A molecular surveillance reveals the prevalence of Vibrio cholerae O139 isolates in China from 1993 to 2012.
Vibrio cholerae serogroup O139 was first identified in 1992 in India and Bangladesh, in association with major epidemics of cholera in both countries; cases were noted shortly thereafter in China. We characterized 211 V. cholerae O139 isolates that were isolated at multiple sites in China between 1993 and 2012 from patients (n = 92) and the environment (n = 119). Among clinical isolates, 88 (95.7%) of 92 were toxigenic, compared with 47 (39.5%) of 119 environmental isolates. Toxigenic isolates carried the El Tor CTX prophage and toxin-coregulated pilus A gene (tcpA), as well as the Vibrio seventh pandemic island I (VSP-I) and VSP-II. Among a subset of 42 toxigenic isolates screened by multilocus sequence typing (MLST), all were in the same sequence type as a clinical isolate (MO45) from the original Indian outbreak. Nontoxigenic isolates, in contrast, generally lacked VSP-I and -II, and fell within 13 additional sequence types in two clonal complexes distinct from the toxigenic isolates. In further pulsed-field gel electrophoresis (PFGE) (with NotI digestion) studies, toxigenic isolates formed 60 pulsotypes clustered in one group, while the nontoxigenic isolates formed 43 pulsotypes which clustered into 3 different groups. Our data suggest that toxigenic O139 isolates from widely divergent geographic locations, while showing some diversity, have maintained a relatively tight clonal structure across a 20-year time span. Nontoxigenic isolates, in contrast, exhibited greater diversity, with multiple clonal lineages, than did their toxigenic counterparts.
National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention/State Key Laboratory for Infectious Disease Prevention and Control, Beijing, China, and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China.
Ping
P
Zhang
Haijian
H
Zhou
Baowei
B
Diao
Fengjuan
F
Li
Pengcheng
P
Du
Jie
J
Li
Biao
B
Kan
J Glenn
JG
Morris
Duochun
D
Wang
D002681:China / Q000453:epidemiology; D002771:Cholera / Q000453:epidemiology* / Q000382:microbiology*; D002772:Cholera Toxin / Q000235:genetics / Q000378:metabolism; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D004783:Environmental Microbiology; D062665:Epidemiological Monitoring; D005798:Genes, Bacterial; D005838:Genotype; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D015995:Prevalence; D039002:Prophages / Q000235:genetics; D041242:Vibrio cholerae O139 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity
D004269:DNA, Bacterial; D002772:Cholera Toxin