Malá Zuzana, Žárská Ludmila, Bajgar Robert, Bogdanová Kateřina, Kolář Milan, Panáček Aleš, Binder Svatopluk, Kolářová Hana
Department of Medical Biophysics, Faculty of Medicine and Dentistry, Palacky University in Olomouc, Czech Republic.
Department of Microbiology, Faculty of Medicine and Dentistry, Palacky University in Olomouc, Czech Republic.
Photodiagnosis Photodyn Ther. 2021 Mar;33:102140. doi: 10.1016/j.pdpdt.2020.102140. Epub 2020 Dec 8.
As resistance of bacterial strains to antibiotics is a major problem, there is a need to look for alternative treatments. One option is antimicrobial photodynamic inactivation (aPDI). The pathogenic cells are targeted by a nontoxic photosensitizer while the surrounding healthy tissue is relatively unaffected. The photosensitizer is activated by light of t appropriate wavelength resulting in the generation of reactive oxygen species that are cytotoxic for the pathogens. In this work, the photosensitizer TMPyP and silver nanoparticles (AgNPs) were investigated for their synergistic antibacterial effect. We tested these two substances on two bacterial strains, methicillin-resistant Staphylococcus aureus 4591 (MRSA) and extended-spectrum beta-lactamases-producing Klebsiella pneumoniae 2486 (ESBL-KP), to compare their effectiveness. The bacteria were first incubated with TMPyP for 45 min or 5 h, then irradiated with a LED source with the total fluence of 10 or 20 J/cm and then placed in a microbiological growth medium supplemented with AgNPs. To accomplish the synergistic effect, the optimal combination of TMPyP and AgNPs was estimated as 1.56-25 μM for TMPyP and 3.38 mg/l for AgNPs in case of MRSA and 1.56-50 μM for TMPyP and 3.38 mg/l for AgNPs in case of ESBL-KP at 45 min incubation with TMPyP and fluence of 10 J/cm. Longer incubation and/or longer irradiation led to a decrease in the maximum values of the photosensitizer concentration to produce the synergistic effect. From this work it can be concluded that the combination of antimicrobial photodynamic inactivation with a treatment including silver nanoparticles could be a promising approach to treat bacterial infection.
由于细菌菌株对抗生素的耐药性是一个主要问题，因此需要寻找替代治疗方法。一种选择是抗菌光动力灭活（aPDI）。无毒的光敏剂靶向致病细胞，而周围的健康组织相对不受影响。光敏剂被适当波长的光激活，从而产生活性氧，这些活性氧对病原体具有细胞毒性。在这项工作中，研究了光敏剂四甲基吡啶卟啉（TMPyP）和银纳米颗粒（AgNPs）的协同抗菌作用。我们在两种细菌菌株上测试了这两种物质，即耐甲氧西林金黄色葡萄球菌4591（MRSA）和产超广谱β-内酰胺酶的肺炎克雷伯菌2486（ESBL-KP），以比较它们的有效性。细菌首先与TMPyP孵育45分钟或5小时，然后用总通量为10或20 J/cm的发光二极管（LED）光源照射，然后置于补充有AgNPs的微生物生长培养基中。为了实现协同效应，对于MRSA，TMPyP和AgNPs的最佳组合估计为TMPyP为1.56 - 25 μM，AgNPs为3.38 mg/l；对于ESBL-KP，在与TMPyP孵育45分钟且通量为10 J/cm的情况下，TMPyP为1.56 - 50 μM，AgNPs为3.38 mg/l。更长时间的孵育和/或更长时间的照射导致产生协同效应的光敏剂浓度最大值降低。从这项工作可以得出结论，抗菌光动力灭活与包括银纳米颗粒在内的治疗方法相结合可能是治疗细菌感染的一种有前途的方法。
