Evaluating Antimicrobial Activity Against Salmonella

The inhibitory activity of MccJ25, reuterin and rifampicin against Salmonella Newport in the PolyFermS model was evaluated using the quantitative polymerase chain reactions (PCR) for the amplification of 16S rDNA that was performed in MicroAmp^® Fast Optical 96-Well Reaction Plates with Barcode (Life Technologies Inc., Burlington, ON, Canada) on an ABI 7500 Real-Time PCR System (Applied Biosystems, Streetsville, ON, Canada). Each sample was analyzed in duplicate. Salmonella Newport growth was quantified using the amplification primers invAF (5′-CGTTTCCTGCGGTACTGTTAATT-3′) and invAR (5′-TCGCCAATAACGAATTGCCCGAAC-3′) (Li and Chen, 2013 (link)). Extracted DNA was diluted 1/10 (v/v) in DNase-free water (Invitrogen) and placed in the microplate wells (5 μL of diluted extract per well). Each well also contained 12.5 μL of Fast SYBR^® Green Master Mix (Applied Biosystems, Burlington, ON, Canada), 1 μL of each primer, forward and reverse, at a final concentration of 5 μM (Sigma-Aldrich, St. Louis, MO, United States) and 5.5 μL of DNase-free water.