Foodborne pathogens are mainly pathogenic bacteria that use food as a vector of transmission. These pathogenic bacteria can survive in food or water sources and, when consumed, may lead to intestinal illness or food poisoning and, in severe cases, death［1].

 

Bacillus cereus, also known as Bacillus cactus, is a gram-positive and beta-hemolytic rod-shaped bacterium. Often found in soil and food, some strains cause food poisoning, such as Fried Rice Syndrome (FMS)［2].

Vibrio parahaemolyticus is a gram-negative bacterium that can assume various shapes such as arc, rod, filament, etc. and has no spores. Vibrio parahaemolyticus is a marine bacterium that mainly comes from seafood such as fish, shrimp, crab, shellfish and seaweed. Consumption of food containing this bacterium can lead to food poisoning, also known as halophilic food poisoning. Clinically, acute abdominal pain, vomiting, diarrhea and watery stools are the main symptoms［2].

 

Traditional culture-based methods, which are currently the gold standard for bacterial detection, are inexpensive and accurate, but are limited by laborious, time-consuming and low throughput. In recent years, a number of techniques have been developed for the rapid and sensitive detection of pathogenic bacteria, with nucleic acid-based assays and immunoassays being the most commonly used. However, polymerase chain reaction (PCR)-based nucleic acid methods usually require expensive equipment and trained operators. Conventional enzyme-linked immunosorbent assays (ELISA) are time-consuming and have relatively low sensitivity. Therefore, the development of simple, rapid, robust and sensitive assays for bacterial detection is essential［3].

 

In this project, we developed a new detection strategy for pathogenic bacteria in food: smartphone-based and bacterial binding protein colorimetric detection of Bacillus cereus (BC) and Vibrio parahaemolyticus (VP).

（*Drawing under the guidance of the subject designer - Mr. Hong Bin）

 

 

Using this assay, we can detect Bacillus cereus and Vibrio parahaemolyticus at lower concentrations without pre-enrichment, and the concentration of the bacteria in the sample can be derived by visual observation or scanning with a cell phone, which can satisfy the requirements for immediate detection (POCT).

We plan to complete two products:

1. A complete system for detecting bacterial concentration (e.g., made into a test kit);

2. A matching APP for testing.

 

［1]  Ivanova Natalia, Sorokin Alexei, Anderson Iain, Galleron Nathalie, Candelon Benjamin, KapatralVinayak, Bhattacharyya Anamitra, Reznik Gary, Mikhailova Natalia, Lapidus Alla, Chu Lien, Mazur Michael, Goltsman Eugene, Larsen Niels, D'Souza Mark, Walunas Theresa, Grechkin Yuri, PuschGordon, Haselkorn Robert, Fonstein Michael, Ehrlich S Dusko, Overbeek Ross, KyrpidesNikos. Genome sequence of Bacillus cereus and comparative analysis with Bacillus anthracis. [J]. Nature,2003,423(6935).

 

［2]  Ramírez-Orozco Martín, Serrano-Pinto Vania, Ochoa-Álvarez Norma, Makarov Roman, Martínez-Díaz Sergio F. Genome sequence analysis of the Vibrio parahaemolyticus lytic bacteriophage VPMS1. [J]. Archives ofvirology,2013,158(11).

 

［3]  Hong Bin, Li Yanmei, Wang Wenhai, Ma Yi, Wang Jufang. Separation and colorimetric detection of Escherichia coli by phage tail fiber protein combined with nano-magnetic beads[J]. Microchimica Acta,2023,190(6).