Bacterial susceptibility to oral antibiotics in community acquired urinary tract infection

Abstract

Background: The most common oral antibiotics used in the treatment of urinary tract infection (UTI) are sulphonamides and cephalosporins, but emerging resistance is not unusual.

Aims: To assess the change in susceptibility of urinary pathogens to oral antibiotics during the past decade in children with community acquired UTI.

Methods: The study sample included two groups of children with a first community acquired UTI: 142 children enrolled in 1991 and 124 enrolled in 1999. UTI was diagnosed by properly collected urine specimen (suprapubic aspiration, transurethral catheterisation, or midstream specimen in circumcised males) in symptomatic patients. Antimicrobial susceptibility of the isolates was compared between the two groups.

Results: The pathogens recovered in the two groups were similar: in 1991--E coli 86%, Klebsiella 6%, others 8%; in 1999--E coli 82%, Klebsiella 13%, and others 5%. A slight but generalised decrease in bacterial susceptibility to common antibiotics in the two groups was shown: ampicillin 35% versus 30%; cephalexin 82% versus 63% (p < 0.001); nitrofurantoin 93% versus 92%. The only exception was co-trimoxazole, 60% versus 69%. Overall resistance to antibiotics in 1999 was as follows: ampicillin 70%, cephalexin 37%, co-trimoxazole 31%, amoxicillin-clavulanate 24%, nitrofurantoin 8%, cefuroxime-axetil 5%, nalidixic acid 3%.

Conclusions: This study shows a slight but generalised decrease in bacterial susceptibility to common oral antibiotics in the past decade in our population. Empirical initial treatment with co-trimoxazole or cephalexin is inadequate in approximately one third of UTI cases. A larger number of pathogens may be empirically treated with amoxicillin-clavulanate (24% resistance); 95% of organisms are susceptible to cefuroxime-axetil.

Figure 1

Overall resistance of urinary pathogens to oral antibiotics in 1999.