我国食品微生物定量风险评估的研究进展

近10余年来,我国政府重视食品安全并逐渐加强风险分析体系的构建和实施。根据历年来国家卫生与计生委的统计数据,表明由致病微生物导致的食物中毒发病率一直高于其他危害。食源性致病菌引起的食品安全风险是全球性问题,发展中国家面临的情况更为严峻,因此加强我国微生物定量风险评估以减少与发达国家的差距,从国家层面上势在必行。特别是2009年我国颁布实施《食品安全法》和2011年成立国家食品安全风险评估中心（ChinaNational Center for Food Safety Risk Assessment,CFSA）以来,已有不少针对国内具体食品致病菌情况开展的食品微生物定量风险评估（quantitative microbial risk assessment,QMRA）研究。本文对2000年至今我国已开展的QMRA研究,包括涉及的食品、致病菌、微生物预测模型、剂量-效应模型等进行详细综述。同时指出我国开展QMRA面临的技术性难题及解决方法,并对采用QMRA结果用于构建危害分析与关键控制点（Hazard Analysis and CriticalControl Point,HACCP）和食品安全目标（ food safety objective,FSO）以及执行目标（performance objective,PO）的应用前景进行探讨。建议加强风险评估与风险管理的互动交流、进一步完善风险监测、微生物限量制定和国际合作,在完善实施指南的基础上针对我国具体国情开展更多具有科学性和系统性的QMRA研究。     

食源性致病菌风险评估研究进展

食源性致病菌是食源性疾病的首要病因, 由其引起的食源性疾病长期以来一直是食品安全的主要威胁, 尤其在发展中国家,形势更严峻, 应引起重视。食品安全风险评估在降低食品安全风险、保障食品安全中发挥的重要作用日益显著。本文对近年来国内外食源性致病菌风险评估的研究进展进行综述,介绍了风险评估实际应用过程中我国学者对国外模型构建的利用和优化, 并总结我国食源性致病菌风险评估中存在的问题, 为更好地开展食源性疾病监测和食源性致病菌风险评估提供参考。     

人工模拟胃肠道模型在食源性致病菌异质性研究中的应用进展

探究食源性致病菌在人体胃肠道环境中的异质性以及与肠道菌群间的相互作用对食源性致病菌的控制和预防具有十分重要的意义。人工模拟胃肠道模型基于人体胃肠道的生理过程,在体外条件下模拟体内的消化吸收情况,可以部分或完全替代活体实验,是研究食源性致病菌异质性以及致病机理的一种重要工具。本文系统综述应用人工模拟胃肠道模型研究食源性致病菌在胃肠道中的耐受、耐药异质性,为研究食源性致病菌在人体胃肠道中的异质性提供理论参考,同时将其与食源性致病菌动物感染模型（体内胃肠道模型）进行比较,综合评价人工模拟胃肠道模型在食源性致病菌异质性研究中的应用,以期为构建更加全面、科学的食品安全风险评估体系提供一定指导。     

食源性致病菌污染估计中删失数据分析的研究进展

食源性致病菌污染水平的确定是开展微生物定量风险评估的重要前提,而删失数据的存在易造成对食品中致病菌整体污染水平的估计产生偏差。对检测过程中出现的删失数据进行分析研究已逐渐成为食源性致病菌定量建模工作的重要内容之一。本文对国内外相关研究进行综述,介绍了食源性致病菌污染检测中删失数据的分类,比较了替代法、参数估计法、非参数估计法和多重填补法这4 类常用分析方法,简述了不同特征的致病菌污染检测数据集及相关统计学方法在食源性致病菌污染水平估计中的应用。最后,基于目前食源性致病菌污染水平估计中存在的问题进行探讨,指出降低估计结果不确定性的同时不可忽视检测数据的变异性,并对未来的风险监测、风险评估及风险交流相关研究作出展望。     

猪肉及其制品中非伤寒沙门菌定量风险评估研究进展

非伤寒沙门菌是全球重要的食源性致病菌之一,主要通过污染的畜禽食品感染人类。本文综述了国外猪肉及其制品中非伤寒沙门菌定量风险评估研究现状,重点解析常用模型,并分析我国猪肉中非伤寒沙门菌定量风险评估目前存在的挑战,以期为进一步开展相关风险评估提供参考依据。     

中国食品微生物风险评估进展与展望

食品微生物风险评估一直是国际上食品安全研究的热点。食源性致病菌引起的食品安全风险是全球性问题,发展中国家面临的情况更为严峻,我国政府高度重视食品安全工作,不断加强风险分析体系能力建设。从2010年以来,国家食品安全调查数据提示致病微生物导致的食物中毒事件的报告数一直高于化学性危害和有毒动植物造成的危害。因此加强我国微生物定量风险评估以减少与发达国家的差距,从国家层面上势在必行。     

国内外生鲜牛肉食源性致病微生物标准限量比较研究

论述了我国生鲜牛肉中主要食源性致病微生物的危害及污染状况,指出我国生鲜牛肉存在着被各种食源性致病菌污染的情况和风险。通过对国外一些国家的食源性致病微生物限量标准进行比较分析,指出我国生鲜牛肉食源性致病微生物限量标准与国际标准存在一定的差距,以及我国建立生鲜牛肉食源性致病微生物限量标准的重要性和紧迫性,并对我国生鲜牛肉微生物限量标准制定提出几点建议和意见。     

肉制品加工过程中食源性致病菌交叉污染及风险评估的研究进展

肉制品加工过程中食源性致病菌容易在食物接触表面和机器设备表面发生交叉污染,导致成品存在食用风 险。国内外已有研究者采用风险评估手段评估肉制品的食用风险。本文针对2000年至今已有的肉制品加工过程中食 源性致病菌交叉污染及其模型应用研究进行了综述,介绍了肉制品加工过程中食源性致病菌的交叉污染现状和因交 叉污染导致的食源性疾病现状,简述了部分加工过程的交叉污染模型及其在风险评估领域的应用,同时对目前香肠 类和火腿类两类肉制品现有的风险评估研究进行概括,最后对将来开展肉制品加工过程中交叉污染研究和定量风险 评估提出建议和思考。建议加强肉制品加工过程中交叉污染建模研究,增强风险评估与风险管理的互动交流,完善 肉制品加工过程的风险监测,进而开展更多系统性的肉制品加工过程定量风险评估研究。     

食源性致病菌定量风险评估的实例

定量风险评估是对桌种危害造成的风险的性质和严重程度的技术评估将这门新学科应用于食源性致病菌的研究,有利于推动风险管理与风险交流。介绍了沙门菌属、弧菌属、单核细胞增生性李斯特菌、大肠埃希菌O157：H7、弯曲菌属、腊样芽孢杆菌和阪崎肠杆菌等几种重要食源性致病菌定量风险评估的应用实例。     

餐饮食品及餐饮具食源性致病菌监测结果与分析

对餐饮食品及餐饮具食源性致病菌监测的目的是监测酒店餐饮食品和餐饮具的食源性致病菌污染状况,预测可能存在的食品安全风险,保障酒店食客的饮食安全。选取酒店作为监测对象,对酒店餐饮食品和餐饮具采样检测,检测指标包括6种常见食源性致病菌。结果显示:酒店餐饮食品和餐饮具存在一定程度致病菌污染风险。结论:食源性致病菌污染存在一定风险,建议政府部门加强风险管理和风险评估研究工作,预防和控制酒店餐饮食品安全风险。     

预测食品微生物学在肉品安全领域的应用

预测食品微生物学是一门对食品微生物进行数量化预测的新兴学科,可以在不进行传统微生物检测的条件下快速对食品的安全性和货架期进行预测。本文简述了预测食品微生物学的概念,模型分类及建模步骤,重点介绍了预测食品微生物学在肉品安全中的定量微生物风险评估、危害分析和关键控制点以及产品货架期等领域的应用,并对其未来发展进行了展望。     

Risk based microbiological criteria for Campylobacter in broiler meat in the European Union

Quantitative microbiological risk assessment (QMRA) allows evaluating the public health impact of food safety targets to support the control of foodborne pathogens. We estimate the risk reduction of setting microbiological criteria (MCs) for Campylobacter on broiler meat in 25 European countries, applying quantitative data from the 2008 EU baseline survey. We demonstrate that risk based MCs can be derived without explicit consideration of Food Safety Objectives or Performance Objectives. Published QMRA models for the consumer phase and dose response provide a relation between Campylobacter concentration on skin samples and the attending probability of illness for the consumer. Probabilistic modelling is used to evaluate a set of potential MCs. We present the percentage of batches not complying with the potential criteria, in relation to the risk reduction attending totally efficient treatment of these batches. We find different risk estimates and different impacts of MCs in different countries, which offers a practical and flexible tool for risk managers to select the most appropriate MC by weighing the costs (i.e. non-compliant batches) and the benefits (i.e. reduction in public health risk). Our analyses show that the estimated percentage of batches not complying with the MC is better correlated with the risk estimate than surrogate risk measures like the flock prevalence or the arithmetic mean concentration of bacteria on carcasses, and would therefore be a good measure for the risk of Campylobacter on broiler meat in a particular country. Two uncertain parameters in the model are the ratio of within- and between-flock variances in concentrations, and the transition factor of skin sample concentrations to concentrations on the meat. Sensitivity analyses show that these parameters have a considerable effect on our results, but the impact of their uncertainty is small compared to that of the parameters defining the Microbiological Criterion and the concentration on the meat.     

Risk assessment of biological hazards in the European Union

International, community and national food safety law and any subsequent decision-making practices aim to be based on risk analysis--a process consisting of risk assessment, risk management and risk communication. With the appointment of the European Food Safety Authority as an independent scientific point of reference in risk assessment, there is a clear functional separation between risk assessment and risk management in the European Union food safety context. When a food safety question on microbiological hazards is to be answered--which is under the remit of the EFSA's Scientific Panel on Biological Hazards (BIOHAZ)--extensive dialogue and interactions covering the clarity of the question, the acceptability of the deadline and the availability of all necessary information take place with both the risk managers who ask the question and the stakeholders. During the first mandate of the BIOHAZ Panel (2003-2006), the scientific opinions were mainly based on qualitative and in some cases semi-quantitative microbiological risk assessment. In the second mandate of the BIOHAZ Panel, and as a first step towards developing a European approach on Quantitative Microbiological Risk Assessment (QMRA), EFSA is preparing to carry out a QMRA on Salmonella in pigs, at European level through a consortium of European institutes.     

我国食品微生物风险评估的进展和挑战

近10余年来,我国依照《食品安全法》开展包括微生物风险评估在内的食品安全风险评估体系建设,微生物风险评估工作体系和技术体系等方面取得明显进展,成为我国开展食源性致病微生物风险评估的重要基础。随着全球后疫情时代食品供应链的变化和新技术的快速发展以及我国食品安全治理现代化需求的增加,构建基于我国膳食消费行为的评估模型、提高风险评估实施能力和质量以及实现现代技术在风险评估中的应用,将成为我国食品微生物风险评估建设的主要挑战和发展方向。     

Challenges in Risk Assessment: Quantitative Risk Assessment

The process of risk analysis consists out of three components, risk assessment, risk management and risk communication. These components are internationally well spread by Codex Alimentarius Commission as being the basis for setting science based standards, criteria on food safety hazards, e.g. setting maximum limits of mycotoxins in foodstuffs. However, the technical component risk assessment is hard to elaborate and to understand. Key in a risk assessment is the translation of biological or chemical pathways into a mathematical framework. Within the International Training Program ‘ITP food safety, quality assurance and risk analysis’ of Ghent University, department of Food Safety and Food Quality, we developed for low and middle income countries and emerging countries a training module on risk assessment. In where (semi-) quantitative probabilistic risk assessment calculations or qualitative risk rankings are trained for both microbial and chemical food safety hazards along the agro-food chain. This presentation will explain these methodologies demonstrated with examples from former ITP trainees.     

Fine-tuning Food Safety Objectives and risk assessment

Food Safety Objectives (FSOs) have been proposed as a practical tool to translate public health targets for food safety into tolerable levels of pathogens in a food product. The FSO concept is subject to intensive debate, and has not been developed in detail. We evaluate the proposed definition of FSOs and their implementation from the perspective of Quantitative Microbiological Risk Assessment (QMRA). The relationship between QMRA and FSOs is illustrated by a model for the public health risk of Shiga-producing Escherichia coli in steak tartare. We conclude that the proposed definition of FSOs needs to be modified to properly account for variability in and uncertainty about the contamination of food with pathogenic microorganisms and emphasize that both prevalence and concentration of pathogens must be considered. For this purpose, we propose the P-D equivalence curve, a simple graphical tool to separate "tolerable" from "non-tolerable" combinations of prevalence and concentration (dose).     

中国食品安全的过去、现在和将来

本文从国家食品安全管理体制、食品安全国家标准以及风险分析框架的应用三个方面来回顾中国的食品安全,并展望将来。中国的国家食品安全管理体制从单一部门管理为主,演变为多部门的分段管理,又发展为市场监管总局、海关总署和农业农村部为主。法律层面也从《食品卫生法》发展为遵循风险分析框架的新《食品安全法》(2015年10月实施)。中国的食品安全国家标准也从食品卫生标准发展为食品安全标准,从互不协调、相互矛盾的三套强制性国家标准整合为一套食品安全国家标准,在覆盖面、技术水平、实用性,以及与国际标准接轨方面,都取得了长足的进步。对于国际公认的风险分析框架,从缺乏认识,到增加理解和认真实施,在全面开展风险监测、建立适合国情的风险评估制度、加强风险交流等方面取得了突出的成绩和进步。然而,也应该清醒地看到,中国当前在食品安全方面还存在很多问题。食源性疾病的监测和控制还比较薄弱,食品掺假或欺诈还相当普遍,风险交流面临严峻挑战(消费者对食品安全的过度担心)。为了尽快提升中国食品的质量和安全性,一是要做到从农田到餐桌的全产业链食品安全保障,二是政府要做到全产业链的一体化无缝监管。     

Modelling bacterial growth in quantitative microbiological risk assessment: is it possible?

Quantitative microbiological risk assessment (QMRA), predictive modelling and HACCP may be used as tools to increase food safety and can be integrated fruitfully for many purposes. However, when QMRA is applied for public health issues like the evaluation of the status of public health, existing predictive models may not be suited to model bacterial growth. In this context, precise quantification of risks is more important than in the context of food manufacturing alone. In this paper, the modular process risk model (MPRM) is briefly introduced as a QMRA modelling framework. This framework can be used to model the transmission of pathogens through any food pathway, by assigning one of six basic processes (modules) to each of the processing steps. Bacterial growth is one of these basic processes. For QMRA, models of bacterial growth need to be expressed in terms of probability, for example to predict the probability that a critical concentration is reached within a certain amount of time. In contrast, available predictive models are developed and validated to produce point estimates of population sizes and therefore do not fit with this requirement. Recent experience from a European risk assessment project is discussed to illustrate some of the problems that may arise when predictive growth models are used in QMRA. It is suggested that a new type of predictive models needs to be developed that incorporates modelling of variability and uncertainty in growth.