Serial passage of PDCoV in cell culture reduces its pathogenicity and its damage of gut microbiota homeostasis in piglets

Abstract

Porcine deltacoronavirus (PDCoV) is an enteropathogen causing severe diarrhea, dehydration, and death in nursing piglets, devastating great economic losses for the global swine industry, and has cross-species transmission and zoonotic potential. There are currently no approved treatments or vaccines available for PDCoV. In addition, gut microbiota has an important relationship with the development of many diseases. Here, the PDCoV virulent HNZK-02 strain was successfully attenuated by serial passage on cell cultures, and the pathogenesis and effects on the gut microbiota composition and metabolic function of the PDCoV HNZK-02-P5 and P150 strains were investigated in piglets. We also found the genetic changes in the S protein during passage in vitro and the gut microbiota may contribute to the pathogenesis of PDCoV, while their interaction molecular mechanism would need to be explored further.