| Abstrakt: |
The occurrence, serotype diversity, and antimicrobial resistance of Salmonellabacteria in commercial ground beef at retail establishments were investigated. Salmonellawas 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 Salmonellaisolates; predominant were Salmonellagroup B (9.6%), SalmonellaAnatum (8.9%), SalmonellaAgona (6.7%), SalmonellaInfantis (6.7%), and SalmonellaTyphimurium (5.9%). All Salmonellaisolates 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 Salmonellaisolates (27.4%) were multidrug resistant, and the majority corresponded to SalmonellaGroup B, SalmonellaAnatum, and SalmonellaTyphimurium. Three Salmonellaisolates were resistant to seven different antimicrobials. The frequency of Salmonellain 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. |
