Listeria monocytogenes in ready-to-eat, sliced, cooked ham and salami products, marketed in the city of São Paulo, Brazil: Occurrence, quantification, and serotyping

The preference for ready-to-eat sliced foods may pose an increased risk for food-borne diseases, and a major concern is the presence of Listeria monocytogenes. L. monocytogenes was assessed in two types of products: cooked ham and salami. One hundred and thirty samples of each product were acquired in retail shops in the city of São Paulo and submitted to laboratory analysis. The rate of positives was significantly higher in salami samples than in ham samples (6.2% and 0.8%, respectively). L. monocytogenes counts in salami samples varied between <10 and 1900 colony-forming units per gram (CFU/g). The serotypes found in both products were as follows, according to incidence: 4b (37.5%), 1/2b (25%), 3b (25%), and 1/2c (12.5%). Based on the results of the present study, the authors suggest that the risk of listeriosis resulting from the consumption of salami is higher than that associated with the consumption of cooked ham.