4.9. Examination of B. cereus Strain 003 Spores for Plasmid

Dormant spores carrying pHT315-PgerR-gerRB-SGFP2 at OD600 of 2.0 were heated 15 min at 70 °C, in duplicate. The heated spores were diluted 10⁻⁵-fold in TSB medium, 100 μL of diluted spores immediately spread on a TSB agar plate (TSB-agar), and the plates were incubated for 24 h at 30 °C. Following this incubation, 24 single colonies in each replicate were incubated on TSB-agar with 10-μg/mL erythromycin at 30 °C overnight to assess erythromycin resistance plasmid presence was confirmed by colony PCR with the primers 315-F/R.