A molecular technique for the detection and differentiation of D emodex mites on cats

Background D emodex gatoi causes a pruritic dermatitis in cats. Diagnosis requires the demonstration of mites using superficial skin scrapings or faecal flotation, which can be insensitive. Hypothesis/Objectives The goal of this study was to develop a molecular method to diagnose D . gatoi infection in cats and distinguish these mites from D emodex cati . Animals Fifty‐three shelter cats, 11 cats from a closed research colony and 12 privately owned cats were used. Methods D emodex gatoi and D . cati were obtained from scrapings of cat skin. The 16 S r RNA DNA was amplified by PCR , sequenced and compared with available D emodex sequences. Hair and skin samples were also collected for microscopic examination and DNA isolation. Results DNA sequences were obtained from D . gatoi and D . cati . q PCR with D . gatoi specific primers and probe amplified DNA isolated from D . gatoi and not D . cati . Conversely, D . cati q PCR primers and probe amplified D . cati DNA and not D . gatoi . Five of the shelter cats were positive for D . gatoi . Two of these cats were pruritic, and the other three were in contact with these cats. Only one cat was positive for D . gatoi on skin scraping but was negative for D . gatoi or D . cati DNA . Conclusion Results from this study show D . gatoi and D . cati to be distinct species. A novel q PCR test for the identification and differentiation of D . gatoi and D . cati was developed. Once optimized, this test could provide a valuable technique for the diagnosis of D . gatoi infection.