Bacterial species and antimicrobial resistance differ between catheter and non-catheter-associated urinary tract...

To investigate clinically relevant microbiological characteristics of uropathogens and to compare patients with catheter-associated urinary tract infections (CAUTIs) to those with non-CAUTIs.

All urine cultures from the calendar year 2019 of the Swiss Centre for Antibiotic Resistance database were analyzed. Group differences in the proportions of bacterial species and antibiotic-resistant isolates from CAUTI and non-CAUTI samples were investigated.

Data from 27,158 urine cultures met the inclusion criteria. Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis together represented 70% and 85% of pathogens identified in CAUTI and non-CAUTI samples, respectively. Pseudomonas aeruginosa was significantly more often detected in CAUTI samples. The overall resistance rate for the empirically often-prescribed antibiotics ciprofloxacin (CIP), norfloxacin (NOR), and trimethoprim-sulfamethoxazole (TMP-SMX) was between 13% and 31%. Except for nitrofurantoin, E. coli from CAUTI samples were more often resistant (P ≤ .048) to all classes of antibiotics analyzed, including third-generation cephalosporines used as surrogate for extended-spectrum β-lactamase (ESBL). Significanty higher resistance proportions in CAUTI samples versus non-CAUTI samples were observed for CIP (P = .001) and NOR (P = .033) in K. pneumoniae, for NOR (P = .011) in P. mirabilis, and for cefepime (P = .015), and piperacillin-tazobactam (P = .043) in P. aeruginosa.

CAUTI pathogens were more often resistant to recommended empirical antibiotics than non-CAUTI pathogens. This finding emphasizes the need for urine sampling for culturing before initiating therapy for CAUTI and the importance of considering therapeutic alternatives.