title: The purifying trend in the chromosomal integron in Vibrio cholerae strains during the seventh pandemic.
abstract: Chromosomal integron (CI) arrays in Vibrio spp. are generally large and display great variation. Here we determined the sequence of CI array in a toxigenic O139 Vibriocholerae strain and compared it with the arrays from the genome of different O1 biotypes available in GenBank. Then PCR scanning was used to determine the CI array variations in 83 epidemic O139 strains and subsequently these variations were compared with that found in toxigenic O1 El Tor strains in our previous work. Few differences were observed in the cohort of toxigenic O139 strains compared to the toxigenic O1 El Tor strains. On the basis of CI arrays, the toxigenic O1 El Tor and O139 strains isolated concurrently in recent years appear to be more similar to each other than to the O1 strains isolated in previous decades, suggesting a closer evolutionary relationship between them. Comparison of CI arrays in toxigenic O1 El Tor and O139 V. cholerae strains isolated between 1961 and 2009 revealed a purifying trend in the CI arrays in the chronological order during the seventh pandemic.
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Department of Diarrheal Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Cuicai
authors.initials: C
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Department of Diarrheal Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Pang
authors.affiliation: The University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: Zhemin
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Department of Diarrheal Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Haiyin
authors.initials: H
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Department of Diarrheal Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Haijian
authors.initials: H
authors.lastname: Zhou
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Department of Diarrheal Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Lu
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Department of Diarrheal Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Du
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Department of Diarrheal Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Department of Diarrheal Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Department of Diarrheal Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Cui
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Department of Diarrheal Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.affiliation: The ithree Institute, University of Technology, Sydney, New South Wales, Australia.
authors.forename: H W
authors.initials: HW
authors.lastname: Stokes
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Department of Diarrheal Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China. Electronic address: kanbiao@icdc.cn.
authors.forename: Biao
authors.initials: B
authors.lastname: Kan
mesh_terms: D002771:Cholera / Q000453:epidemiology* / Q000382:microbiology; D002772:Cholera Toxin / Q000235:genetics; D002876:Chromosomes, Bacterial; D006801:Humans; D054643:INDEL Mutation; D032023:Integrons; D016366:Open Reading Frames; D010802:Phylogeny; D011938:Rec A Recombinases / Q000235:genetics; D014734:Vibrio cholerae / Q000145:classification / Q000235:genetics*
chemical_list: D002772:Cholera Toxin; D011938:Rec A Recombinases
keywords: Cholera; Chromosomal integron; Evolution; Gene cassettes; Vibrio cholerae