Monitoring of infections by Protozoa of the genera Nematopsis, Perkinsus and Porospora in the smooth venus clam Callista chione from the North-Western Adriatic Sea (Italy)

Perkinsus is the pathogen responsible for mass mortality of the Manila clam Ruditapes philippinarum. Perkinsus sp. isolated from Manila clams collected in Korean waters was assayed by polymerase chain reaction (PCR) to determine its phylogenetic affinity with other congeneric species. Regions of rRNA of Perkinsus sp. isolated from clam haemolymph were cloned and sequenced. Sequences of a non-transcribed spacer (NTS), internal transcribed spacers (ITS 1, 2) and 5.8S rRNA genes were compared to those available from other Perkinsus species. The NTS sequence of Korean Perkinsus was approximately 99.9 to 100% similar to that of P. atlanticus and 98.06 to 98.15% and 73.05 to 73.14% similar to those of P. olseni and P. marinus, respectively. The ITS 1, 5.8S rRNA and ITS 2 sequences of Korean Perkinsus showed 100% similarity to P. atlanticus and Perkinsus sp. reported from Japan. The ITS-5.8S rRNA sequences of Korean Perkinsus were 99.86 and 93.73% similar to those of P. olseni and P. marinus, respectively. The sporulation pattern and morphology of the Korean Perkinsus were very similar to those of P. atlanticus. Our data suggest that the Perkinsus sp. isolated from clams in Korean waters is P. atlanticus, which is currently synonymous with P. olseni reported from Australia. By considering that P. olseni has taxonomic priority, Korean Perkinsus sp. is accepted as P. olseni (atlanticus). KEY WORDS: NTS · ITS · 5.8S rRNA · Perkinsus olseni (atlanticus) · Ruditapes philippinarum · Taxonomy · Korea Resale or republication not permitted without written consent of the publisherDis Aquat Org 66: [255][256][257][258][259][260][261][262][263] 2005 P. qugwadi in the Japanese scallop Patinopecten yessoensis on the west coast of Canada (Blackbourn et al. 1998), and P. andrewsi in the Baltic clam Macoma balthica (Coss et al. 2001) and P. chesapeaki in the softshell clam Mya arenaria (McLaughlin et al. 2000), both in Chesapeake Bay, USA. Casas et al. (2004) recently reported a new species of Perkinsus, P. mediterraneus, from the European flat oyster Ostrea edulis from the Balearic Islands in the Mediterranean Sea.Unidentified Perkinsus species have been isolated from Ruditapes philippinarum along the coasts of Korea and Japan (Choi & Park 1997, Choi et al. 1998, Hamaguchi et al. 1998, Park & Choi 2001, as well as along the north-eastern coast of China, in the Yellow Sea (Liang et al. 2001). Hamaguchi et al. (1998) analysed the nucleotide sequences of 2 internal transcribed spacers (ITS 1 and ITS 2) and 5.8S rRNA of Perkinsus isolated from clams in Kumamoto and Hiroshima, Japan. ITS sequences of Perkinsus from Japanese clams were almost identical to those of P. atlanticus and P. olseni, suggesting that Perkinsus isolated from clams in Japan may be conspecific with, or closely related to P. atlanticus in European waters. Size and microscopic features of hypnospores and trophozoites of Perkinsus isolated from the Manila clam in Korea were very similar to those of P. atlanticus (Park & Choi 2001), suggesting that Perkinsus ...

Section: Discussionmentioning

confidence: 99%

Use of molecular markers for species identification of Korean Perkinsus sp. isolated from Manila clams Ruditapes philippinarum

Park

Park²,

Lee³

et al. 2005

“…do not fit in either the dinoflagellate or the apicomplexa phyla, and created the new phylum Perkinsozoa. In Europe, the occurrence of Perkinsus-like parasites has been reported in various bivalve species from Italy (da Ros & Canzonier 1985, Ceschia et al 1991, Canestri-Trotti et al 2000 and France (Goggin 1992). In Spain, they have been detected in bivalves from Andalucía (South Atlantic coast) (Villalba & Navas 1988, Navas et al 1992, Cataluña (NE Mediterranean coast) (Sagristà et al 1991, Santmartí et al 1995, Galicia (NW Atlantic coast) (Figueras et al 1992) and Asturias (North Atlantic coast) (Cigarría et al 1997).…”

Section: Introductionmentioning

confidence: 97%

Study of perkinsosis in the carpet shell clam Tapes decussatus in Galicia (NW Spain). I. Identification of the aetiological agent and in vitro modulation of zoosporulation by temperature and salinity

Casas¹,

Villalba²,

Reece³

2002

127

126

Morphological characters of zoosporulation stages and DNA sequence of the internal transcribed spacer (ITS) region and the small subunit ribosomal RNA (SSU rRNA) gene confirmed that the aetiological agent of perkinsosis in the clam Tapes decussatus from Galicia (NW Spain) was Perkinsus atlanticus Azevedo, 1989. In vitro modulation by temperature and salinity of the zoosporulation of the parasite was studied. The optimum temperature range for zoosporulation was 19 to 28°C. The temperature range allowing zoosporulation in vitro was 15 to 32°C, which is broader than previously reported (24 to 28°C) for P. atlanticus, and strongly suggests that zoospores can be produced in Galician Rías, where temperature ranges from 10 to 22°C. Prezoosporangia held at 10°C for 2 mo (similar to winter conditions in Galician waters) gave rise to viable zoospores after they were transferred to higher temperatures. This suggests that prezoosporangia could overwinter and zoosporulate in the next spring. Zoospores could survive for up to 22 and 14 d at 28 and 10°C, respectively. The optimum salinity range for zooporulation was 25 to 35 ‰. Zoospore production was abruptly reduced as salinity decreased. The lowest salinity at which zoosporulation was observed was 10 ‰. The effectiveness of different chlorine concentrations and exposure lengths to kill prezoosporangia and zoospores was tested. No survival of free zoospores, free prezoosporangia and prezoosporangia included in gill tissue was observed after incubation for 1 h with 50, 200 and 3000 ppm of chlorine, respectively.

“…The occurrence of Perkinsus-like organisms in the Mediterranean Sea has been documented in Ostrea edulis, Crassostrea gigas, Tapes decussatus, T. philippinarum, Venerupis aurea, Venus verrucosa, Callista chione, Cerastoderma edule, Mytilus galloprovincialis, Chamelea gallina and Musculista senhousia from Italian coastal waters (da Ros & Canzonier 1985, Ceschia et al 1991, Berilli et al 1998, Canestri-Trotti et al 1999, 2000a, and in bivalves from the French Mediterranean coasts (Goggin 1992), but none of those studies identified the parasite to species level.…”

Section: Resale or Republication Not Permitted Without Written Consenmentioning

confidence: 99%

“…P. atlanticus is the only species of the genus identified along the European coasts to date. It has been found in T. decussatus from the Iberian Peninsula: Algarve, South Portugal (Azevedo 1989), Huelva, South Spain (de la Herrán et al 2000) and Galicia, NW Spain (Robledo et al 2000, Casas et al 2002a) and in T. philippinarum from Cataluña (NE Spain) (Sagristà et al 1996).The occurrence of Perkinsus-like organisms in the Mediterranean Sea has been documented in Ostrea edulis, Crassostrea gigas, Tapes decussatus, T. philippinarum, Venerupis aurea, Venus verrucosa, Callista chione, Cerastoderma edule, Mytilus galloprovincialis, Chamelea gallina and Musculista senhousia from Italian coastal waters (da Ros & Canzonier 1985, Ceschia et al 1991, Berilli et al 1998, Canestri-Trotti et al 1999, 2000a, and in bivalves from the French Mediterranean coasts (Goggin 1992), but none of those studies identified the parasite to species level.Cases of infection by Perkinsus-like organisms were observed in the tissues of the European flat oyster Ostrea edulis cultivated in the Balearic Islands, Mediterranean Sea. This article describes the morphological characteristics of different life stages and DNA sequences of the rRNA complex of the oyster parasite from Balearic Islands, and identifies a new species of the genus Perkinsus, P. mediterraneus n. sp.…”

mentioning

confidence: 99%

Perkinsus mediterraneus n. sp., a protistan parasite of the European flat oyster Ostrea edulis from the Balearic Islands, Mediterranean Sea

Casas¹,

Grau²,

Reece³

et al. 2004

A new species, Perkinsus mediterraneus, a protistan parasite of the European oyster Ostrea edulis (L.), farmed along the coast of the Balearic Islands, Mediterranean Sea, is described. Morphological examinations with light and transmission electron microscopy, DNA sequenceanalysis and enlargement in Ray's fluid thioglycollate medium (RFTM) confirmed that this parasite belongs to the genus Perkinsus. Specific morphological and genetic characteristics indicated that it should be considered a new species in the genus. Sequencing of the small subunit ribosomal (ssu rRNA) gene confirmed that the parasite belongs to the genus Perkinsus, and sequences of the internal transcribed spacer (ITS) were distinct from any Perkinsus ITS sequences previously published and/or deposited in the GenBank. Phylogenetic analysis revealed that the ITS sequences of the new species formed a monophyletic group comprising a sister clade to the P. atlanticus/olseni group. In addition, morphological differences were observed between the new species and the other described Perkinsus spp.. After incubation in RFTM for 1 wk, the prezoosporangium had reached an extremely large size (97.4 ± 1.99 µm) (mean ± SE), and after 2 wk incubation had again almost doubled in size (167.1 ± 8.09 µm). The discharge-tube length was one sixth the diameter of the zoosporangium, i.e. a ratio of 17.36:97.38, the lowest ratio observed for any Perkinsus species. At the ultrastructural level, zoosporangia and zoospores exhibited some differences compared to other Perkinsus species.KEY WORDS: Perkinsus mediterraneus n. sp. · Ostrea edulis · Oyster parasite · Ultrastructure · Zoosporulation · ssu rRNA gene · Internal transcribed spacer · Perkinsus atlanticus Resale or republication not permitted without written consent of the publisherDis Aquat Org 58: [231][232][233][234][235][236][237][238][239][240][241][242][243][244] 2004 that Perkinsus species are dinoflagellates, or are closely related to them. Other studies have placed the genus Perkinsus within the alveolates, in a new phylum Perkinsozoa, together with the phyla Dinoflagellata, Apicomplexa and Ciliophora (Norén et al. 1999).To date, the genus Perkinsus has comprised 6 species: P. marinus in the eastern oyster Crassostrea virginica (Mackin et al. 1950) along the Atlantic and Gulf coasts of the USA, P. olseni in the blacklip abalone Haliotis ruber from Australia (Lester & Davis 1981), P. atlanticus (Azevedo 1989) in the carpet-shell clam Tapes decussatus from the Iberian Peninsula, P. qugwadi in the Japanese scallop Patinopecten yessoensis ) from British Columbia, Canada, Perkinsus chesapeaki (McLaughlin et al. 2000) in the softshell clam Mya arenaria from Chesapeake Bay, USA, and P. andrewsi (Coss et al. 2001b) in Macoma balthica from Delaware Bay.In European waters, Perkinsus-like organisms were detected in the clam Tapes decussatus and the flat oyster Ostrea edulis in 1978 (da Ros & Canzonier 1985). P. atlanticus is the only species of the genus identified along the European coasts to date. It has...