Serotype and fimbriae-genotype analysis of Chinese Bordetella pertussis strains / 中华微生物学和免疫学杂志

ABSTRACT

Objective To understand serotype and fimbriae-genotype of B. pertussis vaccine strains and isolates from different periods in China. Methods Serotype of eighty isolates and three vaccine strains were determined using anti-fim2 and fim3 monoclonal antibodies compared with polyclonal antisera. Fim2 and fim 3 genes were amplified by PCR and the amplified products were sequenced and analyzed . Results The serotype of three vaccine strains and all isolates but only one tested by the slide agglutination and micro-plate assay of anti-fim2 and fim3 monoclonal antibodies were the same in comparison with that of the slide agglutination of polyconal antisera. In this study, seventeen isolates and vaccine strains CS and P3S10 were fim2&3 serotype, and forty-eight isolates were tim2 serotype while fifteen isolates and vaccine strain 18530 were fim3 serotype. The predominant serotypes were fim2 and fim2&3 before Expanded Program on Immuni-zation in 1978, while the find became the most popular serotype after nation-wide pertussis vaccination in China. The fim2-1 and fim3-A genotype was the most common type, which was identified in 92.5% and 95.0% of the isolates, respectively. The genotype of vaccine strain 18530 was fim2-2 and fim3-A while oth-er vaccine strains were fim2-1 and fim3-A. The isolates contained fim3-B and fim3-D subtypes were found since 2000. These data indicated that the serotype and fimbriae genotype of B. pertussis isolates have been changed for immune environment of national-wide pertussis vaccination in China. Conclusion The validity and specificity of anti-fim2 and fim3 monoclonal antibodies have been validated for serotyping of B. pertussis strains. The information of serotype and fimbirae genotype of B. pertussis vaccine strains and isolates from dif-ferent time periods have been obtained. These data can facilitate the studies on quality control of vaccine strain, epidemiology and the evolution of B. pertussis in China.