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Comparative Biochemistry and... Dec 2008Two partial mRNA sequences predicted to encode anti-lipopolysaccharide factors (ALFs) were identified among expressed sequence tags generated from the American lobster...
Two partial mRNA sequences predicted to encode anti-lipopolysaccharide factors (ALFs) were identified among expressed sequence tags generated from the American lobster Homarus americanus and complete cDNA sequences were obtained from library clones. Comparison of the translated amino acid sequences to those publicly available confirmed similarity to arthropod anti-lipopolysaccharide factors. Both protein sequences, designated ALFHa-1 and ALFHa-2, contained an N-terminal signal peptide and two half-cysteines participating in a disulfide bridge, features conserved in other ALFs. Predicted secondary structures were similar to that described for the ALF from the horseshoe crab Limulus polyphemus. As part of an exploratory study of immunity in H. americanus, lobsters were injected with the bacterium Vibrio fluvialis and gill, hematopoietic, and hepatopancreas tissues were sampled for analysis of gene expression of ALFHa-1 and ALFHa-2 by quantitative PCR. The relative abundance of ALFHa-2 mRNA was not significantly affected by Vibrio injection in any of the three tissues tested. In contrast, ALFHa-1 mRNA levels in gills were increased by the treatment some 17-fold. Our results support a molecularly specific regulation of antimicrobial proteins in response to bacterial infection in H. americanus.
PubMed: 19956341
DOI: 10.1016/j.cbd.2008.07.001 -
FEMS Microbiology Ecology Apr 2008Circulation of mobile genetic elements linked to drug resistance spread was studied in Vibrio strains isolated from surface urban water (river and sea) and shellfish...
Circulation of mobile genetic elements linked to drug resistance spread was studied in Vibrio strains isolated from surface urban water (river and sea) and shellfish samples in 2002-2003 in Maputo, Mozambique. Class 1 integrons and integrating conjugative elements (ICE) were investigated by PCR and mating experiments in strains of major health interest: 10 Vibrio cholerae, six Vibrio parahaemolyticus, two Vibrio alginolyticus and one Vibrio fluvialis. Resistance to at least two antibiotics (predominantly beta-lactams) was detected in all the strains, with additional resistances to sulfamethoxazole, spectinomycin, streptomycin and/or trimethoprim. Class 1 integrons contributed partially to the expression of drug resistance and were found in five isolates: four V. cholerae (blaP1 cassette, one strain also contained the dfrA15 cassette) and one V. alginolyticus (aadA2 cassette). ICEs, apparently devoid of resistance genes, were found in eight V. cholerae, three V. parahaemolyticus and one V. fluvialis isolates. A wide variability was observed by molecular characterization of ICEs. Five ICEs were included in the SXT/R391 family and seven ICEs were not classified. Our results indicate that the SXT/R391 family and related ICEs comprise a large class of polymorphic genetic elements widely circulating in environmental Vibrio strains in Africa, beside those evidently linked to drug resistance in clinical isolates.
Topics: Animals; Conjugation, Genetic; DNA Transposable Elements; Drug Resistance, Bacterial; Humans; Integrons; Mozambique; Polymerase Chain Reaction; Polymorphism, Genetic; Rivers; Seawater; Shellfish; Vibrio; beta-Lactams
PubMed: 18318712
DOI: 10.1111/j.1574-6941.2008.00455.x -
Revista Chilena de Infectologia :... Jun 2007Extraintestinal infections caused by the genera Aeromonas, Vibrio and Plesiomonas have high morbidity and mortality rates in different areas of world. From January 2002...
Extraintestinal infections caused by the genera Aeromonas, Vibrio and Plesiomonas have high morbidity and mortality rates in different areas of world. From January 2002 to December 2003, the National Reference Laboratory for Acute Diarrhoeal Diseases of the Pedro Kourà Tropical Medicine Institute received 95 gram-negative, facultative anaerobic, oxidase positive bacilli strains from different extraintestinal specimen (blood, ear exudates, infected wounds, conjunctive exudates, urine, and catheters, among others) sent by different provincial laboratories along the country. Aeromonas caviae, Aeromonas veronii bv sobria, Aeromonas jandaei, Vibrio cholerae no-O1, Vibrio vulnificus, Vibrio fluvialis and Plesiomonas shigelloides were the species most frequently found in the sample analysed.
Topics: Aeromonas; Bacterial Typing Techniques; Cuba; Humans; Plesiomonas; Vibrio cholerae
PubMed: 17554439
DOI: 10.4067/s0716-10182007000300005 -
Microbiological Research 2008The viability of Vibrio fluvialis in seawater microcosms, with and without sediment was investigated. The strain survived as culturable bacteria for at least 1 year and...
The viability of Vibrio fluvialis in seawater microcosms, with and without sediment was investigated. The strain survived as culturable bacteria for at least 1 year and the expression of its virulence factors was maintained. In microcosms containing sediment Vibrio fluvialis was more stable. Viable but nonculturable (VBNC) cells of Vibrio fluvialis were able to resuscitate to the culturable state up to 6 years of incubation in marine sediment. These cells recuperate their initial biochemical characteristics after 3 months of incubation in marine broth. Amplified 16S ribosomal DNA (rDNA) restriction analysis (ARDRA) was used to confirm that it is the same strain of Vibrio fluvialis which resists in all microcosms during a long period of time.
Topics: Colony Count, Microbial; Geologic Sediments; Microbial Viability; Ribotyping; Seawater; Vibrio; Virulence Factors
PubMed: 16870413
DOI: 10.1016/j.micres.2006.06.006 -
Antimicrobial Agents and Chemotherapy Jul 2006The molecular mechanisms of drug resistance in 19 strains of Vibrio fluvialis isolated from 1998 to 2002 in Kolkata, India, were investigated. Class 1 integrons were...
The molecular mechanisms of drug resistance in 19 strains of Vibrio fluvialis isolated from 1998 to 2002 in Kolkata, India, were investigated. Class 1 integrons were detected in eight strains, and four strains were found to carry SXT integrases. In the presence of carbonyl cyanide m-chlorophenylhydrazone or reserpine, all nalidixic acid- and ciprofloxacin-resistant strains became sensitive, suggesting that drug efflux plays a major role in quinolone resistance in V. fluvialis. It was further seen that strains which had MICs of > 25 microg/ml for nalidixic acid had a sense mutation (Ser to Ile) at position 83 of the quinolone resistance-determining region of gyrA. All except one of the integron- and SXT integrase-bearing strains belonged to the same ribotype.
Topics: Anti-Bacterial Agents; DNA Gyrase; Drug Resistance, Bacterial; Hospitalization; Humans; India; Integrases; Integrons; Microbial Sensitivity Tests; Mutation; Nalidixic Acid; Plasmids; Quinolones; Vibrio; Vibrio Infections
PubMed: 16801422
DOI: 10.1128/AAC.01561-05 -
Applied and Environmental Microbiology Aug 2005A novel high-throughput screening method that overcame product inhibition was used to isolate a mutant omega-transaminase from Vibrio fluvialis JS17. An enzyme library...
A novel high-throughput screening method that overcame product inhibition was used to isolate a mutant omega-transaminase from Vibrio fluvialis JS17. An enzyme library was generated using error-prone PCR mutagenesis and then enriched on minimal medium containing 2-aminoheptane as the sole nitrogen source and 2-butanone as an inhibitory ketone. An identified mutant enzyme, omega-TAmla, showed significantly reduced product inhibition by aliphatic ketone. The product inhibition constants of the mutant with 2-butanone and 2-heptanone were 6- and 4.5-fold higher than those of the wild type, respectively. Using omega-TAmla (50 U/ml) overexpressed in Escherichia coli BL21, 150 mM 2-aminoheptane was successfully resolved to (R)-2-aminoheptane (enantiomeric excess, >99%) with 53% conversion with an enantioselectivity of >100.
Topics: Amines; Amino Acid Substitution; Butanones; Culture Media; Directed Molecular Evolution; Enzyme Stability; Kinetics; Substrate Specificity; Transaminases; Vibrio
PubMed: 16085806
DOI: 10.1128/AEM.71.8.4220-4224.2005 -
Journal of Food Protection Jul 2005The thiosulfate-citrate-bile salts-sucrose agar (TCBS) used in the most-probable-number method for detecting Vibrio parahaemolyticus cannot differentiate growth of V....
The thiosulfate-citrate-bile salts-sucrose agar (TCBS) used in the most-probable-number method for detecting Vibrio parahaemolyticus cannot differentiate growth of V. parahaemolyticus from Vibrio vulnificus or Vibrio mimicus. This study examined the selectivity and specificity of Bio-Chrome Vibrio medium (BCVM), a chromogenic medium that detects V. parahaemolyticus on the basis of the formation of distinct purple colonies on the medium. A panel consisting of 221 strains of bacteria, including 179 Vibrio spp. and 42 non-Vibrio spp., were examined for their ability to grow and produce colored colonies on BCVM. Growth of Salmonella, Shigella, Escherichia coli, Enterobacter cloacae, Yersinia enterocolitica, and Aeromonas was inhibited by both BCVM and TCBS. All 148 strains of V. parahaemolyticus grew on BCVM, and 145 of them produced purple colonies. The remaining 31 Vibrio spp., except one strain of Vibrio fluvialis, were either unable to grow or produced blue-green or white colonies on BCVM. Bio-Chrome Vibrio medium was capable of differentiating V. parahaemolyticus from other species, including V. vulnificus and V. mimicus. Further studies are needed to evaluate the sensitivity and specificity of BCVM for detecting V. parahaemolyticus in foods.
Topics: Chromogenic Compounds; Colony Count, Microbial; Color; Culture Media; Food Contamination; Seafood; Sensitivity and Specificity; Species Specificity; Vibrio parahaemolyticus
PubMed: 16013386
DOI: 10.4315/0362-028x-68.7.1454 -
Infection and Immunity Feb 2005In pathogenic bacteria, iron acquisition is important for colonization and proliferation in the host under iron-limited conditions. The ability of Vibrio spp. to acquire...
In pathogenic bacteria, iron acquisition is important for colonization and proliferation in the host under iron-limited conditions. The ability of Vibrio spp. to acquire iron is often critical to their virulence, causing gastroenteritis or excessive watery diarrhea in humans. In the study described here, we cloned the 2,100-bp heme utilization protein gene hupO in Vibrio fluvialis. HupO had high homology to iron-regulated outer membrane receptor proteins in Vibrio sp. and contained motifs that are common to bacterial heme receptors, including a consensus TonB box, a FRAP domain, and an NPNL domain. To characterize the hemin-binding activity of HupO, we purified the recombinant HupO protein (rHupO) from Escherichia coli by using an overexpression system. HupO was found to bind to hemin but not to hemoglobin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting demonstrated that the 77-kDa outer membrane protein HupO of V. fluvialis was induced under iron-restricted conditions. We constructed a hupO mutant, HP1, to investigate the biochemical function of HupO in V. fluvialis. The hemolytic activity of HP1 was reduced compared to that of wild-type cells and, when exposed to hydrogen peroxide, significantly lower numbers of HP1 survived than was the case in the wild type. These results suggest that HupO is associated with virulence expression in V. fluvialis through stimulation of hemolysin production and resistance to oxidative stress. In experimentally infected mice, the 50% lethal dose value of the wild-type was lower than that of the mutant, HP1.
Topics: Amino Acid Sequence; Animals; Bacterial Outer Membrane Proteins; Electrophoresis, Polyacrylamide Gel; Hemin; Hemolysis; Iron; Mice; Molecular Sequence Data; Oxidative Stress; Sequence Alignment; Sequence Homology; Vibrio; Vibrio Infections; Virulence
PubMed: 15664910
DOI: 10.1128/IAI.73.2.722-729.2005 -
Journal of Clinical Microbiology Jan 2005We describe a case of peritonitis due to Vibrio fluvialis in a patient receiving continuous ambulatory peritoneal dialysis; we believe the case to be associated with the...
We describe a case of peritonitis due to Vibrio fluvialis in a patient receiving continuous ambulatory peritoneal dialysis; we believe the case to be associated with the consumption of poorly prepared seafood. This was shown to be an important but rare cause of recurrent infection in our patient.
Topics: Female; Humans; Kidney Failure, Chronic; Middle Aged; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Vibrio; Vibrio Infections
PubMed: 15635032
DOI: 10.1128/JCM.43.1.514-515.2005 -
Journal of Food Protection Dec 2004Coliform counts in a variety of foods, including dairy products (raw milk, pasteurized milk, yogurt, butter, and ice cream), meats (pork sausage, ground beef, and raw... (Comparative Study)
Comparative Study
Coliform counts in a variety of foods, including dairy products (raw milk, pasteurized milk, yogurt, butter, and ice cream), meats (pork sausage, ground beef, and raw chicken), raw eggs, and chocolate, were performed by the rapid automated BioSys optical assay and the conventional method with violet red bile agar (VRBA). The standard deviation (SD) among five replicate counts for the optical assay was similar to or better than that obtained with VRBA plates for all foods tested. The average SD for all foods tested was 0.21 for the optical assay and 0.30 for the VRBA plates. At very low concentrations of coliforms (1 to 10 CFU/ml for liquid products and 10 to 100 CFU/g for solid samples), the average SDs were 0.26 and 0.47, respectively. The optical assay was less susceptible to interference by noncoliform organisms. In naturally contaminated samples, bacteria such as Serratia liquefaciens, Pantoea spp., Vibrio fluvialis, Aeromonas hydrophilia, and Pseudomonas spp. formed typical colonies in VRBA, resulting in false-positive results or a need to verify colonies in brilliant green lactose broth. The optical assay appeared to be more selective than the VRBA conventional method, detecting fewer noncoliforms. There was close agreement in test results between the two methods, as indicated by correlation coefficients of 0.92 to 0.99 obtained for the regression analysis of the two methods. In most cases both methods distinguished accurately between positive samples containing coliforms and negative controls. All products tested using the automated BioSys Optical Assay for coliforms yielded results more quickly (typically 10 to 12 h) than did those tested with the conventional VRBA method (24 to 72 h with confirmation).
Topics: Agar; Bacteriological Techniques; Cacao; Colony Count, Microbial; Dairy Products; Eggs; Enterobacteriaceae; Fluorescence; Food Microbiology; Regression Analysis; Sensitivity and Specificity; Time Factors
PubMed: 15633683
DOI: 10.4315/0362-028x-67.12.2760