Discipline of Mycology, Federal University of Pará, Pará, Brazil.
Mycopathologia. 2010 Jan;169(1):37-46. doi: 10.1007/s11046-009-9228-2.
The ecological niche or exact habitat of the fungus Paracoccidioides brasiliensis is not known, and few isolates have been obtained from the environment. In this study, ten isolates were analyzed with respect to antigenic composition, serology, pathogenicity, and molecular aspects. Gp43 is considered to be the molecular basis for the serodiagnosis of paracoccidioidomycosis; however, in this study only six of the environmental isolates secreted this molecule (four in great amounts and two in small amounts). Other molecules were also produced. When exoantigens from these isolates were tested using immunodiffusion, only four preparations were positive by ID tests. However, when these exoantigens were tested by ELISA, all of them except one were able to detect anti-P. brasiliensis antibodies. In Western blot assays, these exoantigens showed different reactivities. Isolates that secreted gp43 presented positive reactions for this molecule, and isolates that did not secrete gp43 gave positive reactions for other minor molecules. RAPD analysis revealed that there is great genetic variation between these environmental isolates. These isolates were non-pathogenic: no mortality was observed among the inoculated mice during an 18-month follow-up period.
巴西副球孢子菌的生态位或确切栖息地尚不清楚，从环境中获得的分离株也很少。在这项研究中，对 10 个分离株进行了抗原组成、血清学、致病性和分子方面的分析。糖蛋白 43 (gp43) 被认为是副球孢子菌病血清学诊断的分子基础；然而，在这项研究中，只有 6 个环境分离株分泌这种分子（4 个大量分泌，2 个少量分泌）。还产生了其他分子。当用免疫扩散法检测这些分离株的外抗原时，只有 4 种制剂的 ID 试验呈阳性。然而，当用 ELISA 检测这些外抗原时，除了一种以外，所有抗原都能够检测到抗巴西副球孢子菌抗体。在 Western blot 分析中，这些外抗原显示出不同的反应性。分泌 gp43 的分离株对此分子呈阳性反应，而不分泌 gp43 的分离株对其他较小的分子呈阳性反应。RAPD 分析显示，这些环境分离株之间存在很大的遗传变异。这些分离株无致病性：在 18 个月的随访期内，接种小鼠未观察到死亡。
