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Holden JK, Kang S, Beasley FC, Cinelli MA, Li H, Roy SG, Dejam D, Edinger AL, Nizet V, Silverman RB, Poulos TL. Nitric Oxide Synthase as a Target for Methicillin-Resistant Staphylococcus aureus. ACTA ACUST UNITED AC 2016; 22:785-92. [PMID: 26091171 DOI: 10.1016/j.chembiol.2015.05.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 04/20/2015] [Accepted: 05/17/2015] [Indexed: 02/04/2023]
Abstract
Bacterial infections associated with methicillin-resistant Staphylococcus aureus (MRSA) are a major economic burden to hospitals, and confer high rates of morbidity and mortality among those infected. Exploitation of novel therapeutic targets is thus necessary to combat this dangerous pathogen. Here, we report on the identification and characterization, including crystal structures, of two nitric oxide synthase (NOS) inhibitors that function as antimicrobials against MRSA. These data provide the first evidence that bacterial NOS (bNOS) inhibitors can work synergistically with oxidative stress to enhance MRSA killing. Crystal structures show that each inhibitor contacts an active site Ile residue in bNOS that is Val in the mammalian NOS isoforms. Mutagenesis studies show that the additional nonpolar contacts provided by the Ile in bNOS contribute to tighter binding toward the bacterial enzyme.
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Affiliation(s)
- Jeffrey K Holden
- Departments of Molecular Biology and Biochemistry, Pharmaceutical Sciences, and Chemistry, University of California, Irvine, CA 92697-3900, USA
| | - Soosung Kang
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208-3113, USA
| | - Federico C Beasley
- Departments of Pediatrics and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA 92093, USA
| | - Maris A Cinelli
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208-3113, USA
| | - Huiying Li
- Departments of Molecular Biology and Biochemistry, Pharmaceutical Sciences, and Chemistry, University of California, Irvine, CA 92697-3900, USA
| | - Saurabh G Roy
- Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, USA
| | - Dillon Dejam
- Departments of Molecular Biology and Biochemistry, Pharmaceutical Sciences, and Chemistry, University of California, Irvine, CA 92697-3900, USA
| | - Aimee L Edinger
- Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, USA
| | - Victor Nizet
- Departments of Pediatrics and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA 92093, USA
| | - Richard B Silverman
- Departments of Chemistry and Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL 60208-3113, USA.
| | - Thomas L Poulos
- Departments of Molecular Biology and Biochemistry, Pharmaceutical Sciences, and Chemistry, University of California, Irvine, CA 92697-3900, USA.
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302
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Akinpelu DA, Odewade JO, Aiyegoro OA, Ashafa AOT, Akinpelu OF, Agunbiade MO. Biocidal effects of stem bark extract of Chrysophyllum albidium G. Don on vancomycin-resistant Staphylococcus aureus. Altern Ther Health Med 2016; 16:105. [PMID: 27004526 PMCID: PMC4802705 DOI: 10.1186/s12906-016-1080-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 03/09/2016] [Indexed: 12/03/2022]
Abstract
Background Staphylococcus aureus causes variety of infections in humans and animals worldwide and predominates in surgical wound infections. This study assessed the antimicrobial potential of the stem bark extract of Chrysophyllum albidum against an array of vancomycin resistant Staphylococcus aureus (VRSA) isolated from clinical samples. Methods The methanolic crude extract of the plant was preliminary screened for the presence of phytochemicals; after then, the extract was partitioned into n-hexane, chloroform, ethyl acetate and butanol fractions. A range of concentrations of the plant extract fractions was prepared to assess its antimicrobial potency; the minimum inhibitory concentrations (MICs); the minimum bactericidal concentrations (MBCs); the rate of killing; the potassium ion leakage potential and nucleotides leakage ability against the VRSAs. Results The phytochemical screening revealed the presence of tannins, alkaloids, flavonoids, saponins, steroids, reducing sugars and terpenoids as major phytoconstituents resident in the crude plant extract. The two active fractions (n-hexane and butanol) at a concentration of 10 mg/ml exhibited antibacterial activities with the MIC and MBC values for the fractions ranged between 0.63–10 mg/ml and 1.25–10 mg/ml respectively. The time kill assay revealed that the antibacterial action of the two fractions are time and concentration dependent; the n-hexane and butanol fractions achieved 100 % kill on the test isolates at a concentration of 3 × MIC and 2 × MIC respectively after 120 min of reaction time. Varying amount of potassium ions as well as nucleotides were leaked from the test cells by n-hexane and butanol fractions. Conclusions This study has established the possibility of developing antimicrobial agents of natural origin to manage possible infection from vancomycin resistant Staphylococcus aureus that are now developing multi-resistance against many antibiotics.
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303
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Pereira F, Madureira AM, Sancha S, Mulhovo S, Luo X, Duarte A, Ferreira MJU. Cleistochlamys kirkii chemical constituents: Antibacterial activity and synergistic effects against resistant Staphylococcus aureus strains. JOURNAL OF ETHNOPHARMACOLOGY 2016; 178:180-187. [PMID: 26674158 DOI: 10.1016/j.jep.2015.12.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 11/28/2015] [Accepted: 12/06/2015] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Cleistochlamys kirkii (Benth) Oliv., (Annonaceae) is a medicinal plant traditionally used in Mozambique to treat infectious diseases. AIMS OF THE STUDY To find antibacterial lead compounds from C. kirkii and provide scientific validation for its use in traditional medicine. MATERIALS AND METHODS Through bioassay-guided fractionation, nine compounds (1-9), with different scaffolds, were isolated from the methanol extract of C. kirkii whose structures were identified by spectroscopic methods. Compounds 1-9 were evaluated for their in vitro antibacterial activity against a panel of eight Gram-positive, including five drug-resistant strains of Staphylococcus aureus, vancomycin-resistant Enterococcus faecalis, and two Gram-negative bacteria strains. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. A chemosensitization assay, using the checkerboard method, was also performed in order to evaluate the type of interaction of compounds with antibiotics/compounds against two S. aureus resistant strains (ATCC 9144 and CIP 106760) and a susceptible strain (ATCC 6538). RESULTS Dichamanetin (3), a rare C-benzylated flavanone, was very active against all the Gram-positive strains tested, displaying MIC values in the range of 1-7.5 μg/mL. The C-benzylated flavanones chamanetin (1), isochamanetin (2), and the α,β-unsaturated lactone (-)-cleistenolide (6) also showed relevant antibacterial activity against some of the Gram-positive strains assayed. Compounds 4, 5, and 7-9 have shown no significant activity at the concentration ranges tested. In the combination with antibiotics, polycarpol (8) (MIC 125 μg/mL) showed a strong synergistic effect against the methicillin-resistant S. aureus ATCC 9144. When combined with oxacillin (MIC 125 μg/mL), compound 8 reduced the MIC to 1.5 μg/mL (FICI=0.11). Similarly, it reduced the MIC of amoxicillin (MIC 250 μg/mL) to 7.5 μg/mL (FICI=0.18). Synergy was also obtained when this compound was combined with both β-lactam antibiotics (FICI=0.30) and with vancomycin (FICI=0.24) against vancomycin-intermediate S. aureus (VISA) CIP 106760. Remarkable, compound 8 was also able to reduce synergistically the MIC value of dichamanetin (3) (FICI=0.18) against this strain. CONCLUSIONS These results suggested that C. kirkii constituents may be valuable as a leads for restoring antibiotic activity against resistant S. aureus strains.
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Affiliation(s)
- Filipe Pereira
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal
| | - Ana Margarida Madureira
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal
| | - Shirley Sancha
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal
| | - Silva Mulhovo
- Centro de Estudos Moçambicanos e de Etnociências (CEMEC), Faculdade de Ciências Naturais e Matemática, Universidade Pedagógica, Campus de Lhanguene, Av. de Moçambique, 21402161 Maputo, Mozambique
| | - Xuan Luo
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal
| | - Aida Duarte
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal
| | - Maria-José U Ferreira
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal.
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Gustafson CT, Boakye-Agyeman F, Brinkman CL, Reid JM, Patel R, Bajzer Z, Dadsetan M, Yaszemski MJ. Controlled Delivery of Vancomycin via Charged Hydrogels. PLoS One 2016; 11:e0146401. [PMID: 26760034 PMCID: PMC4711919 DOI: 10.1371/journal.pone.0146401] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 12/16/2015] [Indexed: 01/08/2023] Open
Abstract
Surgical site infection (SSI) remains a significant risk for any clean orthopedic surgical procedure. Complications resulting from an SSI often require a second surgery and lengthen patient recovery time. The efficacy of antimicrobial agents delivered to combat SSI is diminished by systemic toxicity, bacterial resistance, and patient compliance to dosing schedules. We submit that development of localized, controlled release formulations for antimicrobial compounds would improve the effectiveness of prophylactic surgical wound antibiotic treatment while decreasing systemic side effects. Our research group developed and characterized oligo(poly(ethylene glycol)fumarate) / sodium methacrylate (OPF/SMA) charged copolymers as biocompatible hydrogel matrices. Here, we report the engineering of this copolymer for use as an antibiotic delivery vehicle in surgical applications. We demonstrate that these hydrogels can be efficiently loaded with vancomycin (over 500 μg drug per mg hydrogel) and this loading mechanism is both time- and charge-dependent. Vancomycin release kinetics are shown to be dependent on copolymer negative charge. In the first 6 hours, we achieved as low as 33.7% release. In the first 24 hours, under 80% of total loaded drug was released. Further, vancomycin release from this system can be extended past four days. Finally, we show that the antimicrobial activity of released vancomycin is equivalent to stock vancomycin in inhibiting the growth of colonies of a clinically derived strain of methicillin-resistant Staphylococcus aureus. In summary, our work demonstrates that OPF/SMA hydrogels are appropriate candidates to deliver local antibiotic therapy for prophylaxis of surgical site infection.
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Affiliation(s)
- Carl T. Gustafson
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Graduate School, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota 55902, United States of America
- * E-mail:
| | - Felix Boakye-Agyeman
- Pharmacometrics Center, Duke Clinical Research Institute (DCRI), Durham, North Carolina 27705, United States of America
| | - Cassandra L. Brinkman
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic Infectious Disease Research Laboratory, Mayo Clinic, Rochester, Minnesota 55902, United States of America
| | - Joel M. Reid
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Graduate School, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota 55902, United States of America
| | - Robin Patel
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic Infectious Disease Research Laboratory, Mayo Clinic, Rochester, Minnesota 55902, United States of America
| | - Zeljko Bajzer
- Division of Biomathematics, Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota 55902, United States of America
- Division of Biomathematics, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota 55902, United States of America
| | - Mahrokh Dadsetan
- Division of Orthopaedic Research, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota 55902, United States of America
| | - Michael J. Yaszemski
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Graduate School, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota 55902, United States of America
- Division of Orthopaedic Research, Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota 55902, United States of America
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305
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Antibacterial Properties of Tebipenem Pivoxil Tablet, a New Oral Carbapenem Preparation against a Variety of Pathogenic Bacteria in Vitro and in Vivo. Molecules 2016; 21:62. [PMID: 26751436 PMCID: PMC6273992 DOI: 10.3390/molecules21010062] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 12/25/2015] [Accepted: 12/31/2015] [Indexed: 01/22/2023] Open
Abstract
Aims: To systemically investigate the in vitro and in vivo antibacterial properties of tebipenem pivoxil tablet. In addition, acute toxicity of this preparation was also studied. Methods: In vitro, minimum inhibitory concentration (MIC) or minimal inhibitory concentration (MBC) were determined by using the serial 2-fold broth or agar dilution methods. Further, cumulative MIC inhibition curves were then made to assess the antibacterial effects of the drug at various concentrations. In vivo, minimum lethal dose (MLD) in combination with maximum tolerance dose (MTD) was used to measure the acute toxicity of the tebipenem pivoxil tablet in mice. After that, sepsis mouse models challenged with Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, respectively, were established to evaluate the anti-infective effect of this preparation. Results: The MIC90 values of tebipenem pivoxil against Gram-positive bacteria such as methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), methicillin-sensitive Staphylococcus epidermidis (MSSE), methicillin-resistant Staphylococcus epidermidis (MRSE), Pyogenic streptococcus, and Enterococcus faecalis were ≤0.125, 16, 0.5, 8, ≤0.125, and 32 μg/mL, respectively. Correspondingly, the MIC90 values of tebipenem pivoxil against Escherichia coli, Klebsiellapneumoniae, Enterobacter aerogenes, Haemophilus influenzae, Pseudomonas aeruginosa, and Acinetobacter baumannii were 1, 0.5, ≤0.125, 0.25, 64, 64 μg/mL, respectively. The MBC values of tebipenem pivoxil against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae were 0.016–2, 0.063–32, 0.031–32 μg/mL, respectively. The acute toxicity study showed that the MLD of the tebipenem pivoxil tablet was 4.00 g/kg and the MTD was 3.40 g/kg in mice. In all the sepsis mouse models, the simultaneous administration of the tebipenem pivoxil tablets significantly reduced mortality of the sepsis-model mice as compared with the control. Furthermore, the survival rate in the tebipenem pivoxil tablet group was remarkably higher than that in the meropenem group in all the sepsis mouse models tested. In the sepsis model challenged with Staphylococcus aureus ATCC29213, Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27853, and Pseudomonas aeruginosa clinical strain, respectively, tebipenem pivoxil tablet (100 mg/kg) displayed a better protective effect than tebipenem pivoxil granules (100 mg/kg). Conclusions: In summary, tebipenem pivoxil displays an excellent antibacterial activity against a variety of pathogenic bacteria in vitro. Importantly, tebipenem pivoxil tablet significantly protects the sepsis mice challenged with various pathogenic bacteria, which may provide a potential approach to treating bacterial sepsis in clinic.
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306
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Targeting bacterial topoisomerase I to meet the challenge of finding new antibiotics. Future Med Chem 2016; 7:459-71. [PMID: 25875873 DOI: 10.4155/fmc.14.157] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Resistance of bacterial pathogens to current antibiotics has grown to be an urgent crisis. Approaches to overcome this challenge include identification of novel targets for discovery of new antibiotics. Bacterial topoisomerase I is present in all bacterial pathogens as a potential target for bactericidal topoisomerase poison inhibitors. Recent efforts have identified inhibitors of bacterial topoisomerase I with antibacterial activity. Additional research on the mode of action and binding site of these inhibitors would provide further validation of the target and establish that bacterial topoisomerase I is druggable. Bacterial topoisomerase I is a potentially high value target for discovery of new antibiotics. Demonstration of topoisomerase I as the cellular target of an antibacterial compound would provide proof-of-concept validation.
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307
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Medina E, Pieper DH. Tackling Threats and Future Problems of Multidrug-Resistant Bacteria. Curr Top Microbiol Immunol 2016; 398:3-33. [PMID: 27406189 DOI: 10.1007/82_2016_492] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
With the advent of the antibiotic era, the overuse and inappropriate consumption and application of antibiotics have driven the rapid emergence of multidrug-resistant pathogens. Antimicrobial resistance increases the morbidity, mortality, length of hospitalization and healthcare costs. Among Gram-positive bacteria, Staphylococcus aureus (MRSA) and multidrug-resistant (MDR) Mycobacterium tuberculosis, and among the Gram-negative bacteria, extended-spectrum beta-lactamase (ESBLs)-producing bacteria have become a major global healthcare problem in the 21st century. The pressure to use antibiotics guarantees that the spread and prevalence of these as well as of future emerging multidrug-resistant pathogens will be a persistent phenomenon. The unfeasibility of reversing antimicrobial resistance back towards susceptibility and the critical need to treat bacterial infection in modern medicine have burdened researchers and pharmaceutical companies to develop new antimicrobials effective against these difficult-to-treat multidrug-resistant pathogens. However, it can be anticipated that antibiotic resistance will continue to develop more rapidly than new agents to treat these infections become available and a better understanding of the molecular, evolutionary and ecological mechanisms governing the spread of antibiotic resistance is needed. The only way to curb the current crisis of antimicrobial resistance will be to develop entirely novel strategies to fight these pathogens such as combining antimicrobial drugs with other agents that counteract and obstruct the antibiotic resistant mechanisms expressed by the pathogen. Furthermore, as many antibiotics are often inappropriately prescribed, a more personalized approach based on precise diagnosis tools will ensure that proper treatments can be promptly applied leading to more targeted and effective therapies. However, in more general terms, also the overall use and release of antibiotics in the environment needs to be better controlled.
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Affiliation(s)
- Eva Medina
- Infection Immunology Research Group, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany.
| | - Dietmar Helmut Pieper
- Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
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308
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The Staphylococcus aureus Chaperone PrsA Is a New Auxiliary Factor of Oxacillin Resistance Affecting Penicillin-Binding Protein 2A. Antimicrob Agents Chemother 2015; 60:1656-66. [PMID: 26711778 DOI: 10.1128/aac.02333-15] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 12/15/2015] [Indexed: 12/17/2022] Open
Abstract
Expression of the methicillin-resistant S. aureus (MRSA) phenotype results from the expression of the extra penicillin-binding protein 2A (PBP2A), which is encoded by mecA and acquired horizontally on part of the SCCmec cassette. PBP2A can catalyze dd-transpeptidation of peptidoglycan (PG) because of its low affinity for β-lactam antibiotics and can functionally cooperate with the PBP2 transglycosylase in the biosynthesis of PG. Here, we focus upon the role of the membrane-bound PrsA foldase protein as a regulator of β-lactam resistance expression. Deletion of prsA altered oxacillin resistance in three different SCCmec backgrounds and, more importantly, caused a decrease in PBP2A membrane amounts without affecting mecA mRNA levels. The N- and C-terminal domains of PrsA were found to be critical features for PBP2A protein membrane levels and oxacillin resistance. We propose that PrsA has a role in posttranscriptional maturation of PBP2A, possibly in the export and/or folding of newly synthesized PBP2A. This additional level of control in the expression of the mecA-dependent MRSA phenotype constitutes an opportunity to expand the strategies to design anti-infective agents.
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309
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Klinker KP, Borgert SJ. Beyond Vancomycin: The Tail of the Lipoglycopeptides. Clin Ther 2015; 37:2619-36. [DOI: 10.1016/j.clinthera.2015.11.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 11/09/2015] [Accepted: 11/13/2015] [Indexed: 12/18/2022]
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310
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Van Bambeke F. Lipoglycopeptide Antibacterial Agents in Gram-Positive Infections: A Comparative Review. Drugs 2015; 75:2073-95. [DOI: 10.1007/s40265-015-0505-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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311
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Lawing CR, Lin FC, Dahners LE. Local Injection of Aminoglycosides for Prophylaxis Against Infection in Open Fractures. J Bone Joint Surg Am 2015; 97:1844-51. [PMID: 26582614 PMCID: PMC4642229 DOI: 10.2106/jbjs.o.00072] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND The purpose of this study was to determine the efficacy of local wound cavity injections of aqueous aminoglycosides (gentamicin and tobramycin), in conjunction with systemic antibiotics, to lower the prevalence of infection in patients with open fractures. METHODS Three hundred and fifty-one open fractures were identified by Current Procedural Terminology codes 11011 and 11012. Data on patient demographic characteristics, injury characteristics, infection, and fracture union were obtained from the electronic medical records. Patients in the control group (183 fractures) received systemic antibiotics only. Patients in the intervention group (168 fractures) received, in addition to systemic antibiotics, a locally administered aminoglycoside (2 mg/mL) at the time of the index surgical procedure. At the discretion of the attending surgeon, some wounds also received postoperative irrigations of aqueous aminoglycoside (n = 34). For wounds that could not be closed and wounds that received postoperative irrigations, negative pressure dressings were used. RESULTS The deep and superficial infection rate in the control group was 19.7% (thirty-six of 183 fractures), but it was significantly lower (p = 0.010) in the intervention group at 9.5% (sixteen of 168 fractures). When comparing only the deep infections, the infection rate in the control group was 14.2% (twenty-six of 183 fractures) compared with 6.0% (ten of 168 fractures) in the intervention group (p = 0.011). After multivariate analysis to adjust for possible confounding factors, the administration of local antibiotics was found to be an independent predictor of lower infection rates in both deep and superficial infections (odds ratio, 2.6 [95% confidence interval, 1.2 to 5.6]; p = 0.015) and deep infections only (odds ratio, 3.0 [95% confidence interval, 1.1 to 8.5]; p = 0.034). The use of local antibiotics did not have an impact on nonunion rate (p = 0.881), with a type-I error rate of α = 0.05 and 0.8 power. CONCLUSIONS This study suggests that local aqueous aminoglycoside administration as an adjunct to systemic antibiotics may be effective in lowering infection rates in open fractures; further research with higher-level research designs are needed.
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Affiliation(s)
- Cheryl Reese Lawing
- Department of Orthopaedics, The University of North Carolina at Chapel Hill, Campus Box 7055, Chapel Hill, NC 27599. E-mail address for C.R. Lawing: . E-mail address for L.E. Dahners:
| | - Feng-Chang Lin
- Department of Biostatistics, The University of North Carolina at Chapel Hill, 160 North Medical Drive, Brinkhous-Bullitt Building, 2nd Floor, Campus Box 7064, Chapel Hill, NC 27599
| | - Laurence E. Dahners
- Department of Orthopaedics, The University of North Carolina at Chapel Hill, Campus Box 7055, Chapel Hill, NC 27599. E-mail address for C.R. Lawing: . E-mail address for L.E. Dahners:
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312
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Vuong C, Yeh AJ, Cheung GYC, Otto M. Investigational drugs to treat methicillin-resistant Staphylococcus aureus. Expert Opin Investig Drugs 2015; 25:73-93. [PMID: 26536498 DOI: 10.1517/13543784.2016.1109077] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
INTRODUCTION Staphylococcus aureus remains one of the leading causes of morbidity and mortality worldwide. This is to a large extent due to antibiotic-resistant strains, in particular methicillin-resistant S. aureus (MRSA). While the toll of invasive MRSA infections appears to decrease in U.S. hospitals, the rate of community-associated MRSA infections remains constant and there is a surge of MRSA in many other countries, a situation that calls for continuing if not increased efforts to find novel strategies to combat MRSA infections. AREAS COVERED This review provides an overview of current investigational drugs and therapeutic antibodies against S. aureus in early clinical development (up to phase II clinical development). It includes a short description of the mechanism of action and a presentation of microbiological and clinical data. EXPERT OPINION Increased recent antibiotic development efforts and results from pathogenesis research have led to several new antibiotics and therapies, such as anti-virulence drugs, as well as a more informed selection of targets for vaccination efforts against MRSA. This developing portfolio of novel anti-staphylococcal drugs will hopefully provide us with additional and more efficient ways to combat MRSA infections in the near future and prevent us from running out of treatment options, even if new resistances arise.
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Affiliation(s)
- Cuong Vuong
- a Principal Scientist/Laboratory Head, Bacteriology , AiCuris GmbH & Co. KG, Friedrich-Ebert-Str. 475/Geb. 302, 42117 Wuppertal , Germany
| | - Anthony J Yeh
- b Post-baccalaureate IRTA, Laboratory of Bacteriology , National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bldg. 33, 1W10, 9000 Rockville Pike, Bethesda , MD 20892 , USA
| | - Gordon Y C Cheung
- c Staff Scientist, National Institute of Allergy and Infectious Diseases , National Institutes of Health, Laboratory of Bacteriology , Bldg. 33, 1W10, 9000 Rockville Pike, Bethesda , MD 20892 , USA
| | - Michael Otto
- d Senior Investigator, National Institute of Allergy and Infectious Diseases , National Institutes of Health, Laboratory of Bacteriology , Bldg. 33, 1W10, 9000 Rockville Pike, Bethesda , MD 20892 , USA
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313
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Yong AL, Ooh KF, Ong HC, Chai TT, Wong FC. Investigation of antibacterial mechanism and identification of bacterial protein targets mediated by antibacterial medicinal plant extracts. Food Chem 2015; 186:32-6. [DOI: 10.1016/j.foodchem.2014.11.103] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 11/14/2014] [Accepted: 11/18/2014] [Indexed: 12/25/2022]
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314
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Abstract
Daptomycin (DAP) is a cyclic lipopeptide with in vitro activity against a variety of Gram-positive pathogens, including multidrug-resistant organisms. Since its introduction into clinical practice in 2003, DAP has become an important key frontline antibiotic for severe or deep-seated infections caused by Gram-positive organisms. Unfortunately, DAP resistance (DAP-R) has been extensively documented in clinically important organisms such as Staphylococcus aureus, Enterococcus spp., and Streptococcus spp. Studies on the mechanisms of DAP-R in Bacillus subtilis and other Gram-positive bacteria indicate that the genetic pathways of DAP-R are diverse and complex. However, a common phenomenon emerging from these mechanistic studies is that DAP-R is associated with important adaptive changes in cell wall and cell membrane homeostasis with critical changes in cell physiology. Findings related to these adaptive changes have provided novel insights into the genetics and molecular mechanisms of bacterial cell envelope stress response and the manner in which Gram-positive bacteria cope with the antimicrobial peptide attack and protect vital structures of the cell envelope, such as the cell membrane. In this review, we will examine the most recent findings related to the molecular mechanisms of resistance to DAP in relevant Gram-positive pathogens and discuss the clinical implications for therapy against these important bacteria.
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Affiliation(s)
- Truc T Tran
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School at Houston, Houston, Texas.,International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia
| | - Jose M Munita
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School at Houston, Houston, Texas.,International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia.,Clinica Alemana de Santiago, Universidad del Desarrollo, Santiago, Chile
| | - Cesar A Arias
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School at Houston, Houston, Texas.,International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia.,Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, Houston, Texas.,Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogota, Colombia
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315
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O'Brien FG, Yui Eto K, Murphy RJT, Fairhurst HM, Coombs GW, Grubb WB, Ramsay JP. Origin-of-transfer sequences facilitate mobilisation of non-conjugative antimicrobial-resistance plasmids in Staphylococcus aureus. Nucleic Acids Res 2015; 43:7971-83. [PMID: 26243776 PMCID: PMC4652767 DOI: 10.1093/nar/gkv755] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 07/14/2015] [Indexed: 11/17/2022] Open
Abstract
Staphylococcus aureus is a common cause of hospital, community and livestock-associated infections and is increasingly resistant to multiple antimicrobials. A significant proportion of antimicrobial-resistance genes are plasmid-borne, but only a minority of S. aureus plasmids encode proteins required for conjugative transfer or Mob relaxase proteins required for mobilisation. The pWBG749 family of S. aureus conjugative plasmids can facilitate the horizontal transfer of diverse antimicrobial-resistance plasmids that lack Mob genes. Here we reveal that these mobilisable plasmids carry copies of the pWBG749 origin-of-transfer (oriT) sequence and that these oriT sequences facilitate mobilisation by pWBG749. Sequences resembling the pWBG749 oriT were identified on half of all sequenced S. aureus plasmids, including the most prevalent large antimicrobial-resistance/virulence-gene plasmids, pIB485, pMW2 and pUSA300HOUMR. oriT sequences formed five subfamilies with distinct inverted-repeat-2 (IR2) sequences. pWBG749-family plasmids encoding each IR2 were identified and pWBG749 mobilisation was found to be specific for plasmids carrying matching IR2 sequences. Specificity of mobilisation was conferred by a putative ribbon-helix-helix-protein gene smpO. Several plasmids carried 2–3 oriT variants and pWBG749-mediated recombination occurred between distinct oriT sites during mobilisation. These observations suggest this relaxase-in trans mechanism of mobilisation by pWBG749-family plasmids is a common mechanism of plasmid dissemination in S. aureus.
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Affiliation(s)
- Frances G O'Brien
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, School of Veterinary Sciences and Life Sciences, Murdoch University and School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia
| | - Karina Yui Eto
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia
| | - Riley J T Murphy
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia
| | - Heather M Fairhurst
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia
| | - Geoffrey W Coombs
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, School of Veterinary Sciences and Life Sciences, Murdoch University and School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia PathWest Laboratory Medicine, Fiona Stanley Hospital, Perth, Western Australia, Australia
| | - Warren B Grubb
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, School of Veterinary Sciences and Life Sciences, Murdoch University and School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia
| | - Joshua P Ramsay
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, School of Veterinary Sciences and Life Sciences, Murdoch University and School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia
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316
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Senna JPM, Teixeira MDGM, Santiago MDA, Batoréu NM, Valadares N, Galler R. Generation and Characterization of Murine Monoclonal Antibodies anti-PBP2a of Methicillin-resistantStaphylococcus aureus. Monoclon Antib Immunodiagn Immunother 2015; 34:257-62. [DOI: 10.1089/mab.2015.0013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- José Procópio M. Senna
- Instituto de Tecnologia em Imunobiológicos – BioManguinhos – Fiocruz, Rio de Janeiro, Brazil
| | | | - Marta de A. Santiago
- Instituto de Tecnologia em Imunobiológicos – BioManguinhos – Fiocruz, Rio de Janeiro, Brazil
| | - Nádia M. Batoréu
- Instituto de Tecnologia em Imunobiológicos – BioManguinhos – Fiocruz, Rio de Janeiro, Brazil
| | - Napoleão Valadares
- Laboratório de Biofísica Molecular, Departamento de Biologia Celular, Universidade de Brasília, Brasília, Brazil
- Center for Structural Molecular Biotechnology, Physics Institute, Universidade Federal de São Carlos, São Carlos, Brazil
| | - Ricardo Galler
- Instituto de Tecnologia em Imunobiológicos – BioManguinhos – Fiocruz, Rio de Janeiro, Brazil
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317
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Wong FC, Tan ST, Chai TT. Phytochemical-mediated Protein Expression Profiling and the Potential Applications in Therapeutic Drug Target Identifications. Crit Rev Food Sci Nutr 2015; 56 Suppl 1:S162-70. [DOI: 10.1080/10408398.2015.1045967] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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318
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Intravenous Antibiotics Used in the Treatment of Methicillin-Resistant Staphylococcus Aureus. AACN Adv Crit Care 2015. [PMID: 26200732 DOI: 10.1097/nci.0000000000000095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) continues to cause significant morbidity and mortality. Despite advances in medical care, the prevalence of both community-acquired and hospital-acquired MRSA has progressively increased. Community-acquired MRSA typically occurs in patients without recent illness or hospitalization, presents as acute skin and soft tissue infections, and is usually not multidrug resistant. Hospital-acquired MRSA, however, presents in patients recently hospitalized or treated in long-term care settings and in those who have had medical procedures and is usually associated with multidrug-resistant strains. Both types of infections, if not properly treated, have the potential to become invasive. This article discusses current intravenous antibiotics that are available for the empiric treatment of MRSA infections along with a newer phenomenon known as the "seesaw effect."
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319
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Scordo KA. Intravenous Antibiotics Used in the Treatment of Methicillin-Resistant Staphylococcus Aureus. AACN Adv Crit Care 2015. [DOI: 10.4037/nci.0000000000000095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) continues to cause significant morbidity and mortality. Despite advances in medical care, the prevalence of both community-acquired and hospital-acquired MRSA has progressively increased. Community-acquired MRSA typically occurs in patients without recent illness or hospitalization, presents as acute skin and soft tissue infections, and is usually not multidrug resistant. Hospital-acquired MRSA, however, presents in patients recently hospitalized or treated in long-term care settings and in those who have had medical procedures and is usually associated with multidrug-resistant strains. Both types of infections, if not properly treated, have the potential to become invasive. This article discusses current intravenous antibiotics that are available for the empiric treatment of MRSA infections along with a newer phenomenon known as the “seesaw effect.”
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Affiliation(s)
- Kristine Anne Scordo
- Kristine Anne Scordo is Professor and Director, Adult-Gerontology Acute Care Nurse Practitioner Program, College of Nursing, Wright State University, Dayton, OH 45435
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320
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Mueller K, McCammon C, Skrupky L, Fuller BM. Vancomycin Use in Patients Discharged From the Emergency Department: A Retrospective Observational Cohort Study. J Emerg Med 2015; 49:50-7. [PMID: 25802166 DOI: 10.1016/j.jemermed.2015.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 12/23/2014] [Accepted: 01/05/2015] [Indexed: 12/01/2022]
Abstract
BACKGROUND Infections due to methicillin-resistant Staphylococcus aureus (MRSA) are associated with significant morbidity and mortality and are typically treated with intravenous vancomycin. Given vancomycin's time-dependent mechanism of action, it is unlikely that vancomycin administration in the emergency department (ED) prior to disposition home could be beneficial. STUDY OBJECTIVES To characterize the indications, dosing, and appropriateness of vancomycin use in patients discharged from the ED. METHODS This is a single-center retrospective observational cohort study of patients who received vancomycin in an urban, academic, tertiary care ED. The subjects were consecutive adult patients administered intravenous vancomycin in the ED and then discharged home over an 18-month period. Outcomes were measured 1) to characterize patients receiving vancomycin prior to discharge home from the ED; and 2) to identify patients that did not meet indications for appropriate use based on the 2011 Infectious Diseases Society of America guidelines for treating MRSA infections. RESULTS There were 526 patients that received vancomycin in the ED prior to discharge during the study period. In this cohort, 368 (70%) patients were diagnosed with skin and soft tissue infections. A MRSA risk factor was present in 396 (75%) patients. Prior to discharge, one dose of vancomycin was administered to 357 (68%) patients. Underdosing of vancomycin occurred in 239 (73%) patients. CONCLUSIONS Vancomycin was given frequently to patients discharged home from the ED, most commonly for conditions where vancomycin was not indicated, such as skin and soft tissue infections. The majority of these patients received a vancomycin dosing strategy that is not only unlikely to lead to clinical improvement, but also has the potential to contribute adversely to the development of antibiotic resistance. Further investigation is needed into the impact of vancomycin use, the emergence of vancomycin resistance, and the role of ED-based antibiotic stewardship.
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Affiliation(s)
- Kristen Mueller
- Division of Emergency Medicine, Washington University School of Medicine and Barnes Jewish Hospital, Saint Louis, Missouri
| | - Craig McCammon
- Department of Pharmacy, Barnes Jewish Hospital, Saint Louis, Missouri
| | - Lee Skrupky
- Department of Pharmacy, Barnes Jewish Hospital, Saint Louis, Missouri
| | - Brian M Fuller
- Division of Emergency Medicine, Department of Anesthesiology, Division of Critical Care, Washington University School of Medicine, Saint Louis, Missouri
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321
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Evolution and single-nucleotide polymorphisms in methicillin-resistant Staphylococcus aureus strains with reduced susceptibility to vancomycin and daptomycin, based on determination of the complete genome. Antimicrob Agents Chemother 2015; 59:3585-7. [PMID: 25779584 DOI: 10.1128/aac.05159-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Accepted: 03/11/2015] [Indexed: 11/20/2022] Open
Abstract
We obtained a series of methicillin-resistant Staphylococcus aureus isolates, including both daptomycin-susceptible strain TD1 and daptomycin-resistant strain TD4, from a patient. We determined the complete genome sequences of TD1 and TD4 using next-generation sequencing, and only four single-nucleotide polymorphisms (SNPs) were identified, one each in capB (E58K), rpoB (H481Y), lytN (I16V), and mprF (V351E). We determined that these four SNPs were sufficient to cause the strains to develop daptomycin, vancomycin, and rifampin resistance.
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322
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Cuny C, Layer F, Werner G, Harmsen D, Daniels-Haardt I, Jurke A, Mellmann A, Witte W, Köck R. State-wide surveillance of antibiotic resistance patterns and spa types of methicillin-resistant Staphylococcus aureus from blood cultures in North Rhine-Westphalia, 2011-2013. Clin Microbiol Infect 2015; 21:750-7. [PMID: 25704447 DOI: 10.1016/j.cmi.2015.02.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 01/09/2015] [Accepted: 02/12/2015] [Indexed: 11/25/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of bacteraemia. We aimed to obtain a complete picture of severe MRSA infections by characterizing all MRSA isolates from bloodstream infections in the largest German federal state (North Rhine-Westphalia, 18 million inhabitants) using S. aureus protein A (spa) sequence-typing and antimicrobial susceptibility testing. MRSA isolates (n = 1952) were collected prospectively (2011-2013) and spa-typed. Among 181 different spa types, t003 (n = 746 isolates; 38.2%) and t032 (n = 594; 30.4%) were predominant. Analysis of the geographical occurrence of spa clonal complexes (spa-CCs) and spa types revealed divergent distribution between federal state districts for spa-CCs 003 (p < 0.001; including t003, p < 0.001 and t264, p < 0.001), 008 (p 0.021), 011 (p 0.002), 032 (p < 0.001; including t022, p 0.014 and t032, p < 0.001) and spa type t2807 (p < 0.001). MICs of antimicrobial substances were tested using broth microdilution. Of all isolates, 96% were resistant to fluoroquinolones, 78% to erythromycin, 70% to clindamycin, 4% to gentamicin, 2% to rifampicin, 0.4% to daptomycin, 0.1% to linezolid and 0% to vancomycin, respectively. Vancomycin MICs of 2 mg/L involved 0.5% of the isolates. In conclusion, the detection of regional molecular clusters added valuable information for epidemiological case tracing and allowed conclusions to be reached on the importance of newly emerging MRSA reservoirs, such as livestock (spa-CC011), for MRSA bacteraemia in some parts of the federal state. Susceptibility testing revealed broad resistance to substances used for oral treatment, but demonstrated that those antibiotics that are mostly applied for treatment of MRSA bacteraemia and important combination partners were highly susceptible.
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Affiliation(s)
- C Cuny
- Robert Koch-Institute, National Reference Laboratory for Staphylococci and Enterococci, Wernigerode, Germany
| | - F Layer
- Robert Koch-Institute, National Reference Laboratory for Staphylococci and Enterococci, Wernigerode, Germany
| | - G Werner
- Robert Koch-Institute, National Reference Laboratory for Staphylococci and Enterococci, Wernigerode, Germany
| | - D Harmsen
- Department of Periodontology, University Hospital Münster, Münster, Germany
| | | | - A Jurke
- Centre for Health North Rhine-Westphalia, Münster, Germany
| | - A Mellmann
- Institute of Hygiene, University Hospital Münster, Münster, Germany
| | - W Witte
- Robert Koch-Institute, National Reference Laboratory for Staphylococci and Enterococci, Wernigerode, Germany
| | - R Köck
- Institute of Hygiene, University Hospital Münster, Münster, Germany; Institute of Medical Microbiology, University Hospital Münster, Münster, Germany.
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323
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Abstract
Gram-positive organisms, including the pathogens Staphylococcus aureus, Streptococcus pneumoniae, and Enterococcus faecalis, have dynamic cell envelopes that mediate interactions with the environment and serve as the first line of defense against toxic molecules. Major components of the cell envelope include peptidoglycan (PG), which is a well-established target for antibiotics, teichoic acids (TAs), capsular polysaccharides (CPS), surface proteins, and phospholipids. These components can undergo modification to promote pathogenesis, decrease susceptibility to antibiotics and host immune defenses, and enhance survival in hostile environments. This chapter will cover the structure, biosynthesis, and important functions of major cell envelope components in gram-positive bacteria. Possible targets for new antimicrobials will be noted.
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324
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Boukouvalas J, Thibault C. Step-Economical Synthesis of the Marine Ascidian Antibiotics Cadiolide A, B, and D. J Org Chem 2014; 80:681-4. [DOI: 10.1021/jo502503w] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- John Boukouvalas
- Département de Chimie, Université Laval, Pavillon Alexandre-Vachon, 1045 Avenue de la Médecine, Quebec City, Quebec G1V 0A6, Canada
| | - Charles Thibault
- Département de Chimie, Université Laval, Pavillon Alexandre-Vachon, 1045 Avenue de la Médecine, Quebec City, Quebec G1V 0A6, Canada
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