Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 2/22/2006
Publication Date: 8/13/2006
Citation: Brito, J.R., Santos, E.M., Arcuri, E.F., Lang, C.C., Brito, M.A., Souza, G.N., Luchansky, J.B. 2006. A retail survey of brazilian milk and minas frescal cheese and the corresponding dairy plant producing these products to determine the prevalence and sources of listeria monocytogenes and to implement corrective measures. [Abstract] Internatinal Association for Food Protection's Annual Meeting P2-37. pg. 126. Interpretive Summary:
Technical Abstract: A study was designed to recover Listeria monocytogenes (LM) from pasteurized milk and Minas frescal cheese (MF) and to identify the sources of contamination of these products in the corresponding dairy processing plant. Fifty milk samples (9 brands, 5-7 samples per brand) and 50 MF samples (10 brands, 5 samples per brand) were analyzed for LM by a microbiological enrichment method and by PCR assay. Samples were obtained in June-September of 2005 (the dry/cold season) from 37 retail sites (chosen by stratified random sampling) located in seven areas of Juiz de Fora, State of Minas Gerais, Brazil. All 50 milk samples tested negative (<1 cfu/ml) for LM. However, 4 of 5 samples of MF from 1 brand, that being brand “F”, tested positive for LM. In October of 2005 we visited the farm/dairy that produced brand F and took samples from the milking parlor (bulk tank milk, teat cups, filters, milk buckets, and rinse water obtained from buckets; all 5 tested negative), samples from food contact and non-food contact areas of the processing plant (e.g., floors, walls, sinks, refrigeration units, molds, and excess liquid from MF on trays, in sinks, and in refrigerators; 9 of 22 sites/samples tested positive), and samples of MF (5 of 5 samples tested positive). Based on our findings, in collaboration with the producer and local health department officials, failures in the hygienic process and plant design were identified and corrected. The plant remained closed until December of 2005 when microbiological testing confirmed that the processing environment (29 samples) tested negative for LM. Moreover, analysis of MF produced in January of 2006 confirmed that all 5 samples tested negative for LM. Studies are ongoing to quantify the prevalence, levels, and types of LM in dairy products and in the processing plant to better manage the threat of listeriosis.