摘要

       当今世界面临的主要公共卫生问题之一是环境中抗生素抗性细菌 (ARB) 的发生和传播。 ARB 的主要蓄水池是水生生态系统。使用基于培养的方法和定性分子技术来筛选和确定美国路易斯安那州东南部湿地沼泽三种不同盐度梯度中抗生素抗性基因 (ARG) 和 ARB 的存在。感兴趣的细菌包括阴沟肠杆菌/产气菌、肠球菌属。和大肠杆菌。感兴趣的抗生素抗性基因包括 ermB、sul1、tetA、tetX、tetW 和 mecA，它们负责对红霉素、磺胺、四环素和甲氧西林抗生素产生抗性。水的盐度范围从 0 到 12 ppm (ppt)。在六个月的时间内每月采集一次样本，并分析水样中 ARB 和 ARG 的存在以及碳、氮和磷水平。结果表明，在湿地中存在 ARB 和 ARGs 时，盐度没有显着差异。在路易斯安那州东南部沼泽的所有三个盐度水平（0、6 和 12 ppt）中都发现了大量 ARB。 ARG 在盐度为 6 ppt 的位点 2 中更为普遍，其次是盐度为 12 ppt 的位点 1 和盐度为 0 ppt 的位点 3。细菌负荷和污染负荷随月份和三种盐度之间的变化而变化。这项研究表明，湿地栖息地中 ARB 和 ARG 的存在令人担忧，因为即使在高盐度栖息地，人类活动也存在 ARG 传播到本地细菌、鱼类和野生动物的潜在威胁。

       One of the major public health problems facing the world today is the occurrence and spread of antibiotic resistant bacteria (ARB) in the environment. The main reservoir for ARB is the aquatic ecosystems. Culture based methods and qualitative molecular techniques were used to screen and determine the presence of antibiotic resistance genes (ARG) and ARB in three different salinity gradients of wetland marsh in the southeast Louisiana of USA. The bacteria of interest include Enterobacter cloacae/aerogenes, Enterococci spp. and Escherichia coli. The antibiotic resistance genes of interest include ermB, sul1, tetA, tetX, tetW, and mecA that are responsible for resistance to erythromycin, sulfonamide, tetracycline, and methicillin antibiotics. The water salinity ranged from 0 to 12 parts per thousand (ppt). Monthly samples were taken for a six-month period and analyzed for the presence of ARB and ARGs along with carbon, nitrogen, and phosphorous levels in the water samples. The results indicated salinity did not have significant difference in the presence of ARB and ARGs in the wetlands. Significant numbers of ARB were found in all three salinity levels (0, 6, and 12 ppt) in the marshes of Southeast Louisiana. ARGs were more prevalent in site 2 with the salinity of 6 ppt followed by site 1 with the salinity of 12 ppt and site 3 with 0 ppt salinity. Bacterial load and the pollution load varied from month to month and among the three salinities. This study indicates the presence of ARB and ARGs in the wetland habitat is a cause for concern as the potential threat of the spread of ARGs into native bacteria and into fish and wildlife exists due to human activities even under high salinity habitat.

https://www.sciencedirect.com/science/article/abs/pii/S0964830516300427