Infection | Brain
The Microbial Art of Invading the Blood-Brain-Barrier
And what can we learn from their dangerous instincts?
The skull and meninges shield the brain from outside dangers such as physical impact or microbial invasion. The blood-brain-barrier (BBB) is part of the meninges that has a highly selective (‘picky’) filter that only permits specific substances to pass through.
The BBB, therefore, controls the exchange of substances between the bloodstream and the brain. “You can think of the BBB as a brick wall,” says Brandon Kim, a biology graduate student at San Diego State University. “Each cell of the BBB is a brick and these tight junctions are the mortar.”
Some microbes can outsmart the BBB and infiltrate the brain. This causes inflammation of the meninges — meningitis. As compared to viral, parasitic, or fungal meningitis, bacterial meningitis causes the highest global burden with an estimated 1.2 million cases annually. It is one of the leading causes of pathogen-related deaths worldwide, despite advances in antibacterial therapy. It has a 70% fatality rate within hours if untreated.
Even with immediate treatment, 5–40% of children and 20–50% of adults lose their lives. To make matters worse, half of the survivors suffer life-long consequences…
