Integrones y cassettes genéticos de resistencia a antimicrobianos en cepas de Shigella flexneri

• Jeannette Muñoz A ^[1] ; Helia Bello T ^[1] ; Mariana Domínguez Y ^[1] ; Sergio Mella M ^[1] ; Raúl Zemelman Z ^[2] ; Gerardo González R ^[1]
  1. [1] Universidad de Concepción

     Universidad de Concepción

     Comuna de Concepción, Chile

     
  2. [2] Universidad San Sebastián

     Universidad San Sebastián

     Comuna de Concepción, Chile

     
• Localización: Revista Médica de Chile, ISSN-e 0034-9887, Vol. 131, Nº. 7, 2003, págs. 727-733
• Idioma: español
• Títulos paralelos:
  • Integrons and antimicrobial resistance gene cassettes in Shigella flexneri strains
• Enlaces
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• Resumen

  • Background: The resistance of Shigella flexneri to antimicrobial agents can be associated to the presence of integrons that may contain and express antimicrobial resistance gene cassettes. Aim: To study antimicrobial resistance and the presence of integrons and antimicrobial gene cassettes in Shigella flexneri strains. Material and methods: In vitro susceptibility to 27 antimicrobials was studied in twenty four Shigella flexneri strains isolated from stools. The presence of integrons class 1, 2 and 3 and antimicrobial resistance gene cassettes was investigated by polymerase chain reaction (PCR) using specific primers for each gene. Results: Most strains were resistant to one of the following antimicrobials: ampicillin, sulphonamide, trimethoprim, tetracycline, streptomycin, sulfamethoxazole-trimethoprim or chloramphenicol. Twenty nine percent were simultaneously resistant to all these antimicrobials. Integrons class 1 and 2 were found in 19 strains (79%). Class 3 integrons were not found. Gene cassettes dfrA1 and ant(3")I were associated to integrons class 2 in most strains (15/20, 75%). Genes cat, tetB and blarTEM were detected in 18/24 (75%), 7/24 (29%) and 4/24 (17%) of the strains, respectively and were not associated to any of the studied integrons. Genes that codify enzymes AAC(6')Ib and APH(3')VI were not detected in any strain. Conclusions: The high frequency of integrons found in the studied strains, could partly explain the increasing antimicrobial resistance of Shigella flexneri strains, isolated in Chile (Rev Méd Chile 2003; 131: 727-33)