ABSTRACT
Alternaria species are common saprophytes or pathogens of a wide range of plants pre- and post-harvest. This review considers the relative importance of Alternaria species, their ecology, competitiveness, production of mycotoxins and the prevalence of the predominant mycotoxins in different food products. The available toxicity data on these toxins and the potential future impacts of Alternaria species and their toxicity in food products pre- and post-harvest are discussed. The growth of Alternaria species is influenced by interacting abiotic factors, especially water activity (a(w)), temperature and pH. The boundary conditions which allow growth and toxin production have been identified in relation to different matrices including cereal grain, sorghum, cottonseed, tomato, and soya beans. The competitiveness of Alternaria species is related to their water stress tolerance, hydrolytic enzyme production and ability to produce mycotoxins. The relationship between A. tenuissima and other phyllosphere fungi has been examined and the relative competitiveness determined using both an Index of Dominance (I(D)) and the Niche Overlap Index (NOI) based on carbon-utilisation patterns. The toxicology of some of the Alternaria mycotoxins have been studied; however, some data are still lacking. The isolation of Alternaria toxins in different food products including processed products is reviewed. The future implications of Alternaria colonization/infection and the role of their mycotoxins in food production chains pre- and post-harvest are discussed.
Subject(s)
Alternaria , Edible Grain , Cottonseed Oil , Dehydration , Ecology , Fabaceae , Fungi , Hydrogen-Ion Concentration , Solanum lycopersicum , Mycotoxins , Physiology , Prevalence , Sorghum , ToxicologyABSTRACT
Alternaria species are common plant pathogens and saprophytic fungi. Cutaneous alternariosis is rare and an opportunistic infection in both healthy and immunosuppressed hosts. We report a case of cutaneous alternariosis developed in a 60-year-old female with iatrogenic Cushing syndrome. She had several various sized confluent suppurative ulcers on erythematous plaques on the both forearm clinically. Histology showed mixed-cell granulomatous infiltration with epithelioid cells, lymphocytes, neutrophils and a few plasma cells in the dermis. Many branching septate hyphae and spores were noted within the granulomatous tissue stained with PAS. A fungal culture from biopsy specimen revealed Alternaria species; pigmented hyphae and cornidia which had both transverse and longitudinal septae. The cutaneous lesions treated with terbinafine, 250 mg daily, for 3 months and 1 year later there is no evidence of recurrence.
Subject(s)
Female , Humans , Middle Aged , Alternaria , Alternariosis , Biopsy , Cushing Syndrome , Dermis , Epithelioid Cells , Forearm , Fungi , Hyphae , Immunocompromised Host , Lymphocytes , Neutrophils , Opportunistic Infections , Plants , Plasma Cells , Recurrence , Spores , UlcerABSTRACT
Alternaria species are common plant pathogens and saprophytic fungi. Cutaneous alternariosis is rare and an opportunistic infection in both healthy and immunosuppressed hosts. We report a case of cutaneous alternariosis developed in a 60-year-old female with iatrogenic Cushing syndrome. She had several various sized confluent suppurative ulcers on erythematous plaques on the both forearm clinically. Histology showed mixed-cell granulomatous infiltration with epithelioid cells, lymphocytes, neutrophils and a few plasma cells in the dermis. Many branching septate hyphae and spores were noted within the granulomatous tissue stained with PAS. A fungal culture from biopsy specimen revealed Alternaria species; pigmented hyphae and cornidia which had both transverse and longitudinal septae. The cutaneous lesions treated with terbinafine, 250 mg daily, for 3 months and 1 year later there is no evidence of recurrence.