Strategies and novel technologies to control Campylobacter in the poultry chain: A review

Campylobacteriosis is one of the most common bacterial infections worldwide causing economic costs. The high prevalence of Campylobacter spp. in poultry meat is a result of several contamination and cross‐contamination sources through the production chain. Moreover, survival mechanisms, such as biofilm formation, viable but nonculturable state, and antimicrobial resistance, enable its persistence during food processing. Therefore, mitigation strategies are necessary in order to avoid and/or inactivate Campylobacter at farm, abattoir, industry, and retail level. In this review, a number of potential strategies and novel technologies that could reduce the prevalence of Campylobacter in poultry meat have been identified and evaluated to provide a useful overview. At farm level for instance, biosecurity, bacteriocins, probiotics, feed and water additives, bacteriophages, and vaccination could potentially reduce colonization in chicken flocks. However, current technologies used in the chicken slaughter and processing industry may be less effective against this foodborne pathogen. Novel technologies and strategies such as cold plasma, ultraviolet light, high‐intensity light pulses, pulsed electric fields, antimicrobials, and modified atmosphere packaging are discussed in this review for reducing Campylobacter contamination. Although these measures have achieved promising results, most have not been integrated within processing operations due to a lack of knowledge or an unwillingness to implement these into existing processing systems. Furthermore, a combination of existing and novel strategies might be required to decrease the prevalence of this pathogen in poultry meat and enhance food safety. Therefore, further research will be essential to assess the effectiveness of all these strategies.     

茶多酚用于饮用水消毒的初步试验研究

介绍了植物多酚的基本性质及国内外的研究应用现状 .简要阐述了分子量较小的茶多酚用于饮用水消毒时 ,投加量、接触时间、环境影响因素和杀菌持续性等方面的试验研究结果     

医院消杀机器人作业安全与交互设计策略

作业安全与设计质量对提高医院公共环境消杀机器人"人机系统"运行效率具有关键作用.以人因工程学、交互科学、认知科学理论为视角,探究医院消杀机器人作业安全与交互设计策略.采用层次任务与表格任务结合H TA-T分析法,构建消杀作业任务流程,剖析作业流程中典型安全事故及其致因逻辑,基于工作域分析法(WDA)对消杀作业约束条件进...     

Efficacy of a high free iodine barrier teat disinfectant for the prevention of naturally occurring new intramammary infections and clinical mastitis in dairy cows

Using a natural exposure trial design, the goal of our study was to evaluate the clinical efficacy of an iodine teat disinfectant with barrier properties and a high level of free iodine relative to a conventional iodine teat disinfectant with no barrier properties and low levels of free iodine. During the 18 wk of the trial, quarter milk samples were collected every 2 wk from 385 dairy cows from 2 herds. Cows on both farms were assigned in a balanced way according to milk yield, number of lactation, days in milk, somatic cell count (SCC) and microbiology culture pretrial into one of following groups: nonbarrier post milking teat disinfectant (NBAR; n = 195 cows; 747 quarters) or barrier postmilking teat disinfectant (BAR; n = 190 cows; 728 quarters). Afterward, at each scoring date every 2 wk, milk SCC was quantified in samples from all mammary quarters and microbiologic culture was only performed on milk samples with SCC >200,000 cells/mL for multiparous cows and SCC >100,000 cells/mL for primiparous cows. A new intramammary infection (NIMI) was defined when a quarter had milk SCC <200,000 cells/mL for multiparous cows and <100,000 cells/mL for primiparous without microorganism isolation, and in a subsequent sampling visit had milk SCC >200,000 cells/mL for multiparous cows and >100,000 cells/mL for primiparous cows, and positive microorganism isolation. A quarter could have several NIMI, but only 1 case per specific pathogen was considered. The most frequently isolated microorganism group on both farms was Streptococcus spp. (6.25% of total mammary quarters), followed by coagulase-negative staphylococci (3.6%) and Corynebacterium spp. (1.5%). In the present study, an interaction occurred between treatment and week of trial on the incidence risk of NIMI. Quarters disinfected with BAR had 54 and 37% lower odds of NIMI than quarters disinfected with NBAR at 8 and 16 wk of the trial, respectively; whereas at other weeks of the study both products had similar incidence risks of NIMI. Overall, teats disinfected with BAR had 46% lower odds of acquiring a clinical mastitis than those disinfected with NBAR. We concluded that the postmilking teat disinfectant with barrier properties and higher free iodine content reduced the risk of clinical mastitis, although differences in new infections were detected at only weekly time points.     

人工模拟肠炎沙门氏菌在绿豆芽中的内化定殖能力及其消毒处理研究

本研究以绿豆为作用载体,研究了肠炎沙门氏菌(ATCC13076)在绿豆芽的不同发芽阶段中的内化定殖能力及消除绿豆芽中定殖的肠炎沙门氏菌的有效方法。结果表明:在绿豆发芽前期的4个不同时段(0~48 h内):吸胀期(G_1,0 h)、萌动期(G_2,12h)、发芽初期(G_3,24 h)、发芽期(G_4,48 h),分别接种10~2、10~4、10~6和10~8 CFU/mL的肠炎沙门氏菌时,其在绿豆芽中的内化定殖能力不同。接种浓度为10~2CFU/mL左右时,肠炎沙门氏菌在发芽初期(G_3)和发芽期(G_4)的内化能力较强,另外两个阶段比较微弱。接种浓度不低于10~4CFU/mL时,肠炎沙门氏菌在吸胀期(G_1)的内化能力最强。在吸胀期(G_1)接种10~8CFU/mL的菌液时,最高内化量可达2.6×10~8CFU/g。紫外照射消毒处理对内化定殖的肠炎沙门氏菌有明显的去除效果,而次氯酸钠溶液和硝酸银溶液浸泡处理对内化的肠炎沙门氏菌的去除效果并不明显。     

Green synthesis of biocidal silver-activated charcoal nanocomposite for disinfecting water

We report for the first time the green synthesis of silver nanoparticles using West Indian cherry (Malpighia emarginata) extract known for its high vitamin C content. UV–visible spectroscopy, powder X ray diffraction (PXRD), dynamic light scattering (DLS), scanning electron microscopy (SEM) and energy dispersive X ray spectroscopy (EDX) analysis were used to characterise silver nanoparticles. Silver nanoparticles thus synthesised exhibit antimicrobial activity against gram-negative bacteria such as Pseudomonas aeruginosa, Escherichia coli, and gram-positive bacteria such as Bacillus subtilis and Staphylococcus aureus. The antimicrobial property of nanoparticles thus synthesised was applied in the production of silver-activated charcoal nanocomposite towards fabrication of antimicrobial water filtration columns. The microbial filtration efficiency of the nanocomposite was found to be higher compared to virgin activated charcoal even with reusage.     

紫外/过氧化氢（UV/H2O2）高级氧化工艺在饮用水处理中的应用

通过砂滤池出水后接UV/H2O2高级氧化中试试验设备并投加特征污染物,考察了UV,UV+颗粒活性炭(GAC),UV/H2O2,UV/H2O2+GAC工艺对阿特拉津、嗅味物质及消毒副产物生成量的去除效果,发现UV/H2O2+GAC工艺对土臭素去除效果最好,去除率高达95%以上;对MIB和阿特拉津的去除效果比较接近,去除率在70%以上;UV/H2O2能有效去除消毒副产物前体物、减少消毒副产物的生成。     

水处理工程的消毒方法比较

在水处理中,消毒工艺的目的主要是杀死对人体健康有害的病原微生物,常用的方法有氯消毒、次氯酸钠消毒、二氧化氯消毒、臭氧消毒、紫外线消毒和活性氧消毒剂法等。文章重点分析以上消毒方法的机理及各自的优缺点,为工程选择提供理论依据。     

污水处理厂利用次氯酸钠消毒实验研究

粪大肠菌群是污水处理厂出水的一个重要指标,次氯酸钠是一种真正的高效、广谱、安全的强力灭菌、杀病毒药剂。固戍污水处理厂通过实验投加不同量的次氯酸钠溶液,使出水水质粪大肠菌群数不超过最高允许排放浓度,并得出最佳的投加量。     

污水处理厂消毒方式探讨

针对国内城市污水处理厂出水消毒的现状,分别介绍了紫外线消毒、液氯消毒和二氧化氯消毒工艺的原理、优点和缺点,影响消毒效果的因素,以指导相关人员合理选择消毒工艺,提高污水消毒效率。