Animal model is very important for anti-EV71 (enterovirus 71) drug and vaccine development. 1-day-old suckling EV71 mouse model is the main in vivo model used in China. 1-day-old suckling EV71 mouse is too small to perform antiviral experiment. And the route of administration and dosage capacity are also restricted. A strong virulence EV71 virus strain was selected after screening from five EV71 strains with 1-day-old suckling mice. A mouse-adapted EV71 strain with increased virulence in 12-day-old suckling mice, EV71-M5, was generated after five serial passages of the parental EV71 strain in mice. Virus titers of EV71 infected mice heart, liver, spleen, lung, kidney, small intestine, brain and muscle tissue were determined by cytopathic effect (CPE) assay. The virus used in this model is the first isolated EV71 strain in China. And 2-week-old suckling mice were used in this model. This is a supplement for the EV71 animal model in China. Establishment of this EV71 model will provide an attractive platform for anti-EV71 vaccine and drug development.
Animals ; Disease Models, Animal ; Enterovirus A, Human ; isolation & purification ; physiology ; Enterovirus Infections ; Female ; Heart ; virology ; Intestines ; virology ; Mice ; Mice, Inbred BALB C ; Muscles ; virology ; Viral Load ; Virulence

Adult ; Antibodies, Viral/isolation & purification* ; COVID-19/virology* ; Feces/chemistry* ; Female ; Humans ; Intestines/virology* ; Male ; RNA, Ribosomal, 16S/genetics* ; RNA, Viral/isolation & purification* ; SARS-CoV-2/pathogenicity*

In this study, apoptosis was induced by new type gosling viral enteritis virus (NGVEV) in experimentally infected goslings is reported in detail for the first time. After 3-day-old goslings were orally inoculated with a NGVEV-CN strain suspension, the time course of NGVEV effects on apoptotic morphological changes of the internal tissues was evaluated. These changes were observed by histological analysis with light microscopy and ultrastructural analysis with transmission electron microscopy. DNA fragmentation was assessed with a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and DNA ladder analysis. A series of characteristic apoptotic morphological changes including chromatin condensation and margination, cytoplasmic shrinkage, plasma membrane blebbing, and formation of apoptotic bodies were noted. Apoptosis was readily observed in the lymphoid and gastrointestinal organs, and sporadically occurred in other organs after 3 days post-infection (PI). The presence and quantity of TUNEL-positive cells increased with infection time until 9 days PI. DNA extracted from the NGVEV-infected gosling cells displayed characteristic 180~200 bp ladders. Apoptotic cells were ubiquitously distributed, especially among lymphocytes, macrophages, monocytes, and epithelial and intestinal cells. Necrosis was subsequently detected during the late NGVEV-infection phase, which was characterized by cell swelling, plasma membrane collapse, and rapidly lysis. Our results suggested that apoptosis may play an important role in the pathogenesis of NGVE disease.
*Adenoviridae/classification/pathogenicity ; Adenoviridae Infections/pathology/*veterinary/virology ; Animals ; *Anseriformes ; *Apoptosis ; Bird Diseases/*virology ; DNA Fragmentation ; Enteritis/*veterinary/virology ; Epithelial Cells/cytology/virology ; In Situ Nick-End Labeling ; Intestines/cytology/virology ; Leukocytes/cytology/virology ; Lymphoid Tissue/cytology/virology ; Macrophages ; Microscopy, Electron, Transmission

A molecular study of intestinal samples from 21 broiler flocks with a history of enteritis revealed that 23.8% and 14.3% were positive for chicken astrovirus (CAstV) and avian rotavirus (ARV), respectively. CAstV and group A ARV were simultaneously detected in only one broiler flock. Birds in this group developed the significant intestinal lesions characterized by frothy contents, paleness, and thin intestinal walls. In this report we present an unusual case of runting stunting syndrome (RSS) with a history of high mortality and growth retardation in broiler chickens. We also make the first identification of CAstV and group A ARV in broiler chickens in Korea.
Animals ; Astroviridae Infections/diagnosis/epidemiology/*veterinary/virology ; Avastrovirus/classification/*genetics/isolation & purification/metabolism ; *Chickens/growth & development ; Enteritis/diagnosis/pathology/veterinary/virology ; Intestines/pathology/virology ; Molecular Sequence Data ; Phylogeny ; Poultry Diseases/*diagnosis/epidemiology/virology ; Republic of Korea/epidemiology ; Rotavirus/classification/*genetics/isolation & purification/metabolism ; Rotavirus Infections/diagnosis/epidemiology/*veterinary/virology

OBJECTIVETo investigate the role of immunodeficiency and intestinal mixed infection on inducing extraintestinal dissemination of rotavirus (RV).

METHODSImmunodeficiency was induced in healthy Kunming mice by introperitoneal injection of cyclophosphamide, and RV was administered either orally or via intraperitoneal injection. In another group, toxigenic E. coli and human RV were given sequentially by intragastric administration to induce mixed infection. Three days later the organs of the mice were taken for pathological examination, and RV was detected by in situ PCR and hybridization. In children with or without viremia of rotavirus, blood tests for levels of tumor necrosis factor alpha (TNF-alpha), interleukin-2 (IL-2) and 7 trace elements (zinc, iron, copper, lead, calcium, manganese, and magnesium) were performed.

RESULTSIn immunodeficient mice, pathological changes were found in the small intestinal villus, gastric lamina propria and the cardiac cells of mice taking RV orally, and the mice with intraperitoneal RV injection showed additional liver and kidney pathologies. In mice with mixed infections, pathological changes occurred in the intestines, livers and kidneys. In situ hybridization detected RV in the intestinal villus of immunodeficient mice with oral RV administration, and in the intestinal villus and kidneys of the mice with mixed infections. In situ PCR revealed the presence of RV in the intestinal villus, intestinal gland cells, epithelial cells of the proximal convoluted tubules and collecting tubes in the kidneys of immunodeficient mice taking RV orally, in the intestinal villus, kidneys, livers, hearts and pancreases of those with RV injection, and in the intestines, kidneys, and livers of the mice with mixed infection. Children with rotavirus viremia had TNF-alpha level in comparison with those free of rotavirus viremia, and the majority of the former children showed disorder in trace elements.

CONCLUSIONImmunodeficiency, mixed infection and malnutrition can be important factors contributing to or exacerbating RV infection and extraintestinal RV dissemination.

Animals ; Cyclophosphamide ; administration & dosage ; toxicity ; DNA, Viral ; genetics ; Enzyme-Linked Immunosorbent Assay ; Female ; Immunocompromised Host ; drug effects ; immunology ; Interleukin-2 ; blood ; Intestines ; pathology ; virology ; Kidney ; pathology ; virology ; Liver ; pathology ; virology ; Male ; Mice ; Myocardium ; pathology ; Polymerase Chain Reaction ; Rotavirus ; genetics ; immunology ; Rotavirus Infections ; blood ; immunology ; virology ; Trace Elements ; blood ; Tumor Necrosis Factor-alpha ; blood