Related Experiment Video
Updated: May 12, 2026

Oral Transmission of Listeria monocytogenes in Mice via Ingestion of Contaminated Food
Published on: May 6, 2013
Prevalence of Listeria monocytogenes in Idiazabal cheese
1Department of Inmunology, Microbiology and Parasitology, Faculty of Pharmacy, University of the Basque Country, UPV/EHU, Spain.
Introduction:
Raw-milk cheese has been identified in risk assessment as a food of greater concern to public health due to listeriosis.
Objective:
To determine the prevalence and levels of Listeria monocytogenes in semi-hard Idiazabal cheese manufactured by different producers in the Basque Country at consumer level.
Methodology:
A total of 51 Idiazabal cheese samples were obtained from 10 separate retail establishments, chosen by stratified random sampling. Samples were tested using the official standard ISO procedure 11290-1 for detection and enumeration methods.
Results And Conclusion:
All cheese samples tested negative for L. monocytogenes. However, 9.8% tested positive for Listeria spp., different from L. monocytogenes. Positive samples came from two brands, two were natural and three were smoked. The presence of Listeria spss. suggests that the cheese making process and the hygiene whether at milking or during cheese making could be insufficient.
Related Concept Videos
Microbes in the Production of Fermented Foods
Microbes in Food Production
Investigation of Disease Outbreaks
Microbial Spoilage of Food
Microorganisms in Agriculture and Food industry
Microbes in Beverage Production

