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Niño-Arias FC, Alves VF, Pereira MG, De Martinis ECP. Gene expression and cell culture assays reveal cheese isolate Lactococcus lactis MC5 may influence the virulence of Staphylococcus aureus. Braz J Microbiol 2023; 54:2027-2034. [PMID: 37171534 PMCID: PMC10484841 DOI: 10.1007/s42770-023-01004-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 04/29/2023] [Indexed: 05/13/2023] Open
Abstract
Staphylococcus aureus (SA) can thrive in a wide variety of hosts and environments, causing clinical infections and foodborne intoxications. In Brazil, SA is commonly isolated from traditional soft cheeses, especially those prepared from unpasteurized milk. In this research, the isolate S. aureus SABRC1 was evaluated for virulence traits under different conditions, including co-inoculation with Lactococcus lactis MC5 (isolated from "Fresh Minas Cheese"), which produces antibacterial peptides. Results from experiments with Caco-2 culture indicated S. aureus SABRC1 was able to adhere (42.83 ± 1.79%) and to invade (48.57 ± 0.41%) the intestinal cells. On the other hand, L. lactis MC5 presented anti-staphylococcal activity as indicated by agar assays, and it was also able to antagonize intestinal cell invasion by S. aureus. Moreover, Reverse Transcriptase-PCR experiments showed virulence genes of S. aureus SABRC1 (hla, icaA and sea) were differentially expressed under diverse culture conditions, which included Brain Heart Infusion modified or not by the addition of glucose, sodium chloride, milk or cheese. This suggests the virulence of S. aureus SABRC1 is influenced by compounds commonly found in daily diets, and not only by its genetic repertoire, adding a novel level of complexity for controlling infection by this pathogen.
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Affiliation(s)
- Fabian Camilo Niño-Arias
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto (FCFRP-USP), Brazil
| | - Virgínia Farias Alves
- Faculdade de Farmácia, Universidade Federal de Goiás, Rua 240 Esquina Com a 5ª Avenida, S/N, Setor Leste Universitário, Goiânia/GO, CEP: 74605-170, Brazil.
| | - Marita Gimenez Pereira
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto (FCFRP-USP), Brazil
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2
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Roux AE, Robert S, Bastat M, Rosinski-Chupin I, Rong V, Holbert S, Mereghetti L, Camiade E. The Role of Regulator Catabolite Control Protein A (CcpA) in Streptococcus agalactiae Physiology and Stress Response. Microbiol Spectr 2022; 10:e0208022. [PMID: 36264242 PMCID: PMC9784791 DOI: 10.1128/spectrum.02080-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 09/21/2022] [Indexed: 01/06/2023] Open
Abstract
Streptococcus agalactiae is a leading cause of infections in neonates. This opportunistic pathogen colonizes the vagina, where it has to cope with acidic pH and hydrogen peroxide produced by lactobacilli. Thus, in the host, this bacterium possesses numerous adaptation mechanisms in which the pleiotropic regulators play a major role. The transcriptional regulator CcpA (catabolite control protein A) has previously been shown to be the major regulator involved in carbon catabolite repression in Gram-positive bacteria but is also involved in other functions. By transcriptomic analysis, we characterized the CcpA-dependent gene regulation in S. agalactiae. Approximately 13.5% of the genome of S. agalactiae depends on CcpA for regulation and comprises genes involved in sugar uptake and fermentation, confirming the role of CcpA in carbon metabolism. We confirmed by electrophoretic mobility shift assays (EMSAs) that the DNA binding site called cis-acting catabolite responsive element (cre) determined for other streptococci was effective in S. agalactiae. We also showed that CcpA is of capital importance for survival under acidic and oxidative stresses and is implicated in macrophage survival by regulating several genes putatively or already described as involved in stress response. Among them, we focused our study on SAK_1689, which codes a putative UspA protein. We demonstrated that SAK_1689, highly downregulated by CcpA, is overexpressed under oxidative stress conditions, this overexpression being harmful for the bacterium in a ΔccpA mutant. IMPORTANCE Streptococcus agalactiae is a major cause of disease burden leading to morbidity and mortality in neonates worldwide. Deciphering its adaptation mechanisms is essential to understand how this bacterium manages to colonize its host. Here, we determined the regulon of the pleiotropic regulator CcpA in S. agalactiae. Our findings reveal that CcpA is not only involved in carbon catabolite repression, but is also important for acidic and oxidative stress resistance and survival in macrophages.
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Affiliation(s)
| | | | | | - Isabelle Rosinski-Chupin
- Unité Écologie et Évolution de la Résistance aux Antibiotiques, CNRS UMR3525, Institut Pasteur, Paris, France
| | | | | | - Laurent Mereghetti
- ISP, Université de Tours, INRAE, Tours, France
- CHRU Tours, Service de Bactériologie-Virologie-Hygiène, Tours, France
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3
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Derix J, Ducatelle R, Pardon B, Croes E, Nibbelink NG, Van Deurzen-Duineveld L, Van Immerseel F, Goossens E. The in vitro effect of lactose on Clostridium perfringens alpha toxin production and the implications of lactose consumption for in vivo anti-alpha toxin antibody production. J Dairy Sci 2022; 106:733-742. [DOI: 10.3168/jds.2022-22467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/02/2022] [Indexed: 11/13/2022]
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DebRoy S, Aliaga-Tobar V, Galvez G, Arora S, Liang X, Horstmann N, Maracaja-Coutinho V, Latorre M, Hook M, Flores AR, Shelburne SA. Genome-wide analysis of in vivo CcpA binding with and without its key co-factor HPr in the major human pathogen group A Streptococcus. Mol Microbiol 2020; 115:1207-1228. [PMID: 33325565 PMCID: PMC8359418 DOI: 10.1111/mmi.14667] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 12/02/2020] [Accepted: 12/11/2020] [Indexed: 01/01/2023]
Abstract
Catabolite control protein A (CcpA) is a master regulator of carbon source utilization and contributes to the virulence of numerous medically important Gram‐positive bacteria. Most functional assessments of CcpA, including interaction with its key co‐factor HPr, have been performed in nonpathogenic bacteria. In this study we aimed to identify the in vivo DNA binding profile of CcpA and assess the extent to which HPr is required for CcpA‐mediated regulation and DNA binding in the major human pathogen group A Streptococcus (GAS). Using a combination RNAseq/ChIP‐seq approach, we found that CcpA affects transcript levels of 514 of 1667 GAS genes (31%) whereas direct DNA binding was identified for 105 GAS genes. Three of the directly regulated genes encode the key GAS virulence factors Streptolysin S, PrtS (IL‐8 degrading proteinase), and SpeB (cysteine protease). Mutating CcpA Val301 to Ala (strain 2221‐CcpA‐V301A) abolished interaction between CcpA and HPr and impacted the transcript levels of 205 genes (40%) in the total CcpA regulon. By ChIP‐seq analysis, CcpAV301A bound to DNA from 74% of genes bound by wild‐type CcpA, but generally with lower affinity. These data delineate the direct CcpA regulon and clarify the HPr‐dependent and independent activities of CcpA in a key pathogenic bacterium.
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Affiliation(s)
- Sruti DebRoy
- Department of Infectious Diseases Infection Control and Employee Health, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Victor Aliaga-Tobar
- Facultad de Ciencias Químicas y Farmacéuticas, Advanced Center for Chronic Diseases-ACCDiS, Universidad de Chile, Independencia, Chile.,Laboratorio de Bioingeniería, Instituto de Ciencias de la Ingeniería, Universidad de O'Higgins, Rancagua, Chile
| | - Gabriel Galvez
- Laboratorio de Bioingeniería, Instituto de Ciencias de la Ingeniería, Universidad de O'Higgins, Rancagua, Chile
| | - Srishtee Arora
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA
| | - Xiaowen Liang
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA
| | - Nicola Horstmann
- Department of Infectious Diseases Infection Control and Employee Health, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Vinicius Maracaja-Coutinho
- Facultad de Ciencias Químicas y Farmacéuticas, Advanced Center for Chronic Diseases-ACCDiS, Universidad de Chile, Independencia, Chile.,Centro de Modelamiento Molecular, Biofísica y Bioinformática (CM2B2), Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Mauricio Latorre
- Laboratorio de Bioingeniería, Instituto de Ciencias de la Ingeniería, Universidad de O'Higgins, Rancagua, Chile.,Laboratorio de Bioinformática y Expresión Génica, INTA, Universidad de Chile, Santiago, Chile.,Mathomics, Center for Mathematical Modeling, Universidad de Chile, Santiago, Chile.,Center for Genome Regulation (Fondap 15090007), Universidad de Chile, Santiago, Chile
| | - Magnus Hook
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA
| | - Anthony R Flores
- Division of Infectious Diseases, Department of Pediatrics, University of Texas Health Science Center McGovern Medical School, Houston, TX, USA.,Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center McGovern Medical School, Houston, TX, USA
| | - Samuel A Shelburne
- Department of Infectious Diseases Infection Control and Employee Health, University of Texas MD Anderson Cancer Center, Houston, TX, USA.,Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center McGovern Medical School, Houston, TX, USA.,Department of Genomic Medicine, University of Texas MD Anderson Cancer Center, Houston TX, USA
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Shivappagowdar A, Pati S, Narayana C, Ayana R, Kaushik H, Sah R, Garg S, Khanna A, Kumari J, Garg L, Sagar R, Singh S. A small bioactive glycoside inhibits epsilon toxin and prevents cell death. Dis Model Mech 2019; 12:dmm.040410. [PMID: 31492678 PMCID: PMC6826021 DOI: 10.1242/dmm.040410] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Accepted: 08/23/2019] [Indexed: 12/24/2022] Open
Abstract
Clostridium perfringens epsilon toxin (Etx) is categorized as the third most lethal bioterrorism agent by the Centers for Disease Control and Prevention (CDC), with no therapeutic counter measures available for humans. Here, we have developed a high-affinity inhibitory compound by synthesizing and evaluating the structure activity relationship (SAR) of a library of diverse glycosides (numbered 1-12). SAR of glycoside-Etx heptamers revealed exceptionally strong H-bond interactions of glycoside-4 with a druggable pocket in the oligomerization and β-hairpin region of Etx. Analysis of its structure suggested that glycoside-4 might self-aggregate to form a robust micelle-like supra-molecular complex due to its linear side-chain architecture, which was authenticated by fluorescence spectroscopy. Further, this micelle hinders the Etx monomer-monomer interaction required for oligomerization, validated by both surface plasmon resonance (SPR) and immunoblotting. This phenomenon in turn leads to blockage of pore formation. Downstream evaluation revealed that glycoside-4 effectively blocked cell death of Etx-treated cultured primary cells and maintained cellular homeostasis via disrupting oligomerization, blocking pore formation, restoring calcium homeostasis, stabilizing the mitochondrial membrane and impairing high mobility group box 1 (HMGB1) translocation from nucleus to cytoplasm. Furthermore, a single dosage of glycoside-4 protected the Etx-challenged mice and restored normal function to multiple organs. This work reports for the first time a potent, nontoxic glycoside with strong ability to occlude toxin lethality, representing it as a bio-arm therapeutic against Etx-based biological threat.
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Affiliation(s)
- Abhishek Shivappagowdar
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Greater Noida, Uttar Pradesh 201314, India
| | - Soumya Pati
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Greater Noida, Uttar Pradesh 201314, India
| | - Chintam Narayana
- Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Greater Noida, Uttar Pradesh 201314, India
| | - Rajagopal Ayana
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Greater Noida, Uttar Pradesh 201314, India
| | - Himani Kaushik
- Gene Regulation Laboratory, National Institute of Immunology, New Delhi 110067, India
| | - Raj Sah
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India
| | - Swati Garg
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Greater Noida, Uttar Pradesh 201314, India
| | - Ashish Khanna
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Jyoti Kumari
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Greater Noida, Uttar Pradesh 201314, India
| | - Lalit Garg
- Gene Regulation Laboratory, National Institute of Immunology, New Delhi 110067, India
| | - Ram Sagar
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Shailja Singh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India
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Porta E, Cogliati S, Francisco M, Roldán MV, Mamana N, Grau R, Pellegri N. Stable Colloidal Copper Nanoparticles Functionalized with Siloxane Groups and Their Microbicidal Activity. J Inorg Organomet Polym Mater 2019. [DOI: 10.1007/s10904-018-01071-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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A Multi-Serotype Approach Clarifies the Catabolite Control Protein A Regulon in the Major Human Pathogen Group A Streptococcus. Sci Rep 2016; 6:32442. [PMID: 27580596 PMCID: PMC5007534 DOI: 10.1038/srep32442] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 08/04/2016] [Indexed: 12/20/2022] Open
Abstract
Catabolite control protein A (CcpA) is a highly conserved, master regulator of carbon source utilization in gram-positive bacteria, but the CcpA regulon remains ill-defined. In this study we aimed to clarify the CcpA regulon by determining the impact of CcpA-inactivation on the virulence and transcriptome of three distinct serotypes of the major human pathogen Group A Streptococcus (GAS). CcpA-inactivation significantly decreased GAS virulence in a broad array of animal challenge models consistent with the idea that CcpA is critical to gram-positive bacterial pathogenesis. Via comparative transcriptomics, we established that the GAS CcpA core regulon is enriched for highly conserved CcpA binding motifs (i.e. cre sites). Conversely, strain-specific differences in the CcpA transcriptome seems to consist primarily of affected secondary networks. Refinement of cre site composition via analysis of the core regulon facilitated development of a modified cre consensus that shows promise for improved prediction of CcpA targets in other medically relevant gram-positive pathogens.
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Azzopardi E, Lloyd C, Teixeira SR, Conlan RS, Whitaker IS. Clinical applications of amylase: Novel perspectives. Surgery 2016; 160:26-37. [PMID: 27117578 DOI: 10.1016/j.surg.2016.01.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Revised: 12/20/2015] [Accepted: 01/08/2016] [Indexed: 12/13/2022]
Abstract
BACKGROUND Amylase was the first enzyme to be characterized, and for the previous 200 years, its clinical role has been restricted to a diagnostic aid. Recent interface research has led to a substantial expansion of its role into novel, viable diagnostic, and therapeutic applications to cancer, infection, and wound healing. This review provides a concise "state-of-the-art" overview of the genetics, structure, distribution, and localization of amylase in humans. METHOD A first-generation literature search was performed with the MeSH search string "Amylase AND (diagnost∗ OR therapeut$)" on OVIDSP and PUBMED platforms. A second-generation search was then performed by forward and backward referencing on Web of Knowledge™ and manual indexing, limited to the English Language. RESULTS "State of the Art" in amylase genetics, structure, function distribution, localisation and detection of amylase in humans is provided. To the 4 classic patterns of hyperamylasemia (pancreatic, salivary, macroamylasemia, and combinations) a fifth, the localized targeting of amylase to specific foci of infection, is proposed. CONCLUSIONS The implications are directed at novel therapeutic and diagnostic clinical applications of amylase such as the novel therapeutic drug classes capable of targeted delivery and "smart release" in areas of clinical need. Future directions of research in areas of high clinical benefit are reported.
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Affiliation(s)
- Ernest Azzopardi
- Reconstructive Surgery and Regenerative Medicine Group, Swansea University, Swansea, United Kingdom; Centre for Nanohealth, Swansea University, Swansea, United Kingdom; The Welsh Centre for Burns and Plastic Surgery, Morriston Hospital, Swansea, United Kingdom; Swansea University Medical School, Swansea University, Swansea, United Kingdom.
| | - Catherine Lloyd
- Reconstructive Surgery and Regenerative Medicine Group, Swansea University, Swansea, United Kingdom; Centre for Nanohealth, Swansea University, Swansea, United Kingdom
| | | | - R Steven Conlan
- Centre for Nanohealth, Swansea University, Swansea, United Kingdom; Swansea University Medical School, Swansea University, Swansea, United Kingdom
| | - Iain S Whitaker
- Reconstructive Surgery and Regenerative Medicine Group, Swansea University, Swansea, United Kingdom; The Welsh Centre for Burns and Plastic Surgery, Morriston Hospital, Swansea, United Kingdom; Swansea University Medical School, Swansea University, Swansea, United Kingdom
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9
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Abstract
Pathogenic bacteria must contend with immune systems that actively restrict the availability of nutrients and cofactors, and create a hostile growth environment. To deal with these hostile environments, pathogenic bacteria have evolved or acquired virulence determinants that aid in the acquisition of nutrients. This connection between pathogenesis and nutrition may explain why regulators of metabolism in nonpathogenic bacteria are used by pathogenic bacteria to regulate both metabolism and virulence. Such coordinated regulation is presumably advantageous because it conserves carbon and energy by aligning synthesis of virulence determinants with the nutritional environment. In Gram-positive bacterial pathogens, at least three metabolite-responsive global regulators, CcpA, CodY, and Rex, have been shown to coordinate the expression of metabolism and virulence genes. In this chapter, we discuss how environmental challenges alter metabolism, the regulators that respond to this altered metabolism, and how these regulators influence the host-pathogen interaction.
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10
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Li J, Freedman JC, McClane BA. NanI Sialidase, CcpA, and CodY Work Together To Regulate Epsilon Toxin Production by Clostridium perfringens Type D Strain CN3718. J Bacteriol 2015; 197:3339-53. [PMID: 26260460 PMCID: PMC4573732 DOI: 10.1128/jb.00349-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 08/05/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Clostridium perfringens type D strains are usually associated with diseases of livestock, and their virulence requires the production of epsilon toxin (ETX). We previously showed (J. Li, S. Sayeed, S. Robertson, J. Chen, and B. A. McClane, PLoS Pathog 7:e1002429, 2011, http://dx.doi.org/10.1371/journal.ppat.1002429) that BMC202, a nanI null mutant of type D strain CN3718, produces less ETX than wild-type CN3718 does. The current study proved that the lower ETX production by strain BMC202 is due to nanI gene disruption, since both genetic and physical (NanI or sialic acid) complementation increased ETX production by BMC202. Furthermore, a sialidase inhibitor that interfered with NanI activity also reduced ETX production by wild-type CN3718. The NanI effect on ETX production was shown to involve reductions in codY and ccpA gene transcription levels in BMC202 versus wild-type CN3718. Similar to CodY, CcpA was found to positively control ETX production. A double codY ccpA null mutant produced even less ETX than a codY or ccpA single null mutant. CcpA bound directly to sequences upstream of the etx or codY start codon, and bioinformatics identified putative CcpA-binding cre sites immediately upstream of both the codY and etx start codons, suggesting possible direct CcpA regulatory effects. A ccpA mutation also decreased codY transcription, suggesting that CcpA effects on ETX production can be both direct and indirect, including effects on codY transcription. Collectively, these results suggest that NanI, CcpA, and CodY work together to regulate ETX production, with NanI-generated sialic acid from the intestines possibly signaling type D strains to upregulate their ETX production and induce disease. IMPORTANCE Clostridium perfringens NanI was previously shown to increase ETX binding to, and cytotoxicity for, MDCK host cells. The current study demonstrates that NanI also regulates ETX production via increased transcription of genes encoding the CodY and CcpA global regulators. Results obtained using single ccpA or codY null mutants and a ccpA codY double null mutant showed that codY and ccpA regulate ETX production independently of one another but that ccpA also affects codY transcription. Electrophoretic mobility shift assays and bioinformatic analyses suggest that both CodY and CcpA may directly regulate etx transcription. Collectively, results of this study suggest that sialic acid generated by NanI from intestinal sources signals ETX-producing C. perfringens strains, via CcpA and CodY, to upregulate ETX production and cause disease.
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Affiliation(s)
- Jihong Li
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - John C Freedman
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Bruce A McClane
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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Characterization of Clostridium perfringens TpeL toxin gene carriage, production, cytotoxic contributions, and trypsin sensitivity. Infect Immun 2015; 83:2369-81. [PMID: 25824828 DOI: 10.1128/iai.03136-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 03/20/2015] [Indexed: 12/14/2022] Open
Abstract
Large clostridial toxins (LCTs) are produced by at least four pathogenic clostridial species, and several LCTs are proven pivotal virulence factors for both human and veterinary diseases. TpeL is a recently identified LCT produced by Clostridium perfringens that has received relatively limited study. In response, the current study surveyed carriage of the tpeL gene among different C. perfringens strains, detecting this toxin gene in some type A, B, and C strains but not in any type D or E strains. This study also determined that all tested strains maximally produce, and extracellularly release, TpeL at the late-log or early-stationary growth stage during in vitro culture, which is different from the maximal late-stationary-phase production reported previously for other LCTs and for TpeL production by C. perfringens strain JIR12688. In addition, the present study found that TpeL levels in culture supernatants can be repressed by either glucose or sucrose. It was also shown that, at natural production levels, TpeL is a significant contributor to the cytotoxic activity of supernatants from cultures of tpeL-positive strain CN3685. Lastly, this study identified TpeL, which presumably is produced in the intestines during diseases caused by TpeL-positive type B and C strains, as a toxin whose cytotoxicity decreases after treatment with trypsin; this finding may have pathophysiologic relevance by suggesting that, like beta toxin, TpeL contributes to type B and C infections in hosts with decreased trypsin levels due to disease, diet, or age.
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12
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Roldán MV, de Oña P, Castro Y, Durán A, Faccendini P, Lagier C, Grau R, Pellegri NS. Photocatalytic and biocidal activities of novel coating systems of mesoporous and dense TiO2-anatase containing silver nanoparticles. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2014; 43:630-40. [DOI: 10.1016/j.msec.2014.07.053] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 06/13/2014] [Accepted: 07/15/2014] [Indexed: 11/29/2022]
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Carter GP, Cheung JK, Larcombe S, Lyras D. Regulation of toxin production in the pathogenic clostridia. Mol Microbiol 2013; 91:221-31. [DOI: 10.1111/mmi.12469] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Glen P. Carter
- Department of Microbiology; Monash University; Clayton Vic. 3800 Australia
| | - Jackie K. Cheung
- Department of Microbiology; Monash University; Clayton Vic. 3800 Australia
| | - Sarah Larcombe
- Department of Microbiology; Monash University; Clayton Vic. 3800 Australia
| | - Dena Lyras
- Department of Microbiology; Monash University; Clayton Vic. 3800 Australia
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Antunes A, Camiade E, Monot M, Courtois E, Barbut F, Sernova NV, Rodionov DA, Martin-Verstraete I, Dupuy B. Global transcriptional control by glucose and carbon regulator CcpA in Clostridium difficile. Nucleic Acids Res 2012; 40:10701-18. [PMID: 22989714 PMCID: PMC3510511 DOI: 10.1093/nar/gks864] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
The catabolite control protein CcpA is a pleiotropic regulator that mediates the global transcriptional response to rapidly catabolizable carbohydrates, like glucose in Gram-positive bacteria. By whole transcriptome analyses, we characterized glucose-dependent and CcpA-dependent gene regulation in Clostridium difficile. About 18% of all C. difficile genes are regulated by glucose, for which 50% depend on CcpA for regulation. The CcpA regulon comprises genes involved in sugar uptake, fermentation and amino acids metabolism, confirming the role of CcpA as a link between carbon and nitrogen pathways. Using combination of chromatin immunoprecipitation and genome sequence analysis, we detected 55 CcpA binding sites corresponding to ∼140 genes directly controlled by CcpA. We defined the C. difficile CcpA consensus binding site (creCD motif), that is, ‘RRGAAAANGTTTTCWW’. Binding of purified CcpA protein to 19 target creCD sites was demonstrated by electrophoretic mobility shift assay. CcpA also directly represses key factors in early steps of sporulation (Spo0A and SigF). Furthermore, the C. difficile toxin genes (tcdA and tcdB) and their regulators (tcdR and tcdC) are direct CcpA targets. Finally, CcpA controls a complex and extended regulatory network through the modulation of a large set of regulators.
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Affiliation(s)
- Ana Antunes
- Laboratoire Pathogenèse des Bactéries Anaérobies, Département de Microbiologie Institut Pasteur, Paris 75015, France
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