Disease outbreak accompanies the dispersive structure of shrimp gut bacterial community with a simple core microbiota

Zhiyuan Yao,Linglin Qiuqian,Xiaolin Huang,Demin Zhang,Kunjie Yang,Kai Wang,Lei Huang

doi:10.1186/s13568-018-0644-x

Zhiyuan Yao, Linglin Qiuqian + Show 5 more

Open Access

https://doi.org/10.1186/s13568-018-0644-x

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Abstract

Increasing evidence has emerged supporting a tight link between gut bacterial community and shrimp health. However, the knowledge about the variation of gut bacterial community, especially with different disease onset time, remains elusive. Here, healthy and diseased shrimps were collected at 3 disease-outbreak times (day 70, 80 and 85) to investigate the variation of gut bacterial community and its underlying ecological process with 16S rRNA gene amplicon sequencing. The gut bacterial community of diseased shrimp was distinct from the healthy one and temporally less stable, characterized by decreased alpha-diversity and dispersive structure. And its dominant ecological process experienced a transition with disease onset time, although deterministic process mainly governed the healthy gut bacterial assembly. In addition, the core microbiota of healthy shrimp gut harbored more diverse bacterial taxa with more cooperative interactions, while the diseased core microbiota showed opposite pattern with significantly higher abundance of opportunistic pathogens as well. These findings indicate that shrimp heath is highly relevant to the homeostasis of its gut bacterial community. Preservation and restoration of the bacterial community equilibrium could represent an effective strategy for shrimp disease prevention.

Highlights

High frequency of disease outbreak is still one of the major bottle-necks of shrimp-culture industry development and often results in severe economic losses (Defoirdt et al 2011; Thitamadee et al 2016)
Alpha‐diversity, composition and structure of shrimp gut bacterial community The bacterial α-diversity indices were considerably lower in diseased shrimp (DI) than in the healthy control (HI) (Additional file 1: Figure S2)
This study provided further evidence that the alpha diversity of gut bacterial community significantly decreased in the diseased shrimp regardless of the outbreak time (Additional file 1: Figure S2), which is consistent with the previous studies suggesting that the disease outbreak likely accompany the decreased gut bacterial diversity (Cornejo-Granados et al 2017; Xiong et al 2015, 2017)

Summary

Introduction

High frequency of disease outbreak is still one of the major bottle-necks of shrimp-culture industry development and often results in severe economic losses (Defoirdt et al 2011; Thitamadee et al 2016). Healthy and diseased shrimps have distinct gut bacterial communities and the deviations are closely correlated with disease severity (Cornejo-Granados et al 2017; Xiong et al 2015; Zhang et al 2014). Xiong et al (2017) demonstrated that shrimp disease initiation and severity can be accurately diagnosed using gut microbiota immaturity and bacterial indicators. It has been revealed that the relative importance of deterministic processes decreases when shrimp disease occurs, which in turn make shrimp gut community more prone to invasion by alien strains (Xiong et al 2017; Zhu et al 2016).

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