Article
A preliminary investigation on the chemical composition of the cell surface of five enteropathogenic Escherichia coli serotypes
Registro en:
MANGIA, Adriana Hamond Regua et al. A preliminary investigation on the chemical composition of the cell surface of five enteropathogenic Escherichia coli serotypes. Memórias do Instituto Oswaldo Cruz, v.94, n.4, p.513-518,1999
0074-0276
10.1590/S0074-02761999000400016
1678-8060
Autor
Mangia, Adriana Hamond Regua
Bergter, Eliana Barreto
Teixeira, Lúcia Martins
Costa e Silva Filho, Fernando
Resumen
The cell surfaces of five enteropathogenic Escherichia coli serotypes (O111:H2; O111:H12; O125:H9; O119:H6; O26:H11) were assayed by chemical methods, lectin agglutination tests and spectroscopy associated to transmission electron microscopy. Results of lectin agglutination assays showed that all strains reacted with mannosebinding lectins. Strains belonging to serotype O125:H9 also agglutinated with lectins which recognize galactose and Nacetylgalactosamine residues. The bacterial cells were treated with 0.01M phosphate buffered saline (pH 7.0) at 100oC for 2 hr and the extracts were submitted to precipitation and fractionated by Cetavlon. Phosphate, total sugar and protein contents were determined. Gas liquid chomatography-mass spectrometry analysis of alditol acetates showed the presence of galactose, mannose, fucose, glucose and traces of ribose. Spectroscopic analysis of intact cells showed the presence of a capsule-like structure which was not totally preserved after extraction. Some cells were still surrounded by an amorphous capsular-like material after polysaccharide extraction.