Abscesses

Abscesses that develop as a result of introduction of the normal endogenous flora into a normally sterile body site are often polymicrobial in nature. These flora can gain access to the sterile site by direct extension or secondary to laceration or perforation. Due to the uniqueness of the normal endogenous flora at the various body sites, the microbiology of such abscesses is generally predictable. This chapter describes the specific microbiology of polymicrobial abscesses that occur at various body sites. It also reviews the data that demonstrate the synergy between the aerobic and anaerobic components of these abscesses, and highlights the role of the bacterial capsule as a virulence factor that enhances the formation of an abscess.