Medicines developed from natural sources are a frequent target for the research and discovery of antimicrobial compounds. Discovering of penicillin in 1928 was a motive to explore of nature as a source of new antimicrobial agents. Fungi produce a diverse range of bioactive metabolites, making them rich source of different types of medicines. The purpose of this paper was to review studies on antibacterials from terrestrial Aspergillus published exclusively during 1942-2018, with emphasis on their antibacterial activities, structures, and mechanisms of action if present. According to the results from different studies in the world, large number of compounds and extracts showed different activities against different bacterial species, including Gram-positive and Gram-negative bacteria. The most prominent result was that of the compound CJ-17,665, isolated from A. ochraceus, showing good activity against multi-drug resistant Staphylococcus aureus, which is well-recognised to be one of the most important current public health problem. These findings may motivate scientists to undertake a project that may result in the development of novel antibacterial drugs from terrestrial-derived Aspergillus spp., although further toxicity assays (in vivo) must be performed before their application.

This review presents several types of metabolites produced by the most common fungal pathogens and their roles in fungal pathogenesis. Toxic metabolites from toxigenic fungi include compounds such as aflatoxins, trichothecenes, ochratoxins, fumonisins, zearalenone and ergot alkaloids, which display hepatotoxicity, nephrotoxicity, neurotoxicity and genotoxicity. The ability of fungi to produce and elaborate hydrolytic enzymes is associated with virulence of several pathogenic fungi. The biogenesis of siderophores is investigated as it is a mechanism of iron acquisition. In particular, these metabolites act as iron chelators and storage compounds to support pathogenic fungi to survive in mammalian hosts whose iron homeostasis is strictly regulated and prevent the formation of free radicals which are formed by free iron. Melanins clearly promote infectivity in a number of species of fungal pathogens. They interfere with oxidative metabolism of phagocytosis making the fungus relatively resistant to phagocyte attack. Several metabolies such as pullulan, mannitol, β-(1,3)-glucan, hem-binding proteins, estrogen-binding proteins, farnesol, agglutinin-like sequence proteins, glucuronoxylomannan and others also have advantages in fungal pathogenicity. The identification of fungal metabolites involved in pathogenesis, and recognition of mechanisms of pathogenesis may lead to development of new efficient anti-fungal therapies.

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Introduction Intestinal parasitic infections (IPIs) among schoolchildren are important public health problem, especially in developing countries, and monitoring of such infections and associated risk factors are necessary for intervention strategies. In line with this view, the aim of this study was to determine the prevalence of IPIs and associated risk factors among schoolchildren in Ibb governorate, southwest Yemen. Methods A cross-sectional study was carried out during February to April 2020 on 600 schoolchildren selected from 6 districts of Ibb governorate. Fecal specimens were examined using saline and iodine wet mount and formal-ether concentration techniques. Socio-demographic data were collected using pre-designed, structured questionnaires. The results were analyzed using SPSS for Windows version 25 (SPSS Inc., Chicago, IL, USA). Results Out of 600 participants, the overall prevalence of IPIs was 66.3% (398/600). The prevalence rate of protozoan infections (56.3%, 338/600) was largely higher than helminthic infections (10%, 60/600). The most common intestinal parasite was E. histolytica / dispar (28.5%, 171/600). S. mansoni infection showed higher infection rate in males (5.3%) than in females (0.4%), with statistically significant difference (P = 0.001). Univariate analysis showed that the age was only significantly associated with protozoan infections, with statistically significant differences (P = 0.002). Regarding to clinical symptoms, the presence of IPIs was significantly associated with diarrhea, dysentery, and abdominal pain. Conclusion The present study revealed that there was a relatively high prevalence of IPIs, especially protozoan parasites, in schoolchildren of the study area, with E. histolytica / dispar being the most prevalent parasite. The results showed that age was only significantly associated with IPIs. According to the results of this study, IPIs are still among the main public health problems in the study area. Thus, effective prevention and control strategies are important to reduce the incidence of IPIs in this area of the country.