Presence Of Porcine Epidemic Diarrhea Virus Research Articles

Coinfection of porcine deltacoronavirus and porcine epidemic diarrhea virus increases disease severity, cell trophism and earlier upregulation of IFN-\u03b1 and IL12

Porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) cause an enteric disease characterized by diarrhea clinically indistinguishable. Both viruses are simultaneously detected in clinical cases, but a study involving the co-infection has not been reported. The study was therefore conducted to investigate the disease severity following a co-infection with PEDV and PDCoV. In the study, 4-day-old pigs were orally inoculated with PEDV and PDCoV, either alone or in combination. Following challenge, fecal score was monitored on a daily basis. Fecal swabs were collected and assayed for the presence of viruses. Three pigs per group were necropsied at 3 and 5 days post inoculation (dpi). Microscopic lesions and villous height to crypt depth (VH:CD) ratio, together with the presence of PEDV and PDCoV antigens, were evaluated in small intestinal tissues. Expressions of interferon alpha (IFN-α) and interleukin 12 (IL12) were investigated in small intestinal mucosa. The findings indicated that coinoculation increased the disease severity, demonstrated by significantly prolonged fecal score and virus shedding and decreasing VH:CD ratio in the jejunum compared with pigs inoculated with either PEDV or PDCoV alone. Notably, in single-inoculated groups, PEDV and PDCoV antigens were detected only in villous enterocytes wile in the coinoculated group, PDCoV antigen was detected in both villous enterocytes and crypts. IFN-α and IL12 were significantly up-regulated in coinoculated groups in comparison with single-inoculated groups. In conclusion, co-infection with PEDV and PDCoV exacerbate clinical signs and have a synergetic on the regulatory effect inflammatory cytokines compared to a single infection with either virus.

Novel Porphyrin Zr Metal-Organic Framework (PCN-224)-Based Ultrastable Electrochemiluminescence System for PEDV Sensing.

The sensitive detection of coronavirus is of vital importance for the prevention of its rapid spread. Porcine epidemic diarrhea virus (PEDV) is a highly contagious coronavirus that causes severe diarrhea and death in neonatal piglets. In this work, a novel PCN-224-based electrochemiluminescence (ECL) system was constructed for PEDV detection with high sensitivity. We found that PCN-224 can be employed as an ECL reporter with a strong signal because of its zirconium-based organic porous frame nanomaterial with a large specific surface area and stable structure. TiO2 nanoparticles were used as an accelerator for the first time to promote the reduction of coreactant potassium peroxydisulfate on the cathode; thus, the initial ECL signal of PCN-224 was significantly amplified. In the presence of PEDV, the ECL signal decreased due to the block effect to electron transfer. As a result, the novel "signal off" biosensor achieved a sensitive detection of PEDV ranging from 1 pg/mL to 10 ng/mL, with a detection limit of 0.4 pg/mL (S/N = 3). Importantly, the PCN-224 nanomaterial enriched the ECL system in biological analysis, and the proposed strategy provided a new route for coronavirus detection.

Endemic course of epidemic diarrhea of pigs in the stabilized focus of infection

Porcine epidemic diarrhea virus (PEDV) has been circulating in Ukraine since 2014 and induces an especially dangerous viral infection with a lethal diarrheal syndrome in newborn piglets, with the initial appearance at the focus of infection. The number of infected cases and lethality among diseased piglets of 1–5 days of age can reach 100%, which together with the forced anti-epizootic measures brings significant economic losses. PED can spread to all pigs, but the emergent quality of infectious pathology appears in newborn piglets. No effective and biologically safe means of specific antiviral prophylaxis, which substantially halts the epizootic process is registered, and etiopathogenetic therapy is not developed, therefore PED is an emergent infection which is difficult tocontrol. Over time there appear stationary foci of infection, where evolutionary changes in relationships in the host-parasite system take place fairly rapidly, since pigs are prolific and fast maturing animals able to replace each generation up to three times each year. This leads to a significant variability in interpopulation relationships and the induction of biodiversity in the molecular mechanisms of adaptation and processing of the viral genome. Clinically, genetic modifications of local variants of PEDV – populations are manifested in the form of changes in epizootic peculiarities in the course of infectious pathology in different age groups of animals. Modifications of PEDV may be accompanied by a slight weakening of the intensity of the infectious process, a decrease in mortality and a decrease in the severity of the pathogenesis of diarrheal syndrome. At the same time, the age range of severe abdominal lesions expands from newborn piglets to fattening animals of older age groups of 28, 32, 70 days. Using a set of measures to combat the PED, including “reverse feeding” recycled infected biomaterial from convalescent pigs, eradication of the pathogen from the environment of the host macroorganisms through a total disinfection regime and strict compliance with veterinary and sanitary rules of animal husbandry provide temporary positive results, but in theory this approach is incorrect, since contamination of animals leads to the dispersal of the virus and the formation of endemic foci of infection. The persistence of the virus in convalescent organisms is not fixed, the external inanimate environment can only be a mechanical factor in transmission of the pathogen preserving the viability of PEDV over time. Stabilization of the epizootic foci of infection is possible due to three factors: a) dissemination of the virus in “reverse feeding”; b) preservation of the virus in the external environment as a result of poor-quality disinfection; c) occurrence of a non-immune element among the convalescent young gilts, who as a result of juvenile insufficiency of the immune system have a low titer accumulation of colostral antibodies to the virus received in the biomaterial through reverse feeding. Due to the lack of “lactogenic immunity”, neonatal pigs as biological indicators for the presence of PEDV in the environment begin reproducing the virus in the enterocytes and develop a typical diarrheal syndrome PED.

Application of reverse transcription polymerase chain reaction to detect porcine epidemic diarrhea virus in Vero cell culture.

Porcine epidemic diarrhea (PED) is a contagious diarrheal disease of swine. The disease is very similar to transmissible gastroenteritis (TGE), with high mortality in swine of all ages and high morbidity in neonates. 3,5 PED virus (PEDV), a coronavirus, was identified in 1978 as the etiologic agent of the disease. 4 PEDV is unable to grow in porcine cell cultures permissive to TGE virus. A method to propagate PEDV in Vero cells was described in 10 years after the first report of PED. 1 However, the high cost and prolonged time required to isolate and propagate PEDV in Vero cells have propelled the search for other diagnostic tests. Virus isolation has important implications in the diagnosis, epidemiology, and control of disease. The development of new techniques for the rapid identification of PEDV adaptation in Vero cells would greatly enhance PEDV detection. The objective of the present study was to describe the application of the reverse transcription polymerase chain reaction (RTPCR) technique to detect PEDV in Vero cell culture. Cell growth medium consisted of minimal essential medium (MEM) buffered with 20 mM HEPES and 0.2% (w/v) bicarbonate, supplemented with 5% (v/v) fetal bovine serum and antibiotics (10,000 IU/ml and penicillin, 10 mg/ml dihydrostreptomycin, 5 mg/ml neomycin, 10,000 IU/ml polymyxin). Virus infection medium consisted of MEM with 30 mM HEPES, a 1% (v/v) 0.3 M NaOH, 0.3% (w/v) tryptose phosphate broth, b 10 mg/ml trypsin (1:250), and antibiotics. Forty-one piglets from 35 farms were used to isolate PEDV. The presence of PEDV in the intestinal tissue of each of the pigs was confirmed by direct immunofluorescence antibody test using an anti-PEDV‐fluorescein isothiocyanate conjugate. c The mucosa and the content of the small intestine were collected and pooled, diluted 1:5 in phosphate-buffered saline (0.01 M, pH 7.2), ground by homogenization, and centrifuged for 20 minutes at 9,000 3 g. Before inoculation, the cell growth medium of monolayered Vero cells grown in 25-cm 2 flasks was removed, and the monolayers were washed twice with cell growth medium. The cells were inoculated with 1 ml of the homogenate per flask. After adsorption in the dark for 2 hours at room temperature, virus infection medium was added (5 ml/flask) without removing the virus inoculum. Because trypsin is thermolabile, 80% of virus infection medium was changed daily. Inoculated cell cultures were checked microscopically for cytopathic effects (CPE) daily. If the cell layer did not show CPE after 4 days of incubation, cells and supernatant fluids were frozen and thawed 3 times to release intracellular virus