Observations on the Action of Human and Animal Blood on the Meningococcus

Abstract

It is the purpose of this report to record the results of some further studies on the bactericidal effect of samples of blood, from humans and animals, on the meningococcus. The observations reported previously by Silverthorne and Fraser (1) have been extended. The present investigations deal principally with the specificity of this reaction. Technic. In that communication (1) the technic of the bactericidal test was reported and a modification of the original technic was outlined. Essentially this modification consists in the use of smaller volumes, both of citrated blood (0.2 cc.) and of suspended meningococci (0.01 cc.); the initial (undiluted) suspension being made up in 5 cc. of broth in place of 2 cc. This modified technic was used in the following experiments. Experimental. Tests were set up in order to determine the bactericidal effects of certain constituents of blood. Samples of human blood, known to be bactericidal and others possessing relatively little bactericidal action were tested.