title: Emergence of classical ctxB genotype 1 and tetracycline resistant strains of Vibrio cholerae O1 El Tor in Assam, India.
abstract: Cholera epidemics with moderately high case fatality rates in Assam, northeast India were investigated in 2007, 2008 and 2010. Based on mismatch amplification mutation assay PCR for detection of ctxB allele, 40 isolates of Vibrio cholerae O1 El Tor collected from the epidemics were found to harbour the classical ctxB gene allele of cholera toxin (CT). DNA sequencing of ctxB gene confirmed the isolates to be genotype 1 of ctxB. Antimicrobial susceptibility tests reveal that 100% of the isolates were resistant to trimethoprim and 40% were resistant to tetracycline. The recent V. cholerae O1 strains circulating in Assam, India are due to the El Tor variant carrying classical type CT. Emergence of tetracycline and trimethoprim resistant strains necessitates the review of antibiotic use for severe cholera.
authors.affiliation: Regional Medical Research Centre for NE Region (Indian Council of Medical Research), PO Box-105, Dibrugarh-786001, Assam, India. biswaborkakoty@rediffmail.com
authors.forename: Biswajyoti
authors.initials: B
authors.lastname: Borkakoty
authors.forename: Dipankar
authors.initials: D
authors.lastname: Biswas
authors.forename: Utpala
authors.initials: U
authors.lastname: Devi
authors.forename: Kausal
authors.initials: K
authors.lastname: Yadav
authors.forename: Jagadish
authors.initials: J
authors.lastname: Mahanta
mesh_terms: D002771:Cholera / Q000188:drug therapy / Q000453:epidemiology / Q000235:genetics*; D002772:Cholera Toxin / Q000235:genetics* / Q000276:immunology; D004269:DNA, Bacterial / Q000302:isolation & purification; D005260:Female; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D008297:Male; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D016133:Polymerase Chain Reaction; D013753:Tetracycline Resistance / Q000235:genetics* / Q000276:immunology; D014296:Trimethoprim Resistance / Q000235:genetics* / Q000276:immunology; D041241:Vibrio cholerae O1 / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity
chemical_list: D004269:DNA, Bacterial; D002772:Cholera Toxin