An enzyme-free homogenous electrochemical assay for sensitive detection of the plasmid-mediated colistin resistance gene mcr-1

作者：Li, Bo; Chai, Zhixin; Yan, Xiaohui; Liu, Chunchen; Bo Situ; Zhang, Ye; Pan, Weilun; Luo, Shihua; Liu, Jianhua; Zheng, Lei^*

来源：Analytical and Bioanalytical Chemistry, 2018, 410(20): 4885-4893.

DOI：10.1007/s00216-018-1130-7

• Colistin
• Electrochemical assay
• Hybridization chain reaction
• Isothermal amplification
• Mcr-1
• Resistance

Antibiotic resistance associated with the mcr-1 gene of Gram-negative bacteria, which confers resistance to drugs of last resort and has the potential to spread via plasmids, is one of the most pressing issues facing global health today. Point-of-care testing for the mcr-1 gene is needed to aid in the identification of colistin resistance in the field and to control its horizontal transmission. Here, we report the successful development of an enzyme-free homogenous electrochemical strategy for sensitive detection of the antibiotic resistance gene mcr-1 using the hybridization chain reaction and mcr-1-specific toehold probe. The long double-stranded DNA polymer produced using this strategy could be detected by assessing the diffusion of methylene blue towards the surface of a screen-printed gold electrode. Under optimized conditions, a linear relationship was observed between the variation of peak current and the natural logarithm of the mcr-1 gene concentration in the range of 1 nM to 1 mu M with a detection limit of 0.78 nM (S/N = 3). This enzyme-free, isothermal platform is a rapid, portable, disposable, and sensitive method for detection of plasmid-mediated colistin resistance.

• 出版日期2018-8
• 单位南方医科大学; 华南农业大学