Genotypic and Phenotypic Characterization of Fecal Staphylococcus epidermidis Isolates Suggests Plasticity to Adapt to Different Human Body Sites

Abstract

Staphylococcus epidermidis is a commensal species that has been increasingly identified as a nosocomial agent. Despite the interest, little is known about the ability of S. epidermidis isolates to adapt to different ecological niches through comparisons at genotype or phenotype levels. One niche where S. epidermidis has been reported is the human gut. Here, we present three S. epidermidis strains isolated from feces and show that they are not phylogenetically distinct from S. epidermidis isolated from other human body sites. Both gut and skin strains harbored multiple genes associated with biofilm formation and showed similar levels of biofilm formation on abiotic surfaces. High-throughput physiological tests using the BIOLOG technology showed no major metabolic differences between isolates from stool, skin, or cheese, while an isolate from bovine mastitis showed more phenotypic variation. Gut and skin isolates showed the ability to metabolize glycine-conjugated bile acids and to grow in the presence of bile, but the gut isolates exhibited faster anaerobic growth compared to isolates of skin origin.

Intestinal Inflammation Breaks Established Immune Tolerance to a Skin Commensal

“…Even though S. epidermidis is excluded from the gut with increasing age, its presence during a critical window of immune education may facilitate establishment a largely tolerogenic intestinal memory CD4 + T cell pool (Knoop et al, 2018), matching that seen in skin (Scharschmidt et al, 2015). We found that intestinal levels of S. epidermidis increased during colitis, consistent with its ability to adapt and bloom under certain inflammatory conditions (Garcia-Gutierrez et al, 2020).…”

The Genome of Staphylococcus epidermidis O47

“…Comparative genomic analysis of this strain focused more on the antibiotic resistance and its virulence gene arsenal. A very recent study reported three S. epidermidis strains isolated from fecal sample of a healthy individual ( Garcia-Gutierrez et al, 2020 ). It was shown that these strains are not phylogenetically distinct from S. epidermidis isolated from other human body sites.…”

Gut microbial disruption in critically ill patients with COVID-19 associated pulmonary aspergillosis

“…Studies on the prevalence and function of S. epidermidis in the adult gut are scarce. It has been shown that strains of S. epidermidis from the gut or skin do not differ essentially in their ability to form biofilms and pathogenicity (34). A recent study has identified the gut as a reservoir and origin of bloodstream infection with S. epidermidis , thus challenging the informal dogma that this infection originates exclusively from the environment or the skin (35).…”