摘要

       雨水径流通常具有非点源污染的特征。在本研究中，在强风暴事件前后，在两个小型浅水城市湖泊中调查了可培养的异养细菌的抗生素浓度和抗生素敏感性。强风暴事件后，两个小型城市湖泊（玄武湖和五龙潭）的地表水和/或表层沉积物中的几种抗生素、乳糖发酵细菌和可培养的异养细菌浓度增加。一般而言，风暴事件后细菌对九种抗生素表现出抗性的频率增加。从2个湖泊各水样中随机抽取的50个分离株的16S rRNA基因分析，气单胞菌属和芽孢杆菌属为2个湖泊水样中的优势属，变形杆菌属和赖氨酸杆菌属分别为玄武湖和乌龙图的第三丰富属。检测到 100 个分离株中存在 9 个抗生素抗性基因 (ARG)，并且这些分离株中的大多数含有至少两个具有不同功能的 ARG。革兰氏阴性菌株中ARGs的检出频率高于革兰氏阳性菌株。 100 个分离株中最普遍的整合子是 int(II) (n = 28)，其次是 int(I) (n = 17) 和 int(III) (n = 17)。我们的结果表明，强风暴事件可能有助于将 ARG 和抗生素耐药细菌从土地-下水道系统转移到城市湖泊。

       Stormwater runoff is generally characterized as non-point source pollution. In the present study, antibiotic concentration and antibiotic susceptibilities of cultivable heterotrophic bacteria were investigated in two small shallow urban lakes before and after strong storm event. Several antibiotics, lactose-fermenting bacteria and cultivable heterotrophic bacteria concentrations increased in surface water and/or surface sediment of two small urban lakes (Lake Xuanwu and Wulongtan) after strong storm event. In general, the frequencies of bacteria showing resistance to nine antibiotics increased after storm event. Based on the 16S rRNA genes of 50 randomly selected isolates from each water sample of two lakes, Aeromonas and Bacillus were dominant genera in samples from two lakes, while genera Proteus and Lysinibacillus were the third abundant genera in Lake Xuanwu and Wulongtu, respectively. Presences of nine antibiotic resistance genes (ARGs) in the 100 isolates were detected and most of these isolates harbored at least two ARGs with different functions. The detection frequency of ARGs in Gram-negative isolates was higher than that in Gram-positive isolates. The most prevalent integron in 100 isolates was int(II) (n = 28), followed by int(I) (n = 17) and int(III) (n = 17). Our results indicate that strong storm events potentially contribute to the transfer of ARGs and antibiotic-resistant bacteria from land-sewer system to the urban Lakes.

https://link.springer.com/article/10.1007/s11356-016-6237-9