University of Bath and Exeter researchers teamed up to develop the first ever system that allows them to follow the progress of bacterial infection in real-time, with living organisms. Traditional studies of bacterial infection are done after the death of the infected organism - in a petri dish - and lack key processes and cellular signals that play an integral part in the infection process.

Dr. Will Wood, Research Fellow in the Department of Biology & Biochemistry at the University of Bath, explained: “Cells often behave very differently once they have been taken out of their natural environment and cultured in a petri dish.

“In the body, immune surveillance cells such as hemocytes (or macrophages in vertebrates) are exposed to a battery of signals from different sources. The cells integrate these signals and react to them accordingly.

“Once these cells are removed from this complex environment and cultured in a petri dish these signals are lost. Therefore it is really important to study whole organisms to fully understand how bacteria interact with their host.”

To make their videos, the team injected fluorescently tagged bacteria into developing fruit fly embryos, and observed the interactions using time-lapse confocal microscopy. The results play out like a movie, and will help researchers better understand the infection process. In the future, the scientists hope to repeat the experiments using human pathogens, such as Listeria and Trypanosomes - the study of which may lead to enhanced antibacterial treatments.

Dr. Nick Waterfield, co-author on the study and Research Officer at the University of Bath, said: “To be able to film the microscopic battle between single bacterial cells and immune cells in a whole animal and in real time is astounding.

“It will ultimately allow us to properly understand the dynamic nature of the infection process.”

Professor Richard Ffrench-Constant, Professor of Molecular Natural History at the University of Exeter, added: “For the first time this allows us to actually examine infection in real time in a real animal - it’s a major advance!

See the movie here: http://www.bath.ac.uk/news/images/bacteria-movie.mov

Source: http://www.bath.ac.uk/news/2009/07/27/bacterial-movie/