Control of Escherichia coli O157:H7 with sodium metasilicate.
Three intervention strategies-trisodium phosphate, lactic acid, and sodium metasilicate--were examined for their in vitro antimicrobial activities in water at room temperature against a three-strain cocktail of Escherichia coli O157:H7 and a three-strain cocktail of "generic" E. coli. Both initial inhibition and recovery of injured cells were monitored. When 3.0% (wt/wt) lactic acid, pH 2.4, was inoculated with E. coli O157:H7 (approximately 6 log CFU/ml), viable microorganisms were recovered after a 20-min exposure to the acid. After 20 min in 1.0% (wt/wt) trisodium phosphate, pH 12.0, no viable E. coli O157:H7 microorganisms were detected. Exposure of E. coli O157:H7 to sodium metasilicate (5 to 10 s) at concentrations as low as 0.6%, pH 12.1, resulted in 100% inhibition with no recoverable E. coli O157:H7. No difference in inhibition profiles was detected between the E. coli O157:H7 and generic strains, suggesting that nonpathogenic strains may be used for in-plant sodium metasilicate studies.
Georgetown Technology Group, 11240 S.W. Lynnvale Drive, Portland, Oregon 97225, USA. gweber@easystreet.com
George H
GH
Weber
Judy K
JK
O'Brien
Fredric G
FG
Bender
D015169:Colony Count, Microbial; D004202:Disinfectants / Q000494:pharmacology*; D019453:Escherichia coli O157 / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000494:pharmacology; D010710:Phosphates / Q000494:pharmacology; D017640:Silicates / Q000494:pharmacology*; D013696:Temperature; D013997:Time Factors; D014871:Water Microbiology
D004202:Disinfectants; D010710:Phosphates; D017640:Silicates; C025349:sodium metasilicate; D019344:Lactic Acid; C018279:sodium phosphate