INVESTIGADORES
BUSTAMANTE Ana Victoria
artículos
Título:
Genetic Characterization of Non-O157 Verocytotoxigenic
Autor/es:
TOMÁS FRANCI; ANDREA MARIEL SANSO; ANA V. BUSTAMANTE; PAULA M.A. LUCCHESI; ALBERTO E. PARMA
Revista:
FOODBORNE PATHOGENS AND DISEASE
Editorial:
MARY ANN LIEBERT INC
Referencias:
Año: 2011 vol. 8 p. 1019 - 1023
ISSN:
1535-3141
Resumen:
Verocytotoxigenic Escherichia coli (VTEC) can produce serious human illness linked to the consumption of
contaminated food, mainly of bovine origin. There is growing concern about non-O157 VTEC serotypes, which
in some countries cause severe infections in a proportion similar to O157:H7 strains. As several epidemiological
studies indicated the important role of meat as the major vehicle in the transmission of this pathogen to human
consumers, our aim was to investigate the genetic diversity among non-O157:H7 VTEC isolated from raw beef
products. We performed a multiple-locus variable-number tandem repeat (VNTR) analysis (MLVA), and to our
knowledge, this is the first time that VTEC serotypes O8:H19, O112:H2, O113:NM, O171:NM, ONT:H7,
ONT:H19, and ONT:H21 were typed by this method. MLVA typing grouped the total number of strains from
this study (51) into 21 distinct genotypes, and 11 of them were unique. Several MLVA profiles were found in
different serotypes, O178:H19 being the most variable. The isolates could be principally discriminated by alleles
of three of seven loci studied (CVN001, CVN004, and CVN014), and on the other hand, CVN003 rendered null
alleles in all the isolates. As some VNTR markers might be serotype specific, it is possible that the implementation
of new VNTR loci will increase intraserotype discrimination.Escherichia coli (VTEC) can produce serious human illness linked to the consumption of
contaminated food, mainly of bovine origin. There is growing concern about non-O157 VTEC serotypes, which
in some countries cause severe infections in a proportion similar to O157:H7 strains. As several epidemiological
studies indicated the important role of meat as the major vehicle in the transmission of this pathogen to human
consumers, our aim was to investigate the genetic diversity among non-O157:H7 VTEC isolated from raw beef
products. We performed a multiple-locus variable-number tandem repeat (VNTR) analysis (MLVA), and to our
knowledge, this is the first time that VTEC serotypes O8:H19, O112:H2, O113:NM, O171:NM, ONT:H7,
ONT:H19, and ONT:H21 were typed by this method. MLVA typing grouped the total number of strains from
this study (51) into 21 distinct genotypes, and 11 of them were unique. Several MLVA profiles were found in
different serotypes, O178:H19 being the most variable. The isolates could be principally discriminated by alleles
of three of seven loci studied (CVN001, CVN004, and CVN014), and on the other hand, CVN003 rendered null
alleles in all the isolates. As some VNTR markers might be serotype specific, it is possible that the implementation
of new VNTR loci will increase intraserotype discrimination.