Scientist from the Division of Infectious Disease at Emory University School of Medicine and The Emory Vaccine Center have shown that Francisella novicia, a close relative to the bacteria that causes Tularemia as well as Neisseria meningitidis the causative agent of meningitis encode specific genes in the CRISPR system that contribute to the bacteria’s pathogenesis. The CRISPR system (Clustered Regularly Interspaced Short Palindromic Repeats) is like an immune system for bacteria in which DNA in the CRISPR system encode genes that can prevent phage infections. The CRISPR system also encodes a gene that prevents the expression of a lipoprotein, a protein expressed as part of the bacterial cell membrane. When this gene is mutated, then the lipoprotein is uncontrollably expressed and leads to decreased adherence, invasion and replication in human cells by the bacteria. Other bacteria also contain the CRISPR system including Streptococcus and Listeria bacteria. This research is important for understanding host-pathogen interactions and may lead to new therapeutics against these pathogens.