title: Occurrence of non-O157 shiga toxin-producing Escherichia coli in ready-to-eat food from supermarkets in Argentina.
abstract: Between June 2000 and December 2001, 500 food samples were collected from supermarkets and shops selling ready-to-eat food in Rosario, Argentina, and examined for Escherichia coli. Forty-nine E. coli isolates from food samples were further characterized for virulence genes by multiplex polymerase chain reaction (PCR) targeting the stx1, stx2, stx2e, eaeA, CNF1, CNF2, Einv, LTI, STI, and STII genes in four groups. Out of 49 E. coli isolates screened by multiplex PCR, only 10 possessed Shiga toxin genes, stx1 and stx2 genes and none possessed the other genes. The Shiga toxin positive E. coli strains (STEC) were isolated from soft, cottage cheeses, chicken with sauce and vegetables mayonase. These E. coli isolates were serogrouped and belonged to O18 (two strains), O8, O57w, O79, O44, and O128; three strains were untypeable. Pulsed-field gel electrophoresis (PFGE) with XbaI generated a unique profile for each, having 10-15 bands ranging from 50 to 500 kb, except that strain ARG 20 generated small bands and was partly degraded. These strains are potential foodborne pathogens and their presence in ready-to-eat food illustrates the need to keep a careful watch for the source of pathogens and then develop methods to control them.
authors.affiliation: Faculty of Biochemical and Pharmaceutical Sciences, National University of Rosario, Argentina.
authors.forename: Claudia
authors.initials: C
authors.lastname: Balagué
authors.forename: Ashraf A
authors.initials: AA
authors.lastname: Khan
authors.forename: Luisa
authors.initials: L
authors.lastname: Fernandez
authors.forename: Ana Lía
authors.initials: AL
authors.lastname: Redolfi
authors.forename: Virginia
authors.initials: V
authors.lastname: Aquili
authors.forename: Patricia
authors.initials: P
authors.lastname: Voltattorni
authors.forename: Claudio
authors.initials: C
authors.lastname: Hofer
authors.forename: Guillermo
authors.initials: G
authors.lastname: Ebner
authors.forename: Susana
authors.initials: S
authors.lastname: Dueñas
authors.forename: Carl E
authors.initials: CE
authors.lastname: Cerniglia
mesh_terms: D001118:Argentina; D003257:Consumer Product Safety; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D004926:Escherichia coli / Q000302:isolation & purification*; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D005798:Genes, Bacterial; D016133:Polymerase Chain Reaction / Q000379:methods