Author/Authors :
OSTADHADI, SATTAR Brain and Spinal Cord Injury Research Center - Neuroscience Institute - Tehran University of Medical Sciences, Tehran, Iran , RASHIDI, MOHSEN Department of Pharmacology - School of Medicine - Shaheed Beheshti University of Medical Sciences, Tehran, Iran , ZOLFAGHARI, SAMIRA Department of Tissue Engineering and Applied Cell Sciences - School of Advanced Technologies in Medicine - Iran University of Medical Sciences, Tehran, Iran , MARADENEH, JALAL Department of Microbiology - School of Medicine - Gonabad University of Medical Sciences, Gonabad, Iran , NIKOUI, VAHID Razi Drug Research Center - Iran University of Medical Sciences, Tehran, Iran
Abstract :
Appearance of bacteria resistant to antibacterial agents puts physicians in trouble and threatens the
health of the world. The rapid development of bacterial resistance in Escherichia coli to ciprofloxacin
makes difficult the treatment of infectious diseases. So, detection of the locations of possible mutations in
gyrase A gene (gyrA) in these mutants is very important to determine the mechanism of this resistance.
In the present study, ciprofloxacin-resistant mutants were isolated from medium containing ciprofloxacin.
Polymerase chain reaction (PCR) was used to amplify the gyrA gene in these mutants and DNA
sequencing was used to determine the location of mutation in this gene. Results showed that the most of
ciprofloxacin-resistant mutants contain mutations in quinolone resistance- determining region (QRDR) of
A subunit of DNA gyrase and specially at serine 83. However, mutations outside of this region were also
found at tyrosine 50 and alanine 119. In conclusion, this study confirms that mutation in serine 83 of
QRDR in A subunit of DNA gyrase is the main cause of resistance to ciprofloxacin in E. coli.
Keywords :
Escherichia coli , Ciprofloxacin , DNA gyrase , Quinolone resistance , Mutation
