Girón J A, Donnenberg M S, Martin W C, Jarvis K G, Kaper J B
Center for Vaccine Development, University of Maryland, Baltimore.
J Infect Dis. 1993 Oct;168(4):1037-41. doi: 10.1093/infdis/168.4.1037.
Enteropathogenic Escherichia coli (EPEC) express an inducible bundle-forming pilus (BFP) associated with the presence of the EPEC adherence factor (EAF) plasmid and localized adherence (LA) on HEp-2 cells. The cloned structural gene (bfpA) encoding BFP was found to be specific for EPEC, as homologous sequences were found only in EPEC and not in other enteropathogens. The bfpA probe was slightly more sensitive than the EAF probe; among EPEC strains with LA, the bfpA and EAF probes hybridized with 99% and 96% of the strains, respectively. Immunoblotting of whole cell lysates of BFP-positive, EAF-positive or -negative, and LA-positive or -negative EPEC strains revealed variations in the size (18,500-21,000) of the expressed structural subunit of BFP, suggesting differences in processing that may account for discrepancies between the bfpA, EAF, and LA. Because the bfpA probe consists primarily of sequences encoding an important EPEC virulence factor, in contrast to the unknown function of sequences contained in the EAF probe, the bfpA probe may be useful in epidemiologic studies to detect EPEC.
肠致病性大肠杆菌（EPEC）表达一种可诱导的束状菌毛（BFP），其与EPEC黏附因子（EAF）质粒的存在以及在人喉表皮样癌细胞（HEp-2细胞）上的局部黏附（LA）有关。编码BFP的克隆结构基因（bfpA）被发现对EPEC具有特异性，因为仅在EPEC中发现了同源序列，而在其他肠道病原体中未发现。bfpA探针比EAF探针稍敏感；在具有LA的EPEC菌株中，bfpA和EAF探针分别与99%和96%的菌株杂交。对BFP阳性、EAF阳性或阴性以及LA阳性或阴性的EPEC菌株的全细胞裂解物进行免疫印迹分析，结果显示所表达的BFP结构亚基的大小（18,500 - 21,000）存在差异，这表明加工过程中的差异可能解释了bfpA、EAF和LA之间的差异。由于bfpA探针主要由编码一种重要的EPEC毒力因子的序列组成，与EAF探针中所含序列未知功能形成对比，bfpA探针可能在流行病学研究中用于检测EPEC。
