Assessment of antimicrobial and immunomodulatory activities of termite associated fungi, Termitomyces clypeatus R. Heim (Lyophyllaceae, Basidiomycota)

Abstract

Background: Termitomyces clypeatus (T. clypeatus) is an edible mushroom specie which grows in various areas in Cameroon. It is indicated by several healers in treatment of several infectionsand is frequently used for this purpose. However, no study has been reported on its antibacterial and immunomodulatory activities which were the aim of this study. Methods: Disc diffusion method was used to appreciate the bactericidal activity against 4 bacteria and 2 yeast species. The immunomodulatory activities were assessed in mice, where the extract was administered by gavage and as supplement in the feed. The treatment was done for 10 days. Delayed type hypersensitivity test was carried out to assess the cell mediated immune response while the effect on humoral immunity was evaluated using hemagglutination assay and mice lethality test.. The body weight was also recorded in mice used for delayed hypersensitivity. Results: It was found that extract of T. clypeatus highly inhibited the growth of bacteria and yeast at different ratios compared to the medium (P < 0.05). The extract of T. clypeatus has reversed the immunosuppressed effects of dexamethasone on antibody formation. In addition, it significantly decreased of the mice lethality rate in mice infected by Pasteurella multocida (P < 0.05). Administration of T. clypeatus also significantly increased the delayed type hypersensitivity response in healthy and dexamethasone immunosuppressed mice (P < 0.05), but it significantly reduced the body weight of mice after 10 days. Conclusion: The results provided basic information demonstrating the antibacterial activity and immunostimulatory activity of T. clypeatus on both cell-mediated and humoral immunity.

The chemical ecology of the fungus-farming termite symbiosis

“…A series of defences helps secure that fungus gardens are diseasefree, including avoidance of antagonists by the termites, 34 burial of unwanted fungi, 36 and utilisation of antimicrobial compounds of termite, Termitomyces, and bacterial origins. 23,24,37 3 Natural products reported from the termite symbiosis Our extensive literature survey from 1972 to 2020 revealed that 375 natural products have been identied in the fungus-farming termite symbiosis. Subsequent literature screening of hundreds of scientic papers allowed us to generate a searchable database of all compounds (ESI, Table 1 †) that includes molecular formulas, mass, compound name, natural product class, the producing organism and termite host (when known), geographic origin of discovery, method of identication, and known bioactivities or lack thereof.…”

“…83 It is thus conceivable that combinations of multiple compounds play a signicant role in termite nest defence through contributions to the antimicrobial activity observed in Termitomyces. 24,84 Phenolic compounds are found widely throughout the plant kingdom, and it is possible that the phenolic compounds identied in Termitomyces could have been synthesized and absorbed from plants. However, the Shikimate pathway has been correlated to the presence of phenolic compounds in fungi 85,86 and a recent study showed that despite avonoids being well-known plant metabolites, all genes and protein sequences associated with the biosynthesis of avonoids can be found in some fungi.…”

“…A series of defences helps secure that fungus gardens are disease-free, including avoidance of antagonists by the termites, 34 burial of unwanted fungi, 36 and utilisation of antimicrobial compounds of termite, Termitomyces , and bacterial origins. 23,24,37…”

“…21 Remarkably, the symbiosis does not appear to suffer from specialised diseases despite maintaining fungal cultivars in monoculture within colonies that can become decades old. 11,15 This suggests the presence of very effective defences, which extend to the use of natural products produced by the insect host [22][23][24] and fungal and bacterial symbionts. 25,26 However, despite receiving substantialand increasingattention, we lack a comprehensive overview of the natural products that have been identied in the fungus-growing termite symbiosis and reection on their putative functions.…”

A Systematic Review of Biodiversity and Conservation of Indigenous Mushrooms (Basidiomycotina, Ascomycotina) of Central Africa Countryside: Uses, Distribution and Checklists

“…(Russulales) reported in the reserve could be studied for production of industrial and bioactive agents. Furthermore, Jumbam et al [28] reported that only three records of the saprotrophic genus Hericium (in family Hericiaceae of Russulales) are available from Africa.…”