الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 163 |  |  |
| | | from | 163 | | |
Abstract
Vibriosis is considered the most important threatening disease problem facing mariculture specially Seabass Dicentrarchus labrax. Therefore this study contributes to current knowledge for investigating the occurrence, ecology of Vibriosis and providing treatment and control measures for Vibriosis.
A total of 946 D. labrax were obtained from marine fish farms in Alexandria governorate, throughout the period from (January 2013 to January 2014) and exposed to clinical and bacteriological examinations for isolation and identification of Vibrio spp.
1) Clinically, Vibriosis in fries characterized by high mortalities, ulcers in skin and skeletal deformities. Also, infected fingerlings exhibited ulcers and hemorrhage all over the body and fin erosions. In addition, diseased breeder appeared weakened, anorexic, lethargy and highly exposed to cannibalization by healthy larger fish. The post mortem examination revealed that, liver appeared enlarged, congested or pale with engorged gall bladder. Also, spleen and kidney appeared dark and enlarged with white necrotic nodules. The intestine contained yellowish fluid and white necrotic nodules.
2) The conventional traditional diagnostic methods showed that, isolated bacteria recorded oxidase and catalase positive, sensitive to Vibriostatic agent pteridine (O/129, 150 μg) and growth at wide range of temperature (20-35OC). Both bacterial strains showed variable reactions confirmed by analysis API-20NE and API-20E systems.
PCR yielded a single amplification patterns consisting of expected size 737-bp and 267 bp for V. alginolyticus and V. damsela respectively. All isolates Vibrio alginolyticus and