Antimicrobial resistance in ESKAPEE pathogens isolated from institutionalized vs. non-institutionalized elderly patients with urinary tract infections: a 5-years study

Abstract Background Urinary tract infections are frequently diagnosed in institutionalized patients, often resulting in unnecessary antibiotic use, especially in asymptomatic cases. This, along with prevalent asymptomatic bacteriuria in the elderly, contributes to antimicrobial resistance, with nursing homes serving as key reservoirs. Aim method This study aims to delineate the burden of AMR in ESKAPEE uro-pathogens among elderly patients (aged ≥ 65 years) and to assess the impact of institutionalization on AMR rates, in accordance with EUCAST guidelines. Method A retrospective observational study was carried out between 2016 and 2020 using urine culture data obtained from the Microbiology Department of Hospital San Pedro (Spain). Positive urine cultures were reviewed, and isolates belonging to the ESKAPEE group of pathogens were identified and analyzed anonymously. Results A total of 34,791 urine cultures were analyzed, of which 26,127 (75.1%) were from the ESKAPEE group. Escherichia coli was identified as the most frequently isolated ESKAPEE pathogen (80.5%). Institutionalized patients showed significantly higher AMR rates for numerous antibiotics compared to their non-institutionalized counterparts, particularly manifest in the pronounced resistance rates to fluoroquinolones and a greater prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in nursing homes (p<0.001). Additionally, NH settings demonstrated increased rates of multidrug-resistant (MDR) strains of Escherichia coli and Klebsiella pneumoniae , underscoring a critical challenge in managing UTIs in these environments. Conclusion In anticipation of a potential post-antibiotic era, it is imperative to enhance infection control measures and antibiotic stewardship in nursing homes to address the growing burden of MDR bacteria and safeguard patient health.