EXPERIMENTAL STAPHYLOCOCCUS INFECTION IN THE HAMSTER CHEEK POUCH: THE PROCESS OF LOCALIZATION

Small amounts of staphylococcus suspensions were injected into the cheek pouches of hamsters. Within 5 hours, the organisms were recovered from all outlying areas of the pouches, and in the following hours the entire structures showed vasodilation, edema, petechiae, and accumulation of leukocytes in the venules. Leukocytosis also occurred at this time. Between 24 and 48 hours, well defined abscesses developed at the sites of injection, and there was a sharp decrease in the bacteria in all other areas. From the 3rd day onward, organisms were only occasionally recovered from tissue outside the abscesses. At this period of localization, the generalized edema and petechiae also subsided, as did the leukocytosis. Localization of infection was not due to a walling off process, since the bacteria were disseminated through the entire pouches in the 1st few hours, but these organisms diminished rapidly, while those at the original injection sites continued to grow and reproduce for several days. Localization of infection appeared to be due to the inability of the bacteria carried away from the site of injection to reproduce. This in turn may have been due to dilution, to lack of sufficient toxin to produce a necrotic substrate, or to greater accessibility of these organisms to phagocytes.