Herrag M, Elfassy Fihry M T, Alaoui Yazidi A
Service de pneumologie, hôpital Ibn Nafis, CHU Mohammed VI, faculté de médecine et de pharmacie, université Cadi Ayyad, Marrakech, Maroc.
Rev Pneumol Clin. 2010 Dec;66(6):342-6. doi: 10.1016/j.pneumo.2009.09.007. Epub 2010 Feb 12.
Pneumocystis was discovered nearly a century ago. It causes fatal pneumonia in immunocompromised individuals, especially in AIDS patients. Knowledge of the different species remained rudimentary until the mid-eighties when DNA analysis revealed its extensive diversity. In fact, it is no longer considered as a zoonosis. Pneumocystis organisms derived from different hosts have very different DNA sequences, indicating multiple species. Due to the genetic and functional disparities, the organism that causes human PCP is now named Pneumocystis jirovecii/Frenkel, 1999. We continue to call Pneumocystis carinii the species found in rats. This will allow for a single international language and avoid confusion. Changing the organism's name does not preclude the use of the well-known acronym PCP because it can also be read "PneumoCystis Pneumonia." The DNA sequences and genotypage have shown that variations exist among samples of P. jiroveci. Molecular biology is helpful in the study of the mechanisms of transmission, which can only occur in the same host and the different resistances as well as providing a better understanding of the relationship between host and pathogen. P. jirovecii pneumonia in immunosuppressed patients was previously thought to result from the reactivation of a latent infection acquired in early childhood. However, today, it is believed to result from a new infection from an exogenous source.
肺孢子菌在近一个世纪前就被发现了。它会在免疫功能低下的个体中引发致命性肺炎，尤其是在艾滋病患者中。直到八十年代中期，当DNA分析揭示出其广泛的多样性之前，人们对不同种类的了解还很基础。事实上，它现在已不再被视为一种人畜共患病。源自不同宿主的肺孢子菌生物具有非常不同的DNA序列，这表明存在多个物种。由于基因和功能上的差异，导致人类肺孢子菌肺炎（PCP）的生物体现在被命名为耶氏肺孢子菌/弗伦克尔，1999年。我们继续将在大鼠中发现的物种称为卡氏肺孢子菌。这将形成一种单一的国际通用名称并避免混淆。改变生物体的名称并不妨碍使用广为人知的首字母缩写PCP，因为它也可以读作“肺孢子菌肺炎”。DNA序列和基因分型表明，耶氏肺孢子菌的样本之间存在差异。分子生物学有助于研究传播机制，这种传播只能在同一宿主内发生，以及不同的抵抗力，还能更好地理解宿主与病原体之间的关系。免疫抑制患者的耶氏肺孢子菌肺炎以前被认为是由儿童早期获得的潜伏感染重新激活所致。然而，如今人们认为它是由外源性病原体的新感染引起的。
