RESUMO
Objectives: The aim of this study was to characterize the molecular mechanisms of carbapenem resistance in Klebsiella pneumoniae isolated from the urology department of Annaba hospital, Algeria. Methods: Between January 2015 and September 2017, 14 carbapenem-resistant K. pneumoniae strains were isolated during routine surveillance work at Ibn Roched hospital of Annaba, Algeria, from the urology department. Theses strains were recovered, and carbapenem resistance mechanisms were investigated. The strains were identified by using matrix-assisted laser desorption and ionization time-of-flight mass spectrometry. Antibiotic susceptibility was assessed by using the Kirby-Bauer method, whereas minimum inhibitory concentration of imipenem/ertapenem and colistin was determined by Etest and broth microdilution methods, respectively. Carbapenem resistance determinants were studied by using PCR and sequencing methods and analyzed by BLAST against the Antibiotic Resistance Gene-ANNOTation (ARG-ANNOT) database. Clonal relationship of strains was performed by using multilocus sequence typing (MLST). Transferability of carbapenem resistance genes was assessed by conjugation and transformation experiments. Results: Fourteen carbapenem-resistant K. pneumoniae isolates were found to be resistant to the eight ß-lactam antibiotics tested (except to imipenem for two isolates). Carbapenemase production was positive for all isolates. Molecular characterization revealed that blaKPC-2 and blaOXA-48 genes were detected in 3 (21.4%) and 11 isolates (78.6%), respectively. Other ß-lactamases genes were identified, including blaCTX-M-15, blaSHV-1-or 12, and blaTEM-1. MLST revealed that the 14 isolates belonged to 2 different sequence types (STs), including ST101 (11 OXA-48-producing K. pneumoniae) and ST258 (3 KPC-2-producing K. pneumoniae). PCR amplifications for blaKPC-2 and blaOXA-48 carbapenemases genes performed on extracted plasmids, showed positive results, suggesting that both carbapenemase genes were probably borne by plasmids. Conclusion: We report here the first identification of KPC-2-producing K. pneumoniae ST258 in Algerian hospitals and an outbreak of OXA-48-producing K. pneumoniae isolates ST101 in the urology department of Ibn Roched hospital located in Annaba, Algeria.