Antimicrobial resistance and serotype distribution of Salmonella spp. isolated from fresh foods in Cambodia.

AIMS

To determine the Salmonella serotype distribution, antimicrobial resistance profiles, and antimicrobial resistance genes (ARGs) in food samples obtained from local markets in a low-income urban setting and nearby farms in Cambodia.

METHODS AND RESULTS

One hundred and thirty-nine Salmonella isolates from various food sources were tested for antibiotic susceptibility using a panel of 12 antibiotics, and 81 selected Salmonella isolates were further sequenced for serotype distribution and ARG identification. The results showed that 71% (99/139) of the isolates exhibited resistance to at least one antibiotic, with 39% (39/99) classified as multidrug-resistant (MDR). The highest resistance was observed against azithromycin (37%), followed by oxytetracycline (35%). A total of 32 serotypes were identified, with the six most common being S. Corvallis (7%), S. Haifa (6%), S. Weltevreden (6%), S. Agona (5%), S. Kentucky (5%), and S. Livingstone (5%). A broad range of ARGs was observed across multiple antibiotic classes, including macrolides, aminoglycosides, tetracyclines, phenicols, fluoroquinolones, sulfonamide-trimethoprim, beta-lactams, and MDR genes.

CONCLUSIONS

The results highlight the potential role of fresh food products in the widespread dissemination of Salmonella strains resistant to multiple antibiotics.