G型产气荚膜梭菌的分离鉴定及其在鸡坏死性肠炎发病模型中的应用

Isolation and identification of Clostridium perfringens type G and its application in the pathogenesis model of necrotizing enteritis in chickens

目的:探讨不同诱导因素对鸡坏死性肠炎(Necrotic enteritis,NE)的诱发效果,以便建立鸡坏死性肠炎的发病模型。方法:以安徽省某规模化鸡场采集的病鸡肠道样品中分离出的G型产气荚膜梭菌(Clostridium perfringens,C.perfringens)(CPG-AH5株)为病原菌,分析单独或联合感染毒害艾美耳球虫对在饲喂高蛋白饲料(添加鱼粉)和不饲喂高蛋白饲料条件下,诱发鸡坏死性肠炎的影响。结果:无诱导因素时,1.1×10^(9)CFU/mL剂量下CPG-AH5株感染可造成肠道损伤(平均病变评分为1.5±0.85分);单一诱导因素(鱼粉或球虫)不能有效促进CPG-AH5株的感染,肠道病变与无诱导因素条件下无显著性提高(2.0±1.15、2.4±1.08,P>0.05);多个诱导因素(鱼粉和球虫)联合诱导可有效促进CPG-AH5株的感染,与无诱导因素和单一诱导因素相比肠道病变显著性提高(3.6±0.52,P<0.001)。结论:鱼粉和球虫联合诱导可显著促进G型产气荚膜梭菌的感染,提高肠道病变。本研究建立了一种鸡坏死性肠炎发病模型,有利于对鸡坏死性肠炎发病机制的研究,为疫苗及药物的后续研发和筛选评价提供了新的技术支撑。

Objective:This study investigates the influence of various inducing factors on the induction of necrotic enteritis(NE)in chickens,aiming to establish a pathogenesis model for necrotizing enteritis in chickens.Methods:This study used Clostridium perfringens type G(C.perfringens),specifically the CPG-AH5 strain isolated from the intestinal samples of diseased chickens collected from a large-scale poultry farm in Anhui Province,as the pathogen to analyze the effects of either single or co-infection with Eimeria spp.on inducing necrotic enteritis in chickens,under conditions of being fed a high-protein diet(with fish meal added)and not being fed a high-protein diet.Results:In the absence of inducing factors,an inoculation with a dose of 1.1×10^(9) CFU/mL of the CPG-AH5 strain can cause intestinal damage(with an average lesion score of 1.5±0.85).Single inducing factors(either fish meal or coccidia)do not effectively enhance the infection by the CPG-AH5 strain,and there is no significant increase in intestinal lesions compared to conditions without inducing factors(2.0±1.15,2.4±1.08,P>0.05).However,the combination of multiple inducing factors(fish meal and coccidia)effectively promotes the infection by the CPG-AH5 strain,with a significant increase in intestinal lesions compared to both the absence of inducing factors and the presence of single inducing factors(3.6±0.52,P<0.001).Conclusion:The combined induction of fish meal and coccidia significantly enhances the infection by Clostridium perfringens type G,increasing intestinal lesions.This study has established a model for necrotic enteritis in chickens,which is beneficial for researching the pathogenesis of necrotic enteritis in chickens and provides new technical support for the subsequent research and development,and selection evaluation of vaccines and drugs.