title: Multilocus sequence typing and virulence analysis of Haemophilus parasuis strains isolated in five provinces of China.
abstract: Haemophilus parasuis is the etiological agent of Glässers disease, which causes high morbidity and mortality in swine herds. Although H. parasuis strains can be classified into 15 serovars with the Kielstein-Rapp-Gabrielson serotyping scheme, a large number of isolates cannot be classified and have been designated 'nontypeable' strains. In this study, multilocus sequence typing (MLST) of H. parasuis was used to analyze 48 H. parasuis field strains isolated in China and two strains from Australia. Twenty-six new alleles and 29 new sequence types (STs) were detected, enriching the H. parasuis MLST databases. A BURST analysis indicated that H. parasuis lacks stable population structure and is highly heterogeneous, and that there is no association between STs and geographic area. When an UPGMA dendrogram was constructed, two major clades, clade A and clade B, were defined. Animal experiments, in which guinea pigs were challenged intraperitoneally with the bacterial isolates, supported the hypothesis that the H. parasuis STs in clade A are generally avirulent or weakly virulent, whereas the STs in clade B tend to be virulent.
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, Gansu, PR China.
authors.forename: Liyan
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, Gansu, PR China.
authors.forename: Lina
authors.initials: L
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, Gansu, PR China.
authors.forename: Yongan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, Gansu, PR China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, Gansu, PR China.
authors.forename: Youquan
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, Gansu, PR China. Electronic address: lixuerui@caas.cn.
authors.forename: Xuerui
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, Gansu, PR China. Electronic address: liuyongsheng@caas.cn.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000818:Animals; D001315:Australia; D015373:Bacterial Typing Techniques; D002681:China; D005260:Female; D005787:Gene Frequency; D006168:Guinea Pigs; D006192:Haemophilus Infections / Q000382:microbiology / Q000662:veterinary; D044137:Haemophilus parasuis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D012703:Serotyping; D013552:Swine / Q000382:microbiology; D014774:Virulence
keywords: Animal experiment; Haemophilus parasuis; Multilocus sequence typing; UPGMA