巴西北部原生林和河流中分离的新型隐球菌 VGII。
Cryptococcus gattii VGII isolated from native forest and river in Northern Brazil.
机构信息
Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil.
Laboratório de Micologia Médico do Instituto de Pesquisas Clínicas Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
出版信息
Braz J Microbiol. 2019 Apr;50(2):495-500. doi: 10.1007/s42770-019-00066-6. Epub 2019 Mar 9.
BACKGROUND
Cryptococcosis is a global invasive mycosis associated with significant morbidity and mortality. In the northern region of Brazil, this disease is caused by Cryptococcus neoformans genotype VNI and Cryptococcus gattii genotype VGII. However, few environmental studies have been conducted in this large tropical area.
AIMS
This study was performed to isolate, genotype, and determine the frequency of cryptococcal agents in environmental samples near Manaus, Amazonas, Brazil.
METHODS
A total of 970 environmental samples (290 from soil, 290 from decaying plants, 5 from insects, 280 from the Negro river, and 105 from small streams within the city of Manaus) were collected and plated on Niger seed agar. In addition, 20 sub-cultures obtained from each positive sample were analyzed by PCR-RFLP (URA5) and PCR for genotyping and determination of mating type.
RESULTS
Six samples were positive for isolates from the C. gattii species complex. Of those, three samples were from Adolpho Ducke Forest Reserve and three were from the Negro river. All isolates were C. gattii genotype VGII (mating type MATα).
CONCLUSION
Genotype VGII proved to be the most important genotype found in the environmental samples. The genotype VGII has been described as one of the most virulent and less susceptible to antifungals and responsible for important outbreaks. This is the first study to demonstrate isolation of C. gattii (VGII) from the Negro river.
背景
cryptococcosis 是一种全球性的侵袭性真菌感染，与较高的发病率和死亡率相关。在巴西北部地区，这种疾病是由 cryptococcus neoformans 基因型 vni 和 cryptococcus gattii 基因型 vgii 引起的。然而，在这个大型热带地区，很少有关于环境的研究。
目的
本研究旨在分离、基因分型并确定巴西马瑙斯附近环境样本中 cryptococcal 剂的频率。
方法
共采集 970 份环境样本（土壤 290 份、腐烂植物 290 份、昆虫 5 份、内格罗河 280 份、马瑙斯市内小流 105 份），并在尼日尔种子琼脂上进行平板培养。此外，从每个阳性样本中获得的 20 个亚培养物通过 PCR-RFLP（URA5）和 PCR 进行基因分型和交配型测定。
结果
从 c. gattii 种复合体中分离出的 6 个样本呈阳性。其中，3 个样本来自阿道夫·杜克森林保护区，3 个样本来自内格罗河。所有分离株均为 c. gattii 基因型 vgii（交配型 matα）。
结论
VGII 基因型被证明是环境样本中最重要的基因型。VGII 基因型已被描述为最具毒力、对抗真菌药物的敏感性较低、并导致重要暴发的基因型之一。这是首次从内格罗河分离出 c. gattii（VGII）的研究。
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