Characterization of Cryptocaryon irritans, a parasite isolated from marine fishes in Taiwan

Abstract

The ciliated protozoan parasite Cryptocaryon irritans infecting marine fishes in Taiwan is described. Developmental characteristics and sequences of the ribosomal DNA regions such as part of 18 S, the entire first internal transcribed spacer, and part of 5.8 S of various Taiwan isolates of C. irritans were investigated. A total of 5 isolates was obtained from different fish-host species and localities, the majority from cultured fish species. C. irritans from Taiwan is able to shift its developmental characteristics, i.e. from non-adherent to adherent tomonts, from individualistic to aggregateforming tomonts, from infection of the gills only to infection of the gills and body. Thus, it is not possible to classify strains of C. irritans on the basis of these parameters. Premature tomonts that developed from dead fishes were able to produce theronts that could infect fish host. Isolates from Pingtung and the USA had identical nucleotide sequences while an isolate from Malaysia was identical to an Israel isolate. Percentage variation among pairs of Taiwan isolates showed a higher degree of variation than isolate sequences listed in GenBank. Sequence analysis revealed highly aberrant isolates in Taiwan, and a phylogenetic tree distinguished a marine and a low-salinity variant. C. irritans from marine fishes in Taiwan, therefore, display some characteristics not previously reported. Since manipulation of salinity in brackishwater ponds and marine cage sites is not feasible, there is a need to develop new strategies for the control and prevention of cryptocaryoniasis.

Characterization of Cryptocaryon irritans isolates from marine fishes in Mainland China by ITS ribosomal DNA sequences

“…Cryptocaryon irritans is a holotrichous marine ciliate protozoan that causes the white spot of marine teleosts in temperate and tropical seas (e.g., Burgess and Matthews 1995;Yambot et al 2003). Geographical distribution of the disease includes the Indo-pacific, the Persian Gulf, the Red Sea in Israel, the Atlantic Ocean, and particularly the Caribbean Sea (Colorni and Burgess 1997;Yambot et al 2003).…”

Perbandingan Filogenetik Protein Antigen-I yang Berpotensi Sebagai Calon Diagnostik dan Vaksin terhadap Parasit Cryptocaryon irritans

“…C. irritans adalah spesies tunggal dalam genus Cryptocaryon. Walaupun wujud perbezaan dalam ciri-ciri morfologi, ultrastruktur, perkembangan dan genetik pada pencilan dari lokasi yang berlainan, kesemua pencilan yang dikaji dianggap sebagai C. irritans kerana kepelbagaian yang dilaporkan tidak mengkelompokkan pencilan-pencilan tersebut sebagai spesies yang berbeza (Colorni & Burgess 1997;Colorni & Diamant 1993;Diggles & Adlard 1997;Yambot et al 2003).…”

“…Pelbagai faktor persekitaran seperti suhu dan saliniti serta spesies perumah mempengaruhi jangkitan dan perkembangan C. irritans. Perbezaan dalam parameter persekitaran C. irritans boleh membawa kepada perubahan pada peringkat genetik (Diggles & Adlard 1997;Sun et al 2006;Yambot et al 2003). Perbezaan genotip tersebut sejajar dengan perbezaan ekologi, biologi dan perkembangan strain yang berlainan (Diggles & Adlard 1997).…”

“…Namun demikian, masalah penghasilan antibodi terhadap antigen-i yang spesifik serotip dengan tindakan yang lemah terhadap antigen-i serotip berlainan perlu dicari penyelesaian (Hatanaka et al 2008;Misumi et al 2011). Oleh itu, kajian lanjutan perlu dilakukan untuk memastikan antigen ini dapat menyaring koleksi ikan marikultur yang terjangkit dengan pelbagai serotip kerana perbezaan serotip dan ciriciri morfologi wujud antara C. irritans yang diperoleh dari lokasi yang berlainan (Diggles & Adlard 1997;Sun et al 2006;Yambot et al 2003).…”

Short Term In vitro Culture of Cryptocaryon irritans, a Protozoan Parasite of Marine Fishes

“…Diversified isolates of C. irritans, including a low salinity variant infecting pond-reared sea bream, were characterized recently by Yambot et al (2003).…”