VetBactBlog

Names of the category “phylum” in the taxonomic hierarchy of bacteria were earlier not regulated in the [International Code of Nomenclature of Prokaryotes (ICNP)]. However, in February 2021, the members of the International Committee on Systematics of Prokaryotes (ICSP) have decided that naming of phyla must also be regulated in ICNP. The new names of 42 bacterial phyla were published in an article entitled: Valid publication of the names of forty-two phyla of prokaryotes by Ahron Oren and George M. Garrity. The following rules are important for naming of phyla:

1. In the names of phyla, -ota must be used as the ending.

2. Italics must be used for names of phyla in text.

3. A phylum name must be based on a genus, which constitutes the nomenclature type of the phylum in question.

The order Enterobacterales (formely called Enterobacteriales) is a large taxon containing many bacteria of veterinary importance. The members of this taxon have different properties and form a number of distinct phylogenetic groups. Six new families have now been introduced within the order Enterobacterales, which makes the new taxonomy to better reflect the phylogeny of this group. These new families are: Budviciaceae, Erwiniaceae, Hafniaceae, Morganellaceae, Pectobacteriaceae and Yersiniaceae. Four of these families are represented on VetBact and the genera that are relevant are indicated within parentheses for the respected family: Erwiniaceae (Pantoea), Hafniaceae (Edwardsiella), Morganellaceae (Morganella and Proteus) and Yersiniaceae (Serratia and Yersinia). The bacterium Plesiomonas shigelloides has not yet been assigned to a new family and therefore, it stands as inserta sedis. For more information, see article by J. M. Janda & S. L. Abbott.

The taxonomy of the mollicutes (mycoplasmas) has finally been revised thanks to a Canadian and an Israeli research group. This revised taxonomy is based on data from whole genome sequencing of 140 mollicutes. Only members of the so-called mycoides group are still included in the order Mycoplasmatales. Other former members of this order have now been transferred to the order Mycoplasmoidales. This new order Mycoplasmoidales has been divided into the two families Mycoplasmoidaceae and Metamycoplasmataceae, which have been further subdivided into five different genera (see figure). The important purpose of the revision of the taxonomy of the mollicutes was to get a taxonomy that reflects the actual phylogeny of these bacteria. Read more about this new taxonomy in the term list of VetBact under Taxonomy of mollicutes (mycoplasmas).