**1. Introduction**

*Staphylococcus epidermidis* is a commensal inhabitant of human and animal skin that rarely causes disease in healthy persons and animals. In recent years, however, *S. epidermidis* has been the most prevalent species isolated from device-associated infections [1]. The ability of biofilm formation by *S. epidermidis* is an important reason that investigators pay more attention to this emerging pathogen in recent years. It is reported that the major pathogenicity of *S. epidermidis* is attributed to its biofilm formed on the surface of infected tissues, which enhances bacterial resistance to antibiotics [2]. Biofilm formation by *S. epidermidis* involves two major steps. After finishing initial attachment, bacteria accumulate and form a multilayered architecture [3]. Bacteria develop biofilm by producing high-viscosity extracellular matrices including polysaccharides (EPS), proteins, and DNA (eDNA).

There is an increasing amount of biofilm research aimed at exploring how bacteria control their biofilm formation and to discover nontoxic compounds that can attenuate biofilm formation without allowing bacteria to develop drug resistance [4]. Special plants and Actinomycetes are both rich sources of bioactive substances, notably antibiotics, enzymes, enzyme inhibitors, and pharmacologically active

agents [4, 5]. Moreover, some Actinomycete species were reported to produce inhibitors against biofilm formation by *Staphylococcus aureus*, *Escherichia coli*, and *Pseudomonas aeruginosa* [6–9].

With this background, we aim to present the current knowledge on biofilm formation of *S. epidermidis* and review the control strategies to biofilm.
