Bacterial Strains, Plasmids, and Growth Conditions

The bacterial strains and plasmids used in this study are listed in Table 1. Primers are listed in Supplementary Table S1. Unless otherwise stated, K. pneumoniae and E. coli were routinely cultured in Luria-Bertani (LB) medium (10 g/L tryptone, 5 g/L yeast extract, and 10 g/L NaCl) supplemented with appropriated antibiotics at the following concentrations: kanamycin (50 μg/mL), ampicillin (100 μg/mL), chloramphenicol (100 μg/mL), and gentamicin (20 μg/mL) on the rotatory shaker at 37°C and 200 rpm. For observation of lac operon activity, 2 μL of diluted overnight cultured bacterial solution was inoculated on MacConkey plate without/with 1 mM cAMP and LB agar plate containing 50 μg/mL of 5-bromo-4-chloro-3-indolyl-β-galactopyranoside (X-gal). Overnight cultured bacteria were diluted 1000-fold into the M9 minimal medium supplemented with 1% lactose and incubated for 24–48 h. The two clinical isolates of K. pneumoniae from bacterial storage bank in Tzu Chi Hospital to College of Medicine at Tzu Chi University was through official transfer.

Bacterial strains and plasmids used in this study.