| Autor: |
Kudva IT; Department of Microbiology, Molecular Biology, and Biochemistry, University of Idaho, Moscow, Idaho 83843, USA., Jelacic S, Tarr PI, Youderian P, Hovde CJ |
| Jazyk: |
angličtina |
| Zdroj: |
Applied and environmental microbiology [Appl Environ Microbiol] 1999 Sep; Vol. 65 (9), pp. 3767-73. |
| DOI: |
10.1128/AEM.65.9.3767-3773.1999 |
| Abstrakt: |
Escherichia coli O157 antigen-specific bacteriophages were isolated and tested to determine their ability to lyse laboratory cultures of Escherichia coli O157:H7. A total of 53 bovine or ovine fecal samples were enriched for phage, and 5 of these samples were found to contain lytic phages that grow on E. coli O157:H7. Three bacteriophages, designated KH1, KH4, and KH5, were evaluated. At 37 or 4 degrees C, a mixture of these three O157-specific phages lysed all of the E. coli O157 cultures tested and none of the non-O157 E. coli or non-E. coli cultures tested. These results required culture aeration and a high multiplicity of infection. Without aeration, complete lysis of the bacterial cells occurred only after 5 days of incubation and only at 4 degrees C. Phage infection and plaque formation were influenced by the nature of the host cell O157 lipopolysaccharide (LPS). Strains that did not express the O157 antigen or expressed a truncated LPS were not susceptible to plaque formation or lysis by phage. In addition, strains that expressed abundant mid-range-molecular-weight LPS did not support plaque formation but were lysed in liquid culture. Virulent O157 antigen-specific phages could play a role in biocontrol of E. coli O157:H7 in animals and fresh foods without compromising the viability of other normal flora or food quality. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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