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Aims: Three conventional methods and a multiplex PCR procedure with a set of four primers (Quadruplex‐PCR) were used to differentiate between aflatoxin‐producing and non‐producing strains of the Aspergillus flavus group. Methods and Results: By combining sets of primers for aflR, nor‐1, ver‐1 and omt‐A genes of the aflatoxin biosynthetic pathway, Quadruplex‐PCR showed that aflatoxinogenic strains gave a quadruplet pattern, indicating the presence of all the genes involved in the aflatoxin biosynthetic pathway which encode for functional products. Non‐aflatoxinogenic strains gave varying results with one, two, three or four banding patterns. A banding pattern in three non‐aflatoxinogenic strains resulted in non‐differentiation between these and aflatoxinogenic strains. Conclusion and Significance and Impact of the Study: Because conventional methods are time‐consuming, further studies are needed to develop a rapid and objective technique that permits complete differentiation between aflatoxin‐producing and non‐producing strains of the A. flavus group.

Candida africana is a recently described opportunistic yeast pathogen that has been linked to vaginal candidiasis. This yeast was first described, in 1995, as atypical chlamydospore-negative Candida albicans strain, and subsequently proposed as a new Candida species on the basis of morphological, biochemical and physiological characteristics clearly different from those of typical C. albicans isolates. Phylogenetic studies based on the comparison of ribosomal DNA sequences demonstrated that C. africana and C. albicans isolates are too closely related to draw any conclusions regarding the status of a new species. Therefore, on the basis of these studies, some authors considered C. africana as a biovar of C. albicans even if genetic differences may be found if additional regions of genomic DNA are sequenced. The taxonomic situation of C. africana and its phylogenetic relationship with other Candida species is still controversial and remains, at present, a matter of debate. Our goal is to review the current knowledge about C. africana and highlight the development of rapid and accurate tests for its discrimination from C. albicans, Candida dubliniensis and Candida stellatoidea. Furthermore, through the analysis of literature data, we have found that C. africana has a worldwide distribution and a considerable number of features making its study particularly interesting.

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In this study, we investigated phylogenetic relationships among Italian Sporothrix schenckii isolates, by comparing their partial calmodulin sequences. In this analysis, we used 26 environmental strains of S. schenckii, plus two autochthonous clinical isolates. The results showed that our clinical strains grouped with S. schenckii sensu stricto isolates, whereas all 26 environmental isolates co-clustered with Sporothrix albicans (now regarded as a synonym of Sporothrix pallida), a non-pathogenic species closely related to S. schenckii. Furthermore, the group of environmental strains was found to be quite heterogeneous and further subdivided into two subgroups. The data reported here also showed that molecular methods, for specific identification of S. schenckii, developed before the description of its closely related species should be used with caution because of the possibility of false positive results, which could lead to inappropriate antifungal therapy. This study improves our understanding of the distribution of these new closely related Sporothrix species which also showed significant differences in antifungal susceptibilities.