Bacteria are increasingly resistant to antibiotics, and existing drugs work poorly against chronic infections like those that occur in wounds, on medical devices and in the lungs of people with cystic fibrosis. For these reasons, a great deal of research is focused on finding new antibiotic compounds.
In this study, researchers took a different approach. Rather than trying to find agents that best killed bacteria in test tubes, they sought to intensify the stress imposed on microbes by one of the body's own defense mechanisms.
"The competition for iron is critical in the struggle between bacteria and host," explained the study's senior author, Pradeep Singh, associate professor of medicine and microbiology at the UW. "The body has potent defense mechanisms to keep iron away from infecting organisms, and invaders must steal some if they are to survive."
Iron is critical for the growth of bacteria and for their ability to form biofilms, slime-encased colonies of microbes that cause many chronic infections. "Because iron is so important in infection, we thought infecting bacteria might be vulnerable to interventions that target iron," explained Yukihiro Kaneko, senior fellow in microbiology at the UW and the study's lead author.
To accomplish this, the researchers used gallium, a metal very similar to iron.
"Gallium acts as a Trojan horse to iron-seeking bacteria," said Singh. "Because gallium looks like iron, invading bacteria are tricked, in a way, into taking it up. Unfortunately for the bacteria,
Source:University of Washington