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Frequency of virulence genes among urinary, periurethral and fecal escherichia coli

Abstract:

Uropathogenic E. coli probably consist of several different classes groupable by virulence mechanism. To begin identifying these classes, we described the presence of 9 different virulence genes among first UTI (n=237), peri-urethral (n=54) and fecal (n=270) E. coli isolates from otherwise healthy women aged 18 to 39. Using dot blot hybridization, first UTI, peri-urethral and fecal E. coli isolates were significantly different from each other in frequency of genes for aerobactin (p=0.025), CNFI (p<0.001), Dr (p<0.001), hemolysin (p<0.001), Capsule II (p<0.001), OmpT (p<0.001), S fimbrial adhesin (p<0.001), a conserved probe for P fimbrial adhesins (p<0.001), and two P subtypes: prsGJ96 (p<0.001) and papGAD (p=0.09). All isolates screened had fim genes. When grouped by the frequency of all factors present, strains positive for fim, ompT and kpsMT only occurred twice as frequently among periurethral than among first UTI or fecal isolates (20% versus 8% and 10%). These data suggest there may be a separate class of E. coli that prefers the periurethral area.