Mobley Research Laboratory: Department of Microbiology & Immunology: University of Michigan Medical School
 

Uropathogenic Escherichia coli

Background

Urinary tract infection (UTI) is the most frequently diagnosed kidney and urologic disease and Escherichia coli is by far its most common etiologic agent [1, 2] . Uropathogenic E. coli (UPEC) infections account for more than 80% of uncomplicated UTIs [3] and occur in otherwise healthy individuals with the majority of infections affecting women [3] .

Recurrent UTI, defined as three or more episodes of UTI during a 12-month period, is common among girls and young nonpregnant women who are healthy and have anatomically normal urinary tracts. These infections are a main source of morbidity and health-care cost in this population [4] and are caused by different UPEC strains as often as caused by the same strain [5] .

Extraintestinal pathogenic E. coli (ExPEC) strains associated with cystitis and acute pyelonephritis (UPEC) are not a random sample of E. coli. Indeed, 75% of isolates reside within only six of the more than 200 O-serogroups of this species [6] . This subset differs from the majority of fecal strains. Demonstrating that uropathogenic E. coli are true pathogens, outbreaks by particular strains have been documented [7] , indicating that these strains are capable of causing infections in immunocompetent hosts.

Antibiotic treatment, typically with trimethoprim/sulfamethoxazole or ciprofloxacin, is generally effective for eradication of the infecting strain. However, there is documentation of increases in antibiotic resistance [8] , allergic reaction to certain pharmaceuticals, alteration of normal gut flora, and failure to prevent recurrent infections. The idea of vaccination has been approached by several groups, however, without marked or long lasting protection [9-14, 15] .

The genome of type strain, E. coli CFT073, isolated by us from a hospitalized patient with acute pyelonephritis and bacteremia [16] has been sequenced and annotated in a collaborative effort [17]. In addition, using a pathogen-specific microarray, we have determined the expression levels for all genes from E. coli CFT073 collected directly from the urine of experimentally infected mice [18] . This identified all genes that were expressed in vivo. These and other recent findings are outlined on this site.