Biology subjects

Sandstrom, S.

Publications and source records attributed to Sandstrom, S..

3 recordsLinked to original sources

bioRxiv2024

The Porcine Skin Microbiome Exhibits Broad Fungal Antagonism

The skin and its microbiome function to protect the host from pathogen colonization and environmental stressors. In this study, using the Wisconsin Miniature Swine model, we characterize the porcine skin fungal and bacterial microbiomes, identify bacterial isolates displaying antifungal activity, and use whole-genome sequencing to identify biosynthetic gene clusters encoding for secondary metabolites that may be responsible for the antagonistic effects on fungi. Through this comprehensive approach of paired microbiome sequencing with culturomics, we report the discovery of novel species of Corynebacterium and Rothia. Further, this study represents the first comprehensive evaluation of the porcine skin mycobiome and the evaluation of bacterial-fungal interactions on this surface. Several diverse bacterial isolates exhibit potent antifungal properties against fungal pathogens in vitro. Genomic analysis of inhibitory species revealed a diverse repertoire of uncharacterized biosynthetic gene clusters suggesting a reservoir of novel chemical and biological diversity. Collectively, the porcine skin microbiome represents a potential unique source of novel antifungals. HighlightsO_LIPorcine skin bacterial communities are consistent with previous reports on porcine and human skin. C_LIO_LIFungal community composition resembles mycobiomes from other mammalian skin, but not human skin. C_LIO_LIBacteria isolated from porcine skin have antimicrobial and particularly strong antifungal activity in vitro. C_LIO_LIDiscovered three new Corynebacterium species and one new Rothia species. C_LI

microbiology↗

bioRxiv2022

Sweat and sebum preferences of the human skin microbiota

The microorganisms that inhabit human skin, collectively termed the skin microbiome, must overcome numerous challenges that typically impede microbial growth, including low pH, osmotic pressure, and low nutrient availability. Yet, the skin microbiota thrive on the skin and have adapted to these stressful conditions. Limited skin nutrients are available for microbial use in this unique niche, including those from host-derived sweat, sebum, and corneocytes. Here, we have developed physiologically-relevant, skin-like growth media that is composed of compounds present in human sweat and sebum. We find that skin-associated bacterial species exhibit unique growth profiles in different concentrations of sweat and sebum. The majority of strains evaluated demonstrate a preference for high sweat concentrations, while sebum preference is highly variable, suggesting that the capacity for sebum utilization may be an important driver of skin microbial community structure. Furthermore, these findings provide experimental rationale for why different skin microenvironments harbor distinct microbiome communities. In all, our study further emphasizes the importance of studying microorganisms in an ecologically-relevant context, which is critical for our understanding of their physiology, ecology, and function on the skin.

microbiology↗

bioRxiv2022

lsaBGC provides a comprehensive framework for evolutionary analysis of biosynthetic gene clusters within focal taxa

We developed lsaBGC, a bioinformatics suite that introduces several new methods to expand on the available infrastructure for genomic and metagenomic-based comparative and evolutionary investigation of biosynthetic gene clusters (BGCs). Through application of the suite to four genera commonly found in skin microbiomes, we uncover multiple novel findings on the evolution and diversity of their BGCs. We show that the virulence associated carotenoid staphyloxanthin in Staphylococcus aureus is ubiquitous across the Staphylococcus genus but has largely been lost in the skin-commensal species Staphylococcus epidermidis. We further identify thousands of novel single nucleotide variants (SNVs) within BGCs from the Corynebacterium tuberculostearicum sp. complex, which we describe here to be a narrow, multi-species clade that features the most prevalent Corynebacterium in healthy skin microbiomes. Although novel SNVs were approximately ten times as likely to correspond to synonymous changes when located in the top five percentile of conserved sites, lsaBGC identified SNVs which defied this trend and are predicted to underlie amino acid changes within functionally key enzymatic domains. Ultimately, beyond supporting evolutionary investigations, lsaBGC provides important functionalities to aid efforts for the discovery or synthesis of natural products.

microbiology↗