No abstract

A property of mycoplasmas (PPLO) is the inhibition of their growth by specific antibody. Edward & Fitzgerald (1954) Jensen (1964). This is based upon the inhibition of reduction of tetrazolium. Unfortunately, this technique does not have wide application since M. pneumoniae is unique among the mycoplasma species that infect man in its ability to reduce readily tetrazolium salts. However, the growth of M. pneumoniae and certain other mycoplasma species is accompanied by the production of acid, and the incorporation of phenol red into the medium permits the resultant pH change to be seen. The addition of specific antiserum to the medium inhibits mycoplasma growth and this inhibition can be visualized by failure of the indicator to change colour. This communication describes the development of this technique for the quantitative measurement of growth-inhibiting antibody to the acidproducing mycoplasmas and indicates its practical significance.