Fig. 3
a Serum killing assay of the WT and its TfpNDM-hvKP strains. Data are mean ± SEM for n = 3. To normalize data, log10-transformed values were utilized, the area under each curve was calculated and compared using two-tailed unpaired t tests. (P > 0.05). SEM, standard error of the mean. b Analysis of biofilm formation by WT and its TfpNDM-hvKP strains. Overnight cultures of K. pneumoniae strains were grown in fresh Luria-Bertani (LB) broth at a ratio of 1:100 in polystyrene plates at 37 °C for 5 h. The bacteria were stained with crystal violet, washed to remove unbound cells, eluted with 95% ethanol, and biofilm masses were detected by measuring the absorbance at 600 nm. P < 0.05 versus the TfpNDM-hvKP strain. Error bars indicate the standard deviations for three triplicate samples