Incorrect sequencing and taxon misidentification: an example in the Trichinella genus.

Molecular analyses such as polymerase chain reaction (PCR) and sequencing are very useful for taxon identification, especially when morphological characters useful for identifying taxa are lacking. However, the use of molecular tools can be the source of taxon misidentification if they are not correctly applied and the results are not critically evaluated and compared with the literature and GenBank data. We describe a case of misidentification of a taxon of the genus Trichinella due to sequencing mistakes, lack of reference material and selection of a single molecular marker. A Trichinella sp. isolate from an Iranian wild boar (Sus scrofa) was identified as belonging to the Nearctic species Trichinella murrelli, through the molecular analysis of the 5S rRNA intergenic spacer region. A successive molecular identification of the same isolate was performed by the International Trichinella Reference Centre in Rome, Italy, using the 5S rRNA intergenic spacer region, the LSU rDNA expansion segment five, and the internal transcribed spacers 1 and 2. According to these analyses, the Iranian isolate belonged to Trichinella britovi, a Palaearctic species already described in Iran.