Researchers have invented the world’s first multidimensional
antimicrobial susceptibility testing (AST) system. The new technology can
provide information about drug resistant pathogens present in patients,
enabling doctors to accurately determine the effectiveness and appropriate
dosage of antibiotics needed for effective treatment. It has been developed by
researchers from the Department of Chemistry at Hong Kong Baptist
The new fully-automated system is 10-20 times faster, more
accurate and can also be run at a much lower cost than the current AST methods
which are only available in professional medical laboratories. It is expected
that the invention will aid diagnosis by providing doctors with a precise
prescription which will significantly reduce the chance of antibiotic abuse or
misuse. The team is planning to commercialise the system so that more people
can benefit from the development.
In order to accurately test and analyse antibiotic
resistance, the team fabricated a hydrogel microfluidic chip which simulates
the drug diffusion process and the killing of pathogenic bacteria inside the
human body. The system is simple to operate and only requires a small amount of
the patient’s body fluid, such as blood or saliva. Once unwanted substances
have been removed, the sample fluid is placed on the chip, and is then treated
with different antibiotics. After about four hours, the system indicates the
effectiveness of the antibiotic treatment and whether it is needed. Due to the
chip’s multidimensional properties, multiple variables can be introduced
simultaneously, such as different antibiotics, nutrients and immunologic
substances. Automated microscopic observation of bacterial growth also enables
users to determine the most appropriate type, or the best combination, of
different types of antibiotics and the required dosage for treatment.
Research leader, Dr Ren Kangning, Assistant Professor
in the Department of Chemistry at HKBU says the method can analyse bacterial
morphology and quantity under the microscope. It takes only four hours to
obtain accurate AST data, making the treatment process faster and more accurate.
“Doctors will first evaluate the patient and then analyse a
small amount of their body fluid using the new system. Based on the results,
the antibiotic (or a combination thereof) with the lowest susceptibility, the
best efficacy, and the most appropriate dosage will be selected for the
patient. Hence, we can achieve better therapeutic performance and slow down the
process of antibiotic resistance,” Dr Ren says.
He explained that as the new system employs microfluidic
technology, compared with the existing AST methods, its accuracy is not only
higher, but it also requires much smaller samples and takes significantly less
time to carry out tests. In addition, the synergistic effects of multiple drugs
and the dynamic changes of different substances in the human body can also be
simulated. The ability to automate the test can reduce possible errors from
human manipulation and observation too.
The WHO estimates that around 300 million people will die
due to drug-resistant microbes in 2050, leading to serious economic losses
around the world. According to Dr Ren, this new method can slow down the
process of antimicrobial resistance and help to prevent the formation of
At the same time, he expects that the new system could be
used to collect information about antimicrobial resistance, which would
facilitate big data analysis and support the development of new antibiotics.
The research findings have been published in the
international academic journals Lab on a Chip, ChemPlusChem,
and Trends in Biotechnology.