Cryptococcus gattii

Cryptococcus gattii has recently been divided into five species. These are C. gattii, C. bacillisporus, C. deuterogattii, C. tetragattii, and C. decagattii. == Etymology ==

The genus name Cryptococcus comes from Ancient Greek κρυπτός (), meaning "hidden", and κόκκος (), meaning "grain". The specific name gattii comes from Italian mycologist Franco Gatti. ==Environmental microbiology==

C. gattii occupies an environmental niche in decaying hollows of trees native to tropical as well as subtropical and temperate regions. It may then contaminate nearby soil or persist in wood products. One study concluded "[j]ust as people who travel to South America are told to be careful about drinking the water, people who visit other areas like California, the Pacific Northwest, and Oregon need to be aware that they are at risk for developing a fungal infection, especially if their immune system is compromised." ==Epidemiology==

C. gattii infections were initially thought to be restricted to tropical and subtropical regions. The highest incidences of C. gattii infections occur in Papua New Guinea and Northern Australia. However cases have been reported in various other regions including Brazil, India and the Pacific Northwest of North America. The spread of this fungus is hypothesized to be linked to climate change. In the North America, there are now two strains of this fungus in the northwestern part of the region, affecting many terrestrial animals. VGII C. gattii have probably undergone either bisexual or unisexual reproduction in multiple different locales, thus giving rise to novel virulent phenotypes. == Pathology ==

C. gattii is notable for causing cryptococcosis in otherwise healthy persons. C. gattii infection is more likely to be limited to the lung (rather than disseminating to the CNS). When CNS infection does occur, it may involve more localised lesions (cryptococcomas) rather than the diffuse infection characteristic of C. neoformans. ==Diagnosis==

Culture of sputum, bronchoalveolar lavage, lung biopsy, cerebrospinal fluid or brain biopsy specimens on selective agar allows differentiation between the five members of the C. gattii species complex and the two members of the C. neoformans species complex. The optimal growth temperature of C. gattii is . ==Treatment==

Medical treatment consists of prolonged intravenous therapy (for 6–8 weeks or longer) with the antifungal drug amphotericin B, either in its conventional or lipid formulation. The addition of oral or intravenous flucytosine improves response rates. Oral fluconazole is then administered for six months or more. Antifungals alone are often insufficient to cure C. gattii infections, and surgery to resect infected lung (lobectomy) or brain is often required. Ventricular shunts and Ommaya reservoirs are sometimes employed in the treatment of central nervous system infection. People who have C. gattii infection need to take prescription antifungal medication for at least 6 months; usually the type of treatment depends on the severity of the infection and the parts of the body that are affected. • For people who have asymptomatic infections or mild-to-moderate pulmonary infections, the treatment is usually fluconazole. • For people who have severe lung infections, or infections in the central nervous system (brain and spinal cord), the treatment is amphotericin B in combination with flucytosine. ==References==