Immunological and Genetical Heterogeneity of Pneumocystis carinii

据报道，由肺孢子虫引起的机会性感染发生在多种哺乳动物身上，包括猪、马、雪貂、大鼠、小鼠和人类。长期以来，来自这些动物的肺孢子虫被认为是唯一的卡氏肺孢子虫，这导致了卡氏肺孢子虫肺炎是人畜共患病的猜测。在受控的实验条件下，卡氏肺孢子虫显然可以通过空中途径在同一物种的动物之间传播。然而，一个宿主物种的卡氏肺孢子虫感染另一个物种成员的能力尚不清楚。由于它们的相似之处，试图区分这些生物体的形态是困难的。在本研究中，我们通过血清型、分裂型和酵母烯分析来研究来自不同宿主物种的肺孢子虫的表型和基因变异。对于血清病的分析，我们使用了间接荧光抗体技术和Western印迹技术，并使用了来自小鼠、大鼠和人类的针对肺孢子虫生物体的单克隆和多克隆抗体。血清学和酵母学分析清楚地证明了它们的表型差异。用大鼠和小鼠衍生的生物的特定引物进行聚合酶链式反应，然后用限制性内切酶处理产物，对裂殖子进行分析，证实了生物之间的基因差异。我们可以毫不含糊地区分大鼠、小鼠和人类肺孢子虫生物的技术和试剂的出现，促使我们重新审视卡氏肺孢子虫从一个宿主物种到另一个宿主物种的传播问题。

Opportunistic infections caused by Pneumocystis organisms have been reported in a variety of mammals including pigs, horses, ferrets, rats, mice, and humans. Pneumocystis organisms from those animals has long been considered to belong to the only species, Pneumocystis carinii, leading the speculation that P.carinii pneumonia is zoonosis. P.carinii is clearly transmissible between animals of the same species by the airborne route under controlled experimental conditions. However, the ability of P.carinii from one host species to infect members of another species is unclear. Attempts of morphological distinguishment of the organisms were difficult because of their resemblance. In the present study, we performed serodeme, schizodeme and zymodene analyzes to study both phenotype and genotype variation among Pneumocystis organisms from different host species. For serodeme analysis, we employed an indirect fluorescence antibody technique and a Western blot technique with the use of monoclonal and polyclonal antibodies raised against Pneumocystis organisms from mice, rats, and humans. Serodeme and zymodeme analyzes clearly demonstrated the differences of their phenotypes. Schizodeme analysis using polymerase chain reaction with specific primers for rat and mouse-derived organisms followed by treatment of the products by restriction enzymes confirmed genotype differences among organisms. The availability of techniques and reagents with which we could unequivocally distinguish between rats, mice, and human Pneumocystis organisms is prompting us to reexamine the issue of transmission of P.carinii from one host species to another.