Biomedical subjects

K A Brogden

Publications and source records attributed to K A Brogden.

85 records · Page 5Linked to original sources

PubMed1982

Isolation of 80S ribosomes from spores of Aspergillus fumigatus and their antigenicity in rabbits.

Ribosomes were obtained from spores of Aspergillus fumigatus by mechanical disruption and differential centrifugation. The initial preparation (crude ribosomes) contained spore components which appeared to be broken fragments of plasmalemma with or without organelles. Purified ribosomes free of membranous material were prepared by gel filtration chromatography on Sepharose CL-4B. Monomeric 80S ribosomes consisting of 40% protein and 60% RNA, and morphologically characteristic of fungal ribosomes were isolated. Serological reactions in sera from rabbits with crude or purified ribosomes were similar indicating that the purification process did not change or eliminate antigens that stimulated antibody detectable either by indirect hemagglutination (IHA) or in gel precipitin tests.

Animals↗

PubMed1982

Lysates of turkey-grown Pasteurella multocida: examination of vaccine preparations by electron microscopy.

The effects of differential centrifugation, density gradient centrifugation, freeze-thawing, and chemical lysis on the morphology of Pasteurella multocida from the blood of infected turkeys were examined by electron microscopy. Morphologic differences were not seen between thin-section preparations of P multocida after differential and density gradient centrifugation procedures. The internal ultrastructure of in vivo-grown cells was different from that observed previously for P multocida grown in vitro. Large membranous blebs were also observed on the surface of negative-stained preparations of organisms from the plasma, but not in thin sections of cells from the same preparation. Freeze-thaw of bacterial suspensions in sucrose resulted in partial lysis, revealing bacteria in different phases of degradation. Complete lysis (but not solubilization) was enhanced by treatment with EDTA, lysozyme, and Triton X-100. Centrifuged lysate pellets were thin-sectioned or negative-stained. Pellets consisted of vesicles, ranging in size from 0.05 to 1.0 micrometer, that had a characteristic trilaminar membranous appearance similar to those reported from other gram-negative bacteria grown in vitro and treated similarly.

Animals↗

PubMed1982

Lysates of turkey-grown Pasteurella multocida: partial solubilization of the cross-protection factor(s).

A lysate of turkey-grown Pasteurella multocida was treated to determine the nature of a cross-protection factor (CPF). Complete lysate was treated with proteolytic enzymes and mild heat. Cross protection was not induced with pepsin-treated lysate, but 50% cross protection was induced with trypsin-treated lysate and 100% cross protection was induced in turkeys vaccinated with lysate heated at 56 C for 1 hour. Complete lysate was also fractionated by differential and sucrose density gradient centrifugation. After the lysate was centrifuged for 1 hour at 100,000 x g, the CPF was found in the supernatant and pellet fractions, indicating that the CPF was dispersed throughout; 84% of the lysate protein was in the supernatant and 14.7% of the protein in the pellet. After sucrose density gradient centrifugation, 100% cross protection was induced with the top and bottom gradient fractions and 60% with the middle fraction. Although the differential centrifugation pellet and bottom sucrose gradient fraction had protein that was disproportionately small when compared with the soluble portions of the whole lysate, they had the CPF equal in immunizing capacity.

Animals↗

PubMed1980

Physiological and serological characteristics of 48 Pasteurella multocida cultures from rabbits.

Forty-eight Pasteurella multocida cultures collected from rabbits over a 56-year period were examined to determine their physiological characteristics and to determine their serological types in the gel diffusion precipitin test. Generally, the physiological characteristics from 30 tests were typical for P. multocida. There were a few atypical variations in the fermentation of lactose and maltose and variations in trehalose, dulcitol, xylose, sorbitol, and glycerol. Seven cultures did not produce indole, and four cultures did not produce detectable amounts of hydrogaen sulfide. In obliquely transmitted light, 26 cultures formed large, slightly iridescent, mucoid colonies, 17 cultures had iridescent colonies, and 5 cultures had blue colonies. Heat-stable antigens from the 48 cultures reacted with antisera prepared from P. multocida type cultures presenting serotypes 1, 3, 4, 12, and 15. Antigens from 15 cultures reacted slightly with antisera from more than one serotype. Overall, gel precipitin reactions involving serotype 3 (25%) and serotype 12 (66.7%) were the most prevalent.

Animals↗

PubMed1979

Comparison of Pasteurella multocida serotyping systems.

Thirty-two type specific cultures used in four typing systems for serologically classifying Pasteurella multocida were compared as originally described for: (1) Little and Lyon's plate agglutination test; (2) Carter's indirect hemagglutination test, hyaluronidase decapsulation test, and acriflavine reaction; (3) Namioka's plate and tube agglutination tests; and (4) Heddleston's gel diffusion precipitin test. In addition, seven cultures from Robert's five passive protection groups were included. When reference cultures were examined by the typing system from which they were described, the results generally correlated with those results published. However, serotypes determined by one typing system generally did not correlate with serotypes determined by another system. Cultures of a single serotype in one system often represented more than one serotype in another system. Results indicated that cultures with one or two serotyping antigens in common may differ in other antigens. Because of the antigenic complexity of P multocida and the nature of the antigens involved in each test, a reliable correlation or equality between serotypes determined by different typing systems could not be made.

Agglutination Tests↗

PubMed1978

Serologic examination of the Westphal-type lipopolysaccharides of Pasteurella multocida.

The serologic specificities of the Westphal-type lipopolysaccharides from 16 serotypes of Pasteurella multocida were compared with those reported for the heat-stable typing antigens in the gel diffusion precipitin test. Like the heat-stable typing antigen, the Westphal-type lipopolysaccharide from each of the serotypes reacted only with its homologous antiserum in 14 of the 16 serotypes. The lipopolysaccharide from type strains representing serotypes 2 and 5 reacted with either of the corresponding typing sera, as did field isolates of these serotypes to a lesser extent. Although differences among the properties of these antigens were minor, the lipopolysaccharide appeared to be a major component of the heat-stable antigen responsible for the type specificity.

Cross Reactions↗

PubMedDate not supplied

Ultrastructural location of the cross-protection factor on in vivo and in vitro grown Pasteurella multocida.

Pasteurella multocida from infected turkey tissues expresses a unique immunogen called cross-protection factor (CPF) that induces immunity to challenge by both homologous and heterologous serotypes. In this study, we used a monoclonal antibody (AMP MAb) to CPF and protein A-colloidal gold (PACG) to locate CPF on P. multocida. After incubation with AMP MAb and PACG, CPF was detected at the bacterial surface and cell periphery of P. multocida in infected turkey liver and P. multocida isolated from infected turkey blood. CPF was not detected on P. multocida incubated with control monoclonal antibody. Pasteurella multocida isolated from infected turkey blood and cultivated in the peptone-based medium did not express CPF consistently, and some cells contained more CPF than others. The location of CPF also varied, and CPF was detected both intracellular and extracellular on the cell surface. In the latter cells, CPF was heavily concentrated to a specific lateral site or detected sloughing from the cell surface. These results correlate with laboratory observations that CPF detected on P. multocida from infected turkey tissues, P. multocida isolated from infected turkey blood, and P. multocida cultivated in peptone-based medium is associated with outer membrane fractions.

Animals↗

PubMedDate not supplied

Partial characterization of the hemagglutinin of Alcaligenes faecalis.

The hemagglutinin of Alcaligenes faecalis was partially characterized. Hemagglutination (HA) was blocked by enzymes inactivating proteins, by heat, and by antisera but not by sugar-blocking substances. Pili were not determined to be a factor in HA activity. There was no connection between virulence and HA activity.

Alcaligenes↗

PubMedDate not supplied

A new serotype of Pasteurella multocida associated with fowl cholera.

Gel-diffusion precipitin tests demonstrated an additional Pasteurella multocida serotype, designated serotype 16. Isolate P-2723, antigenically distinct from the other (previously reported) 15 serotypes, was from a turkey affected with fowl cholera. This serotype is not widely distributed. Isolate P-2723 was of mild virulence in turkeys, resulting in local infections in the hock joint and sternal bursa of only 1 of 9 turkeys exposed.

Animals↗

PubMedDate not supplied

Serologic types and physiologic characteristics of 46 avian Pasteurella anatipestifer cultures.

Forty-six strains of Pasteurella anatipestifer isolated from different avian species were examined to determine their serologic types and physiologic characteristics. Serologic types were determined by a gel-diffusion precipitin test. Antigens from 39 field isolates reacted with antisera prepared from seven P. anatipestifer reference strains representing serotypes 1, 2, 4, 6, and 7. Antigens from five isolates did not react and could not be typed with available reagents. Gel precipitin reactions involving serotype 1 (43.6%) and serotype 2 (25.6%) were the most prevalent. Generally, the physiologic characteristics from 40 tests were typical for P. anatipestifer, and variations were observed among the strains in urease production, hemolysin production, litmus milk reaction, and gelatin liquefaction.

Animals↗

PubMedDate not supplied

[Pathogenesis of lung damage caused by Pasteurella haemolytica].

Pneumonic pasteurellosis is the major economic problem of the cattle industry in North America. This disease is characterized by an acute, severe, fibrinonecrotic pleuropneumonia. Pasteurella haemolytica A1 is commonly isolated from these pneumonic lesions. It has been demonstrated that stress or viral infection compromises defense mechanisms of the upper respiratory tract and lung, predisposing to an initial multiplication of bacteria in the nasopharynx and, subsequently, lungs are deluged with large numbers of bacteria. Once multiplication in the alveoli has begun, virulence factors exert their influence to induce an excessive host inflammatory response that results in severe tissue damage. Despite a large number of studies conducted to explore the complex interaction between P. haemolytica and the host response, there still remains a lack of detailed understanding. This review discusses evidence of the role of the main virulence factors of P. haemolytica on the pathogenesis of pulmonary damage.

Animals↗

PubMedDate not supplied

Capsular hyaluronic acid-mediated adhesion of Pasteurella multocida to turkey air sac macrophages.

Serogroup A strains of Pasteurella multocida, the major cause of fowl cholera, are resistant to phagocytosis in nonimmunized birds. Adherence studies with a capsulated strain of P. multocida (serotype A:3) and turkey air sac macrophages in culture showed that the bacteria were capable of adhering in large numbers to the macrophages but were not internalized. A noncapsulated variant of the bacteria (serotype -:3) showed little or no adherence and was not internalized. These data indicated that the adhesive properties were caused by the presence of a capsule on the bacteria. The role of capsular hyaluronic acid in adherence to macrophages was investigated. Depolymerization of the bacterial capsule with hyaluronidase increased phagocytosis by macrophage cultures, and addition of hyaluronic acid to the macrophages inhibited bacterial adherence. Additionally, exposure of macrophages to chondroitin sulfate B, an anionic polysaccharide similar to hyaluronic acid, did not affect the adhesive properties and resistance to phagocytosis of capsulated organisms. Treatment of macrophages with sodium metaperiodate or trypsin suppressed bacterial binding. Collectively, these data indicate that P. multocida adhesion to air sac macrophages, but not internalization, is mediated by capsular hyaluronic acid and suggest that recognition of this bacterial polysaccharide is a result of a specific glycoprotein receptor.

Animals↗

PubMedDate not supplied

Pasteurella haemolytica complicated respiratory infections in sheep and goats.

Respiratory infections which commonly occur in sheep and goats often result from adverse physical and physiological stress combined with viral and bacterial infections. Inevitably, Pasteurella haemolytica pneumonia occurs as a result of these interactions. In this review, we present recent advances in research on the complex etiology of pneumonia involving P. haemolytica. Initially stress, induced by factors such as heat, overcrowding, exposure to inclement weather, poor ventilation, handling and transport is a major predisposing factor. Respiratory viruses including parainfluenza 3 (PI-3) virus, adenovirus type 6 and respiratory syncytial virus (RSV), and to a lesser extent bovine adenovirus type 2, ovine adenovirus types 1 and 5, and reovirus type 1 cause respiratory infections and pneumonia. More importantly these viruses also dramatically increase the susceptibility of sheep and goats to secondary P. haemolytica infection. Primary infection of the lower respiratory tract, with Mycoplasma ovipneumoniae and Bordetella parapertussis can increase the susceptibility of sheep and goats to secondary P. haemolytica infection. It is possible that initial infections with viral or primary bacterial agents break down the antimicrobial barrier consisting of beta defensins and anionic peptides found in epithelial cells, resident and inflammatory cells, and serous and mucous secretions of the respiratory tract. Loss of barrier integrity may release P. haemolytica from its usual commensal status. Once in the lung, P. haemolytica becomes opportunistic. To grow and colonize, P. haemolytica uses extracellular products like O-sialoglycoprotein endopeptidase, neuraminidase and RTX leukotoxin, as well as cell-associated products such as capsular polysaccharide, lipopolysaccharide, outer membrane proteins, proteins involved in iron acquisition and a periplasmic superoxide dismutase. In lambs and kids, pneumonic pasteurellosis can be acute, characterized by fever, listlessness, poor appetite and sudden death. Sheep and goats that survive the acute stage may recover or become chronically affected showing reduced lung capacity and weight gain efficiency and sporadic deaths may occur. This infection is detrimental to sheep and goats throughout the world and flocks and herds of small ranches, dairy operations, or large feedlots are all affected.

Animals↗