title: First report of Perkinsus sp. infecting mangrove oysters Crassostrea rhizophorae from the Brazilian coast.
abstract: Protozoan parasites of the genus Perkinsus are considered important pathogens responsible for mass mortalities in several mollusk species worldwide. In the present study we describe for the first time a parasite of the genus Perkinsus infecting the mangrove oyster Crassostrea rhizophorae from the Brazilian coast. Prevalence of this parasite was low in the Pacoti River estuary (Ceará, northeast Brazil) and absent in oysters from southern Brazil. Oyster gill and rectum tissues incubated in Ray's fluid thioglycollate medium (RFTM) revealed the presence of spherical hypnospores (5 to 55 microm diam.). Histological analysis showed the occurrence of typical signet-ring trophozoites and schizonts (3 to 6 microm diam.) infecting connective tissues of several organs and digestive epithelia. PCR assays specific to the genus Perkinsus, followed by cloning and sequencing of the internal transcribed spacer (ITS) region of the ribosomal ribonucleic acid (rRNA) gene complex, confirmed a close phylogenetic relationship between Brazilian Perkinsus sp. and P. beihaiensis infecting Chinese oysters.
authors.affiliation: Instituto de Ciências do Mar, Universidade Federal do Ceará, P.O. Box 52756, Fortaleza, CE, Brazil.
authors.forename: Rachel Costa
authors.initials: RC
authors.lastname: Sabry
authors.forename: Rafael Diego
authors.initials: RD
authors.lastname: Rosa
authors.forename: Aimê Rachel Magenta
authors.initials: AR
authors.lastname: Magalhães
authors.forename: Margherita Anna
authors.initials: MA
authors.lastname: Barracco
authors.forename: Tereza Cristina Vasconcelos
authors.initials: TC
authors.lastname: Gesteira
authors.forename: Patricia Mirella
authors.initials: PM
authors.lastname: da Silva
mesh_terms: D056893:Alveolata / Q000235:genetics / Q000302:isolation & purification*; D000818:Animals; D001267:Atlantic Ocean / Q000453:epidemiology; D001938:Brazil / Q000453:epidemiology; D049896:Crassostrea / Q000166:cytology / Q000382:microbiology*; D010802:Phylogeny; D011529:Protozoan Infections, Animal / Q000453:epidemiology* / Q000469:parasitology