A research team led by scientists at Hong Kong Baptist University (HKBU) has developed a novel cell sensor with a barcode-like micro-channel structure, designed to enable rapid and low-cost screening of drug-resistant bacteria. The tech could potentially be used on a large-scale in resource-limited situations such as frequent safety screenings of water, food and public facilities, the researchers say, as well as urgent surveys of massive samples during an infectious disease outbreak, particularly in developing countries.
Antibiotics are often used to treat bacterial infections, but the overuse and misuse of antibiotics have created the problem of drug resistance. Antimicrobial susceptibility testing (AST) is used to determine which antibiotics can effectively inhibit the growth of a certain type of bacteria effectively. However, conventional AST methods require 16 to 24 hours for results, while modern rapid ASTs are expensive and require laboratory equipment. The researchers aimed to find a rapid and cost-effective strategy to screen bacterial samples onsite, with advanced laboratory testing arranged only for those suspected of containing drug-resistant bacteria.
The team, led by Dr Ren Kangning, Associate Professor of the Department of Chemistry at HKBU, designed an automatic, microscope-free AST system. It comprises two main parts: a cell culture zone and a “barcode” cell sensor. The cell culture zone consists of a set of micro-channels filled with fluids that contain cell culture media as well as different concentrations of the antibiotic. The “barcode” cell sensor contains an array of “adaptive linear filters” arranged in parallel that resembles a “barcode” structure. Users can finish the onsite screening within three hours by scanning the “barcode” with a mobile app developed by the researchers, and it will indicate whether any drug-resistant pathogenic bacteria is present in the sample.
The research team tested E. coli and S. aureus with the “barcode” cell sensor and the results were consistent with those of the conventional AST. The test can be completed in three hours, which is much faster than the conventional AST. Microfluidic approaches developed by other researchers can also attain comparable speed, but they rely on expensive instruments for analysis in general.
“Our ‘barcode’ testing system is a promising new tool in the fight against antimicrobial resistance. We hope that it will benefit the routine screening of drug-resistant bacteria in the food industry, public areas and healthcare facilities as it does not require advanced clinical facilities or professional testing skills,” said Dr Ren.
Apart from researchers from HKBU’s Department of Chemistry, the research team of the “barcode” cell sensor also included scientists from the Department of Computer Science at HKBU and the School of Medicine at Stanford University.
