Castro e Silva D M, Santos D C S, Martins M A, Oliveira L, Szeszs M W, Melhem M S C
Instituto Adolfo Lutz, Secretariat of Health, Government of São Paulo State, Brazil
Instituto Adolfo Lutz, Secretariat of Health, Government of São Paulo State, Brazil.
Med Mycol. 2016 Jan;54(1):97-102. doi: 10.1093/mmy/myv066. Epub 2015 Sep 2.
Cryptococcal infection is transmitted by the inhalation of Cryptococcus spp. propagules. Information about the Cryptococcus species inhabiting plants might be clinically relevant due to the epidemiological role of these habitats as possible sources of human infection. The aim of this study was to increase the knowledge about the environmental occurrence of cryptococcosis agents. Hollow tree vegetal debris of nine plant species was sampled quarterly over a 12-month period. Melanized colonies were screened for Cryptococcus neoformans and C. gattii by biochemical tests, followed by URA5-RFLP molecular analysis, M13 fingerprinting assays, and mating-typing with the specific a and α primers. The susceptibility to fluconazole of all of the confirmed species colonies was determined using the AFST-EUCAST broth dilution method. We found that the typical Brazilian flora tree Hymenaea courbaril yielded a high cryptococcal burden (median, 10(2) CFU/g) during the summer, autumn and winter seasons. C. neoformans VNI molecular type MAT alpha was identified in all of the samples. The fingerprinting analyses showed great molecular variability with no correlation with the susceptibility profile to fluconazole (MIC range 4 to ≥64 mg/l). To our knowledge, this study is the first describing the association between C. neoformans and Hymenaea courbaril. These observations extend the known geographic distribution of and substantiate a new urban environmental niche for C. neoformans and also emphasize the genetic diversity of the environmental C. neoformans VNI molecular type isolates.
隐球菌感染是通过吸入隐球菌属的繁殖体传播的。由于这些栖息地作为人类感染可能来源的流行病学作用，关于栖息在植物中的隐球菌种类的信息可能具有临床相关性。本研究的目的是增加对隐球菌病病原体在环境中存在情况的了解。在12个月的时间里，每季度对9种植物的空心树植物残体进行采样。通过生化试验筛选黑色素化菌落中的新型隐球菌和格特隐球菌，随后进行URA5-RFLP分子分析、M13指纹分析以及使用特异性a和α引物进行交配型分析。使用AFST-EUCAST肉汤稀释法测定所有确诊菌种菌落对氟康唑的敏感性。我们发现，典型的巴西植物树种孪叶豆在夏季、秋季和冬季产生了较高的隐球菌负荷（中位数，10(2) CFU/g）。在所有样本中均鉴定出新型隐球菌VNI分子型MATα。指纹分析显示出很大的分子变异性，与对氟康唑的敏感性谱（MIC范围为4至≥64 mg/l）无关。据我们所知，本研究是首次描述新型隐球菌与孪叶豆之间的关联。这些观察结果扩展了新型隐球菌已知的地理分布，并证实了其一个新的城市环境生态位，同时也强调了环境中新型隐球菌VNI分子型分离株的遗传多样性。
