福建省北部地区鼠类钩端螺旋体感染状况及分离株分子特征研究

Infection status and molecular characteristics of Leptospira in rodents in northern Fujian Province

目的了解福建省北部地区鼠类钩端螺旋体(钩体)感染状况及分子特征。方法对捕获的鼠类进行信息登记,采集鼠肾进行PCR检测,确定其感染状况。EMJH培养基用于鼠肾标本的钩端螺旋体菌株分离。应用MAT方法对分离株进行血清群鉴定。分别采用16S rRNA、MLST和PFGE的方法对分离株进行分子分型。结果共捕获鼠类227只,检出感染钩端螺旋体的鼠类27只,检出率为11.89%,野栖鼠检出率高于家栖鼠,雄性鼠检出率高于雌性鼠。共分离到4株钩端螺旋体分离株,分离率为1.76%(4/227)。血清学分群显示4株分离株均为黄疸出血群。基因种分型显示4株分离株均为Leptospira interrogans。MLST分型将4株分离株分为2个ST型,PC29、PC30为ST1型,JY19、JY37为ST17型。4株分离株呈现2种PFGE带型,其中,PC29、PC30与黄疸出血群参考株带型一致,JY19、JY37与波摩那群带型具有较高相似度,聚类关系相对较近。结论福建省北部地区的鼠类中存在钩端螺旋体感染。黄疸出血群和Leptospira interrogans分别为福建省北部地区钩端螺旋体的优势血清群和优势基因种,具有不止一种的ST型和PFGE带型,且ST型与PFGE带型呈现地域差异。

This study aimed to investigate the infection status and molecular characteristics of Leptospira in rodents in northern Fujian Province.A total of 227 rodents were captured,and data were recorded.Rodent kidneys were collected for PCR detection.A total of 27 rodents were infected with Leptospira,with a positivity rate of 11.89%.The positivity rate was higher in wild rodents than commensal rodents,and in male than female rodents.EMJH medium was used to isolate Leptospira strains from kidney specimens.Four Leptospira isolates were obtained,with an isolation rate of 1.76%(4/227).The serum group of isolates was identified with the MAT method,All isolates were of the icterohaemorrhagic serogroup.Subsequently,16S rRNA sequencing indicated that all four isolates were Leptospira interrogans.Two sequence types were obtained by MLST:PC29 and PC30 were ST1,and JY19 and JY37 were ST17.PFGE indicated that the four strains of Leptospira interrogans could be classified into two PFGE types:PC29 and PC30 were consistent with the icterohaemorrhagic serogroup reference strain,whereas JY19 and JY37 had high similarity with the Pomona serogroup.Thus,Leptospira infection is present in rodents in northern Fujian Province.The icterohaemorrhagic serogroup and Leptospira interrogans are the dominant serogroup and genotype,respectively,of Leptospira in northern Fujian province.The MLST and PFGE results showed regional differences.