Proteomic analysis of Sarcoptes scabiei reveals that proteins differentially expressed between eggs and female adult stages are involved predominantly in genetic information processing, metabolism and/or host-parasite interactions

Presently, there is a dearth of proteomic data for parasitic mites and their relationship with the host animals. Here, using a high throughput LC-MS/MS-based approach, we undertook the first comprehensive, large-scale proteomic investigation of egg and adult female stages of the scabies mite, Sarcoptes scabiei-one of the most important parasitic mites of humans and other animals worldwide. In total, 1,761 S. scabiei proteins were identified and quantified with high confidence. Bioinformatic analyses revealed differentially expressed proteins to be involved predominantly in biological pathways or processes including genetic information processing, energy (oxidative phosphorylation), nucleotide, amino acid, carbohydrate and/or lipid metabolism, and some adaptive processes. Selected, constitutively and highly expressed proteins, such as peptidases, scabies mite inactivated protease paralogues (SMIPPs) and muscle proteins (myosin and troponin), are proposed to be involved in key biological processes within S. scabiei, host-parasite interactions and/or the pathogenesis of scabies. These proteomic data will enable future molecular, biochemical and physiological investigations of early developmental stages of S. scabiei and the discovery of novel interventions, targeting the egg stage, given its non-susceptibility to acaricides currently approved for the treatment of scabies in humans. Author summary Scabies is a neglected tropical disease caused by the parasitic mite Sarcoptes scabiei. The treatment and control of scabies are challenging, as there is no vaccine and the two mostly used broad-spectrum acaricides (i.e. ivermectin and permethrin) do not kill the key developmental stage (egg) of the mite that enables the re-establishment of infection. The availability of a well-assembled genome for S. scabiei now provides a foundation to explore the molecular biology, biochemistry and physiology of this mite. Here, we characterised the first somatic proteome of key developmental stages of S. scabiei using high throughput LC-MS/MS. Bioinformatic analyses of proteomic data indicate that proteins expressed differentially between egg and female adult stages are mainly involved in biological pathways or processes, such as genetic information processing, energy (oxidative phosphorylation), nucleotide, amino acid, carbohydrate and/or lipid metabolism in the mite. These proteomic data should underpin further investigations of early developmental stages of S. scabiei with a focus on identifying novel intervention targets for scabies.