title: Diversity of Vibrio cholerae strains isolated in Delhi, India, during 1992-2000.
abstract: The National Institute of Communicable Diseases (NICD), Delhi, India, conducts a laboratory-based surveillance of cholera cases referred from the Infectious Disease Hospital, Delhi. The prevalence and antimicrobial susceptibilities of Vibrio cholerae O1, O139, and others, isolated from cholera patients for nine years, were analyzed to determine the changing trends in their isolation and drug-resistance patterns. In total, 29,196 stool samples or rectal swabs, collected during April 1992-December 2000, were included in this study. Of these, 13,730 (47%) were positive for V. cholerae: 11,091 for V. cholerae O1 (80.7%) and 1,943 (14%) for V. cholerae O139, and 696 (5%) were non-O1 and non-O139. V. cholerae O1 was the dominant serotype during 1992-1993, when V. cholerae O139 emerged as a new serotype but, thereafter, remained low from 1994 to 1999. Phenotypically, re-emerged V. cholerae O139 in 2000 displayed a difference compared to those that appeared in 1992-1993, in that the current O139 strains were sensitive to co-trimoxazole. Resistance to nalidixic acid and furazolidone was constantly high (100%) among strains of V. cholerae O1 and O139. All strains of V. cholerae were uniformly susceptible to chloramphenicol, tetracycline, amikacin, and norfloxacin. Molecular studies revealed different clones of V. cholerae O1 and O139 prevailing in the country with the re-emergence of V. cholerae O139 of a different clonality in Delhi in 2000, which is likely to play a critical role in temporal antigenic variation among the serogroups of V. cholerae.
authors.affiliation: National Institute of Communicable Diseases, 22 Sham Nath Marg, Delhi 110 054, India. shukladas_123@yahoo.com
authors.forename: Shukla
authors.initials: S
authors.lastname: Das
authors.forename: Sunil
authors.initials: S
authors.lastname: Gupta
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001434:Bacteriophage Typing; D002771:Cholera / Q000188:drug therapy* / Q000453:epidemiology* / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005243:Feces / Q000382:microbiology; D014644:Genetic Variation; D006801:Humans; D007194:India / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D012621:Seasons; D012703:Serotyping; D014734:Vibrio cholerae / Q000145:classification* / Q000187:drug effects* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents