Correlation between electrophoretic types B1 and B2 of carboxylesterase B and sex of patients in Escherichia coli urinary tract infections.

One hundred and sixty-eight strains of Escherichia coli isolated from 84 men and 84 women who had urinary tract infections (134 cases) or bacteremia of urinary tract origin (34 cases) were assessed for their carboxylesterase B electrophoretic types B1 and B2, alpha-haemolysin production, the presence of mannose resistant haemagglutinin (MRHA) and antibiotic susceptibility. Electrophoretic type B2 was phenotypically linked with alpha-haemolysin and MRHA productions. The strains isolated from males were more frequently of type B2, haemolytic and both haemolytic and haemagglutinating than those isolated from females. The strains isolated during bacteremia were more frequently haemolytic and haemagglutinating than those obtained from urinary tract infections. Type B1 strains were more frequently resistant to antimicrobial agents than type B2 strains. The results reinforced the distinction, in terms of virulence and antibiotic sensitivity, between B1 and B2 strains and demonstrated the influence of the sex of patients on the host-parasite interaction during urinary tract infections.