PREVALENCE OF METHICILLIN RESITANCE S. AUREUS AND EFFICACY OF ANTIBIOTIC COMBINATION BETWEEN VANCOMYCIN AND CEFEPIME OR GENTAMICIN AGAINST MRSA ISOLATED FROM BAC LIEU GENERAL HOSPITAL
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Abstract
Background: Methicillin resistant S. aureus (MRSA) is listed by Centers for Disease Control and Prevention as one of the: “Antibiotic Resistance Threats in the United States” because of its severity and multidrug resistance. Antibiotic combination treatment for MRSA infections has been shown promising treatment. Objective: To determine percentages detection of MRSA and efficacy of antibiotic combination between vancomycin and cefepime or gentamicin against MRSA strains. Methods: From 125 strains of S. aureus that were identified and performed routine antibiotic susceptibility testing by automated machine (Vitek2 Compact), 111 MRSA strains were determined by MIC (minimum inhibitory concentration) cefoxitin screen available in card AST-P592. In vitro antibiotic combination between vancomycin and cefepime on 111 MRSA strains; vancomycin and gentamicin on 53 MRSA strains by microdilution (checkerboard) method. Results: Prevalence of MRSA is 88.8%. MRSA was most widely distributed in pus (61.3%), fluid (22.5%), sputum (10.8%) and blood (5.4%). Based on the FIC (Fractional Inhibitory Concentration) index, vancomycin-cefepime combination showed synergism (45%), additive (51.3%), independent (3.6%) and no antagonism. Vancomycin-gentamicin combination showed synergism (39.6%), additive (58.5%), independent (1.9%) and no antagonism. Conclusion: High rate of MRSA was recorded at Bac Lieu General Hospital. Antibiotic combination between vancomycin and cefepime or gentamicin for high synergistic and additive effect against MRSA strains. The research results are the basis for doctors to consider the choice of antibiotic combination and the premise to study the effectiveness of antibiotic combination in clinical practice.
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Keywords
S. aureus, MRSA, combination antibiotics, vancomycin, checkerboard
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