The arginine/ornithine binding protein ArgT plays an essential role in Brucella to prevent intracellular killing and contribute to chronic persistence in the host

The research article describes, arginine/ornithine binding protein, ArgT plays an essential role in the survival of the infectious intracellular bacterial pathogen Brucella melitensis in macrophages and mice. The highlights of our findings are as follows:-· Deletion of ArgT from B. melitensis resulted in its attenuation in macrophages, which was restored upon complementation with the ArgT expression plasmid.· Macrophages infected with ΔArgT-Brucella produced elevated levels of nitric oxide due to the inability of ΔArgT Brucella to deplete the host intracellular arginine through its importer.·Brucella infection upregulated the host arginine transporter, CAT2B expression in the macrophages.· A defective survival of ΔArgT B. melitensis was observed in the infected mice, which correlated with enhanced nitric oxide production in the mice.Our studies revealed that ArgT in Brucella plays a vital role in preventing intracellular killing and contributing to the chronic persistence of Brucella in the host. Our study highlights the essential role of arginine in clearing intracellular infections and subversion of this host defense by intracellular pathogens for their chronic persistence.This information will help to develop improved preventive and therapeutic strategies for brucellosis.