Zhang Jingjia, Li Xue, Jia Xinmiao, Li Yun, Zheng Bo, Yu Yunsong, Hu Fupin, Sun Ziyong, Chen Zhongju, Zhang Ge, Kang Wei, Wang Tong, Li Jin, Gao Haotian, Yi Qiaolian, Yu Wei, Chu Xiaobing, Xu Yingchun, Yang Qiwen
Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People's Republic of China.
Clinical Biobank, Biomedical Engineering Facility of National Infrastructures for Translational Medicine, Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, Beijing, Peoples Republic of China.
Infect Drug Resist. 2025 Apr 23;18:1993-2004. doi: 10.2147/IDR.S501783. eCollection 2025.
To establish the epidemiological cut-off values (ECOFFs) of sitafloxacin against , and
We collected 2264 clinical isolates from five different labs located in four cities in China. The minimum inhibitory concentrations (MICs) and inhibition zone diameters of sitafloxacin for all isolates were determined by using the broth microdilution method (BMD) and the disk diffusion method according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. MIC ECOFFs were determined using ECOFFinder software, with the 99% calculated ECOFF selected as the initial value. Zone diameter ECOFFs were determined via the visual estimation method. Whole-genome sequencing was performed on strains exhibiting overlapping MICs between wild-type (WT) and non-wild-type (NWT) groups to analyze resistance mechanisms.
Sitafloxacin MICs ranged from 0.002 to 64 mg/L, while inhibition zone diameters ranged from 6 to 45 mm across the nine species. MIC ECOFFs were determined as 0.032, 0.064, 0.125, 0.5, 0.064, 0.125, 0.5, 0.25, and 0.125 mg/L for (tentative ECOFF), , and , respectively. Except for , MICs of the other eight species showed a high correlation with zone diameters (|r| > 0.8, P < 0.0001). Consequently, the zone diameter ECOFFs were established as 26, 25, 24, 24, 25, 26, 21, and 22 for , and , respectively.
We established MIC and zone diameter ECOFFs for sitafloxacin against the nine species listed above. The MIC ECOFF for was classified as tentative. For , the correlation between zone diameters and MICs was insufficient to establish a zone diameter ECOFF.
确定西他沙星对[具体菌种]的流行病学截断值（ECOFFs）。
我们从中国四个城市的五个不同实验室收集了2264株临床分离株。根据欧洲抗菌药物敏感性试验委员会（EUCAST）指南，采用肉汤微量稀释法（BMD）和纸片扩散法测定了所有分离株对西他沙星的最低抑菌浓度（MICs）和抑菌圈直径。使用ECOFFinder软件确定MIC ECOFFs，选择计算出的99% ECOFF作为初始值。通过视觉估计法确定抑菌圈直径ECOFFs。对野生型（WT）和非野生型（NWT）组之间MIC重叠的菌株进行全基因组测序，以分析耐药机制。
西他沙星的MIC范围为0.002至64 mg/L，九个菌种的抑菌圈直径范围为6至45 mm。[具体菌种1]、[具体菌种2]等的MIC ECOFFs分别确定为0.032、0.064、0.125、0.5、0.064、0.125、0.5、0.25和0.125 mg/L（暂定ECOFF）。除[具体菌种X]外，其他八个菌种的MIC与抑菌圈直径高度相关（|r|>0.8，P<0.0001）。因此，[具体菌种1]、[具体菌种2]等的抑菌圈直径ECOFFs分别确定为26、25、24、24、25、26、21和22。
我们确定了西他沙星对上述九个菌种的MIC和抑菌圈直径ECOFFs。[具体菌种X]的MIC ECOFF分类为暂定。对于[具体菌种Y]，抑菌圈直径与MIC之间的相关性不足以确定抑菌圈直径ECOFF。
