• 대한수의학회지
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• 제38권4호
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• pp.777-783
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• 1998

Antigenic types of 114 Salmonella pullorum and 152 Salmonella gallinarum field isolates were evaluated. All 3 antigenic types were identified among field isolates of S pullorum by factor-serum analysis but the majority of them were standard type(90.4%). Of the 114 S pullorum isolates, only eight(7.0%) were intermediate type and 3(2.6%) were variant type. Using the ammonium sulfate precipitation(ASP) test, one-hundred and three(90.4%) S pullorum isolates were standard type, while intermediate and variant types were 8.4% and 1.4%, respectively. One-hundred and fifty-two S gallinarum isolates were identified as standard type by ASP test and serological analysis. According to the random amplified polymorphisms of DNA(RAPD) patterns, most of S pullorum isolates were differentiated with 3 types in their fragment-patterns. No correlations were found between SDS-PAGE profiles and antigenic types of S pullorum isolates.

• Journal of Veterinary Science
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• 제21권6호
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• pp.76.1-76.13
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• 2020

Background: The predominant infectious bronchitis virus (IBV) strains detected in chickens in Malaysia are the Malaysian variant (MV) and QX-like, which are associated with respiratory distress, nephropathy, and high mortality. On the other hand, the antigenic relatedness and efficacy of IBV vaccines against these 2 field IBV strains are not well characterized. Objectives: This study aimed to determine the antigen relatedness and efficacy of different IB vaccine strains against a challenge with MV and QX-like strains. Methods: The antigen relatedness and the ability of different IB vaccine strains in conferring protection against MV and QX-like were assessed based on the clinical signs, macroscopic lesions, and ciliary activity. Results: The MV strain IBS037A/2014 showed minor antigenic subtype differences with the vaccine virus Mass H120 and 4/91 strains but showed major antigenic subtype differences with the K2 strain. The Malaysian QX-like strain IBS130/2015 showed major antigenic subtype differences with the MV strain IBS037A/2014 and the vaccine strains except for K2. Chickens vaccinated once with Mass (H120) or with non-Mass (4/91 and K2) developed antibody responses with the highest antibody titer detected in the groups vaccinated with H120 and 4/91. The mean ciliary activities of the vaccinated chickens were between 56 to 59% and 48 to 52% in chickens challenged with IBS037A/2014 and IBS130/2015, respectively. The vaccinated and challenged birds showed mild to severe lesions in the lungs and kidneys. Conclusions: Despite the minor antigenic subtype differences, a single inoculation with Mass or non-Mass vaccines could not protect against the MV IBS037A/2014 and QX-like IBS130/2015.

• IMMUNE NETWORK
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• 제16권5호
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• pp.261-270
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• 2016

The human immune system has evolved to fight against foreign pathogens. It plays a central role in the body's defense mechanism. However, the immune memory geared to fight off a previously recognized pathogen, tends to remember an original form of the pathogen when a variant form subsequently invades. This has been termed 'original antigenic sin'. This adverse immunological effect can alter vaccine effectiveness and sometimes cause enhanced pathogenicity or additional inflammatory responses, according to the type of pathogen and the circumstances of infection. Here we aim to give a simplified conceptual understanding of virus infection and original antigenic sin by comparing and contrasting the two examples of recurring infections such as influenza and dengue viruses in humans.

• 대한수의학회지
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• 제49권3호
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• pp.207-213
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• 2009

Rabbit hemorrhagic disease (RHD) is caused by RHD virus (RHDV) and is one of the most fatal diseases of rabbits. Acute death of rabbits occurred in a farm located in the Gyeonggi province of South Korea. The virus was isolated and confirmed as RHDV based on reverse transcription polymerase chain reaction and hemagglutination assay (HA), and the isolate was designated as KV0801. The nucleotide sequence of the complete VP60 gene of KV0801 was determined and the corresponding amino acid sequence was deduced. Molecular analysis showed that the KV0801 isolate can be classified as a pandemic antigenic variant strain, RHDVa. The VP60 nucleotide sequence and deduced amino acid homology between KV0801 and other Korean isolate, RHF89, which was isolated in 1988, were 92.1 and 94.3%, respectively. The pathogenicity of the KV0801 isolate at an HA titer ranging from 16,384 to 0.16 HA units was evaluated in five-month-old SFP rabbits. The rabbits inoculated with KV0801 isolate containing more than 1.63 HA units died within six days of inoculation. These results suggest that a highly pathogenic RHDVa is circulating in the rabbit populations of Korea.

• 한국가금학회지
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• 제50권4호
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• pp.231-240
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• 2023

전염성 F낭병은 닭에서 F낭의 위축 및 염증이 나타나고, 이로 인해 면역억제를 특징으로 하며, 급성, 높은 점염성을 가지는 질병이다. VP2 유전자의 염기서열 분석을 통해 유전형이 분류되고, 유전형에 따라 항원성 및 병원성에 큰 차이를 나타내고 있다. 최근 중국에서 발생한 항원 변이주의 경우, 기존의 미국형 항원 변이주와는 다른 분자 특성을 보이는 것으로 나타났다. 최근 국내에서도 이러한 중국형 항원 변이주가 발생하고 있고, 따라서 본 연구에서는 국내 양계농장에서 분리된 항원 변이주의 유전체 분석을 통한 분자적 특성을 확인하였다. 국내 육계 및 토종닭으로부터 4개의 항원 변이주를 RT-PCR을 통해 확인하였고, chorioallantoic membrane 접종을 통해 분리하였다. VP2 유전자의 hypervariable region의 분석 결과, 4개의 항원 변이주 중 1개는 미국형 항원 변이주로 확인되었고, 이는 2009년 국내에서 보고된 09D243 균주와 유사한 것으로 나타났으며, 3개의 중국형 항원 변이주는 최근 국내 및 중국의 유행주와 유사한 것으로 확인되었다. 우리의 결과에서 국내 양계농장에서 중국형 및 미국형 항원 변이주가 퍼져 있음을 확인하였고, 또한 백신을 접종한 농장에서의 발생도 이뤄지고 있어 항원 변이주에 대한 상용화 백신의 보호 효능에 대한 연구도 필요합니다.

• 대한수의학회지
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• 제6권1호
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• pp.10-17
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• 1966

Salmonella pullorum 표준형균주(標準型菌株) 및 변이형균주(變異型菌株)의 균체물질(菌體物質)을 가열추출(加熱抽出), 산성추출(酸性抽出), 산성가열추출(酸性加熱抽出), trypsin 소화(消化) 급류산(及硫酸) ammonium 포화(飽和)등의 방법(方法)으로 처리(處理)하여 얻은 각(各) 분층(分層)의 항원성(抗原性)을 혈구응집반응(血球凝集反應) 및 침강반응(沈降反應)으로 비교검토(比較檢討)하여 다음과 같은 결과(結果)를 얻었다. 1. S. pullorum 균체항원(菌體抗原)은 표준형균주(標準型菌株) 및 변이형균주(變異型菌株) 다같이 가열추출(加熱抽出)에서만이 인(人)0형혈구(型血球)와 계혈구(鷄血球)에 흡착(吸着)되어 혈구응집반응(血球凝集反應)의 반응(反應)을 나타내였다. 2. Trypsin의 영향(影響)은 별(別)로 저명(著明)하지는 아니하나 산성추출항원(酸性抽出抗原)에서 표준형균주(標準型菌株)보다 변이형균주(變異型菌株)가 혈구응집반응(血球凝集反應)에서 약간(若干) 양성(陽性)으로 변전(變轉)되었다. 3. S. pullorum 표준형균주(標準型菌株)의 항원성물질(抗原性物質)은 유안포화시(硫安飽和時) 거의 그 침전분층(沈澱分層)에 이행(移行)되며 이는 동(同) 침전분층(沈澱分層)을 trypsin 소화(消化)하므로써 혈구응집반응(血球凝集反應)에 강력(强力)한 항원성(抗原性)을 보유(保有)하고 있으므로 증명(證明)할 수 있었다. 4. 유안포화시(硫安飽和時) S. pullorum 변이형균주(變移型菌株)는 산성추출항원(酸性抽出抗原)에서는 침전분층(沈澱分層)을 얻을 수 없었고 그 상청(上淸)에는 항원성(抗原性)도 없었으나 가열추출항원(加熱抽出抗原)에 있어서는 상청(上淸) 급(及) 침전분층(沈澱分層) 공(共)히 혈구응집반응(血球凝集反應)에 양성(陽性)을 나타내었다. 5. 각종추출항원분층(各種抽出抗原分層)의 침강반응(沈降反應)에서는 거의 반응(反應)을 나타내지 아니하였다.

• Journal of Veterinary Science
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• 제23권1호
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• pp.14.1-14.11
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• 2022

Background: Carnivore protoparvovirus 1, also known as canine parvovirus type 2 (CPV-2), is the main pathogen in hemorrhagic gastroenteritis in dogs, with a high mortality rate. Three subtypes (a, b, c) have been described based on VP2 residue 426, where 2a, 2b, and 2c have asparagine, aspartic acid, and glutamic acid, respectively. Objectives: This study examined the presence of CPV-2 variants in the fecal samples of dogs diagnosed with canine parvovirus in Bogotá. Methods: Fecal samples were collected from 54 puppies and young dogs (< 1 year) that tested positive for the CPV through rapid antigen test detection between 2014-2018. Molecular screening was developed for VP1 because primers 555 for VP2 do not amplify, it was necessary to design a primer set for VP2 amplification of 982 nt. All samples that were amplified were sequenced by Sanger. Phylogenetics and structural analysis was carried out, focusing on residue 426. Results: As a result 47 out of 54 samples tested positive for VP1 screening, and 34/47 samples tested positive for VP2 980 primers as subtype 2a (n = 30) or 2b (n = 4); subtype 2c was not detected. All VP2 sequences had the amino acid, T, at 440, and most Colombian sequences showed an S514A substitution, which in the structural modeling is located in an antigenic region, together with the 426 residue. Conclusions: The 2c variant was not detected, and these findings suggest that Colombian strains of CPV-2 might be under an antigenic drift.

• 한국미생물·생명공학회지
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• 제50권1호
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• pp.126-134
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• 2022

Norovirus (NoV) is an important pathogen causing acute gastroenteritis worldwide. The purpose of the present study was the molecular characterization of NoV. A total of 408 stool specimens collected from hospitalized children associated with acute gastroenteritis in Chiang Rai, Thailand, 2015-2017 were investigated for the presence of NoVs by RT-PCR. NoV GII was detected in 32 samples (7.8%). Five distinct genotypes were identified, including GII.4 (13/32, 40.6%), GII.3 (11/32, 34.3%), GII.17 (4/32, 12.5%), GII.2 (2/32, 6.3%), and GII.14 (2/32, 6.3%). NoV infection occurred mostly in young children under 3 years of age (31/32, 96.9%) and showed the main peak in summer months from March to April (18/32, 56.3%). Phylogenetic analysis revealed that all 13 GII.4 strains clustered with GII.4 Sydney 2012 variant. Representative GII.3 strains were analyzed as a recombinant GII.3P[12] strain. Several amino acid differences were found in the antigenic epitopes and antibody binding sites of the VP1 capsid of the GII.3P[12]. Homology modeling of the P domain of the GII.3P[12] strain demonstrated that 10/13 amino acid differences were predicted to be located on the surface-exposed area of the capsid structure. These amino acid changes might affect the infectivity and the antigenicity of the recombinant GII.3P[12]. The prevalence of GII.4 Sydney 2012 and recombinant GII.3P[12] strains indicates the genetic diversity of circulating NoVs in Thailand, emphazing the importance of continuous surveillance to mornitor newly emerging NoV strains in the future.

• 한국동물위생학회지
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• 제38권1호
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• pp.51-56
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• 2015

Infectious bronchitis virus (IBV) causes an acute and highly contagious viral disease of chicken that is great economic losses to the poultry industry worldwide. Among the IBV structural proteins, the high rate spike glycoprotein S1 gene mutation and antigenic variant strains have been reported in many countries. During the years 2012~2014, 10 IBV strains were isolated from infected chicken farms distributed in provinces of Jeonbuk. Analysis of the S1 gene sequences amplified from 10 isolated strains with QX strains showed nucleotide homologies ranging from 96.5 to 95.4%. Phylogenetic analysis revealed that all strains were clustered into QX-like groups. This study suggests that QX-like IBVs are circulating in commercial chicken farms in Jeonbuk. Therefore, the continuing survellance is significantly important for prevention and control of BIV infection.

• 한국가금학회지
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• 제10권1호
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• pp.60-66
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• 1983

Monoclonal antibodies against Taka virus, a variant of Newcastle disease virus (NDV), were produced to compare the antigenicites of several avian paramyxoviruses including NDV. It was also used to study the activesite(s) of haemagglutin (HA) and neuraminidase activities of NDV. Five independent hybrid cell lines, which produced monoclonal antibodies against haemagglutinin-neuraminidase (HN) molecule of Taka virus, were established. From the results of the cross haemagglutination-inhibition(HI) test the monoclonal antibodies, the HN molecule of Taka virus seemed to have at least three different antigenic determinats; one was specific for all NDV strain tested, the second was only for Taka virus and the third was for Take virus, Banger and Yucaipa Furthermore the differences in the ratio of HI to neuraminidase-inhibition titers suggested that the active sites involved in HA and neuraminidase activities might be different from each other. However, since each of five monoclonal anitbodies was not especially specific for either HA or neuraminidase, the possibility that a single active site on the HN molecule may be responsible for both activities has not been excluded.