Genotypic and phenotypic characterization of Bordetella pertussis strains used in different vaccine formulations in Latin America

Abstract

Aim: To characterize <i>Bordetella pertussis</i> vaccine strains in comparison with current circulating bacteria. Methods and Results: Genomic and proteomic analyses of <i>Bp</i>137 were performed in comparison with other vaccine strains used in Latin America (<i>Bp</i>509 and <i>Bp</i>10536) and with the clinical Argentinean isolate <i>Bp</i>106. Tohama I strain was used as reference strain. Pulse-field gel electrophoresis (PFGE) and pertussis toxin promoter (<i>ptx</i>P) sequence analysis revealed that <i>Bp</i>137 groups with <i>Bp</i>509 in PFGE group III and contains <i>ptx</i>P2 sequence. Tohama I (group II) and <i>Bp</i>10536 (group I) contain <i>ptx</i>P1 sequence, while <i>Bp</i>106 belongs to a different PFGE cluster and contains <i>ptx</i>P3. Surface protein profiles diverged in at least 24 peptide subunits among the studied strains. From these 24 differential proteins, <i>Bp</i>10536 shared the expression of ten proteins with Tohama I and <i>Bp</i>509, but only three with <i>Bp</i>137. In contrast, seven proteins were detected exclusively in <i>Bp</i>137 and <i>Bp</i>106. Conclusions: <i>Bp</i>137 showed more features in common with the clinical isolate <i>Bp</i>106 than the other vaccine strains here included. Significance and Impact of the Study: The results presented show that the old strains included in vaccines are not all equal among them. These findings together with the data of circulating bacteria should be taken into account to select the best vaccine to be included in a national immunization programme.