2025/01/01 by Bing Lu, Wenjiao Chang, Huaiwei Lu +8 · 1 voice
Medicine · Biochemistry, Genetics and Molecular Biology · #Antimicrobial Resistance in Staphylococcus #Bacterial Identification and Susceptibility Testing #Antibiotic Resistance in Bacteria
paper · doi:10.1016/j.dcit.2025.100052
openalex publication_date 2025/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
Objective Staphylococcus aureus bacteremia is a critical and pernicious infection, and in particular methicillin-resistant Staphylococcus aureus (MRSA) is increasing in treatment failure. This study analyzed trends in the minimum inhibitory concentrations (MICs) of limited antimicrobials against MRSA bloodstream isolates in China; specifically, the antibiotics vancomycin, daptomycin, linezolid, and teicoplanin. Methods A total of 3901 S. aureus blood isolates, including 1065 MRSA isolates, were collected from ten Chinese provinces between 2017 and 2022. Broth microdilution was used to establish the MICs for the four antimicrobials. The geometric mean MICs (GM MICs), MIC50s (inhibition of 50 % of S. aureus ), MIC90s (inhibition of 90 % of S. aureus ), and MICs distribution were determined for each year. Results The geometric mean inhibitory concentration of vancomycin for MRSA isolates increased from 0.58 mg/L in 2018 to 1.01 mg/L by 2022; and that of linezolid decreased from 1.52 mg/L in 2017 to 0.94 mg/L in 2022. Daptomycin and teicoplanin demonstrated no clear trends. MRSA isolates with vancomycin MICs ≤0.5 mg/mL significantly decreased from 77.1 % in 2018 to 8.8 % in 2022. For linezolid, those with MICs >1 and ≤ 2 mg/L also decreased from 62.8 % in 2017 to 26.1 % in 2022. The highest geometric mean MICs of daptomycin, linezolid, vancomycin, and teicoplanin were respectively seen in Yunnan (0.465 mg/L), Henan (1.368 mg/L), Gansu (0.908 mg/L), and Hubei (0.579 mg/L); whereas the lowest values were observed in Jiangxi (0.355 mg/L), Yunnan (0.896 mg/L), Yunnan (0.600 mg/L), and Henan (0.438 mg/L). MRSA isolates originating from tertiary care hospitals exhibited lower sensitivity for teicoplanin than those from non-tertiary care hospitals. Conclusions MRSA isolates from bloodstream infections in China are presently showing lower sensitivity to vancomycin and higher sensitivity to linezolid.