Colistin

Predictable Activity

Bergeyella zoohelcum
Bordetella pertussis
Citrobacter freundii complex
Escherichia coli
Haemophilus influenzae
Klebsiella oxytoca
Klebsiella pneumoniae
Pseudomonas aeruginosa

Unpredictable Activity

Acinetobacter spp
Aerobic Gram negative bacilli – nonfermenters
Aeromonas spp
Pseudomonas spp (other than P. aeruginosa)
Shigella spp
Stenotrophomonas maltophilia
Vibrio spp

No/Insufficient Activity

Alcaligenes spp
Anaerobes
Bacillus spp
β-hemolytic streptococci (Group A,B,C,G)
Burkholderia spp
Chlamydia spp
Corynebacterium spp
Enterobacter spp
Enterococcus spp
Erysipelothrix rhusiopathiae
Gram positive organisms
Lactobacillus spp
Legionella spp
Listeria monocytogenes
Morganella spp
Mycoplasma spp
Neisseria gonorrhoeae
Neisseria meningitidis
Proteus mirabilis
Proteus vulgaris complex
Providencia spp
Salmonella spp
Serratia spp
Staphylococcus aureus (MSSA , MRSA)
Staphylococcus lugdunensis
Streptococcus pneumoniae
Viridans group Streptococci