title: Streptococcus suis sequence type 7 outbreak, Sichuan, China.
abstract: An outbreak of Streptococcus suis serotype 2 emerged in the summer of 2005 in Sichuan Province, and sporadic infections occurred in 4 additional provinces of China. In total, 99 S. suis strains were isolated and analyzed in this study: 88 isolates from human patients and 11 from diseased pigs. We defined 98 of 99 isolates as pulse type I by using pulsed-field gel electrophoresis analysis of SmaI-digested chromosomal DNA. Furthermore, multilocus sequence typing classified 97 of 98 members of the pulse type I in the same sequence type (ST), ST-7. Isolates of ST-7 were more toxic to peripheral blood mononuclear cells than ST-1 strains. S. suis ST-7, the causative agent, was a single-locus variant of ST-1 with increased virulence. These findings strongly suggest that ST-7 is an emerging, highly virulent S. suis clone that caused the largest S. suis outbreak ever described.
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Changping, Beijing 102206, People's Republic of China.
authors.forename: Changyun
authors.initials: C
authors.lastname: Ye
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Zhu
authors.forename: Huaiqi
authors.initials: H
authors.lastname: Jing
authors.forename: Huamao
authors.initials: H
authors.lastname: Du
authors.forename: Mariela
authors.initials: M
authors.lastname: Segura
authors.forename: Han
authors.initials: H
authors.lastname: Zheng
authors.forename: Biao
authors.initials: B
authors.lastname: Kan
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.forename: Xuemei
authors.initials: X
authors.lastname: Bai
authors.forename: Yongyun
authors.initials: Y
authors.lastname: Zhou
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Cui
authors.forename: Shouying
authors.initials: S
authors.lastname: Zhang
authors.forename: Dong
authors.initials: D
authors.lastname: Jin
authors.forename: Na
authors.initials: N
authors.lastname: Sun
authors.forename: Xia
authors.initials: X
authors.lastname: Luo
authors.forename: Ji
authors.initials: J
authors.lastname: Zhang
authors.forename: Zhaolong
authors.initials: Z
authors.lastname: Gong
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Sun
authors.forename: Zhenjun
authors.initials: Z
authors.lastname: Li
authors.forename: Qiangzheng
authors.initials: Q
authors.lastname: Sun
authors.forename: Honglu
authors.initials: H
authors.lastname: Liu
authors.forename: Boqing
authors.initials: B
authors.lastname: Dong
authors.forename: Changwen
authors.initials: C
authors.lastname: Ke
authors.forename: Hui
authors.initials: H
authors.lastname: Yuan
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Kecheng
authors.initials: K
authors.lastname: Tian
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
authors.forename: Jianguo
authors.initials: J
authors.lastname: Xu
mesh_terms: D000818:Animals; D002681:China / Q000453:epidemiology; D004269:DNA, Bacterial / Q000032:analysis; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D017011:Streptococcus suis / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D013552:Swine / Q000382:microbiology; D013553:Swine Diseases / Q000453:epidemiology* / Q000382:microbiology; D014774:Virulence
chemical_list: D004269:DNA, Bacterial