Observational study over 8-year period evaluating microbiological characteristics and risk factor for isolation of multidrug-resistant organisms (MDRO) in patients with healthcare-associated infections (HAIs) hospitalized in a urology ward

Objective: To analyze, in a urology ward, the prevalence and characteristics of healthcare-associated infections (HAIs) due to multidrug-resistant organisms (MDRO). Methods: We carried out an observational study from 2012 to 2019, evaluating MDRO among patients with HAIs, who were hospitalized in the urology ward. MDRO include Pseudomonas spp., resistant to at least three antibiotic groups, extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae or those resistant to carbapenems, and Enterococcus spp. resistant to vancomycin. Results: Among patients with HAIs, MDRO were isolated in 100 out of 438 (22.8%) positive cultures. Univariate and multivariate analyses reported that prior urinary tract infection (UTI) [OR 2.45; 95% CI 1.14–5.36; p=0.021] and immunosuppression [OR 2.13; 95% CI 1.11–4.10; p=0.023] were risk factors for MDRO. A high prevalence of MRDO was found in patients with a catheter in the upper urinary tract; 27.6% for double J stent, 29.6% in those with a nephrostomy tube, and 50% in those with a percutaneous internal/external nephroureteral (PCNU) stent. MDRO were isolated in 28.4% of cultures with Enterobacteriaceae (23.8% and 44.7% in those with E. coli and Klebsiella spp.); 7% of Enterobacteriaceae showed resistance to carbapenems (1.3% and 10% for E. coli and Klebsiella spp., respectively). Three out of 80 Enterococcus spp. were vancomycin-resistant. The rate of Pseudomonas aeruginosa resistant to at least three antibiotic groups was 36.3%. Conclusions: The isolation of MDRO, in up to 25% of positive cultures in a urology ward, constitutes a challenge for the selection of antibiotics. MDRO are more common in immunosuppressed patients, those with previous UTIs, and those with a catheter in the upper urinary tract.