Listeria-specific antigens

Mittrucker, H.W. et al., Role of CD28 for the generation and expansion of antigen-specific CD8+ T lymphocytes during infection with Listeria monocytogenes, J. Immunol., 167, 5620, 2001. 

Conlan JW, et al. Immunization of mice with lipopeptide antigens encapsulated in novel liposomes prepared from the polar lipids of various Archaeobacteria elicits rapid and prolonged specific protective immunity against infection with the facultative intracellular pathogen. Listeria monocytogenes. Vaccine 2001 19 3509. 

A Pz immunosensor for the detection of Listeria monocytogenes was published by Jacobs et al. [87]. The bacteria could be measured to 10 cellsmL using dip and dry methods of detection. Analysis carried out directly in solution allowed detection to 5 x 10 cells mL. Antibody coated crystals were stored for 17 days without detectable loss in activity. Protein A was used as the immobilisation method but not compared to others. Later the group published details of a displacement assay for the detection of this species [88]. This assay could detect the antigen from 2.5 x 10 to 2.5 x 10 cells/crystal directly in solution monitoring the response in real time. The assay was also performed in milk. Assays in milk were also shown to be specific for... 

Yamamoto K, Kawamura I, Tbminaga T et al. Listeriolysin O, a cytolysin derived from Listeria monocytogenes, inhibits generation of ovalbumin-specific Th2 immune response by skewing maturation of antigen-specific T-cells into Thl cells. Clin Exp Immunol 2005 142(2) 268-274. 

Listeria, after a preliminary enrichment step, a quick immunoassay step is used to establish possible positives, in which the presence of Listeria will be confirmed through microbiological tests. In the case of Salmonella, a preliminary enrichment step is followed by growth of the bacteria in a medium capable of stimulating production of the somatic and flagellar proteins that represent the specific reactive antigens detectable in subsequent immunoassay. 

ELISAs can be used in two modes, qualitatively to determine the presence or absence, or quantitatively to determine the amount of antigen present. ELISA kits often depend on the adsorption of either the antibody or antigen to a solid phase, e.g., wells of a microtiter plate, surface of plastic beads, or plastic stick. The choice of antibody (or antibodies) used determines the specificity of the ELISA assay, which can range from genus-specific to strain-specific. The principle on which ELISA methods are based usually prevents them from being used for the determination of total microbial counts. However, they can be used to detect pathogens such as Salmonella spp.. Listeria spp. 

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