Differences between the intestinal microbial communities of healthy dogs from plateau and those of plateau dogs infected with Echinococcus

Abstract

Objective: Cystic echinococcosis (CE) represents a profoundly perilous zoonotic disease. The advent of viral macrogenomics has facilitated the exploration of hitherto uncharted viral territories. In the scope of this investigation, our objective is to scrutinize disparities in the intestinal microbiotic ecosystems of canines dwelling in elevated terrains and those afflicted by Echinococcus infection, employing the tool of viral macrogenomics.

Methods: In this study, we collected a comprehensive total of 1,970 fecal samples from plateau dogs infected with Echinococcus, as well as healthy control plateau dogs from the Yushu and Guoluo regions in the highland terrain of China. These samples were subjected to viral macrogenomic analysis to investigate the viral community inhabiting the canine gastrointestinal tract.

Results: Our meticulous analysis led to the identification of 136 viral genomic sequences, encompassing eight distinct viral families.

Conclusion: The outcomes of this study hold the potential to enhance our comprehension of the intricate interplay between hosts, parasites, and viral communities within the highland canine gut ecosystem. Through the examination of phage presence, it may aid in early detection or assessment of infection severity, providing valuable insights into Echinococcus infection and offering prospects for potential treatment strategies.

Keywords: Bacteriophage; Dog; Echinococcus; Intestinal microbial community.

Fig. 1

The diversity of viral species in the 197 libraries. A Species rarefaction curves were generated by applying a logarithmic scale transformation to the raw data using Megan v6.21.16 software. B The accumulation curve illustrates the diversity of viral species in canine metagenomes. Each box plot on the graph represents the richness values of individual samples, with light blue regions indicating the associated 95% confidence intervals

Fig. 2

Statistical analysis of enterovirus communities. A The heatmap was created to display the nucleic acid types, virus families, sampling area groupings, and health status, which were annotated using different colors according to the provided color legend. B The upset plot reflected the number of virus species that are unique or common to each group

Fig. 3

Alpha diversity of enterovirus communities. Prior to comparing viral alpha diversity, the viruses under examination were normalized using Megan. The viral abundance at the family level was quantified using the Shannon index and Simpson index as a measure. The p-value was calculated using the Wilcoxon test. Statistical significance was determined when the p-value was less than 0.05

Fig. 4

Beta diversity of enterovirus communities. To assess viral beta diversity, the viruses were normalized using Megan before conducting the comparisons. To ensure accurate estimation of beta diversity, we employed both Bray–Curtis and Jaccard metrics. Both analyses conducted in (A and C) employed the Bray–Curtis index to assess beta diversity. The Jaccard index is used in (B and D) to analyze beta diversity. Statistical significance was determined when the p-value was less than 0.05. A value of R greater than 0 indicated differences between the groups. Statistical significance was determined when the p-value was less than 0.05

Fig. 5

Phylogenetic relationship of the order Caudovirales. A Bayesian inference tree was generated based on the complete amino acid sequences of TERL (Terminase Large Subunit) from other members of the Caudovirales order. In the provided data, the sequences obtained from this study are represented by the color red. Each scale bar indicates the amino acid substitutions per site

Fig. 6

Phylogenetic relationship of Microviridae. Bayesian inference trees were constructed using the complete amino acid sequences of MCP (Major Capsid Protein) from the entire Microviridae family. In the provided data, the sequences obtained from this study are represented by the color blue. Each scale bar indicates the amino acid substitutions per site