A Simple Surface Antigen-Specific Monoclonal Antibody Based Dot-ELISA For The Identification of Listeria Monocytogenes

Abstract- Listeria Monocytogenes is a human pathogen transmission of this bacterium is mainly through food especially milk and milk products and also from non vegetarian food products like mutton poultry beef fish and pork. L. Monocytogenes outbreaks are due to contaminated foods which emphasizes the need to develop a rapid and cost effective detection. Monoclonal antibodies with specificities of different epitopes were generated against whole cell antigens of formalinized L. Monocytogenesis cells. Six MAbs from the fusion were tested against 12 L. Monocytogenes standard strains and 69 wild-type isolates obtained from naturally contaminated food products Mab107 showed specificity to L. Monocytogenes in Plate ELISA and Western blot. Utilising this clone a simple monoclonal antibody based dot-ELISA system was standardized for rapid detection of L. Monocytogenes from contaminated food stuffs. Developed system was successfully evaluated on to different food matrices collected from local markets of Karnataka and ELISA results were cross checked with conventional and PCR method as well where listeriolysin O gene was targeted and standardised in house. To assess the cross-reactivity of the Mab tests were made using standard strains of Listeria along with that closer group of other Listeria species and other bacterial genera. The cost effectiveness sensitivity specificity and reliability of the method proved to be good. Therefore the system can be used in routine diagnostic laboratories.