摘要

       在热带条件下的发展中国家，包括抗生素抗性基因 (ARG) 和粪便指示菌 (FIB) 在内的新兴生物污染物的发生仍然很少被调查。在这项研究中，总细菌负荷、FIB（大肠杆菌和肠球菌属（ENT））、假单胞菌属的丰度。和 ARG（blaTEM、blaCTX-M、blaSHV、blaNDM 和 aadA）使用定量 PCR 在从医院出口管道 (HOP) 和 Cauvery 河流域 (CRB)、蒂鲁吉拉伯利、泰米尔纳德邦回收的沉积物中提取的总 DNA 中进行量化，印度。大肠杆菌、肠球菌属的细菌标记基因的丰度分别高出 120、104 和 89 倍。与 CRB 相比，分别在 HOP 和假单胞菌属。在所有采样点，ARGs aadA 和 blaTEM 最常检测到的浓度高于其他 ARGs。在被医院和城市废水污染的 CRB 沉积物中发现了 ARG blaSHV 和 blaNDM。 ARGs 丰度与沉积物中的总细菌负荷和大肠杆菌密切相关（r ≥ 0.36，p < 0.05，n = 45），表明污染的共同来源和现存来源。接收废水的热带水生生态系统可以充当 ARG 的蓄水池，这些 ARG 可能会转移到这些地点的易感细菌病原体。

       The occurrence of emerging biological contaminants including antibiotic resistance genes (ARGs) and Faecal Indicator Bacteria (FIB) is still little investigated in developing countries under tropical conditions. In this study, the total bacterial load, the abundance of FIB (E. coli and Enterococcus spp. (ENT)), Pseudomonas spp. and ARGs (blaTEM, blaCTX-M, blaSHV, blaNDM and aadA) were quantified using quantitative PCR in the total DNA extracted from the sediments recovered from hospital outlet pipes (HOP) and the Cauvery River Basin (CRB), Tiruchirappalli, Tamil Nadu, India. The abundance of bacterial marker genes were 120, 104 and 89 fold higher for the E. coli, Enterococcus spp. and Pseudomonas spp., respectively at HOP when compared with CRB. The ARGs aadA and blaTEM were most frequently detected in higher concentration than other ARGs at all the sampling sites. The ARGs blaSHV and blaNDM were identified in CRB sediments contaminated by hospital and urban wastewaters. The ARGs abundance strongly correlated (r ≥ 0.36, p < 0.05, n = 45) with total bacterial load and E. coli in the sediments, indicating a common origin and extant source of contamination. Tropical aquatic ecosystems receiving wastewaters can act as reservoir of ARGs, which could potentially be transferred to susceptible bacterial pathogens at these sites.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0149211