Prodigiosin inhibits motility and activates bacterial cell death revealing molecular biomarkers of programmed cell death

The antimicrobial activity of prodigiosin from Serratia nematodiphila darsh1, a bacterial pigment was tested against
few food borne bacterial pathogens Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia
coli. The mode of action of prodigiosin was studied. Prodigiosin induced bactericidal activity indicating a stereotypical
set of biochemical and morphological feature of Programmed cell death (PCD). PCD involves DNA fragmentation,
generation of ROS, and expression of a protein with caspase-like substrate specificity in bacterial cells. Prodigiosin was
observed to be internalized into bacterial cells and was localized predominantly in the membrane and the nuclear
fraction, thus, facilitating intracellular trafficking and then binding of prodigiosin to the bacterial DNA. Corresponding
to an increasing concentration of prodigiosin, the level of certain proteases were observed to increase in bacteria
studied, thus initiating the onset of PCD. Prodigiosin at a sub-inhibitory concentration inhibits motility of pathogens.
Our observations indicated that prodigiosin could be a promising antibacterial agent and could be used in the prevention
of bacterial infections.