TABLE 4.

Distribution and structure of distinct groups of Tn1546-like elements in environmental VRE

Group	Species (PFGE subtypes)	Source of isolation	Tn1546 PCR-RFLPa		vanX RFLPb	PCR of polymorphic regionsa
			L-PCR	RFLP pattern		ORF1 11c	ORF1 21c	VanSH	VanYZ	VanZ
1a	E. faecium (A)	Vancomycin sludge, sewage	+	1	T	+	+	+	+	+
1b	E. faecium (M, N), E. faecalis (J, L), E. casseliflavus (I5, K), E. durans (untypeable)	Vancomycin effluent, sewage, soil	+	1	G	+	+	+	+	+
2a	E. faecium (B)	Vancomycin sludge, sewage	+	1	T	−	+	+	+	+
2b	E. faecium (F), E. mundtii (E), E. casseliflavus (I3), E. durans (H)	Polymyxin effluent, sewage	+	1	G	−	+	+	+	+
3	E. casseliflavus (I2)	Vancomycin effluent	+	2	G	−	+	+	+	+
4	E. casseliflavus (I4)	Sewage	12,000	3	G	−	+	+	2,500	+
5	E. faecium (C), E. mundtii (D)	Blue mussels, vancomycin sludge, vancomycin effluent	−		T	−	+	+	+	+
6	E. mundtii (not typeable)	Sewage, soil	−		T	+	+	+	+	+
7	E. faecium (G)	Polymyxin effluent	−		T	−	−	+	+	+

^a+, presence of a PCR product of the expected size in Tn1546; −, no PCR product was detected. The detection of PCR products of other sizes than expected is indicated by the approximate size (bp) of these products.

^bDetection of the point mutation G→T in vanX at position 8,234.

^cDesignations are according to Simonsen et al. (21): ORF1 11, proximal ORF1 region (base positions 164 to 901 in the sequence of Tn1546 (GenBank accession no. M97297); ORF1 21, distal ORF1 region (positions 949 to 2,952).