Table 1 Primer sequences and PCR conditions for quadruplex phylo-grouping of E. coli

arpA (phylogenetic grouping)

F (5-AACGCTATTCGCCAGCTTGC-3)

R (5-TCTCCCCATACCGTACGCTA-3)

400

PCR reactions were performed in a total volume of 25 µL by ready-to go PCR beads using 20 pmol of each primers for all targets except arpA (40 pmol) and trpA (12 pmol). The cycling conditions were as follow: denaturation 4 min at 94 °C, 30 cycles of 5 s at 94 °C and 20 s at 59 °C, 20 s at 72 °C and a final extension step of 5 min at 72 °C

[24]

chuA (phylogenetic grouping)

F (5-GACGAACCAACGGTCAGGAT-3)

R (5-TGCCGCCAGTACCAAAGACA-3)

288

yjaA (phylogenetic grouping)

F (5-TGAAGTGTCAGGAGACGCTG-3)

R (5-ATGGAGAATGCGTTCCTCAAC-3)

211

TspE4C2 (phylogenetic grouping)

F (5-GAGTAATGTCGGGGCATTCA-3)

R (5-GCGCCAACAAAGTATTACG-3)

152

Internal control trpA

 F (5-CGGCGATAAAGACATCTTCAC-3)

R (5-GCAACGCGGCCTGGCGGAAG-3)

489