Misuse of Biocides in Food Production Could Harm Public

A recent study looks at how improver use of biocides in food production may endanger public health through increasing antibiotic resistance in bacteria and enhancing the formation of harmful biofilms.

"Recent scientific evidence suggests that the selective pressure exerted by the use of biocides at sub-lethal concentrations could contribute to the expression and dissemination of antibiotic resistance mechanisms," according to a press release.

As biofilms increase the risk of food contamination through the reservoir of microorganisms, biofilm formation creates a major virulence factor in human infections. For instance, it boosts operation and maintenance costs in food production with plugging filters, heat exchangers and blocking tubes in water distribution systems.

Researchers tested whether the exposure of Escherichia coli bacteria to sub-lethal concentrations of each of three food-grade biocides could result in greater antibiotic resistance or a greater ability to form harmful biofilms that survive normally lethal doses of biocides.

Background information from the study notes that exposure of the biocide sodium nitride increased resistance to 14 out of 29 antibiotic tested E. coli cells that also acquired tolerance to biocides, particularly sodium hypochlorite and sodium nitrite, along with two biocides that improve the microbes ability to grow biofilms.

However, this was not the case for all of the biocides. For instance, exposure to biocide trisodium phosphate reduce E. coli's ability to form biofilms and reduced the resistance only to the antibiotic.

"These findings are in agreement with reports of other authors, where adaptation of E. coli to both chemical and physical sub-lethal stresses has been demonstrated," write the researchers, via the release. "The increased tolerance observed suggests that the use in food environments of compounds which when used inappropriately may provide sub-lethal exposure represents a real risk for the development of adaptation to biocides."

Researchers note that the study is particularly important to promote policies that prevent improper use of biocides.

More information regarding the study can be found via Applied and Environmental Microbiology.