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Salmonella infections can lead to intestinal inflammation and metabolic disorders in birds. However, whether arachidonic acid (ARA) metabolism is involved in Salmonella-induced intestinal inflammation remains unclear. This experiment investigated the changes in cecal flora and ARA metabolism in Hainan Wenchang chickens infected with S. Typhimurium using 16s rDNA sequencing and targeted metabolomics. The results showed that the levels of ARA metabolites were increased in the cecum tissue of Wenchang chickens after infection with S. Typhimurium, including prostaglandin E2 (PGE2), prostaglandin F2α (PGF2α), lipoxin A4 (LXA4), ± 8(9)-EET, ± 11(12)-EET, and ± 8,9-DiHETrE. The content of key enzymes for ARA production and metabolism (Phospholipase A2 PLA2 and Cyclooxygenase-2 COX-2) in chicken cecum tissues was increased after S. Typhimurium infection. The relative mRNA levels of inflammatory factors were also increased after infection, including Interferon-γ (IFN-γ), Transforming growth factor-β1 (TGF-β1), Interleukin-4 (IL-4), and Interleukin-6 (IL-6). In HD11 cells, the use of a cyclooxygenase (COX) inhibitor reduced the increased levels of COX-2 and PGF2α induced by S. Typhimurium infection and effectively reduced the inflammatory response. In addition, the number of beneficial genera (e.g., Bifidobacterium, Lactobacillus, and Odorobacterium) in the cecum of Wenchang chickens was significantly reduced after infection with S. Typhimurium. The present study revealed the structure of cecal flora in S. Typhimurium-infected Wenchang chickens. In addition, this study demonstrated that S. Typhimurium activates the ARA cyclooxygenase metabolic pathway, which in turn mediates the development of intestinal inflammation in Wenchang chickens. The results can provide data support and theoretical support for the prevention and control of avian salmonellosis.

Rotavirus A (RVA) infects a relatively wide host range. Studying the evolutionary dynamics of viral genomes and the evolution of host adaptations can inform the development of epidemiological models of disease transmission. Moreover, comprehending the adaptive evolution of viruses in the host could provide insights into how viruses promote evolutionary advantages on a larger scale at host level. This study aims to determine whether host specificity in codon usage existed. We used the Clustal W function within MEGA X software to perform sequence alignment, followed by construction of a phylogenetic tree based on the maximum-likelihood method. Additionally, Codon W software and EMBOSS were utilized for analysis of codon usage bias index. We analyzed codon usage bias (CUB) of host-specific G genotype VP7 to elucidate the molecular-dynamic evolutionary pattern and reveal the adaptive evolution of VP7 at the host level. The CUB of RV VP7 exhibits significant difference between human and other species. This bias can be primarily attributed to natural selection. In addition, the β-barrel structural domain, which plays a crucial role in viral transmembrane entry into cells, demonstrates a stronger CUB. Our results provide novel insights into the evolutionary dynamics of RVs, cross-species transmission, and virus-host adaptation.

Information on rotavirus C (RVC) infection is lacking, partly because the prevalence of RVC among humans and animals worldwide is undefined. Data on the characteristics of the P genotype among RVC strains are also required. We performed systematic searches on the infection rates of RVC since 1980 based on the literature and gene sequences of the PubMed and GenBank databases. A phylogenetic tree of VP4 genes was constructed to evaluate the distribution of the P genotype of RVC from various hosts. The specific mutation motifs in VP8* with P [2]/P [4]/P [5] specificity were analyzed to elucidate their roles in host range restriction. The rate of RVC infection in humans has fallen from 3% before 2009 to 1%, whereas in animals it has risen from 10% to 25%. The P genotype of RVC showed strict host species specificity, and current human RVC infections are exclusively caused by genotype P [2]. In the VP8* hemagglutinin domain of the P [4]/P [5] genotype of swine RVC, specific insertion or deletion were found relative to the human P [2] genotype, and these motifs are a possible critical factor for host range restriction. Our findings highlight the need for further epidemiological surveillance, preventive strategies, and elucidation of the factors involved in the specific host range restriction of RVC-circulating strains.

Synonymous codon bias in the viral genome affects protein translation and gene expression, suggesting that the synonymous codon mutant plays an essential role in influencing virulence and evolution. However, how the recessive mutant form contributes to virus evolvability remains elusive. In this paper, we characterize how the Senecavirus A (SVA), a picornavirus, utilizes synonymous codon mutations to influence its evolution, resulting in the adaptive evolution of the virus to adverse environments. The phylogenetic tree and Median-joining (MJ)-Network of these SVA lineages worldwide were constructed to reveal SVA three-stage genetic development clusters. Furthermore, we analyzed the codon bias of the SVA genome of selected strains and found that SVA could increase the GC content of the third base of some amino acid synonymous codons to enhance the viral RNA adaptive evolution. Our results highlight the impact of recessive mutation of virus codon bias on the evolution of the SVA and uncover a previously underappreciated evolutionary strategy for SVA. They also underline the importance of understanding the genetic evolution of SVA and how SVA adapts to the adverse effects of external stress.

Abstract Background Brucellosis remains one of the most common zoonotic diseases globally, with more than half million human cases reported annually. Brucellosis is an emerging and re-emerging disease in China since the 1990s. An infectious reservoir constituted by domestic animals with brucellosis, especially ovine and caprine herds, poses a significant threat to public health. The seroprevalence of brucellosis in sheep and goat flocks in a national context is unavailable so far. Therefore, we conducted this systematic review and meta-analysis to assess the overall status of brucellosis in sheep and goats in China in almost two decades. Results The pooled prevalence of brucellosis in ovine and caprine flocks in China increased in 2000–2009 (1.00%; 95% CI, 0.70–1.30) to 2010–2018 (3.20%; 95% CI, 2.70–3.60). The seroprevalence of brucellosis in sheep and goat flocks was higher in Eastern China, with 7.00% of positive rate, than that in any other region, especially Shandong province (18.70%). Brucellosis is highly endemic in some local regions. The high prevalence of brucellosis in agricultural regions is suggestive of a shift of geographic distribution. The pooled prevalence of brucellosis is higher in goat flocks than in sheep flocks in China. Conclusions The overall data in this meta-analysis demands comprehensive intervention measures and further surveillance to facilitate the control of brucellosis in livestock. Further studies aimed at evaluating the risk factors associated with spreads of brucellosis in domestic animals unaddressed so far, and sufficient epidemiological data is important to the exploration and understanding of the prevalent status of brucellosis throughout the country and to disease control.

The original article [1] contained a minor error whereby Table 1 was typeset incorrectly.

Background: Senecavirus A (SVA), a member of the family Picornaviridae, is newly discovered, which causes vesicular lesions, lameness in swine, and even death in neonatal piglets. SVA has rapidly spread worldwide in recent years, especially in Asia. Objectives: We conducted a global meta-analysis and systematic review to determine the status of SVA infection in pigs. Methods: Through PubMed, VIP Chinese Journals Database, China National Knowledge Infrastructure, and Wanfang Data search data from 2014 to July 26, 2020, a total of 34 articles were included in this analysis based on our inclusion criteria. We estimated the pooled prevalence of SVA in pigs by the random effects model. A risk of bias assessment of the studies and subgroup analysis to explain heterogeneity was undertaken. Results: We estimated the SVA prevalence to be 15.90% (1,564/9,839; 95% confidence interval [CI], 44.75–65.89) globally. The prevalence decreased to 11.06% (945/8,542; 95% CI, 28.25–50.64) after 2016. The highest SVA prevalence with the VP1-based RT-PCR and immunohistochemistry assay was 58.52% (594/1,015; 95% CI, 59.90–83.96) and 85.54% (71/83; 95% CI, 76.68–100.00), respectively. Besides, the SVA prevalence in piglet herds was the highest at 71.69% (119/166; 95% CI, 68.61–98.43) (p < 0.05). Moreover, our analysis confirmed that the subgroups, including country, sampling year, sampling position, detected gene, detection method, season, age, and climate, could be the heterogeneous factors associated with SVA prevalence. Conclusions: The results indicated that SVA widely exists in various countries currently. Therefore, more prevention and control policies should be proposed to enhance the management of pig farms and improve breeding conditions and the environment to reduce the spread of SVA. [ABSTRACT FROM AUTHOR]

Bovine herpesvirus type 1 (BoHV-1), a member of the Alphaherpesvirinae, causes a variety of diseases, which result in significant economic losses worldwide. Envelope glycoprotein D (gD) of BoHV-1 plays an important role in viral entry into the permissive cells, and protective immune response. The fine mapping epitope on the gD will contribute to the understanding of viral pathogenesis and development of alternative vaccines against various diseases associated with BoHV-1. We previously reported the preparation of a monoclonal antibody (MAb) 2B6, which was raised by a truncated recombinant gD protein, demonstrating a neutralizing activity against BoHV-1 infection in Madin-Darby bovine kidney cells. This study described the identification of a linear B-cell epitope on gD using MAb 2B6. A series of partially overlapping gD proteins with glutathione S-transferase tag were generated to define the epitope recognized by MAb 2B6. The amino acid (aa) sequence 323GEPKPGPSPDADRPE337 was recognized by MAb 2B6 using Western blot with the variedly truncated recombinant proteins. Importantly, this epitope was highly conserved among the typical members of BoHV-1, indicating that the epitope may be utilized in diagnosis of diseases due to BoHV-1 infection. Furthermore, the minimal linear epitope sequence 323GEPKPGP329 on gD recognized by MAb 2B6 was confirmed using single-aa residue deletion mutation in carboxyl terminal. This finding not only contributes to our understanding of gD of BoHV-1 virion but also shows a potential for the development of vaccine candidates and diagnostic techniques. [ABSTRACT FROM AUTHOR]

Salmonella enterica subsp. enterica serovars are leading causative agents of gastroenteritis in humans and numerous animal species worldwide. The ClpP from Salmonella enterica is responsible for regulation under various stress conditions. We were interested in the effect of ClpP deletion mutation on attenuation of Salmonella enterica subsp. enterica serovar Enteritidis (SE) in chickens. Therefore, SM-6/ΔClpP, deletion of the ClpP gene from a wild-type SE-6 (SM-6) strain, was generated using the phage γ Red homologous recombination. Compared with SM-6, SM-6/ΔClpP represented a retarded growth rate and lower concentration in LB broth with and without 5% NaCl or lower pH values, indicating that it is sensitive to conventional disinfectants. SM-6/ΔClpP represented reduced invasion into macrophages in vitro and an approximate 400-fold attenuation based on cell invasion assay and median lethal dose (LD50) in specific pathogen-free (SPF) chickens. Furthermore, SM-6/ΔClpP showed reduced colonization in the liver and spleen and faster clearance compared with SM-6, indicating a short discharge. The survival rate of 7-day-old SPF chickens immunized with SM-6/ΔClpP against homologous challenge and antibody kinetics indicated that SM-6/ΔClpP provided efficient protection from lethal challenge and induced robust antibody immune responses, demonstrating the potential of live, attenuated SE as a vaccine candidate. [ABSTRACT FROM AUTHOR]

Bovine parainfluenza virus type 3 (BPIV3) is a leading respiratory pathogen of cattle and is often implicated as a causative pathogen of bovine respiratory disease complex (BRDC). Three genotypes (BPIV3a-c) have been tentatively classified based on genetic and phylogenetic analyses. A BPIV3c isolate, designated NX49, was isolated using the Madin-Darby bovine kidney cell culture from cattle in western China, where feedlot cattle with severe respiratory disease symptoms were observed. Hemagglutination assay demonstrated that NX49 had low agglutination activity against guinea pig erythrocytes, whereas SD0835, the first BPIV3c strain reported in China, showed high agglutination activity. Phylogenic analysis indicated that NX49 shared 99.3% whole genome identity with SD0835 and 97.5%-98% similarity with BPIV3c strains isolated from Japan, South Korea, and the United States. NX49 also showed 82.5% nucleotide similarity with NM09, a BPIV3a strain isolated from China. These data suggest that the BPIV3c strains circulating in China are conserved. Moreover, BPIV3a and BPIV3c might concomitantly circulate in feedlot cattle for long durations in China. Further characterizing of such viruses and continued surveillance may help to prevent BRDC caused by BPIV3 and aid in vaccine development. [ABSTRACT FROM AUTHOR]