A STUDY OF THE RELATIONSHIP OF THE NORMAL BACTERICIDAL ACTIVITY OF HUMAN SERUM TO BACTERIAL INFECTION*

Abstract

An investigation of the heat-labile bactericidal properties of undiluted sera from 36 healthy donors and 43 patients with diseases often associated with infection was conducted. Known inocula of a variety of strains of gram-negative enteric bacilli were subjected to the action of undiluted active serum for 2 hr. and subcultures were taken. With the exception of sera from 3 patients, all sera killed any given bacterial strain at nearly equal rates. It was found that a much higher proportion of strains of enteric bacilli isolated from the blood of bacteremic patients were resistant to the bactericidal action of serum than were strains isolated from the stool or urine.