Characterization for enterotoxin production, virulence factors, and antibiotic susceptibility of Staphylococcus aureus isolates from various foods in Portugal.
Staphylococcus aureus represents a public health challenge worldwide. The aim of this study was the characterization of different food isolates of S. aureus on the basis of their production of enterotoxins, hemolysins and resistance to antibiotics. A total of 148 coagulase-positive staphylococcal strains isolated from different food origins were identified to the species level. By multiplex PCR, 69% of the isolates were shown to be enterotoxigenic (SEs); the most common were sea seg, sea seg sei and seg sei. According to CLSI [CLSI, Clinical and Laboratory Standards Institute, 2007. Performance Standards for Antimicrobial Susceptibility Testing; Fifteenth Informational Supplement. CLSI document M100-S15. Clinical and Laboratory Standards Institute, Wayne, PA], 38% of the isolates were resistant to oxacillin (>or= 6 microg/mL; MRSA positives) but only 0.68% showed the presence of mecA gene. 70 and 73% of the S. aureus strains were resistant to beta-lactams, ampicillin and penicillin, respectively. The virulence pattern was demonstrated to be origin and strain dependent. These findings emphasise the need to prevent the presence of S. aureus strains and SEs production in foods.
Pereira
V
V
Escola Superior de Biotecnologia-Universidade Católica Portuguesa, Rua Dr. António Bernardino de Almeida, 4200-072 Porto, Portugal.
Lopes
C
C
Castro
A
A
Silva
J
J
Gibbs
P
P
Teixeira
P
P
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002611:Cheese / Q000382:microbiology; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004768:Enterotoxins / Q000096:biosynthesis* / Q000235:genetics; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D006801:Humans; D008460:Meat / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D008892:Milk / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification* / Q000378:metabolism / Q000472:pathogenicity; D037521:Virulence Factors
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004768:Enterotoxins; D037521:Virulence Factors