Open AccessProduction and Partial Purification of Heat-Stable Enterotoxin (A) Produced by Enterotoxigenic Escherichia coli
Author(s) -
Maha Fakhry Altaee,
Zaid K. Kamona,
Rajiha I. Al-Nuaimy
Publication year - 2010
Publication title -
the iraqi journal of veterinary medicine/al-maǧallaẗ al-ṭibbiyyaẗ al-bayṭariyyaẗ al-’irāqiyyaẗ
Language(s) - English
Resource type - Journals
eISSN - 2410-7409
pISSN - 1609-5693
DOI - 10.30539/iraqijvm.v34i1.668
Subject(s) - sephadex , heat stable enterotoxin , enterotoxin , enterotoxigenic escherichia coli , chromatography , toxin , chemistry , escherichia coli , column chromatography , ion exchange , microbiology and biotechnology , bovine serum albumin , ion chromatography , biology , biochemistry , ion , enzyme , gene , organic chemistry
A total of (25) stool samples were collected from children and adults (2- 4) years oldsuffering from diarrhea to isolate E. coli strains that produce heat-stable enterotoxin a (STa),and after performing microscopic examination, cultural characterization and biochemicalidentification only (11) isolates showed positive E. coli. STa activity was estimated by usingsuckling mouse assay (SMA) and from these (11) isolates only (5) showed STa activity andthe one with the highest STa activity was selected for large scale production of STa, whichwas followed by partial purification using ion-exchange chromatography (normal phase)using DEAE sephadex A-50 column. After purification and determination of proteinconcentration by using the standard curve of bovine serum albumin, the concentration oftoxin-protein was estimated as (1.08) mg/ml. The specific activity varied from (350) U/mgprotein at the first step of purification to (2366.6) U/mg protein at the final step, while thefinal purification of the toxin was about (6.76) fold and with a yield of (18.25) %.