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Kim D, Lee J, Shyaka C, Kwak JH, Pai H, Rho M, Ciufolini MA, Han M, Park JH, Kim YR, Jung S, Jang AR, Kim E, Lee JY, Lee H, Son YJ, Hwang HJ. Identification of Micrococcin P2-Derivatives as Antibiotic Candidates against Two Gram-Positive Pathogens. J Med Chem 2023; 66:14263-14277. [PMID: 37796116 DOI: 10.1021/acs.jmedchem.3c01309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
Thiopeptides exhibit potent antimicrobial activity against Gram-positive pathogens by inhibiting bacterial protein synthesis. Micrococcins are among the structurally simpler thiopeptides, but they have not been exploited in detail. This research involved a computational simulation of micrococcin P2 (MP2) docking in parallel with the structure-activity relationship (SAR) studied. The incorporation of particular nitrogen heterocycles in the side chain of MP2 enhances the antimicrobial activity. Micrococcin analogues 6c and 6d thus proved to be more effective against impetigo and C. difficile infection (CDI), respectively, as compared to current first-line treatments. Compound 6c also showed a shorter treatment period than that of a first-line treatment for impetigo. This may be attributed to its ability to downregulate pro-inflammatory cytokines. Compound 6d had no observed recurrence for C. difficile and exerted a minimal impact on the beneficial gut microbiome. Their pharmacokinetic properties and low toxicity profile make these compounds ideal candidates for the treatment of impetigo and CDI and validate their involvement in preclinical development.
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Affiliation(s)
- Dahyun Kim
- A&J Science Co., Ltd., 80 Chumbok Ro, Dong Gu, Daegu 41061, Republic of Korea
| | - Jusuk Lee
- A&J Science Co., Ltd., 80 Chumbok Ro, Dong Gu, Daegu 41061, Republic of Korea
| | - Clovis Shyaka
- A&J Science Co., Ltd., 80 Chumbok Ro, Dong Gu, Daegu 41061, Republic of Korea
| | - Jin-Hwan Kwak
- School of Life Science, Handong Global University, 558 Handong Ro, Heunghae-Eup, Buk-Gu, Pohang 37554, Republic of Korea
- Office of the President, Sunlin University, 30, 36 Chogok-gil, Heunghae-Eup, Buk-Gu, Pohang 37560, Republic of Korea
| | - Hyunjoo Pai
- Department of Internal Medicine, Hanyang University College of Medicine, 232 Wangsimri Ro, Seongdong-Gu, Seoul 04763, Republic of Korea
| | - Mina Rho
- Department of Computer Science, Hanyang University, 222 Wangsimri Ro, Seongdong-Gu, Seoul 04763, Republic of Korea
| | - Marco A Ciufolini
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6K 1Z1, Canada
| | - Minwoo Han
- New Drug Development Center, Daegu Gyeongbuk Medical Innovation Foundation, 80 Chumbok Ro, Dong Gu, Daegu 41061, Republic of Korea
| | - Jong-Hwan Park
- Laboratory Animal Medicine, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, 77 Yongbong-ro, Buk-Gu, Gwangju 61186, Republic of Korea
- Nodcure Inc., 77 Yongbong-ro, Buk-Gu, Gwangju 61186, Republic of Korea
| | - Young-Rok Kim
- School of Life Science, Handong Global University, 558 Handong Ro, Heunghae-Eup, Buk-Gu, Pohang 37554, Republic of Korea
| | - Sungji Jung
- School of Life Science, Handong Global University, 558 Handong Ro, Heunghae-Eup, Buk-Gu, Pohang 37554, Republic of Korea
| | - Ah-Ra Jang
- Nodcure Inc., 77 Yongbong-ro, Buk-Gu, Gwangju 61186, Republic of Korea
| | - Eunjung Kim
- School of Life Science, Handong Global University, 558 Handong Ro, Heunghae-Eup, Buk-Gu, Pohang 37554, Republic of Korea
| | - Jee-Young Lee
- New Drug Development Center, Daegu Gyeongbuk Medical Innovation Foundation, 80 Chumbok Ro, Dong Gu, Daegu 41061, Republic of Korea
| | - Hakyeong Lee
- A&J Science Co., Ltd., 80 Chumbok Ro, Dong Gu, Daegu 41061, Republic of Korea
| | - Young-Jin Son
- A&J Science Co., Ltd., 80 Chumbok Ro, Dong Gu, Daegu 41061, Republic of Korea
| | - Hee-Jong Hwang
- A&J Science Co., Ltd., 80 Chumbok Ro, Dong Gu, Daegu 41061, Republic of Korea
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A Staphylococcal Glucosaminidase Drives Inflammatory Responses by Processing Peptidoglycan Chains to Physiological Lengths. Infect Immun 2023; 91:e0050022. [PMID: 36715551 PMCID: PMC9933629 DOI: 10.1128/iai.00500-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The peptidoglycan of Staphylococcus aureus is a critical cell envelope constituent and virulence factor that subverts host immune defenses and provides protection against environmental stressors. Peptidoglycan chains of the S. aureus cell wall are processed to characteristically short lengths by the glucosaminidase SagB. It is well established that peptidoglycan is an important pathogen-associated molecular pattern (PAMP) that is recognized by the host innate immune system and promotes production of proinflammatory cytokines, including interleukin-1β (IL-1β). However, how bacterial processing of peptidoglycan drives IL-1β production is comparatively unexplored. Here, we tested the involvement of staphylococcal glucosaminidases in shaping innate immune responses and identified SagB as a mediator of IL-1β production. A ΔsagB mutant fails to promote IL-1β production by macrophages and dendritic cells, and processing of peptidoglycan by SagB is essential for this response. SagB-dependent IL-1β production by macrophages is independent of canonical pattern recognition receptor engagement and NLRP3 inflammasome-mediated caspase activity. Instead, treatment of macrophages with heat-killed cells from a ΔsagB mutant leads to reduced caspase-independent cleavage of pro-IL-1β, resulting in accumulation of the pro form in the macrophage cytosol. Furthermore, SagB is required for virulence in systemic infection and promotes IL-1β production in a skin and soft tissue infection model. Taken together, our results suggest that the length of S. aureus cell wall glycan chains can drive IL-1β production by innate immune cells through a previously undescribed mechanism related to IL-1β maturation.
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Daptomycin exerts differential immunomodulatory effects on host responses against methicillin-resistant Staphylococcus aureus biofilms. Int J Antimicrob Agents 2022; 60:106666. [PMID: 36038095 DOI: 10.1016/j.ijantimicag.2022.106666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 08/10/2022] [Accepted: 08/22/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND Daptomycin (DAP) is indicated for difficult-to-treat Gram-positive infections, especially those caused by methicillin-resistant S. aureus (MRSA). Exposure of S. aureus to sub-inhibitory concentrations (sub-MICs) of antibiotics have been shown to alter cell morphology or biofilm formation. OBJECTIVES To investigate the influence of DAP biofilm sub-MICs on the damage caused by human polymorphonuclear neutrophils (PMNs) against MRSA biofilms and the potential immunomodulatory activity of DAP on human monocytes (MNCs) exposed to MRSA biofilms. METHODS DAP activity against biofilms and the impact of DAP on the PMNs-induced biofilm damage were evaluated by the XTT reduction assay, whereas pathogen recognition, signal transduction and cytokine modulation of DAP on MNCs in response to MRSA biofilms were assessed by RT-PCR and ELISA methodology. RESULTS The MIC50 of DAP to MRSA biofilms was 16 to 32 mg/L. Pre-treatment of MRSA to 1, 2 or 4 mg/L DAP caused a synergistic effect on PMN-mediated biofilm damage, being dependent on the effector-to-target ratio. MNCs responded to MRSA biofilms and DAP through Toll like receptor 2 (TLR2) upregulation and increased NLRP3 inflammasome production. DAP caused 2.5-fold greater TLR2 mRNA levels than those caused by MRSA biofilms. A predominantly inflammatory response was induced by either component, causing the release of significantly increased IFN-γ, TNF-α, IL-8 and IL-6 levels by MNCs exposed to the combination treatment. MRSA biofilms alone or combined with DAP caused low amounts of IL-10 production, but increased IL-1β levels. CONCLUSIONS DAP may condition MNCs towards an inflammatory response through TLR2 engagement and NLRP3 inflammasome activation, possibly controlling biofilm-associated pathogenicity.
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von Köckritz-Blickwede M, Winstel V. Molecular Prerequisites for Neutrophil Extracellular Trap Formation and Evasion Mechanisms of Staphylococcus aureus. Front Immunol 2022; 13:836278. [PMID: 35237275 PMCID: PMC8884242 DOI: 10.3389/fimmu.2022.836278] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/19/2022] [Indexed: 12/15/2022] Open
Abstract
NETosis is a multi-facetted cellular process that promotes the formation of neutrophil extracellular traps (NETs). NETs as web-like structures consist of DNA fibers armed with granular proteins, histones, and microbicidal peptides, thereby exhibiting pathogen-immobilizing and antimicrobial attributes that maximize innate immune defenses against invading microbes. However, clinically relevant pathogens often tolerate entrapment and even take advantage of the remnants of NETs to cause persistent infections in mammalian hosts. Here, we briefly summarize how Staphylococcus aureus, a high-priority pathogen and causative agent of fatal diseases in humans as well as animals, catalyzes and concurrently exploits NETs during pathogenesis and recurrent infections. Specifically, we focus on toxigenic and immunomodulatory effector molecules produced by staphylococci that prime NET formation, and further highlight the molecular and underlying principles of suicidal NETosis compared to vital NET-formation by viable neutrophils in response to these stimuli. We also discuss the inflammatory potential of NET-controlled microenvironments, as excessive expulsion of NETs from activated neutrophils provokes local tissue injury and may therefore amplify staphylococcal disease severity in hospitalized or chronically ill patients. Combined with an overview of adaptation and counteracting strategies evolved by S. aureus to impede NET-mediated killing, these insights may stimulate biomedical research activities to uncover novel aspects of NET biology at the host-microbe interface.
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Affiliation(s)
- Maren von Köckritz-Blickwede
- Department of Biochemistry, University of Veterinary Medicine Hannover, Hannover, Germany
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, Hannover, Germany
| | - Volker Winstel
- Research Group Pathogenesis of Bacterial Infections, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Hannover Medical School and the Helmholtz Centre for Infection Research, Hannover, Germany
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
- *Correspondence: Volker Winstel,
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Rosman CWK, van Dijl JM, Sjollema J. Interactions between the foreign body reaction and Staphylococcus aureus biomaterial-associated infection. Winning strategies in the derby on biomaterial implant surfaces. Crit Rev Microbiol 2021; 48:624-640. [PMID: 34879216 DOI: 10.1080/1040841x.2021.2011132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Biomaterial-associated infections (BAIs) are an increasing problem where antibiotic therapies are often ineffective. The design of novel strategies to prevent or combat infection requires a better understanding of how an implanted foreign body prevents the immune system from eradicating surface-colonizing pathogens. The objective of this review is to chart factors resulting in sub-optimal clearance of Staphylococcus aureus bacteria involved in BAIs. To this end, we first describe three categories of bacterial mechanisms to counter the host immune system around foreign bodies: direct interaction with host cells, modulation of intercellular communication, and evasion of the immune system. These mechanisms take place in a time frame that differentiates sterile foreign body reactions, BAIs, and soft tissue infections. In addition, we identify experimental interventions in S. aureus BAI that may impact infectious mechanisms. Most experimental treatments modulate the host response to infection or alter the course of BAI through implant surface modulation. In conclusion, the first week after implantation and infection is crucial for the establishment of an S. aureus biofilm that resists the local immune reaction and antibiotic treatment. Although established and chronic S. aureus BAI is still treatable and manageable, the focus of interventions should lie on this first period.
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Affiliation(s)
- Colin W K Rosman
- Department of Biomedical Engineering, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Jelmer Sjollema
- Department of Biomedical Engineering, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
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6
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Abstract
Formation of microbial biofilms has long been implicated in the occurrence of periprosthetic joint infections (PJIs). Despite the widespread acknowledgment of the severity of these infections, much is still unknown regarding the underlying mechanisms of biofilm establishment and proliferation in the joint space. The presence of these resilient, complex communities poses many clinical challenges with respect to prevention, diagnosis, and treatment practices. Mature biofilms are known to be highly recalcitrant to antibiotic therapeutics as well as host immune system mediated clearance. A comprehensive understanding of biofilms in the unique joint environment at the molecular level will provide clinicians valuable insight into how best to combat them. As each stage in the process of biofilm establishment has the potential for clinical intervention, this review will provide a sequential analysis of the existing literature, following each step in the formation cycle. New insights into bacterial survival mechanisms from antimicrobial challenge and host immune defenses will be discussed. These new observations in the field may shed light on the early protection conferred upon entry into the joint space ultimately leading to the establishment of a mature biofilm. Additionally, standards of clinical diagnosis as well as current measures of prevention and treatment will be briefly discussed.
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Affiliation(s)
- Amelia Staats
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA.,Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Daniel Li
- Department of Orthopaedics, The Ohio State University, Columbus, Ohio, USA
| | - Anne C Sullivan
- Department of Orthopaedics, The Ohio State University, Columbus, Ohio, USA
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA.,Department of Orthopaedics, The Ohio State University, Columbus, Ohio, USA.,National Centre for Advanced Tribology at Southampton and National Biofilm Innovation Centre, Mechanical Engineering, University of Southampton, Southampton, UK
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7
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Tong S, Wang H, A LS, Bai TN, Gong JH, Jin WJ, Dai LL, Ba GN, Cho SB, Fu MH. Protective effect and mechanisms of action of Mongolian medicine Sulongga-4 on pyloric ligation-induced gastroduodenal ulcer in rats. World J Gastroenterol 2021; 27:1770-1784. [PMID: 33967556 PMCID: PMC8072194 DOI: 10.3748/wjg.v27.i16.1770] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/29/2021] [Accepted: 03/25/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Sulongga-4 (SL-4) is a herbal formula used in traditional Mongolian medical clinics for the treatment of peptic ulcers and gastroenteritis, even though its pharmacological mechanism has not been well characterized.
AIM To evaluate the protective effect and identify the mechanisms of action of SL-4 on gastroduodenal ulcer induced by pyloric ligation (PL) in rats.
METHODS PL was performed to induce gastric and duodenal ulcers in rats, which were then treated with oral SL-4 (1.3, 2.6, or 3.9 g/kg per day) for 15 d. PL-induced gastroduodenal ulceration. Therapeutic effects were characterized by pathological and histological evaluations and inflammatory indicators were analyzed by enzyme-linked immunosorbent assay. Microarray analyses were conducted to identify gene expression profiles of gastroduodenal tissue in PL rats with or without SL-4 treatment. The candidate target genes were selected and verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR).
RESULTS SL-4 decreased histopathological features in the PL-induced ulcerated rats. SL-4 significantly (P < 0.05) decreased expression of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, endotoxin, platelet-activating factor, and increased prostaglandin E2 and epidermal growth factor in ulcer tissue. Microarray analysis was used to identify a panel of candidate target genes for SL-4 acting on PL-induced ulceration. Genes included some complement and coagulation cascade and retinol metabolism pathways that are closely associated with inflammatory responses and gastric mucosal protective mechanisms. qRT-PCR showed that altered expression of the selected genes, such as CYP2b2, UGT2b1, A2m, and MASP1 was consistent with the microarray results.
CONCLUSION SL-4 exerts protective effects against PL-induced gastroduodenal ulcers via reducing inflammatory cytokines and elevating expression of gastric acid inhibitory factors. Downregulation of CYP2b2 and UGT2b1 genes in retinol metabolism and upregulation of A2m and MASP1 genes in the complement and coagulation cascades pathways are possibly involved in SL-4-mediated protection against gastroduodenal ulcer.
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Affiliation(s)
- Shan Tong
- School of Mongolian Medicine, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
- Mongolian Medicine Surgery Department, Affiliated Hospital of Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
| | - Huan Wang
- School of Mongolian Medicine, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
| | - Li-Sha A
- School of Mongolian Medicine, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
- Traditional Mongolian Medicine Research Institute, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
| | - Ta-Na Bai
- School of Mongolian Medicine, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
| | - Ju-Hua Gong
- School of Mongolian Medicine, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
| | - Wen-Jie Jin
- School of Mongolian Medicine, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
- Traditional Mongolian Medicine Research Institute, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
| | - Li-Li Dai
- School of Mongolian Medicine, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
- Traditional Mongolian Medicine Research Institute, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
| | - Gen-Na Ba
- School of Mongolian Medicine, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
| | - Sung-Bo Cho
- School of Mongolian Medicine, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
| | - Ming-Hai Fu
- School of Mongolian Medicine, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
- Traditional Mongolian Medicine Research Institute, Inner Mongolia University for Nationalities, Tongliao 028000, Inner Mongolia Autonomous Region, China
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Sauvat L, Abdul Hamid AI, Blavignac C, Josse J, Lesens O, Gueirard P. Biofilm-coated microbeads and the mouse ear skin: An innovative model for analysing anti-biofilm immune response in vivo. PLoS One 2020; 15:e0243500. [PMID: 33275636 PMCID: PMC7717515 DOI: 10.1371/journal.pone.0243500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 11/20/2020] [Indexed: 12/12/2022] Open
Abstract
Owing to its ability to form biofilms, Staphylococcus aureus is responsible for an increasing number of infections on implantable medical devices. The aim of this study was to develop a mouse model using microbeads coated with S. aureus biofilm to simulate such infections and to analyse the dynamics of anti-biofilm inflammatory responses by intravital imaging. Scanning electron microscopy and flow cytometry were used in vitro to study the ability of an mCherry fluorescent strain of S. aureus to coat silica microbeads. Biofilm-coated microbeads were then inoculated intradermally into the ear tissue of LysM-EGFP transgenic mice (EGFP fluorescent immune cells). General and specific real-time inflammatory responses were studied in ear tissue by confocal microscopy at early (4-6h) and late time points (after 24h) after injection. The displacement properties of immune cells were analysed. The responses were compared with those obtained in control mice injected with only microbeads. In vitro, our protocol was capable of generating reproducible inocula of biofilm-coated microbeads verified by labelling matrix components, observing biofilm ultrastructure and confirmed in vivo and in situ with a matrix specific fluorescent probe. In vivo, a major inflammatory response was observed in the mouse ear pinna at both time points. Real-time observations of cell recruitment at injection sites showed that immune cells had difficulty in accessing biofilm bacteria and highlighted areas of direct interaction. The average speed of cells was lower in infected mice compared to control mice and in tissue areas where direct contact between immune cells and bacteria was observed, the average cell velocity and linearity were decreased in comparison to cells in areas where no bacteria were visible. This model provides an innovative way to analyse specific immune responses against biofilm infections on medical devices. It paves the way for live evaluation of the effectiveness of immunomodulatory therapies combined with antibiotics.
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Affiliation(s)
- Léo Sauvat
- Laboratoire Microorganismes: Génome et Environnement, Université Clermont Auvergne, UMR CNRS 6023, Clermont-Ferrand, France.,Infectious and Tropical Diseases Department, CRIOA, CRMVT, CHU Clermont-Ferrand, Clermont-Ferrand, France
| | - Aizat Iman Abdul Hamid
- Laboratoire Microorganismes: Génome et Environnement, Université Clermont Auvergne, UMR CNRS 6023, Clermont-Ferrand, France
| | - Christelle Blavignac
- Centre Imagerie Cellulaire Santé, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Jérôme Josse
- CIRI-Centre International de Recherche en Infectiologie, Inserm, U1111, CNRS, UMR5308, École Normale Supérieure de Lyon, Université Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Olivier Lesens
- Laboratoire Microorganismes: Génome et Environnement, Université Clermont Auvergne, UMR CNRS 6023, Clermont-Ferrand, France.,Infectious and Tropical Diseases Department, CRIOA, CRMVT, CHU Clermont-Ferrand, Clermont-Ferrand, France
| | - Pascale Gueirard
- Laboratoire Microorganismes: Génome et Environnement, Université Clermont Auvergne, UMR CNRS 6023, Clermont-Ferrand, France
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9
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Arjunan A, Robinson J, Al Ani E, Heaselgrave W, Baroutaji A, Wang C. Mechanical performance of additively manufactured pure silver antibacterial bone scaffolds. J Mech Behav Biomed Mater 2020; 112:104090. [DOI: 10.1016/j.jmbbm.2020.104090] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/08/2020] [Accepted: 09/14/2020] [Indexed: 02/06/2023]
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10
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Gries CM, Rivas Z, Chen J, Lo DD. Intravital Multiphoton Examination of Implant-Associated Staphylococcus aureus Biofilm Infection. Front Cell Infect Microbiol 2020; 10:574092. [PMID: 33178628 PMCID: PMC7593243 DOI: 10.3389/fcimb.2020.574092] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 09/10/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial infections associated with implanted medical devices represents a healthcare crisis due to their persistence, antibiotic tolerance, and immune avoidance. Indwelling devices are rapidly coated with host plasma and extracellular matrix proteins which can then be exploited by bacterial pathogens for adherence and subsequent biofilm development. Our understanding of the host-pathogen interface that determines the fate of biofilm-mediated infections is limited to the experimental models employed by laboratories studying these organisms. Current in vivo models of biofilm-mediated infection, while certainly useful, are typically limited to end-point analyses of bacterial burden enumeration, immune cell profiling, and cytokine/chemokine analysis. Thus, with these models, the complex, real-time assessment of biofilm development and innate immune cell activity remains imperceptible. Here, we describe a novel murine biofilm infection model employing time-lapse intravital multiphoton microscopy which permits concurrent and real-time visualization of Staphylococcus aureus biofilm formation and immune cell activity. Using cell tracking, we found that S. aureus biofilms impede neutrophil chemotaxis, redirecting their migration patterns to prevent biofilm invasion. This approach is the first to directly examine device-associated biofilm development and host-pathogen interactions and will serve to both further our understanding of infection development and help reveal the effects of future antibiofilm treatment strategies.
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Affiliation(s)
- Casey M Gries
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Zuivanna Rivas
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Justin Chen
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - David D Lo
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
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11
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Chirathanamettu TR, Pawar PD. Quorum sensing-induced phenotypic switching as a regulatory nutritional stress response in a competitive two-species biofilm: An individual-based cellular automata model. J Biosci 2020. [DOI: 10.1007/s12038-020-00092-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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12
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Love AC, Prescher JA. Seeing (and Using) the Light: Recent Developments in Bioluminescence Technology. Cell Chem Biol 2020; 27:904-920. [PMID: 32795417 PMCID: PMC7472846 DOI: 10.1016/j.chembiol.2020.07.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/10/2020] [Accepted: 07/24/2020] [Indexed: 02/08/2023]
Abstract
Bioluminescence has long been used to image biological processes in vivo. This technology features luciferase enzymes and luciferin small molecules that produce visible light. Bioluminescent photons can be detected in tissues and live organisms, enabling sensitive and noninvasive readouts on physiological function. Traditional applications have focused on tracking cells and gene expression patterns, but new probes are pushing the frontiers of what can be visualized. The past few years have also seen the merger of bioluminescence with optogenetic platforms. Luciferase-luciferin reactions can drive light-activatable proteins, ultimately triggering signal transduction and other downstream events. This review highlights these and other recent advances in bioluminescence technology, with an emphasis on tool development. We showcase how new luciferins and engineered luciferases are expanding the scope of optical imaging. We also highlight how bioluminescent systems are being leveraged not just for sensing-but also controlling-biological processes.
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Affiliation(s)
- Anna C Love
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697, USA
| | - Jennifer A Prescher
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697, USA; Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA 92697, USA; Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, CA 92697, USA.
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13
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Abstract
PURPOSE OF REVIEW The human body plays host to bacterial biofilms across diverse anatomical sites. The treatment of pathogenic biofilm infection is confounded by their high rate of antibiotic resistance. Therefore, it is critical to understand the interplay between these biofilms and the host immune system to develop new tactics to combat these infections. RECENT FINDINGS Bacterial biofilms and the components they produce affect and are affected by the host immune system. Host anatomical sites represent distinct niches in which defined bacterial biofilms are able to form and interact with the host immune system. For persistent colonization to occur, the bacteria must either avoid or suppress the host immune system, or induce an immune response that facilitates their perpetuation. SUMMARY Commensal bacterial biofilms form a protective barrier against colonization by pathogens. Using similar mechanisms, bacteria modulate the immune system to orchestrate persistence and sometimes disease. Clinicians must balance the need to avoid disturbing beneficial commensal biofilms with the difficulty in preventing or treating pathogenic bacterial biofilms such as those that develop on medical implants and open wounds.
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Affiliation(s)
- Christina N Morra
- Department of Microbiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Characterisation of Classical Enterotoxins, Virulence Activity, and Antibiotic Susceptibility of Staphylococcus Aureus Isolated from Thai Fermented Pork Sausages, Clinical Samples, and Healthy Carriers in Northeastern Thailand. J Vet Res 2020; 64:289-297. [PMID: 32587917 PMCID: PMC7305643 DOI: 10.2478/jvetres-2020-0036] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 05/13/2020] [Indexed: 11/20/2022] Open
Abstract
Introduction Contamination by Staphylococcus aureus of food produced from animal sources may have diverse and multifactorial causes that depend on geographical distribution. The goal of this study was to isolate and characterise S. aureus strains from contaminated fermented pork sausage, which is a local food of northeastern Thailand. Material and Methods S. aureus strains were isolated from local pork sausage, and the presence of classical enterotoxins was determined by PCR and reversed passive latex agglutination. These results were compared with strains derived from hospitalised patients and healthy carriers. Additionally, production of extracellular enzymes and haemolysin, biofilm formation, and antibiotic susceptibility were assessed. Results S. aureus was identified in 36 sausage isolates (60%). The strains positive for staphylococcal enterotoxin A were more frequently found in isolates from sausage and healthy carriers than in those from patients. All tested S. aureus strains were positive for DNase, lipase, proteinase, haemolysin, and biofilm formation; notably, strains isolated from food and healthy carriers displayed similar values. Most isolates were resistant to penicillin and ampicillin, while none were to methicillin. Conclusions Thai fermented pork sausages are associated with a high risk of staphylococcal food poisoning, which may be linked to contamination caused by carriers. Dissemination of knowledge regarding best practices in sanitation and hygiene is important in local communities.
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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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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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