FIGURE 2.

(A) Detection of biofilm formed by ATCC43816, ΔqseB, ΔqseC and ΔqseBC. Image of biofilm stained with 1% CV and adhered on plastic centrifuge tubes. (B) Biofilm were stained with 1% CV and washed with sterile water. The extracted color was dissolved with 33% glacial acetic acid and measured at OD₅₉₅. Asterisks (****) represent statistically significant differences in biofilm formation between ATCC43816 and its qseCmutant (P < 0.0001, t test). (C) Image of biofilm formed by ATCC43816-pBAD24, ΔqseC-pBAD24 and the complement strain ΔqseC-pCqseC. Biofilm were stained with 1% CV, washed with sterile water and then dissolved with 33% glacial acetic acid. (D) The extracted color was measured at OD₅₉₅ to show biofilm production. Asterisks (****) represent statistically significant differences in biofilm formation between ATCC43816-pBAD24 and ΔqseC-pBAD24/ΔqseC-pCqseC (P < 0.0001, t test). The biofilm formation of ΔqseC-pCqseC was significantly lower compared with that of ΔqseC-pBAD24 (P = 0.0366, t test).