Molecular characterization of commensal Escherichia coli adapted to different compartments of the porcine gastrointestinal tract

The role of Escherichia coli as a pathogen has been the focus of considerable study, while much less is known about it as a commensal and how it adapts to and colonizes different environmental niches within the mammalian gut. In this study, we characterize Escherichia coli organisms (n=146) isolated from different regions of the intestinal tracts of eight pigs (dueodenum, ileum, colon, and feces). The isolates were typed using the method of random amplified polymorphic DNA (RAPD) and screened for the presence of bacteriocin genes and plasmid replicon types. Molecular analysis of variance using the RAPD data showed that E. coli isolates are nonrandomly distributed among different gut regions, and that gut region accounted for 25% (

Isolation and characterization of Salmonella enterica from Antarctic wildlife

In recent years, the human presence in Antarctica has increased and as a consequence, the possibility of microorganisms' introduction. The aims of this work were to determine the presence of Salmonella enterica in Antarctic seabirds and sea mammals, to characterize the isolates identified, and to determine the genetic relation of Antarctic S. enterica isolates among them and compare with isolates of human, animal, and food sources recovered in Argentina. During the summer 2000 and 2002 in Potter Peninsula, and during the summer 2001 and 2003 in Hope Bay, a total of 1,739 fecal samples from Antarctic animals were collected and analyzed. In summer 2000, S. Newport and S. Enteritidis were isolated from 8.9% of southern giant petrels (Macronectes giganteus). In summer 2003, S. Enteritidis was isolated from 1.5% of Adelie penguins (Pygoscelis adeliae), from 5.5% of skuas (Stercorarius sp.), from 5.4% of kelp gulls (Larus dominicanus), and from 5.6% of Weddell seals (Leptonychotes weddelli). All the isolates belonging to the same serovar showed indistinguishable genomic profiles by Pulse-Field Gel Electrophoresis (PFGE) with XbaI and BlnI restriction enzymes and by Random Amplified Polymorphic DNA (RAPD-PCR). In addition, these Antarctic strains were different from S. enterica isolates from different sources identified in Argentina during the same or close time periods.Fil: Vigo, Germán Blás. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Microbiología. Cátedra de Microbiología; ArgentinaFil: Leotta, Gerardo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Caffer, María Inés. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; Argentina. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; ArgentinaFil: Salve, Angela. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; Argentina. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; ArgentinaFil: Binsztein, Norma. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; Argentina. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; ArgentinaFil: Pichel, Mariana. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Instituto Nacional de Enfermedades Infecciosas; Argentina. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentin