Environmental isolation and characterisation of Cryptococcus species from living trees in Havana city, Cuba
Environmental isolation and characterisation of Cryptococcus species from living trees in Havana city, Cuba
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DOI：
10.1111/j.1439-0507.2012.02168.x
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发表时间：
2012-05-01
期刊：
影响因子：
4.9
通讯作者：
Klaassen, C. H.
中科院分区：
文献类型：
--
作者：
Illnait-Zaragozi, M. T.;Martinez-Machin, G. F.;Klaassen, C. H.
从古巴患者体内分离出的隐球菌被鉴定为新型隐球菌变种。格鲁比。尽管这个物种长期以来一直与鸟粪有关，但最近的一项基因分型研究为其他接触来源提供了强有力的证据。我们对古巴哈瓦那的不同种类的树木进行了采样，以确定接触这种真菌的其他潜在来源。从古巴哈瓦那的 331 棵树和仙人掌中总共采集了 662 个样本。通过常规技术进行分离株的初步选择。结合使用 AFLP 分析和 DNA 序列分析对分离株进行了进一步表征。通过常规方法鉴定得到 121 个新型隐球菌和 61 个格特隐球菌分离株。分子分析表明，这些分离株均不是 C. gattii，只有一株分离株被证明是 C. neoformans var. var.格鲁比。总共鉴定出 27 个不同的其他物种。最常见的物种是 C. heveanensis (33%)。 65 个无法识别的分离株被分成 10 个潜在的新物种。传统培养方法对新型隐球菌复合体的特异性较低，需要应用分子分析来确认环境来源分离株的鉴定。导致古巴大多数人类隐球菌感染的环境生态位仍有待确定。
Cryptococcus isolates from Cuban patients were identified as C. neoformans var. grubii. Although this species has since long been associated with bird droppings, a recent genotyping study provided strong evidence for additional origins of exposure. We sampled different species of trees in Havana, Cuba to identify other potential sources of exposure to this fungus. A total of 662 samples were collected from 331 trees and cacti from Havana, Cuba. Initial selection of the isolates was carried out by conventional techniques. Isolates were further characterised using a combination of AFLP analysis and DNA sequence analysis. Identification by conventional methods yielded 121 C. neoformans and 61 C. gattii isolates. Molecular analyses showed that none of these isolates was C. gattii and only one isolate proved to be C. neoformans var. grubii. A total of 27 different other species were identified. The most prevalent species was C. heveanensis (33%). Sixty-five unidentifiable isolates segregated into ten potentially novel species. Conventional cultivation methods have a low specificity for C. neoformans complex and molecular analyses need to be applied to confirm identification of isolates from environmental sources. Environmental niches responsible for most of human cryptococcal infections in Cuba remain to be identified.