CONICET | Buscador de Institutos y Recursos Humanos

Abstract: Urinary tract infection (UTI) is a common cause of morbidity and mortality in older adults. Antimicrobial resistance in UTI produced by Escherichia coli in elderly patients attending to a General Hospital was investigated. During the period July 2011-July 2015, patients over 70 years-old, without urinary catheters and no antimicrobial therapy seven days before sampling and with urinary infection symptoms were included. N: 3,920 urine samples were analyzed. Phenotypic characterization was carried out with conventional tests. In vitro qualitative (disk diffusion method) and quantitative (Minimum Inhibitory Concentration, broth dilution) antimicrobial resistance according to Clinical and Laboratory Standards Institutes`s recommendations was performed. Antimicrobials assayed: ampicillin, amoxicillin-clavulanate acid, cephalotin, cefuroxime, cefoxitin, cefotaxime, ceftazidime, cefepime, imipenem, ertapenem, gentamicin, nalidixic acid, ciprofloxacin, trimethoprim-sulfamethoxazole (TMS) and nitrofurantoin. Included E. coli isolates expressed resistance to ampicillin (80.5%), nalidixic acid (61.7%), ciprofloxacin (42.8%), TMS (37.6%), amoxicillin-clavulanate (28.6%), cephalotin (21.6%), cefuroxime (20.7%), gentamicin (12.1%), cefotaxime (9.7%), ceftazidime (9.7%), cefepime (8.4%), cefoxitin (3.1%) and nitrofurantoin (2.3%). Resistance to carbapenems was not observed. Production of ESBL was detected (7.6%) in community acquired (96%) and health-care associated (4%) isolates. A high prevalence of resistance to beta-lactams and to other antimicrobials was observed in E. coli isolates from patients over 70 years-old with UTI. Detection of antimicrobial multi-resistant isolates highlights the need of a continuous surveillance of antimicrobial resistance in adult patients with UTI produced by E. coli.