br Methodology br Antibiotics in lakes
Antibiotics in lakes
Antibiotic resistance genes in lakes
Perspectives of study on energy metabolism and ARGs in lakes
Conclusion This paper systematically reviewed the distribution of antibiotics and ARGs in global lakes. A total of 57 antibiotics reported at least once in the water and sediments of global lakes were assessed. The concentrations of these antibiotics in lake water were higher than those in lake sediment. As seen from our meta-analysis, sulfamethoxazole, sulfamerazine, sulfameter, tetracycline, oxytetracycline, erythromycin, and roxithromycin were found at high concentrations in both the lake water and sediment. There was also no significant difference in sulfamethoxazole and sulfamethazine concentrations in lake waters from China and the lake water from other countries worldwide; however, there was a significant difference in ofloxacin and norfloxacin concentrations between lake waters from China and from the rest of the world. The concentration of sulfamethoxazole and ofloxacin in bulk water from Taihu Lake significantly decreased between 2010 and 2015. ROX, ENR and CIP are “bioaccumulative” chemicals in aquatic organisms, whereas ETM had the highest ecological risk based on hazard quotient. There was also no significant difference in the concentration of sul genes in rivers and lakes. Chemical pollution, including antibiotics and heavy metals, influenced the distribution of ARGs in lakes through selection pressure. The bacterial community is the principle force in shaping the resistome, followed by mobile genetic elements.
Declaration of interest
This project was supported in part by National Natural Science Foundation of China [grant number 31400113, 31370479], Youth Innovation Promotion Association of Chinese Academy of Sciences [grant number 2015282], Wenzhou Science and Technology Major Project [grant number 2016N0031], Basic Public Welfare Research Projects in Zhejiang Province [grant number LGF18E090007], and State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control [grant number 2010DS700124-ZZ1802].
Introduction Travelers' diarrhea (TD) remains the most common health problem encountered by travelers to low-income regions [, , , ]. At present, its treatment is hotly debated. Traditionally, antibiotics used to be the mainstay of TD treatment , and even prophylaxis [6,7], yet recently the justification for this approach has been questioned due to the upsurge in antimicrobial resistance (AMR) [, , ]. AMR rates are highest in developing countries because of insufficient hygiene and lax/non-existent antibiotic policy; approximately 20–70% of travelers to these areas become colonized by multidrug-resistant (MDR) intestinal bacteria, especially extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) . More importantly, several studies have demonstrated antibiotic treatment of TD to predispose travelers to colonization by ESBL-PE [, , , , , ]. Very recently, it was shown that antibiotics, indeed, select ESBL-PE with the broadest spectrum of co-resistance . Several guidelines have now been revised to direct health practitioners toward less liberal writing of prescriptions , and antibiotics are no longer recommended for mild/moderate TD [19,20].
Material and methods
Discussion SBA has long been prescribed to a substantial proportion of travelers [1,23]. Recently, however, this practice has been challenged, since antibiotic use has been shown to predispose travelers to contracting intestinal MDR bacteria [, , , , , ]. At the same time, prescribing SBA has been justified by its assumed effect of decreasing the rate of seeking healthcare while abroad. This study exploring data on SBA among 316 Finnish travelers found that, as opposed to common belief, carrying SBA did not keep travelers from seeking healthcare. And, in fact, SBA increased their use of antibiotics.