Infection, haemorrhagia and death of Chick embryos experimentally inoculated with Listeria monocytogenes by the Intra-Allantoic route

Cytopathogenic effects in enterocytelike Caco-2 cells differentiate virulent from avirulent Listeria strains

“…Comparative virulence of listerial strains has been described on the basis of the mouse 50% lethal dose (LD50) following intravenous or intraperitoneal inoculations of normal or immunosuppressed mice or on the basis of a strain's subsequent growth in the spleen or liver (12,15,19,32). The chicken embryo system has also been studied to identify virulent strains (3,17). Since evaluation of the role of strain differences in human disease may have important implications for the prevention of listeriosis and implementation of public health measures, it is desirable to develop a simple, rapid laboratory test that can reliably determine the virulence of a given strain.…”