Enclosure of bacteria within capillary multifilament sutures as protection against leukocytes.

The effect of leukocyte against Staphylococcus aureus in the presence of capillary multifilament suture materials was observed in an in vitro phagocytosis test. The leukocytes had a phagocytic effect against bacteria in the culture medium but not against bacteria in the suture threads. The bacteria enclosed in the interstices of the suture threads could multiply there, and 'leakage' of bacteria from the thread to the surrounding medium maintained a high bacterial presence despite the phagocytic activity of leukocytes in the medium. Adherence of leukocytes to suture materials was studied in experiments with 51Cr-labeled leukocytes. There was no significant leukocyte penetration into the two capillary multifilament suture materials in the tests. Bacteria enclosed in the interstices of capillary multifilament suture threads appear to be protected from the phagocytic action of leukocytes and thus can support and prolong the course of an infection.