Publications by authors named "Ji Hyoung Ryu"
Article Synopsis
- Between 2019 and 2021, 21 farms in South Korea were confirmed to be infected with African swine fever (ASF), with viruses examined from blood and spleen samples for genetic analysis.
- The phylogenetic study showed that all strains belonged to p72 genotype II and serogroup 8, with specific genetic features including the intergenic region II variant and a consistent central variable region.
- Notably, while most strains were identical to others found in Georgia and China, the 18th isolate displayed a unique mutation with three nucleotide insertions, indicating it might be a distinct variant compared to the other infections.
Article Synopsis
- African swine fever (ASF) was first identified in South Korea in 2019, with reports of 21 domestic pig cases and 1,875 infected wild boars by the end of 2021.
- Researchers experimented with four different ASF virus strains from domestic pigs between 2019 and 2021 to assess their virulence in pigs.
- All infected pigs succumbed to the disease within 4-9 days, displaying severe clinical symptoms and necropsy findings, confirming that the virulence of the ASFV strains in South Korea remained consistently high during that time.
Free space optical (FSO) communication can support various unmanned aerial vehicles' (UAVs) applications that require large capacity data transmission. In order to perform FSO communication between two terminals, it is essential to employ a pointing, acquisition, and tracking (PAT) system with an efficient and optimal performance. We report on the development of a common optical-path-based FSO communication system, tailored for applications in UAVs.
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- * The 2020 cases involved two farms, which tested positive for ASF, showing the same genetic markers as the 2019 isolates.
- * To prevent further outbreaks, stronger biosecurity measures and increased surveillance are recommended, especially in areas where wild boars and domestic pigs interact.
On 17 September 2019, the first outbreak of African swine fever in a pig farm was confirmed in South Korea. By 9 October, 14 outbreaks of ASF in domestic pigs had been diagnosed in 4 cities/counties. We isolated viruses from all infected farms and performed genetic characterization.
View Article and Find Full Text PDFBackground: Escherichia coli is an important cause of diarrhea in calves and its diarrheagenic properties are related to presence of certain virulence genes. In this study, the prevalence of virulence genes F5, F17, F41, sta, stx1, stx2, eae, and saa in E. coli isolated from pre-weaned calves presenting with (n= 329) or without diarrhea (n= 360) was explored using multiplex polymerase chain reaction.
View Article and Find Full Text PDFIdentification of Zoonotic Tick-Borne Pathogens from Korean Water Deer ().
Vector Borne Zoonotic Dis
October 2020
Article Synopsis
- Korean water deer in the Republic of Korea are significant hosts for ticks and tick-borne diseases, and a study investigated the prevalence of tick-borne pathogens in rescued deer.
- The research found various tick-borne pathogens, with a notable presence of a specific pathogen related to human granulocytic anaplasmosis, which marked the first report of this infection in Korean water deer.
- Genetic analysis revealed distinct variants of pathogens within the population, showing a high genetic similarity to those found in other hosts, suggesting the potential for zoonotic transmission.
Background: Enterocytozoon bieneusi is the most common microsporidian species infecting humans and various animals worldwide. To date, there has been limited information on the prevalence of infection and genotypes of E. bieneusi in cattle in the Republic of Korea.
View Article and Find Full Text PDFCalf diarrhea causes severe economic losses in the cattle industry worldwide. This study investigated the prevalence of bovine coronavirus (BCoV), bovine norovirus (BNoV), bovine group A rotavirus (BoRVA), and bovine torovirus (BToV) in calves aged ≤ 60 days, regardless of diarrhea, across nine different regions in the Republic of Korea (ROK) and reported associations between these viruses and diarrhea. Fecal samples were collected rectally from 689 calves: normal (n = 360) and diarrheic (n = 329).
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- Cryptosporidium spp. and Giardia duodenalis are parasites that can cause diarrhea in both humans and animals, and their molecular data in calves from the Republic of Korea (ROK) is not well-documented.
- A study collected fecal samples from 315 pre-weaned calves to determine the prevalence of these parasites, finding 4.4% for Cryptosporidium (specifically C. parvum) and 12.7% for Giardia duodenalis, with no co-infections observed.
- The results indicated that while C. parvum prevalence is age-independent, Giardia prevalence significantly increases in calves aged 41-50 days, suggesting a potential zoonotic risk for human infections.
Genetic analysis of bovine viral diarrhea virus in pre-weaned native Korean calves.
Trop Anim Health Prod
September 2019
Bovine viral diarrhea virus (BVDV), a prominent viral pathogen worldwide, causes substantial economic losses in the cattle industry. BVDV comprises two recognized species, BVDV-1 and BVDV-2, and at least 21 subtypes (1a-1u) for BVDV-1 and four subtypes (2a-2d) for BVDV-2 based on its 5'-untranslated region. This study aimed at investigating the prevalence and genetic analysis of BVDV in calf feces in the Republic of Korea (ROK).
View Article and Find Full Text PDFGlobal warming has increased the incidence and risk of tick-borne diseases in domestic animals and humans in the Republic of Korea (ROK). In this study, we investigated the prevalence of Anaplasma phagocytophilum in Holstein cattle (n = 214) in the ROK using specific PCR assays. A.
View Article and Find Full Text PDFGiardia duodenalis is an important zoonotic protozoan parasite that infects humans and other animals. This study was conducted to investigate the prevalence and molecular characterization of G. duodenalis infection in the feces of normal and diarrheic pre-weaned calves aged 1-60 days.
View Article and Find Full Text PDFAnaplasmosis is a tick-borne infectious disease that affects both human and animal health. This study was performed to characterize and investigate the prevalence of infection with Anaplasma bovis in Holstein cattle originating from two regions in the Republic of Korea (ROK). Blood samples (n = 151; 80 from Namwon and 71 from Jeju Island) were analyzed by polymerase chain reaction, and the prevalence of A.
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