Department of Zoology, University of Oxford, Oxford, United Kingdom
Department of Clinical Microbiology, MVZ synlab Leverkusen GmbH, Köln-Merheim, Germany.
Antimicrob Agents Chemother. 2018 Apr 26;62(5). doi: 10.1128/AAC.00209-18. Print 2018 May.
Antimicrobial resistance is a major health care problem, with the intensive use of heavy metals and biocides recently identified as a potential factor contributing to the aggravation of this situation. The present study investigated heavy metal susceptibility and genetic resistance determinants in isolated from clinical urine samples from Sweden, Germany, and Spain. A total of 186 isolates were tested for their sodium arsenite, silver nitrate, and copper(II) sulfate MICs. In addition, 88 of these isolates were subjected to whole-genome sequencing for characterization of their genetic resistance determinants and epidemiology. For sodium arsenite, the isolates could be categorized into a resistant and a nonresistant group based on MIC values. Isolates of the resistant group exhibited the chromosomal operon and belonged to non-B2 phylogenetic groups; in contrast, within the B2 phylogroup, no operon was found, and the isolates were susceptible to sodium arsenite. Two isolates also harbored the silver/copper resistance determinant , and they belonged to sequence types ST10 (phylogroup A) and ST295 (phylogroup C). The ST295 isolate had a silver nitrate MIC of ≥512 mg/liter and additionally produced extended-spectrum beta-lactamases. To our knowledge, this is the first study to describe the distribution of the arsenic resistance operon within phylogroups of strains isolated from patients with urinary tract infections. The arsenic resistance operon was present only in all non-B2 clades, which have previously been associated with the environment and commensalism in both humans and animals, while B2 clades lacked the operon.
抗微生物药物耐药性是一个主要的医疗保健问题，最近发现重金属和杀生剂的密集使用是导致这种情况恶化的一个潜在因素。本研究调查了从瑞典、德国和西班牙的临床尿液样本中分离出的 对重金属的敏感性和遗传耐药决定因素。对 186 株分离株进行了亚砷酸钠、硝酸银和硫酸铜 MIC 值的测试。此外，对其中 88 株进行了全基因组测序，以对其遗传耐药决定因素和流行病学进行表征。对于亚砷酸钠，根据 MIC 值可以将分离株分为耐药组和非耐药组。耐药组的分离株表现出染色体 操纵子，属于非 B2 系统发育群；相比之下，在 B2 系统发育群中，未发现 操纵子，分离株对亚砷酸钠敏感。有两个分离株还携带银/铜耐药决定因子 ，它们属于序列类型 ST10（系统发育群 A）和 ST295（系统发育群 C）。ST295 分离株的硝酸银 MIC 值≥512 毫克/升，并且还产生了超广谱β-内酰胺酶。据我们所知，这是首次描述砷耐药 操纵子在从尿路感染患者中分离出的 菌株的系统发育群中的分布情况。砷耐药 操纵子仅存在于所有非 B2 分支中，这些分支先前与环境和人与动物中的共生有关，而 B2 分支则缺乏 操纵子。
