Antimicrobial activities of sitafloxacin and comparators against the clinical isolates of less common nonfermenting Gram-negative bacteria.

OBJECTIVES:To evaluate in vitro activities of sitafloxacin and comparators against the clinical isolates of less common nonfermenting Gram-negative bacteria (NFGNB). METHODS:The isolates of less common NFGNB were collected during a long period spanning five years from 2016 to 2020 in Huashan Hospital, Fudan University in Shanghai. A broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) of sitafloxacin and comparators. RESULTS:In terms of MIC50/90 values, sitafloxacin was highly active against Stenotrophomonas maltophilia (0.25/1 mg/L), Burkholderia cepacia complex (0.25/2 mg/L), Achromobacter xylosoxidans (0.25/1 mg/L), and Chryseobacterium gleum (1/2 mg/L), but less active for Elizabethkingia (1/8 mg/L) and Chryseobacterium indologenes (16/32 mg/L). Sitafloxacin was more active than other fluoroquinolones against these NFGNB except Chryseobacterium. CONCLUSION:The results are helpful for clinicians to be aware of the role of sitafloxacin in managing the infections caused by these NFGNB.