Fosfomycin resistance in enterobacteriaceae strains isolated at the CHU Sahloul of Sousse

Abstract

Introduction : Faced with growing emergence of antibiotic resistance and stagnant pharmaceutical innovation, there is interest in old molecules such as fosfomycin. Our objective was to draw up the epidemiological and bacteriological profile of resistance to fosfomycin in our laboratory’s isolated Enterobacteriaceae strains and to assess the place of this molecule compared to the other antibiotics usually tested. Material and methods : A retrospective descriptive study was carried out in the microbiology laboratory over a period of three years on all non-redundant strains of the three most frequently isolated species of Enterobacteriaceae namely: Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae . Epidemiological and bacteriological characteristics were collected from the laboratory’s computer software. The identification as well as the antibiotic sensitivity study were carried out using the VITEK 2® system. The search for beta-lactama and fosfomycin resistance genes was carried out by PCR on 47 multi-resistant antibiotic strains. Results: Among the 6141 Enterobacteriaceae strains included, E. coli was the least resistant to fosfomycin (1.1%) followed by K. pneumoniae (22.7%). Extended-spectrum beta-lactamase secreting E. coli and K. pneumoniae strains retain low resistance to fosfomycin, while resistance among E. cloacae strains (42.3%) and carbapenem-resistant strains is high. The fosA gene was found in 26.3% of K. pneumoniae strains (n=38). Conclusion : The use of fosfomycin must be promoted using a cautious approach, respecting the guidelines and recommendations of scholarly societies in order to prevent the emergence of resistance to this molecule.