title: Presence of enterotoxigenic Staphylococcus aureus in artisan fruit salads in the city of San Luis, Argentina.
abstract: An increase in the consumption of fruit juices and minimally processed fruits salads has been observed in recent years all over the world. In this work, the microbiological quality of artisan fruit salads was analysed. Faecal coliforms, Salmonella spp, Shigella spp, Yersinia enterocolitica and Escherichia coli O157:H7 were not detected; nevertheless, eleven strains of Staphylococcus aureus were isolated. By multiplex PCR, all isolates showed positive results for S. aureus 16S rRNA gene and 63.6% of them were positive for sea gene. Furthermore, PCR sea positive strains were able to produce the corresponding enterotoxin. Finally, the inactivation of these strains in fruit salads by nisin, lysozyme and EDTA, was studied. EDTA produced a total S. aureus growth inhibition after 60 h of incubation at a concentration of 250 mg/L. The presence of S. aureus might indicate inadequate hygiene conditions during salad elaboration; however, the enterotoxigenicity of the strains isolated in this study, highlights the risk of consumers' intoxication. EDTA could be used to inhibit the growth of S. aureus in artisan fruit salads and extend the shelf life of these products.
authors.affiliation: Microbiología General, Universidad Nacional de San Luis, San Luis, Argentina.
authors.forename: Cecilia S M Lucero
authors.initials: CS
authors.lastname: Estrada
authors.affiliation: Bacteriología y Virología, Área Microbiología, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina.
authors.forename: Lucia E
authors.initials: LE
authors.lastname: Alcaráz
authors.affiliation: Bacteriología y Virología, Área Microbiología, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina.
authors.forename: Sara E
authors.initials: SE
authors.lastname: Satorres
authors.affiliation: Servicio Fisiopatogenia, Departamento de Bacteriología, INEI-ANLIS "Dr. Carlos G. Malbrán", Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Manfredi
authors.affiliation: Microbiología General, Universidad Nacional de San Luis, San Luis, Argentina.
authors.forename: Lidia Del C
authors.initials: Ldel C
authors.lastname: Velázquez
mesh_terms: D001118:Argentina; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D004768:Enterotoxins / Q000235:genetics*; D005638:Fruit / Q000382:microbiology*; D060885:Multiplex Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013211:Staphylococcus aureus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D004768:Enterotoxins; D012336:RNA, Ribosomal, 16S
keywords: Staphylococcus aureus; antimicrobial compounds; enterotoxigenic strains; fruit salads; multiplex PCR