title: Dissecting the taxonomic heterogeneity within Propionibacterium acnes: proposal for Propionibacterium acnes subsp. acnes subsp. nov. and Propionibacterium acnes subsp. elongatum subsp. nov.
abstract: Propionibacterium acnes subsp. acnes subsp. nov. and Propionibacterium acnes subsp. elongatum subsp. nov. are described. These emanate from the three known phylotypes of P. acnes, designated types I, II and III. Electron microscopy confirmed the filamentous cell shape of type III, showing a striking difference from types I/II, which were short rods. Biochemical tests indicated that, in types I/II, either the pyruvate, l-pyrrolidonyl arylamidase or d-ribose 2 test was positive, whereas all of these were negative among type III strains. Matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) spectra, which profile mainly their ribosomal proteins, were different between these two groups. Surface-enhanced laser-desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) spectra of all phylotypes revealed a specific protein biomarker that was overexpressed in type III strains compared with types I/II only when grown aerobically. Reference strains had high whole-genome similarity between types I (>91 %) and II (>75 %), but a considerably lower level of 72 % similarity with type III. recA and gyrB sequence dendrograms confirmed the distant relatedness of type III, indicating the presence of two distinct centres of variation within the species P. acnes. On the other hand, cellular fatty acid profiles and 16S rRNA gene sequence relatedness (>99.3 %) circumscribed the species. Thus, we propose two subspecies, Propionibacterium acnes subsp. acnes subsp. nov. for types I/II and Propionibacterium acnes subsp. elongatum subsp. nov. for type III. The type strain of Propionibacterium acnes subsp. acnes is NCTC 737T ( = ATCC 6919T = JCM 6425T = DSM 1897T = CCUG 1794T), while the type strain of Propionibacterium acnes subsp. elongatum is K124T ( = NCTC 13655T = JCM 18919T).
authors.affiliation: Microbe Division/Japan Collection of Microorganisms, RIKEN BioResource Center, Tsukuba, Japan.|Proteomics Research Unit, Culture Collections, Public Health England, Colindale, London, UK.|Department of Dermatology, Medical Centre East, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Itaru
authors.initials: I
authors.lastname: Dekio
authors.affiliation: Proteomics Research Unit, Culture Collections, Public Health England, Colindale, London, UK.
authors.forename: Renata
authors.initials: R
authors.lastname: Culak
authors.affiliation: Genomic Research Unit, Public Health England, Colindale, London, UK.
authors.forename: Raju
authors.initials: R
authors.lastname: Misra
authors.affiliation: Proteomics Research Unit, Culture Collections, Public Health England, Colindale, London, UK.
authors.forename: Tom
authors.initials: T
authors.lastname: Gaulton
authors.affiliation: Proteomics Research Unit, Culture Collections, Public Health England, Colindale, London, UK.
authors.forename: Min
authors.initials: M
authors.lastname: Fang
authors.affiliation: Microbe Division/Japan Collection of Microorganisms, RIKEN BioResource Center, Tsukuba, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Sakamoto
authors.affiliation: Microbe Division/Japan Collection of Microorganisms, RIKEN BioResource Center, Tsukuba, Japan.
authors.forename: Moriya
authors.initials: M
authors.lastname: Ohkuma
authors.affiliation: Hattori Lab, The University of Tokyo Kashiwa Campus, Kashiwa, Japan.
authors.forename: Kenshiro
authors.initials: K
authors.lastname: Oshima
authors.affiliation: Hattori Lab, The University of Tokyo Kashiwa Campus, Kashiwa, Japan.
authors.forename: Masahira
authors.initials: M
authors.lastname: Hattori
authors.affiliation: School of Biology, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Klenk
authors.affiliation: Genomic Services Unit, Public Health England, Colindale, London, UK.
authors.forename: Dunstan
authors.initials: D
authors.lastname: Rajendram
authors.affiliation: Genomic Research Unit, Public Health England, Colindale, London, UK.
authors.forename: Saheer E
authors.initials: SE
authors.lastname: Gharbia
authors.affiliation: Proteomics Research Unit, Culture Collections, Public Health England, Colindale, London, UK.
authors.forename: Haroun N
authors.initials: HN
authors.lastname: Shah
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000235:genetics; D005227:Fatty Acids / Q000737:chemistry; D005798:Genes, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D011425:Propionibacterium acnes / Q000145:classification*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012269:Ribosomal Proteins / Q000737:chemistry; D017422:Sequence Analysis, DNA; D012867:Skin / Q000382:microbiology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S; D012269:Ribosomal Proteins