Barnesiella intestinihominis菌的安全性评价

Safety evaluation of Barnesiella intestinihominis bacteria

目的:对分离自健康成人粪便中且在代谢性疾病发生状态下生长可能受到抑制的Barnesiella(巴恩斯氏菌属)厌氧菌进行体内外生物安全性评价,为今后代谢性疾病的微生态制剂的研发与应用提供基础。方法:通过急性毒性试验,连续14 d给昆明鼠灌胃不同剂量的Barnesiella intestinihominis(B.intestinihominis)菌培养液,观察动物是否出现死亡、中毒现象以及观察体重、生化指标的变化进行体内安全性评价。通过溶血性实验,胃酸和肠液的耐受性实验,以及其对9种抗生素的敏感性实验来进行体外评价。结果:实验组均未出现B.intestinihominis菌灌胃导致的死亡,中毒现象,其体重和脏器指数同对照组相比差异无统计学意义(P>0.05),各脏器也未出现任何病理学变化。B.intestinihominis菌在哥伦比亚血琼脂平板上不产生溶血环,属于γ溶血;其胃酸耐受性不强,但肠液耐受性良好,对氯霉素、氨苄西林、万古霉素和四环素敏感,但是对链霉素、红霉素、卡那霉素、庆大霉素、克林霉素耐药。结论:口服B.intestinihominis菌株对小鼠无毒性作用,具有良好的体内安全性,其胃酸耐受性不强,对革兰阴性菌有作用的抗生素敏感,若作为微生态制剂还需要验证对不同疾病的有益效果以及需要制作保护剂。

Objective:To evaluate the biosafety of B.intestinihominis in vivo and in vitro,which was an anaerobic bacterium isolated from the feces of healthy adults and whose growth is inhibited in many metabolic disease states,in order to provide a basis for the research and development of microbial ecological agents for metabolic diseases in the future.Methods:The in vivo safety evaluation was carried out by acute toxicity test by gavage of different doses of B.intestinihominis cultures to Kunming rats for 14 consecutive days to observe whether the animals showed any death and toxicity,as well as changes in body weight,biochemical indexes,and abundance of intestinal B.intestinihominis bacteria.In vitro evaluation was performed by hemolytic assay,tolerance assay of gastric acid and intestinal fluid,and sensitivity assay of 9 antibiotics.Results:None of the experimental groups showed any mortality,toxicity due to gavage of the B.intestinihominis,and the differences in their body weights and organ indices were not statistically significant compared to the control group(P>0.05),nor did they show any pathological changes in the organs.Barnesiel⁃la intestinihominis did not produce a hemolytic ring on Columbia blood agar plates and was gamma-hemolytic.It was not well tolerated by gastric acid but well tolerated by intestinal fluids,and was sensitive to chloramphenicol,ampicillin,vancomycin and tetracycline,but resistant to streptomycin,erythromycin,kanamycin,gentamicin and clindamycin.Conclusion:Oral administration of B.intestinihominis strains has no toxic effect on mice and has a good in vivo safety profile,it is not well tolerated by gastric acid and is sensitive to antibiotics that have a role for gram-negative bacteria,if used as a microcosmic agent it needs to be verified for its beneficial effects on different diseases as well as the need to make a protective agent.