TABLE 7.

Mean and median time to microbial detection for volume-compliant bottle sets by Virtuo and BTA3D and mean bottle fill volumes for clinically significant isolates recovered from both study bottles in each pair^a

Organism group	n	Mean TTD (h)		P valueb	Median TTD (h)		P valuec	Mean fill, ml
		Virtuo	3D		Virtuo	BTA3D		Virtuo	BTA3D
Coagulase-negative staphylococci	14	20.6	21.4	0.678	19.4	20.8	0.078	4.1	3.9
Enteric Gram-negative bacilli	43	11.1	14.7	<0.001	8.6	11.0	<0.001	4.7	4.6
Enterococcus spp.	18	10.6	12.9	<0.001	11.4	13.4	<0.001	4.3	4.4
Staphylococcus aureus	30	20.8	20.5	0.819	16.1	19.2	0.580	4.7	4.6
Streptococcus spp.	9	11.7	14.5	0.221	8.6	10.4	0.098	2.3	2.6
Yeast	4	26.7	26.4	0.936	26.5	27.7	0.875	4.8	5.0
Other	1	93.6	96.0	NA	93.6	96.0	1.000	0.8	1.0
All	119	15.9	17.7	0.001	12.2	13.4	<0.001	4.4	4.3

^aResults shown are for bottle sets where clinically significant, monomicrobial isolates were recovered from both bottles. Six outliers with a difference in time to microbial detection (TTD) of ≥24 h, suggestive of greatly different organism loads at the time of bottle inoculation, were excluded from this analysis.

^bData represent TTD means. A t test was used to evaluate the mean of the differences.

^cData represent TTD medians. A signed-rank test was used to evaluate the median of the differences in TTD since the TTD data were not normally distributed.