Team:BYU Provo/Project/Background

Bacteriophages

Cholera

Bacteriophages

Phage as an Organism

Bacteriophages are viruses that infect bacteria. They are composed of a capsid and a tail made of protein. Inside the capsid, bacteriophages have either a DNA or RNA genome. Because they are so simple, they cannot replicate on their own. To do so, a bacteriophage must attach to a bacterial cell membrane and inject its genome into the cell. The bacterial cell's machinery will replicate the genome and produce the viral proteins. These come together to make new bacteriophage progeny that will subsequently exit the cell.

Traditional Use of Phage

Emerging Use of Phage

Cholera

Cholera, the Disease

Quorum Sensing

Quorum sensing is the cell-to-cell signaling system that allows for coordinated behavior between bacteria through the secretion and detection of signaling molecules termed autoinducers. Some autoinducers are specific to a certain bacteria, while others are detectable by a broad range of bacteria. The N-acyl-L-homoserine lactones (AHLs) are a class of autoinducer secreted by many Gram-negative bacteria, including Vibrio cholerae. While Escherichia coli does not produce AHLs, it does have the SdiA receptor necessary to detect these autoinducers. The binding of AHLs from V. cholerae to the SdiA receptor on E. coli triggers a signal cascade that activates the transcription of quorum sensing linked genes in E. coli. By inserting our target genes into the quorum sensing linked section of E. coli’s DNA, we can design a specific response to the detection of V. cholerae by E. coli.

Biofilm

Use of Phage in Combat