title: Differentiation of toxigenic Staphylococcus aureus in staphylococcal isolates from prepared and frozen foods by combined arbitrarily primed polymerase chain reaction and DNA probe.
abstract: In prepared and frozen flamenquín and hake fish fingers Staphylococcus aureus as sanitary hazards have been detected. In the present work, a combined method that includes an arbitrarily primed PCR (AP-PCR) and a mixed DNA probe hybridisation designed for the enterotoxigenic genes sea, seb, sec, and sed will be assayed to differentiate enterotoxigenic S. aureus from other staphylococcal species isolated during the processing of prepared and frozen foods. From the protocols tested for the AP-PCR, the highest number of amplification bands showing the best resolution was achieved at 30 degrees C annealing and 35 degrees C extension temperatures. Several staphylococci identified by a biochemical test as S. aureus showed in the AP-PCR analysis different banding patterns to the references S. aureus. The isolates, were investigated by slot blot hybridisation for genes encoding A, B, C, and D staphylococcal enterotoxins to determine their enterotoxigenic potential. Several isolates characterised by the AP-PCR analysis as S. aureus hybridised with the DNA probe mixture. The combined AP-PCR and DNA probe hybridisation assayed was able to differentiate toxigenic S. aureus from other staphylococcal species from prepared and frozen foods. This method could be considered as microbial quality assurance in these products.
authors.affiliation: Higiene y Tecnología, de los Alimentos, Escuela de Ingenierías Agrarias, Universidad de Extremadura, Badajoz, Spain. mdeguia@unex.es
authors.forename: Maria G
authors.initials: MG
authors.lastname: Córdoba
authors.forename: Rafael
authors.initials: R
authors.lastname: Jordano
authors.forename: Emilio
authors.initials: E
authors.lastname: Aranda
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Benito
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Córdoba
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D017931:DNA Primers; D015342:DNA Probes; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004768:Enterotoxins / Q000235:genetics* / Q000302:isolation & purification; D005396:Fish Products / Q000382:microbiology; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D016133:Polymerase Chain Reaction / Q000379:methods; D013210:Staphylococcus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D013211:Staphylococcus aureus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D017931:DNA Primers; D015342:DNA Probes; D004269:DNA, Bacterial; D004768:Enterotoxins; C019368:enterotoxin D, Staphylococcal; C026066:enterotoxin A, Staphylococcal; C031818:enterotoxin B, staphylococcal; C034959:enterotoxin C, staphylococcal