Effect of stress on production of heat labile enterotoxin by Escherichia coli

Mallya, S and Bhat, GK and Hegde, A (2009) Effect of stress on production of heat labile enterotoxin by Escherichia coli. Indian Journal of Medical Microbiology, 27 (4). pp. 325-328.

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Enterotoxigenic Escherichia coli (ETEC) is an important pathogen responsible for secretory diarrhoea. The production of heat labile enterotoxin (LT), by ETEC, is largely responsible for the pathogenesis of diarrhoea. In the present study we investigated the effect of stress factors such as temperature, pH, osmotic stress and nutritional limitation on the production of LT by ETEC using in-house GMI-ELISA. Four strains of E. coli consisting, one standard strain MTCC 723 and three clinical isolates were used in the study. Maximum amount of LT (OD 3.285) was produced at 37 0 C followed by 40 0 C (OD 3.305). Growth of E. coli in medium with pH 8.6 resulted in maximum amount of LT production (OD 3.489). LT was not detectable when bacteria were grown in medium with pH ≤7.2 and ≥ 9.2. Sodium chloride concentration of 0.2 M stimulated maximum amount of LT production. Maximum amount of LT was produced when the bacteria were grown in medium containing 2.5g/l of glucose. All the stress factors had a significant effect on the LT production by E. coli , though quantitative differences in the various strains were observed.

Item Type: Article
Uncontrolled Keywords: Enterotoxigenic Escherichia coli, Heat labile enterotoxin, Stress, GM1-ELISA
Subjects: Medicine > KMC Mangalore > Microbiology
Depositing User: KMCMLR User
Date Deposited: 01 Mar 2012 09:44
Last Modified: 01 Mar 2012 09:44
URI: http://eprints.manipal.edu/id/eprint/3413

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