Streptococcus - growth and division leads to long chains of bacteria (image from lenntech)
It's quite a broad topic which allowed plenty of speakers to address their favourite issues with these bugs, but as well as discussions of the virulence factors, biofilm properties and various different intracellular survival properties of the Streptococcus there were also some talks covering new research mechanisms. Rather than focusing on the properties of the bacteria, these talks were about new methods used to study them.
The one that jumped out at me the most was about using Bioluminescent imaging to track a Strep infection. This appealed to me because the iGEM team next door are working on Bioluminescence so it's a word I've heard a lot over the last eight weeks. By adding bioluminescent bacteria to a mouse model, the course of the infection can be tracked over several weeks (using small animal imagine machines it can be tracked in the same mouse). This provides a far better understanding of the pathogenesis of the bacteria; how it spreads through the body and at what point it is most infectious.
The process of using bioluminescence to track diseases (image from the reference).
Using luminescence to study disease progressions isn't a new idea, but the use of whole animal scanning mechanisms now means that fewer animals have to be sacrificed in order for the study to done. The luminescent tissue does not have to be extracted, and the more natural disease progression can be followed.
Other methods explored included the by-now predictable whole genome study analysis to organise the different types and virulence levels of a Streptococcus suis which leads to meningitis in piglets. Comparative genome hybridization studies allow many genomes to be compared at once, giving a better idea of the differences and similarities between them. This helps to separate the strains into serotypes (different groups), and to compare the differences that lead to virulence. Genome comparison work was also being done for Streptococcus equi species which cause infections in horses.
In other news (pretend that was a smooth transition!) the latest Carnival of Molecular Biology is out over at Thoughtomics. There are some brilliant articles covering the intra-cellular happenings of organisms from bacteria to frogs to Tibetans. If you've ever wondered about noisy bacteria, zombie enzymes or what micro-RNA is, go take a look and visit the submissions.
Timothy C. Doyle, Stacy M. Burns, Christopher H. Contag (2004). In vivo bioluminescence imaging for integrated studies of infection Cellular Microbiology, 303-317 DOI: 10.1111/j.1462-5822.2004.00378.x