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In the years 1980-1984, one paramyxovirus type 4 and 11 influenza viruses were isolated from cloacal swabs collected from migratory waterfowls in Fed. Rep. Germany. One influenza virus of H4N8 subtype was isolated from swabs of commercial ducks collected at an abbatoir. Seven of 10 influenza strains, isolated from mallard ducks and coot were identified as a mixture of 2-3 strains of H1, H4, and H5 subtype; 3 virus strains from the same locality relate antigenically to subtype H4 with enzyme serologically identical with N2--Singapore/57 as demonstrated by means of polyclonal and monoclonal antibody.

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The effect of rotavirus and enterotoxigenic Escherichia coli, administered in different sequences, on alkaline and acid phosphatase, leucinaminopeptidase, beta-galactosidase, and succinicdehydrogenase of the intestinal mucosa of cesarian-derived, colostrum-deprived calves was investigated. Decrease in enzyme activity was most prominent in dual infections; it also occurred in parts of the small intestine in monoinfected animals. Increases in enzyme activity involved totally either one or all tissue compartments (crypt, basal villus area, villus tips). Increased activity was present in enteric mucosae that were either not affected or were only slightly affected by rotavirus or enterotoxigenic E. coli. We interpret the increase in enzyme activity as an adaptation of the enteric mucosa to maintain the absorptive function.

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The effect of rotaviruses and enterotoxigenic Escherichia coli administered in various sequences to cesarean-derived, colostrum-deprived calves was studied using light and electron microscopy. The structure of the lymphoid tissue in the ileum, the number of mitoses in the crypts, number of intraepithelial lymphocytes, and enzyme histochemistry (alkaline phosphatase, acid phosphatase, succinic dehydrogenase, beta-galactosidase, and leucinaminopeptidase) of the ileal dome epithelium were evaluated. The area of lymphoid follicles in Peyer's patches of the ileum was investigated morphometrically. Monoinfections with either rotavirus or enterotoxigenic E. coli induced a significant increase in lymphoid follicle area, but did not affect dome epithelial cells. Dual infections did not consistently affect the follicle area, but the number of intraepithelial lymphocytes and the mitotic indices exceeded those of comparable monoinfections. Changes in activity of enzymes in the ileal dome epithelial area were minor.

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Infectious diarrhea in piglets can be caused by TGE, EVD and rota virus. The present report shows another viral agent (para-rota virus) to be present. In addition the report describes light and electronmicroscopic findings of the enteric mucosa caused by the agents mentioned. The degree and distribution of villous atrophy, one of the main histological findings, of infections with TGE, EVD, rota and para-rota virus is compared. A correlation of the results obtained with fluorescent antibody staining and ultrastructural diagnosis of agents was done. An application of the latter seems advisable in case of negative FA staining results.

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Rotavirus-specific antibodies were detected in fetal bovine serum, bovine serum albumin, and human serum albumin by radioimmunoprecipitation with the NCDV strain of bovine rotavirus as the detecting antigen. Fetal bovine sera neutralized bovine rotavirus in a plaque reduction neutralization test to titers of 1:20 or greater. Immunoglobulins purified from fetal bovine serum by protein A-agarose affinity chromatography precipitated rotavirus antigens but did not neutralize bovine rotavirus. Rotavirus antibodies in fetal bovine serum and in purified serum albumin preparations may interfere with diagnostic assays for the detection of rotavirus antigens or antibodies.

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The objective of this international collaborative study was to compare recent swine isolates of influenza viruses and determine whether significant antigenic differences among isolates from different areas of the world could be detected. H1N1 viruses isolated from pigs, birds and humans in 12 different countries were compared in haemagglutination-inhibition assays with post-infection ferret sera and monoclonal antibodies to H1N1 strains. Using A/NJ/8/76 as the reference strain, we found that recent swine isolates from Hong Kong, Italy, Japan, and the USA possess a haemagglutinin virtually indistinguishable from that of viruses typically associated with pigs, i.e., A/NJ/8/76. In contrast, recent swine isolates from several European countries (Belgium, Denmark, France, Federal Republic of Germany, and Spain) were distinguishable from A/NJ/8/76, as demonstrated by tests in the various laboratories. These studies suggest that the H1N1 viruses in pigs are antigenically heterogeneous and that the circulation of particular variants is associated with the geographical location of the animals. These results raise the question of whether these viruses originated from the same source, i.e., pigs, and have undergone antigenic drift or, alternatively, were introduced from other hosts, such as birds.

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The hemagglutinin (HA) gene of the influenza virus subtype H1N1 isolated from pigs and birds has been analyzed by the hybridization technique. According to the RNase protection data the HA genes of recent isolates from pigs in Northern Europe are genetically more closely related to those of isolates from birds in Europe and North America than to those of isolates from pigs in the United States, Taiwan, and Italy. Thus, two different H1N1 subtypes are circulating in the pig population. The results are consistent with the view that H1N1 viruses can be transmitted from birds to pigs and/or vice versa.

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A semi-quantitative analysis of hybrid formation between restriction enzyme-generated subgenomic fragments of cloned cDNA prepared from RNA of foot-and-mouth disease virus (FMDV) strain O1K and radiolabelled RNA from bovine enterovirus, bovine rhinovirus or Mengo virus indicated that the hybrids were of oligonucleotide size. They were located in those parts of the FMDV O1K genome that code for the two capsid proteins VP3 and VP1 and the precursor protein P52 as well as at the 3' end. No hybridization was observed with poliovirus type 1 RNA.

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After a short introduction into the mechanisms of nonspecific defence in the intestine, a brief review on specific, local intestinal immunity is given. Results of experiments on local and humoral antibody production carried out in five caesarian-derived, colostrum-deprived calves are presented. In each of the calves, two jejunal fistulas were prepared, and samples from fistulas and faeces were taken for antigen and antibody determinations at intervals for up to 120 days post infection. Antibodies in the jejunum appeared between 3 and 12 days and in faeces 4 to 18 days post infection. Antibodies could be detected in the faeces for 25 to 58 days. Reinfection of these calves after 50 to 70 days p. inf. usually resulted in a secondary response; however, excretion of the virus was not observed after reinfection.

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The protective effect of a combined rotavirus/enterotoxigenic E. coli K99 vaccine against naturally occurring neonatal diarrhoea was evaluated in two dairy and two beef herds. Before vaccination, frequency of diarrhoea in these herds was 46% up to 60% with losses of 7% to 20%. After vaccination of pregnant cows and heifers mild diarrhoea occurred in 14% to 20% of their calves, one out of 144 calves died with enteric symptoms. In 13 out of 26 calves of nonvaccinated controls where diarrhoea was noted, one of them died. K99-positive enterotoxigenic E. coli were not detected in any of the faeces tested. Rotavirus was found in one of the beef herds.

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