title: Distribution and molecular characteristics of Vibrio cholerae O1 El Tor isolates recovered in Guangdong Province, China, 1961-2013.
abstract: China's Guangdong Province is located along the same latitude as Kolkata, India and Dhaka, Bangladesh, and is also considered a source of epidemic cholera. However, molecular description and the genetic relationships between Vibrio cholerae O1 El Tor isolates in Guangdong remain unclear. In this study, 381 clinical V. cholerae O1 isolates recovered from cholera cases presenting in Guangdong between 1961 and 2013 were investigated by PCR, amplicon sequencing and pulsed-field gel electrophoresis (PFGE). During this time frame, four distinct epidemic periods (1-4) were observed based on the different dominant serotype leading its epidemic, correspond to years; or time periods from/to 1961-1969, 1978-1989, 1990-2000, 2001-2013, respectively. Molecular analysis of representative isolates indicated that a single dominating clone was associated with each epidemic stage. All isolates from periods 1 and 2 carried the typical El Tor ctxB; this allele was displaced by classical ctxB beginning in 1993. However all isolates carried the El Tor-specific toxin-coregulated pili subunit A (tcpA). Isolates were grouped into five clusters on the basis of Not I enzyme digested PFGE, and the first four clusters were associated with specific periods, cluster I (period 1), II (period 3), III (period 2) and IV (period 4), respectively. While cluster V consisted of isolates from all four epidemic periods, but was most heterogeneous in appearance. Our data indicate genetic variations that shape the relationship among emerging isolates of V. cholerae O1 in Guangdong Province contribute to the 7th global pandemic.
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China; Key Laboratory for Repository and Application of Pathogenic Microbiology, Research Center for Pathogens Detection Technology of Emerging Infectious Diseases, Guangdong, Provincial Center for Disease Control and Prevention, Guangzhou 511430, China; WHO Collaborating Centre for Surveillance, Research and Training of Emerging Infectious Diseases, Guangzhou 511430, China.
authors.forename: Baisheng
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Rongfeng
authors.initials: R
authors.lastname: Chen
authors.affiliation: National Institute of Communicable Disease Control and Prevention, China CDC/State Key Laboratory for Infectious Disease Prevention and Control, Beijing 102206, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
authors.forename: Duochun
authors.initials: D
authors.lastname: Wang
authors.affiliation: Key Laboratory for Repository and Application of Pathogenic Microbiology, Research Center for Pathogens Detection Technology of Emerging Infectious Diseases, Guangdong, Provincial Center for Disease Control and Prevention, Guangzhou 511430, China; WHO Collaborating Centre for Surveillance, Research and Training of Emerging Infectious Diseases, Guangzhou 511430, China.
authors.forename: Hailing
authors.initials: H
authors.lastname: Tan
authors.affiliation: Key Laboratory for Repository and Application of Pathogenic Microbiology, Research Center for Pathogens Detection Technology of Emerging Infectious Diseases, Guangdong, Provincial Center for Disease Control and Prevention, Guangzhou 511430, China; WHO Collaborating Centre for Surveillance, Research and Training of Emerging Infectious Diseases, Guangzhou 511430, China.
authors.forename: Bixia
authors.initials: B
authors.lastname: Ke
authors.affiliation: Key Laboratory for Repository and Application of Pathogenic Microbiology, Research Center for Pathogens Detection Technology of Emerging Infectious Diseases, Guangdong, Provincial Center for Disease Control and Prevention, Guangzhou 511430, China; WHO Collaborating Centre for Surveillance, Research and Training of Emerging Infectious Diseases, Guangzhou 511430, China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: He
authors.affiliation: Key Laboratory for Repository and Application of Pathogenic Microbiology, Research Center for Pathogens Detection Technology of Emerging Infectious Diseases, Guangdong, Provincial Center for Disease Control and Prevention, Guangzhou 511430, China; WHO Collaborating Centre for Surveillance, Research and Training of Emerging Infectious Diseases, Guangzhou 511430, China.
authors.forename: Changwen
authors.initials: C
authors.lastname: Ke
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China; Key Laboratory for Repository and Application of Pathogenic Microbiology, Research Center for Pathogens Detection Technology of Emerging Infectious Diseases, Guangdong, Provincial Center for Disease Control and Prevention, Guangzhou 511430, China; WHO Collaborating Centre for Surveillance, Research and Training of Emerging Infectious Diseases, Guangzhou 511430, China. Electronic address: zyh@cdcp.org.cn.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D002681:China / Q000453:epidemiology; D002771:Cholera / Q000453:epidemiology* / Q000382:microbiology; D002772:Cholera Toxin / Q000235:genetics*; D004196:Disease Outbreaks; D019143:Evolution, Molecular; D014644:Genetic Variation; D006801:Humans; D058889:Molecular Typing / Q000379:methods; D010802:Phylogeny; D058974:Phylogeography; D041241:Vibrio cholerae O1 / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*
chemical_list: D002772:Cholera Toxin
keywords: China; Guangdong province; Molecular characteristics; O1 El Tor; Vibrio cholerae