title: Genomic study of the Type IVC secretion system in Clostridium difficile: understanding C. difficile evolution via horizontal gene transfer.
abstract: Clostridium difficile, the etiological agent of Clostridium difficile infection (CDI), is a gram-positive, spore-forming bacillus that is responsible for ∼20% of antibiotic-related cases of diarrhea and nearly all cases of pseudomembranous colitis. Previous data have shown that a substantial proportion (11%) of the C. difficile genome consists of mobile genetic elements, including seven conjugative transposons. However, the mechanism underlying the formation of a mosaic genome in C. difficile is unknown. The type-IV secretion system (T4SS) is the only secretion system known to transfer DNA segments among bacteria. We searched genome databases to identify a candidate T4SS in C. difficile that could transfer DNA among different C. difficile strains. All T4SS gene clusters in C. difficile are located within genomic islands (GIs), which have variable lengths and structures and are all conjugative transposons. During the horizontal-transfer process of T4SS GIs within the C. difficile population, the excision sites were altered, resulting in different short-tandem repeat sequences among the T4SS GIs, as well as different chromosomal insertion sites and additional regions in the GIs.
authors.affiliation: a State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.|b Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: c Key Laboratory of Surveillance and Early-warning on Infectious Disease, Division of Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: a State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.|e Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China.|f Beijing Key Laboratory of Emerging Infectious Diseases, Beijing 100011, China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Du
authors.affiliation: a State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.|e Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China.|f Beijing Key Laboratory of Emerging Infectious Diseases, Beijing 100011, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: d Department of clinical laboratory, China-Japan Friendship Hospital, Beijing 100029, China.
authors.forename: Hongbing
authors.initials: H
authors.lastname: Jia
authors.affiliation: a State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.|b Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
authors.forename: Xianping
authors.initials: X
authors.lastname: Li
authors.affiliation: a State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.|b Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: a State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.|b Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
authors.forename: Na
authors.initials: N
authors.lastname: Han
authors.affiliation: a State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.|b Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
authors.forename: Yujun
authors.initials: Y
authors.lastname: Qiang
authors.affiliation: a State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.|e Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China.|f Beijing Key Laboratory of Emerging Infectious Diseases, Beijing 100011, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.affiliation: a State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.|b Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China.
authors.forename: Jinxing
authors.initials: J
authors.lastname: Lu
mesh_terms: D005075:Biological Evolution; D016360:Clostridioides difficile / Q000502:physiology*; D022761:Gene Transfer, Horizontal; D016680:Genome, Bacterial; D044404:Genomic Islands; D023281:Genomics / Q000379:methods; D059014:High-Throughput Nucleotide Sequencing; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D000069319:Type IV Secretion Systems / Q000235:genetics
chemical_list: D000069319:Type IV Secretion Systems
keywords: Clostridium difficile; bacteria; bactéries; genome; genomic island; génome; système de sécrétion de type IVC; type IVC secretion system; îlot génomique