Description of an anaerobic actinobacterium, Kribbibacterium absianum gen. nov., sp. nov., a new member of the novel family Kribbibacteriaceae fam. nov., and reclassification of the genera Granulimonas and Leptogranulimonas.

Two rod-shaped, obligate anaerobic, Gram-stain-positive bacteria isolated from the pig faeces were designated YH-ols2216 and YH-ols2217T. Analysis of 16S rRNA gene sequences revealed that these isolates were most related to the members of the family Atopobiaceae, within the order Coriobacteriales, and Granulimonas faecalis KCTC 25474T with 92.0 and 92.5% similarities, respectively. The 16S rRNA gene sequence similarity within isolates was 99.9 %; and those between isolates YH-ols2216 and YH-ols2217T, and Atopobium minutum DSM 20586T, the type species of the type genus Atopobium within the family Atopobiaceae, were 88.5 and 88.7 %, respectively. Those between isolates and Coriobacterium glomerans PW2T, the type species of the type genus Coriobacterium within the family Coriobacteriaceae, were 88.7 and 89.1 %, respectively. The multi-locus sequence tree revealed that the isolates, alongside the genera Granulimonas and Leptogranulimonas, formed a distinct cluster between the families Atopobiaceae and Coriobacteriaceae. The average nucleotide identities and digital DNA-DNA hybridization values for the isolates and their most closely related strains ranged from 67.7 to 76.2 % and from 18.4 to 23.3 %, respectively. The main cellular fatty acids of the isolates were C18 : 0 DMA, C18 : 1 ω9c, C18 : 0 12OH, C18 : 0, and C16 : 0. The cell wall contained the peptidoglycan meso-diaminopimelic acid. Lactate was the main end-product of the isolates. The major polar lipids of isolate YH-ols2217T were aminophospholipid, aminolipids, and lipids. Menaquinones were not identified in the cells of the isolates. The DNA G+C contents of isolates YH-ols2216 and YH-ols2217T were 67.5 and 67.6 mol%, respectively. Considering these chemotaxonomic, phenotypic, and phylogenetic properties, Kribbibacteriaceae fam. nov. is proposed within the order Coriobacteriales. YH-ols2216 (=KCTC 25708=NBRC 116429) and YH-ols2217T (=KCTC 25709T=NBRC 116430T) represent a novel taxon within this new family and the name Kribbibacterium absianum gen. nov., sp. nov. is proposed. In addition, the genera Granulimonas and Leptogranulimonas are transferred to the family Kribbibacteriaceae fam. nov.

Aerococcus kribbianus sp. nov., a facultatively anaerobic bacterium isolated from pig faeces.

Two cocci-shaped, facultatively anaerobic, Gram-positive bacteria isolated from the faeces of a pig were designated as strains YH-aer221T and YH-aer222. Analysis of the 16S rRNA gene sequences revealed that the isolates were most closely related to Aerococcus suis JCM 18035T with 96.6 % similarity. The multi-locus sequence tree revealed that the isolates formed a sub-cluster adjacent to A. suis JCM 18035T. The average nucleotide identity values for the isolates and their most closely related strains were 71.8 and 71.7 %, respectively; and the digital DNA-DNA hybridization values for the isolates and their most closely related strains were 25.6 and 25.5 %, respectively. The main fatty acids were C18 : 1ω9c, C16 : 0 and C18 : 0. The cell wall contained the meso-diaminopimelic acid-based peptidoglycan. The two isolates shared the same metabolic pathways. Isolates YH-aer221T and YH-aer222 harboured the same CRISPR array with 33 and 46 spacers, respectively. Single-genome vs. metagenome analysis showed that the genomes of the isolates were not found in the available metagenome database. Given their chemotaxonomic, phenotypic and phylogenetic properties, YH-aer221T (= KCTC 25571T=JCM 35699T) and YH-aer222 (=KCTC 25573=JCM 35700) represent a novel taxon. The name Aerococcus kribbianus sp. nov. is proposed.

Description of Fusibacillus kribbianus gen. nov., sp. nov., a fusiform anaerobe isolated from pig feces.

OBJECTIVE: The family Lachnospiraceae is affiliated with the order Clostridiales and was originally contained within Clostridial cluster XIVa. The members of Lachnospiraceae inhabiting the gut comprise the chemoorganotrophic genera, generating sundry short-chain fatty acids to supply energy to the host, and are considered to be related to obesity and gut health. METHODS: The polyphasic taxonomic approach was used to characterize the isolate YH-rum2234T. A detailed metabolic analysis was conducted to compare the novel isolate with related strains within the family Lachnospiraceae. RESULTS: A fusiform, obligately anaerobic, Gram-stain-negative bacterium, YH-rum2234T, was isolated from pig feces. Analysis of the 16S rRNA gene sequence revealed that the similarities between the isolate and the familiarly interrelated strain Lientehia hominis KCTC 25345T was 94.3%. The average nucleotide identities and genome-to-genome distances of YH-rum2234T and its closely related strains were below 85.5% and 32.5%, respectively. The G + C content of the genomic DNA was 49.2 mol%. The main fatty acids were C16:0, C14:0, and C14:0 DMA. The major polar lipids were aminophospholipids. The cell wall did not contain the peptidoglycan meso-diaminopimelic acid. CONCLUSION: Given the chemotaxonomic, phenotypic, and phylogenetic properties, YH-rum2234T (=KCTC 25710T = DSMZ 116041T) represents a new genus and species in the family Lachnospiraceae. Fusibacillus kribbianus gen. nov., sp. nov. is the proposed name.

The novel immunobiotic Clostridium butyricum S-45-5 displays broad-spectrum antiviral activity in vitro and in vivo by inducing immune modulation.

Clostridium butyricum is known as a probiotic butyric acid bacterium that can improve the intestinal environment. In this study, we isolated a new strain of C. butyricum from infant feces and evaluated its physiological characteristics and antiviral efficacy by modulating the innate immune responses in vitro and in vivo. The isolated C. butyricum S-45-5 showed typical characteristics of C. butyricum including bile acid resistance, antibacterial ability, and growth promotion of various lactic acid bacteria. As an antiviral effect, C. butyricum S-45-5 markedly reduced the replication of influenza A virus (PR8), Newcastle Disease Virus (NDV), and Herpes Simplex Virus (HSV) in RAW264.7 cells in vitro. This suppression can be explained by the induction of antiviral state in cells by the induction of antiviral, IFN-related genes and secretion of IFNs and pro-inflammatory cytokines. In vivo, oral administration of C. butyricum S-45-5 exhibited prophylactic effects on BALB/c mice against fatal doses of highly pathogenic mouse-adapted influenza A subtypes (H1N1, H3N2, and H9N2). Before challenge with influenza virus, C. butyricum S-45-5-treated BALB/c mice showed increased levels of IFN-ß, IFN-γ, IL-6, and IL-12 in serum, the small intestine, and bronchoalveolar lavage fluid (BALF), which correlated with observed prophylactic effects. Interestingly, after challenge with influenza virus, C. butyricum S-45-5-treated BALB/c mice showed reduced levels of pro-inflammatory cytokines and relatively higher levels of anti-inflammatory cytokines at day 7 post-infection. Taken together, these findings suggest that C. butyricum S-45-5 plays an antiviral role in vitro and in vivo by inducing an antiviral state and affects immune modulation to alleviate local and systemic inflammatory responses caused by influenza virus infection. Our study provides the beneficial effects of the new C. butyricum S-45-5 with antiviral effects as a probiotic.

Lacticaseibacillus parakribbianus sp. nov., isolated from a pig farm faeces dump.

A lactic acid bacterium isolated from pig faeces was characterized using a polyphasic approach. The strain was Gram-stain-positive, rod-shaped, and facultative anaerobic. Phylogenetic analysis of the 16S rRNA gene sequence indicated that the isolate belonged to the genus Lacticaseibacillus. The multi-locus sequence tree revealed that the strain formed a sub-cluster adjacent to Lacticaseibacillus kribbianus. The main fatty acids were C16 : 0 and C18 : 1ω9c. The average nucleotide identity value, average amino acid identity, and genome-to-genome distance for YH-lacS6T and its most closely related strain, L. kribbianus, were 85.4, 85.2 and 29.2 %, respectively. The G+C content of the genomic DNA was 61.6 mol%. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, aminophospholipids and phospholipids. The cell-wall peptidoglycan did not contain meso-diaminopimelic acid. Thus, YH-lacS6T (=KCTC 21186T=JCM 34954T) represents a novel species. The name Lacticaseibacillus parakribbianus sp. nov. is proposed.

Faecalicatena absiana sp. nov., an obligately anaerobic bacterium from a pig farm faeces dump.

An obligately anaerobic, Gram-stain-positive, spore-forming, short-rod-shaped bacterium, designated strain YH-C36aT, was isolated from a pig farm faeces dump. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the genus Faecalicatena and is most closely related to Faecalicatena contorta KCTC 5831T, Faecalicatena fissicatena KCTC 15010T and Faecalicatena orotica KCTC 15331T, with 96.3, 96.2, and 96.0 % sequence similarity, respectively. The average nucleotide identity values for strain YH-C36aT and the closest related strains were lower than 72 %. The G+C content of the isolate was 43.0 mol%. The cell-wall peptidoglycan was A1γ type and contained meso-diaminopimelic acid. The predominant fatty acids were C16 : 0, C18 : 1 cis 9, C16 : 0 DMA, C18 : 0 DMA and C18:0. The major end products of glucose fermentation were lactate, formate and acetate. Based on its phenotypic, phylogenetic and chemotaxonomic properties, a novel species, named Faecalicatena absiana sp. nov., is proposed for strain YH-C36aT (=KCTC 25106T=NBRC 114768T).

Lacticaseibacillus kribbianus sp. nov., isolated from pig farm faeces dump.

A lactic acid bacteria isolated from pig faeces was characterized using a polyphasic approach. Cells of the strain were Gram-stain-positive, rod-shaped and facultative anaerobic. Phylogenetic analysis of 16S rRNA gene sequence indicated that the isolate belonged to the genus Lacticaseibacillus; however, the similarity to other homologues within the genus was <98 %. Analysis of housekeeping gene sequences (pheS and recA) revealed that the strain formed a sub-cluster adjacent to Lacticaseibacillus absianus and Lacticaseibacillus daqingensis. The main fatty acids of the strain is the C18 : 1ω9c and C16 : 0. The G+C content of the genomic DNA was 62.8 mol %. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, aminophospholipids and phospholipids. The cell-wall peptidoglycan did not contain meso-diaminopimelic acid. Thus, YH-lac21T (=KCTC 21185=JCM 34953) represents a novel species. The name Lacticaseibacillus kribbianus sp. nov. is proposed.

Antimicrobial activity of ClO2 gas against Salmonella Enteritidis on almonds.

Nuts, including almonds, are occasionally contaminated with Salmonella spp. In this study, we used chlorine dioxide (ClO2) gas to inactivate S. enterica subsp. Enterica serovar Enteritidis on almonds. Almonds inoculated with a single strain of S. Enteritidis (8.95 log cfu/mL) were exposed to ClO2 gas generated from 1.0 or 1.5 mL ClO2 solution in a sealed container at 50 or 60 °C (43% relative humidity) for up to 10 h. The concentration of ClO2 gas peaked at 354-510 and 750-786 ppm within 0.5 h upon deposition of 1.0 and 1.5 mL of aqueous ClO2, respectively, and gradually decreased thereafter. Population of S. Enteritidis on almonds treated at 50 °C decreased to 1.70-2.32 log cfu/sample within 1 h of exposure to ClO2 gas and decreased to below the detection limit (1.7 log cfu/sample) at all ClO2 concentrations after 8 h. At 60 °C, the microbial population fell below the detection limit within 1 h, regardless of the volume of ClO2 solution supplied. Microbial survival on almonds treated with ClO2 gas and stored at 12 or 25 °C was observed for up to 8 weeks and the organism was not recovered from the almonds treated for 10 h and stored at 12 °C for 2-8 weeks. The lightness (L value) and redness (a value) of almonds treated for 10 h were not changed by ClO2 gas treatment, but yellowness (b value) increased. Results showed that Salmonella on almonds was successfully inactivated by ClO2 gas treatment and the microbial survival did not occur during storage.

Lentilactobacillus kribbianus sp. nov., isolated from the small intestine of a mini pig.

A Gram-stain-positive, facultative anaerobic, rod-shaped bacteria isolated from the small intestine of a mini pig was designated as strain YH-lac9T. 16S rRNA gene sequence analysis revealed that the strain belongs to the genus Lentilactobacillus and is closely related to Lentilactobacillus senioris JCM 17472T, Lentilactobacillus rapi JCM 15042T and Lentilactobacillus diolivorans JCM 13927T, with 97.6, 96.2 and 95.7 % sequence similarity, respectively. Analysis of housekeeping gene sequences (pheS and recA) revealed that the strain formed a sub-cluster with L. senioris, supporting the results of 16S rRNA gene sequences analysis. The average nucleotide identity value for YH-lac9T and the most closely related strain is 74.1 %. The main fatty acids are C18 : 1ω9c, summed feature 7, C16 : 0 and summed feature 8. The G+C content of the genomic DNA is 37.8 mol%. In view of its chemotaxonomic, phenotypic and phylogenetic properties, YH-lac9T (=KCTC 25005=JCM 33997) represents a novel taxon. The name Lentilactobacillus kribbianus sp. nov. is proposed.

Correction to: Genome-Based Reclassification of Fusobacterium nucleatum Subspecies at the Species Level.

The original version of this article contained errors in the description of novel species. These errors are corrected with this corrigendum.

Paenibacillus oralis sp. nov., Isolated from Human Subgingival Dental Plaque of Gingivitis Lesion.

A Gram-stain-negative, facultative anaerobic, spore-forming, motile, and rod-shaped bacterium, strain ChDC PVNT-B20T, was isolated from the human subgingival dental plaque of a gingivitis lesion. Phylogenetic analysis based on the 16S ribosomal RNA gene (16S rDNA) showed that the strain belonged to the genus Paenibacillus. BLAST analysis of 16S rDNA sequence of the strain displayed high identity to those of Paenibacillus faecis DSM 23593T (97.7% similarity) and Paenibacillus macerans ATCC 8244T (97.6% similarity). Draft genome of strain ChDC PVNT-B20T was composed of 8,112,407 bp. The DNA G+C content of the strain was 51.3 mol%. Average nucleotide identity values between strain ChDC PVNT-B20T and P. faecis DSM 23593T or P. macerans ATCC 8244T were 75.71% and 91.5%, respectively. Genome-to-genome distance values between strain ChDC PVNT-B20T and P. faecis DSM 23593T or P. macerans ATCC 8244T were 21.6% (19.3-24.0%) and 44.9% (42.3-47.4%), respectively. Major cellular fatty acids of strain ChDC PVNT-B20T were anteiso-C15:0 (43.4%), C16:0 (16.6%), iso-C16:0 (14.4%), and anteiso-C17:0 (12.4%). The sole respiratory quinone of the strain was menaqinone-7. Major polar lipids of the strain were phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), and one unidentified glycolipid (GL). Minor polar lipids were one unidentified aminolipid (AL), one unidentified phospholipid (PL), and three unidentified lipids (L1-L3). Based on these results, strain ChDC PVNT-B20T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus oralis sp. nov. is proposed. Type strain is ChDC PVNT-B20T (= KCOM 3021T = JCM 33462 T).

Absicoccus porci gen. nov., sp. nov., a member of the family Erysipelotrichaceae isolated from pig faeces.

An obligately anaerobic, Gram-stain-positive and coccus-shaped bacterium, designated strain YH-panp20T, was isolated from pig faeces. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the isolate belongs to the family Erysipelotrichaceae, and is most closely related to Catenisphaera adipataccumulans KCTC 15517T (93.5 % sequence similarity), followed by Faecalitalea cylindroides KCTC 5815T (92.2 %), Faecalicoccus acidiformans KCTC 15521T (90.2 %) and Holdemanella biformis KCTC 5969T (89.6 %). Average nucleotide identity values between YH-panp20T and its closest relatives were lower than 71 %. The G+C content of the isolate was 38.4 mol%, and its cell-wall peptidoglycan was found to be of A1γ type and contained meso-diaminopimelic acid. The predominant fatty acids were C18 : 1 cis 9, C18 : 0 DMA and C16 : 0. The major end-products of glucose fermentation were lactate, acetate and formate. Therefore, based on the phenotypic, phylogenetic and chemotaxonomic properties, a novel genus and species, Absicoccus porci gen. nov., sp. nov., is proposed for isolate YH-panp20T (=KCTC 15747T=JCM 32769T).

Streptococcus koreensis sp. nov., Isolated from Human Subgingival Dental Plaque of Periodontitis Lesion.

A novel facultative anaerobic, Gram-stain-positive coccus, strain JS71T, was isolated from the human subgingival dental plaque of a periodontitis lesion. Phylogenetic analysis based on the 16S ribosomal RNA gene (16S rDNA) revealed that the strain belonged to the genus Streptococcus. The 16S rDNA sequence had high similarity with Streptococcus rubneri DSM 26920T (98.6%), Streptococcus parasanguinis ATCC 15912T (98.5%), and Streptococcus australis CCUG 45919T (98.3%). The genome of strain JS71T was 2,009,592 bp in length. The DNA G+C content of the strain was 42.1 mol%. Average nucleotide identity values between strain JS71T and S. rubneri DSM 26920T, S. parasanguinis ATCC 15912T, and S. australis CCUG 45919T were 88.9%, 80.8%, and 92.4%, respectively. Genome-to-genome distance values between strain JS71TS. rubneri DSM 26920T, S. parasanguinis ATCC 15912T, and S. australis CCUG 45919T were 36.5% (34-39%), 26.3% (23.9-28.7%), and 48.0% (45.4-50.6%), respectively. The major fatty acids of the strain were C16:0 (39.7%), C18:1 ω6c/C18:1 ω7c (15.5%), and C18:0 (10.4%). Based on these results, strain JS71T (= KCOM 2890T = JCM 33454T) should be a novel species of the genus Streptococcus, for which the name Streptococcus koreensis sp. nov. is proposed.

Lautropia dentalis sp. nov., Isolated from Human Dental Plaque of a Gingivitis Lesion.

A novel Gram-stain-negative, motile, and facultative anaerobic coccus, strain ChDC F240T was isolated from human subgingival dental plaque of a gingivitis lesion. The phylogenetic analysis based on the 16S ribosomal RNA gene (16S rDNA) sequence showed that the strain belonged to the genus Lautropia. 16S rDNA of strain ChDC F240T had the highest similarity to that of Lautropia mirabilis ATCC 51599T (98.8%). Major cellular fatty acids of strain ChDC F240T were C16:0 (43.9%) and C16:1ω6C/C16:1ω7C (38.1%). Draft genome of the strain was 3,834,139 bp in length and the G+C content was 65.0 mol%. Average nucleotide identity and genome-to-genome distance values between strain ChDC F240T and L. mirabilis ATCC 51599 T were 81.99% and 28.50% (26.1-30.9%), respectively. These results reveal that strain ChDC F240T is a novel species within the genus Lautropia, for which the name Lautropia dentalis sp. nov. is proposed; type strain is ChDC F240T (= KCOM 2505T = JCM 33297T).

Streptococcus chosunense sp. nov., Isolated from Human Postoperative Maxillary Cyst.

A novel facultative anaerobic, non-spore forming, non-motile, and Gram-stain-positive coccus, designated strain ChDC B353T, was isolated from human postoperative maxillary cyst. The 16S ribosomal RNA gene (16S rDNA) sequence of the strain was most closely related to those of Streptococcus pseudopneumoniae ATCC BAA-960T (99.4%), Streptococcus mitis NCTC 12261T (99.3%), and Streptococcus pneumoniae NCTC 7465T (99.2%). The major fatty acids of the strain were C16:0 (43.2%) and C18:1 ω6c/C18:1 ω7c (20.2%). The genome of strain ChDC B353T was composed of 1,902,053 bps. The DNA G+C content of the strain was 40.2 mol%. Average nucleotide identity (ANI) values between strain ChDC B353T and S. pseudopneumoniae ATCC BAA-960T, S. mitis NCTC 12261T, and S. pneumoniae NCTC 7465T were 91.9%, 93.5%, and 91.3%, respectively. Genome-to-genome distance (GGD) values between strain ChDC B353T and S. pseudopneumoniae ATCC BAA-960T, S. mitis NCTC 12261T, or S. pneumoniae NCTC 7465T were 46.6% (44.0-49.2%), 53.2% (50.5-55.9%), and 46.0% (43.5-48.7%), respectively. The threshold values of ANI and GGD for species discrimination are 95-96% and 70%, respectively. These results reveal that strain ChDC B353T (= KCOM 1699T = JCM 33453T) is a novel species belonging to genus Streptococcus, for which a name of Streptococcus chosunense sp. nov. is proposed.

Lachnoanaerobaculum gingivalis sp. nov., Isolated from Human Subgingival Dental Plaque of a Gingivitis Lesion.

A novel Gram-stain-positive, obligately anaerobic, spore-forming rod, designated strain ChDC B114T, was isolated from a human dental plaque of a gingivitis lesion. The strain was characterized by polyphasic taxonomic analysis to identify it at the species level. The 16S ribosomal RNA gene (16S rDNA) sequence analysis revealed that the strain belongs to the genus Lachnoanaerobaculum. The percent similarity of the 16S rDNA of the strain was closest to the homologous gene sequence of Lachnoanaerobaculum orale N1T (98.5%) and Lachnoanaerobaculum saburreum CCUG 28089T (97.6%). The major fatty acids of strain ChDC B114T were C16:0 (30.7%), C14:0 (17.7%), iso-C19:0 (14.9%), and C17:0 2OH (12.0%). The draft genome of strain ChDC B114T was 3,097,953 bp in length. The G+C content of the strain was 35.9 mol %. Average nucleotide identity values between strain ChDC B114T and L. orale N1T and L. saburreum CCUG 28089T were 83.2% and 82.0%, respectively. Genome-to-genome distance values between strain ChDC B114T and L. orale N1T and L. saburreum CCUG 28089T were 26.8% (24.5-29.3%) and 26.30% (24.0-28.8%), respectively. Based on these results, strain ChDC B114T (= KCOM 2030T = JCM 33452T) should be classified as a novel species of genus Lachnoanaerobaculum, for which the name Lachnoanaerobaculum gingivalis sp. nov. is proposed.

Prevotella koreensis sp. nov., Isolated from Human Subgingival Dental Plaque of Periodontitis Lesion.

A novel Gram-negative, obligately anaerobic, non-motile, non-spore forming, and rod-shaped bacterium, designated strain JS262T, was isolated from human subgingival plaque of periodontitis lesion and was characterized by polyphasic taxonomic analysis. Comparison of 16S ribosomal RNA gene (16S rDNA) sequence revealed that the strain belonged to the genus Prevotella. The percent similarity of 16S rDNA of strain JS262T was closest to those of Prevotella buccae ATCC 33574T (89.1%) and Prevotella shahii JCM 12083T (88.9%). The major fatty acids of strain JS262T were C16:0 (29.2%), iso-C15:0 (19.2%), and anteiso-C15:0 (16.9%). Complete genome of strain JS262T was 2,691,540 bp in length and the G+C content was 43.9 mol%. Average nucleotide identity and genome-to-genome distance values between strain JS262T and P. buccae ATCC 33574T or P. loescheii DSM 19665T were > 70.4% and > 30.1%, respectively. On the basis of these data, a novel Prevotella species is proposed: Prevotella koreensis sp. nov. The type strain of P. koreensis is JS262T (= KCOM 3155T = JCM 33298T).

Streptococcus periodonticum sp. nov., Isolated from Human Subgingival Dental Plaque of Periodontitis Lesion.

A novel facultative anaerobic and Gram-stain-positive coccus, designated strain ChDC F135T, was isolated from human subgingival dental plaque of periodontitis lesion and was characterized by polyphasic taxonomic analysis. The 16S rRNA gene (16S rDNA) sequence of strain ChDC F135T was closest to that of Streptococcus sinensis HKU4T (98.2%), followed by Streptococcus intermedia SK54T (97.0%), Streptococcus constellatus NCTC11325T (96.0%), and Streptococcus anginosus NCTC 10713T (95.7%). In contrast, phylogenetic analysis based on the superoxide dismutase gene (sodA) and the RNA polymerase beta-subunit gene (rpoB) showed that the nucleotide sequence similarities of strain ChDC F135T were highly similar to the corresponding genes of S. anginosus NCTC 10713T (99.2% and 97.6%, respectively), S. constellatus NCTC11325T (87.8% and 91.4%, respectively), and S. intermedia SK54T (85.8% and 91.2%, respectively) rather than those of S. sinensis HKU4T (80.5% and 82.6%). The complete genome of strain ChDC F135T consisted of 1,901,251 bp and the G+C content was 38.9 mol %. Average nucleotide identity value between strain ChDC F135T and S. sinensis HKU4T or S. anginosus NCTC 10713T were 75.7% and 95.6%, respectively. The C14:0 composition of the cellular fatty acids of strain ChDC F135T (32.8%) was different from that of S. intermedia (6-8%), S. constellatus (6-13%), and S. anginosus (13-20%). Based on the results of phylogenetic and phenotypic analysis, strain ChDC F135T (= KCOM 2412T = JCM 33300T) was classified as a type strain of a novel species of the genus Streptococcus, for which we proposed the name Streptococcus periodonticum sp. nov.

Streptococcus gwangjuense sp. nov., Isolated from Human Pericoronitis.

A novel facultative anaerobic, Gram-stain-negative coccus, designated strain ChDC B345T, was isolated from human pericoronitis lesion and was characterized by polyphasic taxonomic analysis. The 16S ribosomal RNA gene (16S rDNA) sequence revealed that the strain belonged to the genus Streptococcus. The 16S rDNA sequence of strain ChDC B345T was most closely related to those of  Streptococcus mitis NCTC 12261T (99.5%) and Streptococcus pseudopneumoniae ATCC BAA-960T (99.5%). Complete genome of strain ChDC B345T was 1,972,471 bp in length and the G + C content was 40.2 mol%. Average nucleotide identity values between strain ChDC B345T and S. pseudopneumoniae ATCC BAA-960T or S. mitis NCTC 12261T were 92.17% and 93.63%, respectively. Genome-to-genome distance values between strain ChDC B345T and S. pseudopneumoniae ATCC BAA-960T or S. mitis NCTC 12261T were 47.8% (45.2-50.4%) and 53.0% (51.0-56.4%), respectively. Based on these results, strain ChDC B345T (= KCOM 1679T = JCM 33299T) should be classified as a novel species of genus Streptococcus, for which we propose the name Streptococcus gwangjuense sp. nov.