A novel Eimeria species found in the marbled polecat (Vormela peregusna).

There are no known coccidian parasites reported from the marbled polecat (Vormela peregusna; IUCN Vulnerable), a mustelid found in southeastern Europe and western Asia. There are eleven Eimeria species documented in other mustelids. This study reports a complete mitochondrial genome (mtDNA) from Eimeria species found in marbled polecat. Intestinal samples from seven nature-killed or road-killed individuals (collected 2020-2023 in Xinjiang, China) were subjected to genomic DNA extraction. cox1 nested PCR screening revealed Eimeria infection in 3/7 hosts. Full mitochondrial genome amplification using five overlapping primer pairs yielded a 6179 bp sequence (GenBank PV393175). This mtDNA exhibits classic apicomplexan features: three protein-coding genes (cytb, cox1and cox3), fragmented rRNAs, and no tRNAs. The mtDNA shows high A + T bias (64.49 %). Phylogenetically, Eimeria isolate in marbled polecat was clustered with Eimeria mephitidis (bootstrap = 100 %) yet displayed significant mitogenomic divergence (only 97.65 % sequence identity), particularly in cox3 (95.11 % vs. intraspecific minimum identity 95.50 %). Combined with mtDNA arrangement, significant genetic divergence and host association, we characterized a novel mitochondrial genome from an Eimeria species.