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Electronmicroscopy of the surface of Pasteurella haemolytica
Abstract:
The surfaces of Pasteurella haemolytica, biotype A, serotypes 1, 2, 6, 7 and 9 and of P. haemolytica, biotype T serotypes 3, 4, 10 and 15 were examined by transmission electronmicroscopy with ruthenium red staining and polycationic ferritin labelling, by scanning electronmicroscopy, and by light microscopy. Electronmicroscopy showed that the surface of strains of P. haemolytica biotype A was covered by irregular protrusions which were probably capsular material. The surface and general morphology of P. haemolytica biotype T were distinct from those of biotype A.
Insights
The surfaces of Pasteurella haemolytica biotype A strains feature irregular protrusions, likely capsular material. Pasteurella haemolytica biotype T strains exhibit distinct surface morphology compared to biotype A.
Area of Science:
- Veterinary Microbiology
- Bacteriology
- Microbial Ultrastructure
Background:
- Pasteurella haemolytica is a significant bacterial pathogen in ruminants.
- Distinct biotypes (A and T) of Pasteurella haemolytica exist, with potential differences in virulence factors.
- Understanding surface structures is crucial for pathogen identification and control.
Purpose of the Study:
- To characterize and compare the surface ultrastructure of Pasteurella haemolytica biotype A and biotype T strains.
- To investigate the presence and nature of capsular material on biotype A strains.
- To identify distinct morphological features between the two biotypes.
Main Methods:
- Transmission electron microscopy (TEM) with ruthenium red staining.
- Polycationic ferritin (PF) labelling for surface charge analysis.
- Scanning electron microscopy (SEM) for surface topography.
- Light microscopy (LM) for general morphology.
Main Results:
- TEM revealed irregular protrusions on the surface of Pasteurella haemolytica biotype A strains, indicative of capsular material.
- Distinct differences in surface morphology and general ultrastructure were observed between biotype A and biotype T strains.
- Ruthenium red staining and PF labelling provided insights into the composition and charge of the surface structures.
Conclusions:
- Pasteurella haemolytica biotype A possesses a distinct surface characterized by probable capsular material.
- Significant ultrastructural differences exist between Pasteurella haemolytica biotype A and biotype T.
- These morphological distinctions may correlate with differences in pathogenicity or host interaction.