Serological tests on L-phase variants of some bacteria.

Abstract

Indirect haemagglutination (IHA), metabolism inhibition (MI) and growth inhibition (GI) techniques were used to test streptococcal, staphylococcal and proteusl-phase variants against antisera prepared in rabbits. All three methods were specific and high titres of antibody were measured by the IHA and MI techniques. In tests on the streptococcal variant, IHA measured antibodies which reacted with both surface and internal components while MI measured antibody directed against surface antigens. Guinea-pig serum did not appreciably enhance the MI titre, its main effect being to depress growth of the organisms. The variants reacted with antisera to the parent bacteria in IHA and MI tests, but the titres were 16-to 32-fold lower than when antisera to the variants were used. The possibility that these methods might help to determine whether chronic bacterial infections are perpetuated by organisms in theirl-phase is discussed.