A plant-based heat shock protein inducing compound modulates host–pathogen interactions between Artemia franciscana and Vibrio campbellii

• We tested the effect of Hsp inducer Tex-OE® on Artemia–Vibrio interaction.
• Pretreatment exposure of Tex-OE® enhanced resistance of Artemia against Vibrio.
• Continuous exposure interfered microbial communities and adversely affects Artemia.
• Tex-OE® can be an ideal disease control tool in aquaculture system.
• The delivery of such compound in an open culture system should be made with care.

Induction of heat shock proteins (e.g. Hsp70) has been considered as a potential disease control and health management strategies in aquaculture. Recently, the compound Tex-OE®, a patented extract from the skin of the prickly pear fruit, Opuntia ficus indica, was reported to enhance the production of Hsp70 in fish and shrimp tissues without any adverse effect, protecting the animals against various abiotic stressors. Most of the studies on this compound primarily focused on the positive effects at the level of the host while the effects on the microorganisms in the culture environment were often overlooked. In our study, we aimed at evaluating the effect of this compound on the interaction of the host brine shrimp Artemia franciscana with pathogenic Vibrio. Pretreatment of axenically-grown Artemia with Tex-OE® conferred significant protection against V. campbellii in a conventional rearing system. However, continuous exposure of axenniclly-grown Artemia to Tex-OE® in an open system negatively affected their survival. In vitro experiments provided unequivocal evidence that continuous exposure of Tex-OE® modulated the growth and virulence (such as hemolytic and caseinase activity) of V. campbellii. Pretreatment of Vibrio with the compound also increased their virulence in an Artemia challenge assay. Based on the overall results, it can be suggested that the compound Tex-OE® has the potential to be used as a disease control tool in (shrimp) aquaculture systems. However, the possibility that such kind of compounds also modulate the microbial activity cannot be ignored making the outcome dependent on the composition of the standing microbial community.