Evidence-Based Intervention Framework Proposal for Listeria monocytogenes in Micro and Small Meat-Processing Plants

Listeria monocytogenes poses a significant risk in meat-processing plants, especially in micro and small businesses, where structural, organisational and operational limitations make it difficult to control. Although there is evidence of its environmental distribution and recurrence, this information does not always translate into clear operational criteria for risk management. To design an intervention framework for mitigating the risk associated with L. monocytogenes in micro and small meat-processing plants, based on the integration of previously published microbiological and operational evidence, the study integrated results on environmental distribution, recurrence of isolates and risk factors identified in eight plants. Functional prioritisation criteria were defined considering hygienic zoning, the function of sites in the process flow, proximity to the ready-to-eat product, and environmental conditions favourable to "persistence". Differentiated risk scenarios and a functional hierarchy of priority intervention points were detected, prioritising site types recurrently associated with the presence of Listeria spp. and L. monocytogenes. Based on this hierarchy, the proposed intervention formulation aimed at prevention, control and environmental monitoring, adapted to the operating conditions of micro- and small-scale meat-processing plants. The proposed framework offers a transferable tool to support decisions in the management of L. monocytogenes risk in small-scale plants.