• 한국동물위생학회지
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• 제22권3호
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• pp.247-255
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• 1999

Sequential morphologic changes in the lymphoid organs were examined after ocular and cloacal inoculation in 3weekold chicks with a highly virulent strain (SH/92) of infectious bursal disease virus (IBDV). The infected chickens were sacrificed at 6, 12, 24, 48, 72, and 96 hrs post inoculation (Pl), and thymus, harderian gland, ceacal tonsil, and spleen were observed. Histologically, the significant lesions were characterized by lymphocyte depletion and the earliest detectable changes were evident at 12 hrs Pl. In thymic cortex, lymphoid depletion with apoptosis and prominent "tingible body macrophages" were observed. As the infection advanced, the lesions showed more severe changes. Dying cells were characterized either by capping of nuclear chromatin (apoptosis) or by cytoplasmic swelling (necrosis). In situ staining for apoptosis, some lymphoid cells revealed typical positive reaction, even the stainability was variable depend on every lymphoid organs. These results suggest that IBBV (SH/92) cause severe damage both primary and secondary lymphoid organs, and both T and B lymphocytes. Also the lymphoid depletion of these organs is caused by necrosis and apoptosis induced by IBDV.d by IBDV.

• 대한수의학회지
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• 제39권3호
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• pp.545-553
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• 1999

A 474-base pair segment covering the hypervariable region of VP2 gene from six Korean infectious bursal disease virus(K-IBDV) isolates(K1, K2, SH/92, 225, 269, 310) and one attenuated IBDV(DAE) were amplified using RT-PCR, sequenced, and compared with published sequences for IBDV. K-IBDV isolates(K1, K2, SH/92, 225, 269) and foreign very virulent(vv) IBDV strains had 94.93~100% amino acid sequence similarity. K-IBDV isolate 310 and other K-IBDV isolates had 84.31~86.07% amino acid sequence similarity. Attenuated strain(DAE), like other attenuated strain, has substitution at positions 279(D to N) and 284(A to T) as well as in the serine-rich heptapeptide region. Five K-IBDV isolates except 310 isolate share unique amino acid residues at positions 222(A), 256(I), 294(I) which are not present in other standard and attenuated strains. At the two hydrophilic region, K-IBDV isolates except 310 isolate had identical amino acids comparing with Belgium vv IBDV 894VB but had four amino acid substitutions comparing with Chinese vv IBDV F9502. The SWSASGS heptapeptide is conserved in all K-IBDV isolates. The sequence of K-IBDV isolate 310 was markedly different from other IBDV strains, evolving from a separate lineage than the others. By phylogenetic analysis, Five K-IBDV isolates except 310 isolate were categorized in one group with foreign vv IBDV isolates but K-IBDV isolate 310 was categorized in a separate group which was differentiated from other compared IBDV strains.

• 대한수의학회지
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• 제51권1호
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• pp.37-46
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• 2011

Infectious bursal disease virus (IBDV) is a member of the Avibirnavirus genus of the Birnaviridae family which genome consists of two segments (A and B) of double stranded RNA. Segment A gene of KNU08010 isolate, which was isolated from a 15-day-old chicken flock in 2008, was sequenced and compared with other IBDV isolates including SH/92 strain, the first Korean very virulent (vv) IBDV isolate. The amino acid sequences of segment A gene showed that KNU08010 had 99.2% homology with SH92 strain. KNU08010 isolate had specific amino acids A222, I242, I256, I294 and S299 which are highly conserved among vvIBDV strains. Phylogenetic analysis based on the nucleotide sequences of variable region of the VP2 gene of 18 IBDV strains revealed that KNU08010 was grouped with vvIBDVs and was closely related to Korean vvIBDVs isolated from wild birds.

• 한국수의병리학회지
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• 제2권1호
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• pp.1-8
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• 1998

Chickens at 3-weeks of age were inoculated with a highly virulent strain (SH/92) of Infectious Bursal Disease Virus(IBDV) through ocular and cloacal routes. The infected chickens were killed at 6, 12, 24, 48, 72, and 96 hrs post inoculation (PI) and Bursa of Fabricius(BF) were collected. The sizes of bursal follicules in infected chickens decreased at 48 to 96 hrs PI. Histologically the cellular changes were first evident at 12 hrs PI and characterized by condensation of nuclear chromatin of bursal lymphocytes indicating apoptosis. By 24 hrs PI apoptotic lymphocytes dramatically increased. In addition infiltration of heterophils were also seen in the follicles and in the interfollicular connective tissues. At 48 hrs PI, cystic cavities were observed in the follicles. As the infection advanced the bursal follicles showed atrophy accompanied by disappearance of heterophils and reduction in number of lymphocytes in the cystic cavities which was replaced by proteineous materials. The nuclei of most affected lymphocyte stained positively with the in situ end labeling for apoptosis. Electron microscopy showed viral particles with crystalline array in the lymphocytes of BF infected with IBOV. These results indicated that SH/92 IBDV infection in chickens caused increased apoptosis in the BF.

• 대한수의학회지
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• 제41권3호
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• pp.333-342
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• 2001

To detect the genetic variations among infectious bursal disease (IBD) vaccine strains, the hypervariable region of VP2 gene of seven IBDV vaccine strains were amplified using reverse transcriptase/polymerase chain reation(RT/PCR). Ampllified PCR products of IBDV were cloned, sequenced, and compared with published sequences for IBDV. Vaccine strains (JOONG, HAN, B7, IB, BU2, G2, CIL) used in Korea and Korean field isolates (SH/92, K1, 310) had 81%(310 and HAN) ~ 98%(SH/92 and CIL) amino acid sequence similarity. Vaccine strains had 80%(HAN and IB) ~ 99%(JOONG and BU2) amino acid sequence similartiy. Intermediate plus vaccine strain, CIL was not substituted at positions 279(D $\rightarrow$ N) and 284(A $\rightarrow$ T), and conserved in serine-rich heptapeptide. At the two hydrophilic region, JOONG, IB and Bu2 strains had identical amino acid sequence comparing with STC strain. By phylogenetic analysis, JOONG and DAE strains were categorized in same group with BU2. The CIL and STC strains closely related but seperated from G2, HAN, B7 and IB strains.

• 대한수의학회지
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• 제46권3호
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• pp.235-248
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• 2006

The VP2 full gene of Korean infectious bursal disease virus(IBDV) strain, SH/92, three attenuated vaccine strains, Bur706, Bursine-2 and CEV/AC strains, were amplified by reverse transcriptase-polymerase chain reaction and sequenced and compared with published VP2 gene sequences of IBDVs. The VP2 nucleotide sequence similarity between SH/92 and three vaccine stains was 95.6~96.5% whereas the nucleic acid similarity among three vaccine strains was 97.5~98.5%. The amino acid sequence similarity of VP2 of SH/92 compared with three vaccine strains was between 94.4 and 97.6% while the amino acid similarity among three vaccine strains was between 97.4 and 98.4%. The amino acid similarity between SH/92 and classical virulent strain, 52/70 and STC strain was 96.4 and 96.5%, respectively. The serine-rich heptapeptide was conserved in CEVAC and Bursine-2 as well as SH/92 but not in Bur706. The phylogenetic tree developed from amino acid sequences showed that SH/92 was categorized with vv IBDVs(HK46, OKYM, KKI, UPM94/273, SH95) in one branch while three vaccine strains were catagorized with STC strain in the other branch.

• 한국가축위생학회:학술대회논문집
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• 한국가축위생학회 1999년도 제22차 학술대회
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• pp.174-174
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• 1999

• 미생물학회지
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• 제45권2호
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• pp.91-98
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• 2009

닭의 전염성 F낭병 바이러스(IBDV)가 원인 바이러스인 전염성 F낭병은 전 세계 양계산업에 경제적으로 피해가 큰 중요한 질병이다. 이 연구의 목적은 닭에서 IBDV에 대한 방어면역을 유도하기 위한 in ovo 초회항원자극(priming)과 불활화백신에 의한 보강접종 방법에 항원보강제(adjuvant)로 chicken interleukin 6 (pcDNA-ChIL-6;plasmid encoding chicken interleukin-6)와 levamisole (LMS)의 효과를 조사하는 것이다. IBDV의 VP2, VP, VP3 protein을 암호화하는 유전자백신인 plasmid DNA vaccine (pcDNA-VP243) 단독 또는 pcDNA-ChIL-6 또는 LMS와 함께 18일령 부화란의 양막낭(amniotic sac)에 접종하고 부화한 1주령의 병아리에 불활화 IBD 백신을 근육 접종한 다음 3주령에 고병원성 IBDV인 SH/92 주로 공격 접종하고 10일 동안 관찰하였다. 백신하지 않은 공격접종 대조군이 100%의 폐사율을 보인 반면 pcDNA-VP243 단독 접종군과 pcDNA-VP243에 pcDNA-ChIL-6 또는 LMS를 첨가한 실험군은 모두 100%의 생존율을 나타내었다. 그러나 공격접종 후 F낭의 손상을 평가하기 위한 IBDV RNA의 검출, B/B ratio와 F낭의 병변지수(lesion score) 등을 분석한 결과 pcDNA-VP243에 pcDNA-ChIL-6 또는 LMS를 첨가한 실험군은 pcDNA-VP243 단독 접종군보다 향상된 방어효과를 나타내지 않았다. 이 실험결과는 유전자백신에 의한 in ovo 초회항원자극-불활화백신에 의한 보강접종법이 고병원성 IBDV로부터 닭을 보호하기 위한 효과적인 방법이었으나 pcDNA-ChIL-6 또는 LMS의 첨가로 인한 방어효과의 향상은 나타나지 않았다.