Congo red binding and salt aggregation as indicators of virulence in Shigella species
F Qadri, SA Hossain, I Ciznár, K Haider… - Journal of Clinical …, 1988 - Am Soc Microbiol
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. boydii, and S. sonnei. Using the salt
aggregation test (SAT) to determine cell surface hydrophobicity, we found the same order of …
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. boydii, and S. sonnei. Using the salt
aggregation test (SAT) to determine cell surface hydrophobicity, we found the same order of …
