Infection and Drug Resistance (Apr 2019)
Investigation of six plasmid-mediated quinolone resistance genes among clinical isolates of pseudomonas: a genotypic study in Saudi Arabia
Abstract
Mohamed F El-Badawy,1,2 Majed M Alrobaian,3 Mohamed M Shohayeb,1,4 Sayed F Abdelwahab1,51Division of Pharmaceutical Microbiology, Department of Pharmaceutics and Industrial Pharmacy, College of Pharmacy, Taif University, Taif 21974, Kingdom of Saudi Arabia; 2Department of Microbiology and Immunology, Faculty of Pharmacy, Misr University for Science and Technology, Al-Motamayez District 12568, Egypt; 3Department of Pharmaceutics and Industrial Pharmacy, College of Pharmacy, Taif University, Taif 21974, Kingdom of Saudi Arabia; 4Department of Microbiology and Biotechnology, Faculty of Pharmacy, Delta University for Science and Technology, Gamasa 35712, Egypt; 5Department of Microbiology and Immunology, Faculty of Medicine, Minia University, Minia, 61511, EgyptBackground: Quinolones are among the most effective antibiotics against Pseudomonas spp. Several chromosomal and/or plasmid-mediated quinolone-resistance mechanisms have been found in Pseudomonas. Plasmid-mediated quinolone-resistance (PMQR) is mediated by quinolone-resistance (QNR) proteins, modifying enzymes or efflux pumps. Only a few previous studies examined the prevalence of quinolone-resistance in the Kingdom of Saudi Arabia (KSA) and showed it is increasing. Mechanisms of quinolone-resistance among Pseudomonas spp. in the KSA; examined herein; have not been extensively studied.Methods: Ninety-two Pseudomonas isolates were collected and their resistance to seven different types of quinolones was determined by the microbroth dilution method. PMQR mechanisms were examined using a PCR screen to identify six PMQR genes including qnrA, qnrB, qnrD, qnrS, aac(6´)-Ib-cr, and qepA. Clonal relatedness of the quinolone-resistant isolates was determined by ERIC-PCR.Results: Of the isolates, 42.4% (39/92) were resistant to 1-7 of the tested quinolones. Gemifloxacin resistance was the lowest (28.3%) while resistance to the other six quinolones were ≥ 35%. The most common biotype among the 39 quinolone-resistant isolates was resistance to the seven tested quinolones (26/39; 66.7%). qnrD, qnrS, and aac(6´)-Ib-cr were found in 31 (79.5%), 31 (79.5%) and 28 (71.8%) of the 39 isolates, respectively, and all three genes together were found in 22 of the 39 isolates (56.4%). qnrA, qnrB, and qepA were not detected in any of the isolates and two isolates did not harbor any of the six tested genes. The isolates showed 38 different ERIC profiles and only two isolates (Pa16 and Pa17) had an identical profile.Conclusion: This is the first description of PMQR mechanisms among clinical Pseudomonas isolates from the KSA, which appears to be mainly mediated by qnrD, qnrS, and aac(6´)-Ib-cr.Keywords: aac(6´)-Ib-cr, flouoroquinolones, Pseudomonas, qepA, qnr, QRDR, quinolones, aac(6´)-Ib-cr, flouoroquinolones, qepA, KSA, qnr, QRDR, Taif
