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Published on: October 19, 2010
Detection of motility and putative synthesis of flagellar proteins in Salmonella pullorum cultures
1USDA/ARS Southeast Poultry Research Laboratory, Athens, Georgia 30605, USA. pholt@ix.netcom.com
Abstract:
Salmonella pullorum is a host-adapted pathogen of poultry previously thought to be nonmotile and nonflagellated. We discovered that motility can be induced in this organism under special medium conditions, and this motility was observed in 39 of 44 S. pullorum isolates tested. The migration appeared to occur only on the medium surface and not within the medium itself, indicating that swimming may not be responsible for this event. Agar concentration, carbohydrate concentration and type, and temperature of incubation all affected the motility. Flagellar stains and transmission electron micrographs of the motile S. pullorum culture showed long fibrous appendages resembling flagella extending from the cells, but these appendages were thinner and less numerous than the flagella observed on Salmonella enteritidis. Antisera to G flagellar antigens reacted strongly with the induced-motility S. pullorum culture, indicating that G epitopes were expressed on these cells. These results indicate that, contrary to the paradigm which held that S. pullorum is nonmotile and nonflagellated, motility can be induced in S. pullorum and that the organism appears to have the capacity to produce flagella.
Insights
Salmonella pullorum, a poultry pathogen, can be induced to exhibit motility and express flagella under specific laboratory conditions, challenging previous assumptions about its nonmotile nature.
Area of Science:
- Microbiology
- Bacteriology
- Poultry Science
Background:
- Salmonella pullorum is a significant poultry pathogen.
- It was historically considered nonmotile and nonflagellated.
- This study investigates the potential for motility and flagellar expression.
Purpose of the Study:
- To determine if Salmonella pullorum exhibits motility.
- To investigate the conditions that induce motility.
- To characterize the flagellar structures and antigens expressed.
Main Methods:
- Culturing Salmonella pullorum isolates on specialized media.
- Observing motility under microscopy.
- Utilizing flagellar staining and transmission electron microscopy (TEM).
- Performing serological analysis with antisera to flagellar antigens.
Main Results:
- Motility was induced in 39 of 44 Salmonella pullorum isolates under specific conditions.
- Motility occurred on the medium surface, not through swimming.
- TEM and flagellar staining revealed flagella-like appendages.
- Antisera to G flagellar antigens showed strong reactivity.
Conclusions:
- Salmonella pullorum can be induced to exhibit motility.
- The organism possesses the capacity to produce flagella.
- This finding challenges the established paradigm of S. pullorum being nonmotile.
