Efflux pump-associated antimicrobial resistance genes in Staphylococcus spp. from dairy and meat samples

Sep 29, 2026

Investigates phenotypic resistance and the distribution of efflux pump-associated antimicrobial resistance genes in Staphylococcus spp. isolated from dairy and meat samples. A total of 132 samples were analyzed; 26 resistant isolates were confirmed by 16S rDNA sequencing and assessed for MIC changes using microdilution and reserpine inhibition. Real-time PCR detected key efflux genes and showed reserpine reduced MIC values, indicating efflux-mediated tolerance.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages11

Reading Time28 min

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Background/aim

Materials and methods

Results

Conclusion

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Graphical abstract

Introduction

Turkish Journal of Biology | Volume 49 Number 7 | Article 9 | | --- | --- | | 12-29-2025
Efflux pump-associated antimicrobial resistance genes in Staphylococcus spp. from dairy and meat samples
M. BURCU KÜLAHCI
SUMRU ÇITAK
Follow this and additional works at: [https://journals.tubitak.gov.tr/biology](https://journals.tubitak.gov.tr/biology)
Part of the Biology Commons | | Recommended Citation KÜLAHCI, M, & ÇITAK, S (2025) . Efflux pump-associated antimicrobial resistance genes in Staphylococcus [spp. fr](spp. fr)om dairy and meat samples. Turkish Journal of Biology 49 (7): 825-834. [https://doi.org/10.55730/1300-0152.2783](https://doi.org/10.55730/1300-0152.2783) This work is licensed under a Creative Commons Attribution 4.0 International License. This Research Article is brought to you for free and open access by TÜBİTAK Academic Journals. It has been accepted for inclusion in Turkish Journal of Biology by an authorized editor of TÜBİTAK Academic Journals. For more information, please contact [academic.publications@tubitak.gov.tr](academic.publications@tubitak.gov.tr) |
| Turkish Journal of Biology [http://journals.tubitak.gov.tr/biology/](http://journals.tubitak.gov.tr/biology/)

Research Article | Turk J Biol
(2025) 49: 825-834
© TÜBİTAK
doi:10.55730/1300-0152.2783 | | --- | --- | --- | Efflux pump-associated antimicrobial resistance genes in Staphylococcus spp. from dairy and meat samples * Meryem Burcu KÜLAHCI 􀁋, Sumru ÇITAK􀁋 Department of Biology, Faculty of Science, Gazi University, Ankara, Turkiye Received: 29.08.2025 Accepted/Published Online: 06.10.2025 Final Version: 29.12.2025 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 ofefflux 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. Key words: Staphylococcus spp., efflux pump, antimicrobial resistance, biocide tolerance, reserpine Graphical abstract * [Correspondence: m

FAQs

What was the study’s main objective?

To investigate phenotypic antimicrobial resistance and the distribution of efflux pump-associated resistance genes in Staphylococcus spp. from dairy and meat samples.

How were resistant isolates identified and tested?

Staphylococcus spp. were isolated from 132 dairy and meat samples, resistance was evaluated by microdilution, resistant isolates were identified using 16S rDNA sequencing, and reserpine effects on MIC were assessed via microdilution tests.

Which efflux pump genes were most frequently detected?

The most frequently detected 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.

What did reserpine inhibition tests show?

Reserpine reduced MIC values across cefuroxime-resistant isolates and in a subset of tetracycline- and nitrofurantoin-resistant strains, and it also lowered MICs for triclosan and povidone-iodine, supporting a role for efflux pumps.

Sep 29, 2026

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