白色念珠菌粘附口腔粘膜上皮细胞配体的初步研究

目的：研究白色念珠菌对口腔粘膜上皮细胞的粘附配体,方法：采用体外法测定白色念珠菌对口腔上皮细胞的粘附数量,结果：D－甘露糖预作用于上皮细胞之后,可以使白色念珠菌粘附下降,刀豆素A及绿慕安预作用于白色念珠菌,可以减少白色念珠菌对上皮细胞的粘附,结论：白鬼念珠菌粘附感染与其表面甘露糖结构有关。     

白色念珠菌和热带念珠菌对人肺上皮细胞的粘附作用及其差异性比较

目的探讨白色念珠菌和热带念珠菌对人肺上皮细胞的粘附作用及其差异性.方法将白色念珠菌和热带念珠菌临床分离株在体外与人肺上皮细胞共同作用,经革兰染色后,在倒置显微镜下观察念珠菌对肺上皮细胞的粘附数.结果念珠菌粘附的肺上皮细胞与浓度和时间有依赖关系.菌液浓度在5×103CFU/ml至5×107CFU/ml范围内,念珠菌对肺上皮细胞的粘附作用随念珠菌浓度的增加而增强.白色念珠菌对肺上皮细胞的粘附数比热带念珠菌的粘附数要高.来自痰、尿标本的同一种念珠菌对人肺上皮细胞的粘附数无明显差异.结论念珠菌对人肺上皮细胞的粘附是一种特异性的粘附,临床标本来源的白色念珠菌粘附宿主细胞的能力比热带念珠菌强.     

白色念珠菌胃癌株对细胞粘附作用的研究

研究白色念珠菌 (candidaalbicans)正常人口腔株与胃癌株对口腔粘膜细胞及肺上皮细胞的粘附性能。将白色念珠菌与正常人口腔颊粘膜细胞或培养的人肺上皮细胞于 37℃温育一定时间后 ,计算每个细胞粘附白色念珠菌数。白色念珠菌胃癌株对两类细胞粘附能力均较正常人口腔株强 ,其差异有显著性 (p <0 .0 1)。粘附性是致病菌侵袭力的重要机制 ,粘附性增强是白色念珠菌由正常微生物群成员转变为条件致病菌的重要条件。     

白念珠菌粘附上皮细胞的机制

本文总结了近年来白念珠菌细胞表面疏水性、侵袭性酶、以及表面甘露糖、蛋白质等对上皮细胞粘附的研究进展,提出了阻断白念珠菌粘附的方式。     

乳杆菌DM8909对阴道上皮细胞粘附现象的初步研究

本文分析了乳杆菌DM8909菌株及自阴道分离的肠杆菌、葡萄球菌、白色念珠菌对阴道上皮细胞的粘附能力。结果显示,在正常阴道酸性条件(pH3.5—4.5)下,DM8909菌株对阴道上皮细胞的粘附能力明显高于肠杆菌(P<0.01)、葡萄球菌(P<0.01)、白色念珠菌(P<0.01);随pH增加,DM8909粘附能力降低,肠杆菌、葡萄球菌、白色念珠菌粘附能力增强;DM8909菌株能较强地抑制肠杆菌、葡萄球菌对阴道上皮细胞的粘附。本文提示,乳杆菌粘附形成的空间占位是防止其他菌对阴道组织附着的一个重要的保护性机制。     

白色念珠菌对上皮细胞粘附性的观察

念珠菌性口腔炎是口腔的常见疾病 ,病原体以白色念珠菌多见。据报道 [1、2 ] ,口腔粘膜上皮细胞对念珠菌的粘附性与上皮细胞的分化程度有关。我们从健康人的口腔粘膜获取上皮细胞标本 ,与白色念珠菌混合孵育后 ,应用巴氏染色方法来观察念珠菌对各类上皮细胞的粘附性能。1　材料与方法1.1　粘膜上皮细胞的制备　选择 2 0例健康人 (男性 10名 ,女性 10名 ,年龄 30～ 4 0岁 ) ,用无菌棉拭子在口腔粘膜表面反复轻擦 ,将棉试子浸入无菌磷酸盐缓冲液内 (PBS;0、0 1mol/ L ,p H7、2 ) ,摇动棉拭子使上皮细胞落于 PBS中 ,细胞悬液离心 15 min(10…     

钛合金和钴铬合金表面白色念珠菌粘附的研究

目的比较钛合金(Ti-6Al-4V)和钴铬合金(Chromium-Cobaltalloy)表面白色念珠菌粘附能力的大小,研究表面粗糙度与细菌粘附的关系。方法将不同表面粗糙度的钛合金和钴铬合金试件进行白色念珠菌体外粘附试验,采用菌落形成计数法测定试件表面的细菌粘附量。结果各钛合金试件组的细菌粘附量均少于相同表面粗糙度的钴铬合金试件组,两种金属试件表面的细菌粘附量均随表面粗糙度的增大而增加。结论钛合金较钴铬合金更能减少由白色念珠菌引起的义齿性口炎等并发症,同时修复体表面严格的研磨抛光也能有效减少这些并发症。     

白带中白色念珠菌致病性的研究

目的探讨女性生殖道分泌物(白带)中白色念珠菌的致病性,评价其在白带中分离的临床意义.方法对重庆医科大学第二临床学院2002年1月～2003年12月300株白带分离的白色念珠菌进行蛋白酶测定,并从蛋白酶活力高、中、低中分别选2株作血管内皮细胞毒力和粘附性测定.结果 300株白色念珠菌全部检出蛋白酶,其中蛋白酶活力高为249株,占83.0%;中等活力38株,占12.7%;低等活力13株,占4.3%.细胞毒力试验表明蛋白酶活力高,细胞毒性强,蛋白酶活力与毒力呈正相关(r=0.9946、P＜0.01);细胞粘附试验表明蛋白酶活力高,粘附能力强,蛋白酶活力与粘附呈正相关(r=0.9944、P＜0.01).结论蛋白酶是白色念珠菌重要的毒力因子,蛋白酶活力可直接反映其毒力,蛋白酶活力与其粘附直接相关.白带中白色念珠菌具有致病性,临床应对其引起的感染密切关注.     

两种树脂基托细菌粘附情况的比较

目的比较BPS注塑树脂和热凝基托树脂表面细菌粘附能力的大小。方法将BPS注塑树脂和热凝基托树脂试件进行细菌体外粘附实验,采用菌落形成单位计数法测定血型链球菌、粘性放线菌和白色念珠菌粘附量的大小。结果培养24h、48h、168h后,各BPS注塑树脂试件组的细菌粘附量均少于热凝基托树脂试件组。结论BPS注塑树脂较热凝基托树脂更能减少血型链球菌、粘性放线菌和白色念珠菌在其表面的粘附。     

白色念珠菌粘附的研究进展

本文论述了白色念珠菌（简称白念菌）粘附的分子机理和实验模型观察,从病原菌和宿主两方面探讨了白念菌感染的发病机理,并从阻断白念菌对宿主细胞的粘附着手,展望防治白念菌感染的新途径和措施。     

PA‐MSHA inhibits proliferation and induces apoptosis through the up‐regulation and activation of caspases in the human breast cancer cell lines

To investigate the effects of PA‐MSHA (Pseudomonas aeruginosa‐mannose sensitive hemagglutinin) on inhibiting proliferation of breast cancer cell lines and to explore its mechanisms of action in human breast cancer cells. MCF‐10A, MCF‐7, MDA‐MB‐468, and MDA‐MB‐231HM cells were treated with PA‐MSHA or PA (Heat‐killed P. aeruginosa) at different concentrations and different times. Changes of cell super‐microstructure were observed by transmission electron microscopy. Cell cycle distribution and apoptosis induced by PA‐MSHA were measured by flow cytometry (FCM) with PI staining, ANNEXIN V‐FITC staining and Hoechst33258 staining under fluorescence microscopy. Western blot was used to evaluate the expression level of apoptosis‐related molecules. A time‐dependent and concentration‐dependent cytotoxic effect of PA‐MSHA was observed in MDA‐MB‐468 and MDA‐MB‐231HM cells but not in MCF‐10A or MCF‐7 cells. The advent of PA‐MSHA changed cell morphology, that is to say, increases in autophagosomes, and vacuoles in the cytoplasm could also be observed. FCM with PI staining, ANNEXIN V‐FITC and Hoechst33258 staining showed that the different concentrations of PA‐MSHA could all induce the apoptosis and G₀–G₁ cell cycle arrest of breast cancer cells. Cleaved caspase 3, 8, 9, and Fas protein expression levels were strongly associated with an increase in apoptosis of the breast cancer cells. There was a direct relationship with increased concentrations of PA‐MSHA but not of PA. Completely different from PA, PA‐MSHA may impart antiproliferative effects against breast cancer cells by inducing apoptosis mediated by at least a death receptor‐related cell apoptosis signal pathway, and affecting the cell cycle regulation machinery. J. Cell. Biochem. 108: 195–206, 2009. © 2009 Wiley‐Liss, Inc.     

In vitro effect of carbohydrates and enteric bacteria on adherence of Candida albicans

The adherence of Candida albicans to any cell is considered essential in the process that leads to colonization. Our objective in this study was to evaluate the effect of different carbohydrates and the presence of lactobacilli and Escherichia coli on the in vitro adherence of Candida albicans. The adherence to buccal epithelial cells was higher when growing at concentrations of galactose of 50, and 200 mM, as well as 50, 200, and 500 mM of sucrose, and 500 mM of mannose, compared with that obtained when growing in Sabouraud dextrose broth (p < 0.01). The presence of other microorganisms, such as Lactobacillus acidophilus and L. casei, caused a decrease in the in vitro adherence of C. albicans to buccal epithelial cells (p < 0.05), whereas E. coli did not modify this adherence at all.     

Isolation and partial characterisation of a novel lectin from Aegle marmelos fruit and its effect on adherence and invasion of Shigellae to HT29 cells

Lectins are a class of ubiquitous proteins/glycoproteins that are abundantly found in nature. Lectins have unique carbohydrate binding property and hence have been exploited as drugs against various infectious diseases. We have isolated one such novel lectin from the fruit pulp of Aegle marmelos. The isolated lectin was partially characterised and its effect against Shigella dysenteriae infection was evaluated. The isolated lectin was found to be a dimeric protein with N-acetylgalactosamine, mannose and sialic acid binding specificity. The effect of Aegle marmelos fruit lectin on the adherence of Shigella dysenteriae to human colonic epithelial cells (HT29 cells) was evaluated by Enzyme Linked Immune Sorbent Assay and invasion was analysed. The protective nature of the Aegle marmelos fruit lectin was assessed by analyzing apoptosis through dual staining method. Aegle marmelos fruit lectin significantly inhibited hemagglutination activity of Shigella and its minimum inhibitory concentration is 0.625 μg/well. Further, at this concentration lectin inhibited Shigella dysenteriae adherence and invasion of HT29 cells and protects the HT29 cells from Shigella dysenteriae induced apoptosis. To conclude, isolated lectin dimeric protein with N-acetylgalactosamine, Mannose and sialic acid binding specificity and inhibits adherence and invasion of Shigellae to HT29 cells thus, protects the host.     

Induction of salivary antibodies to inhibit Candida albicans adherence to human epithelial cells by tonsillar immunization in rabbits

To examine the possibility of a vaccine for Candida albicans infection in the oral cavity, we induced salivary antibodies by immunization of killed-C. albicans ATCC 18804 on the palatine tonsils of rabbits. The enzyme-linked immunosorbent assay reaction of salivary antibodies was high against C. albicans serotype A. The saliva antibodies greatly inhibited C. albicans adherence to cloned epithelial cells from human gingiva. Tonsillar immunizations of C. albicans ATCC 18804 induce salivary antibodies that prevent C. albicans adherence to epithelial cells, and thus should prove useful in the prevention of oral candidiasis caused by C. albicans serotype A.     

Mnt1p and Mnt2p of Candida albicans are partially redundant alpha-1,2-mannosyltransferases that participate in O-linked mannosylation and are required for adhesion and virulence

The MNT1 gene of the human fungal pathogen Candida albicans is involved in O-glycosylation of cell wall and secreted proteins and is important for adherence of C. albicans to host surfaces and for virulence. Here we describe the molecular analysis of CaMNT2, a second member of the MNT1-like gene family in C. albicans. Mnt2p also functions in O-glycosylation. Mnt1p and Mnt2p encode partially redundant alpha-1,2-mannosyltransferases that catalyze the addition of the second and third mannose residues in an O-linked mannose pentamer. Deletion of both copies of MNT1 and MNT2 resulted in reduction in the level of in vitro mannosyltransferase activity and truncation of O-mannan. Both the mnt2Delta and mnt1Delta single mutants were significantly reduced in adherence to human buccal epithelial cells and Matrigel-coated surfaces, indicating a role for O-glycosylated cell wall proteins or O-mannan itself in adhesion to host surfaces. The double mnt1Deltamnt2Delta mutant formed aggregates of cells that appeared to be the result of abnormal cell separation. The double mutant was attenuated in virulence, underlining the importance of O-glycosylation in pathogenesis of C. albicans infections.     

A beta-linked mannan inhibits adherence of Pseudomonas aeruginosa to human lung epithelial cells

Adherence through carbohydrate-binding adhesins is an earlystep in colonization of the lung by gram-negative organisms,and because published data indicate that binding involves mannosegroups, we tested the ability of a ß-linked acetylmannan(acemannan) to inhibit adherence of Pseudomonus aeruginosa tocultures of human lung epithelial cells. Adherence of radiolabelledP.aeruginosa to A549 cells (a type II-like pneurnocyte line)increased linearly with the duration of the incubation. Acemannaninhibited adherence of bacteria, and the extent of inhibitionwas related to the concentration of the mannan. Inhibition requiredcontinued contact between acemannan and the target epithelialcells; cells washed free of acemannan no longer discouragedbacterial binding. Comparison of binding between seven strainsof P.aeruginosa indicated that fewer mucoid than non-mucoidbacteria adhered, but binding of either phenotype was inhibitedby acemannan. Mannose methyl -D-mannopyranoside, methyl ß-D-mannopyrannosideand dextran did not affect adherence of any of the non-mucoidstrains. Mannose inhibited adherence by one mucoid strain, butnot the other, indicating differences between strains of thesame phenotype. Since prior treatment of epithelial cells withconcanavalin A did not affect acemannan-induced inhibition ofbacterial adherence, we concluded that the inhibitory effectof acemannan probably does not involve mannose-containing receptors. bacterial-host interactions lung epithelium mucoid strains non-mucoid strains     

Effect of various components of the fungal cell wall on adhesion of Candida albicans to the mouth mucosa epithelium in vitro]

An influence of mannan++, its component methyl-D-mannopyranoside+ and N-acetylglucosamine on in vitro adhesion of Candida albicans strains to buccal mucosal epithelium was studied. These substances inhibited adhesion when added to adherence test in a concentration of 10 mg/ml and 25 mg/ml despite whether were added to the test incubation medium or when preincubated with fungi or epithelial cells. Preincubation of fungal cells and epithelial cells with mannan had no influence on attachment; preincubation of epithelial cells with methyl-D-mannopyranoside+ and N-acetylglucosamine decreased adherence significantly. On the other hand preincubation of fungal calls with methyl-D-mannopyranoside+ increased their adhesive properties, having no influence on adherence after preincubation of fungi with N-acetylglucosamine.     

Correlative relationship between adherence of Candida albicans to human vaginal epithelial cells in vitro and candidal vaginitis

This study investigated whether a correlation exists between predisposition to candidal vaginitis and adherence of Candida albicans to vaginal epithelial cells in vitro. Vaginal epithelial cells from 120 fecund women who were pregnant and/or diabetic had a greater propensity to bind C. albicans than did 71 oral contraceptive users and 75 non-pregnant, non-diabetic controls. The highest level of adherence occurred in pregnant diabetic women. Among 48 non-diabetic postmenopausal females, C. albicans adherence was lower than for fecund controls, but it was higher for cells from 33 postmenopausal diabetic women. The hormonal status of the fecund and postmenopausal women was assayed cytologically by the Karyopyknotic and Maturation Indices, which determine the ratios of superficial, intermediate and parabasal vaginal epithelial cells. Our findings point to increased C. albicans adherence in situations where there is an increase in the number of intermediate epithelial cells: pregnancy, the first or fourth weeks of the menstrual cycle, or diabetes. The adherence of 41 C. albicans isolates from patients with vaginitis was significantly higher than that of 36 isolates from asymptomatic carriers.