Hydrogen peroxide produced by some bacteria causes DNA double-strand breaks, cell suicide.
(June 15, 2015) A bacterium that is the most common cause of pneumonia — a leading cause of death worldwide — can damage DNA in lung cells, a new study has shown.
Researchers from the Singapore-MIT Alliance for Research and Technology (SMART) demonstrated that hydrogen peroxide secreted by some strains of Streptococcus pneumoniae causes DNA in human lung cells to suffer double-strand breaks. Such breaks sever the DNA, creating broken ends that are highly toxic to cells, leading to cell suicide, or apoptosis.
“Secretion of hydrogen peroxide damages the DNA of lung cells, crippling the lungs' defenses against invasion and making it easier for the bacteria to get into the bloodstream,” says Bevin Engelward, the paper’s senior author and a professor of biological engineering at MIT.