Comparison of Escherichia coli uropathogenic genes (kps, usp and ireA) and enteroaggregative genes (aggR and aap) via multiplex polymerase chain reaction from suprapubic urine specimens of young children with fever

Abstract

Objective. Escherichia coli is the most frequently identified microbiological agent in childhood urinary tract infections (UTIs). However, the pathogenic role of this organism in young children remains to be clearly elucidated. So far, no studies have been conducted in which multiplex polymerase chain reaction (PCR) has been applied to determine the association between childhood UTIs and E. coli and urovirulent genes. Material and methods. Altogether, 330 suprapubic urine specimens from febrile young children were cultured. In 33 of the cases, E. coli was identified; among these cases, 18 had a UTI (>104-105 cfu/ml), four had a suspected UTI (>102-103 cfu/ml) and 11 did not have UTIs (102 cfu/ml). Using multiplex PCR, three uropathogenic E. coli (UPEC) genes and two enteroaggregative E. coli (EAEC) genes were detected. Results. In the UTI-UPEC cases, the kps gene was detected in 18 of 22 cases (82%) and the usp gene in 16 of 22 cases (73%). Among the 18 cases of children with UTIs characterized by 104-105 E. coli cfu/ml, urinary tract abnormalities were identified via dimercaptosuccinic acid scans in seven of 18 cases (39%) and via voiding cystourethrograms in four of the 18 cases (22%). Conclusions. The UPEC kps and usp genes were clearly associated with childhood UTIs, and may also be associated with kidney or urinary tract dysfunctions in young children. Escherichia coli colony count numbers in excess of 104-105 cfu/ml in the suprapubic urine were considered to be strong evidence of UTI in infants. © 2009 Informa UK Ltd. (Informa Healthcare, Taylor & Francis AS).