Preparation Of Specific Antibodies Against Listeria Monocytogenes

Listeria monocytogenes(LM, L.monocytogenes) is an important foodborne pathogens which widely distributed in nature and has varied routes of infection. In recent years, frequent outbreaks of large-scale of listeriosis have caused great attention. Traditional detection technology, molecular detection technology and immunological detection technology are three major means in detection of Listeria monocytogenes. These methods have their own advantages and disadvantages in specificity,sensitivity,detection period and operating cost. As far as immunological detection technology was concerned, rapid, sensitive, specific and easy to judge are its distinguishing features, but antibody specificity limits detection sensitivity and accuracy to a great extent. Therefore, preparation of specific antibodies against L. monocytogenes is of great significance and primary prerequisite to establish immunological detection technique .Rapid isolation and identification method was established employing Fraser enrichment broth combining PALCAM medium and PCR amplification (or 16S rDNA sequencing) scheme based on national standard separation methods and ISO standard. Separation and indentification work can be finished within 3-5d using this method. In addition, this method not only can be applied to basic isolation and identification work in laboratory, but also to large-scale of isolation work especially.We used 3 three inactivated methods(UV-inactivated,heat-inactivated and acidic electrolyzed water(AEW)-inactivate)to deal with Listeria monocytogenes for preparation of immune antigen, and then compared and analysed their immunogenicity. Related datum confirmed that UV- inactivated strains have the best immunogenicity and AEW-inactivated strains have the worst effective. We concluded that immunogenicity and surface integrity of bacteria have a certain relationship to some extent combining scanning electron microscope photographs and this conclusion can provid reference value for preparation of bacteria antigen.Monoclonal and polyclonal antibodies were produced after immunizing BALB/c mice and New Zealand white rabbit with UV-inactivated antigen separately. A specific hybridoma cell lines and dozens of milliliter polyclonal antibody were obtained at last. Secrete antibodies response to Listeria monocytogenes specificity and have weaker cross reaction with the other bacteria of Listeria species. Polyclonal antibody can identify Listeria bacteria specifically. This paper disscused application feasibility of specific antibodies from the two basic aspects of enrichment and detection. Experimental results demonstrate that those antibodies have corresponding application value.This study lays material foundation and is of great significance for establishing and promoting immunological detection technique.