Nematode DNAs was purified using ExoSAP-ITTM PCR Product Cleanup Reagent (Thermo Fisher Scientific, USA) prior to sequence alignment.
Purified DNA samples were sequenced using ABI3730XL Sanger sequencing device and BigDye Terminator v3.1 Cycle sequencing kit (Applied Biosystems, Foster City, CA) in Macrogen laboratory in the Netherlands.
The sequences were deposited into the GenBank database and compared with those of the other P. vulnus populations available at the GenBank sequence database using the BLAST homology search tool (