Microorganisms produce functional amyloids that can be examined and manipulated in vivo and in vitro. Escherichia coli assemble extracellular adhesive amyloid fibers termed curli that mediate adhesion and promote biofilm formation. We have characterized the dye binding properties of the hallmark amyloid dye, Congo red, with curliated E. coli and with isolated curli fibers. Congo red binds to cu...

Congo red binding by virulent A-layer-containing (A+) and avirulent A-layer-deficient (A-) strains of Aeromonas salmonicida was examined. Congo red binding to A+ cells was enhanced by salt and thus hydrophobically driven, but at low Congo red concentrations binding was salt independent. Congo red was bound by A+ cells by a kinetically distinct mechanism (Kd, 0.25 microM) which was absent in A- ...

Six current histological methods for demonstrating amyloid (crystal violet, thioflavine-T fluorescence, Congo-red staining and fluorescence, Sirius-red staining, and Congo- or Sirius-red birefringence) were applied in 25 cases of amyloidosis of various types and 47 pseudo-amyloid lesions. The results were compared and were correlated with those of ancillary histochemical tests and clinico-patho...

OUCHI, E., MUTRA, K. and YAMAGATA, S. Reevaluation of Congo Red Test as Reticuloendothelial System Function Test Using Tritiated Congo Red Autoradio graphy. Tohoku J. exp. Med., 1973, 109 (3), 251-259 Tritiated Congo red was prepared by the gas exposure method. Analytical results obtained by thin layer chromatography and spectrophotometry indicated that the radioactive Congo red thus prepared h...

Congo red absorption is generally considered a contraindication of Rhizobium. However, R. leguminosarum takes up the dye on yeast extract-mannitol agar. The uptake of congo red varies among strains of R. leguminosarum, as shown elsewhere with strains of R. trifolii and R. meliloti. Congo red absorption does not distinguish rhizobia from other bacteria, but may be useful as a strain marker.

cadmium oxide rhombus-shaped nanostructure was synthesized using hydrothermal process followed by heating treatment. clearly, x-ray diffraction pattern demonstrated the formation of cdo crystalline phase. scanning electron microscopy (sem) showed that the obtained rhombus-like structure is composed of nanoparticles with the average size of 29 nm. in addition, we evaluated adsorption of organic ...

shigellosis is an acute gastroenteritis caused by shigella species. the purpose of this study was to determine plasmid profile, antibiotic resistance and phenotypic virulent by congo red between s. flexneri strains. the isolated bacteria were identified by standard bacterial and biochemical methods. plasmids were isolated by alkaline lysis method. antibiotic susceptibility test was performed ac...

The aim of this study was to compare invasive and non-invasive strains of Shigella flexneri isolated from Tehran by a 120 kDa protein band by SDS-PAGE, electron microscopy of cell culture and Congo red dye methods. Methods: S. flexneri strains were isolated by standard bacterial methods from fecal specimens of children attending to the 3 children’s hospitals. Phenotype analysis for screening v...

Cellulolytic fungi can easily be screened within 2 d for the production of cellulolytic enzymes by staining with Congo red, or by measuring the amount of reducing sugar (glucose) produced with the dinitrosalicyclic acid reagent method. Endoglucanase activity is visible in carboxymethyl cellulose agar plates after staining with Congo red, and fixing with HCI or NaOH. This method is essentially b...

Since the introduction of the intravenous Congo red test by Bennhold (1923), a number of writers have recorded observations on the intracutaneous injection of Congo red dye. Philpott and Freshman (1936) and Nomland (1936) observed intense and prolonged staining of cutaneous amyloid deposits in patients following the local injection of Congo red solution. Laine, Holopainen, and Makinen (1956) no...