First Detection of the Plasmid-Mediated Quinolone Resistance Determinants qnrB, qnrS and aac(6’)-Ib-cr in Extended Spectrum Beta-Lactamases-producing Klebsiella pneumonia in Bouaké, Côte d’Ivoire

Aims: The aims of the present study were to investigate the presence of Plasmid-Mediated Quinolone Resistance (PMQR) determinants and the association of these determinants with Extended Spectrum Beta-Lactamases (ESBLs) genes in ESBL-producing Klebsiella pneumoniae isolates from Teaching Hospital of Bouaké, Côte d’Ivoire.

Study Design: It is a retrospective study.

Place of Study: Bacteriology-Virology Laboratory of Teaching Hospital, Bouaké, Côte d'Ivoire.

Methodology: From January 2015 to December 2016, 96 ESBL-producing Klebsiella pneumoniae isolates were collected from several specimens. Antimicrobial susceptibility of isolates was tested using the standard disk-diffusion method on Mueller-Hinton and interpretation according to recommendations of the 2017 EUCAST. These isolates analyzed for the detection of ESBL (blaCTX-M, blaTEM and blaSHV) and PMQR genes (aac(6’)-Ib-cr, qnrB and qnrS) using simplex PCR.

Results: Of the 96 ESBL-producing strains, 85 (88.55%) harbored at least one of the ESBL genes tested. Out of the 85 strains encoding ESBL genes, 96.47% carried blaCTX-M and 92.94% blaSHV and blaTEM genes. Eighty nine (89.6%) of the 96 ESBL producing-isolates were resistant to ciprofloxacin and 84.4% to norfloxacin. Among the 96 strains, 80 (83.33%) were found harboring at least one PMQR gene consisting of 78 (81.3%) aac(6’)-Ib-cr, 61 (63.5%) qnrB and 15 (15.6%) qnrS. Among the PMQR-positive strains, 68.4% coharbored qnrB+acc(6’)-Ib-cr genes, 10.5% qnrB+qnrS+acc(6’)-Ib-cr and 6.6% qnrS+acc(6’)-Ib-cr. The qnrB gene was always linked to aac(6’)-Ib-cr gene. Aac(6’)-Ib-cr gene showed the highest association with three ESBL genes (87.6%), followed by qnrB gene (70.6%), then qnrS (17.7%).

Conclusion: The PMQR genes were highly prevalent in ESBL-producing Klebsiella pneumoniae, primarily the aac(6’)-Ib-cr gene. The high associated was observed between ESBL and PMQR genes, notably with the aac(6’)-Ib-cr gene.