EFSA: 4 Antimicrobials Don’t Contribute to Bacterial Tolerance

EFSA has carried out an assessment on whether there is any increased bacterial tolerance and resistance to antibiotics from the use of four antimicrobial substances used to decontaminate poultry carcasses1. The EFSA Panel on Biological Hazards (BIOHAZ) concluded that, despite a long history of use, no published data exist to indicate that the four substances, within the proposed conditions of use, will lead to increased bacterial tolerance to these substances or to increased resistance to therapeutic antibiotics and other antimicrobial agents. The panel also encouraged further research on the likelihood of an increase in bacterial tolerance to these types of substances, and the possibility of their resistance to therapeutic antibiotics and other antimicrobial agents.

The substances are:

• chlorine dioxide
• acidified sodium chlorite
• trisodium phosphate
• peroxyacids

Such substances are presently in use in the U.S. to kill or reduce the number of bacteria, such as Salmonella or Campylobacter on poultry. At present, no such substances are authorized for use in the EU but permission may be given under EU legislation (EC Regulation No 853/2004) when preceded by a thorough scientific evaluation.

The BIOHAZ Panel noted that there was some evidence indicating bacterial tolerance to other antimicrobial substances or biocides2 which were not subject of this Opinion. However, these data were either based on laboratory experiments which do not always mirror “real-life” situations or resulted from the improper use of biocides.

EFSA delivered several opinions in 2005 and 2006 in relation to these four antimicrobial substances which looked at both the safety of using them on food and their effectiveness in killing or reducing bacteria. In evaluating the four substances, EFSA’s Panel on additives, flavourings, processing aids and materials in contact with food(AFC) concluded that, based on the data available, there was no safety concern, within the proposed conditions of use. For its part, the BIOHAZ Panel looked at the effectiveness of one of the four substances, peroxyacids, and said that, owing to lack of sufficient data available to the Panel, including those submitted by the applicant, it was unable to say if these substances effectively killed or reduced bacteria on poultry.