菌株DM8320安全评价及其发酵乳对大鼠肾结石形成的影响

目的 对具有降解草酸能力的菌株DM8320进行初步安全性评价并观察其发酵乳对肾结石模型大鼠的影响.方法 通过检测DM8320的质粒,细菌易位试验以及急性毒性试验对DM8320进行初步安全性评价.构建大鼠肾结石模型的同时灌胃目的菌株的牛奶发酵乳,实验第29天,收集24 h尿液并检测尿液中钙离子、草酸的含量.取大鼠左肾制作石蜡切片,观察各个实验组结石发生情况.结果 菌株DM8320中不含质粒,未发生细菌易位现象,不具有毒性.DM8320发酵乳可降低肾结石模型大鼠尿中的草酸和钙离子含量.观察各组大鼠肾脏石蜡切片,结石组中结石含量最多,低剂量组次之,高剂量组肾结石结晶含量较少.结论 菌株DM8320具有一定的安全性,其发酵乳对Wistar大鼠肾结石的形成具有一定的抑制作用.     

一株降血压功能乳酸菌在模拟胃肠环境中抗性的研究

目的研究具有降血压功能乳酸菌DM9057株对pH、胆汁盐、胃蛋白酶及胰蛋白酶的耐受性。方法以MRS为基础培养基,模拟胃肠环境。结果 DM9057在pH2~3、胆汁盐浓度0.1%~0.3%、胃蛋白酶0.592~1.482μg/mL和胰蛋白酶14.24~72.32 U/g的条件下,37℃培养4 h,活菌数均能达到107CFU/mL以上。结论乳酸菌DM9057能顺利通过胃肠道,达到促进健康的作用。     

降血压乳酸菌发酵乳对原发性高血压大鼠的降压效果

目的对具有血管紧张素转化酶(ACE)抑制活性的乳酸菌DM9057发酵乳的抗胃肠道酶解能力及原发性高血压大鼠(SHR)体内降压效果进行研究。方法以10 ml/kg和2.5 ml/kg发酵乳一次性和连续灌胃原发性高血压大鼠。结果 DM9057发酵乳具有较好的抗胃肠道酶能力,并且2个剂量均具有较好的降血压效果,其中以10 ml/kg剂量效果最为显著,一次性和连续灌胃后,最大降压值为(17.97±3.82)、(25.46±5.06)mmHg。结论乳酸菌DM9057发酵乳具有较强的抗胃肠道能力,同时在原发性高血压大鼠体内能够发挥一定的降血压作用。     

五株乳酸菌和三株芽孢杆菌的生物学特性和功能

【背景】乳酸菌和芽孢杆菌是应用于生产最多的益生菌,但不同菌株间的生长特性均不相同,因此了解菌株的生物学特性具有重要意义。【目的】研究菌株的生物学特性,能合理地开发和利用菌株,以保证菌株生产应用的安全性。【方法】活化后鉴定5株乳酸菌和3株芽孢杆菌并对其形态进行观察,探究菌株的生长曲线、产酸能力及最适生长条件,测定菌株的抑菌活性和产酶性能,同时探究菌株的益生性和安全性。【结果】五株乳酸菌分别编号鉴定为干酪乳杆菌R1、副干酪乳杆菌R2、香肠乳杆菌R3、福莱乳杆菌R4和唾液乳杆菌R5;3株芽孢杆菌分别编号命名为贝莱斯芽孢杆菌Y1、枯草芽孢杆菌Y2和地衣芽孢杆菌Y3。八株菌形态结构均不相同但都为杆状,均在2–10 h为对数生长期,18–24 h为稳定期,培养24 h时乳酸菌和芽孢杆菌的活菌数均保持在10⁹和10⁸ CFU/mL,最适生长温度为37.0℃。乳酸菌具有较强的产酸能力和抑菌活性,芽孢杆菌有较强的产酶性,在人工胃液中都有较强的耐受性。八株菌都无溶血活性、无毒力基因、对抗生素都保持中度敏感以上;其中唾液乳杆菌有四环素耐药基因,但对四环素抗性为中度敏感。【结论】八株菌生长繁殖速度快,乳酸菌产酸能力和抑菌活性较强,芽孢杆菌具有较强的产酶性能,在体外具有较好的益生性和安全性,可应用于生产实践。     

两种高效抑菌乳酸菌素BSN4和BCN4的特性研究

对筛选到具有高效抑菌效果的植物乳杆菌SN4和粪肠球菌CN4产生的乳酸菌素进行进一步生物学特性研究。采用牛津杯法测定细菌素对金黄色葡萄球菌的抑菌效果,发酵上清制取乳酸菌素初提液,通过对两株乳酸菌产生的乳酸菌素进行蛋白酶、热和酸碱处理,研究其抑菌效果的稳定性,以及菌株的生长合成曲线和抑菌谱。试验结果表明:两种乳酸菌素对大部分蛋白酶较敏感,胰蛋白酶处理后乳酸菌素BSN4和BCN4分别能保留84%和55%活性;两种乳酸菌素在p H 4~10之间保持80%的抑菌活性(抑菌圈20 mm),在25~100℃处理20 min后能分别保留89.1%和74.4%以上的活性,乳酸菌素BSN4经120℃处理5 min后仍保留69%活性;菌株SN4在发酵10 h就能达到稳定期,并表现出较好地产酸性和抑菌活性。抑菌谱显示乳酸菌素BSN4和BCN4对革兰阴性菌和真菌无明显抑菌效果,但对大部分革兰阳性菌有较好的抑菌活性。结果显示,两种乳酸菌素对大部分革兰阳性菌有较好的抑菌效果,具有较好的环境耐受性,可为乳酸菌素在生产生活中的应用提供参考。     

对德氏乳杆菌DM8909菌株的药理学研究

由大连医科大学微生态学研究所从阴道中分离的德氏乳杆菌 DM890 9菌株经实验证明 ,其具有产乳酸和 H2 O2 的能力。为研究本菌株是否具有继续开发的前景 ,我们对其毒性及一般药理学进行了研究 ,现报告如下 :1　材料与方法1 .1　菌种及菌粉来源　实验采用的菌种是德氏乳杆菌 DM890 9菌株 ,其实验用菌粉系采用 DM890 9菌株经小罐发酵、离心分离、冷冻干燥、乳糖稀释制成 ,均由大连医科大学微生态学研究所提供。1 .2　急性毒性试验1 .2 .1　实验动物　昆明种小鼠 ,体重 ( 2 0± 2 ) g,雌雄兼用 ,共 5 0只 ,随机分成 5个剂量组 ,每组 1 0只。…     

降血尿酸乳酸菌筛选及其对高尿酸血症模型大鼠作用研究

目的 提出利用具特殊活性乳酸菌来预防、治疗高尿酸血症方法,筛选具有较高降血尿酸活性的乳酸菌.方法 基于RP-HPLC方法,通过检测培养液培养前后肌苷、鸟苷含量变化,筛选出具有最快核苷分解速率的乳酸菌株作为候选菌株.并将其施用于高尿酸血症模型大鼠,观察对模型大鼠血尿酸含量影响.结果 获得具有最佳核苷分解速率的菌株DM9218.动物实验结果表明DM9218干预组的血尿酸浓度(219.25±21.98) μmol/L明显低于模型组(311.75±27.07) μmol/L(P＜0.05).结论 菌株DM9218具有最快的核苷分解速率,对高尿酸血症大鼠具有明显的降血尿酸作用.菌株DM9218为植物乳杆菌(Lactobacillus plantarum).     

阿克苏地区传统酸乳中乳酸菌筛选及安全性初步评价

为挖掘新疆传统发酵乳制品中的优质乳酸菌资源,获得具有良好益生特性及食用安全性的乳酸菌菌株,对新疆阿克苏地区托木尔峰自然保护区周围村镇传统酸乳进行了样品采集、乳酸菌的分离、筛选及菌株生长特性、抗氧化活性和抑菌等功能特性的分析,并进行溶血性和有害代谢物质等食用安全性检测.16S rRNA测序结果显示,8份代表样品共获得12...     

DM891129菌株对沙土鼠高胆固醇血症的影响

本项研究的目的是通过动物实验来观察由健康人分离出的肠球菌DM891129菌株的降血脂作用。本实验选42只沙土鼠(gerible),雌雄各半,随机分为3组,第1组13只为正常组;第2组13只,在正常饮食中 5％胆固醇饲喂1周;第3组16只,在第2组饮食的基础上,每天以肠球菌(DM891129)菌悬液(10~9个细菌/ml)0.5ml/次,Bid灌胃一周。3组沙土鼠以眼球采血,分别检测血清胆固醇、甘油三酯和胆酸水平及粪便中肠球菌和肠杆菌水平。结果表明:第2组胆固醇水平较第1组明显升高(P<0.001)。第3组胆固醇水平较第2组明显降低(P<0.001)。相应的、第3组鼠粪便肠球菌水平明显高于第1、2组(P<0.05),而1、2组之间无显著性差异,第2、3组肠杆菌水平明显高于第1组(P<0.02、P<0.05),2、3组肠杆菌水平无显著性差异。胆酸、甘油三酯水平3组之间无显著性差异。可见DM891129菌株对沙土鼠高胆固醇饮食所致的高胆固醇血症具有明显的降低作用而对血甘油三酯、胆酸水平无显著性影响。现在对DM891129菌株体内降血胆固醇水平的机制尚不清楚,有待于进一步研究。     

具有降胆固醇功能益生菌的筛选研究

目的通过体外实验从发酵制品及人体肠道内分离筛选出安全高效的降胆固醇乳酸菌,并研究其生理生化特性,为今后功能性乳制品的开发提供优良菌种。方法应用MRS．胆固醇培养基液体发酵法进行目的菌株筛选,并测定其耐酸及耐胆盐等能力。结果筛选出4株具有降胆固醇能力的乳酸菌,其降解率分别为DM8403163．1％、DM8403470．3％、DM850381．1％、DM8605663．1％;同时4株乳酸菌均表现出不同程度的耐酸及耐胆盐能力,其中DM86056能力最强,其他3株乳酸菌次之;经鉴定,DM84031为保加利亚乳杆菌、DM84034为嗜热链球菌、DM8503为詹氏乳杆菌、DN86056为屎肠球菌。结论经上述实验综合比较,DM86056降胆固醇能力比较强且耐酸及耐胆盐等能力也较强,因此有待于将其应用于动物体内进行深入研究。     

Using mass spectrometry to explore the neglected glycan moieties of the antiophidic proteins DM43 and DM64

The resistance of the opossum Didelphis aurita to Bothrops snake venoms is attributed to the opossum's antihemorrhagic (DM43) and antimyotoxic (DM64) acidic serum glycoproteins. The aim of this study was to characterize the N-glycosylation sites of these antiophidic proteins and to determine whether their glycans influence the biological activity measured by in vitro assays. Our experimental pipeline included the sequential enzymatic digestion of the inhibitors with two different proteinases (trypsin and endoproteinase Asp-N) and eventually with trypsin, peptide-N-glycosidase F (PNGase F) and endoproteinase Asp-N, used in that order. All of the peptide and protein samples were analyzed by MALDI-TOF/TOF MS. The results experimentally confirmed the putative N-glycosylation sites of DM43 (Asn23, Asn156, Asn160, and Asn175) and DM64 (Asn46, Asn179, Asn183, and Asn379). Following treatments with specific glycosidases, complex-type oligosaccharides containing galactose and sialic acid could be assigned to both proteins. The removal of these monosaccharide units by exoglycosidase digestion did not measurably affect the inhibitory activity. In contrast, partially deglycosylated DM43 treated with PNGase F under nondenaturing conditions was half as effective as native DM43. In conclusion, we have demonstrated that the contribution of the carbohydrate portion of these potentially therapeutic molecules, for their mechanism of action, should not be overlooked.     

Isolation and characterization of DM40 and DM43, two snake venom metalloproteinase inhibitors from Didelphis marsupialis serum

From Didelphis marsupialis serum, two antihemorrhagic proteins were isolated by DEAE-Sephacel, Phenyl-Sepharose and Superdex 200 and characterized. Their masses by mass spectrometry were 40318 AMU for DM40 and 42373 and 43010 AMU for DM43, indicating the presence of isoforms for the last. Molecular masses of 44.8 and 47.3 were obtained by SDS-PAGE, respectively for DM40 and DM43. Both inhibitors showed isoelectric points lower than 3.5 and glycosylation percentages varying from 20.5 to 29.0%, as estimated by chemical deglycosylation and amino acid analysis. N-terminal sequences of the first 17 residues of DM40 and DM43 were identical except for the exchange of R9 for P9. Both were homologous to oprin, a similar inhibitor from Didelphis virginiana serum. No evidence of complex formation between DM40 and DM43 was observed either by native PAGE or gel filtration chromatography. In addition to the antihemorrhagic activity, DM40 and DM43 inhibited the hydrolysis of casein, fibrinogen and fibronectin by Bothrops jararaca venom. DM43 also showed antilethal, antiedematogenic and antihyperalgesic activities. None of the inhibitors showed enzymatic activity on casein. Both proteins formed stable complexes with jararhagin and inhibited its hemorrhagic effect as well as the enzymatic activity of this toxin on fluorogenic substrate.     

Screening and Characterization of Purine Nucleoside Degrading Lactic Acid Bacteria Isolated from Chinese Sauerkraut and Evaluation of the Serum Uric Acid Lowering Effect in Hyperuricemic Rats

Hyperuricemia is well known as the cause of gout. In recent years, it has also been recognized as a risk factor for arteriosclerosis, cerebrovascular and cardiovascular diseases, and nephropathy in diabetic patients. Foods high in purine compounds are more potent in exacerbating hyperuricemia. Therefore, the development of probiotics that efficiently degrade purine compounds is a promising potential therapy for the prevention of hyperuricemia. In this study, fifty-five lactic acid bacteria isolated from Chinese sauerkraut were evaluated for the ability to degrade inosine and guanosine, the two key intermediates in purine metabolism. After a preliminary screening based on HPLC, three candidate strains with the highest nucleoside degrading rates were selected for further characterization. The tested biological characteristics of candidate strains included acid tolerance, bile tolerance, anti-pathogenic bacteria activity, cell adhesion ability, resistance to antibiotics and the ability to produce hydrogen peroxide. Among the selected strains, DM9218 showed the best probiotic potential compared with other strains despite its poor bile resistance. Analysis of 16S rRNA sequences showed that DM9218 has the highest similarity (99%) to Lactobacillus plantarum WCFS1. The acclimated strain DM9218-A showed better resistance to 0.3% bile salt, and its survival in gastrointestinal tract of rats was proven by PCR-DGGE. Furthermore, the effects of DM9218-A in a hyperuricemia rat model were evaluated. The level of serum uric acid in hyperuricemic rat can be efficiently reduced by the intragastric administration of DM9218-A (P<0.05). The preventive treatment of DM9218-A caused a greater reduction in serum uric acid concentration in hyperuricemic rats than the later treatment (P<0.05). Our results suggest that DM9218-A may be a promising candidate as an adjunctive treatment in patients with hyperuricemia during the onset period of disease. DM9218-A also has potential as a probiotic in the prevention of hyperuricemia in the normal population.     

Isolation and characterization of DM40 and DM43, two snake venom metalloproteinase inhibitors from Didelphis marsupialis serum

From Didelphis marsupialis serum, two antihemorrhagic proteins were isolated by DEAE-Sephacel, Phenyl-Sepharose and Superdex 200 and characterized. Their masses by mass spectrometry were 40?318 AMU for DM40 and 42?373 and 43?010 AMU for DM43, indicating the presence of isoforms for the last. Molecular masses of 44.8 and 47.3 were obtained by SDS–PAGE, respectively for DM40 and DM43. Both inhibitors showed isoelectric points lower than 3.5 and glycosylation percentages varying from 20.5 to 29.0%, as estimated by chemical deglycosylation and amino acid analysis. N-terminal sequences of the first 17 residues of DM40 and DM43 were identical except for the exchange of R9 for P9. Both were homologous to oprin, a similar inhibitor from Didelphis virginiana serum. No evidence of complex formation between DM40 and DM43 was observed either by native PAGE or gel filtration chromatography. In addition to the antihemorrhagic activity, DM40 and DM43 inhibited the hydrolysis of casein, fibrinogen and fibronectin by Bothrops jararaca venom. DM43 also showed antilethal, antiedematogenic and antihyperalgesic activities. None of the inhibitors showed enzymatic activity on casein. Both proteins formed stable complexes with jararhagin and inhibited its hemorrhagic effect as well as the enzymatic activity of this toxin on fluorogenic substrate.     

Functional genomics of dichloromethane utilization in Methylobacterium extorquens DM4

Dichloromethane (CH(2)Cl(2) , DCM) is a chlorinated solvent mainly produced by industry, and a common pollutant. Some aerobic methylotrophic bacteria are able to grow with this chlorinated methane as their sole carbon and energy source, using a DCM dehalogenase/glutathione S-transferase encoded by dcmA to transform DCM into two molecules of HCl and one molecule of formaldehyde, a toxic intermediate of methylotrophic metabolism. In Methylobacterium extorquens DM4 of known genome sequence, dcmA lies on a 126 kb dcm genomic island not found so far in other DCM-dechlorinating strains. An experimental search for the molecular determinants involved in specific cellular responses of strain DM4 growing with DCM was performed. Random mutagenesis with a minitransposon containing a promoterless reporter gfp gene yielded 25 dcm mutants with a specific DCM-associated phenotype. Differential proteomic analysis of cultures grown with DCM and with methanol defined 38 differentially abundant proteins. The 5.5 kb dcm islet directly involved in DCM dehalogenation is the only one of seven gene clusters specific to the DCM response to be localized within the dcm genomic island. The DCM response was shown to involve mainly the core genome of Methylobacterium extorquens, providing new insights on DCM-dependent adjustments of C1 metabolism and gene regulation, and suggesting a specific stress response of Methylobacterium during growth with DCM. Fatty acid, hopanoid and peptidoglycan metabolisms were affected, hinting at the membrane-active effects of DCM due to its solvent properties. A chloride-induced efflux transporter termed CliABC was also newly identified. Thus, DCM dechlorination driven by the dcm islet elicits a complex adaptive response encoded by the core genome common to dechlorinating as well as non-dechlorinating Methylobacterium strains.     

对双歧杆菌DM9227株的实验研究 Ⅲ.双歧杆菌DM9227株与蜡样芽胞杆菌DM423株共生关系的初步研究

本文对厌氧的双歧杆菌DM9227株与需氧的蜡样芽胞杆菌DM423株的共生关系进行了初步研究。将DM9227株与DM423株分别单独及按一定比例等量混合接种于BS肉汤内进行培养,间隔一定时间检测两菌在培养基内菌数的消长情况。结果表明DM423株与DM9227株之间呈偏生关系,即DM423株对DM9227株有促进作用,且在两菌比例适宜(1:100)情况下促进作用更明显,而DM9227株对DM423株有抑制作用。进一步将接种DM423株的Nb琼脂平板与接种DM9227株的BS琼脂平板在普通环境下一起密闭培养,可见厌氧的DM9227株生长良好,提示DM423株可能是通过消耗氧气,降低培养基的Eh,从而促进DM9227株生长的。     

女性糖尿病患者合并尿路感染大肠埃希菌耐药性分析

目的 回顾性分析女性糖尿病(DM)合并尿路感染( UTI)大肠埃希菌的耐药情况及产超广谱β-内酰胺酶(ESBLs)的发生率,以指导临床合理选择抗菌药物.方法 对近4年在浙江大学医学院附属第二医院确诊DM合并UTI女性患者的中段尿标本中分离出的95株大肠埃希菌进行耐药性分析,用纸片扩散法表型确证试验检测ESBLs,以女性非糖尿病患者为对照组,并以年份进行分组分析.结果 95株大肠埃希菌ESBLs阳性率为40.0％,明显高于对照组,糖尿病组对氨苄西林、环丙沙星、左氧氟沙星耐药率较高,均＞60.0％,对环丙沙星、左氧氟沙星、头孢曲松、头孢唑林、头孢吡肟、头孢呋辛耐药率明显高于对照组,早期组与近期组的产ESBLs率及耐药率差异无统计学意义.结论 女性糖尿病伴尿路感染大肠埃希菌对多种抗菌药物的耐药率较高,临床应根据药敏试验结果合理使用抗菌药物.     

The correlation between CT features and insulin resistance levels in patients with T2DM complicated with primary pulmonary tuberculosis

The aim is to investigate the correlation between computed tomography (CT) features and insulin resistance levels in patients with type 2 diabetes mellitus (T2DM) complicated with primary pulmonary tuberculosis (PTB). Nearly, 268 untreated PTB patients complicated with T2DM were divided into two groups according to the optimal cutoff value of HOMA-IR score for the Chinese population: HOMA-IR ≤ 2.69 (Group I: 74 patients), >2.69 (Group II: 194 patients). The basic characteristics and changes of CT manifestations were analyzed. In the two groups, the detection rate of large segmented leafy shadow was 39.2% and 78.9%; the air bronchogram sign detection rate was 40.5% and 80.9%; the discovery rate of mouth-eaten cavity was 33.8% and 73.7%; the thin-walled cavity detection rate was 2.7% and 16.0%; the rate of multiple cavities was 35.1% and 69.6%; and bronchial tuberculosis was found in 4.1% and 35.6%, respectively. The detection rates of lesions in Group II were significantly higher than in Group I (p < .05). HOMA-IR was found independently associated with large segmented leafy shadow, air bronchial sign, thin-walled cavity, and bronchial tuberculosis. The level of insulin resistance can effectively reflect the severity of PTB patients with T2DM. CT scan can directly provide image information in clinics. These two examinations can guide clinicians to accurately formulate subsequent treatment plans.