乳杆菌DM8909对金黄色葡萄球菌与阴道上皮细胞粘附影响的研究

本文对乳杆菌ＤＭ８９０９对阴道主要致病菌金黄色葡萄球菌与阴道上皮细胞的粘附影响作了补充实验。将等量ＤＭ８９０９液与金黄色葡萄球菌液同时与上皮细胞粘附进行了观察。结果表明,体外试验中,在ｐＨ７２情况下,乳杆菌与葡萄球菌同时加入时葡萄球菌粘附数量比葡萄球菌单独粘附少（Ｐ＜００１）,乳杆菌与金葡菌粘附数量相差不大（Ｐ＞００５）;乳杆菌与金葡菌先于ｐＨ４５下作用８１２ｈ,然后与上皮细胞同时孵育２小时,粘附的乳杆菌与金葡菌量比ｐＨ７２时均有减少,而金葡菌量比其单独粘附明显减少（Ｐ＜００１）,且明显少于乳杆菌（Ｐ＜００１）。说明乳杆菌能抑制葡萄球菌对阴道上皮细胞的粘附     

幽门螺杆菌粘附素的研究进展

定居是幽门螺杆菌（ＨＰ）致病关键步骤,而粘附素是一种重要定居因子,能与胃上皮细胞特异受体结合,目前研究国多的粘附素主要有两种;可溶性Ｎ－乙酰神经氨酰乳糖结合纤丝血凝素（ＮＬＢＨ）和胞外酶Ｓ样粘附素,本文论述粘附素的种类,性质及其结构特点,以及ｈｐａＡ基因的结构特点。     

2种乳酸菌对牙鲆体表、消化道粘液粘附及对4种致病菌的粘附抑制性

目的 研究2株乳酸菌（L1来自牙鲆肠道,L2为干酪乳杆菌）在牙鲆体表和消化道粘液的粘附及其对4种致病菌的粘附抑制情况。方法 异硫氰酸荧光素（FITC）标记法。结果 2种乳酸菌在牙鲆体表和消化道粘液中均有粘附性。在胃的粘附效果最好,粘附百分率分别是48．18％和63．0％,L2在牙鲆体表、盲囊和肠的粘附能力强于L1。L1对白色念珠菌（Candida albicans）在各部位均无粘附抑制作用,对荧光假单胞菌（P．Fluorescens）粘附抑制作用最强．使其在牙鲆消化道粘液的粘附百分率下降了19．01％,其余依次为非01型霍乱弧菌（V．cholerae non-Оl strains）、嗜水气单胞菌（Aeromonas hydrophila）,分别降低了5．22％、3．22％;L2对非Оl型霍乱弧菌粘附抑制效果最强,使其粘附百分率降低了22．31％。使荧光假单胞菌、嗜水气单胞菌和白色念珠菌分别下降了17．50％、12．69％、5．15％。结论 对4种常见致病菌的粘附抑制在消化道粘液中好于体表。     

肺炎链球菌粘附机制的研究现状

肺炎链球菌粘附宿主我肺炎链球菌侵袭、感染宿主细胞的先决条件。粘附过程是特异的,是细菌表面的粘附分子和宿主细胞膜受体相互作用的结果。英膜对肺炎链球菌的粘附无影响,而细胞壁（ＣＷ）在介导肺炎链附粘附宿主细胞过程中起重要作用;ＣＷ亚组人脂磷酸（ＬＴＡ）介导肺炎链球菌的粘附过程,并导致炎症反应;细菌表面的结构蛋白或分泌蛋白是细菌与宿主细胞连接的桥梁;肺炎链球菌能与宿主细胞外基质蛋白特异性结合,进而粘附宿主     

C a dh er in -1 基因与成骨分化

钙粘附蛋白-11（Cadherin-11）属于Ⅱ型钙粘附蛋白,是一种钙离子依赖性介导嗜同性细胞-细胞间粘附的跨膜糖蛋白。该种钙粘附蛋白在胚胎发育的肢节形成、骨组织形成、肿瘤浸润转移及细胞信号转导等方面具有多种生物学功能。本文就其基因结构、蛋白结构、连接特性和识别特异性、表达调控以及通过细胞-细胞粘附对间充质干细胞的成骨细胞方向分化和在骨形成中的作用进行综述。     

视黄酸促进NIH3T3细胞与纤连蛋白粘附的机制研究

视黄酸（Ｒｅｔｉｎｏｉｃ ａｃｉｄ,ＲＡ）是细胞的分化诱导剂。近年来发现ＲＡ能广泛作用于细胞,引起一系列生理功能改变,并能使多种肿瘤细胞向正常细胞分化。ＲＡ对细胞基本生物学行为－细胞粘附的影响了解甚少。我们发现３２μｍｏｌ／Ｌ ＲＡ能使ＮＩＨ３Ｔ３细胞与纤维蛋白（ＦＺｉｂｒｏｎｅｃｔｉｎ,Ｆｎ）的粘附能力增加２０％。但并不促进细胞与多聚赖氨到的粘附。采用抗整合蛋白α５亚基单抗和抗整合蛋白β１亚基单     

聚乙二醇对羟基丁酸和羟基己酸共聚物的共混改性研究

本研究以聚羟基脂肪酸酯家族中的新成员羟基丁酸和羟基己酸共聚物（PHBHHx）为基础,采用与聚乙二醇（PEG）共混的方法对其进行改性,研究结果证实：PHBHHx与PEG 共混物中比例为3:1及2:1时,两者完全物理相容。而PEG在共混物中比例升高时则导致相分离,成为部分相容体系。PEG掺入显著提高材料亲水性及表面自由能,使血管平滑肌细胞（RaSMCs）及血管内皮细胞（HUVECs）的细胞粘附及增殖大幅度提高,并且均具有一定的PEG含量依赖性。其中对RaSMCs的作用最为明显,RaSMCs能在PEG/PHBHHx比例为1:1的共混膜（E1X1）上持续增殖至融合,而HUVECs则呈粘附较差的类球形形貌,证实E1X1可以潜在应用于复合血管组织工程支架中的近内膜基材。     

双歧杆菌及表面分子对胃粘膜糖蛋白的粘附作用

目的：研究双歧杆菌及表面分子脂磷壁酸（Ｌｉｐｏｔｅｉｃｈｏｉｃ ａｃｉｄ,ＬＴＡ）、完整肽聚粮（Ｗｈｏｌｅ ｐｅｐ－ｔｉ－ｄｏｇｌｙｃａｎ ＷＰＧ）、多糖（Ｐｏｌｙｓａｃｃｈａｒｉｄｅ,ＰＳ）对猪胃粘膜糖蛋白的粘附作用。方法 采用ＥＬＩＳＡ阻断法测定了全菌不同菌液浓度的粘附作用。结果 表明ＬＴＡ、ＷＰＧ的粘附作用明显,ＰＳ粘附作用很弱。粘附随着菌液浓度的增高而增强。结论 在双歧杆菌的定植粘附机理中     

中国茶对变形链球菌的抑菌作用

对３６只ｓｐｒａｑｕｅ－Ｄａｗｌｅｙ鼠分４组给予诱龋饲料（Ｄｉｅｔ２０００,ｋｅｙｓ）,并连续５天在口腔内接种变链菌６７１５菌株,分别给予我国主要产茶区的三种茶浸液：龙井绿茶（Ｂ组）,四川涪陵红茶（Ｃ组）,乌龙茶（Ｄ组）,先用０．５ｇ茶和５０ｍｌ双蒸馏水加热煮沸过滤后浸泡１０分钟以及对照组（Ａ组）用双蒸馏水为饮料喂养实验鼠。实验６０天后,杀鼠观察计算鼠磨牙面的菌落形成单位（ＣＦＵ）和菌斑指数（ｐｌａｑｕｅｓｃｏｒｅ）均显著下降。实验结果,实验组和对照组菌斑指数下降值顺序如下：Ｃ组＞Ｄ组＞Ｂ组＞Ａ组,并与实验组含氟量有相关性。很多研究表明变链菌是较为肯定的致龋菌、茶中氟化物对变链菌生长、粘附都有抑制作用。本研究选用茶来源广泛、价廉、无毒安全等优点,为开拓新的防龋方法进行探索。     

阻断白色念珠菌粘附口腔膜上皮细胞的实验研究

白色念珠菌的粘附与其表面甘露糖结构有关,为探讨阻断粘附的方法,我们采用体外法测定其对口腔上皮细胞的粘附数量,显示：白色念珠菌粘附感染上皮细胞后,甘露糖可以在一定程度上减少粘附,绿慕安及刀豆素A可以有效地减少粘附。提示甘露糖及绿慕安可能有助于治疗白色念珠菌感染。     

Factors involved in adherence of lactobacilli to human Caco-2 cells.

A quantitative assay performed with bacterial cells labelled with [3H]thymidine was used to investigate factors involved in the adherence of human isolates Lactobacillus acidophilus BG2FO4 and NCFM/N2 and Lactobacillus gasseri ADH to human Caco-2 intestinal cells. For all three strains, adherence was concentration dependent, greater at acidic pH values, and significantly greater than adherence of a control dairy isolate, Lactobacillus delbrueckii subsp. bulgaricus 1489. Adherence of L. acidophilus BG2FO4 and NCFM/N2 was decreased by protease treatment of the bacterial cells, whereas adherence of L. gasseri ADH either was not affected or was enhanced by protease treatment. Putative surface layer proteins were identified on L. acidophilus BG2FO4 and NCFM/N2 cells but were not involved in adherence. Periodate oxidation of bacterial cell surface carbohydrates significantly reduced adherence of L. gasseri ADH, moderately reduced adherence of L. acidophilus BG2FO4, and had no effect on adherence of L. acidophilus NCFM/N2. These results indicate that Lactobacillus species adhere to human intestinal cells via mechanisms which involve different combinations of carbohydrate and protein factors on the bacterial cell surface. The involvement of a secreted bridging protein, which has been proposed as the primary mediator of adherence of L. acidophilus BG2FO4 in spent culture supernatant (M.-H. Coconnier, T. R. Klaenhammer, S. Kernéis, M.-F. Bernet, and A. L. Servin, Appl. Environ. Microbiol. 58:2034-2039, 1992), was not confirmed in this study. Rather, a pH effect on Caco-2 cells contributed significantly to the adherence of this strain in spent culture supernatant.(ABSTRACT TRUNCATED AT 250 WORDS)     

Adherence of Clostridium thermocellum to cellulose

The adherence of Clostridium thermocellum, a cellulolytic, thermophilic anaerobe, to its insoluble substrate (cellulose) was studied. The adherence phenomenon was determined to be selective for cellulose. The observed adherence was not significantly affected by various parameters, including salts, pH, temperature, detergents, or soluble sugars. A spontaneous adherence-defective mutant strain (AD2) was isolated from the wild-type strain YS. Antibodies were prepared against the bacterial cell surface and rendered specific to the cellulose-binding factor (CBF) by adsorption to mutant AD2 cells. By using these CBF-specific antibodies, crossed immunoelectrophoresis of cell extracts revealed a single discrete precipitation peak in the parent strain which was absent in the mutant. This difference was accompanied by an alteration in the polypeptide profile whereby sonicates of strain YS contained a 210,000-molecular-weight band which was missing in strain AD2. The CBF antigen could be removed from cell extracts by adsorption to cellulose. A combined gel-overlay--immunoelectrophoretic technique demonstrated that the cellulose-binding properties of the CBF were accompanied by carboxymethylcellulase activity. During the exponential phase of growth, a large part of the CBF antigen and related carboxymethylcellulase activity was associated with the cells of wild-type strain YS. However, the amounts decreased in stationary-phase cells. Cellobiose-grown mutant AD2 cells lacked the cell-associated CBF, but the latter was detected in the extracellular fluid. Increased levels of CBF were observed when cells were grown on cellulose. In addition, mutant AD2 regained cell-associated CBF together with the property of cellulose adherence. The presence of the CBF antigen and related adherence characteristics appeared to be a phenomenon common to other naturally occurring strains of this species.     

Adherence ofStaphylococcus epidermidis to pharyngeal epithelial cells mediated by lipoteichoic acid

Prior treatment of pharyngeal epithelial cells (PEC) with lipoteichoic acid (LTA) derived fromStaphylococcus epidermidis produced a marked inhibition of adherence of the homologous strain and two heterologous strains. The inhibition was dose dependent and saturable with 100 µg/ml of LTA. However, pretreatment of PEC with deacylated LTA did not block the adherence of the three strains tested. A similar but less marked blocking effect on the adherence ofS. epidermidis to PEC was also observed with LTAs derived fromS. aureus andStreptococcus pyogenes. On treatment of bacteria with substances capable of binding to LTA, such as polyclonal mouse anti-LTA antibodies or with human albumin, a marked inhibition of bacterial adherence was observed. Immunofluorescence studies showed that anti-LTA antiserum bound readily to the surface of bacterial cells. These findings provide clear evidence that the lipid component of LTA located on the bacterial surface is centrally involved in the adherence ofS. epidermidis to human mucosal cells.     

Adherence of Fusobacterium necrophorum to bovine hepatic cells

Abstract The adherence of Fusobacterium necrophorum to the surface of bovine hepatic cells was investigated. Hemagglutinating strain VPI2891 adhered well to the cell membranes, whereas non-hemagglutinating strain S-45 adhered less well. The adherence of the former strain was strongly inhibited by the homologous anti-hemagglutinin serum. Immunofluorescence study revealed that the purified hemagglutinin bound to the membranes of the hepatic cells. These findings suggest that the adherence of F. necrophorum to the bovine hepatic cells is mediated by the bacterial hemagglutinin and has pathogenic importance in bovine necrobacillosis.     

In vitro adherence of Candida albicans strains to murine gastrointestinal mucosal cells and explants and the role of environmental pH

Two in vitro adherence assays involving isolated mucosal cells or mucosal explants were used to study the adherence of five Candida albicans strains to murine gastrointestinal mucosal surfaces. Adherence was found to be dependent on the strain used, and on the cellular arrangement, as well as the site of origin of the mucosal surface. Adherence of strains NCPF 3436 and 3310 to stomach and jejunal surfaces was affected by the pH of the medium. Binding between the C. albicans strains and stomach mucosal cells fluctuated as the pH was raised from pH 1.2 to pH 3.4. However, adherence increased with a rise in pH when the strains were incubated with stomach mucosal explants. Optimal adherence by both strains to jejunal mucosal surfaces occurred at neutral pH.     

NafA negatively controls Neisseria meningitidis piliation

Bacterial auto-aggregation is a critical step during adhesion of N. meningitidis to host cells. The precise mechanisms and functions of bacterial auto-aggregation still remain to be fully elucidated. In this work, we characterize the role of a meningococcal hypothetical protein, NMB0995/NMC0982, and show that this protein, here denoted NafA, acts as an anti-aggregation factor. NafA was confirmed to be surface exposed and was found to be induced at a late stage of bacterial adherence to epithelial cells. A NafA deficient mutant was hyperpiliated and formed bundles of pili. Further, the mutant displayed increased adherence to epithelial cells when compared to the wild-type strain. In the absence of host cells, the NafA deficient mutant was more aggregative than the wild-type strain. The in vivo role of NafA in sepsis was studied in a murine model of meningococcal disease. Challenge with the NafA deficient mutant resulted in lower bacteremia levels and mortality when compared to the wild-type strain. The present study reveals that meningococcal NafA is an anti-aggregation factor with strong impact on the disease outcome. These data also suggest that appropriate bacterial auto-aggregation is controlled by both aggregation and anti-aggregation factors during Neisseria infection in vivo.     

Adherence ofStaphylococcus epidermidis to human pharyngeal epithelial cells: Evidence for lipase-sensitive adhesin and glycoprotein receptor

The adherence of eight strains ofStaphylococcus epidermidis to human pharyngeal epithelial cells (PEC) was investigated. All bacterial strains were nonencapsulated and non-slime producers. Binding was mannose resistant and was not related to surface hydrophobicity and surface charge of bacteria. Adherence to epithelial cells was reduced four- to tenfold (P<0.01) on pretreatment of bacteria with lipase while neuraminidase, phospholipase C, trypsin, and sodium periodate did not alter their binding. The surface carbohydrate profile of bacteria was studied by monitoring adherence to Lectin-Sepharoses. The bacteria did not conform to any pattern, and there was no relation to strain variation. The pretreatment of PEC with trypsin and sodium metaperiodate produced a marked reduction in bacterial binding (three- to 25-fold, P<0.01), but neuraminidase, phospholipase C, and lipase did not have any such effect. These findings provide evidence that the receptors on the surface of PEC are glycoprotein in nature, while the bacterial adhesin is a lipase-sensitive material.     

Cell surface properties of two differently virulent strains of Acinetobacter baumannii isolated from a patient

The aim of this study was to unravel, by focusing on cell surface properties, the underlying virulence factors contributing to the difference in the pathogenicity observed in two Acinetobacter baumannii strains isolated from the same patient. The two strains were phenotypically different: (i) a mucoid strain (AB-M), highly virulent in a mouse model of pneumonia, and (ii) a nonmucoid strain (AB-NM), moderately virulent in the same model. The study of the cell surface properties included the microbial adhesion to solvents method, the measurement of the electrophoretic mobility of bacteria, the analysis of biofilm formation by calcofluor white staining, the adherence to silicone catheters, and scanning electron microscopy. The AB-NM strain was more hydrophobic, more adherent to silicone catheters, and produced more biofilm than the AB-M strain. Scanning electron microscopy showed bacterial cells with a rough surface and the formation of large cell clusters for AB-NM whereas the AB-M strain had a smooth surface and formed only a few cell clusters. Contrary to the results of most previous studies, cell surface properties were not correlated to the virulence described in our experimental model, indicating that mechanisms other than adherence may be involved in the expression of A.?baumannii virulence.     

Some factors affecting the adherence of probiotic Propionibacterium acidipropionici CRL 1198 to intestinal epithelial cells

Adhesion to the intestinal mucosa is generally considered an important property of probiotic microorganisms and has been related to many of their health benefits. This study investigated some factors that could affect or be involved in the adherence of Propionibacterium acidipropionici CRL 1198, a dairy strain with suggested probiotic effects and high adherence in vitro and in vivo to intestinal epithelial cells. In vitro adhesion of propionibacteria was decreased by gastric digestion but not affected by bile and pancreatic enzymes. Adherence was also decreased by pretreatment of bacterial cells with protease, sodium metaperiodate, and trichloroacetic acid, revealing that different features of the cell surface, like protein factors, carbohydrates, and teichoic acids, are involved in the process. Adherence to intestinal epithelial cells was enhanced by calcium and was dependent on other divalent cations. Adhesion to intestinal mucus was also demonstrated. The results should explain the metabolic effects in the host previously obtained with this strain and support the potential of Propionibacterium for development of new probiotics.