Pneumocystidomycetes

Pneumocystidomycetes is a class of fungi that includes a single order, Pneumocystidales, which in turn includes a single family, Pneumocystidaceae. This family contains the single genus Pneumocystis, which includes several species that are known to cause pneumonia in mammals, including humans.

Taxonomy

The class Pneumocystidomycetes was first described in 2007 by the mycologist Joseph F. Bischoff. The name of the class is derived from the genus Pneumocystis, which was first described in 1909 by the French physicians Charles Jules Henry and Louis Charles Émile Lemoine. The genus name Pneumocystis is derived from the Greek words for "lung" (pneumo) and "bladder" (cystis), in reference to the characteristic cysts that are formed in the lungs of infected individuals.

Characteristics

Species in the class Pneumocystidomycetes are obligate parasites, meaning they can only survive by infecting a host organism. They are typically found in the lungs of mammals, where they can cause a form of pneumonia known as Pneumocystis pneumonia (PCP). The most well-known species is Pneumocystis jirovecii, which is a significant cause of illness and death in individuals with weakened immune systems, such as those with HIV/AIDS.

Pathogenesis

The exact mechanism by which Pneumocystidomycetes cause disease is not fully understood. However, it is believed that the fungi attach to the cells lining the lungs, where they reproduce and form cysts. These cysts can rupture, releasing spores that can infect other areas of the lungs. The immune response to the infection can cause inflammation and damage to the lung tissue, leading to the symptoms of pneumonia.

Treatment and Prevention

Treatment for infections caused by Pneumocystidomycetes typically involves the use of antifungal medications, such as trimethoprim-sulfamethoxazole. In severe cases, additional treatments may be needed to manage the symptoms of pneumonia. Prevention strategies include the use of prophylactic antifungal medications in individuals at high risk of infection, such as those with HIV/AIDS.