Abstract

Shigella sonnei encounter numerous different stresses during their growth, survival and infection. In this study, the effect of stress response to pH and starvation wasinvestigated. We studied the survival, adhesion and the morphology of Shigella after its incubation in several pH. Our results show that after 2 h of incubation, the rate of cell survival was proportional to the decrease of pH of the medium, but we also noted that the reduction of the cells viability is significant for the normal cells compared to starved cells. In addition to that, the results proved the evidence that the pH can influence significantly the hydrophobicity of S. sonnei (normal and starved) and their capacity to produce biofilm on Congo red agar and on polystyrene microplate wells.The atomic force micrographs showed a reduction of the cells size after stress.

Key words: Shigella sonnei, starvation, pH, survival, adhesion, morphology.