ABSTRACT
Using phenotype techniques, characterization was made to species and serovar of 3,112 strains of Listeria, isolated from different sources of infection such as human (247-7.9 percent) and animals (239-7.6 percent), as well as from various routes of infection, including food (2,330-74.8 percent) and environmental constituents (296-9.5 percent), all coming from different regions of the country and collected during the period 1971-1997. The following species were recovered in the cultures analysed: L. monocytogenes (774-24.8 percent), L. innocua (2,269-72.9 percent), L. seeligeri (37-1.1 percent), L. welshimeri (22-0.7 percent), L. grayi (9-0.2 percent), and L. ivanovii (1-0.03 percent). L. monocytogenes was represented by ten serovars, the most prevalent being 4b (352-11.3 percent), 1/2a (162-5.2 percent), and 1/2b (148-4.7 percent). The predominant serovar in L. innocua was 6a (2,093-67.2 percent). Considerations about laboratory methods for diagnosis and epidemiological aspects are presented on the basis of the results obtained.