山羊结肠小袋纤毛虫和A型产气荚膜梭菌混合感染的病原学分析

Pathogenic Analysis of Mixed Infection of Balantioides coli and Clostridium perfringens in Goats

山羊腹泻由多种病原引起,其中结肠小袋纤毛虫和产气荚膜梭菌均为可导致山羊腹泻的重要人兽共患病原。江苏省南通市某养殖场山羊暴发以严重腹泻为主要症状的多起死亡病例。本试验通过临床解剖检查,肠道内容物镜检以及细菌分离、纯化和鉴定(革兰染色试验、细菌16S rDNA基因PCR鉴定)等方法,确诊该起病例由大量结肠小袋纤毛虫滋养体和产气荚膜梭菌混合感染所引起;细菌16S rDNA基因序列遗传进化分析显示,本试验分离的山羊产气荚膜梭菌与芬兰的猪源菌株(GenBank:CP075903.1)亲缘关系最近;毒力基因分型结果显示,该分离菌属A型产气荚膜梭菌;药敏试验结果显示,该分离菌主要对氨基糖苷类抗生素表现为耐药。本病例病原学分析结果为临床生产中山羊腹泻的防控工作提供理论依据,并提示寄生虫在混合感染疾病发生和发展中的重要性和危害性。

Goat diarrhea is caused by many pathogens,among which Balantioides coli and Clostridium perfringens are important zoonotic pathogens.Death with severe diarrhea as the main symptom occurred in some goats from a breeding farm in Nantong,Jiangsu province.A combination of autopsy,microscopic examination,bacterial isolation,purification and identification(including Gram staining test and 16S rDNA gene PCR identification)confirmed that the case was due to the mixed infection of B.coli and C.perfringens.Genetic evolution analysis based on 16S rDNA gene sequence revealed a closest relationship between C.perfringens isolated from goats in this study and the strain from pigs in Finland(GenBank:CP075903.1).Typing of virulence genes identified the isolate as C.perfringens type A.Drug susceptibility test indicated that this C.perfringens strain was mainly resistant to aminoglycoside antibiotics.Thus,pathogenic analysis of this case provides a solid basis for the prevention and control of goat diarrhea in clinical production,and implies the role and perniciousness of parasites in the initiation and development of mixed infections in goats.