OXA-48 type carbapenemase in Klebsiella pneumoniae producing extended spectrum B-lactamases (ESBL) in Senegal

Enterobactericeae producing extended spectrum b-lactamases (ESBL) are likely to express carbapenemases OXA-48 which have hydrolytic activity on carbapenems. The aim of this work was to evaluate prevalence of blaOXA-48 for Klebsiella pneumoniae isolates producing ESBL. This work was conducted at the French Reference Center for Antibiotic Resistance with strains from Senegalese Hospital. Standard antibiogram was performed in accordance to CA-SFM/EUCAST 2016 and presence of ESBL was confirmed by synergistic image. Polymerase chain reaction (PCR) was performed to detect systematically blaOXA-1, blaTEM-1, blaCTX-M-1, blaCTX-M-9 and blaOXA-48 gene in case of decrease sensitivity to carbapenem. PCR products were extracted, purified, sequenced and whole-genome sequence (WGS) were used for the analyses. Plasmids extraction was performed by Kado and Liu method. Five isolates harbored a decreased susceptibility to carbapenems. They were positive for blaOXA-48 gene and also expressed blaCTX-M-15. Analysis of the five plasmids by WGS identified a single IncL/M type plasmid of 63 kb and other genes for aminoglycosides and quinolones resistance. Carbapenemase-producing Enterobacteriaceae represent new threat to public health. Decrease in carbapenem susceptibility should be an alert for rapid detection of carbapenemases and to prevent their spread. Phenotypic or molecular methods should be available in many laboratories to take appropriate preventive and therapeutic measures.  Key words: Klebsiella pneumoniae, extended spectrum b-lactamases (ESBL), carbapenemase, blaOXA-48, Senegal.