Arantes Thales Domingos, Theodoro Raquel Cordeiro, Teixeira Marcus de Melo, Bosco Sandra de Moraes Gimenes, Bagagli Eduardo
Departamento de Microbiologia e Imunologia, Instituto de Biociências de Botucatu, Universidade Estadual Paulista/UNESP, Botucatu, Brazil.
Instituto de Medicina Tropical-IMT/RN, Universidade Federal do Rio Grande do Norte/UFRN, Natal, Brazil.
PLoS Negl Trop Dis. 2016 Apr 5;10(4):e0004606. doi: 10.1371/journal.pntd.0004606. eCollection 2016 Apr.
Paracoccidioides brasiliensis and Paracoccidioides lutzii are the etiological agents of Paracoccidioidomycosis (PCM), and are easily isolated from human patients. However, due to human migration and a long latency period, clinical isolates do not reflect the spatial distribution of these pathogens. Molecular detection of P. brasiliensis and P. lutzii from soil, as well as their isolation from wild animals such as armadillos, are important for monitoring their environmental and geographical distribution. This study aimed to detect and, for the first time, evaluate the genetic diversity of P. brasiliensis and P. lutzii for Paracoccidioidomycosis in endemic and non-endemic areas of the environment, by using Nested PCR and in situ hybridization techniques.
METHODS/PRINCIPAL FINDINGS: Aerosol (n = 16) and soil (n = 34) samples from armadillo burrows, as well as armadillos (n = 7) were collected in endemic and non-endemic areas of PCM in the Southeastern, Midwestern and Northern regions of Brazil. Both P. brasiliensis and P. lutzii were detected in soil (67.5%) and aerosols (81%) by PCR of Internal Transcribed Spacer (ITS) region (60%), and also by in situ hybridization (83%). Fungal isolation from armadillo tissues was not possible. Sequences from both species of P. brasiliensis and P. lutzii were detected in all regions. In addition, we identified genetic Paracoccidioides variants in soil and aerosol samples which have never been reported before in clinical or armadillo samples, suggesting greater genetic variability in the environment than in vertebrate hosts.
CONCLUSIONS/SIGNIFICANCE: Data may reflect the actual occurrence of Paracoccidioides species in their saprobic habitat, despite their absence/non-detection in seven armadillos evaluated in regions with high prevalence of PCM infection by P. lutzii. These results may indicate a possible ecological difference between P. brasiliensis and P. lutzii concerning their wild hosts.
巴西副球孢子菌和卢氏副球孢子菌是副球孢子菌病（PCM）的病原体，很容易从人类患者中分离出来。然而，由于人类迁移和较长的潜伏期，临床分离株不能反映这些病原体的空间分布。从土壤中分子检测巴西副球孢子菌和卢氏副球孢子菌，以及从犰狳等野生动物中分离它们，对于监测它们的环境和地理分布很重要。本研究旨在通过巢式PCR和原位杂交技术，首次检测并评估巴西副球孢子菌和卢氏副球孢子菌在环境中的地方病和非地方病区域的遗传多样性。
方法/主要发现：在巴西东南部、中西部和北部地区PCM的地方病和非地方病区域，收集了来自犰狳洞穴的气溶胶（n = 16）和土壤（n = 34）样本，以及犰狳（n = 7）。通过对内部转录间隔区（ITS）区域进行PCR（60%）以及原位杂交（83%），在土壤（67.5%）和气溶胶（81%）中检测到了巴西副球孢子菌和卢氏副球孢子菌。无法从犰狳组织中分离出真菌。在所有区域都检测到了巴西副球孢子菌和卢氏副球孢子菌两个物种的序列。此外，我们在土壤和气溶胶样本中鉴定出了临床或犰狳样本中从未报道过的副球孢子菌基因变体，这表明环境中的遗传变异性比脊椎动物宿主中的更大。
结论/意义：尽管在卢氏副球孢子菌感染率高的地区评估的7只犰狳中未发现/未检测到副球孢子菌属物种，但数据可能反映了它们在腐生栖息地中的实际存在情况。这些结果可能表明巴西副球孢子菌和卢氏副球孢子菌在其野生宿主方面可能存在生态差异。
