Nielsen Daniel W, Ricker Nicole, Barbieri Nicolle L, Allen Heather K, Nolan Lisa K, Logue Catherine M
Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, 1802 University Blvd, Ames, IA, 50011, USA.
Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, ARS-USDA, Ames, IA, USA.
BMC Res Notes. 2020 Jan 31;13(1):51. doi: 10.1186/s13104-020-4917-5.
Extraintestinal Pathogenic E. coli (ExPEC), are responsible for host diseases such as Neonatal Meningitis Escherichia coli (NMEC), the second-leading cause of neonatal bacterial meningitis, Avian Pathogenic E. coli (APEC), a cause of extraintestinal disease in poultry, and Uropathogenic E. coli (UPEC), the most common cause of urinary tract infections. Virulence factors associated with NMEC include outer membrane protein A (OmpA) and type I fimbriae (FimH), which also occur in APEC and UPEC. OmpA contributes to NMEC's ability to cross the blood-brain barrier, persist in the bloodstream and has been identified as a potential vaccine target for ExPEC, however the protein has amino acid variants, which may influence virulence of strains or alter vaccine efficacy. Although OmpA is present in virtually all E. coli, differences in its amino acid residues have yet to be surveyed in ExPEC.
Here the ompA gene (n = 399) from ExPEC collections were sequenced and translated in silico. Twenty-five different OmpA polymorphism patterns were identified. Seven polymorphism patterns were significantly associated with an ExPEC subpathotype, but chromosomal history most likely accounts for most differences found. The differences in OmpA protein sequences suggest that OmpA may influence variation in virulence and host specificity within ExPEC subpathotypes.
肠外致病性大肠杆菌（ExPEC）可引发宿主疾病，如新生儿脑膜炎大肠杆菌（NMEC），它是新生儿细菌性脑膜炎的第二大病因；禽致病性大肠杆菌（APEC），可导致家禽的肠外疾病；以及泌尿道致病性大肠杆菌（UPEC），是尿路感染最常见的病因。与NMEC相关的毒力因子包括外膜蛋白A（OmpA）和I型菌毛（FimH），这两种因子在APEC和UPEC中也存在。OmpA有助于NMEC穿越血脑屏障、在血流中持续存在，并且已被确定为ExPEC的潜在疫苗靶点，然而该蛋白存在氨基酸变体，这可能会影响菌株的毒力或改变疫苗效力。尽管几乎所有大肠杆菌中都存在OmpA，但其氨基酸残基的差异在ExPEC中尚未得到研究。
在此对来自ExPEC样本的ompA基因（n = 399）进行了测序，并在计算机上进行了翻译。鉴定出了25种不同的OmpA多态性模式。七种多态性模式与ExPEC亚致病型显著相关，但染色体历史很可能是所发现的大多数差异的原因。OmpA蛋白序列的差异表明，OmpA可能会影响ExPEC亚致病型内毒力和宿主特异性的变化。
