Background One of the most significant public health concerns in today's world is the persistent upsurge of infections caused by multidrug resistant bacteria. As a result, clinicians are being forced to intervene with either less effective backup drugs or ones with substantial side-effects. Colistin is a last resort antimicrobial agent for the treatment of infections caused by multi-drug resistant gram-negative bacteria. Methods Escherichia coli (n = 65) isolated from street food (n = 20), hand rinse (n = 15), surface water (n = 10), and healthy human stool (n = 20) were tested for colistin resistance gene mcr-1 and response to antimicrobial agents. Antimicrobial resistance genes and virulence genes were detected by employing polymerase chain reaction. DNA fingerprinting of the strains were determined by pulsed-field gel electrophoresis. Results Screening of E. coli allowed us to confirm colistin resistance marker gene mcr-1 in 13 strains (street food, n = 4; hand rinse, n = 2; surface water, n = 4; and stool, n = 3); and two of these E. coli strains carrying mcr-1 harbored bla TEM gene encoding extended spectrum beta lactamase. Antibiotic assay results revealed all 13 E. coli strains carrying mcr-1 to be multi-drug resistant (MDR), including to colistin. The minimum inhibitory concentration (MIC) for colistin ranged from 2 to 6 μg/ml. DNA sequencing confirmed homogeneity of the nucleotide sequence for mcr-1, but the E. coli strains were heterogenous, as confirmed by pulsed-field gel electrophoresis suggesting horizontal transmission of colistin resistance in Bangladesh. Conclusion Widespread dissemination of E. coli strains carrying mcr-1 encoding resistance to colistin in the present study is alarming as this is the last resort drug for the treatment of infections caused by MDR gram-negative bacteria resistant to almost all drugs used commonly.

中文翻译：

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孟加拉国的食品、水、洗手液和健康人类肠道中含有粘菌素耐药性大肠杆菌，其携带 mcr-1。


背景当今世界最重要的公共卫生问题之一是多重耐药细菌引起的感染持续激增。因此，临床医生被迫使用效果较差的备用药物或具有严重副作用的药物进行干预。粘菌素是治疗多重耐药革兰氏阴性菌引起的感染的最后手段抗菌剂。方法 对从街头食品 (n = 20)、洗手液 (n = 15)、地表水 (n = 10) 和健康人粪便 (n = 20) 中分离的大肠杆菌 (n = 65) 进行粘菌素抗性基因 mcr 检测-1和对抗菌药物的反应。采用聚合酶链式反应检测抗菌素耐药基因和毒力基因。通过脉冲场凝胶电泳测定菌株的DNA指纹。结果 通过大肠杆菌筛选，我们确认了 13 种菌株中的粘菌素抗性标记基因 mcr-1（街头食品，n = 4；洗手液，n = 2；地表水，n = 4；粪便，n = 3）；其中两个携带 mcr-1 的大肠杆菌菌株含有编码广谱 β 内酰胺酶的 bla TEM 基因。抗生素检测结果显示，所有 13 株携带 mcr-1 的大肠杆菌菌株均具有多重耐药性 (MDR)，包括粘菌素。粘菌素的最低抑菌浓度 (MIC) 范围为 2 至 6 μg/ml。 DNA 测序证实了 mcr-1 核苷酸序列的同质性，但大肠杆菌菌株是异质的，脉冲场凝胶电泳证实了这一点，表明孟加拉国粘菌素耐药性的水平传播。结论 E.广泛传播。 本研究中携带mcr-1编码对粘菌素耐药性的大肠杆菌菌株令人震惊，因为这是治疗由对几乎所有常用药物耐药的耐多药革兰氏阴性菌引起的感染的最后手段。