Evaluation of the "Dip Effect" Phenomenon in Antifungal Susceptibility Testing of Candida spp. against Echinocandins by Use of Gradient Concentration Strips.
The "dip effect" phenomenon complicates antifungal susceptibility testing with gradient concentration strips. Of 60 Candida isolates tested with the three echinocandins, this phenomenon was observed only for caspofungin with most (>90%) Candida albicans, Candida glabrata, and Candida tropicalis isolates and for isolates with CLSI MICs of ≤0.25 mg/liter. In order to facilitate MIC determination, a practical approach was developed using the inhibition zones at 32, 8, 2, and 1 mg/liter, increasing the agreement with the CLSI method >86%.
Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
Maria
M
Siopi
Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
Marilena
M
Tsala
Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
Nikolaos
N
Siafakas
Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
Loukia
L
Zerva
Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece jmeletiadis@med.uoa.gr.
Joseph
J
Meletiadis
D000935:Antifungal Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects* / Q000302:isolation & purification; D041221:Candida glabrata / Q000187:drug effects* / Q000302:isolation & purification; D041022:Candida tropicalis / Q000187:drug effects* / Q000302:isolation & purification; D002177:Candidiasis / Q000188:drug therapy / Q000382:microbiology; D025141:Drug Resistance, Fungal; D054714:Echinocandins / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests
D000935:Antifungal Agents; D054714:Echinocandins