Dissemination and systemic colonization of uropathogenic Escherichia coli in a murine model of bacteremia.
Infection with uropathogenic Escherichia coli (UPEC), the causative agent of most uncomplicated urinary tract infections, proceeds in an ascending manner and, if left untreated, may result in bacteremia and urosepsis. To examine the fate of UPEC after its entry into the bloodstream, we developed a murine model of sublethal bacteremia. CBA/J mice were inoculated intravenously with 1 × 10(6) CFU of pyelonephritis strain E. coli CFT073 carrying a bioluminescent reporter. Biophotonic imaging, used to monitor the infection over 48 h, demonstrated that the bacteria disseminated systemically and appeared to localize at discrete sites. UPEC was recovered from the spleen, liver, kidneys, lungs, heart, brain, and intestines as early as 20 min postinoculation, peaking at 24 h postinoculation. A nonpathogenic E. coli K-12 strain, however, disseminated at significantly lower levels (P < 0.01) and was cleared from the liver and cecum by 24 h postinoculation. Isogenic mutants lacking type 1 fimbriae, P fimbriae, capsule, TonB, the heme receptors Hma and ChuA, or particularly the sialic acid catabolism enzyme NanA were significantly outcompeted by wild-type CFT073 during bacteremia (P < 0.05), while flagellin and hemolysin mutants were not.
Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA.
Sara N
SN
Smith
Erin C
EC
Hagan
M Chelsea
MC
Lane
Harry L T
HL
Mobley
D000825:Animal Structures / Q000382:microbiology; D000818:Animals; D016470:Bacteremia / Q000382:microbiology* / Q000473:pathology*; D004195:Disease Models, Animal; D004927:Escherichia coli Infections / Q000382:microbiology* / Q000473:pathology*; D048168:Escherichia coli K12 / Q000472:pathogenicity; D049449:Luminescence; D051379:Mice; D008808:Mice, Inbred CBA; D013194:Staining and Labeling / Q000379:methods; D013997:Time Factors; D056689:Uropathogenic Escherichia coli / Q000472:pathogenicity*; D014774:Virulence; D037521:Virulence Factors / Q000172:deficiency / Q000235:genetics; D051598:Whole Body Imaging
D037521:Virulence Factors