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Serological response to Pasteurella multocida NanH sialidase in persistently colonized rabbits
Susan Sanchez1, Shaikh Mizan, Charlotte Quist
1Athens Diagnostic Laboratory, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
Abstract:
Pasteurella multocida is a mucosal pathogen that colonizes the upper respiratory system of rabbits. Respiratory infections can result, but the bacteria can also invade the circulatory system, producing abscesses or septicemia. P. multocida produces extracellular sialidase activity, which is believed to augment colonization of the respiratory tract and the production of lesions in an active infection. Previously, it was demonstrated that some isolates of P. multocida contain two unique sialidase genes, nanH and nanB, that encode enzymes with different substrate specificities (S. Mizan, A. D. Henk, A. Stallings, M. Meier, J. J. Maurer, and M. D. Lee, J. Bacteriol. 182:6874-6883, 2000). We developed a recombinant antigen enzyme-linked immunosorbent assay (ELISA) based on the NanH sialidase of P. multocida and demonstrated that rabbits that were experimentally colonized with P. multocida produce detectable anti-NanH immunoglobulin M (IgM) and IgG in serum, although they demonstrated no clinical signs of pasteurellosis. In addition, clinically ill pet rabbits infected with P. multocida possessed IgM and/or IgG antibody against NanH. The NanH ELISA may be useful for the diagnosis of P. multocida infections in sick rabbits as well as for screening for carriers in research rabbit colonies.
Insights
A new enzyme-linked immunosorbent assay (ELISA) detects antibodies against Pasteurella multocida NanH sialidase in rabbits. This diagnostic tool can identify infections in both sick and carrier rabbits, aiding disease control.
Area of Science:
- Veterinary Microbiology
- Immunodiagnostics
Background:
- Pasteurella multocida is a significant rabbit pathogen causing respiratory disease and systemic infections.
- The bacteria's extracellular sialidase activity, particularly NanH, is implicated in colonization and lesion development.
- Existing diagnostic methods may not effectively identify all infected or carrier rabbits.
Purpose of the Study:
- To develop and validate a recombinant antigen enzyme-linked immunosorbent assay (ELISA) for detecting antibodies against P. multocida NanH sialidase.
- To assess the utility of the NanH ELISA for diagnosing P. multocida infections in rabbits, including asymptomatic carriers.
Main Methods:
- Development of a recombinant antigen ELISA utilizing the NanH sialidase of P. multocida.
- Testing serum samples from experimentally infected rabbits (with and without clinical signs) and naturally infected pet rabbits.
- Detection of anti-NanH immunoglobulin M (IgM) and IgG antibodies using the developed ELISA.
Main Results:
- Rabbits experimentally colonized with P. multocida produced detectable anti-NanH IgM and IgG, even without clinical signs.
- Clinically ill pet rabbits infected with P. multocida also showed positive results for anti-NanH antibodies.
- The NanH ELISA demonstrated sensitivity in detecting P. multocida infection in both symptomatic and asymptomatic rabbits.
Conclusions:
- The developed NanH ELISA is a promising tool for diagnosing P. multocida infections in rabbits.
- This assay can aid in identifying infected rabbits, including subclinical carriers, which is crucial for disease management.
- The NanH ELISA offers a valuable method for screening rabbit populations, particularly in research settings and pet populations.
