Molecular identification and phylogenetic relationship of Demodex mites based on mitochondrial 16S rDNA

BACKGROUND AND OBJECTIVE: Demodex mites are tiny parasites that live around hair follicles of mammals. The two main species of Demodex i.e. Demodex folliculorum and Demodex brevis present in humans are found near the hair follicles of eyes. The present study was to understand the presence of Demodex mites in people suffering from blepharitis in Amritsar, Punjab. MATERIAL AND METHODS: Demodex mites samples present in blepharitis patients were isolated from the eyelashes. DNA was isolated from three mites and used for PCR amplification of mitochondrial (mt) 16S rDNA. The amplified PCR product were purified and used for molecular identification. RESULTS: The amplified mt16s rDNA product was sequenced and subjected to BLAST search in the NCBI database for molecular identification. The identified mite belongs to Demodex folliculorum species. The phylogenetic tree constructed by using mt16s rDNA sequence suggests that D. folliculorum is closer to D. canis than to D. brevis. CONCLUSION: All the three isolates belong to D. folliculorum and the mitochondrial DNA 16S rDNA partial sequence is applicable for phylogenetic relationship analysis.