Evaluation of Resistance to Fluoroquinolones and Its Relationship whit parC Gene Mutation in Klebsiella pneumoniae Clinical Isolates

 Klebsiella pneumoniae has received attention due to a wide range of diseases and antibiotic resistance.The resistance to fluoroquinolones in gram-negative bacteria is often due to chromosomal mutations in the gyr and par genes. This research aimed at investigating the pattern of fluoroquinolone resistance and its relation with a mutation in the parC gene among clinical isolates of K. Pneumoniae.

In this descriptive-analytical study, 95 K. pneumoniae, after biochemical and molecular diagnosis, were evaluated for resistance to different antibiotics by disk diffusion agar according to CLSI recommendations and screening for ciprofloxacin-resistant isolates. Mutation in the ciprofloxacin resistance determinant region of the parC gene of K. pneumoniae resistant to ciprofloxacin was performed by PCR amplification and then amplified fragment sequencing and finally with the standard bacterial genome sequencing available at NCBI site, became BLAST through online software, Insilico, and Clustalw2.

 The result of the antibiogram showed implies an expansion of MDR bacteria. 3.1% of isolates were resistant to all 13 antibiotics studied and 24.2% were ciprofloxacin-resistant. The highest and lowest percentages of antibiotic resistance were determined for ampicillin and amoxicillin (98.9%) and imipenem (13.6%), respectively. Sequence analysis of the parC gene showed that of 23 isolates resistant to ciprofloxacin, 16 isolates at codon 80 (I80S), one at codon 84 (E84K) were and 3 isolates also had frame-shift mutations.

 Mutations in the parC gene can be one of the major contributors to resistance to fluoroquinolones and increased MDR bacteria and nosocomial infections.