Title: Pneumocystis carinii - new fungal pathogen
- Bożena Dworecka-Kaszak
- Review articles
- Medical Mycology
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- Pneumocystis carinii, PCP, immunology, pathophysiology
Pneumocystis carinii is an atypical fungus able to bind specifically to type-1 epithelial alveolar cells and proliferate in the lung of immunocompromised patients provoking severe pneumonitis (PCP). The life cycle of this parasite remains hypothetical as continuous in vitro cultures are not available. Sińce many years Pneumocystis has been found as homogenic group of organisms infected lungs of a wide variety of host species, but genetic investiga-tion - pulsed field gel electrophoresis, karyotype analysis and mitochondrial and chromosomal DNA sequence analysis demonstrate differences betwe-en isolates among this genus. The epidemiology of PCP remains poor understood. It has long been thought that PCP occurred from reactivation of la-tent infection, but recently it has been proved hat PCP can result from de novo contamination from exogenous source. DNA gene sequences similar to those of different special form of Pneumocystis have been detected in air samples and in water, suggesting that this microorganism is present in our environment. Host defense against P. carinii depends on complex interactions between host immune cells and mediators. Animal models of P. carinii pneumonia using animals with genetic or induced immunodeficiencies, have provided recent and relevant information about the roles of lymphocytes in infection. The pulmonary surfactant, which covers the alveolar surface, plays an important role in the homeostasis of the alveolar environment and in the defense of the lung. During PCP alterations of both quantity and quality of pulmonary surfactant have been reported.