The pathogenesis of Pasteurella multocida serotype A:3,4 infection in turkeys: a comparison of two vaccine strains and a field isolate |
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| Authors: | M M Prantner B G Harmon J R Glisson E A Mahaffey |
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| Institution: | Department of Veterinary Pathology, College of Veterinary Medicine, University of Georgia, Athens 30602. |
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| Abstract: | The pathogenesis of avian pasteurellosis caused by two vaccine strains, M-9 and Clemson University (CU), and a highly virulent field isolate, 86-1913, of Pasteurella multocida (serotype A:3,4) was studied in 7-week-old turkeys inoculated by an oculo-nasal-oral technique. Turkeys inoculated with strain CU and isolate 86-1913 developed severe progressive bacteremia that began at 4 hours postinoculation (PI) and peaked at 16-20 hours PI. Turkeys inoculated with strain CU and isolate 86-1913 had significantly higher concentrations of bacteria in blood and tissues, and greater histologic lesion scores for necrosis, heterophil infiltrates, and intralesional bacteria than turkeys inoculated with strain M-9. Immunohistochemical staining specific for P. multocida demonstrated numerous extracellular bacteria in tissues from turkeys inoculated with strain CU and isolate 86-1913. The mortality for turkeys inoculated with isolate 86-1913 was significantly higher than for turkeys receiving the two vaccine strains. |
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