猪链球菌血清未分型菌株的荚膜多糖基因簇分析  

Genetic analyzing capsular polysaccharide synthesis gene loci of the non-serotypeable Streptococcus suis

作　　者：邱小彤 郝琴[1] 白雪梅[1,2] 

机构地区：[1]中国疾病预防控制中心传染病预防控制所,传染病预防控制国家重点实验室,北京102206 [2]南开大学泰达生物技术研究院,分子微生物学与技术教育部重点实验室,天津300457

出　　处：《疾病监测》2016年第11期925-931,共7页Disease Surveillance

摘　　要：目的从基因水平上探究猪链球菌菌株血清不可分型的原因及cps基因簇序列变异规律。方法根据Gen Bank登记号下载并提取41株猪链球菌血清未分型菌株的cps基因簇序列,根据wzy序列确定菌株的cps型别,并与相应血清型标准菌株的cps基因簇进行序列比对研究。结果 41株血清未分型猪链球菌中,共有37株菌的cps型别属于已知血清型。其中18株与其对应的血清型标准菌株的cps基因簇相比出现部分cps基因的插入、缺失、倒转、替换和移码突变等变异;另有19株与其对应的血清型标准菌株的cps基因簇序列相同或相似,除携带血清24型cps基因簇的菌株LSS23、LSS31、LSS37与血清24型标准菌株88-5299A的cps基因簇同源性为96%外,其余16株与其各自的标准菌株的cps基因簇同源性均超过99%。此外,有4株血清未分型菌株属于已知的新cps型别。结论由于猪链球菌cps基因簇序列变异频繁,导致荚膜多糖抗原型别呈多样化趋势,传统的血清凝集方法无法有效应对,亟需引入更灵敏的分子血清分型技术开展监测。Objective To investigate the variations of the capsular polysaccharide synthesis gene（ cps） cluster sequences of41 non-serotypeable Streptococcus suis（ S. suis）. Methods The cps sequences were extracted from draft sequences which were released from Gen Bank database according to the accession numbers. The cps types of non-serotypeable strains were defined based on their wzy sequences and cps loci were compared with corresponding reference strains and analyzed. Results The cps types of 37 non-serotypeable strains were assigned to known reference serotypes. Insertion,deletion,inversion,replacement and frameshift mutation of some cps genes were found in 18 of the 37 strains. The cps sequences of 16 nonserotypeable strains shared high similarity with those of reference strains（ over 99%）,meanwhile the identity of cps cluster sequences from strain LSS23,LSS31,LSS37 to their reference strain 88- 5299A（ serotype 24） was 96%. Four nonserotypeable strains carrying known novel cps loci were also found. Conclusion The sequence variation of cps loci of S. suis is ongoing,which cannot be identified effectively by serum agglutination. A more sensitive molecular serotyping strategy is needed.

关 键 词：猪链球菌 血清未分型 荚膜多糖基因簇 基因特征 

分 类 号：R378.12[医药卫生—病原生物学]