Shrimp aquaculture is a booming industry, but keeping shrimp healthy can be a challenge. Two major threats come from bacterial strains of Vibrio parahaemolyticus, responsible for acute hepatopancreatic necrosis disease (AHPND), and Vibrio harveyi, which causes luminous vibriosis. These bacteria can cause serious diseases and death in shrimp.
A team of researchers from the Southeast Asian Fisheries Development Center, Aquaculture Department (SEAFDEC/AQD), The Hebrew University of Jerusalem, Biosolutions International Corporation, INVE Technologies, and the University of Crete Heraklion tested the bioactivities of two commercially available probiotics and a chemical disinfectant against strains of Vibrio parahaemolyticus (VPAHPND) and V. harveyi. This study aimed to determine the in vitro and in vivo sensitivity of shrimp pathogenic Vibrios to commercial probiotics and a chemical disinfectant.
The researchers were interested in understanding how effective these treatments were against harmful Vibrio strains, both in the lab and in the real world.
Scientifically backed solutions
Traditionally, antibiotics were used to combat bacterial infections. However, the overuse of antibiotics has led to the emergence of antibiotic-resistant bacteria, posing a serious threat to human and animal health.
This study investigated the efficacy of two commercially available probiotics and a disinfectant against these harmful Vibrio strains. In the laboratory (in vitro), researchers tested how well these treatments inhibited bacterial growth. They then moved on to real-world experiments (in vivo) with live shrimp.
Probiotics to the rescue
The study looked into the power of probiotics, which are live microorganisms that offer health benefits. Researchers tested two types of probiotics: those directly added to shrimp feed and those introduced into water tanks. The results were promising.
When exposed to Vibrio strains, shrimp that received probiotics (either in food or water) had significantly higher survival rates.
However, not all probiotics are equal. For a probiotic to be effective, it’s crucial to choose a product with the right bacterial strains, administered in the correct manner and at the appropriate dosage. Thus, further rigorous studies are needed to validate the effectiveness of various probiotic products.
Chemical disinfectants: a double-edged sword
Chemical disinfectants are another tool used to control bacterial pathogens like Vibrio. While they can be effective in eliminating bacteria present in water, their success largely depends on factors such as the amount of organic matter in the water. Additionally, some disinfectants may have negative impacts on the health of cultured shrimp and overall water quality.
For example, formalin, a common disinfectant, can damage shrimp gills and disrupt biological filters. Similarly, some disinfectants are highly toxic to aquatic organisms and can harm the environment. Therefore, the use of disinfectants requires careful consideration of the specific species being cultured, the target disease, and the impact on the surrounding ecosystem.
The study also evaluated a chemical disinfectant, focusing on its ability to kill harmful bacteria. The disinfectant proved effective at concentrations of 2500 ppm and 5000 ppm. However, unlike probiotics, the effectiveness of the disinfectant depends on various factors, including the exact concentration used and the timing of application.
Conclusion: a multifaceted approach
This study suggests that incorporating probiotics into shrimp diets or rearing water can be a valuable preventive measure. Probiotics help reduce overall levels of harmful bacteria in the environment, making disease emergence more difficult.
While disinfectants offer a powerful tool for eliminating existing bacteria, their use requires careful planning and application. Disinfectants are not only useful for treating tank water but can also be used to decontaminate pond linings, tanks, and other equipment, preventing future outbreaks.
By combining proactive measures such as probiotics with the specific use of disinfectants, shrimp growers can create a healthier environment for their valuable crop.
The study was funded by the Southeast Asian Fisheries Development Center/Aquaculture Department.
Contact
Leobert D. de la Peña
Southeast Asian Fisheries Development Center, Aquaculture Department (SEAFDEC/AQD), Tigbauan, Iloilo 5021, Philippines
Email: leobertd@seafdec.org.ph
Reference
De la Peña, L. D., Moquera, G. L., Amar, E. C., Castellano, J. L. A., Cabillon, N. A. R., Arboleda, J. I., Nava, J. K. P. T., Zamora, R. V., & De Schryver, P. (2024). In vitro and in vivo evaluation of the efficacies of commercial probiotics and disinfectant against acute hepatopancreatic necrosis disease and luminescent vibriosis in Litopenaeus vannamei. Research in Veterinary Science, 105204. https://doi.org/10.1016/j.rvsc.2024.105204
