@article{mbs:/content/journal/jmm/10.1099/00222615-18-3-371, author = "Simonet, M. and Mazigh, D. and Berche, P.", title = "Growth of Yersinia Pseudotuberculosis in Mouse Spleen Despite Loss of a Virulence Plasmid of Mol. WT 47 × 106", journal= "Journal of Medical Microbiology", year = "1984", volume = "18", number = "3", pages = "371-375", doi = "https://doi.org/10.1099/00222615-18-3-371", url = "https://www.microbiologyresearch.org/content/journal/jmm/10.1099/00222615-18-3-371", publisher = "Microbiology Society", issn = "1473-5644", type = "Journal Article", abstract = "SUMMARY A highly virulent strain of Yersinia pseudotuberculosis (LD50 c. 102 bacteria/mouse) harboured two plasmids with mol. wt of 47 × 106 and 61 × 106. The role of these plasmids in virulence was studied in mice with derived strains cured of plasmids. It was confirmed that the plasmid of mol. wt 47 × 106 played a major function in virulence. This was shown both by the increase of the LD50 and the lower rate of multiplication in the spleen obtained with strains cured of the plasmid of mol. wt 47 × 106. The plasmid of mol. wt 61 × 106 did not play any role in virulence. This work also demonstrates that the strain cured of the plasmid of mol. wt 47 × 106 and the plasmid-free strain were able to multiply in the spleens of infected mice during a 7-day period. This suggests that virulence factors not associated with plasmids are also responsible for the bacterial growth in tissues in vivo.", }