Application Analysis Of Thioredoxin Peroxidase And Sequence Analysis Of Troponin C Of Sarcoptes Scabiei

Scabies caused by Sarcoptes scabiei, which has been reported as a widespread but a neglected tropical disease that is highly contagious in conditions of overcrowding, poverty and poor hygiene. Scabies caused severe mortality resulting from the uncontrolled spread of Sarcoptes with significant impacts in terms of welfare and economic losses.1. Characterisation and analysis of thioredoxin peroxidase as a potential antigen for the serodiagnosis of sarcoptic mange by dot-ELISAIn this study, we characterised a S. Scabiei thioredoxin peroxidase (SsTPx) and evaluated a recombinant SsTPx as a diagnostic antigen in rabbits.The open reading frame of the gene encoding SsTPx was amplified and the recombinant protein was expressed in Escherichia coli cells and purified. SsTPx was localized in mite tissue by immunolocalisation using the purified recombinant protein. Serodiagnosis assays were carried out in203New Zealand White rabbit serum samples by dot-ELISA. The open reading frame (489bp) of the gene encodes an18.11kDa protein, which showed highly homology to that of Psoroptes ovis (98.77%identity) and belongs to the2-Cys family of peroxiredoxins. SsTPx was mainly distributed in muscle tissues of mites, integument of the epidermis and the anterior end of S. scabiei. Although SsTPx cross-reactivity with psoroptic mites was observed, the SsTPx dot-ELISA showed excellent diagnostic ability, with95.3%sensitivity and93.8%specificity in scabies infected and uninfected groups. This study showed that the purified SsTPx is a highly sensitive antigen for the diagnosis of scabies infection by dot-ELISA. This technique represents a rapid and convenient method for the clinical diagnosis of scabies in rabbits and may be suitable for development of as a diagnostic tool in humans in the developing world.2. Characterisation and sequence analysis of troponin C of Sarcoptes ScabieiIn this study, we cloned a S. Scabiei troponin C gene (SsTnC) and analysed the characterisation of troponin C. The open reading frame (462bp) of the gene encodes a17.62kDa protein, pI=4.15, which showed highly homology to that of Psoroptes ovis (98.7%identity) and Tyrophagus putrescentiae (95%identity). This protein contains four EF-hand and belongs to the EF-hand superfamily of calcium-binding proteins. Homology analysis demonstrated that SsTnC may be a cross-react allergen with IgE binding calcium dependence. This study is significantly useful for studying scabies and the protein function of troponin C.