• Applied Microscopy
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• 제52권
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• pp.11.1-11.9
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• 2022

Zoonotic poxvirus infections pose significant threat to human health as we have witnessed recent spread of monkeypox. Therefore, insights into molecular mechanism behind poxvirus replication cycle are needed for the development of efficient antiviral strategies. Virion assembly is one of the key steps that determine the fate of replicating poxviruses. However, in-depth understanding of poxvirus assembly is challenging due to the complex nature of multi-step morphogenesis and heterogeneous virion structures. Despite these challenges, decades of research have revealed virion morphologies at various maturation stages, critical protein components and interactions with host cell compartments. Transmission electron microscopy has been employed as an indispensable tool for the examination of virion morphology, and more recently for the structure determination of protein complexes. In this review, we describe some of the major findings in poxvirus morphogenesis and the contributions of continuously advancing electron microscopy techniques.

• Journal of Preventive Veterinary Medicine
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• 제41권3호
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• pp.121-123
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• 2017

The hepatitis E virus (HEV) is a leading causative agent of acute hepatitis in humans. Zoonotic HEV strains have been isolated from several animal species, including pigs. New HEV variants have been recently isolated from camels in the Middle East. In the present study, fecal samples from fallow deer, formosan deer, alpaca, and guanaco were analyzed for the detection of HEV. One HEV strain was detected from guanaco, a species of camelids. The nucleotide sequence of guanaco HEV was identical to those of deer HEV-3 strains, which implied the cross-species transmission of HEV-3 from deer to guanaco.

• 농촌의학ㆍ지역보건
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• 제15권1호
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• pp.49-55
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• 1990

Zoonoses are those diseases and infections that are naturally transmitted between vertebrate animals and man. At present, approximately 175 diseases caused by virus, rickettsia, bacteria, protozoa and helminthes as well as some of arthropods and the number is continually increasing. Although zoonoses are generally recognized as significant health problems, the actual prevalence and incidence of zoonotic infections is difficult to determine. Medical services in a rural area are scarce and ill persons may have little chance to see a physician. Furthermore, a lack of physician awareness and of appropriate diagnostic support is made often misdiagnosis. In rural Korea, parasitic disease is still important subject in the field of zoonotic infections considering its number and morbidity. Recently there was conspicuous reduction of soil-transmitted parasitic diseases (i.e. ascariasis. hookworms, trichuriasis), but clonorchiasis. intestinal trematodiases and taeniasis are a considerable problem. This is often significantly related to human behavioral patterns based on socio-economic and cultural conditions and linked with the local biologic and physical environment. The most of all parasitic zoonoses to man and animals are the food-transmitted parasitic diseases, and domestic animals such as dog, cat, pig, as well as fat and some mammals, ruminants and birds are act as reservoir hosts. In the present topics, current problems of parasitic zoonoses caused by protozoan infections (i. e. toxoplasmosis, pneumocystosis and cryptosporidiosis) which are the most common opportunistic in AIDS or immunocompromised persons, trematode infections (i.e. clonorchiasis, paragonimiasis and some intestinal tremadodiases). cestode infections such as cysticercosis and sparganosis, and some nematode infections of anisakiasis, thelaziasis and strongyloidiasis, are discussed here those on the occurrence in man and animals and the source of transmission as well as prevention and control measures in Korea.

• Parasites, Hosts and Diseases
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• 제55권3호
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• pp.351-355
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• 2017

Hymenolepis nana and Hymenolepis diminuta are globally widespread zoonotic cestodes. Rodents are the main reservoir host of these cestodes. Brown rats (Rattus norvegicus) are the best known and most common rats, and usually live wherever humans live, especially in less than desirable hygiene conditions. Due to the little information of the 2 hymenolepidid species in brown rats in China, the aim of this study was to understand the prevalence and genetic characterization of H. nana and H. diminuta in brown rats in Heilongjiang Province, China. Total 114 fecal samples were collected from brown rats in Heilongjiang Province. All the samples were subjected to morphological examinations by microscopy and genetic analysis by PCR amplification of the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene and the internal transcribed spacer 2 (ITS2) region of the nuclear ribosomal RNA gene. In total, 6.1% (7/114) and 14.9% (17/114) of samples were positive for H. nana and H. diminuta, respectively. Among them, 7 and 3 H. nana isolates were successfully amplified and sequenced at the COX1 and ITS2 loci, respectively. No nucleotide variations were found among H. nana isolates at either of the 2 loci. Seventeen H. diminuta isolates produced 2 different COX1 sequences while 7 ITS2 sequences obtained were identical to each other. The present results of H. nana and H. diminuta infections in brown rats implied the risk of zoonotic transmission of hymenolepiasis in China. These molecular data will be helpful to deeply study intra-specific variations within Hymenolepis cestodes in the future.

• Parasites, Hosts and Diseases
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• 제46권3호
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• pp.199-201
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• 2008

Toxoplasma gondii is an obligate intracellular zoonotic protozoan with a worldwide distribution. It infects humans as well as a broad spectrum of vertebrate hosts. Cats and wild felidae play crucial roles in the epidemiology of toxoplasmosis. This study was performed to survey the prevalence of T. gondii infection among stray cats in the Gyeonggi-do, Republic of Korea. A total of 174 stray cat blood samples were collected from Gwacheon-si (n = 20), Bucheon-si (82), and Yangju-si (72). Positive sera for T. gondii were identified in 14 samples (8.1%) exclusively via the latex agglutination test, 28 (16.1%) via ELISA, and 23 (13.2%) via PCR analysis. The overall infection rate of female stray cats (29.2%) presented as higher than that of male cats (24.0%). This study suggests that T. gondii is widespread in the stray cat population of Gyeonggi-do, Korea. It is urgently needed to control urban stray cat population and to reduce the risk of zoonotic transmission of toxoplasmosis to other animal hosts and humans.

• Journal of Veterinary Science
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• 제21권4호
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• pp.56.1-56.13
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• 2020

Background: The live bird market (LBM) plays an important role in the dynamic evolution of the avian influenza H5N1 virus. Objectives: The main objective of this study was to monitor the genetic diversity of the H5N1 viruses in LBMs in Indonesia. Methods: Therefore, the disease surveillance was conducted in the area of Banten, West Java, Central Java, East Java, and Jakarta Province, Indonesia from 2014 to 2019. Subsequently, the genetic characterization of the H5N1 viruses was performed by sequencing all 8 segments of the viral genome. Results: As a result, the H5N1 viruses were detected in most of LBMs in both bird' cloacal and environmental samples, in which about 35% of all samples were positive for influenza A and, subsequently, about 52% of these samples were positive for H5 subtyping. Based on the genetic analyses of 14 viruses isolated from LBMs, genetic diversities of the H5N1 viruses were identified including clades 2.1.3 and 2.3.2 as typical predominant groups as well as reassortant viruses between these 2 clades. Conclusions: As a consequence, zoonotic transmission to humans in the market could be occurred from the exposure of infected birds and/or contaminated environments. Moreover, new virus variants could emerge from the LBM environment. Therefore, improving pandemic preparedness raised great concerns related to the zoonotic aspect of new influenza variants because of its high adaptivity and efficiency for human infection.

• Parasites, Hosts and Diseases
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• 제61권3호
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• pp.325-331
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• 2023

Thelazia callipaeda, a parasitic nematode that causes thelaziosis in various mammals, including humans, is known to be endemic in Korea. However, life cycle-related information on the parasite, primarily from human infection and a few dog cases, is limited. This study reports additional cases of T. callipaeda infections in dogs from both rural and urban areas in Korea, indicating the potential for transmission to humans and other animals. We collected 61 worms from 8 infected dogs from Paju and Cheongju Cities and observed their morphological characteristics under a light microscope. The findings indicate that T. callipaeda infections in animals in Korea may be underestimated and are distributed close to human environments. Our results contribute to the growing knowledge of the reservoir hosts of T. callipaeda in Korea and highlight the importance of continued surveillance and research to prevent and control this emerging zoonotic disease.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.425-432
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• 2010

Staphylococcus intermedius is a common cause of otitis externa, pyoderma, and wound infections in companion animals. Although S. intermedius infections are rare in humans, it is zoonotic, with several case reports describing fatal human infections. Presently, we sought to isolate S. intermedius strains from various sources at animal hospitals nationwide in Korea, examine their antibiotic susceptibilities, and determine the possibility of horizontal transmission between animals and humans. Pulsed-field gel electrophoresis (pFGE) was used to compare the mecA gene in S. intermedius strains from humans, animals, and the environment in animal hospitals. A total of 119 S. intermedius strains were isolated from 529 samples. Using the disk diffusion method, over 90% of the isolates were found to be susceptible to cephalothin, amoxicillin-clavulanic acid, vancomycin, imipenem, nitroflurantoin, and amikacin, whereas 97.5% and 98.3% of the isolates were resistant to penicillin and ampicillin, respectively. Among the 39 S. intermedius strains harboring mecA, similar PFGE patterns were observed between seven isolates from an animal, two isolates from veterinary staff, and the environment in one animal hospital, and single isolates from an animal and a veterinarian at another hospital. This result suggests the possibility of horizontal transmission of S. intermedius containing mecA between humans, animals, and the environment in animal hospitals and also emphasizes on the importance of S. intermedius with mecA as a possible emerging threat to public health.

• Parasites, Hosts and Diseases
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• 제56권1호
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• pp.53-59
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• 2018

Tick saliva is critically important for continuous attachment to the host, blood feeding for days, and transmission of tick-borne pathogens. To characterize the patterns of inflammatory cytokine gene expression during its attachment and blood sucking time, peripheral blood samples of rabbits infested with Haemaphysalis longicornis ticks were collected at different intervals. Blood histamine concentration was evaluated as well as gene encoding IFN-${\gamma}$, TNF-${\alpha}$, IL-2, IL-6, IL-4, and IL-10 were compared with non-infested rabbits. Blood histamine concentration of tick-infested rabbits during fast feeding time was significantly higher than that of non-infested rabbits. In both nymph and adult tick infested rabbits, expression of TNF-${\alpha}$ and IFN-${\gamma}$ genes were decreased significantly (P<0.05), while expression of IL-4, IL-6, and IL-10 were increased 1.3 to 7 folds in adult infested rabbits with the exception of IL-6 that was significantly (P<0.05) decreased in nymph infested rabbits. IL-2 was not expressed in either nymph or adult infestation. H. longicornis saliva is capable of modulate host responses through a complex correlation with histamine and Th1, Th2 mediated cytokines that suppress the inflammatory responses directed toward inflammatory mediators introduced into the host during tick feeding.

• 한국임상수의학회지
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• 제7권2호
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• pp.521-525
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• 1990

Microspoum canis에 감염된 개 및 고양이와 직접 접촉한 경험이 있는 5명의 환자를 조사하여 동물기생체로서의 이 진균의 중요성을 확인하였다. ring worm의 전형적인 병변은 신체의 노출된 부위에만 발생하였다. M. canis는 환자와 감염된 애완동물의 피부병변에서 분리되었으며 피부 시료로부터 직접 증명되었다. 그림에도 불구하고 비접촉군과 사물성환경으로 부터는 증명되지 않았다. 사람, 개 및 고양이에서 분리된 진균들은 육안적으로나 현미경적으로 서로 비슷한 형태를 나타내었다. 이 진균들의 유전학적 연구결과는 교배(-)형이었다. 동물기호성 표재성진균의 전염은 직접적인 접촉에 의해 자주 일어나는 것으로 사료된다. 이감염증에 대한 역학과 예방방법에 대해 고찰하였다.