Shrimp aquaculture is the most promising food producon sector providing protein rich supplements for human consumpon. It has changed from extensive, tradional, small-scale pracces to an intensive, scienﬁc, large scale global industry in the last three decades.The intensive shrimp aquaculture is associated with serious disease outbreaks that are responsible for the producon loss either due to the reducon of growth rate or mortality caused by various pathogenic microorganisms.
Pathogen control in aquac animals is highly challenging as they are transmied rapidly through water unlike pathogens of terrestrial animals. High stocking density is one of the major factors aiding easy transmission of pathogens.
Out of the various infecous diseases that have caused devastang collapses of the shrimp industry, Hepatopancreac Microsporidiosis (HPM) caused by Enterocytozoon hepatopanaei (EHP) is the most diﬃcult to control as there is no eﬀecve treatment available with the shrimp farmers and very diﬃcult to eradicate once the spores get seled in the ponds.
The main clinical sign EHP is growth retardaon, which leads to an
increased variability in size. In a more advanced stage, EHPinfected
shrimp typically display so shells, lethargy, reducedfeed intake, and empty midgut. EHP is currently diagnosed through histological examinaon, in situ hybridizaon and PCR. EHP is an intracellular microsporidian that replicates
within the cytoplasm of the aﬀected tubule epithelial
cells in the hepatopancreas.
Histology of infected issues reveals several developmental stages, including
basophilic inclusion bodies within the cytoplasm of the hepatopancrease
EHP primarily infects the tubule epithelial cells of hepatopancreas via a highly specialized polar tube which it extends from its cell wall into the epithelial cell forming a pore in the host cell. Through this pore via the specialized polar tube it injects its sporoplasm into the host cells. The sporoplasm now diﬀerenates into meronts inside the host cytoplasm then
sporonts and lastly mature spores that are ﬁnally released ready to infect
other healthy cells.
Host cell Rupture of host cell and release of spores Sporogon differentiation/maturation Parasitophorous vaculoe full of spores Merogony proliferation Exospore Nucleus Endospore Proliferative forms Spore Anchoring disc Polar tube Polar tube coil Posterior vacuole Mode of Transmission Shed in ponds Ingestion Co-habitation DNA Host cell
Primary sites of infection: Hepatopancreas Spore Germination Sporoplasm polar ﬁlament extrusion REHPAIRO is a safe biotechnological innovaon for controlling the EHP infecon and increasing the eﬃciency of highquality protein in aqua feeds.
It not only enhances production, but also helps to improve the quality which positively inﬂuences processing characteriscs. It also addresses the environmental concerns of eutrophicaon and polluon associated with excess nutrient waste.
REHPAIRO also opmizes the ulizaon of protein depending on the opmal dietary amino acid proﬁle of a species for the protein synthesis. If the amino acid proﬁle is poorly correlated to the requirement of the shrimp, then it leads to lower retenon of synthesized protein. REHPAIRO improves the retenon of the synthesized protein from the feed leading to higher growth rates and low protein turnover.
Mechanism for EHP Reducon
• The phyto-acve components of REHPAIRO prevents adhesion of EHP spore wall and the tubule epithelial cells of
• Checks virulence of EHP spores by killing them outside the cell or in the gut lumen
• Interrupts the polar tube extension to the host cell by digesng the polar tube components, thereby blocking the
• Enhances the recovery of shrimp digesve system and improves the health condion
EHP – Host Cell Mechanism
• Assists in acvang the funcon of hepatopancreas
• Aids in control of EHP/ HPM / WFS in shrimps
• Helps in achieving faster growth and body weight gain