Comprehensive lipidomic analysis of the genus Cutibacterium.

Cutibacterium are part of the human skin microbiota and are opportunistic microorganisms that become pathogenic in immunodeficient states. These lipophilic bacteria willingly inhabit areas of the skin where sebaceous glands are abundant; hence, there is a need to thoroughly understand their metabolism. Lipids are no longer considered only structural elements but also serve as signaling molecules and may have antigenic properties. Lipidomics remains a major research challenge, mainly due to the diverse physicochemical properties of lipids. Therefore, this study aimed to perform a large comparative lipidomic analysis of eight representatives of the Cutibacterium genus, including four phylotypes of C. acnes and two strains of C. granulosum, C. avidum, and C. namnetense. Lipidomic analysis was performed by liquid chromatography‒mass spectrometry (LC-MS) in both positive and negative ion modes, allowing the detection of the widest range of metabolites. Fatty acid analysis by gas chromatography‒mass spectrometry (GC-MS) corroborated the lipidomic data. As a result, 128 lipids were identified, among which it was possible to select marker compounds, some of which were characteristic even of individual C. acnes phylotypes. These include phosphatidylcholine PC 30:0, sphingomyelins (SM 33:1, SM 35:1), and phosphatidylglycerol with an alkyl ether substituent PG O-32:0. Moreover, cardiolipins and fatty acid amides were identified in Cutibacterium spp. for the first time. This comparative characterization of the cutibacterial lipidome with the search for specific molecular markers reveals its diagnostic potential for clinical microbiology. IMPORTANCE: Cutibacterium (previously Propionibacterium) represents an important part of the human skin microbiota, and its role in clinical microbiology is growing due to opportunistic infections. Lipidomics, apart from protein profiling, has the potential to prove to be a useful tool for defining the cellular fingerprint, allowing for precise differentiation of microorganisms. In this work, we presented a comparative analysis of lipids found in eight strains of the genus Cutibacterium, including a few C. acnes phylotypes. Our results are one of the first large-scale comprehensive studies regarding the bacterial lipidome, which also enabled the selection of C. acnes phylotype-specific lipid markers. The increased role of lipids not only as structural components but also as diagnostic markers or potential antigens has led to new lipid markers that can be used as diagnostic tools for clinical microbiology. We believe that the findings in our paper will appeal to a wide range of researchers.

Episymbiotic Saccharibacteria suppresses gingival inflammation and bone loss in mice through host bacterial modulation.

Saccharibacteria (TM7) are obligate epibionts living on the surface of their host bacteria and are strongly correlated with dysbiotic microbiomes during periodontitis and other inflammatory diseases, suggesting they are putative pathogens. However, due to the recalcitrance of TM7 cultivation, causal research to investigate their role in inflammatory diseases is lacking. Here, we isolated multiple TM7 species on their host bacteria from periodontitis patients. These TM7 species reduce inflammation and consequential bone loss by modulating host bacterial pathogenicity in a mouse ligature-induced periodontitis model. Two host bacterial functions involved in collagen binding and utilization of eukaryotic sialic acid are required for inducing bone loss and are altered by TM7 association. This TM7-mediated downregulation of host bacterial pathogenicity is shown for multiple TM7/host bacteria pairs, suggesting that, in contrast to their suspected pathogenic role, TM7 could protect mammalian hosts from inflammatory damage induced by their host bacteria.

Dynamics of skin microbiota in shoulder surgery infections.

Post-surgical infections arise due to various contributing factors. Most important is the presence of potential pathogenic microorganisms in the skin complemented by the patient´s health status. Cutibacterium acnes is commonly present in the pilosebaceous glands and hair follicle funnels in human skin. After surgical intervention, these highly prevalent, slow-growing bacteria can be found in the deeper tissues and in proximity of implants. C. acnes is frequently implicated in post-surgical infections, often resulting in the need for revision surgery. This review summarizes the current understanding of microbial dynamics in shoulder surgical infections. In particular, we shed light on the contribution of C. acnes to post-surgical shoulder infections as well as their colonization and immune-modulatory potential. Despite being persistently found in post-surgical tissues, C. acnes is often underestimated as a causative organism due to its slow growth and the inefficient detection methods. We discuss the role of the skin environment constituted by microbial composition and host cellular status in influencing C. acnes recolonization potential. Future mapping of the individual skin microbiome in shoulder surgery patients using advanced molecular methods would be a useful approach for determining the risk of post-operative infections.

Unravelling the eco-specificity and pathophysiological properties of Cutibacterium species in the light of recent taxonomic changes.

In 2016, a new species name Cutibacterium acnes was coined for the well-documented species, Propionibacterium acnes, one of the most successful and clinically important skin commensals. The nomenclatural changes were brought about through creation of the genus Cutibacterium, when a group of propionibacteria isolates from the skin were transferred from the genus Propionibacterium and placed in the phylum Actinobacteria. Almost simultaneously, the discovery of two novel species of Cutibacterium occurred and the proposal of three subspecies of C. acnes were reported. These dramatic changes that occurred in a long-established taxon made it challenging for the non-specialist to correlate the huge volume of hitherto published work with current findings. In this review, we aim to correlate the eco-specificity and pathophysiological properties of these newly circumscribed taxa. We envisage that this information will shed light on the pathogenic potential of new isolates and enable better assessment of their clinical importance in the foreseeable future. Currently, five species are recognized within the genus: Cutibacterium acnes, Cutibacterium avidum, Cutibacterium granulosum, Cutibacterium modestum (previously, "Propionibacterium humerusii"), and Cutibacterium namnetense. These reside in different niches reflecting their uniqueness in their genetic makeup. Their pathogenicity includes acne inflammation, sarcoidosis, progressive macular hypomelanosis, prostate cancer, and infections (bone, lumbar disc, and heart). This is also the case for the three newly described subspecies of C. acnes, which are C. acnes subspecies acnes (C. acnes type I), subspecies defendens (C. acnes type II), and subspecies elongatum (C. acnes type III). C. acnes subspecies acnes is related to inflamed acne and sarcoidosis, while subspecies defendens to prostate cancer and subspecies elongatum to progressive macular hypomelanosis. Because the current nomenclature is based upon polyphasic analyses of the biochemical and pathogenic characteristics and comparative genomics, it provides a sound basis studying the pathophysiological roles of these species.

Prevalence and Outcomes of Unexpected Positive Intraoperative Cultures in Presumed Aseptic Revision Hip Arthroplasty.

BACKGROUND: The prevalence and outcomes of unexpected positive cultures (UPCs) of specimens taken during presumed aseptic revision total hip arthroplasty (THA) are unclear. The purpose of this study was to determine the prevalence of UPC and infection-free implant survival in this patient population. Secondary aims included identifying factors associated with subsequent infection-related failure in patients with UPC. METHODS: We reviewed all THA revisions (n = 2,288) performed at our institution from 2006 to 2019. Presumed aseptic revision THAs with intraoperative culture(s) were eligible (n = 1,196), and those with UPC were included in a Kaplan-Meier analysis to determine the infection-free implant survival and in Cox regression analysis to identify factors associated with infection-related failure. RESULTS: UPC(s) were documented for 9.2% (110) of 1,196 aseptic THA revisions. The 2- and 5-year infection-free implant survival in the entire UPC cohort was 93.1% (95% confidence interval [CI] = 90.5% to 95.7%) and 86.8% (95% CI = 82.9% to 90.7%), respectively. The 2- and 5-year infection-free survival with failure due to infection with the same microorganism as identified in the UPC as the end point was 95.8% (95% CI = 93.7% to 97.9%) and 94.3% (95% CI = 91.7% to 96.9%), respectively. Subsequent infection-related failures caused by the same microorganism as identified in the UPC were more likely to occur after revisions with ≥2 UPCs than after those with 1 UPC (p = 0.024). Revision due to adverse metal reaction was a risk factor for subsequent infection-related failure (hazard ratio [HR] = 14.49, 95% CI = 2.69 to 78.04). Patients with a single UPC who were not treated with antibiotics had no subsequent periprosthetic joint infections (PJIs) caused by the same microorganism as identified in the UPC. CONCLUSIONS: The prevalence of UPC was 9.2%, and the infection-free implant survival in patients with UPC is encouraging. Implant survival free of PJI caused by the same microorganism as identified in the UPC was excellent. Aseptic revision for adverse metal reaction was a risk factor for subsequent PJI in patients with UPC. No patient with a single UPC who was not treated with antibiotics developed PJI caused by the UPC-identified microorganism, suggesting that in the absence of other signs of infection a single UPC does not warrant antibiotic treatment. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Brevilactibacter coleopterorum sp. nov., isolated from the intestine of the dark diving beetle Hydrophilus acuminatus, and Weissella coleopterorum sp. nov., isolated from the intestine of the diving beetle Cybister lewisianus.

A polyphasic taxonomic approach was used to characterize two novel bacterial strains, designated as HDW11T and HDW19T, isolated from intestine samples of the dark diving beetle Hydrophilus acuminatus and the diving beetle Cybister lewisianus, respectively. Both isolates were Gram-stain-positive, facultatively anaerobic and non-motile. Strain HDW11T grew optimally at 30 °C, pH 8 and in the presence of 1% (w/v) NaCl. Strain HDW19T grew optimally at 25 °C, pH 7 and in the presence of 0.3% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences and genome sequences revealed that strain HDW11T is a member of the genus Brevilactibacter and is closely related to Brevilactibacter flavus VG341T [with 97.9% 16S rRNA sequence identity and 79.1% average nucleotide identity (ANI)], and that strain HDW19T belongs to the genus Weissella and is closely related to W. koreensis KCTC 3621T (with 98.9% 16S rRNA sequence identity and 79.5% ANI). The major cellular fatty acids of strains HDW11T and HDW19T were C18:1 ω9c and anteiso-C15:0, respectively. The sole respiratory quinone of strain HDW11T was MK-9 (H4). The major polar lipid components of strain HDW11T were diphosphatidylglycerol and phosphatidylglycerol, and the major polar lipid component of strain HDW19T was diphosphatidylglycerol. The genomic DNA G+C content of strains HDW11T and HDW19T were 72.1 and 37.2 mol%, respectively. The results of phylogenetic, phenotypic, chemotaxonomic and genotypic analyses suggest that strain HDW11T represents a novel species within the genus Brevilactibacter, and that strain HDW19T represents a novel species within the genus Weissella. We propose the name Brevilactibacter coleopterorum sp. nov. for strain HDW11T (=KACC 21335T=KCTC 49320T=JCM 33680T) and the name Weissella coleopterorum for strain HDW19T (=KACC 21347T=KCTC 43114T=JCM 33684T).

Bacterial pericarditis and empyema caused by Cutibacterium acnes in a patient with metastatic lung cancer.

Bacterial pericarditis and empyema due to Cutibacterium acnes has rarely been reported. C.acnes, a normal component of human skin flora, is often considered a contaminant when isolated from body fluids and thus cases may be underreported. We report the first case of concurrent purulent pericarditis and empyema caused by C. acnes in a patient with newly diagnosed metastatic lung cancer. Our patient underwent pericardial window creation and placement of pericardial and bilateral chest tubes and was successfully treated with culture directed antibiotic therapy.

Aestuariimicrobium ganziense sp. nov., a new Gram-positive bacterium isolated from soil in the Ganzi Tibetan autonomous prefecture, China.

A novel Gram-stain positive, oval-shaped, and non-flagellated bacterium, designated YIM S02566T, was isolated from alpine soil in Shadui Towns, Ganzi County, Ganzi Tibetan Autonomous Prefecture, Sichuan Province, PR China. Growth occurred at 23-35 °C (optimum, 30 °C) in the presence of 0.5-4% (w/v) NaCl (optimum, 1%) and at pH 7.0-8.0 (optimum, pH 7.0). The phylogenetic analysis based on 16S rRNA gene sequence revealed that strain YIM S02566T was most closely related to the genus Aestuariimicrobium, with Aestuariimicrobium kwangyangense R27T and Aestuariimicrobium soli D6T as its closest relative (sequence similarities were 96.3% and 95.4%, respectively). YIM S02566T contained LL-diaminopimelic acid in the cell wall. MK-9(H4) was the predominant menaquinone. The major fatty acid patterns were anteiso-C15:0 (60.0%). The major polar lipid was DPG. The genome size of strain YIM S02566T was 3.1 Mb, comprising 3078 predicted genes with a DNA G + C content of 69.0 mol%. Based on these genotypic, chemotaxonomic and phenotypic evidences, strain YIM S02566T was identified as a novel species in the genus Aestuariimicrobium, for which the name Aestuariimicrobium ganziense sp. nov. is proposed. The type strain is YIM S02566T (= CGMCC 1.18751 T = KCTC 49,477 T).

Improvement of polyhydroxybutyrate (PHB) plate-based screening method for PHB degrading bacteria using cell-grown amorphous PHB and recovered by sodium dodecyl sulfate (SDS).

Poly(3-hydroxybutyrate) (PHB) is a biobased and biodegradable plastic. Considering the environmental issues of petroleum-based plastics, PHB is promising as it can be degraded in a relatively short time by bacteria to water and carbon dioxide. Substantial efforts have been made to identify PHB-degrading bacteria. To identify PHB-degrading bacteria, solid-based growth or clear zone assays using PHB as the sole carbon source are the easiest methods; however, PHB is difficult to dissolve and distribute evenly, and bacteria grow slowly on PHB plates. Here, we suggest an improved PHB plate assay using cell-grown PHB produced by Halomonas sp. and recovered by sodium dodecyl sulfate (SDS). Preparation using SDS resulted in evenly distributed PHB plates that could be used for sensitive depolymerase activity screening in less time compared with solvent-melted pellet or cell-grown PHB. With this method, we identified 15 new strains. One strain, Cutibacterium sp. SOL05 (98.4% 16S rRNA similarity to Cutibacterium acne), showed high PHB depolymerase activity in solid and liquid conditions. PHB degradation was confirmed by clear zone size, liquid culture, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The results indicate this method can be used to easily identify PHB-degrading bacteria from various sources to strengthen the benefits of bioplastics.

Regulatory effects of Lactobacillus plantarum-GMNL6 on human skin health by improving skin microbiome.

Bacteria response to their environment by producing some compounds which are used in cosmetic and pharmaceutical applications. Some probiotics can regulate immune response and modulate the symptoms of several diseases. Bacteria affect skin response to skin care products. Bacteria are thought to play an important role in acne incidence, skin moisture, and nutrient metabolism, but only a few studies have focused on the extracts of Lactobacillus plantarum in skin care. In this study, we identified that L. plantarum-GMNL6 enhanced collagen synthesis and the gene expression of serine palmitoyltransferase small subunit A. Meanwhile, L. plantarum-GMNL6 reduced the melanin synthesis, the biofilm of Staphylococcus aureus, and the proliferation of Cutibacterium acnes. Information from clinical observation during the ointment for external face use in people displayed that the syndromes of skin moisture, skin color, spots, wrinkles, UV spots, and porphyrins were improved. The diversification of human skin microbiomes was affected by smearing the face of volunteers with L. plantarum-GMNL6. Understanding the potential mechanisms of the action of L. plantarum-GMNL6 in dermatologic conditions promotes the development of care products.

Characterization of the human skin resistome and identification of two microbiota cutotypes.

BACKGROUND: The human skin microbiota is considered to be essential for skin homeostasis and barrier function. Comprehensive analyses of its function would substantially benefit from a catalog of reference genes derived from metagenomic sequencing. The existing catalog for the human skin microbiome is based on samples from limited individuals from a single cohort on reference genomes, which limits the coverage of global skin microbiome diversity. RESULTS: In the present study, we have used shotgun metagenomics to newly sequence 822 skin samples from Han Chinese, which were subsequently combined with 538 previously sequenced North American samples to construct an integrated Human Skin Microbial Gene Catalog (iHSMGC). The iHSMGC comprised 10,930,638 genes with the detection of 4,879,024 new genes. Characterization of the human skin resistome based on iHSMGC confirmed that skin commensals, such as Staphylococcus spp, are an important reservoir of antibiotic resistance genes (ARGs). Further analyses of skin microbial ARGs detected microbe-specific and skin site-specific ARG signatures. Of note, the abundance of ARGs was significantly higher in Chinese than Americans, while multidrug-resistant bacteria ("superbugs") existed on the skin of both Americans and Chinese. A detailed analysis of microbial signatures identified Moraxella osloensis as a species specific for Chinese skin. Importantly, Moraxella osloensis proved to be a signature species for one of two robust patterns of microbial networks present on Chinese skin, with Cutibacterium acnes indicating the second one. Each of such "cutotypes" was associated with distinct patterns of data-driven marker genes, functional modules, and host skin properties. The two cutotypes markedly differed in functional modules related to their metabolic characteristics, indicating that host-dependent trophic chains might underlie their development. CONCLUSIONS: The development of the iHSMGC will facilitate further studies on the human skin microbiome. In the present study, it was used to further characterize the human skin resistome. It also allowed to discover the existence of two cutotypes on the human skin. The latter finding will contribute to a better understanding of the interpersonal complexity of the skin microbiome. Video abstract.

Time-dependent bacterial air contamination of sterile fields in a controlled operating room environment: an experimental intervention study.

BACKGROUND: Surgical site infections are a global patient safety concern. Due to lack of evidence on contamination, pre-set surgical goods are sometimes disposed of or re-sterilized, thus increasing costs, resource use, and environmental effects. AIM: To investigate time-dependent bacterial air contamination of covered and uncovered sterile goods in the operating room. METHODS: Blood agar plates (N = 1584) were used to detect bacterial air contamination of sterile fields on 48 occasions. Each time, three aerobe and three anaerobe plates were used as baseline to model the preparation time, and 60 (30 aerobe, 30 anaerobe) were used to model the time pending before operation; half of these were covered with sterile drapes and half remained uncovered. Plates were collected after 4, 8, 12, 16, and 24 h. FINDINGS: Mean time before contamination was 2.8 h (95% confidence interval: 2.1-3.4) in the uncovered group and 3.8 h (3.2-4.4) in the covered group (P = 0.005). The uncovered group had 98 colony-forming units (cfu) versus 20 in the covered group (P = 0.0001). Sixteen different micro-organisms were isolated, the most common being Cutibacterium acnes followed by Micrococcus luteus. Of 32 Staphylococcus cfu, 14 were antibiotic resistant, including one multidrug-resistant Staphylococcus epidermidis. CONCLUSION: Protecting sterile fields from bacterial air contamination with sterile covers enhances the durability of sterile goods up to 24 h. Prolonged durability of sterile goods might benefit patient safety, since surgical sterile material could be prepared in advance for acute surgery, thereby enhancing quality of care and reducing both climate impact and costs.

Reproducing the scalp microbiota community: co-colonization of a 3D reconstructed human epidermis with C. acnes and M. restricta.

OBJECTIVE: A 3D reconstructed human epidermis (RHE) model colonized with specific microbial strains was developed to model the complex interactions between strains of the human scalp hair. METHODS: Reconstructed human epidermis was colonized with Cutibacterium acnes and Malassezia restricta for 72 h. The epidermal model was characterized in terms of morphology, using immune-labelling targeting biomarkers for barrier structure, proliferation, differentiation and anti-microbial defence. The barrier function was assessed by transepithelial electrical eesistance (TEER) measurements. In order to study the microorganisms on the epidermal model, viable counts and phenotype ultrastructure analysis were performed by scanning electron microscopy (SEM). RESULTS: The RHE colonized with C. acnes did not lead to severe modifications of the physiological barrier integrity and viability, though it shows aggregates. M. restricta formed large aggregates by a close interaction with the RHE, thus causing both a strong decrease in barrier function and structure degradation and an increased human beta defensin 2 (HBD2) expression. The co-colonized model resulted in barrier depletion, but the overall damage was less severe, respecting the single colonization with M. restricta. The developed 'scalp model' allowed to identify morphological modifications leading to uncontrolled epidermal renewal. CONCLUSION: This study shows a pre-clinical model that recapitulates the interactions that can occur between site-specific microbial strains and keratinocytes in dandruff condition. The model can be applied to assess ingredients and products' mechanism of action.

OBJECTIF: Un modèle d'épiderme humain reconstruit a été colonisé par des souches microbiennes spécifiques du cuir chevelu pour étudier les interactions complexes entre les microorganismes et l'épiderme. MÉTHODES: Les épidermes humains reconstruits ont été colonisés par Cutibacterium acnes et Malassezia restricta pendant 72 h, puis caractérisés morphologiquement et par immunomarquages pour suivre les marqueurs de la différenciation kératinocytaire pour la fonction barrière, de prolifération et de défense antimicrobienne. La fonction barrière a également été évaluée par des mesures de résistance électrique transépithéliale (TEER). Afin d'étudier les microorganismes sur le modèle épidermique, des numérations des microorganismes viables et une analyse de l'ultrastructure phénotypique par microscopie électronique à balayage ont été effectuées. RÉSULTATS: Les modèles colonisés par C. acnes n'ont pas conduit à des modifications conséquentes de l'intégrité et de la viabilité de la barrière physiologique, bien que cette souche forme des agrégats. M. restricta a formé de gros agrégats par une interaction étroite avec l'épiderme, provoquant ainsi à la fois une forte diminution de la fonction barrière, une dégradation de la structure et une augmentation de l'expression de la bêta-défensine 2 humaine. Les modèles co-colonisés ont montré une altération de la fonction barrière, mais les dommages globaux étaient moins drastiques que lors de la simple colonisation par M. restricta. Ce « modèle de cuir chevelu ¼ développé a permis d'identifier des modifications morphologiques conduisant à un renouvellement épidermique incontrôle. CONCLUSION: Cette étude propose un modèle préclinique qui mime les interactions qui peuvent se produire entre les souches microbiennes spécifiques de ce site anatomique et les kératinocytes du scalp en condition pelliculaire. De plus, ce modèle peut être utiliser pour screener ingrédients et produits formulés et ainsi accéder à leurs mécanismes d'action.

Acne in the first three decades of life: An update of a disorder with profound implications for all decades of life.

Acne vulgaris is a chronic, inflammatory, skin condition that involves the pilosebaceous follicles and is influenced by a variety of factors including genetics, androgen-stimulation of sebaceous glands with abnormal keratinization, colonization with Cutibacterium acnes (previously called Propionibacterium acnes), and pathological immune response to inflammation. Acne can occur at all ages and this discussion focuses on the first three decades of life. Conditions that are part of the differential diagnosis and/or are co-morbid with acne vulgaris are also considered. Acne in the first year of life includes neonatal acne (acne neonatorum) that presents in the first four weeks of life and infantile acne that usually presents between 3 and 6 months of the first year of life with a range of 3 to 16 months after birth. Acne rosacea is a chronic, inflammatory, skin condition that is distinct from acne vulgaris, typically presents in adults, and has four main types: erythemato-telangiectatic, papulopustular, phymatous and ocular. Treatment options for acne vulgaris include topical retinoids, topical benzoyl peroxide, antibiotics (topical, oral), oral contraceptive pills, isotretinoin, and others. Management must consider the increasing impact of antibiotic resistance in the 21st century. Psychological impact of acne can be quite severe and treatment of acne includes awareness of the potential emotional toll this disease may bring to the person with acne as well as assiduous attention to known side effects of various anti-acne medications (topical and systemic). Efforts should be directed at preventing acne-caused scars and depigmentation on the skin as well as emotional scars within the person suffering from acne.

Tessaracoccus coleopterorum sp. nov., isolated from the intestine of the dark diving beetle, Hydrophilus acuminatus.

A polyphasic taxonomic approach was used to characterize a novel bacterium, designated as strain HDW20T, isolated from the intestine of the dark diving beetle Hydrophilus acuminatus. The isolate was Gram-stain-positive, facultatively anaerobic, non-motile, coccus-shaped, and formed pale orange colonies. Phylogenetic analysis based on 16S rRNA gene sequences and genome sequences showed that the isolate belonged to the genus Tessaracoccus in the phylum Actinobacteria and was closely related to T. flavescens SST-39T, T. defluvii JCM 17540T, and T. aquimaris NSG39T, with the highest 16S rRNA gene sequence similarity of 98.5 % and a highest average nucleotide identity (ANI) value of 80.6 %. The major cellular fatty acids were C18 : 1 ω9c and anteiso-C15 : 0. The main respiratory quinone was MK-9 (H4). The major polar lipid components were phosphatidylglycerol and diphosphatidylglycerol. The genomic DNA G+C content was 69.0 %. The isolate contains ʟʟ-diaminopimelic acid, ʟ-alanine, and ʟ-lysine as amino acid components, and ribose, glucose, and galactose as sugar components of the cell wall peptidoglycan. The results of phylogenetic, phenotypic, chemotaxonomic, and genotypic analyses suggested that strain HDW20T represents a novel species within the genus Tessaracoccus. We propose the name Tessaracoccus coleopterorum sp. nov. The type strain is HDW20T (=KACC 21348T=KCTC 49324T=JCM 33674T).

Low prevalence of Cutibacterium acnes in prostatic tissue biopsies in a French hospital.

We evaluated the Cutibacterium acnes prevalence in prostatic biopsies and characterized the strains at a molecular level. 18 out of 36 biopsies (50%) were sterile after seven days in culture. C. acnes was observed in only two biopsies. Its prevalence was low (5.6%). Finally, the molecular characterization revealed diverse clusters including phylotypes IA1, IB and II.

Microlunatus elymi sp. nov., a novel actinobacterium isolated from rhizospheric soil of the wild plant Elymus tsukushiensis.

An actinobacterial strain, designated KUDC0627T, was isolated from rhizospheric soil that contained Elymus tsukushiensis on the Dokdo Islands, Republic of Korea. Cells were Gram-stain-positive, facultative anaerobic, non-motile and non-endospore-forming cocci. Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that strain KUDC0627T belongs to the genus Microlunatus and is most closely related to Microlunatus soli DSM 21800T (98.5 %), Microlunatus endophyticus DSM 100019T (97.7 %) and Microlunatus ginsengisoli Gsoil 633T (96.5 %). The average nucleotide identity scores and average amino acid identity values were all below the 95.0 % cut-off point. In silico DNA-DNA hybridization, using the Genome-to-Genome Distance Calculator, estimated that there is 22.3 % DNA relatedness between KUDC0627T and M. soli DSM 21800T. The genomic DNA G+C content was 66.9 mol%. The major menaquinone was MK-9(H4) and the major diagnostic diamino acid in the cell-wall peptidoglycan was ll-diaminopimelic acid. The polar lipid profile included diphosphatidylglycerol, phosphatidylglycerol, unidentified phospholipids, unidentified glycolipids and unidentified lipids. The major cellular fatty acids were iso-C15 : 0, anteiso-C15 : 0 and iso-C16 : 0. Based on phenotypic, chemotaxonomic, and phylogenetic data, strain KUDC0627T (=KCTC 39853T=JCM 32702T) represents a novel species, for which the name Microlunatus elymi sp. nov. is proposed.

Enemella gen. nov., Enemella evansiae sp. nov., Enemella dayhoffiae sp. nov. and Parenemella sanctibonifatiensis gen. nov., sp. nov., novel taxa assignable to the family Propionibacteriaceae and derived from human clinical samples.

Nine Gram-stain-positive cocci, coccobacilli or short, rod-shaped strains recovered from clinical sources from patients located in two Canadian provinces and one environmental source were extensively studied. Clinical sources included blood cultures, cerebral spinal fluid, lymph node, lung biopsy and peritoneal fluid. Through 16S rRNA gene and whole genome sequencing analyses, the strains were found to cluster into three groups, closest to but distinguished from other genera in the family Propionibacteriaceae. The genomes from these bacteria had high G+C content, ranging from 67.8-69.56 mol%, and genome sizes of 3.02-4.52 Mb. Biochemical and chemotaxonomic properties including branched-chain cellular fatty acids, l-lysine diaminopimelic acid (ll-DAP) and cell-wall type A3γ (ll-DAP-gly) containing ll-DAP, alanine, glycine and glutamic acid were found and so the strains were therefore deemed to be consistent with other new genera in this family. Based on this investigation, we propose Enemella gen. nov., Enemella evansiae sp. nov., Enemella dayhoffiae sp. nov. and Parenemella sanctibonifatiensis gen. nov., sp. nov. for these taxa. Misidentified taxon 'Ponticoccus gilvus' was found to be assignable to Enemella evansiae based on this study.