Managing Listeria

A suggested Listeria Management Plan (LMP), which incorporates the philosophy of managing food safety based on risk assessment of the food manufacturing process and food manufacturing environment, has six key elements and is shown schematically in Figure 1. Each of these key elements then contains a series of policies/procedures/plans to support the elements objectives. The LMP should form part of the food manufacturers overall food safety plan, which will incorporate e.g. HACCP, TACCP, VACCP, PEP, traceability and product recall studies and a Crisis Management Plan. 

The first key element  of a LMP is the physical plan itself, including its scope, content, documentation, management and records. To ensure that the LMP is effectively designed and implemented, it is essential that all staff have training in Listeria, as an organism and as a risk to consumers, at a level appropriate to their responsibility in the organisation. 

The LMP recognises that there are two major components of the plan; a risk assessment of the food product and its process (key element 2) and the food processing environment (key element 3). These two risk assessments will lead to a number of controls that are required to manage the Listeria risk and these will be documented in key element 4, which includes details of how the controls will be validated, monitored and verified. An essential verification measure will be the analysis of product and environmental samples for L. monocytogenes and this is documented in key element 5. 

Key element 5 also documents how the results of the microbiological sampling will be analysed and reported internally and to customers. If all appropriate Listeria controls have been identified and are working as intended, the presence of L. monocytogenes in the product and the processing environment should be rare. If detected, however, its significance in terms of potential product recalls and plant decontamination has to be immediately determined and its presence should be investigated to identify its source and product vectors, and this is documented in key element 6. Lessons learnt from such investigations should be fed back into the LMP to better manage elements 2 and 3. 

From key elements 2-6, the roles and responsibilities of senior management, management, supervisory staff and operatives can be discerned and documented. The absolute key message of the LMP is that Listeria can only be effectively managed by teamwork and senior management, production, technical, engineering and hygiene functions are all equally responsible for its successful implementation. Hopefully this will debunk the typical food industry management initial thought that the presence of Listeria is due to poor cleaning! Element 1 finally contains details of the necessary LMP meetings and reviews, together with all records, as required to implement the plan.