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Wajima T, Sugawara T, Tanaka E, Uchiya KI. Molecular characterization of a novel putative pathogen, Streptococcus nakanoensis sp. nov., isolated from sputum culture. Microbiol Spectr 2024; 12:e0135424. [PMID: 39269180 DOI: 10.1128/spectrum.01354-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Accepted: 08/06/2024] [Indexed: 09/15/2024] Open
Abstract
Reports of novel species of α-hemolytic Streptococcus have increased recently. However, limited information exists regarding the pathogenicity of these species, with the exception of Streptococcus pneumoniae and Streptococcus pseudopneumoniae. In this study, a quinolone-resistant α-Streptococcus strain, MTG105, was isolated from the sputum of a patient with pneumonia. This strain was first identified as S. pneumoniae at the hospital laboratory; however, it exhibited unique genetic features upon further analysis. Digital DNA-DNA hybridization and average nucleotide identity based on BLAST values from whole-genome sequencing revealed MTG105 to be a novel species closely related to S. pseudopneumoniae. Although MTG105 carried two copies of the pneumolysin gene, similar to S. pseudopneumoniae, this isolate exhibited susceptibility to optochin under both aerobic and 5% CO2 conditions. Notably, no biochemical features could be used to definitively identify this species. In an infection assay using organotypic lung tissue models, MTG105 induced epithelial damage comparable to that of S. pneumoniae and S. pseudopneumoniae, possibly suggesting its potential as a pathogenic α-Streptococcus. The natural transformation abilities of Streptococcus species facilitate their exchange of genes within the same genus, resulting in the existence of species with increasingly more diverse genome structures. Therefore, the identification of this species highlights the importance of monitoring the emergence of novel species exhibiting virulence and/or multidrug resistance. This isolate was proposed as a novel species, designated Streptococcus nakanoensis sp. nov. The type strain was MTG 105T (= JCM 35953T = CCUG 76894T). IMPORTANCE The genus Streptococcus encompasses a wide range of bacteria with more than 60 species. Recently, there has been a notable increase in reports of novel species of α-Streptococcus based on genomic analysis data. However, limited information exists regarding the pathogenicity of these species. In this study, a quinolone-resistant α-hemolytic Streptococcus strain, MTG105, was isolated from a patient with pneumonia. Genetic analysis revealed that this species was a novel species closely related to S. pseudopneumoniae. In an infection assay using organotypic lung tissue models, MTG105 induced epithelial damage comparable to that caused by S. pneumoniae and S. pseudopneumoniae, strongly suggesting its potential as a pathogenic α-Streptococcus. The natural transformation abilities of Streptococcus species facilitate gene exchange within the same genus, leading to the emergence of species with increasingly diverse genome structures. Therefore, the identification of this species underscores the importance of monitoring the emergence of novel species exhibiting virulence and/or multidrug resistance.
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Affiliation(s)
- Takeaki Wajima
- Department of Microbiology, Faculty of Pharmacy, Meijo University, Nagoya, Japan
| | | | - Emi Tanaka
- Department of Microbiology, Faculty of Pharmacy, Meijo University, Nagoya, Japan
| | - Kei-Ichi Uchiya
- Department of Microbiology, Faculty of Pharmacy, Meijo University, Nagoya, Japan
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Nguyen HV, Trinh ATV, Bui LNH, Hoang ATL, Tran QTL, Trinh TT. Streptococcus raffinosi sp. nov., isolated from human breast milk samples. Int J Syst Evol Microbiol 2024; 74. [PMID: 38958657 DOI: 10.1099/ijsem.0.006442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024] Open
Abstract
Novel Gram-positive, catalase-negative, α-haemolytic cocci were isolated from breast milk samples of healthy mothers living in Hanoi, Vietnam. The 16S rRNA gene sequences of these strains varied by 0-2 nucleotide polymorphisms. The 16S rRNA gene sequence of one strain, designated as BME SL 6.1T, showed the highest similarity to those of Streptococcus salivarius NCTC 8618T (99.4 %), Streptococcus vestibularis ATCC 49124T (99.4 %), and Streptococcus thermophilus ATCC 19258T (99.3 %) in the salivarius group. Whole genome sequencing was performed on three selected strains. Phylogeny based on 631 core genes clustered the three strains into the salivarius group, and the strains were clearly distinct from the other species in this group. The average nucleotide identity (ANI) value of strain BME SL 6.1T exhibited the highest identity with S. salivarius NCTC 8618T (88.4 %), followed by S. vestibularis ATCC 49124T (88.3 %) and S. thermophilus ATCC 19258T (87.4 %). The ANI and digital DNA-DNA hybridization values between strain BME SL 6.1T and other species were below the cut-off value (95 and 70 %, respectively), indicating that it represents a novel species of the genus Streptococcus. The strains were able to produce α-galactosidase and acid from raffinose and melibiose. Therefore, we propose to assign the strains to a new species of the genus Streptococcus as Streptococcus raffinosi sp. nov. The type strain is BME SL 6.1T (=VTCC 12812T=NBRC 116368T).
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Affiliation(s)
- Ha Viet Nguyen
- VNU-Institute of Microbiology and Biotechnology, Vietnam National University, Hanoi, Vietnam
| | - Anh Thi Van Trinh
- VNU-Institute of Microbiology and Biotechnology, Vietnam National University, Hanoi, Vietnam
| | - Linh Nguyen Hai Bui
- VNU-Institute of Microbiology and Biotechnology, Vietnam National University, Hanoi, Vietnam
| | - Anh Thi Lan Hoang
- VNU-Institute of Microbiology and Biotechnology, Vietnam National University, Hanoi, Vietnam
| | - Quyen Thi Le Tran
- VNU-Institute of Microbiology and Biotechnology, Vietnam National University, Hanoi, Vietnam
| | - Trung Thanh Trinh
- VNU-Institute of Microbiology and Biotechnology, Vietnam National University, Hanoi, Vietnam
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Munson E, Carella A, Carroll KC. Valid and accepted novel bacterial taxa derived from human clinical specimens and taxonomic revisions published in 2022. J Clin Microbiol 2023; 61:e0083823. [PMID: 37889007 PMCID: PMC10662342 DOI: 10.1128/jcm.00838-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023] Open
Abstract
Although some nomenclature changes have caused consternation among clinical microbiologists, the discovery of novel taxa and improving classification of existing groups of organisms is exciting and adds to our understanding of microbial pathogenesis. In this mini-review, we present an in-depth summary of novel taxonomic designations and revisions to prokaryotic taxonomy that were published in 2022. Henceforth, these bacteriology taxonomic summaries will appear annually. Several of the novel Gram-positive organisms have been associated with disease, namely, the Corynebacterium kroppenstedtii-like organisms Corynebacterium parakroppenstedtii sp. nov. and Corynebacterium pseudokroppenstedtii sp. nov. A newly described Streptococcus species, Streptococcus toyakuensis sp. nov., is noteworthy for exhibiting multi-drug resistance. Among the novel Gram-negative pathogens, Vibrio paracholerae sp. nov. stands out as an organism associated with diarrhea and sepsis and has probably been co-circulating with pandemic Vibrio cholerae for decades. Many new anaerobic organisms have been described in this past year largely from genetic assessments of gastrointestinal microbiome collections. With respect to revised taxa, as discussed in previous reviews, the genus Bacillus continues to undergo further division into additional genera and reassignment of existing species into them. Reassignment of two subspecies of Fusobacterium nucleatum to species designations (Fusobacterium animalis sp. nov. and Fusobacterium vincentii sp. nov.) is also noteworthy. As was typical of previous reviews, literature updates for selected clinically relevant organisms discovered between 2017 and 2021 have been included.
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Affiliation(s)
- Erik Munson
- Department of Medical Laboratory Science, Marquette University, Milwaukee, Wisconsin, USA
| | - Arianna Carella
- Department of Medical Laboratory Science, Marquette University, Milwaukee, Wisconsin, USA
| | - Karen C. Carroll
- Division of Medical Microbiology, Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Ding L, Ren S, Song Y, Zang C, Liu Y, Guo H, Yang W, Guan H, Liu J. Modulation of gut microbiota and fecal metabolites by corn silk among high-fat diet-induced hypercholesterolemia mice. Front Nutr 2022; 9:935612. [PMID: 35978956 PMCID: PMC9376456 DOI: 10.3389/fnut.2022.935612] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 07/01/2022] [Indexed: 11/18/2022] Open
Abstract
Corn silk (CS) is known to reduce cholesterol levels, but its underlying mechanisms remain elusive concerning the gut microbiota and metabolites. The aim of our work was to explore how altered gut microbiota composition and metabolite profile are influenced by CS intervention in mice using integrated 16S ribosomal RNA (rRNA) sequencing and an untargeted metabolomics methodology. The C57BL/6J mice were fed a normal control diet, a high-fat diet (HFD), and HFD supplemented with the aqueous extract of CS (80 mg/mL) for 8 weeks. HFD-induced chronic inflammation damage is alleviated by CS extract intervention and also resulted in a reduction in body weight, daily energy intake as well as serum and hepatic total cholesterol (TC) levels. In addition, CS extract altered gut microbial composition and regulated specific genera viz. Allobaculum, Turicibacter, Romboutsia, Streptococcus, Sporobacter, Christensenella, ClostridiumXVIII, and Rikenella. Using Spearman’s correlation analysis, we determined that Turicibacter and Rikenella were negatively correlated with hypercholesterolemia-related parameters. Fecal metabolomics analysis revealed that CS extract influences multiple metabolic pathways like histidine metabolism-related metabolites (urocanic acid, methylimidazole acetaldehyde, and methiodimethylimidazoleacetic acid), sphingolipid metabolism-related metabolites (sphinganine, 3-dehydrosphinganine, sphingosine), and some bile acids biosynthesis-related metabolites including chenodeoxycholic acid (CDCA), lithocholic acid (LCA), ursodeoxycholic acid (UDCA), and glycoursodeoxycholic acid (GUDCA). As a whole, the present study indicates that the modifications in the gut microbiota and subsequent host bile acid metabolism may be a potential mechanism for the antihypercholesterolemic effects of CS extract.
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Affiliation(s)
- Lin Ding
- Department of Scientific Research, Science and Technology Achievement Transformation Center, Qiqihar Medical University, Qiqihar, China
| | - Shan Ren
- College of Basic Medical, Qiqihar Medical University, Qiqihar, China
| | - Yaoxin Song
- Department of Scientific Research, Science and Technology Achievement Transformation Center, Qiqihar Medical University, Qiqihar, China
| | - Chuangang Zang
- Department of Scientific Research, Science and Technology Achievement Transformation Center, Qiqihar Medical University, Qiqihar, China
| | - Yuchao Liu
- Department of Scientific Research, Science and Technology Achievement Transformation Center, Qiqihar Medical University, Qiqihar, China
| | - Hao Guo
- Department of Scientific Research, Science and Technology Achievement Transformation Center, Qiqihar Medical University, Qiqihar, China
| | - Wenqing Yang
- Department of Scientific Research, Science and Technology Achievement Transformation Center, Qiqihar Medical University, Qiqihar, China
| | - Hong Guan
- Department of Scientific Research, Science and Technology Achievement Transformation Center, Qiqihar Medical University, Qiqihar, China
| | - Jicheng Liu
- Department of Scientific Research, Science and Technology Achievement Transformation Center, Qiqihar Medical University, Qiqihar, China.,Qiqihar Academy of Medical Sciences, Qiqihar, China
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Kumar S, Bansal K, Sethi SK. Reclassification of Streptococcus ilei as a later heterotypic synonym of Streptococcus koreensis based on whole-genome sequence analysis. Arch Microbiol 2022; 204:408. [PMID: 35727397 DOI: 10.1007/s00203-022-02979-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 12/01/2022]
Abstract
The genus Streptococcus, a member of family Streptococcaceae, is known for its wide range of industrial, clinical and human relevance. Among the species of genus Streptococcus two members, namely Streptococcus koreensis and Streptococcus ilei, were isolated from subgingival dental plaque and human small intestinal fluid, respectively. The 16S rRNA gene sequence similarity of the type strains of these members shows a similarity of 99.87%. In this study, we performed a systematic study to clarify the taxonomic assignment of these two species. Genome similarity assessment based on whole-genome sequence information such as average nucleotide identity using orthoANI and fastANI, digital DNA-DNA hybridization value between S. koreensis and S. ilei were 96.31, 96.60, 86.4 and 97.63, respectively. All these genome similarity values clearly exceeded the species delineation cutoffs. Phylogenetic assessment using 16S rRNA gene and whole-genome information using PhyloPhlAn, which uses around 400 conserved genes across bacterial phyla, provides additional evidence for these members forming a monophyletic clade in the phylogenetic tree. Pan genome analysis suggests a very large core genome (n = 1374) and the presence of no unique gene between the genomes of S. koreensis and S. ilei. Additionally, we found highly syntenic genomes of type strains of these two species. Based on these evidences, we propose S. ilei should be reclassified as a later heterotypic synonym of S. koreensis.
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Affiliation(s)
- Sanjeet Kumar
- School of Biotechnology, Gangadhar Meher University, Sambalpur, Odisha, 768004, India
| | - Kanika Bansal
- CSIR-Institute of Microbial Technology, Chandigarh, 160036, India
| | - Santosh Kumar Sethi
- School of Biotechnology, Gangadhar Meher University, Sambalpur, Odisha, 768004, India.
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Oren A, Garrity GM. Valid publication of new names and new combinations effectively published outside the IJSEM. Validation List no. 203. Int J Syst Evol Microbiol 2022; 72. [PMID: 35108178 DOI: 10.1099/ijsem.0.005167] [Citation(s) in RCA: 275] [Impact Index Per Article: 137.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Aharon Oren
- The Institute of Life Sciences, The Hebrew University of Jerusalem, The Edmond J. Safra Campus, 9190401 Jerusalem, Israel
| | - George M Garrity
- Department of Microbiology & Molecular Genetics, Biomedical Physical Sciences, Michigan State University, East Lansing, MI 48824-4320, USA
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