Bacterial Community Associated with Healthy and Diseased Pacific White Shrimp (Litopenaeus vannamei) Larvae and Rearing Water across Different Growth Stages.

Yanfen Zheng,Mingchao Yu,Zhitao Li,Yanlu Qiao,Xiao-Hua Zhang,Long Wang,Jiwen Liu,Min Yu

doi:10.3389/fmicb.2017.01362

Abstract

Bacterial communities are called another “organ” for aquatic animals and their important influence on the health of host has drawn increasing attention. Thus, it is important to study the relationships between aquatic animals and bacterial communities. Here, bacterial communities associated with Litopenaeus vannamei larvae at different healthy statuses (diseased and healthy) and growth stages (i.e., zoea, mysis, and early postlarvae periods) were examined using 454-pyrosequencing of the 16S rRNA gene. Bacterial communities with significant difference were observed between healthy and diseased rearing water, and several bacterial groups, such as genera Nautella and Kordiimonas could also distinguish healthy and diseased shrimp. Rhodobacteraceae was widely distributed in rearing water at all growth stages but there were several stage-specific groups, indicating that bacterial members in rearing water assembled into distinct communities throughout the larval development. However, Gammaproteobacteria, mainly family Enterobacteriaceae, was the most abundant group (accounting for more than 85%) in shrimp larvae at all growth stages. This study compared bacterial communities associated with healthy and diseased L. vannamei larvae and rearing water, and identified several health- and growth stage-specific bacterial groups, which might be provided as indicators for monitoring the healthy status of shrimp larvae in hatchery.

Highlights

The intestine of shrimp and their ambient water are both complex ecosystems that harbor diverse bacterial communities, in which some microorganisms are probiotic while some are pathogenic
Xiong et al (2015) compared the bacterial communities between healthy and diseased shrimps, and found that Bacilli, Flavobacteriales, Acidimicrobiales, and Alteromonadales were more abundant in healthy shrimps, whereas Actinomycetales, Sphingobacteriales, and Vibrionales were dominant in diseased shrimps
The results showed that distinct bacterial communities assembled between healthy and diseased water, indicating that some specific bacterial groups might be applied as indicators for monitoring the health status of shrimp larvae in hatchery

Summary

Introduction

The intestine of shrimp and their ambient water are both complex ecosystems that harbor diverse bacterial communities, in which some microorganisms are probiotic while some are pathogenic. Bacterial Community Variation in Shrimp Larvae communities (Xiong et al, 2014; Zhang D. et al, 2014). These accumulated knowledge of the complex bacterial communities in aquaculture has refined our perception of which microbial groups could cause diseases. Growing efforts are made to predict the incidence of shrimp disease and find prevention methods from the bacterial perspective (Xiong et al, 2014, 2015; Zhang D. et al, 2014). Xiong et al (2015) compared the bacterial communities between healthy and diseased shrimps, and found that Bacilli, Flavobacteriales, Acidimicrobiales, and Alteromonadales were more abundant in healthy shrimps, whereas Actinomycetales, Sphingobacteriales, and Vibrionales were dominant in diseased shrimps. It was demonstrated that some bacterial groups (such as Flavobacteriales and Thiotrichales) could be considered as “health indicators” for predicting shrimp’s health status, and some other bacteria (such as Rhodobacterales and Planctomycetales) could be considered as “disease indicators” (Zhang D. et al, 2014)

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