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Nerber HN, Baloh M, Brehm JN, Sorg JA. The small acid-soluble proteins of Clostridioides difficile regulate sporulation in a SpoIVB2-dependent manner. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.17.541253. [PMID: 37292792 PMCID: PMC10245694 DOI: 10.1101/2023.05.17.541253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Clostridioides difficile is a pathogen whose transmission relies on the formation of dormant endospores. Spores are highly resilient forms of bacteria that resist environmental and chemical insults. In recent work, we found that C. difficile SspA and SspB, two small acid-soluble proteins (SASPs), protect spores from UV damage and, interestingly, are necessary for the formation of mature spores. Here, we build upon this finding and show that C. difficile sspA and sspB are required for the formation of the spore cortex layer. Moreover, using an EMS mutagenesis selection strategy, we identified mutations that suppressed the defect in sporulation of C. difficile SASP mutants. Many of these strains contained mutations in CDR20291_0714 ( spoIVB2 ) revealing a connection between the SpoIVB2 protease and the SASPs in the sporulation pathway. This work builds upon the hypothesis that the small acid-soluble proteins can regulate gene expression. Importance C. difficile is easily spread through the production of highly resistant spores. Understanding how spores are formed could yield valuable insight into how the sporulation process can be halted to render spores that are sensitive to cleaning methods. Here, we identify another protein involved in the sporulation process that is seemingly controlled by the small acid-soluble proteins (SASPs). This discovery allows us to better understand how the C. difficile SASPs may bind to specific sites on the genome to regulate gene expression.
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Ingelman H, Heffernan JK, Harris A, Brown SD, Shaikh KM, Saqib AY, Pinheiro MJ, de Lima LA, Martinez KR, Gonzalez-Garcia RA, Hawkins G, Daleiden J, Tran L, Zeleznik H, Jensen RO, Reynoso V, Schindel H, Jänes J, Simpson SD, Köpke M, Marcellin E, Valgepea K. Autotrophic adaptive laboratory evolution of the acetogen Clostridium autoethanogenum delivers the gas-fermenting strain LAbrini with superior growth, products, and robustness. N Biotechnol 2024; 83:S1871-6784(24)00023-2. [PMID: 38871051 DOI: 10.1016/j.nbt.2024.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 06/05/2024] [Accepted: 06/10/2024] [Indexed: 06/15/2024]
Abstract
Microbes able to convert gaseous one-carbon (C1) waste feedstocks are increasingly important to transition to the sustainable production of renewable chemicals and fuels. Acetogens are interesting biocatalysts since gas fermentation using Clostridium autoethanogenum has been commercialised. However, most acetogen strains need complex nutrients, display slow growth, and are not robust for bioreactor fermentations. In this work, we used three different and independent adaptive laboratory evolution (ALE) strategies to evolve the wild-type C. autoethanogenum to grow faster, without yeast extract and to be robust in operating continuous bioreactor cultures. Multiple evolved strains with improved phenotypes were isolated on minimal media with one strain, named "LAbrini", exhibiting superior performance regarding the maximum specific growth rate, product profile, and robustness in continuous cultures. Whole-genome sequencing of the evolved strains identified 25 mutations. Of particular interest are two genes that acquired seven different mutations across the three ALE strategies, potentially as a result of convergent evolution. Reverse genetic engineering of mutations in potentially sporulation-related genes CLAU_3129 (spo0A) and CLAU_1957 recovered all three superior features of our ALE strains through triggering significant proteomic rearrangements. This work provides a robust C. autoethanogenum strain "LAbrini" to accelerate phenotyping and genetic engineering and to better understand acetogen metabolism.
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Affiliation(s)
- Henri Ingelman
- ERA Chair in Gas Fermentation Technologies, Institute of Bioengineering, University of Tartu, 50411 Tartu, Estonia
| | - James K Heffernan
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, 4072 St. Lucia, Australia
| | | | | | | | - Asfand Yar Saqib
- ERA Chair in Gas Fermentation Technologies, Institute of Bioengineering, University of Tartu, 50411 Tartu, Estonia
| | - Marina J Pinheiro
- ERA Chair in Gas Fermentation Technologies, Institute of Bioengineering, University of Tartu, 50411 Tartu, Estonia
| | - Lorena Azevedo de Lima
- ERA Chair in Gas Fermentation Technologies, Institute of Bioengineering, University of Tartu, 50411 Tartu, Estonia
| | - Karen Rodriguez Martinez
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, 4072 St. Lucia, Australia
| | - Ricardo A Gonzalez-Garcia
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, 4072 St. Lucia, Australia
| | | | | | | | | | | | | | | | - Jürgen Jänes
- Institute of Molecular Systems Biology, ETH Zürich, 8049 Zürich, Switzerland
| | | | | | - Esteban Marcellin
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, 4072 St. Lucia, Australia.
| | - Kaspar Valgepea
- ERA Chair in Gas Fermentation Technologies, Institute of Bioengineering, University of Tartu, 50411 Tartu, Estonia.
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Wang C, Defoirdt T, Rajkovic A. The impact of indole and mucin on sporulation, biofilm formation, and enterotoxin production in foodborne Clostridium perfringens. J Appl Microbiol 2024; 135:lxae083. [PMID: 38544331 DOI: 10.1093/jambio/lxae083] [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: 01/25/2024] [Revised: 03/13/2024] [Accepted: 03/26/2024] [Indexed: 04/12/2024]
Abstract
AIMS Indole and mucin are compounds found in the host environment as they are produced by the host or by the host-associated microbiota. This study investigated whether indole and mucin impact Clostridium perfringens growth and sporulation, as well as enterotoxin production and biofilm formation. METHODS AND RESULTS There was no impact on growth of Cl. perfringens for up to 400 µM indole and 240 mg/l mucin, and neither indole nor mucin affected sporulation. Reverse-transcriptase qPCR showed that mucin strongly upregulated the expression of Cl. perfringens enterotoxin (up to 121-fold increase), whereas indole had a much more modest effect (2-fold). This was also reflected in increased Cl. perfringens enterotoxin levels in mucin-treated Cl. perfringens (as assessed by a reversed passive latex agglutination assay). Finally, mucin and indole significantly increased biofilm formation of Cl. perfringens, although the effect size was relatively small (less than 1.5 fold). CONCLUSION These results indicate that Cl. perfringens can sense its presence in a host environment by responding to mucin, and thereby markedly increased enterotoxin production.
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Affiliation(s)
- Chao Wang
- Research Unit Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Tom Defoirdt
- Center for Microbial Ecology and Technology, Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Andreja Rajkovic
- Research Unit Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
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Yang Y, Chen R, Rahman MU, Wei C, Fan B. The sprT Gene of Bacillus velezensis FZB42 Is Involved in Biofilm Formation and Bacilysin Production. Int J Mol Sci 2023; 24:16815. [PMID: 38069139 PMCID: PMC10706128 DOI: 10.3390/ijms242316815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 11/22/2023] [Accepted: 11/24/2023] [Indexed: 12/18/2023] Open
Abstract
Bacillus velezensis FZB42, a representative strain of plant-growth-promoting rhizobacteria (PGPR), can form robust biofilm and produce multiple antibiotics against a wild range of phytopathogens. In this study, we observed different biofilm morphology of the mutant Y4, derived from a TnYLB-1 transposon insertion library of B. velezensis FZB42. We identified that the transposon was inserted into the sprT gene in Y4. Our bioinformatics analysis revealed that the SprT protein is an unstable hydrophilic protein located in the cytoplasm. It is highly conserved in Bacillus species and predicted to function as a metalloprotease by binding zinc ions. We also demonstrated that ΔsprT significantly reduced the swarming ability of FZB42 by ~5-fold and sporulation capacity by ~25-fold. In addition, the antagonistic experiments showed that, compared to the wild type, the ΔsprT strain exhibited significantly reduced inhibition against Staphylococcus aureus ATCC-9144 and Phytophthora sojae, indicating that the inactivation of sprT led to decreased production of the antibiotic bacilysin. The HPLC-MS analysis confirmed that bacilysin was indeed decreased in the ΔsprT strain, and qPCR analysis revealed that ΔsprT down-regulated the expression of the genes for bacilysin biosynthesis. Our results suggest that the sprT gene plays a regulatory role in multiple characteristics of B. velezensis FZB42, including biofilm formation, swarming, sporulation, and antibiotic production.
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Affiliation(s)
- Yihan Yang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China;
- College of Life Science, Nanjing Forestry University, Nanjing 210037, China; (R.C.); (M.U.R.); (C.W.)
| | - Ruofu Chen
- College of Life Science, Nanjing Forestry University, Nanjing 210037, China; (R.C.); (M.U.R.); (C.W.)
| | - Mati Ur Rahman
- College of Life Science, Nanjing Forestry University, Nanjing 210037, China; (R.C.); (M.U.R.); (C.W.)
| | - Chunyue Wei
- College of Life Science, Nanjing Forestry University, Nanjing 210037, China; (R.C.); (M.U.R.); (C.W.)
| | - Ben Fan
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China;
- College of Life Science, Nanjing Forestry University, Nanjing 210037, China; (R.C.); (M.U.R.); (C.W.)
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Ma Y, Sannino D, Linden JR, Haigh S, Zhao B, Grigg JB, Zumbo P, Dündar F, Butler D, Profaci CP, Telesford K, Winokur PN, Rumah KR, Gauthier SA, Fischetti VA, McClane BA, Uzal FA, Zexter L, Mazzucco M, Rudick R, Danko D, Balmuth E, Nealon N, Perumal J, Kaunzner U, Brito IL, Chen Z, Xiang JZ, Betel D, Daneman R, Sonnenberg GF, Mason CE, Vartanian T. Epsilon toxin-producing Clostridium perfringens colonize the multiple sclerosis gut microbiome overcoming CNS immune privilege. J Clin Invest 2023; 133:e163239. [PMID: 36853799 PMCID: PMC10145940 DOI: 10.1172/jci163239] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 02/23/2023] [Indexed: 03/01/2023] Open
Abstract
Multiple sclerosis (MS) is a complex disease of the CNS thought to require an environmental trigger. Gut dysbiosis is common in MS, but specific causative species are unknown. To address this knowledge gap, we used sensitive and quantitative PCR detection to show that people with MS were more likely to harbor and show a greater abundance of epsilon toxin-producing (ETX-producing) strains of C. perfringens within their gut microbiomes compared with individuals who are healthy controls (HCs). Isolates derived from patients with MS produced functional ETX and had a genetic architecture typical of highly conjugative plasmids. In the active immunization model of experimental autoimmune encephalomyelitis (EAE), where pertussis toxin (PTX) is used to overcome CNS immune privilege, ETX can substitute for PTX. In contrast to PTX-induced EAE, where inflammatory demyelination is largely restricted to the spinal cord, ETX-induced EAE caused demyelination in the corpus callosum, thalamus, cerebellum, brainstem, and spinal cord, more akin to the neuroanatomical lesion distribution seen in MS. CNS endothelial cell transcriptional profiles revealed ETX-induced genes that are known to play a role in overcoming CNS immune privilege. Together, these findings suggest that ETX-producing C. perfringens strains are biologically plausible pathogens in MS that trigger inflammatory demyelination in the context of circulating myelin autoreactive lymphocytes.
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Affiliation(s)
- Yinghua Ma
- Feil Family Brain and Mind Research Institute
| | | | | | | | - Baohua Zhao
- Feil Family Brain and Mind Research Institute
| | - John B. Grigg
- Jill Roberts Institute for Research in Inflammatory Bowel Disease
- Joan and Sanford I. Weill Department of Medicine, and
- Department of Microbiology and Immunology, Weill Cornell Medical College, Cornell University, New York, New York, USA
- Immunology and Microbial Pathogenesis Program and
| | - Paul Zumbo
- Applied Bioinformatics Core, Division of Hematology/Oncology, Department of Medicine, Institute for Computational Biomedicine, Weill Cornell Medicine, New York, New York, USA
- Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Friederike Dündar
- Applied Bioinformatics Core, Division of Hematology/Oncology, Department of Medicine, Institute for Computational Biomedicine, Weill Cornell Medicine, New York, New York, USA
- Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Daniel Butler
- Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Caterina P. Profaci
- Departments of Pharmacology and Neurosciences, UCSD, San Diego, California, USA
| | | | - Paige N. Winokur
- Harold and Margaret Milliken Hatch Laboratory of Neuro-endocrinology and
| | - Kareem R. Rumah
- Laboratory of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, New York, USA
| | - Susan A. Gauthier
- Department of Neurology, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Vincent A. Fischetti
- Laboratory of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, New York, USA
| | - Bruce A. McClane
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Francisco A. Uzal
- California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, UCD, Davis, California, USA
| | - Lily Zexter
- Department of Neurology, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | | | | | - David Danko
- Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | | | - Nancy Nealon
- Department of Neurology, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Jai Perumal
- Department of Neurology, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Ulrike Kaunzner
- Department of Neurology, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Ilana L. Brito
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, USA
| | - Zhengming Chen
- Division of Biostatistics, Department of Population Health Sciences, and
| | - Jenny Z. Xiang
- Genomics Resources Core Facility, Core Laboratories Center, Weill Cornell Medicine, New York, New York, USA
| | - Doron Betel
- Applied Bioinformatics Core, Division of Hematology/Oncology, Department of Medicine, Institute for Computational Biomedicine, Weill Cornell Medicine, New York, New York, USA
- Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Richard Daneman
- Departments of Pharmacology and Neurosciences, UCSD, San Diego, California, USA
| | - Gregory F. Sonnenberg
- Jill Roberts Institute for Research in Inflammatory Bowel Disease
- Joan and Sanford I. Weill Department of Medicine, and
- Department of Microbiology and Immunology, Weill Cornell Medical College, Cornell University, New York, New York, USA
- Immunology and Microbial Pathogenesis Program and
| | - Christopher E. Mason
- Feil Family Brain and Mind Research Institute
- Physiology and Biophysics, Institute for Computational Biomedicine, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Timothy Vartanian
- Feil Family Brain and Mind Research Institute
- Immunology and Microbial Pathogenesis Program and
- Department of Neurology, Weill Cornell Medical College, Cornell University, New York, New York, USA
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Talukdar PK, Sarker MR. Characterization of Putative Sporulation and Germination Genes in Clostridium perfringens Food-Poisoning Strain SM101. Microorganisms 2022; 10:microorganisms10081481. [PMID: 35893539 PMCID: PMC9332280 DOI: 10.3390/microorganisms10081481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/20/2022] [Accepted: 07/20/2022] [Indexed: 12/10/2022] Open
Abstract
Bacterial sporulation and spore germination are two intriguing processes that involve the expression of many genes coherently. Phylogenetic analyses revealed gene conservation among spore-forming Firmicutes, especially in Bacilli and Clostridia. In this study, by homology search, we found Bacillus subtilis sporulation gene homologs of bkdR, ylmC, ylxY, ylzA, ytaF, ytxC, yyaC1, and yyaC2 in Clostridium perfringenes food-poisoning Type F strain SM101. The β-glucuronidase reporter assay revealed that promoters of six out of eight tested genes (i.e., bkdR, ylmC, ytaF, ytxC, yyaC1, and yyaC2) were expressed only during sporulation, but not vegetative growth, suggesting that these genes are sporulation-specific. Gene knock-out studies demonstrated that C. perfringens ΔbkdR, ΔylmC, ΔytxC, and ΔyyaC1 mutant strains produced a significantly lower number of spores compared to the wild-type strain. When the spores of these six mutant strains were examined for their germination abilities in presence of known germinants, an almost wild-type level germination was observed with spores of ΔytaF or ΔyyaC1 mutants; and a slightly lower level with spores of ΔbkdR or ΔylmC mutants. In contrast, almost no germination was observed with spores of ΔytxC or ΔyyaC2 mutants. Consistent with germination defects, ΔytxC or ΔyyaC2 spores were also defective in spore outgrowth and colony formation. The germination, outgrowth, and colony formation defects of ΔytxC or ΔyyaC2 spores were restored when ΔytxC or ΔyyaC2 mutant was complemented with wild-type ytxC or yyaC2, respectively. Collectively, our current study identified new sporulation and germination genes in C. perfringens.
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Affiliation(s)
- Prabhat K. Talukdar
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
- Department of Microbiology, College of Science, Oregon State University, Corvallis, OR 97331, USA
- Correspondence: (P.K.T.); (M.R.S.); Tel.: +1-509-335-4029 (P.K.T.); +1-541-737-6918 (M.R.S.)
| | - Mahfuzur R. Sarker
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
- Department of Microbiology, College of Science, Oregon State University, Corvallis, OR 97331, USA
- Correspondence: (P.K.T.); (M.R.S.); Tel.: +1-509-335-4029 (P.K.T.); +1-541-737-6918 (M.R.S.)
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Regulatory Networks Controlling Neurotoxin Synthesis in Clostridium botulinum and Clostridium tetani. Toxins (Basel) 2022; 14:toxins14060364. [PMID: 35737025 PMCID: PMC9229411 DOI: 10.3390/toxins14060364] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/16/2022] [Accepted: 05/21/2022] [Indexed: 12/30/2022] Open
Abstract
Clostridium botulinum and Clostridium tetani are Gram-positive, spore-forming, and anaerobic bacteria that produce the most potent neurotoxins, botulinum toxin (BoNT) and tetanus toxin (TeNT), responsible for flaccid and spastic paralysis, respectively. The main habitat of these toxigenic bacteria is the environment (soil, sediments, cadavers, decayed plants, intestinal content of healthy carrier animals). C. botulinum can grow and produce BoNT in food, leading to food-borne botulism, and in some circumstances, C. botulinum can colonize the intestinal tract and induce infant botulism or adult intestinal toxemia botulism. More rarely, C. botulinum colonizes wounds, whereas tetanus is always a result of wound contamination by C. tetani. The synthesis of neurotoxins is strictly regulated by complex regulatory networks. The highest levels of neurotoxins are produced at the end of the exponential growth and in the early stationary growth phase. Both microorganisms, except C. botulinum E, share an alternative sigma factor, BotR and TetR, respectively, the genes of which are located upstream of the neurotoxin genes. These factors are essential for neurotoxin gene expression. C. botulinum and C. tetani share also a two-component system (TCS) that negatively regulates neurotoxin synthesis, but each microorganism uses additional distinct sets of TCSs. Neurotoxin synthesis is interlocked with the general metabolism, and CodY, a master regulator of metabolism in Gram-positive bacteria, is involved in both clostridial species. The environmental and nutritional factors controlling neurotoxin synthesis are still poorly understood. The transition from amino acid to peptide metabolism seems to be an important factor. Moreover, a small non-coding RNA in C. tetani, and quorum-sensing systems in C. botulinum and possibly in C. tetani, also control toxin synthesis. However, both species use also distinct regulatory pathways; this reflects the adaptation of C. botulinum and C. tetani to different ecological niches.
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Small Prokaryotic DNA-Binding Proteins Protect Genome Integrity throughout the Life Cycle. Int J Mol Sci 2022; 23:ijms23074008. [PMID: 35409369 PMCID: PMC8999374 DOI: 10.3390/ijms23074008] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/27/2022] [Accepted: 04/01/2022] [Indexed: 12/17/2022] Open
Abstract
Genomes of all organisms are persistently threatened by endogenous and exogenous assaults. Bacterial mechanisms of genome maintenance must provide protection throughout the physiologically distinct phases of the life cycle. Spore-forming bacteria must also maintain genome integrity within the dormant endospore. The nucleoid-associated proteins (NAPs) influence nucleoid organization and may alter DNA topology to protect DNA or to alter gene expression patterns. NAPs are characteristically multifunctional; nevertheless, Dps, HU and CbpA are most strongly associated with DNA protection. Archaea display great variety in genome organization and many inhabit extreme environments. As of yet, only MC1, an archaeal NAP, has been shown to protect DNA against thermal denaturation and radiolysis. ssDNA are intermediates in vital cellular processes, such as DNA replication and recombination. Single-stranded binding proteins (SSBs) prevent the formation of secondary structures but also protect the hypersensitive ssDNA against chemical and nuclease degradation. Ionizing radiation upregulates SSBs in the extremophile Deinococcus radiodurans.
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Abstract
Soil microbes are considered the second genome of plants. Understanding the distribution and network of aluminum (Al)-tolerant microorganisms is helpful to alleviate Al toxicity to plants in acidic soils. Here, we examined soluble Al3+ and bacterial communities carrying Al resistance genes in paddy soils with a soil pH range of 3.6 to 8.7. In the acidic soil with pH <5.1, the content of Al3+ increased significantly. There were abundant and diverse Al-tolerant microorganisms in acidic soils, including Clostridium, Bacillus, Paenibacillus, Desulfitobacterium, and Desulfosporosinus, etc. Moreover, compared with neutral and alkaline soils, the network structure of Al-tolerant microorganisms was more complex. The potential roles of major Al-tolerant microbial taxa on each other in the ecological network were identified by a directed network along 0.01 pH steps. The influential taxa in the network had a broader niche and contained more antioxidant functional genes to resist Al stress, indicating their survival advantage over the sensitive taxa. Our study is the first to explore the distribution of Al-tolerant microorganisms in continental paddies and reveal their potential associations mediated by pH, which provides a basis for further utilization of microbial resources in acidic agricultural soils. IMPORTANCE Aluminum (Al) toxicity is the primary limiting factor of crop production in acidic soils with pH <5.0. Numerous studies have focused on the mechanism of Al toxicity and tolerance in plants; however, the effects of Al toxicity on soil microorganisms and their tolerance remain less studied. This study investigated the distribution and association patterns of Al-tolerant microorganisms across continental paddy fields with a soil pH range of 3.6 to 8.7. The results showed that soil pH filters exchangeable Al3+ content, diversity, and potential associations of Al-tolerant microbial community. The influential taxa in community network play an important role in Al tolerance and have potential applications in mitigating Al toxicity and promoting crop growth in acidic soils.
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When anaerobes encounter oxygen: mechanisms of oxygen toxicity, tolerance and defence. Nat Rev Microbiol 2021; 19:774-785. [PMID: 34183820 PMCID: PMC9191689 DOI: 10.1038/s41579-021-00583-y] [Citation(s) in RCA: 84] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2021] [Indexed: 02/06/2023]
Abstract
The defining trait of obligate anaerobes is that oxygen blocks their growth, yet the underlying mechanisms are unclear. A popular hypothesis was that these microorganisms failed to evolve defences to protect themselves from reactive oxygen species (ROS) such as superoxide and hydrogen peroxide, and that this failure is what prevents their expansion to oxic habitats. However, studies reveal that anaerobes actually wield most of the same defences that aerobes possess, and many of them have the capacity to tolerate substantial levels of oxygen. Therefore, to understand the structures and real-world dynamics of microbial communities, investigators have examined how anaerobes such as Bacteroides, Desulfovibrio, Pyrococcus and Clostridium spp. struggle and cope with oxygen. The hypoxic environments in which these organisms dwell - including the mammalian gut, sulfur vents and deep sediments - experience episodic oxygenation. In this Review, we explore the molecular mechanisms by which oxygen impairs anaerobes and the degree to which bacteria protect their metabolic pathways from it. The emergent view of anaerobiosis is that optimal strategies of anaerobic metabolism depend upon radical chemistry and low-potential metal centres. Such catalytic sites are intrinsically vulnerable to direct poisoning by molecular oxygen and ROS. Observations suggest that anaerobes have evolved tactics that either minimize the extent to which oxygen disrupts their metabolism or restore function shortly after the stress has dissipated.
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Kinetics of ABE fermentation considering the different phenotypes present in a batch culture of Clostridium beijerinckii NCIMB-8052. ELECTRON J BIOTECHN 2021. [DOI: 10.1016/j.ejbt.2021.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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12
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Nerber HN, Sorg JA. The small acid-soluble proteins of Clostridioides difficile are important for UV resistance and serve as a check point for sporulation. PLoS Pathog 2021; 17:e1009516. [PMID: 34496003 PMCID: PMC8452069 DOI: 10.1371/journal.ppat.1009516] [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: 03/23/2021] [Revised: 09/20/2021] [Accepted: 09/01/2021] [Indexed: 12/17/2022] Open
Abstract
Clostridioides difficile is a nosocomial pathogen which causes severe diarrhea and colonic inflammation. C. difficile causes disease in susceptible patients when endospores germinate into the toxin-producing vegetative form. The action of these toxins results in diarrhea and the spread of spores into the hospital and healthcare environments. Thus, the destruction of spores is imperative to prevent disease transmission between patients. However, spores are resilient and survive extreme temperatures, chemical exposure, and UV treatment. This makes their elimination from the environment difficult and perpetuates their spread between patients. In the model spore-forming organism, Bacillus subtilis, the small acid-soluble proteins (SASPs) contribute to these resistances. The SASPs are a family of small proteins found in all endospore-forming organisms, C. difficile included. Although these proteins have high sequence similarity between organisms, the role(s) of the proteins differ. Here, we investigated the role of the main α/β SASPs, SspA and SspB, and two annotated putative SASPs, CDR20291_1130 and CDR20291_3080, in protecting C. difficile spores from environmental insults. We found that SspA is necessary for conferring spore UV resistance, SspB minorly contributes, and the annotated putative SASPs do not contribute to UV resistance. In addition, the SASPs minorly contribute to the resistance of nitrous acid. Surprisingly, the combined deletion of sspA and sspB prevented spore formation. Overall, our data indicate that UV resistance of C. difficile spores is dependent on SspA and that SspA and SspB regulate/serve as a checkpoint for spore formation, a previously unreported function of SASPs.
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Affiliation(s)
- Hailee N. Nerber
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Joseph A. Sorg
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
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13
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Jiang Y, Wu R, Lu J, Dong W, Zhou J, Zhang W, Xin F, Jiang M. Quantitative proteomic analysis to reveal expression differences for butanol production from glycerol and glucose by Clostridium sp. strain CT7. Microb Cell Fact 2021; 20:12. [PMID: 33422075 PMCID: PMC7797090 DOI: 10.1186/s12934-021-01508-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 01/02/2021] [Indexed: 11/16/2022] Open
Abstract
Clostridium sp. strain CT7 is a new emerging microbial cell factory with high butanol production ratio owing to its non-traditional butanol fermentation mode with uncoupled acetone and 1,3-propanediol formation. Significant changes of metabolic products profile were shown in glycerol- and glucose-fed strain CT7, especially higher butanol and lower volatile fatty acids (VFAs) production occurred from glycerol-fed one. However, the mechanism of this interesting phenomenon was still unclear. To better elaborate the bacterial response towards glycerol and glucose, the quantitative proteomic analysis through iTRAQ strategy was performed to reveal the regulated proteomic expression levels under different substrates. Proteomics data showed that proteomic expression levels related with carbon metabolism and solvent generation under glycerol media were highly increased. In addition, the up-regulation of hydrogenases, ferredoxins and electron-transferring proteins may attribute to the internal redox balance, while the earlier triggered sporulation response in glycerol-fed media may be associated with the higher butanol production. This study will pave the way for metabolic engineering of other industrial microorganisms to obtain efficient butanol production from glycerol.
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Affiliation(s)
- Yujia Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China
| | - Ruofan Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China
| | - Jiasheng Lu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, 211800, Nanjing, P.R. China
| | - Jie Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, 211800, Nanjing, P.R. China
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China. .,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, 211800, Nanjing, P.R. China.
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Puzhu South Road 30#, 211800, Nanjing, P. R. China. .,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, 211800, Nanjing, P.R. China.
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14
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Liang Q, Liu J, Wei J, Jia J, Shen H, Chen W, Liang W, Gao B, Xu Z, Zhang L. The effect of Clostridium tyrobutyricum Spo0A overexpression in the intestine of mice. Benef Microbes 2020; 11:573-589. [PMID: 33032473 DOI: 10.3920/bm2019.0131] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Clostridium tyrobutyricum shows probiotic properties and can affect the composition of gut microbiota and regulate the intestinal immune system. Compared with other probiotics, this spore-producing bacterium shows unparalleled advantages in commercial production. In addition to being resistant to extreme living environments for extended periods, its endophytic spores are implicated in inhibiting cancer cell growth. We speculated that C. tyrobutyricum spores can also promote gut health, which mean it can maintain intestinal homeostasis. To date, the beneficial effects of C. tyrobutyricum spores on gut health have not been reported. In this study, a Spo0A-overexpressing C. tyrobutyricum strain was developed to increase spore production, and its probiotic effects on the gut were assessed. Compared with the wild-type, the engineered strain showed significantly increased sporulation rates. Mice administered with the engineered strain exhibited enhanced intestinal villi and the villus height/crypt depth ratio, weight gain and improved Firmicutes/Bacteroidetes ratio to facilitate intestinal homeostasis. This study demonstrated for the first time that enhanced spore production in C. tyrobutyricum can improve intestinal homeostasis, which is advantageous for its commercial application in food and pharmaceutical industry.
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Affiliation(s)
- Q Liang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China P.R
| | - J Liu
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China P.R.,Guangdong Provincial Key Laboratory of Livestock and Poultry Disease Control, Guangdong Provincial Institute of Veterinary Public Health, Public Health Laboratory, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong 510642, China P.R
| | - J Wei
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China P.R
| | - J Jia
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China P.R
| | - H Shen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China P.R
| | - W Chen
- Guangdong Provincial Key Laboratory of Livestock and Poultry Disease Control, Guangdong Provincial Institute of Veterinary Public Health, Public Health Laboratory, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong 510642, China P.R
| | - W Liang
- Guangdong Provincial Key Laboratory of Livestock and Poultry Disease Control, Guangdong Provincial Institute of Veterinary Public Health, Public Health Laboratory, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong 510642, China P.R
| | - B Gao
- Guangdong Provincial Key Laboratory of Livestock and Poultry Disease Control, Guangdong Provincial Institute of Veterinary Public Health, Public Health Laboratory, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong 510642, China P.R
| | - Z Xu
- Guangdong Provincial Key Laboratory of Livestock and Poultry Disease Control, Guangdong Provincial Institute of Veterinary Public Health, Public Health Laboratory, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong 510642, China P.R
| | - L Zhang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China P.R.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China P.R
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15
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Impact of deoxycholate on Clostridioides difficile growth, toxin production, and sporulation. Heliyon 2020; 6:e03717. [PMID: 32322715 PMCID: PMC7160582 DOI: 10.1016/j.heliyon.2020.e03717] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/27/2020] [Accepted: 03/30/2020] [Indexed: 12/15/2022] Open
Abstract
Purpose Bile acids play an important role in Clostridioides difficile life cycle. Deoxycholate (DCA), one of the most abundant secondary bile acids, is known to inhibit vegetative growth and toxin production. However, limited data are available on the role of DCA on C. difficile sporulation. Here, we investigated the phenotypic and genotypic impact of DCA on the growth, toxin production, and sporulation of C. difficile. Methodology Four genetically divergent C. difficile strains were cultured in nutrient-rich broth with and without DCA at various concentrations, and growth activity was evaluated for each strain. Cytotoxicity assays using culture supernatants from cells grown in nutrient-rich broth with and without 0.01% DCA were conducted. Sporulation efficiency was determined using sporulation media with and without 0.01% DCA. Transcript levels of tcdB and spo0A were analyzed using quantitative reverse-transcription polymerase chain reaction. Results We found that DCA led to growth reduction in a dose-depended manner and regulated toxin production by repressing tcdB expression during vegetative growth. To our knowledge, we have also provided the first evidence that DCA reduces C. difficile sporulation efficiency through the downregulation of spo0A expression during the sporulation stage. Conclusions DCA modulates C. difficile sporulation, vegetative growth, and toxin production.
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16
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Ganguly J, Martin‐Pascual M, van Kranenburg R. CRISPR interference (CRISPRi) as transcriptional repression tool for Hungateiclostridium thermocellum DSM 1313. Microb Biotechnol 2020; 13:339-349. [PMID: 31802632 PMCID: PMC7017836 DOI: 10.1111/1751-7915.13516] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/06/2019] [Accepted: 11/12/2019] [Indexed: 01/13/2023] Open
Abstract
Hungateiclostridium thermocellum DSM 1313 has biotechnological potential as a whole-cell biocatalyst for ethanol production using lignocellulosic renewable sources. The full exploitation of H. thermocellum has been hampered due to the lack of simple and high-throughput genome engineering tools. Recently in our research group, a thermophilic bacterial CRISPR-Cas9-based system has been developed as a transcriptional suppression tool for regulation of gene expression. We applied ThermoCas9-based CRISPR interference (CRISPRi) to repress the H. thermocellum central metabolic lactate dehydrogenase (ldh) and phosphotransacetylase (pta) genes. The effects of repression on target genes were studied based on transcriptional expression and product formation. Single-guide RNA (sgRNA) under the control of native intergenic 16S/23S rRNA promoter from H. thermocellum directing the ThermodCas9 to the promoter region of both pta and ldh silencing transformants reduced expression up to 67% and 62% respectively. This resulted in 24% and 17% decrease in lactate and acetate production, correspondingly. Hence, the CRISPRi approach for H. thermocellum to downregulate metabolic genes can be used for remodelling of metabolic pathways without the requisite for genome engineering. These data established for the first time the feasibility of employing CRISPRi-mediated gene repression of metabolic genes in H. thermocellum DSM 1313.
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Affiliation(s)
| | - Maria Martin‐Pascual
- Laboratory of MicrobiologyWageningen UniversityStippeneng 46708WE WageningenThe Netherlands
| | - Richard van Kranenburg
- CorbionArkelsedijk 464206AC GorinchemThe Netherlands
- Laboratory of MicrobiologyWageningen UniversityStippeneng 46708WE WageningenThe Netherlands
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17
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Shen A, Edwards AN, Sarker MR, Paredes-Sabja D. Sporulation and Germination in Clostridial Pathogens. Microbiol Spectr 2019; 7:10.1128/microbiolspec.GPP3-0017-2018. [PMID: 31858953 PMCID: PMC6927485 DOI: 10.1128/microbiolspec.gpp3-0017-2018] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Indexed: 12/14/2022] Open
Abstract
As obligate anaerobes, clostridial pathogens depend on their metabolically dormant, oxygen-tolerant spore form to transmit disease. However, the molecular mechanisms by which those spores germinate to initiate infection and then form new spores to transmit infection remain poorly understood. While sporulation and germination have been well characterized in Bacillus subtilis and Bacillus anthracis, striking differences in the regulation of these processes have been observed between the bacilli and the clostridia, with even some conserved proteins exhibiting differences in their requirements and functions. Here, we review our current understanding of how clostridial pathogens, specifically Clostridium perfringens, Clostridium botulinum, and Clostridioides difficile, induce sporulation in response to environmental cues, assemble resistant spores, and germinate metabolically dormant spores in response to environmental cues. We also discuss the direct relationship between toxin production and spore formation in these pathogens.
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Affiliation(s)
- Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University Medical School, Boston, MA
| | - Adrianne N Edwards
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Mahfuzur R Sarker
- Department of Microbiology, College of Science, Oregon State University, Corvallis, OR
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR
| | - Daniel Paredes-Sabja
- Department of Gut Microbiota and Clostridia Research Group, Departamento de Ciencias Biolo gicas, Facultad de Ciencias Biologicas, Universidad Andres Bello, Santiago, Chile
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18
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Wang B, Peng W, Zhang P, Su J. The characteristics of Clostridium difficile ST81, a new PCR ribotype of toxin A- B+ strain with high-level fluoroquinolones resistance and higher sporulation ability than ST37/PCR ribotype 017. FEMS Microbiol Lett 2019; 365:5061623. [PMID: 30085003 DOI: 10.1093/femsle/fny168] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 07/28/2018] [Indexed: 12/30/2022] Open
Abstract
Antibiotic exposure, Clostridium difficile toxins, and spore formation are key factors involved in the pathogenesis of Clostridium difficile infection (CDI). A high incidence of CDI due to toxin A- B+ strains, which were classified into two genotypes (ST81 and ST37) by multilocus sequence typing, was identified in Beijing Friendship Hospital in 2016-2017. ST81 was the most prevalent type, accounting for 81.25% of toxin A- B+ strains. ST81 corresponded to a novel PCR ribotype, PKI-017, with one less band than ST37/ribotype 017 in PCR ribotyping. All ST81 strains showed a high level of ciprofloxacin resistance (MICs ≥ 64 μg mL-1) and moxifloxacin resistance (MICs ≥ 128 μg mL-1) with the amino acid substitutions Thr82 to Ile in GyrA and Ser416 to Ala in GyrB. There was either no mutation or only the single amino acid mutation Thr82 to Ile in the GyrA subunit of ST37/ribotype 017 strains, which had lower MICs of ciprofloxacin (4-64 μg mL-1) and moxifloxacin (4-16 μg mL-1). In addition, ST81 strains exhibited higher spore formation ability than ST37/ribotype 017 strains. Overall, our results indicated that ST81 strains had unique characteristics distinguishable from ST37 strains and emphasized the importance of ongoing surveillance for this new genotype.
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Affiliation(s)
- Baoya Wang
- Clinical Laboratory Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Wenwen Peng
- Clinical Laboratory Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Pingping Zhang
- Clinical Laboratory Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Jianrong Su
- Clinical Laboratory Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
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19
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Identification of an Important Orphan Histidine Kinase for the Initiation of Sporulation and Enterotoxin Production by Clostridium perfringens Type F Strain SM101. mBio 2019; 10:mBio.02674-18. [PMID: 30670619 PMCID: PMC6343041 DOI: 10.1128/mbio.02674-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Clostridium perfringens type F enteric diseases, which include a very common form of food poisoning and many cases of antibiotic-associated diarrhea, develop when type F strains sporulate and produce C. perfringens enterotoxin (CPE) in the intestines. Spores are also important for transmission of type F disease. Despite the importance of sporulation for type F disease and the evidence that C. perfringens sporulation begins with phosphorylation of the Spo0A transcriptional regulator, the kinase phosphorylating Spo0A to initiate sporulation and CPE production had not been ascertained. In response, the current report now provides identification of an orphan histidine kinase named CPR0195 that can directly phosphorylate Spo0A. Results using a CPR0195 null mutant indicate that this kinase is very important for initiating C. perfringens sporulation and CPE production. Therefore, the CPR0195 kinase represents a potential target to block type F disease by interfering with intestinal C. perfringens sporulation and CPE production. Clostridium perfringens type F strains cause a common human foodborne illness and many cases of nonfoodborne human gastrointestinal diseases. Sporulation plays two critical roles during type F enteric disease. First, it produces broadly resistant spores that facilitate type F strain survival in the food and nosocomial environments. Second, production of C. perfringens enterotoxin (CPE), the toxin responsible for causing the enteric symptoms of type F diseases, is restricted to cells in the process of sporulation. While later steps in the regulation of C. perfringens sporulation have been discerned, the process leading to phosphorylation of Spo0A, the master early regulator of sporulation and consequent CPE production, has remained unknown. Using an insertional mutagenesis approach, the current study identified the orphan histidine kinase CPR0195 as an important factor regulating C. perfringens sporulation and CPE production. Specifically, a CPR0195 null mutant of type F strain SM101 made 103-fold fewer spores than its wild-type parent and produced no detectable CPE. In contrast, a null mutant of another putative C. perfringens orphan histidine kinase (CPR1055) did not significantly affect sporulation or CPE production. Studies using a spoIIA operon promoter-driven reporter plasmid indicated that CPR0195 functions early during sporulation, i.e., prior to production of sporulation-associated sigma factors. Furthermore, in vitro studies showed that the CPR0195 kinase domain can autophosphorylate and phosphorylate Spo0A. These results support the idea of CPR0195 as an important kinase that initiates C. perfringens sporulation by directly phosphorylating Spo0A. This kinase could represent a novel therapeutic target to block C. perfringens sporulation and CPE production during type F disease.
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20
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Palleja A, Mikkelsen KH, Forslund SK, Kashani A, Allin KH, Nielsen T, Hansen TH, Liang S, Feng Q, Zhang C, Pyl PT, Coelho LP, Yang H, Wang J, Typas A, Nielsen MF, Nielsen HB, Bork P, Wang J, Vilsbøll T, Hansen T, Knop FK, Arumugam M, Pedersen O. Recovery of gut microbiota of healthy adults following antibiotic exposure. Nat Microbiol 2018; 3:1255-1265. [PMID: 30349083 DOI: 10.1038/s41564-018-0257-9] [Citation(s) in RCA: 402] [Impact Index Per Article: 67.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 08/28/2018] [Indexed: 12/18/2022]
Abstract
To minimize the impact of antibiotics, gut microorganisms harbour and exchange antibiotics resistance genes, collectively called their resistome. Using shotgun sequencing-based metagenomics, we analysed the partial eradication and subsequent regrowth of the gut microbiota in 12 healthy men over a 6-month period following a 4-day intervention with a cocktail of 3 last-resort antibiotics: meropenem, gentamicin and vancomycin. Initial changes included blooms of enterobacteria and other pathobionts, such as Enterococcus faecalis and Fusobacterium nucleatum, and the depletion of Bifidobacterium species and butyrate producers. The gut microbiota of the subjects recovered to near-baseline composition within 1.5 months, although 9 common species, which were present in all subjects before the treatment, remained undetectable in most of the subjects after 180 days. Species that harbour β-lactam resistance genes were positively selected for during and after the intervention. Harbouring glycopeptide or aminoglycoside resistance genes increased the odds of de novo colonization, however, the former also decreased the odds of survival. Compositional changes under antibiotic intervention in vivo matched results from in vitro susceptibility tests. Despite a mild yet long-lasting imprint following antibiotics exposure, the gut microbiota of healthy young adults are resilient to a short-term broad-spectrum antibiotics intervention and their antibiotics resistance gene carriage modulates their recovery processes.
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Affiliation(s)
- Albert Palleja
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Clinical-Microbiomics A/S, Copenhagen, Denmark
| | - Kristian H Mikkelsen
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Sofia K Forslund
- Experimental and Clinical Research Center, Charité-Universitätsmedizin Berlin and Max Delbruck Center for Molecular Medicine, Berlin, Germany.,Max Delbruck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Charité-Universitätsmedizin Berlin , Freie Universität Berlin Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany.,Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Alireza Kashani
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Danish Diabetes Academy, Odense, Denmark
| | - Kristine H Allin
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Epidemiology, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Trine Nielsen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tue H Hansen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Suisha Liang
- BGI-Shenzhen, Shenzhen, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Qiang Feng
- BGI-Shenzhen, Shenzhen, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Chenchen Zhang
- BGI-Shenzhen, Shenzhen, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Paul Theodor Pyl
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Luis Pedro Coelho
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Huanming Yang
- BGI-Shenzhen, Shenzhen, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China.,James D. Watson Institute of Genome Sciences, Hangzhou, China
| | - Jian Wang
- BGI-Shenzhen, Shenzhen, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China.,James D. Watson Institute of Genome Sciences, Hangzhou, China
| | - Athanasios Typas
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.,Genome Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Morten F Nielsen
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | | | - Peer Bork
- Max Delbruck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.,Molecular Medicine Partnership Unit, University of Heidelberg and European Molecular Biology Laboratory, Heidelberg, Germany.,Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jun Wang
- iCarbonX, Shenzhen, China.,Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.,Department of Biology, University of Copenhagen, Copenhagen, Denmark.,State Key Laboratory of Quality Research in Chinese Medicine/Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Avenida Wai Long, Taipa Macau, China
| | - Tina Vilsbøll
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Torben Hansen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Filip K Knop
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. .,Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark. .,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Manimozhiyan Arumugam
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Oluf Pedersen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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21
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Davidson P, Eutsey R, Redler B, Hiller NL, Laub MT, Durand D. Flexibility and constraint: Evolutionary remodeling of the sporulation initiation pathway in Firmicutes. PLoS Genet 2018; 14:e1007470. [PMID: 30212463 PMCID: PMC6136694 DOI: 10.1371/journal.pgen.1007470] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 06/04/2018] [Indexed: 12/16/2022] Open
Abstract
The evolution of signal transduction pathways is constrained by the requirements of signal fidelity, yet flexibility is necessary to allow pathway remodeling in response to environmental challenges. A detailed understanding of how flexibility and constraint shape bacterial two component signaling systems is emerging, but how new signal transduction architectures arise remains unclear. Here, we investigate pathway remodeling using the Firmicute sporulation initiation (Spo0) pathway as a model. The present-day Spo0 pathways in Bacilli and Clostridia share common ancestry, but possess different architectures. In Clostridium acetobutylicum, sensor kinases directly phosphorylate Spo0A, the master regulator of sporulation. In Bacillus subtilis, Spo0A is activated via a four-protein phosphorelay. The current view favors an ancestral direct phosphorylation architecture, with the phosphorelay emerging in the Bacillar lineage. Our results reject this hypothesis. Our analysis of 84 broadly distributed Firmicute genomes predicts phosphorelays in numerous Clostridia, contrary to the expectation that the Spo0 phosphorelay is unique to Bacilli. Our experimental verification of a functional Spo0 phosphorelay encoded by Desulfotomaculum acetoxidans (Class Clostridia) further supports functional phosphorelays in Clostridia, which strongly suggests that the ancestral Spo0 pathway was a phosphorelay. Cross complementation assays between Bacillar and Clostridial phosphorelays demonstrate conservation of interaction specificity since their divergence over 2.7 BYA. Further, the distribution of direct phosphorylation Spo0 pathways is patchy, suggesting multiple, independent instances of remodeling from phosphorelay to direct phosphorylation. We provide evidence that these transitions are likely the result of changes in sporulation kinase specificity or acquisition of a sensor kinase with specificity for Spo0A, which is remarkably conserved in both architectures. We conclude that flexible encoding of interaction specificity, a phenotype that is only intermittently essential, and the recruitment of kinases to recognize novel environmental signals resulted in a consistent and repeated pattern of remodeling of the Spo0 pathway. Survival in a changing world requires signal transduction circuitry that can evolve to sense and respond to new environmental challenges. The Firmicute sporulation initiation (Spo0) pathway is a compelling example of a pathway with a circuit diagram that has changed over the course of evolution. In Clostridium acetobutylicum, a sensor kinase directly activates the master regulator of sporulation, Spo0A. In Bacillus subtilis, Spo0A is activated indirectly via a four-protein phosphorelay. These early observations suggested that the ancestral Spo0A was directly phosphorylated by a kinase in the earliest spore-former and that the Spo0 phosphorelay arose later in Bacilli via gain of additional proteins and interactions. Our analysis, based on a much larger set of genomes, surprisingly reveals phosphorelays, not only in Bacilli, but in many Clostridia. These findings support a model wherein sporulation was initiated by a Spo0 phosphorelay in the ancestral spore-former and the direct phosphorylation Spo0 pathways, which are observed in distinct sets of Clostridial taxa, are the result of convergent, reductive evolution. Further, our evidence suggests that these remodeling events were mediated by changes in kinase specificity, implicating flexible pathway remodeling, potentially combined with the recruitment of kinases, in Spo0 pathway evolution.
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Affiliation(s)
- Philip Davidson
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Rory Eutsey
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Brendan Redler
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - N. Luisa Hiller
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- Center of Excellence in Biofilm Research, Allegheny Health Network, Pittsburgh, Pennsylvania, United States of America
| | - Michael T. Laub
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Dannie Durand
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- Department of Computer Science, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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22
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Saito R, Talukdar PK, Alanazi SS, Sarker MR. RelA/DTD-mediated regulation of spore formation and toxin production by Clostridium perfringens type A strain SM101. MICROBIOLOGY-SGM 2018; 164:835-847. [PMID: 29624163 DOI: 10.1099/mic.0.000655] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
RelA is a global regulator for stationary phase development in the model bacterium Bacillus subtilis. The relA gene forms a bicistronic operon with the downstream dtd gene. In this study, we evaluated the significance of RelA and DTD proteins in spore formation and toxin production by an important gastrointestinal pathogen Clostridium perfringens. Our β-glucuronidase assay showed that in C. perfringens strain SM101, relA forms a bicistronic operon with its downstream dtd gene, and the relA promoter is expressed during both vegetative and sporulation conditions. By constructing double relA dtd and single dtd mutants in C. perfringens SM101, we found that: (1) RelA is required for maintaining the efficient growth capacity of SM101 cells during vegetative conditions; (2) both RelA and DTD are required for spore formation and enterotoxin (CPE) production by SM101; (3) RelA/DTD activate CodY, which is known to activate spore formation and CPE production in SM101 by activating a key sporulation-specific σ factor F; (4) as expected, RelA/DTD activate sporulation-specific σ factors (σE, σF, σG and σK) by positively regulating Spo0A production; and finally (5) RelA, but not DTD, negatively regulates phospholipase C (PLC) production by repressing plc gene expression. Collectively, our results demonstrate that RelA modulates cellular physiology such as growth, spore formation and toxin production by C. perfringens type A strain SM101, although DTD also plays a role in these pleiotropic functions in coordination with RelA during sporulation. These findings have implications for the understanding of the mechanisms involved in the infectious cycle of C. perfringens.
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Affiliation(s)
- Ryoichi Saito
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA.,Department of Microbiology and Immunology, Field of Applied Laboratory Science, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Prabhat K Talukdar
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA.,Department of Microbiology, College of Science, Oregon State University, Corvallis, OR, USA.,Present address: School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
| | - Saud S Alanazi
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA.,Department of Microbiology, College of Science, Oregon State University, Corvallis, OR, USA
| | - Mahfuzur R Sarker
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA.,Department of Microbiology, College of Science, Oregon State University, Corvallis, OR, USA
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23
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Stein UH, Wimmer B, Ortner M, Fuchs W, Bochmann G. Maximizing the production of butyric acid from food waste as a precursor for ABE-fermentation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 598:993-1000. [PMID: 28468123 DOI: 10.1016/j.scitotenv.2017.04.139] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 03/31/2017] [Accepted: 04/19/2017] [Indexed: 06/07/2023]
Abstract
The current study reports on the maximization of butyric acid production from food waste using a mixed microbial fermentation. In semi-continuous fermentations the effect of three different pH values (5.5, 7.0 and 9.0), three different temperatures (37°C, 55°C and 70°C) and two levels of hydraulic retention time (HRT, 2days and 6days) on the formation of butyric acid as well as total volatile fatty acid production (tVFA) were investigated. Overall, pH5.5 provided the lowest butyric acid concentrations regardless of the temperature and the HRT. At mesophilic temperature (37°C) alkaline conditions (pH9.0) lead to a strong incline of tVFA as well as butyric acid concentration probably due to a decreased solubilization of the substrate. However, most efficient in terms of butyric acid production was the fermentation conducted at 55°C and pH7 where a butyric acid concentrations of 10.55g/L (HRT 2days) and 13.00g/L (HRT 6days) were achieved. Additional experiments at 70°C showed declining butyric acid production. Increase of the HRT from 2days to 6days provided an increment of butyric acid concentration throughout almost all experimental settings. However, regarding volumetric productivity the increase in concentration does not compensate for the bigger reactor volume required to establish a higher HRT. At pH7 and 55°C the resulting volumetric production rates were 5.27g/L∗d at a HRT 2days and only 2.17g/L∗d at a HRT of 6days.
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Affiliation(s)
- Ullrich Heinz Stein
- University of Natural Resources and Life Sciences, Institute for Environmental Biotechnology, Vienna, Austria.
| | - B Wimmer
- University of Natural Resources and Life Sciences, Institute for Environmental Biotechnology, Vienna, Austria
| | - M Ortner
- Bioenergy 2020+ GmbH, Graz, Austria
| | - W Fuchs
- University of Natural Resources and Life Sciences, Institute for Environmental Biotechnology, Vienna, Austria
| | - G Bochmann
- University of Natural Resources and Life Sciences, Institute for Environmental Biotechnology, Vienna, Austria
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24
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Thomas P, Semmler T, Eichhorn I, Lübke-Becker A, Werckenthin C, Abdel-Glil MY, Wieler LH, Neubauer H, Seyboldt C. First report of two complete Clostridium chauvoei genome sequences and detailed in silico genome analysis. INFECTION GENETICS AND EVOLUTION 2017; 54:287-298. [PMID: 28720440 DOI: 10.1016/j.meegid.2017.07.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 07/12/2017] [Accepted: 07/13/2017] [Indexed: 12/28/2022]
Abstract
Clostridium (C.) chauvoei is a Gram-positive, spore forming, anaerobic bacterium. It causes black leg in ruminants, a typically fatal histotoxic myonecrosis. High quality circular genome sequences were generated for the C. chauvoei type strain DSM 7528T (ATCC 10092T) and a field strain 12S0467 isolated in Germany. The origin of replication (oriC) was comparable to that of Bacillus subtilis in structure with two regions containing DnaA boxes. Similar prophages were identified in the genomes of both C. chauvoei strains which also harbored hemolysin and bacterial spore formation genes. A CRISPR type I-B system with limited variations in the repeat number was identified. Sporulation and germination process related genes were homologous to that of the Clostridia cluster I group but novel variations for regulatory genes were identified indicative for strain specific control of regulatory events. Phylogenomics showed a higher relatedness to C. septicum than to other so far sequenced genomes of species belonging to the genus Clostridium. Comparative genome analysis of three C. chauvoei circular genome sequences revealed the presence of few inversions and translocations in locally collinear blocks (LCBs). The species genome also shows a large number of genes involved in proteolysis, genes for glycosyl hydrolases and metal iron transportation genes which are presumably involved in virulence and survival in the host. Three conserved flagellar genes (fliC) were identified in each of the circular genomes. In conclusion this is the first comparative analysis of circular genomes for the species C. chauvoei, enabling insights into genome composition and virulence factor variation.
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Affiliation(s)
- Prasad Thomas
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Naumburger Str. 96A, 07743 Jena, Germany.
| | | | - Inga Eichhorn
- Institute of Microbiology and Epizootics, Department of Veterinary Medicine, Freie Universität, Robert-von-Ostertag-Str. 7-13, Building 35, 14163, Berlin, Germany.
| | - Antina Lübke-Becker
- Institute of Microbiology and Epizootics, Department of Veterinary Medicine, Freie Universität, Robert-von-Ostertag-Str. 7-13, Building 35, 14163, Berlin, Germany.
| | - Christiane Werckenthin
- LAVES, Lebensmittel- und Veterinärinstitut Oldenburg, Martin-Niemöller-Straße 2, 26133 Oldenburg, Germany.
| | - Mostafa Y Abdel-Glil
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Naumburger Str. 96A, 07743 Jena, Germany.
| | | | - Heinrich Neubauer
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Naumburger Str. 96A, 07743 Jena, Germany.
| | - Christian Seyboldt
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Naumburger Str. 96A, 07743 Jena, Germany.
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25
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Gauvry E, Mathot AG, Leguérinel I, Couvert O, Postollec F, Broussolle V, Coroller L. Knowledge of the physiology of spore-forming bacteria can explain the origin of spores in the food environment. Res Microbiol 2017; 168:369-378. [DOI: 10.1016/j.resmic.2016.10.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 07/22/2016] [Accepted: 10/18/2016] [Indexed: 10/20/2022]
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26
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Metagenomic and Metatranscriptomic Analyses Reveal the Structure and Dynamics of a Dechlorinating Community Containing Dehalococcoides mccartyi and Corrinoid-Providing Microorganisms under Cobalamin-Limited Conditions. Appl Environ Microbiol 2017; 83:AEM.03508-16. [PMID: 28188205 DOI: 10.1128/aem.03508-16] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 02/04/2017] [Indexed: 12/21/2022] Open
Abstract
The aim of this study is to obtain a systems-level understanding of the interactions between Dehalococcoides and corrinoid-supplying microorganisms by analyzing community structures and functional compositions, activities, and dynamics in trichloroethene (TCE)-dechlorinating enrichments. Metagenomes and metatranscriptomes of the dechlorinating enrichments with and without exogenous cobalamin were compared. Seven putative draft genomes were binned from the metagenomes. At an early stage (2 days), more transcripts of genes in the Veillonellaceae bin-genome were detected in the metatranscriptome of the enrichment without exogenous cobalamin than in the one with the addition of cobalamin. Among these genes, sporulation-related genes exhibited the highest differential expression when cobalamin was not added, suggesting a possible release route of corrinoids from corrinoid producers. Other differentially expressed genes include those involved in energy conservation and nutrient transport (including cobalt transport). The most highly expressed corrinoid de novo biosynthesis pathway was also assigned to the Veillonellaceae bin-genome. Targeted quantitative PCR (qPCR) analyses confirmed higher transcript abundances of those corrinoid biosynthesis genes in the enrichment without exogenous cobalamin than in the enrichment with cobalamin. Furthermore, the corrinoid salvaging and modification pathway of Dehalococcoides was upregulated in response to the cobalamin stress. This study provides important insights into the microbial interactions and roles played by members of dechlorinating communities under cobalamin-limited conditions.IMPORTANCE The key chloroethene-dechlorinating bacterium Dehalococcoides mccartyi is a cobalamin auxotroph, thus acquiring corrinoids from other community members. Therefore, it is important to investigate the microbe-microbe interactions between Dehalococcoides and the corrinoid-providing microorganisms in a community. This study provides systems-level information, i.e., taxonomic and functional compositions and dynamics of the supportive microorganisms in dechlorinating communities under different cobalamin conditions. The findings shed light on the important roles of Veillonellaceae species in the communities compared to other coexisting community members in producing and providing corrinoids for Dehalococcoides species under cobalamin-limited conditions.
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Talukdar PK, Udompijitkul P, Hossain A, Sarker MR. Inactivation Strategies for Clostridium perfringens Spores and Vegetative Cells. Appl Environ Microbiol 2017; 83:e02731-16. [PMID: 27795314 PMCID: PMC5165105 DOI: 10.1128/aem.02731-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Clostridium perfringens is an important pathogen to human and animals and causes a wide array of diseases, including histotoxic and gastrointestinal illnesses. C. perfringens spores are crucial in terms of the pathogenicity of this bacterium because they can survive in a dormant state in the environment and return to being live bacteria when they come in contact with nutrients in food or the human body. Although the strategies to inactivate C. perfringens vegetative cells are effective, the inactivation of C. perfringens spores is still a great challenge. A number of studies have been conducted in the past decade or so toward developing efficient inactivation strategies for C. perfringens spores and vegetative cells, which include physical approaches and the use of chemical preservatives and naturally derived antimicrobial agents. In this review, different inactivation strategies applied to control C. perfringens cells and spores are summarized, and the potential limitations and challenges of these strategies are discussed.
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Affiliation(s)
- Prabhat K Talukdar
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
- Department of Microbiology, College of Science, Oregon State University, Corvallis, Oregon, USA
| | - Pathima Udompijitkul
- Department of Food Science and Technology, Faculty of Agro-Industry, Kasetsart University, Bangkok, Thailand
| | - Ashfaque Hossain
- Department of Medical Microbiology and Immunology, Ras Al Khaimah Medical and Health Sciences University, Ras Al Khaimah, United Arab Emirates
| | - Mahfuzur R Sarker
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
- Department of Microbiology, College of Science, Oregon State University, Corvallis, Oregon, USA
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28
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Yasugi M, Otsuka K, Miyake M. Nitrate salts suppress sporulation and production of enterotoxin in Clostridium perfringens strain NCTC8239. Microbiol Immunol 2016; 60:657-668. [PMID: 27594514 DOI: 10.1111/1348-0421.12437] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 08/17/2016] [Accepted: 09/01/2016] [Indexed: 11/29/2022]
Abstract
Clostridium perfringens type A is a common source of food-borne illness in humans. Ingested vegetative cells sporulate in the small intestinal tract and in the process produce C. perfringens enterotoxin (CPE). Although sporulation plays a critical role in the pathogenesis of food-borne illness, the molecules triggering/inhibiting sporulation are still largely unknown. It has previously been reported by our group that sporulation is induced in C. perfringens strain NCTC8239 co-cultured with Caco-2 cells in Dulbecco's Modified Eagle Medium (DMEM). In contrast, an equivalent amount of spores was not observed when bacteria were co-cultured in Roswell Park Memorial Institute-1640 medium (RPMI). In the present study it was found that, when these two media are mixed, RPMI inhibits sporulation and CPE production induced in DMEM. When a component of RPMI was added to DMEM, it was found that calcium nitrate (Ca[NO3 ]2 ) significantly inhibits sporulation and CPE production. The number of spores increased when Ca(NO3 )2 -deficient RPMI was used. The other nitrate salts significantly suppressed sporulation, whereas the calcium salts used did not. qPCR revealed that nitrate salts increased expression of bacterial nitrate/nitrite reductase. Furthermore, it was found that nitrite and nitric oxide suppress sporulation. In the sporulation stages, Ca(NO3 )2 down-regulated the genes controlled by Spo0A, a master regulator of sporulation, but not spo0A itself. Collectively, these results indicate that nitrate salts suppress sporulation and CPE production by down-regulating Spo0A-regulated genes in C. perfringens strain NCTC8239. Nitrate reduction may be associated with inhibition of sporulation.
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Affiliation(s)
- Mayo Yasugi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku Ourai Kita, Izumisano, Osaka 598-8531, Japan.
| | - Keisuke Otsuka
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku Ourai Kita, Izumisano, Osaka 598-8531, Japan
| | - Masami Miyake
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku Ourai Kita, Izumisano, Osaka 598-8531, Japan
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Transcriptional Profile during Deoxycholate-Induced Sporulation in a Clostridium perfringens Isolate Causing Foodborne Illness. Appl Environ Microbiol 2016; 82:2929-2942. [PMID: 26969700 DOI: 10.1128/aem.00252-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 03/03/2016] [Indexed: 01/05/2023] Open
Abstract
UNLABELLED Clostridium perfringens type A is a common source of foodborne illness (FBI) in humans. Vegetative cells sporulate in the small intestinal tract and produce the major pathogenic factor C. perfringens enterotoxin. Although sporulation plays a critical role in the pathogenesis of FBI, the mechanisms inducing sporulation remain unclear. Bile salts were shown previously to induce sporulation, and we confirmed deoxycholate (DCA)-induced sporulation in C. perfringens strain NCTC8239 cocultured with human intestinal epithelial Caco-2 cells. In the present study, we performed transcriptome analyses of strain NCTC8239 in order to elucidate the mechanism underlying DCA-induced sporulation. Of the 2,761 genes analyzed, 333 were up- or downregulated during DCA-induced sporulation and included genes for cell division, nutrient metabolism, signal transduction, and defense mechanisms. In contrast, the virulence-associated transcriptional regulators (the VirR/VirS system, the agr system, codY, and abrB) were not activated by DCA. DCA markedly increased the expression of signaling molecules controlled by Spo0A, the master regulator of the sporulation process, whereas the expression of spo0A itself was not altered in the presence or absence of DCA. The phosphorylation of Spo0A was enhanced in the presence of DCA. Collectively, these results demonstrated that DCA induced sporulation, at least partially, by facilitating the phosphorylation of Spo0A and activating Spo0A-regulated genes in strain NCTC8239 while altering the expression of various genes. IMPORTANCE Disease caused by Clostridium perfringens type A consistently ranks among the most common bacterial foodborne illnesses in humans in developed countries. The sporulation of C. perfringens in the small intestinal tract is a key event for its pathogenesis, but the factors and underlying mechanisms by which C. perfringens sporulates in vivo currently remain unclear. Bile salts, major components of bile, which is secreted from the liver for the emulsification of lipids, were shown to induce sporulation. However, the mechanisms underlying bile salt-induced sporulation have not yet been clarified. In the present study, we demonstrate that deoxycholate (one of the bile salts) induces sporulation by facilitating the phosphorylation of Spo0A and activating Spo0A-regulated genes using a transcriptome analysis. Thus, this study enhances our understanding of the mechanisms underlying sporulation, particularly that of bile salt-induced sporulation, in C. perfringens.
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30
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Clostridium perfringens Enterotoxin: Action, Genetics, and Translational Applications. Toxins (Basel) 2016; 8:toxins8030073. [PMID: 26999202 PMCID: PMC4810218 DOI: 10.3390/toxins8030073] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 03/04/2016] [Accepted: 03/08/2016] [Indexed: 12/21/2022] Open
Abstract
Clostridium perfringens enterotoxin (CPE) is responsible for causing the gastrointestinal symptoms of several C. perfringens food- and nonfood-borne human gastrointestinal diseases. The enterotoxin gene (cpe) is located on either the chromosome (for most C. perfringens type A food poisoning strains) or large conjugative plasmids (for the remaining type A food poisoning and most, if not all, other CPE-producing strains). In all CPE-positive strains, the cpe gene is strongly associated with insertion sequences that may help to assist its mobilization and spread. During disease, CPE is produced when C. perfringens sporulates in the intestines, a process involving several sporulation-specific alternative sigma factors. The action of CPE starts with its binding to claudin receptors to form a small complex; those small complexes then oligomerize to create a hexameric prepore on the membrane surface. Beta hairpin loops from the CPE molecules in the prepore assemble into a beta barrel that inserts into the membrane to form an active pore that enhances calcium influx, causing cell death. This cell death results in intestinal damage that causes fluid and electrolyte loss. CPE is now being explored for translational applications including cancer therapy/diagnosis, drug delivery, and vaccination.
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31
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Wells-Bennik MH, Eijlander RT, den Besten HM, Berendsen EM, Warda AK, Krawczyk AO, Nierop Groot MN, Xiao Y, Zwietering MH, Kuipers OP, Abee T. Bacterial Spores in Food: Survival, Emergence, and Outgrowth. Annu Rev Food Sci Technol 2016; 7:457-82. [DOI: 10.1146/annurev-food-041715-033144] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Marjon H.J. Wells-Bennik
- TI Food and Nutrition, 6700 AN Wageningen, The Netherlands
- NIZO Food Research, 6718 ZB Ede, The Netherlands;
| | - Robyn T. Eijlander
- TI Food and Nutrition, 6700 AN Wageningen, The Netherlands
- NIZO Food Research, 6718 ZB Ede, The Netherlands;
| | - Heidy M.W. den Besten
- TI Food and Nutrition, 6700 AN Wageningen, The Netherlands
- Laboratory of Food Microbiology, Wageningen University, 6700 AA Wageningen, The Netherlands
| | - Erwin M. Berendsen
- TI Food and Nutrition, 6700 AN Wageningen, The Netherlands
- NIZO Food Research, 6718 ZB Ede, The Netherlands;
- Molecular Genetics Department, University of Groningen, 9700 AB Groningen, The Netherlands
| | - Alicja K. Warda
- TI Food and Nutrition, 6700 AN Wageningen, The Netherlands
- Laboratory of Food Microbiology, Wageningen University, 6700 AA Wageningen, The Netherlands
- Wageningen UR Food & Biobased Research, 6700 AA Wageningen, The Netherlands
| | - Antonina O. Krawczyk
- TI Food and Nutrition, 6700 AN Wageningen, The Netherlands
- Molecular Genetics Department, University of Groningen, 9700 AB Groningen, The Netherlands
| | - Masja N. Nierop Groot
- TI Food and Nutrition, 6700 AN Wageningen, The Netherlands
- Wageningen UR Food & Biobased Research, 6700 AA Wageningen, The Netherlands
| | - Yinghua Xiao
- TI Food and Nutrition, 6700 AN Wageningen, The Netherlands
- Laboratory of Food Microbiology, Wageningen University, 6700 AA Wageningen, The Netherlands
| | - Marcel H. Zwietering
- TI Food and Nutrition, 6700 AN Wageningen, The Netherlands
- Laboratory of Food Microbiology, Wageningen University, 6700 AA Wageningen, The Netherlands
| | - Oscar P. Kuipers
- TI Food and Nutrition, 6700 AN Wageningen, The Netherlands
- Molecular Genetics Department, University of Groningen, 9700 AB Groningen, The Netherlands
| | - Tjakko Abee
- TI Food and Nutrition, 6700 AN Wageningen, The Netherlands
- Laboratory of Food Microbiology, Wageningen University, 6700 AA Wageningen, The Netherlands
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32
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Popoff MR. From saprophytic to toxigenic clostridia, a complex evolution based on multiple diverse genetic transfers and/or rearrangements. Res Microbiol 2015; 166:221-4. [PMID: 25744779 DOI: 10.1016/j.resmic.2015.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 02/20/2015] [Indexed: 11/15/2022]
Affiliation(s)
- Michel R Popoff
- Institut Pasteur, Unité des Bactéries anaérobies et Toxines, 25 rue du Dr Roux, 75724 Paris cedex 15, France.
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