抗菌塑料的抑菌效果评价

抗菌塑料是含锌离子的可溶性玻璃粉,具有杀菌、抑菌性能的新型功能材料。国外抗菌塑料的研究应用起始于20世纪80年代初。欧美国家早期在日用品中应用,近年在玩具产品上应用较多。日本在应用抗菌塑料方面发展更快。首先在家电产品中应用抗菌塑料,抗菌电话等产品一面市,就深受消费者的欢迎。抗菌材料一般具有抗菌、杀菌、防霉、消毒、除臭、防潮等功能。抗菌材料应用范围十分广泛,主要应用于家电设备、医院设施和医疗卫生器具、商店和其他公共场所的设备用具及其他生活日常用品等。随着抗菌材料研究开发的不断进展,其应用范围也必然日益广泛,功能也必然更加齐全。20世纪90年代中后期,抗菌塑料在我国飞速发展。其抗菌塑料产品不断增加,现在已经有抗菌塑料碗、塑料盘、塑料电话、以及食品加工业和餐饮业的机械设备等抗菌塑料产品在我国问世。本文根据抗菌塑料的作用原理和特性,对抗菌塑料效果进行监测探讨,为抗菌塑料的推广和应用提供依据。     

含铜抗菌不锈钢的抗菌性能研究

对铁素体和奥氏体2种含铜抗菌不锈钢的抗菌性能进行了考察.采用覆膜法检测抗菌率,用透射电镜观察与铁素体抗菌不锈钢作用后的大肠埃希菌细胞形态.2种抗菌不锈钢材料对供试的 17 株常见菌,除产气肠杆菌外均显示较强的抗菌性能,抗菌谱广;铁素体和奥氏体对1×107 cfu/mL及以下浓度的大肠埃希菌在 24 h内杀灭率达到99%;铁素体和奥氏体分别在作用 3 h和 9 h时可将1×107 cfu/mL的大肠埃希菌全部杀灭;打磨次数和环境温度的变化不影响2种抗菌不锈钢的杀菌率;透射电镜结果显示,与抗菌不锈钢作用后的大肠埃希菌菌体结构松散,细胞壁和细胞膜破裂,有内容物漏出.铁素体和奥氏体抗菌不锈钢均具优良的抗菌性能,抗菌谱广,与其作用后的细菌菌体破裂,有内容物溶出,最终致菌死亡.     

药用植物内生菌的分离及抗菌活性的初步研究

为研究药用植物金荞麦、款冬及黄皮树中内生菌的抗菌活性,筛选具有广谱抗菌效果的内生菌。以导致人畜及植物致病的15种病原微生物为拮抗菌株,采用改进K-B纸片法、生长速率法及琼脂二倍稀释法进行抑菌试验。结果从三种药用植物中共分离到内生菌38株,其中FE-R9、TE-R7、PE-S11三株内生真菌发酵液提取物对10种人畜指示菌的最低抑菌浓度(M IC)分别在7.50~15.00 g.L-1、3.13~12.50 g.L-1、0.39~15.00 g.L-1之间。FE-R9、TE-R7、PE-S11对多种病原微生物具有显著抑制生长的作用,这可为寻找天然抗菌物质提供资源。     

新疆部分特色林果果壳的抗菌活性研究

目的:研究新疆特色林果核桃、巴达木果壳乙醇提取物的抑菌特性。方法:用滤纸片法检验果壳乙醇提取物对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌和变形杆菌的抑菌活性,通过液体培养基稀释法测定最低抑菌浓度。结果:巴达木乙醇提取物(25%乙醇提取10 h)对大肠杆菌有较好的抑菌效果,最低抑菌浓度(MIC)为25%;核桃乙醇提取物(25%乙醇提取24 h)对大肠杆菌有较好的抑菌效果,MIC为6.25%。结论:核桃、巴达木果壳乙醇提取物对受试菌具有较好的抑菌效果,为进行大规模开发利用提供了有效依据。     

家蝇变形期抗菌蛋白的提取

目的:分离纯化家蝇变形期体内抗菌蛋白并分析其抑菌作用。方法:对家蝇（Ｍusca domestica）5日龄幼虫进行针刺诱导,并于24h后挑取变形后的蛹,通过研磨、调酸、加热提取蛹体内的耐热水溶总蛋白,经过两步CM sepharose F.F.离子交换层析分离,以金黄色葡萄球菌作指示菌,检测其抑菌活性,并用SDS PAGE不连续电泳检测蛋白质的分子量。结果:经两步离子交换分离后,得到一种对金黄色葡萄球菌具有较强抑菌活性的蛋白,经SDS PAGE检测为单一条带,其分子量为43kDa。结论:家蝇处于变形期时,经过诱导后体内能产生一种抑菌活力较强的蛋白质。     

千里光抗菌作用的数量性状分析

应用倍比稀释法检测18份千里光（Senecio scandens Buch-Ham）水煎剂对7种细菌的抗菌效果。最低抑菌浓度（minimal inhibitory concentration,MIC）检测结果表明,千里光对金黄色葡萄球菌的抗菌作用最强,对铜绿假单胞菌的抗菌效果最差。比较不同细菌的MIC值发现,温和气单胞菌共检测出4个不同的MIC值,金黄色葡萄球菌、铜绿假单胞菌、大肠埃希菌、甲型副伤寒杆菌、福氏痢疾杆菌和迟钝爱德华菌的MIC值为5个,迟钝爱德华菌的MIC值最多,表现出6个MIC梯度值。本研究结果提示千里光个体有效抗菌组分的多样性,也意味着千里光抗菌药理学性状为多基因控制的数量性状。     

枯草芽孢杆菌TF26抗菌蛋白抑菌活性的初步研究

目的:研究枯草芽孢杆菌TF26抗菌蛋白的抑菌活性和生物稳定性,为菌株及抗菌蛋白的应用提供理论依据.方法:采用硫酸铵盐析方法提取抗菌蛋白,采用菌丝生长速率法检测其对13种植物病原真菌的抑菌活性,采用抑菌圈方法对其生物稳定性进行分析.结果:抗菌蛋白粗提物能够抑制13种植物病原真菌的生长,平皿抑制率为74.3％ ～91.3％,对葵花菌核病菌、番茄和黄瓜枯萎病菌、黄瓜菌核病菌和立枯病菌、水稻恶苗病菌和大豆根腐病菌抑制作用较强.抗菌蛋白在100℃以下,pH＜ 10范围内抑菌活性稳定,对紫外线照射不敏感,室温(20℃)和4℃储存150d抑菌活性稳定.结论:抗菌蛋白具有较强的热、酸碱、紫外和储存稳定性以及广谱的抑菌活性.     

羊耳菊抗菌物质及其抑菌特性分析

通过硅胶柱层析法,结合活性追踪,从羊耳菊中分离到1种对水稻纹枯病菌具有较强抑菌活性的化合物,经菌丝生长速率法测定,其抑菌中浓度为47 mg/L。通过分析氢谱和碳谱数据,该化合物被鉴定为百里香酚,具有耐热、耐酸碱、抗紫外光和荧光的特性。百里香酚对15种植物病原真菌和4种植物病原细菌具有抑制作用,其中对水稻纹枯病菌、茉莉枝枯病菌、烟草黑胫病菌、香蕉弯孢霉叶斑病菌、白菜软腐病菌和木薯细菌性枯萎病菌的抑菌活性较强。     

RYH: a minimal peptidic sequence obtained from beta-chain hemoglobin exhibiting an antimicrobial activity

Bovine hemoglobin is an animal protein described as source of bioactive peptides. Enzymatic hydrolysis of this protein results into some peptides exhibiting antimicrobial activity against Gram-positive and Gram-negative bacteria. In this study, a family of peptides from the beta chain (beta-114-145 derived peptides) obtained by peptic hydrolysis of bovine hemoglobin, was purified by reverse-phase HPLC and characterized by different analytical techniques (mass spectrometry, circular dichroism). The minimum inhibitory concentration was determined to show the antimicrobial activity of these peptides. Four bacterial strains were used: two Gram-negative (Escherichia coli and Salmonella Enteritidis) and two Gram-positive strains (Listeria innocua and Micrococcus luteus). The effect of these peptides on artificial membrane was also measured. Our findings showed that the peptide β114-145 and its peptic derivatives contain the RYH sequence. The most antimicrobial peptide is the RYH peptide which was the shortest one.     

Change in Criteria for USP Dissolution Performance Verification Tests

The US Pharmacopeial Convention has been evaluating its performance verification tests (PVT) for several years. These tests help ensure the integrity of the US Pharmacopeia performance test when a dissolution procedure, as described in General Chapter Dissolution <711>, is relied upon to test a nonsolution orally administered dosage form. One result of the evaluation is a change in the PVT criterion from one based on individual tablet results to one based on the mean and variability of a set of tablets. This paper describes the new PVT and its criterion and how its acceptance limits are derived from results of a collaborative study, explains a two-stage option for the test, and presents operating characteristics.     

The antimicrobial properties of milkfat after partial hydrolysis by calf pregastric lipase

Studies on the kinetic characteristics of calf pregastric lipase (EC 3.1.1.3) have shown that it preferentially releases short chain fatty acids (SCFAs) from bovine milkfat. The released fatty acids form mixed micelle structures. The aim of this investigation has been to test whether hydrolysed milkfat is antimicrobial, and how the state of the emulsion alters the bactericidal or bacteriostatic effects. Partial hydrolysis of milkfat by pregastric lipase was carried out in two types of emulsion systems, containing either Triton X-100 or casein/lecithin, plus milkfat in citrate/phosphate buffer (pH 5.0-6.0). The concentrations and compositions of fatty acids were determined by gas chromatography. The minimum percentages of hydrolysed milkfat which affected growth and survival of selected Gram-positive and Gram-negative bacteria were measured. The bacterial experiments were repeated using pure fatty acids at similar concentrations. Lauric acid (C12:0) was found to be the most potent bactericidal fatty acid against Enterococcae (Gram-positive), and caprylic acid (C8:0) was the most potent against coliforms (Gram-negative). Use of Triton X-100 for milkfat emulsification provided a more compatible medium for studying bacterial growth in the hydrolysed milkfat than did use of casein/lecithin. The results also show that the antimicrobial effects of individual fatty acids released from hydrolysed milkfat were at least additive and suggest that hydrolysis of milkfat may be a significant factor in controlling growth of organisms imbibed with food in pre-weaned animals. The amount of pregastric catalyzed triglyceride hydrolysis in the digestive tract is sufficient to produce an antibacterial concentration of fatty acids and monoglycerides.     

Wald Tests of Location for Symmetric Nonnormal Data

For nonnormal data we suggest a test of location based on a broader family of distributions than normality. Such a test will in a sense fall between the standard parametric and non parametric tests. We see that the Wald tests based on this family of distributions have some advantages over the score tests and that they perform well in comparison to standard parametric and nonparametric tests in a variety of situations. We also consider when and how to apply such tests in practice.     

明胶/纳米SiO2复合膜的体外抑菌试验

本实验测定了明胶、纳米SiO2、明胶/纳米SiO2复合膜对6种供试菌的抑菌效果,结果表明,明胶不具有抑菌作用;纳米SiO2对供试菌具有较好的抑茵效果;20种明胶/纳米SiO2复合膜材料中,有11种复合膜对供试菌具有较强的抑菌效果.用琼脂平板稀释法测定了具有较强抑菌作用复合膜的最低抑菌浓度(MIC),结果表明,最低抑菌浓度因膜的配比和菌种类型的不同而有所差异,为16.0 mg/mL～256.0 mg/mL.复合膜对蜡样芽孢杆菌的最低抑菌浓度(MIC)最大(256.0 mg/mL),而对其他供试菌相对较低,为64.0 mg/mL～128.0 mg/mL.     

两种Ames试验方法在槲皮素致突变试验中灵敏度的研究

目的:通过传统Ames试验与改进彷徨试验对槲皮素的致突变试验结果,比较两种试验的灵敏度。方法:Ames试验方法采用平板掺入法,选择3.2、16、80、400、2000μg/mL 5个剂量组的槲皮素在有或无代谢话化条件下处理鼠伤寒沙门氏菌株TA98和TA100 48小时后计数回复突变菌落数;改进彷徨试验采用96孔板法,选择0.128、0.64、3.2、16、80μg/mL 5个剂量组的槲皮素在有或无代谢活化条件下处理鼠伤寒沙门氏菌株TA98和TA100 24小时后计数变色孔数。结果:Ames试验结果显示槲皮素在80-2000μg/mL回复突变菌落数明显增加并超过对照2倍并有明显剂量反应关系,Ames试验结果阳性;改进彷徨试验结果显示槲皮素在0.64-80μg/mL变色孔数明显增加(P<0.01),并有剂量反应关系,结果为阳性;而在0.64-16μg/mL剂量下,改进彷徨试验能检测出阳性结果,而Ames试验未检测出阳性结果。结论:在较低浓度时,改进彷徨试验能检测出Ames试验检测不出的阳性结果,表明改进彷徨试验灵敏度较Ames试验高。     

用正交实验法筛选营养缺陷型酿酒酵母原生质体的最佳实验条件

为了提高原生质体的再生率,用正交实验筛选了制备营养缺陷型酿酒酵母PW208菌株原生质体的条件。最佳条件为用柠檬酸缓冲液配制1％蜗牛酶,在30℃酶解60min后再经后处理可得99％的形成率和43％的再生率。     

乳酸杆菌代谢产物对引起阴道炎常见细菌的抑制作用的初步探讨

目的探讨乳酸杆菌代谢产物对临床常见引起阴道炎的大肠埃希菌、铜绿假单胞菌、金黄色葡萄球菌、白色念珠菌、伤寒杆菌和肠球菌的抑菌作用。方法采用营养琼脂平板培养基定量涂菌,国际标准药敏杯给药的药敏试验法,检测乳酸杆菌代谢产物对大肠埃希菌、铜绿假单胞菌、金黄色葡萄球菌、白色念珠菌、伤寒杆菌和肠球菌的抑菌环的大小。结果乳酸杆菌代谢产物对大肠埃希菌、铜绿假单胞菌、金黄色葡萄球菌和伤寒杆菌有明显的抑菌作用,对肠球菌、白色念珠菌无抑菌作用。结论在临床上可应用乳酸杆菌及其制剂调节阴道微生态平衡,治疗细菌性阴道炎。