摘要

       船舶压载作业可能会在全球海洋中转移有害的水生生物。本研究旨在揭示压载舱沉积物中抗生素抗性基因（ARGs）和人类细菌病原体（HBPs）的出现和丰度。采集9个样品，分别采用实时定量PCR和高通量测序技术进行分析。 10 个 ARG（aadA1、blaCTX-M、blaTEM、ermB、mefA、strB、sul1、sul2、tetM 和 tetQ）和 I 类整合子基因 (intI1) 在镇流器中非常普遍（105-109 基因拷贝/g）水箱沉积物。 sul1 是最丰富的 ARG，浓度为 108-109 拷贝/g，intI1 比压载舱沉积物中的 ARG 丰富得多。 intI1 和 ARG（blaCTX-M、sul1、sul2 和 tetM）之间的强正相关表明 ARG 通过水平基因转移的潜在传播。在压载舱沉积物中，虽然没有检测到国际海事组织提出的三种指示性病原微生物（霍乱弧菌、大肠杆菌和肠球菌），但 44 种细菌被鉴定为 HBP，占细菌总数的 0.13-21.46%。 Pseudomonas pseudoalcaligenes、Enterococcus hirae、Shigella Sonnei 和Bacillus anthracis 是压载舱沉积物中的主要病原体。沉积物中的锌和磷对 ARGs 有积极影响。网络分析结果表明 sul1 和 sul2 基因存在于几种细菌病原体中。压载舱沉积物可被视为 ARGs 迁移的载体。合理管理压载舱沉积物对于防止ARGs和细菌病原体的传播很重要。

       Ship ballasting operations may transfer harmful aquatic organisms across global ocean. This study aims to reveal the occurrences and abundances of antibiotic resistance genes (ARGs) and human bacterial pathogens (HBPs) in ballast tank sediments. Nine samples were collected and respectively analyzed by real-time quantitative PCR and high-throughput sequencing technologies. Ten ARGs (aadA1, blaCTX-M, blaTEM, ermB, mefA, strB, sul1, sul2, tetM, and tetQ) and the Class-I integron gene (intI1) were highly prevalent (105–109 gene copies/g) in ballast tank sediments. The sul1 was the most abundant ARG with the concentration of 108–109 copies/g and intI1 was much more abundant than the ARGs in ballast tank sediments. The strong positive correlations between intI1 and ARGs (blaCTX-M, sul1, sul2 and tetM) indicated the potential spread of ARGs via horizontal gene transfer. In ballast tank sediments, 44 bacterial species were identified as HBPs and accounted for 0.13–21.46% of the total bacterial population although the three indicator pathogenic microbes (Vibrio cholerae, Escherichia coli, and Enterococci) proposed by the International Maritime Organization were not detected. Pseudomonas pseudoalcaligenes, Enterococcus hirae, Shigella sonnei and Bacillus anthracis were the dominant pathogens in ballast tank sediments. Zn and P in sediments had positive effects on the ARGs. Network analysis results indicated that sul1 and sul2 genes existed in several bacterial pathogens. Ballast tank sediments could be regarded as a carrier for the migration of ARGs. It is important to manage ballast tank sediments reasonably in order to prevent the dissemination of ARGs and bacterial pathogens.

https://www.sciencedirect.com/science/article/abs/pii/S014765131830246X