In vitro susceptibility of seven antifungal agents against dermatophytes isolated in Istanbul

Background/aim: Dermatophytes are the causative agents of dermatophytosis, which is a common disease worldwide that affects the hair, skin, and nails. Dermatophytes comprise more than 40 species in 3 genera: Microsporum, Trichophyton, and Epidermaphyton. In this study, we aimed to determine the effectiveness of seven antifungal agents: amphotericin B, terbinafine, itraconazole, voriconazole, ketoconazole, miconazole, and fluconazole. Materials and methods: A sensitivity study was performed using a microdilution method in accordance with the CLSI M38-A2 standards using isolates of Trichophyton rubrum (n = 55), Microsporum canis (n = 9), and Trichophyton interdigitale (n = 2), which were identified by sequencing the internal transcribed spacer region of the rDNA. Results: According to the results of antifungal sensitivity tests, the geometric mean (GM) minimum inhibitory concentration (MIC) against T. rubrum was 0.10 µg/mL for ketoconazole, 0.20 µg/mL for itraconazole, 0.07 µg/mL for miconazole, 0.48 µg/mL for fluconazole, 2.27 µg/mL for amphotericin B, 0.06 µg/mL for voriconazole, and 0.06 µg/mL for terbinafine. Conclusion: The most effective antifungal drugs were voriconazole and terbinafine, both of which had a GM MIC of 0.06 µg/mL.

Magnusiomyces capitatus Peritonitis in a Child With Acute Lymphocytic Leukemia as a Breakthrough Infection During Caspofungin Therapy.

Magnusiomyces capitatus is an emerging opportunistic fungal pathogen particularly in immunocompromised patients. We report a case of a M. capitatus peritonitis in child with acute lymphocytic leukemia as a breakthrough infection during caspofungin therapy. The possibility of breakthrough infections caused by M. capitatus must be taken into consideration, particularly in immunosupressed patients being treated for systemic fungal infections by caspofungin. Although there are no defined breakpoints for susceptibility testing of M.capitatus, minimal inhibitory concentration results can be helpful for therapy. Antifungal treatment with amphotericin B lipid complex plus flucytosine can be effective against infections caused by M. capitatus.

Virulence markers of opportunistic black yeast in Exophiala.

The black yeast genus Exophiala is known to cause a wide variety of diseases in severely ill individuals but can also affect immunocompetent individuals. Virulence markers and other physiological parameters were tested in eight clinical and 218 environmental strains, with a specific focus on human-dominated habitats for the latter. Urease and catalase were consistently present in all samples; four strains expressed proteinase and three strains expressed DNase, whereas none of the strains showed phospholipase, haemolysis, or co-haemolysis activities. Biofilm formation was identified in 30 (13.8%) of the environmental isolates, particularly in strains from dishwashers, and was noted in only two (25%) of the clinical strains. These results indicate that virulence factors are inconsistently present in the investigated Exophiala species, suggesting opportunism rather than pathogenicity.

[A case of urinary tract infection caused by Flavimonas oryzihabitans]. / Flavimonas oryzihabitans'in etken oldugu bir jriner sistem enfeksiyonu olgusu.

Flavimonas oryzihabitans is an uncommon bacterial species isolated from clinical specimens. In this report, a 53 years old female patient who had been followed up with the diagnosis of rectum cancer and renal failure for five and two years, respectively, was presented. F. oryzihabitans was isolated from the urine culture of the patient, and the clinical response to ofloxacin therapy was excellent even the urinary catheter has not been removed. Although this pathogen is mostly community aquired, it was found resistant to most of the antimicrobial agents tested. Since it was susceptible to fluoroquinolones and carbapenems, these antibiotics could be the drug of choice for the treatment of infections caused by F. oryzihabitans. The aim of this presentation was to withdraw attention to this bacterium which is thought to be the first urine isolate in our country.