Lebrun M, Filée P, Mousset B, Desmecht D, Galleni M, Mainil J G, Linden A
Department of Infectious and Parasitic Diseases (Bacteriology), Faculty of Veterinary Medicine, University of Liège, Liège 4000, Belgium.
Vet Microbiol. 2007 Feb 25;120(1-2):151-7. doi: 10.1016/j.vetmic.2006.10.020. Epub 2006 Oct 25.
Clostridium perfringens has been implicated in a broad array of enteric infections including the fatal haemorrhagic enteritis/enterotoxaemia syndrome in cattle. The beta2 toxin (CPB2), encoded by cpb2, is suspected to be implicated in this syndrome. However, among C. perfringens isolates from cattle suspected of clostridial disease, an atypical allele was recently found to predominate at the cpb2 locus and atypical corresponding CPB2 proteins were shown to be poorly expressed, thus arguing against a biologically significant role of the beta2 toxin in clostridial diseases in cattle. This study compared genotype and phenotype of the beta2 toxin between C. perfringens isolates from a group of healthy calves (n=14, 87 isolates) and from a group of enterotoxaemic calves (n=8, 41 isolates). PCR results revealed the exclusive presence of the typical "consensus"cpb2 in the enterotoxaemic group. Western blot analysis demonstrated that the typical variant of CPB2 was often expressed in isolates from enterotoxaemic calves (43.9%) and infrequently in isolates from healthy cattle (6.9%). These data suggest that the typical variant of the CPB2 toxin may play a role in the pathogenesis of cattle enterotoxaemia.
产气荚膜梭菌与多种肠道感染有关，包括牛的致命性出血性肠炎/肠毒血症综合征。由cpb2编码的β2毒素（CPB2）被怀疑与该综合征有关。然而，在从疑似患有梭菌病的牛中分离出的产气荚膜梭菌菌株中，最近发现一个非典型等位基因在cpb2位点占主导地位，并且相应的非典型CPB2蛋白表达不佳，因此反对β2毒素在牛梭菌病中具有生物学显著作用的观点。本研究比较了来自一组健康犊牛（n = 14，87株菌株）和一组患肠毒血症犊牛（n = 8，41株菌株）的产气荚膜梭菌分离株中β2毒素的基因型和表型。PCR结果显示，在患肠毒血症的组中仅存在典型的“共识”cpb2。蛋白质印迹分析表明，CPB2的典型变体在患肠毒血症犊牛的分离株中经常表达（43.9%），而在健康牛的分离株中很少表达（6.9%）。这些数据表明，CPB2毒素的典型变体可能在牛肠毒血症的发病机制中起作用。
