Yadegari Zahra, Nikbakht Brujeni Gholamreza, Ghorbanpour Reyhaneh, Moosakhani Farhad, Lotfollahzadeh Samad
Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Department of Microbiology, Faculty of Veterinary Medicine, Branch of Karaj, Islamic Azad University, Karaj, Iran.
Vet Res Forum. 2019 Winter;10(1):73-78. doi: 10.30466/vrf.2019.34313. Epub 2019 Mar 15.
Enterotoxigenic (ETEC) produces different virulence factors allowing the bacterium to colonize and develop watery diarrhea. Proteomics studies have also introduced new protein belonging to the secretion pathways, antigen 43 (Ag43), which plays important role in pathogenesis. The objective of this study was to investigate O-types and virulence factors of isolates from neonatal calves diarrhea. Total of 120 isolates from diarrheic calves were genotyped for their O groups and the presence of virulence genes K99, F41 and STa as well as Ag43. The predominant O-type was O101 (51.00%) and the prevalence of K99, F41 and STa was 7 (5.80%). The Ag43 was detected in all samples with three different allelic patterns. Our results indicated that K99 positive isolates certainly have one of each 2200 bp or 1800 bp or both copies of Ag43 passenger domain, while negative K99 isolates lack the Ag43. The results reported here provide informative data regarding the prevalence of O-types and their virulence factors in enteric colibacillosis. The Ag43 that was more found in K99 positive isolates might be associated with diarrhea-causing strains in neonatal calves.
产肠毒素大肠杆菌（ETEC）产生不同的毒力因子，使该细菌能够定殖并引发水样腹泻。蛋白质组学研究还发现了属于分泌途径的新蛋白——抗原43（Ag43），它在发病机制中起重要作用。本研究的目的是调查新生犊牛腹泻分离株的O型及毒力因子。对120株腹泻犊牛分离株进行了O群基因分型，并检测了毒力基因K99、F41、STa以及Ag43的存在情况。优势O型为O101（51.00%），K99、F41和STa的流行率为7株（5.80%）。在所有样本中均检测到Ag43，且有三种不同的等位基因模式。我们的结果表明，K99阳性分离株肯定具有2200 bp或1800 bp的Ag43乘客结构域拷贝之一或两者皆有，而K99阴性分离株则缺乏Ag43。此处报告的结果提供了有关肠道大肠杆菌病中O型及其毒力因子流行情况的信息性数据。在K99阳性分离株中更常见的Ag43可能与新生犊牛腹泻致病菌株有关。
