Genetic and pathogenic characterization of Akabane viruses isolated from cattle with encephalomyelitis in Korea.

A large-scale outbreak of Akabane viral encephalomyelitis in cattle was reported in the southern part of Korea in 2010. Fifteen Akabane virus (AKAV) strains were isolated from the brain and spinal cord samples by using BHK-21 and/or HmLu-1 cells. To examine the genetic relationships and characteristics of the isolates, nucleotide sequences of the S, M, and L segments of the 15 isolates were determined and analyzed.

Low pathogenic H7 subtype avian influenza viruses isolated from domestic ducks in South Korea and the close association with isolates of wild birds.

We characterized low pathogenic avian influenza (LPAI) viruses of the H7 subtype that were isolated from domestic ducks and wild birds in South Korea from 2008 to 2011. A total of 20 H7 viruses were collected from live-bird markets (LBMs), duck farms and wild-bird habitats using avian influenza (AI) surveillance and epidemiological approaches. A phylogenetic analysis of the H7 viruses that were isolated from domestic ducks and wild birds demonstrated that they were separated into 12 genotypes (A-D and Wb-1-8, respectively), indicating genetic diversity.

Highly pathogenic avian influenza (H5N1) outbreaks in wild birds and poultry, South Korea.

Highly pathogenic avian influenza (H5N1) among wild birds emerged simultaneously with outbreaks in domestic poultry in South Korea during November 2010-May 2011. Phylogenetic analysis showed that these viruses belonged to clade 2.3.

Human telomerase reverse transcriptase-immortalized porcine monomyeloid cell lines for the production of porcine reproductive and respiratory syndrome virus.

Porcine reproductive and respiratory syndrome virus (PRRSV) shows highly restricted cell tropism and targets subpopulations of differentiated macrophages such as porcine alveolar macrophages (PAM) in the natural host. Although primary PAM cells would be ideal for in vitro virus production, they are not only difficult and expensive for establishment but cannot be frozen reliably for long-term storage and use. Apart from PAM cells, African green monkey kidney derived Marc-145 cells are used commonly for virus propagation.

H5N1 subtype highly pathogenic avian influenza virus isolated from healthy mallard captured in South Korea.

On December 7, 2010, H5N1 highly pathogenic avian influenza virus was isolated from a healthy mallard captured at the Mankyung River in South Korea. Phylogenetic analysis showed that this virus was classified into clade 2.3.

Hepatic yersiniosis caused by Yersinia enterocolitica 4:O3 in an adult dog.

A 2-year-old Pekinese dog was diagnosed with hepatic yersiniosis. Grossly, white-to-yellow nodules consisting of degenerated inflammatory cells, cell debris, and bacterial clumps were scattered throughout the liver. Histopathologically, suppurative and necrotizing hepatitis was apparent.

Detection and characterization of bovine-like coronaviruses from four species of zoo ruminants.

Five coronaviruses (CoVs) were detected in diarrheal feces from four zoo ruminant species: one wisent (Bison bonasus), two Himalayan tahr (Hemitragus jemlahicus), one sitatunga (Tragelaphus spekii), and one nyala (Tragelaphus angasii). We sequenced and analyzed the spike (S) and hemagglutinin/esterase (HE) genes of these viruses and compared the nucleotide (nt) and deduced amino acid (aa) sequences with those of other bovine CoV (BcoV) strains. Comparison of the entire deduced aa sequences of the S and HE glycoproteins revealed no specific differences that would account for discrimination between bovine-like CoV strains from zoo ruminants and BcoVs strains.

Characterization and phylogenetic analysis of Bovine viral diarrhea virus in brain tissues from nonambulatory (downer) cattle in Korea.

Between August 2008 and May 2009, 386 brain and serum samples from adult cattle (2-7 years old) showing a variety of clinical signs of downer cow syndrome were received by the National Veterinary Research and Quarantine Service. All brain samples were tested for the presence of Bovine viral diarrhea virus (BVDV) by reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and antigen capture ELISA (Ag-ELISA). The BVDV nucleic acid was detected in 54 of 386 (15.

Myocarditis by nematodes infection, presumably Sarconema eurycerca, in a wild whooper swan (Cygnus cygnus) in Korea.

A dead whooper swan was found in an area of cropland near a stream and was submitted to the National Veterinary Research and Quarantine Service (NVRQS) in Korea. The affected animal was in relatively good condition. Grossly, the heart was enlarged and had pale and dark red stripes.

Characterization of H5N2 influenza viruses isolated in South Korea and their influence on the emergence of a novel H9N2 influenza virus.

We characterized low pathogenic avian influenza (LPAI) H5N2 and H9N2 viruses isolated in South Korea from 2008 to 2009. Genetic analysis of the H5N2 viruses isolated from wild birds and domestic ducks demonstrated that they were related to the recently isolated southern Chinese LPAI H5 viruses and various influenza viruses circulating in Eurasia. Three H9N2 viruses obtained at live bird markets and duck farms were reassortant viruses generated from the H5N2 viruses of domestic ducks and the H9N2 virus endemic in Korean chickens.

A molecular analysis of European porcine reproductive and respiratory syndrome virus isolated in South Korea.

In a situation where European genotype of porcine reproductive and respiratory syndrome virus (PRRSV) has recently emerged in South Korea, this study aims to understand variations in and relatedness among 25 European (EU) genotype 1 PRRSV isolates obtained from Korean pig farms during the period ranging from 2006 to 2009 for their sequences of nonstructural protein 2 (NSP2), open reading frames (ORF) 5 and 7, which, in turn, were compared with those of published Korean type 1 PRRSV isolates (CP6874, IV3140 and KNU07) and other EU PRRSV strains. The sequence data revealed that all Korean type 1 isolates were found to possess notable 19 amino acid deletions within NSP2 between positions 748 and 766. Based on the complete ORF5 sequences, the results showed that the Korean isolates amounted to 82.

Generation of a porcine alveolar macrophage cell line for the growth of porcine reproductive and respiratory syndrome virus.

Porcine reproductive and respiratory syndrome virus (PRRSV) has a marked tropism for cells of the monocyte-macrophage lineage and accordingly, replicates in fully differentiated alveolar macrophages in the natural host. Despite the identification of several putative receptors for PRRSV on porcine alveolar macrophages (PAM), only CD163 was found to be able to make non-permissive cells susceptible to PRRSV, indicating a requirement for CD163 in productive infection. Interestingly, the preliminary experiments revealed that the immortalized PAM cell line, which was previously shown to fail to support PRRSV replication, does not express detectable levels of CD163.

Phylogenetic analysis and characterization of Korean orf virus from dairy goats: case report.

An outbreak of orf virus infection in dairy goats in Korea was investigated. Suspected samples of the skin and lip of affected goats were sent to the laboratory for more exact diagnosis. Orf virus was detected by electron microscopy and viral DNA was identified by PCR.

Genetic relatedness of H6 subtype avian influenza viruses isolated from wild birds and domestic ducks in Korea and their pathogenicity in animals.

We report the genetic characterization of H6 avian influenza (AI) viruses isolated from domestic ducks and wild birds in Korea between April 2008 and April 2009. A phylogenetic analysis showed that the H6N1 viruses of wild birds and domestic ducks were of the same genotype (K-1) and were similar to the H6N1 virus isolated from a live poultry market in 2003, as six of the eight gene segments of those viruses had a common source. However, the H6N2 viruses of domestic poultry were separated into four genotypes (K-2a, K-2b, K-2c and K-2d) by at least a triple reassortment between influenza viruses of low pathogenicity from Korean poultry (H9N2 and H3N2) and viruses from aquatic birds.

Molecular epidemiology of rabies virus isolates from South Korea.

A molecular epidemiological study was performed on 13 Korean virus isolates, which were collected from wild and domestic animals diagnosed as rabid between 1998 and 2004. Seven samples were from domestic animals such as dogs and cattle infected by rabid raccoon dogs (Nyctereutes procyonoides koreensis), and the rest of the six samples were from raccoon dogs in the wild. The study was carried out based on the comparison of nucleotide and amino acid sequences of nucleoprotein (N) and glycoprotein (G) coding regions and nucleotide sequence of the G-L intergenic (Psi) non-coding region of the isolates.