乳酸左氧氟沙星注射液中细菌内毒素的检测

目的:建立凝胶法进行注射用乳酸左氧氟沙星注射液中细菌内毒素检测的方法.方法:用不同厂家的鲎试剂对不同批号的注射用乳酸左氧氟沙星注射液分别进行干扰实验,考察确立注射用乳酸左氧氟沙星注射液中细菌内毒素检测法.结果:注射用乳酸左氧氟沙星注射液样品浓度在1.0 g·L-1以下时可消除干扰,结果准确可靠.结论:注射用乳酸左氧氟沙星注射液可用内毒素检查取代热原检查法.     

噬菌体在控制细菌感染中的临床应用

近年来,由于多重耐药菌感染引起新的威胁,而新型抗生素的研发进展缓慢且成本昂贵,使得噬菌体被重新考虑作为抗生素的替代疗法。本文旨在阐述噬菌体疗法在控制人类常见病原菌感染领域的研究进展以及开发噬菌体的新策略,并总结描述多种方法学理念,以促进对其进一步研究,早日使噬菌体作为治疗或预防药物应用于临床实践中。     

噬菌体治疗细菌感染的研究

20世纪前叶噬菌体曾经作为治疗、预防细菌感染的有效工具，但随着抗生素的发明和应用，噬菌体研究未进一步深入。目前全球耐药菌感染率不断攀升，许多研究者又将目光对准了噬菌体，并预测噬菌体可以解决目前这一难题。综述噬菌体治疗细菌感染的发现、发展和现状，提出噬菌体作为一种生物制品，广泛应用于临床还要经过相当长的时间。     

动态浊度法检测乳酸左氧氟沙星氯化钠注射液中的细菌内毒素

目的:应用动态浊度法定量测定乳酸左氧氟沙星氯化钠注射液中的细菌内毒素,并与凝胶法比较。方法:按《中国药典》2010年版二部收载的细菌内毒素检查方法及其指导原则进行干扰试验,确定样品最大稀释倍数。结果:当样品作8倍稀释时用动态浊度法的回收率值较高(100%左右),未见干扰作用;与凝胶法检测结果一致,均符合规定。结论:动态浊度法可以有效测定乳酸左氧氟沙星氯化钠注射液中的细菌内毒素含量。     

副溶血弧菌噬菌体的发酵优化及中试制备工艺探索

目的 为了以低成本的方法制备出高效价的噬菌体制剂,对副溶血弧菌噬菌体Vpas_PP24的发酵条件和关键工程化制备工艺进行探索。方法 采用单因素实验法,研究噬菌体Vpas_PP24发酵体系的不同培养基、金属离子、pH、接种量及培养时间对其效价的影响;在中试规模对优化发酵工艺进行了工程化放大;并以膜过滤结合热除菌法进行了下游工程化噬菌体分离及终端除菌工艺探索。结果 确立了副溶血弧菌噬菌体Vpas_PP24的最优培养基及最佳发酵条件。摇瓶水平最适出发培养基为2216E液体培养基;Mg2+和Ca2+可促进Vpas_PP24的增殖,且最适浓度为30 mmol·L-1;最适pH为8;VP8最适接种量为1%;最适培养时间为16 h。在摇瓶水平优化后的效价达到3.0×1010 PFU/mL,较优化前提高了14倍。随之,基于该优化条件,成功将噬菌体发酵放大到50 L中试规模,并建立上游液体深层发酵工程化生产Vpas_PP24的上游工艺,效价达到3.2×1010 PFU/mL,与此同时,建立了下游噬菌体除菌工艺,得到效价为2.5×108 PFU/mL的噬菌体Vpas_PP24批量液体制剂。结论 系统优化了噬菌体Vpas_PP24的发酵条件,并在中试规模进行了工艺放大,成功建立了中试上游噬菌体发酵工艺及下游噬菌体分离工程化工艺及末端去除宿主菌的技术手段,为噬菌体类替抗产品的工程化生产提供了可参考的范例。     

乳酸左氧氟沙星葡萄糖注射液的制备及质量控制

左氧氟沙星 (L evofloxacin)为氟喹诺酮类抗菌药 ,系氧氟酸的光学活性 L 型异构体 ,对革兰氏阳性球菌和阴性杆菌的抗菌活性较氧氟沙星强两倍 [1 ] 。我们对乳酸左氧氟沙星葡萄糖注射液的制备工艺及质量控制进行了研究 ,现报道如下。1　仪器与试药UV- 2 6 0分光光度计 (日本岛津 ) ,WZZ- 2自动旋光仪 (上海物理光学仪器厂 ) ,TG32 8A光学读数分析天平 (湘仪天平仪器厂 ) ,乳酸左氧氟沙星原料 (浙江仙居司太立医院化工厂 ,批号 990 188)。乳酸左氧氟沙星对照品 (同批原料经 75 %乙醇重结晶三次 ,非水滴定法测含量为 99.0 % ) ,5 %葡萄糖注…     

用于鼠疫疫苗纯菌检查的噬菌体裂解法的建立

目的  建立用于鼠疫疫苗纯菌检查的噬菌体裂解法,并与现行的直接接种纯菌检查方法进行比较。方法  使用鼠疫噬菌体裂解在细菌分类学上与鼠疫杆菌相近的细菌及常见的污染细菌,确定鼠疫噬菌体对鼠疫杆菌裂解的特异性。分别将小肠结肠炎耶尔森菌和大肠杆菌定量掺入鼠疫疫苗来制备模拟污染鼠疫疫苗,采用噬菌体裂解纯菌检查方法检测模拟污染鼠疫疫苗,并将检测结果与现行的直接接种纯菌检查方法的检测结果进行比较。结果  鼠疫噬菌体能特异性地裂解鼠疫杆菌,对在细菌分类学上与鼠疫杆菌相近的细菌以及常见的污染细菌无裂解作用。对模拟污染鼠疫疫苗中的小肠结肠炎耶尔森菌和大肠杆菌的检出限,噬菌体裂解法均为1 CFU/剂疫苗（50 μl疫苗）,现行的直接接种法分别为50和5 CFU/剂疫苗（50 μl疫苗）。 结论   噬菌体裂解纯菌检查方法具有较好的敏感性和特异性,可用于鼠疫疫苗的质量控制。     

玉米浆质量的控制及其对青霉素发酵生产的影响

玉米浆是用亚硫酸浸泡玉米浆的水经过浓缩加工制成的,是鲜黄色到暗褐色的浓稠,不透明的絮状悬浮物,约含50%干物质,由于玉米浆中含有较丰富的可溶性蛋白质,很易被菌体利用,故为抗生素发酵的良好氮源,它还含有笨乙胺和苯丙氨酸,这些组分显然亦有青霉素 G 前体的作用,因此,在培养基中加     

乳酸菌作为载体的异源蛋白表达及应用研究进展

乳酸菌是公认的食品级安全微生物,利用乳酸菌作为表达载体进行抗原表达,能诱导机体产生有效的免疫应答。经口服和滴鼻免疫还可诱导机体的黏膜免疫应答,且接种方便,免疫效果和依从性均优于传统的注射途径。此文就乳酸菌作为表达载体的优势、表达系统的组成、目前成功表达的异源蛋白以及新型传送系统革兰阳性菌增强基质颗粒的研究进展做一综述。     

In vitro ability of lactic acid bacteria to inhibit mastitis-causing pathogens

Bovine mastitis is one of the most important diseases in high-yielding dairy herds. Recently, the state-of-the-art treatment of mastitis has been that of antibiotic therapy. Due to increasing antibiotic resistance in pathogens, alternative and sustainable therapeutics have to be sought. Probiotic microorganisms possess such curative capabilities and therefore the aim of the present study was to isolate lactic acid bacteria (LAB) which are able to inhibit mastitis-causing pathogens in vitro. 416 isolates of LAB were obtained from 1532 samples (quarter foremilk samples, bulk milk, grass, manure and bedding materials). 367 isolated wild isolates, two reference strains (Lactococcus (Lc.) lactis subsp. lactis ATCC 11454, Lactobacillus (Lb.) rhamnosus ATCC 7469) and six combinations were screened with agar well diffusion assay for their ability to inhibit the growth of Staphylococcus (S.) aureus, S. epidermidis, S. xylosus, Streptococcus (Sc.) uberis, Sc. agalactiae and Escherichia (E.) coli. 170 wild isolates inhibited the growth of Sc. uberis, 78 S. epidermidis, 37 S. aureus, 36 S. xylosus, 14 E. coli and 13 Sc. agalactiae, respectively. Only the combination of the wild strains 78/37 (Lb. paracasei), 118/37 (Lb. plantarum) and the reference strains inhibited the growth of all six indicator pathogens. These four strains were further capable of growing in milk as a substrate and of adhering to teat canal epithelium cells in vitro. It can be concluded that lactic acid bacteria may have the potential to be used as probiotics to prevent and to treat bovine intramammary infections in a more sustainable way in future.     

Antibacterial effects of enniatins J1 and J3 on pathogenic and lactic acid bacteria

Enniatins (ENs) are N-methylated cyclohexadepsipeptides, secondary metabolites produced by various species of the genus Fusarium. They are known to act as antifungal, antiyeast and antibacterial and to possess antiinsecticidal and phytotoxic properties. In this study we evaluated for the first time the antibiotic effect of pure fractions of EN J₁ and J₃ on several pathogenic strains and lactic acid bacteria.The ENs J₁ and J₃ were purified from the fermentation extract of Fusarium solani growth on solid medium of wheat kamut, using the technique of the low pressure liquid chromatography (LPLC) followed by a semipreparative liquid chromatography (LC). The purity and the structure of the isolated compound were confirmed by electrospray ionization-mass spectrometry study-linear ion trap (ESI-MS-LIT).The use of both chromatographic techniques have permitted to produce and purify 47 mg of the En J₁ and 50 mg of the EN J₃ with a mean purity of 98% completely characterized with the technique of the ESI-MS-LIT.Microbial bioassay analyses were carried out by incubation in MRSA and TSA for acid lactic and pathogenic bacteria, respectively during 24 h at 37 °C. None of the tested strains were inhibited by a 1 ng dose of EN J₁ and J₃. These compounds were only not effective against Listeria monocytogenes, Pseudomonas aeruginosa and Salmonella enteric. This study highlight ENs J₁ and J₃ could be potentially effective antibacterial agents against several pathogenic and lactic acid bacteria.     

Effect of ginseng polysaccharide on the stability of lactic acid bacteria during freeze-drying process and storage

Lactic acid bacteria (LAB) quickly attenuate or are killed during the freeze-drying process and storage. The effect of some natural polysaccharides, which are known as potent antitumor and immunomodulating substances, on the viability of the LAB, Lactobacillus acidophilus and Bifidobacterium breve, on freeze-drying and storage were investigated. Among the polysaccharides tested, red ginseng polysaccharide (RGP) and chitosan significantly inhibited the cell death of the LAB during freeze-drying, and fucoidan and RGP most potently protected the cell death of the LAB during storage. The stabilities of the LAB on the addition of RGP and fucoidan were comparable to that of skimmed milk. However, white ginseng polysaccharide (WGP) did not promote storage stability. When 5% skimmed milk/5% RGP treated LAB were freeze-dried and stored, their viabilities were found to be significantly higher those treated with 5% or 10% RGP. The stabilizing effect of 5% RGP/5% skimmed milk during LAB freeze-drying and storage stability was comparable to that of treatment with 10% skimmed milk. Based on these findings, we believe that RGP beneficially improves the stability of LAB during the freeze-dry process and storage.     

动脉血乳酸水平及乳酸清除率评估感染性休克预后的意义

目的 评价动脉血乳酸及乳酸清除率评估感染性休克患者预后的意义.方法 记录64例急诊重症监护室(EICU)的感染性休克患者入住重症监护室(ICU)1h内、6h、12 h、24h、48 h的血乳酸浓度,并计算12 h时的乳酸清除率,根据治疗后的转归分成两组,存活组和死亡组.比较两组血乳酸水平及乳酸清除率.结果 存活组和死亡组人ICU时血乳酸浓度分别为(7.2±5.4) mmol/L和(9.2±5.6) mmoL/L,均大于正常.存活组6h后开始下降,24h为(2.2±1.3) mmol/L,基本正常;而死亡组48 h血乳酸浓度为(8.0±3.8) mmol/L,仍明显大于正常,直至死亡,两组差异有统计学意义(t=3.7816,3.8257,7.5263,4.5875,5.8765,P＜0.05).死亡组患者12 h时乳酸清除率[(5.83±3.92) mmol/L]明显低于存活组[(14.32±2.68) mmol/L](t=6.2565,P＜0.05).结论 动脉血乳酸浓度与感染性休克患者预后呈正相关,乳酸清除率动态反应病情进展,是判断危重病严重程度的早期、敏感、定量的指标.     

Determination of sialic acid and gangliosides in biological samples and dairy products: A review

Gangliosides are sphingolipids containing one or more moieties of sialic acid in their structure. Both gangliosides and sialic acid are bioactive compounds related to animal physiology. Due to their biological relevance, analytical methods adapted to each type of matrix have been developed over time. The present study reviews the main methods applied to the analysis of sialic acid and gangliosides in biological samples and dairy products.     

A study of the residual fermentation sugars influence on an alternative downstream process for first and second-generation lactic acid

Lactic acid is an important biomolecule with a substantial market share. Currently, investments in the area are concentrated on new substrates and technologies, in order to boost production and separation performance. Molecular distillation has been recognized as a promising technology in the separation, purification, and concentration of natural products and hence with potential for application in the lactic acid production process. In this study, lactic acid was produced by fermentation using first (1G) and second-generation (2G) substrates, producing a complex mixture of lactic acid and residual sugars. The influence of the residual sugars, such as glucose, sucrose, and xylose, was investigated. For the 1G process, the results showed that the highest lactic acid concentration (99.51 g/L) can be obtained using the feed stream with the lowest sugars composition. For the 2G process, the highest lactic acid concentration reached (75.87 g/L) was lower than that observed for 1G experiments. The concentration of lactic acid using 1G or 2G lactic acid were, respectively, 2.73 times and 2.12 times higher than the initial raw material concentration, without the use of any extra solvent. The final process analysis showed that the use of molecular distillation for lactic acid downstream has different challenges to defeat for the separation of 1G and 2G lactic acid, which is relevant since many different feedstocks may be used in the lactic acid production.     

克拉维酸发酵工艺的优化研究

以棒状链霉菌 CA- 0 3- F2 为出发菌 ,进行克拉维酸发酵工艺的优化研究 ,结果表明在控制培养温度 2 8℃ ,搅拌转速 4 0 0 r/ min,罐压 0 .0 5 Mpa,空气流量 0 .5 vvm,保证溶氧浓度 4 0 %以上以及适当控制培养基中各成分含量的情况下 ,发酵效价可从 2 14 0 μg/ ml提高到 3132 μg/ ml     

火焰原子吸收光谱法测定7种乳制品中微量元素及乳酸的含量

目的:测定7种乳制品中6种微量元素及乳酸的含量,证明乳制品中含有丰富的营养物质.方法:首先对7种乳制品进行消化:(1)采用火焰原子吸收光谱法对处理后的乳制品样品溶液中的Ca、Fe、Zn、Mg、Mn、Cu 6种无机元素进行直接定量分析测定;(2) 间接测定法测定乳酸含量.取一定量的消化后的乳制品样品溶液,使其与FePO4悬浮液作用,再用火焰原子吸收分光光度法直接测定Fe的含量,从而得出乳酸的含量.此种方法简单,精密度和灵敏度高.结果:7种乳制品中,Ca、Cu、Fe、Mn、Zn及乳酸含量相对较为丰富.结论: 乳制品中含有丰富的人体所必需的微量元素,同时乳酸含量也很丰富,长期饮用乳制品不但可以补充人体对微量元素的需求,而且乳制品中的乳酸也有助于人体消化吸收.因此,长期饮用乳制品有利于人体健康.