Two groups have shown how Salmonella bacteria can resist antibiotics.

Dirk Bumann of the University of Basel in Switzerland and his colleagues infected mice with modified Salmonella strains that glow green when they divide. They found varying rates of division in different tissues, and most of the bacteria that survived antibiotic treatment had a moderate growth rate.

In a separate study, Médéric Diard at the Swiss Federal Institute of Technology in Zurich and his co-workers found that whereas antibiotics kill off less-dangerous Salmonella mutants in the mouse gut cavity, the more-virulent strains escape by hiding inside the gut tissue. After antibiotic treatment ended, the more-virulent bacteria repopulated the gut.

The findings could point to new strategies for antibiotic treatment, the authors say.

Cell 158, 722–733 (2014) ; Curr. Biol. http://doi.org/t7z (2014)