We've all heard of the five-second rule when having dropped food on the floor—if you pick it up before five seconds have passed, it's safe to eat. In recent years, scientists have put that folk wisdom to the test and the results fell somewhere in the middle. If bacteria are present on the floor, researchers found that five seconds is plenty of time for it to attach to your food. However, most floors harbor very little bacteria, so unless you're unlucky enough to drop your toast on a tiny patch of e. coli, you'll probably be fine to eat it. If you were to drop that bread on your keyboard, though, that's another story. You'd maybe want to back away slowly and reach for the nearest tongs.

In a surprising twist of nature, a particular strain of bacteria could hold the key to keeping perishables free from food poisoning. Isolated from lactic acid in raw Macedonian sheep's milk, these particular enterococci bacteria produce a handful of compounds deadly to related bacterial strains, such as listeria, which happens to be quite bad for humans and a frequent source of food poisoning. The compounds, called bacteriocins, work like a narrow spectrum antibiotic to keep listeria at bay.

We’ve been talking a lot lately about bacterial resistance to drugs, most specifically as bacteria approach the limits of our treatments of last resort. As a consequence of the diminishing returns on traditional families of antibiotics, scientists have turned their focus to more novel approaches for combating infection. The work has been aimed at better understanding the interaction between our immune system and particular bacterial strains. Most recently, a team of researchers at the University of Washington have discovered just how the common staph infection resists our defenses.

Humans are in an escalating battle with bacterial infections. Our last lines of antibiotic defense are increasingly becoming our only lines. Bacteria have demonstrated an adept ability to mutate and foil drugs at a pace which nearly bests our research and development efforts. However, a new class of molecules recently synthesized by researchers at Stanford University is
showing early promise in fighting off infection in a manner unlike any other.

It’s a drizzly morning on New York’s Upper East Side, and Rockefeller University microbiologist David Thaler is sipping a double espresso amid the retro-hippie pillows and dangling paper stars of Java Girl, a favorite haunt of the neighborhood’s brainiac Nobel laureates, aging poets and famous entertainers. Thaler somehow manages to embody all three—a long, graying ponytail curling down the middle of his back, wire-frame glasses askew over expansive brown eyes, and a schnozz to rival an Einstein, Ginsberg or Allen. Thaler is one of the leading cheerleaders for a new field of biotechnology aimed at engineering the bacteria inside us to deliver drugs, destroy tumors, actively fight infection, and even vaccinate against their disease-causing kin.