title: Development of a PCR technique specific for Demodex injai in biological specimens.
abstract: The identification of Demodex injai as a second Demodex species of dog opened new questions and challenges in the understanding on the Demodex-host relationships. In this paper, we describe the development of a conventional PCR technique based on published genome sequences of D. injai from GenBank that specifically detects DNA from D. injai. This technique amplifies a 238-bp fragment corresponding to a region of the mitochondrial 16S rDNA of D. injai. The PCR was positive in DNA samples obtained from mites identified morphologically as D. injai, which served as positive controls, as well as in samples from three cases of demodicosis associated with proliferation of mites identified as D. injai. Furthermore, the PCR was positive in 2 out of 19 healthy dogs. Samples of Demodex canis and Demodex folliculorum were consistently negative. Skin samples from seven dogs with generalized demodicosis caused by D. canis were all negative in the D. injai-specific PCR, demonstrating that in generalized canine demodicosis, mite proliferation is species-specific. This technique can be a useful tool in the diagnosis and in epidemiologic and pathogenic studies.
authors.affiliation: Servei Veterinari de Genètica Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Sastre
authors.forename: I
authors.initials: I
authors.lastname: Ravera
authors.forename: D
authors.initials: D
authors.lastname: Ferreira
authors.forename: L
authors.initials: L
authors.lastname: Altet
authors.forename: A
authors.initials: A
authors.lastname: Sánchez
authors.forename: M
authors.initials: M
authors.lastname: Bardagí
authors.forename: O
authors.initials: O
authors.lastname: Francino
authors.forename: L
authors.initials: L
authors.lastname: Ferrer
mesh_terms: D000818:Animals; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004283:Dog Diseases / Q000175:diagnosis* / Q000469:parasitology; D004285:Dogs; D006197:Hair / Q000469:parasitology; D008924:Mite Infestations / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D008925:Mites / Q000235:genetics*; D008969:Molecular Sequence Data; D010865:Pilot Projects; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012867:Skin / Q000469:parasitology; D013045:Species Specificity
chemical_list: D004272:DNA, Mitochondrial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S