Antibiotic residues in uncured pepperoni or salami meat are potent enough to weaken helpful bacteria that processors add to acidify the sausage and make it safe for consumption, according to a study conducted by researchers from the University of Copenhagen and the University College Cork.
Researchers studying the effects antibiotic residues in fermented sausages found that antibiotic concentrations within limits set by US and European Union (EU) regulators are high enough to slow fermentation, a process that acidifies the sausages and should destroy foodborne pathogens like Salmonella or E. coli.
Professor Hanne Ingmer of the Faculty of Health and Medical Sciences, University of Copenhagen is the lead author of the study. She says fermented sausages occasionally cause serious bacterial infections, but it's never been understood why that might be.
At low concentrations and at regulatory levels set by authorities, it could be seen that the lactic acid bacteria are more susceptible to the antibiotics than the pathogens are, says Ingmer. So basically, there can be a situation where residual antibiotics in the meat can prevent or reduce fermentation by the lactic acid bacteria but these concentrations do not effect survival or even multiplication of pathogens.
Hence, says Ingmer, the results show antibiotics can potentially have a paradoxical effect that would increase the risk of foodborne illness: antibiotic residues reduce the effectiveness of bacteria that should make the sausages safe but don't affect the bacteria that can make sick.
The majority of sausages are manufactured at a commercial scale. It has to be addressed whether this is a problem in a real life facility, according to Ingmer.
Source: University of Copenhagen