Abstract :
Background: Gram-negative bacterial infections that are resistant to carbapenems are a serious clinical problem. The only effective drugs against them are still tigecycline and colistin. In fact, polymyxin E, also known as colistin, has been regarded as a "last resort" antibiotic. But in recent years, colistin resistance has increased globally, significantly reducing treatment options and highlighting the significance of accurate colistin testing methods to support appropriate therapeutic decision-making.
Materials and Methods: The primary goal of the study is to compare the effectiveness of E-test and Vitek 2 for colistin sensitivity testing to the conventional microbroth dilution method using 120 clinical isolates of Klebsiella pnuemoniae and Acinetobacter baumannii that are resistant to carbapenem over the course of a year, isolated from January to December 2019.
Results: In comparison to Vitek-2, the results indicated that brothmicro dilution and E-test produced the narrowest range of colistin MICs. After comparing the E-test’s errors and overall agreement with BMD, 100% of the Essential Agreement, 94.27% of the Categorical Agreement, and 5.72% of the Very Major Errors with no Major Errors were found. Comparing Vitek-2 with BMD, similar results were found: 1.66% MEs, 98.32% CAs, 80.99% EAs, and no VMEs.
Conclusion: As a result, it was determined that, in contrast to Vitek-2, MBD and E-test had distinct MICs, making them appropriate for determining colistin MIC. It will take more research on automated systems to standardize colistin susceptibility testing procedures, particularly for and K. pnuemoniae and A. baumannii.
Keyword :
Broth microdilution, Carbapenem, Colistin, E- test, Vitek 2, Acinetobacter, Klebsiella.