Molecular Phylogenetics of Species (Nematoda: Trichostrongylidae) from Humans of Mazandaran Province, Iran.

The present study was performed to analyze molecularly the phylogenetic positions of human-infecting species in Mazandaran Province, Iran, which is an endemic area for trichostrongyliasis. DNA from 7 infected stool samples were extracted by using in-house (IH) method. PCR amplification of ITS2-rDNA region was performed, and products were sequenced. Phylogenetic analysis of the nucleotide sequence data was performed using MEGA 5.0 software. Six out of 7 isolates had high similarity with , while the other one showed high homology with registered in GenBank reference sequences. Intra-specific variations within isolates of and amounted to 0-1.8% and 0-0.6%, respectively. species obtained in the present study were in a cluster with the relevant reference sequences from previous studies. BLAST analysis indicated that there was 100% homology among all 6 ITS2 sequences of in the present study and most previously registered sequences of from human, sheep, and goat isolates from Iran and also human isolates from Laos, Thailand, and France. The ITS2 sequence of exhibited 99.4% homology with the human isolate of from Thailand, sheep isolates from New Zealand and Iran, and cattle isolate from USA.