Pneumocystis jiroveci

Pneumocystis jiroveci is a yeast-like fungus of the genus Pneumocystis. The causative organism of Pneumocystis pneumonia, it is an important human pathogen, particularly among immunocompromised hosts. Prior to its discovery as a human-specific pathogen, Pneumocystis jiroveci was known as Pneumocystis carinii.

Taxonomy[edit | edit source]

Pneumocystis jiroveci is a member of the fungal genus Pneumocystis. The species name jiroveci is named after the Czech parasitologist Otto Jirovec, who first identified Pneumocystis as a cause of pneumonia in humans.

Morphology[edit | edit source]

Pneumocystis jiroveci is a small, unicellular organism that can exist in both a trophozoite (trophic) form and a cyst form. The trophic form is smaller and replicates via binary fission, while the cyst form is larger and can contain up to eight intracystic bodies.

Pathogenesis[edit | edit source]

Pneumocystis jiroveci is the causative organism of Pneumocystis pneumonia (PCP), a severe lung disease that primarily affects immunocompromised individuals, such as those with HIV/AIDS, those undergoing chemotherapy, and those receiving immunosuppressive therapy following organ transplantation. The organism is believed to be transmitted via airborne droplets.

Diagnosis and Treatment[edit | edit source]

Diagnosis of Pneumocystis jiroveci infection is typically made via identification of the organism in sputum or bronchoalveolar lavage fluid. Treatment typically involves a combination of trimethoprim and sulfamethoxazole, although other antifungal agents may be used in cases of allergy or resistance.