A method for demonstrating growth-inhibitory and bactericidal action on the pneumococcus of a normal serumleucocyte mixture

Abstract

Methods heretofore employed in testing for growth inhibiting and bactericidal action of the blood on pneumococcus have consisted in suspending small numbers of pneumococci in whole blood, serum or serum-leucocyte mixtures, contained in the capillary pipette, test tube or hanging drop. Results of tests on serum and serum-leucocyte mixtures have shown a general agreement that neither serum nor serum and leucocytes together inhibit the growth of the pneumococcus. Studies on whole blood, however, have resulted in most divergent findings. Certain workers (Wright, Heist and Solis Cohen) report the finding not only of growth inhibition, but also of pneumococcidal activity in the blood of animals resistant to pneumococcus infection. Other investigators, (Barber, Bull and Bartual) using the same methods on the blood of the same and other resistant animal species failed to find anything more than growth retardation. A review of the more important literature on this subject leads one to the conclusion that with the ...