Epidermidis

Part of speech: noun

Definitions

1. A species of bacteria commonly found on human skin that can be harmless or occasionally lead to infections
2. A type of coagulase-negative staphylococcus present in the human microbiota, often involved in medical device-related infections
3. A microorganism typically residing on the skin surface; it plays a role in preventing pathogenic organisms but can also cause opportunistic infections

Etymology: Staphylococcus epidermidis gets its name from a simple piece of Greek-and-Latin construction. "Staphylococcus" comes from the Greek "staphylē" ("bunch of grapes") and "kokkos" ("berry"), a description of how these round cells cluster under the microscope. The species epithet "epidermidis" is a Latinized form of the Greek "epidermis," meaning "outer skin," built from "epi" ("upon") and "derma" ("skin"). Since the bacterium lives on the epidermis, the name is essentially a label for where it was found. The species was first described in 1884 by the German bacteriologist Albert Ludwig Sigismund Neisser, and the scientific name was formalized under the genus "Staphylococcus," which was itself introduced by Ferdinand Julius Cohn. The epithet was therefore a 19th-century coinage, not a term the ancient Greeks or Romans could have used for this organism, though it draws on their vocabulary.