Mechanism of Compact-colony Formation by Strains of Staphylococcus aureus in Serum Soft Agar

Abstract

S U M M A R YCompact-colony forming active substance (CCFAS), the material responsible for the compact colonies of Staphylococcus aureus observed in serum soft agar, was found to be an alkaline-stable, associated polysaccharide containing galactose, N-acetylglucosamine, ribitol, phosphorus and a small quantity of alanine. This substance, when extracted from strains unable to produce protein A and clumping factor, was able to absorb the serum-reacting factor whereas a teichoic acid preparation of one strain could not. The formation of CCFAS was unaffected by the age of the cells, whereas when staphylococci were cultured at alkaline pH, young cells produced more clumping factor than old ones. Both fibrinogen and its degradation products were capable of inducing compact colonies in a strain of S. aureus. The ability of human sera to interact in compact-colony formation was independent of the immunoglobulin content. Thus neither protein A, clumping factor, nor teichoic acid participate in the CCFAS reaction.

Mechanisms of resistance of staphylococci grown in plasma to polymorph bactericidins

“…Several explanations may be advanced for these inconclusive results. First, it could be due to the production, by these S. aureus variants, of a cell wall polysaccharide known as the Compact Colony Forming Active Substance (CCFAS, Yoshida, Ohtomo & Minegishi, 1975), which can cause a clotting reaction with fibrinogen (Yoshida, Ohtomo & Minegishi, 1977, 1980 and which has been extracted from at least one S. epidermidis strain (Yoshida, Ohtomo & Usui, 1978), resulting in conversion irrespective of which of clumping factor or free coagulase they lacked. Other reasons could be that plasma components reacted through the capsular substance of the Smith diffuse strain, that the fibrinogen (and indeed the other plasma components and serum) solutions used might not have been 1000% pure or that a time-dependent mechanism which is unrelated to a coagulase or clumping factor-fibrinogen interaction was also involved.…”

Isolation of a Serologically Different Compact‐Colony‐Forming Active Substance from Strains of Staphylococcus aureus

“…In the past, Yoshida and Minegishi (10) and Yoshida et al (11) regarded alkaline dependent polysaccharide substance as a cellular factor reacting with fibrin monomer, fibrinogen degradation products, and fibronectin (7) involved in serum for the compact-colony formation in SSA. Highly purified CCFAS clots plasmas by paracoagulation (4,6).…”

“…In the past, Yoshida et al (11) postulated that compact-colony formation of Staphylococcus aureus strains in serum-soft agar (SSA) medium was the results of reaction between an alkaline-dependent polysaccharide located on the cell surface and fibrin monomer, fibrinogen degradation products, and fibronectin involved in serum (7,12,13). Compact-colony-forming active substance (CCFAS) (9) was capable of clotting various species of animal plasmas (3,5).…”

Comparison of compact colony-forming activity and paracoagulation activity of strains ofStaphylococcus aureus in serum and plasmas of various animals

“…We have previously shown an alkali-dependent polysaccharide (substance 1), composed of galactose and 2-amino-2-deoxy-D-galacturonic acid, isolated from staphylococci cell surfaces to be involved in compact colony formation in SSA and paracoagulation (PC) with fibrinogen (Yoshida et al 1975(Yoshida et al , 1977(Yoshida et al , 1978Usui et al 1982;Ohtomo et al 1985). It was, therefore, also assumed that adsorption of the converting activity (change of diffuse to compact growth) in SSA of serum and fibrinogen could be interpreted as polymerization of fibrinogen, FDP and/or soluble fibrin monomer and that the relative compact colony-forming activity of the S. aureus strain would correlate with the relative activity of fibrinogen clotting by the compact colony-forming active substance (CCFAS) (Ohtomo and Yoshida 1981;Usui et al 1982).…”