Separating the good from the bad in bacteria
There are good bacteria and there are bad bacteria — and sometimes both coexist within the same species. Take, for instance, Pseudomonas aeruginosa, a microbe common in soil and water. This bacterium has been found to colonize medical equipment in hospitals and clinics around the world, and can live benignly in healthy individuals. But the bug poses a risk to those with weakened immune systems, and can turn pathogenic in patients with cystic fibrosis, forming thick layers of mucus in the lungs.However, determining whether a bacterium is harmful typically requires growing cultures from samples of saliva or blood — a time-intensive laboratory procedure. Now MIT researchers have developed a new microfluidic device that could speed the monitoring of bacterial infections associated with cystic fibrosis and other diseases. The new microfluidic chip is etched with tiny channels, each resembling an elongated hourglass with a pinched midsection. Researchers injected bacteria through one...