Molecular identification of the advanced third-stage larvae (ADV L(3)) of Gnathostoma lamothei in Tabasco, Mexico.

Advanced third-stage larvae (ADV L(3)) of Gnathostoma spp. were collected from the muscle tissue of three species of freshwater fish (i.e., Gobiomorus dormitor, Petenia splendida, and Parachromis managuensis) in Swamps of Centla, Tabasco, Mexico. Nine sequences of the ITS2 of the ribosomal DNA of Gnathostoma spp. were compared with sequences obtained from GenBank for G. binucleatum, G. lamothei, G. miyazakii, G. spinigerum, and G. turgidum. Sequences of the ADV L(3) from P. splendida (Isla Chinal), P. managuensis (Isla Chinal), and of two of the six larvae collected from G. dormitor (Tres Brazos), were identical to that of G. binucleatum (GenBank). Sequences from the other four larvae from G. dormitor (Tres Brazos) are identical to the sequence of G. lamothei (GenBank). This is the first record of the intermediate host of G. lamothei. The only species documented to cause human gnathostomiasis in the Americas is G. binucleatum. Our finding of G. binucleatum, and G. lamothei parasitizing the commercially important fish species, G. dormitor in Centla swamps, indicates the possibility of G. lamothei causing human gnathostomiasis in Mexico as well.