Phenotypic and molecular characteristics of drug resistant S. Typhi (n = 18) isolates from Kolkata during 2009–2013.

Abbreviations used: MDR, multidrug resistant; ND, not done; A, ampicillin; C, chloramphenicol; Q, co-trimoxazole; T, tetracycline; S, streptomycin; Na, nalidixic acid; Ci, ciprofloxacin; Of, ofloxacin; Le, levofloxacin; Ac, amoxicillin/clavulanic acid.aall isolates were negative for blaOXA, blaSHV and sul3 genes by PCR.bpossessed dfrA7 gene cassette as determined by sequencing of 750 bp PCR amplicon.cplasmid type: IncN; tetA was positive, but tetB was negative by PCR; transfer of tetA, sul1, dfrA15 and aadA1 genes by conjugation.dgene cassette could not be determined by sequencing of 1.6 kb PCR amplicon.