PHOSPHORYLCHOLINE-CONTAINING ANTIGENS IN BACTERIA FROM THE MOUTH AND RESPIRATORY-TRACT

Phosphorylcholine (PC)-containing antigens were sought in 269 bacteria l isolates from the mouth and respiratory tract by an enzyme immunoass ay method, Only 41 (15%) isolates were PC-positive and of these 29 (70 %) were strains of Haemophilus influenzae, Other species that produced positive results included two of five isolates of Gemella haemolysans , two of five isolates of Micrococcus spp., and a single strain each o f Bacillus sp., Corynebacterium jeikeium, Lactococcus sp, and H. parai nfluenzae. The presence of PC-containing antigens in H. influenzae may be an important source of cross-reaction in antigen detection techniq ues that detect the C-polysaccharide antigen of Streptococcus pneumoni ae in respiratory specimens and would result in false positive results .