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.