Porcine reproductive and respiratory syndrome (PRRS) is a highly contagious swine disease and poses a severe economic burden to the global swine industry. Owing to the inadequacy of current prevention and control measures, developing effective antiviral strategies for preventing PRRS epidemics is imperative. Honokiol (HNK) is a bioactive component of the dietary supplement magnolia extract. Here, we demonstrated that HNK exhibited potent antiviral effects against different PRRSV strains in vitro. Mechanistically, HNK was shown to interfere with PRRSV replication rather than attachment, internalization, or release. HNK was further determined to target PRRSV RNA-dependent RNA polymerase to impair viral genomic RNA synthesis. In addition, HNK was found to decrease PRRSV-triggered inflammatory responses. More importantly, HNK was revealed to reduce viral loads and alleviate lung damage in vivo. This study highlights the potential of HNK as an inhibitor of PRRSV and provides novel insights into its antiviral properties.
Hongtao Zhang,Lei Zhang,Ganglin Ren,Hongbin Si,Xingju Song,Xianyong Liu,Xun Suo,Dandan Hu
Worldwide distributed coccidiosis is caused by infection of both Eimeria species and Cystoisospora in the host intestine and causes huge economic losses to the livestock industry, especially the poultry industry. The control of such diseases relies mainly on chemoprophylaxis with anticoccidials, which has led to a very common drug resistance in this field. However, the genetic mechanisms underlying resistance to many anticoccidial drugs remain unknown. In this study, strains of E. tenella resistant to 250 mg/kg monensin were generated and characterized. Forward genetic approaches based on pooled genome sequencing, including experimental evolution and linkage group selection, were used to locate candidate targets responsible for resistance to monensin and diclazuril in E. tenella . A total of 16 nonsynonymous mutants in protein-coding genes were identified in monensin-resistant strains, and two genomic regions with strong selection signals were also detected in diclazuril-resistant strains. Our study reveals the genetic characterization of the experimental evolution and linkage group selection in Eimeria species, and also provides important information that contributes to the understanding of the molecular mechanism of drug resistance in coccidia.