다양한 PRRSV 감염상태에 있는 돼지 혈청을 이용한 PRRS 항체 ELISA 키트들의 비교 평가

서병주 ( Byoung Joo Seo ),김현일 ( Hyoun Il Kim ),김원일 ( Won Il Kim ) 한국동물위생학회 2014 韓國家畜衛生學會誌 Vol.37 No.3

Porcine reproductive and respiratory syndrome virus (PRRSV) causes major economic losses to the Korean pig industry. ELISA tests using recombinant nucleocapsid protein of PRRSV have been most commonly used for PRRS diagnostics. In the current study, two commercial PRRSV ELISA kits (Bionote PRRSV Antibody ELISA and IDEXX 3XR PRRS Antibody ELISA) have been compared using sera collected from 19 swine farms in various stages of PRRSV infection confirmed by professional diagnostic centers. Thus 130 sera collected from 5 different farms with active PRRSV infection, 130 sera from 6 different farms with PRRS-stabilized status, and 140 sera from 8 different farms with PRRS-free status were evaluated to determine the correlation of test results between those ELISA kits. Both ELISA kits showed a good correlation [PRRSV-positive farms (R2=0.6375) and stabilized farms (R2=0.8928)] in sample-to-positive (S/P) ratio values. Among the 140 sera from negative farms, one sample was falsely positive by either of the ELISA kits. In conclusion, both of the ELISA kits showed a good correlation when applied on field samples collected from farms at various stages of PRRSV infection. Bionote ELISA or IDEXX ELISA gave a false positive result on 1 out of 140 negative samples so their specificity was calculated as 99.3%. Therefore, Bionote ELISA would be a good complementary and alternative method for IDEXX ELISA kit, and vice versa.

국내 분리 돼지 부종병 대장균의 병원성 유전자 및 시가독소 생성 검증

서병주 ( Byoung Joo Seo ),정창기 ( Chang Gi Jeong ),강아름 ( A Rum Kang ),조호성 ( Ho Seong Cho ),김원일 ( Won Il Kim ) 한국가축위생학회 2016 韓國家畜衛生學會誌 Vol.39 No.2

Porcine edema disease (ED) is a communicable disease of pigs caused by infection with Shiga toxin (Stx)-producing Escherichia coli (STEC) which expresses F18 fimbriae and/or Stx type 2e (Stx2e). While STEC causes a severe illness including hemorrhagic colitis and hemolytic-uremic syndrome in humans, it induces damage to the vascular endothelium, which results in edema, hemorrhage, and microthrombosis, leading in high mortality in pigs. In the present study, we cultured Stx2e-producing E. coli field isolates from conventional pig farms that experienced sudden deaths previously with symptoms similar to porcine edema disease, which were further investigated with Shiga toxin profiles. A total of 43 strains were identified from the collected samples by F18 or Stx2e specific PCR. Based on the PCR, 42 isolates out of 43 isolates were proved to carry one of F18 or Stx2e genes and 14 isolates to carry both F18 and Stx2e genes. All of the 30 isolates that harbored Stx2e gene induced the cytopathic effect (CPE) in vero cells and especially, the isolate 150229 produced the highest level of Shiga toxin. Therefore, we identified the virulence genes (F18 and Stx2e) and demonstrated Shiga toxin-producing abilities from porcine edema disease causing E. coli filed isolates. These results suggested that one of the isolates could be a vaccine antigen candidate against STEC through further investigating to elicit an immune response.

김치에서 분리한 Lactobacillus sakei proBio65의 면역 조절 특성

임정희 ( Jeong Heui Lim ),서병주 ( Byoung Joo Seo ),김정은 ( Jung Eun Kim ),채창석 ( Chang Suk Chae ),임신혁 ( Sin Hyeog Im ),한윤수 ( Youn Soo Hahn ),박용하 ( Yong Ha Park ) 한국미생물생명공학회(구 한국산업미생물학회) 2011 한국미생물·생명공학회지 Vol.39 No.3

김치로부터 새로운 프로바이오틱균주인 Lactobacillus sakei proBio65를 분리하고 명명하였다. 형질전환 생쥐 (Foxp3-GFP KI 생쥐)를 이용하여 L. sakei proBio65의 면역조절 메커니즘 규명 및 면역 조절능을 확인하고 in vivo 적용 질환제어 응용 가능성을 평가하였다. 조절 T 세포의 master 전사조절인자로 알려진 Foxp3+를 선정하고, L. sakei가 Foxp3+전사조절인자를 증가시키는지 확인하기 위해 확립된 세포기반 screening system을 이용하였다. 항 염증성 사이토카인 전사조질인자의 증가에 이어 Foxp3+ 전자조절 인자발현의 상당한 증가를 확인하였다. L. sakei proBio65는 염증성면역 장애의 조절에 치료적으로 유용할 것이다. We isolated and identified a novel probiotic strain, Lactobacillus sakei proBio65 from Kimchi. To determine whether L. sakei proBio65 has an immunomodulatory effect, we investigated cells via an in vitro screening system which co-cultured freshly isolated mesenteric lymphocyte with probiotics. A significant increase of Foxp3+ transcription regulatory factor expression was observed, followed by an increase in anti-inflammatory cytokines transcription regulatory factor. L. sakei proBio65 exhibited high levels of the IL-10/IL-12 production ratio and enhanced Foxp3 expression in vitro. L. sakei proBio65 may thus be therapeutically useful for the modulation of inflammatory immune disorders.

하절기 급사 돼지의 Clostridium novyi 진단 및 분리

정창기 ( Chang Gi Jeong ),서병주 ( Byoung Joo Seo ),김원일 ( Won Il Kim ) 한국가축위생학회 2016 韓國家畜衛生學會誌 Vol.39 No.2

Clostridium novyi (C. novyi) is a gram positive, non-capsulated, motile, obligatory anaerobe that produces endospores. Both C. novyi type A and B produce a bacteriophage encoded lethal alpha toxin which belongs to a family of large clostridial cytotoxins. These large clostridial cytotoxins of C. novyi bind to the uncharacterized receptors on host vascular endothelial cells, which leads to the loss of integrity of the vascular endothelium with subsequent edema, refractory hypotension, organ failure, and sudden death. A total of 13 sudden death cases were submitted to Chonbuk National University- Veterinary Diagnostic Center between June and October, 2015. The samples, mainly liver, were collected in sterile vials after necropsy and processed within 12∼24 hours for diagnosis, isolation and identification of C. novyi. All of the 4 gram positive samples showed amplification by PCR. Out of 4 positive samples, 3 were detected to be C. novyi type B and 1 was detected as C. novyi type A. Based on the 16S rDNA sequence analysis, 1 case (150564) showed 99% similarity with C. novyi type A while other 3 cases (150388, 150557 and 150775) presented 99% similarity with C. novyi type B. Based on the results, C. novyi was found to be prevalent in Korean pig farms and causes sudden death to finishing pigs or sows during summer season. Thus, C. novyi should be considered for differential diagnosis on sudden death cases during the summer season.

Serratia marcescens 검출을 위한 PCR 기법 개발 및 돼지정액 유래균주에 대한 항생제 감수성 양상

정지아(Ji-A Jung),김애란(Aeran Kim),서병주(Byoung Joo Seo),정석찬(Suk Chan Jung),김인철(In Cheul Kim),정기화(Ki Hwa Chung),정병열(Byeong Yeal Jung) 한국생명과학회 2013 생명과학회지 Vol.23 No.9

돼지 원정액의 채취나 희석정액의 제조과정 중 세균오염이 많이 발생하는데, 이는 정자활력의 감소뿐 아니라 모돈의 수태율 저하 등을 유발한다. 특히 Serratia marcescens는 환경에 널리 존재하며 비위생적으로 제조된 정액에 많이 분리되고 있다. 본 연구에서는 S. marcescens의 신속한 동정을 위하여 PCR 기법을 개발하였으며, 국내 돼지정 액 유래 S. marcescens을 이용하여 최소생육억제농도(MIC) 등을 조사하고 유효 항생제를 선발하고자 하였다. 개발 PCR 기법은 S. marcescens에서만 306 bp의 특이 유전자 증폭산물을 형성하였으며, 기타 돼지정액에서 분리 보고된 균주나 Serratia 속균에서는 유전자 증폭 산물이 형성되지 않아 특이성이 인정되었다. PCR 기법의 민감도는 S. marcescens에서 추출된 DNA 50 pg/μl까지 검출이 가능하였다. 디스크확산법에 의한 국내 돼지정액 유래 S. marcescens의 항생제 감수성을 조사한 결과, gentamicin, ceftiofur, neomycin 등에서 80% 이상의 높은 감수성을 보였 다. 한편 ceftiofur, enrofloxacin, gentamicin, neomycin의 MIC90는 각각 8, 8, 8, 16 μg/ml로 나타났다. 따라서 개발된 PCR 기법은 S. marcescens를 동정하는 유용한 방법이며, gentamicin 등 선발된 항생제는 S. marcescens에 의한 정액 내 세균오염을 관리하기 위한 희석제용 항생제로 추천된다. During the collection of boar semen, bacterial contamination usually occurs. The contamination has deleterious effects both on semen quality and on sow fertility. The majority of contaminants are gram-negative bacteria, especially Serratia marcescens. In this study, we developed a PCR assay for the identification of S. marcescens targeting the luxS gene (GenBank no. EF164926). S. marcescens yielded a specific 306 bp PCR product. However, no amplification was observed in the other strains tested. The detection limit of PCR was 50 pg/μl of template DNA of S. marcescens. The antimicrobial susceptibility patterns of S. marcescens isolated from boar semen were tested using the disk diffusion method. Gentamicin, ceftiofur, florfenicol, and neomycin showed high sensitivity in this test. The minimum inhibitory concentration (MIC) was also determined by the broth microdilution method. The MIC90 values of ceftiofur, enrofloxacin, gentamicin, and neomycin were 8, 8, 8, and 16 μg/ml, respectively. These results indicate that PCR amplification of the luxS gene is a reliable and effective method for the identification of S. marcescens and that ceftiofur, enrofloxacin, gentamicin, and neomycin are effective semen extenders for controlling S. marcescens.