Microbiology and Biotechnology Letters (한국미생물·생명공학회지)

The Korean Society for Microbiology and Biotechnology (한국미생물·생명공학회)
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Virulence and Antimicrobial Resistance Gene Profiling of Salmonella Isolated from Swine Meat Samples in Abattoirs and Wet Markets of Metro Manila, Philippines

  • Rance Derrick N. Pavon (Pathogen-Host-Environment Interactions Research Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman) ;
  • Windell L. Rivera (Pathogen-Host-Environment Interactions Research Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman)
  • Received : 2023.06.26
  • Accepted : 2023.10.06
  • Published : 2023.12.28
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Abstract

Salmonella are Gram-negative pathogenic bacteria commonly found in food animals such as poultry and swine and potentially constitute risks and threats to food safety and public health through transmissible virulence and antimicrobial resistance (AMR) genes. Although there are previous studies in the Philippines regarding genotypic and phenotypic AMR in Salmonella, there are very few on virulence and their associations. Hence, this study collected 700 Salmonella isolates from swine samples in abattoirs and wet markets among four districts in Metro Manila and characterized their genotypic virulence and β-lactam AMR profiles. Gene frequency patterns and statistical associations between virulence and bla genes and comparisons based on location types (abattoirs and wet markets) and districts were also determined. High prevalence (>50%) of virulence genes was detected encompassing Salmonella pathogenicity islands (SPIs) 1-5 suggesting their pathogenic potential, but none possessed plasmid-borne virulence genes spvR and spvC. For bla, blaTEM was detected with high prevalence (>45%) and revealed significant associations to four SPI genes, namely, avrA, hilA, mgtC, and spi4R, which suggest high resistance potential particularly to β-lactam antibiotics and relationships with pathogenicity that remain mechanistically unestablished until now. Lastly, comparisons of location types and districts showed variations in gene prevalence suggesting effects from environmental factors throughout the swine production chain. This study provides vital data on the genotypic virulence and AMR of Salmonella from swine in abattoirs and wet markets that suggest their pathogenicity and resistance potential for policymakers to implement enforced surveillance and regulations for the improvement of the Philippine swine industry.

Keywords

Acknowledgement

The authors acknowledge Paolo D.G. Mendoza, Camille Andrea R. Flores, and Alyzza Marie B. Calayag for the technical support. This study was supported financially by the Department of Agriculture-Biotechnology Program Office (DABIOTECH-R1808) of the Philippines.

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