Comparative Phylogeny of the Genus Bordetella Using Sequence Analysis of 16S rRNA and ompA Genes

Abstract

Background: The genus Bordetella harbors 16 species; three of them are well-known for their high medical importance. The phylogenetic diversity of the genus is currently not very well investigated. Methods: In this study, 16S rRNA gene sequence of 16 type strains of the Bordetella species were analyzed. Also, phylogenies conducted on the same gene of 247 isolates of Bordetella species, comprising a wide physiological as well as ecological diversity and encompassing ex-type representatives of the 16 Bordetella species, were analyzed. Results: It was found that the phylogenetic diversity of the genus may be very different from that is currently assumed. Interestingly, the 16S rRNA gene signals could not resolve some species with promising bootstrap and posterior probability values as our phylogenies, using maximum likelihood and Bayesian inference methods, showed. Conclusion: Our results indicate a probable need for additional phylogenetic signals which can be provided by coding genes. Therefore, sequence data of ompA gene of Bordetella species, a critically significant genomic region in pathogenesis, was here analyzed, phylogenetically. This gene confirmed the tree topology and the phylogenetic species boundaries already revealed by the 16S rRNA gene, but showed a better discriminatory power which resolved Bordetella species with higher statistically significant values.

Keywords

• Alcaligenaceae
• Biogeography
• Bordetella species
• Ecological distribution
• Phylogenetic species concept