Molecular basis of Staphylococcus epidermidis infections

Abstract

Staphylococcus epidermidis is the most important member of the coagulase-negative staphylococci and one of the most abundant colonizers of human skin. While for a long time regarded as innocuous, it has been identified as the most frequent cause of device-related infections occurring in the hospital setting and is therefore now recognized as an important opportunistic pathogen. S. epidermidis produces a series of molecules that provide protection from host defenses. Specifically, many proteins and exopolymers, such as the exopolysaccharide PIA, contribute to biofilm formation and inhibit phagocytosis and the activity of human antimicrobial peptides. Furthermore, recent research has identified a family of pro-inflammatory peptides in S. epidermidis, the phenol-soluble modulins (PSMs), which have multiple functions in immune evasion and biofilm development, and may be cytolytic. However, in accordance with the relatively benign relationship that S. epidermidis has with its host, production of aggressive members of the PSM family is kept at a low level. Interestingly, in contrast to Staphylococcus aureus with its large arsenal of toxins developed for causing infection in the human host, most if not all “virulence factors” of S. epidermidis appear to have original functions in the commensal lifestyle of this bacterium.

Implementation of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry in Routine Clinical Laboratories Improves Identification of Coagulase-Negative Staphylococci and Reveals the Pathogenic Role of Staphylococcus lugdunensis

“…Previous reports have shown that MALDI-TOF MS is a reliable method to identify Staphylococcus at the species level; however, questions regarding the impact of such methods in clinical settings remain uncertain (9). Staphylococcus epidermidis is probably the major CoNS species causing nosocomial infections, although other CoNS, such as S. lugdunensis, S. schleiferi, and S. saprophyticus, have been reported as even more pathogenic in a range of both nosocomial and communityacquired infections (10)(11)(12)(13).…”

Virulence factors and antimicrobial resistance of coagulase-negative staphylococci isolated from drinking water

“…Investigation of biofilms occurring in a public drinking water distribution system in Romania revealed the presence of S. warneri and S. vitulinus [43]. Based on results of those studies, S. epidermidis -an important nosocomial opportunistic pathogen [44,45] -is the most frequently isolated species among staphylococci occurring in the aquatic environment.…”

Emergence of Staphylococcus epidermidis Clinical Isolates with Resistance to Both Mupirocin and Fusidic Acid

“…Staphylococcus epidermidis is part of the human epithelia microflora and usually has a benign relationship with the host. Colonization with S. epidermidis contributes to the maintenance of a healthy skin flora by competition with potentially harmful microorganisms (2). In the recent decades, however, with increasing use of indwelling or implanted medical devices and the increase of multi-morbid, elderly, and immunocompromised patients, S. epidermidis has emerged as an important opportunistic pathogen responsible for hospital-acquired infections, especially biofilm-associated infections (1).…”

“…Staphylococcus epidermidis is one of the often encountered biofilm-producing bacteria and the establishment of S. epidermidis as a nosocomial pathogen mainly depends on biofilm formation (2). Polysaccharide intercellular adhesin (PIA) encoded by icaADBC operon is a mediator of biofilm formation in S. epidermidis (3).…”