Virulence and Multidrug Resistance Patterns of Vibrio cholerae O1 Isolates from Diarrheal Outbreaks of South India During 2006–2009

A total of 31 Vibrio cholerae O1 (4- Inaba and 27- Ogawa serotype) isolates collected during a three-year period (2006–2009) from acute diarrheal cases in Tamil Nadu, India were analyzed for antibiotic resistance profiling, virulence-associated factors, genetic profiling by enterobacterial repetitive intergenic consensus sequence polymerase chain reaction (ERIC PCR), and biofilm-forming ability. Antibiotic resistance profile revealed that most of the strains have become multidrug-resistant strains. All the isolates are resistant to ampicillin and polymyxin B, 97% of the isolates are resistant to nalidixic acid, 90% to co-trimoxazole, 32.3% to norfloxacin and ciprofloxacin, 29% to doxycycline, 10% to gentamicin, whereas only 3% to chloramphenicol. Molecular characterization of virulence-associated genes by multiplex PCR revealed the presence of ace, ctxA, tcpA, toxR, and ompU as 93.5%, followed by ompW with 33.3%. The presence of zot was restricted to only one isolate and hlyA was not encountered in any of...