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Ersoy SC, Proctor RA, Rose WE, Abdelhady W, Fan SH, Madrigal SL, Elsayed AM, Chambers HF, Sobral RG, Bayer AS. Sensitizing methicillin-resistant Staphylococcus aureus (MRSA) to cefuroxime: the synergic effect of bicarbonate and the wall teichoic acid inhibitor ticlopidine. Antimicrob Agents Chemother 2024; 68:e0162723. [PMID: 38349162 PMCID: PMC10916381 DOI: 10.1128/aac.01627-23] [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: 12/08/2023] [Accepted: 01/18/2024] [Indexed: 03/07/2024] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) strains are a major challenge for clinicians due, in part, to their resistance to most β-lactams, the first-line treatment for methicillin-susceptible S. aureus. A phenotype termed "NaHCO3-responsiveness" has been identified, wherein many clinical MRSA isolates are rendered susceptible to standard-of-care β-lactams in the presence of physiologically relevant concentrations of NaHCO3, in vitro and ex vivo; moreover, such "NaHCO3-responsive" isolates can be effectively cleared by β-lactams from target tissues in experimental infective endocarditis (IE). One mechanistic impact of NaHCO3 exposure on NaHCO3-responsive MRSA is to repress WTA synthesis. This NaHCO3 effect mimics the phenotype of tarO-deficient MRSA, including sensitization to the PBP2-targeting β-lactam, cefuroxime (CFX). Herein, we further investigated the impacts of NaHCO3 exposure on CFX susceptibility in the presence and absence of a WTA synthesis inhibitor, ticlopidine (TCP), in a collection of clinical MRSA isolates from skin and soft tissue infections (SSTI) and bloodstream infections (BSI). NaHCO3 and/or TCP enhanced susceptibility to CFX in vitro, by both minimum inhibitor concentration (MIC) and time-kill assays, as well as in an ex vivo simulated endocarditis vegetations (SEV) model, in NaHCO3-responsive MRSA. Furthermore, in experimental IE (presumably in the presence of endogenous NaHCO3), pre-exposure to TCP prior to infection sensitized the NaHCO3-responsive MRSA strain (but not the non-responsive strain) to enhanced clearances by CFX in target tissues. These data support the notion that NaHCO3 is acting similarly to WTA synthesis inhibitors, and that such inhibitors have potential translational applications in the treatment of certain MRSA strains in conjunction with specific β-lactam agents.
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Affiliation(s)
- Selvi C. Ersoy
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Richard A. Proctor
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Warren E. Rose
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Wessam Abdelhady
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Sook-Ha Fan
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
| | | | - Ahmed M. Elsayed
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Henry F. Chambers
- University of California-San Francisco School of Medicine, San Francisco, California, USA
| | - Rita G. Sobral
- Laboratory of Molecular Microbiology of Bacterial Pathogens, UCIBIO, Applied Molecular Biosciences Unit, Department of Life Sciences, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
| | - Arnold S. Bayer
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
- David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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2
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Zeden MS, Gallagher LA, Bueno E, Nolan AC, Ahn J, Shinde D, Razvi F, Sladek M, Burke Ó, O’Neill E, Fey PD, Cava F, Thomas VC, O’Gara JP. Metabolic reprogramming and altered cell envelope characteristics in a pentose phosphate pathway mutant increases MRSA resistance to β-lactam antibiotics. PLoS Pathog 2023; 19:e1011536. [PMID: 37486930 PMCID: PMC10399904 DOI: 10.1371/journal.ppat.1011536] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 08/03/2023] [Accepted: 07/04/2023] [Indexed: 07/26/2023] Open
Abstract
Central metabolic pathways control virulence and antibiotic resistance, and constitute potential targets for antibacterial drugs. In Staphylococcus aureus the role of the pentose phosphate pathway (PPP) remains largely unexplored. Mutation of the 6-phosphogluconolactonase gene pgl, which encodes the only non-essential enzyme in the oxidative phase of the PPP, significantly increased MRSA resistance to β-lactam antibiotics, particularly in chemically defined media with physiologically-relevant concentrations of glucose, and reduced oxacillin (OX)-induced lysis. Expression of the methicillin-resistance penicillin binding protein 2a and peptidoglycan architecture were unaffected. Carbon tracing and metabolomics revealed extensive metabolic reprogramming in the pgl mutant including increased flux to glycolysis, the TCA cycle, and several cell envelope precursors, which was consistent with increased β-lactam resistance. Morphologically, pgl mutant cells were smaller than wild-type with a thicker cell wall and ruffled surface when grown in OX. The pgl mutation reduced resistance to Congo Red, sulfamethoxazole and oxidative stress, and increased resistance to targocil, fosfomycin and vancomycin. Levels of lipoteichoic acids (LTAs) were significantly reduced in pgl, which may limit cell lysis, while the surface charge of pgl cells was significantly more positive. A vraG mutation in pgl reversed the increased OX resistance phenotype, and partially restored wild-type surface charge, but not LTA levels. Mutations in vraF or graRS from the VraFG/GraRS complex that regulates DltABCD-mediated d-alanylation of teichoic acids (which in turn controls β-lactam resistance and surface charge), also restored wild-type OX susceptibility. Collectively these data show that reduced levels of LTAs and OX-induced lysis combined with a VraFG/GraRS-dependent increase in cell surface positive charge are accompanied by significantly increased OX resistance in an MRSA pgl mutant.
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Affiliation(s)
- Merve S. Zeden
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Laura A. Gallagher
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Emilio Bueno
- Department of Molecular Biology, Umeå University, MIMS—Laboratory for Molecular Infection Medicine Sweden, Umeå, Sweden
| | - Aaron C. Nolan
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Jongsam Ahn
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Dhananjay Shinde
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Fareha Razvi
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Margaret Sladek
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Órla Burke
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Eoghan O’Neill
- Department of Clinical Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Paul D. Fey
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Felipe Cava
- Department of Molecular Biology, Umeå University, MIMS—Laboratory for Molecular Infection Medicine Sweden, Umeå, Sweden
| | - Vinai C. Thomas
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - James P. O’Gara
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
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Lu Y, Chen F, Zhao Q, Cao Q, Chen R, Pan H, Wang Y, Huang H, Huang R, Liu Q, Li M, Bae T, Liang H, Lan L. Modulation of MRSA virulence gene expression by the wall teichoic acid enzyme TarO. Nat Commun 2023; 14:1594. [PMID: 36949052 PMCID: PMC10032271 DOI: 10.1038/s41467-023-37310-5] [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: 07/01/2022] [Accepted: 03/10/2023] [Indexed: 03/24/2023] Open
Abstract
Phenol-soluble modulins (PSMs) and Staphylococcal protein A (SpA) are key virulence determinants for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), an important human pathogen that causes a wide range of diseases. Here, using chemical and genetic approaches, we show that inhibition of TarO, the first enzyme in the wall teichoic acid (WTA) biosynthetic pathway, decreases the expression of genes encoding PSMs and SpA in the prototypical CA-MRSA strain USA300 LAC. Mechanistically, these effects are linked to the activation of VraRS two-component system that directly represses the expression of accessory gene regulator (agr) locus and spa. The activation of VraRS was due in part to the loss of the functional integrity of penicillin-binding protein 2 (PBP2) in a PBP2a-dependent manner. TarO inhibition can also activate VraRS in a manner independent of PBP2a. We provide multiple lines of evidence that accumulation of lipid-linked peptidoglycan precursors is a trigger for the activation of VraRS. In sum, our results reveal that WTA biosynthesis plays an important role in the regulation of virulence gene expression in CA-MRSA, underlining TarO as an attractive target for anti-virulence therapy. Our data also suggest that acquisition of PBP2a-encoding mecA gene can impart an additional regulatory layer for the modulation of key signaling pathways in S. aureus.
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Affiliation(s)
- Yunfu Lu
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Feifei Chen
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- College of Life Science, Northwest University, Xi'an, 710127, China
| | - Qingmin Zhao
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Qiao Cao
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- College of Life Science, Northwest University, Xi'an, 710127, China
| | - Rongrong Chen
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Huiwen Pan
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Yanhui Wang
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Haixin Huang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Ruimin Huang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Qian Liu
- Department of Laboratory Medicine, School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Min Li
- Department of Laboratory Medicine, School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Taeok Bae
- Department of Microbiology and Immunology, Indiana University School of Medicine-Northwest, Gary, IN, 46408, USA
| | - Haihua Liang
- College of Life Science, Northwest University, Xi'an, 710127, China.
- School of Medicine, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Lefu Lan
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China.
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China.
- College of Life Science, Northwest University, Xi'an, 710127, China.
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Zeden MS, Gallagher LA, Bueno E, Nolan AC, Ahn J, Shinde D, Razvi F, Sladek M, Burke Ó, O'Neill E, Fey PD, Cava F, Thomas VC, O'Gara JP. Metabolic reprogramming and flux to cell envelope precursors in a pentose phosphate pathway mutant increases MRSA resistance to β-lactam antibiotics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.03.530734. [PMID: 36945400 PMCID: PMC10028837 DOI: 10.1101/2023.03.03.530734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Central metabolic pathways controls virulence and antibiotic resistance, and constitute potential targets for antibacterial drugs. In Staphylococcus aureus the role of the pentose phosphate pathway (PPP) remains largely unexplored. Mutation of the 6-phosphogluconolactonase gene pgl, which encodes the only non-essential enzyme in the oxidative phase of the PPP, significantly increased MRSA resistance to β-lactam antibiotics, particularly in chemically defined media with glucose, and reduced oxacillin (OX)-induced lysis. Expression of the methicillin-resistance penicillin binding protein 2a and peptidoglycan architecture were unaffected. Carbon tracing and metabolomics revealed extensive metabolic reprogramming in the pgl mutant including increased flux to glycolysis, the TCA cycle, and several cell envelope precursors, which was consistent with increased β-lactam resistance. Morphologically, pgl mutant cells were smaller than wild-type with a thicker cell wall and ruffled surface when grown in OX. Further evidence of the pleiotropic effect of the pgl mutation was reduced resistance to Congo Red, sulfamethoxazole and oxidative stress, and increased resistance to targocil, fosfomycin and vancomycin. Reduced binding of wheat germ agglutinin (WGA) to pgl was indicative of lower wall teichoic acid/lipoteichoic acid levels or altered teichoic acid structures. Mutations in the vraFG or graRS loci reversed the increased OX resistance phenotype and restored WGA binding to wild-type levels. VraFG/GraRS was previously implicated in susceptibility to cationic antimicrobial peptides and vancomycin, and these data reveal a broader role for this multienzyme membrane complex in the export of cell envelope precursors or modifying subunits required for resistance to diverse antimicrobial agents. Altogether our study highlights important roles for the PPP and VraFG/GraRS in β-lactam resistance, which will support efforts to identify new drug targets and reintroduce β-lactams in combination with adjuvants or other antibiotics for infections caused by MRSA and other β-lactam resistant pathogens. Author summary High-level resistance to penicillin-type (β-lactam) antibiotics significantly limits the therapeutic options for patients with MRSA infections necessitating the use of newer agents, for which reduced susceptibility has already been described. Here we report for the first time that the central metabolism pentose phosphate pathway controls MRSA resistance to penicillin-type antibiotics. We comprehensively demonstrated that mutation of the PPP gene pgl perturbed metabolism in MRSA leading to increased flux to cell envelope precursors to drive increased antibiotic resistance. Moreover, increased resistance was dependent on the VraRG/GraRS multienzyme membrane complex previously implicated in resistance to antimicrobial peptides and vancomycin. Our data thus provide new insights on MRSA mechanisms of β-lactam resistance, which will support efforts to expand the treatment options for infections caused by this and other antimicrobial resistant pathogens.
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Purine Nucleosides Interfere with c-di-AMP Levels and Act as Adjuvants To Re-Sensitize MRSA To β-Lactam Antibiotics. mBio 2023; 14:e0247822. [PMID: 36507833 PMCID: PMC9973305 DOI: 10.1128/mbio.02478-22] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The purine-derived signaling molecules c-di-AMP and (p)ppGpp control mecA/PBP2a-mediated β-lactam resistance in methicillin-resistant Staphylococcus aureus (MRSA) raise the possibility that purine availability can control antibiotic susceptibility. Consistent with this, exogenous guanosine and xanthosine, which are fluxed through the GTP branch of purine biosynthesis, were shown to significantly reduce MRSA β-lactam resistance. In contrast, adenosine (fluxed to ATP) significantly increased oxacillin resistance, whereas inosine (which can be fluxed to ATP and GTP via hypoxanthine) only marginally increased oxacillin susceptibility. Furthermore, mutations that interfere with de novo purine synthesis (pur operon), transport (NupG, PbuG, PbuX) and the salvage pathway (DeoD2, Hpt) increased β-lactam resistance in MRSA strain JE2. Increased resistance of a nupG mutant was not significantly reversed by guanosine, indicating that NupG is required for guanosine transport, which is required to reduce β-lactam resistance. Suppressor mutants resistant to oxacillin/guanosine combinations contained several purine salvage pathway mutations, including nupG and hpt. Guanosine significantly increased cell size and reduced levels of c-di-AMP, while inactivation of GdpP, the c-di-AMP phosphodiesterase negated the impact of guanosine on β-lactam susceptibility. PBP2a expression was unaffected in nupG or deoD2 mutants, suggesting that guanosine-induced β-lactam susceptibility may result from dysfunctional c-di-AMP-dependent osmoregulation. These data reveal the therapeutic potential of purine nucleosides, as β-lactam adjuvants that interfere with the normal activation of c-di-AMP are required for high-level β-lactam resistance in MRSA. IMPORTANCE The clinical burden of infections caused by antimicrobial resistant (AMR) pathogens is a leading threat to public health. Maintaining the effectiveness of existing antimicrobial drugs or finding ways to reintroduce drugs to which resistance is widespread is an important part of efforts to address the AMR crisis. Predominantly, the safest and most effective class of antibiotics are the β-lactams, which are no longer effective against methicillin-resistant Staphylococcus aureus (MRSA). Here, we report that the purine nucleosides guanosine and xanthosine have potent activity as adjuvants that can resensitize MRSA to oxacillin and other β-lactam antibiotics. Mechanistically, exposure of MRSA to these nucleosides significantly reduced the levels of the cyclic dinucleotide c-di-AMP, which is required for β-lactam resistance. Drugs derived from nucleotides are widely used in the treatment of cancer and viral infections highlighting the clinical potential of using purine nucleosides to restore or enhance the therapeutic effectiveness of β-lactams against MRSA and potentially other AMR pathogens.
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Kaur B, Gupta J, Sharma S, Sharma D, Sharma S. Focused review on dual inhibition of quorum sensing and efflux pumps: A potential way to combat multi drug resistant Staphylococcus aureus infections. Int J Biol Macromol 2021; 190:33-43. [PMID: 34480904 DOI: 10.1016/j.ijbiomac.2021.08.199] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 11/19/2022]
Abstract
Staphylococcus aureus is a common cause of skin infections, food poisoning and severe life-threatening infections. Methicillin-Resistant Staphylococcus aureus (MRSA) is known to cause chronic nosocomial infections by virtue of its multidrug resistance and biofilm formation mechanisms. The antimicrobial resistance owned by S. aureus is primarily due to efflux pumps and formation of microbial biofilms. These drug resistant, sessile and densely packed microbial communities possess various mechanisms including quorum sensing and drug efflux. Quorum sensing is a cooperative physiological process which is used by bacterial cells for social interaction and signal transduction in biofilm formation whereas efflux of drugs is derived by efflux pumps. Apart from their significant role in multidrug resistance, efflux pumps also contribute to transporting cell signalling molecules and due to their occurrence; we face the frightening possibility that we will enter the pre-antibiotic era soon. Compounds that modulate efflux pumps are also known as efflux pump inhibitors (EPI's) that act in a synergistic manner and potentiate the antibiotics efficacy which has been considered as a promising approach to encounter bacterial resistance. EPIs inhibit the mechanism of drug efflux s as well as transport of quorum sensing signalling molecules which are the supreme contributors of miscellaneous virulence factors. This review presents an accomplishments of the recent investigations allied to efflux pump inhibitors against S. aureus and also focus on related correspondence between quorum sensing system and efflux pump inhibitors in terms of S. aureus and MRSA biofilms that may open a new avenue for controlling MRSA infections.
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Affiliation(s)
- Bhawandeep Kaur
- Department of Medical Laboratory Sciences, Lovely Professional University, Phagwara, Punjab 144411, India
| | - Jeena Gupta
- Department of Biochemistry, Lovely Professional University, Phagwara, Punjab 144411, India
| | - Sarika Sharma
- Department of Life Sciences, Arni University, Indora, Kangra, H.P. 176402, India
| | - Divakar Sharma
- Department of Microbiology, Maulana Azad Medical College, New Delhi 110002, India.
| | - Sandeep Sharma
- Department of Medical Laboratory Sciences, Lovely Professional University, Phagwara, Punjab 144411, India.
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Salam AM, Porras G, Cho YSK, Brown MM, Risener CJ, Marquez L, Lyles JT, Bacsa J, Horswill AR, Quave CL. Castaneroxy A From the Leaves of Castanea sativa Inhibits Virulence in Staphylococcus aureus. Front Pharmacol 2021; 12:640179. [PMID: 34262448 PMCID: PMC8274328 DOI: 10.3389/fphar.2021.640179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 06/01/2021] [Indexed: 01/05/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) represents one of the most serious infectious disease concerns worldwide, with the CDC labeling it a "serious threat" in 2019. The current arsenal of antibiotics works by targeting bacterial growth and survival, which exerts great selective pressure for the development of resistance. The development of novel anti-infectives that inhibit quorum sensing and thus virulence in MRSA has been recurrently proposed as a promising therapeutic approach. In a follow-up of a study examining the MRSA quorum sensing inhibitory activity of extracts of Italian plants used in local traditional medicine, 224C-F2 was reported as a bioactive fraction of a Castanea sativa (European chestnut) leaf extract. The fraction demonstrated high activity in vitro and effective attenuation of MRSA pathogenicity in a mouse model of skin infection. Through further bioassay-guided fractionation using reverse-phase high performance liquid chromatography, a novel hydroperoxy cycloartane triterpenoid, castaneroxy A (1), was isolated. Its structure was established by nuclear magnetic resonance, mass spectrometry and X-ray diffraction analyses. Isomers of 1 were also detected in an adjacent fraction. In a series of assays assessing inhibition of markers of MRSA virulence, 1 exerted activities in the low micromolar range. It inhibited agr::P3 activation (IC50 = 31.72 µM), δ-toxin production (IC50 = 31.72 µM in NRS385), supernatant cytotoxicity to HaCaT human keratinocytes (IC50 = 7.93 µM in NRS385), and rabbit erythrocyte hemolytic activity (IC50 = 7.93 µM in LAC). Compound 1 did not inhibit biofilm production, and at high concentrations it exerted cytotoxicity against human keratinocytes greater than that of 224C-F2. Finally, 1 reduced dermonecrosis in a murine model of MRSA infection. The results establish 1 as a promising antivirulence candidate for development against MRSA.
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Affiliation(s)
- Akram M Salam
- Program in Molecular and Systems Pharmacology, Laney Graduate School, Emory University, Atlanta, GA, United States
| | - Gina Porras
- Center for the Study of Human Health, Emory University, Atlanta, GA, United States
| | - Young-Saeng K Cho
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Morgan M Brown
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Caitlin J Risener
- Program in Molecular and Systems Pharmacology, Laney Graduate School, Emory University, Atlanta, GA, United States
| | - Lewis Marquez
- Program in Molecular and Systems Pharmacology, Laney Graduate School, Emory University, Atlanta, GA, United States
| | - James T Lyles
- Center for the Study of Human Health, Emory University, Atlanta, GA, United States
| | - John Bacsa
- Department of Chemistry, Emory University, Atlanta, GA, United States
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Cassandra L Quave
- Center for the Study of Human Health, Emory University, Atlanta, GA, United States.,Department of Dermatology, Emory University School of Medicine, Atlanta, GA, United States.,Antibiotic Resistance Center, Emory University, Atlanta, GA, United States
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8
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García-de-la-Mària C, Gasch O, Castañeda X, García-González J, Soy D, Cañas MA, Ambrosioni J, Almela M, Pericàs JM, Téllez A, Falces C, Hernández-Meneses M, Sandoval E, Quintana E, Vidal B, Tolosana JM, Fuster D, Llopis J, Moreno A, Marco F, Miró JM. Cloxacillin or fosfomycin plus daptomycin combinations are more active than cloxacillin monotherapy or combined with gentamicin against MSSA in a rabbit model of experimental endocarditis. J Antimicrob Chemother 2021; 75:3586-3592. [PMID: 32853336 DOI: 10.1093/jac/dkaa354] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 07/16/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND In vitro and in vivo activity of daptomycin alone or plus either cloxacillin or fosfomycin compared with cloxacillin alone and cloxacillin plus gentamicin were evaluated in a rabbit model of MSSA experimental endocarditis (EE). METHODS Five MSSA strains were used in the in vitro time-kill studies at standard (105-106 cfu/mL) and high (108 cfu/mL) inocula. In the in vivo EE model, the following antibiotic combinations were evaluated: cloxacillin (2 g/4 h) alone or combined with gentamicin (1 mg/kg/8 h) or daptomycin (6 mg/kg once daily); and daptomycin (6 mg/kg/day) alone or combined with fosfomycin (2 g/6 h). RESULTS At standard and high inocula, daptomycin plus fosfomycin or cloxacillin were bactericidal against 4/5 and 5/5 strains, respectively, while cloxacillin plus gentamicin was bactericidal against 3/5 strains at standard inocula but against none at high inocula. Fosfomycin, cloxacillin, gentamicin and daptomycin MIC/MBCs of the MSSA-678 strain used in the EE model were: 8/64, 0.25/0.5, 0.25/0.5 and 1/8 mg/L, respectively. Adding gentamicin to cloxacillin significantly reduced bacterial density in vegetations compared with cloxacillin monotherapy (P = 0.026). Adding fosfomycin or cloxacillin to daptomycin [10/11 (93%) and 8/11 (73%), respectively] significantly improved the efficacy of daptomycin in sterilizing vegetations [0/11 (0%), P < 0.001 for both combinations] and showed better activity than cloxacillin alone [0/10 (0%), P < 0.001 for both combinations] and cloxacillin plus gentamicin [3/10 (30%), P = 0.086 for cloxacillin plus daptomycin and P = 0.008 for fosfomycin plus daptomycin]. No recovered isolates showed increased daptomycin MIC. CONCLUSIONS The addition of cloxacillin or fosfomycin to daptomycin is synergistic and rapidly bactericidal, showing better activity than cloxacillin plus gentamicin for treating MSSA EE, supporting their clinical use.
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Affiliation(s)
- Cristina García-de-la-Mària
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Oriol Gasch
- Hospital Parc Tauli de Sabadell, University Autònoma of Barcelona, Spain
| | - Ximena Castañeda
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Javier García-González
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Dolors Soy
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Maria-Alexandra Cañas
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Juan Ambrosioni
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Manel Almela
- Microbiology Department, Centre Diagnòstic Biomèdic, Hospital Clínic, Barcelona, Spain
| | - Juan M Pericàs
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Adrián Téllez
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Carlos Falces
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Marta Hernández-Meneses
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Elena Sandoval
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Eduard Quintana
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Barbara Vidal
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Jose M Tolosana
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - David Fuster
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Jaume Llopis
- Department of Statistics, Faculty of Biology, University of Barcelona, Spain
| | - Asuncion Moreno
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Francesc Marco
- Microbiology Department, Centre Diagnòstic Biomèdic, Hospital Clínic, Barcelona, Spain.,ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Jose M Miró
- Hospital Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
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9
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Gallagher LA, Shears RK, Fingleton C, Alvarez L, Waters EM, Clarke J, Bricio-Moreno L, Campbell C, Yadav AK, Razvi F, O'Neill E, O'Neill AJ, Cava F, Fey PD, Kadioglu A, O'Gara JP. Impaired Alanine Transport or Exposure to d-Cycloserine Increases the Susceptibility of MRSA to β-lactam Antibiotics. J Infect Dis 2020; 221:1000-1016. [PMID: 31628459 DOI: 10.1093/infdis/jiz542] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 10/14/2019] [Indexed: 12/29/2022] Open
Abstract
Prolonging the clinical effectiveness of β-lactams, which remain first-line antibiotics for many infections, is an important part of efforts to address antimicrobial resistance. We report here that inactivation of the predicted d-cycloserine (DCS) transporter gene cycA resensitized methicillin-resistant Staphylococcus aureus (MRSA) to β-lactam antibiotics. The cycA mutation also resulted in hypersusceptibility to DCS, an alanine analogue antibiotic that inhibits alanine racemase and d-alanine ligase required for d-alanine incorporation into cell wall peptidoglycan. Alanine transport was impaired in the cycA mutant, and this correlated with increased susceptibility to oxacillin and DCS. The cycA mutation or exposure to DCS were both associated with the accumulation of muropeptides with tripeptide stems lacking the terminal d-ala-d-ala and reduced peptidoglycan cross-linking, prompting us to investigate synergism between β-lactams and DCS. DCS resensitized MRSA to β-lactams in vitro and significantly enhanced MRSA eradication by oxacillin in a mouse bacteremia model. These findings reveal alanine transport as a new therapeutic target to enhance the susceptibility of MRSA to β-lactam antibiotics.
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Affiliation(s)
- Laura A Gallagher
- School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Rebecca K Shears
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, United Kingdom
| | - Claire Fingleton
- School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Laura Alvarez
- Molecular Infection Medicine, Sweden, Molecular Biology Department, Umeå University, Umeå, Sweden
| | - Elaine M Waters
- School of Natural Sciences, National University of Ireland, Galway, Ireland.,Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, United Kingdom
| | - Jenny Clarke
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, United Kingdom
| | - Laura Bricio-Moreno
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, United Kingdom
| | | | - Akhilesh K Yadav
- Molecular Infection Medicine, Sweden, Molecular Biology Department, Umeå University, Umeå, Sweden
| | - Fareha Razvi
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Eoghan O'Neill
- Department of Clinical Microbiology, Royal College of Surgeons in Ireland, Connolly Hospital, Dublin, Ireland
| | - Alex J O'Neill
- Antimicrobial Research Centre, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Felipe Cava
- Molecular Infection Medicine, Sweden, Molecular Biology Department, Umeå University, Umeå, Sweden
| | - Paul D Fey
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Aras Kadioglu
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, United Kingdom
| | - James P O'Gara
- School of Natural Sciences, National University of Ireland, Galway, Ireland
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10
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Yamashita Y, Nagaoka K, Kimura H, Suzuki M, Fukumoto T, Hayasaka K, Kaku N, Morinaga Y, Yanagihara K, Konno S. Pathogenic Effect of Prevotella intermedia on a Mouse Pneumonia Model Due to Methicillin-Resistant Staphylococcus aureus With Up-Regulated α-Hemolysin Expression. Front Microbiol 2020; 11:587235. [PMID: 33117325 PMCID: PMC7575765 DOI: 10.3389/fmicb.2020.587235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 09/14/2020] [Indexed: 11/13/2022] Open
Abstract
Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a common causative agent of pneumonia; however, the detailed mechanism underlying severe MRSA pneumonia, including association with oral hygiene or periodontitis, remains poorly characterized. In this study, we examined the pathogenic effect of Prevotella intermedia, a major periodontopathic pathogen, on MRSA pneumonia. Methods: The pathogenic effect of the supernatant of P. intermedia (Pi Sup) was investigated in a murine MRSA pneumonia model, using several clinical strains; whereas the bactericidal activity of polymorphonuclear leukocytes (PMNs) was investigated in vitro. The effect of Pi Sup on messenger RNA (mRNA) expression of the toxin/quorum sensing system (rnaIII) was investigated by quantitative reverse transcription PCR both in vitro and in vivo. Results: Mice infected by hospital-acquired MRSA (HA-MRSA) with Pi Sup exhibited a significantly lower survival rate, higher bacterial loads in the lungs, and higher α-hemolysin (hla) expression in the lungs, than those without Pi Sup. A similar effect of Pi Sup was not observed with MRSA strains producing Panton-Valentine leucocidin (PVL) or toxic shock syndrome toxin (TSST). In vitro, Pi Sup suppressed bactericidal activity of PMNs against the HA-MRSA strain. HA-MRSA was the clinical strain with the highest ability to proliferate in the lungs and was accompanied by time-dependent up-regulation of rnaIII and hla. Conclusions: Our results provide novel evidence that the product of P. intermedia exerts a pathogenic effect on MRSA pneumonia, in particular with a strain exhibiting strong proliferation in the lower airway tract. Moreover, our results indicate that P. intermedia affects MRSA toxin expression via quorum sensing in a strain-dependent fashion, which might be important for understanding the pathogenesis of severe MRSA pneumonia.
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Affiliation(s)
- Yu Yamashita
- Department of Respiratory Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Kentaro Nagaoka
- Department of Respiratory Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Hiroki Kimura
- Department of Respiratory Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Masaru Suzuki
- Department of Respiratory Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Tatsuya Fukumoto
- Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan
| | - Kasumi Hayasaka
- Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Japan
| | - Norihito Kaku
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Yoshitomo Morinaga
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Katsunori Yanagihara
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Satoshi Konno
- Department of Respiratory Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
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11
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Song HS, Choi TR, Han YH, Park YL, Park JY, Yang SY, Bhatia SK, Gurav R, Kim YG, Kim JS, Joo HS, Yang YH. Increased resistance of a methicillin-resistant Staphylococcus aureus Δagr mutant with modified control in fatty acid metabolism. AMB Express 2020; 10:64. [PMID: 32266584 PMCID: PMC7138893 DOI: 10.1186/s13568-020-01000-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 03/28/2020] [Indexed: 02/08/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) strains are distinct from general Staphylococcus strains with respect to the composition of the membrane, ability to form a thicker biofilm, and, importantly, ability to modify the target of antibiotics to evade their activity. The agr gene is an accessory global regulator of gram-positive bacteria that governs virulence or resistant mechanisms and therefore an important target for the control of resistant strains. However, the mechanism by which agr impacts resistance to β-lactam antibiotics remains unclear. In the present study, we found the Δagr mutant strain having higher resistance to high concentrations of β-lactam antibiotics such as oxacillin and ampicillin. To determine the influence of variation in the microenvironment of cells between the parental and mutant strains, fatty acid analysis of the supernatant, total lipids, and phospholipid fatty acids were compared. The Δagr mutant strain tended to produce fewer fatty acids and retained lower amounts of C16, C18 fatty acids in the supernatant. Phospholipid analysis showed a dramatic increase in the hydrophobic longer-chain fatty acids in the membrane. To target membrane, we applied several surfactants and found that sorbitan monolaurate (Span20) had a synergistic effect with oxacillin by decreasing biofilm formation and growth. These findings indicate that agr deletion allows for MRSA to resist antibiotics via several changes including constant expression of mecA, fatty acid metabolism, and biofilm thickening.
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12
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Jo SH, Song WS, Park HG, Lee JS, Jeon HJ, Lee YH, Kim W, Joo HS, Yang YH, Kim JS, Kim YG. Multi-omics based characterization of antibiotic response in clinical isogenic isolates of methicillin-susceptible/-resistant Staphylococcus aureus. RSC Adv 2020; 10:27864-27873. [PMID: 35516943 PMCID: PMC9055585 DOI: 10.1039/d0ra05407k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 07/17/2020] [Indexed: 12/30/2022] Open
Abstract
As demands for new antibiotics and strategies to control methicillin-resistant Staphylococcus aureus (MRSA) increase, there have been efforts to obtain more accurate and abundant information about the mechanism of the bacterial responses to antibiotics. However, most of the previous studies have investigated responses to antibiotics without considering the genetic differences between MRSA and methicillin-susceptible S. aureus (MSSA). Here, we initially applied a multi-omics approach into the clinical isolates (i.e., S. aureus WKZ-1 (MSSA) and S. aureus WKZ-2 (MRSA)) that are isogenic except for the mobile genetic element called staphylococcal cassette chromosome mec (SCCmec) type IV to explore the response to β-lactam antibiotics (oxacillin). First, the isogenic pair showed a similar metabolism without oxacillin treatment. The quantitative proteomics demonstrated that proteins involved in peptidoglycan biosynthesis (MurZ, PBP2, SgtB, PrsA), two-component systems (VrsSR, WalR, SaeSR, AgrA), oxidative stress (MsrA1, MsrB), and stringent response (RelQ) were differentially regulated after the oxacillin treatment of the isogenic isolates. In addition, targeted metabolic profiling showed that metabolites belonging to the building blocks (lysine, glutamine, acetyl-CoA, UTP) of peptidoglycan biosynthesis machinery were specifically decreased in the oxacillin-treated MRSA. These results indicate that the difference in metabolism of this isogenic pair with oxacillin treatment could be caused only by SCCmec type IV. Understanding and investigating the antibiotic response at the molecular level can, therefore, provide insight into drug resistance mechanisms and new opportunities for antibiotics development. We introduce clinical isogenic strain isolates and a multi-OMICS approach to observe a response to oxacillin of methicillin- susceptible/-resistant Staphylococcus aureus.![]()
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13
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Wang G, Li L, Wang X, Li X, Zhang Y, Yu J, Jiang J, You X, Xiong YQ. Hypericin enhances β-lactam antibiotics activity by inhibiting sarA expression in methicillin-resistant Staphylococcus aureus. Acta Pharm Sin B 2019; 9:1174-1182. [PMID: 31867163 PMCID: PMC6900551 DOI: 10.1016/j.apsb.2019.05.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 05/11/2019] [Accepted: 05/20/2019] [Indexed: 01/11/2023] Open
Abstract
Bacteremia is a life-threating syndrome often caused by methicillin-resistant Staphylococcus aureus (MRSA). Thus, there is an urgent need to develop novel approaches to successfully treat this infection. Staphylococcal accessory regulator A (SarA), a global virulence regulator, plays a critical role in pathogenesis and β-lactam antibiotic resistance in Staphylococcus aureus. Hypericin is believed to act as an antibiotic, antidepressant, antiviral and non-specific kinase inhibitor. In the current study, we investigated the impact of hypericin on β-lactam antibiotics susceptibility and mechanism(s) of its activity. We demonstrated that hypericin significantly decreased the minimum inhibitory concentrations of β-lactam antibiotics (e.g., oxacillin, cefazolin and nafcillin), biofilm formation and fibronectin binding in MRSA strain JE2. In addition, hypericin significantly reduced sarA expression, and subsequently decreased mecA, and virulence-related regulators (e.g., agr RNAⅢ) and genes (e.g., fnbA and hla) expression in the studied MRSA strain. Importantly, the in vitro synergistic effect of hypericin with β-lactam antibiotic (e.g., oxacillin) translated into in vivo therapeutic outcome in a murine MRSA bacteremia model. These findings suggest that hypericin plays an important role in abrogation of β-lactam resistance against MRSA through sarA inhibition, and may allow us to repurpose the use of β-lactam antibiotics, which are normally ineffective in the treatment of MRSA infections (e.g., oxacillin).
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Affiliation(s)
- Genzhu Wang
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Liang Li
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA 90502, USA
| | - Xiukun Wang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Xue Li
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Youwen Zhang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Jie Yu
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Jiandong Jiang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
- State Key Laboratory of Bioactive Substances and Function of Natural Medicine, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Xuefu You
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
- Corresponding authors. Tel.: +86 10 67061033, fax: +86 10 67017302 (Xuefu You); Tel.: +1 310 2223545 (Yan Q. Xiong).
| | - Yan Q. Xiong
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Corresponding authors. Tel.: +86 10 67061033, fax: +86 10 67017302 (Xuefu You); Tel.: +1 310 2223545 (Yan Q. Xiong).
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14
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Wu M, Tong X, Liu S, Wang D, Wang L, Fan H. Prevalence of methicillin-resistant Staphylococcus aureus in healthy Chinese population: A system review and meta-analysis. PLoS One 2019; 14:e0223599. [PMID: 31647842 PMCID: PMC6812772 DOI: 10.1371/journal.pone.0223599] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/24/2019] [Indexed: 02/05/2023] Open
Abstract
Objective To comprehensively determine the prevalence of MRSA in healthy Chinese population, the influencing factors of MRSA colonization and its antibiotic resistance. Methods Articles that studied prevalence or influencing factors of MRSA carriage in healthy Chinese population were retrieved from PubMed, Ovid database, three Chinese electronic databases. The pooled prevalence of MRSA, its antibiotic resistance and influencing factors were analyzed by STATA12.0. Results 37 studies were included. The pooled prevalence of MRSA was 21.2% (95% CI: 18.5%-23.9%), and the prevalence of S.aureus was 15% (95% CI: 10%-19%), with a significant heterogeneity (MRSA: I2 = 97.6%, P<0.001; S.aureus: I2 = 98.4%, P < 0.001). In subgroup analysis, the pooled prevalence of MRSA was 28% (95%CI: 10%-51%) for Livestock-related workers, 18% (95%CI: 11%-26%) for children, 20% (95%CI: 12%-29%) for healthcare workers, 7% (95%CI: 3%-13%) for community residents. The prevalence of MRSA in studies with oxacillin disk diffusion method (28%, 95%CI: 21%-35%) seemed higher than that with the mecA gene method(12%, 95%CI: 7%-19%). MRSA in studies conducted in Taiwan was more common than in Mainland China and Hong Kong. Similar results were found in meta-regression. Influencing factors for MRSA colonization were noted in seven eligible studies, they included younger age (OR: 3.54, 95% CI: 2.38–5.26; OR: 2.24, 95% CI: 1.73–2.9), attending day care centers (DCCs) (OR: 1.95, 95% CI: 1.4–2.72; OR: 1.53, 95% CI: 1.2–1.95), flu vaccination (OR:1.73, 95% CI: 1.28–2.35), using antibiotics within the past year (OR: 2.05, 95% CI:1.35–3.11), residing in northern Taiwan (OR: 1.45, 95% CI: 1.19–1.77), regular visits to health care facility (OR: 23.83, 95% CI: 2.72–209.01), household member working in health care facility (OR: 8.98, 95% CI:1.4–55.63), and contact with livestock (OR: 6.31, 95% CI: 3.44–11.57). Moreover, MRSA was found to be highly resistant to penicillin, ampicillin, erythromycin, and clindamycin, with a pooled resistance ratio of 100, 93, 88, and 75%, respectively. However, no resistance were noted to vancomycin. Conclusion The pooled prevalence of MRSA was considerably high in health Chinese population. Additionally, these strains showed extreme resistance to penicillin, ampicillin, erythromycin and clindamycin. Public MRSA protection measures and the surveillance of MRSA should be strengthened to reduce the spread of MRSA among hospitals, communities, and livestock.
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Affiliation(s)
- Man Wu
- Department of Respiratory and Critical Care Medicine, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, China
| | - Xiang Tong
- Department of Respiratory and Critical Care Medicine, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, China
| | - Sitong Liu
- Department of Respiratory and Critical Care Medicine, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, China
| | - Dongguang Wang
- Department of Respiratory and Critical Care Medicine, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, China
| | - Lei Wang
- Department of Respiratory and Critical Care Medicine, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, China
| | - Hong Fan
- Department of Respiratory and Critical Care Medicine, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, China
- * E-mail:
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15
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Lewis PO, Sevinsky RE, Patel PD, Krolikowski MR, Cluck DB. Vancomycin plus nafcillin salvage for the treatment of persistent methicillin-resistant Staphylococcus aureus bacteremia following daptomycin failure: a case report and literature review. Ther Adv Infect Dis 2018; 6:2049936118797404. [PMID: 30891239 PMCID: PMC6416679 DOI: 10.1177/2049936118797404] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 06/12/2018] [Indexed: 01/28/2023] Open
Abstract
Background: Evidence supporting beta-lactam plus vancomycin synergy for
methicillin-resistant Staphylococcus aureus (MRSA)
continues to grow. Current in vivo evidence demonstrates
that combination therapy is associated with shorter time to blood
sterilization than vancomycin monotherapy. However, this combination has not
been reported as salvage therapy for persistent MRSA bacteremia. Case report: We report a case of an 81-year-old male who was successfully treated with
vancomycin plus nafcillin after failing vancomycin monotherapy, daptomycin
monotherapy, and daptomycin plus gentamicin combination therapy. The patient
originally presented with sepsis from a suspected urinary tract infection.
Blood cultures drawn on days 1, 3, 5, 15, 19, 23, and 28 remained positive
for MRSA despite multiple antimicrobial therapy changes. On day 29, therapy
was changed to vancomycin plus nafcillin. Blood cultures drawn on day 32
remained negative. After 11 days, nafcillin was changed to
piperacillin–tazobactam due to an infected decubitus ulcer. The combination
was continued for 42 days after achieving blood sterility, 71 days after the
patient originally presented. Evidence regarding salvage therapy for
persistent bacteremia is sparse and is limited to case reports and case
series. Conclusion: This case report supports that vancomycin plus an anti-staphylococcal
beta-lactam combination should be further studied as salvage therapy for
persistent MRSA bacteremia.
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Affiliation(s)
- Paul O Lewis
- Department of Pharmacy, Johnson City Medical Center, Johnson City, TN, USA
| | - Regan E Sevinsky
- Department of Pharmacy, Massachusetts General Hospital, Boston, MA, USA
| | - Paras D Patel
- Division of Infectious Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Matthew R Krolikowski
- Division of Infectious Diseases, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - David B Cluck
- Department of Pharmacy Practice, Bill Gatton College of Pharmacy, East Tennessee State University, Johnson City, TN, USA
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16
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Gillard K, Miller HB, Blackledge MS. Tricyclic amine antidepressants suppress β-lactam resistance in methicillin-resistant Staphylococcus aureus
(MRSA) by repressing mRNA levels of key resistance genes. Chem Biol Drug Des 2018; 92:1822-1829. [DOI: 10.1111/cbdd.13361] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 06/16/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Kyra Gillard
- Department of Chemistry; High Point University; High Point North Carolina
| | - Heather B. Miller
- Department of Chemistry; High Point University; High Point North Carolina
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17
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Foster TJ. Can β-Lactam Antibiotics Be Resurrected to Combat MRSA? Trends Microbiol 2018; 27:26-38. [PMID: 30031590 DOI: 10.1016/j.tim.2018.06.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/25/2018] [Accepted: 06/22/2018] [Indexed: 01/26/2023]
Abstract
The use of β-lactam antibiotics to treat infections caused by Staphylococcus aureus has been severely compromised by the acquisition by horizontal gene transfer of a gene that encodes the β-lactam-insensitive penicillin-binding protein PBP2a. This allows methicillin-resistant S. aureus (MRSA) to proliferate in the presence of β-lactam antibiotics. Paradoxically the dependence on PBP2a for the essential transpeptidase activity in cell wall peptidoglycan biosynthesis is the 'Achilles heel' of MRSA. Compounds that disrupt the divisome, wall teichoic acid, and functional membrane microdomains act synergistically with β-lactams against MRSA. These include drugs such as statins that are widely used in human medicine. The antibiotics vancomycin and daptomycin are also synergistic with β-lactams, and combinations have been employed to treat persistent MRSA infections. An additional benefit of exposing MRSA to β-lactams could be a reduction in virulence mediated by interfering with the global regulator Agr. The mechanistic basis of synergy is discussed, and the possibility that β-lactams can be resurrected to combat MRSA infections is explored.
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Affiliation(s)
- Timothy J Foster
- Microbiology Department, Trinity College Dublin, Dublin 2, Ireland.
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18
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The Combination of Daptomycin and Fosfomycin Has Synergistic, Potent, and Rapid Bactericidal Activity against Methicillin-Resistant Staphylococcus aureus in a Rabbit Model of Experimental Endocarditis. Antimicrob Agents Chemother 2018; 62:AAC.02633-17. [PMID: 29610194 DOI: 10.1128/aac.02633-17] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 03/26/2018] [Indexed: 11/20/2022] Open
Abstract
We investigated whether the addition of fosfomycin or cloxacillin to daptomycin provides better outcomes in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) experimental aortic endocarditis in rabbits. Five MRSA strains were used to perform in vitro time-kill studies using standard (106) and high (108) inocula. Combined therapy was compared to daptomycin monotherapy treatment in the MRSA experimental endocarditis model. A human-like pharmacokinetics model was applied, and the equivalents of cloxacillin at 2 g/4 h, fosfomycin at 2 g/6 h, and daptomycin at 6 to 10 mg/kg/day were administered intravenously. A combination of daptomycin and either fosfomycin or cloxacillin was synergistic in the five strains tested at both inocula. A bactericidal effect was detected in four of five strains tested with both combinations. The MRSA-277 strain (vancomycin MIC, 2 μg/ml) was used for the experimental endocarditis model. Daptomycin plus fosfomycin significantly improved the efficacy of daptomycin monotherapy at 6 mg/kg/day in terms of both the proportion of sterile vegetations (100% versus 72%, P = 0.046) and the decrease in the density of bacteria within the vegetations (P = 0.025). Daptomycin plus fosfomycin was as effective as daptomycin monotherapy at 10 mg/kg/day (100% versus 93%, P = 1.00) and had activity similar to that of daptomycin plus cloxacillin when daptomycin was administered at 6 mg/kg/day (100% versus 88%, P = 0.48). Daptomycin nonsusceptibility was not detected in any of the isolates recovered from vegetations. In conclusion, for the treatment of MRSA experimental endocarditis, the combination of daptomycin plus fosfomycin showed synergistic and bactericidal activity.
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Viedma E, Pérez-Montarelo D, Villa J, Muñoz-Gallego I, Larrosa N, Fernández-Hidalgo N, Gavaldà J, Almirante B, Chaves F. Sub-inhibitory concentrations of oxacillin modify the expression of agr locus in Staphylococcus aureus clinical strains belonging to different clonal complexes. BMC Infect Dis 2018; 18:177. [PMID: 29661157 PMCID: PMC5902860 DOI: 10.1186/s12879-018-3088-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 04/05/2018] [Indexed: 02/08/2023] Open
Abstract
Background The ability of Staphylococcus aureus to invade tissues and cause an infectious disease is the result of a multi-factorial process supported by the huge number of virulence factors inherent to this microorganism tightly regulated by the accessory gene regulator (agr). During antimicrobial therapy bacteria may be exposed to sub-inhibitory concentrations (subMICs) of antibiotics that may trigger transcriptional changes that may have an impact on the pathogenesis of infection. The objective of this study was to investigate the effect of oxacillin sub-MICs on agr system expression as the key component in the regulation of virulence in methicillin-susceptible (MSSA) and -resistant S. aureus (MRSA) strains. Furthermore, we studied the genetic basis of the agr locus and their potential association with the expression levels. Methods We have examined the expression of RNAIII and agrA mRNA as biomarkers for agr expression in the presence and absence of oxacillin subMICs in 10 MSSA and 4 MRSA clinical strains belonging to 5 clonal complexes (CC45-agrI, CC8-agrI, CC5-agrII, CC15-agrII and CC30-agrIII) causing endovascular complications. The DNA sequences of agr locus were obtained by whole genome sequencing. Results Our results revealed that exposure to subMICs of oxacillin had an impact on agr locus expression modifying the relative levels of expression with increases in 11 strains and with decreases in 3 strains. Thereby, the exposure to subMICs of oxacillin resulted in higher levels of expression of agr in CC15 and CC45 and lower levels in CC30. We also observed the presence of mutations in agrC and agrA in 13/14 strains with similar mutation profiles among strains within individual CCs except for strains of CC5. Although, agr expression levels differed among strains within CCs, the presence of these mutations was associated with differences in agr expression levels in most cases. Conclusions Changes in agr expression induced by exposure to oxacillin subMICs should be considered because they could lead to changes in the virulence modulation and have an adverse effect on the course of infection, especially in certain clonal complexes. Electronic supplementary material The online version of this article (10.1186/s12879-018-3088-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Esther Viedma
- Department of Microbiology, Hospital Universitario 12 de Octubre, Madrid, Spain.
| | | | - Jennifer Villa
- Department of Microbiology, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Irene Muñoz-Gallego
- Department of Microbiology, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Nieves Larrosa
- Department of Infectious Diseases, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | | | - Joan Gavaldà
- Department of Infectious Diseases, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Benito Almirante
- Department of Infectious Diseases, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Fernando Chaves
- Department of Microbiology, Hospital Universitario 12 de Octubre, Madrid, Spain
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Targeting Virulence in Staphylococcus aureus by Chemical Inhibition of the Accessory Gene Regulator System In Vivo. mSphere 2018; 3:mSphere00500-17. [PMID: 29359191 PMCID: PMC5770542 DOI: 10.1128/msphere.00500-17] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) presents one of the most serious health concerns worldwide. The WHO labeled it as a “high-priority” pathogen in 2017, also citing the more recently emerged vancomycin-intermediate and -resistant strains. Methicillin-resistant Staphylococcus aureus (MRSA) presents one of the most serious health concerns worldwide. The WHO labeled it as a “high-priority” pathogen in 2017, also citing the more recently emerged vancomycin-intermediate and -resistant strains. With the spread of antibiotic resistance due in large part to the selective pressure exerted by conventional antibiotics, the use of antivirulence strategies has been recurrently proposed as a promising therapeutic approach. In MRSA, virulence is chiefly controlled by quorum sensing (QS); inhibitors of QS are called quorum quenchers (QQ). In S. aureus, the majority of QS components are coded for by the accessory gene regulator (Agr) system. Although much work has been done to develop QQs against MRSA, only a few studies have progressed to in vivo models. Those studies include both prophylactic and curative models of infection as well as combination treatments with antibiotic. For most, high efficacy is seen at attenuating MRSA virulence and pathogenicity, with some studies showing effects such as synergy with antibiotics and antibiotic resensitization. This minireview aims to summarize and derive conclusions from the literature on the in vivo efficacy of QQ agents in MRSA infection models. In vitro data are also summarized to provide sufficient background on the hits discussed. On the whole, the reported in vivo effects of the reviewed QQs against MRSA represent positive progress at this early stage in drug development. Follow-up studies that thoroughly examine in vitro and in vivo activity are needed to propel the field forward and set the stage for lead optimization.
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Casapao AM, Jacobs DM, Bowers DR, Beyda ND, Dilworth TJ. Early Administration of Adjuvant β-Lactam Therapy in Combination with Vancomycin among Patients with Methicillin-ResistantStaphylococcus aureusBloodstream Infection: A Retrospective, Multicenter Analysis. Pharmacotherapy 2017; 37:1347-1356. [DOI: 10.1002/phar.2034] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
| | - David M. Jacobs
- University at Buffalo School of Pharmacy and Pharmaceutical Sciences; Buffalo New York
| | | | | | - Thomas J. Dilworth
- Department of Pharmacy; Wheaton Franciscan Healthcare - St. Francis Hospital; Milwaukee Wisconsin
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Bal AM, David MZ, Garau J, Gottlieb T, Mazzei T, Scaglione F, Tattevin P, Gould IM. Future trends in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infection: An in-depth review of newer antibiotics active against an enduring pathogen. J Glob Antimicrob Resist 2017; 10:295-303. [PMID: 28732783 DOI: 10.1016/j.jgar.2017.05.019] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/20/2017] [Accepted: 05/24/2017] [Indexed: 10/19/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a major public health problem. Vancomycin and teicoplanin have been in clinical use for several decades but their drawbacks are well described. In the last 10 years, several antibiotics have been made available for clinical use. Daptomycin and linezolid have been extensively used during this period. Other agents such as ceftaroline, ceftobiprole, dalbavancin, oritavancin, tedizolid and telavancin have been approved by regulatory agencies since 2009. Many others, such as the newer tetracyclines, fluoroquinolones, oxazolidinones and pleuromutilins, are in various stages of development. In addition, an ongoing multicentre trial is investigating the role of combination of vancomycin or daptomycin with β-lactam antibiotics. This review discusses the role of the newer antibiotics, reflecting the views of the 6th MRSA Consensus Conference meeting of the International Society of Chemotherapy MRSA Working Group that took place in 2016.
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Affiliation(s)
- A M Bal
- Department of Microbiology, University Hospital Crosshouse, Kilmarnock KA2 0BE, UK.
| | - M Z David
- Departments of Medicine, Paediatrics, and Public Health Sciences, University of Chicago, Chicago, IL 60637, USA
| | - J Garau
- Department of Medicine, Hospital Universitari Mútua de Terrassa, Plaza Dr Robert 5, Barcelona 08221, Spain
| | - T Gottlieb
- Department of Microbiology and Infectious Diseases, Concord Hospital, Sydney, NSW 2139, Australia
| | - T Mazzei
- Department of Health Sciences, Clinical Pharmacology and Oncology Section, University of Firenze, Firenze, Italy
| | - F Scaglione
- Department of Oncology and Onco-Haematology, University of Milan, Via Vanvitelli 32, 20129 Milan, Italy
| | - P Tattevin
- Infectious Diseases and Intensive Care Unit, Pontchaillou University Hospital, 35033 Rennes, France
| | - I M Gould
- Department of Microbiology, Aberdeen Royal Infirmary, Aberdeen AB25 2ZN, UK
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Bayer AS, Xiong YQ. Redeploying β-Lactams Against Staphylococcus aureus: Repurposing With a Purpose. J Infect Dis 2016; 215:11-13. [PMID: 28077581 DOI: 10.1093/infdis/jiw464] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 09/26/2016] [Indexed: 12/14/2022] Open
Affiliation(s)
- Arnold S Bayer
- LA Biomedical Research Institute at Harbor-UCLA, Torrance
| | - Yan Q Xiong
- David Geffen School of Medicine at UCLA, Los Angeles, California
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