Related Experiment Video
Updated: Aug 12, 2026
Use of In vivo Imaging to Monitor the Progression of Experimental Mouse Cytomegalovirus Infection in Neonates
Published on: July 6, 2013
Experimental placental transfer of foot-and-mouth disease virus in mice
Abstract:
An attenuated type O foot-and-mouth disease (FMD) virus which was virulent for infant, but not for pregnant, mice proved to be superior to a virulent type C FMD virus in the development of a model system for the study of placental transfer of FMD in mice. When mice were inoculated at day 8 or 12 of gestation with type O FMD virus, the virus was detectable in the maternal pancreas for 3 days and in the placenta for 6 days. Viral levels in the fetus and the amniotic fluid were inconsistent and were apparently due to a spillover from the placental infection. The elimination of the virus from the placenta coincided with the expected production of maternal 7S antibody. Mice inoculated from days 0 to 12 of gestation did not have a significant increase in dead young by day 18 (the day of necropsy). Similarly inoculated mice, when permitted to go to term, produced and raised normal-size litters. Inoculation on day 15 of gestation resulted in an increased number of deaths due to morbidity of the dams. It was concluded that the placenta serves as an active site of infection for FMD virus in pregnant mice, but the fetus is relatively resistant to infection.
Insights
Foot-and-mouth disease (FMD) virus infected the placenta in pregnant mice, but fetuses remained largely resistant. Maternal antibodies helped clear the virus from the placenta.
Area of Science:
- Veterinary Virology
- Maternal-Fetal Medicine
- Immunology
Background:
- Foot-and-mouth disease (FMD) poses significant risks to livestock globally.
- Understanding FMD virus (FMDV) placental transfer is crucial for disease control and prevention in pregnant animals.
- Developing reliable animal models is essential for studying FMDV pathogenesis during gestation.
Purpose of the Study:
- To establish a mouse model for investigating FMDV placental transfer.
- To evaluate the susceptibility of pregnant mice and their fetuses to FMDV infection.
- To determine the role of the placenta as a site of FMDV replication during pregnancy.
Main Methods:
- Utilized an attenuated type O FMDV, superior to type C for modeling placental transfer in mice.
- Inoculated pregnant mice at different gestational stages (days 8, 12, and 15) with FMDV.
- Monitored viral presence in maternal organs, placenta, amniotic fluid, and fetus; assessed pregnancy outcomes.
Main Results:
- FMDV was detected in the maternal pancreas (3 days) and placenta (6 days) post-inoculation.
- Viral presence in fetuses and amniotic fluid was inconsistent, suggesting spillover from placental infection.
- Placental viral clearance correlated with maternal 7S antibody production.
- Inoculation early in gestation (days 0-12) did not significantly impact litter size or survival.
- Later gestation inoculation (day 15) increased dam mortality due to morbidity.
Conclusions:
- The placenta acts as an active site for FMDV infection in pregnant mice.
- The developing fetus exhibits relative resistance to FMDV infection.
- Maternal immune response, specifically 7S antibody production, plays a role in clearing placental infection.
