摘要

船舶压载作业可能会在全球海洋中传播有害水生生物。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）的发生和丰度。收集9个样品并分别通过实时定量PCR和高通量测序技术进行分析。十种ARG（aadA1，blaCTX-M，blaTEM，ermB，mefA，strB，sul1，sul2，tetM和tetQ）和I型整合子基因（intI1）高度流行（105-109个基因拷贝数/ g）坦克沉积物。 sul1是最丰富的ARG，浓度为108-109 copies / g，intI1比压载舱沉积物中的ARGs丰富得多。 intI1和ARGs（blaCTX-M，sul1，sul2和tetM）之间强烈的正相关表明ARGs通过水平基因转移的潜在传播。在压载舱沉积物中，虽然国际海事组织提出的三种指示性致病微生物（霍乱弧菌，大肠杆菌和肠球菌）未检测到，但在压载舱沉积物中，有44种细菌被鉴定为HBPs，占细菌总数的0.13-21.46％。产氢假单胞菌，海氏肠球菌，宋内志贺菌和炭疽芽孢杆菌是压载舱沉积物中的主要病原体。沉积物中的Zn和P对ARGs有积极的影响。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ARG迁移的载体。合理管理压载舱沉积物是非常重要的，以防止ARG和细菌病原体的传播。

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, andEnterococci) 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 sul2genes 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/pii/S014765131830246X