Clinical and Microbiological Effect of Linezolid on Methicillin-Resistant Staphylococcus aureus (MRSA) Colonization in Healthcare Workers in Egypt (original) (raw)
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Core Evidence, 2012
Methicillin-resistant Staphylococcus aureus (MRSA), including community-associated and hospital-associated strains, is a major cause of human morbidity and mortality. Treatment options have become limited due to the emergence of MRSA strains with decreased sensitivity to vancomycin, which has long been the first-line therapy for serious infections. This has prompted the search for novel antibiotics that are efficacious against MRSA. Linezolid, an oxazolidinone class of antibiotic, was approved by the Food and Drug Administration in 2000 for treatment of MRSA infections. Since then, there have been a multitude of clinical trials and research studies evaluating the effectiveness of linezolid against serious infections, including pneumonia (both community-and hospital-acquired), skin and soft-tissue infections such as diabetic foot ulcers, endocarditis, osteomyelitis, prosthetic devices, and others. The primary aim of this review is to provide an up-to-date evaluation of the clinical evidence for using linezolid to treat MRSA infections, with a focus on recently published studies, including those on nosocomial pneumonia. Other objectives are to analyze the cost-effectiveness of linezolid compared to other agents, and to review the pharmokinetics and pharmacodynamics of linezolid, emphasizing the most current concepts.
International Journal of Infectious Diseases, 2010
Background: Staphylococcus aureus is a facultatively anaerobic, Gram-positive coccus. It is a major pathogen associated with serious community and hospitalacquired infections. By designation methicillin resistant Staphylococcus aureus (MRSA) is a strain of Staphylococcus aureus that is resistant to all beta-lactams, including penicillins, cephalosporins and carbapenems. Vancomycin has a narrow spectrum of activity, restricted to most Gram-positive bacteria, and is the drug of choice for the treatment of methicillin resistant Staphylococcus aureus. This agent, however, requires intravenous administration, and occasionally patients experience unacceptable side effects. Linezolid, a member of the new oxazolidinone class of antibiotics, has shown very good activity against methicillin resistant Staphylococcus aureus, has excellent oral bioavailability and is inexpensive as compared to vancomycin. Aims and Objectives: Comparison of in vitro activities of vancomycin and linezolid against methicillin resistant Staphylococcus aureus. Materials and Method: The study was conducted over a period of 6 months. Fifty Methicillin resistant Staphylococcus aureus isolated from the clinical isolates of Military hospital Rawalpindi were subjected to the determination of Minimum inhibitory concentrations of linezolid and vancomycin using E-strips. Minimum inhibitory concentrations 50 and minimum inhibitory concentrations 90 were calculated. Results: All the isolated organisms were uniformly susceptible to both the antibiotics. Vancomycin showed higher minimum inhibitory concentrations (MICs) as compared to linezolid MICs. Conclusion: This study suggests that linezolid and vancomycin have similar in vitro efficacy for methicillin resistant Staphylococcus aureus infections. Linezolid's oral dosing option can allow earlier discharge of hospitalized patients and its low cost reduces health care expenses.
Journal of Microbiology and Infectious Diseases
Objective: Methicillin resistant Staphylococcus aureus is a major nosocomial pathogen causing significant morbidity and mortality. The aim of this study was to evaluate the in vitro activity of linezolid against methicillin-resistant S. aureus. Methods: This was a descriptive study carried out at the Department of Microbiology, Army Medical College Rawalpindi from January to July 2010. The in vitro minimum inhibitory concentration of linezolid was determined against 74 strains of methicillin-resistant S. aureus by using the Epsilon-test (E-test) method (AB Biodisk, Sweden). Methicillin-resistant S. aureus was isolated from routine clinical specimens using standard microbiological procedures. Cefoxitin (30 μg) disk was used for detection of methicillin-resistant strains of Staphylococcus aureus. Results: Seventy-four isolates of methicillin-resistant S. aureus were obtained from various clinical samples. The majority of samples were from the pus followed by nasobronchial lavage, urine and vaginal swabs. All the isolates were highly susceptible to linezolid with minimum inhibitory concentration range of 0.023-0.75 mg/dL having MIC50 0.25 and MIC90 0.5 mg/dL respectively. Conclusion: Linezolid shows good in vitro activity against methicillin-resistant Staphylococcus aureus.
Objectives: To evaluate the in-vitro activities of linezolid, vancomycin, ciprofloxacin, gentamicin, amikacin, trimethoprim and fusidic acid, against methicillin resistant isolates. Materials and Methods: Three hundred and twenty two non-duplicate archived Staphylococcal isolates recovered from routine cultures performed in the microbiology laboratory from wounds, and abscesses swabs, urine, blood, pus, derived from both in-and out patients were tested. Results: A total of 274 S. aureus and 76 CNS clinical isolates were included in the study, 46.7% were MRSA and 21% methicillin resistant CNS (MRCNS). None of the strains was found to be resistant to linezolid and vancomycin. The resistance rates of MRSA isolates to antibiotics were as follows: 86% to gentamicin, 84.3% to fusidic acid, 80% to trimethoprim, 78.2% to ciprofloxacin and 76.5% to amikacin. Similar trend were also obtained for MRCNS isolates. The majority (70%) of MRSA isolates were resistant to all used classes of antibiotics in the study, while only 4.3% were sensitive to such antimicrobial agents. Conclusion: Due to the high prevalence of multi-drug resistant MRSA, this study has provided valuable baseline information to clinicians regarding the benefit of linezolid, suggesting that it can be used as an alternative drug in such severe life threatening infections caused by MRSA, especially if the side effect of vancomycin was observed.
Correlation between oxacillin MIC values with those of linezolid against clinical isolates of MRSA
Indian Journal of Microbiology Research, 2023
Background: Infection by methicillin-resistant Staphylococcus aureus (MRSA) is a great threat to medical care facilities and also in communities, due to its multidrug resistance to commonly used antimicrobial agents. The overuse of glycopeptide antibiotics, such as vancomycin and linezolid, has led to the emergence of reduced susceptibility to these anti-MRSA agents, which in turn may lead to therapeutic failure. This study has been conducted to explore the correlation if any, of MIC of oxacillin to the MIC of linezolid in clinically significant isolates of MRSA in a tertiary care hospital. Materials and Methods: The study was carried out over the period of two months after obtaining a waiver of consent from the Institute Ethics Committee. Seventy-five clinically significant MRSA isolates were included in the study. All MRSA isolates were subjected to cefoxitin and linezolid antibiotic disk susceptibility testing. Minimum inhibitory concentration (MIC) to oxacillin and linezolid was performed by the agar dilution method. The MIC and MIC were also recorded both for oxacillin and linezolid MIC among these MRSA isolates. Correlation between oxacillin MIC and linezolid MIC was estimated using the Pearson correlation coefficient, r. Themajority of MRSA isolates (41%) were isolated from skin and soft tissue infections (SSTIs) (40%). MIC values for oxacillin ranged from 4 ?g/mL to >32?g/mL and MIC values for linezolid ranged from ? 0.25µg/mL to 4 µg/mL. The majority of these isolates (40%) had linezolid MIC of ? 0.25µg/mL. All the isolates were uniformly susceptible to linezolid. Pearson correlation coefficient, r was 0.41, between oxacillin MICs and linezolid MICs, which indicated poor correlation. Conclusion: Although we did not observe any resistance to linezolid among the MRSA isolates, we should monitor carefully the antibiotic selection pressure and creeping MIC, to aid in the early detection of the emergence of resistance. Keywords: MRSA, MIC creep, Linezolid, Oxacillin, Antimicrobial susceptibility testing.
Linezolid resistance in clinical isolates of Staphylococcus aureus
Journal of Antimicrobial Chemotherapy, 2003
Sir, Linezolid is the first oxazolidinone antibiotic to be licensed for treatment of Gram-positive infections. It is active against methicillin-resistant Staphylococcus aureus (MRSA), glycopeptide-intermediate S. aureus (GISA) and vancomycinresistant enterococci (VRE). 1 It inhibits the formation of the initiation complex formed with mRNA, fMet-tRNA and the 30S ribosomal subunit. Mutations to the central loop of domain V of 23S rRNA have been associated with resistance to linezolid in several species in vitro. 2 There has been one report of resistance of MRSA in a clinical infection, a patient with dialysis-related peritonitis. We report a second clinical infection due to a resistant MRSA, but unlike the earlier case this was shown to have developed from a susceptible isolate during treatment.
Clinical Microbiology and Infection, 2014
Complicated skin and soft tissue infections (cSSTIs) are a diverse group of infections, with a range of presentations and microbiological causes. Hospitalization is common for patients with a cSSTI, which is treated by drainage of the affected area and with antibiotics. Host factors such as co-morbidities, and microbial factors, in particular drug resistance, complicate the management of these infections. Methicillin-resistant Staphylococcus aureus (MRSA) is an important cSSTI pathogen in Europe, and its involvement can be associated with poor patient outcomes. European guidelines recommend vancomycin, teicoplanin, linezolid, daptomycin, tigecycline or ceftaroline for treatment of MRSA cSSTIs. Of primary importance when treating cSSTIs is the agent's clinical efficacy against the causative pathogens, as well as its bioavailability in the skin and associated structures. Linezolid is well-suited for the treatment of MRSA cSSTIs; it achieves high penetration into skin and soft tissues with 100% oral bioavailability, and therefore enables an intravenous to oral switch and outpatient treatment. When eligible patients are offered oral therapy the associated length of hospital stay and overall costs can be reduced. Linezolid has demonstrated clinical efficacy and favourable outcomes in patients for the treatment of MRSA cSSTIs including the treatment of lower extremity infections. Furthermore, efficacy has been documented in key defined populations, such as individuals with renal impairment and the obese. The safety profile of linezolid is well-documented, making this antibacterial a viable choice for the treatment of MRSA cSSTIs.
International Journal of Antimicrobial Agents, 2001
Background: Staphylococcus is responsible for a variety of medical problems, including skin and softtissue infections (SSTIs), surgical site infections (SSIs), endocarditis and hospital acquired bacteraemia. Methicillin resistance in staphylococcus has become a global problem limiting the treatment modalities to a large extent. Methods: The aim of this study was to evaluate the in vitro activity of linezolid and other antibiotics against clinical isolates of methicillin resistant staphylococcus (n=163); including 105 methicillin resistant Staphylococcus aureus and 58 methicillin resistant coagulase negative staphylococci. Antibiogram of these isolates was determined by the Kirby-Bauer disc diffusion method and minimum inhibitory concentration of linezolid was determined by standard agar dilution method. Results: Overall methicillin resistant S. aureus showed high multi-drug resistance. ATCC 25923 Staphylococcus aureus and ATCC 29213 Staphylococcus aureus were used as the standard control strains. MIC 90 of linezolid was comparable for methicillin resistant coagulase negative staphylococci and methicillin resistant S. Aureus (4.0 mg/L); however at MIC 50 linezolid was two fold more active against methicillin resistant coagulase negative staphylococci (1mg/L) than methicillin resistant S. aureus (2mg/L). Conclusion: It is concluded that linezolid has excellent activity against methicillin resistant staphylococci including multidrug resistant strains.
International Journal of Infectious Diseases, 2010
Background: Staphylococcus aureus is a facultatively anaerobic, Gram-positive coccus. It is a major pathogen associated with serious community and hospitalacquired infections. By designation methicillin resistant Staphylococcus aureus (MRSA) is a strain of Staphylococcus aureus that is resistant to all beta-lactams, including penicillins, cephalosporins and carbapenems. Vancomycin has a narrow spectrum of activity, restricted to most Gram-positive bacteria, and is the drug of choice for the treatment of methicillin resistant Staphylococcus aureus. This agent, however, requires intravenous administration, and occasionally patients experience unacceptable side effects. Linezolid, a member of the new oxazolidinone class of antibiotics, has shown very good activity against methicillin resistant Staphylococcus aureus, has excellent oral bioavailability and is inexpensive as compared to vancomycin. Aims and Objectives: Comparison of in vitro activities of vancomycin and linezolid against methicillin resistant Staphylococcus aureus. Materials and Method: The study was conducted over a period of 6 months. Fifty Methicillin resistant Staphylococcus aureus isolated from the clinical isolates of Military hospital Rawalpindi were subjected to the determination of Minimum inhibitory concentrations of linezolid and vancomycin using E-strips. Minimum inhibitory concentrations 50 and minimum inhibitory concentrations 90 were calculated. Results: All the isolated organisms were uniformly susceptible to both the antibiotics. Vancomycin showed higher minimum inhibitory concentrations (MICs) as compared to linezolid MICs. Conclusion: This study suggests that linezolid and vancomycin have similar in vitro efficacy for methicillin resistant Staphylococcus aureus infections. Linezolid's oral dosing option can allow earlier discharge of hospitalized patients and its low cost reduces health care expenses.
JPMA. The Journal of the Pakistan Medical Association, 2011
To compare the in vitro activities of vancomycin and linezolid against methicillin resistant Staphyloccus aureus in our set up to help in formulating a better empirical treatment and reduce the emergence of vancomycin resistant Staphylococcus aureus. The study was conducted over a period of 6 months (1st July 2009-31st Dec 2009). Fifty Methicillin resistant Staphylococcus aureus isolated from the clinical isolates of Military Hospital Rawalpindi were subjected to the determination of Minimum inhibitory concentrations of linezolid and vancomycin using E-strips. All the isolated organisms were uniformly susceptible to both the antibiotics. Vancomycin showed higher minimum inhibitory concentrations (MICs) as compared to linezolid MICs. This study suggests that linezolid and vancomycin have similar in vitro efficacy for methicillin resistant Staphyloccus aureus infections.