Comparison between two culture media for in vitro evaluation of antifungal susceptibility of the Sporothrix schenckii complex.
BACKGROUND
The standard methodology for determining the antifungal sensitivity against the Sporothrix schenckii complex recommends the use of the 1640 Roswell Park Memorial Institute culture medium (RPMI) buffered with morpholinepropanolsulfonic acid (MOPS). However, while this is a high-cost medium which requires a laborious implementation and sterilization by filtration, the Sabouraud dextrose broth is a low-cost medium, widely used in mycology, sterilized by autoclave.


OBJECTIVE
To evaluate the performance of the Sabouraud dextrose broth culture medium as a substitute for the RPMI 1640-MOPS in determining the antifungal sensitivity of S. schenckii.


METHODS
Forty-eight clinical isolates were evaluated against five antifungal agents: itraconazole, ketoconazole, fluconazole, amphotericin B and terbinafine, using the method of broth microdilution advocated by the M38-A2 protocol of the Clinical and Laboratory Standards Institute.


RESULTS
There were no significant differences between the Minimum Inhibitory Concentrations obtained in the two culture media for all the antifungals, with the exception of the amphotericin B. Regarding this drug, the Minimum Inhibitory Concentration range obtained were wider for the Sabouraud dextrose broth than for the Roswell Park Memorial Institute morpholinepropanelsulfonic acid.


CONCLUSIONS
The Sabouraud dextrose broth showed potential to be used in the in vitro evaluation of the S. schenckii complex antifungal activity.
Post-Graduation Program in Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. cheila.dos@gmail.com
Cheila Denise Ottonelli
CD
Stopiglia
Daiane Péres
DP
Marchese
Daiane
D
Heidrich
Julia Medeiros
JM
Sorrentino
Fabiane Jamono
FJ
Vieira
Maria Lúcia
ML
Scroferneker
D000666:Amphotericin B / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology*; D003470:Culture Media / Q000737:chemistry* / Q000191:economics; D015725:Fluconazole / Q000494:pharmacology; D005947:Glucose / Q000191:economics / Q000494:pharmacology; D006801:Humans; D017964:Itraconazole / Q000494:pharmacology; D007654:Ketoconazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests / Q000191:economics / Q000379:methods; D009281:Naphthalenes / Q000494:pharmacology; D013175:Sporothrix / Q000187:drug effects*; D000077291:Terbinafine
D000935:Antifungal Agents; D003470:Culture Media; D009281:Naphthalenes; D017964:Itraconazole; D000666:Amphotericin B; D015725:Fluconazole; D000077291:Terbinafine; D005947:Glucose; D007654:Ketoconazole