Characterization of 4 T1-like lytic bacteriophages that lyse Shiga-toxin  Escherichia coli  O157:H7.
Bacteriophages are associated with reduced fecal shedding of Shiga-toxin-producing Escherichia coli O157:H7 (STEC O157:H7) in cattle. Four phages exhibiting activity against 12 of 14 STEC O157:H7 strains, representing 11 common phage types, were isolated. Phages did not lyse non-O157 E. coli, with 11 of the 12 STEC strains exhibiting extreme susceptibility (average multiplicity of infection (MOI) = 0.0003-0.0007). All phages had icosahedral heads with tapered, noncontractile tails, a morphology indicative of T1-like Siphoviridae. Genome size of all phages was ∼44 kb, but EcoRІ or HindIII digestion profiles differed among phages. Based on restriction enzyme digestion profiles, phages AHP24, AHS24, and AHP42 were more related (66.7%-82.4%) to each other than to AKS96, while AHP24 and AHS24, isolated from the same feedlot pen, exhibited the highest identity (88.9%-92.3%). Phages AHP24 and AHS24 exhibited the broadest host range and strongest lytic activity against STEC O157:H7, making them strong candidates for biocontrol of this bacterium in cattle.
Lethbridge Research Centre, Agriculture and Agri-Food Canada, AB, Canada.
Yan D
YD
Niu
Kim
K
Stanford
Hans-W
HW
Ackermann
Tim A
TA
McAllister
D000818:Animals; D001435:Bacteriophages / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000648:ultrastructure; D002417:Cattle; D004262:DNA Restriction Enzymes / Q000378:metabolism; D019453:Escherichia coli O157 / Q000821:virology*; D005243:Feces / Q000382:microbiology / Q000821:virology; D016679:Genome, Viral / Q000235:genetics; D058507:Host Specificity; D010802:Phylogeny; D015183:Restriction Mapping
D004262:DNA Restriction Enzymes