驴源猪链球菌2型的分离和鉴定及MLST分型

Streptococcus suistype 2 strain from donkey:isolation,identification,and MLST typing

2017年4月,山东省济宁嘉祥县、梁山县和聊城东阿县的多个驴场从外地购买的驴相继发生体温升高、流鼻涕、咳嗽、呼吸困难等症状,病情严重的驴出现死亡。从5个驴场分别剖检5头病死驴,均表现化脓性肺炎及败血症病变,采集一典型病例的组织,进行细菌分离培养,并通过病理组织学检查、革兰染色、生化鉴定、血清学鉴定、16S基因序列分析以及MLST（aroA、cpn60、dpr、gki、mutS、recA、thrA）分型研究,此外还分析了中国目前所流行的ST型以及不同ST型之间的关系。结果显示：病原为猪链球菌2型;16SDNA序列与国内外部分地区菌株序列的同源性达到99%～100%;MLST分型为ST2型;该分离菌株对林可霉素、青霉素、阿莫西林、头孢噻呋钠产生耐药性,对左氧氟沙星、氟苯尼考高度敏感。

In April 2017, donkeys manifested fever, cough and dyspnea in J iaxiang county, Liangshan county and Dong＇e county, Shandong province, which were transported from other regions. And several donkeys died of serious condition. Five donkeys from five donkey farms showed suppura- tive pneumonia and septicemia after pathological autopsy. Tissues were collected from dead donkeys with typical pathological changes and were carried out histopathological observation, bacterial isolation and culture, drug sensitivity test. The isolated bacteria was identified by gram staining, biochemical test, serological test, sequence analysis of 16S gene and MLST （aroA, cpn60, dpr, glei, mutS,recA and thrA）. In addition,the relationship of currently popular between ST type and different ST types was analyzed in China. The results showed that one strain of Streptococcus suis type 2 was isolated and identified and its 16S DNA sequence shared 99%- 100% homology with at of strains in some regions at home and abroad. It was ST2 type according to the MLST method. The isolated strain was resistant to lincomycin, penicillin, amoxicillin and ceftiofur sodium, but it was highly sensitive to levofloxacin and florfenicol.