Open AccessIdentification and characterization of OmpT‐like proteases in uropathogenic Escherichia coli clinical isolates
Author(s) -
Desloges Isabelle,
Taylor James A.,
Leclerc JeanMathieu,
Bran John R.,
Portt Andrea,
Spencer John D.,
Dewar Ken,
Marczynski Gregory T.,
Manges Amee,
Gruenheid Samantha,
Le Moual Hervé,
Thomassin JennyLee
Publication year - 2019
Publication title -
microbiologyopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.881
H-Index - 36
ISSN - 2045-8827
DOI - 10.1002/mbo3.915
Subject(s) - proteases , escherichia coli , microbiology and biotechnology , biology , protease , asymptomatic bacteriuria , virulence , antimicrobial peptides , enzyme , gene , antimicrobial , biochemistry , urine , bacteriuria
Abstract Bacterial colonization of the urogenital tract is limited by innate defenses, including the production of antimicrobial peptides (AMPs). Uropathogenic Escherichia coli (UPEC) resist AMP‐killing to cause a range of urinary tract infections (UTIs) including asymptomatic bacteriuria, cystitis, pyelonephritis, and sepsis. UPEC strains have high genomic diversity and encode numerous virulence factors that differentiate them from non‐UTI‐causing strains, including ompT . As OmpT homologs cleave and inactivate AMPs, we hypothesized that UPEC strains from patients with symptomatic UTIs have high OmpT protease activity. Therefore, we measured OmpT activity in 58 clinical E. coli isolates. While heterogeneous OmpT activities were observed, OmpT activity was significantly greater in UPEC strains isolated from patients with symptomatic infections. Unexpectedly, UPEC strains exhibiting the greatest protease activities harbored an additional ompT ‐like gene called arlC ( ompTp ). The presence of two OmpT‐like proteases in some UPEC isolates led us to compare the substrate specificities of OmpT‐like proteases found in E. coli . While all three cleaved AMPs, cleavage efficiency varied on the basis of AMP size and secondary structure. Our findings suggest the presence of ArlC and OmpT in the same UPEC isolate may confer a fitness advantage by expanding the range of target substrates.