{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,6,24]],"date-time":"2026-06-24T06:03:47Z","timestamp":1782281027612,"version":"3.54.5"},"posted":{"date-parts":[[2025,5,13]]},"group-title":"Microbiology","reference-count":40,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2025,5,13]],"date-time":"2025-05-13T00:00:00Z","timestamp":1747094400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.biorxiv.org\/about\/FAQ#license"}],"funder":[{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases","doi-asserted-by":"crossref","award":["R01AI152078"],"award-info":[{"award-number":["R01AI152078"]}],"id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases","doi-asserted-by":"crossref","award":["R01AI162381"],"award-info":[{"award-number":["R01AI162381"]}],"id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2025,5,13]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>The measurement of cryptococcal capsular polysaccharide (PS) amount and concentration is essential for laboratory studies of its structure and function. Clinically, the detection of cryptococcal capsular polysaccharide as cryptococcal antigen is a foundational assay for the diagnosis of cryptococcosis. In this study we compared the results of four laboratory assays for measuring cryptococcal polysaccharide (gravimetric determination, phenol-sulfuric acid reactivity, Size Exclusion Chromatography Multi-Angle Light Scattering (SEC-MALS), and ELISA) and two clinical assays (lateral flow assay (LFA) (IMMY) and the cryptococcal latex agglutination assay (CLAA) (Remel)) using four cryptococcal strains that each express single repeating polysaccharide motifs. The results show that the sensitivity of laboratory assays for PS was relatively consistent but manifested significant variation with strain. Phenol-sulfuric acid determination was highly variable unless the PS was pre-digested with HCl, suggesting that differences in the structural complexity of the polysaccharide could affect timing and intensity of the colorimetric reaction. Serological assays were the most sensitive, but these showed the most strain-to-strain variation on the threshold of PS detection consistent with antigenic differences. Differences in the reactivity of LFA and CLAA for cryptococcal PS from different strains imply that comparable cryptococcal antigen titers could reflect different concentrations of PS in bodily fluids. In summary, we find that variation in PS structure amongst strains can affect the sensitivity of the various tests used to measure cryptococcal PS. (Word count: 224)<\/jats:p>","DOI":"10.1101\/2025.05.13.653753","type":"posted-content","created":{"date-parts":[[2025,5,14]],"date-time":"2025-05-14T01:50:14Z","timestamp":1747187414000},"source":"Crossref","is-referenced-by-count":0,"title":["Unexpected variability in laboratory and clinical assays used to quantify\n                  <i>Cryptococcus neoformans<\/i>\n                  polysaccharide"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8581-7831","authenticated-orcid":false,"given":"Maggie P.","family":"Wear","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Davin","family":"Kim","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Risha","family":"Roy","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9402-9167","authenticated-orcid":false,"given":"Arturo","family":"Casadevall","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2025051700250796000_2025.05.13.653753v1.1","doi-asserted-by":"publisher","DOI":"10.1016\/j.diagmicrobio.2011.08.003"},{"key":"2025051700250796000_2025.05.13.653753v1.2","doi-asserted-by":"publisher","DOI":"10.1128\/EC.00370-07"},{"key":"2025051700250796000_2025.05.13.653753v1.3","doi-asserted-by":"publisher","DOI":"10.1128\/JB.94.5.1480-1483.1967"},{"key":"2025051700250796000_2025.05.13.653753v1.4","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M116.767582"},{"key":"2025051700250796000_2025.05.13.653753v1.5","doi-asserted-by":"publisher","DOI":"10.1016\/j.fgb.2009.09.001"},{"key":"2025051700250796000_2025.05.13.653753v1.6","doi-asserted-by":"publisher","DOI":"10.1093\/glycob\/cwy030"},{"key":"2025051700250796000_2025.05.13.653753v1.7","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2011.00207"},{"key":"2025051700250796000_2025.05.13.653753v1.8","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M509465200"},{"key":"2025051700250796000_2025.05.13.653753v1.9","doi-asserted-by":"publisher","DOI":"10.1063\/1.1746738"},{"key":"2025051700250796000_2025.05.13.653753v1.10","doi-asserted-by":"publisher","DOI":"10.1021\/ac60111a017"},{"key":"2025051700250796000_2025.05.13.653753v1.11","first-page":"565","article-title":"Methods to identify the unexplored diversity of microbial exopolysaccharides","volume":"6","year":"2015","journal-title":"Front Microbiol"},{"key":"2025051700250796000_2025.05.13.653753v1.12","doi-asserted-by":"publisher","DOI":"10.1128\/iai.55.3.742-748.1987"},{"key":"2025051700250796000_2025.05.13.653753v1.13","doi-asserted-by":"publisher","DOI":"10.1007\/978-1-0716-3722-7_16"},{"key":"2025051700250796000_2025.05.13.653753v1.14","doi-asserted-by":"publisher","DOI":"10.1128\/cdli.5.2.146-159.1998"},{"key":"2025051700250796000_2025.05.13.653753v1.15","doi-asserted-by":"publisher","DOI":"10.1128\/EC.00122-07"},{"key":"2025051700250796000_2025.05.13.653753v1.16","doi-asserted-by":"publisher","DOI":"10.1016\/j.jbc.2022.101769"},{"key":"2025051700250796000_2025.05.13.653753v1.17","doi-asserted-by":"publisher","DOI":"10.1016\/j.carbpol.2022.119547"},{"key":"2025051700250796000_2025.05.13.653753v1.18","doi-asserted-by":"publisher","DOI":"10.1016\/j.lwt.2022.113860"},{"key":"2025051700250796000_2025.05.13.653753v1.19","doi-asserted-by":"publisher","DOI":"10.1039\/d0sc01249a"},{"key":"2025051700250796000_2025.05.13.653753v1.20","doi-asserted-by":"publisher","DOI":"10.1021\/acsinfecdis.3c00447"},{"key":"2025051700250796000_2025.05.13.653753v1.21","first-page":"903","article-title":"Monoclonal antibodies reactive with immunorecessive epitopes of glucuronoxylomannan, the major capsular polysaccharide of Cryptococcus neoformans","volume":"10","year":"2003","journal-title":"Clin Diagn Lab Immunol"},{"key":"2025051700250796000_2025.05.13.653753v1.22","doi-asserted-by":"publisher","DOI":"10.1128\/iai.65.2.718-728.1997"},{"key":"2025051700250796000_2025.05.13.653753v1.23","doi-asserted-by":"publisher","DOI":"10.3389\/fcimb.2022.861405"},{"key":"2025051700250796000_2025.05.13.653753v1.24","doi-asserted-by":"publisher","DOI":"10.3389\/fcimb.2021.683670"},{"key":"2025051700250796000_2025.05.13.653753v1.25","doi-asserted-by":"publisher","DOI":"10.5344\/ajev.2014.14076"},{"key":"2025051700250796000_2025.05.13.653753v1.26","doi-asserted-by":"publisher","DOI":"10.1016\/j.chroma.2015.04.054"},{"key":"2025051700250796000_2025.05.13.653753v1.27","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2958.2010.07511.x"},{"key":"2025051700250796000_2025.05.13.653753v1.28","doi-asserted-by":"crossref","unstructured":"Wear MP , Jacobs E , Wang S , McConnell S , Bowen A , Strother C , Cordero RJ , Casadevall A. 2021. Cryptococcus neoformans capsule regrowth experiments reveal dynamics of enlargement and architecture. BioRxiv.","DOI":"10.1101\/2021.11.15.468433"},{"key":"2025051700250796000_2025.05.13.653753v1.29","unstructured":"Wear MP , Hargett AA , Kelly JE , McConnell SA , Crawford CJ , Freedberg DI , Stark RE , Casadevall A. Lyophilization induces alterations in cryptococcal exopolysaccharide resulting in reduced antibody binding. BioRxiv."},{"key":"2025051700250796000_2025.05.13.653753v1.30","doi-asserted-by":"publisher","DOI":"10.1128\/EC.00378-07"},{"key":"2025051700250796000_2025.05.13.653753v1.31","doi-asserted-by":"publisher","DOI":"10.1084\/jem.177.4.1105"},{"key":"2025051700250796000_2025.05.13.653753v1.32","doi-asserted-by":"publisher","DOI":"10.1128\/jcm.33.3.765-768.1995"},{"key":"2025051700250796000_2025.05.13.653753v1.33","doi-asserted-by":"crossref","unstructured":"Wear MP , Casadevall A. 2021. Polysaccharides of Fungal Origin: Focus on the Capsule of the Pathogen Cryptococcus neoformans, p. 1\u201321. In Oliveira, J , Radhouani, H , Reis, RL (eds.), Polysaccharides of microbial origin: biomedical applications. Springer International Publishing, Cham.","DOI":"10.1007\/978-3-030-35734-4_29-1"},{"key":"2025051700250796000_2025.05.13.653753v1.34","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2958.2001.02651.x"},{"key":"2025051700250796000_2025.05.13.653753v1.35","doi-asserted-by":"publisher","DOI":"10.4049\/jimmunol.172.6.3670"},{"key":"2025051700250796000_2025.05.13.653753v1.36","doi-asserted-by":"crossref","unstructured":"de Holanda Fonseca DL , Silva DMW da , de Albuquerque Maranh\u00e3o FC. 2024. Molecular characterization of clinical and environmental isolates from the Cryptococcus neoformans\/C. Gattii species complexes of Macei\u00f3, Alagoas, Brazil. Braz J Microbiol.","DOI":"10.1007\/s42770-024-01313-1"},{"key":"2025051700250796000_2025.05.13.653753v1.37","doi-asserted-by":"crossref","unstructured":"Wang P , Li Y , Gao L , Tang X , Zheng D , Wu K , Wang L , Guo P , Ye F. 2024. In vitro characterization and molecular epidemiology of Cryptococcus spp. isolates from non-HIV patients in Guangdong, China. Front Microbiol 14.","DOI":"10.3389\/fmicb.2023.1295363"},{"key":"2025051700250796000_2025.05.13.653753v1.38","doi-asserted-by":"crossref","unstructured":"Xess I , Pandey M , Dabas Y , Agarwal R , Das S , Srivastava PMV , Thakur R , Sharma S , Mani P , Biswas A , Bhowmik D , Das BK , Singh R , Panda P , Singh G , Phukan AC , Yhome M , Valsan C , Kindo AJ . 2021. Multilocus Sequence Typing of Clinical Isolates of Cryptococcus from India. Mycopathologia.","DOI":"10.1007\/s11046-020-00500-6"},{"key":"2025051700250796000_2025.05.13.653753v1.39","doi-asserted-by":"crossref","unstructured":"Puime CA , B\u00f3rmida V , Pan D. 2023. Molecular typing and antifungal susceptibility of clinical isolates of Cryptococcus neoformans and Cryptococcus gattii species complexes from the National Invasive Fungal Surveillance Network of Uruguay. Med Mycol.","DOI":"10.1093\/mmy\/myad059"},{"key":"2025051700250796000_2025.05.13.653753v1.40","doi-asserted-by":"crossref","unstructured":"Chen Y-C , Kuo S-F , Lin S-Y , Lin Y-S , Lee C-H. 2022. Epidemiological and Clinical Characteristics, Antifungal Susceptibility, and MLST-Based Genetic Analysis of Cryptococcus Isolates in Southern Taiwan in 2013-2020. J Fungi (Basel) 8.","DOI":"10.3390\/jof8030287"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1101\/2025.05.13.653753","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,24]],"date-time":"2026-06-24T05:13:40Z","timestamp":1782278020000},"score":1,"resource":{"primary":{"URL":"http:\/\/biorxiv.org\/lookup\/doi\/10.1101\/2025.05.13.653753"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,5,13]]},"references-count":40,"URL":"https:\/\/doi.org\/10.1101\/2025.05.13.653753","relation":{"is-preprint-of":[{"id-type":"doi","id":"10.1093\/infdis\/jiaf540","asserted-by":"subject"}]},"subject":[],"published":{"date-parts":[[2025,5,13]]},"subtype":"preprint"}}