Molecular identification of Coccidioides spp. in soil samples from Brazil
1 Laboratório de Micologia do Instituto de Pesquisa Clínica Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil
2 Laboratório de Ecologia Microbiana Molecular do Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Brasil
3 Laboratório de Biologia Computacional e Sistemas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Brasil
4 Universidade Estadual do Piauí, Teresina, Piauí, Brasil
5 Universidade Federal do Piauí, Teresina, Piauí, Brasil
BMC Microbiology 2011, 11:108 doi:10.1186/1471-2180-11-108Published: 16 May 2011
Since 1991 several outbreaks of acute coccidioidomycosis (CM) were diagnosed in the semi-arid Northeast of Brazil, mainly related to disturbance of armadillo burrows caused by hunters while digging them for the capture of these animals. This activity causes dust contaminated with arthroconidia of Coccidioides posadasii, which, once inhaled, cause the mycosis. We report on the identification of C. posadasii in soil samples related to outbreaks of CM.
Twenty four soil samples had their DNA extracted and subsequently submitted to a semi-nested PCR technique using specific primers. While only 6 (25%) soil samples were positive for C. posadasii by mice inoculation, all (100%) were positive by the molecular tool.
This methodology represents a simple, sensitive and specific molecular technique to determine the environmental distribution of Coccidioides spp. in endemic areas, but cannot distinguish the species. Moreover, it may be useful to identify culture isolates. Key-words: 1. Coccidioidomycosis. 2. Coccidioides spp. 3. C. posadasii. 4. Semi-arid. 5. Semi-nested PCR