Table 1.

Analysis of genes for rRNA, CT (ctxA), and the SXT element in clinical strains of toxigenic V. choleraeO139 isolated between 1995 and 1998a

Yr of isolationPlace of isolationNo. of isolatesrRNA gene restriction patternctxA genotypeSXT genotypeAntimicrobial resistance patternb
1995Matlab, Bangladesh5IA1SrSXTr
1995Matlab, Bangladesh6IIA1Sr SXTr
1997Matlab, Bangladesh5IIB2Susceptible
1996Jhalokati, Bangladesh2IIB2Susceptible
1995Dhaka, Bangladesh5IIA1SrSXTr
1996Dhaka, Bangladesh7IIB2Susceptible
1996Sunamganj, Bangladesh2IIB1Sr SXTr
1997Bakerganj, Bangladesh1IIB2Susceptible
1998Bakerganj, Bangladesh6IIB2Susceptible
1997Mymensingh, Bangladesh8IIIB2Susceptible
1997Kishoreganj, Bangladesh11IIIB2Susceptible
1997Bangkok, Thailand3IIB1Sr SXTr
1997Calcutta, India6IIA2Susceptible
  • a All strains were negative in PCR assays for chromosomal regions representing rfbDEG,rfbNO, ompX, orf2, and orf3of the rfb gene cluster of V. cholerae O1. Ribotypes, ctxA genotypes, and SXT genotypes are based onBglI restriction patterns of the respective genes and their flanking chromosomal sequences.

  • b Strains designated “Susceptible” were susceptible to tetracycline, ampicillin, chloramphenicol, gentamicin, ciprofloxacin, norfloxacin, nalidixic acid, streptomycin, and SXT. Sr, streptomycin resistant; SXTr, SXT resistant.