Antibiotics play an essential role for treating bacterial infections in humans and animals, and treatment failure is potentially fatal for infected hosts. A lot of attention is currently given to bacteria that are genetically resistant to antibiotics and can thereby lead to treatment failure. However, bacteria can evade treatment even if they are not genetically resistant. Specific growth conditions, or interactions with other bacterial strains, can render bacterial cells insensitive to the effects of antibiotics. Understanding how bacteria can evade antibiotics, and how antibiotics can be used in a more effective manner, is important both from a scientific as well as from an applied perspective. We are quantifying how antibiotics impact growth and survival of individual bacterial cells, and how these impacts depend on the growth condition and the composition of the bacterial community.