Empleo de la espectrometría de masas como herramienta para la determinación de tóxicos en alimentos: hacia la seguridad alimentaria

González, Roberto Romero; Moreno, José L.; Plaza‐Bolaños, Patricia; Vidal, José Luis Martı́nez

doi:10.1590/s1135-57272007000500004

Cited by 3 publications

References 44 publications

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Adesinas fimbriais em Escherichia coli enteropatogênica atípica: prevalência e proteômica.

Nara¹

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Atypical enteropathogenic Escherichia coli (aEPEC) have emerged as a significant cause of pediatric diarrhea worldwide. Due to the absence of BFP fimbriae (bundle-forming pili), aEPEC are unable to develop the 3 h-localized adhesion pattern observed in typical EPEC. Since some aEPEC show the adherence phenotype observed for other pathotypes of E. coli, the aim of this study was to investigate, in aEPEC, the presence of adhesin genes found in other pathogenic E. coli and to analyze, by comparative proteomic analyses, the protein extracts isolated from aEPEC BA320 (localized-like), Ec292/84 (aggregative) and 9100-83 (diffuse) and BA4013 (non-adherent). Initially, transmission electron microscopy demonstrated the presence of different filamentous structures anchored to the surface in the four EPEC isolates. PCR analyses of aEPEC revealed the presence of the genes fimA, fimH, papA, ecpA, ldaH, pilS, daaC, sfpA, lpfA O113 and polymorphic variants (lpfA1 and lpfA2), which are also present in other pathotypes of E. coli. On the other hand, proteomic analyses of aEPEC extracts obtained with an Omnimixer and precipitated with ammonium sulfate, using 2D gel electrophoresis and LC-MS/MS, identified several proteins involved in different functional processes of bacteria, including proteins involved in the mechanism of bacterial adhesion, namely: a histone-like nucleoid structuring protein (H-NS), an outer membrane protein (OmpX), universal stress proteins (Usp), L-fucose mutarotase (FucU) and galactose-binding transport protein (MglB) associated with the action of adhesins of E. coli fimbriae. The protein extract also revealed "hypothetical" proteins, particularly a putative filamentous protein found in aEPEC with the phenotypes of localized-like, diffuse and aggregative adherence. Therefore, we conclude that the genes encoding type 1 fimbriae and ECP fimbriae are highly prevalent in aEPEC isolates, and that the proteins identified in the proteome of four aEPEC strains, which are related to different bacterial functions, can operate as protein complexes, directly or indirectly involved in adhesion processes.

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Adesinas fimbriais em Escherichia coli enteropatogênica atípica: prevalência e proteômica.

Nara¹

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Métodos Cromatográficos Para La Determinación De Endosulfán en Alimentos

Ángeles-Hernández

Amaya-Chávez

Rivera

et al. 2018

Rev. Int. Contam. Ambie.

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Palabras clave: plaguicidas orgánicos persistentes, extracción y limpieza, metodología analítica RESUMEN Se revisaron las técnicas de extracción, limpieza y cuantificación de endosulfán por métodos cromatográficos en matrices alimentarias como productos lácteos, frutas y vegetales, así como pescados y mariscos, publicados en los últimos veinte años. Independientemente del tipo de matriz, su extracción se realiza principalmente con disolventes orgánicos como hexano, metanol, acetonitrilo y acetona. Para la limpieza, lo más comúnmente empleado fueron cartuchos de sílice, columnas de florisil, o C18. En cuanto a la cuantificación, el método más sensible resultó ser la cromatografía de gases acoplada a espectrofotometría de masas (CG-MS). Los alimentos en los que se reportó la presencia de α, β y/o sulfato de endosulfán fueron: productos lácteos y sus derivados con un intervalo de concentraciones de 23.99 a 52.2 ng/g; pescados y mariscos de 1.07 a 49.7 ng/g; y vegetales de 0.5 a 5460.0 ng/g. En leche materna se reportaron concentraciones de 0.4 a 10.7 ng/mL y en grasa hasta 277.39 ng/g. Keywords: persistent organic pesticides, extraction and cleaning, analytic methodology ABSTRACT Extraction and cleaning techniques plus chromatographic methods were reviewed for the quantification of endosulfan in food matrices such as dairy products, fruits and vegetables, fish and seafood, published in the last twenty years. Regardless of the type of matrix, the extraction of endosulfan is carried out mainly with organic solvents such as hexane, methanol, acetonitrile and acetone. For cleaning, the most common was the use silica cartridges, florisil columns, or C18. The most sensitive quantification method was gas chromatography coupled to mass spectrometry (GC-MS. Foods where it was reported the presence of α, β and/or endosulfan sulfate were dairy products and their derivatives in a range of 23.99 to 52.2 ng/g, in fish and shellfish from 1.07 to 49.7 ng/g, vegetables from 0.5 to 5460.0 ng/g. In breast milk were from 0.4 to 10.7 ng/mL and in fat until 277.39 ng/g. REVISIÓNRev. Int. Contam. Ambie. 34 (Especial sobre Contaminación y Toxicología por Plaguicidas (CTP) [81][82][83][84][85][86][87][88][89][90][91][92][93][94] 2018

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Determinación de residuos de antibióticos veterinarios en productos de origen animal mediante cromatografía líquida

et al. 2018

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Empleo de la espectrometría de masas como herramienta para la determinación de tóxicos en alimentos: hacia la seguridad alimentaria

Cited by 3 publications

References 44 publications

Adesinas fimbriais em Escherichia coli enteropatogênica atípica: prevalência e proteômica.

Adesinas fimbriais em Escherichia coli enteropatogênica atípica: prevalência e proteômica.

Métodos Cromatográficos Para La Determinación De Endosulfán en Alimentos

Determinación de residuos de antibióticos veterinarios en productos de origen animal mediante cromatografía líquida

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