Table 2.

Primers used in qPCR.

Name	Sequence	Targeted gene	Product size (bp)	Referencec
331F	5′-TCCTACGGGAGGCAGCAGT-3′	16S rRNA	197 bp	Muyzer et al., 1993; Nadkarni et al., 2002
518R	5′-ATTACCGCGGCTGCTGG-3′
intI1-LC1	5′-GCCTTGATGTTACCCGAGAG-3′	intI1 (class 1 integrons)	196 bp	Barraud et al., 2010
intI1-LC5	5′-GATCGGTCGAATGCGTGT-3′
trfA2-1	5′-CGAAATTCRTRTGGGAGAAGTA-3′	trfA (IncP-1 plasmids)	241 bp	Götz et al., 1996
trfA2-2	5′-CGYTTGCAATGCACCAGGTC-3′