Saving the Golden Time for Treating Super Bacteria
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Date : 2015-02-25
The fastest technology for antibiotic susceptibility test was developed by Korean research team.
This technology can check whether bacteria from patients have resistance to antibiotics 20 hours faster at maximum than current technologies, so it is expected to increase the survival rate of the patients with bacterial infections such as Super bacteria (bacteria which has resistance to most antibiotics and untreatable)
The joint research team from Department of Electrical Engineering and Computer Science of Seoul National University (Professor Sunghoon Kwon), Departments of Laboratory Medicine (Professor Sang Hoon Song and Eui Chong Kim) and Biomedical Engineering (Professor Jung Chan Lee and Hee Chan Kim) of Seoul National University Hospital, Professor Seungok Lee of Incheon St. Mary’s Hospital, and Doctor Yong-Gyun Jung of QuantaMatrix Inc. published this paper in the December issue of Science Translational Medicine, which is an internationally well-known journal.
Patients with bacterial infection should be tested for antibiotic susceptibility for antibiotics without resistance administered. In current methods for antibiotic susceptibility test (Broth microdilution method), the bacteria from the patients are mixed with antibiotics and incubated in solution and whether the bacteria is susceptible or resistant to antibiotics are judged based on the blurring degree of the solution.
The problem is the time required for obtaining the results of the tests. It usually takes 16~24 hours to get the results. For patients in emergent situations, doctors give antibiotics which they think are expected to control the infection based on their experience, and can prescribe appropriate antibiotics to which the bacteria the patients are non-resistant only after the test results are reported.
The new test method takes only 3~4.hours and the principle is as follows. Bacterial cells change their shapes into various forms depending on the types of antibiotics. Whether they are susceptible or resistant to the antibiotics can be judged by analyzing the morphological change one by one.
The research team developed a test kit for this. The test kit is a chemically-processed chip with the size of 12.8 cm × 8.6 cm, and has 96 furrows and each furrow is surrounded by microfluid channel. The bacterial cells collected from the patients and agarose fluid mixtures are administered together to this microfluid channel.
The agarose fluid in furrows becomes hardened like a gel which fixes bacterial cells. Then 20 different antibiotics at maximum are administered to each furrow, and the change of the shape of bacterial cells is analyzed through the automated microscopic image capture and analysis.
The research team tested 5 strains which are clinically the most important, S. aureus, vancomycin-resistant enterococci, K. pneumoniae, P. aeruginosa, and E. coli with those antibiotics tested in the hospital. According to the analysis through microscope, the bacterial cells were divided when resistant to the antibiotics while the shapes of the cells became longer or swollen when susceptible or non-resistant.
Based on these findings, the resistance of the bacterial cells to antibiotics could be confirmed by analyzing the change of their shapes.
For example, the bacterial cells collected from a patient infected by E. coli are tested with the antibiotics amikacin and aztreonam on the test kit developed by the research team. If the cell is divided in amikacin and becomes longer in aztreonam, the bacteria are resistant to amikacin and susceptible to aztreonam and the aztreonam can be prescribed to the patient.
The research team collected clinical strains from 189 patients with bacterial infections at Seoul National University Hospital and Incheon St. Mary\'s Hospital in Korea and tested with the new method and gold standard method for verification. The results were consistent with the gold standard method in 91.5% of the strains. It has met the standard of performance criteria for the new antibiotic susceptibility test recommended by U.S FDA.
Rapid prescription of appropriate antibiotic is a critical clinical decision in treating bacterial infection. The new method enables this, which is expected to increase the survival rate of patients and reduce the duration of hospitalization dramatically.
This technology is further expected to contribute to developing new antibiotics which is discouraged currently since it can be used to screening of candidate antibiotics which is a vital process in developing new antibiotics. Professor Eui Chong Kim said, "This is a technology that can save people."
This technology can check whether bacteria from patients have resistance to antibiotics 20 hours faster at maximum than current technologies, so it is expected to increase the survival rate of the patients with bacterial infections such as Super bacteria (bacteria which has resistance to most antibiotics and untreatable)
The joint research team from Department of Electrical Engineering and Computer Science of Seoul National University (Professor Sunghoon Kwon), Departments of Laboratory Medicine (Professor Sang Hoon Song and Eui Chong Kim) and Biomedical Engineering (Professor Jung Chan Lee and Hee Chan Kim) of Seoul National University Hospital, Professor Seungok Lee of Incheon St. Mary’s Hospital, and Doctor Yong-Gyun Jung of QuantaMatrix Inc. published this paper in the December issue of Science Translational Medicine, which is an internationally well-known journal.
Patients with bacterial infection should be tested for antibiotic susceptibility for antibiotics without resistance administered. In current methods for antibiotic susceptibility test (Broth microdilution method), the bacteria from the patients are mixed with antibiotics and incubated in solution and whether the bacteria is susceptible or resistant to antibiotics are judged based on the blurring degree of the solution.
The problem is the time required for obtaining the results of the tests. It usually takes 16~24 hours to get the results. For patients in emergent situations, doctors give antibiotics which they think are expected to control the infection based on their experience, and can prescribe appropriate antibiotics to which the bacteria the patients are non-resistant only after the test results are reported.
The new test method takes only 3~4.hours and the principle is as follows. Bacterial cells change their shapes into various forms depending on the types of antibiotics. Whether they are susceptible or resistant to the antibiotics can be judged by analyzing the morphological change one by one.
The research team developed a test kit for this. The test kit is a chemically-processed chip with the size of 12.8 cm × 8.6 cm, and has 96 furrows and each furrow is surrounded by microfluid channel. The bacterial cells collected from the patients and agarose fluid mixtures are administered together to this microfluid channel.
The agarose fluid in furrows becomes hardened like a gel which fixes bacterial cells. Then 20 different antibiotics at maximum are administered to each furrow, and the change of the shape of bacterial cells is analyzed through the automated microscopic image capture and analysis.
The research team tested 5 strains which are clinically the most important, S. aureus, vancomycin-resistant enterococci, K. pneumoniae, P. aeruginosa, and E. coli with those antibiotics tested in the hospital. According to the analysis through microscope, the bacterial cells were divided when resistant to the antibiotics while the shapes of the cells became longer or swollen when susceptible or non-resistant.
Based on these findings, the resistance of the bacterial cells to antibiotics could be confirmed by analyzing the change of their shapes.
For example, the bacterial cells collected from a patient infected by E. coli are tested with the antibiotics amikacin and aztreonam on the test kit developed by the research team. If the cell is divided in amikacin and becomes longer in aztreonam, the bacteria are resistant to amikacin and susceptible to aztreonam and the aztreonam can be prescribed to the patient.
The research team collected clinical strains from 189 patients with bacterial infections at Seoul National University Hospital and Incheon St. Mary\'s Hospital in Korea and tested with the new method and gold standard method for verification. The results were consistent with the gold standard method in 91.5% of the strains. It has met the standard of performance criteria for the new antibiotic susceptibility test recommended by U.S FDA.
Rapid prescription of appropriate antibiotic is a critical clinical decision in treating bacterial infection. The new method enables this, which is expected to increase the survival rate of patients and reduce the duration of hospitalization dramatically.
This technology is further expected to contribute to developing new antibiotics which is discouraged currently since it can be used to screening of candidate antibiotics which is a vital process in developing new antibiotics. Professor Eui Chong Kim said, "This is a technology that can save people."