采用ATP生物发光法分析6株常见细菌ATP含量差异

以ATP生物发光法为基础,辅以国标平板计数法,分析和测定了大肠埃希氏菌、枯草芽孢杆菌、蜡状芽孢杆菌、乳酸链球菌、乳酸片球菌等6株常见细菌中ATP含量的差异。结果显示:当单位体积菌悬液的ATP荧光值相同时,6株细菌菌落总数无明显差异;当菌悬液的菌落总数相同时,6株细菌的单位体积菌悬液ATP含量无明显差异。研究结果同时说明ATP生物发光法能够定量测定常见区域中的细菌总数。     

ATP法测定奶中的细菌含量

为了评价ATP法在UHT奶中菌藩总数和商业无菌检测的实用性,本研究通过检测UHT乳中ATP本身的含量,以及微生物平板计数法和商业菌落总数Petfifilm俐测试片法对样品进行菌落总数和商业无菌检测,建立样品中ATP含量与菌落总数的对应关系。结果表明,不同品类UHT牛奶中ATP法结果与菌落总数Petrifilm^TM测试片法和国标平板计数法结果的相关性强,复现性好。由此可知,ATP法可以作为一种快速检测UHT奶中菌落总数和商业无菌的方法。     

平板计数法与纸片法检测食品微生物菌落总数的比较分析

食品污染的微生物主要是细菌,通过对食品微生物菌落总数进行检测,能够掌握食品受污染程度。而平板计数法与纸片法均能够对食品微生物菌落总数进行检测,对二者进行比较分析,能够为菌落计数标准方法的调整提供思路。一、实验方法比较准备平板计数琼脂培养基和菌落总数测试片,并准备饼干、蛋糕以及两份质控样品。具体实验如下:1.平板计数法。(1)培养基的配制。     

CTAB提取ATP的生物荧光法快速检测细菌总数准确性研究

为降低ATP生物荧光法检测费用,本研究采用十六烷基三甲基溴化铵(CTAB)为细菌细胞ATP的提取剂,β-环糊精为中和剂,优化不同食品体系中细菌ATP的提取方法,同时检验CTAB提取ATP的生物荧光法快速检测细菌总数的准确性。结果表明:大肠杆菌、金黄色葡萄球菌、乳酸菌和枯草芽孢杆菌细胞采用CTAB提取出的细菌ATP的发光强度与细菌总数的线性相关性良好,相关系数均在0.92以上。对代表性的果汁、面、肉和奶制品经CTAB处理提取出细菌ATP后,对于细菌总数在103~107 CFU/mL的产品,根据ATP的荧光强度,能准确的判断出细菌总数,且生物荧光法与平板计数法两者检测结果的相关系数达到0.9895。但在原料肉的测定时,提取出的ATP的荧光强度与其细菌总数之间的相关性较差,为提高检测准确性,需要预先采用相关去除体细胞ATP干扰的配套试剂进行处理。     

Soleris检测技术在焙烤食品微生物检测中的应用研究

应用Soleris检测技术,以实现对焙烤食品(面包)中的菌落总数和大肠菌群的快速检测,并验证其检测结果的可靠性。得到焙烤食品中菌落总数的标准曲线为lg cfu/g=—0.44DT+9.3595,R~2=0.9833;大肠菌群的标准曲线为lg cfu/g—0.7422DT+8.6369,R~2=0.9803。用平板计数法对标准曲线进行验证,结果显示,2种方法对菌落总数(大肠菌群)的测定结果间无显著差异,结果对数值的绝对差值低于0.5,具有较好的一致性;对Soleris法测定菌落总数和大肠菌群的重复性进行验证,RSD分别为1.72%～3.87%、3.27%～4.34%。相较平板计数法,Soleris法可缩短一半以上的检测时间,大幅提高检测效率。文章建立的焙烤食品中菌落总数和大肠菌群的Soleris快速检测方法,可为焙烤食品生产企业在微生物快检方法的选择上提供参考。     

食品微生物检验菌落总数测定方法的效果分析

目的:分析研究食品微生物检验菌落总数测定方法的测定效果。方法:选取本疾控中心接收的220份食品样品,对其采取3种方法进行检测,包括平板菌落计数法、TCT培养基法以及菌落总数测定法,对其检验结果进行对比分析。结果:平板菌落计数法的不合格率为9.1%,菌落总数测定法的不合格率为8.2%,TCT培养基法的不合格率为10%,3种检测方法结果之间的差异不具有统计学意义(P0.05)。结论:食品微生物检验采取平板菌落计数法、TCT培养基法以及菌落总数测定法这3种方法均可以取得相对比较高的准确性,可以按照具体情况选择适宜的检验方法。     

倾注平板计数法和纸片法测试菌落总数的比较研究

<正> 菌落总数主要是作为判定食品被污染程度的标记,也可以应用这一方法观察食品中细菌的性质以及细菌在食品中繁殖的动态,以便对被检样品进行卫生学评价时提供科学依据。该测试项目是2002年亚太实验室认可合作组织的食品微生物学能力验证计划(编号T030)的一个考核项目。参试实验室按使用的培养基不同菌落总数的测试方法分两种,分别为倾注平板计数法和再水化干燥纸片(3M     

基于测试片法与平板计数法对不同类型食品中菌落总数结果的比较分析

目的比较菌落测试片法与平板计数法在不同类型食品中菌落总数测定结果的差异。方法在市面上随机抽取生肉制品、鲜奶制品、豆制品、粮食制品、冷冻饮品、坚果籽实、即食果蔬制品共112批,同时按菌落测试片法和平板计数法进行菌落总数测定,并对计数结果进行统计学分析。结果菌落测试片法与平板计数法的测定结果对数值差值的平均值|d log|= 0.06(<0.5),配对t检验P=0.860(>0.05)。结论菌落测试片法与平板计数法对上述7种类型的食品菌落总数测定结果无显著性差异,菌落测试片法可用于上述食品的菌落总数测定。     

应用TTC显色测定食品中菌落总数

应用ＴＴＣ显色测定食品中菌落总数李奇英张华（天津市乳品食品监测中心，天津３００３８１）１前言在食品卫生微生物检验中一般都要进行菌落总数的测定。菌落总数测定是用来判定食品被细菌污染的程度。目前国内外对菌落总数的测定基本上都采用平板计数法。在我国对食品中...     

ATP生物发光法快速检测电子烟雾化液菌落总数

利用三磷酸腺苷(ATP)生物发光法建立快速检测电子烟雾化液微生物菌落总数的方法并进行优化,与国家标准微生物检测方法进行对比分析。结果表明:(1)ATP荧光检测仪的最优检测温度为25℃,反应时间为30s,ATP检出限为2.36×10~(-12) mol/L,RSD为3.5%~8.2%,加标回收率为97%~108%;(2)滤膜过滤富集检测可实现低活菌数样品的检测,混合纤维素酯滤膜的富集检测效果优于聚碳酸酯滤膜和醋酸纤维滤膜,富集后检测ATP生物荧光的相对光度值与富集前活菌总数具有良好的对数线性相关关系(r~20.96);(3)采用ATP检测方法估算的活菌总数结果与平板计数检测结果没有显著性差异(P0.05),对电子烟雾化液的卫生情况评价结果一致。ATP生物发光检测方法可快速计算电子烟雾化液菌落总数,对于电子烟安全卫生风险评估具有建设意义。     

生物发光快速测定生乳菌落总数的方法

为消除利用ATP生物发光法测定生乳菌落总数时非细菌ATP对测定结果的干扰,建立了一种样品前处理方法。利用ATP生物发光法对经过前处理的生乳样品进行检测,结果表明,生乳菌落总数对数值与生乳细菌ATP发光对数值呈现较好的线性关系(R2=0.982),相关程度为显著相关(P<0.01),说明该前处理方法能够有效排除非细菌ATP的干扰,有利于提高ATP生物发光法定量测定生乳菌落总数准确性。     

ATP生物发光法评价餐饮具的微生物污染研究

目的对ATP生物发光法与平板计数法在评价餐饮具微生物污染的检出限及检出率进行评价,并对2种方法的相关性进行研究。方法应用3家国内公司生产的ATP生物发光检测仪,分别对不同浓度的ATP标准溶液检测并绘制标准曲线;以不同浓度的大肠杆菌、金黄色葡萄球菌菌液及人工接种大肠杆菌的餐饮具作为被检品,分别应用ATP生物发光法和平板计数法进行检测,绘制ATP生物发光法对大肠杆菌、金黄色葡萄球菌检测的标准曲线,并对2种检测方法在人工污染餐饮具检测的相关性绘制曲线。结果 3家公司的ATP生物发光检测仪对ATP标准溶液、大肠杆菌和金黄色葡萄球菌的检出限差异较大;但在某一检测范围内,3家公司ATP生物发光检测仪的检测RLU值与ATP标准溶液、大肠杆菌和金黄色葡萄球菌量均有良好的线性相关性。3家公司ATP生物发光检测仪对人工接种大肠杆菌餐饮具的检测显示,ATP生物发光法与平板计数法有良好的线性相关性。结论3家公司的ATP生物发光法对ATP、大肠杆菌和金黄色葡萄球菌的检出限存在不同检测仪的仪器误差,且差异较大,目前,ATP生物发光法不能替代传统的平板计数法来评价餐饮具的微生物污染状况。     

ATP生物发光检测技术的建立及应用可行性分析

建立了测定食品中细菌总数的ATP生物发光检测技术,考察了各种理化因素对生物发光反应的影响。反应体系最优化条件:Ln浓度为70mg/L,FL浓度为50mg/L,Mg2+浓度为0.25mmoL/L,pH为7.2,最适温度为23℃。在10-10～10-15mol/mL范围内,ATP浓度与生物发光强度之间有较好的线性关系,相关系数R2=0.978。方法检出限为10-15mol/mL,批内变异和批间变异分别小于7%和8%。将建立好的ATP生物发光反应体系应用于食品样品中细菌总数的检测,加标回收率范围为82.2%～112.4%,检测结果与平板计数结果相关性良好。因此,建立的ATP生物发光检测技术用于检测食品中细菌总数是可行的。     

Study on rapid quantitative detection of total bacterial counts by the ATP‐bioluminescence and application in probiotic products

The objective of this study was to develop a rapid quantitative detection method by triphosphate (ATP)‐bioluminescence and determine the feasibility to assay total bacterial counts (TBC) in probiotic products. A useful pretreatment technique to eliminate the interference to the ATP‐bioluminescence method was developed, resulting in a 10–100‐fold improvement in the rapid quantitative detection method by ATP‐bioluminescence. The TBC obtained by the ATP‐bioluminescence rapid detection method was tested against the direct microscopic count method or the plate count method and validated on three ATP Assay Systems. The results generated by the ATP methods and the plate count method were comparable to each other when the interference due to non‐microbial cell ATP and matter such as pigment were removed. This study reports the optimisation of an ATP‐bioluminescence assay using a pretreatment technique to eliminate interference in order to quickly determine the viable counts of bacteria in solid and liquid probiotic products.     

Comparison of a rapid ATP bioluminescence assay and standard plate count methods for assessing microbial contamination of consumers' refrigerators

The feasibility of using an ATP bioluminescence assay for assessing microbial contamination of home refrigerators was evaluated and compared with the standard culture methods. Samples of refrigerator surfaces were collected from 123 households by swabbing an area of 100 cm2 on three locations in the refrigerator with premoisturized sterile swabs. Microbial contaminations were determined by aerobic plate count (APC; incubated at 35 degrees C for 48 h) and psychrotrophic plate count (PPC; incubated at 7 degrees C for 10 days) on plate count agar. The results were compared to the readings from the microbial ATP (mATP) bioluminescence assay. The correlation coefficient (r) between mATP and PPC (r = 0.851) was slightly higher than that between mATP and APC (r = 0.823). Our results indicated a potential discrepancy in the population of mesophilic and psychrotrophic bacteria in the refrigerator samples. Nevertheless, mATP appeared to be a reliable indication of the average of APC and PPC (r = 0.895). The mATP bioluminescence assay would provide a rapid and convenient test for researchers in field studies to assess microbial contamination in refrigerators.     

Bioluminescence ATP assay for estimating total plate counts of surface microflora of whole cantaloupe and determining efficacy of washing treatments

The surface microflora of cantaloupes were estimated using a bioluminescence ATP assay, and results were compared to plate count data. Cantaloupes were treated as follows: (i) water washed, or (ii) washed in solutions of sodium hypochlorite (1,000 mg/liter) or hydrogen peroxide (5%) for 5 min. Bioluminescence ATP assay results showed differences in ATP level/cm2 of cantaloupes dipped in chlorine or hydrogen peroxide solution; ATP levels in these washed samples were lower than in controls due to antimicrobial action of the treatments on the cantaloupe surface. Linear correlations were found between the bioluminescence ATP assay and aerobic plate counts of unwashed cantaloupe (r2 = 0.995) and those washed with water (r2 = 0.990) determined before storage. Lower correlations between the bioluminescence ATP assay and the aerobic plate counts were observed on cantaloupes stored for 120 h at 20 degrees C (r2 = 0.751) than at 4 degrees C (r2 = 0.980) without washing treatment. Lower correlation at 20 degrees C may be the result of clusters or growth that occurred in chains. ATP levels of washed cantaloupes correlated well with bacterial plate counts (r2 = 0.999). A reliable minimum detectable threshold using the bioluminescence ATP assay was established at 3 log10 fg/cm2 corresponding to 4 log10 CFU/cm2. Bioluminescence ATP assay is not recommended for washed samples where the microbial load is near or below the threshold. Therefore, the bioluminescence ATP assay will be recommended for quick estimation of total microbial load on cantaloupe surfaces where the population is expected to exceed this threshold. The assay can save the industry time by eliminating the required incubation required by the conventional methods.     

高校周边速食品中病原微生物的检测与评价

由致病微生物引起的食源性疾病,已成为国内主要的食品安全问题之一。为了解天津某高校周边市场即食食品的微生物污染状况,本课题采取随机抽样方法采集天津某高校周边小吃街等场所的主食类、卤制品类、小吃类、凉拌菜类、糕点类、沙拉寿司水果、饮品类等7类别共计50件食品,根据GB/T4789和国家卫生标准,对7类食品中的菌落总数和大肠菌群及主要致病性微生物,包括金黄色葡萄球菌、沙门氏菌、志贺氏菌等进行全程调查与评价。调查结果显示,大肠菌群,金黄色葡萄球菌和沙门氏菌合格率较低,分别是74.98%,62.17%和51.72%。在各类食品中,合格率分别是饮品(75%)>糕点(66.67%)>小吃类(57.89%)>主食类(56.25%)>沙拉寿司(50%)>卤制品(25%)>凉拌菜(0%),在7类食品中,除了饮品以外,都检测出不同程度的致病菌微生物,其中以卤制熟食品和凉拌菜类的合格率最低,分别是25%和0%。主食类、卤制品、小吃类、凉拌菜类3种致病菌均有检出,糕点类只检出沙门氏菌,沙拉寿司水果检出金黄色葡萄球菌和沙门氏菌。研究结果显示,高校周边市场即食食品微生物污染情况严重,致病菌检出率较高,相关部门应该加强对学生的食品安全教育和周边市场的卫生监督,防止食源性疾病发生。     

Rapid Prediction of Maple Syrup Grade and Sensory Quality by Estimation of Microbial Quality of Maple Sap Using ATP Bioluminescence

ABSTRACT: ATP bioluminescence was evaluated as a method for assessing the level of microbial contamination in sap and predicting maple syrup characteristics. This approach provided results that were strongly correlated with the standard plate count and took less time than the modified resazurin technique. ATP bioluminescence measurement of sap proved to be reliable for predicting physicochemical and sensory characteristics as indicated by the color and flavor of maple syrup. Most of the syrups made from saps with higher ATP bioluminescence values were darker in color and presented off-flavors. Based on these results, ATP bioluminescence could be used to improve sanitary practices associated with collecting and storing maple sap.     

High-throughput detection of spore contamination in food packages and food powders using tiered approach of ATP bioluminescence and real-time PCR

A rapid and quantitative method for detection of Bacillus spores in food/non-alcoholic beverage packages and food powders has been developed using filtration-based ATP bioluminescence and real-time PCR, targeting the sporulation gene (spo0A). In combination with heat activation, the presence and amount of viable bacterial spores (i.e., Bacillus amyloliquefaciens, Bacillus licheniformis, and Bacillus thuringiensis) was determined within 20 min through ATP signal amplifications. The detection limits of heat activation-ATP bioluminescence assay for B. amyloliquefaciens and B. licheniformis spores on food packages were 1.4 × 10² and 1.0 × 10³ CFU/cm², respectively. In contaminated food powders, B. thuringiensis spores could be detected by the ATP assay within the range of 7.9 × 10⁰ to 3.2 × 10⁴ CFU/mg powder while the PCR detection limit was 614 CFU/mg. Linear relationships between luminescent signal (RLU/mg) and plate count (CFU/mg) were found. The same sample after heat activation-ATP assay could be directly used for real-time PCR as a streamlined detection to confirm the identity of Bacillus spores in food packages and food powders even though some bacterial DNA loss was observed. This tiered approach, filtration-based one-tube ATP luminescence method as a rapid, viable screening and using real-time PCR as confirmation, could serve as a high-throughput tool for the detection of Bacillus spores in the food and beverage industry.     

A sampling regime based on an ATP bioluminescence assay to assess the quality of poultry carcasses at critical control points during processing

The implementation of HACCP (Hazard Analysis Critical Control Point) programs are proposed as a method of reducing foodborne illness. However, good statistical planning and appropriate measurement techniques are required to verify the control of the microbial hazards in food processing systems. In this study, a latin square design was used to sample carcasses taken throughout a poultry processing line for microbial contamination. Samples were taken during the processing of several flocks (n=16) over four separate days. Carcasses were sampled by swabbing and levels of contamination determined by both plate count and an ATP (adenosine triphosphate) bioluminescence assay. The results showed that the design was able to significantly interpret (p≤0.001) the data obtained from both assays. In both cases, carcass contamination significantly improved (p≤0.001) after immersion in the pre-chill and chilling tanks. In addition, significant differences (p≤0.05) were found between flocks and between processing days. The study indicated that an appropriate experimental design and application of microbiologically-based systems can be useful for validation of HACCP programs.