Pasteurella multocida causes diseases in many animal
species including fowl cholera, a septicemic disease of
poultry and other birds. Pathogenesis of the disease has
been studied by many investigators by the systemic
administration of the organism in poultry. However, only a
few studies have been done as to the respiratory
pathogenesis of the organism. The objective of the study
was to investigate the fate of P. multocida after the
intratracheal administration in turkeys
The fate of four strains of Pasteurella multocida was
studied after their intratracheal inoculation in young adult
turkeys. Viable bacterial counts were made in respiratory
tissues as well as in the liver, spleen and blood at 6 and 9
hrs after the inoculation of approximately 10⁹ viable
organisms of each strain. A virulent, encapsulated strain,
P-1059, invaded systemically by 6 hrs postinoculation (PI)
and multiplied vigorously in all tissues and organs
examined. A blue colony mutant of P-1059, T-325, which does
not possess a thick layer of capsule, as well as CU vaccine
strain, invaded the parenchymal organs, but did not show
significant increase in viable counts at 9 hrs PI compared
with at 6 hrs PI. Another vaccine strain, M-9, also invaded
blood and internal organs by 6 hrs PI, however, its viable
counts showed no significant change between 6 and 9 hrs PI,
or in some tissues significant decrease at 9 hrs PI. The
results indicate that all the four strains possess high
capacity to invade respiratory tissues with varying capacity
to persist in host tissues.
The lesions caused by two strains of Pasteurella
multocida (P-1059 and M-9) were observed after their
intratracheal inoculation in young adult turkeys. The
lesions were observed in the respiratory organs at 0, 0.25,
0.5, 1, 2, 3, and 6 hrs after inoculation of approximately
10⁹ viable organisms of each strain. Both virulent strain,
P-1059 and non-virulent vaccine strain, M-9, have capacity
to invade and multiply in the tissues examined.
Macroscopicly, the lesions in the lung and in the airsac
were found as early as 1 hr PI, including the infected lung
was foamy and the airsac became cloudy. They became more
severe by 2 to 6 hrs PI. Microscopicly, hecerophiles were
present, occasionally, in the lung, trachea and airsac by 0
to 1 hr after inoculation. Then they became more severe by
2 to 6 hrs PI. By 6 hrs PI, there were diffuse
heterophiles infiltration in the trachea, lung, anc airsac.
The lung vascular was edema. The trachea ciliate and mucous
gland was cystic or hyperplasia, and the airsac shewed
increased in thickness and cloudiness. These results of
study indicate that the lesion caused by P-1059 and vaccine
strain, M-9, were not significantly different. / Graduation date: 1992
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/37228 |
| Date | 18 November 1991 |
| Creators | Abrar, Mahdi |
| Contributors | Matsumoto, Masakazu |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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