Insights into cross-species infection by coronavirus: Porcine epidemic diarrhea virus infections in the rodent.

Abstract

The cross-species infection of coronaviruses has resulted in several major epidemics since 2003. Therefore, it is of great importance to explore the host ranges of coronaviruses and their features among different hosts. In this study, the porcine epidemic diarrhea virus (PEDV), with swine as the only natural reservoir, was detected in rat fecal samples collected from pig farms. Further animal tests showed PEDV can cause systemic infections in neonate mice and rats. The brain, lung intestine and spleen were all targets for PEDV in rodents in contrast to the intestine being targeted in pigs. Morbidity and mortality vary via different infection routes. PEDV was also detectable in feces after infection, suggesting that the infected rodents were potential infectious sources. Moreover, the cerebric tropism of PEDV was verified in piglets, which had not been identified before. In conclusion, our findings demonstrate that PEDV can cross the species barrier to infect mice and rats through different routes. Although it is highly devastating to piglets, PEDV changes the target organs and turns to be milder when meeting with new hosts. Based on these findings, more attention should be paid to the cross-species infection of PEDV to avoid the emergence of another zoonosis.