Abstract

FOERSTER, Claudia; VIDAL, Lorena; TRONCOSO, Miriam  and  FIGUEROA, Guillermo. Characterization of Listeria monocytogenes isolates from cattle and ground beef by pulsed-field gel electrophoresis. Rev. argent. microbiol. [online]. 2012, vol.44, n.3, pp.195-200. ISSN 0325-7541.

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.

Keywords : Listeria monocytogenes; Cattle ground beef; Pulsed-field gel electrophoresis; Chile.

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