拮抗金黄色葡萄球菌的益生菌菌株的筛选及初步研究

Screening and preliminary study of probiotic strains against Staphylococcus aureus

目的:分离筛选对金黄色葡萄球菌的有生物拮抗作用的益生菌菌株,并对培养条件进行优化,为临床合理应用益生菌提供实验依据。方法:从市售酸奶制品中分离培养获得益生菌菌株,采用牛津杯法初步筛选具有拮抗金黄色葡萄球菌的乳酸杆菌菌株。通过正交实验法对拮抗菌株温度、培养时间、pH值及接种量进行优化,并检测其对金黄色葡萄球菌的拮抗性。采用MTT法检测拮抗菌株对A549细胞增殖的影响。结果:筛选获得1株乳酸杆菌菌株,菌株最佳培养条件为接种量为10%,pH值为5.5,拮抗菌株温度为32℃,培养时间为36h,该条件下乳酸杆菌菌株对耐药性金黄色葡萄球菌的抑制能力强。MTT法结果显示拮抗菌株对A549细胞增殖无影响。结论:初步获得1株乳酸杆菌益生菌菌株,其对耐药性金黄色葡萄球菌具有生物拮抗作用。

Objective: To isolate and screen the probiotic strains with biological antagonism against Staphylococcus aureus and to optimize culture conditions in order to provide experimental basis for rational clinical application of probiotics. Methods: Probiotic strains were isolated and cultured from yoghurt products on the market. Lactobacillus strains antagonizing Staphylococcus aureus were preliminarily screened by Oxford cup method. The temperature, culture time, pH value and inoculation amount of one of the antagonistic strains were optimized by orthogonal experiment, and its antagonism to Staphylococcus aureus was tested. MTT assay was used to detect the effect of the antagonistic strain on the proliferation of A549 cells. Results: A strain of Lactobacillus was screened out. The optimum culture conditions were inoculation amount of 10%, pH value of 5.5, temperature of 32 ℃ and culture time of 36 hours. Under these conditions, the strain of Lactobacillus had strong inhibition ability to drug-resistant Staphylococcus aureus. MTT assay showed that it had no effect on cell proliferation. Conclusion: A probiotic strain of Lactobacillus is preliminarily obtained, which has biological antagonism against drug-resistant Staphylococcus aureus.