Dataset Information

Taxonomic Characterizations of Soil Streptomyces cavourensis DW102 and Its Activity against Fungal Pathogens.

ABSTRACT:

Background

Streptomyces spp. are soil bacteria that have commercial value from which numerous secondary metabolites such as antifungal compounds have been derived. There is growing concern that antifungal resistance is on the rise, and soil Streptomyces from various geographical places might produce novel antifungal molecules. The aim of this study was to characterize and identify the actinomycetes strain namely Streptomyces isolate DW102, and to evaluate its antimicrobial activity against nosocomial fungal pathogens.

Materials and methods

Streptomyces isolate DW102 was identified based on morphological, cultural, physiological, and biochemical properties, together with 16S rRNA sequence. Its antifungal activity was determined by agar well-diffusion assays.

Results

The isolate DW102 phenotypic and molecular characterization was identified as Streptomyces cavourensis DW102 and sequencing results were deposited in GenBank under accession number MK508855. Furthermore, the fermented broth of Streptomyces isolate DW102 inhibited the growth of Aspergillus niger and Candida albicans in vitro.

Conclusions

Phenotypic, molecular, and phylogenetic analysis of DW102 identified the strain to be S. cavourensis. The antifungal assay showed that DW102 fermentation broth was active against both C. albicans and A. niger in vitro. Further studies are required to use the Streptomyces isolate DW102 as a promising source for the development of antifungal drugs.

SUBMITTER: Sheik GB

PROVIDER: S-EPMC7909053 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Invasive fungal infections due to Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans constitute a substantial threat to hospitalized immunocompromised patients. Further, the presence of drug-recalcitrant biofilms on medical devices and emergence of drug-resistant fungi, such as Candida auris, introduce treatment challenges with current antifungal drugs. Worse, currently there is no approved drug capable of obviating preformed biofilms, which increase the chance of infection relapses. Here, we screened a small-molecule New Prestwick Chemical Library, consisting of 1,200 FDA-approved off-patent drugs against C. albicans, C. auris, and A. fumigatus, to identify those that inhibit growth of all three pathogens. Inhibitors were further prioritized for their potency against other fungal pathogens and their ability to kill preformed biofilms. Our studies identified the bis-biguanide alexidine dihydrochloride (AXD) as a drug with the highest antifungal and antibiofilm activity against a diverse range of fungal pathogens. Finally, AXD significantly potentiated the efficacy of fluconazole against biofilms, displayed low mammalian cell toxicity, and eradicated biofilms growing in mouse central venous catheters in vivo, highlighting its potential as a pan-antifungal drug.IMPORTANCE The prevalence of fungal infections has seen a rise in the past decades due to advances in modern medicine leading to an expanding population of device-associated and immunocompromised patients. Furthermore, the spectrum of pathogenic fungi has changed, with the emergence of multidrug-resistant strains such as C. auris High mortality related to fungal infections points to major limitations of current antifungal therapy and an unmet need for new antifungal drugs. We screened a library of repurposed FDA-approved inhibitors to identify compounds with activities against a diverse range of fungi in varied phases of growth. The assays identified alexidine dihydrochloride (AXD) to have pronounced antifungal activity, including against preformed biofilms, at concentrations lower than mammalian cell toxicity. AXD potentiated the activity of fluconazole and amphotericin B against Candida biofilms in vitro and prevented biofilm growth in vivo Thus, AXD has the potential to be developed as a pan-antifungal, antibiofilm drug.