How Bacteria get into Brains to Cause Meningitis

An international collaboration between medical researchers may have identified how meningitis causing bacteria cross from the blood into the brain, paving the way for new strategies to prevent this fatal disease, the Society for General Microbiology’s Spring Meeting in Edinburgh heard today, Tuesday 8 April 2003.

“Almost every known bacteria which attacks people could potentially cause meningitis,” says Professor Kwang Sik Kim of John Hopkins University, Baltimore, USA who worked on this issue for more than 20 years. “But it was unclear why only a relatively small number of bacteria cause most cases of meningitis.”

Most cases of bacterial meningitis develop from infections in the bloodstream, but doctors did not know how the bacteria got from the blood into the brain itself. Using well known bacteria called E.coli the researchers have shown how they cross the blood to brain barrier by first sticking to the cells in the barrier and then invading them to pass through as live bacteria.

“In spite of advances in antibiotics and improved supportive care in hospitals, meningitis continues to kill thousands of people, almost all children and young adults, every year,” says Professor Kim. “If we are to develop new treatments such as immunotherapy, or vaccines which can prime the body to prevent the bacteria from invading, we need to fully understand how these bacteria work. This investigation has taken an important step down that path.”