Jae-Ku Oem

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. Complete sequence analysis of the 15 AKAV isolates showed 99.9-100% amino acid identities, indicating that the 15 isolates originated from a single strain. The S and M RNA segments of a representative isolate (AKAV-7/SKR/2010) were also compared with the segments of representative reference sequences. This AKAV-7/SKR/2010 strain showed the highest identity with the Iriki and KM-1/Br/06 strains. Neighbor-joining phylogenetic trees of S and M RNA segments were constructed. Four representative AKAV isolates were classified into subgroup Ia, which contains the Iriki and KM-1/Br/06 strains recognized to cause encephalomyelitis in calves and adult cattle in Japan. Moreover, experimental intraperitoneal infection was performed using the AKAV-7/SKR/2010 and AKAV-17/SKR/2010 strains to assess pathogenesis in suckling mice. The 2 isolates, genetically related to the Iriki strain, were neurovirulent and caused neurological signs in suckling mice. In contrast, the 93FMX strain and the K0505 strain, related to the OBE-1 strain, were avirulent in mice. The present results indicate that these isolates most likely had originated from the Iriki strain and are closely related to the Iriki strain both genetically and pathogenically.

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. To reveal the genetic characteristics of the Korean strain (ORF/09/Korea), the sequences of the major envelope protein (B2L) and orf virus interferon resistance (VIR) genes were determined and then compared with published reference sequences. Phylogenetic analysis revealed that the ORF/09/Korea strain was closest to the isolates (Taiping) from Taiwan. This is believed to be the first report on the molecular characterization of orf virus in Korea.

Genome Sequence of Bovine Viral Diarrhea Virus Strain 10JJ-SKR, Belonging to Genotype 1d

ABSTRACT Here, we report the complete genome sequence of a bovine viral diarrhea virus (BVDV) belonging to genotype 1d, strain 10JJ-SKR, which was isolated from cattle. The complete genome is 12,267 nucleotides (nt) in length, with a single large open reading frame. This is the first report of a BVDV belonging to genotype 1d and will enable further study of the molecular and epidemiological characteristics of this virus.

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

Abstract 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. In addition, the 99.9% aa identity among the five CoV strains revealed that the ruminants were infected by the same strain. Phylogenetically, bovine-like CoVs belong to group 2a CoVs, which are related most closely to the BcoV strains recently isolated in Korea. These data suggest that cattle are potential reservoirs for CoVs that are capable of infecting zoo ruminants.

Complete Genome Sequences of Two Bovine Viral Diarrhea Viruses Isolated from Brain Tissues of Nonambulatory (Downer) Cattle

ABSTRACT Here, we report the complete genome sequences of two bovine viral diarrhea viruses (BVDVs) (strains 11F011 and 12F004) isolated from brain tissues from nonambulatory (downer) cattle. The complete genomes of strains 11F011 and 12F004 contain 12,287 nucleotides (nt) with a single large open reading frame and 12,301 nt with a single large open reading frame, respectively. Phylogenetic analysis indicated that these strains belong to the BVDV-2a and -1b genotypes, respectively.

Complete genome analysis of three live attenuated Rinderpest virus vaccine strains derived through serial passages in different culture systems.

ABSTRACT The genomes of three South Korean Rinderpest virus vaccine strains (L72, LA77, and LA96) were analyzed in order to investigate their genetic variability. These three vaccine strains were all derived from the same virus strain origin (Fusan) through repeated passages in different culture systems. The full genome length of the three strains was 15,882 nucleotides, and the sequence similarity between the three South Korean RPV strains at the nucleotide level was 98.1 to 98.9%. The genetic distance between Nakamura III, L72, LA77, LA96, and LATC06 and the Kabete strain was greater than that between the Fusan and Kabete strains for the P, V, and C genes. The difference in pathogenicity among these strains might be due to the V gene, which has a positive (>1) selection ratio based on the analysis of synonymous (dS) and nonsynonymous (dN) substitution rates (dN/dS ratio [ω]).