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.ResultsWe 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.ConclusionsA 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.
Highlights
Enterocytozoon hepatopenaei (EHP) causes hepatopancreatic microsporidiosis (HPM) in shrimp
In contrast to E. hepatopenaei (EHP) that does not cause any obvious gross signs of infection, A. penaei infections are characterized by a milky white appearance in the usually translucent musculature of the shrimp abdominal segments, sometimes referred to as “cotton shrimp disease”
Preliminary PCR screening All samples of 10 shrimp from all batches of naïve shrimp tested gave negative results by nested PCR analysis for E. hepatopenaei (EHP)
Summary
Enterocytozoon hepatopenaei (EHP) causes hepatopancreatic microsporidiosis (HPM) in shrimp. Two species of microsporidia have been reported so far as pathogenic to cultivated Penaeus monodon and P. vannamei in Thailand These are Agmasoma penaei [1] and Enterocytozoon hepatopenaei (EHP) [2, 3]. Since some fish species in Thailand gave PCR positive test results for A. penaei in Thailand [17, 18] a successful control strategy was devised that consisted of excluding fish (suspected to be intermediate hosts) from shrimp hatcheries and farms. Because of this practice, the prevalence of cotton shrimp disease (A. penaei infections) in cultivated shrimp in Thailand is very low.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
