Comparison of methods to detect the in vitro activity of silver nanoparticles (AgNP) against multidrug resistant bacteria.
Comparison of methods to detect the in vitro activity of silver nanoparticles (AgNP) against multidrug resistant bacteria.
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DOI：
10.1186/s12951-015-0120-6
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发表时间：
2015-10-05
影响因子：
10.2
通讯作者：
Costa SF
中科院分区：
文献类型：
--
作者：
Cavassin ED;de Figueiredo LF;Otoch JP;Seckler MM;de Oliveira RA;Franco FF;Marangoni VS;Zucolotto V;Levin AS;Costa SF
多重耐药微生物是一个日益增长的挑战，需要可用于治疗这些微生物引起的感染的新物质。银纳米颗粒可能是治疗这些感染的未来选择，然而，体外评估抑制作用的方法存在争议。本研究评价了银纳米颗粒对来自临床来源的36种敏感和54种多重耐药革兰氏阳性和革兰氏阴性细菌的体外活性。多重耐药菌为耐苯唑西林金黄色葡萄球菌、耐万古霉素肠球菌、碳青霉烯和多粘菌素B耐药A.鲍曼不动杆菌、耐碳青霉烯类铜绿假单胞菌和耐碳青霉烯类肠杆菌科。我们分析了用柠檬酸盐、壳聚糖和聚乙烯醇稳定的银纳米颗粒和商业银纳米颗粒。以磺胺嘧啶银和硝酸银为对照。采用琼脂扩散法、最低抑菌浓度法、最低杀菌浓度法和时间杀灭法。AgNPs在固体培养基中的扩散和MIC方法的活性对MDR和抗生素敏感菌株显示出相似的效果，对革兰氏阴性菌株具有更高的效果。柠檬酸盐和壳聚糖银纳米颗粒获得了更好的结果，两者的MIC 90均为6.75 μg mL−1，这可能是由于这些颗粒的稳定性较低，因此释放了Ag+离子，如X射线衍射（XRD）所示。对抗菌药物敏感细菌的杀菌效果更高。琼脂扩散法似乎可以用作筛选试验，最低抑菌浓度/最低杀菌浓度和时间杀菌法是有用的方法。商业银纳米颗粒和银对照的活性没有超过柠檬酸盐和壳聚糖银纳米颗粒的活性。体外抑菌效果对革兰氏阴性菌强于革兰氏阳性菌，对多重耐药菌和敏感菌的抑菌效果相似，其中柠檬酸盐和壳聚糖银纳米粒的抑菌效果最好。银纳米颗粒的杀菌作用在未来可能转化为重要的治疗和临床选择，特别是考虑到针对新兴的抗微生物剂耐药性微生物，特别是针对革兰氏阴性菌的新抗微生物剂的短缺。
Multidrug resistant microorganisms are a growing challenge and new substances that can be useful to treat infections due to these microorganisms are needed. Silver nanoparticle may be a future option for treatment of these infections, however, the methods described in vitro to evaluate the inhibitory effect are controversial. This study evaluated the in vitro activity of silver nanoparticles against 36 susceptible and 54 multidrug resistant Gram-positive and Gram-negative bacteria from clinical sources. The multidrug resistant bacteria were oxacilin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus spp., carbapenem- and polymyxin B-resistant A. baumannii, carbapenem-resistant P. aeruginosa and carbapenem-resistant Enterobacteriaceae. We analyzed silver nanoparticles stabilized with citrate, chitosan and polyvinyl alcohol and commercial silver nanoparticle. Silver sulfadiazine and silver nitrate were used as control. Different methods were used: agar diffusion, minimum inhibitory concentration, minimum bactericidal concentration and time-kill. The activity of AgNPs using diffusion in solid media and the MIC methods showed similar effect against MDR and antimicrobial-susceptible isolates, with a higher effect against Gram-negative isolates. The better results were achieved with citrate and chitosan silver nanoparticle, both with MIC90 of 6.75 μg mL−1, which can be due the lower stability of these particles and, consequently, release of Ag+ ions as revealed by X-ray diffraction (XRD). The bactericidal effect was higher against antimicrobial-susceptible bacteria. It seems that agar diffusion method can be used as screening test, minimum inhibitory concentration/minimum bactericidal concentration and time kill showed to be useful methods. The activity of commercial silver nanoparticle and silver controls did not exceed the activity of the citrate and chitosan silver nanoparticles. The in vitro inhibitory effect was stronger against Gram-negative than Gram-positive, and similar against multidrug resistant and susceptible bacteria, with best result achieved using citrate and chitosan silver nanoparticles. The bactericidal effect of silver nanoparticle may, in the future, be translated into important therapeutic and clinical options, especially considering the shortage of new antimicrobials against the emerging antimicrobial resistant microorganisms, in particular against Gram-negative bacteria.