To evaluate which dye is effective in a plate assay for detecting extracellular cellulase activity produced by fungi, four chromogenic dyes including remazol brilliant blue, phenol red, congo red, and tryphan blue, were compared using chromagenic media. For the comparison, 19 fungal species belonging to three phyla, ascomycota, basidiomycota, and zygomycota were inoculated onto yeast nitrogen-b...

Smooth strains of Shigella dysenteriae type 1, Shigella flexneri, Shigella boydii, and Shigella sonnei which form pigmented colonies (Pcr+) on Congo red agar were virulent in the Sereny test. Smooth variants unable to bind Congo red (Pcr-) were avirulent. Measurements of dye uptake from solution showed that S. dysenteriae type 1 bound the most dye, followed in order of uptake by S. flexneri, S....

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...

UNLABELLED Numerous bacteria, including Yersinia pestis, express the poly-N-acetylglucosamine (PNAG) surface carbohydrate, a major component of biofilms often associated with a specific appearance of colonies on Congo red agar. Biofilm formation and PNAG synthesis by Y. pestis have been reported to be maximal at 21 to 28°C or "flea temperatures," facilitating the regurgitation of Y. pestis into...

An alternative method for detecting the production of slime by coagulase negative staphylococci was compared with the routinely used Christensen method on 124 isolates ofcoagulase negative staphylococci from carriage sites, blood cultures, and infected peritoneal dialysis fluids. The alternative method requires the use ofa specially prepared solid medium-brain heart infusion broth, supplemented...

Background: Avian pathogenic Escherichia coli (APEC) strains have been associated with various disease conditions in avian species due to virulence attributes associated with the organism. Aims: This study was carried out to determine the in vitro pathogenic characteristics and virulence encoding genes found in E. coli strains associated with colibacillosis in chickens. Methods: Fifty-two stock...

In this study we investigated the phenotypic slime production of Vibrio alginolyticus and Vibrio parahaemolyticus strains, food-borne pathogens, using a Congo red agar plate assay. Furthermore, we studied their ability to adhere to abiotic surfaces and Vero cells line. Our results showed that only V. alginolyticus ATCC 17749 was a slime-producer developing almost black colonies on Congo red aga...

An alternative method for detecting the production of slime by coagulase negative staphylococci was compared with the routinely used Christensen method on 124 isolates of coagulase negative staphylococci from carriage sites, blood cultures, and infected peritoneal dialysis fluids. The alternative method requires the use of a specially prepared solid medium--brain heart infusion broth, supplemen...

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 vi...