Polymorphonuclear leucocytes selectively inhibited the incorporation of 14C-uridine by intracellular staphylococci. Within specified limits, the amount of radiolabel incorporated by extracellular staphylococci was related to bacterial concentration. The incorporation of labelled uridine can thus be exploited to assay the extent to which association between staphylococci and polymorphonuclear leucocytes reflects surface adherence as opposed to ingestion. A comparison of the new method with a conventional viable-count determination of leucocyte-associated bacteria shows it to be comparable in efficiency when non-immune serum is used as opsonin and superior when specific opsonin is used.
ColeP.,
BrostoffJ.1975; Intracellular killing of Listeria monocytogenes by activated macrophages (Mackaness system) is due to antibiotic. Nature (Lond.) 256:515
GibbsD. L.,
RobertsR. B.1975; The interaction in vitro between human polymorphonuclear leukocytes and Neisseria gonorrhoeae cultivated in the chick embryo. J. exp. Med 141:155
MichellR. H.,
PancakeS. J.,
NoseworthyJ.,
KarnovskyM. L.1969; Measure-ment of rates of phagocytosis. The use of cellular monolayers. J. cell. Biol 40:216
PattersonR.J.,
YoumansG. P.1970; Multiplication of Mycobacterium tuberculosis within normal and “immune” mouse macrophages cultivated with and without streptomycin. Infect. Immun 1:30
SwansonJ.,
SparksE.,
ZeligsB.,
SiamM. A.,
ParrottC.1974; Studies on gonococcus infection. V. Observations on in vitro interactions on gonococci and human neutrophils. Infect. Immun 10:633
TanJ. S.,
WatanakunakornC.,
PhairJ. P.1971; A modified assay of neutrophil function: use of lysostaphin to differentiate defective phagocytosis from impaired intracellular killing. J. lab. clin. Med 78:316
VealeD. R.,
FinchH.,
SmithH.,
WittK.1976; Penetration of penicillin into human phagocytes containing Neisseria gonorrhoeae: Intracellular survival and growth at optimum concentrations of antibiotic. J. gen. Microbiol 95:353
VerhoeffJ.,
PetersonP. K.,
QuieP. G.1977; Kinetics of Staphylococcal opsonization, attachment, ingestion and killing by human polymorphonuclear leukocytes: a quantitative assay using [3H]thymidine labelled bacteria. J. immun. Meth 14:303
YamamuraM.,
ValdimarssonH.1978; A new semiquantitative radiometric opsonin assay. Selective measurement of opsonizing capacity of the alternative pathway. Immunology 34:689