New research shows that drug-resistant bacteria can thrive in sink drains even after deep cleaning.
Beware the hospital sink drain. A new study out this week shows that these drains can be a common source of scary, drug-resistant pathogens, even after deep cleaning.
Researchers at the University of the Balearic Islands in Spain led the study, published Friday in Frontiers in Microbiology. They analyzed bacteria collected from drains around a single, well-maintained hospital and unearthed a rich diversity of troublesome microbes, including superbugs that can resist several antibiotics at once. The findings suggest that stemming the spread of these bacteria within hospitals is even harder than expected, the researchers say.
Antibiotic resistance is one of the most pressing public health issues of our time. It’s already estimated that these infections kill at least 1.27 million people worldwide annually, including 35,000 Americans a year. And studies have projected that drug-resistant bacteria will eventually match or even surpass the current annual death toll of cancer (roughly 10 million deaths a year) in the next few decades.
Hospitals and other health care facilities are common breeding grounds of antibiotic resistance for several reasons. Antimicrobials are widely used in these places, directly fueling resistance. Patients are also in poorer health than usual, making it easier for infections to prosper and spread like wildfire between people. Given these known risks, hospitals and their employees routinely take steps to mitigate antibiotic resistance, which often includes the deep cleaning of areas where bacteria can linger, such as plumbing systems and sink drains.
The researchers wanted to test how effective these protective measures truly are. They analyzed sink drains from a single university hospital on the island of Majorca that was built in 2001. According to the researchers, the hospital routinely cleans its sinks and drains with bleach, further disinfects them with pressurized steam and chemicals every two weeks, and treats its piping with chlorine once a year.
From February 2022 to February 2023, they collected (using cotton swabs) and genetically sequenced bacterial samples from six sink drains in five wards: two from ICU units, one each for hematology, short stays, and general medicine; and a microbiology lab.
All told, they identified 67 different bacterial species from the drains. While there were some differences between the wards, all the drains contained a wide range of bacteria, including the newer ICU unit that came into o