A. Cause: Edwarsiella tarda



B. Characteristics of pathogens:

- Edwardsiella tarda is a bent rod shaped, is a gram-negative bacteria, this bacteria moves with the help of flagella, does not form spores or capsules, is facultative anaerobic, and is capable of producing H2S;

- These bacteria can be found in freshwater and seawater environments, these bacteria infect several types of fish, including: salmon, catfish, mas, tilapia. Some natural hosts can survive as carriers;

- Transmission of the disease can occur horizontally, ie spread through contact between one host and another or through water;

- Edwardsiellosis cases generally occur at relatively high pond water temperatures (± 30 oC) with high content of organic matter dissolved in water;

- The mortality rate of fish depends on environmental conditions, in very bad conditions can lead to death up to 50%.



C. Clinical Symptoms:

- External symptoms of fish attacked by edwardsiellosis in mild infections, only showing minor injuries;

- As further disease progresses, festering wounds develop in the rib muscles and stomach;

- In acute cases there will be a rapidly increasing festering wound of various sizes;

- Pale body color, bloated stomach filled with yellowish or reddish fluid, bleeding in the anus and / or anus is pressed into, and the eyes of the fish fade;



D. Diagnosis:

- Isolation and identification of bacteria through bio-chemical tests;

Detection of bacterial genes through polymerase chain reaction (PCR) technique.



E. Control:

- Cultivation facilities need to be disinfected before and during the fish rearing process;

- Immunostimulant elements need to be given (for example adding vitamin C to feed) regularly during maintenance;

- Avoiding stress on fish (physical, chemical, biological);

- Water quality needs to be improved as a whole, especially reducing dissolved organic matter levels and / or increasing the frequency of new water replacements;

- Manage integrated fish health (fish, environment and pathogens);

- Treatment with herbs using meniran leaves (Phyllanthus niruri L., P urinaria L.) in ways such as treatment of diseases caused by Aeromonas hydrophilla.