Prevalence of colistin resistance and its molecular mechanisms in clinical isolates of Klebsiella pneumoniae obtained from hospitalized patients in teaching hospitals in Isfahan, Iran.

Background and Aim : The current study was performed to investigate the prevalence of colistin resistance and its molecular mechanisms in clinical isolates of Klebsiella pneumoniae obtained from hospitalized patients in teaching hospitals in Isfahan, Iran.Methods : This cross-sectional study was performed during the ۲۰۱۹-۲۰۲۰ year at several teaching hospitals in Isfahan, Iran. The minimal inhibitory concentration (MIC) of colistin was determined by the E-test strips. Also, PCR assay was carried out to detect genes encoding resistance to colistin, including mcr-۱, mcr-۲, pmrA, pmrB, crrB.Results : In the present study, a total of ۷۹ strains of multidrug-resistant K. pneumoniae were isolated. Of these, ۳۵ colistin-resistant clinical K. pneumoniae isolates were obtained from hospitalized patients in Isfahan. All colistin-resistant isolates were classified as extensively drug-resistant (XDR). PCR results on K. pneumoniae isolates showed that mcr-۱ and mcr-۲ genes were not detected in any of the strains, while, ۸ isolates (۱۰.۱%) contained pmrA gene and ۸ isolates (۱۰.۱%) also carried pmrB gene. In addition, the frequency of crrB gene among our isolates was ۳.۸%. Conclusion : Due to the fact that the last line of treatment for infections associated with K. pneumoniae is colistin, therefore, increasing resistance to this antibiotic causes many concerns and problems in the treatment of patients. Detection of colistin-resistant strains and reporting of occurrence of genes associated with this resistance can greatly help in the treatment of diseases.

کلیدواژه ها:

Klebsiella pneumoniae ، colistin ، MDR ، XDR