Author
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Ravva, Subbarao |
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Submitted to: Meeting Abstract
Publication Type: Proceedings Publication Acceptance Date: 7/5/2006 Publication Date: 7/5/2006 Citation: Ravva, S.V. 2006. Nutrients and wastewater components influence the survival and growth of pathogenic escherichia coli o157:h7 in dairy lagoons [Abstract]. 2nd Federation of European Microbioilogy Societies (FEMS) Congress of European Microbiologists. Poster #P.ENV.109. Interpretive Summary: Technical Abstract: Survival of pathogenic strains of E. coli O157:H7 was monitored in laboratory microcosms of wastewater from dairy lagoons. E. coli declined rapidly in untreated wastewater, while they proliferated in steamed wastewater. The growth of E. coli O157:H7 strains was continuously monitored in 0.2 um filtered wastewater and in LB broth supplemented with incremental proportion of wastewater using Bioscreen incubation system. The growth of E. coli was inhibited incrementally by supplementing wastewater to LB broth and the organism failed to grow directly in wastewater. Acidic and basic organic extracts of wastewater inhibited growth in LB broth, while the neutral aqueous extracts enhanced growth. A strain of E. coli O157:H7 declined from 10 7 to 10 3 CFU/ml during a 10-day incubation in wastewater supplemented with or without additional 3-fold equivalents of acidic organic extract of wastewater. The organisms were maintained at almost the same initial level inside a 300 kd dialysis bag during a 28-day exposure to diffusible components of wastewater, while a 4 log decline was observed in 5 d when the organism was directly inoculated in wastewater. Although wastewater can potentially provide nutrients, competition from indigenous organisms and the components of wastewater can inhibit the growth and proliferation of introduced pathogens in dairy lagoons. |
