An Antimicrobial Staphylococcus Sciuri with Broad Temperature and Salt Spectrum Isolated from the Surface of the African Social Spider, Stegodyphus Dumicola

Some social arthropods engage in mutualistic symbiosis with antimicrobialcompound-producing microorganisms that provide protection against pathogens. Socialspiders live in communal nests and contain specific endosymbionts with unknown function.Bacteria are also found on the spiders’ surface, including prevalent staphylococci,which may have protective potential. Here we present the genomic and phenotypiccharacterization of strain i1, isolated from the surface of the social spider Stegodyphus dumicola. Phylogenomic analysis identified i1 asnovel strain of Staphylococcus sciuri within subgroup2 of three newly defined genomic subgroups. Further phenotypic investigations showedthat S. sciuri i1 is an extremophile that can grow ata broad range of temperatures (4 °C–45 °C), high salt concentrations (up to 27%), andhas antimicrobial activity against closely related species. We identified a lactococcin972-like bacteriocin gene cluster, likely responsible for the antimicrobial activity,and found it conserved in two of the three subgroups of S.sciuri. These features indicate that S.sciuri i1, though not a specific symbiont, is well-adapted to survive onthe surface of social spiders and may gain a competitive advantage by inhibiting closelyrelated species.