Genetic characterization of H9N2avian influenza virus previously unrecognized in Korea

In this study, we describe the isolation and characterization of previously unreported Y280-lineage H9N2 viruses from two live bird markets in Korea in June 2020. Genetic analysis revealed that they were distinct from previous H9N2 viruses circulating in Korea and had highest homology to A/chicken/Shandong/1844/2019(H9N2) viruses. Their genetic constellation showed they belonged to genotype S, which is the predominant genotype in China since 2010, where genotype S viruses have infected humans and acted as internal gene donors to H5 and H7 zoonotic influenza viruses. Active surveillance and control measures need to be enhanced to protect the poultry industry and public health.

Genetic characterization of H9N2avian influenza virus previously unrecognized in Korea

In this study, we describe the isolation and characterization of previously unreported Y280-lineage H9N2 viruses from two live bird markets in Korea in June 2020. Genetic analysis revealed that they were distinct from previous H9N2 viruses circulating in Korea and had highest homology to A/chicken/Shandong/1844/2019(H9N2) viruses. Their genetic constellation showed they belonged to genotype S, which is the predominant genotype in China since 2010, where genotype S viruses have infected humans and acted as internal gene donors to H5 and H7 zoonotic influenza viruses. Active surveillance and control measures need to be enhanced to protect the poultry industry and public health.

Novel reassortants of clade 2.3.4.4 H5N6 highly pathogenic avian influenza viruses possessing genetic heterogeneity in South Korea in late 2017

Novel H5N6 highly pathogenic avian influenza viruses (HPAIVs) were isolated from duck farms and migratory bird habitats in South Korea in November to December 2017. Genetic analysis demonstrated that at least two genotypes of H5N6 were generated through reassortment between clade 2.3.4.4 H5N8 HPAIVs and Eurasian low pathogenic avian influenza virus in migratory birds in late 2017, suggesting frequent reassortment of clade 2.3.4.4 H5 HPAIVs and highlighting the need for systematic surveillance in Eurasian breeding grounds.

Control of type O foot-and-mouth disease by vaccination in Korea, 2014–2015

On December 3, 2014, a type O foot-and-mouth disease (FMD) outbreak began in Korea. Although vaccinations were administered, FMD cases increased steadily for five months, and reached 185 cases by April 2015. Most of the affected animals were pigs, which are vulnerable to vaccination. The FMD virus belonged to the South-East Asia (SEA) topotype that had been observed three times in Korea between April 2010 and July 2014. However, the FMD virus isolated in December 2014 had a unique feature; that is, partial deletion of the 5′ non-coding region, a deletion not seen in previous SEA topotype isolates identified in Korea. We conclude that this outbreak included the introduction of a new FMD strain to Korea, and that Korea was now affected by genetically similar FMD virus strains that are related to those from neighboring countries.

Review of regulatory management on standards and specifications for veterinary medical devices in Korea

Well-established standards and specifications for medical devices not only provide clarity and consistency in licensing processes but also secure device safety and effectiveness. This study reviewed regulatory standards and specifications for veterinary medical devices in Korea based on data obtained through analyses of those medical devices. General standards for electromechanical, electromagnetic, and biological safety and individual standards for 76 electric and 70 general medical device products have been established by the Korean Ministry of Food and Drug Safety. However, the first standards and specifications for veterinary medical devices were established in March 2000 for two products (disposable needle and syringe). Similar to the large number of standards for medical devices, there have been general standards for safety and individual standards for 72 veterinary medical devices (27 electric medical devices, 12 non-electric medical devices, 10 medical supplies, and 23 other types) established since 2014. These new standards considered, among other aspects, the devices' applications, usage characteristics, and industrial environment. To date, the establishment of standards and specifications for veterinary medical devices remains limited. This study suggests that improvements should be made to the regulation of general and individual standards associated with various veterinary medical instruments, supplies, and in vitro diagnostic medical reagents.

Novel foot-and-mouth disease virus in Korea, July-August 2014

Despite nation-wide immunization with O, A, and Asia 1 type vaccines in Republic of Korea, foot-and-mouth disease type O occurred again in July 2014 after three years and three months. This virus was a Mya-98 strain of the Southeast Asian topotype and was most similar to the identified type that circulated in East Asia in 2014. This was new virus with the deletion of 23 amino acids in 3A/3B1 region and low pathogenic property.

Congenital systemic melanosis in a black mongrel pig / 대한수의학회지

Four 3-day-old piglets with retarded growth were submitted to the Animal and Plant Quarantine Agency for diagnosis. Necropsy showed that one piglet had black spots ranging from 2 mm to 1 cm in diameter in the cerebellum, lungs, regional lymph nodes, and cecum. Histological findings were consistent with the gross appearance in which melanin pigmentation was observed in the organs mentioned above. Based on Fontana-Masson staining, we diagnosed this animal with systemic melanosis. To the best of our knowledge, this is the first case of systemic melanosis in black breeds of swine in Korea.

Comparison of transport media for the isolation and detection of Brachyspira hyodysenteriae / 대한수의학회지

Brachyspira (B.) hyodysenteriae is a causative agent of swine dysentery that is responsible for death and economic losses in the pig industry. It is imperative that clinical samples be delivered fresh for accurate diagnosis. The viability and DNA detection of B. hyodysenteriae using lab-made (phosphate buffered saline and modified tryptic soy broth) or commercial transport media (C, D, and E) were compared by culturing and real-time PCR at 4degrees C or room temperature (RT), respectively. B. hyodysenteriae grown in D (Anaerobe Systems, USA) and E (Starplex Scientific, Canada) media was viable for 4 days at 4degrees C and RT. However, B. hyodysenteriae in A, B, and C (culture swab; BD Biosciences, USA) media were not recovered after 2 days at RT. Ct values for real-time PCR at 4degrees C and RT ranged from 27.2 +/- 2.1 (C) to 29.6 +/- 0.5 (B), and 28.0 +/- 0.9 (E) to 30.2 +/- 1.5 (B), respectively. Considering the field conditions, it is important that transport media is used for specimen isolation and PCR to obtain an accurate diagnosis of swine dysentery.

Genetic analysis of env and gag gene fragments of bovine leukemia virus identified in cattle from Korea / 대한수의학회지

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis. This study was conducted to clarify the molecular characteristics of BLVs obtained from a specific region in Korea. Proviral BLVs were detected in anti-BLV antibody-positive blood samples by PCR. Env and gag fragments were sequenced and compared to previously published reference sequences. Analysis of the env gene sequence revealed that the YI strain was highly similar to genotype 1, including United States and Japanese strains. The gag gene sequence had the highest degree of similarity with a Japanese strain.

Loop-mediated isothermal amplification assay for the detection of Salmonella spp. in pig feces / 대한수의학회지

Salmonella are causative agents of gastroenteritis and systemic disease in animals. The invA gene was selected as a target sequence of loop-mediated isothermal amplification (LAMP) assay for diagnosis of Salmonella infection. The detection limits for broth dilution, spiked feces and enrichment were 10(4), 10(5) and 10(2) CFUs/mL, respectively. The LAMP assay developed in the present study may be a reliable method for detection of Salmonella spp. in pig feces.

Epitheliogenesis imperfecta in a bovine fetus of Korean native cattle / 대한수의학회지

In this study, we describe a case of epitheliogenesis imperfecta (EI) observed in the fetus of Korean native cattle. The fetus had multifocal areas of skin defect, especially on the distal portions of the four limbs, and the affected areas were bright-red and glistening. Histopathologically, these areas were characterized by complete absence of squamous epithelium, infiltration of inflammatory cells into the dermis, atrophy of hair follicles, sebaceous and sweat glands. To the best of our knowledge, this is the first report of epitheliogenesis imperfecta in Korean native cattle.

Fatal cryptosporidiosis in a calf / 대한수의학회지

A calf suffering from diarrhea was admitted to the Animal and Plant Quarantine Agency for diagnostic evaluation. Postmortem examination revealed that the mesenteric lymph node was enlarged and small intestine wall was thin. Microscopically, a large number of small round organisms were attached to the small intestine villi. Villous atrophy and proprial neutrophil infiltration were also observed. Based on modified Ziehl-Neelsen staining, electron microscopy, and ELISA results, the calf was diagnosed with fatal cryptosporidiosis.

Animal poisoning in Korea in 1974-June 2013 / 대한수의학회지

Animal poisoning has been occurred in Korea. However, the lack of the data about animal poisoning in Korea makes clinicians and diagnostician difficult to obtain information on poisoning cases. In this paper, we tried to gather information about animal poisoning from 1974 to June 2013 in Korea. Animal and Plant Quarantine Agency (QIA) record database were used to examine recent trends in animal poisoning. The analysis showed that the cattle was reported to be the most common species involved in animal poisoning and botulinum toxin constituted the primary group of toxicants. Animal poisoning occurred frequently on January and in Gyenggi-do. Although the data present in this manuscript is a little, it will be helpful to understand the general trend of animal poisoning in Korea.

Devastating endosulfan poisoning in Korean native cattle / 대한수의학회지

Here, we report the poisoning case of 10 cows. Several distinct clinical signs such as convulsion, excessive salivation, circling, lateral recumbency, and death were observed. Necropsy and histopathological examination did not reveal any significant abnormal findings. Moreover, no bacteria or viruses were detected in tissue, blood, and feeding food. However, endosulfan was detected from the stomach contents and microbials. Our results strongly suggest that death of cows may be closely associated with endosulfan poisoning.

Case report of Johne's disease in Korean black goat (Capra hircus aegagrus) / 대한수의학회지

Two Korean black goat (approx. 2 and 3 years old) showing diarrhea and chronic weight loss were submitted to Animal and Plant Quarantine Agency. At necropsy, there were thickening of small intestine and enlargement of mesenteric lymph nodes. Microscopically, they had granulomatous enteritis in the small and large intestine and granulomatous lymphadenitis. By polymerase chain reaction (PCR) and acid fast stain, strong positive reaction and acid-fast rod bacteria were detected. According to the result of histopathology and PCR, we confirmed this case as Johne's disease. As far as we know, this is the first report of Johne's disease in Korean black goat.

The Effects of Air-borne Particulate Matters on the Alveolar Macrophages for the TNF-alpha and IL-1beta Secretion / 결핵및호흡기질환

BACKGROUND: PM is known to induce various pulmonary diseases, including asthma, cancer, fibrosis and chronic bronchitis. Despite the epidemiological evidence the pathogenesis of PM-related pulmonary diseases is unclear. METHODS: This study examined the effects of PM exposure on the secretion of TNF-alpha and IL-1beta in the cultured alveolar macrophages. The cultured primary alveolar macrophages were treated with the medium, PM (5~20 microgram/cm2), LPS (5ng/ml), and PM with LPS for 24h and 48h respectively. ELISA was used to assay the secreted TNF-alpha and IL-beta in the culture medium. Western blotting was used to identify and determine the level of proteins isolated from the culture cells. The cells cultured in the Lab-Tek(R) chamber slides were stained with immunocytochemical stains. RESULTS: PM induced TNF-alpha and IL-1beta secretion in the culturing alveolar macrophages, collected from the SPF and inflammatory rats. However, the effects were only dose-dependent in the inflammatory macrophages. When the cells were co-treated with PM and LPS, there was a significant synergistic effect compared with the LPS in the both cell types. CONCLUSION: PM might be play an important role in the induction and/or potentiation of various lung diseases by oversecretion of TNF-alpha and IL-1beta.

The Effects of air-borne particulate matters on the Alveolar Macrophages for the iNOS Expression and Nitric Oxide with Nitrotyrosilated-proteins Formation / 결핵및호흡기질환

BACKGROUND: Particulate matters (PM) when inhaled is known to induce pulmonary diseases including asthma and chronic bronchitis when inhaled. Despite the epidemiological proofevidence, the pathogenesis of PM-related pulmonary diseases is unclearremain poorly understood. METHODS: Primary alveolar macrophages were harvested from the SPF and inflammatory rats by bronchioalveolar lavage (BAL). The cultured primary alveolar macrophages were treated with the medium only, PM only (5~40 microgram/cm2), LPS (5ng/ml) only, and PM with LPS for 24 and 48 hours. The level of secreted nitric oxide (NO) was assayed from the cultured medium by using the Griess reaction. The cultured cells were utilized for the western blotting against the inducible nitric oxide synthase (iNOS) proteins. Immunocyto- chemical staining against the iNOS and NT-proteins were performed in cells that cultured in the Lab-Tek(R) chamber slide after treatments. RESULTS: The PM that utilizein this experiments induced NO formation with iNOS expression in the cultured SPF and inflammatory rats alveolar macrophages, by itself. When the cells were co-treated with PM and LPS, there was a statistically significant synergistic effect on NO formation and iNOS expression over the LPS effect. The cells from the sham control showed minimal immunoreactivity for the NT-proteins. Significantly higher quantities of NT-proteins were detected in the PM and PM with LPS co-treated cells than from the sham control. CONCLUSION: Increased iNOS expression and NO formation with increased NT-proteins formation might be involved in the pathogenesis of PM-induced lung injury.