혈청학적 분석을 통한 돼지 생식기호흡기증후군의 농장단위 감염유형

박최규,윤하정,이창희,정병열,이경기,김현수,Park, Choi-Kyu,Yoon, Ha-Chung,Lee, Chang-Hee,Jung, Byeong-Yeal,Lee, Kyoung-Ki,Kim, Hyun-Soo 대한수의학회 2008 大韓獸醫學會誌 Vol.48 No.1

Porcine reproductive and respiratory syndrome (PRRS) is the most economically important viral infectious disease in pig populations worldwide. This study was conducted to better understand the epidemic and dynamics of PRRS virus (PRRSV) on each farm and to evaluate the risk of PRRSV infection in Korea. Interviews with pig farmers were carried out to obtain PRRS vaccination programmes in 60 pig farms throughout Korea. Blood samples were also collected from the 59 pig farms to investigate outbreak patterns of each farm. Vaccination against PRRS was performed in 16.7% farms for breeding pigs and 8.3% of farms for nursery pigs. According to the seroepidemiological analysis, 56 (94.9%) out of 59 farms were considered to be affected by PRRSV infection. The results revealed that 68.9% of sows tested were seroconverted and interestingly, gilt herds had the highest seropositive rate (73%), suggesting that gilts may play a key role in PRRSV transmission in sow herds. Among the PRRS-affected piglet herds, 33 (55.9%), 14 (23.7%) and 6 (10.2%) farms were initially infected with PRRSV during the weaning, suckling and nursery period, respectively. It seems likely, therefore, that PRRSV infection predominantly occurs around the weaning period in piglet herds. Based on antibody seroprevalence levels in both sow and piglet groups, we were able to classify patterns of PRRSV infection per farm unit into 4 categories; category 1 (stable sow groups and non-infected piglet groups), category 2 (unstable sow groups and non-infected piglet groups), category 3 (stable sow groups and infected piglet groups), and category 4 (unstable sow groups and infected piglet groups). Our data suggested that 43 (72.9%) farms were analysed to belong to category 4, which is considered to be at high-risk for PRRS outbreak. Taken together, our information from this study will provide insight into the establishment of an effective control strategy for PRRS on the field.

원저 : 제주 지역 돼지 생식기 호흡기 증후군의 혈청학적 조사

윤성환 ( Sung Hwan Yoon ),손성원 ( Seong Won Sohn ),장원우 ( Won Woo Jang ),김성환 ( Seong Hwan Kim ),장소영 ( So Young Jang ),지영흔 ( Young Heum Jee ),김재훈 ( Jae Hoon Kim ),임윤규 ( Yoon Kyu Lim ) 한국수의공중보건학회 2010 예방수의학회지 Vol.34 No.4

Porcine reproductive and respiratory syndrome (PRRS) virus causes not only breeding disorder such as abortion, stillbirth and premature birth to pregnant sows but economic damage like high estrous return and low delivery rate. The presented study was conducted to confirm seroprevalence of PRRS in Jeju herds. PRRS positive rate was examined with pig serum from hog farms located in Jeju. Serum samples were extracted from the 11 of sow farms and 10 of hog farms, The groups were divided into 20, 40, 60, 80, 100 and older than 120 days of age and pregnant sows in hog farms. Anti-PRRSV antibody titers in sera were analyzed by ELISA. All the breeding farms and hog farms (10/10) showed PRRS positive except one breeding farm (1/11). Serological patterns determined by ELISA did not show any difference regardless of whether pigs were vaccinated or not. Nevertheless, the farms unvaccinated pigs displayed low productivity in terms of piglet loss rate and prolonged period of shipment. Therefore, vaccination against PRRSV appears to be a crucial factor in sanitary management of hog farms. Taken together, since PRRSV was spread widely in Jeju already, stabilization of sows by PRRS vaccination after adapting PRRSV free sow by all-in-all-out method in farms is recommended for the control strategy for PRRS.

돼지 생식기호흡기증후군 바이러스의 Nucleocapsid 단백질 발현 및 진단적 응용

박효선,한태욱,김현수,최강석,이은정,강신영,Park, Hyo-Sun,Hahn, Tae-Uook,Kim, Hyun-Soo,Choi, Kang-Seuk,Lee, Eun-Jeong,Kang, Shien-Young 대한수의학회 2003 大韓獸醫學會誌 Vol.43 No.1

Porcine reproductive and respiratory syndrome (PRRS) is characterized by reproductive failures in sows and respiratory problems in piglets. The nucleocapsid(N) protein, encoded by the open reading frame 7 (ORF7) gene, is known to be the most abundant and antigenic protein in PRRS virus. Therefore, it was suggested that the N protein could be a suitable candidate for the detection of PRRS virus-specific antibodies and diagnosis of PRRS. In the present study, the ORF7 gene encoding the N protein was cloned and expressed as a fusion protein with the glutathione S-transferase (GST) in Escherichia coli. The resulting GST-N recombinant protein was used as an antigen for an indirect sandwich enzyme-linked immunosorbent assay (i-ELISA). Expressed GST-N recombinant protein was migrated at 41 kDa and reacted with ORF7-specific monoclonal antibody by Western blotting. In order to increase the specificity of the ELISA for the detection of PRRS virus-specific antibodes, an i-ELISA was developed using an anti-GST antibody as a capture antibody. The sensitivity and specificity of developed i-ELISA were 92% and 96%, respectively. Based on these results, it was suggested that the i-ELISA is a simple and rapid test for screening a large number of swine sera for the anti-PRRS virus antibodies.

Seroprevalence of antibody to porcine reproductive and respiratory syndrome(PRRS) virus in the selected swine farms

Kim, Hyun-soo,Kim, Hae-jin,Jung, June-ho,Park, Bae-keun 충남대학교 수의과대학 동물의과학연구소 1997 動物醫科學硏究誌 Vol.5 No.-

PRRS virus의 항체양성율을 조사하기 위하여 27개의 농장으로부터 검사 의뢰된 848개의 돼지혈청을 간접형광항체법에 의한 PRRS virus에 대한 항체를 검사한 결과 전반적인 항체양성율은 43%(365/848) 이었으며, 돈군별 PRRS virus 항체양성율은 웅돈, 후보모돈, 모돈, 포유자돈, 이유자돈, 비육돈 및 육성돈에서의 항체양성율은 각각 44%(48/110), 58.5%(38/65). 30.1%(83/276), 24%(18/75), 32.9%(46/140), 62.5%(132/182) 이었다. 조사된 27개의 농장 중에서 소수(5/27)의 감염농장에서 급성의 감염증상을 보였으며 대다수의 감염농장에서는 만성적인 감염증상을 보였으며, 특히 육성돈과 비육돈군에서 이차감염에 의한 호흡기증상으로 증체율저하에 따른 출하일령(190-220)의 지연이 관찰되었다. 호흡기 증상은 가벼운 증상에서 부터 심한 증상까지 다양한 형태를 보였다. 또한 소수(3/27)의 농장에서는 PRRS증상이 없이 항체 양성을 나타내었다. 급성감염 농장을 제외하고 돈군 별 PRRS virus에 대한 항체 양성율은 육성 및 비육돈균, 후보모돈, 웅돈의 순서로 높았다.

돼지 생식기호흡기증후군바이러스의 농장단위 방역대책 수립을 위한 혈청학적 및 바이러스학적 감염유형 분석법 적용 및 비교

김성희(Seong Hee Kim),이창희(Changhee Lee),박최규(Choi-Kyu Park) 한국생명과학회 2009 생명과학회지 Vol.19 No.8

Porcine reproductive and respiratory syndrome virus (PRRSV) has plagued pig populations worldwide causing severe economical impacts. In order to establish effective strategies for prevention of PRRS, infection patterns on the herd level are primarily evaluated. In the present study, therefore, serological and virological analyses were conducted in 20 pig farms suffering from PRRS. Seroprevalence levels in each farm were grouped into 3 patterns: SN (Stable sow groups/Not infected piglet groups, SI (Stable sow groups and Infected piglet groups), and UI (Unstable sow groups and Infected piglet groups). The rates of each serological pattern were 15% (n=3), 10% (n=2), and 75% (n=15), respectively. In addition, the pattern analysis was extended to virological monitoring on the same farms that further included suckling pig groups. As a result, the infection pattern was classified into 4 categories: SNI (Stable sow groups/Not infected suckler groups/Infected piglet groups), SII (Stable sow groups/Infected suckler groups/Infected piglet groups), UNI (Unstable sow groups/Not infected suckler groups/Infected piglet groups), and UII (Unstable sow groups/Infected suckler groups/Infected piglet groups). The rates of each viroprevalence were estimated at 50% (n=10), 30% (n=6), 10% (n=2), and 10% (n=2), respectively. PRRSV viroprevalence results of suckling pig groups revealed that 8 farms were considered virus positive. In 2 farms among these farms, PRRSV appeared to be transmitted vertically to suckling piglets from their sows. In contrast, piglet-to-piglet horizontal transmission of PRRSV seemed to occur in sucking herds of the remaining farms. Thus, this virological analysis on suckling piglets will provide useful information to understand PRRSV transmission routes during the suckling period and to improve a PRRS control programs. Our seroprevalence and viroprevalence data found that infection patterns between sow and piglet groups are not always coincident in the same farm. Remarkably, 15 farms belonging to the UI seroprevalence pattern showed four distinct viroprevalence patterns (SNI; 7, SII; 4, UNI; 2 and UII; 2). Among these farms, 11 farms with unstable seroprevalence sow groups were further identified as the stable viroprevalence pattern. These results indicated that despite the absence of typical seroconversion, PRRSV infection was detected in several farms, implying the limitation of serological analysis. Taken together, our data strongly suggests that both seroprevalence and viroprevalence should be determined in parallel so that a PRRS control strategies can be efficiently developed on a farm level.

Effects of ozone, ultraviolet and an organic acid-based disinfectant against porcine reproductive and respiratory syndrome virus

( Yong Dae Yoon ),( Won Il Kim ) 한국동물위생학회 2013 韓國家畜衛生學會誌 Vol.36 No.3

A good level of biosecurity practice is important for efficient porcine reproductive and respiratory syndrome (PRRS) control. In the current study, disinfecting ability of ozone against PRRS virus (PRRSV) was evaluated in comparison with ultraviolet (UV) and an organic acid-based disinfectant to assess the possible use of ozone for disinfecting farm vehicles, equipments, and materials to reduce the risk of new virus introduction. For in vitro evaluation, the levels of infectious virus and viral RNA were determined on the swabs collected from the floor surface of each room treated with either ozone, UV or the disinfectant up to 30 min after contamination with 100 mL of VR2332 (105 TCID50/mL). For in vivo evaluation, 3, 4-week old, PRRS-free pigs were housed into those rooms right after the last swab collection. Then the pigs in each room were injected intramuscularly with the corresponding swab samples collected at the last time point and pooled per each room. Although ozone, UV, and the disinfectant significantly reduced the levels of PRRSV RNA contamination, ozone was most effective in removing the viral RNA. In addition, the virus collected after at least 10 min exposure to ozone failed to replicate in pigs while the virus collected after treatment with UV and the disinfectant for 30 min still replicated in pigs. Based on the results, it was concluded that ozone is more effective in inactivating PRRSV as compared with UV and the organic acid-based disinfectant.

Effects of ozone, ultraviolet and an organic acid-based disinfectant against porcine reproductive and respiratory syndrome virus

Yoon, Yong-Dae,Kim, Won-Il The Korean Society of Veterinary Service 2013 韓國家畜衛生學會誌 Vol.36 No.3

A good level of biosecurity practice is important for efficient porcine reproductive and respiratory syndrome (PRRS) control. In the current study, disinfecting ability of ozone against PRRS virus (PRRSV) was evaluated in comparison with ultraviolet (UV) and an organic acid-based disinfectant to assess the possible use of ozone for disinfecting farm vehicles, equipments, and materials to reduce the risk of new virus introduction. For in vitro evaluation, the levels of infectious virus and viral RNA were determined on the swabs collected from the floor surface of each room treated with either ozone, UV or the disinfectant up to 30 min after contamination with 100 mL of VR2332 ($10^5\;TCID_{50}/mL$). For in vivo evaluation, 3, 4-week old, PRRS-free pigs were housed into those rooms right after the last swab collection. Then the pigs in each room were injected intramuscularly with the corresponding swab samples collected at the last time point and pooled per each room. Although ozone, UV, and the disinfectant significantly reduced the levels of PRRSV RNA contamination, ozone was most effective in removing the viral RNA. In addition, the virus collected after at least 10 min exposure to ozone failed to replicate in pigs while the virus collected after treatment with UV and the disinfectant for 30 min still replicated in pigs. Based on the results, it was concluded that ozone is more effective in inactivating PRRSV as compared with UV and the organic acid-based disinfectant.

한국의 돼지생식기호흡기증후군(PRRS) 발생경향

한경수,류광수,박봉균,Han, Kyung-soo,Lyoo, Kwang-soo,Park, Bong-kyun 대한수의학회 1999 大韓獸醫學會誌 Vol.39 No.1

The 2,078 blood samples from 148 swine farms were collected and tested by IFA for porcine reproductive and respiratory syndrome(PRRS) virus antibody to know what type of PRRS prevails by the area. Clinically reproductive form of PRRS occurred in swine farms of 3/27, 3/87, and 2/34 in eastern, central and western areas, but the seroprevalence of those areas was different as 6.5%, 23.3%, and 17.6%, respectively. However, respiratory form of PRRS occurred more frequently, and the number of farms manifested with the respiratory form of PRRS in the eastern, central and western areas was 22/27, 71/87, and 30/34, respectively. The seroprevalence of that form of PRRS in the eastern, central and western areas was 52.2%, 67.1%, and 51.6%, respectively. Subsequently mixed form of PRRS occurred more frequently in the central area and the number of farms of eastern, central and western areas was 2/27, 13/87, and 2/34, respectively. The PRRS seroprevalence of the eastern, central and western areas was 58.6%, 54.0%, and 19.2%, respectively. Collectively the PRRS seroprevalence of eastern, central and western areas was 43.8%, 59.3%, and 38.2%, respectively. Overall seroprevalence of PRRS in Korea was 51.8%. In conclusion, the reproductive or the respiratory form of PRRS has been still in trouble in the Korean swine industry and PRRS control measures have to be taken in consideration.

번식돈에서의 돼지 생식기 호흡기증 바이러스 항체 분포 조사

박최규 ( Choi Kyu Park ),김현수 ( Hyun Soo Kim ) 한국가축위생학회 2004 韓國家畜衛生學會誌 Vol.27 No.1

Total 2,451 sera collected from pig farms nationwide were tested for the detection of porcine reproductive and respiratory syndrome(PRRS) virus antibodies. The results were analyzed between different geographic regions, types of breeding pigs, and different years. The overall seroprevalence of PRRS virus antibodies for 3 years was 32.4%(705/2,451). The seroprevalence of PRRS virus antibodies in years 2000, 2001, 2002, and 2004 was 33.4% (284/850), 38.6%(291/754), 33.3%(155/466), and 17.1%(65/381), respectively. The seropevalence of PRRS virus antibody in sow in years 2000, 2001, 2002 and 2003 was 31.7%, 28.4%, 29.6%, and 13.4%, respectively. The seropevalence of PRRS virus antibody in gilts in years 2000, 2001, 2002 and 2003 was 36.6%, 67.4%, 54.7%, and 33.9%, respectively. The seropevalence of PRRS virus antibody in boars in years 2000, 2001 and 2003 was 45.7%, 36.4%, and 100%, respectively. No boar serum sample was submitted for the diagnosis of PRRS virus antibody in the year 2000. High seroprevalence of the PRRS virus antibody in sow, gilts and boars indicates that the infected breeding pigs are the major source of the PRRS virus infection, and also play an important role in spreading the PRRS virus between fan mates or herds.

Comparison of immune cell populations in bronchoalveolar lavage cells and PBMC cytokine expressions in porcine reproductive and respiratory syndrome and porcine respiratory disease complex

Yang, Myeon-Sik,Jeong, Chang-Gi,Nazki, Salik,Mattoo, Sameer ul Salam,Lee, Sang-Myeong,Kim, Won-Il,Kim, Bumseok The Korean Society of Veterinary Service 2019 韓國家畜衛生學會誌 Vol.42 No.4

Porcine reproductive and respiratory syndrome (PRRS) is characterized by reproductive failure in sows and respiratory distress in all age pigs. Porcine respiratory disease complex (PRDC) is a disease caused by opportunistic bacterial infection secondary to a weakened immune system by a preceding respiratory infection. In this study, we tried to compare the immune responses in PRRS and PRDC groups to clearly characterize the disease severity. Eighty-five pigs were infected with various Korean field PRRS virus strains. Infected animals were classified into PRRS (n=32) and PRDC (n=53) groups based on lung lesions such as interstitial pneumonia, suppurative pneumonia, and pleuropneumonia. The immune cell population of bronchoalveolar lavage cells (BALc) was evaluated on 14 and 28 days post infection (dpi) and PMBC cytokine expression was measured on 0, 3, 7, 14 dpi to investigate early inflammatory reactions. Pulmonary lesion severity was negatively correlated with alveolar macrophage (AM) in both PRRS and PRDC groups on 14 and 28 dpi. AM in BALc was less populated in PRDC group on 28 dpi compared to PRRS group. AM in BALc was significantly less populated in PRDC group on 28 dpi compared to 14 dpi. In addition, cytotoxic T lymphocyte (CTL) in BALc was higher populated in PRDC group on 14 dpi and 28 dpi compared to PRRS group. In the case of PBMC cytokine TNF-α, IFN-α, IL-1β, IFN-γ, FoxP3, and IL-2, the PRRS group showed higher expression than the PRDC group on 7 dpi, 14 dpi, 7 dpi, 14 dpi, 14 dpi, and 14 dpi, respectively. On the other hand, in the case of IFN-β, IL-6, IL-8, IL-4, and IL-17, the PRDC group showed higher PBMC cytokine expression at 14 dpi, 7 dpi, 14 dpi, 3 dpi, and 3 dpi, respectively, than the PRRS group. Based on these results, our study could characterize differential immune responses in pigs with PRRS or PRDC.