The ubiquitous expression of a ‘humanized’ Cdh1 in this mouse allows the investigation of InlA-Cdh1 and InlB-Met interactions in vivo. We have previously taken a different route to generate an InlA and InlB permissive L. monocytogenes mouse infection model through an approach we call pathogen ‘murinisation’ [12]. Based on structural information on the recognition complex of InlA with the N-terminal

domain of Cdh1, two amino acids in InlA were replaced (Vorinostat Ser192Asn and Tyr369Ser), dramatically increasing the binding affinity of murine Cdh1 to InlA [12]. By introducing these two mutations into the listerial inlA locus, a variant strain of L. monocytogenes EGD-e (Lmo-InlAm) was generated which was able to cross the murine intestinal barrier and to

induce symptoms of listeriosis Selleckchem Androgen Receptor Antagonist after oral inoculation [12]. In contrast to the Cdh1 transgenic mouse models, this mouse model permits the analysis of orally acquired listeriosis without the need to cross in ‘humanized’ alleles of Cdh1. In this study, we have employed a previously generated bioluminescent L. monocytogenes EGD-e strain (Lmo-InlA-mur-lux) ‘murinised’ for the two Ser192Asn and Tyr369Ser inlA mutations [17] and a ‘non-murinised’, isogenic control strain (Lmo-EGD-lux) to analyse host responses after oral infection in four different inbred strains of mice. C3HeB/FeJ, A/J, BALB/cJ, and C57BL/6J mice were intragastrically inoculated with Lmo-InlA-mur-lux and Lmo-EGD-lux and bacterial

AG-881 mw dissemination to internal organs was analysed using bioluminescent in vivo imaging (BLI). These mouse inbred strains were chosen for the BCKDHA study as they represent priority strains for the mouse phenome project [18] and their degree of host resistance to oral L. monocytogenes infection has never been investigated and compared in a single study under identical infection challenge conditions. We report here that infection with murinised Listeria resulted in earlier onset of listeriosis compared to infections with the non-murinised Listeria strain in different mouse genetic backgrounds. BLI enabled accurate measurement of bacterial dissemination over consecutive days in the acute stage of disease and showed that Lmo-InlA-mur-lux disseminated earlier from the intestine to target organs in the C3HeB/FeJ, A/J, and BALB/cJ mice. However, no increase in dissemination to the brain was detected, revealing that Listeria uses different mechanisms to cross the intestinal epithelium and to cross the blood–brain barrier. Results Dynamics of Lmo-InlA-mur-lux and Lmo-EGD-lux dissemination visualized by BLI To compare the dissemination dynamics of the murinised and wildtype L.