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1.
铜绿假单胞菌噬菌体PaP1生物学特性的研究   总被引:7,自引:2,他引:5  
目的确定铜绿假单胞菌噬菌体PaP1的形态大小、核酸类型、裂菌特性、最佳感染复数和一步生长曲线等基本生物学特性.方法对CsC1梯度离心纯化后的噬菌体PaP1颗粒进行电镜观察;提取PaP1基因组核酸,通过限制性内切酶图谱分析其核酸类型;制备PaP1的单个噬斑,观察噬斑特点;按照感染复数(MOI)分别为0.000 1、0.001、0.01、0.1、1和10加入噬菌体纯培养液和宿主菌,37℃160 r/min培养3.5 h后测定噬菌体滴度;加入噬菌体及宿主菌使MOI=10,37℃温育15 min后进行一步生长实验,于0时刻和每隔10min取样50 μl测定上清中噬菌体滴度.结果PaP1噬菌体头部呈多面体立体对称,直径约70 nm ,无囊膜,有一个约60 nm长的尾;PaP1噬斑直径约2mm,圆形透明;当MOI为0.01时PaP1感染其宿主菌产生的子代噬菌体滴度最高;根据一步生长实验结果绘制出了一步生长曲线.结论PaP1属于肌尾科裂菌性噬菌体,其基因组为双链DNA分子;最佳感染复数为0.01,感染宿主菌的潜伏期是20 min,爆发期是40 min,平均爆发量约为65.  相似文献   

2.
目的:溶原性噬菌体在宿主菌基因组中的整合和切割作用介导基因在宿主菌间的水平转移.文中研究铜绿假单胞菌噬菌体PaP3的溶原化机制及生物学特性,为阐明噬菌体介导的基因转移和由此而产生的生物多样性提供实验依据. 方法:在不同的条件下利用该噬菌体感染其宿主菌-铜绿假单胞菌PA3,制备溶原菌基因组DNA,用在噬菌体基因组中没有酶切位点的Pst Ⅰ进行酶切,通过脉冲场电泳图谱确定最佳的溶原化条件.并通过噬菌体效价测定噬菌体PaP3对温度、PH值、离子强度及柠檬酸钠浓度等理化因素的敏感性. 结果:噬菌体PaP3的最佳溶原化培养条件为37℃,在NZYM培养基培养铜绿假单胞菌PA310h后,以20:1(宿主菌数目:噬菌体数目)的比例加入噬菌体PaP3感染24h.噬菌体PaP3对温度有一定的耐受性,对pH的适应范围较广,Ca2+与Mg2+可使PaP3的效价增加,而柠檬酸钠可抑制噬菌体生长. 结论:通过溶原菌基因组DNA的酶切确定了噬菌体PaP3的最佳的溶原化条件,并在基因水平上证明PaP3为溶原性噬菌体,在不同的理化因素下具有不同的稳定性.  相似文献   

3.
肠出血性大肠埃希菌O157噬菌体的生物学特性   总被引:1,自引:1,他引:0  
目的:分离并鉴定肠出血性大肠埃希菌O157噬菌体,对其生物学特性进行研究,为开发抗肠出血性大肠埃希菌O157的生物制剂提供实验依据。方法:以肠出血性大肠埃希菌O157为宿主菌,采用噬斑法从环境污水中分离出针对肠出血性大肠埃希菌O157的噬菌体。噬菌体经超滤浓缩后,电镜观察其大小和形态;将宿主菌和噬菌体以不同的比例混合,测定噬菌体的最佳感染复数并观察其一步生长曲线;利用SDS-PAGE分析噬菌体的结构蛋白和非结构蛋白;提取噬菌体基因组,进行酶切电泳分析。结果:电镜显示噬菌体的头部呈球形、直径40 nm,噬菌体的尾部长约80 nm。噬菌体的最佳感染复数为10-2,即当宿主菌和噬菌体之间的比例为1∶100时裂解效率最高。一步生长曲线示噬菌体在裂解宿主菌时,潜伏期约为10 min,爆发期约为30 min,裂解量为130。SDS-PAGE凝胶电泳呈现13种蛋白,相
对分子质量为16 000~22 000。 琼脂糖凝胶电泳显示噬菌体基因组大小约23 000 bp。结论:成功分离并鉴定一株针对肠出血性大肠埃希菌O157的噬菌体,是一种裂解性强、特异性高的毒性噬菌体,肠出血性大肠埃希菌O157噬菌体属于有尾病毒目,管尾噬菌体科。  相似文献   

4.
目的:确定铜绿假单胞菌噬菌体PaP3在宿主菌基因组中的整合位点.方法:利用在噬菌体PaP3基因组中无酶切位点的Pst Ⅰ对溶原性细菌全基因组进行酶切,获得含有噬菌体PaP3全基因组及部分宿主菌DNA序列的大片段;然后进行第二次酶切,获得噬菌体基因组与宿主菌基因组的交界点序列,并进行克隆、测序,鉴定出杂合位点attR.根据λ噬菌体的整合机制,利用PCR反应扩增出另一杂合位点attL,根据测序结果及Blast检索确定attP与attB的位置和DNA序列.结果:经序列比对发现,attP及attB的核心位点分别位于噬菌体PaP3基因组中的t-RNAPro基因及铜绿假单胞菌PA3基因组中的t-RNALys基因中,其核心位点的DNA序列为21 bp(5'-GGTCGTAGGT-TCGAATCCTAC-3.).在核心位点的两侧存在正向重复序列及反向重复序列.结论:该研究为铜绿假单胞菌噬菌体的整合酶及整合机制的研究奠定了基础.  相似文献   

5.
目的 分离鉴定新分枝杆菌噬菌体并研究其生物学特性.方法 以平板法从泥土中分离纯化噬菌体,紫外线诱导法鉴定溶原性,从噬菌斑大小、颗粒形态和限制性内切酶分析三方面比较Chy2、D29、TM4异同;以不同感染复数(MOI)扩增Chy2,测定最佳MOI;通过一步生长实验测出Chy2潜伏期、裂解期和裂解量;采用单斑法测定MOI的裂解谱;检测MOI在不同pH值培养基中裂解耻垢分枝杆菌mc2155的能力.结果 成功分离纯化1株分枝杆菌噬菌体,命名为Chy2,其噬菌斑圆形透明,紫外线诱导法处理宿主菌后不能形成噬菌斑,头部呈椭圆形,长尾,基因组核酸能被双链DNA 内切酶EcoR Ⅰ、HindⅢ、BamH J及Xba Ⅰ切开,大小约49 kb,与D29、TM4差异大;Chy2最佳MOI为9.58×10-5;Chy2—步生长周期为270 min,潜伏期210 min,裂解期60 min,裂解量为23;Chy2能裂解耻垢分枝杆菌mc2 155、结核菌标准株H37Rv、多数临床耐药株;在7H9固体培养基pH值为5.0和7.4时,Chy2均能裂解耻垢分枝杆菌mc2155.结论 Chy2属长尾噬菌体科,基因组为双链DNA,宽噬谱广,是一种潜在的抗结核药物资源.  相似文献   

6.
目的分离鉴定新分枝杆菌噬菌体并研究其生物学特性。方法以平板法从泥土中分离纯化噬菌体,紫外线诱导法鉴定溶原性,从噬菌斑大小、颗粒形态和限制性内切酶分析三方面比较Chy2、D29、TM4异同;以不同感染复数(MOI)扩增Chy2,测定最佳MOI;通过一步生长实验测出Chy2潜伏期、裂解期和裂解量;采用单斑法测定MOI的裂解谱;检测MOI在不同pH值培养基中裂解耻垢分枝杆菌mc2155的能力。结果成功分离纯化1株分枝杆菌噬菌体,命名为Chy2,其噬菌斑圆形透明,紫外线诱导法处理宿主菌后不能形成噬菌斑,头部呈椭圆形,长尾,基因组核酸能被双链DNA内切酶EcoRⅠ、HindⅢ、BamHⅠ及XbaⅠ切开,大小约49 kb,与D29、TM4差异大;Chy2最佳MOI为9.58×10-5;Chy2一步生长周期为270 min,潜伏期210 min,裂解期60 min,裂解量为23;Chy2能裂解耻垢分枝杆菌mc2155、结核菌标准株H37Rv、多数临床耐药株;在7H9固体培养基pH值为5.0和7.4时,Chy2均能裂解耻垢分枝杆菌mc2155。结论 Chy2属长尾噬菌体科,基因组为双链DNA,宽噬谱广,是一种潜在的抗结核药物资源。  相似文献   

7.
目的 通过分离耐碳青霉烯类鲍曼小动杆菌(CRAB)噬菌体,研究其生物学特性,为噬菌体治疗CRAB感染提供实验依据.方法 利用噬菌斑法从医院污水中分离CRAB噬菌体,电子显微镜观察噬菌体的形态特征,提取其基因组行酶切电泳,SDSPAGE分析噬菌体表面衣壳蛋白,测定噬菌体感染复数和耐受突变率,并观察其一步生长曲线.结果 筛选出1株具有较宽裂解谱的无尾双链DNA的CRAB噬菌体,命名为噬菌体AB3.其基因组大小约35 kb,表面主要衣壳蛋白相对分子质量约为35×103.该噬菌体感染宿主菌的潜伏期为20 min,爆发期为60 min,裂解量为350,耐受突变率为2.5×10-10,对pH值耐受范围广,热稳定性好.结论 噬菌体AB3具有较宽的噬菌谱,潜伏期短、裂解量大、耐受突变率低,对理化因素稳定性好,具有临床应用前景.  相似文献   

8.
噬菌体Legendre的生物学特性及抗耐药结核潜力的初步研究   总被引:1,自引:1,他引:0  
目的研究噬菌体Legendre的生物学特性并初步探索其用于抗耐药结核的潜力。方法双层平板法制备Legendre的噬菌斑,观察其特点,纯化噬菌体,电镜观察Legendre形态;提取Legendre基因组,限制性内切酶酶切分析确定其核酸类型;以不同感染复数扩增Legendre,找出最佳MOI和最小MOI;通过一步生长实验找出Legendre潜伏期、裂解期和裂解量;纯化Legendre颗粒,免疫家兔,获得抗血清,通过中和反应实验测定Legendre以及其他8种噬菌体和Legendre抗血清之间的吸附反应常数K值;采用单斑法测定Legendre的宿主谱;检测Legendre对紫外线、温度、氯仿、酒精、酸碱度的耐受性。结果 Legendre的噬菌斑圆形透明,边界清楚,Legendre头部呈多面体立体对称,直径平均为65 nm,尾长平均为215 nm;基因组核酸能被双链DNA内切酶EcoRⅠ,HindⅢ及BamHⅠ切开,大小约65 kb;Legendre最佳MOI为10-4,最小MOI为10-3,Legendre对耻垢分枝杆菌极度易感;Legendre感染宿主菌的潜伏期为180 min,裂解期为120 min,裂解量为13;Legendre K值为697,Legendre抗血清对非对应噬菌体的中和活性有差异,对DNAⅢ、Bo4、Clark、Sedge、Leo高,对TM4、D29中和活性较低;Legendre能裂解耻垢分枝杆菌、结核分枝杆菌标准株、多数临床耐药株;Legendre对紫外线、温度、氯仿、酒精、酸碱度均敏感。结论 Legendre属于长尾噬菌体科,双链DNA噬菌体,抗原性低,宿主谱广,具有抗耐药结核潜力。  相似文献   

9.
目的:以14株阴沟肠杆菌为宿主菌,从环境污水中分离噬菌体,分析其生物学特性,鉴定其分型。方法:采用双层琼脂噬斑法分离并鉴定噬菌体。纯化后的噬菌体经负染法染色,通过电镜观察其大小和形态;提取噬菌体基因组,进行酶切电泳分析;通过裂解谱的分析,确认噬菌体的特异性和裂解宿主菌范围。结果: 成功分离1株裂解性噬菌体,电镜显示噬菌体的头部呈球形,直径约60 nm,尾部长约130 nm。琼脂糖凝胶电泳显示其基因组约40 000 bp,且含多种酶切位点。特异性实验显示其呈现较窄的宿主范围。结论: 分离的阴沟肠杆菌噬菌体(命名为ФEc53)属于有尾病毒目,管尾病毒科,是一种特异性高、裂解性强的毒性噬菌体。  相似文献   

10.
铜绿假单胞菌噬菌体PaP3基因组电转化宿主菌的条件初探   总被引:1,自引:0,他引:1  
目的:研究将铜绿假单胞菌噬菌体PaP3基因组DNA电转入其宿主菌并获得噬斑的基本条件。方法:以铜绿假单胞菌PA3作受体菌,将噬菌体PaP3基因组DNA通过电转化导入受体菌中,研究细胞生长状态、感受态细胞的制备方式、电场强度、DNA浓度和细胞密度等条件对转化效率的影响。结果:在含50μg/ml红霉素的LB培养液中培养宿主菌14~16 h,以100 mmol/L蔗糖溶液为介质,在25℃条件下制备感受态并使其浓度达到1011/ml,电转参数为12 kV/cm,300Ω,25μF,在此组条件下能获得较高的转化效率,最高可达2.1×103pfu/μg的DNA。结论:确定了一组电转条件,成功地将铜绿假单胞菌噬菌体完整基因组导入PA3中,并形成噬斑,为铜绿假单胞菌噬菌体的深入研究奠定了基础。  相似文献   

11.
Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P < 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (>0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P <0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P < 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.  相似文献   

12.
Objective: To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods: SD rats served as both donors and recipients. 4℃ sodium lactate Ringer's was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava (IVC) inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results: Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion: This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.  相似文献   

13.
Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P< 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P< 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure.  相似文献   

14.
FOR anesthesiologis s ,treatingpostoperativepainhas alwaysbeen a problem.Althoughopioidshave been provedtobe effective,theirsideeffectscouldnotbeignored.With thedevelopmentofscienceand pharmacology,many drugs with aspectsof satisfactoryanalgesicefficacyand couldbe welltoleratedby patientshave been developed.And lornoxicamisone of them, which isa non-steroidalanti-inflammatorydrug (NSAID ), with analgesic, anti-infl-ammatory,andantipyreticproperties.Itseliminationhalf-time(3 to 5 hours) isle…  相似文献   

15.
目的:评价使用安心颗粒对急诊经皮冠状动脉介入术(PPCI)术后生活质量的影响.方法:将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组(术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次)和对照组(仅接受基础药物治疗).所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表(MIDAS)、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果:入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异(P>0.05);出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低(P<0.05);组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低(P<0.05).两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血(P>0.05).两组发生轻度血小板减少症的患者数比较无差异(P>0.05).结论:PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.  相似文献   

16.
Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P<0.01);the MAP decreased(P<0.01)and the HR increased drastically(P<0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients.  相似文献   

17.
Objective:To probe into the influence of changes of ovarian hormones on the pathogenesis of the specific sub-type premenstrual syndrome(PMS)and reveal partial microcosmic mechanisms of adverse flow of liver-qi.Methods:Estradiol(E2)and progesterone(P)levels in serum were determined at different phases of menstrual cycle by radioimmunoassay.Results:In the group of PMS with adverse flow of liver-qi.the secretive peak value Of E2 and P at the follicular phase significantly decreased,and the secretive peak value at the luteal phase did not come into being.Conclusions:Low E2 and P secretive peak at the follicular phase and absence of secretive peak at the luteal phase is one of the microcosmic mechanisms of PMS with adverse flow of liver-qi.One of the pathophysiologic mechanisms of specific sub-type PMS is probably the continuous low level of E2and P.  相似文献   

18.
Real-time three-dimensional echocardiography (RT3DE)is a new ultrasound technique that enables dynamic threedimensional visualization and quantification of the heart in real time. Investigation of feasibility and methodology of RT3DE in determining left ventricular (LV) and right ventricular (RV) volumes, RT3DE was performed in 35 normal adults using Philips SONOS 7500 system with a 2-4 MHz matrix array transducer. The 60°×60° "pyramid" volume database was obtained and analyzed on a TomTec echo workstation. Both LV and RV volumes were calculated with four 3DE methods (i.e. apical 2, 4, 8, and 16-plane) through manually tracing ventricular endocardial borders in end diastole and end systole. Stroke volumes were then calculated. LV volume was also measured by 2DE Simpson's rule using GE VIVID 7 ultrasound machine.  相似文献   

19.
Increasing maternal age is the only etiological factor unequivocally linked to Down's syndrome in humans. The occurrence rate of newborns with Down's syndrome is about 1/220 in women over 35 years old. However, the occurrence rate in embryos fertilized in vitro, of the elder woman is unclear. Using FISH we screened the number of chromosome 21 in preimplanted embryos of 5 elderly women (average age, 38.4 years) to study the feasibility and necessity of screening trisomy 21 in embryos in patients over 35 years old at the in vitro fertilization (IVF) center.  相似文献   

20.
A clinical guideline for the therapeutic interventions of integrative medicine may be defined as a written document which states a series of recommendations on therapeutic interventions of integrative medicine for a special disease or condition. The guideline may provide assistance to medical professionals in making clinical decisions aimed at improving the clinical outcome of patients and reducing the costs of medical care(~'4~. Recommendations issued by a guideline should be based on the best available evidence in both Western and Chinese medicine. For fulfilling this purpose, the development of clinical guidelines for therapeutic interventions in the field of integrative medicine should follow scientific principles and undergo a rigorous processes.  相似文献   

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