• Journal of Veterinary Clinics
• /
• v.30 no.4
• /
• pp.236-240
• /
• 2013

A total of 170 litters (575 samples) of aborted and stillbirth fetuses submitted to the Gyeongsangbuk-Do Veterinary Service Laboratory (GVSL) between January 2006 and December 2010 from pig farms in Gyeongbuk province were studied to identify porcine abortion- and stillbirth-associated viruses such as Porcine parvovirus (PPV), Encephalomyocarditis Virus (EMCV), Japanese Encephalitis Virus (JEV), Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), and Aujeszky's Disease Virus (ADV). Virus was not detected by PCR in 36 litters, but viral antibody was detected by HI and ELISA in 93 litters. The majority of etiological viruses were PPV (67 litters, 39.4%), EMCV (50 litters, 29.4%), PRRSV (15 litters, 8.8%), and JEV (11 litters, 6.5%); ADV was not detected by either PCR or ELISA. Single infection occurred in 52 litters (30.6%), co-infection occurred in 41 litters (24.1%), and unknown cases with no detection of any of the five viruses occurred in 77 litters (45.3%).

• Korean Journal of Veterinary Service
• /
• v.34 no.4
• /
• pp.313-320
• /
• 2011

The purpose of this study was to investigate association with gross lesions and causative pathogens of porcine respiratory disease complex (PRDC) including porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), Mycoplasma hyopneumoniae (MH), Pasteurella multocida (PM), Actinobacillus pleuropneumoniae (APP), Haemophilus parasuis (HP) in slaughtered pigs. A total of 1,200 lung samples were collected randomly from slaughtered pigs in Korea during August of 2010 through July of 2011. The gross lesions were classified according to the six stages (0, 1~10, 11~20, 21~30, 31~40 and ${\geq}41$, unit=%) and 48 samples from each stage were selected to detect viral and bacterial pathogens. The results according to the six stages were 100 (8.3%), 259 (21.6%), 326 (27.2%), 213 (17.8%), 144 (12.0%) and 158 (13.2%) cases, respectively. Prevalence of pneumonia according to season was 87.0~96.7% and the highest prevalence was in spring. In detection of pathogens by PCR, 53 samples were not detected any causative pathogens of PRDC. PCV2, PRRSV, SIV, MH, PM, APP serotype 2, APP serotype 5 and HP were positive in 45.5%, 12.5%, 10.4%, 60.1%, 1.7%, 13.9%, 12.2% and 15.6%, respectively. In co-infection, PCV2-MH was the most detected causative pathogens of PRDC. The detection rate of PCV2 and PRRSV was the highest in spring, of SIV, MH and HP was in winter. The detection rate of APP-2 and APP-5 had no seasonal prevalence. The more severe gross lesions increased, the higher the detection rate showed.

• Korean Journal of Veterinary Service
• /
• v.43 no.4
• /
• pp.227-236
• /
• 2020

In this study, we have developed 3D8 scFv transgenic pig (TG) by microinjection of fertilized one-cell pig zygotes (2.17%). The effect of 3D8 scFv TG on porcine reproductive and respiratory syndrome virus (PRRSV) resistance were evaluated through PRRSV VR2332 (1×103 TCID50/mL) challenge and transmission experiments. As a result, the average daily weight gain (ADWG) of TG increased compared to the wild type pigs (WT) in PRRSV challenge groups and the serum viremia levels of the TG was significantly lower than of WT on the 7 day and 21 day after infection, meaning that the viral shedding was suppressed by 3D8 scFv expression. These results suggest that the expression of 3D8 scFv in pig could suppress spreading of infected virus to pigs sharing a room.

• Journal of the korean veterinary medical association
• /
• v.46 no.3
• /
• pp.279-287
• /
• 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.

• Korean Journal of Veterinary Service
• /
• v.43 no.3
• /
• pp.155-159
• /
• 2020

This study was conducted to investigate the infection of livestock diseases using 500 blood samples from wild boars captured in six cities and one county in northern Gyeonggi province, South Korea. We examined 239 cases of classical swine fever virus (CSFV), and each of 500 cases of foot and mouth disease virus (FMDV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), Mycoplasma hyopneumoniae (MH), Actinobacillus pleuropneumoniae (APP), Pasteurella multocida type A (PMA), Hemophilus parasuis (HP), Salmonella (Sal.) spp. infections. Antibodies were detected against CSFV (23.4%), PRRSV (4.0%), PCV2 (60.4%), MH (3.0%), APP (69.2%), PMA (52.8%), HP (11.8%), and Sal. spp. infections (37.2%). No antibodies were detected against FMDV. As a result of antigenic analysis of 68 positive cases (13.6%) out of 500 PRRS antigen tests, 61 North American cases, 6 European cases, 1 North American-European complex case. PCV2 has 158 positive cases (31.6%) out of 500 antigen tests, and the results indicate that a considerable number of individuals are infected. To our knowledge, this is the first seroprevalence report of MH, APP, PMA, HP, and Sal. spp. infections in wild boars in South Korea.

• Journal of Veterinary Clinics
• /
• v.25 no.3
• /
• pp.139-145
• /
• 2008

To investigate the genotypic diversity of the porcine reproductive and respiratory syndrome viruses (PRRSV) in Korea, we examined 92 clinical samples from three provinces by RT-PCR and a nested PCR, and the complete open-reading frame 7 (ORF 7) sequences of 15 samples selected from 72 PCR-positive specimens were analyzed. When we compared nucleotide (amino acid) sequences of 80 isolates from Korea and overseas countries, the sequences of 7 samples belonged to North American (NA)-genotype, and those of 8 samples, to European (EU)-genotype. The nucleotide (amino acid) identities between two genotypes were 63.7% (59.8%) to 65.1% (63.1%). When compared with NA prototype VR-2332, the 7 strains of NA-genotype shared 89.8% (93.6%) to 91.2% (96.0%) identity of nucleotide (amino acid) sequence. The 8 strains of EU-type shared 93.6% (92.3%) to 94.3% (93.8%) identity of nucleotide (amino acid) sequence as compared to EU prototype Lelystad. In phylogenetic tree analysis by neighbor-joining method, all of the 8 EU-type strains were clustered into group 4 distinct from ED-prototype Lelystad (group 1). In NA-genotype, 24 domestic isolates reported previously and the 7 strains of NA-type determined in this study were clustered into group 1, while US prototype VR 2332 was classified into different group (group 2). These results suggest that emergence of EU-genotype and the dual-infection of NA- and EU-genotypes may be prevalent in the pig farms in Korea. The high degree of genetic diversity of field PRRSVs should be taken into consideration for control and preventive measures.

• Korean Journal of Veterinary Research
• /
• v.37 no.4
• /
• pp.793-807
• /
• 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.

• Korean Journal of Veterinary Research
• /
• v.43 no.3
• /
• pp.463-469
• /
• 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.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.54 no.1
• /
• pp.63-72
• /
• 2012

In livestock industry, damage caused by the epidemic diseases such as Foot-and-Mouth Disease (FMD), Highly-Pathogenic-Avian-Influenza (HPAI) and Porcine-Reproductive-and-Respiratory-Syndrome (PRRS) was very serious. The financial loss incurred from FMD alone which occurred on Nov. 2011 in Korea was estimated at 3 billion won, 23 % of annual livestock industry production. The livestock industry in Korea has greater risk of disease infection because of high density production, etc. Investigating the spread of livestock diseases should consider both direct and indirect contact as well as other various factors including airborne. Airborne infection of livestock disease was first hypothesised in the early 1900s, however, field experimental studies are still limited. Furthermore, no protocol is available in detecting airborne viruses in the field. In this study, effective virus samplers were investigated by comparative analysis of the type of samplers used detect to airborne virus. Laboratory experiments were conducted to compare virus samplers such as Bio-sampler, Dust-sampler, Compact-Cascade-Impactor (CCI) and Microflow in detecting PRRSV. Samples were analyzed by Reverse-Transcription PCR to assess the efficiency of the instrument in detecting the airborne virus. First, samples were classified into five levels according to light intensity of gel images and then the classified results were normalized. In every case, Bio-sampler and Dust-sampler were comparable with each other and have shown to be more effective than CCI and Microflow samplers.

• Korean Journal of Veterinary Service
• /
• v.39 no.4
• /
• pp.231-237
• /
• 2016

The present study was conducted to investigate the lesion of red internal organs in slaughtered pigs and provided assistant data for pig farms. During March to December 2015, a total of 1,160 lung samples out of 58 herds were collected randomly from pigs slaughtered in Jeonbuk province. In addition, 290 hilar lymph nodes from pig with pneumonic lung lesion (5 samples per herd) were screened for selected viral and bacterial pathogens. Gross lesions of lungs such as swine enzootic pneumonia (SEP), pleuritis, pleuropneumonia, pericarditis and liver white spots were examined. The overall prevalence of SEP was 64.3% (746/1,160). In the analysis of seasonal prevalence, there was an increase of occurrence during the spring months (287/400, 71.8%) and decrease during the fall months (93/200, 46.5%) among the whole herds. The mean number of SEP score per pig was $1.20{\pm}1.28$. The prevalence of pleuropneumonia, pleuritis, pericarditis, and milk spot was 25.5% (296/1,160), 44.1% (512/1,160), 3.8% (44/1,160) and 17.6% (204/1,160), respectively. The most frequent region with lung lesion was diaphragmatic lobes (left 17.1%, right 17.3%). In the detection of viral pathogens by PCR, porcine circovirus type2 (PCV2) was positive in 86.9% (252/290), while porcine reproductive and respiratory syndrome virus (PRRSV) was not detected, In the case of bacterial pathogens, 50 microorganisms were isolated by PCR and/or microbiological test. The most frequently isolated bacteria was Streptococcus suis (20, 34.4%), followed by Pasteurella multocida (17, 29.3%), Streptococcus spp. (11, 3.4%), Actinobacillus pleuropneumoniae (2, 8.9%).