FREQUENCY OF ESCHERICHIA-COLI K ANTIGENS IN URINARY-TRACT INFECTIONS IN CHILDREN

The somatic (0) and capsular (K) antigens of Escherichia coli from the urine of patients with acute pyelonephritis, acute cystitis and asymptomatic bacteriuria, and in the feces of healthy schoolchildren were investigated. Typing antisera for 16 capsular acidic polysaccharide K antigens were used, and 5 (numbers 1, 2, 3, 12 and 13) accounted for 70% of isolates from patients with acute pyelonephritis. These 5 K antigens were found to a lesser extent in the 3 other study groups. Thus, only a few K polysaccharides are associated with virulent properties of E. coli for the upper urinary tract, a finding similar to the association of only some capsular types of pneumococci, meningococci and Haemophilus influenzae with invasiveness. The identification of virulence markers for E. coli associated with upper urinary tract disease may permit more successful control with reference to preventive immunization.