title: Investigation of a Staphylococcal Food Poisoning Outbreak from a Chantilly Cream Dessert, in Umbria (Italy).
abstract: On August 28, 2015, a staphylococcal food poisoning outbreak occurred in Umbria, Italy, affecting 24 of the 42 customers who had dinner at a local restaurant. About 3 h after ingesting a variety of foods, the customers manifested gastrointestinal symptoms. Within 24 h of notification from the hospital emergency department, Sanitary Inspectors of the local Public Health Unit performed an epidemiological investigation. A retrospective cohort study was conducted among the customers. Food and environmental samples were collected. Due to the rapid onset of symptoms (vomiting, diarrhea), the food samples were analyzed for the presence of toxigenic bacteria and their toxins; nasopharyngeal swabs were collected from the waiters and cooks. Among the food tested, high levels of coagulase-positive staphylococci (CPS) (3.4 × 108CFU/g) and staphylococcal enterotoxins (2.12 ng SEA/g) were only detected in the Chantilly cream dessert. CPS were also detected on the surface of a kitchen table (10 CFU/swab), and five food handlers were positive for Staphylococcus aureus. In total, five enterotoxigenic S. aureus isolates were recovered from three food handlers, a kitchen surface, and the Chantilly cream dessert. These isolates were further characterized by biotyping, pulsed-field gel electrophoresis, and multiplex polymerase chain reaction assays for the detection of eleven enterotoxin encoding genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sep, and ser) and three genes involved in antibiotic resistance (mecA, mecC, and mupA). Three sea-positive strains, isolated from the dessert, environment, and one of the cooks, had the same pulsed-field gel electrophoresis profile and belonged to the human biotype, suggesting that the contamination causing the outbreak most likely originated from a food handler. Moreover, improper storage of the dessert, at room temperature for about 5 h, permitted microbial growth and SEA production. This study underlines the importance of both laboratory evidence and epidemiological data for outbreak investigation.
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale Umbria e Marche , Perugia, Italy .
authors.forename: Laura
authors.initials: L
authors.lastname: Ercoli
authors.affiliation: 2 National Reference Laboratory Stafilococchi coagulasi positivi-Istituto Zooprofilattico Sperimentale del Piemonte , Liguria e Valle d'Aosta, Torino, Italy .
authors.forename: Silvia
authors.initials: S
authors.lastname: Gallina
authors.affiliation: 3 Laboratory for Food Safety, Anses, Université Paris-Est , Maisons-Alfort, France .
authors.forename: Yacine
authors.initials: Y
authors.lastname: Nia
authors.affiliation: 3 Laboratory for Food Safety, Anses, Université Paris-Est , Maisons-Alfort, France .
authors.forename: Frédéric
authors.initials: F
authors.lastname: Auvray
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale Umbria e Marche , Perugia, Italy .
authors.forename: Sara
authors.initials: S
authors.lastname: Primavilla
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale Umbria e Marche , Perugia, Italy .
authors.forename: Fabrizia
authors.initials: F
authors.lastname: Guidi
authors.affiliation: 4 Dipartimento Prevenzione Servizio Igiene Alimenti e Nutrizione, USL Umbria 1, Piazza Giovanni XXIII, Citta' di Castello, Italy .
authors.forename: Benedetta
authors.initials: B
authors.lastname: Pierucci
authors.affiliation: 4 Dipartimento Prevenzione Servizio Igiene Alimenti e Nutrizione, USL Umbria 1, Piazza Giovanni XXIII, Citta' di Castello, Italy .
authors.forename: Catia
authors.initials: C
authors.lastname: Graziotti
authors.affiliation: 2 National Reference Laboratory Stafilococchi coagulasi positivi-Istituto Zooprofilattico Sperimentale del Piemonte , Liguria e Valle d'Aosta, Torino, Italy .
authors.forename: Lucia
authors.initials: L
authors.lastname: Decastelli
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale Umbria e Marche , Perugia, Italy .
authors.forename: Stefania
authors.initials: S
authors.lastname: Scuota
mesh_terms: D004269:DNA, Bacterial / Q000302:isolation & purification; D003611:Dairy Products / Q000382:microbiology*; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D004768:Enterotoxins / Q000302:isolation & purification; D005506:Food Contamination; D005511:Food Handling; D005516:Food Microbiology; D064351:Genes, Microbial; D006291:Health Policy; D006801:Humans; D007558:Italy / Q000453:epidemiology; D060885:Multiplex Polymerase Chain Reaction; D012147:Restaurants; D012189:Retrospective Studies; D013202:Staphylococcal Food Poisoning / Q000453:epidemiology*; D013211:Staphylococcus aureus / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D004768:Enterotoxins
keywords: food microbiology; foodborne outbreaks; outbreak investigation; pathogen identification and typing methods