{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,27]],"date-time":"2026-05-27T17:46:20Z","timestamp":1779903980624,"version":"3.53.1"},"reference-count":45,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2025,3,8]],"date-time":"2025-03-08T00:00:00Z","timestamp":1741392000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Science Centre (Poland)","award":["2021\/41\/N\/NZ9\/00918 (PRELUDIUM-20)"],"award-info":[{"award-number":["2021\/41\/N\/NZ9\/00918 (PRELUDIUM-20)"]}]},{"name":"Minister of Science Republic of Poland","award":["2021\/41\/N\/NZ9\/00918 (PRELUDIUM-20)"],"award-info":[{"award-number":["2021\/41\/N\/NZ9\/00918 (PRELUDIUM-20)"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Antimicrobial resistance is spreading rapidly throughout the world. The food chain can be one of the routes of transmission for microorganisms containing drug-resistance genes and thus serve as a channel for their transmission. Environmental stress and methods of preventing the spread of microorganisms trigger adaptive responses in bacterial cells. The aim of the present study was to determine the effect of the stress induced by sub-inhibitory concentrations (SICs) of cadmium chloride and benzalkonium chloride on antibiotic resistance and the expression of selected virulence factors in Staphylococcus isolates from food. The study was conducted on strains of the species S. epidermidis, S. heamolyticus, S. saprophyticus, and S. aureus. The values of the minimum inhibitory concentration against erythromycin, tetracycline, and oxacillin were determined before and after the incubation of the tested strains under stress conditions. The ability to form biofilm and slime production was also investigated. The expression levels of the genes responsible for antibiotic resistance (blaZ, tetK, tetM, ermB, and mecA) and virulence (eno) were conducted using Real-Time PCR. The MIC values of the antibiotics tested against the strains analyzed were found to be elevated in the presence of SICs of benzalkonium chloride and cadmium chloride. Furthermore, the intensity of biofilm production was also increased. SICs of benzalkonium chloride induced the expression of the tetM, tetK, mecA, and blaZ genes in 75%, 66.6%, 33.3%, and 40% of the isolates tested, respectively. Similar treatment with cadmium chloride induced the expression of the same genes in 75%, 100%, 66.6%, and 40% of the strains. In both cases, the expression of the ermB gene was reduced in 100% of the isolates. The eno gene was found to be overexpressed in 66.6% of the strains following benzalkonium chloride stress, and in 100% of the strains following cadmium chloride stress. These findings suggest that in Staphylococcus spp. strains, changes in the expression of the genes encoding antibiotic resistance and virulence factors may occur in response to the applied stress factors. The results indicate the possibility of selecting more resistant and virulent strains due to the use of too low concentrations of disinfectants, which emphasizes the need to use appropriate inhibitory doses of disinfectants in the food industry.<\/jats:p>","DOI":"10.3390\/ijms26062429","type":"journal-article","created":{"date-parts":[[2025,3,10]],"date-time":"2025-03-10T06:59:59Z","timestamp":1741589999000},"page":"2429","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Effect of Sub-Inhibitory Concentrations of Quaternary Ammonium Compounds and Heavy Metals on Antibiotic Resistance and Expression of Virulence Factors Among Staphylococcus spp. from Dairy Products"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-6353-7089","authenticated-orcid":false,"given":"Zuzanna","family":"Byczkowska-Rostkowska","sequence":"first","affiliation":[{"name":"Department of Food Microbiology, Meat Technology and Chemistry, Faculty of Food Science, University of Warmia and Mazury in Olsztyn, Plac Cieszy\u0144ski 1, 10-726 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6855-6804","authenticated-orcid":false,"given":"Joanna","family":"Gajewska","sequence":"additional","affiliation":[{"name":"Department of Food Microbiology, Meat Technology and Chemistry, Faculty of Food Science, University of Warmia and Mazury in Olsztyn, Plac Cieszy\u0144ski 1, 10-726 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6273-1031","authenticated-orcid":false,"given":"Anna","family":"Zadernowska","sequence":"additional","affiliation":[{"name":"Department of Food Microbiology, Meat Technology and Chemistry, Faculty of Food Science, University of Warmia and Mazury in Olsztyn, Plac Cieszy\u0144ski 1, 10-726 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9695-1470","authenticated-orcid":false,"given":"Wioleta","family":"Chaj\u0119cka-Wierzchowska","sequence":"additional","affiliation":[{"name":"Department of Food Microbiology, Meat Technology and Chemistry, Faculty of Food Science, University of Warmia and Mazury in Olsztyn, Plac Cieszy\u0144ski 1, 10-726 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e12358","DOI":"10.1111\/jfs.12358","article-title":"Formation and Development of Staphylococcus Biofilm: With Focus on Food Safety","volume":"37","author":"Miao","year":"2017","journal-title":"J. Food Saf."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Rajamanickam, K., Yang, J., and Chidambaram, S.B. (2020). Enhancing Drug Efficacy against Mastitis Pathogens\u2014An In Vitro Pilot Study in Staphylococcus aureus and Staphylococcus epidermidis. Animals, 10.","DOI":"10.3390\/ani10112117"},{"key":"ref_3","first-page":"792","article-title":"Journal of Global Antimicrobial Resistance Relationship between Virulence Factors and Antimicrobial Resistance in Staphylococcus aureus from Bovine Mastitis","volume":"22","author":"Karen","year":"2020","journal-title":"Integr. Med. Res."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"677","DOI":"10.1080\/1828051X.2020.1871428","article-title":"Staphylococcus aureus Enterotoxin in Food of Animal Origin and Staphylococcal Food Poisoning Risk Assessment from Farm to Table","volume":"20","author":"Grispoldi","year":"2021","journal-title":"Ital. J. Anim. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Chaj\u0119cka-Wierzchowska, W., Gajewska, J., Wi\u015bniewski, P., and Zadernowska, A. (2020). Enterotoxigenic Potential of Coagulase-Negative Staphylococci from Ready-to-Eat Food. Pathogens, 9.","DOI":"10.3390\/pathogens9090734"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1016\/j.tifs.2019.11.006","article-title":"Interplay of Antibiotic Resistance and Food-Associated Stress Tolerance in Foodborne Pathogens","volume":"95","author":"Liao","year":"2019","journal-title":"Trends Food Sci. Technol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"103549","DOI":"10.1016\/j.micpath.2019.103549","article-title":"Stress Tolerance of Staphylococcus aureus with Different Antibiotic Resistance Profiles","volume":"133","author":"Ma","year":"2019","journal-title":"Microb. Pthogenes."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"464","DOI":"10.1128\/AEM.02633-14","article-title":"Quaternary Ammonium Biocides: Efficacy in Application","volume":"81","author":"Gerba","year":"2015","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"296","DOI":"10.1016\/j.copbio.2015.03.018","article-title":"Quaternary Ammonium Disinfectants: Microbial Adaptation, Degradation and Ecology","volume":"33","author":"Tezel","year":"2015","journal-title":"Curr. Opin. Biotechnol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/j.fm.2016.10.037","article-title":"Effects of Exposure to Quaternary-Ammonium-Based Biocides on Antimicrobial Susceptibility and Tolerance to Physical Stresses in Bacteria from Organic Foods","volume":"63","author":"Gadea","year":"2017","journal-title":"Food Microbiol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"651","DOI":"10.1007\/s10534-016-9941-5","article-title":"Cd2+ Extrusion by P-Type Cd2+-ATPase of Staphylococcus aureus 17810R via Energy-Dependent Cd2+\/H+ Exchange Mechanism","volume":"29","author":"Tynecka","year":"2016","journal-title":"BioMetals"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Marzoli, F., Turchi, B., Pedonese, F., Torracca, B., Bertelloni, F., Cilia, G., Cerri, D., and Fratini, F. (2021). Coagulase Negative Staphylococci from Ovine Bulk-Tank Milk: Effects of the Exposure to Sub-Inhibitory Concentrations of Disinfectants for Teat-Dipping. Comp. Immunol. Microbiol. Infect. Dis., 76.","DOI":"10.1016\/j.cimid.2021.101656"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1016\/j.fm.2017.01.003","article-title":"Effect of Sub-Inhibitory Concentrations of Biocides on the Architecture and Viability of MRSA Biofilms","volume":"65","author":"Capita","year":"2017","journal-title":"Food Microbiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"e02685-20","DOI":"10.1128\/AAC.02685-20","article-title":"Staphylococcus saprophyticus Causing Infections in Humans Is Associated with High Resistance to Heavy Metals","volume":"65","author":"Lawal","year":"2021","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_15","first-page":"171","article-title":"Metalotioneiny Bakteryjne","volume":"56","author":"Znajewska","year":"2017","journal-title":"Postep. Mikrobiol."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Mclaughlin, M.J., and Zhao, F. (2020). Managing Cadmium in Agricultural Systems, Elsevier.","DOI":"10.1016\/bs.agron.2020.10.004"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1016\/j.bej.2013.01.014","article-title":"Biofilm Formation and Heavy Metal Resistance by an Environmental Pseudomonas","volume":"78","author":"Chien","year":"2013","journal-title":"Biochem. Eng. J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"25076","DOI":"10.1021\/acsomega.1c04396","article-title":"Heavy Metals Induced Modulations in Growth, Physiology, Cellular Viability, and Biofilm Formation of an Identified Bacterial Isolate","volume":"6","author":"Syed","year":"2021","journal-title":"ACS Omega"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/j.fm.2016.12.009","article-title":"Antimicrobial Resistance and Its Association with Tolerance to Heavy Metals in Agriculture Production","volume":"64","author":"Yu","year":"2017","journal-title":"Food Microbiol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"350","DOI":"10.1089\/fpd.2016.2241","article-title":"Effect of Sub-Lethal Concentrations of Biocides on the Structural Parameters and Viability of the Biofilms Formed by Salmonella Typhimurium","volume":"14","author":"Capita","year":"2017","journal-title":"Foodborne Pathog. Dis."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1089\/fpd.2018.2472","article-title":"Effect of Low Doses of Disinfectants on the Biofilm-Forming Ability of Listeria monocytogenes","volume":"16","author":"Capita","year":"2019","journal-title":"Foodborne Pathog. Dis."},{"key":"ref_22","first-page":"2497","article-title":"Isolation and Molecular Identification of Virulence, Antimicrobial and Heavy Metal Resistance Genes in Staphylococcus aureus","volume":"11","author":"Dweba","year":"2019","journal-title":"Pathogens"},{"key":"ref_23","first-page":"247","article-title":"Antibiotic Resistance of Bacteria Isolated from Heavy Metal-Polluted Soils with Different Land Uses","volume":"10","author":"Sinegani","year":"2017","journal-title":"Integr. Med. Res."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Adamski, P., Byczkowska-Rostkowska, Z., Gajewska, J., Zakrzewski, A.J., and K\u0142\u0119bukowska, L. (2023). Prevalence and Antibiotic Resistance of Bacillus sp. Isolated from Raw Milk. Microorganisms, 11.","DOI":"10.3390\/microorganisms11041065"},{"key":"ref_25","first-page":"10","article-title":"Antybiotyki i Antybiotykooporno\u015b\u0107 w Przemy\u015ble Mleczarskim","volume":"12","author":"Gajewska","year":"2022","journal-title":"Polish Dairy J."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Rozman, U., Pu\u0161nik, M., Kmetec, S., Duh, D., and Turk, S.\u0160. (2021). Reduced Susceptibility and Increased Resistance of Bacteria against Disinfectants: A Systematic Review. Microorganisms, 9.","DOI":"10.3390\/microorganisms9122550"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"456","DOI":"10.1089\/mdr.2023.0074","article-title":"Biocides in the Hospital Environment: Application and Tolerance Development","volume":"29","author":"Geraldes","year":"2023","journal-title":"Microb. Drug Resist."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"570","DOI":"10.1021\/acs.est.6b03132","article-title":"Subinhibitory Concentrations of Disinfectants Promote the Horizontal Transfer of Multidrug Resistance Genes within and across Genera","volume":"51","author":"Zhang","year":"2017","journal-title":"Environ. Sci. Technol."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Ghaly, T.M., Chow, L., Asher, A.J., Waldron, L.S., and Gillings, M.R. (2017). Evolution of Class 1 Integrons: Mobilization and Dispersal via Food-Borne Bacteria. PLoS ONE, 12.","DOI":"10.1371\/journal.pone.0179169"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1038\/s43856-021-00070-8","article-title":"Resisting Disinfectants","volume":"2","author":"Verbrugh","year":"2022","journal-title":"Commun. Med."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Ricke, S.C., Dawoud, T.M., Kim, S.A., Park, S.H., and Kwon, Y.M. (2018). Salmonella Cold Stress Response: Mechanisms and Occurrence in Foods, Elsevier Inc.. [1st ed.].","DOI":"10.1016\/bs.aambs.2018.03.001"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"399","DOI":"10.1016\/j.jgar.2019.10.021","article-title":"Resistance and Cross-Resistance in Staphylococcus spp. Strains Following Prolonged Exposure to Different Antiseptics","volume":"21","author":"Dopcea","year":"2020","journal-title":"J. Glob. Antimicrob. Resist."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1016\/j.envpol.2018.01.032","article-title":"Sub-Inhibitory Concentrations of Heavy Metals Facilitate the Horizontal Transfer of Plasmid-Mediated Antibiotic Resistance Genes in Water Environment","volume":"237","author":"Zhang","year":"2018","journal-title":"Environ. Pollut."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Gajewska, J., Chaj\u0119cka-Wierzchowska, W., Byczkowska-Rostkowska, Z., and Saki, M. (2023). Biofilm Formation Capacity and Presence of Virulence Determinants among Enterococcus Species from Milk and Raw Milk Cheeses. Life, 13.","DOI":"10.3390\/life13020495"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Gajewska, J., and Chaj\u0119cka-Wierzchowska, W. (2020). Biofilm Formation Ability and Presence of Adhesion Genes among Coagulase-Negative and Coagulase-Positive Staphylococci Isolates from Raw Cow\u2019s Milk. Pathogens, 9.","DOI":"10.3390\/pathogens9080654"},{"key":"ref_36","unstructured":"(2019). International Standard Agents and Evaluation of Performance Method for Testing the in Vitro Activity (Standard No. ISO 20776-1:19(E))."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Gajewska, J., Chaj\u0119cka-Wierzchowska, W., and Zadernowska, A. (2022). Occurrence and Characteristics of Staphylococcus aureus Strains along the Production Chain of Raw Milk Cheeses in Poland. Molecules, 27.","DOI":"10.3390\/molecules27196569"},{"key":"ref_38","unstructured":"Clinical and Laboratory Standards Institute (2020). Performance Standards for Antimicrobial Susceptibility Testing, Clinical and Laboratory Standards Institute."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"371","DOI":"10.1590\/S1517-83822012000100044","article-title":"Biofilm Production by Clinical Staphylococci Strains from Canine Otitis","volume":"43","author":"Moreira","year":"2012","journal-title":"Brazilian J. Microbiol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"891","DOI":"10.1111\/j.1600-0463.2007.apm_630.x","article-title":"Quantification of Biofilm in Microtiter Plates","volume":"115","author":"Hola","year":"2007","journal-title":"Apmis"},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Zarzecka, U., Zadernowska, A., and Chaj\u0119cka-Wierzchowska, W. (2022). Effects of Osmotic and High Pressure Stress on Expression of Virulence Factors among Enterococcus Spp. Isolated from Food of Animal Origin. Food Microbiol., 102.","DOI":"10.1016\/j.fm.2021.103900"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/j.nfs.2023.05.003","article-title":"Effect of Sous-Vide Processing of Fish on the Virulence and Antibiotic Resistance of Listeria monocytogenes","volume":"31","author":"Zakrzewski","year":"2023","journal-title":"NFS J."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Kot, B., Sytykiewicz, H., and Sprawka, I. (2018). Expression of the Biofilm-Associated Genes in Methicillin-Resistant Staphylococcus aureus in Biofilm and Planktonic Conditions. Int. J. Mol. Sci., 19.","DOI":"10.3390\/ijms19113487"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Fl\u00f3rez, A.B., Alegr\u00eda, \u00c1., Rossi, F., Delgado, S., Felis, G.E., Torriani, S., and Mayo, B. (2014). Molecular Identification and Quantification of Tetracycline and Erythromycin Resistance Genes in Spanish and Italian Retail Cheeses. BioMed Res. Int., 2014.","DOI":"10.1155\/2014\/746859"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"238","DOI":"10.1111\/lam.13417","article-title":"Antibacterial Activity and Synergy of Antibiotics with Sanguisorbigenin Isolated from Sanguisorba Officinalis L. against Methicillin-Resistant Staphylococcus aureus","volume":"72","author":"Wang","year":"2021","journal-title":"Lett. Appl. Microbiol."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/26\/6\/2429\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T16:49:20Z","timestamp":1760028560000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/26\/6\/2429"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,3,8]]},"references-count":45,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2025,3]]}},"alternative-id":["ijms26062429"],"URL":"https:\/\/doi.org\/10.3390\/ijms26062429","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,3,8]]}}}