In this way, we detected a 28S rDNA fragment with a product of nearly 375 bp in 19 out of the 21 isolates tested. However, applying a semi-nested PCR

system to these DNA check details samples with a new pair of primers specific for Coccidioides spp., we detected bands of sizes compatible with the expected fragment in the DNA of all cultures tested. As a control, the DNA of 41 lineages of other human pathogenic fungi (S. schenckii, P. brasiliensis, H. capsulatum, A. niger, A. fumigatus, A. nidulans, B. dermatitidis, M. canis, T. rubrum, T. mentagrophytes, C. neoformans and C. gattii) were submitted to the same protocol, and all results were negative. The results were also negative when the protocol was applied to DNA from S3I-201 supplier bacteria. Our results indicate the high specificity of PCR with these primers and highlight the increased sensitivity, expected in nested PCR reactions

using DNA obtained from soil samples. The next step was to optimize direct PCR with specific primers for detecting Coccidioides spp. in the DNA extracted from our 24 soil samples. The direct PCR method revealed the expected fragment only in 8 (33.3%) soil samples, but when the semi-nested system was used, all the soil samples were positive, thus confirming to be a very sensitive method for detecting Coccidioides spp. 28S rDNA. It is KPT-8602 molecular weight important to note that all of the positive soil samples were collected in and around armadillo burrows strongly suspected to be heavily contaminated because their disturbance check caused acute cases of human and canine coccidioidomycosis. It is possible that these restricted sites harbor high concentrations of viable arthroconidia of C. immitis, which are easily detected by animal inoculation, as well as dormant or dead fungal elements with DNA partially preserved, which can only be detected by molecular tools. To evaluate these factors, it should be of interest to analyze soil samples collected in concentric circles from

the center of the focus. As controls for the PCR protocols applied to our soil samples from Piauí, we analyzed DNA extracted from soil samples collected in non-endemic areas of the cities of Goiânia (capital of the state of Goiás) and Brasília (Capital of Brazil), and none presented the 375-bp band, reinforcing our results. Thus, we believe it is important to note that the primer system RFA12 + P2 was able to identify both C. immitis and C. posadasii. The molecular detection of Coccidioides spp. in suspected soil or in clinical specimens has obvious importance for epidemiological studies and laboratory diagnosis of coccidioidomycosis. Furthermore, molecular procedures such as PCR present substantial advantages, as they reduce the biological risk inherent in the classical techniques and reduce the time necessary to identify a suspected environmental focus or diagnose a clinical case to a few hours.