Distribution of Salmonella paratyphi A ompA gene and immunological identification of the recombinant expressed product
10.3760/cma.j.issn.0254-5101.2010.01.001
- VernacularTitle:甲型副伤寒杆菌ompA基因分布及重组表达产物的免疫学鉴定
- Author:
Jinqin JIANG
;
Ping RUAN
;
Wei DING
;
Aihua SUN
;
Yafei MAO
;
Jie YAN
- Publication Type:Journal Article
- Keywords:
Salmonella paratyphi A;
ompA gene;
Recombinant expression;
Immunogenicity;
Im-munoprotection
- From:
Chinese Journal of Microbiology and Immunology
2010;30(1):1-5
- CountryChina
- Language:Chinese
-
Abstract:
Objective To construct a prokaryotic expression vector of Salmonella paratyphi A ompA gene, and to determine immunogenieity and immonuprotection of the recombinant expressed product rOmpA and carrying frequency of ompA gene in S. paratyphi A isolates. Methods ompA gene was amplified from a clinical S. paratyphi A strain JH01 by PCR, cloned into T-A cloning vector, and then the prokaryotic expression vector was constructed. The rOmpA expression was determined by SDS-PAGE. Antigenicity and immunoreactivity of rOmpA were determined by immunodiffusion test, Micro-Widal's test and Western blot assay, ompA gene exiting in 98 S. paratyphi A isolates was detected by PCR. By using immunoprotective effect of rOmpA against the challenge of S. paratyphi A strain 50001 in mice were determinded. Results Both the nucleotide and putative amino acid sequence identities of the cloned ompA gene were 100% com-pared to the reported corresponding sequences. The expression yield of rOmpA was approximately 65% of the total bacterial proteins, rOmpA was able to induce specific antibody in rabbits, and reacted efficiently with rabbit antisortm or the antiserum against whole cell of S. paratyphi A detected by Western blot. 94.9% (93/98) of the S. paratyphi A isolates had ompA gene. 41.7% (5/12) and 58.3% (7/12) of the mice im-murtized with 100 and 200 μg rOmpA were survival after lethal challenge with S. paratyphi A strain 50001. The titer of antibody to the H antigens of S. paratyphi spp in the sera from rOmpA immunized mice and sur-viral mice in the S. paratyphi A challenge detected by Micro-Widal's test was 1:5-1:40. Conclusion ompA gene has an extensive distribution in clinical isolates of S. paratyphi A. rOmpA possesses an immunogenicity and a certain immunoprotective effect, and can be used as the candidate antigen in genetic engineering vaccine.
