Urinary infections and Citrobacter: An unpleasant scenario

Abstract

Urinary infections due to Citrobacter is very common, and rising antibiotic resistance complicates the situation.Urine samples received in the microbiology laboratory at Al Azhar Medical College from October 1st, 2018 to September 30th, 2019, were processed. Isolates identified as Citrobacter were studied. 3207 urine samples were processed, of which 2481 showed significant growth. 124 Citrobacter isolates were identified, of which 72 were C. koseri and 52 were C. freundii. For C. koseri, susceptibility to co-amoxyclav, 3rd generation cephalosporins and co-trimoxazole ranged from 60-70%. Susceptibilities to fluoroquinolones and nitrofurantoin was 76-77%. For C. freundii, susceptibility to 3rd generation cephalosporins was around 50%. Susceptibilities to co-trimoxazole and fluoroquinolones was around 60% and for nitrofurantoin, it was 67.31%. Susceptibility for both was good for aminoglycosides and piperacillin-tazobactam. Nearly 45% isolates were resistant to 3 or more antibiotic classes. Our data shows that upto a third of urinary infections due to Citrobacter can end up with treatment failure with the usual empirical antibiotics, and the management must be tailored based on evidence from culture and sensitivity reports.