Tryptic soy agar (TSA; Becton, Dickinson
and Company, Sparks, MD) with 100 µg/ml rifampicin (TSAR)
was used to enumerate Salmonella. Resuspended cultures were
serially diluted with 0.1% peptone water and enumerated to verify
the initial concentration. Resuspended cultures contained approximately
108-109 CFU/ml Salmonella.