Someone once told me that they thought the new dump should be far from the Village because of the smell. A well-designed and maintained rural landfill shouldn’t smell. But smells aren’t the only thing that travels back to a community from an unhealthy dump, located no matter how far away. (Don’t forget birds and loose dogs will bring the dump back, too.)
Burgers and Flies
Grab that flyswatter! Public-health entomologists have discovered antibiotic-resistant bacteria lurking in the guts of houseflies buzzing around fast-food joints. Ludek Zurek and Lilia Macovei of Kansas State University in Manhattan, Kansas, captured more than 200 houseflies at five restaurants in a northeastern Kansas town. The entomologists isolated and cultured bacteria from the flies’ guts, then exposed the bacteria to antibiotics. Two-thirds of the bacteria survived treatment with a single common antibiotic, and, of those, half survived treatment with two or more antibiotics. Zurek and Macovei also identified genes that confer immunity in most of the resistant bacteria’s DNA.
The houseflies may have come from farms, the entomologists say. In the U. S., livestock are regularly dosed with antibiotics to encourage growth, and so their gut bacteria often evolve resistance to the drugs. Houseflies that develop in and feed on the animals’ waste swallow bacteria when they eat. Then, being long-distance aviators, they can fly to town—hence their nickname in Zurek’s lab: “flying manure.”
Houseflies enjoy many of the same foods people do, including cooked meat and sweets. And they go to the same restaurants. They eat messily, spitting and regurgitating on their meal before digging in. In the process, a housefly’s lunch—which may be your lunch, too—is doused with the contents of the fly’s gut, including any bacteria, antibiotic-resistant or not, that the fly is carrying.
As unappetizing as that may sound, most gut bacteria from flies are relatively harmless, so their immunity to antibiotics might not seem alarming. But bacteria readily exchange genes, so the gut bacteria could pass resistance genes on to nastier species, which houseflies also carry. And those little monsters can prove immune to current medical treatments—a mounting concern for physicians. (Applied and Environmental Microbiology 72:402835, 2006)