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Biomedical subjects

A B Macura

Publications and source records attributed to A B Macura.

At least 19 recordsLinked to original sources

Characterization of pathogenetic determinants of Candida albicans strains.

The study was an attempt to correlate phenotypic pathogenetic determinants of clinical Candida albicans strains with their genotype as determined by PCR fingerprinting. A total of 25 C. albicans strains was tested. Adherence capacity, hydrophobicity and proteinase production were compared with the genotypes of the particular Candida strains. The fungal strains represented eleven genotypes. No correspondence relationship was found between genotype and the markers of pathogenicity.

Candida albicans↗

[Antifungal activity of fluconazole in vitro].

The susceptibility of 97 fungal strains to fluconazole was evaluated using the dilution method. Forty-three of the strains were C. albicans, fifty-three other Candida species and one S. cerevisiae. The MIC values varied from 0.1 mg/l to 100 mg/l. However, the growth of 75.2% of the strains was considerably inhibited at 0.1 mg/l. Forty-nine strains were tested using both the dilution and disk-diffusion methods. The findings were consistent. The latter method may be performed on YNB medium and is of practical value.

Candida↗

Changes in actin cytoskeleton are involved in the cytopathic action of Candida albicans upon human skin fibroblasts.

The infection of human skin fibroblasts grown in culture with Candida albicans causes the death of infected cells, as assayed with the trypan blue exclusion test. The cell death is preceded by: (1) an attachment of germ tubes to the perinuclear surface of fibroblasts; (2) the disappearance of stress fibers and the disorganization of F-actin cytoskeleton and (3) cell rounding and detachment from the substratum. The results provide evidence for the role of F-actin cytoskeleton as a target in the cytopathic activity of C. albicans against human skin fibroblasts.

Actins↗

In vitro susceptibility of dermatophytes to antifungal drugs: a comparison of two methods.

BACKGROUND: There is an evidence that some fungal strains are resistant to certain antimycotic drugs with resulting therapeutic failures. Unlike testing of antibacterial agents, the activity of these drugs against the given fungal strains is not tested routinely. The paper presented is an approach to such a procedure. METHODS: The minimum inhibitory concentration (MIC) values obtained using the dilution method were compared with the diameters of growth inhibition zones using the disk-diffusion method. Seven antifungal drugs (griseofulvin, natamycin, naftifine, clotrimazole, bifonazole, miconazole, ketoconazole) were tested with 80 fungal strains, including Trichophyton rubrum, T. mentagrophytes, Microsporum canis, and Epidermophyton floccosum. RESULTS: The majority of fungal strains were inhibited by griseofulvin at concentrations not exceeding 10 mg/L. The least susceptible was T. mentagrophytes. The most effective drug was naftifine, and the least effective was natamycin. Naftifine inhibited 98.75% of the strains tested at a concentration not exceeding 1.0 mg/L. An increase of the MIC value was accompanied by a decrease in the growth inhibition diameter. The relation was statistically significant. CONCLUSIONS: T. rubrum strains are more susceptible to antifungal drugs than T. mentagrophytes. Naftifine proved to be the most effective drug in dermatophytoses. Natamycin is a useful drug against yeast-like fungi but not against dermatophytes. The disk-diffusion method of fungal susceptibility assessment yields data consistent with results obtained from the dilution method and is recommended for routine use because of its simplicity.

Antifungal Agents↗

[Effect of Staphylococcal proteinase on adherence of Candida albicans to mucous membrane cells in vitro].

The study was aimed at evaluation of influence of staphylococcal proteinase on adherence of Candida albicans to the cheek mucous membrane cells. Epithelial cells were preincubated with the enzyme which was followed by adherence tests. Significant increase of number of cells of Candida albicans adhering to epithelial cells preincubated with enzyme in concentrations of 10 micrograms/ml and 50 micrograms/ml, was detected. Staphylococcal serine protease seems to play an important role in mixed infections caused by fungi and bacteria.

Bacterial Adhesion↗

[Evaluation of susceptibility of dermatophytes to antifungal drugs].

A serial dilution and a disc method were used for evaluation of susceptibility of 50 dermatophyte strains belonging to the species Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis and Epidermophyton floccosum. Following drugs were investigated: griseofulvin, pimaricin, clotrimoxazole, miconazole, ketoconazole, biphonazole and naftifin. Application of two methods of testing resulted in high convergence of determinations. Naftifin was most effective and pimaricin least active. Among imidazole drugs, relatively high activity against dermatophytes was exhibited by clotrimoxazole and ketoconazole. Strain of Trichophyton rubrum were more susceptible to antifungal drugs than strains of Trichophyton mentagrophytes.

Antifungal Agents↗

[Adherence in vitro of Candida albicans to cheek mucous membrane cells in children with immune disorders].

Evaluation regarded adherence of a strain of Candida albicans to epithelium of cheek mucous membrane, obtained from 31 children aged between one and 14 years with disturbance of immunity and from 10 healthy children. All children were tested immunologically by determination of total leukocytosis, granulocytosis, absolute lymphocytosis, active and total rosette tests, spontaneous and stimulated nitroblue-tetrazolium (NBT) tests and immunoglobulin A, G and M levels in serum. Adherence of C. albicans in vitro of epithelial cells of cheek mucous membrane was significantly higher in children with disturbance of immunity as compared with healthy control group (p < 0.001).

Adolescent↗

[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.

Acetylglucosamine↗

[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).

Absorption↗

Influence of some carbohydrates and concanavalin A on the adherence of Candida albicans in vitro to buccal epithelial cells.

The influence of some carbohydrates and of a lectin, Concanavalin A on the in vitro adherence of ten C. albicans strains to buccal epithelial cells has been assessed. D-glucose, D-galactose and sucrose significantly (p less than 0.005) enhanced the adherence and so did D-mannose (p less than 0.025). Incubation with D-xylose, D-ribose, D-fructose, maltose, lactose and raffinose did not influence adherence. Pretreatment of the fungal cells or epithelial cells with glucose and mannose did not enhance adherence. Concanavalin A significantly inhibited the adherence of fungal cells to buccal epithelial cells both when it was added to the test medium (p less than 0.005) and when the fungal or epithelial cells were pretreated with it (p less than 0.001).

Candida albicans↗

[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.

Adhesiveness↗

[Effect of synthetic antifungal drugs on the adherence of Candida albicans to the mouth mucosa epithelium in vitro].

Ten Candida albicans strains were tested for their adherence to buccal epithelial cells in vitro in the presence of synthetic antimycotic drugs as 5-fluorocytosine, clotrimazole and ketoconazole. The drugs when applied in therapeutic concentrations inhibited adherence stronger than when applied in subinhibitory concentrations although in both situations the inhibition was statistically significant in comparison to control experiments without these drugs (p less than 0.01). The highest inhibition of adherence was seen with 5-fluorocytosine and the weakest with clotrimazole. Out of imidazole derived drugs strong inhibition of adherence was achieved with ketoconazole.

Adhesiveness↗