Biochemical changes and tissue distribution of Enterocytozoon hepatopenaei (EHP) in naturally and experimentally EHP‐infected whiteleg shrimp, Litopenaeus vannamei (Boone, 1931), in India

Abstract

Stunted growth in pond-reared Litopenaeus vannamei was observed in different farms located in Tamil Nadu and Andhra Pradesh, India. No mortality was associated with stunted growth. PCR assay on these samples revealed the presence of Enterocytozoon hepatopenaei (EHP) in stunted shrimp. Tissue distribution of EHP in naturally and experimentally infected shrimp was studied by PCR and histology. Histological examination revealed the presence of EHP in hepatopancreas and gut, but not in other organs. The PCR assay revealed the presence of EHP in all the organs tested in both naturally and experimentally infected shrimp. Healthy shrimp were challenged with E. hepatopenaei by intramuscular injection and oral route, and no mortality was observed in both routes after 30 days post-challenge. Different developmental stages of the microsporidian parasite were observed in the hepatopancreatic epithelial cells. Biochemical parameters such as total protein, albumin, aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase were measured in the haemolymph of naturally and experimentally EHP-infected shrimp. All biochemical parameters mentioned were found to be significantly higher in EHP-infected shrimp when compared to normal shrimp. This is the first report relating AST and ALT levels to EHP infection in naturally and experimentally infected shrimp.

In vitro propagation of tilapia lake virus in cell lines developed from Oreochromis mossambicus

“…The introduction of exotic species has the risk of disease outbreaks caused by the pathogens which are not reported previously in India. Recently, the occurrence of Enterocytozoon hepatopenaei and IMNV has been reported after the introduction of L. vannamei to Indian aquaculture system (Rajendran et al, ; Sahul Hameed et al, ; Santhoshkumar et al, ). Behera et al () reported for the first time the occurrence of TiLV in Nile tilapia farms in India.…”

Effects of dietary n-3HUFA on juvenile white shrimp, Litopenaeus vannamei: Growth, feed utilization, antioxidant enzymes activities and fatty acid compositions

“…ALT and AST are two important indexes, which can reflect the function of liver. Under normal conditions, the activities of transaminases in serum remain low, unless the tissues is damaged or lesions (Nazeri, Farhangi, & Modarres, ; Santhoshkumar et al, ). When the pathological changes occur, the necrosis of tissue cells leads to the release of a large number of transaminases into blood, which would cause the increase of the contents of ALT and AST (Kalhoro et al, ; Li et al, ).…”

Studies on the occurrence of infectious myonecrosis virus in pond‐reared Litopenaeus vannamei (Boone, 1931) in India

“…The tissue samples were also screened for WSSV, IHHNV and EHP by PCR using virus‐ and EHP‐specific primers after extracting DNA from the samples based on published protocols (Lo et al., ; Yoganandhan, Sathish, Murugan, Narayanan, & Sahul Hameed, ; Tang et al. ; Santhoshkumar et al., ).…”

“…A surveillance programme supported by National Fisheries Development Board of ICAR is being carried out to monitor shrimp culture systems throughout the country for emerging diseases in shrimp and fish. As a result of this programme for the past 3 years, the occurrence of Enterocytozoon hepatopenaei in pond‐reared L. vannamei (Rajendran et al., ; Santhoshkumar et al., ) and cyprinid herpesvirus‐2 in goldfish (Sahoo et al., ) has been reported. In our surveillance, the occurrence of infectious myonecrosis virus (IMNV) in pond‐reared L. vannamei has been reported for the first time in India.…”