Molecular Characterization of Chitin Synthase Gene of Demodex canis from Mizoram, India

Canine demodicosis is a parasitic condition affecting the skin of dogs. The present study was designed to characterize chitin synthase gene of Demodex canis. The molecular technique was used for better understanding of this gene.

A total of 75 dogs which are reared as pets with or without showing any skin lesions were examined during the study period. Skin scrapings were examined by indirect method using 10% potassium hydroxide solution under 10 × microscope. DNA samples were extracted from positive skin samples and were subjected to PCR for molecular identification.

A total of 25 dogs irrespective of age, sex, breed or coat showed positive result for D. canis. The PCR revealed a single amplified product of 339 bp length which exactly matched with D. canis. The chitin synthase gene was amplified by PCR, subsequently cloned, sequenced, and compared with available data in GenBank for the particular gene of D. canis. Only one single nucleotide polymorphism (SNP) was noticed at 231 position of the chitin synthase gene sequence when compared to other isolates.

The molecular technique confirms with the morphological identity of D. canis. This report signifies the value of peculiar tool to identify 'follicular mite' even from apparently healthy skin.