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Rita R. Colwell - One of the best experts on this subject based on the ideXlab platform.
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Vibrio Cholerae O1 detection in estuarine and coastal zooplankton
Journal of Plankton Research, 2010Co-Authors: José Eduardo Martinelli Filho, Rubens M. Lopes, Irma N. G. Rivera, Rita R. ColwellAbstract:Vibrio Cholerae is an autochthonous marine bacterium, and its association withdiverse planktonic crustaceans has been extensively investigated; however, the pres-ence of V. Cholerae on individuals of most phyla of planktonic animals is still incom-pletely understood. The objective of this study was to analyze the distribution ofV. Cholerae serogroup O1 associated with specific zooplankton taxa in an estuaryand the adjacent continental shelf of the southeastern Brazilian coast. The occur-rence of the bacterium was assessed in zooplankton samples, specifically on themost abundant taxa, using direct fluorescence assay (DFA) and direct viablecount–direct fluorescence assay (DVC–DFA) methods. Vibrio Cholerae O1 wasdetected in 88% of samples collected from the Santos-Bertioga estuary and in67% of samples from the shelf. The salinity of the estuarine water ranged from21.8 to 34.6, significantly lower than the shelf water which was 32.1–36.1.Salinity was the only environmental variable measured that displayed a significantcorrelation with the presence of V. Cholerae (P , 0.05). Vibrio Cholerae O1 was detectedin chaetognaths, pluteus larvae of echinoderms and planktonic fish eggs(Engraulidae), all new sites for this bacterium.KEYWORDS: plankton; estuary; DFA; Southwest Atlantic
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Covariability of Vibrio Cholerae Microdiversity and Environmental Parameters
Applied and Environmental Microbiology, 2008Co-Authors: Young-gun Zo, Eiji Arakawa, Nipa Chokesajjawatee, Haruo Watanabe, Rita R. ColwellAbstract:Fine-scale diversity of natural bacterial assemblages has been attributed to neutral radiation because correspondence between bacterial phylogenetic signals in the natural environment and environmental parameters had not been detected. Evidence that such correspondence occurs is provided for Vibrio Cholerae, establishing a critical role for environmental parameters in bacterial diversity.
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Viability of the Nonculturable Vibrio Cholerae O1 and O139
Systematic and Applied Microbiology, 2004Co-Authors: Anwarul Huq, Sitthipan Chaiyanan, Timothy K. Maugel, Rita R. ColwellAbstract:Vibrio Cholerae is capable of transforming into a viable but nonculturable (VBNC) state, and, in doing so, undergoes alteration in cell morphology. In the study reported here, Vibrio Cholerae O1 and O139 cells were maintained in laboratory microcosms prepared with 1% Instant Ocean and incubated at 4 degrees C, i.e., conditions which induce the VBNC state. Cells were fixed at different stages during entry into the VBNC state and, when no growth was detectable on solid or in liquid media, the ultrastructure of these cells was examined, using both transmission and scanning electron microscopy. As shown in earlier studies, the cells became smaller in size and changed from rod to ovoid or coccoid morphology, with the central region of the cells becoming compressed and surrounded by denser cytoplasm. Because the coccoid morphology, indicative of the VBNC state is common for Vibrio Cholerae in the natural environment, as well as in starved cells (Baker et al., 1983; Hood et al., 1986) viability of the coccoid, viable but nonculturable cell was investigated. The percentage of coccoid (VBNC) cells showing metabolic activity and retention of membrane integrity was monitored using direct fluorescence staining (LIVE/DEAD BacLight Bacterial Viability kit), with 75 to 90% of the viable but nonculturable coccoid cells found to be metabolically active by this test. Furthermore, the proportion of actively respiring cells, using the redox dye, 5-cyano-2, 3-ditolyl tetrazolium chloride (CTC), relative to total cells, the latter determined by DAPI staining, ranged from 10 to 50%. VBNC coccoid cells retained the antigenic determinants of Vibrio Cholerae O1 and O139, respectively, evidenced by positive reaction with monoclonal fluorescent antibody. Viability was further established by susceptibility of the VBNC cells to chlorine, copper sulfate, zinc sulfate, and formaldehyde. Since retention of cell membrane integrity is a determining characteristic of viable cells, DNA was extracted from VBNC cells in microcosms maintained for two months and for one year. Conservation of cholera toxin and toxin-associated genes, ctxA, toxR, tcpA, and zot in chromosomal DNA of VBNC cells was demonstrated using PCR and employing specific primers. It is concluded that not only do VBNC V Cholerae O1 and O139 retain viability up to one year, but genes associated with pathogenicity are retained, along with chromosomal integrity.
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Serogroup conversion of Vibrio Cholerae non-O1 to Vibrio Cholerae O1: effect of growth state of cells, temperature, and salinity.
Canadian Journal of Microbiology, 1996Co-Authors: Rafael Montilla, Anwarul Huq, M. A. R. Chowdhury, Rita R. ColwellAbstract:Recently, we reported the occurrence of seroconversion from Vibrio Cholerae non-O1 to V. Cholerae O1, but little is known about the environmental and physiological factors influencing seroconversion. We investigated effects of temperature (4, 25, and 35 °C) and salinity (
Ørjan Olsvik - One of the best experts on this subject based on the ideXlab platform.
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A transferable multiple drug resistance plasmid from Vibrio Cholerae O1.
Microbial Drug Resistance, 1995Co-Authors: Hilde Kruse, Henning Sørum, Fred C. Tenover, Ørjan OlsvikAbstract:ABSTRACT Ten multiple antimicrobial-resistant isolates of Vibrio Cholerae O1 isolated from patients in Uganda were characterized, and the transferability of resistance to bacteria of diverse origin...
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Vibrio Cholerae and cholera molecular to global perspectives
1994Co-Authors: Kaye Wachsmuth, Paul A Blake, Ørjan OlsvikAbstract:Introduction The bacterium Vibrio Cholerae, Isolation and identification of toxigenic Vibrio Cholerae 01 from fecal specimens Toxigenic Vibrio Cholerae in food and water Detection of cholera toxin genes Detection of toxins of Vibrio Cholerae 01 and non-01 Non-toxigenic Vibrio Cholerae 01 infections in the United States Molecular basis for O-antigen biosynthesis in Vibrio Cholerae 01 Ogawa-Inaba switching Non-O group 1 Vibrio Cholerae Vibrios in the environment Serologic diagnosis of Vibrio Cholerae 01 infection Virulence factors Toxins of Vibrio Cholerae 01 Regulation of toxin (CT) expressions The toxin-coregulated pilus: biogenesis and function Animal models in cholera research Cholera: the disease Cholera: pathophysiology Immunity to Vibrio Cholerae infection Host susceptibility Epidemiology and surveillance Cholera before 1970 The African epidemic 1970-92 Endemic cholera in Australia and the United States The Latin American epidemic Transmission of cholera Molecular epidemiology of Vibrio Cholerae 01 Cholera surveillance Vaccines Polysaccharide-protein conjugate vaccines for prevention of cholera Molecular recombinant cholera vaccines Protective oral cholera vaccine based on a combination of cholera toxin B subunit and inactivated Cholera Vibrios Public health consideration for the use of cholera vaccines in cholera control programs Cholera: the future Cholera: unanswered questions
Zheng Jian - One of the best experts on this subject based on the ideXlab platform.
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Preparation and characterization of monoclonal antibodies against Vibrio Cholerae O1 serotype Ogawa
Immunological Journal, 2006Co-Authors: Zheng JianAbstract:Objective To prepare monoclonal antibodies (McAbs) against Vibrio Cholerae O1 serotype Ogawa. Methods Balb/c mice were immunized with attenuated Vibrio Cholerae O1 serotype Ogawa. Hybridoma cell lines secreting McAbs against Vibrio Cholerae O1 serotype Ogawa were established after cell fusion with mouse splenocytes and SP2/0. The specificity and crossreactivity of McAb was identified by indirect enzyme-linked immunosorbent assay (ELISA) and Western blotting. The binding site and capability of McAb were observed by additive ELISA. Results Total of 602 McAb-positive hybridoma cell strains lines were produced and 5 of them shown high specificity for Vibrio cho- lerae O1 serotype Ogawa. The immunoglobulin subclass of the McAb were IgG_1 (3), IgG_ 2b (1), and IgG_3 (1), respectively. Indirect ELISA and Western blotting showed that the McAbs could react with Vibrio Cholerae O1 serotype Ogawa specifically. Additive ELISA indicated that only two antibodies recognized the same epitopes, while others recognized different epitopes. Conclusion Five specific McAb against Vibrio cho- lerae O1 serotype Ogawa are obtained successfully, which may be very helpful for further researches on the pathogenesis and early diagnosis of Vibrio Cholerae O1 serotype Ogawa.
Rumina Hasan - One of the best experts on this subject based on the ideXlab platform.
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Re-emergence of Vibrio Cholerae O139 in Pakistan: report from a tertiary care hospital.
JPMA. The Journal of the Pakistan Medical Association, 2003Co-Authors: Kauser Jabeen, Rumina HasanAbstract:OBJECTIVE This study reports re-emergence of Vibrio Cholerae O139 in Pakistan in 2000-2001 from a tertiary care hospital in Karachi, Pakistan. METHODS This descriptive study was conducted from 2000-2001. Stool samples were taken from inpatients or those referred to the laboratory from other hospitals, clinics and general practitioners. Samples were processed and Vibrio Cholerae isolates were identified according to standard protocols. Tellurite Taurocholate Gelatin agar was used as a selective medium for Vibrio Cholerae. Serogroups were identified by slide agglutination with polyvalent antisera. Antimicrobial sensitivities were performed by Kirby Bauer technique. Data was entered and analyzed using SPSS, p values were calculated using t test and two independent samples test. RESULTS During the study period, 144 samples were found to be infected with Vibrio Cholerae O139 in comparison with 545 Vibrio Cholerae O1. Infection with O139 was characteristically observed in the older population (mean age = 40 years) in contrast with Vibrio Cholerae O1 strains (mean age = 23 years) (p. value =
Jingwei Zhang - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous detection of Vibrio Cholerae O1 and O139 by real-time quantitative PCR
Journal of hygiene research, 2010Co-Authors: Yiying Qin, Xinglong Xiao, Jingwei ZhangAbstract:OBJECTIVE Targeting the specific O-antigen gene cluster, a Taq-Man real-time fluorescence PCR assay was developed to detect 01 and O139 Vibrio cholera concurrently and avoid frequently occurred false positives. METHODS Two pairs of specific primers and two Taq-Man fluorescent probes respectively targeting rfbM gene of Vibrio Cholerae O1 and wbfR of 0139 were designed. After optimization of conditions, the specialty and sensitivity of the detection method were evaluated and ten simulated food samples and 128 clinical samples were tested. RESULTS The detection limits of Vibrio Cholerae O1 and O139 were 92 CFU/ml and 116 CFU/ml, which were almost the same with the usual PCR method. The developed real-time fluorescence PCR protocol detected only Vibrio Cholerae O1 and O139 and it was not affected by many normal food pathogens such as Staphylococcus aureus and Salmonella, especially Vibrio Cholerae O141 which contained TCP genes and Vibrio mimicus which contained ZOT gene. The clinical detect results of the developed assay and routine culture method were exactly the same. CONCLUSION The developed detection assay could quantitatively detect Vibrio Cholerae O1 and O139 concurrently in only 3 hours, and could avoid false positive, and thus was an efficacious method for detecting Vibrio Cholerae O1 and O139 and could be used in a wide area such as entry-exit inspection and quarantine, food safety detection and clinical diagnose.
