tailieunhanh - Streptococcus in Tilapia

Streptococcosis has become a major problem for tilapia farmers and there is still no effective commercial vaccine available that can be used to prevent streptococcosis in tilapia. Tilapia growers must therefore focus on prevention and treatment of the disease. Streptococcosis can cause mass death in tilapia farms, and unlike many other tilapia diseases it will affect even large and otherwise healthy fish. | Streptococcus in Tilapia Streptococcosis has become a major problem for tilapia farmers and there is still no effective commercial vaccine available that can be used to prevent streptococcosis in tilapia. Tilapia growers must therefore focus on prevention and treatment of the disease. Streptococcosis can cause mass death in tilapia farms and unlike many other tilapia diseases it will affect even large and otherwise healthy fish. Fish weighing at least 100 grams are actually more susceptible to streptococcosis than small fish. Streptococcosis outbreaks are known to take place primarily when the fish has been subjected to some form a stress . due to overcrowding improper water chemistry or changing water temperatures. If you want to decrease the risk of streptococcosis in your tilapia the best course of action is therefore to minimize the amount of stress that your fish is forced to deal with. Keep your tilapia in a suitable stable environment and feed them nutritious food. A tilapia can catch streptococcosis from the environment as well as from an infected fish. Streptococcosis can be acute or chronic. Acute streptococcosis normally occurs during the warm season when the water temperature is high and will typically result in peaks of mortality that goes on for 2-3 weeks. Chronic streptococcosis occurs when the water temperature is lower and does not cause any peaks of mortality. The mortality rate will be low but the amount of dead fish will become high in the long run since the mortality level tends to be really persistent. What causes streptococcosis in tilapia In farmed tilapia the major cause of streptococcosis is Streptococcus agalactiae including the previously described Streptococcus difficilis difficile now reclassified as Streptococcus agalactiae . The closely related bacterium Streptococcus iniae can also cause streptococcosis in tilapia but is normally not as lethal as Streptococcus agalactiae. All species of Streptococcus are gram-positive non-acid .