Clinical management of ESBL-producing Enterobacteriaceae : the insidious role of fluoroquinolones

During a review of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in our Hospital, a huge number of inadequate antimicrobial therapies emerged. The aim of this study is to assess the factors related to such inadequacy. This retrospective analysis was performed on isolates reported by the microbiology laboratory. Medical records were analyzed to assess adequate treatment; inadequacy was evaluated as overall therapy, antibiotic choice, dosage and length of treatment. Linear regression and multivariate analysis were performed to assess any association. One hundred and fifty isolates were analyzed. They were more commonly isolated from urinary samples and from patients admitted to the Internal Medicine Department; E. coli was the most commonly isolated pathogen. The rate of inadequacy was 60.67%. Fluoroquinolones seem to be the main class responsible. Ceftriaxone, teicoplanin, tigecycline and amoxicillin-clavulanate are other antibiotics inadequately prescribed. Clinical management of these infections should be better tailored: the knowledge of pathogens should be implemented and the use of diagnostic tools, such as microbiology results, must be optimized. In particular, the prescription of each antibiotic course (and above all of regimens containing fluoroquinolones) should be performed not on a routine basis, but after careful assessment of each case.