INVOLVEMENT OF TWO GENETIC LINEAGES OFSARCOPTES SCABIEIMITES IN A LOCAL MANGE EPIZOOTIC OF WILD MAMMALS IN JAPAN

Abstract

Similar to wild mammals on the continents, mange caused by the mange mite, Sarcoptes scabiei (Acari: Sarcoptidae) is spreading in wild mammals in most of Japan. We collected crusted or alopetic skin from 120 raccoon dogs (Nyctereutes procyonoides viverrinus), three raccoons (Procyon lotor), six Japanese badgers (Meles anakuma), one Japanese marten (Martes melampus), one stray dog (Canis lupus familiaris), four wild boars (Sus scrofa leucomystax), and one Japanese serow (Capricornis crispus), mainly in an area where mangy wild animals have been increasingly noted in the past 4 yr. The second internal transcribed spacer (ITS2) region of the ribosomal RNA gene and the partial 16S and cytochrome c oxidase subunit I (cox-1) genes of mitochondrial DNA (mtDNA) were characterized in these skin samples. The ITS2 sequencing (404 base pairs [bp]) identified the causative mite for mangy skin lesions of 128 animals as S. scabiei, regardless of host origin. The cat mite (Notoedres cati) was the cause in one raccoon dog and one raccoon. Most mites had almost identical ITS2 nucleotide sequences to those recorded in a variety of mammals worldwide. Partial 16S and cox-1 fragments of mtDNA amplified and sequenced successfully (331 bp and 410 bp, respectively) showed an identical nucleotide sequence except for one site (C vs. T) for the former and four sites (G, C, C, C vs. A, T, T, T, respectively) for the latter fragment. These substitutions were always synchronized, with the two mitochondrial DNA haplotypes (i.e., C/GCCC and T/ATTT) appearing to separately colonize in geographic units. The T/ATTT haplotype fell into a clade where animal-derived mites worldwide dominated, whereas the C/GCCC haplotype formed a geographic branch unique to Japanese isolates. These results suggest that heterologous populations of monospecific S. scabiei are expanding their populations and distributions regardless of host species in an apparently local mange epizootic of wild mammals in Japan.

The emergence of sarcoptic mange in Australian wildlife: an unresolved debate

“…All studies were attempting to answer whether mites were genetically different depending on the host they were infecting and/or whether biogeographical separation existed. General conclusions from all gene targets include that (i) microsatellites identify distinctive host separation [ 35 , 47 , 49 – 52 ], (ii) COX1 and 16S are consistent with host and location separation, with human specific mites indicating higher species separation based on location according to COX1 [ 32 , 35 , 36 , 42 , 53 , 54 ], (iii) ITS-2 and 12S should only be used for S. scabiei identification and that a single species of mite infects all animals and humans [ 32 , 34 , 37 , 38 , 42 , 53 , 55 , 56 ], and (iv) genes encoding for glutathione S-transferase-1 and voltage-sensitive sodium channels (GST1 and VSSC, respectively) might be a good indicator for host-related variation and resistance [ 57 ]. Interestingly, Erster et al [ 57 ] found that COX1 did not play a role in mite host-specific separation in this particular study, which is contrast to other COX1 studies [ 32 ].…”

“… ITS-2: No host or geographical preference. Makouloutou et al (2015) [ 54 ] Canis lupus familiaris (Japan) Capricornis crispus (Japan) Martes melampus (Japan) Meles anakuma (Japan) Nyctereutes procyonoides viverrinus (Japan) Procyon lotor (Japan) Sus scrofa leucomystax (Japan) ITS-2: Only good for identification of causative agent. 16S: Showed minor genetic differences regardless of hosts in Japan.…”

Mitochondrial genome sequencing reveals potential origins of the scabies mite Sarcoptes scabiei infesting two iconic Australian marsupials

“…The 12S rRNA gene is highly conserved and does not discriminate well between host species infected by S. scabiei , although some studies have used it for this purpose [ 19 , 21 ]. The 16S rRNA gene is less conserved, though is also limited in its ability to identify genetic distinctions among S. scabiei mites separate hosts or locations [ 22 , 23 ]. cox1 is the most variable of the three genes, with greater power to distinguish between mites from different host species [ 20 , 24 – 26 ].…”

“…cox1 is the most variable of the three genes, with greater power to distinguish between mites from different host species [ 20 , 24 – 26 ]. Nuclear markers have also been investigated including the use of microsatellites [ 27 – 30 ] and phylogenetic analysis of ITS-2 gene sequences [ 23 , 25 , 31 – 34 ]. The latter studies concluded that S. scabiei was a single heterogeneous species with a low level of genetic diversity [ 23 , 25 , 31 – 34 ].…”

First detection of Sarcoptes scabiei from domesticated pig (Sus scrofa) and genetic characterization of S. scabiei from pet, farm and wild hosts in Israel

“…In our study, the condition and the number of the individual samples from which DNA was extracted did not allow high resolution morphological examination. Recent studies on S. scabiei genetics used several markers, both nuclear and mitochondrial (Alasaad et al 2009;Amer et al 2014;Makouloutou et al 2015;Zhao et al 2015). It was concluded that while ITS-2 sequence variations are not linked to host or geographic differences, variations in mitochondrial markers may better reflect population differences stemming from host preference or geographic location.…”