Overview
During our project progress, we achieved the preliminary investigation and background survey, and set
our project goals as foodborne pathogens detection using cell free system. But in the actual
implementation, we encountered the problems about paper-based production, optimization of
experimental design, and selection of the proper end users, etc. So, we seek the help from the
experts and quick detection company to improve our product. According to their suggestions, we
gradually determined the objectives and target users, inspired us to improve the hardware design and
developed a user-friendly APP to readout our results, etc.
Public Survey
According to our questionnaire survey, the number of people who eat canned food is still large and
the types of canned food they eat are wide. Although people have a certain awareness of food safety
testing for canned food, most of them do not know the specific food-borne pathogens that cause food
safety problems, so they cannot do effective protection. The phage-binding protein method used in
our project to detect foodborne pathogens is considered novel but the mechanism is not understood.
Therefore, our subsequent work is to illustrate and publicize the principle of our project.
In order to know how often people eat canned food and what they know about food-borne pathogens in
canned food, so we created a questionnaire. A total of 715 people of all genders, ages and
educational backgrounds responded to the open questionnaire.
Almost 90% of respondents had the consciousness of checking the safety of food after purchasing. Most
of the methods to detect food safety are to check whether the air leaks or bags expand, smell and
check whether stratification. It shows that most of the questionnaire fillers have food safety
awareness.
Participants in the questionnaire had purchased cans. Examples include canned meat and poultry,
canned aquatic animals, canned fruits, canned vegetables, canned dried fruits and nuts, and canned
cereals and beans. Among them, the number of people who buy canned meat, canned fruit and dried
fruits and nuts is higher. Among 715 people, 45.73% thought that canned food was very safe after
sterilization, 50.35% thought that canned food was sterilized but still had fungus residue, and the
safety was not good, only 3.92% thought that canned food had a lot of fungus residue, and the safety
was not good. This shows that people use canned food more frequently, and 50.35% of people have
doubts about the safety of canned food.
About whether they had heard of foodborne pathogens, 65.59% had heard a little about them, 24.06% had
not heard of them at all, and only 10.35% knew a lot about them. Pathogenic Escherichia coli,
Salmonella, Staphylococcus aureus and Vibrio cholerae are well known among bacteria in Shigella,
pathogenic Escherichia coli, Vibrio cholerae, Salmonella, Staphylococcus aureus, Clostridium
botulinum, and Listeria. According to CDC estimates, an average of 48 million people in the United
States are sickened by FBD each year, 12,800 are hospitalized, and 3,000 die. Foodborne diseases are
not well known and effectively prevented.
96.5% of people believed that foodborne pathogens could contaminate canned food and cause diarrhea,
severe dehydration, toxemia and enteritis.
More than half of the participants had heard a little bit about phages. More than half of the
participants had heard a little bit about phages. Our plan to use phage-specific binding proteins to
detect foodborne pathogens in canned foods and meat products is considered to be a promising and
novel method. At the same time, there will be a bit of concern about biosecurity risks.
Expert interviews and field trip
-Prof. Danting Yang
Research field: microorganism detection and rapid detection of pathogenic bacteria
To clarify the market demand of quick test kit and target users of our product, we conducted an
online interview with Prof. Yang Danting, a expert in rapid detection of pathogenic bacteria. From
the talk with Prof. Yang, we made our target users clearer and clarified the improve points for the
detection limit of our method. Moreover, we also gain some useful advices for our hardware design.
Details summary as below.
- 1 As for target users, she suggested that we could try to promote our kits to emergency
treatment agencies, disease control centers or rural areas where the related equipment are
highly in need.
- 2 As for the detection limit of our method, she pointed out that the requirement for the
detection limit depends on the target bacteria we detected. For highly pathogenic bacteria, the
detection limits need to be lower.
- 3 Finally, we asked her questions about the testing device, and she suggested that we should
achieve the detection at room temperature, which will make our detection device and results more
convenient and stable, no need to operate under specific conditions.
-Dr. Bin Hong
A PhD candidate at the School of Biological Science and Engineering, South China University of
Technology.
Four common foodborne pathogens were identified, including E. coli in our initial background checks.
To investigate and design the specifics of this project, our team conducted a more in-depth
investigation of these four bacteria. The results showed that E. coli O157 was highly pathogenic and
had a safety risk. This type of E. coli emits a strong toxin and can cause severe intestinal
symptoms, such as bloody diarrhea. Therefore, we intended to consult the relevant experts, Dr. Hong.
Through our communication with him, we further understood the complete system of the genus E. coli,
discussed and proposed the use of strain E. coli K12 instead of detection. Subsequently, we
conducted a series of investigations into E. coli K12 and the results showed that the bacteria were
in line with our current project in all aspects. Ultimately, for experimental safety reasons, we
adjusted the project design regarding the E. coli section and used the E. coli K12 strain as a test
strain for E. coli.
-Prof. Jiapeng Meng
CTI Co. Ltd
Research field: microorganism detection and rapid detection of pathogenic bacteria
In order to better understand the current fast food detection methods in reality, we interviewed
Professor Meng from CTI. Through the interview with Prof. Meng, we have a deeply understand of the
food detection and the principles of hardware design. When promoting our device to our target users,
detailed product manual is necessary to avoid misunderstanding and ensure the results is reliable.
After learning the various types of pathogens they concluded in their methods and the steps of
detecting they used in the experiment, we had a better understanding of raising detection rate of
our product.
-Prof. Ling Chen & Prof. Qinghua Ye
Research field: Detection monitoring and uses of bacteria phage.
During the field trip at Guangdong Institute of Microbiology, we had a face-to-face talk with Prof.
Qinghua Ye, who is an expert in phage, and Prof. Ling Chen who is the leader of the detection team
there. From the talk with them, we gained lots of suggestions about our hardware design and let us
further clarify how to implement our tools in real world.
- Inspiration for improving the 3D model of our product. It is suggested that the
- central lattice for sampling should remove for better detection rate. The sample may not
successfully spread from the central to four directions because of small sample quantity. So it
is better to modify the hardware model to four reaction cells
- Suggestion for the post-processing method to ensure biosafety. In our lab, we put
- most of our effort in raising the efficiency of sterilization process. Prof. Ling Chen suggested
us to make two types of products suitable for households and hospitals or some small clinics.
The one for household can be made disposable, result in an even lower input and more convenient
detecting process, changing ABS plastic into other thin and light materials that are easy to use
and destroy for normal families. For the hospitals and small clinics which have basic
laboratories, recycling product can be used for better practical uses. Instruments used for
disinfection have already equipped in these laboratories so that this type of detecting product
should be made of recyclable material that can afford high pressure and high temperature. Apart
from the points above, Prof. Qinghua Ye mentioned that our project is a great try for we high
school students to discover the innovative uses of bacteria phage.
-Dr. Zhi Pan
Huazhong University of Science and Technology
In the process of making the hardware device, we found that the initial design of the device, the
detection results can only show the presence of food-borne pathogenic bacteria through our vision,
unable to express the concentration of pathogenic bacteria with accurate data. In order to solve
this problem, we interviewed with Zhi Pan. First of all, we introduced the relevant content of our
project to Dr. Pan, explained the difficulties we have encountered at present, and asked him for
help. Subsequently, Mr. Pan gives a lot of practical suggestions, and gives us a lot of help in
software modeling. Inspired by him, we built a mathematical model of three colors and fluorescence
which made our output results more accurate, enabled us to realize data quantification. With his
help, we finally made an APP, which was convenient for users to operate. Only need to take photos
through the mobile phone, users could gain the concentration of bacteria detected.
-Mr. Cheng
- Research area: mechanical design, mechanical structure analysis and 3D modeling design
- MCL Hardware Engineer & Maker Tutor
- MSP Certified Mentor of the International Mars Society
In terms of hardware, we encountered how to design reasonably to meet the demand of portability. We
consulted Mr. Cheng. In the early stage of the food-borne pathogenic bacteria detection device, we
first need to deal with the pathogenic bacteria, after the treatment of bacteria and magnetic beads
fusion, if directly with the paper base contact reaction, the color produced by magnetic beads will
have a great interference to the final color reaction. To do this, the magnetic beads need to be
separated from the bacteria. Mr. Cheng pointed out that we can use asbestos board or heat insulation
board to build the box to keep the temperature constant. In addition, for the device that needs to
separate the magnetic beads and bacteria liquid, the vortex oscillator can be embedded directly into
the device for easy operation.
Based on Mr. Cheng's advice, we have a clearer understanding of the design of our portable device,
which has allowed us to expand the target audience of our detection device. The detection of
foodborne pathogens can also be carried out quickly and conveniently in the home living place
without the presence of professional testing personnel.
