Microbiological analysis of non-industrialized cheeses commercialized in Santa Catarina, Brazil

Abstract

Background: Food contamination by microorganisms can be avoided with good hygienic practices in the production chain. Pathologies associated with cheese contamination are a problem of Public Health in Brazil, being the dairy industry the largest source of disease outbreaks caused by contamination. This paper aims to verify pathogenic microorganism occurrence in colony cheese commercialized in two municipalities of the state of Santa Catarina (SC), Brazil. Methods & Materials: From June to November 2015, a microbiological analysis of 70 cheeses sold in food stores was carried out. For the microbiological analyses, 25 g of each sample were aseptically weighed, then ground and diluted in peptone water (225 mL) at 0.1% (dilution 10-1), inserted into selenite broth specific for bacterial growth at 37 °C for 24 hours. The samples were subsequently seeded in media MacConkey agar (MC), Salmonella Shigella Agar (SS) and mannitol agar, then incubated for 24 hours in a microbiological oven. The samples showing bacterial growth were pricked in Rugai-Lysine medium to identify Gram-negative bacteria. Samples showing growth in mannitol agar with yellow colonies were classified as Staphylococcus aureus. Results: Of the 70 samples processed, 82.8% presented bacterial growth. Of the samples purchased in the municipality of Lages, 94.3% (33/35) were positive; and in the municipality of Otacílio Costa, 65.7% (23/35) were positive. There was presence of Salmonella sp., Escherichia coli, Shigella sp., Staphylococcus aureus, Klebsiella spp. and Proteus spp. Conclusion: The quality of the colony cheeses from Lages and Otacílio Costa (SC) evaluated by microbiological methods was found unfit for consumption due to indices above the limits established by the Brazilian legislation. The cheeses analyzed is a potential risk to public health.