The accuracy of four commercial broth microdilution tests in the determination of the minimum inhibitory concentration of colistin

Table 1 Essential Agreements of commercial MIC tests compared to reference standard Broth Microdilution, n (%)

Isolates	n	Sensititre™		SensiTest™ colistin		UMIC colistine		Micronaut MIC strip–colistin
Isolates	n	vs. BMD	vs. composite reference	vs. BMD	vs. composite reference	vs. BMD	vs. composite reference	vs. BMD	vs. composite reference
Total	70	61 (87.1)	62 (88.6)	65 (92.8)	63 (90.0)	61 (87.1)^a	62 (88.6)^a	58 (82.9)	59 (84.3)
Enterobacteriales	44	39 (88.6)	38 (86.4)	42 (95.5)	40 (90.9)	41 (93.2)	38 (86.4)	40 (90.9)	38 (86.4)
Escherichia coli	19	19 (100)	19 (100)	19 (100)	18 (94.7)	19 (100)	19 (100)	19 (100)	19 (100)
Klebsiella pneumoniae	14	11 (78.6)	12 (85.7)	13 (92.9)	14 (100)	13 (92.9)	13 (92.9)	12 (85.7)	12 (85.7)
Enterobacter cloacae complex	3	1 (33.3)	3 (100)	3 (100)	3 (100)	3 (100)	2 (66.7)	2 (66.7)	2 (66.7)
Enterobacter spp.	3	3 (100)	1 (33.3)	3 (100)	1 (33.3)	3 (100)	1 (33.3)	2 (66.7)	1 (33.3)
Proteus hauseri	1	1 (100)	1 (100)	0 (0)	1 (100)	1 (100)	0 (0)	1 (100)	0 (0)
Citrobacter freundii	1	1 (100)	1 (100)	1 (100)	1 (100)	0 (0)	1 (100)	1 (100)	1 (100)
Kluyvera georgiana	1	1 (100)	0 (0)	1 (100)	1 (100)	0 (0)	0 (0)	1 (100)	1 (100)
Klebsiella variicola	1	1 (100)	1 (100)	1 (100)	1 (100)	1 (100)	1 (100)	1 (100)	1 (100)
Serratia spp.	1	1 (100)	0 (0)	1 (100)	0 (0)	1 (100)	1 (100)	1 (100)	1 (100)
Non fermentative Gram-negatives	26	22 (84.6)	24 (92.3)	23 (88.5)	23 (88.5)	20 (76.9)	24 (92.3)	18 (69.2)	21 (80.8)
Pseudomonas aeruginosa	23	20 (86.9)	22 (95.7)	20 (87.0)	20 (87.0)	18 (78.6)	22 (95.7)	17 (73.9)	20 (87.0)
Acinetobacter spp.	2	2 (100)	1 (50)	2 (100)	2 (100)	1 (50)^a	1 (50)^a	1 (50)	1 (50)
Achromobacter xylosoxidans	1	0 (0)	1 (100)	1 (100)	1 (100)	1 (100)	1 (100)	0 (0)

ISSN: 1476-0711