Detection of transmissible gastroenteritis virus in feces from pigs by reversed passive hemagglutination

A reversed passive hemagglutination (RPHA) method was developed for the detection of transmissible gastroenteritis (TGE) virus in the fecal specimens from pigs. Ovine erythrocytes fixed with glutaraldehyde and treated with tannic acid were coated with anti-TGE virus swine antibodies, which were purified by affinity chromatographic technique linked with purified TGE virus. The RPHA test was done by the Microtiter method. Erythrocytes coated with purified specific antibodies were agglutinated by TGE virus, but not by porcine rotavirus or porcine enterovirus. The reaction was specifically inhibited by antiserum against TGE virus, confirming the specificity of the reaction. A litter of seven 3-day-old pigs was orally inoculated with TGE virus, and fecal specimens were obtained once a day and serum was obtained every 4th day. With the RPHA test, TGE virus was detected in the diarrheal feces; all of the inoculated pigs developed virus-neutralization antibody for the TGE virus. The RPHA test detected TGE virus in feces from pigs with naturally occurring diarrhea. The RPHA test detected TGE virus in 5 of 6 fecal specimens (80%), whereas the positive rate was only 50% (3/6) for the immunofluorescent staining of primary cultures of porcine kidney cells inoculated with the specimens. The advantages of the RPHA method are simplicity, high sensitivity, and rapid to do.     

Pathology of adenoviral infection in turkeys (Meleagris gallopavo) with respiratory disease and colisepticemia.

Nuclear inclusion bodies typical of the adenovirus group were widespread in in the spleen and other tissues of 8-week-old turkeys with severe respiratory disease and concomitant evidence of colisepticemia. Adenoviral virions were seen in affected nuclei of splenic tissue and in negatively stained preparations of ground spleen. In splenic tissue, inclusions were most prominent in reticular cells and macrophages in the periarterial lymphoid sheaths, the red pulp and the marginal zones of the periarteriolar reticular sheaths. Marked reticuloendothelial hyperplasia, lymphoid atrophy and granulocytic splenitis characterized the splenic changes. There were inclusions in the respiratory tract, intestinal tract, liver, kidney and pancreas. Inoculation of young turkeys, especially when immunosuppressed, resulted in evidence of infection and respiratory disease. The viruses produced cytopathic changes in primary turkey kidney cell cultures but did not affect embryonating chicken eggs. Concentrated viral suspensions induced precipitin lines in agar gel immunodiffusion tests with known antisera against known turkey adenoviruses but did not show an antigenic relationship to chicken adenoviruses.     

R factor types found in Salmonella typhimurium and Escherichia coli isolated from calves in a confined environment.

Typing of R factors by genetic properties was done with Salmonella typhimurium and Escherichia coli isolated from calves on a feedlot where epizootics of clinical or subclinical calf salmonellosis had repeatedly occurred during 5 years. Forty-nine R factors from S typhimurium were fi- (no fertility inhibition) and spp- (no restriction against phage lambda vir). Twenty-three (46.9%) of them belonged to compatibility group Ialpha and the remainder were nontypable. Fourteen R factors from E coli belonged to different genetic types: fi+ (11=78.6%) and fi- (3=21.4%); spp+ (1=7.1%) and spp- (13=92.9%); compatibility groups FII (5=35.7%), N (1=7.1%), and nontypable (8=57.2%). In contrast to the R factors of S typhimurium, 9 (64.3%) of the 14 R factors of E coli carried resistance against aminobenzyl penicillin with or without kanamycin resistance. The compatibility groups of R factors of S typhimurium seemed to be useful as a subsidiary epizootiologic marker in this feedlot.