Evaluation of the Detection Methods used for Investigation of Listeria and Listeria monocytogenes This study investigated the occurrence of Listeria spp. in samples of fresh cheese and ricotta comparing the results obtained using the conventional methodology (ISO 11290-1) and automated enzyme immunoassay systems (mini- VIDAS®LIS, mini-VIDAS®LMO2, mini-VIDAS®LDUO-LIS and mini-VIDAS®LDUO-LMO). The conventional method was used as gold standard for the methods comparisons. The sensitivities for the identification of Listeria by mini-VIDAS®LIS and mini-VIDAS®LDUO-LIS were 73.3% and 64.7%, respectively. For L. monocytogenes identification the sensitivities were 83.3% (mini-VIDAS®LMO2) and 62.5% (mini- VIDAS®LDUO-LMO). The specificity parameter obtained by the mini-VIDAS® systems ensured the detection of the target microorganism.