Proposal for reunification of the genus Raoultella with the genus Klebsiella and reclassification of Raoultella electrica as Klebsiella electrica comb. nov.

The order Enterobacterales was divided into seven families including the family Enterobacteriaceae in 2016. The genus Klebsiella within the family Enterobacteriaceae was divided into two genera Klebsiella and Raoultella in 2001. Here, our phylogenomic analysis shows that the genus Raoultella is nested within the genus Klebsiella. Klebsiella and Raoultella together are monophyletic and share average amino acid identities (AAIs) of 86.9-89.6% above the AAI threshold (86%) for genus delimitation within the family Enterobacteriaceae. Klebsiella and Raoultella share AAIs of 79.9%-85.0% with the other genera within the subfamily Klebsiella clade, which are in the range of inter-genus AAIs (74-85%) within the family Enterobacteriaceae. Klebsiella and Raoultella also share six known conserved signature indels. Therefore, we propose to reunify Klebsiella and Raoultella to the single genus Klebsiella and reclassify Raoultella electrica as Klebsiella electrica comb. nov. Our genome-based taxonomic analyses also identified seven potential novel species within the unified genus Klebsiella. (c) 2021 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Automated summary

This study reveals that the genus Raoultella is nested within the genus Klebsiella, leading to the proposal of reunifying Klebsiella and Raoultella under the single genus Klebsiella. Additionally, seven potential novel species were identified within the unified genus Klebsiella through genome-based taxonomic analyses.