345株福氏志贺菌血清型分布与PFGE分子分型

Serotype distribution of 345 Shigella Flexneri strains and PFGE molecular typing

目的了解引起细菌性痢疾的福氏志贺菌PFGE分子分型特征,为新疆细菌性痢疾的预防和控制提供科学依据。方法对2013年-2016年细菌性腹泻病例粪便样本中分离出的345株福氏志贺菌,经生化和血清学鉴定,确认血清型,经NotI酶切,对占比前3位优势菌型的DNA指纹图谱进行聚类分析。结果 345株福氏志贺菌中,血清型以F2a型占比最高(47.83%),其次为F2b型(14.49%)、F1b型(10.72%)。按照相似度100%,可将PFGE图谱分为225种型别,带型呈现多样性,其中163株F2a型呈现97种带型,有4种优势带型,49株F2b型有41种带型,37株F1b型PFGE有31种带型。结论福氏志贺菌因血清型复杂,PFGE带型呈现多样性,带型分布呈个别带型集中,其他带型菌株间并存相近的多种变异,较为分散。带型间的差异与福氏志贺菌抗原结构复杂,血清型多,菌株来源地区、生存条件和环境的不同有关。

Objective To explore the molecular typing characteristics of Shigella Flexneri strains, so as to to provide technology basis for precaution and control of bacillary dysentery in Xinjiang. Methods A total of 345 Shigella Flexneri strains, which were isolated from samples of faeces of bacterial diarrhea cases during 2013-2015, were conducted for biochemical and serological identification so as to identify the serotypes. By NotI restriction enzyme digestion, the DNA fingerprints of top three dominant serotypes with high proportion were conducted for cluster analysis. Results Among the 345 strains of Shigella Flexneri, type 2 a was the dominant(47.83%), followed by type 2 b(14.49%), and type 1 b(10.72%). According to the similarity of 100%, the PFGE patterns can be divided into 225 types, which showed diversity. 163 strains of type 2 a presented 97 band patterns, which included 4 dominant band patterns. 49 strains of type 2 b showed 41 band patterns, and 37 strains of type 1 b presented 31 band patterns. Conclusion Because of the complexity of Shigella Flexneri serotype, PFGE types showed various band patterns. It was embodied in that several band patterns showed concentrating distribution, and other strains had multiple similar variations and were in dispersed distribution. Differences among band patterns were related to complicated structure of antigens of Shigella Flexneri, a great variety of serotypes, and distinctions of sourcing regions, living conditions and environments of strains.