The Extract of Larrea tridentata Promotes the Synthesis of Silver Nanoparticles and Stimulates Immune Responses in Penaeus vannamei Against Vibrio spp., Causing Acute Hepatopancreatic Necrosis Disease

Specific strains of Vibrio parahaemolyticus can cause Acute Hepatopancreatic Necrosis Disease (AHPND), a critical issue in shrimp aquaculture despite the application of several control strategies. The use of antibiotics is now restricted due to increasing bacterial resistance and overuse. Silver nanoparticles (AgNPs) have shown potential in shrimp aquaculture, with applications in boosting immunity against certain types of pathogens, promoting growth, and improving survival rates. However, an economically viable solution that protects the organisms has not been found, which is why the search for nanoparticles synthesized with plant extracts is necessary to generate environmentally friendly control strategies. In this study, we synthesized AgNPs from Larrea tridentata extract and administered them orally with feed over a 35-day period. Shrimps fed with AgNP-enriched diets showed a significant increase (p < 0.05) in mRNA expression of immune-related genes (CTL-5, MNK, SR, and GILT), particularly within the first 24–48 h. No significant differences were observed in growth rates, but survival rates in a challenge against V. parahaemolyticus exceeded 85%, higher than the control group. Based on our findings and previous literature, L. tridentata can effectively promote the synthesis of AgNPs and shows potential as an antimicrobial agent, without affecting the growth or survival of treated shrimp.