RECENT STUDIES ON SHRIMP MICROSPORIDIAN INFECTION: ENTEROCYTOZOON HEPATOPENAEI (EHP) AND COTTON SHRIMP DISEASE

Diagnosis of Enterocytozoon hepatopenaei (EHP)

Marine shrimp farms in SE Asia including Vietnam, Thailand, Malaysia, Indonesia and China have increasingly been reporting stocks that exhibit severely retarded growth, and shrimp from these affected ponds were found to be heavily infected with a microsporidium, Enterocytozoon hepatopenaei (EHP). EHP is an intracellular spore-forming parasite; it replicates within the cytoplasmic area of the tubule epithelial cells in the hepatopancreas. There is a need to develop specific, rapid, and sensitive diagnostic methods so that the pathogen can be monitored and management strategies can be developed.

We applied PCR to amplify the 18S rRNA sequence from EHP, generated a digoxigenin-labeled probe to identify the EHP infection within the cells by in situ hybridization, and developed a specific PCR for detecting EHP in shrimp tissues, feces and water.

Diagnosis of cotton shrimp disease

Cotton shrimp disease is another critical microsporidian infection which threatens shrimp aquaculture. It mainly targets striated muscle of shrimp and lead white or opaque patches under the shell.

We collected shrimp samples from the Red Sea-Indian Ocean region and diagnosed to cotton shrimp disease by histopathology. We also developed PCR and in situ hybridization methods based on the 18S rRNA sequence (unpublished).