Firacative Carolina, Torres Germán, Rodríguez María Claudia, Escandón Patricia
Grupo de Microbiología, Instituto Nacional de Salud, Bogotá, D.C, Colombia.
Biomedica. 2011 Mar;31(1):118-23. doi: 10.1590/S0120-41572011000100014.
In Cúcuta, Cryptococcus gattii serotype B is commonly recovered from immunocompetent patients with cryptococcosis, but it has not been recovered from the environment in spite of its high incidence which is 77% out of reported cases.
The aim of this work was to carry out an extensive environmental sampling in Cúcuta, in an attempt to isolate C. gattii serotype B and to expand our knowledge about the ecology and epidemiology of this important yeast.
Samples associated with 3,634 trees from 40 zones of Cúcuta were collected and processed with 28 samples collected near the houses of four patients with cryptococcosis caused by C. gattii serotype B. The serotype of the recovered isolates was done using multiplex PCR, molecular patterns were determined by RFLP of the URA5 gene and mating type was determined using the primers MfαU, MfαL, MFa2U and MFa2L.
In total, 4,389 samples were processed and one isolate of C. gattii serotype B (VGI/a), two isolates of C. gattii serotype C (VGIII/α) and three isolates of C. neoformans var. grubii, serotype A (VNI/α), were recovered. The density of the recovered isolates varied from 50 to 350 cfu/g of soil.
This is the first report on the environmental isolation of C. gattii serotype B from Cúcuta. However, because of the low rate of recovery of isolates from soil only, the environmental niche of C. gattii has not been established and further environmental studies in Cúcuta are necessary, owing that this serotype is not only causing cryptococcosis but also has shown a higher virulence after the Vancouver outbreak.
在库库塔，从患有隐球菌病的免疫功能正常患者中通常能分离出加氏隐球菌B血清型，但尽管其发病率很高，在报告病例中占77%，却尚未从环境中分离出来。
本研究的目的是在库库塔进行广泛的环境采样，试图分离出加氏隐球菌B血清型，并扩展我们对这种重要酵母菌的生态学和流行病学的认识。
收集了与库库塔40个区域的3634棵树相关的样本，并对来自4例由加氏隐球菌B血清型引起的隐球菌病患者房屋附近采集的28个样本进行了处理。使用多重PCR确定分离株的血清型，通过URA5基因的限制性片段长度多态性（RFLP）确定分子模式，并使用引物MfαU、MfαL、MFa2U和MFa2L确定交配型。
共处理了4389个样本，分离出1株加氏隐球菌B血清型（VGI/α）、2株加氏隐球菌C血清型（VGIII/α）和3株新型隐球菌格鲁比变种，血清型A（VNI/α）。分离株的密度在每克土壤50至350 cfu之间。
这是关于从库库塔环境中分离出加氏隐球菌B血清型的首次报告。然而，由于仅从土壤中分离出分离株的比率较低，加氏隐球菌的环境生态位尚未确定，库库塔需要进一步开展环境研究，因为这种血清型不仅会引起隐球菌病，而且在温哥华疫情爆发后显示出更高的毒力。
