A semiquantitative approach for evaluating safety assurance levels for Salmonella spp. throughout a food production chain

Various safety assurance measures are implemented in Switzerland throughout the food production chain to prevent foods of animal origin from being contaminated with Salmonella. The data that are generated from the implementation of these measures are dispersed and heterogeneous. This hinders a general overview and makes a comprehensive national evaluation of the safety assurance level difficult. A semiquantitative method that considers the quality and relevance of the various safety assurance measures for Salmonella spp. was developed. The method uses the data generated from the implementation of safety assurance measures on a national basis (gathered by interviewing stakeholders in the production step). By assembling and analyzing the data systematically, the safety assurance level for Salmonella spp. can be evaluated at every step of the food production chain. This method allows the detection of strengths and weaknesses of the safety system. The systematic evaluation procedures permit comparisons between production steps and product categories. The method was used for evaluating the safety assurance levels throughout the production chain of eggs and egg products in Switzerland. Results of the analysis showed that the overall safety assurance levels for Salmonella spp. at all production steps for eggs and egg products were good. The relatively straightforward implementation of the method made it particularly appropriate in the context of a preliminary evaluation. The method does not have the same high level of detail that is provided by microbial quantitative risk assessments, but it allows an analyst to provide meaningful results when the large amount of data required for a quantitative approach are not present while including the entire "farm to fork" continuum. It may be used as a basis for more in-depth assessments of food safety levels within various production sectors. The method could be adapted for evaluating the safety assurance for other zoonotic foodborne pathogens of interest, such as Campylobacter spp.     

Evaluation of a polymerase chain reaction-based test for detecting Salmonella spp. in food samples: Probelia Salmonella spp

A commercially available polymerase chain reaction (PCR) kit was evaluated for the detection of Salmonella spp. in food samples. The test combines PCR amplification and sandwich hybridization of the amplified DNA in microtiter plates. The sensitivity and specificity was evaluated with 52 Salmonella strains and 51 non-Salmonella strains and showed that the test was entirely reliable. The threshold sensitivity was 10(2) CFU/ml. The limit of detection of dead cells that determines the minimum detection level of dead cells in food samples was superior to 10(6) CFU/25 g, a level rarely achieved in naturally contaminated samples. After an 18-h pre-enrichment step, the test could detect viable Salmonella in artificially contaminated food samples, even for the lower contamination level (3 CFU/25 g). There was complete agreement between the PCR test and the ISO 6579 bacteriological reference method with artificially contaminated samples. Regarding the accuracy of the results obtained from 253 naturally or noncontaminated foods and from 32 artificially contaminated foods, the agreement percentage was 99.6%. The fidelity of the technique was evaluated in a collaborative study with eight European laboratories and showed a correlation of 98.4%.     

Perfluorooctane sulphonate (PFOS) throughout the food production chain

Perfluorooctane sulphonate (PFOS) is a persistent organic pollutant with adverse effects on human health. Since dietary intake plays an important role in human exposure, the transfer of PFOS throughout the food chain needs further investigation. The aim of this paper is to give an overview of PFOS concentrations and transfer for the various chain steps from farm-to-fork. This reveals that most research focused on levels of PFOS in surface water and fish but data on soil and crops are largely missing. Furthermore, the uptake of PFOS by farm animals and subsequent transfer into meat and animal products needs further attention, as these products will eventually be consumed by the human population. Once the necessary data gaps are filled, the contribution of the various chain steps on the total PFOS intake can be established. Moreover, the effect of pollution events on the food chain can be established enabling appropriate actions in order to protect consumer health.     

重大活动食品安全保障中沙门氏菌现场检测方法的建立

目的 针对重大活动食品安全保障工作对于现场检测的时间短和设备简单的要求及供应食品的类型,建立经加热处理和未经加热处理食品的沙门氏菌检测方法。方法 将重组酶聚合酶等温扩增(recombinase polymerase amplification, RPA)与侧流免疫层析法(lateral flow immunoassay, LFS)结合,建立RPA-LFS方法对切片水果样品进行检测,再加上叠氮溴化丙锭(propidium monoazide,PMA)处理,建立PMA-RPA-LFS方法,对熟肉制品进行检测。并通过检测人工污染样品及实际样品验证方法的适用性。结果 RPA-LFS的沙门氏菌纯菌检出限为2.0×10¹ CFU/mL,新鲜水果基质检出限为2.0×10¹ CFU/g。对人工污染样品和实际样品的检测结果与GB4789.4—2016《食品安全国家标准食品微生物学检验沙门氏菌检验》方法的结果一致。PMA-RPA-LFS的PMA处理方法为0.1%脱氧胆酸钠37℃处理20 min,加入10μg/mL PMA,室温避光孵育10 min,曝光15 mi...     

Multiplex PCR for the simultaneous detection of Salmonella spp. and Salmonella Enteritidis in food

Multiplex PCR assay (mPCR) for the detection of Salmonella spp. and S. Enteritidis was developed in this study using artificially contaminated chicken carcasses. The assay showed 100% specificity to detect approximately 1 CFU of Salmonella in 10 g of chicken skin after non‐selective enrichment. The mPCR was evaluated in Minas cheese, fresh pork sausage and chicken carcasses commercially available. Salmonella spp. was detected in nine of sixty‐six chicken carcasses, five of fifty‐two cheese samples, and five of fifty‐two sausage samples. The serovar Enteritidis was detected in two samples of contaminated sausage. The mPCR results were confirmed by conventional culture and biochemical identification of the isolates. Serotyping confirmed the presence of S. Enteritidis in sausage samples and showed contamination by serovars Schwarzengrund and Montevideo in chicken carcasses.     

Combination of immunomagnetic separation and polymerase chain reaction for the simultaneous detection of Listeria monocytogenes and Salmonella spp. in food samples.

A method that combined the immunomagnetic separation (IMS) technique and the multiplex polymerase chain reaction (PCR) method (i.e., the IMS-mPCR method) was developed for simultaneous detection of Listreria monocytogenes and Salmonella spp. in food samples. When only the multiplex PCR method was used, it was found that if cell numbers of each of the two target organisms (L. monocytogenes and Salmonella spp.) were above the detection limit, but differed by more than 2 logs-e.g., n x 10(7) to n x 10(4) or n x 10(6) to n x 10(3)--the organism presenting the lower numbers might go undetected. Following the enrichment step with universal preenrichment (UP) broth, if an IMS method using equal quantities of anti-Listeria and anti-Salmonella immunomagnetic beads was performed prior to PCR, both pathogens could be detected unambiguously. Such results could be obtained for target organisms in food samples, such as milk, dairy, and meat products, if similar enrichment and IMS steps were performed prior to PCR.     

沙门氏菌快速检测板在食品检测中的应用研究

目的研究沙门氏菌快速检测板在食品检测中的应用。方法以标准菌株为测试样本,参照GB4789.4-2010验证沙门氏菌快速检测板的灵敏度、特异性、假阳性率、假阴性率、准确度,同时利用卡方检验分析阳性率显著性差异。结果沙门氏菌快速检测板最低检测限能达到10~0 CFU/m L,灵敏度为100%,不存在假阴性,特异性为92%,假阳性率为8%,准确度为95%,显著性差异卡方值卡Χ~2为0.5,均达到定性方法验证的相关指标。结论沙门氏菌检测板技术方法具有快速准确、灵敏度高、操作简单的特点,可以作为一种快速筛查方法广泛运用在食品安全微生物检测领域。     

Microbial performance of food safety management systems implemented in the lamb production chain

The actual microbial status of the lamb production chain at three slaughterhouses, one processing plant, and five butcher shops selling whole or cut lamb carcasses to consumers was assessed with a previously developed microbial assessment scheme. All studied establishments had a food safety management system (FSMS) that was implemented according to legislative requirements. Microbial safety level profiles were constructed for each establishment and provided clear indications of which pathogens, hygiene indicators, or utility parameters required attention to improve the performance of the microbiological control protocols of the implemented FSMS. The highest contamination was found in the slaughterhouses in samples taken from the meat products (aerobic mesophilic plate counts [AMPs] of 3.40 to 6.63 log CFU/cm(2) and Enterobacteriaceae counts of 1.00 to 4.62 log CFU/cm(2)), contact surfaces (AMPs of 2.44 to 8.92 log CFU/cm(2)), and operators' hands and/or gloves (AMPs of 2.84 to 8.09 log CFU/cm(2)), especially after hide removal and evisceration. The microbial assessment scheme is a useful tool for providing insight into the actual microbiological results achieved with an FSMS implemented in establishments at various stages along the lamb production chain.     

食品能力验证中沙门氏菌的分离和鉴定

目的为了提升实验室食品中沙门氏菌检测能力,增强实验室竞争能力,本实验室参加了中国食品药品检定研究院组织的沙门氏菌检测能力验证活动。方法依据中华人民共和国国家标准GB 4789.4-2010,采用传统分离方法和血清学鉴定,联合全自动微生物生化鉴定系统(VITEK2-compact)对分离出的疑似菌进行生化鉴定。结果编号为CODE1样品+CODE1奶粉混合样检出纽波特沙门氏菌和科林德尔沙门氏菌,CODE3样品+CODE3奶粉混合样检出维普拉沙门氏菌、鼠伤寒沙门氏菌和埃科沙门氏菌,其余8个样品未检出。结论顺利完成本次能力验证活动。     

Detection of Salmonella spp. in tropical seafood by polymerase chain reaction

The incidence of Salmonella spp. in tropical seafood was studied using standard microbiological techniques and polymerase chain reaction (PCR). Six of 20 finfish (30%), 4 of 20 clams (20%) and 1 of 20 shrimp (5%) were positive by culture techniques and by PCR. In a comparative study of different selective enrichment broths and selective plating media, more than one enrichment broth and selective agar were found to be necessary for efficient detection of Salmonella from seafood. Selenite cystine broth (SCB) was found to be more efficient compared to tetrathionate broth (TTB) while both bismuth sulfite agar (BSA) and hektoen enteric agar (HEA) were equally effective as selective plating media for fish. In the case of clams, HEA was found to be more effective. The presence of Salmonella spp. could be detected by PCR amplification of DNA extracted directly from the enrichment broths. In two cases, enrichment broths that were positive by PCR did not yield Salmonella by conventional methods.     

冷链即食食品生产加工环境中李斯特氏菌属检测方法的建立与应用

目的 开发一种建立可用于冷链即食食品生产加工环境中李斯特氏菌属的分离与检测方法,应用于对生产企业中的环境进行监控。方法 本研究结合GB4789. 30-2016国标方法和美国美国食品药品监督管理局细菌学分析手册Food and Drug Administration Bacteriological Analytical Manual（FDA BAM ）FDA BAM 单增李斯特氏菌检测方法,通过制备冻干定量菌球模拟增菌实验,对增菌液中萘啶酮酸和吖啶黄素的添加时间、头孢曲松钠的添加浓度进行了研究,确定最佳增菌方式和头孢曲松钠浓度,并将其应用到实际冷链即食食品生产企业环境中李斯特菌属的分离检测中。,确认该方法的可行性。结果 3种李斯特氏菌属和背景菌的冻干菌球的浓度分别为102 CFU/球及103 CFU/球。通过模拟增菌实验,延后4小时 h使用添加剂,可使李斯特氏菌属及单增李斯特氏菌的检出率均提高10%,在此基础上头孢曲松钠添加量在6 μg/mL至~8 μg/mL时,李斯特氏菌属及单增李斯特氏菌的检出率均为100%。结论 以上该方法应用在生产企业实际环境监测中,可提高李斯特氏菌属的检出率。该方法可应用于为冷链即食食品生产企业中李斯特氏菌属的环境监控,为生产企业的环境监控提供了技术保障。     

Advances in enteropathogen control throughout the meat chicken production chain

Enteropathogens, namely Salmonella and Campylobacter, are a concern in global public health and have been attributed in numerous risk assessments to a poultry source. During the last decade, a large body of research addressing this problem has been published. The literature reviewed contains review articles on certain aspects of poultry production chain; however, in the past decade there has not been a review on the entire chain—farm to fork—of poultry production. For this review, a pool of 514 articles were selected for relevance via a systematic screening process (from >7500 original search articles). These studies identified a diversity of management and intervention strategies for the elimination or reduction of enteropathogens in poultry production. Many studies were laboratory or limited field trials with implementation in true commercial operations being problematic. Entities considering using commercial antienteropathogen products and interventions are advised to perform an internal validation and fit-for-purpose trial as Salmonella and Campylobacter serovars and biovars may have regional diversity. Future research should focus on nonchemical application within the processing plant and how a combination of synergisticinterventions through the production chain may contribute to reducing the overall carcass burden of enteropathogens, coupled with increased consumer education on safe handling and cooking of poultry.     

Aptamers for safety and quality assurance in the food industry: detection of pathogens

Aptamers are biomolecular ligands composed of nucleic acids. They can be developed to bind specifically to a range of target molecules and subsequently exploited in a fashion analogous to more traditional biomolecules such as antibodies. Methods for the production of aptamers and their potential applications to the food industry in the form of rapid assays and biosensors are discussed. In contrast to antibody‐based diagnostics, aptamers can be produced in animal‐free systems which have clear ethical and financial benefits. This review identifies a need for the development of new aptamers with specificity against micro‐organisms and highlights their potential use for the detection of food‐borne pathogens.     

Prevalence and characteristics of Shiga toxin-producing Escherichia coli, Salmonella spp. and Campylobacter spp. isolated from slaughtered sheep in Switzerland

Caecum samples collected from 653 slaughtered sheep from two Swiss abattoirs were examined. The aim of this study was: (i) to determine the prevalence of Shiga toxin-producing Escherichia coli (STEC), Salmonella spp. and Campylobacter spp.; (ii) to further characterize isolated strains; and (iii) to discuss the results obtained with their relevance to food safety. The percentage of samples testing positive for STEC by a polymerase chain reaction was 29.9%. The prevalence of positive Salmonella spp. samples was 11.0% and of Campylobacter spp. 17.5%. In 55.3% of the 76 isolated non-O157 STEC strains, stx2 variants (mostly stx2d) were detected. Additional virulence factors were harbored by 55.3% of the STEC strains, 10.5% of them being eae positive, 55.3% ehxA positive and 2.6% astA positive. All isolated salmonella were identified as Salmonella enterica subsp. diarizonae serovar 61:k:1,5,(7). Pulsed-field gel electrophoresis (PFGE) was performed for genotyping and 22 different restriction endonuclease digestion profiles were found among these strains for the different farms of origin. Of the 114 isolated Campylobacter spp. strains, 64.9% were shown to be Campylobacter jejuni and 35.1% Campylobacter coli, nine strains showed resistance against tetracycline, ciprofloxacin/nalidixic acid or streptomycin. In conclusion, sheep are a reservoir for the pathogens of latent zoonoses as non-O157 STEC, S. enterica subsp. diarizonae and Campylobacter spp. The maintenance of slaughter hygiene is consequently of crucial importance. It can be measured in daily practice by "slaughter-process-controls" and regular microbiological monitoring of carcasses. These are valuable tools for verifying slaughter hygiene according to hazard analysis critical control point principles.     

环介导等温扩增方法在食品中沙门菌检测的应用和评价

将环介导等温扩增检测方法应用于食品中沙门菌的检验,并在检测方法特异性、灵敏度等方面与实时荧光PCR和传统检测方法进行比较。方法 针对沙门菌属高度保守的fimY基因设计环介导等温扩增检测引物并优化反应体系,在特异性、灵敏度和实际样品检测等方面与实时荧光PCR及传统检测方法比对。结果 本研究建立的LAMP方法检测沙门菌93株和非目标菌31株,具有良好的特异性。在纯培养、无需增菌情况下,其检测灵敏度为6.4×10²cfu/ml,与实时荧光PCR方法相当。食品基质添加试验中,环介导等温扩增方法检测低限为2cfu/25g样品;对45份实际食品样品检测结果表明,该方法实际样品检出率为11.1%,与实时荧光PCR及传统方法检测结果一致。结论 本研究建立的沙门菌环介导等温扩增检测方法具有良好的特异性,检测灵敏度与实时荧光PCR相当,适用于沙门菌的快速筛选。     

食品链质量安全追溯体系的建立

2015年实施新修订的《食品安全法》中第42条规定:"国家应建立食品安全全程追溯制度"。随着食品工业化的发展和消费者对食品安全要求的提高,建立食品全程追溯系统,对于不安全食品的召回以及查找食品链中的不安全问题点将起到非常重大作用,已成为食品安全保障工作的重要措施。根据追溯涉及到的食品供应链组织,可以将追溯划分为内部追溯和外部追溯。食品链中食品生产加工环节的追溯就属于内部追溯,目前我国较多食品企业尚未建立完整的食品安全管理体系且自动化程度较低,另外我国食品企业生产的食品种类繁多,缺少指导性文件导致内部追溯存在较大的困难。本文对食品生产加工环节追溯的现状与发展进行概述,建议通过健全同类产品追溯系统以及提高食品企业自动化程度建立完善的企业内部追溯系统,以更好地保障食品安全工作。     

Polymerase chain reaction (PCR) in the quality and safety assurance of food: Detection of soya in processed meat products

A new method for the specific and sensitive detection of soya (Glycine max) in processed meat products has been developed using polymerase chain reaction (PCR) technology. The presence of soya deoxyribonucleic acid (DNA) from several soya protein concentrates was determined with two pairs of specific oligonucleotides yielding a 414-bp (bp=base pair) fragment and an internal 118-bp fragment amplified from the soya lectinLe1 gene. The test detected DNA from textured soya protein concentrates in meat products at a level of 1% and was confirmed by a commercially available enzyme-linked immunosorbent assay (ELISA).     

电子商务在食品供应链及食品安全中的应用

作为一种商务模式,电子商务在很多领域中得到了广泛应用。利用电子商务能够充分发挥食品供应链的优势,通过食品供应链和电子商务的有机结合,食品企业能够更好地保障食品安全,有效应对行业内日益激烈的市场竞争,全面提升企业自身的市场竞争力。本文对电子商务在食品供应链及食品安全中的作用和优势进行了论述和分析,介绍了基于电子商务的食品供应链和食品安全管理的理念,并立足于信息共享机制的建立和协同整合对其前景进行了介绍和分析。     

ISO22000体系在大型活动餐饮服务食品安全保障中的应用

摘 要：目的：在大型活动餐饮服务食品安全保障中应用ISO22000 食品安全管理体系, 预防与控制大型活动餐饮服务食品安全保障过程中可能存在的潜在危害。方法：根据 ISO22000 食品安全管理体系标准, 在前提方案（PRP）建立的基础上,对餐饮服务食品安全保障各道工序进行识别和评估,完善了操作性前期方案（OPRP）,确定关键控制点（CCP）,制定了关键限值和控制限值,预防、消除或减少食品安全危害至规定的可接受水平。结果:通过操作性前提方案(OPRP)与HACCP 工作计划,确定6个操作性前期控制点和6个关键控制点（CCP）,构建了餐饮服务食品安全管理体系模式。结论:通过制定操作性前提方案, 将其与HACCP 中的关键控制点结合,将食品安全危害因素降到最低限度, 更好地保障了大型活动期间的餐饮服务食品安全。