Bacillus cereus is a pathogenic bacterium commonly found in food. After reserving for several days, the bacteria population reproduces and becomes high enough to cause human diarrhea, stomach, respiratory diseases, and, worst, death of patients led by hepatic failure.
Small restaurants, canteens at school and company, and family dining lack testing techniques and thus cannot detect Bacillus cereus effectively. The current situation motivates us to design a lab-free kit for detecting this harmful bacterium conveniently.
With this test kit designed for convenient, rapid use without lab environment, the small restaurants, canteens, and families can get rid of Bacillus cereus and ensure better food safety conditions.
Two testing methods are included in our kit design and they back each other. One method is measuring fluorescence intensity with ATP testing paper, which is time efficient (10 min) but not so accurate. The other one is detecting the existence of Bacillus cereus with the Holmes system, which is more time-consuming (1h) but also more accurate.
In both kinds of kit, the following items will be provided:
In ATP-testing approach specifically, the follwing items will be provided:
In HOLMES approach specifically, the following items will be provided:
Figure 1. The brief sketch of the design of the two kits
Figure 2. The source of inspiration of the design of sealed tube: both convenient and ensuring specific quantity
All the design described above rests in conception and is not carried out yet. The source of inspiration of APP on phone for detection of luminance is already achieved, and as for further improvement, we want to enhance the software and hardware to fully develop the kits and the APPs.
There are several safety concerns about the final product. First, because the proteins are extracted from bacteria, there might be leftover bacterial substance, which could cause harm to human. Then, the toxicity of LysPBC5, luciferin-luciferase system, and HOLMES system to human body is not clear yet, so the reagent might pose harm to the users when the reagents are misused, like intaking. Therefore, problems still exist in the safety of the test kit.
Because the design of the kit is not perfect. In the future, we'd like to further improve the design, making the whole apparatus more portable and user-friendsly, and try to solidify the design. Also, we aim to do further market research on how people will need this test kit and their additional requirements, which will be reflected on the improved design. At last, we will refine the production techniques using more advanced approaches so as to lower the cost and improve the quality. We believe that this efficinet and accurate testing kit can benefit the target users, small restaurants, canteens, and families, as mentioned before, a lot.
[1] Calabretta, M. M., Álvarez-Diduk, R., Michelini, E., Roda, A., & Merkoçi, A. (2020). Nano-lantern on paper for smartphone-based ATP detection. Biosensors and Bioelectronics, 150, 111902. https://doi.org/10.1016/j.bios.2019.111902
[2] Yang, J., Han, Y. H., Im, J., & Seo, S. W. (2021). Synthetic protein quality control to enhance full-length translation in bacteria. Nature Chemical Biology, 17(4), 421-427.
[3] Ruegg, T. L., Pereira, J. H., Chen, J. C., DeGiovanni, A., Novichkov, P., Mutalik, V. K., Tomaleri, G. P., Singer, S. W., Hillson, N. J., Simmons, B. A., Adams, P. D., & Thelen, M. P. (2018). Jungle Express is a versatile repressor system for tight transcriptional control. Nature Communications, 9(1). https://doi.org/10.1038/s41467-018-05857-3
