Mitochondrial genome refinement and comparative phylogenetics of Parastrongyloides trichosuri (KNP strain; Nematoda: Strongyloididae) from South Africa

<h4>Background</h4>Parastrongyloides trichosuri Mackerras, 1959 (Nematoda: Strongyloididae) is a facultatively parasitic nematode infecting the common brushtail possum. A previously reported mitochondrial genome (mitogenome) from a Kruger National Park (KNP) isolate (GenBank: NC_028620) is incomplete, lacking the nad3 gene and the noncoding region (NCR), limiting its utility for comparative and phylogenetic studies.<h4>Objectives</h4>This study aimed to reconstruct, annotate, and validate a complete mitogenome of P. trichosuri (KNP strain) to enhance genomic accuracy and phylogenetic resolution within Strongyloididae.<h4>Methods</h4>Whole-genome sequencing data (SRA: ERS056619) were reanalysed. Missing genes, including tRNA-Glu and atp6, were manually curated using BLASTn searches against Rfam v15, while cox3 and nad3 were confirmed through transmembrane topology analysis.<h4>Findings</h4>The reconstructed mitogenome was 13,809 bp long, comprising 12 protein-coding genes, 22 tRNAs, 2 rRNAs, and a 539-bp tandem-repeat NCR. Gene order and structure were consistent with other Strongyloididae mitogenomes. Phylogenetic analysis supported P. trichosuri as a distinct lineage within the family. The annotated sequence has been deposited in the Third Party Annotation database in GenBank (accession No. BK075097).<h4>Main conclusions</h4>This improved mitogenome fills an existing genomic gaps and provides a reliable reference for future comparative, phylogenetic, and evolutionary studies of Strongyloididae.