Influence of temperature on opsonization and phagocytosis of staphylococci

The effect of incubation temperatures of 41, 37, and 4 degrees C on phagocytosis was investigated using human neutrophils and [3H]thymidine-labeled staphylococci. Depressed phagocytosis was observed at 41 and 4 degrees C. At 41 degrees C diminished staphylococcal uptake resulted from decreased attachment of bacteria to leukocytes; the inhibitory effect at 4 degrees C was secondary both to decreased opsonization and to reduced attachment to leukocytes. In contrast to the findings with normal serum, opsonization with heat-inactivated serum appeared to be relatively intact at 4 degrees C. By incubating samples in lysostaphin, it was determined that the process of bacterial ingestion as well as that of attachment was adversely affected by incubation temperatures of 41 and 4 degrees C.