Microbiological criteria are no longer in the vanguard of the battle to control foodborne pathogens. Setting maximum permitted levels for Salmonella or Listeria contamination in food doesn’t achieve anything in itself other than necessitate a lot of time consuming and costly testing and create the potential to waste a lot of ‘out of spec’ product. It’s much better to tackle the causes of contamination directly, using criteria and testing to verify success. But a new report from a Dutch research institute suggests that microbiological criteria still have an important role to play in tackling a serious problem.
The Dutch National Institute for Public Health and the Environment (RIVM) has been considering the issue of Campylobacter contamination in chicken and has come up with a report entitled “Microbiological Criteria as a Decision Tool for Controlling Campylobacter in the Broiler Meat Chain.” The thinking is that many cases of Campylobacter infection are contracted in the home by cross contamination from raw chicken to foods that are eaten uncooked. High levels of the bacteria in chicken make such a scenario much more likely when people preparing food don’t stick to good hygiene practice – and let’s face it, that applies to almost all of us at some time.
The authors of the RIVM report have worked out that keeping contamination below 1000 cfu/g in chicken meat cuts the risk considerably and could reduce human infection rates by two thirds. Applying such a limit would encourage slaughterhouses to implement best hygiene practice, which we know is important in reducing contamination during processing. A stricter limit of 100 cfu/g would reduce the risk to almost nothing, but would mean discarding more than half of production.
Would it work? The idea certainly makes a lot of sense and the principle of setting performance targets is a proven means of generating improvements in hygiene practice. The tools to meet the 1000 cfu/g standard are already available and the potential benefits seem to outweigh the costs to industry. But how is the standard to be enforced? As I have observed in the past, test methods for detecting Campylobacter can be problematic, while counting the bacteria accurately enough to apply numerical criteria is more difficult still. But if labs can validate a suitable protocol – perhaps PCR-based – it could certainly be worth a try.