Barb. Rodr. extract inhibiting the growth of in sliced mozzarella cheese.

The aims of this study were to verify the occurrence of in sliced mozzarella cheese marketed in Pelotas city, Brazil and perform the phenotypic and genotypic characterization of the isolates. Besides that, evaluate the susceptibility of to extract, characterize it chemically, and apply the extract in sliced mozzarella cheese contaminated experimentally with . was isolated in 5% (4/80) of cheese samples, but no gene used as marker for O157:H7 or virulence genes were detected. The isolates were susceptible to extract (MIC 15 mg mL and MBC 29-58 mg mL), and the major compounds present in the extract were Z-10-Pentadecenol (80.1%) and Palmitic acid (19.4%). In cheese, after 72 h there was a significant difference between control (2.8 log CFU cm) and treated samples with MIC, 2 × MIC, 4 × MIC and 8 × MIC (1.3, 1.4, 1.6 and 0.5 log CFU cm, respectively). The isolation of in cheese indicates fecal contamination and poor hygienic practices. extract showed antimicrobial activity against both in vitro and in situ, indicating that it can be a good alternative for inhibiting the growth of this microorganism in sliced cheese.