UpaH is a newly identified autotransporter protein that contributes to biofilm formation and bladder colonization by uropathogenic Escherichia coli CFT073.
Escherichia coli is the primary cause of urinary tract infection (UTI) in the developed world. The major factors associated with virulence of uropathogenic E. coli (UPEC) are fimbrial adhesins, which mediate specific attachment to host receptors and trigger innate host responses. Another group of adhesins is represented by the autotransporter (AT) subgroup of proteins. In this study, we identified a new AT-encoding gene, termed upaH, present in a 6.5-kb unannotated intergenic region in the genome of the prototypic UPEC strain CFT073. Cloning and sequencing of the upaH gene from CFT073 revealed an intact 8.535-kb coding region, contrary to the published genome sequence. The upaH gene was widely distributed among a large collection of UPEC isolates as well as the E. coli Reference (ECOR) strain collection. Bioinformatic analyses suggest beta-helix as the predominant structure in the large N-terminal passenger (alpha) domain and a 12-strand beta-barrel for the C-terminal beta-domain of UpaH. We demonstrated that UpaH is expressed at the cell surface of CFT073 and promotes biofilm formation. In the mouse UTI model, deletion of the upaH gene in CFT073 and in two other UPEC strains did not significantly affect colonization of the bladder in single-challenge experiments. However, in competitive colonization experiments, CFT073 significantly outcompeted its upaH isogenic mutant strain in urine and the bladder.
School of Chemistry and Molecular Biosciences, Building 76, University of Queensland, Brisbane QLD 4072, Australia.
Luke P
LP
Allsopp
Makrina
M
Totsika
Jai J
JJ
Tree
Glen C
GC
Ulett
Amanda N
AN
Mabbett
Timothy J
TJ
Wells
Bostjan
B
Kobe
Scott A
SA
Beatson
Mark A
MA
Schembri
D000818:Animals; D018441:Biofilms / Q000254:growth & development*; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004195:Disease Models, Animal; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology*; D005260:Female; D017353:Gene Deletion; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017422:Sequence Analysis, DNA; D001743:Urinary Bladder / Q000382:microbiology*; D014552:Urinary Tract Infections / Q000382:microbiology; D056689:Uropathogenic Escherichia coli / Q000472:pathogenicity*; D037521:Virulence Factors / Q000235:genetics / Q000502:physiology*
D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C548680:UpaH protein, E coli; D037521:Virulence Factors