title: Recovery of Salmonella, Listeria monocytogenes, and Mycobacterium bovis from cheese entering the United States through a noncommercial land port of entry.
abstract: A joint multiagency project was initiated in response to a Salmonella outbreak in San Diego County, California, in 2004. Samples of cheese were collected during four 1-day operations at the San Ysidro port of entry, along the United States-Mexico border. Surveyed participants were persons crossing the border as pedestrians or in vehicles who had a minimum of 2.27 kg of cheese, which may suggest a potential diversion to illegal marketing. In addition, data were collected about the cheese to identify risk factors for cheese contamination. Two hundred four cheese samples were submitted to the California Animal Health and Food Safety Laboratory System-San Bernardino Branch and analyzed for potential food pathogens. Ninety-four percent (190 of 203) of the samples tested positive for alkaline phosphatase. Salmonella was detected from 13% (27 of 204) of the samples comprising 11 serogroups and 28 serotypes. Pulsed-field gel electrophoresis DNA fingerprinting analysis, performed following standardized methods, determined that an isolate obtained from this study had an indistinguishable pattern from a recent Salmonella enterica serovar Typhimurium var. Copenhagen epidemic in the San Diego County that was linked to 14 illnesses. Listeria spp. were detected from 4% (8 of 204) of the samples, and of these, half were identified as L. monocytogenes. Escherichia coli O157:H7 was not detected from any of the samples. Mycobacterium bovis was detected from one panela-style cheese sample. Nine additional samples yielded Mycobacterium spp.
authors.affiliation: California Animal Health and Food Safety Laboratory System, San Bernardino Branch, 105 West Central Avenue, San Bernardino, California 92408, USA. hkinde@ucdavis.edu
authors.forename: Hailu
authors.initials: H
authors.lastname: Kinde
authors.forename: Andrea
authors.initials: A
authors.lastname: Mikolon
authors.forename: Alfonso
authors.initials: A
authors.lastname: Rodriguez-Lainz
authors.forename: Cathy
authors.initials: C
authors.lastname: Adams
authors.forename: Richard L
authors.initials: RL
authors.lastname: Walker
authors.forename: Shannon
authors.initials: S
authors.lastname: Cernek-Hoskins
authors.forename: Scarlett
authors.initials: S
authors.lastname: Treviso
authors.forename: Michele
authors.initials: M
authors.lastname: Ginsberg
authors.forename: Robert
authors.initials: R
authors.lastname: Rast
authors.forename: Beth
authors.initials: B
authors.lastname: Harris
authors.forename: Janet B
authors.initials: JB
authors.lastname: Payeur
authors.forename: Steve
authors.initials: S
authors.lastname: Waterman
authors.forename: Alex
authors.initials: A
authors.lastname: Ardans
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D002140:California / Q000453:epidemiology; D002611:Cheese / Q000382:microbiology*; D003132:Commerce; D004196:Disease Outbreaks; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D006801:Humans; D008089:Listeria monocytogenes / Q000302:isolation & purification*; D009163:Mycobacterium bovis / Q000302:isolation & purification*; D012475:Salmonella / Q000302:isolation & purification*; D014481:United States
chemical_list: D000469:Alkaline Phosphatase