In Vitro Antifungal Susceptibility Testing

Abstract

With the rising frequency of fungal infections, as well as increasing reports of resistance to antifungal agents, it is imperative that clinically applicable antifungal susceptibility testing be available. In 1997 the National Committee for Clinical Laboratory Standards published standard guidelines for antifungal susceptibility testing of Candida sp and Cryptococcus neoformans with amphotericin B, flucytosine, fluconazole, itraconazole, and ketoconazole. Although the methods are standard, they are time consuming, can be difficult to interpret, and are approved only for testing limited organisms and drugs. Modifications to the methods and alternative approaches have been proposed to make these tests more convenient and efficient, applicable to a greater number of species, and appropriate for performing in the clinical laboratory.

Antimicrobial activity of bergenin from Endopleura uchi (Huber) Cuatrec

“…The bacteria were cultured on nutrient Mueller-Hinton agar slant (DIFCO, Detroit, MI), while fungi on RPMI 1640 standard cell culture (Sigma Chemicals, St. Louis, MO) were buffered with a 0.165 M MOPS buffer and fortified with 20 g of glucose/liter and 1.5% agar (Hoffman & Pfaller, 2001). Antimicrobial activity of bergenin was evaluated by the agar-well diffusion method.…”

Antifungal Susceptibility Survey of 2,000 Bloodstream Candida Isolates in the United States

“…Antifungal susceptibility testing has become an important tool in the management of patients with invasive candidiasis, since both in vitro resistance and toxicity issues must be considered when selecting an antifungal agent (5,10,15,30,33). The NCCLS has developed the standardized and reproducible M27-A2 method for testing yeasts (18).…”

Clinical Evaluation of a Frozen Commercially Prepared Microdilution Panel for Antifungal Susceptibility Testing of Seven Antifungal Agents, Including the New Triazoles Posaconazole, Ravuconazole, and Voriconazole

“…has been established since 1997 (5), commercially available broth microdilution panels providing full-range MICs for both established and newly introduced antifungal agents have been slow to develop. Several products providing broth microdilution testing of a limited number of antifungal agents, usually in a limited-range or breakpoint format, have been introduced in Europe, but in most instances their performance has been found to compare poorly with that of the NCCLS reference method (2,11,15).It has been noted that one of the major barriers to the use of antifungal susceptibility testing in clinical practice is the limited availability of test results in a timely fashion (2, 11, 15; S. Presently, Trek Diagnostic Systems (Westlake, Ohio) manufactures custom broth microdilution panels for antifungal susceptibility testing. These panels are available for research purposes in a frozen or dried format either with or without the colorimetric indicator Alamar Blue (7).…”

“…has been established since 1997 (5), commercially available broth microdilution panels providing full-range MICs for both established and newly introduced antifungal agents have been slow to develop. Several products providing broth microdilution testing of a limited number of antifungal agents, usually in a limited-range or breakpoint format, have been introduced in Europe, but in most instances their performance has been found to compare poorly with that of the NCCLS reference method (2,11,15).…”

“…It has been noted that one of the major barriers to the use of antifungal susceptibility testing in clinical practice is the limited availability of test results in a timely fashion (2,11,15 (14,15).…”