{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T17:10:47Z","timestamp":1785431447834,"version":"3.56.0"},"reference-count":37,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2026,6,30]],"date-time":"2026-06-30T00:00:00Z","timestamp":1782777600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006769","name":"Russian Science Foundation","doi-asserted-by":"publisher","award":["24-15-00002"],"award-info":[{"award-number":["24-15-00002"]}],"id":[{"id":"10.13039\/501100006769","id-type":"DOI","asserted-by":"publisher"}]},{"award":["24-15-00002"],"award-info":[{"award-number":["24-15-00002"]}],"id":[{"id":"https:\/\/ror.org\/03y2gwe85","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Acinetobacter baumannii, a multidrug-resistant pathogen of critical priority within the ESKAPE group, poses a significant threat to global healthcare, particularly in the context of nosocomial infections. Its pathogenesis is mediated not only by antibiotic resistance determinants but also by a complex repertoire of secreted virulence factors. However, comprehensive characterization of the A. baumannii secretome remains methodologically challenging due to spectral overlap in complex biological matrices. In this study, we applied a hybrid approach integrating size-exclusion chromatography with Raman spectroscopy to deconvolute the cell-free supernatant of A. baumannii. Chromatographic fractionation into seven fractions reduced spectral complexity and enabled the identification of unique metabolic profiles. Fraction 3 exhibited a distinct composition, containing specific markers for phosphatidylserine (~1724 cm\u22121), cysteine, phosphatidylinositol, and DNA (~770\u2013806 cm\u22121), as well as CH2 groups of lipids and amino acids (~1450\u20131456 cm\u22121), while lacking signals corresponding to methionine-containing compounds, nucleic acid backbones, and polypeptide backbones characteristic of other fractions. Analysis revealed distinct biochemical specialization across fractions: Fraction 2 was enriched in glutamine\/asparagine-associated signals (~990, ~998 cm\u22121), Fraction 4 contained a unique carotenoid marker (~1154 cm\u22121), Fraction 6 exhibited a phenylalanine-specific peak (~1104 cm\u22121), and Fraction 7 demonstrated the highest intensity of cysteine-containing protein, nucleotide, and phospholipid signals. These findings open new avenues for the discovery of biomarkers associated with virulence and antibiotic resistance in A. baumannii.<\/jats:p>","DOI":"10.3390\/ijms27135904","type":"journal-article","created":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T00:50:37Z","timestamp":1782867037000},"page":"5904","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Characterization of the Acinetobacter baumannii Secretome Using Size-Exclusion Chromatography and Raman Spectroscopy"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3034-8262","authenticated-orcid":false,"given":"Elizaveta Alekseevna","family":"Denisova","sequence":"first","affiliation":[{"name":"Saint-Petersburg Pasteur Institute, St. Petersburg 197101, Russia"},{"name":"Research Institute of Obstetrics and Gynecology Named After D.O. Ott, St. Petersburg 199034, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anastasia","family":"Avdyusheva","sequence":"additional","affiliation":[{"name":"Research Institute of Obstetrics and Gynecology Named After D.O. Ott, St. Petersburg 199034, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6051-9048","authenticated-orcid":false,"given":"Elizaveta","family":"Tyshchuk","sequence":"additional","affiliation":[{"name":"Saint-Petersburg Pasteur Institute, St. Petersburg 197101, Russia"},{"name":"Research Institute of Obstetrics and Gynecology Named After D.O. Ott, St. Petersburg 199034, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5229-9732","authenticated-orcid":false,"given":"Polina","family":"Grebenkina","sequence":"additional","affiliation":[{"name":"Saint-Petersburg Pasteur Institute, St. Petersburg 197101, Russia"},{"name":"Research Institute of Obstetrics and Gynecology Named After D.O. Ott, St. Petersburg 199034, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0365-8532","authenticated-orcid":false,"given":"Andrey","family":"Korenevsky","sequence":"additional","affiliation":[{"name":"Saint-Petersburg Pasteur Institute, St. Petersburg 197101, Russia"},{"name":"Research Institute of Obstetrics and Gynecology Named After D.O. Ott, St. Petersburg 199034, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3873-4133","authenticated-orcid":false,"given":"Ivan","family":"Chelibanov","sequence":"additional","affiliation":[{"name":"Saint-Petersburg Pasteur Institute, St. Petersburg 197101, Russia"},{"name":"\u00abOPTEC\u00bb Joint Stock Company, St. Petersburg 199178, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4493-4855","authenticated-orcid":false,"given":"Vladimir","family":"Chelibanov","sequence":"additional","affiliation":[{"name":"\u00abOPTEC\u00bb Joint Stock Company, St. Petersburg 199178, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4571-8799","authenticated-orcid":false,"given":"Areg","family":"Totolian","sequence":"additional","affiliation":[{"name":"Saint-Petersburg Pasteur Institute, St. Petersburg 197101, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9115-3250","authenticated-orcid":false,"given":"Lyudmila","family":"Kraeva","sequence":"additional","affiliation":[{"name":"Saint-Petersburg Pasteur Institute, St. Petersburg 197101, Russia"},{"name":"Department of Microbiology, Military Medical Academy Named After S.M. Kirov, 6 Akademika Lebedeva Street, Building 6, St. Petersburg 194044, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vitaly","family":"Nazarov","sequence":"additional","affiliation":[{"name":"Department of Faculty Surgery, North-Western State Medical University Named After I. I. Mechnikov, 41 Kirochnaya Street, St. Petersburg 191015, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5749-2531","authenticated-orcid":false,"given":"Dmitry","family":"Sokolov","sequence":"additional","affiliation":[{"name":"Saint-Petersburg Pasteur Institute, St. Petersburg 197101, Russia"},{"name":"Research Institute of Obstetrics and Gynecology Named After D.O. 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