共查询到17条相似文献，搜索用时 187 毫秒
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以Caco-2细胞作为体外模型研究芽孢杆菌对细胞黏附、细胞存活率及细胞膜完整性的影响.采用荧光标记法探究芽孢杆菌、大肠杆菌K88和猪霍乱沙门菌对Caco-2细胞的黏附特性,并通过排斥、竞争和置换试验测定其对病原菌黏附的阻断作用.采用台盼蓝染色法测定Caco-2细胞存活率和细胞培养上清乳酸脱氢酶(LDH)活性来反映细胞膜的完整性.结果表明:芽孢杆菌对Caco-2细胞的黏附率均低于病原菌、且对病原菌的黏附无阻断作用,大部分芽孢杆菌不会影响细胞存活率及细胞膜的完整性,对细胞无毒. 相似文献
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选用断奶仔猪肠道中的大肠杆菌K88和猪霍乱沙门菌作为指示菌。杀菌性能的测定采用最低抑菌浓度（MIC）和最小杀菌浓度（MBC）,并绘制杀菌曲线。原子吸收光谱仪测定Cu2＋在肉汤和生理盐水中的释放量;透射电镜观察细菌细胞壁的变化;全自动生化分析仪测定细菌胞内酶的活性;通过K＋电极测定K＋释放量;采用SP-2型溶氧仪测定菌体悬浮液中的溶氧量。结果显示,载铜蒙脱石对E.coli K88的MIC为64mg/L,MBC为256mg/mL;对S.choleraesuis的MIC为128mg/L,MBC为512mg/L。而蒙脱石未显抗菌活性。透射电镜下观察细菌与载铜蒙脱石作用后形态发生了变化,细菌细胞膜受损,内容物外漏;细菌胞内酶活性结果显示,胞内酶的大量外漏,与对照组相比,均差异极显著（P〈0.01）;大量自由的K＋从细菌细胞内释放出来;呼吸代谢结果显示,载铜蒙脱石抑制了细菌呼吸代谢的三羧酸循环途径。结果表明,载铜蒙脱石具有强大的杀菌作用。 相似文献
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以蒙脱石（MMT）为原料，通过阳离子交换反应合成载铜蒙脱石（MMT-Cu）。为探讨载铜蒙脱石对肠粘膜屏障功能的影响，采用体外培养的单层Caco-2细胞模型为研究对象，以细菌易位数量和肠绒毛损伤程度做为指标进行研究。结果表明：MMT-Cu可明显减少（P〈0．01）E．coilK88、S．choleraesuis侵入到Caco-2细胞内的数量，与对照组相比，下降了2logCFU／mL～3log CFU／mL；并能显著降低（P〈0．01）LDH的释放量。扫描电子显微镜下观察可见，加入MMT-Cu一段时间后，当E．coil K88和S．choleraesuis粘附Caco-2细胞时，微绒毛依旧排列整齐、致密，可见肠上皮细胞保持完好。结果表明，MMT-Cu对肠粘膜具有屏障作用，可作为一种消化道粘膜保护剂。 相似文献
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嗜酸乳杆菌和两歧双歧杆菌体外粘附Caco-2细胞及其对病原菌粘附性能的影响 总被引：1，自引：0，他引：1
以Caco-2细胞作为体外模式,观察嗜酸乳杆菌、两歧双歧杆菌、大肠杆菌K88和猪霍乱沙门氏菌对Caco-2细胞的粘附特性,并探讨嗜酸乳杆菌和两歧双歧杆菌的抗粘附作用。结果表明,所试4种细菌菌株均表现出很强的粘附Caco-2细胞的特性;粘附抑制试验表明,无论在排斥试验、竞争试验还是置换试验,嗜酸乳杆菌或两歧双歧杆菌均能明显抑制大肠杆菌K88和猪霍乱沙门氏菌的粘附;杀菌试验表明,嗜酸乳杆菌或两歧双歧杆菌上清液均能显著抑制病原菌的生长,但上清液用胰蛋白酶、蛋白酶K、乳酸脱氢酶处理后,杀菌作用明显降低,表明杀菌作用是乳酸和蛋白质样物质共同作用的结果。 相似文献
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几株益生乳酸菌对Caco-2细胞的黏附及其对致病菌黏附的影响 总被引：1，自引：0，他引：1
以Caco-2细胞作为体外模型研究几株乳酸菌的黏附性能及其对大肠杆菌K88和鼠伤寒沙门氏菌的黏附抑制性能。采用荧光标记法评价这几株乳酸菌的黏附性能,并通过竞争、排斥和置换试验检测其对上述2株病原菌黏附的抑制作用。结果表明:1)除了乳酸乳球菌外,其他乳酸菌对Caco-2细胞的黏附率均高于这2株病原菌,且黏附率为乳杆菌(Lactobacillus)>肠球菌>致病菌>乳球菌。2)来源于健康鸡肠道的乳杆菌与分离于人肠道的鼠李糖乳杆菌(Lacto-bacillus rhamnosus)和食果糖乳杆菌(Lactobacillus fructivorans)的黏附率接近。3)大部分乳酸菌菌株能通过置换作用抑制大肠杆菌K88和鼠伤寒沙门氏菌的黏附。结果提示,这几株乳酸菌对肠上皮细胞均有较高的黏附率,尤其是乳杆菌,且它们的黏附有菌属特异性。乳酸菌抑制上述2种病原菌的黏附主要通过置换方式,但没有菌属特异性,且与其自身的黏附力也没有必然的联系。 相似文献
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为研究肠炎沙门菌SEF14菌毛对肠上皮细胞的黏附作用,本试验利用肠炎沙门菌50336株、突变株50336△sefA、50336△sefD以及互补株50336△sefA (pBRA)、50336△sefD (pACYCD)与肠上皮细胞系细胞(IPEC-J2和Caco-2)进行了黏附作用.结果显示:上述菌株均能与IPEC-J2、Caco-2细胞进行有效黏附,并且随时间延长黏附数量有所增多,相同时间各菌株与IPEC-J2细胞的黏附数量明显多于Caco-2细胞;但细菌和细胞共感染1和4h后,肠炎沙门菌野生株、相应的突变株和互补株与IPEC-J2和Caco-2细胞黏附的数量差别很小,未到达显著差异水平(P＞0.05).结果表明:SEF14菌毛并不特异性介导肠炎沙门菌与肠上皮细胞系IPEC-J2和Caco-2的黏附作用,或者不是介导黏附作用的主要因子. 相似文献
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《中国兽医学报》2014,(6):923-929
为研究肠炎沙门菌SPI-19编码的Hcp基因在肠炎沙门菌感染中的毒力作用,利用Red同源重组系统对2株肠炎沙门菌(国内标准株50336和国际参考株SD-2)SPI-19的Hcp基因进行敲除,成功构建了50336ΔHcp和SD-2ΔHcp基因缺失株,并构建了回补株50336ΔHcp/pHcp和SD-2ΔHcp/pHcp。分析比较缺失株与野生株对人肠上皮细胞系Caco-2黏附和侵袭能力,以及在鸡巨噬细胞HD11的存活能力。结果显示:缺失Hcp基因后,肠炎沙门菌50336对Caco-2细胞黏附和侵袭数量分别下降39.1%和47.9%;SD-2对Caco-2细胞黏附和侵袭数量分别下降46.5%和58.9%。吞噬作用2h后,50336ΔHcp和SD-2ΔHcp与野生株相比在HD11的存活量下降了35.7%和37.2%,差异显著。通过Real Time-PCR试验分析,与野生株相比,Hcp基因缺失后fliC、sefA、ompA,ompC这4个重要粘附因子编码基因的表达量显著下降。试验表明,肠炎沙门菌SPI-19编码的Hcp基因对肠炎沙门菌的毒力具有增强作用。 相似文献
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《中国兽医学报》2015,(4):585-591
从发病鸡的粪便中分离出具有多重耐药性的大肠杆菌O18和鸡白痢沙门菌O2,检测多黏菌素E的最小抑菌浓度(MIC)和抗生素后效应(PAE),测定多黏菌素E接触过的细菌各组乳酸脱氢酶(LDH)和γ-谷氨酰基转移酶(γ-GT)活性变化、电镜观察细胞膜形态、巨噬细胞吞噬细菌数量和细菌对Caco-2的黏附力。多黏菌素E作用后,菌液中LDH和γ-GT活性显著性增高(P0.01),细菌胞膜出现破损或缺失,细菌形态改变,被巨噬细胞吞噬的菌量明显增多(P0.01),细菌对Caco-2的黏附力显著下降(P0.01)。多黏菌素E对鸡源性多重耐药菌株存在PAE,推测其产生机制为破坏细菌细胞膜,改变细菌形态,促进巨噬细胞对细菌的吞噬能力增强,降低细菌对细胞黏附力。 相似文献
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《中国兽医学报》2016,(1):40-47
通过革兰染色、菌落形态观察、生化分析鉴定、牛津杯抑菌试验、Caco-2细胞黏附试验对分离到的6株乳酸产生菌进行研究。结果显示:经16SrDNA序列测定,比对分析6株乳酸产生菌与鼠李糖乳杆菌、乳酸乳球菌乳亚种、唾液乳杆菌、乳链球菌、哥伦比亚肠球菌和鼠乳杆菌高度同源。6株乳酸菌抑菌试验检测显示:对大肠杆菌、沙门菌、蜡样芽胞杆菌和金黄色葡萄球菌具有很强的抑菌效应,以CM3菌株的抑菌效果最强。同时,这6株乳酸菌对Caco-2细胞均有一定的黏附能力。结果表明:6株番鸭肠道乳酸产生菌能够黏附于肠道模型Caco-2细胞上并具有较强的抑菌活性,但其黏附性能及保护机制还有待进一步研究。 相似文献
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The aim of this research was to determine the antibacterial properties and mechanisms of Cu(II)-exchanged montmorillonite (MMT-Cu) in vitro. Escherichia coli ATCC K88 and Salmonella choleraesuis ATCC 50020 were chosen as indicators of intestinal tract pathogenic bacteria in weanling pigs. The antibacterial activity of MMT-Cu and MMT were evaluated by determining the minimum inhibitory concentrations (MICs) using two-fold serial dilutions in MH broth, and the amount of Cu2+ released into the broth was measured by an atomic absorption technique. The rate of oxygen consumption was measured using a SP-II-type oxygen electrode analyzer; the structural integrity of cell walls of bacteria was observed by transmission electron microscope (TEM); enzymatic activity of bacteria was examined with a semi-automatic biochemical analyzer. The results showed that MMT-Cu inhibited the growth of E. coli K88 and S. choleraesuis, and the MICs were 1024 and 2048 microg/ml, respectively. The amount of Cu2+ released into the broth was in the range 6.51-45.65 microg/ml. Nevertheless, both tested bacteria still grew in broth containing 32,768 microg/ml of MMT. Treatment with MMT-Cu could lead to significant release of intracellular enzymes from the tested bacteria. Data from oxygen consumption of bacteria showed that MMT-Cu could inhibit the TCA pathway of the bacterial respiration metabolism. These results show that MMT-Cu has an antibacterial activity. 相似文献
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Vo AT van Duijkeren E Fluit AC Hendriks HG Tooten PC Gaastra W 《Comparative immunology, microbiology and infectious diseases》2007,30(1):11-18
The in vitro pathogenicity of Salmonella enterica serovar Typhimurium phage type (pt) 90 and pt 506 (also known as DT 104) isolates from human and porcine origin was studied in adhesion and invasion assays to the human cell line Caco-2 and the porcine cell line IPI-2. Interleukin-8 (IL-8) production by these two cell lines in response to stimulation by the two Salmonella phage types was also measured. Generally, Salmonella Typhimurium pt 506 and pt 90 adhered to and invaded Caco-2 cells and IPI-2 cells equally well. The release of IL-8 by Caco-2 cells or by IPI-2 cells was similar, independent of the Salmonella phage type used for stimulation of the cells. These data suggest that Salmonella Typhimurium pt 90 has a similar ability to cause Salmonella infections as Salmonella Typhimurium DT 104. 相似文献
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嗜水气单胞菌体外粘附Caco-2细胞对细胞膜生物学特性的影响 总被引：1，自引：0，他引：1
采用Caco-2细胞培养模型，研究了嗜水气单胞菌粘附Caco-2肠上皮细胞后时其活力、细胞膜磷脂酶A2（PLA2）、胞浆游离钙浓度、膜通透性和膜流动性的影响。结果显示，细菌粘附后1h，肠上皮细胞活力显著下降，PLA2活性和胞浆游离钙浓度显著增加，细胞外LDH含量和细胞损伤率显著升高（膜通透性异常增加），肠上皮细胞膜荧光，偏振度、膜脂微粘度显著增加（膜流动性降低），且上述指标均随着粘附时间的延长而持续升高或降低。 相似文献
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纳米载铜蒙脱石对断奶仔猪生长、肠道菌群及其肠黏膜形态的影响 总被引：6，自引：0，他引：6
选用128头健康“杜长大”三元杂交断奶仔猪,随机分为对照组、CuSO4组、纳米蒙脱石(MMT)组和MMT-Cu组,分别饲喂基础日粮(对照组)、基础日粮+78 mg/kg Cu2+(CuSO4.5H2O,相当于MMT-Cu中Cu2+的量)、基础日粮+2.0 g/kgMMT、基础日粮+2.0 g/kgMMT-Cu。结果表明,与对照组相比,MMT-Cu组能显著提高(P<0.05)断奶仔猪的平均日增重、饲料转化效率及小肠绒毛高度、绒毛高度与隐窝深度的比值,显著降低(P<0.05)腹泻率及小肠、结肠内容物中大肠杆菌和沙门氏菌的数量;而MMT组也显著降低(P<0.05)仔猪腹泻率,提高(P<0.05)小肠绒毛高度和绒毛高度与隐窝深度的比值。与MMT组或CuSO4组相比,MMT-Cu组能显著(P<0.05)提高断奶仔猪的平均日增重和饲料转化效率(P<0.05),显著降低了(P<0.05)小肠和结肠内容物中大肠杆菌和沙门氏菌的数量。 相似文献
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纳米载铜蒙脱石对断奶仔猪生长、消化性能及二糖酶活性的影响 总被引：1，自引：0，他引：1
取128头健康"杜长大"三元杂交断奶仔猪,随机分为4组,每组32头。分别饲喂基础日粮(对照组)、基础日粮+3.0g/kg纳米蒙脱石(MMT)、基础日粮+3.0g/kg纳米载铜蒙脱石(MMT-Cu)及基础日粮+117mg/kgCu2+。比较研究MMT-Cu对断奶仔猪生长、消化和肠黏膜二糖酶活性的影响。结果表明:饲料中添加3.0g/kgMMT-Cu,能显著(P<0.05)提高断奶仔猪的平均日增重和饲料转化效率;显著提高饲料干物质(P<0.05)、粗蛋白(P<0.05)、粗脂肪(P<0.05)的表观消化率和十二指肠内容物中总蛋白水解酶(P<0.05)、脂肪酶(P<0.05)、淀粉酶(P<0.05)的活性。与对照组相比,添加MMT组十二指肠内容物中脂肪酶、淀粉酶活性升高显著(P<0.05)。二糖酶活性研究表明,添加3.0g/kgMMT-Cu组仔猪空肠黏膜麦芽糖酶、蔗糖酶和乳糖酶活性均显著高于(P<0.05)对照组和CuSO4组。 相似文献
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A mixed infection with rotavirus and 3 different Campylobacter jejuni strains was analysed in Caco-2 cells, a cell line highly susceptible to these pathogens. The results obtained showed no influence of the virus preinfection on the Campylobacter jejuni adhesion or internalisation in Caco-2 cells. Confocal laser scanning microscopy of mixed infected cells confirmed these results. The data from the present study indicate that specific rather than nonspecific mechanisms are involved in the interaction between rotavirus, campylobacter and host cells. 相似文献
17.
Duan Q Zhou M Zhu X Bao W Wu S Ruan X Zhang W Yang Y Zhu J Zhu G 《Veterinary microbiology》2012,160(1-2):132-140
Bacterial flagella contribute to pathogen virulence; however, the role of flagella in the pathogenesis of F18ab E. coli-mediated swine edema disease (ED) is not currently known. We therefore evaluated the role of flagella in F18ab E. coli adhesion, invasion, biofilm formation, and IL-8 production using an in vitro cell infection model approach with gene-deletion mutant and complemented bacterial strains. We demonstrated that the flagellin-deficient fliC mutant had a marked decrease in the ability to adhere to and invade porcine epithelial IPEC-J2 cells. Surprisingly, there was no difference in adhesion between the F18 fimbriae-deficient ΔfedA mutant and its parent strain. In addition, both the ΔfedA and double ΔfliCΔfedA mutants exhibited an increased ability to invade IPEC-J2 cells compared to the wild-type strain, although this may be due to increased expression of other adhesins following the loss of F18ab fimbriae and flagella. Compared to the wild-type strain, the ΔfliC mutant showed significantly reduced ability to form biofilm, whereas the ΔfedA mutant increased biofilm formation. Although ΔfliC, ΔfedA, and ΔfliCΔfedA mutants had a reduced ability to stimulate IL-8 production from infected Caco-2 cells, the ΔfliC mutant impaired this ability to a greater extent than the ΔfedA mutant. The results from this study clearly demonstrate that flagella are required for efficient F18ab E. coli adhesion, invasion, biofilm formation, and IL-8 production in vitro. 相似文献