Timbermont Leen, Lanckriet Anouk, Pasmans Frank, Haesebrouck Freddy, Ducatelle Richard, Van Immerseel Filip
Department of Pathology, Bacteriology and Avian Diseases, Research Group Veterinary Public Health and Zoonoses, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
Vet Microbiol. 2009 Jun 12;137(3-4):388-91. doi: 10.1016/j.vetmic.2009.01.017. Epub 2009 Jan 20.
Necrotic enteritis in broiler chickens is associated with Clostridium perfringens type A, carrying the NetB toxin. C. perfringens type A is also a member of the normal intestinal microbiota of broilers. Clinically healthy chickens carry several different C. perfringens clones in their intestine. In flocks suffering from necrotic enteritis, however, mostly only one single clone is isolated from the gut of all the diseased animals. Selective proliferation of these clinical outbreak strains in the gut and spread within the flock seems likely, but an explanation has not yet been given. The hypothesis that necrotic enteritis associated C. perfringens strains might suppress the growth of normal microbiota C. perfringens strains, was therefore tested. Twenty-six C. perfringens strains isolated from healthy broilers and 24 clinical outbreak isolates were evaluated for their ability to induce intra-species growth-inhibition in an in vitro setup. A significantly higher proportion of the C. perfringens clinical outbreak strains inhibited the growth of other C. perfringens strains compared to C. perfringens strains isolated from the gut of healthy chickens. It is proposed that, in addition to toxin production, intra-species growth-inhibition may be a virulence trait that contributes to the ability of certain C. perfringens strains to cause necrotic enteritis in broilers.
肉鸡坏死性肠炎与携带NetB毒素的A型产气荚膜梭菌有关。A型产气荚膜梭菌也是肉鸡正常肠道微生物群的成员。临床健康的鸡肠道内携带几种不同的产气荚膜梭菌克隆。然而,在患有坏死性肠炎的鸡群中,从所有患病动物的肠道中分离出的大多只有一个单一克隆。这些临床暴发菌株在肠道内的选择性增殖以及在鸡群中的传播似乎是可能的,但尚未给出解释。因此,对坏死性肠炎相关产气荚膜梭菌菌株可能抑制正常微生物群产气荚膜梭菌菌株生长的假说进行了测试。对从健康肉鸡中分离出的26株产气荚膜梭菌菌株和24株临床暴发分离株在体外诱导种内生长抑制的能力进行了评估。与从健康鸡肠道中分离出的产气荚膜梭菌菌株相比,产气荚膜梭菌临床暴发菌株抑制其他产气荚膜梭菌菌株生长的比例显著更高。有人提出,除了毒素产生外,种内生长抑制可能是一种毒力特性,有助于某些产气荚膜梭菌菌株在肉鸡中引起坏死性肠炎的能力。