In vitro susceptibility of ceftaroline against clinically important Gram-positive cocci, Haemophilus species and Klebsiella pneumoniae in Taiwan: Results from the Antimicrobial Testing Leadership and Surveillance (ATLAS) in 2012–2018

Background/Purpose: Ceftaroline, with a unique activity against methicillin-resistant Staphylococcus aureus (MRSA), was not launched in Taiwan before 2019. The in vitro susceptibility data of ceftaroline against important Taiwanese pathogens are lacking. Methods: The in vitro susceptibility of ceftaroline against important pathogens collected from 2012 through 2018 were extracted from the Antimicrobial Testing Leadership and Surveillance program. Broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) to ceftaroline against all isolates. Results: During the study period, the in vitro data regarding isolates of S. aureus (n = 2049), Staphylococcus epidermidis (n = 185), Streptococcus pneumoniae (n = 334), Streptococcus pyogenes (n = 170), Haemophilus influenzae (n = 75), Haemophilus parainfluenzae (n = 10) and Klebsiella pneumoniae (n = 680) regardless of hospital sites of collection were analyzed. Among the S. aureus isolates studied, 19.4% showed MICs of 1 mg/L to ceftaroline, and 4.4% showed in vitro susceptible-dose dependent to ceftaroline (all MICs, 2 mg/L). Most of other Gram-positive cocci, all H. influenzae and H. parainfluenzae isolates were susceptible to ceftaroline. By contrast, about one-third (35.9%) of K. pneumoniae isolates, irrespective of infection sources, exhibited non-susceptibility to ceftaroline (MIC range, 0.015–256 mg/L; MIC₅₀ and MIC₉₀ values, 0.12 and 256 mg/L, respectively). Conclusions: From the pharmacodynamic perspectives, the ceftaroline dosage of 600 mg as a 2-h intravenous infusion every 8 h is effective against all S. aureus and other Gram-positive isolates regardless of acquisition sites in Taiwan. Before ceftaroline is prescribed in treatment of the patient with Gram-negative infection, a cautious evaluation about patient's healthcare-associated factor is warranted.