Evaluation of the effect of soil bacteria extracts on growth ofpathogenicity of fluconazole resistant strains of Candida tropicalis

Background and Aim : Background: Candida tropicalis has emerged as one of the most importantCandida species. It has been widely considered the second most virulent Candida species, onlypreceded by C. albicans. Besides, this species has been recognized as a very strong biofilmproducer, surpassing C. albicans in most of the studies. the azole antifungals are the most frequentclass used to treat Candida infection. Azole antifungals such as fluconazole are often preferred forthe treatment of many Candida infections. However, resistance to azoles exists among severalCandida species. The aim of this study is to investigate the effectiveness of the antifungal activityof the extract of bacteria isolated from the soil, which is an effective treatment against Candidatropicalis resistant to fluconazole.Methods : Method: In this test, we cultured Streptomyces isolated from the soil. The aqueousextract of the bacteria with a concentration of ۰.۰۱۸ mg/ml in the range of ۱.۸ μg to ۰.۰۰۰۹μg wasused on fluconazole-resistant Candida tropicalis isolated from patients with Oropharyngealcandidiasis was treated with the Micro Broth Dilution method. And we also used fluconazole witha concentration of ۶۴ mg/ml as a control.Results : Result: Treatment with the extract of bacteria isolated from soil, genus Streptomyces,with a concentration of ۰.۰۱۸ mg/ml showed a great fungicidal effect on C. tropicalis resistant tofluconazole. The minimum inhibitory concentration (MIC) was ۰.۰۰۷۲ ?g. On the other hand,fluconazole with a concentration of ۶۴ mg/ml had no effect on this fungus and it showed significantgrowth.Conclusion : Conclusion: These findings show that the aqueous extract of bacteria isolated fromsoil, especially Streptomyces genus, is more effective than fluconazole and is a promisingtreatment against fluconazole-resistant Candida tropicalis.

کلیدواژه ها:

Candida tropicalis ، Streptomyces ، oropharyngeal candidiasis ، fluconazole