{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T18:53:12Z","timestamp":1783018392609,"version":"3.54.6"},"reference-count":20,"publisher":"Public Library of Science (PLoS)","issue":"7","license":[{"start":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T00:00:00Z","timestamp":1782950400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001713","name":"European and Developing Countries Clinical Trials Partnership","doi-asserted-by":"publisher","award":["PanACEA-2"],"award-info":[{"award-number":["PanACEA-2"]}],"id":[{"id":"10.13039\/501100001713","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>\n                    Ziehl\u2013Neelsen (ZN) smear microscopy remains central to tuberculosis (TB) diagnosis and treatment monitoring; however, its sensitivity is limited by incomplete recovery of\n                    <jats:italic>Mycobacterium tuberculosis<\/jats:italic>\n                    during pre-analytical processing. This study evaluated whether modifying centrifugation force and duration improves bacillary recovery and ZN smear microscopy performance. Laboratory experiments were conducted using\n                    <jats:italic>M. tuberculosis<\/jats:italic>\n                    H37Rv suspensions and clinical sputum specimens. Following NALC\u2013NaOH treatment, samples were centrifuged at 2,000, 3,000, and 6,000\u2009\u00d7\u2009g for 40 min. The effect of centrifugation duration was assessed at 3,000\u2009\u00d7\u2009g by comparing 20 and 40 min using the same\n                    <jats:italic>M. tuberculosis<\/jats:italic>\n                    H37Rv cultures and the same clinical sputum specimens at both time points, ensuring paired measurements within each sample type. Smear positivity and ZN smear grading were evaluated from replicate smears and analyzed using non-parametric statistical tests, with significance set at\n                    <jats:italic>p<\/jats:italic>\n                    \u2009&lt;\u20090.05. In\n                    <jats:italic>M. tuberculosis<\/jats:italic>\n                    H37Rv suspensions, no significant differences in smear positivity or grading were observed across centrifugal forces (\n                    <jats:italic>p<\/jats:italic>\n                    \u2009=\u20090.368 and\n                    <jats:italic>p<\/jats:italic>\n                    \u2009=\u20090.212, respectively). In clinical sputum specimens, smear positivity did not differ significantly across forces (\n                    <jats:italic>p<\/jats:italic>\n                    \u2009=\u20090.716), whereas ZN smear grading increased significantly with higher centrifugal force (\n                    <jats:italic>p<\/jats:italic>\n                    \u2009=\u20090.0051). At 3,000\u2009\u00d7\u2009g, extending centrifugation time from 20 to 40 min did not significantly affect smear positivity in either sample type (both\n                    <jats:italic>p<\/jats:italic>\n                    \u2009=\u20091.000). In contrast, ZN smear grading increased from 1+ to 2+ in clinical specimens with extended centrifugation time (\n                    <jats:italic>p<\/jats:italic>\n                    \u2009=\u20090.016), while no change was observed in\n                    <jats:italic>M. tuberculosis<\/jats:italic>\n                    H37Rv suspensions. These findings indicate that increasing centrifugal force may enhance bacillary concentration in clinical sputum, resulting in improved smear grading without a corresponding increase in detection rate. Extending centrifugation time has limited impact on smear positivity. Optimization of pre-analytical centrifugation parameters may improve ZN smear microscopy performance in clinical specimens.\n                  <\/jats:p>","DOI":"10.1371\/journal.pone.0342273","type":"journal-article","created":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T17:45:20Z","timestamp":1783014320000},"page":"e0342273","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["A high centrifugal force-enhanced Ziehl\u2013Neelsen method for improved detection of Mycobacterium tuberculosis"],"prefix":"10.1371","volume":"21","author":[{"given":"Godlove T.","family":"Chaula","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lucy","family":"Namkinga","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4742-2791","authenticated-orcid":true,"given":"Wilber","family":"Sabiiti","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nyanda E.","family":"Ntiningya","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bariki","family":"Mtafya","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5586-7088","authenticated-orcid":true,"given":"Ally","family":"Mahadhy","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,7,2]]},"reference":[{"key":"pone.0342273.ref001","unstructured":"World Health Organization (WHO). Global tuberculosis report 2023. Geneva: World Health Organization; 2023. Available from: https:\/\/www.who.int\/teams\/global-programme-on-tuberculosis-and-lung-health\/tb-reports\/global-tuberculosis-report-2023"},{"key":"pone.0342273.ref002","volume-title":"Tuberculosis Diagnostics \u2014 Pipeline Report 2023","author":"D Branigan","year":"2023"},{"key":"pone.0342273.ref003","doi-asserted-by":"crossref","first-page":"992451","DOI":"10.3389\/fmed.2022.992451","article-title":"Systematic assessment of clinical and bacteriological markers for tuberculosis reveals discordance and inaccuracy of symptom-based diagnosis for treatment response monitoring","volume":"9","author":"B Mtafya","year":"2022","journal-title":"Front Med (Lausanne)"},{"key":"pone.0342273.ref004","unstructured":"World Health Organization (WHO). Global tuberculosis report 2024. Geneva: World Health Organization; 2024. Available from: https:\/\/www.who.int\/teams\/global\u2011programme\u2011on\u2011tuberculosis\u2011and\u2011lung\u2011health\/tb\u2011reports\/global\u2011tuberculosis\u2011report\u20112024"},{"issue":"1","key":"pone.0342273.ref005","doi-asserted-by":"crossref","first-page":"166","DOI":"10.3390\/antibiotics12010166","article-title":"First and second-line anti-tuberculosis drug-resistance patterns in pulmonary tuberculosis patients in Zambia","volume":"12","author":"N Monde","year":"2023","journal-title":"Antibiotics (Basel)"},{"issue":"3","key":"pone.0342273.ref006","doi-asserted-by":"crossref","DOI":"10.1093\/cid\/ciac445","article-title":"Tuberculosis molecular bacterial load assay reveals early delayed bacterial killing in patients with relapse","volume":"76","author":"NE Ntinginya","year":"2023","journal-title":"Clin Infect Dis"},{"issue":"1","key":"pone.0342273.ref007","doi-asserted-by":"crossref","first-page":"594","DOI":"10.1186\/s12879-020-05298-8","article-title":"Reducing delays to multidrug-resistant tuberculosis case detection through a revised routine surveillance system","volume":"20","author":"BE Doulla","year":"2020","journal-title":"BMC Infect Dis"},{"key":"pone.0342273.ref008","doi-asserted-by":"crossref","first-page":"566608","DOI":"10.3389\/fimmu.2020.566608","article-title":"Perspective for precision medicine for tuberculosis","volume":"11","author":"C Lange","year":"2020","journal-title":"Front Immunol"},{"issue":"1086","key":"pone.0342273.ref009","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1136\/postgradmedj-2015-133278","article-title":"Diagnostics for pulmonary tuberculosis","volume":"92","author":"P Cudahy","year":"2016","journal-title":"Postgrad Med J"},{"issue":"3","key":"pone.0342273.ref010","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1016\/j.ijmyco.2015.05.014","article-title":"Factors contribute to efficiency of specimen concentration of Mycobacterium tuberculosis by centrifugation and magnetic beads","volume":"4","author":"S Yoshimatsu","year":"2015","journal-title":"Int J Mycobacteriol"},{"key":"pone.0342273.ref011","unstructured":"UK Standards for Microbiology Investigations. Investigation of specimens for Mycobacterium species. B\u201140i73. London: Public Health England; 2020. Available from: https:\/\/www.rcpath.org\/static\/39286bfe-4f8a-4ce0-8d21387c6f772c6c\/UK-SMI-B-40i73-Investigation-of-specimens-for-Mycobacterium-species-October-2020.pdf"},{"issue":"6","key":"pone.0342273.ref012","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0198947","article-title":"Factors which contributed for low quality sputum smears for the detection of acid fast bacilli (AFB) at selected health centers in Ethiopia: a quality control perspective","volume":"13","author":"A Mekonen","year":"2018","journal-title":"PLoS One"},{"key":"pone.0342273.ref013","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1186\/1756-0500-6-291","article-title":"Comparison of direct versus concentrated smear microscopy in detection of pulmonary tuberculosis","volume":"6","author":"MKM Uddin","year":"2013","journal-title":"BMC Res Notes"},{"key":"pone.0342273.ref014","first-page":"257","article-title":"Effect of relative centrifugal forces and centrifugation times on recovery of Mycobacterium tuberculosis","volume":"3","author":"A Sharma","year":"2014","journal-title":"Int J Med Dent Sci"},{"issue":"7","key":"pone.0342273.ref015","doi-asserted-by":"crossref","DOI":"10.1128\/JCM.01992-18","article-title":"Molecular bacterial load assay concurs with culture on NaOH-induced loss of Mycobacterium tuberculosis Viability","volume":"57","author":"B Mtafya","year":"2019","journal-title":"J Clin Microbiol"},{"key":"pone.0342273.ref016","unstructured":"Global Laboratory Initiative (GLI). GLI Mycobacteriology Laboratory Manual. Geneva: Global Laboratory Initiative, Stop TB Partnership; 2014. Available from: https:\/\/www.stoptb.org\/wg\/gli\/assets\/documents\/gli_mycobacteriology_lab_manual_web.pdf"},{"key":"pone.0342273.ref017","doi-asserted-by":"crossref","first-page":"102633","DOI":"10.1016\/j.tube.2025.102633","article-title":"High centrifugation speed improves recovery of Mycobacterium tuberculosis and yield of culture","volume":"152","author":"GT Chaula","year":"2025","journal-title":"Tuberculosis (Edinb)"},{"issue":"1","key":"pone.0342273.ref018","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1186\/s12916-017-0955-9","article-title":"A comparison of liquid and solid culture for determining relapse and durable cure in phase III TB trials for new regimens","volume":"15","author":"PPJ Phillips","year":"2017","journal-title":"BMC Med"},{"key":"pone.0342273.ref019","article-title":"Drug resistant TB - latest developments in epidemiology, diagnostics and management","author":"S Tiberi","year":"2022","journal-title":"Int J Infect Dis"},{"key":"pone.0342273.ref020","volume-title":"Pipeline Report 2022 \u2014 Tuberculosis Diagnostics","author":"D Branigan","year":"2022"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0342273","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T17:45:30Z","timestamp":1783014330000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0342273"}},"subtitle":[],"editor":[{"given":"Guocan","family":"Yu","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,7,2]]},"references-count":20,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7,2]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0342273","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,2]]}}}