食源性致病菌生长延滞期建模的研究进展

基于预测微生物学理论,准确预测食源性致病菌的数量及生长对降低食品安全风险具有重大意义。本文针对近年来国内外食源性致病菌生长延滞期的建模工作,从食源性致病菌延滞期的测定方法和建模方法两方面进行综述。通过分析现有延滞期建模的相关研究,指出目前延滞期建模研究中存在的问题。建议未来应基于微生物生长机理明确延滞期定义,进一步根据延滞期定义改进、创新延滞期测定方法及建模方法,同时量化分析延滞期影响因素并整合延滞期建模。     

质粒介导的氨苄西林耐药肠炎沙门氏菌生长特性及抗性研究

肠炎沙门氏菌是一种重要食源性致病菌，其耐药性成为全球关注的问题。耐药质粒的广泛传播提高了肠炎沙门氏菌的耐药性，耐药质粒的获得可能会改变细菌的生长特性及对环境压力的抗性，这给耐药食源性致病菌的控制及风险评估带来了新的挑战。为探究质粒介导的氨苄西林耐药性对肠炎沙门氏菌生长以及抗性变化的影响，该研究将含有氨苄西林抗性基因的pKD46质粒导入到抗生素敏感的肠炎沙门氏菌中，获得氨苄西林耐药菌株。分别对转化后的耐药沙门氏菌的生长特性、酸与热抗性进行检测。结果发现耐药质粒转化后的肠炎沙门氏菌菌株对其他种类抗生素的抗性基本不变；生长的最大比生长速率(μ_max)不变，生长延滞期(λ)延长；在57.5与60℃条件下的热抗性显著降低；对pH 3.0的酸抗性未发生显著改变。研究结果发现质粒介导的氨苄西林耐药性可降低肠炎沙门氏菌的生长及热抗性，该结果可为耐药食源性致病菌的控制及风险评估提供参考。     

食源性致病菌生长异质性对风险评估的影响

文章介绍了食源性致病菌生长异质性的概念,概述了国内外相关领域的研究进展,系统综述了菌株生长异质性的表现形式以及影响因素,总结归纳了降低食源性致病菌生长异质性对微生物风险评估结果准确性的解决方法。     

表面增强拉曼光谱在食源性致病菌检测中的应用研究进展

食源性致病菌引起的食品安全是影响公共卫生和人类健康的重要因素,因此如何高效、便捷地检测食品中的致病菌是食品行业关注的焦点。表面增强拉曼光谱（surface enhanced Raman spectroscopy,SERS）可直接或间接识别致病菌的“指纹”信息,在食源性致病菌检测中的应用前景广阔。该文总结SERS的发展、增强机制、基底类别及其在食源性致病菌检测中的应用,在提出其局限性的同时对未来发展趋势进行展望。     

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。     

滚环等温扩增技术在食源性致病菌检测中的应用

食源性致病菌是影响人类食品安全的重要因素.人类食源性致病菌致病率的逐年上升,引起世界广泛关注.滚环等温扩增(rolling circle amplification,RCA)技术因具有高特异性、高灵敏度、稳定、操作简单等优点,在食源性致病菌检测中具有广泛的应用前景.近年来以滚环等温扩增技术为基础,针对食源性致病菌的检测...     

食源性致病菌耐药性与成簇的规律间隔短回文重复序列系统关联性研究进展

近年来,随着对抗生素的滥用,导致了食源性致病菌的耐药性问题日趋严重。目前除了从管理上规范抗生素的使用,对CRISPR与耐药性相关研究也在持续进行。CRISPR-Cas作为一种天然免疫机制,因为其独特的免疫作用机理,目前常被用以基因编辑、耐药性等方面研究。本文对CRISPR-Cas系统进行初步介绍,从其结构、原理以及目前的研究趋势对不同菌株间CRISPR系统与耐药性、毒力因素进行相关研究,有利于更好地提供耐药机制,为防治食源性致病菌引起的食品安全问题提供新思路。     

食源性致病菌生物被膜的形成及危害研究进展

在食品加工过程中,食源性致病菌常常以生物被膜（Biofilm,BF）的生长形态存活在食品或加工器械表面,使其具有更强的致病性、感染性和耐药性,从而引发潜在的食品安全问题,威胁人类健康。本文系统阐述了食源性致病菌BF形成的3个阶段,即黏附阶段（包括可逆黏附和不可逆黏附）、成熟阶段、解体与传播阶段。此外,本文总结了食源性致病菌BF对食品的危害,旨在为食源性致病菌BF的相关研究提供一定的理论参考,对食品工业的安全发展具有重要的意义。     

纳米材料在食源性致病菌检测的研究进展

摘 要:食品安全问题已经成为全球研究热点问题之一,其中由食源性致病菌引起的食源性疾病频发,对公众健康和财产造成重大的影响。近年来,人们的食品安全意识呈显著增强趋势,食源性致病菌引起的食品安全问题引起了广泛关注。纳米材料具有高灵敏度、高选择性、便携性和低成本等优点,越来越广泛地应用于食源性致病菌的检测,逐渐能够取代传统的检测方式。因此,本文结合近些年国内外的纳米材料在食源性致病菌检测中的研究,综述了不同类型的纳米材料用于检测食源性致病菌的检测原理及其应用。此外,本文讨论了该领域中的研究挑战和前景,以期为今后食品安全提供保障,及时发现不合格、不健康、不安全的食品中的食源性致病菌。     

免疫层析试纸条技术及其在食源性致病菌检测中应用的研究进展

食源性致病菌是引起食物中毒的最主要原因之一,全球每年由其引发的食物中毒事件达上亿例。免疫层析试纸条法是一种简便、快速且价格低廉的检测方法,广泛应用于国内基层单位对食源性致病菌现场快速检测及诊断。本文就其在食源性致病菌检测方面的研究现状及发展方向进行综述。     

Microbial risk assessment: dose-response relations and risk characterization

Characterizations of the risks associated with foodborne pathogens are dependent on the availability of information on the population's exposure to the biological agents. However, by itself, exposure data are insufficient to assess the public health impact of pathogenic microorganisms. This requires the availability of effective dose-response models. Successful development of models that describe dose-response relations for enteric pathogens is dependent on a sound understanding of the mechanisms of pathogenicity associated with individual pathogens. This includes knowledge of how the various pathogen, host, and food matrix factors influence pathogenicity. Currently, a group of sigmoidal mathematical equations are used to empirically describe dose-response relations. While these have proven to be highly useful, advances in microbial food safety risk assessment will likely require the development of mechanistic models that more effectively consider the range of factors that influence the frequency and severity of foodborne infections in a population.     

Clostridium botulinum in the post-genomic era

Foodborne botulism is a severe neuroparalytic disease caused by consumption of botulinum neurotoxin formed by strains of proteolytic Clostridium botulinum and non-proteolytic C. botulinum during their growth in food. The botulinum neurotoxin is the most potent substance known, with as little as 30-100 ng potentially fatal, and consumption of just a few milligrams of neurotoxin-containing food is likely to be sufficient to cause illness and potentially death. In order to minimise the foodborne botulism hazard, it is necessary to extend understanding of the biology of these bacteria. This process has been recently advanced by genome sequencing and subsequent analysis. In addition to neurotoxin formation, endospore formation is also critical to the success of proteolytic C. botulinum and non-proteolytic C. botulinum as foodborne pathogens. The endospores are highly resistant, and enable survival of adverse treatments such as heating. To better control the botulinum neurotoxin-forming clostridia, it is important to understand spore resistance mechanisms, and the physiological processes involved in germination and lag phase during recovery from this dormant state.     

多重荧光PCR快速检测食源性致病菌的研究进展

食源性疾病多由食源性致病菌引发,威胁个人健康及全球食品安全,因此寻找有效、可靠的食源性致病菌高通量检测方法对于确保食品安全具有重要意义。鉴于传统检测技术耗时长、效率低等问题,PCR等分子生物学技术应用于食用致病菌检测领域越来越广泛,本文在普及食用性致病菌知识的基础上,着重对多重荧光PCR技术原理及在食用性致病菌检测的应用进展进行综述,以期为控制由食用性致病菌引发的食品安全隐患提供理论参考。     

SHELF-LIFE EXTENSION AND SAFETY CONCERNS ABOUT FRESH FISHERY PRODUCTS PACKAGED UNDER MODIFIED ATMOSPHERES: A REVIEW

Shelf-life and quality of fresh fishery products can be extended by the use of a modified atmosphere (MA) and high barrier film packaging coupled with refrigerated storage. MAs with elevated levels of carbon dioxide inhibit or slow the growth of various aerobic spoilage bacteria of fishery products by extending the lag phase. However, at the same time, MAs provide conditions for the growth of Grampositive bacteria and food pathogens within the package. The extension of the storage life of the refrigerated MA products may enable the slower-growing Gram-positive bacteria to reach high populations. The shelf-life of fishery products packaged under MAs rich in carbon dioxide coupled with storage at 8.0°C or below can be extended more than 100%. Major safety concerns regarding the risk of foodborne botulism can result from MA packaging of fresh fishery products that contain the spores of nonproteolytic C. botulinum and are subsequently temperature-abused. Minimizing the risk of foodborne botulism by including inhibitory factors such as antimicrobial agents before packaging fishery products under MAs and strict adherence to refrigerated storage temperatures are discussed.     

Emerging foodborne pathogens

The broad spectrum of foodborne infections has changed dramatically over time, as well-established pathogens have been controlled or eliminated, and new ones have emerged. The burden of foodborne disease remains substantial: one in four Americans is estimated to have a significant foodborne illness each year. The majority of these illnesses are not accounted for by known pathogens, so more must remain to be discovered. Among the known foodborne pathogens, those more recently identified predominate, suggesting that as more and more is learned about pathogens, they come under control. In addition to the emergence or recognition of new pathogens, other trends include global pandemics of some foodborne pathogens, the emergence of antimicrobial resistance, the identification of pathogens that are highly opportunistic, affecting only the most high-risk subpopulations, and the increasing identification of large and dispersed outbreaks. New pathogens can emerge because of changing ecology or changing technology that connects a potential pathogen with the food chain. They also can emerge de novo by transfer of mobile virulence factors, often through bacteriophage. Though this is rarely observed, it can be reconstructed. Better understanding of the ecology and dynamics of phage transmission among bacteria will help us to understand the appearance of new pathogens in the future. One may look for emerging foodborne pathogens among the silent zoonoses, and among the severe infections affecting the immunocompromised humans. We should expect the unexpected. In the past, separating human sewage and animal manure from human food and water supplies was critical to improving public health. Now, our health depends increasingly on the safety of the feed and water supplies for the animals themselves. The successes of the 20th century and the new challenges we face mean that public health vigilance, careful investigation of new problems, responsible attention to food safety from farm to table, and partnerships to bring about new foodborne disease control measures will be needed for the foreseeable future.     

Antibacterial activity in extracts of Camellia japonica L. petals and its application to a model food system

The potential presence of naturally occurring antimicrobials in petals of Camellia japonica L., a member of the tea family, was investigated against foodborne pathogens in microbiological media and food. Petals of the camellia flower (C. japonica L.) were extracted with methanol and fractionated into basic, acidic, and neutral fractions. The acidic fraction (equivalent to 1.0 g of raw sample per disk) produced an inhibitory zone of 14 to 19 mm (diameter) in a disk assay against the pathogens Salmonella Typhimurium DT104, Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus on agar plates. Silica gel adsorption column chromatography, Sephadex LH-20 column chromatography, and preparative purification by high-pressure liquid chromatography were used to purify compounds in the fraction. The mass spectrum of the antibacterial compound isolated had a molecular ion (M+) of m/z 116 and showed good conformity with the spectrum of fumaric acid (HOOC-CH=CH-COOH). An aqueous extract from the petals of C. japonica L. had an inhibitory effect on growth of all pathogens at 37 degrees C in microbiological media by increasing the lag phase. None of the microorganisms was inhibited completely. Milk was used as a model food system. Aqueous extract at a concentration of 100 mg/ml was bacteriostatic against all the foodborne pathogens in the milk stored at 25 degrees C for up to 4 days.     

代谢组学在食品质量安全领域的应用进展

食品质量安全是保障现代经济社会和谐稳定发展的基础与前提，目前，食源性致病微生物、兽药残留、转基因食品及掺假等问题均会造成或可能造成食品安全隐患。代谢组学作为新兴技术不断发展，通过研究生物体受外界干扰前后小分子代谢产物的变化，进而探究机体内代谢机制，适用于食品安全多种微量危害因子的鉴别和监测。此外，危害因子在食品分解过程中产生的代谢物可成为特定的潜在生物标志物，为致病菌作用机制和品质安全控制的研究提供参考。本文阐述靶向代谢组学和非靶向代谢组学，介绍代谢组学技术常用的数据采集和数理统计方法，总结代谢组学技术在食源性致病菌、兽药残留、转基因食品、生鲜食品品质和肉制品掺假等食品品质和安全领域的研究进展，并对多组学联用技术提出展望，以期推动该技术在食品质量安全领域更广泛的应用。