The clonality of a random sample of 102 invasive pneumococcal serotype 3 strains isolated from Gauteng Province during January 2000 to December 2003 was investigated. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) revealed a heterogeneous population with several PFGE clusters and sequence types (STs). The largest PFGE cluster comprised 36/102 (35%) isolates including seven that belonged to ST458, a clone that is not common in other parts of the world. The global clone (ST180) which is common in the United States and other countries was found in a cluster that represented only 14/102 (14%) of isolates examined. The first multidrug-resistant pneumococcal serotype 19A strain that was isolated in South Africa in 1977 was compared with invasive serotype 19A multidrug-resistant strains isolated in South Africa during June 1999 to December 2004. PFGE analysis of these isolates demonstrated clonal diversity among the isolates. MLST of 16 randomly selected isolates revealed several STs, none of which was the same ST as the 1977 clone. Both serotype 3 and 19A were not associated with increased mortality or HIV seropositivity compared to other serotypes.

The aim of this investigation was to clone, characterize and express the gene that encodes the outer capsid protein, VP2, of African horsesickness virus (AHSV), with a view to the evaluation of this protein as a subunit vaccine. The VP2 gene of AHSV serotype 3 (AHSV-3) was cloned as incomplete cDNA fragments of the genome segment 2 double-stranded (ds)RNA, sequenced in its entirety and compared with previously published cognate sequences of AHSV-4, Epizootic hemorrhagic disease virus (EHDV)-l and various bluetongue virus (BTV) serotypes. AHSV-3 genome segment 2 was shown to be 3221 nucleotides in length, encoding a protein of 1057 amino acids with a 50.5% identity to AHSV-4 VP2. Two areas of high variability (approximately 65%) were identified adjacent to the conserved termini. The N-proximal region (amino acids 128-309) exhibited significant hydrophilicity, suggesting a possible role in the determination of the serotype-specific immune response. Orbivirus interserogroup comparisons of VP2 amino acid sequences revealed extreme variability, although an overall structural conservation was demonstrated. Oligonucleotide primers derived from the AHSV-3 genome segment 2 terminal nucleotide sequences were used for PCR amplification and cloning of full length segment 2 cDNA. The cloned gene was expressed in a baculovirus expression system and the expressed VP2 protein was shown to react specifically with anti AHSV-3 serum in Western blots. Although the yields of VP2 in the baculovirus system were low, due to a possible toxic effect on the host cells, sufficient antigen was obtained for further future investigations into the efficacy of VP2 as a possible subunit vaccine against AHSV. / Dissertation (MSc)--University of Pretoria, 2010. / Genetics / unrestricted

No description available.

Infectious bronchitis virus (IBV) is a member of family Coronaviridae and is classified into group 3 of the Coronaviruses. The virus is a single-stranded positive-sense RNA virus with a genome of 27kbp. IBV is a highly infectious disease of chickens that results in high morbidity with moderate to severe mortality depending on the strain involved, age of the birds, and immune status of the chickens. Multiple worldwide investigations indicate that differentiation within the S1 glycoprotein gene can lead to serotype variation within the IBV species. In this study 46 isolates collected over two years from broiler and broiler breeder flocks and eight historical isolates were analyzed. Forty one isolates originated from the KwaZulu-Natal region whilst the remaining thirteen were isolated from 4 other poultry-dense provinces. The S1 gene was sequenced and compared to determine variation between South African isolates, as well as global sequences submitted to Genbank. The results indicate the division of isolates analyzed into 2 different clades of IBV within the province. The most prevalent genotype was similar to IBV Mass strain detected in 79% of the full S1 sequences. Variation up to 22.3% was detected within local strains, supporting the hypothesis that multiple IBV serotypes may co-circulate in the same region simultaneously. Additionally, more conservation was observed among Mass serotypes versus QX-like serotypes, implying that vaccine use can influence the variability within the IBV population. Higher variability was found in the first half of the S1 gene in comparison to the last half of the S1 gene. This is in agreement with previous findings that the hypervariable regions of the S1 gene are located within the first 450 base pairs. This study offers the first published consolidation of IBV isolates from South Africa and identifies variation within the IBV population of the SA broiler flock. Previous publications list four or five IBV isolates whilst this study describes variation found in 54 isolates spanning 32 years. In addition this study provides the insight into the prevalence of IBV variation in poultry flocks due to the large number of isolates. The comparative use of geno- and serotyping for South African IBV isolates is also described for the first time in this study. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Veterinary Tropical Diseases / unrestricted

CAVALHEIRO, N.P. Análise dos sorotipos do VHC identificados em pacientes da cidade de São Paulo, através de método imunoenzimático. São Paulo, 1999. 97p. Dissertação de mestrado - Faculdade de Medicina, Universidade de São Paulo. Com o objetivo de analisar a prevalência dos diferentes tipos do vírus da Hepatite C (VHC) em uma população de pacientes portadores crônicos do VHC, através de um método sorológico (MUREX HCV Serotyping Assay), foram estudados 219 pacientes, que apresentaram positiva a Reação em Cadeia da Polimerase (PCR), nested-PCR. Estes soros foram submetidos ao teste imunoenzimático para detecção dos anticorpos contra os tipos 1,2,3,4,5,6 do VHC. As amostras foram diluídas e incubadas na presença de peptídeos heterólogos de competição, com antígenos sorotipo-específicos do VHC. Dos 219 pacientes, foi possível detectar o sorotipo do VHC em 166, revelando uma sensibilidade de 75,8%. Os resultados apresentaram a predominância do tipo 1 (70,0%) em nosso meio, seguido pelo tipo 3 (22,3%) e tipo 2 (4,2%). Os sorotipos 4 e 5 estiveram presentes para 1,8% dos pacientes, sempre associados com o sorotipo 1. Estas amostras, apesar de cumprirem os quesitos de validade do teste, apresentaram leituras de Densidade Ótica muito altas para todos os tipos virais testados, inclusive controles positivo e negativo e a possibilidade de reações cruzadas, nestes casos, deve ser considerada. A confirmação por genotipagem e uma investigação mais detalhada sobre a procedência e formas de aquisição do VHC destes pacientes devem ser pesquisados. O tipo 6 não foi confirmado em nenhuma das amostras testadas e provavelmente não estava presente nesta coleção de amostras avaliadas. Os parâmetros epidemiológicos avaliados foram: idade, sexo e vias de transmissão. Dos 166 pacientes com diagnóstico para o tipo do VHC, 108 (65,1%) eram homens e 58 (34,9%) mulheres. A idade dos pacientes variou de 12 a 73 anos (média 41,1). As formas de transmissão mencionadas foram 52 (31,3%) transfusão de sangue, 18 (10,8%) uso de drogas injetáveis, 8 (4,8%) tatuagens, 6 (3,6%) provável via sexual, 3 (1,8%) acidente com agulha, 2 (1,2%) trabalho em área de saúde, 1 (0,6%) acupuntura, 1 (0,6%) hemofílico. Sessenta e um pacientes (36,7%) não apresentaram fatores de risco que justificassem a aquisição da infecção pelo VHC. Não foi verificada diferença significativa entre os tipos do VHC encontrados e os parâmetros epidemiológicos estudados. A predominância dos tipos 1, 3 e 2 é compatível com outros estudos, de genotipagem, que envolveram amostras brasileiras, particularmente da cidade de São Paulo. As amostras que apresentaram leituras de Densidade Ótica altas ou baixas, para todos os poços de uma mesma amostra testada, inclusive controles positivo e negativo, sugerem a possibilidade de reações inespecíficas ou cruzadas e devem ser confirmadas por outras técnicas de genotipagem ou seqüenciamento. A praticidade oferecida pelo teste de sorotipagem do VHC, apesar de não identificar os subtipos, pode ser útil na prática clínica e auxiliar no prognóstico da doença, não necessitando da tecnologia exigida pelos testes que envolvem biologia molecular. / CAVALHEIRO, N.P. Analysis of serotypes of HCV in patients from the city of São Paulo, by means of a enzyme-immunoassay method. São Paulo, 1999. 97p. Dissertação de Mestrado - Faculdade de Medicina, Universidade de São Paulo. With the objetive of analysing the prevalence of the different types of Hepatitis C Virus (HCV) in a population of chronic carriers of HCV, through a sorologic method (MUREX HCV Serotyping Assay), 219 patients were studied who showed a positive polymerase chain reaction. This sera were submitted to immunoenzimatic tests for the detection of antibodies in relation to HCV types 1, 2,3,4,5 and 6. The samples were diluted and incubated in the presence of heterologous competing peptides, with microwells coated with serotype-specific antigens of HCV. Of the 219 patients, it was possible to detect the HCV serotype in 166, revealing a sensitivity of 75.8%. The results showed a predominance of type 1 (70.0%) in our medium, followed by type 3 (22.3%) and type 2 (4.2%). Serotypes 4 and 5 were present in 1.8% of the patients, but always associated with serotype 1. These samples, in spite of fulfilling the prerequisites of validity for testing, showed a very high optical density reading for all types of viruses tested, including positive and negative controls. The possibility of cross reactions in these cases should be considered. Confirmation by genotyping and a more detailed investigation on the origin and mode of acquisition of the HCV of these patients should be researched. Type 6 was not confirmed in any of the samples tested and probably was not present in this particular collection. The epidemiological parameters evaluated were: age, sex and means of transmission. Of the 166 patients diagnosed with the HCV, 108 (65.1%) were men and 58 (34.9%) were women. The age of the patients varied from 12 to 73 years, the average being 41.1 years. The means of transmission mentioned were blood transfusion in 52 (31.3%) cases, intravenous drug use in 18 (10.8%) cases, by tatoos in 8 (4.8%) cases, 6 (3.6%) cases were sexually transmitted, 3 (1.8%) were by accident with a needle, 2 (1.2%) through work in the health field, one (0.6%) through acupunture and one by being hemophiliac. Sixty one (36.7%) patients were not able to offer any risk factor which justified the acquisition of the HCV infection. No significant difference was verified among the different types of HCV found and the different epidemiological parameters studied. The predominance of types 1, 3 and 2 is compatible with other genotyping studies which involved Brazilian samples, particularly in the city of São Paulo. The samples which showed high or low dense optical reading for all the wells of the same samples tested even the positive or negative controls, suggested confirmation by sequecing or genotyping. The praticality obtained by the HCV serotyping test, in spite of the fact that it does not identify the sub type, can be useful in clinical pratice and helpful in the prognostication of the disease, not needing the tecnology demanded by the tests which involve molecular biology.

Made available in DSpace on 2015-04-20T12:31:33Z (GMT). No. of bitstreams: 1 Regina Maria Pinto de Figueiredo.pdf: 895178 bytes, checksum: 18bad8fbb4a4c9f02c1af51dee70295b (MD5) Previous issue date: 2008-01-29 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Dengue virus infection increased significantly in Brazil during the last decade, particularly after 1994, as a consequence of Aedes aegypti dissemination. Vector dispersion was followed by the introduction of DEN-1, DEN-2 and DEN-3 serotypes in major Brazilian cities and the co-circulation of different serotypes has led to the first cases of dengue hemorrhagic fever (DHF). This study had as objectives: Isolate in cell culture samples of dengue virus circulating in the state of Amazonas; identify the serotypes of the dengue virus through sorologicas and molecular techniques; to correlate the clinical and laboratory most important cases of dengue, of dengue hemorrhagic fever (DHF) and dengue by shock syndrome (DSS), with each serotype; comparing the results obtained through the sequencing parcial of genes C and prM of samples of dengue found in this study compared with the sequences deposited in GenBank. Between January 2005 and June 2007, 534 blood samples were collected from patients with clinical symptoms of dengue fever who were negative for malaria. Anti-dengue immunoglobulin M (IgM) specific antibodies were detected in 90 (16.8%) samples, from those 40 (44.4%) were PCR-amplified, 13 (32.5%) were typed as DEN-2, 23 (57.5%) as DEN-3 and 4 (10%) as DEN-4. Among the 40 PCR-positive samples, 52 (57,7%) were also positive for viral culture. DEN-3 was isolated from two patients diagnosed with hemorrhagic fever by the WHO criteria. As this work reports the first detection of dengue type 4 viruses in Amazonas, DEN-4 was identified from the sera of three patients with co- infection two of them were DEN-3/DEN-4 co-infection and one DEN-2 / DEN-4. A greater incidence of DEN-3 in relation to DEN-2 and DEN-4, and the absence of DEN-1 circulation. / A infecção pelo vírus dengue aumentou significantemente no Brasil durante a última década, particularmente depois de 1994, como conseqüência da disseminação do Aedes aegypti. A dispersão do vetor foi seguida pela introdução dos sorotipos DEN-1, DEN-2 e DEN-3 nas principais cidades brasileiras e a co-circulação de diferentes sorotipos permitiu o surgimento dos primeiros casos de dengue hemorrágico (DHF). Este estudo teve como objetivos: Isolar em cultura de células amostras dos vírus dengue circulantes no Estado do Amazonas; identificar os sorotipos do vírus dengue por meio de técnicas sorológicas e moleculares; correlacionar os aspectos clínicos e laboratoriais mais importantes dos casos de dengue, febre hemorrágica do dengue (DHF) e da síndrome de choque por dengue (DSS), com cada sorotipo e comparar os resultados obtidos por seqüenciamento parcial dos genes C e prM das amostras de dengue encontradas neste estudo em comparação com seqüências depositadas no GenBank. Entre janeiro de 2005 e junho de 2007, 534 amostras de sangue foram coletadas de pacientes com sintomas clínicos de dengue e negativos para malária. Anticorpos específicos anti-dengue (IgM) foram detectados em 90 (16,8%) amostras, dessas 40 (44,4%) foram amplificadas, 13 (32,5%) foram tipadas como DEN-2, 23 (57,5%) como DEN-3 e 4 (10%) como DEN-4. Entre as 40 amostras positivas por PCR, 52 (57,7%) foram também positivas no isolamento viral. DEN-3 foi isolado de dois pacientes diagnosticados com DHF pelos critérios da Organização Mundial de Saúde (OMS). No presente trabalho foi também registrada a primeira detecção de DEN-4 no Amazonas. O sorotipo DEN-4 foi identificado em três casos de co- infecção, dois deles foram co- infecções de DEN-3/DEN-4 e um DEN-2 / DEN-4. Foi observada uma incidência de DEN-3 em relação ao DEN-2 e DEN-4, e a ausência da circulação de DEN-1.

CAVALHEIRO, N.P. Análise dos sorotipos do VHC identificados em pacientes da cidade de São Paulo, através de método imunoenzimático. São Paulo, 1999. 97p. Dissertação de mestrado - Faculdade de Medicina, Universidade de São Paulo. Com o objetivo de analisar a prevalência dos diferentes tipos do vírus da Hepatite C (VHC) em uma população de pacientes portadores crônicos do VHC, através de um método sorológico (MUREX HCV Serotyping Assay), foram estudados 219 pacientes, que apresentaram positiva a Reação em Cadeia da Polimerase (PCR), nested-PCR. Estes soros foram submetidos ao teste imunoenzimático para detecção dos anticorpos contra os tipos 1,2,3,4,5,6 do VHC. As amostras foram diluídas e incubadas na presença de peptídeos heterólogos de competição, com antígenos sorotipo-específicos do VHC. Dos 219 pacientes, foi possível detectar o sorotipo do VHC em 166, revelando uma sensibilidade de 75,8%. Os resultados apresentaram a predominância do tipo 1 (70,0%) em nosso meio, seguido pelo tipo 3 (22,3%) e tipo 2 (4,2%). Os sorotipos 4 e 5 estiveram presentes para 1,8% dos pacientes, sempre associados com o sorotipo 1. Estas amostras, apesar de cumprirem os quesitos de validade do teste, apresentaram leituras de Densidade Ótica muito altas para todos os tipos virais testados, inclusive controles positivo e negativo e a possibilidade de reações cruzadas, nestes casos, deve ser considerada. A confirmação por genotipagem e uma investigação mais detalhada sobre a procedência e formas de aquisição do VHC destes pacientes devem ser pesquisados. O tipo 6 não foi confirmado em nenhuma das amostras testadas e provavelmente não estava presente nesta coleção de amostras avaliadas. Os parâmetros epidemiológicos avaliados foram: idade, sexo e vias de transmissão. Dos 166 pacientes com diagnóstico para o tipo do VHC, 108 (65,1%) eram homens e 58 (34,9%) mulheres. A idade dos pacientes variou de 12 a 73 anos (média 41,1). As formas de transmissão mencionadas foram 52 (31,3%) transfusão de sangue, 18 (10,8%) uso de drogas injetáveis, 8 (4,8%) tatuagens, 6 (3,6%) provável via sexual, 3 (1,8%) acidente com agulha, 2 (1,2%) trabalho em área de saúde, 1 (0,6%) acupuntura, 1 (0,6%) hemofílico. Sessenta e um pacientes (36,7%) não apresentaram fatores de risco que justificassem a aquisição da infecção pelo VHC. Não foi verificada diferença significativa entre os tipos do VHC encontrados e os parâmetros epidemiológicos estudados. A predominância dos tipos 1, 3 e 2 é compatível com outros estudos, de genotipagem, que envolveram amostras brasileiras, particularmente da cidade de São Paulo. As amostras que apresentaram leituras de Densidade Ótica altas ou baixas, para todos os poços de uma mesma amostra testada, inclusive controles positivo e negativo, sugerem a possibilidade de reações inespecíficas ou cruzadas e devem ser confirmadas por outras técnicas de genotipagem ou seqüenciamento. A praticidade oferecida pelo teste de sorotipagem do VHC, apesar de não identificar os subtipos, pode ser útil na prática clínica e auxiliar no prognóstico da doença, não necessitando da tecnologia exigida pelos testes que envolvem biologia molecular. / CAVALHEIRO, N.P. Analysis of serotypes of HCV in patients from the city of São Paulo, by means of a enzyme-immunoassay method. São Paulo, 1999. 97p. Dissertação de Mestrado - Faculdade de Medicina, Universidade de São Paulo. With the objetive of analysing the prevalence of the different types of Hepatitis C Virus (HCV) in a population of chronic carriers of HCV, through a sorologic method (MUREX HCV Serotyping Assay), 219 patients were studied who showed a positive polymerase chain reaction. This sera were submitted to immunoenzimatic tests for the detection of antibodies in relation to HCV types 1, 2,3,4,5 and 6. The samples were diluted and incubated in the presence of heterologous competing peptides, with microwells coated with serotype-specific antigens of HCV. Of the 219 patients, it was possible to detect the HCV serotype in 166, revealing a sensitivity of 75.8%. The results showed a predominance of type 1 (70.0%) in our medium, followed by type 3 (22.3%) and type 2 (4.2%). Serotypes 4 and 5 were present in 1.8% of the patients, but always associated with serotype 1. These samples, in spite of fulfilling the prerequisites of validity for testing, showed a very high optical density reading for all types of viruses tested, including positive and negative controls. The possibility of cross reactions in these cases should be considered. Confirmation by genotyping and a more detailed investigation on the origin and mode of acquisition of the HCV of these patients should be researched. Type 6 was not confirmed in any of the samples tested and probably was not present in this particular collection. The epidemiological parameters evaluated were: age, sex and means of transmission. Of the 166 patients diagnosed with the HCV, 108 (65.1%) were men and 58 (34.9%) were women. The age of the patients varied from 12 to 73 years, the average being 41.1 years. The means of transmission mentioned were blood transfusion in 52 (31.3%) cases, intravenous drug use in 18 (10.8%) cases, by tatoos in 8 (4.8%) cases, 6 (3.6%) cases were sexually transmitted, 3 (1.8%) were by accident with a needle, 2 (1.2%) through work in the health field, one (0.6%) through acupunture and one by being hemophiliac. Sixty one (36.7%) patients were not able to offer any risk factor which justified the acquisition of the HCV infection. No significant difference was verified among the different types of HCV found and the different epidemiological parameters studied. The predominance of types 1, 3 and 2 is compatible with other genotyping studies which involved Brazilian samples, particularly in the city of São Paulo. The samples which showed high or low dense optical reading for all the wells of the same samples tested even the positive or negative controls, suggested confirmation by sequecing or genotyping. The praticality obtained by the HCV serotyping test, in spite of the fact that it does not identify the sub type, can be useful in clinical pratice and helpful in the prognostication of the disease, not needing the tecnology demanded by the tests which involve molecular biology.

Bluetongue (BT) is a non-contagious disease of mainly sheep but other ruminants like cattle, goats, and wild ruminants like alpacas, African antelopes and deer can also be affected. It is transmitted by Culicoides midges and its occurrence is seasonal, especially after good rains. The disease is subsiding when temperatures drop. The virus is distributed throughout the world in the tropical, subtropical and temperate areas where there are culicoides vectors which can transmit it (Tabachnick et al., 2011). This includes most countries in Africa, the Middle East, India, China, Australia, the United States of America, Canada and Mexico. Until 2008 24 BTV serotypes were known, but from 2008, data on the 25th serotype was published and recently, the 26th serotype has been identified (Hofmann et al., 2008; Maan et al., 2012a). In Africa 21 serotypes have been identified and BT is controlled mainly by annual vaccinations using a freeze–dried live attenuated polyvalent BTV vaccine. Currently the vaccine used in the Southern African Development Community (SADC) region is produced by Onderstepoort Biological Products (OBP). The vaccine is constituted of fifteen serotypes of the bluetongue virus (BTV) divided into three separate bottles. Each bottle contains five serotypes. The inoculation procedures are that bottle B is given three weeks after bottle A and bottle C three weeks after bottle B. The full immunity is established three weeks after the last bottle. The vaccine is effective and it induces both humoral and cellular immune response (Dungu et al., 2004). However, the challenge with the vaccine is that during outbreaks, sheep might not have nine full weeks to develop protection against the disease; and the farmer loses money on treatment and death of animals. Hence the purpose of the study is to determine whether the number of serotypes in the vaccine can be reduced without affecting efficacy; thus shorten the time taken for the full development of immunity after vaccination of animals. This study is based on previously reported cross-neutralization of specific BTV serotypes in in vitro studies by Howell et al. (1970) and Dungu et al. (2004). Bluetongue virus serotype 4 was selected for this trial and was tested for cross-protection against serotype 4 (control), 1, 8 (unrelated serotypes) 9, 10 and 11 in sheep using the serum neutralization test (SNT). The unvaccinated animals in all groups reacted to the challenge material. The animals vaccinated with and challenged with BTV-4, showed good immune response. Those animals that were vaccinated with BTV-4 and challenged with BTV-1 which is not directly related to BTV-4 (Howell et al., 1970), only 20% of the group was completely protected and did not show clinical signs other than a temperature reaction. The rest showed clinical signs, however the reaction was not as severe as the unvaccinated animal. The animals challenged with BTV-9 and 11 had good protection while those challenged with BTV-10, some showed good protection, some got very sick while others had mild clinical signs. The results showed that BTV serotype 4 do not only develop a specific immune response but can also protect against other serotypes. Future studies should be done looking at more serotypes but also look at the specific titres used per serotype in the vaccine. The development of cellular immunity should also be taken in consideration. With further studies it should be possible to develop a vaccine with fewer serotypes without compromising the immunity against the disease. / Dissertation (MSc)--University of Pretoria, 2012. / Veterinary Tropical Diseases / unrestricted

N/A / Thesis / Master of Science (MS)

Whole cells of Vibrio cholerare serotype Inaba and serotype Ogawa (strains I389 and O395) were injected into rabbits to obtain antiserum. The antiserums were used for immune reaction with antigenic components of 25 strains of V.cholerae isolated from five provinces of Vietnam and the two standard strains I389 and O395 by Western-blot technique. Analysis of immune hybrid results showed that there were 11 antigenic components with molecular weights approximately 79kDa, 62kDa, 52kDa, 45kDa, 42kDa, 38kDa, 35kDa, 31kDa, 26kDa, 23kDa and 20kDa. In which the antigens of 45kDa, 42kDa, 31kDa and 20kDa were similar to OmpT, OmpS, Omp-31kDa and TcpA that have been considered as vaccine-candidate antigens. Among 25 V.cholerae strains, there were 6 antigenic components in common including 79kDa, 62kDa, 45kDa, 35kDa, 31kDa and 20kDa. 23/25 strains contained 42kDa antigen; 5/25 strains contained 38kDa and 23kDa antigens; 11/25 had 26kDa antigen. In addition, 7/25 strains contained antigens identical to V.cholerae I389 serotype Inaba; 6/25 strains contained antigens of I389 and O395; 12/25 strains had changes of antigenic components. These changes were actually the lack of antigens, not appearing new antigens. These results are considered as basis for researches about immune response and prevention of cholera disease. / Toàn bộ tế bào của các chủng Vibrio cholerare typ huyết thanh Inaba và typ huyết thanh Ogawa (chủng I389 và O395) được sử dụng để gây miễn dịch trên thỏ để thu kháng huyết thanh. Các kháng huyết thanh được dùng để thực hiện phản ứng miễn dịch với các thành phần kháng nguyên của 25 chủng V.cholerae phân lập từ 5 tỉnh thành của Việt Nam và hai chủng chuẩn I389 và O395 bằng kỹ thuật Western-blot. Phân tích kết quả lai miễn dịch cho thấy, có tổng số 11 thành phần kháng nguyên có kích thước khoảng 79kDa, 62kDa, 52kDa, 45kDa, 42kDa, 38kDa, 35kDa, 31kDa, 26kDa, 23kDa và 20kDa. Các kháng nguyên này chủ yếu là các protein màng ngoài (Omp) và kháng nguyên lông (TcpA). Trong đó các kháng nguyên 45kDa, 42kDa, 31kDa và 20kDa trùng với các kháng nguyên OmpS, OmpT, Omp-31kDa và TcpA được xem là những kháng nguyên dự tuyển vacxin tả. Có 6 kháng nguyên chung giữa 25 chủng với kích thước 79kDa, 62kDa, 45kDa, 35kDa, 31kDa và 20kDa. 7/25 chủng có các kháng nguyên giống với kháng nguyên của chủng V. cholerae I389 typ huyết thanh Inaba; 6/25 chủng có các kháng nguyên giống với kháng nguyên của cả hai chủng V.cholerae I389 và O395; 12/25 chủng có sự biến đổi thành phần kháng nguyên. Tuy nhiên, sự biến đổi này thực chất là sự thiếu hụt chứ không phải là sự xuất hiện các thành phần kháng nguyên mới. Các kết quả nghiên cứu này có thể được xem là nền tảng ban đầu cho các nghiên cứu về miễn dịch và dự phòng bệnh tả.