UV inactivation, liquid-holding recovery, and photoreactivation of Escherichia coli O157 and other pathogenic Escherichia coli strains in water.

摘要: Drinking water, water used in food production and for irrigation, fish farming, waste surface recreational have been recently recognized as a vector the transmission of pathogenic Escherichia coli, especially serotype O157:H7. We investigated UV (253.7 nm) inactivation behavior capability dark repair (liquid-holding recovery) photoreactivation seven (including three enterohemorrhagic E. coli) strains one nonpathogenic strain coli (ATCC 11229) with respect to use light disinfection purposes. Because most bacteria yeast are known be able damage their nucleic acids, mechanisms considered ensure safe disinfection. found wide divergence susceptibility within tested. A 6-log reduction that fulfills requirement was reached very susceptible O157:H7 (CCUG 29199) at fluence 12 J/m2, whereas resistant strain, O25:K98:NM, about 125 J/m2 needed. Except (O50:H7) liquid-holding recovery did not play an important role after irradiation. By contrast, all strains, particularly O78:K80:H12, 29193), demonstrated photorepair ability. For these up 300 is required. The results reveal minimum 400 demanded Austrian standard sufficient inactivate coli. 160 (recommendation Norway) or 250 Switzerland) cannot regarded respect.