In Vitro Activity of Ceftaroline Alone and in Dual Combinations Against Methicillin-Resistant Staphylococcus aureus Isolates

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KARA ALTAY G., ÖKSÜZ L.

FLORA INFEKSIYON HASTALIKLARI VE KLINIK MIKROBIYOLOJI DERGISI, cilt.30, sa.4, ss.1-14, 2025 (ESCI, TRDizin)

• Yayın Türü: Makale / Tam Makale
• Cilt numarası: 30 Sayı: 4
• Basım Tarihi: 2025
• Doi Numarası: 10.5578/flora.2025041464
• Dergi Adı: FLORA INFEKSIYON HASTALIKLARI VE KLINIK MIKROBIYOLOJI DERGISI
• Derginin Tarandığı İndeksler: Emerging Sources Citation Index (ESCI), TR DİZİN (ULAKBİM)
• Sayfa Sayıları: ss.1-14
• Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
• İstanbul Üniversitesi Adresli: Evet

Özet

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) remains a serious clinical concern with high morbidity and mortality rates. The emergence of MRSA isolates resistant to ceftaroline (CPT), which exhibits anti-MRSA activity, has necessitated the investigation of novel treatment options. Combinations of CPT-vancomycin (VAN) or CPT-daptomycin (DAP) are recommended for the treatment of serious MRSA infections. The study aimed to determine the effectiveness of CPT alone and in dual combinations against MRSA isolates.

Material and Methods: A total of 100 MRSA isolates obtained from clinical samples were included in the study. The disk diffusion method (DDM) was used to detect the susceptibility of routinely used antibiotics, while the broth microdilution (BMD) method was utilized for the detection of susceptibility against CPT, VAN and DAP. The evaluation of antibiotic susceptibility results was conducted in accordance with the established guidelines. The effectiveness of CPT-VAN and CPT-DAP combinations was investigated by the checkerboard method.

Results: The highest resistance rates in MRSA isolates were found for cotrimoxazole (77%), tetracycline (50%) and erythromycin (40%). Forty-one percent of all isolates had the iMLSb phenotype. Three isolates were resistant to CPT and two isolates were resistant to DAP. Resistance to CPT was found in 2.5% of blood stream infections (BSI) isolates, and 4.5% of skin and soft tissue infections isolates. The rate of “susceptible, increased exposure” to CPT was 56% using the BMD method and 2% using the DDM method. No VAN-intermediate- or VAN-resistant- S. aureus were detected. Both CPT-VAN and CPT-DAP combinations showed an indifference effect against CPT-resistant (CPT-R) isolates.

Conclusion: Despite the relatively low rate of CPT resistance detected in this study, concerns have been raised that the number of CPT-R isolates may increase over time. The indifferent effect of CPT in binary combinations highlights the necessity to test new synergistic antimicrobial combinations