Studies on T H E Pathogenesis of Staphylococcal I N F E C T I O N * Ii. Tae Ei~fect of Non-specific Infl/~ration

In the preceding paper it was shown that large numbers of pathogenic staphylococci must be injected intradermally into normal rabbits to induce a local skin infection (1). The apparent low infectivity of staphylococci in normal rabbit skin is similar to that observed by Elek (2) in human beings. Elek, however, demonstrated an increase in infectivity in the skin of volunteers when the microorganisms were inoculated with a foreign body such as a silk suture. In naturally occurring staphylococcus disease of man it is usual to observe infection in areas of tissue injury. For example, the most frequent site of infection is in skin wounds or abrasions and in obstructed hair follicles. This suggests that inflammation may play a role in altering the susceptibility of skin and other tissues to infection by the staphylococcus. That non-specific inflammation may significantly influence the evolution of an infection has been demonstrated many times (3-13), although the age of the inflammation and the nature of the bacterium probably play important roles in determining whether or not the inflammation increases or decreases the microorganisms' infectivity. Established inflammation, for example, has been shown to increase local resistance to the streptococcus, Bacillus pyocyaneus, and anthrax bacillus (6, 9, 12, 13). On the other hand established inflammation has been shown to enhance the infectivity of Treponema paUidum and fowl cholera bacillus (8, 9).