We developed a qPCR assay based on the β-tubulin gene sequence for the shrimp microsporidian parasite Enterocytozoon hepatopenaei (EHP). This assay reacted with the hepatopancreas (HP) of EHP-infected shrimps, and the highest copy numbers were found in HP and feces samples from Southeast Asian countries (106–108 copies mg−1), while HP samples from Latin America, Artemia, and EHP-contaminated water showed lower amounts (101–103 copies mg−1 or mL−1 of water). No false positive was found with the normal shrimp genome, live feeds, or other parasitic diseases. This tool will facilitate the management of EHP infection in shrimp farms.
White feces syndrome (WFS) is an emerging and poorly described disease characterized by the presence of floating white fecal strings in shrimp (Penaeus monodon and P. vannamei) grow-out ponds. WFS has been associated with several pathogens, including Enterocytozoon hepatopenaei. This association is based on the fact that in areas where E. hepatopenaei has been reported, there was also a high WFS prevalence. E. hepatopenaei is an emerging pathogen that has affected cultured shrimp in Indonesia, Vietnam, China, Thailand, and India. In 2016, we reported the presence of E. hepatopenaei in farmed P. vannamei in Venezuela. In this study, we describe the first case of WFS in Venezuela associated with E. hepatopenaei. The white fecal strings and shrimp displaying white feces along the gastrointestinal tract observed in this study were similar to the gross signs found in WFS-impacted P. vannamei in SE Asian countries. Furthermore, we describe a strong association between WFS and E. hepatopenaei in the samples obtained from Venezuela and Indonesia. Quantification of E. hepatopenaei in WFS-affected ponds, ponds with a history of WFS, and ponds with no WFS showed that E. hepatopenaei loads were significantly higher in WFS-affected ponds. Furthermore, these findings constitute the first report of WFS being associated with E. hepatopenaei in farmed shrimp in Latin America. Additionally, we propose that the gross signs of WFS such as floating whitish fecal strings can be used as an indicator of the presence of E. hepatopenaei in countries where E. hepatopenaei is endemic.
B, Asdani Kartamiharja UK. Isolation of infectious spleen and kidney necrosis virus from farmed Asian seabass in Indonesia and effect of fish size on its virulence. Aquac Res.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.