An update on novel taxa and revised taxonomic status of bacteria isolated from human clinical specimens described in 2024.

Knowledge of novel and revised bacterial taxonomy facilitates routine operations in the medical microbiology laboratory and communication with important stakeholders. Notable new gram-positive taxa accepted in 2024 include the clinically significant Staphylococcus brunensis sp. nov., as well as Streptococcus suis subsp. hashimotonensis subsp. nov., which can be delineated from other Streptococcus suis subsp. by possession of the Lancefield group A antigen. Four novel Enterobacterales species are discussed, plus a novel eighth family Gallaecimonadaceae. One of these, Providencia huashanensis sp. nov. is clinically significant and harbors multiple genetic determinants that encode antimicrobial resistance mechanisms. Stenotrophomonas forensis sp. nov., derived from specimen transport medium, was determined to be a distinct component within the Stenotrophomonas maltophilia complex. Bartonella tamiae sp. nov. has become officially recognized as the agent of the first culture-confirmed bartonelloses in Thailand. Significant taxonomic revisions include the return of Chlamydophila caviae to the Chlamydia genus, creation of the novel Metaclostridioides genus for Clostridioides mangenotii, and reclassification of two Kocuria spp. into two subspecies of Kocuria rosea. Clinical updates are provided for 13 past Journal of Clinical Microbiology taxonomic compendium entries for which extensive clinical data were not previously available. These include potential clinical significance for non-vaginalis species of the Gardnerella genus and for Pandoraea commovens in a non-cystic fibrosis setting.