【作者】 高燕； 蒋晓琼； 童忠春； 马可；

【Author】 Gao Yan;Jiang Xiaoqiong;Tong Zhongchun;Ma Ke;Guanghua School of Stomatology,Hospital of Stomatology,Sun Yat-sen University,Guangdong Provincial Key Laboratory of Stomatology;

【机构】 中山大学光华口腔医学院·附属口腔医院,广东省口腔医学重点实验室；

【摘要】 目的:探讨粪肠球菌与戈登链球菌、粘性放线菌、嗜酸乳杆菌及白色念珠菌饥饿态的相互竞争抑制。方法:分别取对数生长期细菌,调整初始浓度,四种细菌按照体积比1:1分别与粪肠球菌混合,饥饿共培养7、28天,每个时间点进行活菌计数,检查饥饿态细菌混合培养时生存能力;取共培养1天饥饿态混合细菌,通过qRT-PCR检测粪肠球菌应激基因表达变化。结果:粪肠球菌与戈登链球菌、粘性放线菌、嗜酸乳杆菌或白色念珠菌在饥饿态共培养28天,活菌数均>10~6CFU/mL,与单独饥饿时相比显著升高(P<0.05);白色念珠菌或嗜酸乳杆菌与粪肠球菌共培养时与单独培养时无统计学差异;戈登链球菌或粘性放线菌与粪肠球菌饥饿共培养无活菌生存。饥饿共培养1天粪肠球菌应激相关基因relA,gls24,dnaK,groEL及1dh表达上调。结论:饥饿态粪肠球菌与其他细菌共培养时生存能力增强,提示粪肠球菌具有更强的竞争抑制能力。更多还原

【Abstract】 Objective:The aim of this study was to investigate the mutual competitive inhibition between Enterococcus faecalis and Streptococcus gordonii,Actinomyces viscosus,Lactobacillus acidophilus,Candia albicans.Methods:S.gordonii,A.viscosus,L.acidophilus and C.albicans at an initial cell density were mixed in proportion with E.faecalis,respectively.At preset intervals,cell density was confirmed by viable counts of serial dilutions in water and plating on agar.The starved mixture cells at 1 day were collected by centrifugation and isolated total RNA.The expression of target genes was detected by qRT-PCR.Results:Cocultured E.faecalis survived starvation for 28 days with a viable cell population more than 10~6CFU/mL,and had significant difference in comparison to control group.While the other two bacteria L.acidophilus and C.albicans with a density show no difference as compared with control group.No S.gordonii,A.viscosus cells survived starvation after co-culturing for 28 days.Data showed that stress-related genes of E.faecalis,such as relA,gls24,dnaK,groEL and ldh,were up-regulated.Conclusion:The study indicates that co-cultured E.faecalis possesses a strong capacity for starvation survival and competitive inhibition.更多还原