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Schneier A, Melaugh G, Sadler JC. Engineered plastic-associated bacteria for biodegradation and bioremediation. BIOTECHNOLOGY FOR THE ENVIRONMENT 2024; 1:7. [PMID: 39026535 PMCID: PMC11256910 DOI: 10.1186/s44314-024-00007-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 04/29/2024] [Indexed: 07/20/2024]
Abstract
The global plastic waste crisis has triggered the development of novel methods for removal of recalcitrant polymers from the environment. Biotechnological approaches have received particular attention due to their potential for enabling sustainable, low-intensity bioprocesses which could also be interfaced with microbial upcycling pathways to support the emerging circular bioeconomy. However, low biodegradation efficiency of solid plastic materials remains a bottleneck, especially at mesophilic conditions required for one-pot degradation and upcycling. A promising strategy used in nature to address this is localisation of plastic-degrading microbes to the plastic surface via biofilm-mediated surface association. This review highlights progress and opportunities in leveraging these naturally occurring mechanisms of biofilm formation and other cell-surface adhesion biotechnologies to co-localise engineered cells to plastic surfaces. We further discuss examples of combining these approaches with extracellular expression of plastic-degrading enzymes to accelerate plastic degradation. Additionally, we review this topic in the context of nano- and microplastics bioremediation and their removal from wastewater and finally propose future research directions for this nascent field.
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Affiliation(s)
- Arianna Schneier
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Roger Land Building, Alexander Crum Brown Road, King’s Buildings, Edinburgh, EH9 3FF UK
| | - Gavin Melaugh
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3FD UK
- School of Engineering, University of Edinburgh, Edinburgh, EH9 3JL UK
| | - Joanna C. Sadler
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Roger Land Building, Alexander Crum Brown Road, King’s Buildings, Edinburgh, EH9 3FF UK
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2
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Ravishankar S, Baldelli V, Angeletti C, Raffaelli N, Landini P, Rossi E. Fluoropyrimidines affect de novo pyrimidine synthesis impairing biofilm formation in Escherichia coli. Biofilm 2024; 7:100180. [PMID: 38370152 PMCID: PMC10869245 DOI: 10.1016/j.bioflm.2024.100180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 01/24/2024] [Accepted: 01/29/2024] [Indexed: 02/20/2024] Open
Abstract
Antivirulence agents are considered a promising strategy to treat bacterial infections. Fluoropyrimidines possess antivirulence and antibiofilm activity against Gram-negative bacteria; however, their mechanism of action is yet unknown. Consistent with their known antibiofilm activity, fluoropyrimidines, particularly 5-fluorocytosine (5-FC), impair curli-dependent surface adhesion by Escherichia coli MG1655 via downregulation of curli fimbriae gene transcription. Curli inhibition requires fluoropyrimidine conversion into fluoronucleotides and is not mediated by c-di-GMP or the ymg-rcs envelope stress response axis, previously suggested as the target of fluorouracil antibiofilm activity in E. coli. In contrast, 5-FC hampered the transcription of curli activators RpoS and stimulated the expression of Fis, a curli repressor affected by nucleotide availability. This last observation suggested a possible perturbation of the de novo pyrimidine biosynthesis by 5-FC: indeed, exposure to 5-FC resulted in a ca. 2-fold reduction of UMP intracellular levels while not affecting ATP. Consistently, expression of the de novo pyrimidine biosynthesis genes carB and pyrB was upregulated in the presence of 5-FC. Our results suggest that the antibiofilm activity of fluoropyrimidines is mediated, at least in part, by perturbation of the pyrimidine nucleotide pool. We screened a genome library in search of additional determinants able to counteract the effects of 5-FC. We found that a DNA fragment encoding the unknown protein D8B36_18,480 and the N-terminal domain of the penicillin-binding protein 1b (PBP1b), involved in peptidoglycan synthesis, could restore curli production in the presence of 5-FC. Deletion of the PBP1b-encoding gene mrcB, induced csgBAC transcription, while overexpression of the gene encoding the D8B36_18,480 protein obliterated its expression, possibly as part of a coordinated response in curli regulation with PBP1b. While the two proteins do not appear to be direct targets of 5-FC, their involvement in curli regulation suggests a connection between peptidoglycan biosynthesis and curli production, which might become even more relevant upon pyrimidine starvation and reduced availability of UDP-sugars needed in cell wall biosynthesis. Overall, our findings link the antibiofilm activity of fluoropyrimidines to the redirection of at least two global regulators (RpoS, Fis) by induction of pyrimidine starvation. This highlights the importance of the de novo pyrimidines biosynthesis pathway in controlling virulence mechanisms in different bacteria and makes the pathway a potential target for antivirulence strategies.
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Affiliation(s)
| | | | - Carlo Angeletti
- Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Italy
| | - Nadia Raffaelli
- Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Italy
| | - Paolo Landini
- Department of Biosciences, University of Milan, Milan, Italy
| | - Elio Rossi
- Department of Biosciences, University of Milan, Milan, Italy
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3
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Xu L, Wang W, Zhang X, Ma K, Wang H, Xue T. Role of LsrR in the regulation of biofilm formation in mammary pathogenic Escherichia coli. BMC Vet Res 2024; 20:220. [PMID: 38783285 PMCID: PMC11112850 DOI: 10.1186/s12917-024-04086-9] [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: 01/28/2024] [Accepted: 05/16/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Mammary Pathogenic Escherichia coli (MPEC) is an important pathogen that can escape the attack of the host immune system through biofilm formation and proliferate in the mammary gland continuously, resulting in mastitis in cows and causing enormous economic losses. As an effector of AI-2 quorum sensing, LsrR extensively affects the expression levels of hundreds of genes related to multiple biological processes in model E. coli strain. However, the regulatory role of LsrR in MPEC and whether it is involved in pathogenesis has been seldom reported. RESULTS In this study, the function of LsrR in strain MPEC5, obtained from a milk sample in dairy cows with mastitis, was investigated by performing high-throughput sequencing (RNA-seq) assays. The results revealed that LsrR down-regulated the transcript levels of fimAICDFGH (encoding Type 1 pili), which have been reported to be associated with biofilm formation process. Biofilm assays confirmed that deletion of lsrR resulted in a significant increase in biofilm formation in vitro. In addition, electrophoretic mobility shift assay (EMSA) provided evidence that LsrR protein could directly bind to the promoter regions of fimAICDFGH in a dose-dependent manner. CONCLUSIONS These results indicate that LsrR protein inhibits the biofilm formation ability of MPEC5 by directly binding to the fimAICDFGH promoter region. This study presents a novel clue for further exploration of the prevention and treatment of MPEC.
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Affiliation(s)
- Li Xu
- School of Life Sciences, Anhui Agricultural University, Hefei,, Anhui, 230036, China
| | - Wei Wang
- School of Life Sciences, Anhui Agricultural University, Hefei,, Anhui, 230036, China
| | - Xin Zhang
- School of Life Sciences, Anhui Agricultural University, Hefei,, Anhui, 230036, China
| | - Kai Ma
- School of Life Sciences, Anhui Agricultural University, Hefei,, Anhui, 230036, China
| | - Hui Wang
- School of Life Sciences, Anhui Agricultural University, Hefei,, Anhui, 230036, China.
| | - Ting Xue
- School of Life Sciences, Anhui Agricultural University, Hefei,, Anhui, 230036, China.
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4
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Frizzell JK, Taylor RL, Ryno LM. Constitutive Activation of RpoH and the Addition of L-arabinose Influence Antibiotic Sensitivity of PHL628 E. coli. Antibiotics (Basel) 2024; 13:143. [PMID: 38391529 PMCID: PMC10886279 DOI: 10.3390/antibiotics13020143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 02/24/2024] Open
Abstract
Antibiotics are used to combat the ever-present threat of infectious diseases, but bacteria are continually evolving an assortment of defenses that enable their survival against even the most potent treatments. While the demand for novel antibiotic agents is high, the discovery of a new agent is exceedingly rare. We chose to focus on understanding how different signal transduction pathways in the gram-negative bacterium Escherichia coli (E. coli) influence the sensitivity of the organism to antibiotics from three different classes: tetracycline, chloramphenicol, and levofloxacin. Using the PHL628 strain of E. coli, we exogenously overexpressed two transcription factors, FliA and RpoH.I54N (a constitutively active mutant), to determine their influence on the minimum inhibitory concentration (MIC) and minimum duration of killing (MDK) concentration for each of the studied antibiotics. We hypothesized that activating these pathways, which upregulate genes that respond to specific stressors, could mitigate bacterial response to antibiotic treatment. We also compared the exogenous overexpression of the constitutively active RpoH mutant to thermal heat shock that has feedback loops maintained. While FliA overexpression had no impact on MIC or antibiotic tolerance, RpoH.I54N overexpression reduced the MIC for tetracycline and chloramphenicol but had no independent impact on antibiotic tolerance. Thermal heat shock alone also did not affect MIC or antibiotic tolerance. L-arabinose, the small molecule used to induce expression in our system, unexpectedly independently increased the MICs for tetracycline (>2-fold) and levofloxacin (3-fold). Additionally, the combination of thermal heat shock and arabinose provided a synergistic, 5-fold increase in MIC for chloramphenicol. Arabinose increased the tolerance, as assessed by MDK99, for chloramphenicol (2-fold) and levofloxacin (4-fold). These experiments highlight the potential of the RpoH pathway to modulate antibiotic sensitivity and the emerging implication of arabinose in enhanced MIC and antibiotic tolerance.
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Affiliation(s)
- Jenna K Frizzell
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH 44074, USA
| | - Ryan L Taylor
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH 44074, USA
| | - Lisa M Ryno
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH 44074, USA
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5
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Naz F, Ahmad A, Sarwar Y, Khan MM, Schierack P, Rauf W, Ali A. Characterization of Salmonella enterica Biofilms and Antibiofilm Effect of Carvacrol and 2-Aminobenzimidazole. Foodborne Pathog Dis 2024; 21:52-60. [PMID: 37819687 DOI: 10.1089/fpd.2023.0044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023] Open
Abstract
Biofilm-associated foodborne Salmonella infections in poultry have become increasingly challenging for veterinarians, particularly in developing countries, and warrant thorough investigation. We assessed the biofilm-forming tendency of poultry isolates of Salmonella enterica, namely Salmonella Typhimurium (n = 23), Salmonella Infantis (n = 28), and Salmonella Heidelberg (n = 18), in nutrient-rich Rappaport-Vassiliadis Soya (RVS) peptone broth and nutrient-deficient diluted Tryptone Soya Broth (TSB). Seven of the tested isolates exhibited moderate biofilm formation in diluted TSB, whereas two showed such formation in RVS. In addition, the Congo red agar assay revealed curli and cellulose production in seven isolates. Fourteen specific biofilm-associated genes were analyzed identifying sdiA and seqA to be the most prevalent (100%), and glyA the least prevalent (69.5%). The prevalence of the genes bcsA and csgA was significantly lower in moderate and weak biofilm formers, respectively, as compared with nonbiofilm formers in RVS peptone broth. Furthermore, the compounds carvacrol and 2-aminobenzimidazole (2-ABI) effectively inhibited biofilm formation by Salmonella serovars in RVS peptone and TSB media, respectively. Whereas the antibiofilm activity of 2-ABI against Salmonella has not been reported previously, we determined its most effective concentration at 1.5 mM among tested antibiofilm treatments. These findings indicate that Salmonella strains prevalent in poultry farms have the potential to form biofilms, and the tested compounds should be further explored as supportive or alternative antimicrobials.
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Affiliation(s)
- Fizza Naz
- Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering College, Pakistan Institute of Engineering and Applied Sciences (NIBGE-C, PIEAS), Faisalabad, Pakistan
| | - Abrar Ahmad
- Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering College, Pakistan Institute of Engineering and Applied Sciences (NIBGE-C, PIEAS), Faisalabad, Pakistan
| | - Yasra Sarwar
- Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering College, Pakistan Institute of Engineering and Applied Sciences (NIBGE-C, PIEAS), Faisalabad, Pakistan
| | - Muhammad Moman Khan
- Faculty Environment and Natural Sciences, Institute of Biotechnology, Brandenburg University of Technology Cottbus-Senftenberg, Senftenberg, Germany
| | - Peter Schierack
- Faculty Environment and Natural Sciences, Institute of Biotechnology, Brandenburg University of Technology Cottbus-Senftenberg, Senftenberg, Germany
- Faculty of Health Sciences, Joint Faculty of the Brandenburg University of Technology Cottbus-Senftenberg, the Brandenburg Medical School Theodor Fontane and the University of Potsdam, Potsdam, Germany
| | - Waqar Rauf
- Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering College, Pakistan Institute of Engineering and Applied Sciences (NIBGE-C, PIEAS), Faisalabad, Pakistan
| | - Aamir Ali
- Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering College, Pakistan Institute of Engineering and Applied Sciences (NIBGE-C, PIEAS), Faisalabad, Pakistan
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Li Y, Han S, Wang Y, Qin M, Lu C, Ma Y, Yang W, Liu J, Xia X, Wang H. Autoinducer-2 promotes adherence of Aeromonas veronii through facilitating the expression of MSHA type IV pili genes mediated by c-di-GMP. Appl Environ Microbiol 2023; 89:e0081923. [PMID: 37902393 PMCID: PMC10686060 DOI: 10.1128/aem.00819-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 09/19/2023] [Indexed: 10/31/2023] Open
Abstract
IMPORTANCE Aeromonas veronii can adhere to host cells through different adherence factors including outer-membrane proteins (OMPs), lipopolysaccharide (LPS), and pili, but its adherence mechanisms are still unclear. Here, we evaluated the effect of autoinducer-2 (AI-2) on adherence of A. veronii and its regulation mechanism. After determination of the promotion effect of AI-2 on adherence, we investigated which adherence factor was regulated by AI-2, and the results show that AI-2 only limits the formation of pili. Among the four distinct pili systems, only the mannose-sensitive hemagglutinin (MSHA) type IV pili genes were significantly downregulated after deficiency of AI-2. MshE, an ATPase belonged to MSHA type IV pilin, was confirmed as c-di-GMP receptor, that can bind with c-di-GMP which is positively regulated by AI-2, and the increase of c-di-GMP can promote the expression of MSHA type IV pili genes and adherence of A. veronii. Therefore, this study confirms that c-di-GMP positively regulated by AI-2 binds with MshE, then increases the expression of MSHA pili genes, finally promoting adherence of A. veronii, suggesting a multilevel positive regulatory adhesion mechanism that is responsible for A. veronii adherence.
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Affiliation(s)
- Yi Li
- College of Life Sciences, Henan Normal University, Xinxiang, China
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, Xinxiang, China
| | - Shuo Han
- College of Life Sciences, Henan Normal University, Xinxiang, China
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, Xinxiang, China
| | - Yuqi Wang
- College of Life Sciences, Henan Normal University, Xinxiang, China
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, Xinxiang, China
| | - Mengyuan Qin
- College of Life Sciences, Henan Normal University, Xinxiang, China
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, Xinxiang, China
| | - Chengjin Lu
- College of Life Sciences, Henan Normal University, Xinxiang, China
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, Xinxiang, China
| | - Yingke Ma
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Wenqing Yang
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Jiajia Liu
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Xiaohua Xia
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Hailei Wang
- College of Life Sciences, Henan Normal University, Xinxiang, China
- Henan Province Engineering Laboratory for Bioconversion Technology of Functional Microbes, Xinxiang, China
- Advanced Environmental Biotechnology Center, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, Singapore
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7
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Yaeger LN, French S, Brown ED, Côté JP, Burrows LL. Central metabolism is a key player in E. coli biofilm stimulation by sub-MIC antibiotics. PLoS Genet 2023; 19:e1011013. [PMID: 37917668 PMCID: PMC10645362 DOI: 10.1371/journal.pgen.1011013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 11/14/2023] [Accepted: 10/10/2023] [Indexed: 11/04/2023] Open
Abstract
Exposure of Escherichia coli to sub-inhibitory antibiotics stimulates biofilm formation through poorly characterized mechanisms. Using a high-throughput Congo Red binding assay to report on biofilm matrix production, we screened ~4000 E. coli K12 deletion mutants for deficiencies in this biofilm stimulation response. We screened using three different antibiotics to identify core components of the biofilm stimulation response. Mutants lacking acnA, nuoE, or lpdA failed to respond to sub-MIC cefixime and novobiocin, implicating central metabolism and aerobic respiration in biofilm stimulation. These genes are members of the ArcA/B regulon-controlled by a respiration-sensitive two-component system. Mutants of arcA and arcB had a 'pre-activated' phenotype, where biofilm formation was already high relative to wild type in vehicle control conditions, and failed to increase further with the addition of sub-MIC cefixime. Using a tetrazolium dye and an in vivo NADH sensor, we showed spatial co-localization of increased metabolic activity with sub-lethal concentrations of the bactericidal antibiotics cefixime and novobiocin. Supporting a role for respiratory stress, the biofilm stimulation response to cefixime and novobiocin was inhibited when nitrate was provided as an alternative electron acceptor. Deletion of a gene encoding part of the machinery for respiring nitrate abolished its ameliorating effects, and nitrate respiration increased during growth with sub-MIC cefixime. Finally, in probing the generalizability of biofilm stimulation, we found that the stimulation response to translation inhibitors, unlike other antibiotic classes, was minimally affected by nitrate supplementation, suggesting that targeting the ribosome stimulates biofilm formation in distinct ways. By characterizing the biofilm stimulation response to sub-MIC antibiotics at a systems level, we identified multiple avenues for design of therapeutics that impair bacterial stress management.
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Affiliation(s)
- Luke N. Yaeger
- Department of Biochemistry and Biomedical Sciences, and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Shawn French
- Department of Biochemistry and Biomedical Sciences, and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Eric D. Brown
- Department of Biochemistry and Biomedical Sciences, and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Jean Philippe Côté
- Department of Biochemistry and Biomedical Sciences, and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- Département de Biologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Lori L. Burrows
- Department of Biochemistry and Biomedical Sciences, and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
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Buchanan JA, Varghese NR, Johnston CL, Sunde M. Functional Amyloids: Where Supramolecular Amyloid Assembly Controls Biological Activity or Generates New Functionality. J Mol Biol 2023; 435:167919. [PMID: 37330295 DOI: 10.1016/j.jmb.2022.167919] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 12/05/2022] [Accepted: 12/05/2022] [Indexed: 06/19/2023]
Abstract
Functional amyloids are a rapidly expanding class of fibrillar protein structures, with a core cross-β scaffold, where novel and advantageous biological function is generated by the assembly of the amyloid. The growing number of amyloid structures determined at high resolution reveal how this supramolecular template both accommodates a wide variety of amino acid sequences and also imposes selectivity on the assembly process. The amyloid fibril can no longer be considered a generic aggregate, even when associated with disease and loss of function. In functional amyloids the polymeric β-sheet rich structure provides multiple different examples of unique control mechanisms and structures that are finely tuned to deliver assembly or disassembly in response to physiological or environmental cues. Here we review the range of mechanisms at play in natural, functional amyloids, where tight control of amyloidogenicity is achieved by environmental triggers of conformational change, proteolytic generation of amyloidogenic fragments, or heteromeric seeding and amyloid fibril stability. In the amyloid fibril form, activity can be regulated by pH, ligand binding and higher order protofilament or fibril architectures that impact the arrangement of associated domains and amyloid stability. The growing understanding of the molecular basis for the control of structure and functionality delivered by natural amyloids in nearly all life forms should inform the development of therapies for amyloid-associated diseases and guide the design of innovative biomaterials.
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Affiliation(s)
- Jessica A Buchanan
- School of Medical Sciences and Sydney Nano, The University of Sydney, NSW 2006, Australia.
| | - Nikhil R Varghese
- School of Medical Sciences and Sydney Nano, The University of Sydney, NSW 2006, Australia.
| | - Caitlin L Johnston
- School of Medical Sciences and Sydney Nano, The University of Sydney, NSW 2006, Australia.
| | - Margaret Sunde
- School of Medical Sciences and Sydney Nano, The University of Sydney, NSW 2006, Australia.
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9
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Wang G, Yin X, Feng Z, Chen C, Chen D, Wu B, Liu C, Morel JL, Jiang Y, Yu H, He H, Chao Y, Tang Y, Qiu R, Wang S. Novel biological aqua crust enhances in situ metal(loid) bioremediation driven by phototrophic/diazotrophic biofilm. MICROBIOME 2023; 11:110. [PMID: 37202810 DOI: 10.1186/s40168-023-01549-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 04/13/2023] [Indexed: 05/20/2023]
Abstract
BACKGROUND Understanding the ecological and environmental functions of phototrophic biofilms in the biological crust is crucial for improving metal(loid) (e.g. Cd, As) bioremediation in mining ecosystems. In this study, in combination with metal(loid) monitoring and metagenomic analysis, we systematically evaluated the effect of biofilm in a novel biological aqua crust (biogenic aqua crust-BAC) on in situ metal(loid) bioremediation of a representative Pb/Zn tailing pond. RESULTS We observed strong accumulation of potentially bioavailable metal(loid)s and visible phototrophic biofilms in the BAC. Furthermore, dominating taxa Leptolyngbyaceae (10.2-10.4%, Cyanobacteria) and Cytophagales (12.3-22.1%, Bacteroidota) were enriched in biofilm. Along with predominant heterotrophs (e.g. Cytophagales sp.) as well as diazotrophs (e.g. Hyphomonadaceae sp.), autotrophs/diazotrophs (e.g. Leptolyngbyaceae sp.) in phototrophic biofilm enriched the genes encoding extracellular peptidase (e.g. family S9, S1), CAZymes (e.g. CBM50, GT2) and biofilm formation (e.g. OmpR, CRP and LuxS), thus enhancing the capacity of nutrient accumulation and metal(loid) bioremediation in BAC system. CONCLUSIONS Our study demonstrated that a phototrophic/diazotrophic biofilm constitutes the structured communities containing specific autotrophs (e.g. Leptolyngbyaceae sp.) and heterotrophs (e.g. Cytophagales sp.), which effectively control metal(loid) and nutrient input using solar energy in aquatic environments. Elucidation of the mechanisms of biofilm formation coupled with metal(loid) immobilization in BAC expands the fundamental understanding of the geochemical fate of metal(loid)s, which may be harnessed to enhance in situ metal(loid) bioremediation in the aquatic ecosystem of the mining area. Video Abstract.
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Affiliation(s)
- Guobao Wang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Xiuran Yin
- Microbial Ecophysiology Group, University of Bremen, Bremen, Germany
| | - Zekai Feng
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Chiyu Chen
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Daijie Chen
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Bo Wu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Chong Liu
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China
| | - Jean Louis Morel
- Laboratoire Sols Et Environnement, UMR 1120, Université de Lorraine, INRAE, 54518, Vandoeuvre-Lès-Nancy, France
| | - Yuanyuan Jiang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Hang Yu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Huan He
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China
| | - Yuanqing Chao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Yetao Tang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Rongliang Qiu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China.
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China.
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China.
| | - Shizhong Wang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China.
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China.
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10
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Cho THS, Wang J, Raivio TL. NlpE Is an OmpA-Associated Outer Membrane Sensor of the Cpx Envelope Stress Response. J Bacteriol 2023; 205:e0040722. [PMID: 37022159 PMCID: PMC10127795 DOI: 10.1128/jb.00407-22] [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: 10/28/2022] [Accepted: 03/10/2023] [Indexed: 04/07/2023] Open
Abstract
Gram-negative bacteria utilize several envelope stress responses (ESRs) to sense and respond to diverse signals within a multilayered cell envelope. The CpxRA ESR responds to multiple stresses that perturb envelope protein homeostasis. Signaling in the Cpx response is regulated by auxiliary factors, such as the outer membrane (OM) lipoprotein NlpE, an activator of the response. NlpE communicates surface adhesion to the Cpx response; however, the mechanism by which NlpE accomplishes this remains unknown. In this study, we report a novel interaction between NlpE and the major OM protein OmpA. Both NlpE and OmpA are required to activate the Cpx response in surface-adhered cells. Furthermore, NlpE senses OmpA overexpression and the NlpE C-terminal domain transduces this signal to the Cpx response, revealing a novel signaling function for this domain. Mutation of OmpA peptidoglycan-binding residues abrogates signaling during OmpA overexpression, suggesting that NlpE signaling from the OM through the cell wall is coordinated via OmpA. Overall, these findings reveal NlpE to be a versatile envelope sensor that takes advantage of its structure, localization, and cooperation with other envelope proteins to initiate adaptation to diverse signals. IMPORTANCE The envelope is not only a barrier that protects bacteria from the environment but also a crucial site for the transduction of signals critical for colonization and pathogenesis. The discovery of novel complexes between NlpE and OmpA contributes to an emerging understanding of the key contribution of OM β-barrel protein and lipoprotein complexes to envelope stress signaling. Overall, our findings provide mechanistic insight into how the Cpx response senses signals relevant to surface adhesion and biofilm growth to facilitate bacterial adaptation.
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Affiliation(s)
- Timothy H. S. Cho
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Junshu Wang
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Tracy L. Raivio
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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11
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Ma W, Wang X, Zhang W, Hu X, Yang JL, Liang X. Two-Component System Response Regulator ompR Regulates Mussel Settlement through Exopolysaccharides. Int J Mol Sci 2023; 24:ijms24087474. [PMID: 37108636 PMCID: PMC10139040 DOI: 10.3390/ijms24087474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/12/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
The outer membrane protein (OMP) is a kind of biofilm matrix component that widely exists in Gram-negative bacteria. However, the mechanism of OMP involved in the settlement of molluscs is still unclear. In this study, the mussel Mytilus coruscus was selected as a model to explore the function of ompR, a two-component system response regulator, on Pseudoalteromonas marina biofilm-forming capacity and the mussel settlement. The motility of the ΔompR strain was increased, the biofilm-forming capacity was decreased, and the inducing activity of the ΔompR biofilms in plantigrades decreased significantly (p < 0.05). The extracellular α-polysaccharide and β-polysaccharide of the ΔompR strain decreased by 57.27% and 62.63%, respectively. The inactivation of the ompR gene decreased the ompW gene expression and had no impact on envZ expression or c-di-GMP levels. Adding recombinant OmpW protein caused the recovery of biofilm-inducing activities, accompanied by the upregulation of exopolysaccharides. The findings deepen the understanding of the regulatory mechanism of bacterial two-component systems and the settlement of benthic animals.
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Affiliation(s)
- Wei Ma
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-Culture of Aquaculture Animals, Shanghai 201306, China
| | - Xiaoyu Wang
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-Culture of Aquaculture Animals, Shanghai 201306, China
| | - Wen Zhang
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-Culture of Aquaculture Animals, Shanghai 201306, China
| | - Xiaomeng Hu
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-Culture of Aquaculture Animals, Shanghai 201306, China
| | - Jin-Long Yang
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-Culture of Aquaculture Animals, Shanghai 201306, China
| | - Xiao Liang
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Collaborative Innovation Center for Cultivating Elite Breeds and Green-Culture of Aquaculture Animals, Shanghai 201306, China
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12
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Sano K, Kobayashi H, Chuta H, Matsuyoshi N, Kato Y, Ogasawara H. CsgI (YccT) Is a Novel Inhibitor of Curli Fimbriae Formation in Escherichia coli Preventing CsgA Polymerization and Curli Gene Expression. Int J Mol Sci 2023; 24:ijms24054357. [PMID: 36901788 PMCID: PMC10002515 DOI: 10.3390/ijms24054357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 02/25/2023] Open
Abstract
Curli fimbriae are amyloids-found in bacteria (Escherichia coli)-that are involved in solid-surface adhesion and bacterial aggregation during biofilm formation. The curli protein CsgA is coded by a csgBAC operon gene, and the transcription factor CsgD is essential to induce its curli protein expression. However, the complete mechanism underlying curli fimbriae formation requires elucidation. Herein, we noted that curli fimbriae formation was inhibited by yccT-i.e., a gene that encodes a periplasmic protein of unknown function regulated by CsgD. Furthermore, curli fimbriae formation was strongly repressed by CsgD overexpression caused by a multicopy plasmid in BW25113-the non-cellulose-producing strain. YccT deficiency prevented these CsgD effects. YccT overexpression led to intracellular YccT accumulation and reduced CsgA expression. These effects were addressed by deleting the N-terminal signal peptide of YccT. Localization, gene expression, and phenotypic analyses revealed that YccT-dependent inhibition of curli fimbriae formation and curli protein expression was mediated by the two-component regulatory system EnvZ/OmpR. Purified YccT inhibited CsgA polymerization; however, no intracytoplasmic interaction between YccT and CsgA was detected. Thus, YccT-renamed CsgI (curli synthesis inhibitor)-is a novel inhibitor of curli fimbriae formation and has a dual role as an OmpR phosphorylation modulator and CsgA polymerization inhibitor.
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Affiliation(s)
- Kotaro Sano
- Research Center for Advanced Science and Technology, Division of Gene Research, Shinshu University, 3-15-1 Ueda, Nagano 386-8567, Japan
- Department of Applied Biology, Graduated School of Science and Technology, Shinshu University, 3-15-1 Ueda, Nagano 386-8567, Japan
| | - Hiroaki Kobayashi
- Research Center for Advanced Science and Technology, Division of Gene Research, Shinshu University, 3-15-1 Ueda, Nagano 386-8567, Japan
- Department of Applied Biology, Graduated School of Science and Technology, Shinshu University, 3-15-1 Ueda, Nagano 386-8567, Japan
| | - Hirotaka Chuta
- Research Center for Advanced Science and Technology, Division of Gene Research, Shinshu University, 3-15-1 Ueda, Nagano 386-8567, Japan
- Department of Applied Biology, Graduated School of Science and Technology, Shinshu University, 3-15-1 Ueda, Nagano 386-8567, Japan
| | - Nozomi Matsuyoshi
- Research Center for Advanced Science and Technology, Division of Gene Research, Shinshu University, 3-15-1 Ueda, Nagano 386-8567, Japan
- Department of Applied Biology, Graduated School of Science and Technology, Shinshu University, 3-15-1 Ueda, Nagano 386-8567, Japan
| | - Yuki Kato
- Research Center for Advanced Science and Technology, Division of Gene Research, Shinshu University, 3-15-1 Ueda, Nagano 386-8567, Japan
- Department of Applied Biology, Graduated School of Science and Technology, Shinshu University, 3-15-1 Ueda, Nagano 386-8567, Japan
| | - Hiroshi Ogasawara
- Research Center for Advanced Science and Technology, Division of Gene Research, Shinshu University, 3-15-1 Ueda, Nagano 386-8567, Japan
- Academic Assembly School of Humanities and Social Sciences Institute of Humanities, Shinshu University, Matsumoto 390-8621, Japan
- Institute for Fiber Engineering (IFES), Interdisciplinary Cluster for Cutting Edge Research (ICCER), Shinshu University, Tokida 3-15-1, Ueda, Nagano 386-8567, Japan
- Renaissance Center for Applied Microbiology, Shinshu University, Nagano-shi, Nagano 380-8553, Japan
- Correspondence: ; Tel.: +81-268-21-5803
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13
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In Vivo Role of Two-Component Regulatory Systems in Models of Urinary Tract Infections. Pathogens 2023; 12:pathogens12010119. [PMID: 36678467 PMCID: PMC9861413 DOI: 10.3390/pathogens12010119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/23/2022] [Accepted: 01/08/2023] [Indexed: 01/12/2023] Open
Abstract
Two-component signaling systems (TCSs) are finely regulated mechanisms by which bacteria adapt to environmental conditions by modifying the expression of target genes. In bacterial pathogenesis, TCSs play important roles in modulating adhesion to mucosal surfaces, resistance to antibiotics, and metabolic adaptation. In the context of urinary tract infections (UTI), one of the most common types infections causing significant health problems worldwide, uropathogens use TCSs for adaptation, survival, and establishment of pathogenicity. For example, uropathogens can exploit TCSs to survive inside bladder epithelial cells, sense osmolar variations in urine, promote their ascension along the urinary tract or even produce lytic enzymes resulting in exfoliation of the urothelium. Despite the usefulness of studying the function of TCSs in in vitro experimental models, it is of primary necessity to study bacterial gene regulation also in the context of host niches, each displaying its own biological, chemical, and physical features. In light of this, the aim of this review is to provide a concise description of several bacterial TCSs, whose activity has been described in mouse models of UTI.
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14
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Kiousi DE, Efstathiou C, Tzampazlis V, Plessas S, Panopoulou M, Koffa M, Galanis A. Genetic and phenotypic assessment of the antimicrobial activity of three potential probiotic lactobacilli against human enteropathogenic bacteria. Front Cell Infect Microbiol 2023; 13:1127256. [PMID: 36844407 PMCID: PMC9944596 DOI: 10.3389/fcimb.2023.1127256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 01/30/2023] [Indexed: 02/11/2023] Open
Abstract
Introduction Lactobacilli are avid producers of antimicrobial compounds responsible for their adaptation and survival in microbe-rich matrices. The bactericidal or bacteriostatic ability of lactic acid bacteria (LAB) can be exploited for the identification of novel antimicrobial compounds to be incorporated in functional foodstuffs or pharmaceutical supplements. In this study, the antimicrobial and antibiofilm properties of Lactiplantibacillus pentosus L33, Lactiplantibacillus plantarum L125 and Lacticaseibacillus paracasei SP5, previously isolated form fermented products, were examined, against clinical isolates of Staphylococcus aureus, Salmonella enterica subsp. enterica serovar Enteritidis and Escherichia coli. Methods The ability of viable cells to inhibit pathogen colonization on HT-29 cell monolayers, as well as their co-aggregation capacity, were examined utilizing the competitive exclusion assay. The antimicrobial activity of cell-free culture supernatants (CFCS) was determined against planktonic cells and biofilms, using microbiological assays, confocal microscopy, and gene expression analysis of biofilm formation-related genes. Furthermore, in vitro analysis was supplemented with in silico prediction of bacteriocin clusters and of other loci involved in antimicrobial activity. Results The three lactobacilli were able to limit the viability of planktonic cells of S. aureus and E. coli in suspension. Greater inhibition of biofilm formation was recorded after co-incubation of S. enterica with the CFCS of Lc. paracasei SP5. Predictions based on sequence revealed the ability of strains to produce single or two-peptide Class II bacteriocins, presenting sequence and structural conservation with functional bacteriocins. Discussion The efficiency of the potentially probiotic bacteria to elicit antimicrobial effects presented a strain- and pathogen-specific pattern. Future studies, utilizing multi-omic approaches, will focus on the structural and functional characterization of molecules involved in the recorded phenotypes.
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Affiliation(s)
- Despoina Eugenia Kiousi
- Department of Molecular Biology and Genetics, Faculty of Health Sciences, Democritus University of Thrace, Alexandroupolis, Greece
| | - Christos Efstathiou
- Department of Molecular Biology and Genetics, Faculty of Health Sciences, Democritus University of Thrace, Alexandroupolis, Greece
| | - Vasilis Tzampazlis
- Department of Molecular Biology and Genetics, Faculty of Health Sciences, Democritus University of Thrace, Alexandroupolis, Greece
| | - Stavros Plessas
- Department of Agricultural Development, Democritus University of Thrace, Orestiada, Greece
| | - Maria Panopoulou
- Department of Medicine, Faculty of Health Sciences, Democritus University of Thrace, Alexandroupolis, Greece
| | - Maria Koffa
- Department of Molecular Biology and Genetics, Faculty of Health Sciences, Democritus University of Thrace, Alexandroupolis, Greece
| | - Alex Galanis
- Department of Molecular Biology and Genetics, Faculty of Health Sciences, Democritus University of Thrace, Alexandroupolis, Greece
- *Correspondence: Alex Galanis,
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15
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Fu D, Wu J, Wu X, Shao Y, Song X, Tu J, Qi K. The two-component system histidine kinase EnvZ contributes to Avian pathogenic Escherichia coli pathogenicity by regulating biofilm formation and stress responses. Poult Sci 2022; 102:102388. [PMID: 36586294 PMCID: PMC9811210 DOI: 10.1016/j.psj.2022.102388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 11/24/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
EnvZ, the histidine kinase (HK) of OmpR/EnvZ, transduces osmotic signals in Escherichia coli K12 and affects the pathogenicity of Shigella flexneri and Vibrio cholera. Avian pathogenic E. coli (APEC) is an extra-intestinal pathogenic E. coli (ExPEC), causing acute and sudden death in poultry and leading to severe economic losses to the global poultry industry. How the functions of EnvZ correlate with APEC pathogenicity was still unknown. In this study, we successfully constructed the envZ mutant strain AE17ΔenvZ and the inactivation of envZ significantly reduced biofilms and altered red, dry, and rough (rdar) morphology. In addition, AE17ΔenvZ was significantly less resistant to acid, alkali, osmotic, and oxidative stress conditions. Deletion of envZ significantly enhanced sensitivity to specific pathogen-free (SPF) chicken serum and increased adhesion to chicken embryonic fibroblast DF-1 cells and elevated inflammatory cytokine IL-1β, IL6, and IL8 expression levels. Also, when compared with the WT strain, AE17ΔenvZ attenuated APEC pathogenicity in chickens. To explore the molecular mechanisms underpinning envZ in APEC17, we compared the WT and envZ-deletion strains using transcriptome analyses. RNA-Seq results identified 711 differentially expressed genes (DEGs) in the envZ mutant strain and DEGs were mainly enriched in outer membrane proteins, stress response systems, and TCSs. Quantitative real-time reverse transcription PCR (RT-qPCR) showed that EnvZ influenced the expression of biofilms and stress responses genes, including ompC, ompT, mlrA, basR, hdeA, hdeB, adiY, and uspB. We provided compelling evidence showing EnvZ contributed to APEC pathogenicity by regulating biofilms and stress response expression.
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Affiliation(s)
- Dandan Fu
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China,Anhui Province Engineering Laboratory for Animal Food Quality and Bio-Safety, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China
| | - Jianmei Wu
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China,Anhui Province Engineering Laboratory for Animal Food Quality and Bio-Safety, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China
| | - Xiaoyan Wu
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China,Anhui Province Engineering Laboratory for Animal Food Quality and Bio-Safety, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China
| | - Ying Shao
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China,Anhui Province Engineering Laboratory for Animal Food Quality and Bio-Safety, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China
| | - Xiangjun Song
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China,Anhui Province Engineering Laboratory for Animal Food Quality and Bio-Safety, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China
| | - Jian Tu
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China,Anhui Province Engineering Laboratory for Animal Food Quality and Bio-Safety, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China
| | - Kezong Qi
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China,Anhui Province Engineering Laboratory for Animal Food Quality and Bio-Safety, College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, PR China,Corresponding author:
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16
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Christiaens AS, Van Steenkiste M, Rummens K, Smets I. Amyloid adhesin production in activated sludge is enhanced in lab-scale sequencing batch reactors: Feeding regime impacts microbial community and amyloid distribution. WATER RESEARCH X 2022; 17:100162. [PMID: 36479239 PMCID: PMC9720597 DOI: 10.1016/j.wroa.2022.100162] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Amyloid adhesins are β-sheet-rich extracellular proteins thought to contribute to bioflocculation. They are present in activated sludge to varying extent. However, it remains unclear which operational conditions promote their production. To this end, the abundance and distribution of amyloids and their potential producers were monitored in two lab-scale reactors operated in sequencing batch mode with an unaerated and aerated reaction phase. Various feeding regimes ranging from feast-famine to nearly continuous feeding were applied. Thioflavin T staining revealed more amyloids in the lab-scale reactors during all operational stages compared to the full-scale industrial and municipal inocula. Furthermore, the feeding regime impacted the distribution of produced amyloids from dense clusters during feast-famine conditions towards a dispersed distribution during nearly continuous feeding. This dispersed presence did not negatively impact the bioflocculation (towards average floc size and shear sensitivity). 16S rRNA sequencing detected several known EPS and amyloid producers. More continuous and, hence, partially aerobic feeding promoted the relative abundance of denitrifiers. Sequential Thioflavin T staining and fluorescence in situ hybridization identified Zoogloea and Ca. Competibacter as potential amyloid producers under the applied conditions. This experiment confirms that amyloid producers need to be triggered for production and that the feeding regime impacts the microbial community composition, which in turn influences the amyloid production and distribution.
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17
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León-Montes N, Nava-Galeana J, Rodríguez-Valverde D, Soria-Bustos J, Rosales-Reyes R, Rivera-Gutiérrez S, Hirakawa H, Ares MA, Bustamante VH, De la Cruz MA. The Two-Component System CpxRA Represses Salmonella Pathogenicity Island 2 by Directly Acting on the ssrAB Regulatory Operon. Microbiol Spectr 2022; 10:e0271022. [PMID: 36073960 PMCID: PMC9603713 DOI: 10.1128/spectrum.02710-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 08/15/2022] [Indexed: 01/04/2023] Open
Abstract
The acquisition of Salmonella pathogenicity island 2 (SPI-2) conferred on Salmonella the ability to survive and replicate within host cells. The ssrAB bicistronic operon, located in SPI-2, encodes the SsrAB two-component system (TCS), which is the central positive regulator that induces the expression of SPI-2 genes as well as other genes located outside this island. On the other hand, CpxRA is a two-component system that regulates expression of virulence genes in many bacteria in response to different stimuli that perturb the cell envelope. We previously reported that the CpxRA system represses the expression of SPI-1 and SPI-2 genes under SPI-1-inducing conditions by decreasing the stability of the SPI-1 regulator HilD. Here, we show that under SPI-2-inducing conditions, which mimic the intracellular environment, CpxRA represses the expression of SPI-2 genes by the direct action of phosphorylated CpxR (CpxR-P) on the ssrAB regulatory operon. CpxR-P recognized two sites located proximal and distal from the promoter located upstream of ssrA. Consistently, we found that CpxRA reduces the replication of Salmonella enterica serovar Typhimurium inside murine macrophages. Therefore, our results reveal CpxRA as an additional regulator involved in the intracellular lifestyle of Salmonella, which in turn adds a new layer to the intricate regulatory network controlling the expression of Salmonella virulence genes. IMPORTANCE SPI-2 encodes a type III secretion system (T3SS) that is a hallmark for the species Salmonella enterica, which is essential for the survival and replication within macrophages. Expression of SPI-2 genes is positively controlled by the two-component system SsrAB. Here, we determined a regulatory mechanism involved in controlling the overgrowth of Salmonella inside macrophages. In this mechanism, CpxRA, a two-component system that is activated by extracytoplasmic stress, directly represses expression of the ssrAB regulatory operon; as a consequence, expression of SsrAB target genes is decreased. Our findings reveal a novel mechanism involved in the intracellular lifestyle of Salmonella, which is expected to sense perturbations in the bacterial envelope that Salmonella faces inside host cells, as the synthesis of the T3SS-2 itself.
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Affiliation(s)
- Nancy León-Montes
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Jessica Nava-Galeana
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Diana Rodríguez-Valverde
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Jorge Soria-Bustos
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Roberto Rosales-Reyes
- Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Sandra Rivera-Gutiérrez
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Hidetada Hirakawa
- Department of Bacteriology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Miguel A. Ares
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico
| | - Víctor H. Bustamante
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Miguel A. De la Cruz
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico
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18
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Horne SM, Prüß BM. A Wash of Ethyl Acetoacetate Reduces Externally added Salmonella enterica on Tomatoes. Antibiotics (Basel) 2022; 11:antibiotics11081134. [PMID: 36010003 PMCID: PMC9405465 DOI: 10.3390/antibiotics11081134] [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: 07/26/2022] [Revised: 08/13/2022] [Accepted: 08/18/2022] [Indexed: 12/04/2022] Open
Abstract
The continuously high numbers of food-borne disease outbreaks document that current intervention techniques are not yet satisfactory. This study describes a novel wash for tomatoes that can be used as part of the food processing chain and is designed to prevent contamination with serovars of Salmonella enterica. The wash contains ethyl acetoacetate (EAA) at a concentration of 8% in H2O. This wash reduced live bacterial counts (on Salmonella Shigella agar) of externally added S. Newport MDD14 by 2.3 log, counts of S. Typhimurium ATCC19585 by 1.5 log, and counts of S. Typhimurium FSL R6-0020 by 3.4 log. The naturally occurring background flora of the tomatoes was determined on plate count agar. The log reduction by EAA was 2.1. To mimic organic matter in the wash, we added 1% tomato homogenate to the 8% EAA solution. Prior to using the wash, the tomato homogenate was incubated with the EAA for 2 h. In the presence of the tomato homogenate, the log reductions were 2.4 log for S. Newport MDD14 and 3 log for S. Typhimurium FSL R6-0020. It seems like tomato homogenate did not reduce the efficacy of the EAA wash in the two S. enterica serovars tested. We propose the use of EAA as a wash for tomatoes to reduce bacterial counts of S. enterica well as naturally occurring background flora.
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19
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Ballén V, Cepas V, Ratia C, Gabasa Y, Soto SM. Clinical Escherichia coli: From Biofilm Formation to New Antibiofilm Strategies. Microorganisms 2022; 10:microorganisms10061103. [PMID: 35744621 PMCID: PMC9229135 DOI: 10.3390/microorganisms10061103] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 02/05/2023] Open
Abstract
Escherichia coli is one of the species most frequently involved in biofilm-related diseases, being especially important in urinary tract infections, causing relapses or chronic infections. Compared to their planktonic analogues, biofilms confer to the bacteria the capacity to be up to 1000-fold more resistant to antibiotics and to evade the action of the host’s immune system. For this reason, biofilm-related infections are very difficult to treat. To develop new strategies against biofilms, it is important to know the mechanisms involved in their formation. In this review, the different steps of biofilm formation in E. coli, the mechanisms of tolerance to antimicrobials and new compounds and strategies to combat biofilms are discussed.
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Affiliation(s)
- Victoria Ballén
- ISGlobal, Hospital Clínic, Universitat de Barcelona, 08036 Barcelona, Spain; (V.B.); (V.C.); (C.R.); (Y.G.)
| | - Virginio Cepas
- ISGlobal, Hospital Clínic, Universitat de Barcelona, 08036 Barcelona, Spain; (V.B.); (V.C.); (C.R.); (Y.G.)
| | - Carlos Ratia
- ISGlobal, Hospital Clínic, Universitat de Barcelona, 08036 Barcelona, Spain; (V.B.); (V.C.); (C.R.); (Y.G.)
| | - Yaiza Gabasa
- ISGlobal, Hospital Clínic, Universitat de Barcelona, 08036 Barcelona, Spain; (V.B.); (V.C.); (C.R.); (Y.G.)
| | - Sara M. Soto
- ISGlobal, Hospital Clínic, Universitat de Barcelona, 08036 Barcelona, Spain; (V.B.); (V.C.); (C.R.); (Y.G.)
- CIBER Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence:
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20
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Fu D, Wu J, Gu Y, Li Q, Shao Y, Feng H, Song X, Tu J, Qi K. The response regulator OmpR contributes to the pathogenicity of avian pathogenic Escherichia coli. Poult Sci 2022; 101:101757. [PMID: 35240350 PMCID: PMC8892008 DOI: 10.1016/j.psj.2022.101757] [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: 11/30/2021] [Revised: 01/23/2022] [Accepted: 01/25/2022] [Indexed: 11/03/2022] Open
Abstract
Avian colibacillosis is a serious systemic infectious disease in poultry and caused by avian pathogenic Escherichia coli (APEC). Previous studies have shown that 2-component systems (TCSs) are involved in the pathogenicity of APEC. OmpR, a response regulator of OmpR/EnvZ TCS, plays an important role in E. coli K-12. However, whether OmpR correlates with APEC pathogenesis has not been established. In this study, we constructed an ompR gene mutant and complement strains by using the CRISPR-Cas9 system and found that the inactivation of the ompR gene attenuated bacterial motility, biofilm formation, and the production of curli. The resistance to environmental stress, serum sensitivity, adhesion, and invasion of DF-1 cells, and pathogenicity in chicks were all significantly reduced in the mutant strain AE17ΔompR. These phenotypes were restored in the complement strain AE17C-ompR. The qRT-PCR results showed that OmpR influences the expression of genes associated with the flagellum, biofilm formation, and virulence. These findings indicate that the regulator OmpR contributes to APEC pathogenicity by affecting the expression and function of virulence factors.
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21
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Buck LD, Paladino MM, Nagashima K, Brezel ER, Holtzman JS, Urso SJ, Ryno LM. Temperature-Dependent Influence of FliA Overexpression on PHL628 E. coli Biofilm Growth and Composition. Front Cell Infect Microbiol 2022; 11:775270. [PMID: 34976858 PMCID: PMC8718923 DOI: 10.3389/fcimb.2021.775270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/29/2021] [Indexed: 11/13/2022] Open
Abstract
Biofilm growth and survival pose a problem in both medical and industrial fields. Bacteria in biofilms are more tolerant to antibiotic treatment due to the inability of antibiotics to permeate to the bottom layers of cells in a biofilm and the creation of altered microenvironments of bacteria deep within the biofilm. Despite the abundance of information we have about E. coli biofilm growth and maturation, we are still learning how manipulating different signaling pathways influences the formation and fitness of biofilm. Understanding the impact of signaling pathways on biofilm formation may narrow the search for novel small molecule inhibitors or activators that affect biofilm production and stability. Here, we study the influence of the minor sigma transcription factor FliA (RpoF, sigma-28), which controls late-stage flagellar assembly and chemotaxis, on biofilm production and composition at various temperatures in the E. coli strain PHL628, which abundantly produces the extracellular structural protein curli. We examined FliA's influence on external cellular structures like curli and flagella and the biomolecular composition of the biofilm's extracellular polymeric substance (EPS) using biochemical assays, immunoblotting, and confocal laser scanning microscopy (CLSM). At 37°C, FliA overexpression results in the dramatic growth of biofilm in polystyrene plates and more modest yet significant biofilm growth on silica slides. We observed no significant differences in curli concentration and carbohydrate concentration in the EPS with FliA overexpression. Still, we did see significant changes in the abundance of EPS protein using CLSM at higher growth temperatures. We also noticed increased flagellin concentration, a major structural protein in flagella, occurred with FliA overexpression, specifically in planktonic cultures. These experiments have aided in narrowing our focus to FliA's role in changing the protein composition of the EPS, which we will examine in future endeavors.
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Affiliation(s)
- Luke D Buck
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH, United States
| | - Maddison M Paladino
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH, United States
| | - Kyogo Nagashima
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH, United States
| | - Emma R Brezel
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH, United States
| | - Joshua S Holtzman
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH, United States
| | - Sarel J Urso
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH, United States
| | - Lisa M Ryno
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH, United States
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22
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Quintieri L, Caputo L, Brasca M, Fanelli F. Recent Advances in the Mechanisms and Regulation of QS in Dairy Spoilage by Pseudomonas spp. Foods 2021; 10:3088. [PMID: 34945641 PMCID: PMC8701193 DOI: 10.3390/foods10123088] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 11/28/2021] [Accepted: 12/08/2021] [Indexed: 11/16/2022] Open
Abstract
Food spoilage is a serious issue dramatically impacting the worldwide need to counteract food insecurity. Despite the very expensive application of low temperatures, the proper conservation of fresh dairy products is continuously threatened at different stages of production and commercialization by psychrotrophic populations mainly belonging to the Pseudomonas genus. These bacteria cause discolouration, loss of structure, and off-flavours, with fatal implications on the quality and shelf-life of products. While the effects of pseudomonad decay have been widely reported, the mechanisms responsible for the activation and regulation of spoilage pathways are still poorly explored. Recently, molecule signals and regulators involved in quorum sensing (QS), such as homoserine lactones, the luxR/luxI system, hdtS, and psoR, have been detected in spoiled products and bacterial spoiler species; this evidence suggests the role of bacterial cross talk in dairy spoilage and paves the way towards the search for novel preservation strategies based on QS inhibition. The aim of this review was to investigate the advancements achieved by the application of omic approaches in deciphering the molecular mechanisms controlled by QS systems in pseudomonads, by focusing on the regulators and metabolic pathways responsible for spoilage of fresh dairy products. In addition, due the ability of pseudomonads to quickly spread in the environment as biofilm communities, which may also include pathogenic and multidrug-resistant (MDR) species, the risk derived from the gaps in clearly defined and regulated sanitization actions is underlined.
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Affiliation(s)
- Laura Quintieri
- Institute of Sciences of Food Production, National Research Council of Italy, 70126 Bari, Italy; (L.C.); (F.F.)
| | - Leonardo Caputo
- Institute of Sciences of Food Production, National Research Council of Italy, 70126 Bari, Italy; (L.C.); (F.F.)
| | - Milena Brasca
- Institute of Sciences of Food Production, National Research Council of Italy, 20133 Milan, Italy;
| | - Francesca Fanelli
- Institute of Sciences of Food Production, National Research Council of Italy, 70126 Bari, Italy; (L.C.); (F.F.)
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23
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Chong P, Erable B, Bergel A. How bacteria use electric fields to reach surfaces. Biofilm 2021; 3:100048. [PMID: 33997766 PMCID: PMC8090995 DOI: 10.1016/j.bioflm.2021.100048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 03/15/2021] [Accepted: 03/28/2021] [Indexed: 11/15/2022] Open
Abstract
Electrotaxis is the property of cells to sense electric fields and use them to orient their displacement. This property has been widely investigated with eukaryotic cells but it remains unclear whether or not bacterial cells can sense an electric field. Here, a specific experimental set-up was designed to form microbial electroactive biofilms while differentiating the effect of the electric field from that of the polarised electrode surface. Application of an electric field during exposure of the electrodes to the inoculum was shown to be required for an electroactive biofilm to form afterwards. Similar biofilms were formed in both directions of the electric field. This result is attributed to the capacity of the cells to detect the K+ and Na+ ion gradients that the electric field creates at the electrode surface. This microbial property should now be considered as a key factor in the formation of electroactive biofilms and possible implications in the biomedical domain are discussed.
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Affiliation(s)
- Poehere Chong
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INP, UPS, Toulouse, France
| | - Benjamin Erable
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INP, UPS, Toulouse, France
| | - Alain Bergel
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INP, UPS, Toulouse, France
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24
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Tan X, Qiao J, Li H, Huang D, Hu X, Wang X. Global metabolic regulation in Vibrio parahaemolyticus under polymyxin B stimulation. Microb Pathog 2021; 161:105260. [PMID: 34688850 DOI: 10.1016/j.micpath.2021.105260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/25/2021] [Accepted: 10/13/2021] [Indexed: 11/17/2022]
Abstract
Vibrio parahaemolyticus is responsible for infection diseases of people who consume the contaminated seafood, but its metabolic regulation profile in response to colistin, the last treatment option for multidrug-resistant Gram-negative bacteria, remains unclear. In this study, the metabolic regulation profile of V. parahaemolyticus ATCC33846 under polymyxin B stimulation has been investigated. V. parahaemolyticus exposed to polymyxin B resulted in 4597 differentially transcribed genes, including 673 significantly up-regulated genes and 569 significantly down-regulated genes. In V. parahaemolyticus under polymyxin B stimulation, the cellular antioxidant systems to prevent bacteria from oxidant stress was activated, the synthesis of some nonessential macromolecules was reduced, and the assembly and modification of lipopolysaccharide and peptidoglycan to resist the attack from other antibiotics were promoted. These findings provide new insights into polymyxin B-related stress response in V. parahaemolyticus which should be useful for developing novel drugs for infection.
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Affiliation(s)
- Xin Tan
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Jun Qiao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Hedan Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Danyang Huang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Xiaoqing Hu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.
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25
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Aditya V, Kotian A, Saikrishnan S, Rohit A, Mithoor D, Karunasagar I, Deekshit VK. Effect of ciprofloxacin and in vitro gut conditions on biofilm of Escherichia coli isolated from clinical and environmental sources. J Appl Microbiol 2021; 132:964-977. [PMID: 34374176 DOI: 10.1111/jam.15249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/20/2021] [Accepted: 08/02/2021] [Indexed: 01/04/2023]
Abstract
AIM This study aimed at characterizing the biofilm-forming ability of drug-resistant and sensitive Escherichia coli under in vitro gut conditions and in the presence of ciprofloxacin. METHODS AND RESULTS 153 E. coli isolates comprising 80 from clinical and 73 from environment source were studied for their ability to form biofilm under control and in vitro simulated gut conditions. The integrity of preformed biofilm on exposure to ciprofloxacin was assessed. Expression of biofilm-associated genes was analysed using qPCR. A high degree of resistance was observed in clinical isolates with a concomitant prevalence of blaTEM . Bile, pH and low temperature enabled the E. coli biofilm to resist the effect of ciprofloxacin. Clinical isolates of E. coli formed strong biofilms in in vitro gut conditions following exposure to high concentration of ciprofloxacin. The expression of biofilm genes varied between different gut conditions viz., presence of bile, pH and low temperature, included in this study. CONCLUSIONS This study demonstrates the importance of papC and csgA for maintaining the biofilm integrity upon antibiotic exposure. Escherichia coli form biofilm as a survival strategy to adapt to the conditions in their environment irrespective of their drug resistance status. SIGNIFICANCE AND IMPACT OF THE STUDY The study provides an understanding of the effect of different parameters of the gut conditions during infection and the effect of antibiotic on survival and biofilm-forming ability of clinical and environmental E. coli isolates. It further suggests that bacteria resort to biofilm formation as one of the mechanisms to adjust to alterations in gut conditions and once the biofilm is formed, it requires high concentration of ciprofloxacin to eradicate it.
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Affiliation(s)
- Vankadari Aditya
- Nitte (Deemed to be University), Division of Infectious Diseases, Nitte University Center for Science Education and Research, Mangaluru, India
| | - Akshatha Kotian
- Nitte (Deemed to be University), Division of Infectious Diseases, Nitte University Center for Science Education and Research, Mangaluru, India
| | - Sreya Saikrishnan
- Nitte (Deemed to be University), Division of Infectious Diseases, Nitte University Center for Science Education and Research, Mangaluru, India
| | - Anusha Rohit
- Department of Microbiology, Madras Medical Mission, Chennai, India
| | - Divyashree Mithoor
- Nitte (Deemed to be University), Division of Infectious Diseases, Nitte University Center for Science Education and Research, Mangaluru, India
| | - Indrani Karunasagar
- Nitte (Deemed to be University), Division of Infectious Diseases, Nitte University Center for Science Education and Research, Mangaluru, India
| | - Vijaya Kumar Deekshit
- Nitte (Deemed to be University), Division of Infectious Diseases, Nitte University Center for Science Education and Research, Mangaluru, India
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26
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Vasicek EM, O'Neal L, Parsek MR, Fitch J, White P, Gunn JS. L-Arabinose Transport and Metabolism in Salmonella Influences Biofilm Formation. Front Cell Infect Microbiol 2021; 11:698146. [PMID: 34368016 PMCID: PMC8341724 DOI: 10.3389/fcimb.2021.698146] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/21/2021] [Indexed: 11/28/2022] Open
Abstract
L-arabinose inducible promoters are commonly used in gene expression analysis. However, nutrient source and availability also play a role in biofilm formation; therefore, L-arabinose metabolism could impact biofilm development. In this study we examined the impact of L-arabinose on Salmonella enterica serovar Typhimurium (S. Typhimurium) biofilm formation. Using mutants impaired for the transport and metabolism of L-arabinose, we showed that L-arabinose metabolism negatively impacts S. Typhimurium biofilm formation in vitro. When L-arabinose metabolism is abrogated, biofilm formation returned to baseline levels. However, without the ability to import extracellular L-arabinose, biofilm formation significantly increased. Using RNA-Seq we identified several gene families involved in these different phenotypes including curli expression, amino acid synthesis, and L-arabinose metabolism. Several individual candidate genes were tested for their involvement in the L-arabinose-mediated biofilm phenotypes, but most played no significant role. Interestingly, in the presence of L-arabinose the diguanylate cyclase gene adrA was downregulated in wild type S. Typhimurium. Meanwhile cyaA, encoding an adenylate cyclase, was downregulated in an L-arabinose transport mutant. Using an IPTG-inducible plasmid to deplete c-di-GMP via vieA expression, we were able to abolish the increased biofilm phenotype seen in the transport mutant. However, the mechanism by which the L-arabinose import mutant forms significantly larger biofilms remains to be determined. Regardless, these data suggest that L-arabinose metabolism influences intracellular c-di-GMP levels and therefore biofilm formation. These findings are important when considering the use of an L-arabinose inducible promoter in biofilm conditions.
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Affiliation(s)
- Erin M Vasicek
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, OH, United States.,Infectious Diseases Institute, The Ohio State University, Columbus, OH, United States.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, United States
| | - Lindsey O'Neal
- Department of Microbiology, University of Washington, Seattle, WA, United States
| | - Matthew R Parsek
- Department of Microbiology, University of Washington, Seattle, WA, United States
| | - James Fitch
- The Institute for Genomic Medicine, The Research Institute at Nationwide Children's Hospital, Columbus, OH, United States
| | - Peter White
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, United States.,The Institute for Genomic Medicine, The Research Institute at Nationwide Children's Hospital, Columbus, OH, United States
| | - John S Gunn
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, OH, United States.,Infectious Diseases Institute, The Ohio State University, Columbus, OH, United States.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, United States
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27
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Pietrzyk-Brzezinska AJ, Cociurovscaia A. Structures of the TetR-like transcription regulator RcdA alone and in complexes with ligands. Proteins 2021; 90:33-44. [PMID: 34288132 DOI: 10.1002/prot.26183] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 05/20/2021] [Accepted: 07/11/2021] [Indexed: 01/25/2023]
Abstract
RcdA is a helix-turn-helix (HTH) transcriptional regulator belonging to the TetR family. The protein regulates the transcription of curlin subunit gene D, the master regulator of biofilm formation. Moreover, it was predicted that it might be involved in the regulation of up to 27 different genes. However, an effector of RcdA and the environmental conditions which trigger RcdA action remain unknown. Herein, we report the first crystal structures of RcdA in complexes with ligands, trimethylamine N-oxide (TMAO) and tris(hydroxymethyl)aminomethane (Tris), which might serve as RcdA effectors. Based on these structures, the ligand-binding pocket of RcdA was characterized in detail. The conservation of the amino acid residues forming the ligand-binding cavity was analyzed and the comprehensive search for RcdA structural homologs was performed. This analysis indicated that RcdA is structurally similar to multidrug-binding TetR family members, however, its ligand-binding cavity differs significantly from the pockets of its structural homologs. The interaction of RcdA with TMAO and Tris indicates that the protein might be involved in alkaline stress response.
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Affiliation(s)
- Agnieszka J Pietrzyk-Brzezinska
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Lodz, Poland
| | - Anna Cociurovscaia
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Lodz, Poland
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28
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Bischofberger AM, Pfrunder Cardozo KR, Baumgartner M, Hall AR. Evolution of honey resistance in experimental populations of bacteria depends on the type of honey and has no major side effects for antibiotic susceptibility. Evol Appl 2021; 14:1314-1327. [PMID: 34025770 PMCID: PMC8127710 DOI: 10.1111/eva.13200] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/24/2020] [Accepted: 01/25/2021] [Indexed: 01/01/2023] Open
Abstract
With rising antibiotic resistance, alternative treatments for communicable diseases are increasingly relevant. One possible alternative for some types of infections is honey, used in wound care since before 2000 BCE and more recently in licensed, medical-grade products. However, it is unclear whether medical application of honey results in the evolution of bacterial honey resistance and whether this has collateral effects on other bacterial traits such as antibiotic resistance. Here, we used single-step screening assays and serial transfer at increasing concentrations to isolate honey-resistant mutants of Escherichia coli. We only detected bacteria with consistently increased resistance to the honey they evolved in for two of the four tested honey products, and the observed increases were small (maximum twofold increase in IC90). Genomic sequencing and experiments with single-gene knockouts showed a key mechanism by which bacteria increased their honey resistance was by mutating genes involved in detoxifying methylglyoxal, which contributes to the antibacterial activity of Leptospermum honeys. Crucially, we found no evidence that honey adaptation conferred cross-resistance or collateral sensitivity against nine antibiotics from six different classes. These results reveal constraints on bacterial adaptation to different types of honey, improving our ability to predict downstream consequences of wider honey application in medicine.
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Affiliation(s)
| | | | | | - Alex R. Hall
- Institute of Integrative BiologyETH ZurichZurichSwitzerland
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29
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Ko D, Choi SH. Comparative genomics reveals an SNP potentially leading to phenotypic diversity of Salmonella enterica serovar Enteritidis. Microb Genom 2021; 7:000572. [PMID: 33952386 PMCID: PMC8209725 DOI: 10.1099/mgen.0.000572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/29/2021] [Indexed: 12/25/2022] Open
Abstract
An SNP is a spontaneous genetic change having a potential to modify the functions of the original genes and to lead to phenotypic diversity of bacteria in nature. In this study, a phylogenetic analysis of Salmonella enterica serovar Enteritidis, a major food-borne pathogen, showed that eight strains of S. Enteritidis isolated in South Korea, including FORC_075 and FORC_078, have almost identical genome sequences. Interestingly, however, the abilities of FORC_075 to form biofilms and red, dry and rough (RDAR) colonies were significantly impaired, resulting in phenotypic differences among the eight strains. Comparative genomic analyses revealed that one of the non-synonymous SNPs unique to FORC_075 has occurred in envZ, which encodes a sensor kinase of the EnvZ/OmpR two-component system. The SNP in envZ leads to an amino acid change from Pro248 (CCG) in other strains including FORC_078 to Leu248 (CTG) in FORC_075. Allelic exchange of envZ between FORC_075 and FORC_078 identified that the SNP in envZ is responsible for the impaired biofilm- and RDAR colony-forming abilities of S. Enteritidis. Biochemical analyses demonstrated that the SNP in envZ significantly increases the phosphorylated status of OmpR in S. Enteritidis and alters the expression of the OmpR regulon. Phenotypic analyses further identified that the SNP in envZ decreases motility of S. Enteritidis but increases its adhesion and invasion to both human epithelial cells and murine macrophage cells. In addition to an enhancement of infectivity to the host cells, survival under acid stress was also elevated by the SNP in envZ. Together, these results suggest that the natural occurrence of the SNP in envZ could contribute to phenotypic diversity of S. Enteritidis, possibly improving its fitness and pathogenesis.
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Affiliation(s)
- Duhyun Ko
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology and Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea
| | - Sang Ho Choi
- National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology and Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea
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30
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Khambhati K, Patel J, Saxena V, A P, Jain N. Gene Regulation of Biofilm-Associated Functional Amyloids. Pathogens 2021; 10:490. [PMID: 33921583 PMCID: PMC8072697 DOI: 10.3390/pathogens10040490] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/15/2021] [Accepted: 04/15/2021] [Indexed: 01/01/2023] Open
Abstract
Biofilms are bacterial communities encased in a rigid yet dynamic extracellular matrix. The sociobiology of bacterial communities within a biofilm is astonishing, with environmental factors playing a crucial role in determining the switch from planktonic to a sessile form of life. The mechanism of biofilm biogenesis is an intriguingly complex phenomenon governed by the tight regulation of expression of various biofilm-matrix components. One of the major constituents of the biofilm matrix is proteinaceous polymers called amyloids. Since the discovery, the significance of biofilm-associated amyloids in adhesion, aggregation, protection, and infection development has been much appreciated. The amyloid expression and assembly is regulated spatio-temporarily within the bacterial cells to perform a diverse function. This review provides a comprehensive account of the genetic regulation associated with the expression of amyloids in bacteria. The stringent control ensures optimal utilization of amyloid scaffold during biofilm biogenesis. We conclude the review by summarizing environmental factors influencing the expression and regulation of amyloids.
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Affiliation(s)
- Khushal Khambhati
- Department of Bioscience and Bioengineering, Indian Institute of Technology Jodhpur NH 65, Nagaur Road, Karwar, Rajasthan 342037, India
| | - Jaykumar Patel
- Department of Bioscience and Bioengineering, Indian Institute of Technology Jodhpur NH 65, Nagaur Road, Karwar, Rajasthan 342037, India
| | - Vijaylaxmi Saxena
- Department of Bioscience and Bioengineering, Indian Institute of Technology Jodhpur NH 65, Nagaur Road, Karwar, Rajasthan 342037, India
| | - Parvathy A
- Department of Bioscience and Bioengineering, Indian Institute of Technology Jodhpur NH 65, Nagaur Road, Karwar, Rajasthan 342037, India
| | - Neha Jain
- Department of Bioscience and Bioengineering, Indian Institute of Technology Jodhpur NH 65, Nagaur Road, Karwar, Rajasthan 342037, India
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31
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Jaswal K, Shrivastava M, Chaba R. Revisiting long-chain fatty acid metabolism in Escherichia coli: integration with stress responses. Curr Genet 2021; 67:573-582. [PMID: 33740112 DOI: 10.1007/s00294-021-01178-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 12/29/2022]
Abstract
Long-chain fatty acids (LCFAs) are a tremendous source of metabolic energy, an essential component of membranes, and important effector molecules that regulate a myriad of cellular processes. As an energy-rich nutrient source, the role of LCFAs in promoting bacterial survival and infectivity is well appreciated. LCFA degradation generates a large number of reduced cofactors that may confer redox stress; therefore, it is imperative to understand how bacteria deal with this paradoxical situation. Although the LCFA utilization pathway has been studied in great detail, especially in Escherichia coli, where the earliest studies date back to the 1960s, the interconnection of LCFA degradation with bacterial stress responses remained largely unexplored. Recent work in E. coli shows that LCFA degradation induces oxidative stress and also impedes oxidative protein folding. Importantly, both issues arise due to the insufficiency of ubiquinone, a lipid-soluble electron carrier in the electron transport chain. However, to maintain redox homeostasis, bacteria induce sophisticated cellular responses. Here, we review these findings in light of our current knowledge of the LCFA metabolic pathway, metabolism-induced oxidative stress, the process of oxidative protein folding, and stress combat mechanisms. We discuss probable mechanisms for the activation of defense players during LCFA metabolism and the likely feedback imparted by them. We suggest that besides defending against intrinsic stresses, LCFA-mediated upregulation of stress response pathways primes bacteria to adapt to harsh external environments. Collectively, the interplay between LCFA metabolism and stress responses is likely an important factor that underlies the success of LCFA-utilizing bacteria in the host.
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Affiliation(s)
- Kanchan Jaswal
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India
| | - Megha Shrivastava
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India
| | - Rachna Chaba
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, SAS Nagar, Punjab, India.
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Ageorges V, Monteiro R, Leroy S, Burgess CM, Pizza M, Chaucheyras-Durand F, Desvaux M. Molecular determinants of surface colonisation in diarrhoeagenic Escherichia coli (DEC): from bacterial adhesion to biofilm formation. FEMS Microbiol Rev 2021; 44:314-350. [PMID: 32239203 DOI: 10.1093/femsre/fuaa008] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/31/2020] [Indexed: 12/11/2022] Open
Abstract
Escherichia coli is primarily known as a commensal colonising the gastrointestinal tract of infants very early in life but some strains being responsible for diarrhoea, which can be especially severe in young children. Intestinal pathogenic E. coli include six pathotypes of diarrhoeagenic E. coli (DEC), namely, the (i) enterotoxigenic E. coli, (ii) enteroaggregative E. coli, (iii) enteropathogenic E. coli, (iv) enterohemorragic E. coli, (v) enteroinvasive E. coli and (vi) diffusely adherent E. coli. Prior to human infection, DEC can be found in natural environments, animal reservoirs, food processing environments and contaminated food matrices. From an ecophysiological point of view, DEC thus deal with very different biotopes and biocoenoses all along the food chain. In this context, this review focuses on the wide range of surface molecular determinants acting as surface colonisation factors (SCFs) in DEC. In the first instance, SCFs can be broadly discriminated into (i) extracellular polysaccharides, (ii) extracellular DNA and (iii) surface proteins. Surface proteins constitute the most diverse group of SCFs broadly discriminated into (i) monomeric SCFs, such as autotransporter (AT) adhesins, inverted ATs, heat-resistant agglutinins or some moonlighting proteins, (ii) oligomeric SCFs, namely, the trimeric ATs and (iii) supramolecular SCFs, including flagella and numerous pili, e.g. the injectisome, type 4 pili, curli chaperone-usher pili or conjugative pili. This review also details the gene regulatory network of these numerous SCFs at the various stages as it occurs from pre-transcriptional to post-translocational levels, which remains to be fully elucidated in many cases.
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Affiliation(s)
- Valentin Ageorges
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | - Ricardo Monteiro
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France.,GSK, Via Fiorentina 1, 53100 Siena, Italy
| | - Sabine Leroy
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | - Catherine M Burgess
- Food Safety Department, Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland
| | | | - Frédérique Chaucheyras-Durand
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France.,Lallemand Animal Nutrition SAS, F-31702 Blagnac Cedex, France
| | - Mickaël Desvaux
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
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Pellicle formation by Escherichia coli K-12: Role of adhesins and motility. J Biosci Bioeng 2021; 131:381-389. [PMID: 33495047 DOI: 10.1016/j.jbiosc.2020.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 11/24/2020] [Accepted: 12/05/2020] [Indexed: 01/01/2023]
Abstract
Initial work to generate physically robust biofilms for biocatalytic applications revealed that Escherichia coli K-12 can form a floating biofilm at the air-liquid interface, commonly referred to as a pellicle. Unlike other species where pellicle formation is well-characterised, such as Bacillus subtilis, there are few reports of E. coli K-12 pellicles in the literature. In order to study pellicle formation, a growth model was developed and pellicle formation was monitored over time. Mechanical forces, both motility and shaking, were shown to have effects on pellicle formation and development. The role and regulation of curli, an amyloid protein adhesin critical in E. coli K-12 biofilm formation, was studied by using promoter-green fluorescent protein reporters; flow cytometry and confocal laser scanning microscopy were used to monitor curli expression over time and in different locations. Curli were found to be not only crucial for pellicle formation, but also heterogeneously expressed within the pellicle. The components of the extracellular polymeric substances (EPS) in pellicles were analysed by confocal microscopy using lectins, revealing distinct pellicle morphology on the air-facing and medium-facing sides, and spatially- and temporally-regulated generation of the EPS components poly-N-acetyl glucosamine and colanic acid. We discuss the difference between pellicles formed by E. coli K-12, pathogenic E. coli strains and other species, and the relationship between E. coli K-12 pellicles and solid surface-attached biofilms.
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Moon DJ, Deva AK. Adverse Events Associated with Breast Implants: The Role of Bacterial Infection and Biofilm. Clin Plast Surg 2021; 48:101-108. [PMID: 33220897 DOI: 10.1016/j.cps.2020.09.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- David J Moon
- Department of Plastic and Reconstructive Surgery, Macquarie University, Suite 301, Level 3, 2 Technology place, New South Wales 2109, Australia
| | - Anand K Deva
- Department of Plastic and Reconstructive Surgery, Macquarie University, Suite 301, Level 3, 2 Technology place, New South Wales 2109, Australia; Integrated Specialist Healthcare Education and Research Foundation, Miranda, New South Wales, 2228, Australia.
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Wang L, Wu Y, Cai P, Huang Q. The attachment process and physiological properties of Escherichia coli O157:H7 on quartz. BMC Microbiol 2020; 20:355. [PMID: 33213384 PMCID: PMC7677791 DOI: 10.1186/s12866-020-02043-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 11/09/2020] [Indexed: 01/24/2023] Open
Abstract
Background Manure application and sewage irrigation release many intestinal pathogens into the soil. After being introduced into the soil matrix, pathogens are commonly found to attach to soil minerals. Although the survival of mineral-associated Escherichia coli O157:H7 has been studied, a comprehensive understanding of the attachment process and physiological properties after attachment is still lacking. Results In this study, planktonic and attached Escherichia coli O157:H7 cells on quartz were investigated using RNA sequencing (RNA-seq) and the isobaric tagging for relative and absolute quantitation (iTRAQ) proteomic method. Based on the transcriptomic and proteomic analyses and gene knockouts, functional two-component system pathways were required for efficient attachment; chemotaxis and the Rcs system were identified to play determinant roles in E. coli O157:H7 attachment on quartz. After attachment, the pyruvate catabolic pathway shifted from the tricarboxylic acid (TCA) cycle toward the fermentative route. The survival rate of attached E. coli O157:H7 increased more than 10-fold under penicillin and vancomycin stress and doubled under alkaline pH and ferric iron stress. Conclusions These results contribute to the understanding of the roles of chemotaxis and the Rcs system in the attachment process of pathogens and indicate that the attachment of pathogens to minerals significantly elevates their resistance to antibiotics and environmental stress, which may pose a potential threat to public health. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-020-02043-8.
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Affiliation(s)
- Liliang Wang
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yichao Wu
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Peng Cai
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Qiaoyun Huang
- State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
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Choudhary KS, Kleinmanns JA, Decker K, Sastry AV, Gao Y, Szubin R, Seif Y, Palsson BO. Elucidation of Regulatory Modes for Five Two-Component Systems in Escherichia coli Reveals Novel Relationships. mSystems 2020; 5:e00980-20. [PMID: 33172971 PMCID: PMC7657598 DOI: 10.1128/msystems.00980-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 10/20/2020] [Indexed: 11/27/2022] Open
Abstract
Escherichia coli uses two-component systems (TCSs) to respond to environmental signals. TCSs affect gene expression and are parts of E. coli's global transcriptional regulatory network (TRN). Here, we identified the regulons of five TCSs in E. coli MG1655: BaeSR and CpxAR, which were stimulated by ethanol stress; KdpDE and PhoRB, induced by limiting potassium and phosphate, respectively; and ZraSR, stimulated by zinc. We analyzed RNA-seq data using independent component analysis (ICA). ChIP-exo data were used to validate condition-specific target gene binding sites. Based on these data, we do the following: (i) identify the target genes for each TCS; (ii) show how the target genes are transcribed in response to stimulus; and (iii) reveal novel relationships between TCSs, which indicate noncognate inducers for various response regulators, such as BaeR to iron starvation, CpxR to phosphate limitation, and PhoB and ZraR to cell envelope stress. Our understanding of the TRN in E. coli is thus notably expanded.IMPORTANCE E. coli is a common commensal microbe found in the human gut microenvironment; however, some strains cause diseases like diarrhea, urinary tract infections, and meningitis. E. coli's two-component systems (TCSs) modulate target gene expression, especially related to virulence, pathogenesis, and antimicrobial peptides, in response to environmental stimuli. Thus, it is of utmost importance to understand the transcriptional regulation of TCSs to infer bacterial environmental adaptation and disease pathogenicity. Utilizing a combinatorial approach integrating RNA sequencing (RNA-seq), independent component analysis, chromatin immunoprecipitation coupled with exonuclease treatment (ChIP-exo), and data mining, we suggest five different modes of TCS transcriptional regulation. Our data further highlight noncognate inducers of TCSs, which emphasizes the cross-regulatory nature of TCSs in E. coli and suggests that TCSs may have a role beyond their cognate functionalities. In summary, these results can lead to an understanding of the metabolic capabilities of bacteria and correctly predict complex phenotype under diverse conditions, especially when further incorporated with genome-scale metabolic models.
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Affiliation(s)
- Kumari Sonal Choudhary
- Department of Bioengineering, University of California, San Diego, San Diego, California, USA
| | - Julia A Kleinmanns
- Department of Bioengineering, University of California, San Diego, San Diego, California, USA
| | - Katherine Decker
- Department of Bioengineering, University of California, San Diego, San Diego, California, USA
| | - Anand V Sastry
- Department of Bioengineering, University of California, San Diego, San Diego, California, USA
| | - Ye Gao
- Department of Bioengineering, University of California, San Diego, San Diego, California, USA
| | - Richard Szubin
- Department of Bioengineering, University of California, San Diego, San Diego, California, USA
| | - Yara Seif
- Department of Bioengineering, University of California, San Diego, San Diego, California, USA
| | - Bernhard O Palsson
- Department of Bioengineering, University of California, San Diego, San Diego, California, USA
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
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Kimkes TEP, Heinemann M. How bacteria recognise and respond to surface contact. FEMS Microbiol Rev 2020; 44:106-122. [PMID: 31769807 PMCID: PMC7053574 DOI: 10.1093/femsre/fuz029] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 11/23/2019] [Indexed: 12/27/2022] Open
Abstract
Bacterial biofilms can cause medical problems and issues in technical systems. While a large body of knowledge exists on the phenotypes of planktonic and of sessile cells in mature biofilms, our understanding of what happens when bacteria change from the planktonic to the sessile state is still very incomplete. Fundamental questions are unanswered: for instance, how do bacteria sense that they are in contact with a surface, and what are the very initial cellular responses to surface contact. Here, we review the current knowledge on the signals that bacteria could perceive once they attach to a surface, the signal transduction systems that could be involved in sensing the surface contact and the cellular responses that are triggered as a consequence to surface contact ultimately leading to biofilm formation. Finally, as the main obstacle in investigating the initial responses to surface contact has been the difficulty to experimentally study the dynamic response of single cells upon surface attachment, we also review recent experimental approaches that could be employed to study bacterial surface sensing, which ultimately could lead to an improved understanding of how biofilm formation could be prevented.
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Affiliation(s)
- Tom E P Kimkes
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Matthias Heinemann
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
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38
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Miller AL, Pasternak JA, Medeiros NJ, Nicastro LK, Tursi SA, Hansen EG, Krochak R, Sokaribo AS, MacKenzie KD, Palmer MB, Herman DJ, Watson NL, Zhang Y, Wilson HL, Wilson RP, White AP, Tükel Ç. In vivo synthesis of bacterial amyloid curli contributes to joint inflammation during S. Typhimurium infection. PLoS Pathog 2020; 16:e1008591. [PMID: 32645118 PMCID: PMC7347093 DOI: 10.1371/journal.ppat.1008591] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 05/01/2020] [Indexed: 12/16/2022] Open
Abstract
Reactive arthritis, an autoimmune disorder, occurs following gastrointestinal infection with invasive enteric pathogens, such as Salmonella enterica. Curli, an extracellular, bacterial amyloid with cross beta-sheet structure can trigger inflammatory responses by stimulating pattern recognition receptors. Here we show that S. Typhimurium produces curli amyloids in the cecum and colon of mice after natural oral infection, in both acute and chronic infection models. Production of curli was associated with an increase in anti-dsDNA autoantibodies and joint inflammation in infected mice. The negative impacts on the host appeared to be dependent on invasive systemic exposure of curli to immune cells. We hypothesize that in vivo synthesis of curli contributes to known complications of enteric infections and suggest that cross-seeding interactions can occur between pathogen-produced amyloids and amyloidogenic proteins of the host. Our manuscript focuses on curli, a ‘functional amyloid’ produced by Salmonella as well as other enteric bacteria. We present the first biochemical evidence that these fibers are produced in the gastrointestinal tract of mice after oral infection, the natural route for Salmonella infections. This finding is significant because of the immune impacts on the host; we show that curli cause an increase in autoimmunity and inflammation in the knee joints of infected mice. Reactive arthritis is a known autoimmune complication after enteric infections and our results indicate that presence of curli in the gut provides a novel linchpin of pathogenesis. As curli or curli-like amyloids are also produced by the commensal bacteria, it is possible that the unintended release of amyloids produced by the microbiota could trigger similar autoimmune reactions. Finally, our work provides conceptual evidence for the possibility of cross-seeding between bacterial amyloids like curli and human amyloids involved in amyloid-associated diseases such as Alzheimer’s Disease via the gut microbiome or infections.
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Affiliation(s)
- Amanda L. Miller
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - J. Alex Pasternak
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
| | - Nicole J. Medeiros
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Lauren K. Nicastro
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Sarah A. Tursi
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Elizabeth G. Hansen
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Ryan Krochak
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Akosiererem S. Sokaribo
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Keith D. MacKenzie
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Melissa B. Palmer
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Dakoda J. Herman
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Nikole L. Watson
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Yi Zhang
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Heather L. Wilson
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
| | - R. Paul Wilson
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Aaron P. White
- Vaccine and Infectious Disease Organization-International Vaccine Centre, Saskatoon, Saskatchewan, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- * E-mail: (APW); (CT)
| | - Çagla Tükel
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
- * E-mail: (APW); (CT)
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Sokaribo AS, Hansen EG, McCarthy M, Desin TS, Waldner LL, MacKenzie KD, Mutwiri G, Herman NJ, Herman DJ, Wang Y, White AP. Metabolic Activation of CsgD in the Regulation of Salmonella Biofilms. Microorganisms 2020; 8:E964. [PMID: 32604994 PMCID: PMC7409106 DOI: 10.3390/microorganisms8070964] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/09/2020] [Accepted: 06/20/2020] [Indexed: 12/31/2022] Open
Abstract
Among human food-borne pathogens, gastroenteritis-causing Salmonella strains have the most real-world impact. Like all pathogens, their success relies on efficient transmission. Biofilm formation, a specialized physiology characterized by multicellular aggregation and persistence, is proposed to play an important role in the Salmonella transmission cycle. In this manuscript, we used luciferase reporters to examine the expression of csgD, which encodes the master biofilm regulator. We observed that the CsgD-regulated biofilm system responds differently to regulatory inputs once it is activated. Notably, the CsgD system became unresponsive to repression by Cpx and H-NS in high osmolarity conditions and less responsive to the addition of amino acids. Temperature-mediated regulation of csgD on agar was altered by intracellular levels of RpoS and cyclic-di-GMP. In contrast, the addition of glucose repressed CsgD biofilms seemingly independent of other signals. Understanding the fine-tuned regulation of csgD can help us to piece together how regulation occurs in natural environments, knowing that all Salmonella strains face strong selection pressures both within and outside their hosts. Ultimately, we can use this information to better control Salmonella and develop strategies to break the transmission cycle.
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Affiliation(s)
- Akosiererem S. Sokaribo
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada;
| | - Elizabeth G. Hansen
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
| | - Madeline McCarthy
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada;
| | - Taseen S. Desin
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada;
- Basic Sciences Department, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11481, Saudi Arabia
| | - Landon L. Waldner
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
| | - Keith D. MacKenzie
- Institute for Microbial Systems and Society, Faculty of Science, University of Regina, Regina, SK S4S 0A2, Canada;
- Department of Biology, University of Regina, Regina, SK S4S 0A2, Canada
| | - George Mutwiri
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
| | - Nancy J. Herman
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
| | - Dakoda J. Herman
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
| | - Yejun Wang
- Department of Cell Biology and Genetics, School of Basic Medicine, Shenzhen University Health Science, Shenzhen 518060, China;
| | - Aaron P. White
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada; (A.S.S.); (E.G.H.); (M.M.); (L.L.W.); (G.M.J.); (N.J.H.); (D.J.H.)
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada;
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Transcriptional changes involved in inhibition of biofilm formation by ε-polylysine in Salmonella Typhimurium. Appl Microbiol Biotechnol 2020; 104:5427-5436. [PMID: 32307570 DOI: 10.1007/s00253-020-10575-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 03/05/2020] [Accepted: 03/22/2020] [Indexed: 01/08/2023]
Abstract
The pathogenicity of Salmonella Typhimurium, a foodborne pathogen, is mainly attributed to its ability to form biofilm on food contact surfaces. ε-polylysine, a polymer of positively charged lysine, is reported to inhibit biofilm formation of both gram-positive and gram-negative bacteria. To elucidate the mechanism underlying ε-polylysine-mediated inhibition of biofilm formation, the transcriptional profiles of ε-polylysine-treated and untreated Salmonella Typhimurium cells were comparatively analysed. The genome-wide DNA microarray analysis was performed using Salmonella Typhimurium incubated with 0.001% ε-polylysine in 0.1% Bacto Soytone at 30 °C for 2 h. The expression levels of genes involved in curli amyloid fibres and cellulose production, quorum sensing, and flagellar motility were downregulated, whereas those of genes associated with colanic acid synthesis were upregulated after treatment with ε-polylysine. The microarray results were validated by quantitative real-time polymerase chain reaction (qRT-PCR). Furthermore, treatment with ε-polylysine decreased the production of colanic acid in Salmonella Typhimurium. The findings of this study improved our understanding of the mechanisms underlying ε-polylysine-mediated biofilm inhibition and may contribute to the development of new disinfectants to control biofilm during food manufacturing and storage.
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Leech J, Golub S, Allan W, Simmons MJH, Overton TW. Non-pathogenic Escherichia coli biofilms: effects of growth conditions and surface properties on structure and curli gene expression. Arch Microbiol 2020; 202:1517-1527. [PMID: 32222779 PMCID: PMC7355273 DOI: 10.1007/s00203-020-01864-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 02/21/2020] [Accepted: 03/12/2020] [Indexed: 11/28/2022]
Abstract
Biofilm formation is a harmful phenomenon in many areas, such as in industry and clinically, but offers advantages in the field of biocatalysis for the generation of robust biocatalytic platforms. In this work, we optimised growth conditions for the production of Escherichia coli biofilms by three strains (PHL644, a K-12 derivative with enhanced expression of the adhesin curli; the commercially-used strain BL21; and the probiotic Nissle 1917) on a variety of surfaces (plastics, stainless steel and PTFE). E. coli PHL644 and PTFE were chosen as optimal strain and substratum, respectively, and conditions (including medium, temperature, and glucose concentration) for biofilm growth were determined. Finally, the impact of these growth conditions on expression of the curli genes was determined using flow cytometry for planktonic and sedimented cells. We reveal new insights into the formation of biofilms and expression of curli in E. coli K-12 in response to environmental conditions.
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Affiliation(s)
- James Leech
- School of Chemical Engineering, College of Engineering and Physical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,School of Biosciences, University of Kent, Canterbury, Kent, CT2 7NH, UK
| | - Stacey Golub
- School of Chemical Engineering, College of Engineering and Physical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Wendy Allan
- School of Chemical Engineering, College of Engineering and Physical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Mark J H Simmons
- School of Chemical Engineering, College of Engineering and Physical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Tim W Overton
- School of Chemical Engineering, College of Engineering and Physical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK. .,Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
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Romilly C, Hoekzema M, Holmqvist E, Wagner EGH. Small RNAs OmrA and OmrB promote class III flagellar gene expression by inhibiting the synthesis of anti-Sigma factor FlgM. RNA Biol 2020; 17:872-880. [PMID: 32133913 PMCID: PMC7549644 DOI: 10.1080/15476286.2020.1733801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Bacteria can move by a variety of mechanisms, the best understood being flagella-mediated motility. Flagellar genes are organized in a three-tiered cascade allowing for temporally regulated expression that involves both transcriptional and post-transcriptional control. The class I operon encodes the master regulator FlhDC that drives class II gene transcription. Class II genes include fliA and flgM, which encode the Sigma factor σ28, required for class III transcription, and the anti-Sigma factor FlgM, which inhibits σ28 activity, respectively. The flhDC mRNA is regulated by several small regulatory RNAs (sRNAs). Two of these, the sequence-related OmrA and OmrB RNAs, inhibit FlhD synthesis. Here, we report on a second layer of sRNA-mediated control downstream of FhlDC in the flagella pathway. By mutational analysis, we confirm that a predicted interaction between the conserved 5ʹ seed sequences of OmrA/B and the early coding sequence in flgM mRNA reduces FlgM expression. Regulation is dependent on the global RNA-binding protein Hfq. In vitro experiments support a canonical mechanism: binding of OmrA/B prevents ribosome loading and decreases FlgM protein synthesis. Simultaneous inhibition of both FlhD and FlgM synthesis by OmrA/B complicated an assessment of how regulation of FlgM alone impacts class III gene transcription. Using a combinatorial mutation strategy, we were able to uncouple these two targets and demonstrate that OmrA/B-dependent inhibition of FlgM synthesis liberates σ28 to ultimately promote higher expression of the class III flagellin gene fliC.
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Affiliation(s)
- Cédric Romilly
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University , Uppsala, Sweden
| | - Mirthe Hoekzema
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University , Uppsala, Sweden
| | - Erik Holmqvist
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University , Uppsala, Sweden
| | - E Gerhart H Wagner
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University , Uppsala, Sweden
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Chen J, Wang Y. Genetic determinants of Salmonella enterica critical for attachment and biofilm formation. Int J Food Microbiol 2020; 320:108524. [PMID: 32000116 DOI: 10.1016/j.ijfoodmicro.2020.108524] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 01/17/2020] [Accepted: 01/20/2020] [Indexed: 12/21/2022]
Abstract
Salmonella is a bacterial pathogen frequently involved in human gastrointestinal infections including those associated with low-moisture foods such as dehydrated food powders/spices, vegetable seeds, and tree nuts. The survival/persistence of Salmonella on low moisture foods and in dry environments is enhanced by its ability in developing biofilms. This study was undertaken to identify the genetic determinants critical for Salmonella attachment and biofilm formation. E. coli SM10 lambda pir, with a kanamycin resistant marker on mini-Tn10 (mini-Tn10:lacZ:kanr), an ampicillin resistant marker on the mini-Tn10-bearing suicidal plasmid pLBT and a streptomycin sensitive marker on the SM10 chromosome, was used as a donor (ampr, kanr, streps), and three Salmonella strains (amps, kans, strepr) were used as recipients in a transposon mutagenesis study. The donor and each recipient were co-incubated overnight on tryptic soy agar at 37 °C, and mutant colonies (amps, kanr, strepr) were subsequently selected. A single-banded degenerate PCR product, amplified from each mutant genome using oligonucleotide primers derived from the end of min-Tn10 and restriction enzyme EcoR I- or Pst I-recognizing sequence, were analyzed using the Sanger sequencing technology. Acquired DNA sequences were compared to those deposited in the Genbank using BLAST search. Cells of Salmonella mutants accumulated either significantly more or less (P < 0.05) biofilms than their parent cells on polystyrene surface. Sequence analysis of degenerate PCR products revealed that the mini-Tn10 from pLBT had inserted into the cdg, trx, fadI or rxt on Salmonella chromosomes. Results of the research will likely help strategize future antimicrobial intervention for control of pathogen attachment and biofilm formation.
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Affiliation(s)
- Jinru Chen
- Department of Food Science and Technology, The University of Georgia, 1109 Experiment St., Griffin, GA 30223-1797, USA.
| | - Yin Wang
- Department of Food Science and Technology, The University of Georgia, 1109 Experiment St., Griffin, GA 30223-1797, USA
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Kenney LJ, Anand GS. EnvZ/OmpR Two-Component Signaling: An Archetype System That Can Function Noncanonically. EcoSal Plus 2020; 9:10.1128/ecosalplus.ESP-0001-2019. [PMID: 32003321 PMCID: PMC7192543 DOI: 10.1128/ecosalplus.esp-0001-2019] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Indexed: 01/09/2023]
Abstract
Two-component regulatory systems represent the major paradigm for signal transduction in prokaryotes. The simplest systems are composed of a sensor kinase and a response regulator. The sensor is often a membrane protein that senses a change in environmental conditions and is autophosphorylated by ATP on a histidine residue. The phosphoryl group is transferred onto an aspartate of the response regulator, which activates the regulator and alters its output, usually resulting in a change in gene expression. In this review, we present a historical view of the archetype EnvZ/OmpR two-component signaling system, and then we provide a new view of signaling based on our recent experiments. EnvZ responds to cytoplasmic signals that arise from changes in the extracellular milieu, and OmpR acts canonically (requiring phosphorylation) to regulate the porin genes and noncanonically (without phosphorylation) to activate the acid stress response. Herein, we describe how insights gleaned from stimulus recognition and response in EnvZ are relevant to nearly all sensor kinases and response regulators.
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Affiliation(s)
- Linda J Kenney
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555
- Mechanobiology Institute, T-Lab, National University of Singapore, Singapore
| | - Ganesh S Anand
- Department of Biological Sciences, National University of Singapore, Singapore
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45
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Nimnoi P, Pongsilp N. Distribution and expression of virulence genes in potentially pathogenic bacteria isolated from seafood in Thailand. CYTA - JOURNAL OF FOOD 2020. [DOI: 10.1080/19476337.2020.1842502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Pongrawee Nimnoi
- Department of Microbiology, Faculty of Liberal Arts and Science, Kasetsart University, Nakhon Pathom, Thailand
| | - Neelawan Pongsilp
- Department of Microbiology, Faculty of Science, Silpakorn University, Nakhon Pathom, Thailand
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46
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Genome engineering of E. coli for improved styrene production. Metab Eng 2020; 57:74-84. [DOI: 10.1016/j.ymben.2019.09.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/18/2019] [Accepted: 09/12/2019] [Indexed: 01/01/2023]
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Bansal M, Nannapaneni R, Kode D, Chang S, Sharma CS, McDaniel C, Kiess A. Rugose Morphotype in Salmonella Typhimurium and Salmonella Heidelberg Induced by Sequential Exposure to Subinhibitory Sodium Hypochlorite Aids in Biofilm Tolerance to Lethal Sodium Hypochlorite on Polystyrene and Stainless Steel Surfaces. Front Microbiol 2019; 10:2704. [PMID: 31827464 PMCID: PMC6890808 DOI: 10.3389/fmicb.2019.02704] [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] [Received: 05/03/2019] [Accepted: 11/07/2019] [Indexed: 01/02/2023] Open
Abstract
Salmonella biofilms act as a continuous source for cross-contamination in the food processing environments. In this study, a stable rugose morphotype of Salmonella was first induced by sequential exposure to subinhibitory concentrations (SICs) of sodium hypochlorite (NaOCl) (ranging from 50 to 300 ppm over 18-day period) in tryptic soy broth. Then, rugose and smooth morphotypes of Salmonella Typhimurium ATCC 14028 and Salmonella Heidelberg ATCC 8326 were characterized for biofilm forming abilities on polystyrene and stainless steel surfaces. Rugose morphotype of both ATCC 14028 and ATCC 8326 exhibited higher Exopolysaccharide (EPS) formation than smooth morphotype (p ≤ 0.05). Also, the SICs of NaOCl (200 or 300 ppm in broth model) increased the biofilm formation ability of rugose morphotype of ATCC 8326 (p ≤ 0.05) but decreased that of ATCC 14028. The 2-day-old Salmonella biofilms were treated with biocidal concentrations of 50, 100, or 200 ppm NaOCl (pH 6.15) in water for 5, 10, or 20 min at room temperature. The biofilm reduction in CFU/cm2 for the rugose was lower than the smooth morphotype on both surfaces (p ≤ 0.05) by lethal NaOCl in water. Scanning electron micrographs on both polystyrene and stainless steel surfaces demonstrated that the rugose morphotype produced a denser biofilm than the smooth morphotype. Transmission electron micrographs revealed the cell wall roughness in rugose morphotype, which may help in tolerance to NaOCl. The gene expression data indicate that the expression of biofilm regulator (csgD), curli (csgA, csgB, and csgC), and cellulose (bcsE) was significantly increased in rugose morphotype when induced by sequential exposure of NaOCl SICs. These findings reveal that the rugose morphotype of S. Typhimurium and S. Heidelberg produced significantly denser biofilm on food contact surfaces, which also increased with sequential exposure to SICs of NaOCl in the case of S. Heidelberg, and these biofilms were more tolerant to biocidal NaOCl concentrations commonly used in the food processing plants.
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Affiliation(s)
- Mohit Bansal
- Department of Poultry Science, Mississippi State University, Mississippi State, MS, United States
| | - Ramakrishna Nannapaneni
- Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, MS, United States
| | - Divya Kode
- Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, MS, United States
| | - Sam Chang
- Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, MS, United States
| | - Chander S. Sharma
- Department of Poultry Science, Mississippi State University, Mississippi State, MS, United States
| | - Christopher McDaniel
- Department of Poultry Science, Mississippi State University, Mississippi State, MS, United States
| | - Aaron Kiess
- Department of Poultry Science, Mississippi State University, Mississippi State, MS, United States
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Yu L, Li W, Qi K, Wang S, Chen X, Ni J, Deng R, Shang F, Xue T. McbR is involved in biofilm formation and H2O2 stress response in avian pathogenic Escherichia coli X40. Poult Sci 2019; 98:4094-4103. [PMID: 31002106 DOI: 10.3382/ps/pez205] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/22/2019] [Indexed: 11/20/2022] Open
Abstract
Avian pathogenic Escherichia coli (APEC) causes a variety of extraintestinal diseases known as colibacillosis and is responsible for significant economic losses in the poultry industry worldwide. Biofilm formation results in increased morbidity and persistent infections, and is the main reason for the difficult treatment of colibacillosis with antimicrobial agents. It is reported that the transcriptional regulator McbR regulates biofilm formation and mucoidy by repressing the expression of the periplasmic protein YbiM, and activates the transcription of the yciGFE operon by binding to the yciG promoter in E. coli K-12. However, whether McbR regulates biofilm formation and H2O2 stress response in APEC has been not reported. The present study showed that, in the clinical isolate APECX40, the deletion of mcbR increased biofilm formation by upregulating the transcription of the biofilm-associated genes bcsA, fliC, wcaF, and fimA. In addition, the deletion of mcbR decreased H2O2 stress response by downregulating the transcript levels of the stress-associated genes yciF and yciE. The electrophoretic mobility shift assays confirmed that McbR directly binds to the promoter regions of yciG and yciF. This study may provide new clues to understanding gene regulation in APEC.
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Affiliation(s)
- Lumin Yu
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Wenchang Li
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Kezong Qi
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Hefei, Anhui 230036, China
| | - Siyu Wang
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Xiaolin Chen
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Jingtian Ni
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Ruining Deng
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Fei Shang
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Ting Xue
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
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Shi Z, Dittoe DK, Ricke SC. Non-molecular characterization of pellicle formation by poultry Salmonella Kentucky strains and other poultry-associated Salmonella serovars in Luria Bertani broth. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2019; 54:972-978. [PMID: 31496354 DOI: 10.1080/03601234.2019.1661210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
There is limited research concerning the biofilm-forming capabilities of Salmonella Kentucky, a common poultry isolate. The objective was to quantitate pellicle formation of S. Kentucky versus better-characterized Salmonella strains of Enteritidis and Heidelberg. In separate experiments, Salmonella strains and serovars were tested for their biofilm-forming abilities in different Luria-Bertani (LB) broths (1); pellicle formation in different volumes of LB without salt (2); and the potential priming effects on formation after pellicles were transferred three consecutive times (3). Data were analyzed using One-Way ANOVA with means separated using Tukey's HSD (P ≤ 0.05). In the first experiment, there was no significant effect between strain and serovars (P > 0.05), but media type affected pellicle formation significantly with LB Miller and LB minus NaCl plus 2% glucose resulting in no pellicle formation (P < 0.001). When grown in 50 mL, Kentucky 38-0085 produced larger pellicles than Kentucky 38-0055, and Heidelberg strain 38-0127 (P < 0.0001). Serial transfers of pellicles did not significantly affect pellicle formation (P > 0.05); however, Kentucky 38-0084, 38-0085 and 38-0086 produced larger pellicles than Kentucky 38-0055 and 38-0056 and Heidelberg 38-0126, 38-0127 and 38-0152. The current study demonstrates the consistent biofilm forming capabilities of Kentucky and may explain why Kentucky is frequently isolated in poultry processing facilities.
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Affiliation(s)
- Zhaohao Shi
- Center for Food Safety and Food Science Department, University of Arkansas, Fayetteville, AR, USA
| | - Dana K Dittoe
- Center for Food Safety and Food Science Department, University of Arkansas, Fayetteville, AR, USA
| | - Steven C Ricke
- Center for Food Safety and Food Science Department, University of Arkansas, Fayetteville, AR, USA
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50
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Luna-Pineda VM, Moreno-Fierros L, Cázares-Domínguez V, Ilhuicatzi-Alvarado D, Ochoa SA, Cruz-Córdova A, Valencia-Mayoral P, Rodríguez-Leviz A, Xicohtencatl-Cortes J. Curli of Uropathogenic Escherichia coli Enhance Urinary Tract Colonization as a Fitness Factor. Front Microbiol 2019; 10:2063. [PMID: 31551993 PMCID: PMC6733918 DOI: 10.3389/fmicb.2019.02063] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 08/21/2019] [Indexed: 01/24/2023] Open
Abstract
Curli, a type of fimbriae widely distributed in uropathogenic Escherichia coli (UPEC), are involved in adhesion to human bladder cell surfaces and biofilm development. The role of UPEC curli was evaluated in a murine model of urinary tract infection. The aim of this study was to establish the role of curli in C57BL/6 mice transurethrally infected with curli-producing and non-curli-producing UPEC strains. We confirmed that curli enhanced UPEC colonization in the urinary tract, resulting in damage to both the bladder and kidney. Intranasal immunization with recombinant CsgA protein protected against colonization by curli-producing UPEC in the urinary tract. Quantification of cytokines from urinary tract organs showed increases in interleukin-6 and tumor necrosis factor (TNF) release in the kidneys 48 h postinfection with curli-producing UPEC. By contrast, mice infected with non-curli-producing UPEC showed the highest release of interleukin-6, -10, and -17A and TNF. Curli may obscure other fimbriae and LPS, preventing interactions with Toll-like receptors. When intranasal immunization with recombinant FimH and PapG proteins and subsequent infection with this strain were performed, cytokine quantification showed a decrease in the stimulation and release by the uroepithelium. Thus, curli are amyloid-like fimbriae that enhances colonization in the urinary tract and a possible fitness factor.
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Affiliation(s)
- Víctor M Luna-Pineda
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México "Federico Gómez", Mexico City, Mexico
| | - Leticia Moreno-Fierros
- Laboratorio de Inmunidad en Mucosas, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Vicenta Cázares-Domínguez
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México "Federico Gómez", Mexico City, Mexico
| | - Damaris Ilhuicatzi-Alvarado
- Laboratorio de Inmunidad en Mucosas, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Sara A Ochoa
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México "Federico Gómez", Mexico City, Mexico
| | - Ariadnna Cruz-Córdova
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México "Federico Gómez", Mexico City, Mexico
| | - Pedro Valencia-Mayoral
- Departamento de Patología, Hospital Infantil de México "Federico Gómez", Mexico City, Mexico
| | | | - Juan Xicohtencatl-Cortes
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México "Federico Gómez", Mexico City, Mexico
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