Several fungi (including yeasts and filamentous fungi) often cause severe and sometimes life threatening human infections including Candida (especially C. albicans) and Aspergillus. Other fungi which commonly cause human infections include Cryptococcus gattii and neoformans, Histoplasma capsulatum, and Coccidioides imittis and posadasii (Valley Fever)
1. Candida species other than C. albicans- including C. glabrata, parapilopsis, tropicalis and a number of others. Infections of non C. albicans species have been growing rapidly in recent years with many of these species developing virulence factors and antibiotic resistance similar to C. albicans. There have been many recent outbreaks of Candida auris which is resistant to many drugs and has a crude hospital death rate of 30-60%. One study of C. auris from 54 infected patients reported that 93% were resistant to fluconazole, 35% resistant to Amphotericin B, and 7% to echinocanadins. Candida infections can affect non immunocompromised patients.
2. Trichosporon- another common yeast like fungi- frequently colonize the skin and gastro intestinal areas. Invasive infections have mostly occurred in patients with surgery, burns, leukemia, and corticosteroid usage.
3. Saccharomyces or baker’s yeast- can cause serious infection. It is an emerging infection in people with blood cancers. Amphotericin B is considered the drug of choice for Saccharomyces infections.
4. Rhodotorula- another common yeast in food and indoor environment- produce orange colored cultures. Most people infected have blood cancers and/or catheters. Invasive infections have 12 to 20% mortality. Again, often treated with amphotericin B.
5. Malassezia. A common skin fungi- can cause severe systemic infections in neonates and children/ adults with blood cancers, Crohn’s disease or on dialysis. Often treated with amphotericin B and fluconazole.
1. Mucorales—a large group of fungi including Rhizopus, Rhizomucor, Mucor, Lichtheimia, Apophysomyces, Cunninghamella, Saksenaea, Cokeromyces, Actinomucor, and Syncephalastrum. Many of these fungi are common on food and in the environment. Serious infections can involve the lungs, the nose sinuses (where they can enter the brain) and bloodstream. Major risk factors are diabetes, blood cancers, organ and bone marrow transplantation, neutropenia, trauma and burns. Often overdiagnosed or undiagnosed. Invasive infections have high mortality rate which can exceed 50%. Treated with amphotericin B and poscanazole and other anti fungal drugs.
2. Fusarium- fungi common in foods/crops and often seen in the indoor and outdoor environment. Can cause disseminated infections, especially in immunocompromised people. Infections are often airborne. Often resistant to antifungals.
3. Scedosporium and Lomentospora. Found commonly in soil and compost. Most commonly infect immunocompromised patients like cystic fibrosis patients but can also infect immunocompetent people, especially after trauma. Mortality rates are as high as 75% in immunocompromised patients. These fungi are often hard to treat since they have high resistance to most anti-fungal drugs. Infections are often treated with a combination of anti-fungal drugs such as the azole drugs and terbidifine.
4. Paecilomyces- Commonly found in soil and indoors. Cause infections in every organ of the body including skin, lungs, soft tissue, catheter areas and kidneys. Treated with a variety of azole drugs.
5. Penicillium or Talaromyces marneffei. Infections especially common in SE Asia. Most common in HIV+ and immunosuppressed patients. Infections cause fever, weight loss, swollen lymph glands, and breathing problems.
Many other fungi have been reported to cause serious infections in both immunocompetent and immunocompromised hosts including Alternaria, Emmonsia, Magnusiomyces, and over 70 other genera of fungi.
References / Sources
2. Sachin C. Deorukhkar, Santosh Saini, and Stephen Mathew Non-albicans Candida Infection: An Emerging Threat. Interdisciplinary Perspectives on Infectious Diseases Volume 2014 (2014), Article ID 615958, 7 pages
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