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Aims: Evaluation of the occurrence of most known staphylococcal enterotoxin (SE) genes, egc (enterotoxin gene cluster) and TSST1 (toxic shock syndrome toxin 1) gene in both coagulase-positive (CPS) and coagulase-negative (CNS) staphylococcal strains isolated from meat and dairy products. Methods and Results: Specificity and reliability of the PCR detection methods used were ascertained by using nine reference strains of Staphylococcus (S. aureus) harbouring SE genes (seA to seE; seG, seH, seI, seM, seJ, seN and seO) and egc (containing the following sequence of genes: seO, seM, seI, uent1, uent2, seN and seG). Of 109 wild Staphylococcus spp. strains analysed, only 11 S. aureus strains were SE and/or TSST1 PCR-positive. The last 11 strains also appeared to harbour the egc. Restriction endonuclease analysis of part of the egc of both reference and wild strains showed that different variants of the egc exist. Moreover, nucleotide sequences of seG and seI indicate that the egc of the strain AB-8802 is characterized by the presence of variants of these enterotoxins (seGv and seIv). Conclusions: The occurrence of SE genes in CNS and other non-S. aureus species isolated from Napoli-type salami, raw water buffalo milk and natural whey cultures used for mozzarella cheese manufacturing is very rare. Significance and Impact of the Study: During this study it was shown that at least five different egc may exist in S. aureus. A thorough study of egc polymorphism should provide further insight into the phylogenetics of the egc.

Aims: Evaluation of composition and evolution of the coagulase-negative staphylococci (CNS) communities in two traditionally fermented sausages (salsiccia and soppressata lucana) produced in Basilicata, southern Italy. Methods and Results: A culture-dependent approach based on isolation on selective media and identification with phenotypic and molecular methods was used. Phenotypic data of 471 strains were analysed by multivariate statistical methods by using 28 strains from culture collections and 48 strains identified by molecular methods (such as 16S rDNA sequencing, species-specific PCR assays, intergenic spacer region-PCR and PCR-denaturing gradient gel electrophoresis) as a reference. The CNS microflora of the sausages was found to be dominated by different biotypes of Staphylococcus xylosus (51AE2%), followed by S. pulvereri/vitulus, S. equorum and S. saprophyticus (13AE4, 10AE2 and 10%, respectively). Other species (S. succinus, S. pasteuri, S. epidermidis, S. warneri and Macrococcus caseolyticus) were also present at lower levels. Identification of 25% of the isolates was impossible. Conclusions: The composition of CNS communities varied significantly with sausage type, plant and ripening time and clear differences were found among communities of salsiccia and soppressata at the end of ripening. Significance and Impact of the Study: Phenotypic characterization, supported by molecular and statistical analyses, can be considered a useful approach for typing a large number of isolates and for monitoring the evolution of staphylococcal communities during sausage fermentation but does not always provide a satisfactory identification of the isolates.

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