某福利院一起肠炎沙门菌食源性疾病的调查分析

目的 对某福利院一起肠炎沙门菌食源性疾病进行调查和溯源,为研究相关食源性疾病提供参考。方法采用流行病学、食品卫生学和脉冲场凝胶电泳(PFGE)同源性分析等方法,分析本次食源性疾病事件。结果 确认本次事件中病例23名,患病率5.65%(23/407)；现场采集病例肛拭子15份和厨房工作人员肛拭子3份、留样菜品3份、水果2份以及冰棒1份,其中从11份病例肛拭子中检出肠炎沙门菌,PFGE结果显示11株肠炎沙门菌的DNA条带图谱相似性为96.4%,聚类分析为同一型,结合流行病学调查,初步判断菌株来自同一克隆系。结论 综合流行病学、食品卫生学和实验室检测结果,确定为一起肠炎沙门菌引起的食源性疾病,福利院应加强对特殊人群的饮食安全管理,制定相应的食源性疾病突发事件应急处理预案,防止此类事故再发生。     

Efficacy of thyme oil-alginate-based coating in reducing foodborne pathogens on fresh-cut apples

In this study, the inhibition of an alginate-based edible coating (EC) containing thyme oil (0.05%, 0.35% and 0.65%) was evaluated against Listeria monocytogenes, Salmonella Typhimurium, Staphylococcus aureus and Escherichia coli O157:H7 inoculated onto fresh-cut apples. To investigate the antibacterial mechanism of thyme oil, the constituent compounds of that were analysed by gas chromatography-mass spectrometry (GC-MS), and the cellular damage of pathogens was observed by scanning electron microscopy (SEM). Results showed that alginate-based EC containing thyme oil effectively inhibited the growth of pathogens on fresh-cut apples. GC-MS analysis revealed thymol (47.23%) as the major compounds in thyme oil. SEM showed that the cell membrane of foodborne pathogens was damaged by thyme oil, causing their inactivation. Treatment with alginate-based EC containing 0.05% thyme oil preserved the sensory characteristics of fresh-cut apples. Therefore, using alginate-based EC with thyme oil may represent a potential approach to preserve and enhance the safety of fresh-cut apples.     

Practical in-storage interventions to control foodborne pathogens on fresh produce

Although tremendous efforts have been made to ensure fresh produce safety, various foodborne outbreaks and recalls occur annually. Most of the current intervention strategies are evaluated within a short timeframe (less than 1 h), leaving the behavior of the remaining pathogens unknown during subsequent storages. This review summarized outbreak and recall surveillance data from 2009 to 2018 obtained from government agencies in the United States to identify major safety concerns associated with fresh produce, discussed the postharvest handling of fresh produce and the limitations of current antimicrobial interventions, and reviewed the intervention strategies that have the potential to be applied in each storage stage at the commercial scale. One long-term (up to 12 months) prepacking storage (apples, pears, citrus among others) and three short-term (up to 3 months) postpacking storages were identified. During the prepacking storage, continuous application of gaseous ozone at low doses (≤1 ppm) is a feasible option. Proper concentration, adequate circulation, as well as excess gas destruction and ventilation systems are essential to commercial application. At the postpacking storage stages, continuous inhibition can be achieved through controlled release of gaseous chlorine dioxide in packaging, antimicrobial edible coatings, and biocontrol agents. During commercialization, factors that need to be taken into consideration include physicochemical properties of antimicrobials, impacts on fresh produce quality and sensory attributes, recontamination and cross-contamination, cost, and feasibility of large-scale production. To improve fresh produce safety and quality during storage, the collaboration between researchers and the fresh produce industry needs to be improved.     

食用农产品中产志贺毒素大肠埃希菌污染与家庭厨房食物安全现状分析及防控措施

本文通过对食用农产品中产志贺毒素大肠埃希菌(STEC)来源与传播途径分析,阐述了STEC污染与家庭厨房食物安全之间的关系,并对当前世界各国食品中STEC的监管情况进行阐述,从而提出我国控制食用农产品中STEC进入家庭厨房的解决方案。     

乳品中食源性致病菌快速检测技术研究进展

近年来食源性疾病事件频发,食源性疾病已成为全球化的公共卫生问题,其中有害微生物污染占了较大比重,而乳品因营养丰富可以为众多微生物提供生长所需的营养物质易被其污染。传统的微生物检测方法虽然设备简单、成本低廉,但普遍检测周期长、操作繁琐,对人员操作水平和检验经验要求高。本文综述了分子生物学技术、免疫学技术、光谱技术、基质辅助激光解吸电离飞行时间质谱技术、生物传感器技术以及流式细胞技术在乳品食源性致病菌快速检测的研究进展,展望了乳品中食源性致病菌检测技术向在线化、便捷化、高效化发展前景,以期为后续研究提供参考和借鉴。     

Effect of processing on the microbiological quality and safety of chicken carcasses at slaughterhouse

Microbiological contamination of chicken meat depends on the conditions under which the animals are reared, slaughtered and processed. The aim of this study was to determine the influence of farm origin and processing stages at slaughterhouse on the microbial safety and quality of chicken. Samples of chicken carcasses from three different farms were taken from a slaughterhouse. Mesophiles, Escherichia coli, coagulase positive Staphylococcci counts, presence of Listeria monocytogenes,Campylobacter and Salmonella were determined at five sampling points: after defeathering, after evisceration, after washing, after chilling and after cutting. Chilling reduced log numbers of mesophiles, coagulase positive Staphylococci and E. coli by 0.85, 1.52 and 2.2 log units, respectively. Salmonella was not detected after chilling. High prevalence of Campylobacter spp was observed at all the stages ranging between 84% and 100%. L. monocytogenes was not detected in chicken carcasses after defeathering. However, it was detected after evisceration and after washing and chilling. The most critical stage for L. monocytogenes contamination was the portioning operation, the prevalence in breast and legs being 88% and 84%, respectively.     

陕西省某活鸡屠宰场肉鸡相关样品中沙门菌定量检测及污染分析

目的了解肉鸡屠宰加工中不同时间和环节沙门菌的污染情况,分析污染关键点。方法 2016年11月至2017年11月从陕西省某活鸡屠宰场不同环节定期采集活鸡肛拭子标本、整鸡胴体和鸡肉样品,使用最大可能数(MPN)法对沙门菌进行定量检测,同时分离菌株;采用聚合酶链式反应(PCR)技术对沙门菌进行鉴定,同时结合血清凝集技术对沙门菌鉴定结果进行确认。结果采集的284份样品中有67份检出沙门菌,检出率为23. 6%,平均MPN值为0. 051 6 MPN/g。2017年7月采集的样品沙门菌污染最为严重,检出率为37. 8%(14/37),平均MPN值为0. 064 7 MPN/g; 2016年11月检出率最低,为13. 9%(5/36),平均MPN值为0. 043 6 MPN/g。不同屠宰环节中,浸烫褪毛后整鸡胴体样品中沙门菌检出率最高(43. 3%,26/60),平均MPN值为0. 060 5 MPN/g;分割后冷冻前鸡胸脯肉样品中沙门菌检出率最低(18. 3%,11/60),平均MPN值为0. 036 8 MPN/g,略高于储存配送过程整鸡胴体/鸡胸脯肉样品中沙门菌的污染水平(0. 035 8 MPN/g)。结论活鸡屠宰过程沙门菌的检出率与MPN值具有较强的季节性,在不同屠宰加工环节存在纵向和交叉污染,应对活鸡屠宰加工过程沙门菌污染严重的环节进行重点控制。     

非热杀菌技术在低温鸡肉制品致病菌控制中的应用研究进展

由于低温鸡肉制品具有较好的感官品质，能够保留鸡肉原有的营养，成为我国肉制品发展的一个趋势。低温鸡肉制品水分含量和pH值较高，在加工和贮藏过程中极易受到食源性致病菌的污染，影响产品的质量安全，甚至引发食源性疾病，因此采用合适的杀菌技术来解决致病菌的污染是低温鸡肉制品贮藏保鲜需要解决的关键问题。由于热杀菌技术不适合用于低温鸡肉制品的灭菌，非热杀菌技术的应用就显得尤其重要。目前，应用在低温鸡肉制品加工中的非热杀菌技术主要包括超高压、辐照、超声、低温等离子体、脉冲紫外线、脉冲电场和脉冲微波。本文主要综述以上7 种非热杀菌技术的杀菌机制以及在不同低温鸡肉制品加工应用时对致病菌的控制效果，为未来非热杀菌技术在低温肉制品加工中的应用提供参考。