{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T07:00:53Z","timestamp":1792047653172,"version":"4.4.0"},"reference-count":54,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2021,8,26]],"date-time":"2021-08-26T00:00:00Z","timestamp":1629936000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Association for Dental Infection Control, Ch\u00e9serex, Switzerland.","award":["no number"],"award-info":[{"award-number":["no number"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>Natural products are being discussed as alternatives to commonly used chemicals in antimicrobial therapy. The study aimed to investigate the antimicrobial activity of propolis against microbial species associated with caries, periodontal disease, and Candida infections. Two commercially available ethanolic extracts of Brazilian and one of European propolis (EEP) were used. The minimal inhibitory concentrations (MIC) of propolis and controls against eight microbial strains were determined. Scanning and transmission electron microscopy (SEM and TEM) images visualized the effect of propolis on microorganisms. Subsequently, the activity on three different multi-species biofilms (both formation and existing biofilms) was assessed. All MIC values of the Brazilian EEPs were low against the tested oral species (\u22640.1 mg\/mL\u20133.13 mg\/mL propolis (Candida albicans)). The European EEP had slightly higher MICs than the Brazilian EEPs. The SEM and TEM images suggest an interaction of propolis with the microbial cell wall. The European EEP exhibited the strongest effect on retarding biofilm formation, whereas the Brazilian EEPs were highly active against preformed biofilms (100 mg\/mL propolis of both EEPs reduced colony forming unit counts always by more than 6 log10). The antimicrobial and anti-biofilm activities point to the potential of propolis as an adjunct in oral health care products.<\/jats:p>","DOI":"10.3390\/antibiotics10091045","type":"journal-article","created":{"date-parts":[[2021,8,27]],"date-time":"2021-08-27T09:53:23Z","timestamp":1630058003000},"page":"1045","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":38,"title":["In Vitro Activity of Propolis on Oral Microorganisms and Biofilms"],"prefix":"10.3390","volume":"10","author":[{"given":"Alexandra","family":"St\u00e4hli","sequence":"first","affiliation":[{"name":"Department of Periodontology, School of Dental Medicine, University of Bern, 3010 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hannah","family":"Schr\u00f6ter","sequence":"additional","affiliation":[{"name":"Department of Periodontology, School of Dental Medicine, University of Bern, 3010 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Simonetta","family":"Bullitta","sequence":"additional","affiliation":[{"name":"C.N.R., Institute for Animal Production System in Mediterranean Environment (ISPAAM), Traversa La Crucca 3, Localit\u00e0 Baldinca, 07100 Sassari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Francesca","family":"Serralutzu","sequence":"additional","affiliation":[{"name":"C.N.R., Institute for Animal Production System in Mediterranean Environment (ISPAAM), Traversa La Crucca 3, Localit\u00e0 Baldinca, 07100 Sassari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonio","family":"Dore","sequence":"additional","affiliation":[{"name":"C.N.R., Institute of Sciences of Food Production (ISPA), Traversa La Crucca 3, Localit\u00e0 Baldinca, 07100 Sassari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sandor","family":"Nietzsche","sequence":"additional","affiliation":[{"name":"Center for Electron Microscopy, Jena University Hospital, 07743 Jena, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4272-0538","authenticated-orcid":false,"given":"Egle","family":"Milia","sequence":"additional","affiliation":[{"name":"Department of Medicine, Surgery and Experimental Sciences, University of Sassari, 07100 Sassari, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2836-5477","authenticated-orcid":false,"given":"Anton","family":"Sculean","sequence":"additional","affiliation":[{"name":"Department of Periodontology, School of Dental Medicine, University of Bern, 3010 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4619-2461","authenticated-orcid":false,"given":"Sigrun","family":"Eick","sequence":"additional","affiliation":[{"name":"Department of Periodontology, School of Dental Medicine, University of Bern, 3010 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,8,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1159\/000345367","article-title":"Dental caries from a molecular microbiological perspective","volume":"47","author":"Nyvad","year":"2013","journal-title":"Caries Res."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"S68","DOI":"10.1111\/jcpe.12940","article-title":"Periodontal health and gingival diseases and conditions on an intact and a reduced periodontium: Consensus report of workgroup 1 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions","volume":"45","author":"Chapple","year":"2018","journal-title":"J. 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