猪链球菌生物被膜的生物学特性及噬菌体裂解酶对生物被膜的降解作用
发布时间：2019-04-26 02:35
【摘要】：猪链球菌(Streptococcus suis,SS)是一种重要的人畜共患病病原,能导致仔猪患脑膜炎、败血症、关节炎、心内膜炎、肺炎和人的脑膜炎。猪链球菌2型流行最广,对猪的致病力也最强,给养猪业造成了巨大的经济损失,在公共卫生方面,也对相关从业人员的生命安全构成了威胁。更为严重的是,当猪链球菌形成生物被膜时,生物被膜会为细菌提供一种保护性生活方式,可能会大大提高其抗逆性和致病性。本文研究了猪链球菌生物被膜的生物学特性,发现大部分猪链球菌均具有不同程度形成生物被膜的能力,其中10株(10/32)具备较强的生物被膜形成能力,猪链球菌生物被膜的成熟约需60 h,培养基中葡萄糖浓度是影响生物被膜形成的重要因素。胞外多糖是生物被膜的重要组成部分,多糖测定结果显示生物被膜中的多糖含量显著高于浮游菌。氨苄青霉素钠和阿莫西林对5株(5/10)猪链球菌生物被膜的最低抑菌浓度(MIC)和最低杀菌浓度(MBC)均高于浮游菌约2500倍。扫描电镜观察发现,生物被膜内猪链球菌彼此粘连,形成致密的三维立体结构。分别用抗生素、噬菌体SMP和裂解酶LySMP处理生物被膜,结果显示:正常剂量抗生素(20μg/ml)对生物被膜结构的破坏作用和对被膜菌的杀灭作用均不明显;噬菌体SMP既不能有效杀灭被膜菌也不能有效破坏生物被膜结构;裂解酶LySMP可以在12 h以内杀灭几乎所有的SS2-4和SS2-H生物被膜菌,并清除它们80%以上的生物被膜。对猪链球菌生物被膜生物学特性及降解方法的研究可为进一步揭示生物被膜的形成机制、耐药机理,以及清除生物被膜等提供理论依据。
[Abstract]:Streptococcus suis (Streptococcus suis,SS) is an important zoonotic pathogen that causes meningitis septicemia arthritis endocarditis pneumonia and human meningitis in piglets. Streptococcus suis type 2 has the most widespread prevalence and the strongest virulence to pigs, which has caused huge economic losses to pig industry. In public health, it also poses a threat to the life safety of relevant employees. More seriously, when Streptococcus suis forms biofilm, biofilm will provide a protective lifestyle for bacteria, which may greatly improve its resistance and pathogenicity. The biological characteristics of Streptococcus suis biofilm were studied in this paper. It was found that most Streptococcus suis had the ability to form biofilm in varying degrees, among which 10 strains (10 渭 32) had strong biofilm forming ability. It takes about 60 hours to mature the biofilm of Streptococcus suis. Glucose concentration in the culture medium is an important factor influencing the formation of biofilm. Exopolysaccharide is an important part of biofilm. The content of polysaccharide in biofilm is significantly higher than that of P. aeruginosa. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of ampicillin sodium and amoxicillin on the biofilm of Streptococcus suis were 2500 times higher than those of S. suis. Scanning electron microscopy (SEM) showed that Streptococcus suis adhered to each other in the biofilm and formed a dense three-dimensional structure. The biofilm was treated with antibiotics, bacteriophage SMP and lyase LySMP, respectively. The results showed that the normal dose of antibiotics (20 渭 g / ml) did not destroy the biofilm structure and kill the biofilm bacteria. Bacteriophage SMP could not kill the biofilm bacteria or destroy the biofilm structure effectively, and the lyase LySMP could kill almost all SS2-4 and SS2-H biofilm bacteria within 12 h, and eliminate more than 80% of the biofilm. The study on the biological characteristics and degradation methods of Streptococcus suis biofilm can provide a theoretical basis for further revealing the mechanism of biofilm formation, drug resistance mechanism, and removal of biofilm from Streptococcus suis.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R378
本文编号：2465680
[Abstract]:Streptococcus suis (Streptococcus suis,SS) is an important zoonotic pathogen that causes meningitis septicemia arthritis endocarditis pneumonia and human meningitis in piglets. Streptococcus suis type 2 has the most widespread prevalence and the strongest virulence to pigs, which has caused huge economic losses to pig industry. In public health, it also poses a threat to the life safety of relevant employees. More seriously, when Streptococcus suis forms biofilm, biofilm will provide a protective lifestyle for bacteria, which may greatly improve its resistance and pathogenicity. The biological characteristics of Streptococcus suis biofilm were studied in this paper. It was found that most Streptococcus suis had the ability to form biofilm in varying degrees, among which 10 strains (10 渭 32) had strong biofilm forming ability. It takes about 60 hours to mature the biofilm of Streptococcus suis. Glucose concentration in the culture medium is an important factor influencing the formation of biofilm. Exopolysaccharide is an important part of biofilm. The content of polysaccharide in biofilm is significantly higher than that of P. aeruginosa. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of ampicillin sodium and amoxicillin on the biofilm of Streptococcus suis were 2500 times higher than those of S. suis. Scanning electron microscopy (SEM) showed that Streptococcus suis adhered to each other in the biofilm and formed a dense three-dimensional structure. The biofilm was treated with antibiotics, bacteriophage SMP and lyase LySMP, respectively. The results showed that the normal dose of antibiotics (20 渭 g / ml) did not destroy the biofilm structure and kill the biofilm bacteria. Bacteriophage SMP could not kill the biofilm bacteria or destroy the biofilm structure effectively, and the lyase LySMP could kill almost all SS2-4 and SS2-H biofilm bacteria within 12 h, and eliminate more than 80% of the biofilm. The study on the biological characteristics and degradation methods of Streptococcus suis biofilm can provide a theoretical basis for further revealing the mechanism of biofilm formation, drug resistance mechanism, and removal of biofilm from Streptococcus suis.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R378
【引证文献】
相关期刊论文 前1条
1 张瑞安;刘军;冯书章;;噬菌体裂解酶的研究进展[J];中国生物制品学杂志;2012年05期
相关硕士学位论文 前2条
1 卜倩倩;盐酸小檗碱通过SortaseA和Esp途径影响粪肠球菌生物被膜的初步探讨[D];中南大学;2012年
2 刘静;大环内酯类及β-内酰胺类药物对猪链球菌生物被膜的体外作用研究[D];东北农业大学;2012年
，本文编号：2465680
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