According to the report published in the journal Nature, researchers at Tufts University in the US were initially analyzing the DNA sequences of a bacteriophage, a virus that infects a bacteria, taken from the stool samples of cholera patients in Bangladesh.
The researchers discovered genes of a functional immune system that was limited only to some types of bacteria. The researchers found that only those viruses that have this type of immune system can kill the cholera causing bacteria.
"The immune system allows the phage to target and destroy specific inhibitory genes of the host cell by literally cutting the target genes into pieces. By disarming these genes, the phage essentially disarms the host cell, and can then proceed with the infection and kill the host cell", lead researcher Kimberley Seed said.