Colistin Susceptibility among Carbapenem Resistant Klebsiella pneumoniae Isolated from Menoufia University Hospitals

Abstract

Background: Infections by CRKp represents a major health problem. Carbapenemases have been frequently reported in CRKp. Limited antimicrobials are still effective for CRKp like tigecycline, ceftazidime/avibactam, as well, polymyxins including colistin. With the increased use of colistin, Col R k. pneumoniae carbapenemase (KpC)producing isolates are documented worldwide. Objectives: The aim of the current study is to investigate carbapenemases and to determine colistin susceptibility and mcr genes among CRKp. Material and methods: k. pneumoniae were identified by conventional methods and API20E. Carbapenem and colistin resistance were screened by disc diffusion method. Confirmatory combined mCIM/eCIM testing was used for carbapenemases detection. BMD and CBDE tests were used for colistin susceptibility detection. Multiplex PCRs were done for carbapenemases genes (blaNDM-1, blaOXA48, blaIMP blaVIM, blaKPC) and colistin resistance genes (mcr1, 2, 3, 4 and 5 genes) detection. Results: Out of CRKp, 68.9% were positive carbapenemases by mCIM/eCIM testing, 33.3% of them were MBLs and 66.7% were serine carbapenemases. the most frequent carbapenemases genes were blaKPC and blaOXA-48. About 16.3% of CRKp were colistin resistant by BMD test. There was fair agreement of CBDE test in relation to BMD for colistin susceptibility detection. The mcr1 gene was detected in 9.1% of CRKp. Conclusions: The increase detection of carbapenemases and colistin resistance among k. pneumoniae isolates obligate us for efficient use of prevention and control protocols to decrease the multidrug resistance in hospital and community environments.