{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T13:04:18Z","timestamp":1784552658576,"version":"3.55.0"},"reference-count":18,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T00:00:00Z","timestamp":1781654400000},"content-version":"vor","delay-in-days":16,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T00:00:00Z","timestamp":1780272000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biotechnology Journal"],"published-print":{"date-parts":[[2026,6]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>\n                    Fecal microbiota transplantation (FMT) is an established treatment for recurrent\n                    <jats:italic>Clostridioides difficile<\/jats:italic>\n                    infection. As a drug product, FMT is subject to pharmaceutical quality standards, including accurate quantification of viable bacteria to ensure product consistency. We developed and validated an automated fluorescence\u2010 and image\u2010based viable\u2010cell counting method for FMT products; total\u2010cell enumeration was examined secondarily. The QUANTOM Tx system (Logos Biosystems) was validated according to ICH Q2(R2) using\n                    <jats:italic>Escherichia coli<\/jats:italic>\n                    and\n                    <jats:italic>Bacillus subtilis<\/jats:italic>\n                    as reference strains. The Viable Cell Staining Kit was validated with\u00a0\n                    <jats:italic>Escherichia coli<\/jats:italic>\n                    , whereas the Total Cell Staining Kit was examined in selected experiments using both strains. Applicability to complex FMT matrices was confirmed using authentic fecal samples. Viable\u2010cell counting showed strong linearity across a range of 9.4 \u00d7 10\n                    <jats:sup>6<\/jats:sup>\n                    \u20131.2 \u00d7 10\n                    <jats:sup>8<\/jats:sup>\n                    cells\/mL, with adequate accuracy and precision. Specificity was ensured by particle\u2010size gating, unaffected by nonviable cells or diluent. Robustness was confirmed across operators and time points. Fecal samples showed linear quantifiability and acceptable precision; total\u2010cell enumeration fulfilled linearity and precision requirements. The validated method enables rapid, reproducible viable\u2010cell quantification suitable for Quality Control of FMT drug products, supporting formulation development, and dosing verification. Viable\u2010cell quantification remains the analytical focus, despite limitations in spore detection. Total\u2010cell enumeration provides complementary process information.\n                  <\/jats:p>","DOI":"10.1002\/biot.70269","type":"journal-article","created":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T11:35:56Z","timestamp":1781696156000},"source":"Crossref","is-referenced-by-count":0,"title":["Validation of an Automated Fluorescence\u2010 and Image\u2010Based Viable Cell Counting Method for Fecal Microbiota Transplantation Drug Products"],"prefix":"10.1002","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-2120-7344","authenticated-orcid":false,"given":"Timon","family":"Lang","sequence":"first","affiliation":[{"name":"Department II of Internal Medicine Goethe University Frankfurt University Hospital Frankfurt Infectious Diseases  Frankfurt am Main Germany"},{"name":"Department of Biopharmaceutics and Pharmaceutical Technology Johannes Gutenberg\u2010University  Mainz Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fedja","family":"Farowski","sequence":"additional","affiliation":[{"name":"Department II of Internal Medicine Goethe University Frankfurt University Hospital Frankfurt Infectious Diseases  Frankfurt am Main Germany"},{"name":"Department I of Internal Medicine University of Cologne Faculty of Medicine and University Hospital Cologne  Cologne Germany"},{"name":"German Centre for Infection Research (DZIF) Partner Site Bonn\u2010Cologne  Cologne Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7994-4175","authenticated-orcid":false,"given":"Jozef","family":"Al\u2010Gousous","sequence":"additional","affiliation":[{"name":"Department of Biopharmaceutics and Pharmaceutical Technology Johannes Gutenberg\u2010University  Mainz Germany"},{"name":"Department of Pharmaceutical Sciences University of Michigan  Ann Arbor USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter","family":"Langguth","sequence":"additional","affiliation":[{"name":"Department of Biopharmaceutics and Pharmaceutical Technology Johannes Gutenberg\u2010University  Mainz Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria J. G. T.","family":"Vehreschild","sequence":"additional","affiliation":[{"name":"Department II of Internal Medicine Goethe University Frankfurt University Hospital Frankfurt Infectious Diseases  Frankfurt am Main Germany"},{"name":"Department I of Internal Medicine University of Cologne Faculty of Medicine and University Hospital Cologne  Cologne Germany"},{"name":"German Centre for Infection Research (DZIF) Partner Site Bonn\u2010Cologne  Cologne Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,6,17]]},"reference":[{"key":"e_1_2_11_2_1","doi-asserted-by":"publisher","DOI":"10.1128\/microbiolspec.bad\u20100008\u20102017"},{"key":"e_1_2_11_3_1","doi-asserted-by":"publisher","DOI":"10.1038\/nrgastro.2016.98"},{"key":"e_1_2_11_4_1","unstructured":"Bundesinstitut f\u00fcr Arzneimittel und Medizinprodukte (BfArM). (2023 June 26).F\u00e4kale Mikrobiota\u2010Transplantation (FMT Stuhltransplantation): Risiko f\u00fcr die \u00dcbertragung von multiresistenten Erregernhttps:\/\/www.bfarm.de\/SharedDocs\/Risikoinformationen\/Pharmakovigilanz\/DE\/RI\/2019\/RI\u2010FMT.html."},{"key":"e_1_2_11_5_1","unstructured":"U.S. Food and Drug Administration. (2023). Fecal Microbiota Productshttps:\/\/www.fda.gov\/vaccines\u2010blood\u2010biologics\/fecal\u2010microbiota\u2010products."},{"key":"e_1_2_11_6_1","unstructured":"Regulation on the Administration of Clinical Research and Clinical Translational Application of New Biomedical Technologies (State Council Order No. 818)(2025)."},{"key":"e_1_2_11_7_1","doi-asserted-by":"publisher","DOI":"10.1002\/mmr3.70007"},{"key":"e_1_2_11_8_1","doi-asserted-by":"publisher","DOI":"10.1002\/imt2.70083"},{"key":"e_1_2_11_9_1","doi-asserted-by":"publisher","DOI":"10.1002\/jgh3.12071"},{"key":"e_1_2_11_10_1","doi-asserted-by":"publisher","DOI":"10.3389\/fcimb.2023.1124256"},{"key":"e_1_2_11_11_1","unstructured":"L.Biosystems \u201cQ13502 QUANTOMTMViable Cell Staining Kit \u201d (2018) https:\/\/logosbio.com\/cell_counting_acc\/quantom\u2010viable\u2010cell\u2010staining\u2010kit\/."},{"key":"e_1_2_11_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/0005\u20102736(94)90190\u20102"},{"key":"e_1_2_11_13_1","doi-asserted-by":"crossref","unstructured":"R.Bainbridge\u2010Sedivy M.El\u2010Azouni M.Kang C.Lam andH.Huang \u201cA Protocol to Enumerate Total and Viable Bacterial Cells Using QUANTOM TxTMMicrobial Cell Counter \u201d (2023) https:\/\/doi.org\/10.21203\/rs.3.pex\u20102210\/v1.","DOI":"10.21203\/rs.3.pex-2210\/v1"},{"key":"e_1_2_11_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.btre.2022.e00708"},{"key":"e_1_2_11_15_1","unstructured":"International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH). (2023).ICH Harmonised Guideline: Validation of analytical procedures Q2(R2)."},{"key":"e_1_2_11_16_1","unstructured":"Logos Biosystems. (n.d.).QUANTOM TxTMMicrobial Cell Counter for Rapid Enumeration: Comparison with existing bacterial counting methods (Application Note)(accessed: 22\/08\/2025)."},{"key":"e_1_2_11_17_1","doi-asserted-by":"crossref","unstructured":"R.Bainbridge\u2010Sedivy S.Naushad I.Firth et\u00a0al. \u201cA Protocol to Enumerate Total and Viable Bacterial Cells Using QUANTOM TxTMMicrobial Cell Counter \u201d (2023) https:\/\/doi.org\/10.21203\/rs.3.pex\u20102210\/v1.","DOI":"10.21203\/rs.3.pex-2210\/v1"},{"key":"e_1_2_11_18_1","unstructured":"International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH). (2022).ICH Harmonised Guideline: Bioanalytical method validation and study sample analysis (M10)."},{"key":"e_1_2_11_19_1","unstructured":"U.S. Food and Drug Administration (FDA).Bioanalytical Method Validation Guidance for Industry(2018)."}],"container-title":["Biotechnology Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/biot.70269","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/biot.70269","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/biot.70269","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T12:25:36Z","timestamp":1784550336000},"score":1,"resource":{"primary":{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/10.1002\/biot.70269"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6]]},"references-count":18,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2026,6]]}},"alternative-id":["10.1002\/biot.70269"],"URL":"https:\/\/doi.org\/10.1002\/biot.70269","archive":["Portico"],"relation":{},"ISSN":["1860-6768","1860-7314"],"issn-type":[{"value":"1860-6768","type":"print"},{"value":"1860-7314","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6]]},"article-number":"e70269"}}