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(1) Background: The intestinal microbiota plays an essential role in maintaining the host’s health. Dysbiosis of the equine hindgut microbiota can alter the fermentation patterns and cause metabolic disorders. (2) Methods: This study compared the fecal microbiota composition of horses with intestinal disease and their healthy counterparts living in Korea using 16S rRNA sequencing from fecal samples. A total of 52 fecal samples were collected and divided into three groups: horses with large intestinal disease (n = 20), horses with small intestinal disease (n = 8), and healthy horses (n = 24). (3) Results: Horses with intestinal diseases had fewer species and a less diverse bacterial population than healthy horses. Lactic acid bacteria, Lachnospiraceae, and Lactobacillaceae were overgrown in horses with large intestinal colic. The Firmicutes to Bacteroidetes ratio (F/B), which is a relevant marker of gut dysbiosis, was 1.94, 2.37, and 1.74 for horses with large intestinal colic, small intestinal colic, and healthy horses, respectively. (4) Conclusions: The overgrowth of two lactic acid bacteria families, Lachnospiraceae and Lactobacillaceae, led to a decrease in hindgut pH that interfered with normal fermentation, which might cause large intestinal colic. The overgrowth of Streptococcus also led to a decrease in pH in the hindgut, which suppressed the proliferation of the methanogen and reduced methanogenesis in horses with small intestinal colic.

Background Q fever, a zoonosis caused by Coxiella burnetii, has adverse effects on public health. Ticks are vectors of C. burnetii and they contribute to the transmission of the pathogen. A tool for rapid, sensitive, and accurate detection of C. burnetii from ticks is important for the prevention of Q fever. Methods Ultra-rapid real-time PCR (UR-qPCR) as a chip-based real-time PCR system was developed for the detection of C. burnetii from ticks. The UR-qPCR system was established and evaluated for the rapidity, sensitivity, and specificity of C. burnetii detection. Results C. burnetii was detected using UR-qPCR from 5644 larval, nymphal, and adult ticks from 408 pools collected from livestock and epidemiologically linked environments in two provinces, Gangwon and Jeju, in Korea. Ticks from three species were identified; Haemaphysalis longicornis accounted for the highest number, present in 333 of 408 pools (81.62%), followed by Haemaphysalis flava in 62 pools (15.19%) and Ixodes nipponensis in 13 pools (3.19%). The rapidity and sensitivity of PCR detection was demonstrated with the sufficient amplification and detection of approximately 56 copies of C. burnetii DNA with only 20 min of PCR amplification. The kappa value for the diagnostic agreement between UR-qPCR and stationary qPCR was in perfect agreement (κ = 1). PCR detection and sequencing indicated that C. burnetii was present in 5 of the 408 pools (1.23%), in which four pools contained H. longicornis and one pool contained H. flava. The infection rates of C. burnetii in the tick pools collected from Gangwon and Jeju Provinces were 1.70% and 0.58%, respectively. Phylogenetic analysis indicated a close relationship between the detected C. burnetii and those originating from goats, humans, and ticks in different countries, such as the USA, France, Germany, and Serbia. Conclusions The methods described in this study could be important for the prevention and control of Q fever in the two provinces. The UR-qPCR, with its features of mobility, sensitivity, and rapidity, is helpful for constructing early alert systems in the field for C. burnetii in ticks and could help alleviate the transmission of and economic damage due to Q fever. Graphical Abstract

Background Anaplasma spp. are tick-borne Gram-negative obligate intracellular bacteria that infect humans and a wide range of animals. Anaplasma capra has emerged as a human pathogen; however, little is known about the occurrence and genetic identity of this agent in wildlife. The present study aimed to determine the infection rate and genetic profile of this pathogen in wild animals in the Republic of Korea. Methods A total of 253 blood samples [198 from Korean water deer (Hydropotes inermis argyropus), 53 from raccoon dogs (Nyctereutes procyonoides) and one sample each from a leopard cat (Prionailurus bengalensis) and a roe deer (Capreolus pygargus)] were collected at Chungbuk Wildlife Center during the period 2015–2018. Genomic DNA was extracted from the samples and screened for presence of Anaplasma species by PCR/sequence analysis of 429 bp of the 16S rRNA gene marker. Anaplasma capra-positive isolates were genetically profiled by amplification of a longer fragment of 16S rRNA (rrs) as well as partial sequences of citrate synthase (gltA), heat-shock protein (groEL), major surface protein 2 (msp2) and major surface protein 4 (msp4). Generated sequences of each gene marker were aligned with homologous sequences in the database and phylogenetically analyzed. Results Anaplasma capra was detected in blood samples derived from Korean water deer, whereas samples from other animal species were negative. The overall infection rate in tested samples was 13.8% (35/253) and in the water deer the rate was 17.8% (35/198), distributed along the study period from 2015 to 2018. Genetic profiling and a phylogenetic analysis based on analyzed gene markers revealed the occurrence of two distinct strains, clustered in a single clade with counterpart sequences of A. capra in the database. Conclusions Anaplasma capra infection were detected in Korean water deer in the Republic of Korea, providing insight into the role of wildlife as a potential reservoir for animal and human anaplasmosis. However, further work is needed in order to evaluate the role of Korean water deer as a host/reservoir host of A. capra.

(1) Background: The large intestine of horses is an anaerobic fermentative chamber filled with fibrolytic bacteria that play essential roles in digesting and absorbing nutrients for energy production. Although Jeju horses are a prominent local breed in Korea, few studies have investigated the gut microbiota of Jeju horses, (2) Methods: This study performed sequencing of V3 and V4 hypervariable regions of the partial 16S rRNA genes obtained from horse fecal samples and compared the gut microbiota between Jeju and Thoroughbred horses. Thirty and 24 fecal samples were obtained from Jeju and Thoroughbred horses, respectively, (3) Results: The gut microbiota belonged to 23 phyla and 159 families. Firmicutes and Bacteroidetes were the most abundant and predominant phyla, followed by Verrucomicrobia, Euryachaeota, and Spirochaete. The ratio of Firmicutes to Bacteroidetes (F/B), which is known as a relevant marker of gut dysbiosis, was 1.84 for Jeju horses, whereas it was 1.76 for Thoroughbred horses. Moreover, at the genus level, 21 genera were significantly different between the Jeju and Thoroughbred horses (p &lt, 0.05), (4) Conclusions: The Thoroughbred horse’s gut microbiotas had significantly higher diversity than the Jeju horses (p &lt, 0.05). In addition, beneficial commensal bacteria that produce short-chain fatty acids thus providing a significant source of energy are also more abundant in Thoroughbred horses. These results provide novel information on the horse gut microbiota and insights for further studies related to the horse gut microbiota.

This study was performed to survey prevalence of Copper metabolism domain containing 1 (COMMD1) mutation using molecular diagnostic method in a population of Bedlington terriers in Korea. COMMD1 gene (formerly MURR1) functions as a regulator of sodium transport and copper metabolism. The deletion of exon 2 of the COMMD1 gene causes copper toxicosis in Bedlington terriers. Bedlington terriers with this autosomal recessive disorder were shown to have the elevated liver copper levels due to genetic derangement in the biliary copper excretion pathway. DNA samples were extracted from whole blood collected from 257 Bedlington terriers (109 males, 148 females) of pet dog clubs in Korea. A multiplex PCR was carried out to detect of exon 2 deletion of COMMD1 gene. In this study, it was possible to know the existence and prevalence of exon 2 deletion of COMMD1 in Bedlington terriers in Korea. Of the 257 samples, 131 (51%) were wild type homozygous for the normal COMMD1 gene, 108 (42%) were heterozygous, having both normal and mutated copy of the COMMD1 gene. The eighteen (7%) were mutant type homozygous. The results of genetic analysis could help establish proper management strategy and selective breeding program to prevent COMMD1 mutation in Bedlington terriers in Korea.

Anaplasmosis is a rickettsial zoonosis mediated by blood-sucking arthropods, such as ticks, flies, and mosquitos. Migratory birds are common hosts of ticks that are mediators of anaplasmosis, in particular, the tick infection rate in thrushes (family Turdidae) has been known to be high. The main purpose of this study is to survey the occurrence and prevalence of Anaplasma spp. from the migratory thrushes in Jeju island. We collected blood samples from 6 thrushes rescued at the Jeju Wildlife Rescue Center and from 34 wild-caught thrushes on Mara island which is a satellite island of Jeju. As a result, the nested PCR confirmed that seven out of 40 individuals (17.5%) were infected by Anaplasma spp. and all of them were identified as A. phagocytophilum based on sequences obtained from partial 16S rRNA. All the infected birds were on their northward migration in spring, our results suggest that the Turdidae family, which is a common and abundant migrant group passing through Jeju island, may act a role as active reservoir and disperser of A. phagocytophilum causing potential influx of the zoonotic pathogens from its wintering grounds in lower latitude to the mainland Korea as well as Jeju.

Siberian Roe deer which inhabits Jeju Island is unique native species. Most of all the roe deer infect a lot of ticks, which can affect its population directly and can act as a vector to spread vector-borne diseases. The purposes of this study were to identify the ticks and detect the piroplamsosis on the roe deer in Jeju island. We collected ticks and blood samples in 23 roe deer rescued and treated at the Jeju Wildlife Rescue Center. As a result, we identified the one species of ticks, Haemaphysalis longicornis in roe deer and detected the closely related to Theileria luwenshuni in all blood samples (100%) and 8 pooled ticks (34.8%). These results indicate that there may be a high prevalence particularly of T. luwenshuni infection in Jeju wild roe deer and H. longicornis is a major vector of these diseases. It suggested that Jeju roe deer may act as reservoirs for these zoonotic pathogens.

Migratory birds may disperse parasites across ecological barriers, and recent climate change may alter the pattern of ectoparasite dispersal via changed patterns of bird migration. In order to document the parasitization of migratory birds by Ixodidae ticks on Jeju Island in Korea, we examined 934 migratory birds comprising 75 species for ticks from 2010 to 2012. In total, 313 ticks were collected from 74 migratory birds across 17 avian species and identified based on morphological keys. These ticks represented six species: Haemaphysalis flava, H. formosensis, H. longicornis, H. concinna, Ixodes turdus and I. nipponensis. Of particular note was the presence of H. formosensis, a species not previously reported to have been found in Korea, and H. concinna, which had not been previously reported on Jeju Island. The dominant tick species found were H. flava (226 ticks, 72.2 %) and I. turdus (54 ticks, 17.3 %), and ground-dwelling thrushes such as Pale thrushes (Turdus pallidus; 39 birds, 52.7 %) were the most important hosts. Although H. longicornis is the most abundant and prevalent terrestrial tick on Jeju Island, the species accounted for only 3.8 % of the total ticks collected in this study, suggesting that ticks on migratory birds may differ from the local tick fauna and that exotic ticks may be introduced via migratory birds. Therefore, long-term programs for tick and tick-borne disease surveillance are recommended to understand the role of migratory animals in the introduction of exotic species and associated pathogens and in life cycles of ticks at different stages in this region.

Dear Sir: We read with interest the article by Yun and others entitled “Phylogenetic Analysis of Severe Fever with Thrombocytopenia Syndrome Virus in South Korea and Migratory Bird Routes between China, South Korea, and Japan” recently published.1 The authors proved that the severe fever with thrombocytopenia syndrome virus (SFTSV) isolated in South Korea shares a clear phylogenetic link with samples from Japan and China,1 indicating linkage of the viruses across outbreak areas in three east Asian countries separated by sea, an ecological barrier for terrestrial host and vector animals. To delineate transmission across the countries, Yun and others suggested that migratory birds play an important role in the new introduction of SFTSV in east Asia.1 We understand that they reached the conclusion based on four reasons: 1) migratory birds (especially four avian species) may carry ticks and associated pathogens, including Haemaphysalis longicornis that is known as a vector of SFTSV and has been collected from birds in Korea, 2) high-prevalence regions of SFTSV concur with geographic ranges of migratory birds in east Asia, 3) patients had no history of international travel, and 4) terrestrial mammals cannot cross the sea. Migratory birds can obviously carry parasitic arthropods and associated pathogens,2,3 and we agree with the authors' opinion that migratory birds are one of the possible pathways of SFTSV introduction.1 However, there are some key remaining questions considering migratory birds as vectors of SFTSV. First, SFTSV has a very confined distribution in the context of the spatial scale of bird migration. Migrations of birds are generally “latitudinal” movements in a predictable manner in terms of spatial and temporal scales.4,5 The regions where SFTS patients were reported lie at similar latitudes (between 30° N and 40° N) in a temperate zone, whereas many migratory birds (including the four species reported by Yun and others1) regularly exceed this range for breeding and wintering.5 If the transmission is mainly caused by bird migration, SFTS patients should be more widely (latitudinally, not longitudinally) distributed along the east Asian flyway of birds (i.e., southern China, southeast Asian countries, and the Russian Far East). In particular, migratory birds often have smaller and confined nonbreeding ranges in warm climate zones, with an increased population density during wintering periods.5 Nonbreeding areas of migratory birds at lower latitudes are potential habitats for ticks to find other host and to survive in winter. Therefore, given the lack of patient reports from northern and especially southern tips of migratory bird ranges, we believe that SFTSV can be regarded as a localized disease in terms of avian migration. In addition, we do not fully understand how the ecology (migration pattern, timing, routes, and connectivity) of migratory birds in east Asia, especially of migratory songbirds,4,5 explains the transmission of SFTSV. Second, there are clear differences between ticks infesting mammals and birds in terms of species and their life cycles. Positive SFTSVs were mainly detected in adult female ticks, especially, H. longicornis.6 However, adult stages of any tick species are rarely found on birds.3 Unlike Haemaphysalis flava that was a dominant tick collected from migratory birds3 and was free from SFTSV,6 H. longicornis was an accidental tick on birds even in H. longicornis-dominated landscapes, suggesting that ticks on birds can be very different from those on mammals.3 Indeed, SFTSVs have been mostly detected in ticks from mammals and vegetations.6 Finally, the occurrence of SFTS in patients without international travel history is consistent with infection and transmission largely caused by local mammals. Although terrestrial wild and domestic mammals carrying SFTSV cannot cross the sea in a natural condition, we cannot ignore anthropogenic factors in animal movements: increasing international trade of agricultural products and domestic and exotic animals. We may pretend that customs and quarantine services completely regulate introduction of ticks, but there are still large volumes of undetected movements of animals through illegal wildlife smuggling from China to Korea and Japan.7 Even though illegal trades are mostly focused on wildlife products such as ivory and rhino horn, increasing demand for exotic pet animals through internet-based trade enables long-distance movements of high-value wildlife and live animal smuggling in east Asia.7 We respect the conclusion of Yun and others1 that migratory birds are possible contributors to the clear phylogenetic link for SFTSV across Korea, China, and Japan. We also support the authors' suggestion that detection and isolation of SFTSV in bird ticks and serological surveillance for SFTSV in migratory birds are required.1 Nevertheless, we currently have little evidence of long-distance transmission of SFTSV through bird migration.

Lipoptena deer keds (Diptera: Hippoboscidae) are blood-sucking ectoparasites of mammals, and only one species, Lipoptena cervi (L.), has previously been reported from the Republic of Korea. A study of Siberian roe deer Capreolus pygargus Pallas on Jeju Island, south of the Korean mainland, led to the discovery of a second species of deer ked, Lipoptena fortisetosa Maa, for Korea. In total, 518 deer keds were collected from 19 adult and juvenile deer examined from May to October 2012. The infestation of all of the deer examined and the occurrence on newly born deer suggest a high prevalence and abundance of L. fortisetosa parasitizing Siberian roe deer throughout Jeju Island. This deer represents a new host species for L. fortisetosa.

The vomeronasal organ (VNO) and accessory olfactory bulb (AOB) of the Korean roe deer (Capreolus pygargus) were studied histologically to evaluate their morphological characteristics. Grossly, the VNO, encased by cartilage, has a paired tubular structure with a caudal blind end and a rostral connection through incisive ducts on the hard palate. In the VNO, the vomeronasal sensory epithelium (VSE) consists of galectin-3-positive supporting cells, protein gene product (PGP) 9.5-positive receptor cells, and basal cells. The vomeronasal respiratory epithelium (VRE) consists of a pseudostratified epithelium. The AOB strata included a vomeronasal nerve layer (VNL), a glomerular layer (GL), a mitral/tufted cell layer, and a granular cell layer. All lectins used in this study, including Bandeiraea simplicifolia agglutinin isolectin B4 (BSI-B4), soybean agglutinin (SBA), Ulex europaeus agglutinin I (UEA-I), and Triticum vulgaris wheat germ agglutinin (WGA), labeled the VSE with varying intensity. In the AOB, both the VNL and the GL reacted with BSI-B4, SBA, and WGA with varying intensity, but not with UEA-I. This is the first morphological study of the VNO and AOB of the Korean roe deer, which are similar to those of goats.

Piroplasms are tick-transmitted, intracellular, hemoprotozoan parasites that cause anorexia, fever, anemia, and icterus. Theileriosis is caused by Theileria sergenti and causes major economic losses in grazing cattle in Japan and Korea. In May 2003, we examined the antigenic diversity of the major piroplasm surface protein (MPSP) gene in 35 healthy Jeju black cattle that were born and raised at the National Institute of Subtropical Agriculture. On microscopic examination of Giemsa-stained blood smears, 9 of 35 cattle had intra-erythrocytic piroplasms. Hematological data were within normal range for all 35 cattle. Amplification of DNA from all blood samples using universal MPSP gene primers showed mixed infections with C, I, and B type Theileria spp. Type C was identified in 20 of 35 blood samples, and type B was identified in 17 samples. Allelic variation was seen in type B.