title: Characterization of Listeria monocytogenes isolates from cattle and ground beef by pulsed-field gel electrophoresis.
abstract: The aims of this study were to determine the occurrence of Listeria monocytogenes in cattle feces and ground beef, to characterize these strains by pulsed-field gel electrophoresis and to compare them to three listeria strains found in humans. Cattle from different origins (n = 250) and ground beef obtained from supermarkets (n = 40) were sampled. The results show low occurrence in cattle feces (0.4 %) but a higher presence in ground beef (37 %). An important part of the ground beef strains (80 %) had > 95 % similarity with a strain isolated from a human sporadic case and the ATCC 19115 used as control. The strain isolated from cattle feces had 93 % similarity to clone 009, previously associated with a listeriosis outbreak related to cheese. Cattle and ground beef can harbor virulent L. monocytogenes strains. Further studies in animals and animal products are needed to improve listeriosis control.
authors.affiliation: Laboratorio de Microbiología y Probióticos, INTA, Universidad de Chile, Santiago, Chile. claudia.foerster@gmail.com
authors.forename: Claudia
authors.initials: C
authors.lastname: Foerster
authors.forename: Lorena
authors.initials: L
authors.lastname: Vidal
authors.forename: Miriam
authors.initials: M
authors.lastname: Troncoso
authors.forename: Guillermo
authors.initials: G
authors.lastname: Figueroa
mesh_terms: D000003:Abattoirs; D000818:Animals; D015373:Bacterial Typing Techniques / Q000379:methods*; D002417:Cattle / Q000382:microbiology*; D002611:Cheese / Q000382:microbiology; D002677:Chile / Q000453:epidemiology; D004269:DNA, Bacterial / Q000032:analysis; D003612:Dairying; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005243:Feces / Q000382:microbiology; D005506:Food Contamination; D005511:Food Handling; D005516:Food Microbiology; D006801:Humans; D008089:Listeria monocytogenes / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D008088:Listeriosis / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission; D008461:Meat Products / Q000382:microbiology*; D014774:Virulence
chemical_list: D004269:DNA, Bacterial