TABLE 1.

Identification of Gram-negative organisms in monomicrobial cultures using BC-GN assay

Target	Specimen type	No. with resulta:				Total no.	% (95% CI) forb:
		TP	FP	TN	FN		PPA	NPA
E. colic	Fresh	322d	4	377	0	703	100.0 (98–100)	99.0 (97–100)
	Frozen	304	2	456	0	762	100.0 (98–100)	99.6 (98–100)
	Simulated	49	0	285	0	334	100.0 (91–100)	100.0 (98–100)
	Total	675	6	1,118	0	1,799	100.0 (99–100)	99.5 (99–100)
K. pneumoniae	Fresh	103	0	588	12	703	89.6 (82–94)	100.0 (99–100)
	Frozen	103	1	645	13	762	88.8 (81–94)	99.8 (99–100)
	Simulated	133	0	200	1	334	99.3 (95–100)	100.0 (98–100)
	Total	339	1	1,433	26	1,799	92.9 (90–95)	99.9 (99–100)
K oxytoca	Fresh	21	6	675	1	703	95.5 (75–100)	99.1 (98–100)
	Frozen	38	1	722	1	762	97.4 (85–100)	99.9 (99–100)
	Simulated	4	0	329	1	334	80.0 (30–99)	100.0 (99–100)
	Total	63	7	1,726	3	1,799	95.5 (86–99)	99.6 (99–100)
Enterobacter spp.	Fresh	49	0	654	0	703	100.0 (91–100)	100.0 (99–100)
	Frozen	61	6	694	1	762	98.4 (90–100)	99.1 (98–100)
	Simulated	34	0	300	0	334	100.0 (87–100)	100.0 (98–100)
	Total	144	6	1,918	1	1,799	99.3 (96–100)	99.7 (99–100)
P. aeruginosa	Fresh	84	0	619	0	703	100.0 (95–100)	100.0 (99–100)
	Frozen	51	1	708	2	762	96.2 (86–99)	99.9 (99–100)
	Simulated	41	0	293	0	334	100.0 (89–100)	100.0 (98–100)
	Total	176	1	1,620	2	1,799	98.9 (96–100)	99.9 (99–100)
Proteus spp.	Fresh	25	0	678	0	703	100.0 (83–100)	100.0 (99–100)
	Frozen	47	2	713	0	762	100.0 (91–100)	99.7 (99–100)
	Simulated	3	0	331	0	334	100.0 (31–100)	100.0 (97–100)
	Total	75	2	1,722	0	1,799	100.0 (94–100)	99.9 (99–100)
Acinetobacter spp.	Fresh	13	0	690	0	703	100.0 (72–100)	100.0 (99–100)
	Frozen	19	2	740	1	762	95.0 (73–100)	99.7 (99–100)
	Simulated	28	0	306	0	334	100.0 (85–100)	100.0 (98–100)
	Total	60	2	1,736	1	1,799	98.4 (90–100)	99.9 (99–100)
Citrobacter spp.	Fresh	8	1	694	0	703	100.0 (60–100)	99.9 (99–100)
	Frozen	18	0	744	0	762	100.0 (78–100)	100.0 (99–100)
	Simulated	32	0	312	0	344	100.0 (87–100)	100.0 (98–100)
	Total	58	1	1,750	0	1,799	100.0 (92–100)	99.9 (99–100)

^aTP, true positive, FP, false positive, TN, true negative, FN, false negative.

^bPPA, positive percent agreement; NPA, negative percent agreement; 95% CI, 95% confidence interval.

^cIncludes Shigella spp., which cannot be differentiated by the BC-GN assay.

^dOne of 322 was identified as Shigella sp. by culture.