The Mongolian gerbil as a model for human listeriosis

Abstract

Listeria monocytogenes is a foodborne pathogen than can cause spontaneous abortion and serious illness in neonates. Dose-response data on invasion and adverse pregnancy outcomes in Mongolian gerbils after oral challenge with L. monocytogenes were collected and compared to other animal models of listeriosis. Invasion of maternal organs occurred in dams exposed to ≥10^7 CFU L. monocytogenes, while fetal invasion occurred in dams exposed to ≥10^5 CFU. Fetal death occurred only in the highest dose group (10^9 CFU). Using fetal data, an ID50 of 2.60 × 10^6 CFU was calculated, while the LD50 was estimated to lie between 5 × 10^6 and 5 × 10^8 CFU. These results indicate that the gerbil is not more sensitive to L. monocytogenes invasion and adverse outcomes than some of the other animal models of listeriosis, namely the guinea pig and nonhuman primate.