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ARS Home » Research » Publications at this Location » Publication #47501
Title: SEROLOGICAL RESPONSE TO OUTER MEMBRANE PROTEINS FOLLOWING INFECTION AND IMMUNIZATION WITH SALMONELLA TYPHIMURIUM IN CATTLE AND SHEEP

Author
item KWANG JIMMY - 5438-01-35
item Littledike, E

Submitted to: Veterinary Immunology International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 2/16/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The outer membrane of Salmonella contains three major outer membrane proteins (omp): ompC, ompF, and ompA. The ompC and ompF are pore-forming proteins (porins) which facilitate the transport of small molecules into the bacterial cells. The ompA is important for maintaining the integrity of the outer membrane. Other workers have characterized the serological responses to omp following active immunization of mice with Sal. typhimurium and of cattle with Sal. dublin. Their results showed that the immune response of the host to omp plays a role in providing protection against the disease and serves as an important marker for Sal. infection. In order to characterize the B-cell determinants of omp following Sal. challenge, we cloned six gene fragments from ompC and ompA and expressed them in Escherichia coli. The resultant recombinant proteins were purified using a glutathione sepharose-4B chromatograph column. The purified proteins were used in an immunoblot assay and an ELISA assay to analyze the serological response of cattle and sheep infected or immunized with Sal. The most immunogenic regions of ompA and ompC were localized. The sensitivity and specificity of the assays were evaluated by comparing the results of our OMP assays with results using LPS as a solid-phase antigen in an ELISA. Sera from cattle and sheep that tested positive using the Sal. omp antigen also tested positive using the Sal. LPS antigen.