Reducing the Risk of Listeria monocytogenes in Rural Artisan Cheese in Southern Chile through Surveillance and Extension

Introduction: In southern Chile many rural families raise dairy cows, and to add value to their milk, many also produce cheese. Most of these small cheese makers lack the infrastructure and training to make safe cheese products. The cheese is typically sold to neighbors or through informal markets and thus there is no inspection of these products. The likelihood of Listeria monocytogenes contamination and consequent risk of listeriosis through the consumption of these artisan cheeses is unknown

Purpose: The purpose of this study was to develop a surveillance program of Listeria monocytogenes in artisan cheese in southern Chile.

Methods: A total of 40 small cheese producers in the Región de los Ríos, Chile, were included in the project. Each cheese location was georeferenced and a check-list was used to characterize infrastructure, processing, GMP, and SOPs. We sampled each producer four times in 2016. If Listeria was detected, we conducted environmental sampling and SOP training. Listeria strains were subtyped with PFGE to identify contamination sources and to inform corrective actions.

Results: There was considerable diversity of production practices and infrastructure among the 40 producers, and only 10 fulfill the requirements necessary to obtain a Chilean permit to produce cheese. Cleaning and sanitation, pest control, and training were identified by the producers and the check-lists as the main needs. Listeria was identified in 19 cheese samples from 5 producers. Identical PFGE patterns were found in food contact surfaces and in contaminated cheeses. Corrective actions controlled contamination in 3 producers. The project developed a GMP manual, a pilot plant design and an investment plan for improving the infrastructure and equipment of these small producers.

Significance: Our study has implemented a sustainable system that improves the livelihood of rural cheese producers and reduces the likelihood of Listeria contamination in artisan cheeses in southern Chile.