Figure 1.

Enhanced biofilm formation by rMIF. A) Biofilms of P.aeruginosa lab strain PA01 grown for 24 h, with or without 100 ng/ml rMIF, were measured by resazurin assay. Significant increase in biofilm formation was seen in biofilms formed in presence of rMIF (100 ng/ml). Data are presented from a series of n = 5 experiments. Wilcoxon matched pairs test was used to analyze data. ***P < 0.001. B) Biofilms of P. aeruginosa lab strain PA14 grown for 24 h, with or without 100 ng/ml rMIF, were measured by resazurin assay. Significant increase in biofilm formation was seen in PA14 biofilms formed in presence of rMIF (100 ng/ml). Data are presented as means ± sem fluorescence signals (FU) (n = 8). A paired Student’s t test was used to analyze data. *P < 0.05. C) Biofilms of clinical isolate CI58112 were grown for 24 h, with or without 100 ng/ml rMIF, and were measured by resazurin assay. Significant increase in biofilm formation was seen when biofilms were formed in presence of rMIF (100 ng/ml). Data are presented as means ± sem fluorescence signals (FU) (n = 8). A paired Student’s t test was used to analyze data. ***P < 0.001 (D, E). Air–liquid interface biofilms or pellicles were allowed to form with or without rMIF (100 ng/ml), stained with CV, washed thoroughly, and imaged. D) Representative images of CV-stained pellicles with or without 100 ng/ml rMIF. Bound CV was released and absorbance measured at 590 nm. E) Significant increase in biofilms grown with rMIF (100 ng/ml) was observed. Data are presented as means ± sem absorbance units (590 nm) (n = 8). Wilcoxon matched pairs test was used to analyze data. **P < 0.01.