Clinical and pathogenic analysis of Malassezia folliculitis in Nantong and Nanjing area / 中华皮肤科杂志

ObjectiveTo investigate the predisposing factors and pathogenic fungal species of Malassezia folliculitis in different geographical areas and body sites.MethodsTotally,241 patients diagnosed with Malassezia folliculitis were asked to complete a questionnaire.The content of hair follicles was obtained and subjected to fungal smear and culture examination.Fungal species were identified according to morphological,physiological and biochemical features.Results Of the 241 patients with Malassezia folliculitis,204 (84.65％) were positive for smear examination.A total of 259 specimens were collected from these patients,and fungal culture grew 213(82.24％) strains,of which,209 belonged to Malassezia species,4(1.54％) to Candida species.Among the 209 Malassezia strains,186 were activated and subjected to species identification which resulted in 6 species,including M.furfur (111 strains,59.68％ ),M.sloofiae (43 strains,23.12％ ),M.sympodialis (17 strains,9.14％),M.globosa (9 strains,4.84％),M.pachydermatis (4 strains,2.15％),and M.obtuse(2 strains,1.08％ ).Of the pathogenic fungi of Malassezia folliculitis,M.furfur predominated in the chest,back,abdomen,face and neck,M.sloofiae in the upper limbs,shoulders and vertex,M.globosa in the lower limbs.There were obvious differences in the distribution of pathogenic fungal species at different body sites in a same host,and M.furfur with M.sloofiae or M.sympodialis appeared to be the most common pathogens.ConclusionsIn this study,6 Malassezia species are identified in patients with Malassezia folliculitis in Nantong and Nanjing area,M.furfur and M.sloofiae appear to be the dominant pathogens.

Comparison of broth microdilution and agar dilution methods for antifungal susceptibility testing of Malassezia speciesin vitro / 中华皮肤科杂志

Objective To compare broth microdilution and agar dilution methods for in vitro testing of activities of fluconazole,ketoconazole and itraconazole against clinical Malassezia isolates.Methods Broth microdilution and agar dilution methods were used to determine the minimal inhibitory concentration(MIC)of fluconazole,ketoconazole and itraconazole for 27 clinical strains(5 species)of Malassezia.Results The minimal inhibitory concentration(MIC)ranges of fluconazole,ketoconazole and itraconazole were 0.25-≥64 mg/L,≤0.03-0.5 mg/L and ≤0.03-0.125 mg/L respectively as shown by broth microdilution method,2-≥64 mg/L,≤0.03-0.5 mg/L and ≤0.03-0.25 mg/L respectively as revealed by agar dilution method.Both methods demonstrated that itraconazole possessed the strongest activity against Malassezia species,followed by ketoconazole and fluconazole.The agreement rate in MICs between the two methods was 78.8％,85.2％ and 88.9％,respectively for fluconazole,ketoconazole and itraconazole,with the intraclass correlation coefficients (ICCs)being 0.88,0.80 and 0.76 respectively.Conclusions Fluconazole,ketoconazole and itraconazole are highly active against Malassezia species in vitro,and itraconazole is the most active.Broth microdilution and agar dilution method coincide well in,and are applicable for,the antifungal susceptibility testing of Malassezia species in vitro.