To provide information about oncogenes for molecular biological studies of tumors in domestic animals, theproto-oncogenes homologous to the c-myc, c-erbB-2, c-ros-1, c-yes-1, v-myc, v-Ki-ras, and v-Ha-ras oncogenes of genomic DNA in cattle, horses, pigs, dogs, cats, and chickens were investigated by Southern blot hybridization. High molecular weight genomic DNA in each of the animals contained proto-oncogenes that had a certain homology with the oncogenes used, but the extent of nucleotide homology of the proto-oncogenes differed in number and molecular weight: ie, 1 or 2 bands at 1.6 to 22.0 kilobase (kb) in the c-myc probe, 1 or 2 bands at 1.1 to 16.0 kb in the c-ros-1 probe, 1 to 3 bands at 0.7 to 23.0 kb in the c-erbB-2 probe, 1 to 4 bands at 0.6 to 18.0 kb in the c-yes-1 probe, 1 to 3 bands at 1.6 to 30.0 kb in the v-myc probe, 1 to 7 bands at 1.0 to 36.0 kb in the v-Ki-ras probe, and 1 to 4 bands at 1.0 to 27.0 kb in the v-Ha-ras probe. Furthermore, signal strength of each band, as determined by autoradiography, was not always the same for each probe in the various animals. Our findings indicate that these proto-oncogenes are well conserved with species specificities in each animal.

The effect of intestinal microflora on digestible energy (DE) value and fiber digestion was studied in single-comb White Leghorn chickens fed a low-fiber diet (experiment 1) or a high-fiber diet with low or adequate metabolizable energy (ME) value (experiment 2). Fecal energy excretion was calculated from the difference between total energy excretion in urinary and fecal droppings and urinary energy excretion, which was estimated from the energy values for individual urinary nitrogenous compounds extracted with Li2CO3. When the birds were fed the low-fiber diet, no differences in growth, DE, or ME were observed between germ-free and conventional environments. Of birds fed the high-fiber diet, growth of those in the conventional environment was similar to that of the birds in the germ-free environment at the adequate ME value, whereas birds in the conventional environment grew faster than the birds in the germ-free environment at the low ME value. Changes in observed dietary ME values of the high-fiber diets, being higher in birds in the conventional environment than in birds in the germ-free environment (experiment 2), were almost entirely accounted for by those in dietary DE values, most of which was contributed by crude fiber digestion. It was concluded, therefore, that by means of fiber digestion, the intestinal microflora may benefit the host bird by supplying extra energy, which would result in growth promotion, particularly when the bird is deficient in energy.

Inclusion of lactose in the diets of chickens has been determined to reduce cecal colonization with Salmonella typhimurium. We hypothesized, therefore, that dietary lactose may be a practical means for reducing the prevalence of Salmonella contamination of chicken products. Because some strains of Salmonella are atypical and ferment lactose, we investigated the effects of dietary lactose on cecal colonization with lactose-fermenting S typhimurium. Broiler chicks were inoculated intracloacally with Lac+ S typhimurium selected for resistance to novobiocin and rifampicin. The chicks also were inoculated orally with certain anaerobes that do not effectively inhibit colonization by S typhimurium, but do appear essential for lactose mediated inhibition of cecal colonization. Control chicks were not given dietary lactose, and chicks in the experimental group were fed a diet containing 7% lactose. Enumeration of Lac+ S typhimurium in cecal contents revealed dietary lactose to be effective at controlling this organism. Control was correlated with changes in cecal pH and increases in undissociated volatile fatty acids, especially propionic acid.

Proteins in sporulated and unsporulated oocysts of Eimeria maxima were characterized, using monoclonal antibodies (MAB), ELISA, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and protein (western) immunoblotting techniques. Three MAB (EM1, EM2, and EM4) were produced against proteins of sporulated oocysts. The ELISA results indicated that EM1 was reactive with sporulated oocyst proteins, EM2 was reactive with sporulated and unsporulated oocyst proteins, and EM4 was reactive with unsporulated oocysts and proteins. Separation of proteins in E maxima sporulated and unsporulated oocysts by SDS-PAGE indicated that sporulated oocysts had proteins of approximately 200 kilodaltons (kD) and distinct protein bands at 21.5 and 45 kD. Using SDS-PAGE, unsporulated oocysts had less-distinct high molecular weight protein bands (> 200 kD), compared with sporulated oocysts, and a distinct protein band at 31 kD. Use of all 3 MAB yielded negative results in western blot analysis of fractions obtained by SDS-PAGE.

Conjunctiva-associated lymphoid tissue (CALT) in the eyelids of chickens was studied by gross, histologic, and electron microscopic techniques. Structural features were characterized at 1 day of age and at posthatching week (PHW) 1, 2, 3, 4, 6, 8, 12, and 16. Beginning at PHW 1, prominent lymphoid nodules containing a heterogenous population of lymphocytes, lymphoblasts, and macrophages were first observed within conjunctival folds and fissures of the lower eyelid. Nodules contained germinal centers by PHW 2 and plasma cells by PHW 4. The epithelium associated with these nodules was flat, had short, irregular microvilli, contained intraepithelial lymphocytes, and lacked goblet cells. High endothelial venules were located at the base of lymphoid nodules and contained lymphocytes within and below the cuboidal endothelium. In the upper eyelid, CALT was morphologically similar to lymphoid tissue in the lower eyelid, but nodules were smaller and more random, lacked association with epithelial folds and fissures, and were clustered around the opening of the nasolacrimal duct. By PHW 12, CALT was characterized by basal germinal centers outlined by collagenous stroma, suprafollicular plasma cells, columnar epithelium with goblet cells, and fewer intraepithelial lymphocytes. On the basis of these features, CALT in chickens has morphologic characteristics similar to other components of the mucosal immune system and, therefore, may have a role in mucosal immunity.

Campylobacter jejuni A74/O and A74/C are congenic strains. An oral dose of 10(5) organisms of strain A74/C colonizes chicken intestines. Strain A74/O, from which A74/C is derived, does not colonize the chicken intestines with an oral dose of 10(5) organisms. In this study, the congenic bacteria were compared to identify possible colonization mechanisms. Differences were not observed in plasmid content or by HindIII, Pst I, Acc I, HincII, Ava I, Ava II, Xba I, and BamHI restriction enzyme digestion of total DNA. Transmission electron microscopy of negatively stained samples revealed no differences between the strains. Sections of cecal tissue from nonfed day-of-hatch chicks were cultured with each strain for 2 hours and then examined by light and electron microscopy. Both strains caused necrosis of villus epithelial cells. Immunofluorescent or silver staining revealed strain A74/C located deep in numerous epithelial crypts, but strain A74/O only was present in one sample mixed with sloughed necrotic cells. Similarly, organisms were detected by transmission electron microscopy deep in crypts in tissues cultured with A74/C, but not A74/O. Cells of A74/C detected in crypts did not appear to associate with epithelial cells. The strains did not differ in chemotactic behavior to mucin or fucose.

Phenotypic characteristics of 12 paired, Salmonella serotypes isolated from healthy and ill chickens were compared. Variables compared included antibiotic resistance profiles, production of colicins and siderophores, mannose-sensitive hemagglutination of erythrocytes, resistance to serum complement, carbon source utilization, presence and transmissibility of R plasmids, and invasiveness in primary chicken kidney cell culture. Differences were found between pairs for utilization of carbon sources, mannose-sensitive hemagglutination of erythrocytes, and invasiveness in cell culture.

An ELISA was developed and tested for its ability to detect antibodies against Salmonella enteritidis in chickens. Various features of the ELISA were evaluated and optimized. The outer membrane protein antigens selected by use of the protein immunoblotting method made the assay specific and sensitive. The assay was evaluated in chickens experimentally infected with S enteritidis. Blood samples collected at weekly intervals after experimental infection with S enteritidis were analyzed by ELISA. Results of the ELISA were compared with those of conventional serum plate and microagglutination tests. The ELISA was more sensitive and specific in the detection of S enteritidis infection than the other 2 conventional tests.

The purpose of this study was to evaluate the effectiveness of an aromatic-dependent mutant of Salmonella typhimurium as a parenteral vaccine for prevention of fecal shedding of Salmonella spp. Pigs and chickens were vaccinated IM, with 1 X 10(9) and 1 X 10(8) organisms, respectively, followed by a second identical vaccination 2 weeks later. Salmonella organisms were not detected by analysis of fecal or cloacal swab specimens from any animal after vaccination. Deleterious side effects were not noticed after vaccination. Pigs were challenge-inoculated PO with 1 X 10(12) virulent S typhimurium 1 week after the second vaccination. Chickens were challenge-inoculated PO with 3 X 10(8) organisms of either S enteritidis or the virulent parent strain of S typhimurium 3 weeks after the second vaccination. Vaccinated pigs shed Salmonella spp significantly less frequently than did nonvaccinated pigs. Vaccinated chickens challenge-inoculated with either S enteritidis or S typhimurium also shed Salmonella less frequently than the corresponding nonvaccinated control birds; however, the difference was not significant.