某些持续性感染可能因细菌“互帮互助”导致

New research to be published January 13 in the journal Scientific Reports shows that some bacterial cultures adopt an all-for-one/one-for-all strategy that would make a socialist proud in preparing for the possibility of an antibiotic onslaught. The findings could have application for how persistent infections like those associated with cystic fibrosis are treated. 

The paper, by three researchers at the University of Vermont, uses a series of time-lapse videos to show that single cells within a community of bacteria randomly use a cascade of proteins to become more or less antibiotic resistant, even when the community is not threatened by an antibiotic. A bacterial colony can regenerate if only a few cells survive antibiotic treatment. 

"It's costly from a metabolic standpoint for a cell to express the proteins that enable it to be resistant," said Mary Dunlop, assistant professor in the university's College of Engineering and Mathematics Sciences, and the paper's corresponding author. "This strategy allows a colony to hedge its bets by enabling individual cells within a population to assume high levels of resistance while others avoid this extra work." 

Previous research has demonstrated that, when exposed to some antibiotics, all the cells within a bacterial population will use the protein cascade strategy, activated by a mechanism called MarA, to become resistant. 

But the new study is among the first to show that colonies use the protein cascade strategy even when they are not under threat. 

"This transient resistance, distributed in varying degrees among individual cells in a population, may be the norm for many bacterial populations," Dunlop said.