Lumpy skin disease virus isolation, experimental infection, and evaluation of disease development in a calf.

Lumpy skin disease (LSD) is one of the most economically significant viral diseases of cattle caused by the Lumpy Skin Disease Virus (LSDV), classified as a member of the genus Capripoxvirus and belongs to the family Poxviridae. Nodular skin samples were collected from clinically sick cattle in the districts of Amuru and Wara Jarso Ethiopia to isolate LSD virus. The virus was isolated using primary lamb testis and kidney cells. The isolated LSDV was infected into a healthy calf while maintaining the necessary biosecurity measures to generate skin lesions and to assess disease progression using postmortem examinations. On the fourth day after virus inoculation, the calf developed typical LSD skin nodules with increased rectal temperature, which lasted until the 12th day, when they began to decrease. Viral shedding was detected in nasal, oral, and conjunctival swabs from 6 to 14 days after infection using real-time PCR. Post-mortem tissue specimens tested positive for LSD virus using real-time PCR and virus isolation. This study showed that LSDV were responsible for the LSD outbreaks, and the appearance of typical skin nodules accompanied by fever (> 39.5 °C) defined the virus's virulent status. The experimental infection with the isolated infectious LSDV could serve as a platform for future vaccine evaluation study using an LSDV challenge model.

The first outbreak of feline panleukopenia virus infection in captive Pallas's cats in Xining Wildlife Park.

Introduction: In August 2021, an outbreak of Feline Panleukopenia Virus (FPV) was observed in four 3-month-old Pallas' cats at Xining Wildlife Park. Despite timely intervention, the Pallas'cat cubs continued to experience clinical symptoms including diarrhea, seizures, and decreased white blood cell count, and all four cats died. Methods: FPV clinical suspicions were initially confirmed by positive Polymerase Chain Reaction (PCR) testing. Pathological and immunohistochemical examinations (IHC) were performed on some organs, and the results showed that, encephalitis, viral enteritis, and splenitis occurred. Results: The virus replicates extensively in the cytoplasm of lymphocytes and macrophages in the lamina propria of the small intestine mucosa. A strain of FPV was successfully isolated and culture in CRFK cells. Through molecular identification, sequence analysis, and phylogenetic analysis of the VP2 gene in this strain, we have revealed the presence of a novel synonymous mutation. From July to December 2021, surveillance on stray cats and susceptible wildlife at Xining Wildlife Park indicated widespread FPV transmission. Discussion: The findings highlight the urgent need for ongoing epidemiological monitoring and active disinfection measures to prevent FPV transmission in wildlife parks.

Propagating and banking genetically diverse human sapovirus strains using a human duodenal cell line: investigating antigenic differences between strains.

There are four genogroups and 18 genotypes of human sapoviruses (HuSaVs) responsible for acute gastroenteritis. To comprehend their antigenic and virological differences, it is crucial to obtain viral stocks of the different strains. Previously, we utilized the human duodenum-derived cell line HuTu80, and glycocholate, a conjugated bile acid, to replicate and propagate GI.1, GI.2, and GII.3 HuSaVs (H. Takagi et al., Proc Natl Acad Sci U S A 117:32078-32085, 2020, https://10.1073/pnas.2007310117). First, we investigated the impact of HuTu80 passage number on HuSaV propagation. Second, we demonstrated that taurocholate improved the initial replication success rate and viral RNA levels in fecal specimens relative to glycocholate. By propagating 15 HuSaV genotypes (GI.1-7, GII.1-5, -8, and GV.1-2) and accomplishing preparation of viral stocks containing 1.0 × 109 to 3.4 × 1011 viral genomic copies/mL, we found that all strains required bile acids for replication, with GII.4 showing strict requirements for taurocholate. The deduced VP1 sequences of the viruses during the scale-up of serial passaged virus cultures were either identical or differed by only two amino acids from the original sequences in feces. In addition, we purified virions from nine strains of different genotypes and used them as immunogens for antiserum production. Enzyme-linked immunosorbent assays (ELISAs) using rabbit and guinea pig antisera for each of the 15 strains of different genotypes revealed distinct antigenicity among the propagating viruses across genogroups and differences between genotypes. Acquisition of biobanked viral resources and determination of key culture conditions will be valuable to gain insights into the common mechanisms of HuSaV infection. IMPORTANCE: The control of human sapovirus, which causes acute gastroenteritis in individuals of all ages, is challenging because of its association with outbreaks similar to those caused by human norovirus. The establishment of conditions for efficient viral propagation of various viral strains is essential for understanding the infection mechanism and identifying potential control methods. In this study, two critical factors for human sapovirus propagation in a conventional human duodenal cell line were identified, and 15 strains of different genotypes that differed at the genetic and antigenic levels were isolated and used to prepare virus stocks. The preparation of virus stocks has not been successful for noroviruses, which belong to the same family as sapoviruses. Securing virus stocks of multiple human sapovirus strains represents a significant advance toward establishing a reliable experimental system that does not depend on limited virus-positive fecal material.

Genetic and antigenic characterization of two diarrhoeicdominant rotavirus A genotypes G3P[12] and G14P[12] circulating in the global equine population.

Equine rotavirus species A (ERVA) G3P[12] and G14P[12] are two dominant genotypes that cause foal diarrhoea with a significant economic impact on the global equine industry. ERVA can also serve as a source of novel (equine-like) rotavirus species A (RVA) reassortants with zoonotic potential as those identified previously in 2013-2019 when equine G3-like RVA was responsible for worldwide outbreaks of severe gastroenteritis and hospitalizations in children. One hurdle to ERVA research is that the standard cell culture system optimized for human rotavirus replication is not efficient for isolating ERVA. Here, using an engineered cell line defective in antiviral innate immunity, we showed that both equine G3P[12] and G14P[12] strains can be rapidly isolated from diarrhoeic foals. The genome sequence analysis revealed that both G3P[12] and G14P[12] strains share the identical genotypic constellation except for VP7 and VP6 segments in which G3P[12] possessed VP7 of genotype G3 and VP6 of genotype I6 and G14P[12] had the combination of VP7 of genotype G14 and VP6 of genotype I2. Further characterization demonstrated that two ERVA genotypes have a limited cross-neutralization. The lack of an in vitro broad cross-protection between both genotypes supported the increased recent diarrhoea outbreaks due to equine G14P[12] in foals born to dams immunized with the inactivated monovalent equine G3P[12] vaccine. Finally, using the structural modelling approach, we provided the genetic basis of the antigenic divergence between ERVA G3P[12] and G14P[12] strains. The results of this study will provide a framework for further investigation of infection biology, pathogenesis and cross-protection of equine rotaviruses.

First isolation, identification, and pathogenicity evaluation of an EV-G6 strain in China.

Enterovirus G (EV-G) belongs to the Picornaviridae family and infects porcine populations worldwide. A total of 20 EV-G genotypes (EV-G1 to EV-G20) have been identified. In this study, we isolated and characterized an EV-G strain, named EV-G/YN29/2022, from the feces of diarrheic pigs. This was the first EV-G6 strain isolated in China. Comparison of the whole genome nucleotide and corresponding amino acid sequences showed that the isolate was more closely related to those of the EV-G6 genotype than other genotypes, with the complete genome sequence similarity ranging from 83.7% (Iba46442) to 84.4% (PEV-B-KOR), and corresponding amino acid homology ranged from 96% (Iba46442) to 96.8% (PEV-B-KOR). Similarly, the VP1 gene and corresponding amino acid sequences of EV-G/YN29/2022 were highly similar to those of the EV-G6 genotype (>82.9% and >94.3%, respectively). Thus, the isolated strain was classified as EV-G6 genotype. This was the first EV-G6 strain isolated in China. Pathogenicity analyses revealed that EV-G/YN29/2022 infection caused mild diarrhea, typical skin lesions, and weight reduction. The strain was mainly distributed to the intestinal tissue but was also found in the brain, mesenteric lymph nodes, spleen, and liver. Our results can be used as a reference to further elucidate the epidemiology, evolution, and pathogenicity of EV-G.

Virus Isolation of Epizootic Hemorrhagic Disease Virus in Cell Culture.

Virus isolation is used to assist in the diagnosis and confirmation of viral infections. Successful isolation of a virus is highly dependent upon the quality of starting material. Here we describe the preparation and isolation of epizootic hemorrhagic disease virus (EHDV) from blood and tissue samples in tissue culture flasks (TCFs) through the inoculation of susceptible cell lines including Vero, BHK, and KC cells.

Isolation of porcine circovirus 3 using primary porcine bone marrow-derived cells.

Porcine circovirus 3 (PCV3) was first reported in the United States in 2016; this virus is considered to be involved in diverse pathologies, such as multisystem inflammation, porcine dermatitis and nephropathy syndrome, and reproductive disorders. However, successful isolation of PCV3 using cultured cells has been rare. In this study, we aimed to isolate PCV3 using primary porcine bone marrow-derived cells. Mononuclear cells were isolated from the femur bones of clinically healthy pigs. These primary cells were cultured for 6-10 days post-seeding and infected with PCV3-containing tissue homogenates. The cells were cultured for up to 37 days, and the culture medium was changed every 3-4 days. The growth curve of PCV3 in porcine bone marrow cells revealed a decline in growth during the first 10 days post-infection, followed by an increase leading to > 1010 genomic copies/mL of the cell culture supernatant; moreover, the virus was capable of passaging. The indirect fluorescent antibody assay for PCV3 infection revealed the presence of PCV3 capsid protein in the cytoplasm and nuclei of infected cells. Bone marrow cells were passaged for more than 20 generations (over 5 months), and PCV3 persistently infected the cells. PCV3-infected bone marrow cells expressed mesenchymal markers. These results reflect that primary porcine bone marrow-derived mesenchymal cells are permissive to PCV3 and continuously replicate a high copy number of the PCV3 genome. These findings regarding the high replication rate of PCV3 in bone marrow-derived mesenchymal cells could enhance our understanding of PCV3 pathogenicity.

Evaluation of a qualified MDCK cell line for virus isolation to develop cell-based influenza vaccine viruses with appropriate antigenicity.

We established a qualified Madin-Darby canine kidney cell line (qMDCK-Cs) and investigated its suitability for source virus isolation to develop cell-based seasonal influenza vaccine viruses using vaccine manufacturer cells (Manuf-Cs). When inoculated with 81 influenza-positive clinical specimens, the initial virus isolation efficiency of qMDCK-Cs was exceeded 70%. Among the qMDCK-C isolates, 100% of the A/H1N1pdm09, B/Victoria and B/Yamagata strains and >70% of the A/H3N2 strains showed antigenicity equivalent to that of the contemporary vaccine or relevant viruses in haemagglutination inhibition (HI) or virus neutralization (VN) tests using ferret antisera. These qMDCK-C isolates were propagated in Manuf-Cs (MDCK and Vero cells) (Manuf-C viruses) to develop vaccine viruses. In reciprocal antigenicity tests, ferret antisera raised against corresponding reference viruses and Manuf-C viruses recognized 29 of 31 Manuf-C viruses and corresponding reference viruses, respectively at HI or VN titres more than half of the homologous virus titres, which is the antigenicity criterion for cell culture seasonal influenza vaccine viruses specified by the World Health Organization. Furthermore, ferret antisera against these Manuf-C viruses recognized ≥95% of the viruses circulating during the relevant influenza season with HI or VN titres greater than one-quarter of the homologous virus titres. No cell line-specific amino acid substitutions were observed in the resulting viruses. However, polymorphisms at positions 158/160 of H3HA, 148/151 of N2NA and 197/199 of B/Victoria HA were occasionally detected in the qMDCK-C and Manuf-C viruses but barely affected the viral antigenicity. These results indicated that qMDCK-Cs are suitable for isolating influenza viruses that can serve as a source of antigenically appropriate vaccine viruses. The use of the qMDCK-C isolates will eliminates the need for clinical sample collection, virus isolation, and antigenicity analysis every season, and is expected to contribute to the promotion of vaccine virus development using manufacturer cells.

Surveillance of Feral Swine (Sus scrofa) in the Western USA for Antibodies to Vesicular Stomatitis Virus, 2013-21.

Vesicular stomatitis virus (VSV) outbreaks periodically occur in livestock in the western US and are thought to originate from outside this country. Feral swine (Sus scrofa) have been identified as an amplifying host for vesicular stomatitis New Jersey virus (VSNJV) and have been used to better understand the epidemiology of this virus through serosurveillance. This study aimed to determine if antibodies to vesicular stomatitis Indiana virus (VSIV) and VSNJV were present in feral swine in the western US and to determine if seropositive animals were associated with areas of previously detected VSV in livestock. A total of 4,541 feral swine samples was tested using virus neutralization (VN); samples exhibiting neutralizing activity against one or more of the viruses were confirmed using competitive ELISA (cELISA). Eight sera exhibited neutralizing activity by VN assay and a single serum sample from an animal from Kinney County, Texas sampled in December 2019 tested positive for antibodies to VSIV by cELISA. This finding is supported by a local outbreak of VSIV in horses in the same county in June 2019. The low prevalence of antibodies against VSNJV and VSIV was unexpected but indicates that feral swine in the western US do not represent an endemic reservoir for either of these viruses.

Isolation, identification, and pathogenicity of two novel goose astrovirus from goslings with severe gout in China.

Goose astroviruses (GAstVs) are important pathogens which can cause gout in goslings leading to huge economic losses for the goose farming industry in China. In 2023, an infectious disease characterized by visceral gout broke out in commercial goose farms in Guangxi and Guangdong provinces of China. In this study, two GAstV strains of GXNN and GDCS were successfully isolated from these two disease-ridden goose farms. The complete genomic lengths of these two strains were 7166 bp, and phylogenetic analysis showed that they were both GAstV-2 subtypes. The 3-dimensional structures of the capsid protein were predicted and six characteristic mutation sites at amino acid positions 60, 61, 228, 229, 456 and 523 were found within the strong antigenic regions. A recombination event occurred at 6833-7070 nt between the GAstV TZ03 and Turkey astrovirus CA/00 and this was detected in both the GXNN and GDCS strains. Another recombinant event occurred at 63-2747 nt between the GAstV XT1 and GAstV SDPY and this was detected in the GDCS strain. When 1-day-old goslings were infected with the novel GXNN and GDCS strains, they showed severe visceral gout. This was accompanied by enlarged spleens, liver hemorrhages and urate deposits in the kidneys and ureters and their blood urea nitrogen levels were significantly elevated. The mortality rates of the GXNN- and GDCS-infected groups were pathogenically high at 80 % and 60 %, respectively. These results will promote our understanding of the evolution and epidemic potential of GAstVs in China.

Isolation and Characterization of Contemporary Bovine Coronavirus Strains.

Bovine coronavirus (BCoV) poses a threat to cattle health worldwide, contributing to both respiratory and enteric diseases. However, few contemporary strains have been isolated. In this study, 71 samples (10 nasal and 61 fecal) were collected from one farm in Ohio in 2021 and three farms in Georgia in 2023. They were screened by BCoV-specific real-time reverse transcription-PCR, and 15 BCoV-positive samples were identified. Among them, five BCoV strains from fecal samples were isolated using human rectal tumor-18 (HRT-18) cells. The genomic sequences of five strains were obtained. The phylogenetic analysis illustrated that these new strains clustered with US BCoVs that have been detected since the 1990s. Sequence analyses of the spike proteins of four pairs of BCoVs, with each pair originally collected from the respiratory and enteric sites of one animal, revealed the potential amino acid residue patterns, such as D1180 for all four enteric BCoVs and G1180 for three of four respiratory BCoVs. This project provides new BCoV isolates and sequences and underscores the genetic diversity of BcoVs, the unknown mechanisms of disease types, and the necessity of sustained surveillance and research for BCoVs.

Epidemiological Investigation of Goose Astrovirus in Hebei Province, China, 2019-2021.

The goose astrovirus (GAstV), a key pathogen causing visceral gout and high mortality in geese, has spread widely in China, with frequent outbreaks in recent years. Outbreaks and transmissions of this virus have been reported across China, causing considerable economic losses to the goose industry worldwide, with losses exceeding tens of billions in China alone. However, there is still no effective prevention strategy against this virus. Therefore, continuous monitoring of the genetic diversity of dominant GAstV strains is crucial for developing targeted vaccines and appropriate therapeutics. As a crucial region for goose breeding in China, Hebei Province has previously lacked reports on the epidemiology of GAstV. Hence, investigating the epidemiology of GAstV in Hebei Province is highly important. From January 2019 to December 2021, 474 samples suspected of having a GAstV infection were collected in Hebei Province in this study. Through detailed histological observations, pathological examinations, virus isolation and identification, and genetic diversity analysis, we found that GAstV-2 has become the predominant circulating genotype. However, the presence of GAstV-1 and mixed infections cannot be ignored and should receive increased attention. The findings of this study not only deepened our understanding of GAstV in waterfowl in China but also provided scientific evidence for developing effective prevention and control measures, thereby promoting the healthy development of the goose industry in China.

In Vitro Modeling of Feline Morbillivirus Infections Using Primary Feline Kidney Cells.

Domestic cats are the natural host of feline morbilliviruses (FeMV). Although other species can also be infected (such as dogs and opossums), no laboratory animal infection model is established so far. In vitro models for studying the molecular pathogenesis are therefore needed. For this purpose, propagation and titration of FeMV are key techniques. Unlike other morbilliviruses, such as canine distemper virus (CDV) or measles virus (MV), FeMV is a slow growing virus in cell culture and is difficult to titrate using classical plaque techniques. Here we describe methods for the efficient isolation of FeMV from natural sources (e.g., urine), the propagation of viral stocks, and their titration. In addition, we establish the generation of a three-dimensional infection model mimicking the feline tubular epithelium.

Isolation and Genomic Characterization of Kadipiro Virus from Mosquitoes in Yunnan, China.

Background: Kadipiro virus (KDV) is a species of the new 12 segmented RNA virus grouped under the genus Seadornavirus within the Reoviridae family. It has previously been isolated or detected from mosquito, Odonata, and bat feces in Indonesia, China, and Denmark, respectively. Here, we describe the isolation and characterization of a viral strain from mosquitoes in Yunnan Province, China. Methods: Mosquitoes were collected overnight using light traps in Shizong county, on July 17, 2023. Virus was isolated from the mosquito homogenate and grown using baby hamster kidney and Aedes albopictus (C6/36) cells. Preliminary identification of the virus was performed by agarose gel electrophoresis (AGE). The full-genome sequences of the strain were determined by full-length amplification of cDNAs and sequenced using next-generation sequencing. Results: We isolated a viral strain (SZ_M48) from mosquitoes (Culex tritaeniorhynchus Giles) that caused cytopathogenic effects in C6/36 cells. AGE analysis indicated a genome consisting of 12 segments of double-stranded RNA that demonstrated a "6-5-1" pattern, similar to the migrating bands of KDV. Phylogenetic analysis based on the full-genome sequence revealed that SZ_M48 is more clustered with KDV isolates from Hubei and Shangdong in China than with Indonesian and Danish strains. The identity between SZ_M48 and SDKL1625 (Shandong, China) is slightly lower than that of QTM27331 (Hubei, China), and the identity with JKT-7075 (Indonesia) and 21164-6/M.dau/DK (Denmark) is the lowest. Conclusion: The full-genome sequence of the new KDV strain described in this study may be useful for surveillance of the evolutionary characteristics of KDVs. Moreover, these findings extend the knowledge about the genomic diversity, potential vectors, and the distribution of KDVs in China.

Human intestinal enteroids platform to assess the infectivity of gastroenteritis viruses in wastewater.

Fecal-orally transmitted gastroenteritis viruses, particularly human noroviruses (HuNoVs), are a public health concern. Viral transmission risk through contaminated water results underexplored as they have remained largely unculturable until recently and the robust measuring of gastroenteritis viruses infectivity in a single cell line is challenging. This study primarily aimed to test the feasibility of the human intestinal enteroids (HIE) model to demonstrate the infectivity of multiple gastroenteritis viruses in wastewater. Initially, key factors affecting viral replication in HIE model were assessed, and results demonstrated that the reagent-assisted disruption of 3D HIE represents an efficient alternative to syringe pass-through, and the filtering of HuNoV stool suspensions could be avoided. Moreover, comparable replication yields of clinical strains of HuNoV genogroup I (GI), HuNoV GII, rotavirus (RV), astrovirus (HAstV), and adenoviruses (HAdV) were obtained in single and multiple co-infections. Then, the optimized HIE model was used to demonstrate the infectivity of multiple naturally occurring gastroenteritis viruses from wastewater. Thus, a total of 28 wastewater samples were subjected to (RT)-qPCR for each virus, with subsequent testing on HIE. Among these, 16 samples (57 %) showed replication of HuNoVs (n = 3), RV (n = 5), HAstV (n = 8), and/or HAdV (n = 5). Three samples showed HuNoV replication, and sequences assigned to HuNoV GI.3[P13] and HuNoV GII.4[P16] genotypes. Concurrent replication of multiple gastroenteritis viruses occurred in 4 wastewater samples. By comparing wastewater concentrate and HIE supernatant sequences, diverse HAstV and HAdV genotypes were identified in 4 samples. In summary, we successfully employed HIE to demonstrate the presence of multiple infectious human gastroenteritis viruses, including HuNoV, in naturally contaminated wastewater samples.

Environmental surveillance reveals co-circulation of distinctive lineages of enteroviruses in southwest China's border cities, 2020-2022.

AIMS: Enteroviruses are significant human pathogens associated with a range of mild to severe diseases. This study aims to understand the diversity and genetic characterization of enteroviruses circulated in southwest China's border cities by using environmental surveillance. METHODS AND RESULTS: A total of 96 sewage samples were collected in three border cities and a port located in Yunnan Province, China from July 2020 to June 2022. After cell culture and VP1 sequencing, a total of 590 enterovirus isolates were identified, belonging to 21 types. All PV strains were Sabin-like with ≤6 nucleotide mutations in the VP1 coding region. Echovirus 6, echovirus 21 (a rare serotype in previous studies), and coxsackievirus B5 were the predominant serotypes, which accounted for 21.19%, 18.31%, and 13.39% of the total isolates, respectively. The prevalence of the common serotypes varied across different border cities and periods. Phylogenetic analysis revealed the presence of multiple evolutionary lineages for E21, E6, and E30, some of which formed distinct branches. CONCLUSIONS: High diversity of enteroviruses and distinct lineages of predominant serotypes circulated in southwest China's border cities.

First isolation and characterization of SARS-CoV-2 from COVID-19 patient of North East India.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) responsible for the current pandemic has resulted in over 5 million deaths globally. More than a year has passed, still SARS-CoV-2 panic the public life. Virus isolation is of paramount importance for development of vaccines, in-vitro screening of antiviral compounds, pathogenesis studies, etc., Many cell lines were studied for amplification and replication of SARS-CoV-2 and Vero cells were found to be ideal cell lines for isolation. In May 2020, ICMR-Regional Medical Research Centre, NE region, India, successfully established the SARS-CoV-2 culture system in Vero CCL-81 cell lines. Phylogenetic analyses of the whole genome sequences of the SARS-CoV-2 isolate (EPI_ISL_2501532 | 2020-05-19) showed monophyletic clade G and lineage B.1.1.

Isolation of Epizootic Hemorrhagic Disease Virus Serotype 10 from Culicoides tainanus and Associated Infections in Livestock in Yunnan, China.

Two strains of viruses, JC13C644 and JC13C673, were isolated from Culicoides tainanus collected in Jiangcheng County, Yunnan Province, situated along the border area shared by China, Laos, and Vietnam. JC13C644 and JC13C673 viruses can cause cytopathic effect (CPE) in mammalian cells BHK21 and Vero cells, and cause morbidity and mortality in suckling mice 48 h after intracerebral inoculation. Whole-genome sequencing was performed, yielding complete sequences for all 10 segments from Seg-1 (3942nt) to Seg-10 (810nt). Phylogenetic analysis of the sub-core-shell (T2) showed that the JC13C644 and JC13C673 viruses clustered with the Epizootic Hemorrhagic Disease Virus (EHDV) isolated from Japan and Australia, with nucleotide and amino acid homology of 93.1% to 98.3% and 99.2% to 99.6%, respectively, suggesting that they were Eastern group EHDV. The phylogenetic analysis of outer capsid protein (OC1) and outer capsid protein (OC2) showed that the JC13C644 and JC13C673 viruses were clustered with the EHDV-10 isolated from Japan in 1998, with the nucleotide homology of 98.3% and 98.5%, and the amino acid homology of 99.6% and 99.6-99.8%, respectively, indicating that they belong to the EHDV-10. Seroepidemiological survey results demonstrated that JC13C644 virus-neutralizing antibodies were present in 29.02% (177/610) of locally collected cattle serum and 11.32% (89/786) of goat serum, implying the virus's presence in Jiangcheng, Yunnan Province. This finding suggests that EHDV-10 circulates not only among blood-sucking insects in nature but also infects local domestic animals in China. Notably, this marks the first-ever isolation of the virus in China and its discovery outside of Japan since its initial isolation from Japanese cattle. In light of these results, it is evident that EHDV Serotype 10 exists beyond Japan, notably in the natural vectors of southern Eurasia, with the capacity to infect local cattle and goats. Therefore, it is imperative to intensify the surveillance of EHDV infection in domestic animals, particularly focusing on the detection and monitoring of new virus serotypes that may emerge in the region and pose risks to animal health.

Characterization of a novel recombinant NADC30­like porcine reproductive and respiratory syndrome virus in Shanxi Province, China.

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important pathogens affecting the swine industry. In this report, a novel PRRSV strain SXht2012 was isolated from Shanxi province in China. To identify genetic characteristics of SXht2012, we conducted phylogenetic and homology analyses after sequencing its complete genome. The results revealed that SXht2012 belonged to NADC30-like strain and shared 91.3% nucleotide (nt) identity with strain NADC30. Notably, sequence alignment showed that a distinctive feature in the NSP2 region, where a 131-amino acid (aa) deletion was found in the hypervariable region (HVR). Additionally, variations were also detected in the GP5 protein, specifically in the decoy peptide, T cell peptide, and a potential glycosylation site (aa 32). Furthermore, we also found that SXht2012 was likely a recombination virus originating from NADC30-like and JXA1-like strains, and three recombination breakpoints were identified in the genome at nt positions 1516, 5280 and 6851, which correspond to the NSP2, NSP3, and NSP7 regions. Overall, these findings have significant implications for understanding the genetic variation and evolutionary dynamics of PRRSV strains.

Bovine Parainfluenza-3 Virus Detection Methods and Prevalence in Cattle: A Systematic Review and Meta-Analysis.

Bovine parainfluenza-3 virus (BPI3V) is an important respiratory pathogen in cattle, contributing to syndromes in the bovine respiratory disease complex (BRDC). Despite its significance, the understanding of its prevalence remains fragmented, especially within the larger framework of BRDC. This systematic review and meta-analysis aimed to determine the global prevalence of BPI3V in cattle using varied detection methods and to highlight associated risk factors. Of 2187 initially retrieved articles, 71 were selected for analysis, covering 32 countries. Depending on the detection method employed, the meta-analysis revealed significant variations in BPI3V prevalence. In the general cattle population, the highest prevalence was observed using the antibody detection method, with a proportion of 0.64. In contrast, in cattle with BRDC, a prevalence of 0.75 was observed. For the antigen detection method, a prevalence of 0.15 was observed, exclusively in cattle with BRDC. In nucleic acid detection, a prevalence of 0.05 or 0.10 was observed in the general and BRDC cattle populations, respectively. In virus isolation methods, a prevalence of 0.05 or 0.04 was observed in the general and BRDC cattle populations, respectively. These findings highlight the differences in the detection ability of different methods in identifying BPI3V. Other factors, such as country, study year, coinfections, farm size, the presence of respiratory signs, sex, and body weight, may also affect the prevalence. Most studies were anchored within broader BRDC investigations or aimed at detecting other diseases, indicating a potential under-representation of focused BPI3V research. BPI3V plays an important role in BRDC, with its prevalence varying significantly based on the detection methodology. To further understand its unique role within BRDC and pave the way for targeted interventions, there is an evident need for independent, dedicated research on BPI3V.