Cryptococcus neoformans and its cousin Cryptococcus gattii are opportunistic fungal pathogens that cause life-threatening infections in immunocompromised individuals.cryptococcus neoformans They belong to the Basidiomycota and are facultative intracellular yeasts (Chang, 2008). They are found in the environment as basidiospores or desiccated yeast cells and can be inhaled from contaminated dust. The infections they cause can occur throughout the body, but most commonly in the lungs and central nervous system (cryptococcal meningitis, CCM). C. neoformans is globally distributed and most cases of infection are related to inhalation of the fungus from bird droppings (most commonly, pigeon feces) or from close contact with pigeons. Direct human-to-human transmission is rare, but has been reported after organ transplantation and in patients with severe combined immune deficiency.
Initially, cryptococcosis develops in the lungs as a pneumonia-like illness with nonspecific symptoms, but can also spread to the brain and other parts of the body, including the skin.cryptococcus neoformans This infection can be difficult to diagnose and is more common in people with advanced HIV/AIDS. Other risk factors include long-term corticosteroid use and hematologic cancers. It is not known if the infections caused by these two species differ in severity or pathogenesis, but their different clinical presentations have led to the creation of separate diagnostic tests.
The opportunistic fungal pathogens Aspergillus fumigatus, Candida auris, and Cryptococcus neoformans have risen in prominence in recent years due to their increasing global burden of disease, the development of antifungal resistance, and their association with adverse outcomes in cancer patients.cryptococcus neoformans To address this growing public health threat, the World Health Organization recently published a list of high priority fungal pathogens called the Fungal Priority Pathogens List (FPPL). This article takes a look at the top-ranked fungus in the FPPL, C. neoformans, with the aim of driving future research efforts to improve diagnosis, therapy, and outcomes associated with this opportunistic infectious agent.
Yeast (Cryptococcus) infections occur when spores or hyphae, which are the primary form of these organisms in the environment, enter the body and transform into their yeast form, which can then invade cells.cryptococcus neoformans Most infections are mediated by inhalation of spores, but infection can also occur through skin wounds or blood transfusions. Symptoms of infection can range from a mild pneumonia-like illness to a fatal brain infection. Various studies have shown that both internalized and free cryptococci can pass across the blood-brain barrier, either by transcytosis through barrier epithelial cells or via breach of tight junctions.
Healthcare providers can diagnose cryptococcosis by reviewing medical history, examining the person, and taking a sample of tissue or fluid for laboratory testing.cryptococcus neoformans Treatment includes antibiotics. The most effective medicines for this infection are fluconazole and itraconazole. Infected people must take these drugs for 6 months or longer to control the infection and prevent relapses. If relapse occurs, the person may experience immune reconstitution inflammatory syndrome, or IRIS. This is a condition where the body’s natural defenses overreact to the medications used to treat the infection and make symptoms worse.