Aoki Wataru, Uwamino Yoshifumi, Niida Nagi, Kubota Hiroaki, Kamoshita Yuka, Inose Rika, Nagata Mika, Ishihara Osamu, Uno Shunsuke, Yoshifuji Ayumi, Namkoong Ho, Hasegawa Naoki, Matsushita Hiromichi
Clinical Laboratory, Keio University Hospital, Tokyo, Japan.
Department of Laboratory Medicine, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan; Department of Infectious Diseases, Keio University School of Medicine, Tokyo, Japan.
J Glob Antimicrob Resist. 2025 Jul 7;44:251-255. doi: 10.1016/j.jgar.2025.07.004.
Cefiderocol, a siderophore cephalosporin, has shown promise against carbapenem-resistant strains such as Pseudomonas aeruginosa and Stenotrophomonas maltophilia species complex. Despite its recent approval in Japan, susceptibility data remain limited. Therefore, this study evaluated the cefiderocol susceptibility of carbapenem-resistant P. aeruginosa and S. maltophilia species complex strains isolated from blood cultures to determine whether cefiderocol can be used as an empirical treatment option.
Carbapenem-resistant P. aeruginosa and S. maltophilia species complex strains isolated from blood cultures at a university hospital in Japan were included. Minimum inhibitory concentrations (MICs) and inhibition zone diameters were assessed using broth microdilution and disk diffusion methods, respectively. Whole-genome sequencing was conducted to elucidate the genetic backgrounds of the clinical isolates.
The MIC and MIC values for cefiderocol in 65 carbapenem-resistant P. aeruginosa strains were 0.12 and 0.25 µg/mL, and 0.06 and 0.25 µg/mL for 51 S. maltophilia species complex strains, respectively. One S. maltophilia species complex strain exhibited non-susceptibility, with a MIC of 2 µg/mL in broth microdilution, while disk diffusion methods demonstrated susceptibility. A significant negative correlation was observed between MIC values and inhibition zone diameters. Whole-genome sequencing revealed that a limited number of P. aeruginosa strains possessed carbapenemase genes.
The findings of this study support the efficacy of cefiderocol against carbapenem-resistant P. aeruginosa and S. maltophilia species complex, suggesting its potential as an empirical treatment option for bloodstream infection patients in Japan. Continued surveillance is advised to monitor resistance trends with increased cefiderocol use.
头孢地尔，一种铁载体头孢菌素，已显示出对碳青霉烯耐药菌株如铜绿假单胞菌和嗜麦芽窄食单胞菌复合种有治疗前景。尽管其最近在日本获得批准，但药敏数据仍然有限。因此，本研究评估了从血培养中分离出的碳青霉烯耐药铜绿假单胞菌和嗜麦芽窄食单胞菌复合种菌株对头孢地尔的敏感性，以确定头孢地尔是否可作为经验性治疗选择。
纳入从日本一家大学医院血培养中分离出的碳青霉烯耐药铜绿假单胞菌和嗜麦芽窄食单胞菌复合种菌株。分别采用肉汤微量稀释法和纸片扩散法评估最低抑菌浓度（MIC）和抑菌圈直径。进行全基因组测序以阐明临床分离株的遗传背景。
65株碳青霉烯耐药铜绿假单胞菌菌株对头孢地尔的MIC值分别为0.12和0.25μg/mL，51株嗜麦芽窄食单胞菌复合种菌株对头孢地尔的MIC值分别为0.06和0.25μg/mL。1株嗜麦芽窄食单胞菌复合种菌株表现为不敏感，肉汤微量稀释法测得的MIC为2μg/mL，而纸片扩散法显示敏感。观察到MIC值与抑菌圈直径之间存在显著负相关。全基因组测序显示，少数铜绿假单胞菌菌株携带碳青霉烯酶基因。
本研究结果支持头孢地尔对碳青霉烯耐药铜绿假单胞菌和嗜麦芽窄食单胞菌复合种的疗效，表明其在日本作为血流感染患者经验性治疗选择的潜力。建议持续监测以监测随着头孢地尔使用增加的耐药趋势。
