Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, China.
Foodborne Pathog Dis. 2011 Nov;8(11):1169-76. doi: 10.1089/fpd.2011.0865. Epub 2011 Sep 1.
Multilocus sequence typing (MLST) was used to examine the clonal relationship and genetic diversity of 71 Vibrio parahaemolyticus isolates from clinical and seafood-related sources in southeastern Chinese coast between 2002 and 2009. The tested isolates fell into 61 sequence types (STs). Of 17 clinical isolates, 7 belonged to ST3 of the pandemic clonal complex 3, with 3 strains isolated in 2002. Although there was no apparent clonal relationship found between clinical strains and those from seafood-related sources positive with pathogenic markers, there were clonal relationships between clinical strains from this study and those from environmental sources in other parts of China. Phylogenetic analysis showed that strains of 112 STs (61 STs from this study and 51 retrieved from PUBMLST database covering different continents) could be divided into four branches. The vast majority of our isolates and those from other countries were genetically diverse and clustered into two major branches of mixed distribution (of geographic origins and sample sources), whereas five STs representing six isolates split as two minor branches because of divergence of their recA genes, which had 80%-82% nucleotide identity to typical V. parahaemolyticus strains and 73.3%-76.9% identity to the CDS24 of a Vibrio sp. plasmid p23023, indicating that the recA gene might have recombined by lateral gene transfer. This was further supported by a high ratio of recombination to mutation (3.038) for recA. In conclusion, MLST with fully extractable database is a powerful system for analysis of clonal relationship for strains of a particular region in a national or global scale as well as between clinical and environmental or food-related strains.
多基因序列分型（MLST）用于检测 2002 年至 2009 年间中国东南沿海临床和海鲜相关来源的 71 株副溶血性弧菌的克隆关系和遗传多样性。 测试的分离株分为 61 种序列型（ST）。 在 17 株临床分离株中，有 7 株属于流行克隆复合体 3 的 ST3，其中 3 株于 2002 年分离。 尽管临床分离株与具有致病性标记的海鲜相关来源的分离株之间没有明显的克隆关系，但本研究的临床分离株与中国其他地区环境来源的分离株之间存在克隆关系。 系统发育分析表明，112 个 ST 株（本研究中的 61 个 ST 和从 PUBMLST 数据库中检索到的 51 个涵盖不同大陆的 ST）可分为四个分支。 我们的绝大多数分离株和来自其他国家的分离株具有遗传多样性，并聚类为两个主要分支，分布广泛（地理位置和样本来源混合），而代表六个分离株的五个 ST 由于 recA 基因的分歧而分裂成两个小分支，其 recA 基因与典型副溶血性弧菌菌株的核苷酸同一性为 80％-82％，与 Vibrio sp. 的 CDS24 同一性为 73.3％-76.9％质粒 p23023，表明 recA 基因可能通过水平基因转移发生了重组。 这进一步得到了 recA 的重组与突变比（3.038）高的支持。 总之，具有完全可提取数据库的 MLST 是分析特定地区（国家或全球范围内）以及临床和环境或食品相关菌株之间的克隆关系的强大系统。
