The Evaluation of Efflux Pump Genes norA, norB and norC Related to Fluoroquinolones Resistance in Staphylococcus aureus Strains Isolated from Blood Infection

Fatemeh Dalir; Abbas Morovvati; Ali Javadi; Hamed Afkhami; Mansoor Khaledi; Javad Fathi; Zeinab Mohsenipour; Ashkan Dirbaziyan; Mohsen Zargar

doi:10.18502/jabs.v13i1.12079

Fatemeh Dalir Department of Microbiology, Qom Branch, Islamic Azad University, Qom, Iran
Abbas Morovvati Department of Microbiology, Qom Branch, Islamic Azad University, Qom, Iran
Ali Javadi Department of Medical Science, Qom Branch, Islamic Azad University, Qom, Iran
Hamed Afkhami Department of Microbiology, School of Medicine, Shahed University, Tehran, Iran
Mansoor Khaledi Department of Microbiology, School of Medicine, Shahed University, Tehran, Iran
Javad Fathi Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Zeinab Mohsenipour Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Ashkan Dirbaziyan Department of Microbiology, Qom Branch, Islamic Azad University, Qom, Iran
Mohsen Zargar Department of Microbiology, Qom Branch, Islamic Azad University, Qom, Iran

DOI: https://doi.org/10.18502/jabs.v13i1.12079

Keywords: Staphylococcus aureus, Blood infection, Bacterial drug-resistance, Efflux pump

Abstract

Background & Objective: Recently, ciprofloxacin resistance in Staphylococcus aureus strains, due to efflux pumps, has become a significant challenge. Therefore, this study was performed to evaluate the frequency of norA, norB, and norC efflux pump genes and their roles in resistance to ciprofloxacin in clinical isolates of S. aureus.

Materials & Methods: A total of one hundred clinical blood samples were collected from patient in Qom hospitals and S. aureus isolates were identified by standard microbiological tests. Antimicrobial susceptibility patterns were determined by the disk diffusion method using CLSI guidelines. Subsequently, the presence of norA, norB, and norC efflux pump genes in ciprofloxacin isolates was detected using the PCR method.

Results: Among one hundred clinical samples, 36 S. aureus isolates were recovered and the results of antibiotic susceptibility tests showed that twenty of them were resistant to ciprofloxacin. 15 isolates were resistant to norfloxacin and one isolate was resistant to ofloxacin. Moreover, the norA, norB, and norC genes were found in 58%, 30%, and 41% of ciprofloxacin-resistant isolates, respectively.

Conclusion: Based on the results of this study, norA, norB, and norC efflux pumps may play a significant role in the development of resistance to ciprofloxacin in clinical isolates of S. aureus. Detecting these genes may prove useful in suggesting an effective treatment model for infections caused by S. aureus.