Science.gov

Sample records for stenotrophomonas maltophilia cgmcc

  1. Screening, purification and characterization of a novel cold-active and organic solvent-tolerant lipase from Stenotrophomonas maltophilia CGMCC 4254.

    PubMed

    Li, Mu; Yang, Li-Rong; Xu, Gang; Wu, Jian-Ping

    2013-11-01

    An extracellular organic solvent-tolerant and cold-active lipase producing bacterium was isolated from oil-contaminated soil samples, and identified taxonomically as Stenotrophomonas maltophilia. The lipase from S. maltophilia CGMCC 4254 (SML) was purified 60.5-fold to homogeneity with 38.9 U/mg specific activity. Partially purified SML displayed remarkable stability in 50% and 100% (v/v) hydrophobic organic solvents after incubation for 7 days. The enzyme also retained more than 50% of its residual activity in several pure hydrophilic organic solvents after incubation for 7 days. SML showed 57% maximum activity at 5°C, and had optimal activity at 35°C. These unique properties of SML make it promising as a biocatalyst for industrial processes. PMID:24050922

  2. Genetic Manipulation of Stenotrophomonas maltophilia

    PubMed Central

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

    2015-01-01

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

  3. Stenotrophomonas maltophilia: 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

  4. 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

  5. Fatal hemorrhagic pneumonia: Don't forget Stenotrophomonas maltophilia.

    PubMed

    Gutierrez, Cristina; Pravinkumar, Egbert; Balachandran, Dave; Schneider, Virginia

    2016-01-01

    We present a case of fatal hemorrhagic pneumonia secondary to Stenotrophomonas maltophilia in a patient with acute myeloid leukemia. S. maltophilia is commonly a non-virulent pathogen. However, in the immunocompromised, it is generally associated with bacteremia after central venous catheter placement or pneumonia. Hemorrhagic pneumonia is a rare presentation of this bacteria, with only 31 cases reported in the literature, and has 100% mortality within 72 hours. Rapid recognition and early suspicion should be key in the treatment of these patients. PMID:27358764

  6. Recurrent Stenotrophomonas maltophilia bacteremia after iliac crest bone graft harvest.

    PubMed

    Hagiya, Hideharu; Ogawa, Hiroko; Ishida, Tomoharu; Terasaka, Tomohiro; Kimura, Kosuke; Waseda, Koichi; Hanayama, Yoshihisa; Horita, Masahiro; Shimamura, Yasunori; Kondo, Eisei; Otsuka, Fumio

    2014-01-01

    We describe a rare case of recurrent Stenotrophomonas maltophilia bacteremia in a previously healthy 45-year-old man. The infection was caused by osteomyelitis at the site of an iliac crest bone graft harvest. A genetic analysis using enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) revealed that the blood isolates and pathogens obtained from the surgical wound were identical. Initial treatment with levofloxacin and cefozopran was ineffective, but the patient's infection was successfully treated by long-term administration of latamoxef and trimethoprim-sulfamethoxazole. The present case suggests that attention should be given to the possibility of S. maltophilia infection in any situations. PMID:25088888

  7. Smqnr VARIANTS IN CLINICAL ISOLATES OF Stenotrophomonas maltophilia IN BRAZIL

    PubMed Central

    Gracia-Paez, Jorge Isaac; Ferraz, Juliana Rosa; França E Silva, Ivan Avelino; Rossi, Flávia; Levin, Anna Sara; Costa, Silvia Figueiredo

    2013-01-01

    SUMMARY Stenotrophomonas maltophilia contains a novel chromosomally-encoded qnr gene named Smqnr that contributes to low intrinsic resistance to quinolone. We described Smqnr in 13 clinical isolates of S. maltophilia from two Brazilian hospitals, over a 2-year period. The strains were identified by API 20 NE (bioMérieux, France). Susceptibility by microdilution method to trimetroprim/sulfamethoxazole, ciprofloxacin, levofloxacin, minocycline, ceftazidime, chloramphenicol and ticarcillin/clavulanate was performed according to CLSI. PCR detection of Smqnr gene was carried out. The sequence of Smqnr was compared with those deposited in GenBank. Pulsed-field gel electrophoresis (PFGE) of all strains was performed. Thirteen Smqnr positives isolates were sequenced and three novel variants of Smqnr were identified. All 13 Smqnr isolates had distinguishable patterns by PFGE. This is the first report of Smqnr in S. maltophilia isolated in Brazil. PMID:24213195

  8. 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

  9. Establishment of an arabinose-inducible system in Stenotrophomonas maltophilia.

    PubMed

    Huang, Yi-Wei; Hu, Rouh-Mei; Chiang, Yu-Ting; Chung, Tsao-Chuen; Chung, Tung-Ching; Yang, Tsuey-Ching

    2011-01-01

    A pBBad22T-derived conditioned arabinose (Ara)-inducible expression system was evaluated in Stenotrophomonas maltophilia (an opportunistic pathogen and has gained increasing attention as a cause of healthcare-associated infection). S. maltophilia cannot grow well when Ara is the sole available carbon source. The induction kinetic study, optimal inducer concentration determination, and depletion experiment were performed by using a xylE gene fusion construct, pBxylE, to monitor the expression of pBBad22T in S. maltophilia. For induction survey, the expression of catechol 2,3-dioxygenase (C23O), encoded by xylE gene, continuously increases during an 8-h induced course and can be modulated by different inducer concentrations. The applied induction condition of pBBad22T in S. maltophilia is the inducer concentration ranging from 0.1% to 0.5% for an induction time of 4 h. For repression evaluation, the C23O expression is rapidly turned off within 30 min after the removal of Ara. Accordingly, the established Ara-inducible system can provide a convenient tool for the study of S. maltophilia.

  10. Risk factors for mortality in patients with Stenotrophomonas maltophilia bacteremia

    PubMed Central

    Jeon, Yong Duk; Jeong, Woo Yong; Kim, Moo Hyun; Jung, In Young; Ahn, Mi Young; Ann, Hea Won; Ahn, Jin Young; Han, Sang Hoon; Choi, Jun Yong; Song, Young Goo; Kim, June Myung; Ku, Nam Su

    2016-01-01

    Abstract Stenotrophomonas maltophilia is a nosocomial pathogen associated with high morbidity and mortality, particularly in immunocompromised or critically ill patients. In this study, we investigated the risk factors for mortality in patients with S. maltophilia bacteremia. Retrospectively, medical records from all patients with S. maltophilia bacteremia between December 2005 and 2014 at Severance Hospital, a 2000-bed tertiary care hospital in Seoul, Korea, were reviewed. Analysis was performed to identify factors associated with 28-day mortality. In total, 142 bacteremia patients were enrolled in this study. The overall 28-day mortality rate was 36.6%. Based on the univariate analysis, hematologic malignancy (P = 0.015), Sepsis-related Organ Failure Assessment (SOFA) score (P < 0.001) and the removal of a central venous catheter (CVC) (P = 0.040) were significantly related to mortality. In the intensive care unit patients, the Acute Physiology and Chronic Health Evaluation II score (P = 0.001) also had significance. Based on the multivariate analysis, the SOFA score (odds ratio [OR] = 1.323; 95% confidence interval [CI]: 1.159, 1.509; P < 0.001) and removal of the CVC (OR = 0.330; 95% CI: 0.109, 0.996; P = 0.049) were independent factors associated with mortality. Our results suggest that removing a CVC may considerably reduce mortality in patients with S. maltophilia bacteremia. PMID:27495046

  11. 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

  12. Multiple degradation pathways of phenanthrene by Stenotrophomonas maltophilia C6

    PubMed Central

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

    2013-01-01

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

  13. Adhering ability of Stenotrophomonas maltophilia is dependent on growth conditions.

    PubMed

    Zgair, Ayaid K; Chhibber, Sanjay

    2011-01-01

    The growth conditions are known to influence the bacterial adhesion to different kinds of surfaces. In the present study the adhering ability of Stenotrophomonas maltophilia, on growth in nutrient rich media (Tryptic Soy Broth (TSB)) and minimal media (Luria Bertani (LB)) was checked by viable cell count and spectrophotometric method. TSB grown S. maltophilia showed higher adhesion compared to bacteria grown in LB broth, to both biotic and abiotic surfaces. However, when bacteria were grown in LB broth supplemented with different concentrations of glucose, under aerobic conditions, the bacteria grown at lower glucose concentration (2 gm/l) showed maximum adhesion to abiotic surfaces (polystyrene microtiter plate) compared to biotic surfaces (mouse trachea, mouse tracheal mucus and HEp-2 cells line). Maximum adhesion to biotic surfaces was seen with cells grown at 4 gm/l of glucose concentration. On the contrary if the cell was grown under microaerophilic conditions maximum adhesion to abiotic and biotic surfaces was achieved with bacteria grown at 1 gm/l and 2 gm/l of glucose concentration respectively. A negative correlation was observed between glucose concentrations and pH of media, the latter declined faster under microaerophilic conditions as compared to aerobic condition.

  14. Draft Genome Sequence of Stenotrophomonas maltophilia SBo1 Isolated from Bactrocera oleae.

    PubMed

    Blow, Frances; Vontas, John; Darby, Alistair C

    2016-01-01

    Bacteria of the genus Stenotrophomonas are ubiquitous in the environment and are increasingly associated with insects. Stenotrophomonas maltophilia SBo1 was cultured from the gut of Bactrocera oleae The draft genome sequence presented here will inform future investigations into the nature of the interaction between insects and their microbiota. PMID:27660769

  15. Draft Genome Sequence of Stenotrophomonas maltophilia SBo1 Isolated from Bactrocera oleae

    PubMed Central

    Blow, Frances; Vontas, John

    2016-01-01

    Bacteria of the genus Stenotrophomonas are ubiquitous in the environment and are increasingly associated with insects. Stenotrophomonas maltophilia SBo1 was cultured from the gut of Bactrocera oleae. The draft genome sequence presented here will inform future investigations into the nature of the interaction between insects and their microbiota. PMID:27660769

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

    PubMed

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

  17. 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

  18. 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

  19. Stenotrophomonas maltophilia and Vermamoeba vermiformis relationships: bacterial multiplication and protection in amoebal-derived structures.

    PubMed

    Cateau, Estelle; Maisonneuve, Elodie; Peguilhan, Samuel; Quellard, Nathalie; Hechard, Yann; Rodier, Marie-Helene

    2014-12-01

    Stenotrophomonas maltophilia, a bacteria involved in healthcare-associated infections, can be found in hospital water systems. Other microorganisms, such as Free Living amoebae (FLA), are also at times recovered in the same environment. Amongst these protozoa, many authors have reported the presence of Vermamoeba vermiformis. We show here that this amoeba enhances S. maltophilia growth and harbors the bacteria in amoebal-derived structures after 28 days in harsh conditions. These results highlight the fact that particular attention should be paid to the presence of FLA in hospital water systems, because of their potential implication in survival and growth of pathogenic bacterial species.

  20. Stenotrophomonas maltophilia and Vermamoeba vermiformis relationships: bacterial multiplication and protection in amoebal-derived structures.

    PubMed

    Cateau, Estelle; Maisonneuve, Elodie; Peguilhan, Samuel; Quellard, Nathalie; Hechard, Yann; Rodier, Marie-Helene

    2014-12-01

    Stenotrophomonas maltophilia, a bacteria involved in healthcare-associated infections, can be found in hospital water systems. Other microorganisms, such as Free Living amoebae (FLA), are also at times recovered in the same environment. Amongst these protozoa, many authors have reported the presence of Vermamoeba vermiformis. We show here that this amoeba enhances S. maltophilia growth and harbors the bacteria in amoebal-derived structures after 28 days in harsh conditions. These results highlight the fact that particular attention should be paid to the presence of FLA in hospital water systems, because of their potential implication in survival and growth of pathogenic bacterial species. PMID:25463386

  1. Class 1 Integrons Increase Trimethoprim-Sulfamethoxazole MICs against Epidemiologically Unrelated Stenotrophomonas maltophilia Isolates

    PubMed Central

    Barbolla, Raquel; Catalano, Mariana; Orman, Betina E.; Famiglietti, Angela; Vay, Carlos; Smayevsky, Jorgelina; Centrón, Daniela; Piñeiro, Silvia A.

    2004-01-01

    Twenty-five plasmid-specified antimicrobial resistance determinants common to gram-negative bacilli from nosocomial infection were investigated from 31 Stenotrophomonas maltophilia isolates. Twenty-four clones were identified by pulsed-field gel electrophoresis, and in three clones that exhibited an increased trimethoprim-sulfamethoxazole MIC, the sul1 determinant was found. These results support not only the higher spread of class 1 integrons compared to other mechanisms but also the potential limitation of using trimethoprim-sulfamethoxazole for therapy of severe S. maltophilia infections. PMID:14742234

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

    PubMed Central

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

    2016-01-01

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

  3. Successful Treatment of Bloodstream Infection Due to Metallo-β-Lactamase-Producing Stenotrophomonas maltophilia in a Renal Transplant Patient.

    PubMed

    Mojica, Maria F; Ouellette, Christopher P; Leber, Amy; Becknell, M Brian; Ardura, Monica I; Perez, Federico; Shimamura, Masako; Bonomo, Robert A; Aitken, Samuel L; Shelburne, Samuel A

    2016-09-01

    Stenotrophomonas maltophilia is an emerging multidrug-resistant (MDR) opportunistic pathogen for which new antibiotic options are urgently needed. We report our clinical experience treating a 19-year-old renal transplant recipient who developed prolonged bacteremia due to metallo-β-lactamase-producing S. maltophilia refractory to conventional treatment. The infection recurred despite a prolonged course of colistimethate sodium (colistin) but resolved with the use of a novel drug combination with clinical efficacy against the patient's S. maltophilia isolate. PMID:27551008

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

    PubMed Central

    2014-01-01

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

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

    PubMed Central

    White, Corin V.; Darby, Brian J.; Breeden, Robert J.

    2015-01-01

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

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

    PubMed

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

    2015-12-07

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

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

    PubMed

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

    2016-02-01

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

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

    PubMed

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

    2014-11-01

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

  9. A Secreted Ankyrin-Repeat Protein from Clinical Stenotrophomonas maltophilia Isolates Disrupts Actin Cytoskeletal Structure.

    PubMed

    MacDonald, Logan C; O'Keefe, Sean; Parnes, Mei-Fan; MacDonald, Hanlon; Stretz, Lindsey; Templer, Suzanne J; Wong, Emily L; Berger, Bryan W

    2016-01-01

    Stenotrophomonas maltophilia is an emerging, multidrug-resistant pathogen of increasing importance for the immunocompromised, including cystic fibrosis patients. Despite its significance as an emerging pathogen, relatively little is known regarding the specific factors and mechanisms that contribute to its pathogenicity. We identify and characterize a putative ankyrin-repeat protein (Smlt3054) unique to clinical S. maltophilia isolates that binds F-actin in vitro and co-localizes with actin in transfected HEK293a cells. Smlt3054 is endogenously expressed and secreted from clinical S. maltophilia isolates, but not an environmental isolate (R551-3). The in vitro binding of Smlt3054 to F-actin resulted in a thickening of the filaments as observed by TEM. Ectopic expression of Smlt3054-GFP exhibits strong co-localization with F-actin, with distinct, retrograde F-actin waves specifically associated with Smlt3054 in individual cells as well as formation of dense, internal inclusions at the expense of retrograde F-actin waves. Collectively, our results point to an interaction between Smlt3054 and F-actin. Furthermore, as a potentially secreted protein unique to clinical S. maltophilia isolates, Smlt3054 may serve as a starting point for understanding the mechanisms by which S. maltophilia has become an emergent pathogen. PMID:27622948

  10. Effects of Fluoroquinolones and Azithromycin on Biofilm Formation of Stenotrophomonas maltophilia.

    PubMed

    Wang, Aihua; Wang, Qinqin; Kudinha, Timothy; Xiao, Shunian; Zhuo, Chao

    2016-01-01

    Stenotrophomonas maltophilia is an opportunistic pathogen that causes respiratory and urinary tract infections, as well as wound infections in immunocompromised patients. This pathogen is difficult to treat due to increased resistance to many antimicrobial agents. We investigated the in vitro biofilm formation of S. maltophilia, including effects of fluoroquinolones (FQs) and azithromycin on biofilm formation. The organism initiated attachment to polystyrene surfaces after a 4 h incubation period, and reached maximal growth at 18-24 h. In the presence of FQs (moxifloxacin, levofloxacin or ciprofloxacin), the biofilm biomass was significantly reduced (P < 0.05). A lower concentration of moxifloxacin (10 μg/mL) exhibited a better inhibiting effect on biofilm formation than 100 μg/mL (P < 0.01), but with no difference in effect compared to the 50 μg/mL concentration (P > 0.05). However, the inhibitory effects of 10 μg/mL of levofloxacin or ciprofloxacin were slightly less pronounced than those of the higher concentrations. A combination of azithromycin and FQs significantly reduced the biofilm inhibiting effect on S. maltophilia preformed biofilms compared to azithromycin or FQs alone. We conclude that early use of clinically acceptable concentrations of FQs, especially moxifloxacin (10 μg/mL), may possibly inhibit biofilm formation by S. maltophilia. Our study provides an experimental basis for a possible optimal treatment strategy for S. maltophilia biofilm-related infections.

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  13. Intensive care unit-acquired Stenotrophomonas maltophilia: incidence, risk factors, and outcome

    PubMed Central

    Nseir, Saad; Di Pompeo, Christophe; Brisson, Hélène; Dewavrin, Florent; Tissier, Stéphanie; Diarra, Maimouna; Boulo, Marie; Durocher, Alain

    2006-01-01

    Introduction The aim of this study was to determine incidence, risk factors, and impact on outcome of intensive care unit (ICU)-acquired Stenotrophomonas maltophilia. Methods This prospective observational case-control study, which was a part of a cohort study, was conducted in a 30-bed ICU during a three year period. All immunocompetent patients hospitalised >48 hours were eligible. Patients with non-fermenting Gram-negative bacilli (NF-GNB) at ICU admission were excluded. Patients without ICU-acquired S. maltophilia who developed an ICU-acquired NF-GNB other than S. maltophilia were also excluded. Screening (tracheal aspirate and skin, anal, and nasal swabs) for NF-GNB was performed in all patients at ICU admission and weekly. Univariate and multivariate analyses were performed to determine risk factors for ICU-acquired S. maltophilia and for ICU mortality. Results Thirty-eight (2%) patients developed an S. maltophilia ICU-acquired colonisation and/or infection and were all successfully matched with 76 controls. Chronic obstructive pulmonary disease (COPD) and duration of antibiotic treatment (odds ratio [OR] [95% confidence interval (CI)] = 9.4 [3 to 29], p < 0.001, and 1.4 [1 to 2.3], p = 0.001, respectively) were independently associated with ICU-acquired S. maltophilia. Mortality rate (60% versus 40%, OR [95% CI] = 1.3 [1 to 1.7, p = 0.037]), duration of mechanical ventilation (23 ± 16 versus 7 ± 11 days, p < 0.001), and duration of ICU stay (29 ± 21 versus 15 ± 17 days, p < 0.001) were significantly higher in cases than in controls. In addition, ICU-acquired infection related to S. maltophilia was independently associated with ICU mortality (OR [95% CI] = 2.8 [1 to 7.7], p = 0.044). Conclusion COPD and duration of antibiotic treatment are independent risk factors for ICU-acquired S. maltophilia. ICU-acquired S. maltophilia is associated with increased morbidity and mortality rates. ICU-acquired infection related to S. maltophilia is an independent risk

  14. Genomic Potential of Stenotrophomonas maltophilia in Bioremediation with an Assessment of Its Multifaceted Role in Our Environment

    PubMed Central

    Mukherjee, Piyali; Roy, Pranab

    2016-01-01

    The gram negative bacterium Stenotrophomonas is rapidly evolving as a nosocomial pathogen in immuno-compromised patients. Treatment of Stenotrophomonas maltophilia infections is problematic because of their increasing resistance to multiple antibiotics. This article aims to review the multi-disciplinary role of Stenotrophomonas in our environment with special focus on their metabolic and genetic potential in relation to bioremediation and phytoremediation. Current and emerging treatments and diagnosis for patients infected with S. maltophilia are discussed besides their capability of production of novel bioactive compounds. The plant growth promoting characteristics of this bacterium has been considered with special reference to secondary metabolite production. Nano-particle synthesis by Stenotrophomonas has also been reviewed in addition to their applications as effective biocontrol agents in plant and animal pathogenesis. PMID:27446008

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

    NASA Astrophysics Data System (ADS)

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

    2009-06-01

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

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

    SciTech Connect

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

    2009-06-08

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

  17. Molecular characterization and ultrastructure of a new amoeba endoparasite belonging to the Stenotrophomonas maltophilia complex.

    PubMed

    Corsaro, Daniele; Müller, Karl-Dieter; Michel, Rolf

    2013-04-01

    Naegleria and Acanthamoeba spp. were recovered from biofilm of a flushing cistern in a lavatory and both were found to be infected by rod-shaped bacteria enclosed within a vacuole. These intracellular bacteria behave like parasites, causing lysis of host amoebae. The bacteria proved unculturable on bacteriological media, and but could be maintained as endocytobionts within Acanthamoeba on agar plates. A marked differential host preference was observed in co-culture assays with various strains of amoebae. Molecular phylogenetic analyses performed on almost complete 16S rDNA sequences showed that the bacteria emerged as an atypical rapidly-evolving strain within the Stenotrophomonas maltophilia complex (Gamma-Proteobacteria, Xanthomonadales).

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

    PubMed Central

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

    2016-01-01

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

  19. Effects of Fluoroquinolones and Azithromycin on Biofilm Formation of Stenotrophomonas maltophilia

    PubMed Central

    Wang, Aihua; Wang, Qinqin; Kudinha, Timothy; Xiao, Shunian; Zhuo, Chao

    2016-01-01

    Stenotrophomonas maltophilia is an opportunistic pathogen that causes respiratory and urinary tract infections, as well as wound infections in immunocompromised patients. This pathogen is difficult to treat due to increased resistance to many antimicrobial agents. We investigated the in vitro biofilm formation of S. maltophilia, including effects of fluoroquinolones (FQs) and azithromycin on biofilm formation. The organism initiated attachment to polystyrene surfaces after a 4 h incubation period, and reached maximal growth at 18–24 h. In the presence of FQs (moxifloxacin, levofloxacin or ciprofloxacin), the biofilm biomass was significantly reduced (P < 0.05). A lower concentration of moxifloxacin (10 μg/mL) exhibited a better inhibiting effect on biofilm formation than 100 μg/mL (P < 0.01), but with no difference in effect compared to the 50 μg/mL concentration (P > 0.05). However, the inhibitory effects of 10 μg/mL of levofloxacin or ciprofloxacin were slightly less pronounced than those of the higher concentrations. A combination of azithromycin and FQs significantly reduced the biofilm inhibiting effect on S. maltophilia preformed biofilms compared to azithromycin or FQs alone. We conclude that early use of clinically acceptable concentrations of FQs, especially moxifloxacin (10 μg/mL), may possibly inhibit biofilm formation by S. maltophilia. Our study provides an experimental basis for a possible optimal treatment strategy for S. maltophilia biofilm-related infections. PMID:27405358

  20. 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.

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

    PubMed Central

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

    2015-01-01

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

  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

    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.

  4. 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

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

    PubMed Central

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

    2011-01-01

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

  6. 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 β-lactams. Despite the increasingly reported drug resistance, trimethoprim-sulfamethoxazole is still the drug of choice. However, the organism is still susceptible to ticarcillin-clavulanic acid, tigecycline, fluoroquinolones, polymyxin-B, and rifampicin. Genetic factors play a significant role not only in evolution of drug resistance but also in virulence of the organism. The outcome of patients having S. maltophilia infections can be improved by: using various combinations of novel therapeutic agents and aerosolized aminoglycosides or colistin, prompt administration of in vitro active antibiotics, removal of possible sources of infection such as infected indwelling intravascular catheters, and application of strict infection control measures. PMID:25202682

  7. Enhanced degradation of TNT by genome-shuffled Stenotrophomonas maltophilia OK-5.

    PubMed

    Lee, Bheong-Uk; Cho, Yun-Seok; Park, Sung-Chul; Oh, Kye-Heon

    2009-09-01

    In this study, the enhanced degradation of TNT using cultures of genome-shuffled Stenotrophomonas maltophilia OK-5 mt-3 has been examined and the proteome of shuffled strain was compared to the wild-type OK-5 strain. Genome shuffling of S. maltophilia OK-5 was used to achieve a rapid enhancement of TNT degradation. The initial mutant population was generated by NTG treatment and UV irradiation. The wild-type OK-5 strain was able to degrade 0.2 mM TNT within 6 days, yet barely tolerated 0.5 mM TNT while the shuffled OK-5 mt-3 was capable of completely degrading 0.5 mM TNT within 8 days, and 1.2 mM within 24 days. The proteomic analysis of the shuffled OK-5 mt-3 demonstrated the changes in the expression levels of certain proteins compared to wild-type OK-5. These results provide clues for understanding TNT tolerance and improved TNT degradation by shuffled S. maltophilia OK-5 mt-3 and have possible applications in the processing of industrial waste containing relatively high TNT concentrations.

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

    PubMed

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

    2016-05-01

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

  9. 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

  10. 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 β-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-β-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-β-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

  11. 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 (q(max)), half-saturation constant (K(S)) and inhibition constant (K(i)) 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.

  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 Highly Thermostable Xylanase from Stenotrophomonas maltophilia: Purification and Partial Characterization

    PubMed Central

    Kumar, Sharad; Singh, Sudheer Kumar

    2013-01-01

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

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

    PubMed Central

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

    1997-01-01

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

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

    PubMed

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

    2015-01-01

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

  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 efflux pumps’ overexpression. Our objective is to get information on novel mechanisms of S. maltophilia quinolone resistance. For this purpose, a transposon-insertion mutant library was obtained in S. maltophilia D457. One mutant presenting reduced susceptibility to nalidixic acid was selected. Inverse PCR showed that the inactivated gene encodes RNase G. Complementation of the mutant with wild-type RNase G allele restored the susceptibility to quinolones. Transcriptomic and real-time RT-PCR analyses showed that several genes encoding heat-shock response proteins were expressed at higher levels in the RNase defective mutant than in the wild-type strain. In agreement with this situation, heat-shock reduces the S. maltophilia susceptibility to quinolone. We can then conclude that the inactivation of the RNase G reduces the susceptibility of S. maltophilia to quinolones, most likely by regulating the expression of heat-shock response genes. Heat-shock induces a transient phenotype of quinolone resistance in S. maltophilia. PMID:26539164

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

    PubMed Central

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

    2009-01-01

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

  18. 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

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

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

    PubMed

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

    2015-08-14

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

  1. Stenotrophomonas maltophilia Phenotypic and Genotypic Diversity during a 10-year Colonization in the Lungs of a Cystic Fibrosis Patient

    PubMed Central

    Pompilio, Arianna; Crocetta, Valentina; Ghosh, Dipankar; Chakrabarti, Malabika; Gherardi, Giovanni; Vitali, Luca Agostino; Fiscarelli, Ersilia; Di Bonaventura, Giovanni

    2016-01-01

    The present study was carried out to understand the adaptive strategies developed by Stenotrophomonas maltophilia for chronic colonization of the cystic fibrosis (CF) lung. For this purpose, 13 temporally isolated strains from a single CF patient chronically infected over a 10-year period were systematically characterized for growth rate, biofilm formation, motility, mutation frequencies, antibiotic resistance, and pathogenicity. Pulsed-field gel electrophoresis (PFGE) showed over time the presence of two distinct groups, each consisting of two different pulsotypes. The pattern of evolution followed by S. maltophilia was dependent on pulsotype considered, with strains belonging to pulsotype 1.1 resulting to be the most adapted, being significantly changed in all traits considered. Generally, S. maltophilia adaptation to CF lung leads to increased growth rate and antibiotic resistance, whereas both in vivo and in vitro pathogenicity as well as biofilm formation were decreased. Overall, our results show for the first time that S. maltophilia can successfully adapt to a highly stressful environment such as CF lung by paying a “biological cost,” as suggested by the presence of relevant genotypic and phenotypic heterogeneity within bacterial population. S. maltophilia populations are, therefore, significantly complex and dynamic being able to fluctuate rapidly under changing selective pressures. PMID:27746770

  2. 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.

  3. Biological Control of Bipolaris sorokiniana on Tall Fescue by Stenotrophomonas maltophilia Strain C3.

    PubMed

    Zhang, Z; Yuen, G Y

    1999-09-01

    ABSTRACT Stenotrophomonas maltophilia strain C3 was evaluated for control of leaf spot on tall fescue (Festuca arundinacea) caused by Bipolaris sorokiniana. In growth chamber experiments, C3 inhibited conidial germination on leaf surfaces and reduced lesion frequency and percent diseased leaf area compared with nontreated controls. The amount of leaf spot suppression was related to the C3 dose applied. The highest dose tested, 10(9) CFU/ml, prevented nearly all B. sorokiniana conidia from germinating on treated leaf surfaces and provided nearly complete suppression of lesion development. When colloidal chitin was added to C3 cell suspensions of 10(7) or 10(8) CFU/ml, biocontrol efficacy was significantly increased over C3 applied alone, whereas addition of chitin to a C3 cell suspension of 10(9) CFU/ml had no effect. In field experiments, application of C3 to tall fescue turf resulted in significant reductions in infection frequency and disease severity compared with nontreated controls. Strain C3 applied at 10(9) CFU/ml was more effective than C3 applied at 10(7) CFU/ml, and amendment of the lower dose with colloidal chitin enhanced its efficacy. Populations sizes of C3 established on foliage in a growth chamber and in the field were directly related to dose applied. Chitin amendments did not affect C3 population size.

  4. Biotransformation of tetracycline by a novel bacterial strain Stenotrophomonas maltophilia DT1.

    PubMed

    Leng, Yifei; Bao, Jianguo; Chang, Gaofeng; Zheng, Han; Li, Xingxing; Du, Jiangkun; Snow, Daniel; Li, Xu

    2016-11-15

    Although several abiotic processes have been reported that can transform antibiotics, little is known about whether and how microbiological processes may degrade antibiotics in the environment. This work isolated one tetracycline degrading bacterial strain, Stenotrophomonas maltophilia strain DT1, and characterized the biotransformation of tetracycline by DT1 under various environmental conditions. The biotransformation rate was the highest when the initial pH was 9 and the reaction temperature was at 30°C, and can be described using the Michaelis-Menten model under different initial tetracycline concentrations. When additional substrate was present, the substrate that caused increased biomass resulted in a decreased biotransformation rate of tetracycline. According to disk diffusion tests, the biotransformation products of tetracycline had lower antibiotic potency than the parent compound. Six possible biotransformation products were identified, and a potential biotransformation pathway was proposed that included sequential removal of N-methyl, carbonyl, and amine function groups. Results from this study can lead to better estimation of the fate and transport of antibiotics in the environment and has the potential to be utilized in designing engineering processes to remove tetracycline from water and soil. PMID:27420384

  5. 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

  6. Comparative effects of wild type Stenotrophomonas maltophilia and its indole acetic acid-deficient mutants on wheat.

    PubMed

    Hassan, T U; Bano, A

    2016-09-01

    The present investigation evaluated the role of Stenotrophomonas maltophilia and its IAA-deficient mutant on soil health and plant growth under salinity stress in the presence of tryptophan. In the first phase, S. maltophilia isolated from roots of the halo- phytic herb, Cenchrus ciliaris was used as bio-inoculant on wheat grown in saline sodic soil. A field experiment was conducted at Soil Salinity Research Institute during 2010-2011. Treatments included seed inoculation with S. maltophilia with or without tryptophan; uninoculated untreated plants were taken as control. An aqueous solution of tryptophan was added to rhizosphere soil at 1 μg l(_1) after seed germination. Inoculation with S. maltophilia significantly increased soil organic matter, enhanced (20-30%) availability of P, K, Ca and NO3 -N and decreased Na content and electrical conductivity of rhizosphere soil. Plant height, fresh weight, proline and phytohormone content of leaves were increased 30-40% over the control. Activities of superoxide dismutase (SOD) and peroxidase (POD) were 40-50% higher than control. Addition of tryptophan further augmented (10-15%) growth parameters, whereas NO3 -N, P, K and Ca content, proline content and SOD and POD increased 20-30%. In a second phase, indoleacetic acid (IAA)-deficient mutants of S. maltophilia were constructed and evaluated for conversion of tryptophan to IAA at the University of Calgary, Canada, during 2013-2014. About 1800 trans-conjugants were constructed that were unable to produce IAA in the presence of tryptophan. The results suggest that tryptophan assisted S. maltophilia in the amelioration of salt stress, and that IAA played positive role in induction of salt tolerance. PMID:27263526

  7. 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

  8. Chitinases from the Plant Disease Biocontrol Agent, Stenotrophomonas maltophilia C3.

    PubMed

    Zhang, Z; Yuen, G Y; Sarath, G; Penheiter, A R

    2001-02-01

    ABSTRACT Stenotrophomonas maltophilia strain C3, a biocontrol agent of Bipolaris sorokiniana in turfgrass, produced chitinases in broth media containing chitin. Chitinases were partially purified from culture fluid by ammonium sulfate precipitation and chitin affinity chromatography. The chromatography fraction with the highest specific chitinase activity was inhibitory to conidial germination and germ-tube elongation of B. sorokiniana, but it was less inhibitory than the protein fraction or the raw culture filtrate. The fraction exhibited strong exochitinase and weak endo-chitinase activity. Optimum temperature and pH for chitinase activity were 45 to 50 degrees C and 4.5 to 5.0, respectively. Chitinase activity was inhibited by Hg(2+) and Fe(3+), but not by other metal ions or enzyme inhibitors. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the chromatography fraction revealed the presence of five protein bands of 25, 32, 48, 65, and 75 kDa. Partial amino acid sequences of the 32-, 65-, and 75-kDa proteins indicated that they are homologous to known bacterial chitinases. There was no homology found in the partial amino acid sequences of the 25- and 48-kDa proteins to any known chitinases. Five chitinase-active proteins were detected in the protein and chromatography fractions by activity gels, but when each protein was extracted and re-electrophoresed separately under denaturing conditions, only 32- or 48-kDa proteins were revealed. It was concluded that strain C3 produces at least two chitinases that are antifungal.

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

    PubMed Central

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

    2014-01-01

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

  10. 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

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

    PubMed Central

    Damania, Ashish

    2016-01-01

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

  12. 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

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

    PubMed

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

    2014-08-01

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

  14. 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

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

    PubMed

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

    2014-08-01

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

  16. [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).

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

    PubMed Central

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

    1995-01-01

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

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

    PubMed

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

    2015-03-01

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

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

    PubMed

    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

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

    PubMed

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

    2016-03-01

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

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

    PubMed

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

    2016-03-01

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

  2. Predictive analysis of transmissible quinolone resistance indicates Stenotrophomonas maltophilia as a potential source of a novel family of Qnr determinants

    PubMed Central

    Sánchez, María B; Hernández, Alvaro; Rodríguez-Martínez, José M; Martínez-Martínez, Luis; Martínez, José L

    2008-01-01

    Background Predicting antibiotic resistance before it emerges at clinical settings constitutes a novel approach for preventing and fighting resistance of bacterial pathogens. To analyse the possibility that novel plasmid-encoded quinolone resistance determinants (Qnr) can emerge and disseminate among bacterial pathogens, we searched the presence of those elements in nearly 1000 bacterial genomes and metagenomes. Results We have found a number of novel potential qnr genes in the chromosomes of aquatic bacteria and in metagenomes from marine organisms. Functional studies of the Stenotrophomonas maltophilia Smqnr gene show that plasmid-encoded SmQnr confers quinolone resistance upon its expression in a heterologous host. Conclusion Altogether, the data presented in our work support the notion that predictive studies on antibiotic resistance are feasible, using currently available information on bacterial genomes and with the aid of bioinformatic and functional tools. Our results confirm that aquatic bacteria can be the origin of plasmid-encoded Qnr, and highlight the potential role of S. maltophilia as a source of novel Qnr determinants. PMID:18793450

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

    PubMed

    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

  4. 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

  5. Influence of co-existed benzo[a]pyrene and copper on the cellular characteristics of Stenotrophomonas maltophilia during biodegradation and transformation.

    PubMed

    Chen, Shuona; Yin, Hua; Ye, Jinshao; Peng, Hui; Liu, Zehua; Dang, Zhi; Chang, Jingjing

    2014-04-01

    Microbial remediation has been proposed as a promising technique to remove pollutions, however, its application has been hindered by the lack of understanding the mechanisms involved in contaminants conversion and the influence of pollutants on cellular characteristics. To address this problem, biodegradation and transformation of BaP-Cu(II) by Stenotrophomonas maltophilia, along with interactions of these pollutants with microbial cells through FCM assay were investigated. The results indicated that BaP and Cu(II) were rapidly removed by S. maltophilia on the 1st d, but only less than 10% BaP was broken down due to temporary store in cells, instead of being decomposed immediately. The key ATP enzymes in cells were then activated by BaP to promote bacteria to further decompose BaP. Stimulation of co-existed contaminants strengthened cell membrane permeability and altered cell structure, but a higher esterase activity and DNA in cells of S. maltophilia were still retained.

  6. Topoisomerase II and IV quinolone resistance-determining regions in Stenotrophomonas maltophilia clinical isolates with different levels of quinolone susceptibility.

    PubMed

    Valdezate, Sylvia; Vindel, Ana; Echeita, Aurora; Baquero, Fernando; Cantó, Rafael

    2002-03-01

    The quinolone resistance-determining regions (QRDRs) of topoisomerase II and IV genes from Stenotrophomonas maltophilia ATCC 13637 were sequenced and compared with the corresponding regions of 32 unrelated S. maltophilia clinical strains for which ciprofloxacin MICs ranged from 0.1 to 64 microg/ml. GyrA (Leu-55 to Gln-155, Escherichia coli numbering), GyrB (Met-391 to Phe-513), ParC (Ile-34 to Arg-124), and ParE (Leu-396 to Leu-567) fragments from strain ATCC 13637 showed high degrees of identity to the corresponding regions from the phytopathogen Xylella fastidiosa, with the degrees of identity ranging from 85.0 to 93.5%. Lower degrees of identity to the corresponding regions from Pseudomonas aeruginosa (70.9 to 88.6%) and E. coli (73.0 to 88.6%) were observed. Amino acid changes were present in GyrA fragments from 9 of the 32 strains at positions 70, 85, 90, 103, 112, 113, 119, and 124; but there was no consistent relation to higher ciprofloxacin MICs. The absence of changes at positions 83 and 87, commonly involved in quinolone resistance in gram-negative bacteria, was unexpected. The GyrB sequences were identical in all strains, and only one strain (ciprofloxacin MIC, 16 microg/ml) showed a ParC amino acid change (Ser-80-->Arg). In contrast, a high frequency (16 of 32 strains) of amino acid replacements was present in ParE. The frequencies of alterations at positions 437, 465, 477, and 485 were higher (P < 0.05) in strains from cystic fibrosis patients, but these changes were not linked with high ciprofloxacin MICs. An efflux phenotype, screened by the detection of decreases of at least twofold doubling dilutions of the ciprofloxacin MIC in the presence of carbonyl cyanide m-chlorophenylhydrazone (0.5 microg/ml) or reserpine (10 microg/ml), was suspected in seven strains. These results suggest that topoisomerases II and IV may not be the primary targets involved in quinolone resistance in S. maltophilia.

  7. Topoisomerase II and IV Quinolone Resistance-Determining Regions in Stenotrophomonas maltophilia Clinical Isolates with Different Levels of Quinolone Susceptibility

    PubMed Central

    Valdezate, Sylvia; Vindel, Ana; Echeita, Aurora; Baquero, Fernando; Cantó, Rafael

    2002-01-01

    The quinolone resistance-determining regions (QRDRs) of topoisomerase II and IV genes from Stenotrophomonas maltophilia ATCC 13637 were sequenced and compared with the corresponding regions of 32 unrelated S. maltophilia clinical strains for which ciprofloxacin MICs ranged from 0.1 to 64 μg/ml. GyrA (Leu-55 to Gln-155, Escherichia coli numbering), GyrB (Met-391 to Phe-513), ParC (Ile-34 to Arg-124), and ParE (Leu-396 to Leu-567) fragments from strain ATCC 13637 showed high degrees of identity to the corresponding regions from the phytopathogen Xylella fastidiosa, with the degrees of identity ranging from 85.0 to 93.5%. Lower degrees of identity to the corresponding regions from Pseudomonas aeruginosa (70.9 to 88.6%) and E. coli (73.0 to 88.6%) were observed. Amino acid changes were present in GyrA fragments from 9 of the 32 strains at positions 70, 85, 90, 103, 112, 113, 119, and 124; but there was no consistent relation to higher ciprofloxacin MICs. The absence of changes at positions 83 and 87, commonly involved in quinolone resistance in gram-negative bacteria, was unexpected. The GyrB sequences were identical in all strains, and only one strain (ciprofloxacin MIC, 16 μg/ml) showed a ParC amino acid change (Ser-80→Arg). In contrast, a high frequency (16 of 32 strains) of amino acid replacements was present in ParE. The frequencies of alterations at positions 437, 465, 477, and 485 were higher (P < 0.05) in strains from cystic fibrosis patients, but these changes were not linked with high ciprofloxacin MICs. An efflux phenotype, screened by the detection of decreases of at least twofold doubling dilutions of the ciprofloxacin MIC in the presence of carbonyl cyanide m-chlorophenylhydrazone (0.5 μg/ml) or reserpine (10 μg/ml), was suspected in seven strains. These results suggest that topoisomerases II and IV may not be the primary targets involved in quinolone resistance in S. maltophilia. PMID:11850246

  8. Persistent Organic Pollutants Induced Protein Expression and Immunocrossreactivity by Stenotrophomonas maltophilia PM102: A Prospective Bioremediating Candidate

    PubMed Central

    Mukherjee, Piyali; Roy, Pranab

    2013-01-01

    A novel bacterium capable of growth on trichloroethylene as the sole carbon source was identified as Stenotrophomonas maltophilia PM102 by 16S rDNA sequencing (accession number of NCBI GenBank: JQ797560). In this paper, we report the growth pattern, TCE degradation, and total proteome of this bacterium in presence of various other carbon sources: toluene, phenol, glucose, chloroform, and benzene. TCE degradation was comparatively enhanced in presence of benzene. Densitometric analysis of the intracellular protein profile revealed four proteins of 78.6, 35.14, 26.2, and 20.47 kDa while the extracellular protein profile revealed two distinct bands at 14 kDa and 11 kDa that were induced by TCE, benzene, toluene, and chloroform but absent in the glucose lane. A rabbit was immunised with the total protein extracted from the bacteria grown in 0.2% TCE + 0.2% peptone. Antibody preadsorbed on proteins from peptone grown PM102 cells reacted with a single protein of 35.14 kDa (analysed by MALDI-TOF-mass-spectrometry) from TCE, benzene, toluene, or chloroform grown cells. No reaction was seen for proteins of PM102 grown with glucose. The PM102 strain was immobilised in calcium alginate beads, and TCE degradation by immobilised cells was almost double of that by free cells. The beads could be reused 8 times. PMID:23878815

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

    PubMed

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

    2008-01-01

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

  10. Genomic characterization and integrative properties of phiSMA6 and phiSMA7, two novel filamentous bacteriophages of Stenotrophomonas maltophilia.

    PubMed

    Petrova, Mayya; Shcherbatova, Natalya; Kurakov, Anton; Mindlin, Sofia

    2014-06-01

    Two novel filamentous phages, phiSMA6 and phiSMA7, were isolated from Stenotrophomonas maltophilia environmental strain Khak84. We identified and annotated 11 potential open reading frames in each phage. While the overall layout of the functional gene groups of both phages was similar to that of the known filamentous phages, they differed from them in their molecular structure. The genome of phiSMA6 is a mosaic that evolved by acquiring genes from at least three different filamentous S. maltophilia phages and one Xanthomonas campestris phage related to Cf1. In the phiSMA6 genome, a gene similar to the bacterial gene encoding the mating pair formation protein trbP was also found. We showed that phiSMA6 possesses lysogenic properties and upon induction produces high-titer lysates. The genome of phiSMA7 possesses a unique structure and was found to be closely related to a prophage present in the chromosome of the completely sequenced S. maltophilia clinical strain D457. We suggest that the other three filamentous phages of S. maltophilia described previously also have the capacity to integrate into the genome of their bacterial host. PMID:24327089

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

    PubMed Central

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

    2014-01-01

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

  12. 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

  13. The Role of Chitinase Production by Stenotrophomonas maltophilia Strain C3 in Biological Control of Bipolaris sorokiniana.

    PubMed

    Zhang, Z; Yuen, G Y

    2000-04-01

    ABSTRACT The role of chitinase production by Stenotrophomonas maltophilia strain C3 in biological control of leaf spot on tall fescue (Festuca arundinacea), caused by Bipolaris sorokiniana, was investigated in vitro and in vivo. The filtrate of a broth culture of C3, with chitin as the carbon source, was separated into fractions. A high molecular-weight fraction (>8 kDa) was chitinolytic and more inhibitory than a low-molecular-weight, nonchitinolytic fraction to conidial germination and hyphal growth by B. sorokiniana and to leaf spot development. A protein fraction derived by ammonium sulfate precipitation and a chitinase fraction purified by chitin affinity chromatography also were chitinolytic and highly antifungal. The chitinolytic fractions caused swelling and vacuolation of conidia and discoloration, malformation, and degradation of germ tubes. When boiled, the chitinolytic fractions lost chitinase activity along with most of the antifungal properties. Two chitinase-deficient and two chitinase-reduced mutants of C3 were compared with the wild-type strain for inhibition of germination of B. sorokiniana conidia on tall fescue leaves and for suppression of leaf spot development in vivo. The mutants exhibited reduced antifungal activity and biocontrol efficacy, but did not lose all biocontrol activity. An aqueous extract of leaves colonized by wild-type C3 had higher chitinase activity than that of noncolonized leaves and was inhibitory to conidial germination. The addition of chitin to leaves along with the wild-type strain increased both chitinase and antifungal activity. The chitinase activity level of extracts from leaves colonized by a chitinase-deficient mutant of C3, with and without added chitin, was no higher than the background, and the extracts lacked antifungal activity. Chitinolysis appears to be one mechanism of biological control by strain C3, and it functions in concert with other mechanisms.

  14. Stenotrophomonas maltophilia SeITE02, a New Bacterial Strain Suitable for Bioremediation of Selenite-Contaminated Environmental Matrices▿

    PubMed Central

    Antonioli, Paolo; Lampis, Silvia; Chesini, Irene; Vallini, Giovanni; Rinalducci, Sara; Zolla, Lello; Righetti, Pier Giorgio

    2007-01-01

    Biochemical and proteomic tools have been utilized for investigating the mechanism of action of a new Stenotrophomonas maltophilia strain (SeITE02), a gammaproteobacterium capable of resistance to high concentrations of selenite [SeO32−, Se(IV)], reducing it to nontoxic elemental selenium under aerobic conditions; this strain was previously isolated from a selenite-contaminated mining soil. Biochemical analysis demonstrated that (i) nitrite reductase does not seem to take part in the process of selenite reduction by the bacterial strain SeITE02, although its involvement in this process had been hypothesized in other cases; (ii) nitrite strongly interferes with selenite removal when the two oxyanions (NO2− and SeO32−) are simultaneously present, suggesting that the two reduction/detoxification pathways share a common enzymatic step, probably at the level of cellular transport; (iii) in vitro, selenite reduction does not take place in the membrane or periplasmic fractions but only in the cytoplasm, where maximum activity is exhibited at pH 6.0 in the presence of NADPH; and (iv) glutathione is involved in the selenite reduction mechanism, since inhibition of its synthesis leads to a considerable delay in the onset of reduction. As far as the proteomic findings are concerned, the evidence was reached that 0.2 mM selenite and 16 mM nitrite, when added to the culture medium, caused a significant modulation (ca. 10%, i.e., 96 and 85 protein zones, respectively) of the total proteins visualized in the respective two-dimensional maps. These spots were identified by mass spectrometry analysis and were found to belong to the following functional classes: nucleotide synthesis and metabolism, damaged-protein catabolism, protein and amino acid metabolism, and carbohydrate metabolism along with DNA-related proteins and proteins involved in cell division, oxidative stress, and cell wall synthesis. PMID:17827320

  15. A linkage between SmeIJK efflux pump, cell envelope integrity, and σE-mediated envelope stress response in Stenotrophomonas maltophilia.

    PubMed

    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 σE-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 σE-mediated ESR. Moreover, the expression of smeIJK was further induced by sub-lethal concentrations of MDAs or surfactants in an σE-dependent manner. These data collectively suggested an alternative physiological role of smeIJK in cell envelope integrity maintenance and σE-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 σE-mediated ESR in S. maltophilia. PMID:25390933

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

    PubMed Central

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

    2016-01-01

    The Gram-negative bacterium Stenotrophomonas maltophilia lives in diverse ecological niches. As a result of its formidable capabilities of forming biofilm and its resistance to multiple antibiotic agents, the bacterium is also a nosocomial pathogen of serious threat to the health of patients whose immune systems are suppressed or compromised. Besides the histidine kinase RpfC, the two-component signal transduction system (TCS), which is the canonical regulatory machinery used by most bacterial pathogens, has never been experimentally investigated in S. maltophilia. Here, we annotated 62 putative histidine kinase genes in the S. maltophilia genome and successfully obtained 51 mutants by systematical insertional inactivation. Phenotypic characterization identified a series of mutants with deficiencies in bacterial growth, swimming motility, and biofilm development. A TCS, named here BfmA-BfmK (Smlt4209-Smlt4208), was genetically confirmed to regulate biofilm formation in S. maltophilia. Together with interacting partner prediction and chromatin immunoprecipitation screens, six candidate promoter regions bound by BfmA in vivo were identified. We demonstrated that, among them, BfmA acts as a transcription factor that binds directly to the promoter regions of bfmA-bfmK and Smlt0800 (acoT), a gene encoding an acyl coenzyme A thioesterase that is associated with biofilm development, and positively controls their transcription. Genome-scale mutational analyses of histidine kinase genes and functional dissection of BfmK-BfmA regulation in biofilm provide genetic information to support more in-depth studies on cellular signaling in S. maltophilia, in the context of developing novel approaches to fight this important bacterial pathogen. PMID:26873318

  17. 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.

  18. [Investigation of integrons, sul1-2 and dfr genes in trimethoprim-sulfametoxazole-resistant Stenotrophomonas maltophilia strains isolated from clinical samples].

    PubMed

    Ozkaya, Esra; Aydin, Faruk; Bayramoglu, Gülçin; Buruk, Celal Kurtuluş; Sandalli, Cemal

    2014-04-01

    Stenotrophomonas maltophilia, which is a non-fermentative gram-negative bacillus, has an increasing importance in nosocomial and opportunistic infections. Since it exhibits resistance to numerous broad-spectrum antibiotics such as aminoglycosides, beta-lactams and tetracyclines, it may considerably limit empirical treatment options. Trimethoprim-sulfamethoxazole (SXT) is recommended as the first-line therapy in the treatment of S.maltophilia infections thanks to its high potency and usefulness in a range of patients. In recent years, however, studies in different geographical regions have started to report resistance to SXT. In this study, we aimed to investigate the genes sul1, sul2, dfrA9, dfrA10, dfrA20 and class I, class II integron gene cassettes which are known to play role in SXT resistance among SXT-resistant S.maltophilia strains. A total of 618 S.maltophilia strains isolated from various clinical samples of 339 patients between January 2006 and October 2011 at the laboratory of Medical Microbiology Department, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey, were included in the study. The isolates were identified by both conventional methods and the Phoenix automated identification system (Becton Dickinson, USA). SXT resistance was determined in the isolates of 32 patients (32/339, 9.4%) by both the automated system and agar dilution method of them 29 (90.6%) were hospital-acquired, and 3 (9.4%) were community-acquired. The genes which are known as SXT resistance determining genes including sul1, sul2, dfr genes, and class I and class II integron gene cassettes were analyzed by using specific primers with polymerase chain reaction in the 32 SXT-resistant isolates. Subsequently, nucleotide sequence analysis of the amplified materials was performed. As a result of this assay, the presence of class I integron gene cassette and sul1 gene were detected in one isolate. Nucleotide sequence analysis of the gene cassette revealed oxacilinase

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

    PubMed Central

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

    2015-01-01

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

  20. The Binding of Triclosan to SmeT, the Repressor of the Multidrug Efflux Pump SmeDEF, Induces Antibiotic Resistance in Stenotrophomonas maltophilia

    PubMed Central

    Romero, Antonio; Martínez, José L.

    2011-01-01

    The wide utilization of biocides poses a concern on the impact of these compounds on natural bacterial populations. Furthermore, it has been demonstrated that biocides can select, at least in laboratory experiments, antibiotic resistant bacteria. This situation has raised concerns, not just on scientists and clinicians, but also on regulatory agencies, which are demanding studies on the impact that the utilization of biocides may have on the development on resistance and consequently on the treatment of infectious diseases and on human health. In the present article, we explored the possibility that the widely used biocide triclosan might induce antibiotic resistance using as a model the opportunistic pathogen Stenotrophomonas maltophilia. Biochemical, functional and structural studies were performed, focusing on SmeDEF, the most relevant antibiotic- and triclosan-removing multidrug efflux pump of S. maltophilia. Expression of smeDEF is regulated by the repressor SmeT. Triclosan released SmeT from its operator and induces the expression of smeDEF, thus reducing the susceptibility of S. maltophilia to antibiotics in the presence of the biocide. The structure of SmeT bound to triclosan is described. Two molecules of triclosan were found to bind to one subunit of the SmeT homodimer. The binding of the biocide stabilizes the N terminal domain of both subunits in a conformation unable to bind DNA. To our knowledge this is the first crystal structure obtained for a transcriptional regulator bound to triclosan. This work provides the molecular basis for understanding the mechanisms allowing the induction of phenotypic resistance to antibiotics by triclosan. PMID:21738470

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

    PubMed Central

    DuMont, Ashley L.; Karaba, Sara M.

    2015-01-01

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

  2. Draft Genome Sequences of Stenotrophomonas maltophilia Strains Sm32COP, Sm41DVV, Sm46PAILV, SmF3, SmF22, SmSOFb1, and SmCVFa1, Isolated from Different Manures in France.

    PubMed

    Bodilis, Josselin; Youenou, Benjamin; Briolay, Jérome; Brothier, Elisabeth; Favre-Bonté, Sabine; Nazaret, Sylvie

    2016-01-01

    Stenotrophomonas maltophilia is a major opportunistic human pathogen responsible for nosocomial infections. Here, we report the draft genome sequences of Sm32COP, Sm41DVV, Sm46PAILV, SmF3, SmF22, SmSOFb1, and SmCVFa1, isolated from different manures in France, which provide insights into the genetic determinism of intrinsic or acquired antibiotic resistance in this species. PMID:27540065

  3. Draft Genome Sequences of Stenotrophomonas maltophilia Strains Sm32COP, Sm41DVV, Sm46PAILV, SmF3, SmF22, SmSOFb1, and SmCVFa1, Isolated from Different Manures in France

    PubMed Central

    Bodilis, Josselin; Youenou, Benjamin; Briolay, Jérome; Brothier, Elisabeth; Favre-Bonté, Sabine

    2016-01-01

    Stenotrophomonas maltophilia is a major opportunistic human pathogen responsible for nosocomial infections. Here, we report the draft genome sequences of Sm32COP, Sm41DVV, Sm46PAILV, SmF3, SmF22, SmSOFb1, and SmCVFa1, isolated from different manures in France, which provide insights into the genetic determinism of intrinsic or acquired antibiotic resistance in this species. PMID:27540065

  4. Differentiation of pulmonary bacterial pathogens in cystic fibrosis by volatile metabolites emitted by their in vitro cultures: Pseudomonas aeruginosa, Staphylococcus aureus, Stenotrophomonas maltophilia and the Burkholderia cepacia complex.

    PubMed

    Dryahina, Kseniya; Sovová, Kristýna; Nemec, Alexandr; Španěl, Patrik

    2016-01-01

    As a contribution to the continuing search for breath biomarkers of lung and airways infection in patients with cystic fibrosis, CF, we have analysed the volatile metabolites released in vitro by Pseudomonas aeruginosa and other bacteria involved in respiratory infections in these patients, i.e. those belonging to the Burkholderia cepacia complex, Staphylococcus aureus or Stenotrophomonas maltophilia. These opportunistic pathogens are generally harmless to healthy people but they may cause serious infections in patients with severe underlying disease or impaired immunity such as CF patients. Volatile organic compounds emitted from the cultures of strains belonging to the above-mentioned four taxa were analysed by selected ion flow tube mass spectrometry. In order to minimize the effect of differences in media composition all strains were cultured in three different liquid media. Multivariate statistical analysis reveals that the four taxa can be well discriminated by the differences in the headspace VOC concentration profiles. The compounds that should be targeted in breath as potential biomarkers of airway infection were identified for each of these taxa of CF pathogens. PMID:27506232

  5. 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

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

    PubMed Central

    Cai, Xuejiu; Zhao, Jin; Cui, Junchang

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  9. Inactivation of SmeSyRy Two-Component Regulatory System Inversely Regulates the Expression of SmeYZ and SmeDEF Efflux Pumps in Stenotrophomonas maltophilia.

    PubMed

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

    2016-01-01

    SmeYZ efflux pump is a critical pump responsible for aminoglycosides resistance, virulence-related characteristics (oxidative stress susceptibility, motility, and secreted protease activity), and virulence in Stenotrophomonas maltophilia. However, the regulatory circuit involved in SmeYZ expression is little known. A two-component regulatory system (TCS), smeRySy, transcribed divergently from the smeYZ operon is the first candidate to be considered. To assess the role of SmeRySy in smeYZ expression, the smeRySy isogenic deletion mutant, KJΔRSy, was constructed by gene replacement strategy. Inactivation of smeSyRy correlated with a higher susceptibility to aminoglycosides concomitant with an increased resistance to chloramphenicol, ciprofloxacin, tetracycline, and macrolides. To elucidate the underlying mechanism responsible for the antimicrobials susceptibility profiles, the SmeRySy regulon was firstly revealed by transcriptome analysis and further confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and promoter transcription fusion constructs assay. The results demonstrate that inactivation of smeRySy decreased the expression of SmeYZ pump and increased the expression of SmeDEF pump, which underlies the ΔsmeSyRy-mediated antimicrobials susceptibility profile. To elucidate the cognate relationship between SmeSy and SmeRy, a single mutant, KJΔRy, was constructed and the complementation assay of KJΔRSy with smeRy were performed. The results support that SmeSy-SmeRy TCS is responsible for the regulation of smeYZ operon; whereas SmeSy may be cognate with another unidentified response regulator for the regulation of smeDEF operon. The impact of inverse expression of SmeYZ and SmeDEF pumps on physiological functions was evaluated by mutants construction, H2O2 susceptibility test, swimming, and secreted protease activity assay. The increased expression of SmeDEF pump in KJΔRSy may compensate, to some extents, the SmeYZ downexpression

  10. Inactivation of SmeSyRy Two-Component Regulatory System Inversely Regulates the Expression of SmeYZ and SmeDEF Efflux Pumps in Stenotrophomonas maltophilia.

    PubMed

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

    2016-01-01

    SmeYZ efflux pump is a critical pump responsible for aminoglycosides resistance, virulence-related characteristics (oxidative stress susceptibility, motility, and secreted protease activity), and virulence in Stenotrophomonas maltophilia. However, the regulatory circuit involved in SmeYZ expression is little known. A two-component regulatory system (TCS), smeRySy, transcribed divergently from the smeYZ operon is the first candidate to be considered. To assess the role of SmeRySy in smeYZ expression, the smeRySy isogenic deletion mutant, KJΔRSy, was constructed by gene replacement strategy. Inactivation of smeSyRy correlated with a higher susceptibility to aminoglycosides concomitant with an increased resistance to chloramphenicol, ciprofloxacin, tetracycline, and macrolides. To elucidate the underlying mechanism responsible for the antimicrobials susceptibility profiles, the SmeRySy regulon was firstly revealed by transcriptome analysis and further confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and promoter transcription fusion constructs assay. The results demonstrate that inactivation of smeRySy decreased the expression of SmeYZ pump and increased the expression of SmeDEF pump, which underlies the ΔsmeSyRy-mediated antimicrobials susceptibility profile. To elucidate the cognate relationship between SmeSy and SmeRy, a single mutant, KJΔRy, was constructed and the complementation assay of KJΔRSy with smeRy were performed. The results support that SmeSy-SmeRy TCS is responsible for the regulation of smeYZ operon; whereas SmeSy may be cognate with another unidentified response regulator for the regulation of smeDEF operon. The impact of inverse expression of SmeYZ and SmeDEF pumps on physiological functions was evaluated by mutants construction, H2O2 susceptibility test, swimming, and secreted protease activity assay. The increased expression of SmeDEF pump in KJΔRSy may compensate, to some extents, the SmeYZ downexpression

  11. Inactivation of SmeSyRy Two-Component Regulatory System Inversely Regulates the Expression of SmeYZ and SmeDEF Efflux Pumps in Stenotrophomonas maltophilia

    PubMed Central

    Lin, Yi-Tsung; Ning, Hsiao-Chen; Yang, Tsuey-Ching

    2016-01-01

    SmeYZ efflux pump is a critical pump responsible for aminoglycosides resistance, virulence-related characteristics (oxidative stress susceptibility, motility, and secreted protease activity), and virulence in Stenotrophomonas maltophilia. However, the regulatory circuit involved in SmeYZ expression is little known. A two-component regulatory system (TCS), smeRySy, transcribed divergently from the smeYZ operon is the first candidate to be considered. To assess the role of SmeRySy in smeYZ expression, the smeRySy isogenic deletion mutant, KJΔRSy, was constructed by gene replacement strategy. Inactivation of smeSyRy correlated with a higher susceptibility to aminoglycosides concomitant with an increased resistance to chloramphenicol, ciprofloxacin, tetracycline, and macrolides. To elucidate the underlying mechanism responsible for the antimicrobials susceptibility profiles, the SmeRySy regulon was firstly revealed by transcriptome analysis and further confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and promoter transcription fusion constructs assay. The results demonstrate that inactivation of smeRySy decreased the expression of SmeYZ pump and increased the expression of SmeDEF pump, which underlies the ΔsmeSyRy-mediated antimicrobials susceptibility profile. To elucidate the cognate relationship between SmeSy and SmeRy, a single mutant, KJΔRy, was constructed and the complementation assay of KJΔRSy with smeRy were performed. The results support that SmeSy-SmeRy TCS is responsible for the regulation of smeYZ operon; whereas SmeSy may be cognate with another unidentified response regulator for the regulation of smeDEF operon. The impact of inverse expression of SmeYZ and SmeDEF pumps on physiological functions was evaluated by mutants construction, H2O2 susceptibility test, swimming, and secreted protease activity assay. The increased expression of SmeDEF pump in KJΔRSy may compensate, to some extents, the SmeYZ downexpression

  12. The 1.1 Å resolution structure of a periplasmic phosphate-binding protein from Stenotrophomonas maltophilia: a crystallization contaminant identified by molecular replacement using the entire Protein Data Bank.

    PubMed

    Keegan, Ronan; Waterman, David G; Hopper, David J; Coates, Leighton; Taylor, Graham; Guo, Jingxu; Coker, Alun R; Erskine, Peter T; Wood, Steve P; Cooper, Jonathan B

    2016-08-01

    During efforts to crystallize the enzyme 2,4-dihydroxyacetophenone dioxygenase (DAD) from Alcaligenes sp. 4HAP, a small number of strongly diffracting protein crystals were obtained after two years of crystal growth in one condition. The crystals diffracted synchrotron radiation to almost 1.0 Å resolution and were, until recently, assumed to be formed by the DAD protein. However, when another crystal form of this enzyme was eventually solved at lower resolution, molecular replacement using this new structure as the search model did not give a convincing solution with the original atomic resolution data set. Hence, it was considered that these crystals might have arisen from a protein impurity, although molecular replacement using the structures of common crystallization contaminants as search models again failed. A script to perform molecular replacement using MOLREP in which the first chain of every structure in the PDB was used as a search model was run on a multi-core cluster. This identified a number of prokaryotic phosphate-binding proteins as scoring highly in the MOLREP peak lists. Calculation of an electron-density map at 1.1 Å resolution based on the solution obtained with PDB entry 2q9t allowed most of the amino acids to be identified visually and built into the model. A BLAST search then indicated that the molecule was most probably a phosphate-binding protein from Stenotrophomonas maltophilia (UniProt ID B4SL31; gene ID Smal_2208), and fitting of the corresponding sequence to the atomic resolution map fully corroborated this. Proteins in this family have been linked to the virulence of antibiotic-resistant strains of pathogenic bacteria and with biofilm formation. The structure of the S. maltophilia protein has been refined to an R factor of 10.15% and an Rfree of 12.46% at 1.1 Å resolution. The molecule adopts the type II periplasmic binding protein (PBP) fold with a number of extensively elaborated loop regions. A fully dehydrated phosphate

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

    PubMed

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

    2015-11-01

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

  14. Genome Sequence of Type Strains of Genus Stenotrophomonas

    PubMed Central

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

    2016-01-01

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

  15. 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...

  16. 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.

  17. Stenotrophomonas Infection in a Patient with Glucose-6-Phosphate Dehydrogenase Deficiency

    PubMed Central

    Harthan, Aaron A.; Heger, Margaret L

    2013-01-01

    The drug of choice for treatment of Stenotrophomonas maltophilia is sulfamethoxazole/trimethoprim, and second-line therapy usually consists of a fluoroquinolone. However, in patients with glucose-6-phosphate dehydrogenase deficiency, neither sulfamethoxazole/trimethoprim nor a fluoroquinolone is a preferred option as it may result in hemolysis. Currently, there is a paucity of data regarding treatment of S maltophilia infection in these patients. This case report presents a patient who was successfully treated with doxycycline and inhaled colistimethate. PMID:23798908

  18. Structure of Aminodeoxychorismate Synthase from Stenotrophomonas maltophilia†

    PubMed Central

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

    2012-01-01

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

  19. Synthesis of the compatible solutes glucosylglycerol and trehalose by salt-stressed cells of Stenotrophomonas strains.

    PubMed

    Roder, Anja; Hoffmann, Eik; Hagemann, Martin; Berg, Gabriele

    2005-02-01

    In this study, physiological processes were analysed, which are involved in salt acclimation of two Stenotrophomonas species, Stenotrophomonas maltophilia strain DSM 50170 and Stenotrophomonas rhizophila strain DSM 14405. S. maltophilia accumulated trehalose as the only osmolyte, whereas S. rhizophila produced additionally to trehalose glucosylglycerol (GG). The different spectrum and amounts of compatible solutes in these two strains led to differences in terms of their salt tolerance. The human-associated S. maltophilia was able to grow in media containing up to 3% NaCl (w/v). In contrast, S. rhizophila propagated in salinities up to 5% NaCl (w/v). The strain was isolated from the rhizosphere, a microenvironment which is characterised by high and changing salinities. Light microscopic analysis of S. rhizophila cells showed a significant increase in cell length of salt-treated cells in comparison to control cells. Cells of S. rhizophila exposed to more than 2% NaCl excreted GG into the medium during the transition from exponential to stationary growth phase, while the internal trehalose pool remained constant. This feature offers a high potential for the biotechnological production of GG.

  20. Screening for endophytic nitrogen-fixing bacteria in Brazilian sugar cane varieties used in organic farming and description of Stenotrophomonas pavanii sp. nov.

    PubMed

    Ramos, Patrícia L; Van Trappen, Stefanie; Thompson, Fabiano L; Rocha, Rafael C S; Barbosa, Heloiza R; De Vos, Paul; Moreira-Filho, Carlos A

    2011-04-01

    A Gram-negative, rod-shaped, non-spore-forming and nitrogen-fixing bacterium, designated ICB 89(T), was isolated from stems of a Brazilian sugar cane variety widely used in organic farming. 16S rRNA gene sequence analysis revealed that strain ICB 89(T) belonged to the genus Stenotrophomonas and was most closely related to Stenotrophomonas maltophilia LMG 958(T), Stenotrophomonas rhizophila LMG 22075(T), Stenotrophomonas nitritireducens L2(T), [Pseudomonas] geniculata ATCC 19374(T), [Pseudomonas] hibiscicola ATCC 19867(T) and [Pseudomonas] beteli ATCC 19861(T). DNA-DNA hybridization together with chemotaxonomic data and biochemical characteristics allowed the differentiation of strain ICB 89(T) from its nearest phylogenetic neighbours. Therefore, strain ICB 89(T) represents a novel species, for which the name Stenotrophomonas pavanii sp. nov. is proposed. The type strain is ICB 89(T) ( = CBMAI 564(T)  = LMG 25348(T)).

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

    PubMed

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

    2015-10-01

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

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

    PubMed

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

    2015-10-01

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

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

    PubMed

    Abbott, Iain J; Peleg, Anton Y

    2015-02-01

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

  4. Draft Genome Sequence of Bacillus subtilis subsp. natto Strain CGMCC 2108, a High Producer of Poly-γ-Glutamic Acid

    PubMed Central

    Tan, Siyuan; Su, Anping; Zhang, Chen; Ren, Yuanyuan

    2016-01-01

    Here, we report the 4.1-Mb draft genome sequence of Bacillus subtilis subsp. natto strain CGMCC 2108, a high producer of poly-γ-glutamic acid (γ-PGA). This sequence will provide further help for the biosynthesis of γ-PGA and will greatly facilitate research efforts in metabolic engineering of B. subtilis subsp. natto strain CGMCC 2108. PMID:27231363

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

    PubMed

    Juhnke, M E; des Jardin, E

    1989-03-01

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

  6. 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.

  7. 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.

  8. Biodegradation and dissolution of polyaromatic hydrocarbons by Stenotrophomonas sp.

    PubMed

    Tiwari, Bhagyashree; Manickam, N; Kumari, Smita; Tiwari, Akhilesh

    2016-09-01

    The aim of this work was to study the biodegradation capabilities of a locally isolated bacterium, Stenotrophomonas sp. strain IITR87 to degrade the polycyclic aromatic hydrocarbons and also check the preferential biodegradation of polycyclic aromatic hydrocarbons (PAHs). From preferential substrate degradation studies, it was found that Stenotrophomonas sp. strain IITR87 first utilized phenanthrene (three membered ring), followed by pyrene (four membered ring), then benzo[α]pyrene (five membered ring). Dissolution study of PAHs with surfactants, rhamnolipid and tritonX-100 showed that the dissolution of PAHs increased in the presence of surfactants. PMID:27342606

  9. 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

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

    PubMed Central

    Jin, Decai; Zhou, Lisha; Zhang, Zhuo

    2016-01-01

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

  11. Effect of temperature on antimicrobial susceptibilities of Pseudomonas maltophilia.

    PubMed Central

    Wheat, P F; Winstanley, T G; Spencer, R C

    1985-01-01

    After a case of peritonitis caused by Pseudomonas maltophilia had occurred 20 strains of the organism were investigated and the minimum inhibitory concentrations of a variety of antibiotics determined at 30 degrees C and 37 degrees C. There was a significant difference in susceptibility between 30 degrees C (most resistant) and 37 degrees C (most susceptible) for aminoglycosides and polymyxin B. No difference was seen with the other agents or in strains of Ps aeruginosa and Enterobacteriaceae tested under similar conditions. The possible mechanisms of this phenomenon are discussed below. Images PMID:4044874

  12. Isolation of α-arbutin from Xanthomonas CGMCC 1243 fermentation broth by macroporous resin adsorption chromatography.

    PubMed

    Liu, Chunqiao; Zhang, Peng; Liu, Luo; Xu, Tao; Tan, Tianwei; Wang, Fang; Deng, Li

    2013-04-15

    α-Arbutin is a glycosylated hydroquinone which has inhibitory function against tyrosinase. In this work, a one-step isolation of α-arbutin from Xanthomonas CGMCC 1243 fermentation broth by macroporous resin adsorption chromatography was investigated. The research results indicated that S-8 resin offered the best adsorption and desorption capacities for α-arbutin than others and its equilibrium adsorption data were well-fitted to the Freundlich isotherm. In order to optimize the operating parameters for separating α-arbutin, dynamic adsorption and desorption tests on S-8 column chromatography were carried out. Under optimized conditions (adsorption volume of 7 bed volume (BV), mobile phase of 25% (v/v) ethanol solution and elution volume of 3 BV), the purity and recovery of α-arbutin were 97.3% (w/w) and 90.9% (w/w), respectively. The product was identified as α-arbutin by (13)C NMR and (1)H NMR analysis. Moreover, we scaled up S-8 column from laboratory test (10 cm × 2 cm ID) to large scale (500 cm × 100 cm ID) without diminishing α-arbutin yield. In conclusion, the results in this work provide a one-step and cost-effective method for large-scale production of α-arbutin.

  13. Characterization of a New Cell Envelope Proteinase PrtP from Lactobacillus rhamnosus CGMCC11055.

    PubMed

    Guo, Tingting; Ouyang, Xudong; Xin, Yongping; Wang, Yue; Zhang, Susu; Kong, Jian

    2016-09-21

    Cell envelope proteinases (CEPs) play essential roles in lactic acid bacteria growth in milk and health-promoting properties of fermented dairy products. The genome of Lactobacillus rhamnosus CGMCC11055 possesses two putative CEP genes prtP and prtR2, and the PrtP displays the distinctive domain organization from PrtR2 reported. The PrtP was purified and biochemically characterized. The results showed that the optimal activity occurred at 44 °C, pH 6.5. p-Amidinophenylmethylsulfonyl fluoride obviously inhibited enzymatic activity, suggesting PrtP was a member of serine proteinases. Under the optimal conditions, β-casein was a favorite substrate over αS1- and κ-casein, and 35 oligopeptides were identified in the β-casein hydrolysate, including the phosphoserine peptide and bioactive isoleucine-proline-proline. By analysis of the amino acid sequences of those oligopeptides, proline was the preferred residue at the breakdown site. Therefore, we speculated that PrtP was a new type of CEPs from Lb. rhamnosus. PMID:27585760

  14. Biodegradation and metabolic pathway of β-chlorinated aliphatic acid in Bacillus sp. CGMCC no. 4196.

    PubMed

    Lin, Chunjiao; Yang, Lirong; Xu, Gang; Wu, Jianping

    2011-04-01

    In this study, a bacterial Bacillus sp. CGMCC no. 4196 was isolated from mud. This strain exhibited the ability to degrade high concentration of 3-chloropropionate (3-CPA, 120 mM) or 3-chlorobutyrate (30 mM), but not chloroacetate or 2-chloropropionate (2-CPA). The growing cells, resting cells, and cell-free extracts from this bacterium had the capability of 3-CPA degradation. The results indicated that the optimum biocatalyst for 3-CPA biodegradation was the resting cells. The 3-CPA biodegradation pathway was further studied through the metabolites and critical enzymes analysis by HPLC, LC-MS, and colorimetric method. The results demonstrated that the metabolites of 3-CPA were 3-hydroxypropionic acid (3-HP) and malonic acid semialdehyde, and the critical enzymes were 3-CPA dehalogenase and 3-HP dehydroxygenase. Thus, the mechanism of the dehalogenase-catalyzed reaction was inferred as hydrolytic dehalogenation which was coenzyme A-independent and oxygen-independent. Finally, the pathway of β-chlorinated aliphatic acid biodegradation could be concluded as follows: the β-chlorinated acid is first hydrolytically dehalogenated to the β-hydroxyl aliphatic acid, and the hydroxyl aliphatic acid is oxidized to β-carbonyl aliphatic acid by β-hydroxy aliphatic acid dehydroxygenase. It is the first report that 3-HP was produced from 3-CPA by β-chlorinated aliphatic acid dehalogenase.

  15. Why sucrose is the most suitable substrate for pullulan fermentation by Aureobasidium pullulans CGMCC1234?

    PubMed

    Sheng, Long; Tong, Qunyi; Ma, Meihu

    2016-10-01

    This paper studies the metabolic pathway of sucrose in pullulan fermentation by Aureobasidium pullulans. Because of its high pullulan production, sucrose proved to be the best carbon source for pullulan synthesis by A. pullulans CGMCC1234 (36.3g/L). Compared to other carbon sources, A. pullulans cells reached the stationary phase more quickly in the presence of sucrose. The specific sugar types and concentrations occurring during pullulan fermentation were detected using High Performance Liquid Chromatography (HPLC). HPLC results revealed that sucrose did not simply break down into glucose and fructose in the medium employed. Kestose (22.69g/L) also accumulated during early stages of fermentation (24h), which reduced the osmotic pressure of the extracellular fluid and diminished the inhibition of cell growth and pullulan production. β-Fructofuranosidase activity strongly depended on the carbon source. Sucrose was the best inducer of β-fructofuranosidase production. However, β-fructofuranosidase production did not directly and/or proportionally correlate with the growth of A. pullulans cells. PMID:27542744

  16. 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.

  17. 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

    Guzik, Urszula; Hupert-Kocurek, Katarzyna; Krysiak, Marta; Wojcieszyńska, Danuta

    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

  18. 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

    Guzik, Urszula; Hupert-Kocurek, Katarzyna; Krysiak, Marta; Wojcieszyńska, Danuta

    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.

  19. Immunoelectron microscopic demonstration of an esterase on the outer membrane of Xanthomonas maltophilia.

    PubMed Central

    Debette, J; Prensier, G

    1989-01-01

    Xanthomonas maltophilia (later synonym of Pseudomonas maltophilia), an ubiquitous species, is known to show proteolytic and lipolytic activities. A cell-bound esterase which hydrolyzes beta-naphthyl acetate during growth has been extracted from a strain isolated from soil. Because of its strongly hydrophobic character, the enzyme could be efficiently solubilized only by Triton X-100. This nonionic detergent must be added in polyacrylamide gels to permit migration. Polyclonal rabbit antibodies raised against the Triton-soluble esterase complex were used to localize the enzyme at the ultrastructural level. Electron microscopy of cell sections of this organism and immunogold labeling demonstrated that the enzyme was located on the outer membrane. Such an envelope-bound esterase may produce assimilable substrates for X. maltophilia which can grow in various environments. Images PMID:2495761

  20. 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

  1. 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.

  2. 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

  3. Effect of Lactobacillus rhamnosus CGMCC1.3724 supplementation on weight loss and maintenance in obese men and women.

    PubMed

    Sanchez, Marina; Darimont, Christian; Drapeau, Vicky; Emady-Azar, Shahram; Lepage, Melissa; Rezzonico, Enea; Ngom-Bru, Catherine; Berger, Bernard; Philippe, Lionel; Ammon-Zuffrey, Corinne; Leone, Patricia; Chevrier, Genevieve; St-Amand, Emmanuelle; Marette, André; Doré, Jean; Tremblay, Angelo

    2014-04-28

    The present study investigated the impact of a Lactobacillus rhamnosus CGMCC1.3724 (LPR) supplementation on weight loss and maintenance in obese men and women over 24 weeks. In a double-blind, placebo-controlled, randomised trial, each subject consumed two capsules per d of either a placebo or a LPR formulation (1.6 × 10(8) colony-forming units of LPR/capsule with oligofructose and inulin). Each group was submitted to moderate energy restriction for the first 12 weeks followed by 12 weeks of weight maintenance. Body weight and composition were measured at baseline, at week 12 and at week 24. The intention-to-treat analysis showed that after the first 12 weeks and after 24 weeks, mean weight loss was not significantly different between the LPR and placebo groups when all the subjects were considered. However, a significant treatment × sex interaction was observed. The mean weight loss in women in the LPR group was significantly higher than that in women in the placebo group (P = 0.02) after the first 12 weeks, whereas it was similar in men in the two groups (P= 0.53). Women in the LPR group continued to lose body weight and fat mass during the weight-maintenance period, whereas opposite changes were observed in the placebo group. Changes in body weight and fat mass during the weight-maintenance period were similar in men in both the groups. LPR-induced weight loss in women was associated not only with significant reductions in fat mass and circulating leptin concentrations but also with the relative abundance of bacteria of the Lachnospiraceae family in faeces. The present study shows that the Lactobacillus rhamnosus CGMCC1.3724 formulation helps obese women to achieve sustainable weight loss.

  4. Comparative in vitro activities of newer quinolones against Pseudomonas species and Xanthomonas maltophilia isolated from patients with cancer.

    PubMed Central

    Rolston, K V; Messer, M; Ho, D H

    1990-01-01

    The in vitro susceptibilities of three Pseudomonas species (Pseudomonas aeruginosa, Pseudomonas putida, and Pseudomonas fluorescens) and Xanthomonas maltophilia to quinolone antimicrobial agents were determined. Several newer agents, particularly PD117558, PD117596, PD127391, sparfloxacin (AT-4140), A-56620, and temafloxacin, were active against Pseudomonas species. X. maltophilia isolates were generally less susceptible than were Pseudomonas isolates but were inhibited by some of the newer quinolones. PMID:2285297

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

    PubMed

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

    2015-01-01

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

  6. 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

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

    PubMed

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

    2015-01-01

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

  8. Sophorolipids production from rice straw via SO3 micro-thermal explosion by Wickerhamiella domercqiae var. sophorolipid CGMCC 1576.

    PubMed

    Liu, Xin-Ge; Ma, Xiao-Jing; Yao, Ri-Sheng; Pan, Chun-Yu; He, Hua-Bing

    2016-12-01

    A novel lignocellulose material, holocellulose from rice straw via the pretreatment of SO3 micro-thermal explosion, was developed to produce sophorolipids (SLs) with Wickerhamiella domercqiae var. sophorolipid CGMCC 1576. The influence factors of inoculum dose, yeast extract concentration and pH regulators (chemical regents used for adjusting/influencing pH) was investigated and discussed. Results showed that W. domercqiae can grow in the rice straw holocellulose hydrolysate, and acquire relative high SL yield of 53.70 ± 2.61 g/L in shake flask culture. Inoculum dose, yeast extract concentration and pH regulator made obvious influence on fermentation parameters, especially on final broth pH and SLs production. Furthermore, there is a strong negative linear correlation existing between final broth pH and lactonic SL or ratio of lac SL/tot SL. Additionally, comparison between SL production and non-glucose carbon sources, culture methods, microbes in previous reports was carried out. These results will be benefit for acquiring SL mixture with suitable lac SL/tot SL ratio for specific purpose and scope economically. PMID:27568226

  9. Protein purification, crystallization and preliminary X-ray diffraction analysis of L-arabinose isomerase from Lactobacillus fermentum CGMCC2921.

    PubMed

    Xu, Zheng; Li, Sha; Liang, Jinfeng; Feng, Xiaohai; Xu, Hong

    2015-01-01

    L-Arabinose isomerase (AI) catalyzes the isomerization of L-arabinose to L-ribulose, as well as that of D-galactose to D-tagatose. A thermophilic AI derived from Lactobacillus fermentum CGMCC2921 (LFAI) was overexpressed in Escherichia coli BL21 (DE3). This enzyme was purified to over 95% purity by nickel affinity, Mono-Q ion-exchange and size-exclusion chromatography. The LFAI protein was crystallized from either 0.1 M bis-tris pH 6.5, 23% PEG 3350, 0.3 M NaCl (form 1 crystals) or 0.1 M bis-tris pH 6.0, 25% PEG monomethyl ether 5000 (form 2 crystals). Diffraction data from form 1 LFAI crystals were collected to 2.80 Å resolution using synchrotron radiation. The form 1 crystals belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a=85.11, b=184.57, c=186.26 Å, α=β=γ=90°. The asymmetric unit contained six LFAI subunits, corresponding to a calculated Matthews coefficient of 2.29 Å3 Da(-1) and a solvent content of 46.22%.

  10. Production of bacterial cellulose by Gluconacetobacter hansenii CGMCC 3917 using only waste beer yeast as nutrient source.

    PubMed

    Lin, Dehui; Lopez-Sanchez, Patricia; Li, Rui; Li, Zhixi

    2014-01-01

    In order to improve the use of waste beer yeast (WBY) for bacterial cellulose production by Gluconacetobacter hansenii CGMCC 3917, a two-step pre-treatment was designed. First WBY was treated by 4 methods: 0.1M NaOH treatment, high speed homogenizer, ultrasonication and microwave treatment followed by hydrolysis (121°C, 20 min) under mild acid condition (pH 2). The optimal pre-treatment conditions were evaluated by the reducing sugar yield after hydrolysis. 15% WBY treated by ultrasonication for 40 min had the highest reducing sugar yield (29.19%), followed by NaOH treatment (28.98%), high speed homogenizer (13.33%) and microwaves (13.01%). Treated WBY hydrolysates were directly supplied as only nutrient source for BC production. A sugar concentration of 3% WBY hydrolysates treated by ultrasonication gave the highest BC yield (7.02 g/L), almost 6 times as that from untreated WBY (1.21 g/L). Furthermore, the properties of the BC were as good as those obtained from the conventional chemical media.

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

    PubMed

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

    2016-01-01

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

  12. 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

  13. Influence of nutrient mixtures on p-nitrophenol degradation by Stenotrophomonas sp. isolated from groundwater.

    PubMed

    Subashchandrabose, Suresh R; Megharaj, Mallavarapu; Venkateswarlu, Kadiyala; Lockington, Robin; Naidu, Ravi

    2013-01-01

    We isolated strain CERAR5, a Stenotrophomonas sp., from an aquifer contaminated with chlorinated hydrocarbons that utilizes up to 1.0 mM PNP within 62 h in M9 medium as a source of carbon and nitrogen. To assess the potential of this strain for use in bioremediation, we investigated the influence of external sources of carbon and nitrogen on bacterial degradation of PNP following a full factorial design analysis. Glucose, sodium acetate, phenol, sodium nitrate and ammonium chloride were the factors chosen, while per cent removal of PNP, growth of the bacterial strain, and change in pH of the medium were the responses measured. Glucose and acetate had significant positive influence on the removal PNP. In particular, acetate exhibited a significant positive effect on all the three responses measured, clearly suggesting that the addition of acetate greatly contributes to an efficient bioremediation of habitats contaminated with PNP by Stenotrophomonas sp. CERAR5.

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

    SciTech Connect

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

    1996-01-05

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

    Felici, A; Amicosante, G

    1995-01-01

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

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

    PubMed

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

    2013-09-28

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

  20. Isolation of new Stenotrophomonas bacteriophages and genomic characterization of temperate phage S1.

    PubMed

    García, Pilar; Monjardín, Cristina; Martín, Rebeca; Madera, Carmen; Soberón, Nora; Garcia, Eva; Meana, Alvaro; Suárez, Juan E

    2008-12-01

    Twenty-two phages that infect Stenotrophomonas species were isolated through sewage enrichment and prophage induction. Of them, S1, S3, and S4 were selected due to their wide host ranges compared to those of the other phages. S1 and S4 are temperate siphoviruses, while S3 is a virulent myovirus. The genomes of S3 and S4, about 33 and 200 kb, were resistant to restriction digestion. The lytic cycles lasted 30 min for S3 and about 75 min for S1 and S4. The burst size for S3 was 100 virions/cell, while S1 and S4 produced about 75 virus particles/cell. The frequency of bacteriophage-insensitive host mutants, calculated by dividing the number of surviving colonies by the bacterial titer of a parallel, uninfected culture, ranged between 10(-5) and 10(-6) for S3 and 10(-3) and 10(-4) for S1 and S4. The 40,287-bp genome of S1 contains 48 open reading frames (ORFs) and 12-bp 5' protruding cohesive ends. By using a combination of bioinformatics and experimental evidence, functions were ascribed to 21 ORFs. The morphogenetic and lysis modules are well-conserved, but no lysis-lysogeny switch or DNA replication gene clusters were recognized. Two major clusters of genes with respect to transcriptional orientation were observed. Interspersed among them were lysogenic conversion genes encoding phosphoadenosine phosphosulfate reductase and GspM, a protein involved in the general secretion system II. The attP site of S1 may be located within a gene that presents over 75% homology to a Stenotrophomonas chromosomal determinant.

  1. Isolation of New Stenotrophomonas Bacteriophages and Genomic Characterization of Temperate Phage S1▿

    PubMed Central

    García, Pilar; Monjardín, Cristina; Martín, Rebeca; Madera, Carmen; Soberón, Nora; Garcia, Eva; Meana, Álvaro; Suárez, Juan E.

    2008-01-01

    Twenty-two phages that infect Stenotrophomonas species were isolated through sewage enrichment and prophage induction. Of them, S1, S3, and S4 were selected due to their wide host ranges compared to those of the other phages. S1 and S4 are temperate siphoviruses, while S3 is a virulent myovirus. The genomes of S3 and S4, about 33 and 200 kb, were resistant to restriction digestion. The lytic cycles lasted 30 min for S3 and about 75 min for S1 and S4. The burst size for S3 was 100 virions/cell, while S1 and S4 produced about 75 virus particles/cell. The frequency of bacteriophage-insensitive host mutants, calculated by dividing the number of surviving colonies by the bacterial titer of a parallel, uninfected culture, ranged between 10−5 and 10−6 for S3 and 10−3 and 10−4 for S1 and S4. The 40,287-bp genome of S1 contains 48 open reading frames (ORFs) and 12-bp 5′ protruding cohesive ends. By using a combination of bioinformatics and experimental evidence, functions were ascribed to 21 ORFs. The morphogenetic and lysis modules are well-conserved, but no lysis-lysogeny switch or DNA replication gene clusters were recognized. Two major clusters of genes with respect to transcriptional orientation were observed. Interspersed among them were lysogenic conversion genes encoding phosphoadenosine phosphosulfate reductase and GspM, a protein involved in the general secretion system II. The attP site of S1 may be located within a gene that presents over 75% homology to a Stenotrophomonas chromosomal determinant. PMID:18952876

  2. 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.

  3. Astaxanthin preparation by fermentation of esters from Haematococcus pluvialis algal extracts with Stenotrophomonas species.

    PubMed

    Dong, Hao; Li, Xuemin; Xue, Changhu; Mao, Xiangzhao

    2016-05-01

    Natural astaxanthin (Ax) is an additive that is widely used because of its beneficial biochemical functions. However, the methods used to produce free Ax have drawbacks. Chemical saponification methods produce several by-products, and lipase-catalyzed hydrolysis methods are not cost effective. In this study, a bacterial strain of Stenotrophomonas sp. was selected to enzymatically catalyze the saponification of Ax esters to produce free all-trans-Ax. Through single-factor experiments and a Box-Behnken design, the optimal fermentation conditions were determined as follows: a seed culture age of 37.79 h, an inoculum concentration of 5.92%, and an initial broth pH of 6.80. Under these conditions, a fermentation curve was drawn, and the optimal fermentation time was shown to be 60 h. At 60 h, the degradation rate of the Ax esters was 98.08%, and the yield of free all-trans-Ax was 50.130 μg/mL. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:649-656, 2016.

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  7. Thrombus Degradation by Fibrinolytic Enzyme of Stenotrophomonas sp. Originated from Indonesian Soybean-Based Fermented Food on Wistar Rats.

    PubMed

    Nailufar, Florensia; Tjandrawinata, Raymond R; Suhartono, Maggy T

    2016-01-01

    Objective. To evaluate thrombus degrading effect of a fibrinolytic enzyme from food origin Stenotrophomonas sp. of Indonesia. Methods. Prior to animal study, the enzyme safety was tested using cell culture. The effect on expression of tissue plasminogen activator was also analysed in the cell culture. For in vivo studies, 25 Wistar rats were used: normal control, negative control, treatment groups with crude and semipurified enzyme given orally at 25 mg/kg, and positive control group which received Lumbrokinase at 25 mg/kg. Blood clot in the tail was induced by kappa carrageenan injection at 1 mg/kg BW. Results. Experiment with cell culture confirmed the enzyme safety at the concentration used and increased expression of tPA. Decreasing of thrombus was observed in the positive group down to 70.35 ± 23.11% of the negative control animals (100%). The thrombus observed in the crude enzyme treatment was down to 56.99 ± 15.95% and 71.5 ± 15.7% for semipurified enzyme. Scanning electron microscopy showed clearly that bood clots were found in the animals injected with kappa carrageenan; however, in the treatment and positive groups, the clot was much reduced. Conclusions. Oral treatment of enzyme from Stenotrophomonas sp. of Indonesian fermented food was capable of degrading thrombus induced in Wistar rats. PMID:27635131

  8. Thrombus Degradation by Fibrinolytic Enzyme of Stenotrophomonas sp. Originated from Indonesian Soybean-Based Fermented Food on Wistar Rats

    PubMed Central

    Tjandrawinata, Raymond R.

    2016-01-01

    Objective. To evaluate thrombus degrading effect of a fibrinolytic enzyme from food origin Stenotrophomonas sp. of Indonesia. Methods. Prior to animal study, the enzyme safety was tested using cell culture. The effect on expression of tissue plasminogen activator was also analysed in the cell culture. For in vivo studies, 25 Wistar rats were used: normal control, negative control, treatment groups with crude and semipurified enzyme given orally at 25 mg/kg, and positive control group which received Lumbrokinase at 25 mg/kg. Blood clot in the tail was induced by kappa carrageenan injection at 1 mg/kg BW. Results. Experiment with cell culture confirmed the enzyme safety at the concentration used and increased expression of tPA. Decreasing of thrombus was observed in the positive group down to 70.35 ± 23.11% of the negative control animals (100%). The thrombus observed in the crude enzyme treatment was down to 56.99 ± 15.95% and 71.5 ± 15.7% for semipurified enzyme. Scanning electron microscopy showed clearly that bood clots were found in the animals injected with kappa carrageenan; however, in the treatment and positive groups, the clot was much reduced. Conclusions. Oral treatment of enzyme from Stenotrophomonas sp. of Indonesian fermented food was capable of degrading thrombus induced in Wistar rats.

  9. Thrombus Degradation by Fibrinolytic Enzyme of Stenotrophomonas sp. Originated from Indonesian Soybean-Based Fermented Food on Wistar Rats

    PubMed Central

    Tjandrawinata, Raymond R.

    2016-01-01

    Objective. To evaluate thrombus degrading effect of a fibrinolytic enzyme from food origin Stenotrophomonas sp. of Indonesia. Methods. Prior to animal study, the enzyme safety was tested using cell culture. The effect on expression of tissue plasminogen activator was also analysed in the cell culture. For in vivo studies, 25 Wistar rats were used: normal control, negative control, treatment groups with crude and semipurified enzyme given orally at 25 mg/kg, and positive control group which received Lumbrokinase at 25 mg/kg. Blood clot in the tail was induced by kappa carrageenan injection at 1 mg/kg BW. Results. Experiment with cell culture confirmed the enzyme safety at the concentration used and increased expression of tPA. Decreasing of thrombus was observed in the positive group down to 70.35 ± 23.11% of the negative control animals (100%). The thrombus observed in the crude enzyme treatment was down to 56.99 ± 15.95% and 71.5 ± 15.7% for semipurified enzyme. Scanning electron microscopy showed clearly that bood clots were found in the animals injected with kappa carrageenan; however, in the treatment and positive groups, the clot was much reduced. Conclusions. Oral treatment of enzyme from Stenotrophomonas sp. of Indonesian fermented food was capable of degrading thrombus induced in Wistar rats. PMID:27635131

  10. The plant-associated bacterium Stenotrophomonas rhizophila expresses a new enzyme for the synthesis of the compatible solute glucosylglycerol.

    PubMed

    Hagemann, Martin; Ribbeck-Busch, Kathrin; Klähn, Stephan; Hasse, Dirk; Steinbruch, Robert; Berg, Gabriele

    2008-09-01

    The rhizobacterium Stenotrophomonas rhizophila accumulates the compatible solutes glucosylglycerol (GG) and trehalose under salt stress conditions. The complete gene for the GG synthesis enzyme was cloned and sequenced. This enzyme from S. rhizophila represented a novel fusion protein composed of a putative C-terminal GG-phosphate synthase domain and an N-terminal putative GG-phosphate phosphatase domain, which was named GgpPS. A similar gene was cloned from Pseudomonas sp. strain OA146. The ggpPS gene was induced after a salt shock in S. rhizophila cells. After the salt-loaded cells reached stationary phase, the ggpPS mRNA content returned to the low level characteristic of the control cells, and GG was released into the medium. The complete ggpPS gene and a truncated version devoid of the phosphatase part were obtained as recombinant proteins. Enzyme activity tests revealed the expected abilities of the full-length protein to synthesize GG and the truncated GgpPS to synthesize GG-phosphate. However, dephosphorylation of GG-phosphate was detected only with the complete GgpPS protein. These enzyme activities were confirmed by complementation experiments using defined GG-defective mutants of the cyanobacterium Synechocystis sp. strain PCC 6803. Genes coding for proteins very similar to the newly identified fusion protein GgpPS for GG synthesis in S. rhizophila were found in genome sequences of related bacteria, where these genes are often linked to a gene coding for a transporter of the Mfs superfamily.

  11. The Plant-Associated Bacterium Stenotrophomonas rhizophila Expresses a New Enzyme for the Synthesis of the Compatible Solute Glucosylglycerol▿

    PubMed Central

    Hagemann, Martin; Ribbeck-Busch, Kathrin; Klähn, Stephan; Hasse, Dirk; Steinbruch, Robert; Berg, Gabriele

    2008-01-01

    The rhizobacterium Stenotrophomonas rhizophila accumulates the compatible solutes glucosylglycerol (GG) and trehalose under salt stress conditions. The complete gene for the GG synthesis enzyme was cloned and sequenced. This enzyme from S. rhizophila represented a novel fusion protein composed of a putative C-terminal GG-phosphate synthase domain and an N-terminal putative GG-phosphate phosphatase domain, which was named GgpPS. A similar gene was cloned from Pseudomonas sp. strain OA146. The ggpPS gene was induced after a salt shock in S. rhizophila cells. After the salt-loaded cells reached stationary phase, the ggpPS mRNA content returned to the low level characteristic of the control cells, and GG was released into the medium. The complete ggpPS gene and a truncated version devoid of the phosphatase part were obtained as recombinant proteins. Enzyme activity tests revealed the expected abilities of the full-length protein to synthesize GG and the truncated GgpPS to synthesize GG-phosphate. However, dephosphorylation of GG-phosphate was detected only with the complete GgpPS protein. These enzyme activities were confirmed by complementation experiments using defined GG-defective mutants of the cyanobacterium Synechocystis sp. strain PCC 6803. Genes coding for proteins very similar to the newly identified fusion protein GgpPS for GG synthesis in S. rhizophila were found in genome sequences of related bacteria, where these genes are often linked to a gene coding for a transporter of the Mfs superfamily. PMID:18586931

  12. Application of a magnetotactic bacterium, Stenotrophomonas sp. to the removal of Au(III) from contaminated wastewater with a magnetic separator.

    PubMed

    Song, Hui-Ping; Li, Xin-Gang; Sun, Jin-Sheng; Xu, Shi-Min; Han, Xu

    2008-06-01

    In this study, the feasibility of applying a magnetotactic bacterial isolate (MTB), Stenotrophomonas sp. to the removal of Au(III) was investigated. Biosorption experiments showed that Au(III) biosorption capacity exhibited no significant difference in the initial pH range of 1.0-5.5, while decreased more significantly in the initial pH range of 5.5-13.0. Langmuir isotherm indicated that the maximum Au(III) biosorption capacity of Stenotrophomonas sp. were 506, 369 and 308 mg g(-1) dry weight biomass at the initial pH values of 2.0, 7.0 and 12.0, respectively. Thiourea was proved to be an effective desorbent to recover Au from the MTB biomass and 91% Au adsorbed on the biomass could be recovered at equilibrium when the thiourea concentration was 0.8M. The magnetic separator developed by our research team used for separating Au loaded MTB biomass showed high separation efficiency, with 100% biomass removed at the magnetic intensity of 1200 Gs in 180 min. The analyses from FTIR and XRD further confirmed that the reduction of Au(III) to Au(0) by the reductants on the MTB biomass occurred, and the deposition of nano-crystal Au(0) particles, ranging from 24.7 to 31.4 nm, could be estimated on the biomass surface.

  13. 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

  14. Feeding strategies for the enhanced production of α-arbutin in the fed-batch fermentation of Xanthomonas maltophilia BT-112.

    PubMed

    Liu, Chunqiao; Zhang, Peng; Zhang, Shurong; Xu, Tao; Wang, Fang; Deng, Li

    2014-02-01

    To develop a cost-effective method for the enhanced production of α-arbutin using Xanthomonas maltophilia BT-112 as a biocatalyst, different fed-batch strategies such as constant feed rate fed-batch, constant hydroquinone (HQ) concentration fed-batch, exponential fed-batch and DO-control pulse fed-batch (DPFB) on α-arbutin production were investigated. The research results indicated that DPFB was an effective method for α-arbutin production. When fermentation with DO-control pulse feeding strategy to feed HQ and yeast extract was applied, the maximum concentrations of α-arbutin and cell dry weight were 61.7 and 4.21 g/L, respectively. The α-arbutin production was 394% higher than that of the control (batch culture) and the molar conversion yield of α-arbutin reached 94.5% based on the amount of HQ supplied (240 mM). Therefore, the results in this work provide an efficient and easily controlled method for industrial-scale production of α-arbutin.

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

    PubMed

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

    2016-03-01

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

  16. Treatment of Polymicrobial Osteomyelitis with Ceftolozane-Tazobactam: Case Report and Sensitivity Testing of Isolates

    PubMed Central

    Jolliff, Jeffrey C.; Joson, Jeremiah; Heidari, Arash; Johnson, Royce

    2016-01-01

    Stenotrophomonas maltophilia is an inherently multidrug resistant (MDR) opportunistic pathogen with many mechanisms of resistance. SENTRY studies reveal decreasing sensitivities of S. maltophilia to trimethoprim-sulfamethoxazole and fluoroquinolones. Ceftolozane-tazobactam (Zerbaxa, Merck & Co., Inc.) a novel intravenous combination agent of a third-generation cephalosporin and β-lactamase inhibitor was demonstrated to have in vitro activity against many Gram-positive, Gram-negative, and MDR organisms. Data for ceftolozane-tazobactam's use outside of Food and Drug Administration (FDA) approved indications has been limited thus far to two case reports which demonstrated its efficacy in pan-resistant Pseudomonas aeruginosa pneumonia. Herein, we describe the first published case of treatment of MDR S. maltophilia in polymicrobial osteomyelitis with long-term (>14 days) ceftolozane-tazobactam and metronidazole. Ceftolozane-tazobactam may offer a possible alternative for clinicians faced with limited options in the treatment of resistant pathogens including MDR S. maltophilia. PMID:27437155

  17. A Case of Sinusitis Caused by Schizophyllum Commune and Bacteria in Acute Myelocytic Leukemia.

    PubMed

    Yin, Xiuyun; Liang, Yuying; Zeng, Lijun; Chen, Shuiping

    2015-01-01

    Schizophyllum commune infections have been rarely reported. Here we reported a rare case of sinusitis in an acute myelocytic leukemia patient, who was co-infected by Escherichia coli, Stenotrophomonas maltophilia, and basidiomycetous fungi (Schizophyllum commune) in sinuses. Considering the in vitro and in vivo anti-fungal activity of voriconazole, it might be a good option to treat Schizophyllum commune infections when antifungal susceptibility testing is not available. When severe side effects occur, amphotericin B or itraconazole might be subsequent choice.

  18. Sensitivity of Aeromonas hydrophila carbapenemase to delta3-cephems: comparative study with other metallo-beta-lactamases.

    PubMed Central

    Felici, A; Perilli, M; Franceschini, N; Rossolini, G M; Galleni, M; Frere, J M; Oratore, A; Amicosante, G

    1997-01-01

    Ceftriaxone and ceftriaxone S-oxide behaved as inactivators against the metallo-beta-lactamase of Aeromonas hydrophila AE036 and as substrates for the zinc beta-lactamase produced by Bacillus cereus (569/H/9) and Stenotrophomonas maltophilia ULA 511. Moreover, RO 09-1428, a catechol-cephalosporin, was not recognized by the A. hydrophila enzyme. Panipenem, cephalosporin C, cephalosporin C-gamma-lactone, and loracarbef were substrates for the three studied beta-lactamases. PMID:9087509

  19. [Purification and characterization of a novel alpha-galactosidase from penicillium sp. F63 CGMCC1669].

    PubMed

    Mi, Shi-jun; Bai, Ying-guo; Meng, Kun; Wang, Ya-ru; Yao, Bin; Shi, Xiu-yun; Huang, Huo-qing; Zhang, Yu-hong; Shi, Peng-jun

    2007-02-01

    An a-galactosidase-producing fungus was screened out of 26 filamentous fungi isolated from soil by us. Phylogenetic analysis based on the alignment of 18S rDNA sequences, combined with the morphological identification, indicated that the strain F63 was a member of the genus Penicillium. The a-galactosidase from Penicillium sp. F63 was purified to apparent homogeneity by ammonium sulfate precipitation, ion-exchange and gel filtration chromatography. The molecular size of the purified enzyme is approximately 82kDa estimated by SDS-PAGE. The a-galactosidase has an optimum pH of 5.0 and an optimum temperature of 45 degrees C. The enzyme is stable between pH5.0 and 6.0 below 40 degrees C. The a-galactosidase activity is slightly inhibited by Ag+ , which is dissimilar to other a-galactosidases. Kinetic studies of the a-galactosidase showed that the Km and the Vmax for pNPG are 1.4mmol/L and 1.556mmol/L. min(-1) x mg- 1, respectively. The enzyme is able to degrade natural substrates such as melibiose, raffinose and stachyose but not galactose-containing polysaccharides. The alpha-galactosidase was identified by MALDI-TOF-MS and its inner peptides were sequenced by ESI-MS/MS. The results show that the a-galactosidase is a novel one.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

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

    PubMed

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

    2013-12-01

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

  2. Isolation and Characterization of α-Endosulfan Degrading Bacteria from the Microflora of Cockroaches.

    PubMed

    Ozdal, Murat; Ozdal, Ozlem Gur; Alguri, Omer Faruk

    2016-01-01

    Extensive applications of organochlorine pesticides like endosulfan have led to the contamination of soil and environments. Five different bacteria were isolated from cockroaches living in pesticide contaminated environments. According to morphological, physiological, biochemical properties, and total cellular fatty acid profile by Fatty Acid Methyl Esters (FAMEs), the isolates were identified as Pseudomonas aeruginosa G1, Stenotrophomonas maltophilia G2, Bacillus atrophaeus G3, Citrobacter amolonaticus G4 and Acinetobacter lwoffii G5. This is the first study on the bacterial flora of Blatta orientalis evaluated for the biodegradation of α-endosulfan. After 10 days of incubation, the biodegradation yields obtained from P. aeruginosa G1, S. maltophilia G2, B. atrophaeus G3, C. amolonaticus G4 and A. lwoffii G5 were 88.5% , 85.5%, 64.4%, 56.7% and 80.2%, respectively. As a result, these bacterial strains may be utilized for biodegradation of endosulfan polluted soil and environments.

  3. Isolation and Characterization of α-Endosulfan Degrading Bacteria from the Microflora of Cockroaches.

    PubMed

    Ozdal, Murat; Ozdal, Ozlem Gur; Alguri, Omer Faruk

    2016-01-01

    Extensive applications of organochlorine pesticides like endosulfan have led to the contamination of soil and environments. Five different bacteria were isolated from cockroaches living in pesticide contaminated environments. According to morphological, physiological, biochemical properties, and total cellular fatty acid profile by Fatty Acid Methyl Esters (FAMEs), the isolates were identified as Pseudomonas aeruginosa G1, Stenotrophomonas maltophilia G2, Bacillus atrophaeus G3, Citrobacter amolonaticus G4 and Acinetobacter lwoffii G5. This is the first study on the bacterial flora of Blatta orientalis evaluated for the biodegradation of α-endosulfan. After 10 days of incubation, the biodegradation yields obtained from P. aeruginosa G1, S. maltophilia G2, B. atrophaeus G3, C. amolonaticus G4 and A. lwoffii G5 were 88.5% , 85.5%, 64.4%, 56.7% and 80.2%, respectively. As a result, these bacterial strains may be utilized for biodegradation of endosulfan polluted soil and environments. PMID:27281995

  4. 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.

  5. 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.

  6. Mutualistic growth of the sulfate-reducer Desulfovibrio vulgaris Hildenborough with different carbohydrates.

    PubMed

    Santana, M M; Portillo, M C; Gonzalez, J M

    2012-01-01

    Desulfovibrio vulgaris Hildenborough genome presents a phosphotransferase system putatively involved in the transport of carbohydrates. However, utilization of sugars by this sulfate-reducing bacterium has never been reported. Herein, we have observed proliferation of D. vulgaris Hildenborough with some carbohydrates, in mutualism with Stenotrophomonas maltophilia, a non-fermentative, gram-negative gammaproteobacterium, or Microbacterium, a gram-positive actinobacterium. These results suggest the importance of feedback interactions between different heterotrophic bacterial species including the alternative for D. vulgaris of exploiting additional organic resources and novel habitats. Thus, D. vulgaris strongly participates in the mineralization of carbohydrates both in complex natural and artificial systems.

  7. 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.

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

    PubMed

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

    2013-11-01

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

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

    PubMed Central

    van der Kooij, Dick

    2013-01-01

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

  10. Nontuberculous mycobacteria, fungi, and opportunistic pathogens in unchlorinated drinking water in The Netherlands.

    PubMed

    van der Wielen, Paul W J J; van der Kooij, Dick

    2013-02-01

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

  11. 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

  12. Bacterial degradation of naproxen--undisclosed pollutant in the environment.

    PubMed

    Wojcieszyńska, Danuta; Domaradzka, Dorota; Hupert-Kocurek, Katarzyna; Guzik, Urszula

    2014-12-01

    The presence of non-steroidal anti-inflammatory drugs (NSAIDs) in the environment is an emerging problem due to their potential influence on human health and biocenosis. This is the first report on the biotransformation of naproxen, a polycyclic NSAID, by a bacterial strain. Stenotrophomonas maltophilia KB2 transformed naproxen within 35 days with about 28% degradation efficiency. Under cometabolic conditions with glucose or phenol as a carbon source degradation efficiency was 78% and 40%, respectively. Moreover, in the presence of naproxen phenol monooxygenase, naphthalene dioxygenase, hydroxyquinol 1,2-dioxygenase and gentisate 1,2-dioxygenase were induced. This suggests that degradation of naproxen occurs by its hydroxylation to 5,7,8-trihydroxynaproxen, an intermediate that can be cleaved by hydroxyquinol 1,2-dioxygenase. The cleavage product is probably further oxidatively cleaved by gentisate 1,2-dioxygenase. The obtained results provide the basis for the use of cometabolic systems in the bioremediation of polycyclic NSAID-contaminated environments.

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

    PubMed

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

    2014-01-01

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

  14. 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.

  15. A novel isoquinoline alkaloid, DD-carboxypeptidase inhibitor, with antibacterial activity isolated from Streptomyces sp. 8812. Part I: Taxonomy, fermentation, isolation and biological activities.

    PubMed

    Solecka, Jolanta; Rajnisz, Aleksandra; Laudy, Agnieszka E

    2009-10-01

    A novel isoquinoline alkaloid of molecular formula C10H9NO4, labeled JS-1, was isolated from the culture broth of Streptomyces sp. 8812. It was purified by acetone protein precipitation from the culture supernatant, followed by anion exchange and C18 RP HPLC columns. JS-1 is an inhibitor of exocellular DD-carboxypeptidases/transpeptidases (DD-peptidases) 64-575 II from Saccharopolyspora erythraea 64-575 II, and R39 from Actinomadura R39. JS-1 exhibits activity against Gram-negative bacteria, such as Bordetella bronchiseptica, Stenotrophomonas maltophilia, Proteus vulgaris, P. mirabilis, Burkholderia cepacia and Acinetobacter baumanii, with MIC values 10-160 microg ml(-1), and against Gram-positive bacteria, such as Staphylococcus aureus, with MIC values 40-206 microg ml(-1).

  16. Tsunami lung.

    PubMed

    Inoue, Yoshihiro; Fujino, Yasuhisa; Onodera, Makoto; Kikuchi, Satoshi; Shozushima, Tatsuyori; Ogino, Nobuyoshi; Mori, Kiyoshi; Oikawa, Hirotaka; Koeda, Yorihiko; Ueda, Hironobu; Takahashi, Tomohiro; Terui, Katsutoshi; Nakadate, Toshihide; Aoki, Hidehiko; Endo, Shigeatsu

    2012-04-01

    We encountered three cases of lung disorders caused by drowning in the recent large tsunami that struck following the Great East Japan Earthquake. All three were females, and two of them were old elderly. All segments of both lungs were involved in all the three patients, necessitating ICU admission and endotracheal intubation and mechanical ventilation. All three died within 3 weeks. In at least two cases, misswallowing of oil was suspected from the features noted at the time of the detection. Sputum culture for bacteria yielded isolation of Stenotrophomonas maltophilia, Legionella pneumophila, Burkholderia cepacia, and Pseudomonas aeruginosa. The cause of tsunami lung may be a combination of chemical induced pneumonia and bacterial pneumonia.

  17. A case of unusual Gram-negative bacilli septic arthritis in an immunocompetent patient.

    PubMed

    Chiu, Li Qi; Wang, Wilson

    2013-08-01

    The Gram-negative bacilli Acinetobacter baumannii, Burkholderia cepacia, Ochrobactrum anthropi, Pseudomonas mendocina, Ralstonia spp., Serratia marcescens and Stenotrophomonas maltophilia are ubiquitous environmental organisms of low virulence, and do not usually cause illness in immunocompetent hosts. We report a case of multiple concurrent opportunistic Gram-negative bacilli causing septic arthritis in a healthy patient following trauma to the knee. Repeated operations, including arthroscopy, arthrotomy and debridement, were required before tissue cultures became negative. The patient also required an extended duration of intravenous and oral antibiotic treatment before he was discharged. Gram-negative bacillary septic arthritis is an uncommon but significant condition that requires repeated debridement and washouts in order to achieve bacterial eradication. This case report highlights the importance of an awareness of the external environment at the time of injury, as it impacts the type of organisms causing the infection, and consequently, the choice of empiric antibiotics required for successful treatment.

  18. An L-glucitol oxidizing dehydrogenase from Bradyrhizobium japonicum USDA 110 for production of D-sorbose with enzymatic or electrochemical cofactor regeneration.

    PubMed

    Gauer, Sabrina; Wang, Zhijie; Otten, Harm; Etienne, Mathieu; Bjerrum, Morten Jannik; Lo Leggio, Leila; Walcarius, Alain; Giffhorn, Friedrich; Kohring, Gert-Wieland

    2014-04-01

    A gene in Bradyrhizobium japonicum USDA 110, annotated as a ribitol dehydrogenase (RDH), had 87 % sequence identity (97 % positives) to the N-terminal 31 amino acids of an L-glucitol dehydrogenase from Stenotrophomonas maltophilia DSMZ 14322. The 729-bp long RDH gene coded for a protein consisting of 242 amino acids with a molecular mass of 26.1 kDa. The heterologously expressed protein not only exhibited the main enantio selective activity with D-glucitol oxidation to D-fructose but also converted L-glucitol to D-sorbose with enzymatic cofactor regeneration and a yield of 90 %. The temperature stability and the apparent K m value for L-glucitol oxidation let the enzyme appear as a promising subject for further improvement by enzyme evolution. We propose to rename the enzyme from the annotated RDH gene (locus tag bll6662) from B. japonicum USDA as a D-sorbitol dehydrogenase (EC 1.1.1.14).

  19. [The present status, counter-measures and new trends on burn infection].

    PubMed

    Xiao, Guang-xia

    2007-04-01

    In recent fifty years, Pseudomonas aeruginosa and Staphylococcus aureus were continuously the predominant in burn infections, the only change seen was a rapid increase in their drug-resistance. Under the pressure of antibiotics, Some opportunistic bacteria that were resistant to all available antibiotics emerged, such as Acinetobacter baumanii and Maltophilia stenotrophomonas. For critically burn patients, basing on early surgical intervention, early and short-term use of broad-spectrum antibiotic is advisable, and it may control the infection promptly, prevent further inflammatory reaction, as well as minimize the emergence of antibacterial resistance. To control infections due to pandrug-resistant bacteria, cyclic use of some old antibiotics may be helpful. In dealing with severe infection, a combination of anti-pathogen and anti-inflammatory reaction measures should be considered. PMID:17649876

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

    PubMed

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

    2006-12-15

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

  1. Dynamics of Seed-Borne Rice Endophytes on Early Plant Growth Stages

    PubMed Central

    Hardoim, Pablo R.; Hardoim, Cristiane C. P.; van Overbeek, Leonard S.; van Elsas, Jan Dirk

    2012-01-01

    Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However, still little is known on the source of established endophytes as well as on how plants select specific microbial communities to establish associations. Here, we used cultivation-dependent and -independent approaches to assess the endophytic bacterrial community of surface-sterilized rice seeds, encompassing two consecutive rice generations. We isolated members of nine bacterial genera. In particular, organisms affiliated with Stenotrophomonas maltophilia and Ochrobactrum spp. were isolated from both seed generations. PCR-based denaturing gradient gel electrophoresis (PCR-DGGE) of seed-extracted DNA revealed that approximately 45% of the bacterial community from the first seed generation was found in the second generation as well. In addition, we set up a greenhouse experiment to investigate abiotic and biotic factors influencing the endophytic bacterial community structure. PCR-DGGE profiles performed with DNA extracted from different plant parts showed that soil type is a major effector of the bacterial endophytes. Rice plants cultivated in neutral-pH soil favoured the growth of seed-borne Pseudomonas oryzihabitans and Rhizobium radiobacter, whereas Enterobacter-like and Dyella ginsengisoli were dominant in plants cultivated in low-pH soil. The seed-borne Stenotrophomonas maltophilia was the only conspicuous bacterial endophyte found in plants cultivated in both soils. Several members of the endophytic community originating from seeds were observed in the rhizosphere and surrounding soils. Their impact on the soil community is further discussed. PMID:22363438

  2. Dynamics of seed-borne rice endophytes on early plant growth stages.

    PubMed

    Hardoim, Pablo R; Hardoim, Cristiane C P; van Overbeek, Leonard S; van Elsas, Jan Dirk

    2012-01-01

    Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However, still little is known on the source of established endophytes as well as on how plants select specific microbial communities to establish associations. Here, we used cultivation-dependent and -independent approaches to assess the endophytic bacterrial community of surface-sterilized rice seeds, encompassing two consecutive rice generations. We isolated members of nine bacterial genera. In particular, organisms affiliated with Stenotrophomonas maltophilia and Ochrobactrum spp. were isolated from both seed generations. PCR-based denaturing gradient gel electrophoresis (PCR-DGGE) of seed-extracted DNA revealed that approximately 45% of the bacterial community from the first seed generation was found in the second generation as well. In addition, we set up a greenhouse experiment to investigate abiotic and biotic factors influencing the endophytic bacterial community structure. PCR-DGGE profiles performed with DNA extracted from different plant parts showed that soil type is a major effector of the bacterial endophytes. Rice plants cultivated in neutral-pH soil favoured the growth of seed-borne Pseudomonas oryzihabitans and Rhizobium radiobacter, whereas Enterobacter-like and Dyella ginsengisoli were dominant in plants cultivated in low-pH soil. The seed-borne Stenotrophomonas maltophilia was the only conspicuous bacterial endophyte found in plants cultivated in both soils. Several members of the endophytic community originating from seeds were observed in the rhizosphere and surrounding soils. Their impact on the soil community is further discussed.

  3. Dynamics of seed-borne rice endophytes on early plant growth stages.

    PubMed

    Hardoim, Pablo R; Hardoim, Cristiane C P; van Overbeek, Leonard S; van Elsas, Jan Dirk

    2012-01-01

    Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However, still little is known on the source of established endophytes as well as on how plants select specific microbial communities to establish associations. Here, we used cultivation-dependent and -independent approaches to assess the endophytic bacterrial community of surface-sterilized rice seeds, encompassing two consecutive rice generations. We isolated members of nine bacterial genera. In particular, organisms affiliated with Stenotrophomonas maltophilia and Ochrobactrum spp. were isolated from both seed generations. PCR-based denaturing gradient gel electrophoresis (PCR-DGGE) of seed-extracted DNA revealed that approximately 45% of the bacterial community from the first seed generation was found in the second generation as well. In addition, we set up a greenhouse experiment to investigate abiotic and biotic factors influencing the endophytic bacterial community structure. PCR-DGGE profiles performed with DNA extracted from different plant parts showed that soil type is a major effector of the bacterial endophytes. Rice plants cultivated in neutral-pH soil favoured the growth of seed-borne Pseudomonas oryzihabitans and Rhizobium radiobacter, whereas Enterobacter-like and Dyella ginsengisoli were dominant in plants cultivated in low-pH soil. The seed-borne Stenotrophomonas maltophilia was the only conspicuous bacterial endophyte found in plants cultivated in both soils. Several members of the endophytic community originating from seeds were observed in the rhizosphere and surrounding soils. Their impact on the soil community is further discussed. PMID:22363438

  4. Effects of pathology dyes on Raman bone spectra

    PubMed Central

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

    2013-01-01

    Abstract. We report an overlooked source of artifacts for clinical specimens, where unexpected and normally negligible contaminants can skew the interpretation of results. During an ongoing study of bone fragments from diabetic osteomyelitis, strong Raman signatures were found, which did not correspond with normal bone mineral or matrix. In a bone biopsy from the calcaneus of a patient affected by diabetic osteomyelitis, Raman microspectroscopic analysis revealed regions with both abnormal mineral and degraded collagen in addition to normal bone. Additional bands indicated a pathological material. Stenotrophomonas maltophilia was identified in the wound culture by independent microbiologic examination. We initially assigned the unusual bands to xanthomonadin, a bacterial pigment from S. maltophilia. However, the same bands were also found more than a year later on a second specimen that had been noticeably contaminated with pathology marking dye. Drop deposition/Raman spectroscopy of commonly used pathology dyes revealed that a blue tissue-marking dye was responsible for the unusual bands in both specimens, even in the first specimen where there was no visible evidence of contamination. PMID:23640079

  5. Essential Oil from Origanum vulgare Completely Inhibits the Growth of Multidrug-Resistant Cystic Fibrosis Pathogens.

    PubMed

    Pesavento, Giovanna; Maggini, Valentina; Maida, Isabel; Lo Nostro, Antonella; Calonico, Carmela; Sassoli, Chiara; Perrin, Elena; Fondi, Marco; Mengoni, Alessio; Chiellini, Carolina; Vannacci, Alfredo; Gallo, Eugenia; Gori, Luigi; Bogani, Patrizia; Bilia, Anna Rita; Campana, Silvia; Ravenni, Novella; Dolce, Daniela; Firenzuoli, Fabio; Fani, Renato

    2016-06-01

    Essential oils (EOs) are known to inhibit the growth of a wide range of microorganisms. Particularly interesting is the possible use of EOs to treat multidrug-resistant cystic fibrosis (CF) pathogens. We tested the essential oil (EO) from Origanum vulgare for in vitro antimicrobial activity, against three of the major human opportunistic pathogens responsible for respiratory infections in CF patients; these are methicillin-resistant Staphylococcus aureus, Stenotrophomonas maltophilia and Achromobacter xylosoxidans. Antibiotic susceptibility of each strain was previously tested by the standard disk diffusion method. Most strains were resistant to multiple antibiotics and could be defined as multi-drug-resistant (MDR). The antibacterial activity of O. vulgare EO (OEO) against a panel of 59 bacterial strains was evaluated, with MIC and MBC determined at 24, 48 and 72 hours by a microdilution method. The OEO was effective against all tested strains, although to a different extent. The MBC and MIC of OEO for S. aureus strains were either lower or equal to 0.50%, v/v, for A. xylosoxidans strains were lower or equal to 1% and 0.50%, v/v, respectively; and for S. maltophilia strains were lower or equal to 0.25%, v/v. The results from this study suggest that OEO might exert a role as an antimicrobial in the treatment of CF infections. PMID:27534136

  6. Septicaemia secondary to infection by Corynebacterium macginleyi in an Indian python (Python molurus).

    PubMed

    Martínez, Jorge; Segura, Pablo; García, David; Aduriz, Gorka; Ibabe, José C; Peris, Bernardo; Corpa, Juan M

    2006-09-01

    A seven-year-old female Indian python (Python molurus) weighing about 35kg was euthanased after several clinical episodes of stomatitis, pneumonia, ophthalmitis and dystocia over a period of four years. The animal had been maintained in a terrarium in a circus truck at an adequate temperature. During shows, however, the snake was considered to be exposed to stressful conditions for several hours at a time at low temperatures and with noise and bright lights. A post-mortem examination indicated ulcerative stomatitis, osteomyelitis, severe pneumonia and numerous granulomata and multifocal necrosis in stomach and spleen. Corynebacterium macginleyi was isolated in pure culture from the ulcerative stomatitis, and mixed with Stenotrophomonas maltophilia from the lungs and spleen. The findings indicated that the snake had died from a septicaemic process caused by C. macginleyi, probably originating from the stomatitis. The role of S. maltophilia as a secondary agent is discussed. The stress of the circus show and poor husbandry may have predisposed the animal to infection and septicaemia. This is the first report of C. macginleyi causing disease in a snake.

  7. Effects of pathology dyes on Raman bone spectra

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  8. Revisited distribution of nonfermenting Gram-negative bacilli clinical isolates.

    PubMed

    Jacquier, H; Carbonnelle, E; Corvec, S; Illiaquer, M; Le Monnier, A; Bille, E; Zahar, J R; Beretti, J L; Jauréguy, F; Fihman, V; Tankovic, J; Cattoir, V

    2011-12-01

    Nonfermenting Gram-negative bacilli (NF-GNB) are ubiquitous environmental opportunistic bacteria frequently misidentified by conventional phenotypic methods. The aim of this study was to determine the distribution of NF-GNB species by 16 S rRNA gene sequencing (used as reference method) and to compare performances of biochemical tests and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). From nine French hospitals, 188 NF-GNB isolates (except P. aeruginosa and A. baumannii) were prospectively collected from 187 clinical samples between December 2008 and May 2009. By using the genotypic approach, 173 (92%) and 188 (100%) isolates were identified to the species and genus level, respectively. They covered 35 species and 20 genera, with a predominance of Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Pseudomonas putida group bacteria. Of the 173 species-level identified strains, concordant identification to the species-level was obtained for 75.1%, 83% and 88.9% of isolates with API 20 NE strip, the VITEK-2 (ID-GN card) system and MALDI-TOF-MS, respectively. By excluding S. maltophilia isolates accurately identified by the three methods, genus-level identification was much higher for MALDI-TOF-MS (92.9%), compared with API 20 NE and VITEK-2 (76.2% and 80.8%, respectively). In conclusion, MALDI-TOF-MS represents a rapid, inexpensive, and accurate tool for routine identification of NF-GNB in human clinical samples.

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

    NASA Astrophysics Data System (ADS)

    Baker, Paul W.; Leff, Laura G.

    2006-01-01

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

  10. Pathogen and autoantigen homologous regions within the cystic fibrosis transmembrane conductance regulator (CFTR) protein suggest an autoimmune treatable component of cystic fibrosis.

    PubMed

    Carter, Chris J

    2011-07-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel provides the glutathione and hypochlorous acid necessary for bactericidal/viricidal actions. CFTR mutations block these effects, diminishing pathogen defence and allowing extracellular pathogen accumulation, where antibody encounter is likely. KEGG pathway analysis of the CFTR interactome shows that CFTR is involved in pathogen entry pathways and immune defence as well as in pathways relevant to comorbid conditions (diabetes, cardiomyopathies and sexual organ development). Pseudomonas aeruginosa and Staphylococcus aureus infections decrease the lifespan of cystic fibrosis patients and Stenotrophomonas maltophilia colonization is increased. Autoantibodies, targeting myeloperoxidase, the bactericidal/permeability-increasing protein and calgranulin may further compromise pathogen defence. Short consensus sequences, within immunogenic extracellular regions of the CFTR protein, are homologous to proteins expressed by P. aeruginosa, S. aureus and S. maltophilia, and to several autoantigens, with a universal overlap between autoantigen/pathogen/CFTR consensi. Antibodies to pathogens are thus likely responsible for the creation of these autoantibodies, which, with pathogen antibodies, may target the CFTR protein acting as antagonists, further compromising its function. This creates a feedforward cycle, diminishing the function of the CFTR protein and increasing the probability of pathogen accumulation and antibody production at every turn. Interruption of this cycle by antibody adsorption or immunosuppressant therapy may be beneficial in cystic fibrosis.

  11. Bacterial stimulation of copper phytoaccumulation by bioaugmentation with rhizosphere bacteria.

    PubMed

    Andreazza, Robson; Okeke, Benedict C; Lambais, Márcio Rodrigues; Bortolon, Leandro; de Melo, George Wellington Bastos; Camargo, Flávio Anastácio de Oliveira

    2010-11-01

    Copper contaminated areas pose environmental health risk to living organisms. Remediation processes are thus required for both crop production and industrial activities. This study employed bioaugmentation with copper resistant bacteria to improve phytoremediation of vineyard soils and copper mining waste contaminated with high copper concentrations. Oatmeal plant (Avena sativa L.) was used for copper phytoextraction. Three copper resistant bacterial isolates from oatmeal rhizosphere (Pseudomonas putida A1; Stenotrophomonas maltophilia A2 and Acinetobacter calcoaceticus A6) were used for the stimulation of copper phytoextraction. Two long-term copper contaminated vineyard soils (Mollisol and Inceptisol) and copper mining waste from Southern Brazil were evaluated. Oatmeal plants substantially extracted copper from vineyard soils and copper mining waste. As much as 1549 mg of Cu kg⁻¹ dry mass was extracted from plants grown in Inceptisol soil. The vineyard Mollisol copper uptake (55 mg Cu kg⁻¹ of dry mass) in the shoots was significantly improved upon inoculation of oatmeal plants with isolate A2 (128 mg of Cu kg⁻¹ of shoot dry mass). Overall oatmeal plant biomass displayed higher potential of copper phytoextraction with inoculation of rhizosphere bacteria in vineyard soil to the extent that 404 and 327 g ha⁻¹ of copper removal were respectively observed in vineyard Mollisol bioaugmented with isolate A2 (S. maltophilia) and isolate A6 (A. calcoaceticus). Results suggest potential application of bacterial stimulation of phytoaccumulation of copper for biological removal of copper from contaminated areas.

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

    PubMed

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

    2015-02-01

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

  13. Effects of pathology dyes on Raman bone spectra.

    PubMed

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

    2013-05-01

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

  14. Essential Oil from Origanum vulgare Completely Inhibits the Growth of Multidrug-Resistant Cystic Fibrosis Pathogens.

    PubMed

    Pesavento, Giovanna; Maggini, Valentina; Maida, Isabel; Lo Nostro, Antonella; Calonico, Carmela; Sassoli, Chiara; Perrin, Elena; Fondi, Marco; Mengoni, Alessio; Chiellini, Carolina; Vannacci, Alfredo; Gallo, Eugenia; Gori, Luigi; Bogani, Patrizia; Bilia, Anna Rita; Campana, Silvia; Ravenni, Novella; Dolce, Daniela; Firenzuoli, Fabio; Fani, Renato

    2016-06-01

    Essential oils (EOs) are known to inhibit the growth of a wide range of microorganisms. Particularly interesting is the possible use of EOs to treat multidrug-resistant cystic fibrosis (CF) pathogens. We tested the essential oil (EO) from Origanum vulgare for in vitro antimicrobial activity, against three of the major human opportunistic pathogens responsible for respiratory infections in CF patients; these are methicillin-resistant Staphylococcus aureus, Stenotrophomonas maltophilia and Achromobacter xylosoxidans. Antibiotic susceptibility of each strain was previously tested by the standard disk diffusion method. Most strains were resistant to multiple antibiotics and could be defined as multi-drug-resistant (MDR). The antibacterial activity of O. vulgare EO (OEO) against a panel of 59 bacterial strains was evaluated, with MIC and MBC determined at 24, 48 and 72 hours by a microdilution method. The OEO was effective against all tested strains, although to a different extent. The MBC and MIC of OEO for S. aureus strains were either lower or equal to 0.50%, v/v, for A. xylosoxidans strains were lower or equal to 1% and 0.50%, v/v, respectively; and for S. maltophilia strains were lower or equal to 0.25%, v/v. The results from this study suggest that OEO might exert a role as an antimicrobial in the treatment of CF infections.

  15. Bacteria associated with Amblyomma cajennense tick eggs

    PubMed Central

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

    2015-01-01

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

  16. Complete genome sequence of a psychotrophic Pseudarthrobacter sulfonivorans strain Ar51 (CGMCC 4.7316), a novel crude oil and multi benzene compounds degradation strain.

    PubMed

    Zhang, Hua; Sun, Haili; Yang, Ruiqi; Li, Shuyan; Zhou, Meng; Gao, Tianpeng; An, Lizhe; Chen, Ximing; Dyson, Paul

    2016-08-10

    Pseudarthrobacter sulfonivorans strain Ar51, a psychotrophic bacterium isolated from the Tibet permafrost of China, can degrade crude oil and multi benzene compounds efficiently in low temperature. Here we report the complete genome sequence of this bacterium. The complete genome sequence of Pseudarthrobacter sulfonivorans strain Ar51, consisting of a cycle chromosome with a size of 5.04Mbp and a cycle plasmid with a size of 12.39kbp. The availability of this genome sequence allows us to investigate the genetic basis of crude oil degradation and adaptation to growth in a nutrient-poor permafrost environment. PMID:27245144

  17. Longitudinal Metagenomic Analysis of Hospital Air Identifies Clinically Relevant Microbes

    PubMed Central

    King, Paula; Pham, Long K.; Waltz, Shannon; Sphar, Dan; Yamamoto, Robert T.; Conrad, Douglas; Taplitz, Randy; Torriani, Francesca

    2016-01-01

    We describe the sampling of sixty-three uncultured hospital air samples collected over a six-month period and analysis using shotgun metagenomic sequencing. Our primary goals were to determine the longitudinal metagenomic variability of this environment, identify and characterize genomes of potential pathogens and determine whether they are atypical to the hospital airborne metagenome. Air samples were collected from eight locations which included patient wards, the main lobby and outside. The resulting DNA libraries produced 972 million sequences representing 51 gigabases. Hierarchical clustering of samples by the most abundant 50 microbial orders generated three major nodes which primarily clustered by type of location. Because the indoor locations were longitudinally consistent, episodic relative increases in microbial genomic signatures related to the opportunistic pathogens Aspergillus, Penicillium and Stenotrophomonas were identified as outliers at specific locations. Further analysis of microbial reads specific for Stenotrophomonas maltophilia indicated homology to a sequenced multi-drug resistant clinical strain and we observed broad sequence coverage of resistance genes. We demonstrate that a shotgun metagenomic sequencing approach can be used to characterize the resistance determinants of pathogen genomes that are uncharacteristic for an otherwise consistent hospital air microbial metagenomic profile. PMID:27482891

  18. Volatiles of bacterial antagonists inhibit mycelial growth of the plant pathogen Rhizoctonia solani.

    PubMed

    Kai, Marco; Effmert, Uta; Berg, Gabriele; Piechulla, Birgit

    2007-05-01

    Bacterial antagonists are bacteria that negatively affect the growth of other organisms. Many antagonists inhibit the growth of fungi by various mechanisms, e.g., secretion of lytic enzymes, siderophores and antibiotics. Such inhibition of fungal growth may indirectly support plant growth. Here, we demonstrate that small organic volatile compounds (VOCs) emitted from bacterial antagonists negatively influence the mycelial growth of the soil-borne phytopathogenic fungus Rhizoctonia solani Kühn. Strong inhibitions (99-80%) under the test conditions were observed with Stenotrophomonas maltophilia R3089, Serratia plymuthica HRO-C48, Stenotrophomonas rhizophila P69, Serratia odorifera 4Rx13, Pseudomonas trivialis 3Re2-7, S. plymuthica 3Re4-18 and Bacillus subtilis B2g. Pseudomonas fluorescens L13-6-12 and Burkholderia cepacia 1S18 achieved 30% growth reduction. The VOC profiles of these antagonists, obtained through headspace collection and analysis on GC-MS, show different compositions and complexities ranging from 1 to almost 30 compounds. Most volatiles are species-specific, but overlapping volatile patterns were found for Serratia spp. and Pseudomonas spp. Many of the bacterial VOCs could not be identified for lack of match with mass-spectra of volatiles in the databases. PMID:17180381

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

    SciTech Connect

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

    2000-03-01

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

  20. Prevalence of Multidrug-Resistant Bacteria on Fresh Vegetables Collected from Farmers' Markets in Connecticut.

    PubMed

    Karumathil, Deepti Prasad; Yin, Hsin-Bai; Kollanoor-Johny, Anup; Venkitanarayanan, Kumar

    2016-08-01

    This study determined the prevalence of multidrug-resistant (MDR) Acinetobacter baumannii on fresh vegetables collected from farmers' markets in Connecticut. One hundred samples each of fresh carrots, potatoes, and lettuce were sampled and streaked on selective media, namely Leeds Acinetobacter and MDR Acinetobacter agars. All morphologically different colonies from MDR Acinetobacter agar were identified by using Gram staining, biochemical tests, and PCR. In addition, susceptibility of the isolates to 10 antibiotics commonly used in humans, namely imipenem, ceftriaxone, cefepime, minocycline, erythromycin, colistin-sulfate, streptomycin, neomycin, doxycycline, and rifampin was determined by using an antibiotic disk diffusion assay. The results revealed that only two samples of potato and one sample of lettuce yielded A. baumannii. In addition, all carrot samples were found to be negative for the organism. However, several other opportunistic, MDR human pathogens, such as Burkholderia cepacia (1% potatoes, 5% carrots, and none in lettuce), Stenotrophomonas maltophilia (6% potatoes, 2% lettuce, and none in carrots), and Pseudomonas luteola (9% potatoes, 3% carrots, and none in lettuce) were recovered from the vegetables. Antibiotic susceptibility screening of the isolates revealed high resistance rates for the following: ceftriaxone (6 of 6), colistin-sulfate (5 of 6), erythromycin (5 of 6), and streptomycin (4 of 6) in B. cepacia; colistin-sulfate (11 of 11) and imipenem (10 of 11) in P. luteola; colistin-sulfate (8 of 8), ceftriaxone (8 of 8), cefepime (7 of 8), erythromycin (5 of 8), and imipenem (4 of 8) in S. maltophilia; and imipenem (3 of 3), ceftriaxone (3 of 3), erythromycin (3 of 3), and streptomycin (3 of 3) in A. baumannii. The results revealed the presence of MDR bacteria, including human pathogens on fresh produce, thereby highlighting the potential health risk in consumers, especially those with a compromised immune system.

  1. Prevalence of Multidrug-Resistant Bacteria on Fresh Vegetables Collected from Farmers' Markets in Connecticut.

    PubMed

    Karumathil, Deepti Prasad; Yin, Hsin-Bai; Kollanoor-Johny, Anup; Venkitanarayanan, Kumar

    2016-08-01

    This study determined the prevalence of multidrug-resistant (MDR) Acinetobacter baumannii on fresh vegetables collected from farmers' markets in Connecticut. One hundred samples each of fresh carrots, potatoes, and lettuce were sampled and streaked on selective media, namely Leeds Acinetobacter and MDR Acinetobacter agars. All morphologically different colonies from MDR Acinetobacter agar were identified by using Gram staining, biochemical tests, and PCR. In addition, susceptibility of the isolates to 10 antibiotics commonly used in humans, namely imipenem, ceftriaxone, cefepime, minocycline, erythromycin, colistin-sulfate, streptomycin, neomycin, doxycycline, and rifampin was determined by using an antibiotic disk diffusion assay. The results revealed that only two samples of potato and one sample of lettuce yielded A. baumannii. In addition, all carrot samples were found to be negative for the organism. However, several other opportunistic, MDR human pathogens, such as Burkholderia cepacia (1% potatoes, 5% carrots, and none in lettuce), Stenotrophomonas maltophilia (6% potatoes, 2% lettuce, and none in carrots), and Pseudomonas luteola (9% potatoes, 3% carrots, and none in lettuce) were recovered from the vegetables. Antibiotic susceptibility screening of the isolates revealed high resistance rates for the following: ceftriaxone (6 of 6), colistin-sulfate (5 of 6), erythromycin (5 of 6), and streptomycin (4 of 6) in B. cepacia; colistin-sulfate (11 of 11) and imipenem (10 of 11) in P. luteola; colistin-sulfate (8 of 8), ceftriaxone (8 of 8), cefepime (7 of 8), erythromycin (5 of 8), and imipenem (4 of 8) in S. maltophilia; and imipenem (3 of 3), ceftriaxone (3 of 3), erythromycin (3 of 3), and streptomycin (3 of 3) in A. baumannii. The results revealed the presence of MDR bacteria, including human pathogens on fresh produce, thereby highlighting the potential health risk in consumers, especially those with a compromised immune system. PMID:27497135

  2. Emergence of imipenem-resistant gram-negative bacilli in intestinal flora of intensive care patients.

    PubMed

    Armand-Lefèvre, Laurence; Angebault, Cécile; Barbier, François; Hamelet, Emilie; Defrance, Gilles; Ruppé, Etienne; Bronchard, Régis; Lepeule, Raphaël; Lucet, Jean-Christophe; El Mniai, Assiya; Wolff, Michel; Montravers, Philippe; Plésiat, Patrick; Andremont, Antoine

    2013-03-01

    Intestinal flora contains a reservoir of Gram-negative bacilli (GNB) resistant to cephalosporins, which are potentially pathogenic for intensive care unit (ICU) patients; this has led to increasing use of carbapenems. The emergence of carbapenem resistance is a major concern for ICUs. Therefore, in this study, we aimed to assess the intestinal carriage of imipenem-resistant GNB (IR-GNB) in intensive care patients. For 6 months, 523 consecutive ICU patients were screened for rectal IR-GNB colonization upon admission and weekly thereafter. The phenotypes and genotypes of all isolates were determined, and a case control study was performed to identify risk factors for colonization. The IR-GNB colonization rate increased regularly from 5.6% after 1 week to 58.6% after 6 weeks in the ICU. In all, 56 IR-GNB strains were collected from 50 patients: 36 Pseudomonas aeruginosa strains, 12 Stenotrophomonas maltophilia strains, 6 Enterobacteriaceae strains, and 2 Acinetobacter baumannii strains. In P. aeruginosa, imipenem resistance was due to chromosomally encoded resistance (32 strains) or carbapenemase production (4 strains). In the Enterobacteriaceae strains, resistance was due to AmpC cephalosporinase and/or extended-spectrum β-lactamase production with porin loss. Genomic comparison showed that the strains were highly diverse, with 8 exceptions (4 VIM-2 carbapenemase-producing P. aeruginosa strains, 2 Klebsiella pneumoniae strains, and 2 S. maltophilia strains). The main risk factor for IR-GNB colonization was prior imipenem exposure. The odds ratio for colonization was already as high as 5.9 (95% confidence interval [95% CI], 1.5 to 25.7) after 1 to 3 days of exposure and increased to 7.8 (95% CI, 2.4 to 29.8) thereafter. In conclusion, even brief exposure to imipenem is a major risk factor for IR-GNB carriage.

  3. 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

  4. Identification and susceptibility to multipurpose disinfectant solutions of bacteria isolated from contact lens storage cases of patients with corneal infiltrative events.

    PubMed

    Kilvington, Simon; Shovlin, Joseph; Nikolic, Marina

    2013-12-01

    Corneal infiltrative events (CIEs) are being reported with increasing frequency in lens wearers and may be related to specific multipurpose disinfecting solution (MPDS), contact lens type or bacterial bio-burden. Here, the efficacy of MPDS's against bacteria from contact lens storage cases (CLSC) of patients with CIEs was investigated. Eighteen CLSC from patients with CIEs were cultured. All reported using the same MPDS based on PQ-1+Aldox+nonanoyl-EDTA prior to experiencing CIEs. Bacteria were identified and tested for sensitivity to MPDS-1 and three other MPSDs. 16/18 CLSC (89%) contained bacterial counts of ≥10(4)-10(8)/mL. Achromobacter spp. was most frequently identified and was found in 11/18 cases (61%). This was followed by 4/18 (22%) Stenotrophomonas maltophilia, 3/18 (17%) Serratia marcescens, 3/18 (17%) Delftia spp., 2/18 (11%) Elizabethkingia spp., 2/18 (11%) Chryseobacterium indologenes and 1/18 Sphingobacterium spiritivorum. Acanthamoeba was not isolated. All of the Achromobacter strains were resistant to MPDS-1 with <1log10 kill up to 14 days exposure and the solution also showed reduced efficacy against the other isolates at the manufacturer's recommended disinfection time of 6h. Two strains of S. maltophilia and Delftia spp. grew in the solution over 14 days. Factors responsible for causing adverse events such as CIEs in contact lens wearers remain unclear. However, the presence of significant bio-burden in the contact lens storage case and lens may initiate an immunological response resulting in CIEs either directly or through the release of endotoxins (e.g. lipopolysaccharides) from the bacterial outer cell membrane.

  5. Identification and susceptibility to multipurpose disinfectant solutions of bacteria isolated from contact lens storage cases of patients with corneal infiltrative events.

    PubMed

    Kilvington, Simon; Shovlin, Joseph; Nikolic, Marina

    2013-12-01

    Corneal infiltrative events (CIEs) are being reported with increasing frequency in lens wearers and may be related to specific multipurpose disinfecting solution (MPDS), contact lens type or bacterial bio-burden. Here, the efficacy of MPDS's against bacteria from contact lens storage cases (CLSC) of patients with CIEs was investigated. Eighteen CLSC from patients with CIEs were cultured. All reported using the same MPDS based on PQ-1+Aldox+nonanoyl-EDTA prior to experiencing CIEs. Bacteria were identified and tested for sensitivity to MPDS-1 and three other MPSDs. 16/18 CLSC (89%) contained bacterial counts of ≥10(4)-10(8)/mL. Achromobacter spp. was most frequently identified and was found in 11/18 cases (61%). This was followed by 4/18 (22%) Stenotrophomonas maltophilia, 3/18 (17%) Serratia marcescens, 3/18 (17%) Delftia spp., 2/18 (11%) Elizabethkingia spp., 2/18 (11%) Chryseobacterium indologenes and 1/18 Sphingobacterium spiritivorum. Acanthamoeba was not isolated. All of the Achromobacter strains were resistant to MPDS-1 with <1log10 kill up to 14 days exposure and the solution also showed reduced efficacy against the other isolates at the manufacturer's recommended disinfection time of 6h. Two strains of S. maltophilia and Delftia spp. grew in the solution over 14 days. Factors responsible for causing adverse events such as CIEs in contact lens wearers remain unclear. However, the presence of significant bio-burden in the contact lens storage case and lens may initiate an immunological response resulting in CIEs either directly or through the release of endotoxins (e.g. lipopolysaccharides) from the bacterial outer cell membrane. PMID:23466175

  6. 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

  7. Severe Bloodstream Infection due to KPC-Producer E coli in a Renal Transplant Recipient Treated With the Double-Carbapenem Regimen and Analysis of In Vitro Synergy Testing: A Case Report.

    PubMed

    Oliva, Alessandra; Cipolla, Alessia; Gizzi, Francesca; D'Abramo, Alessandra; Favaro, Marco; De Angelis, Massimiliano; Ferretti, Giancarlo; Russo, Gianluca; Iannetta, Marco; Mastroianni, Claudio M; Mascellino, Maria T; Vullo, Vincenzo

    2016-02-01

    Transplant recipients are at high risk of infections caused by multidrug resistant microorganisms. Due to the limited therapeutic options, innovative antimicrobial combinations against carbapenem-resistant Enterobacteriaceae causing severe infections are necessary.A 61-year-old woman with a history of congenital solitary kidney underwent renal transplantation. The postoperative course was complicated by nosocomial pneumonia due to Stenotrophomonas maltophilia and pan-sensitive Escherichia coli, successfully treated with antimicrobial therapy. On postoperative day 22, diagnosis of surgical site infection and nosocomial pneumonia with concomitant bacteremia due to a Klebisella pneumoniae carbapenemase-producer E coli was made. The patient was treated with the double-carbapenem regimen (high dose of meropenem plus ertapenem) and a potent synergistic and bactericidal activity of this un-conventional therapeutic strategy was observed in vitro. Despite a microbiological response with prompt negativity of blood cultures, the patient faced a worse outcome because of severe hemorrhagic shock.The double-carbapenem regimen might be considered as a rescue therapy in those subjects, including transplant recipients, in whom previous antimicrobial combinations failed or when colistin use might be discouraged. Performing in vitro synergy testing should be strongly encouraged in cases of infections caused by pan-drug resistant strains, especially in high-risk patients. PMID:26886594

  8. Decontamination effects of low-temperature plasma generated by corona discharge. Part II: new insights.

    PubMed

    Scholtz, V; Julák, J; Kríha, V; Mosinger, J; Kopecká, S

    2007-01-01

    The second part of our paper presents the results of experiments with the decontamination of surfaces by low-temperature plasma generated by corona discharge in air at atmospheric pressure. A simple device is described and the effects of the corona discharge on model microorganisms, viz. the yeast Candida albicans, Gram-negative bacteria Escherichia coli, Enterobacter aerogenes, Neisseria sicca, Stenotrophomonas maltophilia, Gram-positive bacteria Deinococcus radiodurans, Enterococcus faecium, Staphylococcus epidermidis, Streptococcus sanguinis, and vegetative and spore forms of Geobacillus stearothermophilus are discussed. A similar microbicidal effect after about one-minute exposure was observed in all vegetative forms of the microorganisms. Measurement in growth inhibition zones on a semisolid medium was used to determine the dependence of the microbicidal effect on exposure time and the distance between electrodes. Counting of colonies served to assess the microbicidal effect of the discharge on contaminated inert surfaces observable after more than 1 min exposure. Geobacillus stearothermophilus spores were found to have several times lower susceptibility to the action of the discharge and the microbicidal effect was observed only after an 8 min exposure. Reaction with the iodide reagent did not unambiguously demonstrate the difference between ozone and singlet oxygen as presumed active components of the corona. The area distribution of reactive oxygen species was determined; it was found to differ from the Wartburg law depending on exposure time. Qualitative evidence was obtained on the penetration of the reactive oxygen species into the semisolid medium. PMID:18225640

  9. The exposition of a calcareous Mediterranean soil to toxic concentrations of Cr, Cd and Pb produces changes in the microbiota mainly related to differential metal bioavailability.

    PubMed

    Caliz, Joan; Montserrat, Genoveva; Martí, Esther; Sierra, Jordi; Cruañas, Robert; Garau, M Antonia; Triadó-Margarit, Xavier; Vila, Xavier

    2012-10-01

    The involvement of the bacterial community of an agricultural Mediterranean calcareous soil in relation to several heavy metals has been studied in microcosms under controlled laboratory conditions. Soil samples were artificially polluted with Cr(VI), Cd(II) and Pb(II) at concentrations ranging from 0.1 to 5000 mg kg(-1) and incubated along 28 d. The lowest concentrations with significant effects in soil respirometry were 10 mg kg(-1) Cr and 1000 mg kg(-1) Cd and Pb. However, only treatments showing more than 40% inhibition of respirometric activity led to significant changes in bacterial composition, as indicated by PCR-DGGE analyses. Presumable Cr- and Cd-resistant bacteria were detected in polluted microcosms, but development of the microbiota was severely impaired at the highest amendments of both metals. Results also showed that bioavailability is an important factor determining the impact of the heavy metals assayed, and even an inverted potential toxicity ranking could be achieved if their soluble fraction is considered instead of the total concentration. Moreover, multiresistant bacteria were isolated from Cr-polluted soil microcosms, some of them showing the capacity to reduce Cr(VI) concentrations between 26% and 84% of the initial value. Potentially useful strains for bioremediation were related to Arthrobacter crystallopoietes, Stenotrophomonas maltophilia and several species of Bacillus.

  10. 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

  11. 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

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

    PubMed

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

    2012-12-01

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

  13. In vitro and in vivo evaluation of BMAP-derived peptides for the treatment of cystic fibrosis-related pulmonary infections.

    PubMed

    Mardirossian, Mario; Pompilio, Arianna; Crocetta, Valentina; De Nicola, Serena; Guida, Filomena; Degasperi, Margherita; Gennaro, Renato; Di Bonaventura, Giovanni; Scocchi, Marco

    2016-09-01

    Patients with cystic fibrosis require pharmacological treatment against chronic lung infections. The alpha-helical antimicrobial peptides BMAP-27 and BMAP-28 have shown to be highly active in vitro against planktonic and sessile forms of multidrug-resistant Pseudomonas aeruginosa, Staphylococcus aureus, and Stenotrophomonas maltophilia cystic fibrosis strains. To develop small antibacterial peptides for therapeutic use, we tested shortened/modified BMAP fragments, and selected the one with the highest in vitro antibacterial activity and lowest in vivo acute pulmonary toxicity. All the new peptides have shown to roughly maintain their antibacterial activity in vitro. The 1-18 N-terminal fragment of BMAP-27, showing MIC90 of 16 µg/ml against P. aeruginosa isolates and strain-dependent anti-biofilm effects, showed the lowest pulmonary toxicity in mice. However, when tested in a murine model of acute lung infection by P. aeruginosa, BMAP-27(1-18) did not show any curative effect. If exposed to murine broncho-alveolar lavage fluid BMAP-27(1-18) was degraded within 10 min, suggesting it is not stable in pulmonary environment, probably due to murine proteases. Our results indicate that shortened BMAP peptides could represent a starting point for antibacterial drugs, but they also indicate that they need a further optimization for effective in vivo use. PMID:27270571

  14. [The microbiology laboratory's contribution to the surveillance and control of outbreaks caused by nonfermentative Gram-negative bacilli].

    PubMed

    Fernández-Cuenca, Felipe; López-Cortés, Luis E; Rodríguez-Baño, Jesús

    2011-03-01

    Pseudomonas aeruginosa, Acinetobacter baumannii and Stenotrophomonas maltophilia are, among others, the most important nonfermentative Gram-negative bacilli within hospitals. These organisms are able to cause different types of nosocomial infections in predisposed patients, and P. aeruginosa and A. baumannii in particular may cause extensive clonal outbreaks and complex situations in which sporadic isolates may coexist with some epidemic strains. Some common features are their intrinsic resistance to many antimicrobials, their capacity to further develop antimicrobial resistance, and the possibility of environmental reservoirs as sources of these microorganisms in healthcare centers. The microbiology laboratory plays a key role in the detection of potential outbreaks, in the identification of new resistance mechanisms and in the characterization of local epidemiology, by detecting colonized patients and/or environmental reservoirs if needed, appropriately identifying the isolates, phenotypically or genotypically characterizing their mechanisms of resistance, if appropriate, and finally by using different molecular techniques for clonal typing, which are reviewed in this article. Such activities must be performed in the context of the surveillance and control programs of specific institutions and as part of the daily work of multidisciplinary infection control teams.

  15. Carbapenemases: a problem in waiting?

    PubMed

    Livermore, D M; Woodford, N

    2000-10-01

    Carbapenems are stable to most prevalent beta-lactamases, and chromosomal carbapenemases are restricted to Stenotrophomonas maltophilia, to a few Bacteroides fragilis, and to rare pathogens. Nevertheless, an acquired metallo-beta-lactamase called IMP-1 is beginning to emerge in Pseudomonas aeruginosa and Enterobacteriaceae isolates in Japan, and has also been found in isolates from Singapore. Furthermore, IMP-producing Acinetobacter spp. have been identified in Italy and Hong Kong. Recently a second group of acquired metallo-carbapenemases, the VIM types, has been recorded from P. aeruginosa isolates in five Eurasian countries. Weak carbapenemases belonging to molecular class D are emerging in A. baumannii world-wide, with two sub-groups apparent. A few acquired carbapenemases belonging to molecular class A also have been reported. Finally it has also been shown that enzymes with feeble carbapenemase activity (e.g. AmpC types and some SHV enzymes) may confer resistance in exceptionally impermeable strains; counterwise, even potent carbapenemases, such as IMP-1, may only give a small reduction in susceptibility in Enterobacteriaceae that lack permeability lesions. Is the emergence of carbapenemase a problem waiting to happen?

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

    PubMed

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

    2005-11-01

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

  17. Biodegradation of phenanthrene in bioaugmented microcosm by consortium ASP developed from coastal sediment of Alang-Sosiya ship breaking yard.

    PubMed

    Patel, Vilas; Patel, Janki; Madamwar, Datta

    2013-09-15

    A phenanthrene-degrading bacterial consortium (ASP) was developed using sediment from the Alang-Sosiya shipbreaking yard at Gujarat, India. 16S rRNA gene-based molecular analyses revealed that the bacterial consortium consisted of six bacterial strains: Bacillus sp. ASP1, Pseudomonas sp. ASP2, Stenotrophomonas maltophilia strain ASP3, Staphylococcus sp. ASP4, Geobacillus sp. ASP5 and Alcaligenes sp. ASP6. The consortium was able to degrade 300 ppm of phenanthrene and 1000 ppm of naphthalene within 120 h and 48 h, respectively. Tween 80 showed a positive effect on phenanthrene degradation. The consortium was able to consume maximum phenanthrene at the rate of 46 mg/h/l and degrade phenanthrene in the presence of other petroleum hydrocarbons. A microcosm study was conducted to test the consortium's bioremediation potential. Phenanthrene degradation increased from 61% to 94% in sediment bioaugmented with the consortium. Simultaneously, bacterial counts and dehydrogenase activities also increased in the bioaugmented sediment. These results suggest that microbial consortium bioaugmentation may be a promising technology for bioremediation.

  18. Severe Bloodstream Infection due to KPC-Producer E coli in a Renal Transplant Recipient Treated With the Double-Carbapenem Regimen and Analysis of In Vitro Synergy Testing

    PubMed Central

    Oliva, Alessandra; Cipolla, Alessia; Gizzi, Francesca; D’Abramo, Alessandra; Favaro, Marco; De Angelis, Massimiliano; Ferretti, Giancarlo; Russo, Gianluca; Iannetta, Marco; Mastroianni, Claudio M.; Mascellino, Maria T.; Vullo, Vincenzo

    2016-01-01

    Abstract Transplant recipients are at high risk of infections caused by multidrug resistant microorganisms. Due to the limited therapeutic options, innovative antimicrobial combinations against carbapenem-resistant Enterobacteriaceae causing severe infections are necessary. A 61-year-old woman with a history of congenital solitary kidney underwent renal transplantation. The postoperative course was complicated by nosocomial pneumonia due to Stenotrophomonas maltophilia and pan-sensitive Escherichia coli, successfully treated with antimicrobial therapy. On postoperative day 22, diagnosis of surgical site infection and nosocomial pneumonia with concomitant bacteremia due to a Klebisella pneumoniae carbapenemase-producer E coli was made. The patient was treated with the double-carbapenem regimen (high dose of meropenem plus ertapenem) and a potent synergistic and bactericidal activity of this un-conventional therapeutic strategy was observed in vitro. Despite a microbiological response with prompt negativity of blood cultures, the patient faced a worse outcome because of severe hemorrhagic shock. The double-carbapenem regimen might be considered as a rescue therapy in those subjects, including transplant recipients, in whom previous antimicrobial combinations failed or when colistin use might be discouraged. Performing in vitro synergy testing should be strongly encouraged in cases of infections caused by pan-drug resistant strains, especially in high-risk patients. PMID:26886594

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

    PubMed

    Guan, X; He, L; Hu, B; Hu, J; Huang, X; Lai, G; Li, Y; Liu, Y; Ni, Y; Qiu, H; Shao, Z; Shi, Y; Wang, M; Wang, R; Wu, D; Xie, C; Xu, Y; Yang, F; Yu, K; Yu, Y; Zhang, J; Zhuo, C

    2016-03-01

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

  20. [Biodiversity of mesophilic microbial community BYND-8 capability of lignocellulose degradation and its effect on biogas production].

    PubMed

    Wang, Wei-Dong; Song, Ya-Bin; Wang, Yan-Jie; Gao, Ya-Mei; Jing, Rui-Yong; Cui, Zong-Jun

    2011-01-01

    The biodiversity of a mesophilic microbial community BYND-8 capable of degrading lignocellulose at 30 degrees C was detected using denaturing gradient gel electrophoresis (DGGE) and the isolation of pure cultures, and the effect of the liquid of rice straw degradation by BYND-8 on biogas production was measured. Six bacterial strains were isolated using peptone cellulose solution medium, and the highest similarities of their 16S rDNA gene sequences to Serratia sp. PSGB 13, S. marcescens strain UFLA-25LS, S. marcescens strain DAP33, Alcaligenes sp. YcX-20, Stenotrophomonas maltophilia strain C6, Bacillus cereus isolate BRL02-71 were 99%, 100%, 96%, 100%, 100% and 99%, respectively. In addition, one band was detected besides six bands of cultured isolates on the DGGE gel, and it showed 100% sequence similarity to uncultured bacterium clone ATB-KS-1446. The cumulative biogas and methane productions of biogas fermentation system added with the liquid of rice straw degraded by BYND-8 were 13 167 mL and 7 248 mL, 44.5% and 95.3% higher than those of the control, respectively, in the early 15 days of fermentation. The results showed that the biodiversity of microbial community BYND-8 was very high, and the time of producing biogas was put forward and biogas production was increased with application of microbial community for rice straw pretreatment during the biogas fermentation.

  1. 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.

  2. Assessment of chitin decomposer diversity within an upland grassland.

    PubMed

    Krsek, M; Wellington, E M

    2001-09-01

    The breakdown of chitin within an acidic upland grassland was studied. The aim was to provide a molecular characterisation of microorganisms involved in chitin degradation in the soil using soil microcosms and buried litter bags containing chitin. The investigation involved an examination of the effects of liming on the microbial communities within the soil and their chitinolytic activity. Microcosm experiments were designed to study the influence of lime and chitin enrichment on the grassland soil bacterial community ex situ under controlled environmental conditions. Bacterial and actinomycete counts were determined and total community DNA was extracted from the microcosms and from chitin bags buried at the experimental site. PCR based on specific 16S rRNA target sequences provided products for DGGE analysis to determine the structure of bacterial and actinomycete communities. Chitinase activity was assessed spectrophotometrically using chitin labelled with remazol brilliant violet. Both liming and chitin amendment increased bacterial and actinomycete viable counts and the chitinase activity. DGGE band patterns confirmed changes in bacterial populations under the influence of both treatments. PCR products amplified from DNA isolated from chitin bags were cloned and sequenced. Only a few matched known species but a prominent coloniser of chitin proved to be Stenotrophomonas maltophilia.

  3. 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.

  4. Genome survey and characterization of endophytic bacteria exhibiting a beneficial effect on growth and development of poplar trees.

    PubMed

    Taghavi, Safiyh; Garafola, Craig; Monchy, Sébastien; Newman, Lee; Hoffman, Adam; Weyens, Nele; Barac, Tanja; Vangronsveld, Jaco; van der Lelie, Daniel

    2009-02-01

    The association of endophytic bacteria with their plant hosts has a beneficial effect for many different plant species. Our goal is to identify endophytic bacteria that improve the biomass production and the carbon sequestration potential of poplar trees (Populus spp.) when grown in marginal soil and to gain an insight in the mechanisms underlying plant growth promotion. Members of the Gammaproteobacteria dominated a collection of 78 bacterial endophytes isolated from poplar and willow trees. As representatives for the dominant genera of endophytic gammaproteobacteria, we selected Enterobacter sp. strain 638, Stenotrophomonas maltophilia R551-3, Pseudomonas putida W619, and Serratia proteamaculans 568 for genome sequencing and analysis of their plant growth-promoting effects, including root development. Derivatives of these endophytes, labeled with gfp, were also used to study the colonization of their poplar hosts. In greenhouse studies, poplar cuttings (Populus deltoides x Populus nigra DN-34) inoculated with Enterobacter sp. strain 638 repeatedly showed the highest increase in biomass production compared to cuttings of noninoculated control plants. Sequence data combined with the analysis of their metabolic properties resulted in the identification of many putative mechanisms, including carbon source utilization, that help these endophytes to thrive within a plant environment and to potentially affect the growth and development of their plant hosts. Understanding the interactions between endophytic bacteria and their host plants should ultimately result in the design of strategies for improved poplar biomass production on marginal soils as a feedstock for biofuels.

  5. Frequency of fungi in respiratory samples from Turkish cystic fibrosis patients.

    PubMed

    Güngör, Ozge; Tamay, Zeynep; Güler, Nermin; Erturan, Zayre

    2013-03-01

    An increased isolation of fungi from the respiratory tract of patients with cystic fibrosis (CF) has been reported. The prevalence of different fungi in CF patients from Turkey is not known. Our aim was to determine the frequency of fungi in the respiratory tract of Turkish CF patients. We investigated a total of 184 samples from 48 patients. Samples were inoculated on Medium B+ and CHROMagar Candida. Candida albicans was the predominant yeast isolated [30 patients (62.5%)], followed by C. parapsilosis [6 (12.5%)] and C. dubliniensis 5 (10.4%). Aspergillus fumigatus was the most common filamentous fungus [5 (10.4%)] and non-fumigatus Aspergillus species were isolated from four (8.3%) patients. Staphylococcus aureus was the most frequently detected bacterium in C. albicans positive samples (53.57%). A. fumigatus and Pseudomonas aeruginosa or S. aureus were detected together in 75% of A. fumigatus positive samples each. No statistically significant relationship was detected between growth of yeast and moulds and age, gender, the use of inhaled corticosteroids or tobramycin. No significant correlation was found between the isolation of C. albicans, A. fumigatus and P. aeruginosa, Stenotrophomonas maltophilia or S. aureus, and the isolation of C. albicans and Haemophilus influenzae. Other factors which may be responsible for the increased isolation of fungi in CF need to be investigated.

  6. Isolation of Vermamoeba vermiformis and associated bacteria in hospital water.

    PubMed

    Pagnier, Isabelle; Valles, Camille; Raoult, Didier; La Scola, Bernard

    2015-03-01

    To detect new potential pathogens in hospital water, we isolated free-living amoebae in water samples taken from three different hospitals in Marseille (France). The samples were inoculated in media containing saline buffer and various bacteria as nutrient sources. The isolated amoebae were identified by gene sequencing. Among the 105 water samples, taken from 19 sites, we isolated 14 amoebae, of which 9 Vermamoeba vermiformis and 5 Acanthamoeba sp. None of the amoebae showed the presence of obligate bacterial endosymbionts. Because V. vermiformis was most commonly isolated, we used an axenic collection strain to isolate amoeba-resistant bacteria from the same sites. The isolated bacterial species included Stenotrophomonas maltophilia and Legionella sp. Legionella taurinensis was isolated for the first time in association with amoebae. A strict intracellular bacterium was isolated, that may represent a new genus among the Chlamydiales. We propose that it be named "Candidatus Rubidus massiliensis". Our study shows that the isolation and identification of new pathogens associated with amoebae, which were previously performed using Acanthamoeba sp., should instead use V. vermiformis because this organism is more commonly associated with humans and is an essential complement of Acanthamoeba sp. co-culture to study the ecology of hospital water supplies. PMID:25697664

  7. Production of N-acyl homoserine lactones by gram-negative bacteria isolated from contact lens wearers.

    PubMed

    Zhu, H; Thuruthyil, S J; Willcox, M D

    2001-06-01

    The purpose of this study was to investigate the production of N-acyl-homoserine lactone (AHL) signal molecules in ocular gram-negative bacteria. A total of 91 ocular strains isolated from contact lens adverse response patients and asymptomatic subjects were used in the study. These included Acinetobacter, Aeromonas hydrophila, Escherichia coli, Haemophilus influenzae, Klebsiella oxytoca, Pseudomonas aeruginosa, Serratia liquefaciens, Serratia marcescens, and Stenotrophomonas maltophilia. The biosensor strains Chromobacterium violaceum mutant CV026 and Agrobacterium tumefaciens A136 were used for detection of AHL signal molecules. The majority of A. hydrophila, P. aeruginosa, and S. liquefaciens strains produced more than one AHL molecule. Serratia marcescens strains were AHL positive only under detection of A136. The rest of the test species did not show any AHL production under the current detection system. These findings indicate that AHL-mediated quorum-sensing systems are present in some of the ocular bacteria, and the different signal molecules may be involved with the quorum-sensing pathway in the other bacterial species.

  8. 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

  9. Inoculation of paperboard mill sludge versus mixed culture bacteria for hydrogen production from paperboard mill wastewater.

    PubMed

    Farghaly, Ahmed; Tawfik, Ahmed; Danial, Amal

    2016-02-01

    A comparative evaluation of paperboard mill sludge (PMS) versus mixed culture bacteria (MCB) as inoculum for hydrogen production from paperboard mill wastewater (PMW) was investigated. The experiments were conducted at different initial cultivation pHs, inoculums to substrate ratios (ISRs gVS/gCOD), and hydraulic retention times (HRTs). The peak hydrogen yield (HY) of 5.29 ± 0.16 and 1.22 ± 0.11 mmol/gCODinitial was occurred at pH = 5 for MCB and PMS, respectively. At pH of 5, the HY and COD removal achieved the highest values of 2.26 ± 0.14 mmol/gCODinitial and 86 ± 1.6% at ISR = 6 for MCB, and 2.38 ± 0.25 mmol/gCODinitial and 60.4 ± 2.5% at ISRs = 3 for PMS. The maximum hydrogen production rate was 93.75 ± 8.9 mmol/day at HRT = 9.6 h from continuous upflow anaerobic reactor inoculated with MCB. Meanwhile, the 16S ribosomal RNA (rRNA) gene fragments indicated a dominance of a novel hydrogen-producing bacterium of Stenotrophomonas maltophilia for PMS microbial community. On the other hand, Escherichia fergusonii and Enterobacter hormaechei were the predominant species for MCB.

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

    PubMed Central

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

    2013-01-01

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

  11. Antibiotic resistance and extended-spectrum β-lactamases in isolated bacteria from seawater of Algiers beaches (Algeria).

    PubMed

    Alouache, Souhila; Kada, Mohamed; Messai, Yamina; Estepa, Vanesa; Torres, Carmen; Bakour, Rabah

    2012-01-01

    The aim of the study was to evaluate bacterial antibiotic resistance in seawater from four beaches in Algiers. The most significant resistance rates were observed for amoxicillin and ticarcillin, whereas they were relatively low for ceftazidime, cefotaxime and imipenem. According to sampling sites, the highest resistance rates were recorded for 2 sites subjected to chemical and microbiological inputs (amoxicillin, 43% and 52%; ticarcillin, 19.6% and 47.7%), and for 2 sites relatively preserved from anthropogenic influence, resistance rates were lowest (amoxicillin, 1.5% and 16%; ticarcillin, 0.8% and 2.6%). Thirty-four bacteria resistant to imipenem (n=14) or cefotaxime (n=20) were identified as Pseudomonas aeruginosa (n=15), Pseudomonas fluorescens (7), Stenotrophomonas maltophilia (4), Burkholderia cepacia (2), Bordetella sp. (1), Pantoea sp. (1), Acinetobacter baumannii (1), Chryseomonas luteola (1), Ochrobactrum anthropi (1) and Escherichia coli (1). Screening for extended spectrum β-lactamase showed the presence of CTX-M-15 β-lactamase in the E. coli isolate, and the encoding gene was transferable in association with the IncI1 plasmid of about 50 kbp. Insertion sequence ISEcp1B was located upstream of the CTX-M-15 gene. This work showed a significant level of resistance to antibiotics, mainly among environmental saprophytic bacteria. Transmissible CTX-M-15 was detected in E. coli; this may mean that contamination of the environment by resistant bacteria may cause the spread of resistance genes. PMID:22095134

  12. Characterization of copper-resistant rhizosphere bacteria from Avena sativa and Plantago lanceolata for copper bioreduction and biosorption.

    PubMed

    Andreazza, Robson; Okeke, Benedict C; Pieniz, Simone; Camargo, Flávio A O

    2012-04-01

    Copper is a toxic heavy metal widely used to microbial control especially in agriculture. Consequently, high concentrations of copper residues remain in soils selecting copper-resistant organisms. In vineyards, copper is routinely used for fungi control. This work was undertaken to study copper resistance by rhizosphere microorganisms from two plants (Avena sativa L. and Plantago lanceolata L.) common in vineyard soils. Eleven rhizosphere microorganisms were isolated, and four displayed high resistance to copper. The isolates were identified by 16S rRNA gene sequence analysis as Pseudomonas putida (A1), Stenotrophomonas maltophilia (A2) and Acinetobacter sp. (A6), isolated from Avena sativa rhizosphere, and Acinetobacter sp. (T5), isolated from Plantago lanceolata rhizosphere. The isolates displayed high copper resistance in the temperature range from 25°C to 35°C and pH in the range from 5.0 to 9.0. Pseudomonas putida A1 resisted as much as 1,000 mg L(-1) of copper. The isolates showed similar behavior on copper removal from liquid medium, with a bioremoval rate of 30% at 500 mg L(-1) after 24 h of growth. Speciation of copper revealed high copper biotransformation, reducing Cu(II) to Cu(I), capacity. Results indicate that our isolates are potential agents for copper bioremoval and bacterial stimulation of copper biosorption by Avena sativa and Plantago lanceolata. PMID:22002857

  13. Improved catalytic efficiency, thermophilicity, anti-salt and detergent tolerance of keratinase KerSMD by partially truncation of PPC domain

    PubMed Central

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

    2016-01-01

    The keratinase from Stenotrophomonas maltophilia (KerSMD) is known for its high activity and pH stability in keratin degradation. However, catalytic efficiency and detergent tolerability need to be improved in order to be used for industrial application. In this work, we obtained several keratinase variants with enhanced catalytic efficiency, thermophilicity, and anti-salt and detergent tolerability by partially truncating the PPC domain of KerSMD. The variants all showed improved catalytic efficiency to synthetic substrate AAPF, with the V355 variant having the highest kcat /Km value of 143.6 s−1 mM−1. The truncation of keratinase had little effect on alkaline stability but obviously decreased collagenase activity, developing its potential application in leather treatment. The variants V380, V370, and V355 were thermophilic, with a 1.7-fold enhancement of keratinlytic activity at 60 °C when compared to the wild type. The entire truncation of PPC domain obtained the variant V355 with improved tolerance to alkalinity, salt, chaotropic agents, and detergents. The V355 variant showed more than a 40% improvement in activity under 15% (w/v) NaCl or 4% (w/v) SDS solution, showing excellent stability under harsh washing and unhairing conditions. Our work investigated how protein engineering affects the function of PPC domain of KerSMD. PMID:27298079

  14. Diversity and antimicrobial properties of lactic acid bacteria isolated from rhizosphere of olive trees and desert truffles of Tunisia.

    PubMed

    Fhoula, Imene; 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.

  15. Nile Red Detection of Bacterial Hydrocarbons and Ketones in a High-Throughput Format

    PubMed Central

    Pinzon, Neissa M.; Aukema, Kelly G.; Gralnick, Jeffrey A.; Wackett, Lawrence P.

    2011-01-01

    ABSTRACT 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. PMID:21712420

  16. Investigation of bacterial pathogens on 70 frequently used environmental surfaces in a large urban U.S. university.

    PubMed

    Brooke, Joanna S; Annand, John W; Hammer, Angela; Dembkowski, Karen; Shulman, Stanford T

    2009-01-01

    After reports of increased severity of bacterial infections from community institutions, a broad spectrum of 70 surfaces was sampled for potential bacterial pathogens in the morning and afternoon of one day per week over three consecutive weeks in a large U.S. university. Surfaces included public telephone mouthpieces, water fountain drains, student computer keyboards and desks, and buttons on elevators, vending machines, and photocopiers. A total of 420 samples was obtained. Bacterial counts were high on telephone mouthpieces, up to 168.8 colony-forming units (CFUs).cm(-2) of surface area. Stenotrophomonas maltophilia was isolated from 60% of fountain drains. Ninety percent of the keyboards showed positive bacterial cultures in the afternoon sampling. Staphylococcus aureus was identified on keyboards, telephone mouthpieces, and an elevator button. No S. aureus were methicillin-resistant. The swab sampling method reduced bacterial counts to less than or equal to 2.0 CFU.cm(-2) on keyboards and telephone mouthpieces. Disinfectants for possible use in cleaning of telephones, water fountain drains, and keyboards are discussed.

  17. Physicochemical and Antibacterial Properties of Chitosan Extracted from Waste Shrimp Shells.

    PubMed

    Vilar Junior, José Carlos; Ribeaux, Daylin Rubio; Alves da Silva, Carlos Alberto; De Campos-Takaki, Galba Maria

    2016-01-01

    This research aims to study the production of chitosan from shrimp shell (Litopenaeus vannamei) of waste origin using two chemical methodologies involving demineralization, deproteinization, and the degree of deacetylation. The evaluation of the quality of chitosan from waste shrimp shells includes parameters for the yield, physical chemistry characteristics by infrared spectroscopy (FT-IR), the degree of deacetylation, and antibacterial activity. The results showed (by Method 1) extraction yields for chitin of 33% and for chitosan of 49% and a 76% degree of deacetylation. Chitosan obtained by Method 2 was more efficient: chitin (36%) and chitosan (63%), with a high degree of deacetylation (81.7%). The antibacterial activity was tested against Gram-negative bacteria (Stenotrophomonas maltophilia and Enterobacter cloacae) and Gram-positive Bacillus subtilis and the Minimum Inhibitory Concentrations (MIC) and the Minimum Bactericidal Concentration (MBC) were determined. Method 2 showed that extracted chitosan has good antimicrobial potential against Gram-positive and Gram-negative bacteria and that the process is viable. PMID:27478443

  18. Application of a continuously stirred tank bioreactor (CSTR) for bioremediation of hydrocarbon-rich industrial wastewater effluents.

    PubMed

    Gargouri, Boutheina; Karray, Fatma; Mhiri, Najla; Aloui, Fathi; Sayadi, Sami

    2011-05-15

    A continuously stirred tank bioreactor (CSTR) was used to optimize feasible and reliable bioprocess system in order to treat hydrocarbon-rich industrial wastewaters. A successful bioremediation was developed by an efficient acclimatized microbial consortium. After an experimental period of 225 days, the process was shown to be highly efficient in decontaminating the wastewater. The performance of the bioaugmented reactor was demonstrated by the reduction of COD rates up to 95%. The residual total petroleum hydrocarbon (TPH) decreased from 320 mg TPH l(-1) to 8 mg TPH l(-1). Analysis using gas chromatography-mass spectrometry (GC-MS) identified 26 hydrocarbons. The use of the mixed cultures demonstrated high degradation performance for hydrocarbons range n-alkanes (C10-C35). Six microbial isolates from the CSTR were characterized and species identification was confirmed by sequencing the 16S rRNA genes. The partial 16S rRNA gene sequences demonstrated that 5 strains were closely related to Aeromonas punctata (Aeromonas caviae), Bacillus cereus, Ochrobactrum intermedium, Stenotrophomonas maltophilia and Rhodococcus sp. The 6th isolate was affiliated to genera Achromobacter. Besides, the treated wastewater could be considered as non toxic according to the phytotoxicity test since the germination index of Lepidium sativum ranged between 57 and 95%. The treatment provided satisfactory results and presents a feasible technology for the treatment of hydrocarbon-rich wastewater from petrochemical industries and petroleum refineries.

  19. In Vitro Assessment of the Antimicrobial Efficacy of Optimized Nitroglycerin-Citrate-Ethanol as a Nonantibiotic, Antimicrobial Catheter Lock Solution for Prevention of Central Line-Associated Bloodstream Infections.

    PubMed

    Reitzel, Ruth A; Rosenblatt, Joel; Hirsh-Ginsberg, Cheryl; Murray, Kimberly; Chaftari, Anne-Marie; Hachem, Ray; Raad, Issam

    2016-09-01

    The rapid, broad-spectrum, biofilm-eradicating activity of the combination of 0.01% nitroglycerin, 7% citrate, and 20% ethanol and its potential as a nonantibiotic, antimicrobial catheter lock solution (ACLS) were previously reported. Here, a nitroglycerin-citrate-ethanol (NiCE) ACLS optimized for clinical assessment was developed by reducing the nitroglycerin and citrate concentrations and increasing the ethanol concentration. Biofilm-eradicating activity was sustained when the ethanol concentration was increased from 20 to 22% which fully compensated for reducing the citrate concentration from 7% to 4% as well as the nitroglycerin concentration from 0.01% to 0.0015% or 0.003%. The optimized formulations demonstrated complete and rapid (2 h) eradication of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-intermediate Staphylococcus aureus (VISA), methicillin-resistant Staphylococcus epidermidis (MRSE), vancomycin-resistant enterococci (VRE), multidrug-resistant (MDR) Pseudomonas aeruginosa, MDR Klebsiella pneumoniae, MDR Enterobacter cloacae, MDR Acinetobacter baumannii, MDR Escherichia coli, MDR Stenotrophomonas maltophilia, Candida albicans, and Candida glabrata biofilms. The optimized NiCE lock solutions demonstrated anticoagulant activities comparable to those of heparin lock solutions. NiCE lock solution was significantly more effective than taurolidine-citrate-heparin lock solution in eradicating biofilms of Staphylococcus aureus and Candida glabrata The optimized, nonantibiotic, heparin-free NiCE lock solution demonstrates rapid broad-spectrum biofilm eradication as well as effective anticoagulant activity, making NiCE a high-quality ACLS candidate for clinical assessment.

  20. Bacterial degradation of naproxen--undisclosed pollutant in the environment.

    PubMed

    Wojcieszyńska, Danuta; Domaradzka, Dorota; Hupert-Kocurek, Katarzyna; Guzik, Urszula

    2014-12-01

    The presence of non-steroidal anti-inflammatory drugs (NSAIDs) in the environment is an emerging problem due to their potential influence on human health and biocenosis. This is the first report on the biotransformation of naproxen, a polycyclic NSAID, by a bacterial strain. Stenotrophomonas maltophilia KB2 transformed naproxen within 35 days with about 28% degradation efficiency. Under cometabolic conditions with glucose or phenol as a carbon source degradation efficiency was 78% and 40%, respectively. Moreover, in the presence of naproxen phenol monooxygenase, naphthalene dioxygenase, hydroxyquinol 1,2-dioxygenase and gentisate 1,2-dioxygenase were induced. This suggests that degradation of naproxen occurs by its hydroxylation to 5,7,8-trihydroxynaproxen, an intermediate that can be cleaved by hydroxyquinol 1,2-dioxygenase. The cleavage product is probably further oxidatively cleaved by gentisate 1,2-dioxygenase. The obtained results provide the basis for the use of cometabolic systems in the bioremediation of polycyclic NSAID-contaminated environments. PMID:25026371

  1. Improved catalytic efficiency, thermophilicity, anti-salt and detergent tolerance of keratinase KerSMD by partially truncation of PPC domain.

    PubMed

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

    2016-01-01

    The keratinase from Stenotrophomonas maltophilia (KerSMD) is known for its high activity and pH stability in keratin degradation. However, catalytic efficiency and detergent tolerability need to be improved in order to be used for industrial application. In this work, we obtained several keratinase variants with enhanced catalytic efficiency, thermophilicity, and anti-salt and detergent tolerability by partially truncating the PPC domain of KerSMD. The variants all showed improved catalytic efficiency to synthetic substrate AAPF, with the V355 variant having the highest kcat /Km value of 143.6 s(-1) mM(-1). The truncation of keratinase had little effect on alkaline stability but obviously decreased collagenase activity, developing its potential application in leather treatment. The variants V380, V370, and V355 were thermophilic, with a 1.7-fold enhancement of keratinlytic activity at 60 °C when compared to the wild type. The entire truncation of PPC domain obtained the variant V355 with improved tolerance to alkalinity, salt, chaotropic agents, and detergents. The V355 variant showed more than a 40% improvement in activity under 15% (w/v) NaCl or 4% (w/v) SDS solution, showing excellent stability under harsh washing and unhairing conditions. Our work investigated how protein engineering affects the function of PPC domain of KerSMD. PMID:27298079

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

    PubMed Central

    Conlon, J. Michael; Mechkarska, Milena

    2014-01-01

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

  3. Xenopus laevis oocytes infected with multi-drug–resistant bacteria: implications for electrical recordings

    PubMed Central

    O'Connell, Denice; Mruk, Karen; Rocheleau, Jessica M.

    2011-01-01

    The Xenopus laevis oocyte has been the workhorse for the investigation of ion transport proteins. These large cells have spawned a multitude of novel techniques that are unfathomable in mammalian cells, yet the fickleness of the oocyte has driven many researchers to use other membrane protein expression systems. Here, we show that some colonies of Xenopus laevis are infected with three multi-drug–resistant bacteria: Pseudomonas fluorescens, Pseudomonas putida, and Stenotrophomonas maltophilia. Oocytes extracted from infected frogs quickly (3–4 d) develop multiple black foci on the animal pole, similar to microinjection scars, which render the extracted eggs useless for electrical recordings. Although multi-drug resistant, the bacteria were susceptible to amikacin and ciprofloxacin in growth assays. Supplementing the oocyte storage media with these two antibiotics prevented the appearance of the black foci and afforded oocytes suitable for whole-cell recordings. Given that P. fluorescens associated with X. laevis has become rapidly drug resistant, it is imperative that researchers store the extracted oocytes in the antibiotic cocktail and not treat the animals harboring the multi-drug–resistant bacteria. PMID:21788613

  4. 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

  5. Physicochemical and Antibacterial Properties of Chitosan Extracted from Waste Shrimp Shells

    PubMed Central

    Vilar Junior, José Carlos; Ribeaux, Daylin Rubio; Alves da Silva, Carlos Alberto

    2016-01-01

    This research aims to study the production of chitosan from shrimp shell (Litopenaeus vannamei) of waste origin using two chemical methodologies involving demineralization, deproteinization, and the degree of deacetylation. The evaluation of the quality of chitosan from waste shrimp shells includes parameters for the yield, physical chemistry characteristics by infrared spectroscopy (FT-IR), the degree of deacetylation, and antibacterial activity. The results showed (by Method 1) extraction yields for chitin of 33% and for chitosan of 49% and a 76% degree of deacetylation. Chitosan obtained by Method 2 was more efficient: chitin (36%) and chitosan (63%), with a high degree of deacetylation (81.7%). The antibacterial activity was tested against Gram-negative bacteria (Stenotrophomonas maltophilia and Enterobacter cloacae) and Gram-positive Bacillus subtilis and the Minimum Inhibitory Concentrations (MIC) and the Minimum Bactericidal Concentration (MBC) were determined. Method 2 showed that extracted chitosan has good antimicrobial potential against Gram-positive and Gram-negative bacteria and that the process is viable. PMID:27478443

  6. Fatty acid hydration activity of a recombinant Escherichia coli-based biocatalyst is improved through targeting the oleate hydratase into the periplasm.

    PubMed

    Jung, Sang-Min; Seo, Joo-Hyun; Lee, Jung-Hoo; Park, Jin-Byung; Seo, Jin-Ho

    2015-12-01

    Whole-cell biotransformation of fatty acids can be influenced by the activities of catalytic enzymes and by the efficiency of substrate transport into host cells. Here, we improved fatty acid hydration activity of the recombinant Escherichia coli expressing an oleate hydratase of Stenotrophomonas maltophilia by targeting the catalytic enzyme into the periplasm instead of the cytoplasm. Recombinant E. coli producing OhyA in the periplasm under guidance of the PelB signal sequence (E. coli OhyA_PP) exhibited significantly greater hydration activity with oleic acid and linoleic acid compared to a recombinant E. coli producing OhyA in the cytoplasm (E. coli OhyA_CS). For example, the oleate double bond hydration rate of E. coli OhyA_PP was >400 μmol/g dry cells/min (400 U/g dry cells), which is >10-fold higher than that of E. coli OhyA_CS. As the specific activities of the enzymes targeted into the cytoplasm and periplasm were comparable, we assumed that targeting OhyA into the periplasm could accelerate fatty acid transport to the catalytic enzymes by skipping the major mass transport barrier of the cytoplasmic membrane. Our results will contribute to the development of whole-cell biocatalysts for fatty acid biotransformation.

  7. Potential of the adhesion of bacteria isolated from drinking water to materials.

    PubMed

    Simões, Lúcia Chaves; Simões, Manuel; Oliveira, Rosário; Vieira, Maria João

    2007-04-01

    Heterotrophic bacteria (11 genera, 14 species, 25 putative strains) were isolated from drinking water, identified either biochemically or by partial 16s rDNA gene sequencing and their adherence characteristics were determined by two methods: i. thermodynamic prediction of adhesion potential by measuring hydrophobicity (contact angle measurements) and ii. by measuring adherence to eight different substrata (ASI 304 and 316 stainless steel, copper, polyvinyl chloride, polypropylene, polyethylene, silicone and glass). All the test organisms were hydrophilic and inter-species variation in hydrophobicity occurred only for Comamonas acidovorans. Stainless steel 304 (SS 304), copper, polypropylene (PP), polyethylene (PE) and silicone thermodynamically favoured adhesion for the majority of test strains (>18/25), whilst adhesion was generally less thermodynamically favorable for stainless steel 316 (SS 316), polyvinyl chloride (PVC) and glass. The predictability of thermodynamic adhesion test methods was validated by comparison with 24-well microtiter plate assays using nine reference strains and three adhesion surfaces (SS 316, PVC and PE). Results for Acinetobacter calcoaceticus, Burkolderia cepacia and Stenotrophomonas maltophilia sp. 2 were congruent between both methods whilst they differed for the other bacteria to at least one material. Only A. calcoaceticus had strongly adherent properties to the three tested surfaces. Strain variation in adhesion ability was detected only for Sphingomonas capsulata. Analysis of adhesion demonstrated that in addition to physicochemical surface properties of bacterium and substratum, biological factors are involved in early adhesion processes, suggesting that reliance on thermodynamic approaches alone may not accurately predict adhesion capacity. PMID:17440920

  8. 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

  9. Comparative studies on toluene removal and pressure drop in biofilters using different packing materials.

    PubMed

    Ryu, Hee Wook; Kim, So Jung; Cho, Kyung Suk

    2010-05-01

    To select the best available packing material for malodorous organic gases such as toluene and benzene, biofilter performance was compared in biofilters employed different packing materials including porous ceramic (celite), Jeju scoria (lava), a mixture of granular activated carbon (GAC) and celite (GAC/celite), and cubic polyurethane foam (PU). A toluene-degrading bacterium, Stenotrophomonas maltophilia T3-c, was used as the inoculum. The maximum elimination capacities in the celite, lava, and GAC/celite biofilters were 100, 130, and 110 gm(-3) hr(-1), respectively. The elimination capacity for the PU biofilter was approximately 350 g m(-3) hr(-1) at an inlet loading of approximately 430 g m(-3) hr(-1), which was 2 to 3.5 times higher than for the other biofilters. The pressure drop gradually increased in the GAC/ celite, celite and lava biofilters after 23 day due to bacterial over-growth, and the toluene removal efficiency remarkably decreased with increasing pressure drop. Backwashing method was not effective for the control of biomass in these biofilters. In the PU biofilter however, backwashing allowed maintenance of a pressure drop of 1 to 3 mm H2O m(-1) and a removal efficiency of > 80%, indicating that the PU was the best packing material for toluene removal among the packing materials tested.

  10. In vitro activity and spectrum of LY333328, a novel glycopeptide derivative.

    PubMed

    Jones, R N; Barrett, M S; Erwin, M E

    1997-02-01

    Reference methods were used to determine the potency of LY333328, a semisynthetic glycopeptide derivative with a key N-alkylation substitution, against 833 strains (393 gram-positive strains and representative gram-negative bacilli) with various defined resistance mechanisms. The MICs at which 90% of the isolates are inhibited (MIC90S) (in micrograms per milliliter) of LY333328 and the percentages of strains at < or = 8 micrograms/ml were as follows: for oxacillin-susceptible Staphylococcus aureus, 2 and 100%, and for oxacillin-resistant Staphylococcus aureus, 4 and 100%; for oxacillin-susceptible Staphylococcus epidermis, 4 and 100%, and for oxacillin-resistant Staphylococcus aureus, 8 and 96%; for Streptococcus serogroups A, B, C, and G, 0.25 to 1 and 100%; for Streptococcus pneumoniae < or = 0.015 to 0.06 and 100%; for Enterococcus faecalis, 2 and 100%; and for vancomycin-susceptible Enterococcus faecium, 0.25 and 100%, and for vancomycin-resistant Enterococcus faecium, 4 and 100%. LY333328 was not active (MIC50, > or = 16 micrograms/ml) against more than 400 representative strains of Enterobacteriaceae, pseudomonads, Acinetobacter spp., Stenotrophomonas maltophilia, Haemophilus influenzae, Moraxella catarrhalis, pathogenic Neisseria spp., and anaerobic gram-negative bacilli. Gram-positive anaerobes were LY333328 susceptible (MICs, < or = 2 micrograms/ml). Test methods and conditions may have affected MICs of LY333328, with most (species variation) agar dilution MICs being greater than the broth microdilution MICs. PMID:9021216

  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. Changing trends in etiology of bacteremia in patients with cancer.

    PubMed

    Safdar, A; Rodriguez, G H; Balakrishnan, M; Tarrand, J J; Rolston, K V I

    2006-08-01

    The present study was conducted to determine trends in the quantitative bacterial load patterns of bacterial bloodstream infections (BSI) caused by various bacteria in patients receiving care at a comprehensive cancer center. Bacterial loads of all consecutive quantitative blood cultures performed during 1998 and 2004 were graded quantitatively. Gram-positive bacteria (GPB) were responsible for the majority of BSI episodes in both years studied: 740 of 1,055 (73%) in 1998 and 820 of 1,025 (82%) in 2004. Compared with GPB infections, a significant proportion of infections caused by Gram-negative bacteria was associated with a high bacterial load (HBL) (11 vs 28% in 1998 and 10 vs 30% in 2004; p<0.001). In 2004, BSI episodes due to non-Pseudomonas non-fermentative GNB (Stenotrophomonas maltophilia and Acinetobacter spp) were significantly associated with a HBL compared to BSI due to Pseudomonas aeruginosa (47 vs 23%; p<0.05); this was not the case in 1998. Conversely, the HBLs commonly associated with BSI due to Staphylococcus aureus (50%) and Streptococcus spp (35%) versus coagulase-negative staphylococci (13%; p<0.0001) during 1998 were not noted during 2004 (22% Staphylococcus aureus, 20% Streptococcus spp, 21% coagulase-negative staphylococci; p>0.5). The spectrum of BSI continues to change and its prognostic implications in cancer patients needs further study. PMID:16896827

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

    PubMed

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

    2012-12-01

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

  14. Antimicrobial activity of CS-940, a new trifluorinated quinolone.

    PubMed Central

    Biedenbach, D J; Sutton, L D; Jones, R N

    1995-01-01

    The antimicrobial activity of CS-940, a new trifluorinated quinolone drug, was tested against 761 clinical isolates. CS-940 activity against members of the family Enterobacteriaceae was most similar to that of ciprofloxacin and ofloxacin, with a large range of MICs inhibiting 90% of isolates tested (MIC90S) of 0.015 to 16 micrograms/ml (median MIC90, 0.06 micrograms/ml). CS-940 had greater activity than ciprofloxacin or ofloxacin when they were tested against Acinetobacter spp. (MIC90S, 0.03 micrograms/ml) and Stenotrophomonas (Xanthomonas) maltophilia (MIC90S, 2 micrograms/ml). CS-940 demonstrated a high degree of potency against Haemophilus influenzae, Moraxella catarrhalis, and Neisseria spp. (MIC90S, < or = 0.06 micrograms/ml). CS-940 was two- to eightfold more active than ciprofloxacin or ofloxacin against oxacillin-susceptible Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, and coagulase-negative Staphylococcus spp. CS-940 was also very active against Streptococcus spp. and enterococci, for which MIC90S were < or = 2 micrograms/ml; for Enterococcus faecium, however, the MIC90 was 4 micrograms/ml. CS-940 was generally less active than a comparison investigational fluoroquinolone, clinafloxacin. This compound appears promising by in vitro test analysis and warrants further in vivo trials. PMID:8619590

  15. 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

  16. Antibiotic Resistance and Extended-Spectrum β-Lactamases in Isolated Bacteria from Seawater of Algiers Beaches (Algeria)

    PubMed Central

    Alouache, Souhila; Kada, Mohamed; Messai, Yamina; Estepa, Vanesa; Torres, Carmen; Bakour, Rabah

    2012-01-01

    The aim of the study was to evaluate bacterial antibiotic resistance in seawater from four beaches in Algiers. The most significant resistance rates were observed for amoxicillin and ticarcillin, whereas they were relatively low for ceftazidime, cefotaxime and imipenem. According to sampling sites, the highest resistance rates were recorded for 2 sites subjected to chemical and microbiological inputs (amoxicillin, 43% and 52%; ticarcillin, 19.6% and 47.7%), and for 2 sites relatively preserved from anthropogenic influence, resistance rates were lowest (amoxicillin, 1.5% and 16%; ticarcillin, 0.8% and 2.6%). Thirty-four bacteria resistant to imipenem (n=14) or cefotaxime (n=20) were identified as Pseudomonas aeruginosa (n=15), Pseudomonas fluorescens(7), Stenotrophomonas maltophilia(4), Burkholderia cepacia(2), Bordetella sp. (1), Pantoea sp. (1), Acinetobacter baumannii(1), Chryseomonas luteola(1), Ochrobactrum anthropi(1) and Escherichia coli(1). Screening for extended spectrum β-lactamase showed the presence of CTX-M-15 β-lactamase in the E. coli isolate, and the encoding gene was transferable in association with the IncI1 plasmid of about 50 kbp. Insertion sequence ISEcp1B was located upstream of the CTX-M-15 gene. This work showed a significant level of resistance to antibiotics, mainly among environmental saprophytic bacteria. Transmissible CTX-M-15 was detected in E. coli; this may mean that contamination of the environment by resistant bacteria may cause the spread of resistance genes. PMID:22095134

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

    PubMed

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

    2006-09-01

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

  18. In Vitro Assessment of the Antimicrobial Efficacy of Optimized Nitroglycerin-Citrate-Ethanol as a Nonantibiotic, Antimicrobial Catheter Lock Solution for Prevention of Central Line-Associated Bloodstream Infections.

    PubMed

    Reitzel, Ruth A; Rosenblatt, Joel; Hirsh-Ginsberg, Cheryl; Murray, Kimberly; Chaftari, Anne-Marie; Hachem, Ray; Raad, Issam

    2016-09-01

    The rapid, broad-spectrum, biofilm-eradicating activity of the combination of 0.01% nitroglycerin, 7% citrate, and 20% ethanol and its potential as a nonantibiotic, antimicrobial catheter lock solution (ACLS) were previously reported. Here, a nitroglycerin-citrate-ethanol (NiCE) ACLS optimized for clinical assessment was developed by reducing the nitroglycerin and citrate concentrations and increasing the ethanol concentration. Biofilm-eradicating activity was sustained when the ethanol concentration was increased from 20 to 22% which fully compensated for reducing the citrate concentration from 7% to 4% as well as the nitroglycerin concentration from 0.01% to 0.0015% or 0.003%. The optimized formulations demonstrated complete and rapid (2 h) eradication of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-intermediate Staphylococcus aureus (VISA), methicillin-resistant Staphylococcus epidermidis (MRSE), vancomycin-resistant enterococci (VRE), multidrug-resistant (MDR) Pseudomonas aeruginosa, MDR Klebsiella pneumoniae, MDR Enterobacter cloacae, MDR Acinetobacter baumannii, MDR Escherichia coli, MDR Stenotrophomonas maltophilia, Candida albicans, and Candida glabrata biofilms. The optimized NiCE lock solutions demonstrated anticoagulant activities comparable to those of heparin lock solutions. NiCE lock solution was significantly more effective than taurolidine-citrate-heparin lock solution in eradicating biofilms of Staphylococcus aureus and Candida glabrata The optimized, nonantibiotic, heparin-free NiCE lock solution demonstrates rapid broad-spectrum biofilm eradication as well as effective anticoagulant activity, making NiCE a high-quality ACLS candidate for clinical assessment. PMID:27297475

  19. High-throughput determination of biochemical oxygen demand (BOD) by a microplate-based biosensor.

    PubMed

    Pang, Hei-Leung; Kwok, Nga-Yan; Chan, Pak-Ho; Yeung, Chi-Hung; Lo, Waihung; Wong, Kwok-Yin

    2007-06-01

    The use of the conventional 5-day biochemical oxygen demand (BOD5) method in BOD determination is greatly hampered by its time-consuming sampling procedure and its technical difficulty in the handling of a large pool of wastewater samples. Thus, it is highly desirable to develop a fast and high-throughput biosensor for BOD measurements. This paper describes the construction of a microplate-based biosensor consisting of an organically modified silica (ORMOSIL) oxygen sensing film for high-throughput determination of BOD in wastewater. The ORMOSIL oxygen sensing film was prepared by reacting tetramethoxysilane with dimethyldimethoxysilane in the presence of the oxygen-sensitive dye tris(4,7-diphenyl-1,10-phenanthroline)ruthenium-(II) chloride. The silica composite formed a homogeneous, crack-free oxygen sensing film on polystyrene microtiter plates with high stability, and the embedded ruthenium dye interacted with the dissolved oxygen in wastewater according to the Stern-Volmer relation. The bacterium Stenotrophomonas maltophilia was loaded into the ORMOSIL/ PVA composite (deposited on the top of the oxygen sensing film) and used to metabolize the organic compounds in wastewater. This BOD biosensor was found to be able to determine the BOD values of wastewater samples within 20 min by monitoring the dissolved oxygen concentrations. Moreover, the BOD values determined by the BOD biosensor were in good agreement with those obtained by the conventional BOD5 method.

  20. Blooms of Single Bacterial Species in a Coastal Lagoon of the Southwestern Atlantic Ocean

    PubMed Central

    Piccini, Claudia; Conde, Daniel; Alonso, Cecilia; Sommaruga, Ruben; Pernthaler, Jakob

    2006-01-01

    We investigated seasonal differences in community structure and activity (leucine incorporation) of the planktonic bacterial assemblage in the freshwater and brackish-water zones of a shallow coastal lagoon of the southwestern Atlantic Ocean. Alphaproteobacteria formed the dominant microbial group in both zones throughout the sampling period. After an intrusion of marine water, members of the SAR11 lineage became abundant in the brackish-water zone. These bacteria were apparently distributed over the lagoon during the following months until they constituted almost 30% of all prokaryotic cells at both sampling sites. At the first sampling date (March 2003) a single alphaproteobacterial species unrelated to SAR11, Sphingomonas echinoides, dominated the microbial assemblages in both zones of the lagoon concomitantly with a bloom of filamentous cyanobacteria. Pronounced maxima of leucine incorporation were observed once in each zone of the lagoon. In the freshwater zone, this highly active microbial assemblage was a mix of the typical bacteria lineages expected in aquatic systems. By contrast, a single bacterial genotype with >99% similarity to the facultative pathogen gammaproteobacterial species Stenotrophomonas maltophilia formed >90% of the bacterial assemblage (>107 cell ml−1) in the brackish-water zone at the time point of highest bacterial leucine incorporation. Moreover, these bacteria were equally dominant, albeit less active, in the freshwater zone. Thus, the pelagic zone of the studied lagoon harbored repeated short-term blooms of single bacterial species. This finding may have consequences for environmental protection. PMID:17021206

  1. Genetic diversity of phenazine- and pyoluteorin-producing pseudomonads isolated from green pepper rhizosphere.

    PubMed

    Liu, Haiming; Dong, Dexian; Peng, Huasong; Zhang, Xuehong; Xu, Yuquan

    2006-03-01

    The genetic diversity among indigenous phenazine-1-carboxylic acid (PCA)-producing and pyoluteorin (Plt)-producing isolates of pseudomonads screened from green pepper rhizosphere was exploited in this study. A total of 48 bacterium isolates producing one or both of these antibiotics were screened from green pepper rhizosphere in diverse regions in China. Among these isolates, 45 could produce PCA, 3 could produce both PCA and Plt, and none could produce Plt only. Based on the restriction patterns of partial 16S and 16S-23S internal transcribed spacer (ITS) PCR fragments generated by enzyme HaeIII or HinfI, these isolates fell into 19 or 17 distinct groups respectively, indicating that there was a significant diversity among them. Polygenetic analysis of the partial 16S rDNA and 16S-23S ITS sequence from the representative in each group in the context of similar sequence from previously described bacterial species indicated that most isolates were closely related to the species of Pseudomonas fluorescens, P. putida, and Stenotrophomonas maltophilia. Some of these representatives of these isolates, then, are likely to be novel strains or species in these two genera. PMID:16395554

  2. Characterization of copper-resistant rhizosphere bacteria from Avena sativa and Plantago lanceolata for copper bioreduction and biosorption.

    PubMed

    Andreazza, Robson; Okeke, Benedict C; Pieniz, Simone; Camargo, Flávio A O

    2012-04-01

    Copper is a toxic heavy metal widely used to microbial control especially in agriculture. Consequently, high concentrations of copper residues remain in soils selecting copper-resistant organisms. In vineyards, copper is routinely used for fungi control. This work was undertaken to study copper resistance by rhizosphere microorganisms from two plants (Avena sativa L. and Plantago lanceolata L.) common in vineyard soils. Eleven rhizosphere microorganisms were isolated, and four displayed high resistance to copper. The isolates were identified by 16S rRNA gene sequence analysis as Pseudomonas putida (A1), Stenotrophomonas maltophilia (A2) and Acinetobacter sp. (A6), isolated from Avena sativa rhizosphere, and Acinetobacter sp. (T5), isolated from Plantago lanceolata rhizosphere. The isolates displayed high copper resistance in the temperature range from 25°C to 35°C and pH in the range from 5.0 to 9.0. Pseudomonas putida A1 resisted as much as 1,000 mg L(-1) of copper. The isolates showed similar behavior on copper removal from liquid medium, with a bioremoval rate of 30% at 500 mg L(-1) after 24 h of growth. Speciation of copper revealed high copper biotransformation, reducing Cu(II) to Cu(I), capacity. Results indicate that our isolates are potential agents for copper bioremoval and bacterial stimulation of copper biosorption by Avena sativa and Plantago lanceolata.

  3. Polyphasic approach for the characterization of rhizobial symbionts effective in fixing N(2) with common bean (Phaseolus vulgaris L.).

    PubMed

    Cardoso, Juscélio Donizete; Hungria, Mariangela; Andrade, Diva S

    2012-03-01

    Common bean (Phaseolus vulgaris L.) is a legume that has been reported as highly promiscuous in nodulating with a variety of rhizobial strains, often with low effectiveness in fixing nitrogen. The aim of this work was to assess the symbiotic efficiency of rhizobial strains isolated from common bean seeds, nodules of Arachis hypogaea, Mucuna pruriens, and soils from various Brazilian agroecosystems, followed by the characterization of elite strains identified in the first screening. Forty-five elite strains were analyzed for symbiotic properties (nodulation, plant-growth, and nitrogen-fixation parameters) under greenhouse conditions in pots containing non-sterile soil, and variation in symbiotic performance was observed. Elite strains were also characterized in relation to morpho-physiological properties, genetic profiles of rep-polymerase chain reaction (PCR; BOX), and restriction fragment length polymorphism (RFLP)-PCR of the 16S rRNA. Sequence analyses of the 16S rRNA were obtained for 17 strains representative of the main groups resulting from all previous analyses. One of the most effective strains, IPR-Pv 2604, was clustered with Rhizobium tropici, whereas strain IPR-Pv 583, showing lower effectiveness in fixing N(2), was clustered with Herbaspirillum lusitanum. Surprisingly, effective strains were clustered with unusual symbiotic genera/species, including Leifsonia xyli, Stenotrophomonas maltophilia, Burkholderia, and Enterobacter. Some strains recognized in this study were outstanding in their nitrogen-fixing capacity and therefore, show high biotechnological potential for use in commercial inoculants. PMID:22159885

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

    PubMed

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

    2010-02-01

    A total of 364 bacterial isolates, obtained from spinach leaves, were assayed in a decarboxylase broth containing histidine, lysine, and ornithine to check their ability to produce biogenic amines, and then quantified by high-performance liquid chromatography. Among these isolates, 240 formed cadaverine, 208 formed putrescine, and 196 formed histamine, in widely varying amounts. They frequently produced more than one biogenic amine. Klebsiella pneumoniae subsp. pneumoniae and Morganella morganii were the main histamine producers, with mean values of 1,600 and 2,440 mg/liter, respectively, followed by Pantoea spp. 3 (1,710 mg/liter) and Hafnia alvei (2,500 mg/liter). Enterobacter amnigenus and Enterobacter cloacae produced particularly high amounts of putrescine, with mean values of 2,340 and 2,890 mg/liter, respectively. The strongest cadaverine formation was shown by Serratia liquefaciens (3,300 mg/liter), Serratia marcescens (3,280 mg/liter), and Stenotrophomonas maltophilia (1,000 mg/liter). PMID:20132689

  5. Evaluation of the effectiveness of manual and automated dialyzers reprocessing after multiple reuses.

    PubMed

    Toniolo, Alexandra do Rosário; Ribeiro, Maíra Marques; Ishii, Marina; da Silva, Cely Barreto; Jenné Mimica, Lycia Mara; Graziano, Kazuko Uchikawa

    2016-06-01

    A cross-sectional study was conducted to evaluate the effectiveness of manual and automated dialyzer reprocessing. Dialyzers were filled with fluid thioglycollate medium from blood and dialysate chambers after being reprocessed and chemically sterilized with 0.2% peracetic acid. They were incubated for 14 days at 35°C ± 2°C, and microbiologic analysis was performed. Microorganisms were identified in 3 of the 11 samples (27.3%) from the blood chambers: Sphingomonas paucimobilis (2/3) and Penicillium spp (1/3) and in 11 of the 11 samples (100%) from the dialysate chambers: S paucimobilis (7/11), Stenotrophomonas maltophilia (4/11), Pseudomonas aeruginosa (3/11), Candida spp (1/11), and Acinetobacter baumannii (1/11). Of the 4 manually reprocessed dialyzers, gram-positive bacillus were identified in 1 sample (25%) from the blood chamber, and Bacillus spp and Burkholderia spp were identified in 1 sample (25%) from the dialysate chamber. The dialyzers reprocessing can pose risks safety because of exposure patient to microorganisms. PMID:26897699

  6. Assessing the xylanolytic bacterial diversity during the malting process.

    PubMed

    Malfliet, Sofie; Justé, Annelies; Crauwels, Sam; Willems, Kris; De Cooman, Luc; Lievens, Bart; Aerts, Guido

    2013-12-01

    The presence of microorganisms producing cell wall hydrolyzing enzymes such as xylanases during malting can improve mash filtration behavior and consequently have potential for more efficient wort production. In this study, the xylanolytic bacterial community during malting was assessed by isolation and cultivation on growth media containing arabinoxylan, and identification by 16S rRNA gene sequencing. A total of 33 species-level operational taxonomic units (OTUs) were found, taking into account a 3% sequence dissimilarity cut-off, belonging to four phyla (Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria) and 25 genera. Predominant OTUs represented xylanolytic bacteria identified as Sphingobacterium multivorum, Stenotrophomonas maltophilia, Aeromonas hydrophila and Pseudomonas fulva. DNA fingerprinting of all xylanolytic isolates belonging to S. multivorum obtained in this study revealed shifts in S. multivorum populations during the process. Xylanase activity was determined for a selection of isolates, with Cellulomonas flavigena showing the highest activity. The xylanase of this species was isolated and purified 23.2-fold by ultrafiltration, 40% ammonium sulfate precipitation and DEAE-FF ion-exchange chromatography and appeared relatively thermostable. This study will enhance our understanding of the role of microorganisms in the barley germination process. In addition, this study may provide a basis for microflora management during malting.

  7. Genome Survey and Characterization of Endophytic Bacteria Exhibiting a Beneficial Effect on Growth and Development of Poplar Trees ▿ †

    PubMed Central

    Taghavi, Safiyh; Garafola, Craig; Monchy, Sébastien; Newman, Lee; Hoffman, Adam; Weyens, Nele; Barac, Tanja; Vangronsveld, Jaco; van der Lelie, Daniel

    2009-01-01

    The association of endophytic bacteria with their plant hosts has a beneficial effect for many different plant species. Our goal is to identify endophytic bacteria that improve the biomass production and the carbon sequestration potential of poplar trees (Populus spp.) when grown in marginal soil and to gain an insight in the mechanisms underlying plant growth promotion. Members of the Gammaproteobacteria dominated a collection of 78 bacterial endophytes isolated from poplar and willow trees. As representatives for the dominant genera of endophytic gammaproteobacteria, we selected Enterobacter sp. strain 638, Stenotrophomonas maltophilia R551-3, Pseudomonas putida W619, and Serratia proteamaculans 568 for genome sequencing and analysis of their plant growth-promoting effects, including root development. Derivatives of these endophytes, labeled with gfp, were also used to study the colonization of their poplar hosts. In greenhouse studies, poplar cuttings (Populus deltoides × Populus nigra DN-34) inoculated with Enterobacter sp. strain 638 repeatedly showed the highest increase in biomass production compared to cuttings of noninoculated control plants. Sequence data combined with the analysis of their metabolic properties resulted in the identification of many putative mechanisms, including carbon source utilization, that help these endophytes to thrive within a plant environment and to potentially affect the growth and development of their plant hosts. Understanding the interactions between endophytic bacteria and their host plants should ultimately result in the design of strategies for improved poplar biomass production on marginal soils as a feedstock for biofuels. PMID:19060168

  8. Pseudomonas aeruginosa Las quorum sensing autoinducer suppresses growth and biofilm production in Legionella species.

    PubMed

    Kimura, Soichiro; Tateda, Kazuhiro; Ishii, Yoshikazu; Horikawa, Manabu; Miyairi, Shinichi; Gotoh, Naomasa; Ishiguro, Masaji; Yamaguchi, Keizo

    2009-06-01

    Bacteria commonly communicate with each other by a cell-to-cell signalling mechanism known as quorum sensing (QS). Recent studies have shown that the Las QS autoinducer N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C(12)-HSL) of Pseudomonas aeruginosa performs a variety of functions not only in intraspecies communication, but also in interspecies and interkingdom interactions. In this study, we report the effects of Pseudomonas 3-oxo-C(12)-HSL on the growth and suppression of virulence factors in other bacterial species that frequently co-exist with Ps. aeruginosa in nature. It was found that 3-oxo-C(12)-HSL, but not its analogues, suppressed the growth of Legionella pneumophila in a dose-dependent manner. However, 3-oxo-C(12)-HSL did not exhibit a growth-suppressive effect on Serratia marcescens, Proteus mirabilis, Escherichia coli, Alcaligenes faecalis and Stenotrophomonas maltophilia. A concentration of 50 microM 3-oxo-C(12)-HSL completely inhibited the growth of L. pneumophila. Additionally, a significant suppression of biofilm formation was demonstrated in L. pneumophila exposed to 3-oxo-C(12)-HSL. Our results suggest that the Pseudomonas QS autoinducer 3-oxo-C(12)-HSL exerts both bacteriostatic and virulence factor-suppressive activities on L. pneumophila alone.

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

    PubMed

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

    2002-02-01

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

  10. Degradation and Mineralization of High-Molecular-Weight Polycyclic Aromatic Hydrocarbons by Defined Fungal-Bacterial Cocultures

    PubMed Central

    Boonchan, Sudarat; Britz, Margaret L.; Stanley, Grant A.

    2000-01-01

    This study investigated the biodegradation of high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) in liquid media and soil by bacteria (Stenotrophomonas maltophilia VUN 10,010 and bacterial consortium VUN 10,009) and a fungus (Penicillium janthinellum VUO 10,201) that were isolated from separate creosote- and manufactured-gas plant-contaminated soils. The bacteria could use pyrene as their sole carbon and energy source in a basal salts medium (BSM) and mineralized significant amounts of benzo[a]pyrene cometabolically when pyrene was also present in BSM. P. janthinellum VUO 10,201 could not utilize any high-molecular-weight PAH as sole carbon and energy source but could partially degrade these if cultured in a nutrient broth. Although small amounts of chrysene, benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene were degraded by axenic cultures of these isolates in BSM containing a single PAH, such conditions did not support significant microbial growth or PAH mineralization. However, significant degradation of, and microbial growth on, pyrene, chrysene, benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene, each as a single PAH in BSM, occurred when P. janthinellum VUO 10,201 and either bacterial consortium VUN 10,009 or S. maltophilia VUN 10,010 were combined in the one culture, i.e., fungal-bacterial cocultures: 25% of the benzo[a]pyrene was mineralized to CO2 by these cocultures over 49 days, accompanied by transient accumulation and disappearance of intermediates detected by high-pressure liquid chromatography. Inoculation of fungal-bacterial cocultures into PAH-contaminated soil resulted in significantly improved degradation of high-molecular-weight PAHs, benzo[a]pyrene mineralization (53% of added [14C]benzo[a]pyrene was recovered as 14CO2 in 100 days), and reduction in the mutagenicity of organic soil extracts, compared with the indigenous microbes and soil amended with only axenic inocula. PMID:10698765

  11. Evaluation of the DiversiLab system for detection of hospital outbreaks of infections by different bacterial species.

    PubMed

    Fluit, A C; Terlingen, A M; Andriessen, L; Ikawaty, R; van Mansfeld, R; Top, J; Cohen Stuart, J W; Leverstein-van Hall, M A; Boel, C H E

    2010-11-01

    Many bacterial typing methods are specific for one species only, time-consuming, or poorly reproducible. DiversiLab (DL; bioMérieux) potentially overcomes these limitations. In this study, we evaluated the DL system for the identification of hospital outbreaks of a number bacterial species. Appropriately typed clinical isolates were tested with DL. DL typing agreed with pulsed-field gel electrophoresis (PFGE) for Acinetobacter (n = 26) and Stenotrophomonas maltophilia (n = 13) isolates. With two exceptions, DL typing of Klebsiella isolates (n = 23) also correlated with PFGE, and in addition, PFGE-nontypeable (PFGE-NT) isolates could be typed. Enterobacter (n = 28) results also correlated with PFGE results; also, PFGE-NT isolates could be clustered. In a larger study (n = 270), a cluster of 30 isolates was observed that could be subdivided by PFGE. The results for Escherichia coli (n = 38) correlated less well with an experimental multilocus variable number of tandem repeats analysis (MLVA) scheme. Pseudomonas aeruginosa (n = 52) showed only a limited number of amplification products for most isolates. When multiple Pseudomonas isolates were assigned to a single type in DL, all except one showed multiple multilocus sequence types. Methicillin-resistant Staphylococcus aureus generally also showed a limited number of amplification products. Isolates that belonged to different outbreaks by other typing methods, including PFGE, spa typing, and MLVA, were grouped together in a number of cases. For Enterococcus faecium, the limited variability of the amplification products obtained made interpretation difficult and correlation with MLVA and esp gene typing was poor. All of the results are reflected in Simpson's index of diversity and adjusted Rand's and Wallace's coefficients. DL is a useful tool to help identify hospital outbreaks of Acinetobacter spp., S. maltophilia, the Enterobacter cloacae complex, Klebsiella spp., and, to a somewhat lesser extent, E. coli. In our

  12. 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

  13. 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

  14. Assessment of the Microbial Constituents of the Home Environment of Individuals with Cystic Fibrosis (CF) and Their Association with Lower Airways Infections

    PubMed Central

    Heirali, Alya; McKeon, Suzanne; Purighalla, Swathi; Storey, Douglas G.; Rossi, Laura; Costilhes, Geoffrey; Drews, Steven J.; Rabin, Harvey R.; Surette, Michael G.; Parkins, Michael D.

    2016-01-01

    Introduction Cystic fibrosis (CF) airways are colonized by a polymicrobial community of organisms, termed the CF microbiota. We sought to define the microbial constituents of the home environment of individuals with CF and determine if it may serve as a latent reservoir for infection. Methods Six patients with newly identified CF pathogens were included. An investigator collected repeat sputum and multiple environmental samples from their homes. Bacteria were cultured under both aerobic and anaerobic conditions. Morphologically distinct colonies were selected, purified and identified to the genus and species level through 16S rRNA gene sequencing. When concordant organisms were identified in sputum and environment, pulsed-field gel electrophoresis (PFGE) was performed to determine relatedness. Culture-independent bacterial profiling of each sample was carried out by Illumina sequencing of the V3 region of the 16s RNA gene. Results New respiratory pathogens prompting investigation included: Mycobacterium abscessus(2), Stenotrophomonas maltophilia(3), Pseudomonas aeruginosa(3), Pseudomonas fluorescens(1), Nocardia spp.(1), and Achromobacter xylosoxidans(1). A median 25 organisms/patient were cultured from sputum. A median 125 organisms/home were cultured from environmental sites. Several organisms commonly found in the CF lung microbiome were identified within the home environments of these patients. Concordant species included members of the following genera: Brevibacterium(1), Microbacterium(1), Staphylococcus(3), Stenotrophomonas(2), Streptococcus(2), Sphingomonas(1), and Pseudomonas(4). PFGE confirmed related strains (one episode each of Sphinogomonas and P. aeruginosa) from the environment and airways were identified in two patients. Culture-independent assessment confirmed that many organisms were not identified using culture-dependent techniques. Conclusions Members of the CF microbiota can be found as constituents of the home environment in individuals with

  15. 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.

  16. Pathogen distribution and drug resistance in a burn ward: a three-year retrospective analysis of a single center in China

    PubMed Central

    Cen, Hanghui; Wu, Zhenbo; Wang, Fan; Han, Chunmao

    2015-01-01

    To investigate the spread of multiple-resistant strain in a burn ward to inform clinical administration of antibiotic drugs, burn wound treatment and decision-making for infection control. A 3-year retrospective analysis was conducted. Specimens from wounds, blood, catheter, sputum, urine and stool collected from inpatients of the Second Affiliated Hospital of Zhejiang University of Medicine between January 1, 2011 and December 31, 2013 were cultured and strains were identified by automatic bacteria analysis. Sensitivity to 30 commonly used antibiotics was assessed by K-B disk diffusion. A total of 2212 strains of pathogenic bacteria or fungi were isolated (33.9% Gram-positive and 52.7% Gram-negative bacteria and 13.4% fungi), including 1466 from wound extracts, 128 from blood culture, 335 from urine culture, 5 from stool culture, 153 from sputum culture and 125 from catheters. The most frequently detected pathogens in wound secretions were Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii. The Gram-positive bacteria Staphylococcus epidermidis, Enterococcus faecalis and Enterococcus faecium, and the Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Stenotrophomonas maltophilia, Proteus mirabilis were also frequently detected. The most frequently detected strains of fungi were Candida albicans; tropicalis, glabrata and parapsilosis, and all were highly sensitive to itraconazole, fluconazole and voriconazole but resistant to ketoconazole. Attention should be paid to MRSA, multi-resistant A. baumanni, ESBL-producing enterobacteriaceae and Carbapenem-resistant P. aeruginosa. Understanding the distribution of bacterial infections in Chinese hospitals will be crucial to reduce hospital-acquired infection and drug resistance. PMID:26770555

  17. Abundance and diversity of biofilms in natural and artificial aquifers of the Äspö Hard Rock Laboratory, Sweden.

    PubMed

    Jägevall, Sara; Rabe, Lisa; Pedersen, Karsten

    2011-02-01

    Six cores were drilled and retrieved from 186-m depth in the Äspö Hard Rock Laboratory (HRL) tunnel to investigate whether indigenous biofilms develop on fracture surfaces in groundwater-conducting aquifers in granitic rock. A clone library was constructed from fracture surface material (FSM), for community composition analysis. Quantitative polymerase chain reaction (qPCR) was applied to quantify gene copies using the 16S rRNA gene for domain Bacteria and the adenosine-phosphosulfate reductase gene (apsA) for sulfate-reducing bacteria (SRB). Results were compared with three groundwater systems with biofilms in laminar flow reactors (LFRs) at 450-m depth in the Äspö HRL. The total number of cells, counted microscopically, was approximately 2 × 10(5) cells cm(-2) in the LFR systems, consistent with the obtained qPCR 16S rRNA gene copies. qPCR analysis reported ∼1 × 10(2) up to ∼1 × 10(4) gene copies cm(-2) on the FSM from the drill cores. In the FSM biofilms, 33% of the sequenced clones were related to the iron-reducing bacterium Stenotrophomonas maltophilia, while in the LFR biofilms, 41% of the sequenced clones were affiliated with the genera Desulfovibrio, Desulforhopalus, Desulfomicrobium, and Desulfobulbus. The community composition of the FSM biofilms differed from the drill water community, excluding drill water contamination. This work reports significant numbers of microorganisms on natural hard rock aquifer fracture surfaces with site-specific community compositions. The probability that biofilms are generally present in groundwater-conducting aquifers in deep granitic rock is consequently great.

  18. 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

  19. Antibacterial Activity of Salvadora persica L. (Miswak) Extracts against Multidrug Resistant Bacterial Clinical Isolates

    PubMed Central

    Al-Ayed, Mohamed Saeed Zayed; Asaad, Ahmed Morad; Qureshi, Mohamed Ansar; Attia, Hany Goda; AlMarrani, Abduljabbar Hadi

    2016-01-01

    Much effort has focused on examining the inhibitory effect of Salvadora persica (miswak) on oral microorganisms, but information concerning its antibacterial activity against other human pathogens, particularly multidrug resistant (MDR) isolates, is scarce. Therefore, this study aimed to assess the in vitro antibacterial activities of Salvadora persica L. extracts against 10 MDR bacterial clinical isolates other than oral pathogens. The antibacterial activity of aqueous and methanol miswak extracts was assessed using the agar dilution and minimum inhibitory concentration (MIC) methods. Overall, the 400 mg/mL of miswak extract was the most effective on all strains. The methanol extract exhibited a stronger antibacterial activity against Gram-negative (3.3–13.6 mm) than Gram-positive (1.8–8.3 mm) bacteria. The lowest MIC value was seen for E. coli (0.39, 1.56 µg/mL), followed by Streptococcus pyogenes (1.56 µg/mL). The highest MIC value (6.25, 12.5 µg/mL) was recorded for methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumannii, and Stenotrophomonas maltophilia. This study demonstrates, for the first time, the moderate to strong antibacterial activity of miswak extracts against all tested MDR-pathogens. Methanol extract appears to be a potent antimicrobial agent that could be considered as complementary and alternative medicine against resistant pathogens. Further studies on a large number of MDR organisms are necessary to investigate and standardize the inhibitory effect of miswak extracts against these emerging pathogens. PMID:26904146

  20. New insight into microbial diversity and functions in traditional Vietnamese alcoholic fermentation.

    PubMed

    Thanh, Vu Nguyen; Thuy, Nguyen Thanh; Chi, Nguyen Thuy; Hien, Dinh Duc; Ha, Bui Thi Viet; Luong, Dao Thi; Ngoc, Pham Duc; Ty, Pham Van

    2016-09-01

    The roles of microorganisms in traditional alcoholic fermentation are often assumed based on abundance in the starter and activity in pure culture. There is a serious lack of hard evidence on the behavior and activity of individual microbial species during the actual fermentation process. In this study, microbial succession and metabolite changes during 7days of traditional Vietnamese alcoholic fermentation were monitored. Special attention was devoted to starch degradation. In total, 22 microbial species, including 6 species of filamentous fungi (Rhizopus microsporus, Rhizopus arrhizus, Mucor indicus, Mucor circinelloides, Cunninghamella elegans, Aspergillus niger), 1 yeast-like fungus (Saccharomycopsis fibuligera), 7 yeasts (Saccharomyces cerevisiae, Clavispora lusitaniae, Wickerhamomyces anomalus, Lindnera fabianii, Pichia kudriavzevii, Candida rugosa, Candida tropicalis), and 8 bacteria (Stenotrophomonas maltophilia, Lactobacillus brevis, Lactobacillus helveticus, Acinetobacter baumannii, Staphylococcus hominis, Bacillus megaterium, Enterobacter asburiae, Pediococcus pentosaceus) were identified. Despite the presence of a complex microbiota in the starter, the fermentation process is consistent and involves a limited number of functional species. Rapid change in microbial composition of fermentation mash was observed and it was correlated with ethanol content. Microbial biomass reached maximum during first 2days of solid state fermentation. Acidification of the medium took place in day 1, starch degradation in days 2, 3, 4, and alcohol accumulation from day 3. Although Sm. fibuligera dominated by cell count amongst potential starch degraders, zymography indicated that it did not produce amylase in the fermentation mash. In mixed culture with Rhizopus, amylase production by Sm. fibuligera is regulated by the moisture content of the substrate. Rhizopus was identified as the main starch degrader and S. cerevisiae as the main ethanol producer. Bacterial load was

  1. Seasonal variation in detection of bacterial DNA in arthritic stifle joints of dogs with cranial cruciate ligament rupture using PCR amplification of the 16S rRNA gene.

    PubMed

    Muir, Peter; Fox, Robin; Wu, Qiang; Baker, Theresa A; Zitzer, Nina C; Hudson, Alan P; Manley, Paul A; Schaefer, Susan L; Hao, Zhengling

    2010-02-24

    An underappreciated cause and effect relationship between environmental bacteria and arthritis may exist. Previously, we found that stifle arthritis in dogs was associated with the presence of environmental bacteria within synovium. Cranial cruciate ligament rupture (CCLR) is often associated with stifle arthritis in dogs. We now wished to determine whether seasonal variation in detection of bacterial material may exist in affected dogs, and to also conduct analyses of both synovium and synovial fluid. We also wished to analyze a larger clone library of the 16S rRNA gene to further understanding of the microbial population in the canine stifle. Synovial biopsies were obtained from 117 affected dogs from January to December 2006. Using PCR, synovium and synovial fluid were tested for Borrelia burgdorferi and Stenotrophomonas maltophilia DNA. Broad-ranging 16S rRNA primers were also used and PCR products were cloned and sequenced for bacterial identification. Overall, 41% of arthritic canine stifle joints contained bacterial DNA. Detection of bacterial DNA in synovial fluid samples was increased, when compared with synovium (p<0.01). Detection rates were highest in the winter and spring and lowest in the summer period, suggesting environmental factors influence the risk of translocation to the stifle. Organisms detected were predominately Gram's negative Proteobacteria, particularly the orders Rhizobiales (32.8% of clones) and Burkholderiales (20.0% of clones), usually as part of a polymicrobial population. PCR-positivity was inversely correlated with severity of arthritis assessed radiographically and with dog age. Bacterial translocation to the canine stifle may be associated with changes to the indoor environment. PMID:19758772

  2. Antimicrobial activity of novel nanostructured Cu-SiO2 coatings prepared by chemical vapour deposition against hospital related pathogens

    PubMed Central

    2013-01-01

    There is increasing recognition that the healthcare environment acts as an important reservoir for transmission of healthcare acquired infections (HCAI). One method of reducing environmental contamination would be use of antimicrobial materials. The antimicrobial activity of thin silica-copper films prepared by chemical vapour deposition was evaluated against standard strains of bacteria used for disinfectant testing and bacteria of current interest in HCAI. The structure of the coatings was determined using Scanning Electron Microscopy and their hardness and adhesion to the substrate determined. Antimicrobial activity was tested using a method based on BS ISO 22196:2007. The coatings had a pale green-brown colour and had a similar hardness to steel. SEM showed nano-structured aggregates of Cu within a silica matrix. A log10 reduction in viability of >5 could be obtained within 4 h for the disinfectant test strains and within 6 h for producing Acinetobacter baumannii, Klebsiella pneumoniae and Stenotrophomonas maltophilia. Activity against the other hospital isolates was slower but still gave log10 reduction factors of >5 for extended spectrum β-lactamase producing Escherichia coli and >3 for vancomycin resistant Enterococcus faecium, methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa within 24 h. The results demonstrate the importance of testing antimicrobial materials destined for healthcare use against isolates of current interest in hospitals as well as standard test strains. The coatings used here can also be applied to substrates such as metals and ceramics and have potential applications where reduction of microbial environmental contamination is desirable. PMID:24007899

  3. Count, identification and antimicrobial susceptibility of bacteria recovered from dental solid waste in Brazil.

    PubMed

    Vieira, Cristina Dutra; de Carvalho, Maria Auxiliadora Roque; Cussiol, Noil Amorim de Menezes; Alvarez-Leite, Maria Eugênia; dos Santos, Simone Gonçalves; Gomes, Renata Maria da Fonseca; Silva, Marcos Xavier; Nicoli, Jacques Robert; Farias, Luiz de Macêdo

    2011-06-01

    In Brazil, few studies on microbial content of dental solid waste and its antibiotic susceptibility are available. An effort has been made through this study to evaluate the hazardous status of dental solid waste, keeping in mind its possible role in cross-infection chain. Six samples of solid waste were collected at different times and seasons from three dental health services. The microbial content was evaluated in different culture media and atmospheric conditions, and the isolates were submitted to antibiotic susceptibility testing. A total of 766 bacterial strains were isolated and identified during the study period. Gram-positive cocci were the most frequent morphotype isolated (48.0%), followed by Gram-negative rods (46.2%), Gram-positive rods (5.0%), Gram-negative-cocci (0.4%), and Gram-positive coccobacillus (0.1%). Only two anaerobic bacteria were isolated (0.3%). The most frequently isolated species was Staphylococcus epidermidis (29.9%), followed by Stenotrophomonas maltophilia (8.2%), and Enterococcus faecalis (6.7%). High resistance rate to ampicillin was observed among Gram-negative rods (59.4%) and Gram-positive cocci (44.4%). For Gram-negative rods, high resistance was also noted to aztreonam (47.7%), cefotaxime (47.4%), ceftriaxone and cefazolin (43.7%), and ticarcillin-clavulanic acid (38.2%). Against Gram-positive cocci penicillin exhibit a higher resistance rate (45.0%), followed by ampicillin, erythromycin (27.2%), and tetracycline (22.0%). The present study demonstrated that several pathogenic bacteria are present in dental solid waste and can survive after 48 h from the waste generation time and harbor resistance profiles against several clinical recommended antibiotics.

  4. Isolation of UV-B resistant bacteria from two high altitude Andean lakes (4,400 m) with saline and non saline conditions.

    PubMed

    Flores, María R; Ordoñez, Omar F; Maldonado, Marcos J; Farías, María E

    2009-12-01

    Laguna (L.) Negra and L. Verde are high altitude Andean lakes located at the 4,400 m altitude in the Andean desert (Puna) in the Argentine northwest. Both lakes are exposed to extreme weather conditions but differ in salinity contents (salinity 6.7% for L. Negra and 0.27% for L. Verde). The aim of this work was to isolate ultraviolet B fraction (UV-B) resistant bacteria under UV-stress in order to determine, a possible connection, between resistance to UV-B and tolerance to salinity. DNA damage was determined by measuring CPDs accumulation. Connection among pigmentation production and UV resistance was also studied. Water samples were exposed to artificial UV-B radiation for 24 h. Water aliquots were plated along the exposition on different media, with different salinity and carbon source content (Lake medium (LM) done with the lake water plus agar and LB). CFU were counted and DNA damage accumulation was determined. Isolated bacteria were identified by 16S rDNA sequence. Their salinity tolerance, were measured at 1, 5 and 10% NaCl and their pigment production in both media was determined. In general it was found that UV resistance and pigment production were the optimum in Lake Medium done with lake water which maintained similar salinity. The most resistant bacteria in L. Negra were different strains of Exiguobacterium sp. and, in L. Verde, Staphylococcus sp. and Stenotrophomonas maltophilia. These bacteria showed the production and increase of UV-Vis absorbing compounds under UV stress and in LM. Bacterial communities from both lakes were well adapted to high UV-B exposure under the experimental conditions, and in many cases UV-B even stimulated growth. The idea that resistance to UV-B could be related to adaptation to high salinity is still an open question that has to be answered with future experiments. PMID:20118609

  5. Plasmid-mediated high-level gentamicin resistance among enteric bacteria isolated from pet turtles in Louisiana.

    PubMed

    Díaz, María Alejandra; Cooper, Richard Kent; Cloeckaert, Axel; Siebeling, Ronald John

    2006-01-01

    The sale of small turtles is banned by the Food and Drug Administration from the U.S. market due to concerns about their excretion of Salmonella spp. To produce a safe pet for the export market, the Louisiana pet turtle industry uses gentamicin sulfate baths (1,000 microg/ml) to eradicate Salmonella spp. from turtle eggs. In 1999, we analyzed bacterial samples recovered from turtle farms and found that strains of Salmonella enterica subsp. arizonae and other bacteria, such as Enterobacter cloacae, Citrobacter freundii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia, were resistant to high concentrations of gentamicin (>2,000 microg/ml) and to other aminoglycosides. The goal of this study was to identify the gene(s) which contributes to the high-level gentamicin resistance phenotype observed in bacteria from environmental samples with turtle farming activity, particularly the salmonellae, and to estimate the incidence of such genes in these bacteria. R plasmids from gentamicin-resistant strains were transferred by conjugation and transformation to naive Escherichia coli cells. Cloning and sequencing of the gentamicin resistance determinants on these plasmids revealed the presence of the aminoglycoside acetyltransferase genes aac(3)-IIa and aac(3)-VIa; the latter was present as a gene cassette of a class 1 integron. Multiplex PCR assays showed that every gentamicin-resistant isolate carried one of these acetyltransferase genes. Pulsed-field gel electrophoresis and restriction enzyme digestion analysis of R plasmids carrying these genes revealed different restriction profiles and sizes, indicating a dissemination of the gentamicin resistance genes through mobile molecular elements. The data presented highlight the need to develop an alternate method for the eradication of Salmonella spp. from turtle eggs. PMID:16391058

  6. ['In vitro' activity of different antimicrobial agents on Gram-negative nonfermentative bacilli, excluding Pseudomonas aeruginosa and Acinetobacter spp].

    PubMed

    Vay, C A; Almuzara, M N; Rodríguez, C H; Pugliese, M L; Lorenzo Barba, F; Mattera, J C; Famiglietti, A M R

    2005-01-01

    Gram-negative nonfermentative bacilli (NFB) are widely spread in the environment. Besides of difficulties for identification, they often have a marked multiresistance to antimicrobial agents, including those active against Pseudomonas aeruginosa. The objective of this study was to evaluate the 'in vitro' activity of different antimicrobial agents on 177 gram-negative nonfermentative bacilli isolates (excluding Pseudomonas aeruginosa and Acinetobacter spp.) isolated from clinical specimens. Minimum inhibitory concentrations (MIC) were determined according to the Mueller Hinton agar dilution method against the following antibacterial agents: ampicillin, piperacillin, piperacillin-tazobactam, sulbactam, cefoperazone, cefoperazone-sulbactam, ceftazidime, cefepime, aztreonam, imipenem, meropenem, colistin, gentamicin, amikacin, trimethoprim-sulfamethoxazole, chloramphenicol, erythromycin, rifampin, norfloxacin, ciprofloxacin and minocycline. Seven isolates: Sphingobacterium multivorum (2), Sphingobacteriumspiritivorum (1), Empedobacterbrevis (1), Weeksella virosa (1), Bergeyella zoohelcum (1) and Oligella urethralis (1), were tested for amoxicillin-clavulanic acid and ampicillin-sulbactam susceptibility, and susceptibility to cefoperazone or sulbactam was not determined. Multiresistance was generally found in Stenotrophomonas maltophilia, Burkholderia cepacia, Chryseobacterium spp., Myroides spp., Achromobacter xylosoxidans, and Ochrobactrum anthropi isolates. On the other hand, Pseudomonas stutzeri, Shewanella putrefaciens-algae, Sphingomonas paucimobilis, and Pseudomonas oryzihabitans, Bergeyella zoohelcum, Weeksella virosa and Oligella urethralis were widely susceptible to the antibacterial agents tested. As a result of the wide variation in antimicrobial susceptibility shown by different species, a test on susceptibility to different antibacterial agents is essential in order to select an adequate therapy. The marked multiresistance evidenced by some species

  7. 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.

  8. AmpG is required for BlaXc beta-lactamase expression in Xanthomonas campestris pv. campestris str. 17.

    PubMed

    Yang, Tsuey-Ching; Chen, Tzu-Fan; Tsai, Jeffrey J P; Hu, Rouh-Mei

    2013-03-01

    The chromosomal ampR(Xc) -bla(Xc) module is essential for the β-lactam resistance of Xanthomonas campestris pv. campestris. Bla(Xc) β-lactamase is expressed at a high basal level in the absence of an inducer and its expression can be further induced by β-lactam. In enterobacteria, ampG encodes an inner membrane facilitator involved in the recycling of murein degradation compounds. An isogenic ampG mutant (XcampG) of X. campestris pv. campestris str. 17 (Xc17) was constructed to investigate the link between murein recycling and bla(Xc) expression. Our data demonstrate that (1) XcampG is susceptible to β-lactam antibiotics; (2) AmpG(Xc) is essential for expression of bla(Xc) ; (3) AmpGs of Xc17, Stenotrophomonas maltophilia KJ (SmKJ) and Escherichia coli DH5α can complement the defect of XcampG; (4) overexpression of AmpG(X) (c) significantly increased bla(Xc) expression; and (5) AmpG(Xc) from Xc17 is able to restore β-lactamase induction of the ampN(Xc) -ampG(Xc) double mutant of SmKJ. In Xc17, ampG(Xc) can be expressed from the promoter residing in the intergenic region of ampN(Xc) -ampG(Xc) and the expression is independent of β-lactam induction. AmpN, which is required for β-lactamases induction in SmKJ, is not required for the β-lactam antibiotic resistance of Xc17.

  9. Microbiological investigation of Raphanus sativus L. grown hydroponically in nutrient solutions contaminated with spoilage and pathogenic bacteria.

    PubMed

    Settanni, Luca; Miceli, Alessandro; Francesca, Nicola; Cruciata, Margherita; Moschetti, Giancarlo

    2013-01-01

    The survival of eight undesired (spoilage/pathogenic) food related bacteria (Citrobacter freundii PSS60, Enterobacter spp. PSS11, Escherichia coli PSS2, Klebsiella oxytoca PSS82, Serratia grimesii PSS72, Pseudomonas putida PSS21, Stenotrophomonas maltophilia PSS52 and Listeria monocytogenes ATCC 19114(T)) was investigated in mineral nutrient solution (MNS) during the crop cycle of radishes (Raphanus sativus L.) cultivated in hydroponics in a greenhouse. MNSs were microbiologically analyzed weekly by plate count. The evolution of the pure cultures was also evaluated in sterile MNS in test tubes. The inoculated trials contained an initial total mesophilic count (TMC) ranging between 6.69 and 7.78Log CFU/mL, while non-sterile and sterile control trials showed levels of 4.39 and 0.97Log CFU/mL, respectively. In general, all inoculated trials showed similar levels of TMC in MNS during the experimentation, even though the levels of the inoculated bacteria decreased. The presence of the inoculums was ascertained by randomly amplified polymorphic DNA (RAPD) analysis applied on the isolates collected at 7-day intervals. At harvest, MNSs were also analyzed by denaturing gradient gel electrophoresis (DGGE). The last analysis, except P. putida PSS21 in the corresponding trial, did not detect the other bacteria, but confirmed that pseudomonads were present in un-inoculated MNSs. Despite the high counts detected (6.44 and 7.24CFU/g), only C. freundii PSS60, Enterobacter spp. PSS11 and K. oxytoca PSS82 were detected in radishes in a living form, suggesting their internalization.

  10. The in-vitro activity of faropenem, a novel oral penem.

    PubMed

    Woodcock, J M; Andrews, J M; Brenwald, N P; Ashby, J P; Wise, R

    1997-01-01

    The in-vitro activity of faropenem, a novel oral penem, was studied in comparison with other beta-lactam antimicrobials against 711 recent clinical isolates including Gram-negative, Gram-positive and anaerobic bacteria. MIC data showed that faropenem was active against most members of the Enterobacteriaceae (MICs < or = 4 mg/L), with reduced activity against Serratia spp. (MIC90 = 32 mg/L). In common with its comparators, faropenem had weak activity against Pseudomonas aeruginosa and Stenotrophomonas maltophilia (MIC > 128 mg/L). Faropenem was active against staphylococci, although for MRSA MICs were raised (MIC90 = 2 mg/L) compared with those for MSSA (MIC90 = 0.12 mg/L). Faropenem was also found to be active against streptococci, Neisseria spp., Enterococcus faecalis and beta-lactamase-producing and non-producing strains of Haemophilus influenzae and Moraxella catarrhalis. Of the anaerobic bacteria studied, faropenem was most active against peptostreptococci and Clostridium perfringens (MIC90 < or = 1 mg/L) and Bacteroides fragilis (MIC90 = 4 mg/L). An increase in inoculum from 10(4) to 10(6) cfu raised faropenem MICs for Morganella morganii from 0.06-1 mg/L to 2-4 mg/L and for MRSA from 0.25-2 mg/L to 8 mg/L (a similar increase was not observed for MSSA). The MICs of faropenem were not affected by the presence of either 20% or 70% (v/v) serum. MICs for faropenem to 11 well characterized beta-lactamase producers were similar to those of non-producers. In hydrolysis studies, faropenem was shown to be highly stable to a number of beta-lactamases, including TEM-1, SHV-1, the extended spectrum beta-lactamases, TEM-3 and TEM-9, and the beta-lactamase produced by Staphylococcus aureus (NCTC 11561). PMID:9044026

  11. Faropenem: review of a new oral penem.

    PubMed

    Schurek, Kristen N; Wiebe, Ryan; Karlowsky, James A; Rubinstein, Ethan; Hoban, Daryl J; Zhanel, George G

    2007-04-01

    Faropenem medoxomil is a new orally administered penem antibiotic. Its chiral tetrahydrofuran substituent at position C2 is responsible for its improved chemical stability and reduced CNS effects, compared with imipenem. Faropenem demonstrates broad-spectrum in vitro antimicrobial activity against many Gram-positive and -negative aerobes and anaerobes, and is resistant to hydrolysis by nearly all beta-lactamases, including extended-spectrum beta-lactamases and AmpC beta-lactamases. However, faropenem is not active against methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, Pseudomonas aeruginosa or Stenotrophomonas maltophilia. Prospective, multicenter, randomized, double-blind, comparative (not vs placebo) clinical trials of acute bacterial sinusitis (ABS), acute exacerbations of chronic bronchitis (AECB), community-acquired pneumonia (CAP) and uncomplicated skin and skin structure infections (uSSSIs) have demonstrated that faropenem medoxomil has equivalent efficacy and safety compared with cefuroxime, clarithromycin, azithromycin, amoxicillin, cefpodoxime and amoxicillin-clavulanate. The evidence supports faropenem medoxomil as a promising new oral beta-lactam with proven efficacy and safety for the treatment of a variety of community-acquired infections. However, the US FDA recently rejected faropenem for all four indications stating that the clinical trials in ABS and AECB should have been performed versus a placebo. In the CAP studies, the FDA stated that they could not be certain of the validity of the study population actually having the disease and for uSSSI, the FDA stated that only a single trial was not adequate evidence of efficacy for this indication. PMID:17402834

  12. Detection of extended spectrum β-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

  13. Assessment of the Phoenix™ automated system and EUCAST breakpoints for antimicrobial susceptibility testing against isolates expressing clinically relevant resistance mechanisms.

    PubMed

    Giani, T; Morosini, M I; D'Andrea, M M; García-Castillo, M; Rossolini, G M; Cantón, R

    2012-11-01

    EUCAST breakpoint criteria are being adopted by automatic antimicrobial susceptibility testing systems. The accuracy of the Phoenix Automated System in combination with 2012 EUCAST breakpoints against recent clinical isolates was evaluated. A total of 697 isolates (349 Enterobacteriaceae, 113 Pseudomonas spp., 25 Acinetobacter baumannii, 11 Stenotrophomonas maltophilia, 95 Staphylococcus aureus, 6 coagulase negative staphylococci, 77 enterococci and 21 Streptococcus pneumoniae) with defined resistance phenotypes and well-characterized resistance mechanisms recovered in Spain (n = 343) and Italy (n = 354) were tested. Comparator antimicrobial susceptibility testing data were obtained following CLSI guidelines. Experimental agreement (EA), defined as MIC agreement ±1 log(2) dilution, category agreement (CA) and relative discrepancies (minor (mD), major (MD) and very major discrepancies (VMD)) were determined. The overall EA and CA for all organism-antimicrobial agent combinations (n = 6.294) were 97.3% and 95.2%, respectively. mD, MD and VMD were 4.7%, 1.3% and 2.7%, all of them in agreement with the ISO (ISO20776-2:2007) acceptance criteria for assessment of susceptibility testing devices. VMD were mainly observed in amoxicillin-clavulanate and cefuroxime in Enterobacteriaceae and gentamicin in Pseudomonas aeruginosa, whereas MD were mainly observed in amoxicillin-clavulante in Enterobacteriaceae. mD were mainly observed in Enterobacteriaceae but distributed in different antimicrobials. For S. aureus and enterococci relative discrepancies were low. The Phoenix system showed accuracy assessment in accordance with the ISO standards when using EUCAST breakpoints. Inclusion of EUCAST criteria in automatic antimicrobial susceptibility testing systems will facilitate the implementation of EUCAST breakpoints in clinical microbiology laboratories.

  14. [Utility of prolonged incubation and terminal subcultures of blood cultures from immunocompromised patients].

    PubMed

    Soloaga, R; Procopio, A; Manganello, S; Ivanovic, V; Romay, N; Pirosanto, Y; Fernández, A; Zudiker, R; Echeverría, A; Nagel, C; del Castillo, M; López, E; Gutfraind, Z; Tokumoto, M; Guelfand, L

    2001-01-01

    The value of blind terminal subcultures (7 and 30 days) and prolonged incubation (30 days) of blood cultures from immunosuppressed patients was analyzed in the Fundación Favaloro, the Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia and the Hospital de Niños Ricardo Gutiérrez. A total of 2707 blood cultures and 369 patients were included (transplantation of solid organs 154, oncohematologic disorders 106 and solid tumors 109). Bact-Alert bottles were incubated at 35 degrees C for 30 days in the Bact-Alert System. Bottles with positive signals were routinely removed, and aliquots of the broth were Gram stained and subcultured aerobically in chocolate agar and Sabouraud agar. A total of 136 bacteremic episodes were obtained. The positivization time of blood cultures was 81.6% at 24 h, 93.3% at 48 h, 94.5% at 72 h and 97.7% within 7 days. Only 3 (2.2%) episodes were positive by blind terminal subcultures and 1 (0.75%) by prolonged incubation (14 days). The median time and range of positivization in hours were 13.8 and 2.2-168, respectively. The microorganisms isolated were coagulase negative staphylococci (n = 24), Klebsiella pneumoniae (n = 22), Staphylococcus aureus (n = 21), Escherichia coli (n = 18), Acinetobacter spp (n = 9), Candida spp (n = 8), Pseudomonas aeruginosa (n = 6), Enterobacter cloacae (n = 5), Stenotrophomonas maltophilia (n = 5), Enterococcus faecalis, Salmonella spp and Capnocytophaga sputigena (n = 2), Enterobacter aerogenes, Enterococcus faecium, Citrobacter diversus, Candida albicans, Klebsiella oxytoca, Chryseomonas luteola, Serratia marcescens, Abiotrophia spp, Campylobacter jejuni, Moraxella catarrhalis, Moraxella urethralis, Neisseria sicca, beta hemolytic group G streptococci, Rhodococcus equi, Micrococcus spp, Cryptococcus neoformans and Streptococcus mitis (n = 1). In our experience, blind terminal subcultures and prolonged incubation of blood cultures from immunosuppressed patients are unnecessary and

  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

  16. 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.

  17. Bacterial reduction of selenium in coal mine tailings pond sediment

    SciTech Connect

    Siddique, T.; Arocena, J.M.; Thring, R.W.; Zhang, Y.Q.

    2007-05-15

    Sediment from a storage facility for coal tailings solids was assessed for its capacity to reduce selenium (Se) by native bacterial community. One Se{sup 6+}-reducing bacterium Enterobacter hormaechei (Tar11) and four Se{sup 4+}-reducing bacteria, Klebsiella pneumoniae (Tar1), Pseudomonasfluorescens (Tar3), Stenotrophomonas maltophilia (Tar6), and Enterobacter amnigenus (Tar8) were isolated from the sediment. Enterobacter horinaechei removed 96% of the added Se{sup 6+} (0.92 mg L{sup -1} from the effluents when Se6+ was determined after 5 d of incubation. Analysis of the red precipitates showed that Se{sup 6+} reduction resulted in the formation of spherical particles ({lt}1.0 {mu} m) of Se 0 as observed under scanning electron microscope (SEM) and confirmed by EDAX. Selenium speciation was performed to examine the fate of the added Se{sup 6+} in the sediment with or without addition of Enterobacter hormaechei cells. More than 99% of the added Se{sup 6+} (about 2.5 mg L{sup -1}) was transformed in the nonsterilized sediment (without Enterobacter hormaechei cells) as well as in the sterilized (heat-killed) sediment (with Enterobacter hormaechei cells). The results of this study suggest that the lagoon sediments at the mine site harbor Se{sup 6+}- and Se{sup 4+} -reducing bacteria and may be important sinks for soluble Se (Se{sup 6+} and Se{sup 4+}). Enterobacter hormaechei isolated from metal-contaminated sediment may have potential application in removing Se from industrial effluents.

  18. Microbial biofilms on the sandstone monuments of the Angkor Wat Complex, Cambodia.

    PubMed

    Gaylarde, Christine C; Rodríguez, César Hernández; Navarro-Noya, Yendi E; Ortega-Morales, B Otto

    2012-02-01

    Discoloring biofilms from Cambodian temples Angkor Wat, Preah Khan, and the Bayon and West Prasat in Angkor Thom contained a microbial community dominated by coccoid cyanobacteria. Molecular analysis identified Chroococcidiopsis as major colonizer, but low similarity values (<95%) suggested a similar genus or species not present in the databases. In only two of the six sites sampled were filamentous cyanobacteria, Microcoleus, Leptolyngbya, and Scytonema, found; the first two detected by sequencing of 16S rRNA gene library clones from samples of a moist green biofilm on internal walls in Preah Khan, where Lyngbya (possibly synonymous with Microcoleus) was seen by direct microscopy as major colonizer. Scytonema was detected also by microscopy on an internal wall in the Bayon. This suggests that filamentous cyanobacteria are more prevalent in internal (high moisture) areas. Heterotrophic bacteria were found in all samples. DNA sequencing of bands from DGGE gels identified Proteobacteria (Stenotrophomonas maltophilia and Methylobacterium radiotolerans) and Firmicutes (Bacillus sp., Bacillus niacini, Bacillus sporothermodurans, Lysinibacillus fusiformis, Paenibacillus sp., Paenibacillus panacisoli, and Paenibacillus zanthoxyli). Some of these bacteria produce organic acids, potentially degrading stone. Actinobacteria, mainly streptomycetes, were present in most samples; algae and fungi were rare. A dark-pigmented filamentous fungus was detected in internal and external Preah Khan samples, while the alga Trentepohlia was found only in samples taken from external, pink-stained stone at Preah Khan. Results show that these microbial biofilms are mature communities whose major constituents are resistant to dehydration and high levels of irradiation and can be involved in deterioration of sandstone. Such analyses are important prerequisites to the application of control strategies. PMID:22006074

  19. Isolation and Identification of Plant Growth Promoting Rhizobacteria from Cucumber Rhizosphere and Their Effect on Plant Growth Promotion and Disease Suppression

    PubMed Central

    Islam, Shaikhul; Akanda, Abdul M.; Prova, Ananya; Islam, Md. T.; Hossain, Md. M.

    2016-01-01

    Plant growth promoting rhizobacteria (PGPR) are the rhizosphere bacteria that may be utilized to augment plant growth and suppress plant diseases. The objectives of this study were to identify and characterize PGPR indigenous to cucumber rhizosphere in Bangladesh, and to evaluate their ability to suppress Phytophthora crown rot in cucumber. A total of 66 isolates were isolated, out of which 10 (PPB1, PPB2, PPB3, PPB4, PPB5, PPB8, PPB9, PPB10, PPB11, and PPB12) were selected based on their in vitro plant growth promoting attributes and antagonism of phytopathogens. Phylogenetic analysis of 16S rRNA sequences identified these isolates as new strains of Pseudomonas stutzeri, Bacillus subtilis, Stenotrophomonas maltophilia, and Bacillus amyloliquefaciens. The selected isolates produced high levels (26.78–51.28 μg mL-1) of indole-3-acetic acid, while significant acetylene reduction activities (1.79–4.9 μmole C2H4 mg-1 protein h-1) were observed in eight isolates. Cucumber plants grown from seeds that were treated with these PGPR strains displayed significantly higher levels of germination, seedling vigour, growth, and N content in root and shoot tissue compared to non-treated control plants. All selected isolates were able to successfully colonize the cucumber roots. Moreover, treating cucumber seeds with these isolates significantly suppressed Phytophthora crown rot caused by Phytophthora capsici, and characteristic morphological alterations in P. capsici hyphae that grew toward PGPR colonies were observed. Since these PGPR inoculants exhibited multiple traits beneficial to the host plants, they may be applied in the development of new, safe, and effective seed treatments as an alternative to chemical fungicides. PMID:26869996

  20. Microbe associated molecular patterns from rhizosphere bacteria trigger germination and Papaver somniferum metabolism under greenhouse conditions.

    PubMed

    Bonilla, A; Sarria, A L F; Algar, E; Muñoz Ledesma, F J; Ramos Solano, B; Fernandes, J B; Gutierrez Mañero, F J

    2014-01-01

    Ten PGPR from different backgrounds were assayed on Papaver somniferum var. Madrigal to evaluate their potential as biotic elicitors to increase alkaloid content under the rationale that some microbe associated molecular patterns (MAMPs) are able to trigger plant metabolism. First, the 10 strains and their culture media at two different concentrations were tested for their ability to trigger seed germination. Then, the best three strains were tested for their ability to increase seedling growth and alkaloid levels under greenhouse conditions. Only three strains and their culture media enhanced germination. Then, germination enhancing capacity of these best three strains, N5.18 Stenotrophomonas maltophilia, Aur9 Chryseobacterium balustinum and N21.4 Pseudomonas fluorescens was evaluated in soil. Finally, the three strains were applied on seedlings at two time points, by soil drench or by foliar spray. Photosynthesis was measured, plant height was recorded, capsules were weighted and alkaloids analyzed by HPLC. Only N5.18 delivered by foliar spray significantly increased plant height coupled to an increase in total alkaloids and a significant increase in opium poppy straw dry weight; these increases were supported by a better photosynthetic efficiency. The relative contents of morphine, thebaine, codeine and oripavine were affected by this treatment causing a significant increase in morphine coupled to a decrease in thebaine, demonstrating the effectivity of MAMPs from N5.18 in this plant species. Considering the increase in capsule biomass and alkaloids together with the acceleration of germination, strain N5.18 appears as a good candidate to elicit plant metabolism and consequently, to increase productivity of Papaver somniferum.

  1. Identification of a Series of Tricyclic Natural Products as Potent Broad-Spectrum Inhibitors of Metallo-β-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-β-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-β-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 μM for the Bacillus cereus II, Pseudomonas aeruginosa IMP-1, and Bacteroides fragilis CfiA metallo-β-lactamases, respectively, yet none of the compounds exhibited any inhibitory activity against the Stenotrophomonas maltophilia L-1 metallo-β-lactamase (50% inhibitory concentration > 1,000 μM). The lack of activity against angiotensin-converting enzyme and serine β-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 μg/ml). Consequently, this series of metallo-β-lactamase inhibitors exhibit the most promising antibacterial synergy activity so far observed against organisms producing metallo-β-lactamases. PMID:12019104

  2. Granulation, control of bacterial contamination, and enhanced lipid accumulation by driving nutrient starvation in coupled wastewater treatment and Chlorella regularis cultivation.

    PubMed

    Zhou, Dandan; Li, Yunbao; Yang, Yang; Wang, Yao; Zhang, Chaofan; Wang, Di

    2015-02-01

    Bacterial contamination and biomass harvesting are still challenges associated with coupling of microalgae and wastewater treatment technology. This study investigated aggregation, bacterial growth, lipid production, and pollutant removal during bacteria contaminated Chlorella regularis cultivation under nutrient starvation stress, by supposing the C/N/P ratios of the medium to 14/1.4/1 (MB₂.₅) and 44/1.4/1 (MB₄.₀), respectively. Granules of 500-650 μm were formed in the bacteria contaminated inoculum; however, purified C. regularis were generally suspended freely in the medium, indicating that bacterial presence was a prerequisite for granulation. Extracellular polymeric substance (EPS) analysis showed that polysaccharides were dominant in granules, while protein mainly distributed in the outer layer. Denaturing gradient gel electrophoresis (DGGE) results revealed Sphingobacteriales bacterium and Sphingobacterium sp. are vital organisms involved in the flocculation of microalgae, and nitrifiers (Stenotrophomonas maltophilia) could co-exist in the granular. Both EPS and DGGE results further supported that bacteria played key roles in granulation. C. regularis was always dominant and determined the total biomass concentration during co-cultivation, but bacterial growth was limited owing to nutrient deficiency. Starvation strategy also contributed to enhancement of lipid accumulation, as lipid content in MB₄.₀ with a greater C/N/P led to the greatest increase in the starvation period, and the maximum lipid productivity reached 0.057 g/(L·day). Chemical oxygen demand and nitrogen removal in MB₄.₀ reached 92 and 96%, respectively, after 3 days of cultivation. Thus, cultivation of microalgae in high C/N/P wastewater enabled simultaneous realization of biomass granulation, bacterial overgrowth limitation, enhanced lipid accumulation, and wastewater purification.

  3. Microbial Diversity in the Early In Vivo-Formed Dental Biofilm

    PubMed Central

    Heller, D.; Helmerhorst, E. J.; Gower, A. C.; Siqueira, W. L.; Paster, B. J.

    2016-01-01

    Although the mature dental biofilm composition is well studied, there is very little information on the earliest phase of in vivo tooth colonization. Progress in dental biofilm collection methodologies and techniques of large-scale microbial identification have made new studies in this field of oral biology feasible. The aim of this study was to characterize the temporal changes and diversity of the cultivable and noncultivable microbes in the early dental biofilm. Samples of early dental biofilm were collected from 11 healthy subjects at 0, 2, 4, and 6 h after removal of plaque and pellicle from tooth surfaces. With the semiquantitative Human Oral Microbiome Identification Microarray (HOMIM) technique, which is based on 16S rRNA sequence hybridizations, plaque samples were analyzed with the currently available 407 HOMIM microbial probes. This led to the identification of at least 92 species, with streptococci being the most abundant bacteria across all time points in all subjects. High-frequency detection was also made with Haemophilus parainfluenzae, Gemella haemolysans, Slackia exigua, and Rothia species. Abundance changes over time were noted for Streptococcus anginosus and Streptococcus intermedius (P = 0.02), Streptococcus mitis bv. 2 (P = 0.0002), Streptococcus oralis (P = 0.0002), Streptococcus cluster I (P = 0.003), G. haemolysans (P = 0.0005), and Stenotrophomonas maltophilia (P = 0.02). Among the currently uncultivable microbiota, eight phylotypes were detected in the early stages of biofilm formation, one belonging to the candidate bacterial division TM7, which has attracted attention due to its potential association with periodontal disease. PMID:26746720

  4. Evaluation of microorganisms cultured from injured and repressed tissue regeneration sites in endangered giant aquatic Ozark Hellbender salamanders.

    PubMed

    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

  5. Effects of Agaricus lilaceps fairy rings on soil aggregation and microbial community structure in relation to growth stimulation of western wheatgrass (Pascopyrum smithii) in Eastern Montana rangeland.

    PubMed

    Caesar-Tonthat, The Can; Espeland, Erin; Caesar, Anthony J; Sainju, Upendra M; Lartey, Robert T; Gaskin, John F

    2013-07-01

    Stimulation of plant productivity caused by Agaricus fairy rings has been reported, but little is known about the effects of these fungi on soil aggregation and the microbial community structure, particularly the communities that can bind soil particles. We studied three concentric zones of Agaricus lilaceps fairy rings in Eastern Montana that stimulate western wheatgrass (Pascopyrum smithii): outside the ring (OUT), inside the ring (IN), and stimulated zone adjacent to the fungal fruiting bodies (SZ) to determine (1) soil aggregate proportion and stability, (2) the microbial community composition and the N-acetyl-β-D-glucosaminidase activity associated with bulk soil at 0-15 cm depth, (3) the predominant culturable bacterial communities that can bind to soil adhering to wheatgrass roots, and (4) the stimulation of wheatgrass production. In bulk soil, macroaggregates (4.75-2.00 and 2.00-0.25 mm) and aggregate stability increased in SZ compared to IN and OUT. The high ratio of fungal to bacteria (fatty acid methyl ester) and N-acetyl-β-D-glucosaminidase activity in SZ compared to IN and OUT suggest high fungal biomass. A soil sedimentation assay performed on the predominant isolates from root-adhering soil indicated more soil-binding bacteria in SZ than IN and OUT; Pseudomonas fluorescens and Stenotrophomonas maltophilia isolates predominated in SZ, whereas Bacillus spp. isolates predominated in IN and OUT. This study suggests that growth stimulation of wheatgrass in A. lilaceps fairy rings may be attributed to the activity of the fungus by enhancing soil aggregation of bulk soil at 0-15 cm depth and influencing the amount and functionality of specific predominant microbial communities in the wheatgrass root-adhering soil.

  6. ['In vitro' activity of different antimicrobial agents on Gram-negative nonfermentative bacilli, excluding Pseudomonas aeruginosa and Acinetobacter spp].

    PubMed

    Vay, C A; Almuzara, M N; Rodríguez, C H; Pugliese, M L; Lorenzo Barba, F; Mattera, J C; Famiglietti, A M R

    2005-01-01

    Gram-negative nonfermentative bacilli (NFB) are widely spread in the environment. Besides of difficulties for identification, they often have a marked multiresistance to antimicrobial agents, including those active against Pseudomonas aeruginosa. The objective of this study was to evaluate the 'in vitro' activity of different antimicrobial agents on 177 gram-negative nonfermentative bacilli isolates (excluding Pseudomonas aeruginosa and Acinetobacter spp.) isolated from clinical specimens. Minimum inhibitory concentrations (MIC) were determined according to the Mueller Hinton agar dilution method against the following antibacterial agents: ampicillin, piperacillin, piperacillin-tazobactam, sulbactam, cefoperazone, cefoperazone-sulbactam, ceftazidime, cefepime, aztreonam, imipenem, meropenem, colistin, gentamicin, amikacin, trimethoprim-sulfamethoxazole, chloramphenicol, erythromycin, rifampin, norfloxacin, ciprofloxacin and minocycline. Seven isolates: Sphingobacterium multivorum (2), Sphingobacteriumspiritivorum (1), Empedobacterbrevis (1), Weeksella virosa (1), Bergeyella zoohelcum (1) and Oligella urethralis (1), were tested for amoxicillin-clavulanic acid and ampicillin-sulbactam susceptibility, and susceptibility to cefoperazone or sulbactam was not determined. Multiresistance was generally found in Stenotrophomonas maltophilia, Burkholderia cepacia, Chryseobacterium spp., Myroides spp., Achromobacter xylosoxidans, and Ochrobactrum anthropi isolates. On the other hand, Pseudomonas stutzeri, Shewanella putrefaciens-algae, Sphingomonas paucimobilis, and Pseudomonas oryzihabitans, Bergeyella zoohelcum, Weeksella virosa and Oligella urethralis were widely susceptible to the antibacterial agents tested. As a result of the wide variation in antimicrobial susceptibility shown by different species, a test on susceptibility to different antibacterial agents is essential in order to select an adequate therapy. The marked multiresistance evidenced by some species

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

    PubMed

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

    2013-01-01

    North Sinai deserts were surveyed for the predominant plant cover and for the culturable bacteria nesting their roots and shoots. Among 43 plant species reported, 13 are perennial (e.g. Fagonia spp., Pancratium spp.) and 30 annuals (e.g. Bromus spp., Erodium spp.). Eleven species possessed rhizo-sheath, e.g. Cyperus capitatus, Panicum turgidum and Trisetaria koelerioides. Microbiological analyses demonstrated: the great diversity and richness of associated culturable bacteria, in particular nitrogen-fixing bacteria (diazotrophs); the majority of bacterial residents were of true and/or putative diazotrophic nature; the bacterial populations followed an increasing density gradient towards the root surfaces; sizeable populations were able to reside inside the root (endorhizosphere) and shoot (endophyllosphere) tissues. Three hundred bacterial isolates were secured from studied spheres. The majority of nitrogen-fixing bacilli isolates belonged to Bacillus megaterium, Bacillus pumilus, Bacillus polymexa, Bacillus macerans, Bacillus circulans and Bacillus licheniformis. The family Enterobacteriaceae represented by Enterobacter agglomerans, Enterobacter sackazakii, Enterobacter cloacae, Serratia adorifera, Serratia liquefaciens and Klebsiella oxytoca. The non-Enterobacteriaceae population was rich in Pantoae spp., Agrobacterium rdiobacter, Pseudomonas vesicularis, Pseudomonas putida, Stenotrophomonas maltophilia, Ochrobactrum anthropi, Sphingomonas paucimobilis and Chrysemonas luteola. Gluconacetobacter diazotrophicus were reported inside root and shoot tissues of a number of tested plants. The dense bacterial populations reported speak well to the very possible significant role played by the endophytic bacterial populations in the survival, in respect of nutrition and health, of existing plants. Such groups of diazotrophs are good candidates, as bio-preparates, to support the growth of future field crops grown in deserts of north Sinai and irrigated by the water of El

  8. Effects of Agaricus lilaceps fairy rings on soil aggregation and microbial community structure in relation to growth stimulation of western wheatgrass (Pascopyrum smithii) in Eastern Montana rangeland.

    PubMed

    Caesar-Tonthat, The Can; Espeland, Erin; Caesar, Anthony J; Sainju, Upendra M; Lartey, Robert T; Gaskin, John F

    2013-07-01

    Stimulation of plant productivity caused by Agaricus fairy rings has been reported, but little is known about the effects of these fungi on soil aggregation and the microbial community structure, particularly the communities that can bind soil particles. We studied three concentric zones of Agaricus lilaceps fairy rings in Eastern Montana that stimulate western wheatgrass (Pascopyrum smithii): outside the ring (OUT), inside the ring (IN), and stimulated zone adjacent to the fungal fruiting bodies (SZ) to determine (1) soil aggregate proportion and stability, (2) the microbial community composition and the N-acetyl-β-D-glucosaminidase activity associated with bulk soil at 0-15 cm depth, (3) the predominant culturable bacterial communities that can bind to soil adhering to wheatgrass roots, and (4) the stimulation of wheatgrass production. In bulk soil, macroaggregates (4.75-2.00 and 2.00-0.25 mm) and aggregate stability increased in SZ compared to IN and OUT. The high ratio of fungal to bacteria (fatty acid methyl ester) and N-acetyl-β-D-glucosaminidase activity in SZ compared to IN and OUT suggest high fungal biomass. A soil sedimentation assay performed on the predominant isolates from root-adhering soil indicated more soil-binding bacteria in SZ than IN and OUT; Pseudomonas fluorescens and Stenotrophomonas maltophilia isolates predominated in SZ, whereas Bacillus spp. isolates predominated in IN and OUT. This study suggests that growth stimulation of wheatgrass in A. lilaceps fairy rings may be attributed to the activity of the fungus by enhancing soil aggregation of bulk soil at 0-15 cm depth and influencing the amount and functionality of specific predominant microbial communities in the wheatgrass root-adhering soil. PMID:23455430

  9. Evaluation of microorganisms cultured from injured and repressed tissue regeneration sites in endangered giant aquatic Ozark Hellbender salamanders.

    PubMed

    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

  10. Antibacterial Activity of Blue Light against Nosocomial Wound Pathogens Growing Planktonically and as Mature Biofilms

    PubMed Central

    Thwaite, Joanne E.; Burt, Rebecca; Laws, Thomas R.; Raguse, Marina; Moeller, Ralf; Webber, Mark A.; Oppenheim, Beryl A.

    2016-01-01

    ABSTRACT The blue wavelengths within the visible light spectrum are intrinisically antimicrobial and can photodynamically inactivate the cells of a wide spectrum of bacteria (Gram positive and negative) and fungi. Furthermore, blue light is equally effective against both drug-sensitive and -resistant members of target species and is less detrimental to mammalian cells than is UV radiation. Blue light is currently used for treating acnes vulgaris and Helicobacter pylori infections; the utility for decontamination and treatment of wound infections is in its infancy. Furthermore, limited studies have been performed on bacterial biofilms, the key growth mode of bacteria involved in clinical infections. Here we report the findings of a multicenter in vitro study performed to assess the antimicrobial activity of 400-nm blue light against bacteria in both planktonic and biofilm growth modes. Blue light was tested against a panel of 34 bacterial isolates (clinical and type strains) comprising Acinetobacter baumannii, Enterobacter cloacae, Stenotrophomonas maltophilia, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Enterococcus faecium, Klebsiella pneumoniae, and Elizabethkingia meningoseptica. All planktonic-phase bacteria were susceptible to blue light treatment, with the majority (71%) demonstrating a ≥5-log10 decrease in viability after 15 to 30 min of exposure (54 J/cm2 to 108 J/cm2). Bacterial biofilms were also highly susceptible to blue light, with significant reduction in seeding observed for all isolates at all levels of exposure. These results warrant further investigation of blue light as a novel decontamination strategy for the nosocomial environment, as well as additional wider decontamination applications. IMPORTANCE Blue light shows great promise as a novel decontamination strategy for the nosocomial environment, as well as additional wider decontamination applications (e.g., wound closure during surgery). This warrants further

  11. Prevalent bacterial species and novel phylotypes in advanced noma lesions.

    PubMed

    Paster, B J; Falkler Jr, W A; Enwonwu, C O; Idigbe, E O; Savage, K O; Levanos, V A; Tamer, M A; Ericson, R L; Lau, C N; Dewhirst, F E

    2002-06-01

    The purpose of this study was to determine the bacterial diversity in advanced noma lesions using culture-independent molecular methods. 16S ribosomal DNA bacterial genes from DNA isolated from advanced noma lesions of four Nigerian children were PCR amplified with universally conserved primers and spirochetal selective primers and cloned into Escherichia coli. Partial 16S rRNA sequences of approximately 500 bases from 212 cloned inserts were used initially to determine species identity or closest relatives by comparison with sequences of known species or phylotypes. Nearly complete sequences of approximately 1,500 bases were obtained for most of the potentially novel species. A total of 67 bacterial species or phylotypes were detected, 25 of which have not yet been grown in vitro. Nineteen of the species or phylotypes, including Propionibacterium acnes, Staphylococcus spp., and the opportunistic pathogens Stenotrophomonas maltophilia and Ochrobactrum anthropi were detected in more than one subject. Other known species that were detected included Achromobacter spp., Afipia spp., Brevundimonas diminuta, Capnocytophaga spp., Cardiobacterium sp., Eikenella corrodens, Fusobacterium spp., Gemella haemoylsans, and Neisseria spp. Phylotypes that were unique to noma infections included those in the genera Eubacterium, Flavobacterium, Kocuria, Microbacterium, and Porphyromonas and the related Streptococcus salivarius and genera Sphingomonas and TREPONEMA: Since advanced noma lesions are infections open to the environment, it was not surprising to detect species not commonly associated with the oral cavity, e.g., from soil. Several species previously implicated as putative pathogens of noma, such as spirochetes and Fusobacterium spp., were detected in at least one subject. However, due to the limited number of available noma subjects, it was not possible at this time to associate specific species with the disease.

  12. Cationic compounds with activity against multidrug-resistant bacteria: interest of a new compound compared with two older antiseptics, hexamidine and chlorhexidine.

    PubMed

    Grare, M; Dibama, H Massimba; Lafosse, S; Ribon, A; Mourer, M; Regnouf-de-Vains, J-B; Finance, C; Duval, R E

    2010-05-01

    Use of antiseptics and disinfectants is essential in infection control practices in hospital and other healthcare settings. In this study, the in vitro activity of a new promising compound, para-guanidinoethylcalix[4]arene (Cx1), has been evaluated in comparison with hexamidine (HX) and chlorhexidine (CHX), two older cationic antiseptics. The MICs for 69 clinical isolates comprising methicillin-resistant Staphylococcus aureus, methicillin-sensitive S. aureus, coagulase-negative staphylococci (CoNS) (with or without mecA), vancomycin-resistant enterococci, Enterobacteriaceae producing various beta-lactamases and non-fermenting bacilli (Pseudomonas aeruginosa, Acinetobacter baumanii, Stenotrophomonas maltophilia) were determined. Cx1 showed similar activity against S. aureus, CoNS and Enterococcus spp., irrespective of the presence of mecA or van genes, or associated resistance genes, with very good activity against CoNS (MIC <1 mg/L). Variable activities were observed against Enterobacteriaceae; the MICs determined seemed to be dependent both on the genus (MICs of 2, 8 and 64 mg/L for Escherichia coli, Klebsiella pneumoniae and Yersinia enterocolitica, respectively) and on the resistance phenotype production of [Extended Spectrum beta-Lactase (ESBLs) or other beta-lactamases; overproduction of AmpC]. Poor activity was found against non-fermenting bacilli, irrespective of the resistance phenotype. CHX appeared to be the most active compound against all strains, with broad-spectrum and conserved activity against multidrug-resistant strains. HX showed a lower activity, essentially against Gram-positive strains. Consequently, the differences observed with respect to Cx1 suggest that they are certainly not the consequence of antibiotic resistance phenotypes, but rather the result of membrane composition modifications (e.g. of lipopolysaccharide), or of the presence of (activated) efflux-pumps. These results raise the possibility that Cx1 may be a potent new antibacterial

  13. Microbial biofilms on the sandstone monuments of the Angkor Wat Complex, Cambodia.

    PubMed

    Gaylarde, Christine C; Rodríguez, César Hernández; Navarro-Noya, Yendi E; Ortega-Morales, B Otto

    2012-02-01

    Discoloring biofilms from Cambodian temples Angkor Wat, Preah Khan, and the Bayon and West Prasat in Angkor Thom contained a microbial community dominated by coccoid cyanobacteria. Molecular analysis identified Chroococcidiopsis as major colonizer, but low similarity values (<95%) suggested a similar genus or species not present in the databases. In only two of the six sites sampled were filamentous cyanobacteria, Microcoleus, Leptolyngbya, and Scytonema, found; the first two detected by sequencing of 16S rRNA gene library clones from samples of a moist green biofilm on internal walls in Preah Khan, where Lyngbya (possibly synonymous with Microcoleus) was seen by direct microscopy as major colonizer. Scytonema was detected also by microscopy on an internal wall in the Bayon. This suggests that filamentous cyanobacteria are more prevalent in internal (high moisture) areas. Heterotrophic bacteria were found in all samples. DNA sequencing of bands from DGGE gels identified Proteobacteria (Stenotrophomonas maltophilia and Methylobacterium radiotolerans) and Firmicutes (Bacillus sp., Bacillus niacini, Bacillus sporothermodurans, Lysinibacillus fusiformis, Paenibacillus sp., Paenibacillus panacisoli, and Paenibacillus zanthoxyli). Some of these bacteria produce organic acids, potentially degrading stone. Actinobacteria, mainly streptomycetes, were present in most samples; algae and fungi were rare. A dark-pigmented filamentous fungus was detected in internal and external Preah Khan samples, while the alga Trentepohlia was found only in samples taken from external, pink-stained stone at Preah Khan. Results show that these microbial biofilms are mature communities whose major constituents are resistant to dehydration and high levels of irradiation and can be involved in deterioration of sandstone. Such analyses are important prerequisites to the application of control strategies.

  14. Inhibition of metallo-beta-lactamases by a series of mercaptoacetic acid thiol ester derivatives.

    PubMed Central

    Payne, D J; Bateson, J H; Gasson, B C; Proctor, D; Khushi, T; Farmer, T H; Tolson, D A; Bell, D; Skett, P W; Marshall, A C; Reid, R; Ghosez, L; Combret, Y; Marchand-Brynaert, J

    1997-01-01

    A series of mercaptoacetic acid thiol esters have been identified as metallo-beta-lactamase inhibitors. Electrospray mass spectrometry (ESMS) has shown that irreversible inhibition of the Bacillus cereus II metallo-beta-lactamase by SB214751, SB214752, and SB213079 was concomitant with a 90-Da increase in mass of the enzyme. Tryptic digestion of the B. cereus II inhibited with SB214751 illustrated that the peptide fragment, containing the only cysteine of the enzyme, had undergone a mass increment of 90 Da. It was further demonstrated that B. cereus II hydrolyzed this type of compound across the thiol ester bond to yield mercaptoacetic acid. Mercaptoacetic acid is the only molecular fragment common to SB214751, SB214752, and SB213079, and free mercaptoacetic acid does not bind covalently to B. cereus II. Therefore, it is concluded that these compounds inhibit B. cereus II by the mechanism-based delivery of mercaptoacetic acid, forming a disulfide linkage with the active sites cysteine (predicted mass shift = +90 Da) under the aerobic conditions of the assay. The different thiol esters examined had a broad range of potencies against the metallo-beta-lactamases tested. For example SB214751, SB214752, and SB213079 all had 50% inhibitory concentrations of < 10 and > 1,000 microM for the Stenotrophomonas maltophilia L-1 and Bacteroides fragilis CfiA enzymes, respectively. SB216968 was particularly active against the Aeromonas hydrophila CphA metallo-beta-lactamase and was found to be an uncompetitive inhibitor of this enzyme (Ki = 3.9 microM), whereas it exhibited irreversible inhibition of the L-1 enzyme. These observations with this series of compounds have revealed subtle differences between the active sites of different metallo-beta-lactamases. Finally, a novel application for isothermal titration calorimetry for assessing the zinc chelating activity of candidate inhibitors is also presented. PMID:8980769

  15. [Isolation and characterization of two bacteria with heavy metal resistance and phosphate solubilizing capability].

    PubMed

    Tian, Jiang; Peng, Xia-Wei; Li, Xia; Sun, Ya-Jun; Feng, Hong-Mei; Jiang, Ze-Ping

    2014-06-01

    Two phosphate solubilizing bacteria (T PSB1 and T PSB 2) with high heavy metal resistance were isolated from soil of a lead-zinc mine in Huayuan of Hunan Province, China. These two bacteria were identified as Stenotrophomonas maltophilia and Burkholderia gladioli by 16S rRNA sequencing analysis, respectively. In the media containing insoluble inorganic calcium phosphate, the soluble phosphate amounts reached respectively 402.9 mg x L(-1) and 589.9 mg x L(-1) with the bacteria T PSB1 and T PSB2 after two weeks' growth. Moreover, the two bacteria developed solubilizing halos on the plates supplemented with the organic phosphate compounds, and the resulting soluble phosphate amounts in the broth media were respectively 2.97 mg x L(-1) and 4.69 mg x L(-1). In addition, these two bacteria showed the resistance to up to 2000 mg x L(-1) Zn2+, and their phosphate solubilizing amounts reached respectively 114.8 mg x L(-1) and 125.1 mg x L(-1). Similarly, their heavy metal resistance and phosphate solubilizing ability were also found in the Cr and Pb broth media with the concentration of 1000 mg x L(-1). In the Pb media, the soluble phosphate amounts reached respectively 57.9 mg x L(-1) and 71.7 mg x L(-1), and the soluble P amounts in the Cr media were 60.1 mg x L(-1) and 98.4 mg x L(-1) at the concentration of 1000 mg x L(-1).

  16. Antibacterial Activity of Salvadora persica L. (Miswak) Extracts against Multidrug Resistant Bacterial Clinical Isolates.

    PubMed

    Al-Ayed, Mohamed Saeed Zayed; Asaad, Ahmed Morad; Qureshi, Mohamed Ansar; Attia, Hany Goda; AlMarrani, Abduljabbar Hadi

    2016-01-01

    Much effort has focused on examining the inhibitory effect of Salvadora persica (miswak) on oral microorganisms, but information concerning its antibacterial activity against other human pathogens, particularly multidrug resistant (MDR) isolates, is scarce. Therefore, this study aimed to assess the in vitro antibacterial activities of Salvadora persica L. extracts against 10 MDR bacterial clinical isolates other than oral pathogens. The antibacterial activity of aqueous and methanol miswak extracts was assessed using the agar dilution and minimum inhibitory concentration (MIC) methods. Overall, the 400 mg/mL of miswak extract was the most effective on all strains. The methanol extract exhibited a stronger antibacterial activity against Gram-negative (3.3-13.6 mm) than Gram-positive (1.8-8.3 mm) bacteria. The lowest MIC value was seen for E. coli (0.39, 1.56 µg/mL), followed by Streptococcus pyogenes (1.56 µg/mL). The highest MIC value (6.25, 12.5 µg/mL) was recorded for methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumannii, and Stenotrophomonas maltophilia. This study demonstrates, for the first time, the moderate to strong antibacterial activity of miswak extracts against all tested MDR-pathogens. Methanol extract appears to be a potent antimicrobial agent that could be considered as complementary and alternative medicine against resistant pathogens. Further studies on a large number of MDR organisms are necessary to investigate and standardize the inhibitory effect of miswak extracts against these emerging pathogens. PMID:26904146

  17. 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

  18. Carbazole angular dioxygenation and mineralization by bacteria isolated from hydrocarbon-contaminated tropical African soil.

    PubMed

    Salam, L B; Ilori, M O; Amund, O O; Numata, M; Horisaki, T; Nojiri, H

    2014-01-01

    Four bacterial strains isolated from hydrocarbon-contaminated soils in Lagos, Nigeria, displayed extensive degradation abilities on carbazole, an N-heterocyclic aromatic hydrocarbon. Physicochemical analyses of the sampling sites (ACPP, MWO, NESU) indicate gross pollution of the soils with a high hydrocarbon content (157,067.9 mg/kg) and presence of heavy metals. Phylogenetic analysis of the four strains indicated that they were identified as Achromobacter sp. strain SL1, Pseudomonas sp. strain SL4, Microbacterium esteraromaticum strain SL6, and Stenotrophomonas maltophilia strain BA. The rates of degradation of carbazole by the four isolates during 30 days of incubation were 0.057, 0.062, 0.036, and 0.050 mg L(-1) h(-1) for strains SL1, SL4, SL6, and BA. Gas chromatographic (GC) analyses of residual carbazole after 30 days of incubation revealed that 81.3, 85, 64.4, and 76 % of 50 mg l(-1) carbazole were degraded by strains SL1, SL4, SL6, and BA, respectively. GC-mass spectrometry and high-performance liquid chromatographic analyses of the extracts from the growing and resting cells of strains SL1, SL4, and SL6 cultured on carbazole showed detection of anthranilic acid and catechol while these metabolites were not detected in strain BA under the same conditions. This study has established for the first time carbazole angular dioxygenation and mineralization by isolates from African environment.

  19. [New aspects of antibiotic resistance and possibilities of its prevention].

    PubMed

    Blahová, J; Králiková, K; Krcméry, V

    2001-08-01

    New phenomena of the antibiotic resistance in bacteria have recently appeared. The may hold present explosive development of resistance and prevent its transferability from multiple drug resistant bacteria to still sensitive ones. They may prevent the production of so-called extended-spectrum beta-lactamases (ESBLs) among Enterobacteriaceae producing resistance virtually to all penicillins and cephalosporins with exception of those antibiotics potentiated by clavulanic acid or sulbactam, the resistance to vancomycin in enterococci and staphylococce, and the resistance of Stenotrophomonas maltophilia. Factors participating on the development of resistance include: a) transferability of resistance genes among bacteria which explosively change susceptible strains to resistant ones, b) dosage and types of antibiotics which cause the selection pressure to certain species of bacteria, c) level of organization and strict adherence to hygienic and anti-epidemic regimen starting with the entry of patients into the hospital. Analyses are necessary to check whether the patient brings resistant bacteria with a transferable resistance (with ESBLs) into the hospital. Preventive measures would be strictly applied to stop the clonal spread of resistant strains among the patients and/or hospital environment, which occurs if these strains have such opportunity. Last, but not least to be considered is the dosage, composition and rationality of administration of antibacterials, mainly in post-operative prophylaxis in intensive care units, in so-called empirical usage, etc. At the same time, it would be highly unethical to hesitate with application of antibacterials to patients when it is justified, necessary and rational. Hospital antibiotics policy should rationally decide between these alternatives in each application of antibiotics or their combinations.

  20. Production of vanillin from waste residue of rice bran oil by Aspergillus niger and Pycnoporus cinnabarinus.

    PubMed

    Zheng, Lirong; Zheng, Pu; Sun, Zhihao; Bai, Yanbing; Wang, Jun; Guo, Xinfu

    2007-03-01

    A new technology of transforming ferulic acid, which was from waste residue of rice bran oil, into vanillin was developed by a combination of fungal strains Aspergillus niger CGMCC0774 and Pycnoporus cinnabarinus CGMCC1115. Various concentrations of ferulic acid were compared, and the highest yield reached 2.2 g l(-1) of vanillic acid by A. niger CGMCC0774 in a 25 l fermenter when concentration of ferulic acid was 4 g l(-1). The filtrate of A. niger CGMCC0774 culture was concentrated and vanillic acid in the filtrate was bio-converted into vanillin by P. cinnabarinus CGMCC1115. The yield of vanillin reached 2.8 g l(-1) when 5 g l(-1) of glucose and 25 g of HZ802 resin were supplemented in the bioconversion medium. The 13C isotope analysis indicated that delta13C(PDB) of vanillin prepared was much different from chemically synthesized vanillin. PMID:16782330

  1. 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

  2. BSAC standardized disc susceptibility testing method (version 8).

    PubMed

    Andrews, J M

    2009-09-01

    There have been considerable changes to the format of the recommendations since the previous version (version 7). The majority of the footnotes to the tables have been removed and the notations added to the end column; it is hoped that this change will avoid confusion in interpretation. Antibiotics have been separated into groups, e.g. beta-lactams, aminoglycosides, etc. Recommendations for urinary tract infections (UTIs) have been removed for most agents except for those that are administered solely for the treatment of uncomplicated UTIs or where there are limited recommendations for specific organisms, e.g. trimethoprim. For agents that previously had dual recommendations, systemic recommendations remain and the intermediate category can be used for interpretation for UTIs because intermediate susceptibility infers that the infection may respond as the agent is concentrated at the site of infection. This change will also avoid errors in interpretation when an organism is isolated from multiple sites, e.g. blood and urine. The changes that have been made to version 7 are as follows: MIC and zone diameter breakpoints (BPs) for trimethoprim, fosfomycin and nitrofurantoin for UTIs (Table 7); MIC and zone diameter breakpoints (BPs) for doripenem (Tables 7-9); colistin MIC BPs for Pseudomonas spp. (Table 9), co-trimoxazole MIC BPs for Stenotrophomonas maltophilia (Table 10); staphylococci MIC and zone diameter BPs for clarithromycin, clindamycin, erythromycin, quinupristin/dalfopristin, trimethoprim UTI, nitrofurantoin UTI and rifampicin (Table 11); Streptococcus pneumoniae MIC and zone diameter BPs for azithromycin, clarithromycin, erythromycin, co-trimoxazole, linezolid, rifampicin and telithromycin (Table 12); addition of streptomycin recommendations for enterococci (Table 13); enterococcal MIC and zone diameter BPs for quinupristin/dalfopristin, nitrofurantoin UTI and trimethoprim UTI (Table 13); beta-haemolytic streptococci MIC and zone diameter BPs for

  3. BSAC standardized disc susceptibility testing method (version 7).

    PubMed

    Andrews, J M

    2008-08-01

    The changes that have been made to the previous version of the recommendations (version 6) are as follows: medium and incubation condition for testing Acinetobacter spp. (Tables 1 and 6); use of cefoxitin as an indicator antibiotic for detecting methicillin/oxacillin/cefoxitin resistance in coagulase-negative staphylococci (Tables 1, 6 and 11); MIC breakpoint for co-trimoxazole based on the trimethoprim concentration in a 1:19 combination with sulfamethoxazole (Tables 7, 10, 11, 12, 15, 16 and 19); advice on the use of azithromycin for the treatment of infections with Salmonella typhi (footnote to Table 7); amendment to the recommendation for cefuroxime for the treatment of infections with Proteus mirabilis (footnote Table 7); MIC and zone diameter breakpoints for Stenotrophomonas maltophilia only (Table 10); MIC breakpoints for daptomycin (Tables 11 and 15); clarification for staphylococci that the neomycin zone diameter breakpoints are for topical use only and differentiate the isolates outside the 'wild-type' population in Table 11; clarification for beta-haemolytic streptococci that the linezolid zone diameter breakpoints relate to an MIC breakpoint of 2 mg/L as no data for the intermediate category are currently available (Table 15); clarification that strains with reduced susceptibility to fluoroquinolones give no zone of inhibition with a 30 microg nalidixic acid disc (Tables 16 and 21); erythromycin is no longer used for therapy of Neisseria gonorrhoeae, but may be tested for epidemiological purposes (Table 17); clarification that the ciprofloxacin zone diameter breakpoint for Neisseria meningitidis relates to the MIC breakpoint of 0.03 mg/L as no data for the intermediate category are currently available; clarification that the ciprofloxacin zone diameter breakpoints for Campylobacter spp. relate to an MIC breakpoint of 0.5 mg/L as no data for the intermediate category are currently available; clarification that for ciprofloxacin and vancomycin zone

  4. 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

    ., 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.

  5. 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

  6. Exposure to airborne microorganisms, dust and endotoxin during processing of valerian roots on farms.

    PubMed

    Skórska, Czesława; Sitkowska, Jolanta; Krysińska-Traczyk, Ewa; Cholewa, Grazyna; Dutkiewicz, Jacek

    2005-01-01

    The aim of this study was to determine the levels of microorganisms, dust and endotoxin in the air during various stages of valerian (Valeriana officinalis) roots processing by herb farmers and to examine the species composition of airborne microflora. Air samples were collected on glass fibre filters by use of personal samplers on 15 farms owned by valerian cultivating farmers, located in Lublin province (eastern Poland). The concentrations of total viable microorganisms (bacteria + fungi) in the air showed a marked variability and were within a range of 0.95-7,966.6 x 10(3) cfu/m (3). Though median was relatively low (10.75 x 10(3) cfu/m (3)), on 4 farms the concentrations exceeded the level of 10(5) cfu/m (3) and on 1 farm the level of 10(6) cfu/m (3). During the processing of valerian roots, distinct changes could be observed in the composition of airborne microflora. In the first stages of processing, the freshly dug and washed roots until shaking in the drying room, the most numerous were Gram-negative bacteria of the family Pseudomonadaceae (mostly Stenotrophomonas maltophilia, Pseudomonas chlororaphis and Pseudomonas fluorescens). After drying, the dominant organisms were thermo-resistant endospore-forming bacilli (Bacillus spp.) and fungi, among which prevailed Aspergillus fumigatus. Altogether, 29 species or genera of bacteria and 19 species or genera of fungi were identified in the farm air during valerian processing, of these, 10 and 12 species or genera respectively were reported as having allergenic and/or immunotoxic properties. The concentrations of airborne dust and endotoxin on the examined farms were very large and ranged from 10.0-776.7 mg/m (3), and from 0.15-24,448.2 microg/m (3), respectively (medians 198.3 mg/m (3) and 40.48 microg/m (3)). In conclusion, farmers cultivating valerian could be exposed during processing of valerian roots to large concentrations of airborne microorganisms, dust and endotoxin posing a risk of work

  7. Trends in the Susceptibility of Clinically Important Resistant Bacteria to Tigecycline: Results from the Tigecycline In Vitro Surveillance in Taiwan Study, 2006 to 2010

    PubMed Central

    Chen, Yen-Hsu; Lu, Po-Liang; Huang, Cheng-Hua; Liao, Chun-Hsing; Lu, Chin-Te; Chuang, Yin-Ching; Tsao, Shih-Ming; Chen, Yao-Shen; Liu, Yung-Ching; Chen, Wei-Yu; Jang, Tsrang-Neng; Lin, Hsiu-Chen; Chen, Chih-Ming; Shi, Zhi-Yuan; Pan, Sung-Ching; Yang, Jia-Ling; Kung, Hsiang-Chi; Liu, Chun-Eng; Cheng, Yu-Jen; Liu, Jien-Wei; Sun, Wu; Wang, Lih-Shinn; Ko, Wen-Chien; Yu, Kwok-Woon; Chiang, Ping-Cherng; Lee, Ming-Hsun; Lee, Chun-Ming; Hsu, Gwo-Jong

    2012-01-01

    The Tigecycline In Vitro Surveillance in Taiwan (TIST) study, a nationwide, prospective surveillance during 2006 to 2010, collected a total of 7,793 clinical isolates, including methicillin-resistant Staphylococcus aureus (MRSA) (n = 1,834), penicillin-resistant Streptococcus pneumoniae (PRSP) (n = 423), vancomycin-resistant enterococci (VRE) (n = 219), extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (n = 1,141), ESBL-producing Klebsiella pneumoniae (n = 1,330), Acinetobacter baumannii (n = 1,645), and Stenotrophomonas maltophilia (n = 903), from different specimens from 20 different hospitals in Taiwan. MICs of tigecycline were determined following the criteria of the U.S. Food and Drug Administration (FDA) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST-2011). Among drug-resistant Gram-positive pathogens, all of the PRSP isolates were susceptible to tigecycline (MIC90, 0.03 μg/ml), and only one MRSA isolate (MIC90, 0.5 μg/ml) and three VRE isolates (MIC90, 0.125 μg/ml) were nonsusceptible to tigecycline. Among the Gram-negative bacteria, the tigecycline susceptibility rates were 99.65% for ESBL-producing E. coli (MIC90, 0.5 μg/ml) and 96.32% for ESBL-producing K. pneumoniae (MIC90, 2 μg/ml) when interpreted by FDA criteria but were 98.7% and 85.8%, respectively, when interpreted by EUCAST-2011 criteria. The susceptibility rate for A. baumannii (MIC90, 4 μg/ml) decreased from 80.9% in 2006 to 55.3% in 2009 but increased to 73.4% in 2010. A bimodal MIC distribution was found among carbapenem-susceptible A. baumannii isolates, and a unimodal MIC distribution was found among carbapenem-nonsusceptible A. baumannii isolates. In Taiwan, tigecycline continues to have excellent in vitro activity against several major clinically important drug-resistant bacteria, with the exception of A. baumannii. PMID:22203598

  8. 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

  9. Prevalence of Resistant Gram-Negative Bacilli in Bloodstream Infection in Febrile Neutropenia Patients Undergoing Hematopoietic Stem Cell Transplantation

    PubMed Central

    Wang, Ling; Wang, Ying; Fan, Xing; Tang, Wei; Hu, Jiong

    2015-01-01

    Abstract 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

  10. Bulgecin A as a β-lactam enhancer for carbapenem-resistant Pseudomonas aeruginosa and carbapenem-resistant Acinetobacter baumannii clinical isolates containing various resistance mechanisms

    PubMed Central

    Skalweit, Marion J; Li, Mei

    2016-01-01

    Genetic screening of Pseudomonas aeruginosa (PSDA) and Acinetobacter baumannii (ACB) reveals genes that confer increased susceptibility to β-lactams when disrupted, suggesting novel drug targets. One such target is lytic transglycosylase. Bulgecin A (BlgA) is a natural product of Pseudomonas mesoacidophila and a lytic transglycosolase inhibitor that works synergistically with β-lactams targeting PBP3 for Enterobacteriaceae. BlgA also weakly inhibits di-Zn2+ metallo-β-lactamases like L1 of Stenotrophomonas maltophilia. We hypothesized that because of its unique mechanism of action, BlgA could restore susceptibility to carbapenems in carbapenem-resistant PSDA (CR-PSDA) and carbapenem-resistant ACB, as well as ACB resistant to sulbactam. A BlgA-containing extract was prepared using a previously published protocol. CR-PSDA clinical isolates demonstrating a variety of carbapenem resistance mechanisms (VIM-2 carbapenemases, efflux mechanisms, and AmpC producer expression) were characterized with agar dilution minimum inhibitory concentration (MIC) testing and polymerase chain reaction. Growth curves using these strains were prepared using meropenem, BlgA extract, and meropenem plus BlgA extract. A concentrated Blg A extract combined with low concentrations of meropenem, was able to inhibit the growth of clinical strains of CR-PSDA for strains that had meropenem MICs ≥8 mg/L by agar dilution, and a clinical strain of an OXA-24 producing ACB that had a meropenem MIC >32 mg/L and intermediate ampicillin/sulbactam susceptibility. Similar experiments were conducted on a TEM-1 producing ACB strain resistant to sulbactam. BlgA with ampicillin/sulbactam inhibited the growth of this organism. As in Enterobacteriaceae, BlgA appears to restore the efficacy of meropenem in suppressing the growth of CR-PSDA and carbapenem-resistant ACB strains with a variety of common carbapenem resistance mechanisms. BlgA extract also inhibits VIM-2 β-lactamase in vitro. BlgA may prove to be

  11. The antimicrobial efficacy of silver on antibiotic-resistant bacteria isolated from burn wounds.

    PubMed

    Percival, Steven L; Thomas, John; Linton, Sara; Okel, Tyler; Corum, Linda; Slone, Will

    2012-10-01

    The antibiotic-resistant bacteria are a major concern to wound care because of their ability to resist many of the antibiotics used today to treat infections. Consequently, other antimicrobials, in particular ionic silver, are considered ideal topical agents for effectively helping to manage and prevent local infections. Little is known about the antimicrobial efficacy of ionic silver on antibiotic-resistant bacteria at different pH values. Consequently, in this study our aim was to evaluate the effect of pH on the antimicrobial efficacy of a silver alginate (SA) and a silver carboxymethyl cellulose (SCMC) dressing on antibiotic-resistant bacteria isolated from burn patients. Forty-nine antibiotic-resistant bacteria, including Vancomycin-resistant Enterococcus faecium, meticillin-resistant Staphylococcus aureus, multidrug-resistant (MDR) Pseudomonas aeruginosa, MDR Vibrio sp, MDR Stenotrophomonas maltophilia, extended-spectrum ß-lactamase (ESBL) producing Salmonella sp, ESBL producing Klebsiella pneumoniae, ESBL producing Proteus mirabilis, ESBL producing Escherichia coli and MDR Acinetobacter baumannii, routinely isolated from burn wounds were used in the study and evaluated for their susceptibility to two silver containing wound dressings using a standardised antimicrobial efficacy screening assay [corrected zone of inhibition (CZOI)]. The mean overall CZOI for the Gram-positive isolates at a pH of 5·5 were very similar for both dressings. A mean CZOI of 5 mm was recorded for the SCMC dressing, which was slightly higher, at 5·4 mm for the SA dressing. At a pH of 7·0 both dressings, in general, showed a similar activity. However, at a pH of 8·5 the mean CZOI of the SCMC dressing was found to be significantly (P < 0·05) higher than the SA dressing for a select number of isolates. The mean overall CZOI for the Gram-negative bacteria followed a similar pattern as observed with the Gram-positive bacteria. Susceptibility to silver ions did vary significantly

  12. 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

    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.

  13. Isolation and characterization of novel iron-oxidizing bacteria that grow at circumneutral pH.

    PubMed Central

    Emerson, D; Moyer, C

    1997-01-01

    A gel-stabilized gradient method that employed opposing gradients of Fe2+ and O2 was used to isolate and characterize two new Fe-oxidizing bacteria from a neutral pH, Fe(2+)-containing groundwater in Michigan. Two separate enrichment cultures were obtained, and in each the cells grew in a distinct, rust-colored band in the gel at the oxic-anoxic interface. The cells were tightly associated with the ferric hydroxides. Repeated serial dilutions of both enrichments resulted in the isolation of two axenic strains, ES-1 and ES-2. The cultures were judged pure based on (i) growth from single colonies in tubes at dilutions of 10(-7) (ES-2) (ES-2) and 10(-8) (ES-1); (ii) uniform cell morphologies, i.e., ES-1 was a motile long thin, bent, or S-shaped rod and ES-2 was a shorter curved rod; and (iii) no growth on a heterotrophic medium. Strain ES-1 grew to a density of 10(8) cells/ml on FeS with a doubling time of 8 h. Strain ES-2 grew to a density of 5 x 10(7) cells/ml with a doubling time of 12.5 h. Both strains also grew on FeCO3. Neither strain grew without Fe2+, nor did they grow with glucose, pyruvate, acetate, Mn, or H2S as an electron donor. Studies with an oxygen microelectrode revealed that both strains grew at the oxic-anoxic interface of the gradients and tracked the O2 minima when subjected to higher O2 concentrations, suggesting they are microaerobes. Phylogenetically the two strains formed a novel lineage within the gamma Proteobacteria. They were very closely related to each other and were equally closely related to PVB OTU 1, a phylotype obtained from an iron-rich hydrothermal vent system at the Loihi Seamount in the Pacific Ocean, and SPB OTU 1, a phylotype obtained from permafrost soil in Siberia. Their closest cultivated relative was Stenotrophomonas maltophilia. In total, this evidence suggests ES-1 and ES-2 are members of a previously untapped group of putatively lithotrophic, unicellular iron-oxidizing bacteria. PMID:9406396

  14. Cross-class metallo-β-lactamase inhibition by bisthiazolidines reveals multiple binding modes.

    PubMed

    Hinchliffe, Philip; González, Mariano M; Mojica, Maria F; González, Javier M; Castillo, Valerie; Saiz, Cecilia; Kosmopoulou, Magda; Tooke, Catherine L; Llarrull, Leticia I; Mahler, Graciela; Bonomo, Robert A; Vila, Alejandro J; Spencer, James

    2016-06-28

    Metallo-β-lactamases (MBLs) hydrolyze almost all β-lactam antibiotics and are unaffected by clinically available β-lactamase inhibitors (βLIs). Active-site architecture divides MBLs into three classes (B1, B2, and B3), complicating development of βLIs effective against all enzymes. Bisthiazolidines (BTZs) are carboxylate-containing, bicyclic compounds, considered as penicillin analogs with an additional free thiol. Here, we show both l- and d-BTZ enantiomers are micromolar competitive βLIs of all MBL classes in vitro, with Kis of 6-15 µM or 36-84 µM for subclass B1 MBLs (IMP-1 and BcII, respectively), and 10-12 µM for the B3 enzyme L1. Against the B2 MBL Sfh-I, the l-BTZ enantiomers exhibit 100-fold lower Kis (0.26-0.36 µM) than d-BTZs (26-29 µM). Importantly, cell-based time-kill assays show BTZs restore β-lactam susceptibility of Escherichia coli-producing MBLs (IMP-1, Sfh-1, BcII, and GOB-18) and, significantly, an extensively drug-resistant Stenotrophomonas maltophilia clinical isolate expressing L1. BTZs therefore inhibit the full range of MBLs and potentiate β-lactam activity against producer pathogens. X-ray crystal structures reveal insights into diverse BTZ binding modes, varying with orientation of the carboxylate and thiol moieties. BTZs bind the di-zinc centers of B1 (IMP-1; BcII) and B3 (L1) MBLs via the free thiol, but orient differently depending upon stereochemistry. In contrast, the l-BTZ carboxylate dominates interactions with the monozinc B2 MBL Sfh-I, with the thiol uninvolved. d-BTZ complexes most closely resemble β-lactam binding to B1 MBLs, but feature an unprecedented disruption of the D120-zinc interaction. Cross-class MBL inhibition therefore arises from the unexpected versatility of BTZ binding. PMID:27303030

  15. 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

  16. The antimicrobial efficacy of silver on antibiotic-resistant bacteria isolated from burn wounds.

    PubMed

    Percival, Steven L; Thomas, John; Linton, Sara; Okel, Tyler; Corum, Linda; Slone, Will

    2012-10-01

    The antibiotic-resistant bacteria are a major concern to wound care because of their ability to resist many of the antibiotics used today to treat infections. Consequently, other antimicrobials, in particular ionic silver, are considered ideal topical agents for effectively helping to manage and prevent local infections. Little is known about the antimicrobial efficacy of ionic silver on antibiotic-resistant bacteria at different pH values. Consequently, in this study our aim was to evaluate the effect of pH on the antimicrobial efficacy of a silver alginate (SA) and a silver carboxymethyl cellulose (SCMC) dressing on antibiotic-resistant bacteria isolated from burn patients. Forty-nine antibiotic-resistant bacteria, including Vancomycin-resistant Enterococcus faecium, meticillin-resistant Staphylococcus aureus, multidrug-resistant (MDR) Pseudomonas aeruginosa, MDR Vibrio sp, MDR Stenotrophomonas maltophilia, extended-spectrum ß-lactamase (ESBL) producing Salmonella sp, ESBL producing Klebsiella pneumoniae, ESBL producing Proteus mirabilis, ESBL producing Escherichia coli and MDR Acinetobacter baumannii, routinely isolated from burn wounds were used in the study and evaluated for their susceptibility to two silver containing wound dressings using a standardised antimicrobial efficacy screening assay [corrected zone of inhibition (CZOI)]. The mean overall CZOI for the Gram-positive isolates at a pH of 5·5 were very similar for both dressings. A mean CZOI of 5 mm was recorded for the SCMC dressing, which was slightly higher, at 5·4 mm for the SA dressing. At a pH of 7·0 both dressings, in general, showed a similar activity. However, at a pH of 8·5 the mean CZOI of the SCMC dressing was found to be significantly (P < 0·05) higher than the SA dressing for a select number of isolates. The mean overall CZOI for the Gram-negative bacteria followed a similar pattern as observed with the Gram-positive bacteria. Susceptibility to silver ions did vary significantly

  17. 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

  18. Ceftobiprole Activity against over 60,000 Clinical Bacterial Pathogens Isolated in Europe, Turkey, and Israel from 2005 to 2010

    PubMed Central

    Flamm, Robert K.; Sader, Helio S.; Jones, Ronald N.

    2014-01-01

    Ceftobiprole medocaril is a newly approved drug in Europe for the treatment of hospital-acquired pneumonia (HAP) (excluding patients with ventilator-associated pneumonia but including ventilated HAP patients) and community-acquired pneumonia in adults. The aim of this study was to evaluate the in vitro antimicrobial activity of ceftobiprole against prevalent Gram-positive and -negative pathogens isolated in Europe, Turkey, and Israel during 2005 through 2010. A total of 60,084 consecutive, nonduplicate isolates from a wide variety of infections were collected from 33 medical centers. Species identification was confirmed, and all isolates were susceptibility tested using reference broth microdilution methods. Ceftobiprole had high activity against methicillin-susceptible Staphylococcus aureus (MSSA) (100.0% susceptible), methicillin-susceptible coagulase-negative staphylococci (CoNS), beta-hemolytic streptococci, and Streptococcus pneumoniae (99.3% susceptible), with MIC90 values of 0.25, 0.12, ≤0.06, and 0.5 μg/ml, respectively. Ceftobiprole was active against methicillin-resistant S. aureus (MRSA) (98.3% susceptible) and methicillin-resistant CoNS, having a MIC90 of 2 μg/ml. Ceftobiprole was active against Enterococcus faecalis (MIC50/90, 0.5/4 μg/ml) but not against most Enterococcus faecium isolates. Ceftobiprole was very potent against the majority of Enterobacteriaceae (87.3% susceptible), with >80% inhibited at ≤0.12 μg/ml. The potency of ceftobiprole against Pseudomonas aeruginosa (MIC50/90, 2/>8 μg/ml; 64.6% at MIC values of ≤4 μg/ml) was similar to that of ceftazidime (MIC50/90, 2/>16 μg/ml; 75.4% susceptible), but limited activity was observed against Acinetobacter spp. and Stenotrophomonas maltophilia. High activity was also observed against all Haemophilus influenzae (MIC90, ≤0.06 μg/ml) and Moraxella catarrhalis (MIC50/90, ≤0.06/0.25 μg/ml) isolates. Ceftobiprole demonstrated a wide spectrum of antimicrobial activity against this

  19. Analysis of bacterial community structure in sulfurous-oil-containing soils and detection of species carrying dibenzothiophene desulfurization (dsz) genes.

    PubMed

    Duarte, G F; Rosado, A S; Seldin, L; de Araujo, W; van Elsas, J D

    2001-03-01

    . 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.

  20. In vitro evaluation of the probiotic and functional potential of Lactobacillus strains isolated from fermented food and human intestine.

    PubMed

    Ren, Dayong; Li, Chang; Qin, Yanqing; Yin, Ronglan; Du, Shouwen; Ye, Fei; Liu, Cunxia; Liu, Hongfeng; Wang, Maopeng; Li, Yi; Sun, Yang; Li, Xiao; Tian, Mingyao; Jin, Ningyi

    2014-12-01

    This study aims to evaluate the functional and probiotic characteristics of eight indigenous Lactobacillus strains in vitro. The selected lactobacilli include strains of Lactobacillus casei subsp. casei, Lactobacillus salivarius subsp. salicinius, Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus delbrueckii subsp. lactis, Lactobacillus delbrueckii subsp. bulgaricus, and Lactobacillus rhamnosus. All strains tolerated both pH 2 for 3 h and 1% bile salt for 24 h. The strains CICC 23174 and CGMCC 1.557 were the most adhesive strains producing the highest quantity of EPS. Although a wide variation in the ability of the eight strains to deplete cholesterol and nitrite, antagonize pathogens, scavenge free radical, and stimulate innate immune response were observed, the strains CICC 23174 and CGMCC 1.557 showed the widest range of these useful traits. Taken together, the strains CICC 23174 and CGMCC 1.557 exhibited the best probiotic properties with the potential for use in the production of probiotic fermented foods.

  1. Streptomyces ferrugineus sp. nov., isolated from mangrove soil in Thailand.

    PubMed

    Ruan, Chang-ying; Zhang, Li; Ye, Wan-wan; Xie, Xiu-chao; Srivibool, Rattanaporn; Duangmal, Kannika; Pathom-aree, Wasu; Deng, Zi-xin; Hong, Kui

    2015-01-01

    Bacterial strain HV38(T) was isolated from mangrove soil, which was collected from Thailand. Chemotaxonomic and morphological characteristics were found to be typical of members of the genus Streptomyces. The strain was found to form a distinct phyletic line in the Streptomyces 16S rRNA gene tree and to be closely associated with the type strains of Streptomyces coeruleofuscus CGMCC 4.1667(T) (98.84 % sequence similarity), Streptomyces chromofuscus CGMCC 4.1451(T) (98.63 %) and Streptomyces albidoflavus CGMCC 4.1291(T) (98.56 %). The major menaquinones were identified as MK-9(H8) and MK-9(H10). Its major cellular fatty acids were found to be iso-C14:0, iso-C15:0, anteiso-C15:0, iso-C16:1ω8c, C16:0, anteiso-C16:1ω8c, iso-C16:0 and anteiso-C16:0. The DNA-DNA hybridization values between strain HV38(T) with S. coeruleofuscus CGMCC 4.1667(T), S. chromofuscus CGMCC 4.1451(T) and S. albidoflavus CGMCC 4.1291(T) were 32.7 ± 0.9, 21.8 ± 0.3 and 19.9 ± 0.9 %, respectively, which clearly supported the conclusion that they belong to separate genomic species. Cumulatively, the data indicated that strain HV38(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces ferrugineus sp. nov. is proposed. The type strain is HV38(T) (=CCTCC AA2014009(T )= DSM 42152(T)). PMID:25331336

  2. Phylogenomic analysis shows that ‘Bacillus vanillea’ is a later heterotypic synonym of Bacillus siamensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Bacillus vanillea’ XY18T (=CGMCC 8629 T =NCCB 100507 T) was isolated from cured vanilla beans and involved in the formation of vanilla aroma compounds. A draft genome of this type strain was assembled and yielded a length of 3.72 Mbp and a GC content of 46.3%. Comparative genomic analysis with its ...

  3. Marinobacter nanhaiticus sp. nov., polycyclic aromatic hydrocarbon-degrading bacterium isolated from the sediment of the South China Sea.

    PubMed

    Gao, Wei; Cui, Zhisong; Li, Qian; Xu, Guangsu; Jia, Xingjun; Zheng, Li

    2013-03-01

    A Gram-negative, rod-shaped, slightly halophilic and facultatively anaerobic bacterium, designated strain D15-8W(T), was isolated from the sediment of the South China Sea. Growth was found to occur optimally at 25 °C, between pH 7.0 and 8.0 and with 1-5 % (w/v) NaCl. The strain was observed to utilize a variety of organic substrates and polycyclic aromatic hydrocarbons as sole carbon sources. The G+C content of the genomic DNA was determined to be 58.7 %. The predominant respiratory quinone was found to be Q-9. The significant fatty acids were determined to be C(16:0), C(16:1) ω9c, C(18:1) ω9c, C(12:0) and C(14:0) 3OH. Analysis of 16S rRNA gene sequences showed that strain D15-8W(T) fits within the phylogenetic cluster of the genus Marinobacter and is most closely related to Marinobacter segnicrescens CGMCC 1.6489(T), Marinobacter bryozoorum DSM 15401(T), Marinobacter lacisalsi CECT 7297(T) and Marinobacter daqiaonensis CGMCC1.9167(T). The DNA-DNA hybridization values between strain D15-8W(T) and the type strains of the most closely related species were 42.3 % (CGMCC 1.6489(T)), 39.8 % (DSM 15401(T)), 37.3 % (CECT 7297(T)) and 35.2 % (CGMCC1.9167(T)). The results of this polyphasic study indicate that strain D15-8W(T) represents a novel species of the genus Marinobacter, for which the name Marinobacter nanhaiticus sp. nov. is proposed. The type strain is D15-8W(T) (=CGMCC 1.11019(T)=KCTC 23749(T)).

  4. 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.

  5. 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.

  6. Evaluation of immunomodulatory activity of two potential probiotic Lactobacillus strains by in vivo tests.

    PubMed

    Ren, Dayong; Li, Chang; Qin, Yanqing; Yin, Ronglan; Du, Shouwen; Liu, Hongfeng; Zhang, Yanfang; Wang, Cuiyan; Rong, Fengjun; Jin, Ningyi

    2015-10-01

    Here we evaluate the immunomodulatory function of two potential probiotic strains, Lactobacillus salivarius CICC 23174 and Lactobacillus plantarum CGMCC 1.557. Mice were fed with each Lactobacillus strain at different doses for several consecutive days. The effects of the two probiotic strains on immune organs, immune cells and immune molecules were investigated on days 10 and 20. Both Lactobacillus strains increased the spleen index, improved the spleen lymphocyte transformation rate, enhanced sIgA production and improved the number of CD11c(+) CD80(+) double-positive cells. L. plantarum CGMCC 1.557 was the more active strain in enhancing the phagocytic activity of macrophages, while, L. salivarius CICC 23174 was the more effective strain at maintaining the Th1/Th2 balance. This study suggests that these two Lactobacillus strains have beneficial effects on regulation of immune responses, which has promising implications for the development of ecological agents and functional foods.

  7. Analyzing the antagonistic potential of the lichen microbiome against pathogens by bridging metagenomic with culture studies.

    PubMed

    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

  8. Effects of different osmolarities on bacterial biofilm formation

    PubMed Central

    Kavamura, Vanessa Nessner; de Melo, Itamar Soares

    2014-01-01

    Biofilm formation depends on several factors. The influence of different osmolarities on bacterial biofilm formation was studied. Two strains (Enterobacter sp. and Stenotrophomonas sp.) exhibited the most remarkable alterations. Biofilm formation is an important trait and its use has been associated to the protection of organisms against environmental stresses. PMID:25242950

  9. 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

  10. 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.

  11. Streptomyces bryophytorum sp. nov., an endophytic actinomycete isolated from moss (Bryophyta).

    PubMed

    Li, Chuang; Jin, Pinjiao; Liu, Chongxi; Ma, Zhaoxu; Zhao, Junwei; Li, Jiansong; Wang, Xiangjing; Xiang, Wensheng

    2016-09-01

    A novel endophytic actinomycete, designated strain NEAU-HZ10(T) was isolated from moss and characterised using a polyphasic approach. The strain was found to have morphological and chemotaxonomic characteristics typical of the genus Streptomyces. Strain NEAU-HZ10(T) formed grayish aerial mycelia, which differentiated into straight to flexuous chains of cylindrical spores. The cell wall peptidoglycan was found to contain LL-diaminopimelic acid. Predominant menaquinones were identified as MK-9(H6) and MK-9(H8). The polar lipid profile was found to consist of phosphatidylethanolamine, phosphatidylinositol and two unidentified phospholipids. The major fatty acids were identified as iso-C16:0, anteiso-C15:0 and C16:0. 16S rRNA gene sequence similarity studies showed that strain NEAU-HZ10(T) belongs to the genus Streptomyces and exhibits high sequence similarity to Streptomyces cocklensis DSM 42063(T) (98.9 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-HZ10(T) clustered with S. cocklensis DSM 42063(T), Streptomyces yeochonensis CGMCC 4.1882(T) (98.7 %), Streptomyces paucisporeus CGMCC 4.2025(T) (98.4 %) and Streptomyces yanglinensis CGMCC 4.2023(T) (98.1 %). However, a combination of DNA-DNA hybridisation results and some phenotypic characteristics indicated that strain NEAU-HZ10(T) can be distinguished from its phylogenetically closely related strains. Therefore, it is proposed that strain NEAU-HZ10(T) represents a novel species of the genus Streptomyces for which the name Streptomyces bryophytorum sp. nov. is proposed. The type strain is NEAU-HZ10(T) (= CGMCC 4.7151(T) = DSM 42138(T)).

  12. Streptomyces bryophytorum sp. nov., an endophytic actinomycete isolated from moss (Bryophyta).

    PubMed

    Li, Chuang; Jin, Pinjiao; Liu, Chongxi; Ma, Zhaoxu; Zhao, Junwei; Li, Jiansong; Wang, Xiangjing; Xiang, Wensheng

    2016-09-01

    A novel endophytic actinomycete, designated strain NEAU-HZ10(T) was isolated from moss and characterised using a polyphasic approach. The strain was found to have morphological and chemotaxonomic characteristics typical of the genus Streptomyces. Strain NEAU-HZ10(T) formed grayish aerial mycelia, which differentiated into straight to flexuous chains of cylindrical spores. The cell wall peptidoglycan was found to contain LL-diaminopimelic acid. Predominant menaquinones were identified as MK-9(H6) and MK-9(H8). The polar lipid profile was found to consist of phosphatidylethanolamine, phosphatidylinositol and two unidentified phospholipids. The major fatty acids were identified as iso-C16:0, anteiso-C15:0 and C16:0. 16S rRNA gene sequence similarity studies showed that strain NEAU-HZ10(T) belongs to the genus Streptomyces and exhibits high sequence similarity to Streptomyces cocklensis DSM 42063(T) (98.9 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-HZ10(T) clustered with S. cocklensis DSM 42063(T), Streptomyces yeochonensis CGMCC 4.1882(T) (98.7 %), Streptomyces paucisporeus CGMCC 4.2025(T) (98.4 %) and Streptomyces yanglinensis CGMCC 4.2023(T) (98.1 %). However, a combination of DNA-DNA hybridisation results and some phenotypic characteristics indicated that strain NEAU-HZ10(T) can be distinguished from its phylogenetically closely related strains. Therefore, it is proposed that strain NEAU-HZ10(T) represents a novel species of the genus Streptomyces for which the name Streptomyces bryophytorum sp. nov. is proposed. The type strain is NEAU-HZ10(T) (= CGMCC 4.7151(T) = DSM 42138(T)). PMID:27263023

  13. Draft Genome Sequence of the Bioelectricity-Generating and Dye-Decolorizing Bacterium Proteus hauseri Strain ZMd44

    PubMed Central

    Wang, Nan; Li, Yuzhe; Chen, Yi-Chung; Chen, Bor-Yann; Lu, Yinghua

    2014-01-01

    Proteus hauseri ZMd44 (CGMCC 6746), as a crucial biodecolorizing, bioelectricity-generating, and copper-resistant bacterium, is distinguished from the urinary pathogens Proteus penneri and Proteus mirabilis. To further investigate the genetic functions of this strain, the genome sequence and annotation of its open reading frames, which consist of 3,875,927 bp (G+C content, 38.12%), are presented here. PMID:24435854

  14. Draft Genome Sequence of the Bioelectricity-Generating and Dye-Decolorizing Bacterium Proteus hauseri Strain ZMd44.

    PubMed

    Wang, Nan; Ng, I-Son; Chen, Po Ting; Li, Yuzhe; Chen, Yi-Chung; Chen, Bor-Yann; Lu, Yinghua

    2014-01-16

    Proteus hauseri ZMd44 (CGMCC 6746), as a crucial biodecolorizing, bioelectricity-generating, and copper-resistant bacterium, is distinguished from the urinary pathogens Proteus penneri and Proteus mirabilis. To further investigate the genetic functions of this strain, the genome sequence and annotation of its open reading frames, which consist of 3,875,927 bp (G+C content, 38.12%), are presented here.

  15. Efficient glycosylation of puerarin by an organic solvent-tolerant strain of Lysinibacillus fusiformis.

    PubMed

    Wang, Siyuan; Liu, Guiyou; Zhang, Wen; Cai, Nan; Cheng, Cheng; Ji, Yin; Sun, Lei; Zhan, Jixun; Yuan, Sheng

    2014-04-10

    A bacterial strain able to glycosylate the plant natural product puerarin was isolated from local soil in Nanjing, China. It was identified as Lysinibacillus fusiformis, and deposited in China General Microbiological Culture Collection (CGMCC) under accession number 4913. Incubation of this strain with puerarin led to efficient production (91.6% conversation rate) of puerarin-7-O-fructoside, a derivative that possesses improved water solubility and antioxidant activity. A minor product puerarin-7-O-isomaltoside was also produced in small amounts, with a conversion rate of less than 1% after 48-h reaction. Both products were characterized based on the spectral data. Among the four tested sugars, sucrose (92.6% conversion rate of puerarin) is the best glycosyl donor for L. fusiformis CGMCC 4913, followed by maltose (39.8% conversion rate of puerarin), while glucose and fructose are not appropriate donors for this biotransformation process. L. fusiformis CGMCC 4913 can survive in the presence of 10% (v/v) organic solvents such as methanol, ethanol, toluene, cyclohexane, and dimethyl sulfoxide. The biotransformation efficiency of puerarin was increased 2-fold in the presence of 10% ethanol at 12 h compared to the transformation solution without ethanol. The optimum pH and substrate concentration are 8.0 and 4 g/L, respectively. Under the optimal conditions, the final conversion rate of puerarin reached 97.6±2.3% at 48 h in the presence of 10% ethanol. Therefore, L. fusiformis CGMCC 4913 represents a new and efficient biocatalyst for the biotransformation of puerarin. PMID:24629266

  16. Metabolic flux analysis of Gluconacetobacter xylinus for bacterial cellulose production.

    PubMed

    Zhong, Cheng; Zhang, Gui-Cai; Liu, Miao; Zheng, Xin-Tong; Han, Pei-Pei; Jia, Shi-Ru

    2013-07-01

    Metabolic flux analysis was used to reveal the metabolic distributions in Gluconacetobacter xylinus (CGMCC no. 2955) cultured on different carbon sources. Compared with other sources, glucose, fructose, and glycerol could achieve much higher bacterial cellulose (BC) yields from G. xylinus (CGMCC no. 2955). The glycerol led to the highest BC production with a metabolic yield of 14.7 g/mol C, which was approximately 1.69-fold and 2.38-fold greater than that produced using fructose and glucose medium, respectively. The highest BC productivity from G. xylinus CGMCC 2955 was 5.97 g BC/L (dry weight) when using glycerol as the sole carbon source. Metabolic flux analysis for the central carbon metabolism revealed that about 47.96 % of glycerol was transformed into BC, while only 19.05 % of glucose and 24.78 % of fructose were transformed into BC. Instead, when glucose was used as the sole carbon source, 40.03 % of glucose was turned into the by-product gluconic acid. Compared with BC from glucose and fructose, BC from the glycerol medium showed the highest tensile strength at 83.5 MPa, with thinner fibers and lower porosity. As a main byproduct of biodiesel production, glycerol holds great potential to produce BC with superior mechanical and microstructural characteristics.

  17. Rhizobacterial volatiles affect the growth of fungi and Arabidopsis thaliana.

    PubMed

    Vespermann, Anja; Kai, Marco; Piechulla, Birgit

    2007-09-01

    Volatiles of Stenotrophomonas, Serratia, and Bacillus species inhibited mycelial growth of many fungi and Arabidopsis thaliana (40 to 98%), and volatiles of Pseudomonas species and Burkholderia cepacia retarded the growth to lesser extents. Aspergillus niger and Fusarium species were resistant, and B. cepacia and Staphylococcus epidermidis promoted the growth of Rhizoctonia solani and A. thaliana. Bacterial volatiles provide a new source of compounds with antibiotic and growth-promoting features.

  18. Flavobacterium xueshanense sp. nov. and Flavobacterium urumqiense sp. nov., two psychrophilic bacteria isolated from glacier ice.

    PubMed

    Dong, Kun; Liu, Hongcan; Zhang, Jianli; Zhou, Yuguang; Xin, Yuhua

    2012-05-01

    Two Gram-stain-negative, rod-shaped bacteria, designated strains Sr22(T) and Sr25(T), were isolated from water of melted ice from the China No.1 glacier, Xinjiang Uygur Autonomous Region, China. Cells formed yellow, circular, convex colonies. 16S rRNA gene sequence analysis indicated that strains Sr22(T) and Sr25(T) belong to the genus Flavobacterium, sharing ≤99.1  and ≤99.6 % similarity, respectively, with the type strains of recognized species of the genus. Strain Sr22(T) shared highest 16S rRNA gene sequence similarity with Flavobacterium tiangeerense CGMCC 1.6847(T) (98.6 %), Flavobacterium fryxellicola LMG 22022(T) (98.1 %) and Flavobacterium omnivorum CGMCC 1.2747(T) (99.1 %). Strain Sr25(T) shared highest similarity with Flavobacterium sinopsychrotolerans CGMCC 1.8704(T) (98.5 %), Flavobacterium degerlachei NBRC 102677(T) (98.4 %) and Flavobacterium xinjiangense CGMCC 1.2749(T) (99.5 %). The predominant fatty acids of strain Sr22(T) were iso-C(15 : 1) G (6.01 %), iso-C(15 : 0) (8.93 %), iso-C(16 : 1) H (12.68 %), iso-C(16 : 0) (10.4 %), C(15 : 1)ω6c (8.97 %), C(17 : 1)ω6c (5.96 %), iso-C(16 : 0) 3-OH (11.14 %) and summed feature 3 (comprising C(16 : 1)ω7c and/or C(16 : 1)ω6c, 12.33 %). The major fatty acids of strain Sr25(T) were iso-C(15 : 0) (10.8 %), anteiso-C(15 : 0) (5.23 %), C(15 : 1)ω6c (11.79 %), C(17 : 1)ω6c (5.43 %), iso-C(16 : 0) 3-OH (7.04 %) and summed feature 3 (20.42 %). The genomic DNA G+C contents of strains Sr22(T) and Sr25(T) were 37.2 and 35.1 mol%. On the basis of differential phenotypic and phylogenetic characteristics, these strains are considered to represent two novel species of the genus Flavobacterium, for which the names Flavobacterium xueshanense sp. nov. (type strain Sr22(T)  = CGMCC 1.9227(T)  = NBRC 106479(T)) and Flavobacterium urumqiense sp. nov. (type strain Sr25(T)  = CGMCC 1.9230(T)  = NBRC 106480

  19. Streptomyces rubrisoli sp. nov., neutrotolerant acidophilic actinomycetes isolated from red soil.

    PubMed

    Guo, Xiaoxuan; Zhang, Limin; Li, Xiaomin; Gao, Yongsheng; Ruan, Jisheng; Huang, Ying

    2015-09-01

    Three neutrotolerant, acidophilic actinomycete strains, designated FXJ1.526, FXJ1.725(T) and FXJ1.726, were isolated from red soil collected from Liujiazhan, Jiangxi Province, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the three strains clustered together and their closest relative was Streptomyces ferralitis CGMCC 4.1985(T) (98.9-99.0% similarity). Multilocus sequence analysis confirmed their relationship to S. ferralitis and separated these strains as representing a novel species. Mean DNA-DNA hybridization values among strains FXJ1.526, FXJ1.725(T) and FXJ1.726 were 81.6 ± 3.5-87.2 ± 3.8%, and the values between the three strains and S. ferralitis CGMCC 4.1985(T) were well below 70%. The three strains also shared several phenotypic characteristics that were distinct from the closely related species. They grew at 21-50 °C, at pH 4.0-9.0 (with an optimal pH of 5.0) and with 0-3% (w/v) NaCl, and the major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0 and iso-C16 : 0. On the basis of data from this polyphasic taxonomic study, it is proposed that strains FXJ1.526, FXJ1.725(T) and FXJ1.726 be classified as representatives of a novel species of the genus Streptomyces, with the name Streptomyces rubrisoli sp. nov. The type strain is FXJ1.725(T) ( = CGMCC 4.7025(T)= DSM 42083(T)).

  20. The opposite roles of agdA and glaA on citric acid production in Aspergillus niger.

    PubMed

    Wang, Lu; Cao, Zhanglei; Hou, Li; Yin, Liuhua; Wang, Dawei; Gao, Qiang; Wu, Zhenqiang; Wang, Depei

    2016-07-01

    Citric acid is produced by an industrial-scale process of fermentation using Aspergillus niger as a microbial cell factory. However, citric acid production was hindered by the non-fermentable isomaltose and insufficient saccharification ability in A. niger when liquefied corn starch was used as a raw material. In this study, A. niger TNA 101ΔagdA was constructed by deletion of the α-glucosidase-encoding agdA gene in A. niger CGMCC 10142 genome using Agrobacterium tumefaciens-mediated transformation. The transformants A. niger OG 1, OG 17, and OG 31 then underwent overexpression of glucoamylase in A. niger TNA 101ΔagdA. The results showed that the α-glucosidase activity of TNA 101ΔagdA was decreased by 62.5 % compared with CGMCC 10142, and isomaltose was almost undetectable in the fermentation broth. The glucoamylase activity of the transformants OG 1 and OG 17 increased by 34.5 and 16.89 % compared with that of TNA 101ΔagdA, respectively. In addition, for the recombinants TNA 101ΔagdA, OG 1 and OG 17, there were no apparent defects in the growth development. Consequently, in comparison with CGMCC 10142, TNA 101ΔagdA and OG 1 decreased the residual reducing sugar by 52.95 and 88.24 %, respectively, and correspondingly increased citric acid production at the end of fermentation by 8.68 and 16.87 %. Citric acid production was further improved by decreasing the non-fermentable residual sugar and increasing utilization rate of corn starch material in A. niger. Besides, the successive saccharification and citric acid fermentation processes were successfully integrated into one step.

  1. Marinobacter daqiaonensis sp. nov., a moderate halophile isolated from a Yellow Sea salt pond.

    PubMed

    Qu, Lingyun; Zhu, Fengling; Zhang, Jinxing; Gao, Chunlei; Sun, Xiuqin

    2011-12-01

    A Gram-negative, oxidase- and catalase-positive, moderately halophilic strain, designated YCSA40(T), was isolated from sediment of Daqiao saltern in Qingdao, on the east coast of China. Growth occurred at 10-45 °C, at pH 5-9 and with 1-15% NaCl. Strain YCSA40(T) showed the highest 16S rRNA gene sequence similarity to Marinobacter segnicrescens SS011B1-4(T) (97%) and M. gudaonensis SL014B61A(T) (96.9%) and 16S rRNA gene sequence phylogenetic analysis assigned the isolate to the genus Marinobacter. Strain YCSA40(T) contained C(18:1)ω9c (34.8%), C(16:0) (11.6%), C(19:0) cyclo ω10c/C(19:1)ω6c (10.5%), C(16:1)ω9c (8.4%), C(17:0) (6.3%) and C(12:0) 3-OH (5.8%) as the predominant fatty acids. The DNA G+C content was 60.8 mol% and the major ubiquinone was Q-9. These chemotaxonomic characters were all consistent with membership of the genus Marinobacter. DNA-DNA relatedness between the isolate and M. segnicrescens CGMCC 1.6489(T), M. gudaonensis CGMCC 1.6294(T) and other type strains of species of the genus Marinobacter was ≤30%. On the basis of the aforementioned data, it was concluded that strain YCSA40(T) represents a novel species of the genus Marinobacter, for which the name Marinobacter daqiaonensis sp. nov. is proposed. The type strain is YCSA40(T) (=CGMCC 1.9167(T) =NCCB 100308(T) =LMG 25365(T)).

  2. Gracilibacillus marinus sp. nov., isolated from the northern South China Sea.

    PubMed

    Huang, Hui-qin; Wang, Ying; Yuan, Wei-dao; Xiao, Chuan; Ye, Jian-jun; Liu, Min; Zhu, Jun; Sun, Qian-guang; Bao, Shi-xiang

    2013-11-01

    Two gram-positive, aerobic, spore-forming, rod-shaped bacteria, designated HB09003(T) and HB12160, were isolated from seawater and sediment in the northern South China Sea, respectively. Cells were found to be motile by means of peritrichous flagella. The strains were found to grow with 0-15 % (w/v) NaCl, at 10-45 °C and pH 5.0-10.7, with an optimum of 3 % NaCl, 28 °C and pH 8.5, respectively. The predominant isoprenoid quinone of strain HB09003(T), selected as the representative strain, was identified as MK-7. This strain was found to possess anteiso-C15:0, iso-C15:0, anteiso-C17:0 and C16:0 as the major fatty acids. The G+C contents of strain HB09003(T) and HB12160 were determined to be 34.1 and 34.3 mol%, respectively. Analysis of the 16S rRNA gene sequences of the two strains showed an affiliation with the genus Gracilibacillus, with Gracilibacillus kekensis CGMCC 1.10681(T) (similarity of 97.4, 98.0 %, respectively) and Gracilibacillus ureilyticus CGMCC 1.7727(T) (similarity of 97.1, 97.8 %, respectively) as their closest relatives. The DNA-DNA hybridization values between strain HB09003(T) and the two type strains were 42.2 and 54.1 %, respectively. On the basis of phenotypic and genotypic data, strain HB09003(T) and HB12160 are proposed to represent a novel species of the genus Gracilibacillus, for which the name Gracilibacillus marinus sp. nov. is proposed. The type strain is HB09003(T) (=CGMCC 1.10343(T) = DSM 23372(T)).

  3. Hamadaea flava sp. nov., isolated from a soil sample and emended description of the genus Hamadaea.

    PubMed

    Chu, Xiao; Li, Shuai; Chen, Wei; Devi Asem, Mipeshwaree; Duan, Yan-Qing; Nie, Guo-Xing; Hozzein, Wael N; Zhi, Xiao-Yang; Li, Wen-Jun

    2016-04-01

    A Gram-stain-positive, aerobic and non-motile actinobacterial strain, designated YIM C0533T, was isolated from a soil sample collected from Shiling county, Yunnan province, south-west China. The isolate grew at 15-37 °C, pH 6.0-8.0 and in the presence of 0-3% (w/v) NaCl. The whole-cell hydrolysates contained meso-diaminopimelic acid, xylose, galactose, mannose, ribose, arabinose, glucose and rhamnose. The acyl type of muramic acid was glycolyl. The polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified phospholipid. The major cellular fatty acids were iso-C16:0, 10-methyl C17:0 and iso-C15 : 0.MK-9(H6) was the predominant menaquinone. The genomic DNA G+C content was determined to be 69.4 mol%. These chemotaxonomic data and the morphological properties were consistent with those of the genus Hamadaea. The strain showed highest sequence similarities to Hamadaea tsunoensis CGMCC 4.1403T on phylogenetic analysis of 16S rRNA gene sequences and was found to form a coherent cluster in the neighbour-joining tree. The DNA-DNA hybridization experiment indicated that the DNA-DNA relatedness value between strain YIM C0533T and H. tsunoensis CGMCC 4.1403T was 34.4±1.3 %. In addition, the results of physiological and biochemical tests allowed the isolate to be differentiated phenotypically from H. tsunoensis CGMCC 4.1403T. On the basis of data from this polyphasic study, strain YIM C0533T is characterized as a novel species of the genus Hamadaea, for which the name Hamadaea flava sp. nov. is proposed. The type strain is YIM C0533T (=CPCC 204160T=KCTC 39591T=CGMCC 4.7289T). An emended description of the genus Hamadaea is also provided. PMID:26842996

  4. Complete genome sequence of the novel thermophilic polyhydroxyalkanoates producer Aneurinibacillus sp. XH2 isolated from Gudao oilfield in China.

    PubMed

    Xi, Lijun; Zhang, Zhenchong; Qiao, Nenghu; Zhang, Yu; Li, Jing; Zhao, Jing-Yi; Xiao, Zijun

    2016-06-10

    Aneurinibacillus sp. XH2 (CGMCC 1.15535) was isolated from Gudao oilfield in China. It is able to use simple carbon resources to accumulate Polyhydroxyalkanoates (PHAs) in a thermophilic fashion. Here, we describe the genomic features of this strain. The total genome size of Aneurinibacillus sp. XH2 is 3,664,835bp and contains 3441 coding sequences and 114 tRNAs. The annotated genome sequence of this strain provides the genetic basis for revealing its role as a themophilic PHAs producing bacterium. PMID:27046067

  5. 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

  6. Micromonospora rifamycinica sp. nov., a novel actinomycete from mangrove sediment.

    PubMed

    Huang, Huiqin; Lv, Jiasen; Hu, Yonghua; Fang, Zhe; Zhang, Kaishan; Bao, Shixiang

    2008-01-01

    An actinomycete strain, AM105(T), that produces rifamycin, was isolated from mangrove sediment samples collected from the South China Sea. The strain showed closest 16S rRNA gene sequence similarity to Micromonospora matsumotoense (98.0%). Chemotaxonomic characteristics of the isolate coincided with members of the genus Micromonospora. The value of DNA-DNA relatedness to M. matsumotoense (53.6%) and phenotypic differences from phylogenetically related Micromonospora species indicated that this isolate belongs to a novel species, for which the name Micromonospora rifamycinica sp. nov. is proposed. The type strain is AM105(T) (=CGMCC 4.2495(T)=DSM 44983(T)).

  7. Effect of oxidative stress on the biosynthesis of 2-C-methyl-D-erythritol-2,4-cyclopyrophosphate and isoprenoids by several bacterial strains.

    PubMed

    Ostrovsky, D; Diomina, G; Lysak, E; Matveeva, E; Ogrel, O; Trutko, S

    1998-12-01

    In this study, the gram-negative bacteria Xanthomonas campestris, Xanthomonas maltophilia, and Pseudomonas putida, facultative parasites of plants and animals, were shown to accumulate 2-C-methyl-d-erythritol-2,4-cyclopyrophosphate (MEC) in response to benzyl-viologen-induced oxidative stress. Corynebacterium ammoniagenes mutants capable of accumulating MEC in the absence of an exogenous oxidative stress inducer were obtained. Isoprenoid synthesis and MEC synthesis in these and other bacteria were shown to be alternative processes, while biosynthesis of brominated polyene xanthomonadin (an antioxidant pigment of X. campestris) increased concomitantly with the accumulation of MEC.

  8. In vitro activities of enoxacin, ticarcillin plus clavulanic acid, aztreonam, piperacillin, and imipenem and comparison with commonly used antimicrobial agents.

    PubMed Central

    Henry, D; Skidmore, A G; Ngui-Yen, J; Smith, A; Smith, J A

    1985-01-01

    A total of 745 gram-negative and 313 gram-positive clinical isolates were tested against enoxacin, ticarcillin plus clavulanic acid, aztreonam, imipenem, and piperacillin and compared with commonly used antimicrobial agents. Ticarcillin plus clavulanic acid, imipenem, and piperacillin were active against Pseudomonas aeruginosa and Acinetobacter spp. and most Pseudomonas spp. Aztreonam was active against members of the family Enterobacteriaceae but was less effective against the nonfermenters. Enoxacin was active against the Enterobacteriaceae, P. aeruginosa, the staphylococci, and most Acinetobacter spp. but was less active against Pseudomonas spp. and streptococci. Imipenem was very active against all gram-positive and -negative organisms tested except for Pseudomonas maltophilia. PMID:3869433

  9. Preparation, characterization, and antifungal activity of hymexazol-linked chitosan derivatives

    NASA Astrophysics Data System (ADS)

    Li, Yan; Qin, Yukun; Liu, Song; Li, Pengcheng; Xing, Rong'e.

    2016-09-01

    In this study, three hymexazol-linked chitosan derivatives (HML-CS) were synthesized and their structures confirmed by Fourier transform infrared and elemental analysis. Linkage ratios were measured by high performance liquid chromatography. The derivatives' antifungal activity against the plant pathogenic fungi Rhizoctonia solani CGMCC 3.28 and Gibberella zeae CGMCC 3.42 were investigated at concentrations of 100, 200, and 400 mg/L. These HML-CS derivatives exhibited stronger antifungal activity than CS alone. HML-CS-1 showed the best antifungal activity against G. zeae, whose antifungal index was 65.9% at 400 mg/L, and also showed the best antifungal activity against R. solani, whose antifungal index was 52.7% at 400 mg/L. This conjugation of CS and HML suggested the presence of synergistic effects between the moieties and indicated that these derivatives possessed great potential as novel fungicides and require further research for the development of applications in crop protection.

  10. Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

    2015-12-01

    Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains.

  11. 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

  12. Streptomyces chlorus sp. nov. and Streptomyces viridis sp. nov., isolated from soil.

    PubMed

    Kim, Byung-Yong; Rong, Xiaoying; Zucchi, Tiago D; Huang, Ying; Goodfellow, Michael

    2013-05-01

    Two actinomycete strains, BK125(T) and BK199(T), isolated from a hay meadow soil sample were investigated to determine their taxonomic position using a polyphasic approach. The isolates produced greenish-yellow and light green aerial mycelium on oatmeal agar, respectively. They contained anteiso-C15 : 0, iso-C15 : 0 and C16 : 0 as the major fatty acids, and MK-9 (H6) and MK-9 (H8) as the predominant isoprenoid quinones. Phylogenetic analysis of the 16S rRNA gene sequences showed that the isolates formed distinct phyletic lines towards the periphery of the Streptomyces prasinus subclade. Analysis of DNA-DNA relatedness between the two isolates showed that they belonged to different genomic species. The organisms were also distinguished from one another and from type strains of species classified in the S. prasinus subclade using a combination of genotypic and phenotypic properties. On the basis of these data, it is proposed that the isolates be assigned to the genus Streptomyces as Streptomyces chlorus sp. nov. and Streptomyces viridis sp. nov. with isolates BK125(T) ( = KACC 20902(T) = CGMCC 4.5798(T)) and BK199(T) ( = KACC 21003(T) = CGMCC 4.6824(T)) as the respective type strains. PMID:22922536

  13. 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.

  14. Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics.

    PubMed

    Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

    2015-12-22

    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.

  15. An Alternative Approach to Synthesizing Galactooligosaccharides by Cell-Surface Display of β-Galactosidase on Yarrowia lipolytica.

    PubMed

    An, Jin; Zhang, Lebin; Li, Lijuan; Liu, Dawen; Cheng, Huiling; Wang, Hengwei; Nawaz, Muhammad Zohaib; Cheng, Hairong; Deng, Zixin

    2016-05-18

    An alternative strategy for synthesizing galactooligosaccharides (GOS) from an erythritol-producing yeast Yarrowia lipolytica using surface display technology was demonstrated. The engineered strain CGMCC11369 was developed by fusion of the β-galactosidase gene from Aspergillus oryzae to the YlPir1 gene, which codes for a cell wall protein. β-Galactosidase was effectively displayed on the cell surface of Yarrowia lipolytica start strain CGMCC7326. This engineered strain with surface-displayed β-galactosidase efficiently synthesized GOS from lactose. An amount of 160 g/L GOS was produced within 6 h in a solution of 500 g/L lactose and 5 mg/mL cell (dry weight) at pH 5.5 and 60 °C, with a yield of 51% of consumed lactose monohydrate. This newly developed method was applied with waste yeast paste from erythritol industry at least 10 times. The optimal reaction temperature increased to 60 °C, about 20 °C higher than that of free β-galactosidase, which was helpful for enhancing the reaction rate and GOS production. PMID:27090877

  16. Streptomyces erringtonii sp. nov. and Streptomyces kaempferi sp. nov., isolated from a hay meadow soil.

    PubMed

    Santhanam, Rakesh; Rong, Xiaoying; Huang, Ying; Goodfellow, Michael

    2013-01-01

    Two filamentous actinomycetes isolated from a hay meadow soil were provisionally assigned to the genus Streptomyces based on morphological features. The isolates were found to have chemical and morphological properties typical of the genus Streptomyces and formed distinct phyletic lines in the 16S rRNA gene tree. Isolate I36(T) was most closely related to Streptomyces glauciniger NBRC 100913(T) and isolate I37(T) to Streptomyces mirabilis NBRC 13450(T). Low DNA:DNA relatedness values were recorded between each of the isolates and their closest phylogenetic neighbour. The isolates were also distinguished from their nearest phylogenetic neighbour, and from one another, using a combination of phenotypic properties. These data indicate that the isolates should be recognised as new species in the genus Streptomyces. The names proposed for these new taxa are Streptomyces erringtonii sp. nov. and Streptomyces kaempferi sp. nov. with isolate I36(T) (=CGMCC 4.7016(T) = KACC 15424(T)) and isolate I37(T) (=CGMCC 4.7020(T) = KACC 15428(T)) as the respective type strains.

  17. Highly efficient production of D-lactic acid from chicory-derived inulin by Lactobacillus bulgaricus.

    PubMed

    Xu, Qianqian; Zang, Ying; Zhou, Jie; Liu, Peng; Li, Xin; Yong, Qiang; Ouyang, Jia

    2016-11-01

    Inulin is a readily available feedstock for cost-effective production of biochemicals. To date, several studies have explored the production of bioethanol, high-fructose syrup and fructooligosaccharide, but there are no studies regarding the production of D-lactic acid using inulin as a carbon source. In the present study, chicory-derived inulin was used for D-lactic acid biosynthesis by Lactobacillus bulgaricus CGMCC 1.6970. Compared with separate hydrolysis and fermentation processes, simultaneous saccharification and fermentation (SSF) has demonstrated the best performance of D-lactic acid production. Because it prevents fructose inhibition and promotes the complete hydrolysis of inulin, the highest D-lactic acid concentration (123.6 ± 0.9 g/L) with a yield of 97.9 % was obtained from 120 g/L inulin by SSF. Moreover, SSF by L. bulgaricus CGMCC 1.6970 offered another distinct advantage with respect to the higher optical purity of D-lactic acid (>99.9 %) and reduced number of residual sugars. The excellent performance of D-lactic acid production from inulin by SSF represents a high-yield method for D-lactic acid production from non-food grains.

  18. 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

  19. Highly efficient production of D-lactic acid from chicory-derived inulin by Lactobacillus bulgaricus.

    PubMed

    Xu, Qianqian; Zang, Ying; Zhou, Jie; Liu, Peng; Li, Xin; Yong, Qiang; Ouyang, Jia

    2016-11-01

    Inulin is a readily available feedstock for cost-effective production of biochemicals. To date, several studies have explored the production of bioethanol, high-fructose syrup and fructooligosaccharide, but there are no studies regarding the production of D-lactic acid using inulin as a carbon source. In the present study, chicory-derived inulin was used for D-lactic acid biosynthesis by Lactobacillus bulgaricus CGMCC 1.6970. Compared with separate hydrolysis and fermentation processes, simultaneous saccharification and fermentation (SSF) has demonstrated the best performance of D-lactic acid production. Because it prevents fructose inhibition and promotes the complete hydrolysis of inulin, the highest D-lactic acid concentration (123.6 ± 0.9 g/L) with a yield of 97.9 % was obtained from 120 g/L inulin by SSF. Moreover, SSF by L. bulgaricus CGMCC 1.6970 offered another distinct advantage with respect to the higher optical purity of D-lactic acid (>99.9 %) and reduced number of residual sugars. The excellent performance of D-lactic acid production from inulin by SSF represents a high-yield method for D-lactic acid production from non-food grains. PMID:27440161

  20. An Alternative Approach to Synthesizing Galactooligosaccharides by Cell-Surface Display of β-Galactosidase on Yarrowia lipolytica.

    PubMed

    An, Jin; Zhang, Lebin; Li, Lijuan; Liu, Dawen; Cheng, Huiling; Wang, Hengwei; Nawaz, Muhammad Zohaib; Cheng, Hairong; Deng, Zixin

    2016-05-18

    An alternative strategy for synthesizing galactooligosaccharides (GOS) from an erythritol-producing yeast Yarrowia lipolytica using surface display technology was demonstrated. The engineered strain CGMCC11369 was developed by fusion of the β-galactosidase gene from Aspergillus oryzae to the YlPir1 gene, which codes for a cell wall protein. β-Galactosidase was effectively displayed on the cell surface of Yarrowia lipolytica start strain CGMCC7326. This engineered strain with surface-displayed β-galactosidase efficiently synthesized GOS from lactose. An amount of 160 g/L GOS was produced within 6 h in a solution of 500 g/L lactose and 5 mg/mL cell (dry weight) at pH 5.5 and 60 °C, with a yield of 51% of consumed lactose monohydrate. This newly developed method was applied with waste yeast paste from erythritol industry at least 10 times. The optimal reaction temperature increased to 60 °C, about 20 °C higher than that of free β-galactosidase, which was helpful for enhancing the reaction rate and GOS production.

  1. 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.

  2. Chemical transformation of toxic metals by a Psuedomonas strain from a toxic waste site

    SciTech Connect

    Choate, D.; Blake, R.; Revis, N. Oak Ridge Research Inst., TN )

    1991-03-11

    Pseudomonas maltophilia, 0-2, isolated from soil at a toxic waste site in Oak Ridge, TN, catalyzed the transformation and precipitation of numerous toxic metal cations and oxyanions. When a viable inoculum (1%) of 0-2 was introduced into LB broth containing 0.2 mM Hg(II), 1 mM Cr(VI), 40 mM Se(IV), 3 mM Pb(II), 3mM Au(III), 3mM Cd(II), 10mM Te(IV), or 4mM Ag(I), effective removal of the toxic metal was complete within 1, 1, 2, 2, 2, 4, 5, and 7 days, respectively. The NADPH-dependent reduction of Hg(II) was catalyzed by an inducible mercuric reductase. The reduction of selenite and tellurite to their insoluble elemental forms appeared to be mediated by an intracellular glutathione reductase that utilized the spontaneously-formed bis(glutathio)Se or bis(glutathio)Te, respectively, as pseudosubstrates. The biomolecules responsible for the remaining metal transformations are currently under investigation. This project could provide useful information toward the eventual exploitation of P. maltophilia and related organisms for the removal of toxic metal wastes from selected, heavily polluted sites.

  3. Characterization of copper-resistant bacteria and bacterial communities from copper-polluted agricultural soils of central Chile

    PubMed Central

    2012-01-01

    Background Copper mining has led to Cu pollution in agricultural soils. In this report, the effects of Cu pollution on bacterial communities of agricultural soils from Valparaiso region, central Chile, were studied. Denaturing gradient gel electrophoresis (DGGE) of the 16S rRNA genes was used for the characterization of bacterial communities from Cu-polluted and non-polluted soils. Cu-resistant bacterial strains were isolated from Cu-polluted soils and characterized. Results DGGE showed a similar high number of bands and banding pattern of the bacterial communities from Cu-polluted and non-polluted soils. The presence of copA genes encoding the multi-copper oxidase that confers Cu-resistance in bacteria was detected by PCR in metagenomic DNA from the three Cu-polluted soils, but not in the non-polluted soil. The number of Cu-tolerant heterotrophic cultivable bacteria was significantly higher in Cu-polluted soils than in the non-polluted soil. Ninety two Cu-resistant bacterial strains were isolated from three Cu-polluted agricultural soils. Five isolated strains showed high resistance to copper (MIC ranged from 3.1 to 4.7 mM) and also resistance to other heavy metals. 16S rRNA gene sequence analyses indicate that these isolates belong to the genera Sphingomonas, Stenotrophomonas and Arthrobacter. The Sphingomonas sp. strains O12, A32 and A55 and Stenotrophomonas sp. C21 possess plasmids containing the Cu-resistance copA genes. Arthrobacter sp. O4 possesses the copA gene, but plasmids were not detected in this strain. The amino acid sequences of CopA from Sphingomonas isolates (O12, A32 and A55), Stenotrophomonas strain (C21) and Arthrobacter strain (O4) are closely related to CopA from Sphingomonas, Stenotrophomonas and Arthrobacter strains, respectively. Conclusions This study suggests that bacterial communities of agricultural soils from central Chile exposed to long-term Cu-pollution have been adapted by acquiring Cu genetic determinants. Five bacterial isolates

  4. Pseudomonas guangdongensis sp. nov., isolated from an electroactive biofilm, and emended description of the genus Pseudomonas Migula 1894.

    PubMed

    Yang, Guiqin; Han, Luchao; Wen, Junlin; Zhou, Shungui

    2013-12-01

    A Gram-negative, straight to slightly curved rod-shaped bacterium, motile with peritrichous flagella, designated SgZ-6(T), was isolated from an electroactive biofilm and was characterized by means of a polyphasic approach. Growth occurred with 0-5.0 % (w/v) NaCl (optimum 1 %), at pH 6.0-10.0 (optimum pH 7.0) and at 10-42 °C (optimum 30 °C) in trypticase soya broth. Phylogenetic analyses based on the 16S rRNA and gyrB genes identified the isolate as a member of a novel species of the genus Pseudomonas. Strain SgZ-6(T) exhibited the highest 16S rRNA gene sequence similarity to 'Pseudomonas linyingensis' CGMCC 1.10701 (97.5 %), followed by Pseudomonas sagittaria JCM 18195(T) (97.4 %), P. oleovorans subsp. lubricantis DSM 21016(T) (96.6 %), P. tuomuerensis JCM 14085(T) (96.5 %) and P. alcaliphila JCM 10630(T) (96.4 %). Strain SgZ-6(T) showed the highest gyrB gene sequence similarity of 93.7 % to 'P. linyingensis' CGMCC 1.10701 among all type strains of genus Pseudomonas. DNA-DNA pairing studies showed that strain SgZ-6(T) displayed 47.1 and 40.3 % relatedness to 'P. linyingensis' CGMCC 1.10701 and P. sagittaria JCM 18195(T), respectively. The major isoprenoid quinone was ubiquinone 9 (Q-9). The whole-cell fatty acids consisted mainly of summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), C16 : 0 and summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c). The DNA G+C content of the genomic DNA was 68.1 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain SgZ-6(T) is proposed to represent a novel species of the genus Pseudomonas, for which the name Pseudomonas guangdongensis sp. nov. is proposed. The type strain is SgZ-6(T) ( = CCTCC AB 2012022(T) = KACC 16606(T)). An emended description of the genus Pseudomonas is also proposed. PMID:23918787

  5. Regulation of aromatics biodegradation by rhl quorum sensing system through induction of catechol meta-cleavage pathway.

    PubMed

    Yong, Yang-Chun; Zhong, Jian-Jiang

    2013-05-01

    The mechanism for quorum sensing (QS) regulation on aromatics degradation was investigated. Deletion of rhl QS system resulted in a significant decrease in aromatics biodegradation as well as the activity of catechol 2,3-dioxygenase (C23O, key enzyme for catechol meta-cleavage pathway) in Pseudomonas aeruginosa CGMCC1.860. Interestingly, this repression could be relieved by N-butyryl homoserine lactone (the signaling molecule of rhl QS system) addition. In accordance, the transcription level of nahH (the gene encoding C23O) and nahR (transcriptional activator) also responded to rhl perturbation in a similar way. The results indicated that rhl QS system positively controlled the catechol meta-cleavage pathway, and hence improved aromatics biodegradation. It suggested manipulation of QS system could be a promising strategy to tune the catechol cleavage pathway and to control aromatics biodegradation.

  6. Complete genome sequence of Streptococcus thermophilus MN-BM-A01, a strain with high exopolysaccharides production.

    PubMed

    Bai, Ying; Sun, Erna; Shi, Yudong; Jiang, Yunyun; Chen, Yun; Liu, Songling; Zhao, Liang; Zhang, Ming; Guo, Huiyuan; Zhang, Hao; Mu, Zhishen; Ren, Fazheng

    2016-04-20

    Streptococcus thermophilus MN-BM-A01 (ST MN-BM-A01) (CGMCC No. 11383) was a strain isolated from Yogurt Block in Gansu, China. The yogurt fermented with this strain has good flavor, acidity, and viscosity. Moreover, ST MN-BM-A01 could produce a high level of EPS which can confer the yogurt with improved rheological properties. We reported the complete genome sequence of ST MN-BM-A01 that contains 1,876,516bp encoding 1704 coding sequences (CDSs), 67 tRNA genes and 6 rRNA operons. The genomic sequence indicated that this strain included a 35.3-kb gene cluster involved in EPS biosynthesis. PMID:26956372

  7. 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.

  8. Complete genome sequence of Kosakonia sacchari type strain SP1T

    PubMed Central

    Chen, Mingyue; Zhu, Bo; Lin, Li; Yang, Litao; Li, Yangrui; An, Qianli

    2014-01-01

    Kosakonia sacchari sp. nov. is a new species within the new genus Kosakonia, which was included in the genus Enterobacter. K sacchari is a nitrogen-fixing bacterium named for its association with sugarcane (Saccharum officinarum L.). K sacchari bacteria are Gram-negative, aerobic, non-spore-forming, motile rods. Strain SP1T (=CGMCC1.12102T=LMG 26783T) is the type strain of the K sacchari sp. nov and is able to colonize and fix N2 in association with sugarcane plants, thus promoting plant growth. Here we summarize the features of strain SP1T and describe its complete genome sequence. The genome contains a single chromosome and no plasmids, 4,902,024 nucleotides with 53.7% GC content, 4,460 protein-coding genes and 105 RNA genes including 22 rRNA genes, 82 tRNA genes, and 1 ncRNA gene. PMID:25197499

  9. 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.

  10. 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

  11. Evaluation of the formation of volatiles and sensory characteristics of persimmon (Diospyros kaki L.f.) fruit wines using different commercial yeast strains of Saccharomyces cerevisiae.

    PubMed

    Zhu, Jian Cai; Niu, Yun Wei; Feng, Tao; Liu, Sheng Jiang; Cheng, He Xing; Xu, Na; Yu, Hai Yan; Xiao, Zuo Bing

    2014-01-01

    This study evaluated the effects of five strains (IFFI 1346, IFFI 1363, CICC 31482, D254 and CGMCC2.346) of the yeast Saccharomyces cerevisiae on the aromatic profiles of fermented persimmon (Diospyros kaki L.f.) musts. A total of 50 and 60 compounds were identified in persimmon wine by stir bar sorptive extraction coupled with gas chromatography-mass spectrometry. According to odour activity values (OAVs), 26 detected compounds showed an OAV above 1. Principal component analysis explained the distribution of these persimmon wines on the basis of volatile compounds with OAV>1. The volatile compounds with high OAV included ethyl hexanoate, ethyl octanoate, methyl decanoate, linalool and geraniol. Quantitative descriptive analysis was employed. The result showed that persimmon wines fermented with strains IFFI 1363 and D254 were strongly correlated with persimmon, aroma harmony, fruity, fusel and taste balanced, fullness, hedonic scale. Therefore, the two yeast strains could be used as starter culture for persimmon wine production.

  12. Kwoniella shandongensis sp. nov., a basidiomycetous yeast isolated from soil and bark from an apple orchard.

    PubMed

    Chen, Ru; Jiang, Yuan-Mao; Wei, Shao-Chong; Wang, Qi-Ming

    2012-11-01

    Four basidiomycetous yeast strains (Y13-1(T), Y2-1, Y6-3 and Y8-2) were isolated from soil and bark collected from an apple orchard in Tai'an, Shandong province, PR China. Phylogenetic analysis based on 26S rRNA gene D1/D2 domains and ITS regions revealed that these novel strains were located in the Kwoniella clade in the class Tremellomycetes and were closely related to Cryptococcus cuniculi and Kwoniella heveanensis, but were clearly distinct from these species. Therefore, it is proposed that the new strains represent a novel species, Kwoniella shandongensis sp. nov., with the type strain Y13-1(T)(=CGMCC 2.04458(T)=CBS 12478(T)). The MycoBank number for the novel species is MB 564868.

  13. Oceanicola nitratireducens sp. nov., a marine alphaproteobacterium isolated from the South China Sea.

    PubMed

    Zheng, Qiang; Chen, Chuang; Wang, Ya-Nan; Jiao, Nianzhi

    2010-07-01

    A Gram-negative, non-motile, short-rod-shaped bacterial strain (JLT1210(T)) that accumulates poly-beta-hydroxybutyrate granules was isolated from the Beibu Gulf in the South China Sea. Cells have polar or subpolar flagella. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain belongs to the genus Oceanicola in the order Rhodobacterales, class Alphaproteobacteria. The closest neighbours were Oceanicola nanhaiensis SS011B1-20(T) (96.5 % similarity) and Oceanicola batsensis HTCC2597(T) (96.4 %). The predominant respiratory ubiquinone of strain JLT1210(T) was Q-10 and the DNA G+C content was 72.8 mol%. Evidence from genotypic, chemotaxonomic and phenotypic data shows that strain JLT1210(T) represents a novel species of the genus Oceanicola, for which the name Oceanicola nitratireducens sp. nov. is proposed; the type strain is JLT1210(T) (=LMG 24663(T)=CGMCC 1.7292(T)).

  14. Fabivirga thermotolerans gen. nov., sp. nov., a novel marine bacterium isolated from culture broth of a marine cyanobacterium.

    PubMed

    Tang, M; Chen, C; Li, J; Xiang, W; Wu, H; Wu, J; Dai, S; Wu, H; Li, T; Wang, G

    2016-02-01

    A Gram-stain-negative, red, non-spore-forming, strictly aerobic bacterium, designated strain A4T, was isolated from culture broth of a marine cyanobacterium. Cells were flexible rods with gliding motility. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain A4T formed a coherent cluster with members of the genera Roseivirga and Fabibacter, and represents a distinct lineage in the family Flammeovirgaceae. Thermotolerance and a distinctive cellular fatty acid profile could readily distinguish this isolate from any bacteria of the genera Roseivirga and Fabibacter with a validly published name. On the basis of the phenotypic, chemotaxonomic and phylogenetic characteristics, strain A4T is suggested to represent a novel species in a novel genus, for which the name Fabivirga thermotolerans gen. nov., sp. nov. is proposed. The type strain is A4T ( = KCTC 42507T = CGMCC 1.15111T).

  15. Diversity, metal resistance and uranium sequestration abilities of bacteria from uranium ore deposit in deep earth stratum.

    PubMed

    Islam, Ekramul; Sar, Pinaki

    2016-05-01

    Metal resistance and uranium (U) sequestration abilities of bacteria residing in subsurface U ore was investigated using 122 pure culture strains isolated through enrichment. The cumulative frequencies of isolates resistant to each metal tested were as follows: As(V), 74%; Zn, 58%; Ni, 53%; Cd, 47%; Cr(VI), 41%; Co, 40%; Cu, 20%; and Hg, 4%. 16S rRNA gene analysis revealed that isolated bacteria belonged to 14 genera with abundance of Arthrobacter, Microbacterium, Acinetobacter and Stenotrophomonas. Cobalt did not interfere with the growth of most of the bacterial isolates belonging to different groups while U allowed growth of four different genera of which Stenotrophomonas and Microbacterium showed high U tolerance. Interestingly, tolerance to Ni, Zn, Cu, and Hg was observed only in Microbacterium, Arthrobacter, Paenibacillus¸ and Acinetobacter, respectively. However, Microbacterium was found to be dominant when isolated from other five different metal enrichments including U. Uranium removal study showed that 84% of the test bacteria could remove more than 50mgUg(-1) dry weight from 80 or 160mgL(-1) U within 48h. In general, Microbacterium, Arthrobacter and Acinetobacter could remove a higher amount of U. High resolution transmission electron microscopy (HRTEM) study of U exposed cells revealed that accumulated U sequestered mostly around the cell periphery. The study highlights that indigenous U ore deposit bacteria have the potential to interact with U, and thus could be applied for bioremediation of U contaminated sites or wastes.

  16. Diversity, metal resistance and uranium sequestration abilities of bacteria from uranium ore deposit in deep earth stratum.

    PubMed

    Islam, Ekramul; Sar, Pinaki

    2016-05-01

    Metal resistance and uranium (U) sequestration abilities of bacteria residing in subsurface U ore was investigated using 122 pure culture strains isolated through enrichment. The cumulative frequencies of isolates resistant to each metal tested were as follows: As(V), 74%; Zn, 58%; Ni, 53%; Cd, 47%; Cr(VI), 41%; Co, 40%; Cu, 20%; and Hg, 4%. 16S rRNA gene analysis revealed that isolated bacteria belonged to 14 genera with abundance of Arthrobacter, Microbacterium, Acinetobacter and Stenotrophomonas. Cobalt did not interfere with the growth of most of the bacterial isolates belonging to different groups while U allowed growth of four different genera of which Stenotrophomonas and Microbacterium showed high U tolerance. Interestingly, tolerance to Ni, Zn, Cu, and Hg was observed only in Microbacterium, Arthrobacter, Paenibacillus¸ and Acinetobacter, respectively. However, Microbacterium was found to be dominant when isolated from other five different metal enrichments including U. Uranium removal study showed that 84% of the test bacteria could remove more than 50mgUg(-1) dry weight from 80 or 160mgL(-1) U within 48h. In general, Microbacterium, Arthrobacter and Acinetobacter could remove a higher amount of U. High resolution transmission electron microscopy (HRTEM) study of U exposed cells revealed that accumulated U sequestered mostly around the cell periphery. The study highlights that indigenous U ore deposit bacteria have the potential to interact with U, and thus could be applied for bioremediation of U contaminated sites or wastes. PMID:26796528

  17. Biodegradation of geosmin in drinking water by novel bacteria isolated from biologically active carbon.

    PubMed

    Zhou, Beihai; Yuan, Rongfang; Shi, Chunhong; Yu, Liying; Gu, Junnong; Zhang, Chunlei

    2011-01-01

    Three strains of Gram-negative bacteria capable of removing geosmin from drinking water were isolated from biologically active carbon and identified to be Chryseobacterium sp., Sinorhizobium sp. and Stenotrophomonas sp. based on physio-biochemistry analysis and 16S rRNA gene sequence analysis. Removal efficiencies of 2 mg/L geosmin in mineral salts medium were 84.0%, 80.2% and 74.4% for Chryseobacterium sp., Sinorhizobium sp. and Stenotrophomonas sp., respectively, while removal efficiencies of 560 ng/L geosmin in filter influent were 84.8%, 82.3% and 82.5%, respectively. The biodegradation of geosmin was determined to be a pseudo first-order reaction, with rate constants at 2 mg/L and 560 ng/L being 0.097 and 0.086 day(-1), 0.089 and 0.084 day(-1), 0.074 and 0.098 day(-1) for the above mentioned degraders, respectively. The biomass of culture in the presence of geosmin was much higher than that in the absence of geosmin.

  18. Nonylphenol biodegradation, functional gene abundance and bacterial community in bioaugmented sediment: effect of external carbon source.

    PubMed

    Wang, Zhao; Dai, Yu; Zhao, Qun; Li, Ningning; Zhou, Qiheng; Xie, Shuguang

    2015-08-01

    Nonylphenol (NP) biodegradation in river sediment using Stenotrophomonas strain Y1 and Sphingobium strain Y2 were proved to be an effective strategy to remediate NP pollution in our earlier study. The purpose of this study is to investigate the influence of glucose addition on their ability to degrade NP in both liquid cultures and sediment microcosms. The shift in bacterial community structure and relative abundance of NP degraders in sediment microcosms were characterized using terminal restriction fragment length polymorphism analysis. The proportion of NP-degrading alkB and sMO genes was assessed using quantitative polymerase chain reaction (PCR) assay. The growth of Stenotrophomonas strain Y1 and its NP biodegradation efficiency were inhibited by glucose supplementation, while the relative abundance of alkB gene increased. However, NP degradation, as well as the growth of added degraders and proportion of sMO gene, was enhanced in the glucose-amended sediment microcosms inoculated with Sphingobium strain Y2. Moreover, external glucose addition altered bacterial community structures in bioaugmented sediment microcosms, depending on the level of glucose dosage.

  19. 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

  20. Streptosporangium jiaoheense sp. nov. and Streptosporangium taraxaci sp. nov., actinobacteria isolated from soil and dandelion root (Taraxacum mongolicum Hand.-Mazz.).

    PubMed

    Zhao, Junwei; Guo, Lifeng; Li, Zhilei; Piao, Chenyu; Li, Yao; Li, Jiansong; Liu, Chongxi; Wang, Xiangjing; Xiang, Wensheng

    2016-06-01

    Two novel actinobacteria, designated strains NEAU-Jh1-4T and NEAU-Wp2-0T, were isolated from muddy soil collected from a riverbank in Jiaohe and a dandelion root collected from Harbin, respectively. A polyphasic study was carried out to establish the taxonomic positions of these two strains. The phylogenetic analysis based on the 16S rRNA gene sequences of strains NEAU-Jh1-4T and NEAU-Wp2-0T indicated that strain NEAU-Jh1-4T clustered with Streptosporangium nanhuense NEAU-NH11T (99.32 % 16S rRNA gene sequence similarity), Streptosporangium purpuratum CY-15110T (98.30 %) and Streptosporangium yunnanense CY-11007T (97.95 %) and strain NEAU-Wp2-0T clustered with 'Streptosporangium sonchi  ' NEAU-QS7 (99.39 %), 'Streptosporangium kronopolitis' NEAU-ML10 (99.26 %), 'Streptosporangium shengliense' NEAU-GH7 (98.85 %) and Streptosporangium longisporum DSM 43180T (98.69 %). Moreover, morphological and chemotaxonomic properties of the two isolates also confirmed their affiliation to the genus Streptosporangium. However, the low level of DNA-DNA hybridization and some phenotypic characteristics allowed the isolates to be differentiated from the most closely related species. Therefore, it is proposed that strains NEAU-Jh1-4T and NEAU-Wp2-0T represent two novel species of the genus Streptosporangium, for which the name Streptosporangium jiaoheense sp. nov. and Streptosporangium taraxaci sp. nov. are proposed. The type strains are NEAU-Jh1-4T (=CGMCC 4.7213T=JCM 30348T) and NEAU-Wp2-0T (=CGMCC 4.7217T=JCM 30349T), respectively. PMID:27031531

  1. Phylogenomic analysis shows that ‘Bacillus vanillea’ is a later heterotypic synonym of Bacillus siamensis.

    PubMed

    Dunlap, Christopher A

    2015-10-01

    ‘Bacillus vanillea’ XY18 ( = CGMCC 8629 = NCCB 100507) was isolated from cured vanilla beans and involved in the formation of vanilla aroma compounds. A draft genome of this strain was assembled and yielded a length of 3.71 Mbp with a DNA G+C content of 46.3 mol%. Comparative genomic analysis with its nearest relatives showed only minor differences between this strain and the genome of the Bacillus siamensis KCTC 13613T ( = BCC 22614T = KACC 16244T), with a calculated DNA–DNA hybridization (DDH) value of 91.2 % and an average nucleotide identity (ANI) of 98.9 %. This DDH value is well above the recommended 70 % threshold for species delineation, as well as the ANI threshold of 95 %. In addition, the results of morphological, physiological, chemotaxonomic and phylogenetic analyses indicate that the type strains of these two taxa are highly similar with phenotype coherence. A core genome multi-locus sequencing analysis was conducted for the strains and the results show that ‘Bacillus vanillea’ XY18 clusters closely to the type strain of Bacillus siamensis. Therefore, it is proposed that the species ‘Bacillus vanillea’ XY18 ( = CGMCC 8629 = NCCB 100507) should be reclassified as a later heterotypic synonym of Bacillus siamensis KCTC 13613T ( = BCC 22614T = KACC 16244T). An emended description of Bacillus siamensis is provided. PMID:26296875

  2. Phylogenomic analysis shows that ‘Bacillus vanillea’ is a later heterotypic synonym of Bacillus siamensis.

    PubMed

    Dunlap, Christopher A

    2015-10-01

    ‘Bacillus vanillea’ XY18 ( = CGMCC 8629 = NCCB 100507) was isolated from cured vanilla beans and involved in the formation of vanilla aroma compounds. A draft genome of this strain was assembled and yielded a length of 3.71 Mbp with a DNA G+C content of 46.3 mol%. Comparative genomic analysis with its nearest relatives showed only minor differences between this strain and the genome of the Bacillus siamensis KCTC 13613T ( = BCC 22614T = KACC 16244T), with a calculated DNA–DNA hybridization (DDH) value of 91.2 % and an average nucleotide identity (ANI) of 98.9 %. This DDH value is well above the recommended 70 % threshold for species delineation, as well as the ANI threshold of 95 %. In addition, the results of morphological, physiological, chemotaxonomic and phylogenetic analyses indicate that the type strains of these two taxa are highly similar with phenotype coherence. A core genome multi-locus sequencing analysis was conducted for the strains and the results show that ‘Bacillus vanillea’ XY18 clusters closely to the type strain of Bacillus siamensis. Therefore, it is proposed that the species ‘Bacillus vanillea’ XY18 ( = CGMCC 8629 = NCCB 100507) should be reclassified as a later heterotypic synonym of Bacillus siamensis KCTC 13613T ( = BCC 22614T = KACC 16244T). An emended description of Bacillus siamensis is provided.

  3. Halorussus amylolyticus sp. nov., isolated from an inland salt lake.

    PubMed

    Yuan, Pan-Pan; Ye, Wei-Tao; Pan, Jia-Xiang; Han, Dong; Zhang, Wen-Jiao; Cui, Heng-Lin

    2015-10-01

    A halophilic archaeal strain, YC93T, was isolated from Yuncheng salt lake in Shanxi Province, China. Cells were pleomorphic rods, stained Gram-negative and formed light-red-pigmented colonies on agar plates. Strain YC93T was able to grow at 25–50 °C (optimum 37 °C), with 1.4–4.8 M NaCl (optimum 2.0 M), with 0–1.0 M MgCl2 (optimum 0.05 M) and at pH 6.0–9.5 (optimum pH 7.0). Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8 % (w/v). 16S rRNA gene sequence analysis revealed that strain YC93T had two dissimilar 16S rRNA genes both of which were phylogenetically related to those of the two recognized members of the genus Halorussus (93.0–95.3 % similarity). The rpoB′ gene of strain YC93T was phylogenetically related to the corresponding gene of Halorussus rarus TBN4T (91.3 % similarity) and Halorussus ruber YC25T (90.5 %). The major polar lipids were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and five glycolipids chromatographically identical to those of Halorussus rarus CGMCC 1.10122T. The DNA G+C content of strain YC93T was 64.6 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YC93T represents a novel species of the genus Halorussus, for which the name Halorussus amylolyticus sp. nov. is proposed. The type strain is YC93T ( = CGMCC 1.12126T = JCM 18367T). PMID:26228463

  4. Streptosporangium jiaoheense sp. nov. and Streptosporangium taraxaci sp. nov., actinobacteria isolated from soil and dandelion root (Taraxacum mongolicum Hand.-Mazz.).

    PubMed

    Zhao, Junwei; Guo, Lifeng; Li, Zhilei; Piao, Chenyu; Li, Yao; Li, Jiansong; Liu, Chongxi; Wang, Xiangjing; Xiang, Wensheng

    2016-06-01

    Two novel actinobacteria, designated strains NEAU-Jh1-4T and NEAU-Wp2-0T, were isolated from muddy soil collected from a riverbank in Jiaohe and a dandelion root collected from Harbin, respectively. A polyphasic study was carried out to establish the taxonomic positions of these two strains. The phylogenetic analysis based on the 16S rRNA gene sequences of strains NEAU-Jh1-4T and NEAU-Wp2-0T indicated that strain NEAU-Jh1-4T clustered with Streptosporangium nanhuense NEAU-NH11T (99.32 % 16S rRNA gene sequence similarity), Streptosporangium purpuratum CY-15110T (98.30 %) and Streptosporangium yunnanense CY-11007T (97.95 %) and strain NEAU-Wp2-0T clustered with 'Streptosporangium sonchi  ' NEAU-QS7 (99.39 %), 'Streptosporangium kronopolitis' NEAU-ML10 (99.26 %), 'Streptosporangium shengliense' NEAU-GH7 (98.85 %) and Streptosporangium longisporum DSM 43180T (98.69 %). Moreover, morphological and chemotaxonomic properties of the two isolates also confirmed their affiliation to the genus Streptosporangium. However, the low level of DNA-DNA hybridization and some phenotypic characteristics allowed the isolates to be differentiated from the most closely related species. Therefore, it is proposed that strains NEAU-Jh1-4T and NEAU-Wp2-0T represent two novel species of the genus Streptosporangium, for which the name Streptosporangium jiaoheense sp. nov. and Streptosporangium taraxaci sp. nov. are proposed. The type strains are NEAU-Jh1-4T (=CGMCC 4.7213T=JCM 30348T) and NEAU-Wp2-0T (=CGMCC 4.7217T=JCM 30349T), respectively.

  5. Devosia psychrophila sp. nov. and Devosia glacialis sp. nov., from alpine glacier cryoconite, and an emended description of the genus Devosia.

    PubMed

    Zhang, De-Chao; Redzic, Mersiha; Liu, Hong-Can; Zhou, Yu-Guang; Schinner, Franz; Margesin, Rosa

    2012-03-01

    Two psychrophilic strains, Cr7-05(T) and Cr4-44(T), isolated from alpine glacier cryoconite, were characterized by using a polyphasic approach. Both strains were psychrophilic, showing good growth over a temperature range of 1-20 °C. The chemotaxonomic characteristics of these isolates included the presence of C(18:1)ω7c and summed feature 3 (C(16:1)ω7c and/or C(16:1)ω6c) as the major cellular fatty acids, Q-10 as the predominant ubiquinone and diphosphatidylglycerol, phosphatidylglycerol and unknown glycolipids as major polar lipids. The DNA G+C contents of strains Cr7-05(T) and Cr4-44(T) were 61.4 and 63.6 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two isolates belong to the genus Devosia. The 16S rRNA gene sequence similarity between the two strains was 98.6%, but DNA-DNA hybridization indicated 54% relatedness. Strains Cr7-05(T) and Cr4-44(T) exhibited 16S rRNA gene sequence similarity of 94.7-97.2 and 94.9-96.9%, respectively, to the type strains of recognized Devosia species. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strains Cr7-05(T) and Cr4-44(T) represent two novel species within the genus Devosia, for which the names Devosia psychrophila sp. nov. (type strain Cr7-05(T) =DSM 22950(T) =CGMCC 1.10210(T) =CIP 110130(T)) and Devosia glacialis sp. nov. (type strain Cr4-44(T) =CGMCC 1.10691(T) =LMG 26051(T)) are proposed. An emended description of the genus Devosia is also provided.

  6. Meteorite organics in planetary environments: hydrothermal release, surface activity, and microbial utilization.

    PubMed

    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.

  7. Screening of high α-arbutin producing strains and production of α-arbutin by fermentation.

    PubMed

    Liu, Chun-Qiao; Deng, Li; Zhang, Peng; Zhang, Shu-Rong; Liu, Luo; Xu, Tao; Wang, Fang; Tan, Tian-Wei

    2013-08-01

    A mutant Xanthomonas maltophilia BT-112 with high α-anomer-selective glycosylation activity was screened by a series of mutation methods including UV light, N-methyl-N-nitro-N-nitroso-guanidine treatment and quick neutron mutation. The α-arbutin titer increased 15-folds compared with the parent strain. The optimal conditions for culture medium and the operational conditions for lab-scale fermenter were investigated. Under optimized conditions, the maximal hydroquinone (HQ) tolerance of cells and yield of α-arbutin were 120 mM and 30.6 g/l, respectively. The molar conversion yield of α-arbutin based on the amount of HQ supplied reached 93.6 %. The product was identified as α-arbutin by (13)C NMR and (1)H NMR analysis. In conclusion, the results in this work provide a one-step and cost-effective method for the large-scale production of α-arbutin.

  8. Motion of the Zinc Ions in Catalysis by a di-Zinc Metallo-beta-Lactamase

    SciTech Connect

    R Breece; Z Hu; M Crowder; D Tierney

    2011-12-31

    We report rapid-freeze-quench X-ray absorption spectroscopy of a dizinc metallo-beta-lactamase (MbetaL) reaction intermediate. The Zn(II) ions in the dinuclear active site of the S. maltophilia Class B3 MbetaL move away from each other, by approximately 0.3 A after 10 ms of reaction with nitrocefin, from 3.4 to 3.7 A. Together with our previous characterization of the resting enzyme and its nitrocefin product complex, where the Zn(II) ion separation relaxes to 3.6 A, these data indicate a scissoring motion of the active site that accompanies the ring-opening step. The average Zn(II) coordination number of 4.5 in the resting enzyme appears to be maintained throughout the reaction with nitrocefin. This is the first direct structural information available on early stage dizinc metallo-beta-lactamase catalysis.

  9. Meteorite organics in planetary environments: hydrothermal release, surface activity, and microbial utilization.

    PubMed

    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. PMID:11538427

  10. Meteorite organics in planetary environments: hydrothermal release, surface activity, and microbial utilization

    NASA Astrophysics Data System (ADS)

    Mautner, Michael N.; Leonard, Robert L.; Deamer, David W.

    1995-02-01

    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°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 × 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°C, are nutrients for the humic acid bacterium Pseudomonas maltophilia and efficient nutrients for the oligotroph Flavobacterium oryzihabitans, demonstrating the capability of micro-organisms to metabolize extraterrestrial organics.

  11. In-vitro and in-vivo antimicrobial activities of a novel cephalosporin derivative, CP6162, possessing a dihydroxypyridone moiety at the C-3 side chain.

    PubMed

    Orikasa, Y; Hara, T; Miyata, A; Tamura, A; Kawaharajo, K; Matsumoto, T; Komiya, I; Iwamatsu, K; Shibahara, S; Inouye, S

    1991-01-01

    The antibacterial activity of a novel cephalosporin derivative, CP6162, possessing a dihydroxypyridone moiety at the C-3 side chain, was evaluated in vitro and in vivo, with ceftazidime, aztreonam and cefoperazone as the reference antibiotics. CP6162 showed weak or little activity against Gram-positive bacteria, but potent activity against clinical isolates of the Gram-negative species including strains of Pseudomonas aeruginosa, Ps. cepacia, Acinetobacter sp., Xanthomonas maltophilia, Serratia marcescens, Enterobacter cloacae and Citrobacter freundii, which were resistant to the reference antibiotics. The MICs of CP6162 were only slightly affected by the high producers of beta-lactamases except for cephalosporinase-producing C. freundii. It was, however, affected by the presence of ferric ion. CP6162 showed in-vivo activity paralleling the in-vitro activity, and also showed pharmacokinetic parameters similar to those of ceftazidime in mice and rats.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. Molecular characterization of nitrogen-fixing bacteria isolated from brazilian agricultural plants at São Paulo state

    PubMed Central

    Reinhardt, Érica. L.; Ramos, Patrícia L.; Manfio, Gilson P.; Barbosa, Heloiza R.; Pavan, Crodowaldo; Moreira-Filho, Carlos A.

    2008-01-01

    Fourteen strains of nitrogen-fixing bacteria were isolated from different agricultural plant species, including cassava, maize and sugarcane, using nitrogen-deprived selective isolation conditions. Ability to fix nitrogen was verified by the acetylene reduction assay. All potentially nitrogen-fixing strains tested showed positive hybridization signals with a nifH probe derived from Azospirillum brasilense. The strains were characterized by RAPD, ARDRA and 16S rDNA sequence analysis. RAPD analyses revealed 8 unique genotypes, the remaining 6 strains clustered into 3 RAPD groups, suggesting a clonal origin. ARDRA and 16S rDNA sequence analyses allowed the assignment of 13 strains to known groups of nitrogen-fixing bacteria, including organisms from the genera Azospirillum, Herbaspirillum, Pseudomonas and Enterobacteriaceae. Two strains were classified as Stenotrophomonas ssp. Molecular identification results from 16S rDNA analyses were also corroborated by morphological and biochemical data. PMID:24031239

  17. [Biodegradation of polyhydroxyalkanoates by soil microbiocoenoses of different structures and detection of microorganisms-destructors].

    PubMed

    Boiandin, A N; Prudnikova, S V; Filipenko, M L; Khrapov, E A; Vasil'ev, A D; Volova, T G

    2012-01-01

    Biodegradation of microbial linear polymers of hydroxyalkanoic acids (polyhydroxyalkanoates, PHAs) by soil microbiocoenoses of different structures has been studied during two field seasons in different weather conditions. This process was shown to be influenced by the polymer chemical composition, temperature, humidity, and the microbial soil component. The PHA degradation was accompanied by a decrease in the polymer molecular weight and an increase in the degree of crystallinity, indicating the preferential destruction of the amorphous phase compared to the crystalline one. The quantity of the true PHA destructors developing at the surface of the polymer samples was lower than the quantity of accompanying bacteria. The dominant PHA destructors under the test conditions were identified as bacteria of the genera Variovorax, Stenotrophomonas, Acinetobacter, Pseudomonas, Bacillus, and Xanthomonas and as micromycetes from Penicillium, Paecilomyces, Acremonium, Verticillium. and Zygosporium.

  18. 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

  19. [Composition of the oil-slime microbial community determined by analysis of the 16S rRNA gene].

    PubMed

    Grigor'eva, T V; Laĭkov, A V; Rizvanov, A A; Il'inskaia, O N; Naumova, R P

    2013-01-01

    Analysis of the 16S rRNA genes of the cultured microorganisms of industrial oil-slime revealed predominance (-85-90%) of the Gammaproteobacteria in the community of aerobic heterotrophs and specific oil-slime degraders. Relation of the isolated strains with members of the genera Pseudomonas, Stenotrophomonas, and Enterobacter was established. Analysis of the same gene in the total DNA from the oil-slime revealed greater microbial diversity (-20 operative taxonomic units determined by T-RFLP) than in the cultured part of the community, which included -12 different colony types. Three major restriction fragments were found, with their total area -50%. These results demonstrated the low morphological and phylogenetic diversity of the oil-slime bacterial community.

  20. Endophytic bacteria in Coffea arabica L.

    PubMed

    Vega, Fernando E; Pava-Ripoll, Monica; Posada, Francisco; Buyer, Jeffrey S

    2005-01-01

    Eighty-seven culturable endophytic bacterial isolates in 19 genera were obtained from coffee plants collected in Colombia (n = 67), Hawaii (n = 17), and Mexico (n = 3). Both Gram positive and Gram negative bacteria were isolated, with a greater percentage (68%) being Gram negative. Tissues yielding bacterial endophytes included adult plant leaves, various parts of the berry (e.g., crown, pulp, peduncle and seed), and leaves, stems, and roots of seedlings. Some of the bacteria also occurred as epiphytes. The highest number of bacteria among the berry tissues sampled was isolated from the seed, and includes Bacillus , Burkholderia , Clavibacter , Curtobacterium , Escherichia , Micrococcus , Pantoea , Pseudomonas , Serratia , and Stenotrophomonas . This is the first survey of the endophytic bacteria diversity in various coffee tissues, and the first study reporting endophytic bacteria in coffee seeds. The possible role for these bacteria in the biology of the coffee plant remains unknown.

  1. Treatment of seafood processing wastewater using upflow microbial fuel cell for power generation and identification of bacterial community in anodic biofilm.

    PubMed

    Jayashree, C; Tamilarasan, K; Rajkumar, M; Arulazhagan, P; Yogalakshmi, K N; Srikanth, M; Banu, J Rajesh

    2016-09-15

    Tubular upflow microbial fuel cell (MFC) utilizing sea food processing wastewater was evaluated for wastewater treatment efficiency and power generation. At an organic loading rate (OLR) of 0.6 g d(-1), the MFC accomplished total and soluble chemical oxygen demand (COD) removal of 83 and 95%, respectively. A maximum power density of 105 mW m(-2) (2.21 W m(-3)) was achieved at an OLR of 2.57 g d(-1). The predominant bacterial communities of anode biofilm were identified as RB1A (LC035455), RB1B (LC035456), RB1C (LC035457) and RB1E (LC035458). All the four strains belonged to genera Stenotrophomonas. The results of the study reaffirms that the seafood processing wastewater can be treated in an upflow MFC for simultaneous power generation and wastewater treatment. PMID:27254294

  2. Molecular determinant modulates thermal recovery kinetics and structural integrity of the bacterial BLUF photoreceptor.

    PubMed

    Tanwar, Meenakshi; Nahar, Smita; Gulati, Sahil; Veetil, Sindhu Kandoth; Kateriya, Suneel

    2016-07-01

    BLUF domains are flavin-based photoreceptors which receive the blue light signal and are involved in the sensory transduction. We report a short BLUF photoreceptor (SnfB) in Stenotrophomonas sp. We have investigated photodynamic properties of C terminus truncated and several mutated SnfB proteins. Deletion of the extended C-terminal residues alters the thermal recovery kinetics and also affects the integrity of the SnfB protein. Mutagenesis studies demonstrated that the conserved residues within and outside the flavin-binding pocket also regulates the photocycle properties of the protein. These studies suggest that the C-terminal residues outside the BLUF domain can tune the photodynamic properties of the BLUF protein. PMID:27230699

  3. 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.

  4. The Effects of Mary Rose Conservation Treatment on Iron Oxidation Processes and Microbial Communities Contributing to Acid Production in Marine Archaeological Timbers

    PubMed Central

    Preston, Joanne; Smith, Andrew D.; Schofield, Eleanor J.; Chadwick, Alan V.; Jones, Mark A.; Watts, Joy E. M.

    2014-01-01

    The Tudor warship the Mary Rose has reached an important transition point in her conservation. The 19 year long process of spraying with polyethylene glycol (PEG) has been completed (April 29th 2013) and the hull is air drying under tightly controlled conditions. Acidophilic bacteria capable of oxidising iron and sulfur have been previously identified and enriched from unpreserved timbers of the Mary Rose, demonstrating that biological pathways of iron and sulfur oxidization existed potentially in this wood, before preservation with PEG. This study was designed to establish if the recycled PEG spray system was a reservoir of microorganisms capable of iron and sulfur oxidization during preservation of the Mary Rose. Microbial enrichments derived from PEG impregnated biofilm collected from underneath the Mary Rose hull, were examined to better understand the processes of cycling of iron. X-ray absorption spectroscopy was utilised to demonstrate the biological contribution to production of sulfuric acid in the wood. Using molecular microbiological techniques to examine these enrichment cultures, PEG was found to mediate a shift in the microbial community from a co-culture of Stenotrophomonas and Brevunidimonas sp, to a co-culture of Stenotrophomonas and the iron oxidising Alicyclobacillus sp. Evidence is presented that PEG is not an inert substance in relation to the redox cycling of iron. This is the first demonstration that solutions of PEG used in the conservation of the Mary Rose are promoting the oxidation of ferrous iron in acidic solutions, in which spontaneous abiotic oxidation does not occur in water. Critically, these results suggest PEG mediated redox cycling of iron between valence states in solutions of 75% PEG 200 and 50% PEG 2000 (v/v) at pH 3.0, with serious implications for the future use of PEG as a conservation material of iron rich wooden archaeological artefacts. PMID:24586230

  5. 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

  6. 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

  7. Isolation and characterization of a hydrocarbonoclastic bacterial enrichment from total petroleum hydrocarbon contaminated sediments: potential candidates for bioaugmentation in bio-based processes.

    PubMed

    Di Gregorio, Simona; Siracusa, Giovanna; Becarelli, Simone; Mariotti, Lorenzo; Gentini, Alessandro; Lorenzi, Roberto

    2016-06-01

    Seven hydrocarbonoclastic new bacterial isolates were isolated from dredged sediments of a river estuary in Italy. The sediments were contaminated by shipyard activities since decades, mainly ascribable to the exploitation of diesel oil as the fuel for recreational and commercial navigation of watercrafts. The bacterial isolates were able to utilize diesel oil as sole carbon source. Their metabolic capacities were evaluated by GC-MS analysis, with reference to the depletion of both the normal and branched alkanes, the nC18 fatty acid methyl ester and the unresolved complex mixture of organic compounds. They were taxonomically identified as different species of Stenotrophomonas and Pseudomonas spp. by the combination of amplified ribosomal DNA restriction analysis (ARDRA) and repetitive sequence-based PCR (REP-PCR) analysis. The metabolic activities of interest were analyzed both in relation to the single bacterial strains and to the combination of the latter as a multibacterial species system. After 6 days of incubation in mineral medium with diesel oil as sole carbon source, the Stenotrophomonas sp. M1 strain depleted 43-46 % of Cn-alkane from C28 up to C30, 70 % of the nC18 fatty acid methyl ester and the 46 % of the unresolved complex mixture of organic compounds. On the other hand, the Pseudomonas sp. NM1 strain depleted the 76 % of the nC18 fatty acid methyl ester, the 50 % of the unresolved complex mixture of organic compounds. The bacterial multispecies system was able to completely deplete Cn-alkane from C28 up to C30 and to deplete the 95 % of the unresolved complex mixture of organic compounds. The isolates, either as single strains and as a bacterial multispecies system, were proposed as candidates for bioaugmentation in bio-based processes for the decontamination of dredged sediments. PMID:26755178

  8. 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

  9. Pseudorhodobacter sinensis sp. nov. and Pseudorhodobacter aquaticus sp. nov., isolated from crater lakes.

    PubMed

    Li, Ai-Hua; Liu, Hong-Can; Hou, Wei-Guo; Zhou, Yu-Guang

    2016-08-01

    Three Gram-stain negative, aerobic, non-motile, rod-shaped bacterial strains, Y1R2-4T, Y3R2-3 and DC2N1-10T, isolated from two crater lakes of the Daxinganling Mountains, northern China, were studied to determine their taxonomic position. They grew at 4-30 °C (optimally at 20-25 °C), at pH 6.0-7.5 (optimally at pH 7.0) and in the presence of 0-0.5 % (w/v) NaCl. On the basis of 16S rRNA gene sequence analysis, these strains showed 95.3-96.6 % similarity to members of the genus Pseudorhodobacter, including Pseudorhodobacter ferrugineus DSM 5888T, Pseudorhodobacter wandonensis WT-MW11T, Pseudorhodobacter antarcticus ZS3-33T and Pseudorhodobacter aquimaris HDW-19T. All strains contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The main polar lipids for strains Y1R2-4T and Y3R2-3 were phosphatidylglycerol, phosphatidylcholine, one unidentified aminophospholipid, one unidentified aminolipid, three unidentified phospholipids and two unidentified lipids, and those for strain DC2N1-10T were phosphatidylglycerol, phosphatidylcholine, one unidentified aminophospholipid, one unidentified aminolipid, one unidentified phospholipid and several unidentified lipids. The DNA G+C contents of strains Y1R2-4T, Y3R2-3 and DC2N1-10T were 61.9, 61.0 and 60.0 mol%, respectively. In addition, strain Y1R2-4T shared less than 50 % DNA-DNA relatedness to strain DC2N1-10T. Based on these differences in genetic, physiological and chemotaxonomic properties, strains Y1R2-4T, Y3R2-3 and DC2N1-10T were considered to represent two novel species of the genus Pseudorhodobacter, for which the names Pseudorhodobacter sinensis sp. nov. (type strain Y1R2-4T=CGMCC1.14435T=KCTC 52039T) and Pseudorhodobacter aquaticus sp. nov. (type strain DC2N1-10T=CGMCC1.14433T=KCTC 52040T) are proposed. PMID:27045957

  10. Pseudomonas zhaodongensis sp. nov., isolated from saline and alkaline soils.

    PubMed

    Zhang, Lei; Pan, Yuanyuan; Wang, Kaibiao; Zhang, Xiaoxia; Zhang, Cheng; Zhang, Shuang; Fu, Xiaowei; Jiang, Juquan

    2015-03-01

    Strain NEAU-ST5-21(T) was isolated from saline and alkaline soils in Zhaodong City, Heilongjiang Province, China. It was aerobic, Gram-stain-negative, rod-shaped and motile with a polar flagellum. It produced yellow-orange colonies with a smooth surface, and grew in the presence of 0-5 % (w/v) NaCl (optimum 0 %, w/v), at temperatures of 20-40 °C (optimum 28 °C) and at pH 7-11 (optimum pH 7). Phylogenetic analyses based on the separate 16S rRNA gene sequences and concatenated 16S rRNA, gyrB and rpoD gene sequences indicated that strain NEAU-ST5-21(T) belongs to the genus Pseudomonas in the class Gammaproteobacteria. The most closely related species is Pseudomonas xanthomarina, whose type strain (KMM 1447(T)) showed gene sequence similarities of 99.0 % for 16S rRNA, 81.8 % for gyrB and 85.0 % for rpoD with strain NEAU-ST5-21(T). DNA-DNA hybridization values between strain NEAU-ST5-21(T) and P. xanthomarina DSM 18231(T), Pseudomonas kunmingensis CGMCC 1.12273(T), Pseudomonas stutzeri DSM 5190(T), Pseudomonas oleovorans subsp. lubricantis DSM 21016(T), Pseudomomas chengduensis CGMCC 2318(T), Pseudomonas alcaliphila DSM 17744(T) and Pseudomonas toyotomiensis DSM 26169(T) were 52±0 % to 25±2 %. The DNA G+C content of strain NEAU-ST5-21(T) was 65 mol%. The major fatty acids (>10 %) were C18 : 1ω7c and/or C18 : 1ω6c, C16 : 1ω7c and/or C16 : 1ω6c and C16 : 0, the predominant respiratory quinone was ubiquinone 9, and polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, one unknown phospholipid, phosphatidylglycerol, one unknown aminolipid, one unknown lipid and a glycolipid. The proposed name is Pseudomonas zhaodongensis sp. nov., NEAU-ST5-21(T) ( = ACCC 06362(T) = DSM 27559(T)) being the type strain. PMID:25574037

  11. Haloparvum sedimenti gen. nov., sp. nov., a member of the family Haloferacaceae.

    PubMed

    Chen, Shaoxing; Liu, Hong-Can; Zhou, Jian; Xiang, Hua

    2016-06-01

    Two extremely halophilic archaeal strains, DYS4T and Y2, were isolated from rock salt of the Jiangcheng Salt Mine, Yunnan province, China. Cells of the two strains were non-motile, pleomorphic rods and Gram-stain-negative. The cells produced light red-pigmented colonies. Strains DYS4T and Y2 required 2.6-3.4 M NaCl, pH 7.5- 8.0 and 42 ºC in aerobic conditions for optimal growth. Mg2+ was required for growth. The major polar lipids of both strains were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and sulfated mannosyl glucosyl diether. An unidentified minor glycolipid spot was present for strains DYS4T and Y2, which differentiates them from the closely related species of the genera Halorubrum and Halopenitus. The lipid core of the glycolipid was sn-2,3-diphytanylglycerol (C20C20). The sequence similarity of the 16S rRNA gene demonstrated that the closest relatives of strains DYS4T and Y2 were Halorubrum aidingense 31-hongT (94.1 % and 93.6 % 16S rRNA gene sequence similarity to DYS4T and Y2, respectively) and Halopenitus salinus SKJ47T (93.4% and 93.1%). Phylogenetic analysis of the 16S rRNA gene and the rpoB' gene revealed that strains DYS4T and Y2 formed an independent lineage closely related to the genera Halorubrum and Halopenitus. The DNA G+C contents of strains DYS4T and Y2 were 68.2 and 67.0 mol%, respectively. The DNA-DNA relatedness value between strains DYS4T and Y2 was 90.0 ± 0.5%, while that between strain DYS4T and other closest relatives was less than 26 % (19 ± 0.7 % for Halorubrum aidingense 31-hongT and 25 ± 0.3% for Halopenitus salinus SKJ47T). The phenotypic, chemotaxonomic and phylogenetic properties suggest that strains DYS4T and Y2 (=CGMCC 1.15000=JCM 30892) represent a novel species of a new genus within the family Haloferacaceae, for which the name Haloparvum sedimenti gen. nov., sp. nov. is proposed. The type strain of the type species is DYS4T (=CGMCC 1.14998T=JCM 30891T

  12. Pseudorhodobacter sinensis sp. nov. and Pseudorhodobacter aquaticus sp. nov., isolated from crater lakes.

    PubMed

    Li, Ai-Hua; Liu, Hong-Can; Hou, Wei-Guo; Zhou, Yu-Guang

    2016-08-01

    Three Gram-stain negative, aerobic, non-motile, rod-shaped bacterial strains, Y1R2-4T, Y3R2-3 and DC2N1-10T, isolated from two crater lakes of the Daxinganling Mountains, northern China, were studied to determine their taxonomic position. They grew at 4-30 °C (optimally at 20-25 °C), at pH 6.0-7.5 (optimally at pH 7.0) and in the presence of 0-0.5 % (w/v) NaCl. On the basis of 16S rRNA gene sequence analysis, these strains showed 95.3-96.6 % similarity to members of the genus Pseudorhodobacter, including Pseudorhodobacter ferrugineus DSM 5888T, Pseudorhodobacter wandonensis WT-MW11T, Pseudorhodobacter antarcticus ZS3-33T and Pseudorhodobacter aquimaris HDW-19T. All strains contained Q-10 as the predominant ubiquinone and C18 : 1ω7c as the major fatty acid. The main polar lipids for strains Y1R2-4T and Y3R2-3 were phosphatidylglycerol, phosphatidylcholine, one unidentified aminophospholipid, one unidentified aminolipid, three unidentified phospholipids and two unidentified lipids, and those for strain DC2N1-10T were phosphatidylglycerol, phosphatidylcholine, one unidentified aminophospholipid, one unidentified aminolipid, one unidentified phospholipid and several unidentified lipids. The DNA G+C contents of strains Y1R2-4T, Y3R2-3 and DC2N1-10T were 61.9, 61.0 and 60.0 mol%, respectively. In addition, strain Y1R2-4T shared less than 50 % DNA-DNA relatedness to strain DC2N1-10T. Based on these differences in genetic, physiological and chemotaxonomic properties, strains Y1R2-4T, Y3R2-3 and DC2N1-10T were considered to represent two novel species of the genus Pseudorhodobacter, for which the names Pseudorhodobacter sinensis sp. nov. (type strain Y1R2-4T=CGMCC1.14435T=KCTC 52039T) and Pseudorhodobacter aquaticus sp. nov. (type strain DC2N1-10T=CGMCC1.14433T=KCTC 52040T) are proposed.

  13. Psychroflexus salis sp. nov. and Psychroflexus planctonicus sp. nov., isolated from a salt lake.

    PubMed

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

    2016-01-01

    Two Gram-stain-negative, catalase- and oxidase-positive, strictly aerobic, non-motile, moderately halophilic bacteria (strains X15M-6T and X15M-8T) were isolated from Lake Xiaochaidan, a salt lake in Qaidam basin, Qinghai Province, China. Cells of X15M-6T were rod-like or coccoid, 0.5-0.9 μm wide and 0.9-1.5 μm long; cells of X15M-8T were rods, 0.3-0.6 μm wide and 1.2-2.2 μm long. Growth was observed in the presence of 0.5-14.0 % (w/v) NaCl (optimum, 3.0 %) and at pH 6.5-10.0 (optimum, pH 7.0-7.5) for both. X15M-6T and X15M-8T grew at 10-35 °C (optimum, 20-25 °C) and 4-35 °C (optimum, 25 °C), respectively. Both contained iso-C15 : 0, anteiso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids, phosphatidylethanolamine and an unknown lipid as the major polar lipids, and menaquinone MK-6 as the major respiratory quinone. The DNA G+C contents were 32.8 and 35.0 mol% for X15M-6T and X15M-8T, respectively. Phylogenetic trees based on 16S rRNA gene sequences showed that both strains belonged to the genus Psychroflexus and formed a separate lineage. In addition, strains X15M-6T and X15M-8T shared 96.8 % 16S rRNA gene sequence similarity and showed highest similarities to members of the genus Psychroflexus (92.7-93.5 and 91.8-93.1 %, respectively). Based on the above data, it is concluded that strains X15M-6T and X15M-8T represent two novel species of the genus Psychroflexus, for which the names Psychroflexus salis sp. nov. (type strain X15M-6T = CGMCC 1.12925T = JCM 30615T) and Psychroflexus planctonicus sp. nov. (type strain X15M-8T = CGMCC 1.12931T = JCM 30616T) are proposed. PMID:26475261

  14. Psychroflexus salis sp. nov. and Psychroflexus planctonicus sp. nov., isolated from a salt lake.

    PubMed

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

    2016-01-01

    Two Gram-stain-negative, catalase- and oxidase-positive, strictly aerobic, non-motile, moderately halophilic bacteria (strains X15M-6T and X15M-8T) were isolated from Lake Xiaochaidan, a salt lake in Qaidam basin, Qinghai Province, China. Cells of X15M-6T were rod-like or coccoid, 0.5-0.9 μm wide and 0.9-1.5 μm long; cells of X15M-8T were rods, 0.3-0.6 μm wide and 1.2-2.2 μm long. Growth was observed in the presence of 0.5-14.0 % (w/v) NaCl (optimum, 3.0 %) and at pH 6.5-10.0 (optimum, pH 7.0-7.5) for both. X15M-6T and X15M-8T grew at 10-35 °C (optimum, 20-25 °C) and 4-35 °C (optimum, 25 °C), respectively. Both contained iso-C15 : 0, anteiso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids, phosphatidylethanolamine and an unknown lipid as the major polar lipids, and menaquinone MK-6 as the major respiratory quinone. The DNA G+C contents were 32.8 and 35.0 mol% for X15M-6T and X15M-8T, respectively. Phylogenetic trees based on 16S rRNA gene sequences showed that both strains belonged to the genus Psychroflexus and formed a separate lineage. In addition, strains X15M-6T and X15M-8T shared 96.8 % 16S rRNA gene sequence similarity and showed highest similarities to members of the genus Psychroflexus (92.7-93.5 and 91.8-93.1 %, respectively). Based on the above data, it is concluded that strains X15M-6T and X15M-8T represent two novel species of the genus Psychroflexus, for which the names Psychroflexus salis sp. nov. (type strain X15M-6T = CGMCC 1.12925T = JCM 30615T) and Psychroflexus planctonicus sp. nov. (type strain X15M-8T = CGMCC 1.12931T = JCM 30616T) are proposed.

  15. Bacillus lindianensis sp. nov., a novel alkaliphilic and moderately halotolerant bacterium isolated from saline and alkaline soils.

    PubMed

    Dou, Guiming; Liu, Hongcan; He, Wei; Ma, Yuchao

    2016-01-01

    Two alkaliphilic and halotolerant Gram-stain positive, rod-shaped and endospore-forming bacteria, designated strains 12-3(T) and 12-4, were isolated from saline and alkaline soils collected in Lindian county, Heilongjiang province, China. Both strains were observed to grow well at a wide range of temperature and pH values, 10-45 °C and pH 8-12, with optimal growth at 37 °C and pH 9.0, respectively. Growth of the two strains was found to occur at total salt concentrations of 0-12 % (w/v), with an optimum at 4 % (w/v). The G+C contents of the genomic DNA of strains 12-3(T) and 12-4 were determined to be 42.7 and 42.4 mol%, respectively, and the major cellular fatty acids were identified as anteiso-C15:0 and anteiso-C17:0. In isolate 12-3(T), meso-diaminopimelic acid was found to be the diagnostic diamino acid of the cell wall peptidoglycan; diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol were identified as the major cellular polar lipids; and menaquinone-7 was identified as the predominant isoprenoid quinone. Strains 12-3(T) and 12-4 share very close 16S rRNA gene sequence similarity (99.74 %) and their DNA-DNA relatedness was 95.3 ± 0.63 %, meaning that the two strains can be considered to belong to the same species. 16S rRNA gene sequence-based phylogenetic analysis revealed strains 12-3(T) and 12-4 exhibit high similarities to Bacillus pseudofirmus DSM 8715(T) (98.7 %), Bacillus marmarensis DSM 21297(T) (97.2 %) and Bacillus nanhaiisediminis CGMCC 1.10116(T) (97.1 and 97.0 %, respectively). DNA-DNA hybridization values between isolate 12-3(T) and the type strains of closely related Bacillus species were below 30 %. On the basis of the polyphasic evidence presented, strains 12-3(T) and 12-4 are considered to represent a novel species of the genus Bacillus, for which the name Bacillus lindianensis sp. nov. is proposed. The type strain is 12-3(T) (DSM 26864(T) = CGMCC 1.12717(T)). PMID:26604103

  16. Vibrio salilacus sp. nov., a new member of the Anguillarum clade with six alleles of the 16S rRNA gene from a saline lake.

    PubMed

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

    2015-08-01

    A Gram-stain-negative, catalase- and oxidase-positive, facultatively aerobic bacterium, strain DSG-S6T, was isolated from Dasugan Lake (salinity 3.1%, w/w), China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain DSG-S6T were non-spore-forming, slightly bent rods, and motile by means of a single polar flagellum. Growth occurred in the presence of 0-7.0% (w/v) NaCl (optimum, 2.0%), at 4-35 °C (optimum, 30 °C) and at pH 6.0-10.5 (optimum, pH 8.0-8.5). C16 : 0, C18 : 1ω7c and C16 : 1ω7c and/or C16 : 1ω6c were the major fatty acids. Six alleles of the 16S rRNA gene sharing 98.9-99.9  % similarity were detected in strain DSG-S6T, which showed highest 16S rRNA gene sequence similarity to Vibrio aestuarianus ATCC 35048T (97.7 %), then to Vibrio pacinii LMG 19999T (97.6%) and Vibrio metschnikovii CIP 69.14T (96.8%). Multilocus sequence analysis of four housekeeping genes and 16S rRNA genes clearly clustered it as a member of the Anguillarum clade. Mean DNA-DNA relatedness between strain DSG-S6T and V. aestuarianus NBRC 15629T, V. pacinii CGMCC 1.12557T and V. metschnikovii JCM 21189T was 20.6 ± 2.3, 38.1 ± 3.5 and 24.2 ± 2.8%, respectively. The DNA G+C content was 46.8 mol% (Tm). Based on the data, it is concluded that strain DSG-S6T represents a novel species of the genus Vibrio, for which the name Vibrio salilacus sp. nov. is proposed. The type strain is DSG-S6T ( = CGMCC 1.12427T = JCM 19265T).

  17. Marinobacter aromaticivorans sp. nov., a polycyclic aromatic hydrocarbon-degrading bacterium isolated from sea sediment.

    PubMed

    Cui, Zhisong; Gao, Wei; Xu, Guangfei; Luan, Xiao; Li, Qian; Yin, Xiaofei; Huang, Deming; Zheng, Li

    2016-01-01

    A rod-shaped, Gram-stain-negative, slightly halotolerant bacterium, designated strain D15-8PT, was isolated from a sediment sample from the South China Sea. The strain could grow in NaCl concentrations ranging from 0.5 % to 10 % (w/v) (optimum 0.5-1.5 %), and could be cultivated at 10-40 °C (optimum 25 °C) and pH 5.5-9.5 (optimum pH 7.0-8.0). The strain was positive for catalase, oxidase, and hydrolysis of Tween 80, but negative for hydrolysis of DNA and gelatin, nitrite reduction, indole production, Voges-Proskauer reaction, and methyl red test. Strain D15-8PT could biodegrade naphthalene, phenanthrene, and anthracene. The major respiratory quinone was Q-9. The main cellular fatty acids were C12 : 0 (11.5 %), C14 : 0 3-methyl (22.0 %), C16 : 0 (19.2 %), C16 : 1ω9c (22.9 %), and C18 : 1ω9c (6.7 %). The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminophospholipid and an unidentified phospholipid. The DNA G+C content was 56.8 mol%. Phylogenetic analyses based on 16S rRNA genes showed that strain D15-8PT was most closely related to Marinobacter maritimus JCM 12521T (98.5 % 16S rRNA gene sequence similarity), Marinobacter antarcticus CGMCC 1.10835T (98.1 %), Marinobacter lipolyticus DSM 15157T (97.1 %), and Marinobacter guineae CECT 7243T (97.0 %). Results of the gyrB gene analysis and DNA-DNA hybridization were both less than the cut-off values (90 % for gyrB gene sequence similarity and 70 % for DNA-DNA hybridization). On the basis of this taxonomic study using a polyphasic approach, strain D15-8PT represents a novel species of the genus Marinobacter, for which the name Marinobacter aromaticivorans sp. nov. is proposed. The type strain is D15-8PT ( = CGMCC 1.11015T = KCTC 23781T).

  18. Sinimarinibacterium flocculans gen. nov., sp. nov., a gammaproteobacterium from offshore surface seawater.

    PubMed

    Zhang, Xin-Qi; Sun, Cong; Wang, Chun-Sheng; Zhang, Xin; Zhou, Xiang; Wu, Yue-Hong; Xu, Xue-Wei; Wu, Min

    2015-10-01

    Two aerobic, rod-shaped, non-motile, non-sporulating and Gram-staining-negative bacterial strains, namely NH6-24T and Za3-11, were isolated from the surface seawater of the South China Sea and the estuary of the Yangtze River, respectively. The two isolates grew at 14–44 °C (optimum 37–40 °C) and pH 6.0–8.5 (optimum pH 7.0–7.5). The sea salt ranges for growth were 0.5–10 % (w/v) (optimum 1–2.5 %) for strain NH6-24T and 0–12 % (w/v) (optimum 0.5–4.5 %) for strain Za3-11.Both strains could grow in the absence of NaCl. Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that the two isolates showed closest affinity to the genera Fontimonas (96.0 %) and Solimonas (94.1–95.1 %) and formed a single lineage in the cluster of the family Solimonadaceae. The predominant isoprenoid quinone was ubiquinone-8.The major fatty acids were C18 : 1ω7c, iso-C16 : 0 and C16 : 0.The dominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 65 mol%. Based on the polyphasic taxonomic characterization, strains NH6-24T and Za3-11 are considered to represent a novel species of a novel genus, for which the name Sinimarinibacterium flocculans gen. nov., sp. nov. is proposed. The type strain of the type species is NH6-24T ( = CGMCC 1.10815T = JCM 17607T) and an additional strain is Za3-11 ( = CGMCC 1.10816 = JCM 17606).

  19. Dickeyafangzhongdai sp. nov., a plant-pathogenic bacterium isolated from pear trees (Pyrus pyrifolia).

    PubMed

    Tian, Yanli; Zhao, Yuqiang; Yuan, Xiaoli; Yi, Jianping; Fan, Jiaqin; Xu, Zhigang; Hu, Baishi; De Boer, Solke H; Li, Xiang

    2016-09-01

    Gram-stain-negative, pectinolytic bacteria were repeatedly isolated from pear trees displaying symptoms of bleeding canker in China. Three strains, JS5T, LN1 and QZH3, had identical 16S rRNA gene sequences that shared 99 % similarity to the type strain of Dickeya dadantii. Phylogenetic analysis of strains JS5T, LN1 and QZH3 with isolates representing all species of the genus Dickeya and related Pectobacterium species supported their affiliation to Dickeya. Multi-locus sequence typing employing concatenated sequences encoding recA, fusA, gapA, purA, rplB, dnaX and the intergenic spacer illustrated a phylogeny which placed strains JS5T, LN1 and QZH3 as a distinct clade, separate from all other species of the genus Dickeya. Average nucleotide identity values obtained in comparison with all species of the genus Dickeya supported the distinctiveness of strain JS5T within the genus Dickeya. Additionally, all three strains were phenotypically distinguished from other species of the genus Dickeya by failing to hydrolyse casein, and by producing acids from (-)-d-arabinose, (+)melibiose, (+)raffinose, mannitol and myo-inositol, but not from 5-keto-d-gluconate or β-gentiobiose. The name Dickeya fangzhongdai sp. nov. is proposed to accommodate these strains; the type strain is JS5T (=CGMCC 1.15464T=DSM 101947T). PMID:27045848

  20. 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)).

  1. Halorubrum ejinorense sp. nov., isolated from Lake Ejinor, Inner Mongolia, China.

    PubMed

    Castillo, A M; Gutiérrez, M C; Kamekura, M; Xue, Y; Ma, Y; Cowan, D A; Jones, B E; Grant, W D; Ventosa, A

    2007-11-01

    A novel halophilic archaeon, strain EJ-32T, was isolated from water from Lake Ejinor in Inner Mongolia, China. The taxonomy of strain EJ-32T was studied by using a polyphasic approach. On the basis of 16S rRNA gene sequence similarities, strain EJ-32T was shown to be phylogenetically related to Halorubrum coriense (97.9%), Halorubrum trapanicum (97.9%), Halorubrum sodomense (97.8%), Halorubrum tebenquichense (97.8%), Halorubrum xinjiangense (97.6%), Halorubrum terrestre (97.4%), Halorubrum distributum (97.1%) and Halorubrum saccharovorum (96.4%). Strain EJ-32T was found to be neutrophilic, non-motile and Gram-negative. It grew in medium containing saturation concentrations of NaCl and did not require magnesium for optimal growth. The G+C content of the DNA is 64.0 mol%. Values for DNA-DNA hybridization with respect to phylogenetically related Halorubrum species were CGMCC 1.6782T=JCM 14265T). PMID:17978215

  2. Optimization of the nutrition for biodegradation of vinasse by Aspergillus oryzae using response surface methodology.

    PubMed

    Zhang, Zhicai; Liu, Dan; Feng, Fan; Li, Jiashao; Li, Ming; Pang, Qiaoxia; Chen, Keping

    2013-01-01

    Direct discharge of vinasse from the distillery industry causes resource wasting and environmental destruction due to its mass of organic components. Aspergillus oryzae CGMCC5992 is capable of degrading the organic substrates of wastewater. One-factor-at-a-time design was adopted to select the most important nutrients influencing the degradation of organic materials of vinasse. Box-Behnken Design (BBD) with Design-Expert (8.0.4) was used to develop mathematical model equations, study responses, and optimize concentrations of the key nutrients to improve the degradation efficiency. The optimized medium containing 0.3 g/L urea, 20.73 mg/L ZnSO(4), and 19.79 mg/L vitamin B(6) was supplied to 10-times diluted vinasse; under the optimal condition, a decrease of chemical oxygen demand (COD) from 4,635 to 323 mg/L in vinasse was achieved in 5 days. The reduction of vinasse COD after the optimization of nutrient condition in this study is more significant than those reported previously. PMID:23306254

  3. Fulvimarina manganoxydans sp. nov., isolated from a deep-sea hydrothermal plume in the south-west Indian Ocean.

    PubMed

    Ren, Fei; Zhang, Limin; Song, Lei; Xu, Shiyao; Xi, Lijun; Huang, Li; Huang, Ying; Dai, Xin

    2014-08-01

    An aerobic, Mn(II)-oxidizing, Gram-negative bacterium, strain 8047(T), was isolated from a deep-sea hydrothermal vent plume in the south-west Indian Ocean. The strain was rod-shaped and motile with a terminal flagellum, and formed yellowish colonies. It produced catalase and oxidase, hydrolysed gelatin and reduced nitrate. 16S rRNA gene sequence analysis showed that strain 8047(T) belonged to the order Rhizobiales of the class Alphaproteobacteria, and was phylogenetically most closely related to the genus Fulvimarina, sharing 94.4% sequence identity with the type strain of the type species. The taxonomic affiliation of strain 8047(T) was supported by phylogenetic analysis of four additional housekeeping genes, gyrB, recA, rpoC and rpoB. The predominant respiratory lipoquinone of strain 8047(T) was Q-10, the major fatty acid was C(18 : 1)ω7c and the DNA G+C content was 61.7 mol%. On the basis of the phenotypic and genotypic characteristics determined in this study, strain 8047(T) represents a novel species within the genus Fulvimarina, for which the name Fulvimarina manganoxydans sp. nov. is proposed. The type strain is strain 8047(T) ( = CGMCC1.10972(T) = JCM 18890(T)).

  4. Paenibacillus abyssi sp. nov., isolated from an abyssal sediment sample from the Indian Ocean.

    PubMed

    Huang, Xiao-Fang; Wang, Fa-Zuo; Zhang, Wei; Li, Jie; Ling, Juan; Yang, Jian; Dong, Jun-De; Tian, Xin-Peng

    2014-12-01

    A Gram-positive, rod-shaped bacterium, designated strain SCSIO N0306(T), was isolated from an abyssal sediment sample collected from the Indian Ocean. The isolate was found to grow optimally at 0-2 % (w/v) NaCl, pH 7.0 and 30 °C. Comparative analysis of the 16S rRNA gene sequence showed that the isolate SCSIO N0306(T) belongs phylogenetically to the genus Paenibacillus, and to be most closely related to P. algorifonticola XJ259(T) (with 95.47 % sequence similarity), sharing less than 95.0 % sequence similarity with all other taxa of this genus. Chemotaxonomic analysis revealed MK-7 as the major isoprenoid quinone, the DNA G+C content was determined to be 45.5 mol%, and anteiso-C15:0, C16:0, and iso-C15:0 were identified as the major fatty acids. On the basis of this polyphasic taxonomic data, isolate SCSIO N0306(T) is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus abyssi sp. nov. is proposed. The type strain is SCSIO N0306(T) (= DSM 26238(T) = CGMCC 1.12987(T)).

  5. Actinomycetospora atypica sp. nov., a novel soil actinomycete and emended description of the genus Actinomycetospora.

    PubMed

    Zhang, Yuejing; Liu, Chongxi; Zhang, Ji; Shen, Yue; Li, Chuang; He, Hairong; Wang, Xiangjing; Xiang, Wensheng

    2014-05-01

    A novel actinomycete, designated strain NEAU-st4(T), was isolated from a soil sample collected from Shaanxi province, Northwest China and characterized using a polyphasic approach. 16S rRNA gene sequence analysis revealed that strain NEAU-st4(T) has the highest sequence similarities with Actinomycetospora rishiriensis RI109-Li102(T) (99.4 %), Actinomycetospora corticicola 014-5(T) (99.1 %), Actinomycetospora chiangmaiensis YIM 0006(T) (98.8 %) and Actinomycetospora iriomotensis IR73-Li102(T) (98.2 %). However, the low level of DNA-DNA relatedness differentiated strain NEAU-st4(T) from its closest phylogenetic neighbours. The main chemotaxonomic properties of strain NEAU-st4(T), such as the diamino acid of the peptidoglycan, the whole-cell hydrolysates, the predominant menaquinones and the phospholipid profile, supported its classification within the genus Actinomycetospora. The distinctive morphology of this strain compared with that of other members in the genus Actinomycetospora is the formation of sporangia directly on the substrate hyphae. Phenotypic and genotypic differences also allowed the distinction of the strain from closely related species. Consequently, strain NEAU-st4(T) represents a new species of the genus Actinomycetospora, for which the name Actinomycetospora atypica sp. nov. is proposed. The type strain is NEAU-st4(T) (=CGMCC 4.7093(T) = DSM 45873(T)).

  6. Myceligenerans xiligouense gen. nov., sp. nov., a novel hyphae-forming member of the family Promicromonosporaceae.

    PubMed

    Cui, Xiaolong; Schumann, Peter; Stackebrandt, Erko; Kroppenstedt, Reiner M; Pukall, Rüdiger; Xu, Lihua; Rohde, Manfred; Jiang, Chenglin

    2004-07-01

    Strain XLG9A10.2T was isolated from an alkaline salt marsh soil in western China. 16S rRNA gene sequence analysis indicated that strain XLG9A10.2T constitutes a distinct lineage within the family Promicromonosporaceae, sharing 94.8-95.1% gene similarity with members of the genus Promicromonospora and 94.4-95.7% similarity with those of Xylanimonas and related genera. The general colony and cell morphology of strain XLG9A10.2T is similar to that of members of Promicromonospora, but differs from members of the genus Xylanimonas in forming a well-developed branching mycelium and production of coccoid spores. Strain XLG9A10.2T shows the peptidoglycan type A4alpha (L-lys<--L-thr<--D-Glu), contains glucose, mannose and galactose as whole cell sugars and has MK-9(H4) and MK-9(H6) as major menaquinones, while phospholipids are phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, three unidentified phospholipids and one unidentified glycolipid. The DNA base composition is 71.9 mol% G+C. On the basis of morphological, chemotaxonomic, metabolic and phylogenetic differences from other species of Promicromonosporaceae, a new genus and species, Myceligenerans xiligouense gen. nov., sp. nov., is proposed. The type strain is XLG9A10.2T (=DSM 15700T=CGMCC 1.3458T.)

  7. Dinghuibacter silviterrae gen. nov., sp. nov., isolated from forest soil.

    PubMed

    Lv, Ying-Ying; Wang, Jia; Chen, Mei-Hong; You, Jia; Qiu, Li-Hong

    2016-04-01

    A novel Gram-stain negative, non-motile, rod-shaped, aerobic bacterial strain, designated DHOA34T, was isolated from forest soil of Dinghushan Biosphere Reserve, Guangdong Province, China. Comparative 16S rRNA gene sequence analysis showed that it exhibited highest similarity with Flavisolibacter ginsengiterrae Gsoil 492T and Flavitalea populi HY-50RT, at 90.89 and 90.83%, respectively. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, DHOA34T formed an independent lineage within the family Chitinophagaceae but was distinct from all recognized species and genera of the family. The major cellular fatty acids of DHOA34T included iso-C15:0, anteiso-C15:0, iso-C17:0 3-OH and summed feature 3 (C16:1ω6c and/or C16:1ω7c). The DNA G+C content was 51.6 mol% and the predominant quinone was menaquinone 7 (MK-7). Flexirubin pigments were produced. The phenotypic, chemotaxonomic and phylogenetic data demonstrate consistently that strain DHOA34T represents a novel species of a new genus in the family Chitinophagaceae, for which the name Dinghuibacter silviterrae gen. nov., sp. nov. is proposed. The type strain of Dinghuibacter silviterrae is DHOA34T (=CGMCC 1.15023T=KCTC 42632T). PMID:26828023

  8. Microbial community structure of ethanol type fermentation in bio-hydrogen production.

    PubMed

    Ren, Nanqi; Xing, Defeng; Rittmann, Bruce E; Zhao, Lihua; Xie, Tianhui; Zhao, Xin

    2007-05-01

    Three continuous stirred-tank reactors (CSTRs) were used for H(2) production from molasses wastewater at influent pH of 6.0-6.5 (reactor A), 5.5-6.0 (reactor B), or 4.0-4.5 (reactor C). After operation for 28 days, the microbial community formed ethanol type (C), propionate type (A) and ethanol-butyrate-mixed type (B) fermentation. The H(2) production rate was the highest for ethanol type fermentation, 0.40 l (g VSS)(-1) day(-1) or 0.45 l H(2) (g COD removed)(-1). Microbial community dynamics and diversity were analysed using double-gradient denaturing gradient gel electrophoresis (DG-DGGE). Denaturing gradient gel electrophoresis profiles indicated that the community structures changed quickly in the first 14 days. Phylogenetic analysis indicated that the dominant bacterial groups were low G+C Gram-positive bacteria, Bacteroides, gamma-Proteobacteria and Actinobacteria; alpha-Proteobacteria, beta-Proteobacteria, delta-Proteobacteria and Spirochaetes were also presented as minor groups in the three reactors. H(2)-producing bacteria were affiliated with Ethanoligenens, Acetanaerobacterium, Clostridium, Megasphaera, Citrobacter and Bacteroides. An ethanol-based H(2)-producing bacterium, Ethanoligenens harbinense CGMCC1152, was isolated from reactor C and visualized using fluorescence in situ hybridization (FISH) to be 19% of the eubacteria in reactor C. In addition, isoenzyme activity staining for alcohol dehydrogenase (ADH) supported that the majority of ethanol-producing bacteria were affiliated with Ethanoligenens in the microbial community.

  9. Saccharothrix carnea sp. nov., an actinobacterium isolated from soil.

    PubMed

    Liu, Chongxi; Guan, Xuejiao; Wang, Shurui; Zhao, Junwei; Wang, Haiyan; He, Hairong; Xiang, Wensheng; Wang, Xiangjing

    2014-12-01

    A novel actinobacterium, designated strain NEAU-yn17(T), was isolated from a soil sample collected at the wastewater discharge site of a pesticide factory in Harbin, northern China, and characterized using a polyphasic approach. Morphological and chemotaxonomic properties of strain NEAU-yn17(T) were consistent with the description of the genus Saccharothrix, such as the spore arrangement, the diamino acid of the peptidoglycan, the whole-cell hydrolysates, the predominant menaquinone and the phospholipid profile. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that strain NEAU-yn17(T) should also be classified in the genus Saccharothrix, with Saccharothrix saharensis DSM 45456(T) (99.52 % sequence similarity) and Saccharothrix xinjiangensis JCM 12329(T) (99.04 %) as the nearest phylogenetic relatives. A combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-yn17(T) can be distinguished from its closest relatives. Therefore, strain NEAU-yn17(T) represents a novel species of the genus Saccharothrix, for which the name Saccharothrix carnea sp. nov. is proposed. The type strain is NEAU-yn17(T) ( = CGMCC 4.7097(T) = DSM 45878(T)). PMID:25256705

  10. Cellulomonas marina sp. nov., isolated from deep-sea water.

    PubMed

    Zhang, Limin; Xi, Lijun; Qiu, Danheng; Song, Lei; Dai, Xin; Ruan, Jisheng; Huang, Ying

    2013-08-01

    A bacterial strain FXJ8.089(T) was isolated from deep-sea water collected from the southwest Indian Ocean (49° 39' E 37° 47' S) at a depth of 2800 m, and its taxonomic position was investigated by a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain FXJ8.089(T) belonged to the genus Cellulomonas and had the highest similarities with Cellulomonas oligotrophica (96.9 %) and Cellulomonas aerilata (96.6 %). It contained MK-9(H4) as the predominant menaquinone. The polar lipids were diphosphatidylglycerol and phosphatidylinositol mannosides. The cell-wall peptidoglycan type was A4β with an interpeptide bridge L-Orn-D-Glu. The cell-wall sugars were glucose, mannose and ribose. The DNA G+C content was 70.3 mol%. The strain also showed a number of physiological and biochemical characteristics that were distinct from the closely related species. Based on phenotypic and genotypic data, strain FXJ8.089(T) (= CGMCC 4.6945(T) = DSM 24960(T)) represents a novel species of the genus Cellulomonas, for which the name Cellulomonas marina sp. nov. is proposed.

  11. Bacillus beringensis sp. nov., a psychrotolerant bacterium isolated from the Bering Sea.

    PubMed

    Yu, Yong; Li, Hui-Rong; Zeng, Yin-Xin; Chen, Bo

    2011-03-01

    Psychrotolerant Bacillus-like strains BR035(T) and BR011 were isolated from seawater of the Bering Sea and were characterized by means of a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that these strains were related to the members of the genus Bacillus and had the highest 16S rRNA gene sequence similarity with Bacillus korlensis ZLC-26(T). DNA-DNA hybridization experiments confirmed that strains BR035(T) and BR011 belonged to the same species and were distinct from their closest relatives. The cells were Gram-positive, rods, motile, spore-forming and psychrotolerant. The temperature range for growth was 4-42°C. The main respiratory quinone was MK-7. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unknown aminolipid and two unknown phospholipids. The major cellular fatty acids were iso-C15:0, anteiso-C15:0, iso-C14:0 and C16:1ω7c alcohol. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The genomic DNA G + C content was 37.6-37.8 mol%. On the basis of the phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, a novel species Bacillus beringensis is proposed and the type strain is BR035(T) (=CGMCC 1.9126(T)=DSM 22571(T)).

  12. Experimental Induction of Bacterial Resistance to the Antimicrobial Peptide Tachyplesin I and Investigation of the Resistance Mechanisms.

    PubMed

    Hong, Jun; Hu, Jianye; Ke, Fei

    2016-10-01

    Tachyplesin I is a 17-amino-acid cationic antimicrobial peptide (AMP) with a typical cyclic antiparallel β-sheet structure that is a promising therapeutic for infections, tumors, and viruses. To date, no bacterial resistance to tachyplesin I has been reported. To explore the safety of tachyplesin I as an antibacterial drug for wide clinical application, we experimentally induced bacterial resistance to tachyplesin I by using two selection procedures and studied the preliminary resistance mechanisms. Aeromonas hydrophila XS91-4-1, Pseudomonas aeruginosa CGMCC1.2620, and Escherichia coli ATCC 25922 and F41 showed resistance to tachyplesin I under long-term selection pressure with continuously increasing concentrations of tachyplesin I. In addition, P. aeruginosa and E. coli exhibited resistance to tachyplesin I under UV mutagenesis selection conditions. Cell growth and colony morphology were slightly different between control strains and strains with induced resistance. Cross-resistance to tachyplesin I and antimicrobial agents (cefoperazone and amikacin) or other AMPs (pexiganan, tachyplesin III, and polyphemusin I) was observed in some resistant mutants. Previous studies showed that extracellular protease-mediated degradation of AMPs induced bacterial resistance to AMPs. Our results indicated that the resistance mechanism of P. aeruginosa was not entirely dependent on extracellular proteolytic degradation of tachyplesin I; however, tachyplesin I could induce increased proteolytic activity in P. aeruginosa Most importantly, our findings raise serious concerns about the long-term risks associated with the development and clinical use of tachyplesin I.

  13. Catellatospora tagetis sp. nov., isolated from the root of a marigold (Tagetes erecta L.).

    PubMed

    Zhou, Ying; Liu, Chongxi; Zhang, Yuejing; Zhao, Junwei; Li, Chuang; He, Hairong; Li, Jiansong; Wang, Xiangjing; Xiang, Wensheng

    2015-09-01

    A Gram-stain positive, non-motile, mesophilic actinomycete, designated strain NEAU-YJC4(T) was isolated from the root of a marigold (Tagetes erecta L.) collected in Heilongjiang Province, northeast China, and characterized using a polyphasic approach. Morphological and chemotaxonomic properties of strain NEAU-YJC4(T) were consistent with the description of the genus Catellatospora. 16S rRNA gene sequence similarity studies showed that strain NEAU-YJC4(T) belongs to the genus Catellatospora, being most closely related to Catellatospora bangladeshensis JCM 12949(T) (98.7 %). Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that strain NEAU-YJC4(T) formed a monophyletic clade with the closest relative. A combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-YJC4(T) can be distinguished from C. bangladeshensis JCM 12949(T). Therefore, it is proposed that strain NEAU-YJC4(T) represents a novel species of the genus Catellatospora, for which the name Catellatospora tagetis sp. nov. is proposed. The type strain is NEAU-YJC4(T) (=CGMCC 4.7176(T) = JCM 30053(T)). PMID:26111852

  14. A single desaturase gene from red yeast Sporidiobolus pararoseus is responsible for both four- and five-step dehydrogenation of phytoene.

    PubMed

    Li, Chunji; Zhang, Ning; Song, Jia; Wei, Na; Li, Bingxue; Zou, Hongtao; Han, Xiaori

    2016-09-15

    Carotenoids are one of the most common classes of natural pigments widely occurring within organisms. These structurally diverse pigments are of great importance in different processes such as nutrition, vision, cellular growth and development. While found in various yeast strains, one of the best-studied carotenoid producer is the pigmented species Sporidiobolus pararoseus. However, the precise nature of the genes involved in the biosynthesis of carotenoids in this species remains unclear. Here, we cloned a cDNA copy of the phytoene desaturase gene crtI from Sporidiobolus pararoseus CGMCC 2.5280. The crtI full-length genomic DNA and cDNA are 2330bp and 1683bp, respectively. This gene encodes a 560-amino acid protein with a predicted molecular mass of 62.28 kDa and a pI of 7.27. Functional identification of the gene was performed using heterologous complementation detection in Escherichia coli. Our experimental findings indicate that the enzymatic conversion of phytoene to lycopene (fourth step product) and 3,4-didehydrolycopene (fifth step product) is catalyzed by this phytoene desaturase of S. pararoseus through consecutive dehydrogenation. Furthermore, our findings suggest that the crtI gene of S. pararoseus represents an alternative gene source for the reconstruction of carotenogenic pathways vital for the production of engineered carotenoids. PMID:27346167

  15. Salisediminibacterium halotolerans gen. nov., sp. nov., a halophilic bacterium from soda lake sediment.

    PubMed

    Jiang, Feng; Cao, Shu-Juan; Li, Zhao-Hu; Fan, Hua; Li, Hai-Feng; Liu, Wei-Jie; Yuan, Hong-Li

    2012-09-01

    An orange-pigmented, Gram-reaction-positive, non-spore-forming, halophilic, alkali-tolerant rod, designated strain halo-2(T), was isolated from sediment of Xiarinaoer soda lake, in China's Inner Mongolia Autonomous Region. Strain halo-2(T) grew in a complex medium with 3-30 % (w/v) NaCl and at pH 5-10. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the major respiratory isoprenoid quinone was MK-7. The predominant cellular fatty acids were anteiso-C(15 : 0) (43.6 %), anteiso-C(17 : 0) (14.8 %) and iso-C(15 : 0) (6.8 %) and the polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The genomic DNA G+C content of the novel strain was 48.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain halo-2(T) was most closely related to Bacillus agaradhaerens DSM 8721(T) (93.9 % sequence similarity). However, strain halo-2(T) could be clearly differentiated from its closest phylogenetic relatives on the basis of several phenotypic, genotypic and chemotaxonomic characteristics. Strain halo-2(T) therefore represents a novel species in a new genus for which the name Salisediminibacterium halotolerans gen. nov., sp. nov. is proposed. The type strain of the type species is halo-2(T) (= CGMCC 1.7654(T) = NBRC 104935(T)). PMID:22039006

  16. 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 700μg 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.

  17. Nocardiopsis mangrovei sp. nov., isolated from mangrove sediment.

    PubMed

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

    2015-06-01

    Two Gram-positive actinobacterial strains, designated HA11166(T) and HA12420, were isolated from mangrove sediments in Hainan, China. The bacterial cells grew with 0-9 % (w/v) NaCl, at 15-40 °C and pH 5.0-10.0, with the optimum growth at 1 % NaCl, 30-37 °C and pH 7.0. The organisms had a range of chemical and morphological properties consistent with their classification in the genus Nocardiopsis. Phylogenetic analysis of the 16S rRNA gene sequences indicated that strains HA11166(T) and HA12420 can be affiliated to the genus Nocardiopsis and most closely related to Nocardiopsis trehalosi VKM Ac-942(T) (with the similarity of 97.2 and 97.5 %, respectively). The value of DNA-DNA relatedness between type strain HA11166(T), selected as the representative strain, and N. trehalosi VKM Ac-942(T) was 38.8 %. The DNA G+C content of strain HA11166(T) was 73.7 %. On the basis of these phenotypic and genotypic data, strains HA11166(T) and HA12420 are proposed to represent a novel species of the genus Nocardiopsis, for which the name Nocardiopsis mangrovei sp. nov. is proposed. The type strain is HA11166(T) (=CGMCC 4.7119(T)=DSM 46665(T)). PMID:25969384

  18. Streptomyces mangrovi sp. nov., an actinomycete from mangrove soil.

    PubMed

    Wang, Ying; Huang, Huiqin; Yuan, Weidao; Wei, Hua; Chen, Yuqing; Zhu, Jun; Liu, Min; Zou, Xiaoxiao; Bao, Shixiang

    2015-09-01

    A novel aerobic actinomycete, designated HA11110(T), was isolated from a mangrove soil sample collected in Haikou, China. It formed white aerial mycelium and pale yellow substrate mycelium on Gause's synthetic agar no. 1. Scanning electron microscopy revealed that cells of HA11110(T) produced straight to spiral spore chains with spiny spores. Chemotaxonomic tests showed that the cell wall contained LL-diaminopimelic acid and the major fatty acids were iso-C16 : 0, anteiso-C15 : 0 and iso-C14 : 0.16S rRNA gene sequence similarity showed that strain HA11110(T) belonged to the genus Streptomyces, most closely related to Streptomyces fenghuangensis GIMN4.003(T) (99.1%), Streptomyces nanhaiensis SCSIO 01248(T) (98.8%) and Streptomyces radiopugnans R97(T) (98.8%). However, DNA-DNA hybridization studies of strain HA11110T with these three closest relatives showed relatedness values of 58.4, 49.7 and 47.2%, respectively. On the basis of phenotypic and genotypic data, strain HA11110(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces mangrovi sp. nov. is proposed. The type strain is HA11110(T) ( = CGMCC 4.7117(T)= DSM 42113(T)). PMID:26297343

  19. Characterization of a novel β-cypermethrin-degrading Aspergillus niger YAT strain and the biochemical degradation pathway of β-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 β-cypermethrin (β-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 β-CY and 3-PBA range from 3.573 to 11.748 days and from 5.635 to 12.160 h, respectively. The degradation of β-CY and 3-PBA was further described using first-order kinetic models. The pathway and mechanism of β-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. β-CY degradation products were analyzed. Results indicated that YAT strain transformed β-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

  20. Micromonospora violae sp. nov., isolated from a root of Viola philippica Car.

    PubMed

    Zhang, Yuejing; Liu, Hui; Zhang, Xinhui; Wang, Shurui; Liu, Chongxi; Yu, Chao; Wang, Xiangjing; Xiang, Wensheng

    2014-08-01

    A novel actinomycete, designated strain NEAU-zh8(T), was isolated from a root of Viola philippica Car collected in China and characterized using a polyphasic approach. 16S rRNA gene sequence similarity studies showed that strain NEAU-zh8(T) belongs to the genus Micromonospora, being most closely related to Micromonospora chokoriensis 2-9(6)(T) (99.9 %), Micromonospora saelicesensis Lupac 09(T) (99.3 %) and Micromonospora lupini Lupac 14N(T) (99.0 %). gyrB gene analysis also indicated that strain NEAU-zh8(T) should be assigned to the genus Micromonospora. The cell-wall peptidoglycan consisted of meso-diaminopimelic acid and glycine. The major menaquinones were MK-10(H4), MK-10(H2) and MK-10(H6). The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were iso-C15:0, C16:0 and C17:0 10-methyl. A combination of DNA-DNA hybridization results and some physiological and biochemical properties indicated that strain NEAU-zh8(T) could be readily distinguished from the closest phylogenetic relatives. Therefore, it is proposed that strain NEAU-zh8(T) represents a novel Micromonospora species, for which the name Micromonospora violae sp. nov. is proposed. The type strain is NEAU-zh8(T) (=CGMCC 4.7102(T)=DSM 45888(T)).

  1. Enterococcus Xinjiangensis sp. nov., Isolated from Yogurt of Xinjiang, China.

    PubMed

    Ren, Xiaopu; Li, Mingyang; Guo, Dongqi

    2016-09-01

    A Gram-strain-positive bacterial strain 48(T) was isolated from traditional yogurt in Xinjiang Province, China. The bacterium was characterized by a polyphasic approach, including 16S rRNA gene sequence analysis, polymerase α subunit (rpoA) gene sequence analysis, determination of DNA G+C content, DNA-DNA hybridization with the type strain of Enterococcus ratti and analysis of phenotypic features. Strain 48(T) accounted for 96.1, 95.8, 95.8, and 95.7 % with Enterococcus faecium CGMCC 1.2136(T), Enterococcus hirae ATCC 9790(T), Enterococcus durans CECT 411(T), and E. ratti ATCC 700914(T) in the 16S rRNA gene sequence similarities, respectively. The sequence of rpoA gene showed similarities of 99.0, 96.0, 96.0, and 96 % with that of E. faecium ATCC 19434(T), Enterococcus villorum LMG12287, E. hirae ATCC 9790(T), and E. durans ATCC 19432(T), respectively. Based upon of polyphasic characterization data obtained in the study,