Antifungal susceptibility testing method for resource constrained laboratories.
OBJECTIVE
In resource-constrained laboratories of developing countries determination of antifungal susceptibility testing by NCCLS/CLSI method is not always feasible. We describe herein a simple yet comparable method for antifungal susceptibility testing.


METHODS
Reference MICs of 72 fungal isolates including two quality control strains were determined by NCCLS/CLSI methods against fluconazole, itraconazole, voriconazole, amphotericin B and cancidas. Dermatophytes were also tested against terbinafine. Subsequently, on selection of optimum conditions, MIC was determined for all the fungal isolates by semisolid antifungal agar susceptibility method in Brain heart infusion broth supplemented with 0.5% agar (BHIA) without oil overlay and results were compared with those obtained by reference NCCLS/CLSI methods.


RESULTS
Comparable results were obtained by NCCLS/CLSI and semisolid agar susceptibility (SAAS) methods against quality control strains. MICs for 72 isolates did not differ by more than one dilution for all drugs by SAAS.


CONCLUSIONS
SAAS using BHIA without oil overlay provides a simple and reproducible method for obtaining MICs against yeast, filamentous fungi and dermatophytes in resource-constrained laboratories.
Khan
S
S
Department of Infectious Diseases, Ranbaxy Research Laboratories, Gurgaon - 122 001, Haryana, India. seema.khan@ranbaxy.com
Singhal
S
S
Mathur
T
T
Upadhyay
D J
DJ
Rattan
A
A
D000935:Antifungal Agents / Q000494:pharmacology*; D003470:Culture Media; D005658:Fungi / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests / Q000191:economics* / Q000379:methods* / Q000592:standards
D000935:Antifungal Agents; D003470:Culture Media