Microbial Etiology of Catheter-Associated Urinary Tract Infections in Hospitalized Patients in Tertiary Healthcare

Abstract

Background: Catheter-associated urinary tract infection (CAUTI) is a healthcare-associated infection that leads to morbidity, longer hospital stay, healthcare costs, and antimicrobial resistance. The purpose of this study was to identify the microbial profile, resistance pattern, and risk factors for CAUTI that were multidrug resistant (MDR).

Methodology: This study (n=160) included culture-confirmed CAUTI following at least 48 hours of catheterization, over a period of six months. Data on demographic information, catheter history, comorbidities, hospitalizations, and prior antibiotic use were gathered from a form and medical records. Microbiological methods were used for culture of urine samples, and antimicrobial susceptibility was determined by Kirby–Bauer disk diffusion according to CLSI. MDR was considered resistance to three or more classes of antimicrobial agents. Data were analysed using SPSS version 26.0, Chi-square and Fisher's exact test, and multivariable logistic regression, with p<0.05 considered significant.

Results: The mean age was 58.9 ± 16.4 years, and 56.9% were male. 81.3% of isolates were Gram-negative. The predominant bacteria were Escherichia coli (35.0%), Klebsiella pneumoniae (23.1%), and Pseudomonas aeruginosa (15.0%). The highest levels of resistance were for ampicillin (57.5%), ciprofloxacin (46.3%), ceftriaxone (43.1%) and trimethoprim–sulfamethoxazole (41.3%). Overall, 43.8% of the isolates were MDR. The factors that were independent predictors were as follows: prior antibiotic use (AOR=3.61), admission to the ICU (AOR=3.08), prior hospitalization (AOR=2.09), diabetes mellitus (AOR=2.21), and catheterization for >14 days (AOR=2.84).

Conclusion: Resistant Gram-negative bacteria were the main cause of CAUTI, and there was a high load of MDR. Improved catheter care practices, surveillance, culture-based treatment, and antimicrobial stewardship may help to decrease the rate of MDR CAUTI and enhance outcomes.