RESUMEN
The O-polysaccharide of Salmonella Telaviv was obtained by mild acid degradation of the lipopolysaccharide and studied by chemical methods (sugar and methylation analyses, Smith degradation, de-O-acetylation) and NMR spectroscopy. The structure of the O-polysaccharide was established. The repeating units that are proximal to the lipopolysaccharide core region mostly have a digalactose side chain and lack glucose, whereas those at the other end of the chain mostly do bear glucose but are devoid of the disaccharide side chain. This is the first structure established for the O-polysaccharide of a Salmonella serogroup O:28 (formerly M) strain characterized by subfactors O28(1) and O28(2). Knowledge of this structure and the structure of the O-polysaccharide of Salmonella Dakar (O28(1), O28(3)) established earlier is crucial for determination of the exact structures associated with subfactors O28(1), O28(2), and O28(3) and elucidation of the genetic basis of the close relationship between Escherichia coli O71 and S. enterica O:28 O-antigens.
Asunto(s)
Antígenos O/química , Salmonella enterica/química , Acetilglucosamina/análogos & derivados , Acetilglucosamina/análisis , Secuencia de Carbohidratos , Datos de Secuencia Molecular , Resonancia Magnética Nuclear Biomolecular , Salmonella enterica/inmunologíaRESUMEN
The use of bacteriophages, instead of antibodies, in the ELISA-based detection of bacterial strains was tested. This procedure appeared to be efficient, and specific strains of Salmonella enterica and Escherichia coli could be detected. The sensitivity of the assay was about 10(5) bacterial cells/well (10(6)/ml), which is comparable with or outperforms other ELISA tests detecting intact bacterial cells without an enrichment step. The specificity of the assay depends on the kind of bacteriophage used. We conclude that the use of bacteriophages in the detection and identification of bacteria by an ELISA-based method can be an alternative to the use of specific antibodies. The advantages of the use of bacteriophages are their environmental abundance (and, thus, a possibility to isolate various phages with different specificities) and the availability of methods for obtaining large amounts of phage lysates, which are simple, rapid, cheap, and easy.
Asunto(s)
Técnicas Bacteriológicas/métodos , Infecciones por Escherichia coli/diagnóstico , Escherichia coli/aislamiento & purificación , Infecciones por Salmonella/diagnóstico , Fagos de Salmonella/crecimiento & desarrollo , Salmonella enterica/aislamiento & purificación , Ensayo de Inmunoadsorción Enzimática/métodos , Escherichia coli/virología , Humanos , Salmonella enterica/virología , Sensibilidad y EspecificidadAsunto(s)
Pruebas de Aglutinación/métodos , Anticuerpos Antibacterianos/aislamiento & purificación , Yema de Huevo/microbiología , Infecciones por Salmonella/diagnóstico , Salmonella enteritidis/inmunología , Animales , Pollos , Ensayo de Inmunoadsorción Enzimática , Femenino , Infecciones por Salmonella/inmunologíaRESUMEN
Lipopolysaccharide (LPS) of Salmonella haarlem was hydrolyzed and the products separated. The structure of the O-specific polysaccharide (OPS) was found from sugar and methylation analyses. Rhamnose, mannose, galactose and tyvelose were detected and their linkage modes were established. The structure was confirmed by 1H, homonuclear and heteronuclear correlations and 13C NMR spectra. Anomeric configurations were assigned by chromium trioxide oxidation and proton coupled 13C spectra. Sugar sequence was established from specific carbon shift data and nuclear Overhauser effect spectroscopy. The repeating unit structure of S. haarlem OPS as --> 3)-alpha-D-Galp-(1 --> 6)-[alpha-Tyvp-(1 --> 3)]-beta-D-Manp-(1 --> 4)-alpha-L-Rhap was estimated. No structural heterogeneity of the antigen was found.
Asunto(s)
Epítopos de Linfocito B/química , Antígenos O/química , Salmonella/química , Conformación de Carbohidratos , Secuencia de Carbohidratos , Epítopos de Linfocito B/inmunología , Datos de Secuencia Molecular , Antígenos O/inmunología , Salmonella/inmunologíaRESUMEN
Lipopolysaccharide of Salmonella haarlem was hydrolyzed and the products separated. Native O-polysaccharide antigen was oxidised with sodium periodate followed by reduction with sodium borohydride. Native and chemically modified antigens were the subject of immunochemical studies. Monoclonal antibodies against S. haarlem and polyclonal rabbit antisera against S. haarlem, S. typhi and S. anatum bacteria were produced. The serological relationship between the lipopolysaccharide of Salmonella bacteria belonging to the two different groups D2 and E1 was demonstrated using haemagglutination reactions, inhibition of haemagglutination and immunoblotting. Cross-reactions were observed in haemagglutination reactions and in immunoblotting between antisera to S. haarlem, S. typhi and S. anatum. Factors 3,9,46 were found in the S. haarlem strain and the sugar composition for the epitopes of each factor was determined.
Asunto(s)
Epítopos de Linfocito B/inmunología , Antígenos O/inmunología , Salmonella/inmunología , Animales , Secuencia de Carbohidratos , Epítopos de Linfocito B/química , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Antígenos O/química , ConejosRESUMEN
The occurrence of S. enteritidis phage types in Poland during the years 1981-1990 was examined. The strains were isolated from man, animals, and from food-stuffs. The majority of strains belongs to the phage types 7 and 1. The comparison with the phage-types isolated in 1970-1975 in Poland is done. The stability of the phage types in reported outbreaks is considered.