Prevalence of the protozoan Perkinsus spp. in the gills of the pleasure oyster Crassostrea corteziensis from two estuaries in Nayarit, Mexico, was measured. The protozoan was identified by PCR amplification of the internal transcribed spacer (ITS) region of the rDNA of Perkinsus spp. The pathogen was found in 92% of oysters from Boca de Camichín and 77% of oysters from Pozo Chino. ITS sequences characterized from C. corteziensis showed 96–100% similarity to Perkinsus marinus. The most frequent ITS sequence, (GenBank JQ266236) had 100% identity with the ITS locus of P. marinus from New Jersey, Maryland, South Carolina, and Texas, and the second most frequent observed sequence (GenBank JQ266240) was 100% identical to ITS sequences of P. marinus from New... |