The virulence protein PagN contributes to the advent of a hyper-replicating cytosolic bacterial population.

subspecies serovar Typhimurium is an intracellular pathogen that invades and colonizes the intestinal epithelium. Following bacterial invasion, is enclosed within a membrane-bound vacuole known as a -containing vacuole (SCV). However, a subset of has the capability to prematurely rupture the SCV and escape, resulting in hyper-replication within the cytosol of epithelial cells.

From intestine to beyond: entry factors display distinct transcription pattern upon infection in murine models.

The infectious process of bacteria of the genus requires the finely regulated use of various virulence factors. Among them, the type 3 secretion system-1 (T3SS-1) and the Rck and PagN invasins are involved in the internalization of the pathogen within eukaryotic cells, but their precise role in the host and in the pathogenic process is still poorly understood. In this study, we aimed to determine the kinetics of expression of these entry factors in a typhoid fever-like and a gastroenteritis model in mice by imaging using bioluminescent Typhimurium reporter strains carrying chromosomal transcriptional fusions.

In Vivo Tracking of Bacterial Colonization in Different Murine Models Using Bioluminescence: The Example of Salmonella.

Applications of bioluminescence for the in vivo study of pathogenic microorganisms are numerous, ranging from the quantification of virulence gene expression to measuring the effect of antimicrobial molecules on the colonization of tissues and organs by the pathogen. Most studies are performed in mice, but recent works demonstrate that this technique is applicable to larger animals like fish, guinea pigs, ferrets, and chickens. Here, we describe the construction and the utilization of a constitutively luminescent strain of Salmonella Typhimurium to monitor in vivo and ex vivo the colonization of mice in the gastroenteritis, typhoid fever, and asymptomatic carriage models of Salmonella infection.

The Invasin and Complement-Resistance Protein Rck of Salmonella is More Widely Distributed than Previously Expected.

The open reading frame (ORF) on the operon encodes an outer membrane protein responsible for invasion of nonphagocytic cell lines and resistance to complement-mediated killing. Until now, the ORF was only detected on the virulence plasmids of three serovars of Salmonella subsp. (i.