• Investigation of the frequency of resistance to Fluoroquinolones and the presence of PMQR genes (qnrA, qnrB and qnrS) in Klebsiella pneumoniae isolated in Tabriz hospitals.
  • Rahim peyghami,1,* Mehdi Ghiamirad*,2
    1. M.Sc. student of Microbiology in Mizan Higher Education Institute
    2. *Department of Microbiology, Faculty of science, Ahar Branch Islamic Azad University, Ahar -Iran


  • Introduction: Klebsiella pneumoniae is one of the important clinical pathogens and responsible for some nosocomial infections; especially pneumonia, septicemia, and urinary tract infection (UTI). Fluoroquinolones are highly effective antibiotics with many advantageous pharmacokinetic properties including high oral bioavailability, large volume of distribution, and broad-spectrum antimicrobial activity. With widespread use, antimicrobial resistance to fluoroquinolones has grown Multiple drug resistance among Klebsiella pneumoniae isolates is one of the most important challenges for treating of such infections worldwide. This study was conducted with the aim of determining the resistance of Klebsiella pneumoniae isolates collected from Tabriz hospitals against fluoroquinolone antibiotics and the presence of the PMQR genes (qnrA, qnrB and qnrS) in them.
  • Methods: In this cross-sectional descriptive study, 250 gram-negative bacterial isolates obtained from patients Sina, and Al-Zahra hospitals in Tabriz were studied. Samples were processed for microbial and biochemical characterization. Antibiotic susceptibility test was carried out to Commonly used antibiotics in the treatment of infections caused by gram-negative bacteria by using disc diffusion method. The distribution of Plasmid-Mediated Quinolone Resistance (PMQR), qnrA, qnrB, qnrS in isolates were detected by PCR.
  • Results: 97 isolates of Klebsiella pneumoniae were identified by biochemical tests. The highest antibiotic resistance of Klebsiella pneumoniae isolates to Ampicillin with 100% and the lowest resistance with 11% to Ciprofloxacin was observed. 29% of the isolates showed showed multiple drug resistance (MDR). Resistance to nalidixic acid was observed in 40% isolates and to ciprofloxacin in 11% isolates. qnrb gene was observed in 37% of isolates. qnrA was detected in 14% of isolates. qnrS Gene no detected in isolates.
  • Conclusion: High resistance to most of the studied antibiotics, especially fluoroquinolones, in the studied isolates should be consider as a vital factor and must rigorously take into account. Antibiogram and selection of appropriate antibiotic is recommended before starting treatment.
  • Keywords: Antibiotic resistance pattern; Klebsiella pneumonia, qnrb, qnrA,qnrS genes