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Sample records for stenotrophomonas maltophilia cgmcc

  1. Genetic Manipulation of Stenotrophomonas maltophilia.

    PubMed

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

    2015-01-01

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

  2. 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

  3. Stenotrophomonas maltophilia: Complicating treatment of ESBL UTI

    PubMed Central

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

    2015-01-01

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

  4. Stenotrophomonas maltophilia: Complicating treatment of ESBL UTI.

    PubMed

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

    2015-01-01

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

  5. 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

  6. Structure of aminodeoxychorismate synthase from Stenotrophomonas maltophilia.

    PubMed

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

    2012-12-21

    PabB, aminodeoxychorismate synthase, is the chorismic acid binding component of the heterodimeric PabA-PabB 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 C4 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 allow discrimination of 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 2 equiv of ammonia from glutamine and that feature a noncovalently bound 2-amino-2-deoxyisochorismate intermediate was recently identified. Here we report the 2.25 crystal structure of PabB from the emerging pathogen Stenotrophomonas maltophilia. It is the first reported structure of a PabB that features the PIAGT motif. Surprisingly, no dedicated pabA is evident in the genome of S. maltophilia, suggesting that another cellular amidotransferase is able to fulfill the role of PabA in this organism. Evaluation of the ammonia-dependent aminodeoxychorismate synthase activity of S. maltophilia PabB alone revealed that it is virtually inactive. However, in the presence of a heterologous PabA surrogate, typical levels of activity were observed using either glutamine or ammonia as the nitrogen source. Additionally, the structure suggests that a key segment of the polypeptide can remodel itself to interact with a nonspecialized or shared amidotransferase partner in vivo. The structure and mass spectral analysis further suggest that S. maltophilia PabB, like Escherichia coli PabB, binds tryptophan in a vestigial regulatory site. The observation that the binding site is unoccupied in the crystal structure, however, suggests the affinity may be low relative to that of E. coli PabB. PMID:23230967

  7. Meningitis due to Stenotrophomonas maltophilia after a Neurosurgical Procedure

    PubMed Central

    Sood, Smita; Vaid, Vivek Kumar; Bhartiya, Hemant

    2013-01-01

    Stenotrophomonas maltophilia is an aerobic, glucose non- fermentative, gram negative bacillus, which is being increasingly recognized as a cause of serious infections such as bacteraemia, urinary tract infections, respiratory tract infections, skin and soft tissue infections, endocarditis, meningitis and ocular infections in hospitalized patients. The treatment of invasive S. maltophilia infections is difficult, as this pathogen shows high levels of intrinsic or acquired resistance to different antibiotics, thus reducing the options which are available for treatment. Meningitiscaused by S. maltophilia is rarely encountered and so its experience is also limited. We are describing here a case of a six months old, male child who developed meningitis caused by Stenotrophomonas maltophilia, after he underwent a neurosurgical procedure. PMID:24086879

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

    PubMed

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

    2010-01-01

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

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

    PubMed

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

    2015-05-01

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

  10. 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

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

    PubMed Central

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

    2015-01-01

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

  12. Antifolate Activity of Epigallocatechin Gallate against Stenotrophomonas maltophilia

    PubMed Central

    Navarro-Martnez, Mara Dolores; Navarro-Pern, Enma; Cabezas-Herrera, Juan; Ruiz-Gmez, Joaqun; Garca-Cnovas, Francisco; Rodrguez-Lpez, Jos Neptuno

    2005-01-01

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

  13. 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 (464 g/mL) than in the surviving group (14 g/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

  14. Antibiotic resistance in the opportunistic pathogen Stenotrophomonas maltophilia

    PubMed Central

    Sánchez, María B.

    2015-01-01

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

  15. 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

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

    PubMed Central

    Huedo, Pol; Conchillo-Sol, scar; Yero, Daniel; Martnez-Servat, Snia

    2014-01-01

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

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

    PubMed

    Huedo, Pol; Conchillo-Sol, Oscar; Yero, Daniel; Martnez-Servat, Snia; Daura, Xavier; Gibert, Isidre

    2014-01-01

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

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

    PubMed

    Sánchez, María Blanca; Martínez, José Luis

    2015-07-01

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

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

    PubMed Central

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

    2015-01-01

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

  20. L-glucitol catabolism in Stenotrophomonas maltophilia Ac.

    PubMed

    Brechtel, Elke; Huwig, Alexander; Giffhorn, Friedrich

    2002-02-01

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

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

    PubMed

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

    2009-07-01

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

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

    PubMed

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

    1998-05-01

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

  3. 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

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

    PubMed Central

    Conchillo-Sol, Oscar; Yero, Daniel; Coves, Xavier; Huedo, Pol; Martnez-Servat, Snia

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  6. 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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  9. 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

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

    PubMed

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

    2016-01-01

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

  11. Diffusible Signal Factor-Dependent Cell-Cell Signaling and Virulence in the Nosocomial Pathogen Stenotrophomonas maltophilia?

    PubMed Central

    Fouhy, Yvonne; Scanlon, Karl; Schouest, Katherine; Spillane, Charles; Crossman, Lisa; Avison, Matthew B.; Ryan, Robert P.; Dow, J. Maxwell

    2007-01-01

    The genome of Stenotrophomonas maltophilia encodes a cell-cell signaling system that is highly related to the diffusible signal factor (DSF)-dependent system of the phytopathogen Xanthomonas campestris. Here we show that in S. maltophilia, DSF signaling controls factors contributing to the virulence and antibiotic resistance of this important nosocomial pathogen. PMID:17468254

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

    PubMed Central

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

    2014-01-01

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

  13. 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

  14. 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

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

    PubMed

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

    2015-01-01

    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

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

    PubMed

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

    2003-09-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2015-01-01

    Stenotrophomonas maltophilia is a Gram-negative, biofilm-forming bacterium. Although generally regarded as an organism of low virulence, S. maltophilia is an emerging multi-drug resistant opportunistic pathogen in hospital and community settings, especially among immunocompromised hosts. Risk factors associated with S. maltophilia infection include underlying malignancy, cystic fibrosis, corticosteroid or immunosuppressant therapy, the presence of an indwelling central venous catheter and exposure to broad spectrum antibiotics. In this review, we provide a synthesis of information on current global trends in S. maltophilia pathogenicity as well as updated information on the molecular mechanisms contributing to its resistance to an array of antimicrobial agents. The prevalence of S. maltophilia infection in the general population increased from 0.8–1.4% during 1997–2003 to 1.3–1.68% during 2007–2012. The most important molecular mechanisms contributing to its resistance to antibiotics include 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

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

    PubMed

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

    2015-08-01

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

  20. 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 ?-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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2012-12-01

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

  3. Complete Genome Sequence of IME15, the First T7-Like Bacteriophage Lytic to Pan-Antibiotic-Resistant Stenotrophomonas maltophilia

    PubMed Central

    Huang, Yong; Fan, Huahao; Pei, Guangqian; Fan, Hang; Zhang, Zhiyi; An, Xiaoping; Mi, Zhiqiang

    2012-01-01

    T7-like bacteriophages are a class of virulent bacteriophages which have a clearer genetic background and smaller genomes than other phages. In addition, it grows faster and is easier to culture than other phages. At present, the numbers of available T7-like bacteriophage genomes and Stenotrophomonas maltophilia genomes are small, and IME15 is the first T7-like virulent Stenotrophomonas phage whose sequence has been reported. It shows effective lysis of S. maltophilia. Here we announce its complete genome, and major findings from its annotation are described. PMID:23166248

  4. SmeOP-TolCSm efflux pump contributes to the multidrug resistance of Stenotrophomonas maltophilia.

    PubMed

    Lin, Cheng-Wen; Huang, Yi-Wei; Hu, Rouh-Mei; Yang, Tsuey-Ching

    2014-01-01

    A five-gene cluster, tolCSm-pcm-smeRo-smeO-smeP, of Stenotrophomonas maltophilia was characterized. The presence of smeOP and smeRo-pcm-tolCSm operons was verified by reverse transcription (RT)-PCR. Both operons were negatively regulated by the TetR-type transcriptional regulator SmeRo, as demonstrated by quantitative RT-PCR and a promoter-fusion assay. SmeO and SmeP were associated with TolCSm (the TolC protein of S. maltophilia) for the assembly of a resistance-nodulation-cell-division (RND)-type pump. The compounds extruded by SmeOP-TolCSm mainly included nalidixic acid, doxycycline, amikacin, gentamicin, erythromycin, leucomycin, carbonyl cyanide 3-chlorophenylhydrazone, crystal violet, sodium dodecyl sulfate, and tetrachlorosalicylanilide. PMID:24395237

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

    PubMed

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

    2015-03-01

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

  6. 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.

  7. 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.

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

    PubMed

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

    2016-03-01

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

  9. 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

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

    PubMed Central

    2012-01-01

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

  11. Phenotypic Heterogeneity Affects Stenotrophomonas maltophilia K279a Colony Morphotypes and ?-Lactamase Expression.

    PubMed

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

    2015-01-01

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

  12. The DSF quorum sensing system controls the positive influence of Stenotrophomonas maltophilia on plants.

    PubMed

    Alavi, Peyman; Mller, Henry; Cardinale, Massimiliano; Zachow, Christin; Snchez, Mara B; Martnez, Jos 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

  13. 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

  14. An Inducible Fusaric Acid Tripartite Efflux Pump Contributes to the Fusaric Acid Resistance in Stenotrophomonas maltophilia

    PubMed Central

    Hu, Rouh-Mei; Liao, Sih-Ting; Huang, Chiang-Ching; Huang, Yi-Wei; Yang, Tsuey-Ching

    2012-01-01

    Background Fusaric acid (5-butylpicolinic acid), a mycotoxin, is noxious to some microorganisms. Stenotrophomonas maltophilia displays an intrinsic resistance to fusaric acid. This study aims to elucidate the mechanism responsible for the intrinsic fusaric acid resistance in S. maltophilia. Methodology A putative fusaric acid resistance-involved regulon fuaR-fuaABC was identified by the survey of the whole genome sequence of S. maltophilia K279a. The fuaABC operon was verified by reverse transcriptase-PCR. The contribution of the fuaABC operon to the antimicrobial resistance was evaluated by comparing the antimicrobials susceptibility between the wild-type strain and fuaABC knock-out mutant. The regulatory role of fuaR in the expression of the fuaABC operon was assessed by promoter transcription fusion assay. Results The fuaABC operon was inducibly expressed by fusaric acid and the inducibility was fuaR dependent. FuaR functioned as a repressor of the fuaABC operon in absence of a fusaric acid inducer and as an activator in its presence. Overexpression of the fuaABC operon contributed to the fusaric acid resistance. Significance A novel tripartite fusaric acid efflux pump, FuaABC, was identified in this study. Distinct from the formally classification, the FuaABC may constitute a new type of subfamily of the tripartite efflux pump. PMID:23236431

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

    PubMed

    Baranzelli, A; Wallyn, F; Nseir, S

    2013-10-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  18. 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

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

    PubMed

    Garca, 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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2003-06-01

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

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

    PubMed

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

    2015-11-01

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

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

    PubMed Central

    MacDonald, Logan C.; Berger, Bryan W.

    2014-01-01

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

  5. 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

  6. 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

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

    PubMed

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

    2015-01-01

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

  8. 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; Snchez, Maria B.; Martnez, Jose L.

    2015-01-01

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

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed

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

    2015-09-01

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

  11. 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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

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

    2016-02-01

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

  14. 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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

    Adegoke, Anthony Ayodeji; Okoh, Anthony I.

    2014-01-01

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

  17. Extracellular serine proteases from Stenotrophomonas maltophilia: Screening, isolation and heterologous expression in E. coli.

    PubMed

    Ribitsch, D; Heumann, S; Karl, W; Gerlach, J; Leber, R; Birner-Gruenberger, R; Gruber, K; Eiteljoerg, I; Remler, P; Siegert, P; Lange, J; Maurer, K H; Berg, G; Guebitz, G M; Schwab, H

    2012-01-01

    A large strain collection comprising antagonistic bacteria was screened for novel detergent proteases. Several strains displayed protease activity on agar plates containing skim milk but were inactive in liquid media. Encapsulation of cells in alginate beads induced protease production. Stenotrophomonas maltophilia emerged as best performer under washing conditions. For identification of wash-active proteases, four extracellular serine proteases called StmPr1, StmPr2, StmPr3 and StmPr4 were cloned. StmPr2 and StmPr4 were sufficiently overexpressed in E. coli. Expression of StmPr1 and StmPr3 resulted in unprocessed, insoluble protein. Truncation of most of the C-terminal domain which has been identified by enzyme modeling succeeded in expression of soluble, active StmPr1 but failed in case of StmPr3. From laundry application tests StmPr2 turned out to be a highly wash-active protease at 45C. Specific activity of StmPr2 determined with suc-L-Ala-L-Ala-L-Pro-l-Phe-p-nitroanilide as the substrate was 172U/mg. In addition we determined the kinetic parameters and cleavage preferences of protease StmPr2. PMID:21983234

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

    PubMed

    Jankiewicz, Urszula; Brzezinska, Maria Swiontek

    2015-06-01

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

  19. 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

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

    PubMed

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

    2015-05-01

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

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

    PubMed

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

    2015-09-01

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

  2. 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

  3. 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

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

    PubMed

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

    2015-01-01

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

  5. Prevalence and detection of Stenotrophomonas maltophilia carrying metallo-?-lactamase blaL1 in Beijing, China

    PubMed Central

    Yang, Zhan; Liu, Wei; Cui, Qian; Niu, Wenkai; Li, Huan; Zhao, Xiangna; Wei, Xiao; Wang, Xuesong; Huang, Simo; Dong, Derong; Lu, Sijing; Bai, Changqing; Li, Yan; Huang, Liuyu; Yuan, Jing

    2014-01-01

    Intrinsic ?-lactam resistance in Stenotrophomonas maltophilia is caused by blaL1 and/or blaL2, a kind of metallo-?-lactamase with a broad substrate spectrum including carbapenems. A rapid and sensitive molecular method for the detection of blaL1 in clinical samples is needed to guide therapeutic treatment. In present study, we first described a loop-mediated isothermal amplification (LAMP) method for the rapid detection of blaL1 in clinical samples by using two methods including a chromogenic method using calcein/Mn2+ complex and the real-time turbidity monitoring to assess the reaction. Then dissemination of L1-producing S. maltophilia was investigated from ICU patients in three top hospital in Beijing, China. The results showed that both methods detected the target DNA within 60 min under isothermal conditions (65C). The detection limit of LAMP was 3.79 pg/?l DNA, and its sensitivity 100-fold greater than that of conventional PCR. All 21 test strains except for S. maltophilia were negative for blaL1, indicative of the high-specificity of the primers for the blaL1. A total of 22 L1-positive isolates were identified for LAMP-based surveillance of blaL1 from 105 ICU patients with clinically suspected multi-resistant infections. The sequences of these blaL1 genes were conservative with only a few sites mutated, and the strains had highly resistant to ?-lactam antibiotics. The MLST recovered that 22 strains belonged to seven different S. maltophilia sequence types (STs). Furthermore, co-occurrence of blaL1 and blaL2 genes were detected in all of isolates. Strikingly, S. maltophilia DCPS-01 was recovered to contain blaL1, blaL2, and blaNDM-1 genes, possessing an ability to hydrolyse all ?-lactams antibiotics. Our data showed the diversity types of S. maltophilia carrying blaL1 and co-occurrence of many resistant genes in the clinical strains signal an ongoing and fast evolution of S. maltophilia resulting from their wide spread in the respiratory infections, and therefore will be difficult to control. PMID:25538701

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

    PubMed Central

    Berg, Gabriele; Martinez, Jose L.

    2015-01-01

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

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

    PubMed

    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

  8. Crystallization of the N-terminal regulatory domain of the enhancer-binding protein FleQ from Stenotrophomonas maltophilia

    PubMed Central

    Yang, Jauo-Guey; Shih, Min-Shao; Kuo, Wei-Ting; Chin, Ko-Hsin; Shen, Gwan-Han; Chou, Shan-Ho

    2014-01-01

    FleQ is a master regulator that controls bacterial flagellar gene expression. It is a unique enhancer-binding protein or repressor protein comprising an N-terminal FleQ domain, an AAA+/ATPase ?54-interaction domain and a helixturnhelix DNA-binding domain. FleN is a putative ATPase with a deviant Walker A motif that works together with FleQ by binding to the FleQ N-terminal domain to fully express pel, psl and cdr operons in the presence of c-di-GMP to enhance biofilm formation. Stenotrophomonas maltophilia is an emerging human pathogen that causes fatal infections in humans. In order to understand the interaction between the FleN and FleQ domains and its effect on S. maltophilia biofilm formation, determination of the FleQc-di-GMP and FleNFleQc-di-GMP complex structures was embarked upon. Towards this goal, the FleQ N-terminal domain from S. maltophilia was first cloned and expressed in Escherichia coli. Native and SeMet-labelled FleQ domains were successfully crystallized and diffracted to resolutions of 2.08 and 2.58?, respectively. PMID:24598919

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    1998-01-01

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

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

    PubMed

    Garca-Len, Guillermo; Hernndez, Alvaro; Hernando-Amado, Sara; Alavi, Peyman; Berg, Gabriele; Martnez, Jos 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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

    Kaur, Parvinder; Gautam, Vikas; Tewari, Rupinder

    2015-08-01

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

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

    PubMed Central

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

    2015-01-01

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

  15. 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

  16. 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

  17. 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

  18. 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 45C. Thermostability assays showed that endolysin P28 was stable up to 50C, while its residual activity was reduced by 55% after treatment at 70C 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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

    Snchez, Mara B; Hernndez, Alvaro; Rodrguez-Martnez, Jos M; Martnez-Martnez, Luis; Martnez, Jos 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

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

    PubMed Central

    Minkwitz, Arite; Berg, Gabriele

    2001-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2005-09-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    SciTech Connect

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

    2006-01-01

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

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

    PubMed

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

    2013-01-01

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

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

    PubMed

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

    2015-06-01

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

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

    PubMed

    Prez, Pablo N; Ramrez, Mara A; Fernndez, Jos A; de Guevara, Laura Ladrn

    2014-05-13

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

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

    PubMed

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

    2015-09-01

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

  13. 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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2007-01-01

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

  16. 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. PMID:24603491

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

    PubMed

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

    2015-07-01

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

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

    PubMed Central

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

    2015-01-01

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

  19. Modification of surface and enzymatic properties of Achromobacter denitrificans and Stenotrophomonas maltophilia in association with diesel oil biodegradation enhanced with alkyl polyglucosides.

    PubMed

    Sa?ek, Karina; Zgo?a-Grze?kowiak, Agnieszka; Kaczorek, Ewa

    2013-11-01

    The article concerns the influence of selected alkyl polyglucosides on biodegradation, cell surface and enzymatic properties of Stenotrophomonas maltophilia and Achromobacter denitrificans. The biodegradation of diesel oil depends on several factors including type and the amount of surfactant as well as bacterial genera used in the process. Nevertheless, a careful selection of these variables must be made as some bacterial strains prefer to use surfactants as their carbon source. This leads to the lowered biodegradation of diesel oil as can be observed for the tested S. maltophilia strain. Alkyl polyglucosides influenced the cell surface properties of both of the tested strains in slightly different ways. Especially for A. denitrificans, for which the hydrophobicity increased with concentration of both--Lutensol GD 70 and Glucopon 215 in diesel oil-surfactant systems. Moreover, judging by the efficiency of biodegradation, the most effective process was observed in the presence of Lutensol GD 70 (240 and 360 mg L(-1)) with biodegradation rising from 32% (without surfactant) to 68%. No such relation was observed for S. maltophilia. PMID:23777790

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

    PubMed Central

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

    2013-01-01

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

  1. 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; Garca, Carlos; Alcaraz, Eliana; Franco, Mirta

    2014-01-01

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

  2. 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

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

    PubMed

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

    2015-01-01

    Outer membrane vesicles (OMVs) are small nanoscale structures that are secreted by bacteria and that can carry nucleic acids, proteins, and small metabolites. They can mediate intracellular communication and play a role in virulence. In this study, we show that treatment with the ?-lactam antibiotic imipenem leads to a dramatic increase in the secretion of outer membrane vesicles in the nosocomial pathogen Stenotrophomonas maltophilia. Proteomic analysis of their protein content demonstrated that the OMVs contain the chromosomal encoded L1 metallo-?-lactamase and L2 serine-?-lactamase. Moreover, the secreted OMVs contain large amounts of two Ax21 homologs, i.e., outer membrane proteins known to be involved in virulence and biofilm formation. We show that OMV secretion and the levels of Ax21 in the OMVs are dependent on the quorum sensing diffusible signal system (DSF). More specific, we demonstrate that the S. maltophilia DSF cis-?2-11-methyl-dodecenoic acid and, to a lesser extent, the Burkholderia cenocepacia DSF cis-?2-dodecenoic acid, stimulate OMV secretion. By a targeted proteomic analysis, we confirmed that DSF-induced OMVs contain large amounts of the Ax21 homologs, but not the ?-lactamases. This work illustrates that both quorum sensing and disturbance of the peptidoglycan biosynthesis provoke the release of OMVs and that OMV content is context dependent. PMID:25926824

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

    PubMed

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

    2015-10-01

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

  5. The binding of triclosan to SmeT, the repressor of the multidrug efflux pump SmeDEF, induces antibiotic resistance in Stenotrophomonas maltophilia.

    PubMed

    Hernndez, Alvaro; Ruiz, Federico M; Romero, Antonio; Martnez, Jos L

    2011-06-01

    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

  6. 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

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

    PubMed Central

    Cai, Xuejiu; Zhao, Jin; Cui, Junchang

    2016-01-01

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

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

    PubMed Central

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

    2007-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

    2012-01-01

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

  11. 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

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

    PubMed

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

    2015-11-01

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

  13. 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...

  14. 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.

  15. Occurrence and antagonistic potential of Stenotrophomonas strains isolated from deep-sea invertebrates.

    PubMed

    Romanenko, Lyudmila A; Uchino, Masataka; Tanaka, Naoto; Frolova, Galina M; Slinkina, Natalia N; Mikhailov, Valery V

    2008-04-01

    Stenotrophomonas maltophilia is known to be of significance as opportunistic pathogen as well as a source of biocontrol and bioremediation activities. S. maltophilia strains have been isolated from rhizospheres, soil, clinical material, aquatic habitats, but little is known about Stenotrophomonas strains recovered from marine environments. During a survey of the biodiversity of Pseudomonas-like bacteria associated with deep-sea invertebrates six Stenotrophomonas strains were isolated from sponge, sea urchin, and ophiura specimens collected from differing Pacific areas, including the Philippine Sea, the Fiji Sea and the Bering Sea. 16S rRNA gene sequence analysis confirmed an assignment of marine isolates to the genus Stenotrophomonas as it placed four strains into the S. maltophilia CIP 60.77T cluster and two related to the S. rhizophila DSM 14405T. Together with a number of common characteristics typical of S. maltophilia and S. rhizophila marine isolates exhibited differences in pigmentation, a NaCl tolerance, a range of temperatures, which supported their growth, substrate utilization pattern, and antibiotics resistance. Strains displayed hemolytic and remarkable inhibitory activity against a number of fungal cultures and Gram-positive microorganisms, but very weak or none against Candida albicans. This is the first report on isolation, taxonomic characterization and antimicrobial activity of Stenotrophomonas strains isolated from deep-sea invertebrates. PMID:18034228

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2010-03-01

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

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

    PubMed

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

    2015-10-01

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

  19. Meningitis due to Xanthomonas maltophilia.

    PubMed

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

    1993-01-01

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

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

    PubMed Central

    2014-01-01

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

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

    PubMed

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

    2013-11-01

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

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

    PubMed Central

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

    2013-01-01

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

  3. Serological classification of Xanthomonas maltophilia (Pseudomonas maltophilia) based on heat-stable O antigens.

    PubMed Central

    Schable, B; Rhoden, D L; Hugh, R; Weaver, R E; Khardori, N; Smith, P B; Bodey, G P; Anderson, R L

    1989-01-01

    Twenty-six serotypes of Xanthomonas maltophilia were defined by using 15 antisera described by Hugh and Ryschenkow (R. Hugh and E. Ryschenkow, J. Gen. Microbiol. 26:123-132, 1961) and 11 new antisera. The antisera were prepared by immunizing rabbits with bacterial strains heated at 100 degrees C for 2 h. Twelve antisera required adsorptions with cross-reacting heterologous immunizing strains. We tested 275 clinical and environmental strains of X. maltophilia with 26 antisera by the slide agglutination technique. A total of 259 (94.2%) strains were typeable, with 137 (49.8%) strains agglutinating in three antisera. PMID:2473089

  4. Production of poly(3-hydroxybutyrate- co-3-hydroxyhexanoate) with flexible 3-hydroxyhexanoate content in Aeromonas hydrophila CGMCC 0911.

    PubMed

    Lu, X Y; Wu, Q; Chen, G Q

    2004-03-01

    Aeromonas hydrophila CGMCC 0911 isolated from lake water was found to be able to synthesize a polyhydroxyalkanoate (PHA) copolymer (PHBHHx) consisting of 3-hydroxybutyrate (HB) and 4-6 mol% 3-hydroxyhexanoate (HHx). The wild-type bacterium accumulated 49% PHBHHx containing 6 mol% HHx in terms of cell dry weight (CDW) when grown on lauric acid for 48 h. When A. hydrophila CGMCC 0911 expressed the Acyl-CoA dehydrogenase gene ( yafH) of Escherichia coli, the recombinant strain could accumulate 47% PHBHHx, while the HHx content reached 17.4 mol%. The presence of changing glucose concentration in the culture changed the HHx content both in wild type and recombinant A. hydrophila CGMCC 0911. When 5 g l(-1) glucose was added to a culture containing 5 g l(-1) lauric acid as co-substrate, 45% PHBHHx/CDW consisting of 8.8 mol% HHx was produced by wild-type A. hydrophila CGMCC 0911 compared with only 5% in the absence of glucose. When the recombinant A. hydrophila CGMCC 0911 was grown on a mixed substrate containing lauric acid and 8-10 g l(-1) glucose, the HHx content could be further increased to 35.6 mol%. When the glucose concentration exceeded 10 g l(-1), cell growth, PHA content and mole percentages of HHx in PHBHHx were significantly reduced. PMID:12920488

  5. Complete genome sequence of a benzo[a]pyrene-degrading bacterium Altererythrobacter epoxidivorans CGMCC 1.7731(T).

    PubMed

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

    2016-02-01

    Altererythrobacter epoxidivorans CGMCC 1.7731(T) is a Gram-negative bacterium isolated from marine sediments. It is able to utilize benzo[a]pyrene as sole carbon and energy source. Here, we describe the complete genome sequence and annotation of A. epoxidivorans CGMCC 1.7731(T). The genome has a size of 2,786,256bp (61.50mol% G+C content), which consists of 2773 coding genes, 43 tRNA genes and 3 rRNA genes. According to the genome information, strain A. epoxidivorans CGMCC 1.7731(T) encodes 22 genes related to degradation of benzo[a]pyrene. These genes may have potential in bioremediation of PAH-polluted environments. PMID:26655255

  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. PMID:26428132

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

    PubMed

    Abbott, Iain J; Peleg, Anton Y

    2015-02-01

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

  8. 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

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

    PubMed

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

    2015-06-01

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

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

    TOXLINE Toxicology Bibliographic Information

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

    2015-06-01

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

  11. Digestion of algin by Pseudomonas maltophilia and Pseudomonas putida.

    PubMed Central

    von Riesen, V L

    1980-01-01

    Pseudomonas maltophilia and Pseudomonas putida were identified as alginolytic species. Two media used for demonstrating alginolytic activity are described. The applied aspects of the ability of these two species to digest algin are discussed. PMID:7356324

  12. Specific gonadotropin binding to Pseudomonas maltophilia.

    PubMed

    Richert, N D; Ryan, R J

    1977-03-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2001-07-01

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

  16. Enhancement of enzyme activity and enantioselectivity via cultivation in nitrile metabolism by Rhodococcus sp. CGMCC 0497.

    PubMed

    Wu, Zhong-Liu; Li, Zu-Yi

    2002-02-01

    Racemic 2-phenylpropionitrile was resolved enantioselectively by nitrile-converting enzymes in cells of Rhodococcus sp. CGMCC 0497 to S-(+)-2-phenylpropionic acid and R-(-)-2-phenylpropionamide. By optimization of the culture conditions, great enhancement of enzyme activity and enantioselectivity was achieved. Furthermore, the relationship between cell-growth periodicity and enzyme accumulation was studied; the addition of inducer was delayed by 1 day and the reaction was further improved. This unusual strategy has almost never been reported with other nitrile-converting strains. The resulting culture broth, containing methacrylamide as the inducer, beef extract as the nitrogen source and glucose as the carbon source, with methacrylamide added 24 h later, seemed to be most suitable. S-(+)-2-Phenylpropionic acid and R-(-)-2-phenylpropionamide were produced with yields of 48% (enantiomeric excess, 96%) and 42% (enantiomeric excess, 97%) respectively with no nitrile left after 3 h, or with yields of 52% and 39% (enantiomeric excess, 93% and 99%) respectively after 6 h. PMID:11834131

  17. Genome sequencing and annotation of Stenotrophomonas sp. SAM8

    PubMed Central

    Selim, Samy; Hassan, Sherif; Hagagy, Nashwa

    2015-01-01

    We report draft genome sequence of Stenotrophomonas sp. strain SAM8, isolated from environmental water. The draft genome size is 3,665,538bp with a G+C content of 67.2% and contains 6 rRNA sequence (single copies of 5S, 16S & 23S rRNA). The genome sequence can be accessed at DDBJ/EMBL/GenBank under the accession no. LDAV00000000. PMID:26697323

  18. Rhamsan gum production by Sphingomonas sp. CGMCC 6833 using a two-stage agitation speed control strategy.

    PubMed

    Xu, Xiao Ying; Zhu, Ping; Li, Sha; Chen, Xiao Ye; Jiang, Xing Huan; Xu, Hong

    2013-12-19

    Varying the agitation speed could greatly affect rhamsan gum production by Sphingomonas sp. CGMCC 6833. Batch fermentations at agitation speeds of 400, 600, 800, and 1,000rpm were therefore carried out. The time course of specific cell growth rate, specific glucose consumption rate, and specific rhamsan gum formation rate was subsequently determined. Based on the results, a novel two-stage agitation speed control strategy was developed. From 0 to 13H, the high specific cell growth and glucose consumption rates were achieved by setting the agitation speed of the fermenter at 800rpm. From 13H onward to the end of fermentation, the glucose consumption rate and specific cell growth rate were high at the agitation speed of 600rpm. Using this method, the maximum concentration and productivity of rhamsan gum reached 21.631.76gL(-1) and 0.3380.028gL(-1) H(-1) , respectively, which were both higher than the optimum results obtained at constant agitation speeds. PMID:24354661

  19. 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 3.536.41 fold higher enzymatic activity was obtained from mutant strain compared with parent strain. PMID:24901455

  20. Revealing differences in metabolic flux distributions between a mutant strain and its parent strain Gluconacetobacter xylinus CGMCC 2955.

    PubMed

    Zhong, Cheng; Li, Fei; 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

  1. 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.

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

    PubMed Central

    Krysiak, Marta

    2014-01-01

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

  3. 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

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

    PubMed Central

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

    2015-01-01

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

  5. 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

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

    PubMed

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

    2011-10-01

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

  7. 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

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

    PubMed

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

    2015-07-01

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

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

    PubMed

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

    2016-05-01

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

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

    PubMed Central

    Saino, Y; Inoue, M; Mitsuhashi, S

    1984-01-01

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

  11. 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.

  12. Physiological studies of the regulation of beta-lactamase expression in Pseudomonas maltophilia.

    PubMed Central

    Rosta, S; Mett, H

    1989-01-01

    The kinetics of beta-lactamase induction in Pseudomonas maltophilia IID1275/873 were investigated. Upon induction with beta-lactam antibiotics, a correlation was seen between the increase in specific beta-lactamase activity and the generation time, as well as the concentration of inducer in the medium. The specific beta-lactamase activity increased slowly within the first 0.5 generation and then more rapidly; it decreased regularly after about 2 generations of growth in the presence of inducer. This decrease could presumably be attributed to the continuous breakdown of inducer by beta-lactamases in the culture medium. In a chemostat culture with continuous supply of fresh inducer-containing medium, the specific beta-lactamase activity could be stabilized at a high level over several generations. Removal of the beta-lactam after a certain induction time showed that a short exposure of the bacteria to inducer caused induction kinetics comparable to those resulting from continuous exposure of the cells to inducer. The two beta-lactamases of P. maltophilia, L1 and L2, were induced simultaneously under various experimental conditions. PMID:2783690

  13. 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

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

    PubMed

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

    2011-02-01

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

  15. Evaluation of genetic and functional diversity of Stenotrophomonas isolates from diverse effluent treatment plants.

    PubMed

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

    2010-10-01

    In this study, the samples were collected from nine ETPs and soil contaminated with petroleum products. The genetic diversity of 30 Stenotrophomonas isolates was demonstrated by phylogenetic analysis of their 16S rRNA gene nucleotide sequences, and randomly amplified polymorphic DNA (RAPD) analysis supplemented with in silico signature and restriction enzyme (REs--AluI, BfaI, DpnII, HaeIII, RsaI and Tru9I) digestion analyses. Genetic diversity based on nucleotide sequence data revealed distinct clusters. Functional diversity was analysed on the basis of the abilities of these isolates to degrade phenol, p-cresol, catechol, 4-methylcatechol and hydroquinone. Based on the environmental, genetic and functional diversities, a consortium of mixed defined microbes has been proposed for bioremediation programs. PMID:20554196

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

    PubMed

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

    2013-09-28

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

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

    PubMed

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

    2000-10-01

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

  18. 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.

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

    SciTech Connect

    Su, J.J.

    1994-01-01

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

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

    PubMed

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

    2009-12-01

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  3. 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

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

    PubMed

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

    2016-01-01

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

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

    PubMed

    Gunasundari, Dharmaraj; Muthukumar, Karuppan

    2013-09-01

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

  6. 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

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

    PubMed Central

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

    2010-01-01

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

  8. 77 FR 41356 - Monsanto Co.; Availability of Petition for Determination of Nonregulated Status of Soybean...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... in the Federal Register (77 FR 13258-13260, Docket No. APHIS-2011-0129) a notice \\1\\ describing our... Stenotrophomonas maltophilia that expresses a monooxygenase enzyme that rapidly demethylates dicamba rendering...

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

    PubMed Central

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

    1999-01-01

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

  10. 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 200mg/l within 6h under optimum static conditions (temperature -35C, pH8, and initial cell concentration 7??10(7) cell/ml). Drastic reduction in dye degradation rate was observed beyond initial dye concentration from 500mg/l (90%), and it reaches to 25% at 1000mg/l under same set of conditions. The analysis related to decolorization and degradation was done using UV-Vis spectrophotometer, HPLC, and FTIR, whereas the GC-MS technique was utilized for the identification of degradation products. Phytotoxicity analysis revealed that degradation products are less toxic as compared to the original dye. PMID:25813637

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

    PubMed

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

    2011-04-01

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

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

    PubMed

    Vinuesa, Pablo; Ochoa-Snchez, Luz Edith

    2015-01-01

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

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

    PubMed Central

    Ochoa-Sánchez, Luz Edith

    2015-01-01

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

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

    PubMed

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

    2016-01-20

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

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

    PubMed

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

    2005-01-01

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

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

    PubMed

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

    2008-01-01

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

  17. 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.

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

    PubMed

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

    2014-04-01

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

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

    PubMed

    Kinoshita, Yuta; Niwa, Hidekazu; Katayama, Yoshinari

    2015-06-01

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

  20. 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.

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

    PubMed

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

    2014-01-01

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

  2. Gram-negative bacteria from the camel tick Hyalomma dromedarii (Ixodidae) and the chicken tick Argas persicus (Argasidae) and their antibiotic sensitivities.

    PubMed

    Montasser, Ashraf A

    2005-04-01

    A total of nine species of gram-negative bacteria were isolated from organs and haemolymph of the hard tick Hyalomma (Hyalomma) dromedarii and the soft tick Argas (Persicargas) persicus. Four species namely Serratia liquefaciens, Stenotrophomonas maltophilia, Klebsiella ornithinolytica and Aeromonas hydrophila were isolated from H. dromedarii and five species namely Rahnella aquatilis, Pseudomonas fluorescens, Enterobacter cloacae, Chryseomonas luteola and Chryseobacterium meningosepticum were isolated from A. persicus. Isolated bacteria were identified using the analytical profile index 20E. Disk diffusion test was carried out on all isolated bacteria to determine antibiotic sensitivity of chloramphenicol, amoxillin/clavulanic acid, neomycin, streptomycin, triplesulphur tetracycline and nitrofurantion. The results were discussed. PMID:15880998

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

    PubMed

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

    2003-09-01

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

  4. 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-?g 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-?g disk. Colistin displayed excellent activity against S. maltophilia and A. xylosoxidans and the disk diffusion assay could be confidently used to determine the susceptibility to colistin for MDR Gram-negative bacteria in the context of CF. PMID:23719852

  5. 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

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

    PubMed

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

    2016-03-20

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2007-01-01

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

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

    PubMed

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

    2014-06-01

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

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

    PubMed

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

    2015-10-01

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

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

    PubMed

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

    2004-12-01

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

  12. Rahnella aquatilis Sepsis in a Premature Newborn

    PubMed Central

    Kuzdan, Canan; Soysal, Ahmet; zdemir, Hlya; Co?kun, ?enay; Akman, ?pek; Bilgen, Hlya; zek, Eren; Bak?r, Mustafa

    2015-01-01

    Rahnella aquatilis is an infrequently isolated Gram-negative rod within the Enterobacteriaceae family. The organism's natural habitat is water. The organism is rarely isolated from clinical specimens and it seldom causes infection in immunocompetent individuals. Here we present a one-month-old boy who was born prematurely at 27th week of gestation by cesarean section with a birth weight of 730?g. He developed sepsis caused by Rahnella aquatilis during the treatment for ventilator associated pneumonia due to Stenotrophomonas maltophilia with ciprofloxacin. He was successfully treated with a combination of amikacin plus meropenem. Although R. aquatilis is one of the saprophyticus organisms, it may cause life-threatening infection in newborn. PMID:26090257

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

    PubMed

    Lee, Yoonjin

    2013-09-01

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

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

    PubMed

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

    2006-12-15

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

  15. 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

  16. Association of qacE and qacEDelta1 with multiple resistance to antibiotics and antiseptics in clinical isolates of Gram-negative bacteria.

    PubMed

    Kcken, D; Feucht, H; Kaulfers, P

    2000-02-01

    Clinical isolates of Enterobacter cloacae, Citrobacter freundii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia were tested for resistance to antibiotics and to the antiseptics benzalkonium chloride and cetyltrimethylammonium bromide. Furthermore, they were examined for the presence of the resistance genes qacE and qacEDelta1. qacEDelta1 was detected by PCR in 10% of all (n=103) and in 81% of multiply antibiotic-resistant strains (n=15). qacE was found in only one of 37 P. aeruginosa strains. The minimum inhibitory concentrations of benzalkonium chloride, cetyltrimethylammonium bromide, and ethidium bromide were not significantly different for qacEDelta1/qacE-positive or -negative strains. Our data indicate that multiply antibiotic-resistant Gram-negative bacteria are not necessarily more resistant to quaternary ammonium compounds than antibiotic-sensitive strains even though qacE or qacEDelta1 is present. PMID:10650208

  17. 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

  18. Antimicrobial activities of the essential oils of Origanum onites L., Origanum vulgare L. subspecies hirtum (Link) Ietswaart, Satureja thymbra L., and Thymus cilicicus Boiss. & Bal. growing wild in Turkey.

    PubMed

    Sarac, Nurdan; Ugur, Aysel

    2008-09-01

    In the present study, four separate samples of Origanum onites L., three separate samples of Satureja thymbra L., Origanum vulgare L. ssp. hirtum (Link) Ietswaart, and Thymus cilicicus Boiss. & Bal. were collected from various regions of Mugla, Turkey. The essential oils of these plants were obtained by the hydrodistillation method. Antimicrobial activities of the essential oils against microorganisms, including multiple antibiotic-resistant bacteria, were investigated using the disc diffusion method. Different antibiotic discs were used for comparison to the inhibition zones. All the essential oils used in this study were very effective against Gram-positive and Gram-negative bacteria, which included multiple resistant strains, except Pseudomonas aeruginosa ATCC 27853 and Pseudomonas fluorescens MU 87. The essential oils of the O. onites, O. vulgare ssp. hirtum, and S. thymbra were especially very effective against the resistant strains such as Stenotrophomonas maltophilia MU 64, S. maltophilia MU 99, and Chryseomonas luteola MU 65. The maximum antimicrobial activity was observed with the essential oils of O. onites. The antimicrobial activities of the essential oils varied depending on the species, subspecies, or variety. In fact, the essential oils of some plants belonging to the same species that were collected from different locations showed different levels of antimicrobial activities. PMID:18800908

  19. 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. PMID:23640079

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

    PubMed

    Andreazza, Robson; Okeke, Benedict C; Lambais, Mrcio Rodrigues; Bortolon, Leandro; de Melo, George Wellington Bastos; Camargo, Flvio Anastcio 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? dry mass was extracted from plants grown in Inceptisol soil. The vineyard Mollisol copper uptake (55 mg Cu kg? of dry mass) in the shoots was significantly improved upon inoculation of oatmeal plants with isolate A2 (128 mg of Cu kg? 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? 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. PMID:20937516

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

    PubMed

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

    2015-02-01

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

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

    PubMed

    Yorioka, Katsuhiro; Oie, Shigeharu; Kamiya, Akira

    2010-03-01

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

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

    PubMed Central

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

    2011-01-01

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

  4. 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

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

    PubMed

    Martnez, Jorge; Segura, Pablo; Garca, David; Aduriz, Gorka; Ibabe, Jos 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. PMID:15996494

  6. 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.

  7. 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.

  8. Bacteria associated with Amblyomma cajennense tick eggs.

    PubMed

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

    2015-12-01

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

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

    PubMed

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

    2015-12-01

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

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

    PubMed

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

    2012-08-01

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

  11. Adhesive properties of predominant bacteria in raw cow's milk to bovine mammary gland epithelial cells.

    PubMed

    Hagi, Tatsuro; Sasaki, Keisuke; Aso, Hisashi; Nomura, Masaru

    2013-11-01

    Various bacteria have been found in raw cow's milk, and identifying milk microflora and its functions is critical for maintaining cow health and farm hygiene. Although studies on pathogens and spoilage bacteria in milk have been widely reported, the relationship between milk bacteria, including nonpathogenic bacteria, and the bovine udder is poorly understood. We investigated milk microflora over 1year using a culture-dependent method and culture-independent analysis by denaturing gradient gel electrophoresis. Among 240 isolates, Lactococcus lactis (81/240) was predominant. The predominant genera were Lactococcus, Stenotrophomonas, Microbacterium, Chryseobacterium, Serratia and Pseudomonas. Among seven strains belonging to these predominant genera, two strains of L. lactis (ssp. lactis and ssp. cremoris) exhibited the highest adherence to bovine mammary gland epithelial cells (BMECs) derived from the bovine udder; 3.4% of the inoculated bacteria adhered to BMECs. This was followed by Serratia sp. (1.6%), Microbacterium sp. (0.8%), Stenotrophomonas maltophilia (0.5%), Pseudomonas sp. (0.3%) and Chryseobacterium sp. (0.1%). The two L. lactis isolates exhibited higher adherence to BMECs than type strains and isolates of various origins. PMID:23532507

  12. Cloning, Expression and Crystallization of Heterotetrameric Sarcosine Oxidase from Pseudomonas maltophilia

    PubMed Central

    Hassan-Abdallah, Alshaimaa; Zhao, Guohua; Eschenbrenner, Michael; Chen, Zhi-wei; Mathews, F. Scott; Jorns, Marilyn Schuman

    2005-01-01

    Heterotetrameric sarcosine oxidase (TSOX) is a complex bifunctional enzyme that catalyzes the oxidation of the methyl group in sarcosine (N-methylglycine) and transfer of the oxidized methyl group into the 1-carbon metabolic pool. In addition to four different subunits, TSOX contains three coenzymes (FAD, FMN, NAD) and a binding site for tetrahydrofolate, the coenzyme acceptor of the oxidized methyl group from sarcosine. Based on preliminary success in crystallization of the natural enzyme, the genes encoding the subunits for TSOX from Pseudomonas maltophila (pTSOX) were cloned by functional screening of a genomic library. Recombinant enzyme exhibiting the same specific activity as natural pTSOX could not be isolated using a similar or identical purification procedure. This difficulty was overcome by affinity purification of recombinant pTSOX containing a C-terminal (His)6 tag on the subunit (?) encoded by soxG, the gene located at the 3? end of the pTSOX operon. Affinity purified pTSOX could not be crystallized, a problem traced to microheterogeneity in the recombinant enzyme where about half of the FMN is present in a modified form that is not found in the natural enzyme and may be a biosynthetic intermediate. The modified flavin was eliminated by expression of the recombinant enzyme in the presence of sarcosine, the same reagent used to induce expression of the natural enzyme. Homogenous recombinant pTSOX was isolated from cells grown in the presence of sarcosine by chromatography on affinity and hydrophobic interaction matrices. High quality crystals that diffract to 1.85 resolution have been obtained. PMID:15922624

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

    PubMed

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

    2015-01-01

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

  14. 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.

  15. 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

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

    PubMed

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

    2015-10-01

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

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

    PubMed

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

    2015-06-25

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

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

    PubMed

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

    2014-12-01

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

  19. 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

  20. 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; Mart, Esther; Sierra, Jordi; Cruaas, Robert; Garau, M Antonia; Triad-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. PMID:22658943

  1. Identification of Pandoraea Species by 16S Ribosomal DNA-Based PCR Assays

    PubMed Central

    Coenye, Tom; Liu, Lixia; Vandamme, Peter; LiPuma, John J.

    2001-01-01

    The recently described genus Pandoraea contains five named species (Pandoraea apista, Pandoraea pulmonicola, Pandoraea pnomenusa, Pandoraea sputorum, and Pandoraea norimbergensis) and four unnamed genomospecies. Pandoraea spp. have mainly been recovered from the respiratory tracts of cystic fibrosis (CF) patients. Accurate genus- and species-level identification by routine clinical microbiology methods is difficult, and differentiation from Burkholderia cepacia complex organisms may be especially problematic. This can have important consequences for the management of CF patients. On the basis of 16S ribosomal DNA sequences, PCR assays for the identification of Pandoraea spp. were developed. A first PCR assay was developed for the identification of Pandoraea isolates to the genus level. PCR assays for the identification of P. apista and P. pulmonicola as a group, P. pnomenusa, P. sputorum, and P. norimbergensis were also developed. All five assays were evaluated with a panel of 123 bacterial isolates that included 69 Pandoraea sp. strains, 24 B. cepacia complex strains, 6 Burkholderia gladioli strains, 9 Ralstonia sp. strains, 5 Alcaligenes xylosoxidans strains, 5 Stenotrophomonas maltophilia strains, and 5 Pseudomonas aeruginosa strains. The use of these PCR assays facilitates the identification of Pandoraea spp. and avoids the misidentification of a Pandoraea sp. as a B. cepacia complex isolate. PMID:11724860

  2. Identification of Pandoraea species by 16S ribosomal DNA-based PCR assays.

    PubMed

    Coenye, T; Liu, L; Vandamme, P; LiPuma, J J

    2001-12-01

    The recently described genus Pandoraea contains five named species (Pandoraea apista, Pandoraea pulmonicola, Pandoraea pnomenusa, Pandoraea sputorum, and Pandoraea norimbergensis) and four unnamed genomospecies. Pandoraea spp. have mainly been recovered from the respiratory tracts of cystic fibrosis (CF) patients. Accurate genus- and species-level identification by routine clinical microbiology methods is difficult, and differentiation from Burkholderia cepacia complex organisms may be especially problematic. This can have important consequences for the management of CF patients. On the basis of 16S ribosomal DNA sequences, PCR assays for the identification of Pandoraea spp. were developed. A first PCR assay was developed for the identification of Pandoraea isolates to the genus level. PCR assays for the identification of P. apista and P. pulmonicola as a group, P. pnomenusa, P. sputorum, and P. norimbergensis were also developed. All five assays were evaluated with a panel of 123 bacterial isolates that included 69 Pandoraea sp. strains, 24 B. cepacia complex strains, 6 Burkholderia gladioli strains, 9 Ralstonia sp. strains, 5 Alcaligenes xylosoxidans strains, 5 Stenotrophomonas maltophilia strains, and 5 Pseudomonas aeruginosa strains. The use of these PCR assays facilitates the identification of Pandoraea spp. and avoids the misidentification of a Pandoraea sp. as a B. cepacia complex isolate. PMID:11724860

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

    PubMed Central

    de Arajo Barros, Irene; Luiz Arajo, Welington; Lcio Azevedo, Joo

    2010-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  5. 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. PMID:24151598

  6. ISCR Elements: Novel Gene-Capturing Systems of the 21st Century?

    PubMed Central

    Toleman, Mark A.; Bennett, Peter M.; Walsh, Timothy R.

    2006-01-01

    Common regions (CRs), such as Orf513, are being increasingly linked to mega-antibiotic-resistant regions. While their overall nucleotide sequences show little identity to other mobile elements, amino acid alignments indicate that they possess the key motifs of IS91-like elements, which have been linked to the mobility ent plasmids in pathogenic Escherichia coli. Further inspection reveals that they possess an IS91-like origin of replication and termination sites (terIS), and therefore CRs probably transpose via a rolling-circle replication mechanism. Accordingly, in this review we have renamed CRs as ISCRs to give a more accurate reflection of their functional properties. The genetic context surrounding ISCRs indicates that they can procure 5? sequences via misreading of the cognate terIS, i.e., unchecked transposition. Clinically, the most worrying aspect of ISCRs is that they are increasingly being linked with more potent examples of resistance, i.e., metallo-?-lactamases in Pseudomonas aeruginosa and co-trimoxazole resistance in Stenotrophomonas maltophilia. Furthermore, if ISCR elements do move via unchecked RC transposition, as has been speculated for ISCR1, then this mechanism provides antibiotic resistance genes with a highly mobile genetic vehicle that could greatly exceed the effects of previously reported mobile genetic mechanisms. It has been hypothesized that bacteria will surprise us by extending their genetic construction kit to procure and evince additional DNA and, therefore, antibiotic resistance genes. It appears that ISCR elements have now firmly established themselves within that regimen. PMID:16760305

  7. Characterizing Novel Thermophilic Amylase Producing Bacteria From Taptapani Hot Spring, Odisha, India

    PubMed Central

    Sen, Sudip Kumar; Raut, Sangeeta; Satpathy, Soumya; Rout, Prangya Ranjan; Bandyopadhyay, Bidyut; Das Mohapatra, Pradeep Kumar

    2014-01-01

    Background: Amylases play a vital role in biotechnological studies and rank an important position in the world enzyme market (25% to 33%). Bioprocess method of amylase production is more effective than the other sources, since the technique is easy, cost effective, fast, and the enzymes of required properties can be procured. Objectives: The current study aimed to report the characteristics of novel amylase producing bacterial strains isolated from Taptapani hot spring, Odisha, India. Materials and Methods: Bacterial strains were isolated by dilution plating method from the water samples collected from Taptapani Hot Spring, Odisha and screened for amylase production through starch hydrolysis. The bacterial isolates were identified morphologically, biochemically, and finally by 16S rDNA profiling. Results: Based on the morphological, physiological, biochemical characteristics and the molecular characterization, the isolates SS1, SS2, and SS3 were identified as Bacillus barbaricus, Aeromonas veroni, and Stenotrophomonas maltophilia, respectively. The approximate molecular weight of enzymes from SS1, SS2, and SS3 strains were 19 kDa, 56 kDa and 49 kDa, respectively. Conclusions: The current report isolates, characterizes, and demonstrates the novel heat-adapted amylase-producing bacteria SS1, SS2 and SS3 from Taptapani hot spring, indicating its potentiality and stability under acidic conditions. PMID:25741425

  8. Prevalence of antibiotic-resistant bacteria in herbal products.

    PubMed

    Brown, Joseph C; Jiang, Xiuping

    2008-07-01

    The objective of this study was to determine the prevalence of antibiotic-resistant bacteria in various herbal products. Twenty-nine herbal supplements (18 traditional and 11 organic products) were purchased from stores and analyzed microbiologically. Total bacterial counts were determined by pour plate and surface spreading on tryptic soy agar (TSA). Antibiotic-resistant bacteria were enumerated on TSA supplemented with ceftriaxone (64 microg/ml) or tetracycline (16 microg/ml). Total bacterial counts ranged from <5 to 2.9 x 10(5) CFU/g. Ceftriaxone- and tetracycline-resistant bacteria were detected in ground garlic samples at 1.1 x 10(2) CFU/g and 3.0 x 102 CFU/g, respectively. Traditional and organic onion powder samples contained tetracycline-resistant bacteria at 17 and 28 CFU/g and ceftriaxone-resistant bacteria at 35 and 2.0 x 10(3) CFU/g, respectively. Other products such as ginger, rosemary, mustard, and goldenseal contained low levels of resistant bacteria. Fifty-two isolates were further evaluated against nine antibiotics, and the prevalence of antibiotic resistance was in the following order: ampicillin, nalidixic acid, trimethoprim, ceftriaxone, and streptomycin. Resistant bacteria were identified as Bacillus spp., Erwinia spp., and Ewingella americana. Staphylococcus spp., Enterobacter cloacae, and Stenotrophomonas maltophilia also were isolated. The presence of antibiotic-resistant bacteria and pathogens in these herbal products suggests that production and use of these products may need further evaluation. PMID:18680952

  9. Rosmarinic Acid from Eelgrass Shows Nematicidal and Antibacterial Activities against Pine Wood Nematode and Its Carrying Bacteria

    PubMed Central

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

    2012-01-01

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

  10. 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 4h for the disinfectant test strains and within 6h for producing Acinetobacter baumannii, Klebsiella pneumoniae and Stenotrophomonas maltophilia. Activity against the other hospital isolates was slower but still gave log10 reduction factors of >5 for extended spectrum ?-lactamase producing Escherichia coli and >3 for vancomycin resistant Enterococcus faecium, methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa within 24h. 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

  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 10100-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. 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

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

    PubMed

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

    2005-11-01

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

  14. 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 ?M) 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

  15. 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

  16. High-rate biological denitrification in the cyclic rotating-bed biological reactor: Effect of COD/NO3(-), nitrate concentration and salinity and the phylogenetic analysis of denitrifiers.

    PubMed

    Jafari, Seyed Javad; Moussavi, Gholamreza; Yaghmaeian, Kamyar

    2015-12-01

    The effects of COD/NO3(-) ratio, nitrate concentration and salinity was tested on the performance of the CRBR in denitrification with catechol as carbon source. The maximum nitrate reduction attained at COD/NO3(-) ratio of 1. The CRBR operated at optimum COD/NO3(-) ratio could completely denitrify the nitrate at inlet concentration up to 1250mg/L without nitrite accumulation. The maximum denitrification rate in the CRBR was 3.56kgNO3(-)/m(3)d with a nitrate reduction efficiency of 99% when the bioreactor was operated at inlet nitrate loading rate of 3.6kgNO3(-)/m(3)d. The denitrification performance of the CRBR was not affected significantly by NaCl concentrations up to 20g/L. 16S rRNA fragment and phylogenetic analysis identified Pseudomonas resinovorans, Stenotrophomonas maltophilia and Bacillus cereus as the most abundant denitrifiers in biomass. Accordingly, the CRBR is a high-rate bioreactor and appropriate technology for treatment of nitrate-laden industrial wastewaters containing phenolic compounds and salinity. PMID:26369277

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

    PubMed

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

    2015-12-01

    Whole-cell biotransformation of fatty acids can be influenced by the activities of catalytic enzymes and by the efficiency of substrate transport into host cells. Here, we improved fatty acid hydration activity of the recombinant Escherichia coli expressing an oleate hydratase of Stenotrophomonas maltophilia by targeting the catalytic enzyme into the periplasm instead of the cytoplasm. Recombinant E. coli producing OhyA in the periplasm under guidance of the PelB signal sequence (E. coli OhyA_PP) exhibited significantly greater hydration activity with oleic acid and linoleic acid compared to a recombinant E. coli producing OhyA in the cytoplasm (E. coli OhyA_CS). For example, the oleate double bond hydration rate of E. coli OhyA_PP was >400 μmol/g dry cells/min (400 U/g dry cells), which is >10-fold higher than that of E. coli OhyA_CS. As the specific activities of the enzymes targeted into the cytoplasm and periplasm were comparable, we assumed that targeting OhyA into the periplasm could accelerate fatty acid transport to the catalytic enzymes by skipping the major mass transport barrier of the cytoplasmic membrane. Our results will contribute to the development of whole-cell biocatalysts for fatty acid biotransformation. PMID:26429801

  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: 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

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

    PubMed

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

    2016-01-01

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

  20. Bacterial bioeffectors modify bioactive profile and increase isoflavone content in soybean sprouts (Glycine max var Osumi).

    PubMed

    Algar, Elena; Ramos-Solano, Beatriz; García-Villaraco, Ana; Sierra, M Dolores Saco; Gómez, M Soledad Martín; Gutiérrez-Mañero, F Javier

    2013-09-01

    The effect of two bacterial strains to enhance bioactive contents (total phenolic compounds, total flavonoid compounds and isoflavones) and antioxidant activity on 3-day-old soybean sprouts were investigated. To identify bacterial determinants responsible for these effects, viable and UV-treated strains were delivered to wounded seeds at different concentration. Multivariate analysis performed with all the evaluated parameters indicated the different effectiveness of Stenotrophomonas maltophilia N5.18 and Pseudomonas fluorescens N21.4 based on different structural and metabolic determinants for each. N21.4 increased total phenolics and isoflavones from the genistein family, while N5.18 triggered biosynthesis of daidzein and genistein families coupled to a decrease in total phenolics, suggesting different molecular targets in the phenilpropanoid pathway. Only extracts from N5.18 treated seeds showed an improved antioxidant activity according to the β-carotene bleaching prevention method. In summary, bioeffectors from both bacterial strains are effective tools to improve soybean sprouts quality; structural elicitors from N5.18 also enhanced antioxidant activity, being the best alternative for further development of a biotechnological procedure. PMID:23918406

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

    PubMed

    Cardoso, Jusclio 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

  2. 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

  3. 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

  4. The Disinfecting Potential of Contact Lens Soutions used by Sultan Qaboos University Students

    PubMed Central

    Nzeako, B. C.; Al-Sumri, Sara H.

    2011-01-01

    Objectives: This study aimed to determine the disinfecting potential of some contact lens solutions used by some university students in Oman. Methods: This work was carried out from January to June 2010 in the Department of Microbiology & Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Oman. Fifty disinfecting solutions, in which contact lenses were disinfected according to the manufacturers’ instructions, were collected from the students and plated on various microbiological culture media. Bacterial isolates were identified by API-20E, API-20NE and Phoenix automated systems while fungi were identified by their cultural characteristics and biochemistry. Results: From 98 isolates, Pseudomonas aeruginosa was 23.5%; Penicillium, 13%; Candida species, 9.2%; coagulase negative staphylococci, 9.2%; Serratia marcescens, 6.1%; Bacillus, 5.1%; Aspergillus flavus, 5.1%; Serratia liquefaciens, Pseudomonas fluorescens, Enterobacter cloacae and Aspergillus niger, 4.1% each; Chryseomonas luteola and Chryseomonas indologenes, 3.1% each; Stenotrophomonas maltophilia, Serratia odorifera, 2.0% each; Enterobacter aerogenes and Klebsiella pneumoniae, 1% each. Most isolates (65%) came from polyhexanide containing solutions. Conclusion: Contact lens disinfecting solutions with the same formulations, but manufactured by different companies, possessed different disinfecting potentials. PMID:21969898

  5. Bacteria from Ips sexdentatus (Coleoptera: Curculionidae) and their biocontrol potential.

    PubMed

    Sevim, Ali; Gke, Cihan; Erba?, Zeynep; Ozkan, Filiz

    2012-12-01

    Ips sexdentatus (Coleoptera: Curculionidae) is one of the most destructive pests of the spruce trees in Europe. In this study, we have isolated and characterized culturable bacteria from I. sexdentatus and tested their insecticidal activity against the last instar larvae of the pest as a possible biocontrol agent. A total of eight bacterial isolates was determined and four of them were identified at species level, and the others were identified at genus level. Isolates were identified as Stenotrophomonas maltophilia (Is1), Rahnella sp. (Is2), Pseudomonas sp. (Is3), Bacillus sp. (Is4), Alcaligenes faecalis (Is5), Panteoea agglomerans (Is6), Pseudomonas fluorescens (Is7) and Serratia sp. (Is8) based on their morphological, biochemical and molecular characteristics. Insecticidal effects of bacterial isolates were performed on the last instar larvae of the pest. The highest insecticidal activity was obtained from P. fluorescens (Is7) with 73% mortality within 10 days after inoculation (p < 0.05). Mortality values of the other isolates ranged from 20 to 53%. This study suggests that Pseudomonas fluorescens (Is7) seems to be a good candidate as a possible biocontrol agent against I. sexdentatus, and provides suitable strains that can be modified to express insecticidal toxins and/or other detrimental substances to develop new control methods for I. sexdentatus. PMID:22581609

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

    PubMed Central

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

    2011-01-01

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

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

    PubMed Central

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

    2008-01-01

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

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

    PubMed

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

    2006-09-01

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

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

    PubMed

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

    2010-10-01

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

  10. 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

  11. Characterization of contaminants from a sanitized milk processing plant.

    PubMed

    Cleto, Sara; Matos, Snia; Kluskens, Leon; Vieira, Maria Joo

    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

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

    PubMed

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

    2014-11-01

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

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

    PubMed

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

    2011-09-01

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

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

    PubMed

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

    2012-12-01

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

  15. 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

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

    PubMed Central

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

    2015-01-01

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

  17. Reducing the development of antibiotic resistance in critical care units.

    PubMed

    Deege, Marjolein P D; Paterson, David L

    2011-12-01

    Bacteria becoming resistant to an increasing number of antibiotic classes are a major problem at hospitals including critical care units worldwide. Awareness of this problem and the need to prevent the development of antibiotic resistance are very important, especially since very few new antibiotics will become available in the near future. This article gives an overview of the mechanisms of antibacterial resistance and actual resistance data worldwide of the most prevalent Gram positive (MRSA, VISA/VRSE and VRE) and Gram negative bacteria (Pseudomonas aeruginosa, Acinetobacter spp., ESBL producing Enterobacteriaceae and Stenotrophomonas maltophilia). Furthermore, strategies to reduce antibiotic resistance are reviewed. Most important is institution of infection control policies including guidelines on surveillance, isolation of colonized patients and contact precautions, hand hygiene, decolonization measures and environmental decontamination. Antimicrobial stewardship, or striking the balance between an optimal antibiotic treatment for a patient and a minimal risk of development of antibiotic resistance, is another important strategy. Finally, optimizing of antibiotic dosage regimens and thus avoiding underdosage is essential to avoid selection of the most resistant subpopulation of bacteria during antibiotic treatment. Intensive care units with knowledge of local epidemiology of resistance, an effective infection control program and antimicrobial stewardship policy tailored to their specific needs, and using optimal antibiotic dosing regimens have both locally decreased the risk of an outbreak with multi-resistant bacteria, and maybe even more important help to reduce the development of antibiotic resistance. PMID:22188438

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

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  19. Bacterial contamination of water in dental unit reservoirs.

    PubMed

    Szyma?ska, Jolanta

    2007-01-01

    The aim of this study was bacteriological assessment of water in dental unit reservoirs--concentration and composition of the aerobe and facultative anaerobe bacterial microflora. Reservoir water samples were taken from 25 units. Bacterial flora were determined with the plate culture method. Bacteria were identified with biochemical microtests: API 20E, API 20NE (bioMrieux, France) and GP2 MicroPlateTM (BIOLOG, USA). The concentration of total bacteria isolated from one site was 201,039 cfu/ml, on average; the minimum was 22,300 cfu/ml, and the maximum - 583,000 cfu/ml. The following bacteria were identified: Gram-negative bacteria--Brevundimonas vesicularis, Moraxella lacunata, Moraxella spp., Ralstonia pickettii, Sphingomonas paucimobilis, Stenotrophomonas maltophilia; Gram-positive cocci--Micrococcus luteus, Micrococcus lylae, Staphylococcus cohnii, Staphylococcus hominis ss novobiosepticus, Staphylococcus spp., Streptococcus spp.; actinomycetes--Streptomyces albus. The prevailing bacteria were: Ralstonia pickettii (96.46%), found in all the units. Sphingomonas paucimobilis (1.32%) and Brevundimonas vesicularis (1.07%) were the next most frequently occurring bacteria. Bacteria concentration in dental unit reservoirs reached excessive values, and the bacterial flora were composed of the bacteria characteristic for water supply systems, opportunistic pathogens, and bacteria of the oral cavity flora. Continuous microbiological monitoring of the DUWL water, including application of a disinfecting procedure, is necessary. PMID:17655191

  20. Contemporary unconventional clinical use of co-trimoxazole.

    PubMed

    Goldberg, E; Bishara, J

    2012-01-01

    In the late 1960s, the combination of trimethoprim and sulphamethoxazole (co-trimoxazole) was introduced into clinical practice and used to treat many infectious diseases, such as urinary tract infections, respiratory infections, sexually transmitted diseases, Gram-negative sepsis, enteric infections and typhoid fever. Subsequently, co-trimoxazole was reported to be effective against numerous bacterial, fungal and protozoal pathogens, including Nocardia, Listeria monocytogenes, Brucella, Stenotrophomonas maltophilia, Burkholderia, Coxiella burnetii, Tropheryma whipplei, atypical mycobacteria, and Pneumocystis jirovecii. Among protozoal infections, in addition to toxoplasmosis, co-trimoxazole has been used to treat susceptible Plasmodium falciparum, Cyclospora and Isospora infections. Several retrospective and prospective studies have demonstrated good clinical outcome with co-trimoxazole in treating invasive methicillin-resistant Staphylococcus aureus infections. We summarize herein the accumulated evidence in the literature on the new, 'unconventional' clinical use of co-trimoxazole during the last three decades. In the era of widespread antibiotic resistance and shortage of new antibiotic options, large-scale, well-designed studies are needed to explore the tremendous potential concealed in this well-established drug. PMID:21851485

  1. 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

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

    PubMed

    Scholtz, V; Julk, J; Krha, V; Mosinger, J; Kopeck, 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

  3. Occurrence of gram-negative bacteria in drinking water undergoing softening treatment.

    PubMed

    Romano, G; Stampi, S; Zanetti, F; De Luca, G; Tonelli, E

    1997-08-01

    A study was carried out on the presence of Gram-negative bacteria in the municipal waters of Bologna (Italy) undergoing softening using domestic ion exchangers with an automatic disinfection mechanism. The softening process was seen to cause a 15 fold increase in 22 degrees C and 36 degrees C heterotrophic plate counts. There was a 30 fold increase in Gram-negative bacteria and their number correlated directly with temperature and inversely with active residual chlorine. Organic matter had no effect on bacterial growth. The most commonly found bacteria were various species of Pseudomonas (87.6%) (Ps. acidovorans, Ps. denitrificans, Ps. fluorescens and Ps. testosteroni) followed by Aeromonas hydrophila (5.6%) and Stenotrophomonas (Xantomonas) maltophilia (3.8% in outgoing water). Pseudomonas aeruginosa (present in 5.6% of incoming water samples and 0.4% of outgoing water) and Yersinia enterocolitica (present in 4.3% of incoming water samples and 1.1% of outgoing water) did not find favorable conditions for growth on the ion exchange resins. PMID:9636986

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

    PubMed

    2016-03-01

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

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

    PubMed

    Mirand, Claudio D; Zemelman, Raul

    2002-07-01

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

  6. Specific and Functional Diversity of Endophytic Bacteria from Pine Wood Nematode Bursaphelenchus Xylophilus with Different Virulence

    PubMed Central

    Wu, Xiao-Qin; Yuan, Wei-Min; Tian, Xiao-Jing; Fan, Ben; Fang, Xin; Ye, Jian-Ren; Ding, Xiao-Lei

    2013-01-01

    Pine wilt disease (PWD) caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus, is one of the most devastating diseases of Pinus spp. The PWN was therefore listed as one of the most dangerous forest pests in China meriting quarantine. Virulence of the PWN is closely linked with the spread of PWD. However, main factors responsible for the virulence of PWNs are still unclear. Recently epiphytic bacteria carried by PWNs have drawn much attention. But little is known about the relationship between endophytic bacteria and virulence of B. xylophilus. In this research, virulence of ten strains of B. xylophilus from different geographical areas in six provinces of China and four pine species were tested with 2-year-old seedlings of Pinus thunbergii. Endophytic bacteria were isolated from PWNs with different virulence to investigate the relationship between the bacteria and PWN virulence. Meanwhile, the carbon metabolism of endophytic bacteria from highly and low virulent B. xylophilus was analyzed using Biolog plates (ECO). The results indicated that ten strains of PWNs showed a wide range of virulence. Simultaneously, endophytic bacteria were isolated from 90% of the B. xylophilus strains. The dominant endophytic bacteria in the nematodes were identified as species of Stenotrophomonas, Achromobacter, Ewingella, Leifsonia, Rhizobium, and Pseudomonas using molecular and biochemical methods. Moreover, S. maltophilia, and A. xylosoxidans subsp. xylosoxidans were the predominant strains. Most of the strains (80%) from P. massoniana contained either S. maltophilia, A. xylosoxidans, or both species. There was a difference between the abilities of the endophytic bacteria to utilize carbon sources. Endophytic bacteria from highly virulent B. xylophilus had a relatively high utilization rate of carbohydrate and carboxylic acids, while bacteria from low virulent B. xylophilus made better use of amino acids. In conclusion, endophytic bacteria widely exist in B. xylophilus from different pines and areas; and B. xylophilus strains with different virulence possessed various endophytic bacteria and diverse carbon metabolism which suggested that the endophytic bacteria species and carbon metabolism might be related with the B. xylophilus virulence. PMID:23289015

  7. Specific and functional diversity of endophytic bacteria from pine wood nematode Bursaphelenchus xylophilus with different virulence.

    PubMed

    Wu, Xiao-Qin; Yuan, Wei-Min; Tian, Xiao-Jing; Fan, Ben; Fang, Xin; Ye, Jian-Ren; Ding, Xiao-Lei

    2013-01-01

    Pine wilt disease (PWD) caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus, is one of the most devastating diseases of Pinus spp. The PWN was therefore listed as one of the most dangerous forest pests in China meriting quarantine. Virulence of the PWN is closely linked with the spread of PWD. However, main factors responsible for the virulence of PWNs are still unclear. Recently epiphytic bacteria carried by PWNs have drawn much attention. But little is known about the relationship between endophytic bacteria and virulence of B. xylophilus. In this research, virulence of ten strains of B. xylophilus from different geographical areas in six provinces of China and four pine species were tested with 2-year-old seedlings of Pinus thunbergii. Endophytic bacteria were isolated from PWNs with different virulence to investigate the relationship between the bacteria and PWN virulence. Meanwhile, the carbon metabolism of endophytic bacteria from highly and low virulent B. xylophilus was analyzed using Biolog plates (ECO). The results indicated that ten strains of PWNs showed a wide range of virulence. Simultaneously, endophytic bacteria were isolated from 90% of the B. xylophilus strains. The dominant endophytic bacteria in the nematodes were identified as species of Stenotrophomonas, Achromobacter, Ewingella, Leifsonia, Rhizobium, and Pseudomonas using molecular and biochemical methods. Moreover, S. maltophilia, and A. xylosoxidans subsp. xylosoxidans were the predominant strains. Most of the strains (80%) from P. massoniana contained either S. maltophilia, A. xylosoxidans, or both species. There was a difference between the abilities of the endophytic bacteria to utilize carbon sources. Endophytic bacteria from highly virulent B. xylophilus had a relatively high utilization rate of carbohydrate and carboxylic acids, while bacteria from low virulent B. xylophilus made better use of amino acids. In conclusion, endophytic bacteria widely exist in B. xylophilus from different pines and areas; and B. xylophilus strains with different virulence possessed various endophytic bacteria and diverse carbon metabolism which suggested that the endophytic bacteria species and carbon metabolism might be related with the B. xylophilus virulence. PMID:23289015

  8. A novel salt-tolerant chitobiosidase discovered by genetic screening of a metagenomic library derived from chitin-amended agricultural soil.

    PubMed

    Cretoiu, Mariana Silvia; Berini, Francesca; Kielak, Anna Maria; Marinelli, Flavia; van Elsas, Jan Dirk

    2015-10-01

    Here, we report on the construction of a metagenomic library from a chitin-amended disease-suppressive agricultural soil and its screening for genes that encode novel chitinolytic enzymes. The library, constructed in fosmids in an Escherichia coli host, comprised 145,000 clones containing inserts of sizes of 21 to 40 kb, yielding a total of approximately 5.8 GB of cloned soil DNA. Using genetic screenings by repeated PCR cycles aimed to detect gene sequences of the bacterial chitinase A-class (hereby named chi A genes), we identified and characterized five fosmids carrying candidate genes for chitinolytic enzymes. The analysis thus allowed access to the genomic (fosmid-borne) context of these genes. Using the chiA-targeted PCR, which is based on degenerate primers, the five fosmids all produced amplicons, of which the sequences were related to predicted chitinolytic enzyme-encoding genes of four different host organisms, including Stenotrophomonas maltophilia. Sequencing and de novo annotation of the fosmid inserts confirmed that each one of these carried one or more open reading frames that were predicted to encode enzymes active on chitin, including one for a chitin deacetylase. Moreover, the genetic contexts in which the putative chitinolytic enzyme-encoding genes were located were unique per fosmid. Specifically, inserts from organisms related to Burkholderia sp., Acidobacterium sp., Aeromonas veronii, and the chloroflexi Nitrolancetus hollandicus and/or Ktedonobacter racemifer were obtained. Remarkably, the S. maltophilia chiA-like gene was found to occur in two different genetic contexts (related to N. hollandicus/K. racemifer), indicating the historical occurrence of genetic reshufflings in this part of the soil microbiota. One fosmid containing the insert composed of DNA from the N. hollandicus-like organism (denoted 53D1) was selected for further work. Using subcloning procedures, its putative gene for a chitinolytic enzyme was successfully brought to expression in an E. coli host. On the basis of purified protein preparations, the produced protein was characterized as a chitobiosidase of 43.6 kDa, with a pI of 4.83. Given its activity spectrum, it can be typified as a halotolerant chitobiosidase. PMID:26040993

  9. 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

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

    PubMed Central

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

    2016-01-01

    Introduction Cystic fibrosis (CF) airways are colonized by a polymicrobial community of organisms, termed the CF microbiota. We sought to define the microbial constituents of the home environment of individuals with CF and determine if it may serve as a latent reservoir for infection. Methods Six patients with newly identified CF pathogens were included. An investigator collected repeat sputum and multiple environmental samples from their homes. Bacteria were cultured under both aerobic and anaerobic conditions. Morphologically distinct colonies were selected, purified and identified to the genus and species level through 16S rRNA gene sequencing. When concordant organisms were identified in sputum and environment, pulsed-field gel electrophoresis (PFGE) was performed to determine relatedness. Culture-independent bacterial profiling of each sample was carried out by Illumina sequencing of the V3 region of the 16s RNA gene. Results New respiratory pathogens prompting investigation included: Mycobacterium abscessus(2), Stenotrophomonas maltophilia(3), Pseudomonas aeruginosa(3), Pseudomonas fluorescens(1), Nocardia spp.(1), and Achromobacter xylosoxidans(1). A median 25 organisms/patient were cultured from sputum. A median 125 organisms/home were cultured from environmental sites. Several organisms commonly found in the CF lung microbiome were identified within the home environments of these patients. Concordant species included members of the following genera: Brevibacterium(1), Microbacterium(1), Staphylococcus(3), Stenotrophomonas(2), Streptococcus(2), Sphingomonas(1), and Pseudomonas(4). PFGE confirmed related strains (one episode each of Sphinogomonas and P. aeruginosa) from the environment and airways were identified in two patients. Culture-independent assessment confirmed that many organisms were not identified using culture-dependent techniques. Conclusions Members of the CF microbiota can be found as constituents of the home environment in individuals with CF. While the majority of isolates from the home environment were not genetically related to those isolated from the lower airways of individuals with CF suggesting alternate sources of infection were more common, a few genetically related isolates were indeed identified. As such, the home environment may rarely serve as either the source of infection or a persistent reservoir for re-infection after clearance. PMID:26859493

  11. Microbial contamination of glaucoma eyedrops used by patients compared with ocular medications used in the hospital.

    PubMed

    Teuchner, Barbara; Wagner, Julia; Bechrakis, Nikolaos E; Orth-Hller, Dorothea; Nagl, Markus

    2015-02-01

    The aim of this study was to compare the percentage of contamination of multiuse eyedrops applied by glaucoma patients at home and by the medical personnel at the outpatient department, the ward, and the operating room of our Department of Ophthalmology. Eyedrops were collected over a period of 11 months. Samples were taken from the dropper tip (smear), drops, and the residual fluid inside the bottle and cultivated on blood agar. Colony forming units were counted and identified by mass spectrometry. The percentage of contamination was significantly higher in eyedrops applied by the patients (29/119; 24.4%, P?Stenotrophomonas maltophilia, and Staphylococcus aureus) were found only in 6 bottles (1.5%), whereas most of the detected microbes belonged to human or environmental flora. This study underlines the importance of hygienic handling of eyedrops and raises the question of whether single-use glaucoma medication might be preferred to reduce the risk of contamination. PMID:25715262

  12. MALDI-TOF: a useful tool for laboratory identification of uncommon glucose non-fermenting Gram-negative bacteria associated with cystic fibrosis.

    PubMed

    Homem de Mello de Souza, Helena Aguilar Peres; Dalla-Costa, Libera Maria; Vicenzi, Fernando Jos; Camargo de Souza, Dilair; Riedi, Carlos Antnio; Filho, Nelson Augusto Rosario; Pilonetto, Marcelo

    2014-09-01

    The predisposition of patients with cystic fibrosis (CF) for recurrent pulmonary infections can result in poor prognosis of the disease. Although the clinical significance in CF of micro-organisms, such as Staphylococcus aureus, Haemophilus influenzae and Pseudomonas aeruginosa, is well established, the implication of uncommon glucose non-fermenting Gram-negative bacilli (UGNF-GNB) in respiratory samples from CF patients is still unclear. Because of limitations of traditional methods used in most clinical laboratories, the accurate identification of these microbes is a challenge. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) is an alternative tool for efficient identification of bacteria. This was a retrospective study to evaluate different identification methods in a collection of UGNF-GNB isolated from children with CF during a period of three years. The performance of MALDI-TOF was compared to that of 16S rDNA gene sequencing and to a conventional and automated phenotypic identification. The discriminatory power of MALDI-TOF (75.0?% agreement) was superior to automated techniques (67.1?% agreement) and to conventional phenotypical identification (50.0?% agreement). MALDI-TOF also demonstrated high accuracy in identifying Stenotrophomonas maltophilia, Achromobacter xylosoxidans and Chryseobacterium indologenes, but had limited utility in identifying Pandoraea spp. and some species of Acinetobacter and Chryseobacterium (other than C. indologenes). Although MALDI-TOF identified only 75?% of the isolates in comparison with 16S rDNA gene sequencing, the prompt identification and high discriminatory power exhibited by MALDI-TOF make it a useful tool for the characterization of micro-organisms that are difficult to identify using routine methods. PMID:24980571

  13. Discrepancy in MALDI-TOF MS identification of uncommon Gram-negative bacteria from lower respiratory secretions in patients with cystic fibrosis

    PubMed Central

    AbdulWahab, Atqah; Taj-Aldeen, Saad J; Ibrahim, Emad Bashir; Talaq, Eman; Abu-Madi, Marawan; Fotedar, Rashmi

    2015-01-01

    Introduction Early identification of microbial organisms from respiratory secretions of patients with cystic fibrosis (CF) is important to guide therapeutic decisions. The objective was to compare the accuracy of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) relative to the conventional phenotypic method in identifying common bacterial isolates, including nonfermenting Gram-negative bacteria, in a cohort of patients with CF. Methods A total of 123 isolates from 50 patients with CF representing 14 bacterial species from respiratory specimens were identified using MALDI-TOF MS in parallel with conventional phenotypic methods. Discrepancies were confirmed by 16S ribosomal RNA (rRNA) gene sequencing in five Gram-negative isolates. Results The MALDI-TOF MS managed to identify 122/123 (99.2%) bacterial isolates to the genus level and 118/123 (95.9%) were identified to the species level. The MALDI-TOF MS results were 100% consistent to the species level with conventional phenotypic identification for isolates of Staphylococcus aureus, Pseudomonas aeruginosa, Haemophilus influenzae, Streptococcus pyogenes, Achromobacter xylosoxidans, Stenotrophomonas maltophilia, and other uncommon organisms such as Chryseobacterium gleum and Enterobacter cloacae. The 5/123 (4.6%) isolates misidentified were all Gram-negative bacteria. The isolation of E. cloacae and Haemophilus paraphrohaemolyticus may extend the potentially pathogenic list of organisms isolated from patients with CF. Conclusion Although the technique provides an early identification and antimicrobial therapy approach in patients with CF, limitation in the diagnosis of uncommon Gram-negative bacteria may exist. PMID:25995646

  14. Evaluation of Microorganisms Cultured from Injured and Repressed Tissue Regeneration Sites in Endangered Giant Aquatic Ozark Hellbender Salamanders

    PubMed Central

    Nickerson, Cheryl A.; Ott, C. Mark; Castro, Sarah L.; Garcia, Veronica M.; Molina, Thomas C.; Briggler, Jeffrey T.; Pitt, Amber L.; Tavano, Joseph J.; Byram, J. Kelly; Barrila, Jennifer; Nickerson, Max A.

    2011-01-01

    Investigation into the causes underlying the rapid, global amphibian decline provides critical insight into the effects of changing ecosystems. Hypothesized and confirmed links between amphibian declines, disease, and environmental changes are increasingly represented in published literature. However, there are few long-term amphibian studies that include data on population size, abnormality/injury rates, disease, and habitat variables to adequately assess changes through time. We cultured and identified microorganisms isolated from abnormal/injured and repressed tissue regeneration sites of the endangered Ozark Hellbender, Cryptobranchus alleganiensis bishopi, to discover potential causative agents responsible for their significant decline in health and population. This organism and our study site were chosen because the population and habitat of C. a. bishopi have been intensively studied from 1969–2009, and the abnormality/injury rate and apparent lack of regeneration were established. Although many bacterial and fungal isolates recovered were common environmental organisms, several opportunistic pathogens were identified in association with only the injured tissues of C.a. bishopi. Bacterial isolates included Aeromonas hydrophila, a known amphibian pathogen, Granulicetella adiacens, Gordonai terrae, Stenotrophomonas maltophilia, Aerococcus viridans, Streptococcus pneumoniae and a variety of Pseudomonads, including Pseudomonas aeruginosa, P. stutzeri, and P. alcaligenes. Fungal isolates included species in the genera Penicillium, Acremonium, Cladosporium, Curvularia, Fusarium, Streptomycetes, and the Class Hyphomycetes. Many of the opportunistic pathogens identified are known to form biofilms. Lack of isolation of the same organism from all wounds suggests that the etiological agent responsible for the damage to C. a. bishopi may not be a single organism. To our knowledge, this is the first study to profile the external microbial consortia cultured from a Cryptobranchid salamander. The incidence of abnormalities/injury and retarded regeneration in C. a. bishopi may have many contributing factors including disease and habitat degradation. Results from this study may provide insight into other amphibian population declines. PMID:22205979

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

    PubMed Central

    2013-01-01

    Background Extended spectrum -lactamases (ESBLs) represent a major group of lactamases responsible for resistance, mostly produced by gram-negative bacteria, to newer generations of -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

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

    PubMed Central

    Payne, David J.; Hueso-Rodrguez, Juan Antonio; Boyd, Helen; Concha, Nstor O.; Janson, Cheryl A.; Gilpin, Martin; Bateson, John H.; Cheever, Christy; Niconovich, Nancy L.; Pearson, Stewart; Rittenhouse, Stephen; Tew, David; Dez, Emilio; Prez, Paloma; de la Fuente, Jesus; Rees, Michael; Rivera-Sagredo, Alfonso

    2002-01-01

    This work describes the discovery and characterization of a novel series of tricyclic natural product-derived metallo-?-lactamase inhibitors. Natural product screening of the Bacillus cereus II enzyme identified an extract from a strain of Chaetomium funicola with inhibitory activity against metallo-?-lactamases. SB236050, SB238569, and SB236049 were successfully extracted and purified from this extract. The most active of these compounds was SB238569, which possessed Ki values of 79, 17, and 3.4 ?M for the Bacillus cereus II, Pseudomonas aeruginosa IMP-1, and Bacteroides fragilis CfiA metallo-?-lactamases, respectively, yet none of the compounds exhibited any inhibitory activity against the Stenotrophomonas maltophilia L-1 metallo-?-lactamase (50% inhibitory concentration > 1,000 ?M). The lack of activity against angiotensin-converting enzyme and serine ?-lactamases demonstrated the selective nature of these compounds. The crystal structure of SB236050 complexed in the active site of CfiA has been obtained to a resolution of 2.5 . SB236050 exhibits key polar interactions with Lys184, Asn193, and His162 and a stacking interaction with the indole ring of Trp49 in the flap, which is in the closed conformation over the active site groove. SB236050 and SB238569 also demonstrate good antibacterial synergy with meropenem. Eight micrograms of SB236050 per ml gave rise to an eightfold drop in the MIC of meropenem for two clinical isolates of B. fragilis producing CfiA, making these strains sensitive to meropenem (MIC ? 4 ?g/ml). Consequently, this series of metallo-?-lactamase inhibitors exhibit the most promising antibacterial synergy activity so far observed against organisms producing metallo-?-lactamases. PMID:12019104

  17. Acquisition and Evolution of Plant PathogenesisAssociated Gene Clusters and Candidate Determinants of Tissue-Specificity in Xanthomonas

    PubMed Central

    Van Sluys, Marie-Anne; White, Frank F.; Ryan, Robert P.; Dow, J. Maxwell; Rabinowicz, Pablo; Salzberg, Steven L.; Leach, Jan E.; Sonti, Ramesh; Brendel, Volker; Bogdanove, Adam J.

    2008-01-01

    Background Xanthomonas is a large genus of plant-associated and plant-pathogenic bacteria. Collectively, members cause diseases on over 392 plant species. Individually, they exhibit marked host- and tissue-specificity. The determinants of this specificity are unknown. Methodology/Principal Findings To assess potential contributions to host- and tissue-specificity, pathogenesis-associated gene clusters were compared across genomes of eight Xanthomonas strains representing vascular or non-vascular pathogens of rice, brassicas, pepper and tomato, and citrus. The gum cluster for extracellular polysaccharide is conserved except for gumN and sequences downstream. The xcs and xps clusters for type II secretion are conserved, except in the rice pathogens, in which xcs is missing. In the otherwise conserved hrp cluster, sequences flanking the core genes for type III secretion vary with respect to insertion sequence element and putative effector gene content. Variation at the rpf (regulation of pathogenicity factors) cluster is more pronounced, though genes with established functional relevance are conserved. A cluster for synthesis of lipopolysaccharide varies highly, suggesting multiple horizontal gene transfers and reassortments, but this variation does not correlate with host- or tissue-specificity. Phylogenetic trees based on amino acid alignments of gum, xps, xcs, hrp, and rpf cluster products generally reflect strain phylogeny. However, amino acid residues at four positions correlate with tissue specificity, revealing hpaA and xpsD as candidate determinants. Examination of genome sequences of xanthomonads Xylella fastidiosa and Stenotrophomonas maltophilia revealed that the hrp, gum, and xcs clusters are recent acquisitions in the Xanthomonas lineage. Conclusions/Significance Our results provide insight into the ancestral Xanthomonas genome and indicate that differentiation with respect to host- and tissue-specificity involved not major modifications or wholesale exchange of clusters, but subtle changes in a small number of genes or in non-coding sequences, and/or differences outside the clusters, potentially among regulatory targets or secretory substrates. PMID:19043590

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

    PubMed

    Daz, Mara 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

  19. Biosynthesis and structural characterization of silver nanoparticles from bacterial isolates

    SciTech Connect

    Zaki, Sahar; El Kady, M.F.; Abd-El-Haleem, Desouky

    2011-10-15

    Graphical abstract: In this study five bacterial isolates belong to different genera were found to be able to biosynthesize silver nanoparticles. Biosynthesis and spectral characterization are reported here. Highlights: {yields} About 300 bacterial isolates were screened for their ability to produce nanosilvers {yields} Five of them were potential candidates for synthesis of silver nanoparticles {yields} Production of silver nanoparticles was examined using UV-Vis, XRD, SEM and EDS. {yields} The presence of nanoparticles with all five bacterial isolates was confirmed. -- Abstract: This study aimed to develop a green process for biosynthesis of silver nanomaterials by some Egyptian bacterial isolates. This target was achieved by screening an in-house culture collection consists of 300 bacterial isolates for silver nanoparticle formation. Through screening process, it was observed that strains belonging to Escherichia coli (S30, S78), Bacillus megaterium (S52), Acinetobacter sp. (S7) and Stenotrophomonas maltophilia (S54) were potential candidates for synthesis of silver nanoparticles. The extracellular production of silver nanoparticles by positive isolates was investigated by UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results demonstrated that UV-visible spectrum of the aqueous medium containing silver ion showed a peak at 420 nm corresponding to the plasmon absorbance of silver nanoparticles. Scanning electron microscopy micrograph showed formation of silver nanoparticles in the range of 15-50 nm. XRD-spectrum of the silver nanoparticles exhibited 2{theta} values corresponding to the silver nanocrystal that produce in hexagonal and cubic crystal configurations with different plane of orientation. In addition, the signals of the silver atoms were observed by EDS-spectrum analysis that confirms the presence of silver nanoparticles (AgNPs) in all positive bacterial isolates.

  20. Prevalent Bacterial Species and Novel Phylotypes in Advanced Noma Lesions

    PubMed Central

    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.

    2002-01-01

    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. PMID:12037085

  1. 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 (MB?.?) and 44/1.4/1 (MB?.?), respectively. Granules of 500-650 ?m 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 MB?.? with a greater C/N/P led to the greatest increase in the starvation period, and the maximum lipid productivity reached 0.057 g/(Lday). Chemical oxygen demand and nitrogen removal in MB?.? 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. PMID:25520170

  2. Antibacterial activities of a fosfomycin/tobramycin combination: a novel inhaled antibiotic for bronchiectasis

    PubMed Central

    MacLeod, David L.; Barker, Lynn M.; Sutherland, Jennifer L.; Moss, Suzanne C.; Gurgel, Jesse L.; Kenney, Thomas F.; Burns, Jane L.; Baker, William R.

    2009-01-01

    Objectives To compare the in vitro and in vivo activities of a 4:1 (w/w) fosfomycin/tobramycin combination (FTI) with those of fosfomycin and tobramycin alone against cystic fibrosis (CF) and non-CF bronchiectasis pathogens. Methods Clinical isolates of CF Pseudomonas aeruginosa, Staphylococcus aureus, Haemophilus influenzae, Stenotrophomonas maltophilia, Burkholderia cepacia complex, Escherichia coli and Klebsiellia spp. were evaluated by MIC, MBC, post-antibiotic effect (PAE), synergy, time–kill, a rat pneumonia model and spontaneous mutation frequency (SMF). Results FTI showed high activity against E. coli, H. influenzae, S. aureus and Klebsiella spp. For the S. aureus strains, 75% of which were methicillin resistant (MRSA), FTI had a lower MIC90 than tobramycin. For P. aeruginosa, FTI had a lower MIC90 than fosfomycin, but tobramycin was more active than either. Synergy studies showed no antagonism between fosfomycin and tobramycin, and 93% of the isolates demonstrated no interaction. FTI was rapidly bactericidal and exhibited concentration-dependent killing in time–kill studies. In the rat pneumonia model, FTI and tobramycin demonstrated bactericidal killing of P. aeruginosa; both were more active than fosfomycin alone. The SMF for S. aureus resistance to FTI was 2–4 log10 lower than that for tobramycin and 2–7 log10 lower than that for fosfomycin. For P. aeruginosa, the FTI SMF was 2–3 log10 lower than that for fosfomycin and 1–2 log10 lower than that for tobramycin. Conclusions FTI is a broad-spectrum antibiotic combination with high activity in vitro and in vivo. These data suggest FTI could be a potential treatment for respiratory infections caused by Gram-positive and Gram-negative aerobic bacteria. PMID:19679597

  3. Exploring nicotinamide cofactor promiscuity in NAD(P)H-dependent flavin containing monooxygenases (FMOs) using natural variation within the phosphate binding loop. Structure and activity of FMOs from Cellvibrio sp. BR and Pseudomonas stutzeri NF13

    PubMed Central

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

    2014-01-01

    Flavin-containing monooxygenases (FMOs) catalyse asymmetric oxidation reactions that have potential for preparative organic synthesis, but most use the more expensive, phosphorylated nicotinamide cofactor NADPH to reduce FAD to FADH2 prior to formation of the (hydro)peroxy intermediate required for substrate oxygenation. A comparison of the structures of NADPH-dependent FMO from Methylophaga aminisulfidivorans (mFMO) and SMFMO from Stenotrophomonas maltophilia, which is able to use both NADPH and NADH, suggested that the promiscuity of the latter enzyme may be due in part to the substitution of an ArgThr couple in the NADPH phosphate recognition site in mFMO, for a GlnHis couple in SMFMO (Jensen et al., 2012, Chembiochem, 13, 872878). Natural variation within the phosphate binding region, and its influence on nicotinamide cofactor promiscuity, was explored through the cloning, expression, characterisation and structural studies of FMOs from Cellvibrio sp. BR (CFMO) and Pseudomonas stutzeri NF13 (PSFMO), which possess ThrSer and GlnGlu in the putative phosphate recognition positions, respectively. CFMO and PSFMO displayed 5- and 1.5-fold greater activity, respectively, than SMFMO for the reduction of FAD with NADH, and were also cofactor promiscuous, displaying a ratio of activity with NADH:NADPH of 1.7:1 and 1:1.3, respectively. The structures of CFMO and PSFMO revealed the context of the phosphate binding loop in each case, and also clarified the structure of the mobile helixloophelix motif that appears to shield the FAD-binding pocket from bulk solvent in this class of FMOs, a feature that was absent from the structure of SMFMO. PMID:25383040

  4. 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

  5. Interactions in biofilms between Listeria monocytogenes and resident microorganisms from food industry premises.

    PubMed

    Carpentier, Brigitte; Chassaing, Danielle

    2004-12-15

    Twenty nine bacterial strains were grown as binary culture biofilms with Listeria monocytogenes to assess their influence on the settlement of the latter on stainless steel coupons. Most of the strains had been isolated from food processing plants after cleaning and disinfection and were tentatively identified by the APILAB Plus 3.3.3 database (bioMerieux). Sixteen of them decreased L. monocytogenes biofilm colony forming units (CFU) counts. Three strains, Bacillus sp. CCL 9 an unidentified Gram-positive strain CCL 59 and Pseudomonas fluorescens E9. 1, led to a 3-log difference in CFU counts between the pure L. monocytogenes biofilms and the mixed biofilms. Eleven strains had no effect and only four, Kocuria varians CCL 73, Staphylococcus capitis CCL 54, Stenotrophomonas maltophilia CCL 47 and Comamonas testosteroni CCL 24, had a positive effect, with a 0.5- to 1.0-log increase in the L. monocytogenes biofilm CFU counts. On its own, L. monocytogenes settled as single cells, but in binary biofilms, different spatial arrangements were observed: (i) with K. varians CCL 73, K. varians CCL 56 and S. capitis CCL 54, L. monocytogenes cells gathered around the microcolonies of the partner strain; (ii) with the two Gram-negative strains, C. testosteroni CCL 24 and CCL 25, L. monocytogenes cells formed its own microcolonies. No link could be found between the exopolysaccharide production capacity of the bacterial strains in pure-culture biofilms and their effect on the L. monocytogenes population in mixed biofilms. With one strain, C. testosteroni CCL 24, adding filter-sterilized supernatant from a pure-culture biofilm to a pure culture of L. monocytogenes increased the number of L. monocytogenes cells adhering to the stainless steel coupons and forming microcolonies. This study suggests that the "house flora" can have a strong effect on the likelihood of finding L. monocytogenes on inert surfaces. PMID:15541798

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

    PubMed

    Farghaly, Ahmed; Tawfik, Ahmed; Danial, Amal

    2016-02-01

    A comparative evaluation of paperboard mill sludge (PMS) versus mixed culture bacteria (MCB) as inoculum for hydrogen production from paperboard mill wastewater (PMW) was investigated. The experiments were conducted at different initial cultivation pHs, inoculums to substrate ratios (ISRs gVS/gCOD), and hydraulic retention times (HRTs). The peak hydrogen yield (HY) of 5.29 ± 0.16 and 1.22 ± 0.11 mmol/gCODinitial was occurred at pH = 5 for MCB and PMS, respectively. At pH of 5, the HY and COD removal achieved the highest values of 2.26 ± 0.14 mmol/gCODinitial and 86 ± 1.6 % at ISR = 6 for MCB, and 2.38 ± 0.25 mmol/gCODinitial and 60.4 ± 2.5 % at ISRs = 3 for PMS. The maximum hydrogen production rate was 93.75 ± 8.9 mmol/day at HRT = 9.6 h from continuous upflow anaerobic reactor inoculated with MCB. Meanwhile, the 16S ribosomal RNA (rRNA) gene fragments indicated a dominance of a novel hydrogen-producing bacterium of Stenotrophomonas maltophilia for PMS microbial community. On the other hand, Escherichia fergusonii and Enterobacter hormaechei were the predominant species for MCB. PMID:26498965

  7. 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.

  8. 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

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

    PubMed

    Heller, D; Helmerhorst, E J; Gower, A C; Siqueira, W L; Paster, B J; Oppenheim, F G

    2016-01-01

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

  10. Synthesis, and antiprotozoal and antibacterial activities of S-substituted 4,6-dibromo- and 4,6-dichloro-2-mercaptobenzimidazoles.

    PubMed

    Andrzejewska, Mariola; Yepez-Mulia, Lilian; Tapia, Amparo; Cedillo-Rivera, Roberto; Laudy, Agnieszka E; Staro?ciak, Bohdan J; Kazimierczuk, Zygmunt

    2004-02-01

    The synthesis and some germicidal activities in vitro of two congener series of S-substituted 4,6-dihalogeno-2-mercapto-1H-benzimidazoles are reported. There was no substantial difference between antibacterial activities of corresponding 4,6-dichloro- and 4,6-dibromo-derivatives. The present results confirm lower susceptibility to substituted benzimidazoles of Gram-negative compared to Gram-positive bacteria. Minimum inhibitory concentrations (MICs) of a majority of the novel derivatives ranged between 25 and 100microg/ml for Gram-positive bacteria. The most active compounds (MICs for Gram-positive bacteria: 0.78-50microg/ml) were 4,6-dichloro-2-(4-nitrobenzylthio)-1H-benzimidazole and 4,6-dibromo-2-(4-nitrobenzylthio)-1H-benzimidazole that were 4-32 times more potent than nitrofurantoin against all Gram-positive bacteria utilized but Escherichia faecalis, against which they were, respectively, 2 and 4 times less potent than nitrofurantoin. Among Gram-negative bacteria used, Stenotrophomonas maltophilia and Bordetella bronchiseptica were most sensitive (as evidenced by a number of MICs 400microg/ml). All the new compounds were at least several times more active against Giardia intestinalis (IC(50): 0.006-0.053microg/ml), and a half of them were at least several times more active against Trichomonas vaginalis (IC(50): 0.0015-0.182microg/ml) than metronidazole (IC(50): 0.210 and 0.037microg/ml, respectively), the drug of choice in the treatment of G. intestinalis and T. vaginalis infections. PMID:14757505

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

    PubMed

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

    2015-01-01

    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 ?g mL(-1)) of indole-3-acetic acid, while significant acetylene reduction activities (1.79-4.9 ?mole 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

  12. Composting and vermicomposting experiences in the treatment and bioconversion of asphaltens from the Prestige oil spill.

    PubMed

    Martín-Gil, Jesús; Navas-Gracia, Luís Manuel; Gómez-Sobrino, Ernesto; Correa-Guimaraes, Adriana; Hernández-Navarro, Salvador; Sánchez-Báscones, Mercedes; del Carmen Ramos-Sánchez, María

    2008-04-01

    This work illustrates the effectiveness of composting and vermicomposting in degrading fuel-in-water emulsions from oil spills (chapapote), and the isolation of potentially useful microorganisms for its biodegradation. Firstly, an alternative to the biodegradation of asphaltens from the Prestige oil spill (still present in some chapapote rafts in the Cantabrian coast) by means of the application of composting techniques to a microbial partnership acclimated to fuel-oil is offered. Our aim is that, after a relatively short period of time, the microorganisms can obtain its source of carbon and energy from asphaltens. The addition of metabolic co-substrates, like cow bed and potato peelings, allows the fragmentation of complex compounds into smaller structures, susceptible to further degradation. Afterwards, a maturation of the compost by means of a treatment with earthworms (Eisenia foetida) is necessary. Thus, through the vermicomposting it will be possible to obtain a valued product, useful in the processes of ground amendment, with little presence of asphaltens and occluded polycyclic aromatic hydrocarbons, rich in humus, and with an important bacterial flora of Bacillus genera, so that it can be typical of co-activators and accelerating products in composting processes. Along with this article, we show some parameters that control the evolution of the compost products (evolved gases, acidity, temperature and humidity); the chemical and microbiological analytical results; and the germination assays of vermicomposting. Results reveal that by using microorganisms living in either earthworm intestines (Stenotrophomonas maltophilia) or vermiculture substrates (Scedosporium apiospermium), it is possible to degrade and to eliminate the polycyclic asphaltens into CO(2) and H(2)O, helped by evaporation, dissolution and/or photo-oxidation processes. The obtained end product has contents of interesting vegetal nutrients and, mainly, it displays very high germination indices. PMID:17512195

  13. Rapid Automated Microscopy for Microbiological Surveillance of Ventilator-associated Pneumonia

    PubMed Central

    Price, Connie S.; Overdier, Katherine H.; Wolken, Robert F.; Metzger, Steven W.; Hance, Kenneth R.; Howson, David C.

    2015-01-01

    Rationale: Diagnosis of ventilator-associated pneumonia (VAP) is imprecise. Objectives: To (1) determine whether alternate-day surveillance mini–bronchoalveolar lavage (mini-BAL) in ventilated adults could reduce time to initiation of targeted treatment and (2) evaluate the potential for automated microscopy to reduce analysis time. Methods: Adult intensive care unit patients who were anticipated to require ventilation for at least a further 48 hours were included. Mini-BALs were processed for identification, quantitation, and antibiotic susceptibility, using (1) clinical culture (50 ± 7 h) and (2) automated microscopy (∼5 h plus offline analysis). Measurements and Main Results: Seventy-seven mini-BALs were performed in 33 patients. One patient (3%) was clinically diagnosed with VAP. Of 73 paired samples, culture identified 7 containing pneumonia panel bacteria (>104 colony-forming units/ml) from five patients (15%) (4 Staphylococcus aureus [3 methicillin-resistant S. aureus], 2 Stenotrophomonas maltophilia, 1 Klebsiella pneumoniae) and resulted in antimicrobial changes/additions to two of five (40%) of those patients. Microscopy identified 7 of 7 microbiologically positive organisms and 64 of 66 negative samples compared with culture. Antimicrobial responses were concordant in four of five comparisons. Antimicrobial changes/additions would have occurred in three of seven microscopy-positive patients (43%) had those results been clinically available in 5 hours, including one patient diagnosed later with VAP despite negative mini-BAL cultures. Conclusions: Microbiological surveillance detected infection in patients at risk for VAP independent of clinical signs, resulting in changes to antimicrobial therapy. Automated microscopy was 100% sensitive and 97% specific for high-risk pneumonia organisms compared with clinical culturing. Rapid microscopy-based surveillance may be informative for treatment and antimicrobial stewardship in patients at risk for VAP. PMID:25585163

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

    PubMed

    Flores, Mara R; Ordoez, Omar F; Maldonado, Marcos J; Faras, Mara 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

  15. 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

  16. Novel Cyclic di-GMP Effectors of the YajQ Protein Family Control Bacterial Virulence

    PubMed Central

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

    2014-01-01

    Bis-(3′,5′) cyclic di-guanylate (cyclic di-GMP) is a key bacterial second messenger that is implicated in the regulation of many critical processes that include motility, biofilm formation and virulence. Cyclic di-GMP influences diverse functions through interaction with a range of effectors. Our knowledge of these effectors and their different regulatory actions is far from complete, however. Here we have used an affinity pull-down assay using cyclic di-GMP-coupled magnetic beads to identify cyclic di-GMP binding proteins in the plant pathogen Xanthomonas campestris pv. campestris (Xcc). This analysis identified XC_3703, a protein of the YajQ family, as a potential cyclic di-GMP receptor. Isothermal titration calorimetry showed that the purified XC_3703 protein bound cyclic di-GMP with a high affinity (Kd∼2 µM). Mutation of XC_3703 led to reduced virulence of Xcc to plants and alteration in biofilm formation. Yeast two-hybrid and far-western analyses showed that XC_3703 was able to interact with XC_2801, a transcription factor of the LysR family. Mutation of XC_2801 and XC_3703 had partially overlapping effects on the transcriptome of Xcc, and both affected virulence. Electromobility shift assays showed that XC_3703 positively affected the binding of XC_2801 to the promoters of target virulence genes, an effect that was reversed by cyclic di-GMP. Genetic and functional analysis of YajQ family members from the human pathogens Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed that they also specifically bound cyclic di-GMP and contributed to virulence in model systems. The findings thus identify a new class of cyclic di-GMP effector that regulates bacterial virulence. PMID:25329577

  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. Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry: rapid identification of bacteria isolated from patients with cystic fibrosis.

    PubMed

    Baillie, S; Ireland, K; Warwick, S; Wareham, D; Wilks, M

    2013-01-01

    Despite extensive research into the diagnosis and management of cystic fibrosis (CF) over the past decades, sufferers still have a median life expectancy of less than 37 years. Respiratory tract infections have a significant role in increasing the morbidity and mortality of patients with CF via a progressive decline in lung function. Rapid identification of organisms recovered from CF sputum is necessary for effective management of respiratory tract infections; however, standard techniques of identification are slow, technically demanding and expensive. The aim of this study is to asses the suitability of matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS) in identifying bacteria isolated from the respiratory tract of patients with CF, and is assessed by testing the accuracy of MALDI-TOF MS in identifying samples from a reference collection of rare CF strains in conjunction with comparing MALDI-TOF MS and standard techniques in identifying clinical isolates from sputum samples of CF patients. MALDI-TOF MS accurately identified 100% of isolates from the reference collection of rare CF pathogens (EuroCare CF collection). The isolate identification given by MALDI-TOF MS agreed with that given by standard techniques for 479/481 (99.6%) clinical isolates obtained from respiratory samples provided by patients with CE In two (0.4%) of 481 samples there was a discrepancy in identification between MALDI-TOF MS and standard techniques. One organism was identified as Pseudomonas aeruginosa by MALDI-TOF but could only be identified by the laboratory's standard methods as of the Pseudomonas genus. The second organism was identified as P. beteli by MALDI-TOF MS and Stenotrophomonas maltophilia by standard methods. This study shows that MALDI-TOF MS is superior to standard techniques in providing cheap, rapid and accurate identification of CF sputum isolates. PMID:24400425

  19. [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; Fernndez, A; Zudiker, R; Echeverra, A; Nagel, C; del Castillo, M; Lpez, 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 Fundacin Favaloro, the Fundacin para la Lucha contra las Enfermedades Neurolgicas de la Infancia and the Hospital de Nios Ricardo Gutirrez. 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 cost expensive. PMID:11594009

  20. Fate of plasmid-bearing, luciferase marker gene tagged bacteria after feeding to the soil microarthropod Onychiurus fimatus (Collembola).

    PubMed

    Hoffmann; Thimm; Tebbe

    1999-10-01

    In order to study the potential impact of the soil microarthropod Onychiurus fimatus (Collembola) on the microbial community, we analysed the fate of luciferase marker gene tagged bacterial strains fed to young adult specimens in petri dish microcosm experiments. In faeces collected from O. fimatus, Escherichia coli S17-1/pRP4luc and Sinorhizobium meliloti L33 were only detectable for 2 days after feeding whereas strain HR2/pRP4luc, a close relative of Stenotrophomonas maltophilia, isolated from another collembolan species, could be detected for 16 days. The amount of shed cells of strain HR2 increased during the frequent releases of the cast-off skins (exuvia). In order to analyse whether gut associated bacteria could serve as recipients for mobile genetic elements, plasmid-bearing E. coli donor strains were incubated with faeces in filter mating-like experiments and, in other experiments, directly fed to O. fimatus specimens. Transconjugants were obtained with both the conjugative self-transferable broad host range plasmid pRP4luc and the mobilisable (Mob(+)) broad host range plasmid pSUP104luc, the latter, however, only with a mobilising donor strain. No transfer was detected with the narrow host range plasmids pSUP202luc (Mob(+)), pUC18luc (Mob(-)), or with the broad host range transposon delivery plasmid pUTluxCDABE (Mob(+)). Transconjugants of pRP4luc were detected within one day of the beginning of a feeding experiment and then throughout the incubation period of two weeks, with gaps of no detection after 5, 12 and 14 days, probably caused by moulting. The results of this study indicate that feeding activities of collembola can modify the structure of soil-inhabiting microbial communities and enhance the spread of plasmids from non-indigenous to indigenous soil bacteria. PMID:10508937

  1. Bacterial resistance control on mineral surfaces of hydroxyapatite and human teeth via surface charge-driven antifouling coatings.

    PubMed

    Venault, Antoine; Yang, Hui-Shan; Chiang, Yen-Che; Lee, Bor-Shuinn; Ruaan, Ruoh-Chyu; Chang, Yung

    2014-03-12

    This works reports a set of new functionalized polyethyleneimine (PEI) polymers, including a neutral PEGylated polymer PEI-g-PEGMA, a negatively charged polymer PEI-g-SA, and a zwitterionic polymer PEI-g-SBMA, and their use as antibiofouling coating agent for human teeth protection. Polymers were synthesized by Michael addition, XPS analysis revealed that each polymer could be efficiently coated onto hydroxyapatite, ceramic material used as a model tooth. Polymers carrying a negative net charge were more efficiently adsorbed, because of the establishment of electrostatic interactions with calcium ions. Protein adsorption tests revealed that two factors were important in the reduction of protein adsorption. Both the surface charge and the surface ability to bind and entrap water molecules had to be considered. PEI-g-SBMA, which zeta potential in PBS solution was negative, was efficient to inhibit the adsorption of BSA, a negative protein. On the other hand, it also resisted the adsorption of lysozyme, a positive protein, because zwitterionic molecules can easily entrap water and provide a very hydrophilic environment. Streptococcus mutans attachment tests performed unveiled that all modified polymers were efficient to resist this type of bacteria responsible for dental carries. Best results were also obtained with PEI-g-SBMA coating. This polymer was also shown to efficiently resist the adsorption of positively charged bacteria (Stenotrophomonas maltophilia). Tests performed on real human tooth showed that PEI-g-SBMA could inhibit up to 70% of bacteria adhesion, which constitutes a major result considering that surface of teeth is very rough, therefore physically promoting the attachment of proteins and bacteria. PMID:24513459

  2. Microbial Contamination of Glaucoma Eyedrops Used by Patients Compared With Ocular Medications Used in the Hospital

    PubMed Central

    Teuchner, Barbara; Wagner, Julia; Bechrakis, Nikolaos E.; Orth-Hller, Dorothea; Nagl, Markus

    2015-01-01

    Abstract The aim of this study was to compare the percentage of contamination of multiuse eyedrops applied by glaucoma patients at home and by the medical personnel at the outpatient department, the ward, and the operating room of our Department of Ophthalmology. Eyedrops were collected over a period of 11 months. Samples were taken from the dropper tip (smear), drops, and the residual fluid inside the bottle and cultivated on blood agar. Colony forming units were counted and identified by mass spectrometry. The percentage of contamination was significantly higher in eyedrops applied by the patients (29/119; 24.4%, P?Stenotrophomonas maltophilia, and Staphylococcus aureus) were found only in 6 bottles (1.5%), whereas most of the detected microbes belonged to human or environmental flora. This study underlines the importance of hygienic handling of eyedrops and raises the question of whether single-use glaucoma medication might be preferred to reduce the risk of contamination. PMID:25715262

  3. 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

  4. Mechanisms of antimicrobial resistance in Gram-negative bacilli.

    PubMed

    Ruppé, Étienne; Woerther, Paul-Louis; Barbier, François

    2015-12-01

    The burden of multidrug resistance in Gram-negative bacilli (GNB) now represents a daily issue for the management of antimicrobial therapy in intensive care unit (ICU) patients. In Enterobacteriaceae, the dramatic increase in the rates of resistance to third-generation cephalosporins mainly results from the spread of plasmid-borne extended-spectrum beta-lactamase (ESBL), especially those belonging to the CTX-M family. The efficacy of beta-lactam/beta-lactamase inhibitor associations for severe infections due to ESBL-producing Enterobacteriaceae has not been adequately evaluated in critically ill patients, and carbapenems still stands as the first-line choice in this situation. However, carbapenemase-producing strains have emerged worldwide over the past decade. VIM- and NDM-type metallo-beta-lactamases, OXA-48 and KPC appear as the most successful enzymes and may threaten the efficacy of carbapenems in the near future. ESBL- and carbapenemase-encoding plasmids frequently bear resistance determinants for other antimicrobial classes, including aminoglycosides (aminoglycoside-modifying enzymes or 16S rRNA methylases) and fluoroquinolones (Qnr, AAC(6')-Ib-cr or efflux pumps), a key feature that fosters the spread of multidrug resistance in Enterobacteriaceae. In non-fermenting GNB such as Pseudomonas aeruginosa, Acinetobacter baumannii and Stenotrophomonas maltophilia, multidrug resistance may emerge following the sole occurrence of sequential chromosomal mutations, which may lead to the overproduction of intrinsic beta-lactamases, hyper-expression of efflux pumps, target modifications and permeability alterations. P. aeruginosa and A. baumannii also have the ability to acquire mobile genetic elements encoding resistance determinants, including carbapenemases. Available options for the treatment of ICU-acquired infections due to carbapenem-resistant GNB are currently scarce, and recent reports emphasizing the spread of colistin resistance in environments with high volume of polymyxins use elicit major concern. PMID:26261001

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

    PubMed

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

    2013-11-01

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

  6. In vivo development of daptomycin resistance in vancomycin-susceptible methicillin-resistant Staphylococcus aureus severe infections previously treated with glycopeptides.

    PubMed

    Capone, A; Cafiso, V; Campanile, F; Parisi, G; Mariani, B; Petrosillo, N; Stefani, S

    2016-04-01

    Our aim was to describe the clinical and microbiological features of four cases of severe vancomycin-susceptible methicillin-resistant Staphylococcus aureus (MRSA) infections in which the vancomycin non-susceptibility development and daptomycin resistance occurred under therapy with teicoplanin (three cases) and daptomycin switched to vancomycin (one case). Clinical data were retrospectively reviewed. On nine clinical epidemiologically unrelated daptomycin-susceptible (DAP-S) and daptomycin-resistant (DAP-R) MRSA, we performed: (i) DAP-VAN-TEC-CFX-RIF minimum inhibitory concentrations (MICs); (ii) glycopeptide resistance detection (GRD) by δ-hemolysis; (iii) glycopeptide population analysis; (iv) molecular characterization by PFGE-MLST-SCCmec-agr-typing; (v) rpoB and mprF single nucleotide polymorphisms (SNPs); (vi) dltA-mprF-atl-sceD expression by real-time quantitative polymerase chain reaction (qPCR). Three out of the four patients did not survive despite salvage treatment; two died with active MRSA infection and one died because of Stenotrophomonas maltophilia sepsis. The fourth patient, in which a reversion to a DAP-S phenotype occurred, survived with daptomycin plus trimethoprim/sulfamethoxazole and oxacillin treatment, and endovascular device removal. Daptomycin resistance development was preceded by a stable heterogeneous vancomycin-intermediate S. aureus (hVISA) or VISA phenotype acquisition, while in one case, daptomycin resistance was preceded by an unstable daptomycin heteroresistance (hDAP) behavior reverting to DAP-S during vancomycin plus rifampin therapy followed by high doses of daptomycin. All DAP-R strains showed hVISA or DAP-R traits, including mutations and/or up-regulation of genes involved in cell wall turnover and cell membrane perturbation. In our study, daptomycin resistance arose during glycopeptide therapy. The emergence of DAP-R isolates was preceded by a stable VISA or hVISA phenotype or by instability reverting to a DAP-S heteroresistant phenotype. Daptomycin, as first-line therapy for the treatment of severe MRSA infections, should be used at optimal dosage combined with other agents such as beta-lactams, to prevent daptomycin resistance occurrence. PMID:26815434

  7. Ceftobiprole activity against over 60,000 clinical bacterial pathogens isolated in Europe, Turkey, and Israel from 2005 to 2010.

    PubMed

    Farrell, David J; Flamm, Robert K; Sader, Helio S; Jones, Ronald N

    2014-07-01

    Ceftobiprole medocaril is a newly approved drug in Europe for the treatment of hospital-acquired pneumonia (HAP) (excluding patients with ventilator-associated pneumonia but including ventilated HAP patients) and community-acquired pneumonia in adults. The aim of this study was to evaluate the in vitro antimicrobial activity of ceftobiprole against prevalent Gram-positive and -negative pathogens isolated in Europe, Turkey, and Israel during 2005 through 2010. A total of 60,084 consecutive, nonduplicate isolates from a wide variety of infections were collected from 33 medical centers. Species identification was confirmed, and all isolates were susceptibility tested using reference broth microdilution methods. Ceftobiprole had high activity against methicillin-susceptible Staphylococcus aureus (MSSA) (100.0% susceptible), methicillin-susceptible coagulase-negative staphylococci (CoNS), beta-hemolytic streptococci, and Streptococcus pneumoniae (99.3% susceptible), with MIC90 values of 0.25, 0.12, ? 0.06, and 0.5 ?g/ml, respectively. Ceftobiprole was active against methicillin-resistant S. aureus (MRSA) (98.3% susceptible) and methicillin-resistant CoNS, having a MIC90 of 2 ?g/ml. Ceftobiprole was active against Enterococcus faecalis (MIC50/90, 0.5/4 ?g/ml) but not against most Enterococcus faecium isolates. Ceftobiprole was very potent against the majority of Enterobacteriaceae (87.3% susceptible), with >80% inhibited at ? 0.12 ?g/ml. The potency of ceftobiprole against Pseudomonas aeruginosa (MIC50/90, 2/>8 ?g/ml; 64.6% at MIC values of ? 4 ?g/ml) was similar to that of ceftazidime (MIC50/90, 2/>16 ?g/ml; 75.4% susceptible), but limited activity was observed against Acinetobacter spp. and Stenotrophomonas maltophilia. High activity was also observed against all Haemophilus influenzae (MIC90, ? 0.06 ?g/ml) and Moraxella catarrhalis (MIC50/90, ? 0.06/0.25 ?g/ml) isolates. Ceftobiprole demonstrated a wide spectrum of antimicrobial activity against this very large longitudinal sample of contemporary pathogens. PMID:24777091

  8. Multidrug-resistant Gram-negative infections: what are the treatment options?

    PubMed

    Giamarellou, Helen; Poulakou, Garyphallia

    2009-10-01

    The emergence of multidrug-resistant (MDR) Gram-negative bacilli creates a challenge in the treatment of nosocomial infections. While the pharmaceutical pipeline is waning, two revived old antibacterials (colistin and fosfomycin), a newer one (tigecycline) and an 'improved' member of an existing class (doripenem) are the only therapeutic options left. The class of polymyxins, known since 1947 and represented mostly by polymyxin B and polymyxin E (colistin), has recently gained a principal role in the treatment of the most problematic MDR Gram-negative pathogens (such as Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae and Stenotrophomonas maltophilia). Future prospective studies are needed to answer important clinical questions, such as the possible benefit of combination with other antimicrobials versus monotherapy, the efficacy of colistin in neutropenic hosts and the role of inhaled colistin. As new pharmacokinetic data emerge, clarification of the pharmacokinetic/pharmacodynamic (PK/PD) profile of colistin as well as appropriate dosing seems urgent, while development of resistance must be carefully monitored. Fosfomycin tromethamine, a synthetic salt of fosfomycin discovered in 1969, has regained attention because of its in vitro activity against extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae and MDR P. aeruginosa. Although in use for decades in oral and parenteral formulations for a variety of infections without significant toxicity, its clinical utility in MDR infections remains to be explored in future studies. Tigecycline, the first representative of the new class of glycylcyclines, holds promise in infections from MDR K. pneumoniae (K. pneumoniae carbapenemase [KPC]- and ESBL-producing strains) and Enterobacteriaceae with various mechanisms of resistance. The in vitro activity of tigecycline against A. baumannii makes it a tempting option, as it is currently the most active compound against MDR strains along with colistin. However, the usual minimum inhibitory concentration values of this pathogen are approximately 2 mg/L and compromise clinical outcomes based on PK/PD issues. Its advantageous penetration into various tissues is useful in infections of the skin and soft tissues as well as intra-abdominal infections (official indications), whereas low serum concentrations compromise its use in bloodstream infections. Therefore, prospective studies with dose escalation are urgently needed, as well as clarification of its role in nosocomial pneumonia, after poor results in the study of ventilator-associated pneumonia. Finally, doripenem, the recently licensed member of the carbapenems (without significant spectrum alterations from the ascendant members) seems to possess a lower potential for resistance selection and a more favourable pharmacokinetic profile when given as an extended infusion. The latter strategy could prove helpful in overcoming low level resistance of A. baumannii and P. aeruginosa strains. PMID:19747006

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

    PubMed

    Emerson, D; Moyer, C

    1997-12-01

    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

  10. Epidemiology of bacteremia caused by uncommon non-fermentative gram-negative bacteria

    PubMed Central

    2013-01-01

    Background Prevalence of bacteremia caused by non-fermentative gram-negative bacteria (NFGNB) has been increasing over the past decade. Although many studies have already investigated epidemiology of NFGNB bacteremia, most focused only on common NFGNB including Pseudomonas aeruginosa (PA) and Acinetobacter baumannii (AB). Knowledge of uncommon NFGNB bacteremia is very limited. Our study aimed to investigate epidemiology and identify factors associated with uncommon NFGNB bacteremia. Methods This observational study was conducted at a university hospital in Thailand during July 1, 2007-Dec 31, 2008. All patients who had at least one blood culture positive for NFGNB and met the criteria for systemic inflammatory response syndrome within 24hours before/after obtaining the blood culture were enrolled. The NFGNB isolates that could not be satisfactorily identified by the standard biochemical assays were further characterized by molecular sequencing methods. To identify factors associated with uncommon NFGNB bacteremia, characteristics of patients in the uncommon NFGNB group were subsequently compared to patients in the common NFGNB group (AB and PA bacteremia). Results Our study detected 223 clinical isolates of NFGNB in 221 unique patients. The major causative pathogens were AB (32.7%), followed by PA (27.8%), Stenotrophomonas maltophilia (5.4%), Acinetobacter lwoffii (4.9%) and Burkholderia pseudomallei (2.7%). Infection-related mortality was 63.0% in the AB group, 40.3% in the PA group and 17.4% in the uncommon NFGNB group. Factors associated with uncommon NFGNB bacteremia (OR [95% CI]; p-value) were male sex (0.28 [0.14-0.53]; p?

  11. Combination of chromogenic differential medium and estA-specific PCR for isolation and detection of phytopathogenic Xanthomonas spp.

    PubMed

    Lee, Yung-An; Sung, Ai-Ning; Liu, Tzu-Fen; Lee, Yung-Shan

    2009-11-01

    A xanthomonad differential medium (designated Xan-D medium) was developed, on which streaks and colonies of xanthomonads, including 13 species of the genus Xanthomonas, turned wet-shining yellow-green and were surrounded with a smaller milky zone and a bigger clear zone in 3 to 4 days. The characteristics could easily be differentiated from those of yellow nonxanthomonads and other bacteria. The mechanism of color change and formation of a milky zone on the medium are mainly due to the Tween 80 hydrolytic capacity of xanthomonads. The gene, estA, responsible for Tween 80 hydrolysis was cloned and expressed in Escherichia coli, which acquired a capacity to hydrolyze Tween 80 and could turn green and form a milky zone on the Xan-D medium. The nucleotide sequence of estA is highly conserved in the xanthomonads, and the sequence was used to design a specific PCR primer set. The PCR amplification using the primer set amplified a 777-bp specific DNA fragment for all xanthomonad strains tested. The Xan-D medium was used to isolate and differentiate Xanthomonas campestris pv. campestris from naturally infected cabbages with black rot symptoms for a rapid diagnosis. All isolated X. campestris pv. campestris strains developed characteristic colonies and were positive in the PCR with the estA primer set. The Xan-D medium was further amended with antibiotics and successfully used for the detection of viable X. campestris pv. campestris cells from plant seeds. Although some yellow nonxanthomonads and other saprophytic bacteria from plant seeds could still grow on the medium, they did not interfere with the color development of X. campestris pv. campestris. However, Stenotrophomonas maltophilia, which is closely related to xanthomonads, existing in a seed lot could also develop yellow-green color but had different colony morphology and was negative in the PCR with the estA primer set. Accordingly, the combination of the Xan-D medium with the estA-specific PCR is a useful and reliable method for the isolation and detection of viable xanthomonad cells from plant materials. PMID:19749062

  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

    Since the Physicians start use of antibiotics long ago with un-notice drug resistance. However actual problem was recognized about 85 years ago. Antibiotic resistant and Multi-drug resistant bacterial strains are at rise throughout the world. It is physicians and researchers to take scientific research based appropriate action to overcome this ever-spreading problem. This study is designed to find out sensitive (S), resistant (R) and multi-drug resistant (MDR) Acinetobacter baumanii strain along with other isolates in the resident patients of Eastern Region of Saudi Arabia. Pseudomonas aeruginosa is excluded from other gram-negative organisms isolated from different sites as it will be dealt separately. This study is based in was retrospective observations designed to collect data of different stains of Acinetobacter baumanii with reference to their Sensitivity (S), Resistance (R), Multi-Drug Resistance (MDR) along with other Gram negative isolated from different sites (from 1st January 2004 to 31st December 2011) at King Abdulaziz Hospital located Eastern Region of Kingdom of Saudi Arabia (KSA). All necessary techniques were used to culture and perform sensitivity of these isolates. There were 4532 isolates out of which 3018 (67%) were from patients. Out of Acinetobacter baumanii infected were 906 (20%) while other 3626 (80%) isolates were miscellaneous. Numbers of patients or cases were 480 (53%) out of 906 isolates and numbers of patients or cases in other organisms were 2538 (70%) out of 3626 isolates. Acinetobacter baumanii infected patients 221 (46%) were male and 259 (54%) were female and the male and female ratio of 1:1.2. In other organisms this male female ratio was almost same. There was steady rise in number of patients and the hence the isolates from 2004 to 2011. Majority of the bacterial strains were isolated as single organism but some were isolated as double or triple or quadruple or more organisms from different sites. Sensitive, Resistant and Multi-Drug Resistant Acinetobacter baumanii have been isolated from different sites. The other Gram negative isolates included Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Klebsiella oxytoca, Serratia marcescens and Stenotrophomonas maltophilia. A significant rise in R and MDR but there is rise in R and MDR Acinetobacter baumanii Strains has been interceded other isolates. It is important to adopt proper and sustainable policies and guideline regarding antibiotics prescription and used. We should also check our infection control practices in our hospital or healthcare settings. We should start antibiotics stewardship in our hospital in order to reducing or overcoming antibiotics Resistant (R) and Multi-Drug Resistant (MDR) strains prevalence. PMID:26004714

  13. Update on Acinetobacter species: mechanisms of antimicrobial resistance and contemporary in vitro activity of minocycline and other treatment options.

    PubMed

    Castanheira, Mariana; Mendes, Rodrigo E; Jones, Ronald N

    2014-12-01

    Among Acinetobacter species, A. baumannii and other closely related species are commonly implicated in nosocomial infections. These organisms are usually multidrug resistant (MDR), and therapeutic options to treat A. baumannii infections are very limited. Clinicians have been resorting to older antimicrobial agents to treat infections caused by MDR A. baumannii, and some of these agents have documented toxicity and/or are not optimized for the infection type to be treated. Recent clinical experience supported by antimicrobial susceptibility data suggests that minocycline has greater activity than other tetracyclines and glycylcyclines against various MDR pathogens that have limited therapeutic options available, including Acinetobacter species. An intravenous formulation of minocycline has recently become available for clinical use, and in contrast to most older tetracyclines, minocycline has high activity against Acinetobacter species. In this report, we summarized some of the characteristics of the tetracycline class, and quantified the minocycline activity against contemporary (2007-2011) isolates and its potential therapeutic role against a collection of 5477 A. baumannii and other relevant gram-negative organisms when compared directly with tetracycline, doxycycline, and other broad-spectrum antimicrobial agents. Acinetobacter baumannii strains were highly resistant to all agents tested, with the exception of minocycline (79.1% susceptible) and colistin (98.8% susceptible). Minocycline (minimum inhibitory concentration that inhibits 50% and 90% of the isolates [MIC(50/90)]: 1/8 g/mL) displayed greater activity than doxycycline (MIC(50/90): 2/>8 g/mL) and tetracycline hydrochloride (HCL) (only 30.2% susceptible) against A. baumannii isolates, and was significantly more active than other tetracyclines against Burkholderia cepacia, Escherichia coli, Serratia marcescens, and Stenotrophomonas maltophilia isolates. In vitro susceptibility testing using tetracycline HCL as a surrogate for the susceptibility other tetracyclines fails to detect minocycline-susceptible isolates and the potential utility of minocycline for the treatment of many MDR A. baumannii infections and other difficult-to-treat species, where there are often limited choices of antimicrobials. PMID:25371512

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

    PubMed Central

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

    2009-01-01

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

  15. 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

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

    SciTech Connect

    Pinzon, NM; Aukema, KG; Gralnick, JA; Wackett, LP

    2011-06-28

    A method for use in high-throughput screening of bacteria for the production of long-chain hydrocarbons and ketones by monitoring fluorescent light emission in the presence of Nile red is described. Nile red has previously been used to screen for polyhydroxybutyrate (PHB) and fatty acid esters, but this is the first report of screening for recombinant bacteria making hydrocarbons or ketones. The microtiter plate assay was evaluated using wild-type and recombinant strains of Shewanella oneidensis and Escherichia coli expressing the enzyme OleA, previously shown to initiate hydrocarbon biosynthesis. The strains expressing exogenous Stenotrophomonas maltophilia oleA, with increased levels of ketone production as determined by gas chromatography-mass spectrometry, were distinguished with Nile red fluorescence. Confocal microscopy images of S. oneidensis oleA-expressing strains stained with Nile red were consistent with a membrane localization of the ketones. This differed from Nile red staining of bacterial PHB or algal lipid droplets that showed intracellular inclusion bodies. These results demonstrated the applicability of Nile red in a high-throughput technique for the detection of bacterial hydrocarbons and ketones. IMPORTANCE In recent years, there has been renewed interest in advanced biofuel sources such as bacterial hydrocarbon production. Previous studies used solvent extraction of bacterial cultures followed by gas chromatography-mass spectrometry (GC-MS) to detect and quantify ketones and hydrocarbons (Beller HR, Goh EB, Keasling JD, Appl. Environ. Microbiol. 76: 1212-1223, 2010; Sukovich DJ, Seffernick JL, Richman JE, Gralnick JA, Wackett LP, Appl. Environ. Microbiol. 76: 3850-3862, 2010). While these analyses are powerful and accurate, their labor-intensive nature makes them intractable to high-throughput screening; therefore, methods for rapid identification of bacterial strains that are overproducing hydrocarbons are needed. The use of high-throughput evaluation of bacterial and algal hydrophobic molecule production via Nile red fluorescence from lipids and esters was extended in this study to include hydrocarbons and ketones. This work demonstrated accurate, high-throughput detection of high-level bacterial long-chain ketone and hydrocarbon production by screening for increased fluorescence of the hydrophobic dye Nile red.

  17. Application of a constructed wetland system for polluted stream remediation

    NASA Astrophysics Data System (ADS)

    Tu, Y. T.; Chiang, P. C.; Yang, J.; Chen, S. H.; Kao, C. M.

    2014-03-01

    In 2010, the multi-function Kaoping River Rail Bridge Constructed Wetland (KRRBW) was constructed to improve the stream water quality and rehabilitate the ecosystem of the surrounding environment of Dashu Region, Kaohsiung, Taiwan. The KRRBW consists of five wetland basins with a total water surface area of 15 ha, a total hydraulic retention time (HRT) of 10.1 days at a averaged flow rate of 14 740 m3/day, and an averaged water depth of 1.1 m. The influent of KRRBW coming from the local drainage systems containing untreated domestic, agricultural, and industrial wastewaters. Based on the quarterly investigation results of water samples taken in 2011-2012, the overall removal efficiencies were 91% for biochemical oxygen demand (BOD), 75% for total nitrogen (TN), 96% for total phosphorus (TP), and 99% for total coliforms (TC). The calculated first-order decay rates for BOD, TN, TP, NH3-N, and TC ranged from 0.14 (TN) to 0.42 (TC) 1/day. This indicates that the KRRBW was able to remove organics, TC, and nutrients effectively. The high ammonia/nitrate removal efficiency indicates that nitrification and denitrification processes occurred simultaneously in the wetland system, and the detected nitrite concentration confirmed the occurrence of denitrification/nitrification. Results from sediment analyses reveal that the sediment contained high concentrations of organics (sediment oxygen demand = 1.9-5.2 g O2/m2 day), nutrients (up to 15.8 g total nitrogen/kg of sediment and 1.48 g total phosphorus/kg of sediment), and metals (up to 547 mg/kg of Zn and 97 mg/kg of Cu). Appropriate wetland management strategies need to be developed to prevent the release of contaminants into the wetland system. The wetland system caused the variations in the microbial diversities and dominant microbial bacteria. Results show the dominant nitrogen utilization bacteria including Denitratisoma oestradiolicum, Nitrosospira sp., Nitrosovibrio sp., D. oestradiolicum, Alcaligenes sp., Steroidobacter denitrificans, Hydrocarboniphaga effuse were responsible for nitrogen removal, and the dominant carbon degrading bacteria (Stenotrophomonas maltophilia, H. effuse, Alcaligenes sp., Pseudomonas sp., Fusibacter sp., Chlofoflexi, Guggenheimella bovis, Bacillus pumilus) were responsible for carbon reduction. The denaturing gradient gel electrophoresis (DGGE) and nucleotide sequence techniques provide a guide for microbial ecology evaluation, which can be used as an indication of contaminants removal. Results from this study show that constructed wetlands have the potential to be developed into an environmentally acceptable river water quality improvement and wastewater polishment alternative for practical application.

  18. Multispecies Biofilm Development on Space Station Heat Exhanger Core Material

    NASA Technical Reports Server (NTRS)

    Pyle, B. H.; Roth, S. R.; Vega, L. M.; Pickering, K. D.; Alvarez, Pedro J. J.; Roman, M. C.

    2007-01-01

    Investigations of microbial contamination of the cooling system aboard the International Space Station (ISS) suggested that there may be a relationship between heat exchanger (HX) materials and the degree of microbial colonization and biofilm formation. Experiments were undertaken to test the hypothesis that biofilm formation is influenced by the type and previous exposure of HX surfaces. Acidovorax delafieldii, Comamonas acidovorans, Hydrogenophaga pseudoflava, Pseudomonas stutzeri, Sphingomonas paucimobilis, and Stenotrophomonas maltophilia, originally isolated from ISS cooling system fluid, were cultured on R2A agar and suspended separately in fresh filter-sterilized ISS cooling fluid, pH 8.3. Initial numbers in each suspension ranged from 10(exp 6)-10(exp 7) CFU/ml, and a mixture contained greater than 10(exp 7) CFU/ml. Coupons of ISS HX material, previously used on orbit (HXOO) or unused (HXUU), polycarbonate (PC) and 316L polished stainless steel (SS) were autoclaved, covered with multispecies suspension in sterile tubes and incubated in the dark at ambient (22-25 C). Original HX material contained greater than 90% Ni, 4.5% Si, and 3.2% B, with a borate buffer. For approximately 10 weeks, samples of fluid were plated on R2A agar, and surface colonization assessed by SYBR green or BacLight staining and microscopy. Suspension counts for the PC and SC samples remained steady at around 10(exp 7) CFU/ml. HXUU counts declined about 1 log in 21 d then remained steady, and HXOO counts declined 2 logs in 28 d, fluctuated and stabilized about 10(exp 3) CFU/ml from 47-54 d. Predominantly yellow S. paucimobilis predominated on plates from HXOO samples up to 26 d, then white or translucent colonies of other species appeared. All colony types were seen on plates from other samples throughout the trial. Epifluorescence microscopy indicated microbial growth on all surfaces by 21 d, followed by variable colonization. After 54 d, all but the HXOO samples had well-distributed live and dead cells; the HXOO samples had few cells and most were live by BacLight. The results suggest that HX materials themselves are inhibiting microbial growth on the surfaces. The HX exposed on orbit to cooling system fluid inhibited growth of some species originally isolated from the system, whereas the unused HX material had a moderate effect compared to no inhibition with PC or SS controls. It is possible that chemistry or microbiology of the ISS system increased deposition of inhibitory compounds on the HXOO coupon surfaces; these may inhibit inoculated species to differing degrees.

  19. Bacterial constituents of indoor air in a high throughput building in the tropics.

    PubMed

    Li, Tee Chin; Ambu, Stephen; Mohandas, Kavitha; Wah, Mak Joon; Sulaiman, Lokman Hakim; Murgaiyah, Malathi

    2014-09-01

    Airborne bacteria are significant biotic constituents of bioaerosol. Bacteria at high concentrations in the air can compromise indoor air quality (IAQ) and result in many diseases. In tropical environments like Malaysia that extensively utilize air-conditioning systems, this is particularly significant due to continuous recirculation of indoor air and the potential implications for human health. Currently, there is a lack of knowledge regarding the impact of airborne bacteria on IAQ in Malaysia. This study was prompted by a need for reliable baseline data on airborne bacteria in the indoor environment of tropical equatorial Malaysia, that may be used as a reference for further investigations on the potential role played by airborne bacteria as an agent of disease in this region. It was further necessitated due to the threat of bioterrorism with the potentiality of release of exotic pathogenic microorganisms into indoor or outdoor air. Before scientists can detect the latter, a gauge of the common microorganisms in indoor (as well as outdoor) air needs to be ascertained, hence the expediency of this study. Bacterial counts from the broad-based and targeted study were generally in the order of 10(2) colony-forming units (CFU) per m(3) of air. The most prevalent airborne bacteria found in the broad-based study that encompassed all five levels of the building were Gram-positive cocci (67.73%), followed by Gram-positive rods (24.26%) and Gram-negative rods (7.10%). Gram-negative cocci were rarely detected (0.71%). Amongst the genera identified, Kytococcus sp., Micrococcus sp., Staphylococcus sp., Leifsonia sp., Bacillus sp. and Corynebacterium sp. predominated in indoor air. The most dominant bacterial species were Kytococcus sedentarius, Staphylococcus epidermidis and Micrococcus luteus. The opportunistic and nosocomial pathogen, Stenotrophomonas maltophilia was also discovered at a high percentage in the cafeteria. The bacteria isolated in this study have been increasingly documented to cause opportunistic infections in immuno-compromised patients, sometimes with fatal outcomes. Furthermore, some of them are becoming increasingly resistant to antibiotics. Hence, we propose that indoor reservoirs of these bacteria and their associated clinical and more subtle health effects, if any, be investigated further. PMID:25382482

  20. Prevalence of Resistant Gram-Negative Bacilli in Bloodstream Infection in Febrile Neutropenia Patients Undergoing Hematopoietic Stem Cell Transplantation: A Single Center Retrospective Cohort Study.

    PubMed

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

    2015-11-01

    Bloodstream infection (BSI) is an important cause of morbidity and mortality in patients undergoing hematopoietic stem cell transplantation (HSCT). To evaluate the causative bacteria and identify risk factors for BSI associated mortality in febrile neutropenia patients undergoing HSCT, we collected the clinical and microbiological data from patients underwent HSCT between 2008 and 2014 and performed a retrospective analysis. Throughout the study period, among 348 episodes of neutropenic fever in patients underwent HSCT, 89 episodes in 85 patients had microbiological defined BSI with a total of 108 isolates. Gram-negative bacteria (GNB) were the most common isolates (76, 70.3%) followed by gram-positive bacteria (GPB, 29, 26.9%) and fungus (3, 2.8%). As to the drug resistance, 26 multiple drug resistance (MDR) isolates were identified. Resistant isolates (n = 23) were more common documented in GNB, mostly Escherichia coli (9/36, 25%) and Klebsiella pneumonia (6/24, 25%). A total of 12 isolated were resistant to carbapenem including 4 K pneumoniae (4/24, 16.7%), 3 Stenotrophomonas maltophilia, and 1 Pseudomonas aeruginosa and other 4 GNB isolates (Citrobacter freumdii, Pseudomonas stutzeri, Acinetobacter baumanii, and Chryseobacterium indologenes). As to the GPB, only 3 resistant isolates were documented including 2 methicillin-resistant isolates (Staphylococcus hominis and Arcanobacterium hemolysis) and 1 vancomycin-resistant Enterococcus faecium. Among these 85 patients with documented BSI, 11 patients died of BSI as primary or associated cause with a BSI-related mortality of 13.1 ± 3.7% and 90-day overall survival after transplantation at 80.0 ± 4.3%. Patients with high-risk disease undergoing allo-HSCT, prolonged neutropenia (≥15 days) and infection with carbapenem-resistant GNB were associated with BSI associated mortality in univariate and multivariate analyses. Our report revealed a prevalence of GNB in BSI of neutropenic patients undergoing HSCT. Patients with high-risk diseases with prolonged neutropenia and carbapenem-resistant GNB were independent risk factors for BSI-related mortality. PMID:26559260

  1. Invitro 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 invitro. 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 3h and 1% bile salt for 24h. 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. PMID:25046742

  2. 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-C16:1?8c, C16:0, anteiso-C16:1?8c, 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 32.70.9, 21.80.3 and 19.90.9%, 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

  3. MIXED-SPECIES COLONIZATION OF SOLID SURFACES IN LABORATORY BIOFILMS

    EPA Science Inventory

    Colonization of glass substrata by populations of three or four bacterial species over periods of four weeks or more was investigated using recirculating, model laboratory systems. umbers of coryneform, Aeromonas hydrophile, Pseudomonas fluoresces, and Xanthomonas maltophilia on ...

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

    PubMed Central

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

    2001-01-01

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

  5. 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 ...

  6. Complete genome sequence of the metabolically versatile halophilic archaeon Haloferax mediterranei, a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) producer.

    PubMed

    Han, Jing; Zhang, Fan; Hou, Jing; Liu, Xiaoqing; Li, Ming; Liu, Hailong; Cai, Lei; Zhang, Bing; Chen, Yaping; Zhou, Jian; Hu, Songnian; Xiang, Hua

    2012-08-01

    Haloferax mediterranei, an extremely halophilic archaeon, has shown promise for production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from unrelated cheap carbon sources. Here we report the complete genome (3,904,707 bp) of H. mediterranei CGMCC 1.2087, consisting of one chromosome and three megaplasmids. PMID:22843593

  7. Complete Genome Sequence of the Extremely Halophilic Archaeon Haloarcula hispanica Strain N601

    PubMed Central

    Ding, Jiun-Yan; Chiang, Pei-Wen; Hong, Mei-Jhu; Dyall-Smith, Mike

    2014-01-01

    Haloarcula hispanica has been widely used in haloarchaeal studies, particularly in the isolation of haloviruses. The genome of strain N601, a laboratory derivative of the type strain ATCC 33960, was sequenced. Several potentially significant differences from the published sequence of the type strain (CGMCC 1.2049 = ATCC 33960) were observed. PMID:24625874

  8. Draft Genome Sequence of Serratia marcescens Strain LCT-SM213

    PubMed Central

    Wang, Yajuan; Yuan, Yanting; Zhou, Lisha; Su, Qingqing; Fang, Xiangqun; Li, Tianzhi; Wang, Junfeng; Chang, De; Su, Longxiang; Xu, Guogang; Guo, Yinghua

    2012-01-01

    Serratia marcescens is a species of Gram-negative, rod-shaped bacterium of the family Enterobacteriaceae. S. marcescens can cause nosocomial infections, particularly catheter-associated bacteremia, urinary tract infections, and wound infections. Here, we present the draft genome sequence of Serratia marcescens strain LCT-SM213, which was isolated from CGMCC 1.1857. PMID:22843602

  9. Amycolatopsis flava sp. nov., a halophilic actinomycete isolated from Dead Sea.

    PubMed

    Wei, Xiaomin; Jiang, Yingying; Chen, Xiu; Jiang, Yi; Lai, Hangxian

    2015-10-01

    A novel halophilic, filamentous actinomycete, designated strain AFM 10111(T), was isolated from a sediment sample collected from the Dead Sea of Israel and its taxonomic position was established by using a polyphasic taxonomic approach. The isolate grew at 20-35 C, pH 5-12 and with 1-30 % NaCl. The substrate mycelium is white or yellow, well developed, branched and fragments into squarish, rod-like elements. The isolate contained meso-diaminopimelic acid as cell-wall diamino acid, and arabinose and galactose as whole-cell sugars. The major menaquinone was MK-9(H4). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine phosphatidylmethylethanolamine and one unidentified phospholipid. Major fatty acids were iso-C16:0, iso-C16:1 H, C17:1 ?6c. The DNA G + C content was 67.7 mol %. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AFM 10111(T) belongs to the genus Amycolatopsis, and formed a distinct clade with Amycolatopsis marina CGMCC 4.3568(T) and Amycolatopsis palatopharyngis CGMCC 4.1729(T), with the sequence similarity 98.4 and 98.6 %. The level of DNA-DNA relatedness between the strain AFM 10111(T) and A. marina CGMCC 4.3568(T) and A. palatopharyngis CGMCC 4.1729(T) were 46.9 3.08 and 49.4 1.25 %. The combined genotypic and phenotypic data indicate that strain AFM 10111(T) represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsis flava sp. nov. is proposed. The type strain is AFM 10111(T) (= DSM 46658(T) = CGMCC 4.7123(T)). PMID:26233655

  10. Microbial transformation of diosgenin by filamentous fungus Cunninghamella echinulata.

    PubMed

    Xiao, Xiao; Liu, Xi-Kui; Fu, Shao-Bin; Sun, Di-An

    2011-03-01

    Microbial transformation of diosgenin (1) by suspended-cell cultures of the filamentous fungus Cunninghamella echinulata CGMCC 3.2000 was investigated. Incubation of the substrate diosgenin (1) with this fungus led to the isolation of three products: two known compounds, (25R)-spirost-5-en-3?,7?,12?-triol and (25R)-spirost-5-en-3?,7?,11?-triol, and a new compound (25R)-spirost-5-en-3?,7?,11?-triol. The structural elucidations of the three compounds were achieved mainly by the MS, 1D and 2D NMR spectroscopic methods and comparison with known compounds. C. echinulata CGMCC 3.2000 has not been used before in the biotransformation of diosgenin. PMID:21409691

  11. Comparison of aroma-active volatiles and their sensory characteristics of mangosteen wines prepared by Saccharomyces cerevisiae with GC-olfactometry and principal component analysis.

    PubMed

    Xiao, Zuo Bing; Liu, Jun Hua; Chen, Feng; Wang, Ling Ying; Niu, Yun Wei; Feng, Tao; Zhu, Jian Cai

    2015-01-01

    Mangosteen fruit is fermented with five different strains (i.e. GRE (Y1), Lalvin RC212 (Y2), Lalvin D254 (Y3), CGMCC2.23 (Y4) and CGMCC2.4 (Y5)) of the yeast Saccharomyces cerevisiae to make mangosteen wines. A total of 36 volatile compounds of the mangosteen wines were identified by gas chromatography-mass spectrometry and gas chromatography-pulsed flame photometric detection. A total of 35 odour-active compounds were identified by gas chromatography-olfactometry analysis and by the detection frequency (DF) method. The compounds with high DF values included ethyl octanoate, ethyl hexanoate and 3-methyl-2-butene-1-thiol. Principal component analysis was used to characterise the differences of the flavour profiles of those mangosteen wines. The result demonstrated that the samples could be divided into three groups that were associated closely with aroma-active compounds. PMID:25428208

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

    PubMed

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

    2015-10-01

    Here we evaluate the immunomodulatory function of two potential probiotic strains, Lactobacillus salivarius CICC 23174 and Lactobacillus plantarum CGMCC 1.557. Mice were fed with each Lactobacillus strain at different doses for several consecutive days. The effects of the two probiotic strains on immune organs, immune cells and immune molecules were investigated on days 10 and 20. Both Lactobacillus strains increased the spleen index, improved the spleen lymphocyte transformation rate, enhanced sIgA production and improved the number of CD11c(+) CD80(+) double-positive cells. L. plantarum CGMCC 1.557 was the more active strain in enhancing the phagocytic activity of macrophages, while, L. salivarius CICC 23174 was the more effective strain at maintaining the Th1/Th2 balance. This study suggests that these two Lactobacillus strains have beneficial effects on regulation of immune responses, which has promising implications for the development of ecological agents and functional foods. PMID:26143437

  13. Microbial Transformation of 14-Anhydrodigoxigenin by Alternaria alternata.

    PubMed

    Liu, Jimei; Tang, Wanxia; Chen, Ridao; Dai, Jungui

    2015-12-01

    The microbial transformation of 14-anhydrodigoxigenin (1) by Alternaria alternata CGMCC 3.577 led to the production of seven new metabolites, 2-8. Their structures were determined by extensive spectroscopic (CD, IR, 1D- and 2D-NMR, and HR-ESI-MS) data analyses. The reactions in the bioprocess exhibited diversity, including specific oxidation, hydroxylation, reduction, epoxidation, and dehydration. In addition, a hypothetical biocatalytic pathway is proposed. PMID:26663840

  14. Complete genome sequence of Bifidobacterium adolesentis BBMN23, a probiotic strain from healthy centenarian.

    PubMed

    Liu, Songling; Zhao, Liang; Ren, Fazheng; Sun, Erna; Zhang, Ming; Guo, Huiyuan

    2015-03-20

    Bifidobacterium adolesentis BBMN23 (CGMCC No. 2264) was a probiotic strain originated from the feces of a centenarian. It is an excellent model for the study of the adaptation of genus bifidobacteria to adult human gut, which is a key factor in bifidobacterial strains that allows them to persist in gut and become useful in the food and medical industries. In the present study the complete genome sequence of BBMN23 is presented to provide insight into this strain. PMID:25678139

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

    PubMed

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

    2010-03-01

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

  16. Characterization of Pseudomonas species isolated from clinical specimens.

    PubMed

    Gilardi, G L

    1971-03-01

    More than 90 morphological and physiological characters of 227 strains of pseudomonads isolated from clinical specimens and 16 reference strains are described. The clinical isolates included P. aeruginosa (apyocyanogenic), P. fluorescens, P. putida, P. pseudomallei, P. cepacia, P. acidovorans, P. alcaligenes, P. pseudoalcaligenes, P. stutzeri, P. putrefaciens, P. maltophilia, and P. diminuta. PMID:4928600

  17. Haloarchaeobius salinus sp. nov., isolated from an inland salt lake, and emended description of the genus Haloarchaeobius.

    PubMed

    Yuan, Pan-Pan; Zhang, Wen-Jiao; Han, Dong; Cui, Heng-Lin

    2015-03-01

    The halophilic archaeal strain, YC82(T), was isolated from Yuncheng salt lake in Shanxi, PR China. Cells from strain YC82(T) were Gram-stain negative, pleomorphic rods, which lysed in distilled water and formed light-red colonies on solid media. Strain YC82(T) grew at 25-50 C (optimum 37 C), in 1.4-4.8 M NaCl (optimum 2.0 M), in 0-1.0 M MgCl2 (optimum 0.05 M) and at pH 6.0-9.5 (optimum pH 7.5). The major polar lipids of strain YC82(T) were phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and three glycolipids, which were chromatographically identical to those of Haloarchaeobius iranensis IBRC-M 10013(T) and Haloarchaeobius litoreus CGMCC 1.10390(T). 16S rRNA gene analysis revealed that strain YC82(T) had two dissimilar 16S rRNA genes and that it was phylogenetically related to Hab. iranensis IBRC-M 10013(T) (94.3-99.0?% nucleotide identity) and Hab. litoreus CGMCC 1.10390(T) (94.1-98.8?% nucleotide identity). The rpoB' gene similarities between strain YC82(T) and Hab. iranensis IBRC-M 10013(T) and Hab. litoreus CGMCC 1.10390(T) were 96.5?% and 95.7?%, respectively. The DNA G+C content of strain YC82(T) was 63.7 mol%. Strain YC82(T) showed low DNA-DNA relatedness with Hab. iranensis IBRC-M 10013(T) and Hab. litoreus CGMCC 1.10390(T). The phenotypic, chemotaxonomic and phylogenetic properties of strain YC82(T) (?=?CGMCC 1.12232(T)?=?JCM 18644(T)) suggest that it represents a novel species of the genus Haloarchaeobius, for which the name Haloarchaeobius salinus sp. nov. is proposed. An emended description of the genus Haloarchaeobius is also presented. PMID:25563910

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

    PubMed Central

    Cernava, Tomislav; Mller, 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

  19. Halovenus rubra sp. nov., isolated from salted brown alga Laminaria.

    PubMed

    Han, Dong; Zhang, Wen-Jiao; Cui, Heng-Lin; Li, Zheng-Rong

    2015-01-01

    Halophilic archaeal strain R28(T) was isolated from the brown alga Laminaria produced at Dalian, Liaoning Province, China. The cells of the strain were pleomorphic and lysed in distilled water, stained Gram-negative, and formed red-pigmented colonies. Strain R28(T) was able to grow at 25-50 C (optimum 42 C), in the presence of 3.1-5.1 M NaCl (optimum 3.9 M NaCl), with 0.005-1.0 M MgCl(2) (optimum 0.01 M MgCl(2)) and at pH 6.0-9.5 (optimum pH 7.0-7.5). The minimal NaCl concentration to prevent cell lysis was 15 % (w/v). The major polar lipids of the strain were identified as phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, and two glycolipids chromatographically identical to those of Halovenus aranensis CGMCC 1.11001(T). The 16S rRNA gene and rpoB' gene of strain R28(T) were phylogenetically related to the corresponding genes of Hvn. aranensis CGMCC 1.11001(T) (91.9-97.2 and 82.9 % nucleotide identity, respectively). The DNA G+C content of strain R28(T) was determined to be 56.3 mol%. The phenotypic, chemotaxonomic, and phylogenetic properties suggest that strain R28(T) (=CGMCC 1.10592(T) = JCM 17269(T)) represents a novel species of the genus Halovenus, for which the name Halovenus rubra sp. nov. is proposed. PMID:25199562

  20. Genetic and biochemical characterization of the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) synthase in Haloferax mediterranei.

    PubMed

    Lu, Qiuhe; Han, Jing; Zhou, Ligang; Zhou, Jian; Xiang, Hua

    2008-06-01

    The haloarchaeon Haloferax mediterranei has shown promise for the economical production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a desirable bioplastic. However, little is known at present about the genes involved in PHBV synthesis in the domain Archaea. In this study, we cloned the gene cluster (phaEC(Hme)) encoding a polyhydroxyalkanoate (PHA) synthase in H. mediterranei CGMCC 1.2087 via thermal asymmetric interlaced PCR. Western blotting revealed that the phaE(Hme) and phaC(Hme) genes were constitutively expressed, and both the PhaE(Hme) and PhaC(Hme) proteins were strongly bound to the PHBV granules. Interestingly, CGMCC 1.2087 could synthesize PHBV in either nutrient-limited medium (supplemented with 1% starch) or nutrient-rich medium, up to 24 or 18% (wt/wt) in shaking flasks. Knockout of the phaEC(Hme) genes in CGMCC 1.2087 led to a complete loss of PHBV synthesis, and only complementation with the phaEC(Hme) genes together (but not either one alone) could restore to this mutant the capability for PHBV accumulation. The known haloarchaeal PhaC subunits are much longer at their C termini than their bacterial counterparts, and the C-terminal extension of PhaC(Hme) was proven to be indispensable for its function in vivo. Moreover, the mixture of purified PhaE(Hme)/PhaC(Hme) (1:1) showed significant activity of PHA synthase in vitro. Taken together, our results indicated that a novel member of the class III PHA synthases, composed of PhaC(Hme) and PhaE(Hme), accounted for the PHBV synthesis in H. mediterranei. PMID:18408025

  1. 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

  2. Complete genome sequence of Bifidobacterium animalis subsp. lactis A6, a probiotic strain with high acid resistance ability.

    PubMed

    Sun, Erna; Zhao, Liang; Ren, Fazheng; Liu, Songling; Zhang, Ming; Guo, Huiyuan

    2015-04-20

    Bifidobacterium animalis subsp. lactis A6 (BAA6) (CGMCC No. 9273) was a probiotic strain isolated from the feces of a centenarian. Previous study showed that BAA6 had high acid resistance to low pH which is a critical factor influencing its healthy benefits. Elaborating the stress resistant mechanisms of bifidobacteria is important to extensively exploit this probiotic. Here, we reported the complete genome sequence of BAA6 that contains 1,958,651 bp encoding 1622 CDSs, 16 rRNA genes, 52 tRNA genes. PMID:25707999

  3. 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

  4. Optimization of culture medium compositions for gellan gum production by a halobacterium Sphingomonas paucimobilis.

    PubMed

    Zhang, Jun; Dong, Ya-chen; Fan, Lin-lin; Jiao, Zhi-hua; Chen, Qi-he

    2015-01-22

    The effect of culture medium compositions on gellan gum production produced by fermentation with a halobacterium Sphingomonas paucimobilis QHZJUJW CGMCC2428 was studied. In this work, a fractional factorial design was applied to investigate the main factors that affected gellan gum production by S. paucimobilis QHZJUJW CGMCC2428. Sucrose was the best carbon source for gellan gum and peptone displayed better inducing effect. Central composite design and response surface methodology were adopted to derive a statistical model for optimizing submerged culture medium composition. These experimental results showed that the optimum culture medium for producing gellan gum was composed of 40.00 (w/v) sucrose, 3.00% peptone (w/v), MgSO4 (w/v), 9.20% KH2PO4 (w/v), 7.50% Na2HPO4 (w/v), 4.30% K2SO4 (w/v), pH 6.8-7.0. The maximal gellan gum was 19.89±0.68 g/L, which was agreed closely with the predicated value (20.12 g/L). After incubated for 72 h under the optimized culture medium in 5-L bioreactor, the gellan gum fermentation reached about 19.90±0.68 g/L, which was higher than that in the initial cultivation medium. PMID:25439950

  5. Mutation-Screening of Pleurotus Ferulae with High Temperature Tolerance by Nitrogen Ion Implantation

    NASA Astrophysics Data System (ADS)

    Chen, Henglei; Wan, Honggui; Zhang, Jun; Zeng, Xianxian

    2008-08-01

    In order to obtain Pleurotus ferulae with high temperature tolerance, conidiophores of wild type strain ACK were implanted with nitrogen ions in energy of 5 ~15 keV and dose of 1.5 1015 ~ 1.5 1016 cm-2, and a mutant CGMCC1763 was isolated subsequently through thermotolerant screening method. It was found that during riper period the surface layer mycelium of the mutant in mushroom bag wasn't aging neither grew tegument even above 30 C. The mycelium endurable temperature of the mutant was increased by 5C compared to that of the wild type strain. The fruiting bodies growth temperature of the mutant was 18 ~22C in daytime and 8~14C at night. The highest growth temperature of fruiting bodies of the mutant was increased about 7C w.r.t. that of original strain. Through three generations investigations, it was found that the mutant CGMCC1763 was stable with high temperature tolerance.

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2012-01-01

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

  8. 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

  9. Bradyrhizobium erythrophlei sp. nov. and Bradyrhizobium ferriligni sp. nov., isolated from effective nodules of Erythrophleum fordii.

    PubMed

    Yao, Yao; Sui, Xin Hua; Zhang, Xiao Xia; Wang, En Tao; Chen, Wen Xn

    2015-06-01

    Six slow-growing rhizobial strains isolated from effective nodules of Erythrophleum fordii were classified into the genus Bradyrhizobiumbased on their 16S rRNA gene sequences. The results of multilocus sequence analysis of recA, glnII and gyrB genes and 16S-23S rRNA intergenic spacer (IGS) sequence phylogeny indicated that the six strains belonged to two novel species, represented by CCBAU 53325T and CCBAU 51502T, which were consistent with the results of DNA-DNA hybridization; CCBAU 53325T had 17.65-25.59 % relatedness and CCBAU 51502T had 22.69-44.58 % relatedness with five closely related type strains, Bradyrhizobium elkanii USDA 76T, B. pachyrhizi LMG 24246T, B. lablabi CCBAU 23086T, B. jicamae LMG 24556T and B. japonicum USDA 6T. In addition, analysis of phenotypic characteristics and fatty acid profiles also distinguished the test strains from defined species of Bradyrhizobium. Two novel species, Bradyrhizobium erythrophlei sp. nov., represented by the type strain CCBAU 53325T (?= HAMBI 3614T = CGMCC 1.13002T = LMG 28425T), and Bradyrhizobium ferriligni sp. nov., represented by the type strain CCBAU 51502T (?= HAMBI 3613T = CGMCC 1.13001T), are proposed to accommodate the strains. PMID:25754551

  10. 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

  11. 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.

  12. Global insights into acetic acid resistance mechanisms and genetic stability of Acetobacter pasteurianus strains by comparative genomics.

    PubMed

    Wang, Bin; Shao, Yanchun; Chen, Tao; Chen, Wanping; Chen, Fusheng

    2015-01-01

    Acetobacter pasteurianus (Ap) CICC 20001 and CGMCC 1.41 are two acetic acid bacteria strains that, because of their strong abilities to produce and tolerate high concentrations of acetic acid, have been widely used to brew vinegar in China. To globally understand the fermentation characteristics, acid-tolerant mechanisms and genetic stabilities, their genomes were sequenced. Genomic comparisons with 9 other sequenced Ap strains revealed that their chromosomes were evolutionarily conserved, whereas the plasmids were unique compared with other Ap strains. Analysis of the acid-tolerant metabolic pathway at the genomic level indicated that the metabolism of some amino acids and the known mechanisms of acetic acid tolerance, might collaboratively contribute to acetic acid resistance in Ap strains. The balance of instability factors and stability factors in the genomes of Ap CICC 20001 and CGMCC 1.41 strains might be the basis for their genetic stability, consistent with their stable industrial performances. These observations provide important insights into the acid resistance mechanism and the genetic stability of Ap strains and lay a foundation for future genetic manipulation and engineering of these two strains. PMID:26691589

  13. Agrococcus terreus sp. nov. and Micrococcus terreus sp. nov., isolated from forest soil.

    PubMed

    Zhang, Jia-Yue; Liu, Xing-Yu; Liu, Shuang-Jiang

    2010-08-01

    Two bacterial strains, DNG5T and V3M1T, isolated from forest soil of the Changbai mountains in China, were characterized using a polyphasic approach. Analysis of their 16S rRNA gene sequences indicated that strains DNG5T and V3M1T were phylogenetically related to members of the genus Agrococcus (96.0-98.4% similarity) and Micrococcus (96.7-98.0% similarity), respectively, within the order Actinomycetales. Strains DNG5T and V3M1T were Gram-stain-positive and strictly aerobic and formed yellow colonies on LB agar. Cells of strain DNG5T were short, non-motile rods, 0.4-0.5x0.8-1.0 microm. Strain DNG5T contained MK-10 and MK-11 as the major respiratory quinones and anteiso-C15:0 (49.2%) and iso-C16:0 (22.4%) as the major fatty acids. The diamino acid in the peptidoglycan of strain DNG5T was 2,4-diaminobutyric acid and the murein was of the acetyl type. Cells of strain V3M1T were cocci, 0.6-0.7 microm in diameter. The cell-wall peptidoglycan of strain V3M1T contained the amino acids lysine, glutamic acid, alanine and glycine. Strain V3M1T contained MK-7, MK-7(H2), MK-8 and MK-8(H2) as respiratory quinones and anteiso-C15:0 (78.2%) and iso-C15:0 (13.1%) as the major cellular fatty acids. The DNA G+C contents of strains DNG5T and V3M1T were 75.9 and 67.2 mol%, respectively. The DNA-DNA relatedness of strain DNG5T to Agrococcus jejuensis DSM 22002T, A. jenensis JCM 9950T, A. baldri JCM 12132T and A. citreus JCM 12398T was 58.3, 43.9, 36.1 and 54.1%, respectively. The DNA-DNA relatedness of strain V3M1T to Micrococcus luteus CGMCC 1.2299T, M. antarcticus CGMCC 1.2373T and M. lylae CGMCC 1.2300T was 57.5, 45.4 and 39.0%, respectively. Combining phenotypic and genotypic traits, strain DNG5T represents a novel species of the genus Agrococcus, for which the name Agrococcus terreus sp. nov. is proposed, with DNG5T (=CGMCC 1.6960T =NBRC 104260T) as the type strain. Strain V3M1T represents a novel species of the genus Micrococcus, for which the name Micrococcus terreus sp. nov. is proposed, with V3M1T (=CGMCC 1.7054T =NBRC 104258T) as the type strain. PMID:19783614

  14. Variation of nonylphenol-degrading gene abundance and bacterial community structure in bioaugmented sediment microcosm.

    PubMed

    Wang, Zhao; Yang, Yuyin; Sun, Weimin; Dai, Yu; Xie, Shuguang

    2015-02-01

    Nonylphenol (NP) can accumulate in river sediment. Bioaugmentation is an attractive option to dissipate heavy NP pollution in river sediment. In this study, two NP degraders were isolated from crude oil-polluted soil and river sediment. Microcosms were constructed to test their ability to degrade NP in river sediment. The shift in the proportion of NP-degrading genes and bacterial community structure in sediment microcosms were characterized using quantitative PCR assay and terminal restriction fragment length polymorphism analysis, respectively. Phylogenetic analysis indicated that the soil isolate belonged to genus Stenotrophomonas, while the sediment isolate was a Sphingobium species. Both of them could almost completely clean up a high level of NP in river sediment (150 mg/kg NP) in 10 or 14 days after inoculation. An increase in the proportion of alkB and sMO genes was observed in sediment microcosms inoculated with Stenotrophomonas strain Y1 and Sphingobium strain Y2, respectively. Moreover, bioaugmentation using Sphingobium strain Y2 could have a strong impact on sediment bacterial community structure, while inoculation of Stenotrophomonas strain Y1 illustrated a weak impact. This study can provide some new insights towards NP biodegradation and bioremediation. PMID:25277711

  15. Streptosporangium lutulentum sp. nov., Streptosporangium fenghuangense sp. nov. and Streptosporangium corydalis sp. nov., three novel actinobacterial species isolated from National Forest Park of Fenghuang Mountain.

    PubMed

    Fang, Baozhu; Liu, Hui; Pan, Tong; Liu, Chongxi; Guan, Xuejiao; He, Hairong; Yan, Kai; Li, Jiansong; Xiang, Wensheng; Wang, Xiangjing

    2016-03-01

    Three novel actinobacteria, designated strains NEAU-FSHN1(T), NEAU-hd-3(T) and NEAU-Y6(T), were isolated from a stream base, soil adjacent to the stream and a root of Corydalis yanhusuo L, respectively, collected from Wuchang, Heilongjiang Province, China. A polyphasic study was carried out to establish the taxonomic positions of these strains. The three strains were observed to form scant aerial hyphae that differentiated into spherical spore vesicles. The phylogenetic analysis based on the 16S rRNA gene sequences of strains NEAU-FHSN1(T), NEAU-hd-3(T) and NEAU-Y6(T) showed that the three novel isolates exhibit 99.2% (NEAU-FHSN1(T)/NEAU-hd-3(T)), 99.2% (NEAU-FHSN1(T)/NEAU-Y6(T)) and 99.7% (NEAU-hd-3(T)/NEAU-Y6(T)) 16S rRNA gene sequence similarities with each other and that they are closely related to strains Streptosporangium shengliense NEAU-GH7(T) (sequence similarities 98.72, 98.85, 98.99%), Streptosporangium roseum DSM 43021(T) (98.65, 98.51, 98.58%) and Streptosporangium album DSM 43023(T) (98.41, 98.96, 98.89%). However, the DNA-DNA hybridization values between strains NEAU-FSHN1(T), NEAU-hd-3(T) and NEAU-Y6(T) were 61.2% (NEAU-FSHN1(T)/NEAU-hd-3(T)), 63.5% (NEAU-FHSN1(T)/NEAU-Y6(T)) and 65.8% (NEAU-hd-3(T)/NEAU-Y6(T)), and the values between the three strains and their close phylogenetic relatives were also below 70%. With reference to phenotypic characteristics, phylogenetic data and DNA-DNA hybridization results, the three strains can be distinguished from each other and their close phylogenetic relatives. Thus, strains NEAU-FHSN1(T), NEAU-hd-3(T) and NEAU-Y6(T) are concluded to represent three novel species of the genus Streptosporangium, for which the names Streptosporangium lutulentum sp. nov., Streptosporangium fenghuangense sp. nov. and Streptosporangium corydalis sp. nov. are proposed. The type strains are NEAU-FHSN1(T) (=CGMCC 4.7141(T)=DSM 46740(T)), NEAU-Y6(T) (=CGMCC 4.7150(T)=DSM 46722(T)) and NEAU-hd3(T) (CGMCC 4.7212(T)=JCM 30058(T)), respectively. PMID:26767659

  16. Evaluation of the formation of volatiles and sensory characteristics of persimmon (Diospyros kaki L.f.) fruit wines using different commercial yeast strains of Saccharomyces cerevisiae.

    PubMed

    Zhu, Jian Cai; Niu, Yun Wei; Feng, Tao; Liu, Sheng Jiang; Cheng, He Xing; Xu, Na; Yu, Hai Yan; Xiao, Zuo Bing

    2014-01-01

    This study evaluated the effects of five strains (IFFI 1346, IFFI 1363, CICC 31482, D254 and CGMCC2.346) of the yeast Saccharomyces cerevisiae on the aromatic profiles of fermented persimmon (Diospyros kaki L.f.) musts. A total of 50 and 60 compounds were identified in persimmon wine by stir bar sorptive extraction coupled with gas chromatography-mass spectrometry. According to odour activity values (OAVs), 26 detected compounds showed an OAV above 1. Principal component analysis explained the distribution of these persimmon wines on the basis of volatile compounds with OAV>1. The volatile compounds with high OAV included ethyl hexanoate, ethyl octanoate, methyl decanoate, linalool and geraniol. Quantitative descriptive analysis was employed. The result showed that persimmon wines fermented with strains IFFI 1363 and D254 were strongly correlated with persimmon, aroma harmony, fruity, fusel and taste balanced, fullness, hedonic scale. Therefore, the two yeast strains could be used as starter culture for persimmon wine production. PMID:25186058

  17. Complete genome sequence of Lactobacillus salivarius Ren, a probiotic strain with anti-tumor activity.

    PubMed

    Sun, Erna; Ren, Fazheng; Liu, Songling; Ge, Shaoyang; Zhang, Ming; Guo, Huiyuan; Jiang, Lu; Zhang, Hao; Zhao, Liang

    2015-09-20

    Lactobacillus salivarius Ren (LsR) (CGMCC No. 3606) is a probiotic strain that was isolated from the feces of a healthy centenarian living in Bama, Guangxi, China. Previous studies have shown that this strain decreases 4-nitroquinoline 1-oxide (4-NQO)-induced genotoxicity in vitro. It also suppresses 4-NQO-induced oral carcinogenesis and 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis, and therefore may be used as an adjuvant therapeutic agent for cancer. Here, we report the complete genome sequence of LsR that consists of a circular chromosome of 1751,565 bp and two plasmids (pR1, 176,951 bp; pR2, 49,848 bp). PMID:26133929

  18. Molecular Phylogenetic Analysis of Ballistoconidium-Forming Yeasts in Trichosporonales (Tremellomycetes): A Proposal for Takashimella gen. nov. and Cryptotrichosporon tibetense sp. nov.

    PubMed Central

    Wang, Long; Wang, Qi-Ming

    2015-01-01

    Bullera species in the Trichosporonales (Tremellomycetes, Agaricomycotina) are phylogenetically distinct from Bullera alba (teleomorph: Bulleromyces albus), the type species of Bullera that belongs to Tremellales. In the present study, the three Bullera species, namely Bullera formosensis, Bullera koratensis and Bullera lagerstroemiae, and Cryptococcus tepidarius belonging to the Trichosporonales are transferred into a new genus Takashimella gen. nov. (MycoBank No. MB 810672) based on sequence analysis of the small subunit (SSU) rRNA gene, the D1/D2 domains of large subunit (LSU) rRNA gene and the ITS+5.8S rRNA gene sequences. In addition, the genus Cryptotrichosporon is emended to accommodate a novel ballistoconidium-forming species of the Trichosporonales, which is named as Cryptotrichosporon tibetense (type strain CGMCC 2.02614T = CBS 10455T). The MycoBank number of this new species is MB 810688. PMID:26200459

  19. Pantoea pleuroti sp. nov., Isolated from the Fruiting Bodies of Pleurotus eryngii.

    PubMed

    Ma, Yuanwei; Yin, Yonggang; Rong, Chengbo; Chen, Sanfeng; Liu, Yu; Wang, Shouxian; Xu, Feng

    2016-02-01

    Four Gram-negative-staining, facultatively anaerobic bacterial isolates were obtained from the fruiting bodies of the edible mushroom Pleurotus eryngii showing symptoms of bacterial blight disease in Beijing, China. Nearly complete 16S rRNA gene sequencing placed these isolates in the genus Pantoea. Multilocus sequence analysis based on the partial sequences of atpD, gyrB, infB and rpoB revealed Pantoea agglomerans as their closest phylogenetic relatives. DNA-DNA hybridization and phenotypic tests confirmed the classification of the new isolates as a novel species. The name Pantoea pleuroti sp. nov. [type strain KCTC 42084(T) = CGMCC 1.12894(T) = JZB 2120015(T)] is proposed. PMID:26581526

  20. Fabivirga thermotolerans gen. nov., sp. nov., a novel marine bacterium isolated from culture broth of a marine cyanobacterium.

    PubMed

    Tang, M; Chen, C; Li, J; Xiang, W; Wu, H; Wu, J; Dai, S; Wu, H; Li, T; Wang, G

    2016-02-01

    A Gram-stain-negative, red, non-spore-forming, strictly aerobic bacterium, designated strain A4T, was isolated from culture broth of a marine cyanobacterium. Cells were flexible rods with gliding motility. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain A4T formed a coherent cluster with members of the genera Roseivirga and Fabibacter, and represents a distinct lineage in the family Flammeovirgaceae. Thermotolerance and a distinctive cellular fatty acid profile could readily distinguish this isolate from any bacteria of the genera Roseivirga and Fabibacter with a validly published name. On the basis of the phenotypic, chemotaxonomic and phylogenetic characteristics, strain A4T is suggested to represent a novel species in a novel genus, for which the name Fabivirga thermotolerans gen. nov., sp. nov. is proposed. The type strain is A4T ( = KCTC 42507T = CGMCC 1.15111T). PMID:26652750

  1. Reclassification of Saccharomycodes sinensis, Proposal of Yueomyces sinensis gen. nov., comb. nov. within Saccharomycetaceae (Saccharomycetales, Saccharomycotina)

    PubMed Central

    Wang, Long; Groenewald, Marizeth; Wang, Qi-Ming; Boekhout, Teun

    2015-01-01

    The phylogenetic position of Saccharomycodes sinensis has been debated by yeast taxonomists. In this study, a multigene phylogenetic analysis based on four regions, namely the 18S ribosomal DNA (rDNA), the D1/D2 domains of the 26S rDNA, the second largest subunit of RNA polymerase II gene (RPB2) and translation elongation factor 1-α gene (EF1-α), were performed to address the phylogenetic placement of S. sinensis. Our result indicated that S. sinensis belongs to Saccharomycetaceae instead of Saccharomycodaceae, and forms a single species lineage divergent from the other genera within Saccharomycetaceae. Yueomyces gen. nov. (MycoBank No. MB 811648) is proposed in the Saccharomycetaceae with Y. sinensis comb. nov. (MycoBank No. MB 811649, type strain CGMCC 2.01395T = IFO 10111T = CBS 7075T) as the type species. PMID:26375944

  2. 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

  3. 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.

  4. 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

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

    PubMed

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

    2015-05-01

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

  6. Sphingomonas qilianensis sp. nov., Isolated from Surface Soil in the Permafrost Region of Qilian Mountains, China.

    PubMed

    Piao, Ai-Lian; Feng, Xiao-Min; Nogi, Yuichi; Han, Lu; Li, Yonghong; Lv, Jie

    2016-04-01

    A Gram-stain-negative, strictly aerobic, non-motile and rod-shaped bacterial strain, designated X1(T), was isolated from the permafrost region of Qilian Mountains in northwest of China. Phylogenetic analyses of 16S rRNA gene sequence revealed that strain X1(T) was a member of the genus Sphingomonas and shared the highest 16S rRNA gene sequence similarity with Sphingomonas oligophenolica JCM 12082(T) (96.9 %), followed by Sphingomonas glacialis CGMCC 1.8957(T) (96.7 %) and Sphingomonas alpina DSM 22537(T) (96.4 %). Strain X1(T) was able to grow at 15-30 °C, pH 6.0-10.0 and with 0-0.3 % NaCl (w/v). The DNA G+C content of the isolate was 64.8 mol%. Strain X1(T)-contained Q-10 as the dominant ubiquinone and C18:1 ω7c, C16:1 ω7c, C16:0 and C14:0 2-OH as the dominant fatty acids. The polar lipid profile of strain XI(T)-contained sphingoglycolipid, phosphatidylglycerol, phosphatidylethanolamine, one unidentified glycolipid and two unidentified phospholipid. Due to the phenotypic and genetic distinctiveness and other characteristic studied in this article, we consider X1(T) as a novel species of the genus Sphingomonas and propose to name it Sphingomonas qilianensis sp. nov. The type strain is X1(T) (=CGMCC 1.15349(T) = KCTC 42862(T)). PMID:26676296

  7. Two new species of the genus Micromonospora: Micromonospora palomenae sp. nov. and Micromonospora harpali sp. nov. isolated from the insects.

    PubMed

    Fang, Baozhu; Liu, Chongxi; Guan, Xuejiao; Song, Jia; Zhao, Junwei; Liu, Hui; Li, Chuang; Ning, Wenxi; Wang, Xiangjing; Xiang, Wensheng

    2015-07-01

    Two novel actinobacteria, strains NEAU-CX1(T) and NEAU-JC6(T), were isolated from nymphs of stinkbug (Palomena viridissima Poda) and a beetle (Harpalus sinicus Hope), respectively, collected from Harbin, Heilongjiang Province, China. A polyphasic study was carried out to establish the taxonomic positions of these strains. The phylogenetic analysis based on 16S rRNA gene sequence of strain NEAU-CX1(T) showed it to be most closely related to Micromonospora coxensis JCM 13248(T) (99.3 % sequence similarity), Micromonospora purpureochromogenes DSM 43821(T) (99.1 %) and Micromonospora halophytica JCM 3125(T) (98.6 %), and that of strain NEAU-JC6(T) to Micromonospora haikouensis DSM 45626(T) (99.3 %), Micromonospora carbonacea JCM 3139(T) (99.1 %) and Micromonospora krabiensis JCM 12869(T) (99.1 %). The phylogenetic analysis based on gyrB gene sequence of strain NEAU-CX1(T) showed it to be most closely related to M. purpureochromogenes DSM 43821(T) (98.0 % sequence similarity), and that of strain NEAU-JC6(T) to M. haikouensis DSM 45626(T) (99.0 %) and M. carbonacea JCM 3139(T) (98.0 %). A combination of DNA-DNA hybridization results and cultural and physiological properties indicated that the two strains can be distinguished from their closest phylogenetic relatives. Thus, strains NEAU-CX1(T) and NEAU-JC6(T) represent two novel species of the genus Micromonospora, for which the names Micromonospora palomenae sp. nov. and Micromonospora harpali sp. nov. are proposed. The type strains are NEAU-CX1(T) (=CGMCC 4.7175(T) = JCM 30056(T)) and NEAU-JC6(T) (=CGMCC 4.7173(T) = JCM 30055(T)). PMID:25957972

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

    PubMed

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

    2013-01-01

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

  9. Proteomic profiling of Bacillus licheniformis reveals a stress response mechanism in the synthesis of extracellular polymeric flocculants.

    PubMed

    Yu, Wencheng; Chen, Zhen; Shen, Liang; Wang, Yuanpeng; Li, Qingbiao; Yan, Shan; Zhong, Chuan-Jian; He, Ning

    2016-04-01

    Some bioflocculants composed of extracellular polymeric substances are produced under peculiar conditions. Bacillus licheniformis CGMCC2876 is a microorganism that secretes both extracellular polysaccharides (EPS) and poly-gamma-glutamic acid (γ-PGA) under stress conditions. In this work, SWATH acquisition LC-MS/MS method was adopted for differential proteomic analysis of B. licheniformis, aiming at determining the bacterial stress mechanism. Compared with LB culture, 190 differentially expressed proteins were identified in B. licheniformis CGMCC2876 cultivated in EPS culture, including 117 up-regulated and 73 down-regulated proteins. In γ-PGA culture, 151 differentially expressed proteins, 89 up-regulated and 62 down-regulated, were found in the cells. Up-regulated proteins involved in amino acid biosynthesis were found to account for 43% and 41% of the proteomes in EPS and γ-PGA cultivated cells, respectively. Additionally, a series of proteins associated with amino acid degradation were found to be repressed under EPS and γ-PGA culture conditions. Transcriptional profiling via the qPCR detection of selected genes verified the proteomic analysis. Analysis of free amino acids in the bacterial cells further suggested the presence of amino acid starvation conditions. EPS or γ-PGA was synthesized to alleviate the effect of amino acid limitation in B. licheniformis. This study identified a stress response mechanism in the synthesis of macromolecules in B. licheniformis, providing potential culture strategies to improve the production of two promising bioflocculants. Biotechnol. Bioeng. 2016;113: 797-806. © 2015 Wiley Periodicals, Inc. PMID:26388297

  10. 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

  11. Antibiotic-Resistant Gram-Negative Bacterial Infections in Patients With Cancer

    PubMed Central

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

    2014-01-01

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

  12. Characterization of copper-resistant bacteria and bacterial communities from copper-polluted agricultural soils of central Chile

    PubMed Central

    2012-01-01

    Background Copper mining has led to Cu pollution in agricultural soils. In this report, the effects of Cu pollution on bacterial communities of agricultural soils from Valparaiso region, central Chile, were studied. Denaturing gradient gel electrophoresis (DGGE) of the 16S rRNA genes was used for the characterization of bacterial communities from Cu-polluted and non-polluted soils. Cu-resistant bacterial strains were isolated from Cu-polluted soils and characterized. Results DGGE showed a similar high number of bands and banding pattern of the bacterial communities from Cu-polluted and non-polluted soils. The presence of copA genes encoding the multi-copper oxidase that confers Cu-resistance in bacteria was detected by PCR in metagenomic DNA from the three Cu-polluted soils, but not in the non-polluted soil. The number of Cu-tolerant heterotrophic cultivable bacteria was significantly higher in Cu-polluted soils than in the non-polluted soil. Ninety two Cu-resistant bacterial strains were isolated from three Cu-polluted agricultural soils. Five isolated strains showed high resistance to copper (MIC ranged from 3.1 to 4.7 mM) and also resistance to other heavy metals. 16S rRNA gene sequence analyses indicate that these isolates belong to the genera Sphingomonas, Stenotrophomonas and Arthrobacter. The Sphingomonas sp. strains O12, A32 and A55 and Stenotrophomonas sp. C21 possess plasmids containing the Cu-resistance copA genes. Arthrobacter sp. O4 possesses the copA gene, but plasmids were not detected in this strain. The amino acid sequences of CopA from Sphingomonas isolates (O12, A32 and A55), Stenotrophomonas strain (C21) and Arthrobacter strain (O4) are closely related to CopA from Sphingomonas, Stenotrophomonas and Arthrobacter strains, respectively. Conclusions This study suggests that bacterial communities of agricultural soils from central Chile exposed to long-term Cu-pollution have been adapted by acquiring Cu genetic determinants. Five bacterial isolates showed high copper resistance and additional resistance to other heavy metals. Detection of copA gene in plasmids of four Cu-resistant isolates indicates that mobile genetic elements are involved in the spreading of Cu genetic determinants in polluted environments. PMID:22950448

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

    PubMed Central

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

    1990-01-01

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

  14. Chemical transformation of toxic metals by a Pseudomonas strain from a toxic waste site

    SciTech Connect

    Blake, R.C. II; Choate, D.M.; Bardhan, S. . Dept. of Biochemistry); Revis, N. ); Barton, L.L. . Dept. of Biology); Zocco, T.G. . Materials Science and Technology Division)

    1993-08-01

    Pseudomonas maltophilia strain O-2, isolated from soil at a toxic waste site in Oak Ridge, Tennessee, catalyzed the transformation and precipitation of numerous toxic metal cations and oxyanions. When a viable inoculum (1%) of O-2 was introduced into nutrient broth containing Hg(II), Cr(VI), Se(IV), Pb(II), Au(III), Cd(II), Te(IV), or Ag(I), effective removal of the toxic metal was complete within 1, 1, 2, 2, 2, 4, 5, and 7 d, respectively. The NADPH-dependent reductions of Hg(II) to Hg[sup 0] 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(II) or bis(glutathio)Te(II), respectively, as pseudosubstrates. The three-electron reduction of hexavalent chromium was catalyzed by a membrane-bound chromate reductase. The enzymatic basis for the remaining metal transformations was not immediately apparent. It is anticipated that Pseudomonas maltophilia and related organisms could eventually be exploited for the removal of toxic metal wastes from selected, heavily polluted sites.

  15. 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.

  16. Controlled clinical evaluation of Isolator and ESP aerobic blood culture systems for detection of bloodstream infections.

    PubMed Central

    Kirkley, B A; Easley, K A; Washington, J A

    1994-01-01

    A controlled clinical evaluation comparing the Isolator system (Wampole Laboratories, Cranbury, N.J.) and the ESP 80A blood culture bottle in the automated ESP system (Difco Laboratories, Detroit, Mich.) was performed with 10,535 blood culture sets from patients with suspected septicemia. Of 1,150 positive cultures, 844 positive cultures from 285 patients with 394 septic episodes fulfilled the study criteria for minimum blood sample requirements in each system and clinical significance of isolates. The Isolator system detected statistically significantly more positive cultures of Staphylococcus aureus (P < 0.001), Enterococcus spp. (P = 0.007), Escherichia coli (P = 0.001), Alcaligenes xylosoxidans (P = 0.02), Xanthomonas maltophilia (P = 0.01), Candida albicans (P < 0.001), and Candida glabrata (P = 0.05). The Isolator system detected significantly more septic episodes due to S. aureus (P < 0.001), X. maltophilia (P = 0.02), and C. albicans (P = 0.004) than did the ESP 80A bottle; however, the two systems did not otherwise significantly differ in their abilities to detect septic episodes due to other organisms. PMID:8077401

  17. Nonylphenol biodegradation, functional gene abundance and bacterial community in bioaugmented sediment: effect of external carbon source.

    PubMed

    Wang, Zhao; Dai, Yu; Zhao, Qun; Li, Ningning; Zhou, Qiheng; Xie, Shuguang

    2015-08-01

    Nonylphenol (NP) biodegradation in river sediment using Stenotrophomonas strain Y1 and Sphingobium strain Y2 were proved to be an effective strategy to remediate NP pollution in our earlier study. The purpose of this study is to investigate the influence of glucose addition on their ability to degrade NP in both liquid cultures and sediment microcosms. The shift in bacterial community structure and relative abundance of NP degraders in sediment microcosms were characterized using terminal restriction fragment length polymorphism analysis. The proportion of NP-degrading alkB and sMO genes was assessed using quantitative polymerase chain reaction (PCR) assay. The growth of Stenotrophomonas strain Y1 and its NP biodegradation efficiency were inhibited by glucose supplementation, while the relative abundance of alkB gene increased. However, NP degradation, as well as the growth of added degraders and proportion of sMO gene, was enhanced in the glucose-amended sediment microcosms inoculated with Sphingobium strain Y2. Moreover, external glucose addition altered bacterial community structures in bioaugmented sediment microcosms, depending on the level of glucose dosage. PMID:25874439

  18. Restricted streptomycin use in apple orchards did not adversely alter the soil bacteria communities.

    PubMed

    Walsh, Fiona; Smith, Daniel P; Owens, Sarah M; Duffy, Brion; Frey, Jrg E

    2013-01-01

    Streptomycin has been authorized for restricted use in the prevention of the fire blight disease of pome fruit orchards in the EU and Switzerland. This study addresses the important topic of the influence of the use of streptomycin in agriculture on the total bacteria community within the soil ecosystem. Soil samples were taken from soils under apple trees, prior to streptomycin application and 2 weeks post streptomycin application or water application (untreated control). High throughput 16S rRNA gene amplicon sequencing was used to generate datasets from the soils under apple trees in apple orchards from three different locations in Switzerland. We hypothesized that the use of streptomycin would reduce the bacterial diversity within the soil samples and enhance a reduction in the variety of taxa present. Bacterial species such as Pseudomonas, Burkholderia, and Stenotrophomonas are intrinsically resistant to many antibiotics and as such it is of interest to investigate if the use of streptomycin provided a selective advantage for these bacteria in the soil ecosystem. The application of streptomycin did not influence the abundance and diversities of major bacteria taxa of the soils or the Pseudomonas, Burkholderia, and Stenotrophomonas species. We also discovered that apple orchards under the same management practices, did not harbor the same bacterial communities. The restricted application of streptomycin in the protection of apple orchards from the fire blight pathogen Erwinia amylovora under the guidelines in Switzerland did not alter either the bacterial diversity or abundance within these soil ecosystems. PMID:24550889

  19. Distinct diversity of the czcA gene in two sedimentary horizons from a contaminated estuarine core.

    PubMed

    Kaci, Assia; Petit, Fabienne; Lesueur, Patrick; Boust, Dominique; Vrel, Anne; Berthe, Thierry

    2014-09-01

    In estuarine ecosystems, trace metals are mainly associated with fine grain sediments which settle on mudflats. Over time, the layers of sediments accumulate and are then transformed by diagenetic processes, recording the history of the estuary's chemical contamination. In such a specific environment, we investigated to what extent a chronic exposure to contaminants could affect metal-resistant sedimentary bacteria in subsurface sediments. The occurrence and diversity of cadmium resistance genes (cadA, czcA) was investigated in 5- and 33-year-old sediments from a highly contaminated estuary (Seine France). Primers were designed to detect a 252-bp fragment of the czcA gene, specifically targeting a transmembrane helice domain (TMH IV) involved in the proton substrate antiport of this efflux pump. Although the cadA gene was not detected, the highest diversity of the sequence of the czcA gene was observed in the 5-year-old sediment. According to the percentage of identity at the amino acid level, the closest CzcA relatives were identified among Proteobacteria (?, ?, ?, and ?), Verrucomicrobia, Nitrospirae, and Bacteroidetes. The most abundant sequences were affiliated with Stenotrophomonas. In contrast, in the 33-year-old sediment, CzcA sequences were mainly related to Rhodanobacter thiooxydans and Stenotrophomonas, suggesting a shaping of the metal-resistant microbial communities over time by both diagenetic processes and trace metal contamination. PMID:24894751

  20. 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

  1. Biodegradation of geosmin in drinking water by novel bacteria isolated from biologically active carbon.

    PubMed

    Zhou, Beihai; Yuan, Rongfang; Shi, Chunhong; Yu, Liying; Gu, Junnong; Zhang, Chunlei

    2011-01-01

    Three strains of Gram-negative bacteria capable of removing geosmin from drinking water were isolated from biologically active carbon and identified to be Chryseobacterium sp., Sinorhizobium sp. and Stenotrophomonas sp. based on physio-biochemistry analysis and 16S rRNA gene sequence analysis. Removal efficiencies of 2 mg/L geosmin in mineral salts medium were 84.0%, 80.2% and 74.4% for Chryseobacterium sp., Sinorhizobium sp. and Stenotrophomonas sp., respectively, while removal efficiencies of 560 ng/L geosmin in filter influent were 84.8%, 82.3% and 82.5%, respectively. The biodegradation of geosmin was determined to be a pseudo first-order reaction, with rate constants at 2 mg/L and 560 ng/L being 0.097 and 0.086 day(-1), 0.089 and 0.084 day(-1), 0.074 and 0.098 day(-1) for the above mentioned degraders, respectively. The biomass of culture in the presence of geosmin was much higher than that in the absence of geosmin. PMID:21790055

  2. Investigation on diversity and population succession dynamics of indigenous bacteria of the maize spermosphere.

    PubMed

    Liu, Yang; Zuo, Shan; Zou, Yuanyuan; Wang, Jianhua; Song, Wei

    2012-01-01

    The spermosphere, an important habitat to the plant micro-ecosystem, has a unique significance to seed microbial ecology, but has been poorly researched. In this study, the mature seeds of reciprocal cross maize (Zea mays L., Nongda108) were collected to investigate the diversity and population succession dynamics of indigenous spermosphere bacteria at 12, 24 and 36h into seed germination using 16S rDNA library construction. In the spermosphere of Nongda108A (Huang Cנ178), the dominant bacteria genera identified were Pseudomonas and Burkholderia. The proportion of Pseudomonas increased from 59.60 to 75.00% then 82.61%; while Burkholderia decreased from 39.39 to 25.00% then 15.22% at 12, 24 and 36h, respectively. Bacillus, Paenibacillus and Stenotrophomonas were the dominant genera in Nongda108B. The proportion of Paenibacillus after 12, 24 and 36h into germination decreased from 68.00 to 46.15 to 13.27%, respectively. The proportion of non-Paenibacillus genera increased from 32.00 (Stenotrophomonas) to 53.85 (Bacillus) to 77.55% (Burkholderia) from 12h to 24h to 36h, respectively. Some dominant bacteria genera identified from maize spermosphere have been identified as common PGPR. PMID:22806816

  3. 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

  4. Restricted streptomycin use in apple orchards did not adversely alter the soil bacteria communities

    PubMed Central

    Walsh, Fiona; Smith, Daniel P.; Owens, Sarah M.; Duffy, Brion; Frey, Jürg E.

    2014-01-01

    Streptomycin has been authorized for restricted use in the prevention of the fire blight disease of pome fruit orchards in the EU and Switzerland. This study addresses the important topic of the influence of the use of streptomycin in agriculture on the total bacteria community within the soil ecosystem. Soil samples were taken from soils under apple trees, prior to streptomycin application and 2 weeks post streptomycin application or water application (untreated control). High throughput 16S rRNA gene amplicon sequencing was used to generate datasets from the soils under apple trees in apple orchards from three different locations in Switzerland. We hypothesized that the use of streptomycin would reduce the bacterial diversity within the soil samples and enhance a reduction in the variety of taxa present. Bacterial species such as Pseudomonas, Burkholderia, and Stenotrophomonas are intrinsically resistant to many antibiotics and as such it is of interest to investigate if the use of streptomycin provided a selective advantage for these bacteria in the soil ecosystem. The application of streptomycin did not influence the abundance and diversities of major bacteria taxa of the soils or the Pseudomonas, Burkholderia, and Stenotrophomonas species. We also discovered that apple orchards under the same management practices, did not harbor the same bacterial communities. The restricted application of streptomycin in the protection of apple orchards from the fire blight pathogen Erwinia amylovora under the guidelines in Switzerland did not alter either the bacterial diversity or abundance within these soil ecosystems. PMID:24550889

  5. Bacterial diversity, organic pollutants and their metabolites in two aeration lagoons of common effluent treatment plant (CETP) during the degradation and detoxification of tannery wastewater.

    PubMed

    Chandra, Ram; Bharagava, Ram Naresh; Kapley, Atya; Purohit, Hemant J

    2011-02-01

    In this study, PCR-RFLP and GC-MS approaches were used to characterize the bacterial diversity, organic pollutants and metabolites during the tannery wastewater treatment process at common effluent treatment plant (CETP). Results revealed that the bacterial communities growing in aeration lagoon-I were dominated with Escherichia sp., Stenotrophomonas sp., Bacillus sp. and Cronobacter sp. while that of aeration lagoon-II prevailed with Stenotrophomonas sp., and Burkholderiales bacterium, respectively. The HPLC and GC-MS analysis revealed that most of the organic pollutants detected in untreated tannery wastewater samples were diminished from bacterial treated tannery wastewater samples. Only two pollutants i.e. L-(+)-lactic acid and acetic acid could not be degraded by bacteria whereas benzene and 2-hydroxy-3-methyl-butanoic acid was produced as new metabolites during the bacterial treatment of tannery wastewater in aeration lagoon II of CETP. Further, it was observed that after bacterial treatment, the toxicity of tannery effluent was reduced significantly allowing 90% seed germination. PMID:21075615

  6. Halorubrum laminariae sp. nov., isolated from the brine of salted brown alga Laminaria.

    PubMed

    Han, Dong; Cui, Heng-Lin

    2015-01-01

    Two halophilic archaeal strains, R60(T) and R61, were isolated from the brine of salted brown alga Laminaria. Cells of the two strains were observed to be rod-shaped, stain Gram-negative and to lyse in distilled water. Strain R60(T) was found to contain gas vacuoles and to produce pink-pigmented colonies, while strain R61 lacked gas vacuoles and produces red-pigmented colonies. Both strains were found to be able to grow at 20-50C (optimum 30C), at 1.7-4.8M NaCl (optimum 2.6-3.1M NaCl), at 0-1.0M MgCl2 (optimum 0.005-0.1M MgCl2) and at pH 6.0-9.5 (optimum pH 7.0). The major polar lipids were identified as phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and one major glycolipid chromatographically identical to a sulfated mannosyl glucosyl diether produced by Halorubrum members of the Halobacteriaceae. The 16S rRNA gene sequences of the two strains were 99.9% identical, showing 94.6-98.0% similarity to those of members of the genus Halorubrum. The EF-2 gene similarity between strains R60(T) and R60 was 100 % and showed 84.6-94.5 % similarity to those of members of the genus Halorubrum. The DNA G+C contents of the two strains were determined to be 63.0mol%. The DNA-DNA hybridization value between strain R60(T) and strain R61 was 92% and the two strains showed low DNA-DNA relatedness with the most related members of Halorubrum. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strain R60(T) (=CGMCC 1.12689(T)=JCM 30040(T)) and strain R61 (=CGMCC 1.12696) represent a novel species of the genus Halorubrum, for which the name Halorubrum laminariae sp. nov. is proposed. PMID:25367341

  7. 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??m wide and 0.9-1.5??m long; cells of X15M-8T were rods, 0.3-0.6??m wide and 1.2-2.2??m 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

  8. Marinobacter halophilus sp. nov., a halophilic bacterium isolated from a salt lake.

    PubMed

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

    2015-09-01

    A Gram-staining-negative bacterium, strain XCD-X12(T), was isolated from Xiaochaidan Lake, a salt lake (salinity 9.9%, w/w) in Qaidam basin, Qinghai Province, China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain XCD-X12(T) were non-spore-forming rods, 0.4-0.7 ?m wide, 2.1-3.2 ?m long and motile with a single polar flagellum. Strain XCD-X12(T) was strictly aerobic and catalase- and oxidase-positive. Growth was observed in the presence of 0-20.0% (w/v) NaCl (optimum, 4.0-8.0%), at 4-35 C (optimum, 30 C) and at pH 6.5-10.5 (optimum, pH 8.5). It contained Q-9 as the predominant respiratory quinone. The major fatty acids (>10.0%) were C16 : 0, C16 : 1?9c and C18 : 1?9c. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two unknown phospholipids and an uncharacterized aminophospholipid. The DNA G+C content was 55.6 mol% (Tm). Phylogenetic trees based on 16S rRNA gene sequences showed that strain XCD-X12(T) was associated with the genus Marinobacter, and showed the highest 16S rRNA gene sequence similarity to Marinobacter hydrocarbonoclasticus ATCC 49840(T) (97.4%), M. vinifirmus FB1(T) (96.8%), M. excellens KMM 3809(T) (96.8%) and M. antarcticus ZS2-30(T) (96.7%). DNA-DNA relatedness of strain XCD-X12(T) to M. hydrocarbonoclasticus CGMCC 1.7683(T) was 34 5%. Based on these data, it is concluded that strain XCD-X12(T) represents a novel species of the genus Marinobacter, for which the name Marinobacter halophilus sp. nov. is proposed. The type strain is XCD-X12(T) (?=?CGMCC 1.12481(T)= JCM 30472(T)). PMID:25985830

  9. Vibrio salilacus sp. nov., a new member of the Anguillarum clade with six alleles of the 16S rRNA gene from a saline lake.

    PubMed

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

    2015-08-01

    A Gram-stain-negative, catalase- and oxidase-positive, facultatively aerobic bacterium, strain DSG-S6T, was isolated from Dasugan Lake (salinity 3.1%, w/w), China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain DSG-S6T were non-spore-forming, slightly bent rods, and motile by means of a single polar flagellum. Growth occurred in the presence of 0-7.0% (w/v) NaCl (optimum, 2.0%), at 4-35?C (optimum, 30?C) and at pH?6.0-10.5 (optimum, pH?8.0-8.5). C16?:?0, C18?:?1?7c and C16?:?1?7c and/or C16?:?1?6c were the major fatty acids. Six alleles of the 16S rRNA gene sharing 98.9-99.9??% similarity were detected in strain DSG-S6T, which showed highest 16S rRNA gene sequence similarity to Vibrio aestuarianus ATCC 35048T (97.7?%), then to Vibrio pacinii LMG 19999T (97.6%) and Vibrio metschnikovii CIP 69.14T (96.8%). Multilocus sequence analysis of four housekeeping genes and 16S rRNA genes clearly clustered it as a member of the Anguillarum clade. Mean DNA-DNA relatedness between strain DSG-S6T and V. aestuarianus NBRC 15629T, V. pacinii CGMCC 1.12557T and V. metschnikovii JCM 21189T was 20.6??2.3, 38.1??3.5 and 24.2??2.8%, respectively. The DNA G+C content was 46.8?mol% (Tm). Based on the data, it is concluded that strain DSG-S6T represents a novel species of the genus Vibrio, for which the name Vibrio salilacus sp. nov. is proposed. The type strain is DSG-S6T (?=?CGMCC 1.12427T?=?JCM 19265T). PMID:25964518

  10. 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

  11. 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.

  12. Outer membrane protein D2 catalyzes facilitated diffusion of carbapenems and penems through the outer membrane of Pseudomonas aeruginosa.

    PubMed Central

    Trias, J; Nikaido, H

    1990-01-01

    The outer membrane of imipenem-resistant mutants of Pseudomonas aeruginosa with decreased permeability to imipenem was shown by Western (immuno-) blotting to contain protein D1 and to lack protein D2. Protein D2 was purified and was shown to allow the permeation of imipenem at a rate higher than expected from its molecular weight. Spontaneous imipenem-resistant mutants of P. aeruginosa PAO1 appeared at a frequency of 10(-8) in the laboratory and did not synthesize protein D2. Experiments performed with intact cells carrying plasmid pHN4 containing the gene for L-1 beta-lactamase from Pseudomonas maltophilia showed that this channel could also be used by SM-7338, Sch 33755, and Sch 33440 but apparently not by Sch 34343 or Sch 29482. Images PMID:2109575

  13. Monoclonal antibodies to Pseudomonas aeruginosa ferripyochelin-binding protein.

    PubMed Central

    Sokol, P A; Woods, D E

    1986-01-01

    Hybridomas secreting specific monoclonal antibodies against the Pseudomonas aeruginosa ferripyochelin-binding protein (FBP) were isolated. These monoclonal antibodies reacted with FBP in immunoblots of outer membrane preparations from all serotypes of P. aeruginosa. Two of the monoclonal antibodies also reacted with FBP in strains of P. putida, P. fluorescens, and P. stutzeri. These antibodies did not react with outer membranes of P. cepacia, "P. multivorans," P. maltophilia, or other gram-negative organisms. The monoclonal antibodies were opsonophagocytic and blocked the binding of [59Fe]ferripyochelin to isolated outer membranes of strain PAO. By indirect immunofluorescence techniques, the monoclonal antibodies were used to demonstrate that FBP is present on the cell surface of P. aeruginosa cells grown in low-iron but not high-iron medium. These observations were confirmed by using 125I in surface-labeling techniques. Images PMID:3091506

  14. Bacteriocuprein superoxide dismutases in pseudomonads

    SciTech Connect

    Steinman, H.M.

    1985-06-01

    Two new instances of the rare bacteriocuprein form of superoxide dismutase have been discovered in Pseudomonas diminuta and P. maltophilia. Each species contains a manganese superoxide dismutase as well. Eight other strains of Pseudomonas and Xanthomonas spp. lacked bacteriocupreins and contained either a manganese or an iron superoxide dismutase. Native molecular weights and isoelectric points were determined for all these bacterial dismutases. A monospecific polyclonal antibody was prepared against the bacteriocuprein from Photobacterium leiognathi; it was not cross-reactive with the bacteriocuprein from either Pseudomonas strain. Bacteriocupreins have previously been identified in only two procaryotes, P. leiognathi and Caulobacter crescentus. The discovery of the Pseudomonas bacteriocupreins reveals a broader distribution, raising the possibility that bacteriocupreins are a continuous line of descent among procryotes and not isolated evolutionary occurrences, as previous data suggested.

  15. Screening of high ?-arbutin producing strains and production of ?-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 ?-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 ?-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 ?-arbutin were 120 mM and 30.6 g/l, respectively. The molar conversion yield of ?-arbutin based on the amount of HQ supplied reached 93.6 %. The product was identified as ?-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 ?-arbutin. PMID:23456857

  16. Best conditions for biodegradation of diesel oil by chemometric tools

    PubMed Central

    Kaczorek, Ewa; Bielicka-Daszkiewicz, Katarzyna; Hberger, Kroly; Kemny, Sndor; 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

  17. 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.

  18. ESTIMATING BACTERIAL DIVERSITY IN SCIRTOTHRIPS DORSALIS (THYSANOPTERA: THRIPIDAE) VIA NEXT GENERATION SEQUENCING

    PubMed Central

    Dickey, Aaron M.; Trease, Andrew J.; Jara-Cavieres, Antonella; Kumar, Vivek; Christenson, Matthew K.; Potluri, Lakshmi-Prasad; Morgan, J. Kent; Shatters, Robert G.; Mckenzie, Cindy L.; Davis, Paul H.; Osborne, Lance S.

    2014-01-01

    The last 2 decades have produced a better understanding of insect-microbial associations and yielded some important opportunities for insect control. However, most of our knowledge comes from model systems. Thrips (Thysanoptera: Thripidae) have been understudied despite their global importance as invasive species, plant pests and disease vectors. Using a culture and primer independent next-generation sequencing and metagenomics pipeline, we surveyed the bacteria of the globally important pest, Scirtothrips dorsalis Hood. The most abundant bacterial phyla identified were Actinobacteria and Proteobacteria and the most abundant genera were Propionibacterium, Stenotrophomonas, and Pseudomonas. A total of 189 genera of bacteria were identified. The absence of any vertically transferred symbiont taxa commonly found in insects is consistent with other studies suggesting that thrips primarilly acquire resident microbes from their environment. This does not preclude a possible beneficial/intimate association between S. dorsalis and the dominant taxa identified and future work should determine the nature of these associations. PMID:25382863

  19. Molecular characterization of nitrogen-fixing bacteria isolated from brazilian agricultural plants at So Paulo state

    PubMed Central

    Reinhardt, rica. L.; Ramos, Patrcia 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

  20. Best conditions for biodegradation of diesel oil by chemometric tools.

    PubMed

    Kaczorek, Ewa; Bielicka-Daszkiewicz, Katarzyna; Héberger, Károly; Kemény, Sándor; Olszanowski, Andrzej; Voelkel, Adam

    2014-01-01

    Diesel oil biodegradation by different bacteria-yeast-rhamnolipids consortia was tested. Chromatographic analysis of post-biodegradation residue was completed with chemometric tools (ANOVA, and a novel ranking procedure based on the sum of ranking differences). These tools were used in the selection of the most effective systems. The best results of aliphatic fractions of diesel oil biodegradation were observed for a yeast consortia with Aeromonas hydrophila KR4. For these systems the positive effect of rhamnolipids on hydrocarbon biodegradation was observed. However, rhamnolipids addition did not always have a positive influence on the biodegradation process (e.g. in case of yeast consortia with Stenotrophomonas maltophila KR7). Moreover, particular differences in the degradation pattern were observed for lower and higher alkanes than in the case with C22. Normally, the best conditions for "lower" alkanes are Aeromonas hydrophila KR4 + emulsifier independently from yeasts and e.g. Pseudomonas stutzeri KR7 for C24 alkane. PMID:24948922

  1. Medical and surgical management of severe inflammation of the nictitating membrane in a Giant Panda (Ailuropoda melanoleuca).

    PubMed

    Boedeker, Nancy C; Walsh, Timothy; Murray, Suzan; Bromberg, Nancy

    2010-09-01

    A 10-year-old male giant panda (Ailuropoda melanoleuca) presented for severe, acute swelling and protrusion of the right nictitating membrane, unresponsive to topical therapy. Excisional biopsy of the nictitating membrane and its associated lacrimal gland was elected due to necrosis and friability of the tissue. Histopathology revealed suppurative, necrotizing conjunctivitis and dacryoadenitis. Culture grew Stenotrophomonas maltophila and Enterococcus spp with extensive antibiotic resistance. Treatment with topical and systemic antibiotics based on sensitivity results was initiated. All treatments were well tolerated. Healing was uncomplicated with no recurrence of the lesion and no clinical evidence of keratoconjunctivitis sicca. Ophthalmic exams and Schirmer tear tests performed opportunistically during postoperative anesthetic procedures were unremarkable, confirming that excision of the nictitating membrane had not caused clinically significant detrimental effects. The etiology of this lesion remains undetermined, but trauma is suspected. To the authors' knowledge, this is the first report of nictitating membrane pathology and excision in the giant panda. PMID:20840099

  2. Bacteria associated with orchid roots and microbial production of auxin.

    PubMed

    Tsavkelova, Elena A; Cherdyntseva, Tatiana A; Botina, Svetlana G; Netrusov, Alexander I

    2007-01-01

    Associative bacteria of terrestrial (Paphiopedilum appletonianum) and epiphytic (Pholidota articulata) tropical orchids were investigated. Microbial community of epiphytic plant differed from that of the terrestrial one. Streptomyces, Bacillus, Pseudomonas, Burkholderia, Erwinia and Nocardia strains populated Paphiopedilum roots, whereas Pseudomonas, Flavobacterium, Stenotrophomonas, Pantoea, Chryseobacterium, Bacillus, Agrobacterium, Erwinia, Burkholderia and Paracoccus strains colonized Pholidota roots. Endophytic bacteria populations were represented with less diversity: Streptomyces, Bacillus, Erwinia and Pseudomonas genera were isolated from P. appletonianum, and Pseudomonas, Bacillus, and Flavobacterium genera were isolated from Ph. articulata. Microorganisms produced indole-3-acetic acid (IAA). Variations in its biosynthesis among the strains of the same genus were also observed. The highest auxin level was detected during the stationary growth phase. Biological activity of microbial IAA was proved by treatment of kidney bean cuttings with bacterial supernatants, revealing considerable stimulation of root formation and growth. PMID:17140781

  3. Identification and analysis of polyaromatic hydrocarbons (PAHs)--biodegrading bacterial strains from refinery soil of India.

    PubMed

    Chaudhary, Priyanka; Sahay, Harmesh; Sharma, Richa; Pandey, Alok Kumar; Singh, Shashi Bala; Saxena, A K; Nain, Lata

    2015-06-01

    Polyaromatic hydrocarbons (PAHs) utilizing bacteria were isolated from soils of seven sites of Mathura refinery, India. Twenty-six bacterial strains with different morphotypes were isolated. These strains were acclimatized to utilize a mixture of four polycyclic aromatic hydrocarbons, i.e., anthracene, fluorene, phenanthrene, and pyrene, each at 50 mg/L concentration as sole carbon source. Out of total isolates, 15 potent isolates were subjected to 16S rDNA sequencing and identified as a member of diverse genera, i.e., Bacillus, Acinetobacter, Stenotrophomonas, Alcaligenes, Lysinibacillus, Brevibacterium, Serratia, and Streptomyces. Consortium of four promising isolates (Acinetobacter, Brevibacterium, Serratia, and Streptomyces) were also investigated for bioremediation of PAH mixture. This consortium was proved to be efficient PAH degrader resulting in 40-70 % degradation of PAH within 7 days. Results of this study indicated that these genera may play an active role in bioremediation of PAHs. PMID:26026847

  4. Molecular characterization of nitrogen-fixing bacteria isolated from brazilian agricultural plants at São Paulo state.

    PubMed

    Reinhardt, Erica L; Ramos, Patrícia L; Manfio, Gilson P; Barbosa, Heloiza R; Pavan, Crodowaldo; Moreira-Filho, Carlos A

    2008-07-01

    Fourteen strains of nitrogen-fixing bacteria were isolated from different agricultural plant species, including cassava, maize and sugarcane, using nitrogen-deprived selective isolation conditions. Ability to fix nitrogen was verified by the acetylene reduction assay. All potentially nitrogen-fixing strains tested showed positive hybridization signals with a nifH probe derived from Azospirillum brasilense. The strains were characterized by RAPD, ARDRA and 16S rDNA sequence analysis. RAPD analyses revealed 8 unique genotypes, the remaining 6 strains clustered into 3 RAPD groups, suggesting a clonal origin. ARDRA and 16S rDNA sequence analyses allowed the assignment of 13 strains to known groups of nitrogen-fixing bacteria, including organisms from the genera Azospirillum, Herbaspirillum, Pseudomonas and Enterobacteriaceae. Two strains were classified as Stenotrophomonas ssp. Molecular identification results from 16S rDNA analyses were also corroborated by morphological and biochemical data. PMID:24031239

  5. Community structure analysis of reverse osmosis membrane biofilms and the significance of Rhizobiales bacteria in biofouling.

    PubMed

    Pang, Chee Meng; Liu, Wen-Tso

    2007-07-01

    The biofilm community structure of a biofouled reverse osmosis (RO) membrane was examined using a polyphasic approach, and the dominant phylotypes retrieved were related to the order Rhizobiales, a group of bacteria that is hitherto not implicated in membrane biofouling. A comparison with two other membrane biofilms using T-RFLP fingerprinting also revealed the dominance of Rhizobiales organisms. When pure culture RO biofilm isolates were cultivated aerobically in BIOLOG microplates, most Rhizobiales were metabolically versatile in their choice of carbon substrates. Nitrate reduction was observed in five RO isolates related to Castellaniella, Ochrobactrum, Stenotrophomonas, and Xanthobacter. Many of the key Rhizobiales genera including Bosea, Ochrobactrum, Shinella, and Rhodopseudomonas were detected by PCR to contain the nirK gene responsible for nitrite reductase activity. These findings suggest that Rhizobiales organisms are ecologically significant in membrane biofilm communities under both aerobic and anoxic conditions and may be responsible for biofouling in membrane separation systems. PMID:17695921

  6. Characterization of bacterial communities in hybrid upflow anaerobic sludge blanket (UASB)-membrane bioreactor (MBR) process for berberine antibiotic wastewater treatment.

    PubMed

    Qiu, Guanglei; Song, Yong-Hui; Zeng, Ping; Duan, Liang; Xiao, Shuhu

    2013-08-01

    Biodegradation of berberine antibiotic was investigated in upflow anaerobic sludge blanket (UASB)-membrane bioreactor (MBR) process. After 118days of operation, 99.0%, 98.0% and 98.0% overall removals of berberine, COD and NH4(+)-N were achieved, respectively. The detailed composition of the established bacterial communities was studied by using 16S rDNA clone library. Totally, 400 clones were retrieved and grouped into 186 operational taxonomic units (OTUs). UASB was dominated by Firmicutes and Bacteroidetes, while Proteobacteria, especially Alpha- and Beta-proteobacteria were prevalent in the MBRs. Clostridium, Eubacterium and Synergistes in the UASB, as well as Hydrogenophaga, Azoarcus, Sphingomonas, Stenotrophomonas, Shinella and Alcaligenes in the MBRs were identified as potential functional species in biodegradation of berberine and/or its metabolites. The bacterial community compositions in two MBRs were significantly discrepant. However, the identical functions of the functional species ensured the comparable pollutant removal performances in two bioreactors. PMID:23735790

  7. Culturable aerobic bacteria from the upstream region of a karst water rivulet.

    PubMed

    Cousin, Sylvie; Brambilla, Evelyne; Yang, Jun; Stackebrandt, Erko

    2008-06-01

    The composition of 681 aerobic and heterotrophic strains that were isolated on two different media was assessed at four sampling points along a approximately 300 m stretch of a karst water rivulet. Based on partial sequence analysis of 16S rRNA genes, members of 35 genera were identified; however, only a few species dominated as their representatives were repeatedly isolated at different sampling sites. Determination of the phylum affiliation showed that the isolates included members of Bacteriodetes (especially the genus Flavobacterium) and Proteobacteria (mainly Pseudomonas and Stenotrophomonas). MALDI-TOF analysis and/or similarities of partial sequences of flavobacterial strains resulted in the generation of almost complete 16S rRNA gene sequences for 100 isolates, about 60 of which may represent novel phylospecies. The number as well as the intra-phylum distribution of the isolates changed with distance from the discharge site. While phylogenetically restricted at the spring, diversity increased at downstream sampling sites. PMID:18645959

  8. Isolation of a selected microbial consortium capable of degrading methyl parathion and p-nitrophenol from a contaminated soil site.

    PubMed

    Pino, Nancy J; Dominguez, Maria C; Penuela, Gustavo A

    2011-01-01

    A bacterial consortium with the ability to degrade methyl parathion and p-nitrophenol, using these compounds as the only carbon source, was obtained by selective enrichment in a medium with methyl parathion. Samples were taken from Moravia, Medellin; an area that is highly contaminated, owing to the fact that it was used as a garbage dump from 1974 to 1982. Acinetobacter sp, Pseudomonas putida, Bacillus sp, Pseudomonas aeruginosa Citrobacter freundii, Stenotrophomonas sp, Flavobacterium sp, Proteus vulgaris, Pseudomonas sp, Acinetobacter sp, Klebsiella sp and Proteus sp were the microorganisms identified within the consortium. In culture, the consortium was able to degrade 150 mg L? of methyl-parathion and p-nitrophenol in 120 h, but after adding glucose or peptone to the culture, the time of degradation decreased to 24 h. In soil, the consortium was also able to degrade 150 mg L? of methyl parathion in 120 h at different depths and also managed to decrease the toxicity. PMID:21328125

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

    PubMed

    Zhao, Xuebing; Song, Yuanquan; Liu, Dehua

    2011-09-10

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

  11. Salinicoccus halodurans sp. nov., a moderate halophile from saline soil in China.

    PubMed

    Wang, Xiaowei; Xue, Yanfen; Yuan, Sanqing; Zhou, Cheng; Ma, Yanhe

    2008-07-01

    A moderately halophilic, Gram-positive coccus, designated strain W24(T), was isolated from saline soil in Qinghai province, China. The isolate was able to grow at salinities of 0-24 % (w/v) NaCl (optimally at 8 %, w/v), at pH 5.5-9.0 (optimally at pH 7.5) and at 8-43 degrees C (optimally at 28 degrees C). The genomic DNA G+C content of strain W24(T) was 45.8 mol%. The predominant isoprenoid quinone was MK-6 and the cell wall contained lysine and glycine as diagnostic diamino acids. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid. The major cellular fatty acids were iso-C(15 : 0), anteiso-C(15 : 0) and C(16 : 0). Based on 16S rRNA gene sequence analysis, strain W24(T) was found to be a member of the genus Salinicoccus and was related most closely to Salinicoccus hispanicus DSM 5352(T) (96.5 % sequence similarity). Based on data from the current polyphasic study, strain W24(T) is considered to represent a novel species of the genus Salinicoccus, for which the name Salinicoccus halodurans sp. nov. is proposed. The type strain is W24(T) (=CGMCC 1.6501(T)=DSM 19336(T)). PMID:18599690

  12. Asymmetric synthesis of duloxetine intermediate (S)-(-)-3-N-methylamino-1-(2-thienyl)-1-propanol using immobilized Saccharomyces cerevisiae in liquid-core sodium alginate/chitosan/sodium alginate microcapsules.

    PubMed

    Zhimin, Ou; Haibing, Zhao; Lan, Tang; Wei, Zhang; Gensheng, Yang

    2014-11-01

    Duloxetine intermediate (S)-(-)-3-N-methylamino-1-(2-thienyl)-1-propanol was synthesized using ACA liquid-core immobilized Saccharomyces cerevisiae CGMCC No. 2230. The optimum culture time for ACA liquid-core immobilized cells was found to be 28 h. The optimum ACA liquid-core capsule formation conditions were found to be 90% chitosan deacetylation, 30,000-50,000 chitosan molecular weight, 5.0 g/L chitosan, and pH 6.0 citrate buffer solution. The highest activity was found when reduction conditions were pH 6.0, 30 °C and 180 rpm. The ACA-immobilized cells can be reused nine times and only 40% of the activity is retained after nine cycles. Product inhibition of reduction was observed in batch reduction. Continuous reduction in the membrane reactor was found to remove the product inhibition on reduction and improve production capacity. Conversion reached 100% and enantiometric excess of (S)-(-)-3-N-methylamino-1-(2-thienyl)-1-propanol exceeded 99.0% in continuous reduction of 5 g/L 3-N-methylamino-1-(2-thienyl)-1-propanone in the membrane reactor. PMID:24798376

  13. Rufibacter glacialis sp. nov., a psychrotolerant bacterium isolated from glacier soil.

    PubMed

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

    2016-01-01

    A Gram-stain-negative, rod-shaped, red-pigmented bacterium (MDT1-10-3T) was isolated from Midui glacier in Tibet, China. Cells were aerobic and psychrotolerant (growth occurred at 4-25?C). Phylogenetic analysis based on 16S rRNA gene sequences indicated that it was a member of the genus Rufibacter, with Rufibacter immobilis MCC P1T (96.7?% similarity) as its closest phylogenetic relative. MK-7 was the predominant respiratory menaquinone. The major cellular fatty acids were summed feature 4 (iso-C17?:?1 I and/or anteiso-C17?:?1 B), summed feature 3 (C16?:?1?6c and/or C16?:?1?7c), C17?:?1?6c, iso-C16?:?0, iso-C15?:?0 and C16?:?1?5c. The predominant polar lipids were phosphatidylethanolamine, two unidentified aminophospholipids, one glycolipid and four unidentified lipids. The G+C content of the genomic DNA was 49?mol%. On the basis of the phenotypic characteristics and phylogenetic analysis, strain MDT1-10-3T represents a novel species of the genus Rufibacter, for which the name Rufibacter glacialis sp. nov. is proposed. The type strain is MDT1-10-3T (?=?CGMCC 1.9789T?=?NBRC 109705T). PMID:26510965

  14. Halorientalis brevis sp. nov., Isolated from an Inland Salt Lake of China.

    PubMed

    Yuan, Pan-Pan; Yin, Shuai; Han, Dong; Zhang, Wen-Jiao; Cui, Heng-Lin

    2015-09-01

    Halophilic archaeal strain YC89(T) was isolated from Yuncheng salt lake in Shanxi, China. Cells from strain YC89(T) were short rods, lysed in distilled water, stained Gram-negative and formed red-pigmented colonies on agar plate. Strain YC89(T) was able to grow at 25-50C (optimum 37C), at 1.4-4.8 M NaCl (optimum 2.6-3.1 M), at 0-1.0 M MgCl2 (optimum 0.3 M) and at pH 6.0-9.5 (optimum pH 7.5). The major polar lipids are phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, sulfated mannosyl glucosyl diether and two unknown glycolipids. 16S rRNA gene analysis revealed that strain YC89(T) was phylogenetically related to Halorientalis persicus D108(T) (95.6% nucleotide identity) and H. regularis TNN28(T) (95.3% nucleotide identity). The rpoB' gene similarities between strain YC89(T) and H. persicus IBRC-M 10043(T) and H. regularis TNN28(T) were 88.1 and 88.0%, respectively. The DNA G+C content of strain YC89(T) was determined to be 61.3 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YC89(T) (=CGMCC 1.12125(T) = JCM 18366(T)) represents a new species of Halorientalis, for which the name H. brevis sp. nov. is proposed. PMID:26134535

  15. Prauserella endophytica sp. nov., an endophytic actinobacterium isolated from Tamarix taklamakanensis.

    PubMed

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

    2015-06-01

    A novel endophytic actinobacterium, designated strain SP28S-3(T), was isolated from a surface-sterilized stem of Tamarix taklamakanensis collected from the southern edge of Taklamakan desert, Xinjiang, China. Strain SP28S-3(T) was found to show chemotaxonomic and morphological properties consistent with its classification in the genus Prauserella. The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphoglycolipid, phosphatidylcholine, phosphatidylinositol, a glycolipid, an aminolipid and unidentified phospholipids. The major fatty acids (>10%) were identified as iso-C16:0 and C16:0. The genomic DNA G+C content was determined to be 69.7mol%. Phylogenetic analysis of strain SP28S-3(T) clearly showed that the strain had the highest similarity of 16S rRNA gene sequence with Prauserella coralliicola SCSIO 11529(T) (99.9%), followed by Prauserella marina DSM 45268(T) (97.0%) and is affiliated with the genus Prauserella. The low level (47.85.5%) of DNA-DNA relatedness between strain SP28S-3(T) and P. coralliicola SCSIO 11529(T) combined with other polyphasic taxonomic evidence clearly support the conclusion that strain SP28S-3(T) represents a novel Prauserella species, for which the name Prauserella endophytica sp. nov. is proposed. The type strain is SP28S-3(T) (=DSM 46655(T)=CGMCC 4.7182 (T)). PMID:25832628

  16. Complete genome sequence of the heavy metal resistant bacterium Altererythrobacter atlanticus 26DY36(T), isolated from deep-sea sediment of the North Atlantic Mid-ocean ridge.

    PubMed

    Wu, Yue-Hong; Cheng, Hong; Zhou, Peng; Huo, Ying-Yi; Wang, Chun-Sheng; Xu, Xue-Wei

    2015-12-01

    Altererythrobacter atlanticus 26DY36(T) (CGMCC 1.12411(T)=JCM 18865(T)) was isolated from the North Atlantic Mid-Ocean Ridge. The strain is resistant to heavy metals, such as Mn(2+) (200mM), Co(2+) (2.0mM), Cu(2+) (1mM), Zn(2+) (1mM), Hg(2+) (0.1mM) and Cd(2+) (0.5mM). Here we describe the genome sequence and annotation, as well as the features of the organism. A. atlanticus 26DY36(T) harbors a chromosome (3,386,291bp) and a circular plasmid (88,815bp). The genome contains 3322 protein-coding genes (2483 with predicted functions), 47 tRNA genes and 6 rRNA genes. A. atlanticus 26DY36(T) encodes dozens of genes related to heavy metal resistance and has potential applications in the bioremediation of heavy metal-contaminated environments. PMID:26508671

  17. Streptomyces vulcanius sp. nov., a novel actinomycete isolated from volcanic sediment.

    PubMed

    Jia, Feiyu; Liu, Chongxi; Zhao, Junwei; Zhang, Yuejing; Li, Lianjie; Zhou, Shuyu; Shen, Yue; Wang, Xiangjing; Xiang, Wensheng

    2015-01-01

    A novel actinomycete, designated strain NEAU-C3(T), was isolated from volcanic sediment collected from Longwan, Jilin province, north China and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of the members of the genus Streptomyces. EzTaxon-e analysis of the 16S rRNA gene sequence indicated strain NEAU-C3(T) to be most closely related to Streptomyces hygroscopicus subsp. ossamyceticus JCM 4965(T) (97.7% sequence similarity) and Streptomyces torulosus JCM 4872(T) (97.7%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-C3(T) belongs within the genus Streptomyces and forms a separate subclade, an association that was supported by a bootstrap value of 72% in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. The DNA-DNA hybridization values between strain NEAU-C3(T) and the two most closely related type strains were low enough to justify the assignment of the strain to a novel species. On the basis of these phenotypic, phylogenetic and chemotaxonomic characteristics, it is concluded that strain NEAU-C3(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces vulcanius sp. nov. is proposed. The type strain is NEAU-C3(T) (=CGMCC 4.7177(T)=DSM 42139(T)). PMID:25294726

  18. Binariimonas pacifica gen. nov., sp. nov., a Novel Marine Bacterium of Family Sphingomonadaceae Isolated from East Pacific Ocean Surface Seawater.

    PubMed

    Zhao, Zhao; Sun, Jia; Zhang, Rui; Jiao, Nianzhi

    2016-03-01

    A novel rod-shaped binary fission, and yellow-pigmented bacterial strain, JLT 2480(T), was isolated from surface seawater in the East Pacific Ocean. The strain is Gram negative and oxidase negative. Phylogenetic analyses based on 16S rRNA gene sequence indicate that strain JLT 2480(T) falls in the family Sphingomonadaceae, sharing highest similarity (95.6%) with the species Blastomonas ursincola. The DNA G+C content of JLT 2480(T) is 65.5mol%, and the sole respiratory quinone is coenzyme Q10. The predominant polar lipids are sphingoglycolipids (SGL1 and SGL2), phosphatidylglycerols, phosphatidylethanolamines, phospholipids, glycolipids, and phosphatidylcholines. The predominant cellular fatty acids are C16:0, C18:0, C18:1?7c, C12:0, and C16:1?7c. Strain JLT 2480(T) is distinct from the B. ursincola type strain DSM 9006(T) as reflected by major chemotaxonomic distinctions between the two. Furthermore, two notable characteristics of the genus Blastomonas, that is, the presence of bacteriochlorophyll a and the puf genes, are not detected in JLT 2480(T). On the basis of present evidence, we consider JLT 2480(T) to be a novel species in a new genus of the family Sphingomonadaceae, and propose the name Binariimonas pacifica gen. nov., sp. nov., with strain JLT 2480(T) (=CGMCC 1.12850(T)=DSM 28646(T)) to be the type strain for genus Binariimonas. PMID:26613616

  19. Thiobacimonas profunda gen. nov., sp. nov., a member of the family Rhodobacteraceae isolated from deep-sea water.

    PubMed

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

    2015-02-01

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

  20. Pelagibaca abyssi sp. nov., of the family Rhodobacteraceae, isolated from deep-sea water.

    PubMed

    Lin, Yingfang; Tang, Kai; Li, Shuhui; Liu, Keshao; Sun, Jia; Jiao, Nianzhi

    2014-09-01

    A Gram-stain negative, oval-shaped, aerobic, catalase and oxidase-positive bacterium, designated JLT2014(T), was isolated from a deep-seawater sample (obtained at a 2,000 m depth) of the Southeastern Pacific Ocean. The dominant fatty acids were identified as C18:1?7c/C18:1?6c, C16:0 and C10:0 3-OH, which altogether represented 60.1 % of the total. The predominant respiratory quinone was identified as Q-10. The G+C content of genomic DNA was determined to be 66.4 mol %. The major polar lipids were identified as phosphatidylethanolamine and diphosphatidylglycerol. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the novel isolate can be affiliated with the Roseobacter clade within the family Rhodobacteraceae. Strain JLT2014(T) exhibited highest 16S rRNA gene sequence similarity value to Pelagibaca bermudensis HTCC2601(T) (sequence similarity value: 97.6 %). The DNA-DNA relatedness value between strain JLT2014(T) and P. bermudensis HTCC2601(T) was 46.9 2 %. Based on phenotypic properties and phylogenetic analysis, the name Pelagibaca abyssi sp. nov. is proposed, with JLT2014(T)(=LMG 27363(T)=CGMCC 1.12376(T)) as the type strain. PMID:24969947

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

    PubMed

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

    2015-10-01

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

  2. Improving the productivity of propionic acid with FBB-immobilized cells of an adapted acid-tolerant Propionibacterium acidipropionici.

    PubMed

    Zhu, Linqi; Wei, Peilian; Cai, Jin; Zhu, Xiangcheng; Wang, Zimeng; Huang, Lei; Xu, Zhinan

    2012-05-01

    Propionic acid is an important short-chain fatty acid with many applications, but its large-scale bioproduction was hindered by the low productivity. An adapted acid-tolerant Propionibacterium acidipropionici CGMCC 1.2230 strain was selected to produce propionic acid with a relatively high productivity (0.29 g/(Lh)) in the free-cell fermentation. Further immobilized-cell fermentation in fibrous-bed bioreactor (FBB) supported high-level repeated batch fermentations with a high productivity of 0.96 g/(Lh). The FBB also presents the potential to increase final propionic acid concentration by using glucose feeding strategy. The propionic acid concentration was increased to 51.2g/L in the fed-batch fermentation with the productivity of 0.71 g/(Lh). By adopting the above strategies, sugarcane bagasse hydrolysate could support the production of propionic acid with high productivity in the repeat-batch and fed-batch fermentations. The present work would pave one road to the accomplishment of large-scale bioproduction of propionic acid from renewable resources. PMID:22406066

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2015-12-01

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

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

    PubMed

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

    2015-04-01

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

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

    PubMed

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

    2015-02-01

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

  7. Genetic diversity of endophytic diazotrophs of the wild rice, Oryza alta and identification of the new diazotroph, Acinetobacter oryzae sp. nov.

    PubMed

    Chaudhary, Hassan Javed; Peng, Guixiang; Hu, Mei; He, Yumei; Yang, Lijuan; Luo, Yan; Tan, Zhiyuan

    2012-05-01

    Thirty-three endophytic diazotrophs were isolated from surface-sterilized leaves, stem, and roots of wild rice Oryza alta. The SDS-PAGE profile of total protein and insertion sequence-based polymerase chain reaction (IS-PCR) fingerprinting grouped the isolates into four clusters (I-IV). The 16S rRNA gene sequence homology of the representative strains B21, B31, B1, and B23 of clusters I, II, III, and IV were assigned to Pseudomonas oleovorans (99.2% similarity), Burkholderia fungorum (99.4% similarity), Enterobacter cloacae (98.9% similarity), and Acinetobacter johnsonii (98.4% similarity), respectively. The results showed wide genetic diversity of the putative diazotrophic strains of the wild rice, O. alta, and the strains of cluster IV are the first report of nitrogen-fixing Acinetobacter species. The cell size, phenotypic characters, total protein profile, genomic DNA fingerprinting, DNA-DNA hybridization, and antibiotic resistance differentiated strain B23(T) from its closest relatives A. johnsonii LMG999(T) and Acinetobacter haemolyticus LMG996(T). The DNA-DNA hybridization also distinguished the strain B23(T) from the closely related Acinetobacter species. Based on these data, a novel species, Acinetobacter oryzae sp. nov., and strain B23(T) (=LMG25575(T)?=?CGMCC1.10689(T)) as the type strain were proposed. PMID:22105517

  8. Diverse endophytic nitrogen-fixing bacteria isolated from wild rice Oryza rufipogon and description of Phytobacter diazotrophicus gen. nov. sp. nov.

    PubMed

    Zhang, Guo Xia; Peng, Gui Xiang; Wang, En Tao; Yan, Hui; Yuan, Qing Hua; Zhang, Wu; Lou, Xu; Wu, Hui; Tan, Zhi Yuan

    2008-05-01

    Twenty-three nitrogen-fixing bacteria were isolated from surface-sterilized stems and roots of wild rice Oryza rufipogon. Four clusters were defined among these bacteria by SDS-PAGE protein patterns and further confirmed by IS-PCR finger-printing analysis. Phylogenetic analysis of 16S rRNA gene sequences showed that the representative strains LS 8 and LS 18 of cluster II formed a monophyletic group sharing 94.0-97.3% similarities with defined enterobacterial species within the genera Salmonella, Citrobacter, Pantoea, Klebsiella, and Enterobacter. DNA-DNA hybridization, physiological, biochemical tests, and cell morphology also revealed that these strains could be differentiated from the related enterobacterial species. Based upon these results, we propose Phytobacter diazotrophicus gen. nov., sp. nov. to the bacterial group represented by strains LS 8 and LS 18. The type strain is LS 8(T) (=DSM 17806(T) = LMG 23328(T) = CGMCC 1.5339(T)). The DNA G+C content of strain LS 8(T) is 58.6 +/- 0.5 mol%. PMID:18060384

  9. Paenibacillus nasutitermitis sp. nov., isolated from a termite gut.

    PubMed

    Wang, Xue Min; Ma, Shichun; Yang, Shu Yan; Peng, Rong; Zheng, Ying; Yang, Hong

    2016-02-01

    A Gram-stain-positive, non-motile, aerobic and terminal-endospore-forming rod-shaped bacterium, strain P5-1T, was isolated from the hindgut of a wood-feeding higher termite, Nasutitermes sp. Phylogenetic analysis of 16S rRNA gene sequences showed that the strain was closely related to Paenibacillus sepulcri CCM 7311T (97.5 % similarity). Growth was observed at 10-40 °C (optimum, 30 °C) and at pH 5.5-9.0 (optimum, pH 7.5). The DNA G+C content of strain P5-1T was 48.9 mol%. Cells contained menaquinone 7 (MK-7) as the sole respiratory quinone and the major fatty acids were anteiso-C15 : 0 and iso-C15 : 0. The cellular polar lipids comprised phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, one unidentified glycolipid and one unidentified aminophospholipid. The diamino acid of the cell-wall peptidoglycan was meso-diaminopimelic acid. Based on the phylogenetic, chemotaxonomic and phenotypic data obtained within this study, strain P5-1T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus nasutitermitis sp. nov. is proposed. The type strain is P5-1T ( = CGMCC 1.15178T = NBRC 111536T). PMID:26620554

  10. Moheibacter sediminis gen. nov., sp. nov., a member of the family Flavobacteriaceae isolated from sediment, and emended descriptions of Empedobacter brevis, Wautersiella falsenii and Weeksella virosa.

    PubMed

    Zhang, Ren-Gang; Tan, Xu; Zhao, Xing-Min; Deng, Jian; Lv, Jie

    2014-05-01

    A Gram-reaction-negative, yellow-pigmented, strictly aerobic bacterium, designated M0116T, was isolated from the sediment of the Mohe Basin in north-east China. Flexirubin-type pigments were produced. Cells were catalase- and oxidase-positive and non-gliding rods. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain M0116T was a member of the family Flavobacteriaceae and was most closely related to members of the genera Empedobacter, Wautersiella and Weeksella with 90.5-91.0% sequence similarities. The major cellular fatty acids were iso-C15:0 and iso-C17:0 3-OH. The major respiratory quinone was MK-6 and the major polar lipid was phosphatidylethanolamine. The DNA G+C content was 38.2 mol%. Based on phenotypic, phylogenetic and genotypic data, strain M0116T is considered to represent a novel species of a new genus in the family Flavobacteriaceae, for which the name Moheibacter sediminis gen. nov., sp. nov. is proposed. The type strain is M0116T (=CGMCC 1.12708T=JCM 19634T). Emended descriptions of Empedobacter brevis, Wautersiella falsenii and Weeksella virosa are also proposed. PMID:24453231

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

    PubMed

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

    2015-07-01

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

  12. Dyadobacter sediminis sp. nov., isolated from a subterranean sediment sample.

    PubMed

    Tian, Mu; Zhang, Ren-Gang; Han, Lu; Zhao, Xing-Min; Lv, Jie

    2015-03-01

    A Gram-reaction-negative, flexirubin-type-pigmented, rod-shaped, aerobic, non-motile bacterium, designated strain Z12(T), was isolated from a subsurface sediment sample. In a phylogenetic tree based on 16S rRNA gene sequences, strain Z12(T) formed a distinct clade with the members of the genus Dyadobacter (<96.7?% sequence similarity). The G+C content of genomic DNA was 45.4?%. The major fatty acids of strain Z12(T) were iso-C15?:?0, C16?:?1?6c and/or C16?:?1?7c (summed feature 3) and anteiso-C17?:?1 B and/or iso-C17?:?1 I (summed feature 4). The major respiratory quinone was MK-7 and the major polar lipid was phosphatidylethanolamine. On the basis of phenotypic, phylogenetic and genotypic features, strain Z12(T) is considered to represent a novel species, for which the name Dyadobacter sediminis sp. nov., is proposed. The type strain is Z12(T) (?=?JCM 30073(T)?=?CGMCC 1.12895(T)). PMID:25525123

  13. Nocardiopsis fildesensis sp. nov., an actinomycete isolated from soil.

    PubMed

    Xu, Shanshan; Yan, Lien; Zhang, Xuan; Wang, Chao; Feng, Ge; Li, Jing

    2014-01-01

    A filamentous actinomycete strain, designated GW9-2(T), was isolated from a soil sample collected from the Fildes Peninsula, King George Island, West Antarctica. The strain was identified using a polyphasic taxonomic approach. The strain grew slowly on most media tested, producing small amounts of aerial mycelia and no diffusible pigments on most media tested. The strain grew in the presence of 0-12?% (w/v) NaCl (optimum, 2-4?%), at pH 9.0-11.0 (optimum, pH 9.0) and 10-37 C (optimum, 28 C). The isolate contained meso-diaminopimelic acid, no diagnostic sugars and MK-9(H4) as the predominant menaquinone. The major phospholipids were phosphatidylglycerol, phosphatidylcholine and phosphatidylmethylethanolamine. The major fatty acids were iso-C16?:?0, anteiso-C17?:?0, C18?:?1?9c, iso-C15?:?0 and iso-C17?:?0. DNA-DNA relatedness was 37.6?% with Nocardiopsis lucentensis DSM 44048(T), the nearest phylogenetic relative (97.93?% 16S rRNA gene sequence similarity). On the basis of the results of a polyphasic study, a novel species, Nocardiopsis fildesensis sp. nov., is proposed. The type strain is GW9-2(T) (?=?CGMCC 4.7023(T)?=?DSM 45699(T)?=?NRRL B-24873(T)). PMID:24048863

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

    PubMed

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

    2012-10-01

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

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

    PubMed

    Luo, Guosheng; Shi, Zunji; Wang, Gejiao

    2012-07-01

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

  16. Sinomicrobium pectinilyticum sp. nov., a pectinase-producing bacterium isolated from alkaline and saline soil, and emended description of the genus Sinomicrobium.

    PubMed

    Cheng, Bin; Li, Chunfang; Lai, Qiliang; Du, Miaofen; Shao, Zongze; Xu, Ping; Yang, Chunyu

    2014-09-01

    A Gram-reaction-negative, non-spore-forming strain, designated 5DNS001(T), was isolated from soil of an ancient salt-extracting facility in China. Analysis of the almost-complete 16S rRNA gene sequence of the bacterium suggested that it belongs to the genus Sinomicrobium in the family Flavobacteriaceae. It exhibited highest 16S rRNA gene sequence similarity with Sinomicrobium oceani SCSIO 03483(T) (96.3?%), but less than 93?% sequence similarity with members of the genera Imtechella, Zhouia and Joostella and other recognized members of the family Flavobacteriaceae. The strain was able to hydrolyse pectin and starch by producing pectinase and ?-amylase. The DNA G+C content of the strain was 42.6 mol%. The major respiratory quinone was MK-6. The major polar lipid detected in the strain was phosphatidylethanolamine. The dominant cellular fatty acids were iso-C15?:?0, iso-C17?:?0 3-OH and summed feature 3 (C16?:?1?6c/C16?:?1?7c). Based on phenotypic, genotypic, chemotaxonomic and phylogenetic analyses, a novel species, Sinomicrobium pectinilyticum, is proposed. The type strain is 5DNS001(T) (?=?CGMCC1.11000(T)?=?KCTC23776(T)). PMID:24912822

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

    PubMed

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

    2015-07-01

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

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

    PubMed

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

    2015-07-01

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

  19. 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 15-40C and pH 5.0-10.0, with the optimum growth at 1% NaCl, 30-37C 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

  20. Fulvimarina manganoxydans sp. nov., isolated from a deep-sea hydrothermal plume in the south-west Indian Ocean.

    PubMed

    Ren, Fei; Zhang, Limin; Song, Lei; Xu, Shiyao; Xi, Lijun; Huang, Li; Huang, Ying; Dai, Xin

    2014-08-01

    An aerobic, Mn(II)-oxidizing, Gram-negative bacterium, strain 8047(T), was isolated from a deep-sea hydrothermal vent plume in the south-west Indian Ocean. The strain was rod-shaped and motile with a terminal flagellum, and formed yellowish colonies. It produced catalase and oxidase, hydrolysed gelatin and reduced nitrate. 16S rRNA gene sequence analysis showed that strain 8047(T) belonged to the order Rhizobiales of the class Alphaproteobacteria, and was phylogenetically most closely related to the genus Fulvimarina, sharing 94.4% sequence identity with the type strain of the type species. The taxonomic affiliation of strain 8047(T) was supported by phylogenetic analysis of four additional housekeeping genes, gyrB, recA, rpoC and rpoB. The predominant respiratory lipoquinone of strain 8047(T) was Q-10, the major fatty acid was C(18 : 1)ω7c and the DNA G+C content was 61.7 mol%. On the basis of the phenotypic and genotypic characteristics determined in this study, strain 8047(T) represents a novel species within the genus Fulvimarina, for which the name Fulvimarina manganoxydans sp. nov. is proposed. The type strain is strain 8047(T) ( = CGMCC1.10972(T) = JCM 18890(T)). PMID:24854008

  1. Janibacter indicus sp. nov., isolated from hydrothermal sediment of the Indian Ocean.

    PubMed

    Zhang, Gaiyun; Ren, Huihui; Wang, Shuang; Chen, Xiu; Yang, Yanliu; Zhang, Yubian; Jiang, Yi

    2014-07-01

    A Gram-staining-positive, aerobic and non-motile strain, 0704P10-1(T), was isolated from hydrothermal sediment of the Indian Ocean. Phylogenetic, phenotypic and chemotaxonomic data for the organism supported that it belonged to the genus Janibacter. Strain 0704P10-1(T) showed 97.2-98.7% 16S rRNA gene sequence similarities to the type strains of recognized members of the genus Janibacter. It contained meso-diaminopimelic acid as the diagnostic diamino acid in the cell wall. MK-8(H4) was the only menaquinone detected. The major fatty acids were iso-C16 : 0, C17 : 1ω8c and 10-methyl C17 : 0. Meanwhile, the results of DNA-DNA hybridization studies and other physiological and biochemical tests allowed the genotypic and phenotypic differentiation of strain 0704P10-1(T) from closely related species. Thus, strain 0704P10-1(T) represents a novel species of the genus Janibacter, for which the name Janibacter indicus sp. nov. is proposed. The type strain is 0704P10-1(T) ( = LMG 27493(T) = CGMCC 1.12511(T)). PMID:24744020

  2. Genomic Diversity and Evolution of Bacillus subtilis.

    PubMed

    Yu, Gang; Wang, Xun Cheng; Tian, Wang Hong; Shi, Ji Chun; Wang, Bin; Ye, Qiang; Dong, Si Guo; Zeng, Ming; Wang, Jun Zhi

    2015-08-01

    Bacillus subtilis is the focus of both academic and industrial research. Previous studies have reported a number of sequence variations in different B. subtilis strains. To uncover the genetic variation and evolutionary pressure in B. subtilis strains, we performed whole genome sequencing of two B. subtilis isolates, KM and CGMCC63528. Comparative genomic analyses of these two strains with other B. subtilis strains identified high sequence variations including large insertions, deletions and SNPs. Most SNPs in genes were synonymous and the average frequency of synonymous mutations was significantly higher than that of the non-synonymous mutations. Pan-genome analysis of B. subtilis strains showed that the core genome had lower dN/dS values than the accessory genome. Whole genome comparisons of these two isolates with other B. subtilis strains showed that strains in different subspecies have similar dN/dS values. Nucleotide diversity analysis showed that spizizenii subspecies have higher nucleotide diversity than subtilis subspecies. Our results indicate that genes in B. subtilis strains are under high purifying selection pressure. The evolutionary pressure in different subspecies of B. subtilis is complex. PMID:26383601

  3. Oceanobacillus bengalensis sp. nov., a bacterium isolated from seawater of the Bay of Bengal.

    PubMed

    Yongchang, Ouyang; Xiang, Wenzhou; Wang, Guanghua

    2015-11-01

    A Gram-stain positive, motile, and subterminal endospore-forming rod-shaped bacterium, designated strain Ma-21(T), was isolated from seawater of the Bay of Bengal. Strain Ma-21(T) was found to grow optimally at 37 C and pH 8.0 with 3% (w/v) NaCl. Phylogenetic analyses showed that strain Ma-21(T) forms a distinct phylogenetic lineage close to Oceanobacillus chungangensis CAU 1051(T), Oceanobacillus caeni S-11(T), Oceanobacillus arenosus CAU 1183(T), Oceanobacillus halophilum GD01(T) and Ornithinibacillus heyuanensis GIESS003(T) in the family Bacillaceae. The cell wall of strain Ma-21(T) was found to contain meso-diaminopimelic acid as the diagnostic diamino acid, which is in line with those of members of the genus Oceanobacillus. The genomic DNA G+C content was determined to be 35.9 mol%. The only respiratory quinone detected was MK-7. The major cellular fatty acids were identified as anteiso-C(15:0) and anteiso-C(17:0). The major polar lipids were found to be diphosphatidylglycerol and phosphatidylglycerol. On the basis of phylogenetic, chemotaxonomic and phenotypic properties, strain Ma-21(T) is suggested to represent a novel species in the genus Oceanobacillus, for which the name Oceanobacillus bengalensis sp. nov. is proposed. The type strain is Ma-21(T) (=CGMCC 1.12799(T) = KCTC 33416(T) = MCCC 1K00260(T)). PMID:26303283

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

    PubMed Central

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

    2013-01-01

    A borrelidin-producing actinomycete, designated strain NEAU-W2T, was isolated from the root surface of soybean [Glycine max (L.) Merr] and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of streptomycetes. The G+C content of the DNA was 66.12 mol%. Analysis of the 16S rRNA gene sequence of strain NEAU-W2T revealed that the strain formed a distinct clade within the 16S rRNA gene sequence phylogenetic tree and showed highest similarity (99.61?%) to Streptomyces neyagawaensis ATCC 27449T. However, the DNADNA relatedness between strain NEAU-W2T and S. neyagawaensis ATCC 27449T was 58.51?%. Strain NEAU-W2T could also be differentiated from S. neyagawaensis ATCC 27449T and other Streptomyces species showing high 16S rRNA gene sequence similarity (9899?%), as well as other borrelidin-producing strains, based on morphological and physiological characteristics. On the basis of its physiological and molecular properties, it is proposed that strain NEAU-W2T represents a novel Streptomyces species, Streptomyces heilongjiangensis sp. nov. The type strain is NEAU-W2T (?=?CGMCC 4.7004T ?=?ATCC BAA-2424T ?=?DSM 42073T). PMID:22707527

  5. Micromonospora polyrhachis sp. nov., an actinomycete isolated from edible Chinese black ant (Polyrhachis vicina Roger).

    PubMed

    Xiang, Wensheng; Yu, Chao; Liu, Chongxi; Zhao, Junwei; Yang, Lingyu; Xie, Binjiao; Li, Lei; Hong, Kui; Wang, Xiangjing

    2014-02-01

    A novel actinomycete, designated strain NEAU-ycm2(T), was isolated from edible Chinese black ants (Polyrhachis vicina Roger) and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of the genus Micromonospora. The 16S rRNA gene sequence of strain NEAU-ycm2(T) showed highest similarity to those of Micromonospora sonneratiae 274745(T) (99.12%), Micromonospora pattaloongensis TJ2-2(T) (98.85%), Micromonospora pisi GUI 15(T) (98.76%), Polymorphospora rubra TT 97-42(T) (98.42%) and Micromonospora eburnea LK2-10(T) (98.21%). Phylogenetic analysis based on the 16S rRNA gene and gyrB gene demonstrated that strain NEAU-ycm2(T) is a member of the genus Micromonospora and supported the close phylogenetic relationship to M. sonneratiae 274745(T), M. pattaloongensis JCM 12833(T) and M. pisi GUI 15(T). Furthermore, a combination of DNA-DNA hybridization and some physiological and biochemical properties indicated that the novel strain could be readily distinguished from its closest phylogenetic relatives. Therefore, it is proposed that NEAU-ycm2(T) represents a novel species of the genus of Micromonospora, for which the name Micromonospora polyrhachis sp. nov. is proposed. The type strain is NEAU-ycm2(T) (?=?CGMCC 4.7100(T)?=?DSM 45886(T)). PMID:24108323

  6. Streptomyces polyrhachii sp. nov., a novel actinomycete isolated from an edible Chinese black ant (Polyrhachis vicina Roger).

    PubMed

    Yu, Chao; Liu, Chongxi; Wang, Xiangjing; Zhao, Junwei; Yang, Lingyu; Gao, Ruixia; Zhang, Yuejing; Xiang, Wensheng

    2013-12-01

    A novel actinomycete, designated strain NEAU-ycm1(T), was isolated from an edible Chinese black ant (Polyrhachis vicina Roger) and characterized with a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of streptomycetes. Phylogenetic analysis based on the almost complete 16S rRNA gene sequence show that the novel isolate belongs to the genus Streptomyces and forms a separate subclade. The closest phylogenetic relatives were identified as the type strains of Streptomyces intermedius NBRC 13049(T) (97.74 %), Streptomyces aureoverticillatus NRRL B-3326(T) (97.69 %), Streptomyces rutgersensis NBRC 12819(T) (97.68 %), Streptomyces gougerotii NBRC 3198(T) (97.68 %) and Streptomyces diastaticus subsp. diastaticus NBRC 3714(T) (97.68 %). Similarities to other type strains of the genus Streptomyces were lower than 97.55 %. A comparison between strain NEAU-ycm1(T) and the closest related Streptomyces type strains revealed that it is different from them in morphological, physiological and biochemical characteristics. Therefore, it is proposed that NEAU-ycm1(T) (=CGMCC 4.7094(T) = DSM 42102(T)) represents a novel species of the genus of Streptomyces, for which the name Streptomyces polyrhachii sp. nov. is proposed. PMID:24002610

  7. Clostridium luticellarii sp. nov., isolated from a mud cellar used for producing strong aromatic liquors.

    PubMed

    Wang, Qian; Wang, Chuan-Dong; Li, Cheng-Hou; Li, Jun-Gang; Chen, Qi; Li, Yue-Zhong

    2015-12-01

    A strictly anaerobic, Gram-stain-positive bacterium, designated FW431T, was isolated from a mud cellar used for producing strong aromatic Chinese liquors. The strain was able to produce butanoic acid, an important component of the aroma style of Chinese liquors. Cells of strain FW431T were straight or slightly curved rods with a polar endospore and peritrichous flagella. The major cellular fatty acids (>10 % of the total) were C16 : 0, C18 : 1ω9c and C18 : 0. Biolog assays indicated that the strain preferably metabolizes palatinose, l-fucose, β-hydroxybutyric acid, l-rhamnose and α-ketobutyric acid among 95 carbon sources tested. FW431T was related most closely to Clostridium ljungdahlii DSM 13528T and Clostridium kluyveri DSM 555T based on 16S rRNA gene sequence similarities of 95.0 and 94.2 %, respectively. The DNA G+C content of the genomic DNA was 44.4 mol%. Based on the evidence presented here, FW431T ( = CGMCC 1.5201T = KCTC 15519T) is proposed as the type strain of a novel species, Clostridium luticellarii sp. nov. PMID:26420591

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

    PubMed

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

    2010-07-01

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

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

    PubMed

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

    2015-12-01

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

  10. Sphingomonas arantia sp. nov., isolated from Hoh Xil basin, China.

    PubMed

    Jia, Li; Zheng, Zhong; Feng, Xiaomin; Nogi, Yuichi; Yang, Aichen; Zhang, Yali; Han, Lu; Lu, Zhenquan; Lv, Jie

    2015-12-01

    A Gram-negative, rod-shaped, non-motile, non-spore forming, aerobic, orange-pigmented bacterium, designated strain 6P(T), was isolated from a soil sample collected from the Hoh Xil basin, China. Strain 6P(T) grew optimally at 25 °C, pH 7.0-7.5 and NaCl concentration of 0-1 % (w/v). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 6P(T) belongs to the genus Sphingomonas, with high sequence similarity (97.1 %) to Sphingomonas fennica. The DNA-DNA hybridization homology with S. fennica DSM 13665(T) was 45.3 %. The DNA G+C content of the novel strain is 65.3 mol%. The isolate contained Q-10 as the only respiratory quinone. The major polar lipids are diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylcholine (PC) and sphingoglycolipid (SGL). C18:1 ω7c and C16:1 ω7c are the major fatty acids. On the basis of the polyphasic evidence presented, strain 6P(T) represents a novel species of the genus Sphingomonas, for which the name Sphingomonas arantia sp. nov. is proposed. The type strain is 6P(T) (=CGMCC 1.12702(T) = JCM 19855(T)). PMID:26363912

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

    PubMed

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

    2015-09-01

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

  12. Paenibacillus shenyangensis sp. nov., a bioflocculant-producing species isolated from soil under a peach tree.

    PubMed

    Jiang, Binhui; Zhao, Xin; Liu, Jinliang; Fu, Lili; Yang, Chengcheng; Hu, Xiaomin

    2015-01-01

    A Gram-stain-positive, aerobic or facultatively anaerobic, rod-shaped, non-motile, endospore-forming bacterium, strain A9(T), was isolated in 1996 from a soil sample collected under a peach tree in Qingnian Park in Shenyang, PR China, and its taxonomic position was investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain belonged to the genus Paenibacillus, and was most closely related to the type strain of Paenibacillus hunanensis with a 16S rRNA gene sequence similarity of 96.7?% and a DNA-DNA relatedness value of 51.6?%. The major polar lipids of strain A9(T) were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant menaquinone was MK-7 and the major cellular fatty acids were anteiso-C15?:?0, C16?:?0 and iso-C15?:?0. The DNA G+C content was 51.9 mol%. Based on these results, it is concluded that strain A9(T) represents a novel species of the genus Paenibacillus, for which the name Paenibacillus shenyangensis sp. nov. is proposed, with A9(T) (?=?JCM 19307(T)?=?CGMCC 2040(T)) as the type strain. PMID:25323595

  13. Methanoculleus hydrogenitrophicus sp. nov., a methanogenic archaeon isolated from wetland soil.

    PubMed

    Tian, Jianqing; Wang, Yanfen; Dong, Xiuzhu

    2010-09-01

    An obligately anaerobic, methanogenic archaeon, strain HC(T), was isolated from soil of the Zoige wetland on the Tibetan plateau, China. The strain was isolated through construction of an artificial butyrate-degrading consortium in co-culture with a syntrophic bacterium, 'Syntrophomonas erecta subsp. sporosyntropha' JCM 13344. Cells of strain HC(T) were irregular coccoids, 0.8-2 mum in diameter, that occurred singly and utilized only H(2)/CO(2) for growth and methane production. Growth occurred at 18-45 degrees C (optimum around 37 degrees C). The pH for growth was 5.0-8.5 (optimal growth around pH 6.6). The G+C content of the genomic DNA was 60.2 mol%. 16S rRNA gene sequence analysis indicated that strain HC(T) was affiliated to the genus Methanoculleus, with sequence similarities of 94.8-97.2 % to existing members. However, strain HC(T) was distinguished from described Methanoculleus species by not using formate for growth or methane formation and not requiring acetate as a growth factor. On the basis of phylogenetic analysis and phenotypic characteristics, the novel species Methanoculleus hydrogenitrophicus sp. nov. is proposed, with strain HC(T) (=CGMCC 1.5146(T) =JCM 16311(T)) as the type strain. PMID:19897615

  14. Seohaeicola westpacificensis sp. nov., a novel member of genera Seohaeicola isolated from deep West Pacific Sea water.

    PubMed

    Xian, Shuhui; Zhang, Rui; Sun, Jia; Chen, Yi; Deng, Wenchao; Li, Shuhui; Jiao, Nianzhi

    2014-07-01

    Strain JL2247(T), an aerobic, Gram-negative, gliding motile bacterium, was isolated from the western Pacific at the depth of 2,000 m. The cell was spindle-shaped with two narrow poles, and flagella were not observed. The colony was circular, translucent, and milky. This strain showed catalase-positive and oxidase-negative reactions. Its optimal growth conditions were at 32 C, pH 7.3, and 3 % NaCl. The predominant polar lipids were phosphatidylcholine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and phosphatidylmonomethylethanolamine. The major fatty acids were summed feature 8 (18:1 w7c and/or 18:1 w6c) and Cyclo C19:0 ?8c and the major respiratory quinone was Q-10. The DNA G+C content of strain JL2247(T) was 72.6 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain JL2247(T) fell into the genus Seohaeicola, family Rhodobacteraceae, order Rhodobacterales, class Alphaproteobacteria, sharing the highest similarity with the only species Seohaeicola saemankumensis SD-15(T) (96.4 % similarity). From the phenotypic, genotypic, and chemotaxonomic data, strain JL2247(T) represents a novel species of the genus Seohaeicola and the name is proposed as Seohaeicola westpacificensis sp. nov. The type strain is JL2247(T) (=CGMCC 1.12198(T) = JCM18883). PMID:24585075

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

    PubMed

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

    2015-06-01

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

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

    PubMed

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

    2016-03-01

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

  17. Hymenobacter qilianensis sp. nov., isolated from a subsurface sandstone sediment in the permafrost region of Qilian Mountains, China and emended description of the genus Hymenobacter.

    PubMed

    Han, Lu; Wu, Shu-Jiao; Qin, Chun-Yan; Zhu, You-Hai; Lu, Zhen-Quan; Xie, Bing; Lv, Jie

    2014-05-01

    A red-pink, Gram-negative, rod-shaped, non-motile, non-spore-forming bacterium, designated strain DK6-37 was isolated from the permafrost region of Qilian Mountains in northwest of China. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that this isolate represents a novel member of the genus Hymenobacter, with low sequence similarities (<97%) to recognized Hymenobacter species. Optimum growth was observed at 28C, pH 7.0 and 0% NaCl. The strain was found to contain MK-7 as the predominant menaquinone. The polar lipids were identified as phosphatidylethanolanmine, two unknown aminophospholipids, one unknown aminolipid and three unknown polar lipids. The major fatty acids were identified as summed feature 3 (C16:1 ?7c/C16:1 ?6c as defined by MIDI), summed feature 4 (anteiso-C17:1 B/iso-C17:1 I), C16:1 ?5c, iso-C17:0 3-OH, iso-C15:0 and C18:0. The DNA G+C content was determined to be 67.4mol%. On the basis of the polyphasic evidence presented, it is proposed that strain DK6-37 represents a novel species of the genus Hymenobacter, for which the name Hymenobacter qilianensis sp. nov. is proposed. The type strain is DK6-37(T) (=CGMCC 1.12720(T)=JCM 19763(T)). PMID:24677143

  18. Pyruvatibacter mobilis gen. nov., sp. nov., a marine bacterium from the culture broth of Picochlorum sp. 122.

    PubMed

    Wang, Guanghua; Tang, Mingxing; Wu, Hualian; Dai, Shikun; Li, Tao; Chen, Chenghao; He, Hui; Fan, Jiewei; Xiang, Wenzhou; Li, Xiang

    2016-01-01

    A Gram-stain-negative, aerobic bacterium, designated strain GYP-11T, was isolated from the culture broth of a marine microalga, Picochloruma sp. 122. Cells were dimorphic rods; free living cells were motile by means of a single polar flagellum, and star-shaped-aggregate-forming cells were attached with stalks and non-motile. Sodium pyruvate or Tween 20 was required for growth on marine agar 2216.16S rRNA gene sequence analysis revealed that this isolate shared 94.07?% similarity with its closest type strain, Parvibaculum hydrocarboniclasticum EPR92T. Phylogenetic analyses indicated that strain GYP-11T represents a distinct lineage in a robust clade consisting of strain GYP-11T, alphaproteobacterium GMD21A06 and Candidatus Phaeomarinobacter ectocarpi Ec32. This clade was close to the genera Parvibaculum and Tepidicaulis in the order Rhizobiales. Chemotaxonomic and physiological characteristics, including cellular fatty acids and carbon source profiles, also readily distinguished strain GYP-11T from all established genera and species. Thus, it is concluded that strain GYP-11T represents a novel species of a new genus in the order Rhizobiales, for which the name Pyruvatibacter mobilis gen. nov., sp. nov. is proposed. The type strain of Pyruvatibacter mobilis is GYP-11T (?=?CGMCC 1.15125T?=?KCTC 42509T). PMID:26476620

  19. Performance of a new thermostable mannanase in breaking guar-based fracturing fluids at high temperatures with little premature degradation.

    PubMed

    Hu, Ke; Li, Chun-Xiu; Pan, Jiang; Ni, Yan; Zhang, Xiao-Yan; Xu, Jian-He

    2014-02-01

    A new thermostable ?-1,4-mannanase (DtManB) cloned from Dictyoglomus thermophilum CGMCC 7283 showed the maximum activity towards hydroxypropyl guar gum at 80 C, with a half-life of 46 h. DtManB exhibited good compatibility with various additives of fracturing fluid, retaining more than 50 % activity in all the cases tested. More importantly, premature degradation could be alleviated significantly when using DtManB as breaker, because at 27 and 50 C it displayed merely 3.7 and 18.5 % activities compared to those at 80 C. In a static test, 0.48 mg DtManB could break 200 mL borax cross-linked fracturing fluid dramatically at 80 C, and merely 18 mPa s of the viscosity was detected even after the broken fluid was cooled down and only 161.4 mg L(-1) of the residue was left after the enzymatic reaction. All these positive features demonstrate the great potential of this mannanase as a new enzyme breaker for application in enhanced recovery of petroleum oil. PMID:24150905

  20. Massilia eurypsychrophila sp. nov. a facultatively psychrophilic bacteria isolated from ice core.

    PubMed

    Shen, Liang; Liu, Yongqin; Gu, Zhengquan; Xu, Baiqing; Wang, Ninglian; Jiao, Nianzhi; Liu, Hongcan; Zhou, Yuguang

    2015-07-01

    Strain B528-3(T), a Gram-stain-negative, rod-shaped, aerobic, facultatively psychrophilic bacterium with polar flagella, was isolated from an ice core drilled from Muztagh Glacier, Xinjiang, China. The novel isolate was classified into the genus Massilia. The 16S rRNA gene sequence of the novel isolate shares a pairwise similarity of less than 97% with those of all the type strains of the genus Massilia. The major fatty acids of strain B528-3(T) were summed feature 3 (C16:1?7c and/or iso-C15:0 2-OH) (57.31%), C16:0 (11.46%) and C18:1?7c (14.72%). The predominant isoprenoid quinone was Q-8. The DNA G + C content was 62.2 mol% (Tm). The major polar lipids of this bacterium were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. From the genotypic and phenotypic data, it is evident that strain B528-3(T) represents a novel species of the genus Massilia, for which the name Massilia eurypsychrophila sp. nov. is proposed. The type strain is B528-3(T) (?= JCM 30074(T) = CGMCC 1.12828(T)). PMID:25851590

  1. Thermus arciformis sp. nov., a thermophilic species from a geothermal area.

    PubMed

    Zhang, Xin-Qi; Ying, Yi; Ye, Ying; Xu, Xue-Wei; Zhu, Xu-Fen; Wu, Min

    2010-04-01

    Two aerobic, Gram-negative, non-motile, non-sporulating, yellow-pigmented bacteria, strains TH92(T) and TH91, were isolated from a hot spring located in Laibin, Guangxi, in the south-eastern geothermal area of China. The isolates grew at 40-77 degrees C (optimally at 70 degrees C) and at pH 6.0-9.5 (optimally at pH 7.5-8.0). Phylogenetic analysis of 16S rRNA gene sequences and levels of DNA-DNA relatedness together indicated that the new isolates represented a novel species of the genus Thermus with closest affinity to Thermus aquaticus, Thermus igniterrae and Thermus thermophilus. Compared with their closest relatives, strains TH92( T) and TH91 were able to assimilate a wider range of carbohydrates, amino acids and organic acids as sole carbon sources for growth, such as lactose and melibiose. The new isolates had lower combined levels of C(16 : 0 ) and iso-C(16 : 0) compared with their closest relatives. On the basis of polyphasic taxonomic characterization, strains TH92(T) and TH91 are considered to represent a single novel species of the genus Thermus, for which the name Thermus arciformis sp. nov. is proposed. The type strain is TH92(T) (=CGMCC 1.6992(T) =JCM 15153(T)). PMID:19661520

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

    PubMed

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

    2015-07-01

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

  3. Wastewater irrigation increases the abundance of potentially harmful gammaproteobacteria in soils in Mezquital Valley, Mexico.

    PubMed

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

    2014-09-01

    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

  4. 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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

    Background and Objective: Antibiotic resistance is increasing, especially in healthcare-associated infections causing significant public health concerns worldwide. National information is required to make appropriate policies, update list of essential drugs for treatment, and evaluate the effects of intervention strategies. A nationwide surveillance of antimicrobial resistant bacteria in nosocomial infections was established in Iran in 2008, so that the data obtained through the surveillance would enable us to construct a database. Materials and Methods: Seven major teaching hospitals in Shiraz, Tabriz, Sari, Mashhad, Sanandaj, Ahwaz and Isfahan participated in this study. A total of 858 strains isolated from blood and other sterile body fluids were tested. Identification at the species level was performed with conventional biochemical methods and the API system. Susceptibility tests were done using disk diffusion method. The methicillin-resistance in S. aureus (MRSA) was determined by the oxacillin agar screen plate and respective MIC values were assessed using the E-test strips. The confirmatory disk diffusion methods were applied for phenotypic identification of ext