The slime of coagulase-negative staphylococci: Biochemistry and relation to adherence

Abstract

In recent years, infections of implanted plastic devices by coagulase‐negative staphylococci have become a major cause of septicaemia in human patients. The causal bacterial species is usually Staphylococcus epidermidis and these organisms grow as a biofilm adherent to a solid surface. Several methods have been introduced to assess the mass of adherent bacteria and the slimy matrix in which they are embedded. Some methods measure total biofilm, others measure the organisms or the slime alone. In vitro, the type of medium, the atmosphere during incubation, and the nature of the solid surface, affect the quantity of biofilm that is formed. In most studies on the chemistry of the slime, the material used was formed on complex media solidified with agar. Contamination by ingredients of the media or by agar may not always have been recognised. Recent work with chemically defined medium (liquid or solidified with silica gel) shows that the slime is a mixture of about 80% (w/w) teichoic acid and 20% protein. Growth as a biofilm may protect the staphylococci from antibiotics. At present, the greatest success in preventing infection has come from improved surgical techniques during the insertion of implants.

Correlation between biofilm formation and production of polysaccharide intercellular adhesin in clinical isolates of coagulase-negative staphylococci

“…The chemical composition of the staphylococcal biofilms has been intensively investigated. Several authors consider PIA (Mack et al, 1996a), teichoic acid (Hussain et al, 1993) or proteins (Hussain et al, 1997) to be main components required for staphylococcal biofilm formation. It is assumed that staphylococcal strains isolated from infected sites -and particularly from prosthetic devices -should be able to form a biofilm (Bf+), produce PIA (PIA+), and possess the icaADBC operon (ica+).…”

Biofilms: Microbial Life on Surfaces

“…In the case of some gram-positive bacteria, such as the staphylococci, the chemical composition of EPS may be quite different and may be primarily cationic. Hussain et al (40) found that the slime of coagulase-negative bacteria consists of a teichoic acid mixed with small quantities of proteins.…”

Osteomyelitis and the role of biofilms in chronic infection

“…Early studies described the solid component of the glycocalyx as primarily composed of teichoic acids (80%) and staphylococcal and host proteins (Hussain et al, 1993). Host-derived proteins, such as fibrin, may be derived from the conversion of fibrinogen by the staphylococcal coagulase -prothrombin complex (Akiyama et al, 1997).…”