Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil.
Área de Engenharia Costeira e Oceanográfica, COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-598, Brazil.
Lett Appl Microbiol. 2024 Sep 2;77(9). doi: 10.1093/lambio/ovae082.
Colistin resistance poses a major therapeutic challenge and resistant strains have now been reported worldwide. However, the occurrence of such bacteria in aquatic environments is considerably less understood. This study aimed to isolate and characterize colistin-resistant strains from water and plastic litter collected in an urban recreational estuary. Altogether, 64 strains with acquired colistin resistance were identified, mainly Acinetobacter spp. and Enterobacter spp. From these, 40.6% were positive for at least one mcr variant (1-9), 26.5% harbored, extended-spectrum beta-lactamases, 23.4% harbored, sulfonamide resistance genes, and 9.3% harbored, quinolone resistance genes. merA, encoding mercury resistance, was detected in 10.5% of these strains, most of which were also strong biofilm producers. The minimum inhibitory concentration toward colistin was determined for the mcr-positive strains and ranged from 2 to ≥512 µg ml-1. Our findings suggest that Gram-negative bacteria highly resistant to a last-resort antimicrobial can be found in recreational waters and plastic litter, thereby evidencing the urgency of the One Health approach to mitigate the antimicrobial resistance crisis.
粘菌素耐药性对治疗构成重大挑战，目前已在全球范围内报告存在耐药菌株。然而，人们对水生环境中此类细菌的了解甚少。本研究旨在从城市娱乐性河口采集的水和塑料垃圾中分离和鉴定具有获得性粘菌素耐药性的菌株。共鉴定出 64 株获得性粘菌素耐药菌株，主要为不动杆菌属和肠杆菌属。其中 40.6%至少对一种 mcr 变体（1-9）呈阳性，26.5%携带超广谱β-内酰胺酶，23.4%携带磺胺类耐药基因，9.3%携带喹诺酮类耐药基因。这些菌株中有 10.5%携带编码汞抗性的 merA 基因，其中大多数还是强生物膜生产者。对 mcr 阳性菌株进行了粘菌素最低抑菌浓度测定，范围为 2 至≥512 µg/ml。我们的研究结果表明，在娱乐性水域和塑料垃圾中可以发现对最后一线抗菌药物高度耐药的革兰氏阴性细菌，这表明需要采取“同一健康”方法来减轻抗菌药物耐药性危机。
