Adherence of Candida albicans and Candida dubliniensis to buccal and vaginal cells

Twenty-seven Candida albicans strains and 26 Candida dubliniensis strains, isolated from HIV patients, were tested for their adherence to buccal and vaginal epithelial cells. Both species showed important levels of adhesion to buccal and vaginal epithelial cells, although C. albicans showed the highest levels of adhesion. These results suggest that both Candida species are well adapted, in terms of adhesion capability, to the oral and vaginal environment.     

Adherence of Candida albicans to buccal and vaginal epithelial cells: ultrastructural observations

The adherence of Candida albicans to human buccal and vaginal epithelial cells was studied by transmission electron microscopy. Adherence to epithelial cells was confirmed by both a radiometric assay as well as direct microscopic examination of stained cell preparations. Ultramicroscopic preparations revealed that yeast cells were closely appressed to epithelial cell surfaces and were often partially enclosed within phagocyticlike invaginations of the epithelial cells. A murine model of vaginitis caused by C. albicans was also used to study adherence to epithelial cells and to follow the course of colonization. Ultramicroscopic preparations of murine vaginal tissue revealed that within 2 h postinfection, yeast cells could be seen adhering to epithelial cells. At 6 h postinfection, hyphae and yeast cells were not only found on the epithelial cell surface but also within the submucosal tissue. When observed on the epithelial cell surface, Candida cells were either attached to host cells, or when infected tissue was stained with ruthenium red, Candida cells were observed on the epithelial surface embedded within an electron-dense matrix. Fungal elements were abundant in the submucosa at 24 h postinfection and were still observed on the epithelial cell surface; all of this was accompanied by an inflammatory response.     

Reduced adherence of micro-organisms to human mucosal epithelial cells following treatment with Taurolin, a novel antimicrobial agent

Taurolin, a non-antibiotic antimicrobial agent, significantly reduced the adherence of buccal and vaginal strains of Candida albicans blastospores and urine isolates of Escherichia coli and Staphylococcus saprophyticus to epithelial cells. Light microscopy and radio-isotopic counting methods were used to quantify the adherence of the micro-organisms to either uroepithelial or buccal epithelial cells. A maximum reduction in adherence of approximately 65% was obtained. The anti-adherence capacity was time-dependent, requiring a contact time of 30 min to achieve maximum effect. Taurolin at sub-minimum inhibitory concentrations (MIC) significantly reduced the adherence of Candida and E. coli. A concentration slightly higher than the MIC was required for Staph. saprophyticus. Treatment of either epithelial cells or micro-organisms with Taurolin resulted in reduced adherence of microorganisms.     

Reduced adherence of micro-organisms to human mucosal epithelial cells following treatment with Taurolin, a novel antimicrobial agent

Taurolin, a non-antibiotic antimicrobial agent, significantly reduced the adherence of buccal and vaginal strains of Candida albicans blastospores and urine isolates of Escherichia coli and Staphylococcus saprophyticus to epithelial cells. Light microscopy and radio-isotopic counting methods were used to quantify the adherence of the micro-organisms to either uroepithelial or buccal epithelial cells. A maximum reduction in adherence of approximately 65% was obtained. The anti-adherence capacity was time-dependent, requiring a contact time of 30 min to achieve maximum effect. Taurolin at sub-minimum inhibitory concentrations (MIC) significantly reduced the adherence of Candida and E. coli. A concentration slightly higher than the MIC was required for Staph. saprophyticus. Treatment of either epithelial cells or micro-organisms with Taurolin resulted in reduced adherence of microorganisms.     

Decrease in adherence of bacteria and yeasts to human mucosal epithelial cells by noxythiolin in vitro

Adherence of buccal and vaginal isolates of Candida albicans to buccal epithelial cells and the adherence of urine isolates of Escherichia coli and Staphylococcus saprophyticus to uroepithelial cells was quantified by light microscopy. The antimicrobial agent noxythiolin reduced the adherence of these micro-organisms in both exponential and stationary growth phases. Adherence of both the blastospore and pseudohyphal forms of C. albicans was reduced. Treatment of epithelial cells and/or micro-organisms with noxythiolin resulted in decreased adherence. No anti-adherence effect was observed with formaldehyde and N-methylthiourea, the degradative products of noxythiolin.     

Effect of enzymes on the adhesion of fungi of the genus Candida to the buccal mucosa in vitro

Influence of selected enzymes as pepsin, pronase, lysozyme, and glusulase on adhesion of 15 strains of Candida sp. to buccal epithelial cells of oral cavity of man was examined in vitro. The enzymes were used in such concentration which did not influence the viability of fungal cells. Only pepsin preincubation had no influence on adhesion test, the remaining enzymes inhibited significantly attachment of Candida strains to epithelial cells in an adherence assay in vitro.     

Antifungal activity of the amyrin derivatives and in vitro inhibition of Candida albicans adhesion to human epithelial cells

AIMS: The antifungal activity of amyrin pentacyclic triterpene and 15 synthetic derivatives was evaluated against Candida species. Additionally, inhibition of adhesion of Candida albicans to human epithelial cells in vitro was determined. METHODS AND RESULTS: Esterification of alpha- and beta-amyrin with a variety of acyl chlorides produced a series of analogue derivatives. These substances were synthesized to evaluate the antifungal properties against Candida species. Among the 15 derivatives, alpha- and beta-amyrin formiate (2) and alpha- and beta-amyrin acetate (3) were the most active, inhibiting all the Candida species tested in concentrations that ranged from 30 to 250 microg ml(-1). alpha- and beta-amyrin formiate inhibited the adhesion ability of C. albicans to buccal epithelial cells (BEC) in 65.3%. CONCLUSIONS: alpha- and beta-amyrin formiate and alpha- and beta-amyrin acetate derivatives exhibited potential antifungal activity against Candida spp. and amyrin formiate showed inhibition of the adhesion ability of C. albicans to buccal epithelial cells. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrated that two derivatives of amyrin pentacyclic triterpene exhibited significant antifungal activity against Candida species. Additionally, alpha- and beta-amyrin formiate was as effective as fluconazole in inhibiting the adhesion of C. albicans to buccal epithelial cells.     

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.     

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。     

Influence of mucosal cell origin on the in vitro adherence of Candida albicans: Are mucosal cells from different sources equivalent?

The influence of collecting mucosal cells from various anatomical sites, and varying the date of collection and cell donor on adhesion of Candida albicans to human epithelial cells was examined by using an in vitro adherence assay. Examination of buccal mucosal cells from twenty-four donors showed statistically significant differences in the number of attached yeasts between individuals. Sex did not exert a significant influence on adhesion. Examination of buccal mucosal cells from ten donors collected on five different dates revealed that yeast attachment to mucosal epithelial cells varied significantly within subjects across time. Epithelial cells from some donors manifested greater date-to-date variations in yeast adhesion than others. Adherence of Candida to mucosal cells from three anatomical sites (mouth, vagina and urinary tract) collected from ten different donors was also tested. Yeast adherence to buccal cells was highest, lowest using urinary tract cells, while vaginal epithelium was intermediate. Adherence to mucosal cells from three sites was significantly different both within and between individuals although some subjects manifested larger variations than others. These data suggest that the in vitro adherence of Candida albicans is influenced by mucosal cell donor, date of collection and body site of origin. Mucosal cells from different sources do not appear to be equivalent in receptiveness to C. albicans and this might explain some of the discrepancies observed when adhesion studies performed by different investigators are compared. The existing need for a more uniform methodology with which to pursue studies on fungal attachment to mucosal surfaces is emphasized.     

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。     

Initial attachment ofCandida albicans cells to buccal epithelial cells

The rapid-freezing technique was applied in association with scanning and transmission electron microscopy to observe the initial attachment (or contact) ofCandida albicans cells to exfoliated human buccal epithelial cells. Low temperature scanning electron microscopy provided detailed three-dimensional morphological features of the yeast-epithelial cell association; adhesion ofC. albicans cells to host cells was primarily owing to an interaction between fibrillar layer of the yeast cell wall and the membrane interdigitations of the epithelial cells. Such a particular interconnection between the two cells was confirmed by the freeze-substitution fixation for transmission electron microscopy. These results clearly demonstrate the outermost fibrillar cell wall layer ofC. albicans responsible for adhesion to host cells.     

Hydrophobic and adhesive capacity of Candida strains isolated from patients with fungal infection

The aim of this study was to evaluate hydrophobicity of fungal strains of Candida sp. isolated from clinical materials of patients with fungal infections. Two hundred and eighty one strains of C. albicans and 29 strains belonging to the other species of Candida were tested in salt aggregation test (SAT). Strong hydrophobicity (autoaggregation in the test) was found in 29.4% of tested strains. The majority of them was isolated from vagina. In 20 randomly selected strains hydrophobicity was measured not only by salt aggregation test but also by hydrophobic interaction chromatography (MIC). The ability to attach to buccal epithelial cells in vitro was compared between 50 strongly hydrophobic strains and 30 with low hydrophobicity. The former strains attached significantly stronger (p less than 0.001).     

白念珠菌ALS3、SSA1基因表达在念珠菌性阴道炎免疫机制中的作用

目的探讨白念珠菌ALS3、SSA1基因缺失对阴道上皮细胞激发免疫反应的作用。方法培养白念珠菌野生株及ALS3、SSA1基因敲除株(SC5314、Δals3、Δssa1),对其进行形态测定。按不同MOI感染人阴道上皮细胞系VK2/E6E7细胞,通过台盼蓝染色观察和乳酸脱氢酶(LDH)活性检测,评价不同MOI白念珠菌对上皮细胞的损伤作用;使用酶联免疫吸附试验(ELISA)评估感染过程中炎性细胞因子及趋化因子在共培养上清中的差异。结果 ALS3基因的缺失对白念珠菌芽管长度影响差异无统计学意义,而SSA1基因的缺失与其他两个菌株相比芽管长度减少约30%～40%(P<0.001)。台盼蓝染色观察及LDH测定发现,3株菌在感染上皮细胞时,其细胞损伤能力均与菌载量成正比;与野生型相比,Δssa1突变体在相同比率感染上皮细胞时,细胞损伤能力明显降低,且差异有统计学意义(P<0.05),Δals3突变株影响较小,甚至略微升高。检测炎性细胞因子及趋化因子发现,突变株在诱导上皮细胞产生促炎因子及趋化因子(GM-CSF、G-CSF、IL-1α、IL-8)的能力上明显减弱,差异均有统计学意义(P<0.05)。结论 ALS3和SSA1基因表达在阴道上皮细胞抗白念珠菌感染的局部免疫应答过程中可能起到重要作用,且SSA1基因表达意义更大。     

Relationship between the morphology of Candida cells and vaginal discharge

The aim of this study was to detect whether there is a correlation between the dimorphic pattern of Candida cells and various types of vaginal discharge. For this purpose, 2861 Papanicolaoustained cervicovaginal smears were examined cytologically and 265 of 2861 (9.26%) were diagnosed as having Candida cells. The 88 of 295 (29.83%) were identified as having blastospores only, 135 of 295 (45.76%) as having "hyphae only", and 47 of 295 (15.93%) as having both blastospores and hyphae of candida cells. There was a significant correlation between the type of candida cells and vaginal discharge (p < 0.05). The white-cheesy type vaginal discharge was the most prominent symptom for the observation the "hyphae only" following "blastospores only" and both blastospores and hyphae of Candida cells. It was suggested that hyphael form of Candida cells is the most pathogenic pattern and white-cheesy vaginal discharge is a marker for the presence of hyphael form in the vaginal mucosa.     

The ultrastructure of Candida albicans infections

Scrapings of Candida albicans plaques from the tongue and buccal mucosa of patients with oral candidiasis were examined by electron microscopy. In addition, urine sediment from patients with infection of their catheterized urinary tracts was similarly examined. Three types of C. albicans-oral epithelial cell interactions were noted: a loose adherence apparently mediated by a ruthenium red positive matrix, a "tight" adherence where no space could be seen between the host and yeast cell. and invasion of host cells by yeast hyphal elements. Adhesion of Candida blastospores to hyphal elements and adhesion of bacteria to Candida cells was also frequently observed. Urine sediments from patients with mixed bacteria-yeast infections demonstrated adhesion of the bacteria to the yeast cells. This phenomenon was also demonstrated in in vitro experiments and fibrous ruthenium red material invariably occupied the zone of adhesion. Phagocytosis of yeast by polymorphonuclear leukocytes was found in urinary, but not in oral. candidiasis. Our in vivo and in vitro observations indicate that a ruthenium red positive matrix covers the surfaces involved in the yeast to yeast, yeast to host, and yeast to bacteria adhesion.     

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.     

Reduced adherence and inhibition of hyphal development of Candida albicans by the antimicrobial agent polynoxylin

Polynoxylin (Anaflex R) was investigated for antimicrobial activities ancillary to its known cidal and static effects. Significant reductions in adherence of Candida albicans blastospores (oral strain) to human buccal epithelial cells were observed following polynoxylin treatment. The anti-adherence activity was concentration and time-dependent. Treatment of the epithelial cells did not result in significant reductions in adherence. Polynoxylin was also shown to inhibit the germination and hyphal development of C. albicans.     

Differential adhesion of pathogenic Candida species to epithelial and inert surfaces

Abstract Growth in medium containing 500 mM galactose is known to promote the adhesion of Candida albicans to buccal epithelial cells or to acrylic in vitro. Of 5 other Candida species tested, only C. tropicalis (one strain) showed substantially increased adhesion to buccal cells (but not to acrylic) after growth under these conditions. A second strain of C. tropicalis as well as C. stellatoidea, C. parapsilosis, C. pseudotropicalis, C. guilliermondii and Saccharomyces cerevisiae showed little or no increased adhesion to either surface. However, after growth in medium containing 50 mM glucose, C. tropicalis and C. parapsilosis were significantly more adherent to acrylic than glucose-grown yeasts of the other species, including C. albicans . These results are discussed in relation to the colonization and infection potential of the pathogenic Candida species.