Honing the science of anti-fungal treatment
Mar 08 2010
Fungi are a source of large number secondary metabolites, the compounds that are not necessary for growth and reproduction but are produced by the organism to protect them from various onslaughts. An antibiotic is prime example of a secondary metabolite. The aggressive use of antibiotics over time may lead to increase in fungal pathogens. The blind treatment of mycoses leads to excessive use of antifungal drugs and thus can encourage the emergence of drug resistant strains.
In the microbial community present in the human body (“microbiome”), fungi are a minority; of the roughly 1.5 million fungal species, some 200 have been associated with the human body. It includes Candida species (which can cause superficial and systemic infections), moulds (that infect the lung), the basidiomycete fungi (which infect the lung and central nervous system), and the dimorphic human fungal pathogens. Fungi, being the minority microbe, interact with majority microbe, the bacteria; for example, with pathogenic bacteria, probiotic bacteria, and other cohabitants.
The common misconception is that the fungi attack only immune-compromised hosts. But it is good to know that fungal infections also strike healthy people. It is also important to know that, unlike viruses and some bacteria, person-to-person transmission of invasive fungal disease is rare.
A great deal of information about human fungal pathogens is still unknown. Given the increasing incidence of fungal infections, it is important to develop new diagnostics and new types of treatments. One of the problems is the early detection of fungal infected patients. Techniques commonly employed in the detection of fungal diseases include microscopic examination, culturing, and serology. These methods are lengthy and also are still not out of accuracy problems. Other approaches are therefore being developed.
Polymerase Chain Reaction based methods have potential but are still not fully safe. The identification of fungal infections by metabolomics or proteomics has great potential. The molecular biology and ‘omics’ based approaches have the potential to offer new insights and abilities to produce antigens for use in vaccines. But these approaches for the diagnosis of mycoses are in the initial stages of development. Another possibility, says a report of the American Academy of Microbiology, is the use of fungi for allergy control. If fungi’s allergy responses are better understood, this could lead to the development of fungal vaccines for allergy control. New avenues for exploration, according to the report, include: immune enhancement, increment in innate immunity, use of probiotic organisms for enhancing immune response to fungal pathogens, administering strains of fungi with reduced virulence to out-compete virulent strains, delivery of mycoviruses to kill fungal pathogens. It is suggested that the researchers should follow a more cautious approach while dealing with the mycoses as an imperfectly honed antifungal therapy may harm the fungus as well as the unfortunate patient.
The writer is a biotechnologist and ED, Birla Institute of Scientific Research, Jaipur