Meerwein Milton, Tarnutzer Andrea, Böni Michelle, Van Bambeke Françoise, Hombach Michael, Zinkernagel Annelies S
Department of Infectious Diseases and Hospital Epidemiology, University of Zurich, 8091 Zurich, Switzerland.
Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, B-1200 Brussels, Belgium.
Antibiotics (Basel). 2020 Apr 29;9(5):218. doi: 10.3390/antibiotics9050218.
Increasing antibiotic resistances and a lack of new antibiotics render the treatment of Gram-negative bacterial infections increasingly difficult. Therefore, additional approaches are being investigated. Macrolides are not routinely used against Gram-negative bacteria due to lack of evidence of in vitro effectiveness. However, it has been shown that Pseudomonas spp. are susceptible to macrolides in liquid RPMI-1640 and clinical data suggest improvement in patients' outcomes. So far, these findings have been hardly applicable to the clinical setting due to lack of routine low-complexity antimicrobial susceptibility testing (AST) for macrolides. We therefore optimized and compared broth microdilution and disk diffusion AST. Multidrug-resistant Gram-negative bacteria () were tested for azithromycin susceptibility by disk diffusion and broth microdilution in Mueller-Hinton and RPMI-1640 media. Azithromycin susceptibility of Enterobacteriaceae and a subgroup of increased significantly on RPMI-1640 agar compared to Mueller-Hinton agar. Further, a significant correlation (Kendall, τ, ) of zone diameters and minimal inhibitory concentrations (MICs) was found on RPMI-1640 agar for (-0.4279, 0.0051), (-0.3783, 0.0237) and (-0.6477, <0.0001). Performing routine disk diffusion AST on RPMI-1640 agar may lead to the identification of additional therapeutic possibilities for multidrug-resistant bacterial infections in the routine clinical diagnostic setting.
抗生素耐药性不断增加且缺乏新型抗生素，使得革兰氏阴性菌感染的治疗愈发困难。因此，人们正在研究其他方法。由于缺乏体外有效性的证据，大环内酯类药物通常不用于治疗革兰氏阴性菌感染。然而，已有研究表明，假单胞菌属在液体RPMI - 1640培养基中对大环内酯类药物敏感，临床数据也显示患者的治疗效果有所改善。到目前为止，由于缺乏针对大环内酯类药物的常规低复杂性抗菌药物敏感性试验（AST），这些发现几乎无法应用于临床。因此，我们优化并比较了肉汤微量稀释法和纸片扩散法AST。通过在Mueller - Hinton培养基和RPMI - 1640培养基中采用纸片扩散法和肉汤微量稀释法，对多重耐药革兰氏阴性菌（）进行阿奇霉素敏感性测试。与Mueller - Hinton琼脂相比，肠杆菌科细菌和一个亚组在RPMI - 1640琼脂上的阿奇霉素敏感性显著增加。此外，在RPMI - 1640琼脂上，对于（-0.4279，0.0051）、（-0.3783，0.0237）和（-0.6477，<0.0001），发现抑菌圈直径与最低抑菌浓度（MICs）之间存在显著相关性（Kendall，τ，）。在RPMI - 1640琼脂上进行常规纸片扩散AST，可能会在常规临床诊断环境中发现多重耐药细菌感染的更多治疗可能性。
