title: Characterization of Shiga toxin-producing Escherichia coli isolated from ground beef collected in different socioeconomic strata markets in Buenos Aires, Argentina.
abstract: Consumption of raw/undercooked ground beef is the most common route of transmission of Shiga toxin-producing E. coli (STEC). The aim of the study was to determine the STEC contamination level of the ground beef samples collected in 36 markets of different socioeconomic strata in Buenos Aires, Argentina, and the characterization of the isolated strains. Ninety-one out of 252 (36.1%) samples were stx+. Fifty-seven STEC strains were recovered. Eleven STEC strains belonged to O157 serogroup, and 46 to non-O157 serogroups. Virulence markers of the 57 STEC were stx1, 5.3% (3/57); stx2, 86.0% (49/57); stx1/stx2, 8.8% (5/57); ehxA, 61.4% (35/57); eae, 26.3% (15/57); saa, 24.6% (14/57). Shiga toxin subtypes were stx2, 31.5% (17/54); stx2c-vhb, 24.1% (13/54); stx2c-vha, 20.4% (11/54); stx2/stx2c-vha, 14.8% (8/54); stx2/stx2c-vhb, 5.6% (3/54); stx2c-vha/vhb, 3.7% (2/54). Serotypes O178:H19 and O157:H7 were prevalent. Contamination rate of STEC in all strata was high, and the highest O157 contamination was observed at low strata at several sampling rounds. Persistence of STEC was not detected. Sixteen strains (28.1%) were resistant to ampicillin, streptomycin, amikacin, or tetracycline. The STEC contamination level of ground beef could vary according to the sociocultural characteristics of the population.
authors.affiliation: Microbiología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarín 280, CP1427CWO Buenos Aires, Argentina.
authors.forename: Patricia
authors.initials: P
authors.lastname: Llorente
authors.affiliation: Microbiología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarín 280, CP1427CWO Buenos Aires, Argentina.
authors.forename: Laura
authors.initials: L
authors.lastname: Barnech
authors.affiliation: Instituto Adolfo Lutz, 01246-000 Sao Paulo, SP, Brazil.
authors.forename: Kinue
authors.initials: K
authors.lastname: Irino
authors.affiliation: Microbiología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarín 280, CP1427CWO Buenos Aires, Argentina.
authors.forename: María Valeria
authors.initials: MV
authors.lastname: Rumi
authors.affiliation: Microbiología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarín 280, CP1427CWO Buenos Aires, Argentina.
authors.forename: Adriana
authors.identifier: 0000-0003-4075-5603
authors.initials: A
authors.lastname: Bentancor
mesh_terms: D000818:Animals; D001118:Argentina; D015415:Biomarkers / Q000378:metabolism; D002417:Cattle; D004352:Drug Resistance, Microbial; D008460:Meat / Q000191:economics / Q000382:microbiology*; D054323:Shiga-Toxigenic Escherichia coli / Q000302:isolation & purification* / Q000472:pathogenicity; D012959:Socioeconomic Factors; D014774:Virulence
chemical_list: D015415:Biomarkers