Obihiro University of Agriculture and Veterinary Medicine
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博物館へのCOVID-19 流行の中期的影響：リトアニア共和国の事例
Get PDFapplication/pdfA couple of years after 2020, the historical pandemic affected museums worldwide. Thus, museum professionals has been challenging to return the situation to usual, and their efforts seem adequate. Still, it is also relevant to study what was and has been the effect of the pandemic. This article explores three aspects of the transition: the continuance of museums and the fluctuation of their on-site and online visitors. Therefore, the author selected three indicators for the analysis; the number of museums to examine the continuance of museums, the number of annual visitors of each institution to investigate the fluctuation of their on-site visitors, and the number of annual accesses to the website of each institution to examine the fluctuation of their online visitors. In addition, to explore the changes between pre- and post-COVID times, the author adopted data from 2017 to 2022 for the analysis. This article addresses the case of museums in the Republic of Lithuania since there is sufficient official statistical data for analysis of the three aspects written above. Descriptive statistical analyses indicated three traits of the transition. Firstly, the number of museums slightly increased, and no museum disappeared for the sake of the pandemic. Secondly, the number of on-site visitors once dropped in 2020 but recovered to pre-COVID times. Lastly, the number of website access has continuously decreased since 2017, and perhaps websites are no longer an information source for museums’ audiences. Further research may include long-term perspectives and adopt more varied methods to investigate post-COVID museums more in-depth.journal articl
Molecular Detection and Identification of Piroplasm in Cattle from Kathmandu Valley, Nepal
Get PDFapplication/pdfBackground: Tick-borne protozoan parasites (TBPPs) cause significant problems for domestic animals’ health in Nepal. TBPPs are routinely diagnosed by labor-intensive blood smear microscopy. In Nepal, there are some reports of Babesia and Theileria in cattle, although species identification is rarely performed. Therefore, we performed conventional nested PCR (nPCR) followed by sequence analysis to identify TBPP species infecting cattle in Nepal. Methods: One hundred and six blood samples were collected from cattle in the Kathmandu Valley. Thin blood smears were prepared for microscopic examination. Parasite DNA was extracted from the blood, and nPCR and sequencing were performed to identify the TBPPs present. Results: Among the 106 samples, 45 (42.5%) were positive for piroplasm (Babesia spp. and Theileria spp.) via microscope observation and 56 (52.8%) samples were positive via nPCR. The obtained PCR products were used for direct sequencing, and we identified the species as B. bigemina, B. bovis, T. annulate and T. orientalis. Phylogenetic analyses showed that the B. bovis, B. bigemina and T. orientalis sequences from this study belonged to each species clade. On the other hand, T. annulate was divided into two clades in the analysis, and our T. annulate sequences were also divided in these two clades. The piroplasm-positive cattle showed lower hemoglobin and red blood cells than healthy cattle. Conclusions: To the best of our knowledge, this study is the first to apply molecular detection and species determination of TBPPs in cattle in Nepal. The results of this study may be used as a starting point for the development of successful TBPP surveillance and prevention programs in Nepal. © 2023 by the authors.journal articl
Molecular detection of Rickettsia africae from Amblyomma hebraeum ticks in Mafikeng city of North West Province, South Africa
Get PDFapplication/pdfRickettsia africae causes zoonotic African tick bite fever, which is a disease of “One Health” importance. There have been reported cases of tourists from Europe and Asia who have been bitten by ticks whilst visiting South Africa's nature reserves, and on their return to their countries, the display African Tick Bite Fever sickness. Hence, the aim of this study was to determine the occurrence of Rickettsia africae in Amblyomma hebraeum ticks infesting livestock in the North West Province. A total of 358 A. hebraeum ticks were collected from 60 ruminants (cattle, sheep and goats) in Mafikeng City of North West Province, South Africa. Ticks were identified morphologically and further confirmed by sequencing of their ITS2 gene. DNA was extracted from 60 pools of ticks which consisted of 5–6 adult ticks that were from the same ruminant host. Infections with Rickettsia spp. were found in 48%, 40%, and 32% of cattle, sheep, and goats, respectively, in amplification by PCR using the ompA gene. The ompA gene sequences showed that the Rickettsia spp. were identified as R. africae. Although the animals from whom the ticks were collected did not exhibit any clinical symptoms, it is well recognised that R. africae is a disease with significant zoonotic potential. Thus, it is important to use the “One Health” approach to formulate prevention and control measures for this pathogen for animal and human health as well as the tourism sector due to the ecotourism importance of the resultant disease. © 2023 The Authorsjournal articl
自動動画撮影カメラを用いた地表性ネズミ類の個体追跡サンプリング法の有用性
Get PDFapplication/pdf野生哺乳類の生態を理解するためには、その移動行動を把握することが重要である。大型及び中型の哺乳類では、近年のバイオロギング技術の発達に伴い、個体の移動経路を追跡することが可能である。しかしながら、ネズミ類等の齧歯類では多くの種が小型かつ夜行性であることから、その移動行動を野生状態で一定時間継続して観察することは困難である。そこで本研究では、自動動画撮影カメラ（以下、カメラ）を用いた個体追跡サンプリング法が、地表性小型齧歯類の行動観察に有用であるかを検討することを試みた。約9 m2 の範囲の地表（区画）を撮影可能なカメラを調査区内に10 台連ねて設置し、約90m2 の面積を撮影域として、ネズミ類の移動経路及び生息地の利用パターンを一定範囲で追跡観察することを試みた。調査は2022 年5 月～ 10 月の非積雪期に、北海道足寄町の九州大学北海道演習林内の天然生広葉樹林で行った。撮影された動画データでは、主にアカネズミ属及びヤチネズミ属を確認することができた。分析の結果、複数台のカメラによる区画をまたいだネズミ個体の連続追跡はできなかったが、各カメラの撮影範囲内において、ネズミ類によって繰り返し利用される移動経路の存在が確認された。また、移動行動の他にも堅果を摂食する行動、営巣用資源（落葉）・堅果の運搬行動、及び仔を運搬するような行動、さらに堅果の埋蔵行動を確認することができた。特に仔を運搬するような行動及び堅果の埋蔵行動（埋蔵した堅果の上を落葉で覆うような行動）は、これまでの野外観察からは報告されていないネズミ類の行動である。これらの結果から、直接観察が難しいネズミ類の調査へカメラの適用が進展することで、その行動学的情報をさらに収集することができる可能性が示された。To understand the ecology of mammals, their movement behaviors must be studied. In large- and medium-sized mammals, improved biologging techniques allow us to track each individual and record their movement pathways. However, recording the movement behavior of wild murids for a certain period, is difficult, owing to their small body size and nocturnal characteristics. Therefore, in the present study, we tested whether automatic video cameras were useful for tracking terrestrial murids. This study was conducted from May 16 to October 12, 2022, at the Hokkaido Research Forest of Kyushu University, Ashoro, Hokkaido, Japan. We established a series of ten cameras that can each capture a ground surface area of 9 m2, covering an area of approximately 90 m2 in the study cite. We captured a total of 158 Apodemus individuals and a total of 18 Craseomys individuals, although identifying their exact species names was difficult. Unfortunately, tracking the movement of the murids over long distances was difficult; however, we observed movement pathways that were repeatedly used by the murids. In addition, we successfully observed murid behaviors such as carrying nesting materials (leaves), acorns, and probably young ones. Moreover, we recorded the acorn burying behavior of the Apodemus species. These results suggest that the using video cameras when investigating murids can help collect more behavioral information in the future.departmental bulletin pape
First Kiso pony foal produced via transfer of long-distance shipped fresh embryo to Hokkaido native pony
Get PDFapplication/pdfJapanese native horses, which consists of 8 breeds, are threatened with extinction. Embryo transfer (ET) is used to reproduce endangered animals in various mammalian species. We aimed to perform ET using native ponies from Kiso and Hokkaido as donors and recipients, respectively. ET operation included long-distance transport of non-cryopreserved embryos from Nagano Prefecture to Hokkaido. Embryos were transported 1500 km over 9 h in a container maintained at 22°C. After transferring two embryos to two recipients, one mare delivered a healthy live foal. These results demonstrated that reciprocal ET with long-distance transportation of fresh embryos between the isolated breeds may allow for the proliferation of Japanese native horses.journal articl
Trypanosoma equiperdum ⾃然感染⾺および実験感染マウスに関する病理学的研究
Get PDF帯広畜産大学博士（獣医学）2022application/pdfDourine is a protozoan disease in equids caused by infection with Trypanosoma equiperdum. T. equiperdum is transmitted by coitus, and affected horses manifest various
clinical signs during the long-term clinical course of 1-2 months to several years. Since the mortality of affected horses is more than 50%, dourine causes significant economic damage to horse industry in developing countries. However, there is lack of studies aimed to elucidate the parasite strategies of T. equiperdum and the pathogenesis of various clinical signs and lesions observed in dourine affected horses. Therefore, the pathogenesis of dourine remains largely unknown. In human sleeping sickness caused by T. brucei rhodesiense and T. b. gambiense, pathological and parasitological studies of spontaneous cases and various multi-faceted murine infection models have been contributed to elucidate the pathogenesis of human sleeping sickness. The objective of the present studies was to elucidate the pathogenesis of dourine and the parasitic strategy of T. equiperdum, which remains largely unknown.
In chapter I, I conducted immunohistochemical study of peripheral neuritis observed in dourine affected horses. In chapter II and III, I have established mouse infection models that reproduce some of the clinical signs and histological lesions observed in dourine affected horses. In chapter IV, I attempted to reproduce the sexual transmission of T. equiperdum in mice. In chapter I, I focused on neurological signs of dourine, which observed in late to terminal stage of infection. Previous studies suggested that the neurological signs were probably attributed to the peripheral neuritis, however, the precise pathogenesis of the neuritis remains unclear. In this chapter, I identified the types of inflammatory cells infiltrating systemic peripheral neuritis observed in 4 dourine affected horses by immunohistochemistry, and compared those immunohistochemical natures between clinical stages of the affected horses (early, late, or terminal stage). As results, the infiltrating inflammatory cells were T lymphocytes, B lymphocytes, and macrophages, regardless of the clinical stage. Among T lymphocytes, CD8+ T lymphocytes were more predominant than CD4+ T lymphocytes. In macrophages, M2 macrophages were more predominant subtype than M1 macrophages. Those results indicated that the neuritis have natures of chronic inflammation. Also, those features were identical in all affected horses classified into early, late, or terminal stage. Therefore, while the neurological signs of dourine are clinically recognized in the late or terminal stage, peripheral neuritis may have already occurred in the acute stage of infection.
In chapter II, I have attempted to establish a mouse infection model that reproduces clinical signs and lesions including peripheral neuritis observed in dourine affected horses. Since mice are not susceptible to almost all T. equiperdum strains, mouse infection model of dourine has not been established. I infected female mice with T. equiperdum IVM-t2 strain, which is a newly isolated from dourine affected stallion in Mongolia, by intraperitoneal administration, and examined systemic organs of infected mice histopathologically. As results, infected mice developed periodic parasitemia during the experimental period (60 days). In those infected mice, peripheral neuritis similar to that found in affected horses were not observed. However, vaginitis and dermatitis with histological features similar to those found in affected horses were observed. Based on those findings, female mice infected with T. equiperdum IVMt2 strain may be a valuable experimental model for future pathological and parasitological research.
In Chapter III, I focused on male genital lesions in mice infected with T. equiperdum IVM-t2 strain intraperitoneally, and examined the reproductive organs of infected male mice histopathologically. Also, since anemia is one of the characteristic clinical signs of dourine, I also examined the hematocrit value of infected mice. As results, infected mice were persistently anemic throughout the experimental period (38 days). Histopathologically, epididymitis with histological features similar to those in dourine affected stallions were observed in infected mice. Many trypanosomes were detected in the epididymal interstitium, and few were detected within the lumen of epididymal ducts. A large number of M1 and M2 macrophages infiltrated into the interstitium, and positive reactions for TNF-α, which is cytokine from M1 macrophages, was detected multifocally by immunofluorescence in those foci. Also, the apoptotic epithelial cells were increased in number. The aggregation of apoptotic epithelial cells was frequently associated with the loss of stainability for ZO-1, a major protein that forms tight junctions between epididymal epithelial cells. Also, the formation of sperm granuloma was observed in some infected mice. Trypanosomes in the epididymal interstitium is needed to invade the lumen for sexual transmission. The present results suggest that trypanosomes in the interstitium induce the infiltration of macrophages that secrete TNF-α, and may impair the tight
junctions of epididymal ducts by using the function of TNF-α, which induce apoptosis.
In chapter IV, to reproduce the sexual transmission of T. equiperdum between equids, I
attempted sexual transmission of trypanosomes from male mice to female mice. Unfortunately, sexual transmission of the parasite between mice was not established. Thus, at this time, intraperitoneal administration is the most effective method to infect mice with T. equiperdum.
In conclusion, the present study revealed the part of the pathogenesis of peripheral neuritis observed in dourine affected horses by immunohistochemical investigations of spontaneous cases. Also, we established a mouse infection model that can reproduce some of the clinical signs and histological lesions observed in dourine affected horses. Additionally, histopathological examinations of epididymitis in infected male mice revealed new insights of the parasitic and transmission strategies of T. equiperdum.博士学位論文
大学院畜産学研究科 獣医学専攻
Doctoral Program of Veterinary Sciencedoctoral thesi