• 대한수의학회지
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• 제39권1호
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• pp.111-117
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• 1999

A nation wide sero-epidemiological survey of porcine reproductive and respiratory syndrome(PRRS) was carried out to analyze the current status of the PRRS virus infections in the field using the indirect immunofluorescent antibody assay(IFA) with the field isolate PL96-1. Since the first report of the antibody detection to PRRSV in 1993, the prevalence of seropositive pigs has increased dramatically and the data indicate that over 21% of the pigs and around 60% of the farms showed seropositives to the PRRS virus. A slightly higher positive rate was recognized in breeders than fattenings and it might be due to the higher age at the time of testings. No significant regional differences were detected in the sero-epidemiological survey. Higher sero-positive rate in growers indicates that PRRSV infection in the field was common after weaning(around 40 days). However, the number of seropositive pigs were declined in fattening pigs. Sows showed around 26% of sero-positive rate that there is a higher chance of continuous virus circulation in the infected farms. Low rate of sero-positivity in boars(9.8%) implies that there is high demand in proper control measures to prevent virus spreading through breeding procedures such as natural or artificial insemination. Therefore it was concluded that PRRSV infection in domestic swine herds is endemic and the positive rate and economic loses will be increased by spontaneous infections in naive farms.

• Journal of Veterinary Science
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• 제21권4호
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• pp.68.1-68.8
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• 2020

A fluorescent microsphere-based immunochromatographic strip test (FICT) was developed for the rapid, sensitive, and quantitative detection of porcine reproductive and respiratory syndrome virus (PRRSV) antibodies at the pen-side. The assay was based on the formation of a sandwich immune-complex (anti-pig IgG-PRRSV antibodies-NSP7/N), which was validated by a comparison with IDEXX-ELISA using 3325 clinical specimens. The diagnostic specificity, sensitivity, and accuracy of FICT were 97.28, 93.41, and 94.95%, respectively. FICT showed a good correlation with the virus neutralization assay. Overall, a promising pen-side diagnostic tool was developed for the rapid and quantitative detection of PRRSV antibodies within 15 min.

• 대한수의사회지
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• 제46권3호
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• pp.279-287
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• 2010

돼지 번식기 및 호흡기 증후군 ( PRRS ; Porcine Reproductive and Respiratory Syndrome )은 우리나라를 포함한 전세계적으로 양돈산업에 가장 심각한 경제적인 손실을 끼치고 있는 질병으로, 조사자료에 의하면 미국의 경우 년간 손실 금액이 약 6천5백억(미화 560백만 달러)에 이르는 것으로 추정된다. 최근 우리나라도 피해의 정도가 정확히 조사 된 바가 없으나 현장의 골칫거리로 아직도 인식되어 다양한 시도 (Depop, Multi-site, Stabilization, etc)를 통해 사안별로 조치들을 하지만 발생정도는 줄어들지 않고 있다. 따라서 최근 차단방역에 대한 미국의 자료를 소개하오니 양돈현장 수의사들에게 도움이 되었으면 한다.

• Journal of Veterinary Science
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• 제21권6호
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• pp.85.1-85.6
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• 2020

A cold-adapted porcine reproductive and respiratory syndrome virus (CA-VR2332) was generated from the modified live virus strain VR2332. CA-VR2332 showed impaired growth when cultured at 37℃ with numerous mutations (^S731^F, ^E819^D, ^G975^E, and ^D1014^N) in the hypervariable region of the NSP2, in which the mutation ^S731^F might play a vital role in viral replication at 30℃. Conserved amino acid sequences of the GP5 protein suggests that CA-VR2332 is a promising candidate for producing an effective vaccine against PRRSV infection. Further studies on replication and immunogenicity in vivo are required to evaluate the properties of CA-VR2332.

• 한국동물위생학회지
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• 제22권4호
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• pp.363-370
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• 1999

돼지 호흡기 생식기증 바이러스(porcine reproductive and respiratory syndrome virus: PRRSV) 감염이 의심되는 농장으로부터 수집된 혈청가검물 646개로부터 MARC-145 cell을 이용하여 PRRSV 분리를 시도한 바 MARC-145 세포단층상에 세포변성효과(cytopathic effects : CPE)를 나타내는 바이러스 36주를 분리하였다. 분리된 36주가 PRRSV인지 여부를 확인하기 위하여 PRRSV를 실험적으로 접종한 혈청을 이용하여 간접형광항체시험과 혈청중화시험을 실시한 결과 36주 모두가 PRRSV로 동정되었다. 혈청학적인 동정법과 더불어 reverse-transcription polymerase chain reaction을 이용하여 PRRSV open reading frame 5(ORF5)의 유전자를 증폭한 결과 선발된 6주 모두에서 80bp의 flanking sequencing를 포함하여 약 680bp의 ORF5의 유전자를 증폭할 수 있었다.

• 대한수의학회지
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• 제39권2호
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• pp.311-317
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• 1999

Pathogenic effects of 29 different porcine reproductive and respiratory syndrome(PRRS) virus isolates were investigated in swine tracheal ring(STR) cultures by examining their effects on the ciliary activity of STR. Inhibition of ciliary movement and destruction of the tracheal epithelium were seen between 72 and 96 hours postinoculation(PI). Virus replication was demonstrated by examining viral infectivity of the supernatants from the STR cultures. PRRS virus antigen in macrophages was detected by a streptavidin-biotin complex(ABC) immunoperoxidase method. Of the 29 PRRS virus isolates, 8 isolates were classified into pathogenic, and the remaining 21 isolates were determined as mildly pathogenic or apathogenic viruses. These results suggest that STR examination may be used as a method for predicting pathogenic variability of PRRS virus isolates.

• 한국동물위생학회지
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• 제43권4호
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• pp.251-256
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• 2020

Two suckling piglets, 4 days and 10 days of age, showed lethargy and dyspnea after birth and mortality had been increased after incoming gilts from breeding farm. At necropsy, the lungs showed diffuse fail to collapse with rubbery consistency, edematous dilatation of interlobular septa, and lobular consolidation with purple red color. Heart was diffuse pale in color and had several irregular linear-shaped macules or patches. Histopathologically, diffuse interstitial pneumonia with the proliferation of type II pneumocytes was present in the lungs of 2 piglets. Alveolar lumens contained necrotic cellular debris derived from neutrophils and macrophages. Multifocal hemorrhage and necrotizing pneumonia with protozoan tachyzoites were observed in the lungs. Severe multifocal to confluent necrotic myocarditis, necrotic encephalitis, and necrotic adrenalitis with intralesional protozoan tachyzoites were observed in piglets. According to immunohistochemical analysis (IHC), Toxoplasma (T.) gondii tachyzoites antigens were confirmed in lung, heart, brain, and adrenal gland. And porcine reproductive and respiratory syndrome virus (PRRSV) antigens were also detected in the cytoplasm of macrophages in lungs using IHC. Based on the gross, histopathologic and immunohistochemical features, two suckling piglets were diagnosed as co-infection of T. gondii and PRRSV.

• 대한수의학회지
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• 제43권3호
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• pp.463-469
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• 2003

Eight nursery to grower pigs exhibiting weight loss and sudden death were diagnosed as postweaning multisystemic wasting syndrome (PMWS) based on the results of gross findings, histopathology, immunohistochemistry, fluorescent antibody test, virus isolation, PCR, serology, and electron microscopy. Groosly, the pigs had a rough hair coats and were severely emaciated. And moot lymph nodes were pale and enlarged. Lungs were not fully collapsed and exhibited 10 to 40% pale red cranioventral consolidation. Histopathologically, typical lymphohistiocytic interstitial to bronchointerstitial pneumonia, chronic lymphadenitis, severe lymphoid depletion, and basophilic intracytoplasmic inclusions were noted in the most lymphoid tissues. Porcine circovirus panicles were observed in the inguinal lymph node of the pigs by electron microscopy. Porcine circovirus type 2 (PCV2) antigens or viral DNAs were detected in the lesions of all pigs using immunohistochemistry or PCR. Two PCV2 were isolated from a homogenate of pooled lung and lymph node in 2 of the 5 pigs. Additionally, antigens of porcine reproductive and respiratory syndrome virus (PRRSV) and Hemophilus (H.) parasuis were also detected by immunofluorescent antibody test. Serologically, 55% of randomly selected sows and fattening pigs was serum antibody positive to PCV2 by an indirect fluorescent antibody (IFA) test and approximately 18 % of animals in the herd were serologically pooitive by the ELISA kit for PRRSV. To our knowledge, this is the first report of PMWS co-infected with PCV-2, PRRS, and H. parasuis in Korea.

• 한국동물위생학회지
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• 제30권2호
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• pp.197-203
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• 2007

A total of 501 serum samples were selected from blood samples that were submitted to Department of Veterinary Pathology, Kangwon National University from all provinces in Korea from September 2001 to August 2002. Their sera were examined for antibodies to swine influenza virus subtype H1N1 (SlV H1N1) and porcine repro-ductive and respiratory syndrome virus (PRRSV) according to the age of pig, season, and herd size using enzyme-linked immunosorbent assay. The seroprevalence of SIV H1N1, PRRSV, and dual infection were 39.12%, 61.48%, and 25.95%, respectively. The seroprevalence of SIV H1N1 according to herd size was not significant differences (p>0.05). The results showed that the PRRSV infection spread widely in swine herds throughout the country.

• 대한수의학회지
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• 제37권4호
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• pp.793-807
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• 1997

We tried to develop detection system of porcine reproductive and respiratory syndrome virus(PRRSV) by in situ hybridization(ISH) in the piglets experimentally infected with KPRRS-2, the Korean isolate(12 piglets) or Mn-1b, the American isolate(4 piglets), and in the natural infection suspected 6 piglets. Twelve 30-days-old piglets(two pigs per each inoculated group) were inoculated by nasal instillation of KPRRS-2 virus(total dose $10^{4.5}TCID_{50}$), Six piglets(one pig per each group) were induced contact infection with inoculated piglets, during the experiment, and two piglets were used as control. Inoculated or contacted piglets were euthanized at 1, 3, 5, 7, 14 and 21 days postinoculation(DPI). The respiratory signs such as coughing and nasal discharge were observed on day 3 DPI, and ear cyanosis were on day 5 DPI, including contacted piglets. Through the necropsy, purple discolorization of dorsal part of lung, and hypertrophy of local lymph nodes were observed. The histopathological lesions of lung were interstitial pneumonia characterized by type 2 pneumocyte hyperplasia. We prepared the probe for ISH by RNA isolation from KPRRS-2, RT-PCR, and biotin labeling. We performed the ISH within only 1~2 hours using $Microprobe^{TM}$ capillary action system. As the results, the strong red specific positive signals, means PRRSV distribution, was mainly observed in the cytoplasm of alveolar macrophages. And also signals were detected in some type 2 pneumocytes and bronchiolar epithelium of lung, myocardium, liver, kidney, tonsil, spleen, gastrointestinal mucosa, testis and lymph nodes.