金黄色葡萄球菌生物被膜的控制方法研究进展

金黄色葡萄球菌是一种重要的食源性病原菌.金黄色葡萄球菌能够形成生物被膜,使其更加难于根除.文中对金黄色葡萄球菌生物被膜的控制方法进行了全面综述,包括去除已形成的生物被膜、杀灭生物被膜中的金黄色葡萄球菌和抑制生物被膜的形成3个主要方面,旨在为食品工业领域生物被膜的控制提供借鉴.     

食品工业中生物被膜的形成及其控制

生物被膜对食品工业的危害极大,可使微生物残存增加,加工设备无法严格清洗、消毒,产品受到污染。本章综述了食品加工过程中生物被膜的形成特点及其控制方法,并对近几年生物被膜的检测方法进行了介绍。     

405 nm LED处理对不锈钢片表面金黄色葡萄球菌生物被膜的清除作用

该研究探究了405-nm LED(light-emitting diode)对不锈钢片表面金黄色葡萄球菌生物被膜的清除作用。首先测定了405-nm LED对不锈钢表面金黄色葡萄球菌生物被膜中活菌的灭活效果,随后通过分析405-nmLED处理后金黄色葡萄球菌生物被膜对消毒剂的耐受性、生物被膜化学成分以及生物被膜微观结构的变化研究405-nm LED对不锈钢表面金黄色葡萄球菌生物被膜可能的清除机理。结果表明,405-nm LED处理能够显著降低生物被膜内的活菌量:在4、10和25℃下使用LED处理4 h后,活菌量与对照组相比分别降低了2.03、2.08和3.00 log CFU/cm²;405-nm LED处理还降低了处理后的生物被膜细胞对消毒剂的耐受性;破坏了生物被膜立体构象的完整性和立体结构;降低了生物被膜主要组分的含量(胞外多糖和胞外蛋白质)。以上研究结果表明,405-nmLED可以有效清除不锈钢片表面的金黄色葡萄球菌生物被膜,其有潜力进一步开发作为新型生物被膜清除方法用于控制金黄色葡萄球菌生物被膜的污染。     

单核增生李斯特氏菌生物被膜的形成及控制

研究温度、接种量对单核增生李斯特氏菌(Listeri amonocytogenes)生物被膜形成的影响和肉制品加工企业中常用的消毒方法对单增李斯特氏菌生物被膜的去除及抑制作用.研究结果表明,单核增生李斯特氏菌标准菌株生物被膜的形成主要受到温度的影响,接种量对生物被膜形成的影响只在特定的温度范围内显著.以不同的常规消毒方法对模拟生产车间条件培养生长1d的单增李斯特氏菌生物被膜进行处理,结果发现不同方法对生物被膜去除效果的差异性随着处理天数的增加而增加,且各方法对生物被膜的去除作用与抑制作用无关.     

金黄色葡萄球菌生物被膜检测及控制方法研究进展

金黄色葡萄球菌极易在食品的加工、储存过程中形成生物被膜,使得被膜内的细菌很难被清除,给食品安全带来了巨大隐患。综述了金黄色葡萄球菌生物被膜的形成、检测、控制方法和影响因素,特别是针对国内外金黄色葡萄球菌生物被膜的检测及物理、化学和生物等控制方法进行了详述,旨在为食品工业领域生物被膜的消除提供借鉴。     

食品接触表面生物被膜形成机制及防控方法研究进展

食源性致病菌的生物被膜是固着在食品接触表面上形成的具有一定空间组织的多细胞群体结构。因生物被膜具有极强的黏附性和抗逆性,常规消杀手段难以对其进行有效防控,造成食品安全隐患并严重威胁消费者身体健康。本文归纳了近年来国内外食源性致病菌生物被膜在形成机制及防控方法方面的相关研究。以生物被膜黏附性提高、菌体状态改变和抗逆性增强的3个主要特点为核心,总结讨论了细菌的长链附属结构、群体感应系统及胞外聚合物在生物被膜的形成过程中的作用,并将生物被膜的防控策略分为物理、化学和生物法3类,分别分析了各类方法的作用原理及优缺点,旨在为食品领域生物被膜的高效防控方法的开发提供理论指导,以期更好地实现食品微生物的安全有效防控。     

金银花和蒲公英提取物对肉源性假单胞菌生物被膜的清除作用

为明确金银花和蒲公英提取物对假单胞菌生物被膜的清除效果,采用单因素实验确定假单胞菌生物被膜的最佳培养温度、培养时间和固定方法;在此条件下,采用结晶紫法结合扫描电镜研究金银花和蒲公英提取物在不同质量浓度、不同添加时间下对肉源性假单胞菌生物被膜的清除作用。结果表明,30 ℃培养24 h生物被膜测定值最高。提取物对生物被膜的清除效果随质量浓度的增加而逐渐增强(P<0.05),在生物被膜形成0 h加入的清除效果显著强于在24 h加入的清除效果(P<0.05)。当提取物浓度高于最小抑菌浓度(MIC)时,主要通过抑制菌体生长而清除生物被膜;当低于最小抑菌浓度时,主要通过破坏生物被膜立体结构而清除生物被膜。提取物破坏假单胞菌生物被膜结构,使生物被膜形成孔洞,从而清除生物被膜。本研究证明金银花和蒲公英提取物能够清除假单胞菌生物被膜,对肉的保鲜具有潜在应用价值。     

细菌生物被膜检测与清除方法研究进展

开展食源性致病菌的防控研究以保障食品安全,具有显著的实践意义。作为细菌为适应不良环境所表现出的一种自我保护机制,食源性致病菌在食品生产加工过程中,可以黏附在食品原材料表面以及各种食品加工器械表面形成生物被膜,增大了消毒清洗的难度,给食品安全带来了严重的隐患和危害。因此,如何有效地清除细菌生物被膜成为食品安全领域的研究热点。结合细菌生物被膜形成过程和调控机制,本研究系统分析总结了细菌生物被膜的检测与清除方法的现状,为实现细菌生物被膜的有效控制,消除由生物被膜造成的食品安全隐患提供了综合性的认识,可为研究人员解决细菌生物被膜带来的食源性微生物污染提供参考,对保障食品安全有重要意义。     

水产品中微生物生物被膜形成机制与控制方法研究进展

生物被膜(biofilm,BF)是细菌在其生长过程中形成一种非游离状态的微生物细胞集合体,属特定的群体结构。该文根据近年来微生物生物被膜的研究现状,介绍了微生物生物被膜的形成过程,系统阐述了生鲜与冷冻水产品中的微生物生物被膜现象,通过对当前生物被膜的物理法、化学法与化学生物法等控制措施予以说明,提出存在问题与解决办法,并对微生物生物被膜控制技术的发展趋势予以展望。     

铜绿假单胞菌基因型与生物被膜形成能力的分析

通过改良的组织平板培养法及ERIC-PCR方法对48株PA生物被膜的形成进行定量分析并绘制其指纹图谱。结果发现48株PA菌株生物被膜形成能力不同,且在17%相似水平上分为A、B、C、D、E五个基因型,其中生物被膜形成能力较弱的菌株大多属于前三个基因型,而D和E基因型则包含了大部分生物被膜形成能力较强的菌株,这表明不同生物被膜形成能力的PA在5个基因型中的分布并非随机的,菌株生物被膜形成能力和基因型之间具有一定的相关性。     

生物膜的形成与控制

生物膜对食品加工厂的危害极大，可能使微生物残存率增加，造成食品加工车间地坪、设备无法适当清洗、清毒，引起产品受到污染。食品加工厂欲控制生物膜的形成，应从设计、生产环节着手，严格控制微生物生物膜的形成。     

Biofilm formation by salmonella spp. on food contact surfaces and their sensitivity to sanitizers

Biofilm formation by two poultry isolates of Salmonella on three commonly used food contact surfaces viz plastic, cement and stainless steel were studied. Biofilm formation of both the isolates showed a similar trend with the highest density being on plastic followed by cement and steel. Salmonella weltevreden formed biofilm with a cell density of 3.4 x 10(7), 1.57 x 10(6) and 3 x 10(5) cfu/cm2 on plastic, cement and steel respectively while Salmonella FCM 40 biofilm on plastic, cement and steel were of the order of 1.2 x 10(7), 4.96 x 10(6) and 2.23 x 10(5) cfu/cm2 respectively. The sensitivity of the biofilm cells grown on these surfaces to different levels of two sanitizers namely hypochlorite and iodophor for varying exposure times was studied. Biofilm cells offered greater resistance when compared to their planktonic counterparts. Such biofilm cells in a food processing unit are not usually removed by the normal cleaning procedure and therefore could be a source of contamination of foods coming in contact with such surfaces.     

食品加工过程中细菌生物被膜的危害及控制

生物被膜中的微生物生活在一个由胞外聚合物（EPS）形成的环境中,它的形成是微生物生长过程中的一个保护模式,允许细胞在恶劣的环境中生存并分散到新的环境中。食品加工过程中有害菌形成的生物被膜对食品工业的危害极大,可使微生物残存增加,加工设备无法严格清洗、消毒,导致产品受到污染。该文在收集、研究现有文献的基础上归纳介绍了生物被膜的特点及其形成过程和形成机制,概述了生物被膜的危害、控制及检测方法,旨在提高人们对生物被膜的认识,推动该领域的研究发展。     

从腐败食品中分离的乳酸菌生物被膜形成的影响因素

从腐败的蔬菜和肉质食品中分离筛选乳酸菌(LAB),并以其作为研究对象,对乳酸菌生物成膜不同影响因素进行研究。生化分离鉴定乳酸菌,在不同的营养物质浓度及培养条件下,用96孔板法检测乳酸菌成膜。在无外添加物,37℃和42℃的培养温度,pH4有利于乳酸菌生物膜的形成,低温不利于生物膜的形成。低浓度的NaCl可促进LAB形成生物膜,但高于某浓度,就抑制LAB成膜。不同LAB菌株对不同葡萄糖浓度成膜效果不同,且与温度交互作用。结果表明,腐败食品中乳酸菌具有一定的生物被膜形成能力,控制乳酸菌生物膜的形成对于防治食品的腐败变质具有一定的意义。     

Promising strategies to control persistent enemies: Some new technologies to combat biofilm in the food industry—A review

Biofilm is an advanced form of protection that allows bacterial cells to withstand adverse environmental conditions. The complex structure of biofilm results from genetic-related mechanisms besides other factors such as bacterial morphology or substratum properties. Inhibition of biofilm formation of harmful bacteria (spoilage and pathogenic bacteria) is a critical task in the food industry because of the enhanced resistance of biofilm bacteria to stress, such as cleaning and disinfection methods traditionally used in food processing plants, and the increased food safety risks threatening consumer health caused by recurrent contamination and rapid deterioration of food by biofilm cells. Therefore, it is urgent to find methods and strategies for effectively combating bacterial biofilm formation and eradicating mature biofilms. Innovative and promising approaches to control bacteria and their biofilms are emerging. These new approaches range from methods based on natural ingredients to the use of nanoparticles. This literature review aims to describe the efficacy of these strategies and provide an overview of recent promising biofilm control technologies in the food processing sector.     

生物膜的形成与控制

生物膜对食品工厂的危害极大,可使微生物残存增加,加工车间设备无法适当清洗、清毒;产品受到污染,甚至危害产品的安全。食品加工厂欲控制生物膜的形成,应从设计、生产环节着手,设计出良好的生产环境,注意清洗频率,使用正确的清洗、消毒方法,严格控制生物膜的形成,才能保障产品的卫生安全。     

Biofilm Formation and Control in Food Processing Facilities

Microorganisms on wet surfaces have the ability to aggregate, grow into microcolonies, and produce biofilm. Growth of biofilms in food processing environments leads to increased opportunity for microbial contamination of the processed product. These biofilms may contain spoilage and pathogenic microorganisms. Microorganisms within biofilms are protected from sanitizers increasing the likelihood of survival and subsequent contamination of food. This increases the risk of reduced shelf life and disease transmission. Extracellular polymeric substances associated with biofilm that are not removed by cleaning provide attachment sites for microorganisms newly arrived to the cleaned system. Biofilm formation can also cause the impairment of heat transfer and corrosion to metal surfaces. Some of the methods used to control biofilm formation include mechanical and manual cleaning, chemical cleaning and sanitation, and application of hot water.     

Biofilm formation by Escherichia coli in hypertonic sucrose media

High osmotic environments produced by NaCl or sucrose have been used as reliable and traditional methods of food preservation. We tested, Escherichia coli as an indicator of food-contaminating bacterium, to determine if it can form biofilm in a hyperosmotic environment. E. coli K-12 IAM1264 did not form biofilm in LB broth that contained 1 M NaCl. However, the bacterium formed biofilm in LB broth that contained 1 M sucrose, although the planktonic growth was greatly suppressed. The biofilm, formed on solid surfaces, such as titer-plate well walls and glass slides, solely around the air–liquid interface. Both biofilm forming cells and planktonic cells in the hypertonic medium adopted a characteristic, fat and filamentous morphology with no FtsZ rings, which are a prerequisite for septum formation. Biofilm forming cells were found to be alive based on propidium iodide staining. The presence of 1 M sucrose in the food environment is not sufficient to prevent biofilm formation by E. coli.     

生物膜状态对食源性致病菌耐药与毒力的影响研究进展

生物膜是细菌抵御不利环境维持群体稳定性的一种常见的群落形态。生物膜状态增强了食源性致病菌的抗逆性和持久存活力,促进了细菌间的信息传导和物质交换。特别是生物膜状态显著增强了菌株对抗生素的耐受能力,提升了可移动元件在细菌间的转移效率,并且生物膜状态下的细菌具备更强的入侵和感染能力,成为食品安全和人类健康的重要危害。基于此,本文将从生物膜的结构特征与异质性、生物膜对基因突变和基因水平转移的影响、以及群体感应调控等多个角度,简述生物膜状态影响食源性致病菌耐药和毒力的研究进展,以期为深入研究生物膜的生物功能与危害防控提供新的思路。     

Variability in biofilm production by Listeria monocytogenes correlated to strain origin and growth conditions

This study aimed to identify factors that influence the development of biofilm by Listeria monocytogenes strains and to determine the extent to which biofilm production protects against quaternary ammonium compound (QAC) disinfectant challenge. A total of 95 L. monocytogenes strains were studied and biofilm production was assessed as a function of incubation temperature, media pH, strain origin, serotype, and environmental persistence status. Attachment and biofilm development (inferred by the level of attached biomass) were measured in vitro using a colourimetric 96-well microtitre plate method in nutritive media (Brain-Heart Infusion). Increased biofilm production correlated with increasing temperature and the most acidic, or most alkaline, growth conditions tested. Clinical and environmental (food factory) strains were observed to increase biofilm production at higher and lower incubation temperatures respectively, independent of their rate of planktonic growth. Serotype 1/2a strains produced significantly more biofilm. Biofilm maturity, rather than strain, was correlated with resistance to QAC. Carbohydrate containing exopolymeric material could not be detected in the biofilm of representative strains, and no correlation between strains recovered as persistent food factory contaminants and biofilm production was identified. Although limited to in vitro inference based on the assay system used, our results suggest that environmental conditions determine the level of biofilm production by L. monocytogenes strains, independent of the rate of planktonic growth, and that this may manifest from selection pressures to which a given strain grows optimally.