold nanostars aggregated around each bacterium correlates closely with the colorimetric response. Thus, gold nanostars serve as a promising platform for rapid visual identification of ocular pathogens with application in point-of-care diagnostics. PMID:24912040

  10. Detection of Pseudomonas aeruginosa from ovine fleece washings by PCR amplification of 16S ribosomal RNA.

    PubMed

    Kingsford, N M; Raadsma, H W

    1995-11-01

    Two oligonucleotides were selected from the variable regions of the 16S rRNA gene of P. aeruginosa and used as PCR primers for the detection of P. aeruginosa. The specificity of the primers was tested against the following bacterial species; Pseudomonas putida, Pseudomonas cepacia, Xanthamonas maltophilia, Pseudomonas mendocina, Pseudomonas stutzeri, Pseudomonas fluorescens, Pseudomonas alcaligenes and Pseudomonas diminuta. These primers had a sensitivity of detection of 1 pg of chromosomal DNA or 1 x 10(5) cfu/microliters and were species-specific. The sensitivity of detection was increased to 1 fg or less than 10 cfu/microliters using a non-radioactively labelled probe. Using these PCR primers it was possible to detect the presence of P. aeruginosa from fleece washings collected from a flock of 100 sheep. Correlation between single PCR and bacteriological isolation showed agreement in 89% of fleece samples tested, 2% of the samples contained organic PCR inhibitors in the fleece washings, 3% were below the level of sensitivity of the test and the remaining 6% were culture negative for P. aeruginosa but PCR positive. Use of nested PCR did not increase the sensitivity of detection over single round PCR combined with the use of non-radioactively labelled probe. PMID:8604555

  11. Treatment and prevention of relapses of CAPD Pseudomonas peritonitis.

    PubMed

    Pasadakis, P; Thodis, E; Eftimimiadou, A; Panagoutsos, S; Papazoglou, D; Kaliengidou, M; Kartali, S; Vargemezis, V

    1993-01-01

    Pseudomonas peritonitis in continuous ambulatory peritoneal dialysis (CAPD) can be difficult to eradicate, because it is frequently resistant to common antibiotics, inducing the loss of the peritoneal cavity in some cases. A total of 14 episodes of Pseudomonas peritonitis in 12 patients (6 male, 6 female) were treated with intraperitoneal (IP) administration of a combination of ceftazidime and tobramycin. All patients were hospitalized. The loading doses were 1000 mg/2 L of ceftazidime and 1.7 mg/kg of tobramycin, and the maintenance IP doses were 250 mg/2 L of ceftazidime and 16 mg/2 L of tobramycin. The therapy duration was 14 days. In 7 episodes (group A) no other antibiotic regimen was provided, while in the remaining 7 episodes (group B) therapy was continued with 500 mg b.i.d. of oral ciprofloxacin for the next 14 days. Pseudomonas species isolated in group A were P. alcaligenis (1), P. putida (1), P. maltophilia (1), R. cepacia (1), and unidentified (3). In group B the following Pseudomonas species were isolated: P. aeruginosa (4), P. diminuta (1), P. stutszeri (1), and unidentified (1). Recurrence of peritonitis was seen in 4 episodes of group A with 2 catheter removals, while all episodes were cured in group B. These results suggest that IP ceftazidime and tobramycin with the additional use of oral ciprofloxacin is successful in the treatment and prevention of relapses of Pseudomonas peritonitis. PMID:8105925

  12. 60Co-irradiation as an alternate method for sterilization of penicillin G, neomycin, novobiocin, and dihydrostreptomycin

    SciTech Connect

    Tsuji, K.; Rahn, P.D.; Steindler, K.A.

    1983-01-01

    The effects of the use of 60Co-irradiation to sterilize antibiotics were evaluated. The antibiotic powders were only occasionally contaminated with microorganisms. The D-values of the products and environmental isolates were 0.028, 0.027, 0.015, 0.046, 0.15, 0.018, and 0.19 Mrads for Aspergillus species (UC 7297, 7298), A. fumigatus (UC 7299), Rhodotorula species (UC 7300), Penicillium oxalicum (UC 7269), Pseudomonas maltophilia (UC 6855), and a biological indicator microorganism, Bacillus pumilus spores (ATCC 27142). An irradiation dose of 1.14 Mrads, therefore, was sufficient to achieve a six-log cycle destruction of B. pumilus spores. Based on the bioburden data, a minimum irradiation dose of 1.05 Mrads was calculated to be sufficient to obtain a 10(-6) probability of sterilizing the most radioresistant isolate, Pen. oxalicum. To determine the radiolytic degradation scheme and the stability of the antibiotics following irradiation, high-performance liquid chromatographic (HPLC) methods were developed. The resulting rates of degradation for the antibiotics were 0.6, 1.2, 2.3, and 0.95%/Mrad for penicillin G, neomycin, novobiocin, and dihydrostreptomycin, respectively. Furthermore, radiolytic degradation pathways for the antibiotics were identified and found to be similar to those commonly encountered when antibiotics are subjected to acidic, basic, hydrolytic, or oxidative treatments. No radiolytic compounds unique to 60Co-irradiation were found.

  13. The bioactivity of plant extracts against representative bacterial pathogens of the lower respiratory tract

    PubMed Central

    Bocanegra-García, Virgilio; del Rayo Camacho-Corona, María; Ramírez-Cabrera, Mónica; Rivera, Gildardo; Garza-González, Elvira

    2009-01-01

    Background Lower respiratory tract infections are a major cause of illness and death. Such infections are common in intensive care units (ICU) and their lethality persists despite advances in diagnosis, treatment and prevention. In Mexico, some plants are used in traditional medicine to treat respiratory diseases or ailments such as cough, bronchitis, tuberculosis and other infections. Medical knowledge derived from traditional societies has motivated searches for new bioactive molecules derived from plants that show potent activity against bacterial pathogens. Therefore, the aim of this study was to evaluate the effect of hexanic, chloroformic (CLO), methanolic (MET) and aqueous extracts from various plants used in Mexican traditional medicine on various microorganisms associated with respiratory disease. Methods thirty-five extracts prepared from nine plants used in Mexican traditional medicine for the treatment of respiratory infections were evaluated against 15 control bacterial species and clinical isolates. Results Both chloroformic (CLO) and methanolic (MET) extracts of Larrea tridentata were active against Methicillin-resistant S. aureus, B. subtilis and L. monocytogenes. A MET extract of L. tridentata was also active against S. aureus, S. pneumoniae, S. maltophilia, E. faecalis and H. influenzae and the CLO extract was active against A. baumannii. An Aqueous extract of M. acumitata and a MET extract of N. officinale were active against S. pneumoniae. CLO and MET extracts of L. tridentata were active against clinical isolates of S. aureus, S. pneumoniae and E. faecalis. Conclusion Overall, our results support the potential use of L. tridentata as a source of antibacterial compounds. PMID:19486533

  14. Use of ribotyping in epidemiological surveillance of nosocomial outbreaks.

    PubMed Central

    Bingen, E H; Denamur, E; Elion, J

    1994-01-01

    Over the past few years, genotypic methods based on the study of bacterial DNA polymorphism have shown high discriminatory power for strain differentiation and superiority over most phenotypic methods commonly available in the clinical microbiology laboratory. Some of the methods used, however, required either a high level of technology and sophisticated equipment (e.g., pulsed-field gel electrophoresis) or species-specific reagents of restricted availability (randomly cloned DNA probes or gene-specific probes). Because ribotyping uses a universal probe (rRNA) and is a rather simple technology, particularly since the advent of nonradioactive labelling systems, it has been widely used for strain differentiation of most bacterial species involved in nosocomial outbreaks. In vitro and in vivo stability of the markers studied has been demonstrated. Although there may be limitation to this approach, ribotyping was found to be highly discriminative, particularly for typing members of the family Enterobacteriaceae, Pseudomonas cepacia, and Xanthomonas maltophilia. In many cases, it has improved the understanding of the mechanism of nosocomial acquisition of organisms by allowing a distinction between endogenous and exogenous infections. Among exogenous infections, it has distinguished between individual and epidemic strains, thus differentiating cross-infection from independent acquisition. Images PMID:7923052

  15. Halobellus limi sp. nov. and Halobellus salinus sp. nov., isolated from two marine solar salterns.

    PubMed

    Cui, Heng-Lin; Yang, Xin; Zhou, Yu-Guang; Liu, Hong-Can; Zhou, Pei-Jin; Dyall-Smith, Mike L

    2012-06-01

    Two halophilic archaea, strains TBN53(T) and CSW2.24.4(T), were characterized to elucidate their taxonomic status. Strain TBN53(T) was isolated from the Taibei marine solar saltern near Lianyungang city, Jiangsu province, China, whereas strain CSW2.24.4(T) was isolated from a saltern crystallizer in Victoria, Australia. Cells of the two strains were pleomorphic, stained Gram-negative and produced red-pigmented colonies. Strain TBN53(T) was able to grow at 25-55 °C (optimum 45 °C), with 1.4-5.1 M NaCl (optimum 2.6-3.9 M NaCl), with 0-1.0 M MgCl(2) (optimum 0-0.1 M MgCl(2)) and at pH 5.5-9.5 (optimum pH 7.0), whereas strain CSW2.24.4(T) was able to grow at 25-45 °C (optimum 37 °C), with 2.6-5.1 M NaCl (optimum 3.4 M NaCl), with 0.01-0.7 M MgCl(2) (optimum 0.05 M MgCl(2)) and at pH 5.5-9.5 (optimum pH 7.0-7.5). Cells of the two isolates lysed in distilled water. The minimum NaCl concentrations that prevented cell lysis were 8 % (w/v) for strain TBN53(T) and 12 % (w/v) for strain CSW2.24.4(T). The major polar lipids of the two strains were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and phosphatidylglycerol sulfate, with two glycolipids chromatographically identical to sulfated mannosyl glucosyl diether and mannosyl glucosyl diether, respectively. Trace amounts of other unidentified lipids were also detected. On the basis of 16S rRNA gene sequence analysis, strains TBN53(T) and CSW2.24.4(T) showed 94.1 % similarity to each other and were closely related to Halobellus clavatus TNN18(T) (95.0 and 94.7 % similarity, respectively). Levels of rpoB' gene sequence similarity between strains TBN53(T) and CSW2.24.4(T), and between these strains and Halobellus clavatus TNN18(T) were 88.5, 88.5 and 88.1 %, respectively. The DNA G+C contents of strains TBN53(T) and CSW2.24.4(T) were 69.2 and 67.0 mol%, respectively. The level of DNA-DNA relatedness between strain TBN53(T) and strain CSW2.24.4(T) was 25 %, and these two strains showed low levels of DNA-DNA relatedness with Halobellus clavatus TNN18(T) (30 and 29 % relatedness, respectively). Based on these phenotypic, chemotaxonomic and phylogenetic properties, two novel species of the genus Halobellus are proposed to accommodate these two strains, Halobellus limi sp. nov. (type strain TBN53(T) = CGMCC 1.10331(T) = JCM 16811(T)) and Halobellus salinus sp. nov. (type strain CSW2.24.4(T) = DSM 18730(T) = CGMCC 1.10710(T) = JCM 14359(T)). PMID:22661071

  16. Altererythrobacter oceanensis sp. nov., isolated from the Western Pacific.

    PubMed

    Yang, Yanliu; Zhang, Gaiyun; Sun, Zhilei; Cheung, Man Kit; Huang, Cheney

    2014-12-01

    A Gram-stain negative, ovoid-rod shaped, strictly aerobic bacterium, strain Y2(T), was isolated from a deep-sea sediment of the Western Pacific. Phylogenetic and phenotypic properties of the organism indicated that it belongs to the genus Altererythrobacter. Strain Y2(T) shares highest 16S rRNA gene sequence similarity of 96.6 % with Erythrobacter jejuensis CNU001(T), followed by the type strains of recognized members of the genus Altererythrobacter (94.8-96.5 %). Strain Y2(T) forms a clade with E. jejuensis CNU001(T) in the cluster of species of the genus Altererythrobacter. Growth of strain Y2(T) was observed at 4-40 °C (optimum, 35-37 °C), at pH 6.0-10.0 (optimum, pH 7.0-8.0) and in the presence of 0-5 % (w/v) NaCl (optimum, 2-3 %). The major cellular fatty acids were found to be C17:1 ?6c (41.5 %), summed feature 8 (C18:1 ?7c and/or C18:1 ?6c; 17.2 %), C17:1 ?8c (11.0 %) and C15:0 2OH (8.1 %). The major respiratory quinone was determine to be ubiquinone 10 (Q-10). The polar lipid analysis indicated the presence of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, one sphingoglycolipid, three unidentified phospholipids, two unidentified glycolipids, two unidentified aminolipids and three unknown lipids. The DNA G + C content of the type strain is 60.0 mol %. On the basis of the data from the polyphasic characterization, strain Y2(T) represents a novel species, for which the name Altererythrobacter oceanensis sp. nov. is proposed. The type strain is Y2(T) (=CGMCC 1.12752(T) =LMG 28109(T)). PMID:25245787

  17. Celeribacter indicus sp. nov., a polycyclic aromatic hydrocarbon-degrading bacterium from deep-sea sediment and reclassification of Huaishuia halophila as Celeribacter halophilus comb. nov.

    PubMed

    Lai, Qiliang; Cao, Junwei; Yuan, Jun; Li, Fuying; Shao, Zongze

    2014-12-01

    A taxonomic study was carried out on strain P73(T), which was isolated from deep-sea sediment of the Indian Ocean by enrichment of polycyclic aromatic hydrocarbons. The strain was able to degrade biphenyl, naphthalene, 2-methylnaphthalene, 2,6-dimethylnaphthalene, acenaphthene, anthracene, phenanthrene, dibenzothiophene, dibenzofuran, fluorene, 4-methyldibenzothiophene and fluoranthene, but not pyrene or chrysene. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain P73(T) formed a clade with the genera Celeribacter and Huaishuia within the family Rhodobacteraceae, with highest sequence similarity of 96.98?% to Celeribacter neptunius H 14(T), followed by Huaishuia halophila ZXM137(T) (96.42?%). The bacterium was Gram-stain-negative, oxidase- and catalase-positive, rod-shaped and non-motile. Growth was observed at salinities from 0.5 to 12?% and at temperatures from 10 to 41 °C. The principal fatty acids (>10?%) of strain P73(T) were summed feature 8 (C18?:?1?7c/?6c) and C19?:?0?8c cyclo. The sole respiratory quinone was Q-10. The major lipids were phosphatidylglycerol, one unknown aminolipid, one unknown phospholipid and one unknown lipid; a second unknown phospholipid and one unknown glycolipid were present as minor components. The G+C content of the chromosomal DNA was 66.0 mol%. The combined genotypic and phenotypic data show that strain P73(T) represents a novel species of the genus Celeribacter, for which the name Celeribacter indicus sp. nov. is proposed. The type strain is P73(T) (?=?MCCC 1A01112(T)?=?LMG 27600(T)?=?DSM 27257(T)). Phylogenetic study and existing phenotypic information also show that Huaishuia halophila should be transferred to the genus Celeribacter as Celeribacter halophilus comb. nov. (type strain ZXM137(T)?=?MCCC 1A06432(T)?=?CGMCC 1.8891(T)?=?LMG 24854(T)). PMID:25256706

  18. Alkalimicrobium pacificum gen. nov., sp. nov., a marine bacterium in the family Rhodobacteraceae.

    PubMed

    Zhang, Gaiyun; Yang, Yanliu; Wang, Shuang; Sun, Zhilei; Jiao, Kailin

    2015-08-01

    A Gram-stain-negative, aerobic, non-motile, rod-shaped bacterium, designated strain F15T, was isolated from a deep-sea sediment of the western Pacific Ocean. The temperature, pH and NaCl ranges for growth were 4-50?°C, pH?6-11 and 0-10?% (w/v), respectively. Strain F15T showed the highest 16S rRNA gene sequence similarity to Sagittula stellata E-37T (96.4%), followed by Ponticoccus litoralis CL-GR66T (96.4%), Antarctobacter heliothermus EL-219T (96.3%) and Thalassococcus lentus YCS-24T (96.0%). Phylogenetic analysis based on 16S rRNA gene sequence data showed that strain F15T formed a lineage within the family Rhodobacteraceae of the class Alphaproteobacteria. The polar lipid profile of strain F15T comprised significant amounts of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified glycolipid and one unidentified phospholipid. The predominant cellular fatty acids were summed feature 8 (C18?:?1?7c and/or C18?:?1?6c, 40.2%), anteiso-C15?:?0 (30.4%) and anteiso-C17?:?0 (9.7%). The genomic DNA G+C content of strain F15T was 60.2?mol% and the major respiratory quinone was Q-10. On the basis of phenotypic, phylogenetic and chemotaxonomic data, strain F15T is considered to represent a novel species of a new genus within the family Rhodobacteraceae, for which the name Alkalimicrobium pacificum gen. nov., sp. nov. is proposed. The type strain is F15T (?=?LMG 28107T?=?JCM 19851T?=?CGMCC 1.12763T?=?MCCC 1A09948T). PMID:25908713

  19. Nesterenkonia alkaliphila sp. nov., an alkaliphilic, halotolerant actinobacteria isolated from the western Pacific Ocean.

    PubMed

    Zhang, Gaiyun; Zhang, Yubian; Yin, Xijie; Wang, Shuang

    2015-02-01

    A Gram-staining-positive, aerobic, motile and non-spore-forming actinobacteria, designated strain F10(T), was isolated from a deep-sea sediment of the western Pacific Ocean. Phylogenetic and phenotypic properties of the organism supported that it belonged to the genus Nesterenkonia. Strain F10(T) shared highest 16S rRNA gene sequence similarity of 96.8 % with Nesterenkonia aethiopica DSM 17733(T), followed by Nesterenkonia xinjiangensis YIM 70097(T) (96.7 %) and Nesterenkonia alba CAAS 252(T) (96.6 %). The organism grew at 4-50 °C, at pH 7.0-12.0 and in the presence of 0-12 % (w/v) NaCl, with optimal growth occurring at 40 °C, at pH 9.0 and in the presence of 1 % (w/v) NaCl. The peptidoglycan type was A4(alpha), l-Lys-Gly-l-Glu. The polar lipid profile of strain F10(T) consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two unknown glycolipids and two unknown lipids. The isolate contained MK-9 (92 %) and MK-8 (5.8 %) as the major components of the menaquinone system, and anteiso-C17 : 0 (50.9 %) and anteiso-C15 : 0 (29.8 %) as the predominant fatty acids. The G+C content of the genomic DNA of strain F10(T) was 66.2 mol%. Based on phenotypic, genotypic and phylogenetic analyses, strain F10(T) represents a novel species of the genus Nesterenkonia for which the name Nesterenkonia alkaliphila sp. nov. is proposed. The type strain is F10(T) (?= LMG 28112(T)?= CGMCC 1.12781(T)?= JCM 19766(T)?= MCCC 1A09946(T)). PMID:25389152

  20. Novosphingobium marinum sp. nov., isolated from seawater.

    PubMed

    Huo, Ying-Yi; You, Hong; Li, Zheng-Yang; Wang, Chun-Sheng; Xu, Xue-Wei

    2015-02-01

    A Gram-stain-negative, aerobic, short rod-shaped bacterium, strain LA53(T), was isolated from a deep-sea water sample collected from the eastern Pacific Ocean. Strain LA53(T) grew in the presence of 0-7.0 % (w/v) NaCl and at 15-37 °C; optimum growth was observed with 1.0-2.0 % (w/v) NaCl and at 35 °C. Chemotaxonomic analysis showed ubiquinone-10 as the predominant respiratory quinone, C18 : 1?7c and summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1?7c) as major fatty acids, and diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and sphingoglycolipid as major polar lipids. The genomic DNA G+C content was 57.7 mol%. Phylogenetic analyses revealed that strain LA53(T) belongs to the genus Novosphingobium. 16S rRNA gene sequence similarities between strain LA53(T) and the type strains of species of the genus Novosphingobium with validly published names ranged from 93.1 to 96.3 %. In addition, strain LA53(T) could be differentiated from Novosphingobium pentaromativorans DSM 17173(T) and Novosphingobium indicum DSM 23608(T) as well as the type strain of the type species of the genus, Novosphingobium capsulatum DSM 30196(T), by some phenotypic characteristics, including hydrolysis of substrates, utilization of carbon sources and susceptibility to antibiotics. On the basis of phenotypic and genotypic data, strain LA53(T) represents a novel species within the genus Novosphingobium, for which the name Novosphingobium marinum sp. nov. is proposed. The type strain is LA53(T) (?= CGMCC 1.12918(T)?= JCM 30307(T)). PMID:25424486

  1. Marinobacter antarcticus sp. nov., a halotolerant bacterium isolated from Antarctic intertidal sandy sediment.

    PubMed

    Liu, Chang; Chen, Chun-Xiao; Zhang, Xi-Ying; Yu, Yong; Liu, Ang; Li, Guo-Wei; Chen, Xiu-Lan; Chen, Bo; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2012-08-01

    A Gram-staining-negative, aerobic, motile, oxidase- and catalase-positive, rod-shaped strain, designated ZS2-30(T), was isolated from Antarctic intertidal sandy sediment. The strain grew at 4-35 °C (optimum, 25 °C) and in 0-25% (w/v) NaCl (optimum, 3.0-4.0%). It could reduce nitrate to nitrite and hydrolyse Tween 80. The predominant cellular fatty acids of strain ZS2-30(T) were summed feature 3 (C(16:1)?7c and/or C(16:1)?6c), C(16:0), C(18:1)?9c, C(16:1)?9c, C(12:0) 3-OH and C(12:0). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an unidentified aminophospholipid. The genomic DNA G+C content of strain ZS2-30(T) was 55.8 mol%. Analyses of 16S rRNA gene sequences revealed that strain ZS2-30(T) was affiliated with the genus Marinobacter. It showed highest 16S rRNA gene sequence similarities to the type strains of three species of the genus Marinobacter, namely Marinobacter maritimus (98.3%), Marinobacter psychrophilus (98.1%) and Marinobacter goseongensis (97.1%), but the DNA-DNA relatedness values between strain ZS2-30(T) and the above three species were all lower than 45%. Moreover, strain ZS2-30(T) could be distinguished from closely related species of the genus Marinobacter by various phenotypic properties. Based on this taxonomic study using a polyphasic approach, strain ZS2-30(T) is considered to represent a novel species in the genus Marinobacter, for which the name Marinobacter antarcticus sp. nov. is proposed. The type strain of Marinobacter antarcticus is ZS2-30(T) (?=?CGMCC 1.10835(T)?=?KCTC 23684(T)). PMID:21984673

  2. Neptunomonas qingdaonensis sp. nov., isolated from intertidal sand.

    PubMed

    Liu, Ang; Zhang, Xi-Ying; Chen, Chun-Xiao; Xie, Bin-Bin; Qin, Qi-Long; Liu, Chang; Li, Guo-Wei; Li, Hai; Xu, Zhong; Chen, Xiu-Lan; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2013-05-01

    A Gram-negative, motile, aerobic, oxidase- and catalase-positive rod, designated P10-2-4(T), was isolated from an intertidal sand sample collected from a coastal area of Qingdao (Yellow Sea), China. The isolate reduced nitrate to nitrite and grew at 4-33 °C and with 0.5-12?% (w/v) NaCl. The predominant cellular fatty acids were summed feature 3 (C16?:?1?7c and/or iso-C15?:?0 2-OH), C18?:?1?7c and C16?:?0. The major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The major respiratory quinone was Q-8. The genomic DNA G+C content was 45.1?%. Phylogenetic analysis of 16S rRNA gene sequences revealed that strain P10-2-4(T) belonged to the genus Neptunomonas. The isolate shared the highest 16S rRNA gene sequence similarity (98.1?%) with Neptunomonas japonica JAMM 0745(T) and 96.9, 96.5 and 95.9?% sequence similarities with N. antarctica S3-22(T), N. concharum LHW37(T) and N. naphthovorans NAG-2N-126(T), respectively, strains of the other three recognized species in the genus. DNA-DNA relatedness between strain P10-2-4(T) and N. japonica JCM 14595(T) was 35.6?%. Furthermore, strain P10-2-4(T) could be distinguished from the representatives of the genus Neptunomonas by a combination of phenotypic characteristics, such as temperature and NaCl concentration for growth, nitrate reduction, DNase activity and assimilation of substrates. The data from this study suggests that strain P10-2-4(T) represents a novel species in the genus Neptunomonas, for which the name Neptunomonas qingdaonensis sp. nov. is proposed. The type strain is P10-2-4(T) (?=?CGMCC 1.10971(T) ?=?KCTC 23686(T)). PMID:22904225

  3. Pseudorhodobacter antarcticus sp. nov., isolated from Antarctic intertidal sandy sediment, and emended description of the genus Pseudorhodobacter Uchino et al. 2002 emend. Jung et al. 2012.

    PubMed

    Chen, Chun-Xiao; Zhang, Xi-Ying; Liu, Chang; Yu, Yong; Liu, Ang; Li, Guo-Wei; Li, Hai; Chen, Xiu-Lan; Chen, Bo; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2013-03-01

    A Gram-negative, aerobic, non-motile, pink-pigmented and rod-shaped strain, designated ZS3-33(T), was isolated from Antarctic intertidal sandy sediment. The strain grew optimally at 15 °C and with 1.0?% (w/v) NaCl. It reduced nitrate to nitrite and hydrolysed Tween 20. It could not produce bacteriochlorophyll a. The predominant cellular fatty acid was C18?:?1?7c and the predominant respiratory quinone was Q-10. The major polar lipids were phosphatidylglycerol, phosphatidylcholine, two unidentified aminophospholipids and an unidentified aminolipid. Analyses of 16S rRNA gene sequences revealed that strain ZS3-33(T) belonged to the genus Pseudorhodobacter, showing 97.4?% similarity to the type strain of Pseudorhodobacter ferrugineus and 95.3?% similarity to the type strain of Pseudorhodobacter aquimaris. Levels of gyrB gene sequence similarity between strain ZS3-33(T) and the type strains of P. ferrugineus and P. aquimaris were 87.6 and 81.7?%, respectively. DNA-DNA relatedness between strain ZS3-33(T) and P. ferrugineus DSM 5888(T) was 56.6?%. The genomic DNA G+C content of strain ZS3-33(T) was 57.1 mol%. Based on data from this polyphasic study, strain ZS3-33(T) represents a novel species of the genus Pseudorhodobacter, for which the name Pseudorhodobacter antarcticus sp. nov. is proposed. The type strain is ZS3-33(T) (?=?CGMCC 1.10836(T)?=?KCTC 23700(T)). An emended description of the genus Pseudorhodobacter Uchino et al. 2002 emend. Jung et al. 2012 is also proposed. PMID:22611201

  4. Escherichia marmotae sp. nov., isolated from faeces of Marmota himalayana.

    PubMed

    Liu, Sha; Jin, Dong; Lan, Ruiting; Wang, Yiting; Meng, Qiong; Dai, Hang; Lu, Shan; Hu, Shoukui; Xu, Jianguo

    2015-07-01

    The taxonomic position of a group of seven closely related lactose-negative enterobacterial strains, which were isolated from fresh faecal samples of Marmota himalayana collected from the Qinghai-Tibetan plateau, China, was determined by using a polyphasic approach. Cells were Gram-reaction-negative, non-sporulating, non-motile, short rods (0.5-1 × 1-2.5 ?m). By 16S rRNA gene sequences, the representative strain, HT073016(T), showed highest similarity values with Escherichia fergusonii ATCC 35469(T) at 99.3%, Escherichia coli ATCC 11775(T) at 99.2%, Escherichia albertii LMG 20976(T) at 98.9%, Escherichia hermannii CIP 103176(T) at 98.4%, and Escherichia vulneris ATCC 33821(T) at 97.7%. Phylogenetic analysis based on the 16S rRNA gene sequences showed that the seven strains formed a monophyletic group with five other species of the genus Escherichia. Digital DNA-DNA hybridization studies between strain HT073016(T) and five other species of the genus Escherichia showed that it shared less than 70% DNA-DNA relatedness with all known species of the genus Escherichia, supporting the novel species status of the strain. The DNA G+C content of strain HT073016(T) was 53.8 mol%. On the basis of phenotypic and phylogenetic characteristics, strain HT073016(T) and the six other HT073016(T)-like strains were clearly distinct from the type strains of other recognized species of the genus Escherichia and represent a novel species of the genus Escherichia, for which the name Escherichia marmotae sp. nov. is proposed, with HT073016(T) (?= CGMCC 1.12862(T) = DSM 28771(T)) as the type strain. PMID:25851592

  5. Bacillus wuyishanensis sp. nov., isolated from rhizosphere soil of a medical plant, Prunella vulgaris.

    PubMed

    Liu, Bo; Liu, Guo-Hong; Sengonca, Cetin; Schumann, Peter; Che, Jian-Mei; Zhu, Yu-Jing; Wang, Jie-Ping

    2015-07-01

    A Gram-staining-positive, rod-shaped, endospore-forming, aerobic bacterium (FJAT-17212(T)) was isolated from the rhizosphere soil of a medical plant, Prunella vulgaris (common selfheal), on the Wuyishan mountain of China. Isolate FJAT-17212(T) grew at 10-50 °C (optimum 30 °C), pH 5-11 (optimum pH 7) and with 0-6% (w/v) NaCl (optimum 2%). Phylogenetic analyses based on 16S rRNA gene sequences showed that isolate FJAT-17212(T) was a member of the genus Bacillus and was most closely related to Bacillus galactosidilyticus DSM 15595(T) (97.3%). DNA-DNA relatedness between isolate FJAT-17212(T) and B. galactosidilyticus DSM 15595(T) was low (35.2% ± 2.3). The diagnostic diamino acid of the peptidoglycan of isolate FJAT-17212(T) was meso-diaminopimelic acid and the predominant isoprenoid quinone was MK-7 (80.8%). The major cellular fatty acids were iso-C15 : 0 (35.7%), anteiso-C15 : 0 (29.8%), iso-C14 : 0 (9.9%) and iso-C16 : 0 (9.9%) and the DNA G+C content was 39.8 mol%. Phenotypic, chemotaxonomic and genotypic properties clearly indicated that isolate FJAT-17212(T) represents a novel species within the genus Bacillus, for which the name Bacillus wuyishanensis sp. nov. is proposed. The type strain is FJAT-17212(T) (?= DSM 27848(T) = CGMCC 1.12709(T)). PMID:25825245

  6. Kangiella profundi sp. nov., isolated from deep-sea sediment.

    PubMed

    Xu, Fang-di; Li, Xue-gong; Xiao, Xiang; Xu, Jun

    2015-07-01

    A taxonomic study employing a polyphasic approach was carried out on strain FT102(T), which was isolated from a deep-sea sediment sample collected in the south-west Indian Ocean at a depth of 2784 m. The strain was Gram-stain-negative, non-motile, rod-shaped and non-spore-forming. It grew optimally at 37-42 °C, pH 6.5-8.5 and in the presence of 1-4% (w/v) NaCl. Phylogenetic analysis of 16S rRNA gene sequences confirmed the separation of the novel strain from recognized members of the genus Kangiella that are available in public databases. Strain FT102(T) exhibited 95.5-98.6% 16S rRNA gene sequence similarity to the type strains of the eight recognized species of the genus Kangiella. The chemotaxonomically characteristic fatty acid iso-C15:0 and ubiquinone Q-8 were also detected. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylmonomethylethanolamine. The DNA G + C content of strain FT102(T) was 45.0 mol%. The mean DNA-DNA relatedness values between strain FT102(T) and the type strains of Kangiella aquimarina and Kangiella koreensis were 47.3% and 13.7%, respectively. The combined results of phylogenetic, physiological and chemotaxonomic studies indicated that strain FT102(T) was affiliated with the genus Kangiella but differed from the recognized species of the genus Kangiella. Therefore, strain FT102T represents a novel species of the genus Kangiella, for which the name Kangiella profundi sp. nov. is proposed. The type strain is FT102(T) (?= CGMCC 1.12959(T) = KCTC 42297(T) = JCM 30232(T)). PMID:25870256

  7. Marivita lacus sp. nov., isolated from a saline lake.

    PubMed

    Zhong, Zhi-Ping; Liu, Ying; Hou, Ting-Ting; Liu, Hong-Can; Zhou, Yu-Guang; Wang, Fang; Liu, Zhi-Pei

    2015-06-01

    A Gram-staining-negative, strictly heterotrophic and aerobic bacterium, strain TS-T44T, was isolated from a saline lake, Tuosu Lake in Qaidam basin, Qinghai province, China. Its taxonomic position was investigated using a polyphasic approach. Cells of strain TS-T44T were non-endospore-forming, non-motile rods, 0.8-1.2 ?m wide and 1.2-3.0 ?m long. Catalase- and oxidase-positive. Growth occurred in the presence of up to 8 % (w/v) NaCl (optimum, 3.0 %) and at 15-35 °C (optimum, 25 °C) and pH 7.0-10.0 (optimum, pH 7.5-8.5). C18 : 1?7c was the predominant fatty acid. The major respiratory quinone was Q-10. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, an unidentified aminolipid and an unknown lipid. The DNA G+C content was 65.5 mol% [determined from the melting temperature (Tm)]. Phylogenetic trees based on 16S rRNA gene sequences showed that strain TS-T44T was associated with the genus Marivita and showed highest sequence similarity to Marivita cryptomonadis CL-SK44T (97.7 %), Marivita litorea CL-JM1T (97.5 %) and Marivita geojedonensis DPG-138T (97.3 %), and < 97 % to other species. DNA-DNA relatedness of strain TS-T44T to M. cryptomonadis JCM 15447T, M. litorea JCM 15446T and M. geojedonensis KCTC 23882T was 23 ± 3 %, 33 ± 4 % and 35 ± 2 %, respectively. Based on the data presented, it is concluded that strain TS-T44T represents a novel species of the genus Marivita, for which the name Marivita lacus sp. nov. is proposed. The type strain is TS-T44T (?= CGMCC 1.12478T =?JCM 19516T). PMID:25792367

  8. Paenibacillus wenxiniae sp. nov., a nifH gene -harbouring endophytic bacterium isolated from maize.

    PubMed

    Gao, Jun-Lian; Lv, Fan-Yang; Wang, Xu-Ming; Qiu, Tian-Lei; Yuan, Mei; Li, Ji-Wei; Zhou, Yi; Sun, Jian-Guang

    2015-11-01

    A novel Gram-positive, aerobic, motile, endospore-forming, rod-shaped bacterium, designated 373(T) was isolated from surface-sterilised root tissue of a maize planted in Fangshan District of Beijing, Peopole's Republic of China. A polyphasic taxonomic study was performed on the new isolate. On the basis of 16S rRNA gene sequence similarity studies, this isolate belongs to the genus Paenibacillus. The highest 16S rRNA gene sequence similarity was found between strain 373(T) and Paenibacillus hunanensis (98.1 %), meanwhile the 16S rRNA gene sequence similarity between strain 373(T) and the type strains of other recognised members of the genus Paenibacillus were all below 95.6 %. However, the DNA-DNA hybridization values between strain 373(T) and the type strain P. hunanensis DSM 22170(T) was 30.2 %. The DNA G+C content of strain 373(T) was determined to be 46.0 mol%. The predominant respiratory quinone was identified as menaquinone-7 and the polar lipid profile was found to be composed of the major lipids diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids were found to consist of anteiso-C15: 0 (59.6 %), anteiso-C17: 0 (12.8 %) and C16: 0 (6.7 %). The results of physiological and biochemical tests and minor differences in the fatty acid profiles allowed a clear phenotypic differentiation of strain 373(T) from the closely related species in this genus Paenibacillus. Strain 373(T) is concluded to represent a novel species within the genus Paenibacillus, for which the name Paenibacillus wenxiniae sp. nov. is proposed, with the type strain 373(T) (= CGMCC 1.15007 (T) = DSM100576 ). PMID:26346477

  9. Actinomycetospora rhizophila sp. nov., an actinomycete isolated from rhizosphere soil of a peace lily (Spathi phyllum Kochii).

    PubMed

    He, Hairong; Zhang, Yuejing; Ma, Zhaoxu; Li, Chuang; Liu, Chongxi; Zhou, Ying; Li, Lianjie; Wang, Xiangjing; Xiang, Wensheng

    2015-05-01

    A novel actinomycete, designated strain NEAU-B-8(T), was isolated from the rhizosphere soil of a peace lily (Spathi phyllum Kochii) collected from Heilongjiang province, north-east China. Key morphological and physiological characteristics as well as chemotaxonomic features of strain NEAU-B-8(T) were congruent with the description of the genus Actinomycetospora , such as the major fatty acids, the whole-cell hydrolysates, the predominant menaquinone and the phospholipid profile. The 16S rRNA gene sequence analysis revealed that strain NEAU-B-8(T) shared the highest sequence similarities with Actinomycetospora lutea JCM 17982(T) (99.3% 16S rRNA gene sequence similarity), Actinomycetospora chlora TT07I-57(T) (98.4?%), Actinomycetospora straminea IY07-55(T) (98.3%) and Actinomycetospora chibensis TT04-21(T) (98.2%); similarities to type strains of other species of this genus were lower than 98%. The phylogenetic tree based on 16S rRNA gene sequences showed that strain NEAU-B-8(T) formed a distinct branch with A. lutea JCM 17982(T) that was supported by a high bootstrap value of 97% in the neighbour-joining tree and was also recovered with the maximum-likelihood algorithm. However, the DNA-DNA relatedness between strain NEAU-B-8(T) and A. lutea JCM 17982(T) was found to be 50.6 ± 1.2%. Meanwhile, strain NEAU-B-8(T) differs from other most closely related strains in phenotypic properties, such as maximum NaCl tolerance, hydrolysis of aesculin and decomposition of urea. On the basis of the morphological, physiological, chemotaxonomic, phylogenetic and DNA-DNA hybridization data, we conclude that strain NEAU-B-8(T) represents a novel species of the genus Actinomycetospora , named Actinomycetospora rhizophila sp. nov. The type strain is NEAU-B-8(T). (?= CGMCC 4.7134(T)?=DSM 46673(T)). PMID:25701847

  10. Salinicola peritrichatus sp. nov., isolated from deep-sea sediment.

    PubMed

    Huo, Ying-Yi; Meng, Fan-Xu; Xu, Lin; Wang, Chun-Sheng; Xu, Xue-Wei

    2013-07-01

    A Gram stain-negative, aerobic and rod-shaped bacterium, strain DY22(T), was isolated from a deep-sea sediment collected from the east Pacific Ocean. The isolate was found to grow in the presence of 0-20.0 % (w/v) NaCl and at pH 4.5-8.5; optimum growth was observed with 0.5-2.0 % (w/v) NaCl and at pH 5.0-7.0. Chemotaxonomic analysis showed the presence of ubiquinone-9 as predominant respiratory quinone and C16:0, C19:0 ?8c cyclo and C12:0 3-OH as major cellular fatty acids. The genomic DNA G+C content was determined to be 59.6 mol%. Comparative 16S rRNA gene sequence analysis revealed that the novel isolate belongs to the genus Salinicola. Strain DY22(T) exhibited the closest phylogenetic affinity to the type strain of Salinicola salarius with 97.2 % sequence similarity and less than 97 % sequence similarity with respect to other Salinicola species with validly published names. The DNA-DNA reassociation values between strain DY22(T) and S. salarius DSM 18044(T) was 52 ± 4 %. On the basis of phenotypic, chemotaxonomic and genotypic data, strain DY22(T) represents a novel species of the genus Salinicola, for which the name Salinicola peritrichatus sp. nov. (type strain DY22(T) = CGMCC 1.12381(T) = JCM 18795(T)) is proposed. PMID:23609050

  11. Flavobacterium caeni sp. nov., isolated from a sequencing batch reactor for the treatment of malachite green effluents.

    PubMed

    Liu, Ying; Jin, Jing-Hua; Zhou, Yu-Guang; Liu, Hong-Can; Liu, Zhi-Pei

    2010-02-01

    A Gram-stain-negative, heterotrophic, aerobic, non-spore-forming and non-motile bacterial strain, designated LM5(T), was isolated from activated sludge from a sequencing batch reactor for the treatment of effluents contaminated by malachite green. The taxonomy of strain LM5(T) was studied by phenotypic and phylogenetic methods. Strain LM5(T) formed orange colonies on R2A and YP plates. Cells were rods, 0.4-0.6 microm in diameter and 0.8-1.2 microm in length. Growth occurred at 10-35 degrees C (optimum, 20-25 degrees C), at pH 5.5-9.5 (optimum, pH 6.5-7.5) and in the presence of 0-2 % (w/v) NaCl (optimum, 0.5 %). Oxidase and catalase activities were present. Flexirubin-type pigments were present, but extracellular glycans were absent. MK-6 was the major respiratory quinone. The major fatty acids were iso-C(15 : 0) (28.3 %) and iso-C(17 : 1)omega9c (13.8 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain LM5(T) was a member of the genus Flavobacterium with highest sequence similarity to Flavobacterium soli DS-6(T) (93.2 %) and Flavobacterium lindanitolerans IP-10(T) (92.9 %). Together with F. lindanitolerans IP-10(T), strain LM5(T) formed a distinct lineage in the phylogenetic tree. The DNA G+C content was 52+/-0.6 mol% (HPLC), which is significantly higher than that of other species of the genus Flavobacterium (30-41 mol%). Based on phylogenetic and phenotypic evidence, strain LM5(T) is considered to represent a novel species of the genus Flavobacterium, for which the name Flavobacterium caeni sp. nov. is proposed; the type strain is LM5(T) (=CGMCC 1.7031(T)=NBRC 104239(T)). PMID:19651715

  12. Halomonas korlensis sp. nov., a moderately halophilic, denitrifying bacterium isolated from saline and alkaline soil.

    PubMed

    Li, Hong-Bin; Zhang, Lei-Ping; Chen, San-Feng

    2008-11-01

    Five Gram-negative, rod-shaped, moderately halophilic and denitrifying strains, designated XK1(T), XK2, XK3, XK4 and XK5, were isolated from a saline and alkaline soil in Korla, north-western China. These isolates could grow anaerobically using either nitrate or nitrite as terminal electron acceptors and produced gas from nitrate vigorously. A comparison and phylogenetic analysis of 16S rRNA gene sequences placed these isolates in the genus Halomonas within the family Halomonadaceae. The isolates shared the highest 16S rRNA gene sequence similarities with Halomonas ventosae Al12(T )(95.6 %), Halomonas alimentaria YKJ-16(T) (95.5 %) and Halomonas shengliensis SL014B-85(T) (95.2 %) (values determined by mega 3.1; direct comparison results with GenBank were even lower, not >/=94 %). Sequence similarities with other recognized species were below 95.0 %, far below the 97.0 % threshold generally accepted for the delineation of separate species. BOX-PCR fingerprinting and DNA-DNA hybridization showed high similarities among the five strains which indicated they were members of the same species. The major fatty acids were C(18 : 1)omega8t, C(16 : 0) and C(18 : 1)omega7t. The DNA G+C content was 65.3 mol%. All the results of the phenotypic and genetic analyses supported the hypothesis that the five new strains represent a novel species within the genus Halomonas, for which the name Halomonas korlensis sp. nov. is proposed. The type strain is XK1(T) (=CGMCC 1.6981(T)=DSM 19633(T)). PMID:18984697

  13. Kocuria subflava sp. nov., isolated from marine sediment from the Indian Ocean.

    PubMed

    Jiang, Zhao; Zhang, Wei-Hua; Yuan, Chang-Guo; Chen, Jia-Yang; Cao, Li-Xiang; Park, Dong-Jin; Xiao, Min; Kim, Chang-Jin; Li, Wen-Jun

    2015-12-01

    A novel Gram-staining positive, catalase-positive, oxidase-negative, aerobic, non-motile coccus, designated strain YIM 13062(T), was isolated from a marine sediment sample collected from the Indian Ocean. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 13062(T) belongs to the genus Kocuria, and is closely related to Kocuria polaris NBRC 103063(T) (97.8 % similarity), Kocuria rosea NBRC 3768(T) (97.6 % similarity) and Kocuria carniphila JCM 14118(T) (97.4 % similarity). The strain grew optimally at 28 °C, pH 8.0 and in the presence of 2-4 % (w/v) NaCl. Cell-wall peptidoglycan type was Lys-Ala3 (type A3?). The major isoprenoid quinones were MK-6(H2) and MK-7(H2). The polar lipids of strain YIM 13062(T) consisted of diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), one unidentified phospholipid (PL), one unidentified aminophospholipid (APL), two unidentified aminolipids (AL) and four unidentified lipids (L). Major fatty acids of the novel isolate were anteiso-C15:0, iso-C14:0 and C18:1 2OH. The genomic DNA G+C content of strain YIM 13062(T) was 68.0 mol%. The level of DNA-DNA relatedness between strain YIM 13062(T) and K. polaris NBRC 103063(T), K. rosea NBRC 3768(T), K. carniphila JCM 14118(T) were 53.2, 48.8 and 42.6 %, respectively. On the basis of genotypic and phenotypic data, it is apparent that strain YIM 13062(T) represents a novel species of the genus Kocuria, for which the name Kocuria subflava sp. nov. is proposed. The type strain is YIM 13062(T) (=CGMCC 4.7252(T)=KCTC 39547(T)). PMID:26362332

  14. Nocardia rhizosphaerae sp. nov., a novel actinomycete isolated from the coastal rhizosphere of Artemisia Linn., China.

    PubMed

    Wang, Yu; Liu, Wei; Feng, Wei-Wei; Zhou, Xiao-Qi; Bai, Juan-Luan; Yuan, Bo; Ju, Xiu-Yun; Cao, Cheng-Liang; Huang, Ying; Jiang, Ji-Hong; Lv, Ai-Jun; Qin, Sheng

    2015-07-01

    A novel actinomycete, designated strain KLBMP S0043(T), was isolated from the rhizosphere soil of Artemisia Linn. collected from the coastal region of Lianyungang, Jiangsu Province, in east China and was studied in detail for its taxonomic position. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain KLBMP S0043(T) is a member of the genus Nocardia. The 16S rRNA gene sequence similarity indicated that strain KLBMP S0043(T) is closely related to Nocardia asteroides NBRC 15531(T) (97.61 %) and Nocardia neocaledoniensis SBHR OA6(T) (97.38 %); similarity to other type strains of the genus Nocardia was found to be less than 97.2 %. The organism has chemical and morphological features consistent with its classification in the genus Nocardia such as meso-diaminopimelic acid as the diagnostic diamino acid in the cell wall peptidoglycan and arabinose and galactose as the diagnostic sugars. The predominant menaquinone was identified as MK-8(H4?-cycl). Mycolic acids were detected. The diagnostic phospholipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. The predominant cellular fatty acids were identified as C16:0, C18:0, C18:1?9c, 10-methyl C18:0 [tuberculostearic acid (TBSA)] and summed feature 3 (C16:1?7c/C16:1?6c). The G+C content of the genomic DNA was determined to be 71.4 mol%. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of the strain from its most closely related strains. Based on morphological, chemotaxonomic and phylogenetic data, strain KLBMP S0043(T) is considered to represent a novel species of the genus Nocardia, for which the name Nocardia rhizosphaerae sp. nov. is proposed. The type strain is KLBMP S0043(T) (=CGMCC 4.7204 (T) = KCTC 29678(T)). PMID:25896308

  15. Gemmobacter megaterium sp. nov., isolated from coastal planktonic seaweeds.

    PubMed

    Liu, Jin-Jin; Zhang, Xin-Qi; Chi, Fang-Tao; Pan, Jie; Sun, Cong; Wu, Min

    2014-01-01

    A Gram-stain-negative, non-motile and aerobic bacterium, designated CF17(T), was isolated from coastal planktonic seaweeds, East China Sea. The isolate grew at 18-37 °C (optimum 25-28 °C), pH 6.5-9.0 (optimum 7.0-8.0) and with 0-5?% NaCl (optimum 1-2?%, w/v) and 0.5-10?% sea salts (optimum 2-3?%, w/v). Growth of strain CF17(T) could be stimulated prominently by supplementing the growth medium with the autoclaved supernatant of a culture of strain CF5, which was isolated from the same sample along with strain CF17(T). The cell morphology of strain CF17(T) was a bean-shaped rod consisting of a swollen end and a long prostheca. The phylogenetic analysis of 16S rRNA gene sequences indicated that strain CF17(T) clustered with Gemmobacter nectariphilus DSM 15620(T) within the genus Gemmobacter. The DNA G+C content of strain CF17(T) was 61.4 mol%. The respiratory quinone was ubiquinone Q-10. The major fatty acids included C18?:?1?7c and C18?:?0. The polar lipids of strain CF17(T) consisted of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, two uncharacterized phospholipids, one uncharacterized aminolipid, three uncharacterized glycolipids and one uncharacterized lipid. On the basis of phenotypic, phylogenetic and chemotaxonomic data, strain CF17(T) (?=?CGMCC 1.11024(T)?=?JCM 18498(T)) is considered to represent a novel species of the genus Gemmobacter, for which the name Gemmobacter megaterium sp. nov. is proposed. PMID:24014623

  16. Pedobacter xixiisoli sp. nov., isolated from bank soil.

    PubMed

    Zeng, Yanhua; Feng, Hao; Huang, Yili

    2014-11-01

    A Gram-stain-negative, rod-shaped, yellow, non-motile, aerobic bacterium (strain S27(T)) was isolated from bank soil of the Xixi wetland in Zhejiang province, PR China. Phylogenetic analysis, based on its 16S rRNA gene sequence, revealed that strain S27(T) could represent a novel species of the genus Pedobacter showing highest similarity to Pedobacter koreensis WPCB189(T) (95.45%), followed by 'Pedobacter zeaxanthinifaciens' TDMA-5 (95.22%). The temperature, pH and NaCl concentration ranges for growth were 6-37 °C (optimum 28 °C), pH 5.0-9.0 (optimum pH 7.5) and 0-3% (w/v) [optimum 0.5% (w/v)], respectively. The DNA G+C content was 36.1 mol%, MK-7 was the only respiratory quinone, and iso-C(15:0), iso-C(17:0) 3-OH and summed feature 3 (C(16:1)?7c and/or iso-C(15:0) 2-OH) were the major fatty acids. These data all support the affiliation of strain S27(T) to the genus Pedobacter. The polar lipids of strain S27(T) comprised phosphatidylethanolamine, one unidentified aminophospholipid, four unidentified aminolipids and three unidentified lipids. However, strain S27(T) could be distinguished from other members of the genus Pedobacter due to its physiological and biochemical characteristics. Therefore, strain S27(T) represents a novel species of the genus Pedobacter, for which the name Pedobacter xixiisoli sp. nov. is proposed; the type strain is S27(T) (?=CGMCC 1.12803(T)?=NBRC 110388(T)). PMID:25106922

  17. Chryseobacterium takakiae sp. nov., a member of the phylum Bacteroidetes isolated from Takakia lepidozioides.

    PubMed

    Zhao, Ran; Chen, Xin Yao; Li, Xue Dong; Chen, Zhi Ling; Li, Yan Hong

    2015-01-01

    A Gram-stain-negative, rod-shaped and non-endospore-forming bacterium, designated strain AG1-2(T), was isolated from Takakia lepidozioides collected from the Gawalong glacier in Tibet, China and characterized using a polyphasic taxonomic approach. The predominant fatty acids of strain AG1-2(T) were iso-C15?:?0 (36.0?%), iso-C17:0 3-OH (20.2?%), summed feature 9 (iso-C17:1?9c and/or C16:0 10-methyl, 16.4%) and summed feature 3 (C16:1?7c and/or C16:1?6c, 11.1%). The major polar lipids were phosphatidylethanolamine, three unidentified aminolipids and two unidentified lipids. Strain AG1-2(T) contained MK-6 as the dominant menaquinone, and the genomic DNA G+C content was 37.3 mol%. The phylogenetic analysis based on the 16S rRNA gene sequences showed that strain AG1-2(T) was affiliated to species of the genus Chryseobacterium, and its closest related species were Chryseobacterium taiwanense Soil-3-27(T), Chryseobacterium hispalense AG13(T), Chryseobacterium camelliae THG C4-1(T) and Chryseobacterium taeanense PHA3-4(T) with a sequence similarity of 98.0, 97.8, 97.3 and 97.1%, respectively. However, the DNA-DNA relatedness values between these strains and strain AG1-2(T) were 29, 21, 21 and 45%, respectively. Based on phylogenetic inference and phenotypic data, strain AG1-2(T) is considered to represent a novel species of the genus Chryseobacterium, for which the name Chryseobacterium takakiae sp. nov. is proposed. The type strain is AG1-2(T) (?=?CGMCC 1.12488(T)?=?DSM 26898(T)). PMID:25273512

  18. Pseudonocardia nematodicida sp. nov., isolated from mangrove sediment in Hainan, China.

    PubMed

    Liu, Min; Xing, Shan-shan; Yuan, Wei-dao; Wei, Hua; Sun, Qian-guang; Lin, Xiang-zhi; Huang, Hui-qin; Bao, Shi-xiang

    2015-09-01

    Two aerobic, Gram-stain positive actinobacterial strains with nematicidal activity, designated HA11164(T) and HA12591, were isolated from mangrove sediments in Hainan, China. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strains HA11164(T) and HA12591 belong to the genus Pseudonocardia and are closely related to Pseudonocardia carboxydivorans (with the similarities of 98.30 and 98.24 %, respectively), Pseudonocardia alni (98.23 and 98.16 %, respectively) and Pseudonocardia antimicrobica (98.10 and 98.03 %, respectively). The major polar lipids of the strain HA11164(T), as a representative strain of the two strains, were found to consist of phosphatidylmethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, five unidentified glycolipids and four unidentified polar lipids. The predominant menaquinone of strain HA11164(T) was identified as MK-8 (H4), and the major fatty acids were identified as iso-C16:0, C17:1 ?10, C16:0 and C16:1 ?9. The G+C content of strain HA11164(T) was determined to be 74.9 mol%. The DNA-DNA relatedness values between strains HA11164(T) and P. alni, Pseudonocardia tropica, Pseudonocardia antarctica, P. carboxydivorans and Pseudonocardia parietis were 58.3, 56.2, 50.0, 57.1 and 46.0 %, respectively. Based on the results of this polyphasic study, strains HA11164(T) and HA12591 are considered to represent a novel species of the genus Pseudonocardia, for which the name Pseudonocardia nematodicida sp. nov. is proposed. The type strain is HA11164(T) (=CGMCC 4.7118(T) = DSM 45940(T)). PMID:26115882

  19. Streptomyces aidingensis sp. nov., an actinomycete isolated from lake sediment.

    PubMed

    Xia, Zhan-Feng; Ruan, Ji-Sheng; Huang, Ying; Zhang, Li-Li

    2013-09-01

    A novel actinomycete strain, designated TRM 46012(T), was isolated from sediment of Aiding Lake in Tulufan Basin (42° 64' N 89° 26' E), north-west China. The strain was aerobic and Gram-staining-positive with an optimum NaCl concentration for growth of 0-5% (w/v). The isolate had sparse aerial mycelium and produced bud-shaped spores at the end of the aerial mycelium on ISP medium 4. The isolate contained ll-diaminopimelic acid as the diagnostic diamino acid and ribose as the major whole-cell sugar. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, phosphatidylinositol mannoside, one unidentified phospholipid and three unidentified glycolipids. The predominant menaquinones were MK-9(H?), MK-9(H?) and MK-9(H?). The major fatty acids were iso-C(16:0), anteiso-C(17:0) and anteiso-C(15:0). The G+C content of the DNA was 74.4 mol%. Phylogenetic analysis showed that strain TRM 46012(T) had 16S rRNA gene sequence similarity of 95.7% with the most closely related species with a validly published name, Streptomyces cheonanensis, and it could be distinguished from all species in the genus Streptomyces by using the data from this polyphasic taxonomic study. On the basis of these data, strain TRM 46012(T) should be designated as a representative of a novel species of the genus Streptomyces, for which the name Streptomyces aidingensis sp. nov. is proposed. The type strain is TRM 46012(T) (?=CGMCC 4.5739(T)?=NBRC 108211(T)). PMID:23456804

  20. Rhodococcus kronopolitis sp. nov., a novel actinobacterium isolated from a millipede (Kronopolites svenhedind Verhoeff).

    PubMed

    Liu, Hui; Zhang, Yuejing; Liu, Chongxi; Fang, Baozhu; Li, Chuang; Guan, Xuejiao; Li, Lianjie; Wang, Xiangjing; Xiang, Wensheng

    2014-12-01

    A novel actinobacterium, designated strain NEAU-ML12(T), was isolated from a millipede (Kronopolites svenhedind Verhoeff), which was collected from Fenghuang Mountain in Wuchang, Heilongjiang Province, north China. The strain was characterized using a polyphasic approach. Strain NEAU-ML12(T) was found to have morphological and chemotaxonomic characteristics typical of the members of the genus Rhodococcus. 16S rRNA gene sequence similarity analysis showed that the strain NEAU-ML12(T) belongs to the genus Rhodococcus, and was most closely related to Rhodococcus tukisamuensis Mb8(T) (98.9 %) and Rhodococcus koreensis DNP505(T) (97.7 %). Phylogenetic analysis based on 16S rRNA gene sequences also demonstrated that strain NEAU-ML12(T) should be classified in the genus Rhodococcus, forming a distinct clade with R. tukisamuensis Mb8(T) supported by a 99 % bootstrap value. However, the DNA-DNA relatedness between strain NEAU-ML12(T) and R. tukisamuensis Mb8(T) was found to be 41.9 ± 0.7 %. Furthermore, strain NEAU-ML12(T) could also be differentiated from R. tukisamuensis Mb8(T) and other closely related strains (R. koreensis DNP505(T) and Rhodococcus maanshanensis M712(T)) by morphological and physiological characteristics. Therefore, it is proposed that strain NEAU-ML12(T) represents a novel species of the genus Rhodococcus, for which the name Rhodococcus kronopolitis sp. nov. is proposed. The type strain is NEAU-ML12(T) (=CGMCC 4.7145(T) = DSM 46702(T)). PMID:25261081

  1. Chryseobacterium polytrichastri sp. nov., isolated from a moss (Polytrichastrum formosum), and emended description of the genus Chryseobacterium.

    PubMed

    Chen, Xin Yao; Zhao, Ran; Chen, Zhi Ling; Liu, Lei; Li, Xue Dong; Li, Yan Hong

    2015-02-01

    A Gram-stain negative, rod-shaped and non-endospore forming bacterium, designated strain YG4-6(T), was isolated from Polytrichastrum formosum collected from Gawalong glacier in Tibet, China and characterized by using a polyphasic taxonomic approach. The predominant fatty acids of strain YG4-6(T) were identified as iso-C15:0 (29.3 %), summed feature 3 (C16:1 ?7c and/or C16:1 ?6c as defined by MIDI, 23.5 %) and iso-C17:0 3-OH (16.5 %). The major polar lipids were found to consist of five unidentified aminolipids and three unidentified lipids. Strain YG4-6(T) was found to contain MK-6 as the dominant menaquinone and the G+C content of its genomic DNA was determined to be 37.3 mol%. The phylogenetic analysis based on 16S rRNA gene sequences showed that strain YG4-6(T) is affiliated to Chryseobacterium species, and its closest related species were Chryseobacterium aahli T68(T) (97.9 % sequence similarity), Chryseobacterium zeae JM-1085(T) (97.8 % sequence similarity), Chryseobacterium yeoncheonense DCY67(T) (97.6 % sequence similarity) and Chryseobacterium soldanellicola NBRC 100864(T) (97.2 % sequence similarity). However, the DNA-DNA relatedness values between these strains and strain YG4-6(T) were found to be clearly below 70 %. Based on the phylogenetic inference and phenotypic data, strain YG4-6(T) is considered to represent a novel species of the genus Chryseobacterium, for which the name Chryseobacterium polytrichastri sp. nov. is proposed. The type strain is YG4-6(T) (=CGMCC 1.12491(T) = DSM 26899(T)). An emended description of the genus Chryseobacterium is also proposed. PMID:25450189

  2. Nocardioides deserti sp. nov., an actinobacterium isolated from desert soil.

    PubMed

    Tuo, Li; Dong, Yan-Ping; Habden, Xugela; Liu, Jia-Meng; Guo, Lin; Liu, Xian-Fu; Chen, Li; Jiang, Zhong-Ke; Liu, Shao-Wei; Zhang, Yu-Bin; Zhang, Yu-Qin; Sun, Cheng-Hang

    2015-05-01

    A rod- or coccus-shaped, non-spore-forming actinobacterium, designated strain SC8A-24(T), was isolated from a soil sample collected from the rhizosphere of Alhagi sparsifolia on the southern edge of the Taklimakan desert, Xinjiang, China, and examined by a polyphasic approach to clarify its taxonomic position. This actinobacterium was Gram-staining-positive and aerobic. Substrate and aerial mycelia were not observed, and no diffusible pigments were observed on the media tested. Strain SC8A-24(T) grew optimally without NaCl at 28-30 °C and pH 7.0-8.0. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain SC8A-24(T) belonged to the genus Nocardioides and shared the highest 16S rRNA gene sequence similarity with Nocardioides salarius CL-Z59(T) (96.51%), N. pyridinolyticus OS4(T) (96.43%) and N. ginsengagri BX5-10(T) (96.37%). The DNA G+C content of strain SC8A-24(T) was 71 mol%. The cell-wall peptidoglycan contained ll-2,6-diaminopimelic acid, and MK-8(H4) was the predominant menaquinone. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, an unidentified glycolipid and an unidentified phospholipid. The major fatty acids were C17 : 1?8c, 10-methyl C17 : 0 and C18 : 1?9c. On the basis of phylogenetic analysis and phenotypic and chemotaxonomic characteristics, strain SC8A-24(T) represents a novel species of the genus Nocardioides , for which the name Nocardioides deserti sp. nov. is proposed. The type strain is SC8A-24(T) (?=DSM 26045(T) ?= CGMCC 4.7183(T)). PMID:25716951

  3. Muriicola marianensis sp. nov., isolated from seawater.

    PubMed

    Hu, Jing; Zhang, Wei-Yan; Zhang, Xin-Qi; Hong-Cheng; Zhu, Xu-Fen; Wu, Min

    2015-02-01

    A Gram-stain-negative, aerobic, orange-pigmented, rod-shaped and non-motile bacterium, designated strain A6B8(T), was isolated from seawater of the Mariana Trench. The isolate grew at 4-50 °C (optimum 30-35 °C), at pH 6.5-8.0 (optimum pH 7.5) and with 0.5-4.0 % (w/v) NaCl (optimum 1.0-2.0 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain A6B8(T) was related most closely to the genus Muriicola and shared highest sequence similarity of 97.7 % with Muriicola jejuensis EM44(T). Chemotaxonomic analysis showed menaquinone 6 (MK-6) was the predominant isoprenoid and iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH were the major cellular fatty acids. The polar lipid profile of strain A6B8(T) included phosphatidylethanolamine, three unidentified aminolipids and four unidentified lipids. The genomic DNA G+C content was 47.1 mol%. The DNA-DNA relatedness value (23.3 %) clearly demonstrated that strains A6B8(T) and M. jejuensis EM44(T) were representatives of two different species. Based on the phenotypic, phylogenetic and chemotaxonomic characterizations, A6B8(T) (?= CGMCC 1.12606(T)?= KCTC 32436(T)) is considered to be the type strain of a novel species of the genus Muriicola, for which the name Muriicola marianensis sp. nov. is proposed. PMID:25376851

  4. Description of a Gram-negative bacterium, Sphingomonas guangdongensis sp. nov.

    PubMed

    Feng, Guang-Da; Yang, Song-Zhen; Wang, Yong-Hong; Zhang, Xiu-Xiu; Zhao, Guo-Zhen; Deng, Ming-Rong; Zhu, Hong-Hui

    2014-05-01

    A Gram-stain-negative bacterial strain, designated 9NM-8T, was isolated from an abandoned lead-zinc ore in Mei county, Meizhou, Guangdong province, PR China. The isolate was orange-pigmented, aerobic, oxidase- and catalase-positive, motile with lophotrichous flagella and rod-shaped. Strain 9NM-8T grew optimally at pH 7.0 and 30 °C and in the absence of NaCl on R2A agar. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 9NM-8T belongs to the genus Sphingomonas, with highest sequence similarities to Sphingomonas azotifigens KACC 14484T (96.1%), Sphingomonas trueperi DSM 7225T (96.0%) and Sphingomonas pituitosa DSM 13101T (95.6?%). Strain 9NM-8T contained Q-10 as the predominant ubiquinone. The major fatty acids included C18:1?7c, C16:0, C16:1?7c and/or C16?:?1?6c (summed feature 3) and 11-methyl C18:1?7c. The DNA G+C content was 69.6±1.3 mol%. The major component in the polyamine pattern was sym-homospermidine and the polar lipid profile contained sphingoglycolipid, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, an unidentified glycolipid and two unidentified phospholipids. Based on comparative analysis of physiological, chemotaxonomic and phylogenetic characteristics, strain 9NM-8T should be considered to represent a novel species of the genus Sphingomonas, for which the name Sphingomonas guangdongensis sp. nov. is proposed. The type strain is 9NM-8T (=GIMCC 1.653T=CGMCC 1.12672T=DSM 27570T). PMID:24523446

  5. Sphaerisporangium dianthi sp. nov., an endophytic actinomycete isolated from a root of Dianthus chinensis L.

    PubMed

    Xing, Jia; Liu, Chongxi; Zhang, Yuejing; He, Hairong; Zhou, Ying; Li, Lianjie; Zhao, Junwei; Liu, Shuanghe; Wang, Xiangjing; Xiang, Wensheng

    2015-01-01

    A novel actinomycete, designated strain NEAU-CY18(T), was isolated from the root of a Chinese medicinal plant Dianthus chinensis L and subjected to a polyphasic taxonomic study. The novel strain was found to develop spherical sporangia with non-motile spores on aerial mycelium. The cell-wall peptidoglycan was found to contain meso-diaminopimelic acid. The whole-cell sugars were identified as madurose, mannose, ribose, galactose and glucose. The phospholipid profile was found to contain diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, hydroxy-phosphatidylmethylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides and an unidentified phospholipid. The predominant menaquinones were identified as MK-9(H4), MK-9(H2) and MK-9(H6). The major fatty acids were identified as C17:0 10-methyl, iso-C16:0 and C16:0. EzTaxon-e analysis of the 16S rRNA gene sequence indicated that the strain belongs to the genus Sphaerisporangium and was most closely related to Sphaerisporangium cinnabarinum JCM 3291(T) (98.9 %) and Sphaerisporangium melleum JCM 13064(T) (98.3 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-CY18(T) forms a monophyletic clade with S. cinnabarinum JCM 3291(T), an association that was supported by a bootstrap value of 97 % in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. Comparisons of some phenotypic properties and low DNA-DNA relatedness values enabled the strain to be differentiated from S. cinnabarinum JCM 3291(T) and S. melleum JCM 13064(T). Therefore, it is concluded that strain NEAU-CY18(T) represents a novel Sphaerisporangium species, for which the name Sphaerisporangium dianthi sp. nov. is proposed. The type strain is NEAU-CY18(T) ( = CGMCC 4.7132(T) = DSM 46736(T)). PMID:25294725

  6. Bulk Segregant Analysis Reveals the Genetic Basis of a Natural Trait Variation in Fission Yeast

    PubMed Central

    Hu, Wen; Suo, Fang; Du, Li-Lin

    2015-01-01

    Although the fission yeast Schizosaccharomyces pombe is a well-established model organism, studies of natural trait variations in this species remain limited. To assess the feasibility of segregant-pool-based mapping of phenotype-causing genes in natural strains of fission yeast, we investigated the cause of a maltose utilization defect (Mal-) of the S. pombe strain CBS5557 (originally known as Schizosaccharomyces malidevorans). Analyzing the genome sequence of CBS5557 revealed 955 nonconservative missense substitutions, and 61 potential loss-of-function variants including 47 frameshift indels, 13 early stop codons, and 1 splice site mutation. As a side benefit, our analysis confirmed 146 sequence errors in the reference genome and improved annotations of 27 genes. We applied bulk segregant analysis to map the causal locus of the Mal- phenotype. Through sequencing the segregant pools derived from a cross between CBS5557 and the laboratory strain, we located the locus to within a 2.23-Mb chromosome I inversion found in most S. pombe isolates including CBS5557. To map genes within the inversion region that occupies 18% of the genome, we created a laboratory strain containing the same inversion. Analyzing segregants from a cross between CBS5557 and the inversion-containing laboratory strain narrowed down the locus to a 200-kb interval and led us to identify agl1, which suffers a 5-bp deletion in CBS5557, as the causal gene. Interestingly, loss of agl1 through a 34-kb deletion underlies the Mal- phenotype of another S. pombe strain CGMCC2.1628. This work adapts and validates the bulk segregant analysis method for uncovering trait-gene relationship in natural fission yeast strains. PMID:26615217

  7. Flavobacterium buctense sp. nov., isolated from freshwater.

    PubMed

    Feng, Xiao-Min; Tan, Xu; Jia, Li; Long, Ping-Ping; Han, Lu; Lv, Jie

    2015-11-01

    A gram-negative, non-gliding motile, aerobic bacterium, designated as strain T7(T), was isolated from freshwater of Chishui River flowing through Maotai town, Guizhou Province, southwest of China. Based on the 16S rRNA gene sequence analysis, the isolate was identified as a member of the genus Flavobacterium and that shared less than 97 % sequence similarities with recognized Flavobacterium species. Its closest phylogenetic relative was Flavobacterium dankookense (96.9 %), followed by Flavobacterium cheonhonense (96.8 %) and Flavobacterium macrobrachii (96.7 %). The strain formed smooth yellow colonies on R2A plates, and cells were observed to be short rods. Strain T7(T) was found to be able to grow at 15-30 °C (optimum 25 °C), at NaCl concentration of 0-0.5 % (optimum 0 %) and at pH 6.5-9.5 (optimum pH 7.5). Catalase and oxidase tests were positive. Polar lipids of strain T7(T) included phosphatidylethanolamine, four unidentified polar lipids, one unidentified phospholipid and one unidentified aminolipid. Chemotaxonomic analysis revealed menaquinone-6 as the dominant respiratory quinone and C15:0, iso-C15:0 and iso-C15:1 as the major fatty acids. The DNA G+C content of strain T7(T) was determined to be 38.2 mol%. On the basis of phylogenetic, phenotypic and genetic data obtained in this study, strain T7(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium buctense sp. nov. is proposed. The type strain is T7(T) (=JCM 30750=CGMCC 1.15216). PMID:26374244

  8. Croceicoccus naphthovorans sp. nov., a polycyclic aromatic hydrocarbons-degrading and acylhomoserine-lactone-producing bacterium isolated from marine biofilm, and emended description of the genus Croceicoccus.

    PubMed

    Huang, Yili; Zeng, Yanhua; Feng, Hao; Wu, Yuehong; Xu, Xuewei

    2015-05-01

    A polycyclic aromatic hydrocarbons-degrading and acylhomoserine-lactone-producing marine bacterium, designated strain PQ-2(T), was isolated from marine biofilm collected from a boat shell at a harbour of Zhoushan island in Zhejiang Province, PR China. Strain PQ-2(T) is Gram-stain-negative, yellow-pigmented, non-motile and short rod-shaped. Optimal growth of strain PQ-2(T) was observed at 32 °C, at pH 7.0 and in 2% (w/v) NaCl. The 16S rRNA gene sequence of strain PQ-2(T) showed highest similarity to Croceicoccus marinus E4A9(T) (96.3%) followed by Novosphingobium malaysiense MUSC 273(T) (95.6%) and Altererythrobacter marinus H32(T) (95.6%). Phylogenetic analysis with all species of the family Erythrobacteraceae with validly published names revealed that strain PQ-2(T) formed a phyletic line with Croceicoccus marinus E4A9(T) that was distinct from other members of the family Erythrobacteraceae . The sole respiratory quinone was ubiquinone 10 (Q-10). The predominant fatty acids were C18 : 1?7c, C17 : 1?6c and summed feature 3 (C16 : 1?7c and/or iso-C15 : 0 2-OH). The genomic DNA G+C content was 61.7 mol%. In the polar lipid profile, phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, one unidentified phospholipid and one sphingoglycolipid were the major compounds; and another sphingoglycolipid was present in a minor amount. Based on the genotypic and phenotypic data, strain PQ-2(T) represents a novel species of the genus Croceicoccus , for which the name Croceicoccus naphthovorans sp. nov. is proposed. The type strain is PQ-2(T) (?=CGMCC 1.12805(T)?=NBRC 110381(T)). In addition, emended descriptions for the genus Croceicoccus and the species C. marinus are given. PMID:25713040

  9. Hafnia psychrotolerans sp. nov., isolated from lake water.

    PubMed

    Gu, Zhengquan; Liu, Yongqin; Shen, Liang; Liu, Xiaobo; Xiao, Na; Jiao, Nianzhi; Liu, Hongcan; Zhou, Yuguang; Zhang, Shuhong

    2015-03-01

    A psychrotolerant, Gram-stain-negative, motile, aerobic, peritrichous bacterium, strain DJC1-1(T), was isolated from Lake Dajiaco, Tibetan Plateau, China. The strain was negative for citrate utilization, lipase activity and ?-glucosidase, but positive for the Voges-Proskauer reaction and N-acetyl-?-glucosaminidase. 16S rRNA gene sequence analysis indicated that Hafnia paralvei ATCC 29927(T), Hafnia alvei ATCC 13337(T), Serratia grimesii DSM 30063(T) and Serratia plymuthica DSM 4540(T) were the closest relatives of strain DJC1-1(T), with similarities of 97.76, 96.80, 97.71 and 97.58?%, respectively. The DNA G+C content of strain DJC1-1(T) was 53.9 mol%. The predominant fatty acids were C16?:?0 and C17?:?0 cyclo. Based on these characteristics, strain DJC1-1(T) can be assigned to the genus Hafnia. In DNA-DNA hybridization tests, strain DJC1-1(T) shared 50.6, 35.1, 36.5 and 18.1?% DNA-DNA relatedness with the type strains of H. paralvei, H. alvei, S. grimesii and S. plymuthica, respectively. The growth temperature ranged from 0 to 40 °C, with optimum growth at 15 °C. Physiological and biochemical tests differentiated strain DJC1-1(T) from the type strains of recognized species of the genus Hafnia. Therefore, strain DJC1-1(T) is identified as representing a novel species of the genus Hafnia, for which the name Hafnia psychrotolerans sp. nov. is proposed. The type strain is DJC1-1(T) (?=?JCM 30077(T)?=?CGMCC1.12806(T)). PMID:25563917

  10. Actinoallomurus bryophytorum sp. nov., an endophytic actinomycete isolated from moss (Bryophyta).

    PubMed

    Li, Chuang; Wang, Haiyan; Jin, Pinjiao; Zheng, Weijia; Chu, Liyang; Liu, Chongxi; Li, Jiansong; Xiang, Wensheng; Wang, Xiangjing

    2015-08-01

    A novel endophytic actinomycete, strain NEAU-TX1-15(T), was isolated from moss, collected from Wuchang, Heilongjiang province, north China. A polyphasic taxonomic study was carried out to establish the status of strain NEAU-TX1-15(T). Morphological and chemotaxonomic properties of strain NEAU-TX1-15(T) are consistent with the description of the genus Actinoallomurus. Strain NEAU-TX1-15(T) was observed to form short spiral or looped spore chains on aerial hyphae. The cell wall peptidoglycan was found to contain lysine and meso-diaminopimelic acid. The major menaquinones were identified as MK-9(H6) and MK-9(H8). The only phospholipid identified was phosphatidylglycerol. The major fatty acid was identified as iso-C16:0. Analysis of the 16S rRNA gene sequence supports the assignment of the novel strain to the genus Actinoallomurus, as it exhibits 99.2 % gene sequence similarity to that of Actinoallomurus yoronensis NBRC 103686(T). However, the low level of DNA-DNA relatedness allowed the strain to be differentiated from its close relative. Moreover, strain NEAU-TX1-15(T) could also be differentiated from A. yoronensis NBRC 103686(T) and other Actinoallomurus species showing high 16S rRNA gene sequence similarity (>98.0 %) by cultural and physiological characteristics. Therefore, the combination of phenotypic and chemotaxonomic data, and the DNA-DNA hybridization value, indicated that strain NEAU-TX1-15(T) represents a novel species of the genus Actinoallomurus for which the name Actinoallomurus bryophytorum sp. nov. is proposed. The type strain is NEAU-TX1-15(T) (=CGMCC 4.7200(T) = JCM 30340(T)). PMID:26033369

  11. Alcanivorax hongdengensis sp. nov., an alkane-degrading bacterium isolated from surface seawater of the straits of Malacca and Singapore, producing a lipopeptide as its biosurfactant.

    PubMed

    Wu, Yehui; Lai, Qiliang; Zhou, Zhongwen; Qiao, Nan; Liu, Chenli; Shao, Zongze

    2009-06-01

    A taxonomic study was carried out on strain A-11-3(T), which was isolated from an oil-enriched consortia from the surface seawater of Hong-Deng dock in the Straits of Malacca and Singapore. Cells were aerobic, Gram-negative, non-spore-forming irregular rods. The strain was catalase- and oxidase-negative. It grew on a restricted spectrum of organic compounds, including some organic acids and alkanes. 16S rRNA gene sequence comparisons showed that strain A-11-3(T) was most closely related to the type strains of Alcanivorax jadensis (96.8 % sequence similarity), Alcanivorax borkumensis (96.8 %), Alcanivorax dieselolei (94.8 %), Alcanivorax venustensis (94.2 %) and Alcanivorax balearicus (94.0 %). The predominant fatty acids were C(16 : 0) (31.2 %), C(18 : 1)omega7c (24.8 %), C(18 : 0) (9.6 %), C(12 : 0) (8.3 %), C(16 : 1)omega7c (8.3 %) and C(16 : 0) 3-OH (5.1 %). The G+C content of the genomic DNA was 54.7 mol%. Moreover, the strain produced lipopeptides as its surface-active compounds. According to physiological and biochemical tests, DNA-DNA hybridization results and sequence comparisons of the 16S-23S internal transcribed spacer, the gyrB gene and the alkane hydroxylase gene alkB1, strain A-11-3(T) was affiliated with the genus Alcanivorax but could be readily distinguished from recognized Alcanivorax species. Therefore strain A-11-3(T) represents a novel species of the genus Alcanivorax for which the name Alcanivorax hongdengensis sp. nov. is proposed. The type strain is A-11-3(T) (=CGMCC 1.7084(T)=LMG 24624(T)=MCCC 1A01496(T)). PMID:19502338

  12. Paenibacillus jilunlii sp. nov., a nitrogen-fixing species isolated from the rhizosphere of Begonia semperflorens.

    PubMed

    Jin, Hao-Jie; Zhou, Yu-Guang; Liu, Hong-Can; Chen, San-Feng

    2011-06-01

    A nitrogen-fixing bacterium, designated strain Be17(T), was isolated from rhizosphere soil of Begonia semperflorens planted in Beijing Botanical Garden, PR China. Phylogenetic analyses based on a segment of the nifH gene sequence and a full-length 16S rRNA gene sequence revealed that strain Be17(T) was a member of the genus Paenibacillus. High levels of 16S rRNA gene sequence similarity were found between strain Be17(T) and Paenibacillus graminis RSA19(T) (97.9 %), Paenibacillus sonchi LMG 24727(T) (97.8 %), Paenibacillus riograndensis CECT 7330(T) (96.2 %) and Paenibacillus borealis DSM 13188(T) (96.1 %), respectively. Levels of 16S rRNA gene sequence similarity between strain Be17(T) and the type strains of other recognized members of the genus Paenibacillus were below 96.0 %. However, the DNA-DNA hybridization values between strain Be17(T) and P. graminis RSA19(T), P. sonchi LMG 24727(T) and P. riograndensis CECT 7330(T) were 47.9 %, 38.7 % and 37.5 %, respectively. The DNA G+C content of strain Be17(T) was 52.9 mol%. The major fatty acid component of strain Be17(T) was anteiso-branched C(15 : 0) (30.92 %). The major isoprenoid quinone was MK-7. The cell-wall peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. On the basis of its phenotypic characteristics, 16S rRNA gene sequences, DNA G+C content, DNA-DNA relatedness, chemotaxonomic properties and nifH gene sequence, strain Be17(T) represents a nitrogen-fixing strain of a novel species of the genus Paenibacillus, for which the name Paenibacillus jilunlii sp. nov. is proposed. The type strain is Be17(T) (?=?CGMCC 1.10239(T)?=?DSM 23019(T)). PMID:20601486

  13. Tepidimicrobium xylanilyticum sp. nov., an anaerobic xylanolytic bacterium, and emended description of the genus Tepidimicrobium.

    PubMed

    Niu, Lili; Song, Lei; Liu, Xiaoli; Dong, Xiuzhu

    2009-11-01

    A novel, xylanolytic, anaerobic, moderately thermophilic bacterium, strain PML14(T), was isolated from the sludge of a thermophilic anaerobic digester treating municipal solid waste and sewage in Beijing, China. The strain was a Gram-positive, spore-forming and motile rod. Growth of the novel strain was observed at 25-67 degrees C (optimum 60 degrees C) and pH 5.8-9.3 (optimum pH 8.5). Strain PML14(T) grew on a number of carbohydrates, including xylan, xylose, glucose and cellobiose, and a variety of proteinaceous compounds, including peptone, tryptone, Casamino acids, yeast extract, beef extract, casein hydrolysate, l-cysteine, l-serine, l-lysine, l-glycine, l-threonine, l-methionine and pyruvate. The fermentation products from glucose included acetate, ethanol, butyrate, hydrogen and carbon dioxide. Propionate was produced from xylan in addition to other compounds. Fe(III), 9,10-anthraquinone 2,6-disulfonate and thiosulfate were reduced with peptone as the electron donor. NH(3) was produced. Indole was not produced. Gelatin was not hydrolysed. The DNA G+C content of strain PML14(T) was 36.2+/-0.8 mol% (T(m)). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain PML14(T) was related to the members of cluster XII of the clostridia, most closely to Tepidimicrobium ferriphilum SB91(T) with 93.8 % 16S rRNA gene sequence similarity. On the basis of polyphasic evidence from this study, it is suggested that strain PML14(T) (=CGMCC 1.5080(T)=JCM 15035(T)) represents a novel species of the genus Tepidimicrobium, for which the name Tepidimicrobium xylanilyticum sp. nov., is proposed. An emended description of the genus Tepidimicrobium is also provided. PMID:19625437

  14. Barrientosiimonas humi gen. nov., sp. nov., an actinobacterium of the family Dermacoccaceae.

    PubMed

    Lee, Learn-Han; Cheah, Yoke-Kqueen; Sidik, Shiran Mohd; Xie, Qing-Yi; Tang, Yi-Li; Lin, Hai-Peng; Mutalib, Nurul-Syakima Ab; Hong, Kui

    2013-01-01

    Three novel actinobacteria, strains 39(T), 40 and 41, were isolated from soil collected from Barrientos Island in the Antarctic. The taxonomic status of these strains was determined using a polyphasic approach. Comparison of 16S rRNA gene sequences revealed that strain 39(T) represented a novel lineage within the family Dermacoccaceae and was most closely related to members of the genera Demetria (96.9 % 16S rRNA gene sequence similarity), Branchiibius (95.7 %), Dermacoccus (94.4-95.3 %), Calidifontibacter (94.6 %), Luteipulveratus (94.3 %), Yimella (94.2 %) and Kytococcus (93.1 %). Cells were irregular cocci and short rods. The peptidoglycan type was A4? with an L-Lys-L-Ser-D-Asp interpeptide bridge. The cell-wall sugars were galactose and glucose. The major menaquinone was MK-8(H(4)). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphoglycolipid, two glycolipids and one unknown phospholipid. The acyl type of the cell-wall polysaccharide was N-acetyl. The major cellular fatty acids were anteiso-C(17 : 0) (41.97 %), anteiso-C(17 : 1)?9c (32.16 %) and iso-C(16 : 0) (7.68 %). The DNA G+C content of strain 39(T) was 68.4 mol%. On the basis of phylogenetic and phenotypic differences from other genera of the family Dermacoccaceae, a novel genus and species, Barrientosiimonas humi gen. nov., sp. nov., is proposed; the type strain of the type species is 39(T) (=CGMCC 4.6864(T) = DSM 24617(T)). PMID:22389286

  15. Oligosphaera ethanolica gen. nov., sp. nov., an anaerobic, carbohydrate-fermenting bacterium isolated from methanogenic sludge, and description of Oligosphaeria classis nov. in the phylum Lentisphaerae.

    PubMed

    Qiu, Yan-Ling; Muramatsu, Mizuho; Hanada, Satoshi; Kamagata, Yoichi; Guo, Rong-Bo; Sekiguchi, Yuji

    2013-02-01

    A mesophilic, obligately anaerobic, carbohydrate-fermenting bacterium, designated 8KG-4(T), was isolated from an upflow anaerobic sludge blanket reactor treating high-strength organic wastewater from salted vegetable production processes. Cells of strain 8KG-4(T) were non-motile, spherical and 0.7-1.5 µm in diameter (mean, 1.0 µm). Spore formation was not observed under any culture conditions tested. The strain grew optimally at 37 °C (range for growth 25-40 °C) and pH 7.0 (range, pH 6.5-7.5), and could grow fermentatively on glucose, ribose, xylose, galactose and sucrose. The main end products of glucose fermentation were acetate, ethanol and hydrogen. Organic acids, alcohols and amino acids were not utilized for growth. Yeast extract was not required for growth. Nitrate, sulfate, thiosulfate, elemental sulfur, sulfite and Fe(III) nitrilotriacetate were not used as terminal electron acceptors. The G+C content of the genomic DNA was 61.1 mol%. 16S rRNA gene sequence analysis revealed that the isolate represented a previously uncultured lineage at the subphylum level within the phylum Lentisphaerae known as 'WWE2 subgroup I'. The major cellular fatty acids were anteiso-C(15?:?0), iso-C(16?:?0), C(16?:?0) and anteiso-C(17?:?0). Respiratory quinones were not detected. The most abundant polar lipid of strain 8KG-4(T) was phosphatidylethanolamine. A novel genus and species, Oligosphaera ethanolica gen. nov., sp. nov., is proposed to accommodate strain 8KG-4(T) (?=?JCM 17152(T)?=?DSM 24202(T) ?=?CGMCC 1.5160(T)). In addition, we formally propose Oligosphaeria classis nov. and the subordinate taxa Oligosphaerales order nov. and Oligosphaeraceae fam. nov. PMID:22523166

  16. Algoriella xinjiangensis gen. nov., sp. nov., a new psychrotolerant bacterium of the family Flavobacteriaceae.

    PubMed

    Yang, Na; Zhang, Lixin; Sun, Chaomin

    2015-11-01

    An aerobic, Gram-stain negative, non-spore-forming and psychrotolerant bacterium, designated strain XJ109(T), was isolated from a sewage water sample collected from Xinjiang Uigur Autonomous Region, China. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain XJ109(T) represents a novel member of the family Flavobacteriaceae. The strain showed 95.5 % similarity with the 16S rRNA gene sequence of Empedobacter brevis LMG 4011(T), 95.4 % with Chishuiella changwenlii BY4(T), 95.3 % with Empedobacter falsenii NF 993(T) and 92.3 % with Weeksella virosa DSM 16922(T). Strain XJ109(T) showed the common phenotypic and chemotaxonomic characteristics of the family Flavobacteriaceae, containing menaquinone-6 (MK-6) as the predominant respiratory quinone and iso-C17:0 3OH and iso-C15:0 as the major fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, one unidentified phospholipid and two unidentified lipids. The genomic DNA G+C content was 38.0 mol%. Strain XJ109(T) was positive for catalase and oxidase activities, and it was observed to grow at 4-30 °C (optimal 16-20 °C), pH 6.5-10.0 (optimal 7.0-7.5) and in media containing 0-2.0 % (w/v) NaCl (optimal 0.5 %). On the basis of the polyphasic evidence presented, strain XJ109(T) is considered to represent a novel genus and species of the family Flavobacteriaceae, for which the name Algoriella xinjiangensis gen. nov., sp. nov. is proposed. The type strain is XJ109(T) (=CGMCC 1.10229(T)=JCM 16590(T)). PMID:26310805

  17. Eliminating aluminum toxicity in an acid sulfate soil for rice cultivation using plant growth promoting bacteria.

    PubMed

    Panhwar, Qurban Ali; Naher, Umme Aminun; Radziah, Othman; Shamshuddin, Jusop; Razi, Ismail Mohd

    2015-01-01

    Aluminum toxicity is widely considered as the most important limiting factor for plants growing in acid sulfate soils. A study was conducted in laboratory and in field to ameliorate Al toxicity using plant growth promoting bacteria (PGPB), ground magnesium limestone (GML) and ground basalt. Five-day-old rice seedlings were inoculated by Bacillus sp., Stenotrophomonas maltophila, Burkholderia thailandensis and Burkholderia seminalis and grown for 21 days in Hoagland solution (pH 4.0) at various Al concentrations (0, 50 and 100 ?M). Toxicity symptoms in root and leaf were studied using scanning electron microscope. In the field, biofertilizer (PGPB), GML and basalt were applied (4 t·ha-1 each). Results showed that Al severely affected the growth of rice. At high concentrations, the root surface was ruptured, leading to cell collapse; however, no damages were observed in the PGPB inoculated seedlings. After 21 days of inoculation, solution pH increased to >6.0, while the control treatment remained same. Field study showed that the highest rice growth and yield were obtained in the bio-fertilizer and GML treatments. This study showed that Al toxicity was reduced by PGPB via production of organic acids that were able to chelate the Al and the production of polysaccharides that increased solution pH. The release of phytohormones further enhanced rice growth that resulted in yield increase. PMID:25710843

  18. Bacterial Diversity and Community Structure in the Pine Wood Nematode Bursaphelenchus xylophilus and B. mucronatus with Different Virulence by High-Throughput Sequencing of the 16S rDNA

    PubMed Central

    Xiang, Yang; Wu, Xiao-Qin; Zhou, Ai-Dong

    2015-01-01

    Bursaphelenchus xylophilus is the pathogen of pine wilt disease. Bursaphelenchus mucronatus is similar to B. xylophilus in morphology. Both species share a common niche, but they are quite different in pathogenicity. Presently, the role of bacteria in pine wilt disease development has been widely speculated. The diversity of bacteria associated with B. xylophilus and B. mucronatus with different virulence remains unclear. In this study, virulence of four B. xylophilus and four B. mucronatus strains were evaluated by inoculating Pinus thunbergii. High-throughput sequencing targeted 16S rDNA of different virulence nematode strains was carried out. The associated bacterial community structures of the eight strains were analyzed. The results showed that 634,051 high-quality sequences were obtained from the eight nematode strains. The number of OTUs of bacteria associated with B. mucronatus was generally greater than those of B. xylophilus. The richness of the community of bacteria associated with high virulent B. xylophilus ZL1 and AmA3 was higher than moderately virulent B. xylophilus AA3, HE2, and all B. mucronatus strains. While the diversity of bacteria associated with B. mucronatus was higher than B. xylophilus. Stenotrophomonas, Pseudomonadaceae_Unclassified or Rhizobiaceae_Unclassified were predominant in the nematode strains with different virulence. Oxalobacteraceae and Achromobacter were found more abundant in the low virulent B. xylophilus and non-virulent B. mucronatus strains. PMID:26372013

  19. The Analysis of a Microbial Community in the UV/O3-Anaerobic/Aerobic Integrated Process for Petrochemical Nanofiltration Concentrate (NFC) Treatment by 454-Pyrosequencing.

    PubMed

    Wei, Chao; He, Wenjie; Wei, Li; Li, Chunying; Ma, Jun

    2015-01-01

    In this study, high-throughput pyrosequencing was applied on the analysis of the microbial community of activated sludge and biofilm in a lab-scale UV/O3- anaerobic/aerobic (A/O) integrated process for the treatment of petrochemical nanofiltration concentrate (NFC) wastewater. NFC is a type of saline wastewater with low biodegradability. From the anaerobic activated sludge (Sample A) and aerobic biofilm (Sample O), 59,748 and 51,231 valid sequence reads were obtained, respectively. The dominant phylotypes related to the metabolism of organic compounds, polycyclic aromatic hydrocarbon (PAH) biodegradation, assimilation of carbon from benzene, and the biodegradation of nitrogenous organic compounds were detected as genus Clostridium, genera Pseudomonas and Stenotrophomonas, class Betaproteobacteria, and genus Hyphomicrobium. Furthermore, the nitrite-oxidising bacteria Nitrospira, nitrite-reducing and sulphate-oxidising bacteria (NR-SRB) Thioalkalivibrio were also detected. In the last twenty operational days, the total Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) removal efficiencies on average were 64.93% and 62.06%, respectively. The removal efficiencies of ammonia nitrogen and Total Nitrogen (TN) on average were 90.51% and 75.11% during the entire treatment process. PMID:26461260

  20. Exploiting the fungal highway: development of a novel tool for the in situ isolation of bacteria migrating along fungal mycelium.

    PubMed

    Simon, Anaele; Bindschedler, Saskia; Job, Daniel; Wick, Lukas Y; Filippidou, Sevasti; Kooli, Wafa M; Verrecchia, Eric P; Junier, Pilar

    2015-11-01

    Fungi and bacteria form various associations that are central to numerous environmental processes. In the so-called fungal highway, bacteria disperse along fungal mycelium. We developed a novel tool for the in situ isolation of bacteria moving along fungal hyphae as well as for the recovery of fungi potentially involved in dispersal, both of which are attracted towards a target culture medium. We present the validation and the results of the first in situ test. Couples of fungi and bacteria were isolated from soil. Amongst the enriched organisms, we identified several species of fast-growing fungi (Fusarium sp. and Chaetomium sp.), as well as various potentially associated bacterial groups, including Variovorax soli, Olivibacter soli, Acinetobacter calcoaceticus, and several species of the genera Stenotrophomonas, Achromobacter and Ochrobactrum. Migration of bacteria along fungal hyphae across a discontinuous medium was confirmed in most of the cases. Although the majority of the bacteria for which migration was confirmed were also positive for flagellar motility, not all motile bacteria dispersed using their potential fungal partner. In addition, the importance of hydrophobicity of the fungal mycelial surface was confirmed. Future applications of the columns include targeting different types of microorganisms and their interactions, either by enrichment or by state of the art molecular biological methods. PMID:26432804

  1. Isolation and initial characterization of a novel type of Baeyer-Villiger monooxygenase activity from a marine microorganism.

    PubMed

    Willetts, Andrew; Joint, Ian; Gilbert, Jack A; Trimble, William; Mühling, Martin

    2012-07-01

    A novel type of Baeyer-Villiger monooxygenase (BVMO) has been found in a marine strain of Stenotrophomonas maltophila strain PML168 that was isolated from a temperate intertidal zone. The enzyme is able to use NADH as the source of reducing power necessary to accept the atom of diatomic oxygen not incorporated into the oxyfunctionalized substrate. Growth studies have establish that the enzyme is inducible, appears to serve a catabolic role, and is specifically induced by one or more unidentified components of seawater as well as various anthropogenic xenobiotic compounds. A blast search of the primary sequence of the enzyme, recovered from the genomic sequence of the isolate, has placed this atypical BVMO in the context of the several hundred known members of the flavoprotein monooxygenase superfamily. A particular feature of this BVMO lies in its truncated C-terminal domain, which results in a relatively small protein (357 amino acids; 38.4?kDa). In addition, metagenomic screening has been conducted on DNA recovered from an extensive range of marine environmental samples to gauge the relative abundance and distribution of similar enzymes within the global marine microbial community. Although low, abundance was detected in samples from many marine provinces, confirming the potential for biodiscovery in marine microorganisms. PMID:22414193

  2. Plant-microbe interactions promoting plant growth and health: perspectives for controlled use of microorganisms in agriculture.

    PubMed

    Berg, Gabriele

    2009-08-01

    Plant-associated microorganisms fulfill important functions for plant growth and health. Direct plant growth promotion by microbes is based on improved nutrient acquisition and hormonal stimulation. Diverse mechanisms are involved in the suppression of plant pathogens, which is often indirectly connected with plant growth. Whereas members of the bacterial genera Azospirillum and Rhizobium are well-studied examples for plant growth promotion, Bacillus, Pseudomonas, Serratia, Stenotrophomonas, and Streptomyces and the fungal genera Ampelomyces, Coniothyrium, and Trichoderma are model organisms to demonstrate influence on plant health. Based on these beneficial plant-microbe interactions, it is possible to develop microbial inoculants for use in agricultural biotechnology. Dependent on their mode of action and effects, these products can be used as biofertilizers, plant strengtheners, phytostimulators, and biopesticides. There is a strong growing market for microbial inoculants worldwide with an annual growth rate of approximately 10%. The use of genomic technologies leads to products with more predictable and consistent effects. The future success of the biological control industry will benefit from interdisciplinary research, e.g., on mass production, formulation, interactions, and signaling with the environment, as well as on innovative business management, product marketing, and education. Altogether, the use of microorganisms and the exploitation of beneficial plant-microbe interactions offer promising and environmentally friendly strategies for conventional and organic agriculture worldwide. PMID:19568745

  3. Isolation, characterization and community diversity of indigenous putative toluene-degrading bacterial populations with catechol-2,3-dioxygenase genes in contaminated soils.

    PubMed

    Olapade, Ola A; Ronk, Adam J

    2015-01-01

    Indigenous bacterial assemblages with putative hydrocarbon-degrading capabilities were isolated, characterized and screened for the presence of the catechol-2,3-dioxygenase (C23O) gene after exposure to toluene in two different (i.e., pristine and conditioned) soil communities. The indigenous bacterial populations were exposed to the hydrocarbon substrate by the addition of toluene concentrations, ranging from 0.5 % to 10 % V/W in 10 g of each soil and incubated at 30 °C for upwards of 12 days. In total, 25 isolates (11 in pristine soil and 14 in conditioned soil) were phenotypically characterized according to standard microbiological methods and also screened for the 238-bp C23O gene fragment. Additionally, 16S rRNA analysis of the isolates identified some of them as belonging to the genera Bacillus, Exiguobacterium, Enterobacter, Pseudomonas and Stenotrophomonas. Furthermore, the two clone libraries that were constructed from these toluene-contaminated soils also revealed somewhat disparate phylotypes (i.e., 70 % Actinobacteria and Firmicutes to 30 % Proteobacteria in conditioned soil, whereas in pristine soil: 66 % Actinobacteria and Firmicutes; 21 % Proteobacteria and 13 % Bacteroidetes). The differences observed in bacterial phylotypes between these two soil communities may probably be associated with previous exposure to hydrocarbon sources by indigenous populations in the conditioned soil as compared to the pristine soil. PMID:25052383

  4. Herbivore exploits orally secreted bacteria to suppress plant defenses.

    PubMed

    Chung, Seung Ho; Rosa, Cristina; Scully, Erin D; Peiffer, Michelle; Tooker, John F; Hoover, Kelli; Luthe, Dawn S; Felton, Gary W

    2013-09-24

    Induced plant defenses in response to herbivore attack are modulated by cross-talk between jasmonic acid (JA)- and salicylic acid (SA)-signaling pathways. Oral secretions from some insect herbivores contain effectors that overcome these antiherbivore defenses. Herbivores possess diverse microbes in their digestive systems and these microbial symbionts can modify plant-insect interactions; however, the specific role of herbivore-associated microbes in manipulating plant defenses remains unclear. Here, we demonstrate that Colorado potato beetle (Leptinotarsa decemlineata) larvae exploit bacteria in their oral secretions to suppress antiherbivore defenses in tomato (Solanum lycopersicum). We found that antibiotic-untreated larvae decreased production of JA and JA-responsive antiherbivore defenses, but increased SA accumulation and SA-responsive gene expression. Beetles benefit from down-regulating plant defenses by exhibiting enhanced larval growth. In SA-deficient plants, suppression was not observed, indicating that suppression of JA-regulated defenses depends on the SA-signaling pathway. Applying bacteria isolated from larval oral secretions to wounded plants confirmed that three microbial symbionts belonging to the genera Stenotrophomonas, Pseudomonas, and Enterobacter are responsible for defense suppression. Additionally, reinoculation of these bacteria to antibiotic-treated larvae restored their ability to suppress defenses. Flagellin isolated from Pseudomonas sp. was associated with defense suppression. Our findings show that the herbivore exploits symbiotic bacteria as a decoy to deceive plants into incorrectly perceiving the threat as microbial. By interfering with the normal perception of herbivory, beetles can evade antiherbivore defenses of its host. PMID:24019469

  5. Exposure of Cucurbita pepo to DDE-contamination alters the endophytic community: A cultivation dependent vs a cultivation independent approach.

    PubMed

    Eevers, N; Hawthorne, J R; White, J C; Vangronsveld, J; Weyens, N

    2016-02-01

    2,2-bis(p-chlorophenyl)-1,1-dichloro-ethylene (DDE) is the most abundant and persistent degradation product of the pesticide 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) and is encountered in contaminated soils worldwide. Both DDE and DDT are classified as Persistent Organic Pollutants (POPs) due to their high hydrophobicity and potential for bioaccumulation and biomagnification in the food chain. Zucchini (Cucurbita pepo ssp. pepo) has been shown to accumulate high concentrations of DDE and other POPs and has been proposed as a phytoremediation tool for contaminated soils. The endophytic bacteria associated with this plant may play an important role in the remedial process. Therefore, this research focuses on changes in endophytic bacterial communities caused by the exposure of C. pepo to DDE. The total bacterial community was investigated using cultivation-independent 454 pyrosequencing, while the cultivable community was identified using cultivation-dependent isolation procedures. For both procedures, increasing numbers of endophytic bacteria, as well as higher diversities of genera were observed when plants were exposed to DDE. Several bacterial genera such as Stenotrophomonas sp. and Sphingomonas sp. showed higher abundance when DDE was present, while, for example Pseudomonas sp. showed a significantly lower abundance in the presence of DDE. These findings suggest tolerance of different bacterial strains to DDE, which might be incorporated in further investigations to optimize phytoremediation with the possible use of DDE-degrading endophytes. PMID:26683261

  6. Characterization of the pigment xanthomonadin in the bacterial genus Xanthomonas using micro- and resonance Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Paret, Mathews L.; Sharma, Shiv K.; Misra, Anupam K.; Acosta, Tayro; deSilva, Asoka S.; Vowell, Tomie; Alvarez, Anne M.

    2012-06-01

    We used micro- and resonance Raman spectroscopy with 785 nm and 514.5 nm laser excitation, respectively, to characterize a plant pathogenic bacteria, Xanthomonas axonopodis pv. dieffenbachiae D150. The bacterial genus Xathomonas is closely related to bacterial genus Stenotrophomonas that causes an infection in humans. This study has identified for the first time the unique Raman spectra of the carotenoid-like pigment xanthomonadin of the Xanthomonas strain. Xanthomonadin is a brominated aryl-polyene pigment molecule similar to carotenoids. Further studies were conducted using resonance Raman spectroscopy with 514.5 nm laser excitation on several strains of the bacterial genus Xanthomonas isolated from numerous plants from various geographical locations. The current study revealed that the Raman bands representing the vibrations (v1, v2, v3) of the polyene chain of xanthomonadin are 1003-1005 (v3), 1135-1138 (v2), and 1530 (v1). Overtone bands representing xanthomonadin were identified as 2264-2275 (2v2), and combinational bands at 2653-2662 (v1+ v2). The findings from this study validate our previous finding that the Raman fingerprints of xanthomonadin are unique for the genus Xanthomonas. This facilitates rapid identification (~5 minutes) of Xanthomonas spp. from bacterial culture plates. The xanthomonadin marker is different from Raman markers of many other bacterial genus including Agrobacterium, Bacillus, Clavibacter, Enterobacter, Erwinia, Microbacterium, Paenibacillus, and Ralstonia. This study also identified Xanthomonas spp. from bacterial strains isolated from a diseased wheat sample on a culture plate.

  7. [Activated Sludge Bacteria Transforming Cyanopyridines and Amides of Pyridinecarboxylic Acids].

    PubMed

    Demakov, V A; Vasil'ev, D M; Maksimova, Yu G; Pavlova, Yu A; Ovechkina, G V; Maksimov, A Yu

    2015-01-01

    Species diversity of bacteria from the activated sludge of Perm biological waste treatment facilities capable of transformation of cyanopyridines and amides of pyridinecarboxylic acids was investigated. Enrichment cultures in mineral media with 3-cyanopyridine as the sole carbon and nitrogen source were used to obtain 32 clones of gram-negative heterotrophic bacteria exhibiting moderate growth on solid and liquid media with 3- and 4-cyanopyridine. Sequencing of the 16S rRNA gene fragments revealed that the clones with homology of at least 99% belonged to the genera Acinetobacte, Alcaligenes, Delftia, Ochrobactrum, Pseudomonas, Stenotrophomonas, and Xanthobacter. PCR analysis showed that 13 out of 32 isolates contained the sequences (-1070 bp) homologous to the nitrilase genes reported previously in Alcaligenes faecalis JM3 (GenBank, D13419.1). Nine clones were capable of nitrile and amide transformation in minimal salt medium. Acinetobacter sp. 11 h and Alcaligenes sp. osv transformed 3-cyanopyridine to nicotinamide, while most of the clones possessed amidase activity (0.5 to 46.3 mmol/(g h) for acetamide and 0.1 to 5.6 mmol/(g h) for nicotinamide). Nicotinamide utilization by strain A. faecalis 2 was shown to result in excretion of a secondary metabolite, which was identified as dodecyl acrylate at 91% probability. PMID:26263697

  8. Conjugative transfer of a derivative of the IncP-1? plasmid RP4 and establishment of transconjugants in the indigenous bacterial community of poplar plants

    PubMed Central

    Ulrich, Andreas; Becker, Regina; Ulrich, Kristina; Ewald, Dietrich

    2015-01-01

    The persistence of traits introduced into the indigenous bacterial community of poplar plants was investigated using bioluminescence mediated by the luc gene. Three endophytic bacterial strains provided with the IncP-1? plasmid RP4-Tn-luc were used to inoculate poplar cuttings at different phenological stages. Screening of isolates by bioluminescence and real-time PCR detection of the luc gene revealed stable persistence for at least 10 weeks. Although the inoculated strains became established with a high population density after inoculation at leaf development (April) and senescence (October), the strains were suppressed by the indigenous bacteria at stem elongation (June). Transconjugants could be detected only at this phenological stage. Indigenous bacteria harbouring RP4-Tn-luc became established with densities ranging from 2 × 105 to 9 × 106 CFU g?1 fresh weight 3 and 10 weeks after inoculation. The increased colonization of the cuttings by indigenous bacteria at stem elongation seemed to strongly compete with the introduced strains. Otherwise, the phenological stage of the plants as well as the density of the indigenous recipients could serve as the driver for a more frequent conjugative plasmid transfer. A phylogenetic assignment of transconjugants indicated the transfer of RP4-Tn-luc into six genera of Proteobacteria, mainly Sphingomonas, Stenotrophomonas and Xanthomonas. PMID:26490946

  9. Long Term Performance of an Arsenite-Oxidizing-Chlorate-Reducing Microbial Consortium in an Upflow Anaerobic Sludge Bed (UASB) Bioreactor

    PubMed Central

    Sun, Wenjie; Sierra-Alvarez, Reyes; Field, Jim A.

    2011-01-01

    A chlorate (ClO3?) reducing microbial consortium oxidized arsenite (As(III)) to arsenate (As(V)) in an upflow anaerobic sludge-bed bioreactor over 550 d operation. As(III) was converted with high conversion efficiencies (>98%) at volumetric loadings ranging from 0.45 to 1.92 mmol As/(Lreactor d). The oxidation of As(III) was linked to the complete reduction of ClO3? to Cl? and H2O, as demonstrated by a molar ratio of approximately 3.0 mol As(III) oxidized per mole of Cl? formed and by the greatly lowered ClO3?-reducing capacity without As(III) feeding. An autotrophic enrichment culture was established from the bioreactor biofilm. A 16S rRNA gene clone library indicated that the culture was dominated by Dechloromonas, and Stenotrophomonas as well as genera within the family Comamonadaceae. The results indicate that the oxidation of As(III) to less mobile As(V) utilizing ClO3? as a terminal electron acceptor provides a sustainable bioremediation strategy for arsenic contamination in anaerobic environments. PMID:21333531

  10. Calcite Biomineralization by Bacterial Isolates from the Recently Discovered Pristine Karstic Herrenberg Cave

    PubMed Central

    Rusznyák, Anna; Akob, Denise M.; Nietzsche, Sándor; Eusterhues, Karin; Totsche, Kai Uwe; Neu, Thomas R.; Frosch, Torsten; Popp, Jürgen; Keiner, Robert; Geletneky, Jörn; Katzschmann, Lutz; Schulze, Ernst-Detlef

    2012-01-01

    Karstic caves represent one of the most important subterranean carbon storages on Earth and provide windows into the subsurface. The recent discovery of the Herrenberg Cave, Germany, gave us the opportunity to investigate the diversity and potential role of bacteria in carbonate mineral formation. Calcite was the only mineral observed by Raman spectroscopy to precipitate as stalactites from seepage water. Bacterial cells were found on the surface and interior of stalactites by confocal laser scanning microscopy. Proteobacteria dominated the microbial communities inhabiting stalactites, representing more than 70% of total 16S rRNA gene clones. Proteobacteria formed 22 to 34% of the detected communities in fluvial sediments, and a large fraction of these bacteria were also metabolically active. A total of 9 isolates, belonging to the genera Arthrobacter, Flavobacterium, Pseudomonas, Rhodococcus, Serratia, and Stenotrophomonas, grew on alkaline carbonate-precipitating medium. Two cultures with the most intense precipitate formation, Arthrobacter sulfonivorans and Rhodococcus globerulus, grew as aggregates, produced extracellular polymeric substances (EPS), and formed mixtures of calcite, vaterite, and monohydrocalcite. R. globerulus formed idiomorphous crystals with rhombohedral morphology, whereas A. sulfonivorans formed xenomorphous globular crystals, evidence for taxon-specific crystal morphologies. The results of this study highlighted the importance of combining various techniques in order to understand the geomicrobiology of karstic caves, but further studies are needed to determine whether the mineralogical biosignatures found in nutrient-rich media can also be found in oligotrophic caves. PMID:22179248

  11. Effect of chemotherapy on the microbiota and metabolome of human milk, a case report

    PubMed Central

    2014-01-01

    Background Human milk is an important source of bacteria for the developing infant and has been shown to influence the bacterial composition of the neonatal gut, which in turn can affect disease risk later in life. Human milk is also an important source of nutrients, influencing bacterial composition but also directly affecting the host. While recent studies have emphasized the adverse effects of antibiotic therapy on the infant microbiota, the effects of maternal chemotherapy have not been previously studied. Here we report the effects of drug administration on the microbiota and metabolome of human milk. Methods Mature milk was collected every two weeks over a four month period from a lactating woman undergoing chemotherapy for Hodgkin’s lymphoma. Mature milk was also collected from healthy lactating women for comparison. Microbial profiles were analyzed by 16S sequencing and the metabolome by gas chromatography–mass spectrometry. Findings Chemotherapy caused a significant deviation from a healthy microbial and metabolomic profile, with depletion of genera Bifidobacterium, Eubacterium, Staphylococcus and Cloacibacterium in favor of Acinetobacter, Xanthomonadaceae and Stenotrophomonas. The metabolites docosahexaenoic acid and inositol known for their beneficial effects were also decreased. Conclusion With milk contents being critical for shaping infant immunity and development, consideration needs to be given to the impact of drugs administered to the mother and the long-term potential consequences for the health of the infant. PMID:25061513

  12. Isolation and Identification of Cellulolytic Bacteria from the Gut of Holotrichia parallela Larvae (Coleoptera: Scarabaeidae)

    PubMed Central

    Huang, Shengwei; Sheng, Ping; Zhang, Hongyu

    2012-01-01

    In this study, 207 strains of aerobic and facultatively anaerobic cellulolytic bacteria were isolated from the gut of Holotrichia parallela larvae. These bacterial isolates were assigned to 21 genotypes by amplified ribosomal DNA restriction analysis (ARDRA). A partial 16S rDNA sequence analysis and standard biochemical and physiological tests were used for the assignment of the 21 representative isolates. Our results show that the cellulolytic bacterial community is dominated by the Proteobacteria (70.05%), followed by the Actinobacteria (24.15%), the Firmicutes (4.35%), and the Bacteroidetes (1.45%). At the genus level, Gram-negative bacteria including Pseudomonas, Ochrobactrum, Rhizobium, Cellulosimicrobium, and Microbacterium were the predominant groups, but members of Bacillus, Dyadobacter, Siphonobacter, Paracoccus, Kaistia, Devosia, Labrys, Ensifer, Variovorax, Shinella, Citrobacter, and Stenotrophomonas were also found. Furthermore, our results suggest that a significant amount of bacterial diversity exists among the cellulolytic bacteria, and that Siphonobacter aquaeclarae, Cellulosimicrobium funkei, Paracoccus sulfuroxidans, Ochrobactrum cytisi, Ochrobactrum haematophilum, Kaistia adipata, Devosia riboflavina, Labrys neptuniae, Ensifer adhaerens, Shinella zoogloeoides, Citrobacter freundii, and Pseudomonas nitroreducens are reported to be cellulolytic for the first time in this study. Our results indicate that the scarab gut is an attractive source for the study of novel cellulolytic microorganisms and enzymes useful for cellulose degradation. PMID:22489111

  13. Biogeochemical characterization of MC252 oil:sand aggregates on a coastal headland beach.

    PubMed

    Urbano, Marilany; Elango, Vijaikrishnah; Pardue, John H

    2013-12-15

    MC252 oil:sand aggregates, termed surface residue balls (SRBs), were sampled for physical, chemical and microbial characteristics from different tidal zones on a coastal headland beach in Louisiana, USA. Supratidal SRBs were smaller, had low moisture content, and salinities that were <2 ppt. Intertidal SRBs were hypersaline and had higher N and sulfate concentrations, consistent with regular tidal inundation. Crude oil components were highest in the intertidal "oil mat" SRBs with C1- and C2-phenanthrenes, C2- and C3-dibenzothiophenes comprising the majority of the PAH concentrations. In the other SRB categories, PAHs and alkanes were depleted and profiles were skewed toward higher molecular weight compounds. Oxygen microelectrode measurements demonstrated that saturated O2 is present immediately after wetting, but O2 consumption in the interior of the aggregate occurs after a few days. Microbial populations varied with position on the beach but sequences similar to known PAH-degrading taxa (Mycobacterium sp. and Stenotrophomonas sp.) were observed. PMID:24210008

  14. Exploration for facultative endosymbionts of glassy-wingedsharpshooter (Hemiptera: Cicadellidae)

    SciTech Connect

    Montllor-Curley, C.; Brodie, E.L.; Lechner, M.G.; Purcell, A.H.

    2006-07-01

    Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae),glassy-winged sharpshooter, was collected in California and severalstates in the southeastern United States in 2002 and 2003 and analyzedfor endosymbiotic bacteria. Hemolymph, eggs, and bacteriomes wereexamined for the presence of bacteria by polymerase chain reaction. Asubset of hemolymph and egg samples had their 16S rRNA gene ampliconscloned and sequenced or analyzed by restriction digest patterns ofsamples compared with known bacterial DNA. Baumannia cicadellinicola, oneof the primary symbionts of glassy-winged sharpshooter, was found in themajority of hemolymph samples, although it has been considered until nowto reside primarily inside the specialized host bacteriocytes. Wolbachiasp., a common secondary symbiont in many insect taxa investigated todate, was the second most frequently detected bacterium in hemolymphsamples. In addition, we detected bacteria that were most closely related(by 16S rRNA gene sequence) to Pseudomonas, Stenotrophomonas, andAcinetobacter in hemolymph samples of one and/or two glassy-wingedsharpshooters, but their origin is uncertain.

  15. Isolation and Screening of Rhizosphere Bacteria from Grasses in East Kavango Region of Namibia for Plant Growth Promoting Characteristics.

    PubMed

    Haiyambo, D H; Chimwamurombe, P M; Reinhold-Hurek, B

    2015-11-01

    A diverse group of soil bacteria known as plant growth promoting rhizobacteria (PGPR) is able to inhabit the area close to plant roots and exert beneficial effects on plant growth. Beneficial interactions between rhizospheric bacteria and plants provide prospects for isolating culturable PGPR that can be used as bio-fertilizers for sustainable crop production in communities that cannot easily afford chemical fertilizers. This study was conducted with the aim of isolating rhizospheric bacteria from grasses along the Kavango River and screening the bacterial isolates for plant growth promoting characteristics. The bacteria were isolated from rhizospheres of Phragmites australis, Sporobolus sp., Vetiveria nigritana, Pennisetum glaucum and Sorghum bicolor. The isolates were screened for inorganic phosphate solubilization, siderophore production and indole-3-acetic acid (IAA) production. The nitrogen-fixing capability of the bacteria was determined by screening for the presence of the nifH gene. Up to 21 isolates were obtained from P. australis, Sporobolus sp., S. bicolor, P. glaucum and V. nigritana. The genera Bacillus, Enterobacter, Kocuria, Pseudomonas and Stenotrophomonas, identified via 16S rDNA were represented in the 13 PGPR strains isolated. The isolates exhibited more than one plant growth promoting trait and they were profiled as follows: three phosphate solubilizers, four siderophore producers, eight IAA producing isolates and five nitrogen-fixers. These bacteria can be used to develop bio-fertilizer inoculants for improved soil fertility management and sustainable production of local cereals. PMID:26254764

  16. Antibiotic Resistance of Bacteria Isolated from the Internal Organs of Edible Snow Crabs

    PubMed Central

    Kim, Misoon; Kwon, Tae-Hyung; Jung, Su-Mi; Cho, Seung-Hak; Jin, Seon Yeong; Park, Nyun-Ho; Kim, Choong-Gon; Kim, Jong-Shik

    2013-01-01

    Antibiotic resistance and microbiota within edible snow crabs are important for the Chionoecetes (snow crab) fishing industry. We investigated these parameters using culture methods and antibiotic susceptibility tests with six internal organs from three species of Chionoecetes. Each sample revealed many unexpected microbial species within Chionoecetes internal organs. On the basis of 16S rRNA sequence analysis of 381 isolates, the most abundant genera identified in Chionoecetes opilio were Acinetobacter spp. (24%), Bacillus spp. (4%), Pseudomonas spp. (34%), Stenotrophomonas spp. (28%), and Agreia spp. (11%). In Chionoecetes sp. crabs, Acinetobacter spp. (23%), Bacillus spp. (12%), and Psychrobacter spp. (20%) were most prevalent, while Agreia spp. (11%), Bacillus spp. (31%), Microbacterium spp. (10%), Rhodococcus spp. (12%), and Agrococcus spp. (6%) were most abundant in C. japonicus. Our antibiotic resistance test found resistance to all nine antibiotics tested in 19, 14, and two of the isolates from C. opilio, Chionoecetes sp., and, C. japonicus respectively. Our results are the first to show that microbes with antibiotic resistance are widely distributed throughout the internal organs of natural snow crabs. PMID:23990916

  17. Isolation and initial characterization of a novel type of Baeyer–Villiger monooxygenase activity from a marine microorganism

    PubMed Central

    Willetts, Andrew; Joint, Ian; Gilbert, Jack A.; Trimble, William; Mühling, Martin

    2012-01-01

    Summary A novel type of Baeyer–Villiger monooxygenase (BVMO) has been found in a marine strain of Stenotrophomonas maltophila strain PML168 that was isolated from a temperate intertidal zone. The enzyme is able to use NADH as the source of reducing power necessary to accept the atom of diatomic oxygen not incorporated into the oxyfunctionalized substrate. Growth studies have establish that the enzyme is inducible, appears to serve a catabolic role, and is specifically induced by one or more unidentified components of seawater as well as various anthropogenic xenobiotic compounds. A blast search of the primary sequence of the enzyme, recovered from the genomic sequence of the isolate, has placed this atypical BVMO in the context of the several hundred known members of the flavoprotein monooxygenase superfamily. A particular feature of this BVMO lies in its truncated C?terminal domain, which results in a relatively small protein (357 amino acids; 38.4?kDa). In addition, metagenomic screening has been conducted on DNA recovered from an extensive range of marine environmental samples to gauge the relative abundance and distribution of similar enzymes within the global marine microbial community. Although low, abundance was detected in samples from many marine provinces, confirming the potential for biodiscovery in marine microorganisms. PMID:22414193

  18. Characterization of two-step deglycosylation via oxidation by glycoside oxidoreductase and defining their subfamily

    PubMed Central

    Kim, Eun-Mi; Seo, Joo-Hyun; Baek, Kiheon; Kim, Byung-Gee

    2015-01-01

    Herein, we report a two-step deglycosylation mediated by the oxidation of glycoside which is different from traditional glycoside hydrolase (GH) mechanism. Previously, we reported a novel flavin adenine dinucleotide (FAD)-dependent glycoside oxidoreductase (FAD-GO) having deglycosylation activity. Various features of the reaction of FAD-GO such as including mechanism and catalytic residue and substrate specificity were studied. In addition, classification of novel FAD-GO subfamily was attempted. Deglycosylation of glycoside was performed spontaneously via oxidation of 3-OH of glycone moiety by FAD-GO mediated oxidation reaction. His493 residue was identified as a catalytic residue for the oxidation step. Interestingly, this enzyme has broad glycone and aglycon specificities. For the classification of FAD-GO enzyme subfamily, putative FAD-GOs were screened based on the FAD-GO from Rhizobium sp. GIN611 (gi 365822256) using BLAST search. The homologs of R. sp. GIN611 included the putative FAD-GOs from Stenotrophomonas strains, Sphingobacterium strains, Agrobacterium tumefaciens str. C58, and etc. All the cloned FAD-GOs from the three strains catalyzed the deglycosylation via enzymatic oxidation. Based on their substrate specificities, deglycosylation and oxidation activities to various ginsenosides, the FAD-GO subfamily members can be utilized as novel biocatalysts for the production of various aglycones. PMID:26057169

  19. Bioremediation of heavy metal-contaminated effluent using optimized activated sludge bacteria

    NASA Astrophysics Data System (ADS)

    Bestawy, Ebtesam El.; Helmy, Shacker; Hussien, Hany; Fahmy, Mohamed; Amer, Ranya

    2013-03-01

    Removal of heavy metals from contaminated domestic-industrial effluent using eight resistant indigenous bacteria isolated from acclimatized activated sludge was investigated. Molecular identification using 16S rDNA amplification revealed that all strains were Gram-negative among which two were resistant to each of copper, cadmium and cobalt while one was resistant to each of chromium and the heavy metal mixture. They were identified as Enterobacter sp. (Cu1), Enterobacter sp. (Cu2), Stenotrophomonas sp. (Cd1), Providencia sp. (Cd2), Chryseobacterium sp. (Co1), Comamonas sp. (Co2), Ochrobactrum sp. (Cr) and Delftia sp. (M1) according to their resistance pattern. Strains Cu1, Cd1, Co2 and Cr were able to resist 275 mg Cu/l, 320 mg Cd/l, 140 mg Co/l and 29 mg Cr/l respectively. The four resistant strains were used as a mixture to remove heavy metals (elevated concentrations) and reduce the organic load of wastewater effluent. Results revealed that using the proposed activated sludge with the resistant bacterial mixture was more efficient for heavy metal removal compared to the activated sludge alone. It is therefore recommended that the proposed activated sludge system augmented with the acclimatized strains is the best choice to ensure high treatment efficiency and performance under metal stresses especially when industrial effluents are involved.

  20. The Analysis of a Microbial Community in the UV/O3-Anaerobic/Aerobic Integrated Process for Petrochemical Nanofiltration Concentrate (NFC) Treatment by 454-Pyrosequencing

    PubMed Central

    Wei, Chao; He, Wenjie; Wei, Li; Li, Chunying; Ma, Jun

    2015-01-01

    In this study, high-throughput pyrosequencing was applied on the analysis of the microbial community of activated sludge and biofilm in a lab-scale UV/O3- anaerobic/aerobic (A/O) integrated process for the treatment of petrochemical nanofiltration concentrate (NFC) wastewater. NFC is a type of saline wastewater with low biodegradability. From the anaerobic activated sludge (Sample A) and aerobic biofilm (Sample O), 59,748 and 51,231 valid sequence reads were obtained, respectively. The dominant phylotypes related to the metabolism of organic compounds, polycyclic aromatic hydrocarbon (PAH) biodegradation, assimilation of carbon from benzene, and the biodegradation of nitrogenous organic compounds were detected as genus Clostridium, genera Pseudomonas and Stenotrophomonas, class Betaproteobacteria, and genus Hyphomicrobium. Furthermore, the nitrite-oxidising bacteria Nitrospira, nitrite-reducing and sulphate-oxidising bacteria (NR-SRB) Thioalkalivibrio were also detected. In the last twenty operational days, the total Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) removal efficiencies on average were 64.93% and 62.06%, respectively. The removal efficiencies of ammonia nitrogen and Total Nitrogen (TN) on average were 90.51% and 75.11% during the entire treatment process. PMID:26461260

  1. Effects of bacterial inoculants on the indigenous microbiome and secondary metabolites of chamomile plants

    PubMed Central

    Schmidt, Ruth; Köberl, Martina; Mostafa, Amr; Ramadan, Elshahat M.; Monschein, Marlene; Jensen, Kenneth B.; Bauer, Rudolf; Berg, Gabriele

    2014-01-01

    Plant-associated bacteria fulfill important functions for plant growth and health. However, our knowledge about the impact of bacterial treatments on the host's microbiome and physiology is limited. The present study was conducted to assess the impact of bacterial inoculants on the microbiome of chamomile plants Chamomilla recutita (L.) Rauschert grown in a field under organic management in Egypt. Chamomile seedlings were inoculated with three indigenous Gram-positive strains (Streptomyces subrutilus Wbn2-11, Bacillus subtilis Co1-6, Paenibacillus polymyxa Mc5Re-14) from Egypt and three European Gram-negative strains (Pseudomonas fluorescens L13-6-12, Stenotrophomonas rhizophila P69, Serratia plymuthica 3Re4-18) already known for their beneficial plant-microbe interaction. Molecular fingerprints of 16S rRNA gene as well as real-time PCR analyses did not show statistically significant differences for all applied bacterial antagonists compared to the control. In contrast, a pyrosequencing analysis of the 16S rRNA gene libraries revealed significant differences in the community structure of bacteria between the treatments. These differences could be clearly shown by a shift within the community structure and corresponding beta-diversity indices. Moreover, B. subtilis Co1-6 and P. polymyxa Mc5Re-14 showed an enhancement of the bioactive secondary metabolite apigenin-7-O-glucoside. This indicates a possible new function of bacterial inoculants: to interact with the plant microbiome as well as to influence the plant metabolome. PMID:24600444

  2. Survey of Plant Drought-Resistance Promoting Bacteria from Populus euphratica Tree Living in Arid Area.

    PubMed

    Wang, Shanshan; Ouyang, Liming; Ju, Xiangyang; Zhang, Lili; Zhang, Qin; Li, Yanbin

    2014-12-01

    Two hundred and thirty-two bacterial strains were isolated from the rhizospheric soil of Populus euphratica which is the dominant tree living in extreme arid regions in northwest China. Some strains with plant growth-promoting bacteria related metabolic characteristics were able to promote drought resistance in plants after inoculation. Ten strains with the greatest effects increased the dry weight of wheat shoots from 0.5 to 34.4 %, and the surface area of the root systems from 12.56 to 212.17 % compared to the control after drought treatment whereas no obvious promoting effect was observed in normal water conditions. These 10 strains were identified to be of the genera Pseudomonas, Bacillus, Stenotrophomonas and Serratia by 16S rRNA (rrs) gene sequence alignment. Among these strains, Serratia sp. 1-9 and Pseudomonas sp. 5-23 were the two most effective strains. Both of them produced auxin and the production increased significantly when cultured under simulated drought conditions which are inferred to be the most plausible mechanism for their plant growth-promoting effect under drought stress. PMID:25320440

  3. Weakening Effect of Cell Permeabilizers on Gram-Negative Bacteria Causing Biodeterioration

    PubMed Central

    Alakomi, H.-L.; Paananen, A.; Suihko, M.-L.; Helander, I. M.; Saarela, M.

    2006-01-01

    Gram-negative bacteria play an important role in the formation and stabilization of biofilm structures on stone surfaces. Therefore, the control of growth of gram-negative bacteria offers a way to diminish biodeterioration of stone materials. The effect of potential permeabilizers on the outer membrane (OM) properties of gram-negative bacteria was investigated and further characterized. In addition, efficacy of the agents in enhancing the activity of a biocide (benzalkonium chloride) was assessed. EDTA, polyethylenimine (PEI), and succimer (meso-2,3-dimercaptosuccinic) were shown to be efficient permeabilizers of the members of Pseudomonas and Stenotrophomonas genera, as indicated by an increase in the uptake of a hydrophobic probe (1-N-phenylnaphthylamine) and sensitization to hydrophobic antibiotics. Visualization of Pseudomonas cells treated with EDTA or PEI by atomic force microscopy revealed damage in the outer membrane structure. PEI especially increased the surface area and bulges of the cells. Topographic images of EDTA-treated cells were compatible with events assigned for the effect of EDTA on outer membranes, i.e., release of lipopolysaccharide and disintegration of OM structure. In addition, the effect of EDTA treatment was visualized in phase-contrast images as large areas with varying hydrophilicity on cell surfaces. In liquid culture tests, EDTA and PEI supplementation enhanced the activity of benzalkonium chloride toward the target strains. Use of permeabilizers in biocide formulations would enable the use of decreased concentrations of the active biocide ingredient, thereby providing environmentally friendlier products. PMID:16820461

  4. Isolation of oxalotrophic bacteria able to disperse on fungal mycelium.

    PubMed

    Bravo, Daniel; Cailleau, Guillaume; Bindschedler, Saskia; Simon, Anaele; Job, Daniel; Verrecchia, Eric; Junier, Pilar

    2013-11-01

    A technique based on an inverted Petri dish system was developed for the growth and isolation of soil oxalotrophic bacteria able to disperse on fungal mycelia. The method is related to the 'fungal highways' dispersion theory in which mycelial fungal networks allow active movement of bacteria in soil. Quantification of this phenomenon showed that bacterial dispersal occurs preferentially in upper soil horizons. Eight bacteria and one fungal strain were isolated by this method. The oxalotrophic activity of the isolated bacteria was confirmed through calcium oxalate dissolution in solid selective medium. After separation of the bacteria-fungus couple, partial sequencing of the 16S and the ITS1 and ITS2 sequences of the ribosomal RNA genes were used for the identification of bacteria and the associated fungus. The isolated oxalotrophic bacteria included strains related to Stenotrophomonas, Achromobacter, Lysobacter, Pseudomonas, Agrobacterium, Cohnella, and Variovorax. The recovered fungus corresponded to Trichoderma sp. A test carried out to verify bacterial transport in an unsaturated medium showed that all the isolated bacteria were able to migrate on Trichoderma hyphae or glass fibers to re-colonize an oxalate-rich medium. The results highlight the importance of fungus-driven bacterial dispersal to understand the functional role of oxalotrophic bacteria and fungi in soils. PMID:24106816

  5. Ecobiotechnological strategy to enhance efficiency of bioconversion of wastes into hydrogen and methane.

    PubMed

    Kumar, Prasun; Pant, Dinesh Chander; Mehariya, Sanjeet; Sharma, Rishi; Kansal, Arun; Kalia, Vipin C

    2014-09-01

    Vegetable wastes (VW) and food wastes (FW) are generated in large quantities by municipal markets, restaurants and hotels. Waste slurries (250 ml) in 300 ml BOD bottles, containing 3, 5 and 7 % total solids (TS) were hydrolyzed with bacterial mixtures composed of: Bacillus, Acinetobacter, Exiguobacterium, Pseudomonas, Stenotrophomonas and Sphingobacterium species. Each of these bacteria had high activities for the hydrolytic enzymes: amylase, protease and lipase. Hydrolysate of biowaste slurries were subjected to defined mixture of H2 producers and culture enriched for methanogens. The impact of hydrolysis of VW and FW was observed as 2.6- and 2.8-fold enhancement in H2 yield, respectively. Direct biomethanation of hydrolysates of VW and FW resulted in 3.0- and 1.15-fold improvement in CH4 yield, respectively. A positive effect of hydrolysis was also observed with biomethanation of effluent of H2 production stage, to the extent of 1.2- and 3.5-fold with FW and VW, respectively. The effective H2 yields were 17 and 85 l/kg TS fed, whereas effective CH4 yields were 61.7 and 63.3 l/kg TS fed, from VW and FW, respectively. This ecobiotechnological strategy can help to improve the conversion efficiency of biowastes to biofuels. PMID:24891732

  6. Antibiofilm Activity of the Brown Alga Halidrys siliquosa against Clinically Relevant Human Pathogens

    PubMed Central

    Busetti, Alessandro; Thompson, Thomas P.; Tegazzini, Diana; Megaw, Julianne; Maggs, Christine A.; Gilmore, Brendan F.

    2015-01-01

    The marine brown alga Halidrys siliquosa is known to produce compounds with antifouling activity against several marine bacteria. The aim of this study was to evaluate the antimicrobial and antibiofilm activity of organic extracts obtained from the marine brown alga H. siliquosa against a focused panel of clinically relevant human pathogens commonly associated with biofilm-related infections. The partially fractionated methanolic extract obtained from H. siliquosa collected along the shores of Co. Donegal; Ireland; displayed antimicrobial activity against bacteria of the genus Staphylococcus; Streptococcus; Enterococcus; Pseudomonas; Stenotrophomonas; and Chromobacterium with MIC and MBC values ranging from 0.0391 to 5 mg/mL. Biofilms of S. aureus MRSA were found to be susceptible to the algal methanolic extract with MBEC values ranging from 1.25 mg/mL to 5 mg/mL respectively. Confocal laser scanning microscopy using LIVE/DEAD staining confirmed the antimicrobial nature of the antibiofilm activity observed using the MBEC assay. A bioassay-guided fractionation method was developed yielding 10 active fractions from which to perform purification and structural elucidation of clinically-relevant antibiofilm compounds. PMID:26058011

  7. Exploring characteristics of bioelectricity generation and dye decolorization of mixed and pure bacterial cultures from wine-bearing wastewater treatment.

    PubMed

    Han, Jing-Long; Liu, Ying; Chang, Chang-Tang; Chen, Bor-Yann; Chen, Wen-Ming; Xu, Hui-Zhong

    2011-04-01

    This study uncovered microbial characteristics of bioelectricity generation and dye decolorization in single-chamber microbial fuel cells (MFCs) using activated sludge for wine-containing wastewater treatment. Phylogenetic tree analysis on 16S rRNA gene fragments indicated that the predominant strains on anodic biofilm in acclimatized MFCs were Gamma-Proteobacteria Aeromonas punctata NIU-P9, Pseudomonas plecoglossicida NIU-Y3, Pseudomonas koreensis NIU-X8, Acinetobacter junii NIU-Y8, Stenotrophomonas maltophila NIU-X2. Our findings showed that the current production capabilities of these pure strains were only ca. 10% of those of their mother activated sludge, indicating that synergistic interactions among microbes might be the most influential factor to maximize power generation in MFCs. Plus, these electrochemically active strains also performed reductive decolorization of C.I. reactive blue 160, suggesting that bioelectricity generation might be directly associated to azo dye decolorization to deal with electron transfer on anodic biofilm in MFCs. PMID:20859654

  8. Conjugative transfer of a derivative of the IncP-1? plasmid RP4 and establishment of transconjugants in the indigenous bacterial community of poplar plants.

    PubMed

    Ulrich, Andreas; Becker, Regina; Ulrich, Kristina; Ewald, Dietrich

    2015-12-01

    The persistence of traits introduced into the indigenous bacterial community of poplar plants was investigated using bioluminescence mediated by the luc gene. Three endophytic bacterial strains provided with the IncP-1? plasmid RP4-Tn-luc were used to inoculate poplar cuttings at different phenological stages. Screening of isolates by bioluminescence and real-time PCR detection of the luc gene revealed stable persistence for at least 10 weeks. Although the inoculated strains became established with a high population density after inoculation at leaf development (April) and senescence (October), the strains were suppressed by the indigenous bacteria at stem elongation (June). Transconjugants could be detected only at this phenological stage. Indigenous bacteria harbouring RP4-Tn-luc became established with densities ranging from 2 × 10(5) to 9 × 10(6) CFU g(-1) fresh weight 3 and 10 weeks after inoculation. The increased colonization of the cuttings by indigenous bacteria at stem elongation seemed to strongly compete with the introduced strains. Otherwise, the phenological stage of the plants as well as the density of the indigenous recipients could serve as the driver for a more frequent conjugative plasmid transfer. A phylogenetic assignment of transconjugants indicated the transfer of RP4-Tn-luc into six genera of Proteobacteria, mainly Sphingomonas, Stenotrophomonas and Xanthomonas. PMID:26490946

  9. Herbivore exploits orally secreted bacteria to suppress plant defenses

    PubMed Central

    Chung, Seung Ho; Rosa, Cristina; Scully, Erin D.; Peiffer, Michelle; Tooker, John F.; Hoover, Kelli; Luthe, Dawn S.; Felton, Gary W.

    2013-01-01

    Induced plant defenses in response to herbivore attack are modulated by cross-talk between jasmonic acid (JA)- and salicylic acid (SA)-signaling pathways. Oral secretions from some insect herbivores contain effectors that overcome these antiherbivore defenses. Herbivores possess diverse microbes in their digestive systems and these microbial symbionts can modify plant–insect interactions; however, the specific role of herbivore-associated microbes in manipulating plant defenses remains unclear. Here, we demonstrate that Colorado potato beetle (Leptinotarsa decemlineata) larvae exploit bacteria in their oral secretions to suppress antiherbivore defenses in tomato (Solanum lycopersicum). We found that antibiotic-untreated larvae decreased production of JA and JA-responsive antiherbivore defenses, but increased SA accumulation and SA-responsive gene expression. Beetles benefit from down-regulating plant defenses by exhibiting enhanced larval growth. In SA-deficient plants, suppression was not observed, indicating that suppression of JA-regulated defenses depends on the SA-signaling pathway. Applying bacteria isolated from larval oral secretions to wounded plants confirmed that three microbial symbionts belonging to the genera Stenotrophomonas, Pseudomonas, and Enterobacter are responsible for defense suppression. Additionally, reinoculation of these bacteria to antibiotic-treated larvae restored their ability to suppress defenses. Flagellin isolated from Pseudomonas sp. was associated with defense suppression. Our findings show that the herbivore exploits symbiotic bacteria as a decoy to deceive plants into incorrectly perceiving the threat as microbial. By interfering with the normal perception of herbivory, beetles can evade antiherbivore defenses of its host. PMID:24019469

  10. Cross-utilization and expression of outer membrane receptor proteins for siderophore uptake by Diamondback moth Plutella xylostella (Lepidoptera: Plutellidae) gut bacteria.

    PubMed

    Indiragandhi, Pandiyan; Anandham, Rangasamy; Madhaiyan, Munusamy; Kim, Gil-Hah; Sa, Tongmin

    2008-12-01

    Siderophore production by entomo- and phytopathogens, plus the cross-utilization of these siderophores and expression of outer membrane receptor proteins (OMRPs) by Diamondback moth (DBM) gut bacterial strains, were all examined. All the tested strains grew in the presence of 2, 2'-dipyridyl, and the Brachybacterium sp. PSGB10, Pseudomonas sp. PRGB06, and Serratia marcescens FLGB16 strains were found to cross-utilize the siderophores of various entomopathogens, including Bacillus thuringiensis. A sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis also showed the presence of the OMRPs responsible for the siderophore cross-utilization. In contrast, Stenotrophomonas sp. PRGB08 was unable to cross-utilize siderophores and did not express OMRPs. Thus, siderophore cross-utilization and OMRP expression by the DBM gut bacterial strains would seem to support the potential for microbial populations in the insect gut to evolve efficient mechanisms to overcome any iron limitation imposed by the host insect and eventually contribute to the defense mechanism of the host insect. Furthermore, it is important to consider that other biologically active metabolites produced by insect gut microorganisms may also confer a protective effect on a host insect species. PMID:19054090

  11. Agroforestry leads to shifts within the gammaproteobacterial microbiome of banana plants cultivated in Central America.

    PubMed

    Köberl, Martina; Dita, Miguel; Martinuz, Alfonso; Staver, Charles; Berg, Gabriele

    2015-01-01

    Bananas (Musa spp.) belong to the most important global food commodities, and their cultivation represents the world's largest monoculture. Although the plant-associated microbiome has substantial influence on plant growth and health, there is a lack of knowledge of the banana microbiome and its influencing factors. We studied the impact of (i) biogeography, and (ii) agroforestry on the banana-associated gammaproteobacterial microbiome analyzing plants grown in smallholder farms in Nicaragua and Costa Rica. Profiles of 16S rRNA genes revealed high abundances of Pseudomonadales, Enterobacteriales, Xanthomonadales, and Legionellales. An extraordinary high diversity of the gammaproteobacterial microbiota was observed within the endophytic microenvironments (endorhiza and pseudostem), which was similar in both countries. Enterobacteria were identified as dominant group of above-ground plant parts (pseudostem and leaves). Neither biogeography nor agroforestry showed a statistically significant impact on the gammaproteobacterial banana microbiome in general. However, indicator species for each microenvironment and country, as well as for plants grown in Coffea intercropping systems with and without agri-silvicultural production of different Fabaceae trees (Inga spp. in Nicaragua and Erythrina poeppigiana in Costa Rica) could be identified. For example, banana plants grown in agroforestry systems were characterized by an increase of potential plant-beneficial bacteria, like Pseudomonas and Stenotrophomonas, and on the other side by a decrease of Erwinia. Hence, this study could show that as a result of legume-based agroforestry the indigenous banana-associated gammaproteobacterial community noticeably shifted. PMID:25717322

  12. Bacterial diversity in soil from geophagic mining sites in the Qwa-Qwa region of South Africa.

    PubMed

    de Smidt, Olga; Smit, Nellie Jacoba; Botes, Elsabe

    2015-01-01

    Geophagia is practised in many parts of the world and can be associated with medicinal treatments, ceremonial events and spiritual behaviours/practices. This is the first report on a systematic investigation and description of the bacterial diversity in soil regularly ingested by geophagic individuals using a culture-independent method. Diversity in 17 different mining sites was investigated using denaturing gradient gel electrophoresis. Genetic material from Pantoea, Stenotrophomonas, Listeria, Rhodococcus and Sphingomonads was present in most of the soil samples. Species from these genera are recognised, potential or immerging human pathogens, and are of special interest in immune-compromised individuals. Other genera able to produce a variety of bacteriocins and antimicrobial/antifungal substances inhibitory towards food borne pathogens (Dactylosporangium and Bacillus) and able to degrade a range of environmental pollutants and toxins (Duganella and Massilia) were also present. These essential insights provide the platform for adjusting culturing strategies to isolate specific bacteria, further phylogenetic studies and microbial mining prospect for bacterial species of possible economic importance. PMID:24852929

  13. Bacterial endophytic communities in the grapevine depend on pest management.

    PubMed

    Campisano, Andrea; Antonielli, Livio; Pancher, Michael; Yousaf, Sohail; Pindo, Massimo; Pertot, Ilaria

    2014-01-01

    Microbial plant endophytes are receiving ever-increasing attention as a result of compelling evidence regarding functional interaction with the host plant. Microbial communities in plants were recently reported to be influenced by numerous environmental and anthropogenic factors, including soil and pest management. In this study we used automated ribosomal intergenic spacer analysis (ARISA) fingerprinting and pyrosequencing of 16S rDNA to assess the effect of organic production and integrated pest management (IPM) on bacterial endophytic communities in two widespread grapevines cultivars (Merlot and Chardonnay). High levels of the dominant Ralstonia, Burkholderia and Pseudomonas genera were detected in all the samples We found differences in the composition of endophytic communities in grapevines cultivated using organic production and IPM. Operational taxonomic units (OTUs) assigned to the Mesorhizobium, Caulobacter and Staphylococcus genera were relatively more abundant in plants from organic vineyards, while Ralstonia, Burkholderia and Stenotrophomonas were more abundant in grapevines from IPM vineyards. Minor differences in bacterial endophytic communities were also found in the grapevines of the two cultivars. PMID:25387008

  14. Bacterial Endophytic Communities in the Grapevine Depend on Pest Management

    PubMed Central

    Campisano, Andrea; Antonielli, Livio; Pancher, Michael; Yousaf, Sohail; Pindo, Massimo; Pertot, Ilaria

    2014-01-01

    Microbial plant endophytes are receiving ever-increasing attention as a result of compelling evidence regarding functional interaction with the host plant. Microbial communities in plants were recently reported to be influenced by numerous environmental and anthropogenic factors, including soil and pest management. In this study we used automated ribosomal intergenic spacer analysis (ARISA) fingerprinting and pyrosequencing of 16S rDNA to assess the effect of organic production and integrated pest management (IPM) on bacterial endophytic communities in two widespread grapevines cultivars (Merlot and Chardonnay). High levels of the dominant Ralstonia, Burkholderia and Pseudomonas genera were detected in all the samples We found differences in the composition of endophytic communities in grapevines cultivated using organic production and IPM. Operational taxonomic units (OTUs) assigned to the Mesorhizobium, Caulobacter and Staphylococcus genera were relatively more abundant in plants from organic vineyards, while Ralstonia, Burkholderia and Stenotrophomonas were more abundant in grapevines from IPM vineyards. Minor differences in bacterial endophytic communities were also found in the grapevines of the two cultivars. PMID:25387008

  15. Bioremediation of Atmospheric Hydrocarbons via Bacteria Naturally Associated with Leaves of Higher Plants.

    PubMed

    Ali, N; Al-Awadhi, H; Dashti, N; Khanafer, M; El-Nemr, I; Sorkhoh, N; Radwan, S S

    2015-12-01

    Bacteria associated with leaves of sixteen cultivated and wild plant species from all over Kuwait were analyzed by a culture-independent approach. This technique depended on partial sequencing of 16S rDNA regions in total genomic DNA from the bacterial consortia and comparing the resulting sequences with those in the GenBank database. To release bacterial cells from leaves, tough methods such as sonication co-released too much leaf chloroplasts whose DNA interfered with the bacterial DNA. A more satisfactory bacterial release with a minimum of chloroplast co-release was done by gently rubbing the leaf surfaces with soft tooth brushes in phosphate buffer. The leaves of all plant species harbored on their surfaces bacterial communities predominated by hydrocarbonoclastic (hydrocarbon-utilizing) bacterial genera. Leaves of 6 representative plants brought about in the laboratory effective removal of volatile hydrocarbons in sealed microcosms. Each individual plant species had a unique bacterial community structure. Collectively, the phyllospheric microflora on the studied plants comprised the genera Flavobacterium, Halomonas, Arthrobacter, Marinobacter, Neisseria, Ralstonia, Ochrobactrum. Exiguobacterium, Planomicrobium, Propionibacterium, Kocuria, Rhodococcus and Stenotrophomonas. This community structure was dramatically different from the structure we determined earlier for the same plants using the culture-dependent approach, although in both cases, hydrocarbonoclastic bacteria were frequent. PMID:25946637

  16. Antibiofilm Activity of the Brown Alga Halidrys siliquosa against Clinically Relevant Human Pathogens.

    PubMed

    Busetti, Alessandro; Thompson, Thomas P; Tegazzini, Diana; Megaw, Julianne; Maggs, Christine A; Gilmore, Brendan F

    2015-06-01

    The marine brown alga Halidrys siliquosa is known to produce compounds with antifouling activity against several marine bacteria. The aim of this study was to evaluate the antimicrobial and antibiofilm activity of organic extracts obtained from the marine brown alga H. siliquosa against a focused panel of clinically relevant human pathogens commonly associated with biofilm-related infections. The partially fractionated methanolic extract obtained from H. siliquosa collected along the shores of Co. Donegal; Ireland; displayed antimicrobial activity against bacteria of the genus Staphylococcus; Streptococcus; Enterococcus; Pseudomonas; Stenotrophomonas; and Chromobacterium with MIC and MBC values ranging from 0.0391 to 5 mg/mL. Biofilms of S. aureus MRSA were found to be susceptible to the algal methanolic extract with MBEC values ranging from 1.25 mg/mL to 5 mg/mL respectively. Confocal laser scanning microscopy using LIVE/DEAD staining confirmed the antimicrobial nature of the antibiofilm activity observed using the MBEC assay. A bioassay-guided fractionation method was developed yielding 10 active fractions from which to perform purification and structural elucidation of clinically-relevant antibiofilm compounds. PMID:26058011

  17. Intraspecific differences in bacterial responses to modelled reduced gravity

    NASA Technical Reports Server (NTRS)

    Baker, P. W.; Leff, L. G.

    2005-01-01

    AIMS: Bacteria are important residents of water systems, including those of space stations which feature specific environmental conditions, such as lowered effects of gravity. The purpose of this study was to compare responses with modelled reduced gravity of space station, water system bacterial isolates with other isolates of the same species. METHODS AND RESULTS: Bacterial isolates, Stenotrophomonas paucimobilis and Acinetobacter radioresistens, originally recovered from the water supply aboard the International Space Station (ISS) were grown in nutrient broth under modelled reduced gravity. Their growth was compared with type strains S. paucimobilis ATCC 10829 and A. radioresistens ATCC 49000. Acinetobacter radioresistens ATCC 49000 and the two ISS isolates showed similar growth profiles under modelled reduced gravity compared with normal gravity, whereas S. paucimobilis ATCC 10829 was negatively affected by modelled reduced gravity. CONCLUSIONS: These results suggest that microgravity might have selected for bacteria that were able to thrive under this unusual condition. These responses, coupled with impacts of other features (such as radiation resistance and ability to persist under very oligotrophic conditions), may contribute to the success of these water system bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: Water quality is a significant factor in many environments including the ISS. Efforts to remove microbial contaminants are likely to be complicated by the features of these bacteria which allow them to persist under the extreme conditions of the systems.

  18. Bacterial Diversity and Community Structure in the Pine Wood Nematode Bursaphelenchus xylophilus and B. mucronatus with Different Virulence by High-Throughput Sequencing of the 16S rDNA.

    PubMed

    Xiang, Yang; Wu, Xiao-Qin; Zhou, Ai-Dong

    2015-01-01

    Bursaphelenchus xylophilus is the pathogen of pine wilt disease. Bursaphelenchus mucronatus is similar to B. xylophilus in morphology. Both species share a common niche, but they are quite different in pathogenicity. Presently, the role of bacteria in pine wilt disease development has been widely speculated. The diversity of bacteria associated with B. xylophilus and B. mucronatus with different virulence remains unclear. In this study, virulence of four B. xylophilus and four B. mucronatus strains were evaluated by inoculating Pinus thunbergii. High-throughput sequencing targeted 16S rDNA of different virulence nematode strains was carried out. The associated bacterial community structures of the eight strains were analyzed. The results showed that 634,051 high-quality sequences were obtained from the eight nematode strains. The number of OTUs of bacteria associated with B. mucronatus was generally greater than those of B. xylophilus. The richness of the community of bacteria associated with high virulent B. xylophilus ZL1 and AmA3 was higher than moderately virulent B. xylophilus AA3, HE2, and all B. mucronatus strains. While the diversity of bacteria associated with B. mucronatus was higher than B. xylophilus. Stenotrophomonas, Pseudomonadaceae_Unclassified or Rhizobiaceae_Unclassified were predominant in the nematode strains with different virulence. Oxalobacteraceae and Achromobacter were found more abundant in the low virulent B. xylophilus and non-virulent B. mucronatus strains. PMID:26372013

  19. Agroforestry leads to shifts within the gammaproteobacterial microbiome of banana plants cultivated in Central America

    PubMed Central

    Köberl, Martina; Dita, Miguel; Martinuz, Alfonso; Staver, Charles; Berg, Gabriele

    2015-01-01

    Bananas (Musa spp.) belong to the most important global food commodities, and their cultivation represents the world's largest monoculture. Although the plant-associated microbiome has substantial influence on plant growth and health, there is a lack of knowledge of the banana microbiome and its influencing factors. We studied the impact of (i) biogeography, and (ii) agroforestry on the banana-associated gammaproteobacterial microbiome analyzing plants grown in smallholder farms in Nicaragua and Costa Rica. Profiles of 16S rRNA genes revealed high abundances of Pseudomonadales, Enterobacteriales, Xanthomonadales, and Legionellales. An extraordinary high diversity of the gammaproteobacterial microbiota was observed within the endophytic microenvironments (endorhiza and pseudostem), which was similar in both countries. Enterobacteria were identified as dominant group of above-ground plant parts (pseudostem and leaves). Neither biogeography nor agroforestry showed a statistically significant impact on the gammaproteobacterial banana microbiome in general. However, indicator species for each microenvironment and country, as well as for plants grown in Coffea intercropping systems with and without agri-silvicultural production of different Fabaceae trees (Inga spp. in Nicaragua and Erythrina poeppigiana in Costa Rica) could be identified. For example, banana plants grown in agroforestry systems were characterized by an increase of potential plant-beneficial bacteria, like Pseudomonas and Stenotrophomonas, and on the other side by a decrease of Erwinia. Hence, this study could show that as a result of legume-based agroforestry the indigenous banana-associated gammaproteobacterial community noticeably shifted. PMID:25717322

  20. Complex sputum microbial composition in patients with pulmonary tuberculosis

    PubMed Central

    2012-01-01

    Background An increasing number of studies have implicated the microbiome in certain diseases, especially chronic diseases. In this study, the bacterial communities in the sputum of pulmonary tuberculosis patients were explored. Total DNA was extracted from sputum samples from 31 pulmonary tuberculosis patients and respiratory secretions of 24 healthy participants. The 16S rRNA V3 hyper-variable regions were amplified using bar-coded primers and pyro-sequenced using Roche 454 FLX. Results The results showed that the microbiota in the sputum of pulmonary tuberculosis patients were more diverse than those of healthy participants (p<0.05). The sequences were classified into 24 phyla, all of which were found in pulmonary tuberculosis patients and 17 of which were found in healthy participants. Furthermore, many foreign bacteria, such as Stenotrophomonas, Cupriavidus, Pseudomonas, Thermus, Sphingomonas, Methylobacterium, Diaphorobacter, Comamonas, and Mobilicoccus, were unique to pulmonary tuberculosis patients. Conclusions This study concluded that the microbial composition of the respiratory tract of pulmonary tuberculosis patients is more complicated than that of healthy participants, and many foreign bacteria were found in the sputum of pulmonary tuberculosis patients. The roles of these foreign bacteria in the onset or development of pulmonary tuberculosis shoud be considered by clinicians. PMID:23176186

  1. 60Co irradiation for sterilization of veterinary mastitis products containing antibiotics and steroids

    NASA Astrophysics Data System (ADS)

    Tsuji, K.; Kane, M. P.; Rahn, P. D.; Steindler, K. A.

    Effects of 60Co irradiation for sterilization of veterinary mastitis products were evaluated. The mastitis products which were examined contained various combinations of antibiotics and steroids suspended in peanut oil vehicle. Bioburden data indicated that the unirradiated products were only occasionally contaminated with microorganisms. The D-values of the nonsterile product and environmental isolates were 0.028, 0.15, 0.017, and 0.018 Mrads for Aspergillus fumigatus, Penicillium oxalicum, Pseudomonas aeruginosa, and Pseudomonas maltophilia, respectively. The D-value of the biological indicator organism, Bacillus pumilus spores, in the vehicle was 0.27 Mrads. Thus, an irradiation dose of 1.6 Mrads would be sufficient to achieve six log cycles of destruction of the biological indicator organism. The minimum absorbed irradiation dose of 2.5 Mrads preferred by many countries for sterilization would achieve 9.3 log cycle destruction of the indicator organism and guarantee a probability of 1 × 10 -15 assurance for the most radio-resistant product isolate, Penicillium oxalicum. In order to examine short and long term chemical stabilities of active components, stability indicating high-performance liquid chromatographic (HPLC) methods for the determination of the following antibiotics and steroids were developed. They were: dihydrostreptomycin, neomycin, novobiocin, penicillin G, hydrocortisone acetate, hydrocortisone sodium succinate, and prednisolone. The rates of degradation and radiolytic degradation schemes for the majority of these compounds were elucidated. Formation of new compounds was not observed in these antibiotics and steroids upon 60Co irradiation. The compounds that increased by irradiation were inherently present in commercially available non-irradiated lots and/or can easily be formed by either acidic, basic, or thermal treatment.

  2. Chryseobacterium profundimaris sp. nov., a new member of the family Flavobacteriaceae isolated from deep-sea sediment.

    PubMed

    Xu, Lin; Huo, Ying-Yi; Li, Zheng-Yang; Wang, Chun-Sheng; Oren, Aharon; Xu, Xue-Wei

    2015-04-01

    A Gram-stain negative, strictly aerobic, rod-shaped, non-motile bacterium, designated strain DY46(T), was isolated from Atlantic Ocean sediment. The isolate was found to grow in medium containing 0-3.0 % (w/v) NaCl (optimally at 0-1.0 %), at 4-37 °C and pH 5.0-8.0. Chemotaxonomic analysis detected MK-6 as the sole isoprenoid quinone. The major fatty acids were identified iso-C15:0, iso-C17:0 3-OH, iso-C17:1 ?9c and summed feature 3 (comprising iso-C15:0 2-OH and/or C16:1 ?7c). The DNA G + C content was determined to be 40.7 mol %. Phylogenetic analyses based on the 16S rRNA gene sequence indicated that strain DY46(T) falls within the cluster comprising Chryseobacterium species. The levels of 16S rRNA gene sequence similarity between strain DY46(T) and the type strains of the Chryseobacterium species with validly published names ranged from 92.4 to 99.1 %, the high values (>97 %) being with Chryseobacterium takakiae A1-2(T) (99.1 %), C. taiwanense BCRC 17412(T) (98.0 %), C. taeanense PHA3-4(T) (97.3 %), C. hispalense DSM 25574(T) (97.3 %), C. camelliae THG C4-1(T) (97.2 %), C. gregarium DSM 19109(T) (97.1 %) and C. wanjuense R2A10-2(T) (97.0 %). The DNA-DNA relatedness values between strain DY46(T) and the type strains of the above closely related species were 47, 57, 24, 34, 6, 40 and 21 %, respectively. On the basis of phenotypic and genotypic characteristics, strain DY46(T) represents a novel member within the genus Chryseobacterium, for which the name Chryseobacterium profundimaris is proposed. The type strain is DY46(T) (=CGMCC 1.12663(T) = JCM 19801(T)). PMID:25616910

  3. Glycocaulis albus sp. nov., a moderately halophilic dimorphic prosthecate bacterium isolated from petroleum-contaminated saline soil.

    PubMed

    Lv, Xiang-Lin; Xie, Bai-Sheng; Cai, Man; Geng, Shuang; Tang, Yue-Qin; Wang, Ya-Nan; Cui, Heng-Lin; Liu, Xue-Ying; Ye, Si-Yuan; Wu, Xiao-Lei

    2014-09-01

    Two novel bacterial strains, SLG210-30A1(T) and SLG210-19A2, which shared 99.9?% 16S rRNA gene sequence similarity with each other, were isolated from petroleum-contaminated saline soil in Shengli Oilfield, eastern China. Cells were Gram-stain-negative, motile, aerobic, mesophilic and moderately halophilic. They could grow chemoheterotrophically with oxygen as an electron acceptor. Morphologically, cells were typical Caulobacteria-type dimorphic prosthecate bacteria. The genomic DNA G+C contents of strains SLG210-30A1(T) and SLG210-19A2 were 61.8 mol% and 61.6 mol% respectively. Strain SLG210-30A1(T) had Q10 as the predominant respiratory ubiquinone, and C16?:?0 (28.4?%), C17?:?0 (11.6?%), C18?:?0 (22.1?%) and C18?:?1?7c (14.0?%) as the major cellular fatty acids. The polar lipids of the two isolates were some glycolipids, a lipid, a phospholipid, an aminoglycolipid and an aminophospholipid (all unidentified). The 16S rRNA gene sequences of strains SLG210-30A1(T) and SLG210-19A2 showed the highest similarities with Glycocaulis abyssi MCS 33(T) (99.8-99.9?%), but low sequence similarities (<94.7?%) with type strains of other members of the family Hyphomonadaceae. However, the DNA-DNA relatedness of G. abyssi MCS 33(T) to strains SLG210-30A1(T) and SLG210-19A2 was 37.4±4.4?% and 36.1±1.1?%, respectively. Based on different physiological, biochemical, and phylogenetic characteristics, strains SLG210-30A1(T) and SLG210-19A2 represent a novel species of the genus Glycocaulis. The name Glycocaulis albus is therefore proposed with strain SLG210-30A1(T) (?=?LMG 27741(T)?=?CGMCC 1.12766(T)) as the type strain. An emended description of the genus Glycocaulis is also provided. PMID:24966201

  4. Blastomonas aquatica sp. nov., a bacteriochlorophyll-containing bacterium isolated from lake water.

    PubMed

    Xiao, Na; Liu, Yongqin; Liu, Xiaobo; Gu, Zhengquan; Jiao, Nianzhi; Liu, Hongcan; Zhou, Yuguang; Shen, Liang

    2015-05-01

    Yellow or orange-to-brown pigmented, ovoid or rod-shaped, Gram-negative staining, aerobic strains PE 4-5(T) and N5-10 m-1 were isolated from brackish water in Lake Peng Co and fresh to brackish water in Lake Namtso on the Tibetan Plateau, China. Bacteriochlorophyll a was produced by the isolates. The predominant cellular fatty acids were C16 : 1, C17 : 1 and C18 : 1 unsaturated fatty acids, C17 : 1?6c (55.3%), C17 : 1?8c (13.0%) and C18 : 1?7c (10.4%) for PE 4-5(T) and C18 : 1?7c (54.7%) and C16 : 1?7c (18.0%) for N5-10 m-1. The polar lipid profiles of strains PE 4-5(T) and N5-10 m-1 were composed of diphosphatidylglycerol, phosphatidylcholine (not detected in N5-10 m-1), phosphatidyldimethylethanolamine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, sphingoglycolipid and an unknown phospholipid. The predominant respiratory quinone was ubiquinone Q10 and the DNA G+C content was 66.0 mol% for both strains. The16S rRNA gene sequence of strain PE 4-5(T) shared 99.0% similarity with that of N5-10 m-1, and 97.56% similarity with those of Blastomonas natatoria LMG 17322(T) and Blastomonas ursincola DSM 9006(T), respectively. The DNA-DNA hybridization relatedness between strains PE 4-5(T) and N5-10 m-1 was 79.0 ± 1.0%, but below 70% with the type strains in the genus Blastomonas . Based on the variability of phylogenetic and phenotypic characteristics, the isolates should be classified as representatives of a novel species of the genus Blastomonas; the name Blastomonas aquatica sp. nov. is proposed. The type strain is PE 4-5(T) (?=JCM 30179(T)?=CGMCC 1.12851(T)). PMID:25724744

  5. Halobacillus andaensis sp. nov., a moderately halophilic bacterium isolated from saline and alkaline soil.

    PubMed

    Wang, Kaibiao; Zhang, Lei; Yang, Yang; Pan, Yuanyuan; Meng, Lin; Liu, Henan; Hong, Shan; Huang, Haipeng; Jiang, Juquan

    2015-06-01

    A Gram-stain-positive, endospore-forming, moderately halophilic bacterial strain, NEAU-ST10-40T, was isolated from a saline and alkaline soil in Anda City, China. It was strictly aerobic, rod-shaped and motile by peritrichous flagella. It formed light yellow colonies and grew at NaCl concentrations of 3-15 % (w/v) (optimum, 8 %, w/v), at pH 7.0-9.0 (optimum, pH 8.0) and at 4-60 °C (optimum, 30 °C). It contained meso-diaminopimelic acid in the cell-wall peptidoglycan. Phylogenetic analysis based on 16S rRNA gene sequences indicated that it belonged to the genus Halobacillus. Levels of 16S rRNA gene sequence similarity between strain NEAU-ST10-40T and the type strains of related species of the genus Halobacillus ranged from 98.8 % (Halobacillus alkaliphilus FP5T) to 97.1 % (Halobacillus kuroshimensis IS-Hb7T). DNA-DNA hybridization relatedness values between strain NEAU-ST10-40T and H. alkaliphilus DSM 18525T, Halobacillus campisalis KCTC 13144T, Halobacillus yeomjeoni DSM 17110T, Halobacillus halophilus DSM 2266T, Halobacillus litoralis DSM 10405T, Halobacillus dabanensis DSM 18199T, Halobacillus salinus DSM 18897T, Halobacillus naozhouensis DSM 21183T, Halobacillus trueperi DSM 10404T and Halobacillus salsuginis DSM 21185T were from 43 ± 1 to 19 ± 1 % (mean ± sd). The DNA G+C content was 39.3 mol%. The major fatty acids (>10 %) were anteiso-C15:0, anteiso-C17:0 and iso-C16:0, the only respiratory quinone detected was MK-7, and polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unknown phospholipids and three unknown lipids. On the basis of the data presented, strain NEAU-ST10-40T is considered to represent a novel species, for which the name Halobacillus andaensis sp. nov. is proposed. The type strain is NEAU-ST10-40T (?= CGMCC 1.12153T = DSM 25866T). PMID:25795064

  6. Thermoactinomyces guangxiensis sp. nov., a thermophilic actinomycete isolated from mushroom compost.

    PubMed

    Wu, Hao; Liu, Bin; Pan, Shangli

    2015-09-01

    A novel thermophilic actinomycete, designated strain CD-1T, was isolated from mushroom compost in Nanning, Guangxi province, China. The strain grew at 37-55?°C (optimum 45-50?°C), pH?6.0-11.0 (optimum pH?7.0-9.0) and with 0-2.0??% NaCl (optimum 0-1.0??%), formed well-developed white aerial mycelium and pale-yellow vegetative mycelium, and single endospores (0.8-1.0??m diameter) were borne on long sporophores (2-3??m length). The endospores were spherical-polyhedron in shape with smooth surface. Based on its phenotypic and phylogenetic characteristics, strain CD-1T is affiliated to the genus Thermoactinomyces. It contained meso-diaminopimelic acid as the diagnostic diamino acid; the whole-cell sugars were ribose and glucose. Major fatty acids were iso-C15??:??0, C16??:??0, anteiso-C15??:??0 and iso-C17??:??0. MK-7 was the predominant menaquinone. The polar phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylethanolamine containing hydroxylated fatty acids, ninhydrin-positive glycophospholipid, an unknown phospholipid and glycolipids. The G+C content of the genomic DNA was 48.8??%. 16S rRNA gene sequence analysis showed that the organism was closely related to Lihuaxuella thermophila YIM 77831T (95.69??% sequence similarity), Thermoactinomyces daqus H-18T (95.49??%), Laceyella putida KCTC 3666T (95.05??%), Thermoactinomyces vulgaris KCTC 9076T (95.01??%) and Thermoactinomyces intermedius JCM 3312T (94.55??%). Levels of DNA-DNA relatedness between strain CD-1T and Lihuaxuella thermophila JCM 18059T, Thermoactinomyces daqus DSM 45914T, Laceyella putida JCM 8091T, Thermoactinomyces vulgaris JCM 3162T and Thermoactinomyces intermedius JCM 3312T were low (22.8, 33.3, 24.7, 29.4 and 30.0??%, respectively). A battery of phenotypic, genotypic and DNA-DNA relatedness data indicated that strain CD-1T represented a novel species of the genus Thermoactinomyces, for which the name Thermoactinomyces guangxiensis sp. nov. is proposed. The type strain is CD-1T (?=?ATCC BAA-2630T?=?CGMCC 4.7156T). PMID:25991661

  7. Luteibacter jiangsuensis sp. nov.: a methamidophos-degrading bacterium isolated from a methamidophos-manufacturing factory.

    PubMed

    Wang, Li; Wang, Guang-li; Li, Shun-peng; Jiang, Jian-dong

    2011-01-01

    A Gram-stain-negative, non-motile, rod-shaped bacterial strain, JW-64-1(T), capable of degrading methamidophos was isolated from a methamidophos-manufacturing factory in China, and was subjected to a polyphasic taxonomic investigation. Strain JW-64-1(T) produced circular, smooth, transparent, yellow-colored colonies (1.0-2.0 mm) on LB agar after 2 days incubation. It grew optimally at 25-30°C and pH 7.0 without the presence of NaCl. The G+C content of the total DNA was 63.6 mol%. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain JW-64-1(T) fell within the cluster comprising Luteibacter species. The 16S rRNA gene sequence of strain JW-64-1(T) was most closely related to Luteibacter rhizovicinus DSM 16549(T) (98.6%), followed by Luteibacter yeojuensis DSM 17673(T) (98.4%) and L. anthropi CCUG 25036(T) (98.2%). The major cellular fatty acids of strain JW-64-1(T) were iso-C(15:0) (24.1%), iso-C(17:0) (20.2%) and summed feature 9 comprising iso-C(17:1) ?9c and/or C(16:0) 10-methyl (20.3%). The major isoprenoid quinine was Q-8 (98%), and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphoaminolipid, aminolipids-1, aminolipids-2, and phospholipids. The values for DNA-DNA relatedness between strain JW-64-1(T) and the closest phylogenetic relatives of L. rhizovicinus and Luteibacter yeojuensis were 34.8 ± 2.6 and 25.6 ± 3.1%, respectively. On the basis of the phenotypic, chemotaxonomic, DNA-DNA relatedness and phylogenetic analysis based on the 16S rRNA gene sequences, strain JW-64-1(T) represents a novel species of the genus Luteibacter, for which the name Luteibacter jiangsuensis sp. nov. is proposed. The type strain is JW-64-1(T) (=CGMCC 1.10133(T) = DSM 22396(T)). PMID:20628745

  8. Lysobacter hymeniacidonis sp. nov., isolated from a crude oil-contaminated marine sponge

    NASA Astrophysics Data System (ADS)

    Xin, Yanjuan; Qu, Junge; Xu, Junyi; Wu, Peichun; Cao, Xupeng; Xue, Song

    2015-09-01

    An aerobic, Gram-negative bacterium, strain 2-5T, was isolated from a crude oil-contaminated marine sponge collected near Dalian Bay, China, and subjected to a polyphasic taxonomic investigation. Cells of strain 2-5T were non-spore forming, non-motile, rods 0.2-0.3 µm wide and 1.1-1.2 µm long. Strain 2-5T grew well on nutrient agar, TSA, R2A agar and LB agar. Colonies of strain 2-5T on LB agar were circular, smooth with entire margins, non-transparent and pale yellow after 3 days of incubation at 30 ºC. Growth of strain 2-5T occurred in LN medium with 0-6% (w/v) NaCl; no growth occurred in the presence of 8.0% (w/v) NaCl. Strain 2-5T grew at 15-42ºC and at pH 6.0-8.0. Comparative 16S rRNA gene sequence analysis showed that strain 2-5T clustered with the species of the genus Lysobacter. Its closet neighbors were the type strains of Lysobacter concretionis KCTC 12205T (97% similarity), Lysobacter arseniciresistens ZS79T (96%), and Lysobacter defluii APB-9 T (96%). The value for DNA-DNA relatedness between strain 2-5T and L. concretionis KCTC 12205T was 23%. Branched fatty acids iso-C16: 0, iso-C15: 0, iso-C11: 0 3-OH, iso-C17: 1?9c and iso-C11: 0 were found to be predominant. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Strain 2-5T had a DNA G+C content of 63.8 mol%. On the basis of the phenotypic, chemotaxonomic, DNA-DNA hybridization and phylogenetic data, strain 2-5T represents a novel species of the genus Lysobacter, for which the name Lysobacter hymeniacidonis sp. nov. is proposed. The type strain is 2-5T (=CGMCC 1.12190T = JCM 18137T).

  9. Helicobacter himalayensis sp. nov. isolated from gastric mucosa of Marmota himalayana.

    PubMed

    Hu, Shoukui; Jin, Dong; Lu, Shan; Liu, Sha; Zhang, Ji; Wang, Yiting; Bai, Xiangning; Xiong, Yanwen; Huang, Ying; Xu, Huaqing; Wang, Yi; Du, Xiaoli; Ye, Changyun; Hänninen, Marja-Liisa; Xu, Jianguo

    2015-06-01

    A Gram-stain-negative, microaerophilic strain, 80(YS1)T, with a spiral-shaped morphology and 1-2 sheathed flagella at each end of the cells was isolated from the gastric mucosa of Marmota himalayana, the animal reservoir of Yersinia pestis in China, on the Qinghai-Tibet Plateau. The strain grew at 30, 35 and 42 °C, but not at 25 °C. Growth was in the form of a thinly spreading film on brain heart infusion agar containing 8 % sheep blood under microaerobic conditions. The strain did not hydrolyse urea or hippurate, and did not grow on media containing 1 % glycine. It reduced nitrate to nitrite, and was catalase- and alkaline-phosphatase-positive, susceptible to nalidixic acid and resistant to cefalotin. It was positive for genus-specific PCR for the genus Helicobacter, but could not be classified to any recognized species according biochemical tests results. Therefore, a phylogenetic study based on 16S rRNA, 23S rRNA, 60 kDa heat-shock protein (hsp60) and gyrase subunit B (gyrB) genes was conducted. The 16S rRNA gene sequence (1468 bp) analysis showed that strain 80(YS1)T was most closely related to Helicobacter marmotae (96.7 % similarity). The 23S rRNA gene sequence (2879 bp) analysis showed that the strain was most closely related to Helicobacter canis (96 % similarity). The complete gyrB gene sequence (2325 bp) analysis showed that it was related phylogenetically to Helicobacter cinaedi (79.4 % similarity) and H. marmotae (79.1 % similarity). Analysis of the partial sequence of the hsp60 gene of strain 80(YS1)T showed closest similarity to the sequences of Helicobacter equorum (82 %) and H. cinaedi (81 %), respectively. However, there was no hsp60 sequence of H. marmotae available for analysis. The data of morphological, biochemical and phylogenetic characteristics all supported that this strain represents a novel species. The name Helicobacter himalayensis sp. nov. is proposed for this novel species with the type strain 80(YS1)T (?= CGMCC 1.12864T = DSM 28742T). PMID:25736414

  10. Idiomarina planktonica sp. nov., isolated from a saline lake.

    PubMed

    Zhong, Zhi-Ping; Liu, Ying; Liu, Hong-Can; Wang, Fang; Song, Lei; Liu, Zhi-Pei

    2014-10-01

    A Gram-stain-negative bacterium, strain TS-T11(T), was isolated from Tuosu lake, a saline lake (salinity 5.4%, w/v) in the Qaidam basin, Qinghai province, China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain TS-T11(T) were non-spore-forming rods, 0.6-0.8 µm wide and 0.8-2.2 µm long, and motile by means of a single polar flagellum. Strain TS-T11(T) was strictly heterotrophic and aerobic. Cells were positive for catalase and oxidase. Growth was observed in the presence of 0.5-11.0% (w/v) NaCl (optimum 4.0-6.0%), at 4-40 °C (optimum 30-35 °C) and at pH 6.0-10.5 (optimum pH 7.5-8.5). Strain TS-T11(T) contained iso-C15:0, iso-C17:0 and iso-C17:1?9c as the predominant fatty acids (>10%). The major respiratory quinone was Q-8. The polar lipids consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and nine uncharacterized phospholipids. The G+C content of genomic DNA was 46.8 mol% (Tm). Phylogenetic trees based on 16S rRNA gene sequences showed that strain TS-T11(T) was associated with the genus Idiomarina, and showed highest 16S rRNA gene sequence similarity to Idiomarina aestuarii KYW314(T) (97.4%) and Idiomarina salinarum ISL-52(T) (97.4%). DNA-DNA relatedness of strain TS-T11(T) to I. aestuarii JCM 16344(T) and I. salinarum DSM 21900(T) was 22.2 ± 2.4 and 11.5 ± 1.6%, respectively. Based on the data presented above, it was concluded that strain TS-T11(T) represents a novel species of the genus Idiomarina, for which the name Idiomarina planktonica sp. nov. is proposed. The type strain is TS-T11(T) ( = CGMCC 1.12458(T) = JCM 19263(T)). PMID:25015677

  11. Roseibium aquae sp. nov., isolated from a saline lake.

    PubMed

    Zhong, Zhi-Ping; Liu, Ying; Liu, Hong-Can; Wang, Fang; Zhou, Yu-Guang; Liu, Zhi-Pei

    2014-08-01

    A Gram-staining-negative bacterium, strain DSG-S4-2(T), was isolated from Dasugan Lake, a saline lake (salinity 3.1%, w/v) in Qaidam basin, Qinghai, China and its taxonomic position was determined by using a polyphasic approach. Cells of strain DSG-S4-2(T) were non-spore-forming rods, 0.5-0.8 µm wide and 1.2-3.8 µm long and motile by means of a single polar flagellum. Strain DSG-S4-2(T) was strictly heterotrophic and aerobic, catalase-positive and oxidase-negative. PufLM and coxL genes were present, bacteriochlorophyll a (BChl a) and a carotenoid pigment were produced. Growth was observed in the presence of 0-8.0% (w/v) NaCl (optimum, 1.0-2.0%), at 20-40 °C (optimum, 35 °C) and pH 6.5-10.5 (optimum, pH 7.5-8.0). Strain DSG-S4-2(T) contained Q-10 as the sole respiratory quinone. The polar lipids contained two aminolipids, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, sulphoquinovosyldiacylglyceride, phosphatidylcholine and some unknown phospholipids, like the other members of the genus Roseibium. The predominant fatty acid (>70%) was summed feature 8 (C(18?:?1)?7c and/or C(18?:?1)?6c). The DNA G+C content was 61.4 mol% (determined from melting temperature). Phylogenetic trees (neighbour-joining, maximum-likelihood and maximum-parsimony) based on 16S rRNA gene sequences showed that strain DSG-S4-2(T) was associated with the members of the genus Roseibium, with highest 16S rRNA gene sequence similarity to Roseibium denhamense OCh 254(T) (96.3%) and Roseibium hamelinense OCh 368(T) (96.3%). Based on the data presented above, it is concluded that strain DSG-S4-2(T) represents a novel species of the genus Roseibium, for which the name Roseibium aquae sp. nov. is proposed. The type strain is DSG-S4-2(T) (?=?CGMCC 1.12426(T)?=?JCM 19310(T)). PMID:24867169

  12. Pseudomonas salina sp. nov., isolated from a salt lake.

    PubMed

    Zhong, Zhi-Ping; Liu, Ying; Hou, Ting-Ting; Liu, Hong-Can; Zhou, Yu-Guang; Wang, Fang; Liu, Zhi-Pei

    2015-09-01

    A Gram-staining-negative, facultatively aerobic bacterium, strain XCD-X85T, was isolated from Xiaochaidan Lake, a salt lake (salinity 9.9??%, w/v) in Qaidam basin, Qinghai province, China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain XCD-X85T were non-endospore-forming rods, 0.4-0.6??m wide and 1.0-1.6??m long, and motile by means of a single polar flagellum. Strain XCD-X85T was catalase- and oxidase-positive. Growth was observed in the presence of 0-12.0??% (w/v) NaCl (optimum, 1.0-2.0??%) and at 4-35?°C (optimum, 25-30?°C) and pH?6.5-10.5 (optimum, pH?8.0-8.5). Strain XCD-X85T contained (>10??%) summed feature 8 (C18?:?1?7c and/or C18?:?1?6c), C12?:?0, C16?:?0 and summed feature 3 (C16?:?1?7c and/or C16?:?1?6c) as the predominant fatty acids. The major respiratory quinone was ubiquinone 9 (Q-9). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was 57.4?mol%. Phylogenetic trees based on 16S rRNA gene sequences showed that strain XCD-X85T was associated with the genus Pseudomonas, and showed highest 16S rRNA gene sequence similarities to Pseudomonas pelagia CL-AP6T (99.0??%) and Pseudomonas bauzanensis BZ93T (96.8??%). DNA-DNA relatedness of strain XCD-X85T to P. pelagia JCM 15562T was 19?±?1??%. On the basis of the data presented above, it is concluded that strain XCD-X85T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas salina sp. nov. is proposed. The type strain is XCD-X85T (?=?CGMCC 1.12482T?=?JCM 19469T). PMID:25985833

  13. Thermococcus eurythermalis sp. nov., a conditional piezophilic, hyperthermophilic archaeon with a wide temperature range for growth, isolated from an oil-immersed chimney in the Guaymas Basin.

    PubMed

    Zhao, Weishu; Zeng, Xianping; Xiao, Xiang

    2015-01-01

    A conditional piezophilic, hyperthermophilic archaeon showing growth over a wide range of temperature, pH and pressure was isolated from an oil-immersed hydrothermal chimney at a depth of 2006.9 m in the Guaymas Basin. Enrichment and isolation of strain A501(T) were performed at 80 °C at 0.1 MPa. Cells of isolate A501(T) were irregular motile cocci with a polar tuft of flagella and generally 0.6-2.6 µm in diameter. Growth was detected over the range 50-100 °C (optimal growth at 85 °C) at atmospheric pressure and was observed at 102 °C at a pressure of 10 MPa. At 85 °C, growth was observed at a pressure of 0.1-70 MPa (optimum pressure 0.1 MPa-30 MPa), while at 95 °C, the pressure allowing growth ranged from 0.1 MPa to 50 MPa (optimum pressure 10 MPa). Cells of strain A501(T) grew at pH 4-9 (optimum pH 7.0) and a NaCl concentration of 1.0-5.0?% (w/v) (optimum concentration 2.5?% NaCl). This isolate was an anaerobic chemo-organoheterotroph and was able to utilize yeast extract, peptone, tryptone and starch as the single carbon source for growth. Elemental sulfur and cysteine stimulated growth; however, these molecules were not necessary. The DNA G+C content of the complete genome was 53.47 mol%. The results of 16S rRNA gene sequence analysis indicated that strain A501(T) belongs to the genus Thermococcus. There was no significant similarity between strain A501(T) and the phylogenetically related species of the genus Thermococcus based on complete genome sequence alignments and calculation of the average nucleotide identity and the tetranucleotide signature frequency correlation coefficient. These results indicate that strain A501(T) represents a novel species, Thermococcus eurythermalis sp. nov. The type strain is A501(T) (?=?CGMCC 7834(T)?=?JCM 30233(T)). PMID:25288278

  14. Lactivibrio alcoholicus gen. nov., sp. nov., an anaerobic, mesophilic, lactate-, alcohol-, carbohydrate- and amino-acid-degrading bacterium in the phylum Synergistetes.

    PubMed

    Qiu, Yan-Ling; Hanada, Satoshi; Kamagata, Yoichi; Guo, Rong-Bo; Sekiguchi, Yuji

    2014-06-01

    A mesophilic, obligately anaerobic, lactate-, alcohol-, carbohydrate- and amino-acid- degrading bacterium, designated strain 7WAY-8-7(T), was isolated from an upflow anaerobic sludge blanket reactor treating high-strength organic wastewater from isomerized sugar production processes. Cells of strain 7WAY-8-7(T) were motile, curved rods (0.7-1.0×5.0-8.0 µm). Spore formation was not observed. The strain grew optimally at 37 °C (range for growth was 25-40 °C) and pH 7.0 (pH 6.0-7.5), and could grow fermentatively on yeast extract, glucose, ribose, xylose, malate, tryptone, pyruvate, fumarate, Casamino acids, serine and cysteine. The main end-products of glucose fermentation were acetate and hydrogen. In co-culture with the hydrogenotrophic methanogen Methanospirillum hungatei DSM 864(T), strain 7WAY-8-7(T) could utilize lactate, glycerol, ethanol, 1-propanol, 1-butanol, L-glutamate, alanine, leucine, isoleucine, valine, histidine, asparagine, glutamine, arginine, lysine, threonine, 2-oxoglutarate, aspartate and methionine. A Stickland reaction was not observed with some pairs of amino acids. Yeast extract was required for growth. Nitrate, sulfate, thiosulfate, elemental sulfur, sulfite and Fe (III) were not used as terminal electron acceptors. The G+C content of the genomic DNA was 61.4 mol%. 16S rRNA gene sequence analysis revealed that the isolate belongs to the uncultured environmental clone clade (called 'PD-UASB-13' in the Greengenes database) in the bacterial phylum Synergistetes, showing less than 90% sequence similarity with closely related described species such as Aminivibrio pyruvatiphilus and Aminobacterium colombiense (89.7% and 88.7%, respectively). The major cellular fatty acids were iso-C(13?:?0), iso-C(15?:?0), anteiso-C(15?:?0), C(18?:?1), C(19?:?1), C(20?:?1) and C(21?:?1). A novel genus and species, Lactivibrio alcoholicus gen. nov., sp. nov. is proposed to accommodate strain 7WAY-8-7(T) (?=?JCM 17151(T)?=?DSM 24196(T)?=?CGMCC 1.5159(T)). PMID:24676730

  15. Lysobacter hymeniacidonis sp. nov., isolated from a crude oil-contaminated marine sponge

    NASA Astrophysics Data System (ADS)

    Xin, Yanjuan; Qu, Junge; Xu, Junyi; Wu, Peichun; Cao, Xupeng; Xue, Song

    2015-12-01

    An aerobic, Gram-negative bacterium, strain 2-5T, was isolated from a crude oil-contaminated marine sponge collected near Dalian Bay, China, and subjected to a polyphasic taxonomic investigation. Cells of strain 2-5T were non-spore forming, non-motile, rods 0.2-0.3 µm wide and 1.1-1.2µm long. Strain 2-5T grew well on nutrient agar, TSA, R2A agar and LB agar. Colonies of strain 2-5T on LB agar were circular, smooth with entire margins, non-transparent and pale yellow after 3 d of incubation at 30°C. Growth of strain 2-5T occurred in LN medium with 0-6% NaCl; no growth occurred in the presence of 8.0% NaCl. Strain 2-5T grew at 15-42°C and at pH 6.0-8.0. Comparative 16S rRNA gene sequence analysis showed that strain 2-5T clustered with the species of the genus Lysobacter. Its closet neighbors were the type strains of Lysobacter concretionis KCTC 12205T (97% similarity), Lysobacter arseniciresistens ZS79T (96%), and Lysobacter defluii APB-9T (96%). The value for DNA-DNA relatedness between strain 2-5T and L. concretionis KCTC 12205T was 23%. Branched fatty acids iso-C16: 0, iso-C15: 0, iso-C 11: 0 3-OH, iso-C17: 1?9 c and iso-C11: 0 were found to be predominant. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Strain 2-5T had a DNA G+C content of 63.8 mol%. On the basis of the phenotypic, chemotaxonomic, DNA-DNA hybridization and phylogenetic data, strain 2-5T represents a novel species of the genus Lysobacter, for which the name Lysobacter hymeniacidonis sp. nov. is proposed. The type strain is 2-5T (=CGMCC 1.12190T = JCM 18137T).

  16. A novel assay for the detection of bioactive volatiles evaluated by screening of lichen-associated bacteria

    PubMed Central

    Cernava, Tomislav; Aschenbrenner, Ines A.; Grube, Martin; Liebminger, Stefan; Berg, Gabriele

    2015-01-01

    Volatile organic compounds (VOCs) produced by microorganisms are known both for their effect on pathogens and their role as mediators in various interactions and communications. Previous studies have demonstrated the importance of VOCs for ecosystem functioning as well as their biotechnological potential, but screening for bioactive volatiles remained difficult. We have developed an efficient testing assay that is based on two multi-well plates, separated by a sealing silicone membrane, two tightening clamps, and variable growth media, or indicators. The experiment design as presented here is a novel and robust technique to identify positive as well as negative VOC effects on the growth of a target organism and to test for specific substances e.g., hydrogen cyanide which can be detected with a suitable indicator. While the first pre-screening assay is primarily based on indicator color change and visible growth diameter reduction, we also introduce an advanced and quantitatively precise experiment design. This adaptation involves qPCR-based quantification of viable target cells after concluding the treatment with VOCs. Therefore, we chose preselected active isolates and compared the partial 16S rRNA gene copy number of headspace-exposed E. coli with non-treated controls. Separately obtained headspace SPME and GC/MS-based profiles of selected bacterial isolates revealed the presence of specific and unique signatures which suggests divergent modes of action. The assay was evaluated by screening 100 isolates of lung lichen-associated bacteria. Approximately one quarter of the isolates showed VOC-based antibacterial and/or antifungal activity; mainly Pseudomonas and Stenotrophomonas species were identified as producers of bioactive volatiles. PMID:25983730

  17. Chestnut green waste composting for sustainable forest management: Microbiota dynamics and impact on plant disease control.

    PubMed

    Ventorino, Valeria; Parillo, Rita; Testa, Antonino; Viscardi, Sharon; Espresso, Francesco; Pepe, Olimpia

    2016-01-15

    Making compost from chestnut lignocellulosic waste is a possible sustainable management strategy for forests that employs a high-quality renewable organic resource. Characterization of the microbiota involved in composting is essential to better understand the entire process as well as the properties of the final product. Therefore, this study investigated the microbial communities involved in the composting of chestnut residues obtained from tree cleaning and pruning. The culture-independent approach taken highlighted the fact that the microbiota varied only slightly during the process, with the exception of those of the starting substrate and mature compost. The statistical analysis indicated that most of the bacterial and fungal species in the chestnut compost persisted during composting. The dominant microbial population detected during the process belonged to genera known to degrade recalcitrant lignocellulosic materials. Specifically, we identified fungal genera, such as Penicillium, Fusarium, Cladosporium, Aspergillus and Mucor, and prokaryotic species affiliated with Bacilli, Actinobacteria, Flavobacteria and ?-Proteobacteria. The suppressive properties of compost supplements for the biocontrol of Sclerotinia minor and Rhizoctonia solani were also investigated. Compared to pure substrate, the addition of compost to the peat-based growth substrates resulted in a significant reduction of disease in tomato plants of up to 70 % or 51 % in the presence of Sclerotinia minor or Rhizoctonia solani, respectively. The obtained results were related to the presence of putative bio-control agents and plant growth-promoting rhizobacteria belonging to the genera Azotobacter, Pseudomonas, Stenotrophomonas, Bacillus, Flavobacterium, Streptomyces and Actinomyces in the chestnut compost. The composting of chestnut waste may represent a sustainable agricultural practice for disposing of lignocellulosic waste by transforming it into green waste compost that can be used to improve the fitness of agricultural plants. PMID:26496847

  18. Biodegradation of 2,4,6-trichlorophenol in a packed-bed biofilm reactor equipped with an internal net draft tube riser for aeration and liquid circulation.

    PubMed

    Jesús, A Gómez-De; Romano-Baez, F J; Leyva-Amezcua, L; Juárez-Ramírez, C; Ruiz-Ordaz, N; Galíndez-Mayer, J

    2009-01-30

    For the aerobic biodegradation of the fungicide and defoliant 2,4,6-trichlorophenol (2,4,6-TCP), a bench-scale packed-bed bioreactor equipped with a net draft tube riser for liquid circulation and oxygenation (PB-ALR) was constructed. To obtain a high packed-bed volume relative to the whole bioreactor volume, a high A(D)/A(R) ratio was used. Reactor's downcomer was packed with a porous support of volcanic stone fragments. PB-ALR hydrodynamics and oxygen mass transfer behavior was evaluated and compared to the observed behavior of the unpacked reactor operating as an internal airlift reactor (ALR). Overall gas holdup values epsilon(G), and zonal oxygen mass transfer coefficients determined at various airflow rates in the PB-ALR, were higher than those obtained with the ALR. When comparing mixing time values obtained in both cases, a slight increment in mixing time was observed when reactor was operated as a PB-ALR. By using a mixed microbial community, the biofilm reactor was used to evaluate the aerobic biodegradation of 2,4,6-TCP. Three bacterial strains identified as Burkholderia sp., Burkholderia kururiensis and Stenotrophomonas sp. constituted the microbial consortium able to cometabolically degrade the 2,4,6-TCP, using phenol as primary substrate. This consortium removed 100% of phenol and near 99% of 2,4,6-TCP. Mineralization and dehalogenation of 2,4,6-TCP was evidenced by high COD removal efficiencies ( approximately 95%), and by the stoichiometric release of chloride ions from the halogenated compound ( approximately 80%). Finally, it was observed that the microbial consortium was also capable to metabolize 2,4,6-TCP without phenol as primary substrate, with high removal efficiencies (near 100% for 2,4,6-TCP, 92% for COD and 88% for chloride ions). PMID:18539387

  19. Selective pressure of antibiotics on ARGs and bacterial communities in manure-polluted freshwater-sediment microcosms

    PubMed Central

    Xiong, Wenguang; Sun, Yongxue; Ding, Xueyao; Wang, Mianzhi; Zeng, Zhenling

    2015-01-01

    The aim of this study was to investigate selective pressure of antibiotics on antibiotic resistance genes (ARGs) and bacterial communities in manure-polluted aquatic environment. Three treatment groups were set up in freshwater-sediment microcosms: tetracyclines group, sulfonamides group and fluoroquinolones group. Sediment and water samples were collected on day 14 after treatment. Antibiotic concentrations, ARGs abundances and bacterial community composition were analyzed. Antibiotic concentrations were determined by ultra-performance liquid chromatography-electrospray tandem mass spectrometry. ARGs abundances were quantified by real time quantitative PCR. Bacterial community composition was analyzed based on amplicon sequencing. Of the three classes of antibiotics analyzed in the treatment groups, accumulation amounts were tetracyclines> fluoroquinolone> sulfonamides in the sediment samples, while they were sulfonamides> fluoroquinolone> tetracyclines in the water samples. In the treatment groups, the relative abundances of some tet resistance genes [tet(W) and tet(X)] and plasmid-mediated quinolone resistance (PMQR) genes [oqx(B) and aac(6?)-Ib] in sediment samples were significantly higher than those in the paired water samples. Tetracyclines significantly selected the bacterial classes including Gammaproteobacteria, Clostridia, and the genera including Salmonella, Escherichia/Shigella, Clostridium, Stenotrophomonas in sediment samples. The significant selection on bacterial communities posed by sulfonamides and fluoroquinolones was also observed. The results indicated that sediment may supply an ideal setting for maintenance and persistence of tet resistance genes [tet(W) and tet(X)] and PMQR genes [oqx(B) and aac(6?)-Ib] under antibiotic pollution. The results also highlighted that antibiotics significantly selected specific bacterial communities including the taxa associated with opportunistic pathogens. PMID:25814986

  20. Selection for biocontrol bacteria antagonistic toward Rosellinia necatrix by enrichment of competitive avocado root tip colonizers.

    PubMed

    Pliego, Clara; Cazorla, Francisco Manuel; González-Sánchez, María Angeles; Pérez-Jiménez, Rosa María; de Vicente, Antonio; Ramos, Cayo

    2007-06-01

    Biological control of soil-borne pathogens is frequently based on the application of antagonistic microorganisms selected solely for their ability to produce in vitro antifungal factors. The aim of this work was to select bacteria that efficiently colonize the roots of avocado plants and display antagonism towards Rosellinia necatrix, the causal agent of avocado white root rot. A high frequency of antagonistic strains (ten isolates, 24.4%) was obtained using a novel procedure based on the selection of competitive avocado root tip colonizers. Amplification and sequencing of the 16S rRNA gene, in combination with biochemical characterization, showed that eight and two of the selected isolates belonged to the genera Pseudomonas and Stenotrophomonas, respectively. Characterization of antifungal compounds produced by the antagonistic strains showed variable production of exoenzymes and HCN. Only one of these strains, Pseudomonas sp. AVO94, produced a compound that could be related to antifungal antibiotics. All of the ten selected strains showed twitching motility, a cell movement involved in competitive colonization of root tips. Production of N-acyl-homoserine lactones and indole-3-acetic acid was also reported for some of these isolates. Resistance to several bacterial antibiotics was tested, and three strains showing resistance to only one of them were selected for biocontrol assays. The three selected strains persisted in the rhizosphere of avocado plants at levels considered crucial for efficient biocontrol, 10(5)-10(6) colony forming units/g of root; two of them, Pseudomonas putida AVO102 and Pseudomonas pseudoalcaligenes AVO110, demonstrated significant protection of avocado plants against white root rot. PMID:17467245

  1. Manila clams from Hg polluted sediments of Marano and Grado lagoons (Italy) harbor detoxifying Hg resistant bacteria in soft tissues.

    PubMed

    Baldi, Franco; Gallo, Michele; Marchetto, Davide; Faleri, Claudia; Maida, Isabel; Fani, Renato

    2013-08-01

    A mechanism of mercury detoxification has been suggested by a previous study on Hg bioaccumulation in Manila clams (Ruditapes philippinarum) in the polluted Marano and Grado lagoons and in this study we demonstrate that this event could be partly related to the detoxifying activities of Hg-resistant bacteria (MRB) harbored in clam soft tissues. Therefore, natural clams were collected in six stations during two different periods (winter and spring) from Marano and Grado Lagoons. Siphons, gills and hepatopancreas from acclimatized clams were sterile dissected to isolate MRB. These anatomical parts were glass homogenized or used for whole, and they were lying on a solid medium containing 5mgl(-1) HgCl2 and incubated at 30°C. A total of fourteen bacterial strains were isolated and were identified by 16S rDNA sequencing and analysis, revealing that strains were representative of eight bacterial genera, four of which were Gram-positive (Enterococcus, Bacillus, Jeotgalicoccus and Staphylococcus) and other four were Gram-negative (Stenotrophomonas, Vibrio, Raoultella and Enterobacter). Plasmids and merA genes were found and their sequences determined. Fluorescence in situ hybridization (FISH) technique shows the presence of Firmicutes, Actinobacteria and Gammaproteobacteria by using different molecular probes in siphon and gills. Bacterial clumps inside clam flesh were observed and even a Gram-negative endosymbiont was disclosed by transmission electronic microscope inside clam cells. Bacteria harbored in cavities of soft tissue have mercury detoxifying activity. This feature was confirmed by the determination of mercuric reductase in glass-homogenized siphons and gills. PMID:23398778

  2. Antifungal Rhizosphere Bacteria Can increase as Response to the Presence of Saprotrophic Fungi

    PubMed Central

    de Boer, Wietse; Hundscheid, Maria P. J.; Klein Gunnewiek, Paulien J. A.; de Ridder-Duine, Annelies S.; Thion, Cecile; van Veen, Johannes A.; van der Wal, Annemieke

    2015-01-01

    Knowledge on the factors that determine the composition of bacterial communities in the vicinity of roots (rhizosphere) is essential to understand plant-soil interactions. Plant species identity, plant growth stage and soil properties have been indicated as major determinants of rhizosphere bacterial community composition. Here we show that the presence of saprotrophic fungi can be an additional factor steering rhizosphere bacterial community composition and functioning. We studied the impact of presence of two common fungal rhizosphere inhabitants (Mucor hiemalis and Trichoderma harzianum) on the composition of cultivable bacterial communities developing in the rhizosphere of Carex arenaria (sand sedge) in sand microcosms. Identification and phenotypic characterization of bacterial isolates revealed clear shifts in the rhizosphere bacterial community composition by the presence of two fungal strains (M. hiemalis BHB1 and T. harzianum PvdG2), whereas another M. hiemalis strain did not show this effect. Presence of both M. hiemalis BHB1 and T. harzianum PvdG2 resulted in a significant increase of chitinolytic and (in vitro) antifungal bacteria. The latter was most pronounced for M. hiemalis BHB1, an isolate from Carex roots, which stimulated the development of the bacterial genera Achromobacter and Stenotrophomonas. In vitro tests showed that these genera were strongly antagonistic against M. hiemalis but also against the plant-pathogenic fungus Rhizoctonia solani. The most likely explanation for fungal-induced shifts in the composition of rhizosphere bacteria is that bacteria are being selected which are successful in competing with fungi for root exudates. Based on the results we propose that measures increasing saprotrophic fungi in agricultural soils should be explored as an alternative approach to enhance natural biocontrol against soil-borne plant-pathogenic fungi, namely by stimulating indigenous antifungal rhizosphere bacteria. PMID:26393509

  3. Hydrocarbonoclastic bacteria isolated from petroleum contaminated sites in Tunisia: isolation, identification and characterization of the biotechnological potential.

    PubMed

    Mahjoubi, Mouna; Jaouani, Atef; Guesmi, Amel; Ben Amor, Sonia; Jouini, Ahlem; Cherif, Hanen; Najjari, Afef; Boudabous, Abdellatif; Koubaa, Nedra; Cherif, Ameur

    2013-09-25

    Petroleum hydrocarbons are important energy resources used by industry and in our daily life, whose production contributes highly to environmental pollution. To control such risk, bioremediation constitutes an environmentally friendly alternative technology that has been established and applied. It constitutes the primary mechanism for the elimination of hydrocarbons from contaminated sites by natural existing populations of microorganisms. In this work, a collection of 125 strains, adapted to grow on minimal medium supplemented with crude oil, was obtained from contaminated sediments and seawater from a refinery harbor of the Bizerte coast in the North of Tunisia. The diversity of the bacterial collection was analyzed by amplification of the internal transcribed spacers between the 16S and the 23S rRNA genes (ITS-PCR) and by 16S rRNA sequencing. A total of 36 distinct ITS haplotypes were detected on agarose matrix. Partial 16S rRNA gene sequencing performed on 50 isolates showed high level of identity with known sequences. Strains were affiliated to Ochrabactrum, Sphingobium, Acinetobacter, Gordonia, Microbacterium, Brevundimonas, Novosphingobium, Stenotrophomonas, Luteibacter, Rhodococcus, Agrobacterium, Achromobacter, Bacilllus, Kocuria and Pseudomonas genera. Acinetobacter and Stenotrophomons were found to be the most abundant species characterized by a marked microdiversity as shown through ITS typing. Culture-independent approach (DGGE) showed high diversity in the microbial community in all the studied samples with a clear correlation with the hydrocarbon pollution rate. Sequencing of the DGGE bands revealed a high proportion of Proteobacteria represented by the Alpha and Gamma subclasses. The predominant bacterial detected by both dependent and independent approaches were the Proteobacteria. The biotechnological potential of the isolates revealed a significant production of biosurfactants with important emulsification activities useful in bioremediation. The highest emulsification activity was detected in Pseudomonas geniculata with 52.77% of emulsification. Our overall results suggest that the obtained bacterial isolates may constitute potential candidates for bioremediation and can be useful for biotechnological applications. PMID:23541698

  4. Bioprospection and selection of bacteria isolated from environments contaminated with petrochemical residues for application in bioremediation.

    PubMed

    Cerqueira, Vanessa S; Hollenbach, Emanuel B; Maboni, Franciele; Camargo, Flávio A O; Peralba, Maria do Carmo R; Bento, Fátima M

    2012-03-01

    The use of microorganisms with hydrocarbon degrading capability and biosurfactant producers have emerged as an alternative for sustainable treatment of environmental passives. In this study 45 bacteria were isolated from samples contaminated with petrochemical residues, from which 21 were obtained from Landfarming soil contaminated with oily sludge, 11 were obtained from petrochemical industry effluents and 13 were originated directly from oily sludge. The metabolization capability of different carbon sources, growth capacity and tolerance, biosurfactant production and enzymes detection were determined. A preliminary selection carried out through the analysis of capability for degrading hydrocarbons showed that 22% of the isolates were able to degrade all carbon sources employed. On the other hand, in 36% of the isolates, the degradation of the oily sludge started within 18-48 h. Those isolates were considered as the most efficient ones. Twenty isolates, identified based on partial sequencing of the 16S rRNA gene, were pre-selected. These isolates showed ability for growing in a medium containing 1% of oily sludge as the sole carbon source, tolerance in a medium containing up to 30% of oily sludge, ability for biosurfactant production, and expression of enzymes involved in degradation of aliphatic and aromatic compounds. Five bacteria, identified as Stenotrophomonas acidaminiphila BB5, Bacillus megaterium BB6, Bacillus cibi, Pseudomonas aeruginosa, and Bacillus cereus BS20 were shown to be promising for use as inoculum in bioremediation processes (bioaugmentation) of areas contaminated with petrochemical residues since they can use oily sludge as the sole carbon source and produce biosurfactants. PMID:22805841

  5. Pseudomonads Rule Degradation of Polyaromatic Hydrocarbons in Aerated Sediment

    PubMed Central

    Wald, Jiri; Hroudova, Miluse; Jansa, Jan; Vrchotova, Blanka; Macek, Tomas; Uhlik, Ondrej

    2015-01-01

    Given that the degradation of aromatic pollutants in anaerobic environments such as sediment is generally very slow, aeration could be an efficient bioremediation option. Using stable isotope probing (SIP) coupled with pyrosequencing analysis of 16S rRNA genes, we identified naphthalene-utilizing populations in aerated polyaromatic hydrocarbon (PAH)-polluted sediment. The results showed that naphthalene was metabolized at both 10 and 20°C following oxygen delivery, with increased degradation at 20°C as compared to 10°C—a temperature more similar to that found in situ. Naphthalene-derived 13C was primarily assimilated by pseudomonads. Additionally, Stenotrophomonas, Acidovorax, Comamonas, and other minor taxa were determined to incorporate 13C throughout the measured time course. The majority of SIP-detected bacteria were also isolated in pure cultures, which facilitated more reliable identification of naphthalene-utilizing populations as well as proper differentiation between primary consumers and cross-feeders. The pseudomonads acquiring the majority of carbon were identified as Pseudomonas veronii and Pseudomonas gessardii. Stenotrophomonads and Acidovorax defluvii, however, were identified as cross-feeders unable to directly utilize naphthalene as a growth substrate. PAH degradation assays with the isolated bacteria revealed that all pseudomonads as well as Comamonas testosteroni degraded acenaphthene, fluorene, and phenanthrene in addition to naphthalene. Furthermore, P. veronii and C. testosteroni were capable of transforming anthracene, fluoranthene, and pyrene. Screening of isolates for naphthalene dioxygenase genes using a set of in-house designed primers for Gram-negative bacteria revealed the presence of such genes in pseudomonads and C. testosteroni. Overall, our results indicated an apparent dominance of pseudomonads in the sequestration of carbon from naphthalene and potential degradation of other PAHs upon aeration of the sediment at both 20 and 10°C. PMID:26635740

  6. Could petroleum biodegradation be a joint achievement of aerobic and anaerobic microrganisms in deep sea reservoirs?

    PubMed Central

    2011-01-01

    Several studies suggest that petroleum biodegradation can be achieved by either aerobic or anaerobic microorganisms, depending on oxygen input or other electron acceptors and appropriate nutrients. Evidence from in vitro experiments with samples of petroleum formation water and oils from Pampo Field indicate that petroleum biodegradation is more likely to be a joint achievement of both aerobic and anaerobic bacterial consortium, refining our previous observations of aerobic degradation. The aerobic consortium depleted, in decreasing order, hydrocarbons > hopanes > steranes > tricyclic terpanes while the anaerobic consortium depleted hydrocarbons > steranes > hopanes > tricyclic terpanes. The oxygen content of the mixed consortia was measured from time to time revealing alternating periods of microaerobicity (O2 ~0.8 mg.L-1) and of aerobicity (O2~6.0 mg.L-1). In this experiment, the petroleum biodegradation changed from time to time, alternating periods of biodegradation similar to the aerobic process and periods of biodegradation similar to the anaerobic process. The consortia showed preferences for metabolizing hydrocarbons > hopanes > steranes > tricyclic terpanes during a 90-day period, after which this trend changed and steranes were more biodegraded than hopanes. The analysis of aerobic oil degrading microbiota by the 16S rRNA gene clone library detected the presence of Bacillus, Brevibacterium, Mesorhizobium and Achromobacter, and the analysis of the anaerobic oil degrading microbiota using the same technique detected the presence of Bacillus and Acinetobacter (facultative strains). In the mixed consortia Stenotrophomonas, Brevibacterium, Bacillus, Rhizobium, Achromobacter and 5% uncultured bacteria were detected. This is certainly a new contribution to the study of reservoir biodegradation processes, combining two of the more important accepted hypotheses. PMID:22196374

  7. Dynamics of Soil Bacterial Communities in Response to Repeated Application of Manure Containing Sulfadiazine

    PubMed Central

    Ding, Guo-Chun; Radl, Viviane; Schloter-Hai, Brigitte; Jechalke, Sven; Heuer, Holger; Smalla, Kornelia; Schloter, Michael

    2014-01-01

    Large amounts of manure have been applied to arable soils as fertilizer worldwide. Manure is often contaminated with veterinary antibiotics which enter the soil together with antibiotic resistant bacteria. However, little information is available regarding the main responders of bacterial communities in soil affected by repeated inputs of antibiotics via manure. In this study, a microcosm experiment was performed with two concentrations of the antibiotic sulfadiazine (SDZ) which were applied together with manure at three different time points over a period of 133 days. Samples were taken 3 and 60 days after each manure application. The effects of SDZ on soil bacterial communities were explored by barcoded pyrosequencing of 16S rRNA gene fragments amplified from total community DNA. Samples with high concentration of SDZ were analyzed on day 193 only. Repeated inputs of SDZ, especially at a high concentration, caused pronounced changes in bacterial community compositions. By comparison with the initial soil, we could observe an increase of the disturbance and a decrease of the stability of soil bacterial communities as a result of SDZ manure application compared to the manure treatment without SDZ. The number of taxa significantly affected by the presence of SDZ increased with the times of manure application and was highest during the treatment with high SDZ-concentration. Numerous taxa, known to harbor also human pathogens, such as Devosia, Shinella, Stenotrophomonas, Clostridium, Peptostreptococcus, Leifsonia, Gemmatimonas, were enriched in the soil when SDZ was present while the abundance of bacteria which typically contribute to high soil quality belonging to the genera Pseudomonas and Lysobacter, Hydrogenophaga, and Adhaeribacter decreased in response to the repeated application of manure and SDZ. PMID:24671113

  8. Biocatalytic desulfurization of thiophenic compounds and crude oil by newly isolated bacteria

    PubMed Central

    Mohamed, Magdy El-Said; Al-Yacoub, Zakariya H.; Vedakumar, John V.

    2015-01-01

    Microorganisms possess enormous highly specific metabolic activities, which enable them to utilize and transform nearly every known chemical class present in crude oil. In this context, one of the most studied biocatalytic processes is the biodesulfurization (BDS) of thiophenic sulfur-containing compounds such as benzothiophene (BT) and dibenzothiophene (DBT) in crude oils and refinery streams. Three newly isolated bacterial strains, which were affiliated as Rhodococcus sp. strain SA11, Stenotrophomonas sp. strain SA21, and Rhodococcus sp. strain SA31, were enriched from oil contaminated soil in the presence of DBT as the sole S source. GC-FID analysis of DBT-grown cultures showed consumption of DBT, transient formation of DBT sulfone (DBTO2) and accumulation of 2-hydroxybiphenyl (2-HBP). Molecular detection of the plasmid-borne dsz operon, which codes for the DBT desulfurization activity, revealed the presence of dszA, dszB, and dszC genes. These results point to the operation of the known 4S pathway in the BDS of DBT. The maximum consumption rate of DBT was 11 ?mol/g dry cell weight (DCW)/h and the maximum formation rate of 2-HBP formation was 4 ?mol/g DCW/h. Inhibition of both cell growth and DBT consumption by 2-HBP was observed for all isolates but SA11 isolate was the least affected. The isolated biocatalysts desulfurized other model DBT alkylated homologs. SA11 isolate was capable of desulfurizing BT as well. Resting cells of SA11 exhibited 10% reduction in total sulfur present in heavy crude oil and 18% reduction in total sulfur present in the hexane-soluble fraction of the heavy crude oil. The capabilities of the isolated bacteria to survive and desulfurize a wide range of S compounds present in crude oil are desirable traits for the development of a robust BDS biocatalyst to upgrade crude oils and refinery streams. PMID:25762990

  9. Bacteria influence mountain pine beetle brood development through interactions with symbiotic and antagonistic fungi: implications for climate-driven host range expansion.

    PubMed

    Therrien, Janet; Mason, Charles J; Cale, Jonathan A; Adams, Aaron; Aukema, Brian H; Currie, Cameron R; Raffa, Kenneth F; Erbilgin, Nadir

    2015-10-01

    Bark beetles are associated with diverse communities of symbionts. Although fungi have received significant attention, we know little about how bacteria, and in particular their interactions with fungi, affect bark beetle reproduction. We tested how interactions between four bacterial associates, two symbiotic fungi, and two opportunistic fungi affect performance of mountain pine beetles (Dendroctonus ponderosae) in host tissue. We compared beetle performance in phloem of its historical host, lodgepole pine (Pinus contorta), and its novel host recently accessed through warming climate, jack pine (Pinus banksiana). Overall, beetles produced more larvae, and established longer ovipositional and larval galleries in host tissue predominantly colonized by the symbiotic fungi, Grosmannia clavigera, or Ophiostoma montium than by the opportunistic colonizer Aspergillus and to a lesser extent, Trichoderma. This occurred in both historical and naïve hosts. Impacts of bacteria on beetle reproduction depended on particular fungus-bacterium combinations and host species. Some bacteria, e.g., Pseudomonas sp. D4-22 and Hy4T4 in P. contorta and Pseudomonas sp. Hy4T4 and Stenotrophomonas in P. banksiana, reduced antagonistic effects by Aspergillus and Trichoderma resulting in more larvae and longer ovipositional and larval galleries. These effects were not selective, as bacteria also reduced beneficial effects by symbionts in both host species. Interestingly, Bacillus enhanced antagonistic effects by Aspergillus in both hosts. These results demonstrate that bacteria influence brood development of bark beetles in host tissue. They also suggest that climate-driven range expansion of D. ponderosae through the boreal forest will not be significantly constrained by requirements of, or interactions among, its microbial associates. PMID:26037523

  10. Manila clams from Hg polluted sediments of Marano and Grado lagoons (Italy) harbor detoxifying Hg resistant bacteria in soft tissues

    SciTech Connect

    Baldi, Franco; Gallo, Michele; Marchetto, Davide; Faleri, Claudia; Maida, Isabel; Fani, Renato

    2013-08-15

    A mechanism of mercury detoxification has been suggested by a previous study on Hg bioaccumulation in Manila clams (Ruditapes philippinarum) in the polluted Marano and Grado lagoons and in this study we demonstrate that this event could be partly related to the detoxifying activities of Hg-resistant bacteria (MRB) harbored in clam soft tissues. Therefore, natural clams were collected in six stations during two different periods (winter and spring) from Marano and Grado Lagoons. Siphons, gills and hepatopancreas from acclimatized clams were sterile dissected to isolate MRB. These anatomical parts were glass homogenized or used for whole, and they were lying on a solid medium containing 5 mg l{sup ?1} HgCl{sub 2} and incubated at 30 °C. A total of fourteen bacterial strains were isolated and were identified by 16S rDNA sequencing and analysis, revealing that strains were representative of eight bacterial genera, four of which were Gram-positive (Enterococcus, Bacillus, Jeotgalicoccus and Staphylococcus) and other four were Gram-negative (Stenotrophomonas, Vibrio, Raoultella and Enterobacter). Plasmids and merA genes were found and their sequences determined. Fluorescence in situ hybridization (FISH) technique shows the presence of Firmicutes, Actinobacteria and Gammaproteobacteria by using different molecular probes in siphon and gills. Bacterial clumps inside clam flesh were observed and even a Gram-negative endosymbiont was disclosed by transmission electronic microscope inside clam cells. Bacteria harbored in cavities of soft tissue have mercury detoxifying activity. This feature was confirmed by the determination of mercuric reductase in glass-homogenized siphons and gills. -- Highlights: ? We isolated Gram-positive and Gram-negative Hg resistant strains from soft tissues of Ruditapes philippinarum. ? We identify 14 mercury resistant strains by 16S rRNA gene sequences. ? Bacteria in siphon and gill tissues of clams were observed by TEM and identified with different FISH probes. ? Hg-reductase (MerA) activity in glass homogenized clam tissues was also determined.

  11. Dynamics of soil bacterial communities in response to repeated application of manure containing sulfadiazine.

    PubMed

    Ding, Guo-Chun; Radl, Viviane; Schloter-Hai, Brigitte; Jechalke, Sven; Heuer, Holger; Smalla, Kornelia; Schloter, Michael

    2014-01-01

    Large amounts of manure have been applied to arable soils as fertilizer worldwide. Manure is often contaminated with veterinary antibiotics which enter the soil together with antibiotic resistant bacteria. However, little information is available regarding the main responders of bacterial communities in soil affected by repeated inputs of antibiotics via manure. In this study, a microcosm experiment was performed with two concentrations of the antibiotic sulfadiazine (SDZ) which were applied together with manure at three different time points over a period of 133 days. Samples were taken 3 and 60 days after each manure application. The effects of SDZ on soil bacterial communities were explored by barcoded pyrosequencing of 16S rRNA gene fragments amplified from total community DNA. Samples with high concentration of SDZ were analyzed on day 193 only. Repeated inputs of SDZ, especially at a high concentration, caused pronounced changes in bacterial community compositions. By comparison with the initial soil, we could observe an increase of the disturbance and a decrease of the stability of soil bacterial communities as a result of SDZ manure application compared to the manure treatment without SDZ. The number of taxa significantly affected by the presence of SDZ increased with the times of manure application and was highest during the treatment with high SDZ-concentration. Numerous taxa, known to harbor also human pathogens, such as Devosia, Shinella, Stenotrophomonas, Clostridium, Peptostreptococcus, Leifsonia, Gemmatimonas, were enriched in the soil when SDZ was present while the abundance of bacteria which typically contribute to high soil quality belonging to the genera Pseudomonas and Lysobacter, Hydrogenophaga, and Adhaeribacter decreased in response to the repeated application of manure and SDZ. PMID:24671113

  12. Carbapenemase Producing Bacteria in the Food Supply Escaping Detection

    PubMed Central

    Morrison, Beverly J.; Rubin, Joseph E.

    2015-01-01

    Carbapenem antimicrobials are critically important to human health and they are often the only remaining effective antibiotics for treating serious infections. Resistance to these drugs mediated by acquired carbapenemase enzymes is increasingly encountered in gram-negative bacteria and is considered a public health emergency. Animal origin food products are recognized as a potential source of resistant organisms, although carbapenem resistance has only recently been reported. In western countries there are active resistance surveillance programs targeting food animals and retail meat products. These programs primarily target beef, pork and poultry and focus exclusively on E. coli, Salmonella, Campylobacter spp. and Enterococcus spp. This global surveillance strategy does not capture the diversity of foods available nor does it address the presence of resistance gene-bearing mobile genetic elements in non-pathogenic bacterial taxa. To address this gap, a total of 121 seafood products originating in Asia purchased from retail groceries in Canada were tested. Samples were processed using a taxa-independent method for the selective isolation of carbapenem resistant organisms. Isolates were characterized by phenotypic antimicrobial susceptibility testing, PCR and DNA sequencing. Carbapenemase producing bacteria, all blaOXA-48, were isolated from 4 (3.3%) of the samples tested. Positive samples originated from China (n=2) and Korea (n=2) and included squid, sea squirt, clams and seafood medley. Carbapenemase producing organisms found include Pseudomonas, Stenotrophomonas and Myroides species. These findings suggest that non-pathogenic bacteria, excluded from resistance surveillance programs, in niche market meats may serve as a reservoir of carbapenemase genes in the food supply. PMID:25966303

  13. Contribution of the Microbial Communities Detected on an Oil Painting on Canvas to Its Biodeterioration

    PubMed Central

    López-Miras, María del Mar; Martín-Sánchez, Inés; Yebra-Rodríguez, África; Romero-Noguera, Julio; Bolívar-Galiano, Fernando; Ettenauer, Jörg; Sterflinger, Katja; Piñar, Guadalupe

    2013-01-01

    In this study, we investigated the microbial community (bacteria and fungi) colonising an oil painting on canvas, which showed visible signs of biodeterioration. A combined strategy, comprising culture-dependent and -independent techniques, was selected. The results derived from the two techniques were disparate. Most of the isolated bacterial strains belonged to related species of the phylum Firmicutes, as Bacillus sp. and Paenisporosarcina sp., whereas the majority of the non-cultivable members of the bacterial community were shown to be related to species of the phylum Proteobacteria, as Stenotrophomonas sp. Fungal communities also showed discrepancies: the isolated fungal strains belonged to different genera of the order Eurotiales, as Penicillium and Eurotium, and the non-cultivable belonged to species of the order Pleosporales and Saccharomycetales. The cultivable microorganisms, which exhibited enzymatic activities related to the deterioration processes, were selected to evaluate their biodeteriorative potential on canvas paintings; namely Arthrobacter sp. as the representative bacterium and Penicillium sp. as the representative fungus. With this aim, a sample taken from the painting studied in this work was examined to determine the stratigraphic sequence of its cross-section. From this information, “mock paintings,” simulating the structure of the original painting, were prepared, inoculated with the selected bacterial and fungal strains, and subsequently examined by micro-Fourier Transform Infrared spectroscopy, in order to determine their potential susceptibility to microbial degradation. The FTIR-spectra revealed that neither Arthrobacter sp. nor Penicillium sp. alone, were able to induce chemical changes on the various materials used to prepare “mock paintings.” Only when inoculated together, could a synergistic effect on the FTIR-spectra be observed, in the form of a variation in band position on the spectrum. PMID:24312203

  14. Tertiary structure-related activity of tick defensin (persulcatusin) in the taiga tick, Ixodes persulcatus.

    PubMed

    Isogai, Emiko; Isogai, Hiroshi; Okumura, Kazuhiko; Hori, Hatsuhiro; Tsuruta, Hiroki; Kurebayashi, Yoichi

    2011-01-01

    Defensins are small cysteine-rich cationic proteins found in both vertebrates and invertebrates constituting the front line of host innate immunity. To examine the importance of the tertiary structure of tick defensin in its antimicrobial activity, we synthesized two types of the peptides with tertiary structure or primary one on basis of the information of the sequence in the defensin originated from the taiga tick, Ixodes persulcatus. Chemically synthesized peptides were used to investigate the activity spectrum against Staphylococcus aureus, Borrelia garinii and flora-associated bacteria. Both synthetic peptides showed antimicrobial activity against S. aureus in short-time killing within 1 h, but they do not show the activity against B. garinii, Stenotrophomonas maltophila and Bacillus spp., which were frequently isolated from the midgut of I. persulcatus. The teriary structure brought more potent activity to S. aureus than primary one in short-time killing. We also examined its antimicrobial activity by evaluation of growth inhibition in the presence of the synthetic peptides. Minimum inhibitory concentration (MIC) was ranged from 1.2 to 5.0 ?g/ml in tertiary peptide and from 10 to 40 ?g/ml in primary peptide, when 10 strains of S. aureus were used. From the curve of cumulative inhibition rates, MIC50 (MIC which half of the strains showed) to S. aureus is about 1.2 ?g/ml in the peptide with tertiary structure and about 10 ?g/ml in the linear one. Corynebacterium renale is 10 times or more sensitive to tertiary peptide than primary one. In conclusion, the presence of 3 disulfide bridges, which stabilize the molecule and maintain the tertiary structure, is considered to have an effect on their antimicrobial activities against Gram-positive bacteria such as S. aureus. PMID:20596886

  15. Bacterial community analysis in chlorpyrifos enrichment cultures via DGGE and use of bacterial consortium for CP biodegradation.

    PubMed

    Akbar, Shamsa; Sultan, Sikander; Kertesz, Michael

    2014-10-01

    The organophosphate pesticide chlorpyrifos (CP) has been used extensively since the 1960s for insect control. However, its toxic effects on mammals and persistence in environment necessitate its removal from contaminated sites, biodegradation studies of CP-degrading microbes are therefore of immense importance. Samples from a Pakistani agricultural soil with an extensive history of CP application were used to prepare enrichment cultures using CP as sole carbon source for bacterial community analysis and isolation of CP metabolizing bacteria. Bacterial community analysis (denaturing gradient gel electrophoresis) revealed that the dominant genera enriched under these conditions were Pseudomonas, Acinetobacter and Stenotrophomonas, along with lower numbers of Sphingomonas, Agrobacterium and Burkholderia. Furthermore, it revealed that members of Bacteroidetes, Firmicutes, ?- and ?-Proteobacteria and Actinobacteria were present at initial steps of enrichment whereas ?-Proteobacteria appeared in later steps and only Proteobacteria were selected by enrichment culturing. However, when CP-degrading strains were isolated from this enrichment culture, the most active organisms were strains of Acinetobacter calcoaceticus, Pseudomonas mendocina and Pseudomonas aeruginosa. These strains degraded 6-7.4 mg L(-1) day(-1) of CP when cultivated in mineral medium, while the consortium of all four strains degraded 9.2 mg L(-1) day(-1) of CP (100 mg L(-1)). Addition of glucose as an additional C source increased the degradation capacity by 8-14 %. After inoculation of contaminated soil with CP (200 mg kg(-1)) disappearance rates were 3.83-4.30 mg kg(-1) day(-1) for individual strains and 4.76 mg kg(-1) day(-1) for the consortium. These results indicate that these organisms are involved in the degradation of CP in soil and represent valuable candidates for in situ bioremediation of contaminated soils and waters. PMID:25008559

  16. Isolation and characterization of endophytic bacteria isolated from the leaves of the common bean (Phaseolus vulgaris)

    PubMed Central

    de Oliveira Costa, Leonardo Emanuel; de Queiroz, Marisa Vieira; Borges, Arnaldo Chaer; de Moraes, Celia Alencar; de Araújo, Elza Fernandes

    2012-01-01

    The common bean is one of the most important legumes in the human diet, but little is known about the endophytic bacteria associated with the leaves of this plant. The objective of this study was to characterize the culturable endophytic bacteria of common bean (Phaseolus vulgaris) leaves from three different cultivars (Vermelhinho, Talismã, and Ouro Negro) grown under the same field conditions. The density of endophytic populations varied from 4.5 x 102 to 2.8 x 103 CFU g-1 of fresh weight. Of the 158 total isolates, 36.7% belonged to the Proteobacteria, 32.9% to Firmicutes, 29.7% to Actinobacteria, and 0.6% to Bacteroidetes. The three P. vulgaris cultivars showed class distribution differences among Actinobacteria, Alphaproteobacteria and Bacilli. Based on 16S rDNA sequences, 23 different genera were isolated comprising bacteria commonly associated with soil and plants. The genera Bacillus, Delftia, Methylobacterium, Microbacterium, Paenibacillus, Staphylococcus and Stenotrophomonas were isolated from all three cultivars. To access and compare the community structure, diversity indices were calculated. The isolates from the Talismã cultivar were less diverse than the isolates derived from the other two cultivars. The results of this work indicate that the cultivar of the plant may contribute to the structure of the endophytic community associated with the common bean. This is the first report of endophytic bacteria from the leaves of P. vulgaris cultivars. Future studies will determine the potential application of these isolates in biological control, growth promotion and enzyme production for biotechnology. PMID:24031988

  17. Reversible oxygen-tolerant hydrogenase carried by free-living N2-fixing bacteria isolated from the rhizospheres of rice, maize, and wheat

    PubMed Central

    Roumagnac, Philippe; Richaud, Pierre; Barakat, Mohamed; Ortet, Philippe; Roncato, Marie-Anne; Heulin, Thierry; Peltier, Gilles; Achouak, Wafa; Cournac, Laurent

    2012-01-01

    Hydrogen production by microorganisms is often described as a promising sustainable and clean energy source, but still faces several obstacles, which prevent practical application. Among them, oxygen sensitivity of hydrogenases represents one of the major limitations hampering the biotechnological implementation of photobiological production processes. Here, we describe a hierarchical biodiversity-based approach, including a chemochromic screening of hydrogenase activity of hundreds of bacterial strains collected from several ecosystems, followed by mass spectrometry measurements of hydrogenase activity of a selection of the H2-oxidizing bacterial strains identified during the screen. In all, 131 of 1266 strains, isolated from cereal rhizospheres and basins containing irradiating waste, were scored as H2-oxidizing bacteria, including Pseudomonas sp., Serratia sp., Stenotrophomonas sp., Enterobacter sp., Rahnella sp., Burkholderia sp., and Ralstonia sp. isolates. Four free-living N2-fixing bacteria harbored a high and oxygen-tolerant hydrogenase activity, which was not fully inhibited within entire cells up to 150–250 ?mol/L O2 concentration or within soluble protein extracts up to 25–30 ?mol/L. The only hydrogenase-related genes that we could reveal in these strains were of the hyc type (subunits of formate hydrogenlyase complex). The four free-living N2-fixing bacteria were closely related to Enterobacter radicincitans based on the sequences of four genes (16S rRNA, rpoB, hsp60, and hycE genes). These results should bring interesting prospects for microbial biohydrogen production and might have ecophysiological significance for bacterial adaptation to the oxic–anoxic interfaces in the rhizosphere. PMID:23233392

  18. Spatial and Species Variations in Bacterial Communities Associated with Corals from the Red Sea as Revealed by Pyrosequencing

    PubMed Central

    Lee, On On; Yang, Jiangke; Bougouffa, Salim; Wang, Yong; Batang, Zenon; Tian, Renmao; Al-Suwailem, Abdulaziz

    2012-01-01

    Microbial associations with corals are common and are most likely symbiotic, although their diversity and relationships with environmental factors and host species remain unclear. In this study, we adopted a 16S rRNA gene tag-pyrosequencing technique to investigate the bacterial communities associated with three stony Scleractinea and two soft Octocorallia corals from three locations in the Red Sea. Our results revealed highly diverse bacterial communities in the Red Sea corals, with more than 600 ribotypes detected and up to 1,000 species estimated from a single coral species. Altogether, 21 bacterial phyla were recovered from the corals, of which Gammaproteobacteria was the most dominant group, and Chloroflexi, Chlamydiae, and the candidate phylum WS3 were reported in corals for the first time. The associated bacterial communities varied greatly with location, where environmental conditions differed significantly. Corals from disturbed areas appeared to share more similar bacterial communities, but larger variations in community structures were observed between different coral species from pristine waters. Ordination methods identified salinity and depth as the most influential parameters affecting the abundance of Vibrio, Pseudoalteromonas, Serratia, Stenotrophomonas, Pseudomonas, and Achromobacter in the corals. On the other hand, bacteria such as Chloracidobacterium and Endozoicomonas were more sensitive to the coral species, suggesting that the host species type may be influential in the associated bacterial community, as well. The combined influences of the coral host and environmental factors on the associated microbial communities are discussed. This study represents the first comparative study using tag-pyrosequencing technology to investigate the bacterial communities in Red Sea corals. PMID:22865078

  19. Pyrosequencing analysis of bacterial diversity in dental unit waterlines.

    PubMed

    Costa, Damien; Mercier, Anne; Gravouil, Kevin; Lesobre, Jérôme; Delafont, Vincent; Bousseau, Anne; Verdon, Julien; Imbert, Christine

    2015-09-15

    Some infections cases due to exposure to output water from dental unit waterlines (DUWL) have been reported in the literature. However, this type of healthcare-associated risk has remained unclear and up until now the overall bacterial composition of DUWL has been poorly documented. In this study, 454 high-throughput pyrosequencing was used to investigate the bacterial community in seven dental offices (N = 7) and to identify potential bacterial pathogenic sequences. Dental unit waters (DUW) were collected from the tap water supplying units (Incoming Water; IW) to the output exposure point of the turbine handpiece (Output water; OW) following a stagnation period (OWS), and immediately after the last patient of the sampling day (OWA). A high bacterial diversity was revealed in DUW with 394 operational taxonomic units detected at the genus level. In addition to the inter-unit variability observed, results showed increased total bacterial cell concentration and shifts in bacterial community composition and abundance at the genus level, mainly within the Gamma- and Alpha-Proteobacteria class, as water circulated in the dental unit (DU). Results showed that 96.7%, 96.8% and 97.4% of the total sequences from IW, OWS and OWA respectively were common to the 3 defined water groups, thereby highlighting a common core microbiome. Results also suggested that stagnation and DU maintenance practices were critical to composition of the bacterial community. The presence of potentially pathogenic genera was detected, including Pseudomonas and Legionella spp. Emerging and opportunistic pathogenic genera such as Mycobacterium, Propionibacterium and Stenotrophomonas were likewise recovered in DUW. For the first time, an exhaustive evaluation of the bacterial communities present in DUW was performed taking into account the circulation of water within the DU. This study highlights an ignored diversity of the DUWL bacterial community. Our findings also contribute to a better appreciation of the potential infectious risk associated with dental care and suggest the importance of better managing microbial quality in DUW. PMID:26072020

  20. Differences between the rhizosphere microbiome of Beta vulgaris ssp. maritima—ancestor of all beet crops—and modern sugar beets

    PubMed Central

    Zachow, Christin; Müller, Henry; Tilcher, Ralf; Berg, Gabriele

    2014-01-01

    The structure and function of the plant microbiome is driven by plant species and prevailing environmental conditions. Effectuated by breeding efforts, modern crops diverge genetically and phenotypically from their wild relatives but little is known about consequences for the associated microbiota. Therefore, we studied bacterial rhizosphere communities associated with the wild beet B. vulgaris ssp. maritima grown in their natural habitat soil from coastal drift lines (CS) and modern sugar beets (Beta vulgaris ssp. vulgaris) cultivated in CS and potting soil (PS) under greenhouse conditions. Analysis of 16S rRNA gene fingerprints and pyrosequencing-based amplicon libraries revealed plant genotype- and soil-specific microbiomes. Wild beet plants harbor distinct operational taxonomic units (OTUs) and a more diverse bacterial community than the domesticated sugar beet plants. Although the rhizospheres of both plant genotypes were dominated by Proteobacteria and Planctomycetes, 37.5% of dominant OTUs were additionally detected in the wild beet rhizosphere. Analysis of the cultivable fraction confirmed these plant genotype-specific differences at functional level. The proportion of isolates displayed in vitro activity against phytopathogens was lower for wild beet (?45.8%) than for sugar beet (?57.5%). Conversely, active isolates from the wild beet exhibited stronger ability to cope with abiotic stresses. From all samples, active isolates of Stenotrophomonas rhizophila were frequently identified. In addition, soil type-specific impacts on the composition of bacterial communities were found: Acidobacteria, Chloroflexi, and Planctomycetes were only detected in plants cultivated in CS; whereas Bacteroidetes and Proteobacteria dominated in PS. Overall, in comparison to modern sugar beets, wild beets were associated with taxonomically and functionally distinct microbiomes. PMID:25206350

  1. Ecophysiological properties of cultivable heterotrophic bacteria and yeasts dominating in phytocenoses of Galindez Island, maritime Antarctica.

    PubMed

    Vasileva-Tonkova, Evgenia; Romanovskaya, Victoria; Gladka, Galina; Gouliamova, Dilnora; Tomova, Iva; Stoilova-Disheva, Margarita; Tashyrev, Oleksandr

    2014-04-01

    Antarctic plants are stable specific microenvironments for microbial colonization that are still less explored. In this study, we investigated cultivable heterotrophic bacteria and yeasts dominating in plant samples collected from different terrestrial biotopes near Ukrainian Antarctic Base on Galindez Island, maritime Antarctica. Phylogenetic analysis revealed affiliation of the bacterial isolates to genera Pseudomonas, Stenotrophomonas, Brevundimonas, Sporosarcina, Dermacoccus, Microbacterium, Rothia and Frondihabitans, and the yeast isolates to genera Rhodosporidium, Cryptococcus, Leucosporidiella, Candida and Exophiala. Some ecophysiological properties of isolated strains were determined that are important in response to different stresses such as psychro- and halotolerance, UV-resistance and production of hydrolytic enzymes. The majority of isolates (88 %) was found to be psychrotolerant; all are halotolerant. Significant differences in survival subsequent to UV-C radiation were observed among the isolates, as measured by culturable counts. For the bacterial isolates, lethal doses in the range 80-600 J m?² were determined, and for the yeast isolates--in the range 300-1,000 J m?². Dermacoccus profundi U9 and Candida davisiana U6 were found as most UV resistant among the bacterial and yeast isolates, respectively. Producers of caseinase, gelatinase, ?-glucosidase, and cellulase were detected. To the best of our knowledge, this is the first report on isolation of UV resistant strain D. profundi, and Frondihabitans strain from Antarctica, and on detection of cellulase activity in Antarctic yeast strain C. davisiana. The results obtained contribute to clarifying adaptation strategies of Antarctic microbiota and its possible role in functional stability of Antarctic biocenoses. Stress tolerant strains were detected that are valuable for ecological and applied studies. PMID:24277323

  2. Molecular and lipid biomarker analysis of a gypsum-hosted endoevaporitic microbial community.

    PubMed

    Jahnke, L L; Turk-Kubo, K A; N Parenteau, M; Green, S J; Kubo, M D Y; Vogel, M; Summons, R E; Des Marais, D J

    2014-01-01

    Modern evaporitic microbial ecosystems are important analogs for understanding the record of earliest life on Earth. Although mineral-depositing shallow-marine environments were prevalent during the Precambrian, few such environments are now available today for study. We investigated the molecular and lipid biomarker composition of an endoevaporitic gypsarenite microbial mat community in Guerrero Negro, Mexico. The 16S ribosomal RNA gene-based phylogenetic analyses of this mat corroborate prior observations indicating that characteristic layered microbial communities colonize gypsum deposits world-wide despite considerable textural and morphological variability. Membrane fatty acid analysis of the surface tan/orange and lower green mat crust layers indicated cell densities of 1.6 × 10(9) and 4.2 × 10(9)  cells cm(-3) , respectively. Several biomarker fatty acids, ?7,10-hexadecadienoic, iso-heptadecenoic, 10-methylhexadecanoic, and a ?12-methyloctadecenoic, correlated well with distributions of Euhalothece, Stenotrophomonas, Desulfohalobium, and Rhodobacterales, respectively, revealed by the phylogenetic analyses. Chlorophyll (Chl) a and cyanobacterial phylotypes were present at all depths in the mat. Bacteriochlorophyl (Bchl) a and Bchl c were first detected in the oxic-anoxic transition zone and increased with depth. A series of monomethylalkanes (MMA), 8-methylhexadecane, 8-methylheptadecane, and 9-methyloctadecane were present in the surface crust but increased in abundance in the lower anoxic layers. The MMA structures are similar to those identified previously in cultures of the marine Chloroflexus-like organism 'Candidatus Chlorothrix halophila' gen. nov., sp. nov., and may represent the Bchl c community. Novel 3-methylhopanoids were identified in cultures of marine purple non-sulfur bacteria and serve as a probable biomarker for this group in the lower anoxic purple and olive-black layers. Together microbial culture and environmental analyses support novel sources for lipid biomarkers in gypsum crust mats. PMID:24325308

  3. The coupling of the plant and microbial catabolisms of phenanthrene in the rhizosphere of Medicago sativa.

    PubMed

    Muratova, Anna; Dubrovskaya, Ekaterina; Golubev, Sergey; Grinev, Vyacheslav; Chernyshova, Marina; Turkovskaya, Olga

    2015-09-01

    We studied the catabolism of the polycyclic aromatic hydrocarbon phenanthrene by four rhizobacterial strains and the possibility of enzymatic oxidation of this compound and its microbial metabolites by the root exudates of alfalfa (Medicago sativa L.) in order to detect the possible coupling of the plant and microbial metabolisms under the rhizospheric degradation of the organic pollutant. A comparative study of phenanthrene degradation pathways in the PAH-degrading rhizobacteria Ensifer meliloti, Pseudomonas kunmingensis, Rhizobium petrolearium, and Stenotrophomonas sp. allowed us to identify the key metabolites from the microbial transformation of phenanthrene, including 9,10-phenanthrenequinone, 2-carboxybenzaldehyde, and 1-hydroxy-2-naphthoic, salicylic, and o-phthalic acids. Sterile alfalfa plants were grown in the presence and absence of phenanthrene (0.03gkg(-1)) in quartz sand under controlled environmental conditions to obtain plant root exudates. The root exudates were collected, concentrated by ultrafiltration, and the activity of oxidoreductases was detected spectrophotometrically by the oxidation rate for various substrates. The most marked activity was that of peroxidase, whereas the presence of oxidase and tyrosinase was detected on the verge of the assay sensitivity. Using alfalfa root exudates as a crude enzyme preparation, we found that in the presence of the synthetic mediator, the plant peroxidase could oxidize phenanthrene and its microbial metabolites. The results indicate the possibility of active participation of plants in the rhizospheric degradation of polycyclic aromatic hydrocarbons and their microbial metabolites, which makes it possible to speak about the coupling of the plant and microbial catabolisms of these contaminants in the rhizosphere. PMID:26398627

  4. Phylogenetic analyses of the genus Glaciecola: emended description of the genus Glaciecola, transfer of Glaciecola mesophila, G. agarilytica, G. aquimarina, G. arctica, G. chathamensis, G. polaris and G. psychrophila to the genus Paraglaciecola gen. nov. as Paraglaciecola mesophila comb. nov., P. agarilytica comb. nov., P. aquimarina comb. nov., P. arctica comb. nov., P. chathamensis comb. nov., P. polaris comb. nov. and P. psychrophila comb. nov., and description of Paraglaciecola oceanifecundans sp. nov., isolated from the Southern Ocean.

    PubMed

    Shivaji, Sisinthy; Reddy, Gundlapally Sathyanarayana

    2014-09-01

    Phylogenetic analyses of the genus Glaciecola were performed using the sequences of the 16S rRNA gene and the GyrB protein to establish its taxonomic status. The results indicated a consistent clustering of the genus Glaciecola into two clades, with significant bootstrap values, with all the phylogenetic methods employed. Clade 1 was represented by seven species, Glaciecola agarilytica, G. aquimarina, G. arctica, G. chathamensis, G. mesophila, G. polaris and G. psychrophila, while clade 2 consisted of only three species, Glaciecola nitratireducens, G. pallidula and G. punicea. Evolutionary distances between species of clades 1 and 2, based on 16S rRNA gene and GyrB protein sequences, ranged from 93.0 to 95.0?% and 69.0 to 73.0?%, respectively. In addition, clades 1 and 2 possessed 18 unique signature nucleotides, at positions 132, 184?:?193, 185?:?192, 230, 616?:?624, 631, 632, 633, 738, 829, 1257, 1265, 1281, 1356 and 1366, in the 16S rRNA gene sequence and can be differentiated by the occurrence of a 15 nt signature motif 5'-CAAATCAGAATGTTG at positions 1354-1368 in members of clade 2. Robust clustering of the genus Glaciecola into two clades based on analysis of 16S rRNA gene and GyrB protein sequences, 16S rRNA gene sequence similarity of ?95.0?% and the occurrence of signature nucleotides and signature motifs in the 16S rRNA gene suggested that the genus should be split into two genera. The genus Paraglaciecola gen. nov. is therefore created to accommodate the seven species of clade 1, while the name Glaciecola sensu stricto is retained to represent species of clade 2. The species of clade 1 are transferred to the genus Paraglaciecola as Paraglaciecola mesophila comb. nov. (type strain DSM 15026(T)?=?KMM 241(T)), P. agarilytica comb. nov. (type strain NO2(T)?=?KCTC 12755(T)?=?LMG 23762(T)), P. aquimarina comb. nov. (type strain GGW-M5(T)?=?KCTC 32108(T)?=?CCUG 62918(T)), P. arctica comb. nov. (type strain BSs20135(T)?=?CCTCC AB 209161(T)?=?KACC 14537(T)), P. chathamensis comb. nov. (type strain E3(T)?=?CGMCC 1.7001(T)?=?JCM 15139(T)), P. polaris comb. nov. (type strain ARK 150(T)?=?CIP 108324(T)?=?LMG 21857(T)) and P. psychrophila comb. nov. (type strain 170(T)?=?CGMCC1.6130(T)?=?JCM 13954(T)). The type species of the genus Paraglaciecola is Paraglaciecola mesophila. An emended description of the genus Glaciecola is provided. In addition, a novel strain, 162Z-12(T), was isolated from seawater collected as part of an iron fertilization experiment (LOHAFEX) conducted in the Southern Ocean in 2009 and was subjected to polyphasic taxonomic characterization. Cells of 162Z-12(T) were Gram-negative, aerobic, motile, ovoid to short rod-shaped, obligatorily halophilic and possessed all the characteristics of the genus Paraglaciecola. Strain 162Z-12(T) shared the highest 16S rRNA gene sequence similarity with the type strains of P. agarilytica (99.7?%), P. chathamensis (99.7?%), P. mesophila (98.5?%) and P. polaris (98.3?%). However, it exhibited DNA-DNA relatedness of less than 70.0?% with its nearest phylogenetic relatives, well below the threshold value for species delineation. Further, strain 162Z-12(T) differed from the nearest species in several phenotypic characteristics, in addition to the occurrence of unique nucleotides G, T, T and T at positions 1194, 1269, 1270 and 1271 of the 16S rRNA gene. Based on the cumulative differences it exhibited from its nearest phylogenetic neighbours, strain 162Z-12(T) was identified as a novel member of the genus Paraglaciecola and assigned to the novel species Paraglaciecola oceanifecundans sp. nov. The type strain of Paraglaciecola oceanifecundans is 162Z-12(T) (?=?KCTC 32337(T)?=?LMG 27453(T)). PMID:24981324

  5. The Origin And Spread Of Airborne Bacteria

    NASA Astrophysics Data System (ADS)

    Henderson-Begg, S. K.; Moffett, B. F.

    2009-12-01

    The presence of bacteria in clouds may affect their radiation and precipitation properties as some species are able to catalyse the freezing of water at high temperatures (-2C to -10C). Where cloud-borne bacteria originate and the distances they are able to travel in the air remains a mystery. In this study we have attempted to address these issues by comparing metagenomic DNA sequences from air samples with those from other environmental sources. Air samples were collected on 1 July 2009 from a hill top at Thursley Nature Reserve in Surrey, United Kingdom, a rural site, 31 miles from the nearest stretch of coastline, and on 6 July 2009 from the top of a six storey building in Stratford on the East end of London, 38 miles from the nearest coastal area. Samples were collected using the Karcher DS5500 vacuum into a liquid filled collection vessel at an air flow rate of 3.3 m3 min-1 over a 4 hour period. Samples were then concentrated and the bacterial content was investigated by PCR, cloning and sequencing of 16S rRNA genes. During the collection period on 1 July the Royston Weather Station in the South East of England recorded wind speed of 1.9 miles/hour in an Easterly direction, with no cloud cover, relative humidity of 74% and atmospheric pressure of 1021.6 mB. On 6 July wind speed was 9.8 miles/hour in a South Westerly direction, there was light cloud cover, relative humidity was 73.8% and atmospheric pressure was 1002.8 mB. Twenty cloned 16S PCR products from each air sample were sequenced. The species identification of each clone is shown in Table 1. The diversity of bacteria found at both sites was similar, with Stenotrophomona and Pedobacteria species dominating both samples. When the DNA sequences were blasted against the environmental samples database, all sequences were found to display greatest homology to metagenomic DNA from marine sources. This may suggest that the most numerous bacteria in air samples originate in the oceans. Taking account of the wind speed and direction, marine organisms would have been airborne for at least 16 hours in the Thursley sample and for at least 4 hours in the East London sample. The origin and spread of airborne organisms warrants further investigation.

  6. High-throughput sequencing analysis of the bacteria in the dust storm which passed over Canberra, Australia on 22-23 September 2009

    NASA Astrophysics Data System (ADS)

    Munday, Chris; De Deckker, Patrick; Tapper, Nigel; Allison, Gwen

    2014-05-01

    Following a prolonged drought in Australia in the first decade of the 21st century, several dust storms affected the heavily populated East coast of Australia. The largest such storm occurred on 22-23 September 2009 and had a front of an estimated 3000km. A 24hr average PM10 concentration of over 2,000?g/m3 was recorded in several locations and an hourly peak of over 15,000?g/m3 was recorded (Leys et al. 2011). Over two time periods duplicate aerosol samples were collected on 47mm diameter cellulose nitrate membranes at a location removed from anthropogenic influences. One set of samples was collected in the afternoon the dust event started and another was collected overnight. Additionally, overnight rainfall was collected in a sterile bottle.DNA was directly extracted one membrane from each time point for molecular cloning and high throughput sequencing, while the other was cultivated on Tryptic Soy Agar (TSA). High throughput sequencing was performed using the 454 Titanium platform. From the three samples, 19,945 curated sequences were obtained representing 942 OTUS, with the three samples approximately equal in number. Unclassified Rhizobiales and Stenotrophomonas were the most abundant groups which could be attributed names. A total of 942 OTUs were identified (cutoff = 0.03), and despite the temporal relation of the samples, only eleven were found in all three samples, indicating that the dust storm evolved in composition as it passed over the region. Approximately 800 and 500 CFU/m3 were found in the two cultivated samples, tenfold more than was collected from previous dust events (Lim et al, 2011). Identification of cultivars revealed a dominance of the gram positive Firmicutes phylum, while the clone library showed a more even distribution of taxa, with Actinobacteria the most common and Firmicutes comprising less than 10% of sequences. Collectively, the analyses indicate that the concentration of cultivable organisms during the dust storm dramatically relative to calm conditions. A diverse and variable population of microorganisms were present reflecting the vast source and dynamic nature of the storm.

  7. The hyperaccumulator Sedum plumbizincicola harbors metal-resistant endophytic bacteria that improve its phytoextraction capacity in multi-metal contaminated soil.

    PubMed

    Ma, Ying; Oliveira, Rui S; Nai, Fengjiao; Rajkumar, Mani; Luo, Yongming; Rocha, Inês; Freitas, Helena

    2015-06-01

    Endophyte-assisted phytoremediation has recently been suggested as a successful approach for ecological restoration of metal contaminated soils, however little information is available on the influence of endophytic bacteria on the phytoextraction capacity of metal hyperaccumulating plants in multi-metal polluted soils. The aims of our study were to isolate and characterize metal-resistant and 1-aminocyclopropane-1-carboxylate (ACC) utilizing endophytic bacteria from tissues of the newly discovered Zn/Cd hyperaccumulator Sedum plumbizincicola and to examine if these endophytic bacterial strains could improve the efficiency of phytoextraction of multi-metal contaminated soils. Among a collection of 42 metal resistant bacterial strains isolated from the tissues of S. plumbizincicola grown on Pb/Zn mine tailings, five plant growth promoting endophytic bacterial strains (PGPE) were selected due to their ability to promote plant growth and to utilize ACC as the sole nitrogen source. The five isolates were identified as Bacillus pumilus E2S2, Bacillus sp. E1S2, Bacillus sp. E4S1, Achromobacter sp. E4L5 and Stenotrophomonas sp. E1L and subsequent testing revealed that they all exhibited traits associated with plant growth promotion, such as production of indole-3-acetic acid and siderophores and solubilization of phosphorus. These five strains showed high resistance to heavy metals (Cd, Zn and Pb) and various antibiotics. Further, inoculation of these ACC utilizing strains significantly increased the concentrations of water extractable Cd and Zn in soil. Moreover, a pot experiment was conducted to elucidate the effects of inoculating metal-resistant ACC utilizing strains on the growth of S. plumbizincicola and its uptake of Cd, Zn and Pb in multi-metal contaminated soils. Out of the five strains, B. pumilus E2S2 significantly increased root (146%) and shoot (17%) length, fresh (37%) and dry biomass (32%) of S. plumbizincicola as well as plant Cd uptake (43%), whereas Bacillus sp. E1S2 significantly enhanced the accumulation of Zn (18%) in plants compared with non-inoculated controls. The inoculated strains also showed high levels of colonization in rhizosphere and plant tissues. Results demonstrate the potential to improve phytoextraction of soils contaminated with multiple heavy metals by inoculating metal hyperaccumulating plants with their own selected functional endophytic bacterial strains. PMID:25796039

  8. Molecular analysis of bacterial population structure and dynamics during cold storage of untreated and treated milk.

    PubMed

    Rasolofo, Eric Andriamahery; St-Gelais, Daniel; LaPointe, Gisele; Roy, Denis

    2010-03-31

    Spoilage bacteria in milk are controlled by treatments such as thermization, microfiltration and addition of carbon dioxide. However, little information is known about the changes in microbial communities during subsequent cold storage of treated milk. Culture-dependent methods and a direct molecular approach combining 16S rRNA gene clone libraries and quantitative PCR (Q-PCR) were applied to obtain a better overview of the structure and the dynamics of milk microbiota. Raw milk samples were treated by the addition of carbon dioxide (CO(2)), thermization (TH) or microfiltration (MF) and stored at 4 degrees C or 8 degrees C up to 7d. Untreated milk (UT) was used as a control. Psychrotrophic and staphylococci bacteria were enumerated in the milk samples by culture methods. For the molecular approach, DNA was extracted from milk samples and 16S rRNA gene was amplified by PCR with universal primers prior to cloning. The Q-PCR method was used to evaluate the dynamics of dominant bacterial species revealed by clone library analysis of 16S rRNA gene. Comparison of the 16S rRNA gene sequence indicated that the two most abundant operational taxonomic units (OTU), determined at 97% identity, belonged to the class Gammaproteobacteria (40.3% of the 1415 sequences) and Bacilli (40%). Dominant bacterial species in UT, CO(2) and TH milk samples at day 3 were affiliated with Staphylococcus, Streptococcus, Clostridia, Aerococcus, Facklamia, Corynebacterium, Acinetobacter and Trichococcus. Dominant bacterial species detected in MF milk were Stenotrophomonas, Pseudomonas and Delftia, while Pseudomonas species dominated the bacterial population of UT, CO(2) and MF milk samples at day 7. Staphylococcus and Delftia were the dominant bacterial species in thermized milk. Q-PCR results showed that populations of S. aureus, A. viridans, A. calcoaceticus, C. variabile and S. uberis were stable during 7d of storage at 4 degrees C. Populations of P. fluorescens, S. uberis and total bacteria increased in UT and CO(2) milk samples during 7d of storage at 8 degrees C and were noticeable from day 3. This study shows new microbial species which can develop during cold storage after milk treatment and contributes to identifying causes of reduced shelf life and deterioration of technological properties of milk during storage. PMID:20137820

  9. Vertical distribution of the subsurface microorganisms in Sagara oil reservoir

    NASA Astrophysics Data System (ADS)

    Nunoura, T.; Oida, H.; Masui, N.; Ingaki, F.; Takai, K.; Nealson, K. H.; Horikoshi, K.

    2002-12-01

    The recent microbiological studies reported that active microbial habitat for methanogen, sulfate reducers (Archaeoglobus, d-Proteobacteria, gram positives), fermenters (Thermococcus, Thermotogales, gram positives etc.) and other heterotrophs (g-Proteobacteria etc.) are in subsurface petroleum oil reservoirs. However, microbial distribution at vertical distances in depth has not been demonstrated since the samples in previous studies are only to use oil and the formation water. Here, we show the vertical profile of microbial community structure in Japanese terrestrial oil reservoir by a combination of molecular ecological analyses and culture dependent studies. The sequential WRC (Whole Round Core) samples (200 mbsf) were recovered from a drilling project for Sagara oil reservoir, Shizuoka Prefecture, Japan, conducted in Jar. -Mar. 2002. The lithology of the core samples was composed of siltstone, sandstone, or partially oil containing sand. The major oil components were gasoline, kerosene and light oil, that is a unique feature observed in the Sagara oil reservoir. The direct count of DAPI-stained cells suggested that the biomass was relatively constant, 1.0x104cells/g through the core of the non-oil layers, whereas the oil-bearing layers had quite higher population density at a range of 1.0x105 ? 3.7x107cells/g. The vertical profile of microbial community structures was analyzed by the sequence similarity analysis, phylogenetic analysis and T-RFLP fingerprinting of PCR-amplified 16S rDNA. From bacterial rDNA clone libraries, most of the examined rDNA were similar with the sequence of genera Pseudomanas, Stenotrophomonas and Sphingomonas within g-Proteobacteria. Especially, Pseudomonas stutzeri was predominantly present in all oil-bearing layers. From archaeal rDNA clone libraries, all rDNA clone sequences were phylogenetically associated with uncultured soil group in Crenarchaeota. We detected none of the sequences of sulfate reducers, sulfur dependent fermenters and methanogens that have been previously detected as dominant microbial components in other oil reservoir environments. The absence of methanogen was consistent with the results from the stable isotopic analysis that major hydrocarbon components including methane in Sagara oil reservoir are thermogenic origin. In this presentation, we will also show the activity of the subsurface microbial components by the cultivation assays and discuss about the relationship between the microbial community structure and the formation process of petroleum in Sagara oil reservoir.

  10. Delving into the Deep Biosphere

    NASA Astrophysics Data System (ADS)

    Grim, S. L.; Sogin, M. L.; Boetius, A.; Briggs, B. R.; Brazelton, W. J.; D'Hondt, S. L.; Edwards, K. J.; Fisk, M. R.; Gaidos, E.; Gralnick, J.; Hinrichs, K.; Lazar, C.; Lavalleur, H.; Lever, M. A.; Marteinsson, V.; Moser, D. P.; Orcutt, B.; Pedersen, K.; Popa, R.; Ramette, A.; Schrenk, M. O.; Sylvan, J. B.; Smith, A. R.; Teske, A.; Walsh, E. A.; Colwell, F. S.

    2013-12-01

    The Census of Deep Life organized an international survey of microbial community diversity in terrestrial and marine deep subsurface environments. Habitats included subsurface continental fractured rock aquifers, volcanic and metamorphic subseafloor sedimentary units from the open ocean, subsurface oxic and anoxic sediments and underlying basaltic oceanic crust, and their overlying water columns. Our survey employed high-throughput pyrosequencing of the hypervariable V4-V6 16S rRNA gene of bacteria and archaea. We detected 1292 bacterial genera representing 40 phyla, and 99 archaeal genera from 30 phyla. Of these, a core group of thirteen bacterial genera occurred in every environment. A genus of the South African Goldmine Group (Euryarchaeota) was always present whenever archaea were detected. Members of the rare biosphere in one system often represented highly abundant taxa in other environments. Dispersal could account for this observation but mechanisms of transport remain elusive. Ralstonia (Betaproteobacteria) represented highly abundant taxa in marine communities and terrestrial rock, but generally low abundance organisms in groundwater. Some of these taxa could represent sample contamination, and their extensive distribution in several systems requires further assessment. An unknown Sphingobacteriales (Bacteroidetes) genus, Stenotrophomonas (Gammaproteobacteria), Acidovorax and Aquabacterium (both Betaproteobacteria), a Chlorobiales genus, and a TM7 genus were in the core group as well but more prevalent in terrestrial environments. Similarly, Bacillus (Firmicutes), a new cyanobacterial genus, Bradyrhizobium and Sphingomonas (both Alphaproteobacteria), a novel Acidobacteriaceae genus, and Variovorax (Betaproteobacteria) frequently occurred in marine systems but represented low abundance taxa in other environments. Communities tended to cluster by biome and material, and many genera were unique to systems. For example, certain Rhizobiales (Alphaproteobacteria) only occurred in groundwater, and select Firmicutes and actinobacterial taxa were specific to rock environments. We continue to investigate the ecological and physiological context of these organisms. By combining deep sequencing of microbial communities and geochemical and physical evaluations of their environments, we bring to light the diversity and scope of the deep biosphere and insight into the factors that determine the nature of these communities.

  11. Characterization of two diesel fuel degrading microbial consortia enriched from a non acclimated, complex source of microorganisms

    PubMed Central

    2010-01-01

    Background The bioremediation of soils impacted by diesel fuels is very often limited by the lack of indigenous microflora with the required broad substrate specificity. In such cases, the soil inoculation with cultures with the desired catabolic capabilities (bioaugmentation) is an essential option. The use of consortia of microorganisms obtained from rich sources of microbes (e.g., sludges, composts, manure) via enrichment (i.e., serial growth transfers) on the polluting hydrocarbons would provide bioremediation enhancements more robust and reproducible than those achieved with specialized pure cultures or tailored combinations (co-cultures) of them, together with none or minor risks of soil loading with unrelated or pathogenic allocthonous microorganisms. Results In this work, two microbial consortia, i.e., ENZ-G1 and ENZ-G2, were enriched from ENZYVEBA (a complex commercial source of microorganisms) on Diesel (G1) and HiQ Diesel (G2), respectively, and characterized in terms of microbial composition and hydrocarbon biodegradation capability and specificity. ENZ-G1 and ENZ-G2 exhibited a comparable and remarkable biodegradation capability and specificity towards n-C10 to n-C24 linear paraffins by removing about 90% of 1 g l-1 of diesel fuel applied after 10 days of aerobic shaken flask batch culture incubation at 30°C. Cultivation dependent and independent approaches evidenced that both consortia consist of bacteria belonging to the genera Chryseobacterium, Acinetobacter, Psudomonas, Stenotrophomonas, Alcaligenes and Gordonia along with the fungus Trametes gibbosa. However, only the fungus was found to grow and remarkably biodegrade G1 and G2 hydrocarbons under the same conditions. The biodegradation activity and specificity and the microbial composition of ENZ-G1 and ENZ-G2 did not significantly change after cryopreservation and storage at -20°C for several months. Conclusions ENZ-G1 and ENZ-G2 are very similar highly enriched consortia of bacteria and a fungus capable of extensively degrading a broad range of the hydrocarbons mainly composing diesel fuels. Given their remarkable biodegradation potential, stability and resistance to cryopreservation, both consortia appear very interesting candidates for bioaugmentation operations on Diesel fuel impacted soils and sites. PMID:20158909

  12. Genes involved in arsenic transformation and resistance associated with different levels of arsenic-contaminated soils

    PubMed Central

    2009-01-01

    Background Arsenic is known as a toxic metalloid, which primarily exists in inorganic form [As(III) and As(V)] and can be transformed by microbial redox processes in the natural environment. As(III) is much more toxic and mobile than As(V), hence microbial arsenic redox transformation has a major impact on arsenic toxicity and mobility which can greatly influence the human health. Our main purpose was to investigate the distribution and diversity of microbial arsenite-resistant species in three different arsenic-contaminated soils, and further study the As(III) resistance levels and related functional genes of these species. Results A total of 58 arsenite-resistant bacteria were identified from soils with three different arsenic-contaminated levels. Highly arsenite-resistant bacteria (MIC > 20 mM) were only isolated from the highly arsenic-contaminated site and belonged to Acinetobacter, Agrobacterium, Arthrobacter, Comamonas, Rhodococcus, Stenotrophomonas and Pseudomonas. Five arsenite-oxidizing bacteria that belonged to Achromobacter, Agrobacterium and Pseudomonas were identified and displayed a higher average arsenite resistance level than the non-arsenite oxidizers. 5 aoxB genes encoding arsenite oxidase and 51 arsenite transporter genes [18 arsB, 12 ACR3(1) and 21 ACR3(2)] were successfully amplified from these strains using PCR with degenerate primers. The aoxB genes were specific for the arsenite-oxidizing bacteria. Strains containing both an arsenite oxidase gene (aoxB) and an arsenite transporter gene (ACR3 or arsB) displayed a higher average arsenite resistance level than those possessing an arsenite transporter gene only. Horizontal transfer of ACR3(2) and arsB appeared to have occurred in strains that were primarily isolated from the highly arsenic-contaminated soil. Conclusion Soils with long-term arsenic contamination may result in the evolution of highly diverse arsenite-resistant bacteria and such diversity was probably caused in part by horizontal gene transfer events. Bacteria capable of both arsenite oxidation and arsenite efflux mechanisms had an elevated arsenite resistance level. PMID:19128515