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Girma A. Staphylococcus aureus: Current perspectives on molecular pathogenesis and virulence. Cell Surf 2025; 13:100137. [PMID: 39758277 PMCID: PMC11699754 DOI: 10.1016/j.tcsw.2024.100137] [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: 11/07/2024] [Revised: 12/04/2024] [Accepted: 12/07/2024] [Indexed: 01/07/2025] Open
Abstract
Staphylococcus aureus has evolved a sophisticated regulatory system to control its virulence. One of the main roles of this interconnected network is to sense and respond to diverse environmental signals by altering the synthesis of virulence components required for survival in the host, including cell surface adhesins, extracellular enzymes and toxins. The accessory gene regulator (agr), a quorum sensing system that detects the local concentration of a cyclic peptide signaling molecule, is one of the well-studied of these S. aureus regulatory mechanisms. By using this system, S. aureus is able to sense its own population density and translate this information into a specific pattern of gene expression. In addition to Agr, this pathogen senses specific stimuli through various two-component systems and synchronizes responses with alternative sigma factors and cytoplasmic regulators of the SarA protein family. These different regulatory mechanisms combine host and environmental information into a network that guarantees the best possible response of pathogens to changing circumstances. In this article, an overview of the most significant and thoroughly studied regulatory systems of S. aureus is provided, along with a summary of their roles in host interactions.
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Affiliation(s)
- Abayeneh Girma
- Department of Biology, College of Natural and Computational Science, Mekdela Amba University, P.O. Box 32, Tulu Awuliya, Ethiopia
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2
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Beenken KE, Smeltzer MS. Staphylococcus aureus Biofilm-Associated Infections: Have We Found a Clinically Relevant Target? Microorganisms 2025; 13:852. [PMID: 40284688 PMCID: PMC12029350 DOI: 10.3390/microorganisms13040852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2025] [Revised: 03/26/2025] [Accepted: 04/02/2025] [Indexed: 04/29/2025] Open
Abstract
Staphylococcus aureus is one of the most diverse bacterial pathogens. This is reflected in its ability to cause a wide array of infections and in genotypic and phenotypic differences between clinical isolates that extend beyond their antibiotic resistance status. Many S. aureus infections, including those involving indwelling medical devices, are therapeutically defined by the formation of a biofilm. This is reflected in the number of reports focusing on S. aureus biofilm formation and biofilm-associated infections. These infections are characterized by a level of intrinsic resistance that compromises conventional antibiotic therapy irrespective of acquired resistance, suggesting that an inhibitor of biofilm formation would have tremendous clinical value. Many reports have described large-scale screens aimed at identifying compounds that limit S. aureus biofilm formation, but relatively few examined whether the limitation was sufficient to overcome this intrinsic resistance. Similarly, while many of these reports examined the impact of putative inhibitors on S. aureus phenotypes, very few took a focused approach to identify and optimize an effective inhibitor of specific biofilm-associated targets. Such approaches are dependent on validating a target, hopefully one that is not restricted by the diversity of S. aureus as a bacterial pathogen. Rigorous biological validation of such a target would allow investigators to virtually screen vast chemical libraries to identify potential inhibitors that warrant further investigation based on their predicted function. Here, we summarize reports describing S. aureus regulatory loci implicated in biofilm formation to assess whether they are viable targets for the development of an anti-biofilm therapeutic strategy with an emphasis on whether sarA has been sufficiently validated to warrant consideration in this important clinical context.
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Affiliation(s)
- Karen E. Beenken
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA;
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Mark S. Smeltzer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA;
- Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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Zhang L, Sun M, Song W, Wu R, Yu B, Duan S, Xu FJ. Natural Macromolecule-Based Lubricative Catheter Coatings with Sustained Adaptive Antibacterial Property for Encrustation and Infection Prevention. Adv Healthc Mater 2025; 14:e2402359. [PMID: 39696923 DOI: 10.1002/adhm.202402359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Revised: 12/08/2024] [Indexed: 12/20/2024]
Abstract
Catheter-associated urinary tract infection (CAUTI) are a global health burden. Moreover, the friction during urinary catheter placement also induces pain in patients. Therefore, there is a pressing need to develop effective antibacterial and lubricative coatings on the surface of urinary catheter. In this work, a facile volatilization film-forming method is used to construct coatings on catheter surfaces. Xanthan gum (SR), which has good lubricative and antifouling properties, is oxidized to cross-link with multi-amino compounds, gentamicin (GS), and gelatin, to fabricate uniform coatings on silicone catheters (SR-GXGs). The structures of SR-GXGs are regulated by the components of the film formation solutions. The bacterial metabolism can produce an acidic micro-environment that can regulate GS release to achieve on-demand administration. SR-GXG2 can eliminate 99.99% of common pathogenic bacteria and reduce the dynamic friction coefficient by 98.73%, and showed high stability in a 7-day flowing experiment. In addition, the universality of this method is demonstrated on various kinds of matrices with different shapes, including commercial urethral catheters. In vivo, SR-GXG2 can effectively avoid urinary tract injury and encrustation phenomenon because of its good anti-infection, antifouling, and lubricative properties. This work provides a promising strategy for developing multifunctional antibacterial coatings on medical catheters.
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Affiliation(s)
- Lujiao Zhang
- State Key Laboratory of Organic-Inorganic Composites, Key Lab of Biomedical Materials of Natural Macromolecules (Beijing University of Chemical Technology), Ministry of Education, Beijing Laboratory of Biomedical Materials, Beijing, 100029, China
- Biomaterials and Regenerative Engineering Alliance Laboratory, School of Engineering, Westlake University, Hangzhou, Zhejiang, 310030, China
| | - Meizhou Sun
- State Key Laboratory of Organic-Inorganic Composites, Key Lab of Biomedical Materials of Natural Macromolecules (Beijing University of Chemical Technology), Ministry of Education, Beijing Laboratory of Biomedical Materials, Beijing, 100029, China
| | - Weizhuo Song
- State Key Laboratory of Organic-Inorganic Composites, Key Lab of Biomedical Materials of Natural Macromolecules (Beijing University of Chemical Technology), Ministry of Education, Beijing Laboratory of Biomedical Materials, Beijing, 100029, China
| | - Ruonan Wu
- State Key Laboratory of Organic-Inorganic Composites, Key Lab of Biomedical Materials of Natural Macromolecules (Beijing University of Chemical Technology), Ministry of Education, Beijing Laboratory of Biomedical Materials, Beijing, 100029, China
| | - Bingran Yu
- State Key Laboratory of Organic-Inorganic Composites, Key Lab of Biomedical Materials of Natural Macromolecules (Beijing University of Chemical Technology), Ministry of Education, Beijing Laboratory of Biomedical Materials, Beijing, 100029, China
| | - Shun Duan
- State Key Laboratory of Organic-Inorganic Composites, Key Lab of Biomedical Materials of Natural Macromolecules (Beijing University of Chemical Technology), Ministry of Education, Beijing Laboratory of Biomedical Materials, Beijing, 100029, China
| | - Fu-Jian Xu
- State Key Laboratory of Organic-Inorganic Composites, Key Lab of Biomedical Materials of Natural Macromolecules (Beijing University of Chemical Technology), Ministry of Education, Beijing Laboratory of Biomedical Materials, Beijing, 100029, China
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Beenken KE, Campbell MJ, Smeltzer MS. The ability of sarA to limit protease production plays a key role in the pathogenesis of Staphylococcus aureus osteomyelitis irrespective of the functional status of agr. Infect Immun 2025; 93:e0047324. [PMID: 39611695 PMCID: PMC11784413 DOI: 10.1128/iai.00473-24] [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: 10/25/2024] [Accepted: 11/04/2024] [Indexed: 11/30/2024] Open
Abstract
We demonstrate that mutation of the staphylococcal accessory regulator A (sarA) in the USA300 strain LAC limits virulence in a murine osteomyelitis model to a greater extent than mutation of the accessory gene regulator (agr) and that it does so irrespective of the functional status of agr. Protease production was decreased in the agr mutant but increased in sarA and sarA/agr mutants to a degree that limited biofilm formation. Extracellular protein A (eSpa) and full-length extracellular nuclease (Nuc1) were absent in the conditioned medium (CM) from sarA and sarA/agr mutants, and their abundance was restored in both mutants by eliminating protease production. Cytotoxicity of CM for osteoblasts and osteoclasts was also reduced in both mutants. Cytotoxicity was restored in a protease-deficient sarA mutant but not in the protease-deficient sarA/agr mutant. Reduced cytotoxicity was correlated with the reduced abundance of full-length α-toxin, LukF, and LukS in sarA and sarA/agr mutants. The abundance of these toxins in their full-length form was increased in the protease-deficient sarA mutant by comparison to LAC, demonstrating that mutation of sarA increases the production of these toxins but increased protease production limits their abundance in full-length and presumably functional forms. Most importantly, eliminating protease production enhanced the virulence of sarA and sarA/agr mutants, but had no impact in the agr mutant. We conclude that a key factor in the attenuation of LAC sarA and sarA/agr mutants in osteomyelitis is the increased production of extracellular proteases and its impact on virulence factors that contribute to biofilm formation and cytotoxicity.IMPORTANCEThe persistent emergence of antibiotic-resistant strains has rekindled interest in anti-virulence strategies to combat S. aureus infections. Numerous reports describe anti-virulence strategies focusing on key regulatory elements that globally influence virulence factor production, the two most commonly targeted being the accessory gene regulator (agr) and the staphylococcal accessory regulator A (sarA). We demonstrate that mutation of sarA limits virulence to a greater extent than mutation of agr and that this can be attributed to increased protease production in both sarA and sarA/agr mutants. This illustrates the critical role of sarA in protease-mediated post-translational regulation in S. aureus. It also suggests that an inhibitor of sarA would be more effective than an inhibitor of agr in overcoming the therapeutic recalcitrance of osteomyelitis and that such an inhibitor would remain effective even in the context of agr mutants known to arise in vivo during the transition from acute to chronic infection.
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Affiliation(s)
- Karen E. Beenken
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Mara J. Campbell
- 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
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Beenken KE, Campbell MJ, Byrum SD, Edmondson RD, Mackintosh SG, Tackett AJ, Smeltzer MS. Staphylococcus aureus Proteins Implicated in the Reduced Virulence of sarA and sarA/agr Mutants in Osteomyelitis. Microorganisms 2025; 13:181. [PMID: 39858949 PMCID: PMC11767506 DOI: 10.3390/microorganisms13010181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2024] [Revised: 01/06/2025] [Accepted: 01/14/2025] [Indexed: 01/27/2025] Open
Abstract
Using a murine osteomyelitis model, we recently demonstrated that Staphylococcus aureus sarA and sarA/agr mutants generated in the USA300 strain LAC are attenuated to a greater extent than an isogenic agr mutant and that this can be attributed to a significant extent to the increased production of extracellular proteases in both mutants. Based on this, we used a mass-based proteomics approach to compare the proteomes of LAC, its isogenic agr, sarA, and sarA/agr mutants, and isogenic derivatives of all four of these strains unable to produce the extracellular proteases aureolysin, SspA, SspB, ScpA, or SplA-F. This allowed us to identify proteins that were present in reduced amounts in sarA, and sarA/agr mutants owing to the increased production of extracellular proteases. A total of 1039 proteins were detected in conditioned media (CM) from overnight cultures of LAC, and protease-mediated degradation was shown to contribute to the reduced abundance of 224 of these (21.6%) in CM from the sarA and sarA/agr mutants. Among these were specific proteins previously implicated in the pathogenesis and therapeutic recalcitrance of S. aureus osteomyelitis. This demonstrates that the ability of sarA to limit protease production plays a key role in post-translational remodeling of the S. aureus proteome to a degree that can be correlated with reduced virulence in our osteomyelitis model, and that it does so irrespective of the functional status of agr. This also suggests that at least some of these 224 proteins may be viable targets for prophylactic or therapeutic intervention.
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Affiliation(s)
- Karen E. Beenken
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (M.J.C.); (M.S.S.)
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA (R.D.E.); (S.G.M.); (A.J.T.)
| | - Mara J. Campbell
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (M.J.C.); (M.S.S.)
| | - Stephanie D. Byrum
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA (R.D.E.); (S.G.M.); (A.J.T.)
| | - Rick D. Edmondson
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA (R.D.E.); (S.G.M.); (A.J.T.)
| | - Samuel G. Mackintosh
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA (R.D.E.); (S.G.M.); (A.J.T.)
| | - Alan J. Tackett
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA (R.D.E.); (S.G.M.); (A.J.T.)
| | - Mark S. Smeltzer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (M.J.C.); (M.S.S.)
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Stevens EJ, Li JD, Hector TE, Drew GC, Hoang K, Greenrod STE, Paterson S, King KC. Within-host competition causes pathogen molecular evolution and perpetual microbiota dysbiosis. THE ISME JOURNAL 2025; 19:wraf071. [PMID: 40244062 PMCID: PMC12066030 DOI: 10.1093/ismejo/wraf071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2025] [Revised: 03/31/2025] [Accepted: 04/11/2025] [Indexed: 04/18/2025]
Abstract
Pathogens newly invading a host must compete with resident microbiota. This within-host microbial warfare could lead to more severe disease outcomes or constrain the evolution of virulence. By passaging a widespread pathogen (Staphylococcus aureus) and a natural microbiota community across populations of nematode hosts, we show that the pathogen displaced microbiota and reduced species richness, but maintained its virulence across generations. Conversely, pathogen populations and microbiota passaged in isolation caused more host harm relative to their respective no-host controls. For the evolved pathogens, this increase in virulence was partly mediated by enhanced biofilm formation and expression of the global virulence regulator agr. Whole genome sequencing revealed shifts in the mode of selection from directional (on pathogens evolving in isolation) to fluctuating (on pathogens evolving in host microbiota). This approach also revealed that competitive interactions with the microbiota drove early pathogen genomic diversification. Metagenome sequencing of the passaged microbiota shows that evolution in pathogen-infected hosts caused a significant reduction in community stability (dysbiosis), along with restrictions on the co-existence of some species based on nutrient competition. Our study reveals how microbial competition during novel infection could determine the patterns and processes of evolution with major consequences for host health.
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Affiliation(s)
- Emily J Stevens
- Department of Biology, University of Oxford, Oxford, Oxfordshire, OX1 3SZ, United Kingdom
- School of Life Sciences, Keele University, Keele, Staffordshire, ST5 5BG, United Kingdom
| | - Jingdi D Li
- Department of Biology, University of Oxford, Oxford, Oxfordshire, OX1 3SZ, United Kingdom
| | - Tobias E Hector
- Department of Biology, University of Oxford, Oxford, Oxfordshire, OX1 3SZ, United Kingdom
| | - Georgia C Drew
- Department of Biology, University of Oxford, Oxford, Oxfordshire, OX1 3SZ, United Kingdom
| | - Kim Hoang
- Division of Infectious Diseases, Emory University School of Medicine, Atlanta, GA, 30322, United States
| | - Samuel T E Greenrod
- Department of Biology, University of Oxford, Oxford, Oxfordshire, OX1 3SZ, United Kingdom
| | - Steve Paterson
- Institute of Infection, Veterinary, and Ecological Sciences, University of Liverpool, Liverpool, Wirral, CH64 7TE, United Kingdom
| | - Kayla C King
- Department of Biology, University of Oxford, Oxford, Oxfordshire, OX1 3SZ, United Kingdom
- Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
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Campbell MJ, Beenken KE, Ramirez AM, Smeltzer MS. Increased production of aureolysin and staphopain A is a primary determinant of the reduced virulence of Staphylococcus aureus sarA mutants in osteomyelitis. mBio 2024; 15:e0338323. [PMID: 38415646 PMCID: PMC11005355 DOI: 10.1128/mbio.03383-23] [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: 12/12/2023] [Accepted: 02/09/2024] [Indexed: 02/29/2024] Open
Abstract
We previously demonstrated that mutation of sarA in Staphylococcus aureus limits biofilm formation, cytotoxicity for osteoblasts and osteoclasts, and virulence in osteomyelitis, and that all of these phenotypes can be attributed to the increased production of extracellular proteases. Here we extend these studies to assess the individual importance of these proteases alone and in combination with each other using the methicillin-resistant USA300 strain LAC, the methicillin-susceptible USA200 strain UAMS-1, and isogenic sarA mutants that were also unable to produce aureolysin (Aur), staphopain A (ScpA), staphylococcal serine protease A (subsp.), staphopain B (SspB), and the staphylococcal serine protease-like proteins A-F (SplA-F). Biofilm formation was restored in LAC and UAMS-1 sarA mutants by subsequent mutation of aur and scpA, while mutation of aur had the greatest impact on cytotoxicity to mammalian cells, particularly with conditioned medium (CM) from the more cytotoxic strain LAC. However, SDS-PAGE and western blot analysis of CM confirmed that mutation of sspAB was also required to mimic the phenotype of sarA mutants unable to produce any extracellular proteases. Nevertheless, in a murine model of post-traumatic osteomyelitis, mutation of aur and scpA had the greatest impact on restoring the virulence of LAC and UAMS-1 sarA mutants, with concurrent mutation of sspAB and the spl operon having relatively little effect. These results demonstrate that the increased production of Aur and ScpA in combination with each other is a primary determinant of the reduced virulence of S. aureus sarA mutants in diverse clinical isolates including both methicillin-resistant and methicillin-susceptible strains.IMPORTANCEPrevious work established that SarA plays a primary role in limiting the production of extracellular proteases to prevent them from limiting the abundance of S. aureus virulence factors. Eliminating the production of all 10 extracellular proteases in the methicillin-resistant strain LAC has also been shown to enhance virulence in a murine sepsis model, and this has been attributed to the specific proteases Aur and ScpA. The importance of this work lies in our demonstration that the increased production of these same proteases largely accounts for the decreased virulence of sarA mutants in a murine model of post-traumatic osteomyelitis not only in LAC but also in the methicillin-susceptible human osteomyelitis isolate UAMS-1. This confirms that sarA-mediated repression of Aur and ScpA production plays a critical role in the posttranslational regulation of S. aureus virulence factors in diverse clinical isolates and diverse forms of S. aureus infection.
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Affiliation(s)
- Mara J. Campbell
- 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
| | - Mark S. Smeltzer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Elkhalifa ME, Ashraf M, Ahmed A, Usman A, Hamdoon AA, Elawad MA, Almalki MG, Mosa OF, Niyazov LN, Ayaz M. Polyphenols and their nanoformulations as potential antibiofilm agents against multidrug-resistant pathogens. Future Microbiol 2024; 19:255-279. [PMID: 38305223 DOI: 10.2217/fmb-2023-0175] [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: 08/09/2023] [Accepted: 10/13/2023] [Indexed: 02/03/2024] Open
Abstract
The emergence of multidrug-resistant (MDR) pathogens is a major problem in the therapeutic management of infectious diseases. Among the bacterial resistance mechanisms is the development of an enveloped protein and polysaccharide-hydrated matrix called a biofilm. Polyphenolics have demonstrated beneficial antibacterial effects. Phenolic compounds mediate their antibiofilm effects via disruption of the bacterial membrane, deprivation of substrate, protein binding, binding to adhesion complex, viral fusion blockage and interactions with eukaryotic DNA. However, these compounds have limitations of chemical instability, low bioavailability, poor water solubility and short half-lives. Nanoformulations offer a promising solution to overcome these challenges by enhancing their antibacterial potential. This review summarizes the antibiofilm role of polyphenolics, their underlying mechanisms and their potential role as resistance-modifying agents.
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Affiliation(s)
- Modawy Em Elkhalifa
- Public Health Department, Health Sciences College at Al-Leith, Umm Al-Qura University, Al leith, KSA
- Faculty of Public and Environmental Health, University of Khartoum, Khartoum, Sudan
| | - Muhammad Ashraf
- Department of Pharmacy, University of Malakand, Chakdara, Dir (L), KP, 18800, Pakistan
| | - Alshebli Ahmed
- Public Health Department, Health Sciences College at Al-Leith, Umm Al-Qura University, Al leith, KSA
- Faculty of Public and Environmental Health, University of Khartoum, Khartoum, Sudan
| | - Assad Usman
- Department of Pharmacy, University of Malakand, Chakdara, Dir (L), KP, 18800, Pakistan
| | - Alashary Ae Hamdoon
- Public Health Department, Health Sciences College at Al-Leith, Umm Al-Qura University, Al leith, KSA
- Faculty of Public and Environmental Health, University of Khartoum, Khartoum, Sudan
| | - Mohammed A Elawad
- Public Health Department, Health Sciences College at Al-Leith, Umm Al-Qura University, Al leith, KSA
- Faculty of Public and Environmental Health, University of Khartoum, Khartoum, Sudan
| | - Meshari G Almalki
- Public Health Department, Health Sciences College at Al-Leith, Umm Al-Qura University, Al leith, KSA
| | - Osama F Mosa
- Public Health Department, Health Sciences College at Al-Leith, Umm Al-Qura University, Al leith, KSA
| | - Laziz N Niyazov
- Medical Chemistry Department, Bukhara State Medical Institute Named After Abu Ali Ibn Sino, Bukhara, Uzbekistan
| | - Muhammad Ayaz
- Department of Pharmacy, University of Malakand, Chakdara, Dir (L), KP, 18800, Pakistan
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Liu P, Kang X, Chen X, Luo X, Li C, Wang G. Quercetin targets SarA of methicillin-resistant Staphylococcus aureus to mitigate biofilm formation. Microbiol Spectr 2024; 12:e0272223. [PMID: 38018987 PMCID: PMC10783115 DOI: 10.1128/spectrum.02722-23] [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: 06/30/2023] [Accepted: 10/16/2023] [Indexed: 11/30/2023] Open
Abstract
IMPORTANCE Anti-biofilm is an important strategy against Staphylococcus aureus chronic infection. SarA is a positive regulator of biofilm formation in S. aureus. In this study, we identified the SarA inhibitor quercetin using computer simulation screening. Previous studies have shown that quercetin inhibits biofilm; however, the underlying mechanism remains unknown. This study revealed the inhibitory effect of quercetin on the SarA protein. We also isolated the SarA protein and confirmed its interaction with quercetin in vitro. Besides, the inhibitory effect of quercetin on the transcription and translation levels of the SarA protein was also determined. The effects of quercetin on S. aureus biofilm inhibition and biofilm components were consistent with the changes in the transcription level of biofilm-related genes regulated by SarA. In summary, our study revealed the mechanism by which quercetin affects biofilm formation by inhibiting the transcriptional regulator SarA of S. aureus.
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Affiliation(s)
- Panpan Liu
- College of Animal Science and Technology, Ningxia University, Yinchuan, China
| | - Xinyun Kang
- College of Animal Science and Technology, Ningxia University, Yinchuan, China
| | - Xiaohui Chen
- College of Animal Science and Technology, Ningxia University, Yinchuan, China
| | - Xiaofeng Luo
- College of Animal Science and Technology, Ningxia University, Yinchuan, China
| | - Caixia Li
- College of Animal Science and Technology, Ningxia University, Yinchuan, China
| | - Guiqin Wang
- College of Animal Science and Technology, Ningxia University, Yinchuan, China
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10
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Campbell MJ, Beenken KE, Spencer HJ, Jayana B, Hester H, Sahukhal GS, Elasri MO, Smeltzer MS. Comparative evaluation of small molecules reported to be inhibitors of Staphylococcus aureus biofilm formation. Microbiol Spectr 2024; 12:e0314723. [PMID: 38059629 PMCID: PMC10782960 DOI: 10.1128/spectrum.03147-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/09/2023] [Indexed: 12/08/2023] Open
Abstract
IMPORTANCE Because biofilm formation is such a problematic feature of Staphylococcus aureus infections, much effort has been put into identifying biofilm inhibitors. However, the results observed with these compounds are often reported in isolation, and the methods used to assess biofilm formation vary between labs, making it impossible to assess relative efficacy and prioritize among these putative inhibitors for further study. The studies we report address this issue by directly comparing putative biofilm inhibitors using a consistent in vitro assay. This assay was previously shown to maximize biofilm formation, and the results observed with this assay have been proven to be relevant in vivo. Of the 19 compounds compared using this method, many had no impact on biofilm formation under these conditions. Indeed, only one proved effective at limiting biofilm formation without also inhibiting growth.
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Affiliation(s)
- Mara J. Campbell
- 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
| | - Horace J. Spencer
- Department of Biostatistics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Bina Jayana
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Hana Hester
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Gyan S. Sahukhal
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Mohamed O. Elasri
- 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
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11
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Jiang JH, Cameron DR, Nethercott C, Aires-de-Sousa M, Peleg AY. Virulence attributes of successful methicillin-resistant Staphylococcus aureus lineages. Clin Microbiol Rev 2023; 36:e0014822. [PMID: 37982596 PMCID: PMC10732075 DOI: 10.1128/cmr.00148-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of severe and often fatal infections. MRSA epidemics have occurred in waves, whereby a previously successful lineage has been replaced by a more fit and better adapted lineage. Selection pressures in both hospital and community settings are not uniform across the globe, which has resulted in geographically distinct epidemiology. This review focuses on the mechanisms that trigger the establishment and maintenance of current, dominant MRSA lineages across the globe. While the important role of antibiotic resistance will be mentioned throughout, factors which influence the capacity of S. aureus to colonize and cause disease within a host will be the primary focus of this review. We show that while MRSA possesses a diverse arsenal of toxins including alpha-toxin, the success of a lineage involves more than just producing toxins that damage the host. Success is often attributed to the acquisition or loss of genetic elements involved in colonization and niche adaptation such as the arginine catabolic mobile element, as well as the activity of regulatory systems, and shift metabolism accordingly (e.g., the accessory genome regulator, agr). Understanding exactly how specific MRSA clones cause prolonged epidemics may reveal targets for therapies, whereby both core (e.g., the alpha toxin) and acquired virulence factors (e.g., the Panton-Valentine leukocidin) may be nullified using anti-virulence strategies.
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Affiliation(s)
- Jhih-Hang Jiang
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - David R Cameron
- Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Cara Nethercott
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Marta Aires-de-Sousa
- Laboratory of Molecular Genetics, Institutode Tecnologia Químicae Biológica António Xavier (ITQB-NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
- Escola Superior de Saúde da Cruz Vermelha Portuguesa-Lisboa (ESSCVP-Lisboa), Lisbon, Portugal
| | - Anton Y Peleg
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Centre to Impact Antimicrobial Resistance, Monash University, Clayton, Melbourne, Victoria, Australia
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12
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Qin J, Yu L, Peng F, Ye X, Li G, Sun C, Cheng F, Peng C, Xie X. Tannin extracted from Penthorum chinense Pursh, a potential drug with antimicrobial and antibiofilm effects against methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. Front Microbiol 2023; 14:1134207. [PMID: 37465024 PMCID: PMC10351983 DOI: 10.3389/fmicb.2023.1134207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 06/13/2023] [Indexed: 07/20/2023] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen. Due to the widespread use and abuse of antibiotics, various drug-resistant strains of S. aureus have emerged, with methicillin-resistant Staphylococcus aureus (MRSA) being the most prevalent. Bacterial biofilm is a significant contributor to bacterial infection and drug resistance. Consequently, bacterial biofilm formation has emerged as a therapeutic strategy. In this study, the chemical constituents, antimicrobial and antibiofilm properties of tannins isolated from Penthorum chinense Pursh (TPCP) were investigated. In vitro, TPCP exhibited antimicrobial properties. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) for methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA were 156.25 and 312.5 μg/mL, and 312.5 and 625 μg/mL, respectively. According to the growth curves, TPCP significantly inhibited the growth of MSSA and MRSA. The results of the crystal violet biofilm assay in conjunction with confocal laser scanning and scanning electron microscopy demonstrated that TPCP destroyed preformed MSSA and MRSA biofilms. TPCP significantly decreased the secretion of exopolysaccharides and extracellular DNA. Subsequently, the mechanism was investigated using RT-PCR. Examining the expression of icaA, cidA, sigB, agrA, and sarA genes in MRSA, we discovered that TPCP inhibited biofilm formation by affecting the quorum-sensing system in bacteria. Our study demonstrates that TPCP exerts antibacterial effects by disrupting the formation of bacterial biofilms, suggesting that TPCP has clinical potential as a novel antibacterial agent for the prevention and treatment of MSSA and MRSA infections.
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Affiliation(s)
- Junyuan Qin
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Lei Yu
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Fu Peng
- Department of Pharmacology, Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, China
| | - Xin Ye
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Gangmin Li
- Department of Pharmacy, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, China
| | - Chen Sun
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Fang Cheng
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Cheng Peng
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiaofang Xie
- State Key Laboratory of Southwestern Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
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13
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Martínez A, Stashenko EE, Sáez RT, Zafra G, Ortiz C. Effect of Essential Oil from Lippia origanoides on the Transcriptional Expression of Genes Related to Quorum Sensing, Biofilm Formation, and Virulence of Escherichia coli and Staphylococcus aureus. Antibiotics (Basel) 2023; 12:antibiotics12050845. [PMID: 37237748 DOI: 10.3390/antibiotics12050845] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/25/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Microbial infections resistant to conventional antibiotics constitute one of the most important causes of mortality in the world. In some bacterial species, such as Escherichia coli and Staphylococcus aureus pathogens, biofilm formation can favor their antimicrobial resistance. These biofilm-forming bacteria produce a compact and protective matrix, allowing their adherence and colonization to different surfaces, and contributing to resistance, recurrence, and chronicity of the infections. Therefore, different therapeutic alternatives have been investigated to interrupt both cellular communication routes and biofilm formation. Among these, essential oils (EO) from Lippia origanoides thymol-carvacrol II chemotype (LOTC II) plants have demonstrated biological activity against different biofilm-forming pathogenic bacteria. In this work, we determined the effect of LOTC II EO on the expression of genes associated with quorum sensing (QS) communication, biofilm formation, and virulence of E. coli ATCC 25922 and S. aureus ATCC 29213. This EO was found to have high efficacy against biofilm formation, decreasing-by negative regulation-the expression of genes involved in motility (fimH), adherence and cellular aggregation (csgD), and exopolysaccharide production (pgaC) in E. coli. In addition, this effect was also determined in S. aureus where the L. origanoides EO diminished the expression of genes involved in QS communication (agrA), production of exopolysaccharides by PIA/PNG (icaA), synthesis of alpha hemolysin (hla), transcriptional regulators of the production of extracellular toxins (RNA III), QS and biofilm formation transcriptional regulators (sarA) and global regulators of biofilm formation (rbf and aur). Positive regulation was observed on the expression of genes encoding inhibitors of biofilm formation (e.g., sdiA and ariR). These findings suggest that LOTCII EO can affect biological pathways associated with QS communication, biofilm formation, and virulence of E. coli and S. aureus at subinhibitory concentrations and could be a promising candidate as a natural antibacterial alternative to conventional antibiotics.
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Affiliation(s)
- Andrés Martínez
- Grupo de Investigación en Bioquímica y Microbiología (GIBIM), Escuela de Microbiología, Facultad de Salud, Universidad Industrial de Santander, Bucaramanga 680002, Colombia
| | - Elena E Stashenko
- Escuela de Química, Centro de Cromatografía y Espectrometría de Masas (CROM-MASS), Universidad Industrial de Santander, Bucaramanga 680002, Colombia
| | - Rodrigo Torres Sáez
- Grupo de Investigación en Bioquímica y Microbiología (GIBIM), Escuela de Microbiología, Facultad de Salud, Universidad Industrial de Santander, Bucaramanga 680002, Colombia
| | - German Zafra
- Grupo de Investigación en Bioquímica y Microbiología (GIBIM), Escuela de Microbiología, Facultad de Salud, Universidad Industrial de Santander, Bucaramanga 680002, Colombia
| | - Claudia Ortiz
- Grupo de Investigación en Bioquímica y Microbiología (GIBIM), Escuela de Microbiología, Facultad de Salud, Universidad Industrial de Santander, Bucaramanga 680002, Colombia
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14
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Li M, Xiao H, Su Y, Cheng D, Jia Y, Li Y, Yin Q, Gao J, Tang Y, Bai Q. Synergistic Inhibitory Effect of Honey and Lactobacillus plantarum on Pathogenic Bacteria and Their Promotion of Healing in Infected Wounds. Pathogens 2023; 12:pathogens12030501. [PMID: 36986423 PMCID: PMC10053434 DOI: 10.3390/pathogens12030501] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/14/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023] Open
Abstract
Prevention and control of infections have become a formidable challenge due to the increasing resistance of pathogens to antibiotics. Probiotics have been discovered to have positive effects on the host, and it is well-known that some Lactobacilli are effective in treating and preventing inflammatory and infectious diseases. In this study, we developed an antibacterial formulation consisting of honey and Lactobacillus plantarum (honey-L. plantarum). The optimal formulation of honey (10%) and L. plantarum (1 × 109 CFU/mL) was used to investigate its antimicrobial effect and mechanism in vitro, and its healing effect on wound healing of whole skin infections in rats. Biofilm crystalline violet staining and fluorescent staining results indicated that the honey-L. plantarum formulation prevented the biofilm formation in Staphylococcus aureus and Pseudomonas aeruginosa and increased the number of dead bacteria in the biofilms. Further mechanism studies revealed that the honey-L. plantarum formulation may inhibit biofilm formation by upregulating biofilm-related genes (icaA, icaR, sigB, sarA, and agrA) and downregulating quorum sensing (QS) associated genes (lasI, lasR, rhlI, rhlR, and pqsR). Furthermore, the honey-L. plantarum formulation decreased the number of bacteria in the infected wounds of rats and accelerated the formation of new connective tissue to promote wound healing. Our study suggests that the honey-L. plantarum formulation provides a promising option for the treatment of pathogenic infections and wound healing.
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Affiliation(s)
- Mei Li
- Department of Health Laboratory Technology, School of Public Health, Chongqing Medical University, Chongqing 401334, China
| | - Hong Xiao
- Department of Health Laboratory Technology, School of Public Health, Chongqing Medical University, Chongqing 401334, China
| | - Yongmei Su
- Chongqing College of Traditional Chinese Medicine, Chongqing 402760, China
| | - Danlin Cheng
- The First Clinical School, Chongqing Medical University, Chongqing 400016, China
| | - Yan Jia
- Department of Health Laboratory Technology, School of Public Health, Chongqing Medical University, Chongqing 401334, China
| | - Yingli Li
- Department of Health Laboratory Technology, School of Public Health, Chongqing Medical University, Chongqing 401334, China
| | - Qi Yin
- Department of Health Laboratory Technology, School of Public Health, Chongqing Medical University, Chongqing 401334, China
| | - Jieying Gao
- Department of Health Laboratory Technology, School of Public Health, Chongqing Medical University, Chongqing 401334, China
| | - Yong Tang
- Chongqing Orthopedics Hospital of Traditional Chinese Medicine, Chongqing 400039, China
| | - Qunhua Bai
- Department of Health Laboratory Technology, School of Public Health, Chongqing Medical University, Chongqing 401334, China
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15
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Caldwell M, Hughes M, Wei F, Ngo C, Pascua R, Pugazhendhi AS, Coathup MJ. Promising applications of D-amino acids in periprosthetic joint infection. Bone Res 2023; 11:14. [PMID: 36894568 PMCID: PMC9998894 DOI: 10.1038/s41413-023-00254-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 02/02/2023] [Accepted: 02/10/2023] [Indexed: 03/11/2023] Open
Abstract
Due to the rise in our aging population, a disproportionate demand for total joint arthroplasty (TJA) in the elderly is forecast. Periprosthetic joint infection (PJI) represents one of the most challenging complications that can occur following TJA, and as the number of primary and revision TJAs continues to rise, an increasing PJI burden is projected. Despite advances in operating room sterility, antiseptic protocols, and surgical techniques, approaches to prevent and treat PJI remain difficult, primarily due to the formation of microbial biofilms. This difficulty motivates researchers to continue searching for an effective antimicrobial strategy. The dextrorotatory-isoforms of amino acids (D-AAs) are essential components of peptidoglycan within the bacterial cell wall, providing strength and structural integrity in a diverse range of species. Among many tasks, D-AAs regulate cell morphology, spore germination, and bacterial survival, evasion, subversion, and adhesion in the host immune system. When administered exogenously, accumulating data have demonstrated that D-AAs play a pivotal role against bacterial adhesion to abiotic surfaces and subsequent biofilm formation; furthermore, D-AAs have substantial efficacy in promoting biofilm disassembly. This presents D-AAs as promising and novel targets for future therapeutic approaches. Despite their emerging antibacterial efficacy, their role in disrupting PJI biofilm formation, the disassembly of established TJA biofilm, and the host bone tissue response remains largely unexplored. This review aims to examine the role of D-AAs in the context of TJAs. Data to date suggest that D-AA bioengineering may serve as a promising future strategy in the prevention and treatment of PJI.
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Affiliation(s)
- Matthew Caldwell
- Biionix Cluster & College of Medicine, University of Central Florida, 6900 Lake Nona Blvd, Orlando, FL, 32827, USA
| | - Megan Hughes
- School of Biosciences, Cardiff University, CF10 3AT, Wales, UK
| | - Fei Wei
- Biionix Cluster & College of Medicine, University of Central Florida, 6900 Lake Nona Blvd, Orlando, FL, 32827, USA
| | - Christopher Ngo
- Biionix Cluster & College of Medicine, University of Central Florida, 6900 Lake Nona Blvd, Orlando, FL, 32827, USA
| | - Raven Pascua
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, 6900 Lake Nona Blvd, Orlando, FL, 32827, USA
| | - Abinaya Sindu Pugazhendhi
- Biionix Cluster & College of Medicine, University of Central Florida, 6900 Lake Nona Blvd, Orlando, FL, 32827, USA
| | - Melanie J Coathup
- Biionix Cluster & College of Medicine, University of Central Florida, 6900 Lake Nona Blvd, Orlando, FL, 32827, USA.
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16
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Milly TA, Tal-Gan Y. Targeting Peptide-Based Quorum Sensing Systems for the Treatment of Gram-Positive Bacterial Infections. Pept Sci (Hoboken) 2023; 115:e24298. [PMID: 37397504 PMCID: PMC10312355 DOI: 10.1002/pep2.24298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 10/27/2022] [Indexed: 08/27/2023]
Abstract
Bacteria utilize a cell density-dependent communication system called quorum sensing (QS) to coordinate group behaviors. In Gram-positive bacteria, QS involves the production of and response to auto-inducing peptide (AIP) signaling molecules to modulate group phenotypes, including pathogenicity. As such, this bacterial communication system has been identified as a potential therapeutic target against bacterial infections. More specifically, developing synthetic modulators derived from the native peptide signal paves a new way to selectively block the pathogenic behaviors associated with this signaling system. Moreover, rational design and development of potent synthetic peptide modulators allows in depth understanding of the molecular mechanisms that drive QS circuits in diverse bacterial species. Overall, studies aimed at understanding the role of QS in microbial social behavior could result in the accumulation of significant knowledge of microbial interactions, and consequently lead to the development of alternative therapeutic agents to treat bacterial infectivity. In this review, we discuss recent advances in the development of peptide-based modulators to target QS systems in Gram-positive pathogens, with a focus on evaluating the therapeutic potential associated with these bacterial signaling pathways.
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Affiliation(s)
- Tahmina A. Milly
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada, 89557, United States
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada, 89557, United States
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17
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Razooqi Hussein A, Zamel Khalaf Z. Antibacterial activity of klebocin against methicillin resistance Staphylococcus aureus. Biomedicine (Taipei) 2022. [DOI: 10.51248/.v42i5.1968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Introduction and Aim: Bacteriocins are antimicrobial peptides that have bactericidal and/or bacteriostatic activity against other bacteria. The aim of this study was to assess the antibacterial efficiency of Klebocin a K. pneumoniae bacteriocin, against biofilm formation by clinical isolates of methicillin resistant Staphylococcus aureus MRSA.
Materials and Methods: S. aureus isolated from clinical samples was identified according to vitek 2 system Antibiotic susceptibility test was performed according to disc diffusion method. Vitek 2 compact system was also used to detect MRSA strains. Agar well diffusion method was used to evaluate the antibacterial activity of klebocin from K. pneumoniae towards 11 strains of S. aureus by the microtiter plate method throughout the initial and final steps of biofilm development.
Results: Our finding shown that crude extract of klebocin was active against all the tested pre-formed biofilm of S.aureus isolates and the percentage of inhibition ranging from 78.9-88.5%. Also the results of the current study demonstrated that all matured bacterial biofilm was inhibited in at a percentage ranging from 41.2% - 91.2%.
Conclusion: This finding proved that klebocin had antibacterial activity against planktonic cells of S.aureus in addition to antibiofilm activity against premature and mature biofilm of MRSA. Also klebocin had broad spectrum activity effecting Gram +ve bacteria and its biofilm production.
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18
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Long L, Sulaiman JE, Xiao Y, Cheng A, Wang R, Malit JJ, Wong WC, Liu W, Li YX, Chen F, Lam H, Qian PY. Mode of action of elasnin as biofilm formation eradicator of methicillin-resistant Staphylococcus aureus. Front Microbiol 2022; 13:967845. [PMID: 36003935 PMCID: PMC9393526 DOI: 10.3389/fmicb.2022.967845] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
Biofilm is made up of microbes and their extracellular matrix, making microorganisms highly tolerant, resistant, and resilient to a wide range of antimicrobials. Biofilm treatment with conventional antimicrobial agents can accelerate the evolution and spread of resistance due to the reduced efficacy and increased gene transfer and differentiation within biofilms. Therefore, effective biofilm-targeting compounds are currently highly sought after. In the present study, we identified elasnin as a potent biofilm-targeting compound against methicillin-resistant Staphylococcus aureus (MRSA). Elasnin effectively inhibited biofilm formation and especially eradicated the pre-formed biofilms of MRSA with low cytotoxicity and low risk of resistance development and retains its activity in a chronic wound biofilms model. A comprehensive mechanistic study using multi-omics and confocal and scanning electron microscopy revealed that elasnin induced the biofilm matrix destruction in a time-dependent manner and interfered with the cell division during the exponential phase, primarily by repressing the expression of virulence factors. Cells released from the elasnin-treated biofilms exhibited a defective appearance and became more sensitive to beta-lactam antibiotic penicillin G. Through gene overexpression and deletion assay, we discovered the key role of sarZ during elasnin-induced biofilm eradication. Overall, the present study identified elasnin as a potent biofilm eradicator against MRSA that harbors potential to be developed for biofilm removal and chronic wound treatment, and provided new insights into the molecular targets for biofilm eradication in MRSA.
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Affiliation(s)
- Lexin Long
- Department of Ocean Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
- SZU-HKUST Joint PhD Program in Marine Environmental Science, Shenzhen University, Shenzhen, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Jordy Evan Sulaiman
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China
| | - Yao Xiao
- Department of Ocean Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Aifang Cheng
- Department of Ocean Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Ruojun Wang
- Department of Ocean Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Jessie James Malit
- Department of Ocean Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Wai Chuen Wong
- Department of Ocean Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Wenchao Liu
- Department of Ocean Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Yong-Xin Li
- Department of Chemistry, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- The Swire Institute of Marine Science and Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Feng Chen
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Henry Lam
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China
- Henry Lam,
| | - Pei-Yuan Qian
- Department of Ocean Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- *Correspondence: Pei-Yuan Qian,
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19
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Turner AB, Gerner E, Firdaus R, Echeverz M, Werthén M, Thomsen P, Almqvist S, Trobos M. Role of sodium salicylate in Staphylococcus aureus quorum sensing, virulence, biofilm formation and antimicrobial susceptibility. Front Microbiol 2022; 13:931839. [PMID: 35992652 PMCID: PMC9384861 DOI: 10.3389/fmicb.2022.931839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/06/2022] [Indexed: 01/01/2023] Open
Abstract
The widespread threat of antibiotic resistance requires new treatment options. Disrupting bacterial communication, quorum sensing (QS), has the potential to reduce pathogenesis by decreasing bacterial virulence. The aim of this study was to investigate the influence of sodium salicylate (NaSa) on Staphylococcus aureus QS, virulence production and biofilm formation. In S. aureus ATCC 25923 (agr III), with or without serum, NaSa (10 mM) downregulated the agr QS system and decreased the secretion levels of alpha-hemolysin, staphopain A and delta-hemolysin. Inhibition of agr expression caused a downregulation of delta-hemolysin, decreasing biofilm dispersal and increasing biofilm formation on polystyrene and titanium under static conditions. In contrast, NaSa did not increase biofilm biomass under flow but caused one log10 reduction in biofilm viability on polystyrene pegs, resulting in biofilms being twice as susceptible to rifampicin. A concentration-dependent effect of NaSa was further observed, where high concentrations (10 mM) decreased agr expression, while low concentrations (≤0.1 mM) increased agr expression. In S. aureus 8325-4 (agr I), a high concentration of NaSa (10 mM) decreased hla expression, and a low concentration of NaSa (≤1 mM) increased rnaIII and hla expression. The activity of NaSa on biofilm formation was dependent on agr type and material surface. Eight clinical strains isolated from prosthetic joint infection (PJI) or wound infection belonging to each of the four agr types were evaluated. The four PJI S. aureus strains did not change their biofilm phenotype with NaSa on the clinically relevant titanium surface. Half of the wound strains (agr III and IV) did not change the biofilm phenotype in the 3D collagen wound model. In addition, compared to the control, ATCC 25923 biofilms formed with 10 mM NaSa in the collagen model were more susceptible to silver. It is concluded that NaSa can inhibit QS in S. aureus, decreasing the levels of toxin production with certain modulation of biofilm formation. The effect on biofilm formation was dependent on the strain and material surface. It is suggested that the observed NaSa inhibition of bacterial communication is a potential alternative or adjuvant to traditional antibiotics.
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Affiliation(s)
- Adam Benedict Turner
- Department of Biomaterials, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
- Center for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Erik Gerner
- Department of Biomaterials, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
- Center for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
- Mölnlycke Health Care AB, Gothenburg, Sweden
| | - Rininta Firdaus
- Department of Biomaterials, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
- Center for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Maite Echeverz
- Microbial Pathogenesis Research Unit, Public University of Navarre, Pamplona, Spain
| | - Maria Werthén
- Department of Biomaterials, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
- Center for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Peter Thomsen
- Department of Biomaterials, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
| | | | - Margarita Trobos
- Department of Biomaterials, University of Gothenburg, The Sahlgrenska Academy, Gothenburg, Sweden
- Center for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
- *Correspondence: Margarita Trobos,
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20
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An Overview of Biofilm Formation-Combating Strategies and Mechanisms of Action of Antibiofilm Agents. LIFE (BASEL, SWITZERLAND) 2022; 12:life12081110. [PMID: 35892912 PMCID: PMC9394423 DOI: 10.3390/life12081110] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 11/19/2022]
Abstract
Biofilm formation on surfaces via microbial colonization causes infections and has become a major health issue globally. The biofilm lifestyle provides resistance to environmental stresses and antimicrobial therapies. Biofilms can cause several chronic conditions, and effective treatment has become a challenge due to increased antimicrobial resistance. Antibiotics available for treating biofilm-associated infections are generally not very effective and require high doses that may cause toxicity in the host. Therefore, it is essential to study and develop efficient anti-biofilm strategies that can significantly reduce the rate of biofilm-associated healthcare problems. In this context, some effective combating strategies with potential anti-biofilm agents, including plant extracts, peptides, enzymes, lantibiotics, chelating agents, biosurfactants, polysaccharides, organic, inorganic, and metal nanoparticles, etc., have been reviewed to overcome biofilm-associated healthcare problems. From their extensive literature survey, it can be concluded that these molecules with considerable structural alterations might be applied to the treatment of biofilm-associated infections, by evaluating their significant delivery to the target site of the host. To design effective anti-biofilm molecules, it must be assured that the minimum inhibitory concentrations of these anti-biofilm compounds can eradicate biofilm-associated infections without causing toxic effects at a significant rate.
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21
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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: 6] [Impact Index Per Article: 2.0] [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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22
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Colonization and Infection of Indwelling Medical Devices by Staphylococcus aureus with an Emphasis on Orthopedic Implants. Int J Mol Sci 2022; 23:ijms23115958. [PMID: 35682632 PMCID: PMC9180976 DOI: 10.3390/ijms23115958] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 02/08/2023] Open
Abstract
The use of indwelling medical devices has constantly increased in recent years and has revolutionized the quality of life of patients affected by different diseases. However, despite the improvement of hygiene conditions in hospitals, implant-associated infections remain a common and serious complication in prosthetic surgery, mainly in the orthopedic field, where infection often leads to implant failure. Staphylococcus aureus is the most common cause of biomaterial-centered infection. Upon binding to the medical devices, these bacteria proliferate and develop dense communities encased in a protective matrix called biofilm. Biofilm formation has been proposed as occurring in several stages-(1) attachment; (2) proliferation; (3) dispersal-and involves a variety of host and staphylococcal proteinaceous and non-proteinaceous factors. Moreover, biofilm formation is strictly regulated by several control systems. Biofilms enable staphylococci to avoid antimicrobial activity and host immune response and are a source of persistent bacteremia as well as of localized tissue destruction. While considerable information is available on staphylococcal biofilm formation on medical implants and important results have been achieved on the treatment of biofilms, preclinical and clinical applications need to be further investigated. Thus, the purpose of this review is to gather current studies about the mechanism of infection of indwelling medical devices by S. aureus with a special focus on the biochemical factors involved in biofilm formation and regulation. We also provide a summary of the current therapeutic strategies to combat biomaterial-associated infections and highlight the need to further explore biofilm physiology and conduct research for innovative anti-biofilm approaches.
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23
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Fasiku VO, Omolo CA, Kiruri LW, Devnarain N, Faya M, Mocktar C, Govender T. A hyaluronic acid-based nanogel for the co-delivery of nitric oxide (NO) and a novel antimicrobial peptide (AMP) against bacterial biofilms. Int J Biol Macromol 2022; 206:381-397. [PMID: 35202637 DOI: 10.1016/j.ijbiomac.2022.02.099] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/01/2022] [Accepted: 02/16/2022] [Indexed: 02/06/2023]
Abstract
Biofilms are a global health concern because they are associated with chronic and recurrent infections as well as resistance to conventional antibiotics. The aim of this study was to prepare a nanogel for the co-delivery of NO and AMPs against bacteria and biofilms. The NO-releasing nanogel was prepared by crosslinking HA solution with divinyl sulfone and extensively characterized. The nanogel was found to be biocompatible, injectable and NO release from the gel was sustained over a period of 24 h. In vitro antibacterial studies showed that the NO-AMP-loaded nanogel exhibited a broad spectrum antibacterial/antibiofilm activity. The NO-releasing nanogel had a greater antibacterial effect when compared to NO alone with MIC values of 1.56, 0.78 and 0.39 μg/ml against Escherichia coli, Methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa bacteria respectively. The antibiofilm results showed there was a 12.5 and 24-folds reduction in biofilms of MRSA, and P. aeruginosa respectively for catheters exposed to nanogel loaded with AMP/NO when compared to only NO, while a 7 and 9.4-folds reduction in biofilms of MRSA, and P. aeruginosa respectively was displayed by the nanogel loaded with only NO compared to only NO. The AMP/NO-releasing nanogel showed the potential to combat both biofilms and bacterial infections.
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Affiliation(s)
- Victoria O Fasiku
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, South Africa
| | - Calvin A Omolo
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, South Africa; United States International University-Africa, School of Pharmacy and Health Sciences, Department of Pharmaceutics, P. O. Box 14634-00800, Nairobi, Kenya
| | - Lucy W Kiruri
- Department of Chemistry, Kenyatta University, P. O. Box 43844 - 00100, Nairobi, Kenya
| | - Nikita Devnarain
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, South Africa
| | - Mbuso Faya
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, South Africa
| | - Chunderika Mocktar
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, South Africa
| | - Thirumala Govender
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, South Africa.
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24
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Kaur H, Kaur A, Soni SK, Rishi P. Microbially-derived cocktail of carbohydrases as an anti-biofouling agents: a 'green approach'. BIOFOULING 2022; 38:455-481. [PMID: 35673761 DOI: 10.1080/08927014.2022.2085566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 05/12/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
Enzymes, also known as biocatalysts, display vital properties like high substrate specificity, an eco-friendly nature, low energy inputs, and cost-effectiveness. Among their numerous known applications, enzymes that can target biofilms or their components are increasingly being investigated for their anti-biofouling action, particularly in healthcare, food manufacturing units and environmental applications. Enzymes can target biofilms at different levels like during the attachment of microorganisms, formation of exopolymeric substances (EPS), and their disruption thereafter. In this regard, a consortium of carbohydrases that can target heterogeneous polysaccharides present in the EPS matrix may provide an effective alternative to conventional chemical anti-biofouling methods. Further, for complete annihilation of biofilms, enzymes can be used alone or in conjunction with other antimicrobial agents. Enzymes hold the promise to replace the conventional methods with greener, more economical, and more efficient alternatives. The present article explores the potential and future perspectives of using carbohydrases as effective anti-biofilm agents.
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Affiliation(s)
- Harmanpreet Kaur
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Arashdeep Kaur
- Department of Microbiology, Panjab University, Chandigarh, India
| | | | - Praveen Rishi
- Department of Microbiology, Panjab University, Chandigarh, India
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25
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Zhang L, Yang W, Chu Y, Wen B, Cheng Y, Mahmood T, Bao M, Ge F, Li L, Yi J, Du C, Lu C, Tan Y. The Inhibition Effect of Linezolid With Reyanning Mixture on MRSA and its Biofilm is More Significant than That of Linezolid Alone. Front Pharmacol 2022; 12:766309. [PMID: 35046807 PMCID: PMC8762264 DOI: 10.3389/fphar.2021.766309] [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: 08/28/2021] [Accepted: 12/01/2021] [Indexed: 12/02/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a superbacterium, and when it forms biofilms, it is difficult to treat even with the first-line of antibiotic linezolid (LNZ). Reyanning mixture (RYN), a compound-based Chinese medicine formula, has been found to have inhibitory effects on biofilms. This study aims to explore the synergistic inhibitory effect and corresponding mechanisms of their (LNZ&RYN) combination on the planktonic as well as biofilm cells of MRSA. Broth microdilution and chessboard methods were employed for the determination of minimum inhibitory concentrations (MICs) and synergistic concentration of LNZ&RYN, respectively. The effect of the combined medication on biofilm and mature biofilm of MRSA were observed by biofilm morphology and permeability experiments, respectively. To unveil the molecular mechanism of action of the synergistic combination of LNZ and RYN, RT-PCR based biofilm-related gene expression analysis and ultra-high pressure liquid chromatography-time-of-flight mass spectrometry based endogenous metabonomic analysis were deployed. The results indicated that 1/16RYN as the best combined dose reduced LNZ (4 μg/ml) to 2 μg/ml. The combined treatment inhibited living MRSA before and after biofilm formation, removed the residual structure of dead bacteria in MRSA biofilms and affected the shape and size of bacteria, resulting in the improvement of biofilm permeability. The mechanism was that biofilm-related genes such as agrC, atlA, and sarA, as well as amino acid uptake associated with the metabolism of 3-dehydrocarnitine, kynurenine, L-leucine, L-lysine and sebacic acid were inhibited. This study provides evidence for the treatment of MRSA and its biofilms with LNZ combined with RYN.
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Affiliation(s)
- Lulu Zhang
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China.,Key Laboratory for Research on Active Ingredients in Natural Medicine of Jiangxi Province, Yichun University, Yichun, China
| | - Weifeng Yang
- Experimental Research Center, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yajun Chu
- Tsing Hua De Ren Xi an Happiness Pharmaceutical Co., Ltd., Xi'an, China
| | - Bo Wen
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yungchi Cheng
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT, United States
| | - Tariq Mahmood
- Department of Plant Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Mei Bao
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China.,Key Laboratory for Research on Active Ingredients in Natural Medicine of Jiangxi Province, Yichun University, Yichun, China
| | - Feng Ge
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China
| | - Li Li
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jianfeng Yi
- Key Laboratory for Research on Active Ingredients in Natural Medicine of Jiangxi Province, Yichun University, Yichun, China
| | - Chengqiang Du
- Tsing Hua De Ren Xi an Happiness Pharmaceutical Co., Ltd., Xi'an, China
| | - Cheng Lu
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yong Tan
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China
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26
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Shimamura Y, Yui T, Horiike H, Masuda S. Toxicity of combined exposure to acrylamide and Staphylococcus aureus. Toxicol Rep 2022; 9:876-882. [DOI: 10.1016/j.toxrep.2022.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 04/17/2022] [Accepted: 04/18/2022] [Indexed: 11/26/2022] Open
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27
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Cheung GYC, Bae JS, Otto M. Pathogenicity and virulence of Staphylococcus aureus. Virulence 2021; 12:547-569. [PMID: 33522395 PMCID: PMC7872022 DOI: 10.1080/21505594.2021.1878688] [Citation(s) in RCA: 633] [Impact Index Per Article: 158.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 12/15/2022] Open
Abstract
Staphylococcus aureus is one of the most frequent worldwide causes of morbidity and mortality due to an infectious agent. This pathogen can cause a wide variety of diseases, ranging from moderately severe skin infections to fatal pneumonia and sepsis. Treatment of S. aureus infections is complicated by antibiotic resistance and a working vaccine is not available. There has been ongoing and increasing interest in the extraordinarily high number of toxins and other virulence determinants that S. aureus produces and how they impact disease. In this review, we will give an overview of how S. aureus initiates and maintains infection and discuss the main determinants involved. A more in-depth understanding of the function and contribution of S. aureus virulence determinants to S. aureus infection will enable us to develop anti-virulence strategies to counteract the lack of an anti-S. aureus vaccine and the ever-increasing shortage of working antibiotics against this important pathogen.
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Affiliation(s)
- Gordon Y. C. Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, Maryland, USA
| | - Justin S. Bae
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, Maryland, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, Maryland, USA
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28
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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: 2.0] [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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29
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Pant N, Eisen DP. Non-Antimicrobial Adjuvant Strategies to Tackle Biofilm-Related Staphylococcus aureus Prosthetic Joint Infections. Antibiotics (Basel) 2021; 10:antibiotics10091060. [PMID: 34572641 PMCID: PMC8465242 DOI: 10.3390/antibiotics10091060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 08/27/2021] [Accepted: 08/28/2021] [Indexed: 12/15/2022] Open
Abstract
Staphylococcus aureus frequently causes community- and hospital-acquired infections. S. aureus attachment followed by biofilm formation on tissues and medical devices plays a significant role in the establishment of chronic infections. Staphylococcal biofilms encase bacteria in a matrix and protect the cells from antimicrobials and the immune system, resulting in infections that are highly resistant to treatment. The biology of biofilms is complex and varies between organisms. In this review, we focus our discussion on S. aureus biofilms and describe the stages of their formation. We particularly emphasize genetic and biochemical processes that may be vulnerable to novel treatment approaches. Against this background, we discuss treatment strategies that have been successful in animal models of S. aureus biofilm-related infection and consider their possible use for the prevention and eradication of biofilm-related S. aureus prosthetic joint infection.
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30
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Diepoltová A, Konečná K, Janďourek O, Nachtigal P. Study of the impact of cultivation conditions and peg surface modification on the in vitro biofilm formation of Staphylococcus aureus and Staphylococcus epidermidis in a system analogous to the Calgary biofilm device. J Med Microbiol 2021; 70. [PMID: 34048334 DOI: 10.1099/jmm.0.001371] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Introduction. Staphylococcus aureus (SA) and Staphylococcus epidermidis (SE) are the most common pathogens from the genus Staphylococcus causing biofilm-associated infections. Generally, biofilm-associated infections represent a clinical challenge. Bacteria in biofilms are difficult to eradicate due to their resistance and serve as a reservoir for recurring persistent infections.Gap Statement. A variety of protocols for in vitro drug activity testing against staphylococcal biofilms have been introduced. However, there are often fundamental differences. All these differences in methodical approaches can then be reflected in the form of discrepancies between results.Aim. In this study, we aimed to develop optimal conditions for staphylococcal biofilm formation on pegs. The impact of peg surface modification was also studied.Methodology. The impact of tryptic soy broth alone or supplemented with foetal bovine serum (FBS) or human plasma (HP), together with the impact of the inoculum density of bacterial suspensions and the shaking versus the static mode of cultivation, on total biofilm biomass production in SA and SE reference strains was studied. The surface of pegs was modified with FBS, HP, or poly-l-lysine (PLL). The impact on total biofilm biomass was evaluated using the crystal violet staining method and statistical data analysis.Results. Tryptic soy broth supplemented with HP together with the shaking mode led to crucial potentiation of biofilm formation on pegs in SA strains. The SE strain did not produce biofilm biomass under the same conditions on pegs. Preconditioning of peg surfaces with FBS and HP led to a statistically significant increase in biofilm biomass formation in the SE strain.Conclusion. Optimal cultivation conditions for robust staphylococcal biofilm formation in vitro might differ among different bacterial strains and methodical approaches. The shaking mode and supplementation of cultivation medium with HP was beneficial for biofilm formation on pegs for SA (ATCC 29213) and methicillin-resistant SA (ATCC 43300). Peg conditioning with HP and PLL had no impact on biofilm formation in either of these strains. Peg coating with FBS showed an adverse effect on the biofilm formation of these strains. By contrast, there was a statistically significant increase in biofilm biomass production on pegs coated with FBS and HP for SE (ATCC 35983).
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Affiliation(s)
- Adéla Diepoltová
- Charles University, Faculty of Pharmacy in Hradec Králové, Teaching and Research Centre, Czech Republic
| | - Klára Konečná
- Charles University, Faculty of Pharmacy in Hradec Králové, Teaching and Research Centre, Czech Republic
| | - Ondřej Janďourek
- Charles University, Faculty of Pharmacy in Hradec Králové, Teaching and Research Centre, Czech Republic
| | - Petr Nachtigal
- Charles University, Faculty of Pharmacy in Hradec Králové, Teaching and Research Centre, Czech Republic
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31
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Shi C, Ye J, Xu R, Jin W, Xu S, Teng F, Lin N. Effect of the vancomycin minimum inhibitory concentration on clinical outcomes in patients with methicillin-susceptible Staphylococcus aureus bacteraemia: a systematic review and meta-analysis. BMJ Open 2021; 11:e040675. [PMID: 33452189 PMCID: PMC7813418 DOI: 10.1136/bmjopen-2020-040675] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVE The use of the vancomycin minimum inhibitory concentration (MIC) as a prognostic predictor in patients with methicillin-susceptible Staphylococcus aureus (MSSA) has been debated in the last decade. We performed a systematic review and meta-analysis to investigate whether an elevated vancomycin MIC is associated with a worse prognosis for patients with MSSA bacteraemia. DESIGN Systematic review and meta-analysis. DATA SOURCES PubMed, Embase and the Cochrane Library were searched from inception to December 2019. ELIGIBILITY CRITERIA Randomised controlled trials or observational studies were considered eligible if they provided clinical outcomes of patients with MSSA bacteraemia, stratified by vancomycin MIC. DATA SYNTHESIS Primary outcome was mortality. Secondary outcomes included septic thrombophlebitis, persistent bacteraemia and complicated bacteraemia. Pooled ORs and 95% CIs were calculated. Subgroup analyses included the susceptibility testing method. RESULTS Fifteen observational studies were included. Bacteraemia due to MSSA isolates with high vancomycin MICs was associated with higher mortality than isolates with low MICs (OR 1.44; 95% CI 1.12 to 1.84; I2=40.3%). Additionally, significantly greater septic thrombophlebitis (OR 3.16; 95% CI 1.11 to 9.00; I2=58.6%) and a trend towards more persistent bacteraemia (OR 1.79; 95% CI 0.97 to 3.31; I2=0%) were observed in patients with high vancomycin MICs than in patients with low MICs. Differences in complicated bacteraemia were not significant. Similar findings were obtained in subgroup analyses using Etest. However, significant differences in outcomes were not observed between the high and low vancomycin MICs detected using broth microdilution. CONCLUSION The available data suggest an association between elevated vancomycin MICs detected using Etest and adverse clinical outcomes for patients with MSSA bacteraemia. Future studies should validate these findings and explore the potential mechanisms. PROSPERO REGISTRATION NUMBER CRD42018090547.
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Affiliation(s)
- Changcheng Shi
- Department of Clinical Pharmacy, Key Laboratory of Clinical Cancer Pharmacology and Toxicology Research of Zhejiang Province, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jian Ye
- Department of Respiratory Medicine, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Renjie Xu
- Department of Clinical Pharmacy, Shaoxing Women and Children's Hospital, Shaoxing, Zhejiang, China
| | - Weizhong Jin
- Department of Respiratory Medicine, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Shuang Xu
- Translational Medicine Research Center, Hangzhou First People's Hospital, Nanjing Medical University, Hangzhou, Zhejiang, China
| | - Fei Teng
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Nengming Lin
- Department of Clinical Pharmacology, Translational Medicine Research Center, Key Laboratory of Clinical Cancer Pharmacology and Toxicology Research of Zhejiang Province, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
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32
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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: 3.0] [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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Antibiofilm effects of N,O-acetals derived from 2-amino-1,4-naphthoquinone are associated with downregulation of important global virulence regulators in methicillin-resistant Staphylococcus aureus. Sci Rep 2020; 10:19631. [PMID: 33184312 PMCID: PMC7661526 DOI: 10.1038/s41598-020-76372-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/27/2020] [Indexed: 02/06/2023] Open
Abstract
Despite the existing antibiotics, antimicrobial resistance is a major challenge. Consequently, the development of new drugs remains in great demand. Quinones is part of a broad group of molecules that present antibacterial activity besides other biological properties. The main purpose of this study was to evaluate the antibiofilm activities of synthetic N,O-acetals derived from 2-amino-1,4-naphthoquinone [7a: 2-(methoxymethyl)-amino-1,4-naphthoquinone; 7b: 2-(ethoxymethyl)-amino-1,4-naphthoquinone; and 7c: 2-(propynyloxymethyl)-amino-1,4-naphthoquinone] against methicillin-resistant Staphylococcus aureus (MRSA). The derivatives 7b and 7c, specially 7b, caused strong impact on biofilm accumulation. This inhibition was linked to decreased expression of the genes fnbA, spa, hla and psmα3. More importantly, this downregulation was paralleled by the modulation of global virulence regulators. The substitution of 2-ethoxymethyl (7b) in comparison with 2-propynyloxymethyl (7c) enhanced sarA-agr inhibition, decreased fnbA transcripts (positively regulated by sarA) and strongly impaired biofilm accumulation. Indeed, 7b triggered intensive autolysis and was able to eliminate vancomycin-persistent cells. Consequently, 7b is a promising molecule displaying not only antimicrobial effects, but also antibiofilm and antipersistence activities. Therefore, 7b is a good candidate for further studies involving the development of novel and more rational antimicrobials able to act in chronic and recalcitrant infections, associated with biofilm formation.
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Salzer A, Keinhörster D, Kästle C, Kästle B, Wolz C. Small Alarmone Synthetases RelP and RelQ of Staphylococcus aureus Are Involved in Biofilm Formation and Maintenance Under Cell Wall Stress Conditions. Front Microbiol 2020; 11:575882. [PMID: 33072039 PMCID: PMC7533549 DOI: 10.3389/fmicb.2020.575882] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/25/2020] [Indexed: 12/15/2022] Open
Abstract
The stringent response is characterized by the synthesis of the alarmone (p)ppGpp. The phenotypic consequences resulting from (p)ppGpp accumulation vary among species, and for several pathogenic bacteria, it has been shown that the activation of the stringent response strongly affects biofilm formation and maintenance. In Staphylococcus aureus, (p)ppGpp can be synthesized by the RelA/SpoT homolog Rel upon amino acid deprivation or by the two small alarmone synthetases RelP and RelQ under cell wall stress. We found that relP and relQ increase biofilm formation under cell wall stress conditions induced by a subinhibitory vancomycin concentration. However, the effect of (p)ppGpp on biofilm formation is independent of the regulators CodY and Agr. Biofilms formed by the strain HG001 or its (p)ppGpp-defective mutants are mainly composed of extracellular DNA and proteins. Furthermore, the induction of the RelPQ-mediated stringent response contributes to biofilm-related antibiotic tolerance. The proposed (p)ppGpp-inhibiting peptide DJK-5 shows bactericidal and biofilm-inhibitory activity. However, a non-(p)ppGpp-producing strain is even more vulnerable to DJK-5. This strongly argues against the assumption that DJK-5 acts via (p)ppGpp inhibition. In summary, RelP and RelQ play a major role in biofilm formation and maintenance under cell wall stress conditions.
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Affiliation(s)
| | | | | | | | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
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35
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Silence as a way of niche adaptation: mecC-MRSA with variations in the accessory gene regulator (agr) functionality express kaleidoscopic phenotypes. Sci Rep 2020; 10:14787. [PMID: 32901059 PMCID: PMC7479134 DOI: 10.1038/s41598-020-71640-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 08/19/2020] [Indexed: 11/09/2022] Open
Abstract
Functionality of the accessory gene regulator (agr) quorum sensing system is an important factor promoting either acute or chronic infections by the notorious opportunistic human and veterinary pathogen Staphylococcus aureus. Spontaneous alterations of the agr system are known to frequently occur in human healthcare-associated S. aureus lineages. However, data on agr integrity and function are sparse regarding other major clonal lineages. Here we report on the agr system functionality and activity level in mecC-carrying methicillin resistant S. aureus (MRSA) of various animal origins (n = 33) obtained in Europe as well as in closely related human isolates (n = 12). Whole genome analysis assigned all isolates to four clonal complexes (CC) with distinct agr types (CC599 agr I, CC49 agr II, CC130 agr III and CC1943 agr IV). Agr functionality was assessed by a combination of phenotypic assays and proteome analysis. In each CC, isolates with varying agr activity levels were detected, including the presence of completely non-functional variants. Genomic comparison of the agr I-IV encoding regions associated these phenotypic differences with variations in the agrA and agrC genes. The genomic changes were detected independently in divergent lineages, suggesting that agr variation might foster viability and adaptation of emerging MRSA lineages to distinct ecological niches.
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Dutta K, Karmakar A, Jana D, Ballav S, Shityakov S, Panda AK, Ghosh C. Benzyl isocyanate isolated from the leaves of Psidium guajava inhibits Staphylococcus aureus biofilm formation. BIOFOULING 2020; 36:1000-1017. [PMID: 33172298 DOI: 10.1080/08927014.2020.1842877] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 09/03/2020] [Accepted: 10/20/2020] [Indexed: 06/11/2023]
Abstract
Benzyl isocyanate (BIC), from methanol extract of Psidium guajava leaves, exhibited substantial anti-biofilm activities against Staphylococcus aureus, the common bacterial pathogen in nosocomial infections. Major components of the extract included eugenol, BIC, phenyl-2-methoxy-4-(1-propenyl)-acetate and 2,5-pyrrolidinedione,1-penta-3-4-dienyl, analyzed by GC-MS and HPLC studies. BIC exhibited substantial anti-biofilm activitiy against S. aureus, established by assaying biofilm formation, biofilm metabolic activity, bacterial adherence to hydrocarbons, exopolysaccharide formation, and optical and scanning electron microscopic studies. BIC significantly downregulated the important biofilm markers of S. aureus, viz., icaAD, sarA and agr, observed by quantitative real time polymerase chain reaction analysis. Molecular docking studies revealed thermodynamically favorable interaction of BIC with IcaA, SarA and Agr, having Gibbs energy values of -8.45, -9.09 and -10.29 kcal mol-1, respectively. BIC after binding to IcaR, the repressor of IcaA, influences its binding to target DNA site (Eshape, -157.27 kcal mol-1). The results are considered to demonstrate anti-biofilm potential of BIC against bacterial infections.
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Affiliation(s)
- Kunal Dutta
- Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India
| | - Amit Karmakar
- Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India
| | - Debarati Jana
- Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India
| | - Saroj Ballav
- Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India
| | - Sergey Shityakov
- Department of Anaesthesia and Critical Care, University of Würzburg, Würzburg, Germany
| | - Amiya Kumar Panda
- Department of Chemistry, Vidyasagar University, Midnapore, West Bengal, India
| | - Chandradipa Ghosh
- Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India
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A comprehensive review of bacterial osteomyelitis with emphasis on Staphylococcus aureus. Microb Pathog 2020; 148:104431. [PMID: 32801004 DOI: 10.1016/j.micpath.2020.104431] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/29/2020] [Accepted: 07/29/2020] [Indexed: 02/04/2023]
Abstract
Osteomyelitis, a significant infection of bone tissue, gives rise to two main groups of infection: acute and chronic. These groups are further categorized in terms of the duration of infection. Usually, children and adults are more susceptible to acute and chronic infections, respectively. The aforementioned groups of osteomyelitis share almost 80% of the corresponding bacterial pathogens. Among all bacteria, Staphylococcus aureus (S. aureus) is a significant pathogen and is associated with a high range of osteomyelitis symptoms. S. aureus has many strategies for interacting with host cells including Small Colony Variant (SCV), biofilm formation, and toxin secretion. In addition, it induces an inflammatory response and causes host cell death by apoptosis and necrosis. However, any possible step to take in this respect is dependent on the conditions and host responses. In the absence of any immune responses and antibiotics, bacteria actively duplicate themselves; however, in the presence of phagocytic cell and harassing conditions, they turn into a SCV, remaining sustainable for a long time. SCV is characterized by notable advantages such as (a) intracellular life that mediates a dam against immune cells and (b) low ATP production that mediates resistance against antibiotics.
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Butrico CE, Cassat JE. Quorum Sensing and Toxin Production in Staphylococcus aureus Osteomyelitis: Pathogenesis and Paradox. Toxins (Basel) 2020; 12:toxins12080516. [PMID: 32806558 PMCID: PMC7471978 DOI: 10.3390/toxins12080516] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/04/2020] [Accepted: 08/10/2020] [Indexed: 01/18/2023] Open
Abstract
Staphylococcus aureus is a Gram-positive pathogen capable of infecting nearly every vertebrate organ. Among these tissues, invasive infection of bone (osteomyelitis) is particularly common and induces high morbidity. Treatment of osteomyelitis is notoriously difficult and often requires debridement of diseased bone in conjunction with prolonged antibiotic treatment to resolve infection. During osteomyelitis, S. aureus forms characteristic multicellular microcolonies in distinct niches within bone. Virulence and metabolic responses within these multicellular microcolonies are coordinated, in part, by quorum sensing via the accessory gene regulator (agr) locus, which allows staphylococcal populations to produce toxins and adapt in response to bacterial density. During osteomyelitis, the Agr system significantly contributes to dysregulation of skeletal homeostasis and disease severity but may also paradoxically inhibit persistence in the host. Moreover, the Agr system is subject to complex crosstalk with other S. aureus regulatory systems, including SaeRS and SrrAB, which can significantly impact the progression of osteomyelitis. The objective of this review is to highlight Agr regulation, its implications on toxin production, factors that affect Agr activation, and the potential paradoxical influences of Agr regulation on disease progression during osteomyelitis.
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Affiliation(s)
- Casey E. Butrico
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
| | - James E. Cassat
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation (VI4), Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Correspondence: ; Tel.: +1-615-936-6494
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39
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Inhibition of multidrug-resistant foodborne Staphylococcus aureus biofilms by a natural terpenoid (+)-nootkatone and related molecular mechanism. Food Control 2020. [DOI: 10.1016/j.foodcont.2020.107154] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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40
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Ramirez AM, Byrum SD, Beenken KE, Washam C, Edmondson RD, Mackintosh SG, Spencer HJ, Tackett AJ, Smeltzer MS. Exploiting Correlations between Protein Abundance and the Functional Status of saeRS and sarA To Identify Virulence Factors of Potential Importance in the Pathogenesis of Staphylococcus aureus Osteomyelitis. ACS Infect Dis 2020; 6:237-249. [PMID: 31722523 PMCID: PMC7294808 DOI: 10.1021/acsinfecdis.9b00291] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We used a murine model of postsurgical osteomyelitis (OM) to evaluate the relative virulence of the Staphylococcus aureus strain LAC and five isogenic variants that differ in the functional status of saeRS and sarA relative to each other. LAC and a variant in which saeRS activity is increased (saeC) were comparably virulent to each other, while ΔsaeRS, ΔsarA, ΔsaeRS/ΔsarA, and saeC/ΔsarA mutants were all attenuated to a comparable degree. Phenotypic comparisons including a mass-based proteomics approach that allowed us to assess the number and abundance of full-length proteins suggested that mutation of saeRS attenuates virulence in our OM model owing primarily to the decreased production of S. aureus virulence factors, while mutation of sarA does so owing to protease-mediated degradation of these same virulence factors. This was confirmed by demonstrating that eliminating protease production restored virulence to a greater extent in a LAC sarA mutant than in the isogenic saeRS mutant. Irrespective of the mechanism involved, mutation of saeRS or sarA was shown to result in reduced accumulation of virulence factors of potential importance. Thus, using our proteomics approach we correlated the abundance of specific proteins with virulence in these six strains and identified 14 proteins that were present in a significantly increased amount (log2 ≥ 5.0) in both virulent strains by comparison to all four attenuated strains. We examined biofilm formation and virulence in our OM model using a LAC mutant unable to produce one of these 14 proteins, specifically staphylocoagulase. The results confirmed that mutation of coa limits biofilm formation and, to a lesser extent, virulence in our OM model, although in both cases the limitation was reduced by comparison to the isogenic sarA mutant.
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Affiliation(s)
- Aura M. Ramirez
- Department of Microbiology
and Immunology, College of Medicine, University
of Arkansas for Medical Sciences, 4301 W. Markham Street, Slot 511, Little Rock, Arkansas 72205, United States
| | - Stephanie D. Byrum
- Department
of Biochemistry and Molecular Biology, University
of Arkansas for Medical Sciences, 4301 W. Markham Street, Slot 516, Little Rock, Arkansas 72205, United States,Arkansas
Children’s Research Institute, 1 Children’s Way, Little Rock, Arkansas 72202, United States
| | - Karen E. Beenken
- Department of Microbiology
and Immunology, College of Medicine, University
of Arkansas for Medical Sciences, 4301 W. Markham Street, Slot 511, Little Rock, Arkansas 72205, United States
| | - Charity Washam
- Department
of Biochemistry and Molecular Biology, University
of Arkansas for Medical Sciences, 4301 W. Markham Street, Slot 516, Little Rock, Arkansas 72205, United States,Arkansas
Children’s Research Institute, 1 Children’s Way, Little Rock, Arkansas 72202, United States
| | - Rick D. Edmondson
- Department
of Biochemistry and Molecular Biology, University
of Arkansas for Medical Sciences, 4301 W. Markham Street, Slot 516, Little Rock, Arkansas 72205, United States
| | - Samuel G. Mackintosh
- Department
of Biochemistry and Molecular Biology, University
of Arkansas for Medical Sciences, 4301 W. Markham Street, Slot 516, Little Rock, Arkansas 72205, United States
| | - Horace J. Spencer
- Department of Biostatistics, University of Arkansas for Medical Sciences, 4301 W. Markham Street, Little Rock, Arkansas 72205, United States
| | - Alan J. Tackett
- Department
of Biochemistry and Molecular Biology, University
of Arkansas for Medical Sciences, 4301 W. Markham Street, Slot 516, Little Rock, Arkansas 72205, United States,Arkansas
Children’s Research Institute, 1 Children’s Way, Little Rock, Arkansas 72202, United States
| | - Mark S. Smeltzer
- Department of Microbiology
and Immunology, College of Medicine, University
of Arkansas for Medical Sciences, 4301 W. Markham Street, Slot 511, Little Rock, Arkansas 72205, United States,Department
of Orthopaedic Surgery, University of Arkansas
for Medical Sciences, 4301 W. Markham Street, Slot 531, Little Rock, Arkansas 72205, United States,Phone: 501-686-7958. E-mail:
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41
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Zheng JX, Tu HP, Sun X, Xu GJ, Chen JW, Deng QW, Yu ZJ, Qu D. In vitro activities of telithromycin against Staphylococcus aureus biofilms compared with azithromycin, clindamycin, vancomycin and daptomycin. J Med Microbiol 2020; 69:120-131. [PMID: 31916929 DOI: 10.1099/jmm.0.001122] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Introduction. Staphylococcus aureus biofilms are difficult to treat and the effect of telithromycin treatment is still unclear.Aim. This study aimed to explore the effect of telithromycin against Staphylococcus aureus biofilms compared with azithromycin, clindamycin, vancomycin and daptomycin.Methodology. Eight methicillin-susceptible and eight methicillin-resistant S. aureus isolates (MSSA and MRSA, respectively) were used for this study. Biofilm biomasses were detected by crystal violet staining and the adherent cells in the established biofilms were quantified by determination of colony-forming units (c.f.u.). The RNA levels of biofilm formation-related genes were determined by RT-qPCR.Results. Telithromycin [8× minimum inhibitory concentration (MIC)] eradicated more established biofilms than azithromycin or clindamycin in the four MSSA isolates, and eliminated the established biofilms of six MRSA isolates more effectively than vancomycin or daptomycin. Telithromycin (8× MIC) killed more adherent cells in the established biofilms than azithromycin or clindamycin in the six MSSA isolates, and killed more adherent cells than vancomycin in all eight MRSA isolates. Daptomycin also showed an excellent effect on the adherent cells of MRSA isolates, with similarresults to telithromycin. The effect of a subinhibitory concentration of telithromycin (1/4× MIC) was significantly superior to that of azithromycin or clindamycin, inhibiting the biofilm formation of six MSSA isolates and seven MRSA isolates more effectively than vancomycin or daptomycin. The RNA levels of agrA, agrC, clfA, icaA and sigB decreased when treated with telithromycin (1/4× MIC).Conclusions. Telithromycin is more effective than azithromycin, clindamycin, vancomycin, or daptomycin against S. aureus biofilms.
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Affiliation(s)
- Jin-Xin Zheng
- Department of Infectious Diseases and the Key Laboratory of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518052, PR China.,Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Science and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, PR China
| | - Hao-Peng Tu
- Department of Infectious Diseases and the Key Laboratory of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518052, PR China
| | - Xiang Sun
- Department of Infectious Diseases and the Key Laboratory of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518052, PR China
| | - Guang-Jian Xu
- Department of Infectious Diseases and the Key Laboratory of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518052, PR China
| | - Jun-Wen Chen
- Department of Infectious Diseases and the Key Laboratory of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518052, PR China
| | - Qi-Wen Deng
- Department of Infectious Diseases and the Key Laboratory of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518052, PR China
| | - Zhi-Jian Yu
- Department of Infectious Diseases and the Key Laboratory of Endogenous Infection, Shenzhen Nanshan People's Hospital and The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518052, PR China
| | - Di Qu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Science and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, PR China
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The Impacts of msaABCR on sarA-Associated Phenotypes Are Different in Divergent Clinical Isolates of Staphylococcus aureus. Infect Immun 2020; 88:IAI.00530-19. [PMID: 31740526 PMCID: PMC6977130 DOI: 10.1128/iai.00530-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 11/07/2019] [Indexed: 12/27/2022] Open
Abstract
The staphylococcal accessory regulator (sarA) plays an important role in Staphylococcus aureus infections, including osteomyelitis, and the msaABCR operon has been implicated as an important factor in modulating expression of sarA Thus, we investigated the contribution of msaABCR to sarA-associated phenotypes in the S. aureus clinical isolates LAC and UAMS-1. Mutation of msaABCR resulted in reduced production of SarA and a reduced capacity to form a biofilm in both strains. Biofilm formation was enhanced in a LAC msa mutant by restoring the production of SarA, but this was not true in a UAMS-1 msa mutant. Similarly, extracellular protease production was increased in a LAC msa mutant but not a UAMS-1 msa mutant. This difference was reflected in the accumulation and distribution of secreted virulence factors and in the impact of extracellular proteases on biofilm formation in a LAC msa mutant. Most importantly, it was reflected in the relative impact of mutating msa as assessed in a murine osteomyelitis model, which had a significant impact in LAC but not in UAMS-1. In contrast, mutation of sarA had a greater impact on all of these in vitro and in vivo phenotypes than mutation of msaABCR, and it did so in both LAC and UAMS-1. These results suggest that, at least in osteomyelitis, it would be therapeutically preferable to target sarA rather than msaABCR to achieve the desired clinical result, particularly in the context of divergent clinical isolates of S. aureus.
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Castro RD, Pedroso SHSP, Sandes SHC, Silva GO, Luiz KCM, Dias RS, Filho RAT, Figueiredo HCP, Santos SG, Nunes AC, Souza MR. Virulence factors and antimicrobial resistance of Staphylococcus aureus isolated from the production process of Minas artisanal cheese from the region of Campo das Vertentes, Brazil. J Dairy Sci 2020; 103:2098-2110. [PMID: 31980224 DOI: 10.3168/jds.2019-17138] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 10/28/2019] [Indexed: 12/31/2022]
Abstract
Staphylococcus aureus is one of the main pathogens found in cheeses produced with raw milk, including Minas artisanal cheese from Brazil. However, information about S. aureus isolated from artisanal cheeses and its sources of production in small-scale dairies is very limited. We aimed to characterize the virulence factors of S. aureus isolated from raw milk, endogenous starter culture, Minas artisanal cheese, and cheese handlers from the region of Campo das Vertentes, Minas Gerais, Brazil. We identified the staphylococcal isolates by MALDI-TOF mass spectrometry. We evaluated biofilm production on Congo red agar and polystyrene plates. We used PCR to detect icaA, icaB, icaC, sea, seb, sec, sed, see, tsst-1, agr, and mecA. We evaluated the expression of staphylococcal toxin genes in PCR-positive staphylococcal isolates using quantitative reverse-transcription PCR, and we evaluated the production of these toxins and their hemolytic activity in vitro. We also evaluated the antimicrobial resistance profile of the staphylococcal isolates. For statistical analysis, we used cluster analysis, χ2 tests, and correspondence tests. We analyzed 76 staphylococcal isolates. According to PCR, 18.42, 18.42, 2.63, and 77.63% were positive for sea, tsst-1, sec, and agr, respectively. We found low expression of staphylococcal toxin genes according to quantitative reverse-transcription PCR, and only 2 staphylococcal isolates produced toxic shock syndrome toxins. A total of 43 staphylococcal isolates (56.58%) had hemolytic activity; 53 were biofilm-forming on Congo red agar (69.73%), and 62 on polystyrene plates (81.58%). None of the staphylococcal isolates expressed the mecA gene, and none presented a multi-drug resistance pattern. The highest resistance was observed for penicillin G (67.11%) in 51 isolates and for tetracycline (27.63%) in 21 isolates. The staphylococcal isolates we evaluated had toxigenic potential, with a higher prevalence of sea and tsst-1. Biofilm production was the main virulence factor of the studied bacteria. Six clusters were formed whose distribution frequencies differed for hemolytic activity, biofilm formation (qualitative and quantitative analyses), and resistance to penicillin, tetracycline, and erythromycin. These findings emphasize the need for effective measures to prevent staphylococcal food poisoning by limiting S. aureus growth and enterotoxin formation throughout the food production chain and the final product.
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Affiliation(s)
- R D Castro
- Departamento de Tecnologia e Inspeção de Produtos de Origem Animal, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil.
| | - S H S P Pedroso
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - S H C Sandes
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - G O Silva
- Departamento de Tecnologia e Inspeção de Produtos de Origem Animal, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - K C M Luiz
- Laboratório de Enterotoxinas de Alimentos, Fundação Ezequiel Dias, Belo Horizonte, 30510-010, Brazil
| | - R S Dias
- Laboratório de Enterotoxinas de Alimentos, Fundação Ezequiel Dias, Belo Horizonte, 30510-010, Brazil
| | - R A T Filho
- Departamento de Engenharia de Alimentos, Universidade Federal de Viçosa, Florestal, 35690-000, Brazil
| | - H C P Figueiredo
- Departamento de Medicina Veterinária Preventiva, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - S G Santos
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - A C Nunes
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - M R Souza
- Departamento de Tecnologia e Inspeção de Produtos de Origem Animal, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
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Zhou YF, Li L, Tao MT, Sun J, Liao XP, Liu YH, Xiong YQ. Linezolid and Rifampicin Combination to Combat cfr-Positive Multidrug-Resistant MRSA in Murine Models of Bacteremia and Skin and Skin Structure Infection. Front Microbiol 2020; 10:3080. [PMID: 31993042 PMCID: PMC6971047 DOI: 10.3389/fmicb.2019.03080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 12/19/2019] [Indexed: 01/16/2023] Open
Abstract
Linezolid resistance mediated by the cfr gene in MRSA represents a global concern. We investigated relevant phenotype differences between cfr-positive and -negative MRSA that contribute to pathogenesis, and the efficacy of linezolid-based combination therapies in murine models of bacteremia and skin and skin structure infection (SSSI). As a group, cfr-positive MRSA exhibited significantly reduced susceptibilities to the host defense peptides tPMPs, human neutrophil peptide-1 (hNP-1), and cathelicidin LL-37 (P < 0.01). In addition, increased binding to fibronectin (FN) and endothelial cells paralleled robust biofilm formation in cfr-positive vs. -negative MRSA. In vitro phenotypes of cfr-positive MRSA translated into poor outcomes of linezolid monotherapy in vivo in murine bacteremia and SSSI models. Importantly, rifampicin showed synergistic activity as a combinatorial partner with linezolid, and the EC50 of linezolid decreased 6-fold in the presence of rifampicin. Furthermore, this combination therapy displayed efficacy against cfr-positive MRSA at clinically relevant doses. Altogether, these data suggest that the use of linezolid in combination with rifampicin poses a viable therapeutic alternative for bacteremia and SSSI caused by cfr-positive multidrug resistant MRSA.
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Affiliation(s)
- Yu-Feng Zhou
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Liang Li
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, United States
| | - Meng-Ting Tao
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Jian Sun
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Xiao-Ping Liao
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Ya-Hong Liu
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
| | - Yan Q Xiong
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, United States.,David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
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Liao X, Jiang G, Wang J, Wang J. Retracted Article: Functional disruption of staphylococcal accessory regulator A from Staphylococcus aureus by silver ions. RSC Adv 2020; 10:33221-33226. [PMID: 35515077 PMCID: PMC9056660 DOI: 10.1039/d0ra06357f] [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: 07/21/2020] [Accepted: 08/31/2020] [Indexed: 11/21/2022] Open
Abstract
It was identified that SarA in S. aureus is a target of Ag+, which further expanded the antibacterial mechanism of Ag+.
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Affiliation(s)
- Xiangwen Liao
- School of Pharmacy
- Jiangxi Science & Technology Normal University
- Nanchang
- China
| | - Guijuan Jiang
- School of Pharmacy
- Jiangxi Science & Technology Normal University
- Nanchang
- China
| | - Jing Wang
- School of Pharmacy
- Jiangxi Science & Technology Normal University
- Nanchang
- China
| | - Jintao Wang
- School of Pharmacy
- Jiangxi Science & Technology Normal University
- Nanchang
- China
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Ghilini F, Pissinis DE, Miñán A, Schilardi PL, Diaz C. How Functionalized Surfaces Can Inhibit Bacterial Adhesion and Viability. ACS Biomater Sci Eng 2019; 5:4920-4936. [DOI: 10.1021/acsbiomaterials.9b00849] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Fiorela Ghilini
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, UNLP − CONICET, CC16 Suc 4 (1900), La Plata, Buenos Aires, Argentina
| | - Diego E. Pissinis
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, UNLP − CONICET, CC16 Suc 4 (1900), La Plata, Buenos Aires, Argentina
| | - Alejandro Miñán
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, UNLP − CONICET, CC16 Suc 4 (1900), La Plata, Buenos Aires, Argentina
| | - Patricia L. Schilardi
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, UNLP − CONICET, CC16 Suc 4 (1900), La Plata, Buenos Aires, Argentina
| | - Carolina Diaz
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, UNLP − CONICET, CC16 Suc 4 (1900), La Plata, Buenos Aires, Argentina
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MroQ Is a Novel Abi-Domain Protein That Influences Virulence Gene Expression in Staphylococcus aureus via Modulation of Agr Activity. Infect Immun 2019; 87:IAI.00002-19. [PMID: 30833335 DOI: 10.1128/iai.00002-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 02/23/2019] [Indexed: 01/07/2023] Open
Abstract
Numerous factors have, to date, been identified as playing a role in the regulation of Agr activity in Staphylococcus aureus, including transcription factors, antisense RNAs, and host elements. Herein we investigated the product of SAUSA300_1984 (termed MroQ), a transmembrane Abi-domain/M79 protease-family protein, as a novel effector of this system. Using a USA300 mroQ mutant, we observed a drastic reduction in proteolysis, hemolysis, and pigmentation that was fully complementable. This appears to result from diminished agr activity, as transcriptional analysis revealed significant decreases in expression of both RNAII and RNAIII in the mroQ mutant. Such effects appear to be direct, rather than indirect, as known agr effectors demonstrated limited alterations in their activity upon mroQ disruption. A comparison of RNA sequencing data sets for both mroQ and agr mutants revealed a profound overlap in their regulomes, with the majority of factors affected being known virulence determinants. Importantly, the preponderance of alterations in expression were more striking in the agr mutant, indicating that MroQ is necessary, but not sufficient, for Agr function. Mechanism profiling revealed that putative residues for metalloprotease activity within MroQ are required for its Agr-controlling effect; however, this was not wielded at the level of AgrD processing. Virulence assessment demonstrated that both mroQ and agr mutants exhibited increased formation of renal abscesses but decreased skin abscess formation alongside diminished dermonecrosis. Collectively, we present the characterization of a novel agr effector in S. aureus which would appear to be a direct regulator, potentially functioning via interaction with the AgrC histidine kinase.
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Abstract
Staphylococcus aureus is one of the most important human pathogens that is responsible for a variety of diseases ranging from skin and soft tissue infections to endocarditis and sepsis. In recent decades, the treatment of staphylococcal infections has become increasingly difficult as the prevalence of multi-drug resistant strains continues to rise. With increasing mortality rates and medical costs associated with drug resistant strains, there is an urgent need for alternative therapeutic options. Many innovative strategies for alternative drug development are being pursued, including disruption of biofilms, inhibition of virulence factor production, bacteriophage-derived antimicrobials, anti-staphylococcal vaccines, and light-based therapies. While many compounds and methods still need further study to determine their feasibility, some are quickly approaching clinical application and may be available in the near future.
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Yong YY, Dykes GA, Choo WS. Biofilm formation by staphylococci in health-related environments and recent reports on their control using natural compounds. Crit Rev Microbiol 2019; 45:201-222. [PMID: 30786799 DOI: 10.1080/1040841x.2019.1573802] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Staphylococci are Gram-positive bacteria that are ubiquitous in the environment and able to form biofilms on a range of surfaces. They have been associated with a range of human health issues such as medical device-related infection, localized skin infection, or direct infection caused by toxin production. The extracellular material produced by these bacteria resists antibiotics and host defence mechanism which complicates the treatment process. The commonly reported Staphylococcus species are Staphylococcus aureus and S. epidermidis as they inhabit human bodies. However, the emergence of other staphylococci, such as S. haemolyticus, S. lugdunensis, S. saprophyticus, S. capitis, S. saccharolyticus, S. warneri, S. cohnii, and S. hominis, is also of concern and they have been associated with biofilm formation. This review critically assesses recent cases on the biofilm formation by S. aureus, S. epidermidis, and other staphylococci reported in health-related environments. The control of biofilm formation by staphylococci using natural compounds is specifically discussed as they represent potential anti-biofilm agents which may reduce the burden of antibiotic resistance.
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Affiliation(s)
- Yi Yi Yong
- a School of Science , Monash University Malaysia , Selangor , Malaysia
| | - Gary A Dykes
- b School of Public Health , Curtin University , Bentley , Australia
| | - Wee Sim Choo
- a School of Science , Monash University Malaysia , Selangor , Malaysia
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Abstract
Staphylococci, with the leading species Staphylococcus aureus and Staphylococcus epidermidis, are the most frequent causes of infections on indwelling medical devices. The biofilm phenotype that those bacteria adopt during device-associated infection facilitates increased resistance to antibiotics and host immune defenses. This review presents and discusses the molecular mechanisms contributing to staphylococcal biofilm development and their in-vivo importance. Furthermore, it summarizes current strategies for the development of therapeutics against staphylococcal biofilm-associated infection.
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