title: Enumeration of Escherichia coli O157:H7 in Outbreak-Associated Beef Patties.
abstract: An outbreak of five cases of Escherichia coli O157 infection that occurred in Canada in 2012 was linked to frozen beef patties seasoned with garlic and peppercorn. Unopened retail packs of beef patties from the implicated production lot were recovered and analyzed to enumerate E. coli O157, other E. coli strains, and total coliforms. E. coli O157 was not recovered by direct enumeration on selective agar media. E. coli O157 in the samples was estimated at 3.1 most probable number per 140 g of beef patty, other E. coli was 11 CFU/g, and coliforms were 120 CFU/g. These results indicate that the presence of E. coli O157 in ground beef at levels below 0.1 CFU/g may cause outbreaks. However, the roles of temperature abuse, undercooking, and crosscontamination in amplifying the risk are unknown.
authors.affiliation: Health Canada, Bureau of Microbial Hazards, 251 Sir Frederick Banting Driveway, P.L. 2204E, Ottawa, Ontario, Canada K1A 0K9. alex.gill@hc-sc.gc.ca.
authors.forename: Alexander
authors.initials: A
authors.lastname: Gill
authors.affiliation: Canadian Food Inspection Agency, 2301 Midland Avenue, Scarborough, Ontario, Canada M1P 4R7.
authors.forename: George
authors.initials: G
authors.lastname: Huszczynski
mesh_terms: D000818:Animals; D002170:Canada; D002417:Cattle; D002648:Child; D015169:Colony Count, Microbial; D004196:Disease Outbreaks; D019453:Escherichia coli O157; D005516:Food Microbiology; D006801:Humans; D008461:Meat Products; D000069466:Red Meat