STREPTOCOCCUS-PNEUMONIAE PRODUCES A 2ND HEMOLYSIN THAT IS DISTINCT FROM PNEUMOLYSIN

Pneumococci are described as alpha-haemolytic but under certain circum stances they produce zones of beta-haemolysis on blood-containing medi um. This observation was investigated using wild type strains and a ge netically-modified strain unable to produce the haemolytic toxin, pneu molysin. beta-haemolysis was produced by all pneumococci tested. It wa s-not inhibited by anti-pneumolysin antibody but could be inactivated by cholesterol. These data confirm that pneumococci elaborate a second haemolysin, distinct from pneumolysin. (C) 1997 Academic Press Limite d.