Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, India.
Crit Rev Microbiol. 2012 Feb;38(1):1-16. doi: 10.3109/1040841X.2011.606426. Epub 2011 Dec 1.
An overview of work done to-date in India on environmental prevalence, population structure, seasonal variations and antifungal susceptibility of Cryptococcus neoformans and Cryptococcus gattii is presented. The primary ecologic niche of both pathogens is decayed wood in trunk hollows of a wide spectrum of host trees, representing 18 species. Overall, C. neoformans showed a higher environmental prevalence than that of C. gattii which was not found in the avian habitats. Apart from their arboreal habitat, both species were demonstrated in soil and air in close vicinity of their tree hosts. In addition, C. neoformans showed a strong association with desiccated avian excreta. An overwhelming number of C. neoformans strains belonged to genotype AFLP1/VNI, var. grubii (serotype A), whereas C. gattii strains were genotype AFLP4/VGI, serotype B. All of the environmental strains of C. neoformans and C. gattii were mating type α (MATα). Contrary to the Australian experience, Eucalyptus trees were among the epidemiologically least important and, therefore, the hypothesis of global spread of C. gattii through Australian export of infected Eucalyptus seeds is rebutted. Reference is made to long-term colonization of an abandoned, old timber beam of sal wood (Shorea robusta) by a melanin positive (Mel(+)) variant of Cryptococcus laurentii that was pathogenic to laboratory mice.
本文概述了在印度开展的有关新型隐球菌和格特隐球菌的环境流行率、种群结构、季节性变化和抗真菌药敏性的研究工作。这两种病原体的主要生态位是宿主树木树干空洞中的腐朽木材，涉及 18 个物种。总体而言，新型隐球菌的环境流行率高于格特隐球菌，后者未在鸟类栖息地发现。除了树木栖息地外，这两个物种还在其宿主树附近的土壤和空气中被发现。此外，新型隐球菌与干燥的鸟类粪便有很强的关联性。大量的新型隐球菌菌株属于 AFLP1/VNI 基因型和 grubii 变种（血清型 A），而格特隐球菌菌株则属于 AFLP4/VGI 基因型和 B 血清型。所有的新型隐球菌和格特隐球菌环境菌株都是交配型α（MATα）。与澳大利亚的经验相反，桉树在流行病学上是最不重要的树种之一，因此，全球范围内格特隐球菌通过澳大利亚出口受感染的桉树种子传播的假说被推翻。文中还提到了一种黑色素阳性（Mel(+））的 Laurentii 隐球菌变种对实验室小鼠具有致病性，该变种长期定殖于废弃的老 Sal 木（Shorea robusta）横梁上。
