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Bhattacharya M, Horswill AR. The role of human extracellular matrix proteins in defining Staphylococcus aureus biofilm infections. FEMS Microbiol Rev 2024; 48:fuae002. [PMID: 38337187 PMCID: PMC10873506 DOI: 10.1093/femsre/fuae002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 01/26/2024] [Accepted: 02/07/2024] [Indexed: 02/12/2024] Open
Abstract
Twenty to forty one percent of the world's population is either transiently or permanently colonized by the Gram-positive bacterium, Staphylococcus aureus. In 2017, the CDC designated methicillin-resistant S. aureus (MRSA) as a serious threat, reporting ∼300 000 cases of MRSA-associated hospitalizations annually, resulting in over 19 000 deaths, surpassing that of HIV in the USA. S. aureus is a proficient biofilm-forming organism that rapidly acquires resistance to antibiotics, most commonly methicillin (MRSA). This review focuses on a large group of (>30) S. aureus adhesins, either surface-associated or secreted that are designed to specifically bind to 15 or more of the proteins that form key components of the human extracellular matrix (hECM). Importantly, this includes hECM proteins that are pivotal to the homeostasis of almost every tissue environment [collagen (skin), proteoglycans (lung), hemoglobin (blood), elastin, laminin, fibrinogen, fibronectin, and fibrin (multiple organs)]. These adhesins offer S. aureus the potential to establish an infection in every sterile tissue niche. These infections often endure repeated immune onslaught, developing into chronic, biofilm-associated conditions that are tolerant to ∼1000 times the clinically prescribed dose of antibiotics. Depending on the infection and the immune response, this allows S. aureus to seamlessly transition from colonizer to pathogen by subtly manipulating the host against itself while providing the time and stealth that it requires to establish and persist as a biofilm. This is a comprehensive discussion of the interaction between S. aureus biofilms and the hECM. We provide particular focus on the role of these interactions in pathogenesis and, consequently, the clinical implications for the prevention and treatment of S. aureus biofilm infections.
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Affiliation(s)
- Mohini Bhattacharya
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, United States
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, United States
- Department of Veterans Affairs, Eastern Colorado Health Care System, Aurora, CO 80045, United States
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Bové M, Kolpen M, Lichtenberg M, Bjarnsholt T, Coenye T. Adaptation of Pseudomonas aeruginosa biofilms to tobramycin and the quorum sensing inhibitor C-30 during experimental evolution requires multiple genotypic and phenotypic changes. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001278. [PMID: 36748633 PMCID: PMC9993117 DOI: 10.1099/mic.0.001278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In the present study we evaluated the fitness, antimicrobial susceptibility, metabolic activity, gene expression, in vitro production of virulence factors and in vivo virulence of experimentally evolved Pseudomonas aeruginosa PAO1. These strains were previously evolved in the presence of tobramycin and the quorum sensing inhibitor furanone C-30 (C-30) and carried mutations in mexT and fusA1. Compared to the wild-type (WT), the evolved strains show a different growth rate and different metabolic activity, suggesting they have an altered fitness. mexT mutants were less susceptible to C-30 than WT strains; they also show reduced susceptibility to chloramphenicol and ciprofloxacin, two substrates of the MexEF-OprN efflux pump. fusA1 mutants had a decreased susceptibility to aminoglycoside antibiotics, and an increased susceptibility to chloramphenicol. The decreased antimicrobial susceptibility and decreased susceptibility to C-30 was accompanied by a changed metabolic activity profile during treatment. The expression of mexE was significantly increased in mexT mutants and induced by C-30, suggesting that MexEF-OprN exports C-30 out of the bacterial cell. The in vitro production of virulence factors as well as virulence in two in vivo models of the strains evolved in the presence of C-30 was unchanged compared to the virulence of the WT. Finally, the evolved strains were less susceptible towards tobramycin (alone and combined with C-30) in an in vivo mouse model. In conclusion, this study shows that mutations acquired during experimental evolution of P. aeruginosa biofilms in the presence of tobramycin and C-30, are accompanied by an altered fitness, metabolism, mexE expression and in vitro and in vivo antimicrobial susceptibility.
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Affiliation(s)
- Mona Bové
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Mette Kolpen
- Department of Clinical Microbiology, Rigshospitalet, 2200 Copenhagen N, Denmark
| | - Mads Lichtenberg
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium.,Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
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The Skin Microbiome in Cutaneous T-Cell Lymphomas (CTCL)—A Narrative Review. Pathogens 2022; 11:pathogens11080935. [PMID: 36015055 PMCID: PMC9414712 DOI: 10.3390/pathogens11080935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/10/2022] [Accepted: 08/16/2022] [Indexed: 12/02/2022] Open
Abstract
In recent years, numerous studies have shown a significant role of the skin microbiome in the development and exacerbation of skin diseases. Cutaneous T-cell lymphomas (CTCL) are a group of malignancies primary involving skin, with unclear pathogenesis and etiology. As external triggers appear to contribute to chronic skin inflammation and the malignant transformation of T-cells, some microorganisms or dysbiosis may be involved in these processes. Recently, studies analyzing the skin microbiome composition and diversity have been willingly conducted in CTCL patients. In this review, we summarize currently available data on the skin microbiome in CTLC. We refer to a healthy skin microbiome and the contribution of microorganisms in the pathogenesis and progression of other skin diseases, focusing on atopic dermatitis and its similarities to CTCL. Moreover, we present information about the possible role of identified microorganisms in CTCL development and progression. Additionally, we summarize information about the involvement of Staphylococcus aureus in CTCL pathogenesis. This article also presents therapeutic options used in CTCL and discusses how they may influence the microbiome.
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Kohda K, Li X, Soga N, Nagura R, Duerna T, Nakajima S, Nakagawa I, Ito M, Ikeuchi A. An In Vitro Mixed Infection Model With Commensal and Pathogenic Staphylococci for the Exploration of Interspecific Interactions and Their Impacts on Skin Physiology. Front Cell Infect Microbiol 2021; 11:712360. [PMID: 34604106 PMCID: PMC8481888 DOI: 10.3389/fcimb.2021.712360] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 08/16/2021] [Indexed: 12/15/2022] Open
Abstract
The skin microbiota has been recognized to play an integral role in the physiology and pathology of the skin. The crosstalk between skin and the resident microbes has been extensively investigated using two-dimensional (2D) and three-dimensional (3D) cell cultures in vitro; however, skin colonization by multiple species and the effects of interspecific interactions on the structure and function of skin remains to be elucidated. This study reports the establishment of a mixed infection model, incorporating both commensal (Staphylococcus epidermidis) and pathogenic (Staphylococcus aureus) bacteria, based on a 3D human epidermal model. We observed that co-infecting the 3D epidermal model with S. aureus and S. epidermidis restricted the growth of S. aureus. In addition, S. aureus induced epidermal cytotoxicity, and the release of proinflammatory cytokines was attenuated by the S. aureus-S. epidermidis mixed infection model. S. epidermidis also inhibited the invasion of the deeper epidermis by S. aureus, eliciting protective effects on the integrity of the epidermal barrier. This 3D culture-based mixed infection model would be an effective replacement for existing animal models and 2D cell culture approaches for the evaluation of diverse biotic and abiotic factors involved in maintaining skin health.
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Affiliation(s)
- Katsunori Kohda
- Frontier Research Center, Toyota Motor Corporation, Toyota, Japan
| | - Xuan Li
- Frontier Research Center, Toyota Motor Corporation, Toyota, Japan
| | - Naoki Soga
- Frontier Research Center, Toyota Motor Corporation, Toyota, Japan
| | - Risa Nagura
- Frontier Research Center, Toyota Motor Corporation, Toyota, Japan
| | - Tie Duerna
- Department of Dermatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Saeko Nakajima
- Department of Dermatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Ichiro Nakagawa
- Department of Microbiology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Masakazu Ito
- Frontier Research Center, Toyota Motor Corporation, Toyota, Japan
| | - Akinori Ikeuchi
- Frontier Research Center, Toyota Motor Corporation, Toyota, Japan
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Vishwakarma P, Mitra S, Beuria T, Barik MR, Sahu SK. Comparative profile of ocular surface microbiome in vernal keratoconjunctivitis patients and healthy subjects. Graefes Arch Clin Exp Ophthalmol 2021; 259:1925-1933. [PMID: 33651203 DOI: 10.1007/s00417-021-05109-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 01/26/2021] [Accepted: 01/30/2021] [Indexed: 01/07/2023] Open
Abstract
PURPOSE To compare ocular surface microbiome and its antibiotic sensitivity in vernal keratoconjunctivitis (VKC) with normal ocular surface. METHODS In this case-control study, thirty patients each with clinical diagnosis of VKC and age-matched controls with normal ocular surface were enrolled. Tear film samples were collected from each group and subjected to microbial evaluation with microscopy, conventional culture methods, and polymerase chain reaction (PCR). Microbial diversity and antibiotic sensitivity patterns were analyzed. RESULTS Most patients (67%) belonged to severe grades (3 and 4) of VKC, and allergic history could be elicited in 20%. On culture, bacteria were isolated in 50% of VKC patients and 47% of control group. Staphylococcus species were identified in 70% VKC group and 57% control group. S. aureus growth was seen in 52% and 21% of VKC patients and controls, respectively. S. pneumoniae was isolated only in controls (29%) (p<0.05). Confluent colonies (≥10 colonies/μl) were seen in 70% of VKC patients and 14% of controls (p<0.05). Fluoroquinolone resistance was more among higher grades of VKC (50%) (p<0.01) and was observed in 46% of VKC patients and 23% of control group (p<0.01). Both groups were negative for HSV-1 DNA and fungal growth. CONCLUSION Staphylococcus, the most common ocular surface flora, was predominant in VKC patients. Microbial analysis revealed similar microbial diversity in both groups. However, bacterial load was higher in VKC. Increased fluoroquinolone resistance was observed in VKC patients with more resistance among higher grades. Fungi and HSV-1 were not seen in VKC or normal ocular surface.
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Affiliation(s)
- Pratima Vishwakarma
- Cornea & Anterior Segment Service, LV Prasad Eye Institute, Bhubaneswar, Odisha, India
| | - Sanchita Mitra
- Ocular Microbiology Service, LV Prasad Eye Institute, Bhubaneswar, Odisha, India
| | - Tushar Beuria
- Institute of Life Sciences, Bhubaneswar, Odisha, India
| | - Manas Ranjan Barik
- Ocular Microbiology Service, LV Prasad Eye Institute, Bhubaneswar, Odisha, India
| | - Srikant K Sahu
- Cornea & Anterior Segment Service, LV Prasad Eye Institute, Bhubaneswar, Odisha, India.
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Mirzaei R, Attar A, Papizadeh S, Jeda AS, Hosseini-Fard SR, Jamasbi E, Kazemi S, Amerkani S, Talei GR, Moradi P, Jalalifar S, Yousefimashouf R, Hossain MA, Keyvani H, Karampoor S. The emerging role of probiotics as a mitigation strategy against coronavirus disease 2019 (COVID-19). Arch Virol 2021; 166:1819-1840. [PMID: 33745067 PMCID: PMC7980799 DOI: 10.1007/s00705-021-05036-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/28/2021] [Indexed: 02/06/2023]
Abstract
COVID-19 is an acute respiratory infection accompanied by pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has affected millions of people globally. To date, there are no highly efficient therapies for this infection. Probiotic bacteria can interact with the gut microbiome to strengthen the immune system, enhance immune responses, and induce appropriate immune signaling pathways. Several probiotics have been confirmed to reduce the duration of bacterial or viral infections. Immune fitness may be one of the approaches by which protection against viral infections can be reinforced. In general, prevention is more efficient than therapy in fighting viral infections. Thus, probiotics have emerged as suitable candidates for controlling these infections. During the COVID-19 pandemic, any approach with the capacity to induce mucosal and systemic reactions could potentially be useful. Here, we summarize findings regarding the effectiveness of various probiotics for preventing virus-induced respiratory infectious diseases, especially those that could be employed for COVID-19 patients. However, the benefits of probiotics are strain-specific, and it is necessary to identify the bacterial strains that are scientifically established to be beneficial.
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Affiliation(s)
- Rasoul Mirzaei
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
- Student Research Committee, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Adeleh Attar
- Department of Microbiology and Virology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Saher Papizadeh
- Department of Microbiology and Virology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Ali Salimi Jeda
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Seyed Reza Hosseini-Fard
- Department of Clinical Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Elaheh Jamasbi
- Department of Anatomical Sciences, Kermanshah University of Medical Science, Kermanshah, Iran
| | - Sima Kazemi
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Saman Amerkani
- Department of Microbiology and Virology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Gholam Reza Talei
- Department of Virology, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Lorestan, Iran
| | - Pouya Moradi
- Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Saba Jalalifar
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Rasoul Yousefimashouf
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohammad Akhter Hossain
- The Florey University of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - Hossein Keyvani
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
- Gastrointestinal and Liver Diseases Research Center, Iran University of Medical Sciences, Tehran, Iran.
| | - Sajad Karampoor
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
- Gastrointestinal and Liver Diseases Research Center, Iran University of Medical Sciences, Tehran, Iran.
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Abstract
PURPOSE S. epidermidis is an ocular pathogen and a leading cause of keratitis. It produces hemolysins and at least 3 proteases. The purpose of the present study is to compare the secretion of hemolysins and proteases between 28 ocular isolates and one non-ocular strain and to determine their relationship to ocular virulence in selected strains using a rabbit model of infection. MATERIALS AND METHODS Culture supernatants were compared for protease production and hemolysis. Selected strains were injected into rabbit corneas and their virulence and pathology recorded. The major protease activity in a virulent strain was identified and the gene was cloned and expressed as a recombinant protein. The corneal toxicity of this protease was determined. Antibodies to the native protease were generated and tested for neutralizing activity in vivo and in vitro. The corneal pathology of the S. epidermidis protease was compared to the pathology of S. aureus V8 protease. RESULTS Strains that exhibited the least protease activity in vitro caused significantly less ocular pathology in vivo (p ≤ 0.003). Strains that were hemolytic and secreted a major protease had numerically higher SLE scores. This protease was identified as the serine protease Esp. The recombinant Esp protease caused extensive pathology when injected into the corneal stroma (7.62 ± 0.33). Antibody generated against native Esp did not neutralize the activity of the protease in vivo or in vitro. The antibody reacted with Esp proteases secreted by other S. epidermidis strains. S. epidermidis Esp protease and its homologue in S. aureus caused similar ocular pathology when injected in the rabbit corneal stroma. CONCLUSION Hemolysins and proteases seem to be important in corneal pathology caused by S. epidermidis infections. The Esp protease mediates significant corneal damage. S. epidermidis Esp and S. aureus V8 protease caused similar and extensive edema in rabbit corneas.
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Fournière M, Latire T, Souak D, Feuilloley MGJ, Bedoux G. Staphylococcus epidermidis and Cutibacterium acnes: Two Major Sentinels of Skin Microbiota and the Influence of Cosmetics. Microorganisms 2020; 8:E1752. [PMID: 33171837 PMCID: PMC7695133 DOI: 10.3390/microorganisms8111752] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/26/2020] [Accepted: 11/05/2020] [Indexed: 02/06/2023] Open
Abstract
Dermatological and cosmetics fields have recently started to focus on the human skin microbiome and microbiota, since the skin microbiota is involved in the health and dysbiosis of the skin ecosystem. Amongst the skin microorganisms, Staphylococcus epidermidis and Cutibacterium acnes, both commensal bacteria, appear as skin microbiota sentinels. These sentinels have a key role in the skin ecosystem since they protect and prevent microbiota disequilibrium by fighting pathogens and participate in skin homeostasis through the production of beneficial bacterial metabolites. These bacteria adapt to changing skin microenvironments and can shift to being opportunistic pathogens, forming biofilms, and thus are involved in common skin dysbiosis, such as acne or atopic dermatitis. The current evaluation methods for cosmetic active ingredient development are discussed targeting these two sentinels with their assets and limits. After identification of these objectives, research of the active cosmetic ingredients and products that maintain and promote these commensal metabolisms, or reduce their pathogenic forms, are now the new challenges of the skincare industry in correlation with the constant development of adapted evaluation methods.
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Affiliation(s)
- Mathilde Fournière
- Laboratoire de Biotechnologie et Chimie Marines LBCM EA 3884, IUEM, Université Bretagne Sud, 56000 Vannes, France; (T.L.); (G.B.)
- Laboratoire de Biotechnologie et Chimie Marines LBCM EA 3884, IUEM, Université Catholique de l’Ouest Bretagne Nord, 22200 Guingamp, France
| | - Thomas Latire
- Laboratoire de Biotechnologie et Chimie Marines LBCM EA 3884, IUEM, Université Bretagne Sud, 56000 Vannes, France; (T.L.); (G.B.)
- Laboratoire de Biotechnologie et Chimie Marines LBCM EA 3884, IUEM, Université Catholique de l’Ouest Bretagne Nord, 22200 Guingamp, France
| | - Djouhar Souak
- Laboratoire de Microbiologie Signaux et Microenvironment LMSM EA4312, Université de Rouen Normandie, 27000 Évreux, France; (D.S.); (M.G.J.F.)
- BASF Beauty Care Solutions France SAS, 69007 Lyon, France
| | - Marc G. J. Feuilloley
- Laboratoire de Microbiologie Signaux et Microenvironment LMSM EA4312, Université de Rouen Normandie, 27000 Évreux, France; (D.S.); (M.G.J.F.)
| | - Gilles Bedoux
- Laboratoire de Biotechnologie et Chimie Marines LBCM EA 3884, IUEM, Université Bretagne Sud, 56000 Vannes, France; (T.L.); (G.B.)
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Biofilms in Diabetic Foot Ulcers: Significance and Clinical Relevance. Microorganisms 2020; 8:microorganisms8101580. [PMID: 33066595 PMCID: PMC7602394 DOI: 10.3390/microorganisms8101580] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/07/2020] [Accepted: 10/11/2020] [Indexed: 12/14/2022] Open
Abstract
Foot infections are the main disabling complication in patients with diabetes mellitus. These infections can lead to lower-limb amputation, increasing mortality and decreasing the quality of life. Biofilm formation is an important pathophysiology step in diabetic foot ulcers (DFU)-it plays a main role in the disease progression and chronicity of the lesion, the development of antibiotic resistance, and makes wound healing difficult to treat. The main problem is the difficulty in distinguishing between infection and colonization in DFU. The bacteria present in DFU are organized into functionally equivalent pathogroups that allow for close interactions between the bacteria within the biofilm. Consequently, some bacterial species that alone would be considered non-pathogenic, or incapable of maintaining a chronic infection, could co-aggregate symbiotically in a pathogenic biofilm and act synergistically to cause a chronic infection. In this review, we discuss current knowledge on biofilm formation, its presence in DFU, how the diabetic environment affects biofilm formation and its regulation, and the clinical implications.
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The Protective Effect of Staphylococcus epidermidis Biofilm Matrix against Phage Predation. Viruses 2020; 12:v12101076. [PMID: 32992766 PMCID: PMC7601396 DOI: 10.3390/v12101076] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 09/13/2020] [Accepted: 09/22/2020] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus epidermidis is a major causative agent of nosocomial infections, mainly associated with the use of indwelling devices, on which this bacterium forms structures known as biofilms. Due to biofilms’ high tolerance to antibiotics, virulent bacteriophages were previously tested as novel therapeutic agents. However, several staphylococcal bacteriophages were shown to be inefficient against biofilms. In this study, the previously characterized S. epidermidis-specific Sepunavirus phiIBB-SEP1 (SEP1), which has a broad spectrum and high activity against planktonic cells, was evaluated concerning its efficacy against S. epidermidis biofilms. The in vitro biofilm killing assays demonstrated a reduced activity of the phage. To understand the underlying factors impairing SEP1 inefficacy against biofilms, this phage was tested against distinct planktonic and biofilm-derived bacterial populations. Interestingly, SEP1 was able to lyse planktonic cells in different physiological states, suggesting that the inefficacy for biofilm control resulted from the biofilm 3D structure and the protective effect of the matrix. To assess the impact of the biofilm architecture on phage predation, SEP1 was tested in disrupted biofilms resulting in a 2 orders-of-magnitude reduction in the number of viable cells after 6 h of infection. The interaction between SEP1 and the biofilm matrix was further assessed by the addition of matrix to phage particles. Results showed that the matrix did not inactivate phages nor affected phage adsorption. Moreover, confocal laser scanning microscopy data demonstrated that phage infected cells were less predominant in the biofilm regions where the matrix was more abundant. Our results provide compelling evidence indicating that the biofilm matrix can work as a barrier, allowing the bacteria to be hindered from phage infection.
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Abstract
The skin microbiome is rich in opportunities for novel therapeutics for skin diseases, and synthetic biology offers the advantage of providing novel functionality or therapeutic benefit to live biotherapeutic products. The development of novel bacterial strains whose growth can be controlled without the use of antibiotics or genetic elements conferring antibiotic resistance enables modulation of therapeutic exposure and improves safety. This study presents the design and in vitro evidence of a skin commensal whose growth can be controlled through d-alanine. The basis of this strain will support future clinical studies of this strain in humans. Using live microbes as therapeutic candidates is a strategy that has gained traction across multiple therapeutic areas. In the skin, commensal microorganisms play a crucial role in maintaining skin barrier function, homeostasis, and cutaneous immunity. Alterations of the homeostatic skin microbiome are associated with a number of skin diseases. Here, we present the design of an engineered commensal organism, Staphylococcus epidermidis, for use as a live biotherapeutic product (LBP) candidate for skin diseases. The development of novel bacterial strains whose growth can be controlled without the use of antibiotics or genetic elements conferring antibiotic resistance enables modulation of therapeutic exposure and improves safety. We therefore constructed an auxotrophic strain of S. epidermidis that requires exogenously supplied d-alanine. The S. epidermidis NRRL B-4268 Δalr1 Δalr2 Δdat strain (SEΔΔΔ) contains deletions of three biosynthetic genes: two alanine racemase genes, alr1 and alr2 (SE1674 and SE1079), and the d-alanine aminotransferase gene, dat (SE1423). These three deletions restricted growth in d-alanine-deficient medium, pooled human blood, and skin. In the presence of d-alanine, SEΔΔΔ colonized and increased expression of human β-defensin 2 in cultured human skin models in vitro. SEΔΔΔ showed a low propensity to revert to d-alanine prototrophy and did not form biofilms on plastic in vitro. These studies support the potential safety and utility of SEΔΔΔ as a live biotherapeutic strain whose growth can be controlled by d-alanine. IMPORTANCE The skin microbiome is rich in opportunities for novel therapeutics for skin diseases, and synthetic biology offers the advantage of providing novel functionality or therapeutic benefit to live biotherapeutic products. The development of novel bacterial strains whose growth can be controlled without the use of antibiotics or genetic elements conferring antibiotic resistance enables modulation of therapeutic exposure and improves safety. This study presents the design and in vitro evidence of a skin commensal whose growth can be controlled through d-alanine. The basis of this strain will support future clinical studies of this strain in humans.
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12
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Welp AL, Bomberger JM. Bacterial Community Interactions During Chronic Respiratory Disease. Front Cell Infect Microbiol 2020; 10:213. [PMID: 32477966 PMCID: PMC7240048 DOI: 10.3389/fcimb.2020.00213] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/20/2020] [Indexed: 12/21/2022] Open
Abstract
Chronic respiratory diseases including chronic rhinosinusitis, otitis media, asthma, cystic fibrosis, non-CF bronchiectasis, and chronic obstructive pulmonary disease are a major public health burden. Patients suffering from chronic respiratory disease are prone to persistent, debilitating respiratory infections due to the decreased ability to clear pathogens from the respiratory tract. Such infections often develop into chronic, life-long complications that are difficult to treat with antibiotics due to the formation of recalcitrant biofilms. The microbial communities present in the upper and lower respiratory tracts change as these respiratory diseases progress, often becoming less diverse and dysbiotic, correlating with worsening patient morbidity. Those with chronic respiratory disease are commonly infected with a shared group of respiratory pathogens including Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, and Moraxella catarrhalis, among others. In order to understand the microbial landscape of the respiratory tract during chronic disease, we review the known inter-species interactions among these organisms and other common respiratory flora. We consider both the balance between cooperative and competitive interactions in relation to microbial community structure. By reviewing the major causes of chronic respiratory disease, we identify common features across disease states and signals that might contribute to community shifts. As microbiome shifts have been associated with respiratory disease progression, worsening morbidity, and increased mortality, these underlying community interactions likely have an impact on respiratory disease state.
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Affiliation(s)
- Allison L. Welp
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, United States
- Graduate Program in Microbiology and Immunology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jennifer M. Bomberger
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, United States
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Wang N, Sadiq FA, Li S, He G, Yuan L. Tandem mass tag-based quantitative proteomics reveals the regulators in biofilm formation and biofilm control of Bacillus licheniformis. Food Control 2020. [DOI: 10.1016/j.foodcont.2019.107029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Hermansen GMM, Sazinas P, Kofod D, Millard A, Andersen PS, Jelsbak L. Transcriptomic profiling of interacting nasal staphylococci species reveals global changes in gene and non-coding RNA expression. FEMS Microbiol Lett 2019; 365:4794939. [PMID: 29325106 DOI: 10.1093/femsle/fny004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/08/2018] [Indexed: 12/14/2022] Open
Abstract
Interspecies interactions between bacterial pathogens and the commensal microbiota can influence disease outcome. In the nasal cavities, Staphylococcus epidermidis has been shown to be a determining factor for Staphylococcus aureus colonization and biofilm formation. However, the interaction between S. epidermidis and S. aureus has mainly been described by phenotypic analysis, and little is known about how this interaction modulates gene expression. This study aimed to determine the interactome of nasal S. aureus and S. epidermidis isolates to understand the molecular effect of interaction. After whole-genome sequencing of two nasal staphylococcal isolates, an agar-based RNA sequencing setup was utilized to identify interaction-induced transcriptional alterations in surface-associated populations. Our results revealed differential expression of several virulence genes in both species. We also identified putative non-coding RNAs (ncRNAs) and, interestingly, detected a putative ncRNA transcribed antisense to esp, the serine protease of S. epidermidis, that has previously been shown to inhibit nasal colonization of S. aureus. In our study, the gene encoding Esp and the antisense ncRNA are both downregulated during interaction with S. aureus. Our findings contribute to a better understanding of pathogen physiology in the context of interactions with the commensal microbiota, and may provide targets for future therapeutics.
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Affiliation(s)
- Grith M M Hermansen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kgs Lyngby, Denmark
| | - Pavelas Sazinas
- Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kgs Lyngby, Denmark
| | - Ditte Kofod
- Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kgs Lyngby, Denmark
| | - Andrew Millard
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 7RH, UK
| | - Paal Skytt Andersen
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Lars Jelsbak
- Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kgs Lyngby, Denmark
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15
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Vandeplassche E, Sass A, Lemarcq A, Dandekar AA, Coenye T, Crabbé A. In vitro evolution of Pseudomonas aeruginosa AA2 biofilms in the presence of cystic fibrosis lung microbiome members. Sci Rep 2019; 9:12859. [PMID: 31492943 PMCID: PMC6731285 DOI: 10.1038/s41598-019-49371-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 08/20/2019] [Indexed: 01/16/2023] Open
Abstract
In cystic fibrosis (CF) airways, the opportunistic pathogen Pseudomonas aeruginosa evolves from an acute to a chronic infection phenotype. Yet, the in vivo factors influencing the evolutionary trajectory of P. aeruginosa are poorly understood. This study aimed at understanding the role of the CF lung microbiome in P. aeruginosa evolution. Therefore, we investigated the in vitro biofilm evolution of an early CF P. aeruginosa isolate, AA2, in the presence or absence of a synthetic CF lung microbiome. Whole genome sequencing of evolved populations revealed mutations in quorum sensing (QS) genes (lasR, pqsR) with and without the microbiome. Phenotypic assays confirmed decreased production of the QS molecule 3-O-C12-homoserine lactone, and QS-regulated virulence factors pyocyanin and protease. Furthermore, a mixture of lasR and lasR pqsR mutants was found, in which double mutants showed less pyocyanin and protease production than lasR mutants. While the microbial community did not influence the production of the tested P. aeruginosa virulence factors, we observed a trend towards more mutations in the transcriptional regulators gntR and mexL when P. aeruginosa was grown alone. P. aeruginosa developed resistance to β-lactam antibiotics during evolution, when grown with and without the microbiome. In conclusion, in an experimental biofilm environment, the early P. aeruginosa CF isolate AA2 evolves towards a CF-like genotype and phenotype, and most studied evolutionary adaptations are not impacted by CF microbiome members.
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Affiliation(s)
- Eva Vandeplassche
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Andrea Sass
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Astrid Lemarcq
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Ajai A Dandekar
- Department of Medicine/Department of Microbiology, University of Washington, Washington, USA
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Aurélie Crabbé
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium.
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16
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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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17
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Bacterial Colonization of the Hospitalized Newborn: Competition Between Staphylococcus aureus and Staphylococcus epidermidis. Pediatr Infect Dis J 2019; 38:682-686. [PMID: 30985510 PMCID: PMC6814272 DOI: 10.1097/inf.0000000000002285] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND In adults, Staphylococcus epidermidis and Staphylococcus aureus compete for colonization of the nasal mucosa and S. epidermidis strains that produce the Esp serine protease eradicate S. aureus nasal colonization. Whether similar phenomena are seen in newborn infants is unknown. METHODS Nasal swabs were obtained on admission and discharge from newborn infants (n = 90 and 83, respectively) in the neonatal intensive care unit at UC Davis Children's Hospital. Swabs were cultured for S. aureus and S. epidermidis. S. epidermidis isolates were tested for Esp expression, overall secreted protease activity and biofilm inhibition. RESULTS No infant had S. aureus on admission. S. epidermidis colonization was rare on admission in inborn infants (2.5%), but common in infants transferred from referring hospitals (50%). At discharge, most infants (96%) were colonized by staphylococci. S. aureus colonization was less common in infants with S. epidermidis colonization (9%) and more common in infants without S. epidermidis (77%) (relative risk of S. aureus colonization in infants colonized with S. epidermidis 0.18, 95% confidence interval: 0.089-0.34, P < 0.0001). Compared with S. epidermidis strains from infants without S. aureus, S. epidermidis from infants co-colonized with S. aureus had lower total proteolytic enzyme activity and decreased biofilm inhibition capacity, but did not have lower frequency of Esp positivity. CONCLUSIONS In hospitalized neonates, S. epidermidis colonization has a protective effect against S. aureus colonization. Secretion of proteases by S. epidermidis is a possible mechanism of inhibition of S. aureus colonization; however, in this cohort of neonates, the source of major protease activity is likely other than Esp.
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18
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Kabanov D, Khabipova N, Valeeva L, Sharipova M, Rogov A, Kuznetsova S, Abaseva I, Mardanova A. Effect of Subtilisin-like Proteinase of Bacillus pumilus 3–19 on Pseudomonas aeruginosa Biofilms. BIONANOSCIENCE 2019. [DOI: 10.1007/s12668-019-00617-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Blicharz L, Rudnicka L, Samochocki Z. Staphylococcus aureus: an underestimated factor in the pathogenesis of atopic dermatitis? Postepy Dermatol Alergol 2019; 36:11-17. [PMID: 30858773 PMCID: PMC6409874 DOI: 10.5114/ada.2019.82821] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 07/11/2018] [Indexed: 12/29/2022] Open
Abstract
Atopic dermatitis is a common, recurrent pruritic dermatosis with a complex pathogenesis. It has been associated with disordered patterns of immunological response and impaired epithelial barrier integrity. These features predispose the patients to robust colonization of skin lesions by Staphylococcus aureus. Virulence factors of S. aureus (e.g. superantigens, α- and δ-toxin, protein A) have been shown to exacerbate and perpetuate the course of atopic dermatitis. Novel therapeutic options with potential for restoring natural microbiome composition are being elaborated and may enter clinical practice in the future.
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Affiliation(s)
- Leszek Blicharz
- Department of Dermatology, Medical University of Warsaw, Warsaw, Poland
| | - Lidia Rudnicka
- Department of Dermatology, Medical University of Warsaw, Warsaw, Poland
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20
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Zhang Y, Sass A, Van Acker H, Wille J, Verhasselt B, Van Nieuwerburgh F, Kaever V, Crabbé A, Coenye T. Coumarin Reduces Virulence and Biofilm Formation in Pseudomonas aeruginosa by Affecting Quorum Sensing, Type III Secretion and C-di-GMP Levels. Front Microbiol 2018; 9:1952. [PMID: 30186266 PMCID: PMC6110822 DOI: 10.3389/fmicb.2018.01952] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 08/02/2018] [Indexed: 01/09/2023] Open
Abstract
As one of the major pathogens in wound infections, Pseudomonas aeruginosa produces several virulence factors and forms biofilms; these processes are under the regulation of various quorum sensing (QS) systems. Therefore, QS has been regarded as a promising target to treat P. aeruginosa infections. In the present study, we evaluated the effect of the plant-derived QS inhibitor coumarin on P. aeruginosa biofilms and virulence. Coumarin inhibited QS in the P. aeruginosa QSIS2 biosensor strain, reduced protease and pyocyanin production, and inhibited biofilm formation in microtiter plates in different P. aeruginosa strains. The effects of coumarin in inhibiting biofilm formation in an in vitro wound model and reducing P. aeruginosa virulence in the Lucilia sericata infection model were strain-dependent. Transcriptome analysis revealed that several key genes involved in the las, rhl, Pseudomonas quinolone signal (PQS), and integrated QS (IQS) systems were downregulated in coumarin-treated biofilms of P. aeruginosa PAO1. Coumarin also changed the expression of genes related to type III secretion and cyclic diguanylate (c-di-GMP) metabolism. The cellular c-di-GMP level of P. aeruginosa PAO1 and recent clinical P. aeruginosa strains was significantly reduced by coumarin. These results provide new evidence for the possible application of coumarin as an anti-biofilm and anti-virulence agent against P. aeruginosa in wound infections.
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Affiliation(s)
- Yunhui Zhang
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Andrea Sass
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Heleen Van Acker
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Jasper Wille
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Bruno Verhasselt
- Department of Medical Microbiology, Ghent University Hospital, Ghent, Belgium
| | | | - Volkhard Kaever
- Research Core Unit Metabolomics, Institute of Pharmacology, Hannover Medical School, Hanover, Germany
| | - Aurélie Crabbé
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
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21
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De Rudder C, Calatayud Arroyo M, Lebeer S, Van de Wiele T. Modelling upper respiratory tract diseases: getting grips on host-microbe interactions in chronic rhinosinusitis using in vitro technologies. MICROBIOME 2018; 6:75. [PMID: 29690931 PMCID: PMC5913889 DOI: 10.1186/s40168-018-0462-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/17/2018] [Indexed: 05/27/2023]
Abstract
Chronic rhinosinusitis (CRS) is a chronic inflammation of the mucosa of the nose and paranasal sinuses affecting approximately 11% of the adult population in Europe. Inadequate immune responses, as well as a dysbiosis of the sinonasal microbiota, have been put forward as aetiological factors of the disease. However, despite the prevalence of this disease, there is no consensus on the aetiology and mechanisms of pathogenesis of CRS. Further research requires in vitro models mimicking the healthy and diseased host environment along with the sinonasal microbiota. This review aims to provide an overview of CRS model systems and proposes in vitro modelling strategies to conduct mechanistic research in an ecological framework on the sinonasal microbiota and its interactions with the host in health and CRS.
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Affiliation(s)
- Charlotte De Rudder
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium
| | - Marta Calatayud Arroyo
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium
| | - Sarah Lebeer
- Research Group of Environmental Ecology and Applied Microbiology, Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium
| | - Tom Van de Wiele
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium.
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22
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Lopez CA, Skaar EP. Crossed Wires: Interspecies Interference Blocks Pathogen Colonization. Cell Host Microbe 2018; 22:721-723. [PMID: 29241035 DOI: 10.1016/j.chom.2017.11.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Commensal bacteria protect against invading pathogens using many strategies. In this issue of Cell Host & Microbe, Paharik et al. (2017) find that a commensal blocks Staphylococcus aureus colonization by producing a signal to shut down virulence.
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Affiliation(s)
- Christopher A Lopez
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.
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23
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Martínez-García S, Rodríguez-Martínez S, Cancino-Diaz ME, Cancino-Diaz JC. Extracellular proteases of Staphylococcus epidermidis: roles as virulence factors and their participation in biofilm. APMIS 2018; 126:177-185. [PMID: 29399876 DOI: 10.1111/apm.12805] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 11/15/2017] [Indexed: 01/22/2023]
Abstract
Staphylococci produce a large number of extracellular proteases, some of which are considered as potential virulence factors. Staphylococcus epidermidis is a causative agent of nosocomial infections in medical devices by the formation of biofilms. It has been proposed that proteases contribute to the different stages of biofilm formation. S. epidermidis secretes a small number of extracellular proteases, such as serine protease Esp, cysteine protease EcpA, and metalloprotease SepA that have a relatively low substrate specificity. Recent findings indicate a significant contribution of extracellular proteases in biofilm formation through the proteolytic inactivation of adhesion molecules. The objective of this work is to provide an overview of the current knowledge of S. epidermidis' extracellular proteases during pathogenicity, especially in the different stages of biofilm formation.
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Affiliation(s)
- Sergio Martínez-García
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Sandra Rodríguez-Martínez
- Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Mario E Cancino-Diaz
- Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Juan C Cancino-Diaz
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
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24
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Chiu L, Bazin T, Truchetet ME, Schaeverbeke T, Delhaes L, Pradeu T. Protective Microbiota: From Localized to Long-Reaching Co-Immunity. Front Immunol 2017; 8:1678. [PMID: 29270167 PMCID: PMC5725472 DOI: 10.3389/fimmu.2017.01678] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 11/15/2017] [Indexed: 12/17/2022] Open
Abstract
Resident microbiota do not just shape host immunity, they can also contribute to host protection against pathogens and infectious diseases. Previous reviews of the protective roles of the microbiota have focused exclusively on colonization resistance localized within a microenvironment. This review shows that the protection against pathogens also involves the mitigation of pathogenic impact without eliminating the pathogens (i.e., “disease tolerance”) and the containment of microorganisms to prevent pathogenic spread. Protective microorganisms can have an impact beyond their niche, interfering with the entry, establishment, growth, and spread of pathogenic microorganisms. More fundamentally, we propose a series of conceptual clarifications in support of the idea of a “co-immunity,” where an organism is protected by both its own immune system and components of its microbiota.
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Affiliation(s)
- Lynn Chiu
- University of Bordeaux, CNRS, ImmunoConcept, UMR 5164, Bordeaux, France
| | - Thomas Bazin
- University of Bordeaux, INRA, Mycoplasmal and Chlamydial Infections in Humans, EA 3671, Bordeaux, France.,Department of Hepato-Gastroenterology, Bordeaux Hospital University Center, Pessac, France
| | | | - Thierry Schaeverbeke
- University of Bordeaux, INRA, Mycoplasmal and Chlamydial Infections in Humans, EA 3671, Bordeaux, France.,Department of Rheumatology, Bordeaux Hospital University Center, Bordeaux, France
| | - Laurence Delhaes
- Department of Parasitology and Mycology, Bordeaux Hospital University Center, Bordeaux, France.,University of Bordeaux, INSERM, Cardio-Thoracic Research Centre of Bordeaux, U1045, Bordeaux, France
| | - Thomas Pradeu
- University of Bordeaux, CNRS, ImmunoConcept, UMR 5164, Bordeaux, France
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25
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Lindsay S, Oates A, Bourdillon K. The detrimental impact of extracellular bacterial proteases on wound healing. Int Wound J 2017; 14:1237-1247. [PMID: 28745010 DOI: 10.1111/iwj.12790] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/13/2017] [Accepted: 06/15/2017] [Indexed: 12/13/2022] Open
Abstract
In addition to clinical signs of infection (e.g. inflammation, purulence and pain), a microbial count of ≥105 colony-forming units/g has historically been used to define wound infection. However, it is increasingly recognised that, rather than a high bioburden level alone being detrimental to wound healing, it is the virulence of the invading microorganism and the host's immune status that can affect clinical outcomes. Bacteria, such as Pseudomonas aeruginosa, Staphylococcus aureus and Staphylococcus epidermidis, have developed a range of virulence factors to help them overcome host defences and proliferate within the underlying soft tissue. More specifically, bacterial proteases are one such virulence factor that has been implicated in promoting the invasion and destruction of the host tissue. Because of the complexities of microorganisms, the proteases can negatively impact the wound environment, leading to delayed wound healing. The aim of the present paper is to describe various extracellular bacterial proteases; review the impact they have on the wound environment, the host immune response and biofilms; and discuss potential wound management strategies against them. The evidence discussed suggests that proteases may play a profound role in wound infections, contribute to the development of an inflammatory response and impede wound healing.
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Affiliation(s)
- Sharon Lindsay
- Research & Development Department, Systagenix, Gargrave, UK
| | - Angela Oates
- School of Pharmacy and Pharmaceutical Sciences, The University of Manchester, Manchester, UK
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26
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Guilhen C, Forestier C, Balestrino D. Biofilm dispersal: multiple elaborate strategies for dissemination of bacteria with unique properties. Mol Microbiol 2017; 105:188-210. [PMID: 28422332 DOI: 10.1111/mmi.13698] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2017] [Indexed: 01/22/2023]
Abstract
In most environments, microorganisms evolve in a sessile mode of growth, designated as biofilm, which is characterized by cells embedded in a self-produced extracellular matrix. Although a biofilm is commonly described as a "cozy house" where resident bacteria are protected from aggression, bacteria are able to break their biofilm bonds and escape to colonize new environments. This regulated process is observed in a wide variety of species; it is referred to as biofilm dispersal, and is triggered in response to various environmental and biological signals. The first part of this review reports the main regulatory mechanisms and effectors involved in biofilm dispersal. There is some evidence that dispersal is a necessary step between the persistence of bacteria inside biofilm and their dissemination. In the second part, an overview of the main methods used so far to study the dispersal process and to harvest dispersed bacteria was provided. Then focus was on the properties of the biofilm-dispersed bacteria and the fundamental role of the dispersal process in pathogen dissemination within a host organism. In light of the current body of knowledge, it was suggested that dispersal acts as a potent means of disseminating bacteria with enhanced colonization properties in the surrounding environment.
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Affiliation(s)
- Cyril Guilhen
- Laboratoire Microorganismes : Génome et Environnement, UMR CNRS 6023, Université Clermont Auvergne, Clermont Ferrand, F-63001, France
| | - Christiane Forestier
- Laboratoire Microorganismes : Génome et Environnement, UMR CNRS 6023, Université Clermont Auvergne, Clermont Ferrand, F-63001, France
| | - Damien Balestrino
- Laboratoire Microorganismes : Génome et Environnement, UMR CNRS 6023, Université Clermont Auvergne, Clermont Ferrand, F-63001, France
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27
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Metabolic activity, urease production, antibiotic resistance and virulence in dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus. PLoS One 2017; 12:e0172700. [PMID: 28263995 PMCID: PMC5338783 DOI: 10.1371/journal.pone.0172700] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 02/08/2017] [Indexed: 01/31/2023] Open
Abstract
In this paper, the metabolic activity in single and dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus isolates was investigated. Our results demonstrated that there was less metabolic activity in dual species biofilms compared to S. aureus biofilms. However, this was not observed if S. aureus and S. epidermidis were obtained from the same sample. The largest effect on metabolic activity was observed in biofilms of S. aureus Mu50 and S. epidermidis ET-024. A transcriptomic analysis of these dual species biofilms showed that urease genes and genes encoding proteins involved in metabolism were downregulated in comparison to monospecies biofilms. These results were subsequently confirmed by phenotypic assays. As metabolic activity is related to acid production, the pH in dual species biofilms was slightly higher compared to S. aureus Mu50 biofilms. Our results showed that S. epidermidis ET-024 in dual species biofilms inhibits metabolic activity of S. aureus Mu50, leading to less acid production. As a consequence, less urease activity is required to compensate for low pH. Importantly, this effect was biofilm-specific. Also S. aureus Mu50 genes encoding virulence-associated proteins (Spa, SplF and Dps) were upregulated in dual species biofilms compared to monospecies biofilms and using Caenorhabditis elegans infection assays, we demonstrated that more nematodes survived when co-infected with S. epidermidis ET-024 and S. aureus mutants lacking functional spa, splF or dps genes, compared to nematodes infected with S. epidermidis ET-024 and wild- type S. aureus. Finally, S. epidermidis ET-024 genes encoding resistance to oxacillin, erythromycin and tobramycin were upregulated in dual species biofilms and increased resistance was subsequently confirmed. Our data indicate that both species in dual species biofilms of S. epidermidis and S. aureus influence each other’s behavior, but additional studies are required necessary to elucidate the exact mechanism(s) involved.
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28
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Argemi X, Prévost G, Riegel P, Keller D, Meyer N, Baldeyrou M, Douiri N, Lefebvre N, Meghit K, Ronde Oustau C, Christmann D, Cianférani S, Strub JM, Hansmann Y. VISLISI trial, a prospective clinical study allowing identification of a new metalloprotease and putative virulence factor from Staphylococcus lugdunensis. Clin Microbiol Infect 2016; 23:334.e1-334.e8. [PMID: 28017792 DOI: 10.1016/j.cmi.2016.12.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 11/28/2016] [Accepted: 12/14/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Staphylococcus lugdunensis is a coagulase-negative staphylococcus that displays an unusually high virulence rate close to that of Staphylococcus aureus. It also shares phenotypic properties with S. aureus and several studies found putative virulence factors. The objective of the study was to describe the clinical manifestations of S. lugdunensis infections and investigate putative virulence factors. METHOD We conducted a prospective study from November 2013 to March 2016 at the University Hospital of Strasbourg. Putative virulence factors were investigated by clumping factor detection, screening for proteolytic activity, and sequence analysis using tandem nano-liquid chromatography-mass spectrometry. RESULTS In total, 347 positive samples for S. lugdunensis were collected, of which 129 (37.2%) were from confirmed cases of S. lugdunensis infection. Eighty-one of these 129 patients were included in the study. Bone and prosthetic joints (PJI) were the most frequent sites of infection (n=28; 34.6%) followed by skin and soft tissues (n=23; 28.4%). We identified and purified a novel protease secreted by 50 samples (61.7%), most frequently associated with samples from deep infections and PJI (pr 0.97 and pr 0.91, respectively). Protease peptide sequencing by nano-liquid chromatography-mass spectrometry revealed a novel protease bearing 62.42% identity with ShpI, a metalloprotease secreted by Staphylococcus hyicus. CONCLUSION This study confirms the pathogenicity of S. lugdunensis, particularly in bone and PJI. We also identified a novel metalloprotease called lugdulysin that may contribute to virulence.
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Affiliation(s)
- X Argemi
- Hôpitaux Universitaires, Maladies Infectieuses et Tropicales, Strasbourg, France; Université de Strasbourg, CHRU de Strasbourg, VBP EA7290, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Institut de Bactériologie, 3 Rue Koeberlé, Strasbourg, France.
| | - G Prévost
- Université de Strasbourg, CHRU de Strasbourg, VBP EA7290, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Institut de Bactériologie, 3 Rue Koeberlé, Strasbourg, France; Hôpitaux Universitaires, Laboratoire de Microbiologie, Strasbourg, France
| | - P Riegel
- Université de Strasbourg, CHRU de Strasbourg, VBP EA7290, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Institut de Bactériologie, 3 Rue Koeberlé, Strasbourg, France; Hôpitaux Universitaires, Laboratoire de Microbiologie, Strasbourg, France
| | - D Keller
- Hôpitaux Universitaires, Laboratoire de Microbiologie, Strasbourg, France
| | - N Meyer
- Hôpitaux Universitaires, Service de Santé Publique, Strasbourg, France
| | - M Baldeyrou
- Hôpitaux Universitaires, Maladies Infectieuses et Tropicales, Strasbourg, France
| | - N Douiri
- Hôpitaux Universitaires, Maladies Infectieuses et Tropicales, Strasbourg, France
| | - N Lefebvre
- Hôpitaux Universitaires, Maladies Infectieuses et Tropicales, Strasbourg, France
| | - K Meghit
- Hôpitaux Universitaires, Immunologie Clinique, Strasbourg, France
| | - C Ronde Oustau
- Hôpitaux Universitaires, Service de Chirurgie Orthopédique, CCOM, Strasbourg, France
| | - D Christmann
- Hôpitaux Universitaires, Maladies Infectieuses et Tropicales, Strasbourg, France; Université de Strasbourg, CHRU de Strasbourg, VBP EA7290, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Institut de Bactériologie, 3 Rue Koeberlé, Strasbourg, France
| | - S Cianférani
- Laboratoire de Spectrométrie de Masse Bio-Organique, Département des Sciences Analytiques, Institut Pluridisciplinaire Hubert Curien, UMR 7178 (CNRS-UdS), Strasbourg, France
| | - J M Strub
- Laboratoire de Spectrométrie de Masse Bio-Organique, Département des Sciences Analytiques, Institut Pluridisciplinaire Hubert Curien, UMR 7178 (CNRS-UdS), Strasbourg, France
| | - Y Hansmann
- Hôpitaux Universitaires, Maladies Infectieuses et Tropicales, Strasbourg, France; Université de Strasbourg, CHRU de Strasbourg, VBP EA7290, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Institut de Bactériologie, 3 Rue Koeberlé, Strasbourg, France
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Pathogenic features of clinically significant coagulase-negative staphylococci in hospital and community infections in Benin. Int J Med Microbiol 2016; 307:75-82. [PMID: 27876296 DOI: 10.1016/j.ijmm.2016.11.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 10/14/2016] [Accepted: 11/08/2016] [Indexed: 11/21/2022] Open
Abstract
In West Africa, very little consideration has been given to coagulase negative Staphylococci (CNS). Herein, we describe the features contributing to the pathogenicity of 99 clinically-significant independent CNS isolates associated with infections encountered at the National Teaching Hospital Center of Cotonou (Benin). The pathogenic potentials of nosocomial strains were compared with community strains. S. haemolyticus (44%), S. epidermidis (22%) and S. hominis (7%) were the most frequently isolated while bacteremia (66.7%) and urinary tract infections (24.2%) were the most commonly encountered infections. Most strains were resistant to multiple antibiotics, including penicillin (92%), fosfomycin (81%), methicillin (74%) and trimethoprim-sulfamethoxazole (72%). The most frequently isolated species were also the most frequently resistant to methicillin: S. hominis (100%), S. haemolyticus (93%) and S. epidermidis (67%). Screening of toxic functions or toxin presence revealed hemolytic potential in 25% of strains in over 50% of human erythrocytes in 1h. Twenty-six percent of strains exhibited protease activity with low (5%), moderate (10%) and high activity (11%), while 25% of strains displayed esterase activity. Three percent of strain supernatants were able to lyse 100% of human polymorphonuclear cells after 30min. Polymerase chain reaction and latex agglutination methods revealed staphylococcal enterotoxin C gene expression in 9% of S. epidermidis. A majority of hospital-associated CNS strains (68%) had at least one important virulence feature, compared with only 32% for community-acquired strains. The present investigation confirms that these microorganisms can be virulent, at least in some individual cases, possibly through genetic transfer from S. aureus.
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The Quorum Sensing Inhibitor Hamamelitannin Increases Antibiotic Susceptibility of Staphylococcus aureus Biofilms by Affecting Peptidoglycan Biosynthesis and eDNA Release. Sci Rep 2016; 6:20321. [PMID: 26828772 PMCID: PMC4734334 DOI: 10.1038/srep20321] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Accepted: 12/30/2015] [Indexed: 12/12/2022] Open
Abstract
Treatment of Staphylococcus aureus infections has become increasingly challenging due to the rapid emergence and dissemination of methicillin-resistant strains. In addition, S. aureus reside within biofilms at the site of infection. Few novel antibacterial agents have been developed in recent years and their bacteriostatic or bactericidal activity results in selective pressure, inevitably inducing antimicrobial resistance. Consequently, innovative antimicrobials with other modes of action are urgently needed. One alternative approach is targeting the bacterial quorum sensing (QS) system. Hamamelitannin (2′,5-di-O-galloyl-d-hamamelose; HAM) was previously suggested to block QS through the TraP QS system and was shown to increase S. aureus biofilm susceptibility towards vancomycin (VAN) although mechanistic insights are still lacking. In the present study we provide evidence that HAM specifically affects S. aureus biofilm susceptibility through the TraP receptor by affecting cell wall synthesis and extracellular DNA release of S. aureus. We further provide evidence that HAM can increase the susceptibility of S. aureus biofilms towards different classes of antibiotics in vitro. Finally, we show that HAM increases the susceptibility of S. aureus to antibiotic treatment in in vivo Caenorhabditis elegans and mouse mammary gland infection models.
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Marcinkiewicz J, Stręk P, Strus M, Głowacki R, Ciszek-Lenda M, Zagórska-Świeży K, Gawda A, Tomusiak A. Staphylococcus epidermidis and biofilm-associated neutrophils in chronic rhinosinusitis. A pilot study. Int J Exp Pathol 2016; 96:378-86. [PMID: 26765504 DOI: 10.1111/iep.12156] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 09/16/2015] [Indexed: 11/26/2022] Open
Abstract
A key role of bacterial biofilm in the pathogenesis of chronic rhinosinusitis (CRS) with (CRSwNP) and without nasal polyps (CRSsNP) is commonly accepted. However, the impact of some bacterial species isolated from inflamed sinus mucosa on biofilm formation is unclear. In particular, the role of Staphylococcus epidermidis as aetiological agents of CRS is controversial. Moreover, the effect of biofilm formation on neutrophil infiltration and activity in CRSwNP calls for explanation. In this study, biofilms were found in three of 10 patients (mean age = 46 ± 14) with CRS undergoing endoscopic sinus surgery by means of scanning electron microscopy. Unexpectedly, S. epidermidis was the primary isolated bacteria and was also found to be present in all biofilm-positive mucosa specimens, indicating its pivotal role in the pathogenesis of severe chronic infections associated with biofilm formation. We have also measured the activity of myeloperoxidase (MPO), the most abundant neutrophil enzyme, to demonstrate the presence of neutrophils in the samples tested. Our present results show that the level of MPO in CRS associated with biofilm is lower than that without biofilm. It may suggest either a low number of neutrophils or the presence of a type of neutrophils with compromised antimicrobial activity, described as biofilm-associated neutrophils (BAN). Finally, we conclude that further studies with a large number of CRS cases should be performed to establish the association between S. epidermidis and other frequently isolated bacterial species from paranasal sinuses, with the severity of CRS, biofilm formation and the infiltration of BAN.
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Affiliation(s)
| | - Paweł Stręk
- Department of Otorhinolaryngology, Jagiellonian University Medical College, Krakow, Poland
| | - Magdalena Strus
- Chair of Microbiology, Jagiellonian University Medical College, Krakow, Poland
| | - Roman Głowacki
- Department of Otorhinolaryngology, Jagiellonian University Medical College, Krakow, Poland
| | - Marta Ciszek-Lenda
- Chair of Immunology, Jagiellonian University Medical College, Krakow, Poland
| | | | - Anna Gawda
- Chair of Immunology, Jagiellonian University Medical College, Krakow, Poland
| | - Anna Tomusiak
- Chair of Microbiology, Jagiellonian University Medical College, Krakow, Poland
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Vandecandelaere I, Van Acker H, Coenye T. A Microplate-Based System as In Vitro Model of Biofilm Growth and Quantification. Methods Mol Biol 2016; 1333:53-66. [PMID: 26468099 DOI: 10.1007/978-1-4939-2854-5_5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We describe a 96-well microtiter plate-based system as an in vitro model for biofilm formation and quantification. Although in vitro assays are artificial systems and thus significantly differ from in vivo conditions, they represent an important tool to evaluate biofilm formation and the effect of compounds on biofilms. Stainings to evaluate the amount of biomass (crystal violet staining) and the number of metabolically active cells (resazurin assay) are discussed and specific attention is paid to the use of this model to quantify persisters in sessile populations.
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Affiliation(s)
- Ilse Vandecandelaere
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ottergemsesteenweg 460, Ghent, 9000, Belgium
| | - Heleen Van Acker
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ottergemsesteenweg 460, Ghent, 9000, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ottergemsesteenweg 460, Ghent, 9000, Belgium.
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Al-Hakami AM, Al-Amri A, Abdulrahim I, Hamid ME. Is there is an association between the presence of Staphylococcus species and occurrence of vernal keratoconjunctivitis? Saudi J Ophthalmol 2015; 29:255-8. [PMID: 26586974 PMCID: PMC4625191 DOI: 10.1016/j.sjopt.2015.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 04/17/2015] [Accepted: 05/07/2015] [Indexed: 01/08/2023] Open
Abstract
Purpose The aim of this study was to identify the association of normal bacterial flora with vernal keratoconjunctivitis (VKC) occurrence in VKC and non-VKC groups. Methods Conjunctival specimens were collected from 18 VKC patients and 22 healthy controls, cultured and identified following standard methods. The association between the presence of bacteria and occurrence of VKC was analyzed using Chi square statistic. Results Comparable bacterial growth was observed in VKC (77.8%) as well as control group (77.2%) (p = 0.970). Analysis of individual bacterial revealed that Staphylococcus aureus was detected more frequently in VKC (27.78% vs. 4.55% in control, p = 0.041) and Staphylococcus epidermidis was found much more commonly in the control eyes (45.45% in control vs. 5.56% in VKC, p = 0.005). Conclusions An aggravating role of S. aureus colonization in the occurrence of VKC, and a possible role of S. epidermidis against the occurrence of VKC were concluded.
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Affiliation(s)
- Ahmed M Al-Hakami
- Department of Microbiology and Clinical Parasitology, College of Medicine, King Khalid University, Saudi Arabia
| | - Abdulrahaman Al-Amri
- Department of Surgery, College of Medicine, King Khalid University, Saudi Arabia
| | - Ihab Abdulrahim
- Department of Microbiology and Clinical Parasitology, College of Medicine, King Khalid University, Saudi Arabia
| | - Mohamed E Hamid
- Department of Microbiology and Clinical Parasitology, College of Medicine, King Khalid University, Saudi Arabia
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Vandecandelaere I, Coenye T. Microbial composition and antibiotic resistance of biofilms recovered from endotracheal tubes of mechanically ventilated patients. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 830:137-55. [PMID: 25366226 DOI: 10.1007/978-3-319-11038-7_9] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In critically ill patients, breathing is impaired and mechanical ventilation, using an endotracheal tube (ET) connected to a ventilator, is necessary. Although mechanical ventilation is a life-saving procedure, it is not without risk. Because of several reasons, a biofilm often forms at the distal end of the ET and this biofilm is a persistent source of bacteria which can infect the lungs, causing ventilator-associated pneumonia (VAP). There is a link between the microbial flora of ET biofilms and the microorganisms involved in the onset of VAP. Culture dependent and independent techniques were already used to identify the microbial flora of ET biofilms and also, the antibiotic resistance of microorganisms obtained from ET biofilms was determined. The ESKAPE pathogens play a dominant role in the onset of VAP and these organisms were frequently identified in ET biofilms. Also, antibiotic resistant microorganisms were frequently present in ET biofilms. Members of the normal oral flora were also identified in ET biofilms but it is thought that these organisms initiate ET biofilm formation and are not directly involved in the development of VAP.
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Affiliation(s)
- Ilse Vandecandelaere
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ottergemsesteenweg 460, 9000, Ghent, Belgium
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Role for the A domain of unprocessed accumulation-associated protein (Aap) in the attachment phase of the Staphylococcus epidermidis biofilm phenotype. J Bacteriol 2014; 196:4268-75. [PMID: 25266380 DOI: 10.1128/jb.01946-14] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The polysaccharide intercellular adhesin or the cell wall-anchored accumulation-associated protein (Aap) mediates cellular accumulation during Staphylococcus epidermidis biofilm maturation. Mutation of sortase, which anchors up to 11 proteins (including Aap) to the cell wall, blocked biofilm development by the cerebrospinal fluid isolate CSF41498. Aap was implicated in this phenotype when Western blots and two-dimensional (2D) electrophoresis revealed increased levels of the protein in culture supernatants. Unexpectedly, reduced levels of primary attachment were associated with impaired biofilm formation by CSF41498 srtA and aap mutants. In contrast to previous studies, which implicated Aap proteolytic cleavage and, specifically, the Aap B domains in biofilm accumulation, the CSF41498 Aap protein was unprocessed. Furthermore, aap appeared to play a less important role in the biofilm phenotype of S. epidermidis 1457, in which the Aap protein is processed. Anti-Aap A-domain IgG inhibited primary attachment and biofilm formation in strain CSF41498 but not in strain 1457. The nucleotide sequences of the aap gene A-domain region and cleavage site in strains CSF41498 and 1457 were identical, implicating altered protease activity in the differential Aap processing results in the two strains. These data reveal a new role for the A domain of unprocessed Aap in the attachment phase of biofilm formation and suggest that extracellular protease activity can influence whether Aap contributes to the attachment or accumulation phases of the S. epidermidis biofilm phenotype.
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Loughran AJ, Atwood DN, Anthony AC, Harik NS, Spencer HJ, Beenken KE, Smeltzer MS. Impact of individual extracellular proteases on Staphylococcus aureus biofilm formation in diverse clinical isolates and their isogenic sarA mutants. Microbiologyopen 2014; 3:897-909. [PMID: 25257373 PMCID: PMC4263513 DOI: 10.1002/mbo3.214] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 08/07/2014] [Accepted: 08/15/2014] [Indexed: 01/01/2023] Open
Abstract
We demonstrate that the purified Staphylococcus aureus extracellular proteases aureolysin, ScpA, SspA, and SspB limit biofilm formation, with aureolysin having the greatest impact. Using protease-deficient derivatives of LAC, we confirmed that this is due to the individual proteases themselves. Purified aureolysin, and to a lesser extent ScpA and SspB, also promoted dispersal of an established biofilm. Mutation of the genes encoding these proteases also only partially restored biofilm formation in an FPR3757 sarA mutant and had little impact on restoring virulence in a murine bacteremia model. In contrast, eliminating the production of all of these proteases fully restored both biofilm formation and virulence in a sarA mutant generated in the closely related USA300 strain LAC. These results confirm an important role for multiple extracellular proteases in S. aureus pathogenesis and the importance of sarA in repressing their production. Moreover, purified aureolysin limited biofilm formation in 14 of 15 methicillin-resistant isolates and 11 of 15 methicillin-susceptible isolates, while dispersin B had little impact in UAMS-1, LAC, or 29 of 30 contemporary isolates of S. aureus. This suggests that the role of sarA and its impact on protease production is important in diverse strains of S. aureus irrespective of their methicillin resistance status.
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Affiliation(s)
- Allister J Loughran
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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