An indirect porcine epidemic diarrhea (PED) virus (PEDV) enzyme-linked immunosorbent assay (ELISA) was compared with the serum neutralization (SN) test by testing 46 samples from experimentally infected sows, 73 samples from naive sows, and 1, 024 field sow samples from 48 commercial swine farms of undefined PED status. The SN test and the ELISA were performed using PEDV, KPEDV-9 strain. Viral proteins as a coating antigen of PEDV ELISA were extracted from the cytoplasm of PEDV-infected Vero cells using a non-ionic detergent, Triton X-100, and a simple protocol of PEDV ELISA was followed. The presence of antibodies in these experimental samples was confirmed by SN and ELISA in which the sensitivity of the ELISA was 89.1%, and the corresponding specificity was 94.5%. On testing 1, 024 field samples, an overall agreement of 84.2% was generated between the SN and ELISA. This study demonstrates that the PEDV ELISA is a useful serodiagnostic screening test at herd level for detecting swine antibodies against PEDV.
Animals ; Antibodies, Viral/blood ; Coronavirus Infections/diagnosis/*veterinary/virology ; Diarrhea/diagnosis/*veterinary ; Enzyme-Linked Immunosorbent Assay/veterinary ; Female ; Neutralization Tests/veterinary ; Sensitivity and Specificity ; Swine ; Swine Diseases/diagnosis/*virology

The deltacoronavirus is a new member of the subfamily Coronaviridae of the family Coronaviridae. Deltacoronaviruses can infect birds and mammals. Deltacoronaviruses were detected in early 2007 in Asian leopard cats and Chinese ferret badgers. In 2014, porcine deltacoronavirus (PDCoV) infection spread rapidly in the USA. Moreover, cell culture-adapted PDCoV has been obtained from infected piglets. Animal experiments have confirmed that the isolated PDCoV is highly pathogenic and causes severe diarrhea in piglets. Thus, the PDCoV can be considered to be a good model to study the deltacoronavirus. In this review, we discuss the etiology, epidemiology, pathogenicity, culture, and diagnostic methods of the PDCoV.
Animals ; Coronavirus ; classification ; genetics ; isolation & purification ; Coronavirus Infections ; veterinary ; virology ; Diarrhea ; veterinary ; virology ; Phylogeny ; Swine ; Swine Diseases ; virology

Escherichia coli (E. coli) strains were collected from young diarrheic calves in farms and field. Strains that expressed the K99 (F5) antigen were identified by agglutination tests using reference antibodies to K99 antigen and electron microscopy. The K99 antigen from a selected field strain (SAR-14) was heat-extracted and fractionated on a Sepharose CL-4B column. Further purification was carried out by sodium deoxycholate treatment and/or ion-exchange chromatography. Monoclonal antibodies to purified K99 antigen were produced by the hybridoma technique, and a specific clone, NEK99-5.6.12, was selected for propagation in tissue culture. The antibodies, thus obtained, were affinity-purified, characterized and coated onto Giemsastained Cowan-I strain of Staphylococcus aureus (S. aureus). The antibody-coated S. aureus were used in a coagglutination test to detect K99+ E. coli isolated from feces of diarrheic calves. The specificity of the test was validated against reference monoclonal antibodies used in co-agglutination tests, as well as in ELISA. Specificity of the monoclonal antibodies was also tested against various Gram negative bacteria. The developed antibodies specifically detected purified K99 antigen in immunoblots, as well as K99+ E. coli in ELISA and co-agglutination tests. The co-agglutination test was specific and convenient for large-scale screening of K99+ E. coli isolates.
Agglutination Tests/methods/*veterinary ; Animals ; *Animals, Newborn ; Antibodies, Monoclonal/*immunology ; Antigens, Surface/immunology/isolation & purification ; Bacterial Toxins/immunology/isolation & purification ; Cattle ; Cattle Diseases/*immunology/*microbiology ; Chromatography, Gel/veterinary ; Chromatography, Ion Exchange/veterinary ; Chromatography, Liquid/veterinary ; Diarrhea/immunology/*veterinary ; Electrophoresis, Polyacrylamide Gel/veterinary ; Enzyme-Linked Immunosorbent Assay/veterinary ; Escherichia coli/*immunology ; Escherichia coli Infections/immunology/*veterinary ; Immunoblotting/veterinary ; Staphylococcus aureus

Calf diarrhea is a commonly reported disease in young animals, and still a major cause of productivity and economic loss to cattle producers worldwide. In the report of the 2007 National Animal Health Monitoring System for U.S. dairy, half of the deaths among unweaned calves was attributed to diarrhea. Multiple pathogens are known or postulated to cause or contribute to calf diarrhea development. Other factors including both the environment and management practices influence disease severity or outcomes. The multifactorial nature of calf diarrhea makes this disease hard to control effectively in modern cow-calf operations. The purpose of this review is to provide a better understanding of a) the ecology and pathogenesis of well-known and potential bovine enteric pathogens implicated in calf diarrhea, b) describe diagnostic tests used to detect various enteric pathogens along with their pros and cons, and c) propose improved intervention strategies for treating calf diarrhea.
Animals ; Cattle ; *Cattle Diseases/diagnosis/drug therapy/microbiology/prevention & control ; Diarrhea/diagnosis/microbiology/prevention & control/*veterinary

The worldwide use of antimicrobials in different fields has created enormous pressure for the selection of resistance among opportunistic bacterial pathogen. One hundred four E. coli isolates were collected and identified from swine with diarrhea in Korea during the period of 2002. The isolates showed highly resistant to streptomycin (99. 0%), tetracycline (97. 1%), neomycin (91. 3%)and carbenicillin (84. 6%)in antimicrobial susceptibility test. Moreover, all of the isolates showed multiple antimicrobial resistant to more than 3, and 85%of them were resistant to more than 7 of total 14 antimicrobial agents. In comparison with isolates in 1998, resistance to antimicrobials was more frequent among the isolates in 2002. Presence of class 1 integrons was investigated through amplification of the gene with PCR, and could be classified 8 groups by pattern of 4 different amplicons. Class 1 integrons were observed in 67 strains (64. 2%)of E. coli from swine in Korea. One and 1. 6 kbp of amplicons were revealed to contain aadA1 and aadB-aadA1 gene cassettes respectively. Two kbp of amplicon had three different gene cassettes, dhfrXII-orfF-aadA2, and 3. 0 kbp of amplicon includes aadB-cmlA1 gene cassettes.
Animals ; Anti-Bacterial Agents ; Diarrhea/microbiology/veterinary ; Drug Resistance, Multiple, Bacterial/*genetics ; Escherichia coli/*drug effects/genetics ; Escherichia coli Infections/microbiology/*veterinary ; Integrons/*genetics ; Swine ; Swine Diseases/*microbiology

Porcine epidemic diarrhea (PED) is a major disease of pigs that inflicts heavy losses on the global pig industry. The etiologic agent is the porcine epidemic diarrhea virus (PEDV), which is assigned to the genus Alphacoronavirus in the family Coronaviridae. This review consists of five parts, the first of which provides a brief introduction to PEDV and its epidemiology. Part two outlines the passive immunity in new born piglets and the important role of colostrum, while the third part summarizes the characteristics of the immune systems of pregnant sows, discusses the concept of the "gut-mammary gland-secretory IgA(sIgA) axis" and the possible underpinning mechanisms, and proposes issues to be addressed when designing a PEDV live vaccine. The final two parts summarizes the advances in the R&D of PEDV vaccines and prospects future perspectives on prevention and control of PEDV, respectively.
Animals ; Antibodies, Viral ; Coronavirus Infections/veterinary* ; Female ; Immunization ; Porcine epidemic diarrhea virus ; Pregnancy ; Swine ; Swine Diseases/prevention & control* ; Viral Vaccines

Porcine epidemic diarrhea (PED) is a highly contagious disease that causes high mortality in suckling piglets. Although several licensed inactivated and live attenuated vaccines were widely used, the infection rate remains high due to unsatisfactory protective efficacy. In this study, mRNA vaccine candidates against PED were prepared, and their immunogenicity was evaluated in mice and pregnant sows. The mRNA PED vaccine based on heterodimer of viral receptor binding region (RBD) showed good immunogenicity. It elicited robust humoral and cellular immune responses in mice, and the neutralizing antibody titer reached 1:300 after a single vaccination. Furthermore, it induced neutralizing antibody level similar to that of the inactivated vaccine in pregnant sows. This study developed a new design of PED vaccine based on the mRNA-RBD strategy and demonstrated the potential for clinical application.
Pregnancy ; Swine ; Animals ; Female ; Mice ; Antibodies, Viral ; Swine Diseases/epidemiology* ; Viral Vaccines/genetics* ; Antibodies, Neutralizing ; Vaccines, Attenuated ; Diarrhea/veterinary*

Early weaned piglets suffer from oxidative stress and enteral infection, which usually results in gut microbial dysbiosis, serve diarrhea, and even death. Rice bran oil (RBO), a polyphenol-enriched by-product of rice processing, has been shown to have antioxidant and anti-inflammatory properties both in vivo and in vitro. Here, we ascertained the proper RBO supplementation level, and subsequently determined its effects on lipopolysaccharide (LPS)-induced intestinal dysfunction in weaned piglets. A total of 168 piglets were randomly allocated into four groups of seven replicates (42 piglets each group, (21±1) d of age, body weight (7.60±0.04) kg, and half males and half females) and were given basal diet (Ctrl) or basal diet supplemented with 0.01% (mass fraction) RBO (RBO1), 0.02% RBO (RBO2), or 0.03% RBO (RBO3) for 21 d. Then, seven piglets from the Ctrl and the RBO were treated with LPS (100 μg/kg body weight (BW)) as LPS group and RBO+LPS group, respectively. Meanwhile, seven piglets from the Ctrl were treated with the saline vehicle (Ctrl group). Four hours later, all treated piglets were sacrificed for taking samples of plasma, jejunum tissues, and feces. The results showed that 0.02% was the optimal dose of dietary RBO supplementation based on diarrhea, average daily gain, and average daily feed intake indices in early weaning piglets. Furthermore, RBO protected piglets against LPS-induced jejunal epithelium damage, which was indicated by the increases in villus height, villus height/crypt depth ratio, and Claudin-1 levels, as well as a decreased level of jejunal epithelium apoptosis. RBO also improved the antioxidant ability of LPS-challenged piglets, which was indicated by the elevated concentrations of catalase and superoxide dismutase, and increased total antioxidant capacity, as well as the decreased concentrations of diamine oxidase and malondialdehyde in plasma. Meanwhile, RBO improved the immune function of LPS-challenged weaned piglets, which was indicated by elevated immunoglobulin A (IgA), IgM, β‍‍-defensin-1, and lysozyme levels in the plasma. In addition, RBO supplementation improved the LPS challenge-induced dysbiosis of gut microbiota. Particularly, the indices of antioxidant capacity, intestinal damage, and immunity were significantly associated with the RBO-regulated gut microbiota. These findings suggested that 0.02% RBO is a suitable dose to protect against LPS-induced intestinal damage, oxidative stress, and jejunal microbiota dysbiosis in early weaned piglets.
Male ; Female ; Swine ; Animals ; Lipopolysaccharides/toxicity* ; Antioxidants/pharmacology* ; Rice Bran Oil ; Dysbiosis ; Dietary Supplements ; Diarrhea/veterinary* ; Weaning ; Body Weight

The prevalence of Lawsonia intracellularis, Brachyspira hyodysenteriae and Salmonella spp. were investigated by multiplex PCR using fecal samples of pigs with diarrhea or a history of diarrhea. The overall herd prevalence of L. intracellularis, B. hyodysenteriae and Salmonella spp. were 46.5%, 37.2% and 51.1%, respectively. Also, the prevalence of L. intracellularis, B. hyodysenteriae and Salmonella spp. among all sampled pigs were 19.9%, 10.8% and 17.7%, respectively. Seventeen of 43 herds were positive with 2 enteric organisms, and 2 herds were positive with L. intracellularis, B. hyodysenteriae and Salmonella spp. simultaneously. It was notable that 11 of 12 herds with more than 2, 000 pigs were affected with Salmonella spp., and that only 2 of 12 the herds were affected with B. hyodysenteriae. This study suggested that herds positive for L. intracellularis, B. hyodysenteriae and Salmonella spp. were distributed throughout Korea, although the relationship among other pathogens such as viral or parasitic ones and/or with metabolic disorders was not determined.
Animals ; DNA, Bacterial/isolation&purification ; Desulfovibrionaceae Infections/epidemiology/microbiology/*veterinary ; Diarrhea/microbiology/veterinary ; Korea/epidemiology ; *Lawsonia Bacteria/isolation&purification ; Polymerase Chain Reaction/veterinary ; Prevalence ; *Salmonella/isolation&purification ; Salmonella Infections, Animal/*epidemiology/microbiology ; *Serpulina hyodysenteriae/isolation&purification ; Spirochaetales Infections/epidemiology/microbiology/*veterinary ; Swine ; Swine Diseases/*epidemiology/microbiology

The effect of acupuncture in the treatment of young pigs with induced enteropathogenic Escherichia coli diarrhea was histopathologically evaluated by routine hematoxylin and eosin stain. Thirty two pigs weighed 4-5kg and aged 21days old were used in this study. The animals with diarrhea were treated with traditional acupuncture, or enrofloxacin. In the group treated with traditional acupuncture, acupoint GV1 (Jiaochao) was used and in the group treated with antibiotics, enrofloxacin was injected intramuscularly. Ten pigs were inoculated with E. coli, but were not treated and served as nontreated control group. At postinoculation day 6, all pigs of the acupuncture and antibiotic treated groups recovered from diarrhea. In the ascending and descending colons of the nontreated control group, severe infiltration of inflammatory cells in the lamina propria was observed and in the fundic stomach, destruction of the fundic gland architecture and necrotic lesions were observed, however, in the same sites of the acupuncture and antibiotics treated groups, the mucosae of the colon and stomach were relatively similar to those of the normal group. These results indicate that acupuncture treatment is effective in controlling induced E. coli diarrhea in pigs at its early stage.
Acupuncture ; Animals ; Colon/cytology/microbiology/pathology ; Diarrhea/therapy/*veterinary ; Escherichia coli Infections/therapy/*veterinary ; Gastric Mucosa/cytology/microbiology/pathology ; Intestinal Mucosa/cytology/microbiology/pathology ; Male ; Stomach/cytology/microbiology/pathology ; Swine ; Swine Diseases/*microbiology/therapy