Biomedical subjects

J R Glisson

Publications and source records attributed to J R Glisson.

At least 19 recordsLinked to original sources

PubMed1992

Factors affecting endotoxin release from the cell surface of avian strains of Pasteurella multocida.

Two avian strains of Pasteurella multocida, a vaccine strain and a virulent field isolate, were investigated to determine their propensity to release endotoxin from the cell surface. Both organisms released comparable amounts of endotoxin when plasma complement proteins were present, however the virulent strain did so without the loss of viability that occurred in the vaccine strain. Blocking complement activity decreased the ability of plasma to elicit endotoxin release from the bacteria. When the cells were treated with divalent metal chelators such as trans-1, 2-diaminocyclohexane-N,N,N1,N1-tetraacetic acid (CDTA), more endotoxin was released from the vaccine strain than from the virulent isolate. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of purified lipopolysaccharide (LPS) from both strains revealed virtually identical patterns. Both had patterns considered typical of rough LPS. Challenge studies in 8 weeks old turkeys showed that the field strain induced endotoxemia of longer duration than the vaccine strain and produced greater mortality.

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PubMed1991

A survey of potential virulence markers from avian strains of Pasteurella multocida.

Twenty-four isolates of Pasteurella multocida from clinical cases of fowl cholera and the Clemson University vaccine strain were surveyed for the presence of potential virulence markers. Membrane proteins, enzymatic activity of the membrane proteins, and carbohydrate fermentation patterns were also determined to demonstrate phenotypic relationships within the groups. Few differences were found in these phenotypic characteristics among the isolates. Almost all the organisms produced siderophore and were hemolytic on turkey red blood cells. No extracellular enzyme or bacteriocin activity was detected and little antibiotic resistance was found. However, many organisms contained plasmids and demonstrated some degree of resistance to complement. Both characteristics were correlative markers in Pasteurella multocida isolated from birds with fowl cholera.

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PubMed1991

Heterophil function in healthy chickens and in chickens with experimentally induced staphylococcal tenosynovitis.

Heterophil function was evaluated in 16 healthy chickens and in 46 chickens with experimentally induced staphylococcal tenosynovitis. In paired blood samples, heterophils from chickens with tenosynovitis had a significant increase in adherence, chemotaxis, phagocytosis, and bacterial killing of Staphylococcus aureus compared to heterophils from healthy chickens. The percent adherence of heterophils to nylon fiber columns increased significantly from a 78.4% mean +/- 6.6% standard deviation to 87.6% +/- 3.2% after induction of staphylococcal tenosynovitis. Heterophil movement following in vitro exposure to saline or endotoxin was increased in chickens with tenosynovitis; 3 +/- 1 heterophils/0.25 mm2 to 10 +/- 6 heterophils/0.25 mm2 and 136 +/- 29 heterophils/0.25 mm2 to 340 +/- 74 heterophils/0.25 mm2, respectively. Endotoxin-activated serum was chemoattractive for heterophils from all chickens. Flow cytometry was used to define the heterophil population on light scatter histograms, evaluate individual cell phagocytosis of latex beads, and quantitate the number of beads phagocytosed per heterophil. When incubated with increased numbers of beads, only heterophils from chickens with tenosynovitis phagocytosed higher numbers of beads. At heterophil to bead ratios of 1:10, the percentage of heterophils that phagocytosed beads increased from baseline values of 37.8% +/- 9.0% to post-infection values of 67.3% +/- 7.5%. Using 1:20 heterophil to bead ratios, heterophil phagocytosis increased from 38.7% +/- 9.9% to post-infection values of 79.8% +/- 7.3%. Heterophils from all chickens were able to phagocytose and kill log phase staphylococcal bacteria. After phagocytosis, the heterophils from chickens with staphylococcal tenosynovitis rapidly decreased the number of viable bacterial colony forming-units per milliliter by approximately one log.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1991

Resistance of Pasteurella multocida A:3,4 to phagocytosis by turkey macrophages and heterophils.

A virulent field isolate and 2 vaccine strains of Pasteurella multocida A:3,4 were compared for resistance to phagocytosis by turkey macrophages and heterophils, using in vitro assays. The least virulent vaccine strain (M-9) was phagocytosed to a greater degree than was the field isolate or the other vaccine strain (Clemson University). All 3 bacteria differed significantly from each other in the amount of capsular material present as measured by polycationic ferritin labeling and electron microscopy. Removal of the capsule with hyaluronidase resulted in a significant increase in phagocytosis of the field isolate.

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PubMed1990

Septicemia in vaccinated and nonvaccinated turkeys inoculated with Pasteurella multocida serotype A:3,4.

Sixty-four, 10-week-old turkeys were inoculated with a highly virulent field isolate (86-1913) of Pasteurella multocida serotype A:3,4 by an oculo-nasal-oral route. Inoculated turkeys were examined at 4, 8, 16, 20, and 24 hours post-inoculation for bacteremia and histologic lesions. Bacteremia was detected in one of six turkeys 8 hours after inoculation and in four of six turkey poults at 16 hours post-inoculation. Pasteurella multocida was isolated from the spleens of two turkeys at 8 hours and from the spleens of all six poults 16 hours after inoculation. Peak concentrations of P. multocida reached 10(9) colony forming units per ml of blood. At 4 to 8 hours post-inoculation, isolate 86-1913 produced a fibrinopurulent bronchopneumonia followed by severe pulmonary necrosis, pleuritis, vasculitis; and, at 16 to 24 hours post-inoculation numerous extracellular bacteria were observed. Hepatic lesions included focal heterophil aggregates 8 hours after inoculation; these progressed to hepatic necrosis. Numerous extracellular bacteria within sinusoids were present 16 to 24 hours after inoculation. At 16 to 24 hours post-inoculation, there was degeneration of periarteriolar reticular cells in the spleen; these cells progressed to coalescing coagulative splenic necrosis with extracellular bacterial colonies. A second group of 41, 10-week-old turkeys, previously vaccinated with the Clemson University strain of P. multocida serotype A:3,4, were challenged with isolate 86-1913.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1990

Disassociation of bactericidal and fungistatic activities from the oxidative burst of avian macrophages.

Avian peritoneal exudate macrophages, when exposed to phagocytic stimuli, produced an appreciable oxidative burst as measured by production of chemiluminescence, superoxide anion, and hydrogen peroxide. Metabolic inhibitors of the oxidative burst and scavengers of oxygen radicals clearly inhibited macrophage chemiluminescence, but had no significant effect on macrophage bactericidal activity against Escherichia coli or fungistatic activity against Candida tropicalis. Therefore, avian macrophages were capable of oxygen-independent bactericidal and fungistatic activities.

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PubMedDate not supplied

Economic impact of a documented case of reovirus infection in broiler breeders.

The following parameters were used to calculate the economic impact to a commercial broiler company of a pathogenic reovirus infection in broiler breeders during egg production: hatchability, selling of eggs, vaccination, mortality, medication, slowing of line speed at processing, and downgrading and trimming at processing. The cost due to reovirus infection in one flock of broiler breeders was approximately $48,000.

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PubMedDate not supplied

Turkey macrophage and heterophil bactericidal activity against Pasteurella multocida.

Bactericidal activity of turkey macrophages and heterophils was demonstrated in an in vitro colorimetric bactericidal assay. Two vaccine strains and one field isolate of Pasteurella multocida A:3,4 and a single isolate each of Escherichia coli and Staphylococcus aureus were compared for susceptibility to the bactericidal activity of turkey macrophages and heterophils. Only P. multocida A:3,4-strain M-9 (the least virulent strain) was susceptible to macrophage bactericidal activity in the absence of specific immune serum, whereas all three P. multocida A:3,4 organisms were killed when opsonized with specific immune serum. E. coli was susceptible to the bactericidal activity of macrophages, and S. aureus was resistant. All bacteria tested were highly sensitive to the bactericidal activity of intact turkey heterophils, regardless of the opsonin treatment. Electron microscopic findings suggested that heterophils may kill extracellular P. multocida. Only S. aureus and E. coli were killed by lysed heterophils.

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PubMedDate not supplied

Spontaneous regression of "dermal squamous cell carcinoma" in young chickens.

Eight young chickens with lesions characteristic of those described as dermal squamous cell carcinoma were obtained before slaughter. Lesions were measured; representative lesions were biopsied and examined microscopically; and gross changes were monitored. Lesions appeared to originate as cystic, keratin-filled proliferations of the feather-follicle epithelium. These cysts progressed into raised, keratin-filled, and eventually ulcerated, nodules. Loss of the keratin core resulted in a shallow ulcer that became progressively flattened and regressed into a fibrous dermal scar. All lesions in the broilers regressed in 4 to 16 days (mean 14 days). Twenty roaster lesions completely regressed. For roasters, the mean time to regression was 20 days, with a range of 6 to 93 days. Although there was limited invasion of the dermis by atypical keratinocytes, the overall architecture and biological behavior were more consistent with a benign lesion.

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PubMedDate not supplied

Poult malabsorption syndrome. I. Malabsorption in poult enteritis.

One-day-old poults were placed on littler on which poults had previously developed diarrhea, increased mortality, and stunting. Small intestines, pancreas, and liver were evaluated histologically. Morphometric evaluations were conducted to determine villous length and crypt depth. Poults were evaluated for malabsorption utilizing D-xylose and lipid absorption tests. Compared with controls, the gastrointestinal tract of affected birds was grossly distended, was fluid-filled, and had thin, flaccid walls on days 5 and 8. Ceca were distended with brown watery fluid and gas on days 5, 8, and 12. No histologic lesions were present in the liver, pancreas, or pancreatic ducts, and only mild inflammatory changes were present in the small intestine. Villous atrophy and crypt hypertrophy were present in the small intestine on days 5, 8, 12, 16, and 21. Morphometry revealed significant decreases in villous lengths and increases in crypt depth throughout the trial. D-Xylose and lipid absorption were significantly decreased on days 8 and 11. Intestinal epithelial damage by infectious agents with subsequent villous atrophy is postulated to have produced malabsorptive diarrhea.

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PubMedDate not supplied

Poult malabsorption syndrome. II. Pathogenesis of skeletal lesions.

One-day-old poults were placed on litter on which poults had previously developed diarrhea, increased mortality, stunting, and malabsorption. Gross, microscopic, and morphometric evaluations of the proximal tibiotarsal growth plate, along with analysis of plasma calcium, phosphorus, and 25-hydroxyvitamin D3 concentrations, were conducted for 3 weeks to determine the development and character of skeletal lesions. Poults developed enteritis with diarrhea and dehydration. Body weights and shank lengths were significantly decreased. Plasma 25-hydroxyvitamin D3 concentrations were significantly decreased. Plasma calcium was significantly decreased on day 8. Plasma phosphorus concentrations were significantly increased on day 8 and were significantly decreased on days 15, 18, and 22. Growth plates narrowed on days 8 and 11 and expanded on days 15, 18, and 22. The proliferating-prehypertrophy zone significantly decreased in length on days 11, 18, and 22, and significantly increased in length on day 15. The unmineralized hypertrophy zone was significantly increased in length on days 15, 18, and 22. The mineralized hypertrophy zone was significantly decreased in length on all days. Skeletal lesions during the poult malabsorption syndrome evolved from an early osteoporotic lesion associated with hypocalcemia to a rachitic lesion associated with depleted vitamin D and hypophosphatemia.

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PubMedDate not supplied

Poult malabsorption syndrome. III. Skeletal lesions in market-age turkeys.

Skeletal deformities, a major contributing factor to economic losses in market-age turkeys, may be associated with the poult malabsorption syndrome. A study was performed to determine whether the naturally occurring malabsorption syndrome produces skeletal lesions in turkeys at market age. Poults were placed on litter on which poults had previously developed malabsorption. Exposed poults developed enteric disease with 21% mortality during the first 3 weeks. Controls had no enteric disease and no mortality. At the end of the study, 20-week-old exposed turkeys weighed 0.621 kg (5%) less than controls and had a higher incidence of angular limb deformities with significantly higher angulation scores. Exposed turkeys also had a greater incidence of rotated tibias and bowed tibias. The mechanical property of tibial shear strength was significantly lower in turkeys that had survived the earlier poult malabsorption syndrome.

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PubMedDate not supplied

In vivo antigen expression by Pasteurella multocida.

Pasteurella multocida was purified from the blood of turkeys affected with acute fowl cholera, and membrane preparations from those bacteria were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and visualized on immunoblots. Antigens were detected in the membranes of these in vivo-propagated bacteria that were not detected in membrane preparations of the same P. multocida strain grown in vitro. The unique antigens were detected in the detergent-insoluble phase and were enriched to various degrees by different detergents.

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PubMedDate not supplied

Skeletal lesions associated with a naturally occurring poult enteritis.

One-day-old poults were placed on contaminated litter on which poults previously had developed an enteric disease characterized by diarrhea, increased mortality, and stunting. These exposed birds were examined for clinical signs and pathologic changes in bone and parathyroid glands compared with controls. Intestinal and fecal samples were examined for potential pathogens. Exposed poults varied in size as early as day 8 and had significantly decreased weight gains and reduced shank lengths on days 8, 12, 16, and 21. The proximal tibial growth plate was narrowed. The mineralized hypertrophy zone was decreased in length and contained multiple non-mineralized bands on days 8, 12, 16, and 21. Metaphyseal trabeculae were reduced in amount on days 16 and 21. Parathyroid glands were hyperplastic on days 16 and 21. The bone and parathyroid gland lesions indicated that mineral homeostasis was being maintained at the expense of the skeleton during the enteric disease. A specific etiology for the enteric disease was not determined. Cryptosporidium, rotavirus, paramyxovirus, and Salmonella were identified in the exposed poults, and paramyxovirus and Salmonella were identified in the controls.

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PubMedDate not supplied

Characterization of Pasteurella multocida mutants of low virulence.

Ten temperature-sensitive mutants of the Clemson University (CU) vaccine strain of Pasteurella multocida have been developed and were characterized by phenotypic attributes such as carbohydrate fermentation, antibiotic resistance, and membrane protein profiles. Some mutants were found to have lost the ability to utilize some substrates, notably xylose and gluconate, whereas others were able to ferment additional carbohydrates such as arabinose and rhamnose. CU was found to be resistant to sulfisoxazole, of intermediate resistance to bacitracin, and sensitive to rifampin; the sensitivity to these three antibiotics varied among the mutant strains, but 60% were resistant to rifampin. Membrane protein profiles demonstrated some changes in major bands, and there was variation in 50% of the mutants in proteins in the 31 kilodalton range. All strains were assayed for the presence of several virulence factors, and many were found to produce siderophore and to exhibit some degree of complement resistance.

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PubMedDate not supplied

Reproducibility of a virus-neutralization test for infectious laryngotracheitis virus.

A virus-neutralization test for infectious laryngotracheitis virus was performed in microtiter plates using standard techniques. To assess the reproducibility of the test, 11 sera were each titrated repeatedly once a week for 8 weeks, and the results were compared to a standard. The standard used for reproducibility was that the 95% logarithmic confidence intervals of the mean calculated from three titrations of the same serum had to be smaller than the logarithmic distance "within" two microtiter plate wells. For the virus neutralization test to give reproducible results, such confidence intervals had to fall "within" two wells at least 75% of the time. Over the 8 weeks, percent reproducibility varied from 43.5% to 81.5%. The infectious laryngotracheitis virus-neutralization test did not meet our defined standard of reproducibility with positive antisera. Results with negative control sera were reproducible, however. Percent reproducibility varied from 31.8% to 93.8% for different sera tested, but it was not related to the titer of the sera.

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PubMedDate not supplied

Differentiation of vaccine strains and Georgia field isolates of infectious laryngotracheitis virus by their restriction endonuclease fragment patterns.

Seven restriction endonucleases (REs) were used to cleave the DNA from seven vaccine strains of infectious laryngotracheitis (ILT) virus and from six Georgia field isolates of ILT virus. After electrophoresis of the resulting RE fragments, the patterns were compared in order to differentiate strains of ILT virus. The six chicken-embryo-origin (CEO) vaccines were identical with each RE, but the tissue-culture-origin (TCO) vaccine strain differed from the CEO vaccines using five of the REs. Four of the six field isolates were identical by each RE, but two field isolates differed from each other and from the four identical field isolates on the basis of patterns produced by some but not all of the REs. The four identical field isolates could not be differentiated from the CEO vaccine strains by any RE, but the other two field isolates were not identical to either strain of vaccine virus. This work demonstrates that differentiable strains of ILT virus exist in the United States and that viruses other than vaccine viruses are involved in field outbreaks of ILT.

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PubMedDate not supplied

Turkey heterophil chemotaxis to Pasteurella multocida (serotype 3,4)-generated chemotactic factors.

The purpose of this study was to determine the ability of three strains or isolates of Pasteurella multocida (serotype 3,4) to generate chemotactic factors for heterophils when exposed to pooled turkey serum. Results indicated that each bacterial strain or isolate (M-9, CU, and 86-1913) was associated with the production of chemotactic factors, but the more pathogenic bacterial isolate (86-1913) elicited greater heterophil migration in chemotaxis studies.

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