Disinfectants found to create superbugs and create antibiotic resistance
New findings suggest that that use of disinfectants may be promoting growth and survival of superbugs – bacteria that become resistant to treatment with antibiotics, as well as the disinfectant being used. The findings have important implications for managing infection spread in healthcare community settings.
The findings come from researchers at the National University of Ireland in Galway. Researchers cultured the opportunistic bacteria Pseudomonas aeruginosa in the lab. They discovered that when they increasing added disinfectant to the culture; the bacteria became increasingly stronger, also surviving the antibiotic ciprofloxacin. The bacteria had not been exposed to the antibiotic but nevertheless became virulent enough to become antibiotic resistant from being exposed to small amounts of the disinfectant.
The bacteria used in the study, Pseudomonas aeruginosa, are a common cause of infection in hospitals, attacking patients with weakened immune systems. When infections occur, antibiotics are used to treat hospital acquired infections – but using disinfectants appears to promote antibiotic resistance, posing a threat to hospitalized patients.
Lead study author, Dr. Gerard Fleming, explains, "In principle this means that residue from incorrectly diluted disinfectants left on hospital surfaces could promote the growth of antibiotic-resistant bacteria. What is more worrying is that bacteria seem to be able to adapt to resist antibiotics without even being exposed to them."
The researchers used very small amounts of disinfectant, finding that bacteria adapted, promoting survival and increasing the incidence of antibiotic resistance, facilitating the emergence of superbugs. Dr. Fleming says "We need to investigate the effects of using more than one type of disinfectant on promoting antibiotic-resistant strains. This will increase the effectiveness of both our first and second lines of defense against hospital-acquired infections." Hospital infections are becoming increasingly more difficult to treat, and have been increasing in intensive care units. Antibiotic resistance from superbugs has become a growing public health concern.
Microbiology 156 (2010), 30-38; DOI 10.1099/mic.0.029751-0