Extended spectrum beta-lactamase producing Escherichia coli in a tertiary hospital. Is there an increase of resistances to beta lactams?

The increase of isolation of beta-lactamase resistant Escherichia coli (BREC) strains makes treatment difficult. The objective of this study is to evaluate the situation in our environment. Retrospective study including patients who presented positive urine cultures for E. coli in the Department of Health of Castellon between January 2012 and December 2015. We analyzed variables such as age, gender, patient`s origin (outpatient or hospital) and other risk factors. We performed a descriptive analysis to study the prevalence of BREC. 9113 cultures were positive for E Coli, 273(2.9%) of them were BREC. The annual percentage of BREC ranged from 1.7% to 3,4% with no increase over the last years. Mean age was 70 years, without gender differences. 247 cultures came from outpatient patients (90%), being 96% of them women. The factors most frequently associated with BREC were to present UTI over the last year and have received antibiotic treatment the previous 3 months; 50% of these received a beta lactam. In our environment, the isolation of BREC is similar to other series. Most patients come from the outpatient environment, were previously treated with antibiotics and had recurrent UTIs.