This study assesses the impacts of the COVID-19 pandemic on Chinese residents' food safety knowledge and behavior, and explores the possible influence mechanism, namely, focus on media information. The study is based on internet survey data of 1 373 residents in China. A series of econometric models are developed to estimate food safety knowledge and behavior of residents. Both the descriptive and econometric results indicate that the existence of COVID-19 cases in a community has a significantly positive effect on residents' food safety knowledge and behavior. Residents focusing on food safety-related information tend to have higher food safety knowledge and practice food safety behavior. When controlling the variable focused on food safety-related information, the marginal effects of the existence of COVID-19 cases in a community on residents' food safety knowledge and behavior significantly decrease. However, the decrease in consumers' food safety knowledge is quite minor. Hence, the COVID-19 pandemic indeed improves Chinese residents' food safety knowledge and behavior, while focus on food safety-related information is an important mechanism for improving food safety behavior. Moreover, the estimation results of the simultaneous equations model reveal that consumers' food safety knowledge has a significant and positive effect on their food safety behavior. Heterogeneous impacts of the COVID-19 pandemic on residents' food safety knowledge and behavior among different regions and income groups are observed. The findings of this study provide evidence that public health events could enhance residents' safety awareness and behavior, while residents' focus on relevant information plays an important role in improving knowledge and impacting behavior.

The nonstructural protein 10 (nsp10) of porcine reproductive and respiratory syndrome virus (PRRSV) encodes for helicase which plays a vital role in viral replication. In the present study, a truncated form of nsp10, termed nsp10a, was found in PRRSV-infected cells and the production of nsp10a was strain-specific. Mass spectrometric analysis and deletion mutagenesis indicated that nsp10a may be short of about 70 amino acids in the N terminus of nsp10. Further studies by rescuing recombinant viruses showed that the Glu-69 in nsp10 was the key amino acid for nsp10a production. Finally, we demonstrated that nsp10a exerted little influence on the growth kinetics of PRRSV

Porcine reproductive and respiratory syndrome virus (PRRSV) actively induces cell apoptosis both and , which can contribute critically to viral pathogenesis. Previous studies have shown that the PRRSV nonstructural protein 4 (nsp4) is an important mediator of this process, but the underlying molecular details remain poorly understood. In this study, we found that the PRRSV nsp4 interacted with the mitochondrial inner membrane protein cytochrome c1 (cyto.c1) and induced its proteolytic cleavage. Interestingly, the cleaved N-terminal fragment of cyto.c1 was found to exert apoptotic activity, which could cause mitochondrial fragmentation, resulting in apoptotic cell death. And RNA interference (RNAi) silencing experiments further confirmed the crucial role which cyto.c1 played in nsp4- and PRRSV-induced cell apoptosis. Thus, our data provide an important piece of mechanistic clues for PRRSV-induced cell apoptosis and also elucidate a novel mechanism for the 3C-like proteases in this finding.

Middle East respiratory syndrome coronavirus (MERS-CoV), a member of the family, is the causative pathogen for MERS that is characterized by high fever, pneumonia, acute respiratory distress syndrome (ARDS), as well as extrapulmonary manifestations. Currently, there are no approved treatment regimens or vaccines for MERS. Here, we generated recombinant nonvirulent Newcastle disease virus (NDV) LaSota strain expressing MERS-CoV S protein (designated as rLa-MERS-S), and evaluated its immunogenicity in mice and Bactrian camels. The results revealed that rLa-MERS-S showed similar growth properties to those of LaSota in embryonated chicken eggs, while animal immunization studies showed that rLa-MERS-S induced MERS-CoV neutralizing antibodies in mice and camels. Our findings suggest that recombinant rLa-MERS-S may be a potential MERS-CoV veterinary vaccine candidate for camels and other animals affected by MERS.

Farm animals are sources of meat, milk and eggs for the humans, and animal health ensures the quality and security of these agricultural and sideline products. The animal raising conditions in livestock stations and poultry houses play vital roles in both animal health and production. One of the major factors affecting raising conditions, relative humidity, has not received much attention even though it is important for animal husbandry. In this review, we summarize the impacts of relative humidity on animal health and welfare to draw attention for its importance in the improvement of animal raising conditions in the future.

H9 subtype avian influenza virus (AIV) and infectious bronchitis virus (IBV) are major pathogens circulating in poultry and have resulted in great economic losses due to respiratory disease and reduced egg production. As similar symptoms are elicited by the two pathogens, it is difficult for their differential diagnosis. So far, no reverse transcription-polymerase chain reaction (RT-PCR) assay has been found to differentiate between H9 AIV and IBV in one reaction. Therefore, developing a sensitive and specific method is of importance to simultaneously detect and differentiate H9 AIV and IBV. In this study, a duplex RT-PCR (dRT-PCR) was established. Two primer sets target the hemagglutinin (HA) gene of H9 AIV and the nucleocapsid (N) gene of IBV, respectively. Specific PCR products were obtained from all tested H9 AIVs and IBVs belonging to the major clades circulating in China, but not from AIVs of other subtypes or other infectious avian viruses. The sensitivity of the dRT-PCR assay corresponding to H9 AIV, IBV and mixture of H9 AIV and IBV were at a concentration of 1×10, 1.5×10 and 1.5×10 50% egg infective doses (EID) mL, respectively. The concordance rates between the dRT-PCR and virus isolation were 99.1 and 98.2%, respectively, for detection of samples from H9N2 AIV or IBV infected chickens, while the concordance rate was 99.1% for detection of samples from H9N2 AIV and IBV co-infected chickens. Thus, the dRT-PCR assay reported herein is specific and sensitive, and suitable for the differential diagnosis of clinical infections and surveillance of H9 AIVs and IBVs.

Previous studies have shown that octamer-binding transcription factor 4 (Oct4) plays a significant role in early embryonic development of mammalian animals, and different expression levels induce multi-lineage differentiation which are regulated by DNA methylation. To explore the relationship between the methylation pattern of gene exon 1 and embryonic development, in this work, five different tissues (heart, liver, lung, cerebrum and cerebellum) from three germ layers were chosen from low age (50-60 d) and advanced age (60-70 d) of fetal cattle and the differences between tissues or ages were analyzed, respectively. The result showed that the DNA methylation level of gene exon 1 was significant different (<0.01) between any two of three germ layers in low age (<60 d), but kept steady of advanced age (>0.05) (>60 d), suggesting that 60-d post coital was an important boundary for embryonic development. In addition, in ectoderm (cerebrum and cerebellum), there was no significant methylation difference of gene exon 1 between low age and advanced age (>0.05), but the result of endoderm (liver and lung) and mesoderm (heart) were on the contrary (<0.01), which indicated the development of ectoderm was earlier than endoderm and mesoderm. The methylation differences from the 3rd, 5th and 9th CpG-dinucleotide loci of gene exon 1 were significantly different between each two of three germ layers (<0.05), indicating that these three loci may have important influence on bovine embryonic development. This study showed that bovine germ layers differentiation was significantly related to the DNA methylation status of gene exon 1. This work firstly identified the DNA methylation profile of bovine gene exon 1 and its association with germ layers development in fetus and adult of cattle. Moreover, the work also provided epigenetic information for further studying bovine embryonic development and cellular reprogramming.

The objective of the present investigation was to estimate the prevalence of infection and co-infection with porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV) and porcine circovirus type 2 (PCV-2) in pigs in China. A total of 372 tissues or serum samples collected from pigs distributed in 9 provinces/municipalities of China during the period from February 2011 to November 2012 were assayed for antigens and antibodies using enzyme linked immunosorbent assay (ELISA) technique, while the PCR was designed for the detection of the PRRSV, CSFV and PCV-2, respectively. The total positive rate of PRSSV, CSFV and PCV-2 was 9.14% (34/372), 50.00% (186/372), 37.10% (138/372) and 3.23% (12/372), respectively. Among the 34 positive samples, 26 samples were simultaneously infected with and viruses, while the remaining eight samples were infected with alone. In addition, the co-infection rate of with PRSSV, with PRSSV and CSFV, with PRSSV and PCV-2, with CSFV and PCV-2, with PRSSV, CSFV and PCV-2 was 1.61% (6/372), 4.03% (15/372), 0.27% (1/372), 0.27% (1/372) and 0.81% (3/372), respectively. The results of the present survey revealed that PRRSV and CSFV were the common pathogens co-existing with porcine toxoplasmosis in China, and both of them could increase the chances of infection in pig. This is the first report of co-infections with viruses in pigs. It is very important to understand the interactions of parasite and virus, and can be used as reference data for the control and prevention of co-infections of and viruses in pigs.

The reverse genetics for classical swine fever virus (CSFV) is currently based on the transfection of transcribed RNA from a viral genomic cDNA clone, which is inefficient and time-consuming. This study was aimed to develop an improved method for rapid recovery of CSFV directly from cloned cDNA. Full-length genomic cDNA from the CSFV Shimen strain, which was flanked by a T7 promoter, the hepatitis delta virus ribozyme and T7 terminator sequences, was cloned into the low-copy vector pOK12, producing pOKShimen-RzTΦ. Direct transfection of pOKShimen-RzTΦ into PK/T7 cells, a PK-15-derived cell line stably expressing bacteriophage T7 RNA polymerase, allowed CSFV to be rescued rapidly and efficiently, i.e., at least 12 h faster and 31.6-fold greater viral titer when compared with the transcription-based rescue system. Furthermore, the progeny virus rescued from PK/T7 cells was indistinguishable, both and , from its parent virus and the virus rescued from classical reverse genetics. The reverse genetics based on intracellular transcription is efficient, convenient and cost-effective. The PK/T7 cell line can be used to rescue CSFV directly from cloned cDNA and it can also be used as an intracellular transcription and expression system for studying the structure and function of viral genes.

Coccidiosis is caused by intra-cellular infection of spp., which goes through a complex life cycle in the intestinal mucosa of infected hosts. Specific immunoglobulins (IgY) could be produced in egg yolk by immunizing hens with specific antigens. In the present study, we cloned the gene, expressed the GST-GAM56 fusion protein and raised IgY to GST-GAM56 in hens. The anti-GST-GAM56 IgY antibody was isolated and used to treat chickens infected with oocysts. Intramuscular injection of the antibodies provided minimal protection against parasite infection. However, oral dosing of the IgY 3 or 5 d after oocyst inoculation significantly improved body weight gain, reduced oocyst output and intestinal lesion score were reduced at 3 or 5 d after oocyst challenging, compared to the untreated control group. Our findings suggest that the IgY to gam56 could be an effective prophylactic or therapeutic agent against infection in chickens and should have a practical application value.