Useful independent factors for distinguish infection and colonization in patients with urinary carbapenemase-producing Enterobacteriaceae isolation.

The aim of this study is to know epidemiologic and clinical differences among those patients colonized or infected by carbapenemase-producing Enterobacteriaceae (CPE) and develop a predictive model to facilitate the clinical approach concerning to start antimicrobial therapy.Observational retrospective cohort study was performed involving all patients with Urine carbapenemase-producing Enterobacteriaceae isolation (UCPEI) between November 2013 and July 2015. Patients were classifieds as colonized or infected considering Center for Disease Control and Prevention (CDC) definition for urinary tract infection (UTI).A total of 72 patients were included, mean age 76.4 (IQR 23-99) years and 40 (55.6%) were women. Thirty-four (47.2%) were colonized and 38 (52.8%) met the criteria of UTI and were considered infected. The independent variables associated to infection were female sex, peripheral vascular disease, admission in medical ward, permanent urinary catheter carrier, previous antimicrobial therapy, and length of stay. Isolation of OXA-48 carbapenemase-producing Enterobacteriaceae behaved as a non UTI (colonization) factor in comparison with KPC or VIM CPE. The developed predictive model showed an area under the curve (AUC) of 0.901 (95% CI: 0.832-0.970; p < 0.001).The predictive model that includes all this factors has demonstrated a good accuracy for infection diagnosis in these patients, an important issue considering that establishing the diagnosis of infection is not always easy in the profile of patients in which a CPE is isolated.