Are there downfalls to some disinfectants?
To curb antibiotic-resistant bacteria, Marquette professors work to identify the best disinfectants for the environment.
By Natalija Popovic, communication intern in the Office of Marketing and Communication
Throughout the COVID-19 pandemic, the use of disinfectants has been widely promoted to help slow the spread of the virus. But are all the impacts of these products good?
Sales data shows that during the pandemic, people have increased the frequency at which they buy and use disinfectants. For example, according to a report from Environmental Health News, sales of Lysol wipes were up nearly 50% in spring 2020 as compared to that time in 2019.
Disinfectants, such as wipes, hand sanitizers and other personal care products, contain quaternary ammonium compounds, known as “quats,” which are charged molecules that can kill bacteria, fungi and viruses.
Dr. Chris W. Marshall, assistant professor of biological sciences in the Klingler College of Arts and Sciences, and Dr. Patrick McNamara, associate professor of environmental engineering in the Opus College of Engineering, believe, though, that increased quat levels in the environment could spur the development of antibiotic resistance in bacteria.
This means the bacteria that certain antibiotics are designed to kill can actually defeat the medications, which can lead to what has been referred to as a “superbug,” McNamara says.
“At low concentrations, quats may have the opposite effect on their intended purposes, where they could breed anti-microbial resistance which can then spread to organisms in the environment,” Marshall says.
McNamara and Marshall assembled a team to conduct research in both laboratory and real-world settings to better understand quats and identify which group of quats is least harmful to the environment and therefore least likely to create antibiotic-resistant bacteria.
The research is a continuation of research conducted over the last decade by McNamara and Marshall.
In the lab studies, McNamara says, the team operates miniature reactors that represent wastewater treatment plants. They feed the reactors with different concentrations of chemicals to measure how the chemicals might contribute to antibiotic resistance.
The team collects samples of the water every three months to determine which products and their quats are best for the environment and have the least negative effects on the efficacy of antibiotics.
Both McNamara and Marshall say the more that is known about how quats enter and persist in the environment, better decisions can be made regarding the types of products consumers use and the wastewater treatment strategies to rid of the systems of harmful quats before they can wreak havoc.
