Safety-related properties of staphylococci isolated from food and food environments

摘要

Aims: To test some safety-related properties within 321 staphylococci strains isolated from food and food environments.Methods and Results: The isolates were identified as Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Staphylococcus pasteuri,Staphylococcus sciuri, Staphylococcus warneri and Staphylococcus xylosus. Decarboxylaseactivity was quite common for the various Staphylococcus spp., andtyrosine was the most frequently decarboxylated amino acid. The frequency ofantibiotic resistance was highest in Staph. pasteuri and Staph. xylosus. Several ofthe isolates were tolerant to QAC compounds, and in some cases, QAC tolerancewas present in antibiotic-resistant strains. Most of the strains displayedmoderate to high adhesion rates to stainless steel and Teflon. The strains thatreadily formed biofilms belonged to the species Staph. aureus, Staph. epidermidisand Staph. pasteuri.Conclusions: An high incidence of some safety hazards was found within thestaphylococcal strains of food origin tested in this study. In particular, aminoacid decarboxylase activity and biofilm-forming ability were common withinstrains, and antibiotic resistance and tolerance to QAC-based compoundsoccurred frequently as well. These characteristics are an important safety concernfor food industry.Significance and Impact of the Study: This work gives a first picture of safetyhazards within staphylococcal species isolated from food environments. Thepresence of disinfectant-resistant staphylococci is a concern because resistancecan be genetically transferred between the various Staphylococcus species. Thiscould lead an increase and spread of resistant enterotoxic staphylococci and . orpathogenic staphylococci.