Molecular characterization and antimicrobial resistance profiles of Salmonella Heidelberg isolates from poultry

In the last 10 years, Salmonella Heidelberg has been extensively isolated from poultry in several countries. In this context, molecular characterization is essential to understand whether the strains have entered the farms from a single or several sources. Thus, the aim of this study was to determine the genetic relationship and antimicrobial susceptibility of S. Heidelberg strains isolated between 2011 and 2012 from broiler farms belonging to three integrated poultry companies located in Argentina. The genetic relatedness of the S. Heidelberg isolates was determined by pulsed-field gel electrophoresis (PFGE), and resistance to 21 antimicrobials was determined by the disc diffusion method. The isolates were assigned to four PFGE patterns. Most of the strains showed 100% similarity and belonged to the same integrated poultry company. This PFGE pattern was also prevalent in S. Heidelberg strains isolated from humans in several provinces of Argentina, which suggests an epidemiological association between human and poultry strains. All the isolates were classified as multidrug-resistant (MDR), and no clear relationship was observed between PFGE and resistance patterns. S. Heidelberg strains may circulate among farms from the same integrated company due to common sources of contamination. To guarantee the safety of the poultry product for the consumers, holistic approaches including surveillance of Salmonella throughout the production chain together with control measures are crucial.Fil: Dominguez, Johana Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Patobiología Veterinaria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Patobiología Veterinaria; ArgentinaFil: Viñas, María Rosa. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán"; ArgentinaFil: Herrera, Mariana. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; ArgentinaFil: Moroni, Mirian. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán"; ArgentinaFil: Gutkind, Gabriel Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Mercado, Elsa Cristina. Investigación En Ciencias Veterinarias y Agronómicas; ArgentinaFil: Di Conza, José Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Chacana, Pablo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentina. Investigación En Ciencias Veterinarias y Agronómicas; Argentin