我国施万菌分布及其分子特征分析

目的 探索中国施万菌的种群分布、分子流行病学特征及遗传进化关系，为施万菌的流行病学监测和进化研究提供依据。方法 利用基质辅助激光解吸电离–飞行时间质谱（MALDI-TOF MS）联合gyrB基因测序进行施万菌种水平鉴定；利用7个管家基因（16S rRNA、gyrA、gyrB、infB、recN、rpoA和topA）进行多位点序列分型（MLST），利用BioNumerics 7.1软件对各个序列类型（ST）构建最小生成树。结果 本研究共收集全国201株施万菌，鉴定到10个不同的菌种，其中海藻施万菌所占数量最多。不同分离来源中的施万菌种分布有所差异，临床和食品来源的施万菌种分布相似。MLST将施万菌实验室分离株划分成136个ST型和15个克隆复合体（CCs），其中CC12为海藻施万菌优势克隆群。结论 我国分布的施万菌病原谱丰富多样，提示这些菌株具有高度的遗传多样性。

Distribution and molecular characterization of Shewanella in China

  Objective  To explore the distribution and molecular epidemiological characteristics genetic evolution of Shewanella in China and provide evidence for epidemiological surveillance and evolution research of Shewanella.   Methods  The identification of Shewanella species was performed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) combined with gyrB gene sequencing. Multilocus sequence typing (MLST) was performed using seven housekeeping genes (16S rRNA, gyrA, gyrB, infB, recN, rpoA and topA). A minimal spanning tree was constructed for each sequence type (ST) by using software BioNumerics 7.1.   Results  The 201 Shewanella isolates collected in China were identified as 10 different species, with S. algae accounting for the largest proportion. There were differences in the distribution of Shewanella among the isolated from different sources, the distribution of S. algae from clinical and food sources was similar. MLST can classified the Shewanella isolates into 136 STs, clonal complex 12 (CC12) was the dominant clonal complexes of S. algae.   Conclusion  The rich pathogenic spectrum of Shewanella distributed in China suggests that the genetic diversity of these strains is high.