Ecological surveys of the Cryptococcus species complex in China

• Published in: Chinese medical journal 2012-02, Vol.125 (3), p.511-516
• Main Authors: Li, An-Sheng, Pan, Wei-Hua, Wu, Shao-Xi, Hideaki, Taguchi, Guo, Ning-Ru, Shen, Yong-Nian, Lu, Gui-Xia, Pan, Ru-Gui, Zhu, Miao-Chang, Chen, Min, Shi, Wei-Ming, Liao, Wan-Qing
• Format: Article
• Language: English
• Subjects: Animals; China; Columbidae - microbiology; Cryptococcosis - microbiology; Cryptococcus - isolation & purification; Cryptococcus gattii - isolation & purification; Cryptococcus neoformans - isolation & purification; Eucalyptus - microbiology; Feces - microbiology; 中国; 人类免疫缺陷病毒; 分子流行病学; 新生隐球菌; 溴麝香草酚蓝; 生态调查; 脲酶活性; 菌种
• ISSN: 0366-6999; 2542-5641
• DOI: 10.3760/cma.j.issn.0366-6999.2012.03.020

Background 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.Methods 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.Results 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.Conclusions 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 isolatewas isolated from pigeon droppings in Jinan city.No C.gattiiwas isolated in this study.