The black rat (Rattus rattus) is the only reservoir of plague (Yersinia pestis infection) in Madagascar. 
This thesis permitted to characterise the colonisation scheme, resistance to plague in R. rattus and study 
the selection exerted by pathogens on their hosts :

         Selective pressure exerted by pathogens may lead to fast evolutionary changes in the black rat in
         Madagascar, which has populations resistant to plague in the central highlands area, where plague
         has been endemic for a century, while populations of the lowland area, where the disease is absent,
         are susceptible.

The table of contents and the report (with the associated articles) of the thesis are attached below along
with the english and french abstracts.