Molecular characterization of Streptococcus agalactiae isolated from bovine mastitis in Eastern China.
Molecular characterization of Streptococcus agalactiae isolated from bovine mastitis in Eastern China.
复制标题
从中国东部牛乳腺炎中分离出的无乳链球菌的分子特征
DOI：
10.1371/journal.pone.0067755
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Lu C
中科院分区：
文献类型：
--
作者：
Yang Y;Liu Y;Ding Y;Yi L;Ma Z;Fan H;Lu C
2011年从中国东部奶牛隐性乳房炎中分离到102株无乳链球菌（B群链球菌[GBS]）。分别采用多位点序列分型（MLST）和脉冲场凝胶电泳（PFGE）建立克隆群。荚膜多糖（CPS），菌毛和α-样蛋白（Alp）家族基因的分子技术进行了表征。MLST分析表明，这些分离物仅限于3个克隆群，并聚在6个不同的谱系中，即ST（序列型）103、ST 568、ST 67、ST 301、ST 313和ST 570，其中ST 568和ST 570为新的基因型。PFGE分析表明，该菌株可分为27个PFGE型，其中7、8、14、15、16、18、23和25型为主要的8个PFGE型，占总菌株数的70%（71/102）。最流行的序列类型是ST 103（58%分离株）和ST 568（31%分离株），包括荚膜基因型Ia分离株，没有任何检测到的Alp基因，表明牛链球菌流行株的新基因组背景的出现。无乳。所有菌株均携带菌毛岛2b（PI-2b）基因，其菌毛类型以Ia型（89%）和II型（11%）为主，这为乳腺炎疫苗的研制提供了依据。无乳。
One hundred and two Streptococcus agalactiae (group B streptococcus [GBS]) isolates were collected from dairy cattle with subclinical mastitis in Eastern China during 2011. Clonal groups were established by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE), respectively. Capsular polysaccharides (CPS), pilus and alpha-like-protein (Alp) family genes were also characterized by molecular techniques. MLST analysis revealed that these isolates were limited to three clonal groups and were clustered in six different lineages, i.e. ST (sequence type) 103, ST568, ST67, ST301, ST313 and ST570, of which ST568 and ST570 were new genotypes. PFGE analysis revealed this isolates were clustered in 27 PFGE types, of which, types 7, 8, 14, 15, 16, 18, 23 and 25 were the eight major types, comprising close to 70% (71/102) of all the isolates. The most prevalent sequence types were ST103 (58% isolates) and ST568 (31% isolates), comprising capsular genotype Ia isolates without any of the detected Alp genes, suggesting the appearance of novel genomic backgrounds of prevalent strains of bovine S. agalactiae. All the strains possessed the pilus island 2b (PI-2b) gene and the prevalent capsular genotypes were types Ia (89% isolates) and II (11% isolates), the conserved pilus type providing suitable data for the development of vaccines against mastitis caused by S. agalactiae.