title: Occurrence, serotype diversity, and antimicrobial resistance of salmonella in ground beef at retail stores in Jalisco state, Mexico.
abstract: The occurrence, serotype diversity, and antimicrobial resistance of Salmonella bacteria in commercial ground beef at retail establishments were investigated. Salmonella was isolated from 135 (56.7%) of 238 ground beef samples collected at the same number of butcher's shops located in three municipalities of Jalisco State, Mexico, during an 11-month period. The isolation frequency differed by municipality (P < 0.05) and was higher (P < 0.05) during the warm season (68.5%) than during the cold season (43.2%). Overall, 25 serotypes and 8 serogroups were identified among 135 Salmonella isolates; predominant were Salmonella group B (9.6%), Salmonella Anatum (8.9%), Salmonella Agona (6.7%), Salmonella Infantis (6.7%), and Salmonella Typhimurium (5.9%). All Salmonella isolates were tested for susceptibility to 11 antimicrobial drugs of human and veterinary use. Resistance to tetracycline was the most commonly observed (40.7%), followed by resistance to streptomycin (35.6%), trimethoprim-sulfamethoxazole (20.7%), and nalidixic acid (19.3%). Thirty-seven Salmonella isolates (27.4%) were multidrug resistant, and the majority corresponded to Salmonella Group B, Salmonella Anatum, and Salmonella Typhimurium. Three Salmonella isolates were resistant to seven different antimicrobials. The frequency of Salmonella in ground beef samples (56.7%) was higher than that observed in our previous investigation on beef carcasses (15.4%) at small abattoirs in the same region of Mexico. This may be a result of increasing contamination at these two points of the raw-beef production chain or may be an effect of the grinding process that facilitates a more-homogeneous pathogen distribution in the product. Poor hygiene, temperature abuse, and practices allowing cross-contamination during ground beef fabrication at these retail establishments increase the consumer's exposure to Salmonella.
authors.affiliation: Departamento de Salud Pública, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Km. 15.5 Carretera a Nogales, Zapopan, Jalisco, México 45110.
authors.forename: Elisa
authors.initials: E
authors.lastname: Cabrera-Diaz
authors.forename: Claudia M
authors.initials: CM
authors.lastname: Barbosa-Cardenas
authors.forename: Julia A
authors.initials: JA
authors.lastname: Perez-Montaño
authors.forename: Delia
authors.initials: D
authors.lastname: Gonzalez-Aguilar
authors.forename: Carlos
authors.initials: C
authors.lastname: Pacheco-Gallardo
authors.forename: Jeannette
authors.initials: J
authors.lastname: Barba
mesh_terms: D000003:Abattoirs; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002417:Cattle; D015169:Colony Count, Microbial; D024901:Drug Resistance, Multiple, Bacterial; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D006801:Humans; D008461:Meat Products / Q000382:microbiology*; D008800:Mexico / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D015995:Prevalence; D012475:Salmonella / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification; D012478:Salmonella Food Poisoning / Q000453:epidemiology / Q000517:prevention & control; D012703:Serotyping
chemical_list: D000900:Anti-Bacterial Agents