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1

Biotransformation of thianicotinyl neonicotinoid insecticides: diverse molecular substituents response to metabolism by bacterium Stenotrophomonas maltophilia CGMCC 1.1788.  

PubMed

The carbon atom that neighbors the tertiary amine attached to the 6-chloro-3-pyridinylmethyl moiety is the key active site in the hydroxylation of the neonicotinoids imidacloprid and thiacloprid as well as in the demethylation of acetamiprid by Stenotrophomonas maltophilia CGMCC 1.1788. In this study, thianicotinyl neonicotinoid insecticides having diverse molecular substituents were biotransformed by S. maltophilia CGMCC 1.1788. The results indicated that the substitution of 6-chloropyridyl in imidacloprid with 2-chlorothiazol in imidaclothiz did not affect the hydroxylation of imidaclothiz and its hydroxylated site, while the oxadiazinane ring in thiamethoxam was not hydroxylated or opened. Moreover, the N-methyl group in clothianidin and thiamethoxam was not demethylated by S. maltophilia CGMCC 1.1788. The biotransformation of imidaclothiz was inhibited by piperonyl butoxide, implying that both hydroxylation and dehydrogenation are mediated by a P450 monooxygenase. The bioassay results suggested that the activity of 5-hydroxy and olefin imidaclothiz was similar but less than that of imidaclothiz against the horsebean aphid Aphis craccivora and mosquito larva Culex pipiens, while 5-hydroxy IMT showed weak activity against the brown planthopper Nilaparvata lugens. PMID:20149644

Dai, Yijun; Zhao, Yinjuan; Zhang, Wenjian; Yu, Cigang; Ji, Weiwei; Xu, Wenping; Ni, Jueping; Yuan, Sheng

2010-06-01

2

Stenotrophomonas maltophilia: an Emerging Global Opportunistic Pathogen  

PubMed Central

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.

2012-01-01

3

A new selective differential medium for isolation of Stenotrophomonas maltophilia  

Microsoft Academic Search

A new selective differential medium for the isolation ofStenotrophomonas (formerlyXanthomonas) maltophilia was developed. The medium, VIA agar, contained vancomycin, imipenem, and amphotericin B as selective agents and incorporated a mannitol\\/bromothymol blue indicator system. Compared withXanthomonas maltophilia Selective Medium (XMSM), VIA agar was less inhibitory toStenotrophomonas maltophilia and was more selective than XMSM in preventing the growth of unwanted bacteria from

K. G. Kerr; M. Denton; N. Todd; C. M. Corps; P. Kumari; P. M. Hawkey

1996-01-01

4

Heavy Metal Tolerance in Stenotrophomonas maltophilia  

PubMed Central

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.

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

2008-01-01

5

Community-acquired Stenotrophomonas maltophilia infections: a systematic review  

Microsoft Academic Search

Stenotrophomonas maltophilia is a pathogen that causes infections mainly in immunocompromised patients. However, community-acquired S. maltophilia infections have been occasionally reported. The objective of this paper was to collect and evaluate the available published\\u000a data referring to community-acquired S. maltophilia infections. We searched PubMed, the Cochrane Library, and Scopus for articles providing data for patients with community-acquired\\u000a S. maltophilia infections.

M. E. Falagas; A. C. Kastoris; E. K. Vouloumanou; G. Dimopoulos

2009-01-01

6

Liver abscess caused by Stenotrophomonas maltophilia: report of a case.  

PubMed

We report the case of a melioidosis-like abscess of the liver caused by Stenotrophomonas (Xanthomonas) maltophilia infection in a Chinese man living in Hungary. Although this appears to be the first documentation of a liver abscess of this origin in a nonimmunocompromised patient, our case report demonstrates that this common facultative pathogen can also cause liver abscess and sepsis. After repeated negative blood cultures, histological examinations of liver biopsies suggested the possibility of chronic melioidosis, but the microbiological examination performed directly on the same specimen identified a Stenotrophomonas maltophilia infection. Surgical drainage was performed and sulphamethoxazole/trimethoprim therapy was commenced, after which the patient recovered fully. The facultative pathogen S. maltophilia, which most often causes nosocomial infections, may cause severe sepsis and liver abscess. We wish to draw attention to the fact that the antibiotic sensitivity of S. maltophilia is not necessarily the same in vivo and in vitro. This can create difficulties in both diagnosis and treatment. PMID:12658392

Petri, András; Tiszlavicz, László; Nagy, Erzsébet; Morvay, Zita; Kókai, Erzsébet László; Savanya, Gábor Kocsis; Balogh, Adám

2003-01-01

7

Comparative in vitro activity of quinolones against Stenotrophomonas maltophilia.  

PubMed

The susceptibility of 109 Stenotrophomonas maltophilia isolates, all characterized by pulsed-field gel electrophoresis, to nine quinolones was studied. Grepafloxacin, trovafloxacin, and moxifloxacin displayed similar intrinsic activities (MIC90, 0.5 microg/ml), which were lower than those of ofloxacin and ciprofloxacin (MIC90, 4 microg/ml), norfloxacin (MIC90, 64 microg/ml), and nalidixic acid (MIC90, 32 microg/ml). Nalidixic acid was generally one- to twofold dilutions more active than norfloxacin. According to the criteria of the National Committee for Clinical Laboratory Standards (NCCLS), the percentage of isolates susceptible to ciprofloxacin (breakpoint < or = 1 microg/ml) was 76.1%. Using the NCCLS breakpoint for comparative purposes, the percentage of isolates susceptible to grepafloxacin, moxifloxacin, and trovafloxacin was 95.4, 96.4, and 96.4%, respectively. These results indicate that new quinolones may potentially be used for the management of Stenotrophomonas maltophilia infections. PMID:10691206

Valdezate, S; Vindel, A; Baquero, F; Cantón, R

1999-12-01

8

Liver Abscess Caused by Stenotrophomonas maltophilia : Report of a Case  

Microsoft Academic Search

.  \\u000a We report the case of a melioidosis-like abscess of the liver caused by Stenotrophomonas (Xanthomonas) maltophilia infection in a Chinese man living in Hungary. Although this appears to be the first documentation of a liver abscess of this\\u000a origin in a nonimmunocompromised patient, our case report demonstrates that this common facultative pathogen can also cause\\u000a liver abscess and sepsis.

András Petri; László Tiszlavicz; Erzsébet Nagy; Zita Morvay; Erzsébet László Kókai; Gábor Kocsis Savanya; Ádám Balogh

2003-01-01

9

Smqnr VARIANTS IN CLINICAL ISOLATES OF Stenotrophomonas maltophilia IN BRAZIL  

PubMed Central

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

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

2013-01-01

10

Microbiological and Clinical Aspects of Infection Associated with Stenotrophomonas maltophilia  

PubMed Central

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.

Denton, Miles; Kerr, Kevin G.

1998-01-01

11

Antimicrobial Susceptibilities of Unique Stenotrophomonas maltophilia Clinical Strains  

PubMed Central

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

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

2001-01-01

12

Antimicrobial susceptibilities of unique Stenotrophomonas maltophilia clinical strains.  

PubMed

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

Valdezate, S; Vindel, A; Loza, E; Baquero, F; Cantón, R

2001-05-01

13

Stenotrophomonas maltophilia endophthalmitis following cataract surgery: clinical and microbiological results  

PubMed Central

Background Stenotrophomonas maltophilia is a Gram-negative organism known to cause opportunistic infections. It is a rare source of endophthalmitis, often in the setting of trauma, but has been reported following cataract extraction. The purpose of this study was to evaluate antimicrobial sensitivities, clinical characteristics, and treatment outcomes in patients with endophthalmitis caused by S. maltophilia following cataract extraction. Methods A retrospective case review of records from January 1, 1990 to June 30, 2010 was performed at the Bascom Palmer Eye Institute. Results Eight cases of S. maltophilia endophthalmitis were identified following cataract surgery. Initial visual acuity ranged from 20/200 to light perception. Time to diagnosis with cultures was 2–118 days. Patients received either intravitreal tap and inject (n = 5) or pars plana vitrectomy with intravitreal antibiotic injections (n = 3). All patients had vitreous or anterior chamber cultures positive for S. maltophilia. Seven of seven isolates tested were found to be sensitive to ceftazidime. Seven of eight isolates were sensitive to polymyxin B, six of eight isolates were sensitive to amikacin, and five of the seven isolates tested were sensitive to ciprofloxacin. Two of four tested isolates were sensitive to trimethoprim-sulbactam. All eight isolates were resistant to gentamicin and seven of the seven tested isolates were resistant to imipenem. All patients received intravitreal ceftazidime as part of the initial treatment regimen. Final visual acuity ranged from 20/25 to 4/200. Conclusion S. maltophilia endophthalmitis is a rare source of endophthalmitis following cataract surgery. A case series of eight independent patients is reported, along with antibiotic resistance profiles and clinical outcomes. Isolates showed sensitivity to ceftazidime, amikacin, and polymyxin, with variable sensitivity to other antibiotics, therefore differing from previous reports.

Chang, Jonathan S; Flynn, Harry W; Miller, Darlene; Smiddy, William E

2013-01-01

14

Multiple degradation pathways of phenanthrene by Stenotrophomonas maltophilia C6.  

PubMed

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

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

2013-04-01

15

Multiple degradation pathways of phenanthrene by Stenotrophomonas maltophilia C6  

PubMed Central

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.

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

2013-01-01

16

Antifungal activity of Stenotrophomonas maltophilia in Stomoxys calcitrans larvae.  

PubMed

The microbiota present in Stomoxys calcitrans larvae may assist their survival in contaminated environments through production of inhibitory substances. Bacteriological identification methods, the polymerase chain reaction (PCR) and scanning electron microscopy (SEM) were used to detect a bacterium naturally present in mucus and macerated S. calcitrans larvae. The antifungal activity was determined based on the results from disk diffusion tests on an artificial solid medium. The bacterium was identified as Stenotrophomonas maltophilia and presented antifungal activity against Beauveria bassiana sensu lato isolates CG 138, CG 228 and ESALQ 986. This result suggests that the larval microbiota is a factor that can compromise the use of B. bassiana s.l. fungus for biological control of S. calcitrans larvae. PMID:25054498

Moraes, Ana Paula Rodrigues; Videira, Sandy Sampaio; Bittencourt, Vânia Rita Elias Pinheiro; Bittencourt, Avelino José

2014-04-01

17

Molecular characterization of 2-chlorobiphenyl degrading Stenotrophomonas maltophilia GS-103.  

PubMed

The catabolic potential of transformer oil contaminated soil bacteria in aerobic degradation of polychlorinated biphenyls (PCB) were assessed. Transformer oil contaminated soil sample was subjected to microcosm enrichment experiments (PAS medium/biphenyl as sole carbon source). PCB-degrading activity of the enrichment cultures in PAS medium with the addition of 2-chlorobiphenyl were analysed by GC-MS indicated that, although the isolates differed in PCB-degrading capabilities, all of the enrichment cultures expressed activity toward at least some of the lower chlorinated congeners. Biphenyl-utilizing bacteria isolated from the most active PCB-degrading mixed cultures showed little taxonomic diversity and identified as Stenotrophomonas maltophilia GS-103. PMID:23801320

Somaraja, P K; Gayathri, D; Ramaiah, N

2013-08-01

18

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

PubMed

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

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

2014-01-01

19

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

PubMed Central

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.

Huedo, Pol; Conchillo-Sole, Oscar; Yero, Daniel; Martinez-Servat, Sonia

2014-01-01

20

Antimicrobial Susceptibility of Stenotrophomonas maltophilia Isolates from a Korean Tertiary Care Hospital  

PubMed Central

We determined the antimicrobial susceptibility of 90 clinical isolates of Stenotrophomonas maltophilia collected in 2009 at a tertiary care hospital in Korea. Trimethoprim-sulfamethoxazole, minocycline, and levofloxacin were active against most of the isolates tested. Moxifloxacin and tigecycline were also active and hold promise as therapeutic options for S. maltophilia infections.

Chung, Hae-Sun; Hong, Seong Geun; Lee, Yangsoon; Kim, Myungsook; Yong, Dongeun; Jeong, Seok Hoon; Chong, Yunsop

2012-01-01

21

Stenotrophomonas maltophilia fimbrin stimulates mouse bladder innate immune response.  

PubMed

The role of Stenotrophomonas maltophilia fimbrin (SMF) to stimulate the bladder innate immune response was evaluated in this study. SMF was isolated and purified from clinical isolates of S .maltophilia. Different amounts of SMF (1, 5 and 15 ?g) was instilled transurethrally. The innate immune response was evaluated in terms of IL-1?, TNF-?, IL-8 and NO concentrations, and mRNA expressions of IL-1?, TNF-?, IL-8 and iNOS in mouse bladder tissue. Moreover, neutrophil infiltration in urine, myeloperoxidase (MPO) activity in bladder tissue and bladder epithelial cells (BECs) activity to engulf and kill bacteria in vitro was studied. The maximum pro-inflammatory cytokines (IL-1? and TNF-?) and chemokine (IL-8) concentrations and their mRNA expressions were found in bladder homogenates of mice that were instilled with 15 ?g of SMF transurethrally. The high levels of these mediators was concomitant with the high level of neutrophil infiltration in bladder tissue (MPO) and in collected urine (neutrophil count). The administration of SMF transurethrally activated the BECs in terms of bacterial uptake and intracellular bacterial killing in vitro. This study showed that the SMF administration increased the level of nitric oxide (NO) in bladder tissue. The present study proved for the first time that the administration of mice with SMF transurethrally induced cellular and molecular elements of innate immune response in mouse bladder. PMID:22910808

Zgair, A K; Al-Adressi, A M H

2013-01-01

22

Biofilm Compared to Conventional Antimicrobial Susceptibility of Stenotrophomonas maltophilia Isolates from Cystic Fibrosis Patients  

PubMed Central

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

Wu, Kitty; Yau, Yvonne C. W.; Matukas, Larissa

2013-01-01

23

Stenotrophomonas maltophilia infection during allogeneic hematopoietic stem cell transplantation: a single-center experience.  

PubMed

To examine risk factors for Stenotrophomonas maltophilia (S. maltophilia) infection during allogeneic hematopoietic stem cell transplantation (allo-HSCT), we retrospectively analyzed 259 patients who underwent allo-HSCT. Not only S. maltophilia infection but also S. maltophilia colonization was associated with mortality during allo-HSCT. Among 52 episodes in 39 patients in whom S. maltophilia was detected, documented infection developed in 33 episodes (25 patients). The onset of S. maltophilia infection in the period from the conditioning regimen to engraftment was associated with a high mortality rate. Breakthrough S. maltophilia infection developed in 24% of the patients during prophylactic administration of fluoroquinolones, to which S. maltophilia is sensitive. Reinsertion of a central venous catheter (CVC) immediately after removal was suggested to be a risk for persistent S. maltophilia infection in the period of neutropenia. Our results indicated that (i) onset of S. maltophilia infection in the period from the conditioning therapy to engraftment and (ii) removal and immediate reinsertion of a CVC as treatment after the onset of S. maltophilia infection are possible risk factors for S. maltophilia-related mortality during allo-HSCT. PMID:24628242

Shiratori, Souichi; Wakasa, Kentaro; Okada, Kohei; Sugita, Junichi; Akizawa, Koji; Shigematsu, Akio; Hashimoto, Daigo; Fujimoto, Katsuya; Endo, Tomoyuki; Kondo, Takeshi; Shimizu, Chikara; Hashino, Satoshi; Teshima, Takanori

2014-06-01

24

Chitinase A from Stenotrophomonas maltophilia shows transglycosylation and antifungal activities.  

PubMed

Stenotrophomonas maltophilia chitinase (StmChiA and StmChiB) genes were cloned and expressed as soluble proteins of 70.5 and 41.6 kDa in Escherichia coli. Ni-NTA affinity purified StmChiA and StmChiB were optimally active at pH 5.0 and 7.0, respectively and exhibited broad range pH activity. StmChiA and StmChiB had an optimum temperature of 40°C and are stable up to 50 and 40°C, respectively. Hydrolytic activity on chitooligosaccharides indicated that StmChiA was an endo-acting enzyme releasing chitobiose and StmChiB was both exo/endo-acting enzyme with the release of GlcNAc as the final product. StmChiA showed higher preference to ?-chitin and exhibited transglycosylation on even chain length tetra- and hexameric substrates. StmChiA, and not StmChiB, was active on chitinous polymers and showed antifungal activity against Fusarium oxysporum. PMID:23428818

Suma, Katta; Podile, Appa Rao

2013-04-01

25

Comparison of Two Multimetal Resistant Bacterial Strains: Enterobacter sp. YSU and Stenotrophomonas maltophilia ORO2  

Microsoft Academic Search

The Y-12 plant in Oak Ridge, TN, which manufactured nuclear weapons during World War II and the Cold War, contaminated East\\u000a Fork Poplar Creek with heavy metals. The multimetal resistant bacterial strain, Stenotrophomonas maltophilia Oak Ridge strain O2 (S. maltophilia O2), was isolated from East Fork Poplar Creek. Sequence analysis of 16s rDNA suggested that our working strain of S.

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

2009-01-01

26

Enhanced Degradation of TNT by Genome-Shuffled Stenotrophomonas maltophilia OK5  

Microsoft Academic Search

In this study, the enhanced degradation of TNT using cultures of genome-shuffled Stenotrophomonas maltophilia OK-5 mt-3 has been examined and the proteome of shuffled strain was compared to the wild-type OK-5 strain. Genome shuffling\\u000a of S. maltophilia OK-5 was used to achieve a rapid enhancement of TNT degradation. The initial mutant population was generated by NTG treatment\\u000a and UV irradiation.

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

2009-01-01

27

Can Levofloxacin Be a Useful Alternative to Trimethoprim-Sulfamethoxazole for Treating Stenotrophomonas maltophilia Bacteremia?  

PubMed Central

A retrospective study was conducted to evaluate the efficacy of levofloxacin in the treatment of Stenotrophomonas maltophilia bacteremia. The 30-day mortality rates were similar between the trimerthoprim-sulfamethoxazole (TMP-SMX) and levofloxacin treatment groups. Adverse events related to antibiotics occurred more frequently in patients receiving TMP-SMX, and recurrent bacteremia due to levofloxacin-resistant S. maltophilia strains developed in patients treated with levofloxacin. Our data suggest that levofloxacin can be a useful alternative option for treating S. maltophilia infections.

Cho, Sun Young; Kim, Jungok; Ha, Young Eun; Chung, Doo Ryeon; Lee, Nam Yong; Peck, Kyong Ran; Song, Jae-Hoon

2014-01-01

28

New strategies against Stenotrophomonas maltophilia: a serious worldwide intrinsically drug-resistant opportunistic pathogen.  

PubMed

Stenotrophomonas maltophilia is a worldwide human opportunistic pathogen associated with serious infections in humans, and is most often recovered from respiratory tract infections. In addition to its intrinsic drug resistance, this organism may acquire resistance via multiple molecular mechanisms. New antimicrobial strategies are needed to combat S. maltophilia infections, particularly in immunocompromised patients, cystic fibrosis patients with polymicrobial infections of the lung, and in patients with chronic infections. This editorial reports on newer drugs and antimicrobial strategies and their potential for use in treatment of S. maltophilia infections, the development of new technologies to detect this organism, and identifies strategies currently in use to reduce transmission of this pathogen. PMID:24308713

Brooke, Joanna S

2014-01-01

29

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

PubMed

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

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

2001-01-01

30

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

PubMed Central

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

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

2001-01-01

31

A Stenotrophomonas maltophilia Multilocus Sequence Typing Scheme for Inferring Population Structure  

Microsoft Academic Search

Stenotrophomonas maltophilia is an opportunistic, highly resistant, and ubiquitous pathogen. Strains have been assigned to genogroups using amplified fragment length polymorphism. Hence, isolates of environmental and clinical origin predominate in different groups. A multilocus sequence typing (MLST) scheme was developed using a highly diverse selection of 70 strains of various ecological origins from seven countries on all continents including strains

Sabine Kaiser; Klaus Biehler; Daniel Jonas

2009-01-01

32

Differential Biofilm Formation and Motility Associated with Lipopolysaccharide\\/Exopolysaccharide-Coupled Biosynthetic Genes in Stenotrophomonas maltophilia  

Microsoft Academic Search

Microorganisms can develop biofilms or clogging mats, caus- ing the failure of septic tanks, systems for on-site wastewater disposal. If water in these clogged systems were contaminated by pathogens, it would pose a threat to human health. We isolated Stenotrophomonas maltophilia strain WR-C from a clogged septic tank system that consistently formed biofilms on sand grains, produced exopolysaccharides (EPS), and

Tzu-Pi Huang; Eileen B. Somers; Amy C. Lee Wong

2006-01-01

33

Complicated features in a young child with influenza B virus pneumonia and co-infection with Stenotrophomonas maltophilia.  

PubMed

A 3.5-year-old child with influenza B virus pneumonia developed pneumomediastinum and subcutaneous emphysema on the 3rd day of illness. Bronchoscopy demonstrated obstruction of the left main bronchus by mucopurulent sputum. Culture of the broncho-alveolar lavage yielded Stenotrophomonas maltophilia. After the respiratory complications resolved (11 days), the patient developed neurological symptoms and was diagnosed as acute disseminated encephalomyelitis (ADEM). Stenotrophomonas maltophilia was probably a factor in the development of pneumomediastinum. To our knowledge, this is the first case report of influenza virus infection with Stenotrophomonas maltophilia co-infection associated with spontaneous pneumomediastinum. PMID:21575322

Chen, S-H; Huang, I-A; Wu, C-T; Hsia, S-H; Hung, P-C; Chiu, C-H

2011-01-01

34

Functional Characterization of the RNA Chaperone Hfq in the Opportunistic Human Pathogen Stenotrophomonas maltophilia  

PubMed Central

Hfq is an RNA-binding protein known to regulate a variety of cellular processes by interacting with small RNAs (sRNAs) and mRNAs in prokaryotes. Stenotrophomonas maltophilia is an important opportunistic pathogen affecting primarily hospitalized and immunocompromised hosts. We constructed an hfq deletion mutant (?hfq) of S. maltophilia and compared the behaviors of wild-type and ?hfq S. maltophilia cells in a variety of assays. This revealed that S. maltophilia Hfq plays a role in biofilm formation and cell motility, as well as susceptibility to antimicrobial agents. Moreover, Hfq is crucial for adhesion to bronchial epithelial cells and is required for the replication of S. maltophilia in macrophages. Differential RNA sequencing analysis (dRNA-seq) of RNA isolated from S. maltophilia wild-type and ?hfq strains showed that Hfq regulates the expression of genes encoding flagellar and fimbrial components, transmembrane proteins, and enzymes involved in different metabolic pathways. Moreover, we analyzed the expression of several sRNAs identified by dRNA-seq in wild-type and ?hfq S. maltophilia cells grown in different conditions on Northern blots. The accumulation of two sRNAs was strongly reduced in the absence of Hfq. Furthermore, based on our dRNA-seq analysis we provide a genome-wide map of transcriptional start sites in S. maltophilia.

Roscetto, Emanuela; Angrisano, Tiziana; Costa, Valerio; Casalino, Mariassunta; Forstner, Konrad U.; Sharma, Cynthia M.; Di Nocera, Pier Paolo

2012-01-01

35

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

PubMed

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

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

2014-06-01

36

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

PubMed Central

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.

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

2014-01-01

37

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

PubMed Central

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.

2014-01-01

38

Expression of Sme Efflux Pumps and Multilocus Sequence Typing in Clinical Isolates of Stenotrophomonas maltophilia  

PubMed Central

Background Stenotrophomonas maltophilia has emerged as an important opportunistic pathogen, which causes infections that are often difficult to manage because of the inherent resistance of the pathogen to a variety of antimicrobial agents. In this study, we analyzed the expressions of smeABC and smeDEF and their correlation with antimicrobial susceptibility. We also evaluated the genetic relatedness and epidemiological links among 33 isolates of S. maltophilia. Methods In total, 33 S. maltophilia strains were isolated from patients in a tertiary hospital in Daejeon. Minimum inhibitory concentrations (MICs) of 11 antimicrobial agents were determined by using agar dilution method and E-test (BioMérieux, France). Real-time PCR analysis was performed to evaluate the expression of the Sme efflux systems in the S. maltophilia isolates. Additionally, an epidemiological investigation was performed using multilocus sequence typing (MLST) assays. Results The findings of susceptibility testing showed that the majority of the S. maltophilia isolates were resistant to ?-lactams and aminoglycosides. Twenty-one clinical isolates overexpressed smeABC and showed high resistance to ciprofloxacin. Moreover, a high degree of genetic diversity was observed among the S. maltophilia isolates; 3 sequence types (STs) and 23 allelic profiles were observed. Conclusions The smeABC efflux pump was associated with multidrug resistance in clinical isolates of S. maltophilia. In particular, smeABC efflux pumps appear to perform an important role in ciprofloxacin resistance of S. maltophilia. The MLST scheme for S. maltophilia represents a discriminatory typing method with stable markers and is appropriate for studying population structures.

Cho, Hye Hyun; Sung, Ji Youn; Kwon, Kye Chul

2012-01-01

39

Dipeptidyl Aminopeptidase IV from Stenotrophomonas maltophilia Exhibits Activity against a Substrate Containing a 4Hydroxyproline Residue  

Microsoft Academic Search

The crystal structure of dipeptidyl aminopeptidase IV from Stenotrophomonas maltophilia was deter- mined at 2.8-Ĺ resolution by the multiple isomorphous replacement method, using platinum and sel- enomethionine derivatives. The crystals belong to space group P43212, with unit cell parameters a b 105.9 Ĺ and c 161.9 Ĺ. Dipeptidyl aminopeptidase IV is a homodimer, and the subunit structure is composed of

Yoshitaka Nakajima; Kiyoshi Ito; Tsubasa Toshima; Takashi Egawa; Heng Zheng; Hiroshi Oyama; Yu-Fan Wu; Eiji Takahashi; Kiyoshi Kyono; Tadashi Yoshimoto

2008-01-01

40

Characterization of Maltocin P28, a Novel Phage Tail-Like Bacteriocin from Stenotrophomonas maltophilia  

PubMed Central

Stenotrophomonas maltophilia is an important global opportunistic pathogen for which limited therapeutics are available because of the emergence of multidrug-resistant strains. A novel bacteriocin, maltocin P28, which is produced by S. maltophilia strain P28, may be the first identified phage tail-like bacteriocin from S. maltophilia. Maltocin P28 resembles a contractile but nonflexible phage tail structure based on electron microscopy, and it is sensitive to trypsin, proteinase K, and heat. SDS-PAGE analysis of maltocin P28 revealed two major protein bands of approximately 43 and 20 kDa. The N-terminal amino acid residues of these two major subunits were sequenced, and the maltocin P28 gene cluster was located on the S. maltophilia P28 chromosome. Our sequence analysis results indicate that this maltocin gene cluster consists of 23 open reading frames (ORFs), and that its gene organization is similar to that of the P2 phage genome and R2 pyocin gene cluster. ORF17 and ORF18 encode the two major structural proteins, which correspond to gpFI (tail sheath) and gpFII (tail tube) of P2 phage, respectively. We found that maltocin P28 had bactericidal activity against 38 of 81 tested S. maltophilia strains. Therefore, maltocin P28 is a promising therapeutic substitute for antibiotics for S. maltophilia infections.

Liu, Jian; Chen, Peng; Zheng, Congyi

2013-01-01

41

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

PubMed Central

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

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

1996-01-01

42

Stenotrophomonas maltophilia infection in hematopoietic SCT recipients: high mortality due to pulmonary hemorrhage.  

PubMed

To clarify the clinical features and outcome of Stenotrophomonas maltophilia infection among hematopoietic SCT (HCT) recipients, we retrospectively reviewed the records of 1085 consecutive HCT recipients and identified 42 episodes in 31 HCT recipients with S. maltophilia infection. We compared these recipients with 30 non-HCT patients with S. maltophilia infection. The mortality rate in HCT recipients was significantly higher than that in non-HCT patients (relative risk 5.7, P=0.04), and we identified seven patients with pulmonary hemorrhage due to S. maltophilia, exclusively in the HCT cohort. Six of these latter seven patients died within 1 day from the onset of hemorrhage and the isolate was identified after death in most cases; one patient, who received empiric therapy for S. maltophilia and granulocyte transfusion, survived for more than 2 weeks. The patients with pulmonary hemorrhage had a more severe and longer duration of neutropenia, persistent fever despite of the use of broad-spectrum antibiotics, complication by pneumonia and higher C-reactive protein levels than those without pulmonary hemorrhage. In conclusion, S. maltophilia was associated with fulminant and fatal pulmonary hemorrhage in HCT recipients. Empiric therapy with antibiotics before the onset of pulmonary hemorrhage may be effective in HCT recipients who carry the conditions identified. PMID:22635245

Tada, K; Kurosawa, S; Hiramoto, N; Okinaka, K; Ueno, N; Asakura, Y; Kim, S-W; Yamashita, T; Mori, S-I; Heike, Y; Maeshima, A M; Tanosaki, R; Tobinai, K; Fukuda, T

2013-01-01

43

Stenotrophomonas maltophilia strains from cystic fibrosis patients: genomic variability and molecular characterization of some virulence determinants.  

PubMed

The genetic relatedness of 52 Stenotrophomonas maltophilia strains, collected from various environmental and clinical sources, including cystic fibrosis (CF) patients, as well as the presence and the expression of some virulence-associated genes were studied. Pulsed-field gel electrophoresis (PFGE) analysis identified 47 profiles and three clusters of isolates with an identical PFGE pattern considered to be indistinguishable strains. Restriction fragment length polymorphism of the gyrB gene grouped the 52 strains into nine different profiles. Most CF clinical isolates (29 out of 41) showed profile 1, while the analysis of the hypervariable regions of the 16S rRNA gene revealed five distinct allelic variations, with the majority of CF isolates (23 out of 41) belonging to sequence group 1. Furthermore, the strains were characterized for motility and expression of virulence-associated genes, including genes encoding type-1 fimbriae, proteases (StmPr1 and StmPr2) and esterase. All S. maltophilia strains exhibited a very broad range of swimming and twitching motility, while none showed swarming motility. A complete smf-1 gene was PCR-amplified only from clinically derived S. maltophilia strains. Finally, the virulence of representative S. maltophilia strains impaired in the expression of proteases and esterase activities was evaluated by infecting larvae of the wax moth Galleria mellonella. The results obtained strongly indicate that the major extracellular protease StmPr1 may be a relevant virulence factor of S. maltophilia. PMID:20952251

Nicoletti, Mauro; Iacobino, Angelo; Prosseda, Gianni; Fiscarelli, Ersilia; Zarrilli, Raffaele; De Carolis, Elena; Petrucca, Andrea; Nencioni, Lucia; Colonna, Bianca; Casalino, Mariassunta

2011-01-01

44

Monotherapy with Fluoroquinolone or Trimethoprim-Sulfamethoxazole for Treatment of Stenotrophomonas maltophilia Infections  

PubMed Central

The treatment of choice for Stenotrophomonas maltophilia is trimethoprim-sulfamethoxazole (SXT). Fluoroquinolones (FQs) have in vitro activity against S. maltophilia; however, there is limited published information on their effectiveness. The purpose of this study is to compare the effectiveness of FQs and SXT for the treatment of S. maltophilia. A retrospective review of 98 patients with S. maltophilia infections who received SXT or FQ monotherapy was conducted. Patients ?18 years old with a positive culture for S. maltophilia and clinical signs of infection who received treatment for ?48 h were included. Microbiological cure and clinical response were evaluated at the end of therapy (EOT). In-hospital mortality and isolation of nonsusceptible isolates were also evaluated. Thirty-five patients received SXT, and 63 patients received FQ; 48 patients received levofloxacin, and 15 patients received ciprofloxacin. The most common infection was pulmonary. The overall microbiological cure rate at EOT was 63%. Thirteen of 20 patients (65%) who received SXT and 23 of 37 patients (62%) who received FQ had microbiological cure at EOT (P = 0.832). The overall clinical success rate was 55%, 52% for those who received FQ and 61% for those who received SXT (P = 0.451). In-hospital mortality was 24%, with similar rates in the two groups (25% for FQ versus 22% for SXT; P = 0.546). Development of resistance on repeat culture was 30% for FQ and 20% for SXT (P = 0.426). Fluoroquinolone and SXT monotherapies may be equally effective for the treatment of S. maltophilia infections. Resistance was documented in subsequent isolates of S. maltophilia in both groups.

Dubrovskaya, Yanina; Papadopoulos, John

2014-01-01

45

Minimal Inhibitory Concentration of Ceftazidime and Co-trimoxazole for Stenotrophomonas Maltophilia using E-test  

PubMed Central

Background Stenotrophomonas maltophilia, previously named as Pseudomonas or Xanthomonas maltophilia, is an important nosocomial pathogen Aim The purpose of the present study was to investigate the prevalence of S. maltophilia in Iranian hospitals and its susceptibility to available antimicrobial agents. Setting and design: A cross-sectional study in Imam Khomeini Hospital affiliated to Tehran University of Medical Sciences. Materials and Methods All blood specimens were sent to the laboratory for blood culture and biochemical analysis. One hundred samples were positive for S. maltophilia. We used disk diffusion and E-test in order to determine minimal inhibitory concentration (MIC) of ceftazidime and co-trimoxazole as the first line antibiotics for S. maltophilia. The tests were performed and interpreted according to the guidelines of Clinical Laboratory Standards Institute (CLSI). Statistical analysis: Chi-square test and Kappa measurement of agreement were applied as appropriate. Results S. maltophilia was the most frequent pathogen (895 specimens; 38.9%) isolated from the samples which were mostly from emergency ward (780 specimens; 33.9%). Ceftazidime MIC50 and MIC90 were 2 and 32 ?g/ml, respectively (sensitive ?8 ?g/ml and resistant ?32 ?g/ml according to CLSI guideline). MIC50 and MIC90 for co-trimoxazole were 0.5 and 2 ?g/ml, respectively (sensitive ?2 ?g/ml and resistant ?4 ?g/ml according to CLSI guideline). Conclusion S. maltophilia is the most frequent pathogen in our hospital with a high susceptibility to both ceftazidime and co-trimoxazole.

Jamali, Firoozeh; Boroumand, Mohammad Ali; Yazdani, Farzad; Anvari, Maryam Sotoudeh; Pourgholi, Leila; Mahfouzi, Saeede; Khak, Mohammad

2011-01-01

46

Stenotrophomonas maltophilia pacemaker endocarditis in a patient with d-transposition of the great arteries after atrial switch procedure.  

PubMed

We report a case of pacemaker endocarditis due to Stenotrophomonas maltophilia in a 22-year-old Caucasian man with d-transposition of the great arteries after atrial switch procedure. S.maltophilia isolated from blood cultures was susceptible to trimethoprim-sulfamethoxazole and amikacin, and resistant to ciprofloxacin and all tested ?-lactam antibiotics. The infected pacemaker system was completely removed by thoracotomy. Simultaneously, a new DDD pacemaker and epicardial electrodes were successfully implanted and selective antibiotic therapy consisting of trimethoprim-sulfamethoxazole (480 mg i.v. q 6 h) and amikacin (250 mg i.v. twice daily) was continued. However, the post-operative course was complicated by septic shock and the patient died on 9th day after surgery. Importantly, S.maltophilia isolated from extracted pacemaker leads was multidrug-resistant including to trimethoprim-sulfamethoxazole, ciprofloxacin, all tested aminoglycosides, and ?-lactams, with the exception of ticarcillin-clavulanate. In conclusion, pacemaker endocarditis due to Stenotrophomonas maltophilia is an extremely rare but serious complication of permanent pacing therapy. The susceptibility of S.maltophilia isolates to antimicrobial agents can change during the course of infection. Despite the inherent resistance of S.maltophilia to most ?-lactam antibiotics, multidrug-resistant strains may be susceptible in vitro to ticarcillin-clavulanate. Further studies are needed to determine the optimal management of patients with pacemaker endocarditis caused by Stenotrophomonas maltophilia. PMID:19171390

Rostoff, Pawel; Paradowski, Andrzej; Gackowski, Andrzej; Konduracka, Ewa; El Massri, Nader; Gajos, Grzegorz; Pfitzner, Roman; Drwila, Rafal; Sadowski, Jerzy; Piwowarska, Wieslawa

2010-12-01

47

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

PubMed Central

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.

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

2012-01-01

48

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

SciTech Connect

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.

Nangia, Yogesh; Wangoo, Nishima; Raman Suri, C. [Institute of Microbial Technology (CSIR), Sector 39-A, Chandigarh 160036 (India); Sharma, Saurabh; Wu, J.-S.; Dravid, Vinayak; Shekhawat, G. S. [Department of Material Science and Engineering and International Institute for Nanotechnology, Northwestern University, Evanston, Illinois 60208 (United States)

2009-06-08

49

Chronic dacryocystitis secondary to Stenotrophomonas maltophilia and Staphylococcus aureus mixed infection.  

PubMed

A 40-year-old woman with a history of recurrent attacks of dacryocystitis for 2?years developed a lacrimal sac abscess. ?-Lactam antibiotics, considered the first-line treatment for dacryocystitis, were ineffective. She underwent dacryocystorhinostomy. Cultures from the lacrimal sac demonstrated the presence of Stenotrophomonas maltophilia and methicillin-sensitive Staphylococcus aureus, both of which are sensitive to trimethoprim-sulfamethoxazole. This rare and antibiotic-resistant bacterial species should be considered in atypical cases of dacryocystitis, and appropriate antibiotics should be started immediately. PMID:24951597

Taskiran Comez, Arzu; Koklu, Asiye; Akcali, Alper

2014-01-01

50

Induction of aromatic ring: cleavage dioxygenases in Stenotrophomonas maltophilia strain KB2 in cometabolic systems  

Microsoft Academic Search

Stenotrophomonas maltophilia KB2 is known to produce different enzymes of dioxygenase family. The aim of our studies was to determine activity of these\\u000a enzymes after induction by benzoic acids in cometabolic systems with nitrophenols. We have shown that under cometabolic conditions\\u000a KB2 strain degraded 0.25–0.4 mM of nitrophenols after 14 days of incubation. Simultaneously degradation of 3 mM of growth\\u000a substrate during 1–3 days

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

2011-01-01

51

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

PubMed

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

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

2009-11-01

52

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

PubMed Central

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.

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

2011-01-01

53

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

PubMed

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

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

2014-05-01

54

Antimicrobial Susceptibility of Stenotrophomonas maltophilia Isolates from Korea, and the Activity of Antimicrobial Combinations against the Isolates  

PubMed Central

The aim of this study was to determine antimicrobial susceptibility of recent clinical Stenotrophomonas maltophilia isolates from Korea, and to compare the activity levels of several combinations of antimicrobials. A total of 206 non-duplicate clinical isolates of S. maltophilia was collected in 2010 from 11 university hospitals. Antimicrobial susceptibility testing was performed using the Clinical Laboratory Standards Institute agar dilution method. In vitro activity of antimicrobial combinations was tested using the checkerboard method. The susceptibility rates to trimethoprim-sulfamethoxazole and minocycline were 96% and 99%, respectively. The susceptibility rate to levofloxacin was 64%. All of four antimicrobial combinations showed synergy against many S. maltophilia isolates. A combination of trimethoprim-sulfamethoxazole plus ticarcillin-clavulanate was most synergistic among the combinations. None of the combinations showed antagonistic activity. Therefore, some of the combinations may be more useful than individual drugs in the treatment of S. maltophilia infection. Further clinical studies are warranted to validate our in vitro test results.

Chung, Hae-Sun; Kim, Young Ree; Shin, Kyeong Seob; Whang, Dong Hee; Ahn, Jee Young; Park, Yeon-Joon; Uh, Young; Chang, Chulhun L.; Shin, Jong Hee; Lee, Hye Soo; Lee, Kyungwon; Chong, Yunsop

2013-01-01

55

[Monosaccharide composition of exopolymer complex in Thiobacillus thioparus and Stenotrophomonas maltophilia].  

PubMed

The bacteria of Thiobacillus thioparus and Stenotrophomonas maltophilia are capable to form a thick biofilm complicated as to its structure on the surface of low-carbon steel. This biofilm formation on any surface occurs under the adhesion of the cells of the plankton growth model with the help of synthesis of muciferous exopolymers with adhesive properties. Hence the monosaccharide composition of the exopolymer complex in the form of polyol acetates was studied by chromate-mass-spectrum method. A significant difference in the composition of exopolymer monosaccharides with the presence of steel model in the medium and without it was established; a change in the monosaccharide composition of mono- and binary culture in the conditions of plankton and biofilm growth was also observed. PMID:18357787

Borets'ka, M O; Ostapchuk, A M; Kozlova, I P

2007-01-01

56

A new Stenotrophomonas maltophilia strain producing laccase. Use in decolorization of synthetics dyes.  

PubMed

Laccase activity was detected in a soil bacterium Stenotrophomonas maltophilia AAP56 identified by biochemical and molecular methods. It was produced in cells at the stationary growth phase in Luria Bertani (LB) medium added by 0.4 mM copper sulfate. The addition of CuSO(4) in culture medium improved production of laccase activity. However, one laccase enzyme was detected by native polyacrylamide gel electrophoresis. The enzyme showed syringaldazine (K (m) = 53 microM), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (K (m) = 700 microM), and pyrocatechol (K (m) = 25 microM) oxidase activity and was activated by addition of 0.1% (v/v) Triton-X-100 in the reaction mixture. Moreover, the laccase activity was increased 2.6-fold by the addition of 10 mM copper sulfate; the enzyme was totally inhibited by ethylenediaminetetraacetic acid (5 mM), suggesting that this laccase is a metal-dependant one. Decolorization activity of some synthetic dyes (methylene blue, methyl green, toluidine blue, Congo red, methyl orange, and pink) and the industrial effluent (SITEX Black) was achieved by the bacteria S. maltophilia AAP56 in the LB growth medium under shaking conditions. PMID:18931956

Galai, Said; Limam, Ferid; Marzouki, M Nejib

2009-08-01

57

Catalase and superoxide dismutase activities in a Stenotrophomonas maltophilia WZ2 resistant to herbicide pollution.  

PubMed

Quinclorac bensulfuron-methyl is a mixed herbicide widely used on paddy rice field to effectively control barnyard grass and most broad-leaved grasses and sedges. We analyzed superoxide dismutase (SOD) and catalase activities in the quinclorac-highly degrading strain Stenotrophomonas maltophilia WZ2 and Gram-negative standard strain Escherichia coli K12 in an attempt to understand antioxidant enzymes in bacteria are produced in response to quinclorac or bensulfuron-methyl, which increases the virulence of the bacteria. MnSOD and two additional catalase isozymes were induced by quinclorac or bensulfuron-methyl in S. maltophilia WZ2, but not in E. coli K12. Quinclorac turned out to be a more sensitive inducer of SOD, whereas bensulfuron-methyl is a more sensitive one of catalase. A mixture of both has effects similar to quinclorac. Results indicate that catalase has a much weakly role in the defense against quinclorac or bensulfuron-methyl induced oxidative stress, whereas SOD could be critical. PMID:18304632

Lü, Zhenmei; Sang, Liya; Li, Zimu; Min, Hang

2009-01-01

58

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

PubMed

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

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

2014-01-01

59

Effects of Green Tea Compound Epigallocatechin-3-Gallate against Stenotrophomonas maltophilia Infection and Biofilm  

PubMed Central

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

Vidigal, Pedrina G.; Musken, Mathias; Becker, Katrin A.; Haussler, Susanne; Wingender, Jost; Steinmann, Eike; Kehrmann, Jan; Gulbins, Erich; Buer, Jan; Rath, Peter Michael; Steinmann, Jorg

2014-01-01

60

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

PubMed Central

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

Valdezate, Sylvia; Vindel, Ana; Martin-Davila, Pilar; Del Saz, Begona Sanchez; Baquero, Fernando; Canton, Rafael

2004-01-01

61

High genetic diversity among Stenotrophomonas maltophilia strains despite their originating at a single hospital.  

PubMed

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

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

2004-02-01

62

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

PubMed Central

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.

Urszula, Guzik; Izabela, Gren; Danuta, Wojcieszynska; Sylwia, Labuzek

2009-01-01

63

Aflatoxin B1 Degradation by Stenotrophomonas Maltophilia and Other Microbes Selected Using Coumarin Medium#  

PubMed Central

Aflatoxin B1 (AFB1) 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 AFB1 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 AFB1 by 82.5% after incubation in the liquid medium at 37 °C for 72 h. The culture supernatant of isolate 35-3 was able to degrade AFB1 effectively, whereas the viable cells and cell extracts were far less effective. Factors influencing AFB1 degradation by the culture supernatant were investigated. Activity was reduced to 60.8% and 63.5% at 20 °C and 30 °C, respectively, from 78.7% at 37 °C. The highest degradation rate was 84.8% at pH 8 and the lowest was only 14.3% at pH 4.0. Ions Mg2+ and Cu2+ were activators for AFB1 degradation, however ion Zn2+ 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 AFB1 by S. maltophilia 35-3 was enzymatic and could have a great potential in industrial applications.

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

2008-01-01

64

NagZ-Dependent and NagZ-Independent Mechanisms for ?-Lactamase Expression in Stenotrophomonas maltophilia  

PubMed Central

?-N-Acetylglucosaminidase (NagZ), encoded by the nagZ gene, is a critical enzyme for basal-level ampC derepression (ampC expression in the absence of ?-lactam challenge) in ampD and dacB mutants of Pseudomonas aeruginosa. Three mutants with a phenotype of basal-level L1 and L2 ?-lactamase derepression in Stenotrophomonas maltophilia have been reported, including KJ?DI (ampDI mutant), KJ?mrcA (mrcA mutant), and KJ?DI?mrcA (ampDI and mrcA double mutant). In this study, nagZ of S. maltophilia was characterized, and its roles in basal-level ?-lactamase derepression, induced ?-lactamase activities, and ?-lactam resistance of KJ?DI, KJ?mrcA, and KJ?DI?mrcA were evaluated. Expression of the nagZ gene was constitutive and not regulated by AmpR, AmpDI, AmpN, AmpG, PBP1a, and NagZ. Introduction of ?nagZ into KJ?DI nearly abolished basal-level derepressed ?-lactamase activity; conversely, introduction of ?nagZ into KJ?mrcA did not affect it. At least two activator ligands (ALs) are thus considered responsible for ?-lactamase expression in the S. maltophilia system, specifically, the NagZ-dependent (AL1) and NagZ-independent (AL2) ligands responsible for the basal-level derepressed ?-lactamase activities of KJ?DI and KJ?mrcA, respectively. The contributions of AL1 and AL2 to the induced ?-lactamase activities may vary with the types of ?-lactams. nagZ inactivation did not affect aztreonam-, cefoxitin-, and carbenicillin-induced ?-lactamase activities, but it attenuated cefuroxime- and piperacillin-induced ?-lactamase activities. Introduction of ?nagZ into KJ, KJ?DI, KJ?mrcA, and KJ?DI?mrcA did not significantly change the MICs of the ?-lactams tested except that the MICs of cefuroxime and piperacillin moderately decreased in strains KJ?Z and KJ?DI?Z (nagZ mutants).

Huang, Yi-Wei; Hu, Rouh-Mei; Lin, Cheng-Wen; Chung, Tung-Ching

2012-01-01

65

Biosorption and biodegradation of triphenyltin by Stenotrophomonas maltophilia and their influence on cellular metabolism.  

PubMed

Triphenyltin (TPT), an endocrine disruptor, is polluting the global environment through its worldwide use. However, information concerning the mechanisms of TPT biodegradation and cellular metabolism is severely limited. Therefore, these processes were elucidated through experiments involving TPT biosorption and degradation, intracellular metabolite analysis, nutrient use, ion and monosaccharide release, cellular membrane permeability and protein concentration quantification. The results verified that TPT was initially adsorbed by the cell surface of Stenotrophomonas maltophilia and was subsequently transported and degraded intracellularly with diphenyltin and monophenyltin production. Cl(-), Na(+), arabinose and glucose release, membrane permeability and the extracellular protein concentration increased during TPT treatment, whereas K(+) and PO4(3-) utilization and intracellular protein concentration declined. The biosorption, degradation and removal efficiencies of TPT at 0.5mgL(-1) by 0.3gL(-1) viable cells at 10 d were 3.8, 77.8 and 86.2%, respectively, and the adsorption efficiency by inactivated cells was 72.6%. PMID:24866561

Gao, Jiong; Ye, Jinshao; Ma, Jiawen; Tang, Litao; Huang, Jie

2014-07-15

66

Clinical Factors Associated with Acquisition of Resistance to Levofloxacin in Stenotrophomonas maltophilia  

PubMed Central

Purpose Fluoroquinolones, rapidly gaining prominence in treatment of Stenotrophomonas maltophilia (SMP), are noted for their potency and tolerability. However, SMP may rapidly acquire resistance to fluoroquinolones. We evaluated associations of clinical factors with acquisition of levofloxacin resistance (LFr) in SMP. Materials and Methods Our retrospective cohort study was based on patient data collected between January 2008 and June 2010. Through screening of 1275 patients, we identified 122 patients with data for SMP antibiotic susceptibility testing in ?3 serial SMP isolates. Results We assigned the 122 patients to either the SS group (n=54) in which levofloxacin susceptibility was maintained or the SR group (n=31) in which susceptible SMP acquired resistance. In multivariate regression analysis, exposure to levofloxacin for more than 3 weeks [odds ratio (OR) 15.39, 95% confidential interval (CI) 3.08-76.93, p=0.001] and co-infection or co-colonization with Klebsiella pneumoniae resistant to levofloxacin (OR 4.85, 95% CI 1.16-20.24, p=0.030) were independently associated with LFr acquisition in SMP. Conclusion Acquisition of LFr during serial sampling of SMP was related to the levofloxacin exposure.

Baek, Ji Hyeon; Kim, Chang Oh; Jeong, Su Jin; Ku, Nam Soo; Choi, Jun Yong; Yong, Dongeun; Song, Young Goo; Lee, Kyungwon; Kim, June Myung

2014-01-01

67

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

PubMed Central

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.

Karaba, Sara M.; White, Richard C.

2013-01-01

68

Stenotrophomonas (Xanthomonas) maltophilia as an Emerging Opportunistic Pathogen in Association with HIV Infection: A 10Year Surveillance Study  

Microsoft Academic Search

.  \\u000a \\u000a Background: Stenotrophomonas (Xanthomonas) maltophilia has been increasingly reported as a nosocomial opportunistic pathogen, responsible for serious infectious complications\\u000a in immunocompromised patients. At present very limited information is available concerning its clinical significance in the\\u000a setting of HIV infection.\\u000a \\u000a \\u000a \\u000a \\u000a Patients and Methods: A retrospective survey of clinical and microbiological records of 1,374 HIV-infected patients referring to our tertiary care\\u000a center

L. Calza; R. Manfredi; F. Chiodo

2003-01-01

69

Cloning and characterization of SmeT, a repressor of the Stenotrophomonas maltophilia multidrug efflux pump SmeDEF.  

PubMed

We report on the cloning of the gene smeT, which encodes the transcriptional regulator of the Stenotrophomonas maltophilia efflux pump SmeDEF. SmeT belongs to the TetR and AcrR family of transcriptional regulators. The smeT gene is located upstream from the structural operon of the pump genes smeDEF and is divergently transcribed from those genes. Experiments with S. maltophilia and the heterologous host Escherichia coli have demonstrated that SmeT is a transcriptional repressor. S1 nuclease mapping has demonstrated that expression of smeT is driven by a single promoter lying close to the 5' end of the gene and that expression of smeDEF is driven by an unique promoter that overlaps with promoter PSMET: The level of expression of smeT is higher in smeDEF-overproducing S. maltophilia strain D457R, which suggests that SmeT represses its own expression. Band-shifting assays have shown that wild-type strain S. maltophilia D457 contains a cellular factor(s) capable of binding to the intergenic smeT-smeD region. That cellular factor(s) was absent from smeDEF-overproducing S. maltophilia strain D457R. The sequence of smeT from D457R showed a point mutation that led to a Leu166Gln change within the SmeT protein. This change allowed overexpression of both smeDEF and smeT in D457R. It was noteworthy that expression of wild-type SmeT did not fully complement the smeT mutation in D457R. This suggests that the wild-type protein is not dominant over the mutant SmeT. PMID:12384340

Sánchez, Patricia; Alonso, Ana; Martinez, Jose L

2002-11-01

70

Clinical characteristics and outcomes of patients with pleural infections due to Stenotrophomonas maltophilia at a medical center in Taiwan, 2004-2012.  

PubMed

Stenotrophomonas maltophilia can cause various clinical diseases; however, pleural infections due to S. maltophilia are rare. We evaluated the clinical characteristics and outcomes of patients with pleural infections (complicated parapneumonic effusion or empyema) due to S. maltophilia who were treated at a medical center in Taiwan from 2004 to 2012. During the study period, 40 patients were treated for pleural infections due to S. maltophilia. The incidence of S. maltophilia pleural infections ranged from 2.66 per 1,000,000 patient-days in 2009 to 12.44 per 1,000,000 patient-days in 2011. Most of the patients with S. maltophilia pleural infections were immunocompromised male adults and all of the infections were acquired in healthcare settings. The majority of patients had polymicrobial pleural infections (n?=?31, 77.5 %) and the most common pathogen was Pseudomonas aeruginosa (n?=?12). The causes of pleural infections due to S. maltophilia were pneumonia due to S. maltophilia in two patients (5 %), post-surgical/tube thoracostomy in 26 (65 %) patients, and fistula (bronchopleural, esophagopleural and biliopleural) in 12 (30 %) patients. The 14-day and 30-day mortality rates were 32.5 % and 42.5 %, respectively. Pleural infections due to S. maltophilia are most commonly the result of surgical procedures, thoracostomy, and underlying fistulas. These infections are associated with a high mortality rate, especially among immunocompromised patients. PMID:24458500

Lee, M-R; Wang, H-C; Yang, C-Y; Lin, C-K; Kuo, H-Y; Ko, J-C; Sheng, W-H; Lee, L-N; Yu, C-J; Hsueh, P-R

2014-07-01

71

Antimicrobial susceptibility profile of molecular typed cystic fibrosis Stenotrophomonas maltophilia isolates and differences with noncystic fibrosis isolates.  

PubMed

Multiresistance in Stenotrophomonas maltophilia limits the effectiveness of antimicrobial therapy for infections due to this organism. It can be of special concern in cystic fibrosis (CF) patients due to frequent antimicrobial administration. The in vitro activity of 41 antimicrobial agents against 76 epidemiologically defined CF S. maltophilia isolates by pulsed-field-gel electrophoresis (PFGE) technique under XbaI and SpeI restriction was compared with that obtained with 51 non-CF strains recovered from respiratory sources. Minimal inhibitory concentrations (MICs) were determined with the standard National Committee for Clinical Laboratory Standards agar dilution technique, but with 24-hr incubation. Forty-seven different PFGE profiles were observed within 76 S. maltophilia CF isolates. Minocycline (resistance rate, 0%; MIC(90), 1 microg/ml), doxycycline (6.4%; 8 microg/ml), trovafloxacin (4.2%; 2 microg/ml), moxifloxacin (6.3%; 2 microg/ml), clinafloxacin (6.3%; 2 g/ml), and moxalactam (17.0%; 64 g/ml) displayed low resistance rates. On the contrary, resistance rates were higher with ceftazidime (70.0%; 256 microg/ml), cefepime (83.0%; 128 microg/ml), piperacillin (87.2%; >1,024 microg/ml), ticarcillin (87.2%; >512 microg/ml), and aztreonam (95.7%; >1,024 microg/ml). Clavulanate reverted resistance to ticarcillin and aztreonam in 40.4% and 31.7% of strains, respectively. Aminoglycosides displayed reduced activities with susceptibility rates lower than 20% and MIC(90) higher than 128 microg/ml. With the exception of trimethoprim-sulfamethoxazole (25.4 vs. 31.3%), CF isolates were more resistant than non-CF isolates. Remarkably, resistance was enhanced in S. maltophilia isolates persistently recovered in chronically colonized patients. Susceptibility analysis demonstrated higher resistance rates among CF S. maltophilia isolates when compared with respiratory isolates from non-CF patients. Moreover, persistently recovered CF S. maltophilia isolates were more resistant than sporadic non-CF isolates. PMID:12526070

Cantón, Rafael; Valdezate, Sylvia; Vindel, Ana; Sánchez Del Saz, Begońa; Maíz, Luis; Baquero, Fernando

2003-02-01

72

Involvement of Mutation in ampD I, mrcA, and at Least One Additional Gene in ?-Lactamase Hyperproduction in Stenotrophomonas maltophilia  

PubMed Central

It has been reported that targeted disruption of ampD I or mrcA causes ?-lactamase hyperproduction in Stenotrophomonas maltophilia. We show here that ?-lactamase-hyperproducing laboratory selected mutants and clinical isolates can have wild-type ampD I and mrcA genes, implicating mutation of at least one additional gene in this phenotype. The involvement of mutations at multiple loci in the activation of ?-lactamase production in S. maltophilia reveals that there are significant deviations from the enterobacterial paradigm of AmpR-mediated control of ?-lactamase induction. We do show, however, that S. maltophilia ampD I can complement a mutation in Escherichia coli ampD. This suggests that an anhydromuropeptide degradation product of peptidoglycan is used to activate AmpR in S. maltophilia, as is also the case in enteric bacteria.

Talfan, Asmaa; Mounsey, Oliver; Charman, Matthew; Townsend, Eleanor

2013-01-01

73

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

PubMed Central

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.

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

1995-01-01

74

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

PubMed Central

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.

Sanchez, Maria B; Hernandez, Alvaro; Rodriguez-Martinez, Jose M; Martinez-Martinez, Luis; Martinez, Jose L

2008-01-01

75

Influence of metal ions on bioremediation activity of protocatechuate 3,4-dioxygenase from Stenotrophomonas maltophilia KB2.  

PubMed

The aim of this paper was to describe the effect of various metal ions on the activity of protocatechuate 3,4-dioxygenase from Stenotrophomonas maltophilia KB2. We also compared activity of different dioxygenases isolated from this strain, in the presence of metal ions, after induction by various aromatic compounds. S. maltophilia KB2 degraded 13 mM 3,4-dihydroxybenzoate, 10 mM benzoic acid and 12 mM phenol within 24 h of incubation. In the presence of dihydroxybenzoate and benzoate, the activity of protocatechuate 3,4-dioxygenase and catechol 1,2-dioxygenase was observed. Although Fe(3+), Cu(2+), Zn(2+), Co(2+), Al(3+), Cd(2+), Ni(2+) and Mn(2+) ions caused 20-80 % inhibition of protocatechuate 3,4-dioxygenase activity, the above-mentioned metal ions (with the exception of Ni(2+)) inhibited catechol 1,2-dioxygenase to a lesser extent or even activate the enzyme. Retaining activity of at least one of three dioxygenases from strain KB2 in the presence of metal ions makes it an ideal bacterium for bioremediation of contaminated areas. PMID:23014843

Guzik, Urszula; Hupert-Kocurek, Katarzyna; Sa?ek, Karina; Wojcieszy?ska, Danuta

2013-02-01

76

Activities of Ciprofloxacin and Moxifloxacin against Stenotrophomonas maltophilia and Emergence of Resistant Mutants in an In Vitro Pharmacokinetic-Pharmacodynamic Model  

Microsoft Academic Search

A two-compartment in vitro pharmacokinetic-pharmacodynamic model, with full computer-controlled de- vices, was used to accurately simulate human plasma pharmacokinetic profiles after multidose oral regimens of ciprofloxacin (750 mg every 12 h) and moxifloxacin (400 mg every 24 h) during 48 h. Pharmacodynamics of these drugs was investigated against three quinolone-susceptible strains of Stenotrophomonas maltophilia (MICs of ciprofloxacin and moxifloxacin of

Boubakar B. Ba; Hala Feghali; Corinne Arpin; Marie-Claude Saux; Claudine Quentin

2004-01-01

77

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

PubMed

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

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

2002-03-01

78

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

PubMed Central

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

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

2002-01-01

79

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

PubMed Central

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.

Perez, Pablo N.; Ramirez, Maria A.; Fernandez, Jose A.; de Guevara, Laura Ladron

2014-01-01

80

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

PubMed Central

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

Mukherjee, Piyali; Roy, Pranab

2013-01-01

81

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

PubMed

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

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

2014-06-01

82

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

PubMed Central

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.

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

2013-01-01

83

Antibacterial and cytotoxic efficacy of extracellular silver nanoparticles biofabricated from chromium reducing novel OS4 strain of Stenotrophomonas maltophilia.  

PubMed

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

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

2013-01-01

84

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

PubMed Central

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

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

2002-01-01

85

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

PubMed Central

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

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

2013-01-01

86

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

PubMed

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

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

2014-04-01

87

In vitro antibacterial and antibiofilm activities of chlorogenic acid against clinical isolates of Stenotrophomonas maltophilia including the trimethoprim/sulfamethoxazole resistant strain.  

PubMed

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

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

2013-01-01

88

Proteomic analysis of clinical isolate of Stenotrophomonas maltophilia with blaNDM-1, blaL1 and blaL2 ?-lactamase genes under imipenem treatment.  

PubMed

The co-occurrence of L1 and AmpR-L2 with bla(NDM-1) gene with an upstream 250-bp promoter was detected in a clinical isolate of Stenotrophomonas maltophilia DCPS-01, which was resistant to all ?-lactams and sensitive only to colistin and fluoroquinolones. To investigate expression of resistance genes and the molecular mechanisms of bacteria resistance to carbapenems, proteomic profiles of the isolate was passaged with and without the drug by using 2D-PAGE. The results showed that 33 genes exhibiting a ?3-fold change were identified as candidates that may help S. maltophilia survive drug selection. Strikingly, L1 was expressed more highly in cells grown with imipenem, and the abundant NDM-1 further increased, while very little L2 was detected even following induction. Specific activities for ?-lactamase revealed that L2 remained at constitutive low levels (10.6 U/mg), while L1 and NDM-1 showed clear activity (69.8 U/mg). Our data support that imipenem could specifically and reversibly induce L1 and NDM-1, which together played key roles in drug resistance in DCPS-01. Although NDM-1 mediated resistance to carbapenems has been found in very few cases, to our knowledge, this is the first proteomics research of S. maltophilia with NDM-1, giving very broad-spectrum antibiotic resistance profiles. PMID:22702735

Liu, Wei; Zou, Dayang; Wang, Xuesong; Li, XueLian; Zhu, Li; Yin, Zhitao; Yang, Zhan; Wei, Xiao; Han, Li; Wang, Yufei; Shao, Changlin; Wang, Simiao; He, Xiang; Liu, Dawei; Liu, Feng; Wang, Jie; Huang, Liuyu; Yuan, Jing

2012-08-01

89

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

PubMed

Stenotrophomonas maltophilia, which is a non-fermentative gram-negative bacillus, has an increasing importance in nosocomial and opportunistic infections. Since it exhibits resistance to numerous broad-spectrum antibiotics such as aminoglycosides, beta-lactams and tetracyclines, it may considerably limit empirical treatment options. Trimethoprim-sulfamethoxazole (SXT) is recommended as the first-line therapy in the treatment of S.maltophilia infections thanks to its high potency and usefulness in a range of patients. In recent years, however, studies in different geographical regions have started to report resistance to SXT. In this study, we aimed to investigate the genes sul1, sul2, dfrA9, dfrA10, dfrA20 and class I, class II integron gene cassettes which are known to play role in SXT resistance among SXT-resistant S.maltophilia strains. A total of 618 S.maltophilia strains isolated from various clinical samples of 339 patients between January 2006 and October 2011 at the laboratory of Medical Microbiology Department, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey, were included in the study. The isolates were identified by both conventional methods and the Phoenix automated identification system (Becton Dickinson, USA). SXT resistance was determined in the isolates of 32 patients (32/339, 9.4%) by both the automated system and agar dilution method of them 29 (90.6%) were hospital-acquired, and 3 (9.4%) were community-acquired. The genes which are known as SXT resistance determining genes including sul1, sul2, dfr genes, and class I and class II integron gene cassettes were analyzed by using specific primers with polymerase chain reaction in the 32 SXT-resistant isolates. Subsequently, nucleotide sequence analysis of the amplified materials was performed. As a result of this assay, the presence of class I integron gene cassette and sul1 gene were detected in one isolate. Nucleotide sequence analysis of the gene cassette revealed oxacilinase (oxa2) type of beta-lactamase, an aminoglycoside 6'-N-acetyltransferase [aac(6')-IIc], leading to resistance of aminoglycosides, and a quaternary ammonium compounds resistance gene (qacF), respectively. In conclusion, to best of our knowledge the sequences of class I integron gene cassette including oxa2, aac(6')-IIc, qacF genes were identified in S.maltophilia for the first time. It should be kept in mind that the co-presence of a class I integron gene cassette and the sul1 gene in S.maltophilia may lead to the development of multi-drug resistance and may act as a potential source for the dissemination of resistance. PMID:24819258

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

2014-04-01

90

Rapid genotyping of Achromobacter xylosoxidans, Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia isolates using melting curve analysis of RAPD-generated DNA fragments (McRAPD).  

PubMed

Typing of bacteria is important for monitoring newly emerging pathogens and for examining local outbreaks. We evaluated the randomly amplified polymorphic DNA technique in combination with melting curve analysis (McRAPD) of the amplified DNA fragments to genotype isolates from five Gram-negative species, i.e. Achromobacter xylosoxidans, Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia. By determining the melting temperature peaks of the amplified DNA fragments, we were able to distinguish the different genotypes of isolates, as they had been assessed by other genotyping techniques, i.e. agarose gel electrophoresis of RAPD fragments, multilocus sequence typing and/or AFLP™. According to our results, McRAPD may offer the possibility of genotyping a limited number of bacterial isolates, e.g. in case of suspicion of hospital outbreak, via a less costly, more rapid, less laborious and more user-friendly technique than RAPD followed by electrophoresis. PMID:21320595

Deschaght, Pieter; Van Simaey, Leen; Decat, Ellen; Van Mechelen, Els; Brisse, Sylvain; Vaneechoutte, Mario

2011-05-01

91

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

PubMed Central

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 ?-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 ?-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.

2012-01-01

92

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

PubMed Central

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.

Romero, Antonio; Martinez, Jose L.

2011-01-01

93

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

PubMed Central

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.

Mukherjee, Piyali; Roy, Pranab

2013-01-01

94

Strenotrophomonas maltophilia-related chronic dacryocystitis.  

PubMed

Dacryocystitis related to Stenotrophomonas maltophilia is rare. We describe a case of Strenotrophomonas maltophilia-related chronic dacryocystitis with associated coagulase-negative Staphylococcus. Following external dacryocystorhinostomy without intraoperative or postoperative antibiotics, her discharge and lacrimal sac fullness resolved. PMID:22690904

Marx, Douglas P; Chang, Peter T; Winthrop, Kevin L

2012-12-01

95

The immunomodulatory effect of antibiotics on the secretion of tumour necrosis factor alpha by peripheral blood mononuclear cells in response to Stenotrophomonas maltophilia stimulation  

Microsoft Academic Search

Some antibiotics have been shown to modify the host immune response. Infection with Stenotro- phomonas maltophilia, is often difficult to treat due to multiresistance to antibiotics. The authors exam- ined the effect of four commonly used antimicrobial agents (ciprofloxacin, ceftazidime, cotrimoxazole and piperacillin-tazobactam) on tumour necrosis factor alpha (TNF?) production by human peripher- al blood mononuclear cells (PBMC) stimulated with

IE Vickers; MF Smikle

2006-01-01

96

The versatility and adaptation of bacteria from the genus Stenotrophomonas  

SciTech Connect

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.

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

97

PCR-based rapid genotyping of Stenotrophomonas maltophilia isolates  

Microsoft Academic Search

BACKGROUND: All bacterial genomes contain repetitive sequences which are members of specific DNA families. Such repeats may occur as single units, or found clustered in multiple copies in a head-to-tail configuration at specific loci. The number of clustered units per locus is a strain-defining parameter. Assessing the length variability of clusters of repeats is a versatile typing methodology known as

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

2008-01-01

98

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

PubMed Central

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.

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

2014-01-01

99

Characterization of a novel Stenotrophomonas isolate with high keratinase activity and purification of the enzyme  

Microsoft Academic Search

A feather-degrading bacterium was isolated from poultry decomposition feathers in China. The strain, named L1, showed significant\\u000a feather-degrading activity because it grew and reproduced quickly on basal medium containing 10 g\\/L of native feather as the\\u000a source of energy, carbon, and nitrogen. According to the phenotypic characteristics and 16S rRNA profile, the isolate belongs\\u000a to Stenotrophomonas maltophilia. Keratinase activity of the isolate

Zhang-Jun Cao; Qi Zhang; Dong-Kai Wei; Li Chen; Jing Wang; Xing-Qun Zhang; Mei-Hua Zhou

2009-01-01

100

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

PubMed Central

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.

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

1989-01-01

101

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

PubMed Central

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

2014-01-01

102

Transformation and Precipitation of Toxic Metals by Pseudomonas Maltophilia.  

National Technical Information Service (NTIS)

The aims of this research were to study each of the various molecular mechanisms whereby toxic metal cations and oxyanions were chemically transformed by Pseudomonas maltophilia strain OR02. The research effort focused on the microbial-dependent transform...

R. Blake

1992-01-01

103

Tracking of the viability of Stenotrophomonas maltophilia bacteria population in polyvinylalcohol nanofiber webs by positron annihilation lifetime spectroscopy.  

PubMed

Polyvinylalcohol (PVA) fiber web containing embedded bacteria was prepared by electrospinning technique. From the point of the complex functionality of such potential delivery systems, it will be of impact how bacteria can survive in such artificial biotopes. The present study suggests a possible fast method for the tracking of the viability of the embedded bacteria based on the changes of the supramolecular structure of the polymeric delivery system caused by the metabolic product of the bacteria. Positron annihilation lifetime spectroscopy (PALS) was applied to track the free volume changes of the system in the course of storage. The PALS method sensitively detected the free volume changes, thus the viability of the bacteria in the polymeric fiber web. PMID:22449412

Vajdai, Attila; Szabó, Barnabás; Süvegh, Károly; Zelkó, Romána; Ujhelyi, Gabriella

2012-06-15

104

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

Microsoft Academic Search

strongly interferes with selenite removal when the two oxyanions (NO2 and SeO3 2 ) are simultaneously present, suggesting that the two reduction\\/detoxification pathways share a common enzymatic step, probably at the level of cellular transport; (iii) in vitro, selenite reduction does not take place in the membrane or periplasmic fractions but only in the cytoplasm, where maximum activity is exhibited

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

2007-01-01

105

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

PubMed Central

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

Juhnke, M E; des Jardin, E

1989-01-01

106

Molecular insights into substrate specificity of Rhodococcus ruber CGMCC3090 by gene cloning and homology modeling.  

PubMed

The primary aim of this study was to decipher the catalytic functions of the NHase with wide substrate spectra from Rhodococcus ruber CGMCC3090 by computer modeling and substrate docking. 3D structure model of the enzyme was built by computer modeling to obtain the optimal structure. The larger binding site cavity (559 Ĺ(3)) indicated that this NHase may catalyze a large variety of substrates of nitriles. Some key residues such as ?Glu82, ?Gln83, ?Tyr71, ? Tyr72, ? Arg52 and ? Arg55 surrounding the binding site were unique compared with those of 3QXE as a template, indicating that the enzyme may have unusual substrate specificity. The docking and the biotransformation experiments demonstrated that the special docking pose and shorter distance proved to be more effective for the enzyme to improve function. PMID:23273280

Wang, Shiwei; Dai, Yujie; Wang, Jianxin; Shen, Yanbing; Zhai, Ying; Zheng, Heng; Wang, Min

2013-02-01

107

2-Ketogluconic acid production by Klebsiella pneumoniae CGMCC 1.6366.  

PubMed

Klebsiella pneumoniae CGMCC 1.6366 is a bacterium isolated for 1,3-propanediol or 2,3-butanediol production previously. K. pneumoniae ?budA, a 2,3-butanediol synthesis pathway truncated mutant with the gene deletion of budA which encodes alpha-acetolactate decarboxylase, was found to execrate an unknown chemical at a high titer when grown in the broth using glucose as carbon source. Later this chemical was identified to be 2-ketogluconic acid, which was formed through the glucose oxidation pathway in K. pneumoniae. It was found that 2-ketogluconic can also be produced by the wild strain. The fermentation studies showed that the production of this metabolite is strictly pH dependent, when the fermenting broth was maintained at pH 6-7, the main metabolite produced by K. pneumoniae CGMCC 1.6366 was 2,3-butanediol, or some organic acids in the budA mutated strain. However, if the cells were fermented at pH 4.7, 2-ketogluconic acid was formed, and the secretion of all other organic acids or 2,3-butanediol were limited. In the 5L bioreactors, a final level of 38.2 and 30.2 g/L 2-ketogluconic acid were accumulated by the wild type and the budA mutant K. pneumoniae, respectively, in 26 and 56 h; and the conversion ratios of glucose to 2-ketogluconic acid reached 0.86 and 0.91 mol/mol for the wild and the budA mutant, respectively. PMID:23508456

Wei, Dong; Xu, Jiqing; Sun, Junsong; Shi, Jiping; Hao, Jian

2013-06-01

108

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

PubMed

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

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

2013-09-01

109

Co-metabolic transformation of the neonicotinoid insecticide imidacloprid by the new soil isolate Pseudoxanthomonas indica CGMCC 6648.  

PubMed

A new imidacloprid (IMI) degrading bacterium Z-9 (deposited number CGMCC 6648) was isolated and identified as Pseudoxanthomonas indica by 16S rRNA gene analysis. Two metabolites were identified as olefin and 5-hydroxy IMI by liquid chromatography-mass spectrometry and nuclear magnetic resonance analysis. P. indica CGMCC 6648 degraded 70.1% of IMI (1.22 mmol L(-1)) and formed 0.93 mmol L(-1) 5-hydroxy IMI and 0.05 mmol L(-1) olefin IMI in 6 days and in the presence of 100 mmol L(-1) glucose. The half-life of IMI degradation was 3.6 days. P. indica CGMCC 6648 transforms IMI via a co-metabolism mechanism and different carbohydrates have significant effects on 5-hydroxy IMI formation, whereas different organic acids have substantial effects on olefin IMI production. Lactose is the best co-substrate for IMI degradation and 5-hydroxy IMI formation with 0.77 mmol L(-1) degraded and 0.67 mmol L(-1) formed in 48 h, respectively. Pyruvate is the best co-substrate for olefin IMI formation with 0.17 mmol L(-1) produced in 96 h for all carbon sources tested. Pyruvate significantly stimulates the conversion of 5-hydroxy IMI to olefin IMI, whereas glucose slightly inhibits this reaction. P. indica CGMCC 6648 rapidly degrades IMI and forms olefin IMI, which may enhance its potential for biodegradation of IMI and increase its insecticidal activity, which can decrease the IMI dosage required. PMID:25035915

Ma, Yuan; Zhai, Shan; Mao, Shi Yun; Sun, Shi Lei; Wang, Ying; Liu, Zhong Hua; Dai, Yi Jun; Yuan, Sheng

2014-09-01

110

Biodegradation of p -nitrophenol and 4-chlorophenol by Stenotrophomonas sp  

Microsoft Academic Search

A bacterium named LZ-1 capable of utilizing high concentrations of p-nitrophenol (PNP) (up to 500mgL1) as the sole source of carbon, nitrogen and energy was isolated from an activated sludge. Based on the results of phenotypic features and phylogenetic similarity of 16S rRNA gene sequences, strain LZ-1 was identified as a Stenotrophomonas sp. Other p-substituted phenols such as 4-chlorophenol (4-CP)

Zheng Liu; Chao Yang; Chuanling Qiao

111

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

PubMed

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

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

2012-06-01

112

Prevalence of serotypes of Xanthomonas maltophilia from world-wide sources.  

PubMed Central

Since its development in 1988, a serologic typing scheme for Xanthomonas maltophilia, based on 31 O antigens, has been successfully used to serotype isolates involved in nosocomial outbreaks in the United States. To determine if this serotyping scheme would be useful in typing X. maltophilia isolates from world-wide sources, we obtained additional isolates from 10 countries; of 900 isolates tested, 795 (88.3%) were typable. In order of predominance, the three most common serotypes were 10, 3 and 19. These three serotypes were most frequently associated with respiratory and blood isolates. This serotyping system is useful as an epidemiologic screening method for universal typing of outbreaks of X. maltophilia infections.

Schable, B.; Rhoden, D. L.; Jarvis, W. R.; Miller, J. M.

1992-01-01

113

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

PubMed

The present study investigated the impact of a Lactobacillus rhamnosus CGMCC1.3724 (LPR) supplementation on weight loss and maintenance in obese men and women over 24 weeks. In a double-blind, placebo-controlled, randomised trial, each subject consumed two capsules per d of either a placebo or a LPR formulation (1.6 × 10(8) colony-forming units of LPR/capsule with oligofructose and inulin). Each group was submitted to moderate energy restriction for the first 12 weeks followed by 12 weeks of weight maintenance. Body weight and composition were measured at baseline, at week 12 and at week 24. The intention-to-treat analysis showed that after the first 12 weeks and after 24 weeks, mean weight loss was not significantly different between the LPR and placebo groups when all the subjects were considered. However, a significant treatment × sex interaction was observed. The mean weight loss in women in the LPR group was significantly higher than that in women in the placebo group (P = 0.02) after the first 12 weeks, whereas it was similar in men in the two groups (P= 0.53). Women in the LPR group continued to lose body weight and fat mass during the weight-maintenance period, whereas opposite changes were observed in the placebo group. Changes in body weight and fat mass during the weight-maintenance period were similar in men in both the groups. LPR-induced weight loss in women was associated not only with significant reductions in fat mass and circulating leptin concentrations but also with the relative abundance of bacteria of the Lachnospiraceae family in faeces. The present study shows that the Lactobacillus rhamnosus CGMCC1.3724 formulation helps obese women to achieve sustainable weight loss. PMID:24299712

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

2014-04-28

114

Practical synthesis of optically active alpha,alpha-disubstituted malonamic acids through asymmetric hydrolysis of malonamide derivatives with Rhodococcus sp. CGMCC 0497.  

PubMed

A variety of alpha,alpha-disubstituted malonamides undergo enantioselective hydrolysis with Rhodococcus sp. CGMCC 0497 to give challenging enantiopure alpha,alpha-disubstituted malonamic acids with up to >99% enantiomeric excesses and 98% chemical yields. The enantioselectivity originated from the effects of a highly enantioselective amidase. The products could be converted to valuable (R)- or (S)-alpha,alpha-dialkylated amino acids after routine conversions. PMID:12636421

Wu, Zhong-Liu; Li, Zu-Yi

2003-03-21

115

A novel phytase appA from Citrobacter amalonaticus CGMCC 1696: gene cloning and overexpression in Pichia pastoris.  

PubMed

A novel phytase gene appA, with upstream and downstream sequences from Citrobacter amalonaticus CGMCC 1696, was cloned by degenerate polymerase chain reaction (PCR), and thermal asymmetric interlaced (TAIL) PCR and was overexpressed in Pichia pastoris. Sequence analysis revealed one open reading frame that consisted of 1311 bp encoding a 436-amino-acid protein, which had a deduced molecular mass of 46.3 kDa. The phytase appA belongs to the histidine acid phosphatase family and exhibits the highest identity (70.1%) with C. braakii phytase. The gene was overexpressed in P. pastoris. The secretion yield of recombinant appA protein was accumulated to approximately 4.2 mg.mL(-1), and the enzyme activity level reached 15,000 U x mL(-1), which is higher than any previous reports. r-appA was glycosylated, as shown by Endo H treatment. r-appA was purified and characterized. The specific activity of r-appA for sodium phytate was 3548 U.mg(-1). The optimum pH and temperature for enzyme activity were 4.5 and 55 degrees C, respectively. r-appA was highly resistant to pepsin or trypsin treatment. This enzyme could be an economic and efficient alternative to the phytases currently used in the feed industry. PMID:17657539

Luo, Huiying; Huang, Huoqing; Yang, Peilong; Wang, Yaru; Yuan, Tiezheng; Wu, Ningfeng; Yao, Bin; Fan, Yunliu

2007-09-01

116

A novel beta-propeller phytase from Pedobacter nyackensis MJ11 CGMCC 2503 with potential as an aquatic feed additive.  

PubMed

A phytase with high activity at neutral pH and typical water temperatures ( approximately 25 degrees C) could effectively hydrolyze phytate in aquaculture. In this study, a phytase-producing strain, Pedobacter nyackensis MJ11 CGMCC 2503, was isolated from glacier soil, and the relevant gene, PhyP, was cloned using degenerate PCR and thermal asymmetric interlaced PCR. To our knowledge, this is the first report of detection of phytase activity and cloning of phytase gene from Pedobacter. PhyP belongs to beta-propeller phytase family and shares very low identity ( approximately 28.5%) with Bacillus subtilis phytase. The purified recombinant enzyme (r-PhyP) from Escherichia coli displayed high specific activity for sodium phytate of 24.4 U mg(-1). The optimum pH was 7.0, and the optimum temperature was 45 degrees C. The K (m), V (max), and k (cat) values were 1.28 mM, 71.9 micromol min(-1) mg(-1), and 45.1 s(-1), respectively. Compared with Bacillus phytases, r-PhyP had higher relative activity at 25 degrees C (r-PhyP (>50%), B. subtilis phytase (<8%)) and hydrolyzed phytate from soybean with greater efficacy at neutral pH. These characteristics suggest that r-PhyP might be a good candidate for an aquatic feed additive in the aquaculture industry. PMID:19139877

Huang, Huoqing; Shao, Na; Wang, Yaru; Luo, Huiying; Yang, Peilong; Zhou, Zhigang; Zhan, Zhichun; Yao, Bin

2009-05-01

117

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

PubMed

In order to improve the use of waste beer yeast (WBY) for bacterial cellulose production by Gluconacetobacter hansenii CGMCC 3917, a two-step pre-treatment was designed. First WBY was treated by 4 methods: 0.1M NaOH treatment, high speed homogenizer, ultrasonication and microwave treatment followed by hydrolysis (121°C, 20 min) under mild acid condition (pH 2). The optimal pre-treatment conditions were evaluated by the reducing sugar yield after hydrolysis. 15% WBY treated by ultrasonication for 40 min had the highest reducing sugar yield (29.19%), followed by NaOH treatment (28.98%), high speed homogenizer (13.33%) and microwaves (13.01%). Treated WBY hydrolysates were directly supplied as only nutrient source for BC production. A sugar concentration of 3% WBY hydrolysates treated by ultrasonication gave the highest BC yield (7.02 g/L), almost 6 times as that from untreated WBY (1.21 g/L). Furthermore, the properties of the BC were as good as those obtained from the conventional chemical media. PMID:24212131

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

2014-01-01

118

Sophorolipid production from delignined corncob residue by Wickerhamiella domercqiae var. sophorolipid CGMCC 1576 and Cryptococcus curvatus ATCC 96219.  

PubMed

Delignined corncob residue hydrolysate (DCCRH) and detoxified DCCRH were used for single cell oil (SCO) and single cell protein (SCP) production of Cryptococcus curvatus ATCC 96219 and for sophorolipid (SL) production of Wickerhamiella domercqiae var. sophorolipid CGMCC 1576. Both C. curvatus and W. domercqiae could utilize glucose in DCCRH to grow and accumulate lipids or particle-shaped SLs. DCCRH detoxification by activated carbon adsorption not only improved cell growth and lipid accumulation of C. curvatus but also increased SL production and proportion of lactonic SL in total SL. A total biomass of 17.36 g/l with a lipid content of 44.36 % could be achieved after cultivation of C. curvatus on the detoxified DCCRH. The predominant fatty acids of the produced SCO were oleic, stearic, and palmitic acids (27.2, 20.5, and 15.7 %, respectively). When W. domercqiae cells were cultivated on DCCRH and SCO, total SL production of 39.08 g/l (DCCRH?+?SCO) and 42.06 g/l (detoxified DCCRH?+?SCO) were obtained. Furthermore, when cell lysate of C. curvatus, oleic acid, and DCCRH/detoxified DCCRH was used as nitrogen and carbon sources, total SL production reached 37.19 g/l and 48.97 g/l, respectively. These results demonstrated that renewable DCCRH can be utilized for the production of high-value SCO and SLs. PMID:23532513

Ma, Xiao-jing; Li, Hui; Wang, Dong-xue; Song, Xin

2014-01-01

119

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

PubMed

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

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

2011-10-01

120

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

PubMed

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

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

2014-01-01

121

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

PubMed Central

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.

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

2014-01-01

122

A changing pattern of susceptibility of Xanthomonas maltophilia to antimicrobial agents: implications for therapy.  

PubMed Central

The in vitro susceptibilities of 130 Xanthomonas maltophilia isolates to 12 antibiotics--trimethoprim-sulfamethoxazole, minocycline, ticarcillin-clavulanate, ceftazidime, cefoperazone, cefoperazone-sulbactam, imipenem, ciprofloxacin, and the investigational quinolones PD 117558, PD 117596, PD 127391, and sparfloxacin--were determined by a microtiter broth dilution technique. Other than the investigational quinolones, the most active antibiotics were minocycline, trimethoprim-sulfamethoxazole, and ticarcillin-clavulanate, in order. However, the first two were not bactericidal, while about half of the isolates exhibited intermediate susceptibility to ticarcillin-clavulanate. Patterns of susceptibility to trimethoprim-sulfamethoxazole and ciprofloxacin relative to the years of isolation of these strains reflected the development of resistance to the antibiotic prophylaxis practices in the hospital. We recommend that a combination of antibiotics, such as trimethoprim-sulfamethoxazole, minocycline, and ticarcillin-clavulanate, at or close to the maximum tolerated doses be in the treatment of serious X. maltophilia infections.

Vartivarian, S; Anaissie, E; Bodey, G; Sprigg, H; Rolston, K

1994-01-01

123

Purification and characterization of an alkaline serine endopeptidase from a feather-degrading Xanthomonas maltophilia strain.  

PubMed

A keratinolytic Xanthomonas maltophilia strain (POA-1), cultured on feather meal broth, using keratin as its sole source of carbon and nitrogen, secretes several extracellular peptidases. The major serine peptidase was purified to homogeneity by a five-step procedure. Its purity was evaluated by capillary zone electrophoresis. This enzyme has a molecular mass of 36 kDa, an optimum pH of 9.0, and an optimum temperature of 60 degrees C. The inhibitory profile using protease inhibitors shows that this enzyme is a serine endopeptidase. Besides keratin, the enzyme is active upon the substrates azokeratin, azocasein, and the following fluorogenic peptide substrates: Abz-Leu-Gly-Met-Ile-Ser-Leu-Met-Lys-Arg-Pro-Gln-EDDnp, Abz-Lys-Leu-Cys(SBzl)-Gly-Pro-Lys-Gln-EDDnp, and Abz-Lys-Pro-Cys(SBzl)-Phe-Ser-Lys-Gln-EDDnp. PMID:12030707

De Toni, C H; Richter, M F; Chagas, J R; Henriques, J A P; Termignoni, C

2002-04-01

124

Biochemical properties of inducible beta-lactamases produced from Xanthomonas maltophilia.  

PubMed Central

Four different beta-lactamases have been found in several strains of Xanthomonas maltophilia isolated from blood cultures during 1984 to 1991 at the Edinburgh Royal Infirmary. One was a metallo-beta-lactamase with predominantly penicillinase activity and an isoelectric point of 6.8. Its molecular size as determined by gel filtration was 96 kDa but was only 26 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), suggesting a tetramer of four equal subunits. The enzyme hydrolyzed all classes of beta-lactams except the monobactam aztreonam. This enzyme was not inhibited by potassium clavulanate or BRL 42715 but was inhibited by p-chloromercuribenzoate, mercuric chloride, and EDTA. The beta-lactamase was unstable in 50 mM sodium phosphate buffer (pH 8.0) but stable in 50 mM Tris HCl (pH 8.0). The other beta-lactamases focused as a series of different isoelectric points, ranging from pI 5.2 to 6.6. Together, these enzymes exhibited a broad spectrum of activity, hydrolyzing most classes of beta-lactams but not imipenem or aztreonam. Their molecular size was 48 kDa by Sephadex gel filtration and 24 kDa by SDS-PAGE, indicating that they were enzymes consisting of two equal subunits. They were inhibited by p-chloromercuribenzoate, mercuric chloride, potassium clavulanate, and BRL 42715 but not EDTA. This study demonstrated that X. maltophilia produces more than just the L1 and L2 beta-lactamases. Images

Paton, R; Miles, R S; Amyes, S G

1994-01-01

125

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

PubMed

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

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

2010-10-01

126

Analysis of TNT (2,4,6Trinitrotoluene)Inducible Cellular Responses and Stress Shock Proteome in Stenotrophomonas sp. OK5  

Microsoft Academic Search

In this study, the cellular responses of Stenotrophomonas sp. OK-5 to explosive 2,4,6-trinitrotoluene (TNT) have been extensively analyzed. The stress shock proteins, which might contribute to enhancing cellular resistance to TNT-mediated toxicity, were induced at different concentrations of TNT used as a substrate for cell culture of Stenotrophomonas sp. OK-5 capable of utilizing TNT. Proteomic analysis for 2-DE of soluble

Eun-Mi Ho; Hyo-Won Chang; Seung-Il Kim; Hyung-Yeel Kahng; Kye-Heon Oh

2004-01-01

127

Isolation of New Stenotrophomonas Bacteriophages and Genomic Characterization of Temperate Phage S1?  

PubMed Central

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

Garcia, Pilar; Monjardin, Cristina; Martin, Rebeca; Madera, Carmen; Soberon, Nora; Garcia, Eva; Meana, Alvaro; Suarez, Juan E.

2008-01-01

128

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

PubMed

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

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

2008-12-01

129

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

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

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

2013-09-28

130

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

PubMed Central

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

Felici, A; Amicosante, G

1995-01-01

131

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

SciTech Connect

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.

Su, J.J.

1994-01-01

132

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

PubMed

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

Gunasundari, Dharmaraj; Muthukumar, Karuppan

2013-09-01

133

Arsenic bioremediation potential of a new arsenite-oxidizing bacterium Stenotrophomonas sp. MM-7 isolated from soil.  

PubMed

A new arsenite-oxidizing bacterium was isolated from a low arsenic-containing (8.8 mg kg(-1)) soil. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain was closely related to Stenotrophomonas panacihumi. Batch experiment results showed that the strain completely oxidized 500 ?M of arsenite to arsenate within 12 h of incubation in a minimal salts medium. The optimum initial pH range for arsenite oxidation was 5-7. The strain was found to tolerate as high as 60 mM arsenite in culture media. The arsenite oxidase gene was amplified by PCR with degenerate primers. The deduced amino acid sequence showed the highest identity (69.1 %) with the molybdenum containing large subunit of arsenite oxidase derived from Bosea sp. Furthermore the amino acids involved in binding the substrate arsenite, were conserved with the arsenite oxidases of other arsenite oxidizing bacteria such as Alcaligenes feacalis and Herminnimonas arsenicoxydans. To our knowledge, this study constitutes the first report on arsenite oxidation using Stenotrophomonas sp. and the strain has great potential for application in arsenic remediation of contaminated water. PMID:22760225

Bahar, Md Mezbaul; Megharaj, Mallavarapu; Naidu, Ravi

2012-11-01

134

Emerging Infectious Diseases, Volume 7, No. 1, Jan-Feb 2001. A Peer-Reviewed Journal Tracking and Analyzing Disease Trends.  

National Technical Information Service (NTIS)

Contents: Emerging Chagas Disease: Trophic Network and Cycle of Transmission of Trypanosoma cruzi from Palm Trees in the Amazon; Persistence and Variability of Stenotrophomonas Maltophilia in Cystic Fibrosis Patients, Madrid, 1991-1998; Hospital Control a...

2001-01-01

135

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

PubMed Central

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.

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

1999-01-01

136

?-Dodecelactone Production from Safflower Oil via 10-Hydroxy-12(Z)-octadecenoic Acid Intermediate by Whole Cells of Candida boidinii and Stenotrophomonas nitritireducens.  

PubMed

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

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

2014-07-16

137

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

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

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

2011-04-01

138

Whole-genome sequences of five oyster-associated bacteria show potential for crude oil hydrocarbon degradation.  

PubMed

Draft genome sequences of oyster-associated Pseudomonas stutzeri strain MF28, P. alcaligenes strain OT69, P. aeruginosa strain WC55, Stenotrophomonas maltophilia strain MF89, and Microbacterium maritypicum strain MF109 are reported. Genome-wide surveys of these isolates suggest that the oyster microbiome, which remains largely understudied, has a strong potential to degrade crude oil. PMID:24092793

Chauhan, Ashvini; Green, Stefan; Pathak, Ashish; Thomas, Jesse; Venkatramanan, Raghavee

2013-01-01

139

Resistance in Nonfermenting Gram-Negative Bacteria: Multidrug Resistance to the Maximum  

Microsoft Academic Search

Nonfermenting gram-negative bacteria pose a particular difficulty for the healthcare community because they represent the problem of multidrug resistance to the maximum. Important members of the group in the United States include Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia, and Burkholderia cepacia. These organisms are niche pathogens that primarily cause opportunistic healthcare-associated infections in patients who are critically ill or immunocompromised.

John E. McGowan

2006-01-01

140

Whole-Genome Sequences of Five Oyster-Associated Bacteria Show Potential for Crude Oil Hydrocarbon Degradation  

PubMed Central

Draft genome sequences of oyster-associated Pseudomonas stutzeri strain MF28, P. alcaligenes strain OT69, P. aeruginosa strain WC55, Stenotrophomonas maltophilia strain MF89, and Microbacterium maritypicum strain MF109 are reported. Genome-wide surveys of these isolates suggest that the oyster microbiome, which remains largely understudied, has a strong potential to degrade crude oil.

Green, Stefan; Pathak, Ashish; Thomas, Jesse; Venkatramanan, Raghavee

2013-01-01

141

Infection control and the significance of sputum and other respiratory secretions from adult patients with cystic fibrosis  

Microsoft Academic Search

BACKGROUND: There is limited data available on the environmental and public health impact of the microbiological hazards associated with sputa from patients with cystic fibrosis [CF]. Pseudomonas aeruginosa, Burkholderia cenocepacia (formerly Burkholderia cepacia genomovar III), Staphylococcus aureus and Stenotrophomonas maltophilia are bacterial pathogens which are commonly found in the sputum of CF patients. A study was performed to ascertain the

John E Moore; Adrienne Shaw; Jennifer L Howard; James SG Dooley; J Stuart Elborn

2004-01-01

142

Effect of Eucalyptus Essential Oil on Respiratory Bacteria and Viruses  

Microsoft Academic Search

The activity of Eucalyptus globulus essential oil was determined for 120 isolates of Streptococcus\\u000a 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

Claudio Cermelli; Anna Fabio; Giuliana Fabio; Paola Quaglio

2008-01-01

143

First Reported Infections Caused by Three Newly Described Genera in the Family Xanthomonadaceae?  

PubMed Central

Members of the family of Xanthomonadaceae are typically characterized as environmental organisms. With the exception of Stenotrophomonas maltophilia, these organisms are infrequently implicated as human pathogens. We describe three cases of central venous catheter-associated bloodstream infections caused by Dokdonella koreensis, Aquimonas voraii, and a Luteibacter sp., all newly named genera within the family Xanthomonadaceae. The three patients all had histories of underlying hematological disorders, presented with fever, and recovered fully following treatment. These isolates required 16S rRNA gene sequencing for identification and, unlike S. maltophilia, demonstrated susceptibility to most antibiotics tested. This report represents the first description of human infections caused by these organisms.

LaSala, P. Rocco; Segal, Jonathan; Han, Faye S.; Tarrand, Jeffrey J.; Han, Xiang Y.

2007-01-01

144

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

PubMed

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

Borets'ka, M O; Kozlova, I P

2007-01-01

145

Ventilator-associated Pneumonia Caused by Potentially Drug-resistant Bacteria  

Microsoft Academic Search

To determine risk factors for ventilator-associated pneumonia (VAP) caused by potentially drug-resis- tant bacteria such as methicillin-resistant Staphylococcus aureus , Pseudomonas aeruginosa , Acineto- bacter baumannii , and\\/or Stenotrophomonas maltophilia , 135 consecutive episodes of VAP observed in a single ICU over a 25-mo period were prospectively studied. For all patients, VAP was diagnosed based on results of bronchoscopic protected

JEAN-LOUIS TROUILLET; JEAN CHASTRE; ALBERT VUAGNAT; MARIE-LAURE JOLY-GUILLOU; DANIČLE COMBAUX; MARIE-CHRISTINE DOMBRET; CLAUDE GIBERT

1998-01-01

146

Metallo Lactamase Producers in Environmental Microbiota: New Molecular Class B Enzyme in Janthinobacterium lividum  

Microsoft Academic Search

Eleven environmental samples from different sources were screened for the presence of metallo-b-lactamase- producing bacteria by using a selective enrichment medium containing a carbapenem antibiotic and subse- quently testing each isolate for production of EDTA-inhibitable carbapenemase activity. A total of 15 metallo- b-lactamase-producing isolates, including 10 Stenotrophomonas maltophilia isolates, 3 Chryseobacterium spp., one Aeromonas hydrophila isolate, and one Janthinobacterium lividum

GIAN MARIA ROSSOLINI; MARIA ADELAIDE CONDEMI; FABRIZIO PANTANELLA; JEAN-DENIS DOCQUIER; GIANFRANCO AMICOSANTE; MARIA CRISTINA THALLER

2001-01-01

147

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

Microsoft Academic Search

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

SUDARAT BOONCHAN; MARGARET L. BRITZ

2000-01-01

148

Waterborne nosocomial infections  

Microsoft Academic Search

Waterborne pathogens cause infections in health-care facilities. Despite guidelines addressing these pathogens, outbreaks\\u000a and pseudo-outbreaks continue to occur. We reviewed recent reports of infections caused by Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Chryseobacterium species, nontuberculous mycobacteria, and Legionella species. Mycobacterium avium complex (MAC) infection in HIV patients has been linked to hospital water distribution systems; molecular subtyping showed that MAC\\u000a isolates in

Cheryl Squier; Victor L. Yu; Janet E. Stout

2000-01-01

149

Airborne bacteria and antibiotic resistance genes in hospital rooms  

Microsoft Academic Search

The microbial biodiversity of bioaerosols in recently occupied hospital rooms was assessed in a pulmonology unit. Environmental\\u000a samples and isolates were also screened for antibiotics resistance genes. Biofilms from sink drains were also studied to evaluate\\u000a whether sink drains constitute a potential source of bioaerosols in this environment and a reservoir for opportunistic bacteria\\u000a and antibiotic resistance genes. Stenotrophomonas maltophilia

Yan Gilbert; Marc Veillette; Caroline Duchaine

2010-01-01

150

Antibacterial evaluation of a collection of norfloxacin and ciprofloxacin derivatives against multiresistant bacteria.  

PubMed

The objective of this study was to analyse an array of ciprofloxacin and norfloxacin derivatives in order to determine those with good activity against bacteria that already present fluoroquinolone resistance associated with mutations in the gyrA and/or parC genes. Four norfloxacin and 20 ciprofloxacin derivatives were synthesised and tested against quinolone-susceptible and -resistant Escherichia coli, Acinetobacter baumannii, Stenotrophomonas maltophilia and Staphylococcus aureus strains using a microdilution test. Among the derivatives, the 4-methyl-7-piperazine ciprofloxacin derivative showed a minimum inhibitory concentration for 50% of the organisms that was 16- and 8-fold lower than ciprofloxacin for A. baumannii and S. maltophilia, respectively. When the methyl group at position 4 in the piperazine ring was substituted by ethyl, butyl or heptyl groups, activity against A. baumannii steadily decreased. The 7-(4-methyl)-piperazine ciprofloxacin derivative (UB-8902) showed very good activity against these multiresistant microorganisms including A. baumannii and S. maltophilia. PMID:16781123

Vila, J; Sánchez-Céspedes, J; Sierra, J M; Piqueras, M; Nicolás, E; Freixas, J; Giralt, E

2006-07-01

151

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

PubMed

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

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

2012-07-01

152

Effect of eucalyptus essential oil on respiratory bacteria and viruses.  

PubMed

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

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

2008-01-01

153

Degradation of 4-nitroaniline by Stenotrophomonas strain HPC 135  

Microsoft Academic Search

A bacterial strain HPC 135 capable of growing on 4-nitroaniline (NA) as a source of carbon and energy was isolated from contaminated site after enrichment. Experiments revealed that the strain HPC 135 utilized 4NA as analyzed by high-performance liquid chromatography (HPLC). The presence of acetate as co-substrate did not affect the utilization of 4-nitroaniline by the isolate but cell growth

Asifa Qureshi; Vinita Verma; Atya Kapley; Hemant J. Purohit

2007-01-01

154

Use of 16S rRNA Gene Sequencing for Identification of Nonfermenting Gram-Negative Bacilli Recovered from Patients Attending a Single Cystic Fibrosis Center  

PubMed Central

During 1999, we used partial 16S rRNA gene sequencing for the prospective identification of atypical nonfermenting gram-negative bacilli isolated from patients attending our cystic fibrosis center. Of 1,093 isolates of nonfermenting gram-negative bacilli recovered from 148 patients, 46 (4.2%) gave problematic results with conventional phenotypic tests. These 46 isolates were genotypically identified as Pseudomonas aeruginosa (19 isolates, 12 patients), Achromobacter xylosoxidans (10 isolates, 8 patients), Stenotrophomonas maltophilia (9 isolates, 9 patients), Burkholderia cepacia genomovar I/III (3 isolates, 3 patients), Burkholderia vietnamiensis (1 isolate), Burkholderia gladioli (1 isolate), and Ralstonia mannitolilytica (3 isolates, 2 patients), a recently recognized species.

Ferroni, Agnes; Sermet-Gaudelus, Isabelle; Abachin, Eric; Quesne, Gilles; Lenoir, Gerard; Berche, Patrick; Gaillard, Jean-Louis

2002-01-01

155

Microbiological identification in cystic fibrosis patients with CFTR I1234V mutation.  

PubMed

Recurrent and chronic bacterial pulmonary infection is the major cause of morbidity and mortality in cystic fibrosis (CF). Over 6 months, 72 sputa or oropharyngeal samples were examined from 36 Arab Bedouin CF patients attending Hamad General Hospital, Doha, Qatar. More than 100 pathogens were isolated, mostly Haemophilus influenzae, Staphylococcus aureus and Pseudomonas aeruginosa. Unusual pathogens included Stenotrophomonas maltophilia, Acaligenes xylosoxidans and Mycobacterium abscessus. It is concluded that microbiological biodiversity in the lower airways of CF patients continues to be underestimated and that CF patients harbouring mucoid strains of P. aeruginosa are at a higher risk of acquiring more unusual organisms and probably have a worse prognosis. PMID:15357563

Wahab, A Abdul; Janahi, I A; Marafia, M M; El-Shafie, S

2004-08-01

156

Use of 16S rRNA gene sequencing for identification of nonfermenting gram-negative bacilli recovered from patients attending a single cystic fibrosis center.  

PubMed

During 1999, we used partial 16S rRNA gene sequencing for the prospective identification of atypical nonfermenting gram-negative bacilli isolated from patients attending our cystic fibrosis center. Of 1,093 isolates of nonfermenting gram-negative bacilli recovered from 148 patients, 46 (4.2%) gave problematic results with conventional phenotypic tests. These 46 isolates were genotypically identified as Pseudomonas aeruginosa (19 isolates, 12 patients), Achromobacter xylosoxidans (10 isolates, 8 patients), Stenotrophomonas maltophilia (9 isolates, 9 patients), Burkholderia cepacia genomovar I/III (3 isolates, 3 patients), Burkholderia vietnamiensis (1 isolate), Burkholderia gladioli (1 isolate), and Ralstonia mannitolilytica (3 isolates, 2 patients), a recently recognized species. PMID:12354883

Ferroni, Agnes; Sermet-Gaudelus, Isabelle; Abachin, Eric; Quesne, Gilles; Lenoir, Gerard; Berche, Patrick; Gaillard, Jean-Louis

2002-10-01

157

Synthesis, in vitro antimicrobial and cytotoxic activities of novel pyrimidine-benzimidazol combinations.  

PubMed

A series of novel 4-substituted-2-{[(1H-benzo[d]imidazol-2-yl)methyl] thio}-6-methylpyrimidine derivatives were designed, synthesized and evaluated for their cytotoxic activities against four human cancer cell lines and inhibitory activities against five type culture strains in vitro. Some of synthetic pyrimidine-benzimidazol combinations showed good inhibitory activities against Stenotrophomonas maltophilia, especially compounds 7b and 7c. Compounds 7a and 7d exhibited enhanced activities against MGC-803 in vitro, when compared to 5-Fu. PMID:24798098

Chen, Peng-Ju; Yang, Ang; Gu, Yi-Fei; Zhang, Xiao-Song; Shao, Kun-Peng; Xue, Deng-Qi; He, Peng; Jiang, Teng-Fei; Zhang, Qiu-Rong; Liu, Hong-Min

2014-06-15

158

Antibacterial activity of Zuccagnia punctata Cav. ethanolic extracts.  

PubMed

The present study was conducted to investigate antibacterial activity of Zuccagnia punctata ethanolic extract against 47 strains of antibiotic-resistant Gram-negative bacteria and to identify bioactive compounds. Inhibition of bacterial growth was investigated using agar diffusion, agar macrodilution, broth microdilution and bioautographic methods. Zuccagnia punctata extract was active against all assayed bacteria (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter cloacae, Serratia marcescens, Morganella morganii, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia) with minimal inhibitory concentration (MIC) values ranging from 25 to 200 microg/mL. Minimal bactericidal concentration (MBC) values were identical or two-fold higher than the corresponding MIC values. Contact bioautography, indicated that Zuccagnia punctata extracts possess one major antibacterial component against Pseudomonas aeruginosa and at least three components against. Klebsiella pneumoniae and Escherichia coli. Activity-guided fractionation of 1he ethanol extract on a silica gel column yielded a compound (2',4'-dihydroxychalcone), which exhibited strong antibacterial activity with MIC values between 0.10 and 1.00 microg/mL for Proteus mirabilis, Enterobacter cloacae, Serratia marcescens, Morganella morganii, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia. These values are lower than imipenem (0.25-16 microg/mL). Zuccagnia punctata might provide promising therapeutic agents against infections with multi-resistant Gram-negative bacteria. PMID:16137849

Zampini, Iris C; Vattuone, Marta A; Isla, Maria I

2005-12-01

159

Bacterial cis-2-unsaturated fatty acids found in the cystic fibrosis airway modulate virulence and persistence of Pseudomonas aeruginosa  

PubMed Central

There is an increasing appreciation of the polymicrobial nature of many bacterial infections such as those associated with cystic fibrosis (CF) and of the potentially important role for interspecies interactions in influencing both bacterial virulence and response to therapy. Patients with CF are often co-infected with Pseudomonas aeruginosa and other pathogens including Burkholderia cenocepacia and Stenotrophomonas maltophilia. These latter bacteria produce signal molecules of the diffusible signal factor (DSF) family, which are cis-2-unsaturated fatty acids. We have previously shown by in vitro studies that DSF from S. maltophilia leads to altered biofilm formation and increased resistance to antibiotics by P. aeruginosa; these responses of P. aeruginosa require the sensor kinase PA1396. Here we show that DSF signals are present in sputum taken from patients with CF. Presence of these DSF signals was correlated with patient colonization by S. maltophilia and/or B. cenocepacia. Analysis of 50 clinical isolates of P. aeruginosa showed that each responded to the presence of synthetic DSF by increased antibiotic resistance and these strains demonstrated little sequence variation in the PA1396 gene. In animal experiments using CF transmembrane conductance regulator knockout mice, the presence of DSF promoted P. aeruginosa persistence. Furthermore, antibiotic resistance of P. aeruginosa biofilms grown on human airway epithelial cells was enhanced in the presence of DSF. Taken together, these data provide substantial evidence that interspecies DSF-mediated bacterial interactions occur in the CF lung and may influence the efficacy of antibiotic treatment, particularly for chronic infections involving persistence of bacteria.

Twomey, Kate B; O'Connell, Oisin J; McCarthy, Yvonne; Dow, J Maxwell; O'Toole, George A; Plant, Barry J; Ryan, Robert P

2012-01-01

160

Emerging pathogens in cystic fibrosis: ten years of follow-up in a cohort of patients.  

PubMed

In patients with cystic fibrosis (CF), there is an increasing incidence of some uncommon respiratory pathogens, such as Burkholderia cepacia complex (Bcc), Stenotrophomonas maltophilia, and Achromobacter xylosoxidans. In order to evaluate the prevalence and the clinical impact of these pathogens, we retrospectively studied a total of 109 patients followed in our center from 1996 to 2006 and reviewed the results of 1,550 sputum samples. The isolation of Pseudomonas aeruginosa slightly decreased over the observed decade, whereas Staphylococcus aureus exhibited an irregular trend. Infection with Bcc reached a peak in 1998 and successively decreased to a stable 4%. S. maltophilia and A. xylosoxidans were the real emerging pathogens, since first isolation occurred in 2004; however, the percentage of infected patients remained low (7% and 3.2%, respectively) through the years. In conclusion, in our center for CF, the reduced prevalence of P. aeruginosa over the last decade has been associated with a concurrent reduction of infections by Bcc and, as compared to other centers in Italy, Europe, and the US, with a low incidence of emerging pathogens such as S. maltophilia and A. xylosoxidans. PMID:18758832

Spicuzza, L; Sciuto, C; Vitaliti, G; Di Dio, G; Leonardi, S; La Rosa, M

2009-02-01

161

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

PubMed Central

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 ?g C liter?1 than in water with AOC levels below 5 ?g 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.

van der Kooij, Dick

2013-01-01

162

Evaluation of the VITEK 2 system for the identification and susceptibility testing of three species of nonfermenting gram-negative rods frequently isolated from clinical samples.  

PubMed

VITEK 2 is a new automatic system for the identification and susceptibility testing of the most clinically important bacteria. In the present study 198 clinical isolates, including Pseudomonas aeruginosa (n = 146), Acinetobacter baumannii (n = 25), and Stenotrophomonas maltophilia (n = 27) were evaluated. Reference susceptibility testing of cefepime, cefotaxime, ceftazidime, ciprofloxacin, gentamicin, imipenem, meropenem, piperacillin, tobramycin, levofloxacin (only for P. aeruginosa), co-trimoxazole (only for S. maltophilia), and ampicillin-sulbactam and tetracycline (only for A. baumannii) was performed by microdilution (NCCLS guidelines). The VITEK 2 system correctly identified 91.6, 100, and 76% of P. aeruginosa, S. maltophilia, and A. baumannii isolates, respectively, within 3 h. The respective percentages of essential agreement (to within 1 twofold dilution) for P. aeruginosa and A. baumannii were 89.0 and 88.0% (cefepime), 91.1 and 100% (cefotaxime), 95.2 and 96.0% (ceftazidime), 98.6 and 100% (ciprofloxacin), 88.4 and 100% (gentamicin), 87.0 and 92.0% (imipenem), 85.0 and 88.0% (meropenem), 84.2 and 96.0% (piperacillin), and 97.3 and 80% (tobramycin). The essential agreement for levofloxacin against P. aeruginosa was 86.3%. The percentages of essential agreement for ampicillin-sulbactam and tetracycline against A. baumannii were 88.0 and 100%, respectively. Very major errors for P. aeruginosa (resistant by the reference method, susceptible with the VITEK 2 system [resistant to susceptible]) were noted for cefepime (0.7%), cefotaxime (0.7%), gentamicin (0.7%), imipenem (1.4%), levofloxacin (2.7%), and piperacillin (2.7%) and, for one strain of A. baumannii, for imipenem. Major errors (susceptible to resistant) were noted only for P. aeruginosa and cefepime (2.0%), ceftazidime (0.7%), and piperacillin (3.4%). Minor errors ranged from 0.0% for piperacillin to 22.6% for cefotaxime against P. aeruginosa and from 0.0% for piperacillin and ciprofloxacin to 20.0% for cefepime against A. baumannii. The VITEK 2 system provided co-trimoxazole MICs only for S. maltophilia; no very major or major errors were obtained for co-trimoxazole against this species. It is concluded that the VITEK 2 system allows the rapid identification of S. maltophilia and most P. aeruginosa and A. baumannii isolates. The VITEK 2 system can perform reliable susceptibility testing of many of the antimicrobial agents used against P. aeruginosa and A. baumannii. It would be desirable if new versions of the VITEK 2 software were able to determine MICs and the corresponding clinical categories of agents active against S. maltophilia. PMID:11526158

Joyanes, P; del Carmen Conejo, M; Martínez-Martínez, L; Perea, E J

2001-09-01

163

Chemical composition of endemic Scorzonera sandrasica and studies on the antimicrobial activity against multiresistant bacteria.  

PubMed

The present study describes the antimicrobial activity and chemical composition of Scorzonera sandrasica Hartvig et Strid (Family Asteraceae), endemic to Turkey. The antimicrobial activity of the hexane, chloroform, ethyl acetate, and ethanol extracts of the aerial parts of S. sandrasica was evaluated against microorganisms, including multiresistant bacteria, using a paper disc diffusion method. The chemical composition of the chloroform extract of the plant was determined by gas chromatography and gas chromatography-mass spectrometry. The major compounds of the chloroform extract of the plant were caryophyllene oxide (19.7%), manoyl oxide (16.5%), and manool (11.3%), respectively. The extracts had antibacterial activity; however, no antifungal activity was observed against the two fungi. In particular, the ethanol and chloroform extracts exhibited significant activity against multiresistant strains of Stenotrophomonas maltophilia. PMID:20438328

Ugur, Aysel; Sarac, Nurdan; Ceylan, Ozgur; Duru, M Emin; Beyatli, Yavuz

2010-06-01

164

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

PubMed

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

Lee, Yoonjin

2013-09-01

165

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

PubMed Central

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.

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

2007-01-01

166

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

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

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

2013-01-01

167

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

PubMed

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

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

2006-12-15

168

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

PubMed

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

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

2014-06-01

169

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

PubMed

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

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

2014-01-01

170

Emerging and unusual gram-negative infections in cystic fibrosis.  

PubMed

People with cystic fibrosis (CF) have chronic airway infection and frequent exposure to antibiotics, which often leads to the emergence of resistant organisms. In addition to the development of multiresistance in common CF pathogens such as Pseudomonas aeruginosa, several newer, inherently resistant gram-negative species are becoming more common, including Burkholderia cepacia complex, Stenotrophomonas maltophilia, Achromobacter (Alcaligenes) xylosoxidans, certain Ralstonia species, and those within the new genus Pandoraea. Many of these are closely related and have similar phenotypes, making accurate laboratory identification challenging. Although their role in contributing to pulmonary disease in CF is not clear, some, such as those of the B. cepacia complex, are clearly linked to an adverse prognosis, and both treatment and infection control issues can pose a real challenge. PMID:17562501

Davies, Jane C; Rubin, Bruce K

2007-06-01

171

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

PubMed Central

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.

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

2012-01-01

172

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

NASA Astrophysics Data System (ADS)

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.

Baker, Paul W.; Leff, Laura G.

2006-01-01

173

Effects of pathology dyes on Raman bone spectra  

NASA Astrophysics Data System (ADS)

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.

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

2013-05-01

174

Cloning, expression and crystallization of heterotetrameric sarcosine oxidase from Pseudomonas maltophilia  

Microsoft Academic Search

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 one-carbon metabolic pool. In addition to four different subunits, TSOX contains three coenzymes (FAD, FMN, and NAD) and a binding site for tetrahydrofolate, the coenzyme acceptor of the oxidized methyl group

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

2005-01-01

175

AFB1 BioDegradation by a New Strain - Stenotrophomonas. sp  

Microsoft Academic Search

The paper was to find the bacteria to degrade aflatoxin B1 (AFB1) and realize the application of biological degradation on AFB1. Using cumarin as the carbon source and energy on the first screening, then the ten strains which were first screened out were taken to degrade AFB1 100 ?g kg?1. Strain NMO-3 was screened out of ten strains, the degradation

Zhi-hong LIANG; Jun-xia LI; Yun-long HE; Shu GUAN; Nin WANG; Cheng JI; Tian-gui NIU

2008-01-01

176

[Phenotypic and genotypic characteristics of non fermenting atypical strains recovered from cystic fibrosis patients].  

PubMed

We used partial 16S rRNA gene (16S DNA) sequencing for the prospective identification of nonfermenting Gram-negative bacilli recovered from patients attending our cystic fibrosis center (hôpital Necker-Enfants malades), which gave problematic results with conventional phenotypic tests. During 1999, we recovered 1093 isolates of nonfermenting Gram-negative bacilli from 702 sputum sampled from 148 patients. Forty-six of these isolates (27 patients) were not identified satisfactorily in routine laboratory tests. These isolates were identified by 16S DNA sequencing as Pseudomonas aeruginosa (19 isolates, 12 patients), Achromobacter xylosoxidans (10 isolates, 8 patients), Stenotrophomonas maltophilia (9 isolates, 9 patients), Burkholderia cepacia genomovar I/III (3 isolates, 3 patients), Burkholderia vietnamiensis (1 isolate), Burkholderia gladioli (1 isolate) and Ralstonia mannitolilytica (3 isolates, 2 patients). Fifteen isolates (33%) were resistant to all antibiotics in routine testing. Sixteen isolates (39%) resistant to colistin were recovered on B. cepacia-selective medium: 2 P. aeruginosa, 3 A. xylosoxidans, 3 S. maltophilia and the 8 Burkholderia--Ralstonia isolates. The API 20NE system gave no identification for 35 isolates and misidentified 11 isolates (2 P. aeruginosa, 2 A. xylosoxidans and 1 S. maltophilia classified as B. cepacia ). Control measures and/or treatment were clearly improved as a result of 16S DNA sequencing in three of these cases. This study confirms the weakness of phenotypic methods for identification of atypical nonfermenting Gram-negative bacilli recovered from cystic fibrosis patients. The genotypic methods, such as 16S DNA sequencing which allows identification of strains in routine practice, appears to have a small, but significant impact on the clinical management of CF patients. PMID:12948761

Ferroni, A; Sermet-Gaudelus, I; Abachin, E; Quesnes, G; Lenoir, G; Berche, P; Gaillard, J L

2003-09-01

177

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

PubMed Central

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.

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

2013-01-01

178

Esculentin-2CHa: a host-defense peptide with differential cytotoxicity against bacteria, erythrocytes and tumor cells.  

PubMed

The host-defense peptide, esculentin-2CHa (GFSSIFRGVA(10)KFASKGLGK D(20)LAKLGVDLVA(30) CKISKQC) shows potent (MIC?6 ?M) growth inhibitory activity against clinical isolates of multidrug-resistant strains of Staphylococcus aureus, Acinetobacter baumannii, and Stenotrophomonas maltophilia and differential cytotoxic activity against human erythrocytes (LC(50)=150 ?M) and human non-small cell lung adenocarcinoma A549 cells (LC(50)=10 ?M). Esculentin-2CHa significantly (P<0.01) stimulates the release of the anti-inflammatory cytokine IL-10 by mouse lymphoid cells and elevates its production after stimulation with concanavalin A and significantly (P<0.05) stimulates TNF-? production by peritoneal macrophages. Effects on IL-6 and IL-1? production were not significant. Removal of the hydrophobic N-terminal hexapeptide (GFSSIF) from esculentin-2CHa results in abolition of growth inhibitory activity against S. aureus and cytotoxic activity against erythrocytes and A549 cells as well as a marked (?16-fold) reduction in potency against A. baumannii and S. maltophilia. The primary structure of esculentin-2 has been poorly conserved between frog species but evolutionary pressure has acted to maintain the hydrophobic character of this N-terminal hexapeptide sequence. Removal of the cyclic C-terminal domain (CKISKQC) and replacement of the Cys(31) and Cys(37) residues by serine resulted in appreciable decreases in cytotoxicity against all microorganisms and against mammalian cells. The more cationic [D20K, D27K] analog showed a modest increase in potency against all microorganisms (up to 4-fold) but a marked increase in cytotoxicity against erythrocytes (LC(50)=11 ?M) and A549 cells (LC(50)=3 ?M). PMID:23159562

Attoub, Samir; Mechkarska, Milena; Sonnevend, Agnes; Radosavljevic, Gordana; Jovanovic, Ivan; Lukic, Miodrag L; Conlon, J Michael

2013-01-01

179

Evaluation of the DiversiLab System for Detection of Hospital Outbreaks of Infections by Different Bacterial Species ?  

PubMed Central

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

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

2010-01-01

180

Cathelicidin Peptides Inhibit Multiply Antibiotic-Resistant Pathogens from Patients with Cystic Fibrosis  

PubMed Central

Endogenous peptide antibiotics are under investigation as inhaled therapeutic agents for cystic fibrosis (CF) lung disease. The bactericidal activities of five cathelicidin peptides (LL37 [human], CAP18 [rabbit], mCRAMP [mouse], rCRAMP [rat], and SMAP29 [sheep]), three novel alpha-helical peptides derived from SMAP29 and termed ovispirins (OV-1, OV-2, and OV-3), and two derivatives of CAP18 were tested by broth microdilution assays. Their MICs were determined for multiply antibiotic-resistant Pseudomonas aeruginosa (n = 24), Burkholderia cepacia (n = 5), Achromobacter xylosoxidans (n = 5), and Stenotrophomonas maltophilia (n = 5) strains isolated from CF patients. SMAP29 was most active and inhibited mucoid and nonmucoid P. aeruginosa strains (MIC, 0.06 to 8 ?g/ml). OV-1, OV-2, and OV-3 were nearly as active (MIC, 0.03 to 16 ?g/ml), but CAP18 (MIC, 1.0 to 32 ?g/ml), CAP18-18 (MIC, 1.0 to >32 ?g/ml), and CAP18-22 (MIC, 0.5 to 32 ?g/ml) had variable activities. LL37, mCRAMP, and rCRAMP were least active against the clinical isolates studied (MIC, 1.0 to >32 ?g/ml). Peptides had modest activities against S. maltophilia and A. xylosoxidans (MIC range, 1.0 to > 32 ?g/ml), but none inhibited B. cepacia. However, CF sputum inhibited the activity of SMAP29 substantially. The effects of peptides on bacterial cell membranes and eukaryotic cells were examined by scanning electron microscopy and by measuring transepithelial cell resistance, respectively. SMAP29 caused the appearance of bacterial membrane blebs within 1 min, killed P. aeruginosa within 1 h, and caused a dose-dependent, reversible decrease in transepithelial resistance within 5 h. The tested cathelicidin-derived peptides represent a novel class of antimicrobial agents and warrant further development as prophylactic or therapeutic agents for CF lung disease.

Saiman, Lisa; Tabibi, Setareh; Starner, Timothy D.; San Gabriel, Pablo; Winokur, Patricia L.; Jia, Hong Peng; McCray, Paul B.; Tack, Brian F.

2001-01-01

181

Metallo-?-Lactamase Producers in Environmental Microbiota: New Molecular Class B Enzyme in Janthinobacterium lividum  

PubMed Central

Eleven environmental samples from different sources were screened for the presence of metallo-?-lactamase-producing bacteria by using a selective enrichment medium containing a carbapenem antibiotic and subsequently testing each isolate for production of EDTA-inhibitable carbapenemase activity. A total of 15 metallo-?-lactamase-producing isolates, including 10 Stenotrophomonas maltophilia isolates, 3 Chryseobacterium spp., one Aeromonas hydrophila isolate, and one Janthinobacterium lividum isolate (a species in which production of metallo-?-lactamase activity was not previously reported), were obtained from 8 samples. In the J. lividum isolate, named JAC1, production of metallo-?-lactamase activity was elicited upon exposure to ?-lactams. Screening of a JAC1 genomic library for clones showing a reduced imipenem susceptibility led to the isolation of a metallo-?-lactamase determinant encoding a new member (named THIN-B) of the highly divergent subclass B3 lineage of metallo-?-lactamases. THIN-B is most closely related (35.6% identical residues) to the L1 enzyme of S. maltophilia and more distantly related to the FEZ-1 enzyme of Legionella gormanii (27.8% identity) and to the GOB-1 enzyme of Chryseobacterium meningosepticum (24.2% identity). Sequences related to blaTHIN-B, and inducible production of metallo-?-lactamase activity, were also detected in the J. lividum type strain DSM1522. Expression of the blaTHIN-B gene in Escherichia coli resulted in decreased susceptibility to several ?-lactams, including penicillins, cephalosporins (including cephamycins and oxyimino cephalosporins), and carbapenems, revealing a broad substrate specificity of the enzyme. The results of this study indicated that metallo-?-lactamase-producing bacteria are widespread in the environment and identified a new molecular class B enzyme in the environmental species J. lividum.

Rossolini, Gian Maria; Condemi, Maria Adelaide; Pantanella, Fabrizio; Docquier, Jean-Denis; Amicosante, Gianfranco; Thaller, Maria Cristina

2001-01-01

182

In vitro activity of tigecycline against isolates collected from complicated skin and skin structure infections and intra-abdominal infections in Africa and Middle East countries: TEST 2007-2012.  

PubMed

Complicated skin and skin structure infections (cSSSIs) and intra-abdominal infections (IAIs) are problematic due to decreasing therapeutic options available against multidrug-resistant pathogens common among these types of infections. A total of 2245 isolates from African and the Middle Eastern (AfME) countries were collected to determine in vitro activity for tigecycline and comparators during 2007-2012 as part of the Tigecycline Evaluation Surveillance Trial program. Tigecycline was launched in the AfME in 2007 and remains active against a wide range of targeted pathogens worldwide. Isolates were recovered from cSSSI (1990) and IAI (255) from 38 sites in 11 AfME countries. Staphylococcus aureus was the most common species from cSSSI (27.9%), and the methicillin-resistant S. aureus rate was 25%. Enterococcus spp. (7.1%) and Streptococcus agalactiae (2.9%) were other common Gram-positive pathogens represented. Enterobacter spp. (14.5%), Pseudomonas aeruginosa (13.9%), Escherichia coli (11.4%), Klebsiella spp. (10.9%), and Acinetobacter spp. (7.2 %) were the most common Gram-negative species collected. Tigecycline MIC90 values were 0.25 ?g/mL against S. aureus. E. coli and Enterobacter spp. had tigecycline MIC90 values of 1 and 2 ?g/mL, respectively. E. coli was the most frequently collected species from IAI (28.3%), followed by Klebsiella spp. (20.8%), Enterococcus spp. (11.8%), and Stenotrophomonas maltophilia (6.3%). Isolates collected from IAI had the following tigecycline MIC90 values: E. coli (1 ?g/mL), Klebsiella spp. and other Enterobacteriaceae (2 ?g/mL), Enterococcus spp. (0.25 ?g/mL), and S. maltophilia (1 ?g/mL). Tigecycline in vitro activity was observed against a broad spectrum of bacterial species, including strains resistant to other antimicrobial classes. PMID:24582580

Renteria, M I; Biedenbach, D J; Bouchillon, S K; Hoban, D J; Raghubir, N; Sajben, P; Mokaddas, E

2014-05-01

183

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

SciTech Connect

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.

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

2000-03-01

184

Emergence of Imipenem-Resistant Gram-Negative Bacilli in Intestinal Flora of Intensive Care Patients  

PubMed Central

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

Angebault, Cecile; Barbier, Francois; Hamelet, Emilie; Defrance, Gilles; Ruppe, Etienne; Bronchard, Regis; Lepeule, Raphael; Lucet, Jean-Christophe; El Mniai, Assiya; Wolff, Michel; Montravers, Philippe; Plesiat, Patrick; Andremont, Antoine

2013-01-01

185

Capillary electrophoresis-single-strand conformation polymorphism analysis for rapid identification of Pseudomonas aeruginosa and other gram-negative nonfermenting bacilli recovered from patients with cystic fibrosis.  

PubMed

We used capillary electrophoresis-single-strand conformation polymorphism (CE-SSCP) analysis of PCR-amplified 16S rRNA gene fragments for rapid identification of Pseudomonas aeruginosa and other gram-negative nonfermenting bacilli isolated from patients with cystic fibrosis (CF). Target sequences were amplified by using forward and reverse primers labeled with various fluorescent dyes. The labeled PCR products were denatured by heating and separated by capillary gel electrophoresis with an automated DNA sequencer. Data were analyzed with GeneScan 672 software. This program made it possible to control lane-to-lane variability by standardizing the peak positions relative to internal DNA size markers. Thirty-four reference strains belonging to the genera Pseudomonas, Brevundimonas, Burkholderia, Comamonas, Ralstonia, Stenotrophomonas, and Alcaligenes were tested with primer sets spanning 16S rRNA gene regions with various degrees of polymorphism. The best results were obtained with the primer set P11P-P13P, which spans a moderately polymorphic region (Escherichia coli 16S rRNA positions 1173 to 1389 [M. N. Widjojoatmodjo, A. C. Fluit, and J. Verhoef, J. Clin. Microbiol. 32:3002-3007, 1994]). This primer set differentiated the main CF pathogens from closely related species but did not distinguish P. aeruginosa from Pseudomonas alcaligenes-Pseudomonas pseudoalcaligenes and Alcaligenes xylosoxidans from Alcaligenes denitrificans. Two hundred seven CF clinical isolates (153 of P. aeruginosa, 26 of Stenotrophomonas maltophilia, 15 of Burkholderia spp., and 13 of A. xylosoxidans) were tested with P11P-P13P. The CE-SSCP patterns obtained were identical to those for the corresponding reference strains. Fluorescence-based CE-SSCP analysis is simple to use, gives highly reproducible results, and makes it possible to analyze a large number of strains. This approach is suited for the rapid identification of the main gram-negative nonfermenting bacilli encountered in CF. PMID:10488211

Ghozzi, R; Morand, P; Ferroni, A; Beretti, J L; Bingen, E; Segonds, C; Husson, M O; Izard, D; Berche, P; Gaillard, J L

1999-10-01

186

Changes in gram negative microorganisms' resistance pattern during 4 years period in a referral teaching hospital; a surveillance study  

PubMed Central

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

2012-01-01

187

Antimicrobial multiresistance in bacteria isolated from freshwater Chilean salmon farms.  

PubMed

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

Mirand, Claudio D; Zemelman, Raul

2002-07-01

188

Stent hypersensitivity and infection in sinus cavities  

PubMed Central

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

Soufras, George D.; Hahalis, George

2013-01-01

189

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

PubMed Central

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

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

2011-01-01

190

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

PubMed Central

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.

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

2001-01-01

191

[Bacterial isolates from respiratory samples of pediatric patients with cystic fibrosis and their distribution by ages].  

PubMed

The bacterial isolates from respiratory samples of 50 pediatric patients with cystic fibrosis, their distribution by ages and antimicrobial resistance pattern as well as the intermittence of isolations and coinfections, were investigated. Staphylococcus aureus was isolated in 72 % of patients, followed by Pseudomonas aeruginosa (58 %), Haemophilus. influenzae (56 %), and the Burkholderia cepacia complex (12 %). The frequency of resistance of P. aeruginosa isolates to ?-lactam antibiotics was low (13.8 %). Fifty percent of S. aureus isolates was methicillin-resistant, and 57.1 % of H. influenza was ampicillin resistant due to ?-lactamase production. In children under 4 years-old, S. aureus was predominant, followed by P. aeruginosa and H. influenzae. This order of predominance was observed in all the groups studied, except in that of children between 10 and 14 years-old. Stenotrophomonas maltophilia and Achromobacter xylosoxidans isolates were intermittent and accompanied by other microorganisms. Finally, we observed a great variety of bacterial species, which imposes stringent performance requirements for microbiological studies in all respiratory samples of these patients. PMID:23560788

Busquets, Natalia P; Baroni, María R; Ochoteco, María C; Zurbriggen, María L; Virgolini, Stella; Meneghetti, Fernando G

2013-01-01

192

Time-kill studies of tea tree oils on clinical isolates.  

PubMed

Tea tree oil has recently emerged as an effective topical antimicrobial agent active against a wide range of organisms. Tea tree oil may have a clinical application in both the hospital and community, especially for clearance of methicillin-resistant Staphylococcus aureus (MRSA) carriage or as a hand disinfectant to prevent cross-infection with Gram-positive and Gramnegative epidemic organisms. Our study, based on the time-kill approach, determined the kill rate of tea tree oil against several multidrug-resistant organisms, including MRSA, glycopeptide-resistant enterococci, aminoglycoside-resistant klebsiellae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia, and also against sensitive microorganisms. The study was performed with two chemically different tea tree oils. One was a standard oil and the other was Clone 88 extracted from a specially bred tree, which has been selected and bred for increased activity and decreased skin irritation. Our results confirm that the cloned oil had increased antimicrobial activity when compared with the standard oil. Most results indicated that the susceptibility pattern and Gram reaction of the organism did not influence the kill rate. A rapid killing time (less than 60 min) was achieved with both tea tree oils with most isolates, but MRSA was killed more slowly than other organisms. PMID:10797086

May, J; Chan, C H; King, A; Williams, L; French, G L

2000-05-01

193

Prevalence and antimicrobial susceptibility of extended-spectrum beta-lactamase-producing bacteria in intensive care units of Sanandaj general hospitals (Kurdistan, Iran).  

PubMed

This study focused on analyzing the spread of extended-spectrum beta-lactamase (ESBL) enzymes among Gram-negative bacteria at intensive care units (ICUs). Between January 2007 and January 2008, 301 consecutive clinical isolates of Gram-negative type were isolated. Of these, 66 strains were collected from patients in ICUs in two major hospitals in Sanandaj (Kurdistan, Iran). The isolates were identified, tested for antimicrobial susceptibility, and analyzed for the presence of ESBL using the double-disk synergy test. Isolates with a positive ESBL phenotype were subjected to PCR for SHV, TEM, OXA and CTX-M beta-lactamase gene families. Sixty-six Gram-negative bacteria were isolated from clinical samples of 66 ICU patients. These isolates included 16 Escherichia coli, 28 Enterobacter spp., 5 Pseudomonas spp., 10 Klebsiella pneumoniae, 3 Serratia marcescens and 1 Stenotrophomonas maltophilia. Twenty-three (34.85%) of these isolates were ESBL producing. The ESBL genes detected were SHV, TEM, OXA-1, OXA-2 and CTX-M. The results show the presence of ESBL genes among Gram-negative bacteria in the ICU setting of Sanandaj's hospitals. There is a need to institute a strict hospital infection control policy and regular surveillance of bacterial resistance to antimicrobial agents. PMID:19521074

Ramazanzadeh, Rashid; Chitsaz, Mohsen; Bahmani, Nasrin

2009-01-01

194

Stent hypersensitivity and infection in sinus cavities.  

PubMed

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

Kounis, Nicholas G; Soufras, George D; Hahalis, George

2013-01-01

195

Genetic Diversity and Phylogeny of Antagonistic Bacteria against Phytophthora nicotianae Isolated from Tobacco Rhizosphere.  

PubMed

The genetic diversity of antagonistic bacteria from the tobacco rhizosphere was examined by BOXAIR-PCR, 16S-RFLP, 16S rRNA sequence homology and phylogenetic analysis methods. These studies revealed that 4.01% of the 6652 tested had some inhibitory activity against Phytophthora nicotianae. BOXAIR-PCR analysis revealed 35 distinct amplimers aligning at a 91% similarity level, reflecting a high degree of genotypic diversity among the antagonistic bacteria. A total of 25 16S-RFLP patterns were identified representing over 33 species from 17 different genera. Our results also found a significant amount of bacterial diversity among the antagonistic bacteria compared to other published reports. For the first time; Delftia tsuruhatensis, Stenotrophomonas maltophilia, Advenella incenata, Bacillus altitudinis, Kocuria palustris, Bacillus licheniformis, Agrobacterium tumefaciens and Myroides odoratimimus are reported to display antagonistic activity towards Phytophthora nicotianae. Furthermore, the majority (75%) of the isolates assayed for antagonistic activity were Gram-positives compared to only 25% that were Gram-negative bacteria. PMID:21686169

Jin, Fengli; Ding, Yanqin; Ding, Wei; Reddy, M S; Fernando, W G Dilantha; Du, Binghai

2011-01-01

196

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

PubMed Central

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

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

2013-01-01

197

Role of a moderately halophilic bacterial consortium in the biodegradation of polyaromatic hydrocarbons.  

PubMed

Polycyclic aromatic hydrocarbons are ubiquitous pollutants in the environment, and most high molecular weight PAHs cause mutagenic, teratogenic and potentially carcinogenic effects. While several strains have been identified that degrade PAHs, the present study is focused on the degradation of PAHs in a marine environment by a moderately halophilic bacterial consortium. The bacterial consortium was isolated from a mixture of marine water samples collected from seven different sites in Chennai, India. The low molecular weight (LMW) PAHs phenanthrene and fluorine, and the high molecular weight (HMW) PAHs pyrene and benzo(e)pyrene were selected for the degradation study. The consortium metabolized both LMW and HMW PAHs. The consortium was also able to degrade PAHs present in crude oil-contaminated saline wastewater. The bacterial consortium was able to degrade 80% of HMW PAHs and 100% of LMW PAHs in the saline wastewater. The strains present in the consortium were identified as Ochrobactrum sp., Enterobacter cloacae and Stenotrophomonas maltophilia. This study reveals that these bacteria have the potential to degrade different PAHs in saline wastewater. PMID:18995870

Arulazhagan, P; Vasudevan, N

2009-02-01

198

Analysis of community structure of a microbial consortium capable of degrading benzo(a)pyrene by DGGE.  

PubMed

A microbial consortium was obtained by enrichment culture of sea water samples collected from Botan oil port in Xiamen, China, using the persistent high concentration of a mixture of polycyclic aromatic hydrocarbons enrichment strategy. Denaturing gradient gel electrophoresis (DGGE) was used to investigate the bacterial composition and community dynamic changes based on PCR amplification of 16S rRNA genes during batch culture enrichment. Using the spray-plate method, three bacteria, designated as BL01, BL02 and BL03, which corresponded to the dominant bands in the DGGE profiles, were isolated from the consortium. Sequence analysis showed that BL01, BL02 and BL03 were phylogenetically close to Ochrobactrum sp., Stenotrophomonas maltophilia and Pseudomonas fluorescens, respectively. The degradation of benzo(a)pyrene (BaP), a model high-molecular-weight polycyclic aromatic hydrocarbon (HMW PAH) compound was investigated using individual isolates, a mixture of the three isolates, and the microbial consortium (BL) originally isolated from the oil port sea water. Results showed that the order of degradative ability was BL>the mixture of the three isolates>individual isolates. BL degraded 44.07% of the 10 ppm BaP after 14 days incubation, which showed the highest capability for HMW PAH compound degradation.Our results revealed that this high selective pressure strategy was feasible and effective in enriching the HMW PAH-degraders from the original sea water samples. PMID:19409577

Luo, Y R; Tian, Y; Huang, X; Yan, C L; Hong, H S; Lin, G H; Zheng, T L

2009-08-01

199

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

PubMed Central

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 ?-lactamase showed the presence of CTX-M-15 ?-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.

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

2012-01-01

200

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

PubMed Central

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

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

2009-01-01

201

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

PubMed

A continuously stirred tank bioreactor (CSTR) was used to optimize feasible and reliable bioprocess system in order to treat hydrocarbon-rich industrial wastewaters. A successful bioremediation was developed by an efficient acclimatized microbial consortium. After an experimental period of 225 days, the process was shown to be highly efficient in decontaminating the wastewater. The performance of the bioaugmented reactor was demonstrated by the reduction of COD rates up to 95%. The residual total petroleum hydrocarbon (TPH) decreased from 320 mg TPH l(-1) to 8 mg TPH l(-1). Analysis using gas chromatography-mass spectrometry (GC-MS) identified 26 hydrocarbons. The use of the mixed cultures demonstrated high degradation performance for hydrocarbons range n-alkanes (C10-C35). Six microbial isolates from the CSTR were characterized and species identification was confirmed by sequencing the 16S rRNA genes. The partial 16S rRNA gene sequences demonstrated that 5 strains were closely related to Aeromonas punctata (Aeromonas caviae), Bacillus cereus, Ochrobactrum intermedium, Stenotrophomonas maltophilia and Rhodococcus sp. The 6th isolate was affiliated to genera Achromobacter. Besides, the treated wastewater could be considered as non toxic according to the phytotoxicity test since the germination index of Lepidium sativum ranged between 57 and 95%. The treatment provided satisfactory results and presents a feasible technology for the treatment of hydrocarbon-rich wastewater from petrochemical industries and petroleum refineries. PMID:21419572

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

2011-05-15

202

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

PubMed Central

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

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

1996-01-01

203

Susceptibility to levofloxacin of clinical isolates of bacteria from intensive care and haematology/oncology patients in Switzerland: a multicentre study.  

PubMed

The objective of this study was to examine the susceptibility of clinical isolates to levofloxacin, a fluoroquinolone with extended activity against Gram-positive bacteria, and other antibiotics in 12 Swiss clinical microbiology laboratories using the NCCLS disc diffusion technique. Isolates were prospectively collected from intensive care units (ICUs (59%), oncology wards (7%) and other units with haematology/oncology patients (34%) from June 1995 to March 1996. The levofloxacin breakpoints used were as recommended by the manufacturer. A total of 310 Gram-positive and 580 Gram-negative isolates from the respiratory tract (36%), skin/wounds (12%), blood (16%), urine (17%) and other sources (19%) were tested. The percentage of isolates susceptible to levofloxacin was 100% for Enterococcus spp. (38 strains), Streptococcus agalactiae (13), Streptococcus pneumoniae (65), Acinetobacter spp. (11), Citrobacter diversus (6), Citrobacter freundii (17), Klebsiella oxytoca (39), Morganella morganii (16), Proteus mirabilis (20), Proteus vulgaris (23), Serratia spp. (19), Stenotrophomonas maltophilia (10) and Haemophilus influenzae (41). The percentage of isolates susceptible to levofloxacin for Staphylococcus aureus (95 strains, including 2% MRSA) was 94%, coagulase-negative staphylococci (85) 65%, Enterobacter spp. (75) 99%, Escherichia coli (111) 97%, Klebsiella pneumoniae (45) 98% and Pseudomonas aeruginosa (124) 87%. In conclusion, levofloxacin is a new fluoroquinolone to which the most common clinical isolates in Switzerland are susceptible. The susceptibility of Enterococcus spp. and S. pneumoniae to levofloxacin was particularly remarkable. This compound appears to be a promising therapeutic alternative for the treatment of Gram-positive infections. PMID:10404338

Siegrist, H H; Nepa, M C; Jacquet, A

1999-06-01

204

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

PubMed

The chromosomal ampR(Xc) -bla(Xc) module is essential for the ?-lactam resistance of Xanthomonas campestris pv. campestris. Bla(Xc) ?-lactamase is expressed at a high basal level in the absence of an inducer and its expression can be further induced by ?-lactam. In enterobacteria, ampG encodes an inner membrane facilitator involved in the recycling of murein degradation compounds. An isogenic ampG mutant (XcampG) of X. campestris pv. campestris str. 17 (Xc17) was constructed to investigate the link between murein recycling and bla(Xc) expression. Our data demonstrate that (1) XcampG is susceptible to ?-lactam antibiotics; (2) AmpG(Xc) is essential for expression of bla(Xc) ; (3) AmpGs of Xc17, Stenotrophomonas maltophilia KJ (SmKJ) and Escherichia coli DH5? can complement the defect of XcampG; (4) overexpression of AmpG(X) (c) significantly increased bla(Xc) expression; and (5) AmpG(Xc) from Xc17 is able to restore ?-lactamase induction of the ampN(Xc) -ampG(Xc) double mutant of SmKJ. In Xc17, ampG(Xc) can be expressed from the promoter residing in the intergenic region of ampN(Xc) -ampG(Xc) and the expression is independent of ?-lactam induction. AmpN, which is required for ?-lactamases induction in SmKJ, is not required for the ?-lactam antibiotic resistance of Xc17. PMID:23278458

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

2013-03-01

205

Characterization and sequence of the Chryseobacterium (Flavobacterium) meningosepticum carbapenemase: a new molecular class B beta-lactamase showing a broad substrate profile.  

PubMed Central

The metallo-beta-lactamase produced by Chryseobacterium (formerly Flavobacterium) meningosepticum, which is the flavobacterial species of greatest clinical relevance, was purified and characterized. The enzyme, named BlaB, contains a polypeptide with an apparent Mr of 26000, and has a pI of 8.5. It hydrolyses penicillins, cephalosporins (including cefoxitin), carbapenems and 6-beta-iodopenicillanate, a mechanism-based inactivator of active-site serine beta-lactamases. The enzyme was inhibited by EDTA, 1-10 phenanthroline and pyridine-2,6-dicarboxylic acid, with different inactivation parameters for each chelating agent. The C. meningosepticum blaB gene was cloned and sequenced. According to the G+C content and codon usage, the blaB gene appeared to be endogenous to the species. The BlaB enzyme showed significant sequence similarity to other class B beta-lactamases, being overall more similar to members of subclass B1, which includes the metallo-enzymes of Bacillus cereus (Bc-II) and Bacteroides fragilis (CcrA) and the IMP-1 enzyme found in various microbial species, and more distantly related to the metallo-beta-lactamases of Aeromonas spp. (CphA, CphA2 and ImiS) and of Stenotrophomonas maltophilia (L1).

Rossolini, G M; Franceschini, N; Riccio, M L; Mercuri, P S; Perilli, M; Galleni, M; Frere, J M; Amicosante, G

1998-01-01

206

Effects of a sulfonylurea herbicide on the soil bacterial community.  

PubMed

Sulfonylurea herbicides are widely used on a wide range of crops to control weeds. Chevalier® OnePass herbicide is a sulfonylurea herbicide intensively used on cereal crops in Algeria. No information is yet available about the biodegradation of this herbicide or about its effect on the bacterial community of the soil. In this study, we collected an untreated soil sample, and another sample was collected 1 month after treatment with the herbicide. Using a high-resolution melting DNA technique, we have shown that treatment with Chevalier® OnePass herbicide only slightly changed the composition of the whole bacterial community. Two hundred fifty-nine macroscopically different clones were isolated from the untreated and treated soil under both aerobic and microaerobic conditions. The strains were identified by sequencing a conserved fragment of the 16S rRNA gene. The phylogenetic trees constructed using the sequencing results confirmed that the bacterial populations were similar in the two soil samples. Species belonging to the Lysinibacillus, Bacillus, Pseudomonas, and Paenibacillus genera were the most abundant species found. Surprisingly, we found that among ten strains isolated from the treated soil, only six were resistant to the herbicide. Furthermore, bacterial overlay experiments showed that only one resistant strain (related to Stenotrophomonas maltophilia) allowed all the sensitive strains tested to grow in the presence of the herbicide. The other resistant strains allowed only certain sensitive strains to grow. On the basis of these results, we propose that there must be several biodegradation pathways for this sulfonylurea herbicide. PMID:24420563

Arabet, Dallel; Tempel, Sébastien; Fons, Michel; Denis, Yann; Jourlin-Castelli, Cécile; Armitano, Joshua; Redelberger, David; Iobbi-Nivol, Chantal; Boulahrouf, Abderrahmane; Méjean, Vincent

2014-04-01

207

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

PubMed Central

ABSTRACT A method for use in high-throughput screening of bacteria for the production of long-chain hydrocarbons and ketones by monitoring fluorescent light emission in the presence of Nile red is described. Nile red has previously been used to screen for polyhydroxybutyrate (PHB) and fatty acid esters, but this is the first report of screening for recombinant bacteria making hydrocarbons or ketones. The microtiter plate assay was evaluated using wild-type and recombinant strains of Shewanella oneidensis and Escherichia coli expressing the enzyme OleA, previously shown to initiate hydrocarbon biosynthesis. The strains expressing exogenous Stenotrophomonas maltophilia oleA, with increased levels of ketone production as determined by gas chromatography-mass spectrometry, were distinguished with Nile red fluorescence. Confocal microscopy images of S. oneidensis oleA-expressing strains stained with Nile red were consistent with a membrane localization of the ketones. This differed from Nile red staining of bacterial PHB or algal lipid droplets that showed intracellular inclusion bodies. These results demonstrated the applicability of Nile red in a high-throughput technique for the detection of bacterial hydrocarbons and ketones.

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

2011-01-01

208

Bacterial contamination of water in dental unit reservoirs.  

PubMed

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 (bioMérieux, 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

Szyma?ska, Jolanta

2007-01-01

209

Clinical impact of the over-expression of efflux pump in nonfermentative Gram-negative bacilli, development of efflux pump inhibitors.  

PubMed

In this manuscript, we want to review the biochemical and genetic characteristics of the different efflux pumps involved in both intrinsic and acquired multiresistance in non-fermentative Gram-negative bacteria such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia, as well as the regulation of their expression. Moreover, the clinical impact of the over-expression of these efflux pumps and the investigation developed to define efflux pump inhibitors will be discussed. In this review it will be stated that antimicrobial resistance associated with the over-expression of MDR efflux pumps is widely recognised as a frequent multidrug resistant determinant in nonfermentative Gram-negative bacilli. Moreover, MDR pumps contribute to the intrinsic resistance of these bacterial pathogens. Circumventing the activity of efflux pumps will thus have clear benefits for therapy, since this will increase the susceptibility of nonfermentative Gram-negative bacilli, thereby increasing the therapeutic efficacy of antibiotics used for treating such infections by those pathogens. In addition, it has been shown that the lack of activity of MDR pumps impedes selection of mutants showing high-level antibiotic resistance to antibiotics like quinolones or beta-lactams. Thus, besides reducing intrinsic resistance, inhibitors of efflux pumps will reduce the emergence of mutants that acquire antibiotic resistance as the consequence of mutations in MDR-regulatory elements or in other targets. Recent advances on the search for inhibitors of MDR pumps will also be finally discussed. PMID:18781925

Vila, Jordi; Martínez, José Luis

2008-09-01

210

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

PubMed

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

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

2001-08-01

211

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

PubMed Central

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.

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

2012-01-01

212

Evaluation of the ID 32E for the identification of Gram-negative glucose-fermenting and glucose-non-fermenting bacilli.  

PubMed

OBJECTIVE: To evaluate the ID 32E bacterial identification system for accuracy in the identification of members of the family Enterobacteriaceae, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter baumannii/Iwoffii. METHODS: Stock cultures of 497 Enterobacteriaceae and 27 commonly encountered non-enteric Gram-negative rods were tested in the ID 32E system. For each isolate, the resulting 11-digit profile number was converted to an identification using the APILAB Plus software (version 3.2.2). This identification was then compared to the reference identification obtained using conventional biochemicals. RESULTS: Of the 524 isolates tested, 405 (77.3%) were identified correctly; 52 (9.9%) were identified incorrectly. Sixty-seven (12.8%) identifications were either doubtful or unacceptable, and were not limited to any particular genus or species, with the exception of Ewingella americana and Serratia plymuthica, which did not grow well enough in the strip at 35 degrees C to be correctly identified. All five isolates of Acinetobacter Iwoffii were misidentified as Alcaligenes spp. CONCLUSIONS: With this challenge set of organisms, the ID 32E correctly identified 77.3% of the isolates tested. For commonly encountered isolates, the accuracy approached 90%. We conclude that the ID 32E offers an alternative for the identification of common clinical isolates. PMID:11856267

O'Hara, Caroline Mohr; Miller, J. Michael

1999-05-01

213

Prevalence of antibiotic-resistant bacteria in herbal products.  

PubMed

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

Brown, Joseph C; Jiang, Xiuping

2008-07-01

214

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

PubMed

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

Horká, Marie; R?zicka, Filip; Horký, Jaroslav; Holá, Veronika; Slais, Karel

2006-09-01

215

Isolation and characterization of phenol utilizing bacteria from industrial effluent-contaminated soil and kinetic evaluation of their biodegradation potential.  

PubMed

Microbial degradation of phenol by pure bacterial species is a well-known approach towards alleviation of environmental pollution. In this study, five phenol-degrading bacterial species designated as CUPS-1 to CUPS-5 were isolated from the oil-effluent dumped sites of Haldia Industrial area of West Bengal, India. Detailed morphological, biochemical and molecular characterization identified CUPS-3 as a novel strain- Stenotrophomonas maltophilia (GU358076), while the others could be identified as Pseudomonas (CUPS-2, 5), Delftia (CUPS-1) and Micrococcus (CUPS-4) genera, respectively. Although all of these strains utilized phenol as their sole carbon source supporting growth, three among them, CUPS-2, CUPS-3 and CUPS-5 proved potential phenol degraders and hence used for further biodegradation studies. Degradation experiments were carried out for several initial phenol concentrations of 500 mg/L, 750 mg/L, 1000 mg/L, 1250 mg/L and 1500 mg/L. The novel strain, CUPS-3 could completely degrade 500 mg/L phenol within 48 h, with 0.0937/h substrate degradation rate and 16.34 mg/L/h substrate consumption rate. The strains degraded phenol via meta-cleavage pathway. Prediction of kinetic parameters of the biodegradation was accomplished Haldane model using the experimental data of degradation rate and phenol concentration as function of time. PMID:24117085

Pal Basak, Sreela; Sarkar, Priyabrata; Pal, Priyabrata

2014-01-01

216

[Bacteremia with granulocytopenia--microbiology and empiric antibiotic treatment].  

PubMed

This article sums up a retrospective analysis of 84 episodes of bacteraemia in acute leukaemia patients with severe neutropenia in a Norwegian teaching hospital during the period 1990-95. Gram negative bacteria represented 54% of the blood culture isolates, all of which were susceptible to aminoglycosides, and nearly all to ceftazidime and imipenem. Penicillin/aminoglycoside was used as initial therapy in 43% of the episodes. Initial empiric therapy was modified in 52% of the events. Only 15% of patients receiving the penicillin/aminoglycoside combination actually had infections with organisms susceptible to penicillin. Only 2% of patients with gram negative infections received initial synergistic treatment with two effective drugs. Mortality from infections was 8% in acute leukaemia patients with documented bacteraemia. Deaths mainly occurred in patients with terminal leukaemia disease. Late breakthrough bacteraemias with Stenotrophomonas maltophilia and Pseudomonas aeruginosa caused 50% of all fatal infections. The analysis suggests that no patients died during initial bacteraemia with penicillin-resistant organisms treated with penicillin/aminoglycoside. The antibiotic susceptibility of the isolated bacteria was favourable compared to what has been found in other countries. For the time being, we believe that the ecological advantages of using penicillin/aminoglycoside as initial empiric treatment of febrile neutropenia are greater than the disadvantages. PMID:9889610

Hammerstrřm, J; Jacobsen, T

1998-11-20

217

Efficacy of an anaerobic swab transport system to maintain aerobic and anaerobic microorganism viability after storage at -80 degrees C.  

PubMed

An Amies agar gel swab transport system was evaluated for its ability to maintain bacterial viability and relative quantity after freezing at -80°C. Nine American Type Culture Collection (ATCC) bacterial strains were used: 3 anaerobic strains (Propionibacterium acnes, Peptostreptococcus anaerobius, and Clostridium sporogenes) and 6 facultative or strict aerobic bacterial strains (Stenotrophomonas maltophilia, Escherichia coli ([ATCC 25922 and ATCC 11775], Salmonella enterica subsp. enterica serovar Typhimurium, Staphylococcus saprophyticus, and Lactobacillus casei). The bacterial species were chosen because they corresponded to bacteria identified in psittacine feces and cloacal samples. There were no significant differences between growth scores at baseline and after storage at -80°C for 40 days for any of the bacteria examined after 48 and 72 hr of incubation, with the exception of P. anaerobius. For P. anaerobius, there was a significant reduction (P < 0.001) in the growth score after storage at -80°C for 40 days from that of the baseline; however, the bacteria were still viable. The tested swab transport system may be useful when lengthy storage and transport times necessitate freezing samples prior to culture. PMID:21217035

Musser, Jeffrey M B; Gonzalez, Rosa

2011-01-01

218

Changing trends in etiology of bacteremia in patients with cancer.  

PubMed

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

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

2006-08-01

219

Development of rRNA-based PCR assays for identification of Burkholderia cepacia complex isolates recovered from cystic fibrosis patients.  

PubMed

PCR assays targeting rRNA genes were developed to identify species (genomovars) within the Burkholderia cepacia complex. Each assay was tested with 177 bacterial isolates that also underwent taxonomic analysis by whole-cell protein profile. These isolates were from clinical and environmental sources and included 107 B. cepacia complex strains, 23 Burkholderia gladioli strains, 20 Ralstonia pickettii strains, 10 Pseudomonas aeruginosa strains, 8 Stenotrophomonas maltophilia strains, and 9 isolates belonging to nine other species. The sensitivity and specificity of the 16S rRNA-based assay for Burkholderia multivorans (genomovar II) were 100 and 99%, respectively; for Burkholderia vietnamiensis (genomovar V), sensitivity and specificity were 87 and 92%, respectively. An assay based on 16S and 23S rRNA gene analysis of B. cepacia ATCC 25416 (genomovar I) was useful in identifying genomovars I, III, and IV as a group (sensitivity, 100%, and specificity, 99%). Another assay, designed to be specific at the genus level, identified all but one of the Burkholderia and Ralstonia isolates tested (sensitivity, 99%, and specificity, 96%). The combined use of these assays offers a significant improvement over previously published PCR assays for B. cepacia. PMID:10488171

LiPuma, J J; Dulaney, B J; McMenamin, J D; Whitby, P W; Stull, T L; Coenye, T; Vandamme, P

1999-10-01

220

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

PubMed

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

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

2001-12-01

221

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

PubMed Central

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

2009-01-01

222

Specific and Rapid Detection by Fluorescent In Situ Hybridization of Bacteria in Clinical Samples Obtained from Cystic Fibrosis Patients  

PubMed Central

We report on the rapid and specific detection of bacteria commonly isolated from clinical specimens from cystic fibrosis (CF) patients by fluorescent in situ hybridization (FISH). On the basis of comparative sequence analysis, we designed oligonucleotide probes complementary to species-specific 16S rRNA regions of these microorganisms and demonstrated the specificities of the probes by hybridization of different remotely related as well as closely related reference strains. Furthermore, in a pilot project we investigated 75 sputum samples and 10 throat swab specimens from CF patients by FISH and detected Pseudomonas aeruginosa, Burkholderia cepacia, Stenotrophomonas maltophilia, Haemophilus influenzae, and Staphylococcus aureus within these specimens. The specificity of FISH was 100% in comparison to the results of conventional microbial culture. In contrast, the sensitivity of standard laboratory cultivation was moderately higher, since the limit for microscopic detection of bacteria within sputum samples by FISH was approximately 4 × 105 CFU/ml of sputum (resulting in a 90% sensitivity for FISH). Moreover, we demonstrated that FISH will be useful for the rapid detection of bacteria that cause acute pulmonary exacerbations in CF patients, as demonstrated in patients with H. influenzae, S. aureus, and P. aeruginosa exacerbations. Therefore, FISH is a valuable additional method for the rapid and specific detection of bacteria in clinical samples from CF patients, in particular, patients with pulmonary exacerbations.

Hogardt, Michael; Trebesius, Karlheinz; Geiger, Anna M.; Hornef, Mathias; Rosenecker, Josef; Heesemann, Jurgen

2000-01-01

223

Distribution of alginate genes in bacterial isolates from corroded metal surfaces.  

PubMed

The distribution of alginate genes encoding biosynthesis of alginate was examined for bacterial isolates associated with corrosive biofilms recovered from source water, cooling lines, and reactor surfaces of a nuclear power plant. A total of 120 diverse Gram-positive and -negative isolates were obtained. Using DNA:DNA hybridization, 11 isolates were shown to contain sequences homologous to structural (algD, algG, alg-76) and/or regulatory (albB) alginate biosynthetic genes derived from an alginate-producing cystic fibrosis isolate of Pseudomonas aeruginosa (FRD1). Identification of isolates was accomplished by fatty acids methyl esters (FAME) analysis and the Biolog identification system. Nine of the twelve isolates were identified as various Pseudomonas spp., and two additional Gram-negative isolates were tentatively identified as Aeromonas veronii and Stenotrophomonas maltophilia. The remaining isolate was identified as a Gram-positive Bacillus pumilus. The results of the investigation extend current knowledge on the distribution of alginate biosynthetic genes in environmental isolates and permits the development of a more environmentally realistic model system to investigate the role of exopolymer production in biofilm formation and biocorrosion processes. PMID:24190336

Wallace, W H; Rice, J F; White, D C; Sayler, G S

1994-05-01

224

Malakoplakia of liver: Report of two cases.  

PubMed

Malakoplakia is an unusual chronic inflammatory condition characterized by the presence of Michaelis-Gutmann bodies. Patients with malakoplakia often have an immunodeficiency state. It is believed that malakoplakia results from a defective macrophage response to phagocytosed bacteria. Malakoplakia most commonly affects the genitourinary tract. Cases confined to the liver are rare, with only five cases described in the literature. We report two cases of malakoplakia of liver; both were incidental autopsy findings. The first case involves a 53-year-old man with systemic lupus erythematosus and chronic refractory pancytopenia who presented with febrile neutropenia. His blood culture was positive for Stenotrophomonas maltophilia and Enterococcus faecium, and he subsequently developed invasive pulmonary aspergillosis. The second case involves a 60-year-old man who presented with a mass in periorbital tissue which, on biopsy, showed inflammation and Treponema-like spirochetes. He died unexpectedly at home. Autopsy revealed adrenal gland chronic inflammation and abscess. Both cases had grossly normal livers with microscopic findings of calcified targetoid structures consistent with Michaelis-Gutmann bodies. In these cases, malakoplakia was an incidental finding confined to liver. Although asymptomatic in these cases, diagnosis in the liver may be useful to initiate a search for hepatic or non-hepatic infections. PMID:24755510

Botros, Noha; Yan, Sen R; Wanless, Ian R

2014-07-01

225

Contemporary unconventional clinical use of co-trimoxazole.  

PubMed

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

Goldberg, E; Bishara, J

2012-01-01

226

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

PubMed

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 ?-lactamase showed the presence of CTX-M-15 ?-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

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

2012-01-01

227

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

PubMed

A gene in Bradyrhizobium japonicum USDA 110, annotated as a ribitol dehydrogenase (RDH), had 87 % sequence identity (97 % positives) to the N-terminal 31 amino acids of an L-glucitol dehydrogenase from Stenotrophomonas maltophilia DSMZ 14322. The 729-bp long RDH gene coded for a protein consisting of 242 amino acids with a molecular mass of 26.1 kDa. The heterologously expressed protein not only exhibited the main enantio selective activity with D-glucitol oxidation to D-fructose but also converted L-glucitol to D-sorbose with enzymatic cofactor regeneration and a yield of 90 %. The temperature stability and the apparent K m value for L-glucitol oxidation let the enzyme appear as a promising subject for further improvement by enzyme evolution. We propose to rename the enzyme from the annotated RDH gene (locus tag bll6662) from B. japonicum USDA as a D-sorbitol dehydrogenase (EC 1.1.1.14). PMID:24061413

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

2014-04-01

228

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

PubMed

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

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

2011-09-01

229

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

PubMed

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

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

2012-12-01

230

Genetic Diversity and Phylogeny of Antagonistic Bacteria against Phytophthora nicotianae Isolated from Tobacco Rhizosphere  

PubMed Central

The genetic diversity of antagonistic bacteria from the tobacco rhizosphere was examined by BOXAIR-PCR, 16S-RFLP, 16S rRNA sequence homology and phylogenetic analysis methods. These studies revealed that 4.01% of the 6652 tested had some inhibitory activity against Phytophthora nicotianae. BOXAIR-PCR analysis revealed 35 distinct amplimers aligning at a 91% similarity level, reflecting a high degree of genotypic diversity among the antagonistic bacteria. A total of 25 16S-RFLP patterns were identified representing over 33 species from 17 different genera. Our results also found a significant amount of bacterial diversity among the antagonistic bacteria compared to other published reports. For the first time; Delftia tsuruhatensis, Stenotrophomonas maltophilia, Advenella incenata, Bacillus altitudinis, Kocuria palustris, Bacillus licheniformis, Agrobacterium tumefaciens and Myroides odoratimimus are reported to display antagonistic activity towards Phytophthora nicotianae. Furthermore, the majority (75%) of the isolates assayed for antagonistic activity were Gram-positives compared to only 25% that were Gram-negative bacteria.

Jin, Fengli; Ding, Yanqin; Ding, Wei; Reddy, M.S.; Fernando, W.G. Dilantha; Du, Binghai

2011-01-01

231

Low rates of Pseudomonas aeruginosa misidentification in isolates from cystic fibrosis patients.  

PubMed

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

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

2009-05-01

232

Newer antibacterial agents and their potential role in cystic fibrosis pulmonary exacerbation management.  

PubMed

Pulmonary exacerbations in cystic fibrosis (CF) are frequent events and account for a substantial proportion of the burden of morbidity and mortality in this disease. Antibacterial therapies to treat pulmonary exacerbations are instituted empirically and are individualized based on both patient factors (severity of exacerbation, frequency of exacerbation, recent courses of anti-infectives) and pathogen factors (previously isolated pathogens and in vitro predicted susceptibilities). However, the epidemiology of pathogens infecting CF airways is changing, with increased incidence of methicillin-resistant Staphylococcus aureus (MRSA), drug-resistant Pseudomonas aeruginosa and other Gram-negative non-fermenters such as Stenotrophomonas maltophilia and Achromobacter xylosoxidans. Accordingly, a great need for new and novel agents for the management of acute exacerbations in CF exists. While several antibiotics have recently been approved or are close to approval for clinical use, frequently their emphasis has been for Gram-positive, and specifically MRSA-related, disease. Despite this, these agents may have a role in CF-related exacerbations. This article reviews the spectrum of activity, pharmacokinetics and clinical and theoretical evidence for the use of newer agents including tigecycline, doripenem and ceftobiprole in the management of CF pulmonary exacerbations. Appropriate use of these agents in CF will require detailed CF-specific pharmacokinetic and pharmacodynamic data. PMID:20605846

Parkins, M D; Elborn, J S

2010-09-01

233

[Use of 16S rRNA gene sequencing for identification of "Pseudomonas-like" isolates from sputum of patients with cystic fibrosis].  

PubMed

Since nonfermenting, Gram negative bacilli recovered from patients with cystic fibrosis could be misidentified with phenotypic procedures, we used partial 16S ribosomal RNA gene (16S gene) sequencing to identify these "Pseudomonas-like" isolates. 473 isolates were recovered from 66 patients in 2003. Sequencing was used to identify 29 (from 24 patients) of the 473 isolates, showing unclear results with routine tests. PCR with specific primers was carried out to amplify a 995 bp fragment, which was then sequenced. The sequences were analyzed with GenBank database for species assignment. Phenotypic and genotypic results were concordant for 20/29 isolates (10 Pseudomonas aeruginosa, 5 Burkholderia cepacia, 3 Stenotrophomonas maltophilia, 2 Achromobacter xylosoxidans). However, 3 of the 5 B. cepacia isolates were then identified as Burkholderia multivorans with a PCR-RFLP procedure. Phenotypic misidentification was observed for 9/29 isolates: 4 A. xylosoxidans, 1 P. aeruginosa, 1 Bordetella petrii, 1 Bordetella bronchiseptica, 1 Ralstonia respiraculi and 1 Ralstonia mannitolilytica. Partial 16S gene sequencing improved the identification of "Pseudomonas-like" isolates from cystic fibrosis patients, but the accuracy to distinguish between genomovars of the B. cepacia complex was inadequate. PMID:16081224

Moissenet, D; Bingen, E; Arlet, G; Vu-Thien, H

2005-01-01

234

Rapid screening and cultivation of oleaginous microorganisms.  

PubMed

Oleaginous microbial strains were cultivated to identify the best oil-producing strain amongst Yarrowia lipolytica (CGMCC 2.1398), Lipomyces starkeyi (CGMCC 2.1608), Rhodosporidium toruloides (CGMCC 2.1389), Mortierella isabellina (CGMCC 3.3410), Cunninghamella blakeleana (CGMCC 3.970), and Mycobacterium QJ311. A method for rapid determination of oil content and fatty acid composition was established to identify the optimum oil-producing strains. This method had a relative standard deviation of 4.09%, an average recovery ratio of 97.09% and a detection limit of 0.1-1.0 g. Mortierella isabellina CGMCC 3.3410 was identified as the best oil-producing strain amongst the six strains tested, with a total biomass of 75 g/10 L and a lipid content of 35%. A rapid screening method of oleaginous microorganisms is discussed for the first time. PMID:22611917

Gao, Xinlei; Liu, Ye; Che, Zhongju; Wu, Li

2012-04-01

235

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

PubMed

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

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

2013-01-01

236

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

PubMed

Many bacterial typing methods are specific for one species only, time-consuming, or poorly reproducible. DiversiLab (DL; bioMérieux) potentially overcomes these limitations. In this study, we evaluated the DL system for the identification of hospital outbreaks of a number bacterial species. Appropriately typed clinical isolates were tested with DL. DL typing agreed with pulsed-field gel electrophoresis (PFGE) for Acinetobacter (n = 26) and Stenotrophomonas maltophilia (n = 13) isolates. With two exceptions, DL typing of Klebsiella isolates (n = 23) also correlated with PFGE, and in addition, PFGE-nontypeable (PFGE-NT) isolates could be typed. Enterobacter (n = 28) results also correlated with PFGE results; also, PFGE-NT isolates could be clustered. In a larger study (n = 270), a cluster of 30 isolates was observed that could be subdivided by PFGE. The results for Escherichia coli (n = 38) correlated less well with an experimental multilocus variable number of tandem repeats analysis (MLVA) scheme. Pseudomonas aeruginosa (n = 52) showed only a limited number of amplification products for most isolates. When multiple Pseudomonas isolates were assigned to a single type in DL, all except one showed multiple multilocus sequence types. Methicillin-resistant Staphylococcus aureus generally also showed a limited number of amplification products. Isolates that belonged to different outbreaks by other typing methods, including PFGE, spa typing, and MLVA, were grouped together in a number of cases. For Enterococcus faecium, the limited variability of the amplification products obtained made interpretation difficult and correlation with MLVA and esp gene typing was poor. All of the results are reflected in Simpson's index of diversity and adjusted Rand's and Wallace's coefficients. DL is a useful tool to help identify hospital outbreaks of Acinetobacter spp., S. maltophilia, the Enterobacter cloacae complex, Klebsiella spp., and, to a somewhat lesser extent, E. coli. In our study, DL was inadequate for P. aeruginosa, E. faecium, and MRSA. However, it should be noted that for the identification of outbreaks, epidemiological data should be combined with typing results. PMID:20861340

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

2010-11-01

237

The antibacterial properties of Malaysian tualang honey against wound and enteric microorganisms in comparison to manuka honey  

PubMed Central

Background Antibiotic resistance of bacteria is on the rise, thus the discovery of alternative therapeutic agents is urgently needed. Honey possesses therapeutic potential, including wound healing properties and antimicrobial activity. Although the antimicrobial activity of honey has been effectively established against an extensive spectrum of microorganisms, it differs depending on the type of honey. To date, no extensive studies of the antibacterial properties of tualang (Koompassia excelsa) honey on wound and enteric microorganisms have been conducted. The objectives of this study were to conduct such studies and to compare the antibacterial activity of tualang honey with that of manuka honey. Methods Using a broth dilution method, the antibacterial activity of tualang honey against 13 wound and enteric microorganisms was determined; manuka honey was used as the control. Different concentrations of honey [6.25-25% (w/v)] were tested against each type of microorganism. Briefly, two-fold dilutions of honey solutions were tested to determine the minimum inhibitory concentration (MIC) against each type of microorganism, followed by more assays within a narrower dilution range to obtain more precise MIC values. MICs were determined by both visual inspection and spectrophotometric assay at 620 nm. Minimum bactericidal concentration (MBC) also was determined by culturing on blood agar plates. Results By visual inspection, the MICs of tualang honey ranged from 8.75% to 25% compared to manuka honey (8.75-20%). Spectrophotometric readings of at least 95% inhibition yielded MIC values ranging between 10% and 25% for both types of honey. The lowest MBC for tualang honey was 20%, whereas that for manuka honey was 11.25% for the microorganisms tested. The lowest MIC value (8.75%) for both types of honey was against Stenotrophomonas maltophilia. Tualang honey had a lower MIC (11.25%) against Acinetobacter baumannii compared to manuka honey (12.5%). Conclusion Tualang honey exhibited variable activities against different microorganisms, but they were within the same range as those for manuka honey. This result suggests that tualang honey could potentially be used as an alternative therapeutic agent against certain microorganisms, particularly A. baumannii and S. maltophilia.

Tan, Hern Tze; Rahman, Rosliza Abdul; Gan, Siew Hua; Halim, Ahmad Sukari; Hassan, Siti Asma'; Sulaiman, Siti Amrah; BS, Kirnpal-Kaur

2009-01-01

238

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

Microsoft Academic Search

A new technology of transforming ferulic acid, which was from waste residue of rice bran oil, into vanillin was developed by a combination of fungal strains Aspergillus niger CGMCC0774 and Pycnoporus cinnabarinus CGMCC1115. Various concentrations of ferulic acid were compared, and the highest yield reached 2.2gl?1 of vanillic acid by A. niger CGMCC0774 in a 25l fermenter when concentration of

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

2007-01-01

239

Weeds as a source of plant growth promoting rhizobacteria in agricultural soils.  

PubMed

The influence of plant growth promoting (PGP) activity of bacterial communities recovered from each of six weed species (barnyard grass (Echinochloa crusfalli (L.) Beauv.), corn spurrey (Spergula arvensis L.), goldenrod (Sonchus sp.), Italian ryegrass (Lolium multiflorum L.), lamb's-quarters (Chenopodium album L.), and quack grass (Agropyron repens (L.) Beauv.)) was examined in relation to the effect it had on the growth of the potato cultivar Russet Burbank. Bacterial species composition and community structure were compared, species-abundance relationships were determined, and those members conferring positive benefits for potato growth and development were identified. Of the genera identified, Bacillus, Arthrobacter, Stenotrophomonas, Acinetobacter, and Pseudomonas were the most common, and Stenotrophomonas maltophilia was the most frequent species recovered across all sources. Significantly higher population densities were found in the root zones of quack grass, compared with Italian ryegrass and lamb's-quarters. There were no significant differences in species richness among the root zones; however, evenness indices (species distribution) were significantly lower in corn spurrey (P = 0.05). Significantly higher diversity indices (Hill-1 and Hill-2 numbers) (P = 0.05) were found in the root zone soil communities of potato and goldenrod, indicating a decrease in the proportional abundance of common and very abundant species, respectively, while in barnyard grass, corn spurrey, and Italian ryegrass the reverse was the case. In both years of the study, Italian ryegrass and corn spurrey were consistently better sources of PGP rhizobacteria for potatoes, significantly (P < 0.001) increasing the mean wet weight of shoots and roots in in vitro bacterization studies. Barnyard grass was a consistently poor source of such isolates. Species-abundance measures of root zone bacterial biodiversity were not found, in this instance, to be a particularly good predictor of the presence or absence of PGP rhizobacteria. We consider that the study of complementary crops and soil-conditioning treatments should not preclude the examination of weed species as possible beneficials, as alterations in rhizobacterial biodiversity and functional versatility can influence the numbers and types of PGP bacterial strains, and consequently may serve to improve soil quality. PMID:11766050

Sturz, A V; Matheson, B G; Arsenault, W; Kimpinski, J; Christie, B R

2001-11-01

240

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

Federal Register 2010, 2011, 2012, 2013

...maltophilia, Methylobacterium extorquens, and unidentified gram negative rods. This emergency exemption involves the use of...maltophilia, Methylobacterium extorquens, and unidentified gram negative rods. Information in accordance with 40 CFR part...

2012-08-17

241

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

PubMed

Ten PGPR from different backgrounds were assayed on Papaver somniferum var. Madrigal to evaluate their potential as biotic elicitors to increase alkaloid content under the rationale that some microbe associated molecular patterns (MAMPs) are able to trigger plant metabolism. First, the 10 strains and their culture media at two different concentrations were tested for their ability to trigger seed germination. Then, the best three strains were tested for their ability to increase seedling growth and alkaloid levels under greenhouse conditions. Only three strains and their culture media enhanced germination. Then, germination enhancing capacity of these best three strains, N5.18 Stenotrophomonas maltophilia, Aur9 Chryseobacterium balustinum and N21.4 Pseudomonas fluorescens was evaluated in soil. Finally, the three strains were applied on seedlings at two time points, by soil drench or by foliar spray. Photosynthesis was measured, plant height was recorded, capsules were weighted and alkaloids analyzed by HPLC. Only N5.18 delivered by foliar spray significantly increased plant height coupled to an increase in total alkaloids and a significant increase in opium poppy straw dry weight; these increases were supported by a better photosynthetic efficiency. The relative contents of morphine, thebaine, codeine and oripavine were affected by this treatment causing a significant increase in morphine coupled to a decrease in thebaine, demonstrating the effectivity of MAMPs from N5.18 in this plant species. Considering the increase in capsule biomass and alkaloids together with the acceleration of germination, strain N5.18 appears as a good candidate to elicit plant metabolism and consequently, to increase productivity of Papaver somniferum. PMID:24296249

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

2014-01-01

242

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

PubMed

The survival of eight undesired (spoilage/pathogenic) food related bacteria (Citrobacter freundii PSS60, Enterobacter spp. PSS11, Escherichia coli PSS2, Klebsiella oxytoca PSS82, Serratia grimesii PSS72, Pseudomonas putida PSS21, Stenotrophomonas maltophilia PSS52 and Listeria monocytogenes ATCC 19114(T)) was investigated in mineral nutrient solution (MNS) during the crop cycle of radishes (Raphanus sativus L.) cultivated in hydroponics in a greenhouse. MNSs were microbiologically analyzed weekly by plate count. The evolution of the pure cultures was also evaluated in sterile MNS in test tubes. The inoculated trials contained an initial total mesophilic count (TMC) ranging between 6.69 and 7.78Log CFU/mL, while non-sterile and sterile control trials showed levels of 4.39 and 0.97Log CFU/mL, respectively. In general, all inoculated trials showed similar levels of TMC in MNS during the experimentation, even though the levels of the inoculated bacteria decreased. The presence of the inoculums was ascertained by randomly amplified polymorphic DNA (RAPD) analysis applied on the isolates collected at 7-day intervals. At harvest, MNSs were also analyzed by denaturing gradient gel electrophoresis (DGGE). The last analysis, except P. putida PSS21 in the corresponding trial, did not detect the other bacteria, but confirmed that pseudomonads were present in un-inoculated MNSs. Despite the high counts detected (6.44 and 7.24CFU/g), only C. freundii PSS60, Enterobacter spp. PSS11 and K. oxytoca PSS82 were detected in radishes in a living form, suggesting their internalization. PMID:23290244

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

2013-01-01

243

Carbapenem Derivatives as Potential Inhibitors of Various ?-Lactamases, Including Class B Metallo-?-Lactamases  

PubMed Central

A variety of 1?-methylcarbapenem derivatives were screened to identify inhibitors of IMP-1 metallo-?-lactamase, a class B ?-lactamase, in an automated microassay system using nitrocefin as a substrate. The structure–inhibitory-activity relationship study revealed that three types of 1?-methylcarbapenems having benzothienylthio, dithiocarbamate, or pyrrolidinylthio moieties at the C-2 position showed good inhibitory activity. Among the compounds screened, J-110,441, having a benzothienylthio moiety at the C-2 position of 1?-methylcarbapenem, was the most potent inhibitor of class B metallo-?-lactamases with Ki values of 0.0037, 0.23, 1.00, and 0.83 ?M for IMP-1 encoded by the blaIMP gene, CcrA from Bacteroides fragilis, L1 from Stenotrophomonas maltophilia, and type II from Bacillus cereus, respectively. In a further characterization study, J-110,441 also showed inhibitory activity against TEM-type class A serine ?-lactamase and chromosomal class C serine ?-lactamase from Enterobacter cloacae with Ki values of 2.54 and 0.037 ?M, respectively. Combining imipenem or ceftazidime with J-110,441 had a synergistic effect on the antimicrobial activity against ?-lactamase-producing bacteria. Against the isolates of IMP-1-producing Serratia marcescens, the MICs of imipenem decreased to levels ranging from 1/64 to 1/4 in the presence of one-fourth of the MIC of J-110,441. Against E. cloacae producing high levels of class C ?-lactamase, the MIC of ceftazidime decreased from 64 to 4 ?g/ml in the presence of 4 ?g of J-110,441 per ml. This is the first report to describe a new class of inhibitor of class B and class C ?-lactamases including transferable IMP-1 metallo-?-lactamases.

Nagano, Rie; Adachi, Yuka; Imamura, Hideaki; Yamada, Koji; Hashizume, Terutaka; Morishima, Hajime

1999-01-01

244

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

PubMed

Gram-negative nonfermentative bacilli (NFB) are widely spread in the environment. Besides of difficulties for identification, they often have a marked multiresistance to antimicrobial agents, including those active against Pseudomonas aeruginosa. The objective of this study was to evaluate the 'in vitro' activity of different antimicrobial agents on 177 gram-negative nonfermentative bacilli isolates (excluding Pseudomonas aeruginosa and Acinetobacter spp.) isolated from clinical specimens. Minimum inhibitory concentrations (MIC) were determined according to the Mueller Hinton agar dilution method against the following antibacterial agents: ampicillin, piperacillin, piperacillin-tazobactam, sulbactam, cefoperazone, cefoperazone-sulbactam, ceftazidime, cefepime, aztreonam, imipenem, meropenem, colistin, gentamicin, amikacin, trimethoprim-sulfamethoxazole, chloramphenicol, erythromycin, rifampin, norfloxacin, ciprofloxacin and minocycline. Seven isolates: Sphingobacterium multivorum (2), Sphingobacteriumspiritivorum (1), Empedobacterbrevis (1), Weeksella virosa (1), Bergeyella zoohelcum (1) and Oligella urethralis (1), were tested for amoxicillin-clavulanic acid and ampicillin-sulbactam susceptibility, and susceptibility to cefoperazone or sulbactam was not determined. Multiresistance was generally found in Stenotrophomonas maltophilia, Burkholderia cepacia, Chryseobacterium spp., Myroides spp., Achromobacter xylosoxidans, and Ochrobactrum anthropi isolates. On the other hand, Pseudomonas stutzeri, Shewanella putrefaciens-algae, Sphingomonas paucimobilis, and Pseudomonas oryzihabitans, Bergeyella zoohelcum, Weeksella virosa and Oligella urethralis were widely susceptible to the antibacterial agents tested. As a result of the wide variation in antimicrobial susceptibility shown by different species, a test on susceptibility to different antibacterial agents is essential in order to select an adequate therapy. The marked multiresistance evidenced by some species, prompts the need to develop new antimicrobial agents active against this group of bacteria and to search for synergistic combinations. PMID:15991478

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

2005-01-01

245

Comparison of two culture methods for detection of tobramycin-resistant gram-negative organisms in the sputum of patients with cystic fibrosis.  

PubMed

A culture method utilizing quantitative plating on antibiotic-containing media has been proposed as a technique for the detection of tobramycin-resistant organisms that is more sensitive than standard methods. Typical sputum culture methods quantitate the relative amounts of each distinct morphotype, followed by antibiotic susceptibility testing of a single colony of each morphotype. Sputum specimens from 240 cystic fibrosis patients were homogenized, serially diluted, and processed in parallel by the standard method (MacConkey agar and OF basal medium with agar, polymyxin, bacitracin, and lactose) and by plating on antibiotic-containing media (MacConkey agar with tobramycin added at 25 microg/ml [MAC-25] and 100 microg/ml [MAC-100]). MICs of tobramycin were determined for all Pseudomonas aeruginosa isolates by broth microdilution. Growth of P. aeruginosa on MAC-25 was considered to be equivalent to a tobramycin MIC of > or = 16 microg/ml, and growth on MAC-100 was considered to be equivalent to a tobramycin MIC of > or = 128 microg/ml. Analysis of method-specific detection rates showed that tobramycin-containing medium was more sensitive than the standard method for the detection of tobramycin-resistant P. aeruginosa, Stenotrophomonas maltophilia, and Achromobacter xylosoxidans but was less sensitive for the detection of Burkholderia cepacia than the standard method. When MICs for P. aeruginosa that grew on tobramycin-containing medium were tested by broth microdilution, the MICs for 28 of 121 strains (23%) growing on MAC-25 and 22 of 56 strains (39%) growing on MAC-100 were MICs < 16 and < 128 microg/ml, respectively. Addition of a tobramycin-containing MacConkey plate to the routine media for sputum culture may provide additional, clinically relevant microbiologic data. PMID:11773088

Van Dalfsen, Jill M; Stapp, Jenny R; Phelps, Charles; Stewart, Patricia; Burns, Jane L

2002-01-01

246

Nosocomial and ventilator-associated pneumonia in a community hospital intensive care unit: a retrospective review and analysis  

PubMed Central

Background Nosocomial and ventilator-associated pneumonia (VAP) are causes of significant morbidity and mortality in hospitalized patients. We analyzed a) the incidence and the outcome of pneumonias caused by different pathogens in the intensive care unit (ICU) of a medium-sized twenty-four bed community hospital and b) the incidence of complications of such pneumonias requiring surgical intervention such as thoracotomy and decortication. Results We retrospectively reviewed the charts of patients diagnosed with nosocomial and ventilator-associated pneumonia in our ICU. Their bronchoalveolar lavage (BAL) and sputum cultures, antibiograms, and other clinical characteristics, including complications and need for tracheostomy, thoracotomy and decortication were studied. In a span of one year (2011–12), 43 patients were diagnosed with nosocomial pneumonia in our ICU. The median simplified acute physiology score (SAPS II) was 39. One or more gram negative organisms as the causative agents were present in 85% of microbiologic samples. The three most prevalent gram negatives were Stenotrophomonas maltophilia (34%), Pseudomonas aeurginosa (40%), and Acinetobacter baumannii (32%). Twenty eight percent of bronchoalveolar samples contained Staphylococcus aureus. Eight three percent of patients required mechanical ventilation postoperatively and 37% underwent tracheostony. Thirty five percent underwent thoracotomy and decortication because of further complications such as empyema and non-resolving parapneumonic effusions. A. baumannii, Klebsiella pneumonia extended spectrum beta lactam (ESBL) and P. aeurginosa had the highest prevalence of multi drug resistance (MDR). Fifteen patients required surgical intervention. Mortality from pneumonia was 37% and from surgery was 2%. Conclusion Nosocomial pneumonias, in particular the ones that were caused by gram negative drug resistant organisms and their ensuing complications which required thoracotomy and decortication, were the cause of significant morbidity in our intensive care unit. Preventative and more intensive and novel infection control interventions in reducing the incidence of nosocomial pneumonias are strongly emphasized.

2014-01-01

247

In vitro activity of the tricyclic beta-lactam GV104326.  

PubMed

GV104326 is a novel tricyclic beta-lactam (a trinem or, formerly, tribactam). The in vitro activity of GV104326 was compared with those of cefuroxime, cefixime, amoxicillin, amoxicillin-clavulanic acid, cefpirome, and ciprofloxacin. GV104326 had in vitro activity generally similar to that of cefixime against members of the family Enterobacteriaceae (MIC at which 90% of the isolates are inhibited [MIC90], < or = 2 micrograms/ml), with cefuroxime and amoxicillin-clavulanic acid being 8- to 32-fold less active and with cefpirome being 4- to 8-fold more active against members of this family. The trinem had no activity against Pseudomonas aeruginosa or Stenotrophomonas maltophilia (MIC90, > 128 micrograms/ml) but was the most active agent against Acinetobacter calcoaceticus. GV104326 was particularly active against gram-positive cocci. Ninety percent of methicillin-susceptible Staphylococcus aureus strains were susceptible to 0.03 microgram of GV104326 per ml, making it the most active agent studied. Enterococci and Lancefield group A and B streptococci were generally equally or somewhat more susceptible to GV104326 than they were to amoxicillin. Streptococcus pneumoniae strains were highly susceptible to GV104326, and those strains which showed decreased susceptibility to penicillin were generally twofold more susceptible to the trinem than to amoxicillin. Haemophilus influenzae and Moraxella catarrhalis were highly susceptible to GV104326 (MIC90s, 0.12 and 0.03 microgram/ml, respectively). The anaerobes Clostridium perfringens, Bacteroides fragilis, and Peptostreptococcus spp. were more susceptible to the trinems (formerly tribactams) than to the other agents studied. PMID:8723475

Wise, R; Andrews, J M; Brenwald, N

1996-05-01

248

Prevalent Bacterial Species and Novel Phylotypes in Advanced Noma Lesions  

PubMed Central

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.

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

249

Fulminant pertussis: a multi-center study with new insights into the clinico-pathological mechanisms.  

PubMed

Pertussis carries a high risk of mortality in very young infants. The mechanism of refractory cardio-respiratory failure is complex and not clearly delineated. We aimed to examine the clinico-pathological features and suggest how they may be related to outcome, by multi-center review of clinical records and post-mortem findings of 10 patients with fulminant pertussis (FP). All cases were less than 8 weeks of age, and required ventilation for worsening respiratory symptoms and inotropic support for severe hemodynamic compromise. All died or underwent extra corporeal membrane oxygenation (ECMO) within 1 week. All had increased leukocyte counts (from 54 to 132 x 10(9)/L) with prominent neutrophilia in 9/10. The post-mortem demonstrated necrotizing bronchitis and bronchiolitis with extensive areas of necrosis of the alveolar epithelium. Hyaline membranes were present in those cases with viral co-infection. Pulmonary blood vessels were filled with leukocytes without well-organized thrombi. Immunodepletion of the thymus, spleen, and lymph nodes was a common feature. Other organisms were isolated as follows; 2/10 cases Para influenza type 3, 2/10 Moraxella catarrhalis, 1/10 each with respiratory syncytial virus (RSV), a coliform organism, methicillin-resistant Staphylococcus aureus (MRSA), Haemophilus influenzae, Stenotrophomonas maltophilia, methicillin-sensitive Staphylococcus aureus (MSSA), and candida tropicalis. We postulate that severe hypoxemia and intractable cardiac failure may be due to the effects of pertussis toxin, necrotizing bronchiolitis, extensive damage to the alveolar epithelium, tenacious airway secretions, and possibly leukostasis with activation of the immunological cascade, all contributing to increased pulmonary vascular resistance. Cellular apoptosis appeared to underlay much of these changes. The secondary immuno-compromise may facilitate co-infection. PMID:19725100

Sawal, Mohammad; Cohen, Marta; Irazuzta, Jose E; Kumar, Ramani; Kirton, Christine; Brundler, Marie-Anne; Evans, Clair Anne; Wilson, John Andrew; Raffeeq, Parakkal; Azaz, Amer; Rotta, Alexandre T; Vora, Ajay; Vohra, Amit; Abboud, Patricia; Mirkin, L David; Cooper, Mehrengise; Dishop, Megan K; Graf, Jeanine M; Petros, Andy; Klonin, Hilary

2009-10-01

250

Antimicrobial susceptibility of Gram-negative organisms isolated from patients hospitalised with pneumonia in US and European hospitals: results from the SENTRY Antimicrobial Surveillance Program, 2009-2012.  

PubMed

Here we evaluated the frequency of occurrence and antimicrobial susceptibility patterns of Gram-negative bacteria isolated from patients hospitalised with pneumonia in medical centres in the USA (n=28) and Europe and the Mediterranean region (EMR) (n=25) in 2009-2012. Susceptibility testing was performed by reference broth microdilution methods. Overall, 12851 isolates were collected (6873/5978 in USA/EMR). The same top 11 organisms were observed in both geographic regions, but in different rank orders, and Gram-negative organisms represented 61.5/76.1% of strains in USA/EMR. Pseudomonas aeruginosa was the most frequently isolated Gram-negative organism in both regions (20.9/20.9% of cases in USA/EMR) and showed reduced susceptibility to most antimicrobials tested, including ceftazidime (79.6/68.7% susceptibility in USA/EMR), meropenem (76.3/65.8%) and piperacillin/tazobactam (72.9/63.9%). Klebsiella spp. was isolated from 9.7/11.6% of cases and showed extended-spectrum ?-lactamase (ESBL) phenotype rates of 19.5/35.1% in USA/EMR. Meropenem and amikacin were active against 62.3/78.7% and 60.8/85.2% of ESBL phenotype Klebsiella spp. from USA/EMR, respectively. Enterobacter spp. ranked fourth in the USA (5.9%) and sixth in EMR (5.5%), whereas Escherichia coli ranked fifth in the USA (5.5%) and third in EMR (11.8%). Acinetobacter spp. and Stenotrophomonas maltophilia combined were isolated from 8.0/10.7% of cases in USA/EMR. A significant increase in P. aeruginosa susceptibility to meropenem and a significant decrease in gentamicin susceptibility among Klebsiella spp. were noted in EMR. These results confirm that very few agents remain broadly active against the most frequently isolated Gram-negative organisms from patients with pneumonia in US and EMR medical centres. PMID:24630306

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

2014-04-01

251

Molecular and Biochemical Heterogeneity of Class B Carbapenem-Hydrolyzing ?-Lactamases in Chryseobacterium meningosepticum  

PubMed Central

Although the carbapenem-hydrolyzing ?-lactamase (CH?L) BlaB-1 is known to be in Chryseobacterium meningosepticum NCTC 10585, a second CH?L gene, blaGOB-1, was cloned from another C. meningosepticum clinical isolate (PINT). The G+C content of blaGOB-1 (36%) indicated the likely chromosomal origin of this gene. Its expression in Escherichia coli DH10B yields a mature CH?L with a pI of 8.7 and a relative molecular mass of 28.2 kDa. In E. coli, GOB-1 conferred resistance to narrow-spectrum cephalosporins and reduced susceptibility to ureidopenicillins, broad-spectrum cephalosporins, and carbapenems. GOB-1 had a broad-spectrum hydrolysis profile including penicillins and cephalosporins (but not aztreonam). The catalytic efficiency for meropenem was higher than for imipenem. GOB-1 had low amino acid identity with the class B CH?Ls, sharing 18% with the closest, L-1 from Stenotrophomonas maltophilia, and only 11% with BlaB-1. Most of the conserved amino acids that may be involved in the active site of CH?Ls (His-101, Asp-103, His-162, and His-225) were identified in GOB-1. Sequence heterogeneity was found for GOB-1-like and BlaB-1-like ?-lactamases, having 90 to 100% and 86 to 100% amino acid identity, respectively, among 10 unrelated C. meningosepticum isolates. Each isolate had a GOB-1-like and a BlaB-1-like gene. The same combination of GOB-1-like and BlaB-1-like ?-lactamases was not found in two different isolates. C. meningosepticum is a bacterial species with two types of unrelated chromosome-borne class B CH?Ls that can be expressed in E. coli and, thus, may represent a clinical threat if spread in gram-negative aerobes.

Bellais, Samuel; Aubert, Daniel; Naas, Thierry; Nordmann, Patrice

2000-01-01

252

The Legionella (Fluoribacter) gormanii Metallo-?-Lactamase: a New Member of the Highly Divergent Lineage of Molecular-Subclass B3 ?-Lactamases  

PubMed Central

A metallo-?-lactamase determinant was cloned from a genomic library of Legionella (Fluoribacter) gormanii ATCC 33297T constructed in the plasmid vector pACYC184 and transformed into Escherichia coli DH5?, by screening for clones showing a reduced susceptibility to imipenem. The product of the cloned determinant, named FEZ-1, contains a 30-kDa polypeptide and exhibits an isoelectric pH of 7.6. Sequencing revealed that FEZ-1 is a molecular-class B ?-lactamase which shares the closest structural similarity (29.7% of identical residues) with the L1 enzyme of Stenotrophomonas maltophilia, being a new member of the highly divergent subclass B3 lineage. All the residues that in L1 are known to be directly or indirectly involved in coordination of the zinc ions were found to be conserved also in FEZ-1, suggesting that the geometry of zinc coordination in the active site of the latter enzyme is identical to that of L1. Unlike L1, however, FEZ-1 appeared to be monomeric in gel permeation chromatography experiments and exhibited a distinctive substrate specificity with a marked preference for cephalosporins and meropenem. The properties of FEZ-1 overall resembled those of a ?-lactamase previously purified from the same strain of L. gormanii (T. Fujii, K. Sato, K. Miyata, M. Inoue, and S. Mitsuhashi, Antimicrob. Agents Chemother. 29:925–926, 1986) and are as yet unique among class B enzymes, reinforcing the notion that considerable functional heterogeneity can be encountered among members of this class. A system for overexpression of the blaFEZ-1 gene in E. coli, based on the T7 phage promoter, was also developed.

Boschi, Letizia; Mercuri, Paola Sandra; Riccio, Maria Letizia; Amicosante, Gianfranco; Galleni, Moreno; Frere, Jean-Marie; Rossolini, Gian Maria

2000-01-01

253

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

PubMed Central

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

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

1997-01-01

254

Chlor-alkali plant contamination of Aussa River sediments induced a large Hg-resistant bacterial community  

NASA Astrophysics Data System (ADS)

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.

Baldi, Franco; Marchetto, Davide; Gallo, Michele; Fani, Renato; Maida, Isabel; Covelli, Stefano; Fajon, Vesna; Zizek, Suzana; Hines, Mark; Horvat, Milena

2012-11-01

255

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

PubMed

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

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

2014-03-12

256

Microbial consortia that degrade 2,4-DNT by interspecies metabolism: isolation and characterisation.  

PubMed

Two consortia, isolated by selective enrichment from a soil sample of a nitroaromatic-contaminated site, degraded 2,4-DNT as their sole nitrogen source without accumulating one or more detectable intermediates. Though originating from the same sample, the optimised consortia had no common members, indicating that selective enrichment resulted in different end points. Consortium 1 and consortium 2 contained four and six bacterial species respectively, but both had two members that were able to collectively degrade 2,4-DNT. Variovorax paradoxus VM685 (consortium 1) and Pseudomonas sp. VM908 (consortium 2) initiate the catabolism of 2,4-DNT by an oxidation step, thereby releasing nitrite and forming 4-methyl-5-nitrocatechol (4M5NC). Both strains contained a gene similar to the dntAa gene encoding 2,4-DNT dioxygenase. They subsequently metabolised 4M5NC to 2-hydroxy-5-methylquinone (2H5MQ) and nitrite, indicative of DntB or 4M5NC monooxygenase activity. A second consortium member, Pseudomonas marginalis VM683 (consortium 1) and P. aeruginosa VM903, Sphingomonas sp. VM904, Stenotrophomonas maltophilia VM905 or P. viridiflava VM907 (consortium 2), was found to be indispensable for efficient growth of the consortia on 2,4-DNT and for efficient metabolisation of the intermediates 4M5NC and 2H5MQ. Knowledge about the interactions in this step of the degradation pathway is rather limited. In addition, both consortia can use 2,4-DNT as sole nitrogen and carbon source. A gene similar to the dntD gene of Burkholderia sp. strain DNT that catalyses ring fission was demonstrated by DNA hybridisation in the second member strains. To our knowledge, this is the first time that consortia are shown to be necessary for 2,4-DNT degradation. PMID:12801097

Snellinx, Zita; Taghavi, Safieh; Vangronsveld, Jaco; van der Lelie, Daniël

2003-01-01

257

In vitro activity of the tricyclic beta-lactam GV104326.  

PubMed Central

GV104326 is a novel tricyclic beta-lactam (a trinem or, formerly, tribactam). The in vitro activity of GV104326 was compared with those of cefuroxime, cefixime, amoxicillin, amoxicillin-clavulanic acid, cefpirome, and ciprofloxacin. GV104326 had in vitro activity generally similar to that of cefixime against members of the family Enterobacteriaceae (MIC at which 90% of the isolates are inhibited [MIC90], < or = 2 micrograms/ml), with cefuroxime and amoxicillin-clavulanic acid being 8- to 32-fold less active and with cefpirome being 4- to 8-fold more active against members of this family. The trinem had no activity against Pseudomonas aeruginosa or Stenotrophomonas maltophilia (MIC90, > 128 micrograms/ml) but was the most active agent against Acinetobacter calcoaceticus. GV104326 was particularly active against gram-positive cocci. Ninety percent of methicillin-susceptible Staphylococcus aureus strains were susceptible to 0.03 microgram of GV104326 per ml, making it the most active agent studied. Enterococci and Lancefield group A and B streptococci were generally equally or somewhat more susceptible to GV104326 than they were to amoxicillin. Streptococcus pneumoniae strains were highly susceptible to GV104326, and those strains which showed decreased susceptibility to penicillin were generally twofold more susceptible to the trinem than to amoxicillin. Haemophilus influenzae and Moraxella catarrhalis were highly susceptible to GV104326 (MIC90s, 0.12 and 0.03 microgram/ml, respectively). The anaerobes Clostridium perfringens, Bacteroides fragilis, and Peptostreptococcus spp. were more susceptible to the trinems (formerly tribactams) than to the other agents studied.

Wise, R; Andrews, J M; Brenwald, N

1996-01-01

258

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

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

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

259

Characterization of skin microbiota in patients with atopic dermatitis and in normal subjects using 16S rRNA gene-based comprehensive analysis.  

PubMed

A previous study using bacterial 16S rRNA gene-based clone libraries revealed that the microbiota in healthy human skin included uncultured micro-organisms, although the micro-organisms in skin exposed to disease conditions remain to be examined. To compare the profiles of skin microbiota in 13 patients with atopic dermatitis (AD) and 10 healthy controls, terminal RFLP analysis of bacterial 16S rRNA genes was applied to 23 swab-scrubbed samples from facial skin. This culture-independent analysis successfully revealed the complex bacterial members of the microbiota as peak patterns following capillary electrophoresis of terminal restriction fragments (T-RFs). Each T-RF peak reflected a micro-organism, and the micro-organism to which each peak was assigned could be identified by computer simulation of T-RF length using the nucleotide sequence data of bacterial species residing in the skin. Among 18 species detected in the study, Stenotrophomonas maltophilia was detected significantly more commonly in AD patients (5/13 for AD patients vs 0/10 for controls), whilst Dietzia maris was detected significantly more commonly in normal controls (8/10 for controls vs 2/13 for AD patients). Moreover, Streptococcus species, which are considered to be uncommon in uninfected skin, were detected in seven patients and eight normal controls. Although further studies should be undertaken to investigate the roles of these micro-organisms in AD, the microbiota were presumed to include hitherto uninvestigated bacterial species in the major population of patients with AD and of healthy controls. PMID:18033838

Dekio, Itaru; Sakamoto, Mitsuo; Hayashi, Hidenori; Amagai, Masayuki; Suematsu, Makoto; Benno, Yoshimi

2007-12-01

260

Air-dust-borne associations of phototrophic and hydrocarbon-utilizing microorganisms: promising consortia in volatile hydrocarbon bioremediation.  

PubMed

Aquatic and terrestrial associations of phototrophic and heterotrophic microorganisms active in hydrocarbon bioremediation have been described earlier. The question arises: do similar consortia also occur in the atmosphere? Dust samples at the height of 15 m were collected from Kuwait City air, and analyzed microbiologically for phototrophic and heterotrophic hydrocarbon-utilizing microorganisms, which were subsequently characterized according to their 16S rRNA gene sequences. The hydrocarbon utilization potential of the heterotrophs alone, and in association with the phototrophic partners, was measured quantitatively. The chlorophyte Gloeotila sp. and the two cyanobacteria Nostoc commune and Leptolyngbya thermalis were found associated with dust, and (for comparison) the cynobacteria Leptolyngbya sp. and Acaryochloris sp. were isolated from coastal water. All phototrophic cultures harbored oil vapor-utilizing bacteria in the magnitude of 10(5) g(-1). Each phototrophic culture had its unique oil-utilizing bacteria; however, the bacterial composition in Leptolyngbya cultures from air and water was similar. The hydrocarbon-utilizing bacteria were affiliated with Acinetobacter sp., Aeromonas caviae, Alcanivorax jadensis, Bacillus asahii, Bacillus pumilus, Marinobacter aquaeolei, Paenibacillus sp., and Stenotrophomonas maltophilia. The nonaxenic cultures, when used as inocula in batch cultures, attenuated crude oil in light and dark, and in the presence of antibiotics and absence of nitrogenous compounds. Aqueous and diethyl ether extracts from the phototrophic cultures enhanced the growth of the pertinent oil-utilizing bacteria in batch cultures, with oil vapor as a sole carbon source. It was concluded that the airborne microbial associations may be effective in bioremediating atmospheric hydrocarbon pollutants in situ. Like the aquatic and terrestrial habitats, the atmosphere contains dust-borne associations of phototrophic and heterotrophic hydrocarbon-utilizing bacteria that are active in hydrocarbon attenuation. PMID:22529000

Al-Bader, Dhia; Eliyas, Mohamed; Rayan, Rihab; Radwan, Samir

2012-11-01

261

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

PubMed

EUCAST breakpoint criteria are being adopted by automatic antimicrobial susceptibility testing systems. The accuracy of the Phoenix Automated System in combination with 2012 EUCAST breakpoints against recent clinical isolates was evaluated. A total of 697 isolates (349 Enterobacteriaceae, 113 Pseudomonas spp., 25 Acinetobacter baumannii, 11 Stenotrophomonas maltophilia, 95 Staphylococcus aureus, 6 coagulase negative staphylococci, 77 enterococci and 21 Streptococcus pneumoniae) with defined resistance phenotypes and well-characterized resistance mechanisms recovered in Spain (n?=?343) and Italy (n?=?354) were tested. Comparator antimicrobial susceptibility testing data were obtained following CLSI guidelines. Experimental agreement (EA), defined as MIC agreement?±1 log(2) dilution, category agreement (CA) and relative discrepancies (minor (mD), major (MD) and very major discrepancies (VMD)) were determined. The overall EA and CA for all organism-antimicrobial agent combinations (n?=?6.294) were 97.3% and 95.2%, respectively. mD, MD and VMD were 4.7%, 1.3% and 2.7%, all of them in agreement with the ISO (ISO20776-2:2007) acceptance criteria for assessment of susceptibility testing devices. VMD were mainly observed in amoxicillin-clavulanate and cefuroxime in Enterobacteriaceae and gentamicin in Pseudomonas aeruginosa, whereas MD were mainly observed in amoxicillin-clavulante in Enterobacteriaceae. mD were mainly observed in Enterobacteriaceae but distributed in different antimicrobials. For S. aureus and enterococci relative discrepancies were low. The Phoenix system showed accuracy assessment in accordance with the ISO standards when using EUCAST breakpoints. Inclusion of EUCAST criteria in automatic antimicrobial susceptibility testing systems will facilitate the implementation of EUCAST breakpoints in clinical microbiology laboratories. PMID:22909279

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

2012-11-01

262

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

PubMed Central

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.

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

263

RISA-HPLC analysis of lung bacterial colonizers of cystic fibrosis children.  

PubMed

Microbiological analysis of sputum samples, from children affected by cystic fibrosis (CF) and showing signs of acute or chronic infections, is routinely performed by culture-dependent approaches involving selective media and biochemical tests. These identification schemes are time-consuming, and may lead to false negative results. The aim of this work was to evaluate the efficacy of a Ribosomal Intergenic Spacer Analysis (RISA) coupled to high performance liquid chromatography (HPLC) for the detection and monitoring of CF lung microbial colonizers including Staphylococcus aureus, Haemophilus influenzae, Pseudomonas aeruginosa, the Burkholderia cepacia complex, Stenotrophomonas maltophilia, and Achromobacter xylosoxidans. These RISA-HPLC analyses were performed over a 10-months period on infants (below 18 months) and children that were or were not yet known to be colonised by P. aeruginosa. The RISA-HPLC profiles were found specific of the patients' microbial communities. A specific P. aeruginosa RISA-HPLC peak corresponding to 550 bp PCR products was recorded, and used to investigate P. aeruginosa persistence through time and after various therapeutic treatments. The RISA-HPLC profiles showed the CF children to be colonized by few bacterial species, and sometimes revealed peaks corresponding to bacterial species that were not detected by the selective plating approaches. Significant RISA-HPLC infra-specific variations were observed for most bacterial colonizers of CF lungs except P. aeruginosa. These species could yield as much as 5 distinct RISA-HPLC peaks, with some of these profiles being strain-specific. RISA-HPLC shows a great potential for revealing colonization by novel emerging pathogens, and for evaluating the efficacy of therapeutic treatments on the global bacterial community of CF lungs. PMID:18929602

Nazaret, S; Assade, F; Brothier, E; Freydičre, A-M; Bellon, G; Cournoyer, B

2009-01-01

264

Diagnostic Value of PCR Analysis of Bacteria and Fungi from Blood in Empiric-Therapy-Resistant Febrile Neutropenia ?  

PubMed Central

This study aimed to assess the clinical utility of PCR for the analysis of bacteria and fungi from blood for the management of febrile neutropenic patients with hematologic malignancies. Using a PCR system able to detect a broad range of bacteria and fungi, we conducted a prospective pilot study of periodic analyses of blood from patients following intensive chemotherapy. When fever occurred, it was treated with empirical antibiotic therapy, basically without knowledge of the PCR results. In 23 febrile episodes during the neutropenic period, bacteria were detected by PCR in 11 cases, while the same species were identified by blood culture in 3 cases. In 10 out of 11 PCR-positive cases, fever could be managed by empirical therapy. In the empirical-therapy-resistant case, the identification of Stenotrophomonas maltophilia by PCR led to improvement of fever. No fungi were detected by PCR in febrile cases, while Aspergillus fumigatus was detected in one afebrile patient, several days before a clinical diagnosis was made. In subsequent sporadic PCR analyses in 15 cases of febrile neutropenia, bacteria were detected by both PCR and blood culture in 7 cases and by PCR alone in 6. Fungi were not detected. While fever was improved by empirical therapy in 12 out of the 13 PCR-positive cases, the identification of Pseudomonas aeruginosa by PCR in one therapy-resistant case contributed to the successful treatment of persistent fever. Our results indicate that PCR analysis of bacteria from blood provides essential information for managing empirical-therapy-resistant febrile neutropenia.

Nakamura, Akiko; Sugimoto, Yuka; Ohishi, Kohshi; Sugawara, Yumiko; Fujieda, Atsushi; Monma, Fumihiko; Suzuki, Kei; Masuya, Masahiro; Nakase, Kazunori; Matsushima, Yoshiko; Wada, Hideo; Katayama, Naoyuki; Nobori, Tsutomu

2010-01-01

265

Biosynthesis and structural characterization of silver nanoparticles from bacterial isolates  

SciTech Connect

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.

Zaki, Sahar, E-mail: saharzaki@yahoo.com [Environmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute, Mubarak City for Scientific Research and Technology Applications, Alexandria, 21934 New Burgelarab City (Egypt)] [Environmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute, Mubarak City for Scientific Research and Technology Applications, Alexandria, 21934 New Burgelarab City (Egypt); El Kady, M.F. [Fabrication Technology Department, Advanced Technology and New Materials Research Institute (ATNMRI), Mubarak City for Scientific Research and Technology Applications, Alexandria (Egypt)] [Fabrication Technology Department, Advanced Technology and New Materials Research Institute (ATNMRI), Mubarak City for Scientific Research and Technology Applications, Alexandria (Egypt); Abd-El-Haleem, Desouky [Environmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute, Mubarak City for Scientific Research and Technology Applications, Alexandria, 21934 New Burgelarab City (Egypt)] [Environmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute, Mubarak City for Scientific Research and Technology Applications, Alexandria, 21934 New Burgelarab City (Egypt)

2011-10-15

266

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

PubMed

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

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

2013-07-01

267

Prevalent bacterial species and novel phylotypes in advanced noma lesions.  

PubMed

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

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

2002-06-01

268

Matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of nonfermenting gram-negative bacilli isolated from cystic fibrosis patients.  

PubMed

The identification of nonfermenting gram-negative bacilli isolated from cystic fibrosis (CF) patients is usually achieved by using phenotype-based techniques and eventually molecular tools. These techniques remain time-consuming, expensive, and technically demanding. We used a method based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) for the identification of these bacteria. A set of reference strains belonging to 58 species of clinically relevant nonfermenting gram-negative bacilli was used. To identify peaks discriminating between these various species, the profile of 10 isolated colonies obtained from 10 different passages was analyzed for each referenced strain. Conserved peaks with a relative intensity greater than 0.1 were retained. The spectra of 559 clinical isolates were then compared to that of each of the 58 reference strains as follows: 400 Pseudomonas aeruginosa, 54 Achromobacter xylosoxidans, 32 Stenotrophomonas maltophilia, 52 Burkholderia cepacia complex (BCC), 1 Burkholderia gladioli, 14 Ralstonia mannitolilytica, 2 Ralstonia pickettii, 1 Bordetella hinzii, 1 Inquilinus limosus, 1 Cupriavidus respiraculi, and 1 Burkholderia thailandensis. Using this database, 549 strains were correctly identified. Nine BCC strains and one R. mannnitolilytica strain were identified as belonging to the appropriate genus but not the correct species. We subsequently engineered BCC- and Ralstonia-specific databases using additional reference strains. Using these databases, correct identification for these species increased from 83 to 98% and from 94 to 100% of cases, respectively. Altogether, these data demonstrate that, in CF patients, MALDI-TOF-MS is a powerful tool for rapid identification of nonfermenting gram-negative bacilli. PMID:18685005

Degand, Nicolas; Carbonnelle, Etienne; Dauphin, Brunhilde; Beretti, Jean-Luc; Le Bourgeois, Muriel; Sermet-Gaudelus, Isabelle; Segonds, Christine; Berche, Patrick; Nassif, Xavier; Ferroni, Agnčs

2008-10-01

269

Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Identification of Nonfermenting Gram-Negative Bacilli Isolated from Cystic Fibrosis Patients?  

PubMed Central

The identification of nonfermenting gram-negative bacilli isolated from cystic fibrosis (CF) patients is usually achieved by using phenotype-based techniques and eventually molecular tools. These techniques remain time-consuming, expensive, and technically demanding. We used a method based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) for the identification of these bacteria. A set of reference strains belonging to 58 species of clinically relevant nonfermenting gram-negative bacilli was used. To identify peaks discriminating between these various species, the profile of 10 isolated colonies obtained from 10 different passages was analyzed for each referenced strain. Conserved peaks with a relative intensity greater than 0.1 were retained. The spectra of 559 clinical isolates were then compared to that of each of the 58 reference strains as follows: 400 Pseudomonas aeruginosa, 54 Achromobacter xylosoxidans, 32 Stenotrophomonas maltophilia, 52 Burkholderia cepacia complex (BCC), 1 Burkholderia gladioli, 14 Ralstonia mannitolilytica, 2 Ralstonia pickettii, 1 Bordetella hinzii, 1 Inquilinus limosus, 1 Cupriavidus respiraculi, and 1 Burkholderia thailandensis. Using this database, 549 strains were correctly identified. Nine BCC strains and one R. mannnitolilytica strain were identified as belonging to the appropriate genus but not the correct species. We subsequently engineered BCC- and Ralstonia-specific databases using additional reference strains. Using these databases, correct identification for these species increased from 83 to 98% and from 94 to 100% of cases, respectively. Altogether, these data demonstrate that, in CF patients, MALDI-TOF-MS is a powerful tool for rapid identification of nonfermenting gram-negative bacilli.

Degand, Nicolas; Carbonnelle, Etienne; Dauphin, Brunhilde; Beretti, Jean-Luc; Le Bourgeois, Muriel; Sermet-Gaudelus, Isabelle; Segonds, Christine; Berche, Patrick; Nassif, Xavier; Ferroni, Agnes

2008-01-01

270

Nonfermenting Gram-Negative Bacilli Infections in a Tertiary Care Hospital in Kolar, Karnataka  

PubMed Central

AIM: Nonfermenting gram-negative bacilli (NFGNB), which are saprophytic in nature, have emerged as important healthcare-associated pathogens. They exhibit resistance not only to beta lactam and the other groups of antibiotics, but also to carbapenems. This study was undertaken to identify the nonfermenters isolated from various clinical samples, to assess their clinical significance, to know the type of healthcare-associated infections they caused, and to know their anti-microbial sensitivity pattern. Materials and Methods: The nonfermenters were identified using a standard protocol that included tests for motility, oxidase production, oxidation-fermentation test for various sugars, gelatin liquefaction, and growth on 10% lactose agar. The clinical significance was assessed by using various criteria and susceptibility testing was performed with the help of the Kirby-Bauer disc diffusion method. Results: A total of 193 NFGNB were isolated from 189 clinical specimens. Pseudomonas aeruginosa was the most common nonfermenter, accounting for 53.8%, followed by Acinetobacter baumannii (22.2%), and Pseudomonas fluorescens (10.8%). Other significant NFGNB isolated were: Sphingobacterium species (5.2%), Acinetobacter lwoffii (3.1%), and Stenotrophomonas maltophilia (2.6%). P. aeruginosa showed good sensitivity to imipenem (94%), cefoperazone (70%), amikacin (69%), and ticarcillin (63%). A. baumannii showed 100% sensitivity to imipenem and 70% sensitivity to piperacillin. Conclusion: P. aeruginosa and A. baumannii were the common NFGNB isolated in our study from patients of, urinary tract infection, bacteremia, surgical site infections, and ventilator associated pneumonia. P. aeruginosa showed good sensitivity to imipenem, amikacin, and cefoperazone while A. baumannii showed good sensitivity to imipenem and piperacillin.

Malini, A; Deepa, EK; Gokul, BN; Prasad, SR

2009-01-01

271

Bacterial reduction of selenium in coal mine tailings pond sediment  

SciTech Connect

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.

Siddique, T.; Arocena, J.M.; Thring, R.W.; Zhang, Y.Q. [University of North British Columbia, Prince George, BC (Canada)

2007-05-15

272

Pathogenic analysis of sputum from ventilator-associated pneumonia in a pediatric intensive care unit  

PubMed Central

Ventilator-associated pneumonia (VAP) is a common and sometimes fatal complication in pediatric intensive care units (PICU). The aim of our study was to characterize the distribution and drug susceptibility of the pathogens isolated from the sputum of patients with VAP in the PICU of our hospital and to provide support to the administration of antibiotics early and reasonably in the clinic. Our study was conducted between January 2007 and December 2011 at the PICU of the Children’s Hospital of Zhejiang University School of Medicine. The endotracheal aspirates were collected and transported to a microbiology laboratory within 15 min. The pathogens were routinely analyzed and identified with Vitek 60 and Kirby-Bauer disk diffusion methods. Among the 121 VAP patients, 127 pathogenic strains were isolated from sputum specimens. Gram-negative and gram-positive bacteria and fungi accounted for 64.57% (82/127), 29.92% (38/127) and 5.51% (7/127), respectively. Acinetobacter baumannii (25.61%), Escherichia coli (20.27%), Stenotrophomonas maltophilia (20.27%), Klebsiella pneumoniae (16.22%) and Pseudomonas aeruginosa (9.46%) were frequently identified isolates among gram-negative bacteria. Staphylococci were susceptible to vancomycin and linezolid. All fungi were sensitive to the antimicrobial agents. The gram-negative bacteria were more prevalent than gram-positive bacteria and fungi in VAP and demonstrated a higher drug resistance. It is important to administer antimicrobial agents early and reasonably for children with VAP. Knowledge of antibiotic resistance and the characteristics of drug resistance is important for VAP prophylaxis and treatment.

NING, BO-TAO; ZHANG, CHEN-MEI; LIU, TAO; YE, SHENG; YANG, ZI-HAO; CHEN, ZHEN-JIE

2013-01-01

273

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

PubMed

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

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

274

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

PubMed

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

Carpentier, Brigitte; Chassaing, Danielle

2004-12-15

275

Early- and Late-Onset Pneumonia: Is This Still a Useful Classification??  

PubMed Central

The choice of empirical treatment of nosocomial pneumonia in the intensive-care unit (ICU) used to rely on the interval after the start of mechanical ventilation. Nowadays, however, the question of whether in fact there is a difference in the distribution of causative pathogens is under debate. Data from 308 ICUs from the German National Nosocomial Infection Surveillance System, including information on relevant pathogens isolated in 11,285 cases of nosocomial pneumonia from 1997 to 2004, were used for our evaluation. Each individual pneumonia case was allocated either to early- or to late-onset pneumonia, with three differentiation criteria: onset on the 4th day, the 5th day, or the 7th day in the ICU. The frequency of pathogens was evaluated according to these categories. A total of 5,066 additional cases of pneumonia were reported from 2005 to 2006, after the CDC criteria had been modified. From 1997 to 2004, the most frequent microorganisms were Staphylococcus aureus (2,718 cases, including 720 with methicillin [meticillin]-resistant S. aureus), followed by Pseudomonas aeruginosa (1,837 cases), Klebsiella pneumoniae (1,305 cases), Escherichia coli (1,137 cases), Enterobacter spp. (937 cases), streptococci (671 cases), Haemophilus influenzae (509 cases), Acinetobacter spp. (493 cases), and Stenotrophomonas maltophilia (308 cases). The order of the four most frequent pathogens (accounting for 53.7% of all pathogens) was the same in both groups and was independent of the cutoff categories applied: S. aureus was first, followed by P. aeruginosa, K. pneumoniae, and E. coli. Thus, the predictabilities of the occurrence of pathogens were similar for the earlier (1997-to-2004) and later (2005-to-2006) time frames. This classification is no longer helpful for empirical antibiotic therapy, since the pathogens are the same for both groups.

Gastmeier, Petra; Sohr, Dorit; Geffers, Christine; Ruden, Henning; Vonberg, Ralf-Peter; Welte, Tobias

2009-01-01

276

[The growing problem of antibiotic resistance in clinically relevant Gram-negative bacteria: current situation].  

PubMed

Resistance to antimicrobial agents in clinically relevant Gram-negative bacteria is an increasingly important problem, which in the last few years has spread from the hospital setting to the community. In enterobacteria, the main features of this situation include resistance to ?-lactams and quinolones. ?-Lactam resistance is caused by intrinsic ?-lactamases, extended-spectrum ?-lactamases, plasmid-mediated cephamycinases and carbapenemses, particularly when produced in strains with decreased permeability because of altered porin expression. Quinolone resistance is a multifactorial problem in which the importance of plasmid-mediated mechanisms (Qnr proteins, acetylase, active efflux pumps) is being recognized. Several studies in Spain and other countries show that strains with these resistance mechanisms are being isolated with increased frequency. Of particular concern is the spread of Escherichia coli and other species producing extended-spectrum ?-lactamases (most frequently of the CTX-M family), affecting outpatients. Very commonly these mechanisms are simultaneously expressed within the same bacterial host, leading to a multiresistance phenotype. This problem is also of major clinical importance in non-fermenting Gram-negative rods, including Pseudomonas aeruginosa and Acinetobacter baumannii and, to a lesser extent, Stenotrophomonas maltophilia and some other species. Multiresistance in non-fermenting organisms results from the presence of intrinsic mechanisms (production of distinct ?-lactamases, decreased permeability and expression of several active efflux pumps) and from the acquisition of exogenous genes. Therapeutic difficulties reach their maximum when bacteria express resistance to carbapenems (a multifactorial problem) or to polymyxins. New compounds with specific activity against multiresistant Gram-negative rods should be developed, which, together with other measures, would contribute to controlling the current serious situation. PMID:21130927

Martínez-Martínez, Luis; Calvo, Jorge

2010-09-01

277

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

PubMed

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

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

2013-11-01

278

Characterization of N2O-producing Xanthomonas-like isolates from biofilters as Stenotrophomonas nitritireducens sp. nov., Luteimonas mephitis gen. nov., sp. nov. and Pseudoxanthomonas broegbernensis gen. nov., sp. nov  

Microsoft Academic Search

A group of yellow-pigmented isolates from ammonia-supplied biofilters showed an unusual denitrification reaction. All strains reduced nitrite but not nitrate without production of nitrogen (N2). The only product found was nitrous oxide (N2O). The strains were divided into two clusters and one separate strain by their fatty acid profiles, which were similar to the fatty acid profiles of the genera

Wolfgang Finkmann; Karlheinz Altendorf; Erko Stackebrandt

279

In Vitro Activity of Ceftaroline against Gram-Positive and Gram-Negative Pathogens Isolated from Patients in Canadian Hospitals in 2009?  

PubMed Central

The in vitro activities of ceftaroline and comparative agents were determined for a collection of the most frequently isolated bacterial pathogens from hospital-associated patients across Canada in 2009 as part of the ongoing CANWARD surveillance study. In total, 4,546 isolates from 15 sentinel Canadian hospital laboratories were tested using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. Compared with other cephalosporins, including ceftobiprole, cefepime, and ceftriaxone, ceftaroline exhibited the greatest potency against methicillin-susceptible Staphylococcus aureus (MSSA), with a MIC90 of 0.25 ?g/ml. Ceftaroline also demonstrated greater potency than ceftobiprole against community-associated methicillin-resistant S. aureus (MRSA) (MIC90, 0.5 ?g/ml) and health care-associated MRSA (MIC90, 1 ?g/ml) and was at least 4-fold more active than other cephalosporins against Staphylococcus epidermidis; all isolates of MSSA and MRSA tested were susceptible to ceftaroline (MIC, ?1 ?g/ml). Against streptococci, including Streptococcus pneumoniae, ceftaroline MICs (MIC90, ?0.03 ?g/ml) were comparable to those of ceftobiprole; however, against penicillin-nonsusceptible, macrolide-nonsusceptible, and multidrug-nonsusceptible isolates of S. pneumoniae, ceftaroline demonstrated 2- to 4-fold and 4- to 16-fold more potent activities than those of ceftobiprole and ceftriaxone, respectively. All isolates of S. pneumoniae tested were susceptible to ceftaroline (MIC, ?0.25 ?g/ml). Among Gram-negative isolates, ceftaroline demonstrated potent activity (MIC90, ?0.5 ?g/ml) against Escherichia coli (92.2% of isolates were susceptible), Klebsiella pneumoniae (94.1% of isolates were susceptible), Proteus mirabilis (97.7% of isolates were susceptible), and Haemophilus influenzae (100% of isolates were susceptible). Ceftaroline demonstrated less potent activity (MIC90, ?4 ?g/ml) against Enterobacter spp., Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella oxytoca, Serratia marcescens, and Stenotrophomonas maltophilia. Overall, ceftaroline demonstrated potent in vitro activity against a recent collection of the most frequently encountered Gram-positive and Gram-negative isolates from patients attending hospitals across Canada in 2009.

Karlowsky, James A.; Adam, Heather J.; DeCorby, Melanie R.; Lagace-Wiens, Philippe R. S.; Hoban, Daryl J.; Zhanel, George G.

2011-01-01

280

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

PubMed

The antibiotic-resistant bacteria are a major concern to wound care because of their ability to resist many of the antibiotics used today to treat infections. Consequently, other antimicrobials, in particular ionic silver, are considered ideal topical agents for effectively helping to manage and prevent local infections. Little is known about the antimicrobial efficacy of ionic silver on antibiotic-resistant bacteria at different pH values. Consequently, in this study our aim was to evaluate the effect of pH on the antimicrobial efficacy of a silver alginate (SA) and a silver carboxymethyl cellulose (SCMC) dressing on antibiotic-resistant bacteria isolated from burn patients. Forty-nine antibiotic-resistant bacteria, including Vancomycin-resistant Enterococcus faecium, meticillin-resistant Staphylococcus aureus, multidrug-resistant (MDR) Pseudomonas aeruginosa, MDR Vibrio sp, MDR Stenotrophomonas maltophilia, extended-spectrum ß-lactamase (ESBL) producing Salmonella sp, ESBL producing Klebsiella pneumoniae, ESBL producing Proteus mirabilis, ESBL producing Escherichia coli and MDR Acinetobacter baumannii, routinely isolated from burn wounds were used in the study and evaluated for their susceptibility to two silver containing wound dressings using a standardised antimicrobial efficacy screening assay [corrected zone of inhibition (CZOI)]. The mean overall CZOI for the Gram-positive isolates at a pH of 5·5 were very similar for both dressings. A mean CZOI of 5 mm was recorded for the SCMC dressing, which was slightly higher, at 5·4 mm for the SA dressing. At a pH of 7·0 both dressings, in general, showed a similar activity. However, at a pH of 8·5 the mean CZOI of the SCMC dressing was found to be significantly (P < 0·05) higher than the SA dressing for a select number of isolates. The mean overall CZOI for the Gram-negative bacteria followed a similar pattern as observed with the Gram-positive bacteria. Susceptibility to silver ions did vary significantly between genera and species of bacteria. Interestingly, when pH was changed from 8·5 to 5·5 antimicrobial activity for both dressings in general increased significantly (P < 0·05). Overall, all forty-nine antibiotic-resistant bacteria isolated from burn wounds showed susceptibility to the antimicrobial activity of both silver containing wound dressings over all pH ranges. In addition, the study showed that the performance of both dressings apparently increased when pH became more acidic. The findings in this study may help to further enhance our knowledge of the role pH plays in affecting both bacterial susceptibility and antimicrobial activity of silver containing wound dressings. PMID:22182219

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

2012-10-01

281

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

PubMed Central

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 24 hours 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?

2013-01-01

282

Studies on the occurrence of Gram-negative bacteria in ticks: Ixodes ricinus as a potential vector of Pasteurella.  

PubMed

A total of 372 Ixodes ricinus ticks (101 females, 122 males, and 149 nymphs) collected by flagging in 6 mixed woodlands of eastern Poland were examined by culture for the presence of internal Gram-negative bacteria other than Borrelia burgdorferi. Adult ticks were examined in pools of 2 specimens each and nymphs were examined in pools of 3-5 specimens each. Ticks were disinfected in 70 % ethanol and homogenized in 0.85% NaCl. The diluted homogenate was inoculated onto 3 kinds of agar media: buffered charcoal yeast extract (BCYE-alpha) for isolation of fastidious Gram-negative bacteria, eosin methylene blue agar (EMB) for isolation of enterobacteria, and tryptic soya agar for isolation of all other non-fastidious Gram-negative bacteria. The Gram-negative isolates were identified with the API Systems 20E and NE microtests. A total of 9 species of Gram-negative bacteria were identified, of which the commonest were strains determined as Pasteurella pneumotropica/haemolytica, which were isolated on BCYE-alpha agar from ticks collected in all 6 examined woodlands. The total number of these strains (49) exceeded the total number of all other strains of Gram-negative bacteria recovered from ticks (30). Of the total number of examined ticks, the minimum infection rate with Pasteurella pneumotropica/haemolytica was highest in females (18.8%), and slightly lower in males (12.3%) and nymphs (10%). Besides Pasteurella pneumotropica/haemolytica, the following species of Gram-negative bacteria were isolated from examined ticks: Pantoea agglomerans, Serratia marcescens, Serratia plymuthica on EMB agar and Aeromonas hydrophila, Burkholderia cepacia, Chromobacterium violaceum, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia on tryptic soya agar. Minimal infection rates with these bacteria were low, ranging from 0.7-5.9%. Of the isolated bacteria, Chromobacterium violaceum, Pasteurella pneumotropica/haemolytica, Pseudomonas aeruginosa, and Serratia marcescens are potentially pathogenic for man and/or animals. In particular, the common occurrence of Pasteurella pneumotropica/haemolytica in Ixodes ricinus ticks poses a potential risk of pasteurellosis for humans and animals exposed to tick bites. PMID:15627343

Stojek, Nimfa Maria; Dutkiewicz, Jacek

2004-01-01

283

In vitro activity of BAY 12-8039, a new fluoroquinolone.  

PubMed

The in vitro activity of BAY 12-8039, a new fluoroquinolone, was studied in comparison with those of ciprofloxacin, trovafloxacin (CP 99,219), cefpodoxime, and amoxicillin-clavulanate against gram-negative, gram-positive, and anaerobic bacteria. Its activity against mycobacteria and chlamydia was also investigated. BAY 12-8039 was active against members of the family Enterobacteriaceae (MIC at which 90% of strains tested were inhibited [MIC90S] < or = 1 microgram/ml, except for Serratia spp. MIC90 2 microgram/ml), Neisseria spp. (MIC90S, 0.015 microgram/ml), Haemophilus influenzae (MIC90, 0.03 microgram/ml), and Moraxella catarrhalis (MIC90, 0.12 micrgram/ml), and these results were comparable to those obtained for ciprofloxacin and trovafloxacin. Against Pseudomonas aeruginosa, the quinolones were more active than the beta-lactam agents but BAY 12-8039 was less active than ciprofloxacin. Strains of Stenotrophomonas maltophilia were fourfold more susceptible to BAY 12-8039 and trovafloxacin (MIC90S, 2 micrograms/ml) than to ciprofloxacin. BAY 12-8039 was as active as trovafloxacin but more active than ciprofloxacin against Streptococcus pneumoniae (MIC90, 0.25 microgram/ml) and methicillin-susceptible Staphylococcus auerus (MIC90S, 0.12 micrograms/ml). The activity of BAY 12-8039 against methicillin-resistant S. aureus (MIC90, 2 micrograms/ml) was lower than that against methicillin-susceptible strains. BAY 12-8039 was active against anaerobes (MIC90S < or = 2 micrograms/ml), being three- to fourfold more active against Bacteroides fragilis, Prevotella spp., and Clostridium difficile than was ciprofloxacin. Against Mycobacterium tuberculosis, BAY 12-8039 exhibited activity comparable to that of rifampin (MICs < or = 0.5 micrograms/ml). Against Chlamydia trachomatis and Chlamydia pneumoniae BAY 12-8039 was more active (MICs < or = 0.12 microgram/ml) than either ciprofloxacin or erythromycin and exhibited a greater lethal effect than either to these two agents. The protein binding of BAY 12-8039 was determined at 1 and 5 micrograms/ml as 30 and 26.4%, respectively. The presence of human serum (at 20 or 70%) had no marked effect on the in vitro activity of BAY 12-8039. PMID:8980763

Woodcock, J M; Andrews, J M; Boswell, F J; Brenwald, N P; Wise, R

1997-01-01

284

Characterization of VIM-2, a Carbapenem-Hydrolyzing Metallo-?-Lactamase and Its Plasmid- and Integron-Borne Gene from a Pseudomonas aeruginosa Clinical Isolate in France  

PubMed Central

Pseudomonas aeruginosa COL-1 was identified in a blood culture of a 39-year-old-woman treated with imipenem in Marseilles, France, in 1996. This strain was resistant to ?-lactams, including ureidopenicillins, ticarcillin-clavulanic acid, cefepime, ceftazidime, imipenem, and meropenem, but remained susceptible to the monobactam aztreonam. The carbapenem-hydrolyzing ?-lactamase gene of P. aeruginosa COL-1 was cloned, sequenced, and expressed in Escherichia coli DH10B. The deduced 266-amino-acid protein was an Ambler class B ?-lactamase, with amino acid identities of 32% with B-II from Bacillus cereus; 31% with IMP-1 from several gram-negative rods in Japan, including P. aeruginosa; 27% with CcrA from Bacteroides fragilis; 24% with BlaB from Chryseobacterium meningosepticum; 24% with IND-1 from Chryseobacterium indologenes; 21% with CphA-1 from Aeromonas hydrophila; and 11% with L-1 from Stenotrophomonas maltophilia. It was most closely related to VIM-1 ?-lactamase recently reported from Italian P. aeruginosa clinical isolates (90% amino acid identity). Purified VIM-2 ?-lactamase had a pI of 5.6, a relative molecular mass of 29.7 kDa, and a broad substrate hydrolysis range, including penicillins, cephalosporins, cephamycins, oxacephamycins, and carbapenems, but not monobactams. As a metallo-?-lactamase, its activity was zinc dependent and inhibited by EDTA (50% inhibitory concentration, 50 ?M). VIM-2 conferred a resistance pattern to ?-lactams in E. coli DH10B that paralleled its in vitro hydrolytic properties, except for susceptibility to ureidopenicillins, carbapenems, and cefepime. blaVIM-2 was located on a ca. 45-kb plasmid that in addition conferred resistance to sulfamides and that was not self-transmissible either from P. aeruginosa to E. coli or from E. coli to E. coli. blaVIM-2 was the only gene cassette located within the variable region of a novel class 1 integron, In56, that was weakly related to the blaVIM-1-containing integron. VIM-2 is the second carbapenem-hydrolyzing metalloenzyme characterized from a P. aeruginosa isolate outside Japan.

Poirel, Laurent; Naas, Thierry; Nicolas, Delphine; Collet, Louis; Bellais, Samuel; Cavallo, Jean-Didier; Nordmann, Patrice

2000-01-01

285

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

PubMed

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

Giamarellou, Helen; Poulakou, Garyphallia

2009-10-01

286

Combination of Chromogenic Differential Medium and estA-Specific PCR for Isolation and Detection of Phytopathogenic Xanthomonas spp.?  

PubMed Central

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.

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

2009-01-01

287

In vitro activity of ceftaroline against gram-positive and gram-negative pathogens isolated from patients in Canadian hospitals in 2009.  

PubMed

The in vitro activities of ceftaroline and comparative agents were determined for a collection of the most frequently isolated bacterial pathogens from hospital-associated patients across Canada in 2009 as part of the ongoing CANWARD surveillance study. In total, 4,546 isolates from 15 sentinel Canadian hospital laboratories were tested using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. Compared with other cephalosporins, including ceftobiprole, cefepime, and ceftriaxone, ceftaroline exhibited the greatest potency against methicillin-susceptible Staphylococcus aureus (MSSA), with a MIC?? of 0.25 ?g/ml. Ceftaroline also demonstrated greater potency than ceftobiprole against community-associated methicillin-resistant S. aureus (MRSA) (MIC??, 0.5 ?g/ml) and health care-associated MRSA (MIC??, 1 ?g/ml) and was at least 4-fold more active than other cephalosporins against Staphylococcus epidermidis; all isolates of MSSA and MRSA tested were susceptible to ceftaroline (MIC, ?1 ?g/ml). Against streptococci, including Streptococcus pneumoniae, ceftaroline MICs (MIC??, ?0.03 ?g/ml) were comparable to those of ceftobiprole; however, against penicillin-nonsusceptible, macrolide-nonsusceptible, and multidrug-nonsusceptible isolates of S. pneumoniae, ceftaroline demonstrated 2- to 4-fold and 4- to 16-fold more potent activities than those of ceftobiprole and ceftriaxone, respectively. All isolates of S. pneumoniae tested were susceptible to ceftaroline (MIC, ?0.25 ?g/ml). Among Gram-negative isolates, ceftaroline demonstrated potent activity (MIC??, ?0.5 ?g/ml) against Escherichia coli (92.2% of isolates were susceptible), Klebsiella pneumoniae (94.1% of isolates were susceptible), Proteus mirabilis (97.7% of isolates were susceptible), and Haemophilus influenzae (100% of isolates were susceptible). Ceftaroline demonstrated less potent activity (MIC??, ?4 ?g/ml) against Enterobacter spp., Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella oxytoca, Serratia marcescens, and Stenotrophomonas maltophilia. Overall, ceftaroline demonstrated potent in vitro activity against a recent collection of the most frequently encountered Gram-positive and Gram-negative isolates from patients attending hospitals across Canada in 2009. PMID:21402844

Karlowsky, James A; Adam, Heather J; Decorby, Melanie R; Lagacé-Wiens, Philippe R S; Hoban, Daryl J; Zhanel, George G

2011-06-01

288

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

PubMed Central

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.

Emerson, D; Moyer, C

1997-01-01

289

Ceftolozane/tazobactam activity tested against Gram-negative bacterial isolates from hospitalised patients with pneumonia in US and European medical centres (2012).  

PubMed

During 2012, a total of 2968 isolates were consecutively collected from 59 medical centres in the USA and 15 European countries from hospitalised patients with pneumonia. Ceftolozane/tazobactam (tazobactam at a fixed concentration of 4mg/L) and comparator agents were tested by reference methods, and MIC endpoints were interpreted by CLSI (2013) and EUCAST (2013) breakpoint criteria. Pseudomonas aeruginosa was the most common isolated pathogen (1019 strains; 34.3%), and ceftolozane/tazobactam was the most active ?-lactam tested against P. aeruginosa (MIC50/90, 0.5/4mg/L; 94.1% inhibited at ?8mg/L). P. aeruginosa exhibited moderate susceptibility to meropenem (MIC50/90, 0.5/>8mg/L; 73.7% susceptible), ceftazidime (MIC50/90, 2/>32mg/L; 73.6% susceptible), cefepime (MIC50/90, 4/>16mg/L; 76.5% susceptible), piperacillin/tazobactam (MIC50/90, 8/>64mg/L; 69.5% susceptible), levofloxacin [MIC50/90, 0.5/>4mg/L; 69.9/61.0% susceptible (CLSI/EUCAST criteria)] and gentamicin (MIC50/90, 2/>8mg/L; 80.7% susceptible). Ceftolozane/tazobactam exhibited activity against many ceftazidime-non-susceptible, meropenem-non-susceptible and piperacillin/tazobactam-non-susceptible, multidrug-resistant (MDR) and extensively drug-resistant (XDR) P. aeruginosa isolates. Ceftolozane/tazobactam was active (MIC50/90, 0.25/4mg/L; 94.6% inhibited at ?8mg/L) against 1530 Enterobacteriaceae, including activity against many MDR and XDR strains. MDR and XDR prevalence varied widely between countries both for P. aeruginosa (24.1% MDR and 17.1% XDR overall) and Enterobacteriaceae (15.4% MDR and 2.7% XDR overall). All ?-lactams had limited activity against Acinetobacter spp. and Stenotrophomonas maltophilia. Ceftolozane/tazobactam demonstrated greater in vitro activity than currently available cephalosporins, carbapenems and piperacillin/tazobactam when tested against P. aeruginosa. In addition, ceftolozane/tazobactam demonstrated greater activity than contemporary cephalosporins and piperacillin/tazobactam when tested against most Enterobacteriaceae. PMID:24856078

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

2014-06-01

290

Persistence of microbial communities including Pseudomonas aeruginosa in a hospital environment: a potential health hazard  

PubMed Central

Background The persistence of microbial communities and how they change in indoor environments is of immense interest to public health. Moreover, hospital acquired infections are significant contributors to morbidity and mortality. Evidence suggests that, in hospital environments agent transfer between surfaces causes healthcare associated infections in humans, and that surfaces are an important transmission route and may act as a reservoir for some of the pathogens. This study aimed to evaluate the diversity of microorganisms that persist on noncritical equipment and surfaces in a main hospital in Portugal, and are able to grow in selective media for Pseudomonas, and relate them with the presence of Pseudomonas aeruginosa. Results During 2 years, a total of 290 environmental samples were analyzed, in 3 different wards. The percentage of equipment in each ward that showed low contamination level varied between 22% and 38%, and more than 50% of the equipment sampled was highly contaminated. P. aeruginosa was repeatedly isolated from sinks (10 times), from the taps’ biofilm (16 times), and from the showers and bedside tables (two times). Two ERIC clones were isolated more than once. The contamination level of the different taps analyzed showed correlation with the contamination level of the hand gels support, soaps and sinks. Ten different bacteria genera were frequently isolated in the selective media for Pseudomonas. Organisms usually associated with nosocomial infections as Stenotrophomonas maltophilia, Enterococcus feacalis, Serratia nematodiphila were also repeatedly isolated on the same equipment. Conclusions The environment may act as a reservoir for at least some of the pathogens implicated in nosocomial infections. The bacterial contamination level was related to the presence of humidity on the surfaces, and tap water (biofilm) was a point of dispersion of bacterial species, including potentially pathogenic organisms. The materials of the equipment sampled could not be related to the microbial contamination level. The presence of a disinfectant in the isolation medium suggests that the number of microorganism in the environment could be higher and shows the diversity of disinfectant resistant species. The statistical analysis suggests that the presence of bacteria could increase the risk of transmission by hand manipulation.

2014-01-01

291

Phenotypic and Genetic Characterization of Carbapenemase and ESBLs Producing Gram-negative Bacteria (GNB) Isolated from Patients with Cystic Fibrosis (CF) in Tehran Hospitals  

PubMed Central

Background: Cystic Fibrosis (CF) is an autosomal recessive genetic disorder in white populations caused by mutation in a gene that encodes Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein. Since frequent respiratory tract infections are the major problem in patients with CF, obligation to identify the causative bacteria and determining their antibiotic resistance pattern is crucial. The purpose of this project was to detect Gram-negative bacteria (GNB) isolated from sputa of CF patients and to determine their antibiotic resistance pattern. Materials and Methods: The sputum of 52 CF patients, treated as inpatients at hospitals in Tehran, was obtained between November 2011 and June 2012. Samples cultured in selective and non-selective media and GNB recognized by biochemical tests. Antimicrobial susceptibility testing to cephalosporins, aminoglycosides and carbapenems was performed by disk diffusion method and MICs of them were measured. For phenotypic detection of carbapenemase and ESBLs production, the Modified Hodge test, double disk synergy test and the combined disk methods were performed. Subsequently, the genes encoding the extended spectrum beta-lactamases (blaPER, blaCTX-M) and carbapenemases (blaIMP-1, blaGES, blaKPC, blaNDM, blaVIM-1, blaVIM-2, blaSPM, blaSIM) in Gram negative bacteria were targeted among the resistant isolates by using PCR. PFGE was used to determine any genetic relationship among the Pseudomonas aeruginosa isolated from these patients. Results: Fifty five GNB were isolated from 52 sputum samples including Pseudomonas aeruginosa, Klebsiella ozaenae, Alcaligenes xylosoxidans, Achromobacter denitrificans, Klebsiella pneumonia and Stenotrophomonas maltophilia. The rates of resistance to different antibiotic were as follows: cefixime (%80), ceftriaxone (%43), ceftazidime (%45) and meropenem (%7). The prevalence of genes encoding the ESBLs and Carbapenemases among the the phenotypically positive strains were as follows: blaCTX-M (19), blaIMP-1 (2), blaVIM-1 (2) and blaVIM-2 (3) genes respectively. No other genes were detected. PFGE analysis revealed 8 genotypes. Six isolates had mutually 3 similar patterns. Conclusion: This study showed the existence of important ESBLs and carbapenemases genes among the GNB isolated from patients with CF. Continuous surveillance of ESBLs and Carbapenemases, also identification of their types, in bacteria isolated from these patients have an important clinical impact, since, it can often provide valuable information for effective infection control measures and for the choice of appropriate antimicrobial therapy.

Vali, Parisa; Shahcheraghi, Fereshteh; Seyfipour, Maryam; Zamani, Maryam Alsadat; Allahyar, Mohammad Reza; Feizabadi, Mohammad Mehdi

2014-01-01

292

Genetic Basis of Long-Chain Aliphatic Hydrocarbon Biosynthesis in Bacteria. Final Technical Report, July 7, 1981-January 6, 1983.  

National Technical Information Service (NTIS)

A variety of Micrococcus species, some related Arthrobacter, and Pseudomonas maltophilia are among the few bacteria which produce significant quantities of long chain aliphatic hydrocarbons. It was the purpose of this investigation to initiate studies aim...

W. E. Kloos

1983-01-01

293

Draft Genome Sequence of Serratia marcescens Strain LCT-SM213  

PubMed Central

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.

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

294

An overview of the kinetic parameters of class B beta-lactamases.  

PubMed Central

The catalytic properties of three class B beta-lactamases (from Pseudomonas maltophilia, Aeromonas hydrophila and Bacillus cereus) were studied and compared with those of the Bacteroides fragilis enzyme. The A. hydrophila beta-lactamase exhibited a unique specificity profile and could be considered as a rather specific 'carbapenemase'. No relationships were found between sequence similarities and catalytic properties. The problem of the repartition of class B beta-lactamases into sub-classes is discussed. Improved purification methods were devised for the P. maltophilia and A. hydrophila beta-lactamases including, for the latter enzyme, a very efficient affinity chromatography step on a Zn(2+)-chelate column. Images Figure 1

Felici, A; Amicosante, G; Oratore, A; Strom, R; Ledent, P; Joris, B; Fanuel, L; Frere, J M

1993-01-01

295

Isolation and characterization of rice straw degrading Streptomyces griseorubens C-5  

Microsoft Academic Search

To reutilize rice straw generated during the agricultural production process, the actinomycete strain C-5 was isolated from\\u000a soil that was under the stook for several years in the Heilongjiang province of China by using multiple selective culture\\u000a media. Strain C-5 was identified as Streptomyces griseorubens by China General Microbiological Culture Collection Center (CGMCC) through morphological and physiological characterization\\u000a combined with

Jie Xu; Qian Yang

2010-01-01

296

Draft Genome Sequence of the Bioelectricity-Generating and Dye-Decolorizing Bacterium Proteus hauseri Strain ZMd44  

PubMed Central

Proteus hauseri ZMd44 (CGMCC 6746), as a crucial biodecolorizing, bioelectricity-generating, and copper-resistant bacterium, is distinguished from the urinary pathogens Proteus penneri and Proteus mirabilis. To further investigate the genetic functions of this strain, the genome sequence and annotation of its open reading frames, which consist of 3,875,927 bp (G+C content, 38.12%), are presented here.

Wang, Nan; Li, Yuzhe; Chen, Yi-Chung; Chen, Bor-Yann; Lu, Yinghua

2014-01-01

297

Medium Optimization Based on Statistical Methodologies for Pristinamycins Production by Streptomyces pristinaespiralis  

Microsoft Academic Search

The optimization of nutrient levels for the production of pristinamycins by Streptomyces pristinaespiralis CGMCC 0957 in submerged fermentation was carried out using the statistical methodologies based on the Plackett–Burman design,\\u000a the steepest ascent method, and the central composite design (CCD). First, the Plackett–Burman design was applied to evaluate\\u000a the influence of related nutrients in the medium. Soluble starch and MgSO4·7H2O

B. Jia; Z. H. Jin; L. H. Mei

2008-01-01

298

Identification of a novel Streptomyces chattanoogensis L10 and enhancing its natamycin production by overexpressing positive regulator ScnRII  

Microsoft Academic Search

A novel Streptomyces strain, L10, which is capable of producing natamycin, was isolated from a soil sample collected from Zhejiang province, China.\\u000a On the basis of phylogenetic analysis of rpoB gene and 16S rDNA sequences, as well as phenotypic comparison, strain L10 (CGMCC 2644) is proposed to be a previously uncharacterized\\u000a strain of S. chattanoogensis. By screening a cosmid library

Yi-Ling Du; Shi-Fei Chen; Liang-Ying Cheng; Xue-Ling Shen; Yuan Tian; Yong-Quan Li

2009-01-01

299

Significantly improved esterase activity of Trichosporon brassicae cells for ketoprofen resolution by 2-propanol treatment  

Microsoft Academic Search

The kinetic resolution of racemic ketoprofen was carried out by enantioselective hydrolysis of ketoprofen ethyl ester using intact cells of Trichosporon brassicae CGMCC0574 as a biocatalyst. After the yeast cells were pretreated by 2vol.% of 2-propanol for 10h, the esterase activity on the (S)-ketoprofen ester increased dramatically, by a factor of ca. 310% without reducing the enantioselectivity of enzymatic resolution.

Duan Shen; Jian-He Xu; Hui-Yuan Wu; You-Yan Liu

2002-01-01

300

Saccharothrix yanglingensis sp. nov., an antagonistic endophytic actinomycete isolated from cucumber plant.  

PubMed

An endophytic actinomycete strain, designated Hhs.015(T), was isolated from roots of cucumber seedlings. The endophytic isolate was identified by means of a polyphasic taxonomic approach. On the basis of 16S rRNA gene sequence similarities, strain Hhs.015(T) was closely related to members of the genus Saccharothrix. DNA-DNA hybridization with the four closest relatives, Saccharothrix longispora NRRL B-16116(T), Saccharothrix xinjiangensis NRRL B-24321(T), Saccharothrix autraliensis CGMCC 4.1355(T) and Saccharothrix espanaensis CGMCC 4.1714(T), gave similarity values of 33.8, 28.2, 44.1 and 29.5%, respectively, which indicated that strain Hhs.015(T) represents a novel species of the genus Saccharothrix. This is consistent with the morphological, physiological and chemotaxonomic data. As a whole, these results suggest that strain Hhs.015(T) represents a novel Saccharothrix species. The name Saccharothrix yanglingensis sp. nov. is proposed, with the type strain Hhs.015(T) (=CGMCC 4.5627(T) = KCTC 19722(T)). PMID:21892613

Yan, Xia; Huang, Li-Li; Tu, Xuan; Gao, Xiao-Ning; Kang, Zhen-Sheng

2012-01-01

301

Metabolic flux analysis of Gluconacetobacter xylinus for bacterial cellulose production.  

PubMed

Metabolic flux analysis was used to reveal the metabolic distributions in Gluconacetobacter xylinus (CGMCC no. 2955) cultured on different carbon sources. Compared with other sources, glucose, fructose, and glycerol could achieve much higher bacterial cellulose (BC) yields from G. xylinus (CGMCC no. 2955). The glycerol led to the highest BC production with a metabolic yield of 14.7 g/mol C, which was approximately 1.69-fold and 2.38-fold greater than that produced using fructose and glucose medium, respectively. The highest BC productivity from G. xylinus CGMCC 2955 was 5.97 g BC/L (dry weight) when using glycerol as the sole carbon source. Metabolic flux analysis for the central carbon metabolism revealed that about 47.96 % of glycerol was transformed into BC, while only 19.05 % of glucose and 24.78 % of fructose were transformed into BC. Instead, when glucose was used as the sole carbon source, 40.03 % of glucose was turned into the by-product gluconic acid. Compared with BC from glucose and fructose, BC from the glycerol medium showed the highest tensile strength at 83.5 MPa, with thinner fibers and lower porosity. As a main byproduct of biodiesel production, glycerol holds great potential to produce BC with superior mechanical and microstructural characteristics. PMID:23640364

Zhong, Cheng; Zhang, Gui-Cai; Liu, Miao; Zheng, Xin-Tong; Han, Pei-Pei; Jia, Shi-Ru

2013-07-01

302

Genetic basis of long-chain aliphatic hydrocarbon biosynthesis in bacteria. Final technical report, July 7, 1981January 6, 1983  

Microsoft Academic Search

A variety of Micrococcus species, some related Arthrobacter, and Pseudomonas maltophilia are among the few bacteria which produce significant quantities of long chain aliphatic hydrocarbons. It was the purpose of this investigation to initiate studies aimed at understanding the genetic basis of aliphatic hydrocarbon production. Results have shown that some strains of several of the Micrococcus species carry plasmids, but

Kloos

1983-01-01

303

Halorubrum salinum sp. nov., isolated from a marine solar saltern.  

PubMed

The halophilic archaeal strain GX71(T) was isolated from the Gangxi marine solar saltern near the Weihai city of Shandong Province, China. Cells of the strain were pleomorphic and lysed in distilled water, stained Gram-negative and formed red-pigmented colonies. Strain GX71(T) was able to grow at 25-45 °C (optimum 30 °C), in the presence of 1.7-4.8 M NaCl (optimum 2.6 M NaCl), with 0.005-0.7 M MgCl2 (optimum 0.05 M MgCl2) and at pH 5.5-9.5 (optimum pH 7.0-7.5). Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 10 % (w/v). The major polar lipids of the strain were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, one major glycolipid chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-3) and an unidentified lipid was also detected. The 16S rRNA gene sequence of strain GX71(T) showed 94.0-97.0 % similarity to members of the genus Halorubrum of the family Halobacteriaceae. The rpoB' gene sequence of strain GX71(T) was 87.3-93.4 % similarity to current members of the genus Halorubrum. The DNA G+C content of GX71(T) was 67.1 mol%. Strain GX71(T) showed low DNA-DNA relatedness with Halorubrum lipolyticum CGMCC 1.5332(T), Halorubrum saccharovorum CGMCC 1.2147(T), Halorubrum kocurii CGMCC 1.7018(T) and Halorubrum arcis CGMCC 1.5343(T), the most closely related members of the genus Halorubrum. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strain GX71(T) represents a novel species of the genus Halorubrum, for which the name Halorubrum salinum sp. nov. is proposed. The type strain is GX71(T) (= CGMCC 1.10458(T) = JCM 17093(T)). PMID:24643450

Zhang, Wen-Jiao; Cui, Heng-Lin

2014-06-01

304

Succession and growth strategy of a spring microbial community from kezhou sinter in china  

PubMed Central

The succession and growth strategy of a spring microbial community under earthquake action were investigated. The majority of pre-earthquake isolates belonged to the Gammaproteobacteria, including two numerically dominant Stenotrophomonas sp. RB25 and Acinetobacter sp. RB11 (r-strategists). The predominant post-earthquake isolates were Alphaproteobacteria, with Rhizobium sp. RA42 (K-strategists) being dominant among these organisms.

Yang, Hongmei; Lou, Kai

2011-01-01

305

Rhizobacterial Volatiles Affect the Growth of Fungi and Arabidopsis thaliana  

Microsoft Academic Search

Volatiles of Stenotrophomonas, Serratia, and Bacillus species inhibited mycelial growth of many fungi and Arabidopsis thaliana (40 to 98%), and volatiles of Pseudomonas species and Burkholderia cepacia retarded the growth to lesser extents. Aspergillus niger and Fusarium species were resistant, and B. cepacia and Staphylococcus epidermidis promoted the growth of Rhizoctonia solani and A. thaliana. Bacterial volatiles provide a new

Anja Vespermann; Marco Kai; Birgit Piechulla

2007-01-01

306

Salinicoccus qingdaonensis sp. nov., isolated from coastal seawater during a bloom of green algae.  

PubMed

A novel Gram-stain-positive, white-pigmented, non-motile, non-sporulating, catalase- and oxidase-positive, strictly aerobic coccus, designated strain ZXM223(T), was isolated from a seawater sample collected from the coast of Qingdao, PR China, during a green algal bloom. It grew at pH 6.0-10.5 and 0-25.0% (w/v) NaCl, with optimum growth at pH 8.5 and 3.0% (w/v) NaCl. Growth occurred at 16-42 °C (optimum at 28 °C). The major fatty acids were anteiso-C(15:0) and iso-C(15:0). Menaquinone 6 (MK-6) was the major respiratory quinone. The polar lipids were phosphatidylglycerol, three unidentified phospholipids and two unknown glycolipids. The peptidoglycan type was L-Lys-Gly(5-6.) The genomic DNA G+C content was 43.5 mol%. Phylogenetic analysis of the 16S rRNA gene sequence placed strain ZXM223(T) within the genus Salinicoccus, with sequence similarity of 92.2-97.1% between ZXM223(T) and the type strains of this genus. The closest relatives were Salinicoccus kunmingensis YIM Y15(T), 'S. salitudinis' YIM-C678 and S. alkaliphilus T8(T). The DNA-DNA relatedness between strain ZXM223(T) and S. kunmingensis CGMCC 1.6302(T) and 'S. salitudinis' CGMCC 1.6299 (=YIM-C678) was 37±3 and 30±2%, respectively. The phenotypic, chemotaxonomic and phylogenetic characteristics and low DNA-DNA relatedness support the proposal of a novel species of the genus Salinicoccus, Salinicoccus qingdaonensis sp. nov., with the type strain ZXM223(T) (=LMG 24855(T) =CGMCC 1.8895(T)). PMID:21498663

Qu, Zhe; Li, Zhao; Zhang, Xiuming; Zhang, Xiao-Hua

2012-03-01

307

Classification of Streptomyces phylogroup pratensis (Doroghazi and Buckley, 2010) based on genetic and phenotypic evidence, and proposal of Streptomyces pratensis sp. nov.  

PubMed

The Streptomyces phylogroup pratensis (Doroghazi and Buckley, 2010) contains isolates obtained from grassy fields, as well as Streptomyces flavogriseus ATCC 33331 and strain CGMCC 4.1868. This latter strain was received as Streptomyces griseoplanus but was subsequently found to be mislabeled, and S. flavogriseus ATCC 33331 (=IAF-45-CD) was shown to be clearly distinct from the type strain S. flavogriseus ATCC 25452(T) (=CGMCC 4.1884(T)). In order to evaluate the taxonomic position of phylogroup pratensis further, sequences of the 16S rRNA gene and five protein-coding housekeeping genes (atpD, gyrB, recA, rpoB and trpB) were determined for six strains of the phylogroup and type strains of 19 related species, which were selected by a BLAST search based on the sequences of the phylogroup. The 16S rRNA gene sequences for the phylogroup were identical to those of eight species belonging to cluster I of the S. griseus clade. However, in all the individual protein-coding gene and MLSA phylogenies, the phylogroup strains without exception formed an obviously distinct cluster that could be equated with a new species status. The phylogenetic evidence for the new species assignment was also supported by corresponding DNA-DNA hybridization values and by phenotypic characteristics. It is therefore proposed that the phylogroup should be classified as Streptomyces pratensis sp. nov., and the type strain is ch24(T) (=CGMCC 4.6829(T)=NRRL B-24916(T)). PMID:23769815

Rong, Xiaoying; Doroghazi, James R; Cheng, Kun; Zhang, Limin; Buckley, Daniel H; Huang, Ying

2013-09-01

308

Antibiotic sensitivity of two Aeromonas and nine Pseudomonas species  

Microsoft Academic Search

An agar dilution method was used to determine thein vitro sensitivity of differentPseudomonas andAeromonas species to sulphonamide, tetracycline, colistin, gentamicin, tobramycin, ampicillin, carbenicillin, and cephaiothin.P. aeruginosa was generally sensitive to carbenicillin, colistin, tobramycin, and gentamicin.P. putida andP. fluorescens were generally resistant to?-lactam antibiotics but sensitive to gentamicin and tobramycin.P. cepacia andP. maltophilia were mostly resistant to colistin, gentamicin and tobramycin.

C.-E. Nord; T. Wadström; B. Wretlind

1975-01-01

309

Heterotetrameric Sarcosine Oxidase: Structure of a Diflavin Metalloenzyme at 1.85 Ĺ Resolution  

Microsoft Academic Search

The crystal structure of heterotetrameric sarcosine oxidase (TSOX) from Pseudomonas maltophilia has been determined at 1.85 Ĺ resolution. TSOX contains three coenzymes (FAD, FMN and NAD+), four different subunits (?, 103 kDa; ?, 44 kDa; ?, 21 kDa; ?, 11 kDa) and catalyzes the oxidation of sarcosine (N-methylglycine) to yield hydrogen peroxide, glycine and formaldehyde. In the presence of tetrahydrofolate, the oxidation of sarcosine is

Zhi-wei Chen; Alshaimaa Hassan-Abdulah; Gouhua Zhao; Marilyn Schuman Jorns; F. Scott Mathews

2006-01-01

310

Multicenter Spanish study of ciprofloxacin susceptibility in gram-negative bacteria. The Spanish Study Group on Quinolone Resistance.  

PubMed

The susceptibility of 2,426 gram-negative bacteria obtained from 18 Spanish hospitals to ciprofloxacin was evaluated. Among different medical centers, susceptibility to ciprofloxacin ranged from 83 to 100% for Enterobacteriaceae, from 35 to 100% for Pseudomonas aeruginosa, from 0 to 100% for Xanthomonas maltophilia, Acinetobacter spp. and other gram-negative non-fermenting bacilli, and from 33 to 100% for Campylobacter spp. All clinical isolates of Haemophilus influenzae, Moraxella catarrhalis and Neisseria gonorrhoeae were susceptible to ciprofloxacin. PMID:7556239

García-Rodríguez, J A; Fresnadillo, M J; García, M I; García-Sánchez, E; García-Sánchez, J E; Trujillano, I

1995-05-01

311

Chemical transformation of toxic metals by a Pseudomonas strain from a toxic waste site  

Microsoft Academic Search

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,

Robert C. Blake; Donna M. Choate; Smriti Bardhan; Nathaniel Revis; Larry L. Barton; Thomas G. Zocco

1993-01-01

312

Studies on the microflora associated with xenic cultures of Entamoeba gingivalis.  

PubMed

The microflora associated with xenic stock cultures (ATCC 30927) of Entamoeba gingivalis, the major protozoan of the human oral cavity, were isolated and identified as Citrobacter diversus, Yersinia enterocolitica, Acinetobacter anitratus and Pseudomonas maltophilia. In studies to determine whether the bacterial isolates were able to utilize rice starch as a sole carbon source, Y. enterocolitica exhibited excellent growth in rice starch minimal medium and TYSGM-9 medium (with rice starch), but growth was weak in TYSGM-9 medium (without rice starch). C. diversus, A. anitratus and P. maltophilia exhibited poor growth in rice starch minimal medium, but they produced excellent growth in TYSGM-9 medium with or without rice starch. In order to determine the effect of the rice starch hydrolysis on Entamoeba growth, the filtrate from each isolate grown in rice starch minimal medium was added to an E. gingivalis culture grown in TYSGM-9 medium. The filtrate from a Y. enterocolitica culture grown in rice starch minimal medium enhanced E. gingivalis growth, but the filtrates from cultures of C. diversus, A. anitratus and P. maltophilia suppressed E. gingivalis growth. This supported the concept that Y. enterocolitica is capable of metabolizing rice starch into intermediate products, which in turn can be utilized by the amoeba. PMID:2739589

Gannon, J T; Linke, H A

1989-01-01

313

Efficacy of bacterial consortium-AIE2 for contemporaneous Cr(VI) and azo dye bioremediation in batch and continuous bioreactor systems, monitoring steady-state bacterial dynamics using qPCR assays  

Microsoft Academic Search

Bacterial consortium-AIE2 with a capability of contemporaneous Cr(VI) reduction and azo dye RV5 decolourization was developed\\u000a from industrial wastewaters by enrichment culture technique. The 16S rRNA gene based molecular analyses revealed that the\\u000a consortium bacterial community structure consisted of four bacterial strains namely, Alcaligenes sp. DMA, Bacillus sp. DMB, Stenotrophomonas sp. DMS and Enterococcus sp. DME. Cumulative mechanism of Cr(VI)

Chirayu Desai; Kunal Jain; Bharat Patel; Datta Madamwar

2009-01-01

314

Biodegradation of Indeno (1,2,3-cd) Pyrene by a Pure Bacterial Culture of Pandoraea sp  

Microsoft Academic Search

Three new isolated bacterial cultures of Pandoraea sp., Stenotrophomonas sp., and T Pseudoxanthomonas mexicana that could efficiently degraded Indeno (1,2,3-cd) pyrene (Inp) were reported in this paper. The biodegradation performance of Inp by Pandoraea sp was studied under different pH conditions. Under the conditions of pH=8, the removal efficiency of Inp fluctuated sharply among 8% and 40%. The optimal condition

Yongchao Du; Junfeng Dou; Lirong Cheng; Aizhong Ding; Fuqiang Fan; Haiying Chen

2010-01-01

315

Construction of River Model Biofilm for Assessing Pesticide Effects  

Microsoft Academic Search

Due to the high importance of biofilms on river ecosystems, assessment of pesticides’ adverse effects is necessary but is\\u000a impaired by high variability and poor reproducibility of both natural biofilms and those developed in the laboratory. We constructed\\u000a a model biofilm to evaluate the effects of pesticides, consisting in cultured microbial strains, Pedobacter sp. 7-11, Aquaspirillum sp. T-5, Stenotrophomonas sp.

Shohei Hayashi; Ji Eun Jang; Kazuhito Itoh; Kousuke Suyama; Hiroki Yamamoto

2011-01-01

316

BIODEGRADATION OF THE ORGANOPHOSPHATE PESTICIDE TETRACHLORVINPHOS BY BACTERIA ISOLATED FROM AGRICULTURAL SOILS IN MÉXICO  

Microsoft Academic Search

A bacterial consortium which degrades tetrachlorvinphos (phosphoric acid, 2-chloro- 1-(2,4,5-trichlorophenyl) ethenyl dimethyl ester) was isolated from agricultural soil. This consortium was composed of six pure strains which were characterized based on their morphological and biochemical characteristics. The strains were presumptively identified as Stenotrophomonas malthophilia, Proteus vulgaris, Vibrio metschinkouii, Serratia ficaria, Serratia spp. and Yersinia enterocolitica. The consortium and the six

Ma. Laura; Enrique SÁNCHEZ-SALINAS

2010-01-01

317

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

Microsoft Academic Search

Forty-one bacterial strains isolated from the headbox water of two machines in a Canadian paper mill were associated with\\u000a the genera Asticcacaulis, Acidovorax, Bacillus, Exiguobacterium, Hydrogenophaga, Pseudomonas, Pseudoxanthomonas, Staphylococcus, Stenotrophomonas based on the sequence of their 16S rRNA genes. The metabolic profile of these strains were determined using Biolog EcoPlate,\\u000a and the bacteria were divided into four metabolic groups. Metabolic

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

2009-01-01

318

Antimicrobial activity of three tick defensins and four mammalian cathelicidin-derived synthetic peptides against Lyme disease spirochetes and bacteria isolated from the midgut  

Microsoft Academic Search

In this study, chemically synthesized tick defensins and cathelicidin-derived mammalian peptides were used to investigate\\u000a the activity spectrum against Borrelia garinii and symbiotic Stenotrophomonas maltophila. Synthetic tick defensins showed antimicrobial activity against Staphylococcus aureus but not B. garinii and S. maltophila. Mammalian peptides which have cationic property similar to tick defensins, showed antimicrobial activity similar to tick\\u000a defensins. The antimicrobial

Emiko Isogai; Hiroshi Isogai; Koichi Takahashi; Michiko Kobayashi-Sakamoto; Kazuhiko Okumura

2009-01-01

319

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

PubMed Central

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.

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

2012-01-01

320

Halorubrum lipolyticum sp. nov. and Halorubrum aidingense sp. nov., isolated from two salt lakes in Xin-Jiang, China.  

PubMed

Two extremely halophilic archaea, strains 9-3(T) and 31-hong(T), were isolated from Aibi salt lake and Aiding salt lake in Xin-Jiang, China. Their morphology, physiology, biochemical features, polar lipid compositions and 16S rRNA gene sequences were characterized in order to elucidate their taxonomic status. The results from this study indicated that strains 9-3(T) and 31-hong(T) are members of the genus Halorubrum. Their physiological properties and polar lipid compositions are clearly different from those of the currently described species of Halorubrum. DNA-DNA relatedness values for strain 9-3(T) with respect to its closely related neighbours Halorubrum saccharovorum JCM 8865(T) and Halorubrum lacusprofundi JCM 8891(T) were 51.6 and 25.1 %, respectively, DNA-DNA relatedness values for strain 31-hong(T) with respect to its closely related neighbours Hrr. saccharovorum JCM 8865(T) and Hrr. lacusprofundi JCM 8891(T) were 29.4 and 44.9 %, respectively, and DNA-DNA relatedness between strains 9-3(T) and 31-hong(T) was 54 %. Thus, two novel species of the genus Halorubrum are proposed, Halorubrum lipolyticum sp. nov. (type strain 9-3(T)=CGMCC 1.5332(T)=JCM 13559(T)) and Halorubrum aidingense sp. nov. (type strain 31-hong(T)=CGMCC 1.2670(T)=JCM 13560(T)). PMID:16825640

Cui, Heng-Lin; Tohty, Dilbr; Zhou, Pei-Jin; Liu, Shuang-Jiang

2006-07-01

321

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

PubMed Central

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

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

2013-01-01

322

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

NASA Astrophysics Data System (ADS)

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

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

2008-08-01

323

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

PubMed

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

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

2010-08-01

324

Kazachstania aquatica sp. nov. and Kazachstania solicola sp. nov., novel ascomycetous yeast species.  

PubMed

The unidentified strains AS 2.0706(T), preserved in the China General Microbiological Culture Collection Center (CGMCC), Academia Sinica, Beijing, China, and CBS 6904(T), preserved in the Centraalbureau voor Schimmelcultures (CBS), Utrecht, The Netherlands, were shown to represent two novel ascomycetous yeast species of the genus Kazachstania by 18S rDNA, internal transcribed spacer (ITS) region (including 5.8S rDNA) and 26S rDNA D1/D2 domain sequence analysis and electrophoretic karyotype comparison. The names Kazachstania aquatica sp. nov. and Kazachstania solicola sp. nov. are proposed for strains AS 2.0706(T) and CBS 6904(T), respectively. Phylogenetically, the two novel species are closely related to Kazachstania aerobia, Kazachstania servazzii and Kazachstania unispora. PMID:16166736

Wu, Zuo-Wei; Bai, Feng-Yan

2005-09-01

325

Halorubrum arcis sp. nov., an extremely halophilic archaeon isolated from a saline lake on the Qinghai-Tibet Plateau, China.  

PubMed

A Gram-negative, aerobic, neutrophilic and extremely halophilic archaeon (strain AJ201(T)), isolated from Ayakekum salt lake on the Qinghai-Tibet Plateau, was investigated by a polyphasic approach. The DNA G+C content of strain AJ201(T) was 65.7 mol%. The major polar lipid profile and phylogenetic analysis based on 16S rRNA gene sequences supported the allocation of the strain to the genus Halorubrum. The results of DNA-DNA hybridizations and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain AJ201(T) from closely related species. Therefore, strain AJ201(T) represents a novel species of the genus Halorubrum, for which the name Halorubrum arcis sp. nov. is proposed. The type strain is strain AJ201(T) (=CGMCC 1.5343(T)=JCM 13916(T)). PMID:17473261

Xu, Xue-Wei; Wu, Yue-Hong; Zhang, Hui-Bin; Wu, Min

2007-05-01

326

Production of sophorolipids with eicosapentaenoic acid and docosahexaenoic acid from Wickerhamiella domercqiae var. sophorolipid using fish oil as a hydrophobic carbon source.  

PubMed

Sophorolipids (SLs) were synthesized by Wickerhamiella domercqiae var. sophorolipid CGMCC 1576 grown on fish oil and glucose. They were purified using preparative HPLC and their structures were identified by MS/MS. The yields of total and lactonic SLs were 47 and 19 g l(-1) in shake-flasks when fish oil 4 % (v/v) was used with glucose in the medium. The composition of SL mixture contained more than 20 SL molecules. Several unconventional SL molecules with eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) including zero-, mono- and di-acetylated acidic SLs with EPA and a di-acetylated acidic SL with DHA were obtained. Two unconventional lactonic SL molecules, non-acetylated lactonic SL with 22:3 and non-acetylated lactonic SL with 20:0, were also obtained. PMID:23386226

Li, Hui; Ma, Xiao-Jing; Wang, Shuang; Song, Xin

2013-06-01

327

Pseudonocardia oroxyli sp. nov., a novel actinomycete isolated from surface-sterilized Oroxylum indicum root.  

PubMed

A high-G+C-content, Gram-positive bacterium, strain D10(T), was isolated from the root of Oroxylum indicum, a Chinese medicinal plant. Based on 16S rRNA gene sequence analysis, strain D10(T) was a member of the genus Pseudonocardia and was most closely related, albeit loosely, to Pseudonocardia halophobica. Morphological and chemotaxonomic characteristics support the affiliation of strain D10(T) to the genus Pseudonocardia. Results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain D10(T) from related Pseudonocardia species. Strain D10(T) (=CGMCC 4.3143(T)=DSM 44984(T)) therefore represents a novel species, for which the name Pseudonocardia oroxyli sp. nov. is proposed. PMID:16957120

Gu, Qiang; Luo, Hongli; Zheng, Wen; Liu, Zhiheng; Huang, Ying

2006-09-01

328

Devosia psychrophila sp. nov. and Devosia glacialis sp. nov., from alpine glacier cryoconite, and an emended description of the genus Devosia.  

PubMed

Two psychrophilic strains, Cr7-05(T) and Cr4-44(T), isolated from alpine glacier cryoconite, were characterized by using a polyphasic approach. Both strains were psychrophilic, showing good growth over a temperature range of 1-20 °C. The chemotaxonomic characteristics of these isolates included the presence of C(18:1)?7c and summed feature 3 (C(16:1)?7c and/or C(16:1)?6c) as the major cellular fatty acids, Q-10 as the predominant ubiquinone and diphosphatidylglycerol, phosphatidylglycerol and unknown glycolipids as major polar lipids. The DNA G+C contents of strains Cr7-05(T) and Cr4-44(T) were 61.4 and 63.6 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two isolates belong to the genus Devosia. The 16S rRNA gene sequence similarity between the two strains was 98.6%, but DNA-DNA hybridization indicated 54% relatedness. Strains Cr7-05(T) and Cr4-44(T) exhibited 16S rRNA gene sequence similarity of 94.7-97.2 and 94.9-96.9%, respectively, to the type strains of recognized Devosia species. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strains Cr7-05(T) and Cr4-44(T) represent two novel species within the genus Devosia, for which the names Devosia psychrophila sp. nov. (type strain Cr7-05(T) =DSM 22950(T) =CGMCC 1.10210(T) =CIP 110130(T)) and Devosia glacialis sp. nov. (type strain Cr4-44(T) =CGMCC 1.10691(T) =LMG 26051(T)) are proposed. An emended description of the genus Devosia is also provided. PMID:21551324

Zhang, De-Chao; Redzic, Mersiha; Liu, Hong-Can; Zhou, Yu-Guang; Schinner, Franz; Margesin, Rosa

2012-03-01

329

Taxonomic evaluation of the Streptomyces hygroscopicus clade using multilocus sequence analysis and DNA-DNA hybridization, validating the MLSA scheme for systematics of the whole genus.  

PubMed

Streptomyces hygroscopicus and related species are the most well known candidate producers of antibiotics and many other industrially and agronomically important secondary metabolites in the genus Streptomyces. Multilocus sequence analysis (MLSA) has shown to be a powerful and pragmatic molecular method for unraveling streptomycete diversities. In this investigation, a multilocus phylogeny of 58 representatives of the S. hygroscopicus 16S rRNA gene clade including S. violaceusniger and related species was examined. The result demonstrated that the MLSA data were helpful in defining members of the S. hygroscopicus clade, providing further evidence that the MLSA scheme of five housekeeping genes (atpD, gyrB, recA, rpoB and trpB) is a valuable alternative for creating and maintaining operational protocols for the Streptomyces species assignment. DNA-DNA hybridization (DDH) between strains with representative MLSA evolutionary distances, combined with previous data from S. griseus and S. albidoflavus clades, revealed a high correlation between MLSA and DDH, and sustains that the five-gene nucleotide sequence distance of 0.007 could be considered as the species cut-off for the whole genus. This significant correlation thus makes the MLSA scheme applicable to construction of a theory-based taxonomy for both ecology and bioprospecting of streptomycetes. Based on the MLSA and DDH data, as well as phenotypic characteristics, 10 species and three subspecies of the S. hygroscopicus clade are considered to be later heterotypic synonyms of eight genomic species, and Streptomyces glebosus sp. nov., comb. nov. (type strain CGMCC 4.1873(T)=LMG 19950(T)=DSM 40823(T)) and Streptomyces ossamyceticus sp. nov., comb. nov. (type strain CGMCC 4.1866(T)=LMG 19951(T)=DSM 40824(T)) are also proposed. PMID:22172557

Rong, Xiaoying; Huang, Ying

2012-02-01

330

Growth in Stewart's medium is a simple, rapid and inexpensive screening tool for the identification of Burkholderia cepacia complex.  

PubMed

Ninety-one percent of Burkholderia cepacia complex reference strains (66 out of 72) displayed a yellow slope-green butt colour reaction after growth in Stewart's medium indicating the oxidation of glucose and the absence of an arginine dihydrolase system. This same colour reaction was observed for Burkholderia gladioli and several Ralstonia species, but not for Pseudomonas aeruginosa, Stenotrophomonas, Achromobacter, Pandoraea and several other Gram-negative non-fermenting bacilli. We therefore consider growth in Stewart's medium a useful, simple, rapid and inexpensive screening test to reduce the number of false positive isolates from B. cepacia complex selective media. PMID:16386966

Vanlaere, Elke; Hansraj, Faiza; Vandamme, Peter A R; Govan, John R W

2006-05-01

331

Characterization of copper-resistant bacteria and bacterial communities from copper-polluted agricultural soils of central Chile  

PubMed Central

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.

2012-01-01

332

Chemical transformation of toxic metals by a Pseudomonas strain from a toxic waste site  

SciTech Connect

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.

Blake, R.C. II; Choate, D.M.; Bardhan, S. (Meharry Medical College, Nashville, TN (United States). Dept. of Biochemistry); Revis, N. (Oak Ridge Research Inst., TN (United States)); Barton, L.L. (Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Biology); Zocco, T.G. (Los Alamos National Lab., NM (United States). Materials Science and Technology Division)

1993-08-01

333

Chemical transformation of toxic metals by a Psuedomonas strain from a toxic waste site  

SciTech Connect

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.

Choate, D.; Blake, R.; Revis, N. (Meharry Medical College, Nashville, TN (United States) Oak Ridge Research Inst., TN (United States))

1991-03-11

334

Controlled clinical evaluation of Isolator and ESP aerobic blood culture systems for detection of bloodstream infections.  

PubMed Central

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.

Kirkley, B A; Easley, K A; Washington, J A

1994-01-01

335

Culture-dependent and culture-independent analysis of hydrocarbonoclastic microorganisms indigenous to hypersaline environments in Kuwait.  

PubMed

The halophilic, hydrocarbonoclastic bacteria and archaea inhabiting two hypersaline coastal areas in Kuwait, one in the north and the other in the south, were counted and characterized. Environmental parameters in both areas were similar, with the exception of the soil organic carbon content, which was in the north higher than in the south. The hydrocarbonoclastic bacterial and haloarchaeal numbers and identities as analyzed using nutrient media of various salinities were similar in soil and pond water samples from both areas. The bacterial species recorded by this culture-dependent method belonged to the genera Halomonas, Chromohalobacter, Marinobacter, Exiguobacterium, Stenotrophomonas, Pseudomonas, Salinivibrio, and Bacillus. The haloarchaeal species belonged to the genera Haloferax and Halobacterium. When analyzed by fingerprinting of their amplified genomic DNA followed by sequencing of the electrophoresis-resolved bands, the same environmental samples revealed a different microbial composition. Bacterial phylotypes recorded by this culture-independent method were affiliated with the genera Ochrobactrum, Stenotrophomonas, Rhodococcus, and "Halomicrobium," whereas the archaeal phylotypes were affiliated with Halorussus, Halomicrobium, and Halorientalis. The observed diversity and composition similarity of the hydrocarbonocalastic microflora in both hypersaline areas suggest an effective potential for oil mineralization therein. This potential has been confirmed experimentally. PMID:24682340

Al-Mailem, Dina; Eliyas, Mohamed; Khanafer, Majeda; Radwan, Samir

2014-05-01

336

Restricted streptomycin use in apple orchards did not adversely alter the soil bacteria communities.  

PubMed

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

Walsh, Fiona; Smith, Daniel P; Owens, Sarah M; Duffy, Brion; Frey, Jürg E

2013-01-01

337

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

PubMed

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

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

2013-04-01

338

Benzoic acid-degrading bacteria from the intestinal tract of Macrotermes michaelseni Sjöstedt.  

PubMed

The intestinal tracts of termites host a wide variety of microbial symbionts, which have been implicated in degradative processes. In this study, a fungus-cultivating termite, Macrotermes michaelseni was found to harbor 2.2 x 10(6) bacterial cells per ml of gut homogenates capable of degrading benzoic acid. Two benzoic acid degrading bacteria were isolated from the highest dilution of gut homogenates in oxic media with benzoic acid as the sole carbon source. Isolate CBC was related to Stenotrophomonas maltophila LMG 958(T), Xanthomonas campestris DSM 3586(T) and Stenotrophomonas acidaminophila DSM 13117(T) with a sequence similarity of 98.3%, 94.7% and 94.2%, respectively. Isolate CBW was related to Enterobacter aerogenes JCM 1235(T) and Raoultella ornithinolytica ATCC 31898(T) with sequence similarity of 98.4% and 97.8%, respectively. In addition to growing on benzoic acid (up to 9 mM) aerobically, isolate CBW also degraded benzoic acid under anoxic conditions with nitrate as electron acceptor. Isolate CBC did not degrade bezoic acid with nitrate but could degraded resorcinol under oxic conditions. PMID:17304624

Kamanda Ngugi, David; Khamis Tsanuo, Muniru; Iddi Boga, Hamadi

2007-02-01

339

Occurrence of non-fermenting gram negative bacteria in drinking water dispensed from point-of-use microfiltration devices.  

PubMed

Introduction and objective. Many devices have been marketed in order to improve the organoleptic characteristics of tap water resulting from disinfection with chlorine derivates. The aim of the presented study was to assess the degree of contamination by non-fermenting Gram-negative bacteria (NF-GNB) of drinking water dispensed from microfiltration devices at point-of-use. Methods. Water samples were collected from 94 point-of-use water devices fitted with a filter (0.5?m pore size) containing powdered activated carbon. The microbiological contamination of water entering and leaving the microfiltered water dispensers was compared. The NF-GNB loads were correlated to Total Heterotrophic Counts (HPCs) at 37 and 22 °C, residua chlorine, and some structural and functional features of the devices. Results. NF-GNB were detected from 23% of supply water samples, 33% of still unchilled water, 33% of still chilled water and 18% of carbonated chilled water. The most frequent isolates were Pseudomonadaceae: Steno.maltophilia 30.2% of isolates, Pseudomonas 20.5%, Delftia acidovorans 13.4%, while the species more largely distributed was Ps. aeruginosa recovered from 13% of samples. The distribution of the various NF-GNB was different in the water entering and in that leaving the devices. Ps.aeruginosa and Steno.maltophilia were the predominant species in water leaving the microfiltration dispensers, probably due to their capacity to colonize the circuits and to prevail over the others. Recovery of NF-GNB was favoured by the reduction in residual chlorine of the supply water, occasional use, the absence of a bacteriostatic element in the filter and inadequate disinfection of the water lines. Conclusions. The presence of high concentrations of potentially pathogenic species of NF-GNB (Ps.aeruginosa, Steno. maltophilia, Burkhol.cepacia) in the water dispensed from microfiltration devices represents a risk of waterborne infections for vulnerable individuals. When these devices are used in environments such as hospitals, nursing homes for the elderly, etc., microbiological monitoring for the detection of NF-GNB is advisable. PMID:24742036

Zanetti, Franza; de Luca, Giovanna; Leoni, Erica; Sacchetti, Rossella

2014-04-01

340

Motion of the Zinc Ions in Catalysis by a di-Zinc Metallo-beta-Lactamase  

SciTech Connect

We report rapid-freeze-quench X-ray absorption spectroscopy of a dizinc metallo-beta-lactamase (MbetaL) reaction intermediate. The Zn(II) ions in the dinuclear active site of the S. maltophilia Class B3 MbetaL move away from each other, by approximately 0.3 A after 10 ms of reaction with nitrocefin, from 3.4 to 3.7 A. Together with our previous characterization of the resting enzyme and its nitrocefin product complex, where the Zn(II) ion separation relaxes to 3.6 A, these data indicate a scissoring motion of the active site that accompanies the ring-opening step. The average Zn(II) coordination number of 4.5 in the resting enzyme appears to be maintained throughout the reaction with nitrocefin. This is the first direct structural information available on early stage dizinc metallo-beta-lactamase catalysis.

R Breece; Z Hu; M Crowder; D Tierney

2011-12-31

341

Analysis of the interaction between autochthonous bacteria and packaging material in PVC-bottled mineral water.  

PubMed

A study with about 10,000 bottles produced by a mineral water company was undertaken in order to identify the causal agent of an off-odour occurrence in the bottled water. Some physiological attributes of the dominant species over an 8-month period, as well as their interaction with packaging material, were investigated. Pseudomonas maltophilia, P. acidovorans, Acinetobacter calcoaceticus var. lowffi, frequently associated with bottles having an off-odour, seemed to play a decisive role in the phenomenon due to their elevated lipolytic activity, their cell hydrophobicity and adhesivity to the PVC walls. Their ability to attack the sodium polysulfide included in the ultramarine blue dye present in PVC, transforming it to H2S was investigated. PMID:7921893

Guerzoni, M E; Lanciotti, R; Sinigaglia, M; Gardini, F

1994-06-01

342

Monoclonal antibodies to Pseudomonas aeruginosa ferripyochelin-binding protein.  

PubMed Central

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

Sokol, P A; Woods, D E

1986-01-01

343

Bu-2470, a new peptide antibiotic complex. I. Production, isolation and properties of Bu-2470 A, B1 and B2.  

PubMed

A strain of Bacillus circulans produced a complex of basic peptide antibiotics designated Bu-2470, which was found to contain four active components, A, B1, B2a and B2b. Bu-2470 A specifically inhibited various Pseudomonas species including P. aeruginosa, P. maltophilia and P. putida, but otherwise its antibacterial spectrum was limited to certain Gram-negative organisms. Bu-2470 B1 and B2 (B2a + B2b) showed broad antibiotic activity against Gram-positive and Gram-negative bacteria including Pseudomonas species. The physicochemical and biological properties of Bu-2470 B1 and B2 are very similar to those of the octapeptin group of antibiotics. PMID:6874583

Konishi, M; Sugawara, K; Tomita, K; Matsumoto, K; Miyaki, T; Fujisawa, K; Tsukiura, H; Kawaguchi, H

1983-06-01

344

Meteorite organics in planetary environments: hydrothermal release, surface activity, and microbial utilization  

NASA Technical Reports Server (NTRS)

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.

Mautner, M. N.; Leonard, R. L.; Deamer, D. W.

1995-01-01

345

Haloarchaeobius litoreus sp. nov., isolated from a marine solar saltern.  

PubMed

Two extremely halophilic archaeal strains GX1(T) and GX60 were isolated from the Gangxi marine solar saltern, China. Cells from the two strains were observed to be rod-shaped and stained Gram-negative, with red-pigmented colonies. Strains GX1(T) and GX60 were found to be able to grow at 25-50 °C (optimum 37 °C), at 1.4-4.8 M NaCl (optimum 2.6 M), at pH 5.5-9.5 (optimum pH 7.0) and neither strain required Mg(2+) for growth. The cells lysed in distilled water and the minimal NaCl concentration to prevent cell-lysis was found to be 8 % (w/v). The major polar lipids of the two strains were identified as phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and three glycolipids chromatographically identical to those of Haloarchaeobius iranensis IBRC-M 10013(T). 16S rRNA gene analysis revealed that each strain had two dissimilar 16S rRNA genes and both strains were phylogenetically related to Hab. iranensis IBRC-M 10013(T) (94.9-98.9 % nucleotide identity). The rpoB' gene similarity between strains GX1(T) and GX60, and between these strains and Hab. iranensis IBRC-M 10013(T) were found to be 99.6, 96.0 and 95.8 %, respectively. The DNA G + C content of strain GX1(T) and GX60 were determined to be 67.7 and 67.8 mol %, respectively. The DNA-DNA hybridization value of strains GX1(T) and GX60 was 86 % and the two strains showed low DNA-DNA relatedness with Hab. iranensis IBRC-M 10013(T) (38 and 32 %). It was concluded that strain GX1(T) (= CGMCC 1.10390(T) = JCM 17114(T)) and strain GX60 (= CGMCC 1.10389 = JCM 17120) represent a new species of Haloarchaeobius, for which the name Haloarchaeobius litoreus sp. nov. is proposed. PMID:24696305

Zhang, Wen-Jiao; Cui, Heng-Lin

2014-06-01

346

Amino acid stability and microbial growth in total parenteral nutrient solutions.  

PubMed

The stability of amino acids in total parenteral nutrient (TPN) solutions stored for 30 days and the potential for stored TPN solutions to support growth of microbial contaminants were studied. Solutions of 3.5% crystalline amino acids and 25% dextrose with electrolytes were prepared either by using a commercially available amino acid solution with electrolytes or by adding electrolytes individually to a base TPN solution. Solutions were stored in polyvinyl chloride bags at refrigerated (4 degrees C) or room (25 degrees C) temperature for 30 days. Some bags were inoculated with Candida albicans or Pseudomonas maltophilia before storage to serve as positive controls for evaluation of microbial contamination. At appropriate intervals, bags of each type of solution under each storage condition were analyzed for amino acid content. Microbial growth was evaluated by filtering the contents of each bag and incubating the filter in brain-heart infusion broth. No microbial growth was detected in any of the study solutions, but all solutions inoculated with C. albicans and 2 of 16 solutions inoculated with Ps. maltophilia had evidence of growth. No significant decreases in the concentrations of any of the amino acids were noted for solutions stored at refrigerated temperature, but significant decreases in the concentrations of arginine and methionine were noted for solutions stored at room temperature. Total parenteral nutrient solutions can be stored for up to 30 days if they are kept at refrigerated temperatures and protected from light; however, quality assurance measures for these solutions should include end-product microbiologic testing. PMID:3936355

Parr, M D; Bertch, K E; Rapp, R P

1985-12-01

347

Synthesis and structural characterization of Pd(II) complexes derived from perimidine ligand and their in vitro antimicrobial studies  

NASA Astrophysics Data System (ADS)

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.

Azam, Mohammad; Warad, Ismail; Al-Resayes, Saud I.; Alzaqri, Nabil; Khan, Mohammad Rizwan; Pallepogu, Raghavaiah; Dwivedi, Sourabh; Musarrat, Javed; Shakir, Mohammad

2013-09-01

348

[Second multicenter study of the in vitro susceptibility to piperacillin-tazobactam].  

PubMed

A study was conducted in 1999 on the activity of piperacillin-tazobactam on 1349 strains collected in a Spanish multicenter study involving 10 hospitals. A total of 897 Gram-negative bacteria of the following genuses were collected: Escherichia coli (169), Klebsiella spp. (112), Pseudomonas spp. (122), Enterobacter spp. (92), Serratia spp. (44), Citrobacter spp. (37), Proteus spp. (114), Morganella spp. (49), Acinetobacter spp. (47), Stenotrophomonas spp. (47), Haemophilus spp. (45), Moraxella spp. (19). The Gram-positive bacteria included Staphylococcus aureus (116), Streptococcus pneumoniae (92), and Enterococcus spp. (114). Piperacillin-tazobactam activity against different anaerobic bacteria was also determined: Bacteroides spp. (88), Clostridium spp. (25), Prevotella spp. (5), Fusobacterium spp. (3) and Peptosteptococcus spp. (9). The piperacillin-tazobactam combination was found to maintain its activity against the isolated microorganisms with regard to the previous study. PMID:12582446

García-Rodríguez, J A; Trujillano, I

2002-06-01

349

Best conditions for biodegradation of diesel oil by chemometric tools.  

PubMed

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

Kaczorek, Ewa; Bielicka-Daszkiewicz, Katarzyna; Héberger, Károly; Kemény, Sándor; Olszanowski, Andrzej; Voelkel, Adam

2014-01-01

350

Best conditions for biodegradation of diesel oil by chemometric tools  

PubMed Central

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.

Kaczorek, Ewa; Bielicka-Daszkiewicz, Katarzyna; Heberger, Karoly; Kemeny, Sandor; Olszanowski, Andrzej; Voelkel, Adam

2014-01-01

351

The Effects of Mary Rose Conservation Treatment on Iron Oxidation Processes and Microbial Communities Contributing to Acid Production in Marine Archaeological Timbers  

PubMed Central

The Tudor warship the Mary Rose has reached an important transition point in her conservation. The 19 year long process of spraying with polyethylene glycol (PEG) has been completed (April 29th 2013) and the hull is air drying under tightly controlled conditions. Acidophilic bacteria capable of oxidising iron and sulfur have been previously identified and enriched from unpreserved timbers of the Mary Rose, demonstrating that biological pathways of iron and sulfur oxidization existed potentially in this wood, before preservation with PEG. This study was designed to establish if the recycled PEG spray system was a reservoir of microorganisms capable of iron and sulfur oxidization during preservation of the Mary Rose. Microbial enrichments derived from PEG impregnated biofilm collected from underneath the Mary Rose hull, were examined to better understand the processes of cycling of iron. X-ray absorption spectroscopy was utilised to demonstrate the biological contribution to production of sulfuric acid in the wood. Using molecular microbiological techniques to examine these enrichment cultures, PEG was found to mediate a shift in the microbial community from a co-culture of Stenotrophomonas and Brevunidimonas sp, to a co-culture of Stenotrophomonas and the iron oxidising Alicyclobacillus sp. Evidence is presented that PEG is not an inert substance in relation to the redox cycling of iron. This is the first demonstration that solutions of PEG used in the conservation of the Mary Rose are promoting the oxidation of ferrous iron in acidic solutions, in which spontaneous abiotic oxidation does not occur in water. Critically, these results suggest PEG mediated redox cycling of iron between valence states in solutions of 75% PEG 200 and 50% PEG 2000 (v/v) at pH 3.0, with serious implications for the future use of PEG as a conservation material of iron rich wooden archaeological artefacts.

Preston, Joanne; Smith, Andrew D.; Schofield, Eleanor J.; Chadwick, Alan V.; Jones, Mark A.; Watts, Joy E. M.

2014-01-01

352

Kroppenstedtia guangzhouensis sp. nov., a thermoactinomycete isolated from soil.  

PubMed

A Gram-stain-positive, spore-forming, aerobic and filamentous thermoactinomycete, designated GD02(T), was isolated from soil in south China. The isolate could grow in the presence of 0-3.0?% NaCl (w/v), at temperatures of 30-60 °C and at pH 5.5-9.5, forming ivory-coloured colonies. When the 16S rRNA gene sequence of the isolate was compared with those of other bacteria, the highest similarity was observed with Kroppenstedtia eburnea DSM 45196(T) (96.1?% 16S rRNA gene sequence similarity). The G+C content of the genomic DNA was 56.3 mol%, the cell-wall peptidoglycan contained ll-diaminopimelic acid, the main polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine and phosphatidylglycerol, and the major menaquinone was MK-7. The major cellular fatty acids (>5?%) were iso-C15?:?0, iso-C16?:?0, iso-C17?:?0 and anteiso-C15?:?0. On the basis of its phenotypic and phylogenetic properties, chemotaxonomic analysis and the results of physiological and biochemical tests, strain GD02(T) (?=?CGMCC 1.12404(T)?=?KCTC 29149(T)) was designated the type strain of a novel species of the genus Kroppenstedtia, for which the name Kroppenstedtia guangzhouensis sp. nov. is proposed. PMID:23728375

Yang, Guiqin; Qin, Dongxing; Wu, Chu; Yuan, Yong; Zhou, Shungui; Cai, Yanfei

2013-11-01

353

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

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

Zhang, Ren-Gang; Tan, Xu; Zhao, Xing-Min; Deng, Jian; Lv, Jie

2014-05-01

354

Colwellia chukchiensis sp. nov., a psychrotolerant bacterium isolated from the Arctic Ocean.  

PubMed

A novel psychrotolerant bacterial strain, BCw111(T), was isolated from seawater samples from the Chukchi Sea in the Arctic Ocean. Cells of strain BCw111(T) were Gram-negative, motile, facultatively anaerobic, curved rods and were able to grow at 0-30 °C (optimum 23-25 °C). Strain BCw111(T) had Q-8 as the major respiratory quinone and contained iso-C(15?:?0) 2-OH and/or C(16?:?1)?7c (28.13?%), C(16?:?0) (13.28?%) and C(17?:?1) (12.90?%) as the major cellular fatty acids. The genomic DNA G+C content was 41.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BCw11(T) formed a distinct lineage within the genus Colwellia and exhibited the highest 16S rRNA gene sequence similarity with Colwellia polaris 537(T) (97.8?%) and Colwellia aestuarii SMK-10(T) (97.1?%). Based on phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness, a novel species, Colwellia chukchiensis sp. nov., is proposed. The type strain is BCw111(T) (?=?CGMCC 1.9127(T) ?=?LMG 25329(T) ?=?DSM 22576(T)). PMID:20495042

Yu, Yong; Li, Hui-Rong; Zeng, Yin-Xin

2011-04-01

355

Optimization of the nutrition for biodegradation of vinasse by Aspergillus oryzae using response surface methodology.  

PubMed

Direct discharge of vinasse from the distillery industry causes resource wasting and environmental destruction due to its mass of organic components. Aspergillus oryzae CGMCC5992 is capable of degrading the organic substrates of wastewater. One-factor-at-a-time design was adopted to select the most important nutrients influencing the degradation of organic materials of vinasse. Box-Behnken Design (BBD) with Design-Expert (8.0.4) was used to develop mathematical model equations, study responses, and optimize concentrations of the key nutrients to improve the degradation efficiency. The optimized medium containing 0.3 g/L urea, 20.73 mg/L ZnSO(4), and 19.79 mg/L vitamin B(6) was supplied to 10-times diluted vinasse; under the optimal condition, a decrease of chemical oxygen demand (COD) from 4,635 to 323 mg/L in vinasse was achieved in 5 days. The reduction of vinasse COD after the optimization of nutrient condition in this study is more significant than those reported previously. PMID:23306254

Zhang, Zhicai; Liu, Dan; Feng, Fan; Li, Jiashao; Li, Ming; Pang, Qiaoxia; Chen, Keping

2013-01-01

356

Oceanicola nanhaiensis sp. nov., isolated from sediments of the South China Sea.  

PubMed

A Gram-negative, non-motile, rod-shaped bacterium, strain SS011B1-20(T), was isolated from sediments of the South China Sea. Growth occurred at NaCl concentrations between 0 and 10 % and at temperatures between 10 and 37 degrees C. Strain SS011B1-20(T) contained Q-10 as the major respiratory quinone and C(18 : 1)omega7c (81.2 %), C(16 : 0) (7.0 %) and C(18 : 1) methyl (4.3 %) as the predominant fatty acids. The G+C content of the genomic DNA was 64.7 mol%. A phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain SS011B1-20(T) belonged to a clade within the genus Oceanicola in the Alphaproteobacteria, the highest sequence similarities being found with respect to Oceanicola batsensis (96.3 %) and with Oceanicola granulosus (94.9 %). Strain SS011B1-20(T) could be clearly distinguished from other Oceanicola species on the basis of the genotypic, phenotypic and phylogenetic data. Thus, it is proposed that strain SS011B1-20(T) represents a novel species of the genus Oceanicola, with the name Oceanicola nanhaiensis sp. nov. The type strain is SS011B1-20(T) (=LMG 23508(T)=CGMCC 1.6293(T)). PMID:17220459

Gu, Jun; Guo, Bin; Wang, Ya-Nan; Yu, Su-Lin; Inamori, Ryuhei; Qu, Ri; Ye, Yu-Guang; Wu, Xiao-Lei

2007-01-01

357

Mameliella alba gen. nov., sp. nov., a marine bacterium of the Roseobacter clade in the order Rhodobacterales.  

PubMed

A Gram-negative, non-motile, rod-shaped bacterial strain, JLT354-W(T), that accumulates poly-beta-hydroxybutyrate granules was isolated from the South China Sea. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain was related to members of the genera Antarctobacter, Sagittula, Oceanicola and Loktanella; levels of similarity between strain JLT354-W(T) and members of the above genera were less than 92.0 %. The predominant fatty acid of strain JLT354-W(T) was C(18 : 1)omega7c (83.1 %); significant amounts of C(18 : 0) (7.9 %) and C(12 : 1) 3-OH (3.7 %) were also present. The predominant respiratory ubiquinone was Q-10. The DNA G+C content of strain JLT354-W(T) was 63.7 mol%. The isolate was distinguishable from members of the order Rhodobacterales based on phenotypic and biochemical characteristics. On the basis of the taxonomic data presented, strain JLT354-W(T) is considered to represent a novel species of a new genus, for which the name Mameliella alba gen. nov., sp. nov. is proposed. The type strain of Mameliella alba is JLT354-W(T) (=LMG 24665(T)=CGMCC 1.7290(T)). PMID:19661508

Zheng, Qiang; Chen, Chuang; Yan, Xiao-Jun; Wang, Ya-Nan; Zeng, Yong-Hui; Hao, Li-Kai; He, Wei-Hong; Jiao, Nian-Zhi

2010-04-01

358

Oceanicola nitratireducens sp. nov., a marine alphaproteobacterium isolated from the South China Sea.  

PubMed

A Gram-negative, non-motile, short-rod-shaped bacterial strain (JLT1210(T)) that accumulates poly-beta-hydroxybutyrate granules was isolated from the Beibu Gulf in the South China Sea. Cells have polar or subpolar flagella. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain belongs to the genus Oceanicola in the order Rhodobacterales, class Alphaproteobacteria. The closest neighbours were Oceanicola nanhaiensis SS011B1-20(T) (96.5 % similarity) and Oceanicola batsensis HTCC2597(T) (96.4 %). The predominant respiratory ubiquinone of strain JLT1210(T) was Q-10 and the DNA G+C content was 72.8 mol%. Evidence from genotypic, chemotaxonomic and phenotypic data shows that strain JLT1210(T) represents a novel species of the genus Oceanicola, for which the name Oceanicola nitratireducens sp. nov. is proposed; the type strain is JLT1210(T) (=LMG 24663(T)=CGMCC 1.7292(T)). PMID:19717582

Zheng, Qiang; Chen, Chuang; Wang, Ya-Nan; Jiao, Nianzhi

2010-07-01

359

Janibacter indicus sp. nov., isolated from hydrothermal sediment of the Indian Ocean.  

PubMed

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?:?1?8c 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

Zhang, Gaiyun; Ren, Huihui; Wang, Shuang; Chen, Xiu; Yang, Yanliu; Zhang, Yubian; Jiang, Yi

2014-07-01

360

Micromonospora violae sp. nov., isolated from a root of Viola philippica Car.  

PubMed

A novel actinomycete, designated strain NEAU-zh8(T), was isolated from a root of Viola philippica Car collected in China and characterized using a polyphasic approach. 16S rRNA gene sequence similarity studies showed that strain NEAU-zh8(T) belongs to the genus Micromonospora, being most closely related to Micromonospora chokoriensis 2-9(6)(T) (99.9 %), Micromonospora saelicesensis Lupac 09(T) (99.3 %) and Micromonospora lupini Lupac 14N(T) (99.0 %). gyrB gene analysis also indicated that strain NEAU-zh8(T) should be assigned to the genus Micromonospora. The cell-wall peptidoglycan consisted of meso-diaminopimelic acid and glycine. The major menaquinones were MK-10(H4), MK-10(H2) and MK-10(H6). The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were iso-C15:0, C16:0 and C17:0 10-methyl. A combination of DNA-DNA hybridization results and some physiological and biochemical properties indicated that strain NEAU-zh8(T) could be readily distinguished from the closest phylogenetic relatives. Therefore, it is proposed that strain NEAU-zh8(T) represents a novel Micromonospora species, for which the name Micromonospora violae sp. nov. is proposed. The type strain is NEAU-zh8(T) (=CGMCC 4.7102(T)=DSM 45888(T)). PMID:24803239

Zhang, Yuejing; Liu, Hui; Zhang, Xinhui; Wang, Shurui; Liu, Chongxi; Yu, Chao; Wang, Xiangjing; Xiang, Wensheng

2014-08-01

361

Chitinolyticbacter meiyuanensis SYBC-H1T, gen. nov., sp. nov., a chitin-degrading bacterium isolated from soil.  

PubMed

A novel aerobic mesophilic bacterial strain SYBC-H1(T) capable of degrading chitin was isolated and classified in this study. The strain exhibited strong chitinolytic activity and was a Gram-negative, curved, rod-shaped, and motile bacterium. Growth of this strain was observed between 10 and 41°C and between pH 3.5 and 9.5. The DNA G + C content of strain SYBC-H1(T) was 53.25 mol%. The cellular fatty acids (>5%) were 12:0 iso 3-OH (5.87%), 16:0 (28.16%), and 18:1?7c (20.48%). Phylogenetic analysis based on 16S rRNA gene sequence similarity revealed that strain SYBC-H1(T) belonged to the family Neisseriaceae, and was distantly related (95.0% similarity) to the genus Chitiniphilus. Its phenotype was unique and genetic and phylogenetic analysis experiments suggested that strain SYBC-H1(T) represented the type strain (CGMCC 3438(T), ATCC BAA-2140(T)) of a novel genus, for which the name Chitinolyticbacter meiyuanensis SYBC-H1(T) gen. nov., sp. nov. was proposed. The highest enzymatic activity of chitinase (9.6 U/ml) was obtained at 72 h in 250 ml shake flasks. The 16S rRNA gene sequence of SYBC-H1(T) has been deposited in GenBank under the accession number GQ981314. PMID:21431834

Hao, Zhikui; Cai, Yujie; Liao, Xiangru; Liang, Xiaohui; Liu, Jiayang; Fang, Zhiyou; Hu, Mingming; Zhang, Dabing

2011-06-01

362

Seohaeicola westpacificensis sp. nov., A Novel Member of Genera Seohaeicola Isolated from Deep West Pacific Sea Water.  

PubMed

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

Xian, Shuhui; Zhang, Rui; Sun, Jia; Chen, Yi; Deng, Wenchao; Li, Shuhui; Jiao, Nianzhi

2014-07-01

363

Arthrobacter cryoconiti sp. nov., a psychrophilic bacterium isolated from alpine glacier cryoconite.  

PubMed

A Gram-stain-positive, aerobic, non-motile, psychrophilic bacterium, designated strain Cr6-08(T), was isolated from alpine glacier cryoconite. Growth of strain Cr6-08(T) occurred at 1-25 °C. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain Cr6-08(T) is most closely related to members of the genus Arthrobacter. Strain Cr6-08(T) possessed chemotaxonomic properties consistent with those of the genus Arthrobacter, such as peptidoglycan type A3? (l-Lys-L-Ala(4)), MK-9(H(2)) as major menaquinone and anteiso- and iso-branched compounds (anteiso-C(15?:?0) and iso-C(15?:?0)) as major cellular fatty acids. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unknown glycolipid and three unknown polar lipids. The genomic DNA G+C content of strain Cr6-08(T) was 57.3 mol%. On the basis of phenotypic and chemotaxonomic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strain Cr6-08(T) is considered to represent a novel species of the genus Arthrobacter, for which the name Arthrobacter cryoconiti sp. nov. is proposed. The type strain is Cr6-08(T) (?=?DSM 23324(T) ?=?LMG 26052(T) ?=?CGMCC 1.10698(T)). PMID:21441372

Margesin, Rosa; Schumann, Peter; Zhang, De-Chao; Redzic, Mersiha; Zhou, Yu-Guang; Liu, Hong-Can; Schinner, Franz

2012-02-01

364

Nocardioides alpinus sp. nov., a psychrophilic actinomycete isolated from alpine glacier cryoconite.  

PubMed

A gram-positive, non-motile, rod-shaped, psychrophilic actinomycete, designated strain Cr7-14(T), was isolated from alpine glacier cryoconite. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Cr7-14(T) was related to members of the genus Nocardioides and shared highest 16S rRNA gene sequence similarities with the type strains of Nocardioides furvisabuli (98.6?%), Nocardioides ganghwensis (98.2?%), Nocardioides oleivorans (98.1?%) and Nocardioides exalbidus (97.6?%). The predominant cellular fatty acids of strain Cr7-14(T) were C(17?:?1)?8c (39.5?%) and iso-C(16?:?0) (32.4?%). The major menaquinone was MK-8(H(4)). The diagnostic diamino acid in the cell-wall peptidoglycan was ll-2,6-diaminopimelic acid. The predominant cell-wall sugars were galactose and rhamnose. The polar lipid pattern contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, four unknown glycolipids and two unknown polar lipids. The genomic DNA G+C content was 71.9 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, a novel species, Nocardioides alpinus sp. nov., is proposed, with Cr7-14(T) (?=?DSM 23325(T)?=?LMG 26053(T)?=?CGMCC 1.10697(T)) as the type strain. PMID:21460134

Zhang, De-Chao; Schumann, Peter; Redzic, Mersiha; Zhou, Yu-Guang; Liu, Hong-Can; Schinner, Franz; Margesin, Rosa

2012-02-01

365

Nonomuraea solani sp. nov., an actinomycete isolated from eggplant root (Solanum melongena L.)  

PubMed Central

A novel actinomycete, designated strain NEAU-Z6T, was isolated from eggplant (Solanum melongena L.) root. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain NEAU-Z6T belonged to the genus Nonomuraea, with highest sequence similarity to Nonomuraea monospora PT 708T (98.83?%), Nonomuraea rosea GW 12687T (98.55?%) and Nonomuraea rhizophila YIM 67092T (98.02?%). Sequence similarities between strain NEAU-Z6T and other species of the genus Nonomuraea ranged from 97.94?% (Nonomuraea candida HMC10T) to 96.30?% (Nonomuraea wenchangensis 210417T). Key morphological, physiological and chemotaxonomic characteristics of strain NEAU-Z6T were congruent with the description of the genus Nonomuraea. The G+C content of the genomic DNA was 64.51 mol%. DNA–DNA relatedness and comparative analysis of physiological, biochemical and chemotaxonomic data allowed genotypic and phenotypic differentiation of strain NEAU-Z6T from closely related species. Thus, strain NEAU-Z6T represents a novel species of the genus Nonomuraea, for which the name Nonomuraea solani sp. nov. is proposed. The type strain is NEAU-Z6T (?=?CGMCC 4.7037T?=?DSM 45729T).

Wang, Xiangjing; Zhao, Junwei; Liu, Chongxi; Wang, Jidong; Shen, Yue; Jia, Feiyu; Wang, Liang; Zhang, Ji; Yu, Chao

2013-01-01

366

Isolation and characterization of Methanoculleus receptaculi sp. nov. from Shengli oil field, China.  

PubMed

Three strictly anaerobic, thermophilic methanogens (ZC-2T, ZC-3 and ZC-6) were isolated from Shengli oil field, China. The 16S rRNA gene sequences of the three strains were nearly identical, possessing > 99.8% sequence similarity. They also possessed high sequence similarity, 97.4%, to Methanoculleus palmolei strain INSLUZ(T) (97.4% and 97.5%, respectively), indicating that they represented a novel species within the genus Methanoculleus. Cells of strain ZC-2T were nonmotile cocci, 0.8-1.7 microm in diameter, and always occurred singly or in pairs. The three strains used H2/CO2 or sodium formate as substrates for methanogenesis but not sodium acetate, trimethylamine, monomethylamine, ethanol, dimethyl sulfide, isopropanol, isobutanol, butan-2-ol or H2/CO. Optimum growth of strain ZC-2T occurred in the presence of 0.2 M NaCl, pH 7.5-7.8 and temperature 50-55 degrees C with a specific growth rate of 0.084 h(-1). The mol% G+C content of the genomic DNA was 55.2 mol%. Based on these phenotypic and phylogenetic characteristics, strains ZC-2T, ZC-3 and ZC-6 are proposed to represent a novel species in the genus Methanoculleus and named Methanoculleus receptaculi sp. nov. The type strain is ZC-2T (CGMCC 1.5087T=DSM 18860T). PMID:18557787

Cheng, Lei; Qiu, Tian-Lei; Li, Xia; Wang, Wei-Dong; Deng, Yu; Yin, Xiao-Bo; Zhang, Hui

2008-08-01

367

Pseudomonas kunmingensis sp. nov., an exopolysaccharide-producing bacterium isolated from a phosphate mine.  

PubMed

A Gram-stain-negative, rod-shaped, exopolysaccharide-producing, strictly aerobic bacterium with a single polar flagellum, designated strain HL22-2(T), was isolated from a phosphate mine situated in a suburb of Kunmming in Yunnan province in south-western China. The taxonomic status of this strain was evaluated by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain HL22-2(T) was related to members of the genus Pseudomonas. 16S rRNA gene sequence similarities between strain HL22-2(T) and Pseudomonas xanthomarina KMM 1447(T), Pseudomonas alcaliphila AL15-21(T) and Pseudomonas stutzeri ATCC 17588(T) were 98.9, 98.10% and 98.06%, respectively. The major cellular fatty acids were C(18 : 1)?7c, C(16 : 0) and summed feature 3 (C(16 : 1)?7c and/or C(16 : 1)?6c). The DNA G+C content was 60.3 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness values, strain HL22-2(T) represents a novel species of the genus Pseudomonas, for which the name Pseudomonas kunmingensis sp. nov. is proposed. The type strain is HL22-2(T) (?=?CGMCC 1.12273(T)?=?DSM 25974(T)). PMID:24225026

Xie, Fuhong; Ma, Huan; Quan, Shujing; Liu, Dehai; Chen, Guocan; Chao, Yapeng; Qian, Shijun

2014-02-01

368

[Breeding of monofluoroacetate-resistant strains of Actinobacillus succinogenes and the mechanism based on metabolic flux analysis].  

PubMed

Succinic acid has received a great deal of attention as an important green chemical stock for the manufacture of synthetic resins, biodegradable polymers and chemical intermediates. In this paper, the breeding mechanism of Actinobacillus succinogenes based on metabolic flux analysis was demonstrated to improve the yield of succinic acid by fermentation. After the NTG treatment, mutants from A. succinogenes CGMCC 1593 which were able to grow in medium containing concentrations of about 50-100 mmol/L of sodium monofluoroacetate were obtained. Among them, a mutant SF-9 was selected for producing more succinic acid and less acetic acid. When fermentations were conducted in a 5 L bioreactors, the final succinic acid concentration of SF-9 (34.8 g/L) increased 23.4%, and the mass ratio of succinic acid/acetic acid increased from 3.3 to 9 compared with those of the parent strain. Based on the metabolic flux analysis of A. succinogenes, PEP was found to be a key node which has an important effect on the production of succinic acid, and the flux ratio of by-productions (acetic, formic, lactic acid) was influenced by PYR node. Compared with the parent strain, the flux to succinic acid of mutant (A. succinogenes SF-9) was significantly increased, while the flux to by-productions had an obvious decline. Therefore, PEP and PYR are not rigid nodes in the metabolic regulation of A. succinogenes. PMID:18589823

Liu, Yupeng; Zheng, Pu; Ni, Ye; Dong, Jinjun; Wei, Ping; Sun, Zhihao

2008-03-01

369

Thermus arciformis sp. nov., a thermophilic species from a geothermal area.  

PubMed

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

Zhang, Xin-Qi; Ying, Yi; Ye, Ying; Xu, Xue-Wei; Zhu, Xu-Fen; Wu, Min

2010-04-01

370

Halorubrum orientale sp. nov., a halophilic archaeon isolated from Lake Ejinor, Inner Mongolia, China.  

PubMed

A motile, pleomorphic, red-pigmented archaeon, strain EJ-52T, was isolated from water from Lake Ejinor, a saline lake in Inner Mongolia, China. Analysis of the almost-complete 16S rRNA gene sequence showed that the isolate was phylogenetically related to species of the genus Halorubrum, being most closely related to Halorubrum saccharovorum ATCC 29252T (96.1% sequence similarity), Halorubrum lacusprofundi JCM 8891T (95.9%), Halorubrum tibetense AS 1.3239T (95.2%), Halorubrum alcaliphilum AS 1.3528T (95.2%) and Halorubrum vacuolatum JCM 9060T (95.1%). The polar lipids of strain EJ-52T were C20C20 derivatives of phosphatidylglycerol phosphate and phosphatidylglycerol phosphate methyl ester and a sulfated diglycosyl diether. Strain EJ-52T requires at least 2.5 M NaCl for growth and grows optimally at 3.4 M NaCl. The strain grows at 25-50 degrees C, with optimal growth occurring at 35-45 degrees C. Mg2+ is not required. The DNA G+C content is 64.2 mol%. On the basis of the data obtained in this study, strain EJ52T represents a novel species, for which the name Halorubrum orientale sp. nov. is proposed. The type strain is EJ-52T (=CECT 7145T=JCM 13889T=CGMCC 1.6295T). PMID:17082390

Castillo, A M; Gutiérrez, M C; Kamekura, M; Xue, Y; Ma, Y; Cowan, D A; Jones, B E; Grant, W D; Ventosa, A

2006-11-01

371

Halorubrum ejinorense sp. nov., isolated from Lake Ejinor, Inner Mongolia, China.  

PubMed

A novel halophilic archaeon, strain EJ-32T, was isolated from water from Lake Ejinor in Inner Mongolia, China. The taxonomy of strain EJ-32T was studied by using a polyphasic approach. On the basis of 16S rRNA gene sequence similarities, strain EJ-32T was shown to be phylogenetically related to Halorubrum coriense (97.9%), Halorubrum trapanicum (97.9%), Halorubrum sodomense (97.8%), Halorubrum tebenquichense (97.8%), Halorubrum xinjiangense (97.6%), Halorubrum terrestre (97.4%), Halorubrum distributum (97.1%) and Halorubrum saccharovorum (96.4%). Strain EJ-32T was found to be neutrophilic, non-motile and Gram-negative. It grew in medium containing saturation concentrations of NaCl and did not require magnesium for optimal growth. The G+C content of the DNA is 64.0 mol%. Values for DNA-DNA hybridization with respect to phylogenetically related Halorubrum species were CGMCC 1.6782T=JCM 14265T). PMID:17978215

Castillo, A M; Gutiérrez, M C; Kamekura, M; Xue, Y; Ma, Y; Cowan, D A; Jones, B E; Grant, W D; Ventosa, A

2007-11-01

372

Halorubrum litoreum sp. nov., an extremely halophilic archaeon from a solar saltern.  

PubMed

An extremely halophilic archaeon, strain Fa-1(T), was isolated from a marine solar saltern in Fujian, China. Strain Fa-1(T) required Mg2+ and at least 2.0 M NaCl for growth. It was able to grow at pH 6.5-9.0 (optimally at pH 7.0-7.5) and at 20-55 degrees C (optimally at 37-42 degrees C). The major polar lipids of strain Fa-1(T) were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and a sulfated diglycosyl diether. On the basis of a 16S rRNA gene sequence analysis, strain Fa-1(T) was closely related to nine species of the genus Halorubrum, showing sequence similarities of 97.4-98.4 %. The G+C content of the DNA of strain Fa-1(T) is 64.9 mol% (Tm). DNA-DNA hybridization values between strain Fa-1(T) and the most closely related members of the genus Halorubrum were below 51 %. On the basis of the data from this study, strain Fa-1(T) represents a novel species of the genus Halorubrum, for which the name Halorubrum litoreum sp. nov. is proposed. The type strain is Fa-1(T) (=CGMCC 1.5336(T) =JCM 13561(T)). PMID:17911283

Cui, Heng-Lin; Lin, Ze-Ying; Dong, Ying; Zhou, Pei-Jin; Liu, Shuang-Jiang

2007-10-01

373

Halorubrum luteum sp. nov., isolated from Lake Chagannor, Inner Mongolia, China.  

PubMed

A novel halophilic archaeon, strain CGSA15(T), was isolated from water of Lake Chagannor in China. The strain grew optimally at 33-37 degrees C, pH 9.5-10.0 and 4.0-4.3 M NaCl. The major polar lipids were phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester. The genomic DNA G+C content of strain CGSA15(T) was 60.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CGSA15(T) was a member of the genus Halorubrum and was related most closely to Halorubrum alkaliphilum AS 1.3528(T) (96.1 % similarity) and Halorubrum tibetense AS 1.3239(T) (96.9 %). Levels of DNA-DNA relatedness between strain CGSA15(T) and Hrr. alkaliphilum AS 1.3528(T) and Hrr. tibetense AS 1.3239(T) were 36.7 and 28.9 %, respectively. According to the phenotypic and genotypic data presented, strain CGSA15(T) is considered to represent a novel species of the genus Halorubrum, for which the name Halorubrum luteum sp. nov. is proposed. The type strain is CGSA15(T) (=CGMCC 1.6783(T) =CECT 7303(T)). PMID:18599720

Hu, Lingfei; Pan, Hailian; Xue, Yanfen; Ventosa, A; Cowan, D A; Jones, B E; Grant, W D; Ma, Yanhe

2008-07-01

374

Identification of a symbiotic fungus from blue-green alga and its extracellular polysaccharide.  

PubMed

A previously unknown symbiotic fungus DT06 has been isolated from the single-celled blue-green alga Chroococcus sp. The sequences of ITS1, 5.8S rDNA and ITS2 regions of DT06 have a high similarity with that of Simplicillium (98%), which is closely related to Simplicillium lanosoniveum based on further phylogenetic analysis. However, DT06 produces unusual exocellular crystals with its conidium size twice that of S. lanosoniveum. Hence, DT06 is proposed to be a varietas of S. lanosoniveum and named as S. lanosoniveum var. Tianjinienss. Dong. (Type specimen was deposited at China General Microbiological Culture Collection Center, Number: CGMCC4460.). The striking character of DT06 is its massive production of a unique extracellular polysaccharide, which is composed of glucose and galactose and linked by 1-4 and 1-6 glycoside bonds according to UV, IR and NMR analysis. Therefore, DT06 may represent a new source of bioactive products, and also, its unusual symbiotic partnership with blue-green algae provides a model for investigating the interaction between photoautotrophic and heterotrophic micro-organisms in aquatic ecosystems. Significance and impact of the study: A novel fungus (Simplicillium) symbiotic with a single-celled blue-green alga Chroococcus sp. and its major primary metabolite have been isolated and identified. These findings broaden the scope of symbiotic fungi and provide a unique extracellular polysaccharide with potential applications in food industry. PMID:24261819

Dong, Q L; Lin, T Y; Xing, X Y; Chen, B; Han, Y

2014-04-01

375

Cloacibacterium rupense sp. nov., isolated from freshwater lake sediment.  

PubMed

A Gram-negative, yellow-pigmented bacterium, designated strain R2A-16(T), was isolated from sediment of Rupa Lake in Nepal and analysed using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain R2A-16(T) is affiliated to the genus Cloacibacterium of the family Flavobacteriaceae; 16S rRNA gene sequence similarity between strain R2A-16(T) and Cloacibacterium normanense CCUG 46293(T) was 98.07 %. The isolate contained iso-C(15 : 0) (35.6 %) as the major fatty acid and menaquinone MK-6 as the predominant respiratory quinone. The G+C content of the genomic DNA was 33.3 mol%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain R2A-16(T) represents a novel species of the genus Cloacibacterium, for which the name Cloacibacterium rupense sp. nov. is proposed; the type strain is R2A-16(T) (=CGMCC 1.7656(T) =NBRC 104931(T)). PMID:19819999

Cao, Shu-Juan; Deng, Chun-Ping; Li, Bao-Zhen; Dong, Xiu-Qin; Yuan, Hong-Li

2010-09-01

376

Methanospirillum psychrodurum sp. nov., isolated from wetland soil.  

PubMed

A psychrotolerant methanogenic strain, X-18(T), was isolated from the soil of the Madoi wetland at Qinghai, Tibetan plateau, China. Cells were wavy rods (11-62 µm long) with blunt tapered ends and Gram-stain-negative. Strain X-18(T) grew strictly anaerobically and produced methane exclusively from H2/CO2. Growth occurred in the temperature range of 4-32 °C and optimally at 25 °C. Growth pH ranged from 6.5 to 8.0 and the optimum was 7.0. The G+C content of the genomic DNA of strain X-18(T) was 44.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences and the alpha subunit of methyl-coenzyme M reductase indicated that strain X-18(T) was affiliated to the genus Methanospirillum and was most closely related to Methanospirillum lacunae Ki8-1(T), with 96.3% 16S rRNA gene sequence similarity. However, strain X-18(T) could be distinguished from the existing species of the genus Methanospirillum by its lower growth temperature and obligate hydrogenotrophic methanogenesis. On the basis of phenotypic characteristics and phylogenetic analysis, strain X-18(T) represents a novel species of the genus Methanospirillum, for which the name Methanospirillum psychrodurum sp. nov. is proposed and strain X-18(T) is assigned as the type strain (?=?CGMCC 1.5186(T)?=?JCM 19216(T)). PMID:24158951

Zhou, Liguang; Liu, Xiaoli; Dong, Xiuzhu

2014-02-01

377

Efficient Production of d-Tagatose Using a Food-Grade Surface Display System.  

PubMed

d-Tagatose, a functional sweetener, is commonly transformed from d-galactose by l-arabinose isomerase (l-AI). In this study, a novel type of biocatalyst, l-AI from Lactobacillus fermentum CGMCC2921 displayed on the spore surface of Bacillus subtilis 168, was developed for producing d-tagatose. The anchored l-AI, exhibiting the relatively high bioactivity, suggested that the surface display system using CotX as the anchoring protein was successfully constructed. The stability of the anchored l-AI was significantly improved. Specifically, the consolidation of thermal stability representing 87% of relative activity was retained even at 80 °C for 30 min, which remarkably favored the production of d-tagatose. Under the optimal conditions, the robust spores can convert 75% d-galactose (100 g/L) into d-tagatose after 24 h, and the conversion rate remained at 56% at the third cycle. Therefore, this biocatalysis system, which could express the target enzyme on the food-grade vector, was an alternative method for the value-added production of d-tagatose. PMID:24979201

Liu, Yi; Li, Sha; Xu, Hong; Wu, Lingtian; Xu, Zheng; Liu, Jing; Feng, Xiaohai

2014-07-16

378

Production of galacto-oligosaccharides by immobilized recombinant beta-galactosidase from Aspergillus candidus.  

PubMed

The preparation of galacto-oligosaccharides (GOSs) was studied using the immobilized recombinant beta-galactosidase from Aspergillus candidus CGMCC3.2919. The optimal pH and temperature for the immobilized enzyme were observed at pH 6.5 and 40 degrees C, respectively. Increasing the initial lactose concentration increased the yield of GOSs. The dilution rate was found to be a key factor during the continuous production of GOSs. The maximum productivity, 87 g/L.h was reached when 400 g/L lactose was fed at dilution rate of 0.8/h. The maximum GOS yield reached 37% at dilution rate of 0.5/h. Continuous operation was maintained for 20 days in a packed-bed reactor without apparent decrease in GOS production. The average yield of GOSs was 32%, corresponding to the average productivity of 64 g/L.h, which implied that the immobilized recombinant beta-galactosidase has potential application for GOS production. PMID:17161020

Zheng, Pu; Yu, Hongfeng; Sun, Zhihao; Ni, Ye; Zhang, Wei; Fan, Yunliu; Xu, Yan

2006-12-01

379

Cellulomonas carbonis sp. nov., isolated from coal mine soil.  

PubMed

A Gram-positive, aerobic, motile, rod-shaped bacterium, designated strain T26(T), was isolated from subsurface soil of Tianjin coal mine, China. Colonies were yellow-white, convex, circular, smooth and non-transparent on R2A agar. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain T26(T) was closely related to members of the genus Cellulomonas and a member of the genus Actinotalea with 96.8-94.7% and 96.7% gene sequence similarities, respectively. The peptidoglycan type of strain T26(T) was A4?, containing l-ornithine-d-glutamic acid as the interpeptide bridge. The cell-wall sugars were rhamnose, galactose, xylose and inositol. The major fatty acids (>10%) were anteiso-C(15:0) (33.6%), anteiso-C(15:1) A (22.1%), C(16:0) (14.4%) and C(14:0) (12.1%). The predominant respiratory quinone was MK-9(H(4)) and the genomic DNA G+C content was 74.4 mol%. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol-mannosides and phosphatidylinositol. Comparison of phenotypic and phylogenetic characteristics between strain T26(T) and related organisms revealed that the new isolate represented a novel species of the genus Cellulomonas, for which the name Cellulomonas carbonis sp. nov. is proposed. The type strain is T26(T) (?=?CGMCC 1.10786(T)?=?KCTC 19824(T)?=?CCTCC AB2010450(T)). PMID:22021576

Shi, Zunji; Luo, Guosheng; Wang, Gejiao

2012-08-01

380

Sediminibacterium salmoneum gen. nov., sp. nov., a member of the phylum Bacteroidetes isolated from sediment of a eutrophic reservoir.  

PubMed

Strain NJ-44(T), isolated from sediment of the eutrophic Guanting Reservoir in Beijing (China), was subjected to a taxonomic study using a polyphasic approach. The strain was aerobic, with salmon-pink-pigmented colonies on R2A agar. Cells were single, Gram-negative rods, motile by gliding. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain NJ-44(T) belonged to the phylum Bacteroidetes, with Terrimonas ferruginea ATCC 13524(T) (90.8% similarity), Terrimonas lutea DY(T) (90.5%) and Niabella aurantiaca R2A15-11(T) (89.1%) as its closest relatives. Strain NJ-44(T) was clearly differentiated from members of the genera Terrimonas and Niabella in its DNA G+C content (40.6 mol%) and its major fatty acids, iso-C(15:1) G, iso-C(15:0), anteiso-C(15:0), iso-C(16:0) 3-OH, iso-C(17:0) 3-OH, anteiso-C(15:1) A and iso-C(15:0) 3-OH. It is proposed that strain NJ-44(T) represents a novel genus and species, named Sediminibacterium salmoneum gen. nov., sp. nov. The type strain of Sediminibacterium salmoneum is strain NJ-44(T) (=CGMCC 1.6845(T) =NBRC 103935(T)). PMID:18768628

Qu, Jian-Hang; Yuan, Hong-Li

2008-09-01

381

Bacillus oceanisediminis sp. nov., isolated from marine sediment.  

PubMed

A Gram-stain-positive, spore-forming, rod-shaped and aerobic bacterium was isolated from a sediment sample from the South Sea in China. The isolate, designated H2(T), grew at 4-45 °C (optimum 37 °C) and pH 6-10 (optimum pH 7.0). The cell-wall peptidoglycan contained meso-diaminopimelic acid. The major isoprenoid quinone was MK-7 and the polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unknown aminophospholipid. The major fatty acid was iso-C(15?:?0). The genomic DNA G+C content of strain H2(T) was 44.8mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate formed a monophyletic clade with Bacillus firmus IAM 12464(T). DNA-DNA relatedness between the isolate and B. firmus ATCC 14575(T) was low (27.5?%). Strain H2(T) also had a phenotypic profile that readily distinguished it from its closest phylogenetic neighbours. It is evident from the combination of genotypic and phenotypic data that the organism should be classified in a novel species of the genus Bacillus, for which the name Bacillus oceanisediminis sp. nov. is proposed. The type strain is H2(T) (=CGMCC 1.10115(T) =JCM 16506(T)). PMID:20118297

Zhang, Jianli; Wang, Jiewei; Fang, Caiyuan; Song, Fei; Xin, Yuhua; Qu, Lei; Ding, Kai

2010-12-01

382

Asanoa hainanensis sp. nov., isolated from rhizosphere soil of Acrostichum speciosum in a mangrove, and emended description of the genus Asanoa.  

PubMed

A Gram-reaction-positive, non-motile actinobacterium, designated strain 210121(T), was isolated from rhizosphere soil of the mangrove fern Acrostichum speciosum. 16S rRNA gene sequence analysis showed that the