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Kumari S, Das S. Functional amyloid fibrils of biofilm-forming marine bacterium Pseudomonas aeruginosa PFL-P1 interact spontaneously with pyrene and augment the biodegradation. Int J Biol Macromol 2024; 266:131266. [PMID: 38556224 DOI: 10.1016/j.ijbiomac.2024.131266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/13/2024] [Accepted: 03/28/2024] [Indexed: 04/02/2024]
Abstract
Bacteria thrive in biofilms embedding in the three-dimensional extracellular polymeric substances (EPS). Functional Amyloid in Pseudomonas (Fap), a protein in EPS, efficiently sequesters polycyclic aromatic hydrocarbons (PAHs). Present study reports the characterization of Fap fibrils from Pseudomonas aeruginosa PFL-P1 and describes the interaction with pyrene to assess the impact on pyrene degradation. Overexpression of fap in E. coli BL21(DE3) cells significantly enhances biofilm formation (p < 0.0001) and amyloid production (p = 0.0002), particularly with pyrene. Defibrillated Fap analysis reveals FapC monomers and increased fibrillation with pyrene. Circular Dichroism (CD), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (XRD) unveil characteristic amyloid peaks and structural changes in Fap fibrils upon pyrene exposure. 3D-EEM analysis identifies a protein-like fluorophore in Fap fibrils, exhibiting pyrene-induced fluorescence quenching. Binding constants range from 5.23 to 7.78 M-1, with ΔG of -5.10 kJ mol-1 at 298 K, indicating spontaneous and exothermic interaction driven by hydrophobic forces. Exogenous Fap fibrils substantially increased the biofilm growth and pyrene degradation by P. aeruginosa PFL-P1 from 46 % to 64 % within 7 days (p = 0.0236). GC-MS identifies diverse metabolites, implying phthalic acid pathway in pyrene degradation. This study deepens insights into structural dynamics of Fap fibrils when exposed to pyrene, offering potential application in environmental bioremediation.
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Affiliation(s)
- Swetambari Kumari
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Surajit Das
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India.
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2
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Yang K, Yong JY, He Y, Yu L, Luo GN, Chen J, Ge YM, Yang YJ, Ding WJ, Hu YM. Melatonin restores DNFB-induced dysbiosis of skin microbiota in a mouse model of atopic dermatitis. Life Sci 2024; 342:122513. [PMID: 38387700 DOI: 10.1016/j.lfs.2024.122513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 02/04/2024] [Accepted: 02/19/2024] [Indexed: 02/24/2024]
Abstract
BACKGROUND The epidermic microbiota plays crucial roles in the pathogenesis of atopic dermatitis (AD), a common inflammatory skin disease. Melatonin (MLT) has been shown to ameliorate skin damage in AD patients, yet the underlying mechanism is unclear. METHODS Using 2,4-dinitrofluorobenzene (DNFB) to induce an AD model, MLT intervention was applied for 14 days to observe its pharmaceutical effect. Skin lesions were observed using HE staining, toluidine blue staining and electron microscopy. Dermal proinflammatory factor (IL-4 and IL-13) and intestinal barrier indices (ZO1 and Occludin) were assessed by immunohistochemistry and RT-qPCR, respectively. The dysbiotic microbiota was analyzed using 16S rRNA sequencing. RESULTS MLT significantly improved skin lesion size; inflammatory status (mast cells, IgE, IL-4, and IL-13); and the imbalance of the epidermal microbiota in AD mice. Notably, Staphylococcus aureus is the key bacterium associated with dysbiosis of the epidermal microbiota and may be involved in the fine modulation of mast cells, IL-4, IL-13 and IgE. Correlation analysis between AD and the gut revealed that intestinal dysbiosis occurred earlier than that of the pathological structure in the gut. CONCLUSION Melatonin reverses DNFB-induced skin damage and epidermal dysbiosis, especially in S. aureus.
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Affiliation(s)
- Kun Yang
- Chengdu University of Traditional Chinese Medicine, 1166 Liutai Avenue, Chengdu, Sichuan 611137, China
| | - Jiang-Yan Yong
- Chengdu University of Traditional Chinese Medicine, 1166 Liutai Avenue, Chengdu, Sichuan 611137, China; Hospital of Chengdu University of Traditional Chinese Medicine, No.39 Shi-er-qiao Road, Chengdu, 610072, SichuanProvince, China
| | - Yan He
- Chengdu University of Traditional Chinese Medicine, 1166 Liutai Avenue, Chengdu, Sichuan 611137, China
| | - Lu Yu
- Chengdu University of Traditional Chinese Medicine, 1166 Liutai Avenue, Chengdu, Sichuan 611137, China
| | - Gui-Ning Luo
- Chengdu University of Traditional Chinese Medicine, 1166 Liutai Avenue, Chengdu, Sichuan 611137, China
| | - Jilan Chen
- Chengdu University of Traditional Chinese Medicine, 1166 Liutai Avenue, Chengdu, Sichuan 611137, China
| | - Yi-Man Ge
- Chengdu University of Traditional Chinese Medicine, 1166 Liutai Avenue, Chengdu, Sichuan 611137, China; Hospital of Chengdu University of Traditional Chinese Medicine, No.39 Shi-er-qiao Road, Chengdu, 610072, SichuanProvince, China
| | - You-Jun Yang
- Chengdu University of Traditional Chinese Medicine, 1166 Liutai Avenue, Chengdu, Sichuan 611137, China
| | - Wei-Jun Ding
- School of Basic Medical Sciences, Chengdu University of Traditional Chinese Medicine, 1166 Liutai Avenue, Chengdu, Sichuan 611137, China.
| | - Yi-Mei Hu
- Chengdu University of Traditional Chinese Medicine, 1166 Liutai Avenue, Chengdu, Sichuan 611137, China; Hospital of Chengdu University of Traditional Chinese Medicine, No.39 Shi-er-qiao Road, Chengdu, 610072, SichuanProvince, China.
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3
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Mergani A, Meurer M, Wiebe E, Dümmer K, Wirz K, Lehmann J, Brogden G, Schenke M, Künnemann K, Naim HY, Grassl GA, von Köckritz-Blickwede M, Seeger B. Alteration of cholesterol content and oxygen level in intestinal organoids after infection with Staphylococcus aureus. FASEB J 2023; 37:e23279. [PMID: 37902583 DOI: 10.1096/fj.202300799r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 08/16/2023] [Accepted: 10/13/2023] [Indexed: 10/31/2023]
Abstract
The pathogenicity elicited by Staphylococcus (S.) aureus, one of the best-studied bacteria, in the intestine is not well understood. Recently, we demonstrated that S. aureus infection induces alterations in membrane composition that are associated with concomitant impairment of intestinal function. Here, we used two organoid models, induced pluripotent stem cell (iPSC)-derived intestinal organoids and colonic intestinal stem cell-derived intestinal organoids (colonoids), to examine how sterol metabolism and oxygen levels change in response to S. aureus infection. HPLC quantification showed differences in lipid homeostasis between infected and uninfected cells, characterized by a remarkable decrease in total cellular cholesterol. As the altered sterol metabolism is often due to oxidative stress response, we next examined intracellular and extracellular oxygen levels. Three different approaches to oxygen measurement were applied: (1) cell-penetrating nanoparticles to quantify intracellular oxygen content, (2) sensor plates to quantify extracellular oxygen content in the medium, and (3) a sensor foil system for oxygen distribution in organoid cultures. The data revealed significant intracellular and extracellular oxygen drop after infection in both intestinal organoid models as well as in Caco-2 cells, which even 48 h after elimination of extracellular bacteria, did not return to preinfection oxygen levels. In summary, we show alterations in sterol metabolism and intra- and extracellular hypoxia as a result of S. aureus infection. These results will help understand the cellular stress responses during sustained bacterial infections in the intestinal epithelium.
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Affiliation(s)
- AhmedElmontaser Mergani
- Institute of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Hannover, Germany
| | - Marita Meurer
- Institute of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Hannover, Germany
| | - Elena Wiebe
- Institute for Food Quality and Food Safety, Research Group Food Toxicology and Replacement/Complementary Methods to Animal Testing, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Katrin Dümmer
- Institute of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Hannover, Germany
| | - Katrin Wirz
- Institute of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Hannover, Germany
| | - Judith Lehmann
- Institute for Food Quality and Food Safety, Research Group Food Toxicology and Replacement/Complementary Methods to Animal Testing, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Graham Brogden
- Institute of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Hannover, Germany
| | - Maren Schenke
- Institute for Food Quality and Food Safety, Research Group Food Toxicology and Replacement/Complementary Methods to Animal Testing, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Katrin Künnemann
- Institute of Medical Microbiology and Hospital Epidemiology and German Center for Infection Research (DZIF), Partner Site Hannover, Hannover Medical School, Hannover, Germany
| | - Hassan Y Naim
- Institute of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Guntram A Grassl
- Institute of Medical Microbiology and Hospital Epidemiology and German Center for Infection Research (DZIF), Partner Site Hannover, Hannover Medical School, Hannover, Germany
| | - Maren von Köckritz-Blickwede
- Institute of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Hannover, Germany
| | - Bettina Seeger
- Institute for Food Quality and Food Safety, Research Group Food Toxicology and Replacement/Complementary Methods to Animal Testing, University of Veterinary Medicine Hannover, Hannover, Germany
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4
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Wang G, Sweren E, Andrews W, Li Y, Chen J, Xue Y, Wier E, Alphonse MP, Luo L, Miao Y, Chen R, Zeng D, Lee S, Li A, Dare E, Kim D, Archer NK, Reddy SK, Resar L, Hu Z, Grice EA, Kane MA, Garza LA. Commensal microbiome promotes hair follicle regeneration by inducing keratinocyte HIF-1α signaling and glutamine metabolism. SCIENCE ADVANCES 2023; 9:eabo7555. [PMID: 36598999 PMCID: PMC9812389 DOI: 10.1126/sciadv.abo7555] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 11/23/2022] [Indexed: 05/06/2023]
Abstract
Tissue injury induces metabolic changes in stem cells, which likely modulate regeneration. Using a model of organ regeneration called wound-induced hair follicle neogenesis (WIHN), we identified skin-resident bacteria as key modulators of keratinocyte metabolism, demonstrating a positive correlation between bacterial load, glutamine metabolism, and regeneration. Specifically, through comprehensive multiomic analysis and single-cell RNA sequencing in murine skin, we show that bacterially induced hypoxia drives increased glutamine metabolism in keratinocytes with attendant enhancement of skin and hair follicle regeneration. In human skin wounds, topical broad-spectrum antibiotics inhibit glutamine production and are partially responsible for reduced healing. These findings reveal a conserved and coherent physiologic context in which bacterially induced metabolic changes improve the tolerance of stem cells to damage and enhance regenerative capacity. This unexpected proregenerative modulation of metabolism by the skin microbiome in both mice and humans suggests important methods for enhancing regeneration after injury.
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Affiliation(s)
- Gaofeng Wang
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, Guangdong Province 510515, China
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - Evan Sweren
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - William Andrews
- Department of Pharmaceutical Sciences, School of Pharmacy Mass Spectrometry Center, University of Maryland, Baltimore, MD 21201, USA
| | - Yue Li
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, Guangdong Province 510515, China
| | - Junjun Chen
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - Yingchao Xue
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - Eric Wier
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - Martin P. Alphonse
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - Li Luo
- Departments of Medicine, Oncology, Pathology and Institute for Cellular Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - Yong Miao
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, Guangdong Province 510515, China
| | - Ruosi Chen
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, Guangdong Province 510515, China
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - Dongqiang Zeng
- Department of Oncology, Nanfang Hospital of Southern Medical University, Guangzhou, Guangdong Province 510515, China
| | - Sam Lee
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - Ang Li
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - Erika Dare
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - Dongwon Kim
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
- Department of Bio-Chemical Engineering, Dongseo University, Busan, Republic of Korea
| | - Nathan K. Archer
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - Sashank K. Reddy
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
- Department of Plastic and Reconstructive Surgery, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | - Linda Resar
- Departments of Medicine, Oncology, Pathology and Institute for Cellular Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
| | - Zhiqi Hu
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, Guangdong Province 510515, China
| | - Elizabeth A. Grice
- Department of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Maureen A. Kane
- Department of Pharmaceutical Sciences, School of Pharmacy Mass Spectrometry Center, University of Maryland, Baltimore, MD 21201, USA
| | - Luis A. Garza
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21210, USA
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5
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Tibbits G, Mohamed A, Gelston S, Flurin L, Raval YS, Greenwood-Quaintance KE, Patel R, Beyenal H. Activity of a hypochlorous acid-producing electrochemical bandage as assessed with a porcine explant biofilm model. Biotechnol Bioeng 2023; 120:250-259. [PMID: 36168277 PMCID: PMC10091757 DOI: 10.1002/bit.28248] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/18/2022] [Accepted: 09/25/2022] [Indexed: 11/10/2022]
Abstract
The activity of a hypochlorous acid-producing electrochemical bandage (e-bandage) in preventing methicillin-resistant Staphylococcus aureus infection (MRSA) infection and removing biofilms formed by MRSA was assessed using a porcine explant biofilm model. e-Bandages inhibited S. aureus infection (p = 0.029) after 12 h (h) of exposure and reduced 3-day biofilm viable cell counts after 6, 12, and 24 h exposures (p = 0.029). Needle-type microelectrodes were used to assess HOCl concentrations in explant tissue as a result of e-bandage treatment; toxicity associated with e-bandage treatment was evaluated. HOCl concentrations in infected and uninfected explant tissue varied between 30 and 80 µM, decreasing with increasing distance from the e-bandage. Eukaryotic cell viability was reduced by an average of 71% and 65% in fresh and day 3-old explants, respectively, when compared to explants exposed to nonpolarized e-bandages. HOCl e-bandages are a promising technology that can be further developed as an antibiotic-free treatment for wound biofilm infections.
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Affiliation(s)
- Gretchen Tibbits
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, USA
| | - Abdelrhman Mohamed
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, USA
| | - Suzanne Gelston
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, USA
| | - Laure Flurin
- Divison of Clinical Microbiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Yash S Raval
- Divison of Clinical Microbiology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Robin Patel
- Divison of Clinical Microbiology, Mayo Clinic, Rochester, Minnesota, USA.,Division of Public Health, Infectious Diseases and Occupational Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Haluk Beyenal
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, USA
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6
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Mohamed A, Raval YS, Gelston S, Tibbits G, Ay SU, Flurin L, Greenwood-Quaintance KE, Patel R, Beyenal H. Anti-Biofilm Activity of a Tunable Hypochlorous Acid-Generating Electrochemical Bandage Controlled By a Wearable Potentiostat. ADVANCED ENGINEERING MATERIALS 2023; 25:2200792. [PMID: 36817722 PMCID: PMC9937732 DOI: 10.1002/adem.202200792] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Indexed: 05/07/2023]
Abstract
Chronic wound biofilm infections represent a major clinical challenge which results in a substantial burden to patients and healthcare systems. Treatment with topical antibiotics is oftentimes ineffective as a result of antibiotic-resistant microorganisms and biofilm-specific antibiotic tolerance. Use of biocides such as hypochlorous acid (HOCl) has gained increasing attention due to the lack of known resistance mechanisms. We designed an HOCl-generating electrochemical bandage (e-bandage) that delivers HOCl continuously at low concentrations targeting infected wound beds in a similar manner to adhesive antimicrobial wound dressings. We developed a battery-operated wearable potentiostat that controls the e-bandage electrodes at potentials suitable for HOCl generation. We demonstrated that e-bandage treatment was tunable by changing the applied potential. HOCl generation on electrode surfaces was verified using microelectrodes. The developed e-bandage showed time-dependent responses against in vitro Acinetobacter baumannii and Staphylococcus aureus biofilms, reducing viable cells to non-detectable levels within 6 and 12 hours of treatment, respectively. The developed e-bandage should be further evaluated as an alternative to topical antibiotics to treat wound biofilm infections.
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Affiliation(s)
- Abdelrhman Mohamed
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Pullman, WA, USA
| | - Yash S. Raval
- Division of Clinical Microbiology, Mayo Clinic, Rochester, MN, USA
| | - Suzanne Gelston
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Pullman, WA, USA
| | - Gretchen Tibbits
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Pullman, WA, USA
| | - Suat U. Ay
- Department of Electrical and Computer Engineering, University of Idaho, Moscow
| | - Laure Flurin
- Division of Clinical Microbiology, Mayo Clinic, Rochester, MN, USA
- Department of Intensive Care, University Hospital of Guadeloupe, Pointe-à-Pitre, France
| | | | - Robin Patel
- Division of Clinical Microbiology, Mayo Clinic, Rochester, MN, USA
- Division of Public Health, Infectious Diseases, and Occupational Medicine, Mayo Clinic, Rochester, MN, USA
| | - Haluk Beyenal
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Pullman, WA, USA
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7
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Zhang H, Zheng J, Sun Y, Yang C, Yue Y. NF-κB signaling pathway mechanism in cow intertoe skin inflammation caused by Fusobacterium necrophorum. Front Cell Infect Microbiol 2023; 13:1156449. [PMID: 37153149 PMCID: PMC10160445 DOI: 10.3389/fcimb.2023.1156449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 03/17/2023] [Indexed: 05/09/2023] Open
Abstract
Background Fusobacterium necrophorum is the main pathogen inducing bovine foot rot. The infected site is often accompanied by a strong inflammatory response, but the specific inflammatory regulatory mechanism remains unclear. Aim A cow skin explants model was established to elucidate the mechanism of F. necrophorum bacillus causing foot rot in cows, and to provide reference for future clinical practice. Methods Cow intertoe skin explants were cultured in vitro, and F. necrophorum bacteria solution and nuclear factor-κB (NF-κB) inhibitor BAY 1-7082 were added to establish an in vitro infection model. Hematoxylin and eosin staining, terminal - deoxynucleotidyl transferase mediated nick end labeling, and immunohistochemistry were used to detect the pathological changes of the skin explants infected with F. necrophorum, the degree of tissue cell apoptosis, and the expression of the apoptosis-related protein Caspase-3, respectively. RT-qPCR, Western blot, and ELISA were used to detect the activation of the NF-κB pathway and inflammatory cytokines by F. necrophorum. Results The intertoe skin structure of cows infected with F. necrophorum changed with different degrees of inflammation, and the degree of tissue cell apoptosis was significantly increased (P < 0.01). In addition, infection with F. necrophorum significantly increased the phosphorylation level of IκBα protein and up-regulated the expression level of NF-κB p65. The high expression and transcriptional activity of NF-κB p65 significantly increased the expression and concentration of the inflammatory cytokines TNF-α, IL-1β, and IL-8, thus inducing the occurrence of an inflammatory response. However, inhibition of NF-κB p65 activity significantly decreased the expression of inflammatory factors in the intertoe skin of cows infected with F. necrophorum. Conclusion F. necrophorum activates NF-κB signaling pathway by increasing the expression of TNF-α, IL-1β, IL-8 and other inflammatory factors, leading to foot rot in dairy cows.
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8
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Antibiotics Limit Adaptation of Drug-Resistant Staphylococcus aureus to Hypoxia. Antimicrob Agents Chemother 2022; 66:e0092622. [PMID: 36409116 PMCID: PMC9765076 DOI: 10.1128/aac.00926-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Bacterial pathogens are confronted with a range of challenges at the site of infection, including exposure to antibiotic treatment and harsh physiological conditions, that can alter the fitness benefits and costs of acquiring antibiotic resistance. Here, we develop an experimental system to recapitulate resistance gene acquisition by Staphylococcus aureus and test how the subsequent evolution of the resistant bacterium is modulated by antibiotic treatment and oxygen levels, both of which are known to vary extensively at sites of infection. We show that acquiring tetracycline resistance was costly, reducing competitive growth against the isogenic strain without the resistance gene in the absence of the antibiotic, for S. aureus under hypoxic but not normoxic conditions. Treatment with tetracycline or doxycycline drove the emergence of enhanced resistance through mutations in an RluD-like protein-encoding gene and duplications of tetL, encoding the acquired tetracycline-specific efflux pump. In contrast, evolutionary adaptation by S. aureus to hypoxic conditions, which evolved in the absence of antibiotics through mutations affecting gyrB, was impeded by antibiotic treatment. Together, these data suggest that the horizontal acquisition of a new resistance mechanism is merely a starting point for the emergence of high-level resistance under antibiotic selection but that antibiotic treatment constrains pathogen adaptation to other important environmental selective forces such as hypoxia, which in turn could limit the survival of these highly resistant but poorly adapted genotypes after antibiotic treatment is ended.
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9
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Development of an implantable three-dimensional model of a functional pathogenic multispecies biofilm to study infected wounds. Sci Rep 2022; 12:21846. [PMID: 36528648 PMCID: PMC9759537 DOI: 10.1038/s41598-022-25569-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
Chronic wounds cannot heal due to impairment of regeneration, mainly caused by the persistent infection of multispecies biofilms. Still, the effects of biofilm wound infection and its interaction with the host are not fully described. We aimed to study functional biofilms in physiological conditions in vitro, and their potential effects in health and regeneration in vivo. Therefore, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis were seeded in collagen-based scaffolds for dermal regeneration. After 24 h, scaffolds had bacterial loads depending on the initial inoculum, containing viable biofilms with antibiotic tolerance. Afterwards, scaffolds were implanted onto full skin wounds in mice, together with daily supervision and antibiotic treatment. Although all mice survived their health was affected, displaying fever and weight loss. After ten days, histomorphology of scaffolds showed high heterogeneity in samples and within groups. Wounds were strongly, mildly, or not infected according to colony forming units, and P. aeruginosa had higher identification frequency. Biofilm infection induced leucocyte infiltration and elevated interferon-γ and interleukin-10 in scaffolds, increase of size and weight of spleen and high systemic pro-calcitonin concentrations. This functional and implantable 3D biofilm model allows to study host response during infection, providing a useful tool for infected wounds therapy development.
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10
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An Altered Skin and Gut Microbiota Are Involved in the Modulation of Itch in Atopic Dermatitis. Cells 2022; 11:cells11233930. [PMID: 36497188 PMCID: PMC9736894 DOI: 10.3390/cells11233930] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/14/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
Skin and gut microbiota play an important role in the pathogenesis of atopic dermatitis (AD). An alteration of the microbiota diversity modulates the development and course of AD, e.g., decreased microbiome diversity correlates with disease severity, particularly in lesional skin of AD. Itch is a hallmark of AD with unsatisfying treatment until now. Recent evidence suggests a possible role of microbiota in altering itch in AD through gut-skin-brain interactions. The microbial metabolites, proinflammatory cytokines, and impaired immune response lead to a modulation of histamine-independent itch, disruption of epidermal barrier, and central sensitization of itch mechanisms. The positive impact of probiotics in alleviating itch in AD supports this hypothesis, which may lead to novel strategies for managing itchy skin in AD patients. This review summarizes the emerging findings on the correlation between an altered microbiota and gut-skin-brain axis in AD, especially in modulating itchy skin.
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11
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Tibbits G, Mohamed A, Gelston S, Flurin L, Raval YS, Greenwood‐Quaintance K, Patel R, Beyenal H. Efficacy and toxicity of hydrogen peroxide producing electrochemical bandages in a porcine explant biofilm model. J Appl Microbiol 2022; 133:3755-3767. [PMID: 36073322 PMCID: PMC9671841 DOI: 10.1111/jam.15812] [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: 04/19/2022] [Revised: 06/30/2022] [Accepted: 08/30/2022] [Indexed: 01/11/2023]
Abstract
AIMS Effects of H2 O2 producing electrochemical-bandages (e-bandages) on methicillin-resistant Staphylococcus aureus colonization and biofilm removal were assessed using a porcine explant biofilm model. Transport of H2 O2 produced from the e-bandage into explant tissue and associated potential toxicity were evaluated. METHODS AND RESULTS Viable prokaryotic cells from infected explants were quantified after 48 h treatment with e-bandages in three ex vivo S. aureus infection models: (1) reducing colonization, (2) removing young biofilms and (3) removing mature biofilms. H2 O2 concentration-depth profiles in explants/biofilms were measured using microelectrodes. Reductions in eukaryotic cell viability of polarized and nonpolarized noninfected explants were compared. e-Bandages effectively reduced S. aureus colonization (p = 0.029) and reduced the viable prokaryotic cell concentrations of young biofilms (p = 0.029) with limited effects on mature biofilms (p > 0.1). H2 O2 penetrated biofilms and explants and reduced eukaryotic cell viability by 32-44% compared to nonpolarized explants. CONCLUSIONS H2 O2 producing e-bandages were most active when used to reduce colonization and remove young biofilms rather than to remove mature biofilms. SIGNIFICANCE AND IMPACT OF STUDY The described e-bandages reduced S. aureus colonization and young S. aureus biofilms in a porcine explant wound model, supporting their further development as an antibiotic-free alternative for managing biofilm infections.
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Affiliation(s)
- Gretchen Tibbits
- The Gene and Linda Voiland School of Chemical Engineering and BioengineeringWashington State UniversityPullmanWashingtonUSA
| | - Abdelrhman Mohamed
- The Gene and Linda Voiland School of Chemical Engineering and BioengineeringWashington State UniversityPullmanWashingtonUSA
| | - Suzanne Gelston
- The Gene and Linda Voiland School of Chemical Engineering and BioengineeringWashington State UniversityPullmanWashingtonUSA
| | - Laure Flurin
- Division of Clinical MicrobiologyMayo ClinicRochesterMinnesotaUSA
| | - Yash S. Raval
- Division of Clinical MicrobiologyMayo ClinicRochesterMinnesotaUSA
| | | | - Robin Patel
- Division of Clinical MicrobiologyMayo ClinicRochesterMinnesotaUSA,Division of Public Health, Infectious Diseases and Occupational MedicineMayo ClinicRochesterMinnesotaUSA
| | - Haluk Beyenal
- The Gene and Linda Voiland School of Chemical Engineering and BioengineeringWashington State UniversityPullmanWashingtonUSA
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12
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Murashkin NN, Epishev RV, Ivanov RA, Materikin AI, Opryatin LA, Savelova AA, Nezhvedilova RY, Ambarchian ET, Fedorov DV, Rusakova LL. Innovations in Therapeutic Improvement of the Cutaneous Microbiome in Children with Atopic Dermatitis. CURRENT PEDIATRICS 2022. [DOI: 10.15690/vsp.v21i5.2449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Biofilm is the dominant form of skin microbiota organization that provides adhesion and preservation of microorganisms in the skin micro-environment. It is necessary to ensure epidermal barrier function and local immunomodulation. Staphylococcus aureus becomes the major colonizer of skin lesions in case of atopic dermatitis exacerbation, and it also can form the biofilms. S. aureus growth and biofilm formation due to other microbial commensals on the skin of patients with atopic dermatitis leads to chronic output of pro-inflammatory cytokines and later to abnormalities in healthy skin microbiome. The role of microbial biofilm in human’s health makes the skin microbiota an attractive target for therapeutic intervention in various skin diseases.
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Affiliation(s)
- N. N. Murashkin
- National Medical Research Center of Children’s Health; Sechenov First Moscow State Medical University; Central State Medical Academy of Department of Presidential Affairs
| | - R. V. Epishev
- National Medical Research Center of Children’s Health
| | - R. A. Ivanov
- National Medical Research Center of Children’s Health
| | | | | | | | | | - E. T. Ambarchian
- Pediatrics and Child Health Research Institute in Petrovsky National Research Centre of Surgery
| | - D. V. Fedorov
- National Medical Research Center of Children’s Health
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13
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The battle for oxygen during bacterial and fungal infections. Trends Microbiol 2022; 30:643-653. [DOI: 10.1016/j.tim.2022.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/07/2022] [Accepted: 01/10/2022] [Indexed: 12/22/2022]
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14
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Mirzaei R, Sabokroo N, Ahmadyousefi Y, Motamedi H, Karampoor S. Immunometabolism in biofilm infection: lessons from cancer. Mol Med 2022; 28:10. [PMID: 35093033 PMCID: PMC8800364 DOI: 10.1186/s10020-022-00435-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 01/10/2022] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Biofilm is a community of bacteria embedded in an extracellular matrix, which can colonize different human cells and tissues and subvert the host immune reactions by preventing immune detection and polarizing the immune reactions towards an anti-inflammatory state, promoting the persistence of biofilm-embedded bacteria in the host. MAIN BODY OF THE MANUSCRIPT It is now well established that the function of immune cells is ultimately mediated by cellular metabolism. The immune cells are stimulated to regulate their immune functions upon sensing danger signals. Recent studies have determined that immune cells often display distinct metabolic alterations that impair their immune responses when triggered. Such metabolic reprogramming and its physiological implications are well established in cancer situations. In bacterial infections, immuno-metabolic evaluations have primarily focused on macrophages and neutrophils in the planktonic growth mode. CONCLUSION Based on differences in inflammatory reactions of macrophages and neutrophils in planktonic- versus biofilm-associated bacterial infections, studies must also consider the metabolic functions of immune cells against biofilm infections. The profound characterization of the metabolic and immune cell reactions could offer exciting novel targets for antibiofilm therapy.
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Affiliation(s)
- Rasoul Mirzaei
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
- Venom and Biotherapeutics Molecules Lab, Medical Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
| | - Niloofar Sabokroo
- Department of Microbiology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Yaghoub Ahmadyousefi
- Department of Medical Biotechnology, School of Advanced Medical Sciences and Technologies, Hamadan University of Medical Sciences, Hamadan, Iran
- Research Center for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Hamid Motamedi
- Department of Microbiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Sajad Karampoor
- Gastrointestinal and Liver Diseases Research Center, Iran University of Medical Sciences, Tehran, Iran.
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
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15
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Forson AM, Rosman CWK, van Kooten TG, van der Mei HC, Sjollema J. Micrococcal Nuclease stimulates Staphylococcus aureus Biofilm Formation in a Murine Implant Infection Model. Front Cell Infect Microbiol 2022; 11:799845. [PMID: 35111695 PMCID: PMC8801922 DOI: 10.3389/fcimb.2021.799845] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 12/21/2021] [Indexed: 12/22/2022] Open
Abstract
Advancements in contemporary medicine have led to an increasing life expectancy which has broadened the application of biomaterial implants. As each implant procedure has an innate risk of infection, the number of biomaterial-associated infections keeps rising. Staphylococcus aureus causes 34% of such infections and is known as a potent biofilm producer. By secreting micrococcal nuclease S. aureus is able to escape neutrophil extracellular traps by cleaving their DNA-backbone. Also, micrococcal nuclease potentially limits biofilm growth and adhesion by cleaving extracellular DNA, an important constituent of biofilms. This study aimed to evaluate the impact of micrococcal nuclease on infection persistence and biofilm formation in a murine biomaterial-associated infection-model with polyvinylidene-fluoride mesh implants inoculated with bioluminescent S. aureus or its isogenic micrococcal nuclease deficient mutant. Supported by results based on in-vivo bioluminescence imaging, ex-vivo colony forming unit counts, and histological analysis it was found that production of micrococcal nuclease enables S. aureus bacteria to evade the immune response around an implant resulting in a persistent infection. As a novel finding, histological analysis provided clear indications that the production of micrococcal nuclease stimulates S. aureus to form biofilms, the presence of which extended neutrophil extracellular trap formation up to 13 days after mesh implantation. Since micrococcal nuclease production appeared vital for the persistence of S. aureus biomaterial-associated infection, targeting its production could be a novel strategy in preventing biomaterial-associated infection.
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16
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Thapa RK, Winther-Larsen HC, Ovchinnikov K, Carlsen H, Diep DB, Tønnesen HH. Hybrid hydrogels for bacteriocin delivery to infected wounds. Eur J Pharm Sci 2021; 166:105990. [PMID: 34481880 DOI: 10.1016/j.ejps.2021.105990] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/12/2021] [Accepted: 08/31/2021] [Indexed: 01/30/2023]
Abstract
Superficial infections in chronic wounds can prevent the wound healing process by the development of persistent infections and drug-resistant biofilms. Topically applied antimicrobial formulations with stabilized and controlled release offer significant benefits for the effective treatment of wound infections. Bacteriocins are the antimicrobial peptides (AMPs) produced by bacteria that are viable alternatives to antibiotics owing to their natural origin and low propensity for resistance development. Herein, we developed a hybrid hydrogel composed of Pluronic F127 (PF127), ethylenediaminetetraacetic acid (EDTA) loaded liposomes, glutathione (GSH), and the bacteriocin Garvicin KS (GarKS) referred to as "GarKS gel". The GarKS gel exhibited suitable viscosity and rheological properties along with controlled release behavior (up to 9 days) for effective peptide delivery following topical application. Potent in vitro antibacterial and anti-biofilm effects of GarKS gel were evident against the Gram-positive bacterium Staphylococcus aureus. The in vivo treatment of methicillin resistant S. aureus (MRSA) infected mouse wounds suggested potent antibacterial effects of the GarKS gel following multiple applications of once-a-day application for three consecutive days. Altogether, these results provide proof-of-concept for the successful development of AMP loaded topical formulation for effective treatment of wound infections.
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Affiliation(s)
- Raj Kumar Thapa
- Section for Pharmaceutics and Social Pharmacy, Department of Pharmacy, University of Oslo, P. O. Box 1068 Blindern, NO-0316 Oslo, Norway.
| | - Hanne Cecilie Winther-Larsen
- Centre for Integrative Microbial Evolution (CIME) and Department of Pharmacology and Pharmaceutical Biosciences, University of Oslo, Sem Sælands vei 3, NO-0371 Oslo, Norway
| | - Kirill Ovchinnikov
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway
| | - Harald Carlsen
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway
| | - Dzung B Diep
- Faculty of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway
| | - Hanne Hjorth Tønnesen
- Section for Pharmaceutics and Social Pharmacy, Department of Pharmacy, University of Oslo, P. O. Box 1068 Blindern, NO-0316 Oslo, Norway
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17
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Blicharz L, Rudnicka L, Czuwara J, Waśkiel-Burnat A, Goldust M, Olszewska M, Samochocki Z. The Influence of Microbiome Dysbiosis and Bacterial Biofilms on Epidermal Barrier Function in Atopic Dermatitis-An Update. Int J Mol Sci 2021; 22:ijms22168403. [PMID: 34445108 PMCID: PMC8395079 DOI: 10.3390/ijms22168403] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 07/31/2021] [Accepted: 08/02/2021] [Indexed: 12/13/2022] Open
Abstract
Atopic dermatitis (AD) is a common inflammatory dermatosis affecting up to 30% of children and 10% of adults worldwide. AD is primarily driven by an epidermal barrier defect which triggers immune dysregulation within the skin. According to recent research such phenomena are closely related to the microbial dysbiosis of the skin. There is growing evidence that cutaneous microbiota and bacterial biofilms negatively affect skin barrier function, contributing to the onset and exacerbation of AD. This review summarizes the latest data on the mechanisms leading to microbiome dysbiosis and biofilm formation in AD, and the influence of these phenomena on skin barrier function.
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Affiliation(s)
- Leszek Blicharz
- Department of Dermatology, Medical University of Warsaw, 02-008 Warsaw, Poland; (L.R.); (J.C.); (A.W.-B.); (M.O.); (Z.S.)
- Correspondence:
| | - Lidia Rudnicka
- Department of Dermatology, Medical University of Warsaw, 02-008 Warsaw, Poland; (L.R.); (J.C.); (A.W.-B.); (M.O.); (Z.S.)
| | - Joanna Czuwara
- Department of Dermatology, Medical University of Warsaw, 02-008 Warsaw, Poland; (L.R.); (J.C.); (A.W.-B.); (M.O.); (Z.S.)
| | - Anna Waśkiel-Burnat
- Department of Dermatology, Medical University of Warsaw, 02-008 Warsaw, Poland; (L.R.); (J.C.); (A.W.-B.); (M.O.); (Z.S.)
| | - Mohamad Goldust
- Department of Dermatology, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany;
| | - Małgorzata Olszewska
- Department of Dermatology, Medical University of Warsaw, 02-008 Warsaw, Poland; (L.R.); (J.C.); (A.W.-B.); (M.O.); (Z.S.)
| | - Zbigniew Samochocki
- Department of Dermatology, Medical University of Warsaw, 02-008 Warsaw, Poland; (L.R.); (J.C.); (A.W.-B.); (M.O.); (Z.S.)
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18
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Strong Antimicrobial and Healing Effects of Beta-Acids from Hops in Methicillin-Resistant Staphylococcus aureus-Infected External Wounds In Vivo. Antibiotics (Basel) 2021; 10:antibiotics10060708. [PMID: 34204644 PMCID: PMC8231114 DOI: 10.3390/antibiotics10060708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/04/2021] [Accepted: 06/10/2021] [Indexed: 11/21/2022] Open
Abstract
Staphylococcus (S.) aureus is an important causative agent of wound infections with increasing incidence in the past decades. Specifically, the emergence of methicillin-resistant S. aureus (MRSA) causes serious problems, especially in nosocomial infections. Therefore, there is an urgent need to develop of alternative or supportive antimicrobial therapeutic modalities to meet these challenges. Purified compounds from hops have previously shown promising antimicrobial effects against MRSA isolates in vitro. In this study, purified beta-acids from hops were tested for their potential antimicrobial and healing properties using a porcine model of wounds infected by MRSA. The results show highly significant antimicrobial effects of the active substance in both the powder and Ambiderman-based application forms compared to both no-treatment control and treatment with Framycoin. Moreover, the macroscopic evaluation of the wounds during the treatment using the standardized Wound Healing Continuum indicated positive effects of the beta-acids on the overall wound healing. This is further supported by the microscopic data, which showed a clear improvement of the inflammatory parameters in the wounds treated by beta-acids. Thus, using the porcine model, we demonstrate significant therapeutic effects of hops compounds in the management of wounds infected by MRSA. Beta-acids from hops, therefore, represent a suitable candidate for the treatment of non-responsive nosocomial tissue infections by MRSA.
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19
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André AC, Debande L, Marteyn BS. The selective advantage of facultative anaerobes relies on their unique ability to cope with changing oxygen levels during infection. Cell Microbiol 2021; 23:e13338. [PMID: 33813807 DOI: 10.1111/cmi.13338] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 12/19/2022]
Abstract
Bacteria, including those that are pathogenic, have been generally classified according to their ability to survive and grow in the presence or absence of oxygen: aerobic and anaerobic bacteria, respectively. Strict aerobes require oxygen to grow (e.g., Neisseria), and strict anaerobes grow exclusively without, and do not survive oxygen exposure (e.g., Clostridia); aerotolerant bacteria (e.g., Lactobacilli) are insensitive to oxygen exposure. Facultative anaerobes (e.g., E. coli) have the unique ability to grow in the presence or in the absence of oxygen and are thus well-adapted to these changing conditions, which may constitute an underestimated selective advantage for infection. In the WHO antibiotic-resistant 'priority pathogens' list, facultative anaerobes are overrepresented (8 among 12 listed pathogens), consistent with clinical studies performed in populations particularly susceptible to infectious diseases. Bacteria aerobic respiratory chain plays a central role in oxygen consumption, leading to the formation of hypoxic infectious sites (infectious hypoxia). Facultative anaerobes have developed a wide diversity of aerotolerance and anaerotolerance strategies in vivo. However, at a single cell level, the modulation of the intracellular oxygen level in host infected cells remains elusive and will be discussed in this review. In conclusion, the ability of facultative bacteria to evolve in the presence or the absence of oxygen is essential for their virulence strategy and constitute a selective advantage. TAKE AWAY: Most life-threatening pathogenic bacteria are facultative anaerobes. Only facultative anaerobes are aerotolerant, anaerotolerant and capable of consuming O2 . Facultative anaerobes induce and are well adapted to cellular hypoxia.
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Affiliation(s)
- Antonin C André
- Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l'ARN, CNRS UPR9002, Université de Strasbourg, Strasbourg, France.,Université de Paris, Paris, France
| | - Lorine Debande
- Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l'ARN, CNRS UPR9002, Université de Strasbourg, Strasbourg, France
| | - Benoit S Marteyn
- Institut de Biologie Moléculaire et Cellulaire, Architecture et Réactivité de l'ARN, CNRS UPR9002, Université de Strasbourg, Strasbourg, France.,University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France.,Institut Pasteur, Unité de Pathogenèse des Infections Vasculaires, Paris Cedex 15, France
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20
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Tsay JCJ, Wu BG, Sulaiman I, Gershner K, Schluger R, Li Y, Yie TA, Meyn P, Olsen E, Perez L, Franca B, Carpenito J, Iizumi T, El-Ashmawy M, Badri M, Morton JT, Shen N, He L, Michaud G, Rafeq S, Bessich JL, Smith RL, Sauthoff H, Felner K, Pillai R, Zavitsanou AM, Koralov SB, Mezzano V, Loomis CA, Moreira AL, Moore W, Tsirigos A, Heguy A, Rom WN, Sterman DH, Pass HI, Clemente JC, Li H, Bonneau R, Wong KK, Papagiannakopoulos T, Segal LN. Lower Airway Dysbiosis Affects Lung Cancer Progression. Cancer Discov 2021; 11:293-307. [PMID: 33177060 PMCID: PMC7858243 DOI: 10.1158/2159-8290.cd-20-0263] [Citation(s) in RCA: 121] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 09/15/2020] [Accepted: 10/27/2020] [Indexed: 11/16/2022]
Abstract
In lung cancer, enrichment of the lower airway microbiota with oral commensals commonly occurs, and ex vivo models support that some of these bacteria can trigger host transcriptomic signatures associated with carcinogenesis. Here, we show that this lower airway dysbiotic signature was more prevalent in the stage IIIB-IV tumor-node-metastasis lung cancer group and is associated with poor prognosis, as shown by decreased survival among subjects with early-stage disease (I-IIIA) and worse tumor progression as measured by RECIST scores among subjects with stage IIIB-IV disease. In addition, this lower airway microbiota signature was associated with upregulation of the IL17, PI3K, MAPK, and ERK pathways in airway transcriptome, and we identified Veillonella parvula as the most abundant taxon driving this association. In a KP lung cancer model, lower airway dysbiosis with V. parvula led to decreased survival, increased tumor burden, IL17 inflammatory phenotype, and activation of checkpoint inhibitor markers. SIGNIFICANCE: Multiple lines of investigation have shown that the gut microbiota affects host immune response to immunotherapy in cancer. Here, we support that the local airway microbiota modulates the host immune tone in lung cancer, affecting tumor progression and prognosis.See related commentary by Zitvogel and Kroemer, p. 224.This article is highlighted in the In This Issue feature, p. 211.
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Affiliation(s)
- Jun-Chieh J Tsay
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
- Division of Pulmonary and Critical Care Medicine, VA New York Harbor Healthcare System, New York, New York
| | - Benjamin G Wu
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
- Division of Pulmonary and Critical Care Medicine, VA New York Harbor Healthcare System, New York, New York
| | - Imran Sulaiman
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Katherine Gershner
- Section of Pulmonary, Critical Care, Allergy and Immunology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Rosemary Schluger
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Yonghua Li
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Ting-An Yie
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Peter Meyn
- NYU Langone Genomic Technology Center, New York University School of Medicine, New York, New York
| | - Evan Olsen
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Luisannay Perez
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Brendan Franca
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Joseph Carpenito
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Tadasu Iizumi
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Mariam El-Ashmawy
- Department of Medicine, New York University School of Medicine, New York, New York
| | - Michelle Badri
- Department of Biology, New York University, New York, New York
| | - James T Morton
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, New York
| | - Nan Shen
- Department of Genetics and Genomic Sciences and Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Linchen He
- Department of Population Health, New York University School of Medicine, New York, New York
| | - Gaetane Michaud
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Samaan Rafeq
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Jamie L Bessich
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Robert L Smith
- Division of Pulmonary and Critical Care Medicine, VA New York Harbor Healthcare System, New York, New York
| | - Harald Sauthoff
- Division of Pulmonary and Critical Care Medicine, VA New York Harbor Healthcare System, New York, New York
| | - Kevin Felner
- Division of Pulmonary and Critical Care Medicine, VA New York Harbor Healthcare System, New York, New York
| | - Ray Pillai
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | | | - Sergei B Koralov
- Department of Pathology, New York University School of Medicine, New York, New York
| | - Valeria Mezzano
- Department of Pathology, New York University School of Medicine, New York, New York
| | - Cynthia A Loomis
- Department of Pathology, New York University School of Medicine, New York, New York
| | - Andre L Moreira
- Department of Pathology, New York University School of Medicine, New York, New York
| | - William Moore
- Department of Radiology, New York University School of Medicine, New York, New York
| | - Aristotelis Tsirigos
- Department of Pathology, New York University School of Medicine, New York, New York
| | - Adriana Heguy
- NYU Langone Genomic Technology Center, New York University School of Medicine, New York, New York
- Department of Pathology, New York University School of Medicine, New York, New York
| | - William N Rom
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Daniel H Sterman
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York
| | - Harvey I Pass
- Department of Cardiothoracic Surgery, New York University School of Medicine, New York, New York
| | - Jose C Clemente
- Department of Genetics and Genomic Sciences and Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Huilin Li
- Department of Population Health, New York University School of Medicine, New York, New York
| | - Richard Bonneau
- Department of Biology, New York University, New York, New York
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, New York
- Center for Data Science, New York University School of Medicine, New York, New York
| | - Kwok-Kin Wong
- Division of Hematology and Oncology, New York University School of Medicine, New York, New York
| | | | - Leopoldo N Segal
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine, New York, New York.
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21
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Blanter M, Gouwy M, Struyf S. Studying Neutrophil Function in vitro: Cell Models and Environmental Factors. J Inflamm Res 2021; 14:141-162. [PMID: 33505167 PMCID: PMC7829132 DOI: 10.2147/jir.s284941] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 12/04/2020] [Indexed: 01/21/2023] Open
Abstract
Neutrophils are the most abundant immune cell type in the blood and constitute the first line of defense against invading pathogens. Despite their important role in many diseases, they are challenging to study due to their short life span and the inability to cryopreserve or expand them in vitro. Thus, research into neutrophils has to rely on cells freshly isolated from peripheral blood of human donors, introducing donor-dependent variation in the experimental data. To counteract these problems, researchers tried to develop adequate cell models, such as cell lines. For those functional studies that cannot rely on cell models, a standardization of protocols regarding neutrophil purification and culturing could be a solution. In this review, we provide an overview of the most commonly used models for neutrophil function (HL-60, PLB-985, NB4, Kasumi-1 and induced pluripotent stem cells). In addition, we describe the effects of glucose concentration, pH, oxygen tension and temperature on neutrophil function.
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Affiliation(s)
- Marfa Blanter
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, University of Leuven, Leuven 3000, Belgium
| | - Mieke Gouwy
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, University of Leuven, Leuven 3000, Belgium
| | - Sofie Struyf
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, University of Leuven, Leuven 3000, Belgium
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Bolotsky A, Muralidharan R, Butler D, Root K, Murray W, Liu Z, Ebrahimi A. Organic redox-active crystalline layers for reagent-free electrochemical antibiotic susceptibility testing (ORACLE-AST). Biosens Bioelectron 2020; 172:112615. [PMID: 33166804 DOI: 10.1016/j.bios.2020.112615] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 08/11/2020] [Accepted: 09/13/2020] [Indexed: 12/21/2022]
Abstract
Rapid antibiotic susceptibility testing (AST) is critical in determining bacterial resistance or susceptibility to a particular antibiotic. Simple-to-use phenotype-based AST platforms can assist care-givers in timely prescription of the right antibiotic. Monitoring the change of bacterial viability by measuring electrochemical Faradaic current is a promising approach for rapid AST. However, the existing works require mixing redox-active reagents in the solution which can interfere with the antibiotics. In this paper, we developed a facile electrodeposition process for creating a redox-active crystalline layer (denoted as RZx) on pyrolytic graphite sheets (PGS), which was then utilized as the sensing layer for reagent-free electrochemical AST. To demonstrate the proof-of-principle, we tested the sensors with Escherichia coli (E. coli) K-12 treated with two antibiotics, ampicillin and kanamycin. While the sensors enable detection of bacterial metabolism mainly due to pH-sensitivity of RZx (∼ 53 mV/pH), secreted redox-active metabolites/compounds from whole cells are likely contributing to the signal as well. By monitoring the differential voltammetric signals, the sensors enable accurate prediction of the minimum inhibitory concentration (MIC) in 60 min (p < 0.03). The sensors are stable after 60 days storage in ambient conditions and enable analysis of microbial viability in complex solutions, as demonstrated in spiked milk and human whole blood.
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Affiliation(s)
- Adam Bolotsky
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA; Materials Research Institute, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Ritvik Muralidharan
- School of Electrical Engineering and Computer Science, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Derrick Butler
- Materials Research Institute, The Pennsylvania State University, University Park, PA, 16802, USA; School of Electrical Engineering and Computer Science, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Kayla Root
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - William Murray
- Materials Research Institute, The Pennsylvania State University, University Park, PA, 16802, USA; School of Electrical Engineering and Computer Science, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Zhiwen Liu
- Materials Research Institute, The Pennsylvania State University, University Park, PA, 16802, USA; School of Electrical Engineering and Computer Science, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Aida Ebrahimi
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA; Materials Research Institute, The Pennsylvania State University, University Park, PA, 16802, USA; School of Electrical Engineering and Computer Science, The Pennsylvania State University, University Park, PA, 16802, USA.
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23
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Besser M, Dietrich M, Weber L, Rembe JD, Stuermer EK. Efficacy of antiseptics in a novel 3-dimensional human plasma biofilm model (hpBIOM). Sci Rep 2020; 10:4792. [PMID: 32179838 PMCID: PMC7075952 DOI: 10.1038/s41598-020-61728-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 02/26/2020] [Indexed: 11/09/2022] Open
Abstract
The increasing incidence of non-healing wounds constitutes a pivotal socio-economic burden. 60-80% of chronic wounds are colonized by pathogenic microorganisms within a protective extracellular polymeric substance, bearing a great challenge in wound management. Human plasma was used to prepare the biofilm model (hpBIOM), adding pathogens to the plasma and forming Coagula-like discs with integrated pathogens were produced. The antiseptics Octenisept and Lavasorb were tested regarding their antibacterial properties on clinically relevant biofilm-growing bacteria (MRSA, P. aeruginosa) in the hpBIOM. Biofilm-typical glycocalyx-formation was confirmed using immunohistochemical staining. Treatment of a 12 h-maturated biofilm with Octenisept resulted in complete eradication of P. aeruginosa and MRSA after 48 h. Lavasorb proved less effective than Octenisept in this setting. In more mature biofilms (24 h), both antiseptics showed a delayed, partially decreased efficacy. Summarized, the hpBIOM provides essential factors for a translational research approach to be used for detailed human biofilm analyses and evaluation of antimicrobial/-biofilm properties of established and novel therapeutic strategies and products. Octenisept and Lavasorb showed an attenuated efficacy in the hpBIOM compared to planktonic conditions and previously published biofilm-studies, prompting the question for the necessity of introducing new international standards and pre-admission requirements on a translational base.
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Affiliation(s)
- M Besser
- Institute for Translational Wound Research, Centre for Biomedical Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany.
| | - M Dietrich
- Institute for Translational Wound Research, Centre for Biomedical Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany
| | - L Weber
- Institute for Translational Wound Research, Centre for Biomedical Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany
| | - J D Rembe
- Institute for Translational Wound Research, Centre for Biomedical Education and Research (ZBAF), Witten/Herdecke University, Witten, Germany
| | - E K Stuermer
- Department of Vascular Medicine, University Heart Center, Translational Wound Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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24
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Thapa RK, Kiick KL, Sullivan MO. Encapsulation of collagen mimetic peptide-tethered vancomycin liposomes in collagen-based scaffolds for infection control in wounds. Acta Biomater 2020; 103:115-128. [PMID: 31843720 PMCID: PMC7044801 DOI: 10.1016/j.actbio.2019.12.014] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/26/2019] [Accepted: 12/10/2019] [Indexed: 12/13/2022]
Abstract
Wound infections are a significant clinical problem affecting millions of people worldwide. Topically applied antibacterial formulations with longer residence time and controlled antimicrobial release would offer significant benefits for improved prevention and treatment of infected wounds. In this study, we developed collagen mimetic peptide (CMP) tethered vancomycin (Van)-containing liposomes (Lipo) (CMP-Van-Lipo) hybridized to collagen-based hydrogels ('co-gels,' e.g., collagen/fibrin combination hydrogels) for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in vitro and in vivo. Tethering CMP-Van-Lipo nanostructures to co-gels enabled sustained Van release and enhanced in vitro antibacterial effects against MRSA as compared to Van loaded co-gels or Van-Lipo loaded co-gels following multiple fresh bacterial inoculations over a period of 48 h. These results were successfully translated in vivo wherein MRSA infected wounds were effectively treated with CMP-Van-Lipo loaded co-gels for up to 9 days, whereas the activity of Van loaded co-gels and Van-Lipo loaded co-gels were limited to <2 days. Moreover, CMP-Van-Lipo retained in vivo antibacterial activity even after re-inoculation with bacteria; however, Van loaded co-gels and Van-Lipo loaded co-gels allowed significant bacterial growth demonstrating their limited efficacy. Altogether, these results provide proof-of-concept that CMP-Van-Lipo loaded co-gels can be effective topical formulations for preventive treatment of MRSA wound infections. STATEMENT OF SIGNIFICANCE: Current topical antimicrobial formulations (e.g., creams, gels, and ointments) do not control release, leaving antimicrobial concentrations either too high or too low at different time points, and provoking the development of antibacterial resistance and recurrence of wound infections. Here, collagen mimetic peptides (CMPs) were used to stably hybridize vancomycin-containing liposomal nanocarriers (CMP-Van-Lipo) within collagen-fibrin co-gels via triple-helical integration with collagen, enabling control over Van release for prolonged time periods and minimizing the adverse effects of the Lipo formulations on fibroblast cell viability in the wound bed. The CMP-Van-Lipo loaded co-gel's higher antibacterial effects in vitro were successfully translated in vivo for treatment of MRSA-infected mouse wounds, and thus the co-gels can be a potentially translatable treatment for improved clinical wound management.
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Affiliation(s)
- Raj Kumar Thapa
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716 USA
| | - Kristi L Kiick
- Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716 USA.
| | - Millicent O Sullivan
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716 USA.
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25
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Branitzki-Heinemann K, Brogden G, von Köckritz-Blickwede M. Influence of Oxygen on Function and Cholesterol Composition of Murine Bone Marrow-Derived Neutrophils. Methods Mol Biol 2020; 2087:223-233. [PMID: 31728995 DOI: 10.1007/978-1-0716-0154-9_17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
During inflammation and infection, invading pathogens as well as infiltrating neutrophils locally consume oxygen and reduce the present oxygen level. Since oxygen is an elementary component of the microenvironment required for cell activity and alters multiple cellular functions, it is important to study neutrophil functionality and phenotype at characteristic pathophysiological oxygen levels that reflect the hypoxic phenotype during infection and inflammation. Here, we describe methods to study murine neutrophils under hypoxic compared to normoxic conditions, including analysis of cholesterol content as a key lipid involved in biological functions.
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Affiliation(s)
- Katja Branitzki-Heinemann
- Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Hannover, Germany
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Hannover, Germany
| | - Graham Brogden
- Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Maren von Köckritz-Blickwede
- Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Hannover, Germany.
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Hannover, Germany.
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26
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Direct Microscopic Observation of Human Neutrophil-Staphylococcus aureus Interaction In Vitro Suggests a Potential Mechanism for Initiation of Biofilm Infection on an Implanted Medical Device. Infect Immun 2019; 87:IAI.00745-19. [PMID: 31548325 DOI: 10.1128/iai.00745-19] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 09/19/2019] [Indexed: 01/29/2023] Open
Abstract
The ability of human neutrophils to clear newly attached Staphylococcus aureus bacteria from a serum-coated glass surface was examined in vitro using time-lapse confocal scanning laser microscopy. Quantitative image analysis was used to measure the temporal change in bacterial biomass, neutrophil motility, and fraction of the surface area policed by neutrophils. In control experiments in which the surface was inoculated with bacteria but no neutrophils were added, prolific bacterial growth was observed. Neutrophils were able to control bacterial growth but only consistently when the neutrophil/bacterium number ratio exceeded approximately 1. When preattached bacteria were given a head start and allowed to grow for 3 h prior to neutrophil addition, neutrophils were unable to maintain control of the nascent biofilm. In these head-start experiments, aggregates of bacterial biofilm with areas of 50 μm2 or larger formed, and the growth of such aggregates continued even when multiple neutrophils attacked a cluster. These results suggest a model for the initiation of a biofilm infection in which a delay in neutrophil recruitment to an abiotic surface allows surface-attached bacteria time to grow and form aggregates that become protected from neutrophil clearance. Results from a computational model of the neutrophil-biofilm surface contest supported this conceptual model and highlighted the stochastic nature of the interaction. Additionally, we observed that both neutrophil motility and clearance of bacteria were impaired when oxygen tension was reduced to 0% or 2% O2.
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27
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Hajdamowicz NH, Hull RC, Foster SJ, Condliffe AM. The Impact of Hypoxia on the Host-Pathogen Interaction between Neutrophils and Staphylococcus aureus. Int J Mol Sci 2019; 20:ijms20225561. [PMID: 31703398 PMCID: PMC6888323 DOI: 10.3390/ijms20225561] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 10/26/2019] [Accepted: 10/31/2019] [Indexed: 12/20/2022] Open
Abstract
Neutrophils are key to host defence, and impaired neutrophil function predisposes to infection with an array of pathogens, with Staphylococcus aureus a common and sometimes life-threatening problem in this setting. Both infiltrating immune cells and replicating bacteria consume oxygen, contributing to the profound tissue hypoxia that characterises sites of infection. Hypoxia in turn has a dramatic effect on both neutrophil bactericidal function and the properties of S. aureus, including the production of virulence factors. Hypoxia thereby shapes the host-pathogen interaction and the progression of infection, for example promoting intracellular bacterial persistence, enabling local tissue destruction with the formation of an encaging abscess capsule, and facilitating the establishment and propagation of bacterial biofilms which block the access of host immune cells. Elucidating the molecular mechanisms underlying host-pathogen interactions in the setting of hypoxia will enable better understanding of persistent and recalcitrant infections due to S. aureus and may uncover novel therapeutic targets and strategies.
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Affiliation(s)
- Natalia H Hajdamowicz
- Department of Infection, Immunity and Cardiovascular Diseases, University of Sheffield, Beech Hill Road, Sheffield S10 2TN, UK; (N.H.H.); (R.C.H.)
- Florey Institute, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK;
| | - Rebecca C Hull
- Department of Infection, Immunity and Cardiovascular Diseases, University of Sheffield, Beech Hill Road, Sheffield S10 2TN, UK; (N.H.H.); (R.C.H.)
- Florey Institute, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK;
| | - Simon J Foster
- Florey Institute, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK;
| | - Alison M Condliffe
- Department of Infection, Immunity and Cardiovascular Diseases, University of Sheffield, Beech Hill Road, Sheffield S10 2TN, UK; (N.H.H.); (R.C.H.)
- Florey Institute, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK;
- Correspondence:
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28
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Di Domenico EG, Cavallo I, Capitanio B, Ascenzioni F, Pimpinelli F, Morrone A, Ensoli F. Staphylococcus aureus and the Cutaneous Microbiota Biofilms in the Pathogenesis of Atopic Dermatitis. Microorganisms 2019; 7:E301. [PMID: 31470558 PMCID: PMC6780378 DOI: 10.3390/microorganisms7090301] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 08/12/2019] [Accepted: 08/28/2019] [Indexed: 12/31/2022] Open
Abstract
Biofilm is the dominant mode of growth of the skin microbiota, which promotes adhesion and persistence in the cutaneous microenvironment, thus contributing to the epidermal barrier function and local immune modulation. In turn, the local immune microenvironment plays a part in shaping the skin microbiota composition. Atopic dermatitis (AD) is an immune disorder characterized by a marked dysbiosis, with a sharp decline of microbial diversity. During AD flares biofilm-growing Staphylococcus aureus emerges as the major colonizer in the skin lesions, in strict association with disease severity. The chronic production of inflammatory cytokines in the skin of AD individuals concurs at supporting S. aureus biofilm overgrowth at the expense of other microbial commensals, subverting the composition of the healthy skin microbiome. The close relationship between the host and microbial biofilm resident in the skin has profound implications on human health, making skin microbiota an attractive target for the therapeutic management of different skin disorders.
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Affiliation(s)
- Enea Gino Di Domenico
- Clinical Pathology and Microbiology, San Gallicano Dermatologic Institute, IRCCS, 00144 Rome, Italy.
| | - Ilaria Cavallo
- Clinical Pathology and Microbiology, San Gallicano Dermatologic Institute, IRCCS, 00144 Rome, Italy
| | - Bruno Capitanio
- Division of Dermatology, San Gallicano Dermatologic Institute, IRCCS, 00144 Rome, Italy
| | - Fiorentina Ascenzioni
- Department of Biology and Biotechnology C. Darwin, University of Rome Sapienza, 00161 Rome, Italy
| | - Fulvia Pimpinelli
- Clinical Pathology and Microbiology, San Gallicano Dermatologic Institute, IRCCS, 00144 Rome, Italy
| | - Aldo Morrone
- Scientific Director San Gallicano Dermatological Institute IRCCS, 00144 Rome, Italy
| | - Fabrizio Ensoli
- Clinical Pathology and Microbiology, San Gallicano Dermatologic Institute, IRCCS, 00144 Rome, Italy
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29
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Artificial Selection for Pathogenicity Mutations in Staphylococcus aureus Identifies Novel Factors Relevant to Chronic Infection. Infect Immun 2019; 87:IAI.00884-18. [PMID: 30642903 DOI: 10.1128/iai.00884-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/10/2019] [Indexed: 02/06/2023] Open
Abstract
Adaptation of Staphylococcus aureus to host microenvironments during chronic infection involves spontaneous mutations, yet changes underlying adaptive phenotypes remain incompletely explored. Here, we employed artificial selection and whole-genome sequencing to better characterize spontaneous chromosomal mutations that alter two pathogenicity phenotypes relevant to chronic infection in S. aureus: intracellular invasiveness and intracellular cytotoxicity. We identified 23 genes whose alteration coincided with enhanced virulence, 11 that were previously known and 12 (52%) that had no previously described role in S. aureus pathogenicity. Using precision genome editing, transposon mutants, and gene complementation, we empirically assessed the contributions of individual genes to the two virulence phenotypes. We functionally validated 14 of 21 genes tested as measurably influencing invasion and/or cytotoxicity, including 8 newly implicated by this study. We identified inactivating mutations (murA, ndhC, and a hypothetical membrane protein) and gain-of-function mutations (aroE Thr182Ile, yhcF Thr74Ile, and Asp486Glu in a hypothetical peptidase) in previously unrecognized S. aureus virulence genes that enhance pathogenesis when introduced into a clean genetic background, as well as a novel activating mutation in the known virulence regulator gene saeS (Ala106Thr). Investigation of potentially epistatic interactions identified a tufA mutation (Ala271Val) that enhances virulence only in the context of purine operon repressor gene (purR) inactivation. This project reveals a functionally diverse range of genes affected by gain- or loss-of-function mutations that contribute to S. aureus adaptive virulence phenotypes. More generally, the work establishes artificial selection as a means to determine the genetic mechanisms underlying complex bacterial phenotypes relevant to adaptation during infection.
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30
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Kiamco MM, Zmuda HM, Mohamed A, Call DR, Raval YS, Patel R, Beyenal H. Hypochlorous-Acid-Generating Electrochemical Scaffold for Treatment of Wound Biofilms. Sci Rep 2019; 9:2683. [PMID: 30804362 PMCID: PMC6389966 DOI: 10.1038/s41598-019-38968-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 01/07/2019] [Indexed: 11/10/2022] Open
Abstract
Biofilm formation causes prolonged wound infections due to the dense biofilm structure, differential gene regulation to combat stress, and production of extracellular polymeric substances. Acinetobacter baumannii, Staphylococcus aureus, and Pseudomonas aeruginosa are three difficult-to-treat biofilm-forming bacteria frequently found in wound infections. This work describes a novel wound dressing in the form of an electrochemical scaffold (e-scaffold) that generates controlled, low concentrations of hypochlorous acid (HOCl) suitable for killing biofilm communities without substantially damaging host tissue. Production of HOCl near the e-scaffold surface was verified by measuring its concentration using needle-type microelectrodes. E-scaffolds producing 17, 10 and 7 mM HOCl completely eradicated S. aureus, A. baumannii, and P. aeruginosa biofilms after 3 hours, 2 hours, and 1 hour, respectively. Cytotoxicity and histopathological assessment showed no discernible harm to host tissues when e-scaffolds were applied to explant biofilms. The described strategy may provide a novel antibiotic-free strategy for treating persistent biofilm-associated infections, such as wound infections.
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Affiliation(s)
- Mia Mae Kiamco
- The Gene and Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA
| | - Hannah M Zmuda
- The Gene and Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA
| | - Abdelrhman Mohamed
- The Gene and Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA
| | - Douglas R Call
- The Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA, USA
| | - Yash S Raval
- Divisions of Clinical Microbiology, Rochester, MN, USA
| | - Robin Patel
- Divisions of Clinical Microbiology, Rochester, MN, USA
- Divisions of Infectious Diseases, Mayo Clinic, Rochester, MN, USA
| | - Haluk Beyenal
- The Gene and Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA.
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31
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Nasir NAM, Paus R, Ansell DM. Fluorescent cell tracer dye permits real-time assessment of re-epithelialization in a serum-free ex vivo human skin wound assay. Wound Repair Regen 2018; 27:126-133. [DOI: 10.1111/wrr.12688] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 10/29/2018] [Accepted: 11/10/2018] [Indexed: 11/27/2022]
Affiliation(s)
- Nur Azida Mohd Nasir
- Centre for Dermatology Research, School of Biological Sciences; The University of Manchester; Manchester United Kingdom
- School of Medical Sciences; Universiti Sains Malaysia; Kubang Kerian Malaysia
| | - Ralf Paus
- Centre for Dermatology Research, School of Biological Sciences; The University of Manchester; Manchester United Kingdom
- NIHR Manchester Biomedical Research Centre, The University of Manchester; Manchester United Kingdom
- Manchester Academic Health Sciences Centre, The University of Manchester; Manchester United Kingdom
| | - David M. Ansell
- Centre for Dermatology Research, School of Biological Sciences; The University of Manchester; Manchester United Kingdom
- Division of Cell Matrix Biology and Regenerative Medicine; The University of Manchester; Manchester United Kingdom
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32
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Rettinger CL, Wang HC. Quantitative Assessment of Retina Explant Viability in a Porcine Ex Vivo Neuroretina Model. J Ocul Pharmacol Ther 2018; 34:521-530. [PMID: 29924674 DOI: 10.1089/jop.2018.0021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
PURPOSE Given that porcine and human retinas have similar structures and characteristics, ex vivo culture of porcine neuroretina provides an attractive model for studying mechanisms of human retinal injury and degenerative disease. Here, we describe the method that was used to establish and characterize an adult porcine retina culture system as a rapid screening tool for retinal survival in real time. METHODS Neuroretina explants 8 mm in diameter were harvested from adult swine and cultured on porous cell culture inserts with adjustable heights. Retina explant viability was evaluated at 1, 4, 7, 11, and 14 days of culture using a resazurin-based metabolic assay. The explants were analyzed morphologically through immunohistochemistry for glial activation and apoptosis. Morphometric analysis was also performed on hematoxylin and eosin-stained retina sections from each time point. RESULTS The viability of retina explants gradually decreased over time in culture. The laminar structure of the neuroretina was well preserved during the first 7 days. However, by day 14, most explants showed significant loss of cells in each laminar layer and obvious thinning. Overall, the progressive loss of retinal lamination and thickness, and increase in apoptotic nuclei with activated hypertrophic Müller cells were well correlated with the metabolic activity of the ex vivo neuroretina explants. CONCLUSIONS This study was the first report to describe the use of a high-throughput and quantitative method for monitoring retina explant viability in real time. Ex vivo neuroretina cultures closely mimic the functional dynamics of the organ, and can be used efficiently to screen novel therapeutics for retinal neurodegenerative disease.
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Affiliation(s)
- Christina L Rettinger
- Ocular and Sensory Trauma Task Area, United States Army Institute of Surgical Research , Fort Sam Houston, Texas
| | - Heuy-Ching Wang
- Ocular and Sensory Trauma Task Area, United States Army Institute of Surgical Research , Fort Sam Houston, Texas
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33
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Rippon MG, Rogers AA, Sellars L, Styles KM, Westgate S. Effectiveness of a non-medicated wound dressing on attached and biofilm encased bacteria: laboratory and clinical evidence. J Wound Care 2018; 27:146-155. [DOI: 10.12968/jowc.2018.27.3.146] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Mark G. Rippon
- Visiting Clinical Research Fellow, Huddersfield University, Queensgate, Huddersfield
| | - Alan A. Rogers
- Medical Communications Consultant, Flintshire, North Wales
| | - Laura Sellars
- Senior Microbiologist, Perfectus Biomed Limited, Daresbury Laboratories, SciTech Daresbury, Cheshire
| | - Kathryn M. Styles
- Senior Microbiologist, Perfectus Biomed Limited, Daresbury Laboratories, SciTech Daresbury, Cheshire
| | - Samantha Westgate
- CEO, Perfectus Biomed Limited, Daresbury Laboratories, SciTech Daresbury, Cheshire
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34
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Boff D, Oliveira VLS, Queiroz Junior CM, Silva TA, Allegretti M, Verri WA, Proost P, Teixeira MM, Amaral FA. CXCR2 is critical for bacterial control and development of joint damage and pain in Staphylococcus aureus-induced septic arthritis in mouse. Eur J Immunol 2018; 48:454-463. [PMID: 29168180 DOI: 10.1002/eji.201747198] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 10/23/2017] [Accepted: 11/15/2017] [Indexed: 02/06/2023]
Abstract
Staphylococcus aureus is the main pathogen associated with septic arthritis. Upon infection, neutrophils are quickly recruited to the joint by different chemoattractants, especially CXCR1/2 binding chemokines. Although their excessive accumulation is associated with intense pain and permanent articular damage, neutrophils have an important function in controlling bacterial burden. This work aimed to study the role of CXCR2 in the control of infection, hypernociception and tissue damage in S. aureus-induced septic arthritis in mice. The kinetics of neutrophil recruitment correlated with the bacterial load recovered from inflamed joint after intra-articular injection of S. aureus. Treatment of mice from the start of infection with the non-competitive antagonist of CXCR1/2, DF2156A, reduced neutrophil accumulation, cytokine production in the tissue, joint hypernociception and articular damage. However, early DF2156A treatment increased the bacterial load locally. CXCR2 was important for neutrophil activation and clearance of bacteria in vitro and in vivo. Start of treatment with DF2156A 3 days after infection prevented increase in bacterial load and reduced the hypernociception in the following days, but did not improve tissue damage. In conclusion, treatment with DF2156A seems be effective in controlling tissue inflammation and dysfunction but its effects are highly dependent on the timing of the treatment start.
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Affiliation(s)
- Daiane Boff
- Imunofarmacologia, Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais Brazil.,Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Vivian L S Oliveira
- Imunofarmacologia, Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais Brazil
| | - Celso M Queiroz Junior
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Brazil
| | - Tarcília A Silva
- Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | - Waldiceu A Verri
- Department of Pathological Sciences, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Brazil
| | - Paul Proost
- Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Mauro M Teixeira
- Imunofarmacologia, Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais Brazil
| | - Flavio A Amaral
- Imunofarmacologia, Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais Brazil
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Wang Z, Zhu F. The expression profiles of immune genes in Mus musculus macrophages during Staphylococcus aureus infection. PLoS One 2018; 13:e0190490. [PMID: 29304086 PMCID: PMC5755788 DOI: 10.1371/journal.pone.0190490] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 12/17/2017] [Indexed: 01/15/2023] Open
Abstract
Staphylococcus aureus is an important pathogen which is often the cause of major morbidity and mortality in both hospital and community settings. For this reason, we investigated the host cell early immune resoponse to S. aureus infection using genome-wide analysis. To do this, we infected Mus musculus RAW264.7 cells with S. aureus alone or in the presence of free peptidoglycan (PG), which appears in the S. aureus cell wall. Post infection, we performed a genome-wide analysis of RAW246.7 cells to identify significant changes in the gene expression profile. Further, we analyzed the infected RAW246.7 cells with transmission electron microscopy looking for the presence of bacterial cells inside the host cell. We also used flow cytometry to determine whether cells had induced apoptosis. The results showed that S. aureus induced apoptosis in the RAW246.7 cells but did not effectively clear away intracellular bacteria cells. However, S. aureus + PG treatment inhibited the apoptosis and activated the host cell inflammation response, possibly involving NF-κB and JAK-STAT pathways, as identified by genome-wide analysis, in RAW246.7 cells. Our study demonstrated for the first time that an independent application of free PG was capable of activating immune responses the host cells.
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Affiliation(s)
- Ziyan Wang
- College of Animal Science and Technology, Zhejiang Agriculture and Forestry University, Hangzhou, China
| | - Fei Zhu
- College of Animal Science and Technology, Zhejiang Agriculture and Forestry University, Hangzhou, China
- * E-mail:
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Möllerherm H, Meier K, Schmies K, Fuhrmann H, Naim HY, von Köckritz-Blickwede M, Branitzki-Heinemann K. Differentiation and Functionality of Bone Marrow-Derived Mast Cells Depend on Varying Physiologic Oxygen Conditions. Front Immunol 2017; 8:1665. [PMID: 29250065 PMCID: PMC5714875 DOI: 10.3389/fimmu.2017.01665] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 11/14/2017] [Indexed: 01/17/2023] Open
Abstract
Mast cells (MCs) are long-living multifunctional innate immune cells that originate from hematopoietic precursors and specifically differentiate in the destination tissue, e.g., skin, respiratory mucosa, intestine, where they mediate immune cell recruitment and antimicrobial defense. In vivo these tissues have characteristic physiological oxygen levels that are considerably lower than the atmospheric oxygen conditions (159 mmHg, 21% O2; 5% CO2) traditionally used to differentiate MCs and to study their functionality in vitro. Only little is known about the impact of physiological oxygen conditions on the differentiation process of MCs. This study aimed to characterize the differentiation of immature murine bone marrow-derived MCs under physioxia in vitro (7% O2; 53 mmHg; 5% CO2). Bone marrow-derived suspension cells were differentiated in the presence of interleukin-3 with continuous, non-invasive determination of the oxygen level using a Fibox4-PSt3 measurement system without technique-caused oxygen consumption. Trypan blue staining confirmed cellular viability during the specified period. Interestingly, MCs cultivated at 7% O2 showed a significantly delayed differentiation rate defined by CD117-positive cells, analyzed by flow cytometry, and reached >95% CD117 positive population at day 32 after isolation. Importantly, MCs differentiated under physioxia displayed a decreased transcript expression level of hif-1α and selected target genes vegf, il-6, and tnf-α, but an increase of foxo3 and vhl expression compared to MCs cultivated under normoxia. Moreover, the production of reactive oxygen species as well as the amount of intracellular stored histamine was significantly lower in MCs differentiated under low oxygen levels, which might have consequences for their function such as immunomodulation of other immune cells. These results show for the first time that physioxia substantially affect maturation and the properties of MCs and highlight the need to study their function under physiologically relevant oxygen conditions.
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Affiliation(s)
- Helene Möllerherm
- Department of Physiological Chemistry, University for Veterinary Medicine Hannover, Hanover, Germany
| | - Karsten Meier
- Department of Physiological Chemistry, University for Veterinary Medicine Hannover, Hanover, Germany
| | - Kathrin Schmies
- Department of Physiological Chemistry, University for Veterinary Medicine Hannover, Hanover, Germany
| | - Herbert Fuhrmann
- Faculty of Veterinary Medicine, Institute of Biochemistry, University of Leipzig, Leipzig, Germany
| | - Hassan Y Naim
- Department of Physiological Chemistry, University for Veterinary Medicine Hannover, Hanover, Germany
| | - Maren von Köckritz-Blickwede
- Department of Physiological Chemistry, University for Veterinary Medicine Hannover, Hanover, Germany.,Research Center for Emerging Infections and Zoonoses (RIZ), University for Veterinary Medicine Hannover, Hanover, Germany
| | - Katja Branitzki-Heinemann
- Department of Physiological Chemistry, University for Veterinary Medicine Hannover, Hanover, Germany
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Balasubramanian D, Harper L, Shopsin B, Torres VJ. Staphylococcus aureus pathogenesis in diverse host environments. Pathog Dis 2017; 75:ftx005. [PMID: 28104617 DOI: 10.1093/femspd/ftx005] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/18/2017] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is an eminent human pathogen that can colonize the human host and cause severe life-threatening illnesses. This bacterium can reside in and infect a wide range of host tissues, ranging from superficial surfaces like the skin to deeper tissues such as in the gastrointestinal tract, heart and bones. Due to its multifaceted lifestyle, S. aureus uses complex regulatory networks to sense diverse signals that enable it to adapt to different environments and modulate virulence. In this minireview, we explore well-characterized environmental and host cues that S. aureus responds to and describe how this pathogen modulates virulence in response to these signals. Lastly, we highlight therapeutic approaches undertaken by several groups to inhibit both signaling and the cognate regulators that sense and transmit these signals downstream.
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Affiliation(s)
- Divya Balasubramanian
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Lamia Harper
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Bo Shopsin
- Department of Medicine, Division of Infectious Diseases, New York University School of Medicine, New York, NY 10016 USA
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
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38
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Möllerherm H, Branitzki-Heinemann K, Brogden G, Elamin AA, Oehlmann W, Fuhrmann H, Singh M, Naim HY, von Köckritz-Blickwede M. Hypoxia Modulates the Response of Mast Cells to Staphylococcus aureus Infection. Front Immunol 2017; 8:541. [PMID: 28553287 PMCID: PMC5425595 DOI: 10.3389/fimmu.2017.00541] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 04/24/2017] [Indexed: 12/23/2022] Open
Abstract
To study the antimicrobial function of immune cells ex vivo, cells are commonly cultivated under atmospheric oxygen concentrations (20–21%; normoxia), although the physiological oxygen conditions in vivo are significantly lower in most tissues. Especially during an acute infection, oxygen concentration locally decreases to hypoxic levels around or below 1%. The goal of this study was to investigate the effect of hypoxia on the activity of mast cells (MCs). MCs were cultivated for 3 or 24 h at 1% O2 in a hypoxia glove box and co-incubated with heat-inactivated Staphylococcus aureus. When incubating the cells for 24 h under hypoxia, the transcriptional regulator hypoxia-inducible factor 1α (HIF-1α) was stabilized and resulted in increased extracellular trap formation and decreased phagocytosis. Interestingly, while phagocytosis of fluorescent S. aureus bioparticles as well as the release of extracellular traps remained unaffected at 3 h hypoxia, the secretion of the prestored mediator histamine was increased under hypoxia alone. In contrast, the release of TNF-α was generally reduced at 3 h hypoxia. Microarray transcriptome analysis revealed 13 genes that were significantly downregulated in MCs comparing 3 h hypoxia versus normoxia. One interesting candidate is sec24, a member of the pre-budding complex of coat protein complex II (COPII), which is responsible for the anterograde transport of proteins from the ER to the Golgi apparatus. These data lead to the suggestion that de novo synthesized proteins including crucial factors, which are involved in the response to an acute infection like TNF-α, may eventually be retained in the ER under hypoxia. Importantly, the expression of HIF-1α was not altered at 3 h. Thus, our data exhibit a HIF-1α-independent reaction of MCs to short-term hypoxia. We hypothesize that MCs respond to short-term low oxygen levels in a HIF-1α-independent manner by downregulating the release of proinflammatory cytokines like TNF-α, thereby avoiding uncontrolled degranulation, which could lead to excessive inflammation and severe tissue damage.
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Affiliation(s)
- Helene Möllerherm
- Department of Physiological Chemistry, University for Veterinary Medicine Hannover, Hanover, Germany
| | - Katja Branitzki-Heinemann
- Department of Physiological Chemistry, University for Veterinary Medicine Hannover, Hanover, Germany
| | - Graham Brogden
- Department of Physiological Chemistry, University for Veterinary Medicine Hannover, Hanover, Germany
| | | | - Wulf Oehlmann
- LIONEX Diagnostics & Therapeutics, Braunschweig, Germany
| | - Herbert Fuhrmann
- Faculty of Veterinary Medicine, Institute of Biochemistry, University of Leipzig, Leipzig, Germany
| | - Mahavir Singh
- LIONEX Diagnostics & Therapeutics, Braunschweig, Germany
| | - Hassan Y Naim
- Department of Physiological Chemistry, University for Veterinary Medicine Hannover, Hanover, Germany
| | - Maren von Köckritz-Blickwede
- Department of Physiological Chemistry, University for Veterinary Medicine Hannover, Hanover, Germany.,Research Center for Emerging Infections and Zoonoses (RIZ), University for Veterinary Medicine Hannover, Hanover, Germany
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Kirker KR, James GA. In vitro studies evaluating the effects of biofilms on wound-healing cells: a review. APMIS 2017; 125:344-352. [PMID: 28407431 DOI: 10.1111/apm.12678] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 01/15/2017] [Indexed: 01/09/2023]
Abstract
Chronic wounds are characterized as wounds that have failed to proceed through the well-orchestrated healing process and have remained open for months to years. Open wounds are at risk for colonization by opportunistic pathogens. Bacteria that colonize the open wound bed form surface-attached, multicellular communities called biofilms, and chronic wound biofilms can contain a diverse microbiota. Investigators are just beginning to elucidate the role of biofilms in chronic wound pathogenesis, and have simplified the complex wound environment using in vitro models to obtain a fundamental understanding of the impact of biofilms on wound-healing cell types. The intent of this review is to describe current in vitro methodologies and their results. Investigations started with one host cell-type and single species biofilms and demonstrated that biofilms, or their secretions, had deleterious effects on wound-healing cells. More complex systems involved the use of multiple host cell/tissue types and single species biofilms. Using human skin-equivalent tissues, investigators demonstrated that a number of different species can grow on the tissue and elicit an inflammatory response from the tissue. A full understanding of how biofilms impact wound-healing cells and host tissues will have a profound effect on how chronic wounds are treated.
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Affiliation(s)
- Kelly R Kirker
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Garth A James
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
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Segal LN, Clemente JC, Li Y, Ruan C, Cao J, Danckers M, Morris A, Tapyrik S, Wu BG, Diaz P, Calligaro G, Dawson R, van Zyl-Smit RN, Dheda K, Rom WN, Weiden MD. Anaerobic Bacterial Fermentation Products Increase Tuberculosis Risk in Antiretroviral-Drug-Treated HIV Patients. Cell Host Microbe 2017; 21:530-537.e4. [PMID: 28366509 DOI: 10.1016/j.chom.2017.03.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/01/2017] [Accepted: 03/02/2017] [Indexed: 02/06/2023]
Abstract
Despite the immune-reconstitution with antiretroviral therapy (ART), HIV-infected individuals remain highly susceptible to tuberculosis (TB) and have an enrichment of oral anaerobes in the lung. Products of bacterial anaerobic metabolism, like butyrate and other short-chain fatty acids (SCFAs), induce regulatory T cells (Tregs). We tested whether SCFAs contribute to poor TB control in a longitudinal cohort of ART-treated HIV-infected South Africans. Increase in serum SCFAs was associated with increased TB susceptibility. SCFAs inhibited IFN-γ and IL-17A production in peripheral blood mononuclear cells from HIV-infected ART-treated individuals in response to M. tuberculosis antigen stimulation. Pulmonary SCFAs correlated with increased oral anaerobes, such as Prevotella in the lung, and with M. tuberculosis antigen-induced Tregs. Metabolites from anaerobic bacterial fermentation may, therefore, increase TB susceptibility by suppressing IFN-γ and IL-17A production during the cellular immune response to M. tuberculosis.
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Affiliation(s)
- Leopoldo N Segal
- Division of Pulmonary, Critical Care and Sleep Medicine, School of Medicine, New York University, New York, NY 10016, USA
| | - Jose C Clemente
- Icahn Institute for Genomics and Multiscale Biology, Department of Genetics and Genomic Sciences, and Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Yonghua Li
- Division of Pulmonary, Critical Care and Sleep Medicine, School of Medicine, New York University, New York, NY 10016, USA
| | - Chunhai Ruan
- Metabolomics Core, University of Michigan School of Medicine, Ann Arbor, MI 48105, USA
| | - Jane Cao
- Metabolomics Core, University of Michigan School of Medicine, Ann Arbor, MI 48105, USA
| | - Mauricio Danckers
- Division of Pulmonary, Critical Care and Sleep Medicine, School of Medicine, New York University, New York, NY 10016, USA
| | - Alison Morris
- Division of Pulmonary, Allergy, and Critical Care Medicine, Center for Medicine and the Microbiome, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Sarah Tapyrik
- Division of Pulmonary, Critical Care & Sleep Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Benjamin G Wu
- Division of Pulmonary, Critical Care and Sleep Medicine, School of Medicine, New York University, New York, NY 10016, USA
| | - Philip Diaz
- Division of Pulmonary, Critical Care & Sleep Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Gregory Calligaro
- Division of Pulmonology, Department of Medicine & UCT Lung Institute, University of Cape Town, Cape Town 7925, South Africa
| | - Rodney Dawson
- Division of Pulmonology, Department of Medicine & UCT Lung Institute, University of Cape Town, Cape Town 7925, South Africa
| | - Richard N van Zyl-Smit
- Division of Pulmonology, Department of Medicine & UCT Lung Institute, University of Cape Town, Cape Town 7925, South Africa
| | - Keertan Dheda
- Division of Pulmonology, Department of Medicine & UCT Lung Institute, University of Cape Town, Cape Town 7925, South Africa
| | - William N Rom
- Division of Pulmonary, Critical Care and Sleep Medicine, School of Medicine, New York University, New York, NY 10016, USA
| | - Michael D Weiden
- Division of Pulmonary, Critical Care and Sleep Medicine, School of Medicine, New York University, New York, NY 10016, USA.
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Hyperosmotic Agents and Antibiotics Affect Dissolved Oxygen and pH Concentration Gradients in Staphylococcus aureus Biofilms. Appl Environ Microbiol 2017; 83:AEM.02783-16. [PMID: 28062458 DOI: 10.1128/aem.02783-16] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/02/2017] [Indexed: 12/26/2022] Open
Abstract
Biofilms on wound surfaces are treated topically with hyperosmotic agents, such as medical-grade honey and cadexomer iodine; in some cases, these treatments are combined with antibiotics. Tissue repair requires oxygen, and a low pH is conducive to oxygen release from red blood cells and epithelialization. We investigated the variation of dissolved oxygen concentration and pH with biofilm depth and the variation in oxygen consumption rates when biofilms are challenged with medical-grade honey or cadexomer iodine combined with vancomycin or ciprofloxacin. Dissolved oxygen and pH depth profiles in Staphylococcus aureus biofilms were measured using microelectrodes. The presence of cadexomer iodine with vancomycin or ciprofloxacin on the surface of the biofilm permitted a measurable concentration of oxygen at greater biofilm depths (101.6 ± 27.3 μm, P = 0.02; and 155.5 ± 27.9 μm, P = 0.016, respectively) than in untreated controls (30.1 μm). Decreases in pH of ∼0.6 and ∼0.4 units were observed in biofilms challenged with medical-grade honey alone and combined with ciprofloxacin, respectively (P < 0.001 and 0.01, respectively); the number of bacteria recovered from biofilms was significantly reduced (1.26 log) by treatment with cadexomer iodine and ciprofloxacin (P = 0.002) compared to the untreated control. Combining cadexomer iodine and ciprofloxacin improved dissolved oxygen concentration and penetration depth into the biofilm, while medical-grade honey was associated with a lower pH; not all treatments established a bactericidal effect in the time frame used in the experiments.IMPORTANCE Reports about using hyperosmotic agents and antibiotics against wound biofilms focus mostly on killing bacteria, but the results of these treatments should additionally be considered in the context of how they affect physiologically important parameters, such as oxygen concentration and pH. We confirmed that the combination of a hyperosmotic agent and an antibiotic results in greater dissolved oxygen and reduced pH within an S. aureus biofilm.
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42
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Bernstein HC, Brislawn C, Renslow RS, Dana K, Morton B, Lindemann SR, Song HS, Atci E, Beyenal H, Fredrickson JK, Jansson JK, Moran JJ. Trade-offs between microbiome diversity and productivity in a stratified microbial mat. THE ISME JOURNAL 2017; 11:405-414. [PMID: 27801910 PMCID: PMC5270574 DOI: 10.1038/ismej.2016.133] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 07/26/2016] [Accepted: 08/05/2016] [Indexed: 11/08/2022]
Abstract
Productivity is a major determinant of ecosystem diversity. Microbial ecosystems are the most diverse on the planet yet very few relationships between diversity and productivity have been reported as compared with macro-ecological studies. Here we evaluated the spatial relationships of productivity and microbiome diversity in a laboratory-cultivated photosynthetic mat. The goal was to determine how spatial diversification of microorganisms drives localized carbon and energy acquisition rates. We measured sub-millimeter depth profiles of net primary productivity and gross oxygenic photosynthesis in the context of the localized microenvironment and community structure, and observed negative correlations between species richness and productivity within the energy-replete, photic zone. Variations between localized community structures were associated with distinct taxa as well as environmental profiles describing a continuum of biological niches. Spatial regions in the photic zone corresponding to high primary productivity and photosynthesis rates had relatively low-species richness and high evenness. Hence, this system exhibited negative species-productivity and species-energy relationships. These negative relationships may be indicative of stratified, light-driven microbial ecosystems that are able to be the most productive with a relatively smaller, even distributions of species that specialize within photic zones.
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Affiliation(s)
- Hans C Bernstein
- Chemical and Biological Signature Science, Pacific Northwest National Laboratory, Richland, WA, USA
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA
| | - Colin Brislawn
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Ryan S Renslow
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA
| | - Karl Dana
- Chemical and Biological Signature Science, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Beau Morton
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Stephen R Lindemann
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Hyun-Seob Song
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Erhan Atci
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA
| | - Haluk Beyenal
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA
| | - James K Fredrickson
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Janet K Jansson
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - James J Moran
- Chemical and Biological Signature Science, Pacific Northwest National Laboratory, Richland, WA, USA
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Gogoi-Tiwari J, Williams V, Waryah CB, Costantino P, Al-Salami H, Mathavan S, Wells K, Tiwari HK, Hegde N, Isloor S, Al-Sallami H, Mukkur T. Mammary Gland Pathology Subsequent to Acute Infection with Strong versus Weak Biofilm Forming Staphylococcus aureus Bovine Mastitis Isolates: A Pilot Study Using Non-Invasive Mouse Mastitis Model. PLoS One 2017; 12:e0170668. [PMID: 28129375 PMCID: PMC5271311 DOI: 10.1371/journal.pone.0170668] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 01/09/2017] [Indexed: 12/30/2022] Open
Abstract
Background Biofilm formation by Staphylococcus aureus is an important virulence attribute because of its potential to induce persistent antibiotic resistance, retard phagocytosis and either attenuate or promote inflammation, depending upon the disease syndrome, in vivo. This study was undertaken to evaluate the potential significance of strength of biofilm formation by clinical bovine mastitis-associated S. aureus in mammary tissue damage by using a mouse mastitis model. Methods Two S. aureus strains of the same capsular phenotype with different biofilm forming strengths were used to non-invasively infect mammary glands of lactating mice. Biofilm forming potential of these strains were determined by tissue culture plate method, ica typing and virulence gene profile per detection by PCR. Delivery of the infectious dose of S. aureus was directly through the teat lactiferous duct without invasive scraping of the teat surface. Both bacteriological and histological methods were used for analysis of mammary gland pathology of mice post-infection. Results Histopathological analysis of the infected mammary glands revealed that mice inoculated with the strong biofilm forming S. aureus strain produced marked acute mastitic lesions, showing profuse infiltration predominantly with neutrophils, with evidence of necrosis in the affected mammary glands. In contrast, the damage was significantly less severe in mammary glands of mice infected with the weak biofilm-forming S. aureus strain. Although both IL-1β and TNF-α inflammatory biomarkers were produced in infected mice, level of TNF-α produced was significantly higher (p<0.05) in mice inoculated with strong biofilm forming S. aureus than the weak biofilm forming strain. Conclusion This finding suggests an important role of TNF-α in mammary gland pathology post-infection with strong biofilm-forming S. aureus in the acute mouse mastitis model, and offers an opportunity for the development of novel strategies for reduction of mammary tissue damage, with or without use of antimicrobials and/or anti-inflammatory compounds for the treatment of bovine mastitis.
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Affiliation(s)
- Jully Gogoi-Tiwari
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
- College of Veterinary Sciences and Animal Husbandry, Central Agricultural University, Selesih, Aizawl, Mizoram, India
| | - Vincent Williams
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Charlene Babra Waryah
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
- Department of Medicine and Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Paul Costantino
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Hani Al-Salami
- School of Pharmacy, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Sangeetha Mathavan
- School of Pharmacy, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Kelsi Wells
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Harish Kumar Tiwari
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
| | | | - Shrikrishna Isloor
- Veterinary College, Karnataka Veterinary, Animal and Fisheries Sciences University, Bangalore, India
| | | | - Trilochan Mukkur
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
- * E-mail:
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Lodge KM, Thompson AAR, Chilvers ER, Condliffe AM. Hypoxic regulation of neutrophil function and consequences for Staphylococcus aureus infection. Microbes Infect 2016; 19:166-176. [PMID: 27789256 DOI: 10.1016/j.micinf.2016.10.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 10/07/2016] [Accepted: 10/12/2016] [Indexed: 01/22/2023]
Abstract
Staphylococcal infection and neutrophilic inflammation can act in concert to establish a profoundly hypoxic environment. In this review we summarise how neutrophils and Staphylococcus aureus are adapted to function under hypoxic conditions, with a particular focus on the impaired ability of hypoxic neutrophils to effect Staphylococcus aureus killing.
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Affiliation(s)
- Katharine M Lodge
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge University Hospitals, Hills Road, Cambridge, CB2 0QQ, UK
| | - A A Roger Thompson
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Edwin R Chilvers
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge University Hospitals, Hills Road, Cambridge, CB2 0QQ, UK.
| | - Alison M Condliffe
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Beech Hill Road, Sheffield, S10 2RX, UK
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Gel-Entrapped Staphylococcus aureus Bacteria as Models of Biofilm Infection Exhibit Growth in Dense Aggregates, Oxygen Limitation, Antibiotic Tolerance, and Heterogeneous Gene Expression. Antimicrob Agents Chemother 2016; 60:6294-301. [PMID: 27503656 DOI: 10.1128/aac.01336-16] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/03/2016] [Indexed: 11/20/2022] Open
Abstract
An experimental model that mimicked the structure and characteristics of in vivo biofilm infections, such as those occurring in the lung or in dermal wounds where no biomaterial surface is present, was developed. In these infections, microbial biofilm forms as cell aggregates interspersed in a layer of mucus or host matrix material. This structure was modeled by filling glass capillary tubes with an agarose gel that had been seeded with Staphylococcus aureus bacteria and then incubating the gel biofilm in medium for up to 30 h. Confocal microscopy showed that the bacteria formed in discrete pockets distributed throughout the gel matrix. These aggregates enlarged over time and also developed a size gradient, with the clusters being larger near the nutrient- and oxygen-supplied interface and smaller at greater depths. Bacteria entrapped in gels for 24 h grew slowly (specific growth rate, 0.06 h(-1)) and were much less susceptible to oxacillin, minocycline, or ciprofloxacin than planktonic cells. Microelectrode measurements showed that the oxygen concentration decreased with depth into the gel biofilm, falling to values less than 3% of air saturation at depths of 500 μm. An anaerobiosis-responsive green fluorescent protein reporter gene for lactate dehydrogenase was induced in the region of the gel where the measured oxygen concentrations were low, confirming biologically relevant hypoxia. These results show that the gel biofilm model captures key features of biofilm infection in mucus or compromised tissue: formation of dense, distinct aggregates, reduced specific growth rates, local hypoxia, and antibiotic tolerance.
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46
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Stewart PS, Zhang T, Xu R, Pitts B, Walters MC, Roe F, Kikhney J, Moter A. Reaction-diffusion theory explains hypoxia and heterogeneous growth within microbial biofilms associated with chronic infections. NPJ Biofilms Microbiomes 2016; 2:16012. [PMID: 28721248 PMCID: PMC5515263 DOI: 10.1038/npjbiofilms.2016.12] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 04/11/2016] [Accepted: 05/19/2016] [Indexed: 12/01/2022] Open
Abstract
Reaction–diffusion models were applied to gain insight into the aspects of biofilm infection and persistence by comparing mathematical simulations with the experimental data from varied bacterial biofilms. These comparisons, including three in vitro systems and two clinical investigations of specimens examined ex vivo, underscored the central importance of concentration gradients of metabolic substrates and the resulting physiological heterogeneity of the microorganisms. Relatively simple one-dimensional and two-dimensional (2D) models captured the: (1) experimentally determined distribution of specific growth rates measured in Pseudomonas aeruginosa cells within sputum from cystic fibrosis patients; (2) pattern of relative growth rate within aggregates of streptococcal biofilm harboured in an endocarditis vegetation; (3) incomplete penetration of oxygen into a Pseudomonas aeruginosa biofilm under conditions of exposure to ambient air and also pure oxygen; (4) localisation of anabolic activity around the periphery of P. aeruginosa cell clusters formed in a flow cell and attribution of this pattern to iron limitation; (5) very low specific growth rates, as small as 0.025 h−1, in the interior of cell clusters within a Klebsiella pneumoniae biofilm in a complex 2D domain of variable cell density.
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Affiliation(s)
- Philip S Stewart
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.,Chemical and Biological Engineering, Montana State University, Bozeman, MT, USA
| | - Tianyu Zhang
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.,Mathematical Sciences, Montana State University, Bozeman, MT, USA
| | - Ruifang Xu
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.,Chemical and Biological Engineering, Montana State University, Bozeman, MT, USA
| | - Betsey Pitts
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Marshall C Walters
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA.,Chemical and Biological Engineering, Montana State University, Bozeman, MT, USA
| | - Frank Roe
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Judith Kikhney
- Biofilmcenter, German Heart Institute Berlin, Berlin, Germany
| | - Annette Moter
- Biofilmcenter, German Heart Institute Berlin, Berlin, Germany
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47
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Song HS, Renslow RS, Fredrickson JK, Lindemann SR. Integrating Ecological and Engineering Concepts of Resilience in Microbial Communities. Front Microbiol 2015; 6:1298. [PMID: 26648912 PMCID: PMC4664643 DOI: 10.3389/fmicb.2015.01298] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 11/06/2015] [Indexed: 11/30/2022] Open
Abstract
Many definitions of resilience have been proffered for natural and engineered ecosystems, but a conceptual consensus on resilience in microbial communities is still lacking. We argue that the disconnect largely results from the wide variance in microbial community complexity, which range from compositionally simple synthetic consortia to complex natural communities, and divergence between the typical practical outcomes emphasized by ecologists and engineers. Viewing microbial communities as elasto-plastic systems that undergo both recoverable and unrecoverable transitions, we argue that this gap between the engineering and ecological definitions of resilience stems from their respective emphases on elastic and plastic deformation, respectively. We propose that the two concepts may be fundamentally united around the resilience of function rather than state in microbial communities and the regularity in the relationship between environmental variation and a community's functional response. Furthermore, we posit that functional resilience is an intrinsic property of microbial communities and suggest that state changes in response to environmental variation may be a key mechanism driving functional resilience in microbial communities.
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Affiliation(s)
- Hyun-Seob Song
- Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory Richland, WA, USA
| | - Ryan S Renslow
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, WA, USA
| | - Jim K Fredrickson
- Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory Richland, WA, USA
| | - Stephen R Lindemann
- Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory Richland, WA, USA
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48
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Sultana ST, Atci E, Babauta JT, Mohamed Falghoush A, Snekvik KR, Call DR, Beyenal H. Electrochemical scaffold generates localized, low concentration of hydrogen peroxide that inhibits bacterial pathogens and biofilms. Sci Rep 2015; 5:14908. [PMID: 26464174 PMCID: PMC4604468 DOI: 10.1038/srep14908] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 09/11/2015] [Indexed: 11/29/2022] Open
Abstract
We hypothesized that low concentrations of H2O2 could be generated through the electrochemical conversion of oxygen by applying an electric potential to a conductive scaffold and produce a low, but constant, concentration of H2O2 that would be sufficient to destroy biofilms. To test our hypothesis we used a multidrug-resistant Acinetobacter baumannii strain, because this species is often implicated in difficult-to-treat biofilm infections. We used conductive carbon fabric as the scaffold material ("e-scaffold"). In vitro experiments demonstrated the production of a maximum constant concentration of ~25 μM H2O2 near the e-scaffold surface. An e-scaffold was overlaid onto an existing A. baumannii biofilm, and within 24 h there was a ~4-log reduction in viable bacteria with an ~80% decrease in biofilm surface coverage. A similar procedure was used to overlay an e-scaffold onto an existing A. baumannii biofilm that was grown on a porcine explant. After 24 h, there was a ~3-log reduction in viable bacteria from the infected porcine explants with no observable damage to the underlying mammalian tissue based on a viability assay and histology. This research establishes a novel foundation for an alternative antibiotic-free wound dressing to eliminate biofilms.
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Affiliation(s)
- Sujala T. Sultana
- School of Chemical Engineering & Bioengineering, Washington State University, Pullman 99163, WA
| | - Erhan Atci
- School of Chemical Engineering & Bioengineering, Washington State University, Pullman 99163, WA
| | - Jerome T. Babauta
- School of Chemical Engineering & Bioengineering, Washington State University, Pullman 99163, WA
| | - Azeza Mohamed Falghoush
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman 99163, WA
| | - Kevin R. Snekvik
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman 99163, WA
- Washington Animal Disease Diagnostic Laboratory, Washington State University, Pullman 99163, WA
| | - Douglas R. Call
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman 99163, WA
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman 99163, WA
| | - Haluk Beyenal
- School of Chemical Engineering & Bioengineering, Washington State University, Pullman 99163, WA
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49
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Colonization of epidermal tissue by Staphylococcus aureus produces localized hypoxia and stimulates secretion of antioxidant and caspase-14 proteins. Infect Immun 2015; 83:3026-34. [PMID: 25987705 DOI: 10.1128/iai.00175-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/07/2015] [Indexed: 11/20/2022] Open
Abstract
A partial-thickness epidermal explant model was colonized with green fluorescent protein (GFP)-expressing Staphylococcus aureus, and the pattern of S. aureus biofilm growth was characterized using electron and confocal laser scanning microscopy. The oxygen concentration in explants was quantified using microelectrodes. The relative effective diffusivity and porosity of the epidermis were determined using magnetic resonance imaging, while hydrogen peroxide (H2O2) concentration in explant media was measured by using microelectrodes. Secreted proteins were identified and quantified using elevated-energy mass spectrometry (MS(E)). S. aureus biofilm grows predominantly in lipid-rich areas around hair follicles and associated skin folds. Dissolved oxygen was selectively depleted (2- to 3-fold) in these locations, but the relative effective diffusivity and porosity did not change between colonized and control epidermis. Histological analysis revealed keratinocyte damage across all the layers of colonized epidermis after 4 days of culture. The colonized explants released significantly (P < 0.01) more antioxidant proteins of both epidermal and S. aureus origin, consistent with elevated H2O2 concentrations found in the media from the colonized explants (P< 0.001). Caspase-14 was also elevated significantly in the media from the colonized explants. While H2O2 induces primary keratinocyte differentiation, caspase-14 is required for terminal keratinocyte differentiation and desquamation. These results are consistent with a localized biological impact from S. aureus in response to colonization of the skin surface.
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