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.

An epornitic of avian cholera in waterfowl and common crows in Phelps County, Nebraska, in the spring, 1975.

In the spring of 1975, many species of waterfowl and common crows (Corvus brachyrhynchos) were found dead in Phelps County, Nebraska. About 25,000 water fowl and at least 3,000 crows died in the epornitic. Few waterfowl were seen dying, but the crows experienced a chronic illness during which they became debilitated and were lethargic and dyspneic. Gross and microscopic lesions in the waterfowl were typical for acute avian cholera. The crows had dark, firm areas within the lungs, loosely adhered yellow fibrous material in the pericardial sac and air sacs and, occasionally, liver abscesses. Microscopically, focal purulent pneumonia was present and a fibrinopurulent exudate overlaid a granulomatous reaction on the heart and lung surfaces. Isolation of Pasteurella multocida serotype 1 confirmed the diagnosis of acute and chronic avian cholera in the waterfowl and crows, respectively.

Fowl cholera: induction of cross-protection in turkeys with bacterins prepared from host-passaged Pasteurella multocida.

Modified fowl cholera bacterins prepared by inoculating agar medium with infected liver tissue from birds which died of acute fowl cholera induced 70% cross-protection in turkeys, i.e., protection against a different immunologic type of Pasteurella multocida. Standard bacterins prepared from cultures which had been lyophilized and stored showed variable cross-protection (0--40%). Repeated subculturing of the standard inoculum on agar reduced cross-protection. The protection with either the modified or standard bacterins was comparable (80--100%) when immunity was challenged with the homologous strain. With lyophilization of P. multocida and subculturing on agar, it appears that antigens capable of inducing cross-immunity may be lost more readily than antigens capable of inducing homologous immunity.

Immunogenic and toxic properties of a purified lipopolysaccharide-protein complex from Pasteurella multocida.

An immunogenic fraction from Pasteurella multocida was found to consist chiefly of a high-molecular-weight protein-polysaccharide complex containing 25 to 27% protein and 10.7% carbohydrate. The starting material was obtained by differential centrifugation at 105,000 X g of saline extract of P. multocida cells and further purified by gel filtration on Sepharose 2B. Three peaks were usually obtained after gel filtraion.pharose 2B. Three peaks were usually obtained after gel filtration. The component in the first peak amounted to about 10% of the starting material and eluted in the void volume. It was predominately carbohydrate, although some protein was present. Two inoculations of 10 to 20 mug of the first component induced up to 80% protection in mice against a challenge inoculation with P. multocida that killed 100% of the controls. The second, or major, component amounted to about 75 to 95% of the starting material. This fraction contained 25 to 27% protein and 10.7% carbohydrate. Small amounts, 10 to 20 mug, induced active immunity in mice and turkeys, but large amounts could be lethal; the mean lethal dose was 195 mug for mice and 5.7 mug for 10-day-old chicken embryos. The components in the third peak were primarily proteins that gave reactions of nonidentity with the antigens of peak II in gel diffusion. The components present in the third fraction were definitely less effective in the induction of protective immunity than those present in the first or second. Analyses of the protective antigen(s) by the isoelectric focusing procedure in a pH 3 to 10 gradient showed that all of the precipitinogenic activity was found in the range of pH 3 to 4, with a peak at pH 3.7.

Physiologic characteristics of 1,268 cultures of Pasteurella multocida.

Results of 29 physiologic tests are reported for 1,268 cultures of Pasteurella multocida from various hosts over a 10-year period. Of the cultures, 97 to 100% fermented galactose, glucose, mannitol, mannose, fructose, and sucrose, produced hydrogen sulfide and indole, and reduced nitrate; 6 to 91% fermented arabinose, glycerol, sorbitol, trehalose and xylose. Fermentation of dextrin, dulcitol, inositol, inulin, lactose, maltose, raffinose, rhamnose, and salicin, growth on MacConkey agar, change of litmus milk, production of urease and hemolysin, liquefaction of gelatin and motility were negative with 97 to 100% of the cultures. Of 200 cultures tested for catalase and oxidase, all were positive. Results of this study indicate that none of these tests will determine the host from which the culture was isolated.

Characteristics of Pasteurella multocida of human origin.

Physiological, serological, morphological, and cultural differences were observed among 30 Pasteurella multocida cultures of human origin. The usual variations in the fermentation of glycerol, lactose, sorbitol, trehalose, and xylose were observed. Unlike most P. multocida, two cultures did not produce indol. Six serotypes were found. In addition to the widely recognized iridescent, blue, and watery mucoid (circular) colonies, punctiform colonies were observed. None of the cultures were pathogenic for turkeys. Results of the study indicate that one should be aware of the many variable characteristicx of P. multocida of human origin to facilitate indentification.

Pasteurella multocida serotyping results (1971-1973).

Pasteurella multocida serotyping results were compiled and reported for 1971-1973. A total of 762 isolations from 20 different animal species from 23 states were serotyped. Serotype 3 was most common, accounting for 53% of the isolations.

Properties of free endotoxin from Pasteurella multocida.

Free endotoxin (FET) from virulent encapsulated Pasteurella multocida or from an avirulent nonencapsulated mutant is capable of inducing active immunity, but the lipopolysaccharide (LPS) moiety of the endotoxin is not. These results suggest that a protein of P multocida is involved in the stimulation of active immunity. The serologic specificity of the FET is associated with the LPS moiety, which is related to a heat extracted antigen that is used for serotyping P multocida. The FET is capable of producing widespread vascular alteration and death. It is present in the vascular system of turkeys with acute fowl cholera, and it can be detected with the "Limulus" test for endotoxins and with the gel diffusion precipitin test.

Fowl cholera; cross-protective turkey antisera and IgG antibodies induced with Pasteurella multocida-infected tissue bacterins.

Turkey antisera induced with formolized Pasteurella multocida-infected tissues (T antisera) passively cross-immunized 48 of 55 chickens against a challenge dose of P. multocida organisms, from which 0 of 15 controls survived. However, turkey antisera induced with formalin-killed, agar-cultured P. multocida cells (A antisera) passively cross-immunized only 4 of 30 chickens. Cross-immunity refers to protection against a different immunologic type of P. multocida. Quantitative precipitin reactions of the A and T antisera with antigens from agar-cultured cells showed that more antibody was present in the A than in the T antisera. However, antigens extracted from the infected tissues reacted with the T and not with the A antisera in the Ouchterlony procedure, demonstrating qualitative differences between the agar-cultured antigens and those extracted from the infected tissue. The gel precipitins isolated from the A and T antisera were characterized as 7S immunoglobulins, which behaved in immunoelectrophoresis as would be expected for a IgG immunoglobulin. The IgG fraction from the T antiserum passively cross-immunized chickens almost as well as the whole antiserum; hence, the IgG antibody is a major factor in cross-immunity.

Fowl cholera: immunologic and werologic response in turdeys to live Pasteruella multocida vaccine administered in the drinking water.

Live fowl cholera vaccine administered in drinking water induced immunity in young turkeys against a challenge of a different immunogenic type of Pasteurella multocida; this is referred to as cross-immunity. Serum from the vaccinated birds induced passive cross-immunity in chicks and turkeys; this demonstrated that the cross-immunity induced with the drinking water vaccine was associated with the humoral system. Results of serologic tests with agar grown P. multocida indicate that agglutinins and precipitins are not associated with the induced cross-immunity. A live culture of P. multodica previously reported to induce cross-immunity in mature turkeys without causing adverse effects when administered in the drinking water, killed 6 of 45 (13 per cent) poults in the present study; this demonstrated that young turkeys are more susceptible to fowl cholera than mature turkeys.