Background: the basis of urinary tract infection (UTI) diagnosis in children is based on positive results of microbiological tests. The selection of an antimicrobial drug for empirical treatment and prophylaxis of UTI is determined by the susceptibility of bacterial strains isolated from urine cultures.
Aim: Determination of the etiology of urinary tract infections and drug sensitivity of the pathogen in hospitalized children.
Materials and methods: we performed quantitative analyses of 2522 urine cultures from children admitted to the Department of Paediatrics at Warsaw Bielany Hospital, from January 2004 to December 2006. We obtained 456 positive urinary cultures, which accounted for 18.1% of urinary samples (14.7%; 17.9%; 21.2% in successive years).
Results: in 392 (86%) cases the urinary infection was caused by one of the isolated pathogens: Escherichia coli, Klebsiella spp. or Proteus mirabilis. Escherichia coli was the most frequently isolated pathogen (70-74%). We noted that the frequency of isolating of Klebsiella spp. grew from 6 to 10%, whereas that of Proteus mirabilis fell from 10 to 2% in the same years. Likewise, in the period from 2004-2006 we observed the same level of the susceptibility of Gram-negative bacteria to nitrofurantoin (84-88%) and trimethoprim-sulfamethoxazole (90-91%), whereas we observed a non-statistically significant lowering of susceptibility to aminopenicillins, and aminopenicillins combined with beta-lactamase inhibitors (from 92 to 74%; p=0.2). There was a statistically significant decrease in drug susceptibility to nitrofurantoin (from 86 to 60%; p<0.05). However, because the groups of children treated with nitrofurantoin were small (6-8-11 in successive years) further studies are needed.
Conclusion: studies into the etiology of UTI and drug susceptibility of the pathogens in hospitalized children could facilitate correct management of patients receiving empirical treatment and prophylaxis of UTI. Of concern is the noted decrease in the sensitivity of the most frequent pathogen, Escherichia coli, to aminopenicillins and aminopenicillins combined with beta-lactamase inhibitors.