Abstract: BALB/c mice were immunized with Cronobacter sakazakii type strain ATCC 29004. Seven strains (1E9, 2A7, 2D10, 3E5, 5B10, 6E3, and 12A2) of hybridoma cell lines that secreted monoclonal antibodies were prepared by two cycles of cell fusion using hybridoma technique. The titers of 2A7, 2D10, 3E5 and 12A2 reached 1:256 000, the titer of 6E3 was 1:128 000, the titer of 5B10 was 1:64 000 and the titer of 1E9 was 1:32 000. The results of subtype identification showed that the subtype of 1E9 was IgG1, the subtype of 6E3 was IgG2b, and the subtypes of the other antibodies 2A7, 2D10, 3E5, 5B10 and 12A2 were all IgG2a. 2A7 could specifically bind to 3 strains of Cronobacter sakazakii (ATCC 29004, ATCC 29544, and ATCC 12868), and 1E9 could specifically bind to two of them (ATCC 29004 and ATCC 12868). The results of cross-reaction with 11 other similar pathogens showed that 7 antibodies had good specificity. The sensitivity of indirect competitive enzyme linked immunosorbent assay (ELISA) using 2A7 reached 106 CFU/mL for the detection of Cronobacter sakazakii.

Key words: Cronobacter sakazakii, monoclonal antibodies, indirect competitive enzyme linked immunosorbent assay (ELISA)