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Protection against typhoid in mice immunized with phospholipase A fractions of Salmonella typhi
Conference Abstracts
Protection against typhoid in mice immunized with phospholipase A fractions of Salmonella typhi V. Punj, M.S. Kalra .and Hittu Matta
Department of Microbiology, College of Basic Sciences & Humanities, PA U, Ludhiana-141004, India The present investigation was undertaken to evaluate the protective immunity induced by phospholipase A fractions of Salmonella typhi against challenge with bacteria in mucin. Immunoblot analysis revealed protein bands corresponding to 45 KDa and 65 KDa to be predominantly immunogenic in extra and intracellular fractions, respectively. Immunization with as little as 50 pg purified extracellular protein conferred 80% protection to mice challenged up to 500 LDs0 of S. typhi. An active protection of 90 and 100% was observed by immunization with crude (CIP) and purified (PIP) intracellular
phospholipase A respectively against challenge with 500 LDso. Rabbit antiserum raised against both CIP and PIP fractions protected 90% of mice challenged against 250 and 500 LDso of S. typhi. Though the passive protection with rabbit anti-CIP proved to be less effective as compared to active immunization but still CIP was found to be a potent immunogen from all the four fractions. The results suggest implication of other mechanisms besides serum antibodies in protection against S. typhi in mucin-mice model.
Evaluation of immunoprophylactic activities of purified porins of Salmonella typhi 0-901 and Salmonella typhimurium Ra-30 B. Tabaraie, B.K. Sharma, P. Sharma and N.K. Ganguly
Department of Experimental Medicine, Post-Graduate Institute of Medical Education & Research, Chandigarh 160012, India Immunoprophylaxis of Salmonella infections with common antigens has not been possible to date despite extensive research. In the present study protective and cross-Protective activities of purified porins isolated from smooth strain of S. typhi 0-901 and Ra-Chemotype of rough S. typhimurium-30 were evaluated. Using murin salmonellosis model, high level of protection and cross-Protection has been observed against subsequent exposure to lethal doses of S. typhimurium LT-71 or S. enteritidis SH-1269 virulent strain in mice via active or
passive immunization with either porins or LPS-absorbed antiporins antiserum. Similar type of homology was observed when S. typhi 0-901 anti-porins antiserum was allowed to react with both homologous and heterologous porins in immunoblotting technique. In addition it was shown that minor LPS contamination in our preparation ( <0.01% ) does not play any essential role in such activities. The results of our study reveals the porin as a potential immunogen with broad immunoprophylactic activities against salmonellosis.
Construction of a bivalent candidate vaccine strain against ETEC and Salmonella disease Tianmi Chen, Xiao Yang, Beining Zhang, Xinbo Cheng and Cuifen Huang
Molecular Genetics Center, Institute of Biotechnology, 27 Taiping Road, Beo'ing 100850, People's Republic of China Enterotoxigenic E. coli (ETEC) is one of the most important pathogens that cause diarrhea in China, especially in children less than 5 years old. The main pathogenic factor - the heat-labile (LT) operon was isolated from the large plasmid of ETEC and a clone that effectively expressed LT was obtained. The B subunit gene of LT that codes antigenical component without toxicity was isolated and subsequently subcloned into a vector plasmid carrrying a asd ÷ gene marker. The recombinant plasmid was introduced into an avirulent Acya Acrp Aasd strain of Salmonella typhimurium by twice
transformations. The hybrid strain was a balanced lethal recombinant without drug resistant gene and the LTB expressed to have immunogenic activity at high level. This strain afforded protection to animal models after immunization orally or parenterically. Since avirulent S. typhimurium strains could invade the GALT and stimulate immunoreaction, the strain we constructed could be considered as a candidate bivalent live oral vaccine strain against ETEC diarrhea and relative Salmonella disease.
Prophylaxis of Salmonella (S.) abortus ovis caused abortions of sheep by a S. typhimurium live vaccine K. Linde 1 and V. Bondarenko 2
~Institut fftr Medizinische Mikrobiologie und Epidemiologie, University of Leipzig, Liebigstr. 24, Leipzig 7010, Germany, 2Moscow Medical Academy, Gramaleya Street 18, Moscow, USSR A S. typhimurium live vaccine with optimal level of attenuation for sheep, constructed by means of 'metabolic drift' mutations, was tested for its efficacy against S. caused abortions. In two
278
Vaccine, Vol. 10, Issue 4, 1992
field trials in Kirgiziya, 25000 to 100000 first delivery sheep received a fully tolerated single s.c. dose of 109 cfu live vaccine shortly before and up to four months after insemination, or
Protection against typhoid in mice immunized with phospholipase A fractions of Salmonella typhi V. Punj, M.S. Kalra .and Hittu Matta
Department of Microbiology, College of Basic Sciences & Humanities, PA U, Ludhiana-141004, India The present investigation was undertaken to evaluate the protective immunity induced by phospholipase A fractions of Salmonella typhi against challenge with bacteria in mucin. Immunoblot analysis revealed protein bands corresponding to 45 KDa and 65 KDa to be predominantly immunogenic in extra and intracellular fractions, respectively. Immunization with as little as 50 pg purified extracellular protein conferred 80% protection to mice challenged up to 500 LDs0 of S. typhi. An active protection of 90 and 100% was observed by immunization with crude (CIP) and purified (PIP) intracellular
phospholipase A respectively against challenge with 500 LDso. Rabbit antiserum raised against both CIP and PIP fractions protected 90% of mice challenged against 250 and 500 LDso of S. typhi. Though the passive protection with rabbit anti-CIP proved to be less effective as compared to active immunization but still CIP was found to be a potent immunogen from all the four fractions. The results suggest implication of other mechanisms besides serum antibodies in protection against S. typhi in mucin-mice model.
Evaluation of immunoprophylactic activities of purified porins of Salmonella typhi 0-901 and Salmonella typhimurium Ra-30 B. Tabaraie, B.K. Sharma, P. Sharma and N.K. Ganguly
Department of Experimental Medicine, Post-Graduate Institute of Medical Education & Research, Chandigarh 160012, India Immunoprophylaxis of Salmonella infections with common antigens has not been possible to date despite extensive research. In the present study protective and cross-Protective activities of purified porins isolated from smooth strain of S. typhi 0-901 and Ra-Chemotype of rough S. typhimurium-30 were evaluated. Using murin salmonellosis model, high level of protection and cross-Protection has been observed against subsequent exposure to lethal doses of S. typhimurium LT-71 or S. enteritidis SH-1269 virulent strain in mice via active or
passive immunization with either porins or LPS-absorbed antiporins antiserum. Similar type of homology was observed when S. typhi 0-901 anti-porins antiserum was allowed to react with both homologous and heterologous porins in immunoblotting technique. In addition it was shown that minor LPS contamination in our preparation ( <0.01% ) does not play any essential role in such activities. The results of our study reveals the porin as a potential immunogen with broad immunoprophylactic activities against salmonellosis.
Construction of a bivalent candidate vaccine strain against ETEC and Salmonella disease Tianmi Chen, Xiao Yang, Beining Zhang, Xinbo Cheng and Cuifen Huang
Molecular Genetics Center, Institute of Biotechnology, 27 Taiping Road, Beo'ing 100850, People's Republic of China Enterotoxigenic E. coli (ETEC) is one of the most important pathogens that cause diarrhea in China, especially in children less than 5 years old. The main pathogenic factor - the heat-labile (LT) operon was isolated from the large plasmid of ETEC and a clone that effectively expressed LT was obtained. The B subunit gene of LT that codes antigenical component without toxicity was isolated and subsequently subcloned into a vector plasmid carrrying a asd ÷ gene marker. The recombinant plasmid was introduced into an avirulent Acya Acrp Aasd strain of Salmonella typhimurium by twice
transformations. The hybrid strain was a balanced lethal recombinant without drug resistant gene and the LTB expressed to have immunogenic activity at high level. This strain afforded protection to animal models after immunization orally or parenterically. Since avirulent S. typhimurium strains could invade the GALT and stimulate immunoreaction, the strain we constructed could be considered as a candidate bivalent live oral vaccine strain against ETEC diarrhea and relative Salmonella disease.
Prophylaxis of Salmonella (S.) abortus ovis caused abortions of sheep by a S. typhimurium live vaccine K. Linde 1 and V. Bondarenko 2
~Institut fftr Medizinische Mikrobiologie und Epidemiologie, University of Leipzig, Liebigstr. 24, Leipzig 7010, Germany, 2Moscow Medical Academy, Gramaleya Street 18, Moscow, USSR A S. typhimurium live vaccine with optimal level of attenuation for sheep, constructed by means of 'metabolic drift' mutations, was tested for its efficacy against S. caused abortions. In two
278
Vaccine, Vol. 10, Issue 4, 1992
field trials in Kirgiziya, 25000 to 100000 first delivery sheep received a fully tolerated single s.c. dose of 109 cfu live vaccine shortly before and up to four months after insemination, or