Identification of B-cell epitope on the N protein of type 1 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) using monoclonal antibody and construction of epitope-mutated virus.

The escalating epidemic of PRRSV-1 in China has prompted widespread concern regarding the evolution of strains, disparities in pathogenicity to herds, and immunological detection of emerging strains. The nucleocapsid (N) protein, as a highly conserved protein with immunogenic properties in PRRSV, is a subject of intensive study. In this research, the recombinant His-N protein was expressed based on the N gene of PRRSV-1 using a prokaryotic expression system and then administered to BALB/c mice. A cell fusion protocol was implemented between SP2/0 cells and splenocytes, resulting in the successful screening of a monoclonal antibody against the N protein, designated as mAb 2D7, by indirect ELISA. Western Blot analysis and Indirect Immunofluorescence Assay (IFA) confirmed that mAb 2D7 positively responded to PRRSV-1. By constructing and expressing a series of truncated His-fused N proteins, a B-cell epitope of N protein, 59-AAEDDIR-65, was identified. A sequence alignment of two genotypes of PRRSV revealed that this epitope is relatively conserved in PRRSV, yet more so in genotype 1. Cross-reactivity analysis by Western blot analysis demonstrated that the B-cell epitope containing D62Y mutation could not be recognized by mAb 2D7. The inability of mAb 2D7 to recognize the epitope carrying the D62Y mutation was further determined using an infectious clone of PRRSV. This research may shed light on the biological significance of the N protein of PRRSV, paving the way for the advancement of immunological detection and development of future recombinant marker vaccine.

Long-term co-circulation of multiple influenza A viruses in pigs, Guangxi, China.

Influenza A viruses (IAVs) pose a persistent potential threat to human health because of the spillover from avian and swine infections. Extensive surveillance was performed in 12 cities of Guangxi, China, during 2018 and 2023. A total of 2540 samples (including 2353 nasal swabs and 187 lung tissues) were collected from 18 pig farms with outbreaks of respiratory disease. From these, 192 IAV-positive samples and 19 genomic sequences were obtained. We found that the H1 and H3 swine influenza A viruses (swIAVs) of multiple lineages and genotypes have continued to co-circulate during that time in this region. Genomic analysis revealed the Eurasian avian-like H1N1 swIAVs (G4) still remained predominant in pig populations. Strikingly, the novel multiple H3N2 genotypes were found to have been generated through the repeated introduction of the early H3N2 North American triple reassortant viruses (TR H3N2 lineage) that emerged in USA and Canada in 1998 and 2005, respectively. Notably, when the matrix gene segment derived from the H9N2 avian influenza virus was introduced into endemic swIAVs, this produced a novel quadruple reassortant H1N2 swIAV that could pose a potential risk for zoonotic infection.

Development of a monoclonal antibody specifically recognizing a linear epitope on the capsid protein of the emerging Group III Getah virus.

Getah virus (GETV) is an emerging mosquito-borne alphavirus that can infect horses, pigs and other animals. Given the public health threat posed by GETV, research on its pathogenesis, diagnosis and prevention is urgently needed. In the current study, prokaryotic expression systems were used to express the capsid protein of GETV. This protein was then used to immunize BALB/c mice in order to generate monoclonal antibodies (mAbs). Subsequently, hybridoma cells secreting a mAb (2B11-4) against the capsid protein were obtained using the hybridoma technique. A B cell linear epitope, 18-PAYRPWR-24, located at the capsid protein's N-terminal region was identified using western blotting analysis with the produced mAb, 2B11-4. Sequence alignment indicated that this epitope was highly conserved in group III (GIII) strains of GETV, but varied among the other genotypes. Western blotting showed that mAb 2B11-4 could discriminate Group III GETVs from other genotypes. This study describes the preparation of a mAb against the GETV capsid protein and the identification of the specific localization of B-cell epitopes, and will contribute towards a better understanding of the biological importance of the GETV capsid protein. It will also pave the way for developing immunological detection methods and genotype diagnosis for GETVs.

Construction of and evaluation of the immune response to two recombinant pseudorabies viruses expressing the B119L and EP364R proteins of African swine fever virus.

African swine fever (ASF) is an infectious disease caused by ASF virus (ASFV), which is characterized by high infectivity, rapid onset of disease, and a high mortality rate. Outbreaks of ASFV have caused great economic losses to the global pig industry, and there is a need to develop safe and effective vaccines. In this study, two recombinant pseudorabies virus (PRV) strains, rGXGG-2016-ΔgI/ΔgE-EP364R and rGXGG-2016-ΔgI/ΔgE-B119L, expressing the EP364R and B119L protein, respectively, of ASFV, were constructed by homologous recombination technology. Western blotting and immunofluorescence analysis showed that these foreign proteins were expressed in cells infected with the recombinant strains. The strains showed good genetic stability and proliferative characteristics for 20 passages in BHK-21 cells. Both of these strains were immunogenic in mice, inducing the production of specific antibodies against the expressed ASFV proteins while providing protection against lethal challenge with PRV. Thus, the recombinant strains rGXGG-2016-ΔgI/ΔgE-EP364R and rGXGG-2016-ΔgI/ΔgE-B119L could be used as candidate vaccines for both ASFV and PRV. In addition, our study identifies two potential target genes for the development of safe and efficient ASFV vaccines, provides a reference for the construction of bivalent ASFV and PRV vaccines, and demonstrates the feasibility of developing a live ASFV vector vaccine.

A novel VP1-based enzyme-linked immunosorbent assay revealed widespread Enterovirus G infections in Guangxi, China.

Enterovirus G (EV-G) has recently been shown to affect weight gain and cause neurological symptoms in piglets. However, the serological investigation of EV-G is limited. In this study, we developed a novel serological detection method based on the structural protein, VP1 of EV-G. The intra-assay and inter-assay coefficient variations were 3.2-8.9% and 2.6-8.0%, respectively. There was no cross-reaction of the VP1-based enzyme-linked immunosorbent assay (ELISA) with antisera against the other known porcine viruses. In addition, a comparison was made with other methods including the developed indirect ELISAs based on VP2 and VP3 proteins and western blot (WB) analysis, which demonstrated the reliability of the novel method. Using the VP1-based ELISA, we carried out the first seroepidemiological survey of EV-G in China by testing 1041 serum samples collected from different pig farms in Guangxi from 2019 to 2021. Our results showed that 68.78% of the serum samples and 100% of the pig farms were positive for EV-G, with a relatively high incidence of seropositivity in pigs of different ages. This was specifically evident in fattening pigs and sows, which may suggest that the piglets have experienced an infection with EV-G during their growth process. Our data provide the first serological evidence of EV-G infections in pigs from China and reveal the widespread presence of EV-G infections in Guangxi, China.

Reassortant H9N2 canine influenza viruses containing the pandemic H1N1/2009 ribonucleoprotein complex circulating in pigs acquired enhanced virulence in mice.

The reassortment between avian H9N2 and Eurasian avian-like (EA) H1N1 viruses may have potentially changed from avian-to-mammals adaptation. This study generated 20 reassortant viruses with the introduction of H1N1/2009 internal genes from EA H1N1 virus into H9N2 virus. 12 of these recovered the replication capability both in the lungs and turbinate samples. 10 of 12 obtained PA gene segments from the ribonucleoprotein (RNP) complexes of the EA H1N1 virus, and 3 exhibited extreme virulence. Specially, the combination of PB2, PA and NP genes could overcome the species-specific restriction in human cells. Analysis of the polymerase activities found that introduction of the PA gene resulted in increased polymerase activity. These findings indicated that RNP complexes from EA H1N1 virus could confer an adaptation advantage and high compatibility to avian H9N2 virus. This raises new concerns for public health due to the possible coexistence of H9N2 and EA H1N1 viruses in dogs.

Molecular epidemiological and genetic characterization of pseudorabies virus in Guangxi, China.

Pseudorabies virus (PRV) is an important pathogen that can cause harm to the pig population. Since 2011, there have been a number of large-scale outbreaks of pseudorabies on Chinese farms where animals had been vaccinated with the Bartha-K61 vaccine. In order to understand the epidemiological trend and genetic variations of PRV in Guangxi province, China, 819 tissue samples were collected from swine farms where PRV infection was suspected from 2013 to 2019, and these were tested for infectious wild strains of PRV. The results showed a positive rate of PRV in Guangxi province of 28.21% (231/819). Thirty-six wild-type PRV strains were successfully isolated from PRV-positive tissue samples, and a genetic evolutionary analysis was performed based on the gB, gC, gD, gE, and TK genes. Thirty of the PRV strains were found to be closely related to the Chinese variant strains HeN1-China-2012 and HLJ8-China-2013. In addition, five PRV strains were genetically related to Chinese classical strains, and one isolate was a recombinant of the PRV variant and the vaccine strain Bartha-K61. Amino acid sequence analysis showed that all 36 PRV strains had characteristic variant sites in the amino acid sequences of the gB, gC, gD, and gE proteins. Pathogenicity analysis showed that, compared to classical PRV strains, the PRV variant strains were more pathogenic in mice and had a lower LD50. Taken together, our results show that wild-type PRV infections are common on pig farms in Guangxi province of China and that the dominant prevalent strains were those of the PRV variants. The PRV variant strains also had increased pathogenicity in mice. Our data will provide a useful reference for understanding the prevalence and genetic evolution of PRV in China.

Evaluation of packaging capacity at the genomic 2C/3A junction region in Porcine enterovirus G.

Porcine enterovirus G (EV-G) is endogenous to most pig farming countries worldwide. Reports that a papain-like protease (PLP) gene has been naturally inserted into the 2C/3A junction region of the EV-G genome, has increased the potential public health threats from this virus. We constructed a full-length infectious cDNA clone of EV-G, CH/17GXQZ/2017, in order to determine the packaging capacity at the 2C/3A insertion site. Subsequently, recombinants viruses containing the coding tags, GFP, iLOV and His at the 2C/3A junction region, were synthesized. The infectious virus was successfully rescued only with the insertion of the His-tag, which displayed similar virological and molecular properties to its parental strain. This study determined the packaging capacity of the 2C/3A insertion site, and it provides a practical tool for studying the functions and pathogenic mechanisms of EV-G in pigs.

Replication of Porcine Astrovirus Type 1-Infected PK-15 Cells In Vitro Affected by RIG-I and MDA5 Signaling Pathways.

The interferon (IFN) system is an extremely powerful antiviral response in animal cells. The subsequent effects caused by porcine astrovirus type 1 (PAstV1) IFN activation are important for the host's response to viral infections. Here, we show that this virus, which causes mild diarrhea, growth retardation, and damage of the villi of the small intestinal mucosa in piglets, induces an IFN response upon infection of PK-15 cells. Although IFN-ß mRNA was detected within infected cells, this response usually occurs during the middle stages of infection, after genome replication has taken place. Treatment of PAstV1-infected cells with the interferon regulatory factor 3 (IRF3) inhibitor BX795 decreased IFN-ß expression, whereas the nuclear factor kappa light chain enhancer of activated B cells (NF-κB) inhibitor BAY11-7082 did not. These findings indicate that PAstV induced the production of IFN-ß via IRF3-mediated rather than NF-κB-mediated signaling pathways in PK-15 cells. Moreover, PAstV1 increased the protein expression levels of retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated protein 5 (MDA5) in PK-15 cells. The knockdown of RIG-I and MDA5 decreased the expression levels of IFN-ß and the viral loads and increased the infectivity of PAstV1. In conclusion, PAstV1 induced the production of IFN-ß via the RIG-I and MDA5 signaling pathways, and the IFN-ß produced during PAstV1 infection inhibited viral replication. These results will help provide new evidence that PAstV1-induced IFNs may protect against PAstV replication and pathogenesis. IMPORTANCE Astroviruses (AstVs) are widespread and can infect multiple species. Porcine astroviruses produce mainly gastroenteritis and neurological diseases in pigs. However, astrovirus-host interactions are less well studied, particularly with respect to their antagonism of IFN. Here, we report that PAstV1 acts via IRF3 transcription pathway activation of IFN-ß. In addition, the knockdown of RIG-I and MDA5 attenuated the production of IFN-ß induced by PAstV1 in PK-15 cells and increased efficient viral replication in vitro. We believe that these findings will help us to better understand the mechanism of how AstVs affect the host IFN response.

Molecular Epidemiology of Bovine Enteroviruses and Genome Characterization of Two Novel Bovine Enterovirus Strains in Guangxi, China.

Bovine enterovirus (BEV) is a highly infectious pathogen that may cause respiratory and gastrointestinal disease outbreaks in cattle. This study aimed to investigate the prevalence and genetic characteristics of BEVs in Guangxi Province, China. A total of 1,168 fecal samples from 97 different bovine farms were collected between October 2021 and July 2022 in Guangxi Province, China. BEV was confirmed using a reverse transcription-PCR (RT-PCR) method targeting the 5' untranslated region (UTR), and isolates were genotyped by sequencing their genomes. The nearly complete genome sequences of eight BEV strains showing cytopathic effects in MDBK cells were determined and analyzed. In total, 125 (10.7%) of 1,168 fecal samples were positive for BEV. BEV infection was significantly associated with farming patterns and clinical symptoms (P < 0.05; odds ratio [OR] > 1). Molecular characterization indicated that five BEV strains from this study belonged to EV-E2 and one strain to EV-E4. Two BEV strains (GXNN2204 and GXGL2215) could not be assigned to a known type. Strain GXGL2215 showed the closest genetic relationship with GX1901 (GenBank accession number MN607030; China) in its VP1 (67.5%) and P1 (74.7%) and with NGR2017 (MH719217; Nigeria) in its polyprotein (72.0%). It was also close to the EV-E4 strain GXYL2213 from this study when the complete genome (81.7%) was compared. Strain GXNN2204 showed the closest genetic relationship with Ho12 (LC150008; Japan) in the VP1 (66.5%), P1 (71.6%), and polyprotein (73.2%). Genome sequence analysis suggested that strains GXNN2204 and GXGL2215 originated from the genomic recombination of EV-E4 and EV-F3 and EV-E2 and EV-E4, respectively. This study reports the cocirculation of multiple BEV types and the identification of two novel BEV strains in Guangxi, China, and it will provide further insights into the epidemiology and evolution of BEV in China. IMPORTANCE Bovine enterovirus (BEV) is a pathogen that causes intestinal, respiratory, and reproductive disease infections in cattle. This study reports on the widespread prevalence and biological characteristics of the different BEV types which currently exist in Guangxi Province, China. It also provides a reference for the study of the prevalence of BEV in China.

The complete mitochondrial genome of Pethia padamya (Actinopteri, Cyprinidae).

Pethia padamya (Kullander and Britz, 2008) is a freshwater fish distributed in the Mekong River basin of Thailand. It has beautiful colors and can be used as an ornamental fish. The complete mitochondrial genome of P. padamya was determined using next-generation sequencing technology and its characteristics were analyzed. The mitochondrial genome is a closed circular molecule comprising 16,792 bp, including 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and a major non-coding region. The overall base composition of the mitochondrial genome is 32.47% A, 25.39% C, 26.08% T, and 16.06% G, with a high A + T bias of 58.55%. Phylogenetic analysis revealed P. padamya as a sister group of Pethia conchonius+(Pethia ticto+Pethia cumingii) and Pethia gelius with maximal support, providing support for the monophyly of the genus Pethia based on concatenated nucleotide sequences. The results of this study proved the monophyly of the genus Pethia. These data for the first time provide information on the complete mitochondrial genome of P. padamya and can contribute to further studies on the biodiversity and management of P. padamya.

Isolation and identification of two novel pseudorabies viruses with natural recombination or TK gene deletion in China.

Pseudorabies virus (PRV), the causative agent of Aujeszky's disease, has gained increased attention in China in recent years due to outbreaks of emergent pseudorabies. However, there is limited information about the evolution and pathogenicity of emergent PRV field strains in China. In this study, two PRV field strains were isolated from an intensive pig farm with suspected PRV infection. These were named the GXLB-2015 and GXGG-2016 strains and their growth characteristics together with their genome sequences and pathogenicity were determined. Nucleotide homology and phylogenetic analysis revealed the GXLB-2015 stain was relatively close to the foreign PRV isolated strains with respect to the whole genome sequence. However, it formed an independent branch between the foreign PRV isolates and the previous PRV variants isolated in China. Further recombination and genetic evolution analysis showed that the GXLB-2015 strain was a natural recombinant between the Bartha strain and PRV variants. The GXGG-2016 strain was highly homologous with the Chinese classical strains, but it has a natural deletion of 69 aa in the thymidine kinase (TK) gene. Pathogenicity analysis showed that, the GXLB-2015 strain had the strongest pathogenicity to mice with an LD50 of 103.5, while the GXGG-2016 strain with the TK gene deletion was not pathogenic to mice. Taken together, our data provide direct evidence for the genomic recombination and natural TK gene deletion of PRVs, which may provide a reference for a better understanding of PRV evolution in China and contribute to the clinical control of PRV infection in pig farms.

Insertion of exogenous genes within the ORF1b coding region of porcine astrovirus.

Porcine astrovirus (PAstV) is a common cause of diarrhea in swine farms. The current understanding of the molecular virology and pathogenesis of PAstV is incomplete, especially due to the limited functional tools available. Here, ten sites in the open reading frame 1b (ORF1b) of the PAstV genome were determined to tolerate random 15 nt insertions based on the infectious full-length cDNA clones of PAstV using transposon-based insertion-mediated mutagenesis of three selected regions of the PAstV genome. Insertion of the commonly used Flag tag into seven of the ten insertion sites allowed the production of infectious viruses and allowed their recognition by specifically labeled monoclonal antibodies. Indirect immunofluorescence showed that the Flag-tagged ORF1b protein partially overlapped with the coat protein within the cytoplasm. An improved light-oxygen-voltage (iLOV) gene was also introduced into these seven sites, and only one viable recombinant virus that expressed the iLOV reporter gene at the B2 site was recovered. Biological analysis of the reporter viruses showed that these exhibited similar growth characteristics to the parental virus, but they produced fewer infectious virus particles and replicated at a slower rate. The recombinant viruses containing iLOV fused to ORF1b protein, which maintained their stability and displayed green fluorescence for up to three generations after passaging in cell culture. The porcine astroviruses (PAstVs) expressing iLOV were then used to assess the in vitro antiviral activities of mefloquine hydrochloride and ribavirin. Altogether, the recombinant PAstVs expressing iLOV can be used as a reporter virus tool for the screening of anti-PAstV drugs as well as the investigation of PAstV replication and the functional activities of proteins in living cells.

Description of Gut Mycobiota Composition and Diversity of Caprinae Animals.

The fungal community, also known as mycobiota, plays pivotal roles in host nutrition and metabolism and has potential to cause disease. However, knowledge of the gut fungal structure in Caprinae is quite limited. In this study, the composition and diversity of the gut mycobiota of Caprinae animals from different geographical locations (Anhui, Jilin, Guangxi, Shandong, Shanxi, and Tibet) were comprehensively characterized by analyzing the internal transcribed spacer 2 (ITS-2) sequences of the fungal community. The results showed that Ascomycota and Basidiomycota were the dominant phyla, which, respectively, accounted for 90.86 to 95.27% and 2.58 to 7.62% of sequences in samples from each region. Nonetheless, the structure of the gut mycobiota was largely different in Caprinae animals in the different provinces. Therein, Sporormiaceae and Thelebolaceae were the dominant fungal families in the samples from Tibet, whereas their abundance was generally low in other regions. The intestinal diversity of individuals from Guangxi was higher than that in other regions. In addition, there were 114 differential genera among all regions. Finally, the co-occurrence network revealed 285 significant correlations in cross-family pairs in the guts of Caprinae animals, which contained 149 positive and 136 negative relationships, with 96 bacterial and 86 fungal participants at the family level. This study has improved the understanding of the mycobiota of ruminants and provided support for the improvement in animal health and productivity. IMPORTANCE In this study, we elucidated and analyzed the structure of the gut mycobiota of Caprinae animals from different regions. This study revealed differences in the structure of the gut mycobiota among Caprinae animals from different geographical environments. Based on previous findings, correlations between fungal and bacterial communities were analyzed. This study adds to previous research that has expanded the present understanding of the gut microbiome of Caprinae animals.

Combined hydrothermal and biological treatments for valorization of fruit and vegetable waste into liquid organic fertilizer.

This study investigated the effects of hydrothermal treatment, biological treatment and their combination on nutrients recovery from fruit and vegetable waste (FVW) and evaluated the feasibility of fruit and vegetable waste juice (FVWJ) from the combined treatment as liquid organic fertilizer. In this study, following conditions were determined suitable for FVW treatment: the temperature of 165 °C and retention time of 45 min for hydrothermal treatment, 20 h for biological treatment, and Weissella, as the dominant microbial genus present in FVW, was suggested as inoculum for biological treatment. In the combined treatment, based on the above conditions of hydrothermal and biological treatments, the yield of FVWJ was 93.03 g out of 100 g FVW, and concentrations of organic matter (1.45%, w/w), primary nutrients (0.51%, w/w), and toxic components in the FVWJ complied with the requirements for use concentration in both Chinese and European standards for liquid organic fertilizer. The economic analysis showed the net saving of 13.60 USD per ton FVW, indicating that it is an economical approach to valorize fruit and vegetable waste into liquid organic fertilizer through the combined treatment.

Physical and hydraulic properties of bioretention substrate using hexadecyl trimethyl ammonium bromide (HDTMA) modified zeolite.

This study using hexadecyl trimethyl ammonium bromide (HDTMA) modified zeolite as a component of bioretention substrate, to investigate the effect of HDTMA modification on the basic physical and hydraulic properties of substrate layer. Two different levels of HDTMA modified zeolite (ZHD10 and ZHD50) were mixed with a mixture consists of peat soil, river sand and compost (fixed volumetric proportion at 5:4:1) with varying volumetric percentage (25%, 50%, and 75%) to form substrate media. The modification only changes the physical properties of zeolite and media with zeolite slightly, while significant changes in surface hydrophobicity and hydraulic properties were observed. A distinct decline of saturated hydraulic conductivity (Ks) values of zeolite can be observed after the modification, Ks values drop 36.5% for ZHD10 and 55.1% for ZHD50. In contrast, Ks values of substrate media using zeolite increase after the modification at the same volumetric ratio of zeolite. When 50% of zeolite (v/v%) was used in substrate, Ks for natural zeolite, ZHD10 and ZHD50 was 0.024, 0.038 and 0.075 cm/s, respectively. Such alterations in Ks are associated with the changes of surface hydrophobicity after the modification and ion exchange between modified zeolite and other materials after soaking into water. Changes in water retention characteristics (WRC) curves were in good accord with the variations in Ks, and can be interpreted by the changed Ks of tested materials. The orientations of HDTMA molecules loaded on zeolite surface were suggested to play crucial roles in altering the hydraulic properties of zeolite added substrate.

Prevalence and related factors of Enterocytozoon bieneusi in cattle: A global systematic review and meta-analysis.

Enterocytozoon bieneusi (E. bieneusi) is an important zoonotic microsporidian pathogen that has a variety of hosts. Cattle are reservoir hosts of E. bieneusi, and play an important role in the epidemiology of E. bieneusi. However, no systematic research on the prevalence of E. bieneusi in cattle has been reported. Here, a systematic review and meta-analysis was performed to determine the prevalence of E. bieneusi in cattle. Six databases (PubMed, Web of Science, Springlink, Wanfang, CNKI, and VIP) were used for searching for relevant studies. The quantity of E. bieneusi infection in cattle was extracted and subjected to an estimation for the prevalence in cattle by using a random effects model. In total, forty articles from 12 countries were chosen from 524 studies from inception to 1st June 2021. An overall E. bieneusi prevalence (95% CI) in cattle was 12.9% (2566/19,791, 9.0-14.6%). The highest prevalence of E. bieneusi was 17.3% (13.9-20.3) in South America, and the lowest was 6.5% (4.1 - 9.4) in Africa 6.5%. The prevalence of E. bieneusi after 2016 (11.1%) was lower than 2016 and before (12.3%). Cattle aged 3-12 months had a higher prevalence (14.8%) as compared with cattle aged > 12 months (8.2%). The combined prevalence of E. bieneusi in the dairy cattle was 14.4%, which was higher than that in other species. In the subgroup of season, E. bieneusi prevalence in cattle was higher in spring (17.4%) and autumn (19.7%) than in summer (8.5%) and winter (8.5%). E. bieneusi prevalence in naturally grazed cattle was 3.6% and 13.7% in intensively fed cattle. A total of 83 E. bieneusi genotypes were prevalent in cattle, of which 15 genotypes found in the cattle had previously been found in humans. The global prevalence of E. bieneusi in cattle related to geographical and climate variables were evaluated as well. These data indicated that E. bieneusi was ubiquitous in cattle worldwide and carried a potential risk of infection in humans. Thus, the farm managers should provide a scientific mix of nutrients to improve cattle immunity, keep the environment clean, and disinfect regularly. Collectively, the control of E. bieneusi transmission in cattle is of importance for economic and public health.

Changes of gut microbiota structure in rats infected with Toxoplasma gondii.

Toxoplasma gondii (T. gondii) infection can cause intestinal inflammation in rodents and significantly alters the structure of gut microbiota. However, the effects of different T. gondii genotypes on the gut microbiota of rats remain unclear. In this study, acute and chronic T. gondii infection in Fischer 344 rats was induced artificially by intraperitoneal injection of tachyzoites PYS (Chinese 1 ToxoDB#9) and PRU (Type II). Fecal 16S rRNA gene amplicon sequencing was employed to analyze the gut microbiota structure at different stages of infection, and to compare the effects of infection by two T. gondii genotypes. Our results suggested that the infection led to structural changes of gut microbiota in rats. At the acute infection stage, the microbiota diversity increased, while both diversity and abundance of beneficial bacteria decreased at the chronic infection stage. The differences of microbiota structure were caused by strains of different genotypes. However, the diversity changes were consistent. This study demonstrates that the gut microbiota plays an important role in T. gondii infection in rats. The data will improve our understanding of the association between T. gondii infection and gut microbiota in rodents.

Prevalence of bovine rotavirus among Bovidae in China during 1984-2021: A systematic review and meta-analysis.

Bovine rotavirus (BRV) is a potential zoonotic intestinal pathogen that brings a serious threat to calf health, and has resulted in huge economic losses to China's breeding industry. Here, a systematic review and meta-analysis was conducted to estimate the prevalence of BRV among Bovidae from 1984 to 2021 in China. A total of 64 publications on BRV investigation in China were screened from the databases Chinese National Knowledge Infrastructure (CNKI), Wan Fang Database, Technology Periodical Database (VIP), PubMed, and ScienceDirect. The random-effect model was used to calculate the pooled prevalence of BRV, and the analyzed data were derived from 25 provinces in China. The estimated pooled prevalence of BRV in China was 35.7% (8176/17,292). In addition, the prevalence of BRV in Southwestern China (77.1%; 2924/3600) was significantly higher than that in other regions of China. Regarding geographic and climatic factors, the prevalence of BRV in the subgroup of latitude 30-35° (76.8%; 3303/4659) was significantly higher than that in the subgroup of latitude less than 30° (37.0%; 485/1275) or more than 35° (32.6%; 1703/5722), while the prevalence of BRV in the subgroup of longitude 100-105° (75.4%; 2513/3849) was significantly higher than that in the subgroup of longitude less than 100° (32.6%; 619/2255) or more than 105° (48.9%; 2359/5552). Rainfall was positively correlated with the prevalence of BRV, whereas temperature was negatively correlated with the positive rate of BRV (P < 0.05). Our data showed that the prevalence of BRV was strongly correlated with geographical and climatic conditions. Thus, we recommend that the corresponding prevention and control programs should be formulated according to different geographical conditions. The strengthening of BRV surveillance in areas with high altitude, low temperature, and heavy rainfall may contribute to the decrease of the incidence of BRV infection among Bovidae herds in China.

Dynamic description of temporal changes of gut microbiota in broilers.

The diversity of bacteria and fungi in the gut microbiota of commercial broilers that raised in cages from hatch to the end of the production cycle were examined by an analysis of 3,592 and 3,899 amplicon sequence variants (ASVs), respectively. More than 90% sequences in bacterial communities were related to Firmicutes and Proteobacteria. More than 90% sequences in fungal communities were related to Ascomycota, Basidiomycota, and Glomeromycota. A statistical analysis of the microbiota composition succession showed that age was one of the main factors affecting the intestinal microbial communities of broilers. The increasingly complex community succession of transient microbiota occurred along with an increase of age. This dynamic change was observed to be similar between bacteria and fungi. The gut microbiota had a special structure in the first 3 d after birth of broiler. The microbiota structure was quite stable in the period of rapid skeletal growth (d 14-21), and then changed significantly in the period of rapid gaining weight (d 35-42), thus indicating the composition of gut microbiota in broilers had unique structures at different developmental stages. We observed that several bacteria and fungi occupied key functions in the gut microbiota of broilers, suggesting that the gut homeostasis of broilers might be affected by losses of bacteria and fungi via altering interactions between microbiota. This study aimed to provide a data basis for manipulating the microbiota at different developmental stages, in order to improve production and the intestinal health of broilers.