The H3N8 low pathogenic avian influenza virus (LPAIV) exhibits broad host tropism, infecting diverse avian and mammalian species, raising concerns about its zoonotic potential. Following the emergence of human infections with H3N8 LPAIV in China, including a fatal case, we investigated the epidemiological and virological characteristics of this virus in Guangdong Province. In 2022, a serological survey revealed H3N8 seroprevalence rates of 10.85% in farmed chickens and 7.97% in ducks. We isolated three H3N8 viruses, designated as A/chicken/Qingyuan/22/2022 (H3N8); A/chicken/Qingyuan/31/2022 (H3N8); and A/chicken/Qingyuan/15/2022 (H3N8), and found that these chicken isolates, like the human isolate A/Changsha/1000/2022, share the same E190 residue. This residue can synergize with sites such as Q226 and G228 to enhance binding affinity for SAα-2,6-Gal. Additionally, they harbor the three amino acid residues N193, W222, and S227. Among these, N193 has the potential to form hydrogen bonds with α2-6-linked glycans, while W222 and S227 may alter the conformational flexibility of the 220-loop. These two effects collectively endow the H3N8 isolates with dual receptor-binding properties. These findings suggest a shift in receptor specificity, potentially facilitating viral adaptation to mammalian hosts. Characterization of viral genome detection dynamics, and histopathology in animal models further elucidated the viral infection dynamics. Our study provides critical insights into the evolutionary trajectory and zoonotic potential of the H3N8 LPAIV.

Since 2021, a novel strain of goose reovirus (GRV) has emerged within the goose farming industry in Guangdong province, China. This particular viral variant is distinguished by the presence of white necrotic foci primarily localized in the liver and spleen, leading to substantial economic losses for the poultry industry. However, the etiology, prevalence and genomic characteristics of the causative agent have not been thoroughly investigated. In this study, we conducted an epidemiological inquiry employing suspected GRV samples collected from May 2021 to September 2022. The macroscopic pathological and histopathological lesions associated with GRV-infected clinical specimens were examined. Moreover, we successfully isolated the GRV strain and elucidated the complete genome sequence of the isolate GD21/88. Through phylogenetic and recombination analysis, we unveiled that the GRV strains represent a novel variant resulting from multiple reassortment events. Specifically, the μNS, λC, and σNS genes of GRV were found to have originated from chicken reovirus, while the σA gene of GRV exhibited a higher degree of similarity with a novel duck reovirus. The remaining genes of GRV were traced back to Muscovy duck reovirus. Collectively, our findings underscore the significance of GRV as a pathogenic agent impacting the goose farming industry. The insights gleaned from this study contribute to a more comprehensive understanding of the epidemiology of GRV in Southern China and shed light on the genetic reassortment events exhibited by the virus.

Since 2020, a novel goose-derived reovirus, characterized by goose hemorrhagic hepatitis, has emerged in the goose breeding industry of Guangdong province, China, leading to significant economic losses in the poultry sector. To study the genetic variation of novel goose reovirus (NGRV) in Guangdong province, this experiment utilized goose embryonic fibroblast cells for virus isolation. RT-PCR was conducted to identify, amplify, clone, and sequence the complete genome of the NGRV isolated from Zhaoqing. The genomic sequences were compared with reference strains to construct a phylogenetic tree. Moreover, animal pathogenicity, excretion patterns, and pathological sections were examined. The results showed that liver and spleen samples from geese suspected of NGRV infection were used for isolation, resulting in the identification of a reovirus presumed to originate from geese, designated as GD218. In terms of genomic structure and sequence homology, GD218 closely resembles the novel duck reovirus, differing significantly from earlier isolated NDRV strains (J18, NP03, SD12, etc.) in genetic composition (nt: 80.6-97.9%, aa: 94.3-98.9%). However, it is similar to strains isolated after 2018, such as XT18, SY, QR, YL, LY20, etc. (nt: 95.3-98.9%, aa: 98.6-99.7%). Therefore, based on phylogenetic analysis, GD218 is hypothesized to be a novel type of goose-origin reovirus homologous to the novel duck reovirus.

Porcine epidemic diarrhea virus (PEDV) is a single-stranded RNA virus with a capsid membrane that causes acute infectious gastrointestinal disease characterized by vomiting, diarrhea, and dehydration in swine. Piglets are more susceptible to PEDV than adults, with an infection rate reaching 90% and a fatality rate as high as 100%. Moreover, PEDV has a rapid transmission rate and broad transmission range. Consequently, PEDV has caused considerable economic losses and negatively impacted the sustainability of the pig industry. The surface spike (S) glycoprotein is the largest structural protein in PEDV virions and is closely associated with host cell fusion and virus invasion. As such, the S protein is an important target for vaccine development. In this article, we review the genetic variation, immunity, apoptosis-induction function, virulence, vaccine potential, and other aspects of the PEDV S protein. This review provides a theoretical foundation for preventing and controlling PEDV infection and serves as a valuable resource for further research and development of PEDV vaccines.

The novel duck reovirus (NDRV) emerged in southeast China in 2005. The virus causes severe liver and spleen hemorrhage and necrosis in various duck species, bringing serious harm to waterfowl farming. In this study, three strains of NDRV designated as NDRV-ZSS-FJ20, NDRV-LRS-GD20, and NDRV-FJ19 were isolated from diseased Muscovy ducks in Guangdong and Fujian provinces. Pairwise sequence comparisons revealed that the three strains were closely related to NDRV, with nucleotide sequence identities for 10 genomic fragments ranging between 84.8 and 99.8%. In contrast, the nucleotide sequences of the three strains were only 38.9-80.9% similar to the chicken-origin reovirus and only 37.6-98.9% similar to the classical waterfowl-origin reovirus. Similarly, phylogenetic analysis revealed that the three strains clustered together with NDRV and were significantly different from classical waterfowl-origin reovirus and chicken-origin reovirus. In addition, the analyses showed that the L1 segment of the NDRV-FJ19 strain was a recombinant of 03G and J18 strains. Experimental reproduction of the disease showed that the NDRV-FJ19 strain was pathogenic to both ducks and chickens and could lead to symptoms of hemorrhage and necrosis in the liver and spleen. This was somewhat different from previous reports that NDRV is less pathogenic to chickens. In conclusion, we speculated that the NDRV-FJ19 causing duck liver and spleen necrosis is a new variant of a duck orthoreovirus that is significantly different in pathogenicity from any previously reported waterfowl-origin orthoreovirus.

随着养鹅业不断走向规模化、交通物流加速和养鹅环境污染,鹅的各种疾病呈现出一些新的特点,如何根据这些特点找到有效减少疾病发生的对策,是养鹅业能否健康发展的重要环节.本文从当前鹅主要流行病的病原学、流行特点、临床症状以及病理变化等方面进行概述,并提出相关防控措施,希望能为鹅病进一步研究和生产有效防控提供理论指导和技术支持.

为探究鸭坦布苏病毒(duck Tembusu virus,DTMUV)GDSH07 株对1 日龄雏麻鸭致病性,本研究利用GDSH07 毒株感染细胞,进行病毒传代后纯化,通过PCR扩增NS5 和E基因并测序确定该毒株所属流行分支,并测定病毒滴度;用病毒液(TCID50 =10-6,0.2 mL)攻毒1 日龄雏麻鸭,观察各组织器官临床剖检病变,并制成组织切片观察其组织病理变化,荧光定量PCR检测各组织器官的病毒载量.结果显示:将病料研磨液接种至鸭胚成纤维细胞(DEF)和BHK-21 细胞后 72h均出现明显细胞病变,遗传演化分析结果显示本研究毒株GDSH07 属于国内流行毒株clade2.2 分支;1 日龄雏鸭攻毒试验中,攻毒组雏鸭各组织器官(肝脏、脾脏、胸腺、法氏囊、脑)均出现不同程度损伤,其中肝脏、脾脏、胸腺、法氏囊等组织器官病毒载量均在攻毒后3d达到峰值,脑在7d达到峰值,随后逐渐下降.本研究对了解我国当前DTMUV流行株的致病性具有一定意义.

近年来,幼鸽疾病综合征(Young pigeon disease syndrome,YPDS)在全球广泛传播,给养鸽业造成巨大经济损失,目前对YPDS的研究较少,无诊断标准,且无特效药物和疫苗,对该病的防控带来巨大挑战.为更好地了解该综合征,该文从YPDS病因、流行情况、诊断方法及防控措施等方面进行系统阐述,以期为YPDS的防治提供参考.参考国内外近三十年相关文献,对可能导致YPDS的病原进行系统阐述,并对每种诊断方法及防治措施进行总结.YPDS主要是由鸽圆环病毒(Pigeon circovirus,PiCV)、鸽疱疹病毒(Pigeon herpesvirus,PiHV)、鸽腺病毒(Pigeon adenovirus,PiADV)共同引发的一种多因素疾病,可导致7-15周龄幼鸽死亡.主要临床症状表现为精神沉郁、羽毛凌乱、厌食、呕吐、腹泻等.该综合征目前防控措施主要为加强饲养管理.该文总结了有关YPDS病因、诊断方法及防控措施,以期为生产实践提供参考.

水禽呼肠孤病毒病是当前主要流行且危害水禽养殖最严重的水禽疫病之一.该病因其病原变异快,感染的宿主谱广,导致宿主免疫抑制,进而诱发细菌的继发感染,使该病呈现出多样化、复杂化的特征.该病不同基因型病毒引起的临床表现变化不大,但引起病理变化差异比较大,可表现为肝脾坏死、肝脾出血、肝脾出血同时伴有坏死等多种不同病变.本文在笔者研究基础上,参考结合其他单位研究成果,对当前水禽呼肠孤病毒病的病原学、流行病学特点、临床症状及病理变化等方面进行概述,并提出相关防控措施,希望能为水禽呼肠孤病毒病进一步研究和有效防控提供理论指导和技术支持.

The gut microbial composition of the Luchuan (LC) piglet, one of China’s native breeds, has rarely been studied, especially when compared to other breeds. This study developed a porcine epidemic diarrhea virus (PEDV) infection model in LC and Largewhite (LW) piglets, and analyzed the patterns and differences of intestinal microbial communities and metabolites in piglets of these two breeds after infection. The diarrhea score, survival time, and distribution of viral antigens in the intestine of piglets infected with PEDV differed among breeds, with the jejunal immunohistochemistry score of LW piglets being significantly higher than that of LC piglets (P < 0.001). The results of 16S rRNA sequencing showed differences in microbial diversity and community composition in the intestine of piglets with different breeds between PEDV infection piglets and the healthy controls. There were differences in the species and number of dominant phyla and dominant genera in the same intestinal segment. The relative abundance of Shigella in the jejunum of LC piglets after PEDV infection was significantly lower than that of LW piglets (P < 0.05). The key microorganisms differed in the microbiota were Streptococcus alactolyticus, Roseburia faecis, Lactobacillus iners, Streptococcus equi, and Lactobacillus mucosae (P < 0.05). The non-targeted metabolite analysis revealed that intestinal metabolites showed great differences among the different breeds related to infection. Spearman correlation analysis was conducted to examine any links between the microbiota and metabolites. The metabolites in the intestine of different breeds related to infection were mainly involved in arginine biosynthesis, synaptic vesicle cycle, nicotinic acid and nicotinamide metabolism and mTOR signaling pathway, with significantly positive or negative correlations (P < 0.05) between the various microorganisms. This study provides a theoretical foundation for investigating the application of core microorganisms in the gut of piglets of different breeds in the digestive tracts of those infected with PEDV, and helps to tackle the antimicrobial resistance problem further.

Abstract Chicken infectious anemia virus (CIAV) is an immunosuppressive disease that causes enormous economic loss to the poultry industry worldwide, transmitted vertically and horizontally. In recent years, CIAV outbreaks have frequently occurred in southern China since 2014, especially in the Guangdong province. However, there is a lack of epidemiological studies of CIAV in Guangdong province. We performed PCR by using the serum and tissue samples collected from seven cities of Guangdong province. The PCR-positive tissue samples were inoculated into SPF eggs and MSB1 cells for virus isolation by blind-passages three times. This study isolated and characterized 325 serum samples and four tissue samples, the total positive CIAV rate of 62.15% in serum samples, and all four tissues were positive for the CIAV. However, the virus could only be isolated from MSB1 cells. Sequence analysis revealed that the four isolated comparisons with those in the GenBank showed high nucleotide similarities and were near clade C2. Our data showed over 60% of positive cases for CIAV serological analysis consist of seven cities, Which may lead to severe immunosuppressive effects in chickens. In summary, these findings provide new insights to guide molecular epidemiological surveillance of CIAV in Guangdong province.

Recently, Nyazika and colleagues reported the high levels of pro-inflammatory IL-8 cytokine from influenza-like illness pediatric patients in this journal. 1 Nyazika T.K. Law A. Swarthout T.D. Sibale L. Ter Braake D. French N. et al. Influenza-like illness is associated with high pneumococcal carriage density in Malawian children. J Infect. 2020; 81: 549-556 Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar The influenza virus, a member of the Orthomyxoviridae family, infects an estimate of 5% to 20% of the population and causes about 250,000 to 500,000 deaths worldwide each year. 2 Cromer D. van Hoek A.J. Jit M. Edmunds W.J. Fleming D. Miller E. The burden of influenza in England by age and clinical risk group: a statistical analysis to inform vaccine policy. J Infect. 2014; 68: 363-371 Abstract Full Text Full Text PDF PubMed Scopus (155) Google Scholar There are four types of influenza viruses: A, B, C, and D. Influenza A viruses (IAVs) are responsible for both pandemics and annual seasonal influenza epidemics. Among the 18 hemagglutinin (HA) subtypes and 11 neuraminidase (NA) subtypes of IAVs, the H1N1 subtype was responsible for the 1918 H1N1 (Spanish flu) and 2009 H1N1 (swine flu) pandemic. 3 Taubenberger J.K. Morens D.M. Influenza: the once and future pandemic. Public Health Rep. 2010; 125: 16-26 PubMed Google Scholar Although cytokine responses were conducted for IAVs infections, however, a comprehensive study of the weighted host gene co-expression network analysis to H1N1 virus infection is lacking.

利用雨课堂制作录播课并布置客观题进行教学内容的课前预习,课后应用腾讯课堂和雨课堂均能布置作业的特点进行教学效果的检验和教学互动;应用腾讯课堂在线播放视频及雨课堂课后可以分组讨论特点进行两种平台的复合应用,充分调动学生学习专业的兴趣,所以,本文结合"养犬与养猫学"几年的实践教学,充分挖掘两者相互配合给在线教学带来的促进作用,探讨混合式教学方法的课程设计与应用,充分调动学生自主学习,充分提高学生对课程学习的积极性和主动性,同时找寻教学评价的客观评价方法与科学性,从而为课程教学改革提供有价值的参考资料.

Recently, the emergence of a novel reassortant H7N2 avian influenza virus (AIV) was reported in this journal, and the genetic characteristics suggested this novel H7N2 AIV was a reassortant virus of H7N9 and H9N2 AIVs that are circulating in China. 1 Qiu Y. Sun R. Hou G. Yu X. Li Y. Li J. et al. Novel reassortant H7N2 originating from the H7N9 highly pathogenic avian influenza viruses in China. J Infect. 2019; 79 (PubMed PMID: 31473272. Epub 2019/09/02): 462-470 Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar H9N2 AIV binds to both human and avian receptors efficiently and has caused occasionally human infections in Asia 2 Pan Y. Cui S. Sun Y. Zhang X. Ma C. Shi W. et al. Human infection with H9N2 avian influenza in northern China. Clin Microbiol Infect. 2018; 24 (PubMed PMID: 29104171. Epub 2017/11/07): 321-323 Abstract Full Text Full Text PDF PubMed Scopus (30) Google Scholar . Meanwhile, the H9N2 AIV continued to act as genetic donor to multiple novel AIVs, including H7N9, H10N8, H6N1, H6N2, and H5N1. 3 Liu D. Shi W. Gao G.F Poultry carrying H9N2 act as incubators for novel human avian influenza viruses. Lancet. 2014; 383 (PubMed PMID: 24581684. Epub 2014/03/04): 869 Abstract Full Text Full Text PDF PubMed Google Scholar The novel H7N2 showed distinct antigenicity to the vaccine seed strain, which suggested the importance of continuing surveillance of the prevalence of H7N9 and H9N2 strains. In this study, we report a novel genotype ressortant H9N2 strain, A/chicken/Baise/0701/2019(H9N2) (BS/2019), isolated from an acutely ill chicken farm in Baise city, China during the routine surveillance.

Abstract This study describes a simple method for the large‐scale isolation of pure Toxoplasma gondii tachyzoites and bradyzoites. T. gondii tachyzoites were obtained from infected human foreskin fibroblasts (HFFs) and peritoneal exudates of mice, while tissue cysts containing bradyzoites were collected from chronically infected mice. Harvested cells and brain tissues were incubated in Hanks balanced salt solution (HBSS), containing 0.25% trypsin and 0.5% taurodeoxycholic acid (TDC) for 5 min. Subsequent washes in phosphate buffered saline (PBS) were conducted, and the cell viability of the preparations was good, as determined by flow cytometry and ability to reinfect HFF cells and propagate in mice. The purification procedure allowed for a rapid preparation of pure T. gondii tachyzoites and bradyzoites in sufficient quantity that can be used for downstream procedures. The advantage of the new method is that it is convenient and inexpensive.

AIM:Our aim in this study was to isolate potentially novel strains of fowl adenovirus serotype-4 (FAdV-4) that is currently circulating in broiler chicken flocks in Guangdong Province, China, and to compare nucleotide and amino acid (AA) sequences of their respective hexon genes.MATERIALS AND METHODS:The experiment was carried out on poultry farms experiencing outbreaks of FAdV-4-associated hydropericardium syndrome (HPS). Tissue samples from the hearts and livers of deceased chickens were screened for FAdV-4 infection using hexon gene-specific polymerase chain reaction (PCR).RESULTS:New virus isolates were used to infect 7-day-old chicks, which went onto reproduce typical HPS signs. The hypervariable region of the FAdV-4 hexon gene was PCR-amplified and sequenced. The hexon nucleotide and deduced AA sequence identities were 99.8-99.9% and 99.5-99.8%, respectively, among the four novel isolates. In addition, the new isolates were 97-100% and 96.4-99.9% identical to the nucleotide and deduced AA sequences, respectively, of FAdV-4 hexon genes available in the National Center for Biotechnology Information GenBank database. Phylogenetic analyses, based on the hexon gene sequence, revealed that the new isolates, clustered with FAdV-C; the FAdV-A, FAdV-B, FAdV-D, and FAdV-E viruses, were more distantly related.CONCLUSION:New FAdV-4 isolates from Guangdong Province are similar to those identified in other regions of the world. This information provides critical insight into HPS epidemiology and provides a perspective for monitoring outbreaks and developing strategies for disease prevention.