National University of Singapore, Department of Civil and Environmental Engineering, Engineering Drive 1, T-lab Building, TL08-03, 117576, Singapore.
Duke University, Department of Civil and Environmental Engineering, 100 Hudson Hall, Durham, NC 27708-0287, United States.
Sci Total Environ. 2018 Jan 1;610-611:651-656. doi: 10.1016/j.scitotenv.2017.08.099. Epub 2017 Aug 17.
Ballast water discharges are potential sources for the spread of invasive and pathogenic aquatic organisms. Ballast waters from six ships docked in the Port of Singapore were tested to determine if indictor organisms fell within proposed standards for ballast water discharge according to regulation D-2 of the Ballast Water Management Convention (BWMC) guidelines. Vibrio species were cultured on media supplemented with beta-lactam antibiotics to determine the presence of antibiotic resistant Vibrio species in the ballast waters of these vessels. Indicator organisms were quantified using culture media Colilert-18 and Enterolert in ballast waters of six ships docked in a tropical harbor, with uptake from different geographical locations. Of the six ships, one had ballast water originating from the Persian Gulf, another from the East China Sea, and four from the South China Sea. Two of the six ships which carried ballast waters from the East China Sea and the South China Sea did not meet the D-2 stipulated requirements of the Ballast Water Management Convention for indicator organisms with Enterococci values more than three times higher than the acceptable limit of <100CFU/100mL. Using the most-probable-number-PCR (MPN-PCR) method for Vibrio species detection, non-toxigenic species of V. cholerae (2 MPN/100mL), Vibrio vulnificus (>110 MPN/100mL), and Vibrio parahaemolyticus (2 to >110 MPN/100mL) were detected in at least one of six ballast water samples. Using thiosulfate-citrate-bile salts-sucrose agar (TCBS) supplemented with beta-lactam antibiotics (meropenem, ceftazidime), 11 different Vibrio species, exhibiting resistance to beta-lactam antibiotics were isolated; with Vibrio campbellii (44%) and Vibrio alginolyticus (15%) the most detected antibiotic resistant Vibrio species. A practical approach of prioritized screening of high-risk vessels should be conducted to ensure that the water quality meets D-2 standards prior to discharge.
压载水排放是入侵性和致病性水生生物扩散的潜在来源。对停靠在新加坡港的六艘船舶的压载水进行了测试，以确定根据《压载水管理公约》（BWMC）准则 D-2 的规定，指示生物是否符合压载水排放的标准。在这些船只的压载水中，用添加了β-内酰胺抗生素的培养基培养弧菌属，以确定是否存在抗生素抗性弧菌属。在停靠在热带港口的六艘船舶的压载水中，使用 Colilert-18 和 Enterolert 培养基定量指示生物，同时从不同地理位置取样。在这六艘船中，一艘来自波斯湾，一艘来自东海，四艘来自南海。来自东海和南海的两艘船的压载水携带的指示生物不符合《压载水管理公约》D-2 规定的要求，其肠球菌值比可接受限值 <100CFU/100mL 高出三倍以上。使用最可能数-PCR（MPN-PCR）方法检测弧菌属，在至少一个压载水样本中检测到非产毒霍乱弧菌（2 MPN/100mL）、创伤弧菌（>110 MPN/100mL）和副溶血性弧菌（2 至>110 MPN/100mL）。在添加β-内酰胺抗生素（美罗培南、头孢他啶）的硫代硫酸盐-柠檬酸盐-胆汁盐-蔗糖琼脂（TCBS）上，分离出 11 种不同的对β-内酰胺抗生素具有抗性的弧菌属，其中以坎贝尔氏弧菌（44%）和 alginolyticus 弧菌（15%）最为常见。应采用风险优先筛选的实用方法对高风险船舶进行筛选，以确保在排放之前水质符合 D-2 标准。
