Abstract:
Acute ammonia exposure has detrimental effects on shrimp, but the underlying mechanisms remain to be fully explored. In the present study, we investigated the impact of acute ammonia exposure on the gut microbiota of the white shrimp Litopenaeus vannamei and its association with shrimp mortality. Exposure to a lethal concentration of ammonia for 48 h resulted in increased mortality in L. vannamei, with severe damage to the hepatopancreas. Ammonia exposure led to a significant decrease in gut microbial diversity, along with the loss of beneficial bacterial taxa and the proliferation of pathogenic Vibrio strains. A phenotypic analysis revealed a transition from the dominance of aerobic to facultative anaerobic strains due to ammonia exposure. A functional analysis revealed that ammonia exposure led to an enrichment of genes related to biofilm formation, host colonization, and virulence pathogenicity. A species-level analysis and experiments suggest the key role of a Vibrio harveyi strain in causing shrimp disease and specificity under distinct environments. These findings provide new information on the mechanism of shrimp disease under environmental changes.
摘要:
急性氨暴露对虾有有害影响,但是潜在的机制仍有待充分探索。在本研究中,我们调查了急性氨暴露对凡纳滨对虾肠道菌群的影响及其与虾死亡率的关系。暴露于致死浓度的氨48小时导致南美白对虾的死亡率增加,肝胰腺严重受损.氨暴露导致肠道微生物多样性显著下降,伴随着有益细菌分类群的丧失和致病性弧菌菌株的增殖。表型分析显示,由于氨暴露,需氧菌株的优势转变为兼性厌氧菌株。功能分析显示,氨暴露导致与生物膜形成相关的基因富集,宿主定殖,和毒力致病性。物种水平的分析和实验表明,哈维氏弧菌菌株在不同环境下引起对虾疾病和特异性的关键作用。这些发现为环境变化下对虾病的机理提供了新的信息。