Complete details about vibrio in shrimp pond.

Hello everyone:

         Nowadays, vibrio is a major threat to the shrimp farms mainly due to improper management of pond quality. It will leads to sudden mortality of all shrimps and huge economic loss occurs. If you are know about shrimp farming, definitely you often heard the word about vibrio.vibrio..vibrio..

          We have all the things for shrimp farming, we must ensure to have sufficient knowledge and proper maintenance of shrimp culture..

Vibriosis:

          It is a disease causes by the vibrio species. It is aquatic microorganism. We can't completely remove or eradicate the vibrio from pond. We have to do maintenance and controlling the proliferation of the bacteria.

         Vibrio is a gram negative and rod shaped bacteria. It is a facultative anaerobes (live with or without oxygen),but in high oxygenated condition it can produce high ATP for their survival.

           We often heard that, vibrio is majorly found in the shellfishes and cause poisoning. Yes, it is mostly present in the Crustacean shells. It is well proliferate in high saline condition. In pond preparation we very well aware about the presence of any shells or parasites.

            In high saline,cone shells also found and reproduce vigorously. We have to maintain good pond condition.

           Vibrio is opportunistic pathogen.

What is opportunistic pathogen?

           Opportunistic pathogen are not cause disease to the animal in normal condition, but if the animal is wounded or infected with other disease or reduced immune response occurs,, at that time vibrio cause disease to the animals. However various types of vibrio species found. Among them certain species such as Vibrio harveyi, V.parahaemolyticus,           V.alginolyticus are the majorly cause disease in shrimp farming. But one species Vibrio campbellii is related with wssv.

     Vibriosis causes tail necrosis, black shell disease, red disease and leads to loose shell syndrome, white gut disease, causes red colouration in pleopods and sides of the body. By this red colour appearance on the pleopods and sides of the body, we can conclude and immediately check vibrio count in lab. It causes yellowing of gill tissues. If the shrimp is infected with Vibrio harveyi means, we can detect by appearance of greenish lumniscence in the tail of the shrimp.

        Vibrio proliferate well at high salinity and high temperature conditions. It produce some quorum sensing and produces toxins. Some research told Vibrio alginolyticus can share and exchange the toxins to the other bacteria (under certain extreme conditions). Some species has the ability to alter the genome and produce variants and strains at certain conditions( like Corona virus ). At that time it is difficult to control.

 

       In lab we detect vibrio colonies using TCBS agar. This agar prevents the growth of other enterobacteriace such as E.coli, salmonella. Oxygall present in the medium prevents the growth of gram positive bacteria. Vibrio requires high alkaline Condition for the growth.

Sucrose - for metabolism.

Thymol blue and bromo thymol blue - indicates the pH changes. These are the important things present in the plating medium.

Some vibrio produces yellow colonies and some produce green colonies.

V.harveyi, V.parahaemolyticus - green colonies( not ferment the sucrose )

V.alginolyticus - yellow colonies ( fermented the sucrose in the medium and produce acids, it reduces the pH and yellow colour appears).

 

There is certain limit for the occurance of the vibrio. Yellow - less than 500 cfu/ml. Green - less than 50 cfu/ml in water.

In animal - yellow - less than 100 cfu/gm, Green - less than 50 cfu/ gm.

If the shrimp in stress condition, it leads to affect immune response and leads to increase in Vibrio.

Prevention:

            Source of water for the culture. The source of water is sea or Creek or river , it must be disinfect with chlorine. Because chlorine invades the vibrio in few minutes. If it is borewater ,we don't need to disinfect but we have to detect the presence of other toxic metals in the water. Proper preparation of the pond. Proper biosecurity measures. Use the gut probiotics to shrimp at the proper time reduce harmful bacteria in the animal.

             Prevents the accumulation of sludge in the pond. Properly maintains and give soil Probiotics to the pond. The beneficial bacteria numbers increases it prevents the other bacterial growth. It grows by the competition. Beneficial bacteria utilize the all nutrients and makes nutrient not available for harmful bacteria. So probiotics is very very important. Maintain proper biosecurity measures in pond and prevent disease and get profit... Vibrio present in all the times, but way of pond management leads to prevent the proliferation.

                               Thank you 😊.