Occurrence of Listeria monocytogenes in cheese and ice cream produced in the State of Paraná, Brazil

Abstract

The occurrence of Listeria monocytogenes in Brazilian ice cream and in some soft and semi-soft cheeses produced and sold in the State of Paraná, Brazil was evaluated. Ninety samples of cheese and sixty samples of ice creams were analyzed following the guidelines outlined by the official institutes, AOAC and FDA. In the ice cream samples no isolation of Listeria spp. was found. The percentage of these ninety samples of cheeses positive for Listeria spp. was 12.20%. Listeria monocytogenes was detected in six (6.70%) of the same samples. The presence of Listeria innocua was five (5.50%) in the samples analyzed was also observed. According to the results of the work it is possible to presume that there is a potential health risk to the brazilian population, heightened by aging and the increase in immunodepressed. These results indicate the need for the implementation of monitoring of these microorganisms as much by producers as by health inspectors. The results also show that the VIP (visual immunoprecipitation assay) is a viable triage method of contaminated samples for the liberation of products for commercialization, as it is quick, reliable and does not require additional equipment other than that normally found in production labs, while presenting reliable results.