Detection of gyrA and parC Mutations and Prevalence of Plasmid-Mediated Quinolone Resistance Genes in Klebsiella pneumoniae

Sawsan Mohammed Kareem; Israa M S Al-Kadmy; Saba S Kazaal; Alaa N Mohammed Ali; Sarah Naji Aziz; Rabab R Makharita; Abdelazeem M Algammal; Salim Al-Rejaie; Tapan Behl; Gaber El-Saber Batiha; Mohamed A El-Mokhtar; Helal F Hetta

doi:10.2147/IDR.S275852

Detection of gyrA and parC Mutations and Prevalence of Plasmid-Mediated Quinolone Resistance Genes in Klebsiella pneumoniae

Infect Drug Resist. 2021 Feb 12:14:555-563. doi: 10.2147/IDR.S275852. eCollection 2021.

Authors

Affiliations

¹ Branch of Biotechnology, Department of Biology, College of Science, University of Mustansiriyah, Baghdad, Iraq.
² Faculty of Science & Engineering, School of Engineering, University of Plymouth, Plymouth, PL4 8AA, UK.
³ Botany Department, Faculty of Science, Suez Canal University, Ismailia, 41522, Egypt.
⁴ Department of Bacteriology, Immunology and Mycology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt.
⁵ Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.
⁶ Chitkara College of Pharmacy, Chitkara University, Rajpura, Punjab, India.
⁷ Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicines, Damanhour University, Damanhour, 22511, Egypt.
⁸ Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut, 71515, Egypt.
⁹ Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.

Abstract

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; PMQR; quinolones resistance gene.