Like weeds in a lawn, pathogenic fungi and yeasts (single-celled fungi) can invade and overtake our bodies. In people with healthy immune systems, cells called macrophages and neutrophils engulf these pathogens, nipping them in the bud. But when the immune system is weakened by disease or drugs, fungi much like weeds in your garden can grow unchecked.
For example, when the neutrophil cell count is low, an invasion of the common yeast Candida albicans can cause a systemic infection. The result can be an overgrowth of the yeast in various organs and possibly death. In such cases, physicians often turn to anti-fungal drugs to keep the yeast under control. But over time, yeasts and fungi can develop resistance to the treatments, forcing medical researchers to devise more potent drugs. Meanwhile, the patient's health hangs in the balance.
From Harmless to Harmful
For millennia, yeasts and fungi have enjoyed relatively good relations with humans. Despite their abundance they appear on plant leaves and flowers, soil, salt water, baked goods and beer, as well as in our gastrointestinal tracts and skin surfaces very few yeasts and fungi trigger disease in healthy people. Present in about half of us, the most common fungal pathogen, Candida albicans, can cause easily treatable ailments such as vaginitis, diaper rash and oral thrush. But according to recent reports, yeasts and fungi are impacting some people much more severely: An increasing number of hospital patients with c
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Contact: Kelli Whitlock
newsroom@wi.mit.edu
617-258-5183
Whitehead Institute for Biomedical Research
13-May-2003