Pathogen Characteristic of Biofilm-Related CAUTI in the Intensive Care Unit

Catheter-associated urinary tract infection (CAUTI) in the intensive care unit (ICU) is one of the healthcare-associated infections with increased length of stay, healthcare costs, morbidity, and mortality. CAUTI can be caused by antimicrobial-resistant and biofilm-forming microorganisms, resulting in recurrent and persistent infections. This study is aimed at analyzing the pathogens, antimicrobial sensitivity patterns, and biofilm-forming capabilities of CAUTI isolates in two referral hospitals in Yogyakarta, Indonesia.

A cross-sectional study was conducted on 71 patients with indwelling urinary catheters from October 2022 to March 2023. Urine specimens were collected aseptically and cultured. Microorganisms were identified and tested for antimicrobial susceptibility using Vitek 2, CHROMagar, and broth microdilution. Biofilm-producing bacteria were identified by microtiter plate assay (MTPA), and selected urinary catheters were examined by scanning electron microscopy (SEM).

A total of 71 urine specimens from patients with indwelling latex-urinary catheters resulted in 49 bacterial isolates and 28 yeasts identified. Escherichia coli, Acinetobacter baumannii, and Candida albicans were the most frequent pathogens. Among Enterobacterales, 62.5% were extended-spectrum β-lactamase (ESBL) producers, whereas 90% of A. baumannii and 20% of Pseudomonas aeruginosa isolates were carbapenem-resistant. In contrast, C. albicans and C. tropicalis showed a fairly good level of sensitivity to various antifungals. Biofilm formation was observed in 91.8% of bacterial and in all Candida isolates. SEM examination of urinary catheter segments and tips revealed biofilm structures and microbial morphologies consistent with urine culture findings.

E. coli, A. baumannii, and C. albicans were the predominant CAUTI pathogens. Most isolates exhibited biofilm-forming ability. Although bacteria showed high antibiotic resistance, yeasts remained relatively susceptible to antifungals.