Experimental transmission of White-Spot Syndrome Virus (WSSV) from crabs to shrimp Penaeus monodon

Abstract

White spot syndrome virus (WSSV) of the black tiger prawn Penaeus rnonodon is a recently discovered baculo-like virus disease which is currently the cause of very serious and widespread losses in the shrimp industry in Thailand and elsewhere in Asia. Three suspected crab carriers of this virus commonly found in shrimp-rearing areas were investigated. These were Sesarma sp., Scylla serrata and Uca pugilator. All these crabs could be infected with WSSV by injection and they sustained heavy viral infections for up to 45 d (confirmed by normal histology, specific in situ DNA hybridization and PCR amplification) without visible signs of disease or mortality. All of them also transferred the disease to P. monodon via water while physically separated in aquarium cohabitation tests. Transfer of the virus to the shrimp was monitored using in situ DNA hybridization and PCR assay at 12 h intervals after cohabitation began. With U. pugilator, WSSV could be detected in the shrimp cohabitants after 24 h using PCR amplification and after 60 h using in situ hybridnation. With S. serrata, the shrimp were positive for WSSV after 36 h using PCR and after 60 h using DNA in situ hybridization. With Sesarrna sp. they were positive after 48 h using PCR and 72 h using in situ hybridization. These laboratory studies demonstrated that crab carriers of WSSV may pose a real threat to cultivated shrimp. However, the studies were carried out in containers with a small volume and with relatively clean sea water as compared to shrimp cultivation ponds. Pond-based studies are now needed to determine whether factors such as pond volume, pond water quality and shrimp and crab behavior can influence the rate and success of transfer.

Preliminary study on haemocyte response to white spot syndrome virus infection in black tiger shrimp Penaeus monodon

“…Thus, they may have included only non-circulating haemocytes. On the other hand, positive WSSV in situ hybridisation results with haemolymph smears of crabs and shrimp have been reported (Kanchanaphum et al 1998). By contrast, our tissue sections clearly showed that free, circulating haemocytes never gave positive in situ hybridisation results for WSSV infection.…”

Pathological changes in Fenneropenaeus indicus experimentally infected with white spot virus and virus morphogenesis

“…At least 18 cultured and/or wild penaeid shrimp (Park et al, 1998), eight caridean species (Pramod-Kiran et al, 2002), seven species of lobster (Rajendran et al, 1999), seven species of crayfish (Edgerton, 2004), 38 crab species (Yoganandhan et al, 2003) six non-decapod crustacean species (Hossain et al, 2001), members of the phyla Chaetognata and Rotifera (Yan et al, 2004), polychaete worms (Supak et al, 2005) and some aquatic insect larva (Ramírez-Douriet et al, 2005) have been found susceptible to the virus. Histopathological observations during WSV infection in brief is available regarding shrimp species such as Penaes monodon (Durand et al, 1997;Wang et al, 1999Wang et al, , 2000Mishra and Shekhar, 2005) Litopenaeus vannamei and Marsupenaeus japonicus (Lu et al, 1997;Lightner et al, 1998;Escobedo-Bonilla et al, 2007;Perez et al, 2005;Pantoja and Lightner, 2003), species of Crabs (Kanchanaphum et al, 1998;Kou et al, 1998) and lobster (Rajendran et al, 1999;Wang et al, 1998;Jiravanichpaisal et al, 2001).…”

Insights into the immune transcriptome of the shrimpLitopenaeus vannamei: tissue-specific expression profiles and transcriptomic responses to immune challenge

“…The response of shrimp to infectious diseases is of particular interest, as disease outbreaks cause large losses to aquaculture and may also threaten wild crustacean populations (10,11,30,37). Shrimp are susceptible to infection by a wide range of pathogens, including parasites, fungi, bacteria, and viruses, but of these agents it is the viruses that pose the greatest threat to shrimp health under farming conditions (33).…”