Search

Introduction: Whooping cough is still a significant disease with regular outbreaks despite the decades of mass vaccination and good immunization coverage. The aim of this study was to evaluate the capacity of Bordetella pertussis toxicity testing among strains harbouring different alleles of the pertussis toxin promoter ptxP using hamster ovary cell line CHO (Hamster Ovary)., Methods: The study assessed the limits of detection of high and low Ptx levels producing strains using a reference preparation ofpertussis toxin and B. pertussis strains that increased toxicity in vitro has been previously correlated with ptxP3 allele presence., Results: The presence of the strong agglomerates on CHO cell line confirmed the higher toxicity of B. pertussis strains isolated in France. Preliminary toxicity study with use of selected strains of B. pertussis differing by ptxP1 and ptxP3 promdter alleles with respect to relevant reference preparation indicate lower toxicity of strains B. pertussis isolated in Poland., Conclusions: The toxicity measured on CHO line will be used to assess the virulence of all available B. pertussis strains isolated in Poland.

The low recovery of pertussis toxin (PT) and the low resolving efficiency of chromatography, due to the instability of PT in low salt condition, are the main challenges for its purification. We aplied 2 mol/L urea to prevent the aggregation and disassociation of PT during the purification by ion-exchange chromatography (IEC) and gel filtration chromatography (GFC). The effect of urea on the purification of PT was studied by ELISA assay and non-reduced SDS-PAGE. The activity recoveries of PT and filamentous hemagglutinin (FHA) in IEC and GFC, the resolution efficiency in GFC and the purities of PT and FHA were improved obviously by adding 2 mol/L urea in the mobile phase. The results highlight the potential application of urea in the acellular pertussis vaccine (APV) manufacture procedure.