Cell membrane’s importance offers new strategy to fight infections

As an increasing number of infectious bacteria develop resistance to antibiotics, the hunt for new strategies to combat them becomes ever more urgent. One approach is to learn more about bacteria themselves, and, as a new study in Nature suggests, these tiny, abundant organisms harbor some secrets that we still haven't discovered.

The new research, led by bioengineer KC Huang, PhD, found that a membrane surrounding the cell wall has a more important role in bacterial survival than previously believed.

About half of all bacterial species have a thin membrane encircling the cell wall. And that sheath may even be mightier than the chunkier cell wall, the researchers discovered.

"It's humbling to think that this function had been hiding in plain sight for all these years," Huang said in a Stanford Engineering news release.

The release explains:

Over the last four years, working with collaborators from the University of California, San Francisco, and the University of Wisconsin–Madison, the group members tested the outer membrane’s structural powers.

They suddenly collapsed the pressure inside the bacteria, but instead of causing the cell wall to massively shrink, as prevailing assumptions would have predicted, they found that the outer membrane was strong enough to almost entirely maintain E. coli’s cucumber shape.

In other experiments, they put E. coli cells through two hours of rapid increases and decreases in pressure. E. coli cells normally shrug off these repeated insults and grow as if no changes at all had occurred. However, when the researchers weakened the outer membrane, cells died quickly.

'The presence or absence of a strong outer membrane is the difference between life and death,' Huang said.

Rather than just considering the chemical ingredients and reactions within a cell, the findings illustrate the importance of paying attention to bacteria's key structural features. Approaching bacteria with a structural lens could generate new ideas to combat problematic strains, the release points out.

"If we can attack the outer membrane, infectious bacteria will be pre-weakened for targeting with antibiotic treatments that disrupt cells in other ways," Huang said.