Rotavirus replication in colostrum-fed and colostrum-deprived pigs.
A porcine rotavirus isolate was titrated in neonatal colostrum-fed and colostrum-deprived pigs. The stock rotavirus suspension had a titer of 10(-6.5)/ml and was in its fifteenth cell culture passage in MA-104 cells. Fourteen colostrum-fed pigs were orally inoculated with dilutions of the stock virus suspension ranging from undiluted to 10(-5). These pigs did not develop notable clinical signs during the 7-day experimental trial and no pathologic changes were found in intestine, liver, lung, kidney, spleen, or brain. However, rotavirus was detected in feces of the colostrum-fed pigs, using virus isolation and electron microscopic techniques. Rotavirus was also isolated from lung, brain, or spleen of 4 of 12 of these pigs. Sixteen colostrum-deprived pigs were orally inoculated with dilutions of the stock virus suspension ranging from 10(-1) to 10(-8). Diarrhea developed in 10 of 12 pigs that were given up to the 10(-6) dilution. Seven of these 12 pigs died because of the severity of diarrhea. Pigs that died of rotavirus-induced diarrhea had severe villus loss in the jejunum and ileum. Villi of the small intestine of colostrum-deprived pigs that survived the severe diarrhea were within normal limits at the end of the 7-day trial. The colostrum-deprived pigs that were inoculated with a dilution less than 10(-6) and survived past 96 hours underwent seroconversion. Rotavirus was detected by virus isolation and electron microscopy in the feces of all colostrum-deprived pigs that survived beyond 18.5 hours after inoculation. Virus was isolated from lungs, brain, or spleen of 12 of 16 colostrum-deprived pigs.
Shaw
D P
DP
Department of Veterinary Pathology, College of Veterinary Medicine, University of Missouri, Columbia 65211.
Morehouse
L G
LG
Solorzano
R F
RF
D000818:Animals; D000831:Animals, Newborn; D003126:Colostrum / Q000276:immunology*; D003967:Diarrhea / Q000276:immunology / Q000382:microbiology / Q000662:veterinary; D007421:Intestine, Small / Q000473:pathology; D012401:Rotavirus / Q000502:physiology*; D012400:Rotavirus Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000382:microbiology*; D014779:Virus Replication