摘要

       船舶压载作业可能会将有害的水生生物转移到全球海洋。本研究旨在揭示压载水舱底泥中抗生素耐药基因（ARGs）和人类病原菌（HBPs）的发生和丰富程度。采集9份样品，分别采用实时定量PCR和高通量测序技术进行分析。压载舱底泥中10个ARGs（aadA1、blaCTX-M、blaTEM、ermB、mefA、strB、sul1、sul2、tetM和tetQ）和I类整合子基因（intI1）高度流行（105-109个基因拷贝/g）。sul1是最丰富的ARG，其浓度为108-109拷贝/g，intI1比压载舱沉积物中的ARG丰富得多。intI1与ARGs（blaCTX-M、sul1、sul2和tetM）呈强正相关，表明ARGs可能通过水平基因转移而扩散。在压载舱底泥中，虽然没有检测到国际海事组织提出的霍乱弧菌、大肠埃希菌和肠球菌三种指示病原微生物，但仍有44种细菌被鉴定为HBPs，占细菌总数的0.13-21.46%。压载舱底泥中的主要致病菌为假产碱假单胞菌、水蛭肠球菌、宋内志贺氏菌和炭疽杆菌。沉积物中的锌、磷对ARGs有正向影响。网络分析结果表明，sul1和sul2基因存在于多种病原菌中。压载舱沉积物可作为泥质运移的载体。合理管理压载舱底泥对防止泥质和细菌性病原体的传播具有重要意义。

        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://linkinghub.elsevier.com/retrieve/pii/S0147-6513(18)30246-X