Susceptibility to Taura Syndrome Virus of Some Penaeid Shrimp Species Native to the Gulf of Mexico and the Southeastern United States

Abstract

Experimental studies demonstrated that Penaeus setiferus, but not Penaeus aztecus or Penaeus duorarum, could be killed by Taura syndrome virus (TSV). However, specimens of P. setiferus that survived infection and both P. aztecus and P. duorarum at least 79 days postexposure that did not demonstrate gross signs of infection were shown to harbor virus by bioassay using Penaeus vannamei, a highly susceptible target host. Consequently, all three of those penaeids native to the southeast United States can serve as carriers or reservoir hosts of TSV without necessarily exhibiting disease. Infections in P. setiferus took longer to cause mortality than in P. vannamei and killed a smaller percentage of that host. Also, histological lesions diagnostic of TSV infection were not always evident in sectioned tissue of infected P. setiferus, and they generally were more conspicuous during Days 4-7 postexposure compared with lesions that also occurred at both earlier and later days in tissues of P. vannamei. Infections could be produced by injection, ingestion, and incorporation of the infective material into dietary brine shrimp. There appeared to be a difference in susceptibility to TSV disease by different stocks of P. setiferus, but different experiments produced conflicting evidence regarding a relationship between age and predilection to mortality. Large and small specimens of equal-aged shrimp2 succumbed similarly to TSV infections for both P. vannamei and P. setiferus. The nonnative species P. chinensis demonstrated a high susceptibility to experimental TSV disease.

Taura syndrome virus (TSV) lesion development and the disease cycle in the Pacific white shrimp Penaeus vannamei

“…In this per os study, peak mortality occurred on Day 4, whereas previous TSV per OS infectivity studies have reported peak mortalities on Days 5 or 6 , Lotz 1997, Overstreet et al 1997. With injection-mediated TSV studies, the time frame to peak mortality is even shorter, occurring within 2 to 3 d post-injection , Hasson 1998).…”

Genomic Similarity of Taura Syndrome Virus (TSV) between Taiwan and Western Hemisphere Isolates.

“…The possibility that TSV was an indigenous species in Taiwan is remote. A highly TSV-susceptible species particularly P. chinensis (Overstreet et al, 1997) had been introduced and cultured in Taiwan prior to known outbreaks but no Taura or similar syndrome was reported. Besides, based on the previous documents the diseased shrimp sampled before 1998 showed viral particles with bacilliform instead of icosahedral shape (Chen et al, 1989;Wang et al, 1995;Wang et al, 1997;Zhan and Wang, 1998;Wang and Chang, 2000).…”

“…The fact that P. chinensis, reared from Korean stock, can be experimentally infected with TSV illustrates that a virus from the western hemisphere could potentially infect commercially impor tant shrimp from Asia, if given the opportunity (Overstreet et al, 1997). Urgent and strict quarantine is advised to prevent dissemination of TS to other areas in the Asia.…”

Differences in the susceptibility of some penaeid prawn species to gill-associated virus (GAV) infection

“…Bell & Lightner (1987) also reported less rapid development of histopathological lesions in larger L. stylirostris infected with IHHNV. Taura syndrome virus (TSV) has been reported to be highly pathogenic for L. vannamei and Fenneropenaeus chinensis (also called Penaeus chinensis), less pathogenic for L. stylirostris and Litopenaeus setiferus (also called Penaeus setiferus) and infectious, but nonpathogenic, for F. duorarum and F. aztecus (Brock et al 1995, Overstreet et al 1997. Lotz (1997) found no correlation between size and susceptibility of L. vannamei to TSV infection.…”