Figure 4

Biofilm formation of Streptococcus uberis strains FSL Z1-048 and FSL Z1-124. Biofilm formation was tested in RPMI-1640 CDM medium supplemented with 0.5% wt/vol casein. Strain 20539 was included as positive control (+ve). Bars represent the sample-to-positive (S/P) ratio after 24 h of culture and standard deviations. S/P = (average sample OD − average negative control OD)/(average positive control OD − average negative control OD), where OD = optical density. The assay was conducted on 3 cultures of each strain and for each assay the result was based on the average of 8 wells. Statistically significant difference between the two strains is marked with asterisk (Mann–Whitney test, *p < 0.05).