Cytotoxicity of Aspergillus strains isolated from the neonatal intensive care unit environment.

PURPOSE: It is essential in the medical care for immunocompromised patients that the environment should create minimal infection risk. Particularly, it concerns fungal infections. Fungi belonging to the Aspergillus genus are second frequent group of nosocomial pathogens producing opportunistic infections. MATERIAL AND METHODS: The objective of the study was evaluation of prevalence and cytotoxicity of selected Aspergillus strains isolated from the neonatal intensive care unit environment. During 5 consecutive days, 30 samples of indoor air and 120 imprints from the ward environment were collected. Cytotoxicity of 17 strains was evaluated using a MTT (3-(4,5-dimethylthiazol-2-yl) 2,5 diphenyltetrazolium bromide) test. RESULTS: Mean numbers of fungi in the indoor air varied from 50 to 2370 c.f.u.xm-3 while in the imprints from 0.04 to 8.83 c.f.u.xcm-2. Moulds were isolated from most of the materials. All of the 17 strains subject to MTT test were cytotoxic. CONCLUSION: All of the Aspergillus strains isolated from the neonatal intensive care unit were cytotoxic. Cytotoxic Aspergillus strains present in the environment of immunocompromised patients may be potentially dangerous to them.

Dermatophyte species in superficial mycoses in the Kraków district, Poland in the years 1972-2007.

Considerable changes in the dermatophyte spectrum have been observed in the past century. Hence, many authors point out the necessity of performing periodical overviews of the mycological flora producing mycoses in humans in a given area. Analysis of dermatophyte species was performed, which were isolated from the lesions in patients suspected of superficial mycosis and referred to the Department of Mycology. The materials were isolated from patients suspected of superficial mycosis from Kraków region from January 1, 1972 through December 31, 2007. A total of 4983 dermatophyte strains were isolated from 23 124 specimens, which amounts to 21.5%. The percentage of dermatophytes isolated in the past decade decreased to 13.1% in the year 2007. Trichophyton rubrum outnumbered Trichophyton mentagrophytes during the entire survey period: 62.4 vs. 33.5%. The participation of Microsporum canis amounted to 1.71% and that of Epidermophyton floccosum to 1.32%. The species M. canis appeared by the end of the 1980s. The remaining dermatophyte species comprised 1% of the isolates. A considerable decrease in dermatophyte isolations has been observed since 2000. Trichophyton rubrum outnumbered T. mentagrophytes during the entire period of study. The percentages of T. rubrum and T. mentagrophytes are decreasing while the percentages of other dermatophytes are slowly increasing.

Application of a diagnostic-therapeutic procedure using implant-supported dental prosthesis as a preventive therapy for candidiasis of upper gastrointestinal tract in complete denture users.

Our previous studies demonstrated that the use of acrylic based prosthesis in edentulous patients had a direct impact on the increased incidence of oral mycosis and further episodes of mycosis in the digestive tract. This dependency is associated with formation of a space between the surface of the prostheses and adhering mucosal membrane, where a specific micro environment is being formed, which - as stated - creates a superior breeding ground mainly for microorganisms of the genus Candida.

Environmental risk of mycosis in patients treated at an acquired immunodeficiency ward.

PURPOSE: Patients with acquired immunodeficiency are particularly predisposed to fungal infections. The purpose of the study was evaluation of the presence of fungi in the environment of a ward where Human Immunodeficiency Virus (HIV) positive and Acquired Immune Deficiency Syndrome (AIDS) patients were treated. MATERIALS AND METHODS: The evaluation of fungal presence in the indoor air and on the room walls at an acquired immunodeficiency ward in the University Hospital in Cracow was carried out in December 2006. Indoor air specimens were sampled using an aspiration method (a MAS 100 device) while imprints from the walls using Cont-Tact method (bioMèrieux) in the morning ad in the evening during five consecutive days. A total of sixty air specimens and thirty imprints from the walls were obtained. The fungi cultured from those specimens were analysed using standard mycological procedures. RESULTS: It was found out that the numbers of fungi sampled from the indoor air in the morning were significantly higher than those sampled in the evening. The average numbers of fungi isolated in the rooms inhabited by the patients varied from 55 c.f.u (colony forming units) x m(-3) to 490 c.f.u x m(-3) as calculated for the entire testing period. Fungi potentially pathogenic for persons with impaired immunity were found in all of the rooms: Aspergillus sp., Mucor sp., and yeast-like fungi Candida sp. CONCLUSION: Reduction of the numbers of potentially pathogenic bacteria, viruses and fungi in the indoor air should be a standard in the practice of medical staff (mainly epidemiological nurses).

Intensive care unit environment contamination with fungi.

PURPOSE: The purpose of the study was evaluation of the fungal presence in the environment of an intensive care unit. MATERIAL AND METHODS: The environment testing was carried out at a chest clinic intensive care unit in Cracow, in December 2004. The materials to mycological examinations were sampled simultaneously from indoor air and room walls in 15 rooms: air samples twice daily while samples from the walls once daily, for five days. The findings were processed statistically. The t-test (Student) and F-test (Snedecor) were used. The border value of significance was 0.05. RESULTS: No fungi were found in 6 air samples out of 150 taken in 15 rooms. The mean number of fungi in the particular rooms in the whole sampling period varied from 172 to 12 c.f.u. x m(-3). Out of 75 samples from the walls, fungi were present only in 19 of them. The mean numbers varied from 0 to 0.37 c.f.u. x cm(-2). The moulds Aspergillus sp., Penicillium sp. and Cladosporium sp. as well as yeast-like fungi Rhodotorula rubra, Candida sp. were most frequently isolated from the indoor air and the walls. CONCLUSION: Significant difference between the numbers of fungi sampled in the morning vs in the evening occurred on the first, third and fourth days of sampling (p < 0.001). Yeast-like fungi Rhodotorula rubra and moulds Aspergillus sp., Cladosporium sp., Penicillium sp. were isolated from indoor air in all of the rooms tested.

Evaluation of adhesive properties of Candida albicans isolated from the oral cavity in HIV positive patients.

The aim of the work was to compare adhesive properties of Candida albicans strains isolated from the oral cavity in HIV+ vs. HIV- persons. The materials were Candida albicans strains and buccal epithelial cells isolated from both HIV+ and HIV- persons. We applied the in vitro adherence test, primarily described by Kimura and Pearsall and modified by Macura. The strongest adherence was found between both fungi and epithelial cells isolated from a HIV+ person. The adherence of C. albicans isolated from HIV+ patients was significantly stronger to epithelium collected from HIV+ than HIV- persons.

[The susceptibility of Aspergillus and Penicillium to recent antimycotics]. / Ocena in vitro grzybów z rodzaju Aspergillus i Penicillium na nowe leki przeciwgrzybicze.

Fifty four mould strains (32 Aspergillus and 22 Penicillium) isolated from clinical materials were tested using dilution method. Two test media were used: Yeast Nitrogen Base (YNB) and Czapek Dox (CD). The following drugs were tested: amorolfine, cyclopirox, itraconazole, and terbinafine. In the dilution method, the drugs were tested at four contrentrations: 0.1 mg/l, 1 mg/l, 10 mg/l, and 100 mg/l. No matter which medium and/or drug was used, terbinafine turned out to be most effective. The drug at a conceatration of 1 mg/l inhibited 88.9% of the strains in the CD medium. The MIC values in the YNB medium varied from 0.1 mg/l through 100 mg/l, however, 50% of the strains were inhibited at 1 mg/l or less. Itraconazole revealed a fairly good in vitro antifungal action, particularly in the CD medium: 77.8% of the strains were inhibited at 10 mg/l or less. Aspergillus fumigatus and Aspergillus flavus were most susceptible to itraconazole. The MIC values of cyclopirox amounted to 100 mg/l for all of the strains in the CD medium but not in the YNB where they varied from 1 mg/l to 100 mg/l. Amorolfine was the least effective drug. Most of the strains were inhibited at a concentration of at least 100 mg/l. The findings give evidence that the susceptibility of Aspergillus and Penicillium to the particular drugs is different, and that the results are influenced by the test medium.

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.

[Antifungal activity of fluconazole in vitro]. / Przeciwgrzybicza aktywnosc flukonazolu 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.

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.

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.

[Effect of Staphylococcal proteinase on adherence of Candida albicans to mucous membrane cells in vitro]. / Wplyw proteinazy gronkowcowej na przyleganie grzybów Candida albicans do komórek blony sluzowej 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.

[Evaluation of susceptibility of dermatophytes to antifungal drugs]. / Ocena wrazliwosci dermatofitów na leki przeciwgrzybicze.

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.

[Adherence in vitro of Candida albicans to cheek mucous membrane cells in children with immune disorders]. / Adherencja in vitro Candida albicans do komórek blony sluzowej policzka dzieci z zaburzeniami odpornosci.

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).

[Effect of various components of the fungal cell wall on adhesion of Candida albicans to the mouth mucosa epithelium in vitro]. / Wplyw niektórych skladników sciany komórkowej grzybów na przyleganie Candida albicans do nablonka jamy ustnej 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.

[Hydrophobic and adhesive capacity of Candida strains isolated from patients with fungal infection]. / Hydrofobowosc i zdolnosc adherencji szczepów Candida wyizolowanych od ludzi chorych na grzybice.

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).