Gram positive

•  Many Streptococcus spp.

•  Enterococcus faecalis

•  Listeria monocytogenes

Gram negative:

• Neisseria meningitidis

• Pasturella multocida

• Some Enterobacteriaceae

Anaerobes

• Actinomyces spp.

• Clostridium spp. (excluding Clostridium difficile)

• Peptostreptococcus spp.

• Propionibacterium acnes