本文選題：大腸菌群　切入點：顯色培養(yǎng)基　出處：《鄭州大學》2012年碩士論文　論文類型：學位論文

【摘要】：背景及目的大腸菌群作為評價食品衛(wèi)生質(zhì)量的重要指標之一,已被廣泛的應(yīng)用于食品衛(wèi)生領(lǐng)域,它不僅能反映被檢測物是否被污染及受污染程度,而且在一定程度上也能反映出食品在生產(chǎn)、加工、運輸及儲存等過程中的衛(wèi)生狀況,其檢出具有重要的微生物學意義。我國的食品衛(wèi)生微生物學檢驗國家標準(GB4789)系列中,大腸菌群的測定常常作為必檢項目。目前,對于大腸菌群的檢測有很多類方法,最為廣泛采用的仍是國標三步法檢測,此法具有準確、可靠等優(yōu)點,但檢測周期長,操作繁瑣,耗時費力,且不能滿足快速檢測的需求,所以尋求快速、準確、并且操作簡單的大腸菌群檢測方法,是食品安全部門亟待解決的問題。上世紀末法國科瑪嘉公司發(fā)明的顯色培養(yǎng)基技術(shù)從一定程度上解決了關(guān)于微生物常規(guī)檢測中出現(xiàn)的難題,目前國內(nèi)使用最多的是進口的大腸菌群顯色培養(yǎng)基產(chǎn)品,價格昂貴,成本高,而且配制過程中對溫度、實驗環(huán)境等外在因素要求比較嚴格,因此不適用于現(xiàn)場檢測工作。為了滿足國內(nèi)食品檢驗對大腸菌群快速檢測培養(yǎng)基的實際需求,本課題利用微生物所具有的特異性酶及其相對應(yīng)的顯色底物研制出一種能快速檢測大腸菌群的鑒別顯色培養(yǎng)基,并對其實際應(yīng)用價值進行評價,以期獲得快速、準確、敏感度高、特異性強并且適用于實時監(jiān)測工作的經(jīng)濟型檢測產(chǎn)品。方法以初步篩選的普通營養(yǎng)瓊脂平板為基礎(chǔ),添加促大腸菌群生長和抑制雜菌生長等物質(zhì),如瓊脂、蛋白胨、酵母粉、乳糖、氯化鈉、月桂基硫酸鈉、磷酸二氫鉀、磷酸氫二鉀等,同時設(shè)計相應(yīng)的酶顯色底物及添加方式,通過兩組正交優(yōu)化實驗,確定其最終配方,形成大腸菌群顯色培養(yǎng)基平板(Coliform Chromogenic Medium)以下簡稱為CCM。觀察培養(yǎng)基的顯色效果,以大腸菌群標準菌株及其他食源性致病菌標準菌株、100份實際食物樣品為對象；準確可靠的國標檢測法為參考,從檢測時間及成本、平板效率、特異性、敏感度和準確性等方面綜合評價該顯色培養(yǎng)基的性能。結(jié)果①該培養(yǎng)基在37℃培養(yǎng)18h就可直接觀察菌落顏色來鑒別大腸菌群菌屬,顯色清晰,結(jié)果易于觀察,并且檢測成本明顯低于現(xiàn)有的大腸菌群國標檢測法。②該顯色培養(yǎng)基與國標法中采用的鑒別培養(yǎng)基結(jié)晶紫中性紅膽鹽瓊脂(VRBA)的出菌率即平板效率對比,差異無顯著性(t=0.578,P0.05)。③該顯色培養(yǎng)基的特異性和敏感度分別能達到100%和90%,證實具有較高的敏感度和特異性。④用實際食物樣品進行評價,該方法與國標法的檢測準確性比較,差異無顯著性(Z2=0.125,P0.05)。結(jié)論自主研制的大腸菌群快速檢測顯色培養(yǎng)基具有快速、準確、靈敏度和特異性高等優(yōu)點,可用于實際食品衛(wèi)生微生物的初篩工作。
[Abstract]:Background and objective coliform bacteria, as one of the important indicators for evaluating food hygiene quality, have been widely used in the field of food hygiene, which can not only reflect whether the detected substances are contaminated or not, but also the degree of contamination. To a certain extent, it can also reflect the hygienic status of food in the process of production, processing, transportation and storage, and its detection has important microbiological significance. At present, there are many kinds of methods for coliform group detection, and the most widely used method is the national standard three-step method. This method has the advantages of accuracy and reliability, but the detection period is long and the operation is tedious. Time-consuming and difficult to meet the need for rapid detection, so seek fast, accurate, and simple operation of coliform detection methods, It is an urgent problem for food security department. In 0th century, Colour medium technology invented by Comarga Company of France solved the problem of microorganism routine detection to some extent. At present, the imported coliform coliform coliform medium products are used most in our country. They are expensive and expensive, and the external factors such as temperature and experimental environment are strictly required in the preparation process. Therefore, it is not suitable for field testing. In order to meet the actual demand of domestic food inspection for rapid detection of coliform bacteria, In this paper, the specific enzyme of microorganism and its corresponding chromogenic substrate were used to develop a medium for rapid detection of coliform bacteria, and its practical application value was evaluated in order to obtain fast and accurate coliform. Methods based on the preliminary screening of common nutrient Agar plate, we added some substances, such as promoting coliform group growth and inhibiting the growth of miscellaneous bacteria, such as Agar, peptone, etc. Yeast powder, lactose, sodium chloride, sodium lauryl sulfate, potassium dihydrogen phosphate, potassium hydrogen phosphate, and so on. At the same time, the corresponding enzyme chromogenic substrate and adding method were designed, and the final formula was determined by two groups of orthogonal optimization experiments. The formation of coliform Chromogenic medium was referred to as CCM.To observe the color effect of the medium, 100 samples of food samples from coliform standard strains and other standard foodborne pathogenic bacteria strains were taken as objects. Accurate and reliable national standard detection method for reference, from detection time and cost, plate efficiency, specificity, Results 1 the color of coliform bacteria could be directly observed at 37 鈩，

本文編號：1581562