亚甲蓝对体外不同细菌培养结果的影响△

Impacts of methylene blue on culture results of different bacteria in vitro

摘要:

［目的］探讨分析染色剂亚甲蓝（methylene blue, MB），一种通常用作关节假体周围感染的示踪剂阳离子染料，对体外不同细菌培养结果的影响。［方法］体外制备 8 种标准菌株，包括金黄色葡萄球菌（staphylococcus aureus, SAU）、表皮葡萄球菌 （staphylococcus epidermidis, SEP）、人葡萄球菌 （staphylococcus hominis, SHO）、大肠杆菌 （escherichia coli, ECO）、肺炎克雷伯菌 （klebsiella pneumoniae, KPN）、鲍曼不动杆菌 （acinetobacter baumannii, ABA）、化脓链球菌 （streptococcus pyogenes, SPY） 和白色念珠菌 （candida albicans, CAL） 的菌悬液来模拟关节液细菌培养。所有标准菌株的菌悬液均稀释 50 倍，并分为三组 （每组 5 份），分别添加 0.1%MB、0.05%MB 和 0.45%无菌盐水。接种于琼脂平板培养基培养 24 h，比较三组的菌落计数。［结果］ SHO 和 ABA 菌落计数由低至高依次为 0.1%MB 组 <0.05%MB 组<盐水组，差异有统计学意义 （P<0.05）。而 SEP、ECO、 KPN、SPY 和 CAL 的菌落计数三组间差异均无统计学意义（P>0.05）。Spearman 相关分析表明，MB 浓度与 SHO 和 ABA 菌落计数呈显著负相关 （P<0.05），而与 SAU、SEP、ECO、KPN、SPY、CAL 的菌落计数无相关性 （P>0.05）。［结论］ MB 对 SHO 和 ABA 有剂量依赖性抑菌作用，但对其他 6 个菌株无作用。

Abstract:

[Objective] To explore the impacts of methylene blue (MB) , a cationic dyes usually used as tracer agent for periprosthetic joint infection, on the culture results of different bacteria in vitro. [Methods] Eight standard bacterial strains were prepared in vitro, includ- ing staphylococcus aureus (SAU) , staphylococcus epidermidis (SEP) , staphylococcus hominis (SHO) , escherichia coli (ECO) , klebsiella pneumoniae (KPN) , bacterial suspensions of acinetobacter baumannii (ABA) , streptococcus pyogenes (SPY) and candida albicans (CAL) , for simulation of bacterial culture of synovial fluid. The bacterial suspensions of all the standard bacterial strains were diluted 50 times and divided into three groups with 5 samples in each group, and then treated with 0.1%MB and 0.05%MB and 0.45% sterile saline, respective- ly. The colony count was compared among the 3 groups. [Results] The colony counts of SHO and ABA strains were ranked from low to high in sequence of 0.1%MB group ＜0.05% MB group ＜ saline group, with a statistically significant difference (P＜0.05) . However, there were no significant differences in colony counts in terms of SEP, ECO, KPN, SPY and CAL among the 3 groups (P＞0.05) . As results of Spear- man correlation analysis, the MB concentration was significantly negatively correlated with SHO and ABA colony counts (P＜0.05) , whereas which had no correlation with colony counts of SAU, SEP, ECO, KPN, SPY and CAL (P＞0.05). [Conclusion] The MB has dose-dependent inhibitory effect on SHO and ABA, but has no effect on the other 6 bacterial strains.