Figure 4

Classification of the blinded panel of strains as susceptible (A), intermediate (B) or resistant (C) based on their relative growth rates on EMB containing medium between day 7–9. *Strain 9 could not be classified between I and R due to missing data due to contamination of the sample exposed to 4 mg/L EMB and is shown in both I and R graphs. The 0 mg/L control of strain 19 was contaminated, therefore pre-exposure growth rate was used as 100% for this strain. When retested (not shown) results for strain 19 were similar.