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Duncan LR, Sader HS, Smart JI, Flamm RK, Mendes RE. Telavancin activity in vitro tested against a worldwide collection of Gram-positive clinical isolates (2014). J Glob Antimicrob Resist 2017; 10:271-276. [DOI: 10.1016/j.jgar.2017.03.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 03/30/2017] [Indexed: 10/19/2022] Open
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Efficacy of Telavancin Alone and in Combination with Ampicillin in a Rat Model of Enterococcus faecalis Endocarditis. Antimicrob Agents Chemother 2017; 61:AAC.02489-16. [PMID: 28320712 DOI: 10.1128/aac.02489-16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 03/06/2017] [Indexed: 11/20/2022] Open
Abstract
We first assessed telavancin (TLV) pharmacokinetics in rats after a single subcutaneous dose of 35 mg/kg of body weight. The pharmacokinetic data were used to predict a TLV dose that simulates human exposure, and the efficacy of TLV was then evaluated using a TLV dose of 21 mg/kg every 12 h against Enterococcus faecalis OG1RF (TLV MIC of 0.06 μg/ml) in a rat endocarditis model with an indwelling catheter. Therapy was given for 3 days with TLV, daptomycin (DAP), or ampicillin (AMP) monotherapy and with combinations of TLV plus AMP, AMP plus gentamicin (GEN), and AMP plus ceftriaxone (CRO); rats were sacrificed 24 h after the last dose. Antibiotics were given to simulate clinically relevant concentrations or as used in other studies. TLV treatment resulted in a significant decrease in bacterial burden (CFU per gram) in vegetations from 6.0 log10 at time 0 to 3.1 log10 after 3 days of therapy. Bacterial burdens in vegetations were also significantly lower in the TLV-treated rats than in the AMP (P = 0.0009)- and AMP-plus-GEN (P = 0.035)-treated rats but were not significantly different from that of the AMP-plus-CRO-treated rats. Bacterial burdens from vegetations in TLV monotherapy and TLV-plus-AMP-and-DAP groups were similar to each other (P ≥ 0.05). Our data suggest that further study of TLV as a therapeutic alternative for deep-seated infections caused by vancomycin-susceptible E. faecalis is warranted.
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Das B, Sarkar C, Das D, Gupta A, Kalra A, Sahni S. Telavancin: a novel semisynthetic lipoglycopeptide agent to counter the challenge of resistant Gram-positive pathogens. Ther Adv Infect Dis 2017; 4:49-73. [PMID: 28634536 PMCID: PMC5467880 DOI: 10.1177/2049936117690501] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Telavancin (TD-6424), a semisynthetic lipoglycopeptide vancomycin-derivative, is a novel antimicrobial agent developed by Theravance for overcoming resistant Gram-positive bacterial infections, specifically methicillin-resistant Staphylococcus aureus (MRSA). The US Food and Drug Administration (USFDA) had approved telavancin in 2009 for the treatment of complicated skin and skin structure infections (cSSSIs) caused by Gram-positive bacteria, including MRSA (S. aureus, Streptococcus agalactiae, Streptococcus pyogenes, Streptococcus anginosus group, or Enterococcus faecalis). Telavancin has two proposed mechanisms of action. In vitro, telavancin has a rapid, concentration-dependent bactericidal effect, due to disruption of cell membrane integrity. Telavancin has demonstrable in vitro activity against aerobic and anaerobic Gram-positive bacteria. Telavancin and vancomycin have similar spectra of activity. Gram-negative bacteria are usually non-susceptible to telavancin. Telavancin has been successfully tested in various animal models of bacteremia, endocarditis, meningitis, and pneumonia. Phase II Telavancin versus Standard Therapy for Treatment of Complicated Skin and Soft-Tissue Infections due to Gram-Positive Bacteria (FAST 1 and FAST 2) and phase III [Assessment of Telavancin in Complicated Skin and Skin Structure Infections 1 (ATLAS 1 and ATLAS 2)] clinical trials have been conducted for evaluating telavancin's efficacy and safety in cSSSIs. Phase III clinical trials have been carried out for evaluating telavancin's safety and efficacy in nosocomial pneumonia [Assessment of Telavancin for Treatment of Hospital acquired Pneumonia 1 and 2 (ATTAIN 1 and ATTAIN 2)]. A phase II randomized, double-blind, clinical trial has been carried out for evaluating telavancin's safety and efficacy in uncomplicated S. aureus bacteremia [Telavancin for Treatment of Uncomplicated S. aureus Bacteremia (ASSURE)]. Pacemaker lead-related infective endocarditis due to a vancomycin intermediate S. aureus (VISA) strain (non-daptomycin susceptible) was successfully treated with parenteral telavancin for 8 weeks. Telavancin extensively binds to serum albumin (~93%) and has a relatively small volume of distribution. Telavancin is not biotransformed by any cytochrome P450 microsomal enzymes and excreted mainly in the urine. Though well-tolerated, worrisome adverse effects, including renal dysfunction and QTc prolongation are of potential concern. Given its extensive binding to plasma proteins, long half-life, and a long post-antibiotic effect, it represents a promising addition to the therapeutic armamentarium in combating infections caused by resistant Gram-positive pathogens, namely, MRSA.
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Affiliation(s)
- Biswadeep Das
- Department of Pharmacology, All India Institute of Medical Sciences (AIIMS) Rishikesh, Rishikesh, India
| | - Chayna Sarkar
- Department of Pharmacology & Clinical Pharmacology, North Eastern Indira Gandhi Regional Institute of Health & Medical Sciences (NEIGRIHMS) Shillong, Shillong, India
| | - Debasmita Das
- Department of Computer Science & Engineering, Faculty of Engineering, Manipal University Jaipur, Dehmi Kalan, Jaipur Ajmer Expressway, Rajasthan, India
| | - Amit Gupta
- Department of Surgery, All India Institute of Medical Sciences (AIIMS) Rishikesh, Rishikesh, India
| | - Arnav Kalra
- Department of Pharmacology, All India Institute of Medical Sciences (AIIMS) Rishikesh, Rishikesh, India
| | - Shubham Sahni
- Department of Pharmacology, All India Institute of Medical Sciences (AIIMS) Rishikesh, Rishikesh, India
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Telavancin Is Active against Experimental Aortic Valve Endocarditis Caused by Daptomycin- and Methicillin-Resistant Staphylococcus aureus Strains. Antimicrob Agents Chemother 2017; 61:AAC.01877-16. [PMID: 27872064 DOI: 10.1128/aac.01877-16] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/06/2016] [Indexed: 11/20/2022] Open
Abstract
We compared the efficacy of telavancin (TLV) and daptomycin (DAP) in an experimental rabbit endocarditis model caused by two clinically derived daptomycin-resistant (DAPr) methicillin-resistant Staphylococcus aureus (MRSA) strains. TLV treatment significantly reduced MRSA densities in all target tissues and increased the percentage of these organs rendered culture negative compared to those with the untreated control or DAP-treated animals. These results demonstrate that TLV has potent in vivo efficacy against DAPr MRSA isolates in this invasive endovascular infection model.
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Comparative Efficacies of Tedizolid Phosphate, Linezolid, and Vancomycin in a Murine Model of Subcutaneous Catheter-Related Biofilm Infection Due to Methicillin-Susceptible and -Resistant Staphylococcus aureus. Antimicrob Agents Chemother 2016; 60:5092-6. [PMID: 27297485 DOI: 10.1128/aac.00880-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 06/07/2016] [Indexed: 12/17/2022] Open
Abstract
Tedizolid, a novel oxazolidinone, exhibits bacteriostatic activity through inhibition of protein synthesis. The efficacies of tedizolid, linezolid, and vancomycin were compared in a murine catheter-related biofilm infection caused by methicillin-susceptible and -resistant Staphylococcus aureus (MSSA and MRSA, respectively) strains engineered for bioluminescence. We observed significantly improved efficacy in terms of decreased S. aureus densities and bioluminescent signals in the tedizolid-treated group versus the linezolid- and vancomycin-treated groups in the model of infection caused by the MSSA and MRSA strains.
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Xiong YQ, Abdelhady W, Tang C'G, Bayer AS. Comparative efficacy of telavancin and daptomycin in experimental endocarditis due to multi-clonotype MRSA strains. J Antimicrob Chemother 2016; 71:2890-4. [PMID: 27353467 DOI: 10.1093/jac/dkw249] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 05/24/2016] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND MRSA strains of clonal complexes (CCs) 5, 8, 30 and 45 are leading causes of complicated endovascular infections associated with suboptimal clinical outcomes. Telavancin is a novel anti-MRSA agent that both inhibits bacterial cell wall synthesis and disrupts membranes by depolarization. METHODS In this study, we compared the in vitro susceptibility and in vivo efficacy of telavancin versus daptomycin in an experimental rabbit infective endocarditis (IE) model caused by four MRSA strains representing each of the above CC types. RESULTS All study strains were susceptible to telavancin (MICs of ≤0.12 mg/L) and daptomycin (MICs of ≤0.5 mg/L). In vitro time-kill analyses revealed that supra-MIC levels of telavancin were effective at preventing regrowth at 24 h of incubation. In the IE animal model for all CC types, treatment with telavancin produced significantly greater reductions in MRSA counts as compared with daptomycin-treated animals in all target tissues. Moreover, telavancin-treated animals had a significantly higher percentage of sterile tissue cultures versus daptomycin-treated animals (e.g. 78%-100% versus 0% sterile vegetations and 100% versus 0%-11% sterile kidneys and spleen, in the telavancin- and daptomycin-treated animals, respectively). CONCLUSIONS These results suggest that telavancin exhibits significantly greater efficacies versus daptomycin in treating experimental IE caused by MRSA clinical isolates across four common CC types.
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Affiliation(s)
- Yan Q Xiong
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Wessam Abdelhady
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Chieh 'Genna' Tang
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Arnold S Bayer
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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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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Wenzler E, Rodvold KA. Telavancin: The Long and Winding Road From Discovery to Food and Drug Administration Approvals and Future Directions. Clin Infect Dis 2015; 61 Suppl 2:S38-47. [DOI: 10.1093/cid/civ522] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Chan C, Hardin TC, Smart JI. A review of telavancin activity in in vitro biofilms and animal models of biofilm-associated infections. Future Microbiol 2015; 10:1325-38. [DOI: 10.2217/fmb.15.53] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
ABSTRACT Tissue- and device-associated biofilm infections are important medical problems. These infections are difficult to treat due to a high-level of tolerance to antibiotics. Telavancin has been studied in several in vitro biofilm models and has demonstrated efficacy against staphylococcal and enterococcal-associated biofilm infections, including those formed by methicillin-resistant Staphylococcus aureus. Telavancin was effective against the difficult-to-treat vancomycin- and glycopeptide-intermediate strains of S. aureus in these models. Furthermore, the efficacy of telavancin has been evaluated in several biofilm-related in vivo models, including osteomyelitis, endocarditis and device-associated infections in rabbits. Overall, telavancin exhibited similar or greater efficacy than vancomycin and other comparators in these animal models and maintained activity against vancomycin-intermediate and daptomycin nonsusceptible strains of S. aureus.
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Affiliation(s)
- Cynthia Chan
- Theravance Biopharma US, Inc. 901 Gateway Blvd, South San Francisco, CA 94080, USA
| | - Thomas C Hardin
- Theravance Biopharma US, Inc. 901 Gateway Blvd, South San Francisco, CA 94080, USA
| | - Jennifer I Smart
- Theravance Biopharma US, Inc. 901 Gateway Blvd, South San Francisco, CA 94080, USA
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Telavancin demonstrates activity against methicillin-resistant Staphylococcus aureus isolates with reduced susceptibility to vancomycin, daptomycin, and linezolid in broth microdilution MIC and one-compartment pharmacokinetic/pharmacodynamic models. Antimicrob Agents Chemother 2015; 59:5529-34. [PMID: 26124162 DOI: 10.1128/aac.00773-15] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 06/20/2015] [Indexed: 11/20/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) isolates have arisen with reduced susceptibility to several anti-MRSA agents. Telavancin (TLV), a novel anti-MRSA agent, retains low MICs against these organisms. Our objective was to determine the MICs for TLV, daptomycin (DAP), vancomycin (VAN), and linezolid (LZD) against daptomycin-nonsusceptible (DNS) S. aureus, vancomycin-intermediate S. aureus (VISA), heteroresistant VISA (hVISA), and linezolid-resistant (LZD(r)) S. aureus. We also evaluated these agents against each phenotype in pharmacokinetic/pharmacodynamic (PK/PD) models. Seventy DNS, 100 VISA, 180 hVISA, and 25 LZD(r) MRSA isolates were randomly selected from our library and tested to determine their MICs against TLV, DAP, VAN, and LZD via broth microdilution and a Trek panel. Four isolates were randomly selected for 168-h in vitro models to evaluate treatment with TLV at 10 mg/kg of body weight/day, DAP at 10 mg/kg/day, VAN at 1 g every 12 h (q12h), and LZD at 600 mg q12h. The MIC50/90 for TLV, DAP, VAN, and LZD against 70 DNS S. aureus isolates were 0.06/0.125 μg/ml, 2/4 μg/ml, 1/2 μg/ml, and 2/2 μg/ml, respectively. Against 100 VISA isolates, the MIC50/90 were 0.06/0.125 μg/ml, 1/1 μg/ml, 4/8 μg/ml, and 1/2 μg/ml, respectively. Against 170 hVISA isolates, the MIC50/90 were 0.06/0.125 μg/ml, 0.5/1 μg/ml, 1/2 μg/ml, and 1/2 μg/ml, respectively. Against 25 LZD(r) isolates, the MIC50/90 were 0.03/0.06 μg/ml, 1/1 μg/ml, 2/2 μg/ml, and 8/8 μg/ml, respectively. The TLV MIC was >0.125 μg/ml for 10/365 (2.7%) isolates. In PK/PD models, TLV was universally bactericidal at 168 h and statistically superior to all antibiotics against DNS S. aureus strain R2334. These data further establish the potency of TLV against resistant MRSA. The model data demonstrate in vitro bactericidal activity of TLV against hVISA, VISA, DNS S. aureus, and LZD(r) S. aureus strains. Further clinical research is warranted.
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Corey GR, Rubinstein E, Stryjewski ME, Bassetti M, Barriere SL. Potential role for telavancin in bacteremic infections due to gram-positive pathogens: focus on Staphylococcus aureus. Clin Infect Dis 2015; 60:787-96. [PMID: 25472944 PMCID: PMC4329924 DOI: 10.1093/cid/ciu971] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Staphylococcus aureus bacteremia (SAB) is one of the most common serious bacterial infections and the most frequent invasive infection due to methicillin-resistant S. aureus (MRSA). Treatment is challenging, particularly for MRSA, because of limited treatment options. Telavancin is a bactericidal lipoglycopeptide antibiotic that is active against a range of clinically relevant gram-positive pathogens including MRSA. In experimental animal models of sepsis telavancin was shown to be more effective than vancomycin. In clinically evaluable patients enrolled in a pilot study of uncomplicated SAB, cure rates were 88% for telavancin and 89% for standard therapy. Among patients with infection due to only gram-positive pathogens enrolled in the 2 phase 3 studies of telavancin for treatment of hospital-acquired pneumonia, cure rates for those with bacteremic S. aureus pneumonia were 41% (9/22, telavancin) and 40% (10/25, vancomycin) with identical mortality rates. These data support further evaluation of telavancin in larger, prospective studies of SAB.
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Affiliation(s)
- G Ralph Corey
- Department of Medicine, Duke Clinical Research Institute, Durham, North Carolina
| | - Ethan Rubinstein
- Section of Infectious Diseases, Department of Internal Medicine and Medical Microbiology, University of Manitoba, Winnipeg, Canada
| | - Martin E Stryjewski
- Department of Medicine, Section of Infectious Diseases, Centro de Educación Médica e Investigaciones Clínicas 'Norberto Quirno' (CEMIC), Ciudad Autónoma de Buenos Aires, Argentina
| | - Matteo Bassetti
- Infectious Diseases Division, Santa Maria Misericordia University Hospital, Piazzale Santa Maria della Misericordia, Udine, Italy
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Mendes RE, Farrell DJ, Sader HS, Streit JM, Jones RN. Update of the telavancin activity in vitro tested against a worldwide collection of Gram-positive clinical isolates (2013), when applying the revised susceptibility testing method. Diagn Microbiol Infect Dis 2014; 81:275-9. [PMID: 25618421 DOI: 10.1016/j.diagmicrobio.2014.12.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 12/18/2014] [Accepted: 12/21/2014] [Indexed: 11/30/2022]
Abstract
A revised broth microdilution susceptibility testing method for telavancin was approved by the Food and Drug Administration (FDA). Telavancin activity was assessed against Gram-positive pathogens collected worldwide (2013) using the revised method. A total of 12,346 isolates from 90 sites were included as part of the Telavancin International Surveillance Program for the Americas, Europe, and Asia-Pacific. Telavancin had MIC50 and MIC90 values of 0.03 and 0.06 μg/mL, respectively, against staphylococci, regardless of methicillin susceptibility, and inhibited all Staphylococcus aureus at ≤0.12 μg/mL (revised FDA breakpoint). Telavancin was 8-fold more active than daptomycin (MIC50/90, 0.25/0.5 μg/mL) and 16- to 32-fold more active than vancomycin (MIC50/90, 1/1 μg/mL) and linezolid (MIC50/90, 1/1 μg/mL) against methicillin-resistant S. aureus. All 692 vancomycin-susceptible Enterococcus faecalis were inhibited by telavancin (MIC50/90, 0.12/0.12 μg/mL) at ≤0.25 μg/mL (FDA breakpoint), except for 1 strain (MIC, 0.5 μg/mL). All Enterococcus faecium and E. faecalis with telavancin MIC values of ≥0.5 and ≥1 μg/mL, respectively, had a VanA phenotype. A comparison data analysis based on the MIC90 demonstrated that telavancin was at least 8-fold more potent than comparators against vancomycin-susceptible enterococci. Streptococci showed telavancin MIC50 values of ≤0.015 μg/mL, except for Streptococcus agalactiae (MIC50, 0.03 μg/mL). These in vitro results obtained by the recently approved susceptibility testing method establish a new benchmark of telavancin activity worldwide.
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Hegde SS, Janc JW. Efficacy of telavancin, a lipoglycopeptide antibiotic, in experimental models of Gram-positive infection. Expert Rev Anti Infect Ther 2014; 12:1463-75. [DOI: 10.1586/14787210.2014.979789] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Burke SL, Rose WE. New pharmacological treatments for methicillin-resistantStaphylococcus aureusinfections. Expert Opin Pharmacother 2014; 15:483-91. [DOI: 10.1517/14656566.2014.876991] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Role of the LytSR two-component regulatory system in adaptation to cationic antimicrobial peptides in Staphylococcus aureus. Antimicrob Agents Chemother 2013; 57:3875-82. [PMID: 23733465 DOI: 10.1128/aac.00412-13] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Many host defense cationic antimicrobial peptides (HDPs) perturb the staphylococcal cell membrane (CM) and alter transmembrane potential (ΔΨ) as key parts of their lethal mechanism. Thus, a sense-response system for detecting and mediating adaptive responses to such stresses could impact organism survival; the Staphylococcus aureus LytSR two-component regulatory system (TCRS) may serve as such a ΔΨ sensor. One well-known target of this system is the lrgAB operon, which, along with the related cidABC operon, has been shown to be a regulator in the control of programmed cell death and lysis. We used an isogenic set of S. aureus strains: (i) UAMS-1, (ii) its isogenic ΔlytS and ΔlrgAB mutants, and (iii) plasmid-complemented ΔlytSR and ΔlrgAB mutants. The ΔlytS strain displayed significantly increased in vitro susceptibilities to all HDPs tested (neutrophil-derived human neutrophil peptide 1 [hNP-1], platelet-derived thrombin-induced platelet microbicidal proteins [tPMPs], and the tPMP-mimetic peptide RP-1), as well as to calcium-daptomycin (DAP), a cationic antimicrobial peptide (CAP). In contrast, the ΔlrgAB strain exhibited no significant changes in susceptibilities to these cationic peptides, indicating that although lytSR positively regulates transcription of lrgAB, increased HDP/CAP susceptibilities in the ΔlytS mutant were lrgAB independent. Further, parental UAMS-1 (but not the ΔlytS mutant) became more resistant to hNP-1 and DAP following pretreatment with carbonyl cyanide m-chlorophenylhydrazone (CCCP) (a CM-depolarizing agent). Of note, lytSR-dependent survival against CAP/HDP killing was not associated with changes in either surface positive charge, expression of mprF and dlt, or CM fluidity. The ΔlytS strain (but not the ΔlrgAB mutant) displayed a significant reduction in target tissue survival in an endocarditis model during DAP treatment. Collectively, these results suggest that the lytSR TCRS plays an important role in adaptive responses of S. aureus to CM-perturbing HDPs/CAPs, likely by functioning as a sense-response system for detecting subtle changes in ΔΨ.
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EI Sakka N, Gould IM. Current challenges in treating methicillin-resistant Staphylococcus aureus: what are the options? Microb Drug Resist 2013. [DOI: 10.2217/ebo.12.485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Noha EI Sakka
- Noha El Sakka is a medical microbiology specialty Trainee at Aberdeen Royal Infirmary (UK). She graduated from Alexandria School of Medicine (Egypt), where she obtained her MD in clinical pathology. She completed her PhD in molecular biology at the University of Aberdeen (UK). Her area of interest is Staphylococcus aureus bacteremias
| | - Ian M Gould
- Noha El Sakka is a medical microbiology specialty Trainee at Aberdeen Royal Infirmary (UK). She graduated from Alexandria School of Medicine (Egypt), where she obtained her MD in clinical pathology. She completed her PhD in molecular biology at the University of Aberdeen (UK). Her area of interest is Staphylococcus aureus bacteremias
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Bayer AS, Schneider T, Sahl HG. Mechanisms of daptomycin resistance in Staphylococcus aureus: role of the cell membrane and cell wall. Ann N Y Acad Sci 2013; 1277:139-58. [PMID: 23215859 PMCID: PMC3556211 DOI: 10.1111/j.1749-6632.2012.06819.x] [Citation(s) in RCA: 220] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The bactericidal, cell membrane-targeting lipopeptide antibiotic daptomycin (DAP) is an important agent in treating invasive Staphylococcus aureus infections. However, there have been numerous recent reports of development of daptomycin resistance (DAP-R) during therapy with this agent. The mechanisms of DAP-R in S. aureus appear to be quite diverse. DAP-R strains often exhibit progressive accumulation of single nucleotide polymorphisms in the multipeptide resistance factor gene (mprF) and the yycFG components of the yycFGHI operon. Both loci are involved in key cell membrane (CM) events, with mprF being responsible for the synthesis and outer CM translocation of the positively charged phospholipid, lysyl-phosphotidylglycerol (L-PG), while the yyc operon is involved in the generalized response to stressors such as antimicrobials. In addition, other perturbations of the CM have been identified in DAP-R strains, including extremes in CM order, resistance to CM depolarization and permeabilization, and reduced surface binding of DAP. Moreover, modifications of the cell wall (CW) appear to also contribute to DAP-R, including enhanced expression of the dlt operon (involved in d-alanylation of CW teichoic acids) and progressive CW thickening.
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Affiliation(s)
- Arnold S Bayer
- Los Angeles Biomedical Research Institute at Harbor-University of California, Los Angeles, Torrance, California 905092, USA.
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