Gram positive: Staphylococci including many MRSA, S. pneumoniae

Gram negative: M. catarrhalis, H. influenzae, Brucella

Anaerobic: Actinomyces, Prevotella, non-difficile Clostridia, Peptostreptococci

Other: Mycoplasma, Chlamydophila; Rickettsia; Borrelia burgdorferi; some mycobacteria