Pathological investigations of Vibrio vulnificus infection in Genetically Improved Farmed Tilapia (Oreochromis niloticus L.) cultured at a floating cage farm of India

Sumithra, T G and Reshma, K J and Nair, V Anusree and Sayooj, P and Sharma, S R Krupesha and Suja, G and Amala, P V and Joseph, Shoji and Sanil, N K (2019) Pathological investigations of Vibrio vulnificus infection in Genetically Improved Farmed Tilapia (Oreochromis niloticus L.) cultured at a floating cage farm of India. Aquaculture, 511. pp. 1-11.

[img] Text
Aquaculture_2019_Sumithra T G_Pathological investigations of Vibrio vulnificus infection.pdf

Download (2MB)
Official URL: https://www.sciencedirect.com/science/article/pii/...
Related URLs:

    Abstract

    An outbreak of skin ulcers with morbidity and mortality rate of 80% and 20% respectively, among Genetically Improved Farmed Tilapia (GIFT) sub-adults reared in a brackish water floating cage farm of Kochi, Kerala, India was reported. Bacterial isolation attempts from various internal organs (blood, kidney, liver, spleen and brain) of different diseased fish indicated a common bacterial etiology. Organisms were identified as Vibrio vulnificus based on conventional microbiological methods followed by molecular confirmation. Additionally, V. vulnificus marker specific for fish virulence was present in the isolates. Fish pathogenicity was confirmed by challenge tests. LD50 was calculated as 2.1 × 105.13 CFU/fish and 2.1 × 106.12 CFU/mL in injection and immersion route respectively. pilF polymorphism-based PCR and vvhA gene sequence indicated potential danger for humans. The strain was positive for siderophore, hemolysin, capsule, polar and lateral flagella. The strain could multiply rapidly in healthy fish serum. All these results indicated that the isolate could act as a primary pathogen for tilapia fish. Interestingly, serum survival ratio of the pathogen was significantly larger at higher temperatures (p ≤ .05); which may explain the increase in infective capacity of V. vulnificus at higher temperature. Multiple antibiotic resistance index of the strain was ≤0.2. In conclusion, the paper provides detailed descriptions of clinical signs, microscopic and macroscopic lesions of a natural disease outbreak among tilapia raised in brackish water cage farms of India. The concurrent attempts to identify and characterize the etiology fetches the basis for future development of effective control and preventive measures against V. vulnificus, the most infectious and lethal of all zoonotic vibrios.

    Item Type: Article
    Uncontrolled Keywords: Vibrio vulnificus; vvhA gene; pilF polymorphism; GIFT; Cage farm
    Subjects: Aquaculture > Cage culture
    Fish Biotechnology > Microbiology
    Fish Diseases
    Divisions: CMFRI-Kochi > Marine Biotechnology
    Subject Area > CMFRI > CMFRI-Kochi > Marine Biotechnology
    CMFRI-Kochi > Marine Biotechnology
    Subject Area > CMFRI-Kochi > Marine Biotechnology
    Depositing User: Arun Surendran
    Date Deposited: 18 Jun 2019 10:32
    Last Modified: 18 Jun 2019 10:32
    URI: http://eprints.cmfri.org.in/id/eprint/13679

    Actions (login required)

    View Item View Item