Analysis of four Echinococcus multilocularis mitogenome sequences from Inner Mongolia, China: supporting the hypothesis that E. sibiricensis is confirmed as the O1 haplotype.

BACKGROUND

Echinococcus multilocularis is a zoonotic parasitic species that causes alveolar echinococcosis (AE), a severe disease affecting both humans and animals. This disease is particularly prevalent in the Northern Hemisphere, especially in northeast Asia, Europe, and North America. Previous studies have often conflated the haplotypes of E. multilocularis from Inner Mongolia, China, and Siberia, Russia. Furthermore, the unique variant identified in Inner Mongolia is of significant importance for elucidating the evolutionary history of E. multilocularis.

METHODS

The four complete mitochondrial genome (mitogenome) sequences obtained were amplified by polymerase chain reaction (PCR): one from an AE patient in Hulunbuir, Inner Mongolia, China, and three from E. multilocularis isolates maintained in gerbils at Academician Chongti Tang's laboratory. Subsequently, these sequences underwent high-throughput sequencing using Illumina technology.

RESULTS

The four mitogenome sequences all span the full length of 13,738 base pair (bp). A phylogenetic analysis was conducted to assess the genetic differences between these sequences and others derived from major E. multilocularis endemic regions globally, with a particular focus on northeast Asia. The results demonstrated that the similarity among the four sequences was 99.24-99.26%. Furthermore, the genetic divergence between sequences originating from Mongolia, Siberia, Russia, and North America was relatively low, indicating a high degree of sequence similarity. The four sequences from Inner Mongolia, China were classified into four haplotypes: O1-O4. Sequencing and genetic analysis confirmed that the previously published E. m. sibiricensis belongs to the O1 haplotype.

CONCLUSIONS

This study clarifies the genetic relationship between E. multilocularis haplotypes in Siberia, Russia, and Inner Mongolia, China, confirming that E. m. sibiricensis is part of the O1 haplotype. The findings strengthen the foundation for molecular epidemiology of AE and underscore the need for international collaboration in monitoring this zoonotic pathogen. Public health strategies can leverage these insights to predict and prevent outbreaks, particularly in endemic regions.