Comparative study of agar diffusion test and the NCCLS macrobroth method for in vitro susceptibility testing of Candida spp.
We performed a prospective double-blind study to evaluate the correlation between inhibition zones obtained by a disk-diffusion test, using Neo-sensitabs of fluconazole (Rosco Diagnostica), and the MICs generated by the NCCLS macrobroth dilution assay. Eighty clinical isolates, representing 5 of the clinically relevant species of Candida, were tested simultaneously by both methods. A clear inverse correlation was found between the results obtained by both tests (r = -0.69). In addition, there was high degree of agreement between methods in the identification of susceptible isolates. However, the resistance definition by disk-diffusion test had a positive predictive value of only 17%. Our data support the hypothesis that Rosco Fluconazole Neo-sensitabs have potential as a screening test for the identification of Candida isolates susceptible to fluconazole. Resistant isolates should be further investigated by standardized broth procedures.
Soni
L M
LM
Division of Infectious Diseases, Escola Paulista de Medicina-UNIFESP, Brazil.
Burattini
M N
MN
Pignatari
A C
AC
Gompertz
O F
OF
Colombo
A L
AL
D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects*; D002177:Candidiasis / Q000382:microbiology*; D004311:Double-Blind Method; D015725:Fluconazole / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods* / Q000592:standards; D011446:Prospective Studies; D011786:Quality Control; D012016:Reference Values
D000935:Antifungal Agents; D015725:Fluconazole