Recreational use of bathing waters is very popular in Germany and the European Union (EU). Therefore, the spread of antibiotic-resistant facultative-pathogenic bacteria (ARB) presents a possible public health issue. During the 2018 summer bathing season, a prevalence study involving 16 selected EU bathing waters in North Rhine-Westphalia was conducted. The aim was to identify the presence of ARB, antibiotic residues or resistance genes, and to develop a tool that assists advisers on prevention measures for individuals and the health authorities. The study included (i) hygienic-microbiological analyses according to the EU Bathing Water Directive, (ii) antibiotic residue measurements, (iii) cultural and molecular analyses to identify ARB and resistance genes and (iv) development of a risk assessment tool based on the burden of the bathing water and the vulnerability of bathing persons. All bathing waters were complied with the EU Bathing Water Directive. Three samples were found to contain very small amounts of ARB. Small quantities of antibiotic residues were detected in three bathing waters. Only one sample contained a resistance gene. In total, only 2 bathing waters were assumed to be systemically burdened with ARB and antibiotic residues or resistance genes. 4 bathing waters indicated single contamination events, 10 bathing waters were unburdened. In conclusion, bathing waters fulfilling criteria of the EU bathing water directive did not show high contaminations with ARB, antibiotic residues or resistance genes. However, we propose that people with risk factors should avoid swimming in burdened waters; people with immune deficiency should avoid swimming at all.

中文翻译：

---

评估德国西部欧盟沐浴水中抗药性细菌的患病率和抗生素浓度

娱乐性地使用沐浴水在德国和欧盟（EU）中非常流行。因此，抗生素耐药性兼性致病菌（ARB）的传播提出了可能的公共卫生问题。在2018年夏季沐浴季节期间，进行了一项流行性研究，涉及在北莱茵-威斯特法伦州选择的16种欧盟沐浴水。目的是确定ARB，抗生素残留或抗性基因的存在，并开发一种工具，以协助顾问为个人和卫生当局提供预防措施。这项研究包括（i）根据欧盟沐浴水指令进行的卫生微生物学分析，（ii）抗生素残留量的测量，（iii）文化和分子分析以识别ARB和抗性基因，以及（iv）根据沐浴水的负担和沐浴者的脆弱性开发风险评估工具。所有沐浴水均符合欧盟沐浴水指令。发现三个样品含有非常少量的ARB。在三个沐浴水中检测到少量抗生素残留。只有一个样品包含抗性基因。总体上，仅2个沐浴水被假定为全身充满ARB和抗生素残留或抗性基因。4个沐浴水显示单一污染事件，其中10个沐浴水没有负担。总之，符合欧盟沐浴水指令标准的沐浴水未显示ARB，抗生素残留或耐药基因的高污染。然而，我们建议有危险因素的人应避免在繁重的水中游泳；免疫缺陷的人应该完全避免游泳。