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Biomedical subjects

L D Olson

Publications and source records attributed to L D Olson.

142 records · Page 8Linked to original sources
PubMedDate not supplied

A microtiter agglutination test for anti-Pasteurella multocida antibodies in turkeys.

A microtiter agglutination test (MTA) was developed for assaying anti-Pasteurella multocida antibodies in turkeys vaccinated with live avirulent Clemson University (CU) strain. Safranine-O was incorporated with the decapsulated P. multocida antigen and greaterly enhanced the visibility of the sedimented free antigen, which formed a compact red button on the bottom of the well. The advantages of the MTA test over the tube agglutination test were that: 1) less antigen and serum were required; 2) delineation of the end point was improved by staining the antigen with safranine-O; and 3) less labor was required.

Agglutination Tests↗
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Ophthalmia in turkeys infected with Pasteurella multocida.

Blepharoconjunctivitis and hypopyon were observed in eyes of turkeys infected during 2 epornitics of fowl cholera. Blepharoconjunctivitis, hypopyon, anterior synechiae, and panophthalmitis were observed sporadically in turkeys experimentally exposed to Pasteurella multocida via drinking water. P. multocida was isolated from these lesions.

Animals↗
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Aerosol transmission of Pasteurella multocida in turkeys.

In three incidents, uninoculated turkeys separated from Pasteurella multocida-inoculated turkeys died of fowl cholera; it was inferred that the pathogen was transmitted by aerosol through the circulating air. Uninoculated and inoculated turkeys were separated by a solid partition and wire netting, and were handled separately. Turkeys were inoculated with a highly virulent strain of P. multocida, which induced the pulmonary form of fowl cholera. In four of the five uninoculated turkeys that died, pneumonia was the principal lesion. In two of these turkeys, which were bled one day before death while still alert, the plasma corticosterone concentration had increased markedly.

Aerosols↗
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Effects of high and low environmental temperatures on clinical course of fowl cholera in turkeys.

Turkeys inoculated with Pasteurella multocida either in the palatine air spaces or via drinking water were maintained t high (33.4-37.4 C), low (2.6-5.3 C), and moderate (19.8-22.4 C) temperatures in temperature-controlled chambers to determine the influence environmental temperature had on the pathogenesis of fowl cholera. In inoculated turkeys maintained at high temperatures, there was a delay in the onset of depression and, in most instances, in mortality in relation to those at low or moderate temperatures. In turkeys inoculated via drinking water and maintained at low temperatures, there was a higher mortality than in those at high or moderate temperatures. In turkeys maintained at low temperatures during the preinoculation period, the onset of depression was accelerated more after inoculation than in those maintained at moderate temperatures before inoculation. The percentage of leukocytes in the hematocrit was higher in turkeys inoculated int he palatine air spaces and maintained at low temperatures than in turkeys similarly inoculated but maintained at high or moderate temperatures. Cloacal temperatures were higher in all inoculated turkeys maintained at high temperatures than in those at low or moderate temperatures, and decreased markedly when turkeys became moribund. In turkeys inoculated in the palatine air spaces, deaths from pneumonia occurred more frequently at low temperatures and torticollis occurred more frequently at high temperatures than at the other temperatures.

Administration, Oral↗
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Plasma corticosterone concentrations in turkeys inoculated with Pasteurella multocida and maintained at high and low environmental temperatures.

Radioimmunoassay was used to determine plasma corticosterone concentration (PCC) in turkeys inoculated with Pasteurella multocida via either the palatine air spaces or the drinking water and maintained at high (33.4-37.4 C), low (2.6-5.3 C) and moderate )19.8-22.4 C) temperatures in temperature-controlled chambers. In uninoculated turkeys maintained at high temperatures, the PCC was generally lower than in turkeys maintained at moderate temperatures, whereas the opposite occurred in turkeys maintained at low temperatures. After inoculation with P. multocida, all groups of inoculated turkeys showed an increase in the average PCC, which attained a level in some turkeys of over 40 ng/ml, in relation to the average in the uninoculated turkeys, which ranged from 1.8 to 27.3 ng/ml. This increase was proportional to the severity of the infection that developed. The PCC was found to be a sensitive indicator of an incubating infection of P. multocida, since it was markedly increased in turkeys that were bled one day before the onset of depression. In turkeys that were inoculated via the palatine air spaces and maintained at 20 C, the PCC on the day of inoculation was significantly (P less than 0.05) lower in the turkeys that later died than in those that survived. Generally, the PCC was higher in the turkeys that either died between 5 and 10 days after inoculation or were depressed aa the end of the experiment on day 10, relative to the turkeys that were alert at the end of the experiment.

Administration, Oral↗
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Influence of Pasteurella multocida and high and low environmental temperatures on adrenals and bursa of Fabricius in turkeys.

The morphologic changes in the adrenals and bursa of Fabricius were evaluated from turkeys inoculated with Pasteurella multocida either in the palatine air spaces or via drinking water and maintained at high (33.4-37.4 C), low (2.6-5.3 C), and moderate (19.8-22.4 C) temperatures in temperature-controlled chambers. There was a slight hyperplasia of the adrenal cortical cells and a hypertrophy of the nuclei in the uninoculated turkeys maintained at both high and low temperatures, but these changes were more marked in turkeys maintained at low temperatures. Regardless of the temperature to which the turkeys were exposed, there was an increase in adrenal weight, hyperplasia of the cortical cells, hypertrophy of the nuclei of the cortical cells, and depletion of lipid in the cortical cells in the turkeys that became depressed after inoculation with P. multocida. In the uninoculated turkeys exposed to high temperatures there was a reduction in the weight of the bursa of Fabricius, atrophy of the follicles, and a reduction in the number of lymphocytes within the follicle, which did not occur in the bursae from uninoculated turkeys maintained at low temperatures. In the turkeys inoculated with P. multocida, there was a marked reduction in bursal weight, atrophy of the follicles, and reduction in the number of lymphocytes within the follicles.

Adrenal Glands↗
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Consumptive coagulopathy in turkeys exposed to Pasteurella multocida.

When turkeys were inoculated intramuscularly with live Pasteurella multocida, three of the four inoculated turkeys developed an increase in modified Russell's viper venom time (mRVVT) 24 hours after inoculation. This increase was followed by irregular decreases and increases in mRVVT at subsequent bleedings. When turkeys were inoculated intravenously with P. multocida, the mRVVT increased markedly after inoculation in all eight inoculated turkeys: 9 hours later, the average mRVVT was significantly (P < 0.05) higher than that of the uninoculated turkeys. No microthrombi were observed in the blood vessels of the liver, spleen, kidneys, or lungs. An increase in mRVVT was interpreted as an excessive consumption of one or more of clotting factors X, V, II, and I. These results indicate that consumptive coagulopathy could be a factor in the pathogenesis of fowl cholera in turkeys.

Animals↗
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IgA, IgG, and anti-Pasteurella multocida antibody levels in bursectomized and/or cyclophosphamide-treated turkeys after CU vaccination.

In bursectomized, cyclophosphamide-treated, and bursectomized/cyclophosphamide-treated turkeys, IgA, IgG, and anti-Pasteurella multocida were determined before and after vaccination with the Clemson University (CU) strain of P. multocida. Before vaccination, the average total serum level of IgA was significantly (P < 0.05) lower in bursectomized and bursectomized/cyclophosphamide-treated turkeys than in untreated controls, and the average serum levels of anti-P. multocida were significantly (P < 0.05) lower in bursectomized, cyclophosphamide-treated, and bursectomized/cyclophosphamide-treated turkeys than in untreated controls. After vaccination, average serum IgA levels were still significantly (P < 0.05) lower in all treated groups of turkeys than in the untreated controls. Also after vaccination, total IgG increased significantly (P < 0.05) only in the bursectomized turkeys, and serum anti-P. multocida antibody levels increased significantly (P < 0.05) in cyclophosphamide-treated, bursectomized/cyclophosphamide-treated, and untreated turkeys. After challenge with virulent P. multocida, survivability was significantly (P < 0.05) lower in the three treated groups of turkeys than in the untreated groups.

Animals↗
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Comparison of low-level rofenaid, low-level chlortetracycline, and vaccination with commercial bacterin for preventing pulmonary form of fowl cholera in turkeys.

The pulmonary form of experimentally induced fowl cholera was controlled effectively either by Rofenaid, a potentiated sulfadimethoxine, at 0.01% in feed, chlortetracycline at 0.0055% in feed, vaccination with a commercial fowl cholera bacterin and a combination of Rofenaid and vaccination. The medicated or/and vaccinated turkeys had a significantly (P less than 0.05) better livability than the unmedicated or unvaccinated exposed turkeys. Turkeys were exposed by contact with carriers and administration of Pasteurella multocida in drinking water. Transmission from carriers to recipients through the water was demonstrated. P. multocida was isolated from the mouths of recipient turkeys receiving low-level medication one week after carriers were introduced.

Animals↗
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Evaluation of two avirulent vaccines for preventing experimental fowl cholera in turkeys, and use of one vaccine in the field.

The Clemson University (CU) strain of live cholera vaccine administered in water (LCVW) was effective in immunizing turkeys against the pulmonary, arthritic, and cranial forms of fowl cholera. The Missouri strain of LCVW immunized turkeys against the pulmonary and septicemic forms of fowl cholera. Pasteurella multocida was isolated from the orifice of the auditory tube of 5% of the turkeys vaccinated with the CU strain 2 weeks postvaccination, but not 4 weeks after challenge. Mortality was not increased by administering the CU strain of LCVW at 5, 10, 20, and 40 x the standard dose of 4 x 10(8) P. multocida. A low concentration of Rofenaid (providing 0.01% potentiated sulfadimethoxine) had no perceptible effect on the development of immunity with the CU vaccine.

Administration, Oral↗
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Inexpensive collapsible covered pen with slatted floor for turkeys.

Designed to confine turkeys for fowl cholera research was a collapsible pen with a hinged steel roof, wire sides, and slatted wooden floors. It is inexpensive to build; conserves labor in feeding, watering, and disposal of manure; protects against rain, sun, and predators; provides ventilation against heat; gives easy access to turkeys; and is collapsible

Animals↗
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Comparison of live avirulent PM-1 and CU fowl cholera vaccines in turkeys.

The live avirulent PM-1 Pasteurella multocida vaccine, grown in brain-heart infusion broth, was evaluated and compared in two experiments with the Clemson University (CU) vaccine, which had been shown to be effective in preventing fowl cholera in turkeys. Experiment 1 was performed during warm environmental temperatures and Expt. 2 during cooler environmental temperatures. The PM-1 vaccine was comparable with the CU vaccine in protecting turkeys against challenge with virulent P. multocida but was considered no less virulent than the CU because turkeys died after vaccination with both the PM-1 and the CU vaccines. A significantly (P < 0.05) higher percentage of unvaccinated turkeys challenged during the cooler environmental temperatures died than did unvaccinated turkeys challenged during the warmer temperatures. A microtiter agglutination test demonstrated a significant (P < 0.01) correlation between the level of serum anti-P. multocida antibody found 1 wk after vaccination and survival after challenge with virulent P. multocida in Expt. 1 and a significant (P < 0.05) correlation between these parameters in Expt. 2. However, there was a significant (P < 0.01) negative correlation between serum anti-P. multocida antibody titer 1 wk after vaccination and body weight gained 4 wk after vaccination, but before challenge, in Expt. 1, suggesting that vaccination with the live vaccines may have had a negative effect on body weight gain. At 4 wk after challenge or 8 wk after vaccination in Expt. 2, there was also a highly significant (P < 0.001) negative correlation between these parameters in the surviving turkeys.

Administration, Oral↗
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Differentiating turkey postvaccination isolants of Pasteurella multocida using arbitrarily primed polymerase chain reaction.

The chromosomal DNA of 29 field isolants of Pasteurella multocida from commercial turkey farms in Missouri and the avirulent Clemson University (CU) and M-9 vaccine strains of P. multocida were tested using the arbitrarily primed polymerase chain reaction (AP-PCR) in combination with 32P-labeled deoxycytidine triphosphate (dCTP) and high-resolution gel electrophoresis. The 29 field isolants of P. multocida were isolated from outbreaks of fowl cholera in turkey flocks in which vaccination with the CU vaccine had been performed within 2 weeks of the isolation, and it was suspected that the outbreak could have been due to the use of the live CU vaccine. The results of this study showed that: 1) the use of the live CU vaccine can lead to the isolation of the vaccine strain if the outbreak occurs within 2 weeks of vaccination; 2) a higher proportion of field isolants collected during 1983 and 1984, when the usage of the CU vaccine strain was highest on Missouri turkey farms, had PCR-amplified product profiles similar or identical to those of the CU vaccine strain compared with the period between 1987 and 1992, when its use was less; and 3) there was no relationship between the PCR-amplified product profiles and the serotype.

Animals↗
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Scanning electron microscopic view of auditory tonsil in turkey.

The auditory tonsil of the turkey was studied by scanning electron microscopy. It is a sizable mass of lymphatic tissue dorsal to the infundibular opening in the auditory tube. The infundibular opening is in the roof of the turkey's mouth, caudal to the nasal cleft, and is the external orifice of the auditory tube that connects with the air spaces of the pneumonic bones in the head. Folds of the auditory tonsil that project toward or into the infundibular opening contained numerous lymphatic nodules in their lamina propria. The epithelial surface of the folds was covered with ciliated and nonciliated columnar cells, goblet cells with microvilli, and ductal openings of mucous glands located in the area. The lymphoid nodules were either oval or round and consisted of a thick reticular network that contained lymphocytes, fibroblasts, and erythrocytes. From some of the lymphatic nodules, there were sinusoids that contained lymphocytes and extended to the epithelial surface, whereas from others there was a lymphocytic infiltration of the surrounding lamina propria.

Animals↗