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Britton TA, Wu C, Chen YW, Franklin D, Chen Y, Camacho MI, Luong TT, Das A, Ton-That H. The respiratory enzyme complex Rnf is vital for metabolic adaptation and virulence in Fusobacterium nucleatum. mBio 2024; 15:e0175123. [PMID: 38059640 PMCID: PMC10790702 DOI: 10.1128/mbio.01751-23] [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: 07/06/2023] [Accepted: 10/20/2023] [Indexed: 12/08/2023] Open
Abstract
IMPORTANCE This paper illuminates the significant question of how the oral commensal Fusobacterium nucleatum adapts to the metabolically changing environments of several extra-oral sites such as placenta and colon to promote various diseases as an opportunistic pathogen. We demonstrate here that the highly conserved Rhodobacter nitrogen-fixation complex, commonly known as Rnf complex, is key to fusobacterial metabolic adaptation and virulence. Genetic disruption of this Rnf complex causes global defects in polymicrobial interaction, biofilm formation, cell growth and morphology, hydrogen sulfide production, and ATP synthesis. Targeted metabolomic profiling demonstrates that the loss of this respiratory enzyme significantly diminishes catabolism of numerous amino acids, which negatively impacts fusobacterial virulence as tested in a preterm birth model in mice.
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Affiliation(s)
- Timmie A. Britton
- Molecular Biology Institute, University of California, Los Angeles, California, USA
| | - Chenggang Wu
- Department of Microbiology & Molecular Genetics, University of Texas McGovern Medical School, Houston, Texas, USA
| | - Yi-Wei Chen
- Division of Oral & Systemic Health Sciences, School of Dentistry, University of California, Los Angeles, California, USA
| | - Dana Franklin
- Molecular Biology Institute, University of California, Los Angeles, California, USA
| | - Yimin Chen
- Division of Oral & Systemic Health Sciences, School of Dentistry, University of California, Los Angeles, California, USA
| | - Martha I. Camacho
- Division of Oral & Systemic Health Sciences, School of Dentistry, University of California, Los Angeles, California, USA
| | - Truc T. Luong
- Division of Oral & Systemic Health Sciences, School of Dentistry, University of California, Los Angeles, California, USA
| | - Asis Das
- Department of Medicine, Neag Comprehensive Cancer Center, University of Connecticut Health Center, Farmington, Connecticut, USA
| | - Hung Ton-That
- Molecular Biology Institute, University of California, Los Angeles, California, USA
- Division of Oral & Systemic Health Sciences, School of Dentistry, University of California, Los Angeles, California, USA
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, California, USA
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Britton TA, Wu C, Chen YW, Franklin D, Chen Y, Camacho MI, Luong TT, Das A, Ton-That H. The respiratory enzyme complex Rnf is vital for metabolic adaptation and virulence in Fusobacterium nucleatum. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.13.544113. [PMID: 37398403 PMCID: PMC10312631 DOI: 10.1101/2023.06.13.544113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
A prominent oral commensal and opportunistic pathogen, Fusobacterium nucleatum can traverse to extra-oral sites such as placenta and colon, promoting adverse pregnancy outcomes and colorectal cancer, respectively. How this anaerobe sustains many metabolically changing environments enabling its virulence potential remains unclear. Informed by our genome-wide transposon mutagenesis, we report here that the highly conserved Rnf complex, encoded by the rnfCDGEAB gene cluster, is key to fusobacterial metabolic adaptation and virulence. Genetic disruption of the Rnf complex via non-polar, in-frame deletion of rnfC (Δ rnfC ) abrogates polymicrobial interaction (or coaggregation) associated with adhesin RadD and biofilm formation. The defect in coaggregation is not due to reduced cell surface of RadD, but rather an increased level of extracellular lysine, which binds RadD and inhibits coaggregation. Indeed, removal of extracellular lysine via washing Δ rnfC cells restores coaggregation, while addition of lysine inhibits this process. These phenotypes mirror that of a mutant (Δ kamAΔ ) that fails to metabolize extracellular lysine. Strikingly, the Δ rnfC mutant is defective in ATP production, cell growth, cell morphology, and expression of the enzyme MegL that produces hydrogen sulfide from cysteine. Targeted metabolic profiling demonstrated that catabolism of many amino acids, including histidine and lysine, is altered in Δ rnfC cells, thereby reducing production of ATP and metabolites including H2S and butyrate. Most importantly, we show that the Δ rnfC mutant is severely attenuated in a mouse model of preterm birth. The indispensable function of Rnf complex in fusobacterial pathogenesis via modulation of bacterial metabolism makes it an attractive target for developing therapeutic intervention.
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Genetic Determinants of Hydrogen Sulfide Biosynthesis in Fusobacterium nucleatum Are Required for Bacterial Fitness, Antibiotic Sensitivity, and Virulence. mBio 2022; 13:e0193622. [PMID: 36073813 PMCID: PMC9600241 DOI: 10.1128/mbio.01936-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Gram-negative anaerobe Fusobacterium nucleatum is a major producer of hydrogen sulfide (H2S), a volatile sulfur compound that causes halitosis. Here, we dissected the genetic determinants of H2S production and its role in bacterial fitness and virulence in this important member of the oral microbiome. F. nucleatum possesses four enzymes, CysK1, CysK2, Hly, and MegL, that presumably metabolize l-cysteine to H2S, and CysK1 was previously shown to account for most H2S production in vitro, based on correlations of enzymatic activities with gene expression at mid-log phase. Our molecular studies showed that cysK1 and megL were highly expressed at the late exponential growth phase, concomitant with high-level H2S production, while the expression levels of the other genes remained substantially lower during all growth phases. Although the genetic deletion of cysK1 without supplementation with a CysK1-catalyzed product, lanthionine, caused cell death, the conditional ΔcysK1 mutant and a mutant lacking hly were highly proficient in H2S production. In contrast, a mutant devoid of megL showed drastically reduced H2S production, and a cysK2 mutant showed only minor deficiencies. Intriguingly, the exposure of these mutants to various antibiotics revealed that only the megL mutant displayed altered susceptibility compared to the parental strain: partial sensitivity to nalidixic acid and resistance to kanamycin. Most significantly, the megL mutant was attenuated in virulence in a mouse model of preterm birth, with considerable defects in the spread to amniotic fluid and the colonization of the placenta and fetus. Evidently, the l-methionine γ-lyase MegL is a major H2S-producing enzyme in fusobacterial cells that significantly contributes to fusobacterial virulence and antibiotic susceptibility.
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Dey S, Shahrear S, Afroj Zinnia M, Tajwar A, Islam ABMMK. Functional Annotation of Hypothetical Proteins From the Enterobacter cloacae B13 Strain and Its Association With Pathogenicity. Bioinform Biol Insights 2022; 16:11779322221115535. [PMID: 35958299 PMCID: PMC9358594 DOI: 10.1177/11779322221115535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/11/2022] [Indexed: 11/25/2022] Open
Abstract
Enterobacter cloacae B13 strain is a rod-shaped gram-negative bacterium that belongs to the Enterobacteriaceae family. It can cause respiratory and urinary tract infections, and is responsible for several outbreaks in hospitals. E. cloacae has become an important pathogen and an emerging global threat because of its opportunistic and multidrug resistant ability. However, little knowledge is present about a large portion of its proteins and functions. Therefore, functional annotation of the hypothetical proteins (HPs) can provide an improved understanding of this organism and its virulence activity. The workflow in the study included several bioinformatic tools which were utilized to characterize functions, family and domains, subcellular localization, physiochemical properties, and protein-protein interactions. The E. cloacae B13 strain has overall 604 HPs, among which 78 were functionally annotated with high confidence. Several proteins were identified as enzymes, regulatory, binding, and transmembrane proteins with essential functions. Furthermore, 23 HPs were predicted to be virulent factors. These virulent proteins are linked to pathogenesis with their contribution to biofilm formation, quorum sensing, 2-component signal transduction or secretion. Better knowledge about the HPs’ characteristics and functions will provide a greater overview of the proteome. Moreover, it will help against E. cloacae in neonatal intensive care unit (NICU) outbreaks and nosocomial infections.
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Affiliation(s)
- Supantha Dey
- Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh
| | - Sazzad Shahrear
- Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh
| | | | - Ahnaf Tajwar
- Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh
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Wu DD, Ngowi EE, Zhai YK, Wang YZ, Khan NH, Kombo AF, Khattak S, Li T, Ji XY. Role of Hydrogen Sulfide in Oral Disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:1886277. [PMID: 35116090 PMCID: PMC8807043 DOI: 10.1155/2022/1886277] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 11/20/2021] [Accepted: 12/14/2021] [Indexed: 12/13/2022]
Abstract
Oral diseases are among the most common human diseases yet less studied. These diseases affect both the physical, mental, and social health of the patients resulting in poor quality of life. They affect all ages, although severe stages are mostly observed in older individuals. Poor oral hygiene, genetics, and environmental factors contribute enormously to the development and progression of these diseases. Although there are available treatment options for these diseases, the recurrence of the diseases hinders their efficiency. Oral volatile sulfur compounds (VSCs) are highly produced in oral cavity as a result of bacteria activities. Together with bacteria components such as lipopolysaccharides, VSCs participate in the progression of oral diseases by regulating cellular activities and interfering with the immune response. Hydrogen sulfide (H2S) is a gaseous neurotransmitter primarily produced endogenously and is involved in the regulation of cellular activities. The gas is also among the VSCs produced by oral bacteria. In numerous diseases, H2S have been reported to have dual effects depending on the cell, concentration, and donor used. In oral diseases, high production and subsequent utilization of this gas have been reported. Also, this high production is associated with the progression of oral diseases. In this review, we will discuss the production of H2S in oral cavity, its interaction with cellular activities, and most importantly its role in oral diseases.
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Affiliation(s)
- Dong-Dong Wu
- School of Stomatology, Henan University, Kaifeng, Henan 475004, China
- Henan International Joint Laboratory for Nuclear Protein Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, Henan 475004, China
- Kaifeng Municipal Key Laboratory of Cell Signal Transduction, Henan Provincial Engineering Centre for Tumor Molecular Medicine, Henan University, Kaifeng, Henan 475004, China
| | - Ebenezeri Erasto Ngowi
- Henan International Joint Laboratory for Nuclear Protein Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, Henan 475004, China
- Kaifeng Municipal Key Laboratory of Cell Signal Transduction, Henan Provincial Engineering Centre for Tumor Molecular Medicine, Henan University, Kaifeng, Henan 475004, China
- Department of Biological Sciences, Faculty of Science, Dar es Salaam University College of Education, Dar es Salaam 2329, Tanzania
| | - Yuan-Kun Zhai
- School of Stomatology, Henan University, Kaifeng, Henan 475004, China
- Henan International Joint Laboratory for Nuclear Protein Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, Henan 475004, China
| | - Yi-Zhen Wang
- Henan International Joint Laboratory for Nuclear Protein Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, Henan 475004, China
- Kaifeng Municipal Key Laboratory of Cell Signal Transduction, Henan Provincial Engineering Centre for Tumor Molecular Medicine, Henan University, Kaifeng, Henan 475004, China
| | - Nazeer Hussain Khan
- Henan International Joint Laboratory for Nuclear Protein Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, Henan 475004, China
- School of Life Sciences, Henan University, Kaifeng, Henan 475004, China
| | - Ahmad Fadhil Kombo
- Henan International Joint Laboratory for Nuclear Protein Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, Henan 475004, China
- School of Life Sciences, Henan University, Kaifeng, Henan 475004, China
| | - Saadullah Khattak
- Henan International Joint Laboratory for Nuclear Protein Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, Henan 475004, China
- School of Life Sciences, Henan University, Kaifeng, Henan 475004, China
| | - Tao Li
- Henan International Joint Laboratory for Nuclear Protein Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, Henan 475004, China
- Kaifeng Key Laboratory of Infection and Biological Safety, School of Basic Medical Sciences, Henan University, Kaifeng, Henan 475004, China
| | - Xin-Ying Ji
- Henan International Joint Laboratory for Nuclear Protein Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, Henan 475004, China
- Kaifeng Key Laboratory of Infection and Biological Safety, School of Basic Medical Sciences, Henan University, Kaifeng, Henan 475004, China
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Xu S, Luo X, Xing Y, Liu S, Huang Q, Chen W. Complete genome sequence of Raoultella sp. strain X13, a promising cell factory for the synthesis of CdS quantum dots. 3 Biotech 2019; 9:120. [PMID: 30854280 DOI: 10.1007/s13205-019-1649-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 02/22/2019] [Indexed: 10/27/2022] Open
Abstract
A novel cadmium-resistant bacterium, Raoultella sp. strain X13, recently isolated from heavy metal-contaminated soil, and this strain can synthesize CdS quantum dots using cadmium nitrate [Cd(NO4)2] and l-cysteine. Biomineralization of CdS by strain X13 can efficiently remove cadmium from aqueous solution. To illuminate the molecular mechanisms for the biosynthesis of CdS nanoparticle, the complete genome of Raoultella sp. strain X13 was sequenced. The whole genome sequence comprises a circular chromosome and a circular plasmid. Cysteine desulfhydrase smCSE has been previously found to be associated with the synthesis of CdS quantum dots. Bioinformatics analysis indicated that the genome of Raoultella sp. strain X13 encodes five putative cysteine desulfhydrases and all of them are located in the chromosome. The genome information may help us to determine the molecular mechanisms of the synthesis of CdS quantum dots and potentially enable us to engineer this microorganism for applications in biotechnology.
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Su YQ, Zhao YJ, Wu N, Chen YE, Zhang WJ, Qiao DR, Cao Y. Chromium removal from solution by five photosynthetic bacteria isolates. Appl Microbiol Biotechnol 2017; 102:1983-1995. [PMID: 29279958 DOI: 10.1007/s00253-017-8690-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/01/2017] [Accepted: 12/02/2017] [Indexed: 01/26/2023]
Abstract
Biological method has been recognized as a low-cost and ecofriendly approach for removing heavy metals from aqueous wastes. In this study, the ability of five photosynthetic bacteria isolates (strains labeled SC01, HN02, SC05, JS01, and YN01) was examined for their ability to remove Cr from Cr-containing solutions. Furthermore, the possible removal mechanisms were elucidated by comparing chromium removal rates, antioxidant reaction, and accumulation of reactive oxygen species (ROS). Among the five bacteria, strains SC01 and SC05 presented the highest removal rates of chromium ions and the activity of cysteine desulfhydrase under Cr stress. They also showed lower levels of ROS and cell death than the other three bacteria strains under Cr stress. In addition, total bacteriochlorophyll content and activities of six antioxidant enzymes in SC01 were highest among these selected strains. On the contrary, strain HN02 presented the lowest level of Cr removal and the lowest activities of antioxidant enzymes. It also exhibited the highest level of ROS under Cr(VI) stress. Overall, these results show that the strains SC01 and SC05 have good Cr removal ability and could be used for removal of Cr in industrial effluents.
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Affiliation(s)
- Yan-Qiu Su
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, China.,Tongwei Group Co. Ltd, Chengdu, Chengdu, China
| | - Yang-Juan Zhao
- College of Life Sciences, Sichuan Agricultural University, Ya'an, China
| | - Nan Wu
- College of Life Sciences, Sichuan Agricultural University, Ya'an, China
| | - Yang-Er Chen
- College of Life Sciences, Sichuan Agricultural University, Ya'an, China
| | - Wei-Jia Zhang
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, China
| | - Dai-Rong Qiao
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, China
| | - Yi Cao
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, China.
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Abstract
Answer questions and earn CME/CNE The human body harbors enormous numbers of microbiota that influence cancer susceptibility, in part through their prodigious metabolic capacity and their profound influence on immune cell function. Microbial pathogens drive tumorigenesis in 15% to 20% of cancer cases. Even larger numbers of malignancies are associated with an altered composition of commensal microbiota (dysbiosis) based on microbiome studies using metagenomic sequencing. Although association studies cannot distinguish whether changes in microbiota are causes or effects of cancer, a causative role is supported by rigorously controlled preclinical studies using gnotobiotic mouse models colonized with one or more specific bacteria. These studies demonstrate that microbiota can alter cancer susceptibility and progression by diverse mechanisms, such as modulating inflammation, inducing DNA damage, and producing metabolites involved in oncogenesis or tumor suppression. Evidence is emerging that microbiota can be manipulated for improving cancer treatment. By incorporating probiotics as adjuvants for checkpoint immunotherapy or by designing small molecules that target microbial enzymes, microbiota can be harnessed to improve cancer care. CA Cancer J Clin 2017;67:326-344. © 2017 American Cancer Society.
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Affiliation(s)
- Aadra P. Bhatt
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Matthew R. Redinbo
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Biochemistry & Biophysics, Microbiology & Immunology, and the Integrated Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Scott J. Bultman
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
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Basic A, Blomqvist M, Dahlén G, Svensäter G. The proteins of Fusobacterium spp. involved in hydrogen sulfide production from L-cysteine. BMC Microbiol 2017; 17:61. [PMID: 28288582 PMCID: PMC5348791 DOI: 10.1186/s12866-017-0967-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 03/01/2017] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Hydrogen sulfide (H2S) is a toxic foul-smelling gas produced by subgingival biofilms in patients with periodontal disease and is suggested to be part of the pathogenesis of the disease. We studied the H2S-producing protein expression of bacterial strains associated with periodontal disease. Further, we examined the effect of a cysteine-rich growth environment on the synthesis of intracellular enzymes in F. nucleatum polymorphum ATCC 10953. The proteins were subjected to one-dimensional (1DE) and two-dimensional (2DE) gel electrophoresis An in-gel activity assay was used to detect the H2S-producing enzymes; Sulfide from H2S, produced by the enzymes in the gel, reacted with bismuth forming bismuth sulfide, illustrated as brown bands (1D) or spots (2D) in the gel. The discovered proteins were identified with liquid chromatography - tandem mass spectrometry (LC-MS/MS). RESULTS Cysteine synthase and proteins involved in the production of the coenzyme pyridoxal 5'phosphate (that catalyzes the production of H2S) were frequently found among the discovered enzymes. Interestingly, a higher expression of H2S-producing enzymes was detected from bacteria incubated without cysteine prior to the experiment. CONCLUSIONS Numerous enzymes, identified as cysteine synthase, were involved in the production of H2S from cysteine and the expression varied among Fusobacterium spp. and strains. No enzymes were detected with the in-gel activity assay among the other periodontitis-associated bacteria tested. The expression of the H2S-producing enzymes was dependent on environmental conditions such as cysteine concentration and pH but less dependent on the presence of serum and hemin.
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Affiliation(s)
- Amina Basic
- Department of Oral Microbiology and Immunology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
| | - Madeleine Blomqvist
- Department of Oral Biology, Institute of Odontology, Malmö University, Malmö, Sweden
| | - Gunnar Dahlén
- Department of Oral Microbiology and Immunology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Gunnel Svensäter
- Department of Oral Biology, Institute of Odontology, Malmö University, Malmö, Sweden
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Dolan KT, Chang EB. Diet, gut microbes, and the pathogenesis of inflammatory bowel diseases. Mol Nutr Food Res 2016; 61. [PMID: 27346644 DOI: 10.1002/mnfr.201600129] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Revised: 06/09/2016] [Accepted: 06/15/2016] [Indexed: 12/14/2022]
Abstract
The rising incidence of inflammatory bowel diseases in recent decades has notably paralleled changing lifestyle habits in Western nations, which are now making their way into more traditional societies. Diet plays a key role in IBD pathogenesis, and there is a growing appreciation that the interaction between diet and microbes in a susceptible person contributes significantly to the onset of disease. In this review, we examine what is known about dietary and microbial factors that promote IBD. We summarize recent findings regarding the effects of diet in IBD epidemiology from prospective population cohort studies, as well as new insights into IBD-associated dysbiosis. Microbial metabolism of dietary components can influence the epithelial barrier and the mucosal immune system, and understanding how these interactions generate or suppress inflammation will be a significant focus of IBD research. Our knowledge of dietary and microbial risk factors for IBD provides important considerations for developing therapeutic approaches through dietary modification or re-shaping the microbiota. We conclude by calling for increased sophistication in designing studies on the role of diet and microbes in IBD pathogenesis and disease resolution in order to accelerate progress in response to the growing challenge posed by these complex disorders.
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Affiliation(s)
- Kyle T Dolan
- Section of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, The University of Chicago
| | - Eugene B Chang
- Section of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, The University of Chicago
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Africa CWJ, Nel J, Stemmet M. Anaerobes and bacterial vaginosis in pregnancy: virulence factors contributing to vaginal colonisation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 11:6979-7000. [PMID: 25014248 PMCID: PMC4113856 DOI: 10.3390/ijerph110706979] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 06/25/2014] [Accepted: 06/30/2014] [Indexed: 12/21/2022]
Abstract
The aetiology and pathogenesis of bacterial vaginosis (BV) is unclear but it appears to be associated with factors that disrupt the normal acidity of the vagina thus altering the equilibrium between the normal vaginal microbiota. BV has serious implications for female morbidity, including reports of pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. This paper reviewed new available information regarding possible factors contributing to the establishment of the BV vaginal biofilm, examined the proposed role of anaerobic microbial species recently detected by new culture-independent methods and discusses developments related to the effects of BV on human pregnancy. The literature search included Pubmed (NLM), LISTA (EBSCO), and Web of Science. Because of the complexity and diversity of population groups, diagnosis and methodology used, no meta-analysis was performed. Several anaerobic microbial species previously missed in the laboratory diagnosis of BV have been revealed while taking cognisance of newly proposed theories of infection, thereby improving our understanding and knowledge of the complex aetiology and pathogenesis of BV and its perceived role in adverse pregnancy outcomes.
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Affiliation(s)
- Charlene W J Africa
- Department of Medical Biosciences, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa.
| | - Janske Nel
- Department of Medical Biosciences, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa.
| | - Megan Stemmet
- Department of Medical Biosciences, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa.
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12
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Effects of pH and lactate on hydrogen sulfide production by oral Veillonella spp. Appl Environ Microbiol 2014; 80:4184-8. [PMID: 24795374 DOI: 10.1128/aem.00606-14] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Indigenous oral bacteria in the tongue coating such as Veillonella have been identified as the main producers of hydrogen sulfide (H2S), one of the major components of oral malodor. However, there is little information on the physiological properties of H2S production by oral Veillonella such as metabolic activity and oral environmental factors which may affect H2S production. Thus, in the present study, the H2S-producing activity of growing cells, resting cells, and cell extracts of oral Veillonella species and the effects of oral environmental factors, including pH and lactate, were investigated. Type strains of Veillonella atypica, Veillonella dispar, and Veillonella parvula were used. These Veillonella species produced H2S during growth in the presence of l-cysteine. Resting cells of these bacteria produced H2S from l-cysteine, and the cell extracts showed enzymatic activity to convert l-cysteine to H2S. H2S production by resting cells was higher at pH 6 to 7 and lower at pH 5. The presence of lactate markedly increased H2S production by resting cells (4.5- to 23.7-fold), while lactate had no effect on enzymatic activity in cell extracts. In addition to H2S, ammonia was produced in cell extracts of all the strains, indicating that H2S was produced by the catalysis of cystathionine γ-lyase (EC 4.4.1.1). Serine was also produced in cell extracts of V. atypica and V. parvula, suggesting the involvement of cystathionine β-synthase lyase (EC 4.2.1.22) in these strains. This study indicates that Veillonella produce H2S from l-cysteine and that their H2S production can be regulated by oral environmental factors, namely, pH and lactate.
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Kezuka Y, Abe N, Yoshida Y, Nonaka T. Purification, crystallization and preliminary X-ray analysis of two hydrogen sulfide-producing enzymes from Fusobacterium nucleatum. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:1507-10. [PMID: 23192034 PMCID: PMC3509975 DOI: 10.1107/s1744309112042546] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 10/11/2012] [Indexed: 11/10/2022]
Abstract
Hydrogen sulfide produced by oral bacteria is responsible for oral malodour. Two homologous hydrogen sulfide-producing enzymes, Fn1220 and Cdl, from Fusobacterium nucleatum (which actively produces hydrogen sulfide) were overproduced, purified and crystallized. X-ray diffraction data were collected from the crystals using a synchrotron-radiation source. The Fn1220 crystal belonged to tetragonal space group P4(1)2(1)2 or P4(3)2(1)2 (unit-cell parameters a=b=116.8, c=99.2 Å) and the Cdl crystal belonged to monoclinic space group P2(1) (unit-cell parameters a=84.9, b=70.9, c=87.6 Å, β=90.3°).
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Affiliation(s)
- Yuichiro Kezuka
- Department of Structural Biology, School of Pharmacy, Iwate Medical University, Yahaba, Iwate 028-3694, Japan.
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Thorn RMS, Greenman J. Microbial volatile compounds in health and disease conditions. J Breath Res 2012; 6:024001. [PMID: 22556190 PMCID: PMC7106765 DOI: 10.1088/1752-7155/6/2/024001] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 04/12/2012] [Indexed: 12/24/2022]
Abstract
Microbial cultures and/or microbial associated diseases often have a characteristic smell. Volatile organic compounds (VOCs) are produced by all microorganisms as part of their normal metabolism. The types and classes of VOC produced is wide, including fatty acids and their derivatives (e.g. hydrocarbons, aliphatic alcohols and ketones), aromatic compounds, nitrogen containing compounds, and volatile sulfur compounds. A diversity of ecological niches exist in the human body which can support a polymicrobial community, with the exact VOC profile of a given anatomical site being dependent on that produced by both the host component and the microbial species present. The detection of VOCs is of interest to various disciplines, hence numerous analytical approaches have been developed to accurately characterize and measure VOCs in the laboratory, often from patient derived samples. Using these technological advancements it is evident that VOCs are indicative of both health and disease states. Many of these techniques are still largely confined to the research laboratory, but it is envisaged that in future bedside 'VOC profiling' will enable rapid characterization of microbial associated disease, providing vital information to healthcare practitioners.
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Affiliation(s)
- Robin Michael Statham Thorn
- Centre for Research in Biomedicine, Department of Applied Sciences, University of the West of England, Bristol, Frenchay Campus, Coldharbour Lane, BS16 1QY, UK
| | - John Greenman
- Centre for Research in Biomedicine, Department of Applied Sciences, University of the West of England, Bristol, Frenchay Campus, Coldharbour Lane, BS16 1QY, UK
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15
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Liu M, Nauta A, Francke C, Siezen RJ. Comparative genomics of enzymes in flavor-forming pathways from amino acids in lactic acid bacteria. Appl Environ Microbiol 2008; 74:4590-600. [PMID: 18539796 PMCID: PMC2519355 DOI: 10.1128/aem.00150-08] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Mengjin Liu
- Centre for Molecular and Biomolecular Informatics, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
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Percudani R, Peracchi A. A genomic overview of pyridoxal-phosphate-dependent enzymes. EMBO Rep 2003; 4:850-4. [PMID: 12949584 PMCID: PMC1326353 DOI: 10.1038/sj.embor.embor914] [Citation(s) in RCA: 371] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2003] [Accepted: 06/16/2003] [Indexed: 11/10/2022] Open
Abstract
Enzymes that use the cofactor pyridoxal phosphate (PLP) constitute a ubiquitous class of biocatalysts. Here, we analyse their variety and genomic distribution as an example of the current opportunities and challenges for the study of protein families. In many free-living prokaryotes, almost 1.5% of all genes code for PLP-dependent enzymes, but in higher eukaryotes the percentage is substantially lower, consistent with these catalysts being involved mainly in basic metabolism. Assigning the function of PLP-dependent enzymes simply on the basis of sequence criteria is not straightforward because, as a consequence of their common mechanistic features, these enzymes have intricate evolutionary relationships. Thus, many genes for PLP-dependent enzymes remain functionally unclassified, and several of them might encode undescribed catalytic activities. In addition, PLP-dependent enzymes often show catalytic promiscuity (that is, a single enzyme catalyses different reactions), implying that an organism can have more PLP-dependent activities than it has genes for PLP-dependent enzymes. This observation presumably applies to many other classes of protein-encoding genes.
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Affiliation(s)
- Riccardo Percudani
- Department of Biochemistry
and Molecular Biology, University of Parma, Parco Area delle Scienze
23/a, 43100 Parma, Italy
| | - Alessio Peracchi
- Department of Biochemistry
and Molecular Biology, University of Parma, Parco Area delle Scienze
23/a, 43100 Parma, Italy
- Tel: +39 521905137; Fax: +39 521905151;
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