Evaluation of the etest method using Mueller-Hinton agar with glucose and methylene blue for determining amphotericin B MICs for 4,936 clinical isolates of Candida species.
The performance of the Etest using Mueller-Hinton agar supplemented with glucose (2%) and methylene blue (0.5 microg/ml) (MH-GMB) for amphotericin B susceptibility testing of 4,936 isolates of Candida spp. was assessed against that of Etest using RPMI agar with 2% glucose (RPG). MICs were determined by Etest in both media for all 4,936 isolates and were read after incubation for 48 h at 35 degrees C. The Candida isolates included C. albicans (n = 2,728), C. glabrata (n = 722), C. parapsilosis (n = 666), C. tropicalis (n = 528), C. krusei (n = 143), C. lusitaniae (n = 54), C. guilliermondii (n = 39), C. pelliculosa (n = 17), C. kefyr (n = 15), C. rugosa (n = 11), C. dubliniensis (n = 5), C. zeylanoides (n = 4), C. lipolytica (n = 3), and C. famata (n = 1). The Etest results with MH-GMB correlated well with those with RPG. Overall agreement was 92.9%, and agreements for individual species were as follows: C. lusitaniae, 98.1%; C. albicans, 95.1%; C. glabrata, 94.3%; C. krusei, 91.6%; C. parapsilosis, 86.6%; and C. tropicalis, 86.4%. The Etest method using MH-GMB appears to be a useful method for determining amphotericin B susceptibilities of Candida species.
Pfaller
M A
MA
Department of Pathology, Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa, USA. michael-pfaller@uiowa.edu
Boyken
L
L
Messer
S A
SA
Tendolkar
S
S
Hollis
R J
RJ
Diekema
D J
DJ
D000362:Agar; D000666:Amphotericin B / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000145:classification / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D002177:Candidiasis / Q000382:microbiology; D003470:Culture Media; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008751:Methylene Blue / Q000378:metabolism*; D008826:Microbial Sensitivity Tests / Q000379:methods
D000935:Antifungal Agents; D003470:Culture Media; D000666:Amphotericin B; D000362:Agar; D005947:Glucose; D008751:Methylene Blue