【摘要】：抗生素自發(fā)現(xiàn)以來(lái),因其驚人的抗菌能力,被廣泛用于農(nóng)業(yè)、漁業(yè)、畜牧業(yè)等領(lǐng)域。但是由于其大規(guī)模無(wú)節(jié)制的使用,誘導(dǎo)了抗性基因的產(chǎn)生,引發(fā)了一系列環(huán)境問(wèn)題。為有效解決抗生素濫用而導(dǎo)致的抗性基因問(wèn)題,群體感應(yīng)抑制劑作為最為可能的抗生素替代品被提出。可見(jiàn),抗生素與群體感應(yīng)抑制劑在未來(lái)將不可避免的長(zhǎng)期共存于環(huán)境中。因此,研究抗生素與群體感應(yīng)抑制劑的慢性聯(lián)合毒性,開(kāi)展它們低劑量下是否存在刺激微生物生長(zhǎng)(hormesis效應(yīng))的工作,為相關(guān)生態(tài)環(huán)境風(fēng)險(xiǎn)評(píng)價(jià)甚至醫(yī)學(xué)聯(lián)合用藥提供理論依據(jù),具有重要的科學(xué)意義。本文選取了12種磺胺類(lèi)抗生素及三類(lèi)群體感應(yīng)抑制劑,以費(fèi)氏弧菌為模式生物,分別測(cè)定了其15min急性單一毒性、15min急性混合毒性、24h慢性單一毒性、24h慢性混合毒性及24h慢性單一hormesis、24h慢性混合hormesis現(xiàn)象。通過(guò)化合物理化參數(shù)的計(jì)算、相關(guān)蛋白的同源建模、分子對(duì)接及細(xì)菌體內(nèi)吲哚實(shí)驗(yàn)的測(cè)定,初步探討了磺胺類(lèi)抗生素與群體感應(yīng)抑制劑的急慢性聯(lián)合毒性作用機(jī)制及hormesis現(xiàn)象產(chǎn)生的原因。研究結(jié)果如下:(1)呋喃酮類(lèi)化合物與磺胺類(lèi)抗生素的二元等毒性比下的急性聯(lián)合效應(yīng)表現(xiàn)為協(xié)同與加和,吡咯酮類(lèi)、吡咯類(lèi)化合物與磺胺類(lèi)抗生素的二元等毒性比下的急性聯(lián)合效應(yīng)分別表現(xiàn)為加和與拮抗。群體感應(yīng)抑制劑的最正氫電荷的值的大小可能是其急性聯(lián)合作用機(jī)制不同的原因。(2)三類(lèi)群體感應(yīng)抑制劑與磺胺類(lèi)抗生素對(duì)費(fèi)氏弧菌的慢性聯(lián)合作用都表現(xiàn)為拮抗作用。推測(cè)其原因可能是磺胺類(lèi)抗生素促進(jìn)了細(xì)菌體內(nèi)的Lux R蛋白的表達(dá),而群體感應(yīng)抑制劑與細(xì)菌產(chǎn)生的信號(hào)分子競(jìng)爭(zhēng)結(jié)合Lux R蛋白,導(dǎo)致了慢性的拮抗。(3)12種磺胺在低劑量時(shí)會(huì)刺激費(fèi)氏弧菌光值增大,產(chǎn)生hormesis效應(yīng)。原因是其促進(jìn)了細(xì)菌體內(nèi)Lux R蛋白的表達(dá),而Lux R蛋白是細(xì)菌發(fā)光的主要調(diào)控蛋白。通過(guò)細(xì)菌生長(zhǎng)過(guò)程中吲哚的測(cè)定,推斷吲哚并不是導(dǎo)致費(fèi)氏弧菌Lux R蛋白表達(dá)量增加的物質(zhì),因此,hormesis現(xiàn)象產(chǎn)生的機(jī)制有待進(jìn)一步的研究。(4)本研究具有hormesis效應(yīng)的兩種化合物混合后hormesis效應(yīng)依然明顯。用hormesis效應(yīng)曲線與Y=0的直線所圍成的閉合區(qū)間面積來(lái)評(píng)價(jià)hormesis效應(yīng)。用Brain-Cousens模型將hormesis劑量-效應(yīng)曲線擬合并計(jì)算閉合區(qū)間面積,建立單一hormesis面積與混合hormesis面積的相關(guān)關(guān)系方程,所建方程R2均大于0.64,說(shuō)明該方程具有統(tǒng)計(jì)學(xué)意義,可用于混合hormesis效應(yīng)的預(yù)測(cè)。
[Abstract]:Since its discovery, antibiotics have been widely used in agriculture, fishery, animal husbandry and so on. However, because of its large-scale and uncontrolled use, resistance genes are induced and a series of environmental problems are caused. In order to effectively solve the problem of resistance gene caused by antibiotic abuse, population sensing inhibitors have been proposed as the most likely substitute for antibiotics. It can be seen that antibiotics and colony-sensing inhibitors will inevitably coexist in the environment for a long time in the future. Therefore, to study the chronic joint toxicity of antibiotics and colony sensing inhibitors, and to study whether there is hormesis effect in low dose of antibiotics or not, to provide theoretical basis for ecological risk assessment and even medical combination drug use. It has important scientific significance. In this paper, 12 kinds of sulfonamides antibiotics and three kinds of population sensing inhibitors were selected, and Vibrio fernivalis was used as the model organism. The chronic mixed toxicity of 15min for 15 minutes and chronic mixed toxicity for 24 h and chronic mixed hormesis for 24 h were determined respectively. Through the calculation of physical and chemical parameters of compounds, the homology modeling of related proteins, the molecular docking and the determination of indole in bacteria, The mechanism of acute and chronic joint toxicity of sulfanilamide antibiotics and colony sensing inhibitors and the causes of hormesis phenomenon were discussed. The results are as follows: (1) the acute combined effects of furanone compounds and sulfanilamide antibiotics are synergistic and additive, pyrrolidone, pyrrolidone, The acute combined effects of pyrrole compounds and sulfanilamide antibiotics were additive and antagonistic respectively. The magnitude of the most positive hydrogen charge of the population sensing inhibitors may be the reason for the different mechanisms of their acute combination. (2) the chronic combination of three kinds of group induction inhibitors and sulfonamides against Vibrio ferrovirii showed antagonistic effects. It may be that sulfonamides promote the expression of Lux R protein in bacteria, while colony sensing inhibitors compete with the signal molecules produced by bacteria to bind Lux R protein. (3) 12 sulfonamides can stimulate the light value of Vibrio flexneri to increase at low dose and produce hormesis effect. The reason is that it promotes the expression of Lux R protein in bacteria, and Lux R protein is the main regulation protein of bacterial luminescence. Based on the determination of indole during bacterial growth, it was inferred that indole was not the substance that led to the increase of Lux R protein expression in Vibrio ferriformis. Therefore, the mechanism of hormesis needs further study. (4) the hormesis effect of the two compounds with hormesis effect is still obvious. The hormesis effect is evaluated by using the closed interval area between the hormesis effect curve and the straight line of Y _ (0). The hormesis dose-effect curve is combined with Brain-Cousens model to calculate the closed interval area, and the correlation equation between the single hormesis area and the mixed hormesis area is established. The equation R2 is larger than 0.64, which shows that the equation has statistical significance. It can be used to predict mixed hormesis effect.
【學(xué)位授予單位】：上海海洋大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：X171.5

【參考文獻(xiàn)】

相關(guān)期刊論文 前3條

1 高常安;張愛(ài)茜;藺遠(yuǎn);尹大強(qiáng);王連生;;酚類(lèi)化合物非單調(diào)劑量-效應(yīng)毒理學(xué)機(jī)制的QSAR研究[J];科學(xué)通報(bào);2009年02期

2 程古月;郝海紅;戴夢(mèng)紅;劉振利;袁宗輝;;病原菌的群體感應(yīng)及其抑制劑的研究進(jìn)展[J];科學(xué)通報(bào);2012年21期

3 張蕾;;青霉素的發(fā)展[J];河北企業(yè);2013年06期

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本文編號(hào)：2220978