Chemical mapping of the distribution of viruses into infected bacteria with a photothermal method.

We show that an infrared spectromicroscopy method based on a photo-thermal effect, is able to localize single viruses as well when they are isolated and when they are located inside the bacteria they have infected. In this latter case, although the topography performed by an AFM cannot image the viruses, the AFMIR is able to do so. In addition, we are able to determine different stages of the bacteria infection.