Departamento de Bacteriología y Virología, Instituto de Higiene, Facultad de Medicina Universidad de la República, Montevideo, Uruguay.
Unidad de Enfermedades Infecciosas, Hospital Maciel, ASSE, Montevideo, Uruguay.
J Glob Antimicrob Resist. 2020 Mar;20:187-190. doi: 10.1016/j.jgar.2019.07.016. Epub 2019 Jul 20.
This report described the first Escherichia coli (E. coli) isolates harbouring mcr-1 in Uruguay.
Three E. coli isolates were obtained from blood, urine and rectal swabs from different patients in two hospitals. Extended-spectrum β-lactamases (ESBL), plasmid-encoded (pAmpC) β-lactamases, plasmid-mediated quinolone resistance (PMQR) genes, class 1 integrons, and mcr-1, mcr-2 and mcr-3 were sought and characterised in three E. coli isolates. Transfer of resistance determinants was assessed by conjugation. Clonality was analysed by multilocus sequence typing.
All isolates were categorised as being colistin-resistant and the mcr-1 gene was detected. Two isolates were also resistant to oxyimino cephalosporins: one on account of bla and the other due to bla, the latter also harbouring transferable quinolone-resistance genes (aac(6')Ib-cr and qnrB). All mcr-1 genes were transferred by conjugation to recipient strains. The mcr-1-bearing isolates belonged to sequence types ST10, ST93 and ST5442.
ST10 is considered as a high-risk clone worldwide. This type of mcr-1-harbouring clone is a major concern for human and animal health and must be under close surveillance. This study detected the presence of mcr-1 for the first time in Uruguay, albeit in an allodemic manner, associated with different antibiotic-resistance genes and from diverse clinical contexts. Considering that colistin is often the last therapeutic option available for multidrug-resistant Gram-negative bacilli infections, it is important to maximise precautions to avoid dissemination of isolates carrying mcr-1.
本报告描述了乌拉圭首次分离到携带 mcr-1 的大肠杆菌（E. coli）。
从两家医院不同患者的血液、尿液和直肠拭子中获得了 3 株大肠杆菌。在 3 株大肠杆菌中寻找和鉴定了超广谱β-内酰胺酶（ESBL）、质粒编码（pAmpC）β-内酰胺酶、质粒介导的喹诺酮耐药（PMQR）基因、1 类整合子和 mcr-1、mcr-2 和 mcr-3。通过接合评估了耐药决定因素的转移。通过多位点序列分型分析了克隆性。
所有分离株均被归类为多粘菌素耐药，并且检测到 mcr-1 基因。有两株分离株也对氧肟头孢菌素耐药：一株是由于 bla，另一株是由于 bla，后者还携带可转移的喹诺酮耐药基因（aac(6')Ib-cr 和 qnrB）。所有 mcr-1 基因均通过接合转移到受体株。携带 mcr-1 的分离株属于 ST10、ST93 和 ST5442 序列型。
ST10 被认为是全球高风险克隆。这种类型的 mcr-1 携带克隆对人类和动物健康构成重大威胁，必须密切监测。本研究首次在乌拉圭检测到 mcr-1 的存在，尽管是等位基因方式，与不同的抗生素耐药基因和不同的临床背景有关。考虑到多粘菌素通常是治疗多重耐药革兰氏阴性菌感染的最后一种治疗选择，因此重要的是要最大限度地采取预防措施，以避免携带 mcr-1 的分离株的传播。
