Generation and characterization of cDNA clones from Sarcoptes scabiei var. hominis for an expressed sequence tag library: identification of homologues of house dust mite allergens.

Molecular studies on scabies, a disease of considerable human and veterinary significance, have been limited because of the difficulty of obtaining the causative organism Sarcoptes scabiei, the "itch mite." We have used skin from the bedding of crusted scabies patients as a source of mites for the construction of libraries of cDNAs from S. scabiei var. hominis in the bacteriophage lambda vector lambdaZAP express. Sequences of 145 clones established that the libraries predominantly contain sequences from S. scabiei, enabling a major sequencing program to begin. Among those sequenced to date, cDNAs encoding S. scabiei homologues of 3 house dust mite allergens-the M-177 apolipoprotein, glutathione S-transferase, and paramyosin--were identified. The availability of cDNA libraries from S. scabiei var. hominis and S. scabiei var. vulpes and the emerging public sequence databases from both opens up new possibilities in scabies research.