Table 1.
General features of the L. monocytogenes QOC1 and QOC2 genomes.
Figure 1.
Maximum likelihood phylogenetic tree of Listeria monocytogenes strains based on MLST loci.
L. monocytogenes sequence types are indicated („ST“); „CC“ denotes clonal complexes. The tree is based on concatenated full-length MLST gene sequences and was calculated with MEGA 5 [27] using the Tamura-Nei model. Bootstrap values (500× resampling) are indicated at the respective nodes.
Figure 2.
Survival of L. monocytogenes QOC1 and QOC2 in minimal media adjusted to pH 2, pH 3, pH 11 and pH 12; and in gastric fluid.
Values, given as percentage of survival, represent mean values ± SD of four biological replicates performed in triplicate. *indicates statistical significant differences (P<0.05) between QOC1 and QOC2. n.d.: not detectable.
Figure 3.
Genomic organization of the hypervariable hotspot 9 region in L. monocytogenes genomes harbouring homologues to proteins from plasmid pLMIV of L. monocytogenes FSL J1–208.
Homologous proteins are shown as the same color. pLMIV and L. monocytogenes EGDe locus_tags are indicated.
Table 2.
Predicted genes in the hypervariable hotspot 9 region of the L. monocytogenes QOC1 genome.
Figure 4.
Invasion efficiency and intracellular proliferation of L. monocytogenes strains.
Invasion efficiency (panel A and B) and intracellular growth coefficient (IGC, panel C) of type strain EGDe, QOC1 and QOC2 using four different human cell lines (intestinal epithelial Caco2, hepatocytic HepG2 and macrophage-like U937 and THP1 cells) and primary mouse bone-marrow derived macrophages (mBMDM). Values represent mean values ± SD of four biological replicates performed in duplicate. Different letters indicate statistically significant differences (P<0.05).