In vitro production of necrotic enteritis toxin B, NetB, by netB-positive and netB-negative Clostridium perfringens originating from healthy and diseased broiler chickens
In vitro production of necrotic enteritis toxin B, NetB, by netB-positive and netB-negative Clostridium perfringens originating from healthy and diseased broiler chickens
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DOI：
10.1016/j.vetmic.2009.12.036
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发表时间：
2010-07-29
影响因子：
3.3
通讯作者：
Hojberg, Ole
中科院分区：
文献类型：
--
作者：
Abildgaard, Lone;Sondergaard, Teis E.;Hojberg, Ole
产气荚膜梭菌坏死性肠炎毒素B(NETB)是新近提出的一种新的肉鸡坏死性肠炎(NE)的致病因子。本研究的目的是调查从丹麦肉鸡群中获得的48株A型产气荚膜梭菌中netB基因的存在和NetB毒素的体外产生。调查发现，netB基因的流行约为。发病鸡群分离株和健康鸡群分离株分别为50%和60%。分离株之间的netB基因编码序列(CDS)只有很小的核苷酸变异，启动子区域完全保守。然而，在体外，从健康禽类中回收的14株netB阳性产气荚膜梭菌中只有4株能产生NetB毒素，而从NE禽类中回收的13株netB阳性菌株中有12株能产生NetB毒素。因此，我们认为，基因型，即netB基因的存在，本身不足以预测产气荚膜梭菌的毒力，未来的研究应集中在细菌表型，NetB基因表达的调控机制，以及潜在的其他毒素。以及它对单个产气荚膜梭菌菌株毒力的影响。(C)2010爱思唯尔B.V.保留所有权利。
The Clostridium perfringens necrotic enteritis toxin B, NetB, was recently proposed as a new key virulence factor for the development of necrotic enteritis (NE) in broilers. The aim of the present study was to investigate the presence of the netB gene and the in vitro production of the NetB toxin in a well characterized collection of 48 C. perfringens Type A isolates, obtained from Danish broiler flocks. The investigation revealed netB gene prevalences of approx. 50% and 60% among isolates from diseased (NE) and healthy flocks, respectively. Only minor nucleotide variations were observed between the isolates in the coding sequence (CDS) of the netB gene, and the promoter region was observed to be completely conserved. However, in vitro NetB production was only observed in 4 out of 14 netB-positive C. perfringens isolates recovered from healthy birds, whereas 12 out of 13 netB-positive isolates from NE birds were shown to produce the NetB toxin. It is therefore proposed that genotype, i.e. presence of the netB gene, in itself is inadequate for predicting virulence of C. perfringens, and future investigations should focus on the bacterial phenotypes; the regulatory mechanisms involved in the expression of NetB, and potentially also other toxins. and its implications for the virulence of individual C. perfringens strains. (C) 2010 Elsevier B.V. All rights reserved.