Description of Anaerococcus kampingiae sp. nov., Anaerococcus groningensis sp. nov., Anaerococcus martiniensis sp. nov., and Anaerococcus cruorum sp. nov., isolated from human clinical specimens

To improve the identification of anaerobic bacteria, the identity of clinical isolates which could not be identified using MALDI-TOF MS was assessed using whole genome sequencing (WGS) and in-house made main spectral profiles (MSPs) were created. Four novel Anaerococcus species, each represented by at least two isolates, were encountered. The novelty of the isolates was confirmed by comparing the 16S rRNA gene sequences and the WGS with their closest relatives. Phylogenetic and phylogenomic relationships were determined using MEGA X and DSMZ TYGS. Biochemical features were determined and the clustering of the created MSPs was calculated. Possible clinical relevance was assessed. The novelty of the four different species was confirmed by the ANI value, and phylogenetic/phylogenomic clustering. Three of these species shared the same biochemical features, while one showed a different pattern. Only this latter species can be differentiated from other Anaerococcus spp. Remarkebly, six of the ten isolates were obtained from a positive blood culture, of which in five cases the bacterium was the only species encountered. We propose to name these novel species: Anaerococcus kampingiae (ENR0874T = DSM 117234T, CCUG 77487T (accession numbers PP192775/JBGMEF000000000)), Anaerococcus groningensis (ENR1011T = DSM 117232T, CCUG 77488T (accession numbers PP192777/JBGMEG000000000)), Anaerococcus martiniensis (ENR0831T = DSM 117233T, CCUG 77486T (accession numbers PP192776/JBGMEI000000000)), and Anaerococcus cruorum (ENR1039T = DSM 117235T, CCUG 77489T (accession numbers PP192778/JBGMEH000000000)). •Description of four novel Anaerococcus species.•Differentiation between species possible using MALDI-TOF MS and WGS techniques.•7/10 novel Anaerococcus isolates were isolated from positive blood cultures.•The clinical relevance of Anaerococcus species is underestimated.