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Onychomycosis is a common fungal infection of the nails, predominantly caused by dermatophytes and is a notoriously difficult condition to treat. Thus, the objective of the present study was to evaluate and compare, in vitro, the efficacy of different applied ozone dosages against the main fungi that cause onychomycosis. Dermatophyte fungi Trichophyton rubrum (ATCC 28,188) and Microsporum gypseum (ATCC 24,102) were incubated at 28 °C for 14 days. Treatments were divided into nine experimental groups according to applied ozone dosages: Control Group 0 mg/m2: fungi were cultured but received no treatment; cultured fungi that received ozone therapy for 157, 314, 471, 628, 785 943, 1100 and 1257 mg/m2. The main results indicate that topical ozone therapy effectively reduced the germination percentage of T. rubrum and M. gypseum in all experimental periods, achieving a complete eradication with a treatment time of 628 and 1257 mg/m2, respectively. In conclusion, ozone therapy used topically with an applied ozone dosage of 628 mg/m2 for T. rubrum and 1257 mg/m2 for M. gypseum promoted antifungal action on the main dermatophytes responsible for critical complications of onychomycosis. Therefore, ozone therapy can be proposed as an adjuvant for dermatological treatments [ABSTRACT FROM AUTHOR]

The interspecific thermotolerance of several species of entomopathogenic fungi was evaluated based on the conidial water affinity. The species were divided between hydrophilic and hydrophobic conidia. The species with hydrophobic conidia wereBeauveria bassiana(ARSEF 252),Metarhizium brunneum(ARSEF 1187),Metarhizium robertsii(ARSEF 2575),Isaria fumosorosea(ARSEF 3889) andMetarhizium anisopliaes.l. (ARSEF 5749). The species with hydrophilic conidia wereTolypocladium cylindrosporum(ARSEF 3392),Tolypocladium inflatum(ARSEF 4877),Simplicillium lanosoniveum(ARSEF 6430),Lecanicillium aphanocladii(ARSEF 6433),S. lanosoniveum(ARSEF 6651),Aschersonia placenta(ARSEF 7637) andAschersonia aleyrodis(ARSEF 10276). The conidial surface tension of each isolate was also studied. Conidial suspensions were exposed to 38, 41 or 45 °C. After exposure, the suspensions were inoculated on media and conidial germination was evaluated. Considerable differences in thermotolerance were found among the 12 entomopathogenic fungal species. Species with hydrophobic conidia were generally more thermotolerant than species with hydrophilic conidia. All isolates with hydrophobic conidia showed higher conidial surface tension than the isolates with hydrophilic conidia. [ABSTRACT FROM AUTHOR]

Light conditions during mycelial growth are known to influence fungi in many ways. The effect of visible-light exposure during mycelial growth was investigated on conidial tolerance to UVB irradiation and wet heat of Metarhizium robertsii, an insect-pathogenic fungus. Two nutrient media and two light regimens were compared. Conidia were produced on (A) potato dextrose agar plus yeast extract medium (PDAY) (A1) under dark conditions or (A2) under continuous visible light (provided by two fluorescent lamps with intensity 5.4 W m). For comparison, the fungus was also produced on (B) minimal medium (MM) under continuous-dark incubation, which is known to produce conidia with increased tolerance to heat and UVB radiation. The UVB tolerances of conidia produced on PDAY under continuous visible light were twofold higher than conidia produced on PDAY medium under dark conditions, and this elevated UVB tolerance was similar to that of conidia produced on MM in the dark. The heat tolerance of conidia produced under continuous light was, however, similar to that of conidia produced on MM or PDAY in the dark. Conidial yield on PDAY medium was equivalent when the fungus was grown either under continuous-dark or under continuous-light conditions. [ABSTRACT FROM AUTHOR]