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Biomedical subjects

B S Pomeroy

Publications and source records attributed to B S Pomeroy.

At least 19 recordsLinked to original sources

Enzyme-linked immunosorbent assay for the detection of Salmonella enteritidis infection in chickens.

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.

Animals↗

Effects of the evisceration and cooling processes on the incidence of Salmonella in fresh dressed turkeys grown under Salmonella-controlled and uncontrolled environments.

In July and December 1981, turkeys grown in a Salmonella-free environment were sampled at the end of the slaughter and evisceration processes to determine the effect of slaughter and evisceration on the incidence of Salmonella in raw, eviscerated turkeys. A total of 109 eviscerated turkeys from the Salmonella-free flocks and 79 control turkeys were sampled. A total of 75 environmental swab samples and 5 chiller water samples were collected. Less than 1% of the eviscerated Salmonella-free turkeys were Salmonella positive and 6.3% of the eviscerated control turkeys were Salmonella positive. The results of the swab samples indicated generally good processing equipment sanitation.

Abattoirs↗

Effect of ammonia on the quantitative clearance of Escherichia coli from lungs, air sacs, and livers of turkeys aerosol vaccinated against Escherichia coli.

Turkeys were given an aerosol vaccine to determine their ability to clear a virulent inhaled pathogenic strain of Escherichia coli, while they were being maintained in the presence of atmospheric NH3. Turkeys were exposed to 2 concentrations of NH3 (10 and 40 microliters/L of air). More E coli was found in lungs, air sacs, and livers of turkeys exposed to NH3. Turkeys not exposed to NH3 had better clearance of E coli. Vaccination against E coli improved the rate of clearance of E coli in birds not exposed to NH3.

Air Sacs↗

Identification and isolation of somatic pili from pathogenic Escherichia coli of turkeys.

Transmission electron microscopy was performed to identify the presence of somatic pili on Escherichia coli pathogenic to turkeys. Three common pathogenic serotypes of E coli (Ola, O2a, and O78) were used. They were cultured in tryptic soy, veal infusion, and Minca medium broth and were incubated at 37 C with and without CO2 (5%). The cultures were examined for the expression of pili after 24, 48, and 72 hours of incubation. Pili were on all strains of the 3 serotypes examined. These pili were also isolated and purified.

Animals↗

Scanning electron microscopic studies of adverse effects of ammonia on tracheal tissues of turkeys.

Effects of 10 and 40 microliter of NH3/L of air (10 and 40 ppm) on the tracheal tissues of turkeys were examined under the scanning electron microscope. Turkeys maintained in the presence of either level of NH3 had deterioration of their normal mucociliary apparatus after prolonged exposure. Excessive mucous production, matted cilia, and areas of deciliation in the tracheal tissues were detected in birds exposed to NH3 concentrations as low as 10 microliters/L. The tracheal tissues of birds not exposed to NH3 appeared normal. The implications of respiratory tract damage caused by NH3 are discussed.

Ammonia↗

In vitro evaluation of B-lymphocyte function in turkeys infected with hemorrhagic enteritis virus.

Studies were conducted on B-lymphocyte function in turkeys infected with hemorrhagic enteritis (HE) virus. Hemolytic plaque-forming technique was used to detect antibody-forming cells in turkeys. The plaque-forming cell responses in HE virus-infected and noninfected controls were compared. Results of this study indicated a decreased capability of HE virus-infected turkeys to produce antibodies to sheep RBC. The greatest inhibition of antibody-forming cell production was seen in the turkeys 19 days after exposure to the virus. However, after this period, the turkeys gradually recovered their immunocompetence to sheep RBC.

Adenoviridae Infections↗

Leukocyte migration inhibition in chickens inoculated with Salmonella typhimurium.

Leukocyte migration-inhibition tests were conducted in chickens infected with Salmonella typhimurium. A relatively new and simple method that involves the migration of leukocytes under agarose gel was used. Migration distance was projected onto a white background at 40X magnification, using a microprojector. Quantitation of migration was done by measuring the linear distance the cells had moved from the margin of the agarose wells. The details of the technique and the importance of it in studies of cell-mediated immune response are discussed. Chickens inoculated with S typhimurium had a significant leukocyte migration inhibition.

Animals↗

In vitro depression of the mitogenic response of lymphocytes from turkeys infected with hemorrhagic enteritis virus.

A depression in the mitogenic response of lymphocytes was demonstrated in turkeys inoculated with hemorrhagic enteritis virus. Blood samples were collected (in heparin) once a week, beginning 1 week after the turkeys were inoculated. The whole blood assay was used to study lymphoblastogenesis. Concanavalin-A and phytohemagglutinin were the mitogens used: the radioisotope used was (125I)deoxyuridine (125IudR; 125I, sp act 5 Ci/mg). Suppression in the lymphocyte response in vitro was seen up to 5 weeks after the inoculations were done, after which there was a gradual recovery from suppression in the lymphocyte blastogenesis.

Animals↗

Cell-mediated immunity against turkey coronaviral enteritis (bluecomb).

Studies on cell-mediated immune response in turkeys infected with turkey coronavirus (TCV) were made. A whole blood culture technique was developed for quantitatively evaluating in vitro lymphocyte reactivity to mitogens concanavalin A, phytohemagglutinin-P, and TCV antigen. The degree of blastogenesis was quantitated by the measurement of the uptake of the [125I]deoxyuridine in the presence of fluorodeoxyuridine. The stimulation indices were consistently higher in the infected birds compared with those in the noninfected controls, and they were statistically significant (P < 0.05). The detection of TCV specific responses indicated that cell-mediated immunity may be important in determining the immunity against turkey coronaviral enteritis. The whole blood lymphocyte transformation assay was emphasized as a convenient and useful in vitro indicator of cell-mediated immunity in TCV infection.

Animals↗

Immunofluorescent studies on localization of secretory immunoglobulins in the intestines of turkeys recovered from turkey coronaviral enteritis.

The present study concerns the production of specific secretory antibodies in turkeys orally inoculated with turkey coronavirus (TCV). Tissue localization of secretory antibodies in the intestines of recovered birds 4 and 5 months later was demonstrated by immunofluorescence technique. Intestinal sections were stained by sandwich method, using concentrated TCV antigen and anti-TCV conjugate. It was suggested that local synthesis of antibody might be responsible for life-long immunity seen in these birds after recovery from infection.

Animals↗

Secretory antibodies against turkey coronaviral enteritis.

Studies on local immunity to transmissible coronaviral enteritis of turkeys (bluecomb) was made. Intestinal secretions and bile from affected birds contained secretory immunoglobulins against coronaviral antigen throughout the 6 months' duration of the experiment. Attempts to purify and to characterize the globulins in intestinal secretions and bile of the affected birds were made, using the techniques of gel filtration, DEAE chromatography, and immunoelectrophoresis. Class-specific anti-turkey IgA antiserum in the agar gel precipitin test further established the presence of IgA in the intestinal secretions and bile.

Animals↗

Isolation of type A influenza and Newcastle disease viruses from migratory waterfowl in the Mississippi flyway.

Twenty-seven chicken red blood cell agglutinating agents were isolated from 187 tracheal swabbings of apparently healthy migratory mallard ducks (Anas platyrhynchos) in the Mississippi flyway. Twenty-four of the isolants were type A influenza virus; 3 lentogenic Newcastle disease viruses were isolated. Isolations were not made from either 65 giant Canada geese (Branta canadensis) or 60 Franklins' gulls (Larus pipixcan).

Animals↗

Characteristics of two new reticuloendotheliosis virus isolates of turkeys.

Reticuloendotheliosis (RE) virus strains MN81 and MN67 isolated from epiornithics of RE in turkeys were partially characterized. Strains MN81 and MN67 replicated in chicken embryo fibroblast,duck embryo fibroblast and turkey embryo-fibroblast cultures and produced syncytial cytopathic effects in duck embryo fibroblast and turkey embryo fibroblast cultures. The virions of MN81 and MN67 measured approximately 100 nm in diameter, resembled RE virus strain T, and could be distinguished from avian leukosis viruses morphologically. The buoyant density of strain MN81 was found to be 1.15 g/cm3 in sucrose gradients. Strains MN81 and MN67 were inactivated by heat, acid pH, ether, and chloroform treatments. These strains were serologically unrelated to avian leukosis virus but were related to RE virus strains T, CS, DIA, and SN.

Animals↗

Detection of turkey coronaviral enteritis (bluecomb) in field epiornithics, using the direct and indirect fluorescent antibody tests.

In Minnesota, efforts have been made over the past 10 years to eliminate turkey coronaviral enteritis (TCE, bluecomb) by controlled depopulation and decontamination with a rest period before restocking. In 1973, clinical observations indicated that bluecomb was restricted to one limited area in Minnesota. Five epiornithics occurred during late 1973 and 1974, involving 5 different farms in this limited geographic area. During 1975, 3 epiornithics of TCE were investigated, involving 185,000 turkeys in 17 flocks, of which approximately 17,000 died. Naturally infected turkeys representing 7 operations between 1973 and 1976 were examined by both the direct fluorescent antibody test and indirect fluorescent antibody test (IFAT). The direct fluorescent antibody test detected coronaviral antigen in intestinal tissues during the acute phase of the disease, and the IFAT was highly useful in detecting TCE serum antibodies of turkey flocks that had recovered and were potential carriers. Therefore, an IFAT surveillance program was instituted for replacement flocks on farms where clinical epiornithics of TCE had occurred in 1974 through 1976. Operation 5 involved TCE epiornithics over a 2-year period and illustrate the importance of complete depopulation with an intensive decontamination program.

Animals↗

Development of microagglutination test for detecting Arizona hinshawii 7:1,7,8 infection in turkeys.

A microagglutination antigen treated with tetrazolium dye was produced. The culture used was rendered nonmotile by growing in medium containing 1:1,000 concentration of phenol. A trial was conducted by infecting freshly hatched turkey poults with Arizona hinshawii 7:1,7,8. An equal number of poults were kept as negative controls. Starting with 4-week-old poults, blood samples, cloacal swabs, and environmental samples were obtained at 2-week intervals up to 16 weeks of age. The serum samples were tested by using tubeagglutination (TA), serum plate agglutination (SPA), and microagglutination (MA) tests for A hinshawii 7:1,7,8. A field trial was conducted, using known negative and infected turkey flocks, and serum samples were tested by MA, SPA, and TA tests. The results indicated that MA test was far more sensitive and superior to TA and SPA tests in detecting turkeys infected with A hinshawii 7:1,7,8. The field trial confirmed the laboratory trial observations.

Agglutination Tests↗

Susceptibility of turkeys to Georgia strain of Marek's disease virus of chicken origin.

Two experiments were conducted to study the susceptibility of turkeys to Georgia strain of Marek's disease virus (MDV). One-day-old chickens and turkeys were experimentally inoculated with Marek's disease (MD) infective plasma (experiment 1) or tumor homogenate (experiment 2) and raised in isolation for 29 weeks. The MDV inoculums were pathogenic for chickens and turkeys and caused high mortality (chickens, 100% and turkeys, 70%). Macroscopic lesions of MD were observed in liver, spleen, lungs, proventriculus, and other viscereal organs. Microscopically, affected tissues were infiltrated with the pleomorphic population of neoplastic lymphocytes. Uninoculated turkeys did not show gross or microscopic lesion of MD. The MDV was reisolated from the experimentally inoculated, but not from the uninoculated, chickens and turkeys. Antibodies to MDV were detected in experimentally infected chickens. Uninoculated chickens and all turkeys lacked precipitating antibodies to MDV. The present study suggests that turkeys are highly susceptible to experimental infection with GA strain of MDV.

Animals↗