Disinfectants, such as bleaching powder, are widely employed in marine aquaculture worldwide to control the bacterial pathogens and eliminate antibiotic resistance genes (ARGs). Nevertheless, the rapid recovery of prokaryotic community compositions (PCCs) after disinfection may significantly influence the overall efficacy of disinfection. Presently, little is known about the rapid recovery mechanisms of PCCs and its impact on the removal of ARGs in seawater. In this study, 16S rRNA gene sequencing and metagenomic analysis were used to address the above concerns through simulating the disinfection process in aquaculture. The results showed that recovery of PCCs began within 16 h. The underlying mechanisms of the rapid recovery of PCCs were the synergistic interactions between microbes and the residues of disinfection-resistant bacteria (DRB). Disinfection resistance genes (DRGs) related to efflux pump serve as the primary molecular foundation providing DRB to resist disinfection. Among the 78 annotated ARGs, only 10 ARGs exhibited a significant decrease (P < 0.05) after 72 h, implying the ineffective removal of ARGs by bleaching powder. Furthermore, bacterial co-resistance to disinfectants and antibiotics was observed. Genome analysis of two highly resistant DRB from Pseudomonadaceae revealed that both DRB carried 16 DRGs, aiding the recovery of PCCs and the spread of ARGs. These findings provide novel insights in the mechanisms of the rapid recovery of PCCs and bacterial co-resistance to disinfectants and antibiotics, which can be crucial for the management of pathogens and antibiotic resistance in seawater.

中文翻译：

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原核生物群落的快速恢复机制和海水消毒后抗生素耐药基因传播的宏基因组学见解


消毒剂，如漂白粉，广泛用于全球海水养殖，以控制细菌病原体和消除抗生素耐药基因 （ARG）。然而，消毒后原核生物群落组成 （PCC） 的快速恢复可能会显着影响消毒的整体效果。目前，人们对 PCC 的快速恢复机制及其对去除海水中 ARG 的影响知之甚少。在本研究中，采用 16S rRNA 基因测序和宏基因组分析通过模拟水产养殖中的消毒过程来解决上述问题。结果表明，PCCs 在 16 小时内开始恢复。PCCs 快速恢复的潜在机制是微生物与消毒耐药菌 （DRB） 残留物之间的协同相互作用。与外排泵相关的消毒抗性基因 （DRG） 是提供 DRB 抵抗消毒的主要分子基础。在 78 种注释的 ARGs 中，只有 10 种在 72 h 后表现出显著减少 （P < 0.05），表明漂白粉无法有效去除 ARGs。此外，观察到细菌对消毒剂和抗生素的共耐药性。对来自假单胞菌科的两个高抗性 DRB 的基因组分析显示，两个 DRB 都携带 16 个 DRG，有助于 PCCs 的恢复和 ARGs 的传播。这些发现为 PCC 的快速恢复和细菌对消毒剂和抗生素的共耐药性机制提供了新的见解，这对于管理海水中的病原体和抗生素耐药性至关重要。