Please use this identifier to cite or link to this item:
Effect of Lelystad virus on various macrophages in pig
Peyer's patch 及肺門淋巴結之巨噬細胞的顯微變化，以瞭解此病毒對豬
Abstract The aim of this study was to understand the pathogenesis of PRRS virus. Three groups of 3-, 21-, and 28-day-old specific pathogen free pigs were inoculated intranasally with 105 TCID50 PRRS virus. The 3-day-old group was sacrificed 3 days later. The 21- and 28-day-old pigs were sacrificed 10 days later. The clinical signs, gross and histopathological lesions were observed. The effect of PRRS virus on the macrophages of various organs, including monocytes, lung macrophages, Kupffer's cells, spleen reticular cells, mesangial cells, microglia cells, Peyer's patch and macrophages in the lung lymph node, were examined detailedly by electron microscopy. Besides, virus isolation and immunostaining were performed to prove that the inoculations were successful. Bacterial contamination was ruled out by bacterial isolation. In order to understand whether the PRRS virus can exacerbate secondary infection, pseudorabies virus and Salmonella cholerasuis were inoculated after PRRS virus infection and the clinical signs and pathological lesions were observed. The results showed that the pigs did not show anorexia, depression, tachypnea and abdominal respiration after PRRS virus inoculation. Two 21-day-old pigs developed polyserositis, and mild consolidation was observed in other pigs' lungs. Hemorrhage was observed in the lung lymph node of 21- and 28-day-old pigs. No visible gross lesion was found in the viscera of 3-day-old pigs. In histopathologic examination, it was observed in all inoculated pigs that the alveolar wall was thickened and the lung parenchyma was infiltrated by lymphocytes. Peripheral hemorrhage in lung lymph node was found in 21- and 28-day-old pigs. In the pigs which got polyserositis, the serosa of various organs, including heart, liver, spleen, lung, intestine and adrenal gland, were infiltrated by lymphocytes and neutrophils. Two 3-day-old pigs had focal hemorrhage in the epicardium and urinary bladder respectively. Ultrastructural examination of the thickened alveolar wall revealed that most cells were endothelial cells, blood cells, fibroblasts and type II pneumocytes. In experiments of dual infection, no difference in the morbidity, mortality and histopathological lesion was seen between salmonella-inoculated and salmonella-PRRSV co- infected pigs. The result indicated that PRRS virus did not exacerbate the secondary infection of salmonella. However, dual infection of PRRS virus and pseudorabies virus showed higher morbidity and more severe histopathological lesion. According to the results, it could be concluded that PRRS virus only caused a mild effect on pig's lymphatic tissues except peripheral hemorrhage was observed in the lung lymph node. However, PRRS virus did exacerbate the secondary infection of pseudorabies virus, but didn't exacerbate the secondary infection of salmonella. Therefore, it is worth to pay attention about the viral secondary infection in PRRS virus infected pigs.
|Appears in Collections:||獸醫學系所|
Show full item record
TAIR Related Article
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.