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B L Deyoe

Publications and source records attributed to B L Deyoe.

At least 37 records · Page 2Linked to original sources
PubMed1988

Opsonin-dependent stimulation of bovine neutrophil oxidative metabolism by Brucella abortus.

Nonopsonized Brucella abortus and bacteria treated with fresh antiserum, heat-inactivated antiserum, or normal bovine serum were evaluated for their ability to stimulate production of superoxide anion and myeloperoxidase-mediated iodination by neutrophils from cattle. Brucella abortus opsonized with fresh antiserum or heat-inactivated antiserum stimulated production of approximately 3 nmol of O2-/10(6) neutrophils/30 min. Similarly treated bacteria also stimulated the binding of approximately 4.3 nmol of NaI/10(7) neutrophils/h to protein. Significant (P less than 0.05) production of O2- and iodination activity by neutrophils were not stimulated by nonopsonized bacteria or organisms treated with normal bovine serum. Seemingly, B abortus stimulated oxidative metabolism in bovine neutrophils; however, the stimulation was dependent on the presence of bacterial associated opsonins.

Animals↗
PubMed1988

Histopathologic findings in Brucella abortus-infected, pregnant goats.

Twenty-eight pregnant goats in midgestation were exposed to a bovine pathogenic strain of Brucella abortus to determine the histologic changes associated with infection. Does were necropsied 0 to 7 days or 4 to 6 weeks after delivery of aborted, stillborn, or live, full-term fetuses. Aborted and stillborn fetuses were necropsied within 16 hours of delivery. Selected, paired tissue specimens were collected for histologic and bacteriologic examination. An avidin-biotin-peroxidase complex immunostaining procedure was used to detect Brucella antigen in tissue section. Histologic changes were evident in specimens from infected does and aborted fetuses. Postpartum does had endometritis, lymphoid hyperplasia in lymph nodes and spleen, and lymphocytic mastitis. The most prominent finding in aborted fetuses was an interstitial pneumonia. Lesions in does and fetuses were similar to those described in Brucella-infected cows and fetuses; however, lesions were less consistently observed in goat fetuses than has been observed in bovine fetuses. Brucella antigen was detected by immunoperoxidase staining within the cytoplasm of placental chorioallantoic trophoblastic cells, macrophages, neutrophils, and uterine epithelial cells. Also, stained brucellae were free in placental and fetal vascular lumens and in the interstitium of autolyzed fetal tissues.

Abortion, Veterinary↗
PubMed1988

Distribution of Brucella abortus organisms in calves after conjunctival exposure.

Thirty calves (3 to 4 months old) were exposed conjunctivally to a pathogenic strain of Brucella abortus. Calves were euthanatized and necropsied at postexposure hours 2 and 4, and at postexposure days (PED) 1, 4, 7, 14, 21, 42, and 49. Selected ocular, pharyngeal, and lymphoid tissues were cultured bacteriologically for brucellae to determine organism distribution. Brucella abortus organisms initially localized in the third eyelids, bulbar conjunctivae, and parotid lymph nodes and were detected in these structures until PED 42, 21, and 49 respectively. In calves euthanatized at PED 7, organisms were in other cranial lymph nodes (mandibular and retropharyngeal), and in calves euthanatized at PED 21, organisms were isolated from peripheral lymphoid tissues. Brucellae were not isolated from mesenteric and bronchial lymph nodes and from the spleen until PED 21. The pattern of isolation indicated that conjunctival exposure probably resulted in entrance of brucellae into the host via ocular tissues.

Animals↗
PubMed1987

Vaccination of cattle with chemically modified and unmodified salt-extractable proteins from Brucella abortus.

Beef heifers were vaccinated on Day 0 with either salt-extractable protein (CSP) or chemically modified CSP (dCSP) from Brucella abortus Strain 19 in Freund's complete adjuvant (FCA). Six weeks later, vaccination was repeated, and heifers received either the homologous or heterologous vaccine. Another group of heifers received only FCA and saline. Vaccinations with CSP or dCSP stimulated marked antibody responses to B. abortus, as detected by standard serologic tests, an enzyme-linked immunosorbent assay, or a quantitative fluorometric immunoassay. Twelve percent of the heifers were seropositive by the CARD test 1 year after vaccination. Vaccination stimulated an increased cell-mediated immune response as measured by lymphocyte blast transformation (LBT) to B. abortus antigens. Fifty-six weeks after the initial vaccination, the heifers were challenged intraconjunctivally with 1.9 X 10(7) colony-forming units of B. abortus strain 2308. Sixty to 83% of the heifers aborted in each group and 70-83% of the heifers were culture positive. There were no significant differences (P greater than 0.05) among groups with respect to the number of abortions or the number of culture-positive heifers. Antibody responses increased rapidly within 4 weeks after challenge. Overall, antibody responses were greater for heifers that aborted than for those that did not abort. These differences were significant (P less than 0.05) only as measured by the fluorometric procedure. The LBT responses appeared to be higher for vaccinates than for the control group, but these differences were not significant (P greater than 0.20). There was a significantly lower (P less than 0.05) LBT response to heat-killed B. abortus in those heifers that aborted compared to those that did not.

Abortion, Veterinary↗
PubMed1986

Release of 5'-guanosine monophosphate and adenine by Brucella abortus and their role in the intracellular survival of the bacteria.

Brucella abortus releases two components (fractions 3b and 10) that inhibit the myeloperoxidase-H2O2-halide antibacterial system of bovine neutrophils by inhibiting degranulation. Fractions 3b and 10 were analyzed by high-performance liquid chromatography and thin-layer chromotography and compared with nucleotide and base standards. These investigations indicated that fraction 3b coeluted and comigrated with 5'-guanosine monophosphate (GMP), whereas fraction 10 coeluted and comigrated with adenine. We determined the biologic effects of GMP, adenine, and B. abortus fractions 3b and 10 on neutrophil functions. Iodination activity of neutrophils was inhibited to approximately 65% of control by GMP (0.04 mg/ml) and by fraction 3b (0.04 mg/ml). Iodination was also suppressed to approximately 80% of control by adenine (0.04 mg/ml) and by fraction 10 (0.04 mg/ml). These results suggest that B. abortus produces GMP and adenine and that these substances contribute to the intracellular survival of the bacteria.

Adenine↗
PubMed1986

Identification of Brucella abortus in formalin-fixed, paraffin-embedded tissues of cows, goats, and mice with an avidin-biotin-peroxidase complex immunoenzymatic staining technique.

An avidin-biotin-peroxidase complex immunoenzymatic staining technique was evaluated for light microscopic detection of Brucella organisms in formalin-fixed, paraffin-embedded tissues. Tissues from cows, goats, and mice inoculated with B abortus strain 2308 were examined, using rabbit antiserum to Brucella cell surface protein as primary antibody. Stained organisms were identified histologically in tissue sections containing B abortus, as detected by bacteriologic examination of duplicate nonprocessed tissue samples. Bacillus sp, Corynebacterium pyogenes, Escherichia coli, Listeria monocytogenes, Pasteurella haemolytica, P multocida, Salmonella typhimurium, Staphylococcus sp, and Streptococcus sp did not stain with this system, using anti-Brucella cell surface protein primary antibody, thus indicating specificity for Brucella organisms.

Animals↗
PubMed1986

Experimentally induced Brucella abortus infection in pregnant goats.

Pregnant goats in midgestation (7 to 16 weeks) were conjunctivally exposed to Brucella abortus strain 2308 to evaluate their applicability as an animal model for bovine brucellosis. Brucellae were isolated from uterine fluid and/or placental specimens of 10 of 12 does at parturition. Six of the 10 infected does delivered dead fetuses and 1 of the 10 delivered live, premature twins. Dead fetuses typically contained brucellae in multiple tissues, whereas brucellae generally were not isolated at birth from live kids. After parturition, B abortus was excreted in the milk and uterine fluids of the infected does. At necropsy (6 weeks after parturition), organisms in the doe were primarily in the uterus and in the lymph nodes that drained the mammary glands, uterus, and head. Brucella abortus was most often isolated from the cranial lymph nodes of neonates that had remained with their dam for 6 weeks after parturition. Serum anti-Brucella antibody concentrations were determined by use of standard tube agglutination, mercaptoethanol agglutination, Rivanol plate tests, card tests, complement fixation, hemolysis-in-gel tests, and an enzyme-linked immunosorbent assay. Serologic responses were detected 2 to 3 weeks after exposure and remained detectable until parturition. Antibody titers increased after parturition in does shedding B abortus at parturition. Anti-Brucella antibody was not detected in neonates before colostrum intake. The neonate's postcolostral titers were similar to those in the dam at the time of parturition. Milk anti-Brucella antibody was detected in milk (milk ring test) from infected and noninfected mammary glands.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Effects of challenge dose on the clinical and immune responses of cattle vaccinated with reduced doses of Brucella abortus strain 19.

Fifty-seven pregnant beef heifers that were unvaccinated or previously vaccinated with Brucella abortus S19, at a dose of either 10(9) or 10(10) colony-forming units (CFU), were challenge-exposed intraconjunctivally with virulent B. abortus S2308 at a dose of 9.4 X 10(6) CFU (Experiment 1) or 5.2 X 10(7) CFU (Experiment 2). In Experiment 1, S19 afforded significant protection (P less than 0.01) against challenge exposure in that 8 of 9 unvaccinated heifers, 1 of 11 vaccinated with 10(9) CFU, and 3 of 10 vaccinated with 10(10) CFU aborted or delivered weak, non-viable calves. In Experiment 2, vaccination did not afford significant protection (P greater than 0.05) in that 9 of 9 unvaccinated heifers, 8 of 10 vaccinated with 10(9) CFU, and 8 of 8 vaccinated with 10(10) CFU aborted. Serologic responses to B. abortus were determined by three standard tests, as well as a quantitative fluorometric immunoassay (FIAX) and an enzyme-linked immunosorbent assay. In Experiment 1, the early serologic response, 0-8 weeks after challenge, appeared greater for controls than for vaccinates, but in Experiment 2, the early response, 0-6 weeks after challenge exposure, appeared greater for vaccinates than for controls. The lymphocyte blast transformation assay, using heat-killed B. abortus as an antigen, was performed sequentially after challenge exposure. In general, mean responses were significantly higher (P less than 0.05) for vaccinated than for non-vaccinated heifers. For individual heifers, an association could not be established between the lymphocyte blast transformation assay and the clinical response to challenge exposure.

Abortion, Veterinary↗
PubMed1985

Isolation of components of Brucella abortus responsible for inhibition of function in bovine neutrophils.

The effects of fractions of Brucella abortus strain 2308 on functions of bovine polymorphonuclear neutrophils (PMNs) were examined in vitro. Ingestion of Staphylococcus aureus and reduction of nitroblue tetrazolium dye by bovine PMNs were not inhibited by heat-killed B. abortus. The ability of PMNs to iodinate proteins was significantly inhibited by live or heat-killed B. abortus and supernatant from heat-killed cells but not by washed heat-killed cells. Two inhibitory components isolated from the supernatant by high-performance liquid chromatography were characterized as nucleotide-like substances with molecular weights of less than 1,000. Inhibition of iodination by these components was concentration dependent. These results indicate that one of the mechanisms by which B. abortus may escape intracellular killing by PMNs is through the production of low-molecular-weight components that inhibit the myeloperoxidase-hydrogen peroxide-halide antibacterial system of bovine PMNs.

Animals↗
PubMed1984

Characterization of salt-extractable protein antigens from Brucella abortus by crossed immunoelectrophoresis and isoelectricfocusing.

Salt-extractable protein antigens (CSP) from Brucella abortus strains 19 and 2308 (vaccine and virulent strains, respectively) were analysed by crossed immunoelectrophoresis (CIE) using rabbit antisera to protein antigens and by isoelectricfocusing (IEF) in polyacrylamide gels. The reference immunoelectrophoretic profiles developed for proteins from strain 19 and 2308 of B. abortus contained 20 and 25 immunoprecipitates, respectively. Serum from cows experimentally infected or hyperimmunized with live organisms produced up to 5 immunoprecipitates in CIE with the protein antigens. Absorption of rabbit sera with homologous B. abortus cells reduced, but did not eliminate all of the immunoprecipitates from rabbit sera, suggesting that the majority, but not all of the protein components, are exposed on the surface of the cell. In contrast, antibody to protein antigens in agglutinin-free absorbed serum from infected cattle could still be demonstrated by CIE, even though CIE with protein extracts from whole cells radioiodinated with the cell surface labeling reagent, diazoiodusulfanilic acid, indicated that these antigens may be at or near the surface of the cell. From CIE in heterologous systems we concluded that all proteins present in strain 19 preparations were partially or completely identical to those in strain 2308. The IEF studies paralleled the CIE studies and revealed that the protein profile from strain 2308 was more complex than the profile from strain 19. Major differences between the 2 strains were found in the pH region from 3.9 to 5.0, where strain 2308 exhibited 4 additional protein bands.

Animals↗
PubMed1984

Specific enzyme-linked immunosorbent assay for detection of bovine antibody to Brucella abortus.

Six soluble antigens prepared from Brucella abortus were compared with a salt-extractable protein (CSP) antigen in an enzyme-linked immunosorbent assay for the detection of antibody to B. abortus in cattle sera. Of seven preparations tested, antigens from B. abortus soluble antigen (prepared from an autoclaved cell suspension) and CSP were stable on frozen storage. Enzyme-linked immunosorbent assay with CSP antigen under optimal conditions was from 100- to 700-fold more sensitive than the standard agglutination, card, Rivanol precipitation-plate agglutination, and the complement fixation tests in detecting immunoglobulin G antibody. From a practical point of view, however, using the most stringent criteria for determining an "upper negative" value, the enzyme-linked immunosorbent assay with CSP was at least 12-fold more sensitive than the standard agglutination test and any of the other serological tests. Furthermore, the enzyme-linked immunosorbent assay with CSP was specific for antibody to B. abortus.

Agglutination Tests↗
PubMed1984

Detection of serum antibody to Brucella abortus in cattle by use of a quantitative fluorometric immunoassay.

A quantitative fluorometric immunoassay (FIAX) was adapted for the detection of serum antibodies to Brucella abortus in cattle. Results are expressed in nanograms of immunoglobulin binding the antigen carrier. The FIAX was compared with the standard tube agglutination, Rivanol precipitation, and complement fixation tests, using 285 serum samples from vaccinated, challenged, or control cattle. Linear regression analysis indicated a significant correlation among all four serological tests; the FIAX test correlated best with the Rivanol test. Ninety sera were from vaccinated and nonvaccinated cattle that were challenged with virulent B. abortus 2308. The sensitivity and specificity of each serological test were determined based on culture results from these cattle. The FIAX was the most sensitive of the four serological tests, detecting 79.2% of the culture-positive animals. The FIAX was the least specific, with 15.4% of the culture-negative animals being classified as positive. Eighty-eight sera were from cattle vaccinated with strain 19 but not challenged. All four serological tests had a statistically significant ability to distinguish sera from control and vaccinates on the basis of mean titers. The mean titer of vaccinates was also significantly different from that of challenged animals. Advantages and disadvantages of the FIAX test for bovine brucellosis are discussed.

Animals↗
PubMed1984

Biochemical and biological properties of soluble protein preparations from Brucella abortus.

Soluble salt-extractable protein antigens (CSP) from Brucella abortus may be of potential value as a vaccine and as a diagnostic reagent for the prevention and diagnosis of bovine brucellosis. These protein antigens, excluding protoplasmic proteins, are those present in the matrix of the outer membrane and in the periplasmic space of gram-negative bacteria. Our research deals mainly with the proteins of the periplasmic space and the nonporin proteins of the outer membrane. We have isolated a group of proteins from intact inactivated cells using mild, nondestructive extraction procedures. The proteins thus obtained range in molecular weight from 10 000 to 51 000 daltons as determined under denaturing conditions and from 10 000 to 124 000 daltons under nondenaturing conditions. The isoelectric pH of these proteins range from 3.5 to 10 with numerous bands in the pH 4.5 to 5.5 region, and a few bands in the pH 6 to 10 region. The low pH region also contains those protein bands which can be labeled with the membrane impermeant reagent, diazotized [125I]-iodosulfanilic acid. The soluble protein preparations are antigenic in guinea pigs, rabbits and cattle, and immunogenic in lemmings, guinea pigs and cattle. Cross-reacting protein antigens are present in protein preparations from B. abortus strains 19 and 2308 when tested with heterologous rabbit sera and with sera from vaccinated and experimentally infected cattle. The soluble protein antigens can be rendered more immunogenic by chemical modification of the primary amino groups with acyl anhydrides, especially with dodecanoyl anhydride. Immunization with dodecanoyl--modified proteins resulted in decreased humoral antibody levels (as measured in guinea pigs and cattle) without loss of protective activity, as measured in lemmings. Furthermore, the soluble proteins have proven to be a sensitive, stable and reliable reagent in the enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to Brucella abortus in serum of vaccinated and experimentally infected cattle. Other soluble protein antigen preparations have also been evaluated and compared with strain 19 proteins for immunogenic properties and for use as an ELISA reagent.

Animals↗
PubMed1984

Cellular and humoral responses of Brucella abortus-infected bovine fetuses.

Fifty-nine bovine fetuses naturally and experimentally infected with Brucella abortus were studied. Lymphoid hyperplasia in multiple lymph nodes, lymphoid depletion in the thymic cortex, adrenal cortical hyperplasia, and disseminated inflammatory foci composed mainly of large mononuclear leukocytes were present in infected fetuses. Histopathologic changes in naturally infected fetuses were indistinguishable from those infected fetuses inoculated in utero. Fetuses inoculated with 1.0 X 10(3) to 1.0 X 10(5) colony-forming units of strain 2308 B abortus were aborted on postinoculation day (PID) 7 to 19. Fetuses obtained by PID 9 and 10 had increased immunoglobulin concentrations and antibody. Increased cortisol values were present in fetuses obtained as early as PID 6. The initial fetal inflammatory response was composed of large mononuclear leukocytes. In fetuses obtained by PID 9 to 10, moderate numbers of neutrophils mixed with mononuclear leukocytes were present in the inflammatory foci. This shift in the initial inflammatory reaction coincided with the appearance of agglutinating antibody.

Animals↗
PubMed1982

Antibodies to Brucella abortus in sera from Strain 19 vaccinated and non-vaccinated cows as determined by enzyme linked immunosorbent assay and conventional serologic methods.

The sensitivity of an enzyme linked immunosorbent assay was compared with 4 other serologic methods for detecting antibodies in B. abortus vaccinated and non-vaccinated cows. Antibodies were detected by ELISA in sera from more than 93% of the culture positive cows, however, less than 55% of the infected animals were identified by any other serologic method. Similarly, antibodies were detected in 82% of the culture negative cows by the ELISA method.

Animals↗
PubMed1982

Extraction, separation, and partial characterization of Brucella abortus antigens.

Brucella abortus isolates strain 19 (a vaccinal strain) and 458 (a virulent field isolate) were analyzed for antigenic differences. Whole cell preparations were extracted with detergents, salt solutions, and phenol-acetic acid-water (PAW). Antigens were separated by starch block electrophoresis and sucrose density gradient centrifugation, serotested, and chemically analyzed. Six distinct precipitin lines were observed for the PAW extract against hyperimmune bovine antisera. With sucrose density centrifugation or starch block electrophoresis, antigens were separated into (i) complement-fixing (CF) antigens and (ii) antigens that did not fix complement but formed precipitin bands. Reciprocal CF tests with purified CF antigen could not differentiate between the antigens from either isolate of Brucella.

Animals↗
PubMed1982

Leukocyte migration-inhibition responses of nonvaccinated and vaccinated heifers to experimental infection with Brucella abortus.

The leukocyte migration agarose technique was used to show the leukocyte migration-inhibition responses of nonvaccinated and vaccinated heifers to experimental infection with Brucella abortus. All heifers had increased leukocyte migration inhibition after exposure to B abortus. Nonvaccinated heifers which aborted had the highest responses. The responses of the vaccinated heifers were significantly (P less than 0.01) lower than those of nonvaccinated heifers. None of the vaccinated heifers aborted.

Animals↗