鲍曼不动杆菌耐药分析及其intl1在生物被膜中作用机制探讨

发布时间：2018-01-10 12:15

本文关键词：鲍曼不动杆菌耐药分析及其intl1在生物被膜中作用机制探讨　出处：《中南大学》2008年硕士论文　论文类型：学位论文

【摘要】： 目的:了解长沙地区鲍曼不动杆菌的耐药现状,为临床治疗鲍曼不动杆菌感染提供指导;探讨鲍曼不动杆菌Ⅰ类整合子的分布以及Ⅰ类整合酶基因在生物被膜与液态培养下的表达,为研究鲍曼不动杆菌整合子在其生物被膜中的耐药机制奠定基础。方法:①收集鲍曼不动杆菌临床菌株并进行纸片扩散法药敏实验。②对收集的菌株进行基因扩增筛选出携带Ⅰ类整合酶的菌株,并检测分析Ⅰ类整合子系统插入相关耐药基因盒情况。③培养观察形成生物被膜的菌株并对生物被膜形成能力进行分析。④通过RT-PCR半定量方法分析Ⅰ类整合酶基因在生物被膜生长状态以及普通液相培养状态下的表达情况。结果:①Ⅰ类整合子相关基因盒阳性菌株对8种抗菌药物耐药率依次为氨苄西林/舒巴坦56%、亚胺培南33%、美洛西林100%、妥布霉素100%、四环素100%、复方新诺明100%、环丙沙星100%和头胞他啶100%,并且Ⅰ类整合子相关基因盒阳性菌株对环丙沙星等7种抗生素耐药率均显著高于Ⅰ类整合子相关基因盒阴性菌株(经X~2检验,差异有统计学意义,P＜0.05)。②64株临床菌株携带Ⅰ类整合酶的有46株,相关基因盒阳性的Ⅰ类整合子为9株。9株Ⅰ类整合子相关基因盒的扩增产物集中在1500bp至3000bp之间。③46株鲍曼不动杆菌中有42株能够形成生物被膜。④生物被膜状态下的鲍曼不动杆菌Ⅰ类整合酶基因表达增高。在普通液态培养组一类整合酶基因表达量为0.973±0.754,而在生物被膜状态组一类整合酶基因表达量则为2.545±0.674。结论:临床鲍曼不动杆菌的耐药情况严峻。Ⅰ类整合子分布广泛,并且Ⅰ类整合子基因盒阳性菌株耐药率明显高于Ⅰ类整合子基因盒阴性菌株。鲍曼不动杆菌大多具有较强的生物被膜形成能力。Ⅰ类整合酶基因在不同生长状态下均可表达,但在生物被膜生长状态下的表达增高。
[Abstract]:Objective: to understand the Changsha area Bauman real resistance of Bacillus, for the clinical treatment of Bauman still provide guidance on Bauman infection; Acinetobacter integron integrase gene and distribution in biological is the expression of membrane and liquid culture, for the study of Bauman Acinetobacter resistance integron was to lay the foundation in the film in its biological mechanism.
Methods: the collection of Bauman real clinical strains bacillus and disk diffusion susceptibility test. The strains were collected for gene amplification were screened with integrase strains, detection and analysis of class I integron insertion related resistance gene cassettes. To observe the formation of biofilm strains and the biological is film forming ability were analyzed. The cultured through the semi quantitative RT-PCR analysis method of integrase gene in the biofilm growth state and liquid state culture expression.
Results: 1 integron gene cassettes positive strains followed by ampicillin / sulbactam 56% to 8 kinds of antimicrobial drug resistance rate of imipenem 33%, mezlocillin 100%, 100% tobramycin, tetracycline 100%, cotrimoxazole 100%, ciprofloxacin 100% and ceftazidime 100%, and integron related gene cassette positive strains to ciprofloxacin and other 7 kinds of antibiotics were significantly higher than that of integron gene cassettes negative strains (by X~2 test, the difference was statistically significant, P < 0.05). The 64 strains carrying class 1 integrase are 46 strains, gene cassettes in integrons is positive PCR products of 9.9 strains of integron gene cassettes concentrated between 1500bp to 3000bp. The 46 strains of Bauman Acinetobacter in 42 strains could form biofilm. The biofilm state of the Bauman Acinetobacter integrase gene expression The expression of integrase gene is 0.973 + 0.754 in the ordinary liquid culture group, and the expression of an integrase gene is 2.545 + 0.674. in the biofilm state group.
Conclusion: the clinical Bauman real drug resistance of Bacillus grim. Integrons are widely distributed, and integron gene cassette positive strain resistance was significantly higher than that of integron gene cassette negative strains. Bauman Acinetobacter has strong biofilm forming ability. The class 1 integrase gene can be expressed in different the growth state, but in the biofilm growth under the condition of higher expression.

【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R378

【参考文献】