• 한국동물위생학회지
• /
• 제45권3호
• /
• pp.201-209
• /
• 2022

An epidemiological study was conducted to investigate five diarrhea-causing pathogens (coronavirus, rotavirus, E. coli, Cryptosporidium, Giardia) using a rapid diagnostic kit in Hanwoo calves with diarrhea in Chungcheongbuk-do, Korea, from 2018 to 2021. A total of 22,417 fecal samples were collected from calves under 1 year of age; of those, 13,518 (60.3%) were positive for five bovine diarrhea antigens. The antigen positivity rates for rotavirus, coronavirus, E. coli, Giardia, and Cryptosporidium were 34.5%, 11.0%, 8.2%, 4.7%, and 2.0%, respectively. The prevalence of the five pathogens in calves was statistically higher in autumn and winter. The highest prevalence of the pathogens was observed in the under 1 month age group, and the incidence of diarrhea decreased with age. Rotavirus was a major pathogen in calves under 1 month of age, whereas the prevalence of E. coli increased with age. This study provides epidemiological evidence of the prevalence of calf diarrheal pathogens in Chungcheongbuk-do, Korea, which will facilitate early diagnosis and development of measures against calf diarrhea.

• Journal of Animal Science and Technology
• /
• 제51권5호
• /
• pp.407-412
• /
• 2009

본 연구는 송아지 설사병의 주요원인체 중 소로타바이러스(bovine rotavirus; BRV)와 소코로나바이러스(bovine coronavirus; BCV)에 대한 난황항체를 생산하고 이의 면역 특이성을 확인하고자 실험을 실시하였으며, BRV 및 BCV를 2주 간격으로 5회 산란계에 근육주사를 실시하여 혈청과 난황내의 특이 항체 형성 유무를 확인하였다. 실험 6주차에 면역한 산란계로부터 획득한 혈청을 이용하여 교차반응 시험을 실시한 결과, BRV 및 BCV를 면역하여 얻은 혈청은 각각 BRV 및 BCV 항원과만 특이적인 결합반응을 보였다. 면역에 따른 혈청항체 및 난황항체의 수준은 실험 8~12주차에 최고도에 달했고, BRV에 대한 항체의 경우 혈청과 난황내에서 면역 후 12주째에 각각 약 104,000과 107,000의 역가 수준을 보였으며, BCV의 경우 8주째에 각각 약 145,000과 155,000의 수준을 보였다. BRV 및 BCV에 대한 중화능력 유무 확인을 위하여 분리된 난황항체를 이용하여 혈구응집억제반응 시험을 실시한 결과, BRV 및 BCV에 대한 혈구응집억제 희석비가 각각 5,120 및 1,260으로 면역하지 않은 대조군에 비하여 8배 이상 높은 중화력을 나타냈다. 이러한 결과를 종합하면, 산란계에 BRV 및 BCV를 면역하여 얻어진 난황항체는 BRV 및 BCV에 대한 면역 특이성을 가지고 중화할 수 있는 능력이 있으며, 이러한 난황항체는 BRV 및 BCV의 증식을 효과적으로 억제시킬 수 있어 임상에 적용할 경우 유용할 것으로 사료된다.

• 한국동물위생학회지
• /
• 제22권3호
• /
• pp.239-245
• /
• 1999

The reverse transcriptase polymerase chain reaction (RT-PCR) was used for the detection of bovine coronavirus (BCV) in fecal samples by using reverse transcriptase and two primers which flanked M gene sequence of 407bp. RT-PCR detected bovine coronavirus specifically, but did not detect mouse hepatitis virus (MHV), transmissible gastroenteritis virus (TGEV), and bovine rotavirus (BRV). The M gene sequences of MHV are homologus to that of BCV, but minor differences exist in the primer regions, preventing annealing of the primers. Detection of BCV using RT-PCR was compared with ELISA and the agreement of BCV detection by RT-PCR and ELISA was 95.3%. RNA detection in positive clinical specimens was significantly better by PCR than immunological detection of BCV by ELISA.

• 한국동물위생학회지
• /
• 제31권3호
• /
• pp.265-272
• /
• 2008

Among calves' diseases, digestive diseases most frequently occur in Korea, and especially viral diarrhea is one of the most important diseases. This study was conducted to get some basic information for the control of the viral diarrhea in calves. The samples were obtained from 319 calves with clinical diarrhea from 195 farms in Gyeongnam south area (Gosung, Tongyung, Hadong) from June 2005 to August 2006, Viral detection was examined by polymerase chain reaction (PCR), Etiological viruses were detected from 171(53,6%) of 319 calves, and bovine rotavirus (BRV) were 130 (40,8%) and bovine viral diarrhea virus (BVDV) 41 (12,9%), and no coronavirus was confirmed, Statistical difference was found in BRV detection between summer (32.6%) and winter (57.7%). However there was no seasonal difference in BVDV. In detection rate of the calves under 19days, BRV was highest (55.1%), but BVDV lowest (5.1%). No big difference was in rate among herd size. However, BRV was lowest (26.8%) in the group over 51 heads, but BVDV was highest (19.5%) in the same.

• Journal of Animal Science and Technology
• /
• 제63권4호
• /
• pp.864-871
• /
• 2021

Infectious calf diarrhea is one of the most significant diseases of neonatal calves. This study is conducted to identify the prevalence of pathogens in calf diarrhea for 2 years. A total of 544 feces samples from Korean native beef calves were obtained to investigate selected seven pathogens causing calf diarrhea: bovine rotavirus, bovine coronavirus, Cryptosporidium parvum, bovine viral diarrhea virus, Eimeria species, Escherichia coli K99, and Salmonella species. The presence of diarrhea, the number and species of detected pathogens, and the calves' ages were analyzed using various statistical methods depending on the case. Of the 544 calves, 340 calves (62.5%) had normal feces and 204 calves (37.5%) had diarrhea. The presence of pathogens was significantly associated with diarrhea (p < 0.01) and fecal scores and the number of detected pathogens showed a significant linear trend (p < 0.001). Of the 7 target pathogens, 6 were detected in samples, but only C. parvum (p = 0.001) and bovine rotavirus (p < 0.001) were found at significantly higher rates in diarrheic calves than in non-diarrheic calves. Only Eimeria spp. showed a significant linear trend between the detection rate of the pathogen and the age groups (p < 0.05).

• 대한수의학회지
• /
• 제36권2호
• /
• pp.395-403
• /
• 1996

Monoclonal antibodies(MAbs) against field isolates of the bovine rotavirus A strain(G6), V strain(G10) and reference I-801 strain(G8) were produced and characterized. Six MAbs(4C2, 4D9, 5E1, 5E7, 5D5, 3E4) against A strain had neutralizing activity and reacted only with the G6 bovine rotaviruses determined by fluorescence focus neutralization (FFN) test. Otherwise, five neutralizing MAbs(1G2, 2G6, 5E2, 5E12, 5H7) against I-801 strain neutralized the G6 and G8 bovine rotaviruses. Five non-neutralizing MAbs(5F12, 7F12, 5E11, 2A11, 2B12) were VP6-specific and cross-reacted with all bovine and porcine rotaviruses examined by fluorescence antibody(FA) test. None of the MAbs reacted with bovie viral diarrhea virus(BVDV) and bovine coronavirus(BCV) determined by FA and FFN test.

• 한국동물위생학회지
• /
• 제42권2호
• /
• pp.93-112
• /
• 2019

Calf diarrhea is a common disease in young claves and is still a major cause of productivity and economic loss in livestock farms. Fecal samples from Korean native cattle (n=100) with diarrhea from 64 farms in Gwangju area, Korea from september 2017 to December 2018 were examined for shedding of important protozoan parasitic, viral and bacterial pathogens using culture, rapid test kit and PCR methods. Of 57 (89.1%) of the 64 Korean native cattle farms examined had samples infected with at least one of the investigated pathogens. Among 100 fecal samples, 88 samples were positive for at least one the twelve pathogens and 51 samples were simultaneously positive for two or more pathogens by culture and PCR assay. Bovine group A rotavirus (BRV) was the most common pathogen, found in 43/100 (43.0%) samples on 32/64 (50.0%) farms. Subsequently, kobuvirus (30.0%), pathogenic E. coli (29.0%), bovine parvovirus (17.0%), Giardia spp. (13.0%), Eimeria spp. (10.0%), Clostridium perfringens type A (8.0%), bovine torovirus (8.0%), bovine viral diarrhea virus (6.0%), bovine coronavirus (5.0%), bovine norovirus (2.0%) and Cryptosporidium spp. (2.0%) were detected. Nebovirus, kırklareli virus, bovine adenovirus, Salmonella spp. and intestinal parasites were not detected. Of the 72 calves sampled in this age group, 64 (88.9%) samples were positive for at least one enteropathogen. BRV was identified in 34/72 (47.2%) samples from 27/48 (56.3%) farms. Subsequently, pathogenic E. coli (30.6%), kobuvirus (29.2%), BPaV (22.2%), Giardia spp. (15.3%), Eimeria spp. (9.7%), BVDV (6.9%), Cl. perfringens type A (6.9%), BCoV (4.6%) and Cryptosporidium spp. (2.8%) were detected in fecal samples. A total of ninety-six strains of E. coli were isolated from one hundred fecal samples collected from Korean native cattle with diarrhea. The presence of stx1, stx2, eaeA, LT, STa, STb, ehxA, saa, F4, F5(K99), F6, F17, F18 and F41 genes in the isolates was investigated by PCR. Out of ninety-six E. coli isolates screened for specific genes, 30 strains E. coli were identified to harbor shiga toxin-producing E. coli (STEC) 7 (7.3%), enterohemorrhagic E. coli (EHEC) 8 (8.3%), enteropathogenic E. coli (EPEC) 6 (6.3%), enterotoxigenic E. coli (ETEC) 2 (2.1%) and STEC/ETEC hybrid 7 (7.3%). This study provides epidemiological estimates of the prevalence of Korean native cattle's enteropathogens in Gwangju area, Korea, which would be used for cattle farmers and veterinarians to select appropriate therapeutic method.

• 한국동물위생학회지
• /
• 제39권1호
• /
• pp.35-39
• /
• 2016

The purpose of this study was to survey on infection status of pathogens of diarrhea from Korean indigenous goat. A total of 800 fecal samples was collected from 50 farms from January to October 2015 and was tested by automatic biochemical machine and polymerase chain reaction (PCR). The overall detection ratio of bacterial pathogens was 22.4% and viral pathogens was 16.3%, respectively. The detection ratio of Escherichia coli (E. coli), Salmonella spp., bovine viral diarrhea virus (BVDV), rotavirus and coronavirus were 21.5%, 0.9%, 7.6%, 5.6% and 3.0%, respectively. In the rates of mixed detection, single was 78.2%, double 8.4%, triple 11.6% and quadruple 1.8% in each sample and 38%, 12%, 16%, 20% in each farm, respectively.

• 한국동물위생학회지
• /
• 제40권1호
• /
• pp.21-25
• /
• 2017

The purpose of this study was to survey on infection status of pathogens of diarrhea from Korean indigenous goat. A total of 800 fecal samples was collected from 50 farms from January to November 2016 and was tested by automatic biochemical machine and polymerase chain reaction (PCR). The overall infection rates of parasitic, bacterial and viral pathogens was 13.0%, 23.0%, 11.3% and the rates of coccidia, Escherichia coli (E. coli), bovine viral diarrhea virus (BVDV), rotavirus and coronavirus were 13.0%, 23.0%, 5.3%, 8.8% and 2.6%, respectively. In the rates of mixed detection, single was 29.8%, double 5.1%, triple 2.8%, quadruple 1.1% in each sample, respectively.

• Journal of Microbiology and Biotechnology
• /
• 제12권3호
• /
• pp.463-469
• /
• 2002

Rotaviruses are the world-wide leading causative agents of severe dehydrating gastroenteritis in young children and animals. The outer capsid glycoprotein VP7 and inner capsid glycoprotein VP6 of rotaviruses are highly antigenic and immunogenic. An SFV-based expression system has recently emerged as a useful tool for heterologous protein production in mammalian cells, exhibiting a much more efficient performance compared to other gene expression systems. Accordingly, the current study adopted an SFV-based expression system to express the VP7 of a group A human rotavirus from a Korean isolate, and the VP6 of a group B bovine rotavirus from a Korean isolate, in mammalian cells. The genes of the VP6 and VP7 were inserted into the SFV expression vector pSFV-1. The RNA was transcribed in vitro from pSFV-VP6 and pSFV-VP7 using SP6 polymerase. Each RNA was then electroporated into BHK-21 cells along with pSFV-helper RNA containing the structural protein gene without the packaging signal. The expression of VP6 and VP7 in the cytoplasm was then detected by immunocytochemistry. The recombinant virus was harvested by ultracentrifugation and examined under electron microscopy. After infecting BHK-21 cells with the defective viruses, the expressed proteins were separated by SDS-PAGE and analyzed by a Western blot. The results indicate that an SFV-based expression system fur the VP6 and VP7 of rotaviruses is an efficient tool for developing a diagnostic kit and/or preventive vaccine.