2019 Changes to the Journal of Veterinary Science

No abstract available.

2018 Changes in the Journal

No abstract available.

Pathogenesis of coxsackievirus B2 in mice: characterization of clinical isolates of the coxsackievirus B2 from patients with myocarditis and aseptic meningitis in Korea

Group B coxsackieviruses (CVBs) are a group of common human pathogens producing various clinical symptoms. Although the virology of CVB is well known, there is limited information on viral pathogenesis and the relationship between clinical symptoms and viral phenotype, particularly for CVB type 2 (CVB2). In 2004 in Korea, two CVB2 strains were isolated: CB2/04/279 from stool of an acute myocarditis patient with heart failure and CB2/04/243 from an aseptic meningitis patient. In this study, a high degree of homology was observed between the CB2/04/279 and CB2/04/243 full genome sequences. The two Korean CVB2 isolates had 93.1% homology compared to 82.1%–82.5% nucleotide sequence identity with the cardiovirulence-associated reference CVB strain Ohio-1 (CVB/O). CVB2-induced pathogenesis was analyzed, focusing on virus-induced pathology of various tissues in 4-week-old BALB/c inbred male mice. Myocarditis developed and extensive pancreatic inflammation was observed in all mice infected with CB2/04/279 or CVB/O, but not in animals infected with CB2/04/243. This is the first report of the full-genomic sequence and pathogenesis of the CVB2 strain isolated from an acute myocarditis patient in Korea.

First detection of West Nile virus in domestic pigeon in Korea

West Nile virus (WNV) is a mosquito-borne zoonotic pathogen that has spread throughout Europe and the United States. Recently, WNV spread to East and Southeast Asia, and great efforts have been made in South Korea to prevent the spread of WNV from neighboring countries. In this study, we diagnosed the first case of WNV in pigeons (Columba livia domestica) residing in cities using a competitive enzyme-linked immunosorbent assay and confirmed it with nested reverse transcription polymerase chain reaction analysis and sequencing. This is the first report to provide convincing evidence that WNV is present within South Korea.

Detection and Molecular Characterization of Cryptosporidium spp. from Wild Rodents and Insectivores in South Korea

In order to examine the prevalence of Cryptosporidium infection in wild rodents and insectivores of South Korea and to assess their potential role as a source of human cryptosporidiosis, a total of 199 wild rodents and insectivore specimens were collected from 10 regions of South Korea and screened for Cryptosporidium infection over a period of 2 years (2012-2013). A nested-PCR amplification of Cryptosporidium oocyst wall protein (COWP) gene fragment revealed an overall prevalence of 34.2% (68/199). The sequence analysis of 18S rRNA gene locus of Cryptosporidium was performed from the fecal and cecum samples that tested positive by COWP amplification PCR. As a result, we identified 4 species/genotypes; chipmunk genotype I, cervine genotype I, C. muris, and a new genotype which is closely related to the bear genotype. The new genotype isolated from 12 Apodemus agrarius and 2 Apodemus chejuensis was not previously identified as known species or genotype, and therefore, it is supposed to be a novel genotype. In addition, the host spectrum of Cryptosporidium was extended to A. agrarius and Crosidura lasiura, which had not been reported before. In this study, we found that the Korean wild rodents and insectivores were infected with various Cryptosporidium spp. with large intra-genotypic variationa, indicating that they may function as potential reservoirs transmitting zoonotic Cryptosporidium to livestock and humans.

Decreased expression of Toll-like receptor 4 and 5 during progression of prostate transformation in transgenic adenocarcinoma of mouse prostate mice

Chronic inflammation has been considered an important risk factor for development of prostate cancer. Toll-like receptors (TLRs) recognize microbial moieties or endogenous molecules and play an important role in the triggering and promotion of inflammation. In this study, we examined whether expression of TLR4 and TLR5 was associated with progression of prostate transformation in the transgenic adenocarcinoma of mouse prostate (TRAMP) model. The expression of TLR4 and TLR5 was evaluated by immunohistochemisty in formalin-fixed paraffin-embedded prostate tissue from wild-type (WT) and TRAMP mice. Normal prostate tissue from WT mice showed strong expression of TLR4 and TLR5. However, TLR4 expression in the prostate tissue from TRAMP mice gradually decreased as pathologic grade became more aggressive. TLR5 expression in the prostate tissue from TRAMP mice also decreased in low-grade prostate intraepithelial neoplasia (PIN), high-grade PIN and poorly differentiated adenocarcinoma. Overall, our results suggest that decreased expression of TLR4 and TLR5 may contribute to prostate tumorigenesis.

Detection of Corynebacterium bovis infection in athymic nude mice from a research animal facility in Korea

Corynebacterium (C.) bovis infection in nude mice causes hyperkeratosis and weight loss and has been reported worldwide but not in Korea. In 2011, nude mice from an animal facility in Korea were found to have white flakes on their dorsal skin. Histopathological testing revealed that the mice had hyperkeratosis and Gram-positive bacteria were found in the skin. We identified isolated bacteria from the skin lesions as C. bovis using PCR and 16S rRNA sequencing. To the best of our knowledge, this is the first report of C. bovis infection in nude mice from Korea.

Antiviral Activity of Hederasaponin B from Hedera helix against Enterovirus 71 Subgenotypes C3 and C4a

Enterovirus 71 (EV71) is the predominant cause of hand, foot and mouth disease (HFMD). The antiviral activity of hederasaponin B from Hedera helix against EV71 subgenotypes C3 and C4a was evaluated in vero cells. In the current study, the antiviral activity of hederasaponin B against EV71 C3 and C4a was determined by cytopathic effect (CPE) reduction method and western blot assay. Our results demonstrated that hederasaponin B and 30% ethanol extract of Hedera helix containing hederasaponin B showed significant antiviral activity against EV71 subgenotypes C3 and C4a by reducing the formation of a visible CPE. Hederasaponin B also inhibited the viral VP2 protein expression, suggesting the inhibition of viral capsid protein synthesis.These results suggest that hederasaponin B and Hedera helix extract containing hederasaponin B can be novel drug candidates with broad-spectrum antiviral activity against various subgenotypes of EV71.

Antiviral Activity of Hederasaponin B from Hedera helix against Enterovirus 71 Subgenotypes C3 and C4a

Enterovirus 71 (EV71) is the predominant cause of hand, foot and mouth disease (HFMD). The antiviral activity of hederasaponin B from Hedera helix against EV71 subgenotypes C3 and C4a was evaluated in vero cells. In the current study, the antiviral activity of hederasaponin B against EV71 C3 and C4a was determined by cytopathic effect (CPE) reduction method and western blot assay. Our results demonstrated that hederasaponin B and 30% ethanol extract of Hedera helix containing hederasaponin B showed significant antiviral activity against EV71 subgenotypes C3 and C4a by reducing the formation of a visible CPE. Hederasaponin B also inhibited the viral VP2 protein expression, suggesting the inhibition of viral capsid protein synthesis.These results suggest that hederasaponin B and Hedera helix extract containing hederasaponin B can be novel drug candidates with broad-spectrum antiviral activity against various subgenotypes of EV71.

The First Case of Capillaria hepatica Infection in a Nutria (Myocastor coypus) in Korea

This study reports the first case of Capillaria hepatica infection in a nutria in Korea. Ten nutrias, captured near the Nakdong River, were submitted to our laboratory for necropsy. White-yellowish nodules were found in the liver of 1 of the nutrias at necropsy. Histologically, the lesions were granulomatous, and infiltrations of lipid-laden macrophages, eosinophils, and several multinucleated giant cells were observed. The lesions consisted of numerous eggs and necrotic hepatocytes. The eggs were lemon-shaped and had polar plugs at the ends of both long sides. The eggs were morphologically identified as those of C. hepatica. Worldwide, C. hepatica infection in nutrias is very rare. Nutrias are a kind of livestock, as well as wildlife; therefore, an epidemiological study for parasitic infections needs to be conducted.

Receptor Interacting Protein 2 (RIP2) Is Dispensable for OVA-Induced Airway Inflammation in Mice

PURPOSE: Asthma is a pulmonary chronic inflammatory disease characterized by airway obstruction and hyperresponsiveness. Pattern recognition receptors are known to play a key role in the development of allergic diseases as well as host defenses against microbial infection. Receptor interacting protein 2 (RIP2), a serine/threonine kinase, is an adaptor molecule of NOD1 and NOD2, and genetic variation in this receptor is known to be associated with the severity of allergic asthma in children. In this study, we examined the role of RIP2 in the development of allergic airway inflammation in a mouse model. METHODS: Airway inflammation was induced in mice through intranasal administration of ovalbumin (OVA) after 2 intraperitoneal immunizations with OVA. Lung inflammation and mucus hypersecretion were examined histologically and total cell infiltration in bronchoalveolar (BAL) fluids was determined. Levels of the Th2-related cytokines, IL-5 and IL-13, in lung extracts were measured by ELISA. Serum antigen-specific IgE and IgG1 levels were also assessed. RESULTS: OVA-induced lung inflammation and mucus hypersecretion were not different between WT and RIP2-deficient mice. The IL-5 and IL-13 levels in the bronchoalveolar (BAL) fluids were also not impaired in RIP2-deficient mice compared to WT mice. Moreover, RIP2 deficiency did not affect serum OVA-specific IgG1 and IgE levels. CONCLUSIONS: Our results suggest that RIP2 is not associated with the development of allergic airway inflammation.

TRIF Deficiency does not Affect Severity of Ovalbumin-induced Airway Inflammation in Mice

Allergic asthma is a chronic pulmonary inflammatory disease characterized by reversible airway obstruction, hyperresponsiveness and eosinophils infiltration. Toll-like receptors (TLRs) signaling are closely associated with asthma and have emerged as a novel therapeutic target in allergic disease. The functions of TLR3 and TLR4 in allergic airway inflammation have been studied; however, the precise role of TIR-domain-containing adapter-inducing interferon-beta (TRIF), the adaptor molecule for both TLR3 and TLR4, is not yet fully understood. To investigate this, we developed a mouse model of OVA-induced allergic airway inflammation and compared the severity of allergic airway inflammation in WT and TRIF-/- mice. Histopathological assessment revealed that the severity of inflammation in airway inflammation in TRIF-deficient mice was comparable to that in WT mice. The total number of cells recovered from bronchoalveolar lavage fluid did not differ between WT and TRIF-deficient mice. Moreover, TRIF deficiency did not affect Th1 and Th2 cytokine production in lung tissue nor the level of serum OVA-specific IgE, IgG1 and IgG2c. These findings suggest that TRIF-mediated signaling may not be critical for the development of allergic airway inflammation.

Effects of dietary high fat on prostate intraepithelial neoplasia in TRAMP mice / 한국실험동물학회지

Increased fat intake is known to be a major cause of prostate cancer. In this study, we investigated the effect of dietary high fat on prostate intraepithelial neoplasia using transgenic adenocarcinoma mouse prostate (TRAMP) mice. Six-week-old male TRAMP mice were fed AIN93G (control group, 4.0 kcal/kg, n=6) and AIN93G-HFD (experimental group, 4.8 kcal/kg, n=7) for 10 weeks. Prostate histopathology, urogenital tract (UGT) weight, epididymal white adipose tissue weight, argyrophilic nucleolar organizer regions (AgNORs) counts, and serum leptin levels were examined. AIN93G-HFD fed group showed progressed neoplastic lesions in the prostate (P<0.05) compared to AIN93G fed group. AIN93G-HFD intake resulted in a increase in the weight of UGT (P<0.05) and epididymal white adipose tissue. The number of Ag-NOR positive dots significantly increased in each prostate lobe and final serum leptin levels in AIN93G-HFD fed group were about twice those of AIN93G fed group (P<0.05). Dietary high fat was related to the prostate cancer progression in the early stage of TRAMP mice and increased serum leptin levels, suggesting that the regulation of dietary components could delay the progression of prostate cancer.

Adiaspiromycosis of an Apodemus agrarius captured wild rodent in Korea / 한국실험동물학회지

Adiaspiromycosis is caused by pulmonary infection with Emmonsia. Inhalated spores of Emmonsia cause asymptomatic infection to necrogranulomatous pneumonia, depending on the burden of adiaspore and host immunity. For disease monitoring of wild rodents captured on Jeju Island in Korea, we examined the lung tissue of wild rodents histopathologically. Spores composed of thick three-layered walls were found following histopathological examination and were diagnosed as adiaspiromycosis. Adiaspiromycosis has been found in mammals in many parts of the world. To our knowledge, this is the first report of adiaspiromycosis of an Apodemus agrarius captured in Korea.

Detection of sarcocystic infection in a wild rodent (Apodemus agrarius chejuensis) captured on Jeju island / 한국실험동물학회지

Sarcocystis spp is a causative agent of sarcocystosis. They have a characteristic life cycle infecting both prey and predator. Sarcocystis can cause myositis, atrophy of the adjacent cells and abortion in cattle. In mice, sarcocystosis causes mild cellular reactions without clinical disease. Severe haemorrhage and abortion were also reported. For monitoring the disease in wild rodents of the Korean peninsula, we captured Apodemus agrarius chejuensis on Jeju island and examined the specimen histopathologically. Intramuscular cysts were found and diagnosed as Sarcocystis. Sarcocystic infection has been reported in worldwide. There have been many reported infections in cattle and pigs in Korea. To our knowledge, this is the first report of Sarcocystis in Apodemus agrarius chejuensis captured in Korea.

Production of specific antibodies against SARS-coronavirus nucleocapsid protein without cross reactivity with human coronaviruses 229E and OC43

Severe acute respiratory syndrome (SARS) is a life-threatening disease for which accurate diagnosis is essential. Although many tools have been developed for the diagnosis of SARS, false-positive reactions in negative sera may occur because of cross-reactivity with other coronaviruses. We have raised polyclonal and monoclonal antibodies (Abs) using a recombinant form of the SARS virus nucleocapsid protein. Cross-reactivity of these anti-SARS Abs against human coronavirus (HCoV) 229E and HCoV OC43 were determined by Western blotting. The Abs produced reacted with recombinant SARS virus nucleocapsid protein, but not with HCoV 229E or HCoV OC43.

NaCl plus chitosan as a dietary salt to prevent the development of hypertension in spontaneously hypertensive rats

The effect of NaCl plus 3% chitosan on the systolic blood pressure of spontaneously hypertensive rats (SHR) were evaluated and compared with NaCl plus KCl (NaCl, 49.36% + KCl 49.36%) and chitosan or NaCl treatment alone. In SHR, administration of NaCl plus chitosan (44 mM Na/day) for two months significantly decreased the systolic blood pressure greater than of NaCl plus KCl and NaCl alone. NaCl plus chitosan resulted, though not statistically significant, in decreased urinary Na+ excretion and decreased blood urea nitrogen levels. Urinary creatinine of NaCl plus chitosan was slightly decreased compared to 3 treated groups. Serum electrolytes levels, however, remained unchanged. The combination of NaCl and chitosan may be superior to the conventional use of NaCl plus KCl or NaCl alone in the prevention of hypertension. Even though these supplementary diets have demonstrated potential anti-hypertensive effects in the experimental animal model, further research is needed before any recommendations can be made.

Protective and therapeutic effects of an extract mixture of alder tree, labiate herb, milk thistle green bean-rice bran fermentation, and turnip against ethanol-induced toxicity in the rat

An herbal extract mixture and yogurt added to the herbal extract mixture were tested for their protective and therapeutic effects on ethanol-induced liver injury. The herbal extract mixture, yogurt and commercial drugs were used for treatment for two weeks prior to administering a single oral dose of ethanol (3 g/kg body weight). The herbal extract mixture and yogurt added to the herbal extract mixture were found to provide protection against ethanolinduced toxicity comparable to the commercial drug treatment, according to the serum and histopathological analysis. It was also shown that co-treatment with herbal extract mixture and yogurt against a triple oral dose of ethanol (2 g/kg body weight, over one week) provided protection against ethanol toxicity. After the initial set of experiments, the herbal extract mixture and yogurt treatments were extended for three more weeks. When compared to the positive control, further treatment with both the herbal extract and yogurt significantly reduced liver injury and resulted in a lower grade of lipid deposition.

In vivo alternative testing with zebrafish in ecotoxicology

Although rodents have previously been used in ecotoxicological studies, they are expensive, time-consuming, and are limited by strict legal restrictions. The present study used a zebrafish (Danio rerio) model and generated data that was useful for extrapolating toxicant effects in this system to that of humans. Here we treated embryos of the naive-type as well as a transiently transfected zebrafish liver cell line carrying a plasmid (phAhREEGFP), for comparing toxicity levels with the well-known aryl hydrocarbon receptor (AhR)-binding toxicants: 3,3',4,4',5-pentachlorobiphenyl (PCB126), 2,3,7,8-tetrachlorodibenzo-p-dioxin, and 3-methylcholanthrene. These toxicants induced a concentration-dependent increase in morphological disruption, indicating toxicity at early life-stages. The transient transgenic zebrafish liver cell line was sensitive enough to these toxicants to express the CYP1A1 regulated enhanced green fluorescent protein. The findings of this study demonstrated that the zebrafish in vivo model might allow for extremely rapid and reproducible toxicological profiling of early life-stage embryo development. We have also shown that the transient transgenic zebrafish liver cell line can be used for research on AhR mechanism studies.

Idiopathic intranuclear inclusion bodies in the renal tubular epithelia of Japanese quail (Coturnix coturnix japonica)

We report idiopathic intranuclear inclusion bodies in the renal tubular epithelia of two cases of among the 960 Japanese quail (Coturnix coturnix japonica) in the course of the acute oral toxicity and dietary toxicity test. Basophilic inclusion bodies were seen only in the nuclei of renal tubular epithelia. We could not classify our case into any adenovirus infection by clinical signs and lesions. The inclusion bodies were only identified as adenovirus-like particles based upon the electronmicroscopical features.