| In recent years, issues of food safety are frequently, foodborne pathogens is one of the main reason which causes serious harm to human and animal health, causing great concern at home and abroad. Effective rapid detection of foodborne pathogens is an important part to monitor, prevent and diagnosis foodborne pathogens. Research and development of better modern rapid detection technology has become a hot spot. Personal glucose meters (PGM) have been widely used in the medical field because it have the advantages of portable, fast, economical, easy to operate, accurate, intuitive and so on. It is a commonly method used to rapid diagnosis and monitoring diabetes in the hospitals and at home. While, in the fields of bacterial detection, even rapid detection, the operations are usually complicated and time-consuming. Standard methods and rapid detection method are the two popular methods for detecting bacteria quantitative and qualitative currently. There are a lot of rapid detection technologies which have a variety advantages, but also need to be improved. PCR which has many advantages and has been widely applied has a large room for improvement in the cost and security. Other detection methods are also satisfactory enough in the fast, convenient, cheap, safe, accurate and other aspects. There has no report on qualitative/quantitative detection of foodborne pathogens by personal blood glucose meter and its supporting electrode.This study attempted to use PGM and its supporting electrode to count the E. coli in culture firstly, and then determined the total bacteria number. And on the basis of quantitative detection, qualitative detection was studied to rapid detection of Vibrio and Bacillus stearothermophilus (B. St). The purpose of this study is to build a novel method to qualitative/quantitative detect foodborne pathogens rapidly by PGM and its supporting electrodes. Under the premise of accurate and sensitive, this method has a great advantage in the aspects of fast, easy to operate and economic, which has a good research value and application prospect.1. Preliminary research on rapid count of bacteria using PGM.The purpose of this chapter is to apply PGM and its supporting electrode to measure the changes of glucose concentration in the culture, to build a novel electrochemical detection method for rapid count of foodborne pathogens. This chapter selected Escherichia coli (E. coli) as a model strain, nutrient broth as a base medium. Appropriate concentration range of glucose in medium and best detectable concentration, appropriate detection time, pH and temperature were selected. The relationship between glucose consumption and E. coli concentration was determined according to the national standard method. The results showed that PGM and its supporting enzyme electrodes are applied to this system, and glucose concentration in nutrient broth can be measured accurately by PGM at the range of1.1mmol·L-1to33.3mmol·L-1. Under the optimized conditions, the glucose consumption (AC) presents a corresponding linear increase with increase of the concentration of E. coli in a range from103to109CFU/mL, with a low detection limit of102 CFU/mL. The linear regression equation was△C(mmol/L)=0.657lg [C/CFU·ml-1]-1.271with a correlation coefficient of0.993. This method does not require pre-treatment of the sample, and the detection can be completed in4h. This study showed that count E. coli by PGM is feasible, and the biggest advantages are fast, convenient, economical and safe. So it is worthy of further study.2. Research on quantitative detection of total bacteria number using PGMThe purpose of this chapter is to use PGM to detect the total bacteria number in food samples to obtain a better detection method of the total bacteria number. Parameters such as initial concentration of glucose in the medium, detection time, incubation temperature and pH are selected and optimized to develop a novel rapid biosensor detection of the total bacteria number in food samples, and detection results can be obtained within4h. Glucose consumption (AC) and the logarithmic value of bacterial concentration showed a good linear relationship in a certain range with a detection limit of101CFU/mL-102CFU/mL (S/N=3). This method showed a good accuracy according to the national standard method. This study showed that this method can detect the total bacteria number of variety of food samples rapid and accurate, and has good development potential.3. Research on rapid detection of Vibrio using PGMVibrio is the most important bacteria of aquatic safety, detection of Vibrio can be served as an important indicator of aquatic products pollution levels and the safety of aquatic products. Vibrio. parahaemolyticus (V. parahaemolyticus, V. P) was used as a model species in this study. PGM and its supporting electrode were combined with glucose-TCBS to develop a novel qualitative and quantitative analytical method for rapid detect Vibrio. Measurement conditions were selected and optimized. The result showed that when V. P concentration changed between103～109CFU/mL, the logarithmic value of V. P concentration and AC was in a good linear relationship with a detection limit of102CFU/mL (S/N=3). Correspondingly, the linear regression equation was AC (mM)=0.526lg [C/CFU·ml-1]+2.188with a correlation coefficient of0.994. This study showed that the biggest advantage of this method is rapid, which can be completed within6h, only1/3to1/4of conventional culture methods. In addition, it is a simple, economical, specific and accurate analytical method which has a good promising for rapid detection Vibrio in aquatic products.4. Research on rapid detection of B. stearothermophilus using PGMBacillus stearothermophilus (B. stearothermophilus, B. St) can lead to rancidity deterioration of variety canned, such as vegetables and meat. It is an important indicator to evaluate the canned food security. To develop a novel method for rapid detection B. St, this study combined PGM and bromocresol purple glucose peptone, monitored and comparative analysis the glucose consumption in cultures and selected and optimized the detection conditions. The results showed that under optimal detection conditions, entire procedures can be completed within6h, when B. St concentration changed between10～10CFU/mL, the logarithmic value of B. St concentration and AC was in a good linear relationship with a detection limit of101CFU/mL (S/N=3). Correspondingly, the linear regression equation was AC (mmol/L)=0.502lg [C/CFU·ml-1]+1.698with a correlation coefficient of0.994. This study showed PGM and its supporting electrode can qualitative and quantitative detect B. St by monitoring the glucose consumption in bromocresol purple glucose peptone. The method has a significant advantage in the rapid. It also has a good sensitivity, specificity and accuracy, and convenient and economical. This method can be promoted to rapid detect B. St in canned food as a novel technology, and has a good prospect for innovation and application. |
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