{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,16]],"date-time":"2026-04-16T09:57:57Z","timestamp":1776333477857,"version":"3.51.2"},"reference-count":66,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,4,16]],"date-time":"2026-04-16T00:00:00Z","timestamp":1776297600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100018818","name":"Development and Innovation Office","doi-asserted-by":"publisher","award":["NKFIH PD 147156"],"award-info":[{"award-number":["NKFIH PD 147156"]}],"id":[{"id":"10.13039\/501100018818","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100018818","name":"Development and Innovation Office","doi-asserted-by":"publisher","award":["NKFIH PD 142122"],"award-info":[{"award-number":["NKFIH PD 142122"]}],"id":[{"id":"10.13039\/501100018818","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100018818","name":"Development and Innovation Office","doi-asserted-by":"publisher","award":["2021-1.2.6-T\u00c9T-IPARI-MA-2022-00015"],"award-info":[{"award-number":["2021-1.2.6-T\u00c9T-IPARI-MA-2022-00015"]}],"id":[{"id":"10.13039\/501100018818","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100018818","name":"Development and Innovation Office","doi-asserted-by":"publisher","award":["2024-2.1.3-POC-2025-00004"],"award-info":[{"award-number":["2024-2.1.3-POC-2025-00004"]}],"id":[{"id":"10.13039\/501100018818","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Office","award":["2024-2.1.3-POC"],"award-info":[{"award-number":["2024-2.1.3-POC"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>Background: Respiratory tract infections remain among the most common indications for antibiotic therapy and represent a major driver of antimicrobial resistance. The ability of respiratory pathogens to form biofilms further contributes to treatment failure and recurrence. This study aimed to evaluate the antibiotic adjuvant potential of selected essential oil components against clinically relevant respiratory bacteria and to determine whether planktonic synergistic interactions translate into early-stage antibiofilm efficacy. Thymol, eugenol, trans-cinnamaldehyde, and terpinen-4-ol were tested against Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae, Haemophilus parainfluenzae, Moraxella catarrhalis, methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa. Methods: Minimum inhibitory concentrations were determined by broth microdilution. Synergistic interactions with clinically relevant antibiotics were assessed using the checkerboard method and fractional inhibitory concentration index (FICI) analysis. Selected combinations were further evaluated in a 6 h crystal violet-based early-stage biofilm model. Gram-positive strains generally exhibited higher susceptibility to the tested components than Gram-negative bacteria. Results: Synergistic interactions (FICI \u2264 0.5) were most frequently observed between \u03b2-lactam antibiotics and phenolic components, particularly thymol and trans-cinnamaldehyde. Strong synergy was detected for vancomycin-eugenol against MRSA and for amoxicillin\/clavulanic acid\u2013cinnamaldehyde against M. catarrhalis. Importantly, synergistic combinations translated into significantly enhanced inhibition of early biofilm formation, increasing inhibition rates by 15\u201340% compared to antibiotic monotherapy (p &lt; 0.05). Selected essential oil components enhanced the antibacterial activity of clinically relevant antibiotics and effectively potentiated early-stage biofilm inhibition. Conclusions: These findings support further investigation of phytochemical-antibiotic combinations as potential adjunct strategies in respiratory infection management.<\/jats:p>","DOI":"10.3390\/antibiotics15040403","type":"journal-article","created":{"date-parts":[[2026,4,16]],"date-time":"2026-04-16T09:04:42Z","timestamp":1776330282000},"page":"403","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Antibiotic Adjuvant Potential of Selected Essential Oil Components Against Respiratory Pathogens: From Planktonic Synergy to Early-Stage Biofilm Inhibition"],"prefix":"10.3390","volume":"15","author":[{"given":"Vikt\u00f3ria Lilla","family":"Bal\u00e1zs","sequence":"first","affiliation":[{"name":"Department of Pharmacognosy, Faculty of Pharmacy, University of P\u00e9cs, 7624 P\u00e9cs, Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rita","family":"Filep","sequence":"additional","affiliation":[{"name":"Department of Pharmacognosy, Faculty of Pharmacy, University of P\u00e9cs, 7624 P\u00e9cs, Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-1989-116X","authenticated-orcid":false,"given":"Edit","family":"Ormai","sequence":"additional","affiliation":[{"name":"Department of Pharmacognosy, Faculty of Pharmacy, University of P\u00e9cs, 7624 P\u00e9cs, Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lilla","family":"Radv\u00e1nyi","sequence":"additional","affiliation":[{"name":"Department of Pharmacognosy, Faculty of Pharmacy, University of P\u00e9cs, 7624 P\u00e9cs, Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"B\u00e9la","family":"Kocsis","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology, Medical School, University of P\u00e9cs, 7624 P\u00e9cs, Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Erika","family":"Kerekes","sequence":"additional","affiliation":[{"name":"Department of Biotechnology and Microbiology, Faculty of Science and Informatics, University of Szeged, 6726 Szeged, Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1779-6370","authenticated-orcid":false,"given":"Marianna","family":"Kocsis","sequence":"additional","affiliation":[{"name":"Department of Agricultural Biology, Institute of Biology, University of P\u00e9cs, 7624 P\u00e9cs, Hungary"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1177\/01410768251328997","article-title":"Antibiotics for Common Infections in Primary Care before, during and after the COVID-19 Pandemic: Cohort Study of Extent of Prescribing Based on Risks of Infection-Related Hospital Admissions","volume":"118","author":"Fahmi","year":"2025","journal-title":"J. R. Soc. Med."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Fahmi, A., Palin, V., Zhong, X., Yang, Y.-T., Watts, S., Ashcroft, D.M., Goldacre, B., MacKenna, B., Fisher, L., and Massey, J. (2024). Evaluation of the Impact of COVID-19 Pandemic on Hospital Admission Related to Common Infections: Risk Prediction Models to Tackle Antimicrobial Resistance in Primary Care. PLoS ONE, 19.","DOI":"10.1371\/journal.pone.0311515"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"240029","DOI":"10.1183\/16000617.0029-2024","article-title":"Phage Therapy: Breathing New Tactics into Lower Respiratory Tract Infection Treatments","volume":"33","author":"Vaezi","year":"2024","journal-title":"Eur. Respir. Rev."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Miriti, D.M., Muthini, J.M., and Nyamache, A.K. (2023). Study of Bacterial Respiratory Infections and Antimicrobial Susceptibility Profile among Antibiotics Naive Outpatients Visiting Meru Teaching and Referral Hospital, Meru County, Kenya in 2018. BMC Microbiol., 23.","DOI":"10.1186\/s12866-023-02905-x"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"\u00c1ngy\u00e1n, V.D., Bal\u00e1zs, V.L., Kocsis, M., Kocsis, B., Horv\u00e1th, G., Farkas, \u00c1., and Nagy-Radv\u00e1nyi, L. (2025). Synergistic Antibiofilm Effects of Chestnut and Linden Honey with Lavender Essential Oil Against Multidrug-Resistant Otitis Media Pathogens. Antibiotics, 14.","DOI":"10.3390\/antibiotics14020146"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"S1413","DOI":"10.1093\/ofid\/ofaf519","article-title":"Current Evidence and Gaps for Outpatient Respiratory Tract Infection Diagnostics: A Call to Action","volume":"12","author":"Arena","year":"2025","journal-title":"Open Forum Infect. Dis."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"dlaf028","DOI":"10.1093\/jacamr\/dlaf028","article-title":"Duration of Antibiotic Treatment for Respiratory Tract Infections in Primary Care","volume":"7","author":"Llor","year":"2025","journal-title":"JAC Antimicrob. Resist."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"469","DOI":"10.1080\/10412905.2025.2595097","article-title":"Anti-Biofilm Activity of Tea Tree, Peppermint, Clove, Thyme Essential Oils and the Combination of the Most Effective Oils with Antibiotics against Bacteria Associated with Nosocomial Infections","volume":"37","author":"Ormai","year":"2025","journal-title":"J. Essent. Oil Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"675","DOI":"10.5152\/balkanmedj.2016.150116","article-title":"Microbiological Features of Upper Respiratory Tract Infections in Bulgarian Children for the Period 1998-2014","volume":"33","author":"Gergova","year":"2016","journal-title":"Balk. Med. J."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1136","DOI":"10.1016\/S1473-3099(14)70828-X","article-title":"Emerging Novel and Antimicrobial-Resistant Respiratory Tract Infections: New Drug Development and Therapeutic Options","volume":"14","author":"Zumla","year":"2014","journal-title":"Lancet Infect. Dis."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Noviello, S., and Huang, D.B. (2019). The Basics and the Advancements in Diagnosis of Bacterial Lower Respiratory Tract Infections. Diagnostics, 9.","DOI":"10.3390\/diagnostics9020037"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Yin, R., Cheng, J., Wang, J., Li, P., and Lin, J. (2022). Treatment of Pseudomonas aeruginosa Infectious Biofilms: Challenges and Strategies. Front. Microbiol., 13.","DOI":"10.3389\/fmicb.2022.955286"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Yeu, J.-E., Lee, H.-G., Park, G.-Y., Lee, J., and Kang, M.-S. (2021). Antimicrobial and Antibiofilm Activities of Weissella cibaria against Pathogens of Upper Respiratory Tract Infections. Microorganisms, 9.","DOI":"10.3390\/microorganisms9061181"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"S68","DOI":"10.1097\/00006454-199808001-00004","article-title":"Clinical Perspectives on Sinusitis and Otitis Media","volume":"17","author":"Blumer","year":"1998","journal-title":"Pediatr. Infect. Dis. J."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Ngo, C.C., Massa, H.M., Thornton, R.B., and Cripps, A.W. (2016). Predominant Bacteria Detected from the Middle Ear Fluid of Children Experiencing Otitis Media: A Systematic Review. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0150949"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Silva, M.D., Lima, A., Mar\u00e7al, N., Dias, L., Gama, M., and Sillankorva, S. (2022). Identification of the Bacterial Pathogens in Children with Otitis Media: A Study in the Northwestern Portuguese District of Braga. Microorganisms, 10.","DOI":"10.3390\/microorganisms10010054"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"121507","DOI":"10.1016\/j.ijpharm.2022.121507","article-title":"Combination and Nanotechnology Based Pharmaceutical Strategies for Combating Respiratory Bacterial Biofilm Infections","volume":"616","author":"Zhang","year":"2022","journal-title":"Int. J. Pharm."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"and Waturangi, D.E. (2023). Antibiofilm Activity from Endophyte Bacteria, Vibrio Cholerae Strains, and Actinomycetes Isolates in Liquid and Solid Culture. BMC Microbiol., 23.","DOI":"10.1186\/s12866-023-02829-6"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2890","DOI":"10.1055\/s-0043-1775498","article-title":"Squaramide Homoserine Lactone Derivatives and Their Abilities to Modulate Pseudomonas aeruginosa Biofilm Formation","volume":"36","author":"Pumirat","year":"2025","journal-title":"Synlett"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"31362","DOI":"10.1021\/acsami.7b04828","article-title":"An Integrated Microsystem for Real-Time Detection and Threshold-Activated Treatment of Bacterial Biofilms","volume":"9","author":"Subramanian","year":"2017","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Gilmore, B.F., McDougald, D., and Beloin, C. (2022). Editorial: Insights in Biofilms: 2021. Front. Cell. Infect. Microbiol., 12.","DOI":"10.3389\/fcimb.2022.1093692"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"668","DOI":"10.1016\/j.tim.2020.03.016","article-title":"Biofilm Matrixome: Extracellular Components in Structured Microbial Communities","volume":"28","author":"Karygianni","year":"2020","journal-title":"Trends Microbiol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"621","DOI":"10.1038\/s41579-022-00682-4","article-title":"Tolerance and Resistance of Microbial Biofilms","volume":"20","author":"Ciofu","year":"2022","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"e0002423","DOI":"10.1128\/cmr.00024-23","article-title":"Biofilm Antimicrobial Susceptibility Testing: Where Are We and Where Could We Be Going?","volume":"36","author":"Coenye","year":"2023","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1038\/s44259-024-00046-3","article-title":"Mechanisms of Antimicrobial Resistance in Biofilms","volume":"2","author":"Liu","year":"2024","journal-title":"npj Antimicrob. Resist."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"428","DOI":"10.1080\/10412905.2025.2550962","article-title":"Efficacy of Lavender Essential Oil against Respiratory Tract Bacteria Is Influenced by Harvesting Time","volume":"37","author":"Ormai","year":"2025","journal-title":"J. Essent. Oil Res."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Filep, R., Nagy, D.U., Ormai, E., Kocsis, B., Szil\u00e1gyi-Utcz\u00e1s, M., Purger, D., and Bal\u00e1zs, V.L. (2026). Geographical Variation in the Chemical Profile and Antimicrobial Activity of Solidago Gigantea Essential Oils. Front. Microbiol., 17.","DOI":"10.3389\/fmicb.2026.1740133"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1","DOI":"10.33073\/pjm-2025-010","article-title":"Harnessing Monoterpenes and Monoterpenoids as Weapons against Antimicrobial Resistance","volume":"74","author":"Kong","year":"2025","journal-title":"Pol. J. Microbiol."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Adegoke, A.A., Stenstr\u00f6m, T.A., and Okoh, A.I. (2017). Stenotrophomonas maltophilia as an Emerging Ubiquitous Pathogen: Looking Beyond Contemporary Antibiotic Therapy. Front. Microbiol., 8.","DOI":"10.3389\/fmicb.2017.02276"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"4057","DOI":"10.1128\/AEM.07499-11","article-title":"Selected Antimicrobial Essential Oils Eradicate Pseudomonas Spp. and Staphylococcus aureus Biofilms","volume":"78","author":"Kavanaugh","year":"2012","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Rao, H., Lai, P., and Gao, Y. (2017). Chemical Composition, Antibacterial Activity, and Synergistic Effects with Conventional Antibiotics and Nitric Oxide Production Inhibitory Activity of Essential Oil from Geophila repens (L.) I.M. Johnst. Molecules, 22.","DOI":"10.3390\/molecules22091561"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Wi\u0144ska, K., M\u0105czka, W., \u0141yczko, J., Grabarczyk, M., Czubaszek, A., and Szumny, A. (2019). Essential Oils as Antimicrobial Agents\u2014Myth or Real Alternative?. Molecules, 24.","DOI":"10.3390\/molecules24112130"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Mahizan, N.A., Yang, S.-K., Moo, C.-L., Song, A.A.-L., Chong, C.-M., Chong, C.-W., Abushelaibi, A., Lim, S.-H.E., and Lai, K.-S. (2019). Terpene Derivatives as a Potential Agent against Antimicrobial Resistance (AMR) Pathogens. Molecules, 24.","DOI":"10.3390\/molecules24142631"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Joshi, R.K., Satyal, P., and Setzer, W.N. (2016). Himalayan Aromatic Medicinal Plants: A Review of Their Ethnopharmacology, Volatile Phytochemistry, and Biological Activities. Medicines, 3.","DOI":"10.3390\/medicines3010006"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Garc\u00eda-Salinas, S., Elizondo-Castillo, H., Arruebo, M., Mendoza, G., and Irusta, S. (2018). Evaluation of the Antimicrobial Activity and Cytotoxicity of Different Components of Natural Origin Present in Essential Oils. Molecules, 23.","DOI":"10.1101\/325639"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Iskandar, K., Ahmed, N., Paudyal, N., Ruiz Alvarez, M.-J., Balasubramani, S.P., Saadeh, D., Ullah Baig, S., Sami, H., Hammoudi Halat, D., and Pavlovi\u0107, N. (2025). Essential Oils as Antimicrobial Agents Against WHO Priority Bacterial Pathogens: A Strategic Review of In Vitro Clinical Efficacy, Innovations and Research Gaps. Antibiotics, 14.","DOI":"10.3390\/antibiotics14121250"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1111\/j.1469-0691.2004.00752.x","article-title":"Clinical and Bacteriological Efficacy of the Ketolide Telithromycin against Isolates of Key Respiratory Pathogens: A Pooled Analysis of Phase III Studies","volume":"10","author":"Low","year":"2004","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"362","DOI":"10.1016\/j.ijid.2004.02.005","article-title":"Comparative in Vitro Activity of a Pharmacokinetically Enhanced Oral Formulation of Amoxicillin\/Clavulanic Acid (2000\/125 Mg Twice Daily) against 9172 Respiratory Isolates Collected Worldwide in 2000","volume":"8","author":"Koeth","year":"2004","journal-title":"Int. J. Infect. Dis."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"882","DOI":"10.1111\/j.1469-0691.2008.02063.x","article-title":"In Vitro Activity of Tigecycline and Occurrence of Tetracycline Resistance Determinants in Isolates from Patients Enrolled in Phase 3 Clinical Trials for Community-Acquired Pneumonia","volume":"14","author":"Bradford","year":"2008","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"S6","DOI":"10.1093\/cid\/ciz395","article-title":"Microbiology and Preclinical Review of Omadacycline","volume":"69","author":"Karlowsky","year":"2019","journal-title":"Clin. Infect. Dis."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"393","DOI":"10.1016\/j.cll.2020.08.001","article-title":"Panels and Syndromic Testing in Clinical Microbiology","volume":"40","author":"McElvania","year":"2020","journal-title":"Clin. Lab. Med."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1186\/1476-0711-12-22","article-title":"New Antibiotics for Bad Bugs: Where Are We?","volume":"12","author":"Bassetti","year":"2013","journal-title":"Ann. Clin. Microbiol. Antimicrob."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"3398","DOI":"10.1128\/AAC.00149-08","article-title":"In Vitro Profiling of Ceftaroline against a Collection of Recent Bacterial Clinical Isolates from across the United States","volume":"52","author":"Ge","year":"2008","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"e0137722","DOI":"10.1128\/aac.01377-22","article-title":"Functional Diversity of Gram-Negative Permeability Barriers Reflected in Antibacterial Activities and Intracellular Accumulation of Antibiotics","volume":"67","author":"Leus","year":"2023","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"593","DOI":"10.1128\/MMBR.67.4.593-656.2003","article-title":"Molecular Basis of Bacterial Outer Membrane Permeability Revisited","volume":"67","author":"Nikaido","year":"2003","journal-title":"Microbiol. Mol. Biol. Rev."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1934578X251328241","DOI":"10.1177\/1934578X251328241","article-title":"Comprehensive Review of the Combined Antimicrobial Activity of Essential Oil Mixtures and Synergism with Conventional Antimicrobials","volume":"20","author":"Soulaimani","year":"2025","journal-title":"Nat. Product. Commun."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Yin, L., Gou, Y., Dai, Y., Wang, T., Gu, K., Tang, T., Hussain, S., Huang, X., He, C., and Liang, X. (2023). Cinnamaldehyde Restores Ceftriaxone Susceptibility against Multidrug-Resistant Salmonella. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms24119288"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"8831322","DOI":"10.1155\/2020\/8831322","article-title":"Novel Antibiotic Combinations of Diverse Subclasses for Effective Suppression of Extensively Drug-Resistant Methicillin-Resistant Staphylococcus aureus (MRSA)","volume":"2020","author":"Nasir","year":"2020","journal-title":"Int. J. Microbiol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"8418287","DOI":"10.1155\/2022\/8418287","article-title":"Antibacterial Activities and Synergistic Interaction of Citrus Essential Oils and Limonene with Gentamicin against Clinically Isolated Methicillin-Resistant Staphylococcus aureus","volume":"2022","author":"Sreepian","year":"2022","journal-title":"Sci. World J."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1186\/s12941-021-00485-0","article-title":"Antibiotic Resistance Modifying Ability of Phytoextracts in Anthrax Biological Agent Bacillus anthracis and Emerging Superbugs: A Review of Synergistic Mechanisms","volume":"20","author":"Dassanayake","year":"2021","journal-title":"Ann. Clin. Microbiol. Antimicrob."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"800","DOI":"10.1055\/a-1891-1119","article-title":"Binary Synergistic Combinations of Lavender and Fennel Essential Oils with Amoxicillin","volume":"89","author":"Demirci","year":"2023","journal-title":"Planta Med."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Saleh, N.M., Ezzat, H., El-Sayyad, G.S., and Zedan, H. (2024). Regulation of Overexpressed Efflux Pump Encoding Genes by Cinnamon Oil and Trimethoprim to Abolish Carbapenem-Resistant Acinetobacter Baumannii Clinical Strains. BMC Microbiol., 24.","DOI":"10.1186\/s12866-024-03194-8"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"449","DOI":"10.1111\/lam.13069","article-title":"Antibacterial Activity of Traditional Spices against Lower Respiratory Tract Pathogens: Combinatorial Effects of Trachyspermum Ammi Essential Oil with Conventional Antibiotics","volume":"67","author":"Trifan","year":"2018","journal-title":"Lett. Appl. Microbiol."},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Shahi, A., Manhas, R., Bhattacharya, S., Rathore, A., Kumar, P., Samanta, J., Sharma, M.K., Mahapa, A., Gupta, P., and Anal, J.M.H. (2024). Synthesis and Antibacterial Potential of Novel Thymol Derivatives against Methicillin-Resistant Staphylococcus aureus and P. Aeruginosa Pathogenic Bacteria. Front. Chem., 12.","DOI":"10.3389\/fchem.2024.1482852"},{"key":"ref_55","first-page":"e62187","article-title":"Antibiotic Efficacy Testing in an Ex Vivo Model of Pseudomonas aeruginosa and Staphylococcus aureus Biofilms in the Cystic Fibrosis Lung","volume":"167","author":"Harrington","year":"2021","journal-title":"J. Vis. Exp."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"578","DOI":"10.1111\/lam.13589","article-title":"Antimicrobial Effects of Melaleuca alternifolia (Tea Tree) Essential Oil against Biofilm-Forming Multidrug-Resistant Cystic Fibrosis-Associated Pseudomonas aeruginosa as a Single Agent and in Combination with Commonly Nebulized Antibiotics","volume":"75","author":"Haines","year":"2022","journal-title":"Lett. Appl. Microbiol."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"9410609","DOI":"10.1155\/2023\/9410609","article-title":"Antibiotic-Potentiating Effect of Some Bioactive Natural Products against Planktonic Cells, Biofilms, and Virulence Factors of Pseudomonas aeruginosa","volume":"2023","author":"Chimi","year":"2023","journal-title":"Biomed. Res. Int."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"2000005","DOI":"10.1002\/adtp.202000005","article-title":"Functionalized Polymers Enhance Permeability of Antibiotics in Gram-Negative MDR Bacteria and Biofilms for Synergistic Antimicrobial Therapy","volume":"3","author":"Gupta","year":"2020","journal-title":"Adv. Ther."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"e00199-24","DOI":"10.1128\/spectrum.00199-24","article-title":"Anti-Biofilm Activities and Antibiotic Synergy of Naturally Occurring Compounds against Drug-Resistant Rapidly Growing Mycobacteria","volume":"12","author":"Huang","year":"2024","journal-title":"Microbiol. Spectr."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"e4872","DOI":"10.7717\/peerj.4872","article-title":"Cytotoxicity and Antimicrobial Action of Selected Phytochemicals against Planktonic and Sessile Streptococcus Mutans","volume":"6","author":"Ribeiro","year":"2018","journal-title":"PeerJ"},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"7274309","DOI":"10.1155\/2023\/7274309","article-title":"Antibiofilm Activity and Synergistic Effects of Thymol-Loaded Poly (Lactic-Co-Glycolic Acid) Nanoparticles with Amikacin against Four Salmonella enterica Serovars","volume":"2023","author":"Boulens","year":"2023","journal-title":"Can. J. Infect. Dis. Med. Microbiol."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"1934578X221136673","DOI":"10.1177\/1934578X221136673","article-title":"Antibacterial and Anti-Inflammatory Potential of Chinese Medicinal Herbs: Lonicerae flos, Lonicerae japonicae flos, Scutellaria baicalensis georgi, and Forsythia suspensa","volume":"17","author":"Ming","year":"2022","journal-title":"Nat. Product. Commun."},{"key":"ref_63","unstructured":"CLSI (2023). Performance Standards for Antimicrobial Disk Susceptibility Tests, Clinical and Laboratory Standards Institute. [14th ed.]. CLSI Standard M02."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1016\/j.archoralbio.2017.12.028","article-title":"Effects of Sub-Minimum Inhibitory Concentrations of Lemon Essential Oil on the Acid Tolerance and Biofilm Formation of Streptococcus mutans","volume":"87","author":"Sun","year":"2018","journal-title":"Arch. Oral. Biol."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1093\/jac\/dkg301","article-title":"Synergy, Antagonism, and What the Chequerboard Puts between Them","volume":"52","author":"Odds","year":"2003","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_66","first-page":"1","article-title":"PAST: Paleontological Statistics Software Package for Education and Data Analysis","volume":"4","author":"Hammer","year":"2001","journal-title":"Palaeontol. Electron."}],"container-title":["Antibiotics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-6382\/15\/4\/403\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,16]],"date-time":"2026-04-16T09:18:15Z","timestamp":1776331095000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-6382\/15\/4\/403"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,16]]},"references-count":66,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2026,4]]}},"alternative-id":["antibiotics15040403"],"URL":"https:\/\/doi.org\/10.3390\/antibiotics15040403","relation":{},"ISSN":["2079-6382"],"issn-type":[{"value":"2079-6382","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,16]]}}}