TABLE 2.

Time to detection in four different types of blood culture bottles incubated in two blood culture systems

Species/group	No. of isolates	Time to positivity (median, h)								P valuea
		FA		FA Plus		FN		FN Plus
		3D	Virtuo	3D	Virtuo	3D	Virtuo	3D	Virtuo
Gram-negative species	38	14.5	11.4	14.0	11.4	13.2	10.7	14.5	11.7	<0.0001
Escherichia coli	10	14.7	11.4	11.5	9.2	13.1	10.1	11.4	8.8	<0.0001
Klebsiella spp.	10	12.6	9.8	14.0	11.9	12.1	9.7	15.0	12.1	<0.0001
Serratia marcescens	12	15.3	11.9	15.5	12.0	14.5	11.5	15.5	12.5	<0.0001
Acinetobacter spp.	6	16.5	14.0	14.0	12					<0.0001
Gram-positive species	43–48	16.3	13.3	13.0	11	16.8	13.7	14.0	11.0	<0.0001
Staphylococcus aureus	10	16.6	13.8	13.1	11.3	18.7	14.3	13	10.9	<0.0001
CoNS	2–5	21.8	16.0	19.6	15.5	33.5	30.0	19.6	17.7	<0.0001
Enterococcus spp.	10	16.0	12.9	13.0	10.5	15.0	11.8	13.5	10.1	<0.0001
Beta-hemolytic streptococci	5	21.0	14.0	12.0	10.0	17.0	13.8	14.0	12.1	<0.0001
Streptococcus pneumoniae	13	15.0	11.0	13.0	10.3	16.0	13.0	14.0	11.0	<0.0001
Alpha-hemolytic streptococci	3–5	21.0	15.0	17.9	14.6	18.9	14.1	19.4	13.6	<0.0001
Yeast	27	50	39	56	48					<0.0001
Candida albicans	12	23.9	20.8	26.5	24.4					<0.05
Candida glabrata	15	79.2	68.0	65.0	54.0					<0.0001
Total	108–113	16.6	13.3	14.0	12.0	15.0	12.0	14.0	11.1	<0.0001

^aComparison of BacT/Alert 3D and BacT/Alert Virtuo using 2-way matched ANOVA.