Fig 1. Y. pestis strains with multiple plasmid-encoded copies of rovM show differential ability to form biofilm in varying nutritional conditions.

Biofilm formation of Y. pestis KIM6+ strains in LB medium supplemented with 4mM MgCl₂ and 4mM CaCl₂ (A) and TMH-gal⁺ medium (B). Error bars are the mean±SD of four independent biological replicates. A One Way ANOVA combined with a Tukey’s test was used to test significant differences in the biofilm formation between strains. The overall P-value for the ANOVA was P<0.0001. *** represents P<0.001 and indicates a significant difference in biofilm formed between the strains. Horizontal lines mark a groups of bars that are being compared.