Pilot study of the effect of acemannan in cats infected with feline immunodeficiency virus.

Acemannan, a complex carbohydrate shown to stimulate interleukin-1, tumor necrosis factor alpha and prostaglandin E2 production by macrophages, has also demonstrated antiviral activity in vitro against human immunodeficiency virus, Newcastle disease virus and influenza virus. A pilot study was undertaken to determine acemannan's effect in 49 feline immunodeficiency virus (FIV) infected cats with clinical signs of disease (Stage 3, 4 or 5), 23 of which had severe lymphopenia. Cats received acemannan either by intravenous (Group 1) or subcutaneous (Group 2) injection once weekly for 12 weeks, or by daily oral (Group 3) administration for 12 weeks. Upon entry into the study, cats were randomly assigned to one of the three groups. Laboratory analyses were performed at the beginning of the study and at Weeks 6 and 12. Cats were allowed to continue with a predetermined maintenance regimen of acemannan after completing the 12-week study. Thirteen cats died during the course of treatment. Upon necropsy, the most frequent histopathologic findings were neoplastic, kidney and pancreatic disease. Friedman's two-way ANOVA test showed no significant differences in efficacy among groups administered acemannan by the different routes. Therefore, groups were combined and a signed-ranks test was used to determine changes over time. A significant increase was seen in lymphocyte counts (P < 0.001). Neutrophil counts decreased significantly (P = 0.007), as did incidence of sepsis (P = 0.008). When cats entering with lymphopenia were analyzed separately, a much greater increase in lymphocyte counts was noted (235%) compared with non-lymphopenic cats (42%). A survival rate of 75% was found for all three groups. Thirty-six of 49 animals are alive 5-19 months post-entry. These results suggest that acemannan therapy may be of significant benefit in FIV-infected cats exhibiting clinical signs of disease.     

A simple technique to differentiate between animals infected with Yersinia enterocolitica IX and those infected with Brucella abortus.

While both Brucella abortus and Yersinia enterocolitica IX have O antigens in common, they differ significantly with respect to motility. Thus Br abortus is always non-motile while Y enterocolitica is motile when grown at room temperature. The presence of yersinia H agglutinins in serum can be shown to be evidence of previous exposure to Y enterocolitica. These agglutinins are not generated by brucella infection. A rapid H agglutination test will serve to provide this differentiation without interference from cross-reacting O antigens.     

Depressed immunoconglutinin responses in calves experimentally infected with Trypanosoma congolense

Contrary to expectation, immunoconglutinin levels failed to rise significantly in calves infected with Trypanosoma congolense. In addition, it was shown that trypanosome infection appeared to inhibit the immunoconglutinin response to Brucella abortus strain 19. The possible reasons for these findings are discussed.     

Studies on the use of Yersinia enterocolitica 09 antigens in rapid quantitative plate tests for the differentiation of Brucella and Yersinia infections in cattle and the diagnosis of bovine brucellosis

The use of the rapid quantitative plate agglutination test (QPAT) utilizing triphenyltetrazolium chloride (TTC) stained antigen for the differentiation of bovine brucellosis and yersiniosis is described. It was found with experimental laboratory animals and cattle, that titres against homologous antigen tended to exceed titres against heterologous antigen and that this reaction together with measurement of the Yersinia OH agglutinin titre could be used for purposes of differentiation. It was, however, not possible to differentiate these infections in serum from cattle with naturally-occurring antibodies. It was also shown that Brucella 0 agglutination in the QPAT was very weak in some sera with high titred anti-Brucella antibodies by serum agglutination, while Yersinia 0 agglutination was not. The QPAT, using Yersinia 0 antigen, therefore correlated well with the results obtained using Brucella 0 antigen in serum agglutination tests. It is suggested that Yersinia 0 antigen may be a suitable antigen for use in rapid agglutination tests because of this relative insusceptibility to false negative results.     

Controlling microbial contamination on beef and lamb meat during processing

SUMMARY The microbiological quality of carcases, meat and environmental surfaces was evaluated in commercial boning rooms processing beef and lamb. There was considerable variation in the level of microbial contamination on both carcases and meat, with counts ranging from less than 20 to 10⁸/cm² on carcases and to 2 times 10⁷/cm² on meat. The level of microbial contamination on meat was influenced by the level of carcase contamination at boning and by the boning process itself. Carcase contamination was the major determinant of microbiological quality, as more than 70% of carcases had microbial counts greater than 10³/cm². Cutting boards were a major source for microbial dissemination during boning, particularly when carcase counts were less than 10³/cm². If carcases were heavily contaminated, the contamination of processing surfaces was irrelevant in determining microbial loads on meat. Where carcase contamination was at low to moderate levels, the contribution of the boning process to the contamination on meat assumed increased significance. Under these conditions, improved sanitation of cutting surfaces in the boning room resulted in a significant reduction in microbial contamination on the surface of meat. These results can form the basis for ensuring that improvements made in carcase management before boning, to improve microbiological quality, will be preserved through attention to cutting board hygiene during boning.     

Free Flying Sparrows as Carriers of Salmonellosis

Salmonella typhimurium was isolated from nine of 60 wild sparrows trapped in the Guelph area. While this organism was isolated from birds trapped at several different locations, the highest prevalence was in sparrows trapped in close proximity to an animal clinic. The significance of these findings in relation to human and animal salmonellosis is discussed.     

Cell-mediated Hypersensitivity to Pasteurella hemolytica in Normal and Cold-stressed Mice

Mice infected with Pasteurella hemolytica developed cell-mediated hypersensitivity manifested by inhibition of macrophage migration but not by delayed skin reactions, to two antigen preparations from this organism. Relative to migration by the cells of uninfected animals, migration by cells from infected animals was inhibited to the same degree whether or not the animals were chilled. However, the cells from infected chilled animals were not able to migrate as far as the cells from normal mice even in the absence of antigen.