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Masset Z, Gunaratnam S, Millette M, McFarland LV, Lacroix M. Environmental and Nutritional Parameters Modulating Genetic Expression for Virulence Factors of Clostridioides difficile. Antibiotics (Basel) 2024; 13:365. [PMID: 38667041 PMCID: PMC11047382 DOI: 10.3390/antibiotics13040365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/09/2024] [Accepted: 04/11/2024] [Indexed: 04/29/2024] Open
Abstract
Clostridioides difficile infections (CDIs) continue to be a persistent healthcare concern despite newer antibiotic treatments, enhanced infection control practices, and preventive strategies focused on restoring the protective intestinal microbial barrier. Recent strides in gene sequencing research have identified many genes regulating diverse virulence factors for CDIs. These genes may be over- or under-expressed when triggered by various environmental and nutritional factors. The aims of this paper are to review the important genes involved in C. difficile pathogenesis and to identify modifiable environmental, nutritional, and other factors that may trigger the expression of these genes and thus offer new strategies to prevent CDIs.
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Affiliation(s)
- Zoe Masset
- INRS Armand-Frappier Health Biotechnology Research Centre, Research Laboratories in Sciences, 531 des Prairies Blvd, Laval, QC H7V 1B7, Canada; (Z.M.); (M.L.)
| | - Sathursha Gunaratnam
- Bio-K+, a Kerry Company, Preclinical Research Division, 495 Armand-Frappier Blvd, Laval, QC H7V 4B3, Canada; (S.G.); (M.M.)
| | - Mathieu Millette
- Bio-K+, a Kerry Company, Preclinical Research Division, 495 Armand-Frappier Blvd, Laval, QC H7V 4B3, Canada; (S.G.); (M.M.)
| | - Lynne V. McFarland
- Public Health Reserves Corps, Seattle, WA 98115, USA
- McFarland Consulting, Seattle, WA 98115, USA
| | - Monique Lacroix
- INRS Armand-Frappier Health Biotechnology Research Centre, Research Laboratories in Sciences, 531 des Prairies Blvd, Laval, QC H7V 1B7, Canada; (Z.M.); (M.L.)
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Wan S, You P, Shi Q, Hu H, Zhang L, Chen L, Wu Z, Lin S, Song X, Luo Y, Wang Y, Ju F, Jin D, Chen Y. Gut microbiome changes in mouse, Mongolian gerbil, and hamster models following Clostridioides difficile challenge. Front Microbiol 2024; 15:1368194. [PMID: 38638911 PMCID: PMC11024471 DOI: 10.3389/fmicb.2024.1368194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 03/11/2024] [Indexed: 04/20/2024] Open
Abstract
Introduction Clostridioides difficile infection (CDI), as well as its etiology and pathogenesis, have been extensively investigated. However, the absence of suitable CDI animal models that reflect CDI symptoms and the associated gut microbiome changes in humans has limited research progress in this field. Thus, we aimed to investigate whether Mongolian gerbils, which present a range of human pathological conditions, can been used in studies on CDI. Methods: In this study, we infected Mongolian gerbils and two existing CDI model animals, mice and hamsters, with the hypervirulent ribotype 027 C. difficile strain, and comparatively analyzed changes in their gut microbiome composition via 16S rRNA gene sequencing. Methods In this study, we infected Mongolian gerbils and two existing CDI model animals, mice and hamsters, with the hypervirulent ribotype 027 C. difficile strain, and comparatively analyzed changes in their gut microbiome composition via 16S rRNA gene sequencing. Results The results obtained showed that C. difficile colonized the gastrointestinal tracts of the three rodents, and after the C. difficile challenge, C57BL/6J mice did not manifest CDI symptoms and their intestines showed no significant pathological changes. However, the hamsters showed explosive intestinal bleeding and inflammation and the Mongolian gerbils presented diarrhea as well as increased infiltration of inflammatory cells, mucus secretion, and epithelial cell shedding in their intestinal tissue. Further, intestinal microbiome analysis revealed significant differences with respect to intestinal flora abundance and diversity. Specifically, after C. difficile challenge, the Firmicutes/Bacteroidetes ratio decreased for C57BL/6J mice, but increased significantly for Mongolian gerbils and hamsters. Furthermore, the abundance of Proteobacteria increased in all three models, especially in hamsters, while that of Verrucomicrobia only increased significantly in C57BL/6J mice and Mongolian gerbils. Our results also indicated that differences in the relative abundances of Lactobacillaceae and Akkermansia were primarily responsible for the observed differences in response to C. difficile challenge. Conclusion Based on the observed responses to C. difficile challenge, we concluded for the first time that the Mongolian gerbil could be used as an animal model for CDI. Additionally, the taxa identified in this study may be used as biomarkers for further studies on CDI and to improve understanding regarding changes in gut microbiome in CDI-related diseases.
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Affiliation(s)
- Shuangshuang Wan
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
| | - Peijun You
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
| | - Qikai Shi
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
| | - Hui Hu
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
| | - Lu Zhang
- Environmental Microbiome and Biotechnology Laboratory, School of Engineering, Westlake University, Hangzhou, China
| | - Leyang Chen
- School of Clinical Medicine, Hangzhou Medical College, Hangzhou, China
| | - Ziyi Wu
- School of Clinical Medicine, Hangzhou Medical College, Hangzhou, China
| | - Shan Lin
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
| | - Xiaojun Song
- Laboratory Medicine Center, Department of Clinical Laboratory, Zhejiang Provincial People’s Hospital, Hangzhou Medical College, Hangzhou, China
| | - Yongneng Luo
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
| | - Yaxuan Wang
- National Center for Clinical Laboratories, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology, Beijing, China
| | - Feng Ju
- Environmental Microbiome and Biotechnology Laboratory, School of Engineering, Westlake University, Hangzhou, China
| | - Dazhi Jin
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
| | - Yu Chen
- School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
- Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, China
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Johnstone MA, Holman MA, Self WT. Inhibition of selenoprotein synthesis is not the mechanism by which auranofin inhibits growth of Clostridioides difficile. Sci Rep 2023; 13:14733. [PMID: 37679389 PMCID: PMC10484987 DOI: 10.1038/s41598-023-36796-9] [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] [Received: 10/07/2022] [Accepted: 06/12/2023] [Indexed: 09/09/2023] Open
Abstract
Clostridioides difficile infections (CDIs) are responsible for a significant number of antibiotic-associated diarrheal cases. The standard-of-care antibiotics for C. difficile are limited to fidaxomicin and vancomycin, with the recently obsolete metronidazole recommended if both are unavailable. No new antimicrobials have been approved for CDI since fidaxomicin in 2011, despite varying rates of treatment failure among all standard-of-care drugs. Drug repurposing is a rational strategy to generate new antimicrobials out of existing therapeutics approved for other indications. Auranofin is a gold-containing anti-rheumatic drug with antimicrobial activity against C. difficile and other microbes. In a previous report, our group hypothesized that inhibition of selenoprotein biosynthesis was auranofin's primary mechanism of action against C. difficile. However, in this study, we discovered that C. difficile mutants lacking selenoproteins are still just as sensitive to auranofin as their respective wild-type strains. Moreover, we found that selenite supplementation dampens the activity of auranofin against C. difficile regardless of the presence of selenoproteins, suggesting that selenite's neutralization of auranofin is not because of compensation for a chemically induced selenium deficiency. Our results clarify the findings of our original study and may aid drug repurposing efforts in discovering the compound's true mechanism of action against C. difficile.
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Affiliation(s)
- Michael A Johnstone
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, 4110 Libra Drive, Orlando, FL, 32816, USA
| | - Matthew A Holman
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, 4110 Libra Drive, Orlando, FL, 32816, USA
| | - William T Self
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, 4110 Libra Drive, Orlando, FL, 32816, USA.
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Hamiot A, Lemy C, Krzewinski F, Faille C, Dubois T. Sporulation conditions influence the surface and adhesion properties of Bacillus subtilis spores. Front Microbiol 2023; 14:1219581. [PMID: 37720141 PMCID: PMC10502511 DOI: 10.3389/fmicb.2023.1219581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 08/14/2023] [Indexed: 09/19/2023] Open
Abstract
Spore-forming bacteria of the Bacillus subtilis group are responsible for recurrent contamination of processing lines in the food industry which can lead to food spoilage. The persistence of B. subtilis would be due to the high resistance of spores to extreme environmental condition and their propensity to contaminate surfaces. While it is well known that sporulation conditions modulate spore resistance properties, little is known about their effect on surface and adhesion properties. Here, we studied the impact of 13 sporulation conditions on the surface and adhesion properties of B. subtilis 168 spores. We showed that Ca2+ or Mg2+ depletion, lower oxygen availability, acidic pH as well as oxidative stresses during sporulation lead to the release of more hydrophobic and adherent spores. The consequences of these sporulation conditions on crust composition in carbohydrates and proteins were also evaluated. The crust glycans of spores produced in a sporulation medium depleted in Ca2+ or Mg2+ or oxygen-limited conditions were impaired and contained lower amounts of rhamnose and legionaminic acid. In addition, we showed that lower oxygen availability or addition of hydrogen peroxide during sporulation decreases the relative amount of two crust proteins (CgeA and CotY) and the changes observed in these conditions could be due to transcriptional repression of genes involved in crust synthesis in late stationary phase. The fact that sporulation conditions affect the ease with which spores can contaminate surfaces could explain the frequent and recurrent presence of B. subtilis spores in food processing lines.
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Affiliation(s)
- Audrey Hamiot
- Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, Lille, France
| | - Christelle Lemy
- Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, Lille, France
| | - Frederic Krzewinski
- Univ. Lille, CNRS, UMR 8576 - UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Christine Faille
- Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, Lille, France
| | - Thomas Dubois
- Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, Lille, France
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5
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Wetzel D, Rizvi A, Edwards AN, McBride SM. The predicted acetoin dehydrogenase pathway represses sporulation of Clostridioides difficile. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.28.551048. [PMID: 37546766 PMCID: PMC10402147 DOI: 10.1101/2023.07.28.551048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Clostridioides difficile is a major gastrointestinal pathogen that is transmitted as a dormant spore. As an intestinal pathogen, C. difficile must contend with variable environmental conditions, including fluctuations in pH and nutrient availability. Nutrition and pH both influence growth and spore formation, but how pH and nutrition jointly influence sporulation are not known. In this study, we investigated the dual impact of pH and pH-dependent metabolism on C. difficile sporulation. Specifically, we examined the impacts of pH and the metabolite acetoin on C. difficile growth and sporulation. We found that expression of the predicted acetoin dehydrogenase operon, acoRABCL , was pH-dependent and regulated by acetoin. Regulation of the C. difficile aco locus is distinct from other characterized systems and appears to involve a co-transcribed DeoR-family regulator rather than the sigma 54 -dependent activator. In addition, an acoA null mutant produced significantly more spores and initiated sporulation earlier than the parent strain. However, unlike other Firmicutes, growth and culture density of C. difficile was not increased by acetoin availability or disruption of the aco pathway. Together, these results indicate that acetoin, pH, and the aco pathway play important roles in nutritional repression of sporulation in C. difficile , but acetoin metabolism does not support cell growth as a stationary phase energy source. IMPORTANCE Clostridioides difficile, or C. diff , is an anaerobic bacterium that lives within the gut of many mammals and causes infectious diarrhea. C. difficile is able to survive outside of the gut and transmit to new hosts by forming dormant spores. It is known that the pH of the intestine and the nutrients available both affect the growth and sporulation of C. diffiicile, but the specific conditions that result in sporulation in the host are not clear. In this study, we investigated how pH and the metabolite acetoin affect the ability of C. difficile to grow, proliferate, and form spores. We found that a mutant lacking the predicted acetoin metabolism pathway form more spores, but their growth is not impacted. These results show that C. difficile uses acetoin differently than many other species and that acetoin has an important role as an environmental metabolite that influences spore formation.
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Dupuy B. Regulation of Clostridial Toxin Gene Expression: A Pasteurian Tradition. Toxins (Basel) 2023; 15:413. [PMID: 37505682 PMCID: PMC10467148 DOI: 10.3390/toxins15070413] [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] [Received: 05/09/2023] [Revised: 06/13/2023] [Accepted: 06/19/2023] [Indexed: 07/29/2023] Open
Abstract
The alarming symptoms attributed to several potent clostridial toxins enabled the early identification of the causative agent of tetanus, botulism, and gas gangrene diseases, which belongs to the most famous species of pathogenic clostridia. Although Clostridioides difficile was identified early in the 20th century as producing important toxins, it was identified only 40 years later as the causative agent of important nosocomial diseases upon the advent of antibiotic therapies in hospital settings. Today, C. difficile is a leading public health issue, as it is the major cause of antibiotic-associated diarrhea in adults. In particular, severe symptoms within the spectrum of C. difficile infections are directly related to the levels of toxins produced in the host. This highlights the importance of understanding the regulation of toxin synthesis in the pathogenicity process of C. difficile, whose regulatory factors in response to the gut environment were first identified at the Institut Pasteur. Subsequently, the work of other groups in the field contributed to further deciphering the complex mechanisms controlling toxin production triggered by the intestinal dysbiosis states during infection. This review summarizes the Pasteurian contribution to clostridial toxin regulation studies.
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Affiliation(s)
- Bruno Dupuy
- Institut Pasteur, Université Paris-Cité, UMR-CNRS 6047, Laboratoire Pathogenèse des Bactéries Anaérobies, F-75015 Paris, France
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7
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Hromada S, Venturelli OS. Gut microbiota interspecies interactions shape the response of Clostridioides difficile to clinically relevant antibiotics. PLoS Biol 2023; 21:e3002100. [PMID: 37167201 PMCID: PMC10174544 DOI: 10.1371/journal.pbio.3002100] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 03/30/2023] [Indexed: 05/13/2023] Open
Abstract
In the human gut, the growth of the pathogen Clostridioides difficile is impacted by a complex web of interspecies interactions with members of human gut microbiota. We investigate the contribution of interspecies interactions on the antibiotic response of C. difficile to clinically relevant antibiotics using bottom-up assembly of human gut communities. We identify 2 classes of microbial interactions that alter C. difficile's antibiotic susceptibility: interactions resulting in increased ability of C. difficile to grow at high antibiotic concentrations (rare) and interactions resulting in C. difficile growth enhancement at low antibiotic concentrations (common). Based on genome-wide transcriptional profiling data, we demonstrate that metal sequestration due to hydrogen sulfide production by the prevalent gut species Desulfovibrio piger increases the minimum inhibitory concentration (MIC) of metronidazole for C. difficile. Competition with species that display higher sensitivity to the antibiotic than C. difficile leads to enhanced growth of C. difficile at low antibiotic concentrations due to competitive release. A dynamic computational model identifies the ecological principles driving this effect. Our results provide a deeper understanding of ecological and molecular principles shaping C. difficile's response to antibiotics, which could inform therapeutic interventions.
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Affiliation(s)
- Susan Hromada
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Ophelia S. Venturelli
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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8
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Chandra H, Sorg JA, Hassett DJ, Sun X. Regulatory transcription factors of Clostridioides difficile pathogenesis with a focus on toxin regulation. Crit Rev Microbiol 2023; 49:334-349. [PMID: 35389761 PMCID: PMC11209739 DOI: 10.1080/1040841x.2022.2054307] [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: 05/11/2021] [Revised: 02/26/2022] [Accepted: 03/14/2022] [Indexed: 11/03/2022]
Abstract
Clostridioides difficile (CD), a nosocomial gut pathogen, produces two major exotoxins, TcdA and TcdB, which disrupt the gut epithelial barrier and induce inflammatory/immune responses, leading to symptoms ranging from mild diarrhoea to pseudomembranous colitis and potentially to death. The expression of toxins is regulated by various transcription factors (TFs) which are induced in response to CD physiological life stages, nutritional availability, and host environment. This review summarises our current understanding on the regulation of toxin expression by TFs that interconnect with pathways of flagellar synthesis, quorum sensing, motility, biofilm formation, sporulation, and phase variation. The pleiotropic roles of some key TFs suggest that toxin production is tightly linked to other cellular processes of the CD physiology.
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Affiliation(s)
- Harish Chandra
- Department of Environmental Microbiology, School of Environmental and Earth Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, India
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Joseph A. Sorg
- Department of Biology, Texas A&M University, College Station, TX, USA
| | - Daniel J Hassett
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Xingmin Sun
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
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9
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Forster ER, Yang X, Tai AK, Hang HC, Shen A. Identification of a Bile Acid-Binding Transcription Factor in Clostridioides difficile Using Chemical Proteomics. ACS Chem Biol 2022; 17:3086-3099. [PMID: 36279369 PMCID: PMC10518218 DOI: 10.1021/acschembio.2c00463] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Clostridioides difficile is a Gram-positive anaerobic bacterium that is the leading cause of hospital-acquired gastroenteritis in the US. In the gut milieu, C. difficile encounters microbiota-derived, growth-inhibiting bile acids that are thought to be a significant mechanism of colonization resistance. While the levels of certain bile acids in the gut correlate with susceptibility to C. difficile infection, their molecular targets in C. difficile remain unknown. In this study, we sought to use chemical proteomics to identify bile acid-interacting proteins in C. difficile. Using photoaffinity bile acid probes and chemical proteomics, we identified a previously uncharacterized MerR family protein, CD3583 (now BapR), as a putative bile acid-sensing transcription regulator. Our data indicate that BapR specifically binds to and is stabilized by lithocholic acid (LCA) in C. difficile. Although loss of BapR did not affect C. difficile's sensitivity to LCA, ΔbapR cells elongated more in the presence of LCA compared to wild-type cells. Transcriptomics revealed that BapR regulates several gene clusters, with the expression of the mdeA-cd3573 locus being specifically de-repressed in the presence of LCA in a BapR-dependent manner. Electrophoretic mobility shift assays revealed that BapR directly binds to the mdeA promoter region. Because mdeA is involved in amino acid-related sulfur metabolism and the mdeA-cd3573 locus encodes putative transporters, we propose that BapR senses a gastrointestinal tract-specific small molecule, LCA, as an environmental cue for metabolic adaptation.
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Affiliation(s)
- Emily R Forster
- Graduate School of Biomedical Sciences, Tufts University, Boston, Massachusetts 02111, United States
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, United States
| | - Xinglin Yang
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California 92037, United States
| | - Albert K Tai
- Department of Immunology, Tufts University School of Medicine, Boston, Massachusetts 02111, United States
- Data Intensive Studies Center, Tufts University, Medford, Massachusetts 02155, United States
| | - Howard C Hang
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California 92037, United States
- Department of Chemistry, Scripps Research, La Jolla, California 92037, United States
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, United States
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Santos AMD, Costa JM, Braga JK, Flynn TM, Brucha G, Sancinetti GP, Rodriguez RP. Lactate as an effective electron donor in the sulfate reduction: impacts on the microbial diversity. ENVIRONMENTAL TECHNOLOGY 2022; 43:3149-3160. [PMID: 33840369 DOI: 10.1080/09593330.2021.1916092] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 04/05/2021] [Indexed: 06/12/2023]
Abstract
The competition between sulfate-reducing bacteria and methane-producing archaea has a major influence on organic matter removal, as well as the success of sulfidogenic systems. This study investigated the performance of six batch sulfidogenic reactors in response to different COD/sulfate ratios (1.0 and 2.0) and electron donors (cheese whey, ethanol, and sodium lactate) by evaluating the biochemical mechanisms of sulfate reduction, organic matter oxidation, and microbial structure modification. A COD/sulfate ratio of 1.0 resulted in high sulfidogenic activity for all electron donors, thereby achieving a nearly 80% sulfate removal. Lactate provided high sulfate removal rates at COD/sulfate ratios of 1.0 (80%) and 2.0 (90%). A COD/sulfate ratio of 2.0 decreased the sulfate removal rates by 25 and 28% when ethanol and cheese whey were used as substrates. The sulfate-reducing bacteria populations increased using ethanol and lactate at a COD/sulfate ratio of 1.0. Particularly, Desulfovibrio, Clostridium, and Syntrophobacter were predominant. Influent composition and COD/sulfate ratio influenced the relative abundance of the microbial communities. Therefore, controlling these parameters may facilitate the wastewater treatment with high sulfate levels through bacterial activity.
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Affiliation(s)
- Angélica Marcia Dos Santos
- Fundação Getúlio Vargas (FGV-Energia), Rio de Janeiro, Brazil
- Federal University of Catalão (UFCAT), Catalão, Brazil
- Laboratory of Anaerobic Biotechnology - Science and Technology Institute, Federal University of Alfenas (UNIFAL-MG), Poços de Caldas, Brazil
| | | | - Juliana Kawanishi Braga
- Laboratory of Anaerobic Biotechnology - Science and Technology Institute, Federal University of Alfenas (UNIFAL-MG), Poços de Caldas, Brazil
| | - Theodore M Flynn
- California Department of Water Resources, West Sacramento, CA, USA
| | - Gunther Brucha
- Laboratory of Anaerobic Biotechnology - Science and Technology Institute, Federal University of Alfenas (UNIFAL-MG), Poços de Caldas, Brazil
| | - Giselle Patricia Sancinetti
- Laboratory of Anaerobic Biotechnology - Science and Technology Institute, Federal University of Alfenas (UNIFAL-MG), Poços de Caldas, Brazil
| | - Renata Piacentini Rodriguez
- Laboratory of Anaerobic Biotechnology - Science and Technology Institute, Federal University of Alfenas (UNIFAL-MG), Poços de Caldas, Brazil
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Reconsidering the in vivo functions of Clostridial Stickland amino acid fermentations. Anaerobe 2022; 76:102600. [PMID: 35709938 PMCID: PMC9831356 DOI: 10.1016/j.anaerobe.2022.102600] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/03/2022] [Indexed: 01/13/2023]
Abstract
Stickland amino acid fermentations occur primarily among species of Clostridia. An ancient form of metabolism, Stickland fermentations use amino acids as electron acceptors in the absence of stronger oxidizing agents and provide metabolic capabilities to support growth when other fermentable substrates, such as carbohydrates, are lacking. The reactions were originally described as paired fermentations of amino acid electron donors, such as the branched-chain amino acids, with recipients that include proline and glycine. We present a redox-focused view of Stickland metabolism following electron flow through metabolically diverse oxidative reactions and the defined-substrate reductase systems, including for proline and glycine, and the role of dual redox pathways for substrates such as leucine and ornithine. Genetic studies and Environment and Gene Regulatory Interaction Network (EGRIN) models for the pathogen Clostridioides difficile have improved our understanding of the regulation and metabolic recruitment of these systems, and their functions in modulating inter-species interactions within host-pathogen-commensal systems and uses in industrial and environmental applications.
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12
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Biwer P, Neumann-Schaal M, Henke P, Jahn D, Schulz S. Thiol Metabolism and Volatile Metabolome of Clostridioides difficile. Front Microbiol 2022; 13:864587. [PMID: 35783419 PMCID: PMC9243749 DOI: 10.3389/fmicb.2022.864587] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/22/2022] [Indexed: 11/21/2022] Open
Abstract
Clostridioides difficile (previously Clostridium difficile) causes life-threatening gut infections. The central metabolism of the bacterium is strongly influencing toxin production and consequently the infection progress. In this context, the composition and potential origin of the volatile metabolome was investigated, showing a large number of sulfur-containing volatile metabolites. Gas chromatography/mass spectrometry (GC/MS)-based headspace analyses of growing C. difficile 630Δerm cultures identified 105 mainly sulfur-containing compounds responsible of the typical C. difficile odor. Major components were identified to be 2-methyl-1-propanol, 2-methyl-1-propanethiol, 2-methyl-1-butanethiol, 4-methyl-1-pentanethiol, and as well as their disulfides. Structurally identified were 64 sulfur containing volatiles. In order to determine their biosynthetic origin, the concentrations of the sulfur-containing amino acids methionine and cysteine were varied in the growth medium. The changes observed in the volatile metabolome profile indicated that cysteine plays an essential role in the formation of the sulfur-containing volatiles. We propose that disulfides are derived from cysteine via formation of cystathionine analogs, which lead to corresponding thiols. These thiols may then be oxidized to disulfides. Moreover, methionine may contribute to the formation of short-chain disulfides through integration of methanethiol into the disulfide biosynthesis. In summary, the causative agents of the typical C. difficile odor were identified and first hypotheses for their biosynthesis were proposed.
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Affiliation(s)
- Peter Biwer
- Institute of Organic Chemistry, Technische Universität Braunschweig, Braunschweig, Germany
| | - Meina Neumann-Schaal
- Department of Metabolomics, Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
- Braunschweig Integrated Centre of Systems Biology, BRICS, Braunschweig, Germany
| | - Petra Henke
- Department of Metabolomics, Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Dieter Jahn
- Braunschweig Integrated Centre of Systems Biology, BRICS, Braunschweig, Germany
- Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Stefan Schulz
- Institute of Organic Chemistry, Technische Universität Braunschweig, Braunschweig, Germany
- *Correspondence: Stefan Schulz,
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13
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Strain R, Stanton C, Ross RP. Effect of diet on pathogen performance in the microbiome. MICROBIOME RESEARCH REPORTS 2022; 1:13. [PMID: 38045644 PMCID: PMC10688830 DOI: 10.20517/mrr.2021.10] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 02/17/2022] [Accepted: 02/23/2022] [Indexed: 12/05/2023]
Abstract
Intricate interactions among commensal bacteria, dietary substrates and immune responses are central to defining microbiome community composition, which plays a key role in preventing enteric pathogen infection, a dynamic phenomenon referred to as colonisation resistance. However, the impact of diet on sculpting microbiota membership, and ultimately colonisation resistance has been overlooked. Furthermore, pathogens have evolved strategies to evade colonisation resistance and outcompete commensal microbiota by using unique nutrient utilisation pathways, by exploiting microbial metabolites as nutrient sources or by environmental cues to induce virulence gene expression. In this review, we will discuss the interplay between diet, microbiota and their associated metabolites, and how these can contribute to or preclude pathogen survival.
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Affiliation(s)
- Ronan Strain
- APC Microbiome Ireland, Biosciences Institute, University College Cork, Cork T12 YT20, Ireland
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork P61 C996, Ireland
| | - Catherine Stanton
- APC Microbiome Ireland, Biosciences Institute, University College Cork, Cork T12 YT20, Ireland
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork P61 C996, Ireland
| | - R. Paul Ross
- APC Microbiome Ireland, Biosciences Institute, University College Cork, Cork T12 YT20, Ireland
- School of Microbiology, University College Cork, College Road, Cork T12 K8AF, Ireland
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14
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Regulation of Clostridioides difficile toxin production. Curr Opin Microbiol 2022; 65:95-100. [PMID: 34781095 PMCID: PMC8792210 DOI: 10.1016/j.mib.2021.10.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/19/2021] [Accepted: 10/25/2021] [Indexed: 02/03/2023]
Abstract
Clostridioides difficile produces toxins TcdA and TcdB during infection. Since the severity of the illness is directly correlated with the level of toxins produced, researchers have long been interested in the regulation mechanisms of toxin production. The advent of new genetics and mutagenesis technologies in C. difficile has allowed a slew of new investigations in the last decade, which considerably improved our understanding of this crucial regulatory network. The current body of work shows that the toxin regulatory network overlaps with the regulatory networks of sporulation, motility, and key metabolic pathways. This implies that toxin production is a complicated process initiated by bacteria in response to numerous host factors during infection. We summarize the existing knowledge about the toxin gene regulatory network here.
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15
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Tremblay YD, Dupuy B. The blueprint for building a biofilm the Clostridioides difficile way. Curr Opin Microbiol 2021; 66:39-45. [PMID: 34933207 DOI: 10.1016/j.mib.2021.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/25/2021] [Accepted: 12/06/2021] [Indexed: 11/27/2022]
Abstract
Clostridioides difficile is an opportunistic pathogen that causes by a high rate of recurrent infections. Persistence in the gastrointestinal tract is thought to be mediated by sporulation and/or biofilm formation. There is an increase interest in C. difficile biofilm formation and recent findings have provided a framework to model surface-attached biofilm formation. For in vitro biofilm formation, C. difficile must undergo a metabolic reprogramming as it enters stationary phase. This helps maintain long-term viability and increases responsiveness to signals leading to biofilm formation. Metabolic reprogramming and biofilm formation requires several regulatory factors and these overlap with the sporulation cascade. Despite recent advances, further research is needed to answer outstanding questions in the field.
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Affiliation(s)
- Yannick Dn Tremblay
- Institut Pasteur, Université de Paris, UMR-CNRS 2001, Laboratoire Pathogenèse des Bactéries Anaérobies, F-75015 Paris, France; Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Canada.
| | - Bruno Dupuy
- Institut Pasteur, Université de Paris, UMR-CNRS 2001, Laboratoire Pathogenèse des Bactéries Anaérobies, F-75015 Paris, France.
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16
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Metabolic adaption to extracellular pyruvate triggers biofilm formation in Clostridioides difficile. THE ISME JOURNAL 2021; 15:3623-3635. [PMID: 34155333 PMCID: PMC8630010 DOI: 10.1038/s41396-021-01042-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 06/09/2021] [Accepted: 06/11/2021] [Indexed: 02/06/2023]
Abstract
Clostridioides difficile infections are associated with gut microbiome dysbiosis and are the leading cause of hospital-acquired diarrhoea. The infectious process is strongly influenced by the microbiota and successful infection relies on the absence of specific microbiota-produced metabolites. Deoxycholate and short-chain fatty acids are microbiota-produced metabolites that limit the growth of C. difficile and protect the host against this infection. In a previous study, we showed that deoxycholate causes C. difficile to form strongly adherent biofilms after 48 h. Here, our objectives were to identify and characterize key molecules and events required for biofilm formation in the presence of deoxycholate. We applied time-course transcriptomics and genetics to identify sigma factors, metabolic processes and type IV pili that drive biofilm formation. These analyses revealed that extracellular pyruvate induces biofilm formation in the presence of deoxycholate. In the absence of deoxycholate, pyruvate supplementation was sufficient to induce biofilm formation in a process that was dependent on pyruvate uptake by the membrane protein CstA. In the context of the human gut, microbiota-generated pyruvate is a metabolite that limits pathogen colonization. Taken together our results suggest that pyruvate-induced biofilm formation might act as a key process driving C. difficile persistence in the gut.
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17
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Girinathan BP, DiBenedetto N, Worley JN, Peltier J, Arrieta-Ortiz ML, Immanuel SRC, Lavin R, Delaney ML, Cummins CK, Hoffman M, Luo Y, Gonzalez-Escalona N, Allard M, Onderdonk AB, Gerber GK, Sonenshein AL, Baliga NS, Dupuy B, Bry L. In vivo commensal control of Clostridioides difficile virulence. Cell Host Microbe 2021; 29:1693-1708.e7. [PMID: 34637781 DOI: 10.1016/j.chom.2021.09.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/26/2021] [Accepted: 09/16/2021] [Indexed: 12/23/2022]
Abstract
Leveraging systems biology approaches, we illustrate how metabolically distinct species of Clostridia protect against or worsen Clostridioides difficile infection in mice by modulating the pathogen's colonization, growth, and virulence to impact host survival. Gnotobiotic mice colonized with the amino acid fermenter Paraclostridium bifermentans survive infection with reduced disease severity, while mice colonized with the butyrate-producer, Clostridium sardiniense, succumb more rapidly. Systematic in vivo analyses revealed how each commensal alters the gut-nutrient environment to modulate the pathogen's metabolism, gene regulatory networks, and toxin production. Oral administration of P. bifermentans rescues conventional, clindamycin-treated mice from lethal C. difficile infection in a manner similar to that of monocolonized animals, thereby supporting the therapeutic potential of this commensal species. Our findings lay the foundation for mechanistically informed therapies to counter C. difficile disease using systems biology approaches to define host-commensal-pathogen interactions in vivo.
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Affiliation(s)
- Brintha P Girinathan
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Nicholas DiBenedetto
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Jay N Worley
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; National Center of Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA
| | - Johann Peltier
- Laboratoire Pathogenèse des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, 25-28 Rue du Dr. Roux, Institut Pasteur, 75015 Paris Cedex, France; Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, 91198, Gif-sur-yvette Cedex, France
| | | | | | - Richard Lavin
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Mary L Delaney
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Clinical Microbiology Laboratory, Department of Pathology, Brigham & Women's Hospital, Boston, MA 02115, USA
| | - Christopher K Cummins
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Maria Hoffman
- Center for Food Safety and Applied Nutrition, United States Food and Drug Administration, Department of Microbiology, College Park, MD 20740, USA
| | - Yan Luo
- Center for Food Safety and Applied Nutrition, United States Food and Drug Administration, Department of Microbiology, College Park, MD 20740, USA
| | - Narjol Gonzalez-Escalona
- Center for Food Safety and Applied Nutrition, United States Food and Drug Administration, Department of Microbiology, College Park, MD 20740, USA
| | - Marc Allard
- Center for Food Safety and Applied Nutrition, United States Food and Drug Administration, Department of Microbiology, College Park, MD 20740, USA
| | - Andrew B Onderdonk
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Clinical Microbiology Laboratory, Department of Pathology, Brigham & Women's Hospital, Boston, MA 02115, USA
| | - Georg K Gerber
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Harvard-MIT Health Sciences & Technology, Cambridge, MA 02139, USA
| | - Abraham L Sonenshein
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA
| | | | - Bruno Dupuy
- Laboratoire Pathogenèse des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, 25-28 Rue du Dr. Roux, Institut Pasteur, 75015 Paris Cedex, France
| | - Lynn Bry
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Clinical Microbiology Laboratory, Department of Pathology, Brigham & Women's Hospital, Boston, MA 02115, USA.
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18
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Arrieta-Ortiz ML, Immanuel SRC, Turkarslan S, Wu WJ, Girinathan BP, Worley JN, DiBenedetto N, Soutourina O, Peltier J, Dupuy B, Bry L, Baliga NS. Predictive regulatory and metabolic network models for systems analysis of Clostridioides difficile. Cell Host Microbe 2021; 29:1709-1723.e5. [PMID: 34637780 PMCID: PMC8595754 DOI: 10.1016/j.chom.2021.09.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/29/2021] [Accepted: 09/16/2021] [Indexed: 12/15/2022]
Abstract
We present predictive models for comprehensive systems analysis of Clostridioides difficile, the etiology of pseudomembranous colitis. By leveraging 151 published transcriptomes, we generated an EGRIN model that organizes 90% of C. difficile genes into a transcriptional regulatory network of 297 co-regulated modules, implicating genes in sporulation, carbohydrate transport, and metabolism. By advancing a metabolic model through addition and curation of metabolic reactions including nutrient uptake, we discovered 14 amino acids, diverse carbohydrates, and 10 metabolic genes as essential for C. difficile growth in the intestinal environment. Finally, we developed a PRIME model to uncover how EGRIN-inferred combinatorial gene regulation by transcription factors, such as CcpA and CodY, modulates essential metabolic processes to enable C. difficile growth relative to commensal colonization. The C. difficile interactive web portal provides access to these model resources to support collaborative systems-level studies of context-specific virulence mechanisms in C. difficile.
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Affiliation(s)
| | | | | | - Wei-Ju Wu
- Institute for Systems Biology, Seattle, WA 98109, USA
| | - Brintha P Girinathan
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Jay N Worley
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Nicholas DiBenedetto
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Olga Soutourina
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-yvette 91198, France
| | - Johann Peltier
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-yvette 91198, France
| | - Bruno Dupuy
- Laboratoire Pathogenèse des Bactéries anaérobies, Institut Pasteur, Université de Paris, UMR CNRS 2001, Paris 75015, France
| | - Lynn Bry
- Massachusetts Host-Microbiome Center, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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19
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Novel Drivers of Virulence in Clostridioides difficile Identified via Context-Specific Metabolic Network Analysis. mSystems 2021; 6:e0091921. [PMID: 34609164 PMCID: PMC8547418 DOI: 10.1128/msystems.00919-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The pathogen Clostridioides difficile causes toxin-mediated diarrhea and is the leading cause of hospital-acquired infection in the United States. Due to growing antibiotic resistance and recurrent infection, targeting C. difficile metabolism presents a new approach to combat this infection. Genome-scale metabolic network reconstructions (GENREs) have been used to identify therapeutic targets and uncover properties that determine cellular behaviors. Thus, we constructed C. difficile GENREs for a hypervirulent isolate (strain [str.] R20291) and a historic strain (str. 630), validating both with in vitro and in vivo data sets. Growth simulations revealed significant correlations with measured carbon source usage (positive predictive value [PPV] ≥ 92.7%), and single-gene deletion analysis showed >89.0% accuracy. Next, we utilized each GENRE to identify metabolic drivers of both sporulation and biofilm formation. Through contextualization of each model using transcriptomes generated from in vitro and infection conditions, we discovered reliance on the pentose phosphate pathway as well as increased usage of cytidine and N-acetylneuraminate when virulence expression is reduced, which was subsequently supported experimentally. Our results highlight the ability of GENREs to identify novel metabolite signals in higher-order phenotypes like bacterial pathogenesis. IMPORTANCE Clostridioides difficile has become the leading single cause of hospital-acquired infections. Numerous studies have demonstrated the importance of specific metabolic pathways in aspects of C. difficile pathophysiology, from initial colonization to regulation of virulence factors. In the past, genome-scale metabolic network reconstruction (GENRE) analysis of bacteria has enabled systematic investigation of the genetic and metabolic properties that contribute to downstream virulence phenotypes. With this in mind, we generated and extensively curated C. difficile GENREs for both a well-studied laboratory strain (str. 630) and a more recently characterized hypervirulent isolate (str. R20291). In silico validation of both GENREs revealed high degrees of agreement with experimental gene essentiality and carbon source utilization data sets. Subsequent exploration of context-specific metabolism during both in vitro growth and infection revealed consistent patterns of metabolism which corresponded with experimentally measured increases in virulence factor expression. Our results support that differential C. difficile virulence is associated with distinct metabolic programs related to use of carbon sources and provide a platform for identification of novel therapeutic targets.
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20
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Riedel T, Neumann-Schaal M, Wittmann J, Schober I, Hofmann JD, Lu CW, Dannheim A, Zimmermann O, Lochner M, Groß U, Overmann J. Characterization of Clostridioides difficile DSM 101085 with A-B-CDT+ Phenotype from a Late Recurrent Colonization. Genome Biol Evol 2021; 12:566-577. [PMID: 32302381 PMCID: PMC7250501 DOI: 10.1093/gbe/evaa072] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/10/2020] [Indexed: 12/29/2022] Open
Abstract
During the last decades, hypervirulent strains of Clostridioides difficile with frequent disease recurrence and increased mortality appeared. Clostridioides difficile DSM 101085 was isolated from a patient who suffered from several recurrent infections and colonizations, likely contributing to a fatal outcome. Analysis of the toxin repertoire revealed the presence of a complete binary toxin locus and an atypical pathogenicity locus consisting of only a tcdA pseudogene and a disrupted tcdC gene sequence. The pathogenicity locus shows upstream a transposon and has been subject to homologous recombination or lateral gene transfer events. Matching the results of the genome analysis, neither TcdA nor TcdB production but the expression of cdtA and cdtB was detected. This highlights a potential role of the binary toxin C. difficile toxin in this recurrent colonization and possibly further in a host-dependent virulence. Compared with the C. difficile metabolic model strains DSM 28645 (630Δerm) and DSM 27147 (R20291), strain DSM 101085 showed a specific metabolic profile, featuring changes in the threonine degradation pathways and alterations in the central carbon metabolism. Moreover, products originating from Stickland pathways processing leucine, aromatic amino acids, and methionine were more abundant in strain DSM 101085, indicating a more efficient use of these substrates. The particular characteristics of strain C. difficile DSM 101085 may represent an adaptation to a low-protein diet in a patient with recurrent infections.
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Affiliation(s)
- Thomas Riedel
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Braunschweig, Germany
| | - Meina Neumann-Schaal
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,Department of Bioinformatics and Biochemistry and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Germany
| | - Johannes Wittmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Isabel Schober
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Julia Danielle Hofmann
- Department of Bioinformatics and Biochemistry and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Germany
| | - Chia-Wen Lu
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, a Joint Venture between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Antonia Dannheim
- Department of Bioinformatics and Biochemistry and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Germany
| | - Ortrud Zimmermann
- Institute of Medical Microbiology, University Medical Center Göttingen, Germany
| | - Matthias Lochner
- Institute of Infection Immunology, TWINCORE, Centre for Experimental and Clinical Infection Research, a Joint Venture between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Uwe Groß
- Institute of Medical Microbiology, University Medical Center Göttingen, Germany.,Göttingen International Health Network, Göttingen, Germany
| | - Jörg Overmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Braunschweig, Germany.,Institute of Microbiology, Technical University of Braunschweig, Germany
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21
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Brauer M, Lassek C, Hinze C, Hoyer J, Becher D, Jahn D, Sievers S, Riedel K. What's a Biofilm?-How the Choice of the Biofilm Model Impacts the Protein Inventory of Clostridioides difficile. Front Microbiol 2021; 12:682111. [PMID: 34177868 PMCID: PMC8225356 DOI: 10.3389/fmicb.2021.682111] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/12/2021] [Indexed: 12/18/2022] Open
Abstract
The anaerobic pathogen Clostridioides difficile is perfectly equipped to survive and persist inside the mammalian intestine. When facing unfavorable conditions C. difficile is able to form highly resistant endospores. Likewise, biofilms are currently discussed as form of persistence. Here a comprehensive proteomics approach was applied to investigate the molecular processes of C. difficile strain 630Δerm underlying biofilm formation. The comparison of the proteome from two different forms of biofilm-like growth, namely aggregate biofilms and colonies on agar plates, revealed major differences in the formation of cell surface proteins, as well as enzymes of its energy and stress metabolism. For instance, while the obtained data suggest that aggregate biofilm cells express both flagella, type IV pili and enzymes required for biosynthesis of cell-surface polysaccharides, the S-layer protein SlpA and most cell wall proteins (CWPs) encoded adjacent to SlpA were detected in significantly lower amounts in aggregate biofilm cells than in colony biofilms. Moreover, the obtained data suggested that aggregate biofilm cells are rather actively growing cells while colony biofilm cells most likely severely suffer from a lack of reductive equivalents what requires induction of the Wood-Ljungdahl pathway and C. difficile’s V-type ATPase to maintain cell homeostasis. In agreement with this, aggregate biofilm cells, in contrast to colony biofilm cells, neither induced toxin nor spore production. Finally, the data revealed that the sigma factor SigL/RpoN and its dependent regulators are noticeably induced in aggregate biofilms suggesting an important role of SigL/RpoN in aggregate biofilm formation.
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Affiliation(s)
- Madita Brauer
- Department for Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Christian Lassek
- Department for Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Christian Hinze
- Department for Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Juliane Hoyer
- Department for Microbial Proteomics, Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Dörte Becher
- Department for Microbial Proteomics, Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Dieter Jahn
- Braunschweig Integrated Centre of Systems Biology (BRICS), Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Susanne Sievers
- Department for Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Katharina Riedel
- Department for Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, Greifswald, Germany
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22
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Göbbels L, Poehlein A, Dumnitch A, Egelkamp R, Kröger C, Haerdter J, Hackl T, Feld A, Weller H, Daniel R, Streit WR, Schoelmerich MC. Cysteine: an overlooked energy and carbon source. Sci Rep 2021; 11:2139. [PMID: 33495538 PMCID: PMC7835215 DOI: 10.1038/s41598-021-81103-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/31/2020] [Indexed: 11/09/2022] Open
Abstract
Biohybrids composed of microorganisms and nanoparticles have emerged as potential systems for bioenergy and high-value compound production from CO2 and light energy, yet the cellular and metabolic processes within the biological component of this system are still elusive. Here we dissect the biohybrid composed of the anaerobic acetogenic bacterium Moorella thermoacetica and cadmium sulphide nanoparticles (CdS) in terms of physiology, metabolism, enzymatics and transcriptomic profiling. Our analyses show that while the organism does not grow on l-cysteine, it is metabolized to acetate in the biohybrid system and this metabolism is independent of CdS or light. CdS cells have higher metabolic activity, despite an inhibitory effect of Cd2+ on key enzymes, because of an intracellular storage compound linked to arginine metabolism. We identify different routes how cysteine and its oxidized form can be innately metabolized by the model acetogen and what intracellular mechanisms are triggered by cysteine, cadmium or blue light.
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Affiliation(s)
- Luise Göbbels
- Microbiology and Biotechnology, Institute of Plant Sciences and Microbiology, University of Hamburg, 22609, Hamburg, Germany
| | - Anja Poehlein
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Georg-August University Göttingen, Grisebachstraße 8, 37077, Göttingen, Germany
| | - Albert Dumnitch
- Microbiology and Biotechnology, Institute of Plant Sciences and Microbiology, University of Hamburg, 22609, Hamburg, Germany
| | - Richard Egelkamp
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Georg-August University Göttingen, Grisebachstraße 8, 37077, Göttingen, Germany
| | - Cathrin Kröger
- Microbiology and Biotechnology, Institute of Plant Sciences and Microbiology, University of Hamburg, 22609, Hamburg, Germany
| | - Johanna Haerdter
- Institute of Organic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Thomas Hackl
- Institute of Organic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Artur Feld
- Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146, Hamburg, Germany
| | - Horst Weller
- Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146, Hamburg, Germany
| | - Rolf Daniel
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Georg-August University Göttingen, Grisebachstraße 8, 37077, Göttingen, Germany
| | - Wolfgang R Streit
- Microbiology and Biotechnology, Institute of Plant Sciences and Microbiology, University of Hamburg, 22609, Hamburg, Germany
| | - Marie Charlotte Schoelmerich
- Microbiology and Biotechnology, Institute of Plant Sciences and Microbiology, University of Hamburg, 22609, Hamburg, Germany.
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23
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Hofmann JD, Biedendieck R, Michel AM, Schomburg D, Jahn D, Neumann-Schaal M. Influence of L-lactate and low glucose concentrations on the metabolism and the toxin formation of Clostridioides difficile. PLoS One 2021; 16:e0244988. [PMID: 33411772 PMCID: PMC7790285 DOI: 10.1371/journal.pone.0244988] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 12/18/2020] [Indexed: 12/14/2022] Open
Abstract
The virulence of Clostridioides difficile (formerly Clostridium difficile) is mainly caused by its two toxins A and B. Their formation is significantly regulated by metabolic processes. Here we investigated the influence of various sugars (glucose, fructose, mannose, trehalose), sugar derivatives (mannitol and xylitol) and L-lactate on toxin synthesis. Fructose, mannose, trehalose, mannitol and xylitol in the growth medium resulted in an up to 2.2-fold increase of secreted toxin. Low glucose concentration of 2 g/L increased the toxin concentration 1.4-fold compared to growth without glucose, while high glucose concentrations in the growth medium (5 and 10 g/L) led to up to 6.6-fold decrease in toxin formation. Transcriptomic and metabolic investigation of the low glucose effect pointed towards an inactive CcpA and Rex regulatory system. L-lactate (500 mg/L) significantly reduced extracellular toxin formation. Transcriptome analyses of the later process revealed the induction of the lactose utilization operon encoding lactate racemase (larA), electron confurcating lactate dehydrogenase (CDIF630erm_01321) and the corresponding electron transfer flavoprotein (etfAB). Metabolome analyses revealed L-lactate consumption and the formation of pyruvate. The involved electron confurcation process might be responsible for the also observed reduction of the NAD+/NADH ratio which in turn is apparently linked to reduced toxin release from the cell.
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Affiliation(s)
- Julia Danielle Hofmann
- Department of Bioinformatics and Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
| | - Rebekka Biedendieck
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
- Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Annika-Marisa Michel
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
- Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Dietmar Schomburg
- Department of Bioinformatics and Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
| | - Dieter Jahn
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
- Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Meina Neumann-Schaal
- Department of Bioinformatics and Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
- Leibniz Institute DSMZ—German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
- * E-mail:
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24
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Neuwirth T, Letzel AC, Tank C, Ishida K, Cyrulies M, Schmölz L, Lorkowski S, Hertweck C. Induced Production, Synthesis, and Immunomodulatory Action of Clostrisulfone, a Diarylsulfone from Clostridium acetobutylicum. Chemistry 2020; 26:15855-15858. [PMID: 32996646 PMCID: PMC7756337 DOI: 10.1002/chem.202003500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/29/2020] [Indexed: 01/25/2023]
Abstract
The anaerobe Clostridium acetobutylicum belongs to the most important industrially used bacteria. Whereas genome mining points to a high potential for secondary metabolism in C. acetobutylicum, the functions of most biosynthetic gene clusters are cryptic. We report that the addition of supra‐physiological concentrations of cysteine triggered the formation of a novel natural product, clostrisulfone (1). Its structure was fully elucidated by NMR, MS and the chemical synthesis of a reference compound. Clostrisulfone is the first reported natural product with a diphenylsulfone scaffold. A biomimetic synthesis suggests that pentamethylchromanol‐derived radicals capture sulfur dioxide to form 1. In a cell‐based assay using murine macrophages a biphasic and dose‐dependent regulation of the LPS‐induced release of nitric oxide was observed in the presence of 1.
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Affiliation(s)
- Toni Neuwirth
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Chemistry and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Anne-Catrin Letzel
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Chemistry and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Cedric Tank
- BioPilotPlant, Leibniz Institute for Natural Product Chemistry and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Keishi Ishida
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Chemistry and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Michael Cyrulies
- BioPilotPlant, Leibniz Institute for Natural Product Chemistry and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Lisa Schmölz
- Institute of Nutritional Sciences, Friedrich Schiller University Jena, Dornburger Straße 25, 07743, Jena, Germany
| | - Stefan Lorkowski
- Institute of Nutritional Sciences, Friedrich Schiller University Jena, Dornburger Straße 25, 07743, Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Chemistry and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany.,Faculty of Biological Sciences, Friedrich Schiller University Jena, 07743, Jena, Germany
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25
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Engevik MA, Danhof HA, Shrestha R, Chang-Graham AL, Hyser JM, Haag AM, Mohammad MA, Britton RA, Versalovic J, Sorg JA, Spinler JK. Reuterin disrupts Clostridioides difficile metabolism and pathogenicity through reactive oxygen species generation. Gut Microbes 2020; 12:1788898. [PMID: 32804011 PMCID: PMC7524292 DOI: 10.1080/19490976.2020.1795388] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/16/2020] [Accepted: 07/06/2020] [Indexed: 02/03/2023] Open
Abstract
Antibiotic resistance is one of the world's greatest public health challenges and adjunct probiotic therapies are strategies that could lessen this burden. Clostridioides difficile infection (CDI) is a prime example where adjunct probiotic therapies could decrease disease incidence through prevention. Human-derived Lactobacillus reuteri is a probiotic that produces the antimicrobial compound reuterin known to prevent C. difficile colonization of antibiotic-treated fecal microbial communities. However, the mechanism of inhibition is unclear. We show that reuterin inhibits C. difficile outgrowth from spores and vegetative cell growth, however, no effect on C. difficile germination or sporulation was observed. Consistent with published studies, we found that exposure to reuterin stimulated reactive oxygen species (ROS) in C. difficile, resulting in a concentration-dependent reduction in cell viability that was rescued by the antioxidant glutathione. Sublethal concentrations of reuterin enhanced the susceptibility of vegetative C. difficile to vancomycin and metronidazole treatment and reduced toxin synthesis by C. difficile. We also demonstrate that reuterin is protective against C. difficile toxin-mediated cellular damage in the human intestinal enteroid model. Overall, our results indicate that ROS are essential mediators of reuterin activity and show that reuterin production by L. reuteri is compatible as a therapeutic in a clinically relevant model.
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Affiliation(s)
- Melinda A. Engevik
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
| | - Heather A. Danhof
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Ritu Shrestha
- Department of Biology, Texas A&M University, College Station, TX, USA
| | | | - Joseph M. Hyser
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Anthony M. Haag
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Texas Children’s Microbiome Center, Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
| | - Mahmoud A. Mohammad
- Department of Pediatrics, Children’s Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Robert A. Britton
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - James Versalovic
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
- Texas Children’s Microbiome Center, Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
| | - Joseph A. Sorg
- Department of Biology, Texas A&M University, College Station, TX, USA
| | - Jennifer K. Spinler
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
- Texas Children’s Microbiome Center, Department of Pathology, Texas Children’s Hospital, Houston, TX, USA
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26
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Diverse Energy-Conserving Pathways in Clostridium difficile: Growth in the Absence of Amino Acid Stickland Acceptors and the Role of the Wood-Ljungdahl Pathway. J Bacteriol 2020; 202:JB.00233-20. [PMID: 32967909 DOI: 10.1128/jb.00233-20] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/23/2020] [Indexed: 12/21/2022] Open
Abstract
Clostridium difficile is the leading cause of hospital-acquired antibiotic-associated diarrhea and is the only widespread human pathogen that contains a complete set of genes encoding the Wood-Ljungdahl pathway (WLP). In acetogenic bacteria, synthesis of acetate from 2 CO2 molecules by the WLP functions as a terminal electron accepting pathway; however, C. difficile contains various other reductive pathways, including a heavy reliance on Stickland reactions, which questions the role of the WLP in this bacterium. In rich medium containing high levels of electron acceptor substrates, only trace levels of key WLP enzymes were found; therefore, conditions were developed to adapt C. difficile to grow in the absence of amino acid Stickland acceptors. Growth conditions were identified that produce the highest levels of WLP activity, determined by Western blot analyses of the central component acetyl coenzyme A synthase (AcsB) and assays of other WLP enzymes. Fermentation substrate and product analyses, enzyme assays of cell extracts, and characterization of a ΔacsB mutant demonstrated that the WLP functions to dispose of metabolically generated reducing equivalents. While WLP activity in C. difficile does not reach the levels seen in classical acetogens, coupling of the WLP to butyrate formation provides a highly efficient system for regeneration of NAD+ "acetobutyrogenesis," requiring only low flux through the pathways to support efficient ATP production from glucose oxidation. Additional insights redefine the amino acid requirements in C. difficile, explore the relationship of the WLP to toxin production, and provide a rationale for colocalization of genes involved in glycine synthesis and cleavage within the WLP operon.IMPORTANCE Clostridium difficile is an anaerobic, multidrug-resistant, toxin-producing pathogen with major health impacts worldwide. It is the only widespread pathogen harboring a complete set of Wood-Ljungdahl pathway (WLP) genes; however, the role of the WLP in C. difficile is poorly understood. In other anaerobic bacteria and archaea, the WLP can operate in one direction to convert CO2 to acetic acid for biosynthesis or in either direction for energy conservation. Here, conditions are defined in which WLP levels in C. difficile increase markedly, functioning to support metabolism of carbohydrates. Amino acid nutritional requirements were better defined, with new insight into how the WLP and butyrate pathways act in concert, contributing significantly to energy metabolism by a mechanism that may have broad physiological significance within the group of nonclassical acetogens.
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27
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Transcriptomic analysis of a Clostridium thermocellum strain engineered to utilize xylose: responses to xylose versus cellobiose feeding. Sci Rep 2020; 10:14517. [PMID: 32884054 PMCID: PMC7471329 DOI: 10.1038/s41598-020-71428-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 08/10/2020] [Indexed: 12/20/2022] Open
Abstract
Clostridium (Ruminiclostridium) thermocellum is recognized for its ability to ferment cellulosic biomass directly, but it cannot naturally grow on xylose. Recently, C. thermocellum (KJC335) was engineered to utilize xylose through expressing a heterologous xylose catabolizing pathway. Here, we compared KJC335′s transcriptomic responses to xylose versus cellobiose as the primary carbon source and assessed how the bacteria adapted to utilize xylose. Our analyses revealed 417 differentially expressed genes (DEGs) with log2 fold change (FC) >|1| and 106 highly DEGs (log2 FC >|2|). Among the DEGs, two putative sugar transporters, cbpC and cbpD, were up-regulated, suggesting their contribution to xylose transport and assimilation. Moreover, the up-regulation of specific transketolase genes (tktAB) suggests the importance of this enzyme for xylose metabolism. Results also showed remarkable up-regulation of chemotaxis and motility associated genes responding to xylose feeding, as well as widely varying gene expression in those encoding cellulosomal enzymes. For the down-regulated genes, several were categorized in gene ontology terms oxidation–reduction processes, ATP binding and ATPase activity, and integral components of the membrane. This study informs potentially critical, enabling mechanisms to realize the conceptually attractive Next-Generation Consolidated BioProcessing approach where a single species is sufficient for the co-fermentation of cellulose and hemicellulose.
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28
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Clostridioides difficile para-Cresol Production Is Induced by the Precursor para-Hydroxyphenylacetate. J Bacteriol 2020; 202:JB.00282-20. [PMID: 32631945 PMCID: PMC7925072 DOI: 10.1128/jb.00282-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 06/24/2020] [Indexed: 12/12/2022] Open
Abstract
Clostridioides difficile is an etiological agent for antibiotic-associated diarrheal disease. C. difficile produces a phenolic compound, para-cresol, which selectively targets gammaproteobacteria in the gut, facilitating dysbiosis. C. difficile decarboxylates para-hydroxyphenylacetate (p-HPA) to produce p-cresol by the action of the HpdBCA decarboxylase encoded by the hpdBCA operon. Here, we investigate regulation of the hpdBCA operon and directly compare three independent reporter systems; SNAP-tag, glucuronidase gusA, and alkaline phosphatase phoZ reporters to detect basal and inducible expression. We show that expression of hpdBCA is upregulated in response to elevated p-HPA. In silico analysis identified three putative promoters upstream of hpdBCA operon-P1, P2, and Pσ54; only the P1 promoter was responsible for both basal and p-HPA-inducible expression of hpdBCA We demonstrated that turnover of tyrosine, a precursor for p-HPA, is insufficient to induce expression of the hpdBCA operon above basal levels because it is inefficiently converted to p-HPA in minimal media. We show that induction of the hpdBCA operon in response to p-HPA occurs in a dose-dependent manner. We also identified an inverted palindromic repeat (AAAAAG-N13-CTTTTT) upstream of the hpdBCA start codon (ATG) that is essential for inducing transcription of the hpdBCA operon in response to p-HPA, which drives the production of p-cresol. This provides insights into the regulatory control of p-cresol production, which affords a competitive advantage for C. difficile over other intestinal bacteria, promoting dysbiosis.IMPORTANCE Clostridioides difficile infection results from antibiotic-associated dysbiosis. para-Cresol, a phenolic compound produced by C. difficile, selectively targets gammaproteobacteria in the gut, facilitating dysbiosis. Here, we demonstrate that expression of the hpdBCA operon, encoding the HpdBCA decarboxylase which converts p-HPA to p-cresol, is upregulated in response to elevated exogenous p-HPA, with induction occurring between >0.1 and ≤0.25 mg/ml. We determined a single promoter and an inverted palindromic repeat responsible for basal and p-HPA-inducible hpdBCA expression. We identified turnover of tyrosine, a p-HPA precursor, does not induce hpdBCA expression above basal level, indicating that exogenous p-HPA was required for p-cresol production. Identifying regulatory controls of p-cresol production will provide novel therapeutic targets to prevent p-cresol production, reducing C. difficile's competitive advantage.
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29
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Soutourina O, Dubois T, Monot M, Shelyakin PV, Saujet L, Boudry P, Gelfand MS, Dupuy B, Martin-Verstraete I. Genome-Wide Transcription Start Site Mapping and Promoter Assignments to a Sigma Factor in the Human Enteropathogen Clostridioides difficile. Front Microbiol 2020; 11:1939. [PMID: 32903654 PMCID: PMC7438776 DOI: 10.3389/fmicb.2020.01939] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/23/2020] [Indexed: 12/12/2022] Open
Abstract
The emerging human enteropathogen Clostridioides difficile is the main cause of diarrhea associated with antibiotherapy. Regulatory pathways underlying the adaptive responses remain understudied and the global view of C. difficile promoter structure is still missing. In the genome of C. difficile 630, 22 genes encoding sigma factors are present suggesting a complex pattern of transcription in this bacterium. We present here the first transcriptional map of the C. difficile genome resulting from the identification of transcriptional start sites (TSS), promoter motifs and operon structures. By 5′-end RNA-seq approach, we mapped more than 1000 TSS upstream of genes. In addition to these primary TSS, this analysis revealed complex structure of transcriptional units such as alternative and internal promoters, potential RNA processing events and 5′ untranslated regions. By following an in silico iterative strategy that used as an input previously published consensus sequences and transcriptomic analysis, we identified candidate promoters upstream of most of protein-coding and non-coding RNAs genes. This strategy also led to refine consensus sequences of promoters recognized by major sigma factors of C. difficile. Detailed analysis focuses on the transcription in the pathogenicity locus and regulatory genes, as well as regulons of transition phase and sporulation sigma factors as important components of C. difficile regulatory network governing toxin gene expression and spore formation. Among the still uncharacterized regulons of the major sigma factors of C. difficile, we defined the SigL regulon by combining transcriptome and in silico analyses. We showed that the SigL regulon is largely involved in amino-acid degradation, a metabolism crucial for C. difficile gut colonization. Finally, we combined our TSS mapping, in silico identification of promoters and RNA-seq data to improve gene annotation and to suggest operon organization in C. difficile. These data will considerably improve our knowledge of global regulatory circuits controlling gene expression in C. difficile and will serve as a useful rich resource for scientific community both for the detailed analysis of specific genes and systems biology studies.
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Affiliation(s)
- Olga Soutourina
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France.,Institut Universitaire de France, Paris, France.,Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Thomas Dubois
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France
| | - Marc Monot
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France
| | | | - Laure Saujet
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France
| | - Pierre Boudry
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France
| | - Mikhail S Gelfand
- Institute for Information Transmission Problems, Moscow, Russia.,Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Bruno Dupuy
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France
| | - Isabelle Martin-Verstraete
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France.,Institut Universitaire de France, Paris, France
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30
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Mefferd CC, Bhute SS, Phan JR, Villarama JV, Do DM, Alarcia S, Abel-Santos E, Hedlund BP. A High-Fat/High-Protein, Atkins-Type Diet Exacerbates Clostridioides ( Clostridium) difficile Infection in Mice, whereas a High-Carbohydrate Diet Protects. mSystems 2020; 5:e00765-19. [PMID: 32047064 PMCID: PMC7018531 DOI: 10.1128/msystems.00765-19] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 01/29/2020] [Indexed: 02/06/2023] Open
Abstract
Clostridioides difficile (formerly Clostridium difficile) infection (CDI) can result from the disruption of the resident gut microbiota. Western diets and popular weight-loss diets drive large changes in the gut microbiome; however, the literature is conflicted with regard to the effect of diet on CDI. Using the hypervirulent strain C. difficile R20291 (RT027) in a mouse model of antibiotic-induced CDI, we assessed disease outcome and microbial community dynamics in mice fed two high-fat diets in comparison with a high-carbohydrate diet and a standard rodent diet. The two high-fat diets exacerbated CDI, with a high-fat/high-protein, Atkins-like diet leading to severe CDI and 100% mortality and a high-fat/low-protein, medium-chain-triglyceride (MCT)-like diet inducing highly variable CDI outcomes. In contrast, mice fed a high-carbohydrate diet were protected from CDI, despite the high levels of refined carbohydrate and low levels of fiber in the diet. A total of 28 members of the Lachnospiraceae and Ruminococcaceae decreased in abundance due to diet and/or antibiotic treatment; these organisms may compete with C. difficile for amino acids and protect healthy animals from CDI in the absence of antibiotics. Together, these data suggest that antibiotic treatment might lead to loss of C. difficile competitors and create a favorable environment for C. difficile proliferation and virulence with effects that are intensified by high-fat/high-protein diets; in contrast, high-carbohydrate diets might be protective regardless of the source of carbohydrate or of antibiotic-driven loss of C. difficile competitors.IMPORTANCE The role of Western and weight-loss diets with extreme macronutrient composition in the risk and progression of CDI is poorly understood. In a longitudinal study, we showed that a high-fat/high-protein, Atkins-type diet greatly exacerbated antibiotic-induced CDI, whereas a high-carbohydrate diet protected, despite the high monosaccharide and starch content. Our study results, therefore, suggest that popular high-fat/high-protein weight-loss diets may enhance CDI risk during antibiotic treatment, possibly due to the synergistic effects of a loss of the microorganisms that normally inhibit C. difficile overgrowth and an abundance of amino acids that promote C. difficile overgrowth. In contrast, a high-carbohydrate diet might be protective, despite reports on the recent evolution of enhanced carbohydrate metabolism in C. difficile.
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Affiliation(s)
| | - Shrikant S Bhute
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
| | - Jacqueline R Phan
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
| | - Jacob V Villarama
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
| | - Dung M Do
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
| | - Stephanie Alarcia
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
| | - Ernesto Abel-Santos
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
- Nevada Institute of Personalized Medicine, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
| | - Brian P Hedlund
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
- Nevada Institute of Personalized Medicine, University of Nevada, Las Vegas, Las Vegas, Nevada, USA
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31
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Abhyankar W, Zheng L, Brul S, de Koster CG, de Koning LJ. Vegetative Cell and Spore Proteomes of Clostridioides difficile Show Finite Differences and Reveal Potential Protein Markers. J Proteome Res 2019; 18:3967-3976. [PMID: 31557040 PMCID: PMC6832669 DOI: 10.1021/acs.jproteome.9b00413] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Indexed: 12/22/2022]
Abstract
Clostridioides difficile-associated infection (CDI) is a health-care-associated infection caused, as the name suggests, by obligate anaerobic pathogen C. difficile and thus mainly transmitted via highly resistant endospores from one person to the other. In vivo, the spores need to germinate into cells prior to establishing an infection. Bile acids and glycine, both available in sufficient amounts inside the human host intestinal tract, serve as efficient germinants for the spores. It is therefore, for better understanding of C. difficile virulence, crucial to study both the cell and spore states with respect to their genetic, metabolic, and proteomic composition. In the present study, mass spectrometric relative protein quantification, based on the 14N/15N peptide isotopic ratios, has led to quantification of over 700 proteins from combined spore and cell samples. The analysis has revealed that the proteome turnover between a vegetative cell and a spore for this organism is moderate. Additionally, specific cell and spore surface proteins, vegetative cell proteins CD1228, CD3301 and spore proteins CD2487, CD2434, and CD0684 are identified as potential protein markers for C. difficile infection.
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Affiliation(s)
- Wishwas
R. Abhyankar
- Department
of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam Faculty
of Science, Science Park 904, 1098 XH Amsterdam, The Netherlands
- Department
of Mass Spectrometry of Bio-Macromolecules, Swammerdam Institute for Life Sciences, University of Amsterdam Faculty
of Science, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Linli Zheng
- Department
of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam Faculty
of Science, Science Park 904, 1098 XH Amsterdam, The Netherlands
- Department
of Mass Spectrometry of Bio-Macromolecules, Swammerdam Institute for Life Sciences, University of Amsterdam Faculty
of Science, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Stanley Brul
- Department
of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam Faculty
of Science, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Chris G. de Koster
- Department
of Mass Spectrometry of Bio-Macromolecules, Swammerdam Institute for Life Sciences, University of Amsterdam Faculty
of Science, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Leo J. de Koning
- Department
of Mass Spectrometry of Bio-Macromolecules, Swammerdam Institute for Life Sciences, University of Amsterdam Faculty
of Science, Science Park 904, 1098 XH Amsterdam, The Netherlands
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32
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Nie X, Dong W, Yang C. Genomic reconstruction of σ 54 regulons in Clostridiales. BMC Genomics 2019; 20:565. [PMID: 31288763 PMCID: PMC6615313 DOI: 10.1186/s12864-019-5918-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 06/20/2019] [Indexed: 12/21/2022] Open
Abstract
Background The σ54 factor controls unique promoters and interacts with a specialized activator (enhancer binding proteins [EBP]) for transcription initiation. Although σ54 is present in many Clostridiales species that have great importance in human health and biotechnological applications, the cellular processes controlled by σ54 remain unknown. Results For systematic analysis of the regulatory functions of σ54, we performed comparative genomic reconstruction of transcriptional regulons of σ54 in 57 species from the Clostridiales order. The EBP-binding DNA motifs and regulated genes were identified for 263 EBPs that constitute 39 distinct groups. The reconstructed σ54 regulons contain the genes involved in fermentation and amino acid catabolism. The predicted σ54 binding sites in the genomes of Clostridiales spp. were verified by in vitro binding assays. To our knowledge, this is the first report about direct regulation of the Stickland reactions and butyrate and alcohols synthesis by σ54 and the respective EBPs. Considerable variations were demonstrated in the sizes and gene contents of reconstructed σ54 regulons between different Clostridiales species. It is proposed that σ54 controls butyrate and alcohols synthesis in solvent-producing species, regulates autotrophic metabolism in acetogenic species, and affects the toxin production in pathogenic species. Conclusions This study reveals previously unrecognized functions of σ54 and provides novel insights into the regulation of fermentation and amino acid metabolism in Clostridiales species, which could have potential applications in guiding the treatment and efficient utilization of these species. Electronic supplementary material The online version of this article (10.1186/s12864-019-5918-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiaoqun Nie
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Wenyue Dong
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Chen Yang
- CAS-Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China.
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Type E Botulinum Neurotoxin-Producing Clostridium butyricum Strains Are Aerotolerant during Vegetative Growth. mSystems 2019; 4:mSystems00299-18. [PMID: 31058231 PMCID: PMC6495232 DOI: 10.1128/msystems.00299-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 04/10/2019] [Indexed: 11/21/2022] Open
Abstract
Botulinum neurotoxins, the causative agents of the potentially fatal disease of botulism, are produced by certain Clostridium strains during vegetative growth, usually in anaerobic environments. Our findings indicate that, contrary to current understanding, the growth of neurotoxigenic C. butyricum strains and botulinum neurotoxin type E production can continue upon transfer from anaerobic to aerated conditions and that adaptation of strains to oxygenated environments requires global changes in proteomic and metabolic profiles. We hypothesize that aerotolerance might constitute an unappreciated factor conferring physiological advantages on some botulinum toxin-producing clostridial strains, allowing them to adapt to otherwise restrictive environments. Clostridium butyricum, the type species of the genus Clostridium, is considered an obligate anaerobe, yet it has been shown to grow in the presence of oxygen. C. butyricum strains atypically producing the botulinum neurotoxin type E are the leading cause of type E human botulism in Italy. Here, we show that type E botulinum neurotoxin-producing C. butyricum strains growing exponentially were able to keep growing and producing toxin in vitro upon exposure to air, although less efficiently than under ideal oxygen-depleted conditions. Bacterial growth in air was maintained when the initial cell density was higher than 103 cells/ml. No spores were detected in the cultures aerated for 5 h. To understand the biological mechanisms allowing the adaptation of vegetative cells of C. butyricum type E to oxygen, we compared the proteome and metabolome profiles of the clostridial cultures grown for 5 h under either aerated or anaerobic conditions. The results indicated that bacterial cells responded to oxygen stress by slowing growth and modulating the expression of proteins involved in carbohydrate uptake and metabolism, redox homeostasis, DNA damage response, and bacterial motility. Moreover, the ratio of acetate to butyrate was significantly higher under aeration. This study demonstrates for the first time that a botulinum neurotoxin-producing Clostridium can withstand oxygen during vegetative growth. IMPORTANCE Botulinum neurotoxins, the causative agents of the potentially fatal disease of botulism, are produced by certain Clostridium strains during vegetative growth, usually in anaerobic environments. Our findings indicate that, contrary to current understanding, the growth of neurotoxigenic C. butyricum strains and botulinum neurotoxin type E production can continue upon transfer from anaerobic to aerated conditions and that adaptation of strains to oxygenated environments requires global changes in proteomic and metabolic profiles. We hypothesize that aerotolerance might constitute an unappreciated factor conferring physiological advantages on some botulinum toxin-producing clostridial strains, allowing them to adapt to otherwise restrictive environments.
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Ünal CM, Karagöz MS, Berges M, Priebe C, Borrero de Acuña JM, Wissing J, Jänsch L, Jahn D, Steinert M. Pleiotropic Clostridioides difficile Cyclophilin PpiB Controls Cysteine-Tolerance, Toxin Production, the Central Metabolism and Multiple Stress Responses. Front Pharmacol 2019; 10:340. [PMID: 31024308 PMCID: PMC6459899 DOI: 10.3389/fphar.2019.00340] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/19/2019] [Indexed: 01/05/2023] Open
Abstract
The Gram-positive pathogen Clostridioides difficile is the main bacterial agent of nosocomial antibiotic associated diarrhea. Bacterial peptidyl-prolyl-cis/trans-isomerases (PPIases) are well established modulators of virulence that influence the outcome of human pathologies during infections. Here, we present the first interactomic network of the sole cyclophilin-type PPIase of C. difficile (CdPpiB) and show that it has diverse interaction partners including major enzymes of the amino acid-dependent energy (LdhA, EtfAB, Had, Acd) and the glucose-derived (Fba, GapA, Pfo, Pyk, Pyc) central metabolism. Proteins of the general (UspA), oxidative (Rbr1,2,3, Dsr), alkaline (YloU, YphY) and cold shock (CspB) response were found bound to CdPpiB. The transcriptional (Lrp), translational (InfC, RFF) and folding (GroS, DnaK) control proteins were also found attached. For a crucial enzyme of cysteine metabolism, O-acetylserine sulfhydrylase (CysK), the global transcription regulator Lrp and the flagellar subunit FliC, these interactions were independently confirmed using a bacterial two hybrid system. The active site residues F50, F109, and F110 of CdPpiB were shown to be important for the interaction with the residue P87 of Lrp. CysK activity after heat denaturation was restored by interaction with CdPpiB. In accordance, tolerance toward cell wall stress caused by the exposure to amoxicillin was reduced. In the absence of CdPpiB, C. difficile was more susceptible toward L-cysteine. At the same time, the cysteine-mediated suppression of toxin production ceased resulting in higher cytotoxicity. In summary, the cyclophilin-type PPIase of C. difficile (CdPpiB) coordinates major cellular processes via its interaction with major regulators of transcription, translation, protein folding, stress response and the central metabolism.
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Affiliation(s)
- Can Murat Ünal
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany.,Moleküler Biyoteknoloji Bölümü, Türk-Alman Üniversitesi, Istanbul, Turkey
| | | | - Mareike Berges
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology, Braunschweig, Germany
| | - Christina Priebe
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | | | - Josef Wissing
- Braunschweig Integrated Centre of Systems Biology, Braunschweig, Germany.,Cellular Proteomics Research, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Lothar Jänsch
- Braunschweig Integrated Centre of Systems Biology, Braunschweig, Germany.,Cellular Proteomics Research, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Dieter Jahn
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology, Braunschweig, Germany
| | - Michael Steinert
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology, Braunschweig, Germany.,Helmholtz Centre for Infection Research, Braunschweig, Germany
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Edwards AN, Anjuwon-Foster BR, McBride SM. RstA Is a Major Regulator of Clostridioides difficile Toxin Production and Motility. mBio 2019; 10:e01991-18. [PMID: 30862746 PMCID: PMC6414698 DOI: 10.1128/mbio.01991-18] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 01/25/2019] [Indexed: 01/05/2023] Open
Abstract
Clostridioides difficile infection (CDI) is a toxin-mediated diarrheal disease. Several factors have been identified that influence the production of the two major C. difficile toxins, TcdA and TcdB, but prior published evidence suggested that additional unknown factors were involved in toxin regulation. Previously, we identified a C. difficile regulator, RstA, that promotes sporulation and represses motility and toxin production. We observed that the predicted DNA-binding domain of RstA was required for RstA-dependent repression of toxin genes, motility genes, and rstA transcription. In this study, we further investigated the regulation of toxin and motility gene expression by RstA. DNA pulldown assays confirmed that RstA directly binds the rstA promoter via the predicted DNA-binding domain. Through mutational analysis of the rstA promoter, we identified several nucleotides that are important for RstA-dependent transcriptional regulation. Further, we observed that RstA directly binds and regulates the promoters of the toxin genes tcdA and tcdB, as well as the promoters for the sigD and tcdR genes, which encode regulators of toxin gene expression. Complementation analyses with the Clostridium perfringens RstA ortholog and a multispecies chimeric RstA protein revealed that the C. difficile C-terminal domain is required for RstA DNA-binding activity, suggesting that species-specific signaling controls RstA function. Our data demonstrate that RstA is a transcriptional repressor that autoregulates its own expression and directly inhibits transcription of the two toxin genes and two positive toxin regulators, thereby acting at multiple regulatory points to control toxin production.IMPORTANCEClostridioides difficile is an anaerobic, gastrointestinal pathogen of humans and other mammals. C. difficile produces two major toxins, TcdA and TcdB, which cause the symptoms of the disease, and forms dormant endospores to survive the aerobic environment outside the host. A recently discovered regulatory factor, RstA, inhibits toxin production and positively influences spore formation. Herein, we determine that RstA directly binds its own promoter DNA to repress its own gene transcription. In addition, our data demonstrate that RstA directly represses toxin gene expression and gene expression of two toxin gene activators, TcdR and SigD, creating a complex regulatory network to tightly control toxin production. This study provides a novel regulatory link between C. difficile sporulation and toxin production. Further, our data suggest that C. difficile toxin production is regulated through a direct, species-specific sensing mechanism.
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Affiliation(s)
- Adrianne N Edwards
- Department of Microbiology and Immunology, Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Brandon R Anjuwon-Foster
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
| | - Shonna M McBride
- Department of Microbiology and Immunology, Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
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36
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Neumann-Schaal M, Jahn D, Schmidt-Hohagen K. Metabolism the Difficile Way: The Key to the Success of the Pathogen Clostridioides difficile. Front Microbiol 2019; 10:219. [PMID: 30828322 PMCID: PMC6384274 DOI: 10.3389/fmicb.2019.00219] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 01/28/2019] [Indexed: 12/11/2022] Open
Abstract
Strains of Clostridioides difficile cause detrimental diarrheas with thousands of deaths worldwide. The infection process by the Gram-positive, strictly anaerobic gut bacterium is directly related to its unique metabolism, using multiple Stickland-type amino acid fermentation reactions coupled to Rnf complex-mediated sodium/proton gradient formation for ATP generation. Major pathways utilize phenylalanine, leucine, glycine and proline with the formation of 3-phenylproprionate, isocaproate, butyrate, 5-methylcaproate, valerate and 5-aminovalerate. In parallel a versatile sugar catabolism including pyruvate formate-lyase as a central enzyme and an incomplete tricarboxylic acid cycle to prevent unnecessary NADH formation completes the picture. However, a complex gene regulatory network that carefully mediates the continuous adaptation of this metabolism to changing environmental conditions is only partially elucidated. It involves the pleiotropic regulators CodY and SigH, the known carbon metabolism regulator CcpA, the proline regulator PrdR, the iron regulator Fur, the small regulatory RNA CsrA and potentially the NADH-responsive regulator Rex. Here, we describe the current knowledge of the metabolic principles of energy generation by C. difficile and the underlying gene regulatory scenarios.
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Affiliation(s)
- Meina Neumann-Schaal
- Leibniz Institute DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.,Integrated Centre of Systems Biology (BRICS), Braunschweig University of Technology, Braunschweig, Germany
| | - Dieter Jahn
- Integrated Centre of Systems Biology (BRICS), Braunschweig University of Technology, Braunschweig, Germany.,Institute of Microbiology, Braunschweig University of Technology, Braunschweig, Germany
| | - Kerstin Schmidt-Hohagen
- Integrated Centre of Systems Biology (BRICS), Braunschweig University of Technology, Braunschweig, Germany.,Department of Bioinformatics and Biochemistry, Braunschweig University of Technology, Braunschweig, Germany
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37
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Lensmire JM, Hammer ND. Nutrient sulfur acquisition strategies employed by bacterial pathogens. Curr Opin Microbiol 2019; 47:52-58. [DOI: 10.1016/j.mib.2018.11.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/04/2018] [Accepted: 11/07/2018] [Indexed: 10/27/2022]
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Shayegan Mehr FS, Azimirad M, Mansouri Gilani SN, Ghafurian A, Yadegar A. Effect of sub-MIC values of metronidazole, ciprofloxacin, and imipenem on the growth and toxin production in Clostridioides difficile. GASTROENTEROLOGY AND HEPATOLOGY FROM BED TO BENCH 2019; 12:S163-S168. [PMID: 32099618 PMCID: PMC7011067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AIM This study intends to investigate the effect of sub-minimum inhibitory concentration (sub-MIC) of metronidazole, ciprofloxacin, and imipenem on the growth and toxin production in Clostridioides difficile. BACKGROUND C. difficile is the most common causative agent of hospital-acquired diarrhea. Toxin production in C. difficile appears to be a critical process for induction of the disease. Several factors such as antibiotics can facilitate growth and toxin production in C. difficile. METHODS Five C. difficile strains were grown with and without sub-MIC concentrations of metronidazole, ciprofloxacin, and imipenem (0.5x MIC). The bacterial growth was measured by density at OD620 nm in 0, 4, 8, 12 and 24 h post inoculation. Toxin production was detected using ELISA in culture supernatants as well as in cell pellet. RESULTS The five strains showed minor growth variations in the presence and absence of antibiotic sub-MIC values, except for metronidazole, in which the sub-MIC concentration reduced the growth rate of the resistant isolate in comparison with the control without antibiotic. There were no significant variations in the levels of toxin production with the sub-MIC values of antibiotics examined in comparison with antibiotic-free controls. However, the amount of toxin production in the culture supernatant was greater than in the cell pellet. CONCLUSION The findings of this study suggested that sub-MIC concentrations of antibiotics may have minor effects on bacterial growth and toxin production of C. difficile. Taken together, these findings suggest that presence of antimicrobial agents increased expression levels of certain genes, particularly virulence genes, which may help C. difficile to survive.
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Affiliation(s)
- Farahnaz Sadat Shayegan Mehr
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Masoumeh Azimirad
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Seyedeh Nazanin Mansouri Gilani
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ayub Ghafurian
- Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abbas Yadegar
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Berges M, Michel AM, Lassek C, Nuss AM, Beckstette M, Dersch P, Riedel K, Sievers S, Becher D, Otto A, Maaß S, Rohde M, Eckweiler D, Borrero-de Acuña JM, Jahn M, Neumann-Schaal M, Jahn D. Iron Regulation in Clostridioides difficile. Front Microbiol 2018; 9:3183. [PMID: 30619231 PMCID: PMC6311696 DOI: 10.3389/fmicb.2018.03183] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 12/10/2018] [Indexed: 12/13/2022] Open
Abstract
The response to iron limitation of several bacteria is regulated by the ferric uptake regulator (Fur). The Fur-regulated transcriptional, translational and metabolic networks of the Gram-positive, pathogen Clostridioides difficile were investigated by a combined RNA sequencing, proteomic, metabolomic and electron microscopy approach. At high iron conditions (15 μM) the C. difficile fur mutant displayed a growth deficiency compared to wild type C. difficile cells. Several iron and siderophore transporter genes were induced by Fur during low iron (0.2 μM) conditions. The major adaptation to low iron conditions was observed for the central energy metabolism. Most ferredoxin-dependent amino acid fermentations were significantly down regulated (had, etf, acd, grd, trx, bdc, hbd). The substrates of these pathways phenylalanine, leucine, glycine and some intermediates (phenylpyruvate, 2-oxo-isocaproate, 3-hydroxy-butyryl-CoA, crotonyl-CoA) accumulated, while end products like isocaproate and butyrate were found reduced. Flavodoxin (fldX) formation and riboflavin biosynthesis (rib) were enhanced, most likely to replace the missing ferredoxins. Proline reductase (prd), the corresponding ion pumping RNF complex (rnf) and the reaction product 5-aminovalerate were significantly enhanced. An ATP forming ATPase (atpCDGAHFEB) of the F0F1-type was induced while the formation of a ATP-consuming, proton-pumping V-type ATPase (atpDBAFCEKI) was decreased. The [Fe-S] enzyme-dependent pyruvate formate lyase (pfl), formate dehydrogenase (fdh) and hydrogenase (hyd) branch of glucose utilization and glycogen biosynthesis (glg) were significantly reduced, leading to an accumulation of glucose and pyruvate. The formation of [Fe-S] enzyme carbon monoxide dehydrogenase (coo) was inhibited. The fur mutant showed an increased sensitivity to vancomycin and polymyxin B. An intensive remodeling of the cell wall was observed, Polyamine biosynthesis (spe) was induced leading to an accumulation of spermine, spermidine, and putrescine. The fur mutant lost most of its flagella and motility. Finally, the CRISPR/Cas and a prophage encoding operon were downregulated. Fur binding sites were found upstream of around 20 of the regulated genes. Overall, adaptation to low iron conditions in C. difficile focused on an increase of iron import, a significant replacement of iron requiring metabolic pathways and the restructuring of the cell surface for protection during the complex adaptation phase and was only partly directly regulated by Fur.
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Affiliation(s)
- Mareike Berges
- Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany
| | - Annika-Marisa Michel
- Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany
| | - Christian Lassek
- Center for Functional Genomics of Microbes (CFGM), Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Aaron M Nuss
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Michael Beckstette
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Katharina Riedel
- Center for Functional Genomics of Microbes (CFGM), Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Susanne Sievers
- Center for Functional Genomics of Microbes (CFGM), Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Dörte Becher
- Center for Functional Genomics of Microbes (CFGM), Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Andreas Otto
- Center for Functional Genomics of Microbes (CFGM), Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Sandra Maaß
- Center for Functional Genomics of Microbes (CFGM), Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Denitsa Eckweiler
- Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany
| | | | - Martina Jahn
- Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Meina Neumann-Schaal
- Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Dieter Jahn
- Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
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Poquet I, Saujet L, Canette A, Monot M, Mihajlovic J, Ghigo JM, Soutourina O, Briandet R, Martin-Verstraete I, Dupuy B. Clostridium difficile Biofilm: Remodeling Metabolism and Cell Surface to Build a Sparse and Heterogeneously Aggregated Architecture. Front Microbiol 2018; 9:2084. [PMID: 30258415 PMCID: PMC6143707 DOI: 10.3389/fmicb.2018.02084] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 08/14/2018] [Indexed: 12/11/2022] Open
Abstract
Clostridium difficile is an opportunistic entero-pathogen causing post-antibiotic and nosocomial diarrhea upon microbiota dysbiosis. Although biofilms could contribute to colonization, little is known about their development and physiology. Strain 630Δerm is able to form, in continuous-flow micro-fermentors, macro-colonies and submersed biofilms loosely adhesive to glass. According to gene expression data, in biofilm/planktonic cells, central metabolism is active and fuels fatty acid biosynthesis rather than fermentations. Consistently, succinate is consumed and butyrate production is reduced. Toxin A expression, which is coordinated to metabolism, is down-regulated, while surface proteins, like adhesins and the primary Type IV pili subunits, are over-expressed. C-di-GMP level is probably tightly controlled through the expression of both diguanylate cyclase-encoding genes, like dccA, and phosphodiesterase-encoding genes. The coordinated expression of genes controlled by c-di-GMP and encoding the putative surface adhesin CD2831 and the major Type IV pilin PilA1, suggests that c-di-GMP could be high in biofilm cells. A Bacillus subtilis SinR-like regulator, CD2214, and/or CD2215, another regulator co-encoded in the same operon as CD2214, control many genes differentially expressed in biofilm, and in particular dccA, CD2831 and pilA1 in a positive way. After growth in micro-titer plates and disruption, the biofilm is composed of robust aggregated structures where cells are embedded into a polymorphic material. The intact biofilm observed in situ displays a sparse, heterogeneous and high 3D architecture made of rods and micro-aggregates. The biofilm is denser in a mutant of both CD2214 and CD2215 genes, but it is not affected by the inactivation of neither CD2831 nor pilA1. dccA, when over-expressed, not only increases the biofilm but also triggers its architecture to become homogeneous and highly aggregated, in a way independent of CD2831 and barely dependent of pilA1. Cell micro-aggregation is shown to play a major role in biofilm formation and architecture. This thorough analysis of gene expression reprogramming and architecture remodeling in biofilm lays the foundation for a deeper understanding of this lifestyle and could lead to novel strategies to limit C. difficile spread.
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Affiliation(s)
- Isabelle Poquet
- Micalis Institute, Institut National de la Recherche Agronomique, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France.,Laboratoire Pathogenèse des Bacteries Anaerobies, Institut Pasteur, Paris, France
| | - Laure Saujet
- Laboratoire Pathogenèse des Bacteries Anaerobies, Institut Pasteur, Paris, France.,Sorbonne Paris Cité, Université Paris Diderot, Paris, France
| | - Alexis Canette
- Micalis Institute, Institut National de la Recherche Agronomique, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Marc Monot
- Laboratoire Pathogenèse des Bacteries Anaerobies, Institut Pasteur, Paris, France.,Sorbonne Paris Cité, Université Paris Diderot, Paris, France
| | | | - Jean-Marc Ghigo
- Unité de Génétique des Biofilms, Institut Pasteur, Paris, France
| | - Olga Soutourina
- Laboratoire Pathogenèse des Bacteries Anaerobies, Institut Pasteur, Paris, France.,Sorbonne Paris Cité, Université Paris Diderot, Paris, France
| | - Romain Briandet
- Micalis Institute, Institut National de la Recherche Agronomique, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Isabelle Martin-Verstraete
- Laboratoire Pathogenèse des Bacteries Anaerobies, Institut Pasteur, Paris, France.,Sorbonne Paris Cité, Université Paris Diderot, Paris, France
| | - Bruno Dupuy
- Laboratoire Pathogenèse des Bacteries Anaerobies, Institut Pasteur, Paris, France.,Sorbonne Paris Cité, Université Paris Diderot, Paris, France
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Passmore IJ, Letertre MPM, Preston MD, Bianconi I, Harrison MA, Nasher F, Kaur H, Hong HA, Baines SD, Cutting SM, Swann JR, Wren BW, Dawson LF. Para-cresol production by Clostridium difficile affects microbial diversity and membrane integrity of Gram-negative bacteria. PLoS Pathog 2018; 14:e1007191. [PMID: 30208103 PMCID: PMC6135563 DOI: 10.1371/journal.ppat.1007191] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 06/29/2018] [Indexed: 11/18/2022] Open
Abstract
Clostridium difficile is a Gram-positive spore-forming anaerobe and a major cause of antibiotic-associated diarrhoea. Disruption of the commensal microbiota, such as through treatment with broad-spectrum antibiotics, is a critical precursor for colonisation by C. difficile and subsequent disease. Furthermore, failure of the gut microbiota to recover colonisation resistance can result in recurrence of infection. An unusual characteristic of C. difficile among gut bacteria is its ability to produce the bacteriostatic compound para-cresol (p-cresol) through fermentation of tyrosine. Here, we demonstrate that the ability of C. difficile to produce p-cresol in vitro provides a competitive advantage over gut bacteria including Escherichia coli, Klebsiella oxytoca and Bacteroides thetaiotaomicron. Metabolic profiling of competitive co-cultures revealed that acetate, alanine, butyrate, isobutyrate, p-cresol and p-hydroxyphenylacetate were the main metabolites responsible for differentiating the parent strain C. difficile (630Δerm) from a defined mutant deficient in p-cresol production. Moreover, we show that the p-cresol mutant displays a fitness defect in a mouse relapse model of C. difficile infection (CDI). Analysis of the microbiome from this mouse model of CDI demonstrates that colonisation by the p-cresol mutant results in a distinctly altered intestinal microbiota, and metabolic profile, with a greater representation of Gammaproteobacteria, including the Pseudomonales and Enterobacteriales. We demonstrate that Gammaproteobacteria are susceptible to exogenous p-cresol in vitro and that there is a clear divide between bacterial Phyla and their susceptibility to p-cresol. In general, Gram-negative species were relatively sensitive to p-cresol, whereas Gram-positive species were more tolerant. This study demonstrates that production of p-cresol by C. difficile has an effect on the viability of intestinal bacteria as well as the major metabolites produced in vitro. These observations are upheld in a mouse model of CDI, in which p-cresol production affects the biodiversity of gut microbiota and faecal metabolite profiles, suggesting that p-cresol production contributes to C. difficile survival and pathogenesis.
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Affiliation(s)
- Ian J. Passmore
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Mark D. Preston
- Bioinformatics and Next Generation sequencing core facility, National Institute for Biological Standards and Control South Mimms, Potters Bar, United Kingdom
| | - Irene Bianconi
- Department of Biomedical Sciences, Royal Holloway University of London, Egham, United Kingdom
| | - Mark A. Harrison
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Fauzy Nasher
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Harparkash Kaur
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Huynh A. Hong
- Department of Biomedical Sciences, Royal Holloway University of London, Egham, United Kingdom
| | - Simon D. Baines
- Department of Biological and Environmental Sciences, University of Hertfordshire, Hatfield, United Kingdom
| | - Simon M. Cutting
- Department of Biomedical Sciences, Royal Holloway University of London, Egham, United Kingdom
| | - Jonathan R. Swann
- Department of Surgery & Cancer, Imperial College London, London, United Kingdom
| | - Brendan W. Wren
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Lisa F. Dawson
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
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42
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Hofmann JD, Otto A, Berges M, Biedendieck R, Michel AM, Becher D, Jahn D, Neumann-Schaal M. Metabolic Reprogramming of Clostridioides difficile During the Stationary Phase With the Induction of Toxin Production. Front Microbiol 2018; 9:1970. [PMID: 30186274 PMCID: PMC6110889 DOI: 10.3389/fmicb.2018.01970] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/03/2018] [Indexed: 12/20/2022] Open
Abstract
The obligate anaerobe, spore forming bacterium Clostridioides difficile (formerly Clostridium difficile) causes nosocomial and community acquired diarrhea often associated with antibiotic therapy. Major virulence factors of the bacterium are the two large clostridial toxins TcdA and TcdB. The production of both toxins was found strongly connected to the metabolism and the nutritional status of the growth environment. Here, we systematically investigated the changes of the gene regulatory, proteomic and metabolic networks of C. difficile 630Δerm underlying the adaptation to the non-growing state in the stationary phase. Integrated data from time-resolved transcriptome, proteome and metabolome investigations performed under defined growth conditions uncovered multiple adaptation strategies. Overall changes in the cellular processes included the downregulation of ribosome production, lipid metabolism, cold shock proteins, spermine biosynthesis, and glycolysis and in the later stages of riboflavin and coenzyme A (CoA) biosynthesis. In contrast, different chaperones, several fermentation pathways, and cysteine, serine, and pantothenate biosynthesis were found upregulated. Focusing on the Stickland amino acid fermentation and the central carbon metabolism, we discovered the ability of C. difficile to replenish its favored amino acid cysteine by a pathway starting from the glycolytic 3-phosphoglycerate via L-serine as intermediate. Following the growth course, the reductive equivalent pathways used were sequentially shifted from proline via leucine/phenylalanine to the central carbon metabolism first to butanoate fermentation and then further to lactate fermentation. The toxin production was found correlated mainly to fluxes of the central carbon metabolism. Toxin formation in the supernatant was detected when the flux changed from butanoate to lactate synthesis in the late stationary phase. The holistic view derived from the combination of transcriptome, proteome and metabolome data allowed us to uncover the major metabolic strategies that are used by the clostridial cells to maintain its cellular homeostasis and ensure survival under starvation conditions.
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Affiliation(s)
- Julia D Hofmann
- Department of Bioinformatics and Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany
| | - Andreas Otto
- Department for Microbial Proteomics, University of Greifswald, Greifswald, Germany
| | - Mareike Berges
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Rebekka Biedendieck
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Annika-Marisa Michel
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Dörte Becher
- Department for Microbial Proteomics, University of Greifswald, Greifswald, Germany
| | - Dieter Jahn
- Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Meina Neumann-Schaal
- Department of Bioinformatics and Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Germany.,Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
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43
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Woods EC, Edwards AN, Childress KO, Jones JB, McBride SM. The C. difficile clnRAB operon initiates adaptations to the host environment in response to LL-37. PLoS Pathog 2018; 14:e1007153. [PMID: 30125334 PMCID: PMC6117091 DOI: 10.1371/journal.ppat.1007153] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/30/2018] [Accepted: 07/16/2018] [Indexed: 01/05/2023] Open
Abstract
To cause disease, Clostridioides (Clostridium) difficile must resist killing by innate immune effectors in the intestine, including the host antimicrobial peptide, cathelicidin (LL-37). The mechanisms that enable C. difficile to adapt to the intestine in the presence of antimicrobial peptides are unknown. Expression analyses revealed an operon, CD630_16170-CD630_16190 (clnRAB), which is highly induced by LL-37 and is not expressed in response to other cell-surface active antimicrobials. This operon encodes a predicted transcriptional regulator (ClnR) and an ABC transporter system (ClnAB), all of which are required for function. Analyses of a clnR mutant indicate that ClnR is a pleiotropic regulator that directly binds to LL-37 and controls expression of numerous genes, including many involved in metabolism, cellular transport, signaling, gene regulation, and pathogenesis. The data suggest that ClnRAB is a novel regulatory mechanism that senses LL-37 as a host signal and regulates gene expression to adapt to the host intestinal environment during infection.
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Affiliation(s)
- Emily C. Woods
- Department of Microbiology and Immunology, and Emory University Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Adrianne N. Edwards
- Department of Microbiology and Immunology, and Emory University Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Kevin O. Childress
- Department of Microbiology and Immunology, and Emory University Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Joshua B. Jones
- Department of Microbiology and Immunology, and Emory University Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Shonna M. McBride
- Department of Microbiology and Immunology, and Emory University Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, United States of America
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44
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Gu H, Shi K, Liao Z, Qi H, Chen S, Wang H, Li S, Ma Y, Wang J. Time-resolved transcriptome analysis of Clostridium difficile R20291 response to cysteine. Microbiol Res 2018; 215:114-125. [PMID: 30172297 DOI: 10.1016/j.micres.2018.07.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/21/2018] [Accepted: 07/07/2018] [Indexed: 01/05/2023]
Abstract
The incidence of Clostridium difficile infection has been steadily rising over the past decade. The increase in the rate of incidence is associated with the specific NAP1/BI/027 strains which are "hypervirulent" and have led to several large outbreaks since their emergence. However, the relation between these outbreaks and virulence regulation mechanisms remains unclear. It has been reported that the major virulence factor TcdA and TcdB in C. difficile could be repressed by cysteine. Here, we investigated the functional and virulence-associated regulation of C. difficile R20291 response to cysteine by using a time-resolved genome-wide transcriptome analysis. Dramatic changes of gene expression in C. difficile revealed functional processes related to transport, metabolism, and regulators in the presence of cysteine during different phases of growth. Flagellar and ribosomal genes were significantly down-regulated in long-term response to cysteine. Many NAP1/BI/027- specific genes were also modulated by cysteine. In addition, cdsB inactivation in C. difficile R20291 could remove the repression of toxin synthesis but could not remove the repression of butyrate production in the presence of cysteine. This suggests that toxin synthesis and butyrate production might have different regulatory controls in response to cysteine. Altogether, our research provides important insights into the regulatory mechanisms of C. difficile response to cysteine.
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Affiliation(s)
- Huawei Gu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Kan Shi
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Zhengping Liao
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Haonan Qi
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Shuyi Chen
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Haiying Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Shan Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Yi Ma
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Jufang Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China.
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45
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Thanissery R, Zeng D, Doyle RG, Theriot CM. A Small Molecule-Screening Pipeline to Evaluate the Therapeutic Potential of 2-Aminoimidazole Molecules Against Clostridium difficile. Front Microbiol 2018; 9:1206. [PMID: 29928268 PMCID: PMC5997789 DOI: 10.3389/fmicb.2018.01206] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/17/2018] [Indexed: 12/19/2022] Open
Abstract
Antibiotics are considered to be the first line of treatment for mild to moderately severe Clostridium difficile infection (CDI) in humans. However, antibiotics are also risk factors for CDI as they decrease colonization resistance against C. difficile by altering the gut microbiota and metabolome. Finding compounds that selectively inhibit different stages of the C. difficile life cycle, while sparing the indigenous gut microbiota is important for the development of alternatives to standard antibiotic treatment. 2-aminoimidazole (2-AI) molecules are known to disrupt bacterial protection mechanisms in antibiotic resistant bacteria such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus, but are yet to be evaluated against C. difficile. A comprehensive small molecule-screening pipeline was developed to investigate how novel small molecules affect different stages of the C. difficile life cycle (growth, toxin, and sporulation) in vitro, and a library of commensal bacteria that are associated with colonization resistance against C. difficile. The initial screening tested the efficacy of eleven 2-AI molecules (compound 1 through 11) against C. difficile R20291 compared to a vancomycin (2 μg/ml) control. Molecules were selected for their ability to inhibit C. difficile growth, toxin activity, and sporulation. Further testing included growth inhibition of other C. difficile strains (CD196, M68, CF5, 630, BI9, M120) belonging to distinct PCR ribotypes, and a commensal panel (Bacteroides fragilis, B. thetaiotaomicron, C. scindens, C. hylemonae, Lactobacillus acidophilus, L. gasseri, Escherichia coli, B. longum subsp. infantis). Three molecules compound 1 and 2, and 3 were microbicidal, whereas compounds 4, 7, 9, and 11 inhibited toxin activity without affecting the growth of C. difficile strains and the commensal microbiota. The antimicrobial and anti-toxin effects of 2-AI molecules need to be further characterized for mode of action and validated in a mouse model of CDI.
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Affiliation(s)
- Rajani Thanissery
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Daina Zeng
- Agile Sciences, Inc., Raleigh, NC, United States
| | - Raul G Doyle
- Agile Sciences, Inc., Raleigh, NC, United States
| | - Casey M Theriot
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
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46
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Neumann-Schaal M, Metzendorf NG, Troitzsch D, Nuss AM, Hofmann JD, Beckstette M, Dersch P, Otto A, Sievers S. Tracking gene expression and oxidative damage of O 2-stressed Clostridioides difficile by a multi-omics approach. Anaerobe 2018; 53:94-107. [PMID: 29859941 DOI: 10.1016/j.anaerobe.2018.05.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 05/28/2018] [Accepted: 05/30/2018] [Indexed: 02/06/2023]
Abstract
Clostridioides difficile is the major pathogen causing diarrhea following antibiotic treatment. It is considered to be a strictly anaerobic bacterium, however, previous studies have shown a certain and strain-dependent oxygen tolerance. In this study, the model strain C. difficile 630Δerm was shifted to micro-aerobiosis and was found to stay growing to the same extent as anaerobically growing cells with only few changes in the metabolite pattern. However, an extensive change in gene expression was determined by RNA-Seq. The most striking adaptation strategies involve a change in the reductive fermentation pathways of the amino acids proline, glycine and leucine. But also a far-reaching restructuring in the carbohydrate metabolism was detected with changes in the phosphotransferase system (PTS) facilitated uptake of sugars and a repression of enzymes of glycolysis and butyrate fermentation. Furthermore, a temporary induction in the synthesis of cofactor riboflavin was detected possibly due to an increased demand for flavin mononucleotid (FMN) and flavin adenine dinucleotide (FAD) in redox reactions. However, biosynthesis of the cofactors thiamin pyrophosphate and cobalamin were repressed deducing oxidation-prone enzymes and intermediates in these pathways. Micro-aerobically shocked cells were characterized by an increased demand for cysteine and a thiol redox proteomics approach revealed a dramatic increase in the oxidative state of cysteine in more than 800 peptides after 15 min of micro-aerobic shock. This provides not only a catalogue of oxidation-prone cysteine residues in the C. difficile proteome but also puts the amino acid cysteine into a key position in the oxidative stress response. Our study suggests that tolerance of C. difficile towards O2 is based on a complex and far-reaching adjustment of global gene expression which leads to only a slight change in phenotype.
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Affiliation(s)
- Meina Neumann-Schaal
- Department of Bioinformatics and Biochemistry and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany
| | - Nicole G Metzendorf
- Department of Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, 17489, Greifswald, Germany
| | - Daniel Troitzsch
- Department of Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, 17489, Greifswald, Germany
| | - Aaron Mischa Nuss
- Department of Molecular Infection Biology, Helmholtz Center for Infection Research, Braunschweig, Germany
| | - Julia Danielle Hofmann
- Department of Bioinformatics and Biochemistry and Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany
| | - Michael Beckstette
- Department of Molecular Infection Biology, Helmholtz Center for Infection Research, Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Center for Infection Research, Braunschweig, Germany
| | - Andreas Otto
- Department of Microbial Proteomics, Institute of Microbiology, University of Greifswald, 17489, Greifswald, Germany
| | - Susanne Sievers
- Department of Microbial Physiology and Molecular Biology, Institute of Microbiology, University of Greifswald, 17489, Greifswald, Germany.
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47
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Nawrocki KL, Wetzel D, Jones JB, Woods EC, McBride SM. Ethanolamine is a valuable nutrient source that impacts Clostridium difficile pathogenesis. Environ Microbiol 2018; 20:1419-1435. [PMID: 29349925 PMCID: PMC5903940 DOI: 10.1111/1462-2920.14048] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 01/03/2018] [Accepted: 01/14/2018] [Indexed: 12/12/2022]
Abstract
Clostridium (Clostridioides) difficile is a gastrointestinal pathogen that colonizes the intestinal tract of mammals and can cause severe diarrheal disease. Although C. difficile growth is confined to the intestinal tract, our understanding of the specific metabolites and host factors that are important for the growth of the bacterium is limited. In other enteric pathogens, the membrane-derived metabolite, ethanolamine (EA), is utilized as a nutrient source and can function as a signal to initiate the production of virulence factors. In this study, we investigated the effects of ethanolamine and the role of the predicted ethanolamine gene cluster (CD1907-CD1925) on C. difficile growth. Using targeted mutagenesis, we disrupted genes within the eut cluster and assessed their roles in ethanolamine utilization, and the impact of eut disruption on the outcome of infection in a hamster model of disease. Our results indicate that the eut gene cluster is required for the growth of C. difficile on ethanolamine as a primary nutrient source. Further, the inability to utilize ethanolamine resulted in greater virulence and a shorter time to morbidity in the animal model. Overall, these data suggest that ethanolamine is an important nutrient source within the host and that, in contrast to other intestinal pathogens, the metabolism of ethanolamine by C. difficile can delay the onset of disease.
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Affiliation(s)
- Kathryn L. Nawrocki
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Daniela Wetzel
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Joshua B. Jones
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Emily C. Woods
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Shonna M. McBride
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
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48
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Sievers S, Dittmann S, Jordt T, Otto A, Hochgräfe F, Riedel K. Comprehensive Redox Profiling of the Thiol Proteome of Clostridium difficile. Mol Cell Proteomics 2018; 17:1035-1046. [PMID: 29496906 DOI: 10.1074/mcp.tir118.000671] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Indexed: 11/06/2022] Open
Abstract
The strictly anaerobic bacterium C. difficile has become one of the most problematic hospital acquired pathogens and a major burden for health care systems. Although antibiotics work effectively in most C. difficile infections (CDIs), their detrimental effect on the intestinal microbiome paves the way for recurrent episodes of CDI. To develop alternative, non-antibiotics-based treatment strategies, deeper knowledge on the physiology of C. difficile, stress adaptation mechanisms and regulation of virulence factors is mandatory. The focus of this work was to tackle the thiol proteome of C. difficile and its stress-induced alterations, because recent research has reported that the amino acid cysteine plays a central role in the metabolism of this pathogen. We have developed a novel cysteine labeling approach to determine the redox state of protein thiols on a global scale. Applicability of this technique was demonstrated by inducing disulfide stress using the chemical diamide. The method can be transferred to any kind of redox challenge and was applied in this work to assess the effect of bile acids on the thiol proteome of C. difficile We present redox-quantification for more than 1,500 thiol peptides and discuss the general difficulty of redox analyses of peptides possessing more than a single cysteine residue. The presented method will be especially useful not only when determining redox status, but also for providing information on protein quantity. Additionally, our comprehensive data set reveals protein cysteine sites particularly susceptible to oxidation and builds a groundwork for redox proteomics studies in C. difficile.
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Affiliation(s)
- Susanne Sievers
- From the ‡Department of Microbial Physiology & Molecular Biology;
| | - Silvia Dittmann
- From the ‡Department of Microbial Physiology & Molecular Biology
| | - Tim Jordt
- From the ‡Department of Microbial Physiology & Molecular Biology
| | | | - Falko Hochgräfe
- ¶Junior Research Group Pathoproteomics, Institute of Microbiology, University of Greifswald, 17489 Greifswald, Germany
| | - Katharina Riedel
- From the ‡Department of Microbial Physiology & Molecular Biology
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49
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Szabo C. A timeline of hydrogen sulfide (H 2S) research: From environmental toxin to biological mediator. Biochem Pharmacol 2018; 149:5-19. [PMID: 28947277 PMCID: PMC5862769 DOI: 10.1016/j.bcp.2017.09.010] [Citation(s) in RCA: 155] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 09/20/2017] [Indexed: 02/07/2023]
Abstract
The history of H2S - as an environmental toxin - dates back to 1700, to the observations of the Italian physician Bernardino Ramazzini, whose book "De Morbis Artificum Diatriba" described the painful eye irritation and inflammation of "sewer gas" in sewer workers. The gas has subsequently been identified as hydrogen sulfide (H2S), and opened three centuries of research into the biological roles of H2S. The current article highlights the key discoveries in the field of H2S research, including (a) the toxicological studies, which characterized H2S as an environmental toxin, and identified some of its modes of action, including the inhibition of mitochondrial respiration; (b) work in the field of bacteriology, which, starting in the early 1900s, identified H2S as a bacterial product - with subsequently defined roles in the regulation of periodontal disease (oral bacterial flora), intestinal epithelial cell function (enteral bacterial flora) as well as in the regulation of bacterial resistance to antibiotics; and (c), work in diverse fields of mammalian biology, which, starting in the 1940s, identified H2S as an endogenous mammalian enzymatic product, the functions of which - among others, in the cardiovascular and nervous system - have become subjects of intensive investigation for the last decade. The current review not only enumerates the key discoveries related to H2S made over the last three centuries, but also compiles the most frequently cited papers in the field which have been published over the last decade and highlights some of the current 'hot topics' in the field of H2S biology.
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Affiliation(s)
- Csaba Szabo
- Department of Anesthesiology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA.
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50
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Gu H, Yang Y, Wang M, Chen S, Wang H, Li S, Ma Y, Wang J. Novel Cysteine Desulfidase CdsB Involved in Releasing Cysteine Repression of Toxin Synthesis in Clostridium difficile. Front Cell Infect Microbiol 2018; 7:531. [PMID: 29376034 PMCID: PMC5767170 DOI: 10.3389/fcimb.2017.00531] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Accepted: 12/18/2017] [Indexed: 01/05/2023] Open
Abstract
Clostridium difficile, a major cause of nosocomial diarrhea and pseudomembranous colitis, still poses serious health-care challenges. The expression of its two main virulence factors, TcdA and TcdB, is reportedly repressed by cysteine, but molecular mechanism remains unclear. The cysteine desulfidase CdsB affects the virulence and infection progresses of some bacteria. The C. difficile strain 630 genome encodes a homolog of CdsB, and in the present study, we analyzed its role in C. difficile 630Δerm by constructing an isogenic ClosTron-based cdsB mutant. When C. difficile was cultured in TY broth supplemented with cysteine, the cdsB gene was rapidly induced during the exponential growth phase. The inactivation of cdsB not only affected the resistance of C. difficile to cysteine, but also altered the expression levels of intracellular cysteine-degrading enzymes and the production of hydrogen sulfide. This suggests that C. difficile CdsB is a major inducible cysteine-degrading enzyme. The inactivation of the cdsB gene in C. difficile also removed the cysteine-dependent repression of toxin production, but failed to remove the Na2S-dependent repression, which supports that the cysteine-dependent repression of toxin production is probably attributable to the accumulation of cysteine by-products. We also mapped a δ54 (SigL)-dependent promoter upstream from the cdsB gene, and cdsB expression was not induced in response to cysteine in the cdsR::ermB or sigL::ermB strain. Using a reporter gene fusion analysis, we identified the necessary promoter sequence for cysteine-dependent cdsB expression. Taken together, these results indicate that CdsB is a key inducible cysteine desulfidase in C. difficile which is regulated by δ54 and CdsR in response to cysteine and that cysteine-dependent regulation of toxin production is closely associated with cysteine degradation.
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Affiliation(s)
- Huawei Gu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Yingyin Yang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Meng Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Shuyi Chen
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Haiying Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Shan Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Yi Ma
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Jufang Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
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