Eiichi Tamiya

PCR-based Method for Rapid and Minimized Electrochemical Detection ofmecA Gene of Methicillin-resistant Staphylococcus aureus and MethicillinresistantStaphylococcus epidermidis

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important pathogens that cause nosocomial infections. However, microbiological culture techniques take a few days to yield results; therefore, a simple, cost-effective, and rapid detection system is required for screening for MRSA and related bacteria: Methicillinresistant Staphylococcus epidermidis (MRSE) carriers during the hospital admissions process. In this study, we described the simplified method using by one-time use and screen-printed carbon electrodes, relied upon current quantification of Hoechst dyes which bound with DNA amplified via polymerase chain reaction (PCR) targeted for MRSA mecA gene. Amount of DNA-bound Hoechst molecules were measured by the hand-held potentiostat within two minutes. We found that the peak of a Hoechst-mediated current depended upon the number of MRSA cells, and successfully distinguished between carriers and a non-carrier based on nasal swabs from the patients. This method required only 10 μL for application, and the results could be obtained within total 60 min from sample collection when a minimum of 1 × 103 MRSA cells was present. These results suggested that this minimized technique has the potential to become a useful system of active surveillance for MRSA/MRSE carriers.

In Situ Generation of Substrate via Bi-Potential Screen-Printed Electrode for Determination of Antioxidant Using Electrochemiluminescence

Excess generation of reactive oxygen species (ROS) could trigger a number of human diseases. We focused that antioxidants in beverages suppress the effect of ROS. Electrochemiluminescence (ECL) was determined by newly designed bi-potential screen printed electrodes and electron multiplying charge coupled device (EM-CCD) camera. Luminol based ECL was quenched due to the consumption of ROS by the antioxidants. Rapid and sensitive detection of antioxidants such as ascorbic acid and chlorogenic acid were demonstrated in beverage samples.

PCR-Based Method for Rapid and Minimized Electrochemical Detection of mec A Gene of Methicillin-Resistant Staphylococcus aureus and Methicillin-Resistant Staphylococcus epidermis

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important pathogens that cause nosocomial infections. However, microbiological culture techniques take a few days to yield results; therefore, a simple, cost-effective, and rapid detection system is required for screening for MRSA and related bacteria: Methicillin-resistant Staphylococcus epidermidis (MRSE) carriers during the hospital admissions process. In this study, we described the simplified method using by one-time use and screen-printed carbon electrodes, relied upon current quantification of Hoechst dyes which bound with DNA amplified via polymerase chain reaction (PCR) targeted for MRSA mecA gene. Amount of DNA-bound Hoechst molecules were measured by the hand-held potentiostat within two minutes. We found that the peak of a Hoechst-mediated current depended upon the number of MRSA isolates, and successfully distinguished between carriers and a non-carrier based on nasal swabs from the patients. This method required only 10 μL for application, and the results could be obtained within total 60 min from sample collection when a minimum of 1×103 MRSA isolates was present. These results suggested that this minimized technique has the potential to become a useful system of active surveillance for MRSA/MRSE carriers.