Fig 1. Growth competition of L. monocytogenes strains.

L. monocytogenes strains (A) PL25-Rif^R, (B) C5-Str^R, (C) ScottA-Str^R/Rif^R and (D) 6179-Rif^R were grown alone (single) and in the presence of a second L. monocytogenes strain in TSB-Y for 10 days at 10°C. Cultures were sampled on day 0, 1, 3, 5, 7 and 10; and CFUs were determined by plating serial dilutions on TSA-Y and TSA-Y supplemented with rifampicin or streptomycin. Data represented as log (CFU/ml) are mean values ± standard deviation of three biological replicates performed in duplicate. *indicate statistically significant differences between the co-culture and the corresponding single culture (P<0.05).