{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,8]],"date-time":"2025-11-08T05:18:53Z","timestamp":1762579133151,"version":"build-2065373602"},"reference-count":44,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T00:00:00Z","timestamp":1762387200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"German Ministry of Education and Research","award":["Nos. 13N15467","13N15720"],"award-info":[{"award-number":["Nos. 13N15467","13N15720"]}]},{"name":"Polish Ministry of Science and Higher Education","award":["No. NZI\/2\/UW.II.14\/N\/21\/21"],"award-info":[{"award-number":["No. NZI\/2\/UW.II.14\/N\/21\/21"]}]},{"DOI":"10.13039\/501100001659","name":"German Research Foundation","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Open Access Publication Fund of the Thueringer Universitaets","award":["Nr. 433052568"],"award-info":[{"award-number":["Nr. 433052568"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Streptococcus pneumoniae is a major opportunistic pathogen and a leading cause of severe infections in infants under two years of age. Human milk oligosaccharides (HMOs), key bioactive components of breast milk, possess immunomodulatory and antimicrobial properties. In this study, the antipneumococcal effects of HMOs are investigated across multiple S. pneumoniae serotypes, focusing on concentration-dependent activity and underlying mechanisms. Growth inhibition and bacterial viability were evaluated using growth curve analysis and colony-forming unit (CFU) assays. HMOs inhibited pneumococcal growth in a concentration-dependent manner, with suppression observed at 1.5\u20132.5 mg\/mL and complete killing at 5 mg\/mL for all serotypes. Nonencapsulated strains were more sensitive, with inhibition at 1 mg\/mL. In the CFU assays, killing occurred at 1.25\u20135 mg\/mL depending on the strain. At physiologically relevant colostrum concentrations (20\u201325 mg\/mL), HMOs achieved complete bactericidal effects across all the tested strains. In contrast, lactose at equivalent doses showed no measurable antimicrobial activity, confirming the specificity of the observed effects. Overall, HMOs exhibit serotype-independent antipneumococcal activity, possibly through interference with bacterial adhesion or metabolic disruption. These findings suggest a potential role for HMOs as adjunctive agents in the prevention of pneumococcal infections in vulnerable populations, such as infants, and warrant further in vivo studies to validate these effects and explore clinical applications.<\/jats:p>","DOI":"10.3390\/ijms262110781","type":"journal-article","created":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T09:02:03Z","timestamp":1762419723000},"page":"10781","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Anti-Pneumococcal Properties of the Native Human Milk Oligosaccharide Fraction: A Concentration-Dependent Study"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4404-1862","authenticated-orcid":false,"given":"Oliwia","family":"Makarewicz","sequence":"first","affiliation":[{"name":"Institute of Infectious Diseases and Infection Control, Jena University Hospital, Friedrich Schiller University Jena, Am Klinikum 1, 07747 Jena, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0281-1208","authenticated-orcid":false,"given":"Tinatini","family":"Tchatchiashvili","sequence":"additional","affiliation":[{"name":"Institute of Infectious Diseases and Infection Control, Jena University Hospital, Friedrich Schiller University Jena, Am Klinikum 1, 07747 Jena, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lisa","family":"Jasef","sequence":"additional","affiliation":[{"name":"Institute of Infectious Diseases and Infection Control, Jena University Hospital, Friedrich Schiller University Jena, Am Klinikum 1, 07747 Jena, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6574-4313","authenticated-orcid":false,"given":"Mark P. G.","family":"van der Linden","sequence":"additional","affiliation":[{"name":"Uniklinik RWTH Aachen, Institute of Medical Microbiology, Referenzlabor f\u00fcr Streptokokken, Pauwelstra\u00dfe 30, 52074 Aachen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9269-3494","authenticated-orcid":false,"given":"Sylwia","family":"Jarzynka","sequence":"additional","affiliation":[{"name":"Department of Medical Biology, Medical University of Warsaw, Litewska 14\/16, 00-575 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4109-0391","authenticated-orcid":false,"given":"Kamila","family":"Strom","sequence":"additional","affiliation":[{"name":"Department of Medical Biology, Medical University of Warsaw, Litewska 14\/16, 00-575 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4192-490X","authenticated-orcid":false,"given":"Nico","family":"Ueberschaar","sequence":"additional","affiliation":[{"name":"Mass Spectrometry Platform, Friedrich Schiller University Jena, Humboldtstra\u00dfe 8, 07743 Jena, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9197-5553","authenticated-orcid":false,"given":"Maciej","family":"Mazur","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7090-6156","authenticated-orcid":false,"given":"Gabriela","family":"Oledzka","sequence":"additional","affiliation":[{"name":"Department of Medical Biology, Medical University of Warsaw, Litewska 14\/16, 00-575 Warsaw, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8157-2753","authenticated-orcid":false,"given":"Mathias W.","family":"Pletz","sequence":"additional","affiliation":[{"name":"Institute of Infectious Diseases and Infection Control, Jena University Hospital, Friedrich Schiller University Jena, Am Klinikum 1, 07747 Jena, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1093\/jac\/dkf506","article-title":"Dynamics of nasopharyngeal colonization by potential respiratory pathogens","volume":"50","year":"2002","journal-title":"J. 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