RESUMO
Colicin production was studied among 137 Escherichia coli strains isolated from pregnant patients with symptomatic or asymptomatic, urinary tract infection (IVU). The observed colicinogeny frequency was 72.92% (n = 96), among the symptomatic patients and 29.26% (n = 41) among the asymptomatic group. The most frequently identified colicins from symptomatic patients were: V (23.9%), A (18.7%) and E1 (17.7%) and within the patients with asymptomatic IVU the most frequently observed colicins were A (9.7%), E1 (17.0%) y V (2.4%). The major frequency of colicin V among the E. coli strains isolated from the symptomatic group against the asymptomatic one, was statistical significant (p > or = 0.025). The results on the observed frequencies of colicins E1 and A were not statistical significant. Among the 137 studied E. coli strains, 37.2% were hemolytic. 83.3% of the colicin V producing strains (n = 24) were hemolytic, among the strains producing other colicin different than colicin V 34% (n = 58) were hemolytic and 12.0% of non colicinogenic strains were hemolytic. These results were statistical significant (p > 0.05). The present data, suggest that colicins production is an important pathogenicity factor among the E. coli strains, specially for those strains producing colicin V. The observed association among hemolysin and colicin V production may be an interesting pathogenicity factor which suggests an increasing ability of uropathogenic strains to produce symptomatic urinary tract infections.