Diagnosis and Treatment

Molecular diagnosis of disseminated candidiasis has been reviewed recently (Bretagne & Costa, 2005). Methods for detecting and quantifying C. albicans in biological samples include a real-time PCR for the mannoprotein 65 (MP65) gene, which demonstrated specificity for C. albicans and was highly sensitive (l genome for sera and urine and 10 genomes for blood) (Arancia et al., 2006). Nucleic acid sequence-based amplification has been shown to improve detection rates of C. albicans in blood cultures (Borst et al., 2001). A multianalyte profiling system has also been developed, where DNA probes specific for six medically important Candida species are linked to beads. Biotinylated PCR products from samples were then hybridised to the probes and bound amplicons detected fluorometrically (Das et al., 2006). It is suggested that a sample could be processed and analysed within 1 h post-PCR amplification.

Other PCR methods based upon rRNA sequences to identify Candida species have also been devised (Evertsson et al., 2000; Goldenberg et al., 2005; Leinberger et al., 2005; Nazzal et al., 2005; Klingspor & Jalal, 2006). However, problems are found with DNA extraction from biological samples, such as whole blood (Fredricks et al., 2005). This may be less of a problem if plasma is used, since free fungal DNA has been detected in plasma samples (Kasai et al., 2006). The PCR methods are designed to be pan-fungal, amplifying DNA from a number of fungal species, with the species identified either through use of hemi-nested PCR (Nazzal et al., 2005), through fungal-specific probes (Evertsson et al., 2000), or by highresolution separation of PCR products by HPLC (Goldenberg et al., 2005). The PCR products have also been hybridised to a DNA microarray designed to allow species identification (Leinberger et al., 2005). An attempt is being been made to produce a consensus PCR test for use in detection of systemic fungal infections, including those caused by C. albicans (White et al., 2005, 2006). These molecular methods are designed to reduce the time taken to identify the fungus causing a systemic infection. This is especially important as it has been demonstrated, both in a mouse model and in patients, that any delay in the time taken to initiate antifungal therapy significantly affects mortality (MacCallum & Odds, 2004; Morrell et al., 2005; Garey et al., 2006).

An immunoassay has also been developed and marketed (Unimedi Candida monotest) which detects serum mannan antigens. This is highly sensitive and specific and is a promising tool for diagnosis, especially as the test can be carried out in 1 h (Fujita et al., 2006). The optimisation of these tests and development of new molecular tests should, hopefully, improve diagnosis of systemic fungal infection.

A huge amount of literature describes the antifungal agents currently, and soon to be, available for the treatment of systemic C. albicans infections, with a number of reviews recently published (Potter, 2005; Aperis et al., 2006; Chamilos & Kontoyiannis, 2006; Deck & Guglielmo, 2006; Enoch et al., 2006; Kauffman, 2006; Munoz et al., 2006; Spellberg et al., 2006; Turner et al., 2006).

One of the exciting areas of treatment of systemic C. albicans infection involves use of antibody therapy. Mice immunised with a specific epitope of C. albicans Hsp90 were found to have significantly lower kidney burdens compared to control mice (Wang et al., 2006a). An antibody against this fungal Hsp90 (Mycograb) has since been shown to reduce fungal counts and improve mortality rates in invasive candidiasis when used in combination with amphotericin B (compared to ampho-tericin alone) (Matthews et al., 2003; Pachl et al., 2006). It is suggested that this, and other antibody therapies, are promising treatments for the future.

How To Cure Yeast Infection

How To Cure Yeast Infection

Now if this is what you want, you’ve made a great decision to get and read this book. “How To Cure Yeast Infection” is a practical book that will open your eyes to the facts about yeast infection and educate you on how you can calmly test (diagnose) and treat yeast infection at home.

Get My Free Ebook


Post a comment