title: Prevalence and characteristics of verotoxigenic Escherichia coli strains isolated from pigs and pork products in Umbria and Marche regions of Italy.
abstract: In total 1095 samples from 675 pork products, 210 swine colon contents, and 210 swine carcass sponge swabs were collected in Umbria and Marche regions of Italy and examined for the presence of Shiga toxin-producing Escherichia coli (STEC), also known as Verotoxin-producing E. coli (VTEC). After an enrichment step, each sample was analysed by real-time PCR to detect the stx1, stx2, and eae genes. stx-Positive samples were further tested for the "top five" serogroup markers (O157, O26, O103, O111, O145) and cultured onto selective media. The isolates were assigned to stx subtypes and tested for the presence of aaiC and aggR genes. Out of 420 swine samples, 38.6% faecal samples and 13.8% carcass sponge swabs were stx-positive. In total, 33 E. coli STEC isolates were obtained from 30 samples (4 carcasses and 26 colon contents) indicating a culture-positive rate of 7.1%. A higher culture-positive rate was observed in faecal samples (12.4%) than in carcass sponge swabs (1.9%). Out of 675 pork samples, 19 (2.8%) were stx-positive. No STEC strains were isolated from stx-positive pork products. We concluded that STEC isolation from foodstuffs remains difficult, despite the application of ISO/TS 13136:2012. Furthermore, in accordance with the results of studies conducted in other countries, we observed that most of swine STEC strains carried stx2e gene and lacked of virulence genes, such as eae, aaiC and aggR, indicative of potential pathogenic characteristics for humans. Although the majority of STEC isolates did not express virulence factors correlating with severe human diseases, the association between swine STEC strains and human illness requires further investigations.
authors.affiliation: Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, via G. Salvemini n.1, 06126 Perugia, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Ercoli
authors.affiliation: Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, via G. Salvemini n.1, 06126 Perugia, Italy.
authors.forename: Silvana
authors.initials: S
authors.lastname: Farneti
authors.affiliation: Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, via G. Salvemini n.1, 06126 Perugia, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Zicavo
authors.affiliation: Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, via G. Salvemini n.1, 06126 Perugia, Italy.
authors.forename: Guerriero
authors.initials: G
authors.lastname: Mencaroni
authors.affiliation: Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, via G. Salvemini n.1, 06126 Perugia, Italy.
authors.forename: Giuliana
authors.initials: G
authors.lastname: Blasi
authors.affiliation: Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, via G. Salvemini n.1, 06126 Perugia, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Striano
authors.affiliation: Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, via G. Salvemini n.1, 06126 Perugia, Italy. Electronic address: s.scuota@izsum.it.
authors.forename: Stefania
authors.initials: S
authors.lastname: Scuota
mesh_terms: D018829:Adhesins, Bacterial / Q000032:analysis / Q000235:genetics; D000818:Animals; D003106:Colon / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000032:analysis / Q000235:genetics; D005243:Feces / Q000382:microbiology; D005516:Food Microbiology; D006801:Humans; D007558:Italy; D008461:Meat Products / Q000382:microbiology*; D015995:Prevalence; D060888:Real-Time Polymerase Chain Reaction; D000069466:Red Meat / Q000382:microbiology*; D022622:Shiga Toxin 1 / Q000032:analysis* / Q000235:genetics; D022641:Shiga Toxin 2 / Q000032:analysis* / Q000235:genetics; D054323:Shiga-Toxigenic Escherichia coli / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D013552:Swine / Q000382:microbiology*; D015534:Trans-Activators / Q000032:analysis / Q000235:genetics; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000032:analysis / Q000235:genetics
chemical_list: D018829:Adhesins, Bacterial; C088603:AggR protein, E coli; D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D015534:Trans-Activators; D037521:Virulence Factors; C073819:eaeA protein, E coli
keywords: Escherichia coli; PCR; Pig; STEC; Stx2e