{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T18:46:28Z","timestamp":1792694788515,"version":"4.5.0"},"reference-count":47,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2025,9,12]],"date-time":"2025-09-12T00:00:00Z","timestamp":1757635200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Eikenella corrodens is a facultative anaerobic Gram-negative bacillus, part of the normal oropharyngeal flora, with opportunistic pathogenic potential particularly in immunocompromised hosts. The progression from localized intracranial infections such as cerebritis and subdural empyema to secondary bloodstream infection represents a rare but clinically significant pathway, especially in immuno-compromised patients. Here, we report a case of secondary E. corrodens bacteremia following left temporal cerebritis and ipsilateral subdural empyema in a 50-year-old man with advanced nasopharyngeal carcinoma treated with nivolumab. The patient presented neurological deficits and systemic inflammatory response, suggesting for a bacterial infection. Neuroimaging confirmed the intracranial infectious foci and blood cultures identified E. corrodens via MALDI-TOF MS and 16S rRNA gene sequencing. We discuss how cancer-associated immune dysregulation and immune checkpoint inhibition could modulate host susceptibility and clinical presentation of infection, potentially facilitating microbial dissemination across compromised blood\u2013brain barriers. Additionally, we examine the cases of E. corrodens bacteremia secondary to CNS and head and neck infections. This case underscores the importance of heightened clinical vigilance for secondary bacteremia in oncologic patients with CNS infections and highlights the need for integrated microbiological and radiological assessment to optimize outcomes.<\/jats:p>","DOI":"10.3390\/microorganisms13092135","type":"journal-article","created":{"date-parts":[[2025,9,12]],"date-time":"2025-09-12T09:07:15Z","timestamp":1757668035000},"page":"2135","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Crossing the Barrier: Eikenella corrodens Bacteremia Following CNS Infection in a Patient Treated with Nivolumab\u2014A Case Report and Literature Review"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4025-7882","authenticated-orcid":false,"given":"Terenzio","family":"Cosio","sequence":"first","affiliation":[{"name":"Department of Basic Biotechnological Sciences, Intensive and Perioperative Clinics, Universit\u00e0 Cattolica del Sacro Cuore, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cataldo Maria","family":"Mannavola","sequence":"additional","affiliation":[{"name":"Department of Basic Biotechnological Sciences, Intensive and Perioperative Clinics, Universit\u00e0 Cattolica del Sacro Cuore, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Barbara","family":"Fiori","sequence":"additional","affiliation":[{"name":"Department of Laboratory and Hematological Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matteo","family":"Zelinotti","sequence":"additional","affiliation":[{"name":"Department of Laboratory and Hematological Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0781-3157","authenticated-orcid":false,"given":"Francesco","family":"Taccari","sequence":"additional","affiliation":[{"name":"Infectious Diseases Unit, Department of Medical and Surgical Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1663-7546","authenticated-orcid":false,"given":"Brunella","family":"Posteraro","sequence":"additional","affiliation":[{"name":"Department of Basic Biotechnological Sciences, Intensive and Perioperative Clinics, Universit\u00e0 Cattolica del Sacro Cuore, 00168 Rome, Italy"},{"name":"Department of Laboratory and Hematological Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tiziana","family":"D'Inzeo","sequence":"additional","affiliation":[{"name":"Department of Laboratory and Hematological Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9780-7059","authenticated-orcid":false,"given":"Maurizio","family":"Sanguinetti","sequence":"additional","affiliation":[{"name":"Department of Basic Biotechnological Sciences, Intensive and Perioperative Clinics, Universit\u00e0 Cattolica del Sacro Cuore, 00168 Rome, Italy"},{"name":"Department of Laboratory and Hematological Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e1099","DOI":"10.1002\/hsr2.1099","article-title":"Epidemiological and Clinical Characteristics of Central Nervous System Infections in a Tertiary Center: A Retrospective Study","volume":"6","author":"Gajurel","year":"2023","journal-title":"Health Sci. Rep."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"629","DOI":"10.1128\/microbiolspec.DMIH2-0012-2015","article-title":"Central Nervous System Infections","volume":"4","author":"Zimmer","year":"2016","journal-title":"Microbiol. Spectr."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Archibald, L.K., and Quisling, R.G. (2013). Central Nervous System Infections. Textbook of Neurointensive Care, Springer.","DOI":"10.1007\/978-1-4471-5226-2_22"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1159\/000070776","article-title":"Microbiology and Management of Deep Facial Infections and Lemierre Syndrome","volume":"65","author":"Brook","year":"2003","journal-title":"ORL"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Hu, C.-Y., Lien, K.-H., Chen, S.-L., and Chan, K.-C. (2022). Risk Factors of Descending Necrotizing Mediastinitis in Deep Neck Abscesses. Medicina, 58.","DOI":"10.3390\/medicina58121758"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Bandol, G., Cobzeanu, M.D., Moscalu, M., Palade, O.D., Moisii, L., Severin, F., Patrascanu, E., Mocanu, F., Roman, A.I., and Cobzeanu, B.M. (2025). Deep Neck Infections: The Effectiveness of Therapeutic Management and Bacteriological Profile. Medicina, 61.","DOI":"10.3390\/medicina61010129"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1038\/s41392-024-02043-4","article-title":"Mucosal Immune Response in Biology, Disease Prevention and Treatment","volume":"10","author":"Zhou","year":"2025","journal-title":"Signal Transduct. Target. Ther."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1177\/1941874414540684","article-title":"Bacterial Brain Abscess","volume":"4","author":"Patel","year":"2014","journal-title":"Neurohospitalist"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1424","DOI":"10.1001\/archotol.1989.01860360026011","article-title":"Intracranial Abscesses Secondary to Nasal, Sinus, and Orbital Infections in Adults and Children","volume":"115","author":"Maniglia","year":"1989","journal-title":"Arch. Otolaryngol. Head Neck Surg."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"544","DOI":"10.1093\/cid\/ciad678","article-title":"Brain Abscess Caused by Oral Cavity Bacteria: A Nationwide, Population-Based Cohort Study","volume":"78","author":"Bodilsen","year":"2023","journal-title":"Clin. Infect. Dis."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1053\/j.sult.2019.09.003","article-title":"Intracranial CNS Infections: A Literature Review and Radiology Case Studies","volume":"41","author":"Nguyen","year":"2020","journal-title":"Semin. Ultrasound CT MRI"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"587","DOI":"10.1097\/01.HS9.0000563408.35830.4c","article-title":"PS1282 Infectious Complications of Nivolumab Therapy in Relapsed\/Refractory Hodgkin\u2019s Lymphoma","volume":"3","author":"Rogacheva","year":"2019","journal-title":"HemaSphere"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1002\/cam4.4393","article-title":"Infectious Complications of Immune Checkpoint Inhibitors in Solid Organ Malignancies","volume":"11","author":"Ross","year":"2021","journal-title":"Cancer Medicine"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Oca\u00f1a-Guzm\u00e1n, R., Osorio-P\u00e9rez, D., and Ch\u00e1vez-Gal\u00e1n, L. (2023). Opportunistic Infections and Immune-Related Adverse Events Associated with Administering Immune Checkpoint Inhibitors: A Narrative Review. Pharmaceuticals, 16.","DOI":"10.3390\/ph16081119"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1277","DOI":"10.2169\/internalmedicine.2514-23","article-title":"Cerebral Venous Thrombosis Mimicking Limbic Encephalitis","volume":"63","author":"Tezuka","year":"2024","journal-title":"Intern. Med."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"e24230","DOI":"10.1002\/jcla.24230","article-title":"Eikenella corrodens Infections in Human: Reports of Six Cases and Review of Literatures","volume":"36","author":"Li","year":"2022","journal-title":"J. Clin. Lab. Anal."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1136\/pgmj.54.631.343","article-title":"Recurrent Meningitis and Brain Abscess Caused by Eikenella corrodens","volume":"54","author":"Emmerson","year":"1978","journal-title":"Postgrad. Med. J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1080\/17843286.1992.11718218","article-title":"Intrathoracic Infections with Bacteraemia due to Eikenella corrodens as a Complication of Peritonsillar Abscesses: Report of a Case and Review of the Literature","volume":"47","author":"Zgheib","year":"1992","journal-title":"Acta Clin. Belg."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"466","DOI":"10.1016\/j.kjms.2012.12.009","article-title":"Chronic Meningitis Caused by Eikenella corrodens","volume":"29","author":"Dong","year":"2013","journal-title":"Kaohsiung J. Med. Sci."},{"key":"ref_20","first-page":"686812","article-title":"Eikenella corrodens Sepsis with Cerebrospinal Fluid Pleocytosis in a Very Low Birth Weight Neonate","volume":"2015","author":"Sawyer","year":"2015","journal-title":"Case Rep. Pediatr."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Yamagishi, T., Hikone, M., Sugiyama, K., Tanabe, T., Wada, Y., Furugaito, M., Arai, Y., Uzawa, Y., Mizushima, R., and Kamada, K. (2018). Purpura Fulminans with Lemierre\u2019s Syndrome Caused by Gemella bergeri and Eikenella corrodens: A Case Report. BMC Infect. Dis., 18.","DOI":"10.1186\/s12879-018-3437-6"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1007\/s10096-020-04035-y","article-title":"Epidemiology, Bacteriology, and Clinical Characteristics of HACEK Bacteremia and Endocarditis: A Population-Based Retrospective Study","volume":"40","author":"Berge","year":"2020","journal-title":"Eur. J. Clin. Microbiol. Infect. Dis."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.eimc.2019.04.004","article-title":"Eikenella corrodens Causing Deep-Seated Infections. Six-Year Experience in a University Hospital in Madrid","volume":"38","year":"2020","journal-title":"Enfermedades Infecc. Y Microbiol. Cl\u00ednica"},{"key":"ref_24","first-page":"53","article-title":"The Cerebrospinal Venous System: Anatomy, Physiology, and Clinical Implications","volume":"8","author":"Tobinick","year":"2006","journal-title":"MedGenMed Medscape Gen. Med."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3044","DOI":"10.3390\/curroncol29050247","article-title":"Immune Checkpoint Inhibitors in Cancer Therapy","volume":"29","author":"Shiravand","year":"2022","journal-title":"Curr. Oncol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1007\/s11523-021-00824-3","article-title":"Risk of Infection with Immune Checkpoint Inhibitors: A Systematic Review and Meta-Analysis","volume":"16","author":"Petrelli","year":"2021","journal-title":"Target. Oncol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/j.ijid.2022.04.022","article-title":"Infectious Events in Patients Treated with Immune Checkpoint Inhibitors, Chimeric Antigen Receptor T Cells, and Bispecific T-Cell Engagers: A Review of Registration Studies","volume":"120","author":"Lombardi","year":"2022","journal-title":"Int. J. Infect. Dis."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Wang, X., Wu, Y., Hu, W., and Zhang, J. (2025). Incidence and Risk Factors of Serious Infections Occurred in Patients with Lung Cancer Following Immune Checkpoint Blockade Therapy. BMC Cancer, 25.","DOI":"10.1186\/s12885-025-13743-7"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Cosio, T., Coniglione, F., Flaminio, V., Gaziano, R., Coletta, D., Petruccelli, R., Dika, E., Bianchi, L., and Campione, E. (2023). Pyodermitis during Nivolumab Treatment for Non-Small Cell Lung Cancer: A Case Report and Review of the Literature. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms24054580"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Yin, Q., Wu, L., Han, L., Xiao, Z., Tong, R., Lian, L., Bai, L., and Bian, Y. (2023). Immune-Related Adverse Events of Immune Checkpoint Inhibitors: A Review. Front. Immunol., 14.","DOI":"10.3389\/fimmu.2023.1167975"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.ejca.2020.09.025","article-title":"Infectious Complications in Patients Treated with Immune Checkpoint Inhibitors","volume":"141","author":"Karam","year":"2020","journal-title":"Eur. J. Cancer"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1186\/s13099-025-00722-3","article-title":"Bloodstream Infection by Lactobacillus Rhamnosus in a Haematology Patient: Why Metagenomics Can Make the Difference","volume":"17","author":"Mannavola","year":"2025","journal-title":"Gut Pathog."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Rajasekaran, J.J., Krishnamurthy, H.K., Bosco, J., Jayaraman, V., Krishna, K., Wang, T., and Bei, K. (2024). Oral Microbiome: A Review of Its Impact on Oral and Systemic Health. Microorganisms, 12.","DOI":"10.20944\/preprints202406.1923.v1"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"115221","DOI":"10.1016\/j.ejca.2025.115221","article-title":"Gut Microbiome and Immune Checkpoint Inhibitor Toxicity","volume":"216","author":"Verheijden","year":"2025","journal-title":"Eur. J. Cancer"},{"key":"ref_35","first-page":"690","article-title":"Oral Microbiome Could Provide Clues to CRC","volume":"14","author":"Ray","year":"2017","journal-title":"Nat. Rev. Gastroenterol. Hepatol."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Liu, J., Xu, C., Wang, R., Huang, J., Zhao, R., and Wang, R. (2025). Microbiota and Metabolomic Profiling Coupled with Machine Learning to Identify Biomarkers and Drug Targets in Nasopharyngeal Carcinoma. Front. Pharmacol., 16.","DOI":"10.3389\/fphar.2025.1551411"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"104468","DOI":"10.1016\/j.critrevonc.2024.104468","article-title":"Interconnected Influences of Tumour and Host Microbiota on Treatment Response and Side Effects in Nasopharyngeal Cancer","volume":"202","author":"Sheng","year":"2024","journal-title":"Crit. Rev. Oncol. Hematol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1128\/CMR.00028-08","article-title":"Microbiology of Odontogenic Bacteremia: Beyond Endocarditis","volume":"22","author":"Parahitiyawa","year":"2009","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"418","DOI":"10.1111\/j.1600-051X.2011.01717.x","article-title":"Detection of Specific Periodontal Microorganisms from Bacteraemia Samples after Periodontal Therapy Using Molecular-Based Diagnostics","volume":"38","author":"Castillo","year":"2011","journal-title":"J. Clin. Periodontol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2396","DOI":"10.1158\/2159-8290.CD-21-0236","article-title":"Microbiota-Centered Interventions: The next Breakthrough in Immuno-Oncology?","volume":"11","author":"Derosa","year":"2021","journal-title":"Cancer Discov."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"665","DOI":"10.1128\/JCM.01602-10","article-title":"PCR Diagnosis of Invasive Candidiasis: Systematic Review and Meta-Analysis","volume":"49","author":"Avni","year":"2010","journal-title":"J. Clin. Microbiol."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Jordana-Lluch, E., Gim\u00e9nez, M., Quesada, M.D., Ausina, V., and Martr\u00f3, E. (2014). Improving the Diagnosis of Bloodstream Infections: PCR Coupled with Mass Spectrometry. BioMed Res. Int., 2014.","DOI":"10.1155\/2014\/501214"},{"key":"ref_43","unstructured":"European Committee on Antimicrobial Susceptibility Testing (2025, August 28). Guidance Document: What to Do When There Are No Breakpoints. Eucast. Available online: https:\/\/www.eucast.org\/clinical_breakpoints_and_dosing\/when_there_are_no_breakpoints."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"3253","DOI":"10.1128\/AAC.45.11.3253-3255.2001","article-title":"Susceptibilities of Eikenella corrodens, Prevotella intermedia, and Prevotella nigrescens Clinical Isolates to Amoxicillin and Tetracycline","volume":"45","author":"Luong","year":"2001","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"858","DOI":"10.1128\/CMR.00007-10","article-title":"Penetration of Drugs through the Blood-Cerebrospinal Fluid\/Blood-Brain Barrier for Treatment of Central Nervous System Infections","volume":"23","author":"Nau","year":"2010","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/j.cmi.2023.08.016","article-title":"ESCMID Guidelines on Diagnosis and Treatment of Brain Abscess in Children and Adults","volume":"30","author":"Bodilsen","year":"2023","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"447","DOI":"10.1056\/NEJMra1301635","article-title":"Brain Abscess","volume":"371","author":"Brouwer","year":"2014","journal-title":"N. Engl. J. Med."}],"container-title":["Microorganisms"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2607\/13\/9\/2135\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:44:21Z","timestamp":1760035461000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2607\/13\/9\/2135"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,9,12]]},"references-count":47,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2025,9]]}},"alternative-id":["microorganisms13092135"],"URL":"https:\/\/doi.org\/10.3390\/microorganisms13092135","relation":{},"ISSN":["2076-2607"],"issn-type":[{"value":"2076-2607","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,9,12]]}}}