The process of bacterial pathogenesis involves complex and dynamic responses from both pathogen and host. While the host can mount an array of defense mechanisms to counteract an infection, bacterial pathogens utilize a number of virulence mechanisms to help them in their quest to invade, colonize, and infect. The expression pattern of virulence factors such as toxins, adhesions factors, enzymes, and others within the tissue determines the progression and outcome of infection. Deciphering the roles of bacterial effector proteins in the in vivo situation is essential to fully understand the infection process. The last decade has provided major technological developments, enabling dynamic live single cell imaging with high spatio-temporal resolution in vitro as well as in vivo. This review outlines current in vivo imaging techniques with primary focus on multiphoton microscopy, which was only recently adapted for real-time studies of bacterial infections within the host. Only few examples have been published to date, but they illustrate the huge potential real-time analysis of bacterial infections has to identify previously unknown aspects of tissue responses linked to bacterial pathogenesis.
Real-time live imaging to study bacterial infections in vivo. Curr Opin Microbiol. Jan 7 2009
In vitro studies have been essential to describe the molecular details of bacteria-host cell interactions in general and the functions of bacterial effector proteins in particular. Recent advancements in in vivo imaging techniques are facilitating the next logical step to visualize the dynamic infection process as it happens within the living host while analyzing the role of bacterial effector proteins in vivo. Data obtained from this emerging field of ’tissue microbiology’, combined with the massive knowledge base generated from research in ‘cellular microbiology’ will eventually provide a complete picture of the complex infection process.