title: Molecular characterization of recent Vibrio cholerae O1, El Tor, Inaba strains isolated from hospitalized patients in Kolkata, India.
abstract: OBJECTIVE
  To study the phenotypic and genotypic characterization of newly emerged V. cholerae O1, Inaba strains isolated from patients with diarrhoea.
  
  
  METHODS
  Bacterial characterization was made using polymerase chain reaction, ribotyping, PFGE and RFLP.
  
  
  RESULTS
  After its first appearance in July 2004, O1 Inaba became the dominant serotype by March 2005 and totally replaced the former dominant serotype, Ogawa from May 2005. Most of the Inaba isolates belong to a new ribotype RIV. Ogawa and also some Inaba strains isolated during the same period were identified as RIII. Similarly, the majority of the Inaba isolates belong to 'H1' pulsotype and one isolate is type 'H', while the Ogawa isolates were mostly 'H' pulsotype. Presence of CTX prophage was detected in a single site of the chromosome with at least two RS elements.
  
  
  CONCLUSIONS
  There has been a switch of dominant serotype from Ogawa to Inaba in the Kolkata region. This is not necessarily due to emergence of a new clone but does serve as an epidemiological marker. Further analysis at the molecular level will be required to define this trend and to monitor future spread to other regions.
authors.affiliation: National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors.forename: Amit
authors.initials: A
authors.lastname: Raychoudhuri
authors.forename: Souvik
authors.initials: S
authors.lastname: Chatterjee
authors.forename: Gururaja P
authors.initials: GP
authors.lastname: Pazhani
authors.forename: Ranjan K
authors.initials: RK
authors.lastname: Nandy
authors.forename: Mihir K
authors.initials: MK
authors.lastname: Bhattacharya
authors.forename: Sujit K
authors.initials: SK
authors.lastname: Bhattacharya
authors.forename: T
authors.initials: T
authors.lastname: Ramamurthy
authors.forename: Asish K
authors.initials: AK
authors.lastname: Mukhopadhyay
mesh_terms: D002771:Cholera / Q000453:epidemiology / Q000382:microbiology*; D002772:Cholera Toxin / Q000235:genetics; D002876:Chromosomes, Bacterial / Q000235:genetics; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D006760:Hospitalization; D006801:Humans; D007194:India / Q000453:epidemiology; D017720:Molecular Epidemiology; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D039002:Prophages / Q000235:genetics; D021521:Ribotyping; D041241:Vibrio cholerae O1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D002772:Cholera Toxin