本文選題：銅綠假單胞菌　切入點(diǎn)：生物膜　出處：《青島大學(xué)》2009年碩士論文　論文類型：學(xué)位論文

【摘要】： 目的:研究銅綠假單胞菌(PA)在抗生素誘導(dǎo)狀態(tài)下,產(chǎn)酶基因AmpC在浮游和生物膜狀態(tài)下的表達(dá)差異,群體感應(yīng)(QS)系統(tǒng)對產(chǎn)酶基因AmpC表達(dá)的影響。 方法:改良的平板法建立PA生物膜模型,抗生素誘導(dǎo)浮游菌和生物被膜菌AmpC基因表達(dá),采用實(shí)時(shí)熒光定量PCR方法測定PAO1、PAO1加用QS抑制劑(呋喃酮C-30)及QS系統(tǒng)缺陷菌株的AmpC基因表達(dá)水平。 結(jié)果:抗生素誘導(dǎo)前,PAO1浮游菌和生物膜菌的AmpC基因表達(dá)均較低,誘導(dǎo)后AmpC基因表達(dá)均明顯上調(diào)。運(yùn)用產(chǎn)最大AmpC酶活性的濃度的抗生素誘導(dǎo)后,亞胺培南和頭孢他定誘導(dǎo)的生物膜菌的AmpC基因表達(dá)量均高于其誘導(dǎo)的浮游菌。在浮游和生物膜狀態(tài)下,亞胺培南誘導(dǎo)PAO1的AmpC基因表達(dá)量均高于頭孢他定。PAO1在抗生素誘導(dǎo)同時(shí)加用呋喃酮C-30后,浮游菌和生物被膜菌的AmpC基因表達(dá)水平均較不加用呋喃酮C-30下調(diào),生物被膜菌下調(diào)的程度大于浮游菌,兩者差別有統(tǒng)計(jì)學(xué)意義(P＜0.05)。在浮游和生物膜狀態(tài)運(yùn)用抗生素誘導(dǎo),QS系統(tǒng)缺陷菌株P(guān)AO-MW1、PAO-JP1的AmpC基因表達(dá)水平均較PAO1低。 結(jié)論:生物膜PA較浮游菌更易被誘導(dǎo)產(chǎn)生AmpC酶,亞胺培南的誘導(dǎo)能力高于頭孢他定。PA的QS系統(tǒng)直接或間接調(diào)控AmpC基因的誘導(dǎo)表達(dá),不同狀態(tài)下QS系統(tǒng)發(fā)揮調(diào)控作用的水平不同可能是生物被膜菌較浮游菌易誘導(dǎo)產(chǎn)酶原因之一。
[Abstract]:Aim: to study the difference of AmpC expression between plankton and biofilm induced by Pseudomonas aeruginosa (PAA) and the effect of population sensing system on the expression of AmpC. Methods: PA biofilm model was established by modified plate method. AmpC gene expression was induced by antibiotics in phytoplankton bacteria and biofilm bacteria. The expression of AmpC gene in PAO1-PAO1 + QS inhibitor (furanone C-30) and QS system deficient strains was determined by real-time fluorescence quantitative PCR. Results: the AmpC gene expression of PAO1 and biofilm bacteria was lower and the expression of AmpC gene was up-regulated after antibiotic induction. The expression of AmpC gene in biofilm bacteria induced by imipenem and ceftazidine was higher than that in phytoplankton induced by imipenem and ceftazidine. The expression of AmpC gene in PAO1 induced by imipenem was higher than that in ceftazidine. PAO1. The expression level of AmpC gene in phytoplankton and biofilm bacteria was lower than that in non-treated furanone C-30. The down-regulation degree of biofilm bacteria was higher than that of phytoplankton, and the difference was statistically significant (P < 0.05). The AmpC gene expression level of PAO-MW1 PAO-JP1 was lower than that of PAO1 in phytoplankton and biofilm status. Conclusion: the biofilm PA is more easily induced to produce AmpC than that of phytoplankton, and imipenem can directly or indirectly regulate the expression of AmpC gene in the QS system of cefatadine. Different levels of QS system regulation may be one of the reasons why biofilm bacteria can induce enzyme production more easily than phytoplankton bacteria.
【學(xué)位授予單位】：青島大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2009
【分類號】：R378

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