Background & Aims: Klebsiella Pneumonia is a common cause of nosocomial infections including urinary tract, respiratory and wound infections. Several fluoroquinolones resistance mechanisms have been proposed, such as mutations in the topoisomerase IV subunits (ParC and ParE). The aim of this study was to investigate parC mutations in ciprofloxacin resistant isolates of Klebsiella Pneumonia from Guilan province.

Materials & Methods: In this study, forty strains of Klebsiella Pneumonia were isolated from several Rasht and Lahijan hospitals and laboratories then were identified by biochemical tests. Antimicrobial susceptibility to ciprofloxacin, imipenem, amikacin, cefixime, cefotaxime, cephalexin, gentamicin, and nalidixic acid was determined by Kirby-Bauer disk diffusion and MIC methods. Then PCR-sequencing was performed to assess parC mutations in ciprofloxacin resistant isolates.

Results: 15% of isolates were resistant to all eight antibiotics. Thirteen isolates (32.5%) were ciprofloxacin resistance. The most antibiotic resistance percentage was found for Cephalexin (70%) and the lowest resistance percentage was identified for Gentamicin (17.5%). Sequencing analysis showed that three ciprofloxacin resistant isolates had missense mutations L38F and/or E84K in parC gene.

Conclusion: In Guilan province, it seems that parC mutations plays role in developing ciprofloxacin resistance in Klebsiella Pneumonia through change in ciprofloxacin affinity to topoisomerase IV.