Prevalence of Colistin Resistance in Klebsiella pneumoniae Isolated from a Tertiary Care Hospital in Bangladesh and Molecular Characterization of Colistin Resistance Genes among Them by Polymerase Chain Reaction and Sequencing.

Resistance to colistin, the last resort of treatment for multidrug resistant organisms has increased now-a-days. This cross-sectional study was conducted in the Department of Microbiology of Dhaka Medical College, Dhaka, Bangladesh, from July 2016 to June 2017 and was designed to investigate the colistin resistance profile along with the genetic background of colistin resistance among Klebsiella pneumoniae in a tertiary care hospital in Bangladesh. K. pneumoniae was detected by colony morphology on culture media and various biochemical tests. Agar dilution method was used to determine MIC of colistin. PCR was done for detection of colistin resistance genes and sequencing of the amplified mgr B gene products was done. Total 75(23.73%) K. pneumoniae were isolated. Among the isolated K. pneumoniae, 8(10.67%) were resistant to colistin. MIC of colistin of resistant isolates ranged from ≥64µg/ml to ≤4µg/ml. Out of 8 colistin resistant K. pneumoniae, 4(50.00%) were positive for mgr B gene and 3(37.50%) were positive for pho Q gene. Colistin resistance in K. pneumoniae is increasing in Bangladesh, which is very alarming and we should give importance on standard guideline of antimicrobials use.