DOI: 10.36347/sjams.2018.v06i06.054

Pages: 2590-2595

The increasing incidence of clinically significant Candida infections and raise in antifungal resistance among these isolates necessitates routine antifungal susceptibility testing in clinical laboratories. The broth dilution method recommended by Clinical Laboratory Standards Institute (CLSI) is very much labour-intensive to be used regularly in such laboratories. In our study, we have compared two in-vitro antifungal sensitivity testing methods and the concordance between these methods was evaluated. This was a comparative analytical study conducted in the Department of Microbiology. Candida isolates obtained during July-December 2017 from various clinical samples were included in the study. The minimum inhibitory concentration (MIC) of Amphotericin B and Fluconazole was evaluated using the two methods viz. broth microdilution method and modified agar dilution method. The discrepancies between the two methods were noted and inter-test agreement was analyzed using Cohen’s weighted kappa statistic, concordance correlation coefficient and Bland-Altman analysis. A total of 25 Candida isolates obtained during the study period were subjected to the two test methods. Agar dilution method showed a moderate level of agreement with reference broth dilution method when tested for fluconazole as well as amphotericin B. The disagreements were found to be as a result of correctable systematic error i.e greater precison ( 0.9) and lesser accuracy ( 0.5). The trend of systematic error was quantified and with proper adjustments, this can be reduced to a greater extent. Since the clinical laboratory needs reliable and less labour-intensive alternative methods for the determination of the MICs of antifungal agents, we compared these two methods. The findings of this study need to be confirmed with more number of isolates and proposed modifications, to be adopted for regular use in laboratories.