title: Foodborne Salmonellosis in Italy: Characterization of Salmonella enterica Serovar Typhimurium and Monophasic Variant 4,[5],12:i- Isolated from Salami and Human Patients.
abstract: Salmonella enterica serovar Typhimurium (STm) and its monophasic variant 4,[5],12:i:- (VMSTm) have been responsible for an increased number of foodborne infections in humans in Europe in recent years. The aim of this study was to investigate the origin of three foodborne salmonellosis outbreaks that occurred in Pavia Province (Lombardy region, northern Italy) in 2010. Phenotypic and genetic characteristics of the STm and VMSTm isolates from patients and from food that were recovered in the framework of the three outbreaks were evaluated through serotyping, phage typing, antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE), and multiple-locus variable-number tandem repeat analysis (MLVA). Salami from three artisan producers, which had all purchased meat from the same slaughterhouse, was the food source of infection in outbreak I. STm isolates were recovered from salami and patients with symptoms of gastroenteritis. These isolates had the same PFGE type and the same rare MLVA profile (3-18-9-NA-211). The same molecular profiles were found in an STm isolate from a salami, which likely was the source of another family outbreak (II). A VMSTm strain with common phenotypic and molecular profiles was isolated from three hospitalized patients and identified as the cause of another putative outbreak (III). During the following 3 years (2011 through 2013), 360 salami produced in Pavia Province were monitored for the presence of S. enterica . In 2011, no STm and VMSTm isolates were recovered from 159 salami tested. During 2012 and 2013, 13.9% of 201 tested salami harbored S. enterica , and half of the isolates were VMSTm, mainly in salami from those artisan producers involved in the previous outbreaks. These isolates were genetically variable, especially in terms of MLVA profiles. The data collected suggest that from 2012, VMSTm has replaced STm in the environments of the salami producers monitored in this study, and these data confirm the dominance of this emergent serovar along the pork supply chain.
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna "Bruno Ubertini," Pavia Unit, Strada Campeggi 59/61, 27100 Pavia, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Andreoli
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna "Bruno Ubertini," Pavia Unit, Strada Campeggi 59/61, 27100 Pavia, Italy.|2 Dipartimento di Scienze del Farmaco & Drug and Food Biotechnology Center (DFB), Università degli Studi del Piemonte Orientale "Amedeo Avogadro," Largo Donegani 2, 28100 Novara, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Merla
authors.affiliation: 3 Department of Microbiology and Virology, Fondazione IRCCS Policlinico San Matteo, Via Taramelli 5, 27100 Pavia, Italy.|4 Department of Clinical Biochemistry, Guglielmo da Saliceto Hospital, Via G. Taverna 49, 29121 Piacenza, Italy.
authors.forename: Claudia Dalla
authors.initials: CD
authors.lastname: Valle
authors.affiliation: 5 Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna "Bruno Ubertini," Modena Unit, Via Diena 16, 41100 Modena, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Corpus
authors.affiliation: 6 Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna "Bruno Ubertini," Parma Unit, Via dei Mercati 13/A, 43100 Parma, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Morganti
authors.affiliation: 7 Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna "Bruno Ubertini," Via Bianchi 9, 25124 Brescia, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: D'incau
authors.affiliation: 8 Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna "Bruno Ubertini," Milano Unit, Via Celoria 12, 20133 Milano, Italy; and.
authors.forename: Silvia
authors.initials: S
authors.lastname: Colmegna
authors.affiliation: 3 Department of Microbiology and Virology, Fondazione IRCCS Policlinico San Matteo, Via Taramelli 5, 27100 Pavia, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Marone
authors.affiliation: 1 Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna "Bruno Ubertini," Pavia Unit, Strada Campeggi 59/61, 27100 Pavia, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Fabbi
authors.affiliation: 9 World Organization for Animal Health (OIE), National Reference Laboratory for Salmonella, Centro di Referenza Nazionale e Laboratorio OIE per le Salmonellosi, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020 Legnaro, Padova, Italy.
authors.forename: Lisa
authors.initials: L
authors.lastname: Barco
authors.affiliation: 5 Istituto Zooprofilattico Sperimentale della Lombardia e dell' Emilia Romagna "Bruno Ubertini," Modena Unit, Via Diena 16, 41100 Modena, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Carra
mesh_terms: D000818:Animals; D016521:Electrophoresis, Gel, Pulsed-Field; D005060:Europe; D006801:Humans; D007558:Italy / Q000453:epidemiology; D000069466:Red Meat; D012480:Salmonella Infections / Q000453:epidemiology; D019779:Salmonella enterica / Q000302:isolation & purification; D012486:Salmonella typhimurium / Q000302:isolation & purification*; D065288:Serogroup; D013552:Swine
keywords: Foodborne outbreak; Monophasic variant 4,[5],12:i−; Salami; Salmonella Typhimurium