一株尿素酶阴性的新生隐球菌

本文报告从鸽粪标本中分离出的一株尿素酶试验阴性、咖啡酸玉米吐温琼脂培养呈棕色菌落的酵母样真菌。根据该菌袜的生理、生化特性及致病力，认为是尿素酶阴性的新生隐球菌。此外，应注意这种菌在自然界中的存在和对人类造成感染的可能。这是关于从自然环境中分离出尿素酶阴性新生隐球菌的首次发现和报告。

An urease negative Cryptococcus neoformans]

We report an urease negative Cryptococcus neoformans derived from pigeon dropping. This isolate produced brown pigmented colonies on cornmeal Tween-80 agar with 300 micrograms/ml caffeic acid, but was failure to hydrolyze urea. More identification tests were performed for this isolate, such as assimilation and fermentation of carbohydrates, nitrate assimilation, production of starch like compound, growth on GCP medium, germ tube formation and inoculation of mice, ect. Most of the results showed that the microbiological characteristics of the isolate were typical of C. neoformans except for negative urease test. Even though there has been a report about an urease negative C. neoformans derived from an AIDS patient, but we have never found any report about isolation from pigeon dropping or nature environment. We should pay attention to the exist of this atypical strain of C. neoformans in nature environment and the possibility of infection to human being. Additionally, we also be aware of the possibility of neglect when this urease negative C. neoformans is identified with urease test.