Molecular analysis of Aspergillus section Flavi isolated from Brazil nuts

Brazil nuts are an important export market in its main producing countries, including Brazil, Bolivia, and Peru. Approximately 30,000 tons of Brazil nuts are harvested each year. However, substantial nut contamination by Aspergillus section Flavi occurs with subsequent production of aflatoxins. In our study, Aspergillus section Flavi were isolated from Brazil nuts (Bertholletia excelsa), and identified by morphological and molecular means. We obtained 241 isolates from nut samples, 41% positive for aflatoxin production. Eighty-one isolates were selected for molecular investigation. Pairwise genetic distances among isolates and phylogenetic relationships were assessed. The following Aspergillus species were identified: A. flavus, A. caelatus, A. nomius, A. tamarii, A. bombycis, and A. arachidicola. Additionally, molecular profiles indicated a high level of nucleotide variation within beta-tubulin and calmodulin gene sequences associated with high genetic divergence from RAPD data. Among the 81 isolates analyzed by molecular means, three of them were phylogenetically distinct from all other isolates representing the six species of section Flavi. A putative novel species was identified based on molecular profiles.CAPESCAPESCNPqCNPqFAPESPFAPES

A bovine teat papilloma specimen harboring Deltapapillomavirus (BPV-1) and Xipapillomavirus (BPV-6) representatives

The common occurrence of multiple papillomavirus infections has been shown in several studies involving the human host. However, investigations with the aim of identifying mixed papillomavirus infections in cattle have been conducted only recently. In the current work we describe a co-infection with two different bovine papillomavirus (BPV) types that was identified in a bovine teat papilloma. The skin wart was obtained from a cow belonging to a Brazilian beef herd. A PCR assay was carried out with the FAP primer pair, which amplifies a partial segment of the L1 gene (approximately 478 bp), and the amplicon was submitted to direct sequencing. Because nucleotide sequences with satisfactory quality scores were not obtained, the amplicon was cloned and further sequencing, involving ten selected clones, was performed. The sequence analysis of the cloned inserts revealed the presence of two different BPV types. BPV-1 (Deltapapillomavirus genus) was detected in six clones, while BPV-6 (Xipapillomavirus genus) was detected in four clones. This finding confirms the presence of BPV co-infection associated with cutaneous papillomatosis in cattle

Molecular analysis of Aspergillus section Flavi isolated from Brazil nuts

Brazil nuts are an important export market in its main producing countries, including Brazil, Bolivia, and Peru. Approximately 30,000 tons of Brazil nuts are harvested each year. However, substantial nut contamination by Aspergillus section Flavi occurs with subsequent production of aflatoxins. In our study, Aspergillus section Flavi were isolated from Brazil nuts (Bertholletia excelsa), and identified by morphological and molecular means. We obtained 241 isolates from nut samples, 41% positive for aflatoxin production. Eighty-one isolates were selected for molecular investigation. Pairwise genetic distances among isolates and phylogenetic relationships were assessed. The following Aspergillus species were identified: A. flavus, A. caelatus, A. nomius, A. tamarii, A. bombycis, and A. arachidicola. Additionally, molecular profiles indicated a high level of nucleotide variation within beta-tubulin and calmodulin gene sequences associated with high genetic divergence from RAPD data. Among the 81 isolates analyzed by molecular means, three of them were phylogenetically distinct from all other isolates representing the six species of section Flavi. A putative novel species was identified based on molecular profiles.CAPESCAPESCNPqCNPqFAPESPFAPES