MOTILITY OF Escherichia coli: TRANSITION FORM SWIMMING TO SWARMING

G. FIER; D. HANSMANN; R.C BUCETA

Cordoba

Congreso; XI CONGRESO ARGENTINO DE MICROBIOLOGÍA GENERAL; 2015

SAMIGE

It is well-known that E.coli is a microorganism capable of moving individually (swimming) and collectively (swarming). Research groups working with E.coli colonies have observed that bacteria which prepare for swarming undergo remarkable physical changes like length growth and hyper flagellation. Further, it turned out that the typical swimming motility called ?Run and Tumble? is not observed in swarming bacteria colonies. Based on this observation many authors draw the conclusionthat E.coli shows a different individual behavior (motility) after changing from ?swimming? to ?swarming? motility. This conclusion is, however, based on dynamics which are dominated by ?collision? between bacteria and may conceal the intended movement of the individual. We address the question of individual bacterial dynamics in swarming E.coli colonies using simulations of self-propelled rigid bodies with short range interactions. Based on experimental data we, tune our simulation to reproduce swimming motility using agents who perform ?Run and Tumble?. Using our swimming simulation, we study the transition from bacterial swimming to bacterial swarming raising the agent density and the driving force of the agents. The dynamic observables measured during the simulation are in good agreement with experimental data found in swarming E.coli colonies. From our simulation, we conclude that one cannot rule out that bacteria intend to perform ?Run and Tumble? even in swarming colonies.