{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,13]],"date-time":"2025-11-13T12:41:32Z","timestamp":1763037692193,"version":"build-2065373602"},"reference-count":30,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2022,1,2]],"date-time":"2022-01-02T00:00:00Z","timestamp":1641081600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100010767","name":"Innovative Medicines Initiative","doi-asserted-by":"publisher","award":["115924"],"award-info":[{"award-number":["115924"]}],"id":[{"id":"10.13039\/501100010767","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Toxins"],"abstract":"<jats:p>Background: Ensuring consistency of tetanus neurotoxin (TeNT) production by Clostridium tetani could help to ensure consistent product quality in tetanus vaccine manufacturing, ultimately contributing to reduced animal testing. The aim of this study was to identify RNA signatures related to consistent TeNT production using standard and non-standard culture conditions. Methods: We applied RNA sequencing (RNA-Seq) to study C. tetani gene expression in small-scale batches under several culture conditions. Results: We identified 1381 time-dependent differentially expressed genes (DEGs) reflecting, among others, changes in growth rate and metabolism. Comparing non-standard versus standard culture conditions identified 82 condition-dependent DEGs, most of which were specific for one condition. The tetanus neurotoxin gene (tetX) was highly expressed but showed expression changes over time and between culture conditions. The tetX gene showed significant down-regulation at higher pH levels (pH 7.8), which was confirmed by the quantification data obtained with the recently validated targeted LC-MS\/MS approach. Conclusions: Non-standard culture conditions lead to different gene expression responses. The tetX gene appears to be the best transcriptional biomarker for monitoring TeNT production as part of batch-to-batch consistency testing during tetanus vaccine manufacturing.<\/jats:p>","DOI":"10.3390\/toxins14010031","type":"journal-article","created":{"date-parts":[[2022,1,9]],"date-time":"2022-01-09T23:35:09Z","timestamp":1641771309000},"page":"31","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Regulation of Clostridium tetani Neurotoxin Expression by Culture Conditions"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9188-6358","authenticated-orcid":false,"given":"Jeroen L. A.","family":"Pennings","sequence":"first","affiliation":[{"name":"Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), 3721 MA Bilthoven, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eric","family":"Abachin","sequence":"additional","affiliation":[{"name":"Sanofi Pasteur, 1541 Avenue Marcel M\u00e9rieux, 69280 Marcy l\u2019Etoile, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3973-4725","authenticated-orcid":false,"given":"Rapha\u00ebl","family":"Esson","sequence":"additional","affiliation":[{"name":"Sanofi Pasteur, 1541 Avenue Marcel M\u00e9rieux, 69280 Marcy l\u2019Etoile, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hennie","family":"Hodemaekers","sequence":"additional","affiliation":[{"name":"Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), 3721 MA Bilthoven, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Antoine","family":"Francotte","sequence":"additional","affiliation":[{"name":"Department of Chemical and Physical Health Risks, Sciensano, 14 Rue Juliette Wytsman, 1050 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jean-Baptiste","family":"Claude","sequence":"additional","affiliation":[{"name":"IVIDATA Life Sciences, 79-83 Rue Baudin, 92300 Levallois Perret, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C\u00e9line","family":"Vanhee","sequence":"additional","affiliation":[{"name":"Department of Chemical and Physical Health Risks, Sciensano, 14 Rue Juliette Wytsman, 1050 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sylvie","family":"Uhlrich","sequence":"additional","affiliation":[{"name":"Sanofi Pasteur, 1541 Avenue Marcel M\u00e9rieux, 69280 Marcy l\u2019Etoile, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9140-952X","authenticated-orcid":false,"given":"Rob J.","family":"Vandebriel","sequence":"additional","affiliation":[{"name":"Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), 3721 MA Bilthoven, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3735","DOI":"10.1002\/jps.21261","article-title":"Physical characterization of clostridium difficile toxins and toxoids: Effect of the formaldehyde crosslinking on thermal stability","volume":"97","author":"Salnikova","year":"2008","journal-title":"J. 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