Isolation and characterization of Listeria monocytogenes in dairies from Campinas region

Abstract

The foodborne illness are considered a worldwide concern. The Listeria genus contains the important food pathogen L. monocytogenes which can cause outbreaks of listeriosis in humans and animals. Despite reported low incidence, it is a disease of great importance due to its mortality rate. L. monocytogenes can be transmitted by milk and dairy products, as found favorable conditions to develop the dairy production chain, so it is considered one of the major food security problems. Listeria sp has demonstrated resistance to antibiotics and is a factor of concern to public health. The objective of this research project will be: to isolate and to characterize strains of Listeria monocytogenes by samples of raw milk, paseteurizado milk, swabs of equipment surfaces and utensils and product type cheese mines, in 6 dairy in the Campinas region. For the isolation of L. monocytogenes will be used medium Listeria Enrichment Both (LEB) to enrichment. Both swabs and samples will be incubated in the broth for 4 hours at 30°C. Subsequently antibiotics will be added with further 44 hours incubation. From the broth, samples are striated in OXFORD agar and characterize strains will be tested by gram staining and motility testing. The search for virulence genes by PCR and phenotypical resistance to antimicrobial isolates will be performed. Antimicrobial activity of some essential oils against L. monocytogenes isolate will also be tested.