Institute of Dermatology, Chinese Academy of Medical Sciences, Nanjing, Jiangsu 210042, China.
Chin Med J (Engl). 2012 Feb;125(3):511-6.
Despite recent reports on the molecular epidemiology of cryptococcal infections in China, clinical isolates have been mostly reported from human immunodeficiency virus (HIV)-negative patients, and environmental isolates from China have rarely been included. The aim of this study was to investigate the ecological profile of Cryptococcus (C.) neoformans and C. gattii in China.
A survey was performed in 10 cities from 20°N (North latitude) to 50°N and in a Eucalyptus (E.) camaldulensis forestry farm at the Guixi forestry center, China.
Six hundred and twenty samples of pigeon droppings from 10 cities and 819 E. camaldulensis tree samples were collected and inoculated on caffeic acid cornmeal agar (CACA). The brown-colored colonies were recultured to observe their morphology, growth on canavanine-glycine-bromothymol-blue (CGB) medium, phenol oxidase and urease activities, serotype and mating type. There were obvious differences in the positive sample rates of C. neoformans in pigeon droppings collected from the different cities, ranging from 50% in the cities located at latitudes from 30°N - 40°N, 29% at 20°N - 30°N and 13% at 40°N - 50°N.
There were no differences in positive bevy rates (approximately 80%) among the three grouped cities. Mycological tests of 101 isolates purified from pigeon droppings revealed that they were C. neoformans var. grubii. We also observed variable capsular size around the C. neoformans cells in colonies with variable melanin production and the bio-adhesion of the natural C. neoformans cells with other microorganisms. One urease-negative C. neoformans isolate was isolated from pigeon droppings in Jinan city. No C. gattii was isolated in this study.
尽管最近有报道称中国 cryptococcal 感染的分子流行病学，但临床分离株主要来自人类免疫缺陷病毒（HIV）阴性患者，而来自中国的环境分离株则很少包括在内。本研究旨在调查中国新型隐球菌（C.）和隐球菌（C.）的生态特征。
在中国 10 个城市进行了调查，范围从北纬 20°到 50°，并在中国贵溪林业中心的桉树（E.）林场进行了调查。
从 10 个城市采集了 620 份鸽子粪便样本和 819 份桉树树样本，并接种在咖啡酸玉米粉琼脂（CACA）上。对棕色菌落进行再培养，观察其形态、在 canavanine-glycine-bromothymol-blue（CGB）培养基上的生长情况、酚氧化酶和脲酶活性、血清型和交配型。从不同纬度城市采集的鸽子粪便中新型隐球菌的阳性样本率存在明显差异，30°-40°N 纬度城市的阳性样本率为 50%，20°-30°N 纬度城市的阳性样本率为 29%，40°-50°N 纬度城市的阳性样本率为 13%。
三个分组城市的阳性样本率无差异（约 80%）。从鸽子粪便中分离的 101 个分离株的真菌学检测结果均为新型隐球菌 var. grubii。我们还观察到，在具有不同黑色素产生和新型隐球菌细胞与其他微生物的天然生物粘附的菌落中，新型隐球菌细胞周围的荚膜大小不同。从济南市鸽子粪便中分离出一株脲酶阴性的新型隐球菌。本研究未分离到隐球菌。
