Díaz-Navarro Marta, Cercenado Emilia, Visedo Andrés, Marín Mercedes, Machado Marina, Irigoyen-von-Sierakowski Álvaro, Loeches Belén, Cacho-Calvo Juana, García-Rodríguez Julio, Di Domenico Enea G, Muñoz Patricia, Guembe María
Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain.
Instituto de Investigación Sanitaria Gregorio Marañón, 28009 Madrid, Spain.
Antibiotics (Basel). 2025 Jul 23;14(8):738. doi: 10.3390/antibiotics14080738.
: Cefideroccol (FDC) is a siderophore cephalosporin with potent antibacterial activity against a wide range of Gram-negative multidrug-resistant (MDR) microorganisms. We investigated the anti-biofilm capacity of FDC against clinical strains. : This multicenter study was conducted on 28 selected strains of MDR Gram-negative bacilli isolated from clinical samples of (n = 5), (n = 11), and (n = 12). We first determined the minimum inhibitory concentration (MIC) of each strain using the microdilution method. We also defined the minimum biofilm inhibitory concentration (MBIC) as a ≥50% reduction in tetrazolium salt (XTT) (as recommended in the 2017 Spanish Microbiology Protocols [SEIMC] for the microbiological diagnosis of infections related to the formation of biofilms). We also analyzed the reduction in the following biofilm variables after an 8 mg/mL FDC treatment: the CFU count, the cell viability, the biomass, the metabolic activity, and extracellular α or β polysaccharides. : The MIC and MBIC of FDC were 0.5 mg/L and 64 mg/L, respectively. We observed a mean (SD) fold increase in the susceptibility to FDC between planktonic and sessile cells for , , and of 9.60 (0.55), 6.27 (2.28), and 6.25 (2.80), respectively. When 8 mg/mL of FDC was tested, we observed that the best median (IQR) percentage reductions were obtained for cell viability and the extracellular matrix (73.1 [12.4-86.5] and 79.5 [37.3-95.5], respectively), particularly for . The lowest percentage reduction rates were those obtained for biomass. : We demonstrated that the susceptibility to FDC was significantly reduced when strains were in a biofilm state. The best percentage reduction rates for all biofilm-defining variables were observed for . Our results need to be validated using a larger collection of clinical samples.
头孢地尔（FDC）是一种铁载体头孢菌素，对多种革兰氏阴性多药耐药（MDR）微生物具有强大的抗菌活性。我们研究了FDC对临床菌株的抗生物膜能力。：本多中心研究针对从（n = 5）、（n = 11）和（n = 12）的临床样本中分离出的28株MDR革兰氏阴性杆菌进行。我们首先使用微量稀释法确定每种菌株的最低抑菌浓度（MIC）。我们还将最低生物膜抑制浓度（MBIC）定义为四唑盐（XTT）降低≥50%（如2017年西班牙微生物学协议[SEIMC]中关于与生物膜形成相关感染的微生物学诊断所推荐）。我们还分析了8 mg/mL FDC处理后以下生物膜变量的降低情况：菌落形成单位（CFU）计数、细胞活力、生物量、代谢活性以及细胞外α或β多糖。：FDC的MIC和MBIC分别为0.5 mg/L和64 mg/L。我们观察到，对于、和，浮游细胞与固着细胞对FDC的敏感性平均（标准差）增加倍数分别为9.60（0.55）、6.27（2.28）和6.25（2.80）。当测试8 mg/mL的FDC时，我们观察到细胞活力和细胞外基质的中位数（四分位间距）降低百分比最佳（分别为73.1 [12.4 - 86.5]和79.5 [37.3 - 95.5]），特别是对于。降低百分比最低的是生物量。：我们证明，当菌株处于生物膜状态时，对FDC的敏感性显著降低。观察到对所有生物膜定义变量降低百分比最佳的是。我们的结果需要使用更大规模的临床样本集进行验证。
