The Poultry Peril Spread by Drug-Resistant Salmonella

by: Rojan Samuel Daluz (Inosine)

Photo by Manjurul / iStock

    Salmonella spp. are major contributors of foodborne illness worldwide, ranking among the leading causes. In addition, the bacteria are known to be a public health threat, especially to poultry products. In recent studies in the Philippines, there were discovered trends showing the prevalence of multidrug-resistant (MDR) Salmonella strains in poultry meat, specifically in chicken meat, most likely due to the unnecessary or misuse of antibiotics, allowing for the dominance of antibiotic-resistant bacteria due to strong selective pressure. This finding raised concerns about food safety and the effectiveness of current antimicrobial treatments and procedures.

    Infections caused by Salmonella usually lead to symptoms such as fever, abdominal discomfort and pain, diarrhea, nausea, and vomiting, along with other symptoms related to foodborne illnesses. These signs and symptoms typically last for 2 to 7 days. Humans commonly get affected by this bacteria through the consumption of contaminated chicken that was poorly prepared, handled, or monitored. That said, the emergence of antibiotic-resistant bacteria produces complications to treatment options, and thus, highlights the need for meticulous monitoring.

    A recent study conducted by Nagpala et al. (2025) involved the analysis of 253 chicken meat samples from palengkes (wet markets) in Metro Manila. The study involved genomic characterization of the Salmonella strains isolated from chicken meat, followed by whole genome sequencing to identify the antibiotic resistance genes, virulence factors, and genetic profiles. Findings showed that a significant number of isolates carry resistance genes to critical class of antibiotics like phenicols, fluoroquinolones and cephalosporins, among others.

    Similarly, a local published study by Mora et al. (2024)  showed complementary findings. In this study, 105 S. enterica isolates from swine and chicken samples in Metro Manila were examined. From these samples, 65% were found to be resistant to at least one antibiotic, while 37% were MDR and 57% produced extended-β-lactamases. The genotypic analysis also identified genes encoding for resistance against tetracycline, streptomycin, and sulfonamide, among others. In addition, 155 virulence genes were identified, with some being associated with the host immune system modulation and intracellular survival.

    Overall, these studies emphasize the urgent need for comprehensive surveillance of antimicrobial resistance in the food supply chain. The impact of food safety and quality production on the health and well-being of consumers is something that should be highly regarded in different processes from farm to fork. Developing integral approaches and coordinated efforts to monitor, regulate, and control the spread of MDR pathogens is key towards safeguarding public health and ensuring the efficacy of antimicrobial treatments, both short and long term. By implementing strict regulations on antibiotic use in agriculture, integrating enhanced food safety practices, and disseminating proper public education on the proper food handling and preparation methods, the objective of producing safe and quality meat, free from substances that pose threats towards one’s health, can be attained. 

SOURCES

Bhat, K. A., Manzoor, T., Dar, M. A., Farooq, A., Allie, K. A., Wani, S. M., Dar, T. A., & Shah, A. A. (2022). Salmonella infection and pathogenesis. In IntechOpen eBooks. https://doi.org/10.5772/intechopen.102061

Levy, N., Hashiguchi, T. C. O., & Cecchini, M. (2022). Food safety policies and their effectiveness to prevent foodborne diseases in catering establishments: A systematic review and meta-analysis. Food Research International, 156, 111076. https://doi.org/10.1016/j.foodres.2022.111076

Mora, J. F. B., Meclat, V. Y. B., Calayag, A. M. B., Campino, S., Hafalla, J. C. R., Hibberd, M. L., Phelan, J. E., Clark, T. G., & Rivera, W. L. (2024). Genomic analysis of Salmonella enterica from Metropolitan Manila abattoirs and markets reveals insights into circulating virulence and antimicrobial resistance genotypes. Frontiers in Microbiology, 14. https://doi.org/10.3389/fmicb.2023.1304283

Nagpala, M. J. M., Mora, J. F. B., Pavon, R. D. N., & Rivera, W. L. (2025). Genomic characterization of antimicrobial-resistant Salmonella enterica in chicken meat from wet markets in Metro Manila, Philippines. Frontiers in Microbiology, 16. https://doi.org/10.3389/fmicb.2025.1496685

This article was originally published in the GENEWS May 2025 Issue.