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Abstract Protoplasts from auxotrophic mutants of Candida albicans and Candida tropicalis were produced by snail enzyme treatment and their fusion was induced with polyethylene glycol (PEG). During selective regeneration, nutritionally complemented interspecific hybrids were obtained. Their cells contained one nucleus, and the DNA content per cell was higher than in the parents. The isoenzymic and sugar assimilation patterns of the mutants, and those of the hybrids and the products after their haploidisation, were also analysed. The results indicated that the hybrids were partial alloploids containing the total chromosomal set of either of the parental species and one or a few chromosomes of the other. 相似文献
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Abstract A Candida albicans aspartic proteinase (CAP), one of the secretory proteinases of Candida albicans , is thought to be a possible virulence factor in Candida albicans infection. Whereas endothelin-1 is found as an endothelium-derived strong vasoconstrictive peptide, it is known to have a role in the maintenance of vascular homeostasis and tissue survival. Endothelin-1 is generated from a precursor form of endothelin-1, the so-called big endothelin-1. It has recently been reported that cathepsin D, E and pepsin, which are aspartic proteinases, convert big endothelin-1 to endothelin-1. In this study, the relationship between CAP and big endothelin-1 was studied. High performance liquid chromatography analysis revealed that big endothelin-1 was cleaved into several amino acid sites by CAP, but endothelin-1 was not converted from big endothelin-1. CAP cleaved big endothelin-1 at different sites when compared with that of other known aspartic proteinases, and it suppressed endothelin-1 production through the degradation of big endothelin-1. CAP may break homeostatic mechanism of endothelin-1 in Candida albicans infectious lesion. 相似文献
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目的 用一种新制备的单克隆抗体MAb03.2Cl-C2鉴别生物学形态相近的白念珠菌和都柏林念珠菌。方法 用小鼠体内诱导法制备抗白念珠菌芽管胞壁外膜单克隆抗体MAb03.2Cl-C2。用不完全RPMI1640培养液、L—DMEM、H—DMEM、完全1640液、小牛血清诱导白念珠菌和都柏林念珠菌芽管及菌丝形成,间接免疫荧光(IIF)方法检测都柏林念珠菌芽管或菌丝表面有无可与该单抗相结合的成分。收集临床口腔念珠菌病标本涂片,直接做IIF试验。结果 用不完全RP-MI1640培养液37℃,6h可同时最高效率地诱导白念珠菌和都柏林念珠菌芽管或菌丝形成。单抗MAb03.2Cl-C2仅与白念珠菌芽管或菌丝特异性地结合,与都柏林念珠菌的孢子和菌丝不能结合。结论 单抗MAh03.2Cl-C2可用于白念珠菌和都柏林念珠菌实验室的速鉴别。 相似文献
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M. Armelles 《FEMS microbiology letters》1989,60(2):153-157
Abstract In the present study, we assessed the influence of three culture media on the susceptibility 'in vitro' of twenty four clinical strains belonging to Candida albicans against three imidazole-derivatives and also, we investigated the situation of azole sensitivity in three of these strains. 相似文献
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都柏林念珠菌的鉴定及与白念珠菌3种表型鉴别方法的研究 总被引:1,自引:0,他引:1
目的 从临床分离的念珠菌中进一步鉴定都柏林念珠菌,并评价3种表型鉴别白念珠菌和都柏林念珠菌的方法.方法 对17株临床分离并初步鉴定的白念珠菌和1株ATCC白念珠菌标准株,采用PHR1同源序列PCR法检测,鉴定出其中的都柏林念珠菌;分别采用45℃生长试验、YEPD(1%酵母浸膏,2%蛋白胨,2%葡萄糖)液基39℃芽管生成试验、Staib琼脂(鸟食琼脂)厚壁孢子形成试验对两种菌的表型特点进行比较.结果 17株临床分离的白念珠菌中有3株鉴定为都柏林念珠菌;45℃时,两种菌在改良沙堡弱琼脂上均无明显生长,YEPD液基中仅有1株白念珠菌生长良好;YEPD液基39℃培养2种菌均无芽管生成;Staib琼脂培养72h,3株都柏林念珠菌中有2株可形成厚壁孢子,而白念珠菌则无,与PHR1同源序列检测结果基本一致.结论 PHR1同源序列检测是鉴别都柏林念珠菌与白念珠菌的可靠方法,Staib琼脂厚壁孢子形成试验有助于鉴别两菌,45℃生长试验和YEPD液基39℃芽管生成试验则不能有效鉴别两菌. 相似文献
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Francesco Citiulo Gary P. Moran David C. Coleman & Derek J. Sullivan 《FEMS yeast research》2009,9(7):1051-1060
Candida albicans and Candida dubliniensis are the only Candida sp. that have been observed to produce chlamydospores. The function of these large, thick-walled cells is currently unknown. In this report, we describe the production and purification of chlamydospores from these species in defined liquid media. Staining with the fluorescent dye FUN-1 indicated that chlamydospores are metabolically active cells, but that metabolic activity is undetectable in chlamydospores that are >30 days old. However, 5–15-day-old chlamydospores could be induced to produce daughter chlamydospores, blastospores, pseudohyphae and true hyphae depending on the incubation conditions used. Chlamydospores that were preinduced to germinate were also observed to escape from murine macrophages following phagocytosis, suggesting that these structures may be viable in vivo . Mycelium-attached and purified chlamydospores rapidly lost their viability in water and when subjected to dry stress, suggesting that they are unlikely to act as long-term storage structures. Instead, our data suggest that chlamydospores represent an alternative specialized form of growth by C. albicans and C. dubliniensis . 相似文献
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We used multi-locus sequence typing (MLST) to investigate 35 yeast isolates representing the two genome-sequenced strains plus the type strain of Candida albicans, four isolates originally identified as Candida stellatoidea type I and 28 representing type strains of other species now regarded as synonymous with C. albicans. DNA from all 32 C. albicans synonyms readily formed PCR products with the C. albicans MLST primer sets. Their sequences placed all of them within the existing C. albicans clade structure, represented by 1516 isolates. One isolate, originally received as Mycotorula sinensis, was resistant to flucytosine, but no other unusual susceptibilities were found to polyene, azole or echinocandin antifungal agents. The four isolates of C. stellatoidea type I coclustered with two other sucrose-negative isolates, originally identified as examples of Candida africana, in a group of strains highly distinct from the majority of C. albicans. Our results not only confirm the synonymity of all the isolates with C. albicans but also confirm an obvious genotypic difference in the case of C. stellatoidea type I. 相似文献
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Abstract Mice immunized with ribosomes from Candida albicans are protected against experimental systemic candidiasis. In this study we investigated the candidacidal activity of spleen cells from immunized animals as measured by 51 Cr release from pre-labelled yeast cells. It was found that the anti-candidal cytotoxic activity of splenocytes from immunized mice was significantly higher than that of spleen cells from non-immunized controls with various effector to target (E:T) ratios, but optimal results were obtained with an E:T ratio of 10:1. The cytotoxic activity of splenocytes as measured by the 51 Cr release assay correlated well with the capacity of the cells to inhibit candidal growth as determined by quantitative plating. This candidacidal activity was not antibody dependent but increased killing was obtained by adding fresh (but not heat inactivated) mouse serum. The enhanced candidicidal activity was inhibited by removal of plastic- or nylon-adherent cells from the cell suspension but not by treatment with anti-Thy 1.2 serum and complement. The data indicate that a candidacidal cell population is induced in the spleens of animals immunized with C. albicans ribosomes. 相似文献
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紫外线作为重要的环境因子之一,能显著影响包括白念珠菌在内的多种生物的生长及生理过程.研究发现白念珠菌受紫外线照射后菌丝形成被抑制,孢子形成增多且没有向光性;脉冲紫外线辐射可通过多靶点程序使白念珠菌失活;rad 51缺陷株比rad 52缺陷株更易受紫外线损害,同时紫外线可导致白念珠菌杂合性丢失.研究还发现UVC治疗可明显减少烧伤后真菌微生物感染,核黄素/UVA治疗可明显抑制白念珠菌生长.因此紫外线对白念珠菌有一定的抑制作用. 相似文献
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According to different metabolic situations in various stages of Candida albicans pathogenesis the regulation of carbohydrate metabolism was investigated. We report the genetic characterization of all major C. albicans gluconeogenic and glyoxylate cycle genes (fructose-1,6-bisphosphatase, PEP carboxykinase, malate synthase and isocitrate lyase) which were isolated after functional complementation of the corresponding Saccharomyces cerevisiae deletion mutants. Remarkably, the regulation of the heterologously expressed C. albicans gluconeogenic and glyoxylate cycle genes was similar to that of the homologous S. cerevisiae genes. A C. albicans DeltaCafbp1 deletion strain failed to utilize non-fermentable carbon sources but hyphal growth was not affected. Our results show that regulation of gluconeogenesis in C. albicans is similar to that of S. cerevisiae and that the current knowledge on how gluconeogenesis is regulated will facilitate the physiological understanding of C. albicans. 相似文献
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Abstract A total of 130 isolates of Candida albicans obtained from oral, vaginal and skin sites, were biotyped using the API 20C sugar assimilation system. One major biotype accounted for 75% of the isolates, while 12 minor biotypes accounted for the rest. The API 20C system may therefore be useful in supplementing other biotyping schemes of C. albicans available at present. 相似文献
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Abstract An isoprotein of enolase from the yeast Saccharomyces cerevisiae was reported to be a heat shock protein. The possible role of the C. albicans enolase as a heat shock protein was therefore investigated. The de novo synthesis of C. albicans enolase protein and mRNA did not increase during heat stress, but remained constitutively expressed. Amino acid similarity to the heat shock proteins suggests that although the C. albicans enolase is not a classical heat shock protein, it may be a memberof a group of constitutively expressed, structurally related proteins, the heat shock cognate proteins. 相似文献
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目的检测家族传播的口腔白色念珠菌基因多态性。方法采集35个家庭(119个样本)的口腔牙菌斑,采用PCR ITS1-ITS2基因分型方法,检测、分析家族传播的口腔白色念珠菌基因多态性。结果 18个家庭(18/35,61%),34个样本(34/119,28.6%)有白色念珠菌感染,11个家庭存在家族传播(11/18,61%)。在5个母子(父子)垂直传播的家庭成员中,白色念珠菌基因型均不一致。在3个呈水平传播的家庭成员中,两家基因型一致,1家不一致。在3个垂直-水平传播的家庭成员中,两家基因型一致,1家不一致。白色念珠菌家族传播基因型差异有显著统计学意义(χ2=26.571,P〈0.01)。白色念珠菌感染与年龄、性别、学历、吸烟、饮酒、义齿和龋病均无显著相关。结论白色念珠菌在口腔定植,受宿主自身遗传背景影响较大,在家族垂直传播中呈明显的基因多态性。呈水平传播的白色念珠菌菌种具有较高的传染性,基因型可保持不变。 相似文献
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目的 应用阴道细菌培养与光镜细胞学检查相结合的方法,研究定菌生对阴道念珠菌感染的菌群失调的调整作用。方法 以小鼠为实验对象,用盐酸林可霉素造成阴道菌群失调,并将分离的念珠菌接种到小鼠阴道内,造成小鼠阴道念珠菌感染模型,分别采用定菌生、抗真菌+定菌生及抗真菌(制霉菌素)治疗1疗程后,取其阴道分泌物进行念珠菌及乳杆菌的菌群分析,并同时进行分泌物镜检,取阴道组织标本做病理组织学检查。结果 模型组小鼠阴道内主要细菌数量乳杆菌显著下降(P〈0.01).出现阴道红肿、分泌物多呈块状和阴道黏膜充血等念珠菌阴道炎的典型症状,分泌物涂片镜检查到白细胞及念珠菌,而定菌生组和定菌生+制霉菌素组治疗的小鼠,阴道黏膜与健康对照组的阴道黏膜基本相同,阴道内主要菌群——乳杆菌的数量恢复正常,阴道内念珠菌显著降低,与自然恢复组相比差异有极显著性(P〈0.01),与制霉菌素处理比差异也有显著性,治疗效果明显好于制霉菌素。结论 定菌生能阻止念珠菌对阴道上皮的粘附作用,能调整阴道的菌群,对阴道黏膜有一定的修复功能,是治疗念珠菌性阴道炎有效的微生态调节剂。 相似文献
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Verónica Veses Manuel Casanova Amelia Murgui Neil A.R. Gow & José P. Martínez 《FEMS yeast research》2009,9(2):293-300
The human fungal pathogen Candida albicans undergoes reversible morphogenetic transitions between yeast, hyphal and pseudohyphal forms. The fungal vacuole actively participates in differentiation processes and plays a key role supporting hyphal growth. The ABG1 gene of C. albicans encodes an essential protein located in the vacuolar membranes of both yeast and hyphae. Using fluorescence microscopy of a green fluorescent protein-tagged version of Abg1p, a fraction of the protein was detected in hyphal tips, not associated with vacuolar membranes. Live cell imaging of emerging germ tubes showed that Abg1p migrated to the polarized growth site and colocalized with endocytic vesicles. Phenotypic analysis of a methionine-regulated conditional mutant confirmed that Abg1p is involved in endocytosis. 相似文献