以甘草为原料的食品天然防腐剂的研制

采用不同的溶剂和提取条件,提取甘草中的抗菌有效成分,然后通过抑菌试验筛选出抗菌力最强的制剂,通过测定该制剂对常见食品污染菌的最小抑菌浓度(MIC),证实该制剂对多种常见的食品污染菌均有较强的抑制作用,保存试验证实本制剂能有效地延长食品的保质期。     

常用微生态制剂的体外药敏试验

目的了解常用微生态制剂与一些常见抗菌药物的体外相互作用。方法从3种微生态制剂(美常安、妈咪爱、培菲康)中培养并分离供试菌,用电子显微镜和药敏纸片做鉴别及药敏试验。结果3种微生态制剂对常用的抗菌药物均敏感。尤其是制剂中的杆菌类对所选的抗菌药物几乎都敏感,而屎肠球菌和粪肠球菌对各种抗菌药物表现出不同程度的耐药。结论除阿莫西林外,常用的抗菌药物不宜与美常安、妈咪爱、培菲康配伍。     

生殖道中具有抑菌活性乳酸菌的分离筛选及其抑菌物质分析

目的 从阴道炎患者的棉拭子样本中分离筛选具有抗菌活性乳酸菌,为研究对细菌性阴道炎具有确实疗效的微生态制剂提供理论与菌种保证.方法 应用纯培养技术及双层平板法从阴道样品中分离筛选具有较好抑菌活性的乳酸菌.通过有机酸排除试验、过氧化氢排除试验和蛋白类抑菌物质排除试验对具有较好抑菌活性菌株的主要抑菌物质分析,并通过PCR反应对是否具有细菌素相关基因进行鉴定.结果 从7个棉拭子样本中共分离得到26株乳酸菌,其中有6株呈现抑菌活性.K4M2、K4M5、K4M6和K4M8菌株的主要抗菌物质为有机酸.而K4M9、K4M10两株植物乳杆菌的主要抗菌物质除有机酸外,尚可以产生细菌素.病原菌拮抗试验结果表明,这两株菌株的混合培养上清对具有较好的抑菌效果.结论 K4M9、K4M10菌株有望作为微生态制剂用于细菌性阴道炎的临床防治.     

关于吸附精制百日咳菌苗、白喉、破伤风类毒素混合制剂配方的实验报告

本文对吸附精制百白破混合制剂的不同配方进行了实验,结果表明,新一代吸附精制百白破混合制剂最佳配方为：精制百日咳菌苗１８μｇＰＮ／ｍｌ、精制白喉类毒素为３０Ｌｆ／ｍｌ、精制破伤风类毒素为１０Ｌｆ／ｍｌ。由该配方组成的吸附精制百白破混合制剂,其中百日咳菌苗的毒性试验ＢＷＤＵ／ｍｌ、ＬＰＵ／ｍｌ、ＨＳＵ／ｍｌ三种指标均符合制检规程要求。其效力单位（ＩＵ／ｍｌ）超过规程要求一倍以上,精制白喉和破伤风类毒素的安全试验均符合规程要求,白类效力试验≥８０－１００％,破类效力试验≥０．５－４．５ＩＵ／ｍｌ。上述结果说明本文提出的配方作为新一代精制百白破混合制剂的配方是适宜和实用的。     

噬菌体抗菌治疗安全性评估体系的建立

人类已经进入后抗生素时代,噬菌体治疗近年来重新备受重视,噬菌体制剂不同于传统抗菌药物,已有对传统抗菌药物的安全性评估体系不适合用于对噬菌体治疗制剂的评估,需要建立对噬菌体治疗安全性评估的体系。本文就噬菌体治疗所涉及的安全性问题进行系统分析研究,通过噬菌体本身的选择、噬菌体制剂制备、制剂形式、制剂给予途径、剂量和频次等,以及噬菌体治疗细菌感染性疾病患者选择等所涉及的安全性和噬菌体治疗对周围微环境的影响等进行全面分析。建立噬菌体治疗安全性评估体系,为噬菌体治疗尽早进入临床奠定基础。     

抑菌生防治大鼠烫伤创面绿脓杆菌感染的实验研究

通过对40只大鼠背部造成10％Ⅲ°烫伤感染绿脓杆菌后,分别用抑菌生和AG—SD霜进行生物拮抗试验。结果表明:抑菌生是强有力的生态抗菌制剂,对有耐药性但对AG—SD不产生耐药的绿脓杆菌引起的烧伤创面局部感染具有较强的防治效果,疗效优于AG—SD。     

“919”生态制剂防治雏鸡白痢的研究

实验表明：“９１９”生态制剂与抗菌药物组比较雏鸡白痢发病率Ｐ＞０．０５。空白对照组发病率与“９１９”生态制剂组比较Ｐ＜０．０１。２周龄雏鸡平均体重：“９１９”生态制剂组１０９．１７ｇ,抗菌药物组１０６．６７ｇ,空白对照组９９．５８ｇ。全期成活率“９１９”生态制剂组为９０．６０％、抗菌药物组为９０．３０％、空白对照组为８２．２０％。结果显示“９１９”生态制剂防治雏鸡白痢效果明显,并对雏鸡有较明显的增重作用。     

抗菌整理织物的抗菌效力测试

本文对大连印染厂试产的X—Si—4有机硅等抗菌整理布进行了抗菌效力检测,显示对细菌具100％的抑菌率,而且有较强皮肤癣菌和污染性霉菌的效力,同时具耐紫外线照射,耐高温高压,耐洗涤等优良性能。试验均达预期效果,表明方法简易,重复性好,结果可信。本文并从菌种的选择,试验方法的配合使用,抗菌整理布的优良性能测试等诸方面进行了探讨。     

生态制剂对雏鸡早期污染鸡白痢沙门氏菌的预防效果

本文阐述了应用双乳生(双歧杆菌和乳杆菌复合制剂)、促菌生、抗菌药和先用抗菌药后用双乳生对预防雏鸡白痢病的效果。试验结果表明,用生态制剂的各组,其日增重、存活率及饲料利用率均高于不用药物的对照组。同时揭示了在早期污染白痢沙门氏菌严重的雏鸡群,预防时以先用抗菌药后用生态制剂效果最佳。     

厌氧条件下微量琼脂糖弥散法抑菌试验的建立及应用

作者建立了在厌氧条件下两种微量而敏感的抑菌试验,可用于鉴定蛋白质或多肽类抑菌物质。（１）琼脂糖弥散法：可检测抗菌蛋白抑菌活性,（２）电泳凝胶弥散法：可直接确定存在于ＰＡＧＥ凝胶中抗菌蛋白条带。应用这两种方法,作者首次鉴定出血链球菌培养上清液中存在抑制牙周可疑致病菌的抗菌蛋白。     

Phleichrome; A New Phytotoxic Compound Produced by Cladosporium phlei

Bottle choice tests using liquid diets were done with Sprague-Dawley (SD) rats. SD rats ingested more oil-and-sucrose-enriched milk (hi-fat) and less oil-enriched milk (hi-fat-no-carb) than sucrose-enriched (hi-carb) milk by two-bottle choice tests after they were habituated to liquid diets for 4 days. Chronic food restriction didn't increase hi-fat ingestion but hi-fat-no-carb. Rats ingested less without habituation, and overnight food deprivation increased intake. This increment was maintained after rats were free-fed. The difference in fat content of the maintenance diet had little effect on fat preference. These results showed SD rats prefer a sweet and fatty liquid diet than a sweet and lean liquid diet. Habituation and food restriction were more important than the composition of the maintenance diet to demonstrate a clear preference for the fatty liquid diet.     

Seasonal and successional dietary shifts of two sympatric rodents in coastal heathland: A possible mechanism for coexistence

Abstract Using microscopic analysis of faecal pellets, we compared the seasonal and successional patterns of food resource use of two Australian native rodents, the eastern chestnut mouse (Pseudomys gracilicaudatus) and the swamp rat (Rattus lutreolus) in a coastal heathland at Myall Lakes National Park, New South Wales. Using the Mantel test, the diets of the two mammal species were significantly different in autumn and winter but not in spring and summer. Further, the two species showed differential use of resources at the young and middle-aged stages of vegetation succession following fire. The mean dietary overlaps for pairs of individuals between the two species were relatively high in all seasons and successional stages, but they were significantly lower than those for pairs of individuals within each species in autumn and winter, and at the young and middle successional stages. Analysis of dietary niche position (γ) and breadth (β) showed lower γ and larger β for P. gracilicaudatus than for R. lutreolus, confirming previous observations that R. lutreolus is more specialized, and less opportunistic in diet than P. gracilicaudatus. Overall, the dietary separations of the two species were less marked in canonical space than they were for specific seasons and successional stages. These results, together with previous studies, indirectly suggest that while these two mammal species may be partitioning diet in autumn and winter in the middle stages, for spring and summer in the old successional stage they might need to partition habitats to facilitate their coexistence. Our results indicate that the local community is more dynamic and complex than previously thought and that other mechanisms of coexistence (e.g. temporal rotation of food resources) may be operating rather than traditional habitat and diet separation.     

A sensitive and efficient detection method for bovine viral diarrhea virus (BVDV) in single preimplantation bovine embryos

The objective was to develop a method to accurately and efficiently detect minute amounts of bovine viral diarrhea virus (BVDV) associated with a single embryo. There are two major challenges for BVDV detection in a single embryo: the test sensitivity and the efficiency of viral molecule recovery. These become even more critical when attempts are made to detect BVDV infections that occurred naturally, not through artificial exposure of the embryos to high affinity BVDV strains. We have developed a one-step sample preparation method that has increased the viral molecule recovery rate compared to the standard RNA isolation procedure by 7-100-fold. Instead of using the traditional virus exposure approach, we generated BVDV positive embryos via somatic cell nuclear transfer (SCNT) technology using BVDV positive donor cells. By combining the highly efficient sample preparation procedure with a sensitive one-step, real-time PCR system, we have developed a sensitive test that allows detection of as low as two copies of BVDV in a single embryo. This method will allow systematic risk assessment for BVDV transmission during in vitro embryo production via IVF or SCNT procedures.     

Food safety behaviour and handling practices among Saudi women during the COVID-19 pandemic

Although it is commonly known that viruses cannot multiply in food as they need a living host for growth, adenoviruses and corona viruses can reportedly survive on surfaces and food packages for several days. Therefore, food item mishandling could increase the risk of infection. In this cross-sectional study, we assessed the changes in the food purchasing habits, food safety behavior, and food handling practices among Saudi women during the COVID-19 pandemic. The study included 1356 women who were randomly approached via convenience sampling using an anonymous questionnaire distributed through various social media platforms. The variables were described in terms of frequency and percentage, and the Chi-square test was applied to assess the relationship between the dependent and independent variables. Approximately 62.5% of the participants were aware that SARS-CoV-2 is not transmitted via food. Most participants (90%) reported a shift from outdoor to indoor meal preparation, along with avoidance of visits to grocery stores for food purchase (55%) and increased usage of online grocery delivery services (27%). Most participants obtained good overall scores for food safety behavior during grocery shopping (mean score: 10.83±1.62/12 points, 90.25%), grocery unpacking at home (10.60±2.65/13 points, 81.55%), and personal hygiene (28.84±3.16/36 points, 80%). However, a moderate overall score was obtained for food preparation practices (7.77 ±1.91/12 points, 77.7%). Older and/or retired individuals, patients with chronic diseases, and/or individuals living with children showed better food safety behavior and handling practices compared to their counterparts. This study reported good overall food safety behavior and handling practice scores among participants under most categories studied. However, our results highlight the need for more customized public education programs for Saudi women, who are the primary food handlers in most households, particularly during food preparation, to further improve food safety practices and prevent potential food mishandling, which will eventually help preventing the spread of COVID-19.     

From Feasting to Cuisine: Implications of Archaeological Research in an Early Honduran Village

Research at the site of Puerto Escondido in northern Honduras produced evidence of foodways in one of the earliest known villages in Central America. Much of the material recovered is related directly or indirectly to the production, preparation, and consumption of food. In everyday practice, the organization of food consumption in villages like this would have been central to the reproduction of social relations. In other early villages in Central America, the use of food for political ends has been given a causal role in the development of social stratification. Drawing on evidence for one particular food practice, the preparation and consumption of fermented and unfermented cacao beverages, we argue that it is through the elaboration of cuisine—regimes of taste and presentation—that food production, serving, and consumption played both of these roles.     

A群C群脑膜炎球菌结合疫苗稳定性

目的评价A群C群脑膜炎球菌结合疫苗原液和成品的稳定性。方法分别将A群、C群脑膜炎球菌结合疫苗原液及A群C群脑膜炎球菌结合疫苗各选取连续3批,分别放置于37℃、20~25℃和2~8℃3种温度下,在一定的时间取样进行主要项目测定,在关键时间点进行全面检测。结果 A群结合疫苗原液于2~8℃保存9个月,20~25℃保存4周,37℃保存4 d;C群结合疫苗原液于2~8℃保存9个月,20~25℃保存6个月,37℃保存4周;A群C群脑膜炎球菌结合疫苗于2~8℃保存2年3个月,20~25℃保存6个月,37℃可以保存9周;各项检测指标均符合质量标准的要求。结论在2~8℃条件下,A群、C群脑膜炎球菌结合疫苗原液存放6个月,A群C群脑膜炎球菌结合疫苗存放2年,其质量稳定。     

A comparison of eating habits between retired or semi-retired aged subjects and younger subjects in full-time work

An analysis of eating habits in older retired subjects (“No Work group”) and younger subjects employed in full-time work (“Work group”) has been carried out. It used a questionnaire that assessed why individuals chose to eat or not to eat meals during the course of the day, and subjective responses to the meals. The questionnaire was answered every three hours over a “typical week” which, for the Work group, entailed working during the weekdays and resting at the weekend. For the “No Work” group, breakfast was the most frequently taken meal of the day whereas, for the “Work” group, this meal was often missed. Patterns of meal intake were not significantly different between the weekdays and weekend for the “No Work” group, but the “Work” group ate more hot food at the weekend. The reasons cited for eating/not eating a meal and for choosing the type of meal eaten were dominated by hunger/lack of hunger in both groups. In addition, whereas habits were also important for the “No Work” group, it was time availability or the lack of it that was of major importance to the Work group, though this was significantly less important at the weekend. Meals which required more time for preparation and cooking were appreciated significantly more (appetite before the meal, enjoyment during it, and satiety afterwards) than meals such as snacks and cold food, which could be prepared more quickly. Some implications of these results, with regard to regular meals acting as a social zeitgeber in older subjects and the additional constraints imposed upon night workers, are considered.     

无机高分子絮凝剂PSAS的制备及其在赤潮防治中的应用

采用3因子3水平的正交试验设计,考察了SiO2浓度,Al^3 /SiO2摩尔比及pH对PSAS（聚硅酸硫酸铝）制备的影响,研究了PSAS对不同赤潮生物的絮凝作用,并与传统无机絮凝剂AS（硫酸）的絮凝效果进行了比较。结果表明,PSAS絮凝不同种类赤潮生物的最佳制备条件不同。根据实验操作的可行性,得出PSAS的适宜制备条件为：SiO2的浓度2％,Al^3 /SiO2摩尔比1,pH4,絮凝实验表明,PSAS的絮凝效果明显优于AS,在达到相同去除率的情况下,PSAS的用量比AS低约30％－40％,PSAS对不同种类赤潮生物的絮凝效率也不同,与细胞的生理生态特性差异有关。     

草鱼出血病病毒抗原亚单位的研制

通过比较溶液的离子浓度对病毒形态的结构的影响,发现ＧＣＨＶ在低盐溶液盐低温（－２０℃）保存条件下,外壳蛋白会自动降解,但不十分完全,采用含１％ＮＰ４０（Ｎｏｎｉｄｅｔ－ｐ４０）的稀盐溶液处理感染病毒的细胞,经冻融及差异离心,电镜下观察到纯度较高的病毒双层衣壳,核心衣壳及散在的子粒。纯化的病毒亚单位用核酸酶消化后,与等量的福氏佐剂混合,免疫家兔制备抗体,该抗血清经台和试验测定,显示了较强的中和病毒的     

Application of real-time PCR for quantitative detection of Clostridium botulinum type A toxin gene in food

The TaqMan real-time PCR method for the quantitative detection of C. botulinum type A was developed based on sequence-specific hybridization probes. The validity of this assay was verified by using 10 genera of 20 strains, including reference strains of C. botulinum types A, B, C, D, E and F. The detection limit of this assay was evaluated on C. botulinum type A, using a 10-fold dilution series of DNA and spores . The DNA and spores were detected up to level of 0.1 ng/ml and 10(2)spores/ml, respectively. Spore spiked food sample preparation prior to the real-time PCR was performed by two methods, heat treatment and GuSCN. The detection limits after heat treatment showed 10(2) spores/ml for spiked sausage slurry, and 10(3) spores/ml for spiked canned corn slurry, while detection limits after GuSCN precipitation showed 10(2) spores/ml in both sausage and canned corn. Therefore the real-time PCR assay after GuSCN precipitation is useful for the quantification of C. botulinum type A because it showed identical CT values in both pure spore solutions and food slurries. We suggest that quantitative analysis of C. botulinum type A by TaqMan real-time PCR can be a rapid and accurate assessment method for botulinal risk in food samples.