TABLE 3.

Range of VBSs tested to determine optimum matching tolerance for E. faecium isolates

Parameter	Result at VBS of:
	0.125	0.500	0.750	0.925a	1.250
Match similarity percentage defining dendrogram group	7	44	66	74	73
Within dendrogram group
Total no. of isolatesb	59	55	37	31	43
No. of VSG isolatesc	26	26	26	26	26
No. of dissimilar isolates (non-VSG)	33	29	11	5	17
% Sensitivityc	100	100	100	100	100
% Specificityd	6	17	31	86	49

^aOptimum VBS setting for E. faecium PFGE library.

^bExcludes reference E. faecium isolate.

^cBy definition, the dendrogram group included all VSG isolates.

^dSpecificity = [true negatives/(false positives + true negatives) × 100], where true negatives are non-VSG isolates located outside of the dendrogram group.