Materials and methods
2.1. Strains
The study was conducted with a pool of six Listeria monocytogenes
strains (five meat isolates and one ATCC 7644 strain).
Four meat isolates belong to the culture collection of the Food
Research Center, University of Sao Paulo, Sao Paulo, Brazil, and thefifth isolatewas donated by Fundaç~ao Oswaldo Cruz, Rio de Janeiro,
Brazil. Stock cultures were maintained at 80 C in Brain Heart
Infusion (BHI - Oxoid, Basingstoke, UK) with 10% glycerol (v/v).