الفهرس 
Cover Page Title in EnglishOnly 14 pages are availabe for public view
 |  | from | 187 |  |  |
| | | from | 187 | | |
Abstract
A total number of 100 fish samples of different Spp. were collected from different areas in both Behera and Kafr El-Sheikh Governorates, for study of:
Incidence of Yersinia ruckeri among Oreochromis niloticus , Common carp and Monosex fish and losses resulted from infection of the fish by Y. ruckeri. The bacteriological characters of isolated .I: ruckeri, in vitro, sensitivity test of the isolated .I: rucked against the cornmon used antibiotics, the pathogenicity of Y. rucked in Oreochromis niloticus , Common carp and Monosex fish via its effect on blood cell constituents (RBCs, WBCs and differential leucocytic counts) and blood serum protein constituents (albumin, globulin and total proteins), and serum enzymes. The histopathological alterations in different organs of fish experimentally infected with .I: ruckeri.
This study indicated that:
The Monosex tilapia is of high resistance to Yersinia infection than Oreochromis niloticus and the least resistance in Common carp fish. As the mortality percentage in Monosex tilapia was lower than Common carp fish.
The antibody titer for Monosex tilapia were higher than the C.
carp.
The lymphocyte count increased steadily from the 1 st week to the 4th week and the level of lymphocyte count was higher in Monosex tilapia than Common carp and with the fish infected with Yersinia than the fish without infection or control fish, while the monocyte count increased also, from the 1 st week to the 4th week. Moreover, level of monocyte in control fish was higher in control than infected fish and in the Monosex was higher than Common carp.
The neutrophils count decreased steadily from the 1 st week to the 4th week and the infected fish is of higher count than the non infected fish. And the Monosex fish is of higher count than the Common carp fish.
The Phagocytic activity values increased steadily from the 1 st week to 4th week.
The phagocytic activity increased in the control group without Yersinia in either monosex or Common carp and the phagocytic activity increased in Monosex than Common carp in infection cases.
The monosex tilapia of high WBCs values than Common carp and the infected fish of lower values than control fishes. The values increased from the first week to the 4th week steadily.
While, The RBCs count, Hb decreased from the 1 st week to the 4th week steadily, but the Monosex tilapia and control fish of higher RBCs values than the Common carp and infected fish with Yersinia.
The GPT & GOT values increased steadily from the 1 st week to the 4th week and increased in the infected fish than control fish especially in the last weeks and in Common carp fish than Monosex tilapia.
Generally, the alkaline phosphatase level increased steadily from the 1 st week to the 4th week. and it increased in the Monosex tilapia than the Common carp and in infected fish than the control fish especially at the last week from the experiment.
The Glucose level decreased, also steadily from the 1 st week to the 4th week, and the glucose level in the Monosex tilapia fish of higher concentration than the Common carp and it decreased in the infected fish with Yersinia than the control fish.
The Cholesterol level increased steadily from the 1 st week to the 4th week. Its level in the infected fish was higher than control fish, while its level in the Monosex tilapia was higher than the Common carp.
The protein level differs from species to another and from one period to another after injections
There was a decrease in the total protein, albumin and globulin levels along the experimental period but its level was higher in Monosex fish than Common carp.
The LD50 of isolated ~ ruckeri in O. niloticus, C. carp and M. tilapia were 104.5, 103.75 and 103.5, respectively.
The relative level of protection was higher in Monosex tilapia (0.33) than the Common carp (0.20) that indicated that the M. tilapia was higher than that of C. Carp due to the M. tilapia of high immunity and resitant to diseases than C. carp fish.
The A/G ratio increased in healthy control fish than in the infected fish and in Monosex tilapia than the Common carp.
Histopathological alterations III different organs of fish experimentally infected with ~ ruckeri were discussed.
The Yersinia ruckeri of high susceptibility to the antibiotics of Erythromycin, Neomycin, Penicillin and Streptomycin.