Molecules with antimicrobial activity in the secretion of the arthrodial membrane gland of a harvester (Arachnida, Opiliones)

Abstract

Abstract Because of the exoskeleton, arthropods must have flexible areas to be able to move. Such regions are called arthrodial membranes and are particularly vulnerable to bacteria and fungi. Here, we analyzed the secretion in the glands underneath it in a Neotropical harvester (Arachnida, Opiliones) and tested whether it has antiseptical properties. We punctured the membrane, collected and diluted the secretion and quantified proteins and peptides in a spectrophotometer. We also fractionated and analyzed the samples in reversed-phase high-performance liquid chromatography (RP-HPLC) and then incubated the treated fractions and determined growth inhibition by measuring absorbance. The secretions resulted in 42 fractions, among which two had activity against the Gram-positive bacteria Micrococcus luteus and against the yeast Candida albicans. The low concentrations at which the secretions were active are relevant from a biotechnological point of view. For the animals, the secretions possibly prevent infections, including when they are attacked in these regions by predators that pick that spot to bite.