title: Laboratory cohabitation challenge model for shrimp hepatopancreatic microsporidiosis (HPM) caused by Enterocytozoon hepatopenaei (EHP).
abstract: BACKGROUND
  Enterocytozoon hepatopenaei (EHP) causes hepatopancreatic microsporidiosis (HPM) in shrimp. It is probably endemic in Australasia and was first characterized and named from the giant or black tiger shrimp Penaeus monodon from Thailand in 2009. Later, it was also found to infect exotic Penaeus vannamei imported for cultivation in Asia. HPM is not normally associated with shrimp mortality, but information from shrimp farmers indicates that it is associated with significant growth retardation that is not clearly noticeable until 2-3 months of cultivation. In order to study modes of HPM transmission and to test possible control measures, a laboratory challenge model was needed that would mimic the mode of infection in shrimp ponds.
  
  
  RESULTS
  We describe successful transmission in a cohabitation model with natural E. hepatopenaei (EHP)-infected shrimp in closed, perforated plastic containers placed in aquaria together with free-swimming, uninfected shrimp. After a period of 14 days all the free-swimming shrimp tested positive by PCR (approximately 60% with heavy infections evident by 1-step PCR positive test results) and gave positive histological and in situ hybridization results for E. hepatopenaei (EHP) in the hepatopancreas.
  
  
  CONCLUSIONS
  A laboratory cohabitation model for studying E. hepatopenaei (EHP) has been developed and used to confirm that E. hepatopenaei (EHP) can be directly transmitted horizontally among shrimp via water. The model will facilitate studies on methods to prevent the E. hepatopenaei (EHP) transmission.
authors.affiliation: Shrimp-pathogen interaction (SPI) laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Yothi office, Bangkok, 10400, Thailand.|Center of Excellence for Shrimp Molecular Biology and Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.
authors.forename: Paul Vinu
authors.initials: PV
authors.lastname: Salachan
authors.affiliation: Center of Excellence for Shrimp Molecular Biology and Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.|Department of Biochemistry, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.
authors.forename: Pattana
authors.initials: P
authors.lastname: Jaroenlak
authors.affiliation: Center of Excellence for Shrimp Molecular Biology and Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.|Department of Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.
authors.forename: Siripong
authors.initials: S
authors.lastname: Thitamadee
authors.affiliation: Center of Excellence for Shrimp Molecular Biology and Biotechnology, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.|Department of Biochemistry, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.
authors.forename: Ornchuma
authors.initials: O
authors.lastname: Itsathitphaisarn
authors.affiliation: Shrimp-pathogen interaction (SPI) laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Yothi office, Bangkok, 10400, Thailand. kallaya@biotec.or.th.
authors.forename: Kallaya
authors.initials: K
authors.lastname: Sritunyalucksana
mesh_terms: D000818:Animals; D021862:Enterocytozoon / Q000502:physiology*; D043143:Hepatopancreas / Q000469:parasitology*; D006790:Host-Parasite Interactions; D033561:Penaeidae / Q000469:parasitology*; D016133:Polymerase Chain Reaction
keywords: Cohabitation assay; Enterocytozoon hepatopenaei; Penaeus vannamei; Shrimp microsporidian