1
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Hauserman MR, Sullivan LE, James KL, Ferraro MJ, Rice KC. Response of Staphylococcus aureus physiology and Agr quorum sensing to low-shear modeled microgravity. J Bacteriol 2024; 206:e0027224. [PMID: 39120147 PMCID: PMC11411946 DOI: 10.1128/jb.00272-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Accepted: 07/11/2024] [Indexed: 08/10/2024] Open
Abstract
Staphylococcus aureus is commonly isolated from astronauts returning from spaceflight. Previous analysis of omics data from S. aureus low Earth orbit cultures indicated significantly increased expression of the Agr quorum sensing system and its downstream targets in spaceflight samples compared to ground controls. In this current study, the rotary cell culture system (RCCS) was used to investigate the effect of low-shear modeled microgravity (LSMMG) on S. aureus physiology and Agr activity. When cultured in the same growth medium and temperature as the previous spaceflight experiment, S. aureus LSMMG cultures exhibited decreased agr expression and altered growth compared to normal gravity control cultures, which are typically oriented with oxygenation membrane on the bottom of the high aspect rotating vessel (HARV). When S. aureus was grown in an inverted gravity control orientation (oxygenation membrane on top of the HARV), reduced Agr activity was observed relative to both traditional control and LSMMG cultures, signifying that oxygen availability may affect the observed differences in Agr activity. Metabolite assays revealed increased lactate and decreased acetate excretion in both LSMMG and inverted control cultures. Secretomics analysis of LSMMG, control, and inverted control HARV culture supernatants corroborated these results, with inverted and LSMMG cultures exhibiting a decreased abundance of Agr-regulated virulence factors and an increased abundance of proteins expressed in low-oxygen conditions. Collectively, these studies suggest that the orientation of the HARV oxygenation membrane can affect S. aureus physiology and Agr quorum sensing in the RCCS, a variable that should be considered when interpreting data using this ground-based microgravity model.IMPORTANCES. aureus is commonly isolated from astronauts returning from spaceflight and from surfaces within human-inhabited closed environments such as spacecraft. Astronaut health and immune function are significantly altered in spaceflight. Therefore, elucidating the effects of microgravity on S. aureus physiology is critical for assessing its pathogenic potential during long-term human space habitation. These results also highlight the necessity of eliminating potential confounding factors when comparing simulated microgravity model data with actual spaceflight experiments.
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Affiliation(s)
- Matthew R Hauserman
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, Florida, USA
| | - Leia E Sullivan
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, Florida, USA
| | - Kimberly L James
- Department of Biological Sciences, Florida Gulf Coast University, Fort Myers, Florida, USA
| | - Mariola J Ferraro
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, Florida, USA
| | - Kelly C Rice
- Department of Microbiology and Cell Science, IFAS, University of Florida, Gainesville, Florida, USA
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2
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Tajer L, Paillart JC, Dib H, Sabatier JM, Fajloun Z, Abi Khattar Z. Molecular Mechanisms of Bacterial Resistance to Antimicrobial Peptides in the Modern Era: An Updated Review. Microorganisms 2024; 12:1259. [PMID: 39065030 PMCID: PMC11279074 DOI: 10.3390/microorganisms12071259] [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: 05/08/2024] [Revised: 06/10/2024] [Accepted: 06/18/2024] [Indexed: 07/28/2024] Open
Abstract
Antimicrobial resistance (AMR) poses a serious global health concern, resulting in a significant number of deaths annually due to infections that are resistant to treatment. Amidst this crisis, antimicrobial peptides (AMPs) have emerged as promising alternatives to conventional antibiotics (ATBs). These cationic peptides, naturally produced by all kingdoms of life, play a crucial role in the innate immune system of multicellular organisms and in bacterial interspecies competition by exhibiting broad-spectrum activity against bacteria, fungi, viruses, and parasites. AMPs target bacterial pathogens through multiple mechanisms, most importantly by disrupting their membranes, leading to cell lysis. However, bacterial resistance to host AMPs has emerged due to a slow co-evolutionary process between microorganisms and their hosts. Alarmingly, the development of resistance to last-resort AMPs in the treatment of MDR infections, such as colistin, is attributed to the misuse of this peptide and the high rate of horizontal genetic transfer of the corresponding resistance genes. AMP-resistant bacteria employ diverse mechanisms, including but not limited to proteolytic degradation, extracellular trapping and inactivation, active efflux, as well as complex modifications in bacterial cell wall and membrane structures. This review comprehensively examines all constitutive and inducible molecular resistance mechanisms to AMPs supported by experimental evidence described to date in bacterial pathogens. We also explore the specificity of these mechanisms toward structurally diverse AMPs to broaden and enhance their potential in developing and applying them as therapeutics for MDR bacteria. Additionally, we provide insights into the significance of AMP resistance within the context of host-pathogen interactions.
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Affiliation(s)
- Layla Tajer
- Laboratory of Applied Biotechnology (LBA3B), Azm Center for Research in Biotechnology and Its Applications, Department of Cell Culture, EDST, Lebanese University, Tripoli 1300, Lebanon; (L.T.); (Z.F.)
| | - Jean-Christophe Paillart
- CNRS, Architecture et Réactivité de l’ARN, UPR 9002, Université de Strasbourg, 2 Allée Konrad Roentgen, F-67000 Strasbourg, France;
| | - Hanna Dib
- College of Engineering and Technology, American University of the Middle East, Egaila 54200, Kuwait;
| | - Jean-Marc Sabatier
- CNRS, INP, Inst Neurophysiopathol, Aix-Marseille Université, 13385 Marseille, France
| | - Ziad Fajloun
- Laboratory of Applied Biotechnology (LBA3B), Azm Center for Research in Biotechnology and Its Applications, Department of Cell Culture, EDST, Lebanese University, Tripoli 1300, Lebanon; (L.T.); (Z.F.)
- Department of Biology, Faculty of Sciences 3, Lebanese University, Campus Michel Slayman Ras Maska, Tripoli 1352, Lebanon
| | - Ziad Abi Khattar
- Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, P.O. Box 100, Tripoli, Lebanon
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3
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Costa FG, Mills KB, Crosby HA, Horswill AR. The Staphylococcus aureus regulatory program in a human skin-like environment. mBio 2024; 15:e0045324. [PMID: 38546267 PMCID: PMC11077960 DOI: 10.1128/mbio.00453-24] [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: 02/16/2024] [Accepted: 03/04/2024] [Indexed: 04/09/2024] Open
Abstract
Staphylococcus aureus is a Gram-positive pathogen responsible for the majority of skin and soft tissue infections (SSTIs). S. aureus colonizes the anterior nares of approximately 20%-30% of the population and transiently colonizes the skin, thereby increasing the risk of developing SSTIs and more serious infections. Current laboratory models that mimic the skin surface environment are expensive, require substantial infrastructure, and limit the scope of bacterial physiology studies under human skin conditions. To overcome these limitations, we developed a cost-effective, open-source, chemically defined media recipe termed skin-like medium (SLM) that incorporates key aspects of the human skin surface environment and supports growth of several staphylococcal species. We utilized SLM to investigate the transcriptional response of methicillin-resistant Staphylococcus aureus (MRSA) following growth in SLM compared to a commonly used laboratory media. Through RNA-seq analysis, we observed the upregulation of several virulence factors, including genes encoding functions involved in adhesion, proteolysis, and cytotoxicity. To further explore these findings, we conducted quantitative reverse transcription-PCR (qRT-PCR) experiments to determine the influence of media composition, pH, and temperature on the transcriptional response of key factors involved in adhesion and virulence. We also demonstrated that MRSA primed in SLM adhered better to human corneocytes and demonstrated adhesin-specific phenotypes that previously required genetic manipulation. This improved adherence to corneocytes was dependent on both acidic pH and growth in SLM. These results support the potential utility of SLM as an in vitro model for assessing staphylococcal physiology and metabolism on human skin. IMPORTANCE Staphylococcus aureus is the major cause of skin diseases, and its increased prevalence in skin colonization and infections present a need to understand its physiology in this environment. The work presented here outlines S. aureus upregulation of colonization and virulence factors using a newly developed medium that strives to replicate the human skin surface environment and demonstrates roles for adhesins clumping factor A (ClfA), serine-rich repeat glycoprotein adhesin (SraP), and the fibronectin binding proteins (Fnbps) in human corneocyte adherence.
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Affiliation(s)
- Flavia G. Costa
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Krista B. Mills
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Heidi A. Crosby
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Veterans Affairs, Eastern Colorado Healthcare System, Aurora, Colorado, USA
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4
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Gallo RL, Horswill AR. Staphylococcus aureus: The Bug Behind the Itch in Atopic Dermatitis. J Invest Dermatol 2024; 144:950-953. [PMID: 38430083 DOI: 10.1016/j.jid.2024.01.001] [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: 12/13/2023] [Revised: 12/29/2023] [Accepted: 01/02/2024] [Indexed: 03/03/2024]
Abstract
Pruritus or itch is a defining symptom of atopic dermatitis (AD). The origins of itch are complex, and it is considered both a defense mechanism and a cause of disease that leads to inflammation and psychological stress. Considerable progress has been made in understanding the processes that trigger itch, particularly the pruritoceptive origins that are generated in the skin. This perspective review discusses the implications of a recent observation that the V8 protease expressed by Staphylococcus aureus can directly trigger sensory neurons in the skin through activation of protease-activated receptor 1. This may be a key to understanding why itch is so common in AD because S. aureus commonly overgrows in this disease owing to deficient antimicrobial defense from both the epidermis and the cutaneous microbiome. Increased understanding of the role of microbes in AD provides increased opportunities for safely improving the treatment of this disorder.
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Affiliation(s)
- Richard L Gallo
- Department of Dermatology, University of California San Diego, La Jolla, California, USA.
| | - Alexander R Horswill
- Department of Immunology & Microbiology, School of Medicine, University of Colorado, Aurora, Colorado, USA
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5
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Lu L, Zhao Y, Li M, Wang X, Zhu J, Liao L, Wang J. Contemporary strategies and approaches for characterizing composition and enhancing biofilm penetration targeting bacterial extracellular polymeric substances. J Pharm Anal 2024; 14:100906. [PMID: 38634060 PMCID: PMC11022105 DOI: 10.1016/j.jpha.2023.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 11/08/2023] [Accepted: 11/26/2023] [Indexed: 04/19/2024] Open
Abstract
Extracellular polymeric substances (EPS) constitutes crucial elements within bacterial biofilms, facilitating accelerated antimicrobial resistance and conferring defense against the host's immune cells. Developing precise and effective antibiofilm approaches and strategies, tailored to the specific characteristics of EPS composition, can offer valuable insights for the creation of novel antimicrobial drugs. This, in turn, holds the potential to mitigate the alarming issue of bacterial drug resistance. Current analysis of EPS compositions relies heavily on colorimetric approaches with a significant bias, which is likely due to the selection of a standard compound and the cross-interference of various EPS compounds. Considering the pivotal role of EPS in biofilm functionality, it is imperative for EPS research to delve deeper into the analysis of intricate compositions, moving beyond the current focus on polymeric materials. This necessitates a shift from heavy reliance on colorimetric analytic methods to more comprehensive and nuanced analytical approaches. In this study, we have provided a comprehensive summary of existing analytical methods utilized in the characterization of EPS compositions. Additionally, novel strategies aimed at targeting EPS to enhance biofilm penetration were explored, with a specific focus on highlighting the limitations associated with colorimetric methods. Furthermore, we have outlined the challenges faced in identifying additional components of EPS and propose a prospective research plan to address these challenges. This review has the potential to guide future researchers in the search for novel compounds capable of suppressing EPS, thereby inhibiting biofilm formation. This insight opens up a new avenue for exploration within this research domain.
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Affiliation(s)
- Lan Lu
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, 610000, China
| | - Yuting Zhao
- Meishan Pharmaceutical Vocational College, School of Pharmacy, Meishan, Sichuan, 620200, China
| | - Mingxing Li
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Xiaobo Wang
- Hepatobiliary Surgery, Langzhong People's Hospital, Langzhong, Sichuan, 646000, China
| | - Jie Zhu
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, 610000, China
| | - Li Liao
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, 610000, China
| | - Jingya Wang
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu, 610000, China
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6
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Jurado A, Fernández L, Rodríguez A, García P. Prevalence of virulence- and antibiotic resistance-associated genotypes and phenotypes in Staphylococcus aureus strains from the food sector compared to clinical and cow mastitis isolates. Front Cell Infect Microbiol 2024; 14:1327131. [PMID: 38348375 PMCID: PMC10859521 DOI: 10.3389/fcimb.2024.1327131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 01/12/2024] [Indexed: 02/15/2024] Open
Abstract
Background Infections by the pathogen Staphylococcus aureus currently represent one of the most serious threats to human health worldwide, especially due to the production of enterotoxins and the ability to form biofilms. These structures and the acquisition of antibiotic resistance limit the action of antibiotics and disinfectants used to combat this microorganism in the industry and the clinic. Methods This work reports a comparative phenotypic and genotypic study of 18 S. aureus strains from different origins: clinical samples, milk from mastitic cows and food industry surfaces, most of which were isolated in Northern Spain. Results Genetically, the strains were very diverse but, in most cases, a closer proximity was observed for those from the same source. Notably, the average number of virulence genes was not significantly different in strains from the food sector. Of the 18 strains, 10 coded for at least one enterotoxin, and four of them carried 6 or 7 enterotoxin genes. The latter were all veterinary or clinical isolates. Most strains carried prophages, plasmids and/or pathogenicity islands. Regarding antibiotic resistance, although phenotypically all strains showed resistance to at least one antibiotic, resistance genes were only identified in 44.5% of strains, being mastitis isolates those with the lowest prevalence. Virulence-related phenotypic properties such as haemolytic activity, staphyloxanthin production, biofilm-forming capacity and spreading ability were widely distributed amongst the isolates. Conclusions Our results indicate that production of virulence factors, antibiotic resistance and biofilm formation can be found in S. aureus isolates from diverse environments, including the food industry, although some of these traits are more prevalent in strains isolated from infections in cows or humans. This emphasizes on the importance of monitoring the spread of these determinants not only in samples from the clinical environment, but also along the food chain, a strategy that falls under the prism of a one-health approach.
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Affiliation(s)
- Andrea Jurado
- Department of Technology and Biotechnology, Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Asturias, Spain
- DairySafe Group. Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Lucía Fernández
- Department of Technology and Biotechnology, Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Asturias, Spain
- DairySafe Group. Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Ana Rodríguez
- Department of Technology and Biotechnology, Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Asturias, Spain
- DairySafe Group. Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Pilar García
- Department of Technology and Biotechnology, Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Asturias, Spain
- DairySafe Group. Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
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7
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Costa FG, Mills KB, Crosby HA, Horswill AR. The Staphylococcus aureus regulatory program in a human skin-like environment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.24.563767. [PMID: 37961268 PMCID: PMC10634794 DOI: 10.1101/2023.10.24.563767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Staphylococcus aureus is a Gram-positive pathogen responsible for the majority of skin and soft tissue infections (SSTIs). S. aureus colonizes the anterior nares of approximately 20-30% of the population and transiently colonizes the skin, thereby increasing the risk of developing SSTIs and more serious infections. Current laboratory models that mimic the skin surface environment are expensive, require substantial infrastructure, and limit the scope of bacterial physiology studies under human skin conditions. To overcome these limitations, we developed a cost-effective, open-source, chemically defined media recipe termed skin-like media (SLM) that incorporates key aspects of the human skin surface environment and supports growth of several Staphylococcal species. We utilized SLM to investigate the transcriptional response of methicillin-resistant S. aureus (MRSA) following growth in SLM compared to a commonly used laboratory media. Through RNA-seq analysis, we observed the upregulation of several virulence factors, including genes encoding functions involved in adhesion, proteolysis, and cytotoxicity. To further explore these findings, we conducted qRT-PCR experiments to determine the influence of media composition, pH, and temperature on the transcriptional response of key factors involved in adhesion and virulence. We also demonstrated that MRSA primed in SLM adhered better to human corneocytes and demonstrated adhesin-specific phenotypes that previously required genetic manipulation. These results support the potential utility of SLM as an in vitro model for assessing Staphylococcal physiology and metabolism on human skin. Importance Staphylococcus aureus is the major cause of skin diseases, and its increased prevalence in skin colonization and infections present a need to understand its physiology in this environment. The work presented here outlines S. aureus upregulation of colonization and virulence factors using a newly developed media that strives to replicate the human skin surface environment, and demonstrates roles for adhesins ClfA, SraP, and Fnbps in human corneocyte adherence.
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8
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Francis D, Veeramanickathadathil Hari G, Koonthanmala Subash A, Bhairaddy A, Joy A. The biofilm proteome of Staphylococcus aureus and its implications for therapeutic interventions to biofilm-associated infections. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 138:327-400. [PMID: 38220430 DOI: 10.1016/bs.apcsb.2023.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
Staphylococcus aureus is a major healthcare concern due to its ability to inflict life-threatening infections and evolve antibiotic resistance at an alarming pace. It is frequently associated with hospital-acquired infections, especially device-associated infections. Systemic infections due to S. aureus are difficult to treat and are associated with significant mortality and morbidity. The situation is worsened by the ability of S. aureus to form social associations called biofilms. Biofilms embed a community of cells with the ability to communicate with each other and share resources within a polysaccharide or protein matrix. S. aureus establish biofilms on tissues and conditioned abiotic surfaces. Biofilms are hyper-tolerant to antibiotics and help evade host immune responses. Biofilms exacerbate the severity and recalcitrance of device-associated infections. The development of a biofilm involves various biomolecules, such as polysaccharides, proteins and nucleic acids, contributing to different structural and functional roles. Interconnected signaling pathways and regulatory molecules modulate the expression of these molecules. A comprehensive understanding of the molecular biology of biofilm development would help to devise effective anti-biofilm therapeutics. Although bactericidal agents, antimicrobial peptides, bacteriophages and nano-conjugated anti-biofilm agents have been employed with varying levels of success, there is still a requirement for effective and clinically viable anti-biofilm therapeutics. Proteins that are expressed and utilized during biofilm formation, constituting the biofilm proteome, are a particularly attractive target for anti-biofilm strategies. The proteome can be explored to identify potential anti-biofilm drug targets and utilized for rational drug discovery. With the aim of uncovering the biofilm proteome, this chapter explores the mechanism of biofilm formation and its regulation. Furthermore, it explores the antibiofilm therapeutics targeted against the biofilm proteome.
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Affiliation(s)
- Dileep Francis
- Department of Life Sciences, Kristu Jayanti College (Autonomous), Bengaluru, India.
| | | | | | - Anusha Bhairaddy
- Department of Life Sciences, Kristu Jayanti College (Autonomous), Bengaluru, India
| | - Atheene Joy
- Department of Life Sciences, Kristu Jayanti College (Autonomous), Bengaluru, India
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9
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Wang S, Zhao Y, Breslawec AP, Liang T, Deng Z, Kuperman LL, Yu Q. Strategy to combat biofilms: a focus on biofilm dispersal enzymes. NPJ Biofilms Microbiomes 2023; 9:63. [PMID: 37679355 PMCID: PMC10485009 DOI: 10.1038/s41522-023-00427-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 08/15/2023] [Indexed: 09/09/2023] Open
Abstract
Bacterial biofilms, which consist of three-dimensional extracellular polymeric substance (EPS), not only function as signaling networks, provide nutritional support, and facilitate surface adhesion, but also serve as a protective shield for the residing bacterial inhabitants against external stress, such as antibiotics, antimicrobials, and host immune responses. Biofilm-associated infections account for 65-80% of all human microbial infections that lead to serious mortality and morbidity. Tremendous effort has been spent to address the problem by developing biofilm-dispersing agents to discharge colonized microbial cells to a more vulnerable planktonic state. Here, we discuss the recent progress of enzymatic eradicating strategies against medical biofilms, with a focus on dispersal mechanisms. Particularly, we review three enzyme classes that have been extensively investigated, namely glycoside hydrolases, proteases, and deoxyribonucleases.
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Affiliation(s)
- Shaochi Wang
- Otorhinolaryngology Hospital, The First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China
- Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China
| | - Yanteng Zhao
- Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China
| | - Alexandra P Breslawec
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20740, USA
| | - Tingting Liang
- Key Laboratory of Natural Medicine and Immune-Engineering of Henan Province, Henan University Jinming Campus, 475004, Kaifeng, Henan, China
| | - Zhifen Deng
- Translational Medicine Center, The First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China
| | - Laura L Kuperman
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20740, USA.
- Mirimus Inc., 760 Parkside Avenue, Brooklyn, NY, 11226, USA.
| | - Qiuning Yu
- Otorhinolaryngology Hospital, The First Affiliated Hospital of Zhengzhou University, 450052, Zhengzhou, China.
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10
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Torres NJ, Rizzo DN, Reinberg MA, Jobson ME, Totzke BC, Jackson JK, Yu W, Shaw LN. The identification of two M20B family peptidases required for full virulence in Staphylococcus aureus. Front Cell Infect Microbiol 2023; 13:1176769. [PMID: 37538308 PMCID: PMC10394242 DOI: 10.3389/fcimb.2023.1176769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 06/13/2023] [Indexed: 08/05/2023] Open
Abstract
We have previously demonstrated that deletion of an intracellular leucine aminopeptidase results in attenuated virulence of S. aureus. Herein we explore the role of 10 other aminopeptidases in S. aureus pathogenesis. Using a human blood survival assay we identified mutations in two enzymes from the M20B family (PepT1 and PepT2) as having markedly decreased survival compared to the parent. We further reveal that pepT1, pepT2 and pepT1/2 mutant strains are impaired in their ability to resist phagocytosis by, and engender survival within, human macrophages. Using a co-infection model of murine sepsis, we demonstrate impairment of dissemination and survival for both single mutants that is even more pronounced in the double mutant. We show that these enzymes are localized to the cytosol and membrane but are not necessary for peptide-based nutrition, a hallmark of cell-associated aminopeptidases. Furthermore, none of the survival defects appear to be the result of altered virulence factor production. An exploration of their regulation reveals that both are controlled by known regulators of the S. aureus virulence process, including Agr, Rot and/or SarA, and that this cascade may be mediated by FarR. Structural modeling of PepT1 reveals it bears all the hallmarks of a tripeptidase, whilst PepT2 differs significantly in its catalytic pocket, suggesting a broader substrate preference. In sum, we have identified two M20B aminopeptidases that are integral to S. aureus pathogenesis. The future identification of protein and/or peptide targets for these proteases will be critical to understanding their important virulence impacting functions.
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Affiliation(s)
| | | | | | | | | | | | | | - Lindsey N. Shaw
- Department of Molecular Biosciences, University of South Florida, Tampa, FL, United States
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11
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Zhou C, Li X, Tang SW, Liu C, Lam MHW, Lam YW. A Dual-Enzyme Amplification Loop for the Sensitive Biosensing of Endopeptidases. ACS OMEGA 2023; 8:25592-25600. [PMID: 37483190 PMCID: PMC10357553 DOI: 10.1021/acsomega.3c03533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 06/23/2023] [Indexed: 07/25/2023]
Abstract
A rapid and sensitive approach for the detection of endopeptidases via a new analyte-triggered mutual emancipation of linker-immobilized enzymes (AMELIE) mechanism has been developed and demonstrated using a matrix metallopeptidase, a collagenase, as the model endopeptidase analyte. AMELIE involves an autocatalytic loop created by a pair of selected enzymes immobilized on solid substrates via linkers with specific sites that can be proteolyzed by one another. These bound enzymes are spatially separated so that they cannot act upon their corresponding substrates until the introduction of the target endopeptidase analyte that can also cleave one of the linkers. This triggers the self-sustained loop of enzymatic activities to emancipate all the immobilized enzymes. In this proof of concept, signal transduction was achieved by a colorimetric horseradish peroxidase-tetramethylbenzidine (HRP-TMB-H2O2) reaction with HRP that are also being immobilized by one of the linkers. The pair of immobilized enzymes were collagenase and alginate lyase, and they were immobilized by an alginate linker and a short peptide chain containing the amino acid sequence of Leu-Gly-Pro-Ala for collagenase. A detection limit of 2.5 pg collagenase mL-1 with a wide linear range up to 4 orders of magnitude was achieved. The AMELIE biosensor can detect extracellular collagenase in the supernatant of various bacteria cultures, with a sensitivity as low as 103 cfu mL-1 of E. coli. AMELIE can readily be adapted to provide the sensitive detection of other endopeptidases.
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Affiliation(s)
- Chuanwen Zhou
- Department
of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Xiaomin Li
- Department
of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Sze Wing Tang
- Department
of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Chunxi Liu
- Department
of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Michael H. W. Lam
- Department
of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Yun Wah Lam
- Department
of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
- School
of Applied Sciences, University of Huddersfield, Huddersfield HD1 3DH, U.K.
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12
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Hsieh RC, Liu R, Burgin DJ, Otto M. Understanding mechanisms of virulence in MRSA: implications for antivirulence treatment strategies. Expert Rev Anti Infect Ther 2023; 21:911-928. [PMID: 37501364 DOI: 10.1080/14787210.2023.2242585] [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: 05/15/2023] [Accepted: 07/26/2023] [Indexed: 07/29/2023]
Abstract
INTRODUCTION Methicillin-resistant Staphylococcus aureus (MRSA) is a widespread pathogen, often causing recurrent and deadly infections in the hospital and community. Many S. aureus virulence factors have been suggested as potential targets for antivirulence therapy to decrease the threat of diminishing antibiotic availability. Antivirulence methods hold promise due to their adjunctive and prophylactic potential and decreased risk for selective pressure. AREAS COVERED This review describes the dominant virulence mechanisms exerted by MRSA and antivirulence therapeutics that are currently undergoing testing in clinical or preclinical stages. We also discuss the advantages and downsides of several investigational antivirulence approaches, including the targeting of bacterial transporters, host-directed therapy, and quorum-sensing inhibitors. For this review, a systematic search of literature on PubMed, Google Scholar, and Web of Science for relevant search terms was performed in April and May 2023. EXPERT OPINION Vaccine and antibody strategies have failed in clinical trials and could benefit from more basic science-informed approaches. Antivirulence-targeting approaches need to be set up better to meet the requirements of drug development, rather than only providing limited results to provide 'proof-of-principle' translational value of pathogenesis research. Nevertheless, there is great potential of such strategies and potential particular promise for novel probiotic approaches.
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Affiliation(s)
- Roger C Hsieh
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Ryan Liu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Dylan J Burgin
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
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Chen Y, Knight R, Gallo RL. Evolving approaches to profiling the microbiome in skin disease. Front Immunol 2023; 14:1151527. [PMID: 37081873 PMCID: PMC10110978 DOI: 10.3389/fimmu.2023.1151527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 03/14/2023] [Indexed: 04/22/2023] Open
Abstract
Despite its harsh and dry environment, human skin is home to diverse microbes, including bacteria, fungi, viruses, and microscopic mites. These microbes form communities that may exist at the skin surface, deeper skin layers, and within microhabitats such as the hair follicle and sweat glands, allowing complex interactions with the host immune system. Imbalances in the skin microbiome, known as dysbiosis, have been linked to various inflammatory skin disorders, including atopic dermatitis, acne, and psoriasis. The roles of abundant commensal bacteria belonging to Staphylococcus and Cutibacterium taxa and the fungi Malassezia, where particular species or strains can benefit the host or cause disease, are increasingly appreciated in skin disorders. Furthermore, recent research suggests that the interactions between microorganisms and the host's immune system on the skin can have distant and systemic effects on the body, such as on the gut and brain, known as the "skin-gut" or "skin-brain" axes. Studies on the microbiome in skin disease have typically relied on 16S rRNA gene sequencing methods, which cannot provide accurate information about species or strains of microorganisms on the skin. However, advancing technologies, including metagenomics and other functional 'omic' approaches, have great potential to provide more comprehensive and detailed information about the skin microbiome in health and disease. Additionally, inter-species and multi-kingdom interactions can cause cascading shifts towards dysbiosis and are crucial but yet-to-be-explored aspects of many skin disorders. Better understanding these complex dynamics will require meta-omic studies complemented with experiments and clinical trials to confirm function. Evolving how we profile the skin microbiome alongside technological advances is essential to exploring such relationships. This review presents the current and emerging methods and their findings for profiling skin microbes to advance our understanding of the microbiome in skin disease.
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Affiliation(s)
- Yang Chen
- Department of Dermatology, University of California San Diego, La Jolla, CA, United States
- Department of Pediatrics, University of California San Diego, La Jolla, CA, United States
- Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA, United States
| | - Rob Knight
- Department of Pediatrics, University of California San Diego, La Jolla, CA, United States
- Department of Computer Science and Engineering, University of California San Diego, La Jolla, CA, United States
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
- Center for Microbiome Innovation, University of California San Diego, La Jolla, CA, United States
| | - Richard L. Gallo
- Department of Dermatology, University of California San Diego, La Jolla, CA, United States
- Center for Microbiome Innovation, University of California San Diego, La Jolla, CA, United States
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Merghni A, Hamdi H, Ben Abdallah M, Al-Hasawi ZM, Al-Quwaie DA, Abid-Essefi S. Detection of Methicillin-Resistant Staphylococcus aureus among Foodborne Pathogenic Strains and Assessment of Their Adhesion Ability and Cytotoxic Effects in HCT-116 Cells. Foods 2023; 12:foods12050974. [PMID: 36900491 PMCID: PMC10001405 DOI: 10.3390/foods12050974] [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: 01/25/2023] [Revised: 02/14/2023] [Accepted: 02/21/2023] [Indexed: 03/02/2023] Open
Abstract
Staphylococcus aureus is one of the high-threat pathogens equipped with a repertoire of virulence factors making it responsible for many infections in humans, including foodborne diseases. The present study aims to characterize antibiotic resistance and virulence factors in foodborne S. aureus isolates, and to investigate their cytotoxic effects in human intestinal cells (HCT-116). Our results revealed methicillin resistance phenotypes (MRSA) along with the detection of mecA gene (20%) among tested foodborne S. aureus strains. Furthermore, 40% of tested isolates showed a strong ability for adhesion and biofilm formation. A high rate of exoenzymes production by tested bacteria was also registered. Additionally, treatment with S. aureus extracts leads to a significant decrease in HCT-116 cell viability, accompanied by a reduction in the mitochondrial membrane potential (MMP), as a result of reactive oxygen species (ROS) generation. Thereby, S. aureus food poisoning remains daunting and needs particular concern to prevent foodborne illness.
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Affiliation(s)
- Abderrahmen Merghni
- Laboratory of Antimicrobial Resistance LR99ES09, Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis 1007, Tunisia
- Correspondence:
| | - Hiba Hamdi
- Laboratory for Research on Biologically Compatible Compounds, LR01SE17, Faculty of Dental Medicine, University of Monastir, Monastir 5000, Tunisia
| | - Marwa Ben Abdallah
- Laboratory of Transmissible Diseases and Biologically Active Substances, Faculty of Pharmacy, University of Monastir, Monastir 5000, Tunisia
| | - Zaki M. Al-Hasawi
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Biological Sciences Department, College of Science & Arts, King Abdulaziz University, Rabigh 21911, Saudi Arabia
| | - Diana A. Al-Quwaie
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Salwa Abid-Essefi
- Laboratory for Research on Biologically Compatible Compounds, LR01SE17, Faculty of Dental Medicine, University of Monastir, Monastir 5000, Tunisia
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Francis D, Bhairaddy A, Joy A, Hari GV, Francis A. Secretory proteins in the orchestration of microbial virulence: The curious case of Staphylococcus aureus. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 133:271-350. [PMID: 36707204 DOI: 10.1016/bs.apcsb.2022.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Microbial virulence showcases an excellent model for adaptive changes that enable an organism to survive and proliferate in a hostile environment and exploit host resources to its own benefit. In Staphylococcus aureus, an opportunistic pathogen of the human host, known for the diversity of the disease conditions it inflicts and the rapid evolution of antibiotic resistance, virulence is a consequence of having a highly plastic genome that is amenable to quick reprogramming and the ability to express a diverse arsenal of virulence factors. Virulence factors that are secreted to the host milieu effectively manipulate the host conditions to favor bacterial survival and growth. They assist in colonization, nutrient acquisition, immune evasion, and systemic spread. The structural and functional characteristics of the secreted virulence proteins have been shaped to assist S. aureus in thriving and disseminating effectively within the host environment and exploiting the host resources to its best benefit. With the aim of highlighting the importance of secreted virulence proteins in bacterial virulence, the present chapter provides a comprehensive account of the role of the major secreted proteins of S. aureus in orchestrating its virulence in the human host.
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Affiliation(s)
- Dileep Francis
- Department of Life Sciences, Kristu Jayanti College, Autonomous, Bengaluru, Karnataka, India.
| | - Anusha Bhairaddy
- Department of Life Sciences, Kristu Jayanti College, Autonomous, Bengaluru, Karnataka, India
| | - Atheene Joy
- Department of Life Sciences, Kristu Jayanti College, Autonomous, Bengaluru, Karnataka, India
| | | | - Ashik Francis
- Rajiv Gandhi Centre for Biotechnology, Trivandrum, Kerala, India
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In Silico Genome-Scale Analysis of Molecular Mechanisms Contributing to the Development of a Persistent Infection with Methicillin-Resistant Staphylococcus aureus (MRSA) ST239. Int J Mol Sci 2022; 23:ijms232416086. [PMID: 36555727 PMCID: PMC9781258 DOI: 10.3390/ijms232416086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/05/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
The increasing frequency of isolation of methicillin-resistant Staphylococcus aureus (MRSA) limits the chances for the effective antibacterial therapy of staphylococcal diseases and results in the development of persistent infection such as bacteremia and osteomyelitis. The aim of this study was to identify features of the MRSAST239 0943-1505-2016 (SA943) genome that contribute to the formation of both acute and chronic musculoskeletal infections. The analysis was performed using comparative genomics data of the dominant epidemic S. aureus lineages, namely ST1, ST8, ST30, ST36, and ST239. The SA943 genome encodes proteins that provide resistance to the host's immune system, suppress immunological memory, and form biofilms. The molecular mechanisms of adaptation responsible for the development of persistent infection were as follows: amino acid substitution in PBP2 and PBP2a, providing resistance to ceftaroline; loss of a large part of prophage DNA and restoration of the nucleotide sequence of beta-hemolysin, that greatly facilitates the escape of phagocytosed bacteria from the phagosome and formation of biofilms; dysfunction of the AgrA system due to the presence of psm-mec and several amino acid substitutions in the AgrC; partial deletion of the nucleotide sequence in genomic island vSAβ resulting in the loss of two proteases of Spl-operon; and deletion of SD repeats in the SdrE amino acid sequence.
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Study of SarA by DNA Affinity Capture Assay (DACA) Employing Three Promoters of Key Virulence and Resistance Genes in Methicillin-Resistant Staphylococcus aureus. Antibiotics (Basel) 2022; 11:antibiotics11121714. [PMID: 36551372 PMCID: PMC9774152 DOI: 10.3390/antibiotics11121714] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/21/2022] [Accepted: 11/25/2022] [Indexed: 11/29/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA), one of the most well-known human pathogens, houses many virulence factors and regulatory proteins that confer resistance to diverse antibiotics. Although they have been investigated intensively, the correlations among virulence factors, regulatory proteins and antibiotic resistance are still elusive. We aimed to identify the most significant global MRSA regulator by concurrently analyzing protein-binding and several promoters under same conditions and at the same time point. DNA affinity capture assay (DACA) was performed with the promoters of mecA, sarA, and sarR, all of which significantly impact survival of MRSA. Here, we show that SarA protein binds to all three promoters. Consistent with the previous reports, ΔsarA mutant exhibited weakened antibiotic resistance to oxacillin and reduced biofilm formation. Additionally, production and activity of many virulence factors such as phenol-soluble modulins (PSM), α-hemolysin, motility, staphyloxanthin, and other related proteins were decreased. Comparing the sequence of SarA with that of clinical strains of various lineages showed that all sequences were highly conserved, in contrast to that observed for AgrA, another major regulator of virulence and resistance in MRSA. We have demonstrated that SarA regulates antibiotic resistance and the expression of various virulence factors. Our results warrant that SarA could be a leading target for developing therapeutic agents against MRSA infections.
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Saleh MM, Yousef N, Shafik SM, Abbas HA. Attenuating the virulence of the resistant superbug Staphylococcus aureus bacteria isolated from neonatal sepsis by ascorbic acid, dexamethasone, and sodium bicarbonate. BMC Microbiol 2022; 22:268. [PMID: 36348266 PMCID: PMC9644464 DOI: 10.1186/s12866-022-02684-x] [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: 07/14/2022] [Accepted: 10/29/2022] [Indexed: 11/11/2022] Open
Abstract
Background Infections affecting neonates caused by Staphylococcus aureus are widespread in healthcare facilities; hence, novel strategies are needed to fight this pathogen. In this study, we aimed to investigate the effectiveness of the FDA-approved medications ascorbic acid, dexamethasone, and sodium bicarbonate to reduce the virulence of the resistant Staphylococcus aureus bacteria that causes neonatal sepsis and seek out suitable alternatives to the problem of multi-drug resistance. Methods Tested drugs were assessed phenotypically and genotypically for their effects on virulence factors and virulence-encoding genes in Staphylococcus aureus. Furthermore, drugs were tested in vivo for their ability to reduce Staphylococcus aureus pathogenesis. Results Sub-inhibitory concentrations (1/8 MIC) of ascorbic acid, dexamethasone, and sodium bicarbonate reduced the production of Staphylococcus aureus virulence factors, including biofilm formation, staphyloxanthin, proteases, and hemolysin production, as well as resistance to oxidative stress. At the molecular level, qRT-PCR was used to assess the relative expression levels of crtM, sigB, sarA, agrA, hla, fnbA, and icaA genes regulating virulence factors production and showed a significant reduction in the relative expression levels of all the tested genes. Conclusions The current findings reveal that ascorbic acid, dexamethasone, and sodium bicarbonate have strong anti-virulence effects against Staphylococcus aureus. Thus, suggesting that they might be used as adjuvants to treat infections caused by Staphylococcus aureus in combination with conventional antimicrobials or as alternative therapies.
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Fernandes A, Ramos C, Monteiro V, Santos J, Fernandes P. Virulence Potential and Antibiotic Susceptibility of S. aureus Strains Isolated from Food Handlers. Microorganisms 2022; 10:2155. [PMID: 36363746 PMCID: PMC9696720 DOI: 10.3390/microorganisms10112155] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 10/25/2022] [Accepted: 10/27/2022] [Indexed: 08/27/2023] Open
Abstract
Staphylococcus spp. are common members of the normal human flora. However, some Staphylococcus species are recognised as human pathogens due to the production of several virulence factors and enterotoxins that are particularly worrisome in food poisoning. Since many of Staphylococcal food poisoning outbreaks are typically associated with cross-contamination, the detection of S. aureus on food handlers was performed. Hand swabs from 167 food handlers were analysed for the presence of S. aureus. More than 11% of the samples were positive for S. aureus. All S. aureus strains were isolated and analysed for the presence of virulence and enterotoxin genes, namely, sea, seb, sec, sed, seg, sei, tsst-1 and pvl. The same strains were phenotypically characterised in terms of antibiotic susceptibility using the disc diffusion method and antimicrobial agents from 12 different classes. A low prevalence of antibiotic-resistant strains was found, with 55.6% of the strains being sensitive to all of the antimicrobial agents tested. However, a high prevalence of resistance to macrolides was found, with 44.4% of the strains showing resistance to erythromycin. At least one of the virulence or toxin genes was detected in 61.1% of the strains, and seg was the most prevalent toxin gene, being detected in 44.4% of the strains.
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Affiliation(s)
- Adriana Fernandes
- Escola Superior de Tecnologia e Gestão, Instituto Politécnico de Viana do Castelo, Rua Escola Industrial e Comercial de Nun’Álvares, 4900-347 Viana do Castelo, Portugal
| | - Carla Ramos
- Escola Superior de Tecnologia e Gestão, Instituto Politécnico de Viana do Castelo, Rua Escola Industrial e Comercial de Nun’Álvares, 4900-347 Viana do Castelo, Portugal
| | - Victor Monteiro
- Escola Superior de Tecnologia e Gestão, Instituto Politécnico de Viana do Castelo, Rua Escola Industrial e Comercial de Nun’Álvares, 4900-347 Viana do Castelo, Portugal
| | - Joana Santos
- Escola Superior de Tecnologia e Gestão, Instituto Politécnico de Viana do Castelo, Rua Escola Industrial e Comercial de Nun’Álvares, 4900-347 Viana do Castelo, Portugal
- CISAS, Escola Superior de Tecnologia e Gestão, Instituto Politécnico de Viana do Castelo, Rua Escola Industrial e Comercial de Nun’Álvares, 4900-347 Viana do Castelo, Portugal
| | - Paulo Fernandes
- Escola Superior de Tecnologia e Gestão, Instituto Politécnico de Viana do Castelo, Rua Escola Industrial e Comercial de Nun’Álvares, 4900-347 Viana do Castelo, Portugal
- CISAS, Escola Superior de Tecnologia e Gestão, Instituto Politécnico de Viana do Castelo, Rua Escola Industrial e Comercial de Nun’Álvares, 4900-347 Viana do Castelo, Portugal
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20
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Activation of Human Platelets by Staphylococcus aureus Secreted Protease Staphopain A. Pathogens 2022; 11:pathogens11111237. [DOI: 10.3390/pathogens11111237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 10/19/2022] [Accepted: 10/24/2022] [Indexed: 11/17/2022] Open
Abstract
Infection by Staphylococcus aureus is the leading cause of infective endocarditis (IE). Activation of platelets by this pathogen results in their aggregation and thrombus formation which are considered to be important steps in the development and pathogenesis of IE. Here, we show that a secreted cysteine protease, staphopain A, activates human platelets and induces their aggregation. The culture supernatant of a scpA mutant deficient in staphopain A production was reduced in its ability to trigger platelet aggregation. The platelet agonist activity of purified staphopain A was inhibited by staphostatin A, a specific inhibitor, thus implicating its protease activity in the agonism. In whole blood, using concentrations of staphopain A that were otherwise insufficient to induce platelet aggregation, increased binding to collagen and thrombus formation was observed. Using antagonists specific to protease-activated receptors 1 and 4, we demonstrate their role in mediating staphopain A induced platelet activation.
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The Small RNA Teg41 Is a Pleiotropic Regulator of Virulence in Staphylococcus aureus. Infect Immun 2022; 90:e0023622. [PMID: 36214557 PMCID: PMC9670889 DOI: 10.1128/iai.00236-22] [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: 11/20/2022] Open
Abstract
Previously, our group demonstrated a role for the small RNA (sRNA) Teg41 in regulating production of the alpha phenol-soluble modulin toxins (αPSMs) in Staphylococcus aureus. Overexpressing Teg41 increased αPSM production while deleting the 3' end of Teg41 (Teg41Δ3' strain) resulted in a decrease in αPSM production, reduced hemolytic activity of S. aureus culture supernatants, and attenuated virulence in a murine abscess model of infection. In this study, we further explore the attenuation of virulence in the Teg41Δ3' strain. Using both localized and systemic models of infection, we demonstrate that the Teg41Δ3' strain is more severely attenuated than an ΔαPSM mutant, strongly suggesting that Teg41 influences more than the αPSMs. Proteomic and transcriptomic analysis of the wild-type and Teg41Δ3' strains reveals widespread alterations in transcript abundance and protein production in the absence of Teg41, confirming that Teg41 has pleiotropic effects in the cell. We go on to investigate the molecular mechanism underlying Teg41-mediated gene regulation. Surprisingly, results demonstrate that certain Teg41 target genes, including the αPSMs and βPSMs, are transcriptionally altered in the Teg41Δ3' strain, while other targets, specifically spa (encoding surface protein A), are regulated at the level of transcript stability. Collectively, these data demonstrate that Teg41 is a pleiotropic RNA regulator in S. aureus that influences expression of a variety of genes using multiple different mechanisms.
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22
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Ongpipattanakul C, Desormeaux EK, DiCaprio A, van der Donk WA, Mitchell DA, Nair SK. Mechanism of Action of Ribosomally Synthesized and Post-Translationally Modified Peptides. Chem Rev 2022; 122:14722-14814. [PMID: 36049139 PMCID: PMC9897510 DOI: 10.1021/acs.chemrev.2c00210] [Citation(s) in RCA: 66] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a natural product class that has undergone significant expansion due to the rapid growth in genome sequencing data and recognition that they are made by biosynthetic pathways that share many characteristic features. Their mode of actions cover a wide range of biological processes and include binding to membranes, receptors, enzymes, lipids, RNA, and metals as well as use as cofactors and signaling molecules. This review covers the currently known modes of action (MOA) of RiPPs. In turn, the mechanisms by which these molecules interact with their natural targets provide a rich set of molecular paradigms that can be used for the design or evolution of new or improved activities given the relative ease of engineering RiPPs. In this review, coverage is limited to RiPPs originating from bacteria.
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Affiliation(s)
- Chayanid Ongpipattanakul
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Emily K. Desormeaux
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Adam DiCaprio
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Wilfred A. van der Donk
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
- Department of Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
- Departments of Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, USA
| | - Douglas A. Mitchell
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
- Department of Microbiology, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
- Departments of Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, USA
| | - Satish K. Nair
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
- Departments of Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, USA
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Cetik Yildiz S. Staphylococcus aureus and Methicillin Resistant Staphylococcus aureus (MRSA) Carriage and Infections. Infect Dis (Lond) 2022. [DOI: 10.5772/intechopen.107138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Staphylococcus aureus is among the most common opportunistic infections worldwide, as it is found as part of the flora in many parts of the body. S. aureus is the leading cause of nosocomial infections with its ability to rapidly colonize the infected area, high virulence, rapid adaptation to environmental conditions, and the ability to develop very fast and effective resistance even to new generation antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA), first identified in the 1960s, is one of the most successful modern pathogens, becoming an important factor in hospitals in the 1980s. MRSA is an important factor, especially in hospitalized patients and healthcare-associated infections. Patients colonized with S. aureus and MRSA are at risk for community-acquired infections. It is critical that multidrug resistance reduces treatment options in MRSA infections and MRSA strains. These microorganisms have been the subject of research for years as they spread and become resistant in both social and medical settings and cause great morbidity and mortality. With the rapid spread of resistance among bacteria, antibiotic resistance has increased the cost of health care, and this has become the factor limiting the production of new antibiotics.
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Affiliation(s)
- Phuong Pham
- Centre for Advanced Macromolecular Design and Australian Centre for NanoMedicine School of Chemical Engineering The University of New South Wales Sydney NSW 2052 Australia
| | - Susan Oliver
- Centre for Advanced Macromolecular Design and Australian Centre for NanoMedicine School of Chemical Engineering The University of New South Wales Sydney NSW 2052 Australia
| | - Cyrille Boyer
- Centre for Advanced Macromolecular Design and Australian Centre for NanoMedicine School of Chemical Engineering The University of New South Wales Sydney NSW 2052 Australia
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Mechanisms Behind the Indirect Impact of Metabolic Regulators on Virulence Factor Production in Staphylococcus aureus. Microbiol Spectr 2022; 10:e0206322. [PMID: 35862951 PMCID: PMC9430575 DOI: 10.1128/spectrum.02063-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Staphylococcus aureus is a human skin pathogen capable of causing invasive infections in many tissues in the human body. The host of virulence factors, such as toxins and proteases, available to S. aureus contribute to its diverse disease presentations. The majority of these virulence factors are under the control of the Agr quorum sensing system. The interaction between the Agr system and some well-established metabolic regulators has long been noted, but no mechanism has been provided as to these indirect interactions. In this study, we examine the connection between Agr and CcpA, a regulator of central carbon metabolism with a known positive impact on Agr function. We further investigated the interaction of Agr and CodY, a regulator of amino acid metabolism and a member of the stringent response with a known negative impact on Agr function. We show that though there are alterations in intracellular amino acid levels in each of these mutants that are consistent with their effect on Agr, there does not seem to be a direct impact on the translation of the Agr system itself that contributes to the altered expression observed in these mutants. Given the changes in cellular metabolism in a ΔccpA mutant, we find reduced levels of intracellular ATP even in the presence of glucose. This reduction in ATP, combined with the reduced affinity of the AgrC sensor kinase for ATP, explains the reduction in Agr activity long observed in ΔccpA strains. IMPORTANCE The human pathogen Staphylococcus aureus produces a great number of virulence factors that contribute to the pathogen’s ability to cause dangerous, invasive infections. Understanding the full scope of the regulation of these virulence factors can provide us with new information about how to target virulence factor production. For years, researchers in the field have observed an impact of metabolic regulators on virulence factor production with no mechanistic explanation. Here, we describe the role of two of these regulators, CcpA and CodY, in virulence factor expression and provide evidence of indirect mechanisms contributing to the control of the Agr system and virulence factor production by these two metabolic regulators. Our study sheds light on the interplay between metabolism and virulence in S. aureus and provides an explanation as to how these concepts are linked.
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Deepika G, Subbarayadu S, Chaudhary A, Sarma PVGK. Dibenzyl (benzo [d] thiazol-2-yl (hydroxy) methyl) phosphonate (DBTMP) showing anti-S. aureus and anti-biofilm properties by elevating activities of serine protease (SspA) and cysteine protease staphopain B (SspB). Arch Microbiol 2022; 204:397. [PMID: 35708833 DOI: 10.1007/s00203-022-02974-y] [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: 11/16/2021] [Revised: 04/26/2022] [Accepted: 05/11/2022] [Indexed: 11/02/2022]
Abstract
Staphylococcus aureus biofilms are the pathogenic factor in the spread of infection and are more pronounced in multidrug-resistant strains of S. aureus, where high expression of proteases is observed. Among various proteases, Serine protease (SspA) and cysteine protease Staphopain B (SspB) are known to play a key role in the biofilm formation and removal of biofilms. In earlier studies, we have reported Dibenzyl (benzo [d] thiazol-2-yl (hydroxy) methyl) phosphonate (DBTMP) exhibits anti-S. aureus and anti-biofilm properties by elevating the expression of the protease. In this study, the effect of DBTMP on the activities of SspA, and SspB of S. aureus was evaluated. The SspA and SspB genes of S. aureus ATCC12600 were sequenced (Genbank accession numbers: MZ456982 and MW574006). In S. aureus active SspA is formed by proteolytic cleavage of immature SspA, to get this mature SspA (mSspA), we have PCR amplified the mSspA sequence from the SspA gene. The mSspA and SspB genes were cloned, expressed, and characterized. The pure recombinant proteins rSspB and rmSspA exhibited a single band in SDS-PAGE with a molecular weight of 40 and 30 KD, respectively. The activities of rmSspA and rSspB are 32.33 and 35.45 Units/mL correspondingly. DBTMP elevated the activities of rmSspA and rSspB by docking with respective enzymes. This compound disrupted the biofilms formed by the multidrug-resistant strains of S. aureus and further prevented biofilm formation. These findings explain that DBTMP possesses anti-S. aureus and anti-biofilm features.
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Affiliation(s)
- G Deepika
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, 517507, India
| | - S Subbarayadu
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, 517507, India
| | - Abhijit Chaudhary
- Department of Microbiology, Sri Padmavati Medical College (Women), SVIMS, Tirupati, Andhra Pradesh, 517507, India
| | - P V G K Sarma
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, 517507, India.
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Wang M, Buist G, van Dijl JM. Staphylococcus aureus cell wall maintenance - the multifaceted roles of peptidoglycan hydrolases in bacterial growth, fitness, and virulence. FEMS Microbiol Rev 2022; 46:6604383. [PMID: 35675307 PMCID: PMC9616470 DOI: 10.1093/femsre/fuac025] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/22/2022] [Accepted: 05/25/2022] [Indexed: 01/07/2023] Open
Abstract
Staphylococcus aureus is an important human and livestock pathogen that is well-protected against environmental insults by a thick cell wall. Accordingly, the wall is a major target of present-day antimicrobial therapy. Unfortunately, S. aureus has mastered the art of antimicrobial resistance, as underscored by the global spread of methicillin-resistant S. aureus (MRSA). The major cell wall component is peptidoglycan. Importantly, the peptidoglycan network is not only vital for cell wall function, but it also represents a bacterial Achilles' heel. In particular, this network is continuously opened by no less than 18 different peptidoglycan hydrolases (PGHs) encoded by the S. aureus core genome, which facilitate bacterial growth and division. This focuses attention on the specific functions executed by these enzymes, their subcellular localization, their control at the transcriptional and post-transcriptional levels, their contributions to staphylococcal virulence and their overall importance in bacterial homeostasis. As highlighted in the present review, our understanding of the different aspects of PGH function in S. aureus has been substantially increased over recent years. This is important because it opens up new possibilities to exploit PGHs as innovative targets for next-generation antimicrobials, passive or active immunization strategies, or even to engineer them into effective antimicrobial agents.
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Affiliation(s)
- Min Wang
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands
| | | | - Jan Maarten van Dijl
- Corresponding author: Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. box 30001, HPC EB80, 9700 RB Groningen, the Netherlands, Tel. +31-50-3615187; Fax. +31-50-3619105; E-mail:
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Sanchez Ramirez DO, Tonetti C, Cruz-Maya I, Guarino V, Peila R, Carletto RA, Varesano A, Vineis C. Design of cysteine-S-sulfonated keratin via pH driven processes: Micro-Structural Properties, biocidal activity and in vitro validation. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Vorasin O, Momphanao K, Katrun P, Kuhakarn C, Jiarpinitnun C. Antibacterial activity evaluation of vinyl sulfones against global predominant methicillin-resistant Staphylococcus aureus USA300. Bioorg Med Chem Lett 2022; 63:128652. [PMID: 35245662 DOI: 10.1016/j.bmcl.2022.128652] [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: 12/09/2021] [Revised: 02/18/2022] [Accepted: 02/27/2022] [Indexed: 11/27/2022]
Abstract
The electrophilic potential of vinyl sulfone permits the rapid capture of cysteine-containing proteins under physiological conditions. These cysteine proteinases play vital roles in bacterial survival and pathogenesis of Staphylococcus aureus (S. aureus) and the global health threat methicillin resistant S. aureus (MRSA). Here in, total of 28 vinyl sulfones were synthesized and subjected to susceptibility testing of pathogenic bacteria, including global epidemic MRSA PFGE strain type USA300 (SF8300). Number of antibacterial vinyl sulfone derivatives were discovered. Among these, nitrile-substituted vinyl phenyl sulfones showed potent antibacterial activity. (E)-3-((4-methoxyphenyl)sulfonyl)acrylonitrile exhibited the strongest potency with MIC of 1.875 µg/mL against methicillin susceptible S. aureus and 3.75 µg/mL against MRSA USA300. Based on the structure-activity relationship analysis, the antibacterial activity of these compounds may involve sulfhydryl conjugation. In addition, the nitrile-substituted vinyl phenyl sulfone could also impair host cell adhesion. With their promising antibacterial activities, these vinyl sulfones have potential for S. aureus and MRSA therapeutics.
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Affiliation(s)
- Onanong Vorasin
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand
| | - Khanchyd Momphanao
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand
| | - Praewpan Katrun
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Chutima Kuhakarn
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand
| | - Chutima Jiarpinitnun
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.
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Ramírez-Larrota JS, Eckhard U. An Introduction to Bacterial Biofilms and Their Proteases, and Their Roles in Host Infection and Immune Evasion. Biomolecules 2022; 12:306. [PMID: 35204806 PMCID: PMC8869686 DOI: 10.3390/biom12020306] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/03/2022] [Accepted: 02/10/2022] [Indexed: 12/15/2022] Open
Abstract
Bacterial biofilms represent multicellular communities embedded in a matrix of extracellular polymeric substances, conveying increased resistance against environmental stress factors but also antibiotics. They are shaped by secreted enzymes such as proteases, which can aid pathogenicity by degrading host proteins of the connective tissue or the immune system. Importantly, both secreted proteases and the capability of biofilm formation are considered key virulence factors. In this review, we focus on the basic aspects of proteolysis and protein secretion, and highlight various secreted bacterial proteases involved in biofilm establishment and dispersal, and how they aid bacteria in immune evasion by degrading immunoglobulins and components of the complement system. Thus, secreted proteases represent not only prominent antimicrobial targets but also enzymes that can be used for dedicated applications in biotechnology and biomedicine, including their use as laundry detergents, in mass spectrometry for the glycoprofiling of antibodies, and the desensitization of donor organs intended for positive crossmatch patients.
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Affiliation(s)
| | - Ulrich Eckhard
- Department of Structural Biology, Molecular Biology Institute of Barcelona, CSIC, Barcelona Science Park, Baldiri Reixac, 15-21, 08028 Barcelona, Spain;
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Jahantigh HR, Faezi S, Habibi M, Mahdavi M, Stufano A, Lovreglio P, Ahmadi K. The Candidate Antigens to Achieving an Effective Vaccine against Staphylococcus aureus. Vaccines (Basel) 2022; 10:vaccines10020199. [PMID: 35214658 PMCID: PMC8876328 DOI: 10.3390/vaccines10020199] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 01/20/2022] [Accepted: 01/26/2022] [Indexed: 12/11/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is an opportunistic pathogen that causes various inflammatory local infections, from those of the skin to postinfectious glomerulonephritis. These infections could result in serious threats, putting the life of the patient in danger. Antibiotic-resistant S. aureus could lead to dramatic increases in human mortality. Antibiotic resistance would explicate the failure of current antibiotic therapies. So, it is obvious that an effective vaccine against S. aureus infections would significantly reduce costs related to care in hospitals. Bacterial vaccines have important impacts on morbidity and mortality caused by several common pathogens, however, a prophylactic vaccine against staphylococci has not yet been produced. During the last decades, the efforts to develop an S. aureus vaccine have faced two major failures in clinical trials. New strategies for vaccine development against S. aureus has supported the use of multiple antigens, the inclusion of adjuvants, and the focus on various virulence mechanisms. We aimed to present a compressive review of different antigens of S. aureus and also to introduce vaccine candidates undergoing clinical trials, from which can help us to choose a suitable and effective candidate for vaccine development against S. aureus.
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Affiliation(s)
- Hamid Reza Jahantigh
- Animal Health and Zoonosis, Department of Veterinary Medicine, University of Bari, 70010 Bari, Italy;
- Interdisciplinary Department of Medicine, Section of Occupational Medicine, University of Bari, 70010 Bari, Italy;
- Correspondence: (H.R.J.); (K.A.); Tel.: +39-3773827669 (H.R.J.)
| | - Sobhan Faezi
- Medical Biotechnology Research Center, School of Paramedicine, Guilan University of Medical Sciences, Rasht 41937, Iran;
| | - Mehri Habibi
- Department of Molecular Biology, Pasteur Institute of Iran, Pasteur Ave., Tehran 13164, Iran;
| | - Mehdi Mahdavi
- Advanced Therapy Medicinal Product (ATMP) Department, Breast Cancer Research Center, Motamed Cancer Institute, Academic Center for Education, Culture and Research (ACECR), Tehran 1517964311, Iran
- Recombinant Vaccine Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran 13164, Iran;
| | - Angela Stufano
- Animal Health and Zoonosis, Department of Veterinary Medicine, University of Bari, 70010 Bari, Italy;
- Interdisciplinary Department of Medicine, Section of Occupational Medicine, University of Bari, 70010 Bari, Italy;
| | - Piero Lovreglio
- Interdisciplinary Department of Medicine, Section of Occupational Medicine, University of Bari, 70010 Bari, Italy;
| | - Khadijeh Ahmadi
- Infectious and Tropical Diseases Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas 79391, Iran
- Correspondence: (H.R.J.); (K.A.); Tel.: +39-3773827669 (H.R.J.)
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Addis MF, Pisanu S, Monistero V, Gazzola A, Penati M, Filipe J, Di Mauro S, Cremonesi P, Castiglioni B, Moroni P, Pagnozzi D, Tola S, Piccinini R. Comparative secretome analysis of Staphylococcus aureus strains with different within-herd intramammary infection prevalence. Virulence 2022; 13:174-190. [PMID: 35030987 PMCID: PMC8765078 DOI: 10.1080/21505594.2021.2024014] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Staphylococcus aureus is a major pathogen causing intramammary infection and mastitis in dairy cows. S. aureus genotypes (GT) can differ significantly in their ability to diffuse and persist in the herd; while the association of virulence gene carriage with epidemiological behavior remains unclear, a role for secreted proteins has been postulated. We characterized the secretome of six S. aureus strains belonging to two genotypes with opposite within-herd prevalence, GTB (high) and GTS (low), corresponding to sequence types (ST) 8 and 398, by high-resolution tandem mass spectrometry and differential analysis with Proteome Discoverer. Data are available via ProteomeXchange with identifier PXD029571. Out of 720 identified proteins, 98 were unique or more abundant in GTB/ST8 and 68 in GTS/ST398. GTB/ST8 released more immunoglobulin-binding proteins, complement and antimicrobial peptide inhibitors, enterotoxins, and metabolic enzymes, while GTS/ST398 released more leukocidins, hemolysins, lipases, and peptidases. Furthermore, GTB/ST8 released the von Willebrand factor protein, staphylokinase, and clumping factor B, while GTS released the staphylococcal coagulase and clumping factor A. Hence, GTB/ST8 secretomes indicated a higher propensity for immune evasion and chronicity and GTS/ST398 secretomes for cellular damage and inflammation, consistent with their epidemiological characteristics. Accordingly, GTS/ST398 secretions were significantly more cytotoxic against bovine PBMCs in vitro. Our findings confirm the crucial role of extracellular virulence factors in S. aureus pathogenesis and highlight the need to investigate their differential release adding to gene carriage for a better understanding of the relationship of S. aureus genotypes with epidemiological behavior and, possibly, disease severity.
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Affiliation(s)
- M Filippa Addis
- Dipartimento Di Medicina Veterinaria, Università Degli Studi Di Milano, Lodi, Italy
| | | | - Valentina Monistero
- Dipartimento Di Medicina Veterinaria, Università Degli Studi Di Milano, Lodi, Italy
| | - Alessandra Gazzola
- Dipartimento Di Medicina Veterinaria, Università Degli Studi Di Milano, Lodi, Italy
| | - Martina Penati
- Dipartimento Di Medicina Veterinaria, Università Degli Studi Di Milano, Lodi, Italy
| | - Joel Filipe
- Dipartimento Di Medicina Veterinaria, Università Degli Studi Di Milano, Lodi, Italy
| | - Susanna Di Mauro
- Dipartimento Di Medicina Veterinaria, Università Degli Studi Di Milano, Lodi, Italy
| | - Paola Cremonesi
- Institute of Agricultural Biology and Biotechnology, National Research Council, Lodi, Italy
| | - Bianca Castiglioni
- Institute of Agricultural Biology and Biotechnology, National Research Council, Lodi, Italy
| | - Paolo Moroni
- Dipartimento Di Medicina Veterinaria, Università Degli Studi Di Milano, Lodi, Italy.,Quality Milk Production Services, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, USA
| | | | - Sebastiana Tola
- Istituto Zooprofilattico Sperimentale Della Sardegna "G. Pegreffi", Sassari, Italy
| | - Renata Piccinini
- Dipartimento Di Medicina Veterinaria, Università Degli Studi Di Milano, Lodi, Italy
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Mendes SR, Eckhard U, Rodríguez-Banqueri A, Guevara T, Czermak P, Marcos E, Vilcinskas A, Xavier Gomis-Rüth F. An engineered protein-based submicromolar competitive inhibitor of the Staphylococcus aureus virulence factor aureolysin. Comput Struct Biotechnol J 2022; 20:534-544. [PMID: 35465156 PMCID: PMC9002140 DOI: 10.1016/j.csbj.2022.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/30/2021] [Accepted: 01/01/2022] [Indexed: 12/18/2022] Open
Abstract
Aureolysin, a secreted metallopeptidase (MP) from the thermolysin family, functions as a major virulence factor in Staphylococcus aureus. No specific aureolysin inhibitors have yet been described, making this an important target for the development of novel antimicrobial drugs in times of rampant antibiotic resistance. Although small-molecule inhibitors are currently more common in the clinic, therapeutic proteins and peptides (TPs) are favourable due to their high selectivity, which reduces off-target toxicity and allows dosage tuning. The greater wax moth Galleria mellonella produces a unique defensive protein known as the insect metallopeptidase inhibitor (IMPI), which selectively inhibits some thermolysins from pathogenic bacteria. We determined the ability of IMPI to inhibit aureolysin in vitro and used crystal structures to ascertain its mechanism of action. This revealed that IMPI uses the “standard mechanism”, which has been poorly characterised for MPs in general. Accordingly, we designed a cohort of 12 single and multiple point mutants, the best of which (I57F) inhibited aureolysin with an estimated inhibition constant (Ki) of 346 nM. Given that animals lack thermolysins, our strategy may facilitate the development of safe TPs against staphylococcal infections, including strains resistant to conventional antibiotics.
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Rom JS, Beenken KE, Ramirez AM, Walker CM, Echols EJ, Smeltzer MS. Limiting protease production plays a key role in the pathogenesis of the divergent clinical isolates of Staphylococcus aureus LAC and UAMS-1. Virulence 2021; 12:584-600. [PMID: 33538230 PMCID: PMC7872036 DOI: 10.1080/21505594.2021.1879550] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/17/2020] [Accepted: 01/10/2021] [Indexed: 01/13/2023] Open
Abstract
Using the USA300, methicillin-resistant Staphylococcus aureus strain LAC, we previously examined the impact of regulatory mutations implicated in biofilm formation on protease production and virulence in a murine sepsis model. Here we examined the impact of these mutations in the USA200, methicillin-sensitive strain UAMS-1. Mutation of agr, mgrA, rot, sarA and sigB attenuated the virulence of UAMS-1. A common characteristic of codY, rot, sigB, and sarA mutants was increased protease production, with mutation of rot having the least impact followed by mutation of codY, sigB and sarA, respectively. Protein A was undetectable in conditioned medium from all four mutants, while extracellular nuclease was only present in the proteolytically cleaved NucA form. The abundance of high molecular weight proteins was reduced in all four mutants. Biofilm formation was reduced in codY, sarA and sigB mutants, but not in the rot mutant. Eliminating protease production partially reversed these phenotypes and enhanced biofilm formation. This was also true in LAC codY, rot, sarA and sigB mutants. Eliminating protease production enhanced the virulence of LAC and UAMS-1 sarA, sigB and rot mutants in a murine sepsis model but did not significantly impact the virulence of the codY mutant in either strain. Nevertheless, these results demonstrate that repressing protease production plays an important role in defining critical phenotypes in diverse clinical isolates of S. aureus and that Rot, SigB and SarA play critical roles in this regard.
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Affiliation(s)
- Joseph S. Rom
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Karen E. Beenken
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Aura M. Ramirez
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Christopher M. Walker
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Ethan J. Echols
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Mark S. Smeltzer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Abstract
SarA, a transcriptional regulator of Staphylococcus aureus, is a major global regulatory system that coordinates the expression of target genes involved in its pathogenicity. Various studies have identified a large number of SarA target genes, but an in-depth characterization of the sarA regulon, including small regulatory RNAs (sRNAs), has not yet been done. In this study, we utilized transcriptome sequencing (RNA-Seq) and chromatin immunoprecipitation sequencing (ChIP-Seq) to determine a comprehensive list of SarA-regulated targets, including both mRNAs and sRNAs. RNA-Seq analysis indicated 390 mRNAs and 51 sRNAs differentially expressed in a ΔsarA mutant, while ChIP-Seq revealed 354 mRNAs and 55 sRNA targets in the S. aureus genome. We confirmed the authenticity of several novel SarA targets by Northern blotting and electrophoretic mobility shift assays. Among them, we characterized repression of sprG2, a gene that encodes the toxin of a type I toxin-antitoxin system, indicating a multilayer lockdown of toxin expression by both SarA and its cognate antitoxin, SprF2. Finally, a novel SarA consensus DNA binding sequence was generated using the upstream promoter sequences of 15 novel SarA-regulated sRNA targets. A genome-wide scan with a deduced SarA motif enabled the discovery of new potential SarA target genes which were not identified in our RNA-Seq and ChIP-Seq analyses. The strength of this new consensus was confirmed with one predicted sRNA target. The RNA-Seq and ChIP-Seq combinatory analysis gives a snapshot of the regulation, whereas bioinformatic analysis reveals a permanent view of targets based on sequence. Altogether these experimental and in silico methodologies are effective to characterize transcriptional factor (TF) regulons and functions. IMPORTANCEStaphylococcus aureus, a commensal and opportunist pathogen, is responsible for a large number of human and animal infections, from benign to severe. Gene expression adaptation during infection requires a complex network of regulators, including transcriptional factors (TF) and sRNAs. TF SarA influences virulence, metabolism, biofilm formation, and resistance to some antibiotics. SarA directly regulates expression of around 20 mRNAs and a few sRNAs. Here, we combined high-throughput expression screening methods combined with binding assays and bioinformatics for an in-depth investigation of the SarA regulon. This combinatory approach allowed the identification of 85 unprecedented mRNAs and sRNAs targets, with at least 14 being primary. Among novel SarA direct targets, we characterized repression of sprG2, a gene that encodes the toxin of a toxin-antitoxin system, indicating a multilayer lockdown of toxin expression by both SarA and its cognate antitoxin, SprF2.
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Patel N, Nair M. The small RNA RsaF regulates the expression of secreted virulence factors in Staphylococcus aureus Newman. J Microbiol 2021; 59:920-930. [PMID: 34554453 DOI: 10.1007/s12275-021-1205-6] [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] [Received: 04/16/2021] [Revised: 07/27/2021] [Accepted: 08/03/2021] [Indexed: 12/26/2022]
Abstract
The pathogenesis of Staphylococcus aureus, from local infections to systemic dissemination, is mediated by a battery of virulence factors that are regulated by intricate mechanisms, which include regulatory proteins and small RNAs (sRNAs) as key regulatory molecules. We have investigated the involvement of sRNA RsaF, in the regulation of pathogenicity genes hyaluronate lyase (hysA) and serine proteaselike protein D (splD), by employing S. aureus strains with disruption and overexpression of rsaF. Staphylococcus aureus strain with disruption of rsaF exhibited marked down-regulation of hysA transcripts by 0.2 to 0.0002 fold, and hyaluronate lyase activity by 0.2-0.1 fold, as well as increased biofilm formation, during growth from log phase to stationery phase. These mutants also displayed down-regulation of splD transcripts by 0.8 to 0.005 fold, and reduced activity of multiple proteases by zymography. Conversely, overexpression of rsaF resulted in a 2- to 4- fold increase in hysA mRNA levels and hyaluronidase activity. Both hysA and splD mRNAs demonstrated an increased stability in RsaF+ strains. In silico RNA-RNA interaction indicated a direct base pairing of RsaF with hysA and splD mRNAs, which was established in electrophoretic mobility shift assays. The findings demonstrate a positive regulatory role for small RNA RsaF in the expression of the virulence factors, HysA and SplD.
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Affiliation(s)
- Niralee Patel
- Department of Microbiology and Biotechnology Centre, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, 390002, India
| | - Mrinalini Nair
- Department of Microbiology and Biotechnology Centre, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, 390002, India.
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Intracellular Staphylococcus aureus employs the cysteine protease staphopain A to induce host cell death in epithelial cells. PLoS Pathog 2021; 17:e1009874. [PMID: 34473800 PMCID: PMC8443034 DOI: 10.1371/journal.ppat.1009874] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 09/15/2021] [Accepted: 08/07/2021] [Indexed: 11/19/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen, which can invade and survive in non-professional and professional phagocytes. Uptake by host cells is thought to contribute to pathogenicity and persistence of the bacterium. Upon internalization by epithelial cells, cytotoxic S. aureus strains can escape from the phagosome, replicate in the cytosol and induce host cell death. Here, we identified a staphylococcal cysteine protease to induce cell death after translocation of intracellular S. aureus into the host cell cytoplasm. We demonstrated that loss of staphopain A function leads to delayed onset of host cell death and prolonged intracellular replication of S. aureus in epithelial cells. Overexpression of staphopain A in a non-cytotoxic strain facilitated intracellular killing of the host cell even in the absence of detectable intracellular replication. Moreover, staphopain A contributed to efficient colonization of the lung in a mouse pneumonia model. In phagocytic cells, where intracellular S. aureus is exclusively localized in the phagosome, staphopain A did not contribute to cytotoxicity. Our study suggests that staphopain A is utilized by S. aureus to exit the epithelial host cell and thus contributes to tissue destruction and dissemination of infection. Staphylococcus aureus is an antibiotic-resistant pathogen that emerges in hospital and community settings and can cause a variety of diseases ranging from skin abscesses to lung inflammation and blood poisoning. The bacterium can asymptomatically colonize the upper respiratory tract and skin of humans and take advantage of opportune conditions, like immunodeficiency or breached barriers, to cause infection. Although S. aureus was not regarded as intracellular bacterium, it can be internalized by human cells and subsequently exit the host cells by induction of cell death, which is considered to cause tissue destruction and spread of infection. The bacterial virulence factors and underlying molecular mechanisms involved in the intracellular lifestyle of S. aureus remain largely unknown. We identified a bacterial cysteine protease to contribute to host cell death of epithelial cells mediated by intracellular S. aureus. Staphopain A induced killing of the host cell after translocation of the pathogen into the cell cytosol, while bacterial proliferation was not required. Further, the protease enhanced survival of the pathogen during lung infection. These findings reveal a novel, intracellular role for the bacterial protease staphopain A.
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Solanki V, Tiwari M, Tiwari V. Subtractive proteomic analysis of antigenic extracellular proteins and design a multi-epitope vaccine against Staphylococcus aureus. Microbiol Immunol 2021; 65:302-316. [PMID: 33368661 DOI: 10.1111/1348-0421.12870] [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: 10/27/2020] [Revised: 12/08/2020] [Accepted: 12/21/2020] [Indexed: 01/04/2023]
Abstract
Staphylococcus aureus is a versatile Gram's positive bacterium that can reside as an asymptomatic colonizer, which can cause a wide range of skin, soft-tissue, and nosocomial infections. A vaccine against multi-drug resistant S. aureus, therefore, is urgently needed. Subtractive proteomics and reverse vaccinology are newly emerging techniques to design multiepitope-based vaccines. The analysis of 7290 proteomes (sensitive and resistant strains), five potent nonhuman homologous vaccine targets [(UNIPORT ID Q2FZL3 (Staphopain B), Q2G2R8 (Staphopain A), Q2FWP0 (uncharacterized leukocidin-like protein 1), Q2G1S6 (uncharacterized protein), and Q2FWV3 (Staphylokinase, putative)] were selected. These proteins were absent in the gut microbiome, which further enhances the significance of these proteins in vaccine design. These five virulence-associated proteins mainly have a role in the invasion mechanism in the host phagocyte cells. MHC I, MHC II, and B cell epitopes were identified in these five proteins. Finalized epitopes were examined by different online servers to screen suitable epitopes for multi-epitope based vaccine design. Shortlisted antigenic and nonallergenic associated epitopes were joined with linkers to design 30 variants (VSA1-VSA30) of multi-epitope vaccine conjugates. The antigenicity and allergenicity of all the 30 vaccine constructs were identified, and VSA30 was found to have the highest antigenicity and lowest allergenicity, and hence was selected for further study. Accordingly, VSA30 was docked with different HLA allelic variants, and the best-docked complex (VSA30-1SYS) was further analyzed by molecular dynamics simulation (MDS). The MDS result confirms the interaction of VSA30 with MHC (HLA-allelic variant). Thus, the final vaccine construct was in silico cloned in the pET28a vector for suitable expression in a heterologous system. Therefore, the designed vaccine construct VSA-30 can be developed as an appropriate vaccine to target S. aureus infection. VSA-30 still needs experimental validation to assure the antigenic and immunogenic properties.
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Affiliation(s)
- Vandana Solanki
- Department of Biochemistry, Central University of Rajasthan, Ajmer, India
| | - Monalisa Tiwari
- Department of Biochemistry, Central University of Rajasthan, Ajmer, India
| | - Vishvanath Tiwari
- Department of Biochemistry, Central University of Rajasthan, Ajmer, India
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Elhawy MI, Molle V, Becker SL, Bischoff M. The Low-Molecular Weight Protein Arginine Phosphatase PtpB Affects Nuclease Production, Cell Wall Integrity, and Uptake Rates of Staphylococcus aureus by Polymorphonuclear Leukocytes. Int J Mol Sci 2021; 22:ijms22105342. [PMID: 34069497 PMCID: PMC8161221 DOI: 10.3390/ijms22105342] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/11/2021] [Accepted: 05/17/2021] [Indexed: 02/03/2023] Open
Abstract
The epidemiological success of Staphylococcus aureus as a versatile pathogen in mammals is largely attributed to its virulence factor repertoire and the sophisticated regulatory network controlling this virulon. Here we demonstrate that the low-molecular-weight protein arginine phosphatase PtpB contributes to this regulatory network by affecting the growth phase-dependent transcription of the virulence factor encoding genes/operons aur, nuc, and psmα, and that of the small regulatory RNA RNAIII. Inactivation of ptpB in S. aureus SA564 also significantly decreased the capacity of the mutant to degrade extracellular DNA, to hydrolyze proteins in the extracellular milieu, and to withstand Triton X-100 induced autolysis. SA564 ΔptpB mutant cells were additionally ingested faster by polymorphonuclear leukocytes in a whole blood phagocytosis assay, suggesting that PtpB contributes by several ways positively to the ability of S. aureus to evade host innate immunity.
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Affiliation(s)
- Mohamed Ibrahem Elhawy
- Institute of Medical Microbiology and Hygiene, Saarland University, 66421 Homburg, Germany; (M.I.E.); (S.L.B.)
- Department of Pathology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt
| | - Virginie Molle
- Laboratory of Pathogen Host Interactions, Université de Montpellier, CNRS, UMR 5235, 34095 Montpellier, France;
| | - Sören L. Becker
- Institute of Medical Microbiology and Hygiene, Saarland University, 66421 Homburg, Germany; (M.I.E.); (S.L.B.)
| | - Markus Bischoff
- Institute of Medical Microbiology and Hygiene, Saarland University, 66421 Homburg, Germany; (M.I.E.); (S.L.B.)
- Correspondence: ; Tel.: +49-6841-1623963
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Frey AM, Chaput D, Shaw LN. Insight into the human pathodegradome of the V8 protease from Staphylococcus aureus. Cell Rep 2021; 35:108930. [PMID: 33826899 PMCID: PMC8054439 DOI: 10.1016/j.celrep.2021.108930] [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: 08/20/2019] [Revised: 12/03/2020] [Accepted: 03/11/2021] [Indexed: 12/03/2022] Open
Abstract
Staphylococcus aureus possesses ten extracellular proteases with mostly unknown targets in the human proteome. To assist with bacterial protease target discovery, we have applied and compared two N-terminomics methods to investigate cleavage of human serum proteins by S. aureus V8 protease, discovering 85 host-protein targets. Among these are virulence-relevant complement, iron sequestration, clotting cascade, and host protease inhibitor proteins. Protein cleavage sites have been identified, providing insight into the disruption of host protein function by V8. Complement proteins are cleaved within peptidase and sushi domains, and host protease inhibitors are cleaved outside their protease-trapping motifs. Our data highlight the potential for further application of N-terminomics in discovery of bacterial protease substrates in other host niches and provide omics-scale insight into the role of the V8 protease in S. aureus pathogenesis. S. aureus-secreted proteases are central to disease causation, but the discovery of their host substrates has been limited. Frey et al. use N-terminomic approaches to uncover human serum targets of the V8 protease that are from virulence-relevant processes such as the host inflammatory network and nutrient sequestration.
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Affiliation(s)
- Andrew Michael Frey
- Department of Cell Biology, Microbiology & Molecular Biology, University of South Florida, Tampa, FL 33620, USA
| | - Dale Chaput
- Department of Cell Biology, Microbiology & Molecular Biology, University of South Florida, Tampa, FL 33620, USA
| | - Lindsey Neil Shaw
- Department of Cell Biology, Microbiology & Molecular Biology, University of South Florida, Tampa, FL 33620, USA.
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Antibody-Dependent Enhancement of Bacterial Disease: Prevalence, Mechanisms, and Treatment. Infect Immun 2021; 89:IAI.00054-21. [PMID: 33558319 DOI: 10.1128/iai.00054-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Antibody-dependent enhancement (ADE) of viral disease has been demonstrated for infections caused by flaviviruses and influenza viruses; however, antibodies that enhance bacterial disease are relatively unknown. In recent years, a few studies have directly linked antibodies with exacerbation of bacterial disease. This ADE of bacterial disease has been observed in mouse models and human patients with bacterial infections. This antibody-mediated enhancement of bacterial infection is driven by various mechanisms that are disparate from those found in viral ADE. This review aims to highlight and discuss historic evidence, potential molecular mechanisms, and current therapies for ADE of bacterial infection. Based on specific case studies, we report how plasmapheresis has been successfully used in patients to ameliorate infection-related symptomatology associated with bacterial ADE. A greater understanding and appreciation of bacterial ADE of infection and disease could lead to better management of infections and inform current vaccine development efforts.
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Cau L, Williams MR, Butcher AM, Nakatsuji T, Kavanaugh JS, Cheng JY, Shafiq F, Higbee K, Hata TR, Horswill AR, Gallo RL. Staphylococcus epidermidis protease EcpA can be a deleterious component of the skin microbiome in atopic dermatitis. J Allergy Clin Immunol 2021; 147:955-966.e16. [PMID: 32634452 PMCID: PMC8058862 DOI: 10.1016/j.jaci.2020.06.024] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 05/19/2020] [Accepted: 06/09/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND Staphylococcus aureus and Staphylococcus epidermidis are the most abundant bacteria found on the skin of patients with atopic dermatitis (AD). S aureus is known to exacerbate AD, whereas S epidermidis has been considered a beneficial commensal organism. OBJECTIVE In this study, we hypothesized that S epidermidis could promote skin damage in AD by the production of a protease that damages the epidermal barrier. METHODS The protease activity of S epidermidis isolates was compared with that of other staphylococcal species. The capacity of S epidermidis to degrade the barrier and induce inflammation was examined by using human keratinocyte tissue culture and mouse models. Skin swabs from atopic and healthy adult subjects were analyzed for the presence of S epidermidis genomic DNA and mRNA. RESULTS S epidermidis strains were observed to produce strong cysteine protease activity when grown at high density. The enzyme responsible for this activity was identified as EcpA, a cysteine protease under quorum sensing control. EcpA was shown to degrade desmoglein-1 and LL-37 in vitro, disrupt the physical barrier, and induce skin inflammation in mice. The abundance of S epidermidis and expression of ecpA mRNA were increased on the skin of some patients with AD, and this correlated with disease severity. Another commensal skin bacterial species, Staphylococcus hominis, can inhibit EcpA production by S epidermidis. CONCLUSION S epidermidis has commonly been regarded as a beneficial skin microbe, whereas S aureus has been considered deleterious. This study suggests that the overabundance of S epidermidis found on some atopic patients can act similarly to S aureus and damage the skin by expression of a cysteine protease.
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Affiliation(s)
- Laura Cau
- Department of Dermatology, University of California San Diego, San Diego, Calif; R&D Department, SILAB, Brive, France
| | - Michael R Williams
- Department of Dermatology, University of California San Diego, San Diego, Calif
| | - Anna M Butcher
- Department of Dermatology, University of California San Diego, San Diego, Calif
| | - Teruaki Nakatsuji
- Department of Dermatology, University of California San Diego, San Diego, Calif
| | - Jeffrey S Kavanaugh
- Department of Immunology and Microbiology, University of Colorado Anschutz, Medical Campus, Aurora, Colo
| | - Joyce Y Cheng
- Department of Dermatology, University of California San Diego, San Diego, Calif
| | - Faiza Shafiq
- Department of Dermatology, University of California San Diego, San Diego, Calif
| | - Kyle Higbee
- Department of Dermatology, University of California San Diego, San Diego, Calif
| | - Tissa R Hata
- Department of Dermatology, University of California San Diego, San Diego, Calif
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado Anschutz, Medical Campus, Aurora, Colo; Department of Veterans Affairs Eastern Colorado Health Care System, Aurora, Colo
| | - Richard L Gallo
- Department of Dermatology, University of California San Diego, San Diego, Calif; Center for Microbiome Innovation, University of California San Diego, San Diego, Calif.
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Structural Determinants of Substrate Specificity of SplF Protease from Staphylococcus aureus. Int J Mol Sci 2021; 22:ijms22042220. [PMID: 33672341 PMCID: PMC7926377 DOI: 10.3390/ijms22042220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/16/2021] [Accepted: 02/19/2021] [Indexed: 11/17/2022] Open
Abstract
Accumulating evidence suggests that six proteases encoded in the spl operon of a dangerous human pathogen, Staphylococcus aureus, may play a role in virulence. Interestingly, SplA, B, D, and E have complementary substrate specificities while SplF remains to be characterized in this regard. Here, we describe the prerequisites of a heterologous expression system for active SplF protease and characterize the enzyme in terms of substrate specificity and its structural determinants. Substrate specificity of SplF is comprehensively profiled using combinatorial libraries of peptide substrates demonstrating strict preference for long aliphatic sidechains at the P1 subsite and significant selectivity for aromatic residues at P3. The crystal structure of SplF was provided at 1.7 Å resolution to define the structural basis of substrate specificity of SplF. The obtained results were compared and contrasted with the characteristics of other Spl proteases determined to date to conclude that the spl operon encodes a unique extracellular proteolytic system.
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Abstract
Staphylococcus aureus controls the progression of infection through the coordinated production of extracellular proteases, which selectively modulate virulence determinant stability. This is evidenced by our previous finding that a protease-null strain has a hypervirulent phenotype in a murine model of sepsis, resulting from the unchecked accumulation of virulence factors. Here, we dissect the individual roles of these proteases by constructing and assessing the pathogenic potential of a combinatorial protease mutant library. When strains were constructed bearing increasing numbers of secreted proteases, we observed a variable impact on infectious capacity, where some exhibited hypervirulence, while others phenocopied the wild-type. The common thread for hypervirulent strains was that each lacked both aureolysin and staphopain A. Upon assessment, we found that the combined loss of these two enzymes alone was necessary and sufficient to engender hypervirulence. Using proteomics, we identified a number of important secreted factors, including SPIN, LukA, Sbi, SEK, and PSMα4, as well as an uncharacterized chitinase-related protein (SAUSA300_0964), to be overrepresented in both the aur scpA and the protease-null mutants. When assessing the virulence of aur scpA SAUSA300_0964 and aur scpA lukA mutants, we found that hypervirulence was completely eliminated, whereas aur scpA spn and aur scpA sek strains elicited aggressive infections akin to the protease double mutant. Collectively, our findings shed light on the influence of extracellular proteases in controlling the infectious process and identifies SAUSA300_0964 as an important new component of the S. aureus virulence factor arsenal.IMPORTANCE A key feature of the pathogenic success of S. aureus is the myriad virulence factors encoded within its genome. These are subject to multifactorial control, ensuring their timely production only within an intended infectious niche. A key node in this network of control is the secreted proteases of S. aureus, who specifically and selectively modulate virulence factor stability. In our previous work we demonstrated that deletion of all 10 secreted proteases results in hypervirulence, since virulence factors exist unchecked, leading to overly aggressive infections. Here, using a combinatorial collection of protease mutants, we reveal that deletion of aureolysin and staphopain A is necessary and sufficient to elicit hypervirulence. Using proteomic techniques, we identify the collection of virulence factors that accumulate in hypervirulent protease mutants, and demonstrate that a well-known toxin (LukA) and an entirely novel secreted element (SAUSA300_0964) are the leading contributors to deadly infections observed in protease-lacking strains.
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Schulze A, Mitterer F, Pombo JP, Schild S. Biofilms by bacterial human pathogens: Clinical relevance - development, composition and regulation - therapeutical strategies. MICROBIAL CELL (GRAZ, AUSTRIA) 2021; 8:28-56. [PMID: 33553418 PMCID: PMC7841849 DOI: 10.15698/mic2021.02.741] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 01/08/2021] [Accepted: 01/12/2021] [Indexed: 12/19/2022]
Abstract
Notably, bacterial biofilm formation is increasingly recognized as a passive virulence factor facilitating many infectious disease processes. In this review we will focus on bacterial biofilms formed by human pathogens and highlight their relevance for diverse diseases. Along biofilm composition and regulation emphasis is laid on the intensively studied biofilms of Vibrio cholerae, Pseudomonas aeruginosa and Staphylococcus spp., which are commonly used as biofilm model organisms and therefore contribute to our general understanding of bacterial biofilm (patho-)physiology. Finally, therapeutical intervention strategies targeting biofilms will be discussed.
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Affiliation(s)
- Adina Schulze
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- A.S. and F.M. contributed equally to this work
| | - Fabian Mitterer
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- A.S. and F.M. contributed equally to this work
| | - Joao P. Pombo
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Stefan Schild
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- BioTechMed Graz, Austria
- Field of Excellence Biohealth – University of Graz, Graz, Austria
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Manoharadas S, Altaf M, Alrefaei AF, Devasia RM, Badjah Hadj AYM, Abuhasil MSA. Concerted dispersion of Staphylococcus aureus biofilm by bacteriophage and 'green synthesized' silver nanoparticles. RSC Adv 2021; 11:1420-1429. [PMID: 35424119 PMCID: PMC8693614 DOI: 10.1039/d0ra09725j] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 12/15/2020] [Indexed: 12/13/2022] Open
Abstract
Staphylococcal biofilms predominantly cause persistent nosocomial infections. The widespread antibiotic resistance followed by its ability to form biofilm in biological and inert surfaces often contributes to major complications in patients and veterinary animals. Strategic importance of bacteriophage therapy against critical staphylococcal infections had been predicted ever since the advent of antibiotic resistant staphylococcal strains. The significance of metal nanoparticles in quenching biofilm associated bacteria was previously reported. In this study, we demonstrate a concerted action of ‘green synthesized’ silver nanoparticles and bacteriophages in removing pre-formed Staphylococcus aureus biofilms from an inert glass surface in a time dependent manner. Our results demonstrate, for the first time, the rapid co-operative dispersion of the bacterial biofilm. In addition, the synergistic activity of the nanoparticles and bacteriophages causes the loss of viability of the biofilm entrapped bacterial cells thus preventing establishment of a new infection and subsequent colonization. This work further opens up a platform for the combinational therapeutic approach with a variety of nanoparticles and bacteriophages against mono or poly bacterial biofilm in environmental, industrial or clinical settings. Formation of biofilm by Staphylococcus aureus ‘Rumba’ on untreated glass surface and a concerted disruption of the biofilm by silver nanoparticle and phage ϕ44AHJD.![]()
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Affiliation(s)
- Salim Manoharadas
- King Saud University, Department of Botany and Microbiology, Central Laboratory RM 55A College of Science Building 5, P.O. Box. 2454 Riyadh 11451 Saudi Arabia +966-14699665 +966-114689170
| | - Mohammad Altaf
- King Saud University, Department of Botany and Microbiology, Central Laboratory RM 55A College of Science Building 5, P.O. Box. 2454 Riyadh 11451 Saudi Arabia +966-14699665 +966-114689170.,King Saud University, Department of Chemistry, College of Science P.O. Box. 2454 Riyadh 11451 Saudi Arabia
| | - Abdulwahed Fahad Alrefaei
- King Saud University, Department of Zoology, College of Science P.O. Box. 2454 Riyadh 11451 Saudi Arabia
| | | | - Ahmed Yacine M Badjah Hadj
- King Saud University, Department of Chemistry, College of Science P.O. Box. 2454 Riyadh 11451 Saudi Arabia
| | - Mohammed Saeed Ali Abuhasil
- King Saud University, Department of Food Science and Nutrition, College of Agriculture and Food Science P.O. Box. 2454 Riyadh 11451 Saudi Arabia
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Alatorre-Barajas JA, Alcántar-Zavala E, Gil-Rivas MG, Estrada-Zavala E, Ochoa-Terán A, Gochi-Ponce Y, Montes-Ávila J, Cabrera A, Trujillo-Navarrete B, Rivera-Lugo YY, Alonso-Núñez G, Reynoso-Soto EA, Medina-Franco JL. Synthesis of covalent bonding MWCNT-oligoethylene linezolid conjugates and their antibacterial activity against bacterial strains. RSC Adv 2021; 11:28912-28924. [PMID: 35478546 PMCID: PMC9038137 DOI: 10.1039/d1ra04691h] [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: 06/17/2021] [Accepted: 08/24/2021] [Indexed: 01/18/2023] Open
Abstract
Nowadays, infectious diseases caused by drug-resistant bacteria have become especially important. Linezolid is an antibacterial drug active against clinically important Gram positive strains; however, resistance showed by these bacteria has been reported. Nanotechnology has improved a broad area of science, such as medicine, developing new drug delivery and transport systems. In this work, several covalently bounded conjugated nanomaterials were synthesized from multiwalled carbon nanotubes (MWCNTs), a different length oligoethylene chain (Sn), and two linezolid precursors (4 and 7), and they were evaluated in antibacterial assays. Interestingly, due to the intrinsic antibacterial activity of the amino-oligoethylene linezolid analogues, these conjugated nanomaterials showed significant antibacterial activity against various tested bacterial strains in a radial diffusion assay and microdilution method, including Gram negative strains as Escherichia coli (11 mm, 6.25 μg mL−1) and Salmonella typhi (14 mm, ≤0.78 μg mL−1), which are not inhibited by linezolid. The results show a significant effect of the oligoethylene chain length over the antibacterial activity. Molecular docking of amino-oligoethylene linezolid analogs shows a more favorable interaction of the S2-7 analog in the PTC of E. coli. New MWCNTs amino-oligoethylene linezolid conjugates having outstanding activity against Gram negative strains.![]()
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Affiliation(s)
- José A. Alatorre-Barajas
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Eleazar Alcántar-Zavala
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - M. Graciela Gil-Rivas
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Edgar Estrada-Zavala
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Sinaloa, Culiacán, Sin, Mexico
| | - Adrián Ochoa-Terán
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Y. Gochi-Ponce
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Julio Montes-Ávila
- Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Sinaloa, Culiacán, Sin, Mexico
| | - Alberto Cabrera
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Balter Trujillo-Navarrete
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Yazmin Yorely Rivera-Lugo
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - Gabriel Alonso-Núñez
- Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, B. C, Mexico
| | - Edgar A. Reynoso-Soto
- Centro de Graduados e Investigación en Química, Tecnológico Nacional de México/ IT de Tijuana, Tijuana, B. C., Mexico
| | - J. L. Medina-Franco
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
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Tallet L, Gribova V, Ploux L, Vrana NE, Lavalle P. New Smart Antimicrobial Hydrogels, Nanomaterials, and Coatings: Earlier Action, More Specific, Better Dosing? Adv Healthc Mater 2021; 10:e2001199. [PMID: 33043612 DOI: 10.1002/adhm.202001199] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/01/2020] [Indexed: 12/21/2022]
Abstract
To fight against antibiotic-resistant bacteria adhering and developing on medical devices, which is a growing problem worldwide, researchers are currently developing new "smart" materials and coatings. They consist in delivery of antimicrobial agents in an intelligent way, i.e., only when bacteria are present. This requires the use of new and sophisticated tools combining antimicrobial agents with lipids or polymers, synthetic and/or natural. In this review, three classes of innovative materials are described: hydrogels, nanomaterials, and thin films. Moreover, smart antibacterial materials can be classified into two groups depending on the origin of the stimulus used: those that respond to a nonbiological stimulus (light, temperature, electric and magnetic fields) and those that respond to a biological stimulus related to the presence of bacteria, such as changes in pH or bacterial enzyme secretion. The bacteria presence can induce a pH change that constitutes a first potential biological trigger allowing the system to become active. A second biological trigger signal consists in enzymes produced by bacteria themselves. A complete panel of recent studies will be given focusing on the design of such innovative smart materials that are sensitive to biological triggers.
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Affiliation(s)
- Lorène Tallet
- Institut National de la Santé et de la Recherche Médicale INSERM Unité 1121 Biomaterials and Bioengineering 11 rue Humann Strasbourg Cedex 67085 France
- Faculté de Chirurgie Dentaire Université de Strasbourg Strasbourg 67000 France
| | - Varvara Gribova
- Institut National de la Santé et de la Recherche Médicale INSERM Unité 1121 Biomaterials and Bioengineering 11 rue Humann Strasbourg Cedex 67085 France
- Faculté de Chirurgie Dentaire Université de Strasbourg Strasbourg 67000 France
| | - Lydie Ploux
- Institut National de la Santé et de la Recherche Médicale INSERM Unité 1121 Biomaterials and Bioengineering 11 rue Humann Strasbourg Cedex 67085 France
- Faculté de Chirurgie Dentaire Université de Strasbourg Strasbourg 67000 France
- Centre national de la recherche Scientifique CNRS 23 rue du Loess Strasbourg 67200 France
| | - Nihal Engin Vrana
- SPARTHA Medical 14B Rue de la Canardiere Strasbourg Cedex 67100 France
| | - Philippe Lavalle
- Institut National de la Santé et de la Recherche Médicale INSERM Unité 1121 Biomaterials and Bioengineering 11 rue Humann Strasbourg Cedex 67085 France
- Faculté de Chirurgie Dentaire Université de Strasbourg Strasbourg 67000 France
- SPARTHA Medical 14B Rue de la Canardiere Strasbourg Cedex 67100 France
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Ramirez AM, Beenken KE, Byrum SD, Tackett AJ, Shaw LN, Gimza BD, Smeltzer MS. SarA plays a predominant role in controlling the production of extracellular proteases in the diverse clinical isolates of Staphylococcus aureus LAC and UAMS-1. Virulence 2020; 11:1738-1762. [PMID: 33258416 PMCID: PMC7738309 DOI: 10.1080/21505594.2020.1855923] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/12/2020] [Accepted: 11/18/2020] [Indexed: 12/26/2022] Open
Abstract
Using DNA affinity chromatography we demonstrate that the S. aureus regulatory proteins MgrA, Rot, SarA, and SarS bind DNA baits derived from the promoter regions associated with the genes encoding aureolysin, ScpAB, SspABC, and SplA-F. Three of four baits also bound SarR and SarZ, the exception in both cases being the ScpAB-associated bait. Using the USA300, methicillin-resistant strain LAC and the USA200, methicillin-sensitive strain UAMS-1, we generated mutations in the genes encoding each of these proteins alone and in combination with sarA and examined the impact on protease production, the accumulation of high molecular weight proteins, and biofilm formation. These studies confirmed that multiple regulatory loci are involved in limiting protease production to a degree that impacts all of these phenotypes, but also demonstrate that sarA plays a predominant role in this regard. Using sarA mutants unable to produce individual proteases alone and in combination with each other, we also demonstrate that the increased production of aureolysin and ScpA is particularly important in defining the biofilm-deficient phenotype of LAC and UAMS-1 sarA mutants, while aureolysin alone plays a key role in defining the reduced accumulation of alpha toxin and overall cytotoxicity as assessed using both osteoblasts and osteoclasts.
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Affiliation(s)
- Aura M. Ramirez
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Karen E. Beenken
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Stephanie D. Byrum
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, and Arkansas Children’s Research Institute, Little Rock, AR, USA
| | - Alan J. Tackett
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, and Arkansas Children’s Research Institute, Little Rock, AR, USA
| | - Lindsey N. Shaw
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL
| | - Brittney D. Gimza
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL
| | - Mark S. Smeltzer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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Hamann HJ, Abutaleb NS, Pal R, Seleem MN, Ramachandran PV. β,γ-Diaryl α-methylene-γ-butyrolactones as potent antibacterials against methicillin-resistant Staphylococcus aureus. Bioorg Chem 2020; 104:104183. [PMID: 32971415 DOI: 10.1016/j.bioorg.2020.104183] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/19/2020] [Accepted: 08/08/2020] [Indexed: 10/23/2022]
Abstract
A selected series of racemic α-methylene-γ-butyrolactones (AMGBL) synthesized via allylboration or allylindation reactions were screened against methicillin-resistant Staphylococcus aureus (MRSA) USA300. Unlike natural AMGBLs, such as parthenolide, synthetic analogs bearing aryl moieties at the β- and γ-positions are potent against MRSA. The most potent molecules were comparable to vancomycin and linezolid, the drugs of the last resort for MRSA infections, in their effectiveness with minimum inhibitory concentrations (MICs) ranging from 3.0 to 5.2 μM. These lactones also exhibited potent antibacterial activity against other clinically important multidrug-resistant Gram-positive bacteria (except enterococci), while also showing high tolerability to mammalian cells. Several of these molecules surpassed vancomycin in their rapid killing of the high MRSA inoculum (2 h vs 12 h) in a standard time-kill kinetics assay, with compounds 1l and 1m significantly reducing the intracellular burden of MRSA by about 98-99%, at low concentrations. Additionally, the compounds surpassed vancomycin in inhibiting staphylococcal protease production, indicating that synthetic methylene lactones warrant further investigations as promising anti-MRSA candidates.
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Affiliation(s)
- Henry J Hamann
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907-2084, United States
| | - Nader S Abutaleb
- Department of Comparative Pathobiology, College of Veterinary Medicine, 625 Harrison Street, West Lafayette, IN 47907, United States
| | - Rusha Pal
- Department of Comparative Pathobiology, College of Veterinary Medicine, 625 Harrison Street, West Lafayette, IN 47907, United States
| | - Mohamed N Seleem
- Department of Comparative Pathobiology, College of Veterinary Medicine, 625 Harrison Street, West Lafayette, IN 47907, United States; Purdue Institute of Inflammation, Immunology, and Infectious Disease, West Lafayette, IN 47907, United States.
| | - P Veeraraghavan Ramachandran
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907-2084, United States; Purdue Institute of Inflammation, Immunology, and Infectious Disease, West Lafayette, IN 47907, United States.
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