title: Drug response and genetic properties of Vibrio cholerae associated with endemic cholera in north-eastern Thailand, 2003-2011.
abstract: Cholera, caused by Vibrio cholerae, results in significant morbidity and mortality worldwide, including Thailand. Representative V. cholerae strains associated with endemic cholera (n = 32), including strains (n = 3) from surface water sources, in Khon Kaen, Thailand (2003-2011), were subjected to microbiological, molecular and phylogenetic analyses. According to phenotypic and related genetic data, all tested V. cholerae strains belonged to serogroup O1, biotype El Tor (ET), Inaba (IN) or Ogawa (OG). All of the strains were sensitive to gentamicin and ciprofloxacin, while multidrug-resistant (MDR) strains showing resistance to erythromycin, tetracycline, trimethoprim/sulfamethoxazole and ampicillin were predominant in 2007. V. cholerae strains isolated before and after 2007 were non-MDR. All except six diarrhoeal strains possessed ctxA and ctxB genes and were toxigenic altered ET, confirmed by MAMA-PCR and DNA sequencing. Year-wise data revealed that V. cholerae INET strains isolated between 2003 and 2004, plus one strain isolated in 2007, lacked the RS1 sequence (rstC) and toxin-linked cryptic plasmid (TLC)-specific genetic marker, but possessed CTX(CL) prophage genes ctxB(CL) and rstR(CL). A sharp genetic transition was noted, namely the majority of V. cholerae strains in 2007 and all in 2010 and 2011 were not repressor genotype rstR(CL) but instead were rstR(ET), and all ctx(+) strains possessed RS1 and TLC-specific genetic markers. DNA sequencing data revealed that strains isolated since 2007 had a mutation in the tcpA gene at amino acid position 64 (N→S). Four clonal types, mostly of environmental origin, including subtypes, reflected genetic diversity, while distinct signatures were observed for clonally related, altered ET from Thailand, Vietnam and Bangladesh, confirmed by distinct subclustering patterns observed in the PFGE (NotI)-based dendrogram, suggesting that endemic cholera is caused by V. cholerae indigenous to Khon Kaen.
authors: Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors: Chariya
authors: C
authors: Chomvarin
authors: Center for Food and Waterborne Disease, International Center for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors: Fatema-Tuz
authors: FT
authors: Johura
authors: Center for Food and Waterborne Disease, International Center for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors: Shahnewaj B
authors: SB
authors: Mannan
authors: Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors: Warin
authors: W
authors: Jumroenjit
authors: Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
authors: Boonnapa
authors: B
authors: Kanoktippornchai
authors: Bureau of General Communicable Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand.
authors: Waraluk
authors: W
authors: Tangkanakul
authors: Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand.
authors: Napaporn
authors: N
authors: Tantisuwichwong
authors: National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Thailand.
authors: Sriwanna
authors: S
authors: Huttayananont
authors: National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan.
authors: Haruo
authors: H
authors: Watanabe
authors: Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, USA.
authors: Nur A
authors: NA
authors: Hasan
authors: Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, USA.
authors: Anwar
authors: A
authors: Huq
authors: Center for Food and Waterborne Disease, International Center for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors: Alejandro
authors: A
authors: Cravioto
authors: University of Maryland Institute for Advanced Computer Studies, College Park, MD, USA.|Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.|Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, USA.
authors: Rita R
authors: RR
authors: Colwell
authors: Center for Food and Waterborne Disease, International Center for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
authors: Munirul
authors: M
authors: Alam
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002771:Cholera / Q000453:epidemiology* / Q000382:microbiology*; D002772:Cholera Toxin / Q000235:genetics; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial; D019353:Endemic Diseases; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058889:Molecular Typing; D010957:Plasmids; D016133:Polymerase Chain Reaction; D039002:Prophages / Q000235:genetics; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013785:Thailand / Q000453:epidemiology; D014734:Vibrio cholerae / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D037521:Virulence Factors / Q000235:genetics; D014871:Water Microbiology
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D037521:Virulence Factors; D002772:Cholera Toxin