Abstract:Antiserum was prepared by immunizing SPF-grade Balb/C mice with the whole-cell protein of the highly virulent Listeria monocytogenes 819-2 strain. The extracellular proteome of the strain was analyzed using the immunoproteomics approach, to identify and obtain strong immunogenic proteins of L. monocytogenes as candidate antigens for specific antibody preparation. The whole-cell protein of the 819-2 strain was extracted using the ultrasonic method. The SPF-grade Balb/C mice were immunized four times using this protein extract to prepare antiserum, and the titer of the antiserum equaled 1:512 000 as measured using indirect ELISA. The extracellular protein of L. monocytogenes 819-2 strain was extracted using TCA precipitation with 10% (m/V) deoxycholate sodium (DOC). The spots for strong immunogenic proteins were identified with the help of immunoproteomics and LC-MS/MS. Two-dimensional electrophoresis results showed 85 protein spots and five strong immunogenic proteins, including P60, InlC, MltG, Enolase, and YxeA family protein, were successfully identified. The results provide a foundation for the preparation of specific antibodies based on highly immunogenic proteins for the enrichment and rapid detection of L. monocytogenes in food and food processing environments.
