{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T15:57:44Z","timestamp":1785427064057,"version":"3.56.0"},"reference-count":55,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T00:00:00Z","timestamp":1779408000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006769","name":"RSF","doi-asserted-by":"publisher","award":["25-74-00025"],"award-info":[{"award-number":["25-74-00025"]}],"id":[{"id":"10.13039\/501100006769","id-type":"DOI","asserted-by":"publisher"}]},{"award":["25-74-00025"],"award-info":[{"award-number":["25-74-00025"]}],"id":[{"id":"https:\/\/ror.org\/02yh9se80","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>This pilot study investigated the effects of estradiol and clindamycin on mono- and dual-species biofilms of selected reference and clinical isolates of Lactobacillus gasseri and Cutibacterium acnes, including one vaginal isolate of C. acnes. Our findings demonstrate complex, strain-dependent effects of both compounds and their combinations. Estradiol inhibited biofilm formation in L. gasseri strains but exhibited divergent impacts on C. acnes isolates, stimulating the skin-derived strain while suppressing the vaginal isolate. The observation that pre-adsorbed estradiol tended to enhance its biological activity is consistent with, though does not prove, the hypothesis of a direct hormonal interaction with the bacterial cell envelope. Crucially, estradiol modulated the susceptibility of both species to clindamycin. At the working concentration selected, clindamycin susceptibility varied considerably between strains, with the antibiotic stimulating biofilm growth in skin-derived C. acnes HM514 biofilms. In dual-species communities, an apparent inversion of clindamycin activity was observed, suggesting that estradiol may alter antibiotic efficacy in a manner dependent on community composition and strain identity. Furthermore, while transcriptional changes in bacteriocin genes were evident under hormonal and antibiotic pressure, these shifts did not consistently correlate with observed phenotypic antagonistic activity. These results underscore the limitations of traditional mono-species assays and highlight the importance of considering hormonal background, community context, and the substantial phenotypic variability among individual microbial isolates when evaluating antimicrobial interventions.<\/jats:p>","DOI":"10.3390\/microorganisms14061173","type":"journal-article","created":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T16:06:08Z","timestamp":1779465968000},"page":"1173","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Estradiol-Induced Modulation of Clindamycin Susceptibility in Mono- and Dual-Species Biofilms of Lactobacillus gasseri and Cutibacterium acnes: An In Vitro Model Study"],"prefix":"10.3390","volume":"14","author":[{"given":"Varvara P.","family":"Pavlova","sequence":"first","affiliation":[{"name":"Federal Research Centre \u201cFundamentals of Biotechnology\u201d of Russian Academy of Sciences, Moscow 117312, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Artem G.","family":"Chebotarevskii","sequence":"additional","affiliation":[{"name":"Federal Research Centre \u201cFundamentals of Biotechnology\u201d of Russian Academy of Sciences, Moscow 117312, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ecaterina V.","family":"Diuvenji","sequence":"additional","affiliation":[{"name":"Federal Research Centre \u201cFundamentals of Biotechnology\u201d of Russian Academy of Sciences, Moscow 117312, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nadezhda A.","family":"Loginova","sequence":"additional","affiliation":[{"name":"Federal Research Centre \u201cFundamentals of Biotechnology\u201d of Russian Academy of Sciences, Moscow 117312, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna M.","family":"Mosolova","sequence":"additional","affiliation":[{"name":"Federal Research Centre \u201cFundamentals of Biotechnology\u201d of Russian Academy of Sciences, Moscow 117312, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-6212-4913","authenticated-orcid":false,"given":"Aleksandra S.","family":"Novikova","sequence":"additional","affiliation":[{"name":"Federal Research Centre \u201cFundamentals of Biotechnology\u201d of Russian Academy of Sciences, Moscow 117312, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sergey V.","family":"Martyanov","sequence":"additional","affiliation":[{"name":"Federal Research Centre \u201cFundamentals of Biotechnology\u201d of Russian Academy of Sciences, Moscow 117312, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marina V.","family":"Sukhacheva","sequence":"additional","affiliation":[{"name":"Federal Research Centre \u201cFundamentals of Biotechnology\u201d of Russian Academy of Sciences, Moscow 117312, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexander I.","family":"Netrusov","sequence":"additional","affiliation":[{"name":"Microbiology Department, Lomonosov Moscow State University, Moscow 119234, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrei V.","family":"Gannesen","sequence":"additional","affiliation":[{"name":"Federal Research Centre \u201cFundamentals of Biotechnology\u201d of Russian Academy of Sciences, Moscow 117312, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Kwon, M.S., and Lee, H.K. (2022). Host and microbiota interplay shapes the vaginal microenvironment. Front. Immunol., 13.","DOI":"10.3389\/fimmu.2022.919728"},{"key":"ref_2","first-page":"281","article-title":"Analysis of diversity of vaginal microbiota in healthy Chinese women by using DNA-fingerprinting","volume":"44","author":"Xiao","year":"2012","journal-title":"Beijing Da Xue Xue Bao Yi Xue Ban"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Kazi, Y.F., Saleem, S., and Kazi, N. (2012). Investigation of vaginal microbiota in sexually active women using hormonal contraceptives in Pakistan. BMC Urol., 12.","DOI":"10.1186\/1471-2490-12-22"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2272","DOI":"10.1099\/mic.0.081034-0","article-title":"Differences in vaginal microbiota in African American women versus women of European ancestry","volume":"160","author":"Fettweis","year":"2014","journal-title":"Microbiology"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"e00593-20","DOI":"10.1128\/msphere.00593-20","article-title":"Daily vaginal microbiota fluctuations associated with natural hormonal cycle, contraceptives, diet, and exercise","volume":"5","author":"Song","year":"2020","journal-title":"mSphere"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1899","DOI":"10.1056\/NEJMoa043802","article-title":"Molecular identification of bacteria associated with bacterial vaginosis","volume":"353","author":"Fredricks","year":"2005","journal-title":"N. Engl. J. Med."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Dong, W., Wang, S., Wang, X., Xu, G., Liu, Q., Li, Z., Lv, N., Pan, Y., Xiong, Q., and Liu, D. (2024). Characteristics of vaginal microbiota of women of reproductive age with infections. Microorganisms, 12.","DOI":"10.3390\/microorganisms12051030"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e0107421","DOI":"10.1128\/Spectrum.01074-21","article-title":"The vaginal microbiota of nonhuman primates can be only transiently altered to become Lactobacillus dominant without reducing inflammation","volume":"9","author":"Langner","year":"2021","journal-title":"Microbiol. Spectr."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Chen, Y.C., Chiang, Y.F., Huang, K.C., Wang, K.L., Huang, Y.J., Shieh, T.M., Ali, M., and Hsia, S.M. (2025). the vaginal microbiota: Associations with vaginal pH, menopause and metabolic parameters. Microorganisms, 13.","DOI":"10.3390\/microorganisms13061317"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2201","DOI":"10.1271\/bbb.64.2201","article-title":"Primary amino acid and DNA sequences of gassericin T, a lactacin F-family bacteriocin produced by Lactobacillus gasseri SBT2055","volume":"64","author":"Kawai","year":"2000","journal-title":"Biosci. Biotechnol. Biochem."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Maldonado-Barrag\u00e1n, A., Caballero-Guerrero, B., Mart\u00edn, V., Ruiz-Barba, J.L., and Rodr\u00edguez, J.M. (2016). Purification and genetic characterization of gassericin E, a novel co-culture inducible bacteriocin from Lactobacillus gasseri EV1461 isolated from the vagina of a healthy woman. BMC Microbiol., 16.","DOI":"10.1186\/s12866-016-0663-1"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3869","DOI":"10.1007\/s00253-020-10493-3","article-title":"Production of multiple bacteriocins, including the novel bacteriocin gassericin M, by Lactobacillus gasseri LM19, a strain isolated from human milk","volume":"104","author":"Colquhoun","year":"2020","journal-title":"Appl. Microbiol. Biotechnol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"000539-v3","DOI":"10.1099\/acmi.0.000539.v3","article-title":"A multiphasic approach to solve misidentification of Cutibacterium acnes as Atopobium vaginae during routine bacterial screening of platelet concentrates using the VITEK 2 system","volume":"5","author":"Kumaran","year":"2023","journal-title":"Access Microbiol."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Br\u00fcggemann, H., Salar-Vidal, L., Gollnick, H.P., and Lood, R. (2021). A Janus-faced bacterium: Host-beneficial and-detrimental roles of Cutibacterium acnes. Front. Microbiol., 12.","DOI":"10.3389\/fmicb.2021.673845"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1038\/s41522-016-0004-z","article-title":"Microbial biofilms and the human skin microbiota","volume":"2","author":"Brandwein","year":"2016","journal-title":"NPJ Biofilms Microbiomes"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/j.ijfoodmicro.2011.01.028","article-title":"Identification, typing and characterisation of Propionibacterium strains from healthy mucosa of the human stomach","volume":"149","author":"Delgado","year":"2011","journal-title":"Int. J. Food. Microbiol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2729","DOI":"10.1007\/s43032-025-01869-9","article-title":"Correlation between Lactobacillus of vaginal microbiota and the pregnancy outcomes for patients experiencing recurrent miscarriage","volume":"38","author":"Tan","year":"2025","journal-title":"Reprod. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Valenti, P., Rosa, L., Capobianco, D., Lepanto, M.S., Schiavi, E., Cutone, A., Paesano, R., and Mastromarino, P. (2018). Role of lactobacilli and lactoferrin in the mucosal cervicovaginal defense. Front. Immunol., 9.","DOI":"10.3389\/fimmu.2018.00376"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Suriano, F., Nystr\u00f6m, E.E., Sergi, D., and Gustafsson, J.K. (2022). Diet, microbiota, and the mucus layer: The guardians of our health. Front. Immunol., 13.","DOI":"10.3389\/fimmu.2022.953196"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"821","DOI":"10.1080\/17512433.2021.1917373","article-title":"The effect of different contraceptive methods on the vaginal microbiome","volume":"14","author":"Bastianelli","year":"2021","journal-title":"Expert Rev. Clin. Pharmacol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"7133","DOI":"10.1038\/s41598-021-86628-x","article-title":"Effect of 17\u03b2-estradiol on a human vaginal Lactobacillus crispatus strain","volume":"11","author":"Clabaut","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_22","first-page":"43","article-title":"Progesterone and estradiol alter the growth, virulence and antibiotic susceptibilities of Staphylococcus aureus","volume":"46","year":"2023","journal-title":"New Microbiol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"100537","DOI":"10.1016\/j.coemr.2024.100537","article-title":"How human hormones regulate human microbiota: Where are we in the middle of this terra incognita?","volume":"36","author":"Gannesen","year":"2024","journal-title":"Curr. Opin. Endocr. Metab. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.anaerobe.2014.02.003","article-title":"Effect of estradiol on planktonic growth, coaggregation, and biofilm formation of the Prevotella intermedia group bacteria","volume":"27","author":"Fteita","year":"2014","journal-title":"Anaerobe"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Stensen, D.B., Sm\u00e5brekke, L., Olsen, K., Grimnes, G., Nielsen, C.S., Simonsen, G.S., Sollid, J.U.E., and Furberg, A.S. (2019). Hormonal contraceptive use and Staphylococcus aureus nasal and throat carriage in a Norwegian youth population. PLoS ONE, 14.","DOI":"10.1371\/journal.pone.0218511"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Mosolova, A.M., Loginova, N.A., Diuvenji, E.V., Chebotarevskii, A.G., Sukhacheva, M.V., Tsibulnikov, S.V., Bikmulina, P.Y., Tereshina, V.M., Ianutsevich, E.A., and Danilova, O.A. (2025). Estradiol modulates the sensitivity to vancomycin of Lactobacillus paracasei and Staphylococcus aureus biofilms. Microorganisms, 13.","DOI":"10.3390\/microorganisms13122777"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Kiseleva, A.A., Solovyeva, T.V., Ovcharova, M.A., Geras\u2019kina, O.V., Mart\u2019yanov, S.V., Cherdyntseva, T.A., Danilova, N.D., Zhurina, M.V., Botchkova, E.A., and Feofanov, A.V. (2022). Effect of \u03b2-estradiol on mono-and mixed-species biofilms of human commensal bacteria Lactobacillus paracasei AK508 and Micrococcus luteus C01 on different model surfaces. Coatings, 12.","DOI":"10.3390\/coatings12040436"},{"key":"ref_28","first-page":"21","article-title":"The effect of testosterone and anabolic steroids on the skin surface lipids and the population of Propionibacteria acnes in young postpubertal men","volume":"68","author":"Korvola","year":"1988","journal-title":"Acta Derm. Venereol."},{"key":"ref_29","unstructured":"Plotkin, H.C. (2003). The Imagined World Made Real: Towards a Natural Science of Culture, Rutgers University Press."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"39","DOI":"10.2478\/abmj-2021-0012","article-title":"Hormones can influence antibiotic susceptibilities even in mono-and co-culture conditions","volume":"4","year":"2021","journal-title":"Acta. Biol. Marisiensis"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Diuvenji, E.V., Nevolina, E.D., Solovyev, I.D., Sukhacheva, M.V., Mart\u2019yanov, S.V., Novikova, A.S., Zhurina, M.V., Plakunov, V.K., and Gannesen, A.V. (2023). A-Type natriuretic peptide alters the impact of azithromycin on biofilms of skin bacteria. Microorganisms, 11.","DOI":"10.3390\/microorganisms11122965"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"777","DOI":"10.1134\/S0026261724606560","article-title":"Modulation of azithromycin activity against single-species and binary biofilms of Staphylococcus aureus and Kytococcus schroeteri by norepinephrine","volume":"93","author":"Diuvenji","year":"2024","journal-title":"Microbiology"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Feuillolay, C., Salvatico, S., Escola, J., Quioc-Salomon, B., Carrois, F., and Roques, C. (2025). In vitro bactericidal activity of a neomycin-polymyxin b-nystatin combination. Pharmaceuticals, 18.","DOI":"10.3390\/ph18030340"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"386","DOI":"10.1016\/j.resmic.2007.02.001","article-title":"Biofilm formation by Propionibacterium acnes is associated with increased resistance to antimicrobial agents and increased production of putative virulence factors","volume":"158","author":"Coenye","year":"2007","journal-title":"Res. Microbiol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1007\/s15010-015-0773-y","article-title":"Pharmacokinetic variability of clindamycin and influence of rifampicin on clindamycin concentration in patients with bone and joint infections","volume":"43","author":"Curis","year":"2015","journal-title":"Infection"},{"key":"ref_36","unstructured":"Murphy, P.B., Bistas, K.G., Patel, P., and Le, J.K. (2024). Clindamycin. StatPearls [Internet], StatPearls Publishing."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Merritt, J.H., Kadouri, D.E., and O\u2019Toole, G.A. (2011). Growing and analyzing static biofilms. Curr. Protoc. Microbiol., 22.","DOI":"10.1002\/9780471729259.mc01b01s22"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Ovcharova, M.A., Geraskina, O.V., Danilova, N.D., Botchkova, E.A., Martyanov, S.V., Feofanov, A.V., Plakunov, V.K., and Gannesen, A.V. (2021). Atrial natriuretic peptide affects skin commensal Staphylococcus epidermidis and Cutibacterium acnes dual-species biofilms. Microorganisms, 9.","DOI":"10.3390\/microorganisms9030552"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"100058","DOI":"10.1016\/j.bioflm.2021.100058","article-title":"Epinephrine affects gene expression levels and has a complex effect on biofilm formation in Micrococcus luteus strain C01 isolated from human skin","volume":"3","author":"Gannesen","year":"2021","journal-title":"Biofilm"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"474","DOI":"10.1006\/abbi.1993.1311","article-title":"Characterization of the cellular reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)","volume":"303","author":"Berridge","year":"1993","journal-title":"Arch. Biochem. Biophys."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"509","DOI":"10.1134\/S0026261716040147","article-title":"A universal method for quantitative characterization of growth and metabolic activity of microbial biofilms in static models","volume":"85","author":"Plakunov","year":"2016","journal-title":"Microbiology"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"579","DOI":"10.1007\/s12010-009-8808-4","article-title":"Bioactive secondary metabolites from a new terrestrial Streptomyces sp. TN262","volume":"162","author":"Elleuch","year":"2010","journal-title":"Appl. Biochem. Biotechnol."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Ye, J., Coulouris, G., Zaretskaya, I., Cutcutache, I., Rozen, S., and Madden, T.L. (2012). Primer-BLAST: A tool to design target-specific primers for polymerase chain reaction. BMC Bioinform., 13.","DOI":"10.1186\/1471-2105-13-134"},{"key":"ref_44","unstructured":"Integrated DNA Technologies (2026, January 15). OligoAnalyzer\u2122 Tool. Available online: https:\/\/eu.idtdna.com\/pages\/tools\/oligoanalyzer."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Gannesen, A.V., Ziganshin, R.H., Zdorovenko, E.L., Klimko, A.I., Ianutsevich, E.A., Danilova, O.A., Tereshina, V.M., Gorbachevskii, M.V., Ovcharova, M.A., and Nevolina, E.D. (2022). Epinephrine extensively changes the biofilm matrix composition in Micrococcus luteus C01 isolated from human skin. Front. Microbiol., 13.","DOI":"10.3389\/fmicb.2022.1003942"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"e23","DOI":"10.1016\/S1473-3099(15)00527-7","article-title":"Systematic review of antibiotic resistance in acne: An increasing topical and oral threat","volume":"16","author":"Walsh","year":"2016","journal-title":"Lancet Infect. Dis."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"11533","DOI":"10.1038\/s41598-021-91017-5","article-title":"Variability of the response of human vaginal Lactobacillus crispatus to 17\u03b2-estradiol","volume":"11","author":"Clabaut","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"e01774-20","DOI":"10.1128\/mBio.01774-20","article-title":"Sex steroids induce membrane stress responses and virulence properties in Pseudomonas aeruginosa","volume":"11","author":"Vidaillac","year":"2020","journal-title":"mBio"},{"key":"ref_49","first-page":"654","article-title":"Randomized, double-blind, multicenter study of the polymer-based 17-\u03b2 estradiol-eluting stent for treatment of native coronary artery lesions: Six-month results of the ETHOS I trial","volume":"70","author":"Abizaid","year":"2007","journal-title":"Catheter. Cardiovasc. Interv."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"120977","DOI":"10.1016\/j.envres.2025.120977","article-title":"Interfacial sorption of 17\u03b2-E2 on nano-microplastics: Effects of particle size, functional groups and hydrochemical conditions","volume":"270","author":"Li","year":"2025","journal-title":"Environ. Res."},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Carmina, E., Stanczyk, F.Z., and Lobo, R.A. (2019). Evaluation of hormonal status. Yen and Jaffe\u2019s Reproductive Endocrinology, Elsevier.","DOI":"10.1016\/B978-0-323-47912-7.00034-2"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1480","DOI":"10.1016\/S0002-9378(99)70042-6","article-title":"Serum and tissue hormone levels of vaginally and orally administered estradiol","volume":"180","author":"Tourgeman","year":"1999","journal-title":"Am. J. Obstet. Gynecol."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1016\/S0378-5173(01)00900-0","article-title":"In vitro release properties of etonogestrel and ethinyl estradiol from a contraceptive vaginal ring","volume":"232","author":"Kruft","year":"2002","journal-title":"Int. J. Pharm."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1016\/j.contraception.2004.12.015","article-title":"Serum Nestorone\u00ae and ethinyl estradiol levels, and ovulation inhibition in women using three different dosage combinations of a Nestorone progestogen\u2013ethinyl estradiol contraceptive vaginal ring on a bleeding-signaled regimen","volume":"72","author":"Fraser","year":"2005","journal-title":"Contraception"},{"key":"ref_55","first-page":"556","article-title":"Estradiol absorption from vaginal tablets in postmenopausal women","volume":"99","author":"Notelovitz","year":"2022","journal-title":"Obstet. Gynecol."}],"container-title":["Microorganisms"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2607\/14\/6\/1173\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T16:18:03Z","timestamp":1779466683000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2607\/14\/6\/1173"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,22]]},"references-count":55,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2026,6]]}},"alternative-id":["microorganisms14061173"],"URL":"https:\/\/doi.org\/10.3390\/microorganisms14061173","relation":{},"ISSN":["2076-2607"],"issn-type":[{"value":"2076-2607","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,22]]}}}