In Vitro Susceptibility Amphotericin B and other polyenes Amphotericin B exerts a fungicidal effect on Cryptococcus neoformans [343]. As with Candida spp., the NCCLS method has difficulty distinguishing amphotericin B-resistant isolates from the susceptible ones. However, modifications of this method, such as the use of Antibiotic Medium 3 supplemented to 2% glucose (AM3) instead of the reference RPMI 1640 medium appear useful [427, 1141, 1379, 1382, 1383, 1835]. Shaking the microplates during incubation also appears helpful [1945]. There are also data indicating that minimum fungicidal concentrations (MFCs) may be better predictors of clinical outcome than MICs [1940]. However, these modifications […]

Overview Although individual isolates of any given species may become resistant to any agent, there are some broad patterns that are useful to know. Here are the patterns for the six most common Candida species. As can be seen, knowledge of the species of the isolate is almost as useful as having an actual measured MIC. For more details on both the utility and limitations of susceptibility testing, please review the paper in which many of these interpretive categories were first proposed [1910]. Polyenes Azoles Other Species AmB Fluco Itra Keto 5-FC C. albicans S S S S S C. […]

In its most general terms, susceptibility testing refers to the idea of mixing the fungus with a drug and seeing what happens. In general, we are interested in determining a minimal concentration of drug that appears likely to inhibit (minimum inhibitory concentration, MIC, µg/ml) or kill (minimum fungicidal concentration, MFC, µg/ml) the fungus. If this level is low enough, then the drug may work against an infection. The approach to testing is different for yeasts and moulds. If you simply want to look at some susceptibility results, please see our searchable N/A(L):susceptibility database or review our summaries of usual susceptibility […]

Introduction Fungal infections have emerged as a significant clinical problem in recent years. Due to the increasing frequency of fungal infections, mycology is today undergoing a true renaissance. Although not fully sufficient yet, we have novel tools for diagnosis. While the conventional methods of cultivation and histopathology remain the gold standards for diagnosis, the progressions in molecular mycological methods have markedly influenced the concept of rapid diagnosis. Therapeutic modalities have also evolved. The development of novel antifungal agents, including agents of entirely new classes, is noteworthy. Finally, the development of the standard in vitro susceptibility testing procedures for yeasts [1623] […]

Diagnosing Fungal Infections Using Histopathology Histopathology remains one of the major tools of diagnosis in mycology. The major advantages of histopathology are speed, low-cost, and the ability to provide a presumptive identification of the infecting fungus, as well as demonstrating the tissue reaction. However, unless special techniques such as immunofluorescence are used, or the infecting fungus possesses unique structures such as spherules, definitive identification of the etiologic agent by histopathology is difficult. Nevertheless, it usually provides essential information before the fungus can be isolated in a mycology laboratory. Furthermore, histopathology is the only way to diagnose infections caused by Loboa […]