Gram positives: +/- Staphylococci (including MRSA), Streptococcus pneumoniae

Gram negatives: +/- Stenotrophomonas maltophilia, +/- Acinetobacter spp., Haemophilus influenzae, Moraxella catharralis

Other: Atypical (intracellular) pathogens, rickettsia, spirochetes, Plasmodium spp. (Malaria)