Evaluation of Vitek2 and Colistin broth disk elution test in comparison with Micro broth dilution for Susceptibility testing of Colistin among Carbapenem Resistant Enterobacterales.

Abstract

Colistin is the last expedient for treating the infections caused by Carbapenem resistant Enterobacter ales (CRE).
Expanding usage of colistin as led to development of Colistin resistance. This urges for a need of reliable and accurate
testing method that can be adopted as routine for susceptibility testing of Colistin. The innate cationic property of
colistin molecules is associated with complexities. Hence evaluation of testing method is needed for detection of colistin
resistance. Present study is done to evaluate the results yielding from Vitek2 and CBDE in comparison with rBMD. About
200 CRE isolated from clinical specimens were tested, results of Vitek2, CBDE was compared with rBMD. In comparison
with BMD Categorical agreement (CA) of Vitec 2 was 83% with major error of 17% .CA of CBDE was 99% with 1% of very
major error. Since the resistance to colistin is increasing accurate reporting of Colistin MIC by a validated method becomes
important. So, we would recommend CBDE for routine testing of Colistin susceptibility.