Colicin V production by clinical isolates of Escherichia coli.

Strains of Escherichia coli isolated from random fecal samples, urines of hospitalized and nonhospitalized patients who had urinary tract infections, and blood of patients with septicemia were examined for colicin V production. The percentage of ColV+ strains isolated from blood (31.6%) or from urines of hospitalized patients with urinary tract infections (26.2%) was significantly greater (P less than 0.01) than the percentage isolated from feces (13.6%). The colicin V immunity determinant of ColV,I-K94 conferred immunity to 26% of the type V colicins produced by clinical isolates. Of the ColV+ strains studied, 63.6% produced at least one other type of colicin.