Modulating production of pneumococcal capsular polysaccharide

In a method of producing capsular polysaccharide from a pneumococcus by maintaining the pneumococcus in a growth medium, the improvement comprising maintaining a gas having a super-atmospheric concentration of carbon dioxide in contact with the growth medium.

A method of alleviating a pneumococcal infection in an animal, the method comprising maintaining the animal in contact with a gas having a super-atmospheric concentration of oxygen.

A method of making an immunogenic preparation for administration to an animal at risk for developing a pneumococcal infection, the method comprising

• maintaining pneumococcal cells in a growth medium having an oxygen content lower than the same medium equilibrated at the same temperature with normal air;
• and
• isolating capsular polysaccharide produced by the cells from the cells, whereby the isolated polysaccharide constitutes the immunogenic preparation.

In a method of producing capsular polysaccharide from a pneumococcus by maintaining the pneumococcus in a growth medium, the improvement comprising maintaining the carbon dioxide concentration of the growth medium at a level at least equal to the concentration of carbon dioxide in the same growth medium equilibrated at the same temperature with a gas comprising 5% carbon dioxide.

A method of producing pneumococcal polysaccharide, the method comprising maintaining pneumococcal cells in a growth medium having an oxygen content lower than the same medium equilibrated at the same temperature with normal air.

A method of assessing whether a test compound is useful for alleviating a pneumococcal infection in an animal, the method comprising comparing

• the degree of phosphorylation of CpsD in pneumococcal cells maintained in the presence of the test compound and
• the degree of phosphorylation of CpsD in the same type of cells maintained in the absence of the test compound, wherein if the degree of phosphorylation of CpsD in the cells maintained in the presence of the test compound is less than the degree of phosphorylation of CpsD in the cells maintained in the absence of the test compound, then the test compound is useful for alleviating the infection.