The Evaluation of Vancomycin and Daptomycin Susceptibility by E-Test Method in Methicillin-Resistant Staphylococcus aureus Isolates

• Main Authors: Firdevs AKSOY, İlknur YAVUZ, Gürdal YILMAZ, Selçuk KAYA, İftihar KÖKSAL
• Format: Article
• Language: English
• Published: Bilimsel Tip Yayinevi 2012-03-01
• Series: Flora Infeksiyon Hastalıkları ve Klinik Mikrobiyoloji Dergisi
• Subjects: Methicillin-resistant Staphylococcus aureus; Vancomycin; Daptomycin
• Online Access: http://www.floradergisi.org/getFileContent.aspx?op=REDPDF&file_name=2012-17-01-018-022.pdf
• ISSN: 1300-932X; 1300-932X

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial pathogen that can lead to epidemics and because of its multiple antibiotic resistance, it continues to pose a serious health problem all over the world. In many cases, MRSA becomes resistant to antibiotics in use today, which results in the need for the development of new anti-staphylococcal antibiotics. The first representative of cyclic lipopeptids, daptomycin, in this context, is a new antibiotic among effective anti-staphylococcal drugs. In this study, vancomycin and daptomycin susceptibilities of MRSA strains were investigated with the E-test method. Materials and Methods: In the study, the vancomycin and daptomycin susceptibilities of 51 MRSA strains isolated as cause of infection from various clinical specimens in our hospital were investigated in vitro between the years 2000 and 2006. Susceptibility tests were performed with E-test method by using vancomycin and daptomycin strips in Mueller-Hinton agar (MHA) medium. Results: All strains of MRSA were sensitive to vancomycin and daptomycin with E-test method. Vancomycin minimal inhibitory concentration (MIC) range was 0.5-1 µg/mL and daptomycin MIC range was 0.094-0.75 µg/mL. Daptomycin MIC50 was 0.25 µg/mL and MIC90 was 0.38 µg/mL; whereas, vancomycin MIC50 was 0.75 µg/mL and MIC90 was 1 µg mL. Conclusion: MIC values determined for vancomycin were at the highest level among the results. That may be taken as a sign of alarm for the resistance and clinical treatment failure of vancomycin. With the low MIC values, daptomycin seems to be a better option in the treatment of MRSA infections.