Open AccessIn Vivo Gene Expression Analysis Identifies Genes Required for Enhanced Colonization of the Mouse Urinary Tract by Uropathogenic Escherichia coli Strain CFT073 dsdA
Author(s) -
Brian J. Haugen,
Sabine Pellett,
Peter Redford,
Holly Hamilton,
Paula L. Roesch,
Rodney A. Welch
Publication year - 2007
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.01319-06
Subject(s) - escherichia coli , mutant , microbiology and biotechnology , gene , fimbria , operon , in vivo , chemistry , gene expression , enterobacteriaceae , biology , biochemistry , genetics
Deletional inactivation of the gene encodingd -serine deaminase,dsdA , in uropathogenicEscherichia coli strain CFT073 results in a hypermotile strain with a hypercolonization phenotype in the bladder and kidneys of mice in a model of urinary tract infection (UTI). The in vivo gene expression profiles of CFT073 and CFT073dsdA were compared by isolating RNA directly from the urine of mice challenged with each strain individually. Hybridization of cDNAs derived from these samples to CFT073-specific microarrays allowed identification of genes that were up- or down-regulated in thedsdA deletion strain during UTI. Up-regulated genes included the knownd -serine-responsive genedsdX , suggesting in vivo intracellular accumulation ofd -serine by CFT073dsdA. Genes encoding F1C fimbriae, both copies of P fimbriae, hemolysin, OmpF, a dipeptide transporter DppA, a heat shock chaperone IbpB, and clusters of open reading frames with unknown functions were also up-regulated. To determine the role of these genes as well as motility in the hypercolonization phenotype, mutants were constructed in the CFT073dsdA background and tested in competition against the wild type in the murine model of UTI. Strains with deletions of one or both of the two P fimbrial operons,hlyA ,fliC ,ibpB , c0468, locus c3566 to c3568, or c2485 to c2490 colonized mouse bladders and kidneys at levels indistinguishable from wild type. CFT073dsdA c2398 and CFT073dsdA focA maintained a hypercolonization phenotype. A CFT073dsdA dppA mutant was attenuated 10- to 50-fold in its colonization ability compared to CFT073. Our results support a role ford -serine catabolism and signaling in global virulence gene regulation of uropathogenicE. coli .