{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,20]],"date-time":"2026-01-20T07:46:37Z","timestamp":1768895197186,"version":"3.49.0"},"reference-count":23,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2017,8,2]],"date-time":"2017-08-02T00:00:00Z","timestamp":1501632000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2017,8,2]],"date-time":"2017-08-02T00:00:00Z","timestamp":1501632000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Sci Rep"],"abstract":"<jats:title>Abstract<\/jats:title><jats:p>This study assesses a novel bile solubility test and MALDI-TOF for the differentiation of <jats:italic>Streptococcus pneumoniae<\/jats:italic> from other mitis group streptococci, including differentiation of <jats:italic>S. pneumoniae<\/jats:italic> from <jats:italic>Streptococcus pseudopneumoniae<\/jats:italic>. Eighty-four species verified mitis group isolates were subjected to our bile solubility test (which measures and calculates the differences of absorbance in the test tube containing 10% sodium deoxycholate versus a blank control tube, after incubation for 10\u2009minutes at 36\u2009\u00b0C using a spectrophotometer) and MALDI-TOF MS (both the standard result output and by visual spectra evaluation). Applying a calculated optimal cut-off absorbance-value of 2.1, differentiated <jats:italic>S. pneumoniae<\/jats:italic> from all but one other mitis group streptococci (one <jats:italic>S. mitis<\/jats:italic> isolate generated an OD-value above 2.1). MALDI-TOF score value identification identified correctly 46 <jats:italic>S. pneumoniae<\/jats:italic> and 4 <jats:italic>S. pseudopneumoniae<\/jats:italic> but misidentified 16 other mitis group strains. Visual spectra evaluation correctly identified all <jats:italic>S. pneumoniae<\/jats:italic> and <jats:italic>S. pseudopneumoniae<\/jats:italic> strains but misidentified 13 other mitis group strains. The bile solubility test based on spectrophotometric reading described in this study can differentiate <jats:italic>S. pneumoniae<\/jats:italic> from other <jats:italic>Streptococcus<\/jats:italic> species. Combining the bile solubility test and the MALDI-TOF spectra results provide a correct identification of all <jats:italic>S. pneumoniae<\/jats:italic> and <jats:italic>S. pseudopneumoniae<\/jats:italic> isolates.<\/jats:p>","DOI":"10.1038\/s41598-017-07772-x","type":"journal-article","created":{"date-parts":[[2017,7,27]],"date-time":"2017-07-27T15:02:27Z","timestamp":1501167747000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":25,"title":["Assessment of a novel bile solubility test and MALDI-TOF for the differentiation of Streptococcus pneumoniae from other mitis group streptococci"],"prefix":"10.1038","volume":"7","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7294-4911","authenticated-orcid":false,"given":"Hans-Christian","family":"Slotved","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Richard R.","family":"Facklam","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kurt","family":"Fuursted","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2017,8,2]]},"reference":[{"key":"7772_CR1","first-page":"1159","volume":"63","author":"J Murray","year":"2014","unstructured":"Murray, J. et al. Global invasive bacterial vaccine-preventable diseases surveillance\u20132008-2014. MMWR Morb. Mortal. Wkly. Rep. \n                           63, 1159\u201362 (2014).","journal-title":"MMWR Morb. Mortal. Wkly. Rep."},{"key":"7772_CR2","doi-asserted-by":"publisher","first-page":"881","DOI":"10.1080\/00365540802325914","volume":"40","author":"M Howitz","year":"2008","unstructured":"Howitz, M., Hartvig Christiansen, A., Harboe, Z. B. & M\u00f8lbak, K. Surveillance of bacterial meningitis in children under 2 y of age in Denmark, 1997\u20132006. Scand. J. Infect. Dis. \n                           40, 881\u2013887 (2008).","journal-title":"Scand. J. Infect. Dis."},{"key":"7772_CR3","doi-asserted-by":"publisher","first-page":"264","DOI":"10.1097\/INF.0b013e3182787f89","volume":"32","author":"KL O\u2019Brien","year":"2013","unstructured":"O\u2019Brien, K. L. PCV13 impact evaluations: the obvious and the unpredicted. Pediatr. Infect. Dis. J. \n                           32, 264\u2013265 (2013).","journal-title":"Pediatr. Infect. Dis. J."},{"key":"7772_CR4","doi-asserted-by":"publisher","first-page":"1861","DOI":"10.1128\/JCM.03069-12","volume":"51","author":"D Dubois","year":"2013","unstructured":"Dubois, D., Segonds, C., Prere, M. F., Marty, N. & Oswald, E. Identification of clinical Streptococcus pneumoniae isolates among other alpha and nonhemolytic streptococci by use of the Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry system. J. Clin. Microbiol. \n                           51, 1861\u20131867 (2013).","journal-title":"J. Clin. Microbiol."},{"key":"7772_CR5","doi-asserted-by":"publisher","first-page":"1171","DOI":"10.1128\/JCM.06609-11","volume":"50","author":"E Wessels","year":"2012","unstructured":"Wessels, E., Schelfaut, J. J., Bernards, A. T. & Claas, E. C. Evaluation of several biochemical and molecular techniques for identification of Streptococcus pneumoniae and Streptococcus pseudopneumoniae and their detection in respiratory samples. J. Clin. Microbiol. \n                           50, 1171\u20131177 (2012).","journal-title":"J. Clin. Microbiol."},{"key":"7772_CR6","doi-asserted-by":"publisher","first-page":"165","DOI":"10.1016\/j.vaccine.2013.08.062","volume":"32","author":"C Satzke","year":"2014","unstructured":"Satzke, C. et al. Standard method for detecting upper respiratory carriage of Streptococcus pneumoniae: updated recommendations from the World Health Organization Pneumococcal Carriage Working Group. Vaccine \n                           32, 165\u2013179 (2014).","journal-title":"Vaccine"},{"key":"7772_CR7","doi-asserted-by":"publisher","first-page":"2863","DOI":"10.1128\/JCM.00508-12","volume":"50","author":"AM Werno","year":"2012","unstructured":"Werno, A. M., Christner, M., Anderson, T. P. & Murdoch, D. R. Differentiation of Streptococcus pneumoniae from nonpneumococcal streptococci of the Streptococcus mitis group by matrix-assisted laser desorption ionization-time of flight mass spectrometry. J. Clin. Microbiol. \n                           50, 2863\u20132867 (2012).","journal-title":"J. Clin. Microbiol."},{"key":"7772_CR8","doi-asserted-by":"publisher","unstructured":"Satzke, C. et al. A Multi-Centre Comparative Study to Identify the Best Serotyping Methods for Examining Pneumococcal Carriage in Vaccine Evaluation Studies. PLoS. Med. 12, 10.1371\/journal.pmed.1001903 (2015).","DOI":"10.1371\/journal.pmed.1001903"},{"key":"7772_CR9","doi-asserted-by":"publisher","first-page":"141","DOI":"10.1016\/j.diagmicrobio.2016.03.018","volume":"85","author":"S Sim\u00f5es Alexandra","year":"2016","unstructured":"Sim\u00f5es Alexandra, S. et al. lytA-based identification methods can misidentify Streptococcus pneumoniae. Diagn. Microbiol. Infect. Dis. \n                           85, 141\u2013148 (2016).","journal-title":"Diagn. Microbiol. Infect. Dis."},{"key":"7772_CR10","doi-asserted-by":"crossref","unstructured":"Jauneikaite, E. et al. Current methods for capsular typing of Streptococcus pneumoniae. J. Microbiol. Methods. 113, 41\u201349. Review (2015).","DOI":"10.1016\/j.mimet.2015.03.006"},{"key":"7772_CR11","doi-asserted-by":"publisher","first-page":"914","DOI":"10.1128\/JCM.01990-16","volume":"55","author":"I Harju","year":"2017","unstructured":"Harju, I. et al. Improved Differentiation of Streptococcus pneumoniae and Other S. mitis group Streptococci by MALDI Biotyper Using an Improved MALDI Biotyper Database Content and a Novel Result Interpretation Algorithm. J. Clin. Microbiol. \n                           55, 914\u2013922 (2017).","journal-title":"J. Clin. Microbiol."},{"key":"7772_CR12","doi-asserted-by":"publisher","first-page":"e2683","DOI":"10.1371\/journal.pone.0002683","volume":"3","author":"M Kilian","year":"2008","unstructured":"Kilian, M. et al. Evolution of Streptococcus pneumoniae and its close commensal relatives. PLoS. ONE. \n                           3, e2683, doi:10.1371\/journal.pone.0002683 (2008).","journal-title":"PLoS. ONE."},{"key":"7772_CR13","doi-asserted-by":"publisher","first-page":"e97825","DOI":"10.1371\/journal.pone.0097825","volume":"15","author":"IH Park","year":"2014","unstructured":"Park, I. H., Geno, K. A., Sherwood, L. K., Nahm, M. H. & Beall, B. Population-based analysis of invasive nontypeable pneumococci reveals that most have defective capsule synthesis genes. PLoS. One. \n                           15, e97825, doi:10.1371\/journal.pone.0097825 (2014).","journal-title":"PLoS. One."},{"key":"7772_CR14","doi-asserted-by":"publisher","unstructured":"Bishop, C.J. et al. Assigning strains to bacterial species via the internet. BMC. Biol. 26, 10.1186\/1741-7007-7-3 (2009).","DOI":"10.1186\/1741-7007-7-3"},{"key":"7772_CR15","doi-asserted-by":"publisher","first-page":"1968","DOI":"10.1128\/JCM.00365-12","volume":"50","author":"CF Scholz","year":"2012","unstructured":"Scholz, C. F., Poulsen, K. & Kilian, M. Novel molecular method for identification of Streptococcus pneumoniae applicable to clinical microbiology and 16S rRNA sequence-based microbiome studies. J. Clin. Microbiol. \n                           50, 1968\u201373 (2012).","journal-title":"J. Clin. Microbiol."},{"key":"7772_CR16","doi-asserted-by":"publisher","unstructured":"Bentley, S. D. et al. Genetic analysis of the capsular biosynthetic locus from all 90 pneumococcal serotypes. PLoS. Genet. 2, 10.1371\/journal.pgen.0020031 (2006).","DOI":"10.1371\/journal.pgen.0020031"},{"key":"7772_CR17","doi-asserted-by":"publisher","unstructured":"Robin, X. et al. pROC: an open-source package for R and S+ to analyze and compare ROC curves. BMC. Bioinformatics. 12, 10.1186\/1471-2105-12-77 (2011).","DOI":"10.1186\/1471-2105-12-77"},{"key":"7772_CR18","doi-asserted-by":"publisher","first-page":"769","DOI":"10.1016\/j.vaccine.2015.12.056","volume":"34","author":"HC Slotved","year":"2016","unstructured":"Slotved, H. C., Dalby, T. & Hoffmann, S. The effect of pneumococcal conjugate vaccines on the incidence of invasive pneumococcal disease caused by ten non-vaccine serotypes in Denmark. Vaccine \n                           34, 769\u2013774 (2016).","journal-title":"Vaccine"},{"key":"7772_CR19","doi-asserted-by":"publisher","first-page":"4686","DOI":"10.1128\/JCM.42.10.4686-4696.2004","volume":"42","author":"JC Arbique","year":"2004","unstructured":"Arbique, J. C. et al. Accuracy of phenotypic and genotypic testing for identification of Streptococcus pneumoniae and description of Streptococcus pseudopneumoniae sp. nov. J. Clin. Microbiol. \n                           42, 4686\u20134696 (2004).","journal-title":"J. Clin. Microbiol."},{"key":"7772_CR20","doi-asserted-by":"publisher","first-page":"2184","DOI":"10.1128\/JCM.00461-08","volume":"46","author":"SS Richter","year":"2008","unstructured":"Richter, S. S. et al. Accuracy of phenotypic methods for identification of Streptococcus pneumoniae isolates included in surveillance programs. J. Clin. Microbiol. \n                           46, 2184\u20132188 (2008).","journal-title":"J. Clin. Microbiol."},{"key":"7772_CR21","doi-asserted-by":"publisher","first-page":"43","DOI":"10.2217\/fmb.15.124","volume":"11","author":"RY Yahiaoui","year":"2016","unstructured":"Yahiaoui, R. Y., den Heijer, C. D., Wolfs, P., Bruggeman, C. A. & Stobberingh, E. E. Evaluation of phenotypic and molecular methods for identification of Streptococcus pneumoniae. Future Microbiol. \n                           11, 43\u201350 (2016).","journal-title":"Future Microbiol."},{"key":"7772_CR22","doi-asserted-by":"publisher","first-page":"9","DOI":"10.1016\/j.diagmicrobio.2016.01.012","volume":"85","author":"J van Prehn","year":"2016","unstructured":"van Prehn, J., van Veen, S. Q., Schelfaut, J. J. & Wessels, E. MALDI-TOF mass spectrometry for differentiation between Streptococcus pneumoniae and Streptococcus pseudopneumoniae. Diagn. Microbiol. Infect. Dis. \n                           85, 9\u201311 (2016).","journal-title":"Diagn. Microbiol. Infect. Dis."},{"key":"7772_CR23","doi-asserted-by":"publisher","first-page":"e0120502","DOI":"10.1371\/journal.pone.0120502","volume":"10","author":"S Angeletti","year":"2015","unstructured":"Angeletti, S. et al. Viridans Group Streptococci clinical isolates: MALDI-TOF mass spectrometry versus gene sequence-based identification. PLoS. One. \n                           10, e0120502, doi:10.1371\/journal.pone.0120502 (2015).","journal-title":"PLoS. One."}],"container-title":["Scientific Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.nature.com\/articles\/s41598-017-07772-x","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-017-07772-x.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-017-07772-x.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,12,23]],"date-time":"2022-12-23T07:49:41Z","timestamp":1671781781000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.nature.com\/articles\/s41598-017-07772-x"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,8,2]]},"references-count":23,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2017,12]]}},"alternative-id":["7772"],"URL":"https:\/\/doi.org\/10.1038\/s41598-017-07772-x","relation":{},"ISSN":["2045-2322"],"issn-type":[{"value":"2045-2322","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,8,2]]},"assertion":[{"value":"27 April 2017","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"3 July 2017","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"2 August 2017","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"The authors declare that they have no competing interests.","order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing Interests"}}],"article-number":"7167"}}