Molecular characteristics and serodiagnostic potential of chitinase-like protein from Sarcoptes scabiei

// Ran He 1, * , Nengxing Shen 1, * , Haojie Zhang 1, * , Yongjun Ren 2 , Manli He 1 , Jing Xu 1 , Cheng Guo 1 , Yue Xie 1 , Xiaobin Gu 1 , Weimin Lai 1 , Xuerong Peng 3 and Guangyou Yang 1 1 Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, China 2 Sichuan Animal Sciences Academy, Sichuan Chengdu, China 3 Department of Chemistry, College of Life and Basic Science, Sichuan Agricultural University, Wenjiang, China * These authors contributed equally to this work Correspondence to: Guangyou Yang, email: guangyou1963@aliyun.com Keywords: chitinase-like protein, Sarcoptes scabiei, enzyme-linked immunosorbent assay, immunolocalization, intradermal skin test Received: May 23, 2017      Accepted: September 03, 2017      Published: September 19, 2017 ABSTRACT Scabies, caused by the mite Sarcoptes scabiei , is an allergic skin disease that affects millions of people and other mammals worldwide. This highly contagious parasitic disease is among the top 50 epidemic disease and is regarded as a neglected tropical disease. Diagnosis of scabies is difficult in the early stage, and the pathogenesis of scabies is not currently clear. Here, we expressed, identified and located the chitinase-like protein of S. scabiei (SsCLP), and evaluated its potential as an early-stage diagnostic antigen for rabbit scabies. Indirect ELISA using recombinant SsCLP (rSsCLP) exhibited diagnostic sensitivity of 94.4% (17/18) and specificity of 86.7% (26/30). Early diagnostic test after artificial infection of rabbits with S. scabiei for 1 week showed a positive detection rate of 96.7% (29/30). Immunolocalization assays showed that fluorescence signals were localized on the surface of mites and, in infected rabbits, were observed in keratinized skin and embedded mites. Intradermal skin tests of rabbits by injecting rSsCLP showed a wheal, flare and erythema reaction. These results suggest that S. scabiei chitinase-like protein is conducive to host invasion, participates in inducing the allergic response of the host, and is an effective antigen for the diagnosis of S. scabiei .