Staphylococcus saccharolyticus: An Overlooked Human Skin Colonizer

Abstract

Coagulase-negative staphylococcal species constitute an important part of the human skin microbiota. In particular, facultative anaerobic species such as <i>Staphylococcus epidermidis</i> and <i>Staphylococcus capitis</i> can be found on the skin of virtually every human being. Here, we applied a culture-independent amplicon sequencing approach to identify staphylococcal species on the skin of healthy human individuals. While <i>S. epidermidis</i> and <i>S. capitis</i> were found as primary residents of back skin, surprisingly, the third most abundant member was <i>Staphylococcus saccharolyticus</i>, a relatively unstudied species. A search of skin metagenomic datasets detected sequences identical to the genome of <i>S. saccharolyticus</i> in diverse skin sites, including the back, forehead, and elbow pit. Although described as a slow-growing anaerobic species, a re-evaluation of its growth behavior showed that <i>S. saccharolyticus</i> can grow under oxic conditions, and, in particular, in a CO₂-rich atmosphere. We argue here that <i>S. saccharolyticus</i> was largely overlooked in previous culture-dependent and -independent studies, due to its requirement for fastidious growth conditions and the lack of reference genome sequences, respectively. Future studies are needed to unravel the microbiology and host-interacting properties of <i>S. saccharolyticus</i> and its role as a prevalent skin colonizer.