Investigation of self-assembly and topological changes in the sessile droplets of Klebsiella oxytoca by Chronological study

The infectious droplet from the patient self-assembles into a novel pattern depending on bacterial interaction with substrate and liquid. The spatial location of bacteria inside the droplet fluctuates depending on the non-covalent forces. The deformation and dehydration induced stress on bacteria in evaporating contagious-fluid droplets alters the viability and infectivity. The self-assembly of Klebsiella oxytoca (KO) in contagious sessile droplets was studied by natural evaporation. KO forms novel patterns as the droplets exsiccate, thus revealing the unexplored topological changes that govern its survival and infection strategies. The droplets of both bacterial suspension in Milli-Q and SRF of volume 0.95 ± 0.1 μl were placed on the glass material for assessment of the self-assembly. The bacterial suspension was stained before allowing them to desicate. The bacterial chemotaxis and deposition near the end of evaporation are recorded using the bright and dark field optical method. The random time interval is also measured to track the bacterial movement. The investigation shows that the majority of the bacterial population moves toward the rim of the droplet because of edge closely packing, leading to enhanced viability and pathogenesis on the famously known “coffee ring” and few bacteria are present at the centre of the droplet which represents chemotaxis of bacteria. The mechanistic insight gained via our study can have far-reaching implications for bacterial infection through droplets e.g., through open wounds.