Emergence of extensively drug-resistant and colistin resistance Klebsiella pneumoniae Isolated from hospitalized patients in Isfahan, Iran

Background and Aim : The current study was performed to investigate the antibiotic resistance pattern, 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. All K. pneumoniae isolates were screened against ۱۴ antimicrobial agents based on standard disk diffusion method. Moreover, the minimal inhibitory concentration (MIC) of colistin was determined by the E-test strips Results : In the present study, a total of ۷۹ strains of multidrug-resistant K. pneumoniae were isolated. Among the ۷۹ K. pneumoniae isolates, ۵۲ (۶۵.۸%) were obtained from females and ۲۷ (۳۴.۲%) from males. Most of K. pneumoniae strains were isolated from patients between ۴۶-۶۰ years old. Of these, ۳۵ colistin-resistant clinical K. pneumoniae isolates were obtained. These isolates were resistant to all classes of antibiotics, including colistin, and were classified as extensively drug-resistant (XDR). Antibiotic susceptibility pattern showed a high rate of antibiotic resistance to ceftazidime (۹۴.۹%) followed by cefepime and aztreonam (۹۱.۱%), while, the lowest resistance rate was observed against tigecycline (۲.۵%).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 can greatly help in the treatment of diseases. Also in our study, a low level of resistance to tigecycline was observed, which can be used to treat patients.

Keywords:

Klebsiella pneumoniae , colistin , MDR , XDR