Opsonophagocytosis of bacteria studied by chemiluminescence in microtitre plates

A protocol for polymorphonuclear leukocyte chemiluminescence (PMN CL) assays of opsonophagocytosis was developed for a microtitre-plate luminometer. The complete procedure was performed in a single microtitre plate and was simpler and more efficient than previous protocols. The kinetics of the PMN CL response were best when microtitre plates were incubated on a shaking incubator between readings. The new protocol was used in a study of the pathogenicity of Corynebacterium jeikeium, an organism found in association with infection in the immunocompromised. No differences were found when PMN CL induction by 15 strains of C. jeikeium were compared with 15 isolates of other corynebacteria. Both groups of organisms required complement for efficient opsonophagocytosis; C. jeikeium strains showed no requirement for specific antibody. Resistance to opsonophagocytosis does not appear to be an explanation for the increased pathogenicity of C. jeikeium. Microtitre-plate luminometers are particularly well suited to bacterial opsonization studies where large numbers of strains often need to be assessed.