dissemination pattern of multidrug resistant carbapenemase producing klebsiella pneumoniae isolates using pulsed-field gel electrophoresis in southwestern iran

Zahra Hashemizadeh,1 Zahra Hosseinzadeh,2 Negar Azimzadeh,3 Mohammad Motamedifar1,4 1Department of Bacteriology and Virology, Shiraz University of Medical Sciences, Shiraz, Iran; 2Basic Sciences in Infectious Diseases Research Center, Shiraz University of Medical Sciences, Shiraz, Iran; 3Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran; 4Shiraz HIV/Aids Research Center, Institute of Health, Shiraz University of Medical Sciences, Shiraz, IranCorrespondence: Mohammad MotamedifarDepartment of Bacteriology and Virology, Shiraz University of Medical Science, Shiraz, IranTel/Fax +98 71 3230 4356Email motamedm@sums.ac.irBackground: Klebsiella pneumoniae is an important cause of healthcare-associated infection. Carbapenemases have increasingly been reported in Enterobacteriaceae, especially in K. pneumoniae.Propose: The objective of this study was to determine antibiotic resistance patterns, and the molecular epidemiology of multidrug resistant K. pneumoniae isolates, obtained from hospitalized patients in Shiraz, Iran.Methods: In this study, 60 K. pneumoniaeisolates were collected from Nemazee and Faghihi referral hospitals. Antibiotic susceptibility testing and MIC were performed by disk diffusion test and Epsilometer (E)-test strips, respectively. Carbapenemase genes were identified by polymerase chain reaction and sequencing. Then, clonal relationships were analyzed, using PFGE.Results: Thirty-three out of 60 K. pneumoniae isolates were resistant to carbapenems. Among the isolates, 86.6% were multidrug resistant (MDR). Polymyxin B (18.3%) and tigecycline (23.3%) were shown to be the most active agents against K. pneumoniae isolates. In our study, the high prevalence of blaNDM (45%) and blaOXA-48 (10%) was detected.Conclusion: The results of this study revealed the widespread carbapenemase gene between different wards in hospitals as a risk factor for treatment options. PFGE analysis showed 11 clusters and 3 singletons based on an 80% similarity level. Also, PFGE analysis showed that there were similar genetic patterns among K. pneumoniae isolates and these patterns were responsible for the distribution of infection in hospitals.Keywords: Klebsiella pneumoniae, pulsed-field gel electrophoresis, PFGE, carbapenemases