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Wang J, Zhou X, Li W, Deng X, Deng Y, Niu X. Curcumin protects mice from Staphylococcus aureus pneumonia by interfering with the self-assembly process of α-hemolysin. Sci Rep 2016; 6:28254. [PMID: 27345357 PMCID: PMC4921848 DOI: 10.1038/srep28254] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 06/01/2016] [Indexed: 02/07/2023] Open
Abstract
α-hemolysin (Hla) is a self-assembling extracellular protein secreted as a soluble monomer by most Staphylococcus aureus strains and is an essential virulence factor for the pathogenesis of various S. aureus infections. Here, we show that curcumin (CUR), a natural compound with weak anti-S. aureus activity, can inhibit the hemolysis induced by Hla. Molecular dynamics simulations, free energy calculations, and mutagenesis assays were further employed for the Hla-CUR complex to determine the mechanism of such inhibition. The analysis of this combined approach indicated that the direct binding CUR to Hla blocks the conformational transition of Hla from the monomer to the oligomer, leading to an inhibition of Hla hemolytic activity. We also found that the addition of CUR significantly attenuated Hla-mediated injury of human alveolar cell (A549) co-cultured with S. aureus. The in vivo data further demonstrated that treatment with CUR protects mice from pneumonia caused by S. aureus, including methicillin-resistant strains (MRSA). These findings suggest that CUR inhibits the pore-forming activity of Hla through a novel mechanism, which would pave the way for the development of new and more effective antibacterial agents to combat S. aureus pneumonia.
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Affiliation(s)
- Jianfeng Wang
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, and Department of Food Quality and Safety, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xuan Zhou
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, and Department of Food Quality and Safety, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Wenhua Li
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, and Department of Food Quality and Safety, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xuming Deng
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, and Department of Food Quality and Safety, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Yanhong Deng
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, and Department of Food Quality and Safety, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xiaodi Niu
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, and Department of Food Quality and Safety, College of Veterinary Medicine, Jilin University, Changchun, China
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Tong SYC, Nelson J, Paterson DL, Fowler VG, Howden BP, Cheng AC, Chatfield M, Lipman J, Van Hal S, O’Sullivan M, Robinson JO, Yahav D, Lye D, Davis JS. CAMERA2 - combination antibiotic therapy for methicillin-resistant Staphylococcus aureus infection: study protocol for a randomised controlled trial. Trials 2016; 17:170. [PMID: 27029920 PMCID: PMC4815121 DOI: 10.1186/s13063-016-1295-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 03/17/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia is a serious infection resulting in 20-50 % 90-day mortality. The limitations of vancomycin, the current standard therapy for MRSA, make treatment difficult. The only other approved drug for treatment of MRSA bacteraemia, daptomycin, has not been shown to be superior to vancomycin. Surprisingly, there has been consistent in-vitro and in-vivo laboratory data demonstrating synergy between vancomycin or daptomycin and an anti-staphylococcal β-lactam antibiotic. There is also growing clinical data to support such combinations, including a recent pilot randomised controlled trial (RCT) that demonstrated a trend towards a reduction in the duration of bacteraemia in patients treated with vancomycin plus flucloxacillin compared to vancomycin alone. Our aim is to determine whether the addition of an anti-staphylococcal penicillin to standard therapy results in improved clinical outcomes in MRSA bacteraemia. METHODS/DESIGN We will perform an open-label, parallel-group, randomised (1:1) controlled trial at 29 sites in Australia, New Zealand, Singapore, and Israel. Adults (aged 18 years or older) with MRSA grown from at least one blood culture and able to be randomised within 72 hours of the index blood culture collection will be eligible for inclusion. Participants will be randomised to vancomycin or daptomycin (standard therapy) given intravenously or to standard therapy plus 7 days of an anti-staphylococcal β-lactam (flucloxacillin, cloxacillin, or cefazolin). The primary endpoint will be a composite outcome at 90 days of (1) all-cause mortality, (2) persistent bacteraemia at day 5 or beyond, (3) microbiological relapse, or (4) microbiological treatment failure. The recruitment target of 440 patients is based on an expected failure rate for the primary outcome of 30 % in the control arm and the ability to detect a clinically meaningful absolute decrease of 12.5 %, with a two-sided alpha of 0.05, a power of 80 %, and assuming 10 % of patients will not be evaluable for the primary endpoint. DISCUSSION Key potential advantages of adding anti-staphylococcal β-lactams to standard therapy for MRSA bacteraemia include their safety profile, low cost, and wide availability. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02365493 . Registered 24 February 2015.
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Affiliation(s)
- Steven Y. C. Tong
- />Menzies School of Health Research, Charles Darwin University, Darwin, NT Australia
- />Royal Darwin Hospital, Darwin, NT Australia
| | - Jane Nelson
- />Menzies School of Health Research, Charles Darwin University, Darwin, NT Australia
| | - David L. Paterson
- />University of Queensland, Centre for Clinical Research, Herston, QLD Australia
| | - Vance G. Fowler
- />Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, NC USA
- />Duke Clinical Research Institute, Duke University Medical Center, Durham, NC USA
| | - Benjamin P. Howden
- />Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne, at The Doherty Institute, Melbourne, VIC Australia
| | - Allen C. Cheng
- />Infection Prevention and Healthcare Epidemiology Unit, Alfred Health, Melbourne, VIC Australia
- />Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC Australia
| | - Mark Chatfield
- />Menzies School of Health Research, Charles Darwin University, Darwin, NT Australia
| | - Jeffrey Lipman
- />Burns, Trauma Critical Care Research Centre, The University of Queensland, Brisbane, QLD Australia
- />Faculty of Health, Queensland University of Technology, Brisbane, QLD Australia
| | - Sebastian Van Hal
- />Department of Microbiology and Infectious Disease Royal Prince Alfred Hospital, Sydney, NSW Australia
| | - Matthew O’Sullivan
- />Centre for Infectious Diseases and Microbiology, Westmead Hospital, Sydney, NSW Australia
- />Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW Australia
| | - James O. Robinson
- />Department of Microbiology and Infectious Diseases, Pathwest Laboratory Medicine WA, Royal Perth Hospital and Fiona Stanley Hospital, Perth, WA Australia
- />Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, School of Veterinary and Life Sciences, Murdoch University, Perth, WA Australia
| | - Dafna Yahav
- />Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
- />Rabin Medical Center, Petah Tikvah, Israel
| | - David Lye
- />Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, Singapore, Singapore
- />Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Joshua S. Davis
- />Menzies School of Health Research, Charles Darwin University, Darwin, NT Australia
- />John Hunter Hospital, Newcastle, NSW Australia
| | - for the CAMERA2 study group and the Australasian Society for Infectious Diseases Clinical Research Network
- />Menzies School of Health Research, Charles Darwin University, Darwin, NT Australia
- />Royal Darwin Hospital, Darwin, NT Australia
- />University of Queensland, Centre for Clinical Research, Herston, QLD Australia
- />Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, NC USA
- />Duke Clinical Research Institute, Duke University Medical Center, Durham, NC USA
- />Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne, at The Doherty Institute, Melbourne, VIC Australia
- />Infection Prevention and Healthcare Epidemiology Unit, Alfred Health, Melbourne, VIC Australia
- />Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC Australia
- />Burns, Trauma Critical Care Research Centre, The University of Queensland, Brisbane, QLD Australia
- />Faculty of Health, Queensland University of Technology, Brisbane, QLD Australia
- />Department of Microbiology and Infectious Disease Royal Prince Alfred Hospital, Sydney, NSW Australia
- />Centre for Infectious Diseases and Microbiology, Westmead Hospital, Sydney, NSW Australia
- />Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW Australia
- />Department of Microbiology and Infectious Diseases, Pathwest Laboratory Medicine WA, Royal Perth Hospital and Fiona Stanley Hospital, Perth, WA Australia
- />Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, School of Veterinary and Life Sciences, Murdoch University, Perth, WA Australia
- />Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
- />Rabin Medical Center, Petah Tikvah, Israel
- />Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, Singapore, Singapore
- />Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- />John Hunter Hospital, Newcastle, NSW Australia
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Jang S. Multidrug efflux pumps in Staphylococcus aureus and their clinical implications. J Microbiol 2016; 54:1-8. [DOI: 10.1007/s12275-016-5159-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 10/29/2015] [Accepted: 10/30/2015] [Indexed: 12/13/2022]
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Fosfomycin plus β-Lactams as Synergistic Bactericidal Combinations for Experimental Endocarditis Due to Methicillin-Resistant and Glycopeptide-Intermediate Staphylococcus aureus. Antimicrob Agents Chemother 2015; 60:478-86. [PMID: 26525803 DOI: 10.1128/aac.02139-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 10/28/2015] [Indexed: 02/01/2023] Open
Abstract
The urgent need of effective therapies for methicillin-resistant Staphylococcus aureus (MRSA) infective endocarditis (IE) is a cause of concern. We aimed to ascertain the in vitro and in vivo activity of the older antibiotic fosfomycin combined with different beta-lactams against MRSA and glycopeptide-intermediate-resistant S. aureus (GISA) strains. Time-kill tests with 10 isolates showed that fosfomycin plus imipenem (FOF+IPM) was the most active evaluated combination. In an aortic valve IE model with two strains (MRSA-277H and GISA-ATCC 700788), the following intravenous regimens were compared: fosfomycin (2 g every 8 h [q8h]) plus imipenem (1 g q6h) or ceftriaxone (2 g q12h) (FOF+CRO) and vancomycin at a standard dose (VAN-SD) (1 g q12h) and a high dose (VAN-HD) (1 g q6h). Whereas a significant reduction of MRSA-227H load in the vegetations (veg) was observed with FOF+IPM compared with VAN-SD (0 [interquartile range [IQR], 0 to 1] versus 2 [IQR, 0 to 5.1] log CFU/g veg; P = 0.01), no statistical differences were found with VAN-HD. In addition, FOF+IPM sterilized more vegetations than VAN-SD (11/15 [73%] versus 5/16 [31%]; P = 0.02). The GISA-ATCC 700788 load in the vegetations was significantly lower after FOF+IPM or FOF+CRO treatment than with VAN-SD (2 [IQR, 0 to 2] and 0 [IQR, 0 to 2] versus 6.5 [IQR, 2 to 6.9] log CFU/g veg; P < 0.01). The number of sterilized vegetations after treatment with FOF+CRO was higher than after treatment with VAN-SD or VAN-HD (8/15 [53%] versus 4/20 [20%] or 4/20 [20%]; P = 0.03). To assess the effect of FOF+IPM on penicillin binding protein (PBP) synthesis, molecular studies were performed, with results showing that FOF+IPM treatment significantly decreased PBP1, PBP2 (but not PBP2a), and PBP3 synthesis. These results allow clinicians to consider the use of FOF+IPM or FOF+CRO to treat MRSA or GISA IE.
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Combination Therapy of LysGH15 and Apigenin as a New Strategy for Treating Pneumonia Caused by Staphylococcus aureus. Appl Environ Microbiol 2015; 82:87-94. [PMID: 26475103 DOI: 10.1128/aem.02581-15] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 10/10/2015] [Indexed: 01/11/2023] Open
Abstract
Pneumonia is one of the most prevalent Staphylococcus aureus-mediated diseases, and the treatment of this infection is becoming challenging due to the emergence of multidrug-resistant S. aureus, especially methicillin-resistant S. aureus (MRSA) strains. It has been reported that LysGH15, the lysin derived from phage GH15, displays high efficiency and a broad lytic spectrum against MRSA and that apigenin can markedly diminish the alpha-hemolysin of S. aureus. In this study, the combination therapy of LysGH15 and apigenin was evaluated in vitro and in a mouse S. aureus pneumonia model. No mutual adverse influence was detected between LysGH15 and apigenin in vitro. In animal experiments, the combination therapy showed a more effective treatment effect than LysGH15 or apigenin monotherapy (P < 0.05). The bacterial load in the lungs of mice administered the combination therapy was 1.5 log units within 24 h after challenge, whereas the loads in unprotected mice or mice treated with apigenin or LysGH15 alone were 10.2, 4.7, and 2.6 log units, respectively. The combination therapy group showed the best health status, the lowest ratio of wet tissue to dry tissue of the lungs, the smallest amount of total protein and cells in the lung, the fewest pathological manifestations, and the lowest cytokine level compared with the other groups (P < 0.05). With regard to its better protective efficacy, the combination therapy of LysGH15 and apigenin exhibits therapeutic potential for treating pneumonia caused by MRSA. This paper reports the combination therapy of lysin and natural products derived from traditional Chinese medicine.
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Guo N, Zhao X, Li W, Shi C, Meng R, Liu Z, Yu L. The synergy of berberine chloride and totarol against Staphylococcus aureus grown in planktonic and biofilm cultures. J Med Microbiol 2015; 64:891-900. [DOI: 10.1099/jmm.0.000106] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Na Guo
- Department of Food Quality and Safety, College of Quartermaster Technology, Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, 130062 Changchun, PR China
| | - Xingchen Zhao
- Department of Food Quality and Safety, College of Quartermaster Technology, Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, 130062 Changchun, PR China
| | - Wenli Li
- Department of Food Quality and Safety, College of Quartermaster Technology, Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, 130062 Changchun, PR China
| | - Ce Shi
- Department of Food Quality and Safety, College of Quartermaster Technology, Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, 130062 Changchun, PR China
| | - Rizeng Meng
- Jilin Entry-Exit Inspection and Quarantine Bureau, 130062 Changchun, PR China
| | - Zonghui Liu
- Department of Food Quality and Safety, College of Quartermaster Technology, Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, 130062 Changchun, PR China
| | - Lu Yu
- Department of Food Quality and Safety, College of Quartermaster Technology, Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, 130062 Changchun, PR China
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Subramenium GA, Vijayakumar K, Pandian SK. Limonene inhibits streptococcal biofilm formation by targeting surface-associated virulence factors. J Med Microbiol 2015; 64:879-890. [DOI: 10.1099/jmm.0.000105] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
| | - Karuppiah Vijayakumar
- Department of Biotechnology, Alagappa University, Science Campus, Karaikudi 630 004, Tamil Nadu, India
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Scott LJ, Frampton JE. Ceftaroline fosamil: a guide to its use in complicated skin and soft tissue infections and community-acquired pneumonia in the EU. DRUGS & THERAPY PERSPECTIVES 2015. [DOI: 10.1007/s40267-014-0174-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Mohammad H, Mayhoub AS, Cushman M, Seleem MN. Anti-biofilm activity and synergism of novel thiazole compounds with glycopeptide antibiotics against multidrug-resistant staphylococci. J Antibiot (Tokyo) 2014; 68:259-66. [PMID: 25315757 DOI: 10.1038/ja.2014.142] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 09/03/2014] [Accepted: 09/08/2014] [Indexed: 11/09/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections are a leading cause of death among all fatalities caused by antibiotic-resistant bacteria. With the rise of increasing resistance to current antibiotics, new antimicrobials and treatment strategies are urgently needed. Thiazole compounds have been shown to possess potent antimicrobial activity. A lead thiazole 1 and a potent derivative 2 were synthesized and their activity in combination with glycopeptide antibiotics was determined against an array of MRSA and vancomycin-resistant S. aureus (VRSA) clinical isolates. In addition, the anti-biofilm activity of the novel thiazoles was investigated against S. epidermidis. Compound 2 behaved synergistically with vancomycin against MRSA and was able to resensitize VRSA to vancomycin, reducing its MIC by 512-fold in two strains. In addition, both thiazole compounds were superior to vancomycin in significantly reducing S. epidermidis biofilm mass. Collectively, the results obtained demonstrate that compounds 1 and 2 possess potent antimicrobial activity alone or in combination with vancomycin against multidrug-resistant staphylococci and show potential for use in disrupting staphylococcal biofilm.
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Affiliation(s)
- Haroon Mohammad
- Department of Comparative Pathobiology, Purdue University College of Veterinary Medicine, West Lafayette, IN, USA
| | | | - Mark Cushman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University College of Pharmacy and the Purdue Center for Cancer Research, West Lafayette, IN, USA
| | - Mohamed N Seleem
- Department of Comparative Pathobiology, Purdue University College of Veterinary Medicine, West Lafayette, IN, USA
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Rodvold KA, McConeghy KW. Methicillin-Resistant Staphylococcus aureus Therapy: Past, Present, and Future. Clin Infect Dis 2013; 58 Suppl 1:S20-7. [DOI: 10.1093/cid/cit614] [Citation(s) in RCA: 233] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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Antiadherent and antibiofilm activity of Humulus lupulus L. derived products: new pharmacological properties. BIOMED RESEARCH INTERNATIONAL 2013; 2013:101089. [PMID: 24175280 PMCID: PMC3794639 DOI: 10.1155/2013/101089] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 08/16/2013] [Accepted: 08/20/2013] [Indexed: 12/11/2022]
Abstract
New antimicrobial properties of products derived from Humulus lupulus L. such as antiadherent and antibiofilm activities were evaluated. The growth of gram-positive but not gram-negative bacteria was inhibited to different extents by these compounds. An extract of hop cones containing 51% xanthohumol was slightly less active against S. aureus strains (MIC range 31.2-125.0 μg/mL) than pure xanthohumol (MIC range 15.6-62.5 μg/mL). The spent hop extract, free of xanthohumol, exhibited lower but still relevant activity (MIC range 1-2 mg/mL). There were positive coactions of hop cone, spent hop extracts, and xanthohumol with oxacillin against MSSA and with linezolid against MSSA and MRSA. Plant compounds in the culture medium at sub-MIC concentrations decreased the adhesion of Staphylococci to abiotic surfaces, which in turn caused inhibition of biofilm formation. The rate of mature biofilm eradication by these products was significant. The spent hop extract at MIC reduced biofilm viability by 42.8%, the hop cone extract by 74.8%, and pure xanthohumol by 86.5%. When the hop cone extract or xanthohumol concentration was increased, almost complete biofilm eradication was achieved (97-99%). This study reveals the potent antibiofilm activity of hop-derived compounds for the first time.
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Flanagan SD, Bien PA, Muñoz KA, Minassian SL, Prokocimer PG. Pharmacokinetics of tedizolid following oral administration: single and multiple dose, effect of food, and comparison of two solid forms of the prodrug. Pharmacotherapy 2013; 34:240-50. [PMID: 23926058 PMCID: PMC4238735 DOI: 10.1002/phar.1337] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Objectives The single- and multiple-dose pharmacokinetics (PK) of tedizolid were examined after oral administration of tedizolid phosphate disodium (TPD), including the effect of food on PK. The relative bioavailability of TPD to the free acid tedizolid phosphate was determined to bridge the results of these and other studies to the solid form of the prodrug selected for further development. Design Randomized placebo-controlled, double-blind single- and multiple-ascending dose studies and randomized open-label, crossover food effect and relative bioavailability studies. Setting Clinical Research Units. Participants Healthy subjects. Intervention Study TR701-101 enrolled 40 subjects in single-ascending dose (200–1200 mg TPD or placebo) and 40 subjects in 21-day multiple-ascending dose (200, 300, or 400 mg TPD once/day; 600 mg linezolid twice/day; or placebo) arms. Study TR701-103 was a food-effect study in 12 subjects administered 600 mg TPD. Study TR701-108 was a relative bioavailability study in 12 subjects administered 150-mg tedizolid equivalents as TPD or tedizolid phosphate. Measurements and Main Results Plasma concentrations of the prodrug tedizolid phosphate, its active moiety tedizolid, and/or linezolid were collected. After administration of 200 to 600 mg TPD, tedizolid values increased approximately dose proportionally in area under the concentration-time curve (AUC) and maximum plasma concentration (Cmax). Tedizolid half-life values were approximately 2-fold greater compared with linezolid. TPD administration with food delayed tedizolid absorption and reduced Cmax relative to the fasted state but did not alter AUC. Minimal accumulation was predicted and observed for tedizolid, whereas observed accumulation of linezolid exceeded predictions based on single-dose PK. Comparable PK of tedizolid was observed following oral administration of either TPD or tedizolid phosphate. In the multiple-ascending dose study, 3 of 24 tedizolid subjects were withdrawn under prespecified stopping rules (one each of elevated alanine aminotransferase, low reticulocyte count, or low white blood cell count), as was 1 of 8 linezolid subjects (low reticulocyte count). Conclusions Overall, tedizolid has a favorable PK profile, a half-life that supports once daily administration, and no nonlinearities at steady state. Tedizolid phosphate can be administered without regard to food.
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Frampton JE. Ceftaroline fosamil: a review of its use in the treatment of complicated skin and soft tissue infections and community-acquired pneumonia. Drugs 2013; 73:1067-94. [PMID: 23801418 DOI: 10.1007/s40265-013-0075-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Ceftaroline, the active metabolite of the prodrug ceftaroline fosamil (Zinforo, Teflaro), is an advanced-generation, parenteral cephalosporin with broad-spectrum antibacterial activity in vitro against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and multidrug resistant Streptococcus pneumoniae and Gram-negative bacteria, including Haemophilus influenzae and Moraxella catarrhalis, but not Pseudomonas aeruginosa. Ceftaroline has demonstrated a low potential for the selection of resistance in vitro for drug-resistant Gram-positive organisms, including MRSA, as well as for Gram-negative respiratory pathogens. In pivotal phase III studies, intravenous ceftaroline fosamil demonstrated noninferiority to intravenous vancomycin plus aztreonam in patients hospitalized with complicated skin and soft tissue infections (cSSTIs) and intravenous ceftriaxone in patients hospitalized with community-acquired pneumonia (CAP) [Pneumonia Outcomes Research Team (PORT) risk class III or IV]; however, patients with CAP admitted to the intensive care unit were not evaluated. Ceftaroline fosamil was generally well tolerated in these trials, with an adverse event profile similar to that of other cephalosporins. Diarrhoea was the most commonly reported adverse event; however, the risk of Clostridium difficile-associated diarrhoea with ceftaroline fosamil appeared to be low. Potential limitations of the drug include the lack of an oral formulation and the requirement for twice-daily administration. Nonetheless, ceftaroline fosamil represents an attractive option (either alone or in combination with other agents) for the initial empirical treatment of patients hospitalized with cSSTIs (including those with suspected MRSA infection) or CAP (PORT risk class III or IV) who require intravenous antimicrobial therapy. As with all antibacterial agents, ceftaroline fosamil should be used in accordance with good antimicrobial stewardship.
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Affiliation(s)
- James E Frampton
- Adis, 41 Centorian Drive, Private Bag 65901, Mairangi Bay, North Shore, 0754 Auckland, New Zealand.
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Zhang Y, Teng D, Mao R, Wang X, Xi D, Hu X, Wang J. High expression of a plectasin-derived peptide NZ2114 in Pichia pastoris and its pharmacodynamics, postantibiotic and synergy against Staphylococcus aureus. Appl Microbiol Biotechnol 2013; 98:681-94. [PMID: 23624708 DOI: 10.1007/s00253-013-4881-2] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 03/04/2013] [Accepted: 03/24/2013] [Indexed: 01/12/2023]
Abstract
NZ2114, a new variant of plectasin, was overexpressed in Pichia pastoris X-33 via pPICZαA for the first time. The total secreted protein of fermentation supernatant reached 2,390 mg/l (29 °C) and 2,310 mg/l (25 °C), and the recombinant NZ2114 (rNZ2114) reached 860 mg/l (29 °C) and 1,309 mg/l (25 °C) at 96 h induction in a 5-l fermentor, respectively.The rNZ2114 was purified by cation exchange chromatography, and its yield was 583 mg/l with 94.8 % purity. The minimal inhibitory concentration (MIC) of rNZ2114 to four ATCC strains of Staphyloccocus aureus was evaluated from 0.028 to 0.90 μM. Meanwhile, it showed potent activity (0.11-0.90 μM) to 20 clinical isolates of MRSA. The rNZ2114 killed over 99.9 % of tested S. aureus (ATCC 25923 and ATCC 43300) in Mueller-Hinton medium within 6 h when treated with 4 × MIC. The postantibiotic effect of rNZ2114 to S. aureus ATCC 25923 and ATCC 43300 was 18.6-45.6 and 1.7-3.5 h under 1×, 2×, and 4× MIC, respectively. The fractional inhibitory concentration index (FICI) indicated a synergistic effect between rNZ2114 and kanamycin, streptomycin, and vancomycin against S. aureus ATCC 25923 (FICI = 0.125), and additivity between rNZ2114 and ampicillin, spectinomycin (FICI = 0.625), respectively. To S. aureus ATCC 43300 [methicillin-resistant S. aureus (MRSA)], rNZ2114 showed a synergistic effect (FICI = 0.125-0.3125) with kanamycin, ampicillin, streptomycin, and vancomycin, and antagonism with spectinomycin (FICI = 8.0625). The rNZ2114 caused only less than 0.1 % hemolytic activity in the concentration of 128 μg/ml, and showed a good thermostability from 20 to 80 °C. In addition, it exhibited the highest activity at pH 8.0. These results suggested that large-scale production of NZ2114 is feasible using the P. pastoris expression system, and it could be a new potential antimicrobial agent for the prevention and treatment of S. aureus especially for MRSA infections.
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Affiliation(s)
- Yong Zhang
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture, Beijing, 100081, China
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Farag N, Mahran L, Abou-Aisha K, El-Azizi M. Assessment of the efficacy of polyclonal intravenous immunoglobulin G (IVIG) against the infectivity of clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) in vitro and in vivo. Eur J Clin Microbiol Infect Dis 2013; 32:1149-60. [PMID: 23532569 DOI: 10.1007/s10096-013-1861-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 03/08/2013] [Indexed: 01/02/2023]
Abstract
The response to treatment of severe methicillin-resistant Staphylococcus aureus (MRSA) infections with the traditional antibiotics is sometimes unsatisfactory and multiple antibiotic resistance is common. Adjuvant therapy such as intravenous immunoglobulin G (IVIG) could possibly be helpful in the treatment of such infections. The effect of IVIG on the capacity of human neutrophils to phagocytose and kill MRSA was investigated in vitro using the MTT assay and measuring the production of reactive oxygen species (ROS) and nitric oxide (NO). The efficiency of IVIG in neutralizing α-hemolysin and coagulase of MRSA was also assessed. The capability of IVIG in the treatment and prevention of MRSA infections was also evaluated in a murine peritonitis model. IVIG significantly enhanced (p < 0.01) the killing of MRSA by neutrophils at all concentrations tested (0.1-5 mg/ml) by 30-80 % of control values. It significantly (p < 0.01) increased the level of NO production in a dose-dependent manner, giving up to 60 μM at 5 mg/ml. The ROS level significantly increased (p < 0.01) in the presence of IVIG. In addition, IVIG significantly reduced the hemolytic activity of MRSA 10-fold and its coagulation capabilities by 50 %. When tested in vivo, groups receiving IVIG via tail vein infusion showed no significant improvement in their survival. Only when delivered to the same site of infection did IVIG show an improvement in the survival of mice (n = 80). These results could pave the way for a better understanding of the mechanism of action of IVIG and suggest its clinical potential as an adjuvant preventive and therapeutic agent against life-threatening infections caused by MRSA and other bacteria.
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Affiliation(s)
- N Farag
- Faculty of Pharmacy and Biotechnology, German University in Cairo, Main Entrance Al Tagamoaa Al Khames, New Cairo City, Egypt
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66
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Choi KH, Lee HJ, Park BJ, Wang KK, Shin EP, Park JC, Kim YK, Oh MK, Kim YR. Photosensitizer and vancomycin-conjugated novel multifunctional magnetic particles as photoinactivation agents for selective killing of pathogenic bacteria. Chem Commun (Camb) 2012; 48:4591-3. [PMID: 22473513 DOI: 10.1039/c2cc17766h] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Novel multifunctional magnetic particles (MMPs) conjugated with photosensitizer and vancomycin were fabricated by surface modification of Fe(3)O(4) particles. The capacities to target, capture and inactivate pathogenic bacteria and good biocompatibility suggest that the MMPs have great potentials as photodynamic inactivation agents for serious bacterial contamination.
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Affiliation(s)
- Kyong-Hoon Choi
- Photon Applied Functional Molecule Research Laboratory, Department of Chemistry, Yonsei University, Seoul 120-749, Republic of Korea
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67
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van Hal SJ, Jensen SO, Vaska VL, Espedido BA, Paterson DL, Gosbell IB. Predictors of mortality in Staphylococcus aureus Bacteremia. Clin Microbiol Rev 2012; 25:362-86. [PMID: 22491776 PMCID: PMC3346297 DOI: 10.1128/cmr.05022-11] [Citation(s) in RCA: 639] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus bacteremia (SAB) is an important infection with an incidence rate ranging from 20 to 50 cases/100,000 population per year. Between 10% and 30% of these patients will die from SAB. Comparatively, this accounts for a greater number of deaths than for AIDS, tuberculosis, and viral hepatitis combined. Multiple factors influence outcomes for SAB patients. The most consistent predictor of mortality is age, with older patients being twice as likely to die. Except for the presence of comorbidities, the impacts of other host factors, including gender, ethnicity, socioeconomic status, and immune status, are unclear. Pathogen-host interactions, especially the presence of shock and the source of SAB, are strong predictors of outcomes. Although antibiotic resistance may be associated with increased mortality, questions remain as to whether this reflects pathogen-specific factors or poorer responses to antibiotic therapy, namely, vancomycin. Optimal management relies on starting appropriate antibiotics in a timely fashion, resulting in improved outcomes for certain patient subgroups. The roles of surgery and infectious disease consultations require further study. Although the rate of mortality from SAB is declining, it remains high. Future international collaborative studies are required to tease out the relative contributions of various factors to mortality, which would enable the optimization of SAB management and patient outcomes.
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Affiliation(s)
- Sebastian J van Hal
- Department of Microbiology and Infectious Diseases, Sydney South West Pathology Service—Liverpool, South Western Sydney Local Health Network, Sydney, New South Wales, Australia.
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Kwong JC, Chua K, Charles PGP. Managing Severe Community-Acquired Pneumonia Due to Community Methicillin-Resistant Staphylococcus aureus (MRSA). Curr Infect Dis Rep 2012; 14:330-8. [DOI: 10.1007/s11908-012-0254-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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69
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Capsaicin protects mice from community-associated methicillin-resistant Staphylococcus aureus pneumonia. PLoS One 2012; 7:e33032. [PMID: 22427935 PMCID: PMC3299732 DOI: 10.1371/journal.pone.0033032] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 02/08/2012] [Indexed: 11/20/2022] Open
Abstract
Background α-toxin is one of the major virulence factors secreted by most Staphylococcus aureus strains, which played a central role in the pathogenesis of S. aureus pneumonia. The aim of this study was to investigate the impact of capsaicin on the production of α-toxin by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strain USA 300 and to further assess its performance in the treatment of CA-MRSA pneumonia in a mouse model. Methodology/Principal Findings The in vitro effects of capsaicin on α-toxin production by S. aureus USA 300 were determined using hemolysis, western blot, and real-time RT-PCR assays. The influence of capsaicin on the α-toxin-mediated injury of human alveolar epithelial cells was determined using viability and cytotoxicity assays. Mice were infected intranasally with S. aureus USA300; the in vivo protective effects of capsaicin against S. aureus pneumonia were assessed by monitoring the mortality, histopathological changes and cytokine levels. Low concentrations of capsaicin substantially decreased the production of α-toxin by S. aureus USA 300 without affecting the bacterial viability. The addition of capsaicin prevented α-toxin-mediated human alveolar cell (A549) injury in co-culture with S. aureus. Furthermore, the in vivo experiments indicated that capsaicin protected mice from CA-MRSA pneumonia caused by strain USA 300. Conclusions/Significance Capsaicin inhibits the production of α-toxin by CA-MRSA strain USA 300 in vitro and protects mice from CA-MRSA pneumonia in vivo. However, the results need further confirmation with other CA-MRSA lineages. This study supports the views of anti-virulence as a new antibacterial approach for chemotherapy.
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70
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A new pharmacological agent (AKB-4924) stabilizes hypoxia inducible factor-1 (HIF-1) and increases skin innate defenses against bacterial infection. J Mol Med (Berl) 2012; 90:1079-89. [PMID: 22371073 DOI: 10.1007/s00109-012-0882-3] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 02/01/2012] [Accepted: 02/09/2012] [Indexed: 12/26/2022]
Abstract
Hypoxia inducible factor-1 (HIF-1) is a transcription factor that is a major regulator of energy homeostasis and cellular adaptation to low oxygen stress. HIF-1 is also activated in response to bacterial pathogens and supports the innate immune response of both phagocytes and keratinocytes. In this work, we show that a new pharmacological compound AKB-4924 increases HIF-1 levels and enhances the antibacterial activity of phagocytes and keratinocytes against both methicillin-sensitive and methicillin-resistant strains of Staphylococcus aureus in vitro. AKB-4924 is also effective in stimulating the killing capacity of keratinocytes against the important opportunistic skin pathogens Pseudomonas aeruginosa and Acinetobacter baumanii. The effect of AKB-4924 is mediated through the activity of host cells, as the compound exerts no direct antimicrobial activity. Administered locally as a single agent, AKB-4924 limits S. aureus proliferation and lesion formation in a mouse skin abscess model. This approach to pharmacologically boost the innate immune response via HIF-1 stabilization may serve as a useful adjunctive treatment for antibiotic-resistant bacterial infections.
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Abstract
Diseases such as tuberculosis, hepatitis, and HIV/AIDS are caused by intracellular pathogens and are a major burden to the global medical community. Conventional treatments for these diseases typically consist of long-term therapy with a combination of drugs, which may lead to side effects and contribute to low patient compliance. The pathogens reside within intracellular compartments of the cell, which provide additional barriers to effective treatment. Therefore, there is a need for improved and more effective therapies for such intracellular diseases. This review will summarize, for the first time, the intracellular compartments in which pathogens can reside and discuss how nanomedicine has the potential to improve intracellular disease therapy by offering properties such as targeting, sustained drug release, and drug delivery to the pathogen’s intracellular location. The characteristics of nanomedicine may prove advantageous in developing improved or alternative therapies for intracellular diseases.
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Affiliation(s)
- Andrea L Armstead
- Biomaterials, Bioengineering and Nanotechnology Laboratory, Department of Orthopedics, School of Medicine, West Virginia University, Morgantown, WV 26506-9196, USA
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72
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Abstract
There is a choice of anti-MRSA antibiotic available with proven efficacy in the treatment of complicated skin and skin structure infection (cSSSI). Additional anti-MRSA antibiotics are in development, which have the potential to influence how such infections are managed. The emergence of resistance to current anti-MRSA agents, toxicity, and general lack of oral agents with proven efficacy for deep seated infection justify the development of new agents. However, there is a relative dearth of information specific to patients with orthopaedic-related infection. Combination therapy is often used in these patients, although there is a paucity of controlled trial data to support particular antibiotic combinations. As the choice of anti-MRSA agents increases, so does the need to identify which are best for the large variety of infections included in the group of cSSSIs. This is particular true for infections occurring in orthopaedic patients where poorly vascularised tissue, trauma or implanted prosthetic material, pose specific challenges.
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Affiliation(s)
- M H Wilcox
- Department of Microbiology, Leeds Teaching Hospitals and University of Leeds, UK.
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73
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Qiu J, Luo M, Wang J, Dong J, Li H, Leng B, Zhang Q, Dai X, Zhang Y, Niu X, Deng X. Isoalantolactone protects against Staphylococcus aureus pneumonia. FEMS Microbiol Lett 2011; 324:147-55. [DOI: 10.1111/j.1574-6968.2011.02397.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 08/23/2011] [Accepted: 08/24/2011] [Indexed: 12/16/2022] Open
Affiliation(s)
- Jiazhang Qiu
- Key Laboratory of Zoonosis; Ministry of Education; Institute of Zoonosis; College of Animal Science and Veterinary Medicine; Jilin University; Changchun; China
| | - Mingjing Luo
- Key Laboratory of Zoonosis; Ministry of Education; Institute of Zoonosis; College of Animal Science and Veterinary Medicine; Jilin University; Changchun; China
| | - Jianfeng Wang
- Key Laboratory of Zoonosis; Ministry of Education; Institute of Zoonosis; College of Animal Science and Veterinary Medicine; Jilin University; Changchun; China
| | - Jing Dong
- Key Laboratory of Zoonosis; Ministry of Education; Institute of Zoonosis; College of Animal Science and Veterinary Medicine; Jilin University; Changchun; China
| | - Hongen Li
- Key Laboratory of Zoonosis; Ministry of Education; Institute of Zoonosis; College of Animal Science and Veterinary Medicine; Jilin University; Changchun; China
| | - Bingfeng Leng
- Key Laboratory of Zoonosis; Ministry of Education; Institute of Zoonosis; College of Animal Science and Veterinary Medicine; Jilin University; Changchun; China
| | - Qian Zhang
- Key Laboratory of Zoonosis; Ministry of Education; Institute of Zoonosis; College of Animal Science and Veterinary Medicine; Jilin University; Changchun; China
| | - Xiaohan Dai
- Key Laboratory of Zoonosis; Ministry of Education; Institute of Zoonosis; College of Animal Science and Veterinary Medicine; Jilin University; Changchun; China
| | - Yu Zhang
- Key Laboratory of Zoonosis; Ministry of Education; Institute of Zoonosis; College of Animal Science and Veterinary Medicine; Jilin University; Changchun; China
| | - Xiaodi Niu
- College of Quartermaster Technology; Jilin University; Changchun; China
| | - Xuming Deng
- Key Laboratory of Zoonosis; Ministry of Education; Institute of Zoonosis; College of Animal Science and Veterinary Medicine; Jilin University; Changchun; China
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74
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Silva LVD, Araújo MT, Santos KRND, Nunes APF. Evaluation of the synergistic potential of vancomycin combined with other antimicrobial agents against methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus spp strains. Mem Inst Oswaldo Cruz 2011; 106:44-50. [PMID: 21340354 DOI: 10.1590/s0074-02762011000100007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 10/27/2010] [Indexed: 11/22/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative Staphylococcus spp (CNS) are the most common pathogens that cause serious long term infections in patients. Despite the existence of new antimicrobial agents, such as linezolid, vancomycin (VAN) remains the standard therapy for the treatment of infections caused by these multidrug-resistant strains. However, the use of VAN has been associated with a high frequency of therapeutic failures in some clinical scenarios, mainly with decreasing concentration of VAN. This work aims to evaluate the synergic potential of VAN plus sulfamethoxazole/trimethoprim (SXT), VAN plus rifampin (RIF) and VAN plus imipenem (IPM) in sub-minimum inhibitory concentrations against 22 clinical strains of MRSA and CNS. The checkerboard method showed synergism of VAN/RIF and VAN/SXT against two and three of the 22 strains, respectively. The combination of VAN with IPM showed synergistic effects against 21 out of 22 strains by the E-test method. Four strains were analyzed by the time-kill curve method and synergistic activity was observed with VAN/SXT, VAN/RIF and especially VAN/IPM in sub-inhibitory concentrations. It would be interesting to determine if synergy occurs in vivo. Evidence of in vivo synergy could lead to a reduction of the standard VAN dosage or treatment time.
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Affiliation(s)
- Lívia Viganor da Silva
- Laboratório de Resistência Bacteriana, Departamento de Patologia, Universidade Federal do Espírito Santo, Vitória, ES, Brasil
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75
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Neumonía y derrame pleural por Staphylococcus aureus sensible a meticilina productor de leucocidina de Panton-Valentine: muy infrecuente y muy peligroso. An Pediatr (Barc) 2011; 75:82-3. [DOI: 10.1016/j.anpedi.2011.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 01/31/2011] [Accepted: 02/01/2011] [Indexed: 11/20/2022] Open
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76
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Complicated infections with meticillin-resistant Staphylococcus aureus in Hong Kong. J Hosp Infect 2011; 78:71-2. [DOI: 10.1016/j.jhin.2010.11.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Accepted: 11/25/2010] [Indexed: 11/22/2022]
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Drebes J, Perbandt M, Wrenger C, Betzel C. Purification, crystallization and preliminary X-ray diffraction analysis of ThiM from Staphylococcus aureus. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:479-481. [PMID: 21505246 PMCID: PMC3080155 DOI: 10.1107/s1744309111004192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 02/03/2011] [Indexed: 05/30/2023]
Abstract
ThiM [5-(hydroxyethyl)-4-methylthiazole kinase; EC 2.7.1.50] from Staphylococcus aureus is an essential enzyme of thiamine or vitamin B(1) metabolism and has been crystallized by the vapour-diffusion method. The crystals belonged to the primitive space group P1, with unit-cell parameters a = 62.06, b = 62.40, c = 107.82 Å, α = 92.25, β = 91.37, γ = 101.48° and six protomers in the unit cell, corresponding to a packing parameter V(M) of 2.3 Å(3) Da(-1). Diffraction data were collected to 2.1 Å resolution using synchrotron radiation. The phase problem was solved by molecular replacement.
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Affiliation(s)
- Julia Drebes
- Department of Chemistry, c/o DESY, Laboratory for Structural Biology of Infection and Inflammation, University of Hamburg, Building 22A, Notkestrasse 85, D-22603 Hamburg, Germany
- Department of Biochemistry, Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht Strasse 74, D-20359 Hamburg, Germany
| | - Markus Perbandt
- Department of Chemistry, c/o DESY, Laboratory for Structural Biology of Infection and Inflammation, University of Hamburg, Building 22A, Notkestrasse 85, D-22603 Hamburg, Germany
- Department of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Carsten Wrenger
- Department of Biochemistry, Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht Strasse 74, D-20359 Hamburg, Germany
| | - Christian Betzel
- Department of Chemistry, c/o DESY, Laboratory for Structural Biology of Infection and Inflammation, University of Hamburg, Building 22A, Notkestrasse 85, D-22603 Hamburg, Germany
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78
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Subrt N, Mesak LR, Davies J. Modulation of virulence gene expression by cell wall active antibiotics in Staphylococcus aureus. J Antimicrob Chemother 2011; 66:979-84. [PMID: 21393149 DOI: 10.1093/jac/dkr043] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES To investigate the effect of subinhibitory concentrations of cell wall active antibiotics on virulence gene expression and biofilm formation in Staphylococcus aureus Newman and in laboratory strains. METHODS Promoter regions of spa, lukE and agr RNAIII were cloned upstream of a modified luxABCDE reporter. Using disc diffusion assays, the effects of antibiotics were observed on gene expression and quantitative real-time PCR was employed to confirm the results. Assays were performed to measure biofilm formation in wild-type S. aureus and respective spa-deficient and small colony variant mutants in the presence of subinhibitory concentrations of antibiotics. RESULTS Expression of spa and lukE was stimulated by subinhibitory concentrations of penicillin and cefalotin, while agr RNAIII expression was not affected. Denser biofilms were formed by S. aureus Newman and its small colony variant in the presence of subinhibitory concentrations of cefalotin. CONCLUSIONS Subinhibitory concentrations of certain antibiotics have been shown to stimulate virulence gene expression in S. aureus; this may alter the progression of infection and thus render antimicrobial therapy unreliable. The use of appropriate combinations of antibiotics might be an approach to avoiding this situation. Promoter-lux reporters are sensitive tools for studying the modulation of transcription by antibiotic inhibitors, and could be used to predict novel therapeutic combinations for the treatment of infection.
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Affiliation(s)
- Natalia Subrt
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
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79
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Li L, Li Z, Guo N, Jin J, Du R, Liang J, Wu X, Wang X, Liu M, Jin Q, Yu L. Synergistic activity of 1-(1-naphthylmethyl)-piperazine with ciprofloxacin against clinically resistant Staphylococcus aureus, as determined by different methods. Lett Appl Microbiol 2011; 52:372-8. [DOI: 10.1111/j.1472-765x.2011.03010.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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80
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Sianglum W, Srimanote P, Wonglumsom W, Kittiniyom K, Voravuthikunchai SP. Proteome analyses of cellular proteins in methicillin-resistant Staphylococcus aureus treated with rhodomyrtone, a novel antibiotic candidate. PLoS One 2011; 6:e16628. [PMID: 21326597 PMCID: PMC3033880 DOI: 10.1371/journal.pone.0016628] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 01/05/2011] [Indexed: 11/19/2022] Open
Abstract
The ethanolic extract from Rhodomyrtus tomentosa leaf exhibited good antibacterial activities against both methicillin-resistant Staphylococcus aureus (MRSA) and S. aureus ATCC 29213. Its minimal inhibitory concentration (MIC) values ranged from 31.25–62.5 µg/ml, and the minimal bactericidal concentration (MBC) was 250 µg/ml. Rhodomyrtone, an acylphloroglucinol derivative, was 62.5–125 times more potent at inhibiting the bacteria than the ethanolic extract, the MIC and MBC values were 0.5 µg/ml and 2 µg/ml, respectively. To provide insights into antibacterial mechanisms involved, the effects of rhodomyrtone on cellular protein expression of MRSA have been investigated using proteomic approaches. Proteome analyses revealed that rhodomyrtone at subinhibitory concentration (0.174 µg/ml) affected the expression of several major functional classes of whole cell proteins in MRSA. The identified proteins involve in cell wall biosynthesis and cell division, protein degradation, stress response and oxidative stress, cell surface antigen and virulence factor, and various metabolic pathways such as amino acid, carbohydrate, energy, lipid, and nucleotide metabolism. Transmission electron micrographs confirmed the effects of rhodomyrtone on morphological and ultrastructural alterations in the treated bacterial cells. Biological processes in cell wall biosynthesis and cell division were interrupted. Prominent changes including alterations in cell wall, abnormal septum formation, cellular disintegration, and cell lysis were observed. Unusual size and shape of staphylococcal cells were obviously noted in the treated MRSA. These pioneer findings on proteomic profiling and phenotypic features of rhodomyrtone-treated MRSA may resolve its antimicrobial mechanisms which could lead to the development of a new effective regimen for the treatment of MRSA infections.
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Affiliation(s)
- Wipawadee Sianglum
- Department of Microbiology and Natural Products Research Center, Faculty of Science, Prince of Songkla University, Songkla, Thailand
| | - Potjanee Srimanote
- Graduate Study, Faculty of Allied Health Sciences, Thammasat University, Pathumtanee, Thailand
| | - Wijit Wonglumsom
- Department of Clinical Microbiology, Faculty of Medical Technology, Mahidol University, Nakhon Pathom, Thailand
| | - Kanokwan Kittiniyom
- Department of Clinical Microbiology, Faculty of Medical Technology, Mahidol University, Nakhon Pathom, Thailand
| | - Supayang P. Voravuthikunchai
- Department of Microbiology and Natural Products Research Center, Faculty of Science, Prince of Songkla University, Songkla, Thailand
- * E-mail:
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81
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Management of Staphylococcus aureus bacteremia and endocarditis: progresses and challenges. Curr Opin Infect Dis 2010; 23:346-58. [DOI: 10.1097/qco.0b013e32833bcc8a] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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82
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Lynch AS, Abbanat D. New antibiotic agents and approaches to treat biofilm-associated infections. Expert Opin Ther Pat 2010; 20:1373-87. [DOI: 10.1517/13543776.2010.505923] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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83
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Unpredictable effects of rifampin as an adjunctive agent in elimination of rifampin-susceptible and -resistant Staphylococcus aureus strains grown in biofilms. Antimicrob Agents Chemother 2010; 54:3907-12. [PMID: 20606067 DOI: 10.1128/aac.01811-09] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The use of rifampin as an adjunct in biofilm-associated infections is based on the ability to penetrate into biofilms and a presumed activity against dormant bacteria. Yet, its efficacy remains contradictory, and rifampin-resistant strains frequently emerge during therapy. Therefore, the efficacy against rifampin-susceptible and isogenic rifampin-resistant methicillin-susceptible Staphylococcus aureus (MSSA) strains was evaluated. Biofilms were generated under static conditions using MSSA with various genetic backgrounds. Oxacillin alone or with rifampin at various concentrations was subsequently added, and after 24 h biomass and viable cell counts were determined. Upon rifampin addition, interstrain variations in viable count change, ranging from a tendency toward antagonism to synergy, were observed among all strains tested, irrespective of the genetic background of the strain. Similar variations were observed in changes in biomass. The decrease in viable count upon rifampin addition was negatively correlated to formation of large amounts of biomass, since strains embedded by more biomass showed a diminished reduction in viable count. Rifampin (1 microg/ml) as adjunct to oxacillin achieved greater reductions in biomass produced by most rifampin-susceptible isolates, ranging from 17 to 54%, compared to 4% for oxacillin alone. In contrast, rifampin had no additional value in reduction of biomass of isogenic rifampin-resistant mutants. At subinhibitory concentrations of rifampin (0.008 microg/ml), none of the strains tested yielded an extra reduction in biomass that was > or = 40%. In conclusion, the effects of rifampin as adjunct on biomass and viable count were unpredictable, and the use of rifampin against biofilm containing rifampin-resistant strains seems unwarranted.
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84
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Is pyogenic ethmoidal osteitis the cause of complicated rhinosinusitis with subperiosteal orbital abscess? Eur Arch Otorhinolaryngol 2010; 267:1231-7. [DOI: 10.1007/s00405-009-1197-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2009] [Accepted: 12/29/2009] [Indexed: 01/27/2023]
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