title: Genomic profile of antibiotic resistant, classicalctxBpositiveVibrio choleraeO1 biotype El Tor isolated in 2003 and 2005 from Puri, India: A retrospective study.
abstract: OBJECTIVE
  To examine eight strains of Vibrio cholerae O1 isolated in 2003 and 2005 from Puri, India, for antibiotic susceptibility, presence of virulence and regulatory genes, cholera toxin (CT) production, CTX arrangement and genomic profiles.
  
  
  METHODS
  Bacterial strains were tested for antibiotic susceptibility using disc diffusion assay. Polymerase chain reaction determined the presence of antibiotic resistance, virulence and regulatory genes. To determine the type of cholera toxin subunit B (ctxB), nucleotide sequencing was performed. Southern hybridisation determined the number and arrangement of CTXΦ. Ribotyping and pulsed-field gel electrophoresis (PFGE) were used to determine the genomic profile of isolates.
  
  
  RESULTS
  All the eight strains, except one strain, showed resistant to nalidixic acid, sulphamethoxazole, streptomycin and trimethoprim and possessed the sullI, strB, dfrA1 and int SXT genes. All the strains carried the toxin-co-regulated pilus pathogenicity island, the CTX genetic element, the repeat in toxin and produced CT. Restriction fragment length polymorphism (RFLP) analysis showed that V. cholerae O1 possess a single copy of the CTX element flanked by tandemly arranged RS element. Nucleotide sequencing of the ctxB gene showed the presence of classical ctxB. RFLP analysis of conserved rRNA gene showed two ribotype patterns. PFGE analysis also showed at least three PFGE patterns, irrespective of year of isolations, indicating the genomic relatedness among them.
  
  
  CONCLUSIONS
  Overall, these data suggest that classical ctxB-positive V. cholerae O1 El Tor strains that appeared in 2003 continue to cause infection in 2005 in Puri, India, and belong to identical ribotype(s) and/or pulsotype(s). There is need to continuous monitor the emergence of variant of El Tor because it will improve our understanding of the evolution of new clones of variant of V. cholerae.
authors.affiliation: Department of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, Odisha, India.
authors.forename: T
authors.initials: T
authors.lastname: Bhotra
authors.affiliation: Department of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, Odisha, India.
authors.forename: M M
authors.initials: MM
authors.lastname: Das
authors.affiliation: Department of Infectious Disease Biology, Regional Medical Research Centre, Bhubaneswar, Odisha, India.
authors.forename: B B
authors.initials: BB
authors.lastname: Pal
authors.affiliation: Department of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, Odisha, India.
authors.forename: D V
authors.initials: DV
authors.lastname: Singh
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001435:Bacteriophages / Q000235:genetics; D015139:Blotting, Southern; D002771:Cholera / Q000382:microbiology*; D002772:Cholera Toxin / Q000235:genetics*; D052978:Disk Diffusion Antimicrobial Tests; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007194:India; D017720:Molecular Epidemiology; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D021521:Ribotyping; D017422:Sequence Analysis, DNA; D041241:Vibrio cholerae O1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D037521:Virulence Factors; D002772:Cholera Toxin