Waters Michael, Savoie Amanda, Garmory Helen S, Bueschel Dawn, Popoff Michel R, Songer J Glenn, Titball Richard W, McClane Bruce A, Sarker Mahfuzur R
Department of Microbiology, Oregon State University, Corvallis, Oregon 9731, USA.
J Clin Microbiol. 2003 Aug;41(8):3584-91. doi: 10.1128/JCM.41.8.3584-3591.2003.
Although Clostridium perfringens is recognized as an important cause of clostridial enteric diseases, only limited knowledge exists concerning the association of particular C. perfringens toxinotypes (type A to E) with gastrointestinal (GI) diseases in domestic animals. Some C. perfringens isolates also produce the newly discovered beta2-toxin (CPB2). Recent epidemiological studies suggested that C. perfringens isolates carrying the gene encoding CPB2 (cpb2) are strongly associated with clostridial GI diseases in domestic animals, including necrotic enteritis in piglets and typhlocolitis in horses. These putative relationships, obtained by PCR genotyping, were tested in the present study by further genotyping and phenotyping of 29 cpb2-positive C. perfringens isolates from pigs with GI disease (pig GI disease isolates). PCR and restriction fragment length polymorphism analysis reconfirmed the presence of cpb2 gene sequences in all the disease isolates included in the study. Furthermore, genotyping by pulsed-field gel electrophoresis analyses showed that the pig GI disease isolates included in this study all carry a plasmid cpb2 gene, yet no clonal relationships were detected between the cpb2-positive pig GI disease isolates surveyed. Finally, CPB2-specific Western blotting demonstrated CPB2 expression by all of the cpb2-positive isolates surveyed. The CPB2 proteins made by five of these pig GI disease isolates were shown to have the same deduced amino acid sequences as the biologically active CPB2 protein made by the original type C isolate, CWC245. Collectively, our present results support a significant association between CPB2-positive C. perfringens isolates and diarrhea in piglets.
尽管产气荚膜梭菌被认为是梭菌性肠道疾病的重要病因，但关于特定产气荚膜梭菌毒素型（A至E型）与家畜胃肠道（GI）疾病之间的关联，目前所知有限。一些产气荚膜梭菌分离株还产生新发现的β2毒素（CPB2）。最近的流行病学研究表明，携带编码CPB2基因（cpb2）的产气荚膜梭菌分离株与家畜的梭菌性胃肠道疾病密切相关，包括仔猪坏死性肠炎和马的盲结肠炎。通过PCR基因分型获得的这些假定关系，在本研究中通过对29株来自患有胃肠道疾病猪的cpb2阳性产气荚膜梭菌分离株（猪胃肠道疾病分离株）进行进一步的基因分型和表型分析进行了验证。PCR和限制性片段长度多态性分析再次证实了本研究中所有疾病分离株中cpb2基因序列的存在。此外，脉冲场凝胶电泳分析的基因分型表明，本研究中包含的猪胃肠道疾病分离株均携带质粒cpb2基因，但在所调查的cpb2阳性猪胃肠道疾病分离株之间未检测到克隆关系。最后，CPB2特异性蛋白质印迹法证明了所有所调查的cpb2阳性分离株均表达CPB2。其中五株猪胃肠道疾病分离株产生的CPB2蛋白与原始C型分离株CWC245产生的具有生物活性的CPB2蛋白具有相同的推导氨基酸序列。总体而言，我们目前的结果支持cpb2阳性产气荚膜梭菌分离株与仔猪腹泻之间存在显著关联。
