{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T06:33:25Z","timestamp":1789713205261,"version":"4.0.1"},"reference-count":48,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2017,6,8]],"date-time":"2017-06-08T00:00:00Z","timestamp":1496880000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Marine Biotechnology Program","award":["20150220"],"award-info":[{"award-number":["20150220"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Marine Drugs"],"abstract":"<jats:p>The object of this study was to discover an alternative therapeutic agent with fewer side effects against acne vulgaris, one of the most common skin diseases. Acne vulgaris is often associated with acne-related bacteria such as Propionibacterium acnes, Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa. Some of these bacteria exhibit a resistance against commercial antibiotics that have been used in the treatment of acne vulgaris (tetracycline, erythromycin, and lincomycin). In the current study, we tested in vitro antibacterial effect of chitosan-phytochemical conjugates on acne-related bacteria. Three chitosan-phytochemical conjugates used in this study exhibited stronger antibacterial activity than that of chitosan (unmodified control). Chitosan-caffeic acid conjugate (CCA) showed the highest antibacterial effect on acne-related bacteria along with minimum inhibitory concentration (MIC; 8 to 256 \u03bcg\/mL). Additionally, the MIC values of antibiotics against antibiotic-resistant P. acnes and P. aeruginosa strains were dramatically reduced in combination with CCA, suggesting that CCA would restore the antibacterial activity of the antibiotics. The analysis of fractional inhibitory concentration (FIC) indices clearly revealed a synergistic antibacterial effect of CCA with antibiotics. Thus, the median sum of FIC (\u2211FIC) values against the antibiotic-resistant bacterial strains ranged from 0.375 to 0.533 in the combination mode of CCA and antibiotics. The results of the present study suggested a potential possibility of chitosan-phytochemical conjugates in the control of infections related to acne vulgaris.<\/jats:p>","DOI":"10.3390\/md15060167","type":"journal-article","created":{"date-parts":[[2017,6,8]],"date-time":"2017-06-08T10:26:09Z","timestamp":1496917569000},"page":"167","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":63,"title":["Synergistic Antibacterial Effects of Chitosan-Caffeic Acid Conjugate against Antibiotic-Resistant Acne-Related Bacteria"],"prefix":"10.3390","volume":"15","author":[{"given":"Ji-Hoon","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Food Science and Technology, Pukyong National University, Busan 48547, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daeung","family":"Yu","sequence":"additional","affiliation":[{"name":"Department of Chemical and Biological Engineering, University of Saskatchewan, Saskatoon, SK S7N 5C5, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sung-Hwan","family":"Eom","sequence":"additional","affiliation":[{"name":"Korea Food Research Institute, Sungnam 13539, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Song-Hee","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Food Science and Technology, Pukyong National University, Busan 48547, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5837-0958","authenticated-orcid":false,"given":"Junghwan","family":"Oh","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Pukyong National University, Busan 48513, Korea"},{"name":"Marine-Integrated Bionics Research Center, Pukyong National University, Busan 48513, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1615-750X","authenticated-orcid":false,"given":"Won\u2010Kyo","family":"Jung","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Pukyong National University, Busan 48513, Korea"},{"name":"Marine-Integrated Bionics Research Center, Pukyong National University, Busan 48513, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2465-8013","authenticated-orcid":false,"given":"Young-Mog","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Food Science and Technology, Pukyong National University, Busan 48547, Korea"},{"name":"Marine-Integrated Bionics Research Center, Pukyong National University, Busan 48513, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2017,6,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"211","DOI":"10.2165\/00128071-200405040-00001","article-title":"Phototherapy in the treatment of acne vulgaris","volume":"5","author":"Charakida","year":"2004","journal-title":"Am. 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