U.S. Geological Survey, 5840 Enterprise Drive, Lansing, MI 48911, USA.
U.S. Geological Survey, 400 S. Clinton Street, Iowa City, Iowa 52240, USA.
Sci Total Environ. 2023 Dec 15;904:166753. doi: 10.1016/j.scitotenv.2023.166753. Epub 2023 Sep 4.
Antimicrobial resistance (AMR) is now recognized as a leading global threat to human health. Nevertheless, there currently is a limited understanding of the environment's role in the spread of AMR and antibiotic resistance genes (ARGs). In 2019, the U.S. Geological Survey conducted the first statewide assessment of antibiotic resistant bacteria (ARB) and ARGs in surface water and bed sediment collected from 34 stream locations across Iowa. Environmental samples were analyzed for a suite of 29 antibiotics and plated on selective media for 15 types of bacteria growth; DNA was extracted from culture growth and used in downstream polymerase chain reaction (PCR) assays for the detection of 24 ARGs. ARGs encoding resistance to antibiotics of clinical importance to human health and disease prevention were prioritized as their presence in stream systems has the potential for environmental significance. Total coliforms, Escherichia coli (E. coli), and staphylococci were nearly ubiquitous in both stream water and stream bed sediment samples, with enterococci present in 97 % of water samples, and Salmonella spp. growth present in 94 % and 67 % of water and bed sediment samples. Bacteria enumerations indicate that high bacteria loads are common in Iowa's streams, with 23 (68 %) streams exceeding state guidelines for primary contact for E. coli in recreational waters and 6 (18 %) streams exceeding the secondary contact advisory level. Although antibiotic-resistant E. coli growth was detected from 40 % of water samples, vancomycin-resistant enterococci (VRE) and penicillinase-resistant Staphylococcus aureus (MRSA) colony growth was detected from nearly all water samples. A total of 14 different ARGs were detected from viable bacteria cells from 30 Iowa streams (88 %, n = 34). Study results provide the first baseline understanding of the prevalence of ARB and ARGs throughout Iowa's waterways and health risk potential for humans, wildlife, and livestock using these waterways for drinking, irrigating, or recreating.
抗微生物药物耐药性（AMR）现在被认为是对人类健康的主要全球威胁。然而，目前对抗生素耐药性和抗生素耐药基因（ARGs）在环境中传播的作用的了解有限。2019 年，美国地质调查局首次对爱荷华州 34 个溪流地点采集的地表水和底泥中的抗药性细菌（ARB）和 ARGs 进行了全州评估。对环境样本进行了 29 种抗生素的分析，并在选择性培养基上对 15 种细菌生长进行了平板培养；从培养物生长中提取 DNA，并用于下游聚合酶链反应（PCR）检测 24 种 ARGs。优先考虑编码对人类健康和疾病预防具有临床重要性的抗生素耐药性的 ARGs，因为它们在溪流系统中的存在具有环境意义。总大肠菌群、大肠杆菌（E. coli）和葡萄球菌几乎普遍存在于溪流水和溪流底泥样本中，97%的水样中存在肠球菌，94%和 67%的水样和底泥样本中存在沙门氏菌生长。细菌计数表明，爱荷华州溪流中的细菌负荷很高，23（68%）条溪流中大肠杆菌的一级接触值超过了娱乐用水的州指导方针，6（18%）条溪流中二级接触值超过了建议水平。尽管从 40%的水样中检测到抗药性大肠杆菌生长，但从几乎所有水样中都检测到耐万古霉素肠球菌（VRE）和耐青霉素葡萄球菌（MRSA）的菌落生长。从爱荷华州的 30 条溪流中（88%，n=34）的存活细菌细胞中总共检测到 14 种不同的 ARGs。研究结果首次提供了对爱荷华州水道中 ARB 和 ARGs 的普遍性以及人类、野生动物和使用这些水道进行饮用水、灌溉或娱乐用水的牲畜的健康风险的初步了解。
