Why we continue to use the name Propionibacterium acnes

Dear Editor, Propionibacterium acnes is a Gram‐positive anaerobic rod commonly associated with acne vulgaris. It is a normal commensal of the human skin and can be linked to a wide variety of diseases, such as central nervous system shunt infections, joint infections, endocarditis and prostate infection. We read with interest the proposal to reclassify selected species within the genus Propionibacterium to the proposed novel genus Cutibacterium.1 While we agree that there is a distinction between the traditionally named ‘cutaneous’ and the ‘classical’ or ‘dairy’ propionibacteria,2 there is no obligation to accept the new name and it is taxonomically valid to continue to use the name Propionibacterium. Propionibacterium acnes was previously placed in the genus Corynebacterium.3 In earlier literature the cutaneous group associated with infection was referred to as C. acnes3 or C. parvum.4 A common term in diagnostic bacteriology was ‘anaerobic coryneforms’, and it is only in recent years that this has been superseded with correct use of the genus and species name. A change of name would require large changes in educational updates, laboratory information systems and the public health sector, and even larger changes in the commercial sector to update product names, packaging, trademarks etc. We consider that the choice of genus name (Cutibacterium) is unnecessary, particularly in medical microbiology and dermatology. The editor‐in‐chief of the International Journal for Systematic and Evolutionary Microbiology, which publishes nomenclature changes, has confirmed that it is perfectly valid to continue to use the genus name Propionibacterium for the cutaneous group. Therefore, in order to avoid any confusion with the earlier nomenclature we encourage continued use of the term Propionibacterium acnes (P. acnes), and Propionibacterium for the cutaneous group within medical microbiology, infectious disease and dermatology specialties. Funding sources: none. Conflicts of interest: none to declare.