Carbapenemases and extended-spectrum beta-lactamases producing ă Enterobacteriaceae isolated from Tunisian and Libyan hospitals
Résumé
Introduction: The aim of the study was to investigate the prevalence of ă extended-spectrum beta-lactamase (ESBL) and carbapenemase production ă among clinical isolates of Enterobacteriaceae recovered from Tunisian ă and Libyan hospitals. ă Methodology: Bacterial isolates were recovered from patients in ă intensive care units and identified by biochemical tests and MALDI-TOF. ă Antibiotic susceptibility testing was performed by disk diffusion and ă the E-test method. ESBL and carbapenemase activities were detected using ă standard microbiological tests. Antibiotic resistance-encoding genes ă were screened by PCR and sequencing. Clonal relationships between ă Klebsiella pneumoniae strains were carried out using multi-locus ă sequence typing (MLST). ă Results: A total of 87 isolates were characterized, with 51 and 36, ă respectively, identified as E. coli and K. pneumoniae. Overall the ă resistance prevalence was high for aminoglycosides (> 60%), ă fluoroquinolones (> 80%), and extended-spectrum cephalosporins (> ă 94%), and was low for imipenem (11.4%). Among this collection, 58 ă strains (66.6%) were ESBL producers and 10 K. pneumoniae strains ă (11.4%) were carbapenemase producers. The antibiotic ă resistance-encoding genes detected were blaC(TX-M-15) (51.7%), ă bla(TEM-1) (35.6%), several variants of bla(SHV) (21.8%), and ă bla(OXA-48) (11.4%). The MLST typing of K. pneumoniae isolates revealed ă the presence of multiple clones and three novel sequence types. Also, ă close relationships between the OXA-48-producing strains from Tunisia ă and Libya were demonstrated. ă Conclusions: This study is the first paper describing the emergence of ă carbapenemase-and ESBL-producing Enterobacteriaceae, sensitive to ă colistin, isolated in Tunisia and Libya. Active surveillance and testing ă for susceptibility to colistin should be implementing because resistance ă to colistin, mainly in Klebsiella, has been recently reported worldwide.