Risk Factors for Bacteremias Caused by Extended-Spectrum Beta-Lactamase-Producing Enterobacteria

Bacteraemia caused by enterobacterias are a diagnostic and therapeutic challenge because of their frequency, morbidity/mortality, and their acquisition of resistance mechanisms. The goal was to distinguish the clinical, microbiological and epidemiologic profile of these bacteraemias. An observational, analytic, retrospective, case - control study with clinic history revision was performed. The starting point was the isolation of an enterobacteria from a blood culture, performed for healthcare purposes, from patients with bacteraemia. Within this group of enterobacterias certain strains produce enzymes that hydrolyze oximino-penicillins and are called extended spectrum betalactamase (ESBL). One hundred patients with positive blood culture admitted in the Hospital de Clinicas "Dr. Manuel Quintela" were included in the study. The results showed that nosocomial bacteraemias were the most prevalent. Community acquired infections caused by non-ESBL Enterobacteriaceae were more frequent, this difference was statistically significant. The risk factors for developing bacteraemias caused by ESBL Enterobacteriaceae are: patients with kidney insufficiency undergoing hemodialysis, previous hospitalizations, bladder catheter carriers and chronic kidney disease. The most frequent microorganisms isolated both in community and nosocomial levels were Escherichia coli and Klebsiella pneumoniae. According to the results, it is recommended to start antibiotic treatment with carbapenems when an ESBL Enterobacteriaceae is suspected and it is imperative to know all the risk predictors. This study promotes further research on the clinical and microbiological patterns of these bacteraemias in Uruguay.