Survey of bovine norovirus infections from diarrheic calves in South Korea, 2015–2017 / 대한수의학회지

This study examined complex infections with various enteropathogens and the genetic diversity of bovine norovirus (BNoV) in 932 fecal samples from diarrheic calves in South Korea. Overall, seventeen (1.8%) of the samples tested positive for BNoV following RT-PCR examination. All BNoV-positive samples were co-infected with other intestinal pathogens, including bovine Rotavirus, Giardia, Cryptosporidium, and Escherichia coli. The genetic diversity of the BNoVs shared high nucleotide identity (98.1–99.5%) and amino acid homology (93.5–98.1%) with genotype 2 BNoV (GIII.2) strains. In conclusion, BNoV infections with GIII genotypes were detected in complex infections of diarrheic calves in South Korea.

Survey of bovine norovirus infections from diarrheic calves in South Korea, 2015–2017

This study examined complex infections with various enteropathogens and the genetic diversity of bovine norovirus (BNoV) in 932 fecal samples from diarrheic calves in South Korea. Overall, seventeen (1.8%) of the samples tested positive for BNoV following RT-PCR examination. All BNoV-positive samples were co-infected with other intestinal pathogens, including bovine Rotavirus, Giardia, Cryptosporidium, and Escherichia coli. The genetic diversity of the BNoVs shared high nucleotide identity (98.1–99.5%) and amino acid homology (93.5–98.1%) with genotype 2 BNoV (GIII.2) strains. In conclusion, BNoV infections with GIII genotypes were detected in complex infections of diarrheic calves in South Korea.

Porcine ear necrosis syndrome by coinfection of porcine reproductive and respiratory syndrome virus and Staphylococcus hyicus

Porcine ear necrosis syndrome is characterized by erosive and ulcerative lesions at the margin or tip of the pinna. Three growing pigs of different ages exhibited retarded growth accompanied by reddening and necrosis of ear prior to death. Gross examination showed reddening, swelling, black discoloration, scaling, and variable-sized yellowish materials and edema in ear cross section. Microscopically, thrombosis, abscess, ulceration, epidermal hyperplasia, and dermal pyogranulomatous inflammation with an intralesional bacterial colony were observed. Staphylococcus hyicus was isolated in all pigs' ears and porcine reproductive and respiratory syndrome virus was detected by PCR and immunohistochemistry.

A case of malignant dysgerminoma in a slaughtered dairy cow / 대한수의학회지

An abnormally enlarged right ovary and a mass in fat surrounding the right kidney were discovered in a dairy cow during routine postmortem examination at slaughter. The ovary was dark reddish and multinodular in shape. Numerous cystic structures were identified in the mass. Histopathologically, the ovary was completely replaced with large, uniform, polyhedral neoplastic cells containing vesicular nuclei and prominent nucleoli. The mitotic index was high. In the lymphatic vessels, tumor emboli were observed. Another mass in the fat surranding the right kidney had the same histological features as the ovarian mass. This animal was diagnosed with malignant dysgerminoma and metastasis to other peritoneal organs.

Genetic Typing of Bovine Viral Diarrhea Viruses (BVDV) Circulating in Korea

To characterize the genetic diversity of bovine viral diarrhea viruses (BVDV) circulating in Korea, 11 BVDV isolates were obtained from 467 field samples collected during 2005~2006 in Korea. All of the BVDV isolates were identified as non-cytopathic (non-cp) BVDV biotypes. The 5' noncoding region (NCR) genes of the isolates were sequenced and analyzed. In total, ten BVDV isolates were typed as BVDV-1 by comparing the genomic sequences to the 5' NCR. One isolate (05R169) showed 98.6% nucleotide sequence identity with the BVDV-2 reference strain and was therefore typed as BVDV-2. Our results indicate that BVDV-1 is the main genotype circulating in the cattle population of Korea.

The seroprevalence of Japanese encephalitis virus in goats raised in Korea

Japanese encephalitis virus (JEV) causes a mosquitoborne viral zoonosis that is becoming increasingly important to public health in east and south Asia. Although JEV is primarily associated with reproductive failure in swine, JEV infection can cause fever and headache in humans and is associated with aseptic meningitis and encephalitis. The exact mode of transmission, including host range and possible source of viral amplification within livestock, is still not completely clear. This study consisted of a serological survey of JEV infection in goats. A total of 804 goat serum samples were collected from 144 farms in Korea between May 2005 and May 2006. The incidence of positive cases was 12.1% (97 out of 804 goats). The seroprevalence of JEV infection in the 144 farms screened was 31.3% (45/144), indicating that JEV infection is frequent in goat farms in Korea. In addition, three districts of Korea (mainly in the southern region) had a higher seroprevalence of JEV compared to other areas. The results suggest that goats could be monitored epidemiologically as a sentinel animal for JEV transmission in Korea.

Serological Survey of Bovine Coronavirus in Korea

Bovine coronavirus (BCoV) is a causative agent of entero-pathogenic diarrhea in young calves and winter dysentery (WD) in adult cattle. In this study, we conducted a nationwide sero-epidemiological survey of BCoV infection in Korea. In total, 3,029 bovine sera collected between October and December 2005 were screened for the presence of antibodies against BCoV using a hemagglutination inhibition (HI) test. Half (50.0%) of individual cattle tested were positive for BCoV. The regional distribution of the seroprevalence of positive HI antibodies was 55.7% (234/420) in Gyeonggi, 53.0% (316/596) in Jeonra, 51.9% (374/720) in Chungcheong, 48.5% (401/827) in Gyeongsang, 43.9% (79/180) in Jeju, and 38.1% (109/286) in Gangwon Province. Analyzing the distribution of HI titer according to the age of the cattle showed the highest BCoV seropositive rate in 5-year-old cattle, and the incidence of cattle with an HI antibody titer of 1:160 or above was 12.1%.

Seroprevalence of antibodies to Neospora caninum in dogs and raccoon dogs in Korea

Neospora caninum is an important cause of abortion in cattle, and dogs are its only known definitive host. Its seroprevalence among domestic urban and rural dogs and feral raccoon dogs (Nyctereutes procyonoides koreensis) in Korea was studied by indirect fluorescent antibody test (IFAT) and by the neospora agglutination test (NAT), respectively. Antibodies to N. caninum were found in 8.3% of urban dogs and in 21.6% of dogs at dairy farms. Antibody titers ranged from 1: 50 to 1: 400. Antibodies to N. caninum were found in six (23%) of 26 raccoon dogs. However, the potential role of raccoon dogs as a source of horizontal transmission of bovine neosporosis needs further investigation. The results of this study suggest that there is a close relationship between N. caninum infection among dairy farm dogs and cattle in Korea. This study reports for the first time upon the seroprevalence of N. caninum infection in raccoon dogs in Korea.