1
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Dharmaraj T, Kratochvil MJ, Pourtois JD, Chen Q, Hajfathalian M, Hargil A, Lin YH, Evans Z, Oromí-Bosch A, Berry JD, McBride R, Haddock NL, Holman DR, van Belleghem JD, Chang TH, Barr JJ, Lavigne R, Heilshorn SC, Blankenberg FG, Bollyky PL. Rapid assessment of changes in phage bioactivity using dynamic light scattering. PNAS NEXUS 2023; 2:pgad406. [PMID: 38111822 PMCID: PMC10726995 DOI: 10.1093/pnasnexus/pgad406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 11/02/2023] [Indexed: 12/20/2023]
Abstract
Extensive efforts are underway to develop bacteriophages as therapies against antibiotic-resistant bacteria. However, these efforts are confounded by the instability of phage preparations and a lack of suitable tools to assess active phage concentrations over time. In this study, we use dynamic light scattering (DLS) to measure changes in phage physical state in response to environmental factors and time, finding that phages tend to decay and form aggregates and that the degree of aggregation can be used to predict phage bioactivity. We then use DLS to optimize phage storage conditions for phages from human clinical trials, predict bioactivity in 50-y-old archival stocks, and evaluate phage samples for use in a phage therapy/wound infection model. We also provide a web application (Phage-Estimator of Lytic Function) to facilitate DLS studies of phages. We conclude that DLS provides a rapid, convenient, and nondestructive tool for quality control of phage preparations in academic and commercial settings.
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Affiliation(s)
- Tejas Dharmaraj
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center for Molecular and Genetic Medicine, Stanford, CA 94305, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA 94305, USA
| | - Michael J Kratochvil
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Julie D Pourtois
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - Qingquan Chen
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center for Molecular and Genetic Medicine, Stanford, CA 94305, USA
| | - Maryam Hajfathalian
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center for Molecular and Genetic Medicine, Stanford, CA 94305, USA
| | - Aviv Hargil
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center for Molecular and Genetic Medicine, Stanford, CA 94305, USA
| | - Yung-Hao Lin
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Zoe Evans
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center for Molecular and Genetic Medicine, Stanford, CA 94305, USA
| | | | - Joel D Berry
- Felix Biotechnology, South SanFrancisco, CA 94080, USA
| | | | - Naomi L Haddock
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center for Molecular and Genetic Medicine, Stanford, CA 94305, USA
| | - Derek R Holman
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jonas D van Belleghem
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center for Molecular and Genetic Medicine, Stanford, CA 94305, USA
| | - Tony H Chang
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center for Molecular and Genetic Medicine, Stanford, CA 94305, USA
| | - Jeremy J Barr
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Rob Lavigne
- Department of Biosystems, KU Leuven, Leuven 3001, Belgium
| | - Sarah C Heilshorn
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Francis G Blankenberg
- Division of Pediatric Radiology and Nuclear Medicine, Department of Radiology, Lucile Packard Children's Hospital, Stanford, CA 94305, USA
| | - Paul L Bollyky
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Beckman Center for Molecular and Genetic Medicine, Stanford, CA 94305, USA
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2
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Brooks R, Morici L, Sandoval N. Cell Free Bacteriophage Synthesis from Engineered Strains Improves Yield. ACS Synth Biol 2023; 12:2418-2431. [PMID: 37548960 PMCID: PMC10443043 DOI: 10.1021/acssynbio.3c00239] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Indexed: 08/08/2023]
Abstract
Phage therapy to treat life-threatening drug-resistant infections has been hampered by technical challenges in phage production. Cell-free bacteriophage synthesis (CFBS) can overcome the limitations of standard phage production methods by manufacturing phage virions in vitro. CFBS mimics intracellular phage assembly using transcription/translation machinery (TXTL) harvested from bacterial lysates and combined with reagents to synthesize proteins encoded by a phage genomic DNA template. These systems may enable rapid phage production and engineering to accelerate phages from bench-to-bedside. TXTL harvested from wild type or commonly used bacterial strains was not optimized for bacteriophage production. Here, we demonstrate that TXTL from genetically modified E. coli BL21 can be used to enhance phage T7 yields in vitro by CFBS. Expression of 18 E. coli BL21 genes was manipulated by inducible CRISPR interference (CRISPRi) mediated by nuclease deficient Cas12a from F. novicida (dFnCas12a) to identify genes implicated in T7 propagation as positive or negative effectors. Genes shown to have a significant effect were overexpressed (positive effectors) or repressed (negative effectors) to modify the genetic background of TXTL harvested for CFBS. Phage T7 CFBS yields were improved by up to 10-fold in vitro through overexpression of translation initiation factor IF-3 (infC) and small RNAs OxyS and CyaR and by repression of RecC subunit exonuclease RecBCD. Continued improvement of CFBS will mitigate phage manufacturing bottlenecks and lower hurdles to widespread adoption of phage therapy.
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Affiliation(s)
- Rani Brooks
- Interdisciplinary
Bioinnovation PhD Program, Tulane University, New Orleans, Louisiana 70118-5665, United
States
| | - Lisa Morici
- Department
of Microbiology and Immunology, Tulane University
School of Medicine, New Orleans, Louisiana 70112, United States
| | - Nicholas Sandoval
- Department
of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118, United States
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3
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Dharmaraj T, Kratochvil MJ, Pourtois JD, Chen Q, Hajfathalian M, Hargil A, Lin YH, Evans Z, Oromí-Bosch A, Berry JD, McBride R, Haddock NL, Holman DR, van Belleghem JD, Chang TH, Barr JJ, Lavigne R, Heilshorn SC, Blankenberg FG, Bollyky PL. Rapid assessment of changes in phage bioactivity using dynamic light scattering. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.02.547396. [PMID: 37425882 PMCID: PMC10327207 DOI: 10.1101/2023.07.02.547396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Extensive efforts are underway to develop bacteriophages as therapies against antibiotic-resistant bacteria. However, these efforts are confounded by the instability of phage preparations and a lack of suitable tools to assess active phage concentrations over time. Here, we use Dynamic Light Scattering (DLS) to measure changes in phage physical state in response to environmental factors and time, finding that phages tend to decay and form aggregates and that the degree of aggregation can be used to predict phage bioactivity. We then use DLS to optimize phage storage conditions for phages from human clinical trials, predict bioactivity in 50-year-old archival stocks, and evaluate phage samples for use in a phage therapy/wound infection model. We also provide a web-application (Phage-ELF) to facilitate DLS studies of phages. We conclude that DLS provides a rapid, convenient, and non-destructive tool for quality control of phage preparations in academic and commercial settings.
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Affiliation(s)
- Tejas Dharmaraj
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA 94305, USA
| | - Michael J. Kratochvil
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305
| | - Julie D. Pourtois
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 93950, USA
| | - Qingquan Chen
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Maryam Hajfathalian
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Aviv Hargil
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yung-Hao Lin
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Zoe Evans
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | | | | | | | - Naomi L. Haddock
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Derek R. Holman
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jonas D. van Belleghem
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Tony H. Chang
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jeremy J. Barr
- School of Biological Sciences, Monash University, Clayton, 3800, VIC, Australia
| | - Rob Lavigne
- Department of Biosystems, KU Leuven, Leuven, 3001, Belgium
| | - Sarah C. Heilshorn
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305
| | - Francis G. Blankenberg
- Division of Pediatric Radiology and Nuclear Medicine, Department of Radiology, Lucile Packard Children’s Hospital, Stanford, CA 94305, USA
| | - Paul L. Bollyky
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
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Affonso de Oliveira JF, Chan SK, Omole AO, Agrawal V, Steinmetz NF. In Vivo Fate of Cowpea Mosaic Virus In Situ Vaccine: Biodistribution and Clearance. ACS NANO 2022; 16:18315-18328. [PMID: 36264973 PMCID: PMC9840517 DOI: 10.1021/acsnano.2c06143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Cowpea mosaic virus (CPMV) is a nucleoprotein nanoparticle that functions as a highly potent immunomodulator when administered intratumorally and is used as an in situ vaccine. CPMV in situ vaccination remodels the tumor microenvironment and primes a highly potent, systemic, and durable antitumor immune response against the treated and untreated, distant metastatic sites (abscopal effect). Potent efficacy was demonstrated in multiple tumor mouse models and, most importantly, in canine cancer patients with spontaneous tumors. Data indicate that presence of anti-CPMV antibodies are not neutralizing and that in fact opsonization leads to enhanced efficacy. Plant viruses are part of the food chain, but to date, there is no information on human exposure to CPMV. Therefore, patient sera were tested for the presence of immunoglobulins against CPMV, and indeed, >50% of deidentified patient samples tested positive for CPMV antibodies. To get a broader sense of plant virus exposure and immunogenicity in humans, we also tested sera for antibodies against tobacco mosaic virus (>90% patients tested positive), potato virus X (<20% patients tested positive), and cowpea chlorotic mottle virus (no antibodies were detected). Further, patient sera were analyzed for the presence of antibodies against the coliphage Qβ, a platform technology currently undergoing clinical trials for in situ vaccination; we found that 60% of patients present with anti-Qβ antibodies. Thus, data indicate human exposure to CPMV and other plant viruses and phages. Next, we thought to address agronomical safety; i.e., we examined the fate of CPMV after intratumoral treatment and oral gavage (to mimic consumption by food). Because live CPMV is used, an important question is whether there is any evidence of shedding of infectious particles from mice or patients. CPMV is noninfectious toward mammals; however, it is infectious toward plants including black-eyed peas and other legumes. Biodistribution data in tumor-bearing and healthy mice indicate little leaching from tumors and clearance via the reticuloendothelial system followed by biliary excretion. While there was evidence of shedding of RNA in stool, there was no evidence of infectious particles when plants were challenged with stool extracts, thus indicating agronomical safety. Together these data aid the translational development of CPMV as a drug candidate for cancer immunotherapy.
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Affiliation(s)
| | - Soo Khim Chan
- Department of NanoEngineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92039, United States
| | - Anthony O Omole
- Department of NanoEngineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92039, United States
| | - Vanshika Agrawal
- Department of NanoEngineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92039, United States
| | - Nicole F Steinmetz
- Department of NanoEngineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92039, United States
- Center for Nano-ImmunoEngineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92039, United States
- Department of Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92039, United States
- Department of Radiology, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92039, United States
- Moores Cancer Center, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92039, United States
- Institute for Materials Discovery and Design, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92039, United States
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5
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The Effect of Spray Parameters on the Survival of Bacteriophages. Processes (Basel) 2022. [DOI: 10.3390/pr10040673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
There have been numerous studies highlighting the efficacy of various bacteriophages (phages) and phage cocktails in the reduction of pathogens in food. Despite approval from legislative bodies permitting phage use in food processing environments, applied via spray or dip, there is still no information on which spray parameters should be used for successful implementation. The study here investigates phage survival diluted to 1% in distilled water (dH2O) and prepared bottled water (PBW), followed by a subsequent spray application through a fixed nozzle (530 μm) and strainer size (74 × 74 μm), with pressures of 3, 5, and 6 Bar. The survival of the phage was determined through sampling the outputs of the spray system and performing double agar overlay plaque assays. PBW decreased the phage concentration (p = 0.18) more than the dH2O (p = 0.73) prior to spray application. It was found that the PBW phage solution was less affected by the various spray parameters (p = 0.045) than the dH2O (p = 0.011). The study showed that unchlorinated water (dH2O), as well as a pressure of 3 Bar, had the highest output phage concentration through the nozzle and strainer, providing valuable information for industrial implementation.
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6
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Hutchinson MI, Bell TAS, Gallegos-Graves LV, Dunbar J, Albright M. Merging Fungal and Bacterial Community Profiles via an Internal Control. MICROBIAL ECOLOGY 2021; 82:484-497. [PMID: 33410932 DOI: 10.1007/s00248-020-01638-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 11/03/2020] [Indexed: 06/12/2023]
Abstract
Integrated measurements of fungi and bacteria are critical to understand how interactions between these taxa drive key processes in ecosystems ranging from soils to animal guts. High-throughput amplicon sequencing is commonly used to census microbiomes, but the genetic markers targeted for fungi and bacteria (typically ribosomal regions) are domain-specific so profiling must be performed separately, obscuring relationships between these groups. To solve this problem, we developed a spike-in method with an internal control (IC) construct containing primer sites commonly used for bacterial and fungal taxonomic profiling. The internal control offers several advantages: estimation of absolute abundances, estimation of fungal to bacterial ratios (F:B), integration of bacterial and fungal profiles for holistic community analysis, and lower costs compared to other quantitation methods. To validate the IC as a scaling method, we compared IC-derived measures of F:B to measures from quantitative PCR (qPCR) using a commercial mock community (the ZymoBiomic Microbial Community DNA Standard II, containing two fungi and eight bacteria) and complex environmental samples. For both the mock community and the environmental samples, the IC produced F:B values that were statistically consistent with qPCR. Merging the environmental fungal and bacterial profiles based on the IC-derived F:B values revealed new relationships among samples in terms of community similarity. This IC method is the first spike-in method to employ a single construct for cross-domain amplicon sequencing, offering more reliable measurements.
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Affiliation(s)
- Miriam I Hutchinson
- Biosciences Division, Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM, 87545, USA
| | - Tisza A S Bell
- Biosciences Division, Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM, 87545, USA
- Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | | | - John Dunbar
- Biosciences Division, Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM, 87545, USA
| | - Michaeline Albright
- Biosciences Division, Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM, 87545, USA.
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7
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Aerobic Conditions and Endogenous Reactive Oxygen Species Reduce the Production of Infectious MS2 Phage by Escherichia coli. Viruses 2021; 13:v13071376. [PMID: 34372580 PMCID: PMC8310082 DOI: 10.3390/v13071376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/06/2021] [Accepted: 07/12/2021] [Indexed: 11/16/2022] Open
Abstract
Most of the defective/non-infectious enteric phages and viruses that end up in wastewater originate in human feces. Some of the causes of this high level of inactivity at the host stage are unknown. There is a significant gap between how enteric phages are environmentally transmitted and how we might design molecular tools that would only detect infectious ones. Thus, there is a need to explain the low proportion of infectious viral particles once replicated. By analyzing lysis plaque content, we were able to confirm that, under aerobic conditions, Escherichia coli produce low numbers of infectious MS2 phages (I) than the total number of phages indicated by the genome copies (G) with an I/G ratio of around 2%. Anaerobic conditions of replication and ROS inhibition increase the I/G ratio to 8 and 25%, respectively. These data cannot only be explained by variations in the total numbers of MS2 phages produced or in the metabolism of E. coli. We therefore suggest that oxidative damage impacts the molecular replication and assembly of MS2 phages.
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8
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The multi-drug efflux system AcrABZ-TolC is essential for infection of Salmonella Typhimurium by the flagellum-dependent bacteriophage Chi. J Virol 2021; 95:JVI.00394-21. [PMID: 33731456 PMCID: PMC8139690 DOI: 10.1128/jvi.00394-21] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bacteriophages are the most abundant biological entities in the biosphere. Due to their host specificity and ability to kill bacteria rapidly, bacteriophages have many potential healthcare applications, including therapy against antibiotic-resistant bacteria. Infection by flagellotropic bacteriophages requires a properly rotating bacterial flagellar filament. The flagella-dependent phage χ (Chi) infects serovars of the pathogenic enterobacterium Salmonella enterica However, cell surface receptors and proteins involved in other stages of χ infection have not been discovered to date. We screened a multi-gene deletion library of S. enterica serovar Typhimurium by spotting mutants on soft agar plates seeded with bacteriophage χ and monitoring their ability to grow and form a swim ring, a characteristic of bacteriophage-resistant motile mutants. Those multi-gene deletion regions identified to be important for χ infectivity were further investigated by characterizing the phenotypes of corresponding single-gene deletion mutants. This way, we identified motile mutants with varying degrees of resistance to χ. Deletions in individual genes encoding the AcrABZ-TolC multi-drug efflux system drastically reduced infection by bacteriophage χ. Furthermore, an acrABtolC triple deletion strain was fully resistant to χ. Infection was severely reduced but not entirely blocked by the deletion of the gene tig encoding the molecular chaperone trigger factor. Finally, deletion in genes encoding enzymes involved in the synthesis of the antioxidants glutathione (GSH) and uric acid resulted in reduced infectivity. Our findings begin to elucidate poorly understood processes involved in later stages of flagellotropic bacteriophage infection and informs research aimed at the use of bacteriophages to combat antibiotic-resistant bacterial infections.IMPORTANCEAntimicrobial resistance is a large concern in the healthcare field. With more multi-drug resistant bacterial pathogens emerging, other techniques for eliminating bacterial infections are being explored. Among these is phage therapy, where combinations of specific phages are used to treat infections. Generally, phages utilize cell appendages and surface receptors for the initial attachment to their host. Phages that are flagellotropic are of particular interest because flagella are often important in bacterial virulence, making resistance to attachment of these phages harder to achieve without reducing virulence. This study discovered the importance of a multi-drug efflux pump for the infection of Salmonella enterica by a flagellotropic phage. In theory, if a bacterial pathogen develops phage resistance by altering expression of the efflux pump then the pathogen would simultaneously become more susceptible to the antibiotic substrates of the pump. Thus, co-administering antibiotics and flagellotropic phage may be a particularly potent antibacterial therapy.
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9
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Chassaing M, Bastin G, Robin M, Majou D, Belliot G, de Rougemont A, Boudaud N, Gantzer C. Free Chlorine and Peroxynitrite Alter the Capsid Structure of Human Norovirus GII.4 and Its Capacity to Bind Histo-Blood Group Antigens. Front Microbiol 2021; 12:662764. [PMID: 33927710 PMCID: PMC8076513 DOI: 10.3389/fmicb.2021.662764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/23/2021] [Indexed: 12/02/2022] Open
Abstract
Human noroviruses (HuNoVs) are one of the leading causes of acute gastroenteritis worldwide. HuNoVs are frequently detected in water and foodstuffs. Free chlorine and peroxynitrite (ONOO−) are two oxidants commonly encountered by HuNoVs in humans or in the environment during their natural life cycle. In this study, we defined the effects of these two oxidants on GII.4 HuNoVs and GII.4 virus-like particles (VLPs). The impact on the capsid structure, the major capsid protein VP1 and the ability of the viral capsid to bind to histo-blood group antigens (HBGAs) following oxidative treatments were analyzed. HBGAs are attachment factors that promote HuNoV infection in human hosts. Overall, our results indicate that free chlorine acts on regions involved in the stabilization of VP1 dimers in VLPs and affects their ability to bind to HBGAs. These effects were confirmed in purified HuNoVs. Some VP1 cross-links also take place after free chlorine treatment, albeit to a lesser extent. Not only ONOO− mainly produced VP1 cross-links but can also dissociate VLPs depending on the concentration applied. Nevertheless, ONOO− has less effect on HuNoV particles.
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Affiliation(s)
- Manon Chassaing
- Food Safety Department, ACTALIA, Saint-Lô, France.,Université de Lorraine, CNRS, LCPME, Nancy, France
| | | | - Maëlle Robin
- Food Safety Department, ACTALIA, Saint-Lô, France
| | | | - Gaël Belliot
- National Reference Centre for Gastroenteritis Viruses, Laboratory of Virology, University Hospital of Dijon, Dijon, France.,UMR PAM A 02.102 Procédés Alimentaires et Microbiologiques, Université de Bourgogne Franche-Comté/AgroSup Dijon, Dijon, France
| | - Alexis de Rougemont
- National Reference Centre for Gastroenteritis Viruses, Laboratory of Virology, University Hospital of Dijon, Dijon, France.,UMR PAM A 02.102 Procédés Alimentaires et Microbiologiques, Université de Bourgogne Franche-Comté/AgroSup Dijon, Dijon, France
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10
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de Paiva REF, Marçal Neto A, Santos IA, Jardim ACG, Corbi PP, Bergamini FRG. What is holding back the development of antiviral metallodrugs? A literature overview and implications for SARS-CoV-2 therapeutics and future viral outbreaks. Dalton Trans 2020; 49:16004-16033. [PMID: 33030464 DOI: 10.1039/d0dt02478c] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In light of the Covid-19 outbreak, this review brings together historical and current literature efforts towards the development of antiviral metallodrugs. Classical compounds such as CTC-96 and auranofin are discussed in depth, as pillars for future metallodrug development. From the recent literature, both cell-based results and biophysical assays against potential viral biomolecule targets are summarized here. The comprehension of the biomolecular targets and their interactions with coordination compounds are emphasized as fundamental strategies that will foment further development of metal-based antivirals. We also discuss other possible and unexplored methods for unveiling metallodrug interactions with biomolecules related to viral replication and highlight the specific challenges involved in the development of antiviral metallodrugs.
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Affiliation(s)
- Raphael E F de Paiva
- Department of Fundamental Chemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, SP - 05508-000, Brazil.
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11
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Torii S, Itamochi M, Katayama H. Inactivation kinetics of waterborne virus by ozone determined by a continuous quench flow system. WATER RESEARCH 2020; 186:116291. [PMID: 32836147 DOI: 10.1016/j.watres.2020.116291] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/07/2020] [Accepted: 08/09/2020] [Indexed: 05/22/2023]
Abstract
Ozone has a strong oxidation power that allows effective inactivation of waterborne viruses. Few studies have accurately measured the kinetic relationship between virus inactivation and ozone exposure, because the high reactivity of ozone makes it difficult to measure them simultaneously. A continuous quench flow system (CQFS) is a possible solution for analyzing such a fast reaction; however, previous studies reported that CQFS provided different results of inactivation rate constants from the batch system. The objectives of this study were (1) to develop a CQFS to evaluate the kinetics of microbial inactivation accurately, (2) to evaluate the inactivation rate constants of waterborne virus by ozone, and (3) to compare the results with previous studies. The results indicated that the simple plug flow assumption in the reaction tube of CQFS led to underestimation of the rate constants. The accurate measurement of rate constants was achieved by the pseudo-first-order reaction model that takes the residence time distribution (RTD; i.e., the laminar flow assumption) into account. The results of inactivation experiments suggested that the resistance of viruses were getting higher in the following order: Qβ < MS2, fr, GA < CVB5 Faulkner, φX-174, PV1 Sabin, CVB3 Nancy. The environmental isolates of CVB3 and CVB5 had a 2-fold higher resistance compared with their lab strains. Predicted CT values for 4-log inactivation ranged from 0.018 mg sec L-1 (Qβ) to 0.31 mg sec L-1 (CVB3 Environmental strain). The required CT values for 4-log PV1 inactivation was 0.15 mg sec L-1, which was 166-fold smaller than those reported in the United States Environmental Protection Agency guidance manuals. The overestimation in previous studies was due to the sparse assumption of RTD in the reactor. Consequently, the required ozone CT values for virus inactivation should be reconsidered to minimize the health risks and environmental costs in water treatment.
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Affiliation(s)
- Shotaro Torii
- Department of Urban Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.
| | - Masae Itamochi
- Department of Virology, Toyama Institute of Health, 17-1 Nakataikoyama, Imizu-shi, Toyama, Japan
| | - Hiroyuki Katayama
- Department of Urban Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
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Chassaing M, Robin M, Loutreul J, Majou D, Belliot G, de Rougemont A, Boudaud N, Gantzer C. The effect of proteolytic enzymes and pH on GII.4 norovirus, during both interactions and non-interaction with Histo-Blood Group Antigens. Sci Rep 2020; 10:17926. [PMID: 33087754 PMCID: PMC7578656 DOI: 10.1038/s41598-020-74728-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 10/06/2020] [Indexed: 02/07/2023] Open
Abstract
Human noroviruses (HuNoVs) are the leading cause of acute gastroenteritis worldwide. Histo-Blood Groups Antigens (HBGAs) have been described as attachment factors, promoting HuNoV infection. However, their role has not yet been elucidated. This study aims to evaluate the ability of HBGAs to protect HuNoVs against various factors naturally found in the human digestive system. The effects of acid pH and proteolytic enzymes (pepsin, trypsin, and chymotrypsin) on GII.4 virus-like particles (VLPs) and GII.4 HuNoVs were studied, both during interactions and non-interaction with HBGAs. The results showed that GII.4 VLPs and GII.4 HuNoVs behaved differently following the treatments. GII.4 VLPs were disrupted at a pH of less than 2.0 and in the presence of proteolytic enzymes (1,500 units/mL pepsin, 100 mg/mL trypsin, and 100 mg/mL chymotrypsin). VLPs were also partially damaged by lower concentrations of trypsin and chymotrypsin (0.1 mg/mL). Conversely, the capsids of GII.4 HuNoVs were not compromised by such treatments, since their genomes were not accessible to RNase. HBGAs were found to offer GII.4 VLPs no protection against an acid pH or proteolytic enzymes.
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Affiliation(s)
- Manon Chassaing
- Food Safety Department, Actalia, 50000, Saint-Lô, France
- University of Lorraine, CNRS, LCPME, 54000, Nancy, France
| | - Maëlle Robin
- Food Safety Department, Actalia, 50000, Saint-Lô, France
| | - Julie Loutreul
- Food Safety Department, Actalia, 50000, Saint-Lô, France
| | | | - Gaël Belliot
- Laboratory of Virology, National Reference Centre for Gastroenteritis Viruses, University Hospital of Dijon, 21000, Dijon, France
- UMR PAM A 02.102 Procédés Alimentaires et Microbiologiques, Université de Bourgogne Franche-Comté/AgroSup Dijon, 21000, Dijon, France
| | - Alexis de Rougemont
- Laboratory of Virology, National Reference Centre for Gastroenteritis Viruses, University Hospital of Dijon, 21000, Dijon, France
- UMR PAM A 02.102 Procédés Alimentaires et Microbiologiques, Université de Bourgogne Franche-Comté/AgroSup Dijon, 21000, Dijon, France
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Interaction between norovirus and Histo-Blood Group Antigens: A key to understanding virus transmission and inactivation through treatments? Food Microbiol 2020; 92:103594. [PMID: 32950136 DOI: 10.1016/j.fm.2020.103594] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 06/27/2020] [Accepted: 07/02/2020] [Indexed: 02/06/2023]
Abstract
Human noroviruses (HuNoVs) are a main cause of acute gastroenteritis worldwide. They are frequently involved in foodborne and waterborne outbreaks. Environmental transmission of the virus depends on two main factors: the ability of viral particles to remain infectious and their adhesion capacity onto different surfaces. Until recently, adhesion of viral particles to food matrices was mainly investigated by considering non-specific interactions (e.g. electrostatic, hydrophobic) and there was only limited information about infectious HuNoVs because of the absence of a reliable in vitro HuNoV cultivation system. Many HuNoV strains have now been described as having specific binding interactions with human Histo-Blood Group Antigens (HBGAs) and non-HBGA ligands found in food and the environment. Relevant approaches to the in vitro replication of HuNoVs were also proposed recently. On the basis of the available literature data, this review discusses the opportunities to use this new knowledge to obtain a better understanding of HuNoV transmission to human populations and better evaluate the hazard posed by HuNoVs in foodstuffs and the environment.
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Bastin G, Loison P, Vernex-Loset L, Dupire F, Challant J, Majou D, Boudaud N, Krier G, Gantzer C. Structural Organizations of Qβ and MS2 Phages Affect Capsid Protein Modifications by Oxidants Hypochlorous Acid and Peroxynitrite. Front Microbiol 2020; 11:1157. [PMID: 32582098 PMCID: PMC7283501 DOI: 10.3389/fmicb.2020.01157] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 05/06/2020] [Indexed: 12/19/2022] Open
Abstract
Pathogenic enteric viruses and bacteriophages such as Qβ and MS2 are transmitted through the fecal-oral route. However, oxidants such as peroxynitrite (ONOOH) and hypochlorous acid (HClO) can prevent new infection by inactivating infectious viruses. Their virucidal effect is well recognized, and yet predicting the effects of oxidants on viruses is currently impossible because the detailed mechanisms of viral inactivation remain unclear. Our data show that ONOOH and HClO cross-linked the capsid proteins and RNA genomes of Qβ and MS2 phages. Consistently, the capsids appeared intact by transmission electron microscopy (TEM) even when 99% of the phages were inactivated by oxidation. Moreover, a precise molecular study of the capsid proteins shows that ONOOH and HClO preferentially targeted capsid protein regions containing the oxidant-sensitive amino acid C, Y, or W. Interestingly, the interaction of these amino acids was a crucial parameter defining whether they would be modified by the addition of O, Cl, or NO2 or whether it induced the loss of the protein region detected by mass spectrometry, together suggesting potential sites for cross-link formation. Together, these data show that HClO and ONOOH consistently target oxidant-sensitive amino acids regardless of the structural organization of Qβ and MS2, even though the phenotypes change as a function of the interaction with adjacent proteins/RNA. These data also indicate a potential novel mechanism of viral inactivation in which cross-linking may impair infectivity.
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Affiliation(s)
- Guillaume Bastin
- Université de Lorraine, CNRS, LCPME, Nancy, France.,ACTALIA, Food Safety Department, Saint-Lô, France
| | | | | | | | | | | | | | - Gabriel Krier
- Université de Lorraine, LCP-A2MC, EA 4632, Metz, France
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15
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Brié A, Gantzer C, Boudaud N, Bertrand I. The impact of chlorine and heat on the infectivity and physicochemical properties of bacteriophage MS2. FEMS Microbiol Ecol 2019; 94:5033402. [PMID: 29878194 DOI: 10.1093/femsec/fiy106] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 05/29/2018] [Indexed: 11/14/2022] Open
Abstract
Enteric viruses and bacteriophages are exposed to various inactivating factors outside their host, and among them chlorine and heat are the most commonly used sanitizer in water industry and treatment in the food industry, respectively. Using MS2 phages as models for enteric viruses, we investigated the impact of free chlorine and heat on their physicochemical properties. Free chlorine was first evaluated alone. No increase in either capsid permeability or hydrophobicity was observed. The negative surface charge slightly increased suggesting molecular changes in the capsid. However, a weakening of the capsid by chlorine was suggested by differential scanning fluorimetry. This phenomenon was confirmed when chlorination was followed by a heat treatment. Indeed, an increase in the inactivation of MS2 phages and the permeability of their capsids to RNases was observed. More interestingly, an increase in the expression of hydrophobic domains at the phage surface was observed, but only for phages remaining infectious. The chlorine-caused weakening of the capsid suggested that, for an optimal use, the oxidant should be followed by heat. The increased permeability to RNases and the expression of hydrophobic domains may contribute to the development or improvement of molecular methods specific for infectious enteric viruses.
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Affiliation(s)
- Adrien Brié
- Laboratoire de Chimie Physique et Microbiologie pour les Matériaux et l'Environnement (LCPME), UMR 7564 CNRS Université de Lorraine, Faculté de Pharmacie, 5 rue Albert Lebrun, BP 80403, 54001 Nancy, France.,Food Safety Department, ACTALIA, 310 rue Popielujko, 50000 Saint Lô, France
| | - Christophe Gantzer
- Laboratoire de Chimie Physique et Microbiologie pour les Matériaux et l'Environnement (LCPME), UMR 7564 CNRS Université de Lorraine, Faculté de Pharmacie, 5 rue Albert Lebrun, BP 80403, 54001 Nancy, France
| | - Nicolas Boudaud
- Food Safety Department, ACTALIA, 310 rue Popielujko, 50000 Saint Lô, France
| | - Isabelle Bertrand
- Laboratoire de Chimie Physique et Microbiologie pour les Matériaux et l'Environnement (LCPME), UMR 7564 CNRS Université de Lorraine, Faculté de Pharmacie, 5 rue Albert Lebrun, BP 80403, 54001 Nancy, France
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Brown SP, Leopold DR, Busby PE. Protocols for Investigating the Leaf Mycobiome Using High-Throughput DNA Sequencing. Methods Mol Biol 2018; 1848:39-51. [PMID: 30182227 DOI: 10.1007/978-1-4939-8724-5_4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
High-throughput sequencing of taxon-specific loci, or DNA metabarcoding, has become an invaluable tool for investigating the composition of plant-associated fungal communities and for elucidating plant-fungal interactions. While sequencing fungal communities has become routine, there remain numerous potential sources of systematic error that can introduce biases and compromise metabarcoding data. This chapter presents a protocol for DNA metabarcoding of the leaf mycobiome based on current best practices to minimize errors through careful laboratory practices and validation.
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Affiliation(s)
- Shawn P Brown
- Department of Biological Sciences, University of Memphis, Memphis, TN, USA
| | - Devin R Leopold
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, USA
| | - Posy E Busby
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, USA.
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