TABLE 2.

Colistin MIC frequency distribution tested against a diverse sample of bacterial species

Organism (no. of isolates tested)	No. of isolates (%) inhibited at MIC (μg/ml) of:
	≤1	2	4	8	16	32	64	≥128
Acinetobacter spp. (60)	54 (90.0)	3 (95.0)	1 (96.7)	1 (98.3)		1 (100.0)
B. cepacia (12)								12 (100.0)
Enterobacter spp. (5)	4 (80.0)a						1 (100.0)b
Indole-positive group (4)	2 (50.0)c							2 (100.0)d
K. pneumoniae (9)	8 (88.9)	1 (100.0)
Proteus mirabilis (2)						1 (50.0)		1 (100.0)
P. aeruginosa (80)	79 (98.8)	1 (100.0)
S. marcescens (5)								5 (100.0)
S. maltophilia (23)	13 (56.5)	3 (69.6)	1 (73.9)	1 (78.3)	2 (87.0)	2 (95.7)	1 (100.0)
All strains (200)	160 (80.0)	8 (84.0)	2 (85.0)	2 (86.0)	2 (87.0)	4 (89.0)	2 (90.0)	20 (100.0)

^aE. aerogenes (four strains) 

^bE. cloacae (one strain). 

^cM. morganii (two strains) 

^dP. rettgeri (two strains).