INVASIVE ESCHERICHIA-COLI INFECTIONS IN CHILDREN - BACTERIAL CHARACTERISTICS IN DIFFERENT AGE-GROUPS AND CLINICAL ENTITIES

Escherichia coli isolates from blood or cerebrospinal fluid of 135 chi ldren were characterized for serotype, adhesin and hemolysin productio n and compared with 94 fecal isolates from healthy children. Capsular type K1, serogroup 018 and rough-type lipopolysaccharide were predomin ant in neonatal infections (49, 16 and 16%, respectively) and also in meningitis and septicemia of infants from 7 days to 23 months of age ( 39, 17 and 13%). S-fimbriated strains were common in neonatal infectio ns (23%) but rare (less-than-or-equal-to 5%) in all other clinical gro ups. Pyelonephritis was the most common diagnosis in infants (49 of 72 ); it was associated with P-fimbriation (63%); serogroups O1, O2, O4, O6 or O7 (41%), and hemolysin production (37%). Invasive infections in older children (age greater-than-or-equal-to 2 years) were associated with predisposing factors and were caused by strains resembling fecal isolates; the only exception was hemolysin production which was detec ted in 40% of the disease but only 9% of the fecal isolates. Eight O:K :H serotypes were associated with invasive infections; they usually ha d K1 or K5 capsule and either P, S or type 1C fimbriae.