New research suggests that Acinetobacter baumannii, a growing problem in healthcare settings, can naturally abandon its ability to fight antibiotics, according to a news release. A. baumannii, which is inherently resistant to multiple antibiotics, is commonly found in soil and water. While there are many species of Acinetobacter, A. baumannii accounts for about 80% of reported infections, according to the CDC.
Outbreaks of Acinetobacter infections typically occur in ICUs and other healthcare settings. The research, published July 13 in The Proceedings of the National Academy of Sciences Online Early Edition, suggests it may be possible to impede the spread of these infections without developing new antibiotics, according to a research team from Washington University School of Medicine in St. Louis.
Bacteria have the capacity to kill off other bacteria. However, in order for A. baumannii to kill other bacteria, it must abandon its ability to repel antibiotics, according to the release. “If we can identify ways to force the entire population of drug-resistant bacteria to undergo this change, we stand a better chance of fighting the growing problem of antibiotic resistance,” first author Brent Weber, a graduate student, said in the release. “Instead of looking for new antibiotics, we could restore bacteria’s vulnerability to antibiotics we already have.”
Costly trade-off for bacteria
The researchers studied samples of A. baumannii isolated from a 2012 outbreak at a Canadian hospital in which four patients became infected, and one died. The researchers expected the bacteria to kill other bacteria by producing and injecting a poison, allowing the A. baumannii infections to spread. However, the researchers found that the bacteria’s poison injection system was disabled in most of the samples by bacterial DNA known as plasmids, which also carried genes that enabled the bacteria to resist antibiotics, according to the release. Disabling or deactivating plasmids will turn on the poison injection system, but will turn off the antibiotic-resistance genes, making the bacteria vulnerable to antibiotics.
Similar results were found after studying A. baumannii samples from other outbreaks worldwide. “This appears to be a common strategy for these bacteria in different parts of the world, and further study could help us understand how bacteria evolve into superbugs that are resistant to many forms of treatment,” senior author Mario Feldman, PhD, associate professor of molecular microbiology, said in the release. “This knowledge could lead to more effective treatments and better strategies for preventing the development of superbugs.”
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