Fig. 2.

Touchdown PCR demonstrating increased ETBF detection when ETBF-spiked samples are pre-incubated in Peptone Yeast Glucose with Bile (PYGB) broth for 2 days prior to PCR analysis. a In this representative experiment, the detection limit without broth amplification is 3.55 × 10⁴ CFU/g stool. b The assay sensitivity is increased to 3.55 × 10² CFU/g after samples have been incubated for 2 days in PYGB broth, which promotes growth of Bacteroides spp. “+” indicates the positive control lane, which contains an ETBF culture spiked into mouse stool (10⁹ CFU/g). The spiked positive control is also pre-incubated for 2 days in PYGB broth. The numbered lanes refer to the log value in ETBF CFU/g spiked into mouse stool (see also the caption for Fig. 1). The underlined numbers demonstrate the last sample where a band can be detected