Reliability of the WIDERYST susceptibility testing system for detection of in vitro antifungal resistance in yeasts.
This study evaluated the WIDERYST system, a commercially available computer-assisted image-processing device for the antifungal susceptibility testing of yeasts. A collection of 90 clinical isolates selected to represent ranges of susceptibilities in vitro as broad as possible was tested. An evaluation compared the results obtained by the new system with those achieved by both the Clinical and Laboratory Standards Institute (CLSI) microdilution reference procedure and the antifungal susceptibility standard of the European Committee for Antimicrobial Susceptibility Testing (EUCAST). Overall, the agreement and the correlation index between results obtained by the EUCAST method and the WIDERYST system were 89% and 0.84 (P < 0.01), respectively, and agreement and correlation index between data obtained by the CLSI procedure and the WIDERYST system were 90% and 0.86 (P < 0.01), respectively. The system was able to detect amphotericin B-resistant isolates. All Candida sp. isolates with resistance in vitro to azole agents were detected as well. The system misclassified some isolates belonging to the slowly growing genera Dipodascus and Pichia. A total of 2.7% very major errors were detected for fluconazole. The WIDERYST system is an alternative to reference procedures for antifungal susceptibility testing of clinical isolates of yeasts, particularly for Candida and Cryptococcus species.
Cuenca-Estrella
Manuel
M
Servicio de Micología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra Majadahonda-Pozuelo Km 2, 28220 Majadahonda Madrid, Spain. mcuenca-estrella@isciii.es
Gomez-Lopez
Alicia
A
Gutierrez
M Olga
MO
Buitrago
M Jose
MJ
Rodriguez-Tudela
Juan L
JL
D000666:Amphotericin B / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology*; D001393:Azoles / Q000494:pharmacology; D002175:Candida / Q000145:classification / Q000187:drug effects; D003470:Culture Media; D025141:Drug Resistance, Fungal; D005658:Fungi / Q000145:classification / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods* / Q000592:standards; D009181:Mycoses / Q000382:microbiology; D015203:Reproducibility of Results; D015003:Yeasts / Q000145:classification / Q000187:drug effects
D000935:Antifungal Agents; D001393:Azoles; D003470:Culture Media; D000666:Amphotericin B