2015年江苏省网店自制食品中食源性致病菌的 监测分析

目的 监测江苏省网店自制食品食源性致病菌的污染状况。了解金黄色葡萄球菌产毒及耐药特点。方法 GB4789《食品安全国家标准 食品微生物学检验》方法,选取无锡、常州、盐城等3个监测点,采集我省范围内的网店自制食品共214份,进行沙门氏菌、金黄色葡萄球菌、单增李斯特菌的检验。对分离得到的金黄色葡萄球菌进行葡萄球菌肠毒素检验和药物敏感性试验。结果 共检出食源性致病菌13株,总检出率为6.1%。其中金黄色葡萄球菌9株单增李斯特菌4株,未检出沙门菌。3份样品金黄色葡萄球菌污染超出国家食品限量值。9株金黄色葡萄球菌中6株产生葡萄球菌肠毒素。结论 江苏地区网店自制食品存在食源性致病菌污染状况。其中金黄色葡萄球菌污染比较严重,产肠毒素比例高,且对多种抗生素耐药,对青霉素产生普遍耐药, 对四环素、万古霉素和利福平耐药率较高, 对苯唑西林、环丙沙星、奎奴普丁/达福普汀和呋喃妥英等耐药率相对较低;对耐莫西沙星、利奈唑胺、替加环素和甲氧苄氨嘧啶/磺胺甲恶唑有较好的敏感性。     

2012年河南省市售生制速冻面米制品食源性致病菌污染状况监测

了解2012年河南省境内市售生制速冻面米制品中金黄色葡萄球菌和沙门菌的污染状况。方法 金黄色葡萄球菌、沙门菌检测及血清分型参照2012年《国家食品安全风险监测工作手册》,金黄色葡萄球菌肠毒素的测定参照mini-VIDAS试剂使用说明。结果 344份速冻面米制品中检出金黄色葡萄球菌和沙门菌共计55株,总检出率为15.99%,其中金黄色葡萄球菌49株(14.24%),沙门菌6株(1.74%)。金黄色葡萄球菌计数结果为0.2～110 cfu/g。49株金黄色葡萄球菌中22株金黄色葡萄球菌肠毒素阳性,阳性率为44.90%。6株沙门菌血清分型分属4个血清型:肠炎沙门菌、阿贡纳沙门菌、印第安纳沙门菌、德尔卑沙门菌。6株沙门菌对头孢唑啉、头孢替坦、阿米卡星、庆大霉素、妥布霉素均耐药,3株沙门菌对氨苄青霉素/舒巴坦、头孢曲松、氨曲南、呋喃妥因和复方新诺明的耐药率均为33.33%,对环丙沙星和左氧氟沙星的耐药率均为16.67%。结论 河南省市售生制速冻面米制品存在沙门菌和金黄色葡萄球菌的污染,其中沙门菌的检出率较低,但其安全风险较大；金黄色葡萄球菌虽未超标,但其检出率和肠毒素的阳性率均较高,应高度重视。     

六类食品中致病性细菌检测

为了解昌平区细菌对食品污染的特点，2004年采集6类305件食品，按照GB／T4789－2003食品微生物检验标准进行沙门菌、金黄色葡萄球菌、副溶血性弧菌、单核细胞增生性李斯特菌、0157：H7大肠杆菌5种致病菌检测。菌株鉴定应用API细菌鉴定系统，肠毒素检测用minVIDAS测试系统，单核细胞增生性李斯特菌毒力基因测定采用聚合酶链反应（PCR）。金黄色葡萄球菌检出率为16．07％，其中生肉、生牛奶、生食水产品检出率比较高，分别为25％、16．98％、27．27％；散装熟肉制品、乳制品也有检出，分别为4.29％、5％。在检出的49株金黄色葡萄球菌菌株中有31株产生肠毒素，占63．26％，其中生、熟肉类肠毒素阳性25株；从奶类、生食水产品中各检出3株。单核细胞增生性李斯特菌检出34株，检出率为11．15％，其中生肉检出率高达20％，其次为散装熟肉制品（8．57％）；另外从淡水鱼中检出4株单核细胞增生性李斯特菌。28株单核细胞增生性李斯特菌毒力基因（hly、iap、prfA）检测全部阳性。生肉中检出一株肠炎沙门菌。未检出O157：H7大肠杆菌、副溶血性弧菌。昌平地区金黄色葡萄球菌和单核细胞增生李斯特菌对食物的污染比较严重，生食品与加工后食品的检出率差异有显著性。     

近红外光谱建模法快速测定桔子精油中柠檬烯的含量

为了解日常检测分离株产肠毒素和耐药情况,探讨食源性金黄色葡萄球菌产毒素的类型及分布状况,研究其耐药特性,对本实验室2016年～2017年日常食品检测中的分离株,分别用全自动荧光酶联免疫法检测肠毒素总量和酶联免疫吸附法对肠毒素SEA～SEE进行分型,并用全自动微生物鉴定药敏分析系统进行药敏试验。结果表明,370份食品中分离到的29株金黄色葡萄球菌,产肠毒素的有16株,阳性率为55.2%,其中食物中毒分离株5株都为肠毒素阳性。产2种及以上肠毒素的菌株为12株,占41.4%。A型～E型常见肠毒素都有检出,其中产SEE的菌株最多,有12株,占41.4%,产SEA的菌株次之,为11株。29株食源性金黄色葡萄球菌对庆大霉素、妥布霉素、青霉素、安苄西林、苯唑西林、阿莫西林-克拉维酸、复方新诺名、克林霉素、红霉素、利福平、四环素均有不同程度的耐药,并出现多重耐药性,其中对青霉素和安苄西林的耐药率最高,均为82.8%,其次为红霉素44.8%。该研究的食品监测中分离到的金黄色葡萄球菌其产肠毒素率较高,主要的类型为SEE和SEA。而且分离得到的食源性金黄色葡萄球菌存在不同程度的耐药性和多重耐药现象,建议从各个环节加强监测,降低因耐药菌带来的食品安全风险。     

温州市食品中金黄色葡萄球菌污染状况及分子流行病学特征研究

目的了解温州市食品中金黄色葡萄球菌的污染状况,分析分离的金黄色葡萄球菌的耐药性、毒力基因分布及脉冲场凝胶电泳(PFGE)分子分型特征。方法依据GB 4789.10—2010《食品安全国家标准食品微生物学检验金黄色葡萄球菌检验》进行菌株分离鉴定,采用纸片法进行药敏试验,mini-VIDAS法和聚合酶链式反应(PCR)法分别进行肠毒素及其基因的检测,PFGE法进行分子分型。结果 4类食品388份样品中有16份样品检出金黄色葡萄球菌,检出率为4.12%,其中生畜肉和生禽肉检出率较高,分别为13.89%(5/36)和11.11%(4/36)。所有菌株均有不同程度的耐药,对青霉素耐药率最高(100.00%,16/16),其次为红霉素(56.25%,9/16),多重耐药率为18.75%(3/16),未检出对甲氧西林耐药的金黄色葡萄球菌。金黄色葡萄球菌肠毒素及其基因检测阳性率均为56.25%(9/16),其中seb、seg基因检出率较高,均为37.50%(6/16)。PFGE图谱分为12种PFGE带型。结论金黄色葡萄球菌在温州市食品中存在一定的污染率,且具有分子多态性、产肠毒素率及毒素基因携带率较高的特征,提示存在潜在的食品安全隐患。     

广州市白云口岸航空食品中金黄色葡萄球菌凝固酶基因分型及肠毒素基因研究

目的对2013—2015年从广州市白云口岸航空食品中分离的金黄色葡萄球菌进行基因分型研究,为食源性金黄色葡萄球菌分子溯源提供基础数据。方法以血浆凝固酶和肠毒素为目标基因,采用聚合酶链式反应(PCR)方法对9株金黄色葡萄球菌进行基因分型,其中6株为航空食品分离株,1株为配餐车间大门手拭分离株,2株为标准菌株。肠毒素基因检测包括5种传统肠毒素基因(sea、seb、sec、sed、see)和6种新型肠毒素基因(ser、seg、seh、sei、sej、sep)。结果 6株航空食品分离株的血浆凝固酶基因扩增分型结果为2个PCR型,酶切后得3种亚型;肠毒素基因检测结果显示有2株航空食品分离株含有肠毒素基因,检出率为33.3%(2/6),检出的基因为2种传统肠毒素基因(sec、sed)和4种新型肠毒素基因(ser、seg、sei、sej),均同时携带2种以上肠毒素基因。结论血浆凝固酶基因扩增分型结果显示,不同时间、不同采集地点存在相同的基因型,提示金黄色葡萄球菌存在交叉污染的可能性;航空食品分离株共检出6种肠毒素基因,提示金黄色葡萄球菌基因型多样性,应加强其他新型肠毒素基因检测。     

食源性金黄色葡萄球菌肠毒素基因型分布研究

目的 采用PCR法扩增食源性金黄色葡萄球菌中肠毒素基因以了解该菌肠毒素基因携带情况,比较食物中毒和食品监测来源菌株中肠毒素基因检出率差异.方法 合成sea、seb、sec、sed和see五种肠毒素基因特异性引物,用常规PCR方法扩增食物中毒和食品监测来源菌株中各自肠毒素基因,同时采用mini-VIDAS检测食物中毒来源菌株中肠毒素.结果 110株菌株中有30株检出肠毒素基因,检出率为27.3％,肠毒素基因阳性菌株均只检出1种肠毒素基因.其中来自2起食物中毒的14株菌株均检出seb型肠毒素和相关基因,检出率为100％.来源于食品监测样本的96株菌株中有16株检出肠毒素基因,检出率为16.7％,包括sea型4株、seb型2株、sec型4株、sed型6株.结论 在宁波市食品监测中所分离的金黄色葡萄球菌所携带的肠毒素基因主要有sea、seb、sec和sed四型,而seb型肠毒素是引起金黄色葡萄球菌肠毒素所致食物中毒的主要因素.     

牦牛屠宰中金黄色葡萄球菌分离菌株的流行特征

为研究牦牛屠宰过程中金黄色葡萄球菌分离菌株的流行特征,本实验选取成都市某牦牛屠宰场采集样品共计150份,采用Baird-Parker选择性培养基初步筛选出金黄色葡萄球菌疑似菌株,通过聚合酶链式反应检测携带金黄色葡萄球菌特有耐热核酸酶基因的菌株。进一步检测分离菌株21种肠毒素基因、6种毒力基因、4种耐消毒剂基因以及14种耐药基因的携带情况。并采用K-B纸片扩散法检测菌株对24种抗生素的耐药表型。结果表明,从150份牦牛屠宰场采集到的样品中,检出金黄色葡萄球菌67株,检出率为44.67%,其中牦牛胴体拭子和环境拭子采样中金黄色葡萄球菌的检出率较高,分别为56.67%和51.61%;分离菌株中共检出12种肠毒素基因,其中selx、seu和sej基因的检出率高;分离菌株检测出溶血毒素基因、杀白细胞素基因以及qacA/B、qacG、qacH等耐消毒剂基因;有11种耐药基因检测出阳性条带,其中,耐甲氧西林基因mecA检出率为62.69%,氨基糖苷类耐药基因(aac6’/aph2’)和大环内脂类耐药基因(ermA、ermB)的检出率较高。K-B纸片扩散法对67株分离菌株进行24种抗生素的药敏实验结果表明大部分受试菌株存在多重耐药性。本实验通过对牦牛屠宰过程金黄色葡萄球菌流行特征进行调查,发现牦牛屠宰环节存在携带毒力基因且多重耐药金黄色葡萄球菌的污染,有可能进入食物链对消费者健康存在潜在威胁,研究结果为评价牦牛屠宰环节金黄色葡萄球菌安全风险提供参考依据。     

扬州市食品中7种食源性致病菌污染状况及耐药性研究

为确定易受污染的食品,研究食源性病原菌耐药性状,为制定HACCP控制食源性疾病提供科学依据,对扬州市食品中沙门菌、E.coliO157:H7、单核细胞增生李斯特菌、金黄色葡萄球菌、副溶血性弧菌、空肠弯曲菌和小肠结肠炎耶尔森菌污染状况进行分析。在957份食品中共检出沙门菌、单核细胞增生李斯特菌、金黄色葡萄球菌、副溶血性弧菌90株,检出率为9.40%。其中沙门菌检出率为2.09%,单核细胞增生李斯特菌检出率为4.49%,金黄色葡萄球菌检出率为2.72%,副溶血性弧菌检出率为0.10%,未检出E.coliO157:H7。在80件生肉类试样中检出空肠弯曲菌8株,小肠结肠炎耶尔森菌6株。对分离出的沙门菌、单核细胞增生李斯特菌、金黄色葡萄球菌进行药敏试验,结果表明3种致病菌对部分抗生素多重耐药。扬州市食品中主要危害因素为沙门菌、单核细胞增生李斯特菌、金黄色葡萄球菌及其对抗生素的多重耐药。食物链是病原菌耐药性产生的重要环节。加强生肉制品、散装熟食及生牛奶的卫生管理,控制动物饲料抗生素添加剂的使用并严格遵守休药期以防止耐药菌株的产生,对控制食源性疾病、保证食品安全具有很重要的意义。     

一起由金黄色葡萄球菌引起食物中毒的实验室诊断

目的对一起食物中毒进行相关样品的实验室检测,针对分离病原菌进行分子分型溯源和耐药分析。方法对可疑食品(冰激凌、牛奶)样品、患者呕吐物和粪便标本使用国家标准或其他方法进行沙门菌、志贺菌、致泻大肠埃希菌、金黄色葡萄球菌、单核细胞增生李斯特菌、蜡样芽胞杆菌和诺如病毒检测。对检出的金黄色葡萄球菌进行肠毒素检测、脉冲场凝胶电泳(PFGE)分型和抗生素敏感性检测。结果从生产冰激凌剩余牛奶及冰激凌样品中检出金黄色葡萄球菌12株,患者呕吐物和粪便标本中检出4株,菌株均产生A+C+E混合型肠毒素,PFGE显示患者呕吐物、粪便、中毒同批冰激凌样品、生产冰激凌用牛奶中检出的金黄色葡萄球菌菌株同源性为100.0%;药敏结果显示,这16株菌株均对青霉素和红霉素耐药。结论本起事件是由冰激凌加工点使用了被金黄色葡萄球菌污染且产生大量肠毒素的牛奶生产冰激凌所致。建议监管部门加强对农村食品小作坊、牛奶供应站等生产经营场所的监管,预防类似事件的发生。     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.