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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
Detection of foodborne methicillin-resistant Staphylococcus aureus via fluorescence-encoded microsphere and
Luyu Wei1, Minjie Han1, Zhilong Wang2
1State Key Laboratory of Marine Food Processing and Safety Control, Dalian Polytechnic University, Dalian 116034, Liaoning, China; College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
Abstract:
Molecular diagnosis of foodborne methicillin-resistant Staphylococcus aureus (MRSA) is crucial for controlling its dissemination and ensuring food safety. However, existing genetic methods are limited by susceptibility to aerosol contamination and restricted to single-gene detection. Herein, a fluorescent biosensor employing fluorescence-encoded microspheres and Argonaute-mediated decoding is developed, enabling ultrasensitive, accurate, and duplex detection of MRSA genes. This assay utilizes a target-triggered polymerization/nicking reaction to cyclically produce specific guide DNA, guiding Argonaute protein to site-specifically cleave the molecular beacon on the microsphere, thereby decoding a fluorescent signal. Notably, the fluorescence-encoded microsphere, designed via on-tetrahedron rolling circle amplification, achieves high fluorescence loadings in a unit area. This biosensor demonstrates simultaneous detection of two unamplified MRSA genes, mecA and femA, at concentrations as low as 0.63 fM and 0.48 fM, respectively. Moreover, the method exhibited excellent recoveries in milk, egg, and pork samples ranging from 73% to 112%, highlighting its practicability in real scenarios.
Insights
A new fluorescent biosensor enables ultrasensitive, simultaneous detection of foodborne methicillin-resistant Staphylococcus aureus (MRSA) genes. This method improves accuracy and food safety by overcoming limitations of existing genetic detection techniques.
Area of Science:
- Food safety
- Molecular diagnostics
- Biosensor technology
Background:
- Foodborne methicillin-resistant Staphylococcus aureus (MRSA) poses a significant threat to public health and food safety.
- Current genetic detection methods for MRSA are often susceptible to contamination and limited to single-gene analysis.
Purpose of the Study:
- To develop an ultrasensitive, accurate, and duplex fluorescent biosensor for the molecular diagnosis of foodborne MRSA.
- To overcome the limitations of existing genetic detection methods, including aerosol contamination and single-gene detection.
Main Methods:
- Development of a fluorescent biosensor utilizing fluorescence-encoded microspheres and Argonaute-mediated decoding.
- Implementation of a target-triggered polymerization/nicking reaction for cyclic guide DNA production.
- Design of fluorescence-encoded microspheres via on-tetrahedron rolling circle amplification for high fluorescence loading.
Main Results:
- Simultaneous detection of two unamplified MRSA genes, mecA and femA, at ultra-low concentrations (0.63 fM and 0.48 fM, respectively).
- Demonstrated high sensitivity and accuracy with excellent recoveries (73%–112%) in real food samples (milk, egg, pork).
- The biosensor proved robust against aerosol contamination, a common issue in genetic assays.
Conclusions:
- The developed fluorescent biosensor offers a highly sensitive and accurate platform for the molecular detection of foodborne MRSA.
- This innovative assay significantly enhances food safety by providing a practical and reliable diagnostic tool.
- The Argonaute-mediated decoding and advanced microsphere design represent a breakthrough in biosensor technology for pathogen detection.
