RT Journal Article
SR Electronic
T1 Revisiting the evolution and taxonomy of Clostridia, a phylogenomic update
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 546341
DO 10.1101/546341
A1 Pablo Cruz-Morales
A1 Camila A. Orellana
A1 George Moutafis
A1 Glenn Moonen
A1 Gonzalo Rincon
A1 Lars K Nielsen
A1 Esteban Marcellin
YR 2019
UL http://biorxiv.org/content/early/2019/02/11/546341.abstract
AB Clostridium is a large genus of obligate anaerobes belonging to the Firmicutes phylum of bacteria, most of which have a Gram-positive cell wall structure. The genus includes significant human and animal pathogens, causative of potentially deadly diseases such as tetanus and botulism. Despite their relevance and many studies suggesting that they are not a monophyletic group, the taxonomy of the group has largely been neglected. Currently, species belonging to the genus are placed in the unnatural order defined as Clostridiales, which includes the class Clostridia. Here we used genomic data from 779 strains to study the taxonomy and evolution of the group. This analysis allowed us to; (i) confirm that the group is composed of more than one genus (ii), detect major differences between pathogens classified as a single species within the group of authentic Clostridium spp. (sensu stricto), identify inconsistencies between taxonomy and toxin evolution that reflect on the pervasive misclassification of strains and, (iv) identify differential traits within central metabolism of members of what has been defined earlier and confirmed by us as cluster I. Our analysis shows that the current taxonomic classification of Clostridium species hinders the prediction of functions and traits, suggests a new classification for this fascinating class of bacteria and highlights the importance of phylogenomics for taxonomic studies.