Antifungal activity of some mediterranean algae

Summary The antifungal activity of 15 mediterranean algae species on some dermatophyte strains (Epidermophyton floccosum, Microsporum canis, M. gypseum and Trichophyton mentagrophytes) and pathogenic yeasts (Candida albicans, C. guillermondii, C. krusei, C. tropicalis and Torulopsis glabrata) has been tested following a modification of Aubert's technique.Among the algae species studied, Falkenbergia rufolanosa is the most active in front of all the fungi tested.     

Enhanced gene replacements in Ku80 disruption mutants of the dermatophyte, Trichophyton mentagrophytes

The frequency of targeted gene disruption via homologous recombination is low in the clinically important dermatophyte, Trichophyton mentagrophytes . The Ku genes, Ku70 and Ku80 , encode key components of the nonhomologous end-joining pathway involved in DNA double-strand break repair. Their deletion increases the homologous recombination frequency, facilitating targeted gene disruption. To improve the homologous recombination frequency in T. mentagrophytes , the Ku80 ortholog was inactivated. The nucleotide sequence of the Ku80 locus containing a 2788-bp ORF encoding a predicted product of 728 amino acids was identified, and designated as TmKu80 . The predicted TmKu80 product showed a high degree of amino acid sequence similarity to known fungal Ku80 proteins. Ku80 disruption mutant strains of T. mentagrophytes were constructed by Agrobacterium tumefaciens -mediated genetic transformation. The average homologous recombination frequency was 73.3 ± 25.2% for the areA/nit-2 -like nitrogen regulatory gene ( tnr ) in Ku80⁻ mutants, about 33-fold higher than that in wild-type controls. A high frequency ( c . 67%) was also obtained for the Tri m4 gene encoding a putative serine protease. Ku80 ⁻ mutant strains will be useful for large-scale reverse genetics studies of dermatophytes, including T. mentagrophytes , providing valuable information on the basic mechanisms of host invasion.     

Isolation of dermatophytes from clinically normal sites in patients with tinea cruris

Sixty patients clinically suspected of tinea cruris were studied by collecting skin scrapings from the site of their lesions and six clinically normal sites including the thighs, scrotum, crural clefts, natal cleft and the web between their 4th and 5th toes. Dermatophytes were detected in scrapings in 46 (77%) and by culture in 36 (60%) patients from lesions. Trichophyton rubrum was isolated from 32 and Epidermophyton floccosum from 4 patients. Dermatophytes were also isolated with maximum isolation from the scrotum, crural clefts and the natal cleft in that order. Thus, when tinea cruris is treated with topical antifungal agents they should be applied also to the potential carriage sites to prevent recurrence.