{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T05:06:06Z","timestamp":1780463166330,"version":"3.54.1"},"reference-count":42,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,5,31]],"date-time":"2026-05-31T00:00:00Z","timestamp":1780185600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100004319","name":"Pfizer","doi-asserted-by":"crossref","award":["69801279"],"award-info":[{"award-number":["69801279"]}],"id":[{"id":"10.13039\/100004319","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background\/Objectives: Following the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in Oman, this study aimed to characterize the genomic epidemiology, serotype distribution, and antimicrobial resistance (AMR) of Streptococcus pneumoniae causing invasive pneumococcal disease (IPD). Methods: All IPD isolates collected through national laboratory-based surveillance between 2018 and 2021 were analyzed using Whole-Genome Sequencing (WGS). Bioinformatics tools determined serotypes, multilocus sequence types (MLSTs), and Global Pneumococcal Sequence Clusters (GPSCs). Clinical correlates and predictors of mortality were assessed via multivariate logistic regression. Results: A total of 129 IPD isolates were included. Serotype 3 (11.6%) was the most prevalent, followed by 23B and 9N (10.8% each), and 8 (8.5%). PCV13 serotypes accounted for only 26.4% of isolates, while PCV20 coverage reached 59.7%. Significant clonal diversity was observed, with GPSC12 (Serotype 3) and GPSC699 (Serotype 9N\/13) being prominent lineages. Multidrug resistance (MDR) was identified in 36.4% of isolates, primarily driven by GPSC6 and GPSC699. The case fatality rate was 23.0%. Advanced age (\u226565 years) and clinical presentation with bacteremia were significant independent predictors of death, whereas bacterial genotype and AMR status were not. Conclusions: The findings demonstrate significant serotype replacement in Oman after the introduction of PCV13. The high prevalence of non-vaccine serotypes and emerging MDR clones justifies the transition to higher-valency vaccines like PCV20. Sustained genomic surveillance remains essential to monitor the evolving landscape of invasive pneumococcal lineages.<\/jats:p>","DOI":"10.3390\/vaccines14060496","type":"journal-article","created":{"date-parts":[[2026,6,2]],"date-time":"2026-06-02T12:45:08Z","timestamp":1780404308000},"page":"496","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Genomic Characterization and Predictors of Mortality in Invasive Streptococcus pneumoniae Disease in Oman: A Four-Year National Genomic Study"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6314-6849","authenticated-orcid":false,"given":"Amina","family":"Al-Jardani","sequence":"first","affiliation":[{"name":"Central Public Health Laboratory, Center for Disease Control and Prevention, Muscat 100, Oman"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Najma","family":"Al-Kharusi","sequence":"additional","affiliation":[{"name":"Central Public Health Laboratory, Center for Disease Control and Prevention, Muscat 100, Oman"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6888-1690","authenticated-orcid":false,"given":"Mohamed","family":"Al-Bulushi","sequence":"additional","affiliation":[{"name":"Central Public Health Laboratory, Center for Disease Control and Prevention, Muscat 100, Oman"},{"name":"Department of Medical Microbiology, University of P\u00e9cs Medical School, 7624 P\u00e9cs, Hungary"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5052-0800","authenticated-orcid":false,"given":"Adil","family":"Al-Wahaibi","sequence":"additional","affiliation":[{"name":"Integrated Surveillance Department, Center for Disease Control and Prevention, Muscat 100, Oman"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Neima","family":"Al-Shekaili","sequence":"additional","affiliation":[{"name":"Central Public Health Laboratory, Center for Disease Control and Prevention, Muscat 100, Oman"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Suad","family":"Al-Fahdi","sequence":"additional","affiliation":[{"name":"Central Public Health Laboratory, Center for Disease Control and Prevention, Muscat 100, Oman"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5251-157X","authenticated-orcid":false,"given":"Rajesh","family":"Kumar","sequence":"additional","affiliation":[{"name":"Association of Public Health Laboratories, Muscat 117, Oman"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2669-6814","authenticated-orcid":false,"given":"Seif","family":"Al-Abri","sequence":"additional","affiliation":[{"name":"Infectious Diseases Unit, Department of Medicine, Royal Hospital, Muscat 111, Oman"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Azza","family":"Al-Rashdi","sequence":"additional","affiliation":[{"name":"Central Public Health Laboratory, Center for Disease Control and Prevention, Muscat 100, Oman"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4881","DOI":"10.1016\/j.vaccine.2013.07.054","article-title":"Serotype Prevalence and Antibiotic Resistance in Streptococcus pneumoniae Clinical Isolates among Global Populations","volume":"31","author":"Hackel","year":"2013","journal-title":"Vaccine"},{"key":"ref_2","unstructured":"Centers for Disease Control and Prevention (2024, March 01). 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