GRAM-POSITIVE, CATALASE-POSITIVE COCCI FROM DRY-CURED IBERIAN HAM ANDTHEIR ENTEROTOXIGENIC POTENTIAL

Iberian ham is an uncooked, cured meat product ripened under natural u ncontrolled conditions for 18 to 24 months, Gram-positive, catalase-po sitive cocci are the main microbial population in Iberian ham for most of the ripening time, Since some of these organisms are able to produ ce enterotoxins, adequate characterization and toxicological study are needed, For this, 1,327 gram-positive, catalase-positive cocci, isola ted from Iberian hams at different stages and locations, were characte rized by physiological and biochemical tests, Selected isolates were f urther characterized by guanine-cytosine (G+C) content and restriction enzyme analysis of genes coding for 16S rRNA, The toxigenic potential of these organisms was tested with specific DNA gene probes for staph ylococcal enterotoxins A, B, C, and D and confirmed by semiquantitativ e sandwich enzyme immunoassay, The majority of the isolates were ident ified as Staphylococcus spp. and Micrococcus spp, Nonidentified gram-p ositive, catalase-positive cocci which were moderately halophilic and showed a 42 td 52% G+C content were detected, A great variety of staph ylococcal strains were found within the different species at any sampl ing time, Two strains of Staphylococcus xylosus, one Staphylococcus co hnii strain, and four of the nonidentified organisms with 42 to 52% G- l-C contents hybridized with some of the DNA probes for C and D staphy lococcal enterotoxin genes, S. xylosus hybridizing with C-enterotoxin probe reacted with both C and D enterotoxins in the immunological test ; In addition, enterotoxin D was confirmed in the nonidentified strain s, Some toxigenic organisms were isolated from the final product, posi ng a health hazard for the consumer.