Campylobacter jejuni 11168H Exposed to Penicillin Forms Persister Cells and Cells With Altered Redox Protein Activity

The formation of persister cells is one mechanism by which bacteria can survive exposure to environmental stresses. We show that Campylobacter jejuni 11168H forms persister cells at a frequency of 10-3 after exposure to 100 x MIC of penicillin G for 24 hours. Staining the cell population with a redox sensitive fluorescent dye revealed that penicillin G treatment resulted in the appearance of a population of cells with increased fluorescence. We present evidence, to show this is a consequence of over-expressed redox protein activity in, or associated with, the electron transport chain. The metabolic burst in penicillin G treated C. jejuni cells could lead to limited reactive oxygen species (ROS) formation that might play a role in persister cell formation.