Development of Semi-Nested PCR for Detecting Demodex folliculorum และ D. brevis

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ปวันรัตน์ ตรีขัน
กัญญรัตน์ กรัยวิเชียร
อัจฉรา ภูมี
เผด็จ สิริยะเสถียร

Abstract

Demodex are tiny ectoparasitic mites, live in sebaceous glands. There are only two species, D. folliculorum and D.brevis found in human. Identification between both species could be done based on the morphological appearance of the adult stage. However for other stages especially egg and nymph, they are indistinguishable, therefore it causes difficulty for epidemiology study. This present study proposed the using of molecular technique for detecting and differentiation between these two human Demodex species. Primers were designed based on 18SrRNA gene of human Demodex mites. The 18SrRNA gene is usually used for Acari arthropods evolution studies because of its high variability. Total DNA was extracted from skin samples and was used to amplify the himan Demodex mite by using Semi-Nested PCR. The PCR was able to amplify the 18SrRNA gene from both human Demodex mite species with approximately 382 bp and 317 bp for D. folliculorum and D.brevis, respectively. The data obtained from the study provides fundamental data for accurate identification of the human Demodex and therefore for futher epidemiological study in the future. In addition, this report is the first study using molecular techniques to investigate human Demodex in Thailand.

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Research Article

References

Lacy N, Kavanagh K, Tseng SC. 2009. Under the lash: Demodex mites in human diseases. Biochem (Lond) 31(4): 2-6

Baima B, Sticherling M. 2002. Demodicidosis revisited. Acta Derm Venereol 82(1): 3-6

Andrews JR. 1982. The prevalence of hair follicle mites in

Caucasian New Zealanders. N Z Med J 95(711): 451-3

Aylesworth R, Vance JC. 1982. Demodex folliculorum and Demodex brevis in cutaneous biopsies. J Am Acad Dermatol 7(5): 583-9

Damian D, Rogers M. 2003. Demodex infestation in a child with leukaemia : treatment with ivermectin and permethrin. Int J Dermatol 42(9): 724-6.

Daberta M, Witalinskib W, Kazmierskic A, Olazanowshi Z, Dabert J. 2010. Molecular phylogeny of acariform motes (Acari, Arachnida): strong conflict between phylogenetic signal and long-branch attraction artfacts. Mol Phylogenet Evol 56: 222-41.

Murrell A, Dobson SJ, Walter DE, Campbell NJH, Shao R, Barker SC. 2005. Relationships among the three major lineages of the Acari (Arthropoda: Arachnida) inferred from small subunit rRNA: paraphyly of the parasitifomes with respect to the Opilioacariformes and relative rates of nucleotide substitution, Invert Syst 19: 383-9.

Zhao Ye, Xu JR, Hu L, Wu LP, Wang ZH. 2012. Complete sequence analysis of 18S rDNA based on genomic DNA extraction from individual Demodex mites (Acari: Demodicidae). Exp Parasitol 131(1): 45-51.

T. Maniatis, E.F. Fritsch, J. Sambrook, Molecular Cloning: A Laboratory Manual, 3rd ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, 2001, 5.40.

S. Kumar, K. Tamura, M. Nei, MEGA3: Integrated software for Molecular Evolutionary Genetics Analysis and sequence alignment. Brief Bioinform, 2004, 5(2): 150-63.