Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India.
Mycoses. 2013 May;56(3):222-8. doi: 10.1111/myc.12039. Epub 2013 Jan 22.
We report the first environmental isolation from India of Cryptococcus gattii, genotype amplified fragment length polymorphism 5 (AFLP5), which is one of the rarely reported genotypes of this pathogen. It originated from decayed wood inside a trunk hollow of Manilkara hexandra, a native tree in Delhi. We investigated 101 isolates of C. gattii, originating from 556 samples of decayed wood inside trunk hollows of 311 heterogeneous tree species and their surrounding soil. Of these, only a solitary isolate proved to be AFLP5, the remainder belonged to AFLP4. Antifungal susceptibility testing showed a low MIC90 (0.25 μg ml(-1) ) of the new azoles posaconazole and isavuconazole for these environmental isolates. Genotype AFLP5 has been mainly reported from environmental sources in Colombia and from clinical sources in California (USA), where it seems to be endemic. Phylogenetic analysis of multi-locus sequence typing data showed that the Indian AFLP5 C. gattii isolate had a distinct profile compared with a cluster of mainly Colombian and Californian C. gattii AFLP5 isolates. As molecular typing of human pathogenic fungi is still in its infancy and not accessible to many countries, our current knowledge cannot be taken as reflective of the true geographic distribution of C. gattii AFLP5 or its other rarely reported molecular types.
我们报告了Cryptococcus gattii 基因型扩增片段长度多态性 5（AFLP5）在印度的首次环境分离，这是该病原体很少报道的基因型之一。它源自德里本地树种 Manilkara hexandra 树干空洞内的腐朽木材。我们调查了 101 株源自 311 种异质树种树干空洞内腐朽木材和周围土壤的 556 个样本的 C. gattii 分离株。其中，只有一株是 AFLP5，其余均为 AFLP4。抗真菌药敏试验显示新型唑类药物泊沙康唑和伊曲康唑对这些环境分离株的 MIC90（0.25 μg/ml）较低。AFLP5 基因型主要从哥伦比亚的环境来源和美国加利福尼亚的临床来源报告，在那里它似乎是地方性的。多位点序列分型数据的系统发育分析表明，印度的 AFLP5 C. gattii 分离株与主要来自哥伦比亚和加利福尼亚的 AFLP5 C. gattii 分离株聚类相比具有独特的特征。由于人类致病性真菌的分子分型仍处于起步阶段，许多国家无法进行这种检测，因此我们目前的知识不能反映 C. gattii AFLP5 或其其他罕见报道的分子类型的真实地理分布。
