Detection of gyrA and parC Mutations and Prevalence of Plasmid-Mediated Quinolone Resistance Genes in Klebsiella pneumoniae
Received 6 August 2020
Accepted for publication 14 December 2020
Published 12 February 2021 Volume 2021:14 Pages 555—563
Checked for plagiarism Yes
Review by Single anonymous peer review
Peer reviewer comments 3
Editor who approved publication: Professor Suresh Antony
Sawsan Mohammed Kareem,1 Israa MS Al-kadmy,1,2 Saba S Kazaal,1 Alaa N Mohammed Ali,1 Sarah Naji Aziz,1 Rabab R Makharita,3 Abdelazeem M Algammal,4 Salim Al-Rejaie,5 Tapan Behl,6 Gaber El-Saber Batiha,7 Mohamed A El-Mokhtar,8 Helal F Hetta8,9
1Branch of Biotechnology, Department of Biology, College of Science, University of Mustansiriyah, Baghdad, Iraq; 2Faculty of Science & Engineering, School of Engineering, University of Plymouth, Plymouth, PL4 8AA, UK; 3Botany Department, Faculty of Science, Suez Canal University, Ismailia, 41522, Egypt; 4Department of Bacteriology, Immunology and Mycology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt; 5Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia; 6Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, India; 7Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicines, Damanhour University, Damanhour, 22511, Egypt; 8Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut, 71515, Egypt; 9Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
Correspondence: Helal F Hetta
University of Cincinnati College of Medicine, Department of Internal Medicine, PO Box 670595, Cincinnati, OH, 45267-0595, USA
Israa MS Al-kadmy
Faculty of Science & Engineering, School of Engineering, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, United Kingdom
Background and Aim: Recently, the extensive use of quinolones led to increased resistance to these antimicrobial agents, with different rates according to the organism and the geographical region. The aim of this study was to detect the resistance rate of Klebsiella pneumoniae Iraqi isolates toward quinolone antimicrobial agents, to determine genetic mutations in gyrA and parC, to screen for efflux-pump activity, and to screen the presence of plasmid-mediated quinolone resistance (PMQR) genes.
Methods: Forty-three K. pneumoniae isolates were confirmed phenotypically and genotypically by Vitek 2 system and species specific primers by PCR using the targeting rpo gene followed by sequencing. Antibiotic susceptibility test was carried out using disc diffusion method. Quinolone resistant isolates were subjected to ciprofloxacin MIC testing, and cartwheel method to screen for efflux pump activity. The presence of the plasmid mediated quinolone resistance genes qepA, qnrB, qnrS, and aac(6)Ib was tested by PCR. Sequencing of gyrA and parC was performed.
Results: We observed a high rate of resistance to ceftriaxone, gentamicin ciprofloxacin, and levofloxacin. Low rate of resistance was detected against amikacin and azithromycin. Ciprofloxacin MIC results revealed that 96.1% of the isolates had MICs > 256 μg/mL, 83.4% had MICs > 512 μg/mL while 34.6% had MIC > 1024 μg/mL. Testing of isolates against ciprofloxacin mixed with EtBr at various concentrations resulted in decreased resistant. Sequencing results showed that Ser83Leu was the most common mutation in gyrA that was observed in all quinolone resistant isolates, followed by Asp87Asn. Ser80Ile mutation in parC was observed in 77.7% of the tested isolates. The prevalence of PMQR genes was 92.5% aac (6)-Ib, 51.8% qnrB, 40.7% qepA, and 37% qnrS.
Conclusion: Quinolone resistance is common in K. pneumoniae isolates in Baghdad. The frequent mutation in gyrA and parC, and the presence of PMQR genes is alarming.
Keywords: MDR K. pneumoniae, quinolones resistance gene, PMQR
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