[Clinical significance of serotypization of Escherichia coli isolated in children urinary tract].

The paper deals with the study of 65 children, aged from 1 to 16,5 years (7 years and 5 months +/- 2 years and 7 months), with urinary tract infection caused by Escherichia coli (E. coli). All patients were classified into three groups according to accepted criteria from literature (clinical features, urographic characteristics, immunological analyses and laboratory signs of inflammatory reaction: (1) 10 patients with chronic pyelonephritis (CP); (2) 34 patients with acute pyelonephritis (AP), and (3) 21 patients with lower urinary tract infection (LUTI). Using 7 antisera antigen preparations O1, O2, 04, O7, O11, O15 and O18, 46 (70.8%) isolated strains were serotyped, while 19 (29.2%) isolated strains of E. coli remained unserotyped. None of the patients showed the presence of more than one serotype in urine. Due to the small number of cases in some groups and low number of serotype strains within the groups, break-down of serotype by patient groups was not done. The prevalent serogroup was O7 found in 22 (47.8%) patients, then O11 in 9 (19.6%), O1 in 4 (8.7%), O15 in 4 (8.7%), O4 in 3 (6.5%), O2 in 2 (4.3%) and O18 in 2 (4.3%) patients. Serogroup O7 was present in all three groups of patients. Statistical analysis showed that the incidence of serogroup O7 was not significantly different (p > 0.05); this suggests that a specific serogroup does not cause only one type of infection. Having in mind that all existing antisera were not used, the possibility of intra-hospital infection provoked by O7 serogroup should be taken into consideration.