当细菌群体通过电信号达成共识，抗生素失效的新解释
In the war against bacterial resistance, a sobering mystery has long plagued clinicians: why do biofilms — those slimy, tenacious communities of microbes — survive antibiotic onslaughts that would annihilate their free‑floating cousins? A research group at the University of Buenos Aires, led by biophysicist Elena Crespo, has illuminated a startling answer. The cells within a biofilm do not merely sit in a shared goo; they communicate through coordinated bursts of electrical activity, much like neurons in a brain. By eavesdropping on these signals, the team has revealed a collective intelligence that allows bacteria to mount a unified defense, a discovery that may compel us to rethink the very nature of microbial life.
Crespo’s team cultivated intricate biofilms of Pseudomonas aeruginosa, a notorious pathogen in hospital‑acquired infections, on arrays of microscopic electrodes. When they administered a sub‑lethal dose of the antibiotic ciprofloxacin, they recorded not a muffled response but a wave of electrical depolarization that rippled outward from the initially stressed cells. The signals were propagated by voltage‑gated potassium channels embedded in the bacterial membranes — molecular gates that had previously been overlooked in prokaryotes. Within minutes, even cells distant from the antibiotic‑exposed zone exhibited metabolic shifts, slowing their growth and activating efflux pumps that expel the drug. The biofilm thus behaved as a syncytium, its component parts informed and vigilant.
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