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Ersoy SC, Proctor RA, Rose WE, Abdelhady W, Fan SH, Madrigal SL, Elsayed AM, Chambers HF, Sobral RG, Bayer AS. Sensitizing methicillin-resistant Staphylococcus aureus (MRSA) to cefuroxime: the synergic effect of bicarbonate and the wall teichoic acid inhibitor ticlopidine. Antimicrob Agents Chemother 2024; 68:e0162723. [PMID: 38349162 PMCID: PMC10916381 DOI: 10.1128/aac.01627-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 01/18/2024] [Indexed: 03/07/2024] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) strains are a major challenge for clinicians due, in part, to their resistance to most β-lactams, the first-line treatment for methicillin-susceptible S. aureus. A phenotype termed "NaHCO3-responsiveness" has been identified, wherein many clinical MRSA isolates are rendered susceptible to standard-of-care β-lactams in the presence of physiologically relevant concentrations of NaHCO3, in vitro and ex vivo; moreover, such "NaHCO3-responsive" isolates can be effectively cleared by β-lactams from target tissues in experimental infective endocarditis (IE). One mechanistic impact of NaHCO3 exposure on NaHCO3-responsive MRSA is to repress WTA synthesis. This NaHCO3 effect mimics the phenotype of tarO-deficient MRSA, including sensitization to the PBP2-targeting β-lactam, cefuroxime (CFX). Herein, we further investigated the impacts of NaHCO3 exposure on CFX susceptibility in the presence and absence of a WTA synthesis inhibitor, ticlopidine (TCP), in a collection of clinical MRSA isolates from skin and soft tissue infections (SSTI) and bloodstream infections (BSI). NaHCO3 and/or TCP enhanced susceptibility to CFX in vitro, by both minimum inhibitor concentration (MIC) and time-kill assays, as well as in an ex vivo simulated endocarditis vegetations (SEV) model, in NaHCO3-responsive MRSA. Furthermore, in experimental IE (presumably in the presence of endogenous NaHCO3), pre-exposure to TCP prior to infection sensitized the NaHCO3-responsive MRSA strain (but not the non-responsive strain) to enhanced clearances by CFX in target tissues. These data support the notion that NaHCO3 is acting similarly to WTA synthesis inhibitors, and that such inhibitors have potential translational applications in the treatment of certain MRSA strains in conjunction with specific β-lactam agents.
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Affiliation(s)
- Selvi C. Ersoy
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Richard A. Proctor
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Warren E. Rose
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Wessam Abdelhady
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Sook-Ha Fan
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
| | | | - Ahmed M. Elsayed
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Henry F. Chambers
- University of California-San Francisco School of Medicine, San Francisco, California, USA
| | - Rita G. Sobral
- Laboratory of Molecular Microbiology of Bacterial Pathogens, UCIBIO, Applied Molecular Biosciences Unit, Department of Life Sciences, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
| | - Arnold S. Bayer
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
- David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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2
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Morán-Díaz JR, Neveros-Juárez F, Arellano-Mendoza MG, Quintana-Zavala D, Lara-Salazar O, Trujillo-Ferrara JG, Guevara-Salazar JA. QSAR analysis of five generations of cephalosporins to establish the structural basis of activity against methicillin-resistant and methicillin-sensitive Staphylococcus aureus. Mol Divers 2023:10.1007/s11030-023-10730-7. [PMID: 37733244 DOI: 10.1007/s11030-023-10730-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 09/08/2023] [Indexed: 09/22/2023]
Abstract
Solving the worldwide problem of growing bacterial drug resistance will require a short-run and medium-term strategy. Structure-activity relationship (SAR) and quantitative SAR (QSAR) analyses have recently been utilized to reveal the molecular basis of the antibacterial activity and antibacterial spectrum of penicillins, the use of which is no longer solely empirical. Likewise, a more rational drug design can be achieved with cephalosporins, the largest group of β-lactam antibiotics. The current contribution aimed to establish the molecular and physicochemical basis of the antibacterial activity of five generations of cephalosporins on methicillin-sensitive (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA). With SAR and QSAR analyses, the molecular portions that provide essential and additional antibacterial activity were identified. The substitutions with greater volume and polarity on the R2 side chain of the cephem nucleus increase potency on MSSA. The best effect is produced by substitutions with polar nitrogen atoms at the alpha-carbon (Cα). Substitutions with greater volume and polarity on the R1 side chain further enhance antibacterial activity. In contrast, the effect against MRSA seems to be independent of any substitution on R2 or at the Cα, while depending on the accessory portions with greater volume and polarity on R1.
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Affiliation(s)
- Jessica R Morán-Díaz
- Organic Chemistry Laboratory. Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, Instituto Politécnico Nacional, Legaria No. 694, C.P. 11500, Mexico City, Mexico
| | - Francisco Neveros-Juárez
- Department of Pharmacology, Biochemistry and Section of Postgraduate Studies and Research. Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, S/N, Col. Santo Tomás, Alcaldía Miguel Hidalgo, C.P. 11340, Mexico City, Mexico
| | - Mónica Griselda Arellano-Mendoza
- Chronic-Degenerative Diseases Laboratory and Section of Postgraduate Studies and Research. Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, S/N, Col. Santo Tomás, Alcaldía Miguel Hidalgo, C.P. 11340, Mexico City, Mexico
| | - Delia Quintana-Zavala
- Organic Chemistry Laboratory. Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Unidad Legaria, Instituto Politécnico Nacional, Legaria No. 694, C.P. 11500, Mexico City, Mexico
| | - Omar Lara-Salazar
- Disruptive Films S.A. de C.V, Department of Analysis and Data Science, Dr. Andrade 458, Col. Atenor Salas, C.P. 03010, Mexico City, Mexico
| | - José Guadalupe Trujillo-Ferrara
- Department of Pharmacology, Biochemistry and Section of Postgraduate Studies and Research. Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, S/N, Col. Santo Tomás, Alcaldía Miguel Hidalgo, C.P. 11340, Mexico City, Mexico
| | - J Alberto Guevara-Salazar
- Department of Pharmacology, Biochemistry and Section of Postgraduate Studies and Research. Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, S/N, Col. Santo Tomás, Alcaldía Miguel Hidalgo, C.P. 11340, Mexico City, Mexico.
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3
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Lefèvre B, Hoen B, Goehringer F, Sime WN, Aissa N, Alauzet C, Jeanmaire E, Hénard S, Filippetti L, Selton-Suty C, Agrinier N. Antistaphylococcal penicillins vs. cefazolin in the treatment of methicillin-susceptible Staphylococcus aureus infective endocarditis: a quasi-experimental monocentre study. Eur J Clin Microbiol Infect Dis 2021; 40:2605-2616. [PMID: 34383175 DOI: 10.1007/s10096-021-04313-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 07/09/2021] [Indexed: 10/20/2022]
Abstract
Whether cefazolin is as effective and safer than antistaphylococcal penicillins (ASPs) for the treatment of methicillin-susceptible Staphylococcus aureus (MSSA) infective endocarditis (IE) is still debated in the absence of a randomized controlled trial. In this quasi-experimental study, we aimed to assess the effectiveness and safety of these two treatments in MSSA-IE, using the ASPs nationwide shortage in April 2016 as a unique opportunity to overcome the indication bias associated with observational studies. In this single-centre study, we compared patients with Duke-Li definite MSSA-IE treated with ASPs from January 2015 to March 2016 versus those treated with cefazolin from April 2016 to December 2018, when ASPs were not available. Effectiveness outcome was 90-day all-cause mortality. Safety outcomes included significant decrease in GFR and significant increase in serum liver enzymes. Logrank test was used to compare survival rates. Of 73 patients with MSSA-IE, 35 and 38 were treated with ASPs and cefazolin, respectively. Baseline patients' characteristics (demography, native or prosthetic valve IE, clinical characteristics, cardiac and septic complications) were similar between groups. Ninety-day all-cause mortality was 28.6% and 21.1%, in patients treated with ASPs and cefazolin, respectively (logrank p = 0.5727). There was no difference between groups for incident renal or liver toxicity events: acute kidney injury 45.7% vs. 44.7% (p = 0.933), increased ALT 5.7% vs. 13.2% (p = 0.432), bilirubin increase 5.7% vs. 10.5% (p = 0.676), in ASPs vs. cefazolin groups, respectively. In this quasi-experimental, effectiveness and safety did not statistically differ between ASPs and cefazolin for MSSA-IE treatment.
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Affiliation(s)
- B Lefèvre
- Infectious and Tropical Diseases, CHRU-Nancy, Université de Lorraine, 54000, Nancy, France. .,APEMAC, Université de Lorraine, 54000, Nancy, France. .,Service Maladies Infectieuses Et Tropicales, Bâtiment Des Spécialités Médicales, Hôpitaux de Brabois, Centre Hospitalier Régional Universitaire de Nancy, Route de Morvan, 54511, Vandœuvre-Lès-Nancy Cedex, France.
| | - B Hoen
- Infectious and Tropical Diseases, CHRU-Nancy, Université de Lorraine, 54000, Nancy, France
| | - F Goehringer
- Infectious and Tropical Diseases, CHRU-Nancy, Université de Lorraine, 54000, Nancy, France
| | - W Ngueyon Sime
- INSERM, CIC-EC, Epidémiologie clinique, CHRU-Nancy, 54000, Nancy, France
| | - N Aissa
- Service de Microbiologie, CHRU-Nancy, 54000, Nancy, France
| | - C Alauzet
- Service de Microbiologie, CHRU-Nancy, 54000, Nancy, France.,SIMPA, Université de Lorraine, 54000, Nancy, France
| | - E Jeanmaire
- Infectious and Tropical Diseases, CHRU-Nancy, Université de Lorraine, 54000, Nancy, France
| | - S Hénard
- Infectious and Tropical Diseases, CHRU-Nancy, Université de Lorraine, 54000, Nancy, France
| | | | | | - N Agrinier
- APEMAC, Université de Lorraine, 54000, Nancy, France.,INSERM, CIC-EC, Epidémiologie clinique, CHRU-Nancy, 54000, Nancy, France
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Hwang JH, Lee SY, Choi J. Microscopic Analysis of Bacterial Inoculum Effect Using Micropatterned Biochip. Antibiotics (Basel) 2021; 10:antibiotics10030300. [PMID: 33805824 PMCID: PMC7998646 DOI: 10.3390/antibiotics10030300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/10/2021] [Accepted: 03/12/2021] [Indexed: 12/05/2022] Open
Abstract
Antimicrobial resistance has become a major problem in public health and clinical environments. Against this background, antibiotic susceptibility testing (AST) has become necessary to cure diseases in an appropriate and timely manner as it indicates the necessary concentration of antibiotics. Recently, microfluidic based rapid AST methods using microscopic analysis have been shown to reduce the time needed for the determination of the proper antibiotics. However, owing to the inoculum effect, the accurate measurement of the minimal inhibitory concentration (MIC) is difficult. We tested four standard bacteria: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis, against five different antibiotics: piperacillin, cefotaxime, amikacin, levofloxacin, and ampicillin. The results showed that overall, the microfluidic system has a similar inoculum effect compared to the conventional AST method. However, due to the different testing conditions and determination protocols of the growth of the microfluidic based rapid AST, a few results are not identical to the conventional methods using optical density. This result suggests that microfluidic based rapid AST methods require further research on the inoculum effect for practical use in hospitals and can then be used for effective antibiotic prescriptions.
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Affiliation(s)
- Jung Ho Hwang
- Department of Electrical and Computer Engineering, Undergraduate School, Michigan State University, 426 Auditorium Road, East Lansing, MI 48824, USA;
| | - Sang Young Lee
- Department of Mechanical Engineering, Undergraduate School, Kookmin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul 02707, Korea;
| | - Jungil Choi
- School of Mechanical Engineering, Kookmin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul 02707, Korea
- Correspondence: ; Tel.: +82-2-910-4684
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Karchmer AW. Definitive Treatment for Methicillin-Susceptible Staphylococcus aureus Bacteremia: Data Versus a Definitive Answer? Clin Infect Dis 2019; 65:107-109. [PMID: 28379366 DOI: 10.1093/cid/cix288] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 03/28/2017] [Indexed: 11/13/2022] Open
Affiliation(s)
- Adolf W Karchmer
- Beth Israel Deaconess Medical Center, Division of Infectious Diseases, Harvard Medical School, Boston, Massachusetts
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6
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Revest M, Camou F, Senneville E, Caillon J, Laurent F, Calvet B, Feugier P, Batt M, Chidiac C. Medical treatment of prosthetic vascular graft infections: Review of the literature and proposals of a Working Group. Int J Antimicrob Agents 2015; 46:254-65. [PMID: 26163735 DOI: 10.1016/j.ijantimicag.2015.04.014] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 04/07/2015] [Accepted: 04/21/2015] [Indexed: 02/07/2023]
Abstract
More than 400000 vascular grafts are inserted annually in the USA. Graft insertion is complicated by infection in 0.5-4% of cases. Vascular graft infections (VGIs) are becoming one of the most frequent prosthesis-related infections and are associated with considerable mortality, ranging from 10 to 25% within 30 days following the diagnosis. Treatment of VGI is based on urgent surgical removal of the infected graft followed by prolonged antibiotherapy. Data regarding the best antibiotherapy to use are lacking since no well designed trial to study antimicrobial treatment of VGI exists. Moreover, since VGIs demonstrate very specific pathophysiology, guidelines on other material-related infections or infective endocarditis treatment cannot be entirely applied to VGI. A French multidisciplinary group gathering infectious diseases specialists, anaesthesiologists, intensivists, microbiologists, radiologists and vascular surgeons was created to review the literature dealing with VGI and to make some proposals regarding empirical and documented antibiotic therapy for these infections. This article reveals these proposals.
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Affiliation(s)
- M Revest
- Infectious Diseases and Intensive Care Unit, Pontchaillou University Hospital, Rennes, France; CIC Inserm 1414, Rennes 1 University, Rennes, France
| | - F Camou
- Intensive Care Unit, Saint-André University Hospital, Bordeaux, France
| | - E Senneville
- Infectious Diseases Department, Gustave Dron Hospital, Tourcoing, Lille 2 University, France
| | - J Caillon
- Bacteriology Department, EA 3826 Nantes University, Hôtel Dieu University Hospital, Nantes, France
| | - F Laurent
- Bacteriology Department, International Center for Infectiology Research (CIRI) - INSERM U1111, CNRS UMR5308, Lyon 1 University, ENS de Lyon, Hospices Civils de Lyon, Lyon, France
| | - B Calvet
- Anesthesiology Department, Beziers, France
| | - P Feugier
- Department of Vascular Surgery, University Claude Bernard Lyon 1, Hospices Civils de Lyon, Lyon, France
| | - M Batt
- Department of Vascular Surgery, University of Nice-Sophia Antipolis, Nice, France
| | - C Chidiac
- Infectious Diseases Department, University Claude Bernard Lyon 1, Hospices Civils de Lyon, Inserm U1111, Lyon 1 University, Lyon, France.
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7
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Antistaphylococcal penicillins versus cephalosporins for definitive treatment of meticillin-susceptible Staphylococcus aureus bacteraemia: a systematic review and meta-analysis. Int J Antimicrob Agents 2014; 44:486-92. [PMID: 25311850 DOI: 10.1016/j.ijantimicag.2014.09.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 08/29/2014] [Accepted: 09/02/2014] [Indexed: 11/21/2022]
Abstract
The objective of this study was to assess the comparative effectiveness and safety of antistaphylococcal penicillins (ASPs) and cephalosporins for the definitive treatment of patients with meticillin-susceptible Staphylococcus aureus (MSSA) bacteraemia. PubMed and Scopus electronic databases were searched up to December 2013. All-cause mortality was the primary outcome of interest. A meta-analysis of unadjusted and adjusted data was performed. Seven articles (1643 patients) were included; all but one were retrospective studies, and three of them employed propensity score matching. The studies enrolled primarily adults hospitalised in medical wards for primary or secondary community-acquired, healthcare-associated or nosocomial MSSA bacteraemia. Several ASPs and cephalosporins were compared. Unadjusted 30-day mortality was lower in patients treated with ASPs than in those treated with cephalosporins [risk ratio (RR)=0.62, 95% confidence interval (CI) 0.40-0.98]. Propensity score-adjusted 30-day mortality was not different in patients receiving ASPs or cephalosporins (RR=0.75, 95% CI 0.41-1.39). Substantial heterogeneity and publication bias were found in these analyses. Both unadjusted (RR=0.85, 95% CI 0.54-1.32) and adjusted (RR=1.42, 95% CI 0.22-9.06) 90-day mortality did not differ between patients receiving ASPs or cephalosporins. Limited data regarding adverse events, development of resistance and recurrence were available. In conclusion, the limited available published data derive from retrospective studies and show that there appears to be no statistically significant difference in mortality between ASPs and cephalosporins for the treatment of MSSA bacteraemia.
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van Hasselt JGC, Allegaert K, van Calsteren K, Beijnen JH, Schellens JHM, Huitema ADR. Semiphysiological versus empirical modelling of the population pharmacokinetics of free and total cefazolin during pregnancy. BIOMED RESEARCH INTERNATIONAL 2014; 2014:897216. [PMID: 24672799 PMCID: PMC3930089 DOI: 10.1155/2014/897216] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 12/10/2013] [Accepted: 12/18/2013] [Indexed: 11/26/2022]
Abstract
This work describes a first population pharmacokinetic (PK) model for free and total cefazolin during pregnancy, which can be used for dose regimen optimization. Secondly, analysis of PK studies in pregnant patients is challenging due to study design limitations. We therefore developed a semiphysiological modeling approach, which leveraged gestation-induced changes in creatinine clearance (CrCL) into a population PK model. This model was then compared to the conventional empirical covariate model. First, a base two-compartmental PK model with a linear protein binding was developed. The empirical covariate model for gestational changes consisted of a linear relationship between CL and gestational age. The semiphysiological model was based on the base population PK model and a separately developed mixed-effect model for gestation-induced change in CrCL. Estimates for baseline clearance (CL) were 0.119 L/min (RSE 58%) and 0.142 L/min (RSE 44%) for the empirical and semiphysiological models, respectively. Both models described the available PK data comparably well. However, as the semiphysiological model was based on prior knowledge of gestation-induced changes in renal function, this model may have improved predictive performance. This work demonstrates how a hybrid semiphysiological population PK approach may be of relevance in order to derive more informative inferences.
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Affiliation(s)
- J. G. Coen van Hasselt
- Department of Clinical Pharmacology, Netherlands Cancer Institute, Plesmanlaan 121, P.O. Box 1066 CX, Amsterdam, The Netherlands
- Department of Pharmacy & Pharmacology, Netherlands Cancer Institute/Slotervaart Hospital, Louwesweg 6, P.O. Box 90440, 1006 BK Amsterdam, The Netherlands
| | - Karel Allegaert
- Department of Development and Regeneration, KU Leuven, Herestraat 49, 300 Leuven, Belgium
- Neonatal Intensive Care Unit, University Hospitals Leuven, Herestraat 49, 300 Leuven, Belgium
| | - Kristel van Calsteren
- Department of Development and Regeneration, KU Leuven, Herestraat 49, 300 Leuven, Belgium
- Obstetrics and Gynecology, University Hospitals Leuven, Herestraat 49, 300 Leuven, Belgium
| | - Jos H. Beijnen
- Department of Pharmacy & Pharmacology, Netherlands Cancer Institute/Slotervaart Hospital, Louwesweg 6, P.O. Box 90440, 1006 BK Amsterdam, The Netherlands
- Division of Pharmacoepidemiology & Clinical Pharmacology, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, P.O. Box 80125, 3508 TC Utrecht, The Netherlands
| | - Jan H. M. Schellens
- Department of Clinical Pharmacology, Netherlands Cancer Institute, Plesmanlaan 121, P.O. Box 1066 CX, Amsterdam, The Netherlands
- Division of Pharmacoepidemiology & Clinical Pharmacology, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, P.O. Box 80125, 3508 TC Utrecht, The Netherlands
| | - Alwin D. R. Huitema
- Department of Clinical Pharmacology, Netherlands Cancer Institute, Plesmanlaan 121, P.O. Box 1066 CX, Amsterdam, The Netherlands
- Department of Pharmacy & Pharmacology, Netherlands Cancer Institute/Slotervaart Hospital, Louwesweg 6, P.O. Box 90440, 1006 BK Amsterdam, The Netherlands
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Abrutyn E, Cabell CH, Fowler VG, Hoen B, Miro JM, Mestres CA, Sexton DJ, Corey GR. Medical treatment of endocarditis. Curr Infect Dis Rep 2010; 9:271-82. [PMID: 17618546 DOI: 10.1007/s11908-007-0043-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Infective endocarditis (IE) remains a serious and deadly disease. The incidence, which varies by gender and on the presence of predisposing factors, has not decreased, due in part to the aging population with more healthcare exposures and predisposing risk factors such as prosthetic heart valves and intracardiac devices. The most important aspects of treatment in IE hinge upon early diagnosis, microorganism identification with susceptibility testing, and early initiation of appropriate antibiotic therapy. In addition, echocardiographic imaging is critical for both diagnostic and prognostic purposes. Early evaluation for surgery should be considered. Once a therapeutic strategy is begun, careful attention to the clinical course is necessary to ensure appropriate response to therapy and to identify complications early.
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Affiliation(s)
- Elias Abrutyn
- Duke Clinical Research Institute, DUMC Box 2705, Durham, NC 27710, USA
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10
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Determination of an inoculum effect with various cephalosporins among clinical isolates of methicillin-susceptible Staphylococcus aureus. Antimicrob Agents Chemother 2010; 54:2206-8. [PMID: 20211890 DOI: 10.1128/aac.01325-09] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using 98 clinical methicillin-susceptible Staphylococcus aureus isolates of known beta-lactamase (Bla) type, we found a pronounced inoculum effect for cephalexin (mostly Bla type A and C strains), a mild inoculum effect for cephalothin (especially types B and C), and no inoculum effects for ceftriaxone and cefuroxime. Ceftobiprole showed the lowest MICs at a high inoculum but with a slight increase for Bla-positive versus Bla-negative strains. Since a potential therapeutic effect associated with a cephalosporin inoculum effect has been described, further studies are warranted.
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11
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Fernández Guerrero ML, González López JJ, Goyenechea A, Fraile J, de Górgolas M. Endocarditis caused by Staphylococcus aureus: A reappraisal of the epidemiologic, clinical, and pathologic manifestations with analysis of factors determining outcome. Medicine (Baltimore) 2009; 88:1-22. [PMID: 19352296 DOI: 10.1097/md.0b013e318194da65] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Staphylococcus aureus is the leading cause of infectious endocarditis and its mortality has remained high despite better diagnostic and therapeutic procedures over time. We conducted a retrospective review of 133 cases of definite S. aureus endocarditis seen at a single tertiary care hospital over 22 years to assess changes in the epidemiology and incidence of the infection, manifestations, outcome, risk factors for mortality, and impact of cardiac surgery on prognosis.Patients were classified into 2 groups: 1) right-sided endocarditis (64 patients) and 2) left-sided endocarditis (69 patients). While the number of cases of left-sided endocarditis remained steady at 1-3 cases per 10,000 admissions, the incidence of right-sided endocarditis, after a peak in the early 1990s, declined to almost disappear in 2001. Among the cases of right-sided endocarditis, we found 2 subsets of patients with different clinical features and prognosis: the first subset comprised 53 intravenous drug abusers, and the second subset comprised 11 patients with catheter-associated S. aureus bacteremia and endocarditis. Fifty-one patients were human immunodeficiency virus (HIV)-positive drug abusers, most of whom (80.3%) had right-sided endocarditis. We did not find differences in mortality between HIV-positive and HIV-negative individuals; mortality seemed to depend more on the site of the heart involved than on HIV status.Among the cases of left-sided endocarditis, the mitral valve was more commonly involved than the aortic valve (61% vs. 30%). Overall, 74% of patients with left-sided endocarditis developed 1 or more cardiac or extracardiac complication. In comparison, only 23.4% of patients with right-sided endocarditis developed complications.Prosthetic valve endocarditis (PVE) was hospital-acquired more frequently than native valve endocarditis (NVE). Patients with PVE had a shorter duration of symptoms until diagnosis and presented with or developed cardiac murmurs less frequently than patients with NVE. Cardiac failure (49%), renal failure (43%) and central nervous system (CNS) events (35%) were frequently observed in patients with both PVE and NVE. Valve replacement was more frequently needed and more rapidly performed in patients with PVE than in their counterparts with NVE.The overall mortality of patients with right-sided endocarditis was 17%. While the mortality of right-sided endocarditis in injection drug users was 3.7%, the mortality of patients with right-sided endocarditis associated with infected intravenous catheters was 82% (odds ratio [OR], 0.01; 95% confidence interval [CI], 0.001-0.07). For left-sided endocarditis mortality was 38% and was not significantly different in patients with NVE or PVE (OR, 0.65; 95% CI, 0.23-1.87). CNS complications were associated with mortality in both NVE (OR, 6.55; 95% CI, 1.78-24.04) and PVE (OR, 32; 95% CI, 2.63-465.40). Development of 2 or 3 complications was associated with an increased risk of mortality (OR, 5.59; 95% CI, 1.08-28.80 and OR, 9.25; 95% CI, 1.36-62.72 for 2 vs. 1 complication and for 3 vs. 2 complications, respectively).Surgical treatment did not significantly influence mortality in cases of NVE, (OR, 3.19; 95% CI, 0.76-13.38) but significantly improved the prognosis of patients with PVE (OR, 69; 95% CI, 2.89-1647.18).S. aureus endocarditis is an aggressive, often fatal, infection. The results of the current study suggest that valve replacement will improve the outcome of infection, particularly in patients with PVE.
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Affiliation(s)
- Manuel L Fernández Guerrero
- From the Division of Infectious Diseases (Department of Medicine) and Department of Cardiac Surgery. Fundación Jiménez Díaz. Universidad Autónoma de Madrid, Spain
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12
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Vella-Brincat JWA, Begg EJ, Kirkpatrick CMJ, Zhang M, Chambers ST, Gallagher K. Protein binding of cefazolin is saturable in vivo both between and within patients. Br J Clin Pharmacol 2007; 63:753-7. [PMID: 17223858 PMCID: PMC2000586 DOI: 10.1111/j.1365-2125.2006.02827.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
AIMS The aims of the study were a) to determine if there is evidence of saturable protein binding of cefazolin in plasma across the range of concentrations achieved clinically (between patient variability) and b) to investigate whether saturable protein binding is also evident from trough and peak concentrations in the same patient (within patient variability). METHODS Unbound and total plasma concentrations were measured in patients who were treated with cefazolin intravenously by continuous infusion or intermittent injection. In study (i) single random samples were taken from one series of patients. In study (ii) paired samples (troughs and peaks) were taken from a second series of patients. RESULTS Thirty-one patients were included in study (i). Linear regression analysis of the percentage unbound vs. unbound plasma concentrations revealed a slope significantly different from zero, suggesting saturable protein binding. Mean values for percentage unbound ranged from 9% at low concentrations (8.5 mg l(-1)) to 51% at high concentrations (140 mg l(-1)). Twelve patients were investigated in study (ii). Values for protein binding ranged from 85% at low concentrations (2.7 mg l(-1)) to 52% at high concentrations (200.3 mg l(-1)). The percentage unbound was significantly higher (P < 0.0001) at high (peak) concentrations than at lower (trough) concentrations, confirming saturable protein binding. CONCLUSIONS The protein binding of cefazolin is saturable in vivo in humans, both between and within patients.
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Baddour LM, Wilson WR, Bayer AS, Fowler VG, Bolger AF, Levison ME, Ferrieri P, Gerber MA, Tani LY, Gewitz MH, Tong DC, Steckelberg JM, Baltimore RS, Shulman ST, Burns JC, Falace DA, Newburger JW, Pallasch TJ, Takahashi M, Taubert KA. Infective endocarditis: diagnosis, antimicrobial therapy, and management of complications: a statement for healthcare professionals from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, and the Councils on Clinical Cardiology, Stroke, and Cardiovascular Surgery and Anesthesia, American Heart Association: endorsed by the Infectious Diseases Society of America. Circulation 2006; 111:e394-434. [PMID: 15956145 DOI: 10.1161/circulationaha.105.165564] [Citation(s) in RCA: 912] [Impact Index Per Article: 50.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Despite advances in medical, surgical, and critical care interventions, infective endocarditis remains a disease that is associated with considerable morbidity and mortality. The continuing evolution of antimicrobial resistance among common pathogens that cause infective endocarditis creates additional therapeutic issues for physicians to manage in this potentially life-threatening illness. METHODS AND RESULTS This work represents the third iteration of an infective endocarditis "treatment" document developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It updates recommendations for diagnosis, treatment, and management of complications of infective endocarditis. A multidisciplinary committee of experts drafted this document to assist physicians in the evolving care of patients with infective endocarditis in the new millennium. This extensive document is accompanied by an executive summary that covers the key points of the diagnosis, antimicrobial therapy, and management of infective endocarditis. For the first time, an evidence-based scoring system that is used by the American College of Cardiology and the American Heart Association was applied to treatment recommendations. Tables also have been included that provide input on the use of echocardiography during diagnosis and treatment of infective endocarditis, evaluation and treatment of culture-negative endocarditis, and short-term and long-term management of patients during and after completion of antimicrobial treatment. To assist physicians who care for children, pediatric dosing was added to each treatment regimen. CONCLUSIONS The recommendations outlined in this update should assist physicians in all aspects of patient care in the diagnosis, medical and surgical treatment, and follow-up of infective endocarditis, as well as management of associated complications. Clinical variability and complexity in infective endocarditis, however, dictate that these guidelines be used to support and not supplant physician-directed decisions in individual patient management.
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Fernández-Guerrero ML, de Górgolas M. Cefazolin Therapy for Staphylococcus aureus Bacteremia. Clin Infect Dis 2005; 41:127. [PMID: 15937778 DOI: 10.1086/430833] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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15
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Xiong YQ, Willard J, Kadurugamuwa JL, Yu J, Francis KP, Bayer AS. Real-time in vivo bioluminescent imaging for evaluating the efficacy of antibiotics in a rat Staphylococcus aureus endocarditis model. Antimicrob Agents Chemother 2005; 49:380-7. [PMID: 15616318 PMCID: PMC538900 DOI: 10.1128/aac.49.1.380-387.2005] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Therapeutic options for invasive Staphylococcus aureus infections have become limited due to rising antimicrobial resistance, making relevant animal model testing of new candidate agents more crucial than ever. In the present studies, a rat model of aortic infective endocarditis (IE) caused by a bioluminescently engineered, biofilm-positive S. aureus strain was used to evaluate real-time antibiotic efficacy directly. This strain was vancomycin and cefazolin susceptible but gentamicin resistant. Bioluminescence was detected and quantified daily in antibiotic-treated and control animals with IE, using a highly sensitive in vivo imaging system (IVIS). Persistent and increasing cardiac bioluminescent signals (BLS) were observed in untreated animals. Three days of vancomycin therapy caused significant reductions in both cardiac BLS (>10-fold versus control) and S. aureus densities in cardiac vegetations (P < 0.005 versus control). However, 3 days after discontinuation of vancomycin therapy, a greater than threefold increase in cardiac BLS was observed, indicating relapsing IE (which was confirmed by quantitative culture). Cefazolin resulted in modest decreases in cardiac BLS and bacterial densities. These microbiologic and cardiac BLS differences during therapy correlated with a longer time-above-MIC for vancomycin (>12 h) than for cefazolin ( approximately 4 h). Gentamicin caused neither a reduction in cardiac S. aureus densities nor a reduction in BLS. There were significant correlations between cardiac BLS and S. aureus densities in vegetations in all treatment groups. These data suggest that bioluminescent imaging provides a substantial advance in the real-time monitoring of the efficacy of therapy of invasive S. aureus infections in live animals.
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Affiliation(s)
- Yan Q Xiong
- Division of Infectious Diseases, St. John's Cardiovascular Research Center, Harbor-UCLA Research and Education Institute, 1124 W. Carson St., Torrance, CA 90502, USA.
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Stryjewski ME, Chu VH, Cabell CH, Fowler VG. Issues in the Management of Endocarditis Caused by Resistant Gram-positive Organisms. Curr Infect Dis Rep 2004; 6:283-291. [PMID: 15265456 DOI: 10.1007/s11908-004-0049-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Most cases of infective endocarditis (IE) are caused by gram-positive bacteria such as enterococci, streptococci, and staphylococci. Increasing resistance among these organisms has eroded the utility of mainstay antibiotics and complicated the management of this difficult-to-treat infection. Clinical experience with newer gram-positive antibiotics to treat IE is limited.
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Affiliation(s)
- Martin E. Stryjewski
- Box 3281, Room 34228 Red Zone Duke South, Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
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Gavaldà J, López P, Martín T, Gomis X, Ramírez JL, Azuaje C, Almirante B, Pahissa A. Efficacy of ceftriaxone and gentamicin given once a day by using human-like pharmacokinetics in treatment of experimental staphylococcal endocarditis. Antimicrob Agents Chemother 2002; 46:378-84. [PMID: 11796345 PMCID: PMC127055 DOI: 10.1128/aac.46.2.378-384.2002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We compared the efficacy of ceftriaxone combined with gentamicin, both given once a day, with that of cloxacillin given every 4 h plus gentamicin given once a day or in three daily doses (t.i.d.) for the treatment of experimental methicillin-susceptible staphylococcal endocarditis. The antibiotics were administered by using human-like (H-L) pharmacokinetics that simulated the profiles of these drugs in human serum. Animals with catheter-induced endocarditis were infected intravenously with 10(5) CFU of Staphylococcus aureus S5 (MICs and minimal bactericidal concentrations of cloxacillin, ceftriaxone, and gentamicin, 0.5 and 2 microg/ml, 4 and 8 microg/ml, and 0.5 and 1 microg/ml, respectively). The animals were then treated for 24 h with cloxacillin at a dose of 2 g that simulated H-L pharmacokinetics (H-L 2 g) every 4 h alone or combined with gentamicin (administered at doses of H-L 1 mg/kg of body weight every 8 h or H-L 4.5 mg/kg every 24 h) or with ceftriaxone at H-L 2 g every 24 h alone or combined with gentamicin (administered at doses of H-L 1 mg/kg every 8 h or H-L 4.5 mg/kg every 24 h). The results of therapy for experimental endocarditis due to the S5 strain showed that (i) cloxacillin alone is more effective than ceftriaxone alone in reducing the bacterial load (P < 0.01), (ii) the combination of cloxacillin or ceftriaxone with gentamicin is more effective than each of these drugs alone (P < 0.01), and (iii) Ceftriaxone H-L plus gentamicin H-L 4.5 mg/kg, both administered every 24 h, showed efficacy similar to that of the "gold standard," cloxacillin H-L plus gentamicin H-L 1 mg/kg t.i.d. (P > 0.05). An increase in the interval of administration of gentamicin to once daily resulted in a reduction in the numbers of bacteria in the vegetations equivalent to that achieved with the recommended regimen of cloxacillin plus gentamicin t.i.d. in the treatment of experimental endocarditis due to methicillin-susceptible S. aureus. Ceftriaxone plus gentamicin, both administered once a day, may be useful for home-based therapy for selected cases of staphylococcal endocarditis.
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Affiliation(s)
- Joan Gavaldà
- Infectious Diseases Research Laboratory, Infectious Diseases Division, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain.
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Talan DA, Summanen PH, Finegold SM. Ampicillin/sulbactam and cefoxitin in the treatment of cutaneous and other soft-tissue abscesses in patients with or without histories of injection drug abuse. Clin Infect Dis 2000; 31:464-71. [PMID: 10987706 DOI: 10.1086/313971] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/1999] [Revised: 01/07/2000] [Indexed: 11/04/2022] Open
Abstract
A randomized, double-blind trial compared the clinical and bacteriologic efficacy of ampicillin/sulbactam (2 g/1 g) and cefoxitin (2 g) administered intravenously every 6 h to patients with (n=49) or without (n=47) histories of injection drug abuse who presented with cutaneous or other soft-tissue infections. Cure or improvement occurred in 89.8% of ampicillin/sulbactam-treated patients, compared with 93.6% of cefoxitin-treated patients. The median time to resolution of all symptoms was 10.5 days with ampicillin/sulbactam treatment and 15.5 days with cefoxitin treatment. Mixed aerobic-anaerobic infection was encountered frequently in both treatment groups. A significantly higher percentage of Streptococcus species was found in the major abscesses of the patients with histories of injection drug abuse, compared with those without such histories (37% vs. 19%, respectively; P=.0009). Overall, ampicillin/sulbactam eradicated pathogens from the major abscesses in 100% of patients, whereas the eradication rate with cefoxitin was 97.9%. The 2 drugs were well tolerated. Ampicillin/sulbactam and cefoxitin were equally effective for the empirical treatment of cutaneous or other soft-tissue infections in injection drug abusers and patients who did not inject drugs.
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Affiliation(s)
- D A Talan
- Department of Medicine, Division of Emergency Medicine and Infectious Diseases, Olive View-University of California Los Angeles Medical Center, Sylmar, CA 91342, USA.
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Marshall SA, Wilke WW, Chen YS, Pfaller MA, Jones RN. In vitro activity of cefepime and other broad-spectrum beta-lactams tested against 129 mec A-negative Staphylococcus spp. isolates: a multicenter sample. Diagn Microbiol Infect Dis 1998; 30:65-9. [PMID: 9488834 DOI: 10.1016/s0732-8893(97)00175-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The in vitro activity of cefepime was compared to that of penicillin, piperacillin/tazobactam, ceftazidime, ceftriaxone, imipenem, vancomycin, and teicoplanin by using the broth microdilution method against 129 isolates of Staphylococcus [50 S. aureus and 79 coagulase-negative staphylococci (CoNS], selected for their lack of the mec A gene as determined by the polymerase chain reaction. These isolates were obtained from a recent (1995-1996) surveillance of nearly 5000 nosocomial blood stream isolates from more than 40 geographically diverse U.S. medical centers. These results were compared to CoNS results from the same collection selected for their phenotypic susceptibility to oxacillin (OS; MIC < or = 2 micrograms/ml) regardless of their med A genotype. Cefepime, as well as piperacillin/ tazobactam, ceftriaxone, and imipenem, showed 100% susceptibility against OS and mec A-negative staphylococci. Ceftazidime showed relative resistance (30.2% resistant) against CoNS classified as OS based on phenotypic characteristics (MIC < or = 2 micrograms/mL) as compared to strains of mec A-negative CoNS (5.1% resistant). Accurate phenotypic detection of mec A-positive staphylococci by simple standardized in vitro susceptibility tests becomes very important to guide empirical use of beta-lactams for therapy. Furthermore, previously published MIC90 and range data for broad-spectrum beta-lactams versus OS have been falsely elevated by the presence of mec A-positive strains. The greater use of these potent beta-lactams against true mec A-negative staphylococci should enhance clinical outcomes and reduce the need for vancomycin.
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Affiliation(s)
- S A Marshall
- Department of Pathology, University of Iowa College of Medicine, Iowa City 52242, USA
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20
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Frank U, Chambers HF. Treatment of Staphylococcus aureus catheter-related infection and infective endocarditis with granulocyte colony-stimulating factor in the experimental rabbit model. Antimicrob Agents Chemother 1996; 40:1308-10. [PMID: 8723492 PMCID: PMC163317 DOI: 10.1128/aac.40.5.1308] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The role of granulocyte colony-stimulating factor with and without antibiotics in the treatment of catheter-related infection and infective endocarditis caused by methicillin-susceptible Staphylococcus aureus was assessed in the experimental rabbit model. Granulocyte colony-stimulating factor stimulated leukocytosis in infected animals but did not increase the clearance of methicillin-susceptible S. aureus from peripheral blood, subcutaneous port catheters, intravascular cardiac catheters, or aortic valve vegetations.
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Affiliation(s)
- U Frank
- San Francisco General Hospital, University of California-San Francisco, USA
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Brandt CM, Rouse MS, Tallan BM, Laue NW, Wilson WR, Steckelberg JM. Effective treatment of cephalosporin-rifampin combinations against cryptic methicillin-resistant beta-lactamase-producing coagulase-negative staphylococcal experimental endocarditis. Antimicrob Agents Chemother 1995; 39:1815-9. [PMID: 7486924 PMCID: PMC162831 DOI: 10.1128/aac.39.8.1815] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The efficacy of cefazolin or cefpirome alone or combined with rifampin was compared with that of vancomycin alone or combined with rifampin in an experimental model of methicillin-resistant, beta-lactamase-producing, coagulase-negative staphylococcal endocarditis. Phenotypically, the mecA gene-positive strain used in vivo did not exhibit methicillin resistance by the agar dilution or disk susceptibility method but was resistant in vitro (oxacillin MIC, 64 micrograms/ml) by the microtiter dilution method with 2% NaCl supplementation. Macrodilution broth susceptibilities of standard inocula failed to demonstrate cross-resistance of staphylococci to cefazolin (MIC, 8 micrograms/ml) or cefpirome (MIC, 4 micrograms/ml). In vivo, vancomycin and cefpirome had similar activities, and both regimens were more effective than was cefazolin alone. While the MIC of rifampin was low (0.031 micrograms/ml), monotherapy with rifampin resulted in a bimodal distribution of outcomes due to the expected emergence of resistant mutants. The results in vitro of time-kill synergy studies using rifampin in combination with cefazolin or cefpirome varied with the antimicrobial concentrations tested and did not reliably predict activities in vivo of rifampin-beta-lactam combination therapies. Cefpirome, but not cefazolin or vancomycin, in combination with rifampin was synergistic in vivo. Cefpirome in combination with rifampin was more effective than was cefazolin in combination with rifampin. Both cephalosporin-rifampin regimens were significantly more effective than was cephalosporin or vancomycin monotherapy and were as effective as vancomycin combined with rifampin. These data support further evaluation of rifampin-beta-lactam combinations as possible alternative therapies to vancomycin-containing regimens for selected methicillin-resistant coagulase-negative staphylococcal infections.
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Affiliation(s)
- C M Brandt
- Infectious Diseases Research Laboratory, Mayo Clinic, Rochester, Minnesota 55905, USA
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Brandt CM, Rouse MS, Tallan BM, Wilson WR, Steckelberg JM. Failure of time-kill synergy studies using subinhibitory antimicrobial concentrations to predict in vivo antagonism of cephalosporin-rifampin combinations against Staphylococcus aureus. Antimicrob Agents Chemother 1994; 38:2191-3. [PMID: 7811044 PMCID: PMC284709 DOI: 10.1128/aac.38.9.2191] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Results of in vitro time-kill synergy studies using subinhibitory, inhibitory, or suprainhibitory concentrations of bactericidal agents were compared with treatment outcomes of experimental infective endocarditis due to a methicillin-susceptible strain of Staphylococcus aureus. For rifampin-cephalosporin combinations, in vitro synergy testing using recommended fractions of the MIC failed to predict antagonism in vivo while concentrations above the MIC corresponded with antagonism in vivo.
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Affiliation(s)
- C M Brandt
- Infectious Diseases Research Laboratory, Mayo Clinic, Rochester, Minnesota 55905
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