title: 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.
authors.affiliation: OIE Reference Laboratory for WTD, Department of Zoology, C. Abdul Hakeem College, Melvisharam, Tamil Nadu, India.
authors.forename: S
authors.initials: S
authors.lastname: Santhoshkumar
authors.affiliation: OIE Reference Laboratory for WTD, Department of Zoology, C. Abdul Hakeem College, Melvisharam, Tamil Nadu, India.
authors.forename: S
authors.initials: S
authors.lastname: Sivakumar
authors.affiliation: Biomolecules Division, School of Biosciences and Technology, VIT University, Vellore, Tamil Nadu, India.
authors.forename: S
authors.initials: S
authors.lastname: Vimal
authors.affiliation: OIE Reference Laboratory for WTD, Department of Zoology, C. Abdul Hakeem College, Melvisharam, Tamil Nadu, India.
authors.forename: S
authors.initials: S
authors.lastname: Abdul Majeed
authors.affiliation: OIE Reference Laboratory for WTD, Department of Zoology, C. Abdul Hakeem College, Melvisharam, Tamil Nadu, India.
authors.forename: G
authors.initials: G
authors.lastname: Taju
authors.affiliation: Department of Aquatic Animal Health Management, College of Fishery Science, S.V.V. University, Mutukur, Andhra Pradesh, India.
authors.forename: P
authors.initials: P
authors.lastname: Haribabu
authors.affiliation: Fisheries Research and Extension Centre, Tamil Nadu Fisheries University, Chennai, Tamil Nadu, India.
authors.forename: A
authors.initials: A
authors.lastname: Uma
authors.affiliation: OIE Reference Laboratory for WTD, Department of Zoology, C. Abdul Hakeem College, Melvisharam, Tamil Nadu, India.
authors.forename: A S
authors.initials: AS
authors.lastname: Sahul Hameed
mesh_terms: D000818:Animals; D017756:Aquaculture; D021862:Enterocytozoon / Q000502:physiology*; D007194:India; D033561:Penaeidae / Q000254:growth & development / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D014018:Tissue Distribution
keywords: 
  Enterocytozoon hepatopenaei
  ; 
  Litopenaeus vannamei
  ; PCR assay; biochemical analysis; experimental infection; histology