Animated coloured scanning electron micrograph (SEM) of Staphylococcus warneri, coccoid, Gram-positive prokaryote. Staphylococcus warneri is a common commensal bacterium found on the skin of humans and animals. It is a coagulase-negative Staphylococcus sp. that rarely causes disease but it may cause infection in immunocompromised patients. It occasionally has been associated with cases of septicaemia and bacteraemia. Staphylococcus warneri is sensitive to the antibiotic, vancomycin.