EFFECT OF SURFACTANT ON NITROBLUE TETRAZOLIUM REDUCTION OF POLYMORPHONUCLEAR LEUKOCYTES STIMULATED WITH TYPE IA GROUP-B STREPTOCOCCI

Activation of polymorphonuclear leucocytes (PMN) was investigated afte r incubation of adult human PMN and group B streptococci (GBS) type Ia with a type-specific polyclonal antiserum and a modified porcine surf actant (Curosurf). The level of oxidative metabolism of PMN was studie d using a micromethod modification of the nitroblue tetrazolium (NBT) reduction test. GBS alone did not stimulate significant oxygen metabol ite release from PMN, and incubation of PMN with surfactant alone resu lted in decreased NBT reduction. After opsonization of GBS with a spec ific antibody, PMN were activated and the increased oxygen metabolite release was not suppressed when surfactant was added to the system. We conclude that the encapsulated GBS strain investigated needs opsoniza tion with specific antibody to increase oxidative metabolism of PMN, a nd that incubation of PMN and opsonized GBS with surfactant does not i nterfere with NBT reduction.