1
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Harrison B, Raju D, Garmory HS, Brett MM, Titball RW, Sarker MR. Retraction for Harrison et al., "Molecular Characterization of Clostridium perfringens Isolates from Humans with Sporadic Diarrhea: Evidence for Transcriptional Regulation of the Beta2-Toxin-Encoding Gene". Appl Environ Microbiol 2024:e0025924. [PMID: 38606962 DOI: 10.1128/aem.00259-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024] Open
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2
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Waters M, Raju D, Garmory HS, Popoff MR, Sarker MR. Retraction for Waters et al., "Regulated Expression of the Beta2-Toxin Gene ( cpb2) in Clostridium perfringens Type A Isolates from Horses with Gastrointestinal Diseases". J Clin Microbiol 2024:e0024224. [PMID: 38606970 DOI: 10.1128/jcm.00242-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024] Open
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3
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Granton E, Brown L, Defaye M, Moazen P, Almblad H, Randall TE, Rich JD, Geppert A, Abdullah NS, Hassanabad MF, Hiroki CH, Farias R, Nguyen AP, Schubert C, Lou Y, Andonegui G, Iftinca M, Raju D, Vargas MA, Howell PL, Füzesi T, Bains J, Kurrasch D, Harrison JJ, Altier C, Yipp BG. Biofilm exopolysaccharides alter sensory-neuron-mediated sickness during lung infection. Cell 2024; 187:1874-1888.e14. [PMID: 38518773 DOI: 10.1016/j.cell.2024.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 01/04/2024] [Accepted: 03/01/2024] [Indexed: 03/24/2024]
Abstract
Infections of the lung cause observable sickness thought to be secondary to inflammation. Signs of sickness are crucial to alert others via behavioral-immune responses to limit contact with contagious individuals. Gram-negative bacteria produce exopolysaccharide (EPS) that provides microbial protection; however, the impact of EPS on sickness remains uncertain. Using genome-engineered Pseudomonas aeruginosa (P. aeruginosa) strains, we compared EPS-producers versus non-producers and a virulent Escherichia coli (E. coli) lung infection model in male and female mice. EPS-negative P. aeruginosa and virulent E. coli infection caused severe sickness, behavioral alterations, inflammation, and hypothermia mediated by TLR4 detection of the exposed lipopolysaccharide (LPS) in lung TRPV1+ sensory neurons. However, inflammation did not account for sickness. Stimulation of lung nociceptors induced acute stress responses in the paraventricular hypothalamic nuclei by activating corticotropin-releasing hormone neurons responsible for sickness behavior and hypothermia. Thus, EPS-producing biofilm pathogens evade initiating a lung-brain sensory neuronal response that results in sickness.
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Affiliation(s)
- Elise Granton
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Luke Brown
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Manon Defaye
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Inflammation Research Network, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Parisa Moazen
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Henrik Almblad
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Trevor E Randall
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Jacquelyn D Rich
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Andrew Geppert
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Nasser S Abdullah
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Inflammation Research Network, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Mortaza F Hassanabad
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Carlos H Hiroki
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Raquel Farias
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Angela P Nguyen
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Courtney Schubert
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Yuefei Lou
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Graciela Andonegui
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Mircea Iftinca
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Inflammation Research Network, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Deepa Raju
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Mario A Vargas
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - P Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Tamás Füzesi
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Cumming School of Medicine Optogenetics Core Facility, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Jaideep Bains
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Krembil Research Institute, University Health Network, Toronto, ON, Canada.
| | - Deborah Kurrasch
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
| | - Joe Jonathan Harrison
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Biological Sciences, University of Calgary, Calgary, AB, Canada.
| | - Christophe Altier
- Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Inflammation Research Network, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
| | - Bryan G Yipp
- Department of Critical Care, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
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4
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Davies S, Raju D. Powerful disinfectant properties. Br Dent J 2023; 234:844. [PMID: 37349415 DOI: 10.1038/s41415-023-6035-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 04/27/2023] [Indexed: 06/24/2023]
Affiliation(s)
- S Davies
- Founder of CleanCert Hygiene, Tisbury, United Kingdom.
| | - D Raju
- Founder of Green Dentistry, Bognor Regis, United Kingdom.
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Servais L, Benguerba K, De Vivo D, Kirschner J, Muntoni F, Proud C, Tizzano E, Saito K, Raju D, LaMarca N, Sun R, Anderson F, Faulkner E, Finkel R. P.105 Safety and effectiveness of onasemnogene abeparvovec (OA) alone or with other disease-modifying therapies (DMTs): Findings from RESTORE. Neuromuscul Disord 2022. [DOI: 10.1016/j.nmd.2022.07.190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Asker D, Awad TS, Raju D, Sanchez H, Lacdao I, Gilbert S, Sivarajah P, Andes DR, Sheppard DC, Howell PL, Hatton BD. Preventing Pseudomonas aeruginosa Biofilms on Indwelling Catheters by Surface-Bound Enzymes. ACS Appl Bio Mater 2021; 4:8248-8258. [PMID: 35005941 DOI: 10.1021/acsabm.1c00794] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Implanted medical devices such as central venous catheters are highly susceptible to microbial colonization and biofilm formation and are a major risk factor for nosocomial infections. The opportunistic pathogen Pseudomonas aeruginosa uses exopolysaccharides, such as Psl, for both initial surface attachment and biofilm formation. We have previously shown that chemically immobilizing the Psl-specific glycoside hydrolase, PslGh, to a material surface can inhibit P. aeruginosa biofilm formation. Herein, we show that PslGh can be uniformly immobilized on the lumen surface of medical-grade, commercial polyethylene, polyurethane, and polydimethylsiloxane (silicone) catheter tubing. We confirmed that the surface-bound PslGh was uniformly distributed along the catheter length and remained active even after storage for 30 days at 4 °C. P. aeruginosa colonization and biofilm formation under dynamic flow culture conditions in vitro showed a 3-log reduction in the number of bacteria during the first 11 days, and a 2-log reduction by day 14 for PslGh-modified PE-100 catheters, compared to untreated catheter controls. In an in vivo rat infection model, PslGh-modified PE-100 catheters showed a ∼1.5-log reduction in the colonization of the clinical P. aeruginosa ATCC 27853 strain after 24 h. These results demonstrate the robust ability of surface-bound glycoside hydrolase enzymes to inhibit biofilm formation and their potential to reduce rates of device-associated infections.
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Affiliation(s)
- Dalal Asker
- Department of Materials Science & Engineering, University of Toronto, Toronto M5S 3E4, Canada.,Food Science & Technology Department, Alexandria University, Alexandria 21526, Egypt
| | - Tarek S Awad
- Department of Materials Science & Engineering, University of Toronto, Toronto M5S 3E4, Canada
| | - Deepa Raju
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto M5G 1X8, Canada
| | - Hiram Sanchez
- Department of Medicine, University of Wisconsin, 600 Highland Avenue, Madison 53706, Wisconsin, United States
| | - Ira Lacdao
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto M5G 1X8, Canada
| | - Stephanie Gilbert
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto M5G 1X8, Canada
| | - Piyanka Sivarajah
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto M5G 1X8, Canada
| | - David R Andes
- Department of Medicine, University of Wisconsin, 600 Highland Avenue, Madison 53706, Wisconsin, United States.,Medical Microbiology and Immunology, University of Wisconsin, Madison 53706, Wisconsin, United States
| | - Donald C Sheppard
- Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montréal H4A 3J1, Canada.,Department of Microbiology and Immunology, McGill University, Montreal H3A 0G4, Canada.,Department of Medicine, McGill University, Montreal H3A 0G4, Canada.,McGill Interdisciplinary Initiative in Infection and Immunity (MI4), Montreal H3A 0G4, Canada
| | - P Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto M5G 1X8, Canada.,Department of Biochemistry, University of Toronto, Toronto M5S 3E4, Canada
| | - Benjamin D Hatton
- Department of Materials Science & Engineering, University of Toronto, Toronto M5S 3E4, Canada
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7
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Thorn CR, Raju D, Lacdao I, Gilbert S, Sivarajah P, Howell PL, Prestidge CA, Thomas N. Protective Liquid Crystal Nanoparticles for Targeted Delivery of PslG: A Biofilm Dispersing Enzyme. ACS Infect Dis 2021; 7:2102-2115. [PMID: 33908759 DOI: 10.1021/acsinfecdis.1c00014] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The glycoside hydrolase, PslG, attacks and degrades the dominant Psl polysaccharide in the exopolymeric substance (EPS) matrix of Pseudomonas aeruginosa biofilms and is a promising therapy to potentiate the effect of antibiotics. However, the need for coadministration with an antibiotic and the potential susceptibility of PslG to proteolysis highlights the need for an effective delivery system. Here, we compared liposomes versus lipid liquid crystal nanoparticles (LCNPs) loaded with PslG and tobramycin as potential formulation approaches to (1) protect PslG from proteolysis, (2) trigger the enzyme's release in the presence of bacteria, and (3) improve the total antimicrobial effect in vitro and in vivo in a Caenorhabditis elegans infection model. LCNPs were an effective formulation strategy for PslG and tobramycin that better protected the enzyme against proteolysis, triggered and sustained the release of PslG, improved the antimicrobial effect by 10-100-fold, and increased the survival of C. elegans infected with P. aeruginosa. Digestible LCNPs had the advantage of triggering the enzyme's release in the presence of bacteria. However, compared to nondigestible LCNPs, negligible differences arose between the LCNPs' ability to protect PslG from proteolysis and potentiate the antimicrobial activity in combination with tobramycin. In C. elegans, the improved antimicrobial efficacy was comparable to tobramycin-LCNPs, although the PslG + tobramycin-LCNPs achieved a greater than 10-fold reduction in bacteria compared to the unformulated combination. Herewith, LCNPs are showcased as a promising protective delivery system for novel biofilm dispersing enzymes combined with antibiotics, enabling infection-directed therapy and improved performance.
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Affiliation(s)
- Chelsea R. Thorn
- Clinical and Health Science, University of South Australia, North Tce, Adelaide, South Australia 5000, Australia
- The Basil Hetzel Institute for Translational Health Research, Woodville, South Australia 5011, Australia
- ARC Centre for Excellence in Bio-Nano Science and Technology, Adelaide, South Australia 5000, Australia
- Biofilm Test Facility, Cancer Research Institute, University of South Australia, North Tce, Adelaide, South Australia 5000, Australia
| | - Deepa Raju
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Ira Lacdao
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Stephanie Gilbert
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Piyanka Sivarajah
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - P. Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Clive A. Prestidge
- Clinical and Health Science, University of South Australia, North Tce, Adelaide, South Australia 5000, Australia
- ARC Centre for Excellence in Bio-Nano Science and Technology, Adelaide, South Australia 5000, Australia
| | - Nicky Thomas
- Clinical and Health Science, University of South Australia, North Tce, Adelaide, South Australia 5000, Australia
- The Basil Hetzel Institute for Translational Health Research, Woodville, South Australia 5011, Australia
- ARC Centre for Excellence in Bio-Nano Science and Technology, Adelaide, South Australia 5000, Australia
- Biofilm Test Facility, Cancer Research Institute, University of South Australia, North Tce, Adelaide, South Australia 5000, Australia
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Muchintala D, Suresh V, Raju D, Sashidhar R. Synthesis and characterization of cecropin peptide-based silver nanocomposites: Its antibacterial activity and mode of action. Materials Science and Engineering: C 2020; 110:110712. [DOI: 10.1016/j.msec.2020.110712] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 01/26/2020] [Accepted: 01/30/2020] [Indexed: 12/19/2022]
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Kazmi S, Chatterjee D, Alexis K, Raju D, Wang E, Knoth R, Hauser R, Kaufman P. Real-world 1-year survival analysis of patients with metastatic breast cancer with liver or lung metastasis treated with eribulin, gemcitabine or capecitabine. Ann Oncol 2019. [DOI: 10.1093/annonc/mdz242.061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abdel-Nour M, Su H, Duncan C, Li S, Raju D, Shamoun F, Valton M, Ginevra C, Jarraud S, Guyard C, Kerman K, Terebiznik MR. Polymorphisms of a Collagen-Like Adhesin Contributes to Legionella pneumophila Adhesion, Biofilm Formation Capacity and Clinical Prevalence. Front Microbiol 2019; 10:604. [PMID: 31024468 PMCID: PMC6460258 DOI: 10.3389/fmicb.2019.00604] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 03/11/2019] [Indexed: 11/22/2022] Open
Abstract
Legionellosis is a severe respiratory illness caused by the inhalation of aerosolized water droplets contaminated with the opportunistic pathogen Legionella pneumophila. The ability of L. pneumophila to produce biofilms has been associated with its capacity to colonize and persist in human-made water reservoirs and distribution systems, which are the source of legionellosis outbreaks. Nevertheless, the factors that mediate L. pneumophila biofilm formation are largely unknown. In previous studies we reported that the adhesin Legionella collagen-like protein (Lcl), is required for auto-aggregation, attachment to multiple surfaces and the formation of biofilms. Lcl structure contains three distinguishable regions: An N-terminal region with a predicted signal sequence, a central region containing tandem collagen-like repeats (R-domain) and a C-terminal region (C-domain) with no significant homology to other known proteins. Lcl R-domain encodes tandem repeats of the collagenous tripeptide Gly-Xaa-Yaa (GXY), a motif that is key for the molecular organization of mammalian collagen and mediates the binding of collagenous proteins to different cellular and environmental ligands. Interestingly, Lcl is polymorphic in the number of GXY tandem repeats. In this study, we combined diverse biochemical, genetic, and cellular approaches to determine the role of Lcl domains and GXY repeats polymorphisms on the structural and functional properties of Lcl, as well as on bacterial attachment, aggregation and biofilm formation. Our results indicate that the R-domain is key for assembling Lcl collagenous triple-helices and has a more preponderate role over the C-domain in Lcl adhesin binding properties. We show that Lcl molecules oligomerize to form large supramolecular complexes to which both, R and C-domains are required. Furthermore, we found that the number of GXY tandem repeats encoded in Lcl R-domain correlates positively with the binding capabilities of Lcl and with the attachment and biofilm production capacity of L. pneumophila strains. Accordingly, the number of GXY tandem repeats in Lcl influences the clinical prevalence of L. pneumophila strains. Therefore, the number of Lcl tandem repeats could be considered as a potential predictor for virulence in L. pneumophila isolates.
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Affiliation(s)
- Mena Abdel-Nour
- Ontario Agency for Health Protection and Promotion, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.,The Mount Sinai Hospital, Toronto, ON, Canada
| | - Han Su
- Department of Physical & Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - Carla Duncan
- Ontario Agency for Health Protection and Promotion, Toronto, ON, Canada
| | - Shaopei Li
- Department of Physical & Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - Deepa Raju
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada.,Department of Cell and Systems Biology, University of Toronto at Scarborough, Toronto, ON, Canada
| | - Feras Shamoun
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada.,Department of Cell and Systems Biology, University of Toronto at Scarborough, Toronto, ON, Canada
| | - Marine Valton
- Ontario Agency for Health Protection and Promotion, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.,Polytech Clermont-Ferrand, Aubière, France
| | - Christophe Ginevra
- CIRI-International Center for Infectiology Research, Legionella Pathogenesis Team, Université de Lyon, Lyon, France.,INSERM U1111, Lyon, France.,Centre International de Recherche en Infectiologie, Claude Bernard University Lyon 1, Lyon, France.,National Center for Legionella, Hospices Civils de Lyon, Lyon, France
| | - Sophie Jarraud
- CIRI-International Center for Infectiology Research, Legionella Pathogenesis Team, Université de Lyon, Lyon, France.,INSERM U1111, Lyon, France.,Centre International de Recherche en Infectiologie, Claude Bernard University Lyon 1, Lyon, France.,National Center for Legionella, Hospices Civils de Lyon, Lyon, France
| | - Cyril Guyard
- Ontario Agency for Health Protection and Promotion, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.,The Mount Sinai Hospital, Toronto, ON, Canada.,BIOASTER Microbiology Technology Institute, Lyon, France
| | - Kagan Kerman
- Department of Physical & Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - Mauricio R Terebiznik
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada.,Department of Cell and Systems Biology, University of Toronto at Scarborough, Toronto, ON, Canada
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11
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Raju D, Bathini S, Badilescu S, Ouellette RJ, Ghosh A, Packirisamy M. LSPR detection of extracellular vesicles using a silver-PDMS nano-composite platform suitable for sensor networks. ENTERP INF SYST-UK 2018. [DOI: 10.1080/17517575.2018.1526326] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- D. Raju
- Department of Mechanical Industrial and Aerospace Engineering, Optical Bio Microsystems Laboratory, Concordia University, Montreal, Canada
| | - S. Bathini
- Department of Mechanical Industrial and Aerospace Engineering, Optical Bio Microsystems Laboratory, Concordia University, Montreal, Canada
| | - S. Badilescu
- Department of Mechanical Industrial and Aerospace Engineering, Optical Bio Microsystems Laboratory, Concordia University, Montreal, Canada
| | | | - A. Ghosh
- Atlantic Cancer Research Institute, Moncton, Canada
| | - M. Packirisamy
- Department of Mechanical Industrial and Aerospace Engineering, Optical Bio Microsystems Laboratory, Concordia University, Montreal, Canada
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Prashar A, Ortiz ME, Lucarelli S, Barker E, Tabatabeiyazdi Z, Shamoun F, Raju D, Antonescu C, Guyard C, Terebiznik MR. Small Rho GTPases and the Effector VipA Mediate the Invasion of Epithelial Cells by Filamentous Legionella pneumophila. Front Cell Infect Microbiol 2018; 8:133. [PMID: 29774203 PMCID: PMC5943596 DOI: 10.3389/fcimb.2018.00133] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 04/17/2018] [Indexed: 12/13/2022] Open
Abstract
Legionella pneumophila (Lp) exhibits different morphologies with varying degrees of virulence. Despite their detection in environmental sources of outbreaks and in respiratory tract secretions and lung autopsies from patients, the filamentous morphotype of Lp remains poorly studied. We previously demonstrated that filamentous Lp invades lung epithelial cells (LECs) and replicates intracellularly in a Legionella containing vacuole. Filamentous Lp activates β1integrin and E-cadherin receptors at the surface of LECs leading to the formation of actin-rich cell membrane structures we termed hooks and membrane wraps. These structures entrap segments of an Lp filament on host cell surface and mediate bacterial internalization. Here we investigated the molecular mechanisms responsible for the actin rearrangements needed for the formation and elongation of these membrane wraps and bacterial internalization. We combined genetic and pharmacological approaches to assess the contribution of signaling downstream of β1integrin and E-cadherin receptors, and Lp Dot/Icm secretion system- translocated effectors toward the invasion process. Our studies demonstrate a multi-stage mechanism of LEC invasion by filamentous Lp. Bacterial attachment to host cells depends on signaling downstream of β1integrin and E-cadherin activation, leading to Rho GTPases-dependent activation of cellular actin nucleating proteins, Arp2/3 and mDia. This mediates the formation of primordial membrane wraps that entrap the filamentous bacteria on the cell surface. Following this, in a second phase of the invasion process the Dot/Icm translocated effector VipA mediates rapid membrane wrap elongation, leading to the engulfment of the filamentous bacteria by the LECs. Our findings provide the first description of Rho GTPases and a Dot/Icm effector VipA regulating the actin dynamics needed for the invasion of epithelial cells by Lp.
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Affiliation(s)
- Akriti Prashar
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - María Eugenia Ortiz
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada
| | - Stefanie Lucarelli
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Elizabeth Barker
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Zohreh Tabatabeiyazdi
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Feras Shamoun
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada
| | - Deepa Raju
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada
| | - Costin Antonescu
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Cyril Guyard
- Bioaster, Lyon, France.,Molecular Microbiology, Public Health Ontario, Toronto, ON, Canada
| | - Mauricio R Terebiznik
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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Bathini S, Raju D, Badilescu S, Kumar A, Ouellette RJ, Ghosh A, Packirisamy M. Nano-Bio Interactions of Extracellular Vesicles with Gold Nanoislands for Early Cancer Diagnosis. Research (Wash D C) 2018; 2018:3917986. [PMID: 31549028 PMCID: PMC6750071 DOI: 10.1155/2018/3917986] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 09/19/2018] [Indexed: 12/31/2022]
Abstract
Extracellular vesicles or exosomes are membrane encapsulated biological nanometric particles secreted virtually by all types of cells throughout the animal kingdom. They carry a cargo of active molecules to proximal and distal cells of the body as mechanism of physiological communication, to maintain natural homeostasis as well as pathological responses. Exosomes carry a tremendous potential for liquid biopsy and therapeutic applications. Thus, there is a global demand for simple and robust exosome isolation methods amenable to point-of-care diagnosis and quality control of therapeutic exosome manufacturing. This can be achieved by molecular profiling of the exosomes for use with specific sets of molecular-markers for diagnosis and quality control. Liquid biopsy is undoubtedly the most promising diagnosis process to advance "personalized medicine." Currently, liquid biopsy is based on circulating cancer cells, cell free-DNA, or exosomes. Exosomes potentially provide promise for early-stage diagnostic possibility; in order to facilitate superior diagnosis and isolation of exosomes, a novel platform is developed to detect and capture them, based on localized surface plasmon resonance (LSPR) of gold nanoislands, through strong affinity between exosomes and peptide called Venceremin or Vn96. Physical modeling, based on the characteristics of the gold nanoislands and the bioentities involved in the sensing, is also developed to determine the detection capability of the platform, which is optimized experimentally at each stage. Preliminary results and modeling present a relationship between the plasmonic shift and the concentration of exosomes and, essentially, indicate possibilities for label-free early diagnosis.
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Affiliation(s)
- S. Bathini
- 1Optical Bio-Microsystems Laboratory, Department of Mechanical Industrial and Aerospace Engineering, Concordia University, Montreal, Canada
| | - D. Raju
- 1Optical Bio-Microsystems Laboratory, Department of Mechanical Industrial and Aerospace Engineering, Concordia University, Montreal, Canada
| | - S. Badilescu
- 1Optical Bio-Microsystems Laboratory, Department of Mechanical Industrial and Aerospace Engineering, Concordia University, Montreal, Canada
| | - A. Kumar
- 2Atlantic Cancer Research Institute, Moncton, New Brunswick, Canada
| | - R. J. Ouellette
- 2Atlantic Cancer Research Institute, Moncton, New Brunswick, Canada
| | - A. Ghosh
- 2Atlantic Cancer Research Institute, Moncton, New Brunswick, Canada
| | - M. Packirisamy
- 1Optical Bio-Microsystems Laboratory, Department of Mechanical Industrial and Aerospace Engineering, Concordia University, Montreal, Canada
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Shaji KS, Raju D, Sathesh V, Krishnakumar P, Punnoose VP, Kiran PS, Mini BS, Kumar S, Anish PK, Kaimal GG, Gupthan L, Sumesh TP, Nikhil UG, Cyriac N, Vinod MD, Kumar RP, Chandran R, Rejani PP, Amrutha R, Mahesh, Anand TN. Psychiatric morbidity in the community: A population based-study from Kerala. Indian J Psychiatry 2017; 59:149-156. [PMID: 28827860 PMCID: PMC5547854 DOI: 10.4103/psychiatry.indianjpsychiatry_162_17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Estimates of psychiatric morbidity in the community will help service development. Participation of trained nonspecialist health-care providers will facilitate scaling up of services in resource-limited settings. AIMS This study aimed to estimate the prevalence of priority mental health problems in populations served by the District Mental Health Program (DMHP). SETTINGS AND DESIGN This is a population-based cross-sectional survey. MATERIALS AND METHODS We did stratified cluster sampling of households in five districts of Kerala. Trained Accredited Social Health Activists (ASHAs) identified people who had symptoms suggestive of schizophrenia or bipolar disorder. Clinicians evaluated the information collected by the ASHAs and designated individuals as probable cases of psychosis or noncases. Screening instruments such as General Health Questionnaire-12, CAGE questionnaire, and Everyday Abilities Scale for India were used for identifying common mental disorders (CMDs), clinically significant alcohol-related problems, and functional impairment. RESULTS We found 12.43% of the adult population affected by mental health conditions. We found CMD as most common with a prevalence of 9%. The prevalence of psychosis was 0.71%, clinically significant alcohol-related problems was 1.46%, and dementia and other cognitive impairments was 1.26%. We found informant-based case finding to be useful in the identification of psychosis. CONCLUSIONS Mental health problems are common. Nonspecialist health-care providers can be trained to identify psychiatric morbidity in the community. Their participation will help in narrowing the treatment gap. Embedding operational research to DMHP will make scaling up more efficient.
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Affiliation(s)
- K S Shaji
- Department of Psychiatry, Government Medical College, Thrissur, Kerala, India
| | - D Raju
- Former Secretary, Kerala State Mental Health Authority and Director, IBM Hospital, Thiruvananthapuram, Kerala State Mental Health Authority, Kerala, India
| | - V Sathesh
- Department of Psychiatry, Government Medical College, Alappuzha, Kerala, India
| | - P Krishnakumar
- IMHANS, Government Medical College Campus, Kozhikode, Kerala, India
| | | | - P S Kiran
- Mental Health Programmes, Directorate of Health Services, Thiruvananthapuram, Kerala, India
| | - B S Mini
- Consultant Psychiatrist, District Hospital, Kollam, Kerala, India
| | - Shibu Kumar
- IMHANS, Government Medical College Campus, Kozhikode, Kerala, India
| | - P K Anish
- IMHANS, Government Medical College Campus, Kozhikode, Kerala, India
| | | | - Lekshmy Gupthan
- Department of Psychiatry, Government Medical College, Thrissur, Kerala, India
| | - T P Sumesh
- Department of Psychiatry, Government Medical College, Thrissur, Kerala, India
| | - U G Nikhil
- Government Medical College, Kozhikode, Kerala, India
| | - Nisha Cyriac
- Government Medical College, Kottayam, Kerala, India
| | - M D Vinod
- DMHP, Thiruvananthapuram, Kerala, India
| | | | | | - P P Rejani
- Department of Psychiatry, Government Medical College, Thrissur, Kerala, India
| | - R Amrutha
- DMHP, Thiruvananthapuram, Kerala, India
| | - Mahesh
- DMHP, Kollam, Kerala, India
| | - T N Anand
- Senior Research Fellow, Health Action by People, Thiruvananthapuram, Kerala, India
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Ivanescu AE, Li P, George B, Brown AW, Keith SW, Raju D, Allison DB. The importance of prediction model validation and assessment in obesity and nutrition research. Int J Obes (Lond) 2015; 40:887-94. [PMID: 26449421 DOI: 10.1038/ijo.2015.214] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 09/10/2015] [Accepted: 10/01/2015] [Indexed: 12/23/2022]
Abstract
Deriving statistical models to predict one variable from one or more other variables, or predictive modeling, is an important activity in obesity and nutrition research. To determine the quality of the model, it is necessary to quantify and report the predictive validity of the derived models. Conducting validation of the predictive measures provides essential information to the research community about the model. Unfortunately, many articles fail to account for the nearly inevitable reduction in predictive ability that occurs when a model derived on one data set is applied to a new data set. Under some circumstances, the predictive validity can be reduced to nearly zero. In this overview, we explain why reductions in predictive validity occur, define the metrics commonly used to estimate the predictive validity of a model (for example, coefficient of determination (R(2)), mean squared error, sensitivity, specificity, receiver operating characteristic and concordance index) and describe methods to estimate the predictive validity (for example, cross-validation, bootstrap, and adjusted and shrunken R(2)). We emphasize that methods for estimating the expected reduction in predictive ability of a model in new samples are available and this expected reduction should always be reported when new predictive models are introduced.
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Affiliation(s)
- A E Ivanescu
- Department of Mathematical Sciences, Montclair State University, Montclair, NJ, USA
| | - P Li
- Office of Energetics and Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - B George
- Office of Energetics and Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - A W Brown
- Office of Energetics and Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - S W Keith
- Division of Biostatistics, Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, PA, USA
| | - D Raju
- School of Nursing, University of Alabama at Birmingham, Birmingham, AL, USA
| | - D B Allison
- Office of Energetics and Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL, USA
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Sashidhar RB, Selvi SK, Vinod VTP, Kosuri T, Raju D, Karuna R. Bioprospecting of gum kondagogu (Cochlospermum gossypium) for bioremediation of uranium (VI) from aqueous solution and synthetic nuclear power reactor effluents. J Environ Radioact 2015; 148:33-41. [PMID: 26093855 DOI: 10.1016/j.jenvrad.2015.05.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 04/17/2015] [Accepted: 05/15/2015] [Indexed: 06/04/2023]
Abstract
An ecofriendly green chemistry method using a natural biopolymer, Gum Kondagogu (GK) for the removal of U (VI) from aqueous, simulated nuclear effluents was studied. The adsorption characteristic of GK towards U (VI) from aqueous solution was studied at varied pH, contact time, adsorbent dose, initial U (VI) concentration and temperature using UV-Visible spectroscopy and ICP-MS. Maximum adsorption was seen at pH 4, 0.1% GK with 60 min contact time at room temperature. The GK- U (VI) composite was characterized by FT-IR, zeta potential, TEM and SEM-EDAX. The Langmuir isotherm was found to be 487 mg of U (VI) g(-1) of GK. The adsorption capacity and (%) of U (VI) was found to be 490 ± 5.4 mg g(-1) and 98.5%. Moreover adsorption of U (VI) by GK was not influenced by other cations present in the simulated effluents. The adsorbed U (VI) was efficiently stripped from composite using 1 M HCl.
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Affiliation(s)
- R B Sashidhar
- Department of Biochemistry, University College of Science, Osmania University, Hyderabad 500 007, Telangana, India.
| | - S Kalaignana Selvi
- Department of Biochemistry, University College of Science, Osmania University, Hyderabad 500 007, Telangana, India
| | - V T P Vinod
- Department of Biochemistry, University College of Science, Osmania University, Hyderabad 500 007, Telangana, India
| | - Tanuja Kosuri
- Department of Biochemistry, University College of Science, Osmania University, Hyderabad 500 007, Telangana, India
| | - D Raju
- Department of Biochemistry, University College of Science, Osmania University, Hyderabad 500 007, Telangana, India
| | - R Karuna
- Department of Biochemistry, University College of Science, Osmania University, Hyderabad 500 007, Telangana, India
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Thatipamula SG, Shukla UK, Ganesh R, Saxena YC, Raju D. A simple experimental method to determine magnetic field topology in toroidal plasma devices. Rev Sci Instrum 2015; 86:033504. [PMID: 25832226 DOI: 10.1063/1.4914388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Estimation of the parallel wavenumber in plasma devices finds wide applications such as determining the nature of instabilities. This task is often challenging, especially in toroidal magnetic configurations. In the present work, a simple yet effective method of achieving accurate probe-alignment along the magnetic field lines is demonstrated in a simple magnetized toroidal device BETA (Basic Experiments in Toroidal Assembly). The alignment was achieved by aligning each probe to a tiny localized plasma source. Such an alignment is necessary for determining the parallel wavenumber precisely. The probe-alignment was confirmed further from the measurements in the plasma and the corresponding parallel wavenumber was found to be in good agreement with the analytical predictions.
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Affiliation(s)
| | - Umesh K Shukla
- Institute for Plasma Research, Gandhinagar, Gujarat 382428, India
| | - R Ganesh
- Institute for Plasma Research, Gandhinagar, Gujarat 382428, India
| | - Y C Saxena
- Institute for Plasma Research, Gandhinagar, Gujarat 382428, India
| | - D Raju
- Institute for Plasma Research, Gandhinagar, Gujarat 382428, India
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18
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Raju D, Mehta UJ, Ahmad A. Simple Recovery of Intracellular Gold Nanoparticles from Peanut Seedling Roots. J Nanosci Nanotechnol 2015; 15:1575-1581. [PMID: 26353693 DOI: 10.1166/jnn.2015.9046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Fabrication of inorganic nanomaterials via a biological route witnesses the formation either extracellularly, intracellulary or both. Whereas extracellular formation of these nanomaterials is cherished owing to their easy and economical extraction and purification processes; the intracellular formation of nanomaterials, due to the lack of a proper recovery protocol has always been dreaded, as the extraction processes used so far were tedious, costly, time consuming and often resulting in very low recovery. The aim of the present study was to overcome the problems related with the extraction and recovery of intracellularly synthesized inorganic nanoparticles, and to devise a method to increasing the output, the shape, size, composition and dispersal of nanoparticles is not altered. Water proved to be much better system as it provided well dispersed, stable gold nanoparticles and higher recovery. This is the first report, where intracellular nanoparticles have been recovered using a very cost-effective and eco-friendly approach.
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Hossain M, Fernando J, Nordeen N, Raju D, Cechic G, Raju S, Singh R. Gastrointestinal: rare and almost fatal case of upper gastrointestinal bleeding. J Gastroenterol Hepatol 2014; 29:1849. [PMID: 25392917 DOI: 10.1111/jgh.12761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Affiliation(s)
- M Hossain
- Gastroenterology Unit, Lyell McEwin Hospital, Elizabeth Vale, South Australia, Australia
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Ramtenki V, Raju D, Mehta UJ, Ramana CV, Prasad BLV. Synthesis of Ag-glyconanoparticles using C-glycosides, their lectin binding studies and antibacterial activity. NEW J CHEM 2013. [DOI: 10.1039/c3nj00496a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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23
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Raju D, Hussey S, Jones NL. Crohn disease ATG16L1 polymorphism increases susceptibility to infection with Helicobacter pylori in humans. Autophagy 2012; 8:1387-8. [PMID: 22885761 DOI: 10.4161/auto.21007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Autophagy plays key roles both in host defense against bacterial infection and in tumor biology. Helicobacter pylori (H. pylori) infection causes chronic gastritis and is the single most important risk factor for the development of gastric cancer in humans. Its vacuolating cytotoxin (VacA) promotes gastric colonization and is associated with more severe disease. Acute exposure to VacA initially triggers host autophagy to mitigate the effects of the toxin in epithelial cells. Recently, we demonstrated that chronic exposure to VacA leads to the formation of defective autophagosomes that lack CTSD/cathepsin D and have reduced catalytic activity. Disrupted autophagy results in accumulation of reactive oxygen species and SQSTM1/p62 both in vitro and in vivo in biopsy samples from patients infected with VacA(+) but not VacA(-) strains. We also determined that the Crohn disease susceptibility polymorphism in the essential autophagy gene ATG16L1 increases susceptibility to H. pylori infection. Furthermore, peripheral blood monocytes from individuals with the ATG16L1 risk variant show impaired autophagic responses to VacA exposure. This is the first study to identify both a host autophagy susceptibility gene for H. pylori infection and to define the mechanism by which the autophagy pathway is affected following H. pylori infection. Collectively, these findings highlight the synergistic effects of host and bacterial autophagy factors on H. pylori pathogenesis and the potential for subsequent cancer susceptibility.
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Affiliation(s)
- Deepa Raju
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
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24
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Raju D, Hussey S, Ang M, Terebiznik M, Sibony M, Galindo-Mata E, Gupta V, Blanke S, Delgado A, Romero-Gallo J, Ramjeet M, Mascarenhas H, Peek R, Correa P, Streutker C, Hold G, Kunstmann E, Yoshimori T, Silverberg MS, Girardin S, Philpott D, El Omar E, Jones N. Vacuolating cytotoxin and variants in Atg16L1 that disrupt autophagy promote Helicobacter pylori infection in humans. Gastroenterology 2012; 142:1160-71. [PMID: 22333951 PMCID: PMC3336037 DOI: 10.1053/j.gastro.2012.01.043] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 01/03/2012] [Accepted: 01/26/2012] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS The Helicobacter pylori toxin vacuolating cytotoxin (VacA) promotes gastric colonization, and its presence (VacA(+)) is associated with more-severe disease. The exact mechanisms by which VacA contributes to infection are unclear. We previously found that limited exposure to VacA induces autophagy of gastric cells, which eliminates the toxin; we investigated whether autophagy serves as a defense mechanism against H pylori infection. METHODS We investigated the effect of VacA on autophagy in human gastric epithelial cells and primary gastric cells from mice. Expression of p62, a marker of autophagy, was also assessed in gastric tissues from patients infected with toxigenic (VacA(+)) or nontoxigenic strains. We analyzed the effect of VacA on autophagy in peripheral blood monocytes obtained from subjects with different genotypes of ATG16L1, which regulates autophagy. We performed genotyping for ATG16L1 in 2 cohorts of infected and uninfected subjects. RESULTS Prolonged exposure of human gastric epithelial cells and mouse gastric cells to VacA disrupted induction of autophagy in response to the toxin, because the cells lacked cathepsin D in autophagosomes. Loss of autophagy resulted in the accumulation of p62 and reactive oxygen species. Gastric biopsy samples from patients infected with VacA(+), but not nontoxigenic strains of H pylori, had increased levels of p62. Peripheral blood monocytes isolated from individuals with polymorphisms in ATG16L1 that increase susceptibility to Crohn's disease had reduced induction of autophagy in response to VacA(+) compared to cells from individuals that did not have these polymorphisms. The presence of the ATG16L1 Crohn's disease risk variant increased susceptibility to H pylori infection in 2 separate cohorts. CONCLUSIONS Autophagy protects against infection with H pylori; the toxin VacA disrupts autophagy to promote infection, which could contribute to inflammation and eventual carcinogenesis.
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Affiliation(s)
- D Raju
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada, Departments of Paediatrics and Physiology, University of Toronto, Toronto, ON, Canada
| | - S Hussey
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada, Departments of Paediatrics and Physiology, University of Toronto, Toronto, ON, Canada,Department of Immunology, University of Toronto, Toronto, ON Canada
| | - M Ang
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada, Departments of Paediatrics and Physiology, University of Toronto, Toronto, ON, Canada
| | - M.R. Terebiznik
- Department of Cell and Systems Biology, University of Toronto, Scarborough, ON, Canada
| | - M Sibony
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada, Departments of Paediatrics and Physiology, University of Toronto, Toronto, ON, Canada,Zane Cohen Centre for Digestive Diseases, IBD group, Mount Sinai Hospital, Toronto, ON
| | - E Galindo-Mata
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada, Departments of Paediatrics and Physiology, University of Toronto, Toronto, ON, Canada
| | - V Gupta
- Department of Microbiology and Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - S.R. Blanke
- Department of Microbiology and Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - A Delgado
- Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Centre, Nashville, TN
| | - J Romero-Gallo
- Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Centre, Nashville, TN
| | - M Ramjeet
- Department of Laboratory Medicine and Pathobiology, and the Li Ka Shing Knowledge Institute University of Toronto, Toronto, ON
| | - H Mascarenhas
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada, Departments of Paediatrics and Physiology, University of Toronto, Toronto, ON, Canada,Department of Immunology, University of Toronto, Toronto, ON Canada
| | - R.M. Peek
- Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Centre, Nashville, TN
| | - P Correa
- Division of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Centre, Nashville, TN
| | - C Streutker
- Department of Laboratory Medicine, St. Michaels’s Hospital, Toronto, ON
| | - G Hold
- Institute of Medical Sciences, School of Medicine and Dentistry, Aberdeen University, Foresterhill, Aberdeen
| | - E Kunstmann
- Praxis fur Humangenetik, Theodore-Boveri-Weg, University Wuerzburg, Germany
| | - T Yoshimori
- Department of Cellular Regulation, Research institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - M. S. Silverberg
- Zane Cohen Centre for Digestive Diseases, IBD group, Mount Sinai Hospital, Toronto, ON
| | - S.E. Girardin
- Department of Laboratory Medicine and Pathobiology, and the Li Ka Shing Knowledge Institute University of Toronto, Toronto, ON
| | - D.J. Philpott
- Department of Immunology, University of Toronto, Toronto, ON Canada
| | - E El Omar
- Institute of Medical Sciences, School of Medicine and Dentistry, Aberdeen University, Foresterhill, Aberdeen
| | - N.L. Jones
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada, Departments of Paediatrics and Physiology, University of Toronto, Toronto, ON, Canada,Corresponding Author Dr. Nicola Jones, Departments of Paediatrics and Physiology, University of Toronto, Cell Biology Program, Hospital for Sick Children, 555, University Avenue, Toronto, ON M5G1X8, Phone no: 416-813-7072,
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Kate MP, Raju D, Vishwanathan V, Khan FR, Nair, Thomas SV. Successful treatment of refractory organic catatonic disorder with repetitive transcranial magnetic stimulation (rTMS) therapy. J Neuropsychiatry Clin Neurosci 2012; 23:E2-3. [PMID: 21948910 DOI: 10.1176/jnp.23.3.jnpe2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Adherence and internalization of Helicobacter pylori into epithelial cells is a recently recognized event in the pathogen's life cycle.
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Affiliation(s)
- Deepa Raju
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
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27
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Abstract
Helicobacter pylori CagA and VacA are two critical virulence factors that modulate disease severity in the infected host. The following chapter outlines methods employed to study the effects of these virulence factors on several key signaling pathways in epithelial cells.
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Affiliation(s)
- Deepa Raju
- Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
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Smith Y, Villalba R, Pare JF, Raju D. O.065 Ultrastructural plasticity of corticostriatal and thalamostriatal glutamatergic synapses in Parkinson's disease. Parkinsonism Relat Disord 2009. [DOI: 10.1016/s1353-8020(09)70080-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Smith Y, Villalba R, Raju D, Pare JF. P3.142 Synaptic plasticity of corticostriatal and thalamostriatal systems in Parkinson's disease. Parkinsonism Relat Disord 2009. [DOI: 10.1016/s1353-8020(09)70706-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Terebiznik MR, Raju D, Vázquez CL, Torbricki K, Kulkarni R, Blanke SR, Yoshimori T, Colombo MI, Jones NL. Effect of Helicobacter pylori's vacuolating cytotoxin on the autophagy pathway in gastric epithelial cells. Autophagy 2009; 5:370-9. [PMID: 19164948 DOI: 10.4161/auto.5.3.7663] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Host cell responses to Helicobacter pylori infection are complex and incompletely understood. Here, we report that autophagy is induced within human-derived gastric epithelial cells (AGS) in response to H. pylori infection. These autophagosomes were distinct and different from the large vacuoles induced during H. pylori infection. Autophagosomes were detected by transmission electron microscopy, conversion of LC3-I to LC3-II, GFP-LC3 recruitment to autophagosomes, and depended on Atg5 and Atg12. The induction of autophagy depended on the vacuolating cytotoxin (VacA) and, moreover, VacA was sufficient to induce autophagosome formation. The channel-forming activity of VacA was necessary for inducing autophagy. Intracellular VacA partially co-localized with GFP-LC3, indicating that the toxin associates with autophagosomes. The inhibition of autophagy increased the stability of intracellular VacA, which in turn resulted in enhanced toxin-mediated cellular vacuolation. These findings suggest that the induction of autophagy by VacA may represent a host mechanism to limit toxin-induced cellular damage.
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Affiliation(s)
- Mauricio R Terebiznik
- Cell Biology Program, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada
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31
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Paredes-Sabja D, Raju D, Torres JA, Sarker MR. Role of small, acid-soluble spore proteins in the resistance of Clostridium perfringens spores to chemicals. Int J Food Microbiol 2008; 122:333-5. [DOI: 10.1016/j.ijfoodmicro.2007.12.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 12/16/2007] [Indexed: 11/17/2022]
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Raju D, Sarker MR. Production of small, acid-soluble spore proteins in Clostridium perfringens nonfoodborne gastrointestinal disease isolates. Can J Microbiol 2007; 53:514-8. [PMID: 17612607 DOI: 10.1139/w07-016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The molecular basis for the differences in heat resistance between spores of Clostridium perfringens food-borne versus nonfoodborne isolates remains unknown. Since a recent study demonstrated the role of small, acid-soluble spore proteins (SASPs) in heat resistance of spores of food-borne isolates, in the current study, we evaluated the expression of SASP-encoding genes (ssp) and the production of SASPs in nonfoodborne isolates. Our results demonstrated the presence of all three ssp genes in five surveyed nonfoodborne isolates. A beta-glucuronidase assay showed that these ssp genes are expressed specifically during sporulation. Furthermore, nonfoodborne isolate F4969 produced SASPs at a level similar to that of food-borne isolate SM101. Collectively, these results suggest that the difference in the levels of heat resistance between spores of food-borne and the nonfoodborne isolates is not the result of impaired expression of ssp genes and (or) decreased production of SASPs in nonfoodborne isolates.
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Affiliation(s)
- Deepa Raju
- Department of Biomedical Sciences, College of Veterinary Medicine and Department of Microbiology, College of Science, Oregon State University, Corvallis, OR 97331, USA
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Raju D, Setlow P, Sarker MR. Antisense-RNA-mediated decreased synthesis of small, acid-soluble spore proteins leads to decreased resistance of clostridium perfringens spores to moist heat and UV radiation. Appl Environ Microbiol 2007; 73:2048-53. [PMID: 17259355 PMCID: PMC1855649 DOI: 10.1128/aem.02500-06] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previous work has suggested that a group of alpha/beta-type small, acid-soluble spore proteins (SASP) is involved in the resistance of Clostridium perfringens spores to moist heat. However, this suggestion is based on the analysis of C. perfringens spores lacking only one of the three genes encoding alpha/beta-type SASP in this organism. We have now used antisense RNA to decrease levels of alpha/beta-type SASP in C. perfringens spores by approximately 90%. These spores had significantly reduced resistance to both moist heat and UV radiation but not to dry heat. These results clearly demonstrate the important role of alpha/beta-type SASP in the resistance of C. perfringens spores.
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Affiliation(s)
- Deepa Raju
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon 97331, USA
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Mahajan K, Ravikiran M, Gulati H, Dave H, Kumar N, Patel K, Kumar A, Raju D, Bhandarkar M, Chudasama H, Kulkarni S, Saxena Y. CORBA-based solution for remote participation in SST-1 tokamak control and operation. Fusion Engineering and Design 2006. [DOI: 10.1016/j.fusengdes.2006.04.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Raju D, Waters M, Setlow P, Sarker MR. Investigating the role of small, acid-soluble spore proteins (SASPs) in the resistance of Clostridium perfringens spores to heat. BMC Microbiol 2006; 6:50. [PMID: 16759397 PMCID: PMC1501028 DOI: 10.1186/1471-2180-6-50] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Accepted: 06/08/2006] [Indexed: 11/24/2022] Open
Abstract
Background Clostridium perfringens type A food poisoning is caused by enterotoxigenic C. perfringens type A isolates that typically possess high spore heat-resistance. The molecular basis for C. perfringens spore heat-resistance remains unknown. In the current study, we investigated the role of small, acid-soluble spore proteins (SASPs) in heat-resistance of spores produced by C. perfringens food poisoning isolates. Results Our current study demonstrated the presence of all three SASP-encoding genes (ssp1, 2 and 3) in five surveyed C. perfringens clinical food poisoning isolates. β-Glucuronidase assay showed that these ssp genes are expressed specifically during sporulation. Consistent with these expression results, our study also demonstrated the production of SASPs by C. perfringens food poisoning isolates. When the heat sensitivities of spores produced by a ssp3 knock-out mutant of a C. perfringens food poisoning isolate was compared with that of spores of the wild-type strain, spores of the ssp3 mutant were found to exhibit a lower decimal reduction value (D value) at 100°C than exhibited by the spores of wild-type strain. This effect was restored by complementing the ssp3 mutant with a recombinant plasmid carrying wild-type ssp3, suggesting that the observed differences in D values between spores of wild-type versus ssp3 mutant was due to the specific inactivation of ssp3. Furthermore, our DNA protection assay demonstrated that C. perfringens SASPs can protect DNA from DNase I digestion. Conclusion The results from our current study provide evidences that SASPs produced by C. perfringens food poisoning isolates play a role in protecting their spores from heat-damage, which is highly significant and relevant from a food safety perspective. Further detailed studies on mechanism of action of SASPs from C. perfringens should help in understanding the mechanism of protection of C. perfringens spores from heat-damage.
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Affiliation(s)
- Deepa Raju
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon 97331, USA
- Department of Microbiology, College of Science, Oregon State University, Corvallis, Oregon 97331, USA
| | - Michael Waters
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon 97331, USA
- Department of Microbiology, College of Science, Oregon State University, Corvallis, Oregon 97331, USA
| | - Peter Setlow
- Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Mahfuzur R Sarker
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon 97331, USA
- Department of Microbiology, College of Science, Oregon State University, Corvallis, Oregon 97331, USA
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Raju D, Sarker MR. Comparison of the levels of heat resistance of wild-type, cpe knockout, and cpe plasmid-cured Clostridium perfringens type A strains. Appl Environ Microbiol 2005; 71:7618-20. [PMID: 16269817 PMCID: PMC1287616 DOI: 10.1128/aem.71.11.7618-7620.2005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An enterotoxin (cpe) plasmid was cured from a Clostridium perfringens non-food-borne gastrointestinal disease (NFBGID) isolate, and the heat resistance levels of wild-type, cpe knockout, and cpe plasmid-cured strains were compared. Our results demonstrated that (i) wild-type cpe has no influence in mediating high-level heat resistance in C. perfringens and (ii) the cpe plasmid does not confer heat sensitivity on NFBGID isolates.
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Affiliation(s)
- Deepa Raju
- Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA
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Harrison B, Raju D, Garmory HS, Brett MM, Titball RW, Sarker MR. Molecular characterization of Clostridium perfringens isolates from humans with sporadic diarrhea: evidence for transcriptional regulation of the beta2-toxin-encoding gene. Appl Environ Microbiol 2005; 71:8362-70. [PMID: 16332823 PMCID: PMC1317393 DOI: 10.1128/aem.71.12.8362-8370.2005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2005] [Accepted: 09/06/2005] [Indexed: 11/20/2022] Open
Abstract
Clostridium perfringens type A food poisoning is caused by C. perfringens isolates carrying a chromosomal enterotoxin gene (cpe), while non-food-borne gastrointestinal (GI) diseases, such as antibiotic-associated diarrhea (AAD) and sporadic diarrhea (SD), are caused by C. perfringens plasmid cpe isolates. A recent study reported the association of beta2 toxin (CPB2) with human GI diseases, and particularly AAD/SD, by demonstrating that a large percentage of AAD/SD isolates, in contrast to a small percentage of food poisoning isolates, carry the beta2-toxin gene (cpb2). This putative relationship was further tested in the current study by characterizing 14 cpe+ C. perfringens fecal isolates associated with recent cases of human SD in England (referred to hereafter as SD isolates). These SD isolates were all classified as cpe+ type A, and 12 of the 14 cpe+ isolates carry their cpe gene on the plasmid and 2 carry it on the chromosome. Interestingly, cpb2 is present in only 12 plasmid cpe isolates; 11 isolates carry cpe and cpb2 on different plasmids, but cpe and cpb2 are located on the same plasmid in one isolate. C. perfringens enterotoxin is produced by all 14 cpe+ SD isolates. However, only 10 of the 12 cpe+/cpb2+ SD isolates produced CPB2, with significant variation in amounts. The levels of cpb2 mRNA in low- to high-CPB2-producing SD isolates differed to such an extent (30-fold) that this difference could be considered a major cause of the differential level of CPB2 production in vitro by SD isolates. Furthermore, no silent or atypical cpb2 was found in a CPB2 Western blot-negative isolate, 5422/94, suggesting that the lack of CPB2 production in 5422/94 was due to low expression of cpb2 mRNA. This received support from our observation that the recombinant plasmid carrying 5422/94 cpb2, which overexpressed cpb2 mRNA, restored CPB2 production in F4969 (a cpb2-negative isolate). Collectively, our present results suggest that CPB2 merits further study as an accessory toxin in C. perfringens-associated SD.
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Affiliation(s)
- Ben Harrison
- Department of Microbiology, Oregon State University, 220 Nash Hall, Corvallis, OR 97331, USA
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Waters M, Raju D, Garmory HS, Popoff MR, Sarker MR. Regulated expression of the beta2-toxin gene (cpb2) in Clostridium perfringens type a isolates from horses with gastrointestinal diseases. J Clin Microbiol 2005; 43:4002-9. [PMID: 16081942 PMCID: PMC1233996 DOI: 10.1128/jcm.43.8.4002-4009.2005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2004] [Revised: 03/13/2005] [Accepted: 05/02/2005] [Indexed: 11/20/2022] Open
Abstract
Recent epidemiological studies suggested that cpb2-positive Clostridium perfringens isolates are associated with gastrointestinal (GI) diseases in horses. These putative relationships, indicated by PCR genotyping, were tested in the present study by further genotyping and phenotyping of 23 cpb2-positive C. perfringens isolates from horses with GI disease (referred to hereafter as horse GI disease isolates). Our beta2-toxin (CPB2) Western blot analyses demonstrated that all of the tested isolates were unable to produce detectable levels of CPB2. However, Southern blot and nucleotide sequencing analyses identified intact cpb2 open reading frames in all of our surveyed horse GI disease isolates. Furthermore, reverse transcriptase PCR and Northern blot analyses showed that cpb2 genes in all of our surveyed horse GI disease isolates were transcriptionally active, i.e., an approximately 1.2-kb cpb2-specific mRNA was identified in total RNA from our surveyed isolates. The levels of cpb2 mRNA in CWC245 (a high-CPB2-producing pig strain) and our surveyed horse GI disease isolates differed to such an extent (35-fold) that this difference could be considered as a major cause of the difference in levels of CPB2 production by CWC245 and horse GI disease isolates. This finding received further support from our observation that the complementing strain 106902(pMRS140), which produced significantly higher levels of mRNA than strain 106902, produced high levels of CPB2. Collectively, our results indicated that there is a positive correlation between cpb2 transcription levels and the amount of CPB2 produced by a C. perfringens cell and that decreased transcription and/or message instability may be involved, at least in part, in the low CPB2 production noted for horse GI disease isolates in comparison to that noted for pig GI disease isolate CWC245.
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Affiliation(s)
- Michael Waters
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, Department of Biomedical Sciences, Defense Science and Technology Laboratory, Porton Down, Salisbury, SP4 0JQ, United Kingdom, Unite des Toxines Microbiennes, Institut Pasteur, 75724 Paris, Cedex 15, France
| | - Deepa Raju
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, Department of Biomedical Sciences, Defense Science and Technology Laboratory, Porton Down, Salisbury, SP4 0JQ, United Kingdom, Unite des Toxines Microbiennes, Institut Pasteur, 75724 Paris, Cedex 15, France
| | - Helen S. Garmory
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, Department of Biomedical Sciences, Defense Science and Technology Laboratory, Porton Down, Salisbury, SP4 0JQ, United Kingdom, Unite des Toxines Microbiennes, Institut Pasteur, 75724 Paris, Cedex 15, France
| | - Michel R. Popoff
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, Department of Biomedical Sciences, Defense Science and Technology Laboratory, Porton Down, Salisbury, SP4 0JQ, United Kingdom, Unite des Toxines Microbiennes, Institut Pasteur, 75724 Paris, Cedex 15, France
| | - Mahfuzur R. Sarker
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, Department of Biomedical Sciences, Defense Science and Technology Laboratory, Porton Down, Salisbury, SP4 0JQ, United Kingdom, Unite des Toxines Microbiennes, Institut Pasteur, 75724 Paris, Cedex 15, France
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Lukash V, Raju D, Dokouka V, Favez JY, Khayrutdinov R, Lister J. DINA simulations of TCV electron cyclotron heating discharges. Fusion Engineering and Design 2003. [DOI: 10.1016/s0920-3796(03)00305-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Raju D, Mathew T, Kathirvel H, Vijayalekshmy N, Abhayambika K. Herpes zoster associated encephalitis. J Assoc Physicians India 1992; 40:201-3. [PMID: 1634491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Herpes zoster associated encephalitis is a very rare complication of herpes zoster. We are reporting a young healthy man who developed this complication along with the usual cutaneous presentation of herpes zoster. He was successfully treated with acyclovir.
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Affiliation(s)
- D Raju
- Department of Medicine, Medical College Trivandrum
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Krishnamoorthy RV, Raju D, Chandrasekharam V. Demonstration of increased in vitro autolytic activity in a denervated muscle of frog. Experientia 1971; 27:1408-9. [PMID: 5144843 DOI: 10.1007/bf02154258] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Abstract
Clostridium perfringens are Gram-positive, endospore-forming, anaerobic bacteria with the ability to cause enteric diseases both in human and domesticated animals. As one of the leading cause of food-borne illness in the United States, certain C. perfringens type A isolates exert their action through the production of C. perfringens enterotoxin (CPE), which is expressed only during spore formation. In addition, C. perfringens spores are highly resistant to heat and other environmental factors. Since genome sequences of three C. perfringens strains have been annotated and made public, efforts have been made towards understanding the initiation of sporulation and identifying the key differences between Clostridium and Bacillus sporulation phosphorelay. Small, acid soluble spore proteins (SASPs) have been shown to be required for resistance of C. perfringens spores to heat. Work is also underway to identify nutrient signals required for C. perfringens spore germination. Keywords: Clostridium perfringens, Endospore, Small, acid soluble spore protein (SASP), Heat resistance, GerminationDOI: http://dx.doi.org/10.3329/bjm.v24i1.1229 Bangladesh J Microbiol, Volume 24, Number 1, June 2007, pp 1-8
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