The Impact of Mycobacterium avium subsp. paratuberculosis on Intestinal Microbial Community Composition and Diversity in Small-Tail Han Sheep

Abstract

Paratuberculosis (PTB), primarily caused by Mycobacterium avium subsp. paratuberculosis (MAP), is a chronic infection that affects ruminants and is difficult to prevent, diagnose, and treat. Investigating how MAP infections affect the gut microbiota in sheep can aid in the prevention and treatment of ovine PTB. This study examined fecal samples from eight small-tail Han sheep (STHS) at various stages of infection and from three different field areas. All samples underwent DNA extraction and 16S rRNA sequencing. Among all samples, the phyla p. Firmicutes and p. Bacteroidota exhibited the highest relative abundance. The dominant genera in groups M1-M6 were UCG-005, Christensenellaceae_R-7_group, Rikenellaceae_RC9_gut_group, Akkermansia, UCG-005, and Bacteroides, whereas those in groups A-C were Christensenellaceae_R-7_group, Escherichia-Shigella, and Acinetobacter, respectively. The microbial community structure varied significantly among groups M1-M6. Specifically, 56 microbiota consortia with different taxonomic levels, including the order Clostridiales, were significantly enriched in groups M1-M6, whereas 96 microbiota consortia at different taxonomic levels, including the family Oscillospiraceae, were significantly enriched in groups A-C. To the best of our knowledge, this is the first study to report that MAP infection alters the intestinal microbiota of STHS. Changes in p. Firmicutes abundance can serve as a potential biomarker to distinguish MAP infection and determine the infection stage for its early diagnosis. Our study provides a theoretical basis for the treatment of PTB by regulating the intestinal microbiota, including p. Firmicutes.

Keywords: China; Mycobacterium avium subsp. paratuberculosis; high-throughput sequencing; microbial population; small-tail Han sheep.

Figure 1

Two-dimensional PCoA plot of groups M1–M6.

Figure 2

(A) Two-dimensional PCoA plot of group A. Blue solid circle (●) (G): MAP-negative samples. Red solid circles (●) (H): MAP-positive samples. (B) Two-dimensional PCoA plot of group B. Red solid circle (●) (P): MAP-negative samples. Blue solid circle (●) (O): MAP-positive samples. (C) Two-dimensional PCoA plot of group C. Red solid circles (●) (W): MAP-negative samples. Blue solid circles (●) (T): MAP-positive samples.

Figure 2

(A) Two-dimensional PCoA plot of group A. Blue solid circle (●) (G): MAP-negative samples. Red solid circles (●) (H): MAP-positive samples. (B) Two-dimensional PCoA plot of group B. Red solid circle (●) (P): MAP-negative samples. Blue solid circle (●) (O): MAP-positive samples. (C) Two-dimensional PCoA plot of group C. Red solid circles (●) (W): MAP-negative samples. Blue solid circles (●) (T): MAP-positive samples.

Figure 3

LDA analysis of groups M1–M6.

Figure 4

(A). LDA analysis of group A. Red rectangle () (G): MAP-negative samples. Green rectangle () (H): MAP-positive samples. (B). LDA analysis of group B. Green rectangle () (P): MAP-negative samples. Red rectangle () (O): MAP-positive samples. (C). LDA analysis of group C. Green rectangle () (W): MAP-negative samples. Red rectangle () (T): MAP-positive samples.

Figure 4

(A). LDA analysis of group A. Red rectangle () (G): MAP-negative samples. Green rectangle () (H): MAP-positive samples. (B). LDA analysis of group B. Green rectangle () (P): MAP-negative samples. Red rectangle () (O): MAP-positive samples. (C). LDA analysis of group C. Green rectangle () (W): MAP-negative samples. Red rectangle () (T): MAP-positive samples.