Perkinsus olseni in vitro Isolates from the New Zealand Clam Austrovenus stutchburyi

Abstract

Perkinsus olseni infections are reported at 10%-84% prevalences among Austrovenus stutchburyi clams (cockles) in northern New Zealand coastal waters. However, P. olseni has not yet been propagated in vitro from New Zealand clams. In our sample of A. stutchburyi clams from Mangemangaroa Stream, New Zealand, 24% (8/34) showed low-intensity Perkinsus sp. infections among mantle and gill tissues incubated in alternative Ray's fluid thioglycollate medium (ARFTM), and 5% (4/79) showed Perkinsus sp. lesions by histological analyses. Among clams that were screened using a polymerase chain reaction (PCR) assay, 16% (3/19) were positive for Perkinsus sp. DNA. Alternative Ray's fluid thioglycollate medium-enlarged hypnospores from tissues of five infected clams yielded three in vitro Perkinsus sp. isolate cultures that were cloned before sequencing internal transcribed spacer (ITS) regions of their rRNA gene complex. For one isolate, ATCC PRA-205, large subunit (LSU) rRNA and actin genes were also sequenced. All nucleotide sequences from all isolates consistently identified them as P. olseni, as did their in vitro cell cycles and zoosporulation characteristics. All in vitro isolate cultures and their respective monoclonal derivative strains were cryopreserved and deposited for archiving and distribution by the American Type Culture Collection (http://www.atcc.org).

Pathogens in Crassostrea ariakensis and other Asian oyster species: implications for non-native oyster introduction to Chesapeake Bay

“…phylogenies based on the ITS rRNA region. To date, phylogenies that were based on other regions, including the large subunit ribosomal RNA and actin gene sequences, have confirmed results obtained using ITS rRNA , Dungan et al 2007). …”

First report of Perkinsus sp. infecting mangrove oysters Crassostrea rhizophorae from the Brazilian coast

“…showed some similarities with P. beihaiensis infection in Chinese oysters (Moss et al 2008), such as small size, prevalent low-intensity infections, and infection of digestive epithelia. In contrast, epithelia of Japanese clams Ruditapes philippinarum were not typically infected by P. honshuensis or P. olseni , which have nearly exclusive distributions among connective tissues (Dungan et al 2007). However, pathological consequences of infections among C. rhizophorae from northeastern Brazil may have been underestimated due to the low number of heavily infected oysters (1 of 26, 3.85%) that were available for histological analysis.…”

“…The timing and morphological changes throughout the process of zoosporulation and the morphological characteristics of zoospores are all consistent with observations from other Perkinsus spp. (Sunila et al 2001, Casas et al 2002b, Dungan et al 2007, Moss et al 2008.…”

“…Casas et al (2002a) described the first use of molecular biology methods to characterize P. olseni infecting R. decussatus from Spain. Since then, molecular tools have been used to describe and confirm P. olseni infecting several bivalve species such as R. decussatus from the Mediterranean coast of Spain (Elandaloussi et al 2009); R. philippinarum from Italy (Abollo et al 2006), South Korea (Park et al 2005), and China (Zhang et al 2005); Protothaca jedoensis from South Korea (Park et al 2006); Austrovenus stutchburyi from New Zealand (Dungan et al 2007); and Tridacna crocea from Vietnam (Sheppard & Phillips 2008).…”

Infection prevalence and phylogenetic analysis of Perkinsus olseni in Ruditapes philippinarum from East China

“…are spread by inadvertent transportation of infected clams on ships, by importation of untested and unquarantined ornamental clams (Sheppard & Phillips 2008), or by the introduction of exotic clam species for intensive cultivation (Elandaloussi et al 2009). P. olseni infections have been identified in many types of mollusks throughout the world, including carpet shell clams Ruditapes decussatus in Spain (Ordas et al 2001), undulated surf clams Paphia undulata in Thailand (Leethochavalit et al 2004), venus clams Protothaca jedoensis in Korea (Park et al 2006), and cockles Austrovenus stutchburyi in New Zealand (Dungan et al 2007).…”