Guang'anmen Hospital, Beijing University of Chinese Medicine, Beijing 100029, China.
Department of Emergency, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China.
J Tradit Chin Med. 2019 Dec;39(6):794-799.
To observe the effects of New Dayuan powder (NDYP) on Methicillin-resistant Staphylococcus aureus (MRSA) biofilms and the embedded bacteria in vitro.
2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assays were used to study the effects of NDYP on developing MRSA biofilms: 100 μL of bacterial culture and 100 μL drug solution were added to wells of 96-well plates. After 24 h of incubation, the plates were washed and XTT-phenazine methyl sulfate (PMS) was added to enable counting of the number of live bacteria in biofilms using a microplate reader. XTT assays were also used to explore the effects of NDYP on mature MRSA biofilms: 100 μL of bacterial culture were added to wells of 96-well plates. Bacteria were cultured in the plates for 24 h, and then drug solution was added. The plates were cultured for another 24 h, and then XTT-PMS was added to detect the number of live bacteria in the biofilms. Scanning electron microscopy (SEM) was used to observe the effects of NDYP on mature MRSA biofilms: washed and sterilized glass coverslips were added to 24-well plates. Bacterial culture was added. After 24 h of incubation, drug solution was added. After another 24 h of incubation, the samples were observed by SEM.
XTT assays showed that the number of live bacteria in both developing and mature MRSA biofilms decreased significantly (P < 0.01) after the administration of NDYP. SEM images showed that NDYP could destroy the structure of the bacteria and resulted in uneven thickness of MRSA biofilms.
In vitro, NDYP has obvious inhibitory effects on the formation of MRSA biofilms and on mature biofilms.
观察新达源粉（NDYP）对耐甲氧西林金黄色葡萄球菌（MRSA）生物膜及其嵌入细菌的体外作用。
采用 2,3-双（2-甲氧基-4-硝基-5-磺苯基）-2H-四唑-5-羧基苯胺（XTT）法研究 NDYP 对 MRSA 生物膜形成的影响：将 100 μL 细菌培养物和 100 μL 药物溶液加入 96 孔板的孔中。孵育 24 h 后，将平板洗涤，加入 XTT-吩嗪甲硫酸盐（PMS），用微孔板读数器计数生物膜中活细菌的数量。XTT 法还用于研究 NDYP 对成熟 MRSA 生物膜的影响：将 100 μL 细菌培养物加入 96 孔板的孔中。在平板中培养细菌 24 h，然后加入药物溶液。再培养平板 24 h，然后加入 XTT-PMS 以检测生物膜中活细菌的数量。扫描电子显微镜（SEM）用于观察 NDYP 对成熟 MRSA 生物膜的影响：将清洗和消毒的玻璃盖玻片加入 24 孔板中。加入细菌培养物。孵育 24 h 后，加入药物溶液。再孵育 24 h 后，用 SEM 观察样品。
XTT 法结果显示，NDYP 给药后，MRSA 生物膜形成过程中和成熟生物膜中的活菌数量均明显减少（P<0.01）。SEM 图像显示，NDYP 可破坏细菌的结构，导致 MRSA 生物膜的厚度不均匀。
体外，NDYP 对 MRSA 生物膜的形成及成熟生物膜均具有明显的抑制作用。
