Studying biocides and antibiotic resistance

The widespread use of antibiotics has led to the development of antibiotic-resistant microorganisms. This issue is also relevant to anti-microbial biocides used in disinfectants. Tests have shown that bacteria treated with non-lethal doses of biocides may develop resistance to antibiotics without developing resistance to the active biocidal substance.

The Danish Environmental Protection Agency funded project will examine the effects of three different biocides – benzalkonium chloride, hydrogen peroxide, and nanosilver – on two pathogenic bacteria that have received media attention due to serious outbreaks:

• Listeria monocytogenes, which can cause Listeriosis – a foodborne bacterial infection that is especially dangerous to pregnant women and people with impaired immune systems
• Staphylococcus aureus, which can result in Staphylococcal infections – including life-threatening Methicillin-resistant Staphylococcus aureus (MRSA) infections

As part of the project, entitled ‘Biocides – Risk factors and Resistance’, we will develop a modelling tool to assess how and how quickly antibiotic-resistant genes spread in hospital environments. 

The results of the project (expected at the end of December 2016) will make it easier to determine the risk of biocidal substances developing resistance to antibiotic.