Medicine Faculty, Mycology laboratory, Federal University of Mato Grosso, Fernando Correa da Costa Avenue, 2367, Boa Esperança - Cuiabá/MT, Brazil.
J Occup Med Toxicol. 2012 Jun 8;7(1):11. doi: 10.1186/1745-6673-7-11.
The Cryptococcus spp is currently composed of encapsulated yeasts of cosmopolitan distribution, including the etiological agents of cryptococcosis. The fungus are found mainly in substrates of animal and plant origin. Human infection occurs through inhalation of spores present in the environment.
Eighty-four swab collections were performed on dust found on books in three libraries in the city of Cuiabá, state of Mato Grosso, Brazil. The material was seeded in Sabouraud agar and then observed for characteristics compatible with colonies with a creamy to mucous aspect; the material was then isolated in birdseed (Niger) agar and cultivated at a temperature of 37°C for 5 to 7 days. Identification of isolated colonies was performed by microscopic observation in fresh preparations dyed with India ink, additional tests performed on CGB (L-canavanine glycine bromothymol blue), urea broth, and carbohydrate assimilation tests (auxanogram).
Of the 84 samples collected from book dust, 18 (21.4%) were positive for Cryptococcus spp totalizing 41 UFC's. The most frequently isolated species was C. gattii 15 (36.6%); followed by C. terreus, 12 (29.3%); C. luteolus 4 (9.8%); C. neoformans, and C. uniguttulatus 3 (7.3%), and C. albidus and C. humiculus with 2 (4.6%) of the isolates.
The high biodiversity of the yeasts of the Cryptococcus genus, isolated from different environmental sources in urban areas of Brazil suggests the possibility of individuals whose immune systems have been compromised or even healthy individuals coming into sources of fungal propagules on a daily bases throughout their lives. This study demonstrates the acquisition possible of cryptococcosis infection from dust in libraries.
Cryptococcus spp 目前由分布广泛的具囊酵母组成，包括 cryptococcosis 的病原体。该真菌主要存在于动物和植物来源的基质中。人类感染是通过吸入环境中存在的孢子引起的。
从巴西马托格罗索州库亚巴市的三所图书馆的书籍灰尘中采集了 84 份拭子样本。将该材料接种于 Sabouraud 琼脂上，然后观察与奶油状至粘糊状外观相符的菌落特征；然后将该材料在鸟食（Niger）琼脂上分离并在 37°C 下培养 5 至 7 天。通过在新鲜印度墨水染色的制备物中进行显微镜观察、在 CGB（L--canavanine glycine bromothymol blue）、尿素肉汤和碳水化合物同化试验（auxanogram）上进行的其他试验来鉴定分离的菌落。
从书尘中采集的 84 个样本中，有 18 个（21.4%）呈 Cryptococcus spp 阳性，共检测到 41 UFC。最常分离的物种是 C. gattii 15 个（36.6%）；其次是 C. terreus 12 个（29.3%）；C. luteolus 4 个（9.8%）；C. neoformans 和 C. uniguttulatus 各 3 个（7.3%），C. albidus 和 C. humiculus 各 2 个（4.6%）。
从巴西城市不同环境来源分离出的 Cryptococcus 属酵母具有高度的生物多样性，这表明免疫系统受损的个体甚至健康个体在其一生中都有可能每天接触到真菌繁殖体的来源。本研究表明从图书馆灰尘中可能获得 cryptococcosis 感染。
