title: Frequency and antimicrobial resistance of Salmonella serotypes on beef carcasses at small abattoirs in Jalisco State, Mexico.
abstract: The prevalence and antimicrobial resistance of Salmonella serotypes on beef carcasses from four small abattoirs in Jalisco State, Mexico, were investigated during a 10-month period. Following U.S. Department of Agriculture Food Safety and Inspection Service protocols, Salmonella  was isolated from 78 (15.4%) beef carcasses (n = 505) after the final carcass water wash. Isolation frequency differed by establishment (P < 0.05) and was higher (P < 0.05) during the wet season (May through September) for all establishments. Thirteen Salmonella  serotypes and four serogroups (partially serotyped isolates) were identified. The most prevalent were Salmonella enterica Give (24.4%), Salmonella Typhimurium (17.9%), and Salmonella Group B (14.1%). Antimicrobial susceptibility was tested against 11 drugs, and results  indicated that 46.2% of the isolates were resistant to tetracycline, 42.3% were resistant to streptomycin, 23.1% were resistant to chloramphenicol, 21.8% were resistant to trimethoprim-sulfamethoxazole, and 19.2% were resistant to gentamicin. No resistance to ceftriaxone or ciprofloxacin was  observed, and 33% of the isolates were resistant to three or more antimicrobials. Although Salmonella Give was the most prevalent serotype, 95% of the isolates of this serotype were susceptible to all antimicrobials tested. Antimicrobial resistance was more common in Salmonella  Typhimurium, and 93% (13 of 14) of the isolates of this serotype were resistant to at least five antimicrobials. The frequency of multidrug-resistant Salmonella isolates differed among establishments (P < 0.05) and may be related to the origin of the cattle presented for harvesting.  These findings highlight the need for control measures to reduce Salmonella prevalence on beef carcasses in small abattoirs in Mexico and for strategies to ensure the cautious use of antimicrobials in animal production to prevent and control the spread of antimicrobial-resistant foodborne  pathogens.
authors.affiliation: Departamento de Salud Pública, CUCBA, Universidad de Guadalajara, Km. 15.5 Carretera a Nogales, Zapopan, Jalisco, México 45110.
authors.forename: Julia A
authors.initials: JA
authors.lastname: Perez-Montaño
authors.forename: Delia
authors.initials: D
authors.lastname: Gonzalez-Aguilar
authors.forename: Jeannette
authors.initials: J
authors.lastname: Barba
authors.forename: Carlos
authors.initials: C
authors.lastname: Pacheco-Gallardo
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Campos-Bravo
authors.forename: Santos
authors.initials: S
authors.lastname: Garcia
authors.forename: Norma L
authors.initials: NL
authors.lastname: Heredia
authors.forename: Elisa
authors.initials: E
authors.lastname: Cabrera-Diaz
mesh_terms: D000003:Abattoirs; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002417:Cattle / Q000382:microbiology*; D015169:Colony Count, Microbial; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D006801:Humans; D008800:Mexico; D015995:Prevalence; D012475:Salmonella / Q000145:classification* / Q000187:drug effects* / Q000302:isolation & purification; D012703:Serotyping
chemical_list: D000900:Anti-Bacterial Agents