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Characterization of Lipoteichoic Acids as Lactobacillus delbrueckii Phage Receptor Components. Liisa Räisänen, 2004.Lipoteichoic acids (LTAs) were purified from Lactobacillus delbrueckii subsp . lactis ATCC 15808 and its LL-H adsorption-resistant mutant, Ads-5, by hydrophobic interaction chromatography . L . delbrueckii phages (LL-H, the LL-H host range mutant, and JCL1032) were inactivated by these poly(glycerophosphate) type of LTAs in vitro in accordance to their adsorption to intact ATCC 15808 and Ads-5 cells . Ingestion of Salmonella enterica Serotype Poona by a Free-Living Nematode, Caenorhabditis elegans, and Protection against Inactivation by Produce Sanitizers. Krishaun N. Caldwell, 2003.Free-living nematodes are known to ingest food-borne pathogens and may serve as vectors to contaminate preharvest fruits and vegetables . Caenorhabditis elegans was selected as a model to study the effectiveness of sanitizers in killing Salmonella enterica serotype Poona ingested by free-living nematodes . Aqueous suspensions of adult worms that had fed on S . enterica serotype Poona were treated with produce sanitizers . Treatment with 20 µg of free chlorine/ml significantly (  = 0.05) reduced the population of S . enterica serotype Poona compared to results for treating worms with water (control) . However, there was no significant difference in the number of S . enterica serotype Poona cells surviving treatments with 20 to 500 µg of chlorine/ml, suggesting that reductions caused by treatment with 20 µg of chlorine/ml resulted from inactivation of S . enterica serotype Poona on the surface of C . elegans but not cells protected by the worm cuticle after ingestion . Treatment with Sanova (850 or 1,200 µg/ml), an acidified sodium chlorite sanitizer, caused reductions of 5.74 and 6.34 log10 CFU/worm, respectively, compared to reductions from treating worms with water . Treatment with 20 or 40 µg of Tsunami 200/ml, a peroxyacetic acid-based sanitizer, resulted in reductions of 4.83 and 5.34 log10 CFU/worm, respectively, compared to numbers detected on or in worms treated with water . Among the organic acids evaluated at a concentration of 2%, acetic acid was the least effective in killing S . enterica serotype Poona and lactic acid was the most effective . Treatment with up to 500 µg of chlorine/ml, 1% hydrogen peroxide, 2,550 µg of Sanova/ml, 40 µg of Tsunami 200/ml, or 2% acetic, citric, or lactic acid had no effect on the viability or reproductive behavior of C . elegans . Treatments were also applied to cantaloupe rind and lettuce inoculated with S . enterica serotype Poona or C . elegans that had ingested S . enterica serotype Poona . Protection of ingested S . enterica serotype Poona against sanitizers applied to cantaloupe was not evident; however, ingestion afforded protection of the pathogen on lettuce . These results indicate that S . enterica serotype Poona ingested by C . elegans may be protected against treatment with chlorine and other sanitizers, although the basis for this protection remains unclear .
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