Outer membrane protein A (OmpA) of extraintestinal pathogenic Escherichia coli

Authors: NIELSEN, DANIEL - Orise Fellow; RICKER, NICOLE - Orise Fellow; BARBIERI, NICOLLE - University Of Georgia; Allen, Heather; NOLAN, LISA - University Of Georgia; LOGUE, CATHERINE - University Of Georgia

Submitted to: BMC Research Notes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2020
Publication Date: 1/31/2020
Citation: Nielsen, D., Ricker, N., Barbieri, N.L., Allen, H.K., Nolan, L.K., Logue, C.M. 2020. Outer membrane protein A (OmpA) of extraintestinal pathogenic Escherichia coli. BMC Research Notes. 13. Article 51. https://doi.org/10.1186/s13104-020-4917-5.
DOI: https://doi.org/10.1186/s13104-020-4917-5

Interpretive Summary: Extraintestinal Pathogenic Escherichia coli (ExPEC) are a group of E. coli responsible for disease outside of the gut. ExPEC can be subdivided into different groups by the type of disease that is caused. Neonatal Meningitis Escherichia coli (NMEC) cause bacterial meningitis in newborns, Avian Pathogenic E. coli (APEC) causes disease in birds, and Uropathogenic Escherichia coli (UPEC) is the most common cause of urinary tract infections. Outer membrane protein A is thought to contribute to the ability of NMEC to enter the brain and persist in blood, and the protein has been suggested as a potential target for a vaccine. However, the OmpA protein has differences in its protein sequence, and these differences may result in differences in the function of the protein. We sequenced the ompA gene from APEC, NMEC, and UPEC isolates and translated the gene sequence into protein sequences computationally. Twenty-five different protein sequence patterns were identified. Seven of the twenty-five patterns were statistically significantly associated with an APEC, NMEC, or UPEC subpathotype, but the genetic relatedness of the strains most likely influences this result. The differences in the OmpA protein sequences may be important for examining disease severity or the bird-or-human specificity for APEC, NMEC, and UPEC.

Technical Abstract: Extraintestinal Pathogenic E. coli (ExPEC), are a pathotype of E. coli responsible for disease in hosts that are extraintestinal in nature. Subpathotypes of ExPEC include Neonatal Meningitis Escherichia coli (NMEC), which is the second-leading cause of neonatal bacterial meningitis, Avian Pathogenic E. coli (APEC), a cause of extraintestinal disease in production poultry worldwide that causes significant loses for the industry, and Uropathogenic E. coli (UPEC), the most common cause of urinary tract infections worldwide. Virulence factors associated with NMEC include outer membrane protein A (OmpA) and the type I fimbriae (FimH), which are also contained within APEC and UPEC. Outer membrane protein A (OmpA) contributes to the ability of Neonatal Meningitis Escherichia coli (NMEC) to cross the blood-brain barrier and to persist in the bloodstream. OmpA has been suggested as a potential vaccine target for ExPEC, but the protein has different amino acid variants, which have the potential to alter the pathogenesis or virulence of strains or alter vaccine efficacy. OmpA is present in virtually all E. coli, but differences in its amino acid residues have yet to be surveyed within the ExPEC subpathotypes. Here, we sequenced the ompA gene (n equals 399) from collections of ExPEC and translated the gene in silico. Twenty-five different OmpA polymorphism patterns were identified. Among the ExPEC collection, seven polymorphism patterns were significantly associated with an ExPEC subpathotype, but chromosomal history most likely accounts for the majority of differences among the subpathotypes. The differences observed in the OmpA protein sequences suggest that this protein may be of interest when assessing variation in virulence and host specificity within the ExPEC subpathotype.