拮抗金黄色葡萄球菌的细菌分离及其作用机制

Isolation of antagonistic bacteria against Staphylococcus aureus and its mechanism

细菌耐药性问题越来越严重,迫切需要研发新型抗菌药物。而拮抗性细菌可以产生抗菌活性物质,在对抗耐药性细菌方面具有潜力。本研究以耐甲氧西林的金黄色葡萄球菌USA300为指示菌,从污水中分离并纯化得到1株拮抗性菌株H223,通过16S rRNA测序结果显示属于芽孢杆菌属,H223对指示菌USA300表现出较高的抑菌活性,并对葡萄球菌属均表现出不同程度的抑菌效果。对H223发挥抑菌活性物质进行研究,确认其存在于培养上清中。在液体培养基中静置培养36 h抑菌活性最强,最后结合超滤管和蛋白酶K处理判断H223培养上清中的抑菌活性物质为非蛋白类小分子。综上所述,该研究获得的拮抗性菌株H223培养物具有显著拮抗耐药性金黄色葡萄球菌作用,为新型抑菌成分的进一步研究和应用奠定基础。

The problem of bacterial drug resistance is more and more serious,so it is urgent to develop new antibacterial drugs.However,antagonistic bacteria can produce antibacterial active substances,which have potential in resistance to drug-resistant bacteria.In this study,an antagonistic strain H223 was isolated and purified from wastewater by using methicillin-resistant Staphylococcus aureus USA300 as indicator bacteria.The results of 16 S rRNA sequencing showed that it belonged to Bacillus,and H223 showed high antibacterial activity against indicator bacteria USA300,and different degrees of antibacterial effect on Staphylococcus.Then the H223 bacteriostatic active substances,which existed in the culture supernatant was studied.The optimal conditions for its production were determined as 36 h culture in liquid medium and-80℃ storage.Finally,combined with the treatment of ultrafiltration tube and protease K,determined that the antibacterial active substance in H223 culture supernatant was nonprotein small molecule.To sum up,the antagonistic strain H223 culture obtained in this study has significant antagonistic effect on drug-resistant Staphylococcus aureus,which laid a foundation for further research and application of new antibacterial components.