哈维弧菌对皱纹盘鲍不同组织内细菌群落结构的影响

Effect of Vibrio harveyi on the quantity and bacterial communities in different tissues of Haliotis discus hannai

利用Illumina测序技术研究了皱纹盘鲍(Haliotis discus hannai)消化道、鳃和足部的菌群结构,以及受哈维弧菌(Vibrio harveyi)胁迫后皱纹盘鲍消化道、鳃和足部肌肉菌群的动态变化。在皱纹盘鲍的消化道、鳃以及足部肌肉中检测到9个门的细菌,其中变形菌门(Proteobacteria)为优势菌门,在3种组织中的占比分别为30.1%~64.4%、37.45%~70.6%和71.1%~85.9%;拟杆菌门(Bacteroidetes,5.53%~46.09%)、梭杆菌门(Fusobacteria,4.43%~36.80%)及软壁菌门(Tenericutes,0.60%~28.77%)为次优势菌门;其余为放线菌门等5个菌门和一些未知类群。在属水平上,皱纹盘鲍消化道内的优势菌属为支原体属(Mycoplasma,15.85%~34.55%);鳃组织中的优势菌属为假单胞菌属(Pseudomonas,54.81%);足部肌肉中的优势菌属为假单胞菌属(Pseudomonas,44.83%~69.76%)和Curvibacter(21.24%),此外还有Pelomonas等菌属。引入病原哈维弧菌后,随着胁迫时间的延长,皱纹盘鲍消化道内弧菌的数量由7.2×10^(5)cfu·mL^(–1)升高至10.9×10^(5)cfu·mL^(–1);血液内的弧菌数量由2×10^(3)cfu·mL^(–1)升高至4.7×10^(3)cfu·mL^(–1);在受哈维弧菌胁迫48h后足部肌肉中弧菌的数量下降,其余时间点足部肌肉中弧菌的数量均增加。除了受哈维弧菌胁迫24h后消化道的Ace、Chao指数以及受胁迫96h后消化道的Ace指数高于对照组之外,其余时间点鲍消化道、鳃及足部肌肉的Ace、Chao指数均低于对照组。除受哈维弧菌胁迫24h后的鲍消化道、足部肌肉试验组和胁迫96h后的鳃组织试验组中的Shannon指数高于对照组外,其余时间点均低于对照组。引入哈维弧菌后,消化道内拟杆菌门及梭杆菌门的丰度均增加;鳃组织的变形菌门丰度下降,梭杆菌门的丰度增加;足部肌肉的变形菌门丰度增加,拟杆菌门的丰度则下降。在属的水平上,除了个别时间点外,消化道内的假单胞菌属、拟杆菌属(Bacteroides)、中度产丙酸菌属(Propionigenium)的丰度均增加,支原体属丰度则下降;鳃组织中的拟杆菌属、Kordia、中度产丙酸菌属的丰度均增加;足部肌肉中假单胞菌属的丰度也增加。本研究从微生态角度探究常见的病原哈维弧菌对宿主体内菌群组成结构的影响,为进一步研究宿主对病原哈维弧菌的响应机制及弧菌病的防治提供了新思路。

The quantity and the bacterial communities in the digestive tract,gill,and foot of Haliotis discus hannai after infection with Vibrio harveyi were studied using Illumina sequencing technology.Results showed that nine phyla of bacteria were detected in the digestive tract,gills,and foot muscles of H.discus hannai,with Proteobacteria being the dominant phylum,accounting for30.1%~64.4%,37.45%~70.6%,and 71.1%~85.9%of the tissues.Bacteroidetes(5.53%~46.09%),Fusobacteria(4.43%~36.80%)and Tenericutes(0.60%~28.77%)were the sub-dominant phyla,while five other phyla including Actinobacteria and some unknown taxa were also detected.At the genus level,the dominant genera in the digestive tract of H.discus hannai were Mycoplasma(15.85%~34.55%)and in the gill was Pseudomonas(54.81%).The dominant genera in the foot muscles were Pseudomonas(44.83%~69.76%)and Curvibacter(21.24%).There were also genera such as Pelomonas.After the introduction of the pathogenic V.harveyi,the quantity of vibrios in the digestive tract increased from 7.2×10^(5)cfu·mL^(–1)to 10.9×10^(5)cfu·mL^(–1)as the stress time increased;the quantity of vibrio in the blood increased from 2×10~3cfu·mL^(–1)to 4.7×10^(3)cfu·mL^(–1);the quantity of vibrios in the foot muscle decreased after 48 h of V.harveyi stress and increased in the foot muscle at all other time.The Ace and Chao indices of the abalone digestive tract,gills,and foot muscles were lower than those of the control group at all time,except for the Ace and Chao indices of the abalone digestive tract after 24 h of V.harveyi stress and the Ace index of the digestive tract after 96 h of stress.The Shannon index was higher than the control in the digestive tract and foot at 24 h and in gill at 96h after V.harveyi infection and lower than the control at the remaining time.The introduction of V.harveyi increased the abundance of the Bacteroidetes as well as Fusobacteria in the digestive tract;the abundance of Proteobacteria in the gill decreased while that of Fusobacteria increased;the abundance of Proteobacteria in the foot muscles increased and that of Bacteroidetes decreased.At the genus level,the abundance of Pseudomonas,Bacteroides,and Propionibacterium increased and the abundance of Mycoplasma decreased in the digestive tract,except for a few time;the abundance of Bacteroides,Kordia,and Propionibacterium increased in gill;and the abundance of Pseudomonas increased in foot muscles.This study investigated the effect of the common pathogen V.harveyi on the quantity and the bacterial communities of the host flora from a microecological perspective and provided a new idea for further research on the response mechanism of the host to the pathogen V.harveyi and the prevention and control of vibriosis.