![]() ![]() The exchange of RNA segments between viruses could lead to molecular diversity and evolution of viruses with increased virulence and host range ( 13, 14). Most orthoreoviruses are recognized to cause respiratory infections, gastroenteritis, hepatitis, myocarditis, and central nervous system disease in humans, animals, and birds ( 11) orthoreovirus genomes are prone to genetic reassortment and intragenic rearrangement ( 11, 12). Orthoreoviruses with 10 discrete RNA segments have been isolated from a wide variety of animal species, including bats, civet cats, birds, reptiles, pigs, and humans ( 10, 11). The family Reoviridae comprises 15 genera of double-stranded RNA (dsRNA) viruses ( 9). We have also reproduced severe diarrhea and acute gastroenteritis in neonatal pigs experimentally infected with purified MRV3 strains. In our efforts to understand the seemingly uncontrollable porcine epidemic diarrhea outbreaks, we discovered a novel mammalian orthoreovirus type 3 (MRV3) in feces of pigs from these outbreaks and ring-dried swine blood meal (RDSB). In June 2014, the USDA issued a federal order to report, monitor, and control swine enteric coronavirus disease (SECD) ( 8). Repeated outbreaks have also been reported on the same farms that were previously infected with PEDV. Department of Agriculture (USDA) conditionally licensed vaccines against PEDV, the outbreaks continue and have now spread to many other countries, including Mexico, Peru, Dominican Republic, Canada, Columbia, and Ecuador in the Americas ( 6) and Ukraine ( 7). However, despite intensive biosecurity measures adopted to prevent the spread of SECoV in many farms and the use of two U.S. Enteric viruses, such as swine enteric coronaviruses (SECoVs), porcine epidemic diarrhea virus (PEDV), and porcine deltacoronavirus (PDCoV), were isolated from these outbreaks ( 3, 4) and characterized ( 5). The mortality can reach up to 100% in piglets less than 10 days of age, with a recorded loss of at least 8 million neonatal pigs since 2013 ( 1, 2). In May 2013, a devastating outbreak of epidemic diarrhea in young piglets commenced in swine farms of the United States, causing immense economic concerns. ![]() The role of MRV3 in the current outbreaks of porcine epidemic diarrhea in the United States remains to be determined, but the pathogenic nature of the virus warrants further investigations on its epidemiology and prevalence. Therefore, the novel porcine MRV3 may contribute to enteric disease along with other swine enteric viruses. Neonatal piglets experimentally infected with these viruses or a chloroform extract of swine blood meal developed severe diarrhea and acute gastroenteritis with 100% mortality within 3 days postinfection. NextGen sequencing of ultrapurified viruses indicated a strong homology of the S1 segment to mammalian and bat MRV3. Biological characterization of two representative isolates revealed trypsin resistance and thermostability at 90☌. Several MRV3 isolates were obtained from chloroform-extracted pig feces or blood meal in cell cultures or developing chicken embryos. MRV3 could not be isolated from healthy or pigs that had recovered from epidemic diarrhea from four states. Here we report the isolation and characterization of a novel mammalian orthoreovirus 3 (MRV3) from diarrheic feces of piglets from these outbreaks in three states and ring-dried swine blood meal from multiple sources. The disease has been reported from at least 32 states of the United States and other countries, including Mexico, Peru, Dominican Republic, Canada, Columbia, Ecuador, and Ukraine, with repeated outbreaks in previously infected herds. Two different swine enteric coronaviruses (porcine epidemic diarrhea virus and Delta coronavirus) have been isolated from the affected swine population. swine industry, causing immense economic losses. Since May 2013, outbreaks of porcine epidemic diarrhea have devastated the U.S.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |