Failure of the Congo red dye uptake test to discriminate between virulent and avirulent avian Escherichia coli.
نویسندگان
چکیده
Twenty avian Escherichia coli isolates from normal and diseased chickens were compared by use of three virulence tests. These tests included the uptake of Congo red dye, an embryo lethality test, and a quantitative microtiter complement resistance test. A direct correlation was seen between the results of the complement resistance test and the embryo lethality test. The results of the Congo red test did not correlate with the two other tests.
منابع مشابه
Congo red binding and salt aggregation as indicators of virulence in Shigella species.
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....
متن کاملIn vitro assessment of pathogenicity and virulence encoding gene profiles of avian pathogenic Escherichia coli strains associated with colibacillosis in chickens
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...
متن کاملEffect of normal intestinal flora of chickens on colonization by virulent colicin V-producing, avirulent, and mutant colicin V-producing avian Escherichia coli.
Colonization of the intestinal tracts of newly hatched chicks with Escherichia coli was attempted by swabbing test organisms onto the air-shell of 19-day-old embryos. Test organisms consisted of two virulent E. coli isolates, one avirulent isolate, and one laboratory-derived mutant of the avirulent isolate carrying a recombinant plasmid coding for Colicin V production. Chicks were cultured week...
متن کاملPrediction of chicken embryo lethality with the avian Escherichia coli traits complement resistance, colicin V production, and presence of the increased serum survival gene cluster (iss).
Differentiating between virulent and avirulent avian Escherichia coli isolates continues to be a problem for poultry diagnostic laboratories and the study of colibacillosis in poultry. The ability of a laboratory to conduct one simple test that correlates with virulence would simplify studies in these areas; however, previous studies have not enabled researchers to establish such a test. In thi...
متن کاملComparing Invasive and Non-Invasive of Isolated Shigella flexneri by Electron Microscopy of Cell Culture, SDS-PAGE and Congo Red Method
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...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Avian diseases
دوره 36 4 شماره
صفحات -
تاریخ انتشار 1992