EVANSTON, III — It’s present in all of our homes, lurking behind every small corner or tiny nook the vacuum just can’t quite reach. Dust is an unavoidable tenant in our living spaces, and just as soon as we find the time to clean it all up, there is usually more on the way to take its place. Now, an unsettling new study conducted at Northwestern University finds that bacteria living within household dust are capable of spreading antibiotic-resistant genes.
Researchers found that bacteria in dust can swap their genes, which sometimes include antibiotic-resistant properties, with neighboring bacteria in nearby dust. While the majority of bacteria found in dust are ultimately going to be harmless, the study’s authors believe these antibiotic resistant genes may potentially spread to the occasional pathogen found in dust bacteria. So, if that pathogen were to eventually make it’s way into a human, the subsequent illness would be much harder to treat.
“This evidence, in and of itself, doesn’t mean that antibiotic resistance is getting worse,” comments Northwestern’s Erica Hartmann, the study’s leader, in a release. “It’s just one more risk factor. It’s one more thing that we need to be careful about.”
Bacteria are capable of sharing their genes two ways. The first, called dividing, is described as essentially having a baby. The second method is referred to as horizontal gene transfer, and occurs when a bacterium copies its own genes and exchanges them with a neighboring bacterium. Horizontal gene transfer is considered by the research team to be the primary way in which antibiotic resistant genes are spread among species.
It’s been well established that bacteria are capable of sharing various types of genes, so long as the genes on the move have mobile DNA segments. However, this set of research is the first to establish that that antibiotic-resistant genes found in dust are capable of such a feat.
“We observed living bacteria have transferrable antibiotic-resistance genes,” Hartmann says. “People thought this might be the case, but no one had actually shown that microbes in dust contain these transferrable genes.”
While it isn’t necessarily common for pathogens to be found in household dust, it isn’t unheard of either. These infection causing pathogens may hitch a ride into people’s home through a variety of ways, such as on shoes, and then go on to interact and exchange genes with existing bacteria.
“A nonpathogen can use horizontal gene transfer to give antibiotic resistance genes to a pathogen,” Hartmann adds. “Then the pathogen becomes antibiotic resistant.”
Interestingly, Hartmann and her team say that bacteria share genes frequently while indoors because being cooped up inside is actually quite stressful for them. For the average bacterium, an indoor environment is often too dry, too cold, and lacking in adequate food sources.
For what it’s worth, researchers also recommend dusting with a wet cloth instead of antimicrobial solutions, because these products can actually make bacteria more antibiotic-resistant.
“Microbes share genes when they get stressed out,” She concludes. “They aren’t equipped to handle the stress, so they share genetic elements with a microbe that might be better equipped.”
The study is published in PLOS Pathogens.