Xylose utilization promotesreplication within macrophages and systemic infection in mice.

Abstract

The intracellular pathogencan cause systemic diseases via its survival and replication in host macrophages. Xylose is the second most abundant sugar in nature andcan use xylose as its sole carbon source for growth. However, whether xylose utilization contributes to the pathogenicity and intracellular growth ofhas not yet been determined. In this study, we observed that the xylose concentration in macrophages increased duringinfection. Moreover, there was an increase in expression ofxylose catabolic genes (andand the transcriptional regulatory gene of xylose metabolism () in macrophages, revealing the possibility of using host-accumulated xylose byfor intracellular growth. Mutation of eitherorreducedreplication in macrophages and attenuated the colonization of mouse systemic loci (e.g. the liver and spleen), indicating that xylose utilization promotesreplication within macrophages and systemic infection in mice. Moreover, we found that xylose utilization by intracellularwas activated by the cAMP-CRP complex upon detection of low glucose levels in the infected macrophages. Collectively, these findings reveal that although the available glucose decreases during infection,can use xylose, which accumulates in infected macrophages, as an alternative carbon source to promote intracellular replication and virulence.