Polysaccharide vaccine for
The invention relates to compositions of the capsular polysaccharide/adhesin (PS/A) of staphylococci . The PS/A may be isolated or synthesized and includes various modifications to the structure of native PS/A based on the chemical characterization of PS/A. The invention also relates to the use of the PS/A as a vaccine for inducing active immunity to infections caused by Staphylococcus aureus, S. epidermidis , other related coagulase-negative staphylococci and organisms carrying the ica (intracellular adhesin) locus, and to the use of antibodies directed to PS/A for inducing passive immunity to the same class of infections.
1. An isolated pure staphylococcal capsular polysaccharide/adhesin antigen (PS/A) having a molecular weight of greater than 100,000 daltons wherein the staphylococcal PS/A is prepared according to a process comprising:
preparing an impure PS/A from a staphylococcal culture;
incubating the impure PS/A from said staphylococcal culture with a strong base or a strong acid to produce a semi-pure PS/A preparation;
neutralizing the semi-pure PS/A preparation with an acid or base;
precipitating the neutralized semi-pure PS/A preparation with an alcohol followed by molecular sieve chromatography and digestion with a proteinase;
incubation of the proteinase-digested PS/A preparation with a base followed by neutralization with an acid;
incubation of the neutralized proteinase-digested PS/A preparation with hydrofluoric acid followed by neutralization with NaOH and precipitation with an alcohol to produce the isolated pure PS/A, wherein the isolated pure PS/A is greater than 92% free of contaminants and contains less than 10% galactose.
2. The isolated pure PS/A of claim 1 , wherein the PS/A has glucosamine residues and wherein at least 50% of the glucosamine residues are substituted with acetate.
3. The isolated pure PS/A of claim 1 , wherein the PS/A has glucosamine residues and wherein at least 50% and 95% of the glucosamine residues are substituted with acetate.
4. The isolated pure PS/A of claim 1 , wherein the impure PS/A is incubated with said strong acid and neutralized with said base.
5. The isolated pure PS/A of claim 1 , wherein the isolated pure PS/A is further precipitated with an alcohol.
6. The isolated pure PS/A of claim 5 , wherein the alcohol is methanol or ethanol.
7. The isolated pure PS/A of claim 1 , wherein the PS/A has less than 5% galactose.
8. The isolated pure PS/A of claim 1 , wherein the PS/A has less than 1% galactose.
9. A pharmaceutical composition comprising the isolated pure PS/A of claim 1 , and a pharmaceutically-acceptable carrier.
10. A pharmaceutical composition comprising the isolated pure PS/A of claim 2 , and a pharmaceutically-acceptable carrier.
11. A pharmaceutical composition comprising the isolated pure PS/A of claim 3 , and a pharmaceutically-acceptable carrier.