Imaging of disease dynamics during meningococcal sepsis

Each year 170,000 people around the world die of this type of meningitis, according to the World Health Organization, (WHO).

Bacterial meningitis, as the disease is called, can even spark epidemics: in Africa 250,000 people were affected in a matter of weeks in the late 1990s. Without treatment, mortality among those who contract the disease is 85-90 percent, with treatment some 10-15 percent. Patients also run a high risk of serious disability after recovery.

Only humans are susceptible to infection from meningococci. In its modeling system Ann-Beth Jonsson's research team therefore used mice that produce the human receptor that the bacteria bind to. Marking the bacteria to emit light, the scientists used cameras to monitor their activities in the living mice during the course of the disease.

"The bacteria are almost knocked out by the immune defense system, but then they resurge, this time with alterations in the surface protein. What's more, we discovered that the bacteria aggregate in the thyroid and can impact hormone production during the infection," says Ann-Beth Jonsson.

The study also shows that bacteria that lack a certain adhesin (the protein that the bacteria cells use to adhere to the receptors) could not attach to mucous linings.

Thanks to the new system the research team has developed, it is now possible to rapidly and effectively monitor the function of various vaccine candidates and new drugs, obviating the numerous costly and time-consuming tests that have been necessary until now. At the same time, the system provides a clear picture of the process of infection.

"With these findings as tools, we can continue to study the course of the disease and test vaccines on living organisms. Moreover we will be able to find new strategies for improving the prognoses for those who are affected by meningococcus disorders," says Ann-Beth Jonsson.

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