Molecular typing of antimicrobial-resistant Shiga-toxin-producing Escherichia coli strains (STEC) in Brazil

• Autor(a) principal: Cergole-Novella, Maria Cecilia [UNIFESP]
• Data de Publicação: 2011
• Outros Autores: Pignatari, Antonio Carlos Campos [UNIFESP], Castanheira, Mariana [UNIFESP], Guth, Beatriz Ernestina Cabilio [UNIFESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://repositorio.unifesp.br/handle/11600/33385; http://dx.doi.org/10.1016/j.resmic.2010.09.022
• topic: Shiga-toxin-producing Escherichia coli; Resistance genes; Class 1 integron; Phylogenetic background

Antimicrobial resistance patterns and molecular characteristics were determined in thirty-two Shiga-toxin-producing Escherichia coli (STEC) strains previously identified in São Paulo State associated with human infections (n = 21) and in cattle feces (n = 11). the highest resistance rates were identified for tetracycline (100%), streptomycin (78%) and trimethoprim sulfamethoxazole (56%). Eleven STEC strains showed resistance to ampicillin and carried bla(TEM) that was confirmed as bla(TEM-1) in one representative isolate. the class 1 integrase gene (intI1) was detected in seven (22%) strains, and most of them belonged to the O111:H8 serotype. the class 1 integron was located on plasmids in five of the seven STEC strains, and conjugation assays confirmed the plasmid support of those resistant determinants. STEC strains were genetically classified into the B I group, and PFGE analysis showed that most of the strains in each serogroup were grouped into the same cluster (80-97% similarity). the presence of a class 1 integron and bla(TEM-1) genes is described for the first time among STEC isolates in Brazil and clearly represents a public health concern. (C) 2010 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.