Naturally occurring pasteurellosis in laboratory rabbits: chemical and serological studies of whole cells and lipopolysaccharides of Pasteurella multocida

Abstract

Whole cells and lipopolysaccharides (LPS) of 10 isolates of Pasteurella multocida from laboratory rabbits were subjected to chemical and serological analysis. LPS of most of these isolates possessed pyrogenic potency comparable to LPS from Salmonella minnesota 9700, although their average ketodeoxyoctonate content was only 18% of that of salmonella. A gel diffusion precipitin test for somatic antigens extracted in a formal-saline solution demonstrated several isolates with three to four somatic antigens, with some variation in the major somatic type from one test to another. Conversely, the use of LPS as antigen in the gel diffusion precipitin test (i) eliminated cross-reactivity with reference antisera and (ii) often resulted in the organism being typed as serotype 12 even when the type 12 antigen was a minor antigen in the formal-saline extracts. Antisera from specific pathogen-free rabbits immunized with either whole cells or LPS of two isolates were tested against whole cells or LPS of the 10 isolates by enzyme immunoassay and indirect hemagglutination. Both whole cells and LPS of one of the isolates (isolate 2) were serologically specific, whereas those of the other isolate (isolate 1) were moderately to strongly cross-reactive with other isolates. The data indicate that although LPS is the major antigen responsible for typing based on the gel diffusion precipitin test, substances other than LPS (probably capsular polysaccharide) are responsible for the type specificity that forms the basis for the A, B, D, or E classification of this organism.

Variability of cell surface hydrophobicity among Pasteurella multocida somatic serotype and Actinobacillus lignieresii strains

“…Although P. multocida LPS resembles that of smooth enteric bacteria in that they have major chemical components in common (24,31), it is also similar to rough enteric LPS with regard to having lower molecular weight (20) and, in most cases, greater hydrophobicity (31). Increased outer membrane permeability in P. multocida may be due to the LPS being structurally similar to that of rough enteric mutants (31).…”

“…That the atypical permeability properties are due to chemical composition rather than structural anomolies is implicit. The gel diffusion precipitin test developed by Heddleston et al (14) has been used to demonstrate 16 distinguishable serotypes (2, 5) on the basis of the heatstable somatic antigenicity of lipopolysaccharide (LPS) (24,31). Lugtenberg et al (20) have reported the LPS of P. multocida to be of lower molecular weight than that found in certain smooth members of the family Enterobacteriaceae, suggesting fewer repeating sugars and subsequently shorter 0-side-chain length.…”

Enzyme-linked immunosorbent assay for immunoglobulin G antibody to Pasteurella multocida in rabbits

“…been widely used for a variety of reasons (3). The indirect hemagglutination assay, one of the more frequently used tests, lacks sensitivity (14). Comparison of the agglutination test and the ELISA for measuring antibody responses in turkeys receiving oral vaccination against P. multocida revealed that the ELISA was more sensitive and correlated with protection against oral challenge with virulent P. multocida (15).…”

“…Culture techniques to detect infection are time consuming, and failure to isolate the organisms may be due to their low numbers or inaccessible location rather than to their absence. Although a number of procedures have been developed for the measurement of humoral immunity, recent reports (6,14,15) indicate that antibody detection by the enzyme-linked immunosorbent assay (ELISA) may be more suitable for assessment of pasteurella infection. We therefore explored the use of ELISA for detecting antibodies to P. multocida in naturally infected rabbits.…”

Bacteriological and Serological Studies on <I>Pasteurella multocida</I> Infection in Rabbits

“…Recently, a few reports concerning antibody production in rabbit pasteurellosis [6,17,19,21,35] have been published. These investigators employed the tube agglutination test using formalinized whole cell antigen [35], the agar gel precipitation test using somatic antigen [19] and the enzyme-linked immunosorbent assay (ELISA) using boiled-cell extract, and appraisable results were obtained by the latter two methods.…”