title: Mosaic structure of Shiga-toxin-2-encoding phages isolated from Escherichia coli O157:H7 indicates frequent gene exchange between lambdoid phage genomes.
abstract: Shiga-toxin-2 (stx(2))-encoding bacteriophages were isolated from Norwegian Escherichia coli O157:H7 isolates of cattle and human origin. The phages were characterized by restriction enzyme analysis, hybridization with probes for toxin genes and selected phage DNA such as the P gene, integrase gene and IS1203, and by PCR studies and partial sequencing of selected DNA regions in the integrase to stx(2) region of the phages. The stx(2)-phage-containing bacteria from which inducible phages were detected produced similar amounts of toxin, as shown by a Vero cell assay. The results indicate that the population of stx(2)-carrying phages is heterogeneous, although the phages from epidemiologically linked E. coli O157:H7 isolates were similar. There appears to have been frequent recombination of stx(2) phages with other lambdoid phages.
authors: Department of Pharmacology, Microbiology and Food Hygiene, The Norwegian School of Veterinary Science, PO Box 8146 Dep., N-0033 Oslo, Norway1.
authors: Birgit K
authors: BK
authors: Johansen
authors: Department of Pharmacology, Microbiology and Food Hygiene, The Norwegian School of Veterinary Science, PO Box 8146 Dep., N-0033 Oslo, Norway1.
authors: Yngvild
authors: Y
authors: Wasteson
authors: Department of Pharmacology, Microbiology and Food Hygiene, The Norwegian School of Veterinary Science, PO Box 8146 Dep., N-0033 Oslo, Norway1.
authors: Per E
authors: PE
authors: Granum
authors: Department of Pharmacology, Microbiology and Food Hygiene, The Norwegian School of Veterinary Science, PO Box 8146 Dep., N-0033 Oslo, Norway1.
authors: Sigrid
authors: S
authors: Brynestad
mesh_terms: D000818:Animals; D010582:Bacteriophage lambda / Q000235:genetics*; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology; D002675:Child, Preschool; D002522:Chlorocebus aethiops; D003090:Coliphages / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary; D019453:Escherichia coli O157 / Q000378:metabolism / Q000472:pathogenicity / Q000821:virology*; D005260:Female; D022761:Gene Transfer, Horizontal; D014644:Genetic Variation; D016679:Genome, Viral; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length; D011995:Recombination, Genetic; D022641:Shiga Toxin 2 / Q000235:genetics* / Q000378:metabolism / Q000633:toxicity; D014709:Vero Cells; D014775:Virus Activation
chemical_list: D004279:DNA, Viral; D022641:Shiga Toxin 2