How bugs overcome host defenses

bacteria
Credit: CC0 Public Domain

Bacterial pathogens must acquire nutrient metals from the host to survive and cause disease. To counter infection, hosts attempt to starve bacteria by hiding metals away in a process called "nutritional immunity." Bacteria are wily foes though, and they change in order to survive metal starvation.

In a series of studies, Eric Skaar, Ph.D., and colleagues have characterized how A. baumannii—a leading cause of ventilator-associated pneumonia—responds to zinc starvation.

The researchers discovered that during zinc starvation, A. baumannii increases expression of the gene for a -modifying protein they named ZrlA. They show that missing the gene for ZrlA had leaky cell walls, and that these defects sensitized A. baumannii to antibiotics in vitro and in an animal model of pneumonia. They also discovered metabolic changes in A. baumannii in response to zinc starvation.

The studies, published in Cell Reports and Cell Chemical Biology, highlight the therapeutic potential of targeting proteins that respond to metal starvation, such as ZrlA, to treat bacterial infections.


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More information: Zachery R. Lonergan et al. An Acinetobacter baumannii, Zinc-Regulated Peptidase Maintains Cell Wall Integrity during Immune-Mediated Nutrient Sequestration, Cell Reports (2019). DOI: 10.1016/j.celrep.2019.01.089

Jiefei Wang et al. Multi-metal Restriction by Calprotectin Impacts De Novo Flavin Biosynthesis in Acinetobacter baumannii, Cell Chemical Biology (2019). DOI: 10.1016/j.chembiol.2019.02.011

Journal information: Cell Reports , Cell Chemical Biology

Citation: How bugs overcome host defenses (2019, April 15) retrieved 18 June 2019 from https://phys.org/news/2019-04-bugs-host-defenses.html
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