Since June 2017, several outbreaks of a Seneca Valley virus (SVV) USA/GBI29/2015-like strain have emerged in pigs in China. In our study, we successfully isolated the SVV strain CH-GDZQ-2018, confirmed by immunofluorescence and Western blot assays. Phylogenetic and recombinant analyses showed that the USA/GBI29/2015-like CH-GDZQ-2018 strain was the result of recombination between epidemic strains local to Guangdong, showing that SVV has undergone evolution in China.

Adipose-derived stem cells (ADSCs) are multipotent, and can be differentiated into many cell types in vitro. In this study, tissues from pigs were chosen to identify and characterize ADSCs. Primary ADSCs were sub-cultured to passage 28. The surface markers of ADSCs: CD29, CD71, CD73, CD90, and CD166 were detected by reverse-transcription polymerase chain reaction assays and the markers CD29, CD44, CD105, and vimentin were detected by immunofluorescence. Growth curves and the capacity of clone-forming were performed to test the proliferation of ADSCs. Karyotype analysis showed that ADSCs cultured in vitro were genetically stable. To assess the differentiation capacity of the ADSCs, cells were induced to differentiate into osteoblasts, adipocytes, epithelial cells, neural cells, and hepatocyte-like cells. The results suggest that ADSCs from pigs showed similar biological characteristics with those separated from other species, and their multi-lineage differentiation shows potential as an application for cellular therapy in an animal model.

OBJECTIVE To characterize epithelial cells of the small intestine and colon in horses without clinical gastrointestinal abnormalities with an emphasis on the stem cell niche constituents. SAMPLE Mucosal biopsy specimens from small and large intestines obtained from 12 horses euthanized for reasons unrelated to gastrointestinal disease or systemic disease. PROCEDURES Intestinal biopsy specimens were collected by sharp dissection immediately following euthanasia. Specimens were prepared for immunohistochemical, immunofluorescence, and transmission electron microscopic imaging to detect and characterize each epithelial cell type. Antibodies against protein biomarkers for cellular identification were selected on the basis of expression in other mammalian species. RESULTS Intestinal epithelial cell types were identified by means of immunostaining and morphological characterization with transmission electron microscopy. Some differences in biomarker expression and antibody cross-reactivity were identified in equine tissue, compared with other species. However, each known type of mucosal epithelial cell was identified in equine tissue. CONCLUSIONS AND CLINICAL RELEVANCE The methodology used can enhance detection of stem cells and progenitor cells as well as postmitotic cell lineages in equine intestinal tissues. Results may have relevance to regenerative potential of intestinal mucosa and survival in horses with colic.

Objective: To characterize equine muscle tissue– and periosteal tissue–derived cells as mesenchymal stem cells (MSCs) and assess their proliferation capacity and osteogenic potential in comparison with bone marrow– and adipose tissue–derived MSCs. Sample: Tissues from 10 equine cadavers. Procedures: Cells were isolated from left semitendinosus muscle tissue, periosteal tissue from the distomedial aspect of the right tibia, bone marrow aspirates from the fourth and fifth sternebrae, and adipose tissue from the left subcutaneous region. Mesenchymal stem cells were characterized on the basis of morphology, adherence to plastic, trilineage differentiation, and detection of stem cell surface markers via immunofluorescence and flow cytometry. Mesenchymal stem cells were tested for osteogenic potential with osteocalcin gene expression via real-time PCR assay. Mesenchymal stem cell cultures were counted at 24, 48, 72, and 96 hours to determine tissue-specific MSC proliferative capacity. Results: Equine muscle tissue– and periosteal tissue–derived cells were characterized as MSCs on the basis of spindle-shaped morphology, adherence to plastic, trilineage differentiation, presence of CD44 and CD90 cell surface markers, and nearly complete absence of CD45 and CD34 cell surface markers. Muscle tissue–, periosteal tissue–, and adipose tissue–derived MSCs proliferated significantly faster than did bone marrow–derived MSCs at 72 and 96 hours. Conclusions and Clinical Relevance: Equine muscle and periosteum are sources of MSCs. Equine muscle- and periosteal-derived MSCs have osteogenic potential comparable to that of equine adipose- and bone marrow–derived MSCs, which could make them useful for tissue engineering applications in equine medicine.

Encephalomyocarditis virus (EMCV) can infect many host species and cause acute myocarditis and sudden death in preweaned piglets. In this study, an EMCV strain (NJ08) was isolated from newborn pigs with clinical signs on a pig farm in mideastern China. It was identified by indirect immunofluorescence assay and reverse-transcription polymerase chain reaction. Experiments showed that the isolate could cause severe clinical symptoms and pathological changes in mice but no obvious clinical and pathological changes in commercial piglets. Complete genomic sequencing showed that the NJ08 strain was 78.3% to 100% identical with other isolates in regions coding for various proteins. Phylogenetic analysis showed that the NJ08 isolate belonged to subgroup Ia. This study confirmed that an EMCV isolate from pigs could be fatal to mice and provided new epidemiologic data on EMCV in China.

Objective--To evaluate the immunologic response of a killed tachyzoite vaccine against Neospora caninum and its effectiveness in preventing fetal loss associated with experimentally induced neosporosis in sheep. Animals--30 Dorset ewes. Procedure--Ewes were randomly allocated to receive vaccination on days 1 and 60 of the study with a killed N caninum tachyzoite preparation in a commercially available adjuvant or a saline-adjuvant mixture. A ram was placed on pasture with the ewes from days 15 to 60. Blood was collected from ewes before primary and booster vaccinations and prior to experimental challenge with N caninum tachyzoite performed on day 90; sera were assessed via Neospora agglutination (NA) and immunofluorescence antibody (IFA) assays. Blood was collected from lambs before they suckled, and sera were tested for antibodies against N caninum. Results--Of the 14 vaccinated ewes that became pregnant, 12 gave birth to live-born lambs; in contrast, 5 of 11 pregnant control ewes gave birth to live-born lambs. Whereas vaccination improved fetal survival in pregnant ewes challenged with N caninum tachyzoites, it did not appear to have any appreciable effect on transmission of N caninum to offspring, as indicated by results of NA and IFA assays. Conclusions and Clinical Relevance--The N caninum tachyzoite vaccine used in this study appeared to provide protection against fetal loss associated with experimentally induced neosporosis in a high proportion of pregnant ewes.

In a search of viral agents in pulmonary macrophages of horses with chronic pulmonary disease, equine herpesvirus 2 was found to be unique. In 8 of 9 horses with chronic pulmonary disease, antigens of equine herpesvirus 2 were detected by indirect immunofluorescence staining of scattered foamy macrophages immediately after harvesting by bronchoalveolar lavage and fractionation on metrizamide gradients. In a healthy horse, antigens were not found. After 1 week of cultivation of bronchoalveolar lavage cells from a second group of 9 horses with chronic pulmonary disease, viral antigens were detected in 90% of the adherent pulmonary macrophages. In 2 of 3 healthy horses, viral antigens also were found in 90% of the adherent pulmonary macrophages. Antigens of equine herpesvirus 1, equine herpesvirus 4, parainfluenza virus 3, or adenovirus were not detected. Antigens of the 5 investigated viruses also were not detected in lung tissue slices from a third group of 14 horses, 4 healthy; 7 with varying degrees of bronchiolitis, 2 of which also had chronic intestitial pneumonia; 2 with eosinophilic bronchitis; and 1 with pulmonary hemorrhage. The exclusive presence of equine herpesvirus 2 in pulmonary macrophages was confirmed qualitatively by isolation of infective virus by cocultivation. In a fourth group of 12 horses with chronic pulmonary disease, infective virus could be isolated from pulmonary macrophages of 3 horses and from mixed-blood leukocytes of 5 horses. Virus isolations from 2 healthy horses were not successful from pulmonary macrophages, whereas 1 isolation was obtained from mixed-blood leukocytes. Other viruses were not detected by cocultivation.