Bordetella Pertussis Fimbriae (Fim2 and Fim3) Expression Evaluation in Different Stages of Cultivation to Produce Vaccine

Fimbriae (Fim2 and Fim3) are one of the most important virulence factors in Bordetella pertussis and it causes the adhesion of bacteria to the upper respiratory tract cells and that enhances immune response. The level of antibody production against fimbriae is directly related to the level of protection. Fimbriae is one of the main components in both whole-cell and acellular pertussis vaccines. According to WHO standard, in the whole-cell vaccine, presence of fimbriae must be confirmed by two techniques including ELISA and slide agglutination.
Subjects and In this research, two strains of B. pertussis 509 (with Fim2) and 134 (with Fim3) were tested by culturing in B2 and presentation of fimbriae was assessed at different stages of cultivation. In this study indirect ELISA and slide agglutination assays were used to determine and evaluate the presence and quantity of the fimbriae during cultivation period. After confirming the presence of the fimbriae, two strains (134 and 509) were cultured in B2 medium; and according to the fimbriae expression, the best time for harvesting and stopping the cultivation was determined.
The high level of fimbriae expression and the best time for harvesting and stopping the culture was in the log phase. However, the level of expression in two strains was dissimilar in different time points, but eventually the most expression level was in the log phase.
According to the results of the highest expression of Fim2 and Fim3, and the best time for bacterial removal of the bacterial logarithmic phase governor. Although the expressions of these two fimbriae differ in this phase, the ultimate fimbria presence is in this phase.