A bacterial proliferation sensor based on naked-eye detection for rapid antimicrobial susceptibility testing from positive blood cultures.

The wide spread of antimicrobial resistance (AMR) is a crisis caused by the misuse of antibiotics. Despite the development of rapid antimicrobial susceptibility testing (AST) methods, there is an urgent need for an alternative rapid AST method that does not rely on testing equipment especially in resource-limited settings. In this work, a bacterial proliferation sensor based on naked-eye detection for rapid AST was developed. The sensor included the macroscopic bacterial culture chambers and bacterial growth detection microchannels for naked eye observation. After incubation at different antibiotic concentrations for 3–5 h, a one-step centrifugation effectively concentrated the suspended bacterial cells into visually observable microbars with length proportional to the number of cells, enabling to directly compare the bacterial accumulation under different drug concentrations. As a proof of concept, the sensor was able to determine the sensitivity of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) to drugs using the naked eye within 3–5 h. Furthermore, by combining with the thixotropic gel centrifugation method for bacteria separated from positive blood cultures (PBCs), we proposed a rapid and low-cost AST method for complex samples and evaluated the feasibility using clinical samples from cerebrospinal fluid-positive, blood-positive, ascites-positive and bile-positive culture bottles. The results were highly consistent with that from the clinical standard methods. The proposed sensor could achieve a rapid, low-cost, naked-eye detectable AST method for complex clinical samples, which would be applicable to the resource-limited areas. [Display omitted] • A rapid naked-eye detection bacterial proliferation sensor for antimicrobial susceptibility testing (AST) was developed. • Combined with thixotropic gel centrifugation, a rapid and low-cost AST method for complex samples was proposed. • The AST method was successfully applied to the diagnosis of clinical samples with reliable and fast results. [ABSTRACT FROM AUTHOR]