一起疑似食源性诺如病毒胃肠炎事件病原分子生物学特征分析

目的研究厦门市思明区一起聚集性胃肠炎事件的诺如病毒的分子生物学特征。方法将收集到的11份肛拭子标本及1份生蚝样品,采用实时荧光定量逆转录-聚合酶链反应(RT-PCR)方法检测诺如病毒核酸,阳性标本再进行实时荧光定量RT-PCR扩增,扩增产物经过凝胶电泳分析后,进行序列测定,确定基因型,并进行系统发育树分析。结果 11份肛拭子标本中检出5株GⅠ组诺如病毒株,2株测序成功,检出4株GⅡ组毒株,3株测序成功;1份生蚝样品中检出1株GⅠ组毒株,测序成功。对测序成功的6株毒株进行同源性分析,GⅠ.2型毒株所测序列与2014年上海株KP325648等6株参考株高度同源,GⅡ.17型毒株所测序列与2015年韩国株KT384078等8株参考株高度同源,证实这是一起由GⅠ.2和GⅡ.17型诺如病毒混合感染引起的聚集性胃肠炎事件,GⅡ.17型毒株为厦门市首次报道。结论此次聚集性胃肠炎事件是由诺如病毒引起,且为GⅠ.2与GⅡ.17型毒株混合感染引起。     

秦皇岛市售生菜、草莓中诺如病毒监测分析

目的 调查秦皇岛市诺如病毒污染的高风险食品生菜和草莓中诺如病毒的污染状况。方法 2015年9月至2016年6月采集市售的生菜201份、草莓136份, 利用实时荧光RT-PCR法检测诺如病毒, 在样品中添加Mengo病毒进行过程控制, 并根据Mengo病毒标准曲线计算 诺如病毒回收率。结果 Mengo病毒回收率均达到了ISO/TS 15216-2-2013对 病毒回收率＞1%的要求。同时对201份生菜样品进行检测, 检出诺如病毒阳性标本9份, 总检出率为4.5%, 其中GⅠ型检出率为0.5%(1/201); GⅡ型检出率为3.5%(7/201); GⅠ型和GⅡ型同时检出率为0.5%(1/201)。136份草莓样品中检出阳性标本4份, 总检出率为2.9%, 其中GⅠ型检出率为0.7%(1/136); GⅡ型检出率为2.2%(3/136)。结论 秦皇岛市售蔬菜、浆果中部分存在诺如病毒污染, 诺如病毒检出率在不同采样环节以及时间分布比较差异无统计学意义, 需要进一步加强日常监测。     

2015~2016年河北省贝类水产品中诺如病毒污染状况研究

目的 对2015~2016年河北省6个设区市的市售牡蛎、海虹、血蚶样品中的诺如病毒进行连续一年的检测, 了解河北省贝类水产品中诺如病毒污染状况。方法 分离贝类水产品消化腺, 用蛋白酶K消化后进行前处理, 提取RNA, 用一步法实时荧光逆转录聚合酶链式反应法检测GⅠ型和GⅡ型诺如病毒。对河北省贝类水产品的诺如病毒污染状况进行分析。结果 共采集691份贝类样品进行检测, 其中仅检出GⅠ型阳性样品16份, 阳性率2.32%; 仅检出GⅡ型阳性样品22份, 阳性率3.18%; 同时检出GⅠ和GⅡ型的阳性样品4份, 阳性率0.58%; 总阳性率6.08%。2016年6~7月阳性率最高。沿海地区样品阳性率为内陆地区的2.35倍, 有统计学差异(χ2=8.58, P<0.01)。结论 河北省市售贝类水产品中部分存在诺如病毒污染, 需要加强对贝类水产品的诺如病毒污染检测和控制, 特别是沿海地区, 降低诺如病毒引起的食源性腹泻的疾病负担。     

顺义区市售双壳贝类中副溶血性弧菌和诺如病毒的耐药性及分型研究

目的了解北京市顺义区部分市售双壳贝类中副溶血性弧菌及诺如病毒的污染情况,为相关感染性腹泻的防治提供依据。方法 2017年7～10月采集顺义区市场的双壳贝类,取适量样品分离其消化腺,进行样品前处理,提取病毒RNA后采用实时荧光定量逆转录-聚合酶链式反应(RT-PCR)法检测诺如病毒。剩余样品按照GB4789.7—2013《食品安全国家标准食品微生物学检验副溶血性弧菌检验》进行副溶血性弧菌的分离鉴定。对检出的副溶血性弧菌进行毒力基因(tlh,tdh,trh)检测、耐药性分析和脉冲场凝胶电泳(PFGE)分子分型。结果 50份双壳贝类样品中有18份检出副溶血性弧菌(18株),检出率为36.0%;有8份样品携带诺如病毒。分离的副溶血性弧菌17株为tlh+tdh-trh-型,1株为tlh-tdh-trh-型;所有副溶血性弧菌均对氨苄西林耐药,对其他抗生素均敏感;PFGE图谱聚类后呈现多态性,存在多个克隆群。诺如病毒只在10月份检出,分布于牡蛎、蛏子和扇贝中,均为GⅡ型核酸阳性。结论顺义区市售双壳贝类中存在副溶血性弧菌和GⅡ型诺如病毒,需警惕感染风险。分离的副溶血性弧菌呈现多态性,但毒力基因携带率较低,对大多数抗生素敏感。     

2011—2012年广东省市售牡蛎中诺如病毒污染调查分析

目的 调查2011-2012年广东省市售牡蛎中诺如病毒的污染状况,为采取有效措施减轻牡蛎中诺如病毒污染程度提供建议,达到预防和控制食用牡蛎引起诺如病毒胃肠炎疾病的目的.方法 2011年3月-2012年10月,在广东省部分沿海城市进行市售牡蛎的采样检测,对其诺如病毒污染状况进行连续两年监测,采用荧光RT-PCR检测诺如病毒阳性标本基因分型,并对不同城市、季节及场所牡蛎中诺如病毒的污染情况及基因分型情况进行比较.结果 牡蛎中诺如病毒总检出率为14.9％ (41/275);四个季节牡蛎中诺如病毒检出率依次为4.4％、15.7％、18.2％和36.7％;从基因分型分析,GⅠ型病毒株检出率为4.0％,GⅡ型病毒株检出率为6.2％,GⅠ和GⅡ型病毒株同时检出率为4.7％.结论 2011-2012年广东省市售牡蛎的诺如病毒污染情况在市场、餐饮场所以及不同地区间比较差异无统计学意义,其基因分型间比较差异无统计学意义,但呈现明显季节性特点,以冬季污染最严重.     

秦皇岛市部分腹泻患者粪便样本中诺如病毒监测

目的监测秦皇岛市部分诺如病毒引起病毒性腹泻情况,并对阳性样本进行分型。方法收集哨点医院病腹泻患者粪便标本共200份,采用实时荧光定量PCR方法 (real-timeRT-PCR)检测病毒核酸,Mengo病毒作为过程控制和扩增控制,检测诺如病毒回收率和抑制率。结果 Mengo病毒回收率均1%,PCR抑制率≤2%,符合检测要求。检测出病毒阳性15例,其中诺如病毒GⅠ型2例, GⅡ型13例。结论本次采集的样本中诺如病毒流行型分别为GⅠ和GⅡ型,其中以GⅡ组毒株流行为主,诺如病毒阳性率与性别、年龄无关。     

2019年连云港市农贸市场双壳贝类中诺如病毒污染状况调查

目的了解连云港市农贸市场双壳贝类中诺如病毒污染状况。方法于2019年6、8和11月在连云港三县三区各采集10份双壳贝类食物,共180份,及时分离消化腺于-75℃保存,采用实时荧光定量PCR检测诺如病毒基因型。结果 5种双壳贝类中诺如病毒基因总检出率为26.67%(48/180),基因型分型中GⅠ型检出率为5.00%(9/180)、GⅡ型检出率为17.78%(32/180)、GⅠ+GⅡ型检出率为3.89%(7/180);诺如病毒基因检出率在采样月份、地区分布无差异;帘蛤科诺如病毒检出率最高。结论连云港市农贸市场双壳贝类诺如病毒携带形势严峻,分布特征具有特殊性,亟需明确本地的诺如病毒传播模式并采取相应防控措施。     

北京市市售牡蛎中诺如病毒核酸检测及定量分析

目的针对北京市市售牡蛎样品中诺如病毒污染水平及污染浓度进行定量分析研究。方法分离牡蛎消化腺,将消化腺匀浆处理,加入含有蛋白酶K的磷酸盐缓冲液,进行样品前处理,用试剂盒提取病毒RNA,用一步法实时荧光逆转录聚合酶链式反应(real time RT-PCR)检测诺如病毒RNA,并对阳性样品进行定量分析。结果共检测牡蛎样品356份,其中GGI阳性样品12份,GGII阳性样品39份,GGI和GGII同时为阳性的样品6份。对阳性样品中的诺如病毒核酸定量分析,核酸浓度在3.7×10~3~2.8×10~5基因拷贝/g(消化腺)之间。结论北京市市售牡蛎中存在诺如病毒污染的情况,需要加强对牡蛎中诺如病毒的污染监测,并开展污染水平风险评估,保障消费者食用安全,降低由诺如病毒引起的腹泻病的疾病负担。     

贻贝中诺如病毒荧光定量反转录PCR检测及北京市污染情况调查

目的监测北京市市售贻贝中诺如病毒(NoV)的污染率及污染浓度,为贝类样品中诺如病毒的风险评估提供基础数据。方法解剖并分离贻贝的内脏团,将内脏团研磨至均质,加入磷酸盐缓冲液振荡60 min,提取病毒颗粒。提取病毒RNA,荧光定量反转录PCR检测诺如病毒,并进行定量分析。结果共检测293份贻贝样品,总阳性率为9.22%(27/293),其中诺如病毒基因组Ⅰ(GGⅠ)占阳性样品数的37.04%(10/27),基因组Ⅱ(GGⅡ)占阳性样品数的62.96%(17/27),未检测到同时携带GGⅠ和GGⅡ的样品。阳性样品中诺如病毒浓度范围在6.20×10~3~3.15×10~5基因拷贝/g(内脏)之间。结论北京市市售贻贝中存在诺如病毒污染。     

2015-2016年河北省腹泻散发病例中诺如病毒感染的流行病学特征分析

目的了解2015-2016年河北省腹泻散发病例中诺如病毒感染的流行病学特征。方法收集2015年9月～2016年12月河北省部分医院肠道门诊腹泻病例便样本及流行病学相关资料,采用RT-PCR方法检测诺如病毒并进行数据分析。结果在1240样本中,诺如病毒阳性58份,阳性率为4.68%;诺如病毒阳性率存在地域差异,邢台地区阳性率最高为10.08%;全年均有散发病例但在冬春季节出现明显的发病高峰;基因型以GⅡ型为主(4.28%),GⅠ型阳性率0.40%;易感人群为婴幼儿(0～6岁)和老年组(66～),其感染不存在性别差异。结论诺如病毒是河北省散发感染性腹泻的重要病原,应加强对诺如病毒的监测,并进一步研究其变异,为诺如病毒感染的预防和控制提供科学的依据。     

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.