Turkish Journal of Biology
Abstract
Background/aim: This study aimed to investigate the phenotypic resistance and distribution of efflux pump-associated antimicrobial resistance genes in Staphylococcus spp. isolated from dairy and meat samples. Antimicrobial resistance in foodborne bacteria increases with antibiotic exposure and biocides, particularly through efflux mechanisms. Thus, monitoring potential genetic reservoirs in the food chain is very important. Materials and methods: A total of 132 dairy and meat samples were collected for the study, and Staphylococcus spp. were isolated using Mannitol salt phenol red agar. Antimicrobial susceptibility was evaluated using the Clinical and Laboratory Standards Institute’s microdilution method. Twenty-six resistant isolates were identified by 16S rDNA sequencing. The effect of reserpine on MIC values was evaluated using microdilution tests to assess the role of efflux pumps in antibiotic resistance and biocide tolerance. Antibiotic resistance and efflux pump genes were detected using real-time PCR with specific primers. Results: Of the 77 isolates evaluated, 26 (33.8%) were resistant to at least one antibiotic. Resistance to tetracycline (69.2%) and cefuroxime (38.5%) were the most common. The administration of reserpine reduced minimum inhibitory concentration (MIC) values across all cefuroxime-resistant isolates and in a subset of tetracycline- and nitrofurantoin-resistant strains, suggesting the potential involvement of efflux pumps. It also lowered MICs for triclosan (46.7%) and povidone-iodine (32%). The most frequently detected efflux pump genes were smr (88.5%), efrA (84.6%), efrB (80.8%), mdeA (84.6%), and norE (80.8%). qacA/B was not detected in any isolate. Conclusion: Genes encoding efflux pump proteins were commonly found in Staphylococcus spp. isolated from dairy and meat samples. Reserpine inhibition tests confirmed the phenotypic effects of these genes. These results suggest efflux-mediated resistance can significantly impact antibiotic tolerance and biocides in foodborne isolates. Continued surveillance and control strategies are essential to limit the spread of these resistance genes in the food chain.
DOI
10.55730/1300-0152.2783
Keywords
Staphylococcus spp., efflux pump, antimicrobial resistance, biocide tolerance, reserpine
First Page
825
Last Page
834
Publisher
The Scientific and Technological Research Council of Türkiye (TÜBİTAK)
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
KÜLAHCI, M, & ÇITAK, S (2025). Efflux pump-associated antimicrobial resistance genes in Staphylococcus spp. from dairy and meat samples. Turkish Journal of Biology 49 (7): 825-834. https://doi.org/10.55730/1300-0152.2783
