ε-聚赖氨酸对金黄色葡萄球菌生长及生物膜形成的影响#br#

目的 研究ε-聚赖氨酸(ε-poly-L-lysine, ε-PL)对金黄色葡萄球菌(Staphylococcus aureus, S. aureus)生长及生物膜形成的影响。方法 以金黄色葡萄球菌标准菌株ATCC25923及社区获得性耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus, MRSA)USA300为试验菌株，常量肉汤稀释法(试管)测定最低抑菌浓度(minimum inhibitory concentration, MIC)，酶标仪检测吸光度法观察各株金黄色葡萄球菌的生长曲线，96孔板结晶紫染色法检测各株菌生物膜的形成并用扫描电子显微镜(SEM)观察生物膜的形成情况。结果 ε-PL对ATCC25923和USA300的MIC均为31.25mg/mL。ε-PL浓度升高时对两株菌生长的抑制作用随之增强。1/2MIC ε-PL能显著降低ATCC25923和USA300生物膜的形成能力。 结论 ε-PL作为一种安全、高效的天然防腐剂，能有效抑制金黄色葡萄球菌细菌的生长及生物膜的形成，为新型药物的研发提供了理论依据。

Effects of ε-PL on growth and biofilm formationof Staphylococcus aureus

Objective To study the effects of ε-poly-L-lysine (ε-PL) on the growth and biofilm formation of Staphylococcus aureus (S. aureus). Methods S. aureus standard strain ATCC25923 and community-acquired methicillin-resistant S. aureus (MRSA) USA300 were used as test strains and the constant broth dilution method (test tube) was performed to determine the minimum inhibitory concentration (MIC). The growth curve of S. aureus was observed by spectrophotometry, the formation of biofilm in each strain was detected by 96-well crystal violet dyeing method and biofilm formation was observed with a scanning electron microscope (SEM). Results The MIC of the ε-PL on ATCC25923 and USA300 was 31.25mg/mL. And with the increase of ε-PL concentration, the inhibitory effect on the growth of two strains was gradually enhanced. 1/2 MIC ε-PL can significantly reduce the biofilm formation of ATCC25923 and USA300. Conclusion ε-PL as a safe and efficient natural preservative, significantly inhibited the growth of S. aureus bacteria and biofilm formation, and provided the theoretical basis for the development of new antimicrobial drugs.