Interaction between bacteria and amphibian skin: morphological and immunological aspects

Abstract

Currently, there are about of 6.638 species of amphibians described worldwide. All the species present in common a highly glandular skin that is usually humid due to the secretion of mucopolysaccharide compounds on its surface. This moisturized surface provides a suitable environment to the growth of several microorganisms on the amphibian skin. While many of these microorganisms live in balance presenting a beneficial commensal association, others are potential pathogens that mainly affect the wild amphibian populations. Recent evidences suggest that the normal microbiota can be important in the prevention of diseases in amphibians, and that in its absence, the hosts are more susceptible to the infection caused by pathogens and the development of diseases. Despite the great interest towards the amphibians in terms of biodiversity, environment and bioprospection, little is known on the association of microorganisms with amphibian skin and their characteristics. Therefore, we aim to analyze the interaction among some species of bacteria and amphibians, focusing on the dynamics of this association, and taking in account the biology and natural history of representative species of amphibians. For this reason, these interactions between bacteria and different species of amphibians (in natural and experimental infection conditions) will be studied by means of microbiological, histological, ultra-structural, histochemical and cytochemical methods. The results obtained from these experiments will be also analyzed taking in account the habitat of each one of the species of amphibians. In addition, aiming a preliminary view of the immunological aspects of this interaction, the presence of inflammatory cytokines in the amphibian skin in response to a bacterial infection will also be studied. (AU)