RESUMO
Background: Acinetobacter baumannii is an important nosocomial pathogen whose virulence factors have not been fully elucidated. Aim: To study the adherence and hemagglutinating capacity of several biotypes of Acinetobacter baumannii. Material and methods: Thirty nine strains of Acinetobacter baumannii isolated from hospitalized patients were studied. The adherence of these strains to small pieces of rat tracheal tissue was studied. Additionally, their ability to hemagglutinate human erythrocytes and the effect of D-mannose and D-galactose on the adherence and hemagglutinating capacity was assessed. Transmission electron microscopy of strains was performed looking for the presence of fimbriae. Results: All strains exhibited adherence to tissues. All strains had also D-mannose and D-galactose resistant hemagglutinating ability. Fimbriae were found in Acinetobacter baumannii and E coil cells. Conclusions: Adherence of Acinetobacter baumannii to rat tracheal tissue, apparently not related to the presence of fimbriae, may be a virulence mechanism of this bacterium