The increasing spread of antibiotic resistance and the transmission of antibiotic resistance genes require the urgent development of rapid and cost-effective detection methods. The food chain plays a significant role in the dissemination of resistant bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). In this study, MRSA were isolated from milk and meat. A DNA MECA probe specific to the mecA gene was designed, evaluated in silico for specificity and experimentally through dot blot hybridization using DNA from S. aureus isolates confirmed by PCR. The probe was then integrated into an electrochemical biosensor based on Screen Printed gold Electrodes. In the absence of the target gene, the current signal stayed above baseline, whereas the presence of mecA gene resulted in a concentration-dependent decrease in signal, indicating effective hybridization within the range of 10 fg/μL - 1 ng/μL. Scanning electron microscopy analysis confirmed the presence of biological material exclusively on functionalized working electrode exposed to mecA-positive DNA. The system was further tested on S. aureus DNA extracted from 13 raw milk and meat matrices, demonstrating the biosensor's applicability for rapid (20-min), easy-to-perform, and low-cost detection of mecA gene. This work provides a promising basis for the development of on-site screening tools to monitor AR in the food production chain.
Detection of antibiotic resistance gene mecA in foodborne Staphylococcus aureus with electrochemical biosensor
Zanocco M.;Andreatta F.;Manzano M.
2026-01-01
Abstract
The increasing spread of antibiotic resistance and the transmission of antibiotic resistance genes require the urgent development of rapid and cost-effective detection methods. The food chain plays a significant role in the dissemination of resistant bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). In this study, MRSA were isolated from milk and meat. A DNA MECA probe specific to the mecA gene was designed, evaluated in silico for specificity and experimentally through dot blot hybridization using DNA from S. aureus isolates confirmed by PCR. The probe was then integrated into an electrochemical biosensor based on Screen Printed gold Electrodes. In the absence of the target gene, the current signal stayed above baseline, whereas the presence of mecA gene resulted in a concentration-dependent decrease in signal, indicating effective hybridization within the range of 10 fg/μL - 1 ng/μL. Scanning electron microscopy analysis confirmed the presence of biological material exclusively on functionalized working electrode exposed to mecA-positive DNA. The system was further tested on S. aureus DNA extracted from 13 raw milk and meat matrices, demonstrating the biosensor's applicability for rapid (20-min), easy-to-perform, and low-cost detection of mecA gene. This work provides a promising basis for the development of on-site screening tools to monitor AR in the food production chain.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
