• Journal of Veterinary Clinics
• /
• v.32 no.1
• /
• pp.78-84
• /
• 2015

Although researches have highlighted the important role of enhanced farm biosecurity to reduce the severity and prevalence of diseases in livestock, to date there has been little study in Korea on farmers' adoption of biosecurity measures to control porcine reproductive and respiratory syndrome virus (PRRSV) infection. To mitigate the risk of PRRSV infection in pigs, the risk factors by which PRRSV is introduced in pig farms must be determined. The primary aim of this study was to investigate pig producers' perceptions about on-farm biosecurity practices. We also analyzed data obtained from a cross-sectional study on 196 farrow-to-finish farms conducted between March 2013 and February 2014 to identify risk factors for PRRSV infection at farm level. Standardized questionnaires with information about basic demographical data and management practices were collected in each farm by on-site visit of trained veterinarians. Farms were classified as negative or positive through the use of infection profiles that combined data on PCR positive pigs and serological testing including antibody titer, sero-conversion pattern at each age category, and vaccination status. Data on biosecurity practices, farm management and environmental characteristics were analyzed using multivariate ordinal logistic regression. Generally, the biosecurity level in the pig farms included in this study were insufficient to reduce/prevent the risk of PRRSV infection given the high pig density areas and the considerable extent of vehicle movement. Factors associated with PRRSV infection were those where owners used on-farm vaccination programs had a lower risk of infection (OR = 0.19, 95% CI 0.06-0.61). The results from the analysis may guide to tailor biosecurity measures in the reduction or prevention of PRRS to the specific circumstances of pig farms in different localities of the world. To the best knowledge of the authors, this is the first study to report information on the biosecurity practices currently implemented on Korean pig farms.

• Korean Journal of Veterinary Research
• /
• v.38 no.2
• /
• pp.314-318
• /
• 1998

An establishment of effective control measures to PRRSV infection in swine industry depends on a sensitive and specific diagnosis to detect either viral antigen and/or antibodies to PRRSV. Several diagnostic methods are available to detect antibodies against PRRSV, including IPMA, IFA and ELISA tests have been successfully developed. Sensitivity of the indirect immunofluorescent assay in MA-104 cells using Korean field isolate PL96-1 was superior to that of VR-2332 and field isolate PL96-2. Sensitivity and specificity of the IFA test with PL96-1 were comparable to those of commercial ELISA test kit but ELISA test was more sensitive for the detection of declining antibodies to PRRSV in finishing pigs. In this study we concluded that IFA and ELISA test could be utilized to detect antibodies to PRRSV and the results generated from these two tests were comparable and there were no significant difference between these two tests.

• Microbiology and Biotechnology Letters
• /
• v.37 no.3
• /
• pp.287-292
• /
• 2009

The nucleocapsid (N) protein of porcine reproductive and respiratory syndrome virus (PRRSV) is a basic multifunctional protein which has been reported to be a serine phosphoprotein with yet-identified functions. As a first step towards understanding the general role of N protein phosphorylation during virus replication, the non-phosphorylated mutant N gene was constructed by mutating all serine residues to alanine. This recombinant N protein was identified to be unphosphorylated, confirming that serine residues truly function as core amino acids responsible for N protein phosphorylation. The PRRSV N protein has been shown to possess the biological features of nuclear localization and N-N homodimerization which individually play critical roles in virus infection. In the present study, therefore, it was attempted to investigate whether these two properties of the N protein are modulated by its phosphorylation status. However, experimental results showed that the non-phosphorylated N protein was still present in the nucleus and nucleolus, and was able to associate with itself by non-covalent interactions. Taken together, the data suggest phosphorylation-independent regulation of N protein nuclear transport or oligomerization, thereby implying the potential involvement of phosphorylation in regulating the activities of the N protein at other levels including RNA-binding capacity.

• Korean Journal of Veterinary Research
• /
• v.37 no.4
• /
• pp.765-772
• /
• 1997

제주지역 돼지에서 각종 전염성 질병 원인체에 대한 항체를 조사하여 그간 전염성 병원체에 대한 역학조사가 미진하였던 부분을 보완하여 질병의 분포를 파악하고자 1995년부터 1996년에 걸쳐 제주도 전역에서 돼지의 혈청을 채취하여 각종 병원체에 대한 항체 분포율을 조사하였다. 본 연구에서 검사한 돼지 혈청 시료에서는 돼지 오제스키병 바이러스에 대한 항체는 전혀 검출되지 않았다. 돼지 콜레라바이러스에 대한 항체는 기대 수준 이하로 낮아 백신접종이 원활히 수행되고 있지 않음을 시사하였으며 특히 농장에 따라 항체 보유돈과 항체 음성돈이 혼재하는 농장과 항체가 전혀 검출되지 않는 농장 등 돼지 콜레라 방역의 사각지대가 존재할 가능성이 있음을 보여주었다. 유 사산 원인체인 돼지 파보바이러스 및 뇌심근염에 대한 항체가가 다양하게 나타나 일부 문제가 있을 것으로 사료되었다. 돼지 생식기호흡기증후군(PRRS) 바이러스에 대한 항체 분포율은 내륙 보다 다소 낮게 나타났고, 돼지 influenza virus, 위축성 비염, 흉막 폐염 등 각종 세균성 질환에 대한 항체수준도 다양하게 나타났다. 본 혈청학적인 연구결과는 제주지역에서의 양돈방역 정책수립 및 질병방제의 기초자료로 유용하게 이용될 것으로 사료된다.

• Development and Reproduction
• /
• v.20 no.4
• /
• pp.297-304
• /
• 2016

Lectins belong to the pattern-recognition receptors (PRRs) class and play important roles in the recognition and elimination of pathogens via the innate immune system. Recently, it was reported that lily-type lectin-1 is involved when a pathogen attacks in the early immune response of fish. However, this study is limited to information that the lectin is involved in the innate immune response against viral infection. In the present study, the lily-type lectin-2 and -3 of Oplegnathus fasciatus (OfLTL-2 and 3) have been presented to be included B-lectin domain and two D-mannose binding sites in the amino acid sequence that an important feature for the fundamental structure. To investigate the functional properties of OfLTLs, the tissue distribution in the healthy rock bream and temporal expression during early developmental stage analysis are performed using quantitative real-time PCR. OfLTL-2 and 3 are predominantly expressed in the liver and skin, but rarely expressed in other organ. Also, the transcripts of OfLTLs are not expressed during the early developmental stage but its transcripts are increased after immune-related organs which are fully formed. In the challenge experiment with RBIV (rock bream iridovirus), the expression of OfLTLs was increased much more strongly in the late response than the early, unlike previously known. These results suggest that OfLTLs are specifically expressed in the immune-related tissues when those organs are fully formed and it can be inferred that the more intensively involved in the second half to the virus infection.